Effects of epidermal growth factor (EGF) and colony-stimulating factor-1 (CSF-1) on expression of c-fos in rat mandibular molars: implications for tooth eruption.
The c-fos gene is expressed in the dental follicle of the first mandibular molar of rats. Molecules that accelerate tooth eruption, epidermal growth factor (EGF) and colony-stimulating factor-1 (CSF-1), enhance the expression of the c-fos gene in vitro in both a time- and concentration-dependent manner. In vivo, EGF enhances c-fos expression in the follicle from day 0-7 postnatally, but by day 9 the follicle is refractory to this stimulus. Immunostaining reveals that the c-fos gene is translated in the cultured dental follicle cells, with staining seen in the nucleus and the perinuclear region of the cytoplasm. In vivo, immunostaining for c-fos is prominent in the dental follicle early postnatally, with little or no staining seen in the stellate reticulum and dental pulp. By day 10 postnatally, staining for c-fos is greatly reduced in the dental follicle. Thus, the presence of c-fos early postnatally in the tissue required for eruption, the dental follicle, as well as the enhancement of c-fos gene expression in the follicle by EGF or CSF-1, suggests that c-fos plays a role in tooth eruption. That role may be either to promote differentiation of mononuclear cells into osteoclasts needed for eruption or to recruit the mononuclear cells into the follicle.
Wise
G E
GE
Department of Veterinary Anatomy and Cell Biology, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA.
Zhao
L
L
Lin
F
F
D000818:Animals; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D016762:Genes, fos / Q000235:genetics*; D007150:Immunohistochemistry; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D008334:Mandible; D008963:Molar / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D014078:Tooth Eruption / Q000502:physiology
D004815:Epidermal Growth Factor; D016173:Macrophage Colony-Stimulating Factor