Revistas
Revista:
HUMAN GENE THERAPY
ISSN 1043-0342
Vol. 32
N° 7-8
Año 2021
Págs.341 - 348
Tight control of transgene expression is key to ensure the efficacy of a wide range of gene therapy interventions, in which the magnitude and duration of gene expression have to be adjusted to therapeutic needs, thereby limiting secondary effects. The development of upgraded strategies to link transgene expression to pathological stress episodes is an unmet need in gene therapy. Here, we propose an expression strategy that associates transgene expression to an intracellular stress coping mechanism, the unfolded protein response. Specifically, we harnessed the cis elements required to sustain the noncanonical splicing of X-box binding protein 1 (XBP1) messenger RNA (mRNA) in response to the dysfunction of the endoplasmic reticulum (ER), a situation commonly known as ER stress, to drive the expression of heterologous genes. Since ER stress features a wide variety of pathological conditions, including viral infections, cancer, or metabolic disorders, this new expression module stimulates the synthesis of therapeutic genes as a response to cellular damage, and ensures their expression only when necessary. Validation of this inducible expression system was performed in vitro and in vivo, and its potential to limit/inhibit viral infections has been shown in proof-of principle experiments.
Revista:
CURRENT OPINION IN GASTROENTEROLOGY
ISSN 0267-1379
Vol. 37
N° 2
Año 2021
Págs.91 - 98
Purpose of review Primary biliary cholangitis (PBC) is characterized by autoimmune damage of intrahepatic bile ducts associated with a loss of tolerance to mitochondrial antigens. PBC etiopathogenesis is intriguing because of different perplexing features, namely: a) although mitochondria are present in all cell types and tissues, the damage is mainly restricted to biliary epithelial cells (BECs); b) despite being an autoimmune disorder, it does not respond to immunosuppressive drugs but rather to ursodeoxycholic acid, a bile salt that induces HCO3- rich choleresis; c) the overwhelming female preponderance of the disease remains unexplained. Here we present an etiopathogenic view of PBC which sheds light on these puzzling facts of the disease. Recent findings PBC develops in patients with genetic predisposition to autoimmunity in whom epigenetic mechanisms silence the Cl-/HCO3- exchanger AE2 in both cholangiocytes and lymphoid cells. Defective AE2 function can produce BECs damage as a result of decreased biliary HCO3- secretion with disruption of the protective alkaline umbrella that normally prevents the penetration of toxic apolar bile salts into cholangiocytes. AE2 dysfunction also causes increased intracellular pH (pHi) in cholangiocytes, leading to the activation of soluble adenylyl cyclase, which sensitizes BECs to bile salt-induced apoptosis. Recently, mitophagy was found to be inhibited by cytosolic alkalization and stimulated by acidification. Accordingly, we propose that AE2 deficiency may disturb mitophagy in BECs, thus, promoting the accumulation of defective mitochondria, oxidative stress and presentation of mitochondrial antigens to the immune cells. As women possess a more acidic endolysosomal milieu than men, mitophagy might be more affected in women in an AE2-defective background. Apart from affecting BECs function, AE2 downregulation in lymphocytes may also contribute to alter immunoregulation facilitating autoreactive T-cell responses. Summary PBC can be considered as a disorder of Cl-/HCO3- exchange in individuals with genetic predisposition to autoimmunity.
Revista:
HUMAN MOLECULAR GENETICS
ISSN 0964-6906
Vol. 29
N° 19
Año 2020
Págs.3211 - 3223
Autores:
Xiang, J. Y.; Zhang, N.; Sun, H. ; et al.
Revista:
GASTROENTEROLOGY
ISSN 0016-5085
Vol. 158
N° 3
Año 2020
Págs.664 - 678.e24
BACKGROUND & AIMS: Immune checkpoint inhibitors have some efficacy in the treatment of hepatocellular carcinoma (HCC). Programmed cell death 1 ligand 1 (PD-L1), expressed on some cancer cells, binds to the receptor programmed cell death 1 (PDCD1, also called PD1) on T cells to prevent their proliferation and reduce the antigen-tumor immune response. Immune cells that infiltrate some types of HCCs secrete interferon gamma (IFNG). Some HCC cells express myocyte enhancer factor 2D (MEF2D), which has been associated with shorter survival times of patients. We studied whether HCC cell expression of MEF2D regulates expression of PD-L1 in response to IFNG. METHODS: We analyzed immune cells from 20 fresh HCC tissues by flow cytometry. We analyzed 225 fixed HCC tissues (from 2 cohorts) from patients in China by immunohistochemistry and obtained survival data. We created mice with liver-specific knockout of MEF2D (MEF2D(LPC-KO) mice). We knocked out or knocked down MEF2D, E1A binding protein p300 (p300), or sirtuin 7 (SIRT7) in SMMC-7721, Huh7, H22, and Hepa1-6 HCC cell lines, some incubated with IFNG. We analyzed liver tissues from mice and cell lines by RNA sequencing, immunoblot, dual luciferase reporter, and chromatin precipitation assays. MEF2D protein acetylation and proteins that interact with MEF2D were identified by coimmunoprecipitation and pull-down assays. H22 cells, with MEF2D knockout or without (controls), were transplanted into BALB/c mice, and some mice were given antibodies to deplete T cells. Mice bearing orthotopic tumors grown from HCC cells, with or without knockout of SIRT7, were given injections of an antibody against PD1. Growth of tumors was measured, and tumors were analyzed by immunohistochemistry and flow cytometry. RESULTS: In human HCC specimens, we found an inverse correlation between level of MEF2D and numbers of CD4(+) and CD8(+) T cells; level of MEF2D correlated with percentages of PD1-positive or TIM3-positive CD8(+) T cells. Knockout of MEF2D from H22 cells reduced their growth as allograft tumors in immune-competent mice but not in immune-deficient mice or mice with depletion of CD8(+) T cells. When MEF2D-knockout cells were injected into immune- competent mice, they formed smaller tumors that had increased infiltration and activation of T cells compared with control HCC cells. In human and mouse HCC cells, MEF2D knockdown or knockout reduced expression of PD-L1. MEF2D bound the promoter region of the CD274 gene (encodes PD-L1) and activated its transcription. Overexpression of p300 in HCC cells, or knockout of SIRT7, promoted acetylation of MEF2D and increased its binding, along with acetylated histones, to the promoter region of CD274. Exposure of HCC cells to IFNG induced expression of p300 and its binding MEF2D, which reduced the interaction between MEF2D and SIRT7. MEF2D-induced expression of PD-L1 upon IFNG exposure was independent of interferon-regulatory factors 1 or 9. In HCC cells not exposed to IFNG, SIRT7 formed a complex with MEF2D that attenuated expression of PD-L1. Knockout of SIRT7 reduced proliferation of HCC cells and growth of tumors in immune-deficient mice. Compared with allograft tumors grown from control HCC cells, in immune-competent mice, tumors grown from SIRT7-knockout HCC cells expressed higher levels of PD-L1 and had reduced infiltration and activation of T cells. In immune-competent mice given antibodies to PD1, allograft tumors grew more slowly from SIRT7-knockout HCC cells than from control HCC cells. CONCLUSIONS: Expression of MEF2D by HCC cells increases their expression of PD-L1, which prevents CD8(+) T-cell-mediated antitumor immunity. When HCC cells are exposed to IFNG, p300 acetylates MEF2D, causing it to bind the CD274 gene promoter and up-regulate PD-L1 expression. In addition to promoting HCC cell proliferation, SIRT7 reduced acetylation of MEF2D and expression of PD-L1 in HCC cells not exposed to IFNG. Strategies to manipulate this pathway might increase the efficacy of immune therapies for HCC.
Autores:
Gholizadeh, M.; Szelag-Pieniek, S.; Post, M.; et al.
Revista:
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
ISSN 1422-0067
Vol. 21
N° 19
Año 2020
Págs.7368
Liver diseases are important causes of morbidity and mortality worldwide. The aim of this study was to identify differentially expressed microRNAs (miRNAs), target genes, and key pathways as innovative diagnostic biomarkers in liver patients with different pathology and functional state. We determined, using RT-qPCR, the expression of 472 miRNAs in 125 explanted livers from subjects with six different liver pathologies and from control livers. ANOVA was employed to obtain differentially expressed miRNAs (DEMs), and miRDB (MicroRNA target prediction database) was used to predict target genes. A miRNA-gene differential regulatory (MGDR) network was constructed for each condition. Key miRNAs were detected using topological analysis. Enrichment analysis for DEMs was performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). We identified important DEMs common and specific to the different patient groups and disease progression stages. hsa-miR-1275 was universally downregulated regardless the disease etiology and stage, while hsa-let-7a*, hsa-miR-195, hsa-miR-374, and hsa-miR-378 were deregulated. The most significantly enriched pathways of target genes controlled by these miRNAs comprise p53 tumor suppressor protein (TP53)-regulated metabolic genes, and those involved in regulation of methyl-CpG-binding protein 2 (MECP2) expression, phosphatase and tensin homolog (PTEN) messenger RNA (mRNA) translation and copper homeostasis. Our findings show a novel panel of deregulated miRNAs in the liver tissue from patients with different liver pathologies. These miRNAs hold potential as biomarkers for diagnosis and staging of liver diseases.
Autores:
Drozdzik, M. (Autor de correspondencia); Szelag-Pieniek, S. ; Post, M. ; et al.
Revista:
CLINICAL PHARMACOLOGY AND THERAPEUTICS
ISSN 0009-9236
Vol. 107
N° 5
Año 2020
Págs.1138 - 1148
Hepatocellular transporter levels were quantified using quantitative reverse transcription polymerase chain reaction and liquid chromatography-tandem mass spectrometry methods. Liver function deterioration (Child-Pugh class C) produced significant protein abundance (mean values) increase (to healthy livers) in P-gp (to 260% (CV (coefficient of variation) 82%)) and MRP4 (CV 230%) (not detected in healthy livers), decrease in MRP2 (to 30% (CV 126%)), NTCP (to 34% (CV 112%)), OCT1 (to 35% (CV 153%)), OATP1B1 (to 46% (CV 73%)), and OATP2B1 (to 27% (CV 230%)), whereas BSEP (CV 99%), MRP3 (CV 106%), OAT2 (CV 97%), OCT3 (CV 113%), and OATP1B3 (CV 144%) remained unchanged. Alcoholic liver disease produced significant protein downregulation of MRP2 (to 30% (CV 134%)), NTCP (to 76% (CV 78%)), OAT2 (to 26% (CV 117%)), OATP1B1 (to 61% (CV 76%)), OATP1B3 (to 79% (CV 160%)), and OATP2B1 (to 73% (CV 90%)) of healthy tissue values. Hepatitis C produced BSEP (to 47% (CV 99%)) and OATP2B1 (to 74% (CV 91%)) protein reduction. Primary biliary cholangitis and primary sclerosing cholangitis demonstrated P-gp and MRP4 protein upregulation (to 350% (CV 47%) and 287% (CV 38%), respectively). Autoimmune hepatitis revealed P-gp (to 410% (CV 49%)) and MRP4 (CV 96%) increase, and MRP2 (to 18% (CV 259%)) protein decrease. Drug transporters' protein abundance depends on liver pathology type and its functional state.
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 70
N° 3
Año 2019
Págs.1061 - 1063
Revista:
FASEB JOURNAL
ISSN 0892-6638
Vol. 33
N° 6
Año 2019
Págs.7578 - 7587
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 70
Año 2019
Págs.1101A - 1102A
Autores:
Alonso-Pena, M. ; Hermanns, H.; Herraez, E. ; et al.
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 70
N° 1
Año 2019
Págs.E579 - E579
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 70
N° 1
Año 2019
Págs.108 - 126
Gene therapy with an adeno-associated vector (AAV) serotype 8 encoding the human ATPase copper-transporting beta polypeptide (ATP7B) complementary DNA (cDNA; AAV8¿ATP7B) is able to provide long-term copper metabolism correction in 6-week-old male Wilson disease (WD) mice. However, the size of the genome (5.2 kilobases [kb]) surpasses the optimal packaging capacity of the vector, which resulted in low-yield production; in addition, further analyses in WD female mice and in animals with a more advanced disease revealed reduced therapeutic efficacy, as compared to younger males. To improve efficacy of the treatment, an optimized shorter AAV vector was generated, in which four out of six metal¿binding domains (MBDs) were deleted from the ATP7B coding sequence, giving rise to the miniATP7B protein (delta57-486-ATP7B). In contrast to AAV8-ATP7B, AAV8-miniATP7B could be produced at high titers and was able to restore copper homeostasis in 6- and 12-week-old male and female WD mice. In addition, a recently developed synthetic AAV vector, AAVAnc80, carrying the miniATP7B gene was similarly effective at preventing liver damage, restoring copper homeostasis, and improving survival 1 year after treatment. Transduction of approximately 20% of hepatocytes was sufficient to normalize copper homeostasis, suggesting that corrected hepatocytes are acting as a sink to eliminate excess of copper.
Revista:
MOLECULAR THERAPY
ISSN 1525-0016
Vol. 27
N° 11
Año 2019
Págs.1892 - 1905
Immune checkpoint blockade has shown anti-cancer efficacy, but requires systemic administration of monoclonal antibodies (mAbs), often leading to adverse effects. To avoid toxicity, mAbs could be expressed locally in tumors. We developed adeno-associated virus (AAV) and Semliki Forest virus (SFV) vectors expressing anti-programmed death ligand 1 (aPDL1) mAb. When injected intratumorally in MC38 tumors, both viral vectors led to similar local mAb expression at 24 h, diminishing quickly in SFV-aPDL1-treated tumors. However, SFV-aPDL1 induced >40% complete regressions and was superior to AAV-aPDL1, as well as to aPDL1 mAb given systemically or locally. SFV-aPDL1 induced abscopal effects and was also efficacious against B16-ovalbumin (OVA). The higher SFV-aPDL1 antitumor activity could be related to local upregulation of interferon-stimulated genes because of SFV RNA replication. This was confirmed by combining local SFV-LacZ administration and systemic aPDL1 mAb, which provided higher antitumor effects than each separated agent. SFVaPDL1 promoted tumor-specific CD8 T cells infiltration in both tumor models. In MC38, SFV-aPDL1 upregulated co-stimulatory markers (CD137/OX40) in tumor CD8 T cells, and its combination with anti-CD137 mAb showed more pronounced antitumor effects than each single agent. These results indicate that local transient expression of immunomodulatory mAbs using non-propagative RNA vectors inducing type I interferon (IFN-I) responses represents a potent and s
Revista:
CELL DEATH AND DISEASE
ISSN 2041-4889
Vol. 10
N° 1
Año 2019
Págs.14
Liver cirrhosis results from chronic hepatic damage and is characterized by derangement of the organ architecture with increased liver fibrogenesis and defective hepatocellular function. It frequently evolves into progressive hepatic insufficiency associated with high mortality unless liver transplantation is performed. We have hypothesized that the deficiency of critical nutrients such as essential omega-3 fatty acids might play a role in the progression of liver cirrhosis. Here we evaluated by LC-MS/MS the liver content of omega-3 docosahexaenoic fatty acid (DHA) in cirrhotic patients and investigated the effect of DHA in a murine model of liver injury and in the response of hepatic stellate cells (HSCs) (the main producers of collagen in the liver) to pro-fibrogenic stimuli. We found that cirrhotic livers exhibit a marked depletion of DHA and that this alteration correlates with the progression of the disease. Administration of DHA exerts potent anti-fibrogenic effects in an acute model of liver damage. Studies with HSCs show that DHA inhibits fibrogenesis more intensely than other omega-3 fatty acids. Data from expression arrays revealed that DHA blocks TGF beta and NF-kappa B pathways. Mechanistically, DHA decreases late, but not early, SMAD3 nuclear accumulation and inhibits p65/RelA-S536 phosphorylation, which is required for HSC survival. Notably, DHA increases ADRP expression, leading to the formation of typical quiescence-associated perinuclear lipid droplets. In conclusion, a marked depletion of DHA is present in the liver of patients with advanced cirrhosis. DHA displays anti-fibrogenic activities on HSCs targeting NF-kappa B and TGF beta pathways and inducing ADPR expression and quiescence in these cells.
Autores:
Suarez-Amaran, L.; Usai, C.; Di Scala, M.; et al.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 1600-0641
Vol. 69
N° 1
Año 2018
Págs.262 - 264
Revista:
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE
ISSN 0925-4439
Vol. 1864
N° 4
Año 2018
Págs.1326 - 1334
The liver has an extraordinary regenerative capacity rapidly triggered upon injury or resection. This response is intrinsically adjusted in its initiation and termination, a property termed the "hepatostat". Several molecules have been involved in liver regeneration, and among them bile acids may play a central role. Intrahepatic levels of bile acids rapidly increase after resection. Through the activation of farnesoid X receptor (FXR), bile acids regulate their hepatic metabolism and also promote hepatocellular proliferation. FXR is also expressed in em terocytes, where bile acids stimulate the expression of fibroblast growth factor 15/19 (FGF15/19), which is released to the portal blood. Through the activation of FGFR4 on hepatocytes FGF15/19 regulates bile acids synthesis and finely tunes liver regeneration as part of the "hepatostat". Here we review the experimental evidences supporting the relevance of the FXR-FGF15/19-FGFR4 axis in liver regeneration and discuss potential therapeutic applications of PGF15/19 in the prevention of liver failure. This article is part of a Special Issue entitled: Cholangiocytes in Health and Disease edited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 68
N° Supl. 1
Año 2018
Págs.S83 - S83
Autores:
Erice, O.; Munoz-Garrido, P.; Vaquero, J.; et al.
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 67
N° 4
Año 2018
Págs.1420 - 1440
Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease associated with autoimmune phenomena targeting intrahepatic bile duct cells (cholangiocytes). Although its etiopathogenesis remains obscure, development of antimitochondrial autoantibodies against pyruvate dehydrogenase complex E2 is a common feature. MicroRNA (miR) dysregulation occurs in liver and immune cells of PBC patients, but its functional relevance is largely unknown. We previously reported that miR-506 is overexpressed in PBC cholangiocytes and directly targets both Cl-/ HCO3-anion exchanger 2 and type III inositol 1,4,5-trisphosphate receptor, leading to cholestasis. Here, the regulation of miR-506 gene expression and its role in cholangiocyte pathophysiology and immune activation was studied. Several proinflammatory cytokines overexpressed in PBC livers (such as interleukin-8 [IL8], IL12, IL17, IL18, and tumor necrosis factor alpha) stimulated miR-506 promoter activity in human cholangiocytes, as revealed by luciferase reporter assays. Experimental overexpression of miR-506 in cholangiocytes dysregulated the cell proteomic profile (by mass spectrometry), affecting proteins involved in different biological processes including mitochondrial metabolism. In cholangiocytes, miR-506 (1) induced dedifferentiation with down-regulation of biliary and epithelial markers together with up-regulation of mesenchymal, proinflammatory, and profibrotic markers; (2) impaired cell proliferation and adhesion; (3) increased oxidative and endoplasmic reticulum stress; (4) caused DNA damage; and (5) sensitized to caspase-3-dependent apoptosis induced by cytotoxic bile acids. These events were also associated with impaired energy metabolism in mitochondria (proton leak and less adenosine triphosphate production) and pyruvate dehydrogenase complex E2 overexpression. Coculture of miR-506 overexpressing cholangiocytes with PBC immunocytes induced activation and proliferation of PBC immunocytes. Conclusion: Different proinflammatory cytokines enhance the expression of miR-506 in biliary epithelial cells; miR-506 induces PBC-like features in cholangiocytes and promotes immune activation, representing a potential therapeutic target for PBC patients. (Hepatology 2018;67:1420-1440)
Revista:
MOLECULAR THERAPY
ISSN 1525-0016
Vol. 26
N° 5
Año 2018
Págs.388 - 388
Revista:
IMMUNOHORIZONS
ISSN 2573-7732
Vol. 2
N° 11
Año 2018
Págs.363 - 376
The innate immune system provides a primary line of defense against pathogens. Stimulator of IFN genes (STING), encoded by the TMEM173 gene, is a critical protein involved in IFN-ß induction in response to infection by different pathogens. In this study, we describe the expression of three different alternative-spliced human (h) TMEM173 mRNAs producing STING truncated isoforms 1, 2, and 3 in addition to the full-length wild-type (wt) hSTING. All of the truncated isoforms lack exon 7 and share the N-terminal transmembrane region with wt hSTING. Overexpression of the three STING truncated isoforms failed to induce IFN-ß, and they acted as selective pathway inhibitors of wt hSTING even in combination with upstream inducer cyclic-di-GMP-AMP synthase. Truncated isoforms alter the stability of wt hSTING, reducing protein t1/2 to some extent by the induction of proteasome-dependent degradation. Knocking down expression of truncated isoforms increased production of IFN-ß by THP1 monocytes in response to intracellular cytosolic DNA or HSV-1 infection. At early stages of infection, viruses like HSV-1 or vesicular stomatitis virus reduced the ratio of full-length wt hSTING/truncated STING isoforms, suggesting the skewing of alternative splicing of STING toward truncated forms as a tactic to evade antiviral responses. Finally, in silico analysis revealed that the human intron¿exon gene architecture of TMEM173 (splice sites included) is preserved in other mammal species, predominantly primates, stressing the relevance of alternative splicing in regulating STING antiviral biology.
