Small Molecule Probes for Elucidating LRRK2 Kinase Functions

描述(申请人提供)：神经退行性疾病，包括阿尔茨海默氏症、帕金森氏症、亨廷顿病、肌萎缩侧索硬化症(ALS)和多发性硬化症，困扰着很大一部分人口。这些疾病中的许多也对治疗干预非常抵抗，主要是因为很难识别提供疾病改变效果的药理上可修改的分子靶点。然而，最近的研究发现，在最常见的家族性帕金森病(PD)和一些散发性帕金森病(PD)中，富含亮氨酸的重复序列蛋白2基因(LRRK2)发生了突变。LRRK2是一个由多个结构域组成的大蛋白，包括激酶和GTP酶结构域。研究还表明，在最常见的PD相关突变G2019S和其他一些突变中，LRRK2的S激酶活性升高。此外，激酶活性的增加与神经元毒性的增加相关，这表明LRRK2的功能获得机制。这项建议的目的是将高通量筛选中鉴定出的HITS发展成更有用的探针，以阐明LRRK2的作用。这项建议的具体目的是对三种不同结构的LRRK2激酶抑制剂进行结构-活性关系(SAR)研究和优化，对LRRK2激酶抑制剂进行酶学表征，并开发基于细胞的功能分析来确认LRRK2激酶抑制剂的细胞活性。尽管PD患者的亚群携带LRRK2突变，但在散发性和家族性病例中都发现了LRRK2突变，良好的探针化合物可能会在了解蛋白质的功能和疾病的病理方面取得重大突破。 公共卫生相关性：富含亮氨酸的重复蛋白激酶2(LRRK2)突变与迟发性帕金森氏症有关。这些突变也被证明增加了该酶的激酶活性。这项建议旨在优化最近在筛选活动中确定的LRRK2‘S酶活性和功能作用工具的LRRK2激酶抑制剂的效力和药学性质。

DESCRIPTION (provided by applicant): Neurodegenerative diseases, including Alzheimer's, Parkinson's, Huntington's diseases, amyotrophic lateral sclerosis (ALS) and multiple sclerosis, afflict a large portion of the population. Many of these conditions also have been very resistant to therapeutic intervention primarily due to difficulties identifying pharmacologically modifiable molecular targets that provide disease altering effects. However, recent studies have identified mutations in the leucine-rich repeat kinase2 gene (LRRK2) in the most common familial forms and some sporadic forms of Parkinson's disease (PD). LRRK2 is a large protein comprised of multiple domains, including kinase and GTPase domains. Studies have also demonstrated that LRRK2's kinase activity is elevated in the most common PD-associated mutation G2019S and some other mutations. Furthermore, the increased kinase activity correlates with elevated neuronal toxicity, suggesting a gain-of-function mechanism of LRRK2. The purpose of this proposal is to develop hits identified from high throughput screening into more useful probes to elucidate the role of LRRK2. The specific aims of this proposal are to conduct structure- activity relationship (SAR) studies and optimization of three distinct structure series of LRRK2 kinase inhibitors, to conduct enzymatic characterization of the LRRK2 kinase inhibitors and to develop functional cell-based assays to confirm cell-based activity of LRRK2 kinase inhibitors. Even though subsets of PD patients carry mutations in LRRK2, it is found in both sporadic and familial cases and good probe compounds could lead to significant breakthroughs in understanding the function of the protein and the pathology of the disease. PUBLIC HEALTH RELEVANCE: Mutations in Leucine-Rich Repeat Kinase 2 (LRRK2) are associated with late-onset Parkinson's disease. These mutations also have been shown to increase the kinase activity of the enzyme. This proposal aims to optimize the potency and pharmaceutical properties of LRRK2 kinase inhibitors recently identified in a screening campaign for tools to explore and define LRRK2's enzymatic activity and functional role.