Dynamic Interaction Between Cardiac Fibroblasts, Myocytes and the ECM

描述（由申请人提供）：心脏的形成需要几种细胞类型（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）组分的相互作用。这些细胞和非细胞成分的组织对于响应成人的各种生理信号是必要的。心脏成纤维细胞与肌细胞和ECM的相互作用知之甚少，这是拟议研究的主题。细胞成分的特定排列对于化学、机械和电信号的通信至关重要。显示细胞数量、ECM含量和生理参数变化的三种不同模型将用于检查以下假设：在正常和适应性情况下，肌细胞、成纤维细胞和ECM之间的相互作用在调节心脏生长和重塑中至关重要。成纤维细胞和肌细胞之间的相互作用，这是由机械和化学信号调节，是必不可少的心脏的适当形式和功能。解决这一假设的具体目标是：具体目标1。确定压力超负荷肥大、IL-6损失和骨膜蛋白损失对成纤维细胞-肌细胞相互作用的影响。将在体内和体外检查成纤维细胞与肌细胞和ECM的相互作用，以确定细胞数量是否随细胞因子（特别是IL-6）和骨膜蛋白表达的变化而变化。具体目标2。确定机械刺激如何影响肌细胞-成纤维细胞相互作用。使用独特的3-D培养系统，机械信号和细胞因子刺激的作用将用于测量成纤维细胞增殖、凋亡、与肌细胞的相互作用和ECM表达。具体目标3。确定调节成纤维细胞和肌细胞之间相互作用的连接蛋白和ECM受体。这些研究将采用各种细胞和分子方法来检查细胞表征、增殖、周转以及成纤维细胞与肌细胞和ECM在正常新生儿生长、压力超负荷肥大和骨膜蛋白-/-小鼠和IL-6-/-小鼠中改变的心脏重塑期间的相互作用，这些小鼠显示出改变的心脏生理学和表型。此外，这些研究将利用显示体内样肌细胞-成纤维细胞-ECM表型的3-D培养系统。从这些研究中产生的数据将导致心脏成纤维细胞的作用及其与心肌细胞在心脏重塑的调节中的相互作用的重要新信息，以及提供新的治疗靶点来控制心脏重塑的不良影响。 公共卫生相关性：拟定的研究将检查心脏成纤维细胞、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和ECM之间的化学，机械和电信号在正常生长和病理生理条件下。

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.