Abstract: Objective To investigate the BMP-2 and TNF alpha(TNF-α) on osteoblast proliferation and differentiation of different function and comparative analysis through the BMP – 2 and TNF alpha were stimulated the generation of osteoblast culture. Methods Wistar rat (1 week old) skull were surgery chipped under sterile conditions and osteoblasts were extracted, primary cell cultures, and passaged, purification, amplification. Using different concentrations of BMP-2 and TNF- α induced rat osteoblasts, Methyl thiazolyl tetrazolium (MTT) assay was used to detect the proliferation of osteoblasts, PP-nitrophenyl phosphate (PNPP) was used to detect the alkaline phosphatase (ALP) activity of osteoblasts.Results In vitro cultured cells by ALP staining and calcification were both positive, confirmed the cultured cells have the typical characteristics of mature osteoblasts. Rat osteoblast proliferation activity and ALP activity increases with BMP - 2 concentration, but decreased with increasing TNF-α, there was significant difference with control group (P < 0.05). Conclusion Transfection of BMP-2 can improve the proliferation and differentiation of osteoblasts. TNF- α has inhibitory effect on the proliferation and differentiation of osteoblasts. BMP -2 and TNF alpha respectively promote and inhibit in vitro culture of osteoblasts through different mechanisms.

Key words: tumor necrosis factorα, BMP2, osteoblast, proliferation, differentiation