title: Type of cell death induced by various metal cations in cultured human gingival fibroblasts.
abstract: Metal ions are released from casting alloys and cause damage to cell structures and local inflammation. However, the cytotoxic mechanism and the type of cell death induced in human gingival fibroblast (HGF) by contact with dental metals have not been well characterized. Here the cytotoxicity of eight metals against HGF was investigated. Cytoxicity of metals against HGF was in the following order: Ag(NH(3))(2)F (most cytotoxic)>AgCl>CuCl(2)>CuCl, CoCl(2)> NiCl(2)>FeCl(2), FeCl(3) (least cytotoxic). None of the metals showed any apparent hormetic growth stimulation at lower concentrations, except for Ag(NH(3))(2)F at 20 or higher population-doubling level of HGF. The sensitivity of HGF against Ag(NH(3))(2)F was reduced during in vitro aging, similar to previous report with sodium fluoride. Contact with Ag(NH(3))(2)F for only one hour induced irreversible cell death, whereas longer duration of contact with AgCl or CuCl(2) was necessary to induce irreversible cell death. These metals induced neither DNA fragmentation nor caspase-3 activation. Pan-caspase inhibitor (Z-VAD-FMK) and autophagy inhibitors (3-methyladenine, bafilomycin) did not apparently affect the cytotoxicity of metals, when corrected for the effect of inhibitor alone on growth. We also found that Ag(NH(3))(2)F induced much higher cytotoxicity than AgCl in mouse osteoblastic cell line MC3T3-E1, possibly inducing necrosis. These data suggest the importance of cautious application of Ag(NH(3))(2)F to the oral cavity.
authors.affiliation: Dental Research Center (CIEAO), Faculty of Dentistry, Autonomous University of State of Mexico (UAEM), Toluca, Estado de México, México.
authors.forename: René García
authors.initials: RG
authors.lastname: Contreras
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakagami
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakajima
authors.forename: Jun
authors.initials: J
authors.lastname: Shimada
mesh_terms: D000818:Animals; D002412:Cations / Q000633:toxicity*; D016923:Cell Death / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002712:Chlorides / Q000633:toxicity; D003300:Copper / Q000633:toxicity; D003748:Dental Equipment; D005290:Ferric Compounds / Q000633:toxicity; D005296:Ferrous Compounds / Q000633:toxicity; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000473:pathology; D005881:Gingiva / Q000166:cytology* / Q000187:drug effects / Q000473:pathology; D006801:Humans; D007700:Kinetics; D008670:Metals / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D009336:Necrosis; D009532:Nickel / Q000633:toxicity; D010165:Palladium / Q000633:toxicity; D018030:Silver Compounds / Q000633:toxicity
chemical_list: D002412:Cations; D002712:Chlorides; D005290:Ferric Compounds; D005296:Ferrous Compounds; D008670:Metals; D018030:Silver Compounds; D010165:Palladium; C022838:nickel chloride; D003300:Copper; D009532:Nickel; C037548:silver chloride; C029892:cupric chloride; C029451:ferrous chloride; C024555:ferric chloride