Mechanisms and Therapeutic Role of C-terminus of Cav1.3 L-type Calcium Channel in the Heart

Cav1.3 L型钙通道C末端对心脏的作用机制及治疗作用

• 批准号: 10481142
• 负责人: Mohamed Boutjdir
• 金额: --
• 依托单位: VA NEW YORK HARBOR HLTHCARE/SYS/BROOKLYN
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-10-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10481142
• 关键词: Action Potentials; Adult; Aging; Anterior Descending Coronary Artery; Biochemical; Calcium; Cardiac; Cardiac Myocytes; Cardiac development; Cardiovascular Diseases; Cause of Death; Cell Nucleus; Cell membrane; Cell physiology; ChIP-seq; Coupling; Data; Developed Countries; Development; Echocardiography; Electrophysiology (science); Elements; Enhancers; Environment; FDA approved; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Health; Heart; Heart Atrium; Heart Contractilities; Heart failure; Histology; Ions; Knockout Mice; L-Type Calcium Channels; Laboratories; Left; Left Ventricular Ejection Fraction; Left Ventricular Function; Ligation; Light; Mediating; Messenger RNA; Mus; Muscle Cells; Neonatal; Neurosecretory Systems; Optics; Patients; Peptides; Play; Population; Promoter Regions; Property; Proteins; Public Health; Publishing; Regulation; Reporting; Research; Role; Signal Transduction; Sinoatrial Node; Testing; Therapeutic; Time; Tissues; Ventricular; Veterans; Western Blotting; Work; atrioventricular node; density; design; design and construction; differential expression; fetal; functional restoration; gene therapy; heart function; improved; in vivo; innovation; mouse model; novel; novel therapeutic intervention; patch clamp; promoter; rational design; transcription factor; transcriptome sequencing; translational impact; vector; voltage

In the heart, there are two types of L-type calcium channels, the classical Cav1.2 and the novel less characterized Cav1.3. They both convert cell-membrane depolarization into calcium transients and initiate excitation-contraction coupling. Interestingly, Cav1.3 is expressed in the supraventricular tissue and ventricles of the fetal and neonatal hearts but not in the ventricles of the adult heart. Cav1.3 also has an extended C-terminus. Relevant to this application is that our preliminary data demonstrate that the C-terminus of Cav1.3 is mobile and functions as a transcription auto-enhancer of its own Cav1.3 gene. This unique endogenous property can be leveraged to generate inotropic force necessary to restore cardiac function in the setting of heart failure which is highly prevalent in Veterans. Here we will test, for the first time, the hypothesis that the translocation of the Cav1.3 C-terminus mobile fragment to the nucleus will upregulate Cav1.3 gene expression at specific promoter region(s) and thus provide additional calcium entry into the cardiac myocyte resulting in improved cardiac function in a murine model of heart failure. This hypothesis will be tested in three aims: Aim 1: Investigate the regulation of gene expression by C-terminus of Cav1.3 in a native environment; Aim 2: Determine the mechanisms of Cav1.3 C-terminus regulation of Cav1.3 gene promoter activity; Aim 3: Investigate the potential therapeutic impact of Cav1.3 C-terminus in heart failure. Studies will be carried out by a combination of electrophysiological (patch-clamp and optical mapping), RNA-seq, biochemical, echocardiography and histology, in in-vivo and ex-vivo hearts. The findings from this work will provide a novel mechanism by which Cav1.3 L-type calcium channel acts not only as a conventional ion pore but also as a transcription factor regulating gene expression and cell function via its C-terminus. The ability of the C-terminus of Cav1.3 to upregulate its own gene can be exploited for the development of novel inotropic therapies for heart failure which is prevalent in Veterans.

在心脏中，有两种类型的 L 型钙通道，经典的 Cav1.2 和新颖的 Cav1.3 特征较少。它们都将细胞膜去极化转化为钙 瞬变并启动兴奋-收缩耦合。有趣的是，Cav1.3 的表达形式为 胎儿和新生儿心脏的室上组织和心室，但不包括胎儿和新生儿的心室 成人的心。 Cav1.3 还具有延长的 C 末端。与此应用相关的是我们的 初步数据表明，Cav1.3 的 C 末端是可移动的，并且具有 其自身的 Cav1.3 基因的转录自动增强子。这种独特的内生特性可以 利用杠杆作用产生恢复心脏功能所需的正性肌力 失败在退伍军人中非常普遍。在这里，我们将首次检验假设 Cav1.3 C 末端移动片段易位至细胞核将上调 Cav1.3 基因在特定启动子区域表达，从而提供额外的钙进入 进入心肌细胞，从而改善小鼠心脏模型的心脏功能 失败。该假设将通过三个目标进行检验： 目标 1：研究基因的调控 Cav1.3在天然环境中的C末端表达；目标 2：确定机制 Cav1.3 C末端对Cav1.3基因启动子活性的调节；目标 3：调查 Cav1.3 C 末端对心力衰竭的潜在治疗作用。研究将由 电生理学（膜片钳和光学图谱）、RNA-seq 的组合， 体内和体外心脏的生化、超声心动图和组织学。研究结果来自 这项工作将提供一种新的机制，Cav1.3 L型钙通道不仅可以发挥作用 作为传统的离子孔，也作为调节基因表达和细胞的转录因子 通过其 C 末端发挥作用。 Cav1.3 C末端上调自身基因的能力 可用于开发治疗心力衰竭的新型正性肌力疗法 多见于退伍军人。