Nuestros investigadores

María Jesús López Zabalza

Publicaciones científicas más recientes (desde 2010)

Autores: Ivars Lleó, Marta; España Alonso, Agustín (Autor de correspondencia); Alzuguren Maza, María Pilar; et al.
Revista: BRITISH JOURNAL OF DERMATOLOGY
ISSN 0007-0963  Vol. 182  Nº 5  2020  págs. 1194 - 1204
Background Acantholysis in pemphigus vulgaris (PV) may be triggered by desmoglein (Dsg) and non-Dsg autoantibodies. The autoantibody profile of each patient results in distinct intracellular signalling patterns. Objectives Based on our previous findings, we aimed to elucidate whether PV acantholysis in a mouse model may be mediated by activation of a disintegrin and metalloproteinase 10 (ADAM10). Methods We used three PV-IgG fractions from different patients containing high or low levels of anti-Dsg1 and anti-Dsg3 antibodies, and the presence or not of anti-desmocollin (Dsc) antibodies, using a passive transfer mouse model of PV. Results Although all of the PV-IgG fractions produced suprabasal acantholysis, only those containing anti-Dsg1/3, but not anti-Dsc2/3 antibodies, induced ADAM10 activation in a Src-dependent way, and an increase in the epidermal growth factor (EGF) receptor ligands EGF and betacellulin (BTC). In contrast, the presence of anti-Dsc2/3 antibodies, in addition to anti-Dsg1/3, triggered earlier and ADAM10-independent epidermal detachment, with no increase in EGF and BTC, which was associated with an earlier and more intense acantholysis. Conclusions All PV-IgG fractions produced suprabasal acantholysis, but our results reveal that depending on the levels of anti-Dsg antibodies or the presence of non-Dsg antibodies, such as anti-Dsc, more severe cell-cell epidermal detachment will occur at different times, and in an ADAM10-dependent manner or not. Acantholysis in these different groups of patients with PV may be a consequence of the activation of specific intracellular mechanisms downstream of Autoantibodies binding to Dsg or non-Dsg proteins, and therefore more specific therapeutic approaches in PV should be used. What's already known about this topic? Suprabasal acantholysis in pemphigus vulgaris (PV) may be triggered by both desmoglein (Dsg) and non-Dsg autoantibodies. The autoantibody profile of each patient is associated with a distinct intracellular signalling pattern. What does this study add? In patients with PV with anti-Dsg3 and anti-Dsg1, but not anti-desmocollin (Dsc)3 antibodies, ADAM10 activation is induced in an Src-dependent way, together with an increase in the epidermal growth factor receptor (EGFR) ligands EGF and betacellulin. The presence of anti-Dsc3 antibodies triggers an earlier and ADAM10-independent acantholysis, without increasing EGFR ligands, and is associated with more severe epidermal detachment. Lower levels of anti-Dsc3 antibodies are associated with less severe acantholysis. What is the translational message? In some patients with PV, the severity and the timing for cell-cell detachment seem to depend on the level of anti-Dsg1/3 antibodies, although other as yet uncharacterized antibodies may also participate. These patients with PV would exhibit inhibition of acantholysis by Src, ADAM10, EGF and EGFR inhibitors. In other patients, the presence of non-Dsg antibodies, such as anti-Dsc2/3, would produce an earlier and more severe ADAM10-independent suprabasal acantholysis.
Autores: Navarro Corcuera, Amaia; López Zabalza, María Jesús; Martínez Irujo, Juan José; et al.
