Role of inflammation in manganese-induced neurotoxicity

炎症在锰诱导的神经毒性中的作用

• 批准号: 6665194
• 负责人: NIKOLAY M FILIPOV
• 金额: $ 10.57万
• 依托单位: MISSISSIPPI STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-27 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6665194
• 关键词: basal ganglia; biological signal transduction; cytokine; environmental contamination; immunocytochemistry; inflammation; laboratory mouse; manganese; metal poisoning; methylphenyltetrahydropyridine; microglia; neural degeneration; neuroimmunomodulation; neurotoxicology; neurotoxins; nitric oxide; nitric oxide synthase; substantia nigra; tissue /cell culture; western blottings

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)，可能与特发性帕金森-S病(IPD)有关，但该疾病的病因仍不清楚。美国锰污染的两个主要来源是重新引入燃料添加剂甲基环戊二烯基锰三羰基锰和广泛使用 含锰杀菌剂(Maneb)。最近，研究人员获得证据表明，引起帕金森-S病样症状的神经刺激因子锰在体外通过激活小胶质细胞增加促炎细胞因子和一氧化氮的产生。这些发现表明：(1)炎症在锰诱导的神经毒性中起作用，(2)锰暴露可能是导致IPD的一个因素(通过增加炎性介质的产生)。这里提出的研究将利用体外和体内方法来探索这些可能性。更多的研究将开始描述锰增强大脑炎症反应的机制(S)。据推测，暴露于锰会增强小胶质细胞的激活，而小胶质细胞 在大脑中的分布不成比例，其结果是，促炎细胞因子和一氧化氮的过度产生，最终结果是选择性地在基底节失去神经元。此外，在炎性刺激的背景下暴露于锰将加强1-甲基-4-苯基-1，2，3，4-四氢吡啶(MPTP)帕金森病小鼠模型的多巴胺能神经元的损伤。小胶质细胞系(N9)以及原代小胶质细胞将被用来确定锰的形态是否在炎症反应增加中起作用。小胶质细胞(N9)-多巴胺能(PC 12)细胞系共培养以及中脑原代培养将用于体外研究，并将评估在小胶质细胞激活剂(内毒素，LPS)存在的情况下锰对神经细胞死亡的影响。此外，还将在相同的体外条件下评价锰对多巴胺能神经元对MPTP敏感性的影响。C57BL/6(MPTP敏感)和CD-1(MPTP耐药)小鼠将用于体内研究，动物将受到与体内细胞培养相似的治疗 体外研究。在短时间(14天)暴露于锰后，一些动物将被MPTP激发，并将评估基底节损伤的程度以及小胶质细胞的激活。这项拟议研究的成功完成将有助于揭示炎症在锰神经毒性中的作用，更重要的是，建立环境污染物可能有助于IPD病因的机制。建议的长期目标 研究是为了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。