Search

Background/Aims: We tested the pharmacological action of sulfur-containing amino acids on the development of liver fibrosis in rats and on the function of cultured stellate cells.Methods: Liver fibrosis was induced in rats by thioacetamide administration or by ligating the common bile duct. DNA synthesis of cultured stellate cells was evaluated by BrdU incorporation. The expression of proteins and phospho-proteins was determined by western blot analysis. mRNA expression was evaluated by RT-PCR.Results: Oral administration of l-cysteine or l-methionine attenuated the deposition of collagen in liver tissues in the two fibrotic models, accompanying a reduction in the expression of smooth muscle α-actin and platelet-derived growth factor receptor β and mRNAs of collagens, transforming growth factor-βs and tissue inhibitors of matrix metalloproteinase. In cultured stellate cells, l-cysteine and l-methionine suppressed the DNA synthesis and the expression of growth factor receptors, smooth muscle α-actin and type I collagen. They hampered the phosphorylation of p44/42 MAPK and Akt under platelet-derived growth factor-BB stimulation. Stellate cells were found to express methionine adenosyltransferase 2A.Conclusions: l-Cysteine and l-methionine regulate the activation of stellate cells. Their oral supply aids the suppression of the progression of liver fibrosis. [Copyright &y& Elsevier]

Bile duct obstruction causes rapid infiltration of neutrophils into the liver and leads ultimately to hepatic fibrosis. In this study, we assessed whether neutrophils play an active role in the pathogenesis of hepatic fibrosis under conditions of biliary obstruction. We performed bile duct ligation (BDL) on rats, some of which were depleted of neutrophils by means of an anti-neutrophil antiserum. Rats treated with the antiserum had 48% fewer neutrophils than control rats. Despite this, they showed no difference in either bile duct proliferation or hepatic fibrogenesis after BDL compared with control rats. In a second set of experiments, we performed BDL on mice with an underlying defect in neutrophil function due to transgenic expression of interleukin-8. Mice with neutrophil dysfunction deposited less (−22%) collagen in their livers after BDL than wild-type mice, but the difference was not statistically significant. In summary, data from two independent rodent models indicate that infiltrating neutrophils do not influence hepatic fibrogenesis following bile duct obstruction. The findings suggest that neutrophils play little if any role in the immunomodulation of liver fibrosis. [Copyright &y& Elsevier]

Background/Aims: Taurohyodeoxycholate (THDCA) and tauroursodeoxycholate (TUDCA) induce more bile flow per molecule excreted compared to endogenous bile acids. The aim of this study is to determine if the hypercholeretic effect of tauroursodeoxycholate or taurohyodeoxycholate in normal and bile duct ligated (BDL) rats is due to increased ductal secretion.Methods: Normal or BDL rats were infused with tauroursodeoxycholate or taurohyodeoxycholate and bile flow, bicarbonate, bile salt, cholesterol, and phospholipid secretion were measured. Cholangiocytes were stimulated with taurohyodeoxycholate or tauroursodeoxycholate, and secretin-stimulated secretion was measured.Results: Taurohyodeoxycholate and tauroursodeoxycholate increased bile flow more in BDL than normal rats. Tauroursodeoxycholate increased bicarbonate secretion more in BDL compared to normal rats. Taurohyodeoxycholate when infused with taurocholate increased bile flow (but not phospholipid excretion) to a greater degree in BDL compared to normal rats. Taurohyodeoxycholate and tauroursodeoxycholate decreased secretin-stimulated cholangiocyte secretion.Conclusions: Consistent with a ductal origin for bile acid-induced hypercholeresis, taurohyodeoxycholate and tauroursodeoxycholate produced a greater hypercholeresis in BDL than normal rats. Tauroursodeoxycholate- (but not taurohyodeoxycholate-) stimulated hypercholeresis is associated with increased HCO3− secretion. Tauroursodeoxycholate increases biliary HCO3− secretion by a mechanism unrelated to secretin-stimulated cholangiocyte secretion. Taurohyodeoxycholate-induced hypercholeresis in BDL rats is unrelated to enhanced phospholipid excretion. [Copyright &y& Elsevier]

