碘乙酸钠诱导原代大鼠软骨细胞凋亡

Monosodium iodoacetate induces apoptosis of primary rat chondrocytes

背景:近年碘乙酸钠多用于诱导骨关节炎的发生,病理结果观察到软骨区域凋亡的发生,但有关碘乙酸钠诱导软骨细胞凋亡机制的研究较少。目的:探讨不同剂量碘乙酸钠诱导原代大鼠软骨细胞凋亡的发生机制。方法:使用酶消化法建立大鼠关节软骨细胞培养体系;荧光显微镜和流式细胞仪检测软骨细胞凋亡;激光共聚焦显微镜和荧光分光光度计评估线粒体膜电位的改变;荧光分光光度法测定活性氧水平改变;免疫印迹法检测凋亡调控蛋白细胞色素C和caspase-3的表达。结果与结论:碘乙酸钠剂量依赖性地诱导软骨细胞凋亡,使活性氧水平显著升高(P<0.05),线粒体膜电位水平明显降低(P<0.05),凋亡调控蛋白的表达明显增加。提示碘乙酸钠诱导的原代大鼠软骨细胞凋亡主要与活性氧的产生及线粒体介导的caspase-3活化有关。

BACKGROUND： Recently, monosodium iodoacetate is usually used to cause cartilage degradation resembling the pathological changes of human osteoarthritis. However, rate studies report the mechanisms underlying monosodium iodoacetate-induced chondrocyte apoptosis.OBJECTIVE： To assess the apoptosis of primary rat chondrocytes induced by different concentrations of monosodium iodoacetate and to clarify the underlying mechanism.METHODS： The primary rat chondrocytes were treated with monosodium iodoacetate for 24 hours, and the induction of apoptosis was analyzed by flow cytometry and Hoechst 33342/PI staining. The levels of mitochondrial membrane potential were evaluated using fluorescence spectrophotometer and laser scanning confocal microscope. The production of reactive oxygen species was determined by fluorescence spectrophotometer. Apoptosis-related protein cytochrome C and caspase-3 expressions were examined by western blotting.RESULTS AND CONCLUSION： Monosodium sodoacetate induced cellular apoptosis in a dose-dependent manner. Significantly increased level of reactive oxygen species was observed in primary rat chondrocytes at higher concentration of monosodium iodoacetate （P 〈 0.05）. Significantly decreased levels of mitochondrial membrane potential were also shown in primary rat chondrocytes （P 〈 0.05）. Western blot assay revealed that monosodium iodoacetate significantly increased the release of cytochrome C and the protein expression of caspase-3, leading to cell apoptosis. Together these observations suggest that the mechanisms of monosodium iodoacetate-induced apoptosis are primarily via the production of reactive oxygen species and mitochondria- mediated caspase-3 activation in primary rat chondrocytes.