Resolvin D1 attenuated liver injury caused by chronic ethanol and acute LPS challenge in mice
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ABSTRACT: Alcohol-associated liver disease (ALD) is a major health problem with limited effective treatment options. Alcohol-associated hepatitis (AH) is a subset of severe ALD with a high rate of mortality due to infection, severe inflammation, and ultimately multi-organ failure. There is an urgent need for novel therapeutic approaches to alleviate the human suffering associated with this condition. Resolvin D1 (RvD1) promotes the resolution of inflammation and regulates immune responses. The current study aimed to test the therapeutic efficacy and mechanisms of RvD1-mediated effects on liver injury and inflammation in an experimental animal model that mimics severe AH in humans. Our data demonstrated that mice treated with RvD1 had attenuated liver injury and inflammation caused by EtOH and LPS exposure by limiting hepatic neutrophil accumulation and decreasing hepatic levels of pro-inflammatory cytokines. In addition, RvD1 treatment attenuated hepatic pyroptosis, an inflammatory form of cell death, via downregulation of pyroptosis-related genes such as GTPase family member b10 and guanylate binding protein 2, and reducing cleavage of caspase 11 and gasdermin-D. In vitro experiments with primary mouse hepatocytes and bone marrow-derived macrophages confirmed the effectiveness of RvD1 in the attenuation of pyroptosis. In summary, our data demonstrated that RvD1 treatment provided beneficial effects against liver injury and inflammation in an experimental animal model recapitulating features of severe AH in humans. Our results suggest that RvD1 may be a novel adjunct strategy to traditional therapeutic options for AH patients.
Project description:Background & aims: The role of microRNAs (miRNAs) in Alcoholic Hepatitis (AH) and their potential as therapeutic targets in liver disease has not been explored yet. This study aims at profiling miRNA in AH and identifying dysregulated miRNAs involved in AH pathophysiology. Methods: miRNA expression arrays were performed in 13 AH, 5 alcohol liver disease-induced cirrhosis (ALD-CH), 5 nonalcoholic steatohepatitis induced cirrhosis (NASH-CH), 4 HCV-induced cirrhosis (HCV-CH) and 6 non-injured liver control samples. Genome wide expression profile was retrieved for 12 paired AH and control samples. MiRNA and mRNA expression data was integrated and identified miRNAs were validated in AH samples and in animal models of liver injury. Results: The miRNA array showed 111 upregulated and 66 downregulated miRNAs in AH versus healthy subjects. The comparison of miRNA profile in liver samples from AH among ALD-CH, HCV-CH and NASH-CH identified 18 miRNAs specifically dysregulated in AH. Integrative miRNA and mRNA analysis in AH identified dysregulated miRNAs for which their target genes were also dysregulated. A functional analysis of identified miRNAs and their targets revealed their involvement in the regulation of canonical pathways related to apoptosis, fatty acid metabolism and cell cycle among others. miRNAs expression (miR-182, miR-21, miR-155, miR-214, miR-432, miR-422a) was validated in an independent cohort of AH. MiR-182 expression correlated with cholestasis, disease severity and short-term mortality. Moreover, miR-182 expression is associated to cholestasis with ductular reaction but not to fibrosis and inflammation in animal models of liver injury. Conclusions: AH is characterized by an important dysregulation of miRNA expression with a unique miRNA profile. MiRNAs specifically expressed in AH are associated to cholestasis⦠Uncovered miRNAs are involved in important pathophysiological features in AH suggesting ta regulation of he role of miRNAs in the regulation of AH, and highlight miR-182 as a potential regulator of its pathophysiology. miRNA expression arrays were performed in 13 AH(Alcoholic hepatitis), 5 alcohol liver disease-induced cirrhosis (ALD-CH), 5 nonalcoholic steatohepatitis induced cirrhosis (NASH-CH), 4 HCV-induced cirrhosis (HCV-CH) and 6 non-injured liver control samples(CTRL).
