Alk1 regulation of embryonic angiogenesis

Alk1 调控胚胎血管生成

• 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
• 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

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（由申请方提供）：内皮特异性TGFB I型受体Alk 1的纯合失活导致源于血管畸形的胚胎致死性，杂合失活导致潜在致死性人血管发育不良，遗传性出血性毛细血管扩张2型（HHT 2）。显然，AIK 1在构建和维持脊椎动物血管系统中起着必要的作用;然而，该作用的性质目前尚不清楚。该提议的目的是使用可接近的斑马鱼胚胎，其具有良好描述的、刻板的脊椎动物脉管系统，以定义Alkl活化对内皮细胞功能状态和转录物表达的影响。具体目标1包括设计用于测试以下假设的实验：通过Alk 1的TGFB信号传导是血管生成消退所需的。支持这一目标的研究将包括对含有alk 1突变的紫罗兰色Beautiflude（vbg）突变体的内皮发芽和增殖的时间推移共聚焦分析;以及评估过表达显性阴性和/或组成型活性形式的ALK 1的斑马鱼胚胎中的内皮迁移、增殖、发芽和基底膜形成，alk 5（据报道与Alk 1竞争决定内皮状态的典型TGFB I型受体）和内皮内的tgfB。具体目标2包括旨在检验Alk 1由剪切应力诱导并在血管重塑中起作用的假设的实验。将确定血流对斑马鱼胚胎中的alk 1表达和颅血管重塑的影响，并将评估剪切应力对培养的哺乳动物细胞中的alk 1表达的影响。进一步的实验将确定将机械剪切应力转化为Alk 1诱导的途径的分子组分。具体目标3包括旨在鉴定Alk 1信号传导的下游组分的实验。据报道，在哺乳动物细胞培养中由组成型活性Alk 1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Alk 1调节基因。总之，拟议的实验将确定Alk 1是否在血管生成激活，分辨率和/或重塑中发挥作用，并与下游目标的定义，将促进更好地了解正常血管发育和HHT 2发病机制的分子途径。