MECHANISMS OF LUNG BETA2AR FUNCTION IN TRANSGENIC MICE

转基因小鼠肺β2AR功能的机制

• 批准号: 2822802
• 负责人: Dennis W McGraw
• 金额: $ 13.13万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-04 至 2004-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2822802
• 关键词: beta adrenergic receptor; biological models; bronchomotion; cell type; genetically modified animals; inflammation; laboratory mouse; model design /development; receptor expression; respiratory epithelium; respiratory hypersensitivity; smooth muscle

Beta-agonists are potent bronchodilators that are frequently used in the treatment of bronchospastic lung diseases such as asthma. In the intact lung, Beta-agonists-mediated bronchodilation may result from the activation of Beta2ARs on a number of different cell types. However, the relative contribution of B2AR signaling from any one of these cell types is unclear. One potential approach to delineate these cell-specific effects in vivo is to use transgenesis to selectively over express, and thus activate, Beta2AR on specific cells. By using cell-specific promoters to target receptor expression, we propose to create multiple lines of transgenic mice that over express the Beta2AR in airway epithelium and in airway smooth muscle. Preliminary ex vivo and in vivo studies have indicated a significant Bets2AR- mediated communication between the epithelium and smooth muscle, in that over expression of the Beta2AR -mediated communication between the epithelium and smooth muscle, in airway epithelium decreases bronchial hyperactivity. Over expression on airway smooth muscle results in another phenotype, and this allows for assessment of each pathway with regard to Beta2AR regulation of airway function. Using a strategy that integrates molecular biological, pharmacological and physiological techniques, we propose to use such transgenic approaches to: (1) establish the role of epithelial cell Beta2ARs in regulating smooth muscle function; (2) selectively delineate Beta2AR signaling and function in airway smooth muscle; and (3) assess the effects of epithelial and smooth muscle Beta2AR over expression on airway inflammation and bronchial hyperresponsiveness. The candidate has completed a clinical fellowship in Pulmonary and Critical Care. During that time the candidate used basic molecular biological techniques to begin studies of Beta2AR gene expression. The candidate became interested in pursuing these studies further, and made the decision to move to the laboratory of Stephen Liggett at he University of Cincinnati Medical Center. After gaining more intensive laboratory experience, the candidate, mentor and secondary mentor (Jeffrey Whitsett) developed a plan utilizing transgenesis to study how Beta2AR on different cell types regulate airway function. The training plan proposed incorporates a variety of pharmacological and physiological techniques that represent a significant departure from the candidate's previous experience. Learning these additional techniques will serve to advance the candidate's skills to the level of autonomous investigator. To this aim, an environment has been created that is uniquely conducive to the candidate's training. This includes the mentor ship of Drs. Liggett and Whitsett, and an Advisory committee composed of established investigators with extensive experience in raining physicians scientists.

β-受体激动剂是有效的支气管扩张剂，常用于治疗支气管痉挛性肺病，如哮喘。 在完整的肺中，β激动剂介导的支气管扩张可能是由于许多不同细胞类型上的β 2 AR活化所致。然而，来自这些细胞类型中的任何一种的B2 AR信号传导的相对贡献尚不清楚。描述这些细胞特异性体内效应的一种潜在方法是使用转基因选择性过表达，从而激活特定细胞上的β 2 AR。 通过使用细胞特异性启动子靶向受体表达，我们建议创建多个品系的转基因小鼠，在气道上皮和气道平滑肌中过表达β 2 AR。 初步的离体和体内研究已经表明上皮和平滑肌之间显著的Bets 2AR介导的通讯，因为气道上皮中上皮和平滑肌之间Beta2 AR介导的通讯的过表达降低了支气管过度活跃. 气道平滑肌上的过度表达导致另一种表型，这允许评估关于气道功能的β 2 AR调节的每种途径。 本研究采用分子生物学、药理学和生理学相结合的方法，通过转基因技术，建立了上皮细胞β 2 AR在调节气道平滑肌功能中的作用，选择性地研究了β 2 AR在气道平滑肌中的信号传导和功能，并对β 2 AR在气道平滑肌中的作用机制进行了初步探讨。（3）评估上皮和平滑肌β 2 AR过表达对气道炎症和支气管高反应性的影响。候选人已经完成了肺和重症监护的临床奖学金。 在此期间，候选人使用基本的分子生物学技术开始研究β 2 AR基因表达。这位候选人对进一步进行这些研究产生了兴趣，并决定搬到辛辛那提大学医学中心的斯蒂芬·利格特实验室。 在获得更深入的实验室经验后，候选人、导师和二级导师（Jeffrey惠特塞特）制定了一项利用转基因研究不同细胞类型上的Beta2 AR如何调节气道功能的计划。拟议的培训计划包括各种药理学和生理学技术，与候选人以往的经验有很大不同。 学习这些额外的技术将有助于提高候选人的技能，使其达到自主调查的水平。 为此目的，创造了一个特别有利于候选人培训的环境。 这包括Liggett博士和惠特塞特博士的导师，以及一个由在培养医生科学家方面具有丰富经验的知名调查人员组成的咨询委员会。