Project description:Background: Alcohol-associated hepatitis (AH) is the clinical manifestation of alcohol-associated liver disease (ALD). AH is a complex disease encompassing the dysregulation of many cells and cell subpopulations. This study used a hepatic spatial transcriptomic and proteomic approach (10X Genomics Visium) to identify hepatic cell populations and their associated transcriptomic and proteomic alterations in human AH. Methods: Formalin fixed parraffin embedded liver tissue from AH patients (n=2) and non-ALD controls (donors) (n=2) were used for Visium spatial transcriptomic and proteomic analysis. Results: AH cell clusters and cell markers were drastically different in regard to tissue pattern and number of cell type as compared to non-ALD controls. Cholangiocytes, endothelial cells, macrophages, and stellate cells were more profuse in AH relative to non-ALD controls. Transcriptionally, proliferating cell nuclear antigen positive (PCNA+) hepatocytes in AH more closely resembled cholangiocytes suggesting they were non-functional hepatocytes derived from cholangiocytes. Further, mitochondria protein coding genes were reduced in AH vs non-ALD control hepatocytes, suggesting reduced functionality and loss of regenerative mechanisms. Macrophages in AH exhibited elevated gene expression involved in exosomes as compared to non-ALD controls. The most upregulated macrophage genes observed in AH were those involved in exosome trafficking and cellular migration. Gene and protein signatures of disease associated hepatocytes (ANXA2+/CXCL1+/CEACAM8+) were elevated in AH and could visually identify a pre-malignant lesion. Conclusions: This study identified global cell type alterations in AH and distinct transcriptomic changes between AH and non-ALD controls. These findings characterizes cellular plasticity and profuse transcriptomic and proteomic changes that are apparent in AH and contributes to the identification of novel therapeutics.
Project description:BACKGROUND & AIMS: There is mounting evidence that microbes resident in the human intestine contribute to diverse alcohol-associated liver diseases (ALD) including the most deadly form known as alcoholic hepatitis (AH). However, mechanisms by which gut microbiota synergize with excessive alcohol intake to promote liver injury are poorly understood. Furthermore, whether drugs that selectively target gut microbial metabolism can improve ALD has never been tested. METHODS: We used liquid chromatography tandem mass spectrometry to quantify the levels of microbe and host choline co-metabolites in healthy controls and AH patients, and identified the metabolite trimethylamine (TMA) as a gut microbe-derived biomarker of AH. In subsequent studies, we treated mice with non-lethal mechanism-based bacterial choline TMA lyase inhibitors to blunt gut microbe-dependent production of TMA in the context of chronic ethanol administration. Indices of liver injury were quantified by complementary RNA sequencing, biochemical, and histological approaches. In addition, we examined the impact of ethanol consumption and TMA lyase inhibition on gut microbiome structure via 16S rRNA sequencing. RESULTS: We show the gut microbial choline metabolite trimethylamine (TMA) is elevated in AH patients, which is correlated with reduced hepatic expression of the TMA oxygenase flavin-containing monooxygenase 3 (FMO3). Provocatively, we find that small molecule inhibition of gut microbial choline TMA lyase activity protects mice from ethanol-induced liver injury. TMA lyase inhibitor-driven improvement in ethanol-induced liver injury is associated with distinct reorganization of the gut microbiome community and host liver transcriptome. CONCLUSIONS: The microbial metabolite TMA is a biomarker of AH, and blocking TMA production from gut microbes can blunt ALD in mice.
Project description:Alcoholic hepatitis (AH) continues to be a disease with high mortality and no efficacious medical treatment. Although severe AH is presented as acute on chronic liver failure, what underlies this transition from chronic alcoholic steatohepatitis (ASH) to AH, is largely unknown. To address this question, unbiased RNA-seq and proteomic analyses were performed on livers of the recently developed AH mouse model which exhibits the shift to AH from chronic ASH upon weekly alcohol binge, and these results are compared with gene expression profiling data from AH patients. This cross-analysis has identified Casp11 (CASP4 in man) as a commonly upregulated gene known to be involved in non-canonical inflammasome pathway. Immunoblotting confirms CASP11/4 activation in AH mice but not in chronic ASH. Gasdermin-D (GSDMD) which induces pyroptosis (lytic cell death caused by bacterial infection) downstream of CASP11/4 activation, is also activated in AH livers. CASP11 deficiency reduces GSDMD activation, bacterial load in the liver, and the severity of AH. Conversely, the deficiency of IL-18, the key anti-microbial cytokine, aggravates hepatic bacterial load, GSDMD activation, and AH. Further, hepatocyte-specific expression of constitutively active GSDMD worsens hepatocellular lytic death and PMN inflammation. These results implicate pyroptosis induced by CASP11/4-GSDMD pathway in the pathogenesis of AH.
Project description:Alcohol-associated hepatitis (AH) is an acute form of alcohol-related liver disease (ArLD) with high mortality rate. AH is histologically characterised by cellular processes including steatosis, inflammation and cell death. Apoptosis is the most studied form of cell death in AH; however, the role of cellular senescence, another response to cellular injury, in AH is unknown. Here we aim to explore the mechanisms of ArLD pathophysiology and define the role of senescence in AH.
