title: Colonic luminal proteases activate colonocyte proteinase-activated receptor-2 and regulate paracellular permeability in mice.
abstract: Luminal activation of protease-activated receptors-2 (PAR(2)) on colonocytes by trypsin or PAR(2)-activating peptide increases colonic paracellular permeability (CPP). The aim of this study was to evaluate the role of proteases from endogenous and bacterial origin in the modulation of CPP and colonocyte PAR(2) expression in mice. CPP was assessed with (51)Cr-EDTA after intracolonic administration of different protease inhibitors. After 12 days of oral antibiotic treatment, measurements of colonic luminal serine protease activity (CLSPA), CPP, mucosal mouse mast cell proteinase-1 (MMCP-1) content, immunochemistry of PAR(2) and assessment of effects of PAR(2) agonist (SLIGRL) and mast cell degranulator (C48/80) on CPP in Ussing chambers were performed. Immunochemistry was repeated after intracolonic trypsin administration. Colonic infusion of protease inhibitors significantly reduced CPP. In antibiotic-treated mice, CLSPA was reduced coupled with a decrease in PAR(2) expression, but with no change in CPP and MMCP-1 content. Trypsin administration restored PAR(2) expression. The increase in CPP induced by SLIGRL and C48/80 was reduced after antibiotic treatment. Protease activity of colonic content plays an important role in the regulation of mucosal barrier through activation of PAR(2).
authors.affiliation: INRA Neuro-Gastroenterology & Nutrition Unit, Toulouse, France.
authors.forename: R
authors.initials: R
authors.lastname: Róka
authors.forename: J
authors.initials: J
authors.lastname: Demaude
authors.forename: N
authors.initials: N
authors.lastname: Cenac
authors.forename: L
authors.initials: L
authors.lastname: Ferrier
authors.forename: C
authors.initials: C
authors.lastname: Salvador-Cartier
authors.forename: R
authors.initials: R
authors.lastname: Garcia-Villar
authors.forename: J
authors.initials: J
authors.lastname: Fioramonti
authors.forename: L
authors.initials: L
authors.lastname: Bueno
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002463:Cell Membrane Permeability / Q000502:physiology*; D003106:Colon / Q000166:cytology / Q000201:enzymology* / Q000382:microbiology; D003911:Dextrans; D004797:Enzyme-Linked Immunosorbent Assay; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D011480:Protease Inhibitors / Q000494:pharmacology; D044464:Receptor, PAR-2 / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism
chemical_list: D003911:Dextrans; D011480:Protease Inhibitors; D044464:Receptor, PAR-2; C015219:fluorescein isothiocyanate dextran; D012697:Serine Endopeptidases; D016650:Fluorescein-5-isothiocyanate