title: Fluoride induces apoptosis and alters collagen I expression in rat osteoblasts.
abstract: In this study we investigated apoptosis and expression of the collagen I gene in newborn rat osteoblasts (OB) by the administration of varying concentrations of fluoride (F). Sodium fluoride (NaF) at concentrations of 0, 0.5, 5, 10, and 20mg/L was administered to cultured OB. The percentage of G(1)/G(0) (Gap 1/Gap 0), S (synthesis), G(2)/M (Gap 2/M, mitosis), and apoptosis rates in OB were analyzed with a Fluorescence-activated Cell Sorter (FACS) by propidium iodine (PI) staining after F treatment of 72 h. Effects of F treatment on COL1A1 and COL1A2 mRNA and collagen I protein levels were determined using quantitative real time RT-PCR (qRT-PCR) and immunofluorescence, respectively. This study demonstrates that there is a pronounced negative effect of long term NaF treatment on OB survival. These negative effects include an inhibition of the transformation from S phase into G(2)/M phase, increased apoptosis, and decreased COL1A1 mRNA, down-regulating the synthesis of COL I protein. The results suggest that COL I protein degradation in OB from F toxicity is due to a depletion of COL1A1 mRNA and not COL1A2.
authors.affiliation: Shanxi Key Laboratory of Ecological Animal Science and Environmental Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, PR China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yan
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Yan
authors.forename: Alex
authors.initials: A
authors.lastname: Morrison
authors.forename: Tianlong
authors.initials: T
authors.lastname: Han
authors.forename: Qinglin
authors.initials: Q
authors.lastname: Chen
authors.forename: Ji
authors.initials: J
authors.lastname: Li
authors.forename: Jundong
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis / Q000235:genetics; D024042:Collagen Type I / Q000096:biosynthesis* / Q000235:genetics; D000090602:Collagen Type I, alpha 1 Chain; D005260:Female; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012969:Sodium Fluoride / Q000633:toxicity*
chemical_list: D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D012969:Sodium Fluoride; D003094:Collagen