Berasain, C. (Carmen)

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    Up-regulation of the anti-inflammatory adipokine adiponectin in acute liver failure in mice
    (Elsevier, 2006) Wolf, D. (Dominik); Wolf, A.M. (Anna María); Rumpold, H. (Holger); Berasain, C. (Carmen); Moschen, A.R. (Alexander R.); Enrich, B. (Barbara); Avila, M.A. (Matías Antonio); Tilg, H. (Herbert)
    BACKGROUND/AIMS: Recent reports suggest that the adipose tissue and adipokines are potent modulators of inflammation. However, there is only scarce knowledge on the functional role and regulation of endogenous adiponectin in non-fat tissues such as the liver under conditions of acute inflammation. METHODS: In the present study, we investigated adiponectin expression in healthy murine liver tissue and under inflammatory conditions in vivo. RESULTS: Adiponectin mRNA was readily detectable in healthy liver tissue and further increased in ConA-mediated acute liver failure. Adiponectin protein expression was mainly found in hepatic endothelial cells. In vitro adiponectin mRNA expression was detectable in several cell types, including primary hepatic sinusoidal endothelial cells, stellate cells, and macrophages. Mice pretreated with adiponectin before ConA administration developed reduced hepatic injury as shown by decreased release of transaminases and reduced hepatocellular apoptotis. Of note, TNF-alpha levels were not affected by adiponectin, whereas IL-10 production was increased. Neutralisation of IL-10 diminished the protective effect of adiponectin. CONCLUSIONS: Adiponectin expression is up-regulated in ConA-mediated acute liver failure. Therefore, adiponectin might play a role in the control and limitation of inflammation in the liver. Moreover, our data suggest a role for IL-10 in adiponectin-mediated hepatoprotection.
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    Amphiregulin: an early trigger of liver regeneration in mice
    (Elsevier, 2005) Berasain, C. (Carmen); Avila, M.A. (Matías Antonio); Erroba, E. (Elena); Castillo, J. (Josefa); Ruiz Garcia-Trevijano, E. (Elena); Prieto, J. (Jesús); Lee, D.C. (David C.)
    BACKGROUND AND AIMS: Liver regeneration is a unique response directed to restore liver mass after resection or injury. The survival and proliferative signals triggered during this process are conveyed by a complex network of cytokines and growth factors acting in an orderly manner. Activation of the epidermal growth factor receptor is thought to play an important role in liver regeneration. Amphiregulin is a member of the epidermal growth factor family whose expression is not detectable in healthy liver. We have investigated the expression of amphiregulin in liver injury and its role during liver regeneration after partial hepatectomy. METHODS: Amphiregulin gene expression was examined in healthy and cirrhotic human and rat liver, in rodent liver regeneration after partial hepatectomy, and in primary hepatocytes. The proliferative effects and intracellular signaling of amphiregulin were studied in isolated hepatocytes. The in vivo role of amphiregulin in liver regeneration after partial hepatectomy was analyzed in amphiregulin-null mice. RESULTS: Amphiregulin gene expression is detected in chronically injured human and rat liver and is rapidly induced after partial hepatectomy in rodents. Amphiregulin expression is induced in isolated hepatocytes by interleukin 1beta and prostaglandin E(2), but not by hepatocyte growth factor, interleukin 6, or tumor necrosis factor alpha. We show that amphiregulin behaves as a primary mitogen for isolated hepatocytes, acting through the epidermal growth factor receptor. Finally, amphiregulin-null mice display impaired proliferative responses after partial liver resection. CONCLUSIONS: Our findings indicate that amphiregulin is an early-response growth factor that may contribute to the initial phases of liver regeneration.
