Cytokines and osteoporosis.
Bone remodeling is a complex process that involves cells from various lineages, the calcified extracellular bone matrix and a multitude of regulation factors that act at both the tissular and cellular levels. Resorption and formation of bone are regulated at various levels during the series of events that lead from stem cell proliferation to differentiation of mature cells. These events are controlled by calciotropic hormones, whose indirect cellular effects are mediated by the production of local factors. A host of cytokines and growth factors influence the proliferation and differentiation of bone cells, and their activities are modulated by a large number of hormones. Resorption by osteoclasts is regulated at various stages of the differentiation process by cytokines produced by osteoblasts or stromal cells. Experimental studies in mice suggest that these local factors play a role in postoophorectomy bone loss, although their exact mechanisms of action are not known. Evidence that these factors are involved in postmenopausal bone loss is beginning to accumulate, opening up a vast field of investigation.
Cohen-Solal
M
M
de Vernejoul
M C
MC
D000818:Animals; D016723:Bone Remodeling / Q000502:physiology; D001862:Bone Resorption / Q000209:etiology; D002455:Cell Division; D016207:Cytokines / Q000378:metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D010024:Osteoporosis / Q000209:etiology* / Q000378:metabolism
D016207:Cytokines