Dynamic Interaction Between Cardiac Fibroblasts, Myocytes and the ECM

描述(申请人提供)：心脏的形成需要几种细胞类型的相互作用，包括肌细胞、成纤维细胞、平滑肌细胞和内皮细胞，以及细胞外基质(ECM)的成分。这些细胞和非细胞成分的组织对于成人对各种生理信号的反应是必要的。心脏成纤维细胞与心肌细胞和细胞外基质的相互作用还知之甚少，这是拟议研究的主要主题。细胞组件的特定排列对化学、机械和电信号的通信至关重要。三种不同的模型显示了细胞数量、细胞外基质含量和生理参数的变化，将被用来检验这一假设，即在正常和适应情况下，心肌细胞、成纤维细胞和细胞外基质之间的相互作用在心脏生长和重塑的调节中至关重要。成纤维细胞和心肌细胞之间的相互作用受机械和化学信号的调节，对于心脏的正常形态和功能是必不可少的。解决这一假说的具体目标是：具体目标1。确定压力超负荷肥大、IL-6丢失和Periostin丢失对成纤维细胞-心肌细胞相互作用的影响。将在体内和体外检测成纤维细胞与心肌细胞和细胞外基质的相互作用，以确定细胞数量是否随着细胞因子(特别是IL-6)和Periostin表达的变化而变化。明确目标2。确定机械刺激如何影响肌细胞-成纤维细胞的相互作用。利用一种独特的三维培养系统，机械信号和细胞因子刺激的作用将被用来测量成纤维细胞的增殖、凋亡、与心肌细胞的相互作用和细胞外基质的表达。特定目的3.确定调节成纤维细胞和心肌细胞之间相互作用的连接蛋白和ECM受体。这些研究将使用各种细胞和分子方法来检测在Periostin-/-小鼠和IL-6-/-小鼠的正常新生儿生长、压力超负荷肥厚和心脏重塑期间成纤维细胞与心肌细胞和ECM的细胞特性、增殖、周转和相互作用，这些小鼠表现出心脏生理和表型的改变。此外，这些研究将利用3D培养系统，显示出体内类似肌细胞-成纤维细胞-细胞外基质的表型。这些研究产生的数据将为心脏成纤维细胞及其与心肌细胞相互作用在心脏重塑调节中的作用提供重要的新信息，并为控制心脏重塑的不利影响提供新的治疗靶点。 公共卫生相关性：拟议的研究将检查心脏成纤维细胞、心肌细胞和细胞外基质之间的动态相互作用。实验方法将用于了解这些细胞类型与ECM之间在正常生长和病理生理条件下的化学、机械和电信号。

DESCRIPTION (provided by applicant): Formation of the heart requires the interaction of several cell types including myocytes, fibroblasts, smooth muscle cells and endothelial cells, as well as the components of the extracellular matrix (ECM). Organization of these cellular and acellular components is necessary to respond to a variety of physiological signals in the adult. The interaction of cardiac fibroblasts with myocytes and the ECM is poorly understood and it is the main theme of the proposed studies. The specific arrangement the cellular components is critical for communication by chemical, mechanical and electrical signals. Three different models that show changes in cell number, ECM content and physiological parameters will be used to examine the hypothesis that interaction between myocytes, fibroblasts and the ECM is critical in the regulation of cardiac growth and remodeling during both normal and adaptive situations. The interaction between fibroblasts and myocytes, which is regulated by mechanical and chemical signals, is essential to the proper form and function of the heart. The specific aims that will address this hypothesis are: Specific Aim 1. Determine the effects of pressure overload hypertrophy, IL-6-loss and periostin-loss on fibroblast-myocyte interactions. The interactions of fibroblasts with myocytes and the ECM will be examined both in vivo and in vitro to determine if cell number varies with changes in the expression of cytokines (specifically IL-6) and periostin. Specific Aim 2. Determine how mechanical stimulation affects myocyte-fibroblast interactions. Using a unique 3-D culture system, the effects of mechanical signaling and cytokine stimulation will be used to measure fibroblast proliferation, apoptosis, interactions with myocytes and ECM expression. Specific Aim 3. Determine the junctional proteins and ECM receptors that regulate the interaction between fibroblasts and myocytes. These investigations will employ a variety of cellular and molecular approaches to examine cell characterization, proliferation, turnover and interaction of fibroblasts with myocytes and the ECM during normal neonatal growth, pressure overload hypertrophy and altered cardiac remodeling in periostin-/- mice and IL-6-/- mice, which display altered cardiac physiology and phenotype. Moreover, these studies will utilize a 3-D culture system that displays an in vivo-like myocyte-fibroblast-ECM phenotype. The data generated from these studies will lead to significant new information on the role of the cardiac fibroblast and its interactions with myocytes in the regulation of cardiac remodeling, as well as providing novel therapeutic targets to control the adverse affects of cardiac remodeling. PUBLIC HEALTH RELEVANCE: The proposed studies will examine the dynamic interaction between cardiac fibroblasts, myocytes and the extracellular matrix. Experimental approaches will be used to understand the chemical, mechanical and electrical signaling between these cell types and the ECM under normal growth and under pathophysiological conditions.