MOLECULAR MECHANISMS OF CELL DEATH IN PD MITOCHONDRIA

PD 线粒体细胞死亡的分子机制

• 批准号: 6664103
• 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/6664103
• 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.

特发性帕金森氏病（PD）遭受了约100万美国人的痛苦，在个人造成了广泛的苦难，并对社会对渐进运动残疾的产生产生了重大的经济损失。 PD症状是由黑质多巴胺神经元的过早和加速死亡引起的，通常用替代多巴胺突触功能的药物治疗。但是，尚无症状药物通过减慢人类多巴胺神经元的死亡来减少疾病进展。主要是通过编码电子传输链复合物I的线粒体基因缺陷进行的研究，导致氧化应激增加，细胞内钙信号传导的有害变化，线粒体复制和运动的改变以及增加对细胞死亡的敏感性，并增加了通过线粒体功能障碍介导的细胞死亡。该项目是帕金森研究中心的四个项目申请中的第三项基于实验室的研究。该项目将探索PD线粒体产生的细胞死亡的分子机制，该细胞死亡的遗传功能是分离并在该组开发和广泛研究的细胞质杂种（CYBRID）细胞模型中放大的。将PD Cybrids的结果与Rotenone产生的慢性复合物I损伤的药理模型进行比较。将检查四个具体目标，以测试相互关联的假设。首先，将研究线粒体膜电位的调节，以了解周期性的线粒体去极化 - 可极化，PI在PD中首先在神经细胞中首先描述的是PD。其次，将确定PD中过度表达抗凋亡蛋白Bcl-2和Bcl-XL对周期性线粒体去极化以及PD中线粒体膜电位降低的影响。第三，将线粒体去极化与Mapkinase Cascade的激活相关的分子机制将在对照和PD模型中定义。第四，将表征从PD和对照脑组织分离的线粒体过渡孔（MTP）复合物的特性。这些特性包括该组的最新发现，即人脑MTP复合物结合了细胞色素c。去极化诱导的细胞色素C的释放以及重组BCL蛋白和BH区域突变体的影响将在MTP-脂质体中研究。该项目与其他两个实验室项目进行了广泛的互动，并将开发模型系统来定义可能在PD中具有神经保护性的药物的作用机理。