The interaction between ATP13A2 and alpha-synuclein in mice

描述（由申请人提供）：随着与帕金森综合征相关的新基因的持续鉴定，该领域的一个迫切问题是了解这些基因是否相互作用导致帕金森病的主要特征的发展。这种信息的缺乏是一个重要的问题，因为它限制了对帕金森病潜在的共同机制的理解，从而也限制了新的疾病修饰治疗的发展。长期目标是通过确定可以预防或显著减缓疾病进展的新型治疗靶点来改善帕金森病的治疗结果。该特定应用的目的是确定遗传基因座ATP 13 A2（PARK 9）和α-突触核蛋白（PARK 1）如何相互作用，特别是ATP 13 A2的功能丧失如何影响小鼠中的α-突触核蛋白毒性。ATP 13 A2无效和α-突触核蛋白过表达小鼠各自显示出行为障碍和解剖病理学方面，这让人想起在帕金森病中所见的，突出了它们的有用性。核心假设是ATP 13 A2功能丧失增强α-突触核蛋白毒性，导致体内多巴胺能细胞损失和功能损伤加速。该假设是根据申请人实验室的初步和已发表的研究制定的。这项研究的基本原理是，一旦确定了与细胞和行为功能障碍相关的病理机制，就可以开始开发潜在的治疗方法。在初步数据的指导下，将通过追求两个特定目标来测试该假设：1）确定ATP 13 A2的损失和体内1-突触核蛋白蛋白负荷增强之间的相互作用的功能效应。2)检验小鼠中ATP 13 A2功能丧失联合α-突触核蛋白过表达导致溶酶体功能障碍、α-突触核蛋白异常蓄积增加和体内黑质纹状体多巴胺神经元死亡加速的假设。在第一个目的中，将由申请人的实验室产生的ATP 13 A2无效小鼠和过表达α-突触核蛋白的小鼠杂交以产生过表达α-突触核蛋白的双突变体ATP 13 A2无效小鼠。这些小鼠将在申请人实验室设计和建立的测试中随着年龄的增长接受行为障碍测试。在目标二中，免疫组织化学技术、神经化学分析和体视学技术的组合将用于测量多个年龄段的脑溶酶体蛋白、α-突触核蛋白和黑质纹状体病理学。所提出的方法是创新的，因为它侧重于在体内环境中与帕金森症相关的两个遗传基因座之间的相互作用。拟议的研究是重要的，因为它是一系列研究的第一步，预计将导致识别有助于PD发展的机制，并提供一个模型来测试针对这些机制的潜在治疗方法。 公共卫生相关性：拟议的研究与公共卫生有关，因为发现与遗传形式的帕金森病相关的基因如何相互作用最终有望增强对与这种进行性疾病相关的致病机制的理解，并导致疾病修饰干预措施的发展。拟议的研究与NIH的使命的一部分有关，该使命旨在开发有助于减轻人类残疾负担的知识。

DESCRIPTION (provided by applicant): With the continued identification of novel genes associated with Parkinsonism an imperative question in the field is to know whether these genes interact to lead to the development of the cardinal features of Parkinson's disease. This lack of information is an important problem because it limits the understanding of potential common mechanisms underlying Parkinson's disease thus also limiting the development of novel disease-modifying treatments. The long-term goal is to improve treatment outcomes in Parkinson's disease by identifying novel therapeutic targets that can prevent or significantly slow the progression of the disease. The objective in this particular application is to determine how the genetic loci ATP13A2 (PARK9) and alpha-synuclein (PARK1) interact, specifically how does the loss of function of ATP13A2 affect alpha-synuclein toxicity in mice. ATP13A2 null and alpha-synuclein overexpressing mice each show aspects of behavioral impairment and anatomical pathology reminiscent of that seen in Parkinson's disease highlighting their usefulness. The central hypothesis is that loss of function of ATP13A2 enhances alpha-synuclein toxicity leading to accelerated dopaminergic cell loss and functional impairments in vivo. The hypothesis has been formulated on the basis of preliminary and published studies produced by the applicants' laboratories. The rationale for the proposed research is that once the pathologic mechanisms associated with cellular and behavioral dysfunction are identified, the development of potential therapies can be initiated. Guided by preliminary data this hypothesis will be tested by pursuing two specific aims: 1) Determine the functional effects of the interaction between loss of ATP13A2 and enhanced 1-synuclein protein burden in vivo. 2) To test the hypothesis that loss of function of ATP13A2 combined with overexpression of alpha-synuclein in mice leads to lysosomal dysfunction, increased abnormal accumulation of alpha-synuclein, and an acceleration of nigrostriatal dopamine neuron death in vivo. In the first aim, ATP13A2 null mice generated by the applicants' laboratory and mice that overexpress alpha-synuclein will be crossbred to generate double mutant ATP13A2 null mice that overexpress alpha-synuclein. These mice will be tested for behavioral impairments as they age on tests designed and established in the applicants' laboratories. In aim two, a combination of immunohistochemical techniques, neurochemical analysis, and stereological techniques will be used to measure brain lysosomal proteins, alpha-synuclein, and nigrostriatal pathology at multiple ages. The proposed approach is innovative, because it focuses on the interaction between two genetic loci linked to Parkinsonism in an in vivo environment. The proposed research is significant because it is the first step in a line of research expected to lead to the identification of mechanisms contributing to the development of PD and provide a model to test potential therapeutics targeting these mechanisms. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health because the discovery of how genes associated with inherited forms of Parkinson's disease interact is ultimately expected to enhance understanding of the pathogenic mechanisms associated with this progressive disease and lead to the development of disease- modifying interventions. The proposed research is relevant to the part of the NIH's mission that is directed at developing knowledge that will help reduce the burdens of human disability.