Molecular Mechanisms of MGP; Role in AVMs

MGP的分子机制；

• 批准号: 9915958
• 负责人: Kristina I Bostrom
• 金额: $ 39万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-24 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9915958
• 关键词: ACVRL1 gene; Address; Antibodies; Arteries; Arteriovenous malformation; BMP4; Behavior; Binding; Blood; Blood Vessels; Blood capillaries; Bone Morphogenetic Proteins; Caliber; Cardiac Output; Cell Differentiation process; Cells; Clinical; Crossbreeding; Data; Development; Differentiation Antigens; Differentiation Inhibitor; Disease; Endothelial Cells; Endothelium; Expression Profiling; Feedback; Gene Deletion; Gene Expression; Gene Proteins; Generations; Goals; Growth; Heart; Heart Diseases; Heart failure; Hemorrhage; Hereditary hemorrhagic telangiectasia; Immunoblotting; Impairment; In Vitro; Knock-in Mouse; Lead; Ligands; Link; Liver; Location; Lung; Mediating; Modeling; Molecular; Morphogenesis; Mouse Protein; Mus; Mutation; Organ; Participant; Pattern; Penetrance; Periodicity; Phenotype; Play; Point Mutation; Proline; Protein Deficiency; Protein Inhibition; Proteins; Public Health; Regulation; Retina; Role; Shapes; Signal Transduction; Stroke; System; Techniques; Thinness; Vascular System; Veins; Wild Type Mouse; Work; activin receptor-like kinase 1; bone morphogenetic protein 9; density; design; in vivo; inhibitor/antagonist; malformation; matrix Gla protein; mouse model; notch protein; novel; preference; protein expression; protein function; receptor; response; small hairpin RNA; targeted treatment; therapy design; time use; tissue regeneration; treatment strategy

PROJECT SUMMARY: The vascular system consists of elaborate networks that develop in combination with close regulation of endothelial cells (ECs). An understanding of such regulation is essential for the development of new treatment strategies aimed at vascular malformations, such as arteriovenous malformations (AVMs) and hereditary hemorrhagic telangiectasia (HHT), caused by mutations in activin receptor-like kinase 1 (ALK1). We previously showed that gene deletion in mice of matrix Gla protein (MGP), an inhibitor of bone morphogenetic proteins (BMPs), causes AVMs in multiple organs similar to HHT. We showed that BMP9/ALK1 signaling induces MGP expression in ECs, where MGP plays an important role in differentiation. BMP9/ALK1 signaling also induces Crossveinless-2 (CV2) with a different induction delay, thereby creating two negative feedback loops. Together, MGP and CV2 regulate BMP9 signaling by a previously unknown mechanism. In cultured ECs, we found oscillations of MGP and CV2 expression that temporally coordinated transition to EC stalk cell phenotype in ECs. This also caused markers of stalk cells to oscillate, whereas tip cell markers were suppressed. Deletion of Mgp abolished the oscillatory behavior. In vivo, MGP and CV2 were seen as “shaping waves” or stripes in the growing retina, and lack of MGP perturbed the vascular networks. Our hypothesis is that MGP and CV2 are regulators of BMP9 signaling and vascular morphogenesis through generation of oscillations or waves of expression. In Aim 1, we will characterize how MGP and CV2 orchestrate EC differentiation in response to BMP9 using oscillations of gene expression. We will relate BMP9-induced stalk cell phenotype to the oscillations, and explore expression profiles of ECs capable of this behavior. We will disrupt the system by deleting the Mgp gene in vitro using established techniques of shRNA, and determine the effect on the waves of inhibitors and stalk cell markers. We will also investigate whether waves of MGP and CV2 can be detected in normal vasculature, with focus on the retina. In Aim 2, we will obtain key information about the role of MGP in retinal vascular networks and AVMs by deleting Mgp, impairing MGP protein function, and modulating the cellular origin. We will modulate potential targets for AVM treatments using the Mgp-/- mice as an AVM model. We will start with modulation of CV2 and use approaches that include crossbreeding with genetically altered mice and transmammary immunoblocking, and subsequently screen other factors in the BMP9 response. Our studies will help identify targets in the BMP9 response system that might be used in designing treatments for AVMs.

项目概要： 血管系统由复杂的网络组成，这些网络的发展与密切调节相结合。 内皮细胞（EC）。了解此类监管对于开发新疗法至关重要 针对血管畸形的策略，例如动静脉畸形（AVM）和遗传性畸形 出血性毛细血管扩张症 (HHT)，由激活素受体样激酶 1 (ALK1) 突变引起。 我们之前表明，小鼠基质 Gla 蛋白（MGP）（一种骨抑制蛋白）的基因缺失 形态发生蛋白 (BMP) 会在多个器官中引起 AVM，类似于 HHT。我们证明了 BMP9/ALK1 信号传导诱导 EC 中 MGP 的表达，其中 MGP 在分化中发挥重要作用。 BMP9/ALK1 信号传导还以不同的诱导延迟诱导 Crossveinless-2 (CV2)，从而产生两个负 反馈循环。 MGP 和 CV2 通过以前未知的机制共同调节 BMP9 信号传导。在 在培养的 EC 中，我们发现 MGP 和 CV2 表达的振荡在时间上协调向 EC 的转变 EC 中的茎细胞表型。这也导致茎细胞标记物振荡，而尖端细胞标记物则振荡。 压制。删除 Mgp 消除了振荡行为。在体内，MGP 和 CV2 被视为“塑造 正在生长的视网膜中出现“波浪”或条纹，并且 MGP 的缺乏扰乱了血管网络。 我们的假设是 MGP 和 CV2 通过以下方式调节 BMP9 信号传导和血管形态发生 表达振荡或波的产生。在目标 1 中，我们将描述 MGP 和 CV2 如何协调 使用基因表达振荡响应 BMP9 的 EC 分化。我们将把 BMP9 诱导的 茎细胞表型与振荡的关系，并探索具有这种行为能力的 EC 的表达谱。我们将 使用 shRNA 的既定技术，通过在体外删除 Mgp 基因来破坏系统，并确定 对抑制剂和茎细胞标记物波的影响。我们还将调查 MGP 和 CV2 可以在正常脉管系统中检测到，重点是视网膜。在目标2中，我们将获得关键信息 通过删除 Mgp、损害 MGP 蛋白功能，了解 MGP 在视网膜血管网络和 AVM 中的作用， 并调节细胞起源。我们将使用 Mgp-/- 小鼠调节 AVM 治疗的潜在目标 作为 AVM 模型。我们将从 CV2 的调制开始，并使用包括与 对小鼠进行基因改造和跨乳房免疫阻断，然后筛选小鼠体内的其他因素 BMP9 响应。我们的研究将有助于确定 BMP9 响应系统中可能用于 设计 AVM 的治疗方法。