水通道蛋白8对脓毒症大鼠肝细胞线粒体形态的影响

Effect of aquaporin - 8 expression on the morphology of hepatocyte mitochondria in sepsis rats

目的研究脓毒症状态下大鼠肝细胞线粒体形态学的变化及线粒体水通道蛋白8（AQP8）的表达。方法将24只sD大鼠分成对照组和脓毒症组（每组12只）。采用盲肠结扎穿孔术（CLP）建立脓毒症实验动物模型，用Western印迹法检测大鼠肝细胞线粒体AQP8蛋白的表达，应用RT—PCR技术检测线粒体AQP8mRNA相对表达量；电镜下观察两组大鼠肝细胞线粒体的超微结构。结果脓毒症组大鼠肝细胞线粒体出现明显损伤；将对照组肝细胞线粒体AQP8蛋白相对表达水平设为1，则脓毒组AQP8蛋白表达水平为0．61±0．08，较对照组平均减少约39％，差异有统计学意义（P〈0．01）；将对照组肝细胞线粒体AQP8mRNA相对表达量设为1，脓毒组大鼠肝细胞线粒体AQP8mRNA相对表达量为1．59±0．24，较对照组平均增加约59％，差异也有统计学意义（P〈0．01）。结论脓毒症状态下，肝细胞线粒体出现肿胀、变性，线粒体AQP8蛋白表达下调可能是重要因素之一；由于机体的代偿作用，线粒体AQP8mRNA的表达是增加的。

Objective To study the alteration on the expression levels of protein and messenger RNA （mRNA） of aquaporin - 8 （ AQP8 ） in the liver mitochondria of rats with sepsis, and it plays a role in the change of mitochondrial morphology. Methods 24 SD rats were divided into two groups randomly, the control group and the septic group, 12 rats being in each group. The septic model was made by cecal ligation and puncture. The expression of AQP8 in the hepatocyte mitochondria was detected using western blot. The expression of AQP8 mRNA in the hepatocyte mitochondria was assayed by reverse transcription - polymerase chain reaction. And the mitochondrial uhrastructure of rat liver was observed by electron microscope. Results The mitochondrial uhrastructure was damaged significantly in the septic group. To set the AQP8 protein level to 1 in the control group, the AQP8 protein level was 0.61 ± 0.08 in the septic group, it decreased about 39% than that in the control group （ P 〈 0.01 ）. To set the AQP8 mRNA level to 1 in the control group, the AQP8 mRNA level was 1.59 ± 0.24 in the septic group, it significantly increased about 59% than that in the control group （ P 〈 0. 01 ）.Conclusion The expression of AQP8 was down -regulated in the rat hepatocyte mitochondria with sepsis, and it might led to swelling and degeneration of mitochondria. Due to the compensatory mechanism, AQP8 mRNA levels was increased.