Regulation of Cav1.2 Trafficking by GJA1-20k and cBIN1

GJA1-20k 和 cBIN1 对 Cav1.2 贩运的监管

基本信息

批准号：
10475207
负责人：
TingTing Hong
金额：
$ 56.14万
依托单位：
UNIVERSITY OF UTAH
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2025-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10475207
关键词：
Actins Affect American Animals Basic Science Biological Calcium Cardiac Cardiac Myocytes Cardiac health Cardiomyopathies Cell Line Cell model Cells Connexin 43 Coupling Cytoskeleton Data Development Disease Epidemic Functional disorder Genetic Goals Heart Heart Diseases Heart failure Homeostasis Human Impairment In Vitro Intercalated disc L-Type Calcium Channels Laboratories Lead Maintenance Membrane Membrane Biology Methods Microtubules Modeling Molecular Movement Mus Muscle Cells Myocardium Outcome Pathologic Pathway interactions Pharmacology Publishing Recycling Regulation Relaxation Reporting Research Resources Ryanodine Receptors Seeds Source Stress Surface Syndrome Testing Therapeutic United States United States National Institutes of Health Ventricular Vesicle base biosignature extracellular extracellular vesicles gene therapy heart function improved in vivo innovation mouse model novel novel diagnostics novel marker novel therapeutic intervention novel therapeutics preservation restoration targeted delivery targeted treatment therapeutic development therapy development tool trafficking translational impact translational potential vesicular release

项目摘要

In normal hearts, the transverse tubules (t-tubules) concentrate L-type calcium channels (LTCCs) to initiate the beat-to-beat intracellular calcium transients which contribute to the regulation of cardiac contraction and relaxation. An altered calcium transient is a key pathophysiological sign of failing heart. However, mechanisms of maintenance of LTCC expression at t-tubule microdomains for optimal calcium-induced-calcium-release (CICR) remain poorly understood. Understanding the dynamic regulation of calcium handling microdomains at t-tubules, and in particular LTCC regulation at the microdomains, is needed to understand the pathophysiology of failing hearts and to identify new pathways and molecules that can be targeted for heart failure therapy development. The overall objective of this MPI application is to further our mechanistic understanding of how LTCC expression at t-tubule cBIN1-microdomains is maintained and why LTCC localization is altered in heart failure. We will explore the central hypothesis that homeostatic LTCC expression at t-tubules is highly dynamic and maintained by both internal delivery and external delivery. We expect that the internal delivery is determined by intracellular actin reservoirs of LTCCs organized at Z-disks by a newly identified actin nucleator GJA1-20k (Aim 1, RMS). We also expect that there is a local extracellular reservoir of cBIN1 vesicles (Aim 2, TTH), which feed t-tubule cBIN1-microdomains from other regions of the heart to modulate LTCC expression at t-tubule surfaces. In heart failure, both sources are depleted yet could be exogenously restored. The resources of a membrane biology lab (TTH) and a trafficking lab focused on heart failure progression (RMS) are combined in this application for the proposed research plan. The rationale that underlies the proposed research is that LTCCs at t-tubule microdomains are dynamically regulated from both inside and out, are reduced in heart failure, and can be restored presenting a novel therapy for heart failure. The proposed research is innovative because it will identify new regulatory mechanisms of remodeled myocardium during heart failure progression, and lead to the establishment of molecules and pathways that can be targeted for therapy development. The proposal has a strong premise because it is based on extensive published and preliminary data from successful in vitro cell-free studies, intact cell line and primary cardiomyocyte studies, and successful genetic and in vivo animal heart failure models. The significance is high because it will lead to development of new therapeutic strategies that will allow preservation and restoration of efficient excitation-contraction coupling in diseased hearts.

在正常心脏中，横向小管（T 型小管）集中 L 型钙通道（LTCC）启动逐次心跳的细胞内钙瞬变，这有助于调节心脏收缩和舒张。钙瞬变的改变是一个关键的病理生理学标志失败的心。然而，T 管微区 LTCC 表达的维持机制最佳钙诱导钙释放（CICR）仍然知之甚少。了解动态 T 管处钙处理微区的调节，特别是 LTCC 的调节需要理解衰竭心脏的病理生理学并识别新的微域可作为心力衰竭治疗开发目标的途径和分子。该 MPI 应用程序的总体目标是进一步加深我们对如何实现这一点的机械理解 t 管 cBIN1 微域的 LTCC 表达得以维持，以及为什么 LTCC 定位发生改变心脏衰竭。我们将探讨中心假设，即 t 管中的稳态 LTCC 表达是高度动态并由内部交付和外部交付维持。我们期望内部递送由 LTCC 的细胞内肌动蛋白储存库决定，该储存库由 Z 盘组织而成新鉴定的肌动蛋白成核剂 GJA1-20k（目标 1，RMS）。我们也希望当地有一个 cBIN1 囊泡的细胞外储库（目标 2，TTH），为 t 管 cBIN1 微结构域提供营养心脏的其他区域调节 T 管表面的 LTCC 表达。在心力衰竭中，两者资源已耗尽，但可以外源恢复。膜生物学实验室 (TTH) 和专注于心力衰竭的贩运实验室的资源进展（RMS）结合在本申请中以用于拟议的研究计划。理由是拟议研究的基础是 T 管微区的 LTCC 受到动态调节从内到外，减少心力衰竭，并且可以通过一种新疗法恢复用于心力衰竭。拟议的研究具有创新性，因为它将确定新的监管机制在心力衰竭进展过程中重塑心肌，并导致分子的建立以及可作为治疗开发目标的途径。该提案有一个强有力的前提因为它是基于成功的体外无细胞研究的大量已发表的初步数据研究、完整细胞系和原代心肌细胞研究以及成功的遗传和体内动物研究心力衰竭模型。意义重大，因为它将导致新治疗方法的开发允许保存和恢复有效的兴奋-收缩耦合的策略患病的心。