Although steroids have an inhibitory effect on inflammation and immune response, osteoporosis is a side effect, so prophylactic concomitant use of osteoporosis therapeutic agents is recommended for adults.However, in the case of children, there is a risk of bone growth failure, and a new therapeutic drug for steroid-induced osteoporosis that can be safely used together was needed.

　Siglec 15 is one of the immunoreceptor-type membrane proteins that regulates the final differentiation of osteoclasts.Mice lacking this gene show an osteopetrosis-like phenotype due to osteoclast differentiation deficiency, but do not cause failure to thrive.This is because there is a compensatory pathway for Siglec 15 near the growth zone and normal osteoclasts are formed.Focusing on this characteristic, the research group has reported the therapeutic potential of osteoporosis that does not interfere with bone growth with Siglec 15 neutralizing antibody.

　In this study, Siglec 15 antibody or bisphosphonate, a typical osteoporosis treatment drug, was administered to growing rats treated with steroids, and their effects were investigated.As a result, the Siglec 15 neutralizing antibody was more effective in increasing bone mass, and no abnormality was observed in bone growth.This is because bisphosphonate reduces both osteoclasts and osteoblasts and suppresses bone metabolism, but Cigrec 15 antibody suppresses only the final differentiation of osteoclasts and does not reduce osteoblasts, and bone metabolism to some extent. It seems that it is to suppress bone loss while maintaining.

　In the future, it is expected to be an effective osteoporosis prevention method when using steroids for children suffering from childhood cancer, autoimmune diseases, nephrotic syndrome, etc.

Paper information:[BONE] Siglec-15-targeting therapy protects against glucocorticoid-induced osteoporosis of growing skeleton in juvenile rats