Revista:
MOLECULAR THERAPY
ISSN 1525-0016
Vol. 26
N° 5
Año 2018
Págs.249 - 250
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 67
N° 4
Año 2017
Págs.669 - 679
BACKGROUND & AIMS:
Studying hepatitis delta virus (HDV) and developing new treatments is hampered by the limited availability of small animal models. Herein, a description of a robust mouse model of HDV infection that mimics several important characteristics of the human disease is presented.
METHODS:
HDV and hepatitis B virus (HBV) replication competent genomes were delivered to the mouse liver using adeno-associated viruses (AAV; AAV-HDV and AAV-HBV). Viral load, antigen expression and genomes were quantified at different time points after AAV injection. Furthermore, liver pathology, genome editing, and the activation of the innate immune response were evaluated.
RESULTS:
AAV-HDV infection initiated HDV replication in mouse hepatocytes. Genome editing was confirmed by the presence of small and large HDV antigens and sequencing. Viral replication was detected for 45days, even after the AAV-HDV vector had almost disappeared. In the presence of HBV, HDV infectious particles were detected in serum. Furthermore, as observed in patients, co-infection was associated with the reduction of HBV antigen expression and the onset of liver damage that included the alteration of genes involved in the development of liver pathologies. HDV replication induced a sustained type I interferon response, which was significantly reduced in immunodeficient mice and almost absent in mitochondrial antiviral signaling protein (MAVS)-deficient mice.
CONCLUSION:
The animal model described here reproduces important characteristics of human HDV infection and provides a valuable tool for characterizing the viral infection and for developing new treatments. Furthermore, MAVS was identified as a main player in HDV detection and adaptive immunity was found to be involved in the amplification of the innate immune response. Lay summary: Co-infection with hepatitis B and D virus (HBV and HDV, respectively) often causes a more severe disease condition than HBV alone. Gaining more insight into HDV and developing new treatments is hampered by limited availability of adequate immune competent small animal models and new ones are needed. Here, a mouse model of HDV infection is described, which mimics several important characteristics of the human disease, such as the initiation and maintenance of replication in murine hepatocytes, genome editing and, in the presence of HBV, generation of infectious particles. Lastly, the involvement of an adaptive immunity and the intracellular signaling molecule MAVS in mounting a strong and lasting innate response was shown. Thus, our model serves as a useful tool for the investigation of HDV biology and new treatments.
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 66
N° 1
Año 2017
Págs.S483 - S483
Autores:
Monte, M. J.; Alonso-Pena, M.; Briz, O.; et al.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 66
N° 3
Año 2017
Págs.581 - 588
Background & Aims: Acyl-CoA oxidase (ACOX2) is involved in the shortening of C27 cholesterol derivatives to generate C24 bile acids. Inborn errors affecting the rest of peroxisomal enzymes involved in bile acid biosynthesis have been described. Here we aimed at investigating the case of an adolescent boy with persistent hypertransaminasemia of unknown origin and suspected dysfunction in bile acid metabolism. Methods: Serum and urine samples were taken from the patient, his sister and parents and underwent HPLC-MS/MS and HPLC-TOF analyses. Coding exons in genes of interest were amplified by high-fidelity PCR and sequenced. Wild-type or mutated (mutACOX2) variants were overexpressed in human hepatoblastoma HepG2 cells to determine ACOX2 enzymatic activity, expression and subcellular location. Results: The patient's serum and urine showed negligible amounts of C24 bile acids, but augmented levels of C27 intermediates, mainly tauroconjugated trihydroxycholestanoic acid (THCA). Genetic analysis of enzymes potentially involved revealed a homozygous missense mutation (c.673C>T; R225W) in ACOX2. His only sister was also homozygous for this mutation and exhibited similar alterations in bile acid profiles. Both parents were heterozygous and presented normal C24 and C27 bile acid levels. Immunofluorescence studies showed similar protein size and peroxisomal localization for both normal and mutated variants. THCA biotransformation into cholic acid was enhanced in cells overexpressing ACOX2, but not in those overexpressing mutACOX2. Both cell types showed similar sensitivity to oxidative stress caused by C24 bile acids. In contrast, THCA-induced oxidative stress and cell death were reduced by overexpressing ACOX2, but not mutACOX2. Conclusion: ACOX2 deficiency, a condition characterized by accumulation of toxic C27 bile acid intermediates, is a novel cause of isolated persistent hypertransaminasemia. Lay summary: Elevation of serum transaminases is a biochemical sign of liver damage due to multiplicity of causes (viruses, toxins, autoimmunity, metabolic disorders). In rare cases the origin of this alteration remains unknown. We have identified by the first time in a young patient and his only sister a familiar genetic defect of an enzyme called ACOX2, which participates in the transformation of cholesterol into bile acids as a cause of increased serum transaminases in the absence of any other symptomatology. This treatable condition should be considered in the diagnosis of those patients where the cause of elevated transaminases remains obscure. (C) 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Revista:
ONCOTARGET
ISSN 1949-2553
Vol. 8
N° 42
Año 2017
Págs.71709 - 71724
Although T regulatory cells (Treg) are essential for the prevention of autoimmune diseases, their immunoregulatory function restrains the induction of immune responses against cancer. Thus, development of inhibitors of FOXP3, a key transcription factor for the immunosuppressive activity of Treg, might give new therapeutic opportunities. In a previous work we identified a peptide (named P60) able to enter into the cells, bind to FOXP3, and impair Treg activity in vitro and in vivo. Here we show that P60 binds to the intermediate region of FOXP3 and inhibits its homodimerization as well as its interaction with the transcription factor AML1. Alanine-scanning of P60 revealed the relevance of each position on FOXP3 binding, homodimerization, association with AML1 and inhibition of Treg activity. Introduction of alanine at positions 2, 5 and 11 improved the activity of the original P60, whereas alanine mutations at positions 1, 7, 8, 9, 10 and 12 were detrimental. Multiple mutation experiments allowed us to identify peptides with higher FOXP3 binding affinity and stronger biological activity than the original P60. Head to tail macrocyclization of peptide P60-D2A-S5A improved Treg inhibition and enhanced anti-tumor activity of anti-PD1 antibodies in a model of hepatocellular carcinoma. Introduction of a D-aminoacid at position 2 augmented significantly microsomal stability while maintained FOXP3 binding capacity and Treg inhibition in vitro. In vivo, when combined with the cytotoxic T-cell epitope AH1, it induced protection against CT26 tumor implantation. This study provides important structure¿function relationships essential for further drug design to inhibit Treg cells in cancer.
Revista:
JOURNAL OF CELLULAR PHYSIOLOGY
ISSN 0021-9541
Vol. 232
N° 9
Año 2017
Págs.2469 - 2477
Cardiotrophin-1 (CT-1) belongs to the IL-6 family of cytokines. Previous studies of our group revealed that CT-1 is a key regulator of glucose and lipid metabolism. The aim of the present study was to analyze the in vitro and in vivo effects of CT-1 on the production of several adipokines involved in body weight regulation, nutrient metabolism, and inflammation. For this purpose, 3T3-L1 adipocytes were incubated with recombinant protein CT-1 (rCT-1) (1-40 ng/ml) for 1 and 18 h. Moreover, the acute effects of rCT-1 administration (0.2 mg/kg, i.v.) for 30 min and 3 h on adipokines levels were also evaluated in high-fat fed obese mice. In 3T3-L1 adipocytes, rCT-1 treatment downregulated the expression and secretion of leptin, resistin, and visfatin. However, rCT-1 significantly stimulated apelin mRNA and secretion. rCT-1 (18 h) also promoted the activation by phosphorylation of AKT, ERK 1/2, and STAT3. Interestingly, pretreatment with the PI3K inhibitor LY294002 reversed the stimulatory effects of rCT-1 on apelin expression, suggesting that this pathway could be mediating the effects of rCT-1 on apelin production. In contrast, acute administration of rCT-1 (30 min and 3 h) to diet-induced obese mice downregulated leptin and resistin, without significantly modifying apelin or visfatin mRNA in adipose tissue. Furthermore, CT-1 null mice exhibited altered expression of adipokines in adipose tissue. The present study demonstrates that rCT-1 modulates the production of adipokines in vitro and in vivo, suggesting that the regulation of the secretory function of adipocytes could be involved in the metabolic actions of this cytokine. (C) 2016 Wiley Periodicals, Inc.
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 66
N° 1
Año 2017
Págs.S76 - S77
Revista:
CELL DEATH AND DISEASE
ISSN 2041-4889
Vol. 8
N° 10
Año 2017
Págs.e3083
The liver displays a remarkable regenerative capacity triggered upon tissue injury or resection. However, liver regeneration can be overwhelmed by excessive parenchymal destruction or diminished by pre-existing conditions hampering repair. Fibroblast growth factor 19 (FGF19, rodent FGF15) is an enterokine that regulates liver bile acid and lipid metabolism, and stimulates hepatocellular protein synthesis and proliferation. FGF19/15 is also important for liver regeneration after partial hepatectomy (PH). Therefore recombinant FGF19 would be an ideal molecule to stimulate liver regeneration, but its applicability may be curtailed by its short half-life. We developed a chimaeric molecule termed Fibapo in which FGF19 is covalently coupled to apolipoprotein A-I. Fibapo retains FGF19 biological activities but has significantly increased half-life and hepatotropism. Here we evaluated the pro-regenerative activity of Fibapo in two clinically relevant models where liver regeneration may be impaired: acetaminophen (APAP) poisoning, and PH in aged mice. The only approved therapy for APAP intoxication is N-acetylcysteine (NAC) and no drugs are available to stimulate liver regeneration. We demonstrate that Fibapo reduced liver injury and boosted regeneration in APAP-intoxicated mice. Fibapo improved survival of APAP-poisoned mice when given at later time points, when NAC is ineffective. Mechanistically, Fibapo accelerated recovery of hepatic glutathione levels, potentiated cell growth-related pathways and increased functional liver mass. When Fibapo was administered to old mice prior to PH, liver regeneration was markedly increased. The exacerbated injury developing in these mice upon PH was attenuated, and the hepatic biosynthetic capacity was enhanced. Fibapo reversed metabolic and molecular alterations that impede regeneration in aged livers. It reduced liver steatosis and downregulated p21 and hepatocyte nuclear factor 4 a (Hnf4a) levels, whereas it stimulated Foxm1b gene expression. Together our findings indicate that FGF19 variants retaining the metabolic and growth-promoting effects of this enterokine may be valuable for the stimulation of liver regeneration.
Revista:
GUT
ISSN 0017-5749
Vol. 66
N° 10
Año 2017
Págs.1818 - 1828
Objective Fibroblast growth factor 15/19 (FGF15/19), an enterokine that regulates synthesis of hepatic bile acids (BA), has been proposed to influence fat metabolism. Without FGF15/19, mouse liver regeneration after partial hepatectomy (PH) is severely impaired. We studied the role of FGF15/19 in response to a high fat diet (HFD) and its regulation by saturated fatty acids. We developed a fusion molecule encompassing FGF19 and apolipoprotein A-I, termed Fibapo, and evaluated its pharmacological properties in fatty liver regeneration.
Design Fgf15¿/¿ mice were fed a HFD. Liver fat and the expression of fat metabolism and endoplasmic reticulum (ER) stress-related genes were measured. Influence of palmitic acid (PA) on FGF15/19 expression was determined in mice and in human liver cell lines. In vivo half-life and biological activity of Fibapo and FGF19 were compared. Hepatoprotective and proregenerative activities of Fibapo were evaluated in obese db/db mice undergoing PH.
Results Hepatosteatosis and ER stress were exacerbated in HFD-fed Fgf15¿/¿ mice. Hepatic expression of Ppar¿2 was elevated in Fgf15¿/¿ mice, being reversed by FGF19 treatment. PA induced FGF15/19 expression in mouse ileum and human liver cells, and FGF19 protected from PA-mediated ER stress and cytotoxicity. Fibapo reduced liver BA and lipid accumulation, inhibited ER stress and showed enhanced half-life. Fibapo provided increased db/db mice survival and improved regeneration upon PH.
Conclusions FGF15/19 is essential for hepatic metabolic adaptation to dietary fat being a physiological regulator of Ppar¿2 expression. Perioperative administration of Fibapo improves fatty liver regeneration.
Revista:
ONCOTARGET
ISSN 1949-2553
Vol. 8
N° 25
Año 2017
Págs.40967 - 40981
The identification of new targets for systemic therapy of hepatocellular carcinoma (HCC) is an urgent medical need. Recently, we showed that hNatB catalyzes the N-alpha-terminal acetylation of 15% of the human proteome and that this action is necessary for proper actin cytoskeleton structure and function. In tumors, cytoskeletal changes influence motility, invasion, survival, cell growth and tumor progression, making the cytoskeleton a very attractive antitumor target. Here, we show that hNatB subunits are upregulated in in over 59% HCC tumors compared to non-tumor tissue and that this upregulation is associated with microscopic vascular invasion. We found that hNatB silencing blocks proliferation and tumor formation in HCC cell lines in association with hampered DNA synthesis and impaired progression through the S and the G2/M phases. Growth inhibition is mediated by the degradation of two hNatB substrates, tropomyosin and CDK2, which occurs when these proteins lack N-alpha-terminal acetylation. In addition, hNatB inhibition disrupts the actin cytoskeleton, focal adhesions and tight/adherens junctions, abrogating two proliferative signaling pathways, Hippo/YAP and ERK1/2. Therefore, inhibition of NatB activity represents an interesting new approach to treating HCC by blocking cell proliferation and disrupting actin cytoskeleton function.
Revista:
TRANSLATIONAL RESEARCH
ISSN 1931-5244
Vol. 188
Año 2017
Págs.80 - 91.e2
The aim of this nonrandomized, open label, phase 1 clinical trial was to evaluate the safety and the feasibility of the treatment with autologous bone marrow-derived endothelial progenitor cells (EPC) in decompensated liver cirrhosis. In addition, the changes in liver function and hepatic venous pressure gradient (HVPG) and their relation with the characteristics of the cellular product were analyzed. Twelve patients with Child-Pugh ¿8 liver cirrhosis underwent bone marrow harvest for ex vivo differentiation of EPC. The final product was administered through the hepatic artery in a single administration. Patients underwent clinical and radiologic follow-up for 12 months. The phenotype and the ability to produce cytokines and growth factors of the final cellular suspension were analyzed. Eleven patients were treated (feasibility 91%). No treatment-related severe adverse events were observed as consequence of any study procedure or treatment. Model for end-stage liver disease score improved significantly (P 0.042) in the first 90 days after cells administration and 5 of the 9 patients alive at 90 days showed a decreased of HVPG. There was a direct correlation between the expression of acetylated-low density lipoprotein and von Willebrand factor in the cellular product and the improvement in liver function and HVPG. The treatment with EPCs in patients with decompensated liver cirrhosis is safe and feasible and might have therapeutic potential. Patients receiving a higher amount
Revista:
TRANSLATIONAL RESEARCH
ISSN 1931-5244
Vol. 188
Año 2017
Págs.80 - 91
The aim of this nonrandomized, open label, phase 1 clinical trial was to evaluate the safety and the feasibility of the treatment with autologous bone marrow-derived endothelial progenitor cells (EPC) in decompensated liver cirrhosis. In addition, the changes in liver function and hepatic venous pressure gradient (HVPG) and their relation with the characteristics of the cellular product were analyzed. Twelve patients with Child-Pugh ¿8 liver cirrhosis underwent bone marrow harvest for ex vivo differentiation of EPC. The final product was administered through the hepatic artery in a single administration. Patients underwent clinical and radiologic follow-up for 12 months. The phenotype and the ability to produce cytokines and growth factors of the final cellular suspension were analyzed. Eleven patients were treated (feasibility 91%). No treatment-related severe adverse events were observed as consequence of any study procedure or treatment. Model for end-stage liver disease score improved significantly (P 0.042) in the first 90 days after cells administration and 5 of the 9 patients alive at 90 days showed a decreased of HVPG. There was a direct correlation between the expression of acetylated-low density lipoprotein and von Willebrand factor in the cellular product and the improvement in liver function and HVPG. The treatment with EPCs in patients with decompensated liver cirrhosis is safe and feasible and might have therapeutic potential. Patients receiving a higher amount
Revista:
HAEMATOLOGICA-THE HEMATOLOGY JOURNAL
ISSN 0390-6078
Vol. 103
N° 6
Año 2017
Págs.1065 - 1072
Regulatory T (Treg) cells can weaken antitumor immune responses, and inhibition of their function appears as a promising immunotherapeuticimmunotherapy therapeutic approach in cancer patients. Mice with targeted deletion of the gene encoding the Cl-HCO3-anion exchanger AE2 (also termed SLC4A2), a membrane-bound carrier involved in intracellular pH regulation, showed a progressive decrease in the number of Treg cells. We therefore challenged AE2 as a potential target for tumor immune therapy, and generated linear peptides designed to bind the third extracellular loop of AE2, which is crucial for its exchange activity. Peptide p17AE2 exhibited optimal interaction ability and indeed promoted apoptosis in mouse and human Treg cells, while activating effector T-cell function. Interestingly, this linear peptide also induced apoptosis in different types of human B-cell leukemia, lymphoma and multiple myeloma cell lines and primary malignant samples, while it showed only moderate effects on normal B lymphocytes. Finally, a macrocyclic peptide exhibiting increased stability in vivo was effective in mice xenografted with B-cell lymphoma. These data suggest that targeting the anion exchanger AE2 with specific peptides may represent an effective therapeutic approach in B-cell malignancies
Revista:
GASTROENTEROLOGY
ISSN 0016-5085
Vol. 152
N° 5
Año 2017
Págs.1203 - 1216.e15
BACKGROUND & AIMS: Liver regeneration after partial hepatectomy ( PH) increases the protein folding burden at the endoplasmic reticulum of remnant hepatocytes, resulting in induction of the unfolded protein response. We investigated the role of the core unfolded protein response transcription factor X-box binding protein 1 ( XBP1) in liver regeneration using genome-wide chromatin immunoprecipitation analysis. METHODS: We performed studies with C57Bl6-J ( control) and interleukin 6-knockout mice. Mice underwent PH or sham surgeries. In some mice, hepatic expression of XBP1 was knocked down by injection of adenoviral vectors encoding small hairpin RNAs against Xbp1 messenger RNA. Liver tissues were collected before surgery and at 6 and 48 hours after surgery and analyzed by chromatin immunoprecipitation followed by sequencing. We also performed functional analyses of HepG2 cells. RESULTS: Expression of XBP1 by hepatocytes increased immediately after PH ( priming phase of liver regeneration) in control mice, but this effect was delayed in interleukin 6-deficient mice. In mice with knockdown of XBP1, we observed of liver tissue persistent endoplasmic reticulum stress, defects in acute-phase response, and increased hepatocellular damage, compared with control mice. Chromatin immunoprecipitation analyses of liver tissue showed that at 6 hours after PH, liver XBP1 became bound to a large set of genes implicated in proteostasis, the acute-phase response, metabolism, and the DNA damage response ( DDR). At this time point, XBP1 bound the promoter of the signal transducer and activator of transcription 3 gene ( Stat3). Livers of XBP1-knockdown mice showed reduced expression of STAT3 and had lower levels of STAT3 phosphorylation at Ser727, a modification that promotes cell proliferation and the DDR. Regenerating livers from XBP1-knockdown mice expressed high levels of a marker of DNA double-strand breaks, phosphorylated histone 2A, member X ( H2AX), compared with control mice. The inhibition of XBP1 expression caused a reduced up-regulation of DDR messenger RNAs in regenerating hepatocytes. CONCLUSION: In livers of mice, we found that PH induces expression of XBP1, and that this activity requires interleukin 6. XBP1 expression regulates the unfolded protein response, acute-phase response, and DDR in hepatocytes. In regenerating livers, XBP1 deficiency leads to endoplasmic reticulum stress and DNA damage.
Revista:
PLOS ONE
ISSN 1932-6203
Vol. 11
N° 3
Año 2016
Págs.e0152031
Development of reporter systems for in vivo examination of IFN-ß induction or signaling of type I interferon (IFN-I) pathways is of great interest in order to characterize biological responses to different inducers such as viral infections. Several reporter mice have been developed to monitor the induction of both pathways in response to different agonists. However, alternative strategies that do not require transgenic mice breeding have to date not been reported. In addition, detection of these pathways in vivo in animal species other than mice has not yet been addressed. Herein we describe a simple method based on the use of an adeno-associated viral vector (AAV8-3xIRF-ISRE-Luc) containing an IFN-ß induction and signaling-sensitive promoter sequence controlling the expression of the reporter gene luciferase. This vector is valid for monitoring IFN-I responses in vivo elicited by diverse stimuli in different organs. Intravenous administration of the vector in C57BL/6 mice and Syrian hamsters was able to detect activation of the IFN pathway in the liver upon systemic treatment with different pro-inflammatory agents and infection with Newcastle disease virus (NDV). In addition, intranasal instillation of AAV8-3xIRF-ISRE-Luc showed a rapid and transient IFN-I response in the respiratory tract of mice infected with the influenza A/PR8/34 virus lacking the NS1 protein. In comparison, this response was delayed and exacerbated in mice infected with influenza A/PR/8 wild type virus. In conclusion, the AAV8-3xIRF-ISRE-Luc vector offers the possibility of detecting IFN-I activation in response to different stimuli and in different animal models with no need for reporter transgenic animals.
