中文摘要：

MicroRNAs（miRNAs）是一类在脂肪组织发育中发挥重要作用的小非编码RNA．为探明miR-125a．5p在3T3-L1前体脂肪细胞中的作用，采用实时qPCR检测了miR-125a-5p在小鼠各组织及3T3-L1前体脂肪细胞分化过程中的表达；使用经化学修饰的miR-125a-Sp模拟物agomir及抑制剂antagomir转染3T3-L1前体脂肪细胞，采用实时qPCR和Western印迹检测成脂标志基因PparT和aP2的表达，油红0染色观察脂肪细胞脂质积累．结果显示，miR-125-5P在小鼠脂肪组织中高丰度表达，在3T3-L1前体脂肪细胞分化过程中表达下降．过表达miR-125a-5P，与对照组相比，成脂标志基因Ppary和aP2在mRNA和蛋白质水平均明显下降；油红O染色及定量结果显示脂质积累减少．抑制剂处理结果显示，PparT和aP2在mRNA和蛋白质水平均有不同程度上升，但油红O染色及定量结果差异不显著．以上结果表明，miR-125a-5p在脂肪细胞分化中发挥负调控作用．

英文摘要：

miRNAs are small non-coding RNAs that are important for adipose tissue development. To explore the function of miR-125a-Sp during the induced differentiation of 3T3-L1 preadipocytes, we analyzed the miR-125a-Sp expression levels by real-time qPCR. Following the transfection of miR-125a- 5p agomir or antagomir into 3T3-L1 cells, the expression of adipogenic marker genes PparT and aP2 were also detected by both real-time qPCR and Western blotting. The lipid droplet formation was assayed by oil red O staining. The results showed that miR-125a-Sp was expressed at high levels in adipose tissue, and was downregulated during the process of adipogenesis. The differentiation of 3T3-L1 was impaired with miR-125a-5p overexpression, associated with the decrease of PparT and aP2 expression at mRNA and protein levels. The overexpression of miR-125a-5p also led to a notable reduction in lipid droplets as detected by oil red O staining. However, the results of miR-125a-5p antagomir transfection were not able to induce significant cell phenotype changes. In conclusion, we discovered a negative regulatory role of miR-125a-5p in 3T3-L1 preadiDocvtes differentiation.