CELLULAR RECOGNITION AND CARDIAC MORPHOGENESIS

在心脏发育过程中发生的戏剧性细胞变化是 几种形态发生的表达和相互作用的结果 各种因素。在心脏发育的关键时刻，比如循环， 隔膜、小梁形成和瓣膜形成，这些因素发挥着 在决定发展中的形式和功能方面的重要作用 心。心脏发育所必需的基本事件包括 细胞外基质(ECM)成分的表达、排列和 细胞外基质的重塑，细胞外基质与细胞组件的附着，以及 细胞的形成：细胞接触。拟议的调查将集中在 细胞外基质成分与细胞表面特异性受体的相互作用 心脏的分化细胞成分。具体来说，我们 将检测：1)整合素和钙粘附素在不同组织中的表达 心脏发育阶段；2)基底膜的表达 心肌细胞发育过程中的成分及其可能的作用 在心脏的分化中；以及3)生长的作用 整合素、钙粘附素和细胞因子的调节 心脏发育过程中的胶原酶。几种实验方法 将用于分析这些具体目标，包括：a)3维 胶原蛋白凝胶培养检测生长因子/细胞因子对血管内皮细胞生长的影响 细胞外基质成分及其特异性受体和蛋白的表达 金属蛋白水解酶；B)细胞迁移、细胞与聚集体的相互作用 旋转培养中的形成和细胞：细胞外基质黏附试验确定 潜在调节成分的作用；c)全脑微量注射 确定胚胎培养和单个细胞的调控效果 特定发育阶段的组成部分；d)形态和 特异性调控蛋白免疫定位的形态计量学分析 发育关键阶段的成分及其受体；以及 E)分析调节性蛋白的生化和分子表达 胶原凝胶中的成分、胚胎培养与体内培养的比较 发展。这些实验方法将允许分析 与正常心脏相关的形态发生事件的调控 发展，并提供有关 先天性心脏缺陷。

The dramatic cellular changes that take place during heart development are the result of the expression and interaction of several morphogenetic factors. At critical times in heart development, such as looping, septation, trabeculation, and valve formation, these factors play a significant role in determining the form and function of the developing heart. Fundamental events necessary for heart development include the expression of extracellular matrix (ECM) components, arrangement and remodeling of ECM, attachment of the ECM to cellular components, and the formation of cell:cell contacts. The proposed investigations will focus on the interaction between ECM components and specific cell surface receptors of the differentiating cellular components of the heart. Specifically we will examine: 1) the expression of integrins and cadherins at different stages of heart development; 2) the expression of basement membrane components during development by cardiac myocytes and their possible role in differentiation of the heart; and 3) the role of growth factors/cytokines on the regulation of integrins, cadherins and collagenases during cardiac development. Several experimental approaches will be used to analyze these specific aims including: A) 3-dimensional collagen gel cultures to examine the effects of growth factors/cytokines on expression of ECM components, their specific receptors and metalloproteases; B) cell migration, cell-cell interaction with aggregate formation in rotation culture, and cell:ECM adhesion assays to determine the role of potential regulatory components; C) microinjection of whole embryo cultures and individual cells to determine the effects of regulatory components at specific stages of development; D) morphological and morphometric analysis of immunolocalization of specific regulatory components and their receptors during critical stages of development; and E) analysis of the biochemical and molecular expression of regulatory components in collagen gels, embryo culture compared to in vivo development. These experimental approaches will allow for the analysis of the regulation of the morphogenetic events associated with normal heart development and provide essential data on the mechanisms involved in congenital heart defects.