Computational discovery of SGK1 inhibitors for the treatment of heart disease

描述（由申请人提供）：心力衰竭（HF）是一种日益流行的临床综合征，是各种心肌病过程（包括心肌梗死、高血压性心脏病和遗传性心肌病）的最终共同终点。HF与不良预后相关，显著的死亡率归因于进行性心室功能障碍和致死性室性心律失常（VA）。因此，有一个明确的未满足的临床需要，开发新的疗法，可以改善心脏功能障碍和纤维化的发展，以及目标致命的心律失常。 血清和糖皮质激素调节激酶-1（SGK 1）是一种PI 3激酶（PI 3 K）依赖性激酶，在病理性肥大和HF中被激活，但在生理性肥大中不被激活。我们实验室最近的工作表明，SGK 1激活有助于病理性肥大，心脏纤维化和心律失常。相比之下，SGK 1的基因抑制减轻了生物力学应激后的心力衰竭和纤维化，并减少了体内心脏缺血-再灌注后的缺血性损伤，但对基线心脏功能没有影响。基于这些数据，我们提出SGK 1的药理学抑制也会减轻不同心脏病理模型中的不良重塑，减少心功能不全、纤维化和心律失常，而在基线时没有不良影响。目前还没有SGK 1的特异性抑制剂。 我们现在建议使用创新的计算机辅助药物发现（CADD）平台来识别和优化SGK 1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库虚拟筛选来识别抑制SGK 1活性的“命中”化合物。这些化合物的活性将使用体外荧光偏振激酶测定法进行评价。重要的是，所有小分子“命中”都经过预过滤以优化ADMET（吸附、分布、代谢、过量和毒性）指标，这消除了可能在后期评估中被分类的化合物/化学型。在具体目标2中，我们将进一步表征其在心肌细胞中特异性和有效抑制SGK 1的能力。使用腺病毒基因转移创建心肌细胞验证模型，其中SGK 1或密切相关的激酶（Akt 1，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，在具体目标3中，我们将开始使用野生型小鼠和心脏SGK 1激活或抑制的独特体内小鼠模型来检查所鉴定的抑制剂的体内功效和特异性。 SGK 1特异性和有效抑制剂的鉴定不仅为我们正在进行的SGK 1在疾病发病机制中的作用的研究提供了有用的工具，而且还可以为治疗心力衰竭及其并发症的策略提供小分子治疗线索。 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，有一个明确的未满足的临床需要，开发新的疗法，可以改善这一重要的临床条件。我们小组和其他使用基因工程动物模型的研究表明，抑制激酶SGK 1可能对心力衰竭及其后遗症有显着的益处。虽然目前没有已知的SGK 1药理学抑制剂，但激酶已被认为是其他环境中药物开发的良好靶点。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SGK 1的抑制剂。最佳候选物将表征其在分离的心肌细胞和动物心脏中特异性和有效抑制SGK 1的能力。SGK 1特异性和有效抑制剂的鉴定不仅可以为正在进行的疾病机制研究提供有用的工具，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.