Bruno Cogliati

University of São Paulo, San Paulo, São Paulo, Brazil

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Publications (55)147.14 Total impact

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    ABSTRACT: Non-alcoholic fatty liver disease encompasses a spectrum of liver diseases, including simple steatosis, steatohepatitis, liver fibrosis and cirrhosis and hepatocellular carcinoma. Non-alcoholic fatty liver disease is currently the most dominant chronic liver disease in Western countries due to the fact that hepatic steatosis is associated with insulin resistance, type 2 diabetes mellitus, obesity, metabolic syndrome and drug-induced injury. A variety of chemicals, mainly drugs, and diets is known to cause hepatic steatosis in humans and rodents. Experimental non-alcoholic fatty liver disease models rely on the application of a diet or the administration of drugs to laboratory animals or the exposure of hepatic cell lines to these drugs. More recently, genetically modified rodents or zebrafish have been introduced as non-alcoholic fatty liver disease models. Considerable interest now lies in the discovery and development of novel non-invasive biomarkers of non-alcoholic fatty liver disease, with specific focus on hepatic steatosis. Experimental diagnostic biomarkers of non-alcoholic fatty liver disease, such as (epi)genetic parameters and '-omics'-based read-outs are still in their infancy, but show great promise.. In this paper, the array of tools and models for the study of liver steatosis is discussed. Furthermore, the current state-of-art regarding experimental biomarkers such as epigenetic, genetic, transcriptomic, proteomic and metabonomic biomarkers will be reviewed. Copyright © 2015. Published by Elsevier Ltd.
    Progress in Lipid Research 07/2015; 59:106-125. DOI:10.1016/j.plipres.2015.05.002 · 12.96 Impact Factor
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    ABSTRACT: Connexin proteins are abundantly present in the digestive system. They primarily form gap junctions, which control the intercellular exchange of critical homeostasis regulators. By doing so, gap junctions drive a plethora of gastrointestinal and hepatic functional features, including gastric and gut motility, gastric acid secretion, intestinal innate immune defense, xenobiotic biotransformation, glycogenolysis, bile secretion, ammonia detoxification and plasma protein synthesis. In the last decade, it has become clear that connexin hemichannels, which are the structural precursors of gap junctions, also provide a pathway for cellular communication, namely between the cytosol and the extracellular environment. Although merely pathological functions have been described, some physiological roles have been attributed to connexin hemichannels, in particular in the modulation of colonic motility. This equally holds true for cellular channels composed of pannexins, connexin-like proteins recently identified in the intestine and the liver, which have become acknowledged key players in inflammatory processes and that have been proposed to control colonic motility, secretion and blood flow.
    Cellular and Molecular Life Sciences CMLS 06/2015; DOI:10.1007/s00018-015-1961-8 · 5.86 Impact Factor
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    ABSTRACT: Hepatic fibrosis is a wound healing response to insults and as such affects the entire world population. In industrialized countries, the main causes of liver fibrosis include alcohol abuse, chronic hepatitis virus infection and non-alcoholic steatohepatitis. A central event in liver fibrosis is the activation of hepatic stellate cells, which is triggered by a plethora of signaling pathways. Liver fibrosis can progress into more severe stages, known as cirrhosis, when liver acini are substituted by nodules, and further to hepatocellular carcinoma. Considerable efforts are currently devoted to liver fibrosis research, not only with the goal of further elucidating the molecular mechanisms that drive this disease, but equally in view of establishing effective diagnostic and therapeutic strategies. The present paper provides a state-of-the-art overview of in vivo and in vitro models used in the field of experimental liver fibrosis research.
