Nuestros investigadores

María Ángela Burrell Bustos

Departamento
Patología - Anatomía y Fisiología
Facultad de Medicina. Universidad de Navarra
Líneas de investigación
Estudio de: 1) Sustancias reguladoras en el aparato digestivo, con especial referencia al control del apetito. 2) Tejido adiposo en la obesidad, especialmente los cambios tras restricción calórica (convencional e inducida por cirugía bariátrica).
Índice H
19, (WoS, 26/08/2019)

Publicaciones científicas más recientes (desde 2010)

Autores: Lorente, Silvia; Martinez-Fernandez, L.; et al.
Revista: INTERNATIONAL JOURNAL OF OBESITY
ISSN 0307-0565  Vol. 42  Nº 3  2018  págs. 572 - 579
BACKGROUND/OBJECTIVES: The aim of this study was to characterize the effects of Maresin 1 (MaR1) in obesity-related liver steatosis and the mechanisms involved. METHODS: MaR1 effects on fatty liver disease were tested in ob/ob (2-10 mu g kg(-1) i.p., 20 days) and in diet-induced obese (DIO) mice (2 mu g kg(-1), i.p., or 50 mu g kg(-1), oral gavage for 10 days), as well as in cultured hepatocytes. RESULTS: In ob/ob mice, MaR1 reduced liver triglycerides (TG) content, fatty acid synthase (FAS) and stearoyl-CoA desaturase-1 protein expression, while increased acetyl-CoA carboxylase (ACC) phosphorylation and LC3II protein expression, in parallel with a drop in p62 levels. Similar effects on hepatic TG, ACC phosphorylation, p62 and LC3II were observed in DIO mice after MaR1 i.p. injection. Interestingly, oral gavage of MaR1 also decreased serum transaminases, reduced liver weight and TG content. MaR1-treated mice exhibited reduced hepatic lipogenic enzymes content (FAS) or activation (by phosphorylation of ACC), accompanied by upregulation of carnitine palmitoyltransferase (Cpt1a), acyl-coenzyme A oxidase (Acox1) and autophagy-related proteins 5 and 7 (Atg5-7) gene expression, along with increased number of autophagic vacuoles and reduced p62 protein levels. MaR1 also induced AMP-activated protein kinase (AMPK) phosphorylation in DIO mice and in primary hepatocytes, and AMPK inhibition completely blocked MaR1 effects on Cpt1a, Acox1, Atg5 and Atg7 expression. CONCLUSIONS: MaR1 ameliorates liver steatosis by decreasing lipogenic enzymes, while inducing fatty acid oxidation genes and autophagy, which could be related to AMPK activation. Thus, MaR1 may be a new therapeutic candidate for reducing fatty liver in obesity.
Autores: Martín, Marina; Rodríguez, Amaia; Gómez-Ambrosi, J; et al.
Revista: EUROPEAN JOURNAL OF CLINICAL INVESTIGATION
ISSN 0014-2972  Vol. 48  Nº Supl. 1  2018  págs. 207 - 208
Autores: Gonzalez-Borja, I. ; Martín, Marina; Rodríguez, Amaia; et al.
Revista: EUROPEAN JOURNAL OF CLINICAL INVESTIGATION
ISSN 0014-2972  Vol. 48  Nº Supl. 1  2018  págs. 204 - 205
Autores: Unamuno, X.; Becerril, Sara; Rodríguez, Amaia; et al.
Revista: EUROPEAN JOURNAL OF CLINICAL INVESTIGATION
ISSN 0014-2972  Vol. 48  Nº Supl.1  2018  págs. 193 - 194
Autores: Fernández, Marta; Prieto, Pedro Luis; et al.
