抄録
Osteoclasts are multinucleated giant cells responsible for bone resorption. Recent progress in molecular biology has revealed the molecular mechanism of osteoclast differentiation and osteoclastic bone resorption. Investigation on osteopetrotic (op/op) mice showed that macrophage colony-stimulating factor (M-CSF) is essential for osteoclast differentiation. The receptor of M-CSF is encoded by c-fms protooncogene and a member of receptor tyrosine kinase, suggesting that signaling of tyrosine kinase is important for osteoclast differentiation. Osteoclasts of c-src knock-out mice have remarkable deficiency in bone resorbing activity, indi cating that c-src is important for osteoclastic function. c-src encodes nonreceptor tyrosine kinase c-src, indicating that signaling of c-src tyrosine kinase is essential for osteoclast activity. Further investigation on tyrosine kinase signaling pathways will contribute to understanding of the regulatory mechanism of bone resorption.
