miR-202 promotes the differentiation of 3T3-L1 preadipocyte via inhibiting PGC1β expression / 基础医学与临床

Objective To explore the effect and molecular mechanism of miR-202 on the differentiation of 3T3-L1 preadipocyte .Methods 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 PGC1βby Western blot method .Results After packa-ging lentivirus with AMO-miR-202 and random sequence control miRNA through cell line 293T, 80%-90%cells with fluorescence were found under fluorescence microscope; After these two lentivirus respectively infected with 3T3-L1 preadipocytes, About 70%-80%cells with fluorescence were found 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 PGC 1βin the AMO-miRNA-202 group was significantly increased(P<0.05), but the expression of aP 2 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 .Conclusions miR-202 can promote the differentiation of 3T3-L1 preadipocyte by inhibiting the protein expression of PGC 1βand im-proving the protein expression of PPARγ2 and aP2.

Obestatin inhibits proliferation and differentiation of 3T3-L1 preadipocytes / 第二军医大学学报

Objective: To investigate the inhibitory effects of obestatin on proliferation and differentiation of 3T3-L1 preadipocytes. Methods: Obestatin (10-8 mmol/L, 10-9 mmul/L, 10-10 mmol/L, 10-11 mmol/L, and 10-12 mmol/L) and ghrelin (10-10 mmol/L) were used to treat 3T3-L1 preadipocytes. Cell proliferation was assessed by MTT assay and the results were compared with that of blank control group. The differentiation of 3T3-L1 preadipocytes (from day 1 to day 10) was interfered with obestatin or ghrelin (both at 10-10 mmol/L). Intracellular fat accumulation in differentiated adipocytes was determined by oil red O staining and the expression of PPAR-γ2 mRNA was detected by RT-PCR; the results were compared with that of control group (induced with routine inducer). Results: Compared with the blank control group, obestatin-treated groups (various concentrations of obestatin) had significantly less cells(P<0.05). Oil red O staining revealed that, compared with control group, the formation of lipid droplets was significantly decreased after 10 days' of treatment with 10-10 mmol/L obestatin (P<0.05). The expression of PPARγ2 gene increased with the progress of 3T3-L1 preadipocytes differentiation. PPAR-γ2 mRNA level in mature adipocytes of obestatin group was significantly lower than that in the cells of control group. The effect of ghrelin was contrary to that of obestatin. Conclusion: Obestatin can inhibit the proliferation and differentiation of 3T3-L1 preadipocyes.

Role of miR-24 in the regulation of 3T3-L1 adipicyte differentiation and the expression of fatty acid binding protein / 中国药理学通报

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.

The Effects of Epigallocatechin on Adipogenesis of 3T3-L1 Preadipocytes

Preadipocyte cell lines are useful models for investigating adipogenesis process. 3T3-L1 preadipocyte, which can be induced to differentiate into adipocyte in cell culture, is one of the most studied preadipocyte cell lines. When exposed to the appropriate differentiation inducer, including insulin, dexamethasone and 3-isobutyl- 1-methylxanthine, 3T3-L1 preadipocytes differentiate into adipocytes. This study was undertaken to evaluate the effect of epigallocatechin on differentiation of 3T3-L1 preadipocyte, and to test whether epigallocatechin can be useful to reduce fat deposition. Cell proliferation was determined by MTT(3,4,5-Dimethylthiazol-2,5-Diphenyl- Tetrazoliumbromide) spectro-photometry, fat content followed by cell differentiation was determined by Oil Red O staining, and the degree of differentiation into adipocytes were determined by measuring mRNA content and activity of glyceraldehydes 3-phosphate dehydrogenase (G3PDH). Epigallocatechin inhibited proliferation of preadipocytes, not into adipocytes. Fat storage during 3T3-L1 preadipocyte conversion into adipocyte was inhibited by epigallocathechin. Epigallocatechin decreased G3PDH, leptin mRNA and peroxisome proliferator-activated receptor(PPAR)gamma mRNA which were increased by differentiation of preadipocyte into adipocyte. These results suggest that epigallocatechin has a potential to serve as a fat-reducing drug.

Studies on the antiobesity action and mechanisms of daidzein derivative:LRXH609 / 中国临床药理学与治疗学

AIM: To approach the antiobesity action and mechanisms of the daidzein derivative: LRXH609(LRX).METHODS: The body weight,Lee′s index,total weight of celiac fat tissue,food intake,serum glucose and lipids in obese rats induced by a high-fat diet were measured and the antiobesity action was tested after LRX was administered for 30 days.3T3-L1 pre-adipocytes were induced by in vitro culture,the effects of LRX on cell proliferation,lipogenesis,lipolysis were observed.RESULTS: The body weight,Lee′s index,fat tissue weight in obese rats were significantly decreased by LRX,and the concentrations of TC,FFA in serum were decreased,the proliferation of 3T3-L1 pre-adipocytes was inhibited,the activities of hormone sensitive lipase in 3T3-L1 pre-adipocytes were significantly elevated,the glycerine release from adipocytes was promoted and the concentrations of TG in adipocytes were decreased.CONCLUSION: LRX plays a role in antiobesity action and regulating blood lipid and the mechanism might be related to inhibiting proliferation and differentiation of pre-adipocytes,stimulating TG decomposition by activating hormone-sensitive lipase and decreasing the TG storage in adipocyte.