Mechanism of endothelial cell damage in scleroderma

描述（由申请人提供）： 该项目的长期目标是阐明系统性硬化症（SSc）中微血管损伤和细胞外基质（ECM）沉积上调的分子机制。我们实验室最近的研究强烈表明，转录因子Etsl家族的成员Flil可能有助于SSc病变中不受控制的ECM沉积。我们最近的数据还表明，Flil在健康皮肤的内皮细胞中显著表达，并且在从临床未累及皮肤获得的SSc病变的内皮细胞中下调。Flil在正常成人血管中的具体作用目前尚不清楚。然而，Flil敲除的表型强烈表明Flil参与胚胎发育期间血管重塑和内皮细胞存活。我们假设Flil的下调是导致内皮细胞功能障碍并最终死亡的关键致病事件，同时成纤维细胞的胶原蛋白产生失调。我们提出了两个具体的目标来检验这一假设。在目的1中，我们将使用人真皮微血管内皮细胞（HDMECs）来检查Flil的调节和功能。在目的2中，我们将采用HDMECs和真皮成纤维细胞的三维器官型共培养来确定Flil在毛细血管网络形成中的作用。一旦优化，该实验模型将使我们能够更接近地再现健康和SSc皮肤中存在的生理和病理条件。这些研究可能有助于我们解开疾病的分子基础，并最终为治疗干预提供合理的目标。

DESCRIPTION (provided by applicant): The long-term objective of this project is elucidation of the molecular mechanisms responsible for microvascular injury and upregulated deposition of the extracellular matrix (ECM) in systemic sclerosis (SSc). Recent studies from our laboratory strongly suggest that a member of the Etsl family of transcription factors, Flil, may contribute to the uncontrolled ECM deposition in SSc lesions. Our recent data also demonstrate that Flil is prominently expressed in endothelial cells in healthy skin and is downregulated in endothelial cells in SSc lesions obtained from clinically uninvolved skin. The specific role of Flil in normal adult vessels is currently unknown. However, the phenotype of Flil knockout strongly suggests that Flil is involved in vascular remodeling and survival of endothelial cells during embryonic development. We hypothesize that downregulation of Flil is a critical pathogenic event that leads to endothelial cell dysfunction and ultimately death, simultaneous with dysregulated collagen production by fibroblasts. We propose two specific aims to test this hypothesis. In Aim 1 we will examine the regulation and function of Flil using human dermal microvascular endothelial cells (HDMECs). In Aim 2 we will employ a three-dimensional organotypic coculture of HDMECs and dermal fibroblasts to determine the role of Flil in capillary network formation. Once optimized, this experimental model will allow us to reproduce more closely the physiologic and pathologic conditions existing in healthy and SSc skin. These studies may help us to unravel the molecular basis of the disease and ultimately provide the logical target for therapeutic intervention.