周期性单轴压应力对大鼠髁突软骨细胞Stress70/GRP75的早期影响

Early effects of the cyclic uniaxial compressive stress on Stress70/GRP75 in the rat condylar chondrocytes

目的:探讨体外周期性单轴压应力对大鼠髁突软骨细胞糖调控蛋白Stress70/GRP75的早期动态变化影响。方法:利用四点弯曲细胞力学加载仪,对第3代大鼠髁突软骨细胞进行体外周期性单轴压应力加载,力值为4000μstrain,时间分别为0、15、30、60、120、240min;采用Western免疫印迹技术和图像分析技术,研究大鼠髁突软骨细胞糖调控蛋白Stress70/GRP75的动态变化,对结果进行单因素方差分析。结果:4000μstrain周期性单轴压应力作用下,大鼠髁突软骨细胞糖调控蛋白Stress70/GRP75的表达发生变化,0min条带灰度值为114.2±5.08;30min时降至最低,为86.1±5.09(P<0.001);60min后有所回升,至104.0±4.41(P<0.01),但仍表达下调;120min后表达开始增强,灰度值为134.5±3.74(P<0.001)。结论:4000μstrain压应力刺激,对大鼠髁突软骨细胞糖调控蛋白Stress70/GRP75存在时间效应性,初期表达下调;随着应力加载时间延长,其表达反馈增强。

PURPOSE： The purpose of this study was to investigate the early effects of the cyclic uniaxial compressive stress on Stress70/GRP75 in the rat condylar chondrocyte. METHODS： The third-passage chondrocytes were harvested from the mandibular condyles of 2-day-old rats for this study, and a cellular compressive stress device （self-made fourpoint bending system,Patent No. 01129166.4 ＆ 01256849.x） was used to apply stress on cells at 4000μstrain （ 0.5Hz frequency） for 0, 15, 30, 60, 120, 240 minutes respectively. The early effects of the cyclic uniaxial compressive stress on Stress70/GRP75 in the rat mandibular condylar chondrocytes were examined by Western blot and image analysis.Oneway ANOVA was used for statistical analysis. RESULTS＂ The results showed that the expression of Stress70/GRP75 changed significantly With 40001xstrain compressive stress loading.The gray scale value of protein band at 0 minute was 114.2±5.08, significantly decreased to 86.1±5.09 （P〈0.001）after 30 minutes, and then gradually increased to 104.0±4.41 （P〈0.01） at 60 minutes. The expression of Stress70/GRP75 up-regulated to 134.5±3.74（P〈0.001 ）at 120 minutes, and continued to increase within 240 minutes. CONCLUSION： There is time-dependent response between the 4000μstrain compressive stress stimulate and Stress70 /GRP75.The expression of Stress70 /GRP75 inhibited initially under the compressive stress,and then increased by feedback with the increased loading time. Supported by 2003 Academic and Technical Leader Candidate Project for Young and Middle-Aged Persons of Yunnan Province （Grant No.2003RC）.