Extra-nigral Neurodegeneration in Experimental Parkinson's Disease

实验性帕金森病的黑外神经变性

基本信息

批准号：
8536961
负责人：
NAREN L BANIK
金额：
$ 30.34万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-20 至 2015-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8536961
关键词：
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine 1-Methyl-4-phenylpyridinium Acute Affect Age Animal Model Animals Antibodies Apoptosis Apoptotic Astrocytes Attenuated Autopsy Axon Behavioral Biochemical Bradykinesia Brain Brain Injuries C57BL/6 Mouse Calcium Calpain Cell Death Cell Survival Cell membrane Cell physiology Cells Cessation of life Chronic Data Detection Development Disease Disease Progression Dopa Esthesia Etiology Event Experimental Models Experimental Parkinsonism Exposure to Fiber Functional disorder Goals Human Immunofluorescence Immunologic In Situ Nick-End Labeling In Vitro Inflammation Inflammatory Interferons Label Lead Levodopa Measures Mediating Membrane Potentials Microglia Mitochondria Modeling Monoamine Oxidase B Motor Neurons Motor Pathways Movement Movement Disorders Mus Myelin Nerve Degeneration Neuroglia Neurons Neurotoxins PTGS2 gene Parkinson Disease Parkinsonian Disorders Pathogenesis Pathology Patients Play Process Rest Role SJA6017 Sampling Spinal Cord Staining method Stains Substantia nigra structure Symptoms Techniques Testing Therapeutic Agents Time Tissues Toxin Tremor Up-Regulation axonal degeneration base calpain inhibitor calpeptin cell injury cell type cytochrome c functional restoration improved functioning in vivo insight mitochondrial dysfunction mouse model myelin degeneration neurotoxic new therapeutic target novel therapeutics prevent public health relevance response restoration white matter white matter change white matter damage

项目摘要

Parkinson's disease (PD), a progressive degenerative movement disorder associated with loss of dopaminer- gic neurons in substantia nigra (SN), leads to dysfunction. The current therapy, L-dopa, does not block dis- ease progression; therefore, new therapies must be developed. Thus, the aim is to investigate inflammatory events in brain and spinal cord (SC) and their degeneration in PD and characterize whether SC integrity and neurons are lost in PD, contributing to dysfunction. Understanding the mechanisms of damage may help de- velop new therapeutic strategies. While the etiology of PD is not fully understood, neurotoxins have been im- plicated in PD pathogenesis. Toxic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been extensively used as an experimental model. Since 1-methyl-4-phenylpyridinium ion (MPP+), the active toxic metabolite of MPTP, increases intracellular-free Ca2+ level and promotes mitochondrial dysfunction, a Ca2+-mediated pathol- ogy in PD has been hypothesized. Increased Ca2+ levels will promote calpain activation, increase inflamma- tory responses, and damage brain/SC neurons, axons, and myelin, ultimately leading to functional deficit. Our preliminary findings of direct detection of MPP+ in PD mouse SC, activation of astrocytes and microglia, and increased calpain activity and expression in neurons indicate that SC is also affected. These findings were corroborated by preliminary data showing motoneurons from SC of PD patients are also damaged. MPP+ treatment of ventral SC motor neuron cells (VSC4.1) showed increased intracellular [Ca2+] and calpain activity with loss of membrane potential and death while calpain inhibitors (calpeptin, SJA6017) protected and restored cell function. From these findings, we hypothesize that, since SC coordinates movement and sensation of the body, damage to SC neurons, axons, and myelin, in addition to SN, may be an important factor in PD, and calpain plays a crucial role in this dysfunction by promoting inflammation and cell death and may be a target for therapy. Three specific aims will test the hypotheses. Specific Aim 1 will investigate whether MPTP is directly converted into MPP+ in SC, enters through the degenerating axons from brain, or a combination of both; examine the effects of MPTP (MPP+) on SN and SC neurons and white matter in acute and chronic parkinsonism; assess calpain expression and activity and subsequent inflammation and cell damage; and examine the status of neurons, axons, and myelin in SC of postmortem PD patients. Specific Aim 2 will explore the effects of neurotoxic MPP+ in differentiated VSC4.1 cells and test the neuroprotective efficacy of calpain inhibitors in vitro employing electrophysiological technique. Specific Aim 3 will examine whether calpain inhibitor treatment will attenuate inflammation, prevent apoptosis of brain and SC neurons, protect cells, preserve axons and myelin, and improve function in MPTP-induced PD mice. These studies will delineate the role of calpain in inflammation and neurodegeneration in MPTP-induced PD and the probable neuroprotective efficacy of calpain inhibitors in PD as therapeutic agents.

帕金森氏病（PD），这是一种逐渐退化性运动障碍黑质（SN）的GIC神经元导致功能障碍。当前的疗法L-DOPA不会阻塞放松进展；因此，必须开发新的疗法。因此，目的是调查炎症大脑和脊髓（SC）中的事件及其在PD中的变性，并表征SC的完整性和是否表征神经元在PD中丢失，导致功能障碍。了解损害的机制可能有助于消除天线新的治疗策略。尽管尚未完全了解PD的病因，但神经毒素已经存在在PD发病机理中涂上。有毒1-甲基-4-苯基1,2,3,6-四氢吡啶（MPTP）已广泛用作实验模型。由于1-甲基-4-苯基吡啶丁离子（MPP+），因此活性有毒代谢物的 MPTP增加了无细胞内Ca2+水平并促进线粒体功能障碍，Ca2+介导的病理学 PD中的OGY已被假设。 Ca2+水平升高将促进钙蛋白酶的激活，增加炎症 - 保守党反应以及损害脑/SC神经元，轴突和髓磷脂的损害，最终导致功能不足。我们的 PD小鼠SC中MPP+直接检测的初步发现，星形胶质细胞和小胶质细胞的激活以及钙蛋白酶活性的增加和神经元的表达表明SC也受到影响。这些发现是通过初步数据证实，显示PD患者SC的运动神经元也受损。 MPP+ 腹侧SC运动神经元细胞（VSC4.1）的治疗显示细胞内[Ca2+]和钙蛋白酶活性增加随着膜潜力和死亡的损失，钙蛋白酶抑制剂（Calpeptin，SJA6017）受到保护并恢复细胞功能。从这些发现中，我们假设，因为SC会坐标运动和感觉身体，SC神经元，轴突和髓磷脂的损害，除SN外，可能是一个重要因素在PD中，Calpain通过促进炎症和细胞死亡在这种功能障碍中起着至关重要的作用并可能是治疗的目标。三个具体目标将检验假设。具体目标1将调查 MPTP是否直接转换为SC中的MPP+，通过大脑的退化轴突进入两者的结合；检查MPTP（MPP+）对急性中SN和SC神经元以及白质的影响和慢性帕金森主义；评估钙蛋白酶表达和活性以及随后的炎症和细胞损害;并检查神经元，轴突和髓磷脂的状态在验尸PD患者的SC中。具体的 AIM 2将探索神经毒性MPP+在分化的VSC4.1细胞中的影响并测试神经保护作用钙蛋白酶抑制剂在体外采用电生理技术的功效。具体目标3将检查钙蛋白酶抑制剂治疗是否会减轻炎症，防止大脑和SC神经元凋亡，保护细胞，保存轴突和髓磷脂，并改善MPTP诱导的PD小鼠的功能。这些研究会描述钙蛋白酶在MPTP诱导的PD中的炎症和神经变性中的作用 Calpain抑制剂在PD中作为治疗剂的神经保护功效。