KCNQ Channels in Airway Smooth Muscle Physiology and Disease

KCNQ 气道平滑肌生理学和疾病中的通道

• 批准号: 9210531
• 负责人: KENNETH L BYRON
• 金额: --
• 依托单位: EDWARD HINES JR VA HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9210531
• 关键词: Abbreviations; Acetates; Acetylcholine; Address; Affect; Agonist; Airway Resistance; Animal Model; Area; Asthma; Attenuated; Biochemical; Biological; Biophysical Process; Bronchioles; Bronchoconstriction; Bronchoconstrictor Agents; Bronchodilator Agents; Caliber; Cavia; Chronic; Clinical; Coupled; Development; Diagnosis; Disease; Drug Targeting; Electrophysiology (science); Elements; Endothelin-1; Etiology; Family; Functional disorder; Gene Family; Genetic Transcription; Histamine; Human; Inflammation Mediators; Interleukin-1 beta; Interleukin-13; Leukotriene D4; Link; Lung; Lung diseases; Measurement; Measures; Membrane; MicroRNAs; Mission; Molecular; Muscle Cells; Muscle Contraction; Muscle function; Myopathy; Obstructive Lung Diseases; Outcome; Ovalbumin; Pharmaceutical Preparations; Pharmacology; Physiology; Play; Population; Potassium; Potassium Channel; Protein Kinase C; Receptor Activation; Recruitment Activity; Regulation; Research; Research Support; Role; Slice; Stimulus; Structure of parenchyma of lung; Symptoms; Testing; Therapeutic; Tissues; Veterans; airway hyperresponsiveness; airway inflammation; airway obstruction; asthmatic; asthmatic airway; asthmatic patient; base; beta-2 Adrenergic Receptors; cohort; constriction; fundamental research; gene repression; improved; in vivo; innovation; methacholine; muscle physiology; novel; novel therapeutic intervention; novel therapeutics; patch clamp; phorbol-12-myristate; preclinical study; prevent; public health relevance; receptor; reduce symptoms; research and development; respiratory smooth muscle; response; sensitizing antigen; transcription factor; translational medicine; voltage; Abbreviations; Acetates; Acetylcholine; Address; Affect; Agonist; Airway Resistance; Animal Model; Area; Asthma; Attenuated; Biochemical; Biological; Biophysical Process; Bronchioles; Bronchoconstriction; Bronchoconstrictor Agents; Bronchodilator Agents; Caliber; Cavia; Chronic; Clinical; Coupled; Development; Diagnosis; Disease; Drug Targeting; Electrophysiology (science); Elements; Endothelin-1; Etiology; Family; Functional disorder; Gene Family; Genetic Transcription; Histamine; Human; Inflammation Mediators; Interleukin-1 beta; Interleukin-13; Leukotriene D4; Link; Lung; Lung diseases; Measurement; Measures; Membrane; MicroRNAs; Mission; Molecular; Muscle Cells; Muscle Contraction; Muscle function; Myopathy; Obstructive Lung Diseases; Outcome; Ovalbumin; Pharmaceutical Preparations; Pharmacology; Physiology; Play; Population; Potassium; Potassium Channel; Protein Kinase C; Receptor Activation; Recruitment Activity; Regulation; Research; Research Support; Role; Slice; Stimulus; Structure of parenchyma of lung; Symptoms; Testing; Therapeutic; Tissues; Veterans; airway hyperresponsiveness; airway inflammation; airway obstruction; asthmatic; asthmatic airway; asthmatic patient; base; beta-2 Adrenergic Receptors; cohort; constriction; fundamental research; gene repression; improved; in vivo; innovation; methacholine; muscle physiology; novel; novel therapeutic intervention; novel therapeutics; patch clamp; phorbol-12-myristate; preclinical study; prevent; public health relevance; receptor; reduce symptoms; research and development; respiratory smooth muscle; response; sensitizing antigen; transcription factor; translational medicine; voltage

