Identifying Dihydropyrimidine Dehydrogenase as a Novel Regulator of Hepatic Steatosis
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE201169 | GEO | 2022/04/25
REPOSITORIES: GEO
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Project description:Background: Ginseng flower bud (GFB) is a part of ginseng with high content of ginsenosides, the known active components of ginseng. While the scientific data for the pharmacological activity of ginseng roots are accumulating, the therapeutic potential of GFB have been neglected. The current study aimed to examine the therapeutic effect of GFB on hepatic steatosis and to elucidate the underlying mechanisms. Methods: HepG2 cells treated with free fatty acids mixture and hepatocytes isolated from rats after 3 weeks of HFD feeding were used as in vitro models of hepatic steatosis for evaluation of anti-steatotic effect of GFB. The effect of GFB was further investigated in pathological conditions of hepatic steatosis induced by 12 weeks of HFD feeding in C57BL/6J mice. We performed systematical analyses on hepatic gene expression profiles in GFB treated mice. The effect of GFB on the expression profile of selected genes was validated by quantitative PCR. Results: GFB treatment markedly reduced oil red O stained lipid droplets and intracellular triglyceride levels in HepG2 cells and rat hepatocytes. In HFD-fed mice, GFB (500 mg/kg) treatment markedly reduced histological signs of hepatic steatosis and decreased hepatic triglyceride content by 34.1% compared to those of HFD. These changes by GFB treatment were accompanied by improved insulin signaling. Global gene expression analysis revealed that hepatic gene expression in the steatotic liver was reversed by GFB treatment, and the GFB-regulated genes are involved in immune process, insulin response and lipid storage. Conclusion: These findings provide a substantial evidence for the medicinal use of GFB in prevention or treatment of NAFLD through suppression of hepatic inflammation and fatty acid uptake while sensitizing hepatic insulin signaling
2021-01-01 | GSE142059 | GEO
Project description:Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease. Although genetic predisposition and epigenetic factors contribute to the development of NAFLD, our understanding of the molecular mechanism involved in the pathogenesis of the disease is still emerging. Here we investigated a possible role of a microRNAs-STAT3 pathway in the induction of hepatic steatosis. Differentiated HepaRG cells (dHepaRG) treated with the fatty acid sodium oleate recapitulated features of liver vesicular steatosis and activated a cell-autonomous inflammatory response, inducing STAT3-Tyrosine-phosphorylation. With a genome-wide approach (Chromatin Immunoprecipitation Sequencing), many phospho-STAT3 binding sites were identified in fatty dHepaRG and several STAT3 and/or NAFLD-regulated microRNAs showed increased expression levels, including miR-21. Innovative CARS (Coherent Anti-Stokes Raman Scattering) microscopy revealed that chemical inhibition of STAT3 activity decreased lipid accumulation and deregulated STAT3-responsive microRNAs, including miR-21, in lipid overloaded dHepaRG cells. We were able to show in vivo that reducing phospho-STAT3-miR-21 levels in C57/BL6 mice liver, by long-term treatment with metformin, protected mice from aging dependent hepatic vesicular steatosis. Our results identified a microRNAs-phosphoSTAT3 pathway involved in the development of hepatic steatosis, which may represent a molecular marker for both diagnosis and therapeutic targeting.
2018-09-25 | GSE89157 | GEO
Project description:Background & Aims: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common complication of obesity with a hallmark feature of hepatic steatosis. Recent data from animal models of MALFD have demonstrated substantial changes in macrophage composition in the fatty liver. In humans, the relationship between liver macrophage heterogeneity and liver steatosis is less clear. Methods: Liver tissue from 21 participants was collected at time of bariatric surgery and analyzed using flow cytometry, immunofluorescence, and H&E microscopy. Single-cell RNA sequencing was also conducted on a subset of samples (n=3). Intrahepatic triglyceride content was assessed via MRI and tissue histology. Mouse models of hepatic steatosis were used to investigate observations made from human liver tissue. Results: We observed variable degrees of liver steatosis with minimal fibrosis in our participants. Single-cell RNA sequencing revealed four macrophage clusters that exist in the human fatty liver encompassing Kupffer cells (KC) and monocyte-derived macrophages (MdM). The genes expressed in these macrophage subsets were similar to those observed in mouse models of MAFLD. Hepatic CD14+ monocytes/macrophage number correlated with the degree of steatosis. Using mouse models of early liver steatosis we demonstrate recruitment of MdMs precedes KC loss and liver damage and that MdMs may serve a role in lipid uptake during MAFLD. Conclusions: The human liver in MAFLD contains macrophage subsets that align well with those that appear in mouse models of fatty liver disease. Recruited myeloid cells correlate well with the degree of liver steatosis in humans and this occurs prior to changes in KC number. MdMs appear to have a role in lipid uptake during early stages of MALFD.
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