锰中毒对海马齿状回成年神经发生的影响及机理研究

Manganism is a common occupational disease of local characteristics in Guangxi, in which the central nervous system is the most affected. A most recent study implies the involvement of DMT1 in manganese transportation in brain. Although neurogenesis of animal manganism model was attractive recently, its molecular mechanism is still unknown. Previously, we found that proliferation of adult neural stem cell was decreased in hippocampal SGZ by manganese exposure, being correlated with the dysfunction of learning and memory. Here we will combine in vitro neurosphere culture and animal models of Manganese exposure, to dissect out the specific effect of over-loading Manganese on the different stages of adult neuorogenesis in brain. Furthermore, we will detect the expression and activity of DMT1, JNK, ASK1, and growth factors such as BDNF, to clarify the molecular mechanism underlying the effect of Manganese exposure on adult neurogenesis using assays including multiple-labeling, PCR, Western blot. Moreover, we will employ distinct strategies of pharmacological inhibitor, RNAi, or overexpression to intervene the relevant signaling pathway, using biochemical, molecular, virus tools, and explore the potential and efficiency of these interventions. This work will improve our understanding on the mechanisms of Manganese exposure, clarify the specific roles of Mn on differeny stages of hippocampal neurogenesis, and help us to identify novel factors or signaling pathways, providing new molecular targets for the treatment of Manganese exposure.

锰中毒是常见职业病，主要损害神经系统，最新研究表明DMT1可能介导了锰在脑内的转运，锰中毒对神经发生影响的研究开始引起关注。我们前期研究发现，锰中毒可抑制成年脑内神经干细胞的分裂增殖，并与海马依赖的学习记忆障碍相关。本项目拟结合体外干细胞培养和在体锰中毒模型，利用荧光多标，比较锰中毒对海马SGZ区神经发生分化、存活和凋亡等不同阶段的具体影响及细胞学特点；依次用免疫多标、PCR和Western blot等方法检测DMT1的表达，观察JNK、ASK1-硫氧还蛋白通路蛋白、BDNF营养因子等分子的表达和活性改变，解析出锰致神经干细胞毒性的分子机制；进一步地结合药物抑制剂、RNAi、过表达等策略，综合生化、分子、病毒等方法干预相关信号通路，探讨其对锰的神经发生毒性的干预潜能和效果。本项目将有助于深入理解锰中毒的新机理，为锰致神经干细胞毒性提供科学理论基础，为开发临床防治新靶点和新策略提供实验依据。

锰中毒是长期从事锰矿相关工人的常见职业病，常因损害神经系统而严重影响生活质量，亟需探究新的发病机制与治疗策略。在本项目中，我们使用了在体/离体锰中毒模型，通过免疫荧光多标染色、Western Blotting等方法探索了锰的神经毒性作用；通过水迷宫等实验检测了行为学变化；结合Nestin-GFP转基因小鼠，离体培养了神经干细胞，通过脑内神经干细胞移植方法调控脑内神经发生，观察到锰中毒相关的神经系统损害症状得到缓解；分别通过在体实验、离体实验，观察到二价金属转运体1（DMT1）的表达受锰毒性作用影响，为探究锰发挥神经毒性潜在分子机制提供了新的线索；该研究为神经干细胞移植作为锰中毒潜在的治疗策略提供了一定的科学依据。