S100A16基因促进3T3-L1前脂肪细胞分化

目的 研究S100A16基因在3T3-L1前脂肪细胞分化过程中的作用及机制.方法 构建过表达S100A16的慢病毒载体(PLJMI-S100A16-GFP),转染3T3-L1细胞.以Western印迹法检测S100A16正常3T3-L1细胞分化过程中S100A16的表达；采用油红O观察脂滴堆积情况；采用Western印迹和实时定量PCR方法检测前体脂肪细胞分化过程中相关基因的表达变化.免疫共沉淀方法检测S100A16是否与p53相互作用.结果 成功构建S100A16过表达3T3-L1细胞株；随着3T3-L1前脂肪细胞的分化,S100A16蛋白表达水平逐渐升高；高表达S100A16能够促进3T3-L1前脂肪细胞分化,促进甘油三酯在脂肪细胞内聚集(P＜0.01),同时上调脂肪细胞分化标志基因PPARy、CCAAT增强子结合蛋白α(C/EBP-α)、脂蛋白脂酶、脂肪细胞脂肪酸结合蛋白(aP2)及脂肪酸合成酶的表达(P＜0.05或P＜0.01)；免疫共沉淀结果提示,S100A16蛋白与p53相互作用.结论 S100A16通过抑制p53活性进而促进3T3-L1前脂肪细胞的分化.

S100A16 promotes differentiation of 3T3-L1 preadipocyte

Objective To investigate the effect and mechanism of S100A16 in the course of 3T3-L1 preadipocytes differentiation.Methods A recombinant virus vector overexpressing S100A16 ( PLJM1-S100A16-GFP) was constructed and transfected into 3T3-L1 preadipocytes.The expression of S100A16 in the course of 3T3-L1 preadipocytes differentiated into adipocytes was detected by Western blot.The lipid droplets were observed by oil-red O staining and triglycercide (TG) content was measured by the TG measure kit.Levels of adipogenesis-associated genes such as PPARγ,CCAAT/enhancer binding protein ( C/EBP-α),lipoprotein lipase ( LPL),fatty acid synthase ( FAS),adipocyte fatty acid binding protein( aP2 ) were measured by realtime PCR and Western blot.The interaction between S100A16 and p53 was detected by immunoprecipitation.Results 3T3-L1 cell line overexpressing S100A16was successfully contructed.It was found that the expression of S100A16 was increased during 3T3-L1 adipocytes differentiation.Overexpression of S100A16 stimulated 3T3-L1 preadipocytes differentiation and increased the accumulation of triglycerides in adipocytes (P＜ 0.01 ),along with the up-regulation of adipocyte differentiationassociated gene expressions including PPARγ,C/EBP-α,LPL,aP2,and FAS ( P ＜ 0.05 or P ＜ 0.01 ).Immunoprecipitation analysis revealed that S100A16 interacted with tumor suppressor protein p53,also a known inhibitor of adipogenesis.Conclusion S100A16 stimulates 3T3-LI preadipocytes differentiation via inhibiting p53activity.