Lee Pureun-Haneul, Park Shinhee, Lee Yun-Gi, Choi Seon-Muk, An Min-Hyeok, Jang An-Soo
Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
Allergy Asthma Immunol Res. 2021 Nov;13(6):850-862. doi: 10.4168/aair.2021.13.6.850.
Respiratory epithelial cells form a selective barrier between the outside environment and underlying tissues. Epithelial cells are polarized and form specialized cell-cell junctions, known as the apical junctional complex (AJC). Assembly and disassembly of the AJC regulates epithelial morphogenesis and remodeling processes. The AJC consists of tight and adherens junctions, functions as a barrier and boundary, and plays a role in signal transduction. Endothelial junction proteins play important roles in tissue integrity and vascular permeability, leukocyte extravasation, and angiogenesis. Air pollutants such as particulate matter, ozone, and biologic contaminants penetrate deep into the airways, reaching the bronchioles and alveoli before entering the bloodstream to trigger airway inflammation. Pollutants accumulating in the lungs exacerbate the symptoms of respiratory diseases, including asthma and chronic obstructive lung disease. Biological contaminants include bacteria, viruses, animal dander and cat saliva, house dust mites, cockroaches, and pollen. Allergic inflammation develops in tissues such as the lung and skin with large epithelial surface areas exposed to the environment. Barrier dysfunction in the lung allows allergens and environmental pollutants to activate the epithelium and produce cytokines that promote the induction and development of immune responses. In this article, we review the impact of environmental pollutants on the cell barrier in respiratory diseases.
呼吸道上皮细胞在外部环境与下层组织之间形成了一道选择性屏障。上皮细胞呈极化状态，并形成称为顶端连接复合体（AJC）的特殊细胞间连接。AJC的组装和解聚调节上皮形态发生和重塑过程。AJC由紧密连接和黏附连接组成，起到屏障和边界的作用，并在信号转导中发挥作用。内皮连接蛋白在组织完整性和血管通透性、白细胞外渗及血管生成中起重要作用。诸如颗粒物、臭氧和生物污染物等空气污染物可深入气道，在进入血液引发气道炎症之前到达细支气管和肺泡。积聚在肺部的污染物会加重包括哮喘和慢性阻塞性肺疾病在内的呼吸道疾病症状。生物污染物包括细菌、病毒、动物皮屑和猫唾液、屋尘螨、蟑螂和花粉。在诸如肺和皮肤等上皮表面积大且暴露于环境的组织中会发生变应性炎症。肺部的屏障功能障碍使过敏原和环境污染物能够激活上皮细胞并产生促进免疫反应诱导和发展的细胞因子。在本文中，我们综述了环境污染物对呼吸道疾病中细胞屏障的影响。