Background & Aims: Non-absorbable inhibitors of the apical sodium-dependent bile acid transporter (ASBT; also called ileal bile acid transporter [IBAT]) are recently approved or in clinical development for multiple cholestatic liver disorders and lead to a reduction in pruritus and (markers for) liver injury. Unfortunately, non-absorbable ASBT inhibitors (ASBTi) can induce diarrhoea or may be ineffective if cholestasis is extensive and largely precludes intestinal excretion of bile acids. Systemically acting ASBTi that divert bile salts towards renal excretion may alleviate these issues., Methods: Bile duct ligation (BDL) was performed in ASBT-deficient (ASBT knockout [KO]) mice as a model for chronic systemic ASBT inhibition in obstructive cholestasis. Co-infusion of radiolabelled taurocholate and inulin was used to quantify renal bile salt excretion after BDL. In a second (wild-type) mouse model, a combination of obeticholic acid (OCA) and intestine-restricted ASBT inhibition was used to lower the bile salt pool size before BDL., Results: After BDL, ASBT KO mice had reduced plasma bilirubin and alkaline phosphatase compared with wild-type mice with BDL and showed a marked reduction in liver necrotic areas at histopathological analysis, suggesting decreased BDL-induced liver damage. Furthermore, ASBT KO mice had reduced bile salt pool size, lower plasma taurine-conjugated polyhydroxylated bile salt, and increased urinary bile salt excretion. Pretreatment with OCA + ASBTi in wild-type mice reduced the pool size and greatly improved liver injury markers and liver histology., Conclusions: A reduced bile salt pool at the onset of cholestasis effectively lowers cholestatic liver injury in mice. Systemic ASBT inhibition may be valuable as treatment for cholestatic liver disease by lowering the pool size and increasing renal bile salt output even under conditions of minimal faecal bile salt secretion., Lay Summary: Novel treatment approaches against cholestatic liver disease (resulting in reduced or blocked flow of bile) involve non-absorbable inhibitors of the bile acid transport protein ASBT, but these are not always effective and/or can cause unwanted side effects. In this study, we demonstrate that systemic inhibition/inactivation of ASBT protects mice against developing severe cholestatic liver injury after bile duct ligation, by reducing bile salt pool size and increasing renal bile salt excretion., Competing Interests: Ambys consultancy to institution of SFJVDG. The other authors report no conflicts of interest. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2022 The Author(s).)

Background & Aims: XBP1 modulates the macrophage proinflammatory response, but its function in macrophage stimulator of interferon genes (STING) activation and liver fibrosis is unknown. X-box binding protein 1 (XBP1) has been shown to promote macrophage nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) activation in steatohepatitis. Herein, we aimed to explore the underlying mechanism of XBP1 in the regulation of STING signalling and the subsequent NLRP3 activation during liver fibrosis., Methods: XBP1 expression was measured in the human fibrotic liver tissue samples. Liver fibrosis was induced in myeloid-specific Xbp1 -, STING-, and Nlrp3 -deficient mice by carbon tetrachloride injection, bile duct ligation, or a methionine/choline-deficient diet., Results: Although increased XBP1 expression was observed in the fibrotic liver macrophages of mice and clinical patients, myeloid-specific Xbp1 deficiency or pharmacological inhibition of XBP1 protected the liver against fibrosis. Furthermore, it inhibited macrophage NLPR3 activation in a STING/IRF3-dependent manner. Oxidative mitochondrial injury facilitated cytosolic leakage of macrophage self-mtDNA and cGAS/STING/NLRP3 signalling activation to promote liver fibrosis. Mechanistically, RNA sequencing analysis indicated a decreased mtDNA expression and an increased BCL2/adenovirus E1B interacting protein 3 (BNIP3)-mediated mitophagy activation in Xbp1 -deficient macrophages. Chromatin immunoprecipitation (ChIP) assays further suggested that spliced XBP1 bound directly to the Bnip3 promoter and inhibited the transcription of Bnip3 in macrophages. Xbp1 deficiency decreased the mtDNA cytosolic release and STING/NLRP3 activation by promoting BNIP3-mediated mitophagy activation in macrophages, which was abrogated by Bnip3 knockdown. Moreover, macrophage XBP1/STING signalling contributed to the activation of hepatic stellate cells., Conclusions: Our findings demonstrate that XBP1 controls macrophage cGAS/STING/NLRP3 activation by regulating macrophage self-mtDNA cytosolic leakage via BNIP3-mediated mitophagy modulation, thus providing a novel target against liver fibrosis., Lay Summary: Liver fibrosis is a typical progressive process of chronic liver disease, driven by inflammatory and immune responses, and is characterised by an excess of extracellular matrix in the liver. Currently, there is no effective therapeutic strategy for the treatment of liver fibrosis, resulting in high mortality worldwide. In this study, we found that myeloid-specific Xbp1 deficiency protected the liver against fibrosis in mice, while XBP1 inhibition ameliorated liver fibrosis in mice. This study concluded that targeting XBP1 signalling in macrophages may provide a novel strategy for protecting the liver against fibrosis., Competing Interests: The authors declare no conflicts of interest. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2022 The Author(s).)

