MOLECULAR MECHANISMS OF CELL DEATH IN PD MITOCHONDRIA

PD 线粒体细胞死亡的分子机制

• 批准号: 6618257
• 负责人: JAMES PEPPER BENNETT
• 金额: $ 23.19万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6618257
• 关键词: Parkinson's disease; apoptosis; cell line; clinical research; disease /disorder etiology; disease /disorder model; electron transport; gene expression; human genetic material tag; human tissue; hybrid cells; membrane potentials; mitochondrial DNA; mitochondrial membrane; mitogen activated protein kinase; molecular pathology; neuropathology; oxidative stress; postmortem; protooncogene; respiratory enzyme

Idiopathic Parkinson's disease (PD) afflicts about 1 million Americans, causes widespread suffering in the individuals, and exacts a significant economic toll on society from its production on progressive motor disability. PD symptoms arise from the premature and accelerated death of substantia nigra dopamine neurons and are commonly treated with drugs that replace dopamine synaptic function in the nigrostriatal pathway. However, no available symptomatic drugs have been shown to reduce disease progression by slowing the death of dopamine neurons in humans. Studies performed mainly by the defect in mitochondrial genes coding for complex I of the electron transport chain is responsible for increased oxidative stress, detrimental changes in intracellular calcium signaling, altered mitochondrial replication and movement, and increased susceptibility to cell death mediated by mitochondrial dysfunction. This Project is the third laboratory-based study in a four Project application for a Parkinson's Research Center of Excellence. This Project will explore the molecular mechanisms of cell death produced by PD mitochondria whose genetic functions are isolated and amplified in the cytoplasmic hybrid (cybrid) cell model developed and extensively studied by this group. Results in PD cybrids will be compared to a pharmacological model of chronic complex I impairment produced by rotenone. Four Specific Aims will be examined that test interrelated hypotheses. First, the regulation of mitochondrial membrane potential will be studied with respect to the how cyclical mitochondrial depolarization-repolarization, first described in neural cells by the PI's laboratory, is altered in PD. Second, the effects of over-expressing the anti-apoptotic proteins bcl-2 and bcl-XL on cyclical mitochondrial depolarization and reduced mitochondrial membrane potential in PD will be determined. Third, the molecular mechanisms connecting mitochondrial depolarization to activation of MAPKinase cascade will be defined in control and PD models. Fourth, properties of mitochondrial transition pore (MTP) complexes isolated from PD and control brain tissues will be characterized. These properties included the very recent finding from this group that human brain MTP complexes bind cytochrome c. Depolarization-induced release of cytochrome c and the influence of recombinant bcl proteins and BH region mutants will be studied in MTP-liposomes. This project interacts extensively with the other two laboratory projects and will develop model systems to define mechanisms of action for drugs that might be neuroprotective in PD.

特发性帕金森病 (PD) 困扰着约 100 万美国人，给个人带来广泛的痛苦，并因其造成进行性运动残疾而对社会造成重大经济损失。 PD 症状由黑质多巴胺神经元过早和加速死亡引起，通常用替代黑质纹状体通路中多巴胺突触功能的药物治疗。然而，尚无可用的对症药物被证明可以通过减缓人类多巴胺神经元的死亡来减少疾病进展。主要通过编码电子传递链复合物 I 的线粒体基因缺陷进行的研究，导致氧化应激增加、细胞内钙信号传导发生有害变化、线粒体复制和运动改变以及线粒体功能障碍介导的细胞死亡的易感性增加。该项目是帕金森病卓越研究中心四个项目申请中的第三个基于实验室的研究。该项目将探索PD线粒体产生细胞死亡的分子机制，其遗传功能在该小组开发和广泛研究的细胞质杂合（cybrid）细胞模型中被分离和放大。 PD cybrids 的结果将与鱼藤酮产生的慢性复合物 I 损伤的药理学模型进行比较。将检查四个具体目标来检验相互关联的假设。首先，将研究线粒体膜电位的调节，以了解周期性线粒体去极化-复极化（PI 实验室首次在神经细胞中描述）在 PD 中如何改变。其次，将确定过度表达抗凋亡蛋白 bcl-2 和 bcl-XL 对 PD 中周期性线粒体去极化和线粒体膜电位降低的影响。第三，将在对照和 PD 模型中定义连接线粒体去极化与 MAPK 激酶级联激活的分子机制。第四，将从 PD 和对照脑组织中分离的线粒体过渡孔 (MTP) 复合物的特性进行表征。这些特性包括该小组最近发现人脑 MTP 复合物结合细胞色素 c。将在 MTP 脂质体中研究去极化诱导的细胞色素 c 释放以及重组 bcl 蛋白和 BH 区域突变体的影响。该项目与其他两个实验室项目广泛互动，并将开发模型系统来定义可能对帕金森病具有神经保护作用的药物的作用机制。