Neuro-immune mechanisms in carotid body chemoreceptor response to chronic hypoxia

颈动脉体化学感受器对慢性缺氧反应的神经免疫机制

基本信息

批准号：
7580345
负责人：
SALVATORE J FIDONE
金额：
$ 37.63万
依托单位：
UNIVERSITY OF UTAH
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-12-15 至 2012-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7580345
关键词：
Acids Afferent Neurons Animal Model Anti-Inflammatory Agents Anti-inflammatory Area Attention Blood CD8-Positive T-Lymphocytes Carotid Body Cells Chemoreceptors Chemotactic Factors Chronic Chronic Obstructive Airway Disease Clinical Development E-Selectin Endothelin Endothelin Receptor Antagonist Exposure to Ganglia Gene Deletion Gene Expression Genes Heart failure Human Hypersensitivity Hypoxia Imaging Techniques Immune Immune system Immunofluorescence Immunologic Inflammation Inflammatory Inflammatory Response Injury Interleukin-6 Interleukins Investigation Ion Channel Mediating Modality Molecular Monocyte Chemoattractant Protein-1 Monocyte Chemoattractant Proteins Myxoid cyst Nerve Fibers Neurons Organ Oxygen Pathway interactions Peptides Peripheral Pharmaceutical Preparations Pharmacology Phenotype Preparation Production Property Regulation Research Role Sensory Signal Transduction Spinal Ganglia Stimulus Text Time Tissues Transducers Tumor Necrosis Factor-alpha Tumor Necrosis Factors Type I Epithelial Receptor Cell Vascular Cell Adhesion Molecule-1 Vasoconstrictor Agents cell type chronic pain cytokine cytotoxic extracellular inflammatory neuropathic pain intercellular cell adhesion molecule macrophage neurochemistry neurophysiology neutrophil novel programs public health relevance research study response sensor transcription factor

项目摘要

DESCRIPTION (provided by applicant): Experiments in recent years have revealed labile electrophysiological and neurochemical phenotypes in primary afferent neurons exposed to specific (chronic) stimulus conditions associated with the development of chronic pain. These studies collectively demonstrate that the mechanisms responsible for functional plasticity are primarily mediated by novel neuro-immune interactions involving circulating and resident immune cells and their secretory products, which together induce hyperexcitability in the primary sensory neurons. In another peripheral sensory modality, namely the arterial chemoreceptors, sustained stimulation in the form of chronic hypoxia (CH) elicits increased chemoafferent excitability from the mammalian carotid body. Previous studies which focused on functional changes in oxygen-sensitive type I cells in this organ have failed to fully elucidate the molecular and cellular mechanisms which initiate and control this adaptive response. It is noteworthy that the possible involvement of neuro-immune mechanisms in increased chemoafferent sensitivity has never been investigated. Our proposed research program assesses immune cell and cytokine involvement in the chemoafferent pathway as a mechanism for chemosensory adaptation. Experiments will investigate 1), CH- induced immune cell invasion and cytokine production in the chemoafferent pathway; 2), the relationship between immune cell activity and increased chemosensitivity; 3), the role of oxygen-sensitive type I cells in initiating an inflammatory response in carotid body; and, 4), inflammation-induced phenotypic changes in type I cells and primary chemoafferent neurons which facilitate hyperexcitability. Preliminary results indicate a unique role for the immune system in regulating the chemo-adaptive response of the carotid body to physiologically relevant levels of hypoxia. These studies are expected to have implications for common clinical conditions such as chronic obstructive pulmonary disease (COPD), and chronic heart failure (CHF). PUBLIC HEALTH RELEVANCE: The research demonstrates that chronically low levels of arterial blood oxygen induce an inflammatory response in oxygen-sensitive tissue of the carotid body, the principal sensor of dissolved oxygen in blood. Furthermore, the inflammatory condition is shown to induce hypersensitivity in the carotid body, so that subsequent exposures to low levels of oxygen elicit an abnormally large response. This adaptive adjustment is relevant to common clinical conditions, such as chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD), in which blood oxygen levels decrease.

描述（由申请人提供）：近年来的实验揭示了暴露于与慢性疼痛的发展相关的特定（慢性）刺激条件的初级传入神经元中不稳定的电生理学和神经化学表型。这些研究共同证明，负责功能可塑性的机制主要是由涉及循环和常驻免疫细胞及其分泌产物的新型神经免疫相互作用介导的，这些相互作用共同诱导初级感觉神经元的过度兴奋。在另一种外周感觉模式中，即动脉化学感受器，慢性缺氧（CH）形式的持续刺激会引起哺乳动物颈动脉体的化学传入兴奋性增加。先前的研究重点关注该器官中氧敏感的 I 型细胞的功能变化，但未能完全阐明启动和控制这种适应性反应的分子和细胞机制。值得注意的是，神经免疫机制可能参与化学传入敏感性的增加从未被研究过。我们提出的研究计划评估化学传入途径中免疫细胞和细胞因子的参与，作为化学感应适应的机制。实验将研究1）、CH诱导的化学传入途径中的免疫细胞侵袭和细胞因子产生； 2）、免疫细胞活性与化疗敏感性增加的关系； 3）、氧敏感I型细胞在引发颈动脉体炎症反应中的作用； 4）炎症诱导的 I 型细胞和初级化学传入神经元表型变化，促进过度兴奋。初步结果表明，免疫系统在调节颈动脉体对生理相关缺氧水平的化学适应性反应方面发挥着独特的作用。这些研究预计将对慢性阻塞性肺病（COPD）和慢性心力衰竭（CHF）等常见临床病症产生影响。公共健康相关性：研究表明，长期低水平的动脉血氧会引起颈动脉体氧敏感组织的炎症反应，颈动脉体是血液中溶解氧的主要传感器。此外，炎症会引起颈动脉体过敏，因此随后暴露于低水平的氧气会引起异常大的反应。这种适应性调整与常见的临床病症相关，例如血氧水平下降的慢性心力衰竭（CHF）和慢性阻塞性肺疾病（COPD）。