Background & Aims: Increased plasma ammonia concentration and consequent disruption of brain energy metabolism could underpin the pathogenesis of hepatic encephalopathy (HE). Brain energy homeostasis relies on effective maintenance of brain oxygenation, and dysregulation impairs neuronal function leading to cognitive impairment. We hypothesised that HE is associated with reduced brain oxygenation and we explored the potential role of ammonia as an underlying pathophysiological factor., Methods: In a rat model of chronic liver disease with minimal HE (mHE; bile duct ligation [BDL]), brain tissue oxygen measurement, and proton magnetic resonance spectroscopy were used to investigate how hyperammonaemia impacts oxygenation and metabolic substrate availability in the central nervous system. Ornithine phenylacetate (OP, OCR-002; Ocera Therapeutics, CA, USA) was used as an experimental treatment to reduce plasma ammonia concentration., Results: In BDL animals, glucose, lactate, and tissue oxygen concentration in the cerebral cortex were significantly lower than those in sham-operated controls. OP treatment corrected the hyperammonaemia and restored brain tissue oxygen. Although BDL animals were hypotensive, cortical tissue oxygen concentration was significantly improved by treatments that increased arterial blood pressure. Cerebrovascular reactivity to exogenously applied CO 2 was found to be normal in BDL animals., Conclusions: These data suggest that hyperammonaemia significantly decreases cortical oxygenation, potentially compromising brain energy metabolism. These findings have potential clinical implications for the treatment of patients with mHE., Lay Summary: Brain dysfunction is a serious complication of cirrhosis and affects approximately 30% of these patients; however, its treatment continues to be an unmet clinical need. This study shows that oxygen concentration in the brain of an animal model of cirrhosis is markedly reduced. Low arterial blood pressure and increased ammonia (a neurotoxin that accumulates in patients with liver failure) are shown to be the main underlying causes. Experimental correction of these abnormalities restored oxygen concentration in the brain, suggesting potential therapeutic avenues to explore., Competing Interests: RJ has research collaborations with Takeda and Yaqrit and consults for Yaqrit. RJ is the founder of Yaqrit Limited, which is developing UCL inventions for treatment of patients with cirrhosis. RJ is an inventor of ornithine phenylacetate, which was licensed by UCL to Mallinckrodt. He is also the inventor of Yaq-001, DIALIVE, and Yaq-005, the patents for which have been licensed by his University into a UCL spinout company, Yaqrit Ltd. All other authors report no conflict of interest. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2022 The Authors.)

