EXTRACELLULAR MATRIX INTERACTIONS IN CARDIAC MORPHOGENESIS

很大比例的先天性心脏缺陷见于瓣膜和 心脏的膜性隔膜，部分来源于心脏的 心内膜垫。心内膜垫的形态发生是 复杂的过程，涉及一系列基本的发育事件。这些 包括细胞迁移、增殖和分化。这就是我们的目标 以更详细地定义这一发展顺序 并了解特定基因在这一过程中的作用。少校 重点放在细胞外基质的成分上。以下是 问题将会得到解答。L)同源异型盒基因Hox的作用是什么 7、在坐垫形态发生的启动中？这个问题将通过以下方式解决 检测反义脱氧寡核苷酸对缓冲作用的影响 细胞形态发生及细胞外基质成分表达的研究 心脏外植体培养和卵子培养。2)哪些细胞外基质分子 是在垫子形成过程中表达的吗？这个问题将通过以下方式解决 免疫组织化学中有一组抗体可用于 实验室和通过原位杂交在某些情况下特别感兴趣。 3)阻断特定基因的表达对发育有何影响 细胞外基质成分对坐垫形态发生的影响？这将是 使用封闭抗体(如果有)或反义抗体进行 脱氧寡核苷酸。特别是，我们将重点介绍透明质酸及其 结合蛋白(CD-44和PG-M)、II型胶原和 心脏凝胶(1E12)，它是最近在这个 实验室。4)其他基因在缓冲形态发生中的作用将是 随后进行研究，因为它们变得具有特征。5)什么是 垫状细胞对组织和细胞外基质的贡献 心脏的成熟瓣膜和隔膜？这个问题将是 垫子原位标记后的免疫组织学分析 带有复制缺陷的细胞，Lac-Z标记的逆转录病毒，随后 开窗的、注射的鸡蛋的重新孵化。

A large proportion of congenital heart defects are seen in the valves and membranous septa of the heart, which are in part derived from the endocardial cushions. The morphogenesis of the endocardial cushions is a complex process, involving a sequence of basic developmental events. These include cell migration, proliferation, and differentiation. It is the goal of this project to define this developmental sequence in greater detail and to understand the role of specific genes in the process. The major focus is on components of the extracellular matrix. The following questions will be addressed. l) What is the role of the homeobox gene, Hox 7, in the initiation of cushion morphogenesis? This will be addressed by examining the effects of anti-sense deoxyoligonucleotides on cushion morphogenesis and on the expression of extracellular matrix components in heart explant cultures and in ovo. 2) What extracellular matrix molecules are expressed during cushion formation? This will be addressed by immunohistochemistry with a battery of antibodies available in the laboratory and by in situ hybridization in some cases of special interest. 3) What is the developmental effect of blocking the expression of specific extracellular matrix components on cushion morphogenesis? This will be carried out with blocking antibodies, where available, or anti-sense deoxyoligonucleotides. In particular we will focus on hyaluronan and its binding proteins (CD-44 and PG-M), collagen II, and a component of the cardiac jelly (1E12) which has been identified recently in this laboratory. 4) The role of other genes in cushion morphogenesis will be studied subsequently, as they become characterized. 5) What is the contribution of the cushion cells to the tissues and extracellular matrix of the mature valves and septa of the heart? This question will be addressed by immunohistological analysis after in situ labeling of cushion cells with replication-defective, lac-Z labeled retrovirus, followed by the reincubation of the windowed, injected chicken eggs.