Nicotine, Airway Smooth Muscle and Asthma

尼古丁、气道平滑肌和哮喘

• 批准号: 9763806
• 负责人: Christina Maria Pabelick
• 金额: $ 51万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-05 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9763806
• 关键词: Acute; Adult; Affect; Agonist; Airway Resistance; Allergens; Asthma; Bathing; Biochemical; Biology; Cell Proliferation; Cell membrane; Cells; Cholinergic Receptors; Chronic; Cytokine Signaling; Data; Devices; Electronic cigarette; Electrophysiology (science); Elements; Epithelium; Exposure to; Extrinsic asthma; Genes; Goals; Grant; Human; In Vitro; Inflammation; Inflammatory; Interleukin-13; Interleukin-6; Knockout Mice; Lung; MAP Kinase Gene; Mediating; Metabolism; Mitochondria; Molecular Chaperones; Mus; Muscarinic Acetylcholine Receptor; Muscle; Neurons; Nicotine; Nicotinic Receptors; OPA1 gene; Organ; PI3 gene; Pathway interactions; Regulation; Respiration; Role; Sampling; Signal Transduction; Small Interfering RNA; Smoking; Smoking History; Smooth Muscle; Smooth Muscle Myocytes; Structure; System; TNF gene; Testing; Toxic effect; Traction; airway hyperresponsiveness; alpha-bungarotoxin receptor; asthma model; asthmatic; asthmatic airway; asthmatic airway smooth muscle; clinically relevant; clinically significant; cytokine; endoplasmic reticulum stress; inhibitor/antagonist; methacholine; mouse allergen; mouse model; nicotine exposure; nicotine inhalation; nicotine use; novel; patch clamp; protein metabolism; respiratory smooth muscle; response; sex; therapeutic target

ABSTRACT While e-cigarettes are advertised as safer alternatives to smoking for asthmatics, there is increasing evidence of their pulmonary toxicity, necessitating better understanding of airway nicotine biology: a clinically-relevant unmet need, and major goal of this grant. In asthma, inflammation enhances airway smooth muscle (ASM) Ca2+ ([Ca2+]cyt) and contractility (airway hyperreactivity; AHR), along with remodeling involving ASM proliferation. Given that inhaled nicotine can directly influence ASM, nicotine effects on asthmatic ASM are critical, but little is known about nicotinic receptor (nAChR) expression, its role in human ASM, or in asthma. Preliminary data in human ASM show functional α7 nAChRs that A) increase with inflammation and asthma, B) enhance ASM [Ca2+]cyt/contractility; C) enhance ER stress and mitochondrial fission, and respiration, and D) activate pro-proliferative pathways. Such effects are observed in a mixed-allergen mouse model of asthma exposed to acute or chronic inhaled nicotine, but blunted by α7 inhibition and in α7 KO mice. Thus, our hypothesis is that nicotine acts via ASM α7 to promote AHR and remodeling in asthma. Our Aims are: Aim 1: : In human ASM, determine mechanisms of α7 expression and regulation in inflammation and asthma. Aim 2: In human ASM of non-asthmatics vs. asthmatics, to determine mechanisms by which α7 contributes to nicotine enhancement of [Ca2+]cyt and contractility in the context of AHR. Aim 3: In human ASM of non-asthmatics vs. asthmatics, to determine mechanisms by which α7 contributes to nicotine enhancement of cell proliferation. Aim 4: In a mouse model of allergic asthma, to determine the role of α7 in effects of inhaled nicotine on AHR and remodeling. Studies use adult human ASM of non-asthmatics vs. mild-moderate asthmatics exposed to cytokines relevant to ASM and to asthma (TNFα, IL-6, IL-13), with/without nicotine. Aim 1 explores expression and localization of α7 nAChR, regulatory chaperones, and mechanisms by which α7 is increased in inflammation/asthma (e.g. MAPKs, PI3/Akt, NFκB, Stats). α7 functionality as a channel is tested using electrophysiology. Aim 2 explores acute vs. chronic nicotine effects on [Ca2+]cyt regulation (influx, SR Ca2+ release) and contractility (traction force, organ bath). Aim 3 explores nicotine effects on ASM proliferation, and the roles of ER stress, mitochondrial fission (Drp1, Fis1) vs. fusion (Mfn1/2, Opa1) and respiration (3a), and of cytokine-associated proliferative pathways (3b). In these Aims, role of α7 is determined using broad vs. subunit- specific agonists, antagonists or siRNAs. In vitro results are integrated in Aim 4 using the adult mouse model of asthma with/without acute vs. chronic inhaled nicotine. Alleviating effects of α7 inhibitor (MG624) and effects of α7 KO in smooth muscle are tested. Studies assess airway reactivity, remodeling, and ASM biochemical changes. Clinical significance lies in identifying ASM α7 as a novel target for alleviating AHR and remodeling of asthma as well as with nicotine.