    Archives of Toxicology 06/2015; DOI:10.1007/s00204-015-1543-4 · 5.08 Impact Factor
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    ABSTRACT: & aims: Few clinical trials have addressed the potential benefits of omega-3 polyunsaturated fatty acids (PUFAs) on non-alcoholic steatohepatitis (NASH). We evaluated the effects of supplementation with omega-3 PUFAs from flaxseed and fish oils in patients with biopsy-proven NASH. Patients received three capsules daily, each containing 0.315 g of omega-3 PUFAs (64% alpha-linolenic [ALA], 16% eicosapentaenoic [EPA], and 21% docosahexaenoic [DHA] acids; n-3 group, n = 27) or mineral oil (placebo group, n = 23). Liver biopsies were evaluated histopathologically by the NASH activity score (NAS). Plasma levels of omega-3 PUFAs were assessed as a marker of intake at baseline and after 6 months of treatment. Secondary endpoints included changes in plasma biochemical markers of lipid metabolism, inflammation, and liver function at baseline and after 3 and 6 months of treatment. At baseline, NAS was comparable between the groups (p = 0.98). After intervention with omega-3 PUFAs, plasma ALA and EPA levels increased (p ≤ 0.05). However in the placebo group, we also observed increased EPA and DHA (p ≤ 0.05), suggesting an off-protocol intake of PUFAs. NAS improvement/stabilization was correlated with increased ALA in the n-3 group (p = 0.02) and with increased EPA (p = 0.04) and DHA (p = 0.05) in the placebo group. Triglycerides were reduced after 3 months in the n-3 group compared to baseline (p = 0.01). In NASH patients, the supplementation of omega-3 PUFA from flaxseed and fish oils significantly impacts on plasma lipid profile of patients with NASH. Plasma increase of these PUFAs was associated with better liver histology. (ID 01992809). Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
    Clinical nutrition (Edinburgh, Scotland) 05/2015; DOI:10.1016/j.clnu.2015.05.001 · 3.94 Impact Factor
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    ABSTRACT: Gap junctions, which mediate intercellular communication, are key players in digestive homeostasis. They are also frequently involved in gastrointestinal and liver pathology. This equally holds true for connexin (Cx) hemichannels, the structural precursors of gap junctions, and pannexin (Panx) channels, Cx-like proteins assembled in a hemichannel configuration. Both Cx hemichannels and Panx channels facilitate extracellular communication and drive a number of deteriorative processes, such as cell death and inflammation. Cxs, Panxs, and their channels underlie a wide spectrum of gastrointestinal and liver diseases, including gastritis and peptic ulcer disease, inflammatory intestinal conditions, acute liver failure, cholestasis, hepatitis and steatosis, liver fibrosis and cirrhosis, infectious gastrointestinal pathologies, and gastrointestinal and liver cancer. This could open promising perspectives for the characterization of new targets and biomarkers for therapeutic and diagnostic clinical purposes in the area of gastroenterology and hepatology. Copyright © 2015 Elsevier Inc. All rights reserved.
    Translational Research 05/2015; DOI:10.1016/j.trsl.2015.05.005 · 4.04 Impact Factor
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    ABSTRACT: Hebanthe paniculata roots (formerly Pfaffia paniculata and popularly known as Brazilian ginseng) show antineoplastic, chemopreventive, and antiproliferative properties. Functional properties of these roots and their extracts are usually attributed to the pfaffosidic fraction, which is composed mainly by pfaffosides A-F. However, the therapeutic potential of this fraction in cancer cells is not yet entirely understood. This study aimed to analyze the antitumoral effects of the purified pfaffosidic fraction or saponinic fraction on the human hepatocellular carcinoma HepG2 cell line. Cellular viability, proliferation, and apoptosis were evaluated, respectively, by MTT assay, BrdU incorporation, activated caspase-3 immunocytochemistry, and DNA fragmentation assay. Cell cycle was analyzed by flow cytometry and the cell cycle-related proteins were analyzed by quantitative PCR and Western blot. The cells exposed to pfaffosidic fraction had reduced viability and cellular growth, induced G2/M at 48 h or S at 72 h arrest, and increased sub-G1 cell population via cyclin E downregulation, p27(KIP1) overexpression, and caspase-3-induced apoptosis, without affecting the DNA integrity. Antitumoral effects of pfaffosidic fraction from H. paniculata in HepG2 cells originated by multimechanisms of action might be associated with cell cycle arrest in the S phase, by CDK2 and cyclin E downregulation and p27(KIP1) overexpression, besides induction of apoptosis through caspase-3 activation.
