title: Differential effects of amelogenin on mineralization of cementoblasts and periodontal ligament cells.
abstract: BACKGROUND
  Amelogenin is a major component of developing extracellular enamel matrix proteins and plays a crucial role during the formation of tooth enamel. In addition, amelogenins are suggested to exert biologic functions as signaling molecules through cell-surface receptors. The purpose of this study is to examine the effect of recombinant human full-length amelogenin (rh174) on the mineralization of human cementoblasts (HCEMs) and human periodontal ligament cells (HPDLs).
  
  
  METHODS
  HCEMs, namely, a cell line immortalized by transfection of human telomerase reverse transcription gene, and HPDLs isolated from human first premolars were cultured and treated with 0 to 1,000 ng/mL rh174. The messenger ribonucleic acid (mRNA) levels of alkaline phosphatase (ALP), osteocalcin (OCN), and bone sialoprotein (BSP) were examined by real-time polymerase chain reaction analysis. The protein levels of OCN and BSP were examined by Western blot analysis. ALP activity and calcium deposition of cell cultures were also determined. Mineralization of cells was evaluated by red dye staining.
  
  
  RESULTS
  The treatment of HCEMs with rh174 upregulated the ALP, OCN, and BSP mRNA levels. In addition, the protein levels of OCN and BSP, ALP activity, and calcium deposition were enhanced, resulting in enhanced mineralization. Conversely, there were no significant effects of rh174 on the mineralization of HPDLs.
  
  
  CONCLUSIONS
  The present study shows that rh174 enhances mineralization accompanied by upregulation of mineralization markers in HCEMs, whereas it has no effect on that in HPDLs, suggesting different effects of amelogenin on PDL and cementum.
authors.affiliation: Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, Minami-ku, Hiroshima, Japan. tkotaro@hiroshima-u.ac.jp
authors.forename: Kotaro
authors.initials: K
authors.lastname: Tanimoto
authors.forename: Ryo
authors.initials: R
authors.lastname: Kunimatsu
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tanne
authors.forename: Yu-Ching
authors.initials: YC
authors.lastname: Huang
authors.forename: Masahiko
authors.initials: M
authors.lastname: Michida
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yoshimi
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Miyauchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Takata
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tanne
mesh_terms: D000469:Alkaline Phosphatase / Q000096:biosynthesis / Q000235:genetics; D053523:Amelogenin / Q000494:pharmacology* / Q000502:physiology; D000704:Analysis of Variance; D002461:Cell Line, Transformed; D003739:Dental Cementum / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D058574:Integrin-Binding Sialoprotein / Q000096:biosynthesis / Q000235:genetics; D015675:Osteocalcin / Q000096:biosynthesis / Q000235:genetics; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D011994:Recombinant Proteins / Q000494:pharmacology; D018709:Statistics, Nonparametric; D014074:Tooth Calcification / Q000187:drug effects* / Q000502:physiology; D015854:Up-Regulation
chemical_list: D053523:Amelogenin; D058574:Integrin-Binding Sialoprotein; D011994:Recombinant Proteins; D015675:Osteocalcin; D000469:Alkaline Phosphatase