Revista:
ACTA PHYSIOLOGICA
ISSN 1748-1708
Vol. 217
N° 3
Año 2016
Págs.217 - 226
rCT-1 effects on ¿-Methyl-D-glucoside uptake were assessed in everted intestinal rings from wild-type and CT-1(-/-) mice and in Caco-2 cells. rCT-1 actions on SGLT-1 expression in brush border membrane vesicles and the identification of the potential signalling pathways involved were determined by Western blot.
RESULTS:
In vivo administration (0.2 mg kg(-1) ) of rCT-1 caused a significant decrease on ¿-Methyl-D-glucoside uptake in everted intestinal rings from wild-type and CT-1(-/-) mice after short-term and long-term treatments. Similarly, in vitro treatment (1-50 ng mL(-1) ) with rCT-1 reduced ¿-Methyl-D-glucoside uptake in everted intestinal rings. In Caco-2 cells, rCT-1 treatment (20 ng mL(-1) , 1 and 24 h) lowered apical uptake of ¿-Methyl-D-glucoside in parallel with a decrease on SGLT-1 protein expression. rCT-1 promoted the phosphorylation of STAT-3 after 5 and 15 min treatment, but inhibited the activation by phosphorylation of AMPK after 30 and 60 min. Interestingly, pre-treatment with the JAK/STAT inhibitor (AG490) and with the AMPK activator (AICAR) reversed the inhibitory effects of rCT-1 on ¿-Methyl-D-glucoside uptake. AICAR also prevented the inhibition of SGLT-1 observed in rCT-1-treated cells.
CONCLUSIONS:
CT-1 inhibits intestinal sugar absorption by the reduction of SGLT-1 levels through the AMPK pathway, which could also contribute to explain the hypoglycaemic and anti-obesity properties of CT-1.
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 64
N° Supl. 2
Año 2016
Págs.S184
Revista:
EUROPEAN JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY
ISSN 0954-691X
Vol. 28
N° 2
Año 2016
Págs.139 - 145
Objective Hypermetabolism in cirrhosis is associated with a high risk of complications and mortality. However, studies about underlying mechanisms are usually focussed on isolated potential determinants and specific etiologies, with contradictory results. We aimed at investigating differences in nutrition, metabolic hormones, and hepatic function between hypermetabolic and nonhypermetabolic men with cirrhosis of the liver. Patients and methods We prospectively enrolled 48 male cirrhotic inpatients. We evaluated their resting energy expenditure (REE) and substrate utilization by indirect calorimetry, body composition by dual-energy X-ray absorptiometry, liver function, and levels of major hormones involved in energy metabolism by serum sample tests. Patients with ascites, specific metabolic disturbances, and hepatocellular carcinoma were excluded. Results REE and REE adjusted per fat-free mass (FFM) were significantly increased in cirrhotic patients. Overall, 58.3% of cirrhotic patients were classified as hypermetabolic. Groups did not differ significantly in age, etiology of cirrhosis, liver function, presence of ascites, use of diuretics, â-blockers, or presence of transjugular intrahepatic portosystemic shunts. Hypermetabolic cirrhotic patients had lower weight, BMI (P< 0.05), nonprotein respiratory quotient (P< 0.01), leptin (P<0.05), and leptin adjusted per fat mass (FM) (P<0.05), but higher FFM% (P< 0.05) and insulin resistance [homeostatic model assessment-insulin resistance (HOMA-IR)] (P<0.05). Only HOMA-IR, leptin/FM, and FFM% were independently related to the presence of hypermetabolism. Conclusion Hypermetabolic cirrhotic men are characterized by lower weight, higher FFM%, insulin resistance, and lower leptin/FM when compared with nonhypermetabolic men. HOMA-IR, FFM%, and leptin/FM were independently associated with hypermetabolism, and may serve as easily detectable markers of this condition in daily clinical practice.
Revista:
JOURNAL OF MEDICAL VIROLOGY
ISSN 0146-6615
Vol. 88
N° 5
Año 2016
Págs.843 - 851
Viral clearance during acute hepatitis C virus (HCV) infection is associated with the induction of potent antiviral T-cell responses. Since dendritic cells (DC) are essential in the activation of primary T-cell responses, gene expression was analyzed in DC from patients during acute HCV infection. By using microarrays, gene expression was compared in resting and activated peripheral blood plasmacytoid (pDC) and myeloid (mDC) DC from acute HCV resolving patients (AR) and from patients who become chronically infected (ANR), as well as in healthy individuals (CTRL) and chronically-infected patients (CHR). For pDC, a high number of upregulated genes was found in AR patients, irrespective of DC stimulation. However, for mDC, most evident differences were detected after DC stimulation, again corresponding to upregulated genes in AR patients. Divergent behavior of ANR was also observed when analyzing DC from CTRL and CHR, with ANR patients clustering again apart from these groups. These differences corresponded to metabolism-associated genes and genes belonging to pathways relevant for DC activation and cytokine responses. Thus, upregulation of relevant genes in DC during acute HCV infection may determine viral clearance, suggesting that dysfunctional DC may be responsible for the lack of efficient T-cell responses which lead to chronic HCV infection.
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 64
N° Supl. 1
Año 2016
Págs.266A
Autores:
Monte, M. J.; Alonso, M.; Briz, O.; et al.
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 64
N° 2, Supl.
Año 2016
Págs.S301
Revista:
ONCOIMMUNOLOGY
ISSN 2162-402X
Vol. 5
N° 8
Año 2016
Págs.e1196309
Scavenger receptor class B type I (SR-B1) binds pathogen-associated molecular patterns participating in the regulation of the inflammatory reaction but there is no information regarding potential interactions between SR-B1 and the interferon system. Herein, we report that SR-B1 ligands strongly regulate the transcriptional response to interferon ¿ (IFN¿) and enhance its antiviral and antitumor activity. This effect was mediated by the activation of TLR2 and TLR4 as it was annulled by the addition of anti-TLR2 or anti-TLR4 blocking antibodies. In vivo, we maximized the antitumor activity of IFN¿ co-expressing in the liver a SR-B1 ligand and IFN¿ by adeno-associated viruses. This gene therapy strategy eradicated liver metastases from colon cancer with reduced toxicity. On the other hand, genetic and pharmacological inhibition of SR-B1 blocks the clathrin-dependent interferon receptor recycling pathway with a concomitant reduction in IFN¿ signaling and bioactivity. This effect can be applied to enhance cancer immunotherapy with oncolytic viruses. Indeed, SR-B1 antagonists facilitate replication of oncolytic viruses amplifying their tumoricidal potential. In conclusion, SR-B1 agonists behave as IFN¿ enhancers while SR-B1 inhibitors dampen IFN¿ activity. These results demonstrate that SR-B1 is a suitable pharmacology target to enhance cancer immunotherapy based on IFN¿ and oncolytic viruses.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 1600-0641
Vol. 64
N° 2
Año 2016
Págs.419-26
Our data demonstrate that AAV8-AAT-ATP7B-mediated gene therapy provides long-term correction of copper metabolism in a clinically relevant animal model of WD providing support for future translational studies.
Autores:
Erice, O.; Muñoz-Garrido, P.; Vaquero, J.; et al.
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 64
N° Supl.2
Año 2016
Págs.S639 - S640
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 65
N° 4
Año 2016
Págs.776 - 783
BACKGROUND & AIMS:
Acute intermittent porphyria (AIP) results from porphobilinogen deaminase (PBGD) haploinsufficiency, which leads to hepatic over-production of the neurotoxic heme precursors porphobilinogen (PBG) and delta-aminolevulinic acid (ALA) and the occurrence of neurovisceral attacks. Severe AIP is a devastating disease that can only be corrected by liver transplantation. Gene therapy represents a promising curative option. The objective of this study was to investigate the safety of a recombinant adeno-associated vector expressing PBGD (rAAV2/5-PBGD) administered for the first time in humans for the treatment of AIP.
METHODS:
In this phase I, open label, dose-escalation, multicenter clinical trial, four cohorts of 2 patients each received a single intravenous injection of the vector ranging from 5×10(11) to 1.8×10(13) genome copies/kg. Adverse events and changes in urinary PBG and ALA and in the clinical course of the disease were periodically evaluated prior and after treatment. Viral shedding, immune response against the vector and vector persistence in the liver were investigated.
RESULTS:
Treatment was safe in all cases. All patients developed anti-AAV5 neutralizing antibodies but no cellular responses against AAV5 or PBGD were observed. There was a trend towards a reduction of hospitalizations and heme treatments, although ALA and PBG levels remained unchanged. Vector genomes and transgene expression could be detected in the liver one year after therapy.
CONCLUSIONS:
rAAV2/5-PBGD administration is safe but AIP metabolic correction was not achieved at the doses tested in this trial. Notwithstanding, the treatment had a positive impact in clinical outcomes in most patients.
LAY SUMMARY:
Studies in an acute intermittent porphyria (AIP) animal model have shown that gene delivery of PBGD to hepatocytes using an adeno-associated virus vector (rAAV2/5-PBG) prevent mice from suffering porphyria acute attacks. In this phase I, open label, dose-escalation, multicenter clinical trial we show that the administration of rAAV2/5-PBGD to patients with severe AIP is safe but metabolic correction was not achieved at the doses tested; the treatment, however, had a positive but heterogeneous impact on clinical outcomes among treated patients and 2 out of 8 patients have stopped hematin treatment.
CLINICAL TRIAL NUMBER:
The observational phase was registered at Clinicaltrial.gov as NCT 02076763. The interventional phase study was registered at EudraCT as n° 2011-005590-23 and at Clinicaltrial.gov as NCT02082860.
Autores:
Gil-Farina, I.; Fronza, R.; Kaeppel, C.; et al.
Revista:
MOLECULAR THERAPY
ISSN 1525-0016
Vol. 24
N° 6
Año 2016
Págs.1100 - 1105
Recombinant adeno-associated viral vectors (rAAV) currently constitute a real therapeutic strategy for the sustained correction of diverse genetic conditions. Though a wealth of preclinical and clinical studies have been conducted with rAAV, the oncogenic potential of these vectors is still controversial, particularly when considering liver-directed gene therapy. Few preclinical studies and the recent discovery of incomplete wild-type AAV2 genomes integrated in human hepatocellular carcinoma biopsies have raised concerns on rAAV safety. In the present study, we have characterized the integration of both complete and partial rAAV2/5 genomes in nonhuman primate tissues and clinical liver biopsies from a trial aimed to treat acute intermittent porphyria. We applied a new multiplex linear amplification-mediated polymerase chain reaction (PCR) assay capable of detecting integration events that are originated throughout the rAAV genome. The integration rate was low both in nonhuman primates and patient's samples. Importantly, no integration clusters or events were found in genes previously reported to link rAAV integration with hepatocellular carcinoma development, thus showing the absence of genotoxicity of a systemically administered rAAV2/5 in a large animal model and in the clinical context.
Revista:
ONCOGENE
ISSN 0950-9232
Vol. 35
N° 36
Año 2016
Págs.4719 - 4729
Resisting death is a central hallmark of cancer cells. Tumors rely on a number of genetic mechanisms to avoid apoptosis, and alterations in mRNA alternative splicing are increasingly recognized to have a role in tumorigenesis. In this study, we identify the splicing regulator SLU7 as an essential factor for the preservation of hepatocellular carcinoma (HCC) cells viability. Compared with hepatocytes, SLU7 expression is reduced in HCC cells; however, further SLU7 depletion triggered autophagy-related cellular apoptosis in association with the overproduction of reactive oxygen species. Remarkably, these responses were not observed in primary human hepatocytes or in the well-differentiated HepaRG cell line. Mechanistically, we demonstrate that SLU7 binds the C13orf25 primary transcript in which the polycistronic oncomir miR-17-92 cluster is encompassed, and is necessary for its processing and expression. SLU7 knockdown altered the splicing of the C13orf25 primary transcript, and markedly reduced the expression of its miR-17, miR-20 and miR-92a constituents. This led to the upregulation of CDKN1A (P21) and BCL2L11 (BIM) expression, two bona fide targets of the miR-17-92 cluster and recognized mediators of its pro-survival and tumorigenic activity. Interestingly, altered splicing of miR-17-92 and downregulation of miR-17 and miR-20 were not observed upon SLU7 knockdown in non-transformed hepatocytes, but was found in other (HeLa, H358) but not in all (Caco2) non-hepatic tumor cells. The functional relevance of miR-17-92 dysregulation upon SLU7 knockdown was established when oxidative stress, autophagy and apoptosis were reversed by co-transfection of HCC cells with a miR-17 mimic. Together, these findings indicate that SLU7 is co-opted by HCC cells and other tumor cell types to maintain survival, and identify this splicing regulator as a new determinant for the expression of the oncogenic miR-17-92 cluster. This novel mechanism may be exploited for the development of antitumoral strategies in cancers displaying such SLU7-miR-17-92 crosstalk.
Revista:
JOURNAL OF IMMUNOLOGY
ISSN 0022-1767
Vol. 197
N° 6
Año 2016
Págs.2145 - 2156
The etiopathogenesis of autoimmune hepatitis (AIH) remains poorly understood. In this study, we sought to develop an animal model of human AIH to gain insight into the immunological mechanisms driving this condition. C57BL/6 mice were i.v. injected with adeno-associated viral vectors encodingmurine IL-12 or luciferase under the control of a liver-specific promoter. Organ histology, response to immunosuppressive therapy, and biochemical and immunological parameters, including Ag-specific humoral and cellular response, were analyzed. Mechanistic studies were carried out using genetically modified mice and depletion of lymphocyte subpopulations. Adeno-associated virus IL-12-treated mice developed histological, biochemical, and immunological changes resembling type 1 AIH, including marked and persistent liver mononuclear cell infiltration, hepatic fibrosis, hypergammaglobulinemia, antinuclear and anti-smooth muscle actin Abs, and disease remission with immunosuppressive drugs. Interestingly, transgenic IL-12 was short-lived, but endogenous IL-12 expression was induced, and both IL-12 and IFN-g remained elevated during the entire study period. IFN-g was identified as an essential mediator of liver damage, and CD4 and CD8 T cells but not NK, NKT, or B cells were essential executors of hepatic injury. Furthermore, both MHC class I and MHC class II expression was upregulated at the hepatocellular membrane, and induction of autoreactive liver-specific T cells was detected. Remarkably, although immunoregulatory mechanisms were activated, they only partially mitigated liver damage. Thus, low and transient expression of transgenic IL-12 in hepatocytes causes loss of tolerance to hepatocellular Ags, leading to chronic hepatitis resembling human AIH type 1. This model provides a practical tool to explore AIH pathogenesis and novel therapies.
Revista:
JOURNAL OF INNATE IMMUNITY
ISSN 1662-811X
Vol. 7
N° 5
Año 2015
Págs.466 - 481
RIG-I-like receptors (RLRs) are cellular sensor proteins that detect certain RNA species produced during viral infections. RLRs activate a signaling cascade that results in the production of IFN-ß as well as several other cytokines with antiviral and proinflammatory activities. We explored the potential of different constructs based on RLRs to induce the IFN-ß pathway and create an antiviral state in type I IFN-unresponsive models. A chimeric construct composed of RIG-I 2CARD and the first 200 amino acids of MAVS (2CARD-MAVS200) showed an enhanced ability to induce IFN-ß when compared to other stimulatory constructs. Furthermore, this human chimeric construct showed a superior ability to activate IFN-ß expression in cells from various species. This construct was found to overcome the restrictions of blocking IFN-ß induction or signaling by a number of viral IFN-antagonist proteins. Additionally, the antiviral activity of this chimera was demonstrated in influenza virus and HBV infection mouse models using adeno-associated virus (AAV) vectors as a delivery vehicle. We propose that AAV vectors expressing 2CARD-MAVS200 chimeric protein can reconstitute IFN-ß induction and recover a partial antiviral state in different models that do not respond to recombinant IFN-ß treatment.
Revista:
ONCOTARGET
ISSN 1949-2553
Vol. 6
N° 30
Año 2015
Págs.28588 - 28606
Primary biliary cirrhosis (PBC) is a chronic cholestatic disease of unknown etiopathogenesis showing progressive autoimmune-mediated cholangitis. In PBC patients, the liver and lymphocytes exhibit diminished expression of AE2/SLC4A2, a Cl-/HCO3- anion exchanger involved in biliary bicarbonate secretion and intracellular pH regulation. Decreased AE2 expression may be pathogenic as Ae2a,b(-/-) mice reproduce hepatobiliary and immunological features resembling PBC. To understand the role of AE2 deficiency for autoimmunity predisposition we focused on the phenotypic changes of T cells that occur over the life-span of Ae2a,b(-/-) mice. At early ages (1-9 months), knockout mice had reduced numbers of intrahepatic T cells, which exhibited increased activation, programmed-cell-death (PD)-1 expression, and apoptosis. Moreover, young knockouts had upregulated PD-1 ligand (PD-L1) on bile-duct cells, and administration of neutralizing anti-PD-L1 antibodies prevented their intrahepatic T-cell deletion. Older (¿ 10 months) knockouts, however, showed intrahepatic accumulation of cytotoxic CD8(+) T cells with downregulated PD-1 and diminished apoptosis. In-vitro DNA demethylation with 5-aza-2'-deoxycytidine partially reverted PD-1 downregulation of intrahepatic CD8(+) T cells from aged knockouts.
CONCLUSION:
Early in life, AE2 deficiency results in intrahepatic T-cell activation and PD-1/PD-L1 mediated deletion. With aging, intrahepatic CD8+ T cells epigenetically suppress PD-1, and their consequential expansion and further activation favor autoimmune cholangitis.
Revista:
HAEMATOLOGICA
ISSN 1138-0381
Vol. 100
N° 8
Año 2015
Págs.1014-1022
Interferon-¿ is a potent antiviral agent and a vigorous adjuvant in the induction of T-cell responses but its use is limited by hematologic toxicity. Interferon-¿ alters hematopoietic stem cell dormancy and impairs myelocytic and erythrocytic/megakaryocytic differentiation from hematopoietic progenitors. However, the effect of chronic interferon-¿ exposure on hematopoietic precursors has still not been well characterized. Here, we transduced the liver of mice with an adenoassociated vector encoding interferon-¿ to achieve sustained high serum levels of the cytokine. The bone marrow of these animals showed diminished long-term and short-term hematopoietic stem cells, reduction of multipotent progenitor cells, and marked decrease of B cells, but significant increase in the proportion of CD8(+) and CD4(+)CD8(+) T cells. Upon adoptive transfer to RAG(-/-) mice, bone marrow cells from interferon-¿-treated animals generated CD4(+) and CD8(+) T cells while CD19(+), CD11b(+) and NK1.1(+) lineages failed to develop. These effects are associated with the transcriptional downregulation of transcription factors involved in B-cell differentiation and modulation of key factors for T-cell development. Thus, sustained interferon-¿ exposure causes hematopoietic stem cells exhaustion and drives common lymphoid progenitors towards T-cell generation.
Revista:
MOLECULAR THERAPY. METHODS & CLINICAL DEVELOPMENT
ISSN 2329-0501
Vol. 2
Año 2015
Págs.15006
The lack of antiviral cellular immune responses in patients with chronic hepatitis C virus (HCV) infection suggests that T-cell vaccines may provide therapeutic benefit. Due to the central role that dendritic cells (DC) play in the activation of T-cell responses, our aim was to carry out a therapeutic vaccination clinical trial in HCV patients using DC. Five patients with chronic HCV infection were vaccinated with three doses of 5¿×¿10(6) or 10(7) autologous DC transduced with a recombinant adenovirus encoding NS3 using the adapter protein CFh40L, which facilitates DC transduction and maturation. No significant adverse effects were recorded after vaccination. Treatment caused no changes in serum liver enzymes nor in viral load. Vaccination induced weak but consistent expansion of T-cell responses against NS3 and adenoviral antigens. Patients' DC, as opposed to murine DC or DC from healthy subjects, secreted high IL-10 levels after transduction, inducing the activation of IL-10-producing T cells. IL-10 blockade during vaccine preparation restored its ability to stimulate anti-NS3 Th1 responses. Thus, vaccination with adenovirus-transduced DC is safe and induces weak antiviral immune responses. IL-10 associated with vaccine preparation may be partly responsible for these effects, suggesting that future vaccines should consider concomitant inhibition of this cytokine
Revista:
MOLECULAR CANCER
ISSN 1476-4598
Vol. 14
Año 2015
Págs.210
Background: The limited efficacy of current treatments against pancreatic cancer has prompted the search of new alternatives such as virotherapy. Activation of the immune response against cancer cells is emerging as one of the main mechanisms of action of oncolytic viruses (OV). Direct oncolysis releases tumor antigens, and viral replication within the tumor microenvironment is a potent danger signal. Arming OV with immunostimulatory transgenes further enhances their therapeutic effect. However, standard virotherapy protocols do not take full advantage of OV as cancer vaccines because repeated viral administrations may polarize immune responses against strong viral antigens, and the rapid onset of neutralizing antibodies limits the efficacy of redosing. An alternative paradigm based on sequential combination of antigenically distinct OV has been recently proposed.
