周期性张应力促进兔髁状突软骨细胞的增殖

Cyclic stress promotes the proliferation of rabbit condyle chondrocytes

背景:髁状突是下颌最重要的生长区之一,终生具有生长改建能力。在体内条件下,细胞力学的功能研究因其所处生理环境的复杂性、刺激因素传导的不定向性、实验条件的不易控制性而很难得到满意结果,应力刺激对髁状突软骨细胞的直接影响需要进一步行体外研究。目的:观察周期性张应力对体外培养兔髁状突软骨细胞生长增殖的影响。方法:体外分离培养及鉴定兔髁状突软骨细胞,在细胞培养至第3代时使用细胞加力装置对细胞施加强度为10%,频率为6循环/min的周期性张应力,作用时间分别为1,6,12和24 h,并设置未加力组作为对照。应用流式细胞仪检测细胞生长周期,应用MTT法分析细胞的增殖活性。结果与结论:在周期性张应力下,髁状突软骨细胞流式细胞仪检测结果显示在加力6 h和12 h,加力组细胞生长周期开始有显著性变化,在24 h达到实验最大值,差异有显著性意义(P<0.01)。MTT检测结果示细胞生长活跃,在6,12 h与对照组有明显变化,在24 h达到实验最大值,差异有显著性意义(P<0.01)。提示周期性张应力可明显促进髁状突细胞增殖,在24 h内具有持续促进作用。

BACKGROUND：The condyle is one of important areas of lower mandible growth, and has growth remodeling capacity lifetime. The in vivo functional research fails to obtain satisfactory outcome due to the complexity of physiological environment, nondirectiveness of stimulating factor transduction, and difficulty to control experimental conditions. Further studies wil explore the effect of stress on condyle chondrocytes in vitro. OBJECTIVE：To observe the effect of cyclic stress on the proliferation of rabbit condyle chondrocytes cultured in vitro. METHODS：Rabbit condyle chondrocytes were separated and cultured in vitro. Passage 3 chondrocytes were subject to cyclic tensile stress （10%surface elongation, 6 cycles/min） for 1, 6, 12, 24 hours. While those cells without stress served as the control group. The cellcycle changes were detected with flow cytometry analysis, and the cellproliferation were analyzed by MTT assay. RESULTS AND CONCLUSION：The flow cytometry analysis showed that S-phase promoting factor exhibited significant differences at 6 and 12 hours compared with control group, and got the maximum value at 24 hours （P〈0.01）. MTT assay results showed that the cells proliferation at 6 and 12 hours exhibited significant differences compared with the control group, and got the maximum value at 24 hours （P〈0.01）. The cyclic stress can obviously promote the proliferation of condyle chondrocytes, and the stimulative effect can be sustained 24 hours.