BETA-ADRENERGIC RECEPTOR REGULATION IN AIRWAY EPITHELIUM

β-肾上腺素能受体(β-AR)对气管、支气管壁的刺激 上皮细胞引起多种影响防御的细胞反应 这可能会改变呼吸道感染的强度 呼吸道的炎症反应。β-肾上腺素能激动剂作用于 气管、支气管上皮影响盐分和水的交换。 气道壁、粘液分泌和粘液纤毛清除，以及释放 支气管活性物质。在各种细胞系统中的研究已经 证明了对β-肾上腺素能激动剂的反应是动态的 可被β-激动剂和佛波酯等试剂改变。 此外，肾上腺素能反应性的改变可能起到重要作用 在呼吸道疾病的临床表现和治疗中的作用 作为哮喘。令人惊讶的是，人们对β-AR受体知之甚少 人气管、支气管壁上皮细胞。此外，对 β-激动剂和β-AR受体偶联的腺酰环化酶系统 呼吸道中存在的炎性介质(如缓激肽、P物质、 前列腺素E_2)在这些细胞中仍未确定。我们的这一差距 显然，知识对于我们理解 呼吸道疾病的发病机制及其对治疗的反应。 这项提案的目标是描述β-AR耦合 离体气管、支气管上皮细胞的腺酰环化酶系统 从兔子和人类身上获得。Beta-AR最初将是 具有密度、亚型、与G蛋白偶联的特征 (GS)和腺酰环化酶。人类β-AR的亚型 上皮细胞将通过聚合酶链式反应来确定。这个 提高细胞内cAMP水平的药物的效果(例如 β-激动剂、Forsklin、磷酸二酯酶抑制剂) 将评估腺酰环化酶系统的响应性。这个 将阐明任何法规变更所涉及的潜在机制 通过测定受体分布、磷酸化状态和mRNA 级别。类似的研究将被用来描述佛波醇的影响。 酯和炎症介质(如缓激肽、P物质、 前列腺素E_2)对β-AR偶联的腺苷环化酶系统的影响 分离的上皮细胞。最后，雾化变应原对 该系统将在豚草致敏的兔身上进行评估，并处于稳定状态。 人类哮喘患者。这些研究应该有助于阐明这种机制。 正常上皮细胞β-AR偶联腺苷环化酶系统的调节 细胞和从发炎的呼吸道中分离出来的细胞中。

Stimulation of beta-adrenergic receptors (beta-AR) on the tracheobronchial epithelium elicits a variety of cellular responses which affect the defense of the respiratory tract and which may alter the intensity of the inflammatory response in the airway. Beta-adrenergic agonists acting on the tracheobronchial epithelium affect salt and water exchange across the airway wall, mucus secretion and mucociliary clearance, and release of bronchoactive substances. Studies in a variety of cellular systems have demonstrated that the response to beta-adrenergic agonists is dynamic and may be altered by such agents as beta-agonists and phorbol esters. Furthermore, alterations in adrenergic responsiveness may play an important role in the clinical manifestations and treatment of airway diseases such as asthma. Surprisingly, little is known about the beta-AR receptors on tracheobronchial epithelial cells in man. Moreover, the regulation of the beta-AR receptor-coupled adenylyl cyclase system by beta-agonists and inflammatory mediators present in the airway (e.g. bradykinin, substance P, prostaglandin E2) remains undefined in these cells. This gap in our knowledge is of obvious C3 importance to our understanding of the pathogenesis of airway disease and its response to therapy. The objectives of this proposal are to characterize the beta-AR-coupled adenylyl cyclase system in isolated tracheobronchial epithelial cells obtained from rabbits and humans. The beta-AR will initially be characterized with regard to density, subtype, coupling to the G protein (Gs) and to adenylyl cyclase . The subtype of the beta-AR in the human epithelial cells will be determined by the polymerase chain reaction. The effects of agents which raise intracellular cAMP levels (e.g. beta-agonists, forskolin, phosphodiesterase inhibitors) on the responsiveness of the adenylyl cyclase system will be assessed. The potential mechanisms involved in any altered regulation will be elucidated by determining receptor distribution, phosphorylation state and mRNA levels. Similar studies will be used to characterize the effects of phorbol esters and inflammatory mediators (e.g. bradykinin, substance P, prostaglandin E2) on the beta-AR-coupled adenylyl cyclase system in isolated epithelial cells. Finally, the effects of aerosolized allergens on this system will be assessed in ragweed-sensitized rabbits and in stable human asthmatics. These studies should help elucidate the mechanisms regulating the beta-AR-coupled adenylyl cyclase system in normal epithelial cells and in cells isolated from inflamed airways.