Endothelial exocytosis and the vascular dysfunction of aging

内皮胞吐作用与衰老的血管功能障碍

• 批准号: 7878227
• 负责人: NICHOLAS A FLAVAHAN
• 金额: $ 20.5万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-12 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7878227
• 关键词: Affect; Age; Aging; Animals; Arteries; Blood Vessels; Cardiovascular system; Cells; Cytoplasmic Granules; Dilator; Disease; Elderly; Endothelial Cells; Endothelin; Endothelin-1; Endothelium; Exocytosis; Functional disorder; Generations; Inbred F344 Rats; Inflammatory; Ischemia; Laser Scanning Confocal Microscopy; Mediating; Mediator of activation protein; Microcirculation; Modern Medicine; Nitric Oxide; Organ; Pathology; Peptides; Physicians; Play; Pre-Clinical Model; Process; Production; Published Comment; Rattus; Regulation of Exocytosis; Reperfusion Therapy; Reporting; Research; Role; Signal Transduction; Splanchnic Circulation; Staining method; Stains; Stress; Testing; Thrombin; Vasomotor; Weibel-Palade Bodies; age effect; aged; design; inhibitor/antagonist; novel; novel strategies; oxidant stress; public health relevance; receptor; research study; response; von Willebrand Factor

DESCRIPTION (provided by applicant): The aging endothelium is characterized by reduced activity of the endothelial dilator NO, increased production of ROS and oxidant stress, and increased inflammatory and thrombotic activity. Endothelial storage granules, including Weibel-Palade Bodies (WPBs) contain numerous mediators that play important roles in regulating vasomotor, thrombotic and inflammatory processes, and can be rapidly released by stimulated exocytosis. It is likely that exocytosis and release of these endothelial granules play an important role in the vascular pathology associated with aging. However, no previous studies have directly assessed the effects of aging on this fundamental mechanism. In novel preliminary results, we demonstrate that native endothelium of aging blood vessels have increased ability to generate and release pathophysiological mediators (including endothelin-1) during stimulated exocytosis. Our overall hypothesis is that increased release and generation of endothelial mediators by stimulated exocytosis contributes to vascular dysfunction in aging. We hope that by increasing our understanding of how aging affects this fundamental mechanism, it may provide novel approaches to treat diseases associated with aging. We will test our hypotheses on native endothelium of young and aging blood vessels, using the Fischer rat preclinical model of aging. Three specific aims are proposed to: AIM 1: DETERMINE THE INFLUENCE OF AGING ON THE GENERATION AND EXOCYTOSIS OF ENDOTHELIN-1 FROM ENDOTHELIUM. These experiments will focus on evaluating the increased ability of aging endothelium to generate endothelin-1 (ET-1) during exocytosis. Experiments will investigate the expression, processing and exocytotic release of ET-1 from the endothelium of young and aging blood vessels. AIM 2: DETERMINE THE ROLE OF NITRIC OXIDE IN REGULATING ENDOTHELIAL WPB EXOCYTOSIS IN AGING BLOOD VESSELS. These experiments will investigate the apparent decreased inhibitory effect of NO signaling in regulating exocytosis in aging endothelium. Experiments will focus on the mechanisms underlying NO regulation of exocytosis. AIM 3: EVALUATE THE PATHOLOGICAL ROLE OF ENDOTHELIAL EXOCYTOSIS IN THE AGING MICROCIRCULATION. These experiments will evaluate the potential pathophysiological role of dysregulated endothelial exocytosis in aging. This will be achieved by investigating the role of exocytosis in the microvascular responses of young and aging animals to ischemia- reperfusion of the mesenteric circulation. PUBLIC HEALTH RELEVANCE: The Johns Hopkins physician and icon of modern medicine, Sir William Osler (1849-1919) commented that we are only as old as our arteries. We now know that we may only be as old as our endothelium. This project proposes to analyze the influence of aging on a fundamental mechanism of endothelial function (stimulated exocytosis), and to evaluate its role in stress- induced microvascular dysfunction associated with aging organs.

描述（由申请人提供）：衰老的内皮的特征是内皮扩张剂NO的活性降低，ROS和氧化剂应激的产生增加以及炎症和血小板活性的增加。内皮储存颗粒，包括微花甲状腺体（WPB），其中包含许多介质，这些介体在调节血管舒缩，血栓形成和炎症过程中起着重要作用，并且可以通过刺激的胞胞菌病快速释放。这些内皮颗粒的胞吐作用和释放可能在与衰老相关的血管病理学中起重要作用。但是，以前没有直接评估衰老对这种基本机制的影响。在新的初步结果中，我们证明了衰老血管的天然内皮具有增加和释放病理生理介质（包括内皮素-1）的能力，在刺激的胞吐作用过程中。我们的总体假设是，通过刺激的胞吐作用增加了内皮介质的释放和产生，导致衰老的血管功能障碍。我们希望，通过对衰老如何影响这种基本机制的理解，它可以提供治疗与衰老相关的疾病的新方法。我们将使用Fischer大鼠临床前的衰老模型来检验对年轻和衰老血管天然内皮的假设。提出了三个特定的目的：目标1：确定衰老对内皮1的衰老对内皮素-1产生和胞吐作用的影响。这些实验将集中于评估衰老内皮在胞吐作用期间产生内皮素-1（ET-1）的能力的提高。实验将研究ET-1从年轻和衰老血管内皮中ET-1的表达，加工和胞吐释放。 AIM 2：确定一氧化氮在调节衰老血管中内皮WPB胞吐作用中的作用。这些实验将研究NO信号传导在调节衰老内皮细胞增多症中的明显降低的抑制作用。实验将集中在不调节胞吐作用的基础机制上。 AIM 3：评估内皮胞吐作用在老化微循环中的病理作用。这些实验将评估失调内皮胞吐作用在衰老中的潜在病理生理作用。这将通过研究胞吐作用在年轻动物和衰老动物对肠系膜循环的缺血再灌注的微血管反应中的作用来实现。 公共卫生相关性：约翰·霍普金斯（Johns Hopkins）的医生和现代医学的偶像，威廉·奥斯勒爵士（William Osler，1849- 1919年）评论说，我们只和动脉一样古老。现在，我们知道我们可能只像我们的内皮一样古老。该项目建议分析衰老对内皮功能基本机制（刺激的胞吐作用）的影响，并评估其在与衰老器官相关的胁迫诱导的微血管功能障碍中的作用。