Mechanotransduction in Heart Development and Regeneration

心脏发育和再生中的机械传导

基本信息

批准号：
9919380
负责人：
GLENN Lawrence RADICE
金额：
$ 40.25万
依托单位：
RHODE ISLAND HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-12-01 至 2022-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9919380
关键词：
Actins Actomyosin Adhesions Adult Agonist Animal Model Architecture Atomic Force Microscopy Binding Biomechanics Birth Cadherin Domain Cadherins Cancer Biology Cardiac Cardiac Myocytes Cardiac development Cell Proliferation Cell physiology Cell-Cell Adhesion Cells Complex Couples Cytoskeleton Deposition Development Down-Regulation Elasticity Extracellular Matrix Extracellular Matrix Proteins Fibronectins Focal Adhesions Heart Heart Injuries Heart failure Human ITGA5 gene Injury Integrins Intercalated disc Knock-out Laboratories Lead Life Mammalian Cell Mechanics Mediating Molecular Muscle Muscle Cells Myocardial Infarction N-Cadherin Natural regeneration Neonatal Nuclear Nuclear Translocation Pathologic Pathway interactions Patients Phosphotransferases Physiological Play Role Signal Transduction System Testing Tissues Transcription Coactivator Work alpha catenin beta catenin blood pump cardiac regeneration cardiogenesis extracellular genetic manipulation heart cell heart function improved improved functioning in vivo inhibitor/antagonist injury and repair insight loss of function mechanical force mechanical load mechanical properties mechanotransduction mouse model novel novel therapeutic intervention polyacrylamide hydrogels postnatal preclinical study receptor regenerative response rho tumor

项目摘要

Mechanical forces play a critical role in regulating cellular function. Cells sense and transduce mechanical signals through cell-cell adhesions and cell-extracellular matrix (ECM) adhesions. Shortly after birth, muscle cells of the mammalian heart lose their ability to divide. Thus, they are unable to effectively replace dying cells in the injured heart. Loss of regenerative potential within the first week of postnatal life coincides with downregulation of the ECM protein fibronectin and its receptor alpha5 integrin, while the N-cadherin/catenin adhesion complex re-distributes to the bipolar ends of the myocyte, creating a specialized cell-cell contact called the intercalated disc (ICD). N-cadherin junctions are stabilized at the ICD by the dynamic binding of the intracellular cadherin domain to the actin cytoskeleton via beta- and alpha-catenins. In recent work our laboratory demonstrated that the simultaneous depletion of both alpha-catenins (aE-/aT-catenin double knockout (DKO)) in the heart resulted in aberrant formation of ICDs and sustained myocyte proliferation beyond the first week of life. Importantly, our preclinical studies showed that temporal inactivation of alpha-catenins in adult hearts following myocardial infarction increases Yap activity, cardiomyocyte proliferation, and improves cardiac function. Yap has been identified as a nuclear relay of mechanical signals, but the molecular mechanisms that lead to Yap activation are poorly understood. We hypothesize that alpha-catenin-regulated cytoskeleton organization couples signals from N-cadherin to integrin in an integrated mechanochemical signaling system to ultimately control cardiomyocyte proliferation. It is proposed that this novel proliferative signal requires Rho-driven changes in cytoskeletal tension, and increased focal adhesion signaling. The following interrelated aims are proposed: (1) To determine the molecular mechanisms by which alpha-catenin regulates tension-driven cardiomyocyte proliferation. (2) To determine whether alpha5 integrin and fibronectin matrix assembly are required to transduce the proliferative signal in alpha-catenin-deficient cardiomyocytes. (3) To determine whether actomyosin-mediated tension via ROCK activation is sufficient to induce ECM assembly, tissue stiffening, and proliferation in the heart. This project will lead to an integrated molecular understanding of how cardiomyocytes coordinate signals from cadherins, integrins, and cytoskeletal network into a proliferative response, and may suggest new therapeutic strategies to stimulate cardiac regeneration in heart failure patients.

机械力在调节细胞功能中起着至关重要的作用。细胞感知和转导通过细胞-细胞粘附和细胞-细胞外基质（ECM）粘附的机械信号。出生后不久，哺乳动物心脏的肌肉细胞就失去了分裂的能力。因此，他们是无法有效替代受损心脏中垂死的细胞。体内再生潜力丧失产后第一周恰逢 ECM 蛋白纤连蛋白及其相关蛋白的下调受体α5整合素，而N-钙粘蛋白/连环蛋白粘附复合物重新分布到双极肌细胞末端，形成一种特殊的细胞与细胞接触，称为闰盘（ICD）。 N-钙粘蛋白连接通过细胞内钙粘蛋白的动态结合而稳定在 ICD 处通过β-和α-连环蛋白将结构域连接到肌动蛋白细胞骨架。在我们实验室最近的工作中证明同时耗尽两种 α-连环蛋白（aE-/aT-连环蛋白双心脏基因敲除（DKO））导致 ICD 的异常形成和持续的心肌细胞增殖超过生命第一周。重要的是，我们的临床前研究表明，时间心肌梗塞后成人心脏中 α-连环蛋白的失活会增加 Yap 活性，心肌细胞增殖，改善心脏功能。 Yap已被确定为核机械信号的传递，但导致 Yap 激活的分子机制很差明白了。我们假设 α-连环蛋白调节的细胞骨架组织耦合信号在集成的机械化学信号系统中从 N-钙粘蛋白到整合素，最终控制心肌细胞增殖。有人提出这种新颖的增殖信号需要 Rho 驱动细胞骨架张力的变化和粘着斑信号传导的增加。以下是相互关联的提出的目标是：（1）确定α-连环蛋白调节的分子机制张力驱动的心肌细胞增殖。 (2) 确定α5整合素和纤连蛋白是否需要矩阵组装来转导α-连环蛋白缺陷的增殖信号心肌细胞。 (3) 确定肌动球蛋白通过 ROCK 激活介导的张力是否有效足以诱导 ECM 组装、组织硬化和心脏增殖。该项目将导致对心肌细胞如何协调信号的综合分子理解钙粘蛋白、整合素和细胞骨架网络参与增殖反应，并可能提示新的刺激心力衰竭患者心脏再生的治疗策略。