Differential Shear Forces on Endocardial Endothelial Cells Regulate a Fibrotic Spectrum in the Left Ventricular Outflow Tract

项目总结 离散性主动脉瓣下狭窄(DSS)是一种先天性或获得性疾病，约占所有疾病的10% 左心室流出道梗阻4例，以纤维组织环状为特征 在主动脉瓣下方。目前的治疗方法是手术清除梗阻，但不可预测的 DSS的复发和进展导致多次重复手术和随之而来的发病率 成人期。目前的理论假设，改变LVOT几何结构会导致剪应力增加和 最终导致DSS的纤维化；然而，对DSS进展的机制知之甚少。研究项目： 血管内皮细胞表现为炎症增加和表型变化 在心内膜内皮细胞(EEC)中，剪切力的改变，但剪切力的影响还没有被研究。 此外，常驻成纤维细胞参与器官纤维化，包括心脏组织，以响应 改变了细胞因子信号和机械力。我们假设，改变剪切力会导致 EEC的一种炎症反应，它与心脏成纤维细胞(CF)相互作用，控制纤维化 表型对DSS的病理生理有贡献，我们将以三个具体目标来解决这一问题。 目的1.阐明剪切力调节EEC炎症表型的机制。 将利用患者回声数据和计算建模来开发类似于改变的流动的生物反应器 在决策支持系统中。使用这个创新的系统，我们将测试CD-31机械感觉信号在EEC中的作用 对改变的剪力和几何形状的响应。最后，我们将研究剪切力变化的影响。 论EEC与炎性细胞在传播促炎环境中的相互作用。 目的2.确定EEC对改变的剪切力的转导以控制左心室流出道纤维化。我们会 研究EEC对模拟DSS改变的剪切力和免疫反应的内源性MT倾向 细胞间的相互作用。然后，我们将研究EEC的直接和炎症调节效应。 对纤维性细胞外基质的机械感应。最后，我们将研究加强器的影响 EEC-CF串扰上的纤维化诱导的环境，可能会传播纤维化的反应。 目的3.利用患者数据描述侵袭性DSS的表型，以开发预测模型。我们 应首先评估表征侵略性的ECM成分、重塑轮廓和回声数据 人类DSS的各种形式。然后我们将使用这些数据来开发一个多变量计算模型，该模型可以 被用来预测攻击性表型，这将得到验证和测试。 这项建议将改善对患有直接资助计划的儿童的照顾。随着这些目标的实现，创新 关于剪切力对EEC-CF和EEC免疫细胞的影响的工具和新知识将会出现 相声。这些发现对任何血流改变的心血管疾病都有潜在的意义。 与纤维化有关。

PROJECT SUMMARY Discrete subaortic stenosis (DSS) is a congenital or acquired condition that accounts for ~10% of all cases of left ventricular outflow tract (LVOT) obstruction, and is characterized by a ring of fibrous tissue below the aortic valve. Current treatment is surgical removal of the obstruction, but the unpredictable recurrence and progression of DSS leads to multiple repeat surgeries and attendant morbidity into adulthood. Current theories postulate that altered LVOT geometry causes increased shear stress and ultimately fibrosis in DSS; however, little is known about the mechanism of DSS progression. Studies in vascular endothelial cells demonstrated increased inflammation and phenotypic changes in response to altered shear forces, but effects of shear are under-studied in endocardial endothelial cells (EEC). Additionally, resident fibroblasts are implicated in organ fibrosis, including cardiac tissue, in response to altered cytokine signaling and mechanical forces. We hypothesize that that altered shear forces induce an inflammatory response by EEC, which interacts with cardiac fibroblasts (CF) to govern a fibrotic phenotype that contributes to the pathophysiology of DSS, which we will address with three specific aims. AIM 1. Elucidate the mechanisms of how shear forces regulate EEC inflammatory phenotype.First, we shall utilize patient echo data and computational modeling to develop a bioreactor that resembles altered flows in DSS. Using this innovative system, we will then test the role of CD-31 mechanosensory signaling in EEC in response to altered shear forces and geometry. Lastly, we shall investigate the effects of altered shear forces on EEC interactions with inflammatory cells in propagating a pro-inflammatory environment. AIM 2. Determine EEC transduction of altered shear forces to govern fibrosis in the LVOT. We shall investigate EEC propensity towards endoMT in response to simulated DSS altered shear and immune cell interactions. We shall then investigate the direct and inflammatory-mediated effects of EEC mechanosensing on CF that produce a fibrotic ECM. Lastly, we shall study the effect of the stiffer environment induced by fibrosis on EEC-CF crosstalk, which may propagate the fibrotic response. AIM 3. Characterize the aggressive DSS phenotype using patient data to develop a predictive model. We shall first evaluate the ECM composition, remodeling profile and echo data that characterizes the aggressive forms of DSS in humans. We shall then use these data to develop a multivariate computational model that can be used to predict an aggressive phenotype, which will be validated and tested. This proposal will improve the care of children with DSS. With completion of these aims, innovative tools and new knowledge will emerge about the effects of shear force on EEC-CF and EEC-immune cell cross-talk. These findings have potential implications for any cardiovascular disease with altered flow associated with fibrosis.