Background: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease in both children and adults; however, the exact pathogenesis of NAFLD remains obscure. Accumulating evidence supports the effects of miRNA in the lipid metabolism and the regulation of insulin resistance, providing a potential linkage between the miRNA and NAFLD.
Objective and Hypotheses: The aims of this study were to explore microRNA (miRNA) expression profiles in NAFLD, and to explore the function of miR-152 on the development of NAFLD in HepG2 cells.
Method: SpragueDawley rats feeding a high-fat diet (HFD) for 4 and 12 weeks were used to establish a rat model of NAFLD. The miRNA expression profile of liver tissue was determined at 12 weeks by deep sequencing, and computational algorithms were used for target prediction. Selected miRNAs were then validated by stem-loop RT-PCR at both 4- and 12-week timepoints; furthermore, the expression level of these miRNAs was also assessed in HepG2 cells. Real time RT-PCR, function study of miRNA, lentiviral transduction, western blot, 3′UTR luciferase reporter assays, and other techniques were employed for target verification.
Results: Our miRNA deep sequencing analysis identified 16 known upregulated miRNAs (fold change >1.5)and 12 downregulated miRNAs (fold change <0.5). Among the abnormal expressed miRNAs, miR-200a, miR-200b, miR-200c, miR-146a, miR-146b, and miR-152 were upregulated in both models by RT-PCR, as the same as what had been found in deep sequencing. Further analysis confirmed that miR-152 bound directly to the 3′UTR of the Wnt10b and promoted hepatic steatosis through Wnt10b downregulation. The miR-152/Wnt10b axis mediated hepatic steatosis through increased peroxisome proliferator-activated receptor β (PPAR β). Mitochondrial dysfunction was induced by the overexpression of miR-152.
Conclusion: miRNAs may play a critical role in the pathogenesis of NAFLD, and miR-152/Wnt10b pathway could be a potential target for NAFLD prevention and treatment.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology