title: The role of odontogenic genes and proteins in tooth epithelial cells and their niche cells during rat tooth root development.
abstract: OBJECTIVE
  The rodent incisor cervical loop and molar Hertwig's epithelial root sheath (HERS) are common models used for investigating tooth root generation. The purpose of the present study was to gain a better understanding of the molecular mechanisms mediating root development by determining the distinctive gene and protein expression profiles of each during different stages of development.
  
  
  METHODS
  In this study, we used quantitative real time reverse transcription-PCR and immunohistochemistry to analyse the expression levels of high mobility group AT-hook 2, ameloblastin, amelogenin, dentine sialoprotein, dentine matrix protein 1, osteocalcin, and bone sialoprotein in rat epithelial and mesenchymal cells isolated at postnatal days 4 and 8.
  
  
  RESULTS
  Results showed that the expression of these genes and proteins was up-regulated in cervical loop epithelial cells, but decreased or unchanged in other cells during development. This increase in expression in the incisor cervical loop may be due to the interaction of the inner incisor dental papilla cells, which are the niche cells of cervical loop epithelial cells and demonstrated up-regulated expression of the corresponding proteins, revealing a complex and dynamic interplay of these molecules during neonatal tooth development.
  
  
  CONCLUSIONS
  These findings provide novel insights into the molecular processes underlying crown development of rodent incisors, and contribute to our overall understanding of the pathogenic processes of tooth root dysontogenesis.
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, PR China; Department of Oral and Maxillofacial Surgery, West China College of Stomatology, Sichuan University, Chengdu, PR China.
authors.forename: Yaneng
authors.initials: Y
authors.lastname: Ge
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, PR China; Department of Oral and Maxillofacial Surgery, West China College of Stomatology, Sichuan University, Chengdu, PR China.
authors.forename: Ziren
authors.initials: Z
authors.lastname: Kong
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, PR China; Department of Orthodontics, West China College of Stomatology, Sichuan University, Chengdu, PR China.
authors.forename: Yongwen
authors.initials: Y
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, PR China; Department of Oral and Maxillofacial Surgery, West China College of Stomatology, Sichuan University, Chengdu, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, PR China. Electronic address: guoweihua943019@163.com.
authors.forename: Weihua
authors.initials: W
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, PR China; Department of Oral and Maxillofacial Surgery, West China College of Stomatology, Sichuan University, Chengdu, PR China. Electronic address: drtwd@sina.com.
authors.forename: Weidong
authors.initials: W
authors.lastname: Tian
mesh_terms: D053523:Amelogenin / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D018929:Cell Culture Techniques; D003746:Dental Enamel Proteins / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D015870:Gene Expression; D025743:HMGA2 Protein / Q000378:metabolism; D007124:Immunoenzyme Techniques; D007180:Incisor / Q000166:cytology / Q000196:embryology*; D058574:Integrin-Binding Sialoprotein / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000378:metabolism; D009805:Odontogenesis / Q000235:genetics*; D015675:Osteocalcin / Q000378:metabolism; D053495:Osteopontin / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction
chemical_list: C098519:Ambn protein, rat; D053523:Amelogenin; D015415:Biomarkers; D003746:Dental Enamel Proteins; C081635:Dmp1 protein, rat; D016326:Extracellular Matrix Proteins; D025743:HMGA2 Protein; D058574:Integrin-Binding Sialoprotein; D010750:Phosphoproteins; C506897:Spp1 protein, rat; D015675:Osteocalcin; D053495:Osteopontin