Gene regulatory mechanisms and neurogenic airway inflammation

基因调控机制与神经源性气道炎症

• 批准号: 6504189
• 负责人: GEORGES E. HADDAD
• 金额: $ 24.81万
• 依托单位: HOWARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6504189
• 关键词: asthma; biological signal transduction; bronchomotion; cooperative study; guinea pigs; inflammation; neuroimmunomodulation; neuropeptide receptor; respiratory hypersensitivity; respiratory muscles; smooth muscle; tachykinin

Bronchial asthma is associated with inflammatory changes, swelling, stiffness of the airways, spontaneous, mechanically or chemically evoked bronchoconstriction. These changes can be initiated and maintained by autonomic imbalance in bronchodilatory and bronchoconstrictive influences. In this grant proposal we will stress how the nervous system via a number of differentiated patterns during prolonged and often repeated stimulations, affect airway structure and functions down to cellular and molecular level of organization. In particular, the role of sensory innervation will be studied. Subsets of sensory fibers, both in animals and humans, contain the tachykinin peptides, substance P (SP) and neurokinin A (NKA), which are colocalized with calcitonin gene related peptide (CGRP). In response to noxious agents and bradykinin (BK), SP, NKA and CGRP are released from sensory nerves and when released they exert a variety of local biological effects, including increase in cholinergic transmission, airway smooth muscle (ASM) contraction, mucus secretion and plasma protein extravasation. These changes are mediated through activation of typical features of bronchial asthma. We hypothesize that in bronchial asthma the regulation of the NK-1, NK-2, and NK-3 receptors in achieved via a feedforward mechanism in which peptide synthesis or secretion (or both) is enhanced. Increased levels of released SP and NKA would then cause increased in the expression and the sensitivity of NK-1, NK-2, and NK-3 receptors, and potentiate cholinergic influences. We will investigate changes in SPK, BK and NKA levels, NK-1, NK-2, CGRP, B-1 and B-2 receptor mRNAs and receptor peptide expression in airways of asthmatics and in the airways of sensitized guinea pigs following repeated exposure to antigen. Preprotachykinin (PTT) mRNA expression in the airways will be quantitated using solution hybridization-nuclease protection assays. Peptide and receptor mRNA expression levels will be normalized to glyceraldehyde-3- phosphatedydrogenase mRNA levels. Similarly, expression of the BK receptor message and receptor protein will be determined in guinea pigs. In the airway smooth muscle preparation, the link between changes in signal transduction pathways and airway hyper- responsiveness will be studied. Using biophysical and biochemical approaches, we will assess the changes in contractility of the airway smooth muscle which could account for the refractoriness to therapy by employing techniques well established in our laboratories. The results of proposed studies will contribute to better understanding of fundamental mechanisms of a feedforward system as a determinant of progression of the pathologic process, and will lead to improved methods in treatment of obstructive airway disorders.

支气管哮喘与炎症变化，肿胀，气道僵硬，自发，机械或化学诱发的支气管收缩有关。这些变化可以通过支气管扩张和支气管收缩的影响来引发和维持这些变化。在这项赠款提案中，我们将在长期且经常反复刺激期间通过多种分化模式来强调神经系统如何影响气道结构并降低到组织的细胞和分子水平。特别是，将研究感觉神经的作用。在动物和人类中，感觉纤维的亚集包含速素肽，P（SP）和神经蛋白A（NKA）（NKA），它们与降钙素基因相关肽（CGRP）共定位。为了响应有害的剂和心动激素（BK），SP，NKA和CGRP，从感觉神经释放出来，并且在释放时会发挥各种局部生物学作用，包括增加胆碱能传播，气道平滑肌（ASM）收缩，粘液分泌和血浆蛋白质蛋白质的伸展。这些变化是通过激活支气管哮喘的典型特征来介导的。我们假设在支气管哮喘中，通过进食机制获得了NK-1，NK-2和NK-3受体的调节，其中肽合成或分泌（或两者都会增强）。然后，释放的SP和NKA水平的升高将导致NK-1，NK-2和NK-3受体的表达和灵敏度增加，以及增强的胆碱能影响。我们将研究SPK，BK和NKA水平的变化，NK-1，NK-2，CGRP，B-1和B-2受体mRNA和受体肽表达在哮喘患者的气道以及反复暴露于抗原抗原后敏化豚鼠的气道中。使用溶液杂交核酸酶保护测定法，将对气道中的前曲霉（PTT）mRNA表达进行定量。肽和受体mRNA表达水平将归一化为甘油醛-3-磷酸化酶mRNA水平。同样，将在豚鼠中确定BK受体信息和受体蛋白的表达。在气道平滑肌制备中，将研究信号转导途径变化与气道超反应性之间的联系。使用生物物理和生化方法，我们将评估气道平滑肌收缩性的变化，这可以通过采用在我们的实验室中建立的技术来解释治疗的难治性。拟议的研究结果将有助于更好地理解前馈系统的基本机制，这是病理过程进展的决定因素，并将导致改善治疗阻塞性气道疾病的方法。