Project description:Alcoholic liver disease (ALD) encompasses conditions ranging from simple steatosis to cirrhosis and even liver cancer. It has gained significant global attention in recent years. Despite this, effective pharmacological treatments for ALD remain elusive, and the core mechanisms underlying the disease are not yet fully comprehended. S100A16, a newly identified calcium-binding protein, is linked to lipid metabolism. Our research has discovered elevated levels of the S100A16 protein in both serum and liver tissue of ALD patients. A similar surge in hepatic S100A16 expression was noted in a Gao-binge alcohol feeding mouse model. S100a16 knockdown alleviated ethanol-induced liver injury, steatosis and inflammation. Conversely, S100a16 transgenic mice showed aggravating phenomenon. Mechanistically, we identify mesencephalic astrocyte-derived neurotrophic factor (MANF) as a regulated entity downstream of S100a16 deletion. MANF inhibited ER-stress signal transduction induced by alcohol stimulation. Meanwhile, MANF silencing suppressed the inhibition effect of S100a16 knockout on ethanol-induced lipid droplets accumulation in primary hepatocytes. Our data suggested that S100a16 deletion protects mice against alcoholic liver lipid accumulation and inflammation dependent on upregulating MANF and inhibiting ER stress. This offers a potential therapeutic avenue for ALD treatment.
Project description:Alcohol-associated liver disease (ALD) is a major cause of alcohol related mortality. Recently we identified hepatic demethylases KDM5B and KDM5C as important sex-specific epigenetic regulators of alcohol response in the liver. In this study we aimed to study the molecular mechanisms of KDM5-dependent ALD development and resolution. We found that alcohol induces pathological changes in cell-cell communication in the liver that are in part mediated by epigenetic changes in hepatocytes mediated by histone demethylase KDM5B. Using cell type specific knockout mice, we found that KDM5B histone demethylase was a key regulator of alcohol-induced epigenetic changes in hepatocytes. Moreover, it regulated hepatocytes-non-parenchymal cell crosstalk that promoted inflammation and fibrosis development in ALD. This mechanism was specific to females. In males KDM5B deficiency was not sufficient to prevent fibrosis development. In contrast KDM5B demethylase loss promoted fibrosis resolution in both males and females. This mechanism involved changes in hepatocyte-macrophage crosstalk and LXRα activation, which we identified to be critical for the fibrosis resolution process. CONCLUSION: In summary, KDM5B demethylase is a regulator of cell-cell crosstalk involved in disease progression in females and in disease resolution in both sexes.
Project description:Alcohol-associated liver disease is accompanied by changes in the intestinal mycobiome. How fungal dysbiosis contributes to liver disease is not clear. T-helper (Th17) cells mediate immune responses against fungi, but the interleukin 17 (IL17) pathway has been associated with pathogenesis of alcohol-associated liver disease. Here, we demonstrate that Candida albicans (C. albicans)-specific Th17 cells are increased in the circulation and present in the liver of patients with alcohol-associated liver disease. Chronic ethanol administration to mice results in migration of C. albicans-reactive Th17 cells from the intestine to the liver. The antifungal agent nystatin reduced intestinal fungal overgrowth, decreased C. albicans-specific Th17 cells in the liver, and reduced features of ethanol-induced liver disease in mice. Transgenic mice that express a T-cell receptor (TCR) reactive to Candida antigens develop more severe ethanol-induced liver disease than transgene-negative littermates; disease severity was reduced by administration of an antibody against IL17 to the TCR transgenic mice. Adoptive transfer of C. albicans-reactive Th17 cells exacerbated ethanol-induced liver disease in wild-type mice. IL17 receptor A (IL17ra) signaling in Kupffer cells was required for the effects of C. albicans-reactive Th17 cells. Our findings indicate that ethanol increases C. albicans-reactive Th17 cells, which contribute to alcohol-associated liver disease.
