压力作用下星形胶质细胞线粒体形态与功能异常的研究

Research on changes of mitochondria morphology and function under high pressure in rat astrocytes

目的研究压力对视网膜星形胶质细胞(RA)的损伤作用及可能的线粒体机制,为进一步阐明青光眼视神经损害的复杂分子机制提供实验数据。方法对体外培养的RA施加30 mm Hg(1 mm Hg=0.133kP a)压力,模拟慢性高眼压。分别在加压后不同时间点观察细胞线粒体形态及活性氧(ROS)含量变化,并收集细胞,制备细胞匀浆,采用生物化学方法检测5个线粒体呼吸链复合物(MRCC)和总超氧化物歧化酶(SOD)、Cu/Zn-SOD及Mn-SOD的活性变化。结果压力作用后,RA线粒体的分裂及ROS含量均增加;MRCCⅠ、Ⅱ、Ⅲ、Ⅳ的活性下降,MRCCⅤ的活性随加压时间的延长逐渐升高;各型SOD活性均降低,但Mn-SOD活性下降最迅速、幅度最大。结论压力可以引起RA线粒体形态和功能异常,导致RA内活性氧增加及抗氧化能力下降等损伤性变化。

Objective To investigate the damage of high pressure on retina astrocytes （RA） mitochondria and to explore the underlying mitochondrial mechanisms for further clarification of the complex molecular mechanisms of glaucoma optic nerve damage. Methods RA were cultured under 30 mm Hg pressure to mimic ocular chronic hypertension. Mitochondrial morphology and reactive oxygen species （ROS） level were observed by using the corresponding fluorescent probe at different time point. Mitochondrial complex and SOD activities were detected by biochemistry methods. Results The division of mitochondria and mount of ROS production both increased under high pressure. The activity of mitochondrial complex I,Ⅱ, Ⅲ, Ⅳ all declined while mitochondrial complex Vincreased with the prolonging of pressurization time. T-SOD, Cu/Zn-SOD and Mn-SOD activities all decreased, whereas Mn-SOD activities declined earliest and most significantly. Conclusions High pressure causes mitochondria morphology change and directly leads to mitochondrial dysfunction, resulting in the increase of ROS production and reduction of antioxidation ability in rat astrocytes.