Revista: BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS
ISSN 1388-1981  Vol. 1851  Nº 3  2015  págs. 273 - 281
Alpha-Lipoic acid (¿-Lip) is a natural occurring antioxidant with beneficial anti-obesity properties. The aim of this study was to investigate the putative effects of alpha-Lip on mitochondrial biogenesis and the acquirement of brown-like characteristics by subcutaneous adipocytes from overweight/obese subjects. Thus, fully differentiated human subcutaneous adipocytes were treated with alpha-Lip (100 and 250 ¿M) for 24 h for studies on mitochondrial content and morphology, mitochondrial DNA (mtDNA) copy number, fatty acid oxidation enzymes and brown/beige characteristic genes. The involvement of the Sirtuin1/Peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (SIRT1/PGC-1alpha) pathway was also evaluated. Our results showed that alpha-Lip increased mitochondrial content in cultured human adipocytes as revealed by electron microscopy and by mitotracker green labeling. Moreover, an enhancement in mtDNA content was observed. This increase was accompanied by an up-regulation of SIRT1 protein levels, a decrease in PGC-1alpha acetylation and up-regulation of Nuclear respiratory factor 1 (Nrf1) and Mitochondrial transcription factor (Tfam) transcription factors. Enhanced oxygen consumption and fatty acid oxidation enzymes, Carnitine palmitoyl transferase 1 and Acyl-coenzyme A oxidase (CPT-1 and ACOX) were also observed. Mitochondria from alpha-Lip-treated adipocytes exhibited some morphological characteristics of brown mitochondria, and alpha-Lip also induced up-regulation of some brown/beige adipocytes markers such as cell death-inducing DFFA-like effector a (Cidea) and T-box 1 (Tbx1). Moreover, alpha-Lip up-regulated PR domain containing 16 (Prdm16) mRNA levels in treated adipocytes. Therefore, our study suggests the ability of alpha-Lip to promote mitochondrial biogenesis and brown-like remodeling in cultured white subcutaneous adipocytes from overweight/obese donors.
Autores: Lancha, Andoni; Rodríguez, Alfredo; Catalán, V; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 9  Nº 5  2014  págs. e98398
Osteopontin (OPN) is a multifunctional extracellular matrix (ECM) protein involved in multiple physiological processes. OPN expression is dramatically increased in visceral adipose tissue in obesity and the lack of OPN protects against the development of insulin resistance and inflammation in mice. We sought to unravel the potential mechanisms involved in the beneficial effects of the absence of OPN. We analyzed the effect of the lack of OPN in the development of obesity and hepatic steatosis induced by a high-fat diet (HFD) using OPN-KO mice. OPN expression was upregulated in epididymal white adipose tissue (EWAT) and liver in wild type (WT) mice with HFD. OPN-KO mice had higher insulin sensitivity, lower body weight and fat mass with reduced adipose tissue ECM remodeling and reduced adipocyte size than WT mice under a HFD. Reduced MMP2 and MMP9 activity was involved in the decreased ECM remodeling. Crown-like structure number in EWAT as well as F4/80-positive cells and Emr1 expression in EWAT and liver increased with HFD, while OPN-deficiency blunted the increase. Moreover, our data show for the first time that OPN-KO under a HFD mice display reduced fibrosis in adipose tissue and liver, as well as reduced oxidative stress in adipose tissue. Gene expression of collagens Col1a1, Col6a1 and Col6a3 in EWAT and liver, as well as the profibrotic cytokine Tgfb1 in EWAT were increased with HFD, while OPN-deficiency prevented this increase. OPN deficiency prevented hepatic steatosis via reduction in the expression of molecules involved in the onset of fat accumulation such as Pparg, Srebf1, Fasn, Mogat1, Dgat2 and Cidec. Furthermore, OPN-KO mice exhibited higher body temperature and improved BAT function. The present data reveal novel mechanisms of OPN in the development of obesity, pointing out the inhibition of OPN as a promising target for the treatment of obesity and fatty liver.
Autores: Becerril, Sara; Gómez-Ambrosi, J; Martín, Marina; et al.
