Neuroprotection Against Parkinsonian Cell Death

对抗帕金森细胞死亡的神经保护

• 批准号: 8305581
• 负责人: Jun Chen
• 金额: $ 30.62万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-30 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8305581
• 关键词: 1-Methyl-4-phenylpyridinium; Animal Model; Anti-Inflammatory Agents; Anti-inflammatory; Apoptosis; Apoptotic; Brain; Cell Death; Cell Line; Cell model; Cessation of life; Complement; Corpus striatum structure; Development; Dopaminergic Cell; Future; Genes; Goals; HSPB1 gene; Health; Heat shock proteins; Human; In Vitro; Inflammatory; Injury; Intoxication; MAPK14 gene; MAPK8 gene; Mediating; Microglia; Mitochondria; Modeling; Molecular Chaperones; Mus; Nerve Degeneration; Neurons; Neuroprotective Agents; Neurotoxins; Organism; Oxidative Stress; Parkinson Disease; Parkinsonian Disorders; Pathogenesis; Pathway interactions; Phosphorylation; Predisposition; Production; Property; Protein Family; Proteins; Reaction; Role; Serine; Shock; Signal Pathway; Signal Transduction; Substantia nigra structure; Testing; Therapeutic; Transfection; Transgenic Mice; Transgenic Organisms; Viral; Viral Vector; attenuation; cytokine; dopaminergic neuron; in vitro Model; in vivo; member; mutant; nervous system disorder; neuroinflammation; neuroprotection; neurotoxic; novel; novel therapeutics; overexpression; pars compacta; protein activation; stress protein; synuclein; treatment strategy

DESCRIPTION (provided by applicant): Parkinson's disease (PD) is characterized by progressive and selective loss of dopaminergic neurons in substantia nigra pars compacta. Although the pathogenesis of PD remains unclear, a breakthrough on this question has emerged from studies using animal models induced by Parkinsonian neurotoxins, such as MPTP, or viral-targeted overexpression of the PD-related brain-specific protein 1-Synuclein in the SNc. Evidence from different models suggests that the degeneration of dopaminergic neurons in PD is mediated at least in part via apoptosis-execution cascades. In addition, the neurotoxic activation of microglia may also contribute to dopaminergic neurodegeneration in PD. Thus, the long-term goal of this proposal is to identify novel neuroprotective agents that are capable of blocking the apoptosis-signaling pathways in dopaminergic neurons and the neurotoxic activation of microglia induced by Parkinsonian neurotoxins. HSP27 is a member of the small heat shock protein family, a group of ubiquitous stress proteins that are expressed in virtually all organisms. The expression of HSP27 is markedly induced in the brain after several forms of injury, and its neuroprotective role has been demonstrated. In addition to its known function as a protein chaperone, HSP27 has potent anti-apoptotic effects. It appears that HSP27 gains its anti-apoptotic properties after undergoing serine-specific phosphorylation, which can be induced by oxidative stress. However, the precise mechanism underlying the anti-apoptotic effect of HSP27 is not fully understood. We have created transgenic mice overexpressing either the wild-type HSP27 or a non-phosphorylatable HSP27 mutant. Using both transgenic and gene-transfection approaches, we have obtained exciting preliminary results which suggest that: 1) overexpression of HSP27 protects against dopaminergic cell death induced by Parkinsonian neurotoxins or by targeted overexpression of the neurotoxic human mutant (A53T) 1- Synuclein; 2) the neuroprotective effect of HSP27 is dependent on phosphorylation-mediated activation of the protein; and 3) HSP27 may achieve its neuroprotective effects via inhibiting both the ASK1/JNK-dependent mitochondrial death-signaling pathway in dopaminergic neurons and ASK1/p38-dependent pro-inflammatory reactions of microglia. This proposal attempts to further explore HSP27 as a neuroprotective molecule against dopaminergic cell death, with future therapeutic implications. The overall hypothesis underlying this proposal is that enhanced expression and phosphorylation- dependent activation of HSP27 protects against dopaminergic cell death via novel anti-apoptotic and anti-inflammatory mechanisms. We propose to test the hypothesis using both in vivo and in vitro models of PD. While the in vivo animal models mimic some important aspects of pathophysiological changes in PD, the in vitro cellular models will complement the in vivo studies by allowing for precise mechanistic studies. The following specific objectives are proposed: Aim 1. Test the hypothesis that transgenic overexpression and phosphorylation-dependent activation of HSP27 protects against dopaminergic cell death in the brain following Parkinsonian insults. Aim 2. Test the hypothesis that the direct neuroprotective effect of HSP27 against dopaminergic cell death is mediated via a novel anti-apoptotic mechanism involving the disruption of ASK1/JNK-dependent mitochondrial signaling pathways. Aim 3. Test the hypothesis that HSP27 protects against dopaminergic cell death via a second mechanism which involves the disruption of ASK1/p38- dependent pro-inflammatory signaling in brain microglia. PUBLIC HEALTH RELEVANCE: Parkinson's disease (PD) is characterized by progressive and selective loss of dopaminergic neurons in substantia nigra pars compacta, for which an effective neuroprotective treatment is currently unavailable. The objective of this proposal is to investigate whether enhanced expression of a small shock protein can ameliorate Parkinsonian neurotoxin-induced dopaminergic cell death in cellular and animal models of PD. This information will be valuable for future development of new therapeutic strategies for the treatment of Parkinson's disease and, possibly, other neurological disorders.

