Mechanisms Underlying Carotid Body-dependent Sympathetic Activation by Chronic Intermittent Hypoxia

慢性间歇性缺氧引起颈动脉体依赖性交感神经激活的机制

• 批准号: 10409552
• 负责人: Nanduri R Prabhakar
• 金额: $ 45.36万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-15 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10409552
• 关键词: Adenylate Cyclase; Affect; Autonomic Dysfunction; Biochemical; Biological; Biological Assay; Blood Pressure; Carotid Body; Cell membrane; Central Sleep Apnea; Chronic; Complex; Cyclic AMP; Data; Development; Exhibits; Exposure to; G-Protein-Coupled Receptors; Gases; Gene Deletion; Genetically Engineered Mouse; Glomus Cell; Goals; Hyperactivity; Hypoxia; Joints; Knockout Mice; Lead; Link; Mediating; Molecular; Mus; Nerve; Odorant Receptors; Patients; Peripheral; Persons; Physiological; Publications; Rattus; Receptor Activation; Receptor Signaling; Reflex action; Reporting; Respiratory Disease; Rodent; Rodent Model; Role; Signal Transduction; Sleep Apnea Syndromes; Techniques; Testing; Therapeutic; comorbidity; conditional knockout; cyclic-nucleotide gated ion channels; experience; experimental study; innovation; interest; member; neuromechanism; novel; olfactory receptor; response; therapeutic evaluation

Project Summary- Project 1 Sleep apnea (SA) is a highly prevalent respiratory disease affecting several million people in the USA alone. Chronic Intermittent Hypoxia (CIH) is a hallmark manifestation of SA. Patients with SA, and rodents exposed to CIH exhibit elevated sympathetic nerve activity, which has been implicated in causing autonomic co- morbidities. The overall goal of the Project 1 is to delineate peripheral neural mechanisms underlying CIH- induced sympathetic activation and assess its impact on blood pressure. A heightened carotid body (CB) chemo reflex has been implicated as a major driver of CIH-induced sympathetic activation and gaseous messenger H2S mediates CB hyperactivity by CIH. Project 1 seeks to determine how H2S causes the CB activation by CIH. We test the hypothesis that H2S acting on olfactory receptor 78 (Olfr78) in glomus cells initiates a complex signaling cascade, involving a cAMP-dependent increase in [Ca2+]I leading to CB hyperactivity by CIH. We test this possibility using a combination of physiological, biochemical and molecular biological approaches on rats and mice exposed to CIH as well as in mice exhibiting spontaneous sleep apnea, and primary cultures of CB glomus cells. Studies in AIM 1 assess the role of Olfr78 in CB activation by CIH. AIM 2 determines whether CB activation by CIH requires cAMP activation by Olfr78 by H2S. AIM 3 determines how cAMP leads to CB activation by CIH. Experiments in AIM 4, determines the importance of CB H2S-Olfr78 signaling in CB excitation and sympathetic activation in mice exhibiting sleep apnea. Major conceptual and technical innovations include: a) H2S acting through odorant receptors mediates CIH-evoked CB excitation with profound consequences on autonomic functions is conceptually novel and has not been explored beyond the preliminary data presented in this application, b) assessing the significance of findings from experimental rodent model of CIH in mice exhibiting natural sleep apnea; and c) development of novel techniques to generate CB specific deletion of genes of interest. Project 1 has tight thematic linkages to Projects 2, 3, and 4 and utilizes Core B facilities for: a) exposing rats and mice to CIH, b) obtaining genetically engineered mice, c) targeted deletion of genes, and d) biochemical and molecular biological assays. Members of the investigative team have long-standing experience and expertise with the proposed approaches and a track record of working together as evidenced by joint publications. Successful completion of Project 1 is anticipated to establish a novel role for Olfr78 in mediating biological actions of H2S, which might lead to therapeutic strategies targeting of H2S-Olfr78 signaling to block CB reflex-dependent sympathetic hyperactivity.

项目摘要-项目1 睡眠呼吸暂停(SA)是一种高度流行的呼吸道疾病，仅在美国就有数百万人受到影响。 慢性间歇性低氧(CIH)是SA的一个显著表现。SA患者和暴露的啮齿动物 表现出交感神经活性升高，这与导致自主神经协同 病态。项目1的总体目标是描述脑出血的外周神经机制。 诱导交感神经激活并评估其对血压的影响。颈动脉小体(CB)增厚 化学反射被认为是CIH诱导交感神经激活和气体刺激的主要驱动因素 信使H_2S通过CIH介导脐带血过度活动。项目1试图确定硫化氢是如何导致CB的 由CIH激活。我们验证了硫化氢作用于球体细胞中嗅觉受体78(Olfr78)的假设 启动复杂的信号级联反应，包括cAMP依赖的[Ca~(2+)]i升高导致CB CIH引起的多动症。我们使用生理、生化和分子相结合的方法来测试这种可能性 对接触CIH的大鼠和小鼠以及表现出自然睡眠的小鼠的生物学方法 呼吸暂停和CB球蛋白细胞的原代培养。AIM 1的研究通过以下方式评估Olfr78在CB激活中的作用 啊哈。目的2确定CIH激活CB是否需要Olfr78用硫化氢激活cAMP。目标3 决定cAMP如何导致CIH激活CB。AIM 4中的实验，决定了CB的重要性 睡眠呼吸暂停小鼠CB兴奋和交感神经激活中的H_2S-Olfr78信号。主修 概念和技术创新包括：a)通过气味受体作用的硫化氢介导了CIH诱发的 CB兴奋对自主神经功能有深远的影响在概念上是新的，并没有 在本申请中提供的初步数据之外进行了探索，b)评估调查结果的意义 来自表现出自然睡眠呼吸暂停的小鼠的实验性脑出血模型；以及c)新的 产生感兴趣基因的CB特异性缺失的技术。项目1与以下主题有密切联系 项目2、3和4，并利用核心B设施：a)将大鼠和小鼠暴露于CIH，b)通过基因获得 基因工程小鼠，c)有针对性的基因删除，d)生化和分子生物学检测。成员 的调查组成员对拟议的方法具有长期的经验和专业知识， 联合出版物证明了共同工作的记录。成功完成项目1是 预计Olfr78将在调节硫化氢的生物作用方面发挥新的作用，这可能导致 靶向H_2S-Olfr78信号阻断CB反射依赖交感神经的治疗策略 多动症。