Persistent expression of proto-oncogene c-fos stimulates osteoclast differentiation.
We analyzed c-fos mRNA expression by northern blotting analysis in chicken osteoclast precursors which spontaneously differentiate to multinucleated osteoclasts in 5-6 days. Osteoclast precursors as well as mature multinucleated osteoclasts showed constitutive expression of c-fos mRNA which is not found in osteoblasts. The c-fos expression was enhanced transiently by serum, dibutyryl cAMP (10(-4) M) and phorbol 12-myristate 13-acetate (TPA) (5 x 10(-7) M). To clarify the role of c-fos in osteoclast differentiation, c-fos DNA was transfected into osteoclast precursors. Greater than 2 fold increases in tartrate resistant acid phosphatase (TRAP) and bone resorptive activity were observed in the transfected cells compared to controls 3 days after transfection, suggesting that prolonged expression of c-fos caused enhanced osteoclast differentiation.
Miyauchi
A
A
Department of Medicine, Kobe University School of Medicine, Japan.
Kuroki
Y
Y
Fukase
M
M
Fujita
T
T
Chihara
K
K
Shiozawa
S
S
D000135:Acid Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D016762:Genes, fos; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013644:Tartrates / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
D012333:RNA, Messenger; D013644:Tartrates; D003994:Bucladesine; D004247:DNA; D000135:Acid Phosphatase; D013755:Tetradecanoylphorbol Acetate; C029768:tartaric acid