Methods: We have developed a protocol consisting of sequential intratumor administrations of new Adenovirus (Ad) and Newcastle Disease Virus (NDV)-based OV encoding the immunostimulatory cytokine oncostatin M (OSM). Transgene expression, toxicity and antitumor effect were evaluated using an aggressive orthotopic pancreatic cancer model in Syrian hamsters, which are sensitive to OSM and permissive for replication of both OVs.
Results: NDV-OSM was more cytolytic, whereas Ad-OSM caused higher OSM expression in vivo. Both viruses achieved only a marginal antitumor effect in monotherapy. In addition, strong secretion of OSM in serum limited the maximal tolerated dose of Ad-OSM. In contrast, moderate doses of Ad-OSM followed one week later by NDV-OSM were safe, showed a significant antitumor effect and stimulated immune responses against cancer cells. Similar efficacy was observed when the order of virus administrations was reversed.
Conclusion: Sequential administration of oncolytic Ad and NDV encoding OSM is a promising approach against pancreatic cancer.
Revista:
INTERNATIONAL JOURNAL OF CANCER
ISSN 0020-7136
Vol. 136
N° 10
Año 2015
Págs.2469 - 2475
Fibroblast growth factor 15 (FGF15), FGF19 in humans, is a gut-derived hormone and a key regulator of bile acids and carbohydrate metabolism. FGF15 also participates in liver regeneration after partial hepatectomy inducing hepatocellular proliferation. FGF19 is overexpressed in a significant proportion of human hepatocellular carcinomas (HCC), and activation of its receptor FGFR4 promotes HCC cell growth. Here we addressed for the first time the role of endogenous Fgf15 in hepatocarcinogenesis. Fgf15(+/+) and Fgf15(-/-) mice were subjected to a clinically relevant model of liver inflammation and fibrosis-associated carcinogenesis. Fgf15(-/-) mice showed less and smaller tumors, and histological neoplastic lesions were also smaller than in Fgf15(+/+) animals. Importantly, ileal Fgf15 mRNA expression was enhanced in mice undergoing carcinogenesis, but at variance with human HCC it was not detected in liver or HCC tissues, while circulating FGF15 protein was clearly upregulated. Hepatocellular proliferation was also reduced in Fgf15(-/-) mice, which also expressed lower levels of the HCC marker alpha-fetoprotein (AFP). Interestingly, lack of FGF15 resulted in attenuated fibrogenesis. However, in vitro experiments showed that liver fibrogenic stellate cells were not direct targets for FGF15/FGF19. Conversely we demonstrate that FGF15/FGF19 induces the expression of the pro-fibrogenic and pro-tumorigenic connective tissue growth factor (CTGF) in hepatocytes. These findings suggest the existence of an FGF15-triggered CTGF-mediated paracrine action on stellate cells, and an amplification mechanism for the hepatocarcinogenic effects of FGF15 via CTGF production. In summary, our observations indicate that ileal FGF15 may contribute to HCC development in a context of chronic liver injury and fibrosis. What's new? Fibroblast growth factor-19 (FGF19), in rodents called FGF15, is a gut-derived hormone recently implicated as a driver gene in liver carcinogenesis. Here, the authors show that Fgf15(-/-) mice develop less hepatocellular carcinoma and less liver fibrosis as compared to Fgf15(+/+) littermates, underscoring the important role of the factor in liver damage and cancer development. Interestingly, Fgf15 expression is not detected in injured liver or carcinoma tissue, but is upregulated in the ileum and blood, pointing to a new gut-liver axis involved in hepatocarcinogenesis.
Revista:
NATURE REVIEWS GASTROENTEROLOGY AND HEPATOLOGY
ISSN 1759-5045
Vol. 12
N° 12
Año 2015
Págs.681 - 700
Advanced hepatocellular carcinoma (HCC) is a serious therapeutic challenge and targeted therapies only provide a modest benefit in terms of overall survival. Novel approaches are urgently needed for the treatment of this prevalent malignancy. Evidence demonstrating the antigenicity of tumour cells, the discovery that immune checkpoint molecules have an essential role in immune evasion of tumour cells, and the impressive clinical results achieved by blocking these inhibitory receptors, are revolutionizing cancer immunotherapy. Here, we review the data on HCC immunogenicity, the mechanisms for HCC immune subversion and the different immunotherapies that have been tested to treat HCC. Taking into account the multiplicity of hyperadditive immunosuppressive forces acting within the HCC microenvironment, a combinatorial approach is advised. Strategies include combinations of systemic immunomodulation and gene therapy, cell therapy or virotherapy.
Revista:
JOURNAL OF IMMUNOLOGY
ISSN 0022-1767
Vol. 195
N° 7
Año 2015
Págs.3180 - 3189
Regulatory T cell (Treg) activity is modulated by a cooperative complex between the transcription factor NFAT and FOXP3, a lineage specification factor for Tregs. FOXP3/NFAT interaction is required to repress expression of IL-2, upregulate expression of the Treg markers CTLA4 and CD25, and confer suppressor function to Tregs. However, FOXP3 is expressed transiently in conventional CD4+ T cells upon TCR stimulation and may lead to T cell hyporesponsiveness. We found that a short synthetic peptide able to inhibit FOXP3/NFAT interaction impaired suppressor activity of conventional Tregs in vitro. Specific inhibition of FOXP3/NFAT interaction with this inhibitory peptide revealed that FOXP3 downregulates NFAT-driven promoter activity of CD40L and IL-17. Inhibition of FOXP3/NFAT interaction upregulated CD40L expression on effector T cells and enhanced T cell proliferation and IL-2, IFN-¿, IL-6, or IL-17 production in response to TCR stimulation. The inhibitory peptide impaired effector T cell conversion into induced Tregs in the presence of TGF-ß. Moreover, in vivo peptide administration showed antitumor efficacy in mice bearing Hepa129 or TC1 tumor cells when combined with sorafenib or with an antitumor vaccine, respectively. Our results suggest that inhibition of NFAT/FOXP3 interaction might improve antitumor immunotherapies.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 1600-0641
Vol. 63
N° 2
Año 2015
Págs.329-336
BACKGROUND & AIMS:
Current hepatitis B virus (HBV) management is challenging as treatment with nucleos(t)ide analogues needs to be maintained indefinitely and because interferon (IFN)-¿ therapy is associated with considerable toxicity. Previously, we showed that linking IFN¿ to apolipoprotein A-I generates a molecule (IA) with distinct antiviral and immunostimulatory activities which lacks the hematological toxicity of IFN¿.
METHODS:
Here, we analyse the antiviral potential of an adeno-associated vector encoding IFN¿ fused to apolipoprotein A-I (AAV-IA) in comparison to a vector encoding only IFN¿ (AAV-IFN) in two animal models of chronic hepadnavirus infection.
RESULTS:
In HBV transgenic mice, we found that both vectors induced marked reductions in serum and liver HBV DNA and in hepatic HBV RNA but AAV-IFN caused lethal pancytopenia. Woodchucks with chronic hepatitis virus (WHV) infection that were treated by intrahepatic injection of vectors encoding the woodchuck sequences (AAV-wIFN or AAV-wIA), experienced only a slight reduction of viremia which was associated with hematological toxicity and high mortality when using AAV-wIFN, while AAV-wIA was well tolerated. However, when we tested AAV-wIA or a control vector encoding woodchuck apolipoprotein A-I (AAV-wApo) in combination with entecavir, we found that AAV-wApo-treated animals exhibited an immediate rebound of viral load upon entecavir withdrawal while, in AAV-wIA-treated woodchucks, viremia and antigenemia remained at low levels for several weeks following entecavir interruption.
CONCLUSIONS:
Treatment with AAV-IA is safe and elicits antiviral effects in animal models with difficult to treat chronic hepadnavirus infection. AAV-IA in combination with nucleos(t)ide analogues represents a promising approach for the treatment of HBV infection in highly viremic patients.
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 62
N° 1
Año 2015
Págs.166 - 178
Matrix metalloproteinases (MMPs) participate in tissue repair after acute injury, but also participate in cancer by promoting a protumorigenic microenvironment. Previously, we reported on a key role for MMP10 in mouse liver regeneration. Herein, we investigated MMP10 expression and function in human hepatocellular carcinoma (HCC) and diethylnitrosamine (DEN)-induced mouse hepatocarcinogenesis. MMP10 was induced in human and murine HCC tissues and cells. MMP10-deficient mice showed less HCC incidence, smaller histological lesions, reduced tumor vascularization, and less lung metastases. Importantly, expression of the protumorigenic, C-X-C chemokine receptor-4 (CXCR4), was reduced in DEN-induced MMP10-deficient mice livers. Human HCC cells stably expressing MMP10 had increased CXCR4 expression and migratory capacity. Pharmacological inhibition of CXCR4 significantly reduced MMP10-stimulated HCC cell migration. Furthermore, MMP10 expression in HCC cells was induced by hypoxia and the CXCR4 ligand, stromal-derived factor-1 (SDF1), through the extracellular signal-regulated kinase 1/2 pathway, involving an activator protein 1 site in MMP10 gene promoter.
CONCLUSION:
MMP10 contributes to HCC development, participating in tumor angiogenesis, growth, and dissemination. We identified a new reciprocal crosstalk between MMP10 and the CXCR4/SDF1 axis contributing to HCC progression and metastasis. To our knowledge, this is the first report addressing the role of a MMP in hepatocarcinogenesis in the corresponding genetic mouse model.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 62
N° Supl. 2
Año 2015
Págs.S242
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 62
N° Supl. 2
Año 2015
Págs.S344 - S345
Revista:
CELLULAR AND MOLECULAR LIFE SCIENCES
ISSN 1420-682X
Vol. 71
N° 23
Año 2014
Págs.4637 - 4651
We report a new method to generate high-expressing mammalian cell lines in a quick and efficient way. For that purpose, we developed a master cell line (MCL) containing an inducible alphavirus vector expressing GFP integrated into the genome. In the MCL, recombinant RNA levels increased >4,600-fold after induction, due to a doxycycline-dependent RNA amplification loop. The MCL maintained inducibility and expression during 50 passages, being more efficient for protein expression than a conventional cell line. To generate new cell lines, mutant LoxP sites were inserted into the MCL, allowing transgene and selection gene exchange by Cre-directed recombination, leading to quick generation of inducible cell lines expressing proteins of therapeutic interest, like human cardiotrophin-1 and oncostatin-M at several mg/l/24 h. These proteins contained posttranslational modifications, showed bioactivity, and were efficiently purified. Remarkably, this system allowed production of toxic proteins, like oncostatin-M, since cells able to express it could be grown to the desired amount before induction. These cell lines were easily adapted to growth in suspension, making this methodology very attractive for therapeutic protein production.
Revista:
EUROPEAN JOURNAL OF IMMUNOLOGY
ISSN 0014-2980
Vol. 44
N° 5
Año 2014
Págs.1341 - 1351
Mitogenic stimulation of lymphocytes involves alkalinization of intracellular pH (pHi ). Subsequent pHi regulation may involve HCO3 (-) extrusion through Cl(-) /HCO3 (-) exchangers and/or Na(+) -HCO3 (-) co-transporters with acid-loading capability. Abnormalities in these mechanisms could result in immune dysfunctions, as suggested by the CD8(+) T-cell expansion encountered in mice lacking Ae2 (a widely expressed acid loader with electroneutral and Na(+) -independent Cl(-) /HCO3 (-) anion-exchange activity). Here we report that CD8(+) T cells but not CD4(+) T cells or other lymphocyte populations, are crucially dependent on Ae2 for pHi regulation. While total lymphocytes (including isolated CD4(+) T cells) exhibit Ae1 expression and Na(+) -HCO3 (-) co-transport with acidifying potential, CD8(+) T cells lack these acid-loading mechanisms. In Ae2-KO mice, CD4(+) but not CD8(+) T cells upregulate these potential Ae2 surrogates. As a consequence, Ae2-KO CD8(+) T cells exhibit alkalinized pHi , and dramatically increase their pHi upon CD3 stimulation. Moreover, stimulated Ae2-deficient CD8(+) T cells show enhanced intracellular production of IL-2 and membrane expression of its receptor IL-2R¿, together with increased cell proliferation and activation. These findings demonstrate that CD8(+) T cells are critically dependent on Ae2 for pHi homeostasis and tuning of cell proliferation and activation. Ae2 thus constitutes a novel target to modulate CD8(+) T-cell responses.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 1600-0641
Vol. 60
N° 5
Año 2014
Págs.1017 - 1025
Background & Aims: Cardiotrophin-1 (CT-1) is a hepatoprotective cytokine that modulates fat and glucose metabolism in muscle and adipose tissue. Here we analyzed the changes in hepatic fat stores induced by recombinant CT-1 (rCT-1) and its therapeutic potential in non-alcoholic fatty liver disease (NAFLD).
Methods: rCT-1 was administered to two murine NAFLD models: ob/ob and high fat diet-fed mice. Livers were analyzed for lipid composition and expression of genes involved in fat metabolism. We studied the effects of rCT-1 on lipogenesis and fatty acid (FA) oxidation in liver cells and the ability of dominant negative inhibitor of AMP-activated protein kinase (AMPK) to block these effects.
Results: CT-1 was found to be upregulated in human and murine steatotic livers. In two NAFLD mouse models, treatment with rCT-1 for 10 days induced a marked decrease in liver triglyceride content with augmented proportion of poly-unsaturated FA and reduction of monounsaturated species. These changes were accompanied by attenuation of inflammation and improved insulin signaling. Chronic administration of rCT-1 caused downregulation of lipogenic genes and genes involved in FA import to hepatocytes together with amelioration of ER stress, elevation of NAD(+)/ NADH ratio, phosphorylation of LKB1 and AMPK, increased expression and activity of sirtuin1 (SIRT1) and upregulation of genes mediating FA oxidation. rCT-1 potently inhibited de novo lipogenesis and stimulated FA oxidation in liver cells both in vitro and in vivo. In vitro studies showed that these effects are mediated by activated AMPK.
Conclusions: rCT-1 resolves hepatic steatosis in obese mice by mechanisms involving AMPK activation. rCT-1 deserves consideration as a potential therapy for NAFLD. (c) 2013 European Association for the Study of the Liver.
Revista:
JOURNAL OF LIPID RESEARCH
ISSN 0022-2275
Vol. 55
N° 12
Año 2014
Págs.2634 - 2643
Cardiotrophin-1 (CT-1) is a cytokine with antiobesity properties and with a role in lipid metabolism regulation and adipose tissue function. The aim of this study was to analyze the molecular mechanisms involved in the lipolytic actions of CT-1 in adipocytes. Recombinant CT-1 (rCT-1) effects on the main proteins and signaling pathways involved in the regulation of lipolysis were evaluated in 3T3-L1 adipocytes and in mice. rCT-1 treatment stimulated basal glycerol release in a concentration- and time-dependent manner in 3T3-L1 adipocytes. rCT-1 (20 ng/ml for 24 h) raised cAMP levels, and in parallel increased protein kinase (PK)A-mediated phosphorylation of perilipin and hormone sensitive lipase (HSL) at Ser660. siRNA knock-down of HSL or PKA, as well as pretreatment with the PKA inhibitor H89, blunted the CT-1-induced lipolysis, suggesting that the lipolytic action of CT-1 in adipocytes is mainly mediated by activation of HSL through the PKA pathway. In ob/ob mice, acute rCT-1 treatment also promoted PKA-mediated phosphorylation of perilipin and HSL at Ser660 and Ser563, and increased adipose triglyceride lipase (desnutrin) content in adipose tissue. These results showed that the ability of CT-1 to regulate the activity of the main lipases underlies the lipolytic action of this cytokine in vitro and in vivo, and could contribute to CT-1 antiobesity effects.
Revista:
JOURNAL OF HEPATOLOGY (ONLINE)
ISSN 0168-8278
Vol. 60
N° 3
Año 2014
Págs.482 - 489
BACKGROUND & AIMS:
Oncostatin M (OSM) is an inflammatory cytokine which interacts with a heterodimeric receptor formed by gp130 and either OSMRß or LIFR. Here we have analysed OSM and its receptors in livers with chronic hepatitis C (CHC) and studied the factors that regulate this system.
METHODS:
OSM, OSM receptors and OSM-target molecules were studied by immunohistochemistry and/or qPCR analysis in livers from CHC patients and controls. We determined the production of OSM by CD40L-stimulated antigen presenting cells (APC) and its biological effects on HuH7 cells containing HCV replicon (HuH7 Core-3').
RESULTS:
OSM was upregulated in livers with CHC and its production was mapped to CD11c+ cells. OSM levels correlated directly with inflammatory activity and CD40L expression. In vitro studies showed that OSM is released by APC upon interaction with activated CD4+ T cells in a CD40L-dependent manner. Culture of HuH7 Core-3' cells with supernatant from CD40L-stimulated APC repressed HCV replication and induced IL-7 and IL-15R¿. These effects were dampened by antibodies blocking OSM or gp130 and by silencing OSMRß. In CHC livers OSMRß and LIFR were significantly downregulated and their values correlated with those of OSM-induced molecules. Experiments in HuH7 cells showed that impaired STAT3 signaling and exposure to TGFß1, two findings in CHC, are factors involved in repressing OSMRß and LIFR, respectively.
CONCLUSIONS:
OSM is a cytokine possessing vigorous antiviral and immunostimulatory properties which is released by APC upon interaction with CD40L present on activated CD4+ T cells. In livers with CHC, OSM is overexpressed but its biological activity appears to be hampered because of downregulation of its receptor subunits.
Revista:
GASTROENTEROLOGIA Y HEPATOLOGIA
ISSN 0210-5705
Vol. 37
N° 4
Año 2014
Págs.233-239
The FibroScan(®) XL probe has been specifically designed for obese patients to measure liver stiffness by transient elastography, but it has not been well tested in non-obese patients. The aim of this study was to compare the M and XL FibroScan(®) probes in a series of unselected obese (body mass index above 30 kg/m(2)) and non-obese patients with chronic liver disease. Two hundred and fifty-four patients underwent a transient elastography examination with both the M and XL probes. The results obtained with the two probes were compared in the whole series and in obese (n=82) and non-obese (n=167) patients separately. The reliability of the examinations was assessed using the criteria defined by Castéra et al. The proportion of reliable exams was significantly higher when the XL probe was used (83% versus 73%; P=.001). This significance was maintained in the group of obese patients (82% versus 55%; P<.001), but not in the non-obese patients (84% versus 83%). Despite a high correlation between the stiffness values obtained with the two probes (R=.897; P<.001), and a high concordance in the estimation of fibrosis obtained with the two probes (Cronbach's alpha value: 0.932), the liver stiffness values obtained with the XL probe were significantly lower than those obtained with the M probe, both in the whole series (9.5 ± 9.1 kPa versus 11.3 ± 12.6 kPa; P<0.001) and in the obese and non-obese groups. In conclusion, transient elastography with the XL probe allows a higher proportio
Revista:
GUT
ISSN 0017-5749
Vol. 63
N° 4
Año 2014
Págs.665 - 673
Background IL-7 and IL-15 are produced by hepatocytes and are critical for the expansion and function of CD8 T cells. IL-15 needs to be presented by IL-15R¿ for efficient stimulation of CD8 T cells.
Methods We analysed the hepatic levels of IL-7, IL-15, IL-15R¿ and interferon regulatory factors (IRF) in patients with chronic hepatitis C (CHC) (78% genotype 1) and the role of IRF1 and IRF2 on IL-7 and IL-15R¿ expression in Huh7 cells with or without hepatitis C virus (HCV) replicon.
Results Hepatic expression of both IL-7 and IL-15R¿, but not of IL-15, was reduced in CHC. These patients exhibited decreased hepatic IRF2 messenger RNA levels and diminished IRF2 staining in hepatocyte nuclei. We found that IRF2 controls basal expression of both IL-7 and IL-15R¿ in Huh7 cells. IRF2, but not IRF1, is downregulated in cells with HCV genotype 1b replicon and this was accompanied by decreased expression of IL-7 and IL-15R¿, a defect reversed by overexpressing IRF2. Treating Huh7 cells with IFN¿ plus oncostatin M increased IL-7 and IL-15R¿ mRNA more intensely than either cytokine alone. This effect was mediated by strong upregulation of IRF1 triggered by the combined treatment. Induction of IRF1, IL-7 and IL-15R¿ by IFN¿ plus oncostatin M was dampened in replicon cells but the combination was more effective than either cytokine alone.