Background & Aims: In cirrhosis, astrocytic swelling is believed to be the principal mechanism of ammonia neurotoxicity leading to hepatic encephalopathy (HE). The role of neuronal dysfunction in HE is not clear. We aimed to explore the impact of hyperammonaemia on mitochondrial function in primary co-cultures of neurons and astrocytes and in acute brain slices of cirrhotic rats using live cell imaging., Methods: To primary cocultures of astrocytes and neurons, low concentrations (1 and 5 μM) of NH 4 Cl were applied. In rats with bile duct ligation (BDL)-induced cirrhosis, a model known to induce hyperammonaemia and minimal HE, acute brain slices were studied. One group of BDL rats was treated twice daily with the ammonia scavenger ornithine phenylacetate (OP; 0.3 g/kg). Fluorescence measurements of changes in mitochondrial membrane potential (Δψm), cytosolic and mitochondrial reactive oxygen species (ROS) production, lipid peroxidation (LP) rates, and cell viability were performed using confocal microscopy., Results: Neuronal cultures treated with NH 4 Cl exhibited mitochondrial dysfunction, ROS overproduction, and reduced cell viability (27.8 ± 2.3% and 41.5 ± 3.7%, respectively) compared with untreated cultures (15.7 ± 1.0%, both p <0.0001). BDL led to increased cerebral LP ( p  = 0.0003) and cytosolic ROS generation ( p <0.0001), which was restored by OP (both p <0.0001). Mitochondrial function was severely compromised in BDL, resulting in hyperpolarisation of Δψm with consequent overconsumption of adenosine triphosphate and augmentation of mitochondrial ROS production. Administration of OP restored Δψm. In BDL animals, neuronal loss was observed in hippocampal areas, which was partially prevented by OP., Conclusions: Our results elucidate that low-grade hyperammonaemia in cirrhosis can severely impact on brain mitochondrial function. Profound neuronal injury was observed in hyperammonaemic conditions, which was partially reversible by OP. This points towards a novel mechanism of HE development., Lay Summary: The impact of hyperammonaemia, a common finding in patients with liver cirrhosis, on brain mitochondrial function was investigated in this study. The results show that ammonia in concentrations commonly seen in patients induces severe mitochondrial dysfunction, overproduction of damaging oxygen molecules, and profound injury and death of neurons in rat brain cells. These findings point towards a novel mechanism of ammonia-induced brain injury in liver failure and potential novel therapeutic targets., Competing Interests: PRA, AJK, AH, AnH, and AYA have no conflicts to declare. RJ has research collaborations with Yaqrit and Takeda. He is the inventor of OPA, which has been patented by University College London and licensed to Mallinckrodt Pharma. He is also a founder of Yaqrit Limited, a spin out company from University College London. He has also cofounded Hepyx Ltd. and Cyberliver Ltd. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2022 The Author(s).)

Background & Aims: Organic solute transporter (OST) subunits OSTα and OSTβ facilitate bile acid efflux from the enterocyte into the portal circulation. Patients with deficiency of OSTα or OSTβ display considerable variation in the level of bile acid malabsorption, chronic diarrhea, and signs of cholestasis. Herein, we generated and characterized a mouse model of OSTβ deficiency., Methods: Ostβ -/- mice were generated using CRISR/Cas9 and compared to wild-type and Ostα -/- mice. OSTβ was re-expressed in livers of Ostβ -/- mice using adeno-associated virus serotype 8 vectors. Cholestasis was induced in both models by bile duct ligation (BDL) or 3.5-diethoxycarbonyl-1.4-dihydrocollidine (DDC) feeding., Results: Similar to Ostα -/- mice, Ostβ -/- mice exhibited elongated small intestines with blunted villi and increased crypt depth. Increased expression levels of ileal Fgf15, and decreased Asbt expression in Ostβ -/- mice indicate the accumulation of bile acids in the enterocyte. In contrast to Ostα -/- mice, induction of cholestasis in Ostβ -/- mice by BDL or DDC diet led to lower survival rates and severe body weight loss, but an improved liver phenotype. Restoration of hepatic Ostβ expression via adeno-associated virus-mediated overexpression did not rescue the phenotype of Ostβ -/- mice., Conclusions: OSTβ is pivotal for bile acid transport in the ileum and its deficiency leads to an intestinal phenotype similar to Ostα -/- mice, but it exerts distinct effects on survival and the liver phenotype, independent of its expression in the liver. Our findings provide insights into the variable clinical presentation of patients with OSTα and OSTβ deficiencies., Lay Summary: Organic solute transporter (OST) subunits OSTα and OSTβ together facilitate the efflux of conjugated bile acids into the portal circulation. Ostα knockout mice have longer and thicker small intestines and are largely protected against experimental cholestatic liver injury. Herein, we generated and characterized Ostβ knockout mice for the first time. Ostα and Ostβ knockout mice shared a similar phenotype under normal conditions. However, in cholestasis, Ostβ knockout mice had a worsened overall phenotype which indicates a separate and specific role of OSTβ, possibly as an interacting partner of other intestinal proteins., Competing Interests: The authors declare no conflicts of interest that pertain to this work. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2022 The Authors.)

