The effect of laminar and disturbed flow on endothelial glucose metabolism

血管内皮细胞代谢最近重新成为调节血管功能的有力工具。然而， 研究完全集中在通过PFKFB3调节糖酵解通量及其在血管生成中的作用。小才是 了解血管内皮细胞代谢如何影响健康和疾病中的大血管内皮细胞功能。 血管内皮细胞不断地暴露在流动的血液的剪切力下。内皮细胞处于稳定状态 层流表示一种静止的表型，通过控制增殖来维持血管的动态平衡。 渗透性、炎症和血管紧张性。振荡扰动流中的内皮细胞表达动脉粥样硬化- 增殖性、通透性和炎性黏附分子表达增高的倾向表型 以及NO产生受损(定义为内皮功能障碍)。扰动流动区域连接到 随后的病理性血管重塑包括动脉粥样硬化斑块的形成。 最近，处于稳定层流中的内皮细胞部分地通过KLF2介导的抑制糖酵解来减少糖酵解。 PFKFB3.然而，同时过表达KLF2和PFKFB3并不能完全恢复糖酵解率， 这表明其他新陈代谢介质也参与其中。我们的数据显示内皮细胞处于稳定状态 层流在较短时间内减少糖酵解通量，而不改变PFKFB3表达，且内皮细胞 处于振荡扰动流中的细胞不会降低糖酵解通量。我们的数据还表明，流量调节 氨基己糖生物合成途径，糖酵解的一个侧枝，控制蛋白质O-GlcN酰化，以及乙酰化 辅酶A对脂质合成和组蛋白乙酰化起关键作用。我们才刚刚开始发现 剪切力影响内皮细胞葡萄糖代谢和下游途径的机制。 我们的长期目标是调节葡萄糖代谢，以减少血流紊乱时的内皮功能障碍。 这个项目的目标是了解定常层流和振荡扰动流对不同的影响。 大血管内皮细胞糖酵解通量、HBP和乙酰辅酶A代谢。我们假设平均切变 超过12dynes/cm2的应激会降低糖酵解通量、eNOS O-GlcN酰化和乙酰辅酶A以促进 抗动脉粥样硬化的内皮细胞表型。为了检验这一假设，我们将(1)确定稳定的层流和 振荡扰动流调节内皮细胞糖酵解通量；(2)确定稳定的层流和 振荡扰动流影响eNOS O-GlcN酰化；以及(3)确定乙酰辅酶A如何改变 流动影响脂肪合成和组蛋白乙酰化 由于动脉粥样硬化是一种代谢改变的疾病，我们将使用体外和体外相结合的方法 发现葡萄糖代谢随血流变化的潜在机制的实验。我们的团队是独一无二的 准备从事这项研究，拥有内皮血流动力学、代谢质谱学、O- GlcN酰化和体外血管分析。这些数据将通过创建一个新的研究领域来改变该领域 处于血流动力学和代谢组学的交汇点。

Endothelial metabolism has recently re-emerged as a powerful tool to regulate vascular function. However, studies have focused entirely on glycolytic flux regulation via PFKFB3 and its effects in angiogenesis. Little is known about how endothelial cell metabolism impacts macrovascular endothelial function in health and disease. Endothelial cells are constantly exposed to shear stress from the flowing blood. Endothelial cells in steady laminar flow express a quiescent phenotype, maintaining vascular homeostasis through control of proliferation, permeability, inflammation, and vascular tone. Endothelial cells in oscillating disturbed flow express an athero- prone phenotype with elevated proliferation, permeability, and inflammatory adhesion molecule expression as well as impaired NO production (defined as endothelial dysfunction). Disturbed flow regions are linked to subsequent pathological vascular remodeling including atherosclerotic plaque development. Recently, endothelial cells in steady laminar reduced glycolysis partially via KLF2-mediated repression of PFKFB3. However, concurrent KLF2 and PFKFB3 overexpression did not fully restore glycolytic rate, suggesting that other metabolic mediators are involved. Our data show that endothelial cells in steady laminar flow reduce glycolytic flux at shorter times with no change in PFKFB3 expression, and that endothelial cells in oscillating disturbed flow do not decrease glycolytic flux. Our data also show that flow regulates the hexosamine biosynthetic pathway, a side branch of glycolysis which controls protein O-GlcNAcylation, and acetyl CoA, which is critical to lipid synthesis and histone acetylation. We are only beginning to discover mechanisms by which shear stress affects endothelial glucose metabolism and downstream pathways. Our long term goal is to modulate glucose metabolism to reduce endothelial dysfunction in disturbed flow. The goal of this project is to understand how steady laminar and oscillating disturbed flow differentially affect macrovascular endothelial glycolytic flux, the HBP, and acetyl CoA metabolism. We hypothesize that mean shear stress greater than 12 dynes/cm2 reduces glycolytic flux, eNOS O-GlcNAcylation, and acetyl CoA to promote an athero-protective endothelial phenotype. To test this hypothesis, we will (1) determine how steady laminar and oscillating disturbed flow regulate endothelial glycolytic flux; (2) determine how steady laminar and oscillating disturbed flow affect eNOS O-GlcNAcylation; and (3) determine how altered acetyl CoA in flow impacts lipid synthesis and histone acetylation Since atherosclerosis is a disease of altered metabolism, we will use a combination of in vitro and ex vivo experiments to discover mechanisms underlying changes in glucose metabolism with flow. Our team is uniquely prepared to pursue this research, with expertise in endothelial hemodynamics, metabolic mass spectrometry, O- GlcNAcylation, and ex vivo vessel analysis. These data will transform the field by creating a new research area at the intersection of hemodynamics and metabolomics.