The Role And Mechanism Of MiR-129-5p In Adipocytes Proliferation,Differentiation And Browning

MicroRNAs have been regarded to play crucial role in the proliferation,differentiation and browning of adipocytes.MicroRNA-129-5p was regarded to play a potential regulator role in tumor,it could also inhibite cell proliferation in many cancer cells.A miRNA microarray analysis showed that miR-129-5p was high expression in insulin-resistant 3T3-L1 preadipocytes,showed a probable role of mi R-129-5p in obesity.This study aimed at investigating the role of mi R-129-5p in adipocytes proliferation,differentiation and browning.In this study,we transfected 3T3 cells and mouse primary adipocytes with miR-129-5p mimic and detected the effect of miR-129-5p over-expression with EdU,flow cytometric,CCK-8,Oil red staining,Bodipy staining,RT-qPCR and Western blot.Then the luciferase reporter vectors containing G3BP1 3’UTR were constructed to further clear the mechanism of the negative regulator role of miR-129-5p in 3T3 preadipoccytes proliferation.Main results followed:1.The mature sequence and seed sequence of mi R-129-5p was highly conserved in various species such as human,mouse and rat.miR-129-5p was widely expressed in mouse tissues and relatively high expressed in brain,sWAT and BAT.The expression level of mi R-129-5p decreased during proliferation process and increased during adipocytes differentiation.2.Overexpression of miR-129-5p impacted the expression level of cell cycle related genes.Enhanced miR-129-5p level decreased the proportion of cells in S-phase and increased G2 phase proportion.MiR-129-5p inhibited 3T3 preadipocytes proliferation in both cellular and mocecular level.3.The expression level of G3BP1 was significantly inhibited by miR-129-5p.MiR-129-5p directly targeted the 3’UTR of G3BP1.P38 protein level and the phosphorylation level of p38 were significantly increased by miR-129-5p.MiR-129-5p played its suppressor role during preadipocyte proliferation by targeting G3BP1 and activating p38 signaling pathway.4.Overexpression of miR-129-5p didn’t change the expression of adipogenesis related genes.MiR-129-5p didn’t impact the number and formation of adipocytes.MiR-129-5p did not impact adipocytes differentiation process.5.The expression of UCP1 and Cidea were significantly increased after induced browning by rosiglitazone.The expression level of UCP1 and PGC1-α were both inhibited by overexpression of miR-129-5p.MiR-129-5p inhibited adipocytes browning in molecular level.Above all,miR-129-5p inhibited 3T3 preadipocytes proliferation by targeting G3BP1 and through p38 siginaling pathway.Also,miR-129-5p inhibited adipocytes browing in molecular level but didn’t impact adipocytes differentiation process.These results provide a theoretical basis for the selection of fat deposition traits and the regulation of white adipocytes browning by miRNAs.