Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, P.R. China.
Anhui Provincial Engineering Research Center for Polysaccharide Drugs, School of Pharmacy, Wannan Medical College, Wuhu 241002, P.R. China.
Biosci Rep. 2019 Jul 15;39(7). doi: 10.1042/BSR20181722. Print 2019 Jul 31.
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. and 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. 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. 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.
作为全球最常见的肝脏疾病之一,非酒精性脂肪性肝病 (NAFLD) 始于肝脏中甘油三酯 (TG) 的异常积累。长链非编码 RNA-H19 被报道可调节 NAFLD 中的肝代谢稳态。然而,其 NAFLD 的分子机制尚不完全清楚。分别通过游离脂肪酸 (FFA) 处理肝细胞和高脂喂养小鼠建立了 NAFLD 模型。苏木精和伊红 (H&E) 和油红 O 染色检测肝组织形态和脂质积累。免疫组织化学 (IHC) 染色检测肝组织中过氧化物酶体增殖物激活受体 γ (PPARγ) 水平。酶联免疫吸附试验 (ELISA) 测定 TG 分泌。荧光素酶测定和 RNA 下拉用于验证 H19、miR-130a 和 PPARγ 之间的调节机制。通过定量实时 PCR (qRT-PCR) 和 Western blot 检测肝细胞和肝组织中的基因表达。H19 和 PPARγ 在 NAFLD 小鼠和细胞模型中上调,而 miR-130a 下调。H&E 和油红 O 染色表明脂质积累增加。FFA 诱导的肝细胞中 H19 的敲低抑制了脂肪变性和 TG 分泌。H19 可以与 miR-130a 结合,而 miR-130a 可以直接抑制 PPARγ 的表达。同时,miR-130a 通过下调与 NAFLD 相关的基因 PPARγ、SREBP1、SCD1、ACC1 和 FASN 来抑制脂质积累。miR-130a 的过表达和 PPARγ 拮抗剂 GW9662 抑制脂肪生成和 TG 分泌,而 PPARγ 激动剂 GW1929 逆转了 miR-130a 上调引起的这种变化。H19 的敲低通过直接调节 miR-130a/PPARγ 轴减轻肝脂肪生成,这是 H19 在调节 NAFLD 中的新的机制作用。