title: Enamel matrix derivative inhibits TNF-alpha-induced apoptosis in osteoblastic MC3T3-E1 cells.
abstract: OBJECTIVE
  The purpose of this study was to examine the effect of enamel matrix derivative (EMD) on TNF-alpha-induced apoptosis in osteoblastic MC3T3-E1 cells.
  
  
  METHODS
  MC3T3-E1 cells were cultured at an initial density of 5000/cm 2 in Dulbecco's modified eagle medium (DMEM) with 10% fetal bovine serum (FBS) and allowed to adhere for 24 hours. Medium was then changed into DMEM with 0.5% FBS. After 16 hours, cells were treated with EMD (100 microg/mL) alone, tumor necrosis factor alpha (TNF-alpha) (20 ng/mL) alone, transforming growth factor beta 1 (TGF-beta1) (10 ng/mL) alone, TNF-alpha plus TGF-beta1, or TNF-alpha plus EMD. Cells cultured with DMEM and 0.5% FBS served as control. Following 24-hour incubation, apoptosis was assessed by terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) assay, and quantified by cell death enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  Both TUNEL assay and cell death ELISA show that TNF-alpha induces apoptosis in MC3T3-E1 cells. TNF-alpha increases cell death by approximately 2-fold, which is attenuated by both EMD and TGF-beta1.
  
  
  CONCLUSIONS
  Like TGF-beta1, EMD protects osteoblasts from inflammation-induced apoptosis.
authors.affiliation: Department of Endodontics, Baylor College of Dentistry, Dallas, Tex., USA.
authors.forename: Jianing
authors.initials: J
authors.lastname: He
authors.forename: Yiming
authors.initials: Y
authors.lastname: King
authors.forename: Jin
authors.initials: J
authors.lastname: Jiang
authors.forename: Kamran E
authors.initials: KE
authors.lastname: Safavi
authors.forename: Larz S W
authors.initials: LS
authors.lastname: Spångberg
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhu
mesh_terms: D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D003746:Dental Enamel Proteins / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D020287:In Situ Nick-End Labeling; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D003746:Dental Enamel Proteins; C508961:Tgfb1 protein, mouse; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha; C109069:enamel matrix proteins