LncRNA-H19 promotes hepatic lipogenesis by directly regulating miR-130a/PPARγ axis in non-alcoholic fatty liver disease.

Jun Liu,Guo-Dong Wang,Bo Liu,Tao Tang

doi:10.1042/bsr20181722

Abstract

Background: As one of the most common liver disorders worldwide, non-alcoholic fatty liver disease (NAFLD) begins with the abnormal accumulation of triglyceride (TG) in the liver. Long non-coding RNA-H19 was reported to modulate hepatic metabolic homeostasis in NAFLD. However, its molecular mechanism of NAFLD was not fully clear.Methods: In vitro and in vivo models of NAFLD were established by free fatty acid (FFA) treatment of hepatocytes and high-fat feeding mice, respectively. Hematoxylin and Eosin (H&E) and Oil-Red O staining detected liver tissue morphology and lipid accumulation. Immunohistochemistry (IHC) staining examined peroxisome proliferator-activated receptor γ (PPARγ) level in liver tissues. ELISA assay assessed TG secretion. Luciferase assay and RNA pull down were used to validate regulatory mechanism among H19, miR-130a and PPARγ. The gene expression in hepatocytes and liver tissues was detected by quantitative real-time PCR (qRT-PCR) and Western blotting.Results: H19 and PPARγ were up-regulated, while miR-130a was down-regulated in NAFLD mouse and cellular model. H&E and Oil-Red O staining indicated an increased lipid accumulation. Knockdown of H19 inhibited steatosis and TG secretion in FFA-induced hepatocytes. H19 could bind to miR-130a, and miR-130a could directly inhibit PPARγ expression. Meanwhile, miR-130a inhibited lipid accumulation by down-regulating NAFLD-related genes PPARγ, SREBP1, SCD1, ACC1 and FASN. Overexpression of miR-130a and PPARγ antagonist GW9662 inhibited lipogenesis and TG secretion, and PPARγ agonist GW1929 reversed this change induced by miR-130a up-regulation.Conclusion: Knockdown of H19 alleviated hepatic lipogenesis via directly regulating miR-130a/PPARγ axis, which is a novel mechanistic role of H19 in the regulation of NAFLD.

Highlights

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver disorders worldwide, which is often related with an unhealthy diet, type 2 diabetes and obesity [1,2]
Hematoxylin and Eosin (H&E) staining of liver tissues showed enlarged hepatocyte volume and dispersion of lipid vacuoles in model group compared with control group (Figure 1A), and Oil-Red O staining showed remarkable deposition of lipid droplet with liver (Figure 1B), indicating an increased hepatic lipid accumulation
QRT-PCR assay revealed that H19 as well as non-alcoholic fatty liver disease (NAFLD)-related genes (PPARγ, ACC1, SCD1, fatty acid synthase (FASN) and SREBP1) were significantly increased in the liver of high-fat diet (HFD) mice compared with control group (Figure 1D), while miR-130a was down-regulated in the liver of HFD mice

Summary

Introduction

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver disorders worldwide, which is often related with an unhealthy diet, type 2 diabetes and obesity [1,2]. NAFLD begins with the abnormal accumulation of triglyceride (TG) in the liver and can develop to cirrhosis and even hepatocellular carcinoma (HCC) [2,3]. As one of the most common liver disorders worldwide, non-alcoholic fatty liver disease (NAFLD) begins with the abnormal accumulation of triglyceride (TG) in the liver. Hematoxylin and Eosin (H&E) and Oil-Red O staining detected liver tissue morphology and lipid accumulation. Luciferase assay and RNA pull down were used to validate regulatory mechanism among H19, miR-130a and PPARγ. H19 could bind to miR-130a, and miR-130a could directly inhibit PPARγ expression. MiR-130a inhibited lipid accumulation by down-regulating NAFLD-related genes PPARγ, SREBP1, SCD1, ACC1 and FASN. Conclusion: Knockdown of H19 alleviated hepatic lipogenesis via directly regulating miR-130a/PPARγ axis, which is a novel mechanistic role of H19 in the regulation of NAFLD

Methods

Results

Conclusion