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Project 1: Targeting GRK5 in Cardiac Injury and Repair

项目 1：针对心脏损伤和修复中的 GRK5

基本信息

批准号：
10396998
负责人：
Walter J. Koch
金额：
$ 43.59万
依托单位：
TEMPLE UNIV OF THE COMMONWEALTH
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-05-01 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10396998
关键词：
ADRBK1 gene Animal Model Attenuated Binding Binding Proteins Biological Assay Bone Marrow Calcium Calmodulin Cardiac Cardiac Myocytes Cardiomyopathies Cell Nucleus Cell model Cells Cessation of life Chromatin Clinical DNA DNA Binding DNA sequencing Data Deterioration Development Fibrosis Functional disorder G Protein-Coupled Receptor Signaling G protein coupled receptor kinase G-Protein-Coupled Receptors GRK5 gene Gene Expression Regulation Gene Targeting Genetic Transcription Growth Health Heart Heart Diseases Heart Hypertrophy Heart Injuries Heart failure Histone Deacetylase Human Hypertrophy Infiltration Inflammation Inflammatory Injury Knockout Mice Knowledge Laboratories Link Mediating Membrane Modeling Morphology Mus Muscle Cells Myocardial Myocardial Ischemia Myocardium Nature Nuclear Nuclear Translocation Pathogenesis Pathologic Pathology Pathway interactions Peptides Phenotype Phosphorylation Phosphotransferases Physiological Play Precipitation Regulation Repression Role Signal Transduction Stress Syndrome Testing Therapeutic Transgenic Mice Ventricular Ventricular Remodeling Viral bone cell cytokine desensitization gene therapy global health immunoregulation in vivo injury and repair interest ischemic injury mouse model novel novel therapeutics pressure prevent repair strategy response response to injury translational approach translational potential

项目摘要

Project 1 - SUMMARY The clinical syndrome heart failure (HF) continues to be a major health problem world-wide. It is an end-point after cardiac injury/stress, which is usually preceded by cardiac hypertrophy and adverse ventricular remodeling. Over the last two decades, our laboratory has studied HF development with a focus on the role of G protein- coupled receptor (GPCR) signaling. In particular, we are interested in how GPCR kinases (GRKs) regulate normal and diseased myocardial signaling and function. These kinases canonically regulate GPCRs via phosphorylation causing desensitization and a loss of response. GRK2 and GRK5 are the major GRKs expressed in the heart and both have been found to be up-regulated in failing human myocardium and also in animal models. Recently, we have identified a non-GPCR role for GRK5 in the heart as a pathological facilitator of hypertrophy and the maladaptive transition to HF via its localization and activity in the nucleus of cardiomyocytes. In fact, hypertrophic stress induces nuclear translocation of GRK5 where it can act as a Class II histone deacetylase (HDAC) kinase causing de-repression of hypertrophic gene transcription through MEF2. In addition, GRK5, in an apparent non-catalytic manner, can facilitate nuclear NFAT activity on hypertrophic gene transcription. Of interest, GRK5 has been shown to bind to DNA directly and new preliminary data has identified several gene targets via chromatin precipitation and sequencing (ChIP-Seq). The pathological nature of GRK5, a least in pressure-overload, appears to be primarily through its nuclear localization, which appears dependent on calcium-calmodulin (Ca2+-CaM) binding to a region within the amino-terminus of GRK5 (GRK5nt). What isn’t known is whether GRK5 or its nuclear activity participates in cardiac pathology after ischemic injury and this will be determined in this proposal where we have preliminary data suggesting increased GRK5 in myocytes plays a novel role in post-ischemic HF via regulation and modulation of immune cell infiltration and inflammation. Interestingly, this pathology differs significantly from that of GRK2. We have existing and novel mouse models available to us to determine the role of nuclear GRK5 in HF and whether its pathological mechanisms involve pathways and gene targets that do not require the catalytic activity of GRK5. These models will be employed in this Project to investigate these novels aspects of GRK5 in HF development post-stress and to test our Central Hypothesis that GRK5 plays a critical (patho)-physiological role in the heart’s response to injury and targeting and manipulating its unique cellular localization and/or activity in myocytes is a novel therapeutic repair strategy for the injured heart. Our associated Specific Aims are: [1] to determine the DNA/gene targets of nuclear GRK5 in hypertrophy and determine whether kinase activity is involved in its gene regulation; [2] To determine if a translational approach can be employed therapeutically to limit pathological nuclear GRK5 activity; [3] To determine the mechanistic action of GRK5 in the pathophysiology of myocardial ischemic injury and how this specifically differs from GRK2-mediated injury.

项目1 -摘要临床综合征心力衰竭（HF）仍然是世界范围内的主要健康问题。这是一个终点在心脏损伤/应激之后，其通常在心脏肥大和不利的心室重构之前。在过去的二十年里，我们的实验室研究了HF的发展，重点是G蛋白的作用，偶联受体（GPCR）信号传导。特别是，我们感兴趣的是GPCR激酶（GRKs）如何调节正常和患病的心肌信号传导和功能。这些激酶通过以下途径规范地调节GPCR 磷酸化导致脱敏和反应丧失。GRK 2和GRK 5是主要的GRK 在心脏中表达，并且已经发现这两者在衰竭的人类心肌中上调，并且还在动物模型最近，我们已经确定了GRK 5在心脏中作为病理促进剂的非GPCR作用肥大和适应不良的过渡到HF通过其定位和活动在核心肌细胞事实上，肥大性应激诱导GRK 5的核转位，在那里它可以作为一个类 II组蛋白去乙酰化酶（HDAC）激酶通过MEF 2引起肥大基因转录的去抑制。此外，GRK 5，以一种明显的非催化方式，可以促进肥大细胞核NFAT活性，基因转录令人感兴趣的是，GRK 5已被证明直接与DNA结合，新的初步数据显示，通过染色质沉淀和测序（ChIP-Seq）鉴定了几种基因靶。病理性质 GRK 5，在压力过载中最少，似乎主要是通过其核定位，依赖于钙-钙调蛋白（Ca 2 +-CaM）与GRK 5氨基端内区域（GRK 5 nt）的结合。目前尚不清楚GRK 5或其核活性是否参与缺血性损伤后的心脏病理学这将在本提案中确定，我们有初步数据表明，心肌细胞通过调节和调节免疫细胞浸润在缺血后HF中发挥新的作用，炎症有趣的是，这种病理学与GRK 2的病理学显著不同。我们有现有的和新的小鼠模型可供我们确定核GRK 5在HF中的作用以及其病理学这些机制涉及不需要GRK 5催化活性的途径和基因靶点。这些模型将在本项目中研究GRK 5在HF发展中的这些新方面，为了验证我们的中心假设，即GRK 5在心脏的反应中起着关键的（病理）生理作用，损伤并靶向和操纵其在肌细胞中独特的细胞定位和/或活性是一种新的心脏损伤的治疗修复策略。我们相关的具体目标是：[1]确定DNA/基因核GRK 5在肥大中的靶点，并确定激酶活性是否参与其基因调控; [2]为了确定是否可以在治疗上采用翻译方法来限制病理性核GRK 5 活性; [3]确定GRK 5在心肌缺血性损伤的病理生理学中的机制作用以及这与GRK 2介导的损伤有何不同。