title: Dentinogenic capacity: immature root papilla stem cells versus mature root pulp stem cells.
abstract: BACKGROUND
  Immature dental papilla stem cells and mature dental pulp stem cells are capable of performing the dentinogenesis under suitable circumstances. However, a dentinogenic comparison between immature and mature dental root stem cells remains unknown.
  
  
  RESULTS
  iRPSCs (immature root papilla stem cells) at the root-forming stage and mRPSCs (mature root pulp stem cells) at the root-completed stage were isolated from 16-day-old and 8-week-old rat first molar roots, respectively. Growth kinetics and flow cytometry results showed that iRPSCs presented more active proliferation properties than mRPSCs. Their odontoblastic differentiation and dentinogenic potential were subsequently compared both in vitro and in vivo. iRPSCs exhibited a more potent odontoblastic differentiation than mRPSCs in vitro, as indicated by the higher levels of gene expression for dentin sialophosphoprotein and ALP (alkaline phosphatase), increased protein expression of dentin sialoprotein and runt-related transcription factor 2, decreased gene/protein expression for osterix/osteocalcin (osteogenic markers), elevated ALP activity and enhanced calcium deposition in the mineralization-inducing media. Allotransplantation results demonstrated that all iRPSCs pellets in vivo performed typical dentinogenesis, whereas mRPSCs pellets mainly produced bone-like tissues.
  
  
  CONCLUSIONS
  iRPSCs presented stronger dentinogenesis but weaker osteogenesis than did mRPSCs, suggesting that the dentinogenic competence of root mesenchymal stem cells decreases, whereas their osteogenic potential the increases following the maturation of the tooth root.
authors.affiliation: Institute of Stomatology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Lei
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.forename: Zanwei
authors.initials: Z
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu
authors.forename: Chunbo
authors.initials: C
authors.lastname: Tang
authors.forename: Zilu
authors.initials: Z
authors.lastname: Wang
authors.forename: Jinhua
authors.initials: J
authors.lastname: Yu
authors.forename: Guangdong
authors.initials: G
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D003771:Dental Papilla / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D003782:Dental Pulp / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D003810:Dentinogenesis; D018507:Gene Expression Regulation, Developmental; D009804:Odontoblasts / Q000166:cytology / Q000378:metabolism; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D014092:Tooth Root / Q000166:cytology / Q000254:growth & development / Q000378:metabolism
chemical_list: D015675:Osteocalcin