Conclusions HCV genotype 1 infection downregulates IRF2 in hepatocytes attenuating hepatocellular expression of IL-7 and IL-15R¿. Our data reveal a new mechanism by which HCV abrogates specific T-cell responses and point to a novel therapeutic approach to stimulate anti-HCV immunity.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 60
N° 1
Año 2014
Págs.S40 - S40
Revista:
PLOS ONE
ISSN 1932-6203
Vol. 9
N° 5
Año 2014
Págs.e96799
Transforming growth factor ß (TGF-ß) is a powerful promoter of cancer progression and a key target for antitumor therapy. As cancer cells exhibit active cholesterol metabolism, high density lipoproteins (HDLs) appear as an attractive delivery system for anticancer TGFß-inhibitory molecules. We constructed a plasmid encoding a potent TGF-ß-blocking peptide (P144) linked to apolipoprotein A-I (ApoA-I) through a flexible linker (pApoLinkerP144). The ApoLinkerP144 sequence was then incorporated into a hepatotropic adeno-associated vector (AAVApoLinkerP144). The aim was to induce hepatocytes to produce HDLs containing a modified ApoA-I capable of blocking TGF-ß. We observed that transduction of the murine liver with pApoLinkerP144 led to the appearance of a fraction of circulating HDL containing the fusion protein. These HDLs were able to attenuate TGF-ß signaling in the liver and to enhance IL-12 -mediated IFN-¿ production. Treatment of liver metastasis of MC38 colorectal cancer with AAVApoLinkerP144 resulted in a significant reduction of tumor growth and enhanced expression of IFN-¿ and GM-CSF in cancerous tissue. ApoLinkerP144 also delayed MC38 liver metastasis in Rag2¿/¿IL2r¿¿/¿ immunodeficient mice. This effect was associated with downregulation of TGF-ß target genes essential for metastatic niche conditioning. Finally, in a subset of ret transgenic mice, a model of aggressive spontaneous metastatic melanoma, AAVApoLinkerP144 delayed tumor growth in association with increased CD8+ T cell numbers in regional lymph nodes. In conclusion, modification of HDLs to transport TGF-ß-blocking molecules is a novel and promising approach to inhibit the growth of liver metastases by immunological and non-immunological mechanisms.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 60
N° 1
Año 2014
Págs.S87 - S87
Revista:
HUMAN GENE THERAPY
ISSN 1043-0342
Vol. 25
N° 11
Año 2014
Págs.A45 - A46
Revista:
MOLECULAR THERAPY
ISSN 1525-0016
Vol. 22
N° Supl.1
Año 2014
Págs.S273 - S274
Revista:
HUMAN GENE THERAPY
ISSN 1043-0342
Vol. 25
N° 2
Año 2014
Págs.132 - 143
Interleukin-12 (IL-12) is an immunostimulatory cytokine that has shown strong antitumor effects in animal models of liver cancer. In order to overcome the severe toxicity associated with its systemic administration, we had previously tested different strategies based on IL-12 gene transfer to tumor cells or to the surrounding liver tissue. We obtained promising results both with a recombinant Semliki Forest virus (SFV) vector expressing high levels of IL-12 (SFV-IL-12) after intratumoral injection and with a plasmid vector [pTonL2(T)-mIL12] that allows liver-specific and inducible IL-12 expression. The aim of the present study was to compare the antitumor responses induced by both systems in a clinically relevant animal model of hepatocellular carcinoma (HCC) developed in L-PK/c-myc transgenic mice. These animals overexpress the c-myc oncogene in their livers, giving rise to spontaneous hepatic tumors with latency, histopathology, and genetic characteristics similar to human HCCs. We observed that intratumoral inoculation of SFV-IL-12 induced growth arrest in most tumors, providing 100% survival rate, in contrast to no survival in control animals. Similar results were obtained with hydrodynamic injection of pTonL2(T)-mIL12 after long-term induction of IL-12 expression in the liver. However, tumor arrest was less evident in plasmid-treated mice and the survival rate was slightly lower, despite higher and more sustained levels of IL-12 and IFN-¿ in serum. The fact that SFV-IL-12 was able to induce both apoptosis and a type-I IFN response specifically in the tumor could explain why short-term IL-12 expression from this vector was sufficient to mediate an antitumoral response comparable with long-term IL-12 expression driven by pTonL2(T)-mIL12. Since SFV-IL-12 could reduce the possible toxicity associated with long-term IL-12 expression, we believe that this vector could have a potential application for HCC gene therapy.
Revista:
JOURNAL OF CLINICAL INVESTIGATION
ISSN 0021-9738
Vol. 124
N° 7
Año 2014
Págs.2909-2920
A precise equilibrium between cellular differentiation and proliferation is fundamental for tissue homeostasis. Maintaining this balance is particularly important for the liver, a highly differentiated organ with systemic metabolic functions that is endowed with unparalleled regenerative potential. Carcinogenesis in the liver develops as the result of hepatocellular de-differentiation and uncontrolled proliferation. Here, we identified SLU7, which encodes a pre-mRNA splicing regulator that is inhibited in hepatocarcinoma, as a pivotal gene for hepatocellular homeostasis. SLU7 knockdown in human liver cells and mouse liver resulted in profound changes in pre-mRNA splicing and gene expression, leading to impaired glucose and lipid metabolism, refractoriness to key metabolic hormones, and reversion to a fetal-like gene expression pattern. Additionally, loss of SLU7 also increased hepatocellular proliferation and induced a switch to a tumor-like glycolytic phenotype. Slu7 governed the splicing and/or expression of multiple genes essential for hepatocellular differentiation, including serine/arginine-rich splicing factor 3 (Srsf3) and hepatocyte nuclear factor 4¿ (Hnf4¿), and was critical for cAMP-regulated gene transcription. Together, out data indicate that SLU7 is central regulator of hepatocyte identity and quiescence.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 59
N° 1
Año 2013
Págs.81-88
Background & Aims: Tremelimumab is a monoclonal antibody that blocks cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), an inhibitory co-receptor that interferes with T cell activation and proliferation. The purpose of this pilot clinical trial was to test the antitumor and antiviral effect of tremelimumab in patients with hepatocellular carcinoma (HCC) and chronic hepatitis C virus (HCV) infection; and to study the safety of its administration to cirrhotic patients.
Methods: Tremelimumab at a dose of 15 mg/kg IV every 90 days was administered until tumor progression or severe toxicity. Twenty patients were assessable for toxicity and viral response and 17 were assessable for tumor response. Most patients were in the advanced stage and 43% had an altered liver function (Child-Pugh class B).
Results: A good safety profile was recorded and no patient needed steroids because of severe immune-mediated adverse events. Some patients had a transient albeit intense elevation of transaminases after the first dose, but not following subsequent cycles. Partial response rate was 17.6% and disease control rate was 76.4%. Time to progression was 6.48 months (95% CI 3.95-9.14). A significant drop in viral load was observed while new emerging variants of the hypervariable region 1 of HCV replaced the predominant variants present before therapy, particularly in those patients with a more prominent drop in viral load. This antiviral effect was associated with an enhanced specific anti-HCV immune response.
Conclusions: Tremelimumab safety profile and antitumor and antiviral activity, in patients with advanced HCC developed on HCV-induced liver cirrhosis, support further investigation. (C) 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Revista:
BIOMED RESEARCH INTERNATIONAL
ISSN 2314-6133
Año 2013
Págs.864720
The development of tools for efficient targeting of antigens to antigen presenting cells is of great importance for vaccine development. We have previously shown that fusion proteins containing antigens fused to the extra domain A from fibronectin (EDA), an endogenous TLR4 ligand, which targets antigens to TLR4-expressing dendritic cells (DC), are highly immunogenic. To facilitate the procedure of joining EDA to any antigen of choice, we have prepared the fusion protein EDAvidin by linking EDA to the N terminus of streptavidin, allowing its conjugation with biotinylated antigens. We found that EDAvidin, as streptavidin, forms tetramers and binds biotin or biotinylated proteins with a Kd ~ 2.6 × 10(-14) mol/L. EDAvidin favours the uptake of biotinylated green fluorescent protein by DC. Moreover, EDAvidin retains the proinflammatory properties of EDA, inducing NF- ¿ß by TLR4-expressing cells, as well as the production of TNF- ¿ by the human monocyte cell line THP1 and IL-12 by DC. More importantly, immunization of mice with EDAvidin conjugated with the biotinylated nonstructural NS3 protein from hepatitis C virus induces a strong anti-NS3 T cell immune response. These results open a new way to use the EDA-based delivery tool to target any antigen of choice to DC for vaccination against infectious diseases and cancer.
Revista:
CANCER RESEARCH
ISSN 0008-5472
Vol. 73
N° 1
Año 2013
Págs.139-149
Interleukin (IL)-15 effects on CD8 T and natural killer (NK) lymphocytes hold promise to treat cancer. Fusion proteins have been engineered to provide IL-15 receptor alpha (IL-15R alpha) mediated trans-presentation to lymphocytes and extend the plasma half-life of the cytokine. In this study, we report on a triple fusion protein combining apolipoprotein A-I (Apo A-I), IL-15, and IL-15R alpha's sushi domain. Apo A-I conveys IL-15 to high-density lipoproteins (HDL), from which the cytokine is trans-presented by the IL-15R alpha's sushi domain. Such a construction was tested by hydrodynamic gene transfer to the liver of mice. Lethal toxicity was observed upon injection of 10 mu g of the expression plasmid. Mice died from an acute lymphocytic pneumonitis in which T and NK cells dominate a severe inflammatory infiltrate. Importantly, mice devoid of NK cells were not susceptible to such toxicity and mice lacking granzymes A and B also survived the otherwise lethal gene transfer. Lower plasmid doses (<2.5 mu g) were tolerated and dramatically increased the numbers of NK and memory CD8 T lymphocytes in the liver, spleen, and lungs, to the point of rescuing the deficiency of such lymphocyte subsets in IL-15R alpha(-/-) mice. Doses of plasmid within the therapeutic window successfully treated metastatic tumor models, including B16OVA lung metastasis of melanoma and MC38 colon cancer liver metastasis. Sushi-IL-15-Apo as a recombinant protein was also bioactive in vivo, became conjugated to HDL, and displayed immunotherapeutic effects against metastatic disease. Cancer Res; 73(1); 139-49. (C) 2012 AACR.
Revista:
EXPERT OPINION ON INVESTIGATIONAL DRUGS
ISSN 1354-3784
Vol. 22
N° 7
Año 2013
Págs.827 - 841
INTRODUCTION:
Cytokines are key mediators of the immune system and have been proposed as therapeutic agents against cancer, either as recombinant proteins, or as transgenes in gene therapy approaches. Stimulation of immune responses against cancer cells is an appealing method to treat tumors with high risk of relapse and systemic dissemination.
AREAS COVERED:
We provide a critical overview of clinical trials involving the use of cytokines for the treatment of liver, colon and pancreatic cancers. Special attention has been paid to advances in the field of gene therapy and oncolytic viruses. The potential of new developments still in a pre-clinical stage is also discussed. We have revised public sources of information (PubMed, US National Institutes of Health clinical trials database) up to January 2013.
EXPERT OPINION:
The complexity of the immune system and the unfavorable pharmacokinetic properties of cytokines limit the efficacy of these molecules as single agents for the treatment of cancer. Expression from gene therapy vectors, together with new methods of targeting and stabilization, may overcome these hurdles. We believe cytokines will play a crucial role as part of combined approaches, enhancing the action of adoptive cell immunotherapy, oncolytic viruses or biological therapies.
Revista:
OBESITY FACTS
ISSN 1662-4025
Vol. 6
N° Suppl. 1
Año 2013
Págs.71
Revista:
JOURNAL OF IMMUNOLOGY
ISSN 0022-1767
Vol. 190
N° 6
Año 2013
Págs.2994 - 3004
Semliki Forest virus vectors expressing IL-12 (SFV-IL-12) were shown to induce potent antitumor responses against s.c. MC38 colon adenocarcinomas in immunocompetent mice. However, when MC38 tumors were implanted in liver, where colon tumors usually metastasize, SFV-IL-12 efficacy was significantly reduced. We reasoned that characterization of immune responses against intrahepatic tumors in responder and nonresponder animals could provide useful information for designing more potent antitumor strategies. Remarkably, SFV-IL-12 induced a high percentage of circulating tumor-specific CD8 T cells in all treated animals. Depletion studies showed that these cells were essential for SFV-IL-12 antitumor activity. However, in comparison with nonresponders, tumor-specific cells from responder mice acquired an effector-like phenotype significantly earlier, were recruited more efficiently to the liver, and, importantly, persisted for a longer period of time. All treated mice had high levels of functional specific CD8 T cells at 8 d posttreatment reflected by both in vivo killing and IFN-¿-production assays, but responder animals showed a more avid and persistent IFN-¿ response. Interestingly, differences in immune responses between responders and nonresponders seemed to correlate with the immune status of the animals before treatment and were not due to the treatment itself. Mice that rejected tumors were protected against tumor rechallenge, indicating that sustained memory responses are required for an efficacious therapy. Interestingly, tumor-specific CD8 T cells of responder animals showed upregulation of IL-15R¿ expression compared with nonresponders. These results suggest that SFV-IL-12 therapy could benefit from the use of strategies that could either upregulate IL-15R¿ expression or activate this receptor.
Revista:
ONCOIMMUNOLOGY
ISSN 2162-402X
Vol. 2
N° 12
Año 2013
Págs.UNSP e27009
Peptide vaccines derived from CD8(+) T-cell epitopes have shown variable efficacy in cancer patients. Thus, some peptide vaccines are capable of activating CD8(+) T-cell responses, even in the absence of CD4(+) T-cell epitopes or dendritic cell (DC)-activating adjuvants. However, the mechanisms underlying the clinical activity of these potent peptides are poorly understood. Using CT26 and ovalbumin-expressing B16 murine allograft tumor models, we found that the antitumor effect of helper cell-independent CD8 T-cell peptide vaccines is inhibited by the blockade of CD40 ligand (CD40L) in vivo. Furthermore, in vitro stimulation with antigenic peptides of cells derived from immunized mice induced the expression of CD40L on the surface of CD8(+) T cells and fostered DC maturation, an effect that was partially inhibited by CD40L-blocking antibodies. Interestingly, CD40L blockade also inhibited CD8(+) T-cell responses, even in the presence of fully mature DCs, suggesting a role for CD40L not only in promoting DC maturation but also in mediating CD8(+) T-cell co-stimulation. Importantly, these potent peptides share features with bona fide CD4 epitopes, since they foster responses against less immunogenic CD8(+) T-cell epitopes in a CD40L-dependent manner. The analysis of peptides used for the vaccination of cancer patients in clinical trials showed that these peptides also induce the expression of CD40L on the surface of CD8(+) T cells. Taken together, these results suggest that CD40L expression induced by potent CD8(+) T-cell epitopes can activate antitumor CD8(+) T-cell responses, potentially amplifying the immunological responses to less immunogenic CD8(+) T-cell epitopes and bypassing the requirement for CD4(+) helper T cells in vaccination protocols.
Revista:
HUMAN MOLECULAR GENETICS
ISSN 0964-6906
Vol. 22
N° 14
Año 2013
Págs.2929-40
Acute intermittent porphyria (AIP) is a hepatic metabolic disease that results from haplo-insufficient activity of porphobilinogen deaminase (PBGD). The dominant clinical feature is acute intermittent attacks when hepatic heme synthesis is activated by endocrine or exogenous factors. Gene therapy vectors over-expressing PBGD protein in the liver offers potential as a cure for AIP. Here, we developed a helper-dependent adenovirus (HDA) encoding human PBGD (hPBGD) and assessed its therapeutic efficacy in a murine model of AIP. Intravenous or intrahepatic administration of HDA-hPBGD to AIP mice resulted in a sustained hepatic hPBGD expression in a dose-dependent manner. Intrahepatic administration conveyed full protection against induced porphyria attacks at a significantly lower viral dose than intravenous injection. Transgenic hPBGD accumulated only in the cytosol of hepatocytes as the endogenous protein. Characterization of PBGD-deficient mouse strains revealed that a strong PBGD deficiency causes the chronic disturbance of cytosolic and endoplasmic reticulum folding machineries. This disturbance was completely restored over time by the over-expression of hPBGD. HDA-hPBGD is a promising vector that protects against porphyria attacks and resolves the chronic folding stress associated with low levels of PBGD activity.
Revista:
JOURNAL OF PHYSIOLOGY AND BIOCHEMISTRY
ISSN 1138-7548
Vol. 69
N° 4
Año 2013
Págs.835 - 845
Hepatocyte transplantation is considered a promising therapy for patients with liver diseases. Induced pluripotent stem cells (iPSCs) are an unlimited source for the generation of functional hepatocytes. While several protocols that direct the differentiation of iPSCs into hepatocyte-like cells have already been reported, the liver engraftment potential of iPSC progeny obtained at each step of hepatic differentiation has not yet been thoroughly investigated. In this study, we present an efficient strategy to differentiate mouse iPSCs into hepatocyte-like cells and evaluate their liver engraftment potential at different time points of the protocol (5, 10, 15, and 20 days of differentiation). iPSCs were differentiated in the presence of cytokines, growth factors, and small molecules to finally generate hepatocyte-like cells. These iPSC-derived hepatocyte-like cells exhibited hepatocyte-associated functions, such as albumin secretion and urea synthesis. When we transplanted iPSC progeny into the spleen, we found that 15- and 20-day iPSC progeny engrafted into the livers and further acquired hepatocyte morphology. In contrast, 5- and 10-day iPSC progeny were also able to engraft but did not generate hepatocyte-like cells in vivo. Our data may aid in improving current protocols geared towards the use of iPSCs as a new source of liver-targeted cell therapies.
Revista:
PLOS ONE
ISSN 1932-6203
Vol. 8
N° 7
Año 2013
Págs.e67748
Recombinant adenoassociated viral vectors (rAAV) have proven to be excellent candidates for gene therapy clinical applications. Recent results showed that cellular immunity to AAV represents a major challenge facing the clinical use of systemic administration of these vectors. Interestingly, no preclinical animal model has previously fully reproduced the clinical findings. The aim of the present work was to enhance the T cell immune response against AAV capsid in mice by the administration of a rAAV expressing the immunostimulatory cytokine IL-12. Our results indicate that although IL-12 expression enhanced the AAV capsid-specific immune response it failed to eliminate transduced hepatocytes and long-term expression was achieved. We found that AAV-mediated transgene expression is altered by IL-12-induced liver inflammation. However, IL-12 expression has no effect over preexisting AAV-mediated transgene expression. IL-12 down-regulates AAV mediated transgene expression via induction of IFN-¿ production by NK and T cells, but without altering the transduction efficiency measured by viral genomes. Our results indicate that liver inflammation affects the formation of transcriptionally active AAV vector genomes through an unknown mechanism that can be avoided by the use of DNA-demethylating or anti-inflammatory agents.
Revista:
GUT
ISSN 0017-5749
Vol. 62
N° 6
Año 2013
Págs.899 - 910
Objective Cholestasis is associated with increased liver injury and morbidity after partial hepatectomy (PH), yet bile acids (BAs) are emerging as important mediators of liver regeneration. Fibroblast growth factor 15 (Fgf15, human FGF19) is a BA-induced ileum-derived enterokine that governs BA metabolism. We evaluated the relevance of Fgf15 in the preservation of BA homeostasis after PH and its potential role in the regenerative process.
Design Liver regeneration after PH was studied in Fgf15(-/-) and Fgf15(+/+) mice. The effects of the BA sequestrant cholestyramine and adenovirally delivered Fgf15 were examined in this model. The role of Fgf15 in BA-induced liver growth was tested in Fgf15-/- mice upon cholic acid (CA) feeding. The direct mitogenic effect of Fgf15 was evaluated in cultured mouse hepatocytes and cholangiocytes.
Results Fgf15(-/-) mice showed marked liver injury and mortality after PH accompanied by persistently elevated intrahepatic BA levels. Cholestyramine feeding and adenovirally delivered Fgf15 reduced BA levels and significantly prevented this lethal outcome. Fgf15 also reduced mortality after extensive hepatectomy in Fgf15(+/+) animals. Liver growth elicited by CA feeding was significantly diminished in Fgf15(-/-) mice. Proliferation of hepatocytes and cholangiocytes was also noticeably reduced in CA-fed Fgf15(-/-) mice. Fgf15 induced intracellular signalling and proliferation of cultured hepatocytes and cholangiocytes.
