Investigating the Role of Shear Stress in Coronary Artery Development

研究剪切应力在冠状动脉发育中的作用

• 批准号: 10066608
• 负责人: Ian Miller Williams
• 金额: $ 6.53万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2021-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10066608
• 关键词: Address; Adhesions; Arteries; Biochemical; Biological Models; Biology; Blood Vessels; Blood capillaries; Blood flow; CXCR4 Receptors; Capillary Endothelial Cell; Cardiac; Cause of Death; Cell Differentiation process; Clinical Trials; Confocal Microscopy; Coronary; Coronary Arteriosclerosis; Coronary artery; Data; Development; Disease; Endothelial Cells; Endothelium; Environment; Flow Cytometry; Genes; Genetically Engineered Mouse; Geometry; Goals; Heart; Heart failure; Human; Immunofluorescence Microscopy; In Vitro; Individual; Laboratories; Leukocytes; Measurement; Measures; Modeling; Molecular; Morbidity - disease rate; Mosaicism; Mus; Myocardial Infarction; Myocardial Ischemia; Natural regeneration; Nitric Oxide; Perfusion; Phenotype; Pluripotent Stem Cells; Population; Process; Production; Receptor Signaling; Research; Role; Signal Transduction; Specific qualifier value; System; Testing; Therapeutic; Tissue Engineering; Tissues; To specify; Umbilical vein; Up-Regulation; Work; cell motility; chemokine; endothelial stem cell; experimental study; gene therapy; human model; human pluripotent stem cell; human stem cells; in vitro Model; in vivo; insight; migration; mortality; mouse genetics; novel; programs; recruit; response; shear stress; skills; stem cell differentiation; stem cell model; stem cells

PROJECT SUMMARY/ABSTRACT Coronary artery disease (CAD), the leading cause of death in the U.S., is caused by a narrowing of coronary arteries, the result of which is reduced cardiac perfusion and potentially myocardial infarction and/or heart failure. One promising approach to treating CAD is to regenerate arteries and restore blood flow to ischemic heart tissue. In order to make arterial regeneration a reality for CAD treatment, however, we need a more detailed understanding of how arteries are formed. Previous studies indicate that exposure of endothelial cells (ECs) to blood flow is critical for coronary artery development. Coronary artery formation is a stepwise process involving 1) specification of ECs to an arterial phenotype and 2) migration of capillary ECs into developing arteries. The mechanisms by which blood flow stimulates each of these morphogenic processes are unclear. Previous studies have shown that exposing cultured ECs to shear stress leads to upregulation of artery-specific genes, one key step in arterial EC specification. Furthermore, findings from our laboratory and others have shown that expression of the chemokine Cxcl12 is enriched in the arterial endothelium, a high shear stress environment. We also found that Cxcl12-Cxcr4 (Cxcl12 receptor) signaling promotes the migration of ECs against the direction of flow in vitro. These observations have led me to hypothesize that shear stress both fully arterializes progenitor ECs and stimulates them to release chemokines which attract nearby ECs to the developing artery. I will test this hypothesis by addressing the following Specific Aims. In Specific Aim 1, I will determine the effects of shear stress on arterial specification of ECs. To accomplish this goal, I will utilize a novel in vitro system of human arterial differentiation in which pure populations of arterial ECs can be generated from pluripotent stem cells treated with arterializing biochemical signals. Measuring arterial EC specification in response to different combinations of shear stress and arterializing biochemical signals will reveal molecular mechanisms by which shear stress drives ECs towards an arterial fate. In Specific Aim 2, I will determine the role of chemokines in orchestrating flow-induced EC migration in vivo. Namely, I will perturb EC Cxcl12 – Cxcr4 signaling by using mice in which either Cxcl12 is deleted from arterial ECs or Cxcr4 is deleted from capillary ECs. Assessing coronary artery formation in these mice will allow me to determine whether arterial Cxcl12 – capillary Cxcr4 signaling directs the migration of ECs from environments of low (capillary) to high (artery) shear stress. Results from these studies will generate substantial insight into the mechanisms by which shear stress promotes arterial specification and coronary artery remodeling. Findings from this work may be leveraged therapeutically to develop strategies for regenerating arteries in vivo or generating tissue-engineered arteries in vitro.

项目概要/摘要 冠状动脉疾病 (CAD) 是美国的首要死因，是由冠状动脉狭窄引起的 动脉，其结果是心脏灌注减少并可能导致心肌梗塞和/或心力衰竭。 治疗 CAD 的一种有前途的方法是再生动脉并恢复缺血心脏组织的血流。 然而，为了使动脉再生成为 CAD 治疗的现实，我们需要更详细的研究 了解动脉是如何形成的。先前的研究表明，内皮细胞（EC）暴露于 血流对于冠状动脉的发育至关重要。冠状动脉的形成是一个逐步的过程 1) ECs 对动脉表型的规范和 2) 毛细血管 ECs 迁移到发育中的动脉。这 血流刺激这些形态发生过程的机制尚不清楚。之前的研究 已经表明，将培养的 EC 暴露于剪切应力会导致动脉特异性基因的上调，这是一个关键 动脉 EC 规范中的步骤。此外，我们实验室和其他实验室的研究结果表明 趋化因子 Cxcl12 的表达在高剪切应力环境的动脉内皮细胞中富集。 我们还发现Cxcl12-Cxcr4（Cxcl12受体）信号传导促进ECs逆向迁移 体外流动。这些观察使我推测剪切应力既使祖细胞完全动脉化 EC 并刺激它们释放趋化因子，将附近的 EC 吸引到发育中的动脉。我会测试 通过解决以下具体目标来实现这一假设。在具体目标 1 中，我将确定剪切力的影响 ECs 动脉规格的压力。为了实现这一目标，我将利用一种新型的人体体外系统 动脉分化，其中可以从多能干细胞产生纯动脉 EC 群 用动脉化生化信号进行治疗。测量动脉 EC 规格以响应不同的情况 剪切应力和动脉生化信号的组合将揭示分子机制 剪切应力驱使内皮细胞走向动脉命运。在具体目标 2 中，我将确定趋化因子在 协调流动诱导的 EC 体内迁移。也就是说，我将通过使用扰乱 EC Cxcl12 – Cxcr4 信号 动脉 EC 中删除 Cxcl12 或毛细血管 EC 中删除 Cxcr4 的小鼠。评估 这些小鼠的冠状动脉形成将使我能够确定动脉 Cxcl12 – 毛细血管 Cxcr4 是否 信号传导引导内皮细胞从低（毛细血管）剪切应力环境迁移到高（动脉）剪切应力环境。结果 这些研究将深入了解剪切应力促进动脉粥样硬化的机制。 规格和冠状动脉重塑。这项工作的发现可用于治疗 制定体内动脉再生或体外生成组织工程动脉的策略。