    Evidence-based Complementary and Alternative Medicine 05/2015; 2015:1-9. DOI:10.1155/2015/835796 · 1.88 Impact Factor
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    ABSTRACT: Cellular channels composed of connexin 43 are known to act as key players in the life cycle of the skin and consequently to underlie skin repair. This study was specifically set up to investigate the suite of molecular mechanisms driven by connexin 43-based channels on wound healing. To this end, a battery of parameters, including re-epithelialization, neovascularization, collagen deposition and extracellular matrix remodeling, was monitored over time during experimentally induced skin repair in heterozygous connexin 43 knockout mice. It was found that connexin 43 deficiency accelerates re-epithelialization and wound closure, increases proliferation and activation of dermal fibroblasts, and enhances the expression of extracellular matrix remodeling mediators. These data substantiate the notion that connexin 43 may represent an interesting therapeutic target in dermal wound healing. Copyright © 2015 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.
    Journal of dermatological science 04/2015; 79(1). DOI:10.1016/j.jdermsci.2015.03.019 · 3.34 Impact Factor
  • Journal of Hepatology 04/2015; 62:S691. DOI:10.1016/S0168-8278(15)31125-9 · 10.40 Impact Factor
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    ABSTRACT: Background and Aims: Pannexins (Panx) constitute a relatively new family of transmembrane proteins that form channels linking the cytoplasmic compartment with the extracellular environment. The pannexin family consists of 3 members of which Panx1 is expressed in the liver. It is well-known that Panx1 plays a key role in innate immunity by facilitating activation of the inflammasome. Recently, Panx1-mediated inflammation was found to be involved in non-alcoholic steatohepatitis in mouse. In the present study, it is investigated whether this also holds true for acute liver failure in casu triggered by acetaminophen. Methods: Mice were overdosed with acetaminophen followed by treatment with the Panx1 channel inhibitor 10Panx1 after 1.5 hours. Sampling was performed 24 hours after acetaminophen administration. Evaluation of the effect of Panx1 channel inhibition was based on a number of clinically relevant read-outs, including assessment of alanine and aspartate aminotransferase serum levels as well as histopathological examination of liver tissue with quantification of cell death. Inflammation was studied by measurement of cytokine levels in liver and serum. Results: All parameters measured indicate a significant reduction of liver damage, including cell death and inflammation, upon treatment of acetaminophen-intoxicated mice with 10Panx1. Conclusions: The results of this study demonstrate the clinical potential of Panx1 channel inhibition as a therapeutic strategy in the treatment of acetaminophen-induced acute liver failure.
    Journal of Hepatology 04/2015; 62:S329. DOI:10.1016/S0168-8278(15)30301-9 · 10.40 Impact Factor
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    ABSTRACT: Liver fibrosis occurring as an outcome of non-alcoholic steatohepatitis (NASH) can precede the development of cirrhosis. We investigated the effects of sorafenib in preventing liver fibrosis in a rodent model of NASH. Adult Sprague-Dawley rats were fed a choline-deficient high-fat diet and exposed to diethylnitrosamine for 6 weeks. The NASH group (n=10) received vehicle and the sorafenib group (n=10) received 2.5 mg·kg-1·day-1 by gavage. A control group (n=4) received only standard diet and vehicle. Following treatment, animals were sacrificed and liver tissue was collected for histologic examination, mRNA isolation, and analysis of mitochondrial function. Genes related to fibrosis (MMP9, TIMP1, TIMP2), oxidative stress (HSP60, HSP90, GST), and mitochondrial biogenesis (PGC1α) were evaluated by real-time quantitative polymerase chain reaction (RT-qPCR). Liver mitochondrial oxidation activity was measured by a polarographic method, and cytokines by enzyme-linked immunosorbent assay (ELISA). Sorafenib treatment restored mitochondrial function and reduced collagen deposition by nearly 63% compared to the NASH group. Sorafenib upregulated PGC1α and MMP9 and reduced TIMP1 and TIMP2 mRNA and IL-6 and IL-10 protein expression. There were no differences in HSP60, HSP90 and GST expression. Sorafenib modulated PGC1α expression, improved mitochondrial respiration and prevented collagen deposition. It may, therefore, be useful in the treatment of liver fibrosis in NASH.
    Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas / Sociedade Brasileira de Biofisica ... [et al.] 02/2015; DOI:10.1590/1414-431X20143962 · 1.08 Impact Factor
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    ABSTRACT: Hepatotoxicity, including drug-induced liver injury, is frequently accompanied by cell death. The latter is typically driven by apoptosis or necrosis, which substantially differ based upon biochemical and morpho- logical criteria. This chapter describes two commonly used methods to probe apoptotic and necrotic activi- ties in adherent monolayer cultures of primary hepatocytes. The apoptosis assay uses a prototypical substrate of caspase 3, the main executor of apoptotic cell death, which can be cleaved, yielding a product that can be measured fl uorimetrically. The second assay relies on the disruption of the cell plasma mem- brane, which typically occurs in necrotic cell death and that results in the extracellular release of cytoplas- mic enzymes, such as lactate dehydrogenase. The latter can be indirectly assessed by spectrophotometrically measuring the consumption of reduced nicotinamide adenine dinucleotide.
    Protocols in In Vitro Hepatocyte Research, 2015 edited by Mathieu Vinken, Vera Rogiers, 01/2015: chapter Measurement of Apoptotic and Necrotic Cell Death in Primary Hepatocyte Cultures: pages 349-362; Springer Protocols-Humana Press., ISBN: 978-1-4939-2073-0
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    ABSTRACT: Connexins are proteins that form gap junctions. Perturbations in the cell membrane reportedly promote changes in the expression profile of connexins. Electroporation promotes destabilization by applying electrical pulses, and this procedure is used in electrochemotherapy and gene therapy, among others. This in vitro work aimed to study the interference of electroporation on the expression profile of GJB2 (Cx26 gene) and Connexin 26 in melanoma cell line B16/BL6. The techniques of immunocytochemistry, Western blot, and real-time PCR were used. After electroporation, cells showed a transient decrease in GJB2 mRNA. The immunostaining of Cx26 showed no noticeable change after electroporation at different time points. However, Western blot showed a significant reduction in Cx26 30 min after electroporation. Our results showed that electroporation interferes transiently in the expression of Connexin 26 in melanoma and are consistent with the idea that electroporation is a process of intense stress that promotes cell homeostatic imbalance and results in disruption of cell physiological processes such as transcription and translation.
    Journal of Membrane Biology 10/2014; 248(1). DOI:10.1007/s00232-014-9735-z · 2.17 Impact Factor
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    ABSTRACT: Background: Very few studies have evaluated the expression of homeobox A10 (HOXA10) and steroid (estrogen and progesterone) receptors exclusively in deep endometriosis. Conclusions drawn from studies evaluating peritoneal and ovarian endometriosis are usually generalized to explain the pathogenesis of the disease as a whole. We aimed to evaluate the expression of HOXA10, estrogen receptor (ER-), progesterone receptor (PR), and PR-B in rectosigmoid endometriosis (RE), a typical model of deep disease. Methods: We used RE samples from 18 consecutive patients to construct tissue microarray blocks. Nine patients each were operated during the proliferative and secretory phases of the menstrual cycle. We quantified the expressions of proteins by immunohistochemistry using the modified Allred score. Result: The HOXA10 was expressed in the stroma of nodules during the secretory phase in 5 of the 18 patients. Expression of ER- (in 16 of 18 patients), PR (in 17 of 18 patients), and PR-B (17 of 18 patients) was moderate to strong in the glands and stroma of nodules during both phases. Expression of both PR (P = .023) and PR-B (P = .024) was significantly greater during the secretory phase. Conclusion: The HOXA10 is expressed in RE, where it likely imparts the de novo identity of endometriotic lesions. The ER-, PR, and PR-B are strongly expressed in RE, which differs from previous studies investigating peritoneal and ovarian lesions. This suggests different routes of pathogenesis for each of the 3 types of endometriosis.
