Purpose： To investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro. Methods： Primary osteoblasts, bone marrow-derived mesenchymal stem cells （BMSCs, cultured in osteoinductive medium） and RAW264.7 cells cultured in osteoclast inductive medium were all subjected to a 1000μstrain （μs） at 1 Hz cyclic mechanical stretch for 30 min （twice a day）. Results： After mechanical stimulation, the alkaline phosphatase （ALP） activity, osteocalcin protein level of the osteoblasts and BMSCs were all enhanced, and the mRNA levels of ALP and collagen type I increased. Additionally, extracellular-deposited calcium of both osteoblasts and BMSCs increased. At the same time, the activity of secreted tartrate-resistant acid phosphatase, the number of tartrate-resistant acid phosphatase-positive multinucleated cells, matrix metalloproteinase-9 protein levels of RAW264.7 cells and the extracellular calcium solvency all decreased. Conclusion： The results demonstrated that 1000 μs cyclic mechanical loading enhanced osteoblasts activity, promoted osteoblastic differentiation of BMSCs and restrained osteoclastogenesis of RAW264.7 cells in vitro.
Yong GuoYang WangYinqin LiuHaitao WangChun GuoXizheng ZhangChaoyong Bei
