title: [Expression of wingless-type MMTV integration site family member 3 in rat dental follicle tissues and cells undergoing osteogenic differentiation].
abstract: OBJECTIVE
  To investigate the expression of wingless-type MMTV integration site family, member 3 (Wnt3) in rat dental follicles and its protein level in dental follicle cells (DFC) undergoing osteogenic induction and to discuss the effects of Wnt3 on the differentiation of DFC.
  
  
  METHODS
  Rats at postnatal days 1, 3, 5, 7, 9, 11 and 13 were executed, then the mandibles were immediately removed and immunohistochemistry was performed to detect the expression of Wnt3 in dental follicles of postnatal rats. The expression and distribution of Wnt3 in DFC were determined by immunofluorescence. Alizarin red-S staining was performed to assess the mineralization of DFC. Western blotting was used to evaluate Wnt3 and β-catenin protein levels after stimulated by osteogenic medium for 1, 2 and 3 weeks, respectively.
  
  
  RESULTS
  Immunohistochemistry revealed that the expression of Wnt3 in rat dental follicles began at day 5 and sustained to day 13. On day 1 and 3, the expression of Wnt3 in dental follicles was negative.Wnt3 was expressed in the cytoplasm of DFC. Alizarin red-S staining indicated that the osteogenic medium stimulated the differentiation of DFC into osteoblastic lineage.Western blotting demonstrated that the Wnt3 protein levels were significantly up-regulated after stimulated with osteogenic medium for 1 weeks compared with the control (2.60 ± 0.04 vs.1.00 ± 0.00, P < 0.05). Then the levels of Wnt3 protein were declined, and at the 3rd week, no significant difference was observed between osteo-induced group and the control (1.00 ± 0.05 vs.1.00 ± 0.00, P > 0.05). The levels of β-catenin were increased in osteo-induced groups compared with the control (1.95 ± 0.05 vs.1.00 ± 0.00, P < 0.05; 9.77 ± 0.65 vs.1.00 ± 0.00, P < 0.05;1.75 ± 0.21 vs.1.00 ± 0.00, P < 0.05). Furthermore, the expression of β-catenin reached to a peak on the 2nd week (9.77 ± 0.65), and then declined.
  
  
  CONCLUSIONS
  Wnt3 was expressed in the rat dental follicles both in vivo and in vitro and up-regulated during early phase of osteoblast differentiation in DFC.Wnt3 may be involved in early phase of osteoblast differentiation.
authors.affiliation: Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University & Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Yu
authors.initials: Y
authors.lastname: Du
authors.forename: Jun-qi
authors.initials: JQ
authors.lastname: Ling
authors.forename: Lu-sai
authors.initials: LS
authors.lastname: Xiang
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D003795:Dental Sac / Q000166:cytology / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D015854:Up-Regulation; D060508:Wnt3 Protein / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism
chemical_list: D060508:Wnt3 Protein; C555509:Wnt3 protein, rat; D051176:beta Catenin; D012710:Serum Albumin, Bovine