Defining the role of extracellular matrix mechanics in vascular Ehlers-Danlos syndrome

项目总结 血管Ehler-Danlos综合征(EDS IV型，vEDS)是Ehler-Danlos综合征(EDS)的变种，EDS是一个家族 结缔组织疾病的13种亚型--这是由COL3A1基因突变引起的。 这些突变导致血管ECM中III型胶原减少，通常导致主动脉夹层和 动脉瘤，导致血管破裂。在vEDS和其他EDS变体中，有证据表明ECM内容， 蛋白质的结构和机械性能被改变。血管内皮细胞(ECs)感知并响应 ECM的成分和机械性能，以及ECM的病理变化，包括僵硬增加， 可以诱导效应信号，导致血管通透性增加和分泌因子，如 血管内皮生长因子和一氧化氮。这种EC表型和功能的变化，广义地说 导致血管内皮功能障碍，并可导致血管疾病，如动脉瘤的形成。我 假设COL3A1基因突变会改变ECM的机械性能，作为蛋白质含量的结果 ECM的结构变化，导致EC功能障碍，导致血管系统减弱。这就做 用体外和体内相结合的方法解决这一假说有三个目的。在《目标1》中，我将 解决COL3A1突变对细胞外基质成分和机械性能的影响 体外从vEDS患者来源的细胞中提取基质(CDM)以确定COL3A1突变如何改变弹性和 ECM的粘弹性特性。在目标2中，我将讨论vEDS CDM机械性能的变化 与血管内皮细胞的表型和功能有关。我将分析血管内皮细胞对vEDS CDM的反应 刚性分离ECM蛋白质含量和力学，以确定特定的病理机制 CDM影响内皮细胞表型和血管屏障功能。在目标3中，我将讨论 内皮功能障碍和ECM力学性质的变化在体内疾病进展中的作用。这就做 使用已建立的vEDS小鼠模型研究血管内皮细胞表型和ECM机制 除了血管破裂事件和整体组织脆性之外，还可以探索EC表型变化之间的联系 和主动脉机械衰竭。这项拟议的工作将确定ECM机械性能如何受损 血管内皮细胞信号转导通路对vEDS疾病表现的影响 功能、炎症和机械转导。对这些途径的更好理解将导致新的 VEDS患者的治疗路线--目前FDA还没有批准这些路线。此外，这些 失败的机制可能更广泛地与动脉瘤的形成和进展有关(而不是 仅限于vEDS患者)，并可能有助于进一步研究识别、治疗和预防 动脉瘤。

PROJECT SUMMARY Vascular Ehlers-Danlos syndrome (EDS Type IV, vEDS) is a variant of Ehlers-Danlos syndrome (EDS)—a family of connective tissue disorders with 13 defined subtypes—that is caused by mutations in the COL3A1 gene. These mutations result in reduced collagen III in the vascular ECM and typically leads to aortic dissection and aneurysm, resulting in vessel rupture. In vEDS and other EDS variants there is evidence that ECM content, protein structure, and mechanical properties are altered. Vascular endothelial cells (ECs) sense and respond to ECM composition and mechanical properties, and pathologic changes to ECM, including increased stiffness, can induce effector signaling that results in increased vascular permeability and secretion of factors such as vascular endothelial growth factor and nitric oxide. Such changes in EC phenotype and function, broadly referred to as endothelial dysfunction and can contribute to vascular diseases, such as in aneurysm formation. I hypothesize that mutations in the COL3A1 gene alter ECM mechanical properties, as a result of protein content and structural changes in the ECM, which leads to EC dysfunction and results in weakened vasculature. I will address this hypothesis with three aims using a combination of in vitro and in vivo methods. In Aim 1, I will address the impact of COL3A1 mutations on ECM composition and mechanical properties using cell-derived matrix (CDM) from vEDS patient-derived cells in vitro to determine how mutations in COL3A1 alter elastic and viscoelastic properties of ECM. In Aim 2, I will address how changes in mechanical properties of vEDS CDM relates to vascular EC phenotype and function. I will analyze endothelial cell response to vEDS CDM with varying stiffness to decouple ECM protein content and mechanics to define specific mechanisms by which pathologic CDM influences endothelial cell phenotype and vascular barrier function. In Aim 3, I will address the impact of both endothelial dysfunction and changes in ECM mechanical properties on disease progression in vivo. I will use an established mouse model of vEDS to investigate both endothelial cell phenotype and ECM mechanics in addition to vascular rupture events and overall tissue fragility to probe the link between changes in EC phenotype and aortic mechanical failure. This proposed work will identify how compromised ECM mechanical properties impact vEDS disease manifestation through the probing of endothelial cell signaling pathways related to vascular function, inflammation, and mechanotransduction. A better understanding of these pathways will lead to new routes of treatment for vEDS patients – of which there are none currently approved by the FDA. Further, these mechanisms of failure are likely more broadly relevant for aneurysm formation and progression in general (not just in vEDS patients) and may be of help for furthering research of identifying, treating, and preventing aneurysms.