Project description:Our objective is to determine the role of myeloid FoxO1 in regulating hepatic lipid metabolism and its contribution to nonalcoholic steatohepatitis (NASH) in mice. We generated mice with conditional FoxO1 depletion in myeloid cells, using the FoxO1-LoxP/LysM-Cre system. We then fed myeloid cell-conditional FoxO1-knockout and wild-type male mice a NASH-inducing diet for 25 weeks. Then mice in both groups were euthanized and the liver tissues were procured for the preparation of total RNAs, which were subjected to RNA-seq assay. While myeloid FoxO1 was upregulated in animal models and human subjects with NASH, the underlying mechanism is poorly understood. We found that myeloid cell conditional FoxO1-knockout mice were protected from developing NASH, culminating in the reduction of hepatic inflammation, steatosis and fibrosis. Mechanistically, FoxO1 counteracts Stat6 to skew macrophage polarization from M2 toward M1 signatures to perpetuate hepatic inflammation in NASH. FoxO1 appears as a pivotal mediator of macrophage activation in response to overnutrition and a therapeutic target for ameliorating hepatic inflammation to stem the disease progression from benign steatosis to NASH.
Project description:The genomic landscape of hepatic tissue affected by nonalcoholic steatohepatitis (NASH) in severely obese adolescents undergoing bariatric surgery is unknown. Our purpose here was to uncover genomic profiles of obese controls, and obese cases with nonalcoholic fatty liver disease (NAFLD), borderline nonalcoholic steatohepatitis, and definite nonalcoholic steatohepatitis, in order to clarify molecular functions, biological processes, and pathways that are dysregulated in nonalcoholic steatohepatitis in the severely obese adolescent. In a prospective observational cohort study, we have intra-operatively obtained 165 liver samples; of these 67 were submited for microarray analysis. Through ANOVA, we found 8648 genes with differential regulation between the four histologies; from these, we uncovered gene signatures shared between borderline and definite nonalcoholic steatohepatitis, and gene sets with differential effects between borderline and definite.
Project description:To investigate the effects of AAV8-mediated overexpression of AGXT in mice with diet-induced nonalcoholic steatohepatitis compared to AAV8-GFP
Project description:Purpose: We investigated the tetrachloroethylene associated changes in kidney transcriptomes among healthy mice, nonalcoholic fatty liver disease mice, and nonalcoholic steatohepatitis mice.
Project description:Nonalcoholic steatohepatitis (NASH) is a progressive disorder with aberrant lipid accumulation and subsequent inflammatory and profibrotic response. Lipid reduction through cytoplasmic lipolysis might adversely worsen steatohepatitis, however, the effect of autophagic lipolysis, lipophagy, remains obscure. We engineered the adaptor protein to induce lipophagy with lipid droplet targeting signal and modified LC3 interacting region. Activating hepatocyte lipophagy obviously mitigated both steatosis and NASH pathology. Mechanistically, lipophagy promoted the excretion of lipid from liver via lysosomal exocytosis and attenuated harmful accumulation of nonesterified fatty acid. This exocytosis was dependent on Ca2+ signal unlike the lysosomal dysfunction-related exocytosis. High content compound screening identified alpelisib and digoxin, clinically-approved compounds, as effective activators of lipophagy. Administration of alpelisib or digoxin inhibited the transition to steatohepatitis in mice fed high fat with low methionine low choline diet. Given all these data, activating lipophagy may be a promising therapeutic approach to prevent NASH progression.
Project description:Non-alcoholic fatty liver disease (NAFLD) is the number one cause of chronic liver disease worldwide, with 25% of these patients developing nonalcoholic steatohepatitis (NASH). NASH significantly increases the risk of cirrhosis and decompensated liver failure. Past studies in rodent models have shown the knockout of glycine-N-methyltransferase (GNMT) results in rapid pro-gression of steatosis, fibrosis, and hepatocellular carcinoma. However, the attenuation of GNMT in subjects with NASH and the molecular basis for its impact on the disease process are still unclear. To address this knowledge gap, we show the reduction of GNMT protein levels in the liver of NASH subjects compared to healthy controls. To gain insight into the impact of decreased GNMT in the disease process, we performed global label-free proteome studies on the livers from a murine Western diet-based model of NASH. Histological and molecular characterization of the animal model demonstrate high resemblance to the human disease.
Project description:Nonalcoholic steatohepatitis (NASH) and associated liver fibrosis have limited therapy options. We report a novel adiponectin-based dual agonist for adiponectin receptors 1 and 2 with a longer half-life, and show that it ameliorates NASH and liver fibrosis in mouse models.