Background & Aims: Mitochondria are the major organelles for the formation of reactive oxygen species (ROS) in the cell, and mitochondrial dysfunction has been described as a key factor in the pathogenesis of cholestatic liver disease. The methylation-controlled J-protein (MCJ) is a mitochondrial protein that interacts with and represses the function of complex I of the electron transport chain. The relevance of MCJ in the pathology of cholestasis has not yet been explored., Methods: We studied the relationship between MCJ and cholestasis-induced liver injury in liver biopsies from patients with chronic cholestatic liver diseases, and in livers and primary hepatocytes obtained from WT and MCJ-KO mice. Bile duct ligation (BDL) was used as an animal model of cholestasis, and primary hepatocytes were treated with toxic doses of bile acids. We evaluated the effect of MCJ silencing for the treatment of cholestasis-induced liver injury., Results: Elevated levels of MCJ were detected in the liver tissue of patients with chronic cholestatic liver disease when compared with normal liver tissue. Likewise, in mouse models, the hepatic levels of MCJ were increased. After BDL, MCJ-KO animals showed significantly decreased inflammation and apoptosis. In an in vitro model of bile-acid induced toxicity, we observed that the loss of MCJ protected mouse primary hepatocytes from bile acid-induced mitochondrial ROS overproduction and ATP depletion, enabling higher cell viability. Finally, the in vivo inhibition of the MCJ expression, following BDL, showed reduced liver injury and a mitigation of the main cholestatic characteristics., Conclusions: We demonstrated that MCJ is involved in the progression of cholestatic liver injury, and our results identified MCJ as a potential therapeutic target to mitigate the liver injury caused by cholestasis., Lay Summary: In this study, we examine the effect of mitochondrial respiratory chain inhibition by MCJ on bile acid-induced liver toxicity. The loss of MCJ protects hepatocytes against apoptosis, mitochondrial ROS overproduction, and ATP depletion as a result of bile acid toxicity. Our results identify MCJ as a potential therapeutic target to mitigate liver injury in cholestatic liver diseases., Competing Interests: Dr. María Luz Martínez-Chantar advises for Mitotherapeutix LLC. Dr. Javier Crespo reports grants and research support from Gilead Sciences, AbbVie, MSD, and Intercept Pharmaceuticals (all outside the scope of the submitted work). He is a speaker for Gilead Sciences and AbbVie. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2021 The Author(s).)

The family of vascular endothelial growth factors (VEGFs) includes 5 members (VEGF-A to -D, and placenta growth factor), which regulate several critical biological processes. VEGF-A exerts a variety of biological effects through high-affinity binding to tyrosine kinase receptors (VEGFR-1, -2 and -3), co-receptors and accessory proteins. In addition to its fundamental function in angiogenesis and endothelial cell biology, VEGF/VEGFR signalling also plays a role in other cell types including epithelial cells. This review provides an overview of VEGF signalling in biliary epithelial cell biology in both normal and pathologic conditions. VEGF/VEGFR-2 signalling stimulates bile duct proliferation in an autocrine and paracrine fashion. VEGF/VEGFR-1/VEGFR-2 and angiopoietins are involved at different stages of biliary development. In certain conditions, cholangiocytes maintain the ability to secrete VEGF-A, and to express a functional VEGFR-2 receptor. For example, in polycystic liver disease, VEGF secreted by cystic cells stimulates cyst growth and vascular remodelling through a PKA/RAS/ERK/HIF1α-dependent mechanism, unveiling a new level of complexity in VEFG/VEGFR-2 regulation in epithelial cells. VEGF/VEGFR-2 signalling is also reactivated during the liver repair process. In this context, pro-angiogenic factors mediate the interactions between epithelial, mesenchymal and inflammatory cells. This process takes place during the wound healing response, however, in chronic biliary diseases, it may lead to pathological neo-angiogenesis, a condition strictly linked with fibrosis progression, the development of cirrhosis and related complications, and cholangiocarcinoma. Novel observations indicate that in cholangiocarcinoma, VEGF is a determinant of lymphangiogenesis and of the immune response to the tumour. Better insights into the role of VEGF signalling in biliary pathophysiology might help in the search for effective therapeutic strategies., Competing Interests: The authors declare no conflicts of interest related to this work. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2021 The Authors.)

