Alk1 regulation of embryonic angiogenesis

Alk1 调控胚胎血管生成

基本信息

批准号：
7386750
负责人：
BETH L ROMAN
金额：
$ 35.2万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-04-01 至 2011-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7386750
关键词：
Activin Receptor Address Age of Onset Architecture Basement membrane Blood Vessels Blood flow Cephalic Complex Conflict (Psychology)Cultured Cells Data Development Dominant-Negative Mutation Dysplasia Embryo Embryonic Development Endothelial Cells Endothelium Exhibits Gene Expression Profile Genes Genetic Epistasis Goals Heart Hereditary hemorrhagic telangiectasia Homeostasis Human Laboratories Lesion Ligands Ligature Literature Mammalian Cell Maps Mechanics Mediating Messenger RNA Microarray Analysis Modeling Molecular Mus Mutate Mutation Nature Numbers Outcome Pathogenesis Pathway interactions Patients Pattern Personal Satisfaction Pharmaceutical Preparations Phenotype Physiological Play Protein Overexpression Receptor Activation Receptor Signaling Regulation Research Personnel Resolution Role Sheep Siblings Signal Pathway Signal Transduction TGFB1 gene Techniques Telangiectasis Testing Time Transcript Translating Vascular Diseases Vascular remodeling Viola Zebrafish angiogenesis base cis acting element design experience in vivo insight knock-down malformation migration mutant novel positional cloning programs receptor research study response shear stress stem tool

项目摘要

DESCRIPTION (provided by applicant): Homozygous inactivation of the endothelial-specific TGFB type I receptor, Alk1, results in embryonic lethality stemming from vascular malformations, and heterozygous inactivation results in a potentially lethal human vascular dysplasia, hereditary hemorrhagic telangiectasia type 2 (HHT2). Clearly, AIk1 plays a necessary role in building and maintaining the vertebrate vasculature; however, the nature of that role is currently unclear. The objective of this proposal is to use the accessible zebrafish embryo, which has a well described, stereotypical vertebrate vasculature, to define the effects of Alkl activation on endothelial cell functional state and transcript expression. Specific Aim 1 comprises experiments designed to test the hypothesis that TGFB signaling through Alk1 is required for angiogenic resolution. Studies in support of this Aim will include time lapse confocal analysis of endothelial sprouting and proliferation in violet beauregarde (vbg) mutants, which harbor a mutation in alk1; and assessment of endothelial migration, proliferation, sprouting, and basement membrane formation in zebrafish embryos overexpressing dominant negative and/or constitutively active forms of alk1, alk5 (the canonical TGFB type I receptor that reportedly competes with Alk1 in determining endothelial state), and tgfB within the endothelium. Specific Aim 2 comprises experiments designed to test the hypothesis that Alk1 is induced by shear stress and plays a role in vascular remodeling. The effect of blood flow on alk1 expression and remodeling of cranial vessels in zebrafish embryos will be determined, and the effect of shear stress on Alk1expression in cultured mammalian cells will be assessed. Further experiments will identify molecular components of the pathway that translates mechanical shear stress into Alk1 induction. Specific Aim 3 comprises experiments designed to identify downstream components of Alk1 signaling. Expression levels of genes reportedly regulated by constitutively active Alk1 in mammalian cell culture will be compared in vbg mutants and wild type siblings, and novel alkl-regulated genes will be sought by comparing the endothelial transcriptome in vbg mutants and wild type siblings. Taken together, the proposed experiments will determine whether Alk1 plays a role in angiogenic activation, resolution, and/or remodeling, and, with the definition of downstream targets, will promote a better understanding of the molecular pathways of normal vessel development and HHT2 pathogenesis.

描述（由申请人提供）：内皮特异性 TGFB I 型受体 Alk1 的纯合失活会导致血管畸形引起的胚胎致死，杂合失活会导致潜在致命的人类血管发育不良、遗传性出血性毛细血管扩张症 2 型 (HHT2) 。显然，AIk1 在构建和维持脊椎动物脉管系统方面发挥着必要的作用。然而，该角色的性质目前尚不清楚。该提案的目的是使用易于获得的斑马鱼胚胎（其具有明确描述的典型脊椎动物脉管系统）来定义 Alk1 激活对内皮细胞功能状态和转录本表达的影响。具体目标 1 包括旨在测试以下假设的实验：通过 Alk1 的 TGFB 信号传导是血管生成解决所必需的。支持这一目标的研究将包括对紫罗兰色 beauregarde (vbg) 突变体的内皮萌芽和增殖进行延时共聚焦分析，该突变体在 alk1 中存在突变；以及评估过度表达 alk1、alk5（据报道与 Alk1 竞争决定内皮状态的典型 TGFB I 型受体）和 tgfB 的显性失活和/或组成型活性形式的斑马鱼胚胎中的内皮迁移、增殖、发芽和基底膜形成内皮内。具体目标 2 包括旨在检验 Alk1 由剪切应力诱导并在血管重塑中发挥作用的假设的实验。将确定血流对斑马鱼胚胎中 alk1 表达和颅血管重塑的影响，并评估剪切应力对培养的哺乳动物细胞中 Alk1 表达的影响。进一步的实验将确定将机械剪切应力转化为 Alk1 诱导的途径的分子成分。具体目标 3 包括旨在识别 Alk1 信号传导下游组件的实验。据报道，哺乳动物细胞培养物中由组成型活性 Alk1 调节的基因的表达水平将在 vbg 突变体和野生型同胞中进行比较，并且将通过比较 vbg 突变体和野生型同胞中的内皮转录组来寻找新的 alk1 调节基因。总之，拟议的实验将确定 Alk1 是否在血管生成激活、解析和/或重塑中发挥作用，并且通过下游靶点的定义，将促进更好地了解正常血管发育和 HHT2 发病机制的分子途径。