Revista: HISTOLOGY AND HISTOPATHOLOGY
ISSN 0213-3911  Vol. 28  Nº 13  2013  págs. 1411-1425
From a histological and functional point of view, two types of adipose tissue can be identified. As opposed to the mainly unilocular white adipocytes, brown adipocytes possess plenty of small multilocular lipid droplets and dissipate energy as heat. Moreover, two distinct types of brown adipose cells exist. In vivo fate mapping experiments of brown adipose tissue (BAT) precursors suggest that classical brown adipocytes and skeletal myoblasts originate from a common mesenchymal, myogenic factor 5 (Myf5)-positive precursor cell. In addition to the classical brown adipocytes, thermogenic brown-like adipocytes (brite/beige cells) may appear within white adipose tissue (WAT) depots, sharing many of the morphological and functional features of brown adipocytes, but arising from a Myf5-negative lineage. In humans, the conversion of white fat cells into brite adipocytes could be a strategy to increase energy expenditure. The zinc finger transcription factor Prdm16 controls the bidirectional fate decision between brown adipocytes and myoblasts. Prdm16 determines the brown fat-like programme and thermogenesis in both brown and white adipose tissues. Moreover, the expression of this transcriptional regulator is strongly correlated with beige cell-selective genes. From a therapeutical point of view, the potential of inducing BAT or the transdifferentiation of WAT into beige cells by enhancing Prdm16 expression, as well as the identification of mechanisms of Prdm16 function and regulation represent potentially exciting new approaches for treatment or prevention of obesity and related diseases.
Autores: Rodríguez, Amaia; Becerril, Sara; Valentí, Víctor; et al.
Revista: OBESITY SURGERY
ISSN 0960-8923  Vol. 22  Nº 11  2012  págs. 1786 - 1787
Autores: Rodríguez, Amaia; Becerril, Sara; Valentí, Víctor; et al.
Revista: OBESITY SURGERY
ISSN 0960-8923  Vol. 22  Nº 9  2012  págs. 1481 - 1490
Sleeve gastrectomy constitutes an effective surgical procedure for the treatment of morbid obesity. The aim of the present study was to establish the effects of sleeve gastrectomy and caloric restriction on weight loss and cardiovascular parameters in diet-induced obese (DIO) rats. Male Wistar DIO rats were subjected to surgical interventions (n = 30) (sham operation, sleeve gastrectomy, or pair-fed to the amount of food eaten by sleeve-gastrectomized animals and compared to lean control rats) or dietary interventions (n = 40) (fed ad libitum a normal diet (ND) or a high-fat diet or an ND with a caloric restriction of 25 %). Systolic blood pressure (SBP), diastolic blood pressure, and mean blood pressure values and heart rate (HR) were recorded in conscious, resting animals by noninvasive tail-cuff plethysmography before and 3 weeks after surgical or dietary interventions. Both sleeve gastrectomy and caloric restriction induced a reduction in body weight, whole-body adiposity, and serum leptin together with an increased excess weight loss in DIO rats. Sleeve gastrectomy was further associated with an improvement in insulin resistance and the lipid profile, as well as with a reduction in serum ghrelin levels. A decrease in HR and heart weight was observed in caloric-restricted groups. Sleeve-gastrectomized rats not only exhibited a reduction in HR (a dagger HR = -45 +/- 19 bpm) but also in SBP values (a dagger SBP = -22 +/- 10 mmHg) compared to the DIO rats (a dagger SBP = 14 +/- 8 mmHg). Our findings provide evidence that the beneficial effects of sleeve gastrectomy on blood pressure values are beyond weight loss in rats with diet-induced obesity.
Autores: Pulido, M. R.; Rabanal-Ruiz, Y.; Almabouada, F.; et al.
Revista: JOURNAL OF MOLECULAR ENDOCRINOLOGY
ISSN 0952-5041  Vol. 50  Nº 1  2012  págs. 19 - 29
There is increasing evidence that proteins associated with lipid droplets (LDs) play a key role in the coordination of lipid storage and mobilization in adipocytes. The small GTPase, RAB18, has been recently identified as a novel component of the protein coat of LDs and proposed to play a role in both ß-adrenergic stimulation of lipolysis and insulin-induced lipogenesis in 3T3-L1 adipocytes. In order to better understand the role of Rab18 in the regulation of lipid metabolism in adipocytes, we evaluated the effects of age, fat location, metabolic status, and hormonal milieu on Rab18 expression in rodent white adipose tissue (WAT). Rab18 mRNA was undetectable at postnatal day 15 (P15), but reached adult levels by P45, in both male and female rats. In adult rats, Rab18 immunolocalized around LDs, as well as within the cytoplasm of mature adipocytes. A weak Rab18 signal was also detected in the stromal-vascular fraction of WAT. In mice, fasting significantly increased, though with a distinct time-course pattern, Rab18 mRNA and protein levels in visceral and subcutaneous WAT. The expression of Rab18 was also increased in visceral and subcutaneous WAT of obese mice (diet-induced, ob/ob, and New Zealand obese mice) compared with lean controls. Rab18 expression in rats was unaltered by castration, adrenalectomy, or GH deficiency but was increased by hypophysectomy, as well as hypothyroidism. When viewed together, our results suggest the participation of Rab18 in the regulation of lipid processing in adipose tissue under both normal and pathological conditions.
