EXTRACELLULAR MATRIX INTERACTIONS IN CARDIAC MORPHOGENESIS

很大一部分先天性心脏病是在瓣膜和 心脏的膜性隔膜，部分来源于 室内软垫内膜垫的形态发生是 一个复杂的过程，涉及一系列基本的发展事件。这些 包括细胞迁移、增殖和分化。这是目标 以更详细地定义该开发序列 并了解特定基因在这一过程中的作用。主要 重点是细胞外基质的成分。以下 问题将得到解决。l）同源框基因Hox的作用是什么 7、在垫状形态发生的起始阶段？这将通过以下方式解决： 检测反义脱氧寡核苷酸对缓冲垫的影响 形态发生和细胞外基质成分的表达， 心脏外植培养和卵内培养。2)什么细胞外基质分子 是在缓冲层形成时表达的吗这将通过以下方式解决： 免疫组化与一组抗体可在 实验室和原位杂交在一些特别感兴趣的情况下。 3)阻断特定的基因表达对发育有什么影响 细胞外基质成分对垫形态发生的影响？这将是 用封闭抗体（如可用）或反义 脱氧寡核苷酸特别是，我们将重点关注透明质酸及其 结合蛋白（CD-44和PG-M）、胶原II和胶原蛋白的组分。 心脏胶质（1 E12），最近在本研究中发现， 实验室4)其他基因在垫状形态发生中的作用将是 随后，随着它们的特征化，研究它们。5)是什么 垫细胞对组织和细胞外基质的贡献 成熟的瓣膜和隔膜该问题将被 通过原位标记垫后的免疫组织学分析来解决 细胞与复制缺陷，lac-Z标记的逆转录病毒，然后 重新孵育开窗注射的鸡蛋。

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.