title: Thrombin-stimulated proliferation is mediated by endothelin-1 in cultured rat gingival fibroblasts.
abstract: Abstract Endothelin-1 (ET-1) appears to be involved in drug-induced proliferation of gingival fibroblasts. Thrombin induces proliferation of human gingival fibroblasts via protease-activated receptor 1 (PAR1). In this study, using cultured rat gingival fibroblasts, we investigated whether thrombin-induced proliferation of gingival fibroblasts is mediated by ET-1. Thrombin-induced proliferation (0.05-2.5 U/mL). Proliferation was also induced by a PAR1-specific agonist (TFLLR-NH(2,) 0.1-30 microm), but not by a PAR2-specific agonist (SLIGRL-NH(2)). Thrombin (2.5 U/mL) induced an increase in immunoreactive ET-1 expression, which was inhibited by cycloheximide (10 microg/mL), and an increase in preproET-1 mRNA expression, as assessed by reverse transcription polymerase chain reaction. TFLLR-NH(2) increased ET-1 release into the culture medium in both a concentration (0.01-10 microm)- and time (6-24 h)-dependent manner, as assessed by solid phase sandwich enzyme-linked immunosorbent assay. The thrombin (2.5 U/mL)-induced proliferation was inhibited by a PAR1-selective inhibitor, SCH79797 (0.1 microm) and an ET(A) antagonist, BQ-123 (1 microm), but not by an ET(B) antagonist, BQ-788 (1 microm). These findings suggest that thrombin, acting via PAR1, induced proliferation of cultured rat gingival fibroblasts that was mediated by ET-1 acting via ET(A).
authors.affiliation: Laboratory of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Josai International University, 1 Gumyo, Togane, Chiba 283-8555, Japan. ohuchi@jiu.ac.jp
authors.forename: Nozomi
authors.initials: N
authors.lastname: Ohuchi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hayashi
authors.forename: Keishi
authors.initials: K
authors.lastname: Iwamoto
authors.forename: Katsuo
authors.initials: K
authors.lastname: Koike
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kizawa
authors.forename: Michiyoshi
authors.initials: M
authors.lastname: Nukaga
authors.forename: Tomohito
authors.initials: T
authors.lastname: Kakegawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Murakami
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1 / Q000096:biosynthesis / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005881:Gingiva / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D019214:Gingival Overgrowth / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D051381:Rats; D044463:Receptor, PAR-1 / Q000819:agonists; D044464:Receptor, PAR-2 / Q000819:agonists; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013917:Thrombin / Q000494:pharmacology* / Q000502:physiology; D013997:Time Factors
chemical_list: D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1; D044463:Receptor, PAR-1; D044464:Receptor, PAR-2; D013917:Thrombin