Dexamethasone reverses TGF‐β‐mediated inhibition of primary rat preadipocyte differentiation

FEBS Letters

Kim, Jae Kwang¹  Choi, Inpyo¹  Shin, Sun Mi¹  Yoon, Suk Ran¹  Kim, Kun-yong¹  Yang, Young¹ 

[1] Laboratory of Immunology, Korea Research Institute of Bioscience and Biotechnology, Daejon 305-333, South Korea

关键词: Dexamethasone;    Rat preadipocyte;    Transforming growth factor-β;    CCAAT/enhancer binding protein-α;    Peroxisome proliferator-activated receptor γ;    TGF-β;    transforming growth factor-β;    C/EBP;    CCAAT/enhancer binding protein;    PPARγ;    peroxisome proliferator-activated receptor γ;    aP2;    fatty acid binding protein;   

DOI  :  10.1016/S0014-5793(03)00371-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Dexamethasone and transforming growth factor-β (TGF-β) show contrary effects on differentiation of adipocytes. Dexamethasone stimulates adipocyte differentiation whereas TGF-β inhibits it. In the present study, we investigated whether dexamethasone could reverse the TGF-β-mediated inhibition of preadipocyte differentiation. Primary rat preadipocytes, obtained from Sprague–Dawley rats, were pretreated with dexamethasone in the presence or absence of TGF-β, prior to the induction of differentiation. Co-treatment of dexamethasone and TGF-β before inducing differentiation reversed the TGF-β-mediated inhibition of preadipocyte differentiation. In order to elucidate the mechanism by which dexamethasone reversed the effect of TGF-β on the inhibition of preadipocyte differentiation, the expression of CCAAT/enhancer binding protein-α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ) was examined. Dexamethasone increased C/EBPα and PPARγ expression in the absence of TGF-β and also recovered the TGF-β-mediated suppression of C/EBPα expression in preadipocytes. Its effect was sustained in differentiated adipocytes as well. However, those effects were not observed in 3T3-L1 preadipocytes or differentiated adipocytes. These results indicate that dexamethasone reverses the TGF-β-mediated suppression of adipocyte differentiation by regulating the expression of C/EBPα and PPARγ, which is dependent on the cellular context.

【 授权许可】

Unknown