Autores: Martín, Marina; Burrell, María Ángela; Gómez-Ambrosi, J; et al.
Revista: OBESITY SURGERY
ISSN 0960-8923  Vol. 22  Nº 4  2012  págs. 634 - 640
Background: Sleeve gastrectomy (SG) has been used as a multipurpose surgical procedure for the treatment of morbid obesity. The aim of the study was to analyze gastric morphology and histology at two different time points after SG in rats. Methods: Thirty-five male Wistar rats were fed ad libitum during 3 months on a high-fat diet to induce obesity. Subsequently, 25 diet-induced obese rats underwent either SG (n=12) or a sham operation (n=13). The remaining ten obese animals encompassed the nonoperated control group (Co). Four weeks postoperatively, 15 rats (n05 rats/experimental group) were sacrificed, while the remaining 20 rats were sacrificed after 16 weeks (animals/group; Co=5, sham=8, SG=7) to compare the gastric morphological and histopathological changes over time. Body weight and food intake were regularly recorded. Results: For both time periods, the Co groups exhibited the highest body weight, while the rats undergoing the SG showed the lowest weight gain (P<0.05). Initially, significant differences (P<0.005) in food intake relative to body weight were observed between the Co rats and animals undergoing surgery, which disappeared thereafter. The actual total stomach sizeafter both experimental periods in the SG group was similar to that of non- and sham-operated rats mainly due to a forestomach enlargement, which was more pronounced after 16 weeks. Traits of gastritis cystica profunda characterized by gastric foveolae elongation with hyperplasia and cystic dilatation of the glandswere observed in the residual stomachs of the sleeve-gastrectomized rats. These findings were mostly observed after 16 weeks of performing the SG, although they were also detected occasionally following 4 weeks postoperatively. No intestinal metaplasia was observed. Conclusion: After SG gastric macro- and microscopic changes with functional implications in both the short and long term take place.
Autores: Rodríguez, Amaia; Becerril, Sara; Valentí, Víctor; et al.
Revista: OBESITY SURGERY
ISSN 0960-8923  Vol. 22  Nº 2  2012  págs. 309-315
Sleeve gastrectomy constitutes an effective surgical procedure for the treatment of morbid obesity in humans and rodents with diet-induced obesity. The aim of the present study was to establish the effects of sleeve gastrectomy on weight loss and cardiovascular parameters in genetically obese (fa/fa) Zucker rats. Eleven-week-old male obese (fa/fa) (n = 20) Zucker rats were assigned to three alternative procedures (sham operation, sleeve gastrectomy, or pair-fed to the amount of food eaten by sleeve-gastrectomized animals) and compared with lean Zucker (Fa/Fa) rats (n = 9). Systolic (SBP), diastolic (DBP), and mean (MBP) blood pressure values as well as heart rate (HR) were recorded in conscious, resting animals by non-invasive tail-cuff plethysmography before and 3 weeks after the surgical interventions. Sleeve-gastrectomized rats experienced a reduction in body weight (P < 0.01), total adiposity amounts (P < 0.001), together with an increased excess weight loss (%EWL) (P < 0.05) compared with sham-operated and pair-fed animals 3 weeks after the surgical interventions. Rats with sleeve gastrectomy exhibited reduced (P < 0.01) blood pressure values (Delta SBP = -11 +/- 8 mmHg; Delta DBP = -6 +/- 4 mmHg; Delta MBP = -8 +/- 6 mmHg) compared with the control group, but no changes were observed in HR (P = 0.560). Sham-operated and pair-fed groups did not alter their cardiovascular variables. Our findings provide evidence of the beneficial effects of sleeve gastrectomy on blood pressure values in addition to the weight loss in obese (fa/fa) Zucker rats independently of surgical trauma and food intake reduction.
