应用肝特异性敲除小鼠探讨LRP16在非酒精性脂肪肝病发生中的机制

The worldwide prevalence of nonalcoholic fatty liver disease(NAFLD) is likely to increase in the future. Hepatocellular accumulation of free fatty acids (FFAs) in the form of triglycerides constitutes the metabolic basis for the development of NAFLD，but the specific molecular mechanism responsible was unclear. LRP16 is a novel gene which was cloned in our laboratory. It has been shown that LRP16 might cause insulin resistance, which is the major contributor of NAFLD. Recently, we initially found hepatic steatosis and TG levels were significantly increased in high-fat-fed mice .Elevated hepatic LRP16 in high-fat-fed mice was associated with the change of expression of fatty acids metabolism related enzymes. Overexpression of LRP16 enhanced fatty acid synthesis-associated genes such as sterol regulatory element-binding protein-1c (SREBP1c)，suggesting that LRP16 may be the key regulatory molecule in the progress of NAFLD. The aim of this proposal is to investigate the mechanistic role of LRP16 in the development of hepatic fatty acid metabolism in cells and mice by using Conditional Knockout, Adenovirus, ChIP and luciferase gene report system etc. The findings will provide useful data to understand the mechanism of NAFLD formation and identify potential new targets for preventing NAFLD in humans.

非酒精性脂肪肝（NAFLD）发病率日益增多。脂肪酸代谢紊乱可导致肝细胞内脂肪异常堆积，但其具体分子机制不明。LRP16 是本实验室首先克隆的一个基因， 既往研究表明LRP16可导致胰岛素抵抗，而胰岛素抵抗是非酒精性脂肪肝的主要病理基础。近期，我们初步发现高脂喂养小鼠出现脂肪变性，同时伴有 LRP16和脂肪酸代谢相关酶类的改变。过表达LRP16导致SREBP1表达增加。提示LRP16 可能通过调控肝脏的脂肪酸代谢，进而导致非酒精性脂肪肝的发生。本项目拟采用条件性敲除基因、腺病毒转染、染色质免疫共沉淀和荧光素酶报告基因等方法，从细胞、动物不同水平探讨LRP16在肝脏脂肪酸代谢中的作用， 并为阐明NAFLD的发生机制，寻找新的治疗靶点提供理论依据。

非酒精性脂肪肝（NAFLD）发病率日益增多。脂肪酸代谢紊乱可导致脂肪异常堆积，但是具体机制不明。LRP16 是本实验室首先克隆的一个基因，本项目采用CRISPR/Cas9条件性敲除基因、慢病毒转染、超高效液相色谱法和分子生物学等方法，从细胞、动物不同水平探讨LRP16在肝脏脂肪酸代谢中的作用。研究发现抑制LRP16表达可以导致甘油三酯（TG）的沉积，但是没有导致SREBP1及其下游酶类表达的改变。提示LRP16影响肝脏TG沉积另有其他机制。对这一机制的进一步探讨，有助于阐明NAFLD的发生机制，为寻找新的治疗靶点提供理论依据。