慢性氟中毒致神经系统损害及其线粒体损伤机制和保护干预

The recently studies on rats with chronic fluorosis have confirmed deteriorations of learning and memory with highly oxidative stress reputed to be one of the etiologies,but mechanisms is still unknown.So the present study is designed to evaluate the effects of choronic fluorosis on the morphology, synaptic disfuction, dynamic (in cluding fusion and fission proteins),fragementation, distribution of mitochondria as the main source of ROS on rats brain neurons, and the function of learning and memory on children on endemic fluorosis area, in an attempt to elucidate moleculare mechanisms underlying neurous damage associated with exess accumulation of fluoride. Moveover, the rat brain mitochondria protected by alpha lipoic acid to promote mitochondrial fussion are also designed to evaluated the function of mitochondria and the rats' learning and memory. Then, RNA interference and gene over expression technology carried out on the mitochondrial dynamic proteins of nevers cell in vitro to promote mitochondrial fussion are designed to evaluate whether the cells damages mentioned above are reduced. The all studies are aimed to probe the mechanisms of choronic fluorosis, and wheather protected mitochondria can reduce the damage of nerve cells with chronic flourosis and be a guide of the prevention and treatment for pations on endemic fluorosis？

目前动物研究认为慢性氟中毒时，可引起大鼠学习记忆功能下降，但是机制不明。大部分学者认为高氧化应激是发病的重要环节，而线粒体又是细胞产生ROS的主要原因之一。所以本课题将评估慢性氟中毒时大鼠神经细胞线粒体功能及慢性氟中毒儿童阅读记忆功能，并分析两者的关系。同时通过线粒体保护剂-硫辛酸，干预氟中毒大鼠，观察线粒体保护后大鼠的学习记忆功能和线粒体形态和功能。再通过线粒体融合分裂基因的干扰（基因超表达和RNA干扰技术），观察氟处理体外培养神经细胞内线粒体功能，在分子机制上阐述线粒体是否参与氟中毒发病机制。本项目将从动物水平和细胞水平探讨慢性氟中毒神经细胞的发病机制，同时评价通过线粒体保护能否降低氟对神经细胞的损伤，为广大患者提供预防和治疗的参考？

慢性氟中毒可引起神经系统的损伤，导致智力障碍。其主要的发生机制为过量氟蓄积导致细胞高氧化应激状态损伤细胞膜性成分。线粒体是重要的膜性细胞器，在高氧化应激状态下极易受攻击。所以本课题通过观察染氟后人脑神经母细胞瘤细胞(SH-SY5Y细胞)线粒体膜电位水平和线粒体融合蛋白1(Mfn1)、分裂蛋白1(Fis1)表达水平，探索氟致神经细胞损伤和凋亡的发病机制；通过基因干扰法，观察沉默Fis1基因对SH-SY5Y细胞的Fisl、Mfn1蛋白及线粒体膜电位水平的影响，探讨线粒体融合分裂在慢性氟中毒发病机制中的作用。同时对燃煤污染型氟中毒病区儿童智力水平进行调查，并分析两者的关系。结果发现：氟中毒损伤可引起神经细胞线粒体融合分裂水平改变并致线粒体膜电位下降，其改变可能与高氧化应激发病学说相关；人工抑制Fisl基因表达水平可降低氟致SH-SY5Y细胞的线粒体分裂和线粒体膜电位损伤；燃煤污染型氟中毒儿童可出现智力损害，对言语智力的损伤较为明显。科学意义主要为地方性氟中毒发病机制的研究和治疗提供参考，为线粒体保护剂预防和治疗地氟病患者神经功能障碍提供理论基础。