Abstract: Objective　To investigate the different effects of continuous and cyclic hydrolic pressure on marker gene expression of chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Methods: BMSCs were obtained by whole bone marrow adherent separation culture method and identified by osteogenic and adipogenic induction assays. BMSCs were treated by continuous hydrostatic pressure at 45, 90kPa and cyclic hydrostatic pressure at 0~45, 0~90kPa. Four groups were treated with pressure 1 h per day for 2 days. The expression of Sox9, Aggrecan and Col-Ⅱ was detected by Real-time PCR. Results: Real-time PCR showed that under pressure the expression Sox9 was enhanced. The expression of Aggrecan in the cells under 45, 90 and 0~90kPa was significant higher than that of control group. The expression of Col-Ⅱgene was significantly increased under 90 and 0~90 kPa .Conclusions: Hydrolic pressure could promote the chondrogenic differentiation of BMSCs. The effect of 90 kPa on the chondrogenic differentiation is remarkable.

Key words: Hydrolic pressure, Bone marrow mesenchymal stem cells (BMSCs), chondrogenic differentiation