权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Kidney vascularization: semaphorin-mediated mechanisms.

肾脏血管化：信号蛋白介导的机制。

基本信息

批准号：
7027116
负责人：
Alda Tufro
金额：
$ 28.7万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-03-10 至 2009-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7027116
关键词：
SDS polyacrylamide gel electrophoresis angiogenesis biological signal transduction cell migration confocal scanning microscopy enzyme linked immunosorbent assay genetically modified animals immunocytochemistry kidney kidney circulation laboratory mouse nephrogenesis polymerase chain reaction renal glomerulus tissue /cell culture vascular endothelium western blottings

项目摘要

DESCRIPTION (provided by applicant): The molecular basis of directional migration of endothelial cells and the patterning of the developing vasculature during kidney organogenesis are poorly understood. We showed that VEGF is a chemoattractant for endothelial cells and directs the migration of endothelial cells towards developing nephrons. Other guidance cues are necessarily involved to modulate vascular growth. The nature of these guidance cues is unknown. Two VEGF co-receptors, neuropilins 1 and 2 are also receptors for semaphorins 3A and 3F. Semaphorins are guidance proteins that induce axon chemorepulsion. Sema 3A decreases endothelial cell migration by competing with VEGF for neuropilin binding. We showed that sema 3A and 3F are expressed during renal morphogenesis and localize to renal epithelial cells in a complementary fashion to their receptors located in endothelial cells, suggesting that semaphorins are important for vascular patterning. The objectives of this proposal are to elucidate the mechanisms of endothelial cells directional migration leading to the spatial organization of the developing vasculature and the function of semaphorins 3A and 3F during kidney morphogenesis. We hypothesize that sema 3A and 3F produced by renal epithe!ial cells generate chemorepulsive cues that modulate VEGF's endothelial cell chemoattraction by creating boundaries to endothelial cell migration. The combinatorial possibilities of ligand binding for sema 3 A, sema 3F and VEGF to their shared receptors may result in "paths" for vessel formation. We also hypothesize that the scatter factor-like properties of semaphorins may be responsible, at least in part, for branching morphogenesis of renal epithelia. To test our hypotheses: 1) we will study the mechanims of sema 3A and sema 3F guidance cues for endothelial cell migration by live cell microscopy using co-culture, migration assays, and cell-specific overexpression of sema 3A and 3F in transgenic mice. 2) We will examine the function of semaphorins 3A and 3F in branching morphogenesis and tubulogenesis using tubular epithelial cells, organ cultures and transgenic mice. 3) We will examine the role of FAK and the downstream signaling mechanisms involved in semaphorin-mediated guidance and morphogenetic cues. This proposal should provide novel and important information regarding semaphorin-induced directional migration and advance our knowledge of the molecular mechanisms governing vascular spatial organization. Understanding the molecular basis of guidance cues for cell migration should enable us to generate new strategies for diagnosis and treatment of congenital renal abnormalities and to develop organogenesis in vitro.

描述(申请人提供)：肾脏器官形成过程中内皮细胞定向迁移的分子基础和发育中的血管系统的模式还知之甚少。我们发现，血管内皮生长因子是一种对内皮细胞的趋化因子，并引导内皮细胞向发育中的肾单位迁移。调节血管生长的其他指导信号也是必不可少的。这些指导线索的性质尚不清楚。两个血管内皮生长因子辅助受体，神经毛膜蛋白1和2也是信号素3A和3F的受体。信号素是诱导轴突化学排斥的引导蛋白。SEMA 3A通过与血管内皮细胞生长因子竞争神经粘连蛋白结合来减少内皮细胞迁移。我们发现，SEMA 3A和3F在肾脏形态发生过程中表达，并以一种与其位于内皮细胞的受体互补的方式定位于肾上皮细胞，表明信号素在血管构型中起重要作用。本研究的目的是阐明内皮细胞定向迁移导致发育中血管系统空间组织的机制，以及信号素3A和3F在肾脏形态发生中的作用。我们假设，肾上皮细胞产生的SEMA 3A和3F产生化学斥力信号，通过建立内皮细胞迁移的边界来调节血管内皮细胞的化学吸引力。SEMA-3A、SEMA-3F和血管内皮生长因子的配体与其共同受体结合的可能性可能导致血管形成的“路径”。我们还假设，信号素的散射因子样属性可能至少部分地对肾上皮细胞的分支形态发生起作用。为了验证我们的假设：1)我们将通过活细胞显微镜，通过共培养、迁移分析以及转基因小鼠中SEMA 3A和3F的细胞特异性过表达来研究SEMA 3A和SEMA 3F引导信号对内皮细胞迁移的机制。2)我们将利用肾小管上皮细胞、器官培养和转基因小鼠来研究信号素3A和3F在分支形态发生和小管发生中的作用。3)我们将研究FAK在信号素介导的引导和形态发生线索中的作用及其下游信号机制。这一建议将为信号素诱导的定向迁移提供新的和重要的信息，并促进我们对调控血管空间组织的分子机制的了解。了解细胞迁移引导信号的分子基础将使我们能够产生诊断和治疗先天性肾脏异常的新策略，并在体外开发器官发生。