A Role of PKG1a and Inhibitors of cGMP Phosphodiesterase in Post MI VT in Mouse Models for Type II Diabetes and Metabolic Syndrome

PKG1a 和 cGMP 磷酸二酯酶抑制剂在 II 型糖尿病和代谢综合征小鼠模型 MI 后 VT 中的作用

• 批准号: 10443778
• 负责人: Jonas Bernard Galper
• 金额: $ 67.43万
• 依托单位: TUFTS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10443778
• 关键词: Action Potentials; Acute myocardial infarction; Arrhythmia; Attenuated; Autonomic Dysfunction; Carbachol; Cardiac Myocytes; Cardiovascular Diseases; Cardiovascular system; Cause of Death; Cells; Coronary artery; Cyclic AMP-Dependent Protein Kinases; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Cytosol; Dangerousness; Data; Development; Diabetes Mellitus; Diastole; Diet; Disinhibition; EFRAC; Echocardiography; Electrocardiogram; Epidemic; Fatty acid glycerol esters; Functional disorder; Genetic; Guanylate Cyclase; Heart; Heart Arrest; Heart failure; Homeostasis; Human; Hyperactivity; Insulin; Insulin Resistance; Knockout Mice; Knowledge; Leucine Zippers; Life; Ligation; Measurement; Metabolic syndrome; Modeling; Molecular; Mus; Muscarinic Agonists; Muscle Cells; Mutant Strains Mice; Myocardial; Myocardial Infarction; Natriuretic Peptides; Non-Insulin-Dependent Diabetes Mellitus; Pathogenesis; Patients; Persons; Pharmacology; Phosphodiesterase Inhibitors; Phosphorylation; Phosphotransferases; Physiological; Placebos; Play; Population; Predisposition; Prevention strategy; Protein Kinase; Proteins; Protocols documentation; Publishing; Regulation; Relaxation; Role; Signal Transduction; Signaling Molecule; Sucrose; Sudden Death; Surface; Technology; Testing; Ventricular; Ventricular Arrhythmia; Ventricular Tachycardia; Western Blotting; base; cGMP Phosphodiesterase Inhibitor; cGMP-dependent protein kinase I; cGMP-dependent protein kinase Ibeta; db/db mouse; diabetic; diabetic patient; experimental study; glycogen synthase kinase 3 beta inhibitor; heart rhythm; high risk; in vivo; inhibitor; mortality; mouse model; mutant; mutant mouse model; novel; novel therapeutic intervention; phosphodiesterase V; preservation; prevent; response; reuptake; sildenafil; sudden cardiac death; tau Proteins; uptake

