title: Bronchial epithelial cells: The key effector cells in the pathogenesis of chronic obstructive pulmonary disease?
abstract: The primary function of the bronchial epithelium is to act as a defensive barrier aiding the maintenance of normal airway function. Bronchial epithelial cells (BEC) form the interface between the external environment and the internal milieu, making it a major target of inhaled insults. However, BEC can also serve as effectors to initiate and orchestrate immune and inflammatory responses by releasing chemokines and cytokines, which recruit and activate inflammatory cells. They also produce excess reactive oxygen species as a result of an oxidant/antioxidant imbalance that contributes to chronic pulmonary inflammation and lung tissue damage. Accumulated mucus from hyperplastic BEC obstructs the lumen of small airways, whereas impaired cell repair, squamous metaplasia and increased extracellular matrix deposition underlying the epithelium is associated with airway remodelling particularly fibrosis and thickening of the airway wall. These alterations in small airway structure lead to airflow limitation, which is critical in the clinical diagnosis of chronic obstructive pulmonary disease (COPD). In this review, we discuss the abnormal function of BEC within a disturbed immune homeostatic environment consisting of ongoing inflammation, oxidative stress and small airway obstruction. We provide an overview of recent insights into the function of the bronchial epithelium in the pathogenesis of COPD and how this may provide novel therapeutic approaches for a number of chronic lung diseases.
authors: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors: Wei
authors: W
authors: Gao
authors: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors: Lingling
authors: L
authors: Li
authors: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors: Yujie
authors: Y
authors: Wang
authors: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors: Sini
authors: S
authors: Zhang
authors: Airway Disease Section, National Heart and Lung Institute, Imperial College, London, UK.
authors: Ian M
authors: IM
authors: Adcock
authors: Airway Disease Section, National Heart and Lung Institute, Imperial College, London, UK.
authors: Peter J
authors: PJ
authors: Barnes
authors: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors: Mao
authors: M
authors: Huang
authors: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors: Xin
authors: X
authors: Yao
mesh_terms: D000402:Airway Obstruction / Q000378:metabolism / Q000503:physiopathology; D018925:Chemokines / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D008168:Lung / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
chemical_list: D018925:Chemokines
keywords: chronic obstructive pulmonary disease; epithelial cell; immunity; inflammation; oxidative stress