ROS Mechanisms in BAV Aortopathy

BAV 主动脉病中的 ROS 机制

• 批准号: 8292372
• 负责人: Thomas Gillette Gleason
• 金额: $ 58.37万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8292372
• 关键词: 3-Dimensional; Abbreviations; Age; Aneurysm; Aortic Aneurysm; Architecture; Bicuspid; Biochemistry; Biomechanics; Blood Vessels; Caliber; Caring; Cause of Death; Cell Survival; Cells; Clinical; Collagen; Collagen Fiber; Confocal Microscopy; Congenital Abnormality; Congenital Heart Defects; Data; Detection; Development; Diagnostic; Dissection; Early Diagnosis; Ehlers-Danlos Syndrome; Elastin; Elastin Fiber; Electron Spin Resonance Spectroscopy; Enzymatic Biochemistry; Exhibits; Extracellular Matrix; Fluorescence; Generations; Genes; Goals; High Pressure Liquid Chromatography; Histology; Hospital Mortality; Human; Image; In Vitro; Individual; Knowledge; Matrix Metalloproteinases; Mediating; Microscopy; Modeling; Molecular; Morphology; Mutation; Operative Surgical Procedures; Oxidative Stress; Patients; Phenotype; Population; Property; Reactive Oxygen Species; Research; Research Design; Research Personnel; Risk; Rupture; Smooth Muscle Myocytes; Specimen; Spin Trapping; Staging; Techniques; Testing; Thoracic Aortic Aneurysm; Time; Tissue Banking; Tissue Banks; United States; adjudicate; aortic valve; ascending aorta; base; biological adaptation to stress; cohort; febuxostat; improved; inhibitor/antagonist; innovation; mortality; multi-photon; novel strategies; prevent; scaffold; second harmonic; sex; tissue culture; tool

DESCRIPTION (provided by applicant): This project will test the hypothesis that reactive oxygen species (ROS) accumulation in aortic smooth muscle cells (SMCs) mediates the aortopathy in patients with bicuspid aortic valve (BAV). The interdisciplinary investigative team possesses a unique composition of expertise and has devised a novel approach to prove that ROS accumulation in BAV-ascending aortic aneurysm (TAA) specimens leads to de-differentiation of SMCs, abnormal extracellular matrix (ECM) composition and architecture and altered biomechanical strength of the aortic wall. The hypothesis is supported by the team's strong preliminary data demonstrating ROS accumulation, reduced cell viability in the presence of ROS, diminished oxidative stress responses, de- differentiation of SMCs, disrupted matrix architecture and altered biomechanical tensile and delamination strengths in the ascending aorta of BAV patients compared with tricuspid aortic valve (TAV)-TAA and non- aneurysmal patients. The innovative strategy is accomplished in a two-aim approach: 1) Define what changes in SMC phenotype, ECM composition and architecture, and biomechanical tensile and delamination strengths are associated with ROS accumulation in BAV aortopathy and 2) Prove that ROS accumulation in aortic SMCs mediates the BAV aortopathy. This study will exploit 1) the PI's extensive tissue bank of human ascending aortic specimens and primary SMCs isolated from the following patient cohorts: a) BAV-TAA compared with b) non-aneurysmal BAV, c) TAV-TAA, and d) non-aneurysmal TAV "normal"; and 2) the team's established scaffold-based 3-D tissue culture model. ROS will be evaluated using the investigators' expertise in electron paramagnetic resonance spin trapping and confocal microscopy of fluorescence-based ROS probes. Innovative assessment of ECM composition and architecture will be achieved using multi-photon microscopy with second harmonic generation to define alignment of collagen and elastin fibers, histological detection of collagen and elastin, and quantification of MMP activity. The team's pioneering techniques for studying blood vessel biomechanics will be utilized throughout the research design. This study will, for the first time, define and prove that ROS mechanisms mediate the BAV aortopathy. The results will potentiate significant long-term clinical benefits including the development of improved diagnostic tools for earlier detection and better surveillance of the BAV aortopathy and the discovery of pharmacologic therapies directed at modulation of ROS in the aortic wall to prevent aneurysm formation in BAV patients. PUBLIC HEALTH RELEVANCE: Bicuspid aortic valve (BAV) occurs in 1-2% of the population. The ascending aortas of BAV patients are uniformly larger in diameter compared to age- and sex-matched controls, and 45% percent of individuals requiring surgery to replace the ascending aorta because of thoracic aortic aneurysm or dissection have the congenital defect of BAV. Due to a lack of understanding of BAV-associated aortopathy at the cellular and molecular level, care of BAV patients has been limited to surgery only after the end-stage development of aneurysm or dissection thus resulting in a significant clinical problem worldwide: the hospital mortality rate after ascending aortic dissection is over 23% with and over 60% without surgical intervention representing the fifteenth leading cause of death in the United States. Discovery of the mechanism mediating BAV aortopathy will potentiate significant long-term clinical benefits including 1) the development of improved diagnostic tools for earlier detection and better surveillance and 2) the discovery of pharmacologic therapies to preserve aortic wall architecture and integrity to prevent aneurysm formation in BAV patients.

