Epithelial-mesenchymal transition of human lung adenocarcinoma A549 cells up-regulates cytokine production upon LPS stimulation

摘要

Epithelial-mesenchymal transition (EMT) is a biologic processby which differentiated epithelial cells lose such epithelial characteristics as apical-basal polarity and mutual adhesiveness andtransform into cells having mesenchymal characteristics such asenhanced migratory ability, invasiveness, elevated resistance toapoptosis and increased production of extracellular matrix components.1 A wide variety of evidence shows that EMT is deeplyinvolved in the pathophysiology of various respiratory diseases.For instance, EMT seems to contribute to airway remodeling inallergic asthma2 as well as to small airway remodeling and largeairway angiogenesis in chronic obstructive pulmonary diseases3through activation of a potent in vitro EMT-inducer, TGF-b.4 In addition to that, the presence of alveolar epithelial cells that have undergone EMT is thought to be related to the pathogenesis ofidiopathic pulmonary fibrosis (IPF).