Identifying the role of aortic valve interstitial cells and altered micro-environment on bicuspid aortic valve disease progression.

项目摘要/摘要 二尖瓣主动脉瓣(BAV)是最常见的先天性心脏缺陷，它包含两个瓣膜，而不是二尖瓣 正常的三种，小叶组织。BAVs的病变速度通常比结构正常的主动脉更快 瓣膜(AVs)最常见的原因是钙积聚，最终导致主动脉狭窄(AS)。当前临床 BAV患者AS的治疗仅包括手术选择，如房室修复和置换， 更新换代是更常见的。生物瓣膜通常用于替代方案，尽管 他们有限的寿命为10-15年。在BAV患者的背景下，他们往往在年的早期时间点患病 生命，生物瓣膜不是一个无限期的解决方案，很可能需要后续的外科手术。 或者，机械瓣膜适用于较年轻的BAV患者群体，但需要不确定的 需要抗凝剂，这在很大程度上阻碍了患者的生活质量。因此，没有最佳或不确定的外科手术 目前存在治疗BAV疾病的干预措施。我们实验室和其他实验室之前的工作已经阐明了斯特拉塔 细胞外基质(ECM)组成和结构的差异以及力学性能的差异 动静脉与脑动静脉之间的应力-应变环境。然而，这些变化是如何发生的，目前尚不清楚。 影响BAV间质细胞(BAVIC)功能重塑行为。此外，还开展了有限的工作，以 探讨BAV病是否由BAVICs与正常Av的内在差异所致 间质细胞(AVIC)。我们假设BAVIC的内在差异，改变的微环境， 而改变的BAV小叶株通过细胞介导的ECM重塑促进BAV疾病的进展 和由BAVIC群体表型激活引起的生物合成。我们将解决这一假设 有以下三个目标： 确定BAV内的3D形态和ECM区域变异。我们将利用最新的- ART方法包括3D小角光散射、定量组织学和聚焦离子束扫描 用电子显微镜观察BAV和AVECM的差异。 描述分离的BAVICs和AVICs的生物物理状态和生物合成行为 不同硬度的多肽修饰的聚乙二醇水凝胶。我们将评估其收缩程度 以及分离的BAVICs和AVICs在聚乙二醇水凝胶中的生物合成特性以研究内源性 不同细胞群之间的差异。 模拟BAV小叶株以评估体外BAVIC重塑行为。这里我们将使用单轴 拉伸生物反应器以模拟BAV菌株水平，并评估改变的运动学如何影响BAVIC的反应。

PROJECT SUMMARY/ABSTRACT The bicuspid aortic valve (BAV) is the most common cardiac congenital defect and contains two, as opposed to the normal three, leaflet tissues. BAVs commonly become diseased at a faster rate than structurally normal aortic valves (AVs) most often due to calcium build up which eventually leads to aortic stenosis (AS). Current clinical treatments for AS in BAV patients consist only of surgical options such as AV repair and replacement, with replacement being the more common. Bioprosthetic valves are routinely used in replacement scenarios despite their limited lifespan of 10-15 years. In the context of BAV patients, who tend to disease at earlier time points in life, bioprosthetic valves are not an indefinite solution and will most likely require follow-up surgical operations. Alternatively, mechanical valves are employed for the younger BAV patient population but require the indefinite need for anticoagulants which substantially hinders patient quality of life. Thus, no optimal nor indefinite surgical intervention currently exists to treat BAV disease. Previous work from our lab and others have elucidated drastic differences in extracellular matrix (ECM) composition and structure as well as differences in the mechanical stress-strain environment between AVs and BAVs. However, it has yet to be elucidated as to how these changes affect BAV interstitial cell (BAVIC) functional remodeling behaviors. In addition, limited work has been done to explore whether BAV disease may be caused by intrinsic differences between the BAVICs and normal AV interstitial cells (AVICs). We hypothesize that the intrinsic differences of BAVICs, the altered microenvironment, and the altered BAV leaflet strains enhance BAV disease progression through cell-mediated ECM remodeling and biosynthesis brought on by phenotypic activation of the BAVIC population. We will address this hypothesis with the following three aims: Identifying the 3D morphological and ECM regional variations within the BAV. We will utilize state-of-the- art methods including 3D small angle light scattering, quantitative histology, and focused-ion beam scanning electron microscopy to assess the differences in ECM between the BAV and AV. Delineating the biophysical state and biosynthetic behaviors of isolated BAVICs and AVICs within peptide-modified poly (ethylene glycol) (PEG) hydrogels of varying stiffness. We will assess the contractile and biosynthetic properties of isolated BAVICs and AVICs within PEG hydrogels to investigate intrinsic differences among the cell groups. Emulating BAV leaflet strains to assess BAVIC remodeling behaviors in vitro. Here we will use a uniaxial stretch bioreactor to emulate BAV strain levels and assess how altered kinematics affect BAVIC responses.