Revista: BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH
ISSN 0167-4889  Vol. 1866  Nº 4  2019  págs. 673 - 685
Liver damage induces hepatic stellate cells (HSC) activation, characterised by a fibrogenic, proliferative and migratory phenotype. Activated HSC are mainly regulated by transforming growth factor ß 1 (TGFß1), which increases the production of extracellular matrix proteins (e.g. collagen-I) promoting the progression of hepatic fibrosis. AGAP2 (ArfGAP with GTPase domain, ankyrin repeat and PH domain 2) is a GTPase/GTP-activating protein involved in the actin remodelling system and receptor recycling. In the present work the role of AGAP2 in human HSC in response to TGFß1 was investigated. LX-2 HSC were transfected with AGAP2 siRNA and treated with TGFß1. AGAP2 knockdown prevented to some extent the proliferative and migratory TGFß1-induced capacities of LX-2 cells. An array focused on human fibrosis revealed that AGAP2 knockdown partially prevented TGFß1-mediated gene expression of the fibrogenic genes ACTA2, COL1A2, EDN1, INHBE, LOX, PDGFB, TGF¿12, while favored the expression of CXCR4, IL1A, MMP1, MMP3 and MMP9 genes. Furthermore, TGFß1 induced AGAP2 promoter activation and its protein expression in LX-2. Moreover, AGAP2 protein levels were significantly increased in liver samples from rats with thioacetamide-induced fibrosis. In addition, AGAP2 silencing affected TGFß1-receptor 2 (TGFR2) trafficking in U2OS cells, blocking its effective recycling to the membrane. AGAP2 silencing in LX-2 cells prevented the TGFß1-induced increase of collagen-I protein levels, while its overexpression enhanced collagen-I protein expression in the presence or absence of the cytokine. AGAP2 overexpression also increased focal adhesion kinase (FAK) phosphorylated levels in LX-2 cells. FAK and MEK1 inhibitors prevented the increase of collagen-I expression caused by TGFß1 in LX-2 overexpressing AGAP2. In summary, the present work shows for the first time, that AGAP2 is a potential new target involved in TGFß1 signalling, contributing to the progression of hepatic fibrosis.
Autores: Andueza Lizarraga, Aitor; Garde, N.; García Garzón, María Antonia; et al.
Revista: FREE RADICAL BIOLOGY AND MEDICINE
ISSN 0891-5849  Vol. 126  2018  págs. 15 - 26
NADPH oxidase (Nox) variants Nox1, Nox2 and Nox4 are implicated in the progression of liver fibrosis. However, the role of Nox5 is not yet known, mainly due to the lack of this enzyme in rat and mouse genomes. Here we describe the expression and functional relevance of Nox5 in the human cell line of hepatic stellate cells (HSC) LX-2. Under basal conditions, three long (Nox5-L: Nox5 alpha, -beta, and -delta) and a short (Nox5-S or Nox5 epsilon) splice variants were detected, which were silenced with specific siRNAs for Nox5. The most abundant isoform was Nox5-S, accounting for more than 90% of Nox5 protein. Overexpression of Nox5 beta generated reactive oxygen species (ROS) in the presence of calcium, as judged by the production of hydrogen peroxide, L-012 luminescence and cytochrome c reduction. Nox5 epsilon did not generated ROS under these conditions, and a reduced ROS production was observed when co-expressed with Nox5 beta. In contrast, dihydroethidium oxidation was increased by Nox5 beta or Nox5 epsilon, suggesting that Nox5 epsilon induced intracellular oxidative stress by an unknown mechanism. Functional studies showed that both Nox5 beta and Nox5 epsilon stimulated the proliferation of LX-2 cells and the collagen type I levels, while Nox5 siRNAs inhibited these effects. Interestingly, TGF-beta and angiotensin II upregulated Nox5 expression, which was reduced in cells pre-incubated with catalase. Further studies silencing Nox5 in TGF-beta-treated cells resulted in a reduction of collagen levels via p38 MAPK. Collectively, these results show for the first time that Nox5 can play a relevant role in the proliferation and fibrosis on human HSC.
Autores: Andueza Lizarraga, Aitor; Garde, N. ; García Garzón, María Antonia; et al.
