title: The localization of the relaxed form of plasminogen activator inhibitor type 2 in human gingival tissues.
abstract: The plasminogen activating system is important in extracellular proteolysis. Plasmin degrades tissues and activates proteases. Plasminogen activators (tissue type; t-PA and urokinase type; u-PA) and plasminogen activator inhibitors (PAI-1, PAI-2) are found in high concentrations in gingival crevicular fluid (GCF). Previous findings indicate the significance of PAI-2 in gingival inflammation. When PAI-2 inhibits a plasminogen activator its conformation relaxes and neoepitopes can be detected with a monoclonal antibody (#2H5). Our aim was to study if and where in the gingival region PAI-2 has acted as an inhibitor. Methodological studies were performed on GCF with western blotting. Frozen sections of human gingiva were studied immunohistochemically. The methodological studies showed that our antibody #2H5 selectively detects relaxed low molecular weight non-glycosylated PAI-2. Total PAI-2 and relaxed PAI-2 were found in all gingival epithelia with a honeycomb-like staining. Relaxed PAI-2 showed the most pronounced staining in the cell layers near the surface of the epithelium and no staining in the suprabasal layers, while total PAI-2 was found throughout the epithelium, often more pronounced suprabasally. The results showed that PAI-2 indeed has acted as an inhibitor of a protease in gingival tissues, primarily in the epithelia. The results also suggest primarily an intracellular localization and thus the interaction of PAI-2 with a protein other than t-PA.
authors.affiliation: Department of Periodontology, Odontological Faculty, School of Dentistry, Carl Gustafs väg 34, 214 21 Malmö, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Lindberg
authors.forename: M S
authors.initials: MS
authors.lastname: Baker
authors.forename: B
authors.initials: B
authors.lastname: Kinnby
mesh_terms: D000911:Antibodies, Monoclonal; D001706:Biopsy; D015153:Blotting, Western; D004847:Epithelial Cells / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D019084:Fluorescent Antibody Technique, Indirect; D005881:Gingiva / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D005883:Gingival Crevicular Fluid / Q000737:chemistry / Q000378:metabolism; D005891:Gingivitis / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D017396:Plasminogen Activator Inhibitor 2 / Q000032:analysis / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D017396:Plasminogen Activator Inhibitor 2