Project description:Alcohol-associated hepatitis (AH) is an acute form of alcohol-related liver disease (ArLD) with high mortality rate. AH is histologically characterised by cellular processes including steatosis, inflammation and cell death. Apoptosis is the most studied form of cell death in AH; however, the role of cellular senescence, another response to cellular injury, in AH is unknown. Here we aim to explore the mechanisms of ArLD pathophysiology and define the role of senescence in AH.
Project description:Background & aims: The role of microRNAs (miRNAs) in Alcoholic Hepatitis (AH) and their potential as therapeutic targets in liver disease has not been explored yet. This study aims at profiling miRNA in AH and identifying dysregulated miRNAs involved in AH pathophysiology. Methods: miRNA expression arrays were performed in 13 AH, 5 alcohol liver disease-induced cirrhosis (ALD-CH), 5 nonalcoholic steatohepatitis induced cirrhosis (NASH-CH), 4 HCV-induced cirrhosis (HCV-CH) and 6 non-injured liver control samples. Genome wide expression profile was retrieved for 12 paired AH and control samples. MiRNA and mRNA expression data was integrated and identified miRNAs were validated in AH samples and in animal models of liver injury. Results: The miRNA array showed 111 upregulated and 66 downregulated miRNAs in AH versus healthy subjects. The comparison of miRNA profile in liver samples from AH among ALD-CH, HCV-CH and NASH-CH identified 18 miRNAs specifically dysregulated in AH. Integrative miRNA and mRNA analysis in AH identified dysregulated miRNAs for which their target genes were also dysregulated. A functional analysis of identified miRNAs and their targets revealed their involvement in the regulation of canonical pathways related to apoptosis, fatty acid metabolism and cell cycle among others. miRNAs expression (miR-182, miR-21, miR-155, miR-214, miR-432, miR-422a) was validated in an independent cohort of AH. MiR-182 expression correlated with cholestasis, disease severity and short-term mortality. Moreover, miR-182 expression is associated to cholestasis with ductular reaction but not to fibrosis and inflammation in animal models of liver injury. Conclusions: AH is characterized by an important dysregulation of miRNA expression with a unique miRNA profile. MiRNAs specifically expressed in AH are associated to cholestasis… Uncovered miRNAs are involved in important pathophysiological features in AH suggesting ta regulation of he role of miRNAs in the regulation of AH, and highlight miR-182 as a potential regulator of its pathophysiology.
Project description:Background and aims: We aimed to study the pathogenesis of AH in an animal model of acute-on-chronic alcoholic liver disease which combines chronic hepatic fibrosis with intragastric alcohol administration. Methods: Adult male C57BL6/J mice were treated with CCl4 (0.2 ml/kg, 2×weekly by intraperitoneal injections for 6 weeks) to induce chronic liver fibrosis. Then, ethyl alcohol (EtOH) (up to 25 g/kg/day, for 3 weeks) was administered continuously to mice via a gastric feeding tube, with or without one-half dose of CCl4. Liver and serum markers were evaluated to characterize acute-on-chronic-alcoholic liver disease in our model. Results: CCl4 or EtOH treatment alone induced liver fibrosis or steatohepatitis, respectively, findings that were consistent with expected pathology. Combined treatment with CCl4 and EtOH resulted in a marked exacerbation of liver injury, as evident by the development of hepatic inflammation, marked steatosis, and pericellular fibrosis, and by increased serum transaminase levels, compared to mice treated with either treatment alone. Liver transcriptomic changes specific to combined treatment group demonstrated close concordance with pathways perturbed in human severe cases of AH. In addition to gene expression changes, E. coli and Candida species were also significantly more abundant in livers of mice co-treated with CCl4 and EtOH. Conclusions: Mice treated with CCl4 and EtOH displayed several key characteristics of human AH, including pericellular fibrosis, increased hepatic bacterial load, and dysregulation of the same molecular pathways. This model may be useful for developing therapeutics for AH.
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 is metabolized in the liver, and chronic consumption can lead to inflammation, scarring, and damage to liver cells. The pathogenesis of alcoholic liver disease (ALD), a complicated condition, is characterized by a succession of histopathological alterations that occur through a multistep and multifactorial process. FAF2/UBXD8/ETEA is a ubiquitin ligase adaptor protein and plays a crucial role in the ubiquitin-mediated degradation of misfolded proteins in the endoplasmic reticulum. Recent GWAS study indicated that FAF2 was associated with ALD, but the exact function of FAF2 in ALD has not been identified yet. The objective of this study was to investigate the role of FAF2 in ALD.Our study revealed a noteworthy rise in hepatic FAF2 protein expression among individuals with ALD and mice subjected to chronic-plus-single binge ethanol feeding. The suppression of FAF2 in mice liver provided protection against alcohol-induced hepatic steatosis.