MiR-19a Affects Hepatocyte Autophagy via Regulating lncRNA NBR2 and AMPK/PPAR in D-GalN/Lipopolysaccharide-Stimulated Hepatocytes

This study aims to evaluate the potential involvement and regulatory mechanism of miR-19a in hepatocytes autophagy of acute liver failure (ALF). The in vitro hepatocytes injury model of primary hepatocyte and hepatocytes line HL-7702 was established by D-galactosamine (D-GalN) and lipopolysaccharide (LPS) co-treatment. Relative expression level of miR-19a and NBR2 was determined by qRT-PCR. Protein expression of AMPK/PPAR and autophagy-related gene was determined by Western blot. In hepatic tissue of 20 ALF patients and D-GalN/LPS-stimulated hepatocytes, miR-19a was upregulated and NBR2 was downregulated. D-GalN/LPS stimulation caused the inactivation of AMPK/PPAR signaling and the decrease of autophagy-related LC3-II/LC3-I ratio and beclin-1 expression in hepatocytes. The expression of both AMPK/PPAR and NBR2 were negatively controlled by miR-19a overexpression or knockdown. Moreover, both NBR2 and PPAR were targeted regulated by miR-19a according to luciferase reporter assay. In D-GalN/LPS-stimulated hepatocytes, AMPK activation promoted PPAR expression. AMPK inactivation inhibited the pro-autophagy effect of miR-19a and caused the decrease of LC3-II/LC3-I ratio and beclin-1 expression. PPAR activation abrogated the anti-autophagy effect of miR-19a mimic and caused the increase of LC3-II/LC3-I ratio and beclin-1 expression. NBR2 knockdown reversed the anti-autophagy impact of miR-19a inhibitor and caused the decrease of LC3-II/LC3-I ratio and beclin-1 expression. In summary, our data suggested that miR-19a negatively controlled the autophagy of hepatocytes attenuated in D-GalN/LPS-stimulated hepatocytes via regulating NBR2 and AMPK/PPAR signaling. J. Cell. Biochem. 119: 358-365, 2018. (c) 2017 Wiley Periodicals, Inc. Our data suggested that miR-19a negatively controlled autophagy of hepatocytes attenuated in D-GalN/LPS-stimulated hepatocytes via targeted regulating NRB2 and AMPK/PPAR signaling.