Conclusions Fgf15 is necessary to maintain BA homeostasis and prevent liver injury during liver regeneration. Moreover, Fgf15 is an essential mediator of the liver growth-promoting effects of BA. Preoperative administration of this enterokine to patients undergoing liver resection might be useful to reduce damage and foster regeneration.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 58
Año 2013
Págs.S126 - S126
Revista:
ACTA GASTRO-ENTEROLOGICA BELGICA
ISSN 1784-3227
Vol. 76
N° 2
Año 2013
Págs.246-50
Patients with heart failure have increased liver stiffness, that appears to be related with the severity of heart failure
Revista:
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS
ISSN 1388-1981
Vol. 1832
N° 6
Año 2013
Págs.697-704
Adamant progression of chronic cholangiopathies towards cirrhosis and limited therapeutic options leave a liver transplantation the only effective treatment. Insulin-like growth factor 1 (IGF1) effectively blocks fibrosis in acute models of liver damage in mice, and a phase I clinical trial suggested an improved liver function. IGF1 targets the biliary epithelium, but its potential benefit in chronic cholangiopathies has not been studied. To investigate the possible therapeutic effect of increased IGF1 expression, we crossed Abcb4¿/¿ mice (a model for chronic cholangiopathy), with transgenic animals that overexpress IGF1. The effect on disease progression was studied in the resulting IGF1-overexpressing Abcb4¿/¿ mice, and compared to that of Abcb4¿/¿ littermates. The specificity of this effect was further studied in an acute model of fibrosis. The overexpression of IGF1 in transgenic Abcb4¿/¿ mice resulted in stimulation of fibrogenic processes ¿ as shown by increased expression of Tgfß, and collagens 1, 3 and 4, and confirmed by Sirius red staining and hydroxyproline measurements. Excessive extracellular matrix deposition was favored by raise in Timp1 and Timp2, while a reduction of tPA expression indicated lower tissue remodeling. These effects were accompanied by an increase in expression of inflammation markers like Tnf¿, and higher presence of infiltrating macrophages. Finally, increased number of Ck19-expressing cells indicated proliferation of biliary epithelium. In contrast to liver fibrosis associated with hepatocellular damage, IGF1 overexpression does not inhibit liver fibrogenesis in chronic cholangiopathy.
Revista:
LIVER INTERNATIONAL
ISSN 1478-3223
Vol. 34
N° 7
Año 2013
Págs.e257 - e270
Background & Aims Upon tissue injury, the liver mounts a potent reparative and regenerative response. A role for proteases, including serine and matrix metalloproteinases ( MMPs), in this process is increasingly recognized. We have evaluated the expression and function of MMP10 (stromelysin-2) in liver wound healing and regeneration. Methods The hepatic expression of MMP10 was examined in two murine models: liver regeneration after two-thirds partial hepatectomy (PH) and bile duct ligation (BDL). MMP10 was detected in liver tissues by qPCR, western blotting and immunohistochemistry. The effect of growth factors and toll-like receptor 4 (TLR4) agonists on MMP10 expression was studied in cultured parenchymal and biliary epithelial cells and macrophages respectively. The role of MMP10 was evaluated by comparing the response of Mmp10+/+ and Mmp10¿/¿ mice to PH and BDL. The intrahepatic turnover of the extracellular matrix proteins fibrin (ogen) and fibronectin was examined. Results MMP10 mRNA was readily induced after PH and BDL. MMP10 protein was detected in hepatocytes, cholangiocytes and macrophages. In cultured liver epithelial cells, MMP10 expression was additively induced by transforming growth factor-ß and epidermal growth factor receptor ligands. TLR4 ligands also stimulated MMP10 expression in macrophages. Lack of MMP10 resulted in increased liver injury upon PH and BDL. Resolution of necrotic areas was impaired, and Mmp10¿/¿ mice showed increased fibrogenesis and defective turnover of fibrin (ogen) and fibronectin. Conclusions MMP10 expression is induced during mouse liver injury and participates in the hepatic wound healing response. The profibrinolytic activity of MMP10 may be essential in this novel hepatoprotective role.
Revista:
GASTROENTEROLOGY
ISSN 0016-5085
Vol. 144
N° 4
Año 2013
Págs.818 - 828
Background& Aims: ¿1-Antichymotrypsin (¿1-ACT), a member of the serpin family (SERPINA3), is an acute-phase protein secreted by hepatocytes in response to cytokines such as oncostatin M. ¿1-ACT is a protease inhibitor thought to limit tissue damage produced by excessive inflammation-associated proteolysis. However, ¿1-ACT also is detected in the nuclei of cells, where its activities are unknown. Expression of ¿1-ACT is down-regulated in human hepatocellular carcinoma (HCC) tissues and cells; we examined its roles in liver regeneration and HCC proliferation.
Methods: We measured levels of ¿1-ACT messenger RNA in human HCC samples and healthy liver tissue. We reduced levels of ¿1-ACT using targeted RNA interference in human HCC (HepG2) and mouse hepatocyte (AML12) cell lines, and overexpressed ¿1-ACT from lentiviral vectors in Huh7 (HCC) cells and adeno-associated viral vectors in livers of mice. We assessed proliferation, differentiation, and chromatin compaction in cultured cells, and liver regeneration and tumor formation in mice.
Results: Reducing levels of ¿1-ACT promoted proliferation of HCC cells in vitro. Oncostatin M up-regulated ¿1-ACT expression and nuclear translocation, which inhibited HCC cell proliferation and activated differentiation of mouse hepatocytes. We identified amino acids required for ¿1-ACT nuclear localization, and found that ¿1-ACT inhibits cell-cycle progression and anchorage-independent proliferation of HCC cells. HCC cells that overexpressed ¿1-ACT formed smaller tumors in mice than HCC cells that did not express the protein. ¿1-ACT was observed to self-associate and polymerize in the nuclei of cells; nuclear ¿1-ACT strongly bound chromatin to promote a condensed state that could prevent cell proliferation.
Conclusions: ¿1-ACT localizes to the nuclei of hepatic cells to control chromatin condensation and proliferation. Overexpression of ¿1-ACT slows the growth of HCC xenograft tumors in nude mice.
Revista:
Hepatology
ISSN 0270-9139
Vol. 57
N° 3
Año 2013
Págs.1078 - 1087
Radioembolization (RE)-induced liver disease (REILD) has been defined as jaundice and ascites appearing 1 to 2 months after RE in the absence of tumor progression or bile duct occlusion. Our aims were to study the incidence of REILD in a large cohort of patients and the impact of a series of changes introduced in the processes of treatment design, activity calculation, and the routine use of ursodeoxycholic acid and low-dose steroids (modified protocol). Between 2003 and 2011, 260 patients with liver tumors treated by RE were studied (standard protocol: 75, modified protocol: 185). REILD appeared only in patients with cirrhosis or in noncirrhosis patients exposed to systemic chemotherapy prior to RE. Globally, the incidence of REILD was reduced in the modified protocol group from 22.7% to 5.4% and the incidence of severe REILD from 13.3% to 2.2% (P < 0.0001). Treatment efficacy was not jeopardized since 3-month disease control rates were virtually identical in both groups (66.7% and 67.2%, P = 0.93). Exposure to chemotherapy in the 2-month period following RE and being treated by the standard protocol were independent predictors of REILD among noncirrhosis patients. In cirrhosis, the presence of a small liver (total volume <1.5 L), an abnormal bilirubin (>1.2 mg/dL), and treatment in a selective fashion were independently associated with REILD. Conclusion: REILD is an uncommon but relevant complication that appears when liver tissue primed by cirrhosis or prior and subsequent chemotherapy is exposed to the radiation delivered by radioactive microspheres. We designed a comprehensive treatment protocol that reduces the frequency and the severity of REILD. (HEPATOLOGY 2013)
Revista:
HUMAN GENE THERAPY
ISSN 1043-0342
Vol. 24
N° 12
Año 2013
Págs.1007 - 1017
Acute intermittent porphyria (AIP) results from haplo-insufficient activity of porphobilinogen deaminase (PBGD) and is characterized clinically by life-threatening, acute neurovisceral attacks. To date, liver transplantation is the only curative option for AIP. The aim of the present preclinical nonhuman primate study was to determine the safety and transduction efficacy of an adeno-associated viral vector encoding PBGD (recombinant AAV serotype 5-codon-optimized human porphobilinogen deaminase, rAAV5-cohPBGD) administered intravenously as part of a safety program to start a clinical study in patients with AIP. Macaques injected with either 1 × 10(13) or 5 × 10(13) vector genomes/kg of clinical-grade rAAV5-cohPBGD were monitored by standardized clinical parameters, and vector shedding was analyzed. Liver transduction efficacy, biodistribution, vector integration, and histopathology at day 30 postvector administration were determined. There was no evidence of acute toxicity, and no adverse effects were observed. The vector achieved efficient and homogenous hepatocellular transduction, reaching transgenic PBGD expression levels equivalent to 50% of the naturally expressed PBGD mRNA. No cellular immune response was detected against the human PBGD or AAV capsid proteins. Integration site analysis in transduced liver cells revealed an almost random integration pattern supporting the good safety profile of rAAV5-cohPBGD. Together, data obtained in nonhuman primates indicate that rAAV5-cohPBGD represents a safe therapy to correct the metabolic defect present in AIP patients.
Revista:
PLOS ONE
ISSN 1932-6203
Vol. 8
N° 9
Año 2013
Págs.e74948
It has been shown that the liver of immunodeficient mice can be efficiently repopulated with human hepatocytes when subjected to chronic hepatocellular damage. Mice with such chimeric livers represent useful reagents for medical and clinical studies. However all previously reported models of humanized livers are difficult to implement as they involve cross-breeding of immunodeficient mice with mice exhibiting genetic alterations causing sustained hepatic injury. In this paper we attempted to create chimeric livers by inducing persistent hepatocellular damage in immunodeficient Rag2(-/-) gamma c(-/-) mice using an adenovirus encoding herpes virus thymidine kinase (AdTk) and two consecutive doses of ganciclovir (GCV). We found that this treatment resulted in hepatocellular damage persisting for at least 10 weeks and enabled efficient engraftment and proliferation within the liver of either human or allogenic hepatocytes. Interestingly, while the nodules generated from the transplanted mouse hepatocytes were well vascularized, the human hepatocytes experienced progressive depolarization and exhibited reduced numbers of murine endothelial cells inside the nodules. In conclusion, AdTk/GCV-induced liver damage licenses the liver of immunodeficient mice for allogenic and xenogenic hepatocyte repopulation. This approach represents a simple alternative strategy for chimeric liver generation using immunodeficient mice without additional genetic manipulation of the germ line.
Revista:
PLOS ONE
ISSN 1932-6203
Vol. 8
N° 1
Año 2013
Págs.e52683
Zolmitriptan reduces portal hypertension and non-selective beta-blockers can improve this effect. Combination therapy deserves consideration for patients with portal hypertension failing to respond to non-selective beta-blockers.
Revista:
Gene therapy (Basingstoke) (print)
ISSN 0969-7128
Vol. 19
N° 3
Año 2012
Págs.271 - 278
Revista:
GENE THERAPY
ISSN 0969-7128
Vol. 19
N° 4
Año 2012
Págs.411 - 417
In liver cirrhosis, abnormal liver architecture impairs efficient transduction of hepatocytes with large viral vectors such as adenoviruses. Here we evaluated the ability of adeno-associated virus (AAV) vectors, small viral vectors, to transduce normal and cirrhotic rat livers. Using AAV serotype-1 (AAV1) encoding luciferase (AAV1Luc) we analyzed luciferase expression with a CCD camera. AAV1Luc was injected through the hepatic artery (intra-arterial (IA)), the portal vein (intra-portal (IP)), directly into the liver (intra-hepatic (IH)) or infused into the biliary tree (intra-biliar). We found that AAV1Luc allows long-term and constant luciferase expression in rat livers. Interestingly, IP administration leads to higher expression levels in healthy than in cirrhotic livers, whereas the opposite occurs when using IA injection. IH administration leads to similar transgene expression in cirrhotic and healthy rats, whereas intra-biliar infusion is the least effective route. After 70% partial hepatectomy, luciferase expression decreased in the regenerating liver, suggesting lack of efficient integration of AAV1 DNA into the host genome. AAV1Luc transduced mainly the liver but also the testes and spleen. Within the liver, transgene expression was found mainly in hepatocytes. Using a liver-specific promoter, transgene expression was detected in hepatocytes but not in other organs. Our results indicate that AAVs are convenient vectors for the treatment of liver cirrhosis.
Revista:
JOURNAL OF IMMUNOLOGY
ISSN 0022-1767
Vol. 189
N° 7
Año 2012
Págs. 3299 - 3310
Revista:
VACCINE
ISSN 0264-410X
Vol. 30
N° 18
Año 2012
Págs.2848 - 2858
The complement system and Toll-like receptors (TLR) are key innate defense systems which might interact synergistically on dendritic cells (DC) to reinforce adaptive immunity. In a previous work, we found that the extra domain A from fibronectin EDA (an endogenous ligand for TLR4) can favour antigen delivery to DC and induce their maturation. Given the potential of anaphylatoxins to cause inflammation and activation of myeloid cells, we hypothesized that a fusion protein between EDA, and anaphylatoxins C3a, C4a or C5a together with an antigen might improve the immunogenicity of the antigen. Naked DNA immunization with a construct expressing the fusion protein between C5a, EDA and the cytotoxic T cell epitope SIINFEKL from ovalbumin, induced strong antigen specific T cell responses. The purified recombinant fusion protein EDA¿SIINFEKL¿C5a induced activation of dendritic cells, the production of proinflammatory cytokines/chemokines and stimulated antigen presenting cell migration and NK cell activation. As compared to EDA¿SIINFEKL, the fusion protein EDA¿SIINFEKL¿C5a did not induce the production of the immunosuppressive molecules IL-10, CCL17, CCL1, CXCL12 or XCL1 by DC. Moreover, EDA¿SIINFEKL¿C5a induced strong specific T cell responses in vivo and protected mice against E.G7-OVA tumor growth more efficiently than EDA¿SIINFEKL or SIINFEKL¿C5a recombinant proteins. Our results suggest that fusion proteins containing EDA, the anaphylatoxin C5a and the antigen may serve as a suitable strategy for the development of anti-tumor or anti-viral vaccines.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 56
Año 2012
Págs.S29-S29
Revista:
DIGESTIVE DISEASES
ISSN 0257-2753
Vol. 30
N° 5
Año 2012
Págs.524-531
Background/Aims: Hepatocellular carcinoma (HCC) is a chemoresistant tumor strongly associated with chronic hepatitis. Identification of molecular links connecting inflammation with cell growth/survival, and characterization of pro-tumorigenic intracellular pathways is therefore of therapeutic interest. The epidermal growth factor receptor (EGFR) signaling system stands at a crossroad between inflammatory signals and intracellular pathways associated with hepatocarcinogenesis. We investigated the regulation and activity of different components of the EGFR system, including the EGFR ligand amphiregulin (AR) and its sheddase ADAM17, and the modulation of intracellular EGFR signaling by a novel mechanism involving protein methylation. Methods: ADAM17 protein expression was examined in models of liver injury and carcinogenesis. Crosstalk between tumor necrosis factor (TNF)-alpha, AR and EGFR signaling was evaluated in human HCC cells and mouse hepatocytes. Modulation of EGFR signaling and biological responses by methylation reactions was evaluated in AML12 mouse hepatocytes. Results: ADAM17 was upregulated in liver injury and hepatocarcinogenesis. TNF-alpha triggered AR shedding and EGFR transactivation in HCC cells. AR was necessary for TNF-alpha activation of ERK1/2 and Akt signaling in hepatocytes. Inhibition of methylation reactions increased the ERK1/2 signal amplitude triggered by AR/EGFR and reduced DNA synthesis in AML12 cells. Conclusions: Increased ADAM17 in preneoplastic liver injury further supports its implication in hepatocarcinogenesis. AR release and EGFR transactivation by TNF-alpha constitutes a novel link between inflammatory signals and pro-tumorigenic mechanisms in liver cells. Finally, the identification of a new mechanism controlling growth factor signaling, and biological responses, involving methylation reactions within the RAS/RAF/MEK/ERK pathway, exposes a new target for antineoplastic intervention. Copyright (C) 2012 S. Karger AG, Basel
Revista:
INTERNATIONAL JOURNAL OF CANCER
ISSN 0020-7136
Vol. 131
N° 3
Año 2012
Págs.641 - 651
Cervical carcinoma is one of the most common cancers in women worldwide. It is well established that chronic infection of the genital tract by various mucosatropic human papillomavirus (HPV) types causes cervical cancer. Cellular immunity to E7 protein from HPV (HPVE7) has been associated with clinical and cytologic resolution of HPV-induced lesions. Thus, we decided to test if targeting of HPVE7 to dendritic cells using a fusion protein containing the extra domain A (EDA) from fibronectin, a natural ligand for TLR4, and HPVE7 (EDA-HPVE7) might be an efficient vaccine for the treatment of cervical carcinoma. We found that EDA-HPVE7 fusion protein was efficiently captured by bone marrow derived dendritic cells in vitro and induced their maturation, with the upregulation of maturation markers and the production of IL-12. Immunization of mice with EDA-HPVE7 fusion protein induced antitumor CD8+ T cell responses in the absence of additional adjuvants. Repeated intratumoral administration of EDA-HPVE7 in saline was able to cure established TC-1 tumors of 57 mm in diameter. More importantly, intravenous injection with EDA-HPVE7 in combination with the TLR ligand polyinosinic-polycytidylic acid (pIC), or with low doses of cyclophosphamide and the TLR9 ligand CpG-B complexed in cationic lipids, were able to eradicate large established TC-1 tumors (1.2 cm in diameter). Thus, therapeutic vaccination with EDA-HPVE7 fusion protein may be effective in the treatment of human cervical carcinoma.
Revista:
HUMAN GENE THERAPY
ISSN 1043-0342
Vol. 23
N° 12
Año 2012
Págs.1258-1268
Replication-competent (oncolytic) adenoviruses (OAV) can be adapted as vectors for the delivery of therapeutic genes, with the aim of extending the antitumor effect beyond direct cytolysis. Transgene expression using these vectors is usually intense but short-lived, and repeated administrations are hampered by the rapid appearance of neutralizing antibodies (NAbs). We have studied the performance of monocytes as cell carriers to improve transgene expression in cancer models established in athymic mice and immunocompetent Syrian hamsters. Human and hamster monocytic cell lines (MonoMac6 and HM-1, respectively) were loaded with replication-competent adenovirus-expressing luciferase. Intravenous administration of these cells caused a modest increase in transgene expression in tumor xenografts, but this effect was virtually lost in hamsters. In contrast, intratumoral administration of HM-1 cells allowed repeated cycles of expression and achieved partial protection from NAbs in preimmunized hamsters bearing pancreatic tumors. To explore the therapeutic potential of this approach, HM-1 cells were loaded with a hypoxia-inducible OAV expressing the immunostimulatory cytokine interleukin-12 (IL-12). Three cycles of treatment achieved a significant antitumor effect in the hamster model, and transgene expression was detected following each administration, in contrast with the rapid neutralization of the free virus. We propose monocytes as carriers for multiple intratumoral administrations of armed OAVs.
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 56
N° Supl. 1
Año 2012
Págs.239A
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 56
N° 2
Año 2012
Págs.367 - 373
Background & Aims Bile acids (BA) are increasingly recognized as important modulators of liver regeneration. Increased enterohepatic BA flux has been proposed to generate specific signals that activate hepatocyte proliferation after partial hepatectomy (PH). We have investigated the role of the BA membrane transporter Mrp3 (Abcc3), which is expressed in the liver and gut, in the hepatic growth response elicited by BA and in liver regeneration after PH.
Methods Liver growth and regeneration, and the expression of growth-related genes, were studied in Mrp3+/+ and Mrp3¿/¿ mice fed a cholic acid (CA) supplemented diet and after 2/3 PH. Activation of the BA receptor FXR was measured in mice after in vivo transduction of the liver with a FXR-Luciferase reporter plasmid. BA levels were measured in portal serum and liver tissue by high performance liquid chromatography-tandem mass spectrometry.
Results Liver growth elicited by CA feeding was significantly reduced in Mrp3¿/¿ mice. These animals showed reduced FXR activation in the liver after CA administration and decreased portal serum levels of BA. Liver regeneration after PH was significantly delayed in Mrp3-deficient mice. Proliferation-related gene expression and peak DNA synthesis in Mrp3¿/¿ mice occurred later than in wild types, coinciding with a retarded elevation in intra-hepatic BA levels.
Conclusions Lack of Abcc3 expression markedly impairs liver growth in response to BA and after PH. Our data suggest that Mrp3 plays a non-redundant role in the regulation of BA flux during liver regeneration.
Revista:
PLOS ONE
ISSN 1932-6203
Vol. 7
N° 12
Año 2012
Apolipoprotein A-I (Apo A-I) is a major component of high density lipoproteins (HDL) that transport cholesterol in circulation. We have constructed an expression plasmid encoding a chimeric molecule encompassing interleukin-15 (IL-15) and Apo A-I (pApo-hIL15) that was tested by hydrodynamic injections into mice and was co-administered with a plasmid encoding the sushi domain of IL-15R alpha (pSushi) in order to enhance IL-15 trans-presentation and thereby bioactivity. The pharmacokinetics of the Apo A-I chimeric protein were much longer than non-stabilized IL-15 and its bioactivity was enhanced in combination with IL-15R alpha Sushi. Importantly, the APO-IL-15 fusion protein was incorporated in part into circulating HDL. Liver gene transfer of these constructs increased NK and memory-phenotype CD8 lymphocyte numbers in peripheral blood, spleen and liver as a result of proliferation documented by CFSE dilution and BrdU incorporation. Moreover, the gene transfer procedure partly rescued the NK and memory T-cell deficiency observed in IL-15R alpha(-/-) mice. pApo-hIL15+ pSushi gene transfer to the liver showed a modest therapeutic activity against subcutaneously transplanted MC38 colon carcinoma tumors, that was more evident when tumors were set up as liver metastases. The improved pharmacokinetic profile and the strong biological activity of APO-IL-15 fusion protein holds promise for further development in combination with other immunotherapies.