Autores: Rodríguez, Amaia; Catalán, V; Gómez-Ambrosi, J; et al.
Revista: JOURNAL OF CLINICAL ENDOCRINOLOGY AND METABOLISM
ISSN 0021-972X  Vol. 96  Nº 4  2011  págs. 586 - 597
Autores: Valentí, Víctor; Martín, Marina; BEa; et al.
Revista: OBESITY SURGERY
ISSN 0960-8923  Vol. 21  Nº 9  2011  págs. 1438 - 1443
Background: Sleeve gastrectomy (SG) has been used for the surgical treatment of morbid obesity as a first or definitive procedure with satisfactory results. The objective of this study in rats was to establish the effects of SG on weight loss depending on the post-surgical type of diet followed. Methods: Thirty male Wistar rats were fed ad libitum during 3 months on a high-fat diet (HFD) to induce obesity. After this first phase, rats were subdivided in three groups of ten rats each and underwent a sham intervention, an SG, or no surgery but were pair-fed to the amount of food eaten by the animals of the SG group. At this time point, half of the animals in each group continued to be fed on the HFD, while the other half was switched to a normal chow diet (ND). Thus, the following subgroups were established: sham-ND, sleeve-ND, pair-fed-ND as well as sham-HFD, sleeve-HFD, and pair-fed-HFD. Body weight and food intake were recorded daily for 4 weeks. The feed efficiency rate (FER) was determined from weekly weight gains and caloric consumption during this period. Results: Statistically significant (P¿<¿0.05) differences in body weight were observed between the six experimental groups after 4 weeks of the interventions with rats in the sleeve-ND group experimenting the highest weight loss (-78.2¿±¿10.3 g) and animals in the pair-fed-HFD group exhibiting the lowest weight reduction (-4.0¿±¿0.1 g). Interestingly, the FER value of rats that underwent the SG and continued to be fed on a HFD was significantly (P¿<¿0.05) lower than that of sham operated and pair-fed animals on the same diet. Conclusion: The positive effects of SG on weight reduction are observed in obese rats submitted to the intervention and subsequently following an ND or even an HFD.
Autores: Mendieta-Zeron, H.; Larrad-Jimenez, A.; Burrell, María Ángela; et al.
Revista: DIABETES & METABOLIC SYNDROME
ISSN 1878-0334  Vol. 5  Nº 2  2011  págs. 66 - 70
INTRODUCTION: Factors leading to weight loss and weight stabilization after bariatric surgery are not fully understood. Our aim was to evaluate, in Sprague-Dawley rats, the histological and gut hormonal changes after Larrad-biliopancreatic diversion (Larrad-BPD). MATERIALS AND METHODS: Rats randomly underwent the following protocols: Larrad-BPD (n=4) versus pair fed (PF) (n=4). Weight and food intake were measured every day. By immunohistochemistry ghrelin was examined in the stomach, while cholecystokinin (CCK), glucagon-like-peptide-1 (GLP-1), peptide YY (PYY) and serotonin (5-HT) expression were analyzed in alimentary limb and ileum following or not the Larrad-BPD. RESULTS: Larrad-BPD rats exhibited significant (P<0.05) weight loss compared to PF rats. Villi enlongation was observed in Larrad-BPD rats. In residual stomach, ghrelin was diminished. In the alimentary limb, ghrelin and CCK positive cells were detected more than in the ileum of PF rats. GLP-1 expression was decreased and PYY expression was absent after Larrad-BPD compared with PF rats. DISCUSSION: Larrad-BPD is followed by histological changes and a pleiotropic gut endocrine response aimed to compensate the reduction of intestinal area exposed to food. Until now, the hormones responsible for the intestinal hypertrophy have not been defined.
Autores: Burrell, María Ángela; Calvo, Alfonso;
Libro:  Biología celular biomédica
2015  págs. 219 - 241
Autores: Burrell, María Ángela; Vázquez, R.; Malagon, M. M.; et al.
Libro:  Técnicas en histología y biología celular
2014  págs. 265 - 276