EphA2 signaling in atherosclerotic fibroproliferative remodeling

EphA2信号在动脉粥样硬化纤维增殖性重塑中的作用

• 批准号: 10063548
• 负责人: Anthony Wayne Orr
• 金额: $ 44.55万
• 依托单位: LOUISIANA STATE UNIV HSC SHREVEPORT
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-12-15 至 2022-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10063548
• 关键词: Affect; Arterial Fatty Streak; Atherosclerosis; Cancer Model; Cell Culture Techniques; Cell Proliferation; Data; Deposition; Development; Endothelium; Eph Family Receptors; Ephrins; Family; Fibronectins; Human; In Vitro; Inflammation; Integrin Binding; Integrins; Knockout Mice; Ligands; Ligation; MAPK3 gene; Modeling; Pathologic; Phenotype; Phosphorylation; Phosphotransferases; Process; Proteomics; Proto-Oncogene Proteins c-akt; Receptor Protein-Tyrosine Kinases; Research; Role; Signal Transduction; Site; Smooth Muscle; Smooth Muscle Myocytes; Testing; Tumor Suppressor Proteins; Vascular remodeling; Work; cell motility; cell type; conditional knockout; in vivo; inhibitor/antagonist; mammalian genome; member; migration; novel; response; treatment response; virtual

Project Summary The Eph family of receptor tyrosine kinases, the largest in the mammalian genome, and their ephrin ligands critically influence inflammation in a variety of pathological conditions. Our work provided the first description of EphA2 expression in multiple cell types in the atherosclerotic plaque, and we recently demonstrated that EphA2 deletion reduces atherosclerotic plaque formation associated with diminished plaque inflammation. Surprisingly, EphA2 deletion also reduced progression to advanced atherosclerotic disease with diminished plaque smooth muscle content. Phenotypic modulation of smooth muscle cells from a contractile to a synthetic phenotype drives their accumulation during plaque development, and smooth muscle cells show enhanced EphA2 expression during phenotypic modulation both in vitro and in vivo. Our preliminary data show that matrix remodeling that promotes fibronectin-dependent integrin signaling critically regulates EphA2 expression during phenotypic modulation, whereas blunting EphA2 expression limits fibronectin matrix deposition in vivo and in vitro. Taken together, these data suggest a dynamic interplay between EphA2 and matrix remodeling that critically regulates the smooth muscle matrix deposition. In addition to matrix deposition, we also demonstrated a critical role for EphA2 expression in smooth muscle mitogenic signaling (ERK1/2, AKT) and proliferation both in vitro and in atherosclerotic plaques in vivo. While EphA2 ligation by ephrinA1 elicits multiple aspects of EphA2's atherogenic proinflammatory responses, our preliminary data show that EphA2 ligation reduces smooth muscle proliferation. Conversely, EphA2 can also signal in a ligand-independent state, which promotes cell proliferation and migration in cancer models, and we observed an increase in EphA2 ligand-independent signaling (Ser897 phosphorylation) during smooth muscle proliferation in vitro and at sites of smooth muscle phenotypic modulation in vivo. However, the mechanisms regulating EphA2's differential ligand-dependent and ligand-independent mitogenic signaling remain virtually unexplored. Therefore, we hypothesize that dynamic interplay between EphA2 expression and matrix remodeling in the atherosclerotic plaque drives smooth muscle invasion and fibroproliferative remodeling through activation of EphA2 ligand-independent signaling. To test this hypothesis, we will characterize the dynamic interplay between EphA2 expression and matrix composition using both cell culture models and smooth muscle- specific deletion of fibronectin and fibronectin-binding integrins (Aim 1), we will determine the mechanisms by which EphA2 signaling affects smooth muscle phenotype (Aim 2), and we will assess the role of EphA2 cell-type specific expression and signaling in atherosclerotic fibroproliferative remodeling using novel EphA2 conditional knockouts and inhibitors of EphA2 ligation and kinase activity. Successful completion of these Aims will identify a novel mechanism to selectively reduce plaque-associated inflammation while promoting smooth muscle- dependent stabilization of the fibrous cap.

项目摘要 Eph受体酪氨酸激酶家族是哺乳动物基因组中最大的受体，以及它们的ePhin配体 在各种病理条件下严重影响炎症反应。我们的工作首次描述了 EphA2在动脉粥样硬化斑块中多种细胞类型的表达，我们最近证实EphA2 缺失可减少与减少斑块炎症相关的动脉粥样硬化斑块的形成。令人惊讶的是， EphA2缺失也减少了进展为晚期动脉粥样硬化性疾病，斑块平滑程度降低 肌肉含量。平滑肌细胞从收缩表型到合成表型的表型转换驱动 它们在斑块形成过程中积聚，血管平滑肌细胞显示EphA2表达增强 在体外和体内的表型调节过程中。我们的初步数据显示，基质重塑 促进纤维连接蛋白依赖的整合素信号在表型过程中关键调节EphA2的表达 而钝化EphA2的表达则限制了体内和体外纤维连接蛋白基质的沉积。已被占用 总而言之，这些数据表明EphA2和基质重塑之间存在着动态的相互作用，这种相互作用对 平滑肌基质沉积。 除了基质沉积，我们还证明了EphA2在平滑肌中表达的关键作用 有丝分裂信号(ERK1/2，AKT)与体外和体内动脉粥样硬化斑块的增殖。而当 EphA1结扎EphA2可引起多方面的EphA2‘S致动脉粥样硬化性炎症反应 初步数据显示，EphA2结扎减少了平滑肌的增殖。相反，EphA2还可以 在非配体状态下的信号，在癌症模型中促进细胞的增殖和迁移，我们 观察到在平滑肌过程中EphA2配体非依赖性信号(Ser897磷酸化)的增加 体外增殖和体内平滑肌表型改变部位。然而，这些机制 调控EphA2‘S差异配基依赖和非配基依赖的有丝分裂信号实际上仍然存在 未被开发的。因此，我们假设EphA2表达和基质之间的动态相互作用 动脉粥样硬化斑块中的重塑通过以下途径驱动平滑肌侵袭和纤维增殖性重塑 激活EphA2配体非依赖的信号通路。为了检验这一假设，我们将描述动态 EphA2表达和基质组成之间的相互作用，使用两种细胞培养模型和平滑肌- 特异性缺失纤维连接蛋白和纤维连接蛋白结合整合素(目标1)，我们将通过以下方式确定其机制 哪些EphA2信号会影响平滑肌表型(目标2)，我们将评估EphA2细胞类型的作用 新型EphA2条件蛋白在动脉粥样硬化性纤维增生性重构中的特异性表达和信号转导 EphA2连接和激酶活性的敲除和抑制物。成功完成这些目标将确定 一种新的机制，选择性地减少斑块相关性炎症，同时促进平滑肌- 纤维帽的依存性稳定。