 DESCRIPTION (provided by applicant) Asthma is a chronic respiratory disease characterized by reversible airway obstruction and hyper- responsiveness of the airways to bronchoconstrictor stimuli. Veterans represent a large cohort of asthma sufferers, many of whom do not achieve relief of symptoms with available therapies. Reversible airway obstruction in asthma results primarily from hypercontraction of airway smooth muscle cells (ASMCs) in the bronchioles of the lung. The mechanisms involved in ASMC hypercontraction are poorly characterized but likely involve exaggerated bronchoconstrictor responses to Gq/11-coupled receptor agonists, which include acetylcholine, histamine, endothelin-1, and leukotriene D4. Increased Ca2+ influx via voltage-sensitive Ca2+ channels (VSCCs) contributes to the exaggerated bronchoconstrictor responses. The voltage change required to activate VSCCs can be provided by suppressing potassium (K+) channel activity. We recently discovered that KCNQ (Kv7 family) K+ channels are expressed and active in freshly isolated bronchiolar myocytes and that their activity is suppressed by multiple bronchoconstrictor agonists. We further demonstrated that Kv7 current suppression is sufficient to induce airway constriction and that pharmacological Kv7 channel activators significantly attenuate airway constriction in precision-cut human lung slices. Based on these discoveries, we propose to examine the hypothesis that bronchoconstrictor agonists suppress the activity of Kv7 family K+ channels in ASMCs to induce membrane depolarization and ASMC hypercontraction. Furthermore, we will explore two additional hypotheses that have important clinical/translational relevance for our understanding and treatment of asthma. We hypothesize that inflammatory mediators alter Kv7 channel expression, which plays a role in the etiology of airway hyperresponsiveness in asthma. Furthermore, because Kv7 channels are established drug targets, we hypothesize that clinically used Kv7 channel activators can be used as a monotherapy or they may be combined with other therapies to prevent or reduce excessive airway constriction in asthma. To address our hypotheses, three Specific Aims are proposed. Aim 1) Elucidate the mechanisms by which Gq/11-coupled receptor agonists regulate Kv7 currents in ASMCs. The role of protein kinase C will be determined by using a variety of biochemical, pharmacological, and molecular biological approaches in combination with patch clamp electrophysiology and measurements of airway smooth muscle function in human and guinea pig ASMCs and lung tissues. Aim 2) Test two novel hypotheses linking airway inflammation to suppression of Kv7 channel expression in ASMCs and increased sensitivity to bronchoconstrictor stimuli. Hypothesis 1: inflammatory mediators, such as IL-13 and IL-1β, upregulate repressor element 1 silencing transcription factor (REST), which then inhibits transcription of KCNQ genes in ASMCs. Hypothesis 2: micro RNA 146a (miR146a), which is also increased in response to inflammatory mediators, induces post- transcriptional repression of Kv7.5 expression in ASMCs. REST and miR146a expression will be measured/altered in ASMCs from normal and asthmatic human and guinea pig lungs to determine their relationship to altered expression/function of Kv7 channels and the link to airway hyperresponsiveness. Aim 3) Evaluate the therapeutic benefits of Kv7 channel activators, alone or combined with β2-adrenergic receptor agonists, on airway function in vivo in normal and antigen-sensitized guinea pigs. Our proposed studies are significant because they will elucidate previously unknown mechanisms for ASMC hypercontraction and identify a new therapeutic strategy to provide better relief of airway hyperresponsiveness in asthma patients. This outcome would directly benefit thousands of veterans and civilians who suffer from asthma or other airway diseases.

 描述（由申请人提供） 哮喘是一种慢性呼吸道疾病，其特征是气道反对反对和气道对支气管收缩刺激的反应性。退伍军人代表着大量的哮喘患者，其中许多人无法通过可用的疗法缓解症状。哮喘的可逆气道异常是由于肺部支气管中气道平滑肌细胞（ASMC）的过度收缩而导致的。 ASMC超收集涉及的机制的特征很差，但可能涉及对GQ/11偶联受体激动剂的夸张的支气管收缩反应，其中包括乙酰胆碱，组胺，内皮素-1和白细胞烯D4。通过电压敏感的Ca2+通道（VSCC）增加了Ca2+的影响，这有助于夸张的支气管收缩反应。激活VSCC所需的电压变化可以通过抑制钾（K+）通道活动来提供。我们最近发现，KCNQ（KV7家族）K+通道在新鲜分离的支气管肌细胞中表达并活跃，并且它们的活性被多种支气管收缩激动剂抑制。我们进一步证明，KV7电流抑制足以诱导气道收缩，并且药物KV7通道激活剂在精确切割的人肺切片中显着减弱了气道的收缩。基于这些发现，我们建议检验以下假设：支气管收缩激动剂抑制了ASMC中KV7家族K+通道的活性以诱导膜沉积和ASMC超收集。此外，我们将探索两个具有重要临床/翻译相关性的其他假设，以理解和治疗哮喘。我们假设炎症介质会改变KV7通道的表达，这在哮喘中气道高反应性的病因中起作用。此外，由于KV7通道是建立的药物靶标，因此我们假设临床使用的KV7通道激活剂可以用作单一疗法，或者可以与其他疗法结合使用，以防止或减少哮喘中过量的气道收缩。为了解决我们的假设，提出了三个具体目标。目的1）阐明GQ/11耦合受体激动剂调节KV7的机制将通过使用各种生化，药物和分子生物学方法来确定蛋白质激酶C的作用，结合贴片夹夹夹的电物质学以及在人类和侏儒犬Asmcsmcsmcsmcsmcc and Gunway ungune and Gunway ungung assmccy和Lunk and ungngs and and ungnct and ungngs and ungngs and ungngs and ungngs and ungngs和l， Aim 2) Test two novel hypotheses linking airway injection to suppression of Kv7 channel expression in ASMCs and increased sensitivity to bronchoconstrictor Hypothesis 1: inflammatory mediators, such as IL-13 and IL-1β, upregulated replicator element 1 silencing transcription factor (REST), which then inhibits transcription of KCNQ genes in ASMCs.假设2：微RNA 146a（miR146a）也因炎症介质而增加，它诱导了ASMC中KV7.5表达的转录后表示。在正常和哮喘的人和豚鼠肺的ASMC中，将测量/改变REST和MIR146A表达，以确定它们与KV7通道的改变/功能的关系以及与气道高反应性的联系。 AIM 3）单独评估KV7通道激活剂的治疗益处，或与β2-肾上腺素受体激动剂相结合，在正常和抗原敏感的豚鼠中的气道功能。我们提出的研究之所以重要，是因为它们将阐明以前未知的ASMC超收集机制，并确定一种新的理论策略，以更好地缓解哮喘患者的气道高反应性。这种结果将直接使成千上万患有哮喘或其他气道疾病的退伍军人和平民受益。