Revista: FREE RADICAL BIOLOGY AND MEDICINE
ISSN 0891-5849  Vol. 120  2018  págs. S86 - S86
NADPH oxidase (Nox) variants Nox1, Nox2 and Nox4 have been implicated in the progression of liver fibrosis. However, the role of Nox5 is unknown, mainly due to the lack of this enzyme in rat and mouse genomes. Here we describe the expression and functional relevance of Nox5 in the human cell line of hepatic stellate cells (HSC), LX-2. Under basal conditions, these cells expressed a long (Nox5L) and a short (Nox5S) variant which were silenced with specific siRNAs for Nox5. Overexpression of Nox5L generated ROS in the presence of calcium, as judged by the production of extracellular hydrogen peroxide, L-012 luminescence and cytochrome c reduction, while Nox5S did not generated ROS under these conditions. In contrast, dihydroethidium oxidation was increased when either Nox5L or Nox5S were overexpressed. Functional studies revealed that both Nox5L and Nox5S stimulated the proliferation of LX-2 cells and the synthesis of type I collagen, while Nox5 siRNAs inhibited these effects. Interestingly, TGF-beta and angiotensin II induced Nox5, and silencing Nox5 reduced collagen production stimulated by TGF-beta. Collectively, these results suggest for the first time that Nox5 can play a relevant role in HSC proliferation and fibrogenesis.
Autores: Ruíz de Galarreta Martínez, Marina; Navarro, A.; Ansorena Artieda, Eduardo; et al.
Revista: BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH
ISSN 0167-4889  Vol. 1863  Nº 8  2016  págs. 2115 - 2123
Unfolded protein response (UPR) triggered as a consequence of ER stress has been shown to be involved in the development of different pathologies, including fibrotic disorders. In the present paper we explore the role played by UPR on a key fibrogenic parameter in the liver: collagen type I levels in activated hepatic stellate cells (HSC). Using Brefeldin A (BFA) as an ER stress inducer we found that UPR correlated with enhanced mRNA and protein levels of collagen type I in a cell line of immortalized non-tumoral rat HSC. Analysis of the three branches of UPR revealed the activation of IRE1¿, PERK and ATF6 in response to BFA, although PERK activation was shown not to be involved in the fibrogenic action of BFA. BFA also activated p38 MAPK in an IRE1¿-dependent way and the p38 MAPK inhibitor SB203580 prevented the increase in collagen type I mRNA and protein levels caused by BFA, suggesting the involvement of this kinase on this effect. Analysis of Smad activation showed that phosphorylated nuclear levels of Smad2 and 3 were increased in response to BFA treatment. Inhibition of Smad3 phosphorylation by SIS3 prevented the enhancement of collagen type I levels caused by BFA. Pretreatment with IRE1¿ and p38 MAPK inhibitors also prevented the increased p-Smad3 accumulation in the nucleus, suggesting an IRE1¿-p38 MAPK-Smad pathway to be responsible for the fibrogenic action of BFA on HSC.
Autores: Razzaque, A.; Carrozo, M.; Caux, F.; et al.
Revista: EXPERIMENTAL DERMATOLOGY
ISSN 0906-6705  Vol. 25  Nº 11  2016  págs. 839 - 846
This viewpoint highlights major, partly controversial concepts about the pathogenesis of pemphigus. The monopathogenic theory explains intra-epidermal blistering through the "desmoglein (Dsg) compensation" hypothesis, according to which an antibody-dependent disabling of Dsg 1- and/or Dsg 3-mediated cell-cell attachments of keratinocytes (KCs) is sufficient to disrupt epidermal integrity and cause blistering. The multipathogenic theory explains intra-epidermal blistering through the "multiple hit" hypothesis stating that a simultaneous and synchronized inactivation of the physiological mechanisms regulating and/or mediating intercellular adhesion of KCs is necessary to disrupt epidermal integrity. The major premise for a multipathogenic theory is that a single type of autoantibody induces only reversible changes, so that affected KCs can recover due to a self-repair. The damage, however, becomes irreversible when the salvage pathway and/or other cell functions are altered by a partnering autoantibody and/or other pathogenic factors. Future studies are needed to (i) corroborate these findings, (ii) characterize in detail patient populations with non-Dsg-specific autoantibodies, and (iii) determine the extent of the contribution of non-Dsg antibodies in disease pathophysiology.
