Spatial and temporal expression of KLF4 and KLF5 during murine tooth development.
OBJECTIVE
KLF4 and KLF5, members of the Krüppel-like factor (KLF) family, play key roles in proliferation, differentiation and apoptosis during development. In order to determine if these transcription factors are associated with tooth development, we examined the expression pattern of KLF4 and KLF5 during murine tooth development.


METHODS
In situ hybridization and immunohistochemistry were performed to detect the expression pattern of KLF4 and KLF5 from E12.5 to PN3 during murine tooth development.


RESULTS
In situ hybridization analysis revealed that Klf4 was specifically expressed in polarizing odontoblasts from E16.5 (incisor) or E18.5 (first molar) to PN3. Immunohistochemistry staining showed that KLF4 was specifically expressed in both polarizing odontoblasts and ameloblasts at the same stages. KLF5 was mainly expressed from E18.5 to PN3 in secretory ameloblasts when enamel mineralization occurs and in secretory odontoblasts. However, an expression of KLF5 was also observed at earlier stages (E14.5 and E16.5) mainly in proliferating epithelial cells.


CONCLUSIONS
These results suggest that the expression of KLF4 is closely correlated to the growth-arrest and the first step of odontoblast and ameloblast differentiation. Furthermore, KLF5 maybe involved in proliferation at the early stages of tooth development and related to mineralization of both enamel and dentin matrices at later stages.
Chen
Zhuo
Z
Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, PR China. timezone95@hotmail.com
Couble
Marie-Lise
ML
Mouterfi
Nassima
N
Magloire
Henry
H
Chen
Zhi
Z
Bleicher
Françoise
F
D000565:Ameloblasts / Q000502:physiology; D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D003743:Dental Enamel / Q000166:cytology / Q000196:embryology; D003782:Dental Pulp / Q000166:cytology / Q000196:embryology; D003804:Dentin / Q000166:cytology / Q000196:embryology; D004847:Epithelial Cells / Q000166:cytology; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D006131:Growth Inhibitors / Q000032:analysis* / Q000235:genetics; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007180:Incisor / Q000166:cytology / Q000196:embryology; D019394:Ki-67 Antigen / Q000032:analysis / Q000235:genetics; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000032:analysis* / Q000235:genetics; D051379:Mice; D008963:Molar / Q000166:cytology / Q000196:embryology; D009804:Odontoblasts / Q000166:cytology; D009805:Odontogenesis / Q000235:genetics*; D013997:Time Factors; D014074:Tooth Calcification / Q000235:genetics; D014083:Tooth Germ / Q000196:embryology; D016335:Zinc Fingers / Q000235:genetics*
D006131:Growth Inhibitors; D019394:Ki-67 Antigen; C000715468:Klf4 protein, mouse; C118391:Klf5 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; C498355:Mki67 protein, mouse