压力对髁突软骨细胞超微结构及可聚蛋白多糖分泌的影响

目的 探讨髁突软骨细胞超微结构及软骨可聚蛋白多糖(aggrecan)分泌随压力的变化过程。方法 体外培养髁突软骨细胞，采用可控液压细胞加载装置90kPa压强下分别加载60min、360min，透射电镜观察细胞的超微结构，原位杂交方法观察髁突软骨细胞(MCC)中软骨可聚蛋白多糖mRNA的表达。结果 对照组细胞在透射电镜下生长良好，未见到细胞凋亡现象；90kPa加压60min后细胞生长状态亦良好，多见到明显伸长盘绕的微绒毛；90kPa加压360min后细胞部分出现明显的细胞凋亡指征；软骨可聚蛋白多糖mRNA在受压60min后表达明显增强，加压时间延长到360min后表达弱于60min组但仍高于对照。结论适宜的压力可使MCC结构及功能都发生一定的变化，aggrecan代谢水平升高。

Effects of Mechanical Pressure on the Ultrastructure and the Aggrecan Synthesis in Mandibular Condylar Chondrocytes

Objective To investigate the change of the ultrastructure and the variation of synthesis in aggrecan,the main proteoglycan component of the cartilage matrix of mandibular condylar chondrocytes(MCC), under the mechanical pressure. Methods In vitro cultured MCC from two-week-old New Zealand rabbits were incubated under continuous pressure of 90 kPa for 60min,360min by hydraulic pressure controlled cellular strain unit.The ultrastructure of MCC was observed under transmission electron microscope(TEM).In situ hybridization method was used to test aggrecan mRNA expression in MCC. Results The appearance of MCC on TEM showed that the cells of the control developed in the normal way.After been pressed under 90kPa for 60min,the cells showed elongated and voluminous cellular processes with increasing aggrecan mRNA.When the pressure lasted to 360 min,some of the cells showed distinct sign of apotosis and the aggrecan mRNA decreased but still higher than that of the control. Conclusion Continuous pressure could cause changes on the ultrastructure and function of MCC.Pressure may be used to up-regulate the synthesis of aggrecan.