Proteoglycan Metabolism During Cardiac Valve Development and Disease

心脏瓣膜发育和疾病期间的蛋白多糖代谢

基本信息

批准号：
10543104
负责人：
Christine Bruins Kern
金额：
$ 53.45万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-01-01 至 2025-12-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10543104
关键词：
ADAMTS Active Sites Adult Affect Amino Acids Aneurysm Aorta Aortic Rupture Arteries Behavior Blood Vessels Blood flow Cardiac Cardiovascular system Cell Lineage Cells Coronary artery Data Defect Degenerative polyarthritis Development Disease Elasticity Endothelium Event Exhibits Extracellular Matrix Fetus Heart Valves Human Individual Investigation Label Lasers Mesenchymal Metabolism Modeling Molecular Morphology Mus Mutation Myocardial Neural Crest Organ Patients Pattern Penetrance Pharmaceutical Preparations Pregnant Women Prevalence Proteoglycan Publishing Reporting Reproducibility Research Risk Factors Role Rupture Signal Transduction Stromelysin 1 Sudden Death Testing Therapeutic Tissues aggrecan aortic valve aortic valve disorder ascending aorta bicuspid aortic valve cell behavior comorbidity congenital heart disorder design experimental study in vivo inhibitor insight malformation mouse model new therapeutic target prevent side effect targeted sequencing therapeutic target therapeutically effective transcriptome sequencing versican

项目摘要

Summary: Approximately 1.5% of individuals have a Bicuspid Aortic Valve (BAV) that can result in insufficient blood flow and organ damage (1, 2). A BAV is also an independent risk factor for ascending aortic wall complications that can lead to rupture and sudden death. However, the cell and molecular basis for the BAV is unknown. Even basic aspects of BAV formation are undefined due to contributions from multiple cell lineages and a lack of highly penetrant viable BAV mouse models. Dysfunctional aortic valves exhibit massive accumulation of the extracellular matrix (ECM) proteoglycans versican (Vcan) and aggrecan (Acan) (3-7) but the origin and consequence of excess proteoglycans is largely unknown. Since proteoglycans are highly stable, abundance is regulated primarily by proteolytic degradation which led us to investigate a role for proteoglycan cleavage. We discovered that loss of a single ECM proteoglycanase, Adamts5, results in enlarged aortic valves with ascending aortopathies (100%). These defects co-localize with substantial increases in Vcan and Acan in the affected tissues (8-10) that mirror the human condition. Mechanistically, in Adamts5-/- aortic valve primordia with excess Vcan there is a reduction of pSmad2, and when Smad2 is reduced further by generating Adamts5-/- ;Smad2+/- mice, there is a high penetrance of BAV (75%), much higher than seen in other mouse BAV models. The objective of this proposal is to utilize the viable Adamts5-/-;Smad2+/- mice that exhibit a high percentage of BAV, to define morphological events, cell behaviors and factors that when disrupted contribute to BAV formation. Since excess Vcan is a hallmark of dysfunctional and diseased valves, use of a model with mutations that impact the control of Vcan content, may shed light on how proteoglycan metabolism is regulated in development and may also give insight into disease. Experiments test the hypothesis that ECM Vcan cleavage coordinates mesenchymal cell behaviors and myocardial cell contributions that are required for the tricuspid morphology of aortic valves. The hypothesis is tested in two aims: Aim 1 tests the impact of altered Vcan cleavage on mesenchymal cell lineage behaviors that are required for aortic valve formation. Our preliminary data show that loss of Vcan cleaved fragments and excess intact Vcan, disrupted lineage-specific patterning in the developing aortic valves of the BAV Adamts5-/-;Smad2+/-mice. A combination of ex vivo, and in vivo approaches will decipher the lineage-specific cell behaviors, and guidance factors that are dependent on Vcan cleavage and to prevent BAV. Although dogma states that valve cusps arise from mesenchymal cells, Aim 2 investigates the consequence of excess Vcan on the myocardial cell lineage contributions to the developing aortic valve in Adamts5-/-;Smad2+/- mice and other murine models of BAV. Our preliminary data show myocardial lineage expression of Adamts5 is required to clear Vcan-rich ECM and to form the non-coronary cusp of the aortic valve. Due to the emerging prevalence of excess Vcan in BAV, the investigation into ECM turnover will allow insight into the molecular and cellular origins of aortic valve diseases, which may lead to therapeutic advances.

摘要：大约1.5％的个体具有双质主动脉瓣（BAV），这可能导致不足血流和器官损伤（1，2）。 BAV也是上升主动脉壁的独立危险因素可能导致破裂和猝死的并发症。但是，BAV的细胞和分子基础为未知。由于多个细胞谱系的贡献，即使是BAV形成的基本方面也是不确定的并且缺乏高度渗透的可行BAV小鼠模型。功能失调的主动脉瓣表现出巨大的细胞外基质（ECM）蛋白聚糖versican（Vcan）和Aggrecan（Acan）（3-7）的积累（3-7）过量蛋白聚糖的起源和后果在很大程度上是未知的。由于蛋白聚糖很稳定，丰度主要由蛋白水解降解来调节，这使我们研究了蛋白聚糖的作用乳沟。我们发现单个ECM蛋白聚糖酶ADAMTS5的损失导致主动脉瓣扩大与升高性主动脉息（100％）。这些缺陷与VCAN和ACAN的大幅增加共定位影响人类状况的受影响组织（8-10）。从机械上讲，在Adamts5 - / - 主动脉瓣原始随着过量的VCAN，PSMAD2的降低，当Smad2通过产生Adamts5 - / - 进一步降低时 ; smad2 +/-鼠标，BAV的渗透率很高（75％），比其他小鼠BAV模型中所见。该提案的目的是利用可行的Adamts5 - / - ; Smad2 +/-鼠标，显示出很大比例的 BAV，定义形态事件，细胞行为和破坏有助于BAV形成的因素。由于多余的VCAN是功能失调和患病阀的标志，因此使用具有影响突变的模型 VCAN含量的控制，可能会阐明蛋白聚糖的代谢如何在发育和也可能会深入了解疾病。实验检验了ECM VCAN裂解坐标的假设间充质细胞行为和心肌细胞的贡献，这些细胞的贡献是三尖瓣形态所必需的主动脉瓣。该假设在两个目的中进行了检验：AIM 1测试VCAN裂解改变的影响主动脉瓣形成所需的间充质细胞谱系行为。我们的初步数据表明 VCAN裂片碎片的丢失和多余的VCAN，在发育中的谱系特异性构图破坏 BAV ADAMTS5 - / - ; SMAD2 +/-鼠标的主动脉瓣。离体和体内方法的结合将破译谱系特异性细胞行为以及取决于VCAN裂解并防止的指导因素 bav。尽管教条指出阀cusp是由间充质细胞引起的，但AIM 2研究了多余的VCAN在心肌细胞谱系上对发育主动脉瓣的贡献的结果 adamts5 - / - ; smad2 +/-小鼠和其他BAV的鼠模型。我们的初步数据显示心肌血统需要ADAMTS5的表达来清除富含VCAN的ECM并形成主动脉瓣的非冠状尖端。由于BAV中多余的VCAN的出现率，对ECM周转的调查将允许见解进入主动脉瓣疾病的分子和细胞起源，这可能导致治疗进展。