Insulin-VEGF Signaling Crosstalk in Endothelial Cells

内皮细胞中的胰岛素-VEGF 信号串扰

• 批准号: 7140478
• 负责人: WILLIAM R HUCKLE
• 金额: $ 17.8万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140478
• 关键词: SDS polyacrylamide gel electrophoresis; biological signal transduction; cell cell interaction; cell differentiation; cell proliferation; colorimetry; diabetes mellitus; diabetic angiopathy; embryonic stem cell; glycation; growth factor receptors; human tissue; immunoprecipitation; insulin; insulin receptor; insulin sensitivity /resistance; laboratory mouse; nitric oxide; phosphorylation; receptor expression; small interfering RNA; tissue /cell culture; vascular endothelial growth factors; vascular endothelium; vascular endothelium permeability; western blottings

DESCRIPTION (provided by applicant): Diabetes mellitus afflicts an estimated 18.2 million individuals in the US. Vascular complications of Types 1 and 2 diabetes, including retinopathies, peripheral artery disease, and atherosclerosis, are major contributors to morbidity and mortality in diabetic patients. The vascular endothelium in diabetes is chronically exposed to high concentrations of glucose and advanced glycation end-products (AGE), resulting in "endothelial dysfunction," a condition characterized by altered vascular permeability, reactivity, thrombogenesis and vessel repair. Insulin and vascular endothelial growth factor (VEGF) each have important roles in regulating endothelial cell survival and endothelium-dependent vasorelaxation, and the functions of both signaling agents are compromised in diabetes. In view of the apparent overlap in signaling pathways activated by insulin and VEGF, the proposed studies will test the hypothesis that perturbed crosstalk among these pathways in endothelial cells contributes to the development of endothelial dysfunction under conditions associated with diabetes mellitus. Specifically, these studies aim to determine the effects of VEGF stimulation on endothelial responsiveness to insulin, using human endothelial cell cultures to measure insulin-stimulated signaling protein phosphorylation, nitric oxide production and proliferation/survival. In addition, we will determine whether conditions associated with the diabetic state or insulin resistance affect endothelial responsiveness to VEGF, by measuring VEGF signaling components, nitric oxide production and mitogenesis in endothelial cell cultures exposed to elevated concentrations of glucose or AGE. We also will assess VEGF-stimulated endothelial progenitor differentiation using novel mouse embryonic stem cell lines bearing known defects in insulin signaling. Experimental therapeutics that target elements of VEGF signaling (anti-VEGF antibodies, protein kinase C-beta inhibitors) currently are undergoing clinical trials in diabetic retinopathies. The identification of previously unrecognized points of crosstalk between insulin and VEGF signaling may reveal targets of intervention to overcome resistance to insulin action in the endothelium or other insulin-sensitive tissues. This information, in turn, should facilitate the rational development of new, selective therapeutics for the vascular complications of diabetes.

描述（由申请人提供）：在美国，糖尿病折磨着估计1820万人。1型和2型糖尿病的血管并发症，包括视网膜病变、外周动脉疾病和动脉粥样硬化，是糖尿病患者发病率和死亡率的主要因素。糖尿病患者的血管内皮长期暴露于高浓度的葡萄糖和晚期糖基化终产物（AGE），导致“内皮功能障碍”，这是一种以血管通透性、反应性、血栓形成和血管修复改变为特征的病症。胰岛素和血管内皮生长因子（VEGF）各自在调节内皮细胞存活和内皮依赖性血管舒张中具有重要作用，并且这两种信号传导剂的功能在糖尿病中受损。鉴于胰岛素和VEGF激活的信号通路明显重叠，拟定的研究将检验以下假设：在糖尿病相关条件下，内皮细胞中这些通路之间的干扰串扰有助于内皮功能障碍的发展。具体而言，这些研究旨在确定VEGF刺激对内皮对胰岛素的反应性的影响，使用人内皮细胞培养物来测量胰岛素刺激的信号蛋白磷酸化、一氧化氮产生和增殖/存活。此外，我们将通过测量暴露于高浓度葡萄糖或AGE的内皮细胞培养物中的VEGF信号传导成分、一氧化氮产生和有丝分裂发生来确定与糖尿病状态或胰岛素抵抗相关的条件是否影响内皮对VEGF的反应。我们还将评估VEGF刺激的内皮祖细胞分化使用新的小鼠胚胎干细胞系轴承已知的缺陷，胰岛素信号。靶向VEGF信号传导元件的实验疗法（抗VEGF抗体、蛋白激酶C-β抑制剂）目前正在糖尿病视网膜病变中进行临床试验。胰岛素和VEGF信号传导之间先前未被识别的串扰点的鉴定可能揭示干预的靶点，以克服内皮或其他胰岛素敏感组织中对胰岛素作用的抵抗。这些信息，反过来，应该促进合理开发新的，选择性的治疗糖尿病血管并发症。