Role of Fibroblasts in Cardiac Remodeling and Regulation of Cardiomyocytes

成纤维细胞在心脏重塑和心肌细胞调节中的作用

• 批准号: 8834587
• 负责人: Celinda Michelle Kofron
• 金额: $ 5.77万
• 依托单位: RHODE ISLAND HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2016-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8834587
• 关键词: Action Potentials; Adult; Affect; Angiotensin II; Area; Arrhythmia; Biochemical; Biomimetics; Calcium; Cardiac; Cardiac Myocytes; Cardiovascular Diseases; Cell Communication; Cell Count; Cells; Cessation of life; Chemicals; Coronary Arteriosclerosis; Coupling; Defect; Deposition; Development; Dyes; Endothelin-1; Event; Experimental Models; Extracellular Matrix; Fibroblasts; Fibrosis; Gap Junctions; Gene Transfer; Generations; Healed; Heart; Heart failure; Hereditary Disease; Histology; Homeostasis; Hypertension; Hypertrophy; Immunohistochemistry; Individual; Infarction; Injury; Laboratories; Lead; Location; Maps; Mechanics; Mediating; Mediator of activation protein; Modeling; Morphology; Muscle; Myocardial; Myocardial Infarction; Myocardial tissue; Myocardium; Myofibroblast; Neonatal; Optics; Outcome; Performance; Physiological; Population; Prevention; Proliferating; Property; Rattus; Regulation; Research; Research Design; Role; Shapes; Signal Pathway; Signal Transduction; Stress; Testing; Therapeutic; Tissues; Ventricular; Work; cardiovascular risk factor; healing; hemodynamics; improved; in vitro Model; in vivo; inhibitor/antagonist; interstitial; mortality; mutant; overexpression; paracrine; pressure; prevent; protein expression; public health relevance; response; response to injury; scaffold; subcutaneous; sudden cardiac death; three dimensional structure; three-dimensional modeling

 DESCRIPTION (provided by applicant): Cardiac fibroblasts (CFs), along with cardiac myocytes (CMs), maintain the three-dimensional structure and electrical, chemical, and biochemical homeostasis of the myocardium. In cardiovascular disease, CF become activated, proliferate, and produce more extracellular matrix (ECM), leading to the development of fibrosis. Fibrosis can be divided in reactive (or interstitial) fibrosis, a common response to excessive myocardial loads that causes excess ECM deposition between muscle bundles, and reparative (or compact) fibrosis, a healing response to maintain structural integrity after CM death in response to injury or infarct. CFs (20% of the volume and 40-60% of the total cardiac cell population) are interwoven in densely packed CMs (75% of tissue volume but less than 50% in cells number) and can influence CMs via paracrine effects, direct cell-cell interactions, and indirect cell-ECM interactions. While regulation of CMs by CFs is known to occur in the myocardium in vivo, the mechanisms and functional significance of CF-to-CM cross talk under physiological and pathophysiological conditions are not well understood. The objective of my proposal is to determine the functional consequences and mechanisms of CF-to-CM regulation using a scaffold-free 3D model developed in my sponsor's lab that intermingles CFs and CMs as in the healthy myocardium. I will generate microtissues with interstitial fibrosis by co-seeding neonatal rat ventricular CMs with CFs that are selectively activated (Aim 1). To that end, I will utilize adenoviral gene transfer to overexpress a constitutively active mutant Gαq, a key mediator of CF activation, or use CFs from rats infused with Ang II for 2 weeks in vivo. In Aim 2, I will develop 3D microtissues with activated CFs in compact configuration that separate CM mimicking compact fibrosis using individual microtissues as building blocks. In both Aims, I will test my central hypothesis is that the number of CFs, the concentration of CFs in a given area (or type of fibrosis: compact or interstitial), and the activation state of CFs influence the morphology and electrical activity in cardiac microtissues. Morphological changes of the microtissues will be characterized with histology and immunohistochemistry. Action potentials and calcium transients will be investigated as key parameters of CM function using optical mapping. Potential mechanisms by which the functional and morphological changes are driven will be investigated using immunohistochemistry, protein expression analysis, dye transfer, and gap junction inhibitors. The proposed study is expected to advance understanding of the impact of CFs on CMs the integrated functional response of cardiac microtissues and may elucidate new avenues for therapeutic strategies to treat and/or prevent structural and electrical remodeling in the diseased heart.

 描述（由适用提供）：心肌细胞（CMS）以及心肌的三维结构以及心肌的电气，化学和生化稳态。在心血管疾病中，CF被激活，增殖并产生更多的细胞外基质（ECM），从而导致纤维化的发展。纤维化可以分为反应性（或间质）纤维化，这是对多余的心肌载荷的共同反应，会导致肌肉束之间的ECM过量沉积，以及恢复性（或紧凑的）纤维化，这是对损伤或梗死反应后CM死亡后保持结构完整性的愈合反应。 CFS（占体积的20％和40-60％的心脏细胞群体）在无填充的CMS（占组织体积的75％，但细胞数量少于50％）中交织在一起，并且可以通过旁分泌效应，直接细胞细胞相互作用和间接的细胞-ECM相互作用来影响CMS。尽管已知在体内心肌中通过CFS对CMS进行调节，但在生理和病理生理条件下，CF-TO-CM交叉讲座的机理和功能意义尚不清楚。我的提案的目的是使用赞助商实验室中开发的无脚手架3D模型来确定CF-TO-CM调节的功能后果和机制，该模型将CFS和CMS与健康的心肌相结合。我将通过共种子产生与间质纤维化的微动物 具有选择性激活的CFS的新生大鼠心室CM（AIM 1）。为此，我将利用腺病毒基因转移来过表达组成型活性突变体GαQ，这是CF激活的关键介体，或在体内使用ANG II感染2周的大鼠的CF。在AIM 2中，我将开发具有紧凑型构型激活CFS的3D微动物，该CM使用单个微动物作为构建块分离CM模仿紧凑型纤维化。在这两个目标中，我都将测试我的中心假设，是CFS的数量，在给定区域中的CFS浓度（或纤维化类型：紧凑或间质），CFS的激活状态影响心脏微动物的形态和电活动。微动物的形态变化将以组织学和免疫组织化学为特征。使用光学映射将研究动作电位和钙瞬变作为CM函数的关键参数。将使用免疫组织化学，蛋白质表达分析，染料转移和间隙连接抑制剂来研究功能和形态变化的潜在机制。预计拟议的研究将提高对CFS对CMS的影响的理解，心脏微动物的综合功能反应，并可能阐明新的途径，以治疗和/或预防疾病心脏中的结构和电气改造的治疗策略。