微囊藻毒素-LR对小鼠肝细胞线粒体功能的影响

Exploring the Effects of MC-LR on Mitochondrial Function in Mouse Liver

目的:探究微囊藻毒素-LR对小鼠肝细胞线粒体功能的影响。方法:采用BALB/c小鼠作为模型动物,随机分为3组:A组,空白对照组,正常饮用水;B组,添加5 g/L微囊藻毒素-LR的饮用水;C组,添加30 g/L微囊藻毒素-LR的饮用水。分组喂养3个月,分离小鼠肝脏、提取线粒体,采用线粒体荧光探针JC-1测定线粒体膜电位(MMP),qRT-PCR检测自噬相关基因Beclin1和Lc3α的转录水平,Western Blot检测细胞色素C的释放,电镜观察线粒体的形态和内部结构。结果:微囊藻毒素-LR处理组的小鼠肝细胞线粒体膜电位明显下降,自噬相关基因Lc3α的转录水平上升,细胞色素C由线粒体释放到胞浆,电镜观察线粒体形态异常、内部结构被破坏。结论:微囊藻毒素-LR对小鼠肝细胞线粒体有较强的毒性作用,并引发线粒体自噬。

Objective： To investigate the effects of MC-LR on mitoehondria isolated from mouse liver. Methods： The mice were randomly divided into 3 groups： Group A were fed with tap water, Group B were fed with the water containing 5 μg/L MC-LR, while Group C were fed with water containing 30 btg/L MC-LR for 3 months respectively. Mitochondria were isolated from mouse liver, and mitophagy was detected through mitochondrial membrane potential by using JC-1, which was widely used in apoptosis studies to monitor mitochondrial health. After extracting RNA from the mouse liver, transcriptional levels of autophagy-related genes Beclinl and Lc3α were measured by qRT-PCR. The release of cytoehrome C from mitoehondria to plasma was detected by Western Blot. The morphology of mitochondria was observed by electron microscope. Results： Compared with the mitochondrial uncoupler carbonyl cyanide m-chlorophenylhydrazone （CCCP）, mitochondrial membrane potential declined obviously. The transcriptional level of Lc3α increased correspondingly, while that for Beelinl was not significant. Cytochrome C was released from mitoehondria to the plasma. The abnormality of mitochondria could be detected clearly by electron microscope, and some mitochondria were tending to fall apart. Conclusions： Mitophagy could be induced in mouse liver after the treatment of MC-LR, which indicated that MC-LR had severe mitochondrial toxicity in mouse liver.