title: Effects of enamel matrix derivative and transforming growth factor-β1 on connective tissue growth factor in human periodontal ligament fibroblasts.
abstract: BACKGROUND
  Enamel matrix derivative (EMD) is suggested to stimulate transforming growth factor-β (TGF-β) production. Connective tissue growth factor (CTGF) is a downstream mediator of TGF-β. This study explores the effects of EMD and TGF-β1 on CTGF in periodontal ligament (PDL) fibroblasts and their interactions in PDL proliferation and development.
  
  
  METHODS
  Human PDL cells were stimulated with EMD. To explore the effects of EMD and TGF-β1 on CTGF expression, cells were treated with and without TGF-β inhibitor, and CTGF protein levels were assayed by Western blot analysis. To study the role of CTGF in PDL development, cells were treated with CTGF inhibitor. DNA synthesis was analyzed by bromodeoxyuridine enzyme-linked immunosorbent assay. Reverse-transcription polymerase chain reaction was performed to examine messenger RNA expression of PDL osteoblastic differentiation markers: type I collagen, alkaline phosphatase, and osteocalcin.
  
  
  RESULTS
  EMD induced a concentration-dependent increase of CTGF protein expression in PDL cells. EMD- and TGF-β1-stimulated CTGF expression was significantly reduced in the presence of TGF-β inhibitor. CTGF inhibition downregulated both EMD- and TGF-β1-induced DNA synthesis. The effect of CTGF and EMD on osteoblastic mRNA expression in PDL cells is not obvious.
  
  
  CONCLUSIONS
  EMD stimulates CTGF expression in human PDL cells, a process modulated by the TGF-β pathway. CTGF can affect EMD- and TGF-β1-induced PDL cell proliferation, but its effects on PDL with regard to osteoblastic differentiation remain inconclusive. The results provide novel insights into EMD-CTGF interaction in PDL cells.
authors.affiliation: Clinical Research, National Dental Center, Singapore.
authors.forename: Nora H M
authors.initials: NH
authors.lastname: Heng
authors.forename: Janine
authors.initials: J
authors.lastname: Zahlten
authors.forename: Valerie
authors.initials: V
authors.lastname: Cordes
authors.forename: Marianne M-A
authors.initials: MM
authors.lastname: Ong
authors.forename: Bee Tin
authors.initials: BT
authors.lastname: Goh
authors.forename: Philippe D
authors.initials: PD
authors.lastname: N'Guessan
authors.forename: Nicole
authors.initials: N
authors.lastname: Pischon
mesh_terms: D000293:Adolescent; D000328:Adult; D000469:Alkaline Phosphatase / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D024042:Collagen Type I / Q000187:drug effects; D055513:Connective Tissue Growth Factor / Q000037:antagonists & inhibitors / Q000187:drug effects*; D004247:DNA / Q000187:drug effects; D003746:Dental Enamel Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005347:Fibroblasts / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010006:Osteoblasts / Q000187:drug effects; D015675:Osteocalcin / Q000187:drug effects; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects*; D012333:RNA, Messenger / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D055815:Young Adult
chemical_list: C526317:CCN2 protein, human; D024042:Collagen Type I; D003746:Dental Enamel Proteins; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; C109069:enamel matrix proteins; D015675:Osteocalcin; D055513:Connective Tissue Growth Factor; D004247:DNA; D000469:Alkaline Phosphatase
keywords: Connective tissue growth factor; enamel matrix proteins; guided periodontal tissue regeneration, tissue engineering; periodontal ligament; transforming growth factor beta