间歇性机械牵张力对人牙周膜成纤维细胞增殖动力学的影响

Effects of Mechanical Stress on the Proliferation Kinetics of the Human Periodontal Fibroblast Cells in vitro

目的观察间歇性机械牵张力作用下,人牙周膜成纤维细胞(hPDLFs)增殖动力学的变化,探究机械力介导的牙周组织改建的可能机制.方法体外培养hPDLFs,取第4～7代细胞,通过四点弯曲细胞力学加载仪对细胞加载不同力值大小的间歇性机械牵张力(1 000,2 000,3 000 μstrain),分别在不同时间点收集细胞,流式细胞仪测定细胞DNA含量,计算增殖指数(PI).结果机械牵张力影响hPDLFs增殖活性.1 000 μstrain和2 000 μstrain机械牵张力组与对照组相比,均能促进细胞增殖,hPDLFs DNA含量增多(P＜0.05),增殖指数升高(P＜0.05);3 000 μstrain机械牵张力组与对照组比较,增殖指数无差异(P＞0.05),但抑制细胞DNA合成(P＜0.05).结论一定力值范围的机械牵张力能促进hPDLFs的增殖活性,过大力值的机械牵张力反而抑制细胞增殖.

Objective The purpose of this study was to explore the possible principles for remodeling of periodontal tissues under mechanical stretching by investigating the effects of intermittent mechanical stretching delivered by a new invented type of cell stress machine on the proliferation kinetics of the human periodontal fibroblast cells （hPDLFs） in vitro.Methods hPDLFs were cultured in vitro. The 4-7th generation of hPDLFs were undergone mechanical stretching. All cells were grouped as strained and unstrained （controls）. Strained groups cells were gathered after 2,4 and 6 hours with the stress 1 000,2 000 and 3 000μstrain.Flow cytometry （FCM） was used to examine the ratio of DNA（S% ） and the index of proliferation（PI）. Resuils Mechanical force would lead to the change of hPDLFs proliferation. Within the experiment, both 1 000μtrain and 2 000 p.straln could increase the proliferation index （PI） （ P 〈 0.05）.While trader 3 000μtrain, DNA synthesis was significantly decreased（ P 〈0. 05）. Condusion Some range of mechanical stretching accelerates hPDLFs proliferation. This research discusses the remodeling process of periodontal tissues undergoing the mechanical stretching on cytological view, and it makes a basement for further revealing the mechanical strain induced periodontal biological principles. Also it provides a useful direction for clinical orthodontic therapy.