描述（由申请人提供）：本项目将检验主动脉平滑肌细胞（SMC）中活性氧（ROS）蓄积介导二叶式主动脉瓣（BAV）患者动脉病变的假设。跨学科研究团队拥有独特的专业知识组成，并设计了一种新的方法来证明BAV升主动脉瘤（TAA）标本中的ROS积累导致SMC的去分化，异常细胞外基质（ECM）组成和结构以及主动脉壁的生物力学强度改变。该研究小组的初步数据有力地支持了这一假设，这些数据表明，与三尖瓣主动脉瓣（TAV）-TAA和非动脉瘤患者相比，BAV患者的升主动脉中ROS蓄积、ROS存在下细胞活力降低、氧化应激反应减弱、SMC去分化、基质结构破坏以及生物力学拉伸和分层强度改变。该创新策略以两个目标的方法完成：1）确定SMC表型、ECM组成和结构以及生物力学拉伸和分层强度的变化与BAV血管病中的ROS蓄积相关，2）证明主动脉SMC中的ROS蓄积介导BAV血管病。本研究将利用1）PI的大量人升主动脉标本组织库和从以下患者队列中分离的原发性SMC：a）BAV-TAA与B）非囊性BAV，c）TAV-TAA和d）非囊性TAV“正常”;和2）团队建立的基于支架的3-D组织培养模型。将使用研究者在电子顺磁共振自旋捕获和基于荧光的ROS探针的共聚焦显微镜方面的专业知识来评价ROS。ECM组成和结构的创新评估将使用具有二次谐波产生的多光子显微镜来实现，以定义胶原蛋白和弹性蛋白纤维的对齐、胶原蛋白和弹性蛋白的组织学检测以及MMP活性的定量。 该团队研究血管生物力学的开创性技术将在整个研究设计中使用。本研究将首次定义并证明ROS机制介导BAV异位症。这些结果将增强显著的长期临床受益，包括开发用于早期检测和更好地监测BAV动脉瘤病的改进诊断工具，以及发现针对调节主动脉壁中ROS以预防BAV患者动脉瘤形成的药理学疗法。 公共卫生相关性：二叶式主动脉瓣（BAV）发生在1-2%的人群中。与年龄和性别匹配的对照组相比，BAV患者的升主动脉直径均匀较大，并且45%的因胸主动脉瘤或夹层而需要手术置换升主动脉的个体具有BAV的先天性缺陷。由于在细胞和分子水平上缺乏对BAV相关动脉瘤病的了解，BAV患者的护理仅限于动脉瘤或夹层终末期发展后的手术，因此在全球范围内导致了严重的临床问题：升主动脉夹层的住院死亡率超过23%，在美国，没有手术干预的死亡是第十五大死亡原因。发现介导BAV动脉瘤病的机制将增强显著的长期临床受益，包括1）开发用于早期检测和更好监测的改良诊断工具，以及2）发现保护主动脉壁结构和完整性的药理学疗法，以预防BAV患者的动脉瘤形成。