The Effects Of MiR-20a Targeting LDLR On Selective Absorption Of LDL-C In Porcine Hepatocytes

Low density lipoprotein receptor(LDLR)mainly participates in lipoprotein metabolism through the LDL receptor pathway,and is a key gene in the lipid metabolism regulation process in animals.microRNAs are a class of non-coding RNAs of about 22nt in size,which regulate the expression of target genes at the post-transcriptional level by inhibiting the translation of target genes or degrading target genes.Studies on lipid metabolism in pigs mainly focus on feed nutrition,but there are few studies on molecular genetic mechanism.The previous dual luciferase assay results of our research group have confirmed the binding site and a direct targeting relationship between porcine LDLR and miR-20a.However,the targeting relationship between LDLR and miR-20a in porcine hepatocytes and the effect of miR-20a on LDLR-mediated selective absorption of low density lipoprotein Chesterol(LDL-C)in porcine hepatocytes remain unclear.By studying the role of miR-20a in regulating the cholesterol metabolism pathway of LDL-C selective absorption in porcine hepatocytes by targeting LDLR,this experiment aimed to provide new basis for the exploration of genetic breeding improvement of pigs from the perspective of genetic regulation of lipid metabolism in pigs,and also provide new ideas for the study of prevention and treatment of atherosclerosis and other vascular diseases in human.The porcine primary hepatocytes were used as experimental materials.After transfection to porcine hepatocytes with miR-20a mimics or miR-20a inhibitor,the mRNA expression levels of miR-20a and LDLR genes were detected by RT-qPCR,and the uptake of DiI-LDL in porcine hepatocytes was analyzed by flow cytometry.The LDLR gene was silenced by siRNA technology and then co-transfected with miR-20a mimics or inhibitor into porcine primary hepatocytes to further evaluate the effect of miR-20a on LDLR expression and the cholesterol selective absorption mediated by LDLR in porcine hepatocytes.The main results are as follows:1.miR-20a mimics could significantly reduce LDLR mRNA expression in porcine hepatocytes,and miR-20a inhibitor could significantly increase LDLR mRNA expression in porcine hepatocytes.2.miR-20a mimics could significantly weaken the selective absorption of Dil-LDL in porcine hepatocytes,and miR-20a inhibitor could significantly enhance the selective absorption of Dil-LDL in porcine hepatocytes.3.miR-20a regulates the selective uptake of Dil-LDL in porcine hepatocytes by targeting LDLR.