Impact of aging on calcium and electrical signaling in microvascular endothelium

衰老对微血管内皮钙和电信号传导的影响

• 批准号: 9132663
• 负责人: ERIK JOSEF BEHRINGER
• 金额: $ 24.37万
• 依托单位: LOMA LINDA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9132663
• 关键词: Abdomen; Affect; Age; Aging; Aging-Related Process; American; Animals; Arteries; Attenuated; Blood Vessels; Blood flow; Brain; Buffers; C57BL/6 Mouse; Calcium; Calcium-Activated Potassium Channel; Cardiovascular Diseases; Cell membrane; Cells; Complex; Detection; Development; Elderly; Electron Transport; Endoplasmic Reticulum; Endothelial Cells; Endothelium; Epigastric; Epigastric Arteries; Event; Gap Junctions; Generations; Goals; Health; Homeostasis; Human; Hydrogen Peroxide; Hyperemia; Image; Inner mitochondrial membrane; Ion Channel; Length; Life; Measurement; Mediating; Membrane Potentials; Metabolic; Microcirculation; Mitochondria; Mus; Nature; Nerve; Optics; Organ; Organelles; Oxidative Stress; Oxygen; Pathway interactions; Perfusion; Photometry; Physiology; Play; Potassium Channel; Preparation; Production; Quality of life; Reactive Oxygen Species; Research; Research Project Grants; Resistance; Rest; Role; Signal Pathway; Signal Transduction; Skeletal Muscle; Smooth Muscle Myocytes; Source; Superoxide Dismutase; Superoxides; Testing; Therapeutic; Tissues; Tube; Tunica Adventitia; Vascular Diseases; Vascular Endothelial Cell; Vascular Endothelium; Vasodilation; Width; age related; aged; endothelial dysfunction; healthy aging; human old age (65+); insight; male; novel; novel therapeutic intervention; prevent; response; uptake; vascular endothelial dysfunction

DESCRIPTION (provided by applicant): The number of Americans 65 years and older is expected to increase to ~20% (1 in 5) from the current ~13% (1 in 8) over the next two decades. Scientific research efforts for resolving aging physiology constitute an effective approach towards understanding, treating and preventing the development of cardiovascular disease; the number one killer of American citizens and culprit for diminishing quality of human life. Aging is associated with under-perfusion of vital tissues and organs with an integral role for vascular endothelial dysfunction. In resistance arteries that control blood flow into the microcirculation, the interaction of Ca2+ and electrical signaling pathways underlying endothelium-dependent vasodilation involves "endothelium-derived hyperpolarization" (EDH). Functional relationships support the initiation [e.g., activation of small- and intermediate-calcium-activated K+ channels (SKCa/IKCa)] and spread (via gap junctions) of hyperpolarization along and among the endothelium of network branches as a highly effective mechanism for coordinating tissue perfusion (i.e., oxygen delivery) with the metabolic demand of tissue parenchymal cells. Whereas aging is associated with oxidative stress (e.g., hydrogen peroxide production by mitochondria), there is a paucity of aging research concerned with EDH in the context of endothelial dysfunction underlying impaired tissue perfusion. Therefore, the goal of this project is to determine how mitochondrial-derived oxidative stress during aging interacts with endothelial cell Ca2+ and electrical signaling pathways that govern vasodilation and functional hyperemia. I will test the central hypothesis that the interaction of mitochondrial-derived Ca2+ and oxidative stress alter electrical signaling in the endothelium of microvascular resistance arteries. To investigate these relationships, I will employ a novel preparation of intact microvascular endothelial tubes, whereby freshly-dissected superior epigastric arteries of mouse abdominal skeletal muscle are treated to remove smooth muscle cells, adventitia, perivascular nerves and blood flow. Using intact endothelial tubes (length: ~3 mm, width: ~60 ?m) isolated from of Young (4-6 month), Intermediate (12-14 month), and Old (24- 26 month) C57BL/6 mice, I will employ simultaneous optical measurements of key signaling events (e.g., intracellular Ca2+ and H2O2 production) with intracellular recordings of membrane potential (Vm). Aim 1 will determine the mechanism by which oxidative stress alters endothelial Vm via activation of (SKCa/IKCa) with advancing age. Aim 2 will determine the role of mitochondria in Ca2+ buffering to impact (SKCa/IKCa) for ensuing hyperpolarization with advancing age. Aim 3 will determine mitochondrial production of reactive oxygen species and evaluate its role governing Vm in old age. This project will uniquely determine the role of mitochondrial handling of Ca2+ and oxidative stress signals in native intact microvascular endothelium. Results from this project will provide critical new insight towards developing therapeutic strategies for reversing endothelial dysfunction to promote tissue blood flow and sustain the quality of life during aging.

描述（由申请人提供）：在接下来的二十年中，65岁及以上的美国人的数量预计将从目前的〜13％（1分之一）增加到约20％（1中的1）。解决衰老生理学的科学研究工作构成了一种有效的理解，治疗和防止心血管疾病发展的方法。美国公民的第一杀手和罪魁祸首是降低人类生活质量的。衰老与重要组织和器官的灌注不足有关，在血管内皮功能障碍中起着不可或缺的作用。在控制血液流入微循环的电阻动脉中，Ca2+和依赖内皮依赖性血管舒张的电信号通路的相互作用涉及“内皮衍生的超极化”（EDH）。功能关系支持引发[例如，在网络分支的高极化沿网络分支的高极化的激活（SKCA/IKCA）的激活（SKCA/IKCA）]，并在网络分支的内皮中扩散（通过间隙连接），作为一种高效的机制，是一种非常有效的机制，可与氧化物递送（即，氧气递送），氧化物的递送（即，氧气递送）。尽管衰老与氧化应激有关（例如，线粒体生产过氧化氢），但在内皮功能障碍的背景下，与EDH有关的衰老研究很少。因此，该项目的目的是确定衰老过程中线粒体衍生的氧化应激如何与内皮细胞Ca2+相互作用，以及控制血管舒张和功能性充血的电信号通路。我将测试中心假设，即线粒体衍生的Ca2+与氧化应激的相互作用改变了微血管耐药动脉内皮中的电信号传导。为了调查这些关系，我将采用新颖的微血管内皮管的新准备，从而处理新鲜截止的小鼠腹部骨骼肌上胃动脉，以去除平滑肌细胞，血管周围神经和血液流动。 Using intact endothelial tubes (length: ~3 mm, width: ~60 ?m) isolated from of Young (4-6 month), Intermediate (12-14 month), and Old (24- 26 month) C57BL/6 mice, I will employ simultaneous optical measurements of key signaling events (e.g., intracellular Ca2+ and H2O2 production) with intracellular recordings of membrane potential (Vm). AIM 1将通过激活（SKCA/IKCA）随着年龄的增长来确定氧化应激通过激活（SKCA/IKCA）来改变内皮VM的机制。 AIM 2将确定线粒体在Ca2+缓冲撞击中的作用（SKCA/IKCA）在随着年龄的增长而导致超极化。 AIM 3将确定活性氧的线粒体产生，并评估其在老年中控制VM的作用。该项目将唯一确定Ca2+的线粒体处理和氧化应激信号在天然完整的微血管内皮中的作用。这个项目的结果将 为制定治疗策略提供关键的新见解，以逆转内皮功能障碍，以促进组织血流并维持衰老期间的生活质量。