Revista:
Hepatology
ISSN 0270-9139
Vol. 56
N° 2
Año 2012
Págs.474 - 483
Revista:
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN 0027-8424
Vol. 109
N° 31
Año 2012
Págs.12449 - 12454
Protein N-terminal acetylation (Nt-acetylation) is an important mediator of protein function, stability, sorting, and localization. Although the responsible enzymes are thought to be fairly well characterized, the lack of identified in vivo substrates, the occurrence of Nt-acetylation substrates displaying yet uncharacterized N-terminal acetyltransferase (NAT) specificities, and emerging evidence of posttranslational Nt-acetylation, necessitate the use of genetic models and quantitative proteomics. NatB, which targets Met-Glu-, Met-Asp-, and Met-Asn-starting protein N termini, is presumed to Nt-acetylate 15% of all yeast and 18% of all human proteins. We here report on the evolutionary traits of NatB from yeast to human and demonstrate that ectopically expressed hNatB in a yNatB-Delta yeast strain partially complements the natB-Delta phenotypes and partially restores the yNatB Nt-acetylome. Overall, combining quantitative N-terminomics with yeast studies and knockdown of hNatB in human cell lines, led to the unambiguous identification of 180 human and 110 yeast NatB substrates. Interestingly, these substrates included Met-Gln- N-termini, which are thus now classified as in vivo NatB substrates. We also demonstrate the requirement of hNatB activity for maintaining the structure and function of actomyosin fibers and for proper cellular migration. In addition, expression of tropomyosin-1 restored the altered focal adhesions and cellular migration defects observed in hNatB-depleted HeLa cells, indicative for the conserved link between NatB, tropomyosin, and actin cable function from yeast to human.
Revista:
VACCINE
ISSN 0264-410X
Vol. 12
N° 10
Año 2012
Págs.867 - 871
This work shows that class II-linked humoral lack of response to an antigen can be overcome by joint immunization with the antigen and a T-helper cell determinant (TDh) well recognized by class II molecules of a non-responder individual. Thus, SJL/J mice (H-2s), which are non-responders to the S region of hepatitis B virus surface antigen (HBsAg), were rendered responders by joint immunization with a recombinant surface antigen, only composed of the S region, and a short synthetic TDh peptide well recognized by the H-2s restriction. By contrast, when this peptide is not recognized as TDh, as in B10M mice (H-2f restricted and also non-responders to the S region), no humoral response could be induced against the S region. These results have important implications for therapy and vaccination against hepatitis B virus as well as in enhancing the immunogenicity of other antigens.
Revista:
JOURNAL OF PROTEOMICS
ISSN 1874-3919
Vol. 75
N° 18
Año 2012
Págs.5783 - 5792
Liver diseases are the fifth cause of mortality in Western countries, and as opposed to other major causes of mortality, their incidence is increasing. Understanding the molecular background contributing to the progression of liver ailments will surely open new perspectives for the better management of patients. The aim of this study is to elucidate mechanisms underlying the progression of liver injury associated with deficient prohibitin 1, an essential protein to maintain mitochondrial homeostasis and gene expression. PHB1 +/¿ mice developed a more severe steatohepatitis than WT littermates when exposed to a choline and methionine deficient diet. The increased sensitivity was mediated by mitochondrial dysfunction and metabolic impairment in PHB1 +/¿ livers, including inactivation of AMP kinase, measured under a non-restricted diet. Moreover, pro-inflammatory challenges induced higher mortality and liver injury in PHB +/¿ mice. The increased proliferative capacity of PHB +/¿ splenocytes, resulting from constitutive defects in central molecular pathways as stated by deregulation of GSK3ß, Erk, Akt or SHP-1, and the concomitant overproduction of pro-inflammatory mediators in Phb1 deficient mice, might account for these effects. In light of these results it might be concluded that Phb1 deficiency is a potential driver of chronic liver diseases by inducing hepatocyte damage and inflammation.
Revista:
JOURNAL OF PROTEOMICS
ISSN 1874-3919
Vol. 75
N° 10
Año 2012
Págs.2855 - 2868
Methionine adenosyltransferase I/III (MATI/III) synthesizes S-adenosylmethionine (SAM) in quiescent hepatocytes. Its activity is compromised in most liver diseases including liver cancer. Since SAM is a driver of hepatocytes fate we have studied the effect of re-expressing MAT1A in hepatoma Huh7 cells using proteomics. MAT1A expression leads to SAM levels close to those found in quiescent hepatocytes and induced apoptosis. Normalization of intracellular SAM induced alteration of 128 proteins identified by 2D-DIGE and gel-free methods, accounting for deregulation of central cellular functions including apoptosis, cell proliferation and survival. Human Dead-box protein 3 (DDX3X), a RNA helicase regulating RNA splicing, export, transcription and translation was down-regulated upon MAT1A expression. Our data support the regulation of DDX3X levels by SAM in a concentration and time dependent manner. Consistently, DDX3X arises as a primary target of SAM and a principal intermediate of its antitumoral effect. Based on the parallelism between SAM and DDX3X along the progression of liver disorders, and the results reported here, it is tempting to suggest that reduced SAM in the liver may lead to DDX3X up-regulation contributing to the pathogenic process and that replenishment of SAM might prove to have beneficial effects, at least in part by reducing DDX3X levels. This article is part of a Special Issue entitled: Proteomics: The clinical link.
Revista:
PLOS ONE
ISSN 1932-6203
Vol. 7
N° 12
Año 2012
Págs.e52711
Hepatocellular carcinoma (HCC) is the most prevalent liver tumor and a deadly disease with limited therapeutic options. Dysregulation of cell signaling pathways is a common denominator in tumorigenesis, including hepatocarcinogenesis. The epidermal growth factor receptor (EGFR) signaling system is commonly activated in HCC, and is currently being evaluated as a therapeutic target in combination therapies. We and others have identified a central role for the EGFR ligand amphiregulin (AR) in the proliferation, survival and drug resistance of HCC cells. AR expression is frequently up-regulated in HCC tissues and cells through mechanisms not completely known. Here we identify the ß-catenin signaling pathway as a novel mechanism leading to transcriptional activation of the AR gene in human HCC cells. Activation of ß-catenin signaling, or expression of the T41A ß-catenin active mutant, led to the induction of AR expression involving three specific ß-catenin-Tcf responsive elements in its proximal promoter. We demonstrate that HCC cells expressing the T41A ß-catenin active mutant show enhanced proliferation that is dependent in part on AR expression and EGFR signaling. We also demonstrate here a novel cross-talk of the EGFR system with fibroblast growth factor 19 (FGF19). FGF19 is a recently identified driver gene in hepatocarcinogenesis and an activator of ß-catenin signaling in HCC and colon cancer cells. We show that FGF19 induced AR gene expression through the ß-catenin pathway in human HCC cells. Importantly, AR up-regulation and EGFR signaling participated in the induction of cyclin D1 and cell proliferation elicited by FGF19. Finally, we demonstrate a positive correlation between FGF19 and AR expression in human HCC tissues, therefore supporting in clinical samples our experimental observations. These findings identify the AR/EGFR system as a key mediator of FGF19 responses in HCC cells involving ß-catenin signaling, and suggest that combined targeting of FGF19 and AR/EGFR may enhance therapeutic efficacy.
Revista:
PLoS One
ISSN 1932-6203
Vol. 7
N° 3
Año 2012
Págs.e32978
Chronic kidney disease is a long-term complication in acute intermittent porphyria (AIP). The pathophysiological significance of hepatic overproduction of the porphyrin precursors aminolevulinate acid (ALA) and porphobilinogen (PBG) in chronic kidney disease is unclear. We have investigated the effect of repetitive acute attacks on renal function and the effect of total or five-sixth nephrectomy causing renal insufficiency on hepatic heme synthesis in the porphobilinogen deaminase (PBGD)-deficient (AIP) mouse. Phenobarbital challenge in the AIP-mice increased urinary porphyrin precursor excretion. Successive attacks throughout 14 weeks led to minor renal lesions with no impact on renal function. In the liver of wild type and AIP mice, 5/6 nephrectomy enhanced transcription of the first and rate-limiting ALA synthase. As a consequence, urinary PBG excretion increased in AIP mice. The PBG/ALA ratio increased from 1 in sham operated AIP animals to over 5 (males) and over 13 (females) in the 5/6 nephrectomized mice. Total nephrectomy caused a rapid decrease in PBGD activity without changes in enzyme protein level in the AIP mice but not in the wild type animals. In conclusion, high concentration of porphyrin precursors had little impact on renal function. However, progressive renal insufficiency aggravates porphyria attacks and increases the PBG/ALA ratio, which should be considered a warning sign for potentially life-threatening impairment in AIP patients with signs of renal failure.
Revista:
ADIPOCYTE
ISSN 2162-3945
Vol. 1
N° 2
Año 2012
Págs.112 - 115
Cardiotrophin-1 (CT-1) is a member of the gp130 family of cytokines. In a recent study we examined the metabolic features of ct-1 null mice and the effects on body composition, glucose and lipid metabolism of acute and chronic administration of recombinant CT-1. Our data revealed that CT-1 is a key regulator of energy metabolism with potential applications in the treatment of obesity and the metabolic syndrome. This commentary discusses the significance of these findings in the context of other key studies in the field of obesity and insulin resistance.
Revista:
JOURNAL OF IMMUNOLOGY
ISSN 0022-1767
Vol. 188
N° 8
Año 2012
Págs.3988 - 3992
IFN-alfa is widely used for the treatment of chronic viral hepatitis and malignancies. However, systemic IFN-¿ treatment causes severe neuropsychiatric complications in humans, including depression, anxiety, and cognitive impairments. We have previously reported that the fusion protein formed by IFN-¿ and apolipoprotein A-I (IA) circulates bound to high-density lipoproteins (HDLs) and exhibits liver targeting, increased half-life, enhanced immunostimulatory activity, and reduced cytotoxicity. As the transport of HDLs across the blood-brain barrier is a highly complex and regulated process, in this study, we examine the effects of IA on the brain. Determination of IFN-¿ in brain and serum after hydrodynamic administration of different doses of a plasmid encoding IFN-¿ or IA showed that IA penetrated into the brain by a saturable transport mechanism. Thus, at high serum levels of the transgenes, the induction of IFN-sensitive genes and the number of phospho-STAT1(+) cell nuclei in the brain were substantially higher with IFN-¿ than with IA. This was associated with attenuation of neurodepression in mice given IA, as manifested by shorter immobility time in the tail suspension test. However, when given low doses of rIFN-¿ or the same antiviral units of HDLs containing IA, the induction of IFN-stimulated genes in the brain was significantly greater with the latter. In conclusion, IA crosses the blood-brain barrier not by diffusion, as is the case of IFN-¿, but by a facilitated saturable transport mechanism. Thus, linkage to apolipoprotein A-I may serve to modulate the effects of IFN-¿ on the CNS.
Revista:
Journal of Translational Medicine
ISSN 1479-5876
Vol. 10
Año 2012
Págs. 222
These results indicate that our transient and intensive pharmacological immunosuppression fails to improve AAV5-based liver gene transfer in non-human primates. The reasons include an incomplete restraint of humoral immune responses to viral capsids that interfere with repeated gene transfer in addition to an intriguing MMF-dependent drug-mediated interference with liver transgene expression.
Revista:
Hepatology
ISSN 0270-9139
Vol. 56
N° 2
Año 2012
Págs.687 - 697
Cl-/HCO?3- anion exchanger 2 (AE2) participates in intracellular pH homeostasis and secretin-stimulated biliary bicarbonate secretion. AE2/SLC4A2 gene expression is reduced in liver and blood mononuclear cells from patients with primary biliary cirrhosis (PBC). Our previous findings of hepatic and immunological features mimicking PBC in Ae2-deficient mice strongly suggest that decreased AE2 expression might be involved in the pathogenesis of PBC. Here, we tested the potential role of microRNA 506 (miR-506) predicted as candidate to target AE2 mRNA for the decreased expression of AE2 in PBC. Real-time quantitative polymerase chain reaction showed that miR-506 expression is increased in PBC livers versus normal liver specimens. In situ hybridization in liver sections confirmed that miR-506 is up-regulated in the intrahepatic bile ducts of PBC livers, compared with normal and primary sclerosing cholangitis livers. Precursor-mediated overexpression of miR-506 in SV40-immortalized normal human cholangiocytes (H69 cells) led to decreased AE2 protein expression and activity, as indicated by immunoblotting and microfluorimetry, respectively. Moreover, miR-506 overexpression in three-dimensional (3D)-cultured H69 cholangiocytes blocked the secretin-stimulated expansion of cystic structures developed under the 3D conditions. Luciferase assays and site-directed mutagenesis demonstrated that miR-506 specifically may bind the 3'untranslated region (3'UTR) of AE2 messenger RNA (mRNA) and prevent protein translation. Finally, cultured PBC cholangiocytes showed decreased AE2 activity, together with miR-506 overexpression, compared to normal human cholangiocytes, and transfection of PBC cholangiocytes with anti-miR-506 was able to improve their AE2 activity. Conclusion: miR-506 is up-regulated in cholangiocytes from PBC patients, binds the 3'UTR region of AE2 mRNA, and prevents protein translation, leading to diminished AE2 activity and impaired biliary secretory functions. In view of the putative pathogenic role of decreased AE2 in PBC, miR-506 may constitute a potential therapeutic target for this disease.
Revista:
Functional & Integrative Genomics
ISSN 1438-793X
Vol. 11
N° 3
Año 2011
Págs.419 - 429
Revista:
Human Gene Therapy (Print)
ISSN 1043-0342
Vol. 22
N° 8
Año 2011
Págs. 999-1009
Revista:
CANCER RESEARCH
ISSN 0008-5472
Vol. 71
N° 9
Año 2011
Págs.3214 - 3224
Revista:
Hepatology
ISSN 0270-9139
Vol. 53
N° 6
Año 2011
Págs.1864 - 1873
Interferon alpha (IFN alpha) is widely used for the treatment of viral hepatitis but substantial toxicity hampers its clinical use. In this work, we aimed at improving the efficacy of IFN alpha therapy by increasing the IFN alpha half-life and providing l
Revista:
CELL METABOLISM
ISSN 1550-4131
Vol. 14
N° 2
Año 2011
Págs.242 - 253
Cardiotrophin-1 (CT-1) is a member of the gp130 family of cytokines. We observed that ct-1¿/¿ mice develop mature-onset obesity, insulin resistance, and hypercholesterolemia despite reduced calorie intake. Decreased energy expenditure preceded and accompanied the development of obesity. Acute treatment with rCT-1 decreased blood glucose in an insulin-independent manner and increased insulin-stimulated AKT phosphorylation in muscle. These changes were associated with stimulation of fatty acid oxidation, an effect that was absent in AMPK¿2¿/¿ mice. Chronic rCT-1 treatment reduced food intake, enhanced energy expenditure, and induced white adipose tissue remodeling characterized by upregulation of genes implicated in the control of lipolysis, fatty acid oxidation, and mitochondrial biogenesis and genes typifying brown fat phenotype. Moreover, rCT-1 reduced body weight and corrected insulin resistance in ob/ob and in high-fat-fed obese mice. We conclude that CT-1 is a master regulator of fat and glucose metabolism with potential applications for treatment of obesity and insulin resistance.
Autores:
Tuñón, MJ; San Miguel, B; Crespo, I; et al.
Revista:
JOURNAL OF VIROLOGY
ISSN 0022-538X
Vol. 85
N° 24
Año 2011
Págs.13124 - 13132
Rabbit hemorrhagic disease virus (RHDV) causes lethal fulminant hepatitis closely resembling acute liver failure (ALF) in humans. In this study, we investigated whether cardiotrophin-1 (CT-1), a cytokine with hepatoprotective properties, could attenuate liver damage and prolong survival in virus-induced ALF. Twenty-four rabbits were infected with 2 x 10(4) hemagglutination units of RHDV. Twelve received five doses of CT-1 (100 mu g/kg) starting at 12 h postinfection (hpi) (the first three doses every 6 h and then two additional doses at 48 and 72 hpi), while the rest received saline. The animals were analyzed for survival, serum biochemistry, and viral load. Another cohort (n = 22) was infected and treated similarly, but animals were sacrificed at 30 and 36 hpi to analyze liver histology, viral load, and the expression of factors implicated in liver damage and repair. All infected rabbits that received saline died by 60 hpi, while 67% of the CT-1-treated animals survived until the end of the study. Treated animals showed improved liver function and histology, while the viral loads were similar. In the livers of CT-1-treated rabbits we observed reduction of oxidative stress, diminished PARP1/2 and JNK activation, and decreased inflammatory reaction, as reflected by reduced expression of tumor necrosis factor alpha, interleukin-1 beta, Toll-like receptor 4, VCAM-1, and MMP-9. In addition, CT-1-treated rabbits exhibited marked upregulation of TIMP-1 and increased expression of cytoprotective and proregenerative growth factors, including platelet-derived growth factor B, epidermal growth factor, platelet-derived growth factor receptor beta, and c-Met. In conclusion, in a lethal form of acute viral hepatitis, CT-1 increases animal survival by attenuating inflammation and activating cytoprotective mechanisms, thus representing a promising therapy for ALF of viral origin.
Revista:
AGING-US
ISSN 1945-4589
Vol. 3
N° 8
Año 2011
Págs.698 - 699
Revista:
JOURNAL OF MEDICAL VIROLOGY
ISSN 0146-6615
Vol. 83
N° 7
Año 2011
Págs.1221 - 1229
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 54
N° Supl. 1
Año 2011
Págs.778A
The identification of molecular mechanisms involved in the maintenance of the transformed phenotype of hepatocellular carcinoma (HCC) cells is essential for the elucidation of therapeutic strategies. Here, we show that human HCC cells display an autocrine loop mediated by connective tissue growth factor (CTGF) that promotes DNA synthesis and cell survival. Expression of CTGF was stimulated by epidermal growth factor receptor (EGFR) ligands and was dependent on the expression of the transcriptional coactivator, Yes-associated protein (YAP). We identified elements in the CTGF gene proximal promoter that bound YAP-enclosing complexes and were responsible for basal and EGFR-stimulated CTGF expression. We also demonstrate that YAP expression can be up-regulated through EGFR activation not only in HCC cells, but also in primary human hepatocytes. CTGF contributed to HCC cell dedifferentiation, expression of inflammation-related genes involved in carcinogenesis, resistance toward doxorubicin, and in vivo HCC cell growth. Importantly, CTGF down-regulated tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor 2 expression and was involved in the reduced sensitivity of these cells toward TRAIL-mediated apoptosis.
CONCLUSION:
We have identified autocrine CTGF as a novel determinant of HCC cells' neoplastic behavior. Expression of CTGF can be stimulated through the EGFR-signaling system in HCC cells in a novel cross-talk with the oncoprotein YAP. Moreover, to our knowledge, this is the first study that identifies a signaling mechanism triggering YAP gene expression in healthy and transformed liver parenchymal cells.
Revista:
Hepatology
ISSN 0270-9139
Vol. 54
N° 6
Año 2011
Págs.2149 - 2158
The identification of molecular mechanisms involved in the maintenance of the transformed phenotype of hepatocellular carcinoma (HCC) cells is essential for the elucidation of therapeutic strategies. Here, we show that human HCC cells display an autocrine
Revista:
Molecular Therapy
ISSN 1525-0016
Vol. 19
N° 7
Año 2011
Págs.1245 - 1253
Recombinant adeno-associated virus (rAAV) are effective gene delivery vehicles that can mediate long-lasting transgene expression. However, tight regulation and tissue-specific transgene expression is required for certain therapeutic applications.
Revista:
Annals of Nutrition and Metabolism
ISSN 0250-6807
Vol. 58
N° Supl. 3
Año 2011
Págs.262 - 263
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 1
N° 54
Año 2011
Págs.28 - 37
Revista:
CANCERS
ISSN 2072-6694
Vol. 3
N° 2
Año 2011
Págs.2444 - 2461
Hepatocarcinogenesis is a complex multistep process in which many different molecular pathways have been implicated. Hepatocellular carcinoma (HCC) is refractory to conventional chemotherapeutic agents, and the new targeted therapies are meeting with limited success. Interreceptor crosstalk and the positive feedback between different signaling systems are emerging as mechanisms of targeted therapy resistance. The identification of such interactions is therefore of particular relevance to improve therapeutic efficacy. Among the different signaling pathways activated in hepatocarcinogenesis the epidermal growth factor receptor (EGFR) system plays a prominent role, being recognized as a ¿signaling hub¿ where different extracellular growth and survival signals converge. EGFR can be transactivated in response to multiple heterologous ligands through the physical interaction with multiple receptors, the activity of intracellular kinases or the shedding of EGFR-ligands. In this article we review the crosstalk between the EGFR and other signaling pathways that could be relevant to liver cancer development and treatment.
