Project description:C57BL/6 mice are the most widely used inbred strain for metabolic and interventional studies. It is commonly known that high-caloric diet feeding induces a heterogeneous phenotype in C57BL/6 mice similar to humans with the majority developing obesity and metabolic dysfunction whilst others remaining lean and metabolically healthy. Nevertheless, the underlying mechanism(s) for this remains unknown. Here, we show that a subset (5-25%) of all C57BL/6 mice develop spontaneous cholemia with elevated total serum bile acids and increased liver damage at early time points upon high-caloric diet feeding. Although cholemic mice are resistant to obesity and metabolic dysfunction, they develop accelerated liver damage and liver fibrosis, which ultimately predisposes them to early liver cancer compared to non-cholemic mice fed a Western-diet or choline-deficient high-fat diet. Hitherto, these mice have been overlooked, which may have led to inconsistent or perplexing findings. Therefore, C57BL/6 mice included in metabolic and cancer studies relating to the liver are strongly recommended to be screened and excluded for cholemia.
Project description:Nonalcoholic steatohepatitis (NASH) is a progressive liver disease that is characterized by liver injury, inflammation and fibrosis. NASH pathogenesis is linked to reprogramming of chromatin landscape in the liver that predisposes hepatocytes to stress-induced tissue injury. However, the molecular nature of the putative checkpoint that maintains chromatin architecture and preserves hepatocyte health remains elusive. Here we show that heterogeneous nuclear ribonucleoprotein U (hnRNPU), a nuclear matrix protein that governs chromatin architecture and gene transcription, is a critical factor that couples chromatin disruption to NASH pathogenesis. RNA-seq and ChIP-seq studies revealed an extensive overlap between hnRNPU occupancy and altered gene expression during NASH. Hepatocyte-specific inactivation of hnRNPU disrupted liver chromatin accessibility, activated the molecular signature of NASH and sensitized mice to diet-induced NASH pathogenesis. Mechanistically, hnRNPU deficiency stimulated the expression of a truncated isoform of TrkB that promotes inflammatory signaling in hepatocytes and stress-induced cell death. These findings illustrate a novel mechanism through which disruptions of chromatin architecture drive the emergence of disease-specific signaling patterns that promote liver injury and exacerbate NASH pathogenesis.
Project description:To investigate the mechanism of hepatic Activin A and Gpnmb in NAFLD/NASH, we studied C57BL/6J mice on a FPC NASH diet and sugar water for 16 weeks, compared with standard chow diet, and used adeno-associated viral vectors with a liver-specific thyroxine binding globulin (TBG) promoter to express Activin A or GFP (control), or AAV8-H1-shRNA to knockdown of Gpnmb or scramble control in NAFLD/NASH liver. We then performed gene expression profiling analysis using data obtained from RNA-seq of 3 different livers in each group.
Project description:Non-alcoholic fatty liver disease (NAFLD) is characterized by a series of pathological changes that can progress from simple fatty liver disease to non-alcoholic steatohepatitis (NASH). The objective of this study is to describe changes in global gene expression associated with the progression of NAFLD. This study is focused on the expression levels of genes responsible for the absorption, distribution, metabolism and excretion (ADME) of drugs. Differential gene expression between three clinically defined pathological groups; normal, steatosis and NASH was analyzed. The samples were diagnosed as normal, steatotic, NASH with fatty liver (NASH fatty) and NASH without fatty liver (NASH NF). Genome-wide mRNA levels in samples of human liver tissue were assayed with Affymetrix GeneChipM-. Human 1.0ST arrays
Project description:Recent studies have revealed the pivotal role of gut microbiota in the precession of liver diseases including non-alcoholic steatohepatitis (NASH). Many natural herbs, such as Gynostemma pentaphyllum (GP), have been extensively used applied in the treatment prevention of NASH, while the bioactive components and underlying mechanism remain unclear. The aim of this study was to investigate whether the polysaccharides of GP (GPP) has the protective effect on of NASH and to explore the potential mechanism underlying these effects. To investigate the function high dose of GPP(HGPP) in the regulation of hepatic gene expression, C57BL/6 male mice were fed with methionine-choline-deficient (MCD) diet for 4 weeks to induce NASH, and administered daily oral gavage of the sodium carboxymethylcellulose (CMC-Na) for model group, HGPP for experimental group, compared with normal control methionine-choline-sufficient (MCS) group.
