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.

在飞行或打击反应期间刺激B-肾上腺素能受体（BAR）可通过蛋白激酶A（PKA）刺激的Ca2+肌浆网（SR）的通量。但是，慢性应力对心脏通过增加循环的儿茶酚胺而导致棒的长期刺激，从而导致由于Ca2+介导的基因转录引起的病理重塑。这些对棒激活的不同响应 Ca2+信号传导表明，心肌细胞中存在杆调节PKA活性的倍数。我们表明核包膜上的内部条激活了PKA刺激的核周CA2+信号诱导病理基因转录而不影响心脏收缩。因此，可以阻止的试剂核条和衰减核周Ca2+瞬态应防止疾病起步和/或进展不影响收缩力。我们的初步数据发现，PKA绑定到位于核包膜脚手架蛋白肌肉A-激酶锚定蛋白B（MAKAPB）响应内部条以启动刺激病理基因转录的核周Ca2+瞬变。该提议的中心假设是靶向makapb信号体会调节核B-ar介导的PKA和Ca2+响应诱导病理疾病，而无需抑制，实际上是维持心脏收缩的。具体目标1：诱导心脏肥大需要刺激Ca2+的核池。在这个目标中，我们将缓冲MakAPB刺激的核周Ca2+池，使用特定局部的Ca2+ binging蛋白按顺序进行缓冲确定该池对于诱导成年大鼠心室肌的诱导心脏肥大的重要性。使用与腺体相关病毒将Makapb靶向的Ca2+“缓冲液”输送到体内心肌细胞，我们将确定压力过载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阻断心脏肥大的诱导。这个目标将使用工具选择性地调节MakAPB结合的PKA，以证明相关的激酶既是必要的，又在体外和体内诱导心脏肥大的特定目的，而不调节收缩力。 3：核棒受体负责心脏肥大。使用药物抑制剂， MAKAP靶向的纳米构造，这些纳米体抑制特异性核B-AR激活，而siRNA对特定B-ar 亚型，我们将检验以下假设：内部核位置杆负责诱导心脏肥大。但是，调节这些受体不应影响收缩力。通过这些目标，提案将定义一个由Makapb精心策划的新型信号室，这是病理学所必需的基因转录和心脏病的诱导，但不会影响收缩力。此外，完成该项目将揭示靶向makAPB信号体如何对预防有益心脏重塑和心力衰竭。