title: Nicotine affects mineralized nodule formation by the human osteosarcoma cell line Saos-2.
abstract: Several in vitro and in vivo studies have indicated that tobacco smoking may be an important risk factor for the development and severity of inflammatory periodontal disease. In the present study, we examined the effect of nicotine on cell proliferation, alkaline phosphatase (ALPase) activity, mineralized nodule formation, and the expression of extracellular matrix proteins in the human osteosarcoma cell line Saos-2. The cells were cultured with Dulbecco's modified Eagle medium containing 10% fetal bovine serum with 0, 10(-4) M, and 10(-3) M nicotine for up to 14 days. Mineralized nodule formation was examined by alizarin red staining, and the calcium content in mineralized nodules was determined using a calcium E-test kit. The expression of extracellular matrix proteins was estimated by determining the levels of their mRNAs using the real-time polymerase chain reaction. Mineralized nodule formation and calcium content in mineralized nodules were remarkably suppressed by nicotine on days 10 and 14 of culture, respectively. ALPase activity as well as type I collagen and osteopontin expression also decreased in the presence of nicotine after 5, 10, and 14 days of culture, respectively. By contrast, the amount of bone sialoprotein increased during 14 days of culture with nicotine. These results suggest that nicotine suppresses osteogenesis through a decrease in ALPase and type I collagen production by osteoblasts.
authors.affiliation: Department of Oral Health Sciences, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Natsuko
authors.initials: N
authors.lastname: Tanabe
authors.forename: Naoto
authors.initials: N
authors.lastname: Suzuki
authors.forename: Maiko
authors.initials: M
authors.lastname: Shoji
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Torigoe
authors.forename: Atsuto
authors.initials: A
authors.lastname: Sugaya
authors.forename: Masafumi
authors.initials: M
authors.lastname: Motohashi
authors.forename: Masao
authors.initials: M
authors.lastname: Maeno
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D002113:Calcification, Physiologic / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D017931:DNA Primers; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D006801:Humans; D009538:Nicotine / Q000633:toxicity*; D010012:Osteogenesis / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D017931:DNA Primers; D016326:Extracellular Matrix Proteins; D009538:Nicotine; D000469:Alkaline Phosphatase; D002118:Calcium