The Preliminary Study of Mechanical Strain on Proliferation and Differentiation of Saos-2 Osteoblastic Cells

Objective:To investigate the effects of mechanical strain on proliferation and differentiation of Saos-2 osteoblastic cells.Methods:Saos-2 osteoblastic cells were subjected to elongation by using Flexcell strain loading system simultaneously.MTT colorimetric method was used to assess cellular proliferation;Biochemical analysis was used to study the effects of mechanical strain on alkaline phosphatase(ALP)activity;semi quatative RT-PCR was used to examine mRNA level of osteocalcin and osteopotin.Alizarin Red-S method was used to study the mineralization of Saos-2 osteoblastic cells.Results:The proliferation and ALP activity of Saos-2osteoblastic cells were significantly increased after mechanical strain treatment.12% elongation rate showed the strongest stimulatory effects(P0.01).The expression of OC,OPN mRNA and the formation of mineralization nodules in Saos-2osteoblastic cells were promoted by 12% mechanical strain elongation rate.Conclusion:Our data indicated that mechanical strain stimulation increased the proliferation and differentiation markers such as ALP activity,mRNA expression level of OC and OPN,and the formation of mineralization nodules in Saos-2osteoblastic cells.Mechanical strain may play a very important role in proliferation and differentiation of osteoblasts.