Silent Alcoholic Steatohepatitis vs Alcoholic Hepatitis: Clinical, Histological and Transcriptome Analysis
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ABSTRACT: BACKGROUND: Alcohol-related liver disease ranges from silent alcoholic steatohepatitis (sASH), an asymptomatic and compensated phenotype, to life- threatening alcoholic hepatitis (AH). A systematic comparative study of the clinical, histological and molecular features of these subtypes is lacking. METHODS : Two large cohorts of patients were recruited in an international, observational multi-center study: a retrospective cohort of patients with sASH (n=110) and a prospective cohort of patients with AH (two subgroups with n=121 and 104). sASH and AH were compared by doing clinical, analytical, immunohistochemistry and hepatic RNA microarray analysis. FINDINGS: Age and mean alcohol intake were similar in patients with sASH vs AH. AH showed lower mean arterial pressure than sASH. AH patients had greater aspartate amino transferase/alanine amino transferase ratio and lower gamma- glutamyl transferase levels than AH. Individuals with AH demonstrated profound liver failure, lower blood pressure and increased mortality. Histologically, the grade of steatosis, ballooning and pericellular fibrosis were similar in both groups, while advanced fibrosis, Mallory-Denk bodies, bilirubinostasis, severe neutrophil infiltration and progenitor cell expansion were more frequent among AH patients. One-year mortality was 10% in sASH and 50% in AH. Transcriptome analysis revealed a profound gene dysregulation within both phenotypes when compare to controls. Globally, AH patients exhibited changes in 4,921 genes, while the number of dysregulated genes in sASH patients was less pronounced -1,327-. While sASH was characterized by deregulated expression of genes involved in matrisome and immune response, the development of AH resulted in a marked deregulation of genes involved in hepatocyte reprogramming and bile acid metabolism. INTERPRETATION: Despite comparable daily alcohol intake, AH patients presented with worse liver function and hemodynamic status compared to sASH. Bilirubinostasis, severe fibrosis and progenitor cell expansion were prominent features of AH. AH patients exhibited a more profound deregulation of gene expression compared to sASH.
Project description:Alcoholic hepatitis (AH) is the most severe form of alcoholic liver disease and occurs in patients with excessive alcohol intake It is characterized by marked hepatocellular damage, steatosis and pericellular fibrosis. Patients with severe AH have a poor short-term prognosis. Unfortunately, current therapies (i.e. corticosteroids and pentoxyphylline) are not effective in many patients and novel targeted therapies are urgently needed. The development of such therapies is hampered by a poor knowledge of the underlying molecular mechanisms. Based on studies from animal models, TNF alfa was proposed to play a pivotal role in the mechanisms of AH. Consequently, drugs interfering TNF alfa were tested in these patients. The results were disappointing due to an increased incidence of severe infections. Unluckily, there are not experimental models that mimic the main findings of AH in humans. To overcome this limitation, translational studies with human samples are required. We previously analyzed samples from patients with biopsy-proven AH. In these previous studies, we identified CXC chemokines as a potential therapeutic target for these patients. We expanded these previous observations by performing a high-throughout transcriptome analysis. Hepatic gene expression profiling was assessed by DNA microarray in patients with Alcoholic hepatitis (n=15) and normal livers (n=7).
Project description:Alcoholic hepatitis (AH) is the most severe form of alcoholic liver disease and occurs in patients with excessive alcohol intake It is characterized by marked hepatocellular damage, steatosis and pericellular fibrosis. Patients with severe AH have a poor short-term prognosis. Unfortunately, current therapies (i.e. corticosteroids and pentoxyphylline) are not effective in many patients and novel targeted therapies are urgently needed. The development of such therapies is hampered by a poor knowledge of the underlying molecular mechanisms. Based on studies from animal models, TNF alfa was proposed to play a pivotal role in the mechanisms of AH. Consequently, drugs interfering TNF alfa were tested in these patients. The results were disappointing due to an increased incidence of severe infections. Unluckily, there are not experimental models that mimic the main findings of AH in humans. To overcome this limitation, translational studies with human samples are required. We previously analyzed samples from patients with biopsy-proven AH. In these previous studies, we identified CXC chemokines as a potential therapeutic target for these patients. We expanded these previous observations by performing a high-throughout transcriptome analysis.