Project Summary The current application proposes to investigate the novel mechanisms through which cGMP and the cGMP- dependent protein kinase I (PKGI) maintain Ca homeostasis and oppose ventricular tachycardia (VT) in the diabetic heart in the setting of acute MI. Diabetes mellitus (DM) is associated with an increase in sudden cardiac death (SCD), but the molecular and cellular mechanisms of arrhythmogenesis in DM remain incompletely understood. T-Wave alternans (TWA) is a rate dependent beat-to-beat fluctuation on the surface EKG that has been associated with life threatening ventricular arrhythmias. T-wave alternans has been described in patients with Type II DM, and hyperactivity of GSK3β has been implicated in secondary effects of DMII, but little is known regarding the mechanism of alternans and its specific role in the pathogenesis of VT in patients, or in mouse models for Type II DM. Inducibility of VT in response to programmed ventricular stimulation has been used to identify patients whose hearts are predisposed to the development of VT. Preliminary data in the current application identify significant inducibility of VT and of TWA in two separate models: the Db/Db mouse model of DMII, and in the High Fat High Sucrose (HFHS) fed mouse model of insulin insensitivity. More importantly, we have demonstrated that these mice develop severe spontaneous arrhythmias following myocardial infarction (MI). We have observed that the intracellular signaling molecule cGMP is decreased in both of these above models. Further, genetic disruption of the primary cardiovascular cGMP effector, Protein Kinase G Iα (PKGIα) leads to T-wave alternans and highly inducible VT, providing direct evidence that this kinase plays a role in the pathogenesis of VT in vivo. Rescue experiments demonstrate that augmentation of cGMP with the cGMP- selective phosphodiesterase 5 inhibitor sildenafil abolishes VT and TWA in the Db/Db and HFHS mice, while the GSK3β inhibitor TWS-119 attenuates VT. Based on these and published data implicating GSK3β as a PKG1α substrate, the current application proposes to test the hypothesis that PKGIα opposes both inducible and spontaneous post MI VT in the diabetic heart through the regulation of GSK3β activity. We propose 3 Specific Aims: 1) Determine the anti-arrhythmic effects of PKGI augmentation in the DMII heart by PDE inhibitors and Guanylate cyclase activators; 2) Determine the physiologic mechanisms by which PKGIα dysfunction predisposes to inducible and post MI VT and alternans via an effect on Ca homeostasis; 3) Determine the downstream signaling mechanisms through which disruption of cGMP-PKG signaling promotes VT in the DMII heart. The data generated from these studies will determine the role of PKGIα signaling in the regulation of VT in the DM II heart and has the potential to identify pharmacologic modulation of PKGI as a novel anti-arrhythmic strategy in patients with DM.

项目摘要 当前的应用程序提出了研究CGMP和CGMP-的新机制 依赖性蛋白激酶I（PKGI）保持Ca稳态，并反对心室心动过速（VT） 急性MI的糖尿病心脏。糖尿病（DM）与心脏突然增加有关 死亡（SCD），但是DM中心律失常发生的分子和细胞机制不完全 理解齿。 T波替代品（TWA）是表面心电图上的率依赖于速率的beat-beat波动 我们与威胁性心室心律失常的生命有关。患者已经描述了T波替代品 在II型DM和GSK3β的多动症中，DMII的继发作用已暗示，但鲜为人知 关于交替机理及其在患者VT发病机理中的特定作用，或者在小鼠中 II型DM的模型。 VT响应程序性心室刺激的诱导性已被用来 确定其心脏易于发育的患者。当前的初步数据 应用在两个单独的模型中确定VT和TWA的显着诱导性：DB/DB小鼠模型的模型 DMII，以及在高脂肪高蔗糖（HFHS）中喂养的小鼠胰岛素不敏化的模型。更重要的是，我们 已经证明这些小鼠在心肌梗塞后会出现严重的赞助心律失常 （Mi）。我们已经观察到细胞内信号传导分子CGMP在上述两者中都降低了 型号。此外，主要心血管CGMP效应子蛋白激酶GIα（PKGIα）的遗传破坏 导致T型替代品和高度诱导的VT，提供了直接的证据，表明该激酶在 VT在体内的发病机理。救援实验表明，使用CGMP增强CGMP 选择性磷酸二酯酶5抑制剂Sildenafil在DB/DB和HFHS小鼠中废除VT和TWA，而TWA则取消 GSK3β抑制剂TWS-119减弱VT。基于这些和已发布的数据隐式GSK3β作为PKG1α 底物，当前的申请提案，以检验PKGIα相反的诱导性和 通过调节GSK3β活性，在糖尿病心脏中赞助的MI VT。我们提出了3个特定的 目的：1）确定PDE抑制剂和DMII心脏中PKGI增强的抗心律失常作用 鸟苷酸环化酶激活剂； 2）确定PKGIα功能障碍的生理机制 通过对CA稳态的影响，易于诱导和诱导后的Mi VT和替代品； 3）确定 下游信号传导机制通过CGMP-PKG信号的破坏促进了DMII中的VT 心。这些研究产生的数据将确定PKGIα信号在VT调节中的作用 在DM II心脏中，有可能识别PKGI的药理调制为一种新型的抗心律失常 DM患者的策略。