Development of small molecule Limk inhibitors for probing ocular diseases

描述（由申请人提供）：Lim激酶（Limk）是丝氨酸/苏氨酸激酶，通过磷酸化和失活肌动蛋白结合蛋白、肌动蛋白解聚因子（ADF）和cofilin来调节微管稳定性和肌动蛋白聚合。Limk异构体Limk1或Limk2的异常表达与多种疾病相关的许多功能障碍有关，如青光眼、眼部炎症、癌症、原发性肺动脉高压、颅内动脉瘤、阿尔茨海默病和威廉姆斯综合征。Lim激酶是Rho激酶（ROCK）的下游效应物。近年来，ROCK抑制剂已被证明具有降低眼压的作用，并且认为ROCK抑制剂的这种作用是通过Limk途径实现的。与具有多种底物的Rho激酶不同，Lim激酶作为信号整合点并将这些信息引导到选定的几种底物，这使得Lim激酶成为药物发现的良好靶点，潜在的副作用要小得多。尽管Limk抑制剂具有吸引人的潜力，但在同行评审的出版物中，还没有报道过小分子抑制剂同时表现出良好的效力、高选择性、良好的溶解度和适当的DMPK特性，用于眼部和/或其他中枢神经系统应用（如良好的眼睛和/或大脑渗透特性）。在这个应用中，我们建议开发基于苯并咪唑支架的新型小分子Limk抑制剂。通过两年内大约100种化合物的合成和评估，我们预计会发现生化IC50值< 20 nM，细胞IC50值< 200 nM，选择性好，溶解性好，并且具有良好的眼睛和/或大脑穿透性能的Limk抑制剂。这些化合物将为研究Limk的生物学功能，以及探索眼部疾病和其他Limk相关的中枢神经系统疾病提供有用的分子工具。

DESCRIPTION (provided by applicant): Lim kinases (Limk) are serine/threonine kinases which regulate microtubule stability and actin polymerization by phosphorylation and inactivation of actin binding proteins, the actin depolymerizing factor (ADF) and cofilin. The abnormal expression of either Limk isoform, Limk1 or Limk2, is implicated in numerous malfunctions that are related to a variety of diseases, such as glaucoma, ocular inflammation, cancer, primary pulmonary hypertension, intracranial aneurysms, Alzheimer's disease, and Williams syndrome. Lim kinases are downstream effectors of Rho kinases (ROCK). ROCK inhibitors have been demonstrated to be effective in reducing intraocular pressure (IOP) in recent years, and it is believed that this effect of ROCK inhibitors is through the Limk pathway. Unlike Rho kinases which have multiple substrates, Lim kinases serve as points of signal integration and channel this information to a select few substrates, which makes Lim kinases good targets for drug discovery with much less potential side effects. Despite the attractive potential of Limk inhibitors, there have been no small molecule inhibitors reported in peer-reviewed publications which showed simultaneously good potency, high selectivity, good solubility and appropriate DMPK properties for ocular and/or other CNS applications (such as good eye and/or brain penetration properties). In this application, we propose to develop novel small molecule Limk inhibitors based on a benzimidazole scaffold. Through the synthesis and evaluation of approximately 100 compounds total in two years, we anticipate discovering Limk inhibitors with biochemical IC50 values of < 20 nM, cell-based IC50 values of < 200 nM, good selectivity, excellent solubility, and with good eye and/or brain penetration properties. These compounds will serve as useful molecular tools to study the biological functions of Limk, and to probe ocular diseases and other Limk related CNS diseases. ) PUBLIC HEALTH RELEVANCE: The relevance of this project to public health is that it will provide useful tools to study ocular diseases and other central nervous system (CNS) diseases. Specifically, this research will discover potent and selective inhibitors of Lim kinase (Limk), which will be used as molecular probes to investigate Limk biology in the development and treatment of ocular diseases (glaucoma and ocular inflammation) and likely other Limk related CNS diseases. Eventually these probes can be used to facilitate the discovery of novel drugs to treat glaucoma and ocular inflammation.