Background & Aims: As the composition of the bile acid (BA) pool has a major impact on liver pathophysiology, we studied its regulation by the BA receptor Takeda G protein coupled receptor (TGR5), which promotes hepatoprotection against BA overload., Methods: Wild-type, total and hepatocyte-specific TGR5-knockout, and TGR5-overexpressing mice were used in: partial (66%) and 89% extended hepatectomies (EHs) upon normal, ursodeoxycholic acid (UDCA)- or cholestyramine (CT)-enriched diet, bile duct ligation (BDL), cholic acid (CA)-enriched diet, and TGR5 agonist (RO) treatments. We thereby studied the impact of TGR5 on: BA composition, liver injury, regeneration and survival. We also performed analyses on the gut microbiota (GM) and gallbladder (GB). Liver BA composition was analysed in patients undergoing major hepatectomy., Results: The TGR5-KO hyperhydrophobic BA composition was not directly related to altered BA synthesis, nor to TGR5-KO GM dysbiosis, as supported by hepatocyte-specific KO mice and co-housing experiments, respectively. The TGR5-dependent control of GB dilatation was crucial for BA composition, as determined by experiments including RO treatment and/or cholecystectomy. The poor TGR5-KO post-EH survival rate, related to exacerbated peribiliary necrosis and BA overload, was improved by shifting BAs toward a less toxic composition (CT treatment). After either BDL or a CA-enriched diet with or without cholecystectomy, we found that GB dilatation had strong TGR5-dependent hepatoprotective properties. In patients, a more hydrophobic liver BA composition was correlated with an unfavourable outcome after hepatectomy., Conclusions: BA composition is crucial for hepatoprotection in mice and humans. We indicate TGR5 as a key regulator of BA profile and thereby as a potential hepatoprotective target under BA overload conditions., Lay Summary: Through multiple in vivo experimental approaches in mice, together with a patient study, this work brings some new light on the relationships between biliary homeostasis, gallbladder function, and liver protection. We showed that hepatic bile acid composition is crucial for optimal liver repair, not only in mice, but also in human patients undergoing major hepatectomy., Competing Interests: The authors declare no conflicts of interest that pertain to this work., (© 2020 The Authors.)

Brain edema is a common feature associated with hepatic encephalopathy (HE). In patients with acute HE, brain edema has been shown to play a crucial role in the associated neurological deterioration. In chronic HE, advanced magnetic resonance imaging (MRI) techniques have demonstrated that low-grade brain edema appears also to be an important pathological feature. This review explores the different methods used to measure brain edema ex vivo and in vivo in animal models and in humans with chronic HE. In addition, an in-depth description of the main studies performed to date is provided. The role of brain edema in the neurological alterations linked to HE and whether HE and brain edema are the manifestations of the same pathophysiological mechanism or two different cerebral manifestations of brain dysfunction in liver disease are still under debate. In vivo MRI/magnetic resonance spectroscopy studies have allowed insight into the development of brain edema in chronic HE. However, additional in vivo longitudinal and multiparametric/multimodal studies are required (in humans and animal models) to elucidate the relationship between liver function, brain metabolic changes, cellular changes, cell swelling, and neurological manifestations in chronic HE.

Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome that occurs during chronic liver disease (CLD). While ammonia and other precipitating factors in liver disease including inflammation, bile acids, oxidative stress, and lactate play a role in the pathogenesis of HE, the exact mechanism that leads to HE is not fully understood. Notably, accumulating evidence points toward a synergic effect rather than independent actions among precipitating factors that contributes to the development and severity of HE in CLD. Hence, this review is aimed to briefly discuss the single and synergic interplay of pathological factors in the progression and severity of HE.

Background: Cirrhosis, a common consequence of chronic liver inflammation is associated with various cardiovascular dysfunctions which are called cirrhotic cardiomyopathy (CC). Among the various possible causes of CC, apoptosis is considered to have a pivotal role., Objectives: To explore the contribution of endogenous opioids in the apoptosis process in a rat model of CC., Material and Methods: Four genes were selected to cover both intrinsic and extrinsic pathways of apoptosis. Cardiac samples from 4 groups of rats were evaluated. Two groups were cirrhotic through bile duct ligation (BDL) receiving either naltrexone (BDL-naltrexone) or saline (BDL-saline), two others were normal rats as sham groups receiving either naltrexone (sham-naltrexone) or saline (sham-saline). Expression level of BCL2, Caspase3, Fas and FasL was explored in all groups using reverse transcriptase real-time PCR., Results: BDL-saline group showed significant over-expression of BCL2, caspase3 and Fas. BCL2 expression was 1.44 ( P  < 0.001) and caspasse3 was 1.35 ( P  < 0.001) times higher than sham-saline group, Fas was also overexpressed 1.3 ( P  < 0.001) times higher than BDL-naltrexone group and 1.91 ( P  < 0.001) compared to sham-naltrexone group. Caspase3 expression was 1.35 ( P  < 0.001) folds higher than sham-naltrexone group. The expression pattern of FasL revealed no statistically significant change among study groups., Conclusion: Fas molecule enrollment during CC is a novel finding. Fas molecule is activated during cirrhosis through elevated levels of endogenous opioids. This pathway is one of the leading causes of CC. Our findings also demonstrated the protective role of naltrexone as opioids antagonist on cardiomyocytes in a rat model of CC.

Liver fibrosis remains a significant clinical problem in the United States and throughout the world. Although important advances in the understanding of this disease have been made, no effective pharmacologic agents have been developed that directly prevent or reverse the fibrotic process. Many of the successes in liver fibrosis treatment have been targeted toward treating the cause of fibrosis, such as the development of new antivirals that eradicate hepatitis virus. For many patients, however, this is not feasible, so a liver transplant remains the only viable option. Thus, there is a critical need to identify new therapeutic targets that will slow or reverse the progression of fibrosis in such patients. Research over the last 16 years has identified hypoxia-inducible factors (HIFs) as key transcription factors that drive many aspects of liver fibrosis, making them potential targets of therapy. In this review, we discuss the latest work on HIFs and liver fibrosis, including the cell-specific functions of these transcription factors in the development of liver fibrosis.

Hepatic encephalopathy (HE) is a major neurological complication of severe liver disease that presents in acute and chronic forms. While elevated brain ammonia level is known to be a major etiological factor in this disorder, recent studies have shown a significant role of neuroinflammation in the pathogenesis of both acute and chronic HE. This review summarizes the involvement of ammonia in the activation of microglia, as well as the means by which ammonia triggers inflammatory responses in these cells. Additionally, the role of ammonia in stimulating inflammatory events in brain endothelial cells (ECs), likely through the activation of the toll-like receptor-4 and the associated production of cytokines, as well as the stimulation of various inflammatory factors in ECs and in astrocytes, are discussed. This review also summarizes the inflammatory mechanisms by which activation of ECs and microglia impact on astrocytes leading to their dysfunction, ultimately contributing to astrocyte swelling/brain edema in acute HE. The role of microglial activation and its contribution to the progression of neurobehavioral abnormalities in chronic HE are also briefly presented. We posit that a better understanding of the inflammatory events associated with acute and chronic HE will uncover novel therapeutic targets useful in the treatment of patients afflicted with HE.