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    Expression of Wilms' tumor suppressor in the liver with cirrhosis: relation to hepatocyte nuclear factor 4 and hepatocellular function
    (Wiley-Blackwell, 2003) Berasain, C. (Carmen); Avila, M.A. (Matías Antonio); Esteban, J.I. (Juan Ignacio); Ruiz Garcia-Trevijano, E. (Elena); Prieto, J. (Jesús); Herrero, J.I. (José Ignacio); Mato, J.M. (José María)
    The Wilms' tumor suppressor WT1 is a transcriptional regulator present in the fetal but not in the mature liver. Its expression and functional role in liver diseases remains unexplored. In this study, we analyzed WT1 expression by reverse-transcription polymerase chain reaction (RT-PCR) and by immunohistochemistry in normal and diseased livers. In addition, we performed in vitro studies in isolated rat hepatocytes to investigate WT1 regulation and function. We detected WT1 messenger RNA (mRNA) in 18% of normal livers, 17% of chronic hepatitis with minimal fibrosis, 49% of chronic hepatitis with bridging fibrosis, and 71% of cirrhotic livers. In cirrhosis, WT1 immunoreactivity was localized to the nucleus of hepatocytes. WT1 mRNA abundance correlated inversely with prothrombin time (P =.04) and directly with serum bilirubin (P =.002) and with the MELD score (P =.001) of disease severity. In rats, WT1 expression was present in fetal hepatocytes and in the cirrhotic liver but not in normal hepatic tissue. In vitro studies showed that isolated primary hepatocytes express WT1 when stimulated with transforming growth factor beta (TGF-beta) or when the cells undergo dedifferentiation in culture. Moreover, we found that WT1 down-regulates hepatocyte nuclear factor 4 (HNF-4), a factor that is essential to maintain liver function and metabolic regulation in the mature organ. Hepatic expression of HNF-4 was impaired in advanced human cirrhosis and negatively correlated with WT1 mRNA levels (P =.001). In conclusion, we show that WT1 is induced by TGF-beta and down-regulates HNF-4 in liver cells. WT1 is reexpressed in the cirrhotic liver in relation to disease progression and may play a role in the development of hepatic insufficiency in cirrhosis.
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    SLU7: a new hub of gene expression regulation-from epigenetics to protein stability in health and disease
    (2022) Berasain, C. (Carmen); Arechederra, M. (María); Avila, M.A. (Matías Antonio); Recalde, M. (Miriam); Gárate-Rascón, M. (María); García-Fernández-de-Barrena, M. (Maite); Rojo-González, C. (Carla)
    SLU7 (Splicing factor synergistic lethal with U5 snRNA 7) was first identified as a splicing factor necessary for the correct selection of 3 ' splice sites, strongly impacting on the diversity of gene transcripts in a cell. More recent studies have uncovered new and non-redundant roles of SLU7 as an integrative hub of different levels of gene expression regulation, including epigenetic DNA remodeling, modulation of transcription and protein stability. Here we review those findings, the multiple factors and mechanisms implicated as well as the cellular functions affected. For instance, SLU7 is essential to secure liver differentiation, genome integrity acting at different levels and a correct cell cycle progression. Accordingly, the aberrant expression of SLU7 could be associated with human diseases including cancer, although strikingly, it is an essential survival factor for cancer cells. Finally, we discuss the implications of SLU7 in pathophysiology, with particular emphasis on the progression of liver disease and its possible role as a therapeutic target in human cancer.
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    Reduced mRNA abundance of the main enzymes involved in methionine metabolism in human liver cirrhosis and hepatocellular carcinoma
    (Elsevier, 2000) Martin-Duce, A. (Antonio); Corrales, F.J. (Fernando José); Berasain, C. (Carmen); Lu, S.C. (Shelly C.); Avila, M.A. (Matías Antonio); Rodes, J. (Juan); Prieto, J. (Jesús); Torres, L. (Luis); Caballeria, J. (Juan); Yang, H. (Heping); Mato, J.M. (José María)
    BACKGROUND/AIMS: It has been known for at least 50 years that alterations in methionine metabolism occur in human liver cirrhosis. However, the molecular basis of this alteration is not completely understood. In order to gain more insight into the mechanisms behind this condition, mRNA levels of methionine adenosyltransferase (MAT1A), glycine methyltransferase (GNMT), methionine synthase (MS), betaine homocysteine methyltransferase (BHMT) and cystathionine beta-synthase (CBS) were examined in 26 cirrhotic livers, five hepatocellular carcinoma (HCC) tissues and ten control livers. METHODS: The expression of the above-mentioned genes was determined by quantitative RT-PCR analysis. Methylation of MAT1A promoter was assessed by methylation-sensitive restriction enzyme digestion of genomic DNA. RESULTS: When compared to normal livers MAT1A, GNMT, BHMT, CBS and MS mRNA contents were significantly reduced in liver cirrhosis. Interestingly, MAT1A promoter was hypermethylated in the cirrhotic liver. HCC tissues also showed decreased mRNA levels of these enzymes. CONCLUSIONS: These findings establish that the abundance of the mRNA of the main genes involved in methionine metabolism is markedly reduced in human cirrhosis and HCC. Hypermethylation of MAT1A promoter could participate in its reduced expression in cirrhosis. These observations help to explain the hypermethioninemia, hyperhomocysteinemia and reduced hepatic glutathione content observed in cirrhosis.
