miR-182-5p Attenuates High-Fat -Diet-Induced Nonalcoholic Steatohepatitis in Mice

Introduction and aim. Patients with NASH have increased risk for sepsis or cardiovascular disease after Liver transplantation. An important role of Toll-like receptor (TLR) 4 in the pathogenesis of nonalcoholic steatohepatitis (NASH) was demonstrated. Here, we study the role of miR-182-5p in TLR4 expression and high-fat-diet (HFD)-induced NASH in vitro and in vivo. Material and methods. Following transfection with a miR-182-5p mimic, the effect of miR-182-5p on TLR4 in RAW264.7 and HepG2 cells was investigated. Following administration of the miR-182-5p mimic into the livers of HFD-induced NASH mice, we determined the in vivo expression of TLR4, TNF alpha, and IL-6 and assessed the histologic features of the livers. Results. Following lipopolysaccharide (LPS) treatment of RAW264.7 cells, real-time RT-PCR and western blot results indicated decreases levels of TLR4 mRNA and protein in the miR-182-5p group as compared with levels observed in controls, with similar trends were observed in TNF alpha and IL-6 protein levels. Following oleic acid (OA) treatment of HepG2 cells, TLR4, TNF alpha, and IL-6 levels were significantly decreased in the miR-182-5p group as compared with levels observed in controls. Following miR-182-5p administration, TLR4 mRNA and protein levels decreased along with those of TNF alpha and IL-6 proteins, and the liver weight/body weight ratio of treated mice was less than that observed in controls. Furthermore, hematoxylin and eosin staining showed that the miR-182-5p-treated group exhibited low adipose-cell cross-sectional areas, and Oil Red O staining showed decreases in the size of lipid droplets in the miR-182-5p-treated group. Conclusions. miR-182-5p ameliorated HFD-induced NASH by suppressing TLR4.