描述（由申请人提供）：帕金森病（PD）的特征是黑质致密部多巴胺能神经元进行性和选择性丧失。尽管帕金森病的发病机制仍不清楚，但使用帕金森神经毒素（例如 MPTP）或 SNc 中帕金森病相关脑特异性蛋白 1-Synuclein 的病毒靶向过度表达诱导的动物模型的研究在这个问题上取得了突破。来自不同模型的证据表明，PD 中多巴胺能神经元的退化至少部分是通过细胞凋亡执行级联介导的。此外，小胶质细胞的神经毒性激活也可能导致帕金森病中的多巴胺能神经变性。因此，该提案的长期目标是鉴定能够阻断多巴胺能神经元的凋亡信号通路以及帕金森神经毒素诱导的小胶质细胞的神经毒性激活的新型神经保护剂。 HSP27 是小型热休克蛋白家族的成员，该家族是一组普遍存在的应激蛋白，几乎在所有生物体中表达。在几种形式的损伤后，HSP27 的表达在大脑中显着诱导，并且其神经保护作用已被证明。除了其已知的蛋白质伴侣功能外，HSP27 还具有有效的抗凋亡作用。 HSP27 似乎在经历丝氨酸特异性磷酸化后获得了抗凋亡特性，丝氨酸特异性磷酸化可由氧化应激诱导。然而，HSP27 抗凋亡作用的确切机制尚不完全清楚。我们已经创建了过度表达野生型 HSP27 或不可磷酸化 HSP27 突变体的转基因小鼠。使用转基因和基因转染方法，我们获得了令人兴奋的初步结果，表明：1）HSP27的过度表达可以防止帕金森神经毒素或神经毒性人类突变体（A53T）1-突触核蛋白的靶向过度表达诱导的多巴胺能细胞死亡； 2) HSP27的神经保护作用依赖于磷酸化介导的蛋白质激活； 3) HSP27可能通过抑制多巴胺能神经元中ASK1/JNK依赖性线粒体死亡信号通路和小胶质细胞ASK1/p38依赖性促炎症反应来实现其神经保护作用。该提案试图进一步探索 HSP27 作为一种对抗多巴胺能细胞死亡的神经保护分子，并具有未来的治疗意义。该提议的总体假设是，HSP27 的表达增强和磷酸化依赖性激活可通过新的抗凋亡和抗炎机制防止多巴胺能细胞死亡。我们建议使用 PD 的体内和体外模型来检验该假设。虽然体内动物模型模拟了帕金森病病理生理变化的一些重要方面，但体外细胞模型将通过允许精确的机制研究来补充体内研究。提出以下具体目标： 目的 1. 检验以下假设：HSP27 的转基因过度表达和磷酸化依赖性激活可防止帕金森病损伤后大脑中的多巴胺能细胞死亡。目标 2. 检验以下假设：HSP27 对多巴胺能细胞死亡的直接神经保护作用是通过一种新颖的抗凋亡机制介导的，该机制涉及破坏 ASK1/JNK 依赖性线粒体信号通路。目标 3. 测试 HSP27 通过第二种机制防止多巴胺能细胞死亡的假设，该机制涉及破坏大脑小胶质细胞中 ASK1/p38 依赖性促炎症信号传导。 公共卫生相关性：帕金森病 (PD) 的特点是黑质致密部多巴胺能神经元进行性和选择性丧失，目前尚无有效的神经保护治疗方法。该提案的目的是研究小休克蛋白的表达增强是否可以改善帕金森病细胞和动物模型中帕金森神经毒素诱导的多巴胺能细胞死亡。这些信息对于未来开发治疗帕金森病以及可能的其他神经系统疾病的新治疗策略非常有价值。