The Role And Mechanism Of MicroRNA-183-5p And MiR-470-3p In The Development Of Nonalcoholic Fatty Liver Disease(NAFLD)

Background MicroRNA is a class of small non-coding RNA molecules closely related to the regulation of related biological processes such as Non-alcoholic fatty liver disease.miRNA-183-5p and miR-470-3p have not previously been reported to be associated with the hepatic metabolic diseases,and how they regulate the lipid metabolism of NAFLD is still unclear.Therefore,this study focused on the role of miR183-5p and miR-470-3p in the occurrence of NAFLD and its potential mechanism.Materials and methods 1.A variety of non-alcoholic fatty liver disease(NAFLD)models were established to detect the mRNA expression of miR-1 83-5p and miR-4703p to explain the relationship between miRNA and hepatic lipid metabolism.2.miR183-5p and miR-470-3p was over-expressed/knocked-down by miRNA mimics and inhibitor in AML12 cell lines to detect the expression of genes involved in hepatic lipid metabolism by qRT-PCR and determine the triglyceride(TG)level by oil red O staining(ORO).3.C57BL/6 mice were injected with tail vein adenovirus overexpressing miR183-5p to measure the insulin sensitivity and explore the expression of genes involved in hepatic lipid metabolism.The TG levels and other metabolic injury markers were detected by the corresponding kits.Hepatic pathological changes were observed by H&E staining and ORO.4.Double luciferase reporter gene and bioinformatics methods were used to verify that BTG anti-proliferation factor 1(BTG1)was the target gene of miR-183-5p.5.inhibition of miR-183-5p and Knockdown BTG1 at the same time in AML12 cell lines to detect the level of lipid metabolism genes and its downstream signaling molecul es and measure the TG content.Results 1.The mRNA level of miR-183-5p was increased and miR-470-3p was decreased in different non-alcoholic fatty liver disease models.2.Overexpression of miR-183-5p and inhibition of miR-470-3p in AML12 cell lines promotes lipid accumulation and increases the expression of lipid metabolism-related genes.While inhibition of miR-183-5p and overexpression of miR-470-3p improves lipid deposition and down-regulates lipid metabolism-related genes.3.Up-regulation of miR-183-5p expression in C57BL/6 mice accelerated insulin resistance,and significantly increased the mRNA level of stearyl Co A desaturase-1(Scd1).The result of H&E staining and ORO showed that miR-183-5p could increase hepatic lipid accumulation.4.miR-1835p could induce lipid synthesis and increase TG accumulation by activating Scdl expression through binding directly to BTG1.Conclusion 1.The mRNA level of miR-183-5p and miR-470-3p is significantly altered in mouse and celluar NAFLD models,suggesting that it may be a novel biomarker for NAFLD.2.Overexpression of miR-183-5p and inhibition of miR-4703p resulted in up-regulation of lipid metabolism related genes and increased lipid deposition in liver.In contrast,overexpression of miR-470-3p and inhibition of miR183-5p in vitro leads to the downregulation of lipid metabolism-related genes and improve lipid deposition,suggesting that miR-183-5p and miR-470-3p is directly involved in liver lipid metabolism.3.BTG1 is a direct target gene of miR-183-5p,and miR-183-5p negatively regulates the expression of BTG1 to further promote the expression change of Scdl,which promote lipid synthesis and cause the occurrence of NAFLD.