Abstract: Objective: To explore the effect and molecular mechanism of miR-202 on the differentiation of 3T3-L1 preadipocyte.Method:Through lentivirus infected with 3T3-L1 preadipocytes, we set up the AMO-miR-202 group and the random control group, then, these cells were induced to differentiate, nine days later, differentiation was assessed by oil red O staining and we examined the mRNA expression of PPARγ2 and aP2 by RT-PCR method.We examined the mRNA expression of PPARγ2、ap2 and PGC1β by Western-blot method. Results:After packaging lentivirus with AMO-miR-202 and random sequence control miRNA through 293T cell line, we can see about 80%-90% cells with fluorescence under fluorescence microscope; After these two lentivirus respectively infected with 3T3-L1 preadipocytes, we can see about 70%-80% cells with fluorescence under fluorescence microscope.Oil red O staining test showed that these cells with oil red O stained bright red fat droplets of AMO-miR-202 group and PPARγ2 and aP2 mRNA expression in the AMO-miR-202 group significantly lower than control groups (P＜0.05).Western-blot assay showed that the protein expression of PGC1β in the AMO-miRNA-202 group was significantly increased(P<0.05), but the protein expression of aP2 and PPARγ2 was significantly decreased (P＜0.01), however, the random control group and the adipocyte group had no significant effect on the above indexes. Conclusion:miR-202 can promote the differentiation of 3T3-L1 preadipocyte by inhibiting the protein expression of PGC1β and improving the protein expression of PPARγ2 and aP2.

Key words: KEY WORDS：miR-202, 3T3-L1 preadipocyte, adipocyte differentiation, PGC1β