Project description:Non-alcoholic steatohepatitis (NASH) is a fatty liver disease that does not involve alcohol consumption and is characterized by fatty degeneration, inflammation, and hepatocellular damage. Therefore, predicting future fibrosis is necessary in the early stages of NASH to prevent developing diseases. This study examined histological changes in the liver as well as microRNA expression changes in the liver and serum of NASH mice model to search for potential biomarker candidates that may predict early fibrosis. This study used 6-week-old C57BL/6NJcl male mice and fed the control and NASH groups with a food-breeding solid diet (CE-2) and a high-fat diet (choline-deficient high-fat and 0.1% [w/v] methionine supplemented diet), respectively. We used Agilent Technologies miRNA microarray to examine microRNA expression in the liver and serum.
Project description:We performed RNA-seq analysis of pooled RNA extracted from liver of mice fed normal chow (control), WDF (NASH), and WDF+TH (TH-treated NASH).
Project description:Non-alcoholic fatty liver disease (NAFLD) is a leading form of chronic liver disease with large unmet need. Non-alcoholic steatohepatitis (NASH), a progressive variant of NAFLD, can lead to fibrosis, cirrhosis, and hepatocellular carcinoma. To identify potential new therapeutics for NASH, we used a computational approach based on Connectivity Map (CMAP) analysis, which pointed us to a potential application of bromodomain and extra-terminal motif (BET) inhibitors for treating NASH. To experimentally validate this hypothesis, we tested a small-molecule inhibitor of the BET family of proteins, GSK1210151A (I-BET151), in the STAM mouse NASH model at two different dosing timepoints (onset of NASH and onset of fibrosis) to assess its potential effectiveness for the treatment of NASH and liver fibrosis. I-BET151 decreased the non-alcoholic fatty liver disease activity score (NAS), a clinical endpoint for assessing the severity of NASH, as well as progression of liver fibrosis and interferon-γ expression. Transcriptional characterization through RNA-sequencing pointed to alterations in molecular mechanisms related to interferon signaling and cholesterol biosynthesis following treatment, as well as reversal of gene expression patterns linked to fibrotic markers. Altogether, these results suggest that inhibition of BET proteins may present a novel therapeutic opportunity in the treatment of NASH and liver fibrosis.
Project description:Gene expression profiling reveals a potential role of isorhamnetin in the mitigation of NASH features including steatosis, liver injury, and fibrosis Microarray gene expression profiling was conducted for technical replicates of healthy liver as control (CTL), NASH-induced (NASH), NASH-induced treated with isorhamnetin for 14 days (50 mg/kg of body weight) (NASH+ISO) liver tissues to identify its effect in the regulation of pathways involved in pathologic features of NASH.
Project description:Human genetic studies have identified several MARC1 variants as protective against non-alcoholic fatty liver diseases (NAFLD). The MARC1 variants are associated with reduced lipid profiles, liver enzymes, and liver-related mortality. However, the role of mitochondrial amidoxime reducing component 1 (mARC1), encoded by MARC1, in NAFLD is still unknown and the therapeutic potential of this target has never been developed. Given that mARC1 is mainly expressed in hepatocytes, we developed an N-acetylgalactosamine conjugated mouse mARC1 siRNA to address this. In ob/ob mice, knockdown of mARC1 in mouse hepatocytes resulted in decreased liver weight, serum lipid enzymes, low-density lipoprotein cholesterol, and liver triglycerides. Loss of mARC1 also improved the lipid profiles and attenuated liver pathological changes in two diet-induced nonalcoholic steatohepatitis (NASH) mouse models. A comprehensive analysis of mARC1-deficient liver in NASH by metabolomics, proteomics, and lipidomics showed that mARC1 knockdown partially restored metabolites and lipids altered by diets. Taken together, loss of mARC1 protects mouse liver from NASH, suggesting a potential therapeutic approach of NASH by downregulation of mARC1 in hepatocytes.