Project description:<p>Alcoholic hepatitis (AH) is a life-threatening condition characterized by profound hepatocellular dysfunction for which targeted treatments are urgently needed. Identification of molecular drivers is hampered by the lack of suitable animal models. By performing RNA sequencing in livers from patients with different phenotypes of alcohol-related liver disease (ALD), we describe the transcriptional programs involved in disease progression. We uncovered that development of AH is characterized by the defective activity of liver-enriched transcription factors (LETFs). The PPARG predicted activation state was found increased in early forms of ALD, while AH was associated by a marked decrease in HNF4A-dependent gene expression along with a marked expression of the fetal HNF4A isoform (P2). TGFB1, a key upstream transcriptome regulator in AH, induced the use of HNF4a P2 promoter in hepatocytes, which resulted in abnormal bile acid synthesis and defective metabolic and synthetic functions. PPARG agonists partially prevented this effect. We conclude that targeting TGFB1 and epigenetic drivers that modulate HNF4A-dependent gene expression could be beneficial to improve hepatocellular function in patients with AH.</p> <p>The study was conducted thanks to a multicenter collaboration under the National Institute of Alcohol Abuse and Alcoholism (NIAAA)-funded consortium: <b>Integrated Approaches for Identifying Molecular Targets in Alcoholic Hepatitis</b> (InTEAM).</p>
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: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: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:Alcoholic hepatitis (AH) is characterized by severe liver and systemic inflammation and high mortality. Although numerous studies correlated neutrophil counts with poor clinical outcomes, the role of neutrophils in AH is poorly understood. Here, we report that neutrophils contribute to liver damage through increased neutrophils extracellular traps (NET) production in AH patients and mouse models with a concordant significant increase of low-density neutrophils (LDNs) in AH patients. Transcriptome analysis revealed that high-density neutrophils (HDNs) are activated and more prone to release NET, whereas LDNs exhibit exhausted phenotype. We show that alcohol-induced NET release in HDNs induces a unique LDN subset with decreased functionality and reduced clearance. Elimination of both defective HDNs and LDNs through in vivo neutrophil depletion or prevention of NET production with granulocyte colony stimulating factor (G-CSF) treatment ameliorate alcohol-induced liver damage. Our findings uncover alcohol-induced neutrophil phenotypic changes and provide mechanistic insights for therapeutic interventions in AH.
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:Background and aims: Liver is a major target organ for alcohol-induced disease and the spectrum of pathological states elicited by alcohol in liver comprises steatosis, alcoholic steatohepatitis, progressive fibrosis and cirrhosis, conditions that may progress to hepatocellular carcinoma. Many experimental animal models of alcoholic steatohepatitis exist that vary in duration, mode of alcohol administration and the degree and types of liver injury produced. While most of these models, regardless whether alcohol is administered through liquid diet or intragastrically, produce steatohepatitis and mild fibrosis, it is widely acknowledged that these models fail to fully recapitulate key characteristics of severe forms of alcoholic liver disease, such as alcoholic hepatitis. Recent studies attempted to combine alcohol and fibrosis and achieved promising results in mouse models that achieve some of the key features of alcoholic liver disease accompanied by exacerbated fibrosis and acute renal injury. This study combined a chronic cholestatic liver fibrosis model induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) with a mouse model of intragastric alcohol feeding. Methods: Adult male C57BL6/J mice were treated with 3,5-diethoxycarbonyl-1,4-dihydrocolidine (DDC) containing diet (0.05% w/w) to induce chronic liver fibrosis. Following DDC-induced fibrogenesis, ethyl alcohol (EtOH) (up to 27 g/ kg/day, up to 28 days) was administered continuously to mice via a gastric feeding tube (Tsukamoto-Frenchmodel of alcoholic liver disease). Results: Exposure to DDC or EtOH alone resulted in liver fibrosis or steatosis, respectively. Combined treatment with DDC and EtOH lead to an additive effect on liver injury, as evident by the development of hepatic inflammation, steatosis, and pericellular fibrosis, and by increased serum transaminase levels, compared to mice treated with either agent alone. Liver transcriptomic changes specific to combined treatment group included pathways involved in the cell cycle and DNA damage. Analyses of feces from these mice revealed alcohol-associated changes to the bile acid profile and gut microbiome. Conclusions: Mice treated with DDC and EtOH displayed several key characteristics of human alcoholic hepatitis, including pericellular fibrosis, increased hepatic bacterial load with dysbiosis, reduced capacity of the microbiome to synthesize secondary bile acids.
Project description:Purpose: We recently demonstrated that alcoholic hepatitis (AH) is characterized by de-differentiation of hepatocytes and loss of mature functions. Glucose metabolism is tighly regulated in healthy hepatocytes. We hypothesize that AH may lead to metabolic reprogramming of the liver, including dysregulation of glucose metabolism. Methods: We performed integrated metabolomic and transcriptomic analyses of liver tissue from patients with AH (n=13), alcoholic cirrhosis (n=10) or normal liver tissue from hepatic resection (n=16). Focused analyses of chromatin immunoprecipitation coupled to DNA sequencing (ChIP-seq) was performed. Functional in vitro studies were performed in primary rat and human hepatocytes and HepG2 cells. Results: Patients with AH exhibited specific changes in the levels of intermediates of glycolysis/gluconeogenesis, the TCA cycle, and monosaccharide and disaccharide metabolism. Integrative analysis of the transcriptome and metabolome revealed the utilization of alternate energetic pathways, metabolite sinks and bottlenecks, and improper glucose storage in AH patients. Among genes involved in glucose metabolism, hexokinase domain containing 1 (HKDC1) was identified as the most up-regulated kinase in AH patients. Histone active promoter and enhancer markers were increased in HKDC1 genomic region. High HKDC1 levels were associated with the development of acute kidney injury and decreased survival. Increased HKDC1 activity contributed to the accumulation of G6P and glycogen in primary rat hepatocytes. Conclusion: Altered metabolite levels and mRNA expression of metabolic enzymes suggest the existence of profound reprogramming of glucose metabolism in AH. Increased HKDC1 expression may contribute to dysregulated glucose metabolism and may serve as a novel biomarker and therapeutic target for AH.