RETINOL BINDING PROTEIN AND HEART DEVELOPMENT

视黄醇结合蛋白与心脏发育

• 批准号: 6603771
• 负责人: John W Lough
• 金额: $ 27.38万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6603771
• 关键词: chick embryo; endoderm; gene targeting; heart; histogenesis; laboratory mouse; mammalian embryology; myocardium; retinoid binding proteins; thyroid hormone binding protein; tissue mosaicism

DESCRIPTION (the applicant's description verbatim): This laboratory's objective is to identify support and specification factors that are secreted by early embryonic endoderm cells, which regulate heart development. We have recently determined that endoderm strongly expresses the vitamin A transport proteins transthyretin (TTR) and retinol binding protein (RBP). Mapping sites of TTR and RBP protein and mRNA expression in the embryo has revealed that these factors are associated with the heart forming region in general and with definitive myocardial structures in particular. Because the developing heart is highly sensitive metabolic products of retinol, particularly retinoic acid (RA), it is hypothesized that RBP derived from both endoderm and definitive myocardial cells is necessary to regulate retinol delivery to myocardial structures during their development. Deletion of the RBP gene via homologous recombination will be used to test this hypothesis in a variety of murine embryonic models. (1) The first aim will use targeted ES cells to examine the effect of the RBP-/- mutation during cardiogenesis in embryoid bodies. (2) The second aim will utilize chimeric embryos prepared by combining homozygous-deficient RBP-/- ES cells with morula-stage Rosa26 wild-type embryos that constitutively express b-galactosidase. The exclusion of RBP-/- mutant cells from the heart of embryos whose organs are otherwise chimeric would indicate an autonomous requirement for the RBP gene in heart development. (3) The third aim will directly establish the necessity of the RBP gene for heart development by producing RBP-/- embryos from RBP-/- ES cells using the technique of tetraploid aggregation. Finally, (4) a line of RBP-null mice will be prepared to extend these studies. Results from these experiments will elucidate the dependence of the developing myocardium on carefully regulated levels of vitamin A and its product, retinoic acid (RA). These findings will further contribute to an elucidation of the mechanisms which underlie congenital heart defects as well as the reasons why the adult myocardium is incapable of repair.

描述（申请人的描述逐字描述）：该实验室的目标 是确定早期分泌的支持和规范因素 胚胎内胚细胞，调节心脏发育。我们最近有 确定内胚层强烈表达维生素A转运蛋白 经硫代蛋白（TTR）和视黄醇结合蛋白（RBP）。 TTR和 胚胎中的RBP蛋白和mRNA表达表明这些因素 与一般的心脏形成区域相关 特别是心肌结构。因为发展的心脏很高 视黄醇的敏感代谢产物，尤其是视黄酸（RA），它是 假设RBP源自内胚层和确定的心肌 细胞在调节视黄醇在心肌结构中的递送是必要的 他们的发展。通过同源重组删除RBP基因将 用于在各种鼠类胚胎模型中检验该假设。 （1） 第一个目标将使用靶向ES细胞来检查RBP - / - 的效果。 胚胎体内心脏病发生的突变。 （2）第二个目标 利用通过将纯合缺陷的RBP组合组合制备的嵌合胚胎 - / - ES 具有组成性表达的毛拉阶段ROSA26野生型胚胎的细胞 B-半乳糖苷酶。从胚胎中心排除RBP - / - 突变细胞 否则嵌合的器官将表明自主要求 用于心脏发展中的RBP基因。 （3）第三个目标将直接 通过产生RBP基因来确定RBP基因的必要性 RBP - / - 来自RBP - / - ES细胞的胚胎使用四倍体的技术 聚合。最后，（4）将准备一系列RBP无效的小鼠以延伸 这些研究。这些实验的结果将阐明 在经过精心调节的维生素A及其的心肌发展 产品，视黄酸（RA）。这些发现将进一步有助于 阐明基于先天性心脏缺陷的机制 是成年心肌无法修复的原因。