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Dexamethasone reverses TGF‐β‐mediated inhibition of primary rat preadipocyte differentiation
Author(s) -
Shin Sun Mi,
Kim Kun-yong,
Kim Jae Kwang,
Yoon Suk Ran,
Choi Inpyo,
Yang Young
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)00371-5
Subject(s) - dexamethasone , primary (astronomy) , microbiology and biotechnology , endocrinology , transforming growth factor , medicine , chemistry , biology , physics , astronomy
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.