Regulation of Ion Channels at BIN1-induced T-tubule Microdomains

BIN1 诱导的 T 管微区离子通道的调节

基本信息

批准号：
9921467
负责人：
TingTing Hong
金额：
$ 5.63万
依托单位：
CEDARS-SINAI MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2020-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9921467
关键词：
Actins Adrenergic Agents Adult Affect Alternative Splicing American Arrhythmia Biochemical Biological Calcium Cardiac Cardiac Myocytes Cells Chronic Complex Coupling Cytoskeleton Data Development Diffusion Epidemic F-Actin Genetic Transcription Goals Heart Heart Diseases Heart failure Human Image Impairment Infusion procedures Ion Channel Ions Isoproterenol L Forms L-Type Calcium Channels Medical Membrane Membrane Microdomains Methods Mission Modeling Molecular Mus Organ Outcome Pathologic Pathway interactions Physiological Positioning Attribute Predisposition Protein Isoforms Proteins Public Health RNA Splicing Regulation Research Resolution Role Ryanodine Receptors Sarcoplasmic Reticulum Signal Transduction Stress Structure Surface Syndrome Testing Therapeutic Intervention United States United States National Institutes of Health Ventricular Work base extracellular fluorescence imaging heart function human model innovation mouse model new therapeutic target novel strategies preservation receptor receptor coupling recruit

项目摘要

PROJECT SUMMARY/ABSTRACT In ventricular cardiomyocytes, transverse-tubules (T-tubules) concentrate L-type calcium channels (LTCC) which approximate and form dyads with ryanodine receptors (RyR2) at sarcoplasmic reticulum membrane. It is not well understood how the dyads form. The overall objective of this application is to identify the key components of dyad organization in healthy and failing hearts. My central hypothesis is that the membrane deformation protein BIN1 creates microdomains within T- tubule microfolds, organizing LTCC clusters and recruiting RyR2 receptors for proper dyad formation, facilitating synchronized calcium-induced-calcium-release and limiting arrhythmias. Furthermore, BIN1 is known to decrease in acquired heart failure, and heart failure can result when these BIN1-orgnized microdomains are disrupted. The rationale that underlies the proposed research is that BIN1-based impaired regulation of dyad structure and function is a reversible aspect of heart failure progression. The first of three aims is to determine, in physiologically normal cardiomyocytes, whether and how cardiac BIN1 is responsible for organizing LTCC-RyR2 dyads. Building on preliminary data, in adult mouse (with or without Bin1 deletion) and human cardiomyocytes, we will use super-resolution fluorescent imaging to identify LTCC-RyR2 localization at BIN1-induced microdomains, and test the role of actin cytoskeleton in LTCC-RyR2 complex formation and function. The second aim is to determine how BIN1 dependent microdomains are disrupted in heart failure. Building on preliminary data, we will use human and mouse models of heart failure to quantify BIN1 splicing and isoform expression, T- tubule folds, and LTCC-RyR2 complex formation and function, as well as the rescue ability of exogenous BIN1. We will also study whether the mechanism of reduced Bin1 transcription and aberrant splicing in heart failure is due to -adrenergic sympathetic dysregulation. The third aim is to determine whether -adrenergic blockade can rescue BIN1-microdomains and limit arrhythmias and heart failure development. Building on preliminary data, we will investigate whether Bin1 deleted mice develop arrhythmia and heart failure when stressed, which can be rescued by -adrenergic blockade. Our contribution here is expected to be a detailed understanding of how BIN1-induced LTCC- RyR2 microdomains are organized and regulated in both normal and diseased hearts. This contribution is significant because it will identify a new approach to ameliorate heart failure progression by preserving the BIN1 microdomains that are critical to normal heart function. The proposed research is innovative, in our opinion, because it introduces the relatively unknown BIN1 as a determinant of T- tubule microdomains thus helping regulate cardiac dyads and calcium transients.

项目摘要/摘要在心室心肌细胞中，横向管（T管）浓缩L型钙在肌质中与ryanodine受体（RYR2）近似和形成二元组的通道（LTCC）网状膜。二元组是如何形成的。总体目标应用是在健康和失败的心中识别二元组织的关键组成部分。我的中心假设是膜变形蛋白BIN1在T-内部产生微区 Tubele Microfolds，组织LTCC簇和募集RYR2受体以进行适当的二元形成，促进同步钙诱导的 - 钙释放和限制心律不齐。此外，BIN1 已知在获得的心力衰竭中会减少，当这些BIN1被识别时会导致心力衰竭微区域被破坏。拟议的研究是基于BIN1的基本原理二元结构和功能的调节受损是心力衰竭进展的可逆方面。三个目的中的第一个是在身体正常的心肌细胞中确定是否和心脏BIN1如何负责组织LTCC-RYR2二元组。基于初步数据，成人鼠标（有或没有BIN1删除）和人类心肌细胞，我们将使用超分辨率荧光成像以鉴定LTCC-RYR2在BIN1诱导的微区域的定位，并测试该作用 LTCC-RYR2复合物的形成和功能中肌动蛋白细胞骨架的。第二个目的是确定 BIN1依赖性微区域如何破坏心力衰竭。在初步数据的基础上，我们将使用心力衰竭的人和小鼠模型来量化BIN1剪接和同工型表达，T- Tubele折叠和LTCC-RYR2复合形成和功能以及救援能力外源性BIN1。我们还将研究降低BIN1转录和异常的机制心力衰竭的剪接是由于-肾上腺素交感神经失调。第三个目的是确定 -肾上腺封锁是否可以挽救BIN1-微生物域并限制心律不齐和心力衰竭发展。在初步数据的基础上，我们将研究BIN1删除的小鼠是否发展压力时心律失常和心力衰竭，可以通过肾上腺封锁来挽救。预计我们在这里的贡献将是对BIN1诱导的LTCC-的详细理解。 RYR2微区域是在正常和解散心脏中组织和调节的。这个贡献之所以重要，是因为它将确定一种通过保留对正常心脏功能至关重要的BIN1微区。拟议的研究是在我们看来小管微域因此有助于调节心脏二元组和钙瞬变。