镉对HEK 293细胞线粒体损伤作用  

Cadmium induced mitochondrial damage in HEK 293 cell

作　　者：毛伟平[1] 张娜娜[1] 魏传静[1] 周雷[1] 冯娟[1] 刘洪云[1] 

机构地区：[1]南京师范大学生命科学学院江苏省分子医学生物技术重点实验室,南京210046

出　　处：《中国公共卫生》2008年第12期1531-1533,共3页Chinese Journal of Public Health

基　　金：江苏教育厅自然科学基金(05KJD180111)

摘　　要：目的探讨线粒体在镉诱导人胚胎肾细胞(HEK293)凋亡中的作用。方法分离HEK293细胞的线粒体,采用分光光度法检测线粒体膜通透性转运孔(MPTP)的开放程度;电镜观察线粒体的形态改变;荧光分光光度法测定线粒体膜电位(MMP)和活性氧(ROS)含量的变化;ATP酶、谷胱甘肽过氧化物酶(GSH-Px)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)的活性及丙二醛(MDA)含量的测定。结果随着CdCl2浓度的增加,MPTP开放程度增加,并且这种增加能被MPTP特异性的抑制剂环孢素A(CsA)所抑制。电镜观察发现线粒体染镉后肿胀变形;中、高浓度CdCl2处理组线粒体膜电位都显著下降(P<0.05),ROS含量也显著增加(P<0.05和P<0.01)。在高浓度组,Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶活性下降,MDA含量随CdCl2处理浓度增高而增加,LDH、SOD、GSH-Px活性随CdCl2处理浓度增高而下降,差异均有统计学意义(P<0.01)。结论CdCl2破坏线粒体结构,引起MPTP的开放,MMP的降低,ROS含量增加,引起多种与凋亡相关的应激性损伤的发生。Objective To study the effect of cadmium on the structure and function of mitochondria in HEK 293 cell. Methods Mitochondria were isolated from cultured HEK 293 cells and treated with different concentration of CdCl2. Mitochondrial permeability transition pore （MPTP） was tested by spectrophotometer. Morphological changes of mitochondria were observed under transmission electron microscope. Mitochondrial membrane potential （MMP） was monitored by spectrofluorimeter with fluorescence dye Rh - 123, and the contents of ROS were detected by spectrofluorimeter with DCFH - DA. The activities of Na ^＋ - K ^＋ - ATPase, Ca^2 ＋ - Mg^2 ＋ - ATPase, superoxide dismutase （SOD）, glutathione peroxidase （GSH - Px） and the contents of malondialdehyde （MDA） were measured. Results MPTP of exposed groups decreased compared with that of the control group, and it can be inhibited by CsA. Mitochondria incubated with CdCl2 were found swell under transmis- sion electron microscope. In the groups of 5, 10 umol/L CdCl2, △ψm were destroyed（ P 〈 0.05） and the contents of ROS increased （P 〈 0.05 and P 〈 0.01 ）. In exposed groups, activities of ATP enzyme, LDH, SOD and GSH- Px declined with the increasing of CdCl2 concentration （high dose group P 〈 0.01）, and the contents of MDA increased（high dose group P 〈 0.01）. Conclusion CdCl2 could induce damage of mitochondria, the opening of the MPTP, the decrease of MMP and the increase of ROS, and cause the oxidative stress which is in close relationship with apoptosis.

关 键 词：氯化镉 线粒体膜通透性转运孔(MPTP) 线粒体膜电位 活性氧 凋亡 

分 类 号：R151.1[医药卫生—营养与食品卫生学]