Autores: Andueza, A.; García Garzón, María Antonia; Ruiz de Galarreta, M.; et al.
Revista: FREE RADICAL BIOLOGY AND MEDICINE
ISSN 0891-5849  Vol. 87  2015  págs. 169 - 180
Apigenin, a natural flavone, is emerging as a promising compound for the treatment of several diseases. One of the hallmarks of apigenin is the generation of intracellular reactive oxygen species (ROS), as judged by the oxidation of reduced dichlorofluorescein derivatives seen in many cell types. This study aimed to reveal some mechanisms by which apigenin can be oxidized and how apigenin-derived radicals affect the oxidation of 5-(and-6)-chloromethyl-2',7'-dichloroclihydrolluorescein (H2DCF), a probe usually employed to detect intracellular ROS. Apigenin induced a rapid oxidation of H2DCF in two different immortalized cell lines derived from rat and human hepatic stellate cells. However, apigenin did not generate ROS in these cells, as judged by dihydroethidium oxidation and extracellular hydrogen peroxide production. In cell -free experiments we found that oxidation of apigenin leads to the generation of a phenoxyl radical, which directly oxidizes H2DCF with catalytic amounts of hydrogen peroxide. The net balance of the reaction was the oxidation of the probe by molecular oxygen due to redox cycling of apigenin. This flavonoid was also able to deplete NADH and glutathione by a similar mechanism. InLeresLingly, H2DCF oxidation was significantly accelerated by apigenin in the presence of horseradish peroxidase and xarahine oxidase, but not with other enzymes showing peroxiclase-like activity, such as cylochrome c or calalase. We conclude that in cells treated with apigenin oxidation of reduced clichlorofluorescein derivatives does not measure intracellular ROS and that pro- and antioxidant effects of flavonoids deduced from these experiments are inconclusive and must be confirmed by other techniques.
Autores: Mòdol Betriu, Maria Teresa; Brice López, Natalia; Ruíz de Galarreta Martínez, Marina; et al.
Revista: JOURNAL OF CELLULAR PHYSIOLOGY
ISSN 0021-9541  Vol. 230  Nº 3  2015  págs. 546 - 553
The turnover of extracellular matrix (ECM) components can generate signals that regulate several cellular functions such as proliferation, differentiation, and apoptosis. During liver injury, matrix metalloproteases (MMPs) production is enhanced and increased levels of peptides derived from extracellular matrix proteins can be generated. Synthetic peptides with sequences present in extracellular matrix proteins were previously found to induce both stimulating and apoptotic effects on several cell types including the inflammatory cells monocytes/macrophages. Therefore, in inflammatory liver diseases, locally accumulated peptides could be also important in regulating hepatic fibrosis by inducing apoptosis of hepatic stellate cells (HSC), the primary cellular source of extracellular matrix components. Here, we describe the apoptotic effect of fibronectin peptides on the cell line of human hepatic stellate cells LX-2 based on oligonucleosomal DNA fragmentation, caspase-3 and -9 activation, Bcl-2 depletion, and accumulation of Bax protein. We also found that these peptides trigger the activation of Src kinase, which in turn mediated the increase of JNK and p38 activities. By the use of specific inhibitors we demonstrated the involvement of Src, JNK, and p38 in apoptosis induced by fibronectin peptides on HSC. Moreover, fibronectin peptides increased iNOS expression in human HSC, and specific inhibition of iNOS significantly reduced the sustained activity of JNK and the programmed
Autores: España Alonso, Agustín; Mòdol Betriu, Maria Teresa; Gil Sánchez, María Pilar; et al.
