Perinuclear Signaling and Cardiac Hypertrophy

核周信号传导和心脏肥大

基本信息

批准号：
10593965
负责人：
Kimberly L Dodge-Kafka
金额：
$ 54.57万
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/10593965
关键词：
A kinase anchoring protein Adrenergic Receptor Adult Affect American Attenuated Binding Binding Proteins Buffers Calcineurin Calmodulin Cardiac Cardiac Myocytes Cardiovascular Diseases Catecholamines Cell Nucleus Cells Chronic stress Coupling Cyclic AMP Cyclic AMP-Dependent Protein Kinases Data Dedications 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 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 Induction Signal Transduction Small Interfering RNA Specificity Syndrome Testing Therapeutic Ventricular Work beta-adrenergic receptor calcineurin phosphatase cell growth design experimental study fighting gene induction in vivo inhibitor mortality nanobodies novel novel strategies novel therapeutics nuclear factors of activated T-cells pharmacologic 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.

在逃跑或战斗反应期间刺激 β 肾上腺素能受体 (bAR) 可通过以下方式增加收缩性：蛋白激酶 A (PKA) 刺激肌浆网 (SR) 的 Ca2+ 通量，但慢性应激会影响肌浆网 (SR)。心脏通过增加循环儿茶酚胺来长期刺激 bAR，从而导致 Ca2+ 介导的基因转录引起的病理重塑。这些对 bAR 激活的不同反应。 Ca2+ 信号传导表明心肌细胞中存在多个 bAR 调节的 PKA 活性池。表明核膜上的内部 bAR 激活 PKA 刺激的核周 Ca2+ 信号，诱导病理基因转录而不影响心肌收缩力因此，可以阻断的试剂。核 bAR 和减弱核周 Ca2+ 瞬变应能预防疾病的发生和/或进展我们的初步数据发现 PKA 与核结合。支架蛋白肌肉 A 激酶锚定蛋白 b (mAKAPb) 响应内部 bAR 启动刺激病理基因转录的核周 Ca2+ 瞬变该提议的中心假设。靶向 mAKAPb 信号体将调节核 b-AR 介导的 PKA 和 Ca2+ 反应诱发病理疾病，而不抑制，事实上，维持心肌收缩力具体目标 1：诱导心脏肥大需要刺激细胞核内的 Ca2+ 池。使用特定定位的 Ca2+ 结合蛋白按顺序缓冲 mAKAPb 刺激的核周 Ca2+ 库确定该库对于诱导成年大鼠心室肌细胞心肌肥厚的重要性。使用腺相关病毒将 mAKAPb 靶向的 Ca2+“缓冲液”递送至体内心肌细胞，我们将确定对压力超负荷和儿茶酚胺输注引起的病理重塑的影响。重要的是，将研究缓冲核周 Ca2+ 对收缩性的影响。具体目标 2：抑制 mAKAPb 结合的 PKA 可阻止心脏肥大的诱导。仅选择性调节 mAKAPb 结合的 PKA 以证明相关激酶既是必需的，也是足以在体外和体内诱导心脏肥大，同时不调节收缩力。 3：核 bAR 受体导致心脏肥大，使用药物抑制剂。特异性抑制核 b-AR 激活的 mAKAP 靶向纳米抗体，以及针对特异性 b-AR 的 siRNA 亚型，我们将检验以下假设：位于核内的 bAR 负责诱导心脏然而，调节这些受体不应影响收缩力。该提案将定义一种由 mAKAPb 精心策划的新型信号室，这是病理学所需的基因转录并诱发心脏病，但不影响收缩力的完成。该项目将揭示靶向 mAKAPb 信号体如何在预防中发挥治疗作用心脏重塑和心力衰竭。