How does DHEA improve diabetic microvascular dysfunction

DHEA如何改善糖尿病微血管功能障碍

• 批准号: 6719388
• 负责人: JOSEPH S DILLON
• 金额: $ 14.75万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2004-05-20
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6719388
• 关键词: affinity chromatography; cell line; cell surface receptors; corticosteroid receptors; dehydroepiandrosterone; diabetes mellitus; diabetic angiopathy; drug screening /evaluation; microarray technology; protein structure function; receptor expression; transfection; vascular endothelium

DESCRIPTION (provided by applicant): Long-term complications of diabetes have a devastating impact on the lives of millions of Americans. While microvascular dysfunction plays a key role in the development of complications, the pathophysiology of microvascular changes in diabetes is poorly understood. The aging-regulated, adrenal steroid hormone and nutritional supplement, dehydroepiandrosterone (DHEA), improves microvascular dysfunction in diabetes. The molecular mechanism of this action is unknown. Our long-term objective is to decrease the morbidity of diabetic complications, by developing novel drugs that target diabetic vascular dysfunction. Our short-term goal is to define the cellular mechanism for the vascular action of DHEA. We hypothesize that DHEA affects vascular function by activating an endothelial receptor. This hypothesis is based on our discovery of a vascular endothelial, G-protein coupled, DHEA-specific receptor, linked to nitric oxide production. Isolating this receptor is a crucial first step in testing our hypothesis. We plan to achieve the following specific aims: 1 Isolate, sequence and clone the vascular endothelial DHEA receptor. Evaluate functional aspects of the cloned receptor in transiently transfected COS-7 cells. Our research design involves two strategies:(1) affinity chromatographic purification and isolation of a DHEA binding protein from solubilized bovine aortic plasma membranes and (2) cDNA microarray to identify candidate orphan G-protein coupled receptors, expressed on vascular endothelial cells. The candidate cDNAs will be tested in cellular expression and DHEA binding assays. We expect to show definitively how DHEA interacts with vascular endothelial cells and, for the first time, begin to provide a molecular basis for some of the widespread health effects claimed for DHEA. The result will allow us to determine the role of the receptor-DHEA interaction in vascular function, development, aging and disease. We will be able to screen for high potency receptor activating molecules to evaluate therapeutically in human vascular disease, including diabetic microvascular dysfunction. The results will facilitate the study of signaling pathways to important vascular functions such as nitric oxide production, cell proliferation and apoptosis. Thus, the successful completion of our project will advance our long-term goal of developing novel therapeutic vasoactive agents, to decrease the morbidity related to diabetic vascular dysfunction.

描述（由申请人提供）：糖尿病的长期并发症对数百万美国人的生活造成毁灭性影响。虽然微血管功能障碍在并发症的发生中起着关键作用，但人们对糖尿病微血管变化的病理生理学知之甚少。脱氢表雄酮 (DHEA) 是一种具有衰老调节作用的肾上腺类固醇激素和营养补充剂，可改善糖尿病患者的微血管功能障碍。该作用的分子机制尚不清楚。我们的长期目标是通过开发针对糖尿病血管功能障碍的新药物来降低糖尿病并发症的发病率。我们的短期目标是确定 DHEA 血管作用的细胞机制。我们假设 DHEA 通过激活内皮受体影响血管功能。这一假设基于我们对血管内皮 G 蛋白偶联 DHEA 特异性受体的发现，该受体与一氧化氮的产生有关。分离这种受体是检验我们的假设的关键的第一步。我们计划实现以下具体目标： 1 分离、测序和克隆血管内皮DHEA受体。 评估瞬时转染 COS-7 细胞中克隆受体的功能。 我们的研究设计涉及两种策略：(1) 从溶解的牛主动脉质膜中亲和层析纯化和分离 DHEA 结合蛋白，以及 (2) cDNA 微阵列以鉴定血管内皮细胞上表达的候选孤儿 G 蛋白偶联受体。候选 cDNA 将在细胞表达和 DHEA 结合测定中进行测试。我们期望明确展示 DHEA 如何与血管内皮细胞相互作用，并首次开始为 DHEA 声称的一些广泛的健康影响提供分子基础。该结果将使我们能够确定受体-DHEA 相互作用在血管功能、发育、衰老和疾病中的作用。我们将能够筛选高效受体激活分子，以评估人类血管疾病（包括糖尿病微血管功能障碍）的治疗效果。这些结果将有助于研究重要血管功能的信号通路，例如一氧化氮的产生、细胞增殖和凋亡。因此，我们项目的成功完成将推进我们开发新型治疗性血管活性药物的长期目标，以降低与糖尿病血管功能障碍相关的发病率。