Revista: EXPERIMENTAL DERMATOLOGY
ISSN 0906-6705  Vol. 22  Nº 2  2013  págs. 125 - 130
Pemphigus vulgaris (PV) is an autoimmune blistering skin disease characterized by suprabasal acantholysis produced as a consequence of desmoglein (Dsg) and non-Dsg autoantibodies binding to several targeting molecules localized on the membrane of keratinocytes. Nitric oxide (NO) may exert a pathogenic function in several immunological processes. We have previously demonstrated that neural nitric oxide synthase (nNOS) plays part in PV acantholysis. Also, our group has described a relevant role for HER [human epidermal growth factor receptor (EGFR) related] isoforms and several kinases such as Src (Rous sarcoma), mammalian target of rapamycin (mTOR) and focal adhesion kinase (FAK), as well as caspases in PV development. Using a passive transfer mouse model of PV, we aimed to investigate the relationship between the increase in nNOS and EGFR, Src, mTOR and FAK kinase upregulation observed in PV lesions. Our results revealed a new function for nNOS, which contributes to EGFR-mediated PV acantholysis through the upregulation of Src, mTOR and FAK. In addition, we found that nNOS participates actively in PV at least in part by increasing caspase-9 and caspase-3 activities. These findings underline the important issue that in PV acantholysis, caspase activation is a nNOS-linked process downstream of Src, mTOR and FAK kinase upregulation.
Autores: Arriazu Ruiz, Elena; Ruíz de Galarreta Martínez, Marina; López Zabalza, María Jesús; et al.
Revista: LABORATORY INVESTIGATION
ISSN 0023-6837  Vol. 93  Nº 3  2013  págs. 303-310
General control nonderepresible 2 (GCN2) is a highly conserved cytosolic kinase that modulates a complex response for coping with the stress owing to lack of amino acids. GCN2 has been recently shown to be involved in the regulation of metabolic balance and lipid degradation rate in the liver. We hypothesized that GCN2 could have a role in in hepatic fibrogenesis and in the response to acute or chronic liver injury. Activation of GCN2 in primary or immortalized human hepatic stellate cells by incubation with medium lacking the essential amino acid histidine correlated with decreased levels of collagen type I protein and mRNA, suggesting an antifibrogenic effect of GCN2. In vivo studies with Gcn2 knockout mice (Gcn2(-/-)) showed increased susceptibility to both acute or chronic liver damage induced by CCl4, as shown by higher alanine aminotransferase and aspartate aminotransferase activities, increased necrosis and higher inflammatory infiltrates compared with wild-type mice (WT). Chronic CCl4 treatment increased deposition of interstitial collagen type I more in Gcn2(-/-) mice than in WT mice. Col1a1 and col1a2 mRNA levels also increased in CCl4-treated Gcn2(-/-) mice compared with WT mice. These results suggest that GCN2 is a key regulator of the fibrogenic response to liver injury. Laboratory Investigation (2013) 93, 303-310; doi:10.1038/labinvest.2012.173; published online 14 January 2013
Autores: Gil Sánchez, María Pilar; Mòdol Betriu, Maria Teresa; España Alonso, Agustín; et al.
Revista: Experimental Dermatology
ISSN 0906-6705  Vol. 21  Nº 4  2012  págs. 254 - 259
Autores: Mòdol Betriu, Maria Teresa; Ruíz de Galarreta Martínez, Marina; García Garzón, María Antonia; et al.
Revista: FEBS JOURNAL
ISSN 1742-464X  Vol. 279  Nº Supl. 1  2012  págs. 317 - 318
Autores: Mòdol Betriu, Maria Teresa; Natal Gorgojo, Cristina; Pérez de Obanos Martell, María Pilar; et al.
Revista: Biochemical Pharmacology
ISSN 0006-2952  Vol. 81  Nº 3  2011  págs. 451 - 458
Autores: Arriazu Ruiz, Elena; Pérez de Obanos Martell, María Pilar; López Zabalza, María Jesús; et al.
Revista: CELL PHYSIOL BIOCHEM
ISSN 1015-8987  Vol. 26  Nº 3  2010  págs. 281 - 290
Autores: Arriazu Ruiz, Elena; Pérez de Obanos Martell, María Pilar; López Zabalza, María Jesús; et al.
Revista: HEPATOLOGY
ISSN 0270-9139  Vol. 52  Nº 4  2010  págs. 1283A