目的探讨microRNAs对脂肪细胞分化过程的调节作用分子机制及其对脂肪特异性基因——脂肪型脂肪酸结合蛋白(fatty acid binding protein,FABP4)表达的影响。方法用microRNAs微阵列分析法筛选和鉴定3T3-L1脂肪细胞分化相关性microRNAs,构建脂肪细胞分化相关性micro-RNAs的高表达质粒,通过脂质体介导转染3T3-L1前体脂肪细胞,观察脂肪相关性microRNAs对脂肪细胞分化过程的影响,Westernblot和RT-PCR分别检测FABP4蛋白及其mR-NA在脂肪细胞分化过程中的表达变化。结果3T3-L1脂肪细胞分化过程中microRNA表达谱发生明显改变,其中35个microRNAs下调,miR-24最明显;17个microRNAs上调,miR-21最明显;用不同脂肪相关性microRNAs转染3T3-L1前体脂肪细胞并高表达后,发现miR-24明显抑制脂肪细胞的分化与成熟,而miR-21则无影响;miR-24明显抑制FABP4蛋白表达,但对其mRNA无影响,miR-21对FABP4的蛋白和mRNA表达都没有影响。结论3T3-L1脂肪细胞分化过程中存在脂肪细胞分化相关性microRNAs;miR-24脂肪细胞分化过程及其脂肪特异蛋白FABP4表达有重要的调节作用。
Aim To explore the effect of microRNAs on the differentiation of 3T3-L1 adipocytes and the expression of adipo-related gene-fatty acid binding protein during the adipocyte differentiation.Methods adipo-related microRNAs during 3T3-L1 adipocyte differentiation were screened and identified by micorRNA microarray.Constructed high-expression plasmids of the adipo-related microRNAs,were transfected into the 3T3-L1 preadipocytes by lipofectamine.While the effect of adipo-related microRNAs on the course of 3T3-L1 adipocyte differentiation was observed,the protein and mRNA expression level of fatty acid binding protein(FABP4)were analyzed by Western blot and RT-PCR during 3T3-L1 adipocyte differentiation.Results The expression profiles of microRNAs have significant changed during 3T3-L1 adipocyte differentiation,in which 35 microRNAs among them down-relation,the most lowly expression is miR-24;17 microRNAs among them up-relation,the most highly expression is miR-21.MiR-24 significantly inhibited adipocyte differentiation and maturity,while miR-21 have no significant effect.MiR-24 significantly inhibited the expression of FABP4,but had no effect on the level of its mRNA;miR-21 had no effect on the expression of protein and mRNA of FABP4.Conclusion There exist adipogenic-related microRNAs during 3T3-L1 adipocyte differentiation; miR-24 play an important role in the regulation of 3T3-L1 preadipocyte differentiation into adipocyte and the(FABP4)protein expression.