Targeting of B-AR/GBy signaling in the heart with small molecules

用小分子靶向心脏中的 B-AR/GBy 信号传导

• 批准号: 8235833
• 负责人: Burns C Blaxall
• 金额: $ 38.24万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-05 至 2013-01-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8235833
• 关键词: ADRBK1 gene; Acute; Address; Adenylate Cyclase; Adrenal Glands; Adult; Agonist; Beta-Adrenergic Receptor Kinase 1; Binding; Bioavailable; Cardiac; Cardiac Myocytes; Catecholamines; Chromaffin Cells; Chronic; Data; Disease; Down-Regulation; Event; Feedback; Functional disorder; G-substrate; GTP-Binding Proteins; Goals; Heart; Heart failure; Hypertrophy; In Vitro; Infection; MAPK3 gene; Membrane; Modeling; Morphology; Mus; Operative Surgical Procedures; Pathologic; Pathway interactions; Peptides; Phosphorylation; Plasma; Prevention; Recruitment Activity; Role; Science; Signal Pathway; Signal Transduction; Specificity; Structure; Surgical Models; Therapeutic; Tissues; Transgenic Organisms; Translational Research; desensitization; gallein; in vivo; inhibitor/antagonist; knockout animal; novel; novel therapeutics; outcome forecast; prevent; public health relevance; research study; response; small molecule

DESCRIPTION (provided by applicant): Heart failure (HF) is a debilitating disease with poor prognosis. Excess signaling through cardiac G-protein G?? subunits is an important component of HF pathophysiology. They recruit elevated levels of cytosolic G-protein coupled receptor kinase 2 (GRK2, bARK1) to agonist-stimulated b-ARs in HF, leading to the chronic b-AR desensitization and down-regulation that are hallmarks of HF. Previous data has suggested that inhibiting G?? signaling and its interaction with GRK2 could be of therapeutic value in HF. We recently developed a novel small molecule targeting strategy to selectively inhibit G?? binding interactions, and identified several G?? small molecule inhibitors (Bonacci et al, Science, 2006). In particular, compounds M119 and gallein, essentially identical in both structure and function, were found to block G?? -GRK2 interaction in vitro. Our preliminary data further demonstrate that they reduce GRK2 membrane recruitment, enhanced adenylyl cyclase activity, and increased contractility in isolated adult cardiomyocytes in response to b-AR agonist. In vivo, systemic delivery normalized cardiac function, morphology and GRK2 expression in an acute pharmacologic HF model. Importantly, daily treatment for one month halted the progression of HF and pathologic cardiac remodeling when administered to mice with established HF. Recent data demonstrates that elevated adrenal G?? -GRK2 signaling in HF leads to desensitization of adrenal a2-AR feedback inhibition of adrenal catecholamine release. These data suggest that simultaneous inhibition of both cardiac and adrenal G?? -GRK2 signaling could be of substantial therapeutic benefit in HF. Pathologic cardiac G?? signaling was recently found to interact with and result in novel, sustained ERK1/2 phosphorylation at T188; this sustained phosphorylation event has been directly associated with HF. Finally, G?? also signals to PI3K?, the only G?? - regulated PI3K. Large peptide disruption of either PI3K? activity or of PI3K? interaction with GRK2 and their recruitment to G?? is also known to normalize 2-AR signaling and cardiac function in HF models. We have now identified specific G?? inhibitory compounds that block G?? interaction with GRK2, PI3K?, or both. Our overall hypothesis is that selective small molecule targeting of G?? in the heart and in the adrenal gland is a novel therapeutic paradigm for HF, and that general and selective G?? compounds will enhance our current understanding of pathologic G?? signaling in the heart. To address this hypothesis, we propose the following specific aims: 1) Determine the efficacy and cardiac specificity of small molecule G?? inhibition in surgical models of HF. 2) Determine the adrenal role of small molecule G?? inhibition in HF. 3) Determine the role of G?? interaction with a novel ERK1/2 pathway, GRK2 or PI3K? in pathologic cardiac signaling, hypertrophy and cardiomyocyte contractility. In summary, we have exciting preliminary data identifying selective, bioavailable G?? inhibitory compounds that both prevent HF and halt HF progression. Experiments outlined in this proposal may provide a novel therapeutic strategy for HF. PUBLIC HEALTH RELEVANCE: Heart failure (HF) is a debilitating disease with poor prognosis. This proposal aims to investigate newly identified bioavailable compounds targeting an established HF pathway. Successful completion of experiments outlined in this proposal will enhance our current understanding of an established HF signaling pathway, and may provide a novel therapeutic strategy for HF.

