[Inhibitory effects of cytokines on human osteoblastic cells].
We examined the effect of tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta (IL-1 beta) and IL-6 on alkaline phosphatase (ALP) and osteocalcin (OC) production, calcification and calcium (Ca) release in human cultured osteoblastic cells established from human periosteum. The cells were cultured with varying concentrations of cytokines for three days. TNF-alpha and IL-1 beta significantly inhibited ALP production, decreased cellular Ca content, and significantly enhanced 45Ca release in human osteoblastic cells. IL-6, on the other hand, significantly suppressed 45Ca release from the osteoblastic cells. Any one of these cytokines did not influence the production of OC by the osteoblastic cells. The results obtained suggest that TNF-alpha and IL-1 beta may inhibit bone formation and calcification and promote bone resorption, while the effects of IL-6 on osteoblastic cells may be a little different from those of TNF-alpha or IL-1 beta. Cytokine-dependent these effects on the osteoblastic cells may be one of the mechanisms by which bone loss occurs in patients with rheumatoid arthritis.
Department of Clinical Immunology, Kyushu University.
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Kuroki
D000469:Alkaline Phosphatase / Q000378:metabolism; D002114:Calcinosis; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology*; D006801:Humans; D010006:Osteoblasts / Q000378:metabolism* / Q000473:pathology; D015675:Osteocalcin / Q000378:metabolism
D016207:Cytokines; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D002118:Calcium