Abstract:

[Abstract]   Objective   To investigate the effect of1, 25- dihydroxy-vitamin D3(1, 25(OH)₂D₃ ) on adipocyte differentiation and the underlying mechanism.   Methods   The mesenchymal stem cell line C3H10T1/2was randomly divided into6 groups including control group, differentiation group and4different doses of 1, 25(OH)₂D₃ groups. The control group wastreated with vehicle. The differentiation group was supplemented with adipocyte differentiation reagent. And the 1, 25(OH)₂D₃ groups were treated with adipocyte differentiation reagents and10^-9, 10^-8, 10^-7and10^-6 mol/L of1, 25(OH)₂D₃  After culturing for5days, the cells were stained with oil red O, and the expression levels of adipocyte-specific transcription factors and Wnt/ β-catenin signaling pathway related genes were examined by RT-PCR or Western blot methods. Results   1, 25(OH)₂D₃ significantly reduced the number of differentiated adipocytes and blocked the mRNA levels of adipocyte specific transcription factor PPARγ(peroxisome proliferator-activated receptor gamma), C/EBP α(CCAAT enhancer binding proteinα) and adipocyte characterization factor aP2(fatty acid binding protein 4). These were paralleled by the decreased mRNA expression of Wnt/β-catenin signaling pathway inhibitor sFRP1(Secreted frizzled-related protein 1) and the increased level of β-catenin protein.  Conclusion   1, 25(OH)₂D₃ inhibits adipocyte differentiation, which may be related to the activation of Wnt/β-catenin signaling.

Key words: adipocytes, cell differentiation, Calcitriol, PPARgamma, CCAAT- enhancer- binding protein- alpha, beta catenin, adipocyte characterization factor aP2