描述（由申请人提供）：心力衰竭（HF）是一种预后不良的衰弱性疾病。通过心脏 G 蛋白 G 发出过量信号？亚基是 HF 病理生理学的重要组成部分。它们将升高水平的胞质 G 蛋白偶联受体激酶 2（GRK2、bARK1）募集到心力衰竭中激动剂刺激的 b-AR 上，导致慢性 b-AR 脱敏和下调，这是心力衰竭的标志。先前的数据表明抑制G??信号传导及其与 GRK2 的相互作用可能对心力衰竭具有治疗价值。我们最近开发了一种新型小分子靶向策略来选择性抑制 G??结合相互作用，并确定了几个G??小分子抑制剂（Bonacci 等人，Science，2006）。特别是，化合物M119和gallein在结构和功能上基本相同，被发现可以阻断G α 。 -GRK2 体外相互作用。我们的初步数据进一步表明，它们减少了 GRK2 膜的募集，增强了腺苷酸环化酶活性，并增加了分离的成体心肌细胞对 b-AR 激动剂的反应的收缩性。在体内，全身给药使急性药理学心力衰竭模型中的心脏功能、形态和 GRK2 表达正常化。重要的是，对患有心力衰竭的小鼠进行为期一个月的每日治疗可阻止心力衰竭和病理性心脏重塑的进展。最近的数据表明，肾上腺G??升高？ HF 中的 GRK2 信号传导导致肾上腺 a2-AR 反馈抑制肾上腺儿茶酚胺释放的脱敏。这些数据表明同时抑制心脏和肾上腺 G?? -GRK2 信号传导可能对心力衰竭具有显着的治疗益处。病理性心脏G??最近发现信号传导与 T188 处的 ERK1/2 磷酸化相互作用并导致新的、持续的磷酸化；这种持续的磷酸化事件与心力衰竭直接相关。最后，G??也向 PI3K? 发出信号，唯一的 G?? - 调节 PI3K。 PI3K 的大肽破坏？活性或 PI3K 的活性？与 GRK2 的相互作用及其招募到 G??还已知 HF 模型中的 2-AR 信号传导和心脏功能正常化。现在我们已经确定了具体的G??阻断 G 的抑制化合物？与 GRK2、PI3K？或两者相互作用。我们的总体假设是选择性小分子靶向 G??在心脏和肾上腺中进行治疗是心力衰竭的一种新的治疗范例，并且一般性和选择性的 G??化合物将增强我们目前对病理性 G 的理解？心里发出信号。为了解决这一假设，我们提出以下具体目标：1）确定小分子 G?? 的功效和心脏特异性。 HF 手术模型中的抑制作用。 2）确定小分子G??的肾上腺作用？ HF 中的抑制作用。 3）确定G??的作用与新的 ERK1/2 通路、GRK2 或 PI3K 相互作用？病理性心脏信号传导、肥大和心肌细胞收缩力。总之，我们有令人兴奋的初步数据来识别选择性的、生物可利用的 G??抑制性化合物可预防心力衰竭并阻止心力衰竭进展。该提案中概述的实验可能为心力衰竭提供一种新的治疗策略。 公共卫生相关性：心力衰竭 (HF) 是一种使人衰弱的疾病，预后不良。该提案旨在研究新发现的针对已建立的 HF 途径的生物可利用化合物。成功完成本提案中概述的实验将增强我们目前对已建立的心力衰竭信号通路的理解，并可能为心力衰竭提供一种新的治疗策略。