title: GaAlAs laser-induced pulp mineralization involves dentin matrix protein 1 and osteopontin expression.
abstract: OBJECTIVE
  GaAlAs lasers induce pulp mineralization by promoting reparative dentinogenesis. This study analyzed the expression of dentin matrix protein 1 (DMP1) and osteopontin in GaAlAs laser-irradiated rat molars, to examine the hypothesis that these proteins play a role in the laser-induced reparative dentinogenic process.
  
  
  METHODS
  The mesial surfaces of the upper first molars of 8-week-old Wistar rats were irradiated with a pulsed GaAlAs laser. After 1-14 days, mRNA expression of DMP1 and osteopontin in the coronal pulp was analyzed using real-time PCR. DMP1, osteopontin, and heat shock protein 25 (HSP25) were immunolocalized at 1-21 days.
  
  
  RESULTS
  The pulp exhibited a degenerative zone in its mesial portion on days 1-3, and progressive formation of reparative dentin lined with HSP25-immunoreactive odontoblast-like cells, from day 7 onwards. DMP1 and osteopontin mRNA expression were significantly upregulated on days 1-7 and 3-7, respectively. From day 7 onwards, DMP1 and osteopontin immunoreactivity colocalized along the boundary between the primary and reparative dentin.
  
  
  CONCLUSIONS
  GaAlAs laser irradiation of rat molars induced upregulated DMP1 and osteopontin mRNA expression in the coronal pulp, followed by the formation of reparative dentin and the colocalization of DMP1 and osteopontin immunoreactivity at the site at which this tissue first appeared.
authors: Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors: Y
authors: Y
authors: Shigetani
authors: Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors: N
authors: N
authors: Ohkura
authors: Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors: K
authors: K
authors: Yoshiba
authors: Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors: H
authors: H
authors: Ohshima
authors: Department of Oral Histology, Institute for Dental Science, Matsumoto Dental University, Shiojiri, Nagano, Japan.
authors: A
authors: A
authors: Hosoya
authors: Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors: N
authors: N
authors: Yoshiba
authors: Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.|Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
authors: T
authors: T
authors: Okiji
mesh_terms: D000818:Animals; D003782:Dental Pulp / Q000166:cytology / Q000502:physiology; D003809:Dentin, Secondary / Q000378:metabolism* / Q000528:radiation effects*; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis* / Q000528:radiation effects; D055551:HSP27 Heat-Shock Proteins / Q000096:biosynthesis; D007150:Immunohistochemistry; D054023:Lasers, Semiconductor; D008297:Male; D008963:Molar / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D009804:Odontoblasts / Q000378:metabolism / Q000528:radiation effects; D053495:Osteopontin / Q000096:biosynthesis* / Q000528:radiation effects; D010750:Phosphoproteins / Q000096:biosynthesis* / Q000528:radiation effects; D051381:Rats; D017208:Rats, Wistar; D015854:Up-Regulation / Q000528:radiation effects
chemical_list: C081635:Dmp1 protein, rat; D016326:Extracellular Matrix Proteins; D055551:HSP27 Heat-Shock Proteins; C486114:Hspb1 protein, rat; D010750:Phosphoproteins; C506897:Spp1 protein, rat; D053495:Osteopontin
keywords: calcification; dental pulp; dentin matrix protein 1; laser; osteopontin; rats (Wistar)