Human neutrophil elastase releases cell surface mucins from primary cultures of hamster tracheal epithelial cells.
Primary hamster tracheal epithelial cells growing on a collagen gel matrix produce high molecular weight mucins indistinguishable from mucins produced in vivo. Using a modified version of these confluent cultures, we have demonstrated here that (i) release of mucins can be stimulated by human neutrophil elastase (HNE; EC 3.4.21.37); (ii) HNE can degrade mucins, and both mucin release and degradation by HNE require an active catalytic site; and (iii) there are at least two pools of mucins in these cells: one is a rapidly turning-over spontaneously releasable constitutive pool, the other is a slowly turning-over HNE-releasable pool. We provide evidence that the HNE-releasable mucins are membrane bound and associated with the secretory cell apical surface.
D000818:Animals; D002478:Cells, Cultured; D006224:Cricetinae; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007700:Kinetics; D008854:Microscopy, Electron; D009077:Mucins / Q000378:metabolism*; D009504:Neutrophils / Q000201:enzymology*; D010196:Pancreatic Elastase / Q000378:metabolism*; D014132:Trachea / Q000166:cytology / Q000378:metabolism*
D009077:Mucins; D010196:Pancreatic Elastase