%A Yong Guo, Qi Lv, Xian-qiong Zou, Zhi-xiong Yan, Yu-xian Yan
%T Mechanical Strain Regulates Osteoblast Proliferation Through Ca2+-CaMK-CREB Signal Pathway
%0 Journal Article
%D 2016
%J Chinese Medical Sciences Journal
%R 10.1016/S1001-9294(16)30033-5
%P 100-106
%V 31
%N 2
%U {http://cmsj.cams.cn/CN/abstract/article_314.shtml}
%8 2016-06-20
%X Objective To investigate the effects of mechanical strain on Ca2+-calmodulin dependent kinase (CaMK)-cAMP response element binding protein (CREB) signal pathway and proliferation of osteoblasts.Methods Using a four-point bending device, MC3T3-E1 cells were exposed to mechanical tensile strains of 2500 µs and 5000 µs at 0.5 Hz respectively. The intracellular free Ca2+ ([Ca2+]i) concentration and calmodulin activity were assayed by fluorospectrophotometry, CaMK II β, CREB, and phosphorylated (activated) CREB (p-CREB) were assessed by Western blot, and cells proliferation was assayed with MTT. Pretreatment with verapamil was carried out to block Ca2+ channel, and inhibitor U73122 was used to inhibit phospholipase C (PLC).Results Mechanical strains of 2500 µs and 5000 µs for 1 to 10 minutes both increased [Ca2+]i level of the cells. The 2500 µs strain, a periodicity of 1 h/d for 3 days, activated calmodulin, elevated protein levels of CaMK II β and p-CREB, and promoted cells proliferation, which were attenuated by pretreatment of verapamil or U73122. The effects of 5000 µs strain on calmodulin, CaMK II β, p-CREB and proliferation were contrary to 2500 µs strain.Conclusion The mechanical strain regulates osteoblasts proliferation through Ca2+-CaMK-CREB signal pathway via Ca2+ channel and PLC/IP3 transduction cascades.