title: Protease-activated receptor-2-mediated proliferation and collagen production of rat pancreatic stellate cells.
abstract: Activated pancreatic stellate cells (PSCs) play a pivotal role in the pathogenesis of pancreatic inflammation and fibrosis. Trypsin and tryptase, which are agonists for protease-activated receptor-2 (PAR-2), are involved in the pathogenesis of pancreatitis. Here, we examined whether PSCs expressed PAR-2 and its agonists affect the cell functions of PSCs. PSCs were isolated from rat pancreas tissue. Expression of PAR-2 was examined by Western blotting and reverse transcription-polymerase chain reaction. Trypsin, activating peptide (SLIGRL-NH(2), corresponding to the PAR-2 tethered ligand), and tryptase were tested for their ability to affect proliferation, chemokine production, and collagen synthesis in culture-activated PSCs. Activation of mitogen-activated protein (MAP) kinases was assessed by Western blotting using antiphosphospecific antibodies. The effect of PAR-2 agonists on the activation of freshly isolated PSCs in culture was also examined. PAR-2 expression was observed in culture-activated PSCs, whereas it was undetectable in freshly isolated PSCs. PAR-2 agonists activated activator protein-1 and MAP kinases (extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 MAP kinase) but not nuclear factor kappaB. PAR-2 agonists induced proliferation of PSCs through the activation of extracellular signal-regulated kinase. PAR-2 agonists increased collagen synthesis through the activation of c-Jun N-terminal kinase and p38 MAP kinase. PAR-2 agonists did not induce the production of monocyte chemoattractant protein-1 and cytokine-induced neutrophil chemoattractant-1 or initiate the transformation of freshly isolated PSCs in culture. Taken together, our results suggest a role of PAR-2 in the sustenance of pancreatic fibrosis through the increased proliferation and collagen production in PSCs.
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. amasamune@int3.med.tohoku.ac.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Masamune
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuta
authors.forename: Masahiro
authors.initials: M
authors.lastname: Satoh
authors.forename: Noriaki
authors.initials: N
authors.lastname: Suzuki
authors.forename: Tooru
authors.initials: T
authors.lastname: Shimosegawa
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002452:Cell Count; D049109:Cell Proliferation; D048430:Cell Shape; D002478:Cells, Cultured; D018925:Chemokines / Q000378:metabolism; D003094:Collagen / Q000096:biosynthesis*; D004247:DNA / Q000096:biosynthesis; D024202:Electrophoretic Mobility Shift Assay; D004789:Enzyme Activation / Q000502:physiology; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics; D010179:Pancreas / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D044464:Receptor, PAR-2 / Q000819:agonists / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018808:Transcription Factor AP-1 / Q000235:genetics
chemical_list: D018925:Chemokines; D016328:NF-kappa B; D044464:Receptor, PAR-2; D018808:Transcription Factor AP-1; D003094:Collagen; D004247:DNA; D020928:Mitogen-Activated Protein Kinases