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: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.
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:Background and Aims: Nonalcoholic steatohepatitis (NASH) will soon become the leading cause of liver transplantation in the US and is also associated with increased COVID-19 mortality. Currently, there are no FDA approved drugs available that slow NASH progression or address NASH liver involvement in COVID-19. Since animal models cannot fully recapitulate human NASH, we hypothesized that stem cells isolated directly from end-stage NASH patient liver may address current knowledge gaps in human NASH pathology. Approach and Results: We devised methods allowing derivation, proliferation, hepatic differentiation and extensive characterization of bipotent ductal organoids from irreversibly damaged NASH patient liver. The transcriptomes of organoids derived from NASH liver, but not healthy liver show significant upregulation of pro-inflammatory and cytochrome p450-related pathways, as well as of known liver fibrosis and tumor markers, with the degree of upregulation being NASH patient-specific.
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: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:BACKGROUND & AIMS: Recent studies revealed that hemoglobin is expressed in some non-erythrocytes and it suppresses oxidative stress when overexpressed. Oxidative stress plays a critical role in the pathogenesis of non-alcoholic steatohepatitis (NASH). This study was to investigate whether hemoglobin is expressed in hepatocytes and how it is related to oxidative stress in NASH patients. METHODS: Microarray was performed to identify differentially expressed genes in NASH. Quantitative real time PCR (qRT-PCR) was used to examine gene expression levels. Western blotting and immunofluorescence staining were employed to examine hemoglobin proteins. Flow cytometry was used to measure intracellular oxidative stress. RESULTS: Analysis of microarray gene expression data has revealed a significant increase in the expression of hemoglobin alpha (HBA1) and beta (HBB) in liver biopspies from NASH patients. Increased hemoglobin expression in NASH was validated by qRT-PCR. However, the expression of erythrocyte specific marker genes such as SPTA, SPTB, GYPA, GATA1, and ALAS2 did not change, indicating that increased hemoglobin expression in NASH was not from erythropoiesis, but could result from increased expression in hepatocytes. Immunofluorescence staining demonstrated positive HBA1 and HBB expression in the hepatocytes of NASH livers. Hemoglobin expression was also observed in human hepatocellular carcinoma HepG2 cell line. Furthermore, treatment with hydrogen peroxide, a known oxidative stress inducer, induced a dose dependent increase in HBA1 expression in HepG2 cells. Intriguingly, forced hemoglobin expression suppressed oxidative stress. CONCLUSIONS: Oxidative stress upregulates hemoglobin expression in hepatocytes. Suppression of oxidative stress by hemoglobin could be a mechanism to protect hepatocytes from oxidative damage. These findings suggest that hemoglobin is an inducible antioxidant in hepatocytes in response to increased oxidative stress as found in NASH livers. Twelve biopsy diagnosed NASH patients were included in this study. For control groups, total RNA from 5 different subjects were purchased from ADMET. These subjects are free from liver disease.
Project description:Non-alcoholic fatty liver disease (NAFLD) is a predominant form of chronic liver disease, affecting nearly 25 % of the global population. The progression from steatosis to nonalcoholic steatohepatitis (NASH) in NAFLD patients is one of the major causes of liver-related death worldwide. We assessed the miRNA expression profiles of the exosomes derived from the peripheral blood of NASH patients or healthy controls.
Project description:The mammalian liver comprises heterogeneous cell types within its tissue microenvironment that respond to physiological cues and undergo pathophysiological reprogramming in disease states, such as nonalcoholic steatohepatitis (NASH). Patients with NASH are at increased risk for the development of hepatocellular carcinoma (HCC). However, the molecular and cellular nature of liver microenvironment remodeling that links NASH to liver carcinogenesis remains obscure. Here we show that diet-induced NASH is characterized by induction of tumor-associated macrophage (TAM)-like macrophages and exhaustion of cytotoxic T cells in mouse liver. The adipose-derived endocrine factor Neuregulin 4 (NRG4) serves as a hormonal checkpoint that restrains this pathological reprogramming during NASH. NRG4 deficiency exacerbates the induction of tumor-prone liver immune microenvironment and NASH-associated HCC, whereas transgenic NRG4 overexpression elicits protective effects in mice. In a therapeutic setting, recombinant NRG4 protein exhibits remarkable efficacy in inhibiting HCC in mice with NASH, thereby paving the way for future therapeutic development.
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.