BMP2 increases adipogenic differentiation in the presence of dexamethasone, which is inhibited by the treatment of TNF-α in human adipose tissue-derived stromal cells

Abstract

Background/aims: The aim of this study was to analyze the effect of BMP2 on osteogenic differentiation of human adipose tissue-derived stromal cells (hADSCs).

Methods: Cultured cells were differentiated into osteogenic lineage in the presence of BMP2. Gene expressions were determined by real time PCR.

Results: BMP2 increased (2/8) or inhibited (6/8) osteogenic differentiation according to hADSCs batches. Regardless of the BMP2 action on osteogenic differentiation, BMP2 induced lipid droplet formation under an osteogenic differentiation condition in all batches of hADSCs, not hBMSCs, to be tested, which was confirmed by analysis of adipogenesis related genes expression. hADSCs expressed various BMP receptors. BMP2 increased expression of BMP2-responsive genes such as DLX3 and ID2, and induced SMAD1 phosphorylation in hADSCs and hBMSCs. BMP2 increased osteogenic differentiation of hADSCs in osteogenic medium in which dexamethasone was omitted. The addition of BMP2 in the control culture media containing dexamethasone alone lead to formation of lipid droplets and increased C/EBP-α expression in hADSCs. In the presence of TNF-α, BMP2 stimulated osteogenic differentiation of hADSCs even in hADSCs batches in which treatment of BMP2 alone inhibited osteogenic differentiation.

Conclusion: These data indicate that the control of osteogenesis and adipogenesis in hADSCs is closely related, and that hADSCs have preferential commitment to adipogenic lineages.