TRP Channels and Air Pollution

描述(申请人提供)：我们研究的长期目标是通过阐明调节对空气污染(PM)的不良呼吸反应的特定分子途径来改善对受空气污染(PM)颗粒物成分不利影响的人的护理该项目的近期目标是建立差异激活的分子和化学基础。 在最近发现的“PM敏感”钙离子通道中，TRPA1、V1和M8使用两种具有代表性的燃烧衍生颗粒物(CdPM)：柴油PM(DEP)和燃煤飞灰(CFA1)，以揭示这些离子通道在确定PM引起的呼吸道细胞动态平衡和呼吸功能变化中的作用。我们的假设是：TRPA1、V1和M8被cdPM差异激活，这是由于其物理/化学组成、受体特异性的化学和机械敏感结构域以及TRPA1、V1和M8通道的细胞表达/定位。此外，cdPM激活TRPA1、V1和/或M8是DEP、CFA1和类似环境cdPM的肺毒性作用的关键事件。我们的具体目标是：1)精确定位DEP和CFA1激活所需的TRPA1、V1和M8区域；2)将TRPA1、V1和/或M8激活与对DEP和CFA1的特定呼吸道细胞反应联系起来；以及3)证明TRPA1、V1和/或M8是肺组织对DEP和CFA1的病理生理反应的中介。这项研究的假设和目的是基于有趣的结果，表明几种PM，包括DEP和CFA1，与肺细胞表面的这些特定的离子通道蛋白相互作用，并通过独特的药理学机制调节离散的细胞和肺反应，这些反应是通常观察到的PM引起的肺部疾病的基础。我们的支持数据表明，TRPA1主要但不完全是由DEP和另一种与环境相关的cdPM释放的活性化学物质激活的；木材烟雾PM(WSP)，而TRPV1、M8和较小程度的A1是由DEP、CFA1和其他型号PM的不溶成分对细胞表面受体结构域的机械扰动而唯一激活的TRPA1拮抗剂HC-030031可抑制TRPA1拮抗剂HC-030031对神经元的刺激和随后引起的肺顺应性降低，而CFA1通过TRPV1刺激神经元和支气管上皮细胞，肺上皮细胞和肺组织中促炎症和促凋亡基因的诱导在很大程度上依赖于TRPV1的表达和功能(即，在TRPV1-/-小鼠中被拮抗剂LJO-328抑制)。在拟议的研究完成后，我们将提供确凿的证据，证明TRPA1、V1和M8是将空气污染与常见的呼吸道组织不良后果联系起来的特定分子途径。这些信息对于识别由于空气污染而导致健康问题风险最大的高度敏感的个人以及开发创新的临床治疗方法以保护这些人免受PM的不良影响都是至关重要的。 公共卫生相关性：我们的目标是阐明环境颗粒污染物(PM)对人类造成不利影响的基础，以便开发测试以确定PM引发毒性的最高风险个人，并开发特定和有效的医疗干预措施，选择性地减轻PM对人类呼吸道(以及可能的其他)健康问题的不利影响。该项目将调查两个基本问题，这些问题对于实现这些目标和克服我们在急性和慢性暴露情况下防止污染空气的不利影响的能力方面的限制至关重要。问题是：1)哪些蛋白质和这些蛋白质的分子特征可以检测到不同类型的PM？2)由特定类型的PM激活的特定离子通道是否调节肺损伤、呼吸功能障碍，甚至慢性疾病？这些问题的答案对于通过基于人群的研究了解与环境PM暴露相关的广泛健康影响以及开发新的有效方法选择性地减轻不同环境PM对人类的不利影响至关重要。

DESCRIPTION (provided by applicant): The long-term goal of our research is to improve care of persons adversely affected by particulate components of air pollution (PM) by elucidating specific molecular pathways that mediate adverse respiratory responses to PM. The immediate goals of this project are to establish the molecular and chemical basis for differential activation of the recently discovered "PM-sensing" Ca++ channels, TRPA1, V1, and M8, using two representative combustion-derived particles (cdPM): diesel PM (DEP) and coal fly ash (CFA1), to reveal the contributions of these ion channels in determining PM-induced changes in airway cell homeostasis and respiratory function. Our hypothesis is: TRPA1, V1, and M8 are differentially activated by cdPM as a function of its physical/chemical composition, receptor-specific chemo- and mechano-sensing domains, and cellular expression/localization of TRPA1, V1, and M8 channels. Furthermore, activation of TRPA1, V1 and/or M8 by cdPM are pivotal events underlying the pneumotoxic effects of DEP, CFA1, and similar environmental cdPM. Our specific aims are: 1) pinpoint the regions of TRPA1, V1, and M8 required for activation by DEP and CFA1; 2) link TRPA1, V1, and/or M8 activation with specific airway cellular responses to DEP and CFA1; and 3) demonstrate TRPA1, V1, and/or M8 as mediators of pathophysiological responses of lung tissue to DEP and CFA1. The hypothesis and aims of this study are based on fascinating results showing that several PM, including DEP and CFA1, interact with these specific ion channel proteins at the surface of lung cells, and through unique pharmacological mechanisms, regulate discrete cellular and lung responses that underlie commonly observed PM-induced pulmonary morbidities. Our supporting data demonstrate TRPA1 is predominantly, but not exclusively, activated by reactive chemicals released from DEP and another environmentally relevant cdPM; wood smoke PM (WSP), while TRPV1, M8, and to a lesser extent A1, are uniquely activated by mechanical perturbation of cell surface receptor domains by insoluble components of DEP, CFA1, and other model PM. Neuronal stimulation and subsequent reduction in lung compliance elicited by DEP are inhibited by the TRPA1 antagonist HC-030031, and both neurons and bronchial epithelial cells are stimulated by CFA1 via TRPV1, with pro-inflammatory and pro-apoptotic gene induction in lung epithelial cells and lung tissue being largely dependent upon TRPV1 expression and function (i.e., inhibited by the antagonist LJO-328 or in TRPV1-/- mice). Upon completion of the proposed studies, we will provide conclusive evidence that TRPA1, V1, and M8 are specific molecular pathways that link air pollution to commonly observed adverse outcomes in respiratory tissue. This information is essential for both identifying highly sensitive individuals at greatest risk for developing health problems due to air pollution and developing innovative clinical treatments to protect such people from the adverse effects of PM. PUBLIC HEALTH RELEVANCE: Our objective is to elucidate the basis by which environmental particulate pollutants (PM) adversely affect humans such that tests can be developed to identify individuals at greatest risk of PM-induced toxicities and specific and effective medical interventions can be developed to selectively attenuate the adverse effects of PM on human respiratory (and possibly other) health issues. This project will investigate two fundamental questions central to achieving these objectives and to overcoming limitations in our ability to prevent the adverse effects of polluted air in both acute and chronic exposure scenarios. The questions are: 1) what proteins, and molecular features of these proteins, detect different types of PM? and 2) does activation of a specific ion channel by a specific type of PM regulate lung injury, respiratory dysfunction, or even chronic disease? Answers to these questions are critical to understanding the broad health effects linked to environmental PM exposure by population-based studies and for the development of new and effective ways to selectively mitigate the adverse effects of heterogeneous environmental PM in humans.