Role of inflammation in manganese-induced neurotoxicity

炎症在锰诱导的神经毒性中的作用

基本信息

批准号：
6779195
负责人：
NIKOLAY M FILIPOV
金额：
$ 10.74万
依托单位：
MISSISSIPPI STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-09-27 至 2006-07-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant) Studies suggest that environmental contaminants, include manganese (Mn), may contribute to Idiopathic Parkinson?s Disease (IPD), but the etiology of this disease still remains elusive. Two major sources of Mn pollution in the United States arise from the reintroduction of the fuel additive methylcyclopentadienyl manganese tricarbonyl and the widespread use of Mn-containing fungicides (maneb). Recently, the investigators obtained evidence that Mn, a neurotokicant causing Parkinson?s Disease-like symptoms, increases proinflammatory cytokines and nitric oxide production by activated microglia in vitro. These findings suggest that (i) inflammation plays a role in Mn-induced neurotoxicity, and (ii) Mn exposure may be a contributing factor (via enhanced production of inflammatory mediators) to IPD. The research proposed here will explore these possibilities utilizing both in vitro and in vivo approaches. Additional studies will begin to delineate the mechanism(s) by, which Mn enhances the inflammatory response in the brain. It is hypothesized that exposure to Mn, enhances activation of microglia which are disproportionately distributed in the brain and as a result, over-production of proinflammatory cytokines and nitric oxide occurs with the final outcome being selective neuronal loss in the basal ganglia. Furthermore, exposure to Mn in the context of an inflammatory stimulus would potentiate the dopaminergic neuronal damage in the 1-methyl-4-phenyl-1,2,3,4- tetrahydropyridline (MPTP) mouse model of PD. Microglial cell line (N9), as well as primary microglia, will be used to determine whether Mn speciation plays a role in the increased inflammatory response. Microglial (N9)-dopaminergic (PC 12) cell line co-cultures, as well as mesencephalic primary cultures will be used in vitro studies and the effects of Mn in the presence of a microglial activator (endotoxin, LPS) on neuronal cell death will be assessed. Additionally, Mn influence on the sensitivity of the dopaminergic neurons to MPTP under the same in vitro conditions will be evaluated. C57BL/6 (MPTP-sensitive) and CD-1 (MPTP-resistant) mice will be used for in vivo studies and animals will be treated similarly to the cell cultures in the in vitro studies. After short (14 days) exposure to Mn, some animals will be challenged with MPTP, and the degree of basal ganglia damage, as well as microglial activation will be assessed. Successful completion of the proposed research will help revealing the role of inflammation in Mn neurotoxicity and, more importantly, establish a mechanism by which environmental contaminants may contribute to the etiology of IPD. The long-term goal of the proposed studies is to understand the role of microglia and environmental contaminants in neurodegenerative diseases.

描述（由申请人提供）研究表明，环境污染物，包括锰（MN），可能会导致特发性帕金森氏病（IPD），但这种疾病的病因仍然难以捉摸。美国的MN污染的两个主要来源是重新引入燃料添加甲基甲基环丙烯酸锰三碳二烯二烯基三卡苯二烯和广泛使用含Mn的杀菌剂（MANEB）。最近，研究人员获得了证据表明，MN是导致帕金森氏病症状的神经动力学，可在体外通过活化的小胶质细胞增加促炎性细胞因子和一氧化氮的产生。这些发现表明（i）炎症在MN诱导的神经毒性中起作用，（ii）MN暴露可能是对IPD的炎症介体的产生（增强）的因素。这里提出的研究将利用体外和体内方法探索这些可能性。其他研究将开始描述机制，从而增强大脑的炎症反应。假设暴露于MN，增强了小胶质细胞的激活不成比例的分布在大脑中，因此，促炎细胞因子和一氧化氮的过量产生发生，最终结果是基底神经节的选择性神经元丧失。此外，在炎症性刺激的背景下暴露于MN会增强1-甲基-4-苯基1,2,3,4-四氢吡啶（MPTP）PD小鼠模型的多巴胺能神经元损伤。小胶质细胞系（N9）以及原发性小胶质细胞将用于确定MN物种形成是否在增加的炎症反应中起作用。小胶质细胞（N9） - 多巴胺能（PC 12）细胞系共培养以及中脑培养物以及中脑培养物将在体外研究中使用，并且将评估MN在小胶质细胞激活剂（内毒素，LPS）存在下对神经元细胞死亡的影响。此外，将评估MN对在同一体外条件下多巴胺能神经元对MPTP敏感性的影响。 C57BL/6（MPTP敏感）和CD-1（耐MPTP）小鼠将用于体内研究，并且动物将与IN中的细胞培养物相似。体外研究。在接触MN（14天）后，一些动物将受到MPTP的挑战，将评估基底神经节损伤的程度以及小胶质细胞激活。成功完成拟议的研究将有助于揭示炎症在MN神经毒性中的作用，更重要的是，建立了一种机制，通过该机制，环境污染物可能有助于IPD的病因。拟议的长期目标研究是了解小胶质细胞和环境污染物在神经退行性疾病中的作用。