Toxicant-induced synaptic dysfunction and neurotoxicity in Parkinson disease

帕金森病中毒物引起的突触功能障碍和神经毒性

基本信息

批准号：
8696921
负责人：
KIM TIEU
金额：
$ 19.09万
依托单位：
UNIVERSITY OF PLYMOUTH
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-20 至 2018-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8696921
关键词：
3-Dimensional Acute Animal Model Animals Attenuated Cell Count Cell Culture Techniques Cell Death Complement Complex Corpus striatum structure Cytosol Data Dominant-Negative Mutation Dopamine Dyes Electron Microscopy Electrophysiology (science)Environment Environmental Risk Factor Epidemiologic Studies Epidemiology Equilibrium Equipment Exposure to Functional disorder Gene Mutation Gene Proteins Genes Genetic Genus Hippocampus Goals Grant Herbicides High Pressure Liquid Chromatography Human Immunoelectron Microscopy Immunohistochemistry Individual Injection of therapeutic agent Insecticides Lesion Light Link Location Measures Membrane Potentials Meperidine Methods Microdialysis Midbrain structure Mitochondria Mitochondrial Electron Transport Complex I Modeling Monitor Morphology Motor Motor Activity Movement Mus Mutant Strains Mice Mutation Nerve Degeneration Neurons Neurotoxins Organelles Organic Cation Transporter Oxidation-Reduction Oxidative Stress Oxygen Consumption Paraquat Parkinson Disease Parkinsonian Disorders Pathogenesis Patients Pesticides Play Process Proteins Rattus Recombinant adeno-associated virus (rAAV)Respiration Risk Rodent Model Role Rotenone Serotyping Shapes Slice Superoxides Synapses Techniques Testing Time Toxic Environmental Substances United States Variant Western Blotting base cytochrome c density disease diagnosis dopaminergic neuron extracellular gene environment interaction in vivo inhibitor/antagonist insight interest laser capture microdissection mitochondrial dysfunction mitochondrial membrane nervous system disorder neuropathology neurorestoration neurotoxic neurotoxicity new therapeutic target nigrostriatal pathway novel novel therapeutics protein aggregation public health relevance small molecule synaptic function therapeutic target tool toxicant trafficking vector

项目摘要

DESCRIPTION (provided by applicant): Our long term goal is to study the mechanisms of neurodegeneration induced by environmental toxicants, genetic mutations and potential gene-environment interactions to gain insights into the pathogenesis of Parkinson's disease (PD). Advances in the genetics of PD have highlighted the critical role of mitochondrial dynamics (fission / fusion / movement) in neuronal function and survival. However, because monogenic familial PD represents only a small fraction of PD cases, it is critical to determine whether perturbed mitochondrial dynamics also plays a role in the nigrostriatal damage induced by environmental neurotoxicants. Most of these exogenous toxic molecules cause mitochondrial dysfunction either directly by blocking mitochondrial respiration, or indirectly through oxidative stress. Based on our preliminary data, this proposal will utilize two complementary toxicant-based animal models of nigrostriatal neurodegeneration: A) The herbicide paraquat (PQ) induces cell death primarily through oxidative stress. B) The pesticide/insecticide rotenone directly inhibits mitochondrial function. We hypothesize that whether excessive mitochondrial fission and dysfunction is induced directly by blocking mitochondrial respiration (rotenone) or indirectly by oxidative stress (PQ), promoting mitochondrial fusion will attenuate pre-synaptic dysfunction and neurotoxicity seen in these animal models. In Aim 1, we will investigate the impact of promoting mitochondrial fusion in the PQ mouse and rotenone rat models. Because PQ does not induce striatal damage in regular mice, we will use our novel mutant mice with deletion of the organic cation transporter 3 (Oct3-/-) to create a PQ animal model with damage in both nigra and striatum, as well as to enhance relevance to human gene-environment interactions because OCT3 variants have been associated with PD. Small molecule and gene-based approaches will be used for manipulation of mitochondrial fission/fusion machinery. Both neurorestorative and neuroprotective effects of these strategies will be determined in animals with pre-existing lesions and with active neurodegeneration. Striatal mitochondrial function, evoked striatal dopamine release in freely moving animals, synaptic function using electrophysiology, motor function and the integrity of the nigrostriatal pathway will be analyzed. In Aim 2, we will investigate the mechanisms by which PQ and rotenone induce mitochondrial fission and why blocking this process is protective. Where relevant, both animal models and cell cultures will be used. A wide range of state-of-the art equipment/techniques such as 3-dimensional electron microscopy, laser capture microdissection, the Seahorse extracellular flux analyzer and amperometry will be used to quantify alterations in levels of proteins/genes of interest specifically in nigral dopaminergic neurons, mitochondrial trafficking/morphology/function and synaptic density/function. Accomplishment of these aims will provide critical information regarding how toxic insults impact nigrostriatal pathway through perturbed mitochondrial dynamics and offer insights into a potential novel therapeutic target for PD.

描述（由申请人提供）：我们的长期目标是研究由环境有毒物质，遗传突变和潜在的基因环境相互作用引起的神经退行性的机制，以洞悉帕金森氏病（PD）的发病机理。 PD遗传学的进步突出了线粒体动力学（裂变 /融合 /运动）在神经元功能和生存中的关键作用。但是，由于单基因家族性PD仅代表PD病例的一小部分，因此确定扰动的线粒体动力学是否也在环境神经毒性引起的鼻叶层损伤中起作用，这一点至关重要。这些外源性毒性分子中的大多数直接通过氧化应激直接阻断线粒体呼吸或间接阻止线粒体呼吸引起线粒体功能障碍。基于我们的初步数据，该提案将利用两种基于互补的毒物神经变性的动物模型：a）除草剂帕拉菌（PQ）（PQ）主要通过氧化应激诱导细胞死亡。 b）农药/杀虫剂罗替酮直接抑制线粒体功能。我们假设，是否通过阻断线粒体呼吸（藤酮）还是通过氧化应激（PQ）直接诱导过度的线粒体裂变和功能障碍，从而促进线粒体融合会促进这些动物模型中的突触前功能障碍和神经毒性。在AIM 1中，我们将研究促进PQ小鼠和烤面包酮大鼠模型中线粒体融合的影响。由于PQ不会在常规小鼠中诱导纹状体损伤，因此我们将使用具有有机阳离子转运蛋白3（OCT3 - / - ）缺失的新型突变小鼠，以创建具有NIGRA和纹状体损害的PQ动物模型，以及对由于OCT3变体与PD相关，因此增强了与人类基因环境相互作用的相关性。小分子和基于基因的方法将用于操纵线粒体裂变/融合机械。这些策略的神经训练和神经保护作用均应在具有预先存在病变和活性神经变性的动物中确定。纹状体线粒体功能，自由移动动物中诱发的纹状体多巴胺释放，使用电生理学，运动功能，运动功能和鼻叶途径的完整性的突触功能将进行分析。在AIM 2中，我们将研究PQ和Rotenone诱导线粒体裂变的机制，以及为什么阻止此过程具有保护性。在相关的情况下，将使用动物模型和细胞培养物。多种最先进的设备/技术，例如三维电子显微镜，激光捕获显微解剖，海马外细胞外通量分析仪和安培计量法将用于量化nigral多巴胺疗法的蛋白质/蛋白质水平/蛋白质水平的变化神经元，线粒体运输/形态/功能和突触密度/功能。这些目标的完成将提供有关有毒损伤如何通过扰动的线粒体动力学影响黑质纹状体途径的关键信息，并为PD的潜在新型治疗靶点提供见解。