Lou Di-dong, Zhang Kai-lin, Qin Shuang-li, Liu Yan-fei, Yu Yan-ni, Guan Zhi-zhong
Department of Pathology and Key Lab of Molecular Biology, Guiyang Medical College, Guiyang 550004, China.
Zhonghua Bing Li Xue Za Zhi. 2012 Apr;41(4):243-7. doi: 10.3760/cma.j.issn.0529-5807.2012.04.007.
To investigate the changes of mitochondrial distribution in axon/soma and the expression of mitochondrial fission 1 (Fis1) protein in the cortical neurons of rats with chronic fluorosis.
Sixty SD rats were divided into 3 groups (20 each) according to weight hierarchy and fed with different concentrations of fluoride in drinking water (0, 10 and 50 mg/L, respectively) for 6 months. Images of mitochondria and tubulin labeled by immunofluorescence COXIV and tubulin-α were captured with fluorescence microscope. Fis1 protein expression in cortical neurons was analyzed with immunohistochemistry and Western blot. The expression of Fis1 mRNA was detected with real-time PCR.
Varying degrees of dental fluorosis and increased fluoride contents in urine were observed in the rats receiving additional fluoride in drinking water. In the cortical neurons of rats fed with 10 mg/L and 50 mg/L fluoride, the numbers of neuronal soma stained with COXIV(34.8 ± 4.7 and 39.3 ± 3.0, respectively), and the expression of Fis1 protein (immunohistochemistry: 54.0 ± 3.6 and 51.3 ± 4.1, respectively; Western blot: 2.9 ± 0.4 and 2.6 ± 0.6, respectively) and mRNA (3773 ± 1292 and 1274 ± 162, respectively) was markedly increased as compared with controls (4.4 ± 2.3, 25.2 ± 2.5, 1.8 ± 0.2 and 277 ± 73) over the experimental period of 6 months.
Excessive intake of fluoride results in an altered mitochondrial distribution in axon and soma in cortical neurons (i.e., the increase in soma and the decrease in axon), increased expression of Fis1 gene and enhanced mitochondrial fission. The altered mitochondrial distribution may be related to the high expression level of Fis1 and a functional disorder of mitochondria.
探讨慢性氟中毒大鼠皮质神经元轴突/胞体中线粒体分布的变化以及线粒体分裂蛋白1（Fis1）的表达情况。
将60只SD大鼠按体重分层分为3组（每组20只），分别饮用含不同浓度氟化物的水（分别为0、10和50mg/L）6个月。用荧光显微镜采集免疫荧光标记的细胞色素氧化酶亚基Ⅳ（COXIV）和微管蛋白α标记的线粒体和微管图像。采用免疫组织化学和蛋白质印迹法分析皮质神经元中Fis1蛋白的表达。用实时聚合酶链反应检测Fis1 mRNA的表达。
饮用含氟水的大鼠出现了不同程度的氟斑牙，尿氟含量增加。在饮用10mg/L和50mg/L氟化物的大鼠皮质神经元中，COXIV染色的神经元胞体数量（分别为34.8±４.7和39.3±3.0）、Fis1蛋白表达（免疫组织化学：分别为54.0±3.6和51.3±4.1；蛋白质印迹法：分别为2.9±0.4和2.6±0.6）及mRNA（分别为3773±1292和1274±162）在6个月的实验期内与对照组（4.4±2.3、25.2±2.5、1.8±0.2和277±73）相比均显著增加。
过量摄入氟导致皮质神经元轴突和胞体中线粒体分布改变（即胞体增加而轴突减少）、Fis1基因表达增加及线粒体分裂增强。线粒体分布改变可能与Fis1高表达及线粒体功能紊乱有关。
