title: Porcine enamel protein fractions contain transforming growth factor-beta1.
abstract: BACKGROUND
  Enamel extracts are biologically active and capable of inducing osteogenesis and cementogenesis, but the specific molecules carrying these activities have not been ascertained. The purpose of this study was to identify osteogenic factors in porcine enamel extracts.
  
  
  METHODS
  Enamel proteins were separated by size-exclusion chromatography into four fractions, which were tested for their osteogenic activity on osteoblast-like cells (ST2) and human periodontal ligament (HPDL) cells.
  
  
  RESULTS
  Fraction 3 (Fr.3) and a transforming growth factor-beta 1 (TGF-beta1) control reduced alkaline phosphatase (ALP) activity in ST2 but enhanced ALP activity in HPDL cells. The enhanced ALP activity was blocked by anti-TGF-beta antibodies. Furthermore, using a dual-luciferase reporter assay, we demonstrated that Fr.3 can induce the promoter activity of the plasminogen activator inhibitor type 1 (PAI-1) gene.
  
  
  CONCLUSIONS
  These results show that the osteoinductive activity of enamel extracts on HPDL cells is mediated by TGF-beta1.
authors.affiliation: Department of Periodontics and Endodontics, School of Dental Medicine, Tsurumi University, Yokohama, Japan. nagano-takatoshi@tsurumi-u.ac.jp
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Nagano
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Oida
authors.forename: Shinichi
authors.initials: S
authors.lastname: Suzuki
authors.forename: Takanori
authors.initials: T
authors.lastname: Iwata
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yamakoshi
authors.forename: Yorimasa
authors.initials: Y
authors.lastname: Ogata
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Gomi
authors.forename: Takashi
authors.initials: T
authors.lastname: Arai
authors.forename: Makoto
authors.initials: M
authors.lastname: Fukae
mesh_terms: D000469:Alkaline Phosphatase / Q000187:drug effects; D000818:Animals; D002478:Cells, Cultured; D003746:Dental Enamel Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D008934:Mitogens / Q000494:pharmacology; D010006:Osteoblasts / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000187:drug effects; D013552:Swine; D014020:Tissue Extracts; D053773:Transforming Growth Factor beta1 / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D003746:Dental Enamel Proteins; D008934:Mitogens; D017395:Plasminogen Activator Inhibitor 1; D014020:Tissue Extracts; D053773:Transforming Growth Factor beta1; D000469:Alkaline Phosphatase