title: In vitro biologic response of human bone marrow stromal cells to enamel matrix derivative.
abstract: BACKGROUND
  In vitro investigations suggest that enamel matrix derivative (EMD) may affect the biologic response of periodontal-related cells, including osteoblasts and their precursors, the bone marrow stromal cells (BMSCs), which could play a crucial role in the regenerative process. In this study, we investigated the effects of EMD on human BMSCs.
  
  
  METHODS
  Primary cultures of BMSCs were obtained from bone marrow samples of healthy donors. Cell proliferation and osteogenic marker expression in response to serial dilutions of EMD (12.5, 25, and 50 microg/ml) were assessed. Cell growth was measured by 3H-thymidine incorporation and type I collagen synthesis by immunoblotting. Alkaline phosphatase (AP)-specific activity in the early phase (7 days), in vitro mineralization by von Kossa staining and calcium quantification, and osteocalcin levels at prolonged times (3 weeks) also were evaluated.
  
  
  RESULTS
  EMD stimulated BMSC growth in a dose-dependent manner. When EMD 50 microg/ml was followed over time, the highest proliferative effect was evident at 24 hours (3.4-fold of the control). Type I collagen level was significantly lower than the control after a 7-day incubation with EMD 50 microg/ml. AP activity was reduced in a dose-dependent manner down to 55% of the control. Also, the extracellular matrix mineralization decreased in EMD-treated cells with respect to the control, whereas only a slight, not significant, decrease in osteocalcin levels was found.
  
  
  CONCLUSIONS
  EMD significantly increased BMSC growth and simultaneously decreased their osteogenic differentiation. The clinical efficacy of EMD in regenerating periodontal tissues can be attributed, in part, to the biologic effects exerted on the bone marrow stromal component of resident cells.
authors.affiliation: Department of Odontostomatological, Orthodontic and Surgical Disciplines, Second University of Naples, Naples, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Guida
authors.forename: Marco
authors.initials: M
authors.lastname: Annunziata
authors.forename: Francesco
authors.initials: F
authors.lastname: Carinci
authors.forename: Angelo
authors.initials: A
authors.lastname: Di Feo
authors.forename: Irene
authors.initials: I
authors.lastname: Passaro
authors.forename: Adriana
authors.initials: A
authors.lastname: Oliva
mesh_terms: D000328:Adult; D001854:Bone Marrow Cells / Q000166:cytology*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003094:Collagen / Q000032:analysis / Q000096:biosynthesis; D003746:Dental Enamel Proteins / Q000494:pharmacology*; D003764:Dental Materials / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D015675:Osteocalcin / Q000032:analysis; D017154:Stromal Cells / Q000187:drug effects
chemical_list: D003746:Dental Enamel Proteins; D003764:Dental Materials; C109069:enamel matrix proteins; D015675:Osteocalcin; D003094:Collagen