title: Roles of transient receptor potential canonical (TRPC) channels and reverse-mode Na+/Ca2+ exchanger on cell proliferation in human cardiac fibroblasts: effects of transforming growth factor β1.
abstract: Expression of transient receptor potential canonical channels (TRPC) and the effects of transforming growth factor-β1 (TGF-β1) on Ca2+ signals and fibroblast proliferation were investigated in human cardiac fibroblasts. The conventional and quantitative real-time RT-PCR, western blot, immunocytochemical analysis, and intracellular Ca2+ concentration [Ca2+]i measurement were applied. Cell proliferation and cell cycle progression were assessed using MTT assays and fluorescence activated cell sorting. Human cardiac fibroblasts have the expression of TRPC1,3,4,6 mRNA and proteins. 1-oleoyl-2-acetyl-sn-glycerol (OAG) and thapsigargin induced extracellular Ca(2+)-mediated [Ca2+]i rise. siRNA for knock down of TRPC6 reduced OAG-induced Ca2+ entry. Hyperforin as well as angiotensin II (Ang II) induced Ca2+ entry. KB-R7943, a reverse-mode Na+/Ca2+ exchanger (NCX) inhibitor, and/or replacement of Na+ with NMDG+ inhibited thapsigargin-, OAG- and Ang II-induced Ca2+ entry. Treatment with TGF-β1 increased thapsigargin-, OAG- and Ang II-induced Ca2+ entry with an enhancement of TRPC1,6 protein expression, suppressed by KB-R7943. TGF-β1 and AngII promoted cell cycle progression from G0/G1 to S/G2/M and cell proliferation. A decrease of the extracellular Ca2+ and KB-R7943 suppressed it. Human cardiac fibroblasts contain several TRPC-mediated Ca2+ influx pathways, which activate the reverse-mode NCX. TGF-β1 enhances the Ca2+ influx pathways requiring Ca2+ signals for its effect on fibroblast proliferation.
authors.affiliation: Department of Cardiovascular Medicine, University of Tokyo, Tokyo 113-8654, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ikeda
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nakajima
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Nami
authors.initials: N
authors.lastname: Takano
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Tanaka
authors.forename: Hironobu
authors.initials: H
authors.lastname: Kikuchi
authors.forename: Gaku
authors.initials: G
authors.lastname: Oguri
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Morita
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Nakamura
authors.forename: Issei
authors.initials: I
authors.lastname: Komuro
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004075:Diglycerides / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D010696:Phloroglucinol / Q000031:analogs & derivatives / Q000494:pharmacology; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D019831:Sodium-Calcium Exchanger / Q000037:antagonists & inhibitors / Q000378:metabolism*; D050052:TRPC Cation Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013729:Terpenes / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
chemical_list: C101670:2-(2-(4-(4-nitrobenzyloxy)phenyl)ethyl)isothiourea methanesulfonate; D004075:Diglycerides; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D019831:Sodium-Calcium Exchanger; D050052:TRPC Cation Channels; D013729:Terpenes; D053773:Transforming Growth Factor beta1; D000804:Angiotensin II; D019284:Thapsigargin; C038237:1-oleoyl-2-acetylglycerol; D010696:Phloroglucinol; D013890:Thiourea; C001654:hyperforin; D002118:Calcium
keywords: Human cardiac fibroblast; NCX1; Proliferation; Reverse-mode Na(+)/Ca(2+) exchanger; TGF-β1, Angiotensin II; TRPC6; Transient receptor potential canonical (TRPC) channels