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    Epigenetics in liver fibrosis: could HDACs be a therapeutic target?
    (MDPI AG, 2020) Berasain, C. (Carmen); Arechederra, M. (María); Fernández-Barrena, M.G. (Maite G.); Urman, J.M. (Jesús M.); Avila, M.A. (Matías Antonio); Colyn, L. (Leticia); Claveria-Cabello, A. (Alex)
    Chronic liver diseases (CLD) represent a worldwide health problem. While CLDs may have diverse etiologies, a common pathogenic denominator is the presence of liver fibrosis. Cirrhosis, the end-stage of CLD, is characterized by extensive fibrosis and is markedly associated with the development of hepatocellular carcinoma. The most important event in hepatic fibrogenesis is the activation of hepatic stellate cells (HSC) following liver injury. Activated HSCs acquire a myofibroblast-like phenotype becoming proliferative, fibrogenic, and contractile cells. While transient activation of HSCs is part of the physiological mechanisms of tissue repair, protracted activation of a wound healing reaction leads to organ fibrosis. The phenotypic changes of activated HSCs involve epigenetic mechanisms mediated by non-coding RNAs (ncRNA) as well as by changes in DNA methylation and histone modifications. During CLD these epigenetic mechanisms become deregulated, with alterations in the expression and activity of epigenetic modulators. Here we provide an overview of the epigenetic alterations involved in fibrogenic HSCs transdifferentiation with particular focus on histones acetylation changes. We also discuss recent studies supporting the promising therapeutic potential of histone deacetylase inhibitors in liver fibrosis.
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    Identification and experimental validation of druggable epigenetic targets in hepatoblastoma
    (Elsevier, 2023) Indersie, E. (Emilie); Latasa, M.U. (María Ujué); Berraondo, P. (Pedro); Corrales, F.J. (Fernando José); Berasain, C. (Carmen); Arechederra, M. (María); Domingo-Sàbat, M. (Montserrat); Pineda-Lucena, A. (Antonio); Sancho-Bru, P. (Pau); Zanatto, L. (Laura); Armengol, C. (Carolina); Uriarte, I. (Iker); Ciordia, S. (Sergio); Avila, M.A. (Matías Antonio); Alaggio, R. (Rita); Alonso, C. (Cristina); Sangro, B. (Bruno); García-Fernandez-Barrena, M. (Maite); Herranz, J.M. (José M.); Cairo, S. (Stefano); García-Marin, J.J. (Jose Juan); Francalanci, P. (Paola); Prosper-Cardoso, F. (Felipe); Claveria-Cabello, A. (Alex); Martinez-Chantar, M.L. (María Luz); Zucman-Rossi, J. (Jessica)
    Background & Aims: Hepatoblastoma (HB) is the most frequent childhood liver cancer. Patients with aggressive tumors have limited therapeutic options; therefore, a better understanding of HB pathogenesis is needed to improve treatment. HBs have a very low mutational burden; however, epigenetic alterations are increasingly recognized. We aimed to identify epigenetic regulators consistently dysregulated in HB and to evaluate the therapeutic efficacy of their targeting in clinically relevant models. Methods: We performed a comprehensive transcriptomic analysis of 180 epigenetic genes. Data from fetal, pediatric, adult, peritumoral (n = 72) and tumoral (n = 91) tissues were integrated. Selected epigenetic drugs were tested in HB cells. The most relevant epigenetic target identified was validated in primary HB cells, HB organoids, a patient-derived xenograft model, and a genetic mouse model. Transcriptomic, proteomic and metabolomic mechanistic analyses were performed. Results: Altered expression of genes regulating DNA methylation and histone modifications was consistently observed in association with molecular and clinical features of poor prognosis. The histone methyltransferase G9a was markedly upregulated in tumors with epigenetic and transcriptomic traits of increased malignancy. Pharmacological targeting of G9a significantly inhibited growth of HB cells, organoids and patient-derived xenografts. Development of HB induced by oncogenic forms of b-catenin and YAP1 was ablated in mice with hepatocyte-specific deletion of G9a. We observed that HBs undergo significant transcriptional rewiring in genes involved in amino acid metabolism and ribosomal biogenesis. G9a inhibition counteracted these pro-tumorigenic adaptations. Mechanistically, G9a targeting potently repressed the expression of c-MYC and ATF4, master regulators of HB metabolic reprogramming. Conclusions: HBs display a profound dysregulation of the epigenetic machinery. Pharmacological targeting of key epigenetic effectors exposes metabolic vulnerabilities that can be leveraged to improve the treatment of these patients.
