Mechanisms of Manganese Neurotoxicity

锰神经毒性机制

基本信息

批准号：
8318602
负责人：
Anumantha Gounder Kanthasamy
金额：
$ 32.32万
依托单位：
IOWA STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-08-05 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8318602
关键词：
Address Advanced Development Animal Model Apoptosis Apoptotic Astrocytes Basal Ganglia Biological Assay Brain region Catalytic Domain Cell Culture Techniques Cell Death Chronic Cleaved cell Corpus striatum structure Dominant-Negative Mutation Dose Drug Formulations Environmental Exposure Exposure to Family Funding Gasoline Gel Gene Expression Gene Proteins Genes Goals Health Incidence Industry Infant Food Knowledge Manganese Mediating Messenger RNA Metals Microglia Mitochondria Modeling Molecular Mus Neurologic Neurons Oxidation-Reduction Oxidative Stress Parkinsonian Disorders Pesticides Pharmaceutical Preparations Phosphotransferases Process Production Protein Isoforms Proteins Reaction Time Relative (related person)Research Role SP1 gene Signal Pathway Signal Transduction Sp1 Transcription Factor Structure Symptoms TNFRSF5 gene Time Toxic effect Transcriptional Regulation Up-Regulation Welding adeno-associated viral vector caspase-3 chromatin immunoprecipitation gene environment interaction knockout animal member mitochondrial dysfunction mouse model mutant nervous system disorder neurochemistry neuron apoptosis neurotoxic neurotoxicity novel overexpression promoter protein kinase C-delta response transcription factor translational approach

项目摘要

DESCRIPTION (provided by applicant): Chronic exposure to high concentrations of manganese (Mn) results in adverse neurological health effects commonly referred to as manganism. Manganese neurotoxicity is a significant toxicological problem resulting from the use of manganese as a gasoline additive, and in welding, metal industries, pesticide manufacturing, pharmaceutical preparations, infant food formulations, and battery production. Manganese predominantly accumulates in the basal ganglia structures and causes mitochondrial dysfunction, oxidative stress, and apoptosis. However, cellular and molecular mechanisms underlying manganese neurotoxicity are poorly understood. We have been studying mitochondrial-dependent apoptotic signaling in manganese neurotoxicity and found that protein kinase C-delta (PKCd), a member of the novel PKC isoform family, is persistently activated by caspase-3 to promote apoptosis during manganese exposure. While studying the apoptotic signaling pathway in cell culture models of manganese neurotoxicity, we also unexpectedly identified that PKCd is upregulated both in protein and mRNA levels during manganese treatment. Further analysis of the PKCd promoter revealed that two key transcription factors, NFkB and SP1, regulate PKCd gene expression. Thus, our competitive renewal proposal aims to systematically characterize this gene-environment interaction by studying novel molecular mechanisms underlying manganese-induced upregulation of the proapoptotic PKCd gene. We propose to complete the study by pursuing the following specific aims: i) To characterize upregulation of an oxidative stress-sensitive proapoptotic kinase PKCd in mouse primary neuronal cultures and animal models following manganese exposure, ii) To investigate molecular mechanisms of manganese-induced upregulation of PKCd by examining its transcriptional regulation of a PKCd promoter, and iii) To further define the functional role of NFkB and SP1-dependent PKCd upregulation in manganese-induced neuronal damage during chronic manganese exposure. Cellular, molecular, and neurochemical approaches in relevant cell cultures and animal models of manganese neurotoxicity will be used. We anticipate that the proposed study will provide comprehensive information about how environmental exposure to manganese can alter the expression of the key proapoptotic gene PKCd to augment manganese neurotoxicity, and this knowledge may advance the development of novel translational approaches for the treatment of manganese neurotoxicity.

描述（由申请人提供）：长期接触高浓度的锰 (Mn) 会导致神经系统健康受到不良影响，通常称为锰中毒。锰神经毒性是由于使用锰作为汽油添加剂以及在焊接、金属工业、农药制造、药物制剂、婴儿食品配方和电池生产中使用而引起的一个重要毒理学问题。锰主要积聚在基底神经节结构中，导致线粒体功能障碍、氧化应激和细胞凋亡。然而，人们对锰神经毒性的细胞和分子机制知之甚少。我们一直在研究锰神经毒性中线粒体依赖性细胞凋亡信号传导，发现蛋白激酶 C-δ (PKCd)（新型 PKC 亚型家族的成员）在锰暴露期间持续被 caspase-3 激活以促进细胞凋亡。在研究锰神经毒性细胞培养模型中的凋亡信号通路时，我们还意外地发现，在锰处理过程中，PKCd 的蛋白质和 mRNA 水平均上调。对 PKCd 启动子的进一步分析表明，两个关键转录因子 NFkB 和 SP1 调节 PKCd 基因表达。因此，我们的竞争性更新提案旨在通过研究锰诱导的促凋亡 PKCd 基因上调的新分子机制来系统地表征这种基因与环境的相互作用。我们建议通过追求以下具体目标来完成这项研究：i) 表征小鼠原代神经元培养物和动物模型中锰暴露后氧化应激敏感促凋亡激酶 PKCd 的上调，ii) 研究锰诱导上调的分子机制通过检查 PKCd 启动子的转录调控，进一步确定 NFkB 和 SP1 依赖性 PKCd 上调的功能作用慢性锰暴露期间锰引起的神经元损伤。将在相关细胞培养物和锰神经毒性动物模型中使用细胞、分子和神经化学方法。我们预计，拟议的研究将提供有关锰环境暴露如何改变关键促凋亡基因 PKCd 的表达以增强锰神经毒性的全面信息，并且这些知识可能会促进治疗锰神经毒性的新型转化方法的开发。