Signaling and Crosstalk by Airway Prostanoid Receptors

气道前列腺素受体的信号传导和串扰

• 批准号: 6941668
• 负责人: Dennis W McGraw
• 金额: $ 34.54万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6941668
• 关键词: arachidonate; asthma; beta adrenergic receptor; biological signal transduction; bronchospasm; gene targeting; genetically modified animals; laboratory mouse; muscle contraction; prostaglandin E; prostaglandin F; prostaglandin receptor; prostaglandins; protein isoforms; protein structure function; receptor expression; respiratory function; smooth muscle; thromboxanes; tissue /cell culture

DESCRIPTION (provided by applicant): Prostanoids have been implicated in the pathogenesis of bronchoconstriction and airway hyperreactivity (AHR) because they potently contract airway smooth muscle (ASM), and their levels, are elevated in asthmatic lung. Thromboxane, PGD2 and PGF2alpha contract ASM via activation of thromboxane prostanoid (TP) receptors. Even PGE2, which is generally considered a bronchodilator, has the capacity to transduce a constrictor signal via one of the receptor subtypes (EP1) for which it is the cognate ligand. However, despite their potent effects on ASM, it has been difficult to unambiguously assign pathophysiological relevance to these receptors due to pleiotropic responses resulting from the simultaneous production of constrictor and relaxant prostanoids by the same general enzymatic pathway, receptor activation by multiple ligands, and the existence of multiple receptor isoforms with different signal transduction properties. We believe these limitations can be overcome by using transgenic and gene-targeted mice to selectively modulate signal transduction by specific prostanoid receptors. In this proposal, we will test the overall hypothesis that bronchoconstriction and AHR occur when the activation of bronchoconstrictor prostanoid receptors is favored over those that promote bronchodilation. In Specific Aim 1, we will use mice that overexpress the TP receptor in combination with TP receptor deficient gene-targeted mice to determine whether TP receptors promote bronchoconstriction and AHR. The signaling pathways, which mediate TP receptor-dependent contraction will be dissected in vitro using primary ASM cells, isolated from the genetically engineered mice, and their physiologic significance determined in tracheal rings and intact mice. In Specific Aim 2, we will determine whether the EPt receptor is a mediator of bronchoconstriction and AHR. The transgenic models developed for these experiments will enable us to discriminate between the effects of EP1 receptor activation and those of the other EP receptor subtypes. Since it widely recognized that the primary physiologic actions of one G-protein-coupled receptor are frequently modulated by another, experiments in Specific Aim 3 will test the hypothesis that receptor cross talk by TP and EP1 receptors is a mechanism of (-adrenergic receptor dysfunction in ASM. This hypothesis is supported by preliminary data that show TP and EP1 receptor agonists attenuate isoproterenol-mediated relaxation of tracheal rings. Each of these aims will merge biochemical, pharmacologic and physiologic studies from cells, tissues, and whole animals so that in vitro signaling events can be directly correlated to in vivo physiological function. Completion of these aims may identify novel signaling events that have therapeutic relevance to asthma and other obstructive lung diseases.

描述（由申请人提供）：前列腺素与支气管收缩和气道高反应性（AHR）的发病机理有关，因为它们在哮喘肺中有效地签约气道平滑肌（ASM）及其水平升高。 血栓烷，PGD2和PGF2Alpha合同ASM通过激活血栓烷前列腺素（TP）受体。 即使是通常认为是支气管扩张剂的PGE2，也具有通过一种受体亚型（EP1）转导收缩器信号的能力，其是同源配体。 然而，尽管对ASM产生了有效的影响，但由于多种酶促途径的同时产生约束和松弛前列腺素的同时产生，由多个受体的受体激活以及多种受体各种特性，因此很难明确地将病理生理相关性与这些受体分配给这些受体，这是由于多效性反应和相同的一般酶促途径的同时产生而产生的。 我们认为，可以通过使用转基因和靶向基因的小鼠选择性地通过特定前列腺素受体调节信号转导，可以克服这些局限性。 在该提案中，我们将检验总体假设，即当支气管收缩前列腺素受体的激活比促进支气管扩张的人时，发生支气管收缩和AHR。 在特定的目标1中，我们将使用与TP受体缺乏基因靶向小鼠结合过表达TP受体的小鼠，以确定TP受体是否促进了支气管收缩和AHR。 使用原代ASM细胞从基因工程小鼠分离出介导TP受体依赖性收缩的信号通路将在体外进行剖析，并在气管环和完整小鼠中确定的生理意义。 在特定目标2中，我们将确定EPT受体是否是支气管收缩和AHR的介体。 为这些实验开发的转基因模型将使我们能够区分EP1受体激活的作用和其他EP受体亚型的作用。 由于它被广泛认识到，一个G蛋白耦合受体的主要生理作用经常受到另一个受体的调节，因此特定目标3中的实验将检验以下假设：TP和EP1受体的受体交叉交叉交叉交叉交叉探索是一种机制，是（肾上腺素能受体在ASM中的肾上腺功能障碍的机制。这些目标的放松将合并来自细胞，组织和整个动物的生化，药理学和生理研究，以便在体外信号事件可以直接与体内生理功能相关。