    Reproductive sciences (Thousand Oaks, Calif.) 09/2014; 22(1). DOI:10.1177/1933719114549846 · 2.18 Impact Factor
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    ABSTRACT: Background: Melanoma is one of the most common skin neoplasms in humans and dogs. The tumor microenvironment in melanoma comprises cancer cells and stromal cells that interact to accelerate tumor progression. Several prognostic markers for melanomas have been studied in many human tumors, including fibroblast-specific protein 1 (S100A4). S100A4 is a member of the S100 family of calcium-binding proteins in stromal cells.Hypothesis/objectives: The objective of this study was to describe the immunohistochemical patterns of S100A4 in stroma and neoplastic cells of canine skin melanomas and correlate them with some histological parameters. Animals and Methods: Forty-eight samples (38 pigmented and 10 non-pigmented melanomas) were first selected and their nature confirmed using S100, Melan A and vimentin. All cases were examined by immunohistochemistry using S100A4 to correlate expression, histotype, and level of invasion.Results: All the tumors, including 10 non-pigmented, were positive for S100, Melan A, vimentin and negative for cytokeratin AE1/AE3 (consistent with melanomas). The 48 melanomas were classified as epithelioid (n = 21), spindle (n = 14), and mixed (n = 13). S100A4 was preferentially expressed in epithelioid and spindle cell types compared with mixed melanomas and S100A4 expression was not associated with level of invasion (Clark's levels IV to V).Conclusion: S100A4 expression in melanoma samples varied among histotypes but not between levels of invasion.
    The Veterinary quarterly 07/2014; 34(2):1-7. DOI:10.1080/01652176.2014.936628 · 0.65 Impact Factor
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    ABSTRACT: Lung cancer is the leading cause of cancer-related mortality in both men and women throughout the world. This disease is strongly associated with tobacco smoking. The aim of this manuscript was to establish an in vitro model that mimics the chronic exposures of alveolar epithelial type II cells to the tobacco-specific nitrosamine carcinogen, NNK. Immortalized non-neoplastic alveolar epithelial cells type II, (E10 cells), from BALB/c mice were exposed to low concentration of NNK (100 pM) during 5, 10, 15, and 20 cycles of 48 h. NNK-transformed cells showed an increase of proliferation rate and motility. Moreover, these cells underwent epithelial-to-mesenchymal transition (EMT). Increased migratory capacity and EMT were correlated to the time of exposure to NNK. NNK-transformed cells were tested for their growth and metastatic capacity in vivo. Subcutaneous injection of cells exposed to NNK for 20 cycles (E10-NNK20 clone) into BALB/c mice led to the formation of subcutaneous tumors that arose after 40 ± 17 d in all animals, which died 95 ± 18 d after cell inoculation, with lymph nodes and lung metastasis. The morphological characteristics of tumors were compatible with metastatic undifferentiated carcinoma. Cells exposed to NNK for 5-10 cycles did not display metastatic capacity, while those exposed for 15 cycles displayed low capacity. Our results show that prolonged exposures to NNK led the cells to increasingly acquire malignant properties. The cellular model presented in this study is suitable for studying the molecular events involved in the different stages of malignant transformation. © 2012 Wiley Periodicals, Inc.
