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Perinuclear Signaling and Cardiac Hypertrophy

核周信号传导和心脏肥大

基本信息

批准号：
10372219
负责人：
Kimberly L Dodge-Kafka
金额：
$ 55.72万
依托单位：
UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
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：
2021-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10372219
关键词：
A kinase anchoring protein Adult Affect American Attenuated B-Lymphocytes Binding Binding Proteins Buffers Calcineurin Calmodulin Cardiac Cardiac Myocytes Catecholamines Cell Nucleus Cells Chronic stress Coupling Cyclic AMP Cyclic AMP-Dependent Protein Kinases Data Dependovirus Disease Gene Expression Genetic Transcription Heart Heart Diseases Heart Hypertrophy Heart failure Hypertrophy In Vitro Individual Infusion procedures Mediating Membrane Modeling Molecular Muscle Muscle Cells Muscle Proteins Norepinephrine Nuclear Nuclear Envelope Pathologic Pathway interactions Patients Pharmacology Phosphotransferases Physiological Prevention Prevention strategy Production Proteins Public Health Publishing Rattus Reagent Receptor Activation Receptor Signaling Recombinants Regulation Sarcoplasmic Reticulum Scaffolding Protein Second Messenger Systems Signal Transduction Small Interfering RNA Specificity Syndrome Testing Therapeutic Ventricular Work beta-adrenergic receptor calcineurin phosphatase cardiovascular disorder prevention cell growth design experimental study fighting gene induction in vivo inhibitor mortality nanobodies novel novel strategies novel therapeutics pressure prevent protein B receptor receptor internalization response scaffold side effect therapeutically effective tool transcription factor

项目摘要

Stimulation of the b-adrenergic receptor (bAR) during the flight-or-fight response increases contractility through protein kinase A (PKA)-stimulated Ca2+ fluxes at the sarcoplasmic reticulum (SR). However, chronic stress on the heart leads to long-term stimulation of the bAR by increased circulating catecholamines, resulting in pathological remodeling due to Ca2+-mediated gene transcription. These divergent responses to bAR activation and Ca2+ signaling suggests that multiples pools of bAR-regulated PKA activity exist in the cardiac myocyte. We suggest that internal bARs at the nuclear envelope activate a PKA-stimulated perinuclear Ca2+ signals that induce pathological gene transcription without affecting cardiac contractility. Therefore, reagents that can block nuclear bAR and attenuate perinuclear Ca2+ transients should prevent disease initiation and/or progression without affecting contractility. Our preliminary data finds that PKA bound to the nuclear envelope located scaffolding protein muscle A-kinase anchoring protein b (mAKAPb) responds to internal bARs to initiate perinuclear Ca2+ transients that stimulate pathological gene transcription. The central hypothesis of this proposal is that targeting mAKAPb signalosomes will modulate nuclear b-AR-mediated PKA and Ca2+ responses that induce pathological disease, without inhibiting, and in fact, maintaining cardiac contractility. Specific Aim 1: Stimulation of a nuclear pool of Ca2+ is required for induction of cardiac hypertrophy. In this Aim, we will buffer the mAKAPb-stimulated perinuclear Ca2+ pool using a specifically localized Ca2+ binging protein in order to determine the importance of this pool for induction of cardiac hypertrophy in adult rat ventricular myoytes. Using adeno-associated virus to deliver the mAKAPb-targeted Ca2+ “buffer” to the cardiac myocytes in vivo, we will determine the effect on pathological remodeling induced by pressure overload and catecholamine infusion. Importantly, the effect of buffering perinuclear Ca2+ on contractility will be investigated. Specific Aim 2: Inhibition of mAKAPb-bound PKA blocks induction of cardiac hypertrophy. This Aim will use tools that selectively modulate only mAKAPb-bound PKA to demonstrate that the associated kinase is both necessary and sufficient for induction of cardiac hypertrophy in vitro and in vivo, while not regulating contractility. Specific Aim 3: A nuclear bAR receptor is responsible for cardiac hypertrophy. Using pharmacological inhibitors, mAKAP-targeted nanobodies that inhibit specifically nuclear b-AR activation, and siRNA against specific b-AR subtypes, we will test the hypothesis that internal, nuclear located bARs are responsible for induction of cardiac hypertrophy. However, modulating these receptors should not affect contractility. Through these Aims, this proposal will define a novel signaling compartment orchestrated by mAKAPb that is required for pathological gene transcription and induction of cardiac disease, but does not affect contractility. Furthermore, completion of this project will reveal how targeting mAKAPb signalosomes can be therapeutically beneficial in the prevention of cardiac remodeling and heart failure.

在飞行或战斗反应期间刺激b-肾上腺素能受体（bAR）通过以下途径增加收缩性：蛋白激酶A（PKA）刺激的肌浆网（SR）的Ca 2+通量。然而，长期的压力，心脏通过增加循环中的儿茶酚胺导致bAR的长期刺激，病理性重塑由于Ca 2+介导的基因转录。这些对bAR激活的不同反应和Ca ~（2+）信号表明，心肌细胞中存在多个bAR调节的PKA活性池。我们这表明核膜内部bAR激活PKA刺激的核周Ca 2+信号，诱导病理性基因转录而不影响心肌收缩力。因此，可以阻断核bAR和减弱核周Ca 2+瞬变可预防疾病的发生和/或进展而不影响收缩性。我们的初步数据发现，PKA结合到核膜，支架蛋白肌肉A激酶锚定蛋白B（mAKAP B）响应于内部bAR启动核周Ca 2+瞬变刺激病理基因转录。这项提议的核心假设是靶向mAKAPb信号体将调节核b-AR介导的PKA和Ca 2+反应，诱导病理性疾病，而不抑制，事实上，维持心脏收缩力。具体目标1：诱导心肌肥大需要刺激细胞核内的钙池。在这个目标中，我们将使用特异性定位的Ca 2+结合蛋白缓冲mAKAPb刺激的核周Ca 2+池，以确定该池对于诱导成年大鼠心室肌细胞的心脏肥大的重要性。使用腺相关病毒将靶向mAKAPb的Ca 2+“缓冲液”输送到体内心肌细胞，将确定对压力超负荷和儿茶酚胺输注诱导的病理性重塑的影响。重要的是，将研究缓冲核周Ca 2+对收缩性的影响。具体目标二：抑制mAKAPb结合的PKA可阻断心脏肥大的诱导。该目标将使用工具，仅选择性调节mAKAPb结合的PKA，以证明相关激酶是必需的，足以在体外和体内诱导心脏肥大，而不调节收缩性。具体目标 3：核bAR受体是心肌肥大的原因。使用药物抑制剂，特异性抑制核b-AR活化的靶向mAKAP的纳米抗体和针对特异性b-AR的siRNA 亚型，我们将测试假设，内部，核定位的bAR是负责诱导心脏肥厚然而，调节这些受体不应影响收缩力。通过这些目标，一项提案将定义一个由mAKAPb协调的新的信号传导区室，基因转录和诱导心脏病，但不影响收缩性。此外，完成该项目将揭示靶向mAKAPb信号体如何在治疗上有益于预防心脏重塑和心力衰竭