机械牵张力对人牙周膜细胞成骨样细胞功能的影响

Effects of mechanical stretching force on osteoblast-like function of human periodontal ligament cells in vitro

目的 观察机械力作用下人牙周膜细胞成骨样细胞特性的改变 ,以深入探讨正畸牙齿移动的机理。方法 利用自行研制的细胞加力装置对体外培养的人牙周膜细胞施加间歇性机械牵张力 ,检测其成骨样细胞表型蛋白碱性磷酸酶 (alkalinephosphotase ,ALP)、骨桥蛋白 (osteopontin ,OPN)和骨钙素 (osteocalcin ,OCN)表达的改变。结果 人牙周膜细胞在受到机械牵张力刺激后表现为ALP分泌活性的增加 ,而且 2 4h的时段内波动 ,2、4h和 2 4h出现 2个显著增高期 (P <0 0 1) ;OCN受机械牵张力影响出现较缓慢和晚期的表达增强 ,加力 4h后缓慢增高 ,在 12h最为明显 (P <0 0 5 ) ;非分泌型ALP、OPN随观察时间延长蛋白表达增强 ,而OCN也有可能表达。结论 人牙周膜细胞在间歇性牵张力的作用下 ,其成骨样细胞蛋白表达水平 ,如ALP、OCN和OPN都增强 ,具有时序性。提示人牙周膜细胞在机械力诱导下向成骨样细胞分化成熟 ,从而可能在机械力介导的骨改建中起作用。

Objective To investigate the osteoblast like functional characteristics exhibited by human periodontal ligament cells (hPDLCs) under mechanical force. Methods Human PDLCs cultured in vitro were stretched by mechanical force. Radioimmunoassay (RIA) was used to measure the expression of secreting alkaline phosphotase(ALP)and osteocalcin (OCN). The non secreting ALP, OCN and osteopontin (OPN) in cells were determined by immunohistochemistry. Results It exhibited increasing of ALP secreted into conditional media, and in the 24 hour period there were two peaks which appeared at the 2nd and 4th hour and the 24th hour ( P <0 01). While in the late of the 24 hours, expression of OCN in conditional media increased ( P <0 05).Conclusion Mechanical force induces hPDLCs to differentiate into functional osteoblast like cells and plays a role in bone remodeling.