Summary
The effects of ghrelin on the proliferation and differentiation of 3T3-L1 preadipocytes and the possible mechanisms were investigated in this study. 3T3-L1 preadipocytes were cultured in vitro and treated with different concentrations of ghrelin. Proliferation of 3T3-L1 preadipocytes was evaluated by MTT method and mRNA levels of c-myc and thymidine kinase were detected by RT-PCR. Morphological changes of 3T3-L1 preadipocytes were observed and cell differentiation was measured by oil red O staining. The mRNA levels of peroxisome proliferator-activated receptor γ (PPARγ) and CAAT/enhancer binding protein (C/EBPα) in the cells at different differentiation stages were detected by RT-PCR. The results showed that ghrelin at concentrations of 10−7 to 10−15 mol/L could significantly promote preadipocyte proliferation (P<0.05), with the most pronounced effect observed at 10−11 mol/L (P<0.01). Treatment of 3T3-L1 preadipocytes with ghrelin significantly increased the mRNA levels of c-myc and thymidine kinase (P<0.01). Morphological findings demonstrated that the great amount of lipid droplets appeared in the 3T3-L1 preadipocytes treated with ghrelin. Ghrelin could morphologically induce the differentiation of 3T3-L1 preadipocytes into mature adipocytes. Ghrelin significantly increased the mRNA levels of PPARγ and C/EBPα during the differentiation, when compared with control group (P<0.05). The mRNA levels of PPARγ and C/EBPα were obviously up-regulated with the differentiation of preadipocytes after the treatment of ghrelin. There were significant difference in the mRNA levels of PPARγ and C/EBPα on day 2 and day 8 of the differentiation of 3T3-L1 preadipocytes (P<0.01). In conclusion, ghrelin could promote the proliferation and differentiation of 3T3-L1 preadipocytes by increasing the mRNA levels of PPARγ and C/EBPα and therefore enhance the sensitivity of adipocytes against insulin.
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This project was supported by a grant from the National Natural Sciences Foundation of China (No. 30600213).
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Liu, J., Lin, H., Cheng, P. et al. Effects of ghrelin on the proliferation and differentiation of 3T3-L1 preadipocytes. J. Huazhong Univ. Sci. Technol. [Med. Sci.] 29, 227–230 (2009). https://doi.org/10.1007/s11596-009-0218-x
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DOI: https://doi.org/10.1007/s11596-009-0218-x