title: Proposing the use of dental pulp stem cells as a suitable biological model of neurofibromatosis type 1.
abstract: OBJECTIVE
  This study aims to propose the dental pulp stem cells (DPSCs) as a model for studying two features related to neurofibromatosis type 1 (NF1), i.e. augmented proliferative capacity and altered osteogenic differentiation.
  
  
  METHODS
  We isolated a DPSC from the pulp of deciduous teeth of a 6-year-old NF1 patient and two other healthy children of similar age. Cell proliferation was assayed by counting with a haemocytometer after successive cell re-plating. In order to compare osteogenic differentiation, we used osteoblast-differentiating medium and quantified alizarin stain, which relates to degree of calcification, and evaluated the expression of osteoblastic markers by reverse transcription polymerase chain reaction (RT-PCR).
  
  
  RESULTS
  The DPSCs isolated from the NF1 patient displayed a greater rate of proliferation when compared to the control cells. Osteogenic differentiation occurred as expected for both NF1 and control, which concerned cell morphology and expression of osteoblast marker genes ALP, BMP2, BMP4, OCN and SPP1. However, alizarin staining denoted a markedly lower calcification level in the cells from the NF1-diagnosed child, considering that less calcium deposits were visualized under light microscopy and a smaller amount of alizarin could be quantified by spectrophotometry after extraction from the stained cells.
  
  
  CONCLUSIONS
  DPSCs seem to be useful as a model for studying NF1 and predicting prognosis of patients, since their in vitro behaviour seems to mimic at least two features of this disorder: higher tendency to develop bone abnormalities and neoplastic cell proliferation.
authors.affiliation: Laboratory of Human Genetics and Cell Therapy, Biology Department, Biological Sciences Institute, Federal University of Juiz de Fora, Juiz de Fora, 36036-900, Brazil.
authors.forename: Paula Nascimento
authors.initials: PN
authors.lastname: Almeida
authors.forename: Gustavo Torres
authors.initials: GT
authors.lastname: Souza
authors.forename: Camila Maurmann
authors.initials: CM
authors.lastname: de Souza
authors.forename: Rafaella Souza Salomão
authors.initials: RS
authors.lastname: de Zanette
authors.forename: Claudinéia Pereira
authors.initials: CP
authors.lastname: Maranduba
authors.forename: João Vitor Paes
authors.initials: JV
authors.lastname: Rettore
authors.forename: Marcelo Oliveira
authors.initials: MO
authors.lastname: de Santos
authors.forename: Antônio Márcio Resende
authors.initials: AM
authors.lastname: do Carmo
authors.forename: Carlos Magno Costa
authors.initials: CM
authors.lastname: da Maranduba
authors.forename: Fernando Sá
authors.initials: FS
authors.lastname: de Silva
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D054425:Chemokine CCL27 / Q000235:genetics / Q000378:metabolism; D002648:Child; D003782:Dental Pulp / Q000473:pathology*; D006801:Humans; D008297:Male; D008954:Models, Biological; D009456:Neurofibromatosis 1 / Q000473:pathology*; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology*; D053495:Osteopontin / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013234:Stem Cells / Q000502:physiology*; D013997:Time Factors
chemical_list: C525718:BMP2 protein, human; C525809:BMP4 protein, human; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; C492276:CCL27 protein, human; D054425:Chemokine CCL27; D012333:RNA, Messenger; D015675:Osteocalcin; D053495:Osteopontin; D000469:Alkaline Phosphatase; D002118:Calcium