title: Enhancement of cytotoxic activity of sodium fluoride against human periodontal ligament fibroblasts by water pressure.
abstract: Whether or not water pressure enhances the cytotoxic activity of sodium fluoride (NaF) against human periodontal ligament fibroblast (HPLF) was investigated. Loading with water pressure (up to 5 g) alone did not affect the cell proliferation, but significantly enhanced the cytotoxic activity of millimolar concentrations of NaF. Cytotoxic activity of NaF was reduced by supplementation with Ca2+, whereas it was enhanced by removal of Ca2+ from the culture medium. However, the enhancement of cytotoxicity of NaF under water pressure was observed even in the Ca2+ -free medium. NaF failed to induce apoptosis markers, such as the caspase-3, -8 and -9 activation, the intemucleosomal DNA fragmentation, the loss of cell surface microvilli and the changes in intracellular concentration of polyamines. Transmission electron microscopy demonstrated that the combination of NaF and water pressure slightly increased the incidence of the formation of autophagosomes engulfing organella, suggesting the induction of non-apoptotic cell death in HPLF cells. The present study suggests that the external pressure is an additional factor that enhances the cytotoxicity of NaF against HPLF cells.
authors.affiliation: Division of Orthodontic, Department of Human Development and Fostering, Meikai University School of Dentistry, Sakado, Saitama 350-0283, Japan.
authors.forename: Chien-Huan
authors.initials: CH
authors.lastname: Chien
authors.forename: Sumiko
authors.initials: S
authors.lastname: Otsuki
authors.forename: Shahead Ali
authors.initials: SA
authors.lastname: Chowdhury
authors.forename: Masaki
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Keiso
authors.initials: K
authors.lastname: Takahashi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kanda
authors.forename: Shiro
authors.initials: S
authors.lastname: Kunii
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakagami
authors.forename: Haruhide
authors.initials: H
authors.lastname: Kanegae
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects; D002118:Calcium / Q000494:pharmacology; D020169:Caspases / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002648:Child; D053938:DNA Fragmentation / Q000187:drug effects; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D018922:HL-60 Cells; D006801:Humans; D006874:Hydrostatic Pressure; D010513:Periodontal Ligament / Q000166:cytology*; D011700:Putrescine / Q000378:metabolism; D012969:Sodium Fluoride / Q000494:pharmacology*
chemical_list: D003609:Dactinomycin; D012969:Sodium Fluoride; D020169:Caspases; D002118:Calcium; D011700:Putrescine