内毒素对人脐静脉内皮细胞线粒动力学的影响

Effect of endotoxin on mitochondrial dynamics in human umbilical vein endothelial cells

目的探讨内毒素对人脐静脉内皮细胞线粒体动力学的影响。方法离体培养人脐静脉内皮细胞，接种于培养板，采用随机数字表法分为2组（n=54）：正常对照组（c组）和内毒素组（E组）。C组不做任何处理，E组加入终浓度为10Ixg／ml的脂多糖（LPS）。于LPS孵育2、8和24h时，采用MTT法测定细胞活力，采用磷钼酸比色法测定细胞内ATP含量，采用Westernblot法测定动力相关蛋白1（DRP1）的表达。结果与c组比较，E组孵育各时点细胞活力和ATP含量降低，DRP1表达上调（P〈0．05）。与LPS孵育2h时比较，E组孵育8h时细胞活力和ATP含量降低，DRP1表达上调，孵育24h细胞活力降低，DRP1表达下调（P〈0．05），ATP含量差异无统计学意义（P〉0．05）。与LPS孵育8h时比较，E组孵育24h时ATP含量升高，DRP1表达下调（P〈0．05），细胞活力差异无统计学意义（P〉0．05）。结论内毒素致人脐静脉内皮细胞线粒体损伤的机制与上调DRP1表达，促使线粒体过度分裂有关。

Objective To investigate the effect of endotoxin on mitoehondrial dynamics in human umbilical vein endothelial cells （HUVECs）. Methods HUVECs were cultured in vitro and seeded in the culture plate and randomly divided into 2 groups （n = 54 each） using a random number table： control group （group C） and endotoxin group （group E）. Lipopolysaecharides （LPS） with the final concentration of 10μg/ml was added in group E. At 2, 8 and 24 h of incubation with LPS, the cell viability was detec- ted using the methyl thiazolyl tetrazolium assay, the intracellular AT]：＇ content was determined by the phos- phomolybdic acid colorimetrie method, and the expression of the mitochondrial fission protein dynamin-related protein 1 （DRP1） was detected by Western blot. Results Compared with group C, the cell viability and ATP content were significantly decreased, and the expression of DRP1 was significantly up-regulated at each time point of incubation with LPS in group E （P〈0.05）. Compared with the values at 2 h of incubation with LPS, the cell viability and ATP content were significantly decreased, and the expression of DRP1 was significantly up-regulated at 8 h of incubation with LPS, the cell viability was significantly decreased, and the expression of DRP1 was significantly down-regulated at 24 h of incubation with LPS （P〈0.05） , and no significant change was found in the ATP content at 24 h of incubation with LPS in group E （P〉 0.05）. Compared with the values at 8 h of incubation with LPS, the ATP content was significantly increased, and the expression of DRP 1 was significantly down-regulated at 24 h of incubation with LPS （P〈0.05） , and no significant change was found in the cell viability at 24 h of incubation with LPS in group E （P〉0.05）. Conclusion The mechanism underlying endotoxin-induced mitochondrial damage in HUVECs is associated with up-regulation of DRP1 expression and promotion of excessive mitochondrial fission.