TY - JOUR
T1 - The immunosuppressant rapamycin, alone or with transforming growth factor-β, enhances osteoclast differentiation of RAW264.7 Monocyte-macrophage cells in the presence of RANK-ligand
AU - Shui, C.
AU - Riggs, B. L.
AU - Khosla, S.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/11/1
Y1 - 2002/11/1
N2 - Immunosuppressant therapy is known to cause bone loss. Since this may partly result from direct effects on osteoclast development, we investigated whether cyclosporin A (CsA), rapamycin, or FK506 affect osteoclastic differentiation of RAW264.7 monocytic cells induced by RANK-ligand (RANKL). Furthermore, since the rapamycin receptor protein binds transforming growth factor β (TGF-β) receptors, and TGF-β enhances osteoclastogenesis induced by RANKL, we also examined potential synergistic effects of rapamycin and TGF-β1. Rapamycin inhibited cell proliferation and stimulated tartrate-resistant acid phosphatase (TRAP) activity of RAW cells in a dose-dependent manner. At the optimal concentration of 10 ng/ml, it increased the number of TRAP+ multinucleated cells (MNC) more than 20-fold and enhanced the expression of TRAP and calcitonin receptor (CTR) mRNAs 2.1- and 10-fold, respectively. CsA, at 125-2000 ng/ml, similarly inhibited proliferation, but at high doses (1000-2000 ng/ml) it decreased TRAP activity, TRAP+MNC formation, and the expression of TRAP and CTR mRNAs. FK506 had no effect on cell proliferation or TRAP activity at concentrations up to 2000 ng/ml; however, like CsA, 1000 ng/ml FK506 inhibited TRAP+MNC formation and the expression of TRAP and CTR mRNAs. The combination of rapamycin (10 ng/ml) and TGF-β1(1 ng/ml) increased TRAP+MNC 3.1- and 6.9-fold as compared with rapamycin or TGF-β1 alone, respectively, and enhanced CTR mRNA expression induced by TGF-β1 by 1.9-fold. Rapamycin also increased osteoclastic resorption activity by 6.5-fold compared with control, and this was enhanced further by the addition of TGF-β by 3-fold, compared with rapamycin alone. These data thus indicate that rapamycin, alone or in synergy with TGF-β, directly enhances osteoclastogenesis and may affect bone metabolism in vivo after long-term use.
AB - Immunosuppressant therapy is known to cause bone loss. Since this may partly result from direct effects on osteoclast development, we investigated whether cyclosporin A (CsA), rapamycin, or FK506 affect osteoclastic differentiation of RAW264.7 monocytic cells induced by RANK-ligand (RANKL). Furthermore, since the rapamycin receptor protein binds transforming growth factor β (TGF-β) receptors, and TGF-β enhances osteoclastogenesis induced by RANKL, we also examined potential synergistic effects of rapamycin and TGF-β1. Rapamycin inhibited cell proliferation and stimulated tartrate-resistant acid phosphatase (TRAP) activity of RAW cells in a dose-dependent manner. At the optimal concentration of 10 ng/ml, it increased the number of TRAP+ multinucleated cells (MNC) more than 20-fold and enhanced the expression of TRAP and calcitonin receptor (CTR) mRNAs 2.1- and 10-fold, respectively. CsA, at 125-2000 ng/ml, similarly inhibited proliferation, but at high doses (1000-2000 ng/ml) it decreased TRAP activity, TRAP+MNC formation, and the expression of TRAP and CTR mRNAs. FK506 had no effect on cell proliferation or TRAP activity at concentrations up to 2000 ng/ml; however, like CsA, 1000 ng/ml FK506 inhibited TRAP+MNC formation and the expression of TRAP and CTR mRNAs. The combination of rapamycin (10 ng/ml) and TGF-β1(1 ng/ml) increased TRAP+MNC 3.1- and 6.9-fold as compared with rapamycin or TGF-β1 alone, respectively, and enhanced CTR mRNA expression induced by TGF-β1 by 1.9-fold. Rapamycin also increased osteoclastic resorption activity by 6.5-fold compared with control, and this was enhanced further by the addition of TGF-β by 3-fold, compared with rapamycin alone. These data thus indicate that rapamycin, alone or in synergy with TGF-β, directly enhances osteoclastogenesis and may affect bone metabolism in vivo after long-term use.
KW - Immunosuppressant
KW - Osteoclast
KW - RANK-ligand
KW - Transforming growth factor β
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U2 - 10.1007/s00223-001-1138-3
DO - 10.1007/s00223-001-1138-3
M3 - Article
C2 - 12202955
AN - SCOPUS:0041663764
SN - 0171-967X
VL - 71
SP - 437
EP - 446
JO - Calcified Tissue International
JF - Calcified Tissue International
IS - 5
ER -