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    FGF15/19 is required for adipose tissue plasticity in response to thermogenic adaptations
    (2021) Villarroya, F. (Francesc); Berasain, C. (Carmen); Uriarte, I. (Iker); Avila, M.A. (Matías Antonio); Gavaldà-Navarro, A. (Aleix); Moreno-Navarrete, J. (José); Morón-Ros, S. (Samantha); Sabater, M. (Mónica); Giralt, M. (Marta); Fernandez-Real, J.M. (José Manuel)
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    Targeting CCL2/CCR2 in tumor-infiltrating macrophages: a tool emerging out of the box against hepatocellular carcinoma
    (Elsevier BV, 2019) Berasain, C. (Carmen); Avila, M.A. (Matías Antonio)
    Hepatocellular carcinoma (HCC) is the most frequent primary liver tumor and a leading cause of cancer-related mortality. Unfortunately, the majority of HCC patients present with advanced disease, when locoregional curative strategies are no longer applicable. On the other hand, early, HCCs proved to be resistant to conventional chemotherapies, and drugs targeting specific growth factor signaling pathways tested over the past decade have not succeeded in clinical trials. The molecular heterogeneity of HCCs and the lack of biomarker-based patient stratification strategies may underlie the failure of most of these trials. HCCs usually develop on a background of chronic liver injury and regeneration, inflammation, and fibrosis, features that promote tumor hypervascularity, the other histologic hallmark of this neoplasia. Indeed, the fibrotic and immune microenvironment plays a key role in pathogenic angiogenesis and HCC development and progression. This tenet is supported not only by experimental evidence, but also by the fact that the only therapeutic agents showing clinical efficacy in advanced HCC are those directed toward the interaction of HCC with its microenvironment (ie, anti-angiogenic multikinase inhibitors such as sorafenib, and immune checkpoint inhibitors such as antibodies targeting programmed cell death receptor 1 and its ligand).
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    Activation of the unfolded protein response (UPR) is associated with cholangiocellular injury, fibrosis and carcinogenesis in an experimental model of fibropolycystic liver disease
    (2022) Latasa, M.U. (María Ujué); Bañares, R. (Rafael); Berasain, C. (Carmen); Arechederra, M. (María); Fernández-Barrena, M.G. (Maite G.); Nevzorova, Y. (Yulia); Peligros, M.I. (María Isabel); Nelson, L.J. (Leonard J.); Avila, M.A. (Matías Antonio); Davis, R.J. (Roger J.); Tortajada, A. (Agustín); Wu, H. (Hanghang); Vidal, A. (August); Rodriguez-Perales, S. (Sandra); Ye, H. (Hui); Reissing, J. (Johanna); Mohamed, M.R. (Mohamed Ramadan); Iraburu-Elizalde, M. (María); Lujambio, A. (Amaya); Martínez-Naves, E. (Eduardo); Trautwein, C. (Christian); Villanueva, A. (Alberto); Vaquero, J. (Javier); Colyn, L. (Leticia); Torres-Ruiz, R. (Raúl); Zheng, K. (Kang); Bruns, T. (Tony); Cubero, F.J. (Francisco Javier); Chen, C. (Chaobo)
    Polycystic liver disease (PLD) is a group of rare disorders that result from structural changes in the biliary tree development in the liver. In the present work, we studied alterations in molecular mechanisms and signaling pathways that might be responsible for these pathologies. We found that activation of the unfolded protein response, a process that occurs in response to an accumulation of unfolded or misfolded proteins in the lumen of the endoplasmic reticulum, as well as the scarring of the liver tissue, contribute to the pathogenesis of PLD and the development of cancer. As a preclinical animal model we have used mutant mice of a specific signaling pathway, the c-Jun N-terminal kinase 1/2 (Jnk1/2). These mice resemble a perfect model for the study of PLD and early cancer development.