Project description:Alcohol-associated liver disease is accompanied by changes in the intestinal mycobiome. How fungal dysbiosis contributes to liver disease is not clear. T-helper (Th17) cells mediate immune responses against fungi, but the interleukin 17 (IL17) pathway has been associated with pathogenesis of alcohol-associated liver disease. Here, we demonstrate that Candida albicans (C. albicans)-specific Th17 cells are increased in the circulation and present in the liver of patients with alcohol-associated liver disease. Chronic ethanol administration to mice results in migration of C. albicans-reactive Th17 cells from the intestine to the liver. The antifungal agent nystatin reduced intestinal fungal overgrowth, decreased C. albicans-specific Th17 cells in the liver, and reduced features of ethanol-induced liver disease in mice. Transgenic mice that express a T-cell receptor (TCR) reactive to Candida antigens develop more severe ethanol-induced liver disease than transgene-negative littermates; disease severity was reduced by administration of an antibody against IL17 to the TCR transgenic mice. Adoptive transfer of C. albicans-reactive Th17 cells exacerbated ethanol-induced liver disease in wild-type mice. IL17 receptor A (IL17ra) signaling in Kupffer cells was required for the effects of C. albicans-reactive Th17 cells. Our findings indicate that ethanol increases C. albicans-reactive Th17 cells, which contribute to alcohol-associated liver disease.
Project description:Mitochondrial MATα1 is selectively depleted in alcohol-associated liver disease through a mechanism that involves the isomerase PIN1 and the kinase CK2. Alcohol activates CK2, which phosphorylates MATα1 at Ser114 facilitating interaction with PIN1, thereby inhibiting its mitochondrial localization. Blocking PIN1-MATα1 interaction increased mitochondrial MATα1 levels and protected against alcohol-induced mitochondrial dysfunction.
Project description:Scope: Alcoholic liver disease (ALD) is a major cause of chronic liver disease and is induced by alcohol consumption. Acetaldehyde produced by alcohol metabolism enhances the fibrosis of the liver through hepatic stellate cells. Additionally, alcohol administration causes the accumulation of reactive oxygen species (ROS), which induce hepatocyte-injury-mediated lipid peroxidation. The purpose of this study was to investigate the protective effects of iso-α-acids against alcoholic liver injury in hepatocytes in mice. Methods and results: C57BL/6N mice were fed diets containing isomerized hop extract, which mainly consists of iso-α-acids. After 7 days of feeding, acetaldehyde was administered by a single intraperitoneal injection. The acetaldehyde-induced increases in serum AST and ALT levels were suppressed by iso-α-acids intake. Hepatic gene expression analyses showed the upregulation of the glutathione-S-transferase, alcohol dehydrogenase and aldehyde dehydrogenase genes. In vitro, iso-α-acids induced the nuclear translocation of nuclear factor erythroid 2-like 2 (Nfe2l2; Nrf2), a master regulator of antioxidant and detoxifying systems, and upregulated the enzymatic activities of glutathione-S-transferase and aldehyde dehydrogenase. Conclusions: These results suggest that iso-α-acids intake prevents alcoholic liver disease injury by reducing oxidative stress via the Nrf2-mediated pathway.
Project description:Chronic and binge ethanol consumption in humans and in animal models has been associated with the induction of injury (such as fibrosis and scarring) in the liver as well as the intestine, brain, lung and immune system. The effects of chronic ethanol consumption on the human kidney are protective as seen in large population studies are controversial with the preponderance of the data suggesting protection less so than injury. The most recent meta-analysis was by Konig et al (2015) who studied 5476 participants aged 28–75 years from the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study to assess associations between alcohol consumption and risk of chronic kidney disease (CKD). They found in this population-based cohort, alcohol consumption was inversely associated with the risk of developing CKD. The protective effects of ethanol on the kidney present a unique model system to develop new hypothesis on protection against end organ damage by fibrosis. The data on the effects of alcohol or alcohol consumption at the molecular level on renal parenchyma are sparse. In cell culture and animal models chronic ethanol exposure has been show to induce protein post-translational modification (acetylation), protein expression (upregulation of cytochrome P450 CYP2E1 and local platelet-activating factor receptor (PAFR) ligand formation) as well as neutrophil infiltration and activation. Since hepatocytes do not express PAFR, these data suggest that the response of the kidney to chronic alcohol consumption is distinct from that of the liver or lung. Therefore, we hypothesized that mechanisms of ethanol-induced renal injury or protection are regulated by a protein signaling networks (PSN) modulated acutely by the phosphoproteome and long term epigenetically by the acetylproteome. To address this hypothesis we have initiated a tiered proteomics study to determine the effects of chronic alcohol consumption on the murine kidney and with a secondary insult of acute exposure of lipopolysaccharide (LPS) on the renal proteome, phosphoproteome and the acetylproteome. Data have already been collected on the total proteome and the phosphoproteome using a multiplexing approach. Data will be collected early spring on the acetylproteome.