Computational discovery of SGK1 inhibitors for the treatment of heart disease

描述(申请人提供)：心力衰竭(HF)是一种发病率越来越高的临床综合征，是包括心肌梗死、高血压性心脏病和遗传性心肌病在内的各种心肌病过程的最终共同终点。心衰预后不良，严重的死亡率可归因于进展性室性功能障碍和致死性室性心律失常(VA)。因此，开发新的治疗方法以改善心脏功能障碍和纤维化的发展，以及靶向致死性心律失常，显然是一个尚未得到满足的临床需求。血清和糖皮质激素调节的激酶-1(SGK1)是一种依赖PI3K的激酶，在病理性肥厚和心力衰竭时被激活，但在生理性肥厚中不被激活。我们实验室最近的工作表明，SGK1的激活参与了病理性肥厚、心肌纤维化和心律失常的发生。相反，SGK1的基因抑制减轻了生物机械应激后的心力衰竭和纤维化，减轻了在体心脏缺血-再灌注后的缺血性损伤，但对基础心功能没有影响。在这些数据的基础上，我们认为，药物抑制SGK1也可以减轻不同心脏病理模型中的不利重构，减少心功能障碍、纤维化和心律失常，而不会在基线时产生不良影响。目前还没有SGK1的特异性抑制剂可用。我们现在建议使用一个创新的计算机辅助药物发现(CADD)平台来识别和优化SGK1的小分子抑制剂。在具体目标1中，我们将使用基于结构和配体的小分子文库虚拟筛选来鉴定抑制SGK1活性的“HIT”化合物。这些化合物的活性将使用体外荧光偏振激活法进行评估。重要的是，所有小分子“点击”都经过预先过滤，以获得优化的ADMET(吸附、分布、新陈代谢、过量和毒性)指标，从而消除了可能在后期评估中被分类的化合物/化学类型。在特定的目标2中，我们将进一步确定它们在体外特异性和有效地抑制心肌细胞SGK1的能力的顶级候选药物的特征。使用腺病毒基因转移建立心肌细胞验证模型，在该模型中SGK1或密切相关的激酶(Akt1，ILK)被特异性激活或抑制，候选抑制剂将被测试其特异性和选择性。最后，在特定的目标3中，我们将开始使用野生型小鼠和独特的心脏SGK1激活或抑制的体内小鼠模型来检验已确定的抑制剂的体内有效性和特异性。确定SGK1特异有效的抑制剂不仅为我们研究SGK1的S在疾病发病机制中的作用提供了有用的工具，而且还可以为心力衰竭及其并发症的治疗策略提供一个小分子治疗线索。 公共卫生相关性：心力衰竭是一种日益流行的临床综合征，也是全世界发病率和死亡率的主要原因。因此，有一个明显的未得到满足的临床需求，开发新的疗法，可以改善这一重要的临床条件。我们小组和其他人使用基因工程动物模型进行的研究表明，抑制激酶SGK1可能对心力衰竭及其后遗症有重大好处。尽管目前还没有已知的SGK1的药理抑制剂，但在其他环境下，激酶被认为是很好的药物开发靶点。在这个项目中，我们建议使用一种创新的计算机辅助药物发现方法来识别SGK1的抑制剂。排名靠前的候选药物将以其在分离的心肌细胞和动物心脏中特异性和有效抑制SGK1的能力为特征。识别SGK1的特异性和有效的抑制剂不仅将为正在进行的疾病机制研究提供有用的工具，而且还可以为心力衰竭及其并发症的新治疗方法提供基础。

DESCRIPTION (provided by applicant): Heart failure (HF) is a clinical syndrome of growing prevalence and is the final common endpoint of a variety of cardiomyopathic processes including myocardial infarction, hypertensive heart disease, and inherited cardiomyopathies. HF is associated with a poor prognosis, with significant mortality attributed to both progressive ventricular dysfunction and lethal ventricular arrhythmias (VA). Hence there is a clear unmet clinical need to develop novel therapies that can ameliorate the development of cardiac dysfunction and fibrosis as well as target lethal arrhythmias. Serum- and glucocorticoid-regulated kinase-1 (SGK1) is a PI3-kinase (PI3K)-dependent kinase that is activated in pathological hypertrophy and HF but not in physiological hypertrophy. Recent work from our laboratory suggests that SGK1 activation contributes to pathological hypertrophy, cardiac fibrosis, and arrhythmia. In contrast, genetic inhibition of SGK1 mitigates heart failure and fibrosis after biomechanical stress and reduces ischemic injury after in vivo cardiac ischemia-reperfusion, but has no effect on baseline cardiac function. On the basis of these data, we propose that pharmacological inhibition of SGK1 would also mitigate adverse remodeling in different models of cardiac pathology, reducing cardiac dysfunction, fibrosis and arrhythmia without having an adverse effect at baseline. Currently there are no specific inhibitors of SGK1 available. We now propose to use an innovative computer aided drug discovery (CADD) platform to identify and optimize small molecule inhibitors of SGK1. In Specific Aim 1, we will use structure- and ligand-based virtual screens of small molecule libraries to identify "hit" compounds that inhibit SGK1 activity. The activity of these compounds will be evaluated using an in vitro fluorescence polarization kinase assay. Importantly, all small molecule "hits" are pre-filtered for optimized ADMET (adsorption, distribution, metabolism, excression and toxicity) metrics, which eliminates compounds/chemotypes that are likely to be triaged in late stage evaluation. In Specific Aim 2, we will further characterize the top candidates for their ability to specifically and effectively inhibit SGK1 in vitro in cardiomyocytes. Using adenoviral gene transfer to create cardiomyocyte validation models in which SGK1 or closely related kinases (Akt1, ILK) are specifically activated or inhibited, the candidate inhibitors will be tested for their specificity and selectivity. Finally, in Specific Aim 3, we will begin to examine the in vivo efficacy and specificity of identified inhibitors using both wildtype mice and unique in vivo mouse models of cardiac SGK1 activation or inhibition. The identification of specific and effective inhibitors for SGK1 would not only provide us with useful tools for our ongoing investigation of SGK1's role in disease pathogenesis but could also provide a small molecule therapeutic lead for strategies treating heart failure and its complications. PUBLIC HEALTH RELEVANCE: Heart failure is a clinical syndrome of growing prevalence and a major cause of morbidity and mortality throughout the world. Hence there is a clear unmet clinical need to develop novel therapies that can ameliorate this important clinical condition. Studies from our group and others using genetically engineered animal models have suggested that inhibition of the kinase, SGK1, could have significant benefits in heart failure and its sequelae. Although there are currently no known pharmacological inhibitors of SGK1, kinases have been considered good targets for drug development in other settings. In this project, we propose to use an innovative computer aided drug discovery approach to identify inhibitors of SGK1. Top candidates will be characterized for their ability to specifically and effectively inhibit SGK1 in isolated heart muscle cells and in hearts of animals. The identification of specific and effective inhibitors for SGK1 would not only yield useful tools for ongoing investigation of disease mechanisms but could also provide a foundation for novel therapeutic approaches to heart failure and its complications.