    Molecular Carcinogenesis 05/2014; 53(5). DOI:10.1002/mc.21987 · 4.77 Impact Factor
  • Journal of Hepatology 04/2014; 60(1):S152. DOI:10.1016/S0168-8278(14)60424-4 · 10.40 Impact Factor
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    ABSTRACT: Rationale: The excessive intake of vitamin A in the form of vitamin concentrate, supplement or vitamin-rich liver can result in hypervitaminosis A in man and animals. Although osteopathologies resulting from chronic vitamin A intoxication in cats are well characterized, no information is available concerning feline hypervitaminosis A-induced liver disease. Clinical summary: We report the first case of hepatic stellate cell lipidosis and hepatic fibrosis in a domestic cat that had been fed a diet based on raw beef liver. Radiographic examination revealed exostoses and ankylosis between vertebrae C1 and T7, compatible with deforming cervical spondylosis. Necropsy showed a slightly enlarged and light yellow to bronze liver. Microscopic and ultrastructural analyses of liver tissues revealed diffuse and severe liver fibrosis associated with hepatic stellate cell hyperplasia and hypertrophy. These cells showed immunopositive staining for α-smooth muscle actin and desmin markers. The necropsy findings of chronic liver disease coupled with osteopathology supported the diagnosis of hypervitaminosis A. Practical relevance: As in human hepatology, if there is dietary evidence to support increased intake of vitamin A, then hypervitaminosis A should be considered in the differential diagnosis of chronic liver disease in cats.
    03/2014; 16(3):243-8. DOI:10.1177/1098612X13516121
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    ABSTRACT: Hair follicle tumours generally present as benign, solitary masses and have a good prognosis following surgical resection. This report describes a case of multiple trichoblastomas in a dog. A 2-year-old crossbred dog presented with multiple soft cutaneous periocular, perilabial, submandibular and nasal nodules, between 2 and 9 cm in diameter, located on the right side of the face. New nodules were observed on the same side of the face at a second consultation 3 weeks later. Surgical resection of all nodules was performed in two procedures. Three nodules were initially resected and submitted for histolopathology and immunohistochemistry. The diagnosis was trichoblastoma for all three. At the time of the second consultation, new and remaining nodules were biopsied and the diagnosis of trichoblastoma confirmed. The dog was treated with doxorubicin and piroxicam for 30 days prior to the second surgical procedure in an attempt to reduce new tumour growth and the size of present tumours. All nodules were resected and the defects closed using rotation flaps. No recurrence of the neoplasm was noted within 10 months after surgery. Trichoblastomas are generally benign but can present as multiple neoplasms that may require surgical resection and may respond to chemotherapy. To the authors' knowledge, this is the first report of multiple trichoblastomas in a dog.
    Veterinary Dermatology 02/2014; 25(1):48-e19. DOI:10.1111/vde.12100 · 1.99 Impact Factor
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    ABSTRACT: The liver was among the first organs in which connexin proteins have been identified. Hepatocytes harbor connexin32 and connexin26, while non-parenchymal liver cells typically express connexin43. Connexins give rise to hemichannels, which dock with counterparts on adjacent cells to form gap junctions. Both hemichannels and gap junctions provide pathways for communication, via paracrine signaling or direct intercellular coupling, respectively. Over the years, hepatocellular gap junctions have been shown to regulate a number of liver-specific functions and to drive liver cell growth. In the last few years, it has become clear that connexin hemichannels are involved in liver cell death, particularly in hepatocyte apoptosis. This also holds true for hemichannels composed of pannexin1, a connexin-like protein recently identified in the liver. Moreover, pannexin1 hemichannels are key players in the regulation of hepatic inflammatory processes. The current paper provides a concise overview of the features of connexins, pannexins and their channels in the liver.
    Frontiers in Physiology 01/2014; 4:405. DOI:10.3389/fphys.2013.00405 · 3.50 Impact Factor
  • 01/2014; 31(1):33-41. DOI:10.4322/jms.ao060313