title: Tissue injury alters the site of expression of hepatocyte growth factor activator inhibitor type 1 in bronchial epithelial cells.
abstract: Hepatocyte growth factor activator inhibitor-1 (HAI-1) is a Kunitz-type transmembrane serine proteinase inhibitor that inhibits trypsin-like serine proteinases, such as hepatocyte growth factor activator, matriptase, hepsin and prostasin. HAI-1 is expressed in polarized epithelial cells, in which HAI-1 is mainly located on the basolateral membrane. In the present study, we analyzed the expression and distribution of HAI-1 in respiratory epithelium. We found that HAI-1 is expressed by the bronchial respiratory epithelium with basal or basolateral localization and also by the alveolar epithelium. Bronchial expression of HAI-1 was also confirmed using cultured human bronchial epithelial cells. The epithelial expression of HAI-1 was augmented in response to tissue injury such as cancer invasion and inflammation. Surprisingly, in the injured pulmonary tissue, HAI-1 showed distinct apical translocation in ciliated epithelial cells of the bronchiole. We suggest that, in addition to its basolateral surface localization, HAI-1 can transiently localize to the apical surface of respiratory ciliated epithelial cells under conditions of severe inflammation, possibly interacting with a specific cellular proteinase on the apical surface.
authors.affiliation: Section of Oncopathology and Regenerative Biology, Department of Pathology, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Fukushima
authors.forename: Kenji
authors.initials: K
authors.lastname: Yorita
authors.forename: Makiko
authors.initials: M
authors.lastname: Kawaguchi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kataoka
mesh_terms: D001980:Bronchi / Q000166:cytology* / Q000473:pathology; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation / Q000235:genetics*; D053491:Proteinase Inhibitory Proteins, Secretory / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D053491:Proteinase Inhibitory Proteins, Secretory; C109149:SPINT1 protein, human