Molecular Pathogenesis of Brain Arteriovenous Malformation

脑动静脉畸形的分子发病机制

• 批准号: 9065648
• 负责人: Rong Wang
• 金额: $ 35.06万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9065648
• 关键词: ACVRL1 gene; Adult; Aorta; Area; Arteries; Blood; Blood Vessels; Blood capillaries; Blood flow; Brain; Cardinal vein; Cephalic; Cerebrovascular system; Custom; Data; Development; Disease; Dorsal; Down-Regulation; Embryo; Endothelial Cells; Epilepsy; Functional disorder; Genes; Genetic; Genetic screening method; Goals; Health; Human; Image; Imaging technology; Induced Mutation; Inherited; Investigation; Life; Ligands; Ligation; Measures; Mediating; Methods; Microscope; Molecular; Mus; Mutant Strains Mice; Mutation; Nitric Oxide; Nitric Oxide Synthetase Inhibitor; Nitroarginine; Operative Surgical Procedures; Pathogenesis; Pathology; Pathway interactions; Patients; Phenotype; Physiologic arteriovenous anastomosis; Physiology; Process; Radiation therapy; Regulation; Reporting; Resolution; Role; Signal Transduction; Stimulus; Stroke; Testing; Time; Up-Regulation; Veins; Venous; Work; base; brain arteriovenous malformations; capillary; design; endothelial dysfunction; fluorescence microscope; gain of function; gene function; hemodynamics; innovation; loss of function; loss of function mutation; malformation; middle cerebral artery; molecular marker; mutant; new therapeutic target; notch protein; novel; postnatal; response; shear stress; success; therapeutic target; two-photon

 DESCRIPTION (provided by applicant): Brain arteriovenous (AV) malformations (BAVMs) can cause life-threatening strokes and have limited treatment options. The goal for this project is to elucidate the cellular and molecular mechanisms underlying BAVM pathogenesis to identify novel candidates as therapeutic targets to ameliorate this disease. AVMs are characterized by abnormal AV shunts that displace intervening capillaries. We propose a cross-disciplinary approach, fusing cutting-edge mouse genetics and imaging technologies, to test our hypothesis that Notch mutations can reprogram AV identity and alter AV differential nitric oxide (NO) signaling, and thus endothelial dysfunction, to elicit BAVMs. Notch receptors and ligands are expressed in arteries but not veins. Notch signaling promotes arterial at the expense of venous differentiation by enhancing arterial and suppressing venous molecular markers. We have reported that endothelial expression of a constitutively active Notch4 mutation (Notch4*) elicits BAVMs in mice. Notch4* reprograms veins to gain arterial and lose venous molecular identity, and correcting the causal Notch4* leads to normalization of established BAVMs. We have built a custom two-photon microscope, optimal for structural and hemodynamic imaging of cerebral vasculature in live mice. We can thus obtain 5D data (3D plus blood velocity over time) through a cranial window to reveal the process of BAVM formation in mice. Built on our strong background and preliminary data, we propose: Aim 1 - Determine the effect of endothelial Notch4* on venous endothelial dysfunction and BAVM formation. We will test our hypothesis that Notch4* upregulates NO levels in the veins, alters venous endothelial response to blood flow, and thus permits AVM formation. We will examine the effect of Notch4* on venous NO signaling, endothelial response to blood flow, and flow mediated BAVM formation; Aim 2 - Determine the effect of endothelial Notch deficiency on arterial endothelial dysfunction and BAVM formation. We will test our hypothesis that loss of endothelial Notch gene function reduces arterial NO signaling, leading to arterial dysfunction and thus AVMs. We will analyze mice with endothelial deletion of Rbpj for BAVM pathology, arterial NO signaling, and endothelial response to blood flow stimuli; Aim 3 - Compare Notch and Alk1 mouse mutants in DA and CV development and BAVM formation. We will test our hypothesis that Notch interacts with Hereditary Hemorrhagic Telangectasia (HHT) 2 (or Alk1) in AV differentiation and AVM formation. We will compare the Notch and HHT mutant phenotypes using two-photon imaging and 3D rendering and perform genetic rescue. The findings from this study will conceptually advance our understanding of the cellular and molecular mechanisms of AVM pathogenesis, reveal novel functions for Notch in regulating the unique physiology of arteries and veins, and uncover interactions between the Notch and HHT pathways. The success of this work will inspire new areas of investigation in the fields of AVMs, Notch signaling, and vascular pathophysiology.

 描述（由适用提供）：脑动脉静脉（AV）畸形（BAVM）可能会导致威胁生命的中风，并且治疗方案有限。该项目的目的是阐明BAVM发病机理上的细胞和分子机制，以鉴定新的候选者作为改善该疾病的治疗靶标。 AVM的特征是异常的AV分流，可取代中间的毛细血管。我们提出了一种跨学科的方法，融合了尖端的小鼠遗传学和成像技术，以检验我们的假设，即缺口突变可以重新编程AV身份并改变AV差异一氧化氮（NO）信号传导，从而使内皮功能障碍，从而引起BAVM。 Notch受体和配体在动脉中表达，而不是静脉。 Notch信号传导通过增强动脉和抑制静脉分子标记物来促进动脉。我们报告说，组成型活性Notch4突变（Notch4*）的内皮表达在小鼠中引起BAVM。 Notch4*重编程静脉以获得动脉并失去静脉分子身份，并纠正因果凹槽4*导致已建立的BAVM的归一化。我们已经构建了一个定制的两光子显微镜，最适合活小鼠脑血管的结构和血液动力学成像。因此，我们可以通过颅窗获得5D数据（随着时间的推移，3D加血速度），以揭示小鼠中BAVM形成的过程。我们提出的是基于我们强大的背景和初步数据，目的1-确定内皮缺乏对静脉内皮功能障碍和BAVM形成的影响。我们将检验我们的假设，即Notch4*上调静脉中没有水平，改变对血流的静脉内皮反应，从而允许AVM形成。我们将研究Notch4*对静脉无信号传导，对血流的内皮反应以及流动介导的BAVM形成的影响；目标2-确定内皮缺陷缺乏对伪影内皮功能障碍和BAVM形成的影响。我们将测试我们的假设，即内皮缺口基因功能的丧失会降低伪像没有信号传导，从而导致伪影功能障碍，从而导致AVM。我们将用RBPJ的内皮缺失分析BAVM病理学，无信号传导和对血液流动刺激的内皮反应的小鼠； AIM 3-在DA和CV发育以及BAVM形成中比较Notch和Alk1小鼠突变体。我们将检验我们的假设，即Notch与遗传性出血性毛道症（HHT）2（或ALK1）相互作用。我们将使用两光子成像和3D渲染并进行遗传救援来比较缺口和HHT突变体表型。这项研究的发现将从概念上提高我们对AVM发病机理的细胞和分子机制的理解，揭示了Notch在调节动脉和静脉独特生理学中的新功能，并发现了Notch和HHT途径之间的相互作用。这项工作的成功将激发AVM，Notch信号和血管病理生理学领域的新调查领域。