Effect of CSF-1 on in vivo expression of c-fos in the dental follicle during tooth eruption.
It has been demonstrated that both colony-stimulating factor-one (CSF-1) and the transcription factor, c-fos are required for tooth eruption. Osteopetrotic mutant rats deficient in CSF-1 activity have unerupted teeth which can be induced to erupt by injections of CSF-1, and osteopetrotic mice deficient in c-fos, have unerupted teeth. Both CSF-1 and c-fos are expressed and translated in the dental follicle, the tissue that is required for eruption. Recent in vitro studies indicate that CSF-1 can enhance the expression of the c-fos gene in cultured dental follicle cells, but the effects in vivo are not known. In the present studies. postnatal rats were injected with 10(6) units of CSF-1 at different ages from birth to day 10 and sacrificed 30 min after injection. Isolation of total RNA from the follicle and reverse transcription PCR showed that CSF-1 injection enhanced the expression of c-fos over the non-injected controls. Chronologically, day 3 postnatally appeared to show the greatest increase of c-fos mRNA following CSF-1 injection. These results suggest that one of the functions of CSF-1 in tooth eruption is to enhance the early expression of c-fos. In turn, c-fos might act to promote fusion of monocytes into the osteoclasts needed for alveolar bone resorption and tooth eruption.
Wise
G E
GE
Department of Veterinary Anatomy and Cell Biology, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803, USA. wise_g@vt8200.vetmed.lsu.edu
Marks
S C
SC
Zhao
L
L
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D003795:Dental Sac / Q000187:drug effects* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D016762:Genes, fos / Q000187:drug effects*; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology* / Q000502:physiology; D051379:Mice; D016133:Polymerase Chain Reaction; D016760:Proto-Oncogene Proteins c-fos / Q000172:deficiency / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014078:Tooth Eruption / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology
D017931:DNA Primers; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D016173:Macrophage Colony-Stimulating Factor