Revista:
CLINICS AND RESEARCH IN HEPATOLOGY AND GASTROENTEROLOGY
ISSN 2210-7401
Vol. 35
N° 11
Año 2011
Págs.699 - 708
Liver diseases including inherited metabolic disorders, chronic viral hepatitis, liver cirrhosis and primary and metastatic liver cancer constitute a formidable health problem because of their high prevalence and the important limitations of current therapies. Gene therapy, a procedure based on the transfer of therapeutic genes to tissues, has been used since the 1990s as a new approach to treating a number of incurable conditions. After a period of lights and shades recent success in treating several devastating diseases like inherited immune deficiency disorders, beta-thalassemia, or inherited blindness appear to herald a new era where gene therapy can be listed among standard therapy options for a wide variety of human conditions. In this review, we provide information illustrating the potentiality of gene therapy in the management of liver diseases lacking other effective therapies.
Revista:
Molecular and Cellular Proteomics
ISSN 1535-9476
Vol. 10
N° 6
Año 2011
Págs. -
Herpesvirus type 1 (HSV-1) based oncolytic vectors arise as a promising therapeutic alternative for neoplastic diseases including hepatocellular carcinoma. However, the mechanisms mediating the host cell response to such treatments are not completely known. It is well established that HSV-1 infection induces functional and structural alterations in the nucleus of the host cell. In the present work, we have used gel-based and shotgun proteomic strategies to elucidate the signaling pathways impaired in the nucleus of human hepatoma cells (Huh7) upon HSV-1 Cgal+ infection. Both approaches allowed the identification of differential proteins suggesting impairment of cell functions involved in many aspects of host-virus interaction such as transcription regulation, mRNA processing, and mRNA splicing. Based on our proteomic data and additional functional studies, cellular protein quaking content (QKI) increases 4 hours postinfection (hpi), when viral immediate-early genes such as ICP4 and ICP27 could be also detected. Depletion of QKI expression by small interfering RNA results in reduction of viral immediate-early protein levels, subsequent decrease in early and late viral protein content, and a reduction in the viral yield indicating that QKI directly interferes with viral replication. In particular, HSV-1 Cgal+ induces a transient increase in quaking I-5 isoform (QKI-5) levels, in parallel with an enhancement of p27Kip1 protein content. Moreover, immunofluorescence microscopy showed an early nuclear redistribution of QKI-5, shuttling from the nucleus to the cytosol and colocalizing with nectin-1 in cell to cell contact regions at 16¿24 hpi. This evidence sheds new light on mechanisms mediating hepatoma cell response to HSV-1 vectors highlighting QKI as a central molecular mediator.
Revista:
JOURNAL OF HEPATOLOGY
ISSN 0168-8278
Vol. 54
N° 3
Año 2011
Págs.422 - 431
Revista:
HEPATOLOGY
ISSN 0270-9139
Vol. 53
N° 1
Año 2011
Págs.23 - 31
Revista:
GUT
ISSN 0017-5749
Vol. 60
N° 3
Año 2011
Págs.341-349
Revista:
ANNALS OF SURGICAL ONCOLOGY
ISSN 1068-9265
Vol. 18
N° 7
Año 2011
Págs.1964 - 1971
Revista:
GENE THERAPY
ISSN 0969-7128
Vol. 18
N° 11
Año 2011
Págs.1025-1033
Revista:
JOURNAL OF IMMUNOLOGY
ISSN 0022-1767
Vol. 186
N° 2
Año 2011
Págs.807 - 815
IL-12 is a potent immunostimulatory cytokine, but its impact as an antitumor drug in clinical practice is limited. Upsurge of regulatory T cells (Treg) in the tumor milieu has been proposed to limit the efficacy of the treatment.
Revista:
Expert Opinion on Pharmacotherapy
ISSN 1465-6566
Vol. 12
N° 7
Año 2011
Págs.1057 - 1073
Revista:
Journal of Hepatology
ISSN 0168-8278
Vol. 55
N° 4
Año 2011
Págs.828 - 837
Revista:
PLoS One
ISSN 1932-6203
Vol. 6
N° 12
Año 2011
Págs.28717
Background & Aims: Secretin induces bicarbonate-rich hydrocholeresis in healthy individuals, but not in untreated patients with primary biliary cirrhosis (PBC). Ursodeoxycholic acid (UDCA) - the first choice treatment for PBC - restores the secretin response. Compared with humans, secretin has poor effect in experimental normal-rat models with biliary drainage, although it may elicit hydrocholeresis when the bile-acid pool is maintained. In view of the benefits of UDCA in PBC, we used normal-rat models to unravel the acute contribution of UDCA (and/or taurine-conjugated TUDCA) for eliciting the biliary secretin response.
Methods: Intravascular and/or intrabiliary administration of agonists and inhibitors was performed in normal rats with biliary monitoring. Secretin/bile-acid interplay was analyzed in 3D cultured rat cholangiocytes that formed expansive cystic structures with intralumenal hydroionic secretion.
Results: In vivo, secretin stimulates hydrocholeresis upon UDCA/TUDCA infusion, but does not modify the intrinsic hypercholeretic effect of dehydrocholic acid (DHCA). The former effect is dependent on microtubule polymerization, and involves PKC alpha, PI3K and MEK pathways, as shown by colchicine (i.p.) and retrograde biliary inhibitors. In vitro, while secretin alone accelerates the spontaneous expansion of 3D-cystic structures, this effect is enhanced in the presence of TUDCA, but not UDCA or DHCA. Experiments with inhibitors and Ca(2+)-chelator confirmed that the synergistic effect of secretin plus TUDCA involves microtubules, intracellular Ca(2+), PKC alpha, PI3K, PKA and MEK pathways. Gene silencing also demonstrated the involvement of the bicarbonate extruder Ae2.
Revista:
NEW BIOTECHNOLOGY
ISSN 1871-6784
Vol. 27
N° 2
Año 2010
Págs.138 - 148
Revista:
JOURNAL OF IMMUNOLOGY
ISSN 0022-1767
Vol. 185
N° 9
Año 2010
Págs.5150 - 5159
Immunosuppressive activity of regulatory T cells (Treg) may contribute to the progression of cancer or infectious diseases by preventing the induction of specific immune responses. Using a phage-displayed random peptide library, we identified a 15-mer synthetic peptide, P60, able to bind to forkhead/winged helix transcription factor 3 (FOXP3), a factor required for development and function of Treg. P60 enters the cells, inhibits FOXP3 nuclear translocation, and reduces its ability to suppress the transcription factors NF-¿B and NFAT. In vitro, P60 inhibited murine and human-derived Treg and improved effector T cell stimulation. P60 administration to newborn mice induced a lymphoproliferative autoimmune syndrome resembling the reported pathology in scurfy mice lacking functional Foxp3. However, P60 did not cause toxic effects in adult mice and, when given to BALB/c mice immunized with the cytotoxic T cell epitope AH1 from CT26 tumor cells, it induced protection against tumor implantation. Similarly, P60 improved the antiviral efficacy of a recombinant adenovirus expressing NS3 protein from hepatitis C virus. Functional inhibition of Treg by the FOXP3-inhibitory peptide P60 constitutes a strategy to enhance antitumor and antiviral immunotherapies.
Revista:
Cancer Gene Therapy (Print)
ISSN 0929-1903
Vol. 17
N° 12
Año 2010
Págs.837 - 843
Revista:
International Journal of Radiation Oncology, Biology, Physics
ISSN 0360-3016
Vol. 77
N° 5
Año 2010
Págs.1441 - 1448
Revista:
Hepatology
ISSN 0270-9139
Vol. 51
N° 3
Año 2010
Págs.891 - 902
Revista:
Hepatology
ISSN 0270-9139
Vol. 52
N° 2
Año 2010
Págs.667 - 677
Revista:
GASTROENTEROLOGY
ISSN 0016-5085
Vol. 139
N° 3
Año 2010
Págs.726 - 729
Revista:
European Journal of Immunology
ISSN 0014-2980
Vol. 40
N° 12
Año 2010
Págs.3389 - 3402
Revista:
Current Opinion in molecular therapheutics
ISSN 1464-8431
Vol. 12
N° 5
Año 2010
Págs.561 - 569
In contrast to the large quantity of preclinical evidence for efficacy, few gene therapy agents have reached clinical development for the treatment of primary and secondary liver cancer. This review discusses the published clinical trials that have explored the feasibility, safety and efficacy of gene therapy strategies for the treatment of liver cancer. Strategies include restoration of tumor suppressor genes, genetic prodrug-activating therapy, genetic immunotherapy and oncolytic virotherapy. In these trials, transgene expression of varying degrees has been detected. Globally, gene therapy has proven to be safe, with none of the agents tested reaching the MTD. Although none of the phase II trials provided significant response rates, objective remissions have occasionally been observed and proof-of-concept for the ability of gene therapy to produce significant tumor cell killing has been determined. Insufficient delivery following intravascular administration and short-lived transgene expression are likely to be the cause of this limited antitumor efficacy. The development of new gene therapy vectors with improved characteristics will increase the probability of success of gene therapy for the treatment of liver cancer.
Revista:
VACCINE
ISSN 0264-410X
Vol. 28
N° 32
Año 2010
Págs.5323 - 5331
Revista:
WORLD JOURNAL OF GASTROENTEROLOGY
ISSN 1007-9327
Vol. 16
N° 25
Año 2010
Págs.3091 - 3102
Pre-mRNA splicing is an essential step in the process of gene expression in eukaryotes and consists of the removal of introns and the linking of exons to generate mature mRNAs. This is a highly regulated mechanism that allows the alternative usage of exons, the retention of intronic sequences and the generation of exonic sequences of variable length. Most human genes undergo splicing events, and disruptions of this process have been associated with a variety of diseases, including cancer. Hepatocellular carcinoma (HCC) is a molecularly heterogeneous type of tumor that usually develops in a cirrhotic liver. Alterations in pre-mRNA splicing of some genes have been observed in liver cancer, and although still scarce, the available data suggest that splicing defects may have a role in hepatocarcinogenesis. Here we briefly review the general mechanisms that regulate pre-mRNA splicing, and discuss some examples that illustrate how this process is impaired in liver tumorigenesis, and may contribute to HCC development. We believe that a more thorough examination of pre-mRNA splicing is still needed to accurately draw the molecular portrait of liver cancer. This will surely contribute to a better understanding of the disease and to the development of new effective therapies. (C) 2010 Baishideng. All rights reserved.
Revista:
Hepatology
ISSN 0270-9139
Vol. 51
N° 3
Año 2010
Págs.912 - 921
We investigated whether gene transfer of insulin-like growth factor I (IGF-I) to the hepatic tissue was able to improve liver histology and function in established liver cirrhosis. Rats with liver cirrhosis induced by carbon tetrachloride (CCl4) given orally for 8 weeks were injected through the hepatic artery with saline or with Simian virus 40 vectors encoding IGF-I (SVIGF-I), or luciferase (SVLuc). Animals were sacrificed 8 weeks after vector injection. In cirrhotic rats we observed that, whereas IGF-I was synthesized by hepatocytes, IGF-I receptor was predominantly expressed by nonparenchymal cells, mainly in fibrous septa surrounding hepatic nodules. Rats treated with SVIGF-I showed increased hepatic levels of IGF-I, improved liver function tests, and reduced fibrosis in association with diminished ¿-smooth muscle actin expression, up-regulation of matrix metalloproteases (MMPs) and decreased expression of the tissue inhibitors of MMPs TIM-1 and TIM-2. SVIGF-I therapy induced down-regulation of the profibrogenic molecules transforming growth factor beta (TGFß), amphiregulin, platelet-derived growth factor (PDGF), connective tissue growth factor (CTGF), and vascular endothelium growth factor (VEGF) and induction of the antifibrogenic and cytoprotective hepatocyte growth factor (HGF). Furthermore, SVIGF-I-treated animals showed decreased expression of Wilms tumor-1 (WT-1; a nuclear factor involved in hepatocyte dedifferentiation) and up-regulation of hepatocyte nuclear factor 4 alpha (HNF4¿) (which stimulates hepatocellular differentiation). The therapeutic potential of SVIGF-I was also tested in rats with thioacetamide-induced liver cirrhosis. Also in this model, SVIGF-I improved liver function and reduced liver fibrosis in association with up-regulation of HGF and MMPs and down-regulation of tissue inhibitor of metalloproteinase 1 (TIMP-1). Conclusion: IGF-I gene transfer to cirrhotic livers induces MMPs and hepatoprotective factors leading to reversion of fibrosis and improvement of liver function. IGF-I gene therapy may be a useful alternative therapy for patients with advanced cirrhosis without timely access to liver transplantation.
Revista:
Molecular Therapy
ISSN 1525-0016
Vol. 18
N° 4
Año 2010
Págs.754 - 765
Revista:
PLoS One
ISSN 1932-6203
Vol. 5
N° 12
Año 2010
Págs.e15690
Background: Inflammation and fibrogenesis are directly related to chronic liver disease progression, including hepatocellular carcinoma (HCC) development. Currently there are few therapeutic options available to inhibit liver fibrosis. We have evaluated the hepatoprotective and anti-fibrotic potential of orally-administered 59-methylthioadenosine (MTA) in Mdr2(-/-) mice, a clinically relevant model of sclerosing cholangitis and spontaneous biliary fibrosis, followed at later stages by HCC development.
Methodology: MTA was administered daily by gavage to wild type and Mdr2(-/-) mice for three weeks. MTA anti-inflammatory and anti-fibrotic effects and potential mechanisms of action were examined in the liver of Mdr2(-/-) mice with ongoing fibrogenesis and in cultured liver fibrogenic cells (myofibroblasts).
Principal Findings: MTA treatment reduced hepatomegaly and liver injury. alpha-Smooth muscle actin immunoreactivity and collagen deposition were also significantly decreased. Inflammatory infiltrate, the expression of the cytokines IL6 and Mcp-1, pro-fibrogenic factors like TGF beta 2 and tenascin-C, as well as pro-fibrogenic intracellular signalling pathways were reduced by MTA in vivo. MTA inhibited the activation and proliferation of isolated myofibroblasts and down-regulated cyclin D1 gene expression at the transcriptional level. The expression of JunD, a key transcription factor in liver fibrogenesis, was also reduced by MTA in activated myofibroblasts.
Conclusions/Significance: Oral MTA administration was well tolerated and proved its efficacy in reducing liver inflammation and fibrosis. MTA may have multiple molecular and cellular targets. These include the inhibition of inflammatory and profibrogenic cytokines, as well as the attenuation of myofibroblast activation and proliferation. Downregulation of JunD and cyclin D1 expression in myofibroblasts may be important regarding the mechanism of action of MTA. This compound could be a good candidate to be tested for the treatment of (biliary) liver fibrosis.
Revista:
Journal of Hepatology
ISSN 0168-8278
Vol. 52
N° 3
Año 2010
Págs.417 - 424
Background & Aims: Acute intermittent porphyria (AIP) is characterized by hepatic porphobilinogen deaminase (PBGD) deficiency resulting in a marked overproduction of presumably toxic porphyrin precursors. Our study aimed to assess the protective effects of bone marrow transplantation or PBGD gene transfer into the liver against phenotypic manifestations of acute porphyria attack induced in an AIP murine model. Methods: Lethally irradiated AIP mice were intravenously injected with 5×106 nucleated bone marrow cells from wild type or AIP donor mice. To achieve liver gene transfer, AIP mice received via hydrodynamic injection plasmids expressing human PBGD or luciferase, driven by a liver-specific promoter. Results: Erythrocyte PBGD activity increased 2.4-fold in AIP mice receiving bone marrow cells from normal animals. Nevertheless, phenobarbital administration in these mice reproduced key features of acute attacks, such as massively increased urinary porphyrin precursor excretion and decreased motor coordination. Hepatic PBGD activity increased 2.2-fold after hydrodynamic injection of therapeutic plasmid. Mice injected with the luciferase control plasmid showed a high excretion of porphyrin precursors after phenobarbital administration whereas just a small increase was observed in AIP mice injected with the PBGD plasmid. Furthermore, motor disturbance was almost completely abolished in AIP mice treated with the therapeutic plasmid. Conclusions: PBGD deficiency in erythroid tissue is not associated with phenotypic manifestations of acute porphyria. In contrast, PBGD over-expression in hepatocytes, albeit in a low proportion, reduced precursor accumulation, which is the hallmark of acute porphyric attacks. Liver-directed gene therapy might offer an alternative to liver transplantation applicable in patients with severe and recurrent manifestations.
Revista:
PROTEOMICS
ISSN 1615-9853
Vol. 10
N° 8
Año 2010
Págs.1609 - 1620
Prohibitin is a multifunctional protein participating in a plethora of essential cellular functions, such as cell signaling, apoptosis, survival and proliferation. In the liver, deficient prohibitin activity participates in the progression of non-alcoholic steatohepatitis and obesity, according to mechanisms that still must be elucidated. In this study, we have used a combination of transcriptomics and proteomics technologies to investigate the response of human hepatoma PLC/PRF/5 cells to prohibitin silencing to define in detail the biological function of hepatic Phb1 and to elucidate potential prohibitin-dependent mechanisms participating in the maintenance of the transformed phenotype. Abrogation of prohibitin reduced proliferation and induced apoptosis in human hepatoma cells in a mechanism dependent on NF kappaB signaling. Moreover, down-regulation of ERp29 together with down-regulation of Erlin 2 suggests ER stress. In agreement, increased C/EBP homologous protein levels, poly-ADP ribose polymerase cleavage and activation of caspase 12 and downstream caspase 7 evidenced ER stress-induced apoptosis. Down-regulation of proteasome activator complex subunit 2 and stathmin as well as accumulation of ubiquitinated proteins suggest interplay between ER stress and proteasome malfunction. Taken together, our results provide evidences for prohibitin having a central role in the maintenance of the transformed and invasive phenotype of human hepatoma cells and may further support previous studies suggesting prohibitin as a potential clinical target.
Revista:
Molecular Therapy
ISSN 1525-0016
Vol. 19
N° 2
Año 2010
Págs.243 - 250
Acute intermittent porphyria (AIP) is characterized by a hereditary deficiency of hepatic porphobilinogen deaminase (PBGD) activity. Clinical features are acute neurovisceral attacks accompanied by overproduction of porphyrin precursors in the liver. Recurrent life-threatening attacks can be cured only by liver transplantation. We developed recombinant adeno-associated virus (rAAV) vectors expressing human PBGD protein driven by a liver-specific promoter to provide sustained protection against induced attacks in a predictive model for AIP. Phenobarbital injections in AIP mice induced porphyrin precursor accumulation, functional block of nerve conduction, and progressive loss of large-caliber axons in the sciatic nerve. Hepatocyte transduction showed no gender variation after rAAV2/8 injection, while rAAV2/5 showed lower transduction efficiency in females than males. Full protection against induced phenobarbital-attacks was achieved in animals showing over 10% of hepatocytes expressing high amounts of PBGD. More importantly, sustained hepatic expression of hPBGD protected against loss of large-caliber axons in the sciatic nerve and disturbances in nerve conduction velocity as induced by recurrent phenobarbital administrations. These data show for the first time that porphyrin precursors generated in the liver interfere with motor function. rAAV2/5-hPBGD vector can be produced in sufficient quantity for an intended gene therapy trial in patients with recurrent life-threatening porphyria attacks.
Revista:
CANCER IMMUNOLOGY IMMUNOTHERAPY
ISSN 0340-7004
Vol. 59
N° 8
Año 2010
Págs.1223 - 1233
Revista:
VACCINE
ISSN 0264-410X
Vol. 28
N° 44
Año 2010
Págs.7146-7154
Staphylococcus epidermidis releases a complex of at least four peptides, termed phenol-soluble modulins (PSM), which stimulate macrophages to produce proinflammatory cytokines via activation of TLR2 signalling pathway. We demonstrated that covalent linkage of PSM peptides to an antigen facilitate its capture by dendritic cells and, in combination with different TLR ligands, can favour the in vivo induction of strong and persistent antigen-specific immune responses. Treatment of mice grafted with HPV16-E7-expressing tumor cells (TC-1)with poly(l: C) and a peptide containing alpha Mod linked to the H-2D(b)-restricted cytotoxic T-cell epitope E7(49-57) from HPV16-E7 protein allowed complete tumor regression in 100% of the animals. Surprisingly, this immunomodulatory property of modulin-derived peptides was TLR2 independent and partially dependent upon the EGF-receptor signalling pathway. Our results suggest that alpha or gamma modulin peptides may serve as a suitable antigen carrier for the development of anti-tumoral or anti-viral vaccines. (C) 2010 Elsevier Ltd. All rights reserved.