抽象的 虽然电子烟被宣传为哮喘患者更安全的吸烟替代品，但越来越多的证据表明 其肺毒性，需要更好地了解气道尼古丁生物学：临床相关 未满足的需求，以及本次资助的主要目标，在哮喘中，炎症可增强气道平滑肌（ASM）。 Ca2+ ([Ca2+]cyt) 和收缩性（气道高反应性；AHR），以及涉及 ASM 的重塑 鉴于吸入尼古丁可以直接影响 ASM，因此尼古丁对哮喘 ASM 的影响是显着的。 烟碱受体 (nAChR) 的表达及其在人类 ASM 或哮喘中的作用至关重要，但人们知之甚少。 人类 ASM 的初步数据显示，功能性 α7 nAChR 会 A) 随炎症和哮喘而增加， B) 增强 ASM [Ca2+]cyt/收缩性；C) 增强 ER 应激和线粒体裂变以及呼吸作用； D) 激活促增殖途径，在哮喘混合过敏原小鼠模型中观察到这种作用。 暴露于急性或慢性吸入尼古丁，但通过 α7 抑制而减弱，并且在 α7 KO 小鼠中。 假设尼古丁通过 ASM α7 促进 AHR 和哮喘重塑。 目标 1：：在人类 ASM 中，确定炎症和哮喘中 α7 表达和调节的机制。 目标 2：在非哮喘患者与哮喘患者的人类 ASM 中，确定 α7 促进的机制 尼古丁增强 AHR 背景下的 [Ca2+]cyt 和收缩力 目标 3：在非哮喘患者的人类 ASM 中。 与哮喘患者相比，以确定 α7 促进尼古丁增强细胞增殖的机制。 目标 4：在过敏性哮喘小鼠模型中，确定 α7 在吸入尼古丁对 AHR 影响中的作用 研究使用了非哮喘患者与轻度至中度哮喘患者的 ASM。 与 ASM 和哮喘相关的细胞因子（TNFα、IL-6、IL-13），含/不含尼古丁 目标 1 探讨表达。 α7 nAChR 的定位、调节分子伴侣以及 α7 增加的机制 炎症/哮喘（例如 MAPK、PI3/Akt、NFκB、Stats）作为通道进行测试。 目标 2 探讨尼古丁对 [Ca2+] 细胞色素调节的急性与慢性影响（流入、SR Ca2+） 目标 3 探索尼古丁对 ASM 增殖的影响，以及 内质网应激、线粒体裂变（Drp1、Fis1）与融合（Mfn1/2、Opa1）和呼吸（3a）的作用，以及 在这些目标中，α7 的作用是通过广泛与亚基来确定的。 使用成年小鼠模型将特定激动剂、拮抗剂或 siRNA 的体外结果整合到 Aim 4 中。 哮喘有/没有急性与慢性吸入尼古丁的缓解作用和α7抑制剂（MG624）的作用。 测试了平滑肌中的 α7 KO，研究评估了气道反应性、重塑和 ASM 生化。 临床意义在于确定 ASM α7 作为缓解 AHR 和重塑的新靶点。 哮喘以及尼古丁。