G蛋白及蛋白激酶C在髁突软骨细胞力学信号转导过程中的作用  

The role of G protein and protein kinase C mechanical signalling transduction in mandibular condylar chondrocytes

作　　者：张旻 王美青[1] 王景杰[1] 

机构地区：[1]西安第四军医大学口腔医学院解剖生理教研室,710032

出　　处：《实用口腔医学杂志》2005年第2期163-166,共4页Journal of Practical Stomatology

基　　金：国家自然科学基金资助项目(No. 30000035)

摘　　要：目的:探讨髁突软骨细胞 (mandibularcondylarchondrocytes,MCCs)在机械力的变化过程中G蛋白和PKC的表达和分布以及G蛋白在PKC信号通路中的作用。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 60、360min,WesternBlot方法检测G蛋白表达水平;免疫组化染色观察加压前后及用G蛋白拮抗剂阻断G蛋白信号后PKC的表达及分布变化。结果: 90kPa的压力负荷可促进MCC中Gαq/11蛋白的表达,其中以加压 60min表达量最高。PKC在对照组MCC中弱阳性表达,并在胞质中均匀分布; 90kPa加压 60min后PKC表达强阳性且出现PKC的转位到胞膜及部分胞核的现象;加压 360min后PKC在细胞中的分布又趋于均匀;G蛋白拮抗后再经 90kPa加压 60min,MCC中PKC未出现PKC的转位现象。结论:适宜的压力刺激可引起髁突软骨细胞中G蛋白表达的增强及PKC的激活,而且压力导致PKC通路的激活是由G蛋白所介导的。Objective: To investigate the expression and distribution of G protein and protein kinase C (PKC) under the mechanical pressure in rabbit mandibular condylar chondrocytes (MCCs) and to study the role of G protein in PKC signalling pathway. Methods:MCCs from two-week-old New Zealand rabbits were cultured. After treatment under continuous pressure of 90 kPa for 60 min or 360 min by hydraulic pressure controlled cellular strain unit, the expression of Gαq/11 protein was examined by Western Blot. The expression and distribution of PKC was observed by immunocytochemical staining. Results:Gaq/11 protein in MCCs treated by 90 kPa for 60 min and 360 min was increased by 163.7% and 65.8% respectively(P<0.01),PKC was increased by 63.3%(P<0.01) and 31.4%(P<0.05) respectively. After treatment by the pressure of 90 kPa for 60 min combined with G protein inhibitor PKC expression in MCCs was not different with that in the control cells(P>0.05). PKC in control cells distributed uniformly in the cytoplasm. After been pressed under 90 kPa for 60 min,PKC translocated to the membrane and, partly,into nuclei. When the pressure prolonged to 360 min, PKC distributed uniformly again in cytoplasm. By treatment of G protein inhibitor, the translocation of PKC under 90 kPa of 60 min was not observed. Conclusion:Feasible pressure may promote G protein expression and activate PKC. The activation of PKC signalling pathway is mediated by G protein.

关 键 词：髁突软骨细胞 压力 G蛋白 蛋白激酶C 

分 类 号：Q257[生物学—细胞生物学]