Inhibitory effect of minocycline on osteoclastogenesis in mouse bone marrow cells.

摘要

OBJECTIVE: To study the effects of minocycline hydrochloride (MINO) on the formation of tartrate-resistant acid phosphatase (TRAP) staining-positive multinucleated osteoclast-like cells in mouse bone marrow cells (BMCs) treated with 1alpha,25(OH)(2)D(3) or soluble receptor activator of nuclear factor-kappaB ligand (s-RANKL). MATERIALS AND METHODS: Mouse BMCs were cultured in alpha-modified minimum essential medium containing foetal calf serum (10%) and tetracyclines (2.5, 5 and 10muM), such as MINO, tetracycline hydrochloride (TC), oxytetracycline hydrochloride (OXT) or