Small Molecule Probes for Elucidating LRRK2 Kinase Functions

描述（由申请人提供）：神经退行性疾病，包括阿尔茨海默病、帕金森病、亨廷顿病、肌萎缩侧索硬化症（ALS）和多发性硬化症，折磨着很大一部分人口。许多这些疾病也对治疗干预非常有抵抗力，主要是因为难以确定提供疾病改变作用的药理学上可改变的分子靶标。然而，最近的研究已经在最常见的家族型和一些散发性帕金森病（PD）中发现了富含亮氨酸的重复激酶2基因（LRRK2）的突变。LRRK2是一个由多个结构域组成的大蛋白，包括激酶和GTPase结构域。研究还表明，LRRK2的激酶活性在最常见的pd相关突变G2019S和其他一些突变中升高。此外，激酶活性的增加与神经元毒性的升高有关，这表明LRRK2的功能获得机制。本提案的目的是将从高通量筛选中确定的hit发展成更有用的探针，以阐明LRRK2的作用。本提案的具体目的是进行结构-活性关系（SAR）研究和优化三个不同结构系列的LRRK2激酶抑制剂，对LRRK2激酶抑制剂进行酶学表征，并开发基于功能细胞的实验来确认LRRK2激酶抑制剂的细胞活性。尽管PD患者亚群携带LRRK2突变，但它在散发性和家族性病例中都有发现，良好的探针化合物可能会在了解该蛋白的功能和疾病病理方面取得重大突破。

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.