Abstract：
Investigating and identifying pathogenic molecules of non-alcoholic fatty liver disease (NAFLD) has become imperative, which would serve as effective targets in the future. We established high-fat diet (HFD)-induced NAFLD model in mice and palmitic acid (PA)-induced model in mouse AML12 cells. The level of miR-218-5p was examined by qRT-PCR, and Elovl5 was identified as the potential target gene of miR-218-5p. The binding relationship between miR-218-5p and Elovl5 was validated by double luciferase reporter gene assay, and inhibition/overexpression of miR-218-5p in vitro. The functional mechanisms of miR-218-5p/Elovl5 in regulating lipogenesis in NAFLD were investigated in vivo and in vitro through gain- and loss-of-function studies. MiR-218-5p was significantly increased, and Elovl5 was decreased in model group. According to the double luciferase reporter and gene interference experiments in AML12 cells, Elovl5 was a target gene of miR-218-5p and its expression was regulated by miR-218-5p. The SREBP1-mediated lipogenesis signaling pathway regulated by Elovl5 was upregulated in model group. Moreover, silencing of miR-218-5p significantly upregulated Elovl5 expression, and suppressed SREBP1 signaling pathway in PA-induced AML-12 cells. Correspondingly, the cell injury, elevated TC, TG contents and lipid droplet accumulation were ameliorated. Furthermore, the effect of miR-218-5p on lipogenesis in vitro and in vivo was obstructed by si-Elovl5, implicating that miR-218-5p promotes lipogenesis by targeting ELOVL5 in NAFLD. miR-218-5p could promote fatty acid synthesis by targeting Elovl5, thereby accelerating the development of NAFLD, which is one of the key pathogenic mechanisms of NAFLD and provides a new molecular target for the management of NAFLD.
摘要：
研究和鉴定非酒精性脂肪性肝病(NAFLD)的致病分子已成为当务之急,这将成为未来的有效目标。我们建立了高脂饮食（HFD）诱导的小鼠NAFLD模型和棕榈酸（PA）诱导的小鼠AML12细胞模型。通过qRT-PCR检测miR-218-5p的水平，Elovl5被鉴定为miR-218-5p的潜在靶基因。通过双荧光素酶报告基因检测验证miR-218-5p与Elovl5的结合关系,和miR-218-5p的体外抑制/过表达。miR-218-5p/Elovl5在NAFLD中调节脂肪生成的功能机制在体内和体外通过功能增益和功能丧失研究进行了研究。MiR-218-5p显著增加,模型组Elovl5降低。根据AML12细胞的双荧光素酶报告基因和基因干扰实验，Elovl5是miR-218-5p的靶基因,其表达受miR-218-5p调控。模型组Elovl5调控的SREBP1介导的脂肪生成信号通路上调。此外，沉默miR-218-5p显著上调Elovl5表达，并抑制PA诱导的AML-12细胞中的SREBP1信号通路。相应地,细胞损伤,TC升高，TG含量和脂滴积累得到改善。此外，si-Elovl5阻碍了miR-218-5p在体外和体内对脂肪生成的影响,提示miR-218-5p通过靶向NAFLD中的ELOVL5促进脂肪生成.miR-218-5p可以通过靶向Elovl5促进脂肪酸合成，从而加速NAFLD的发展，是NAFLD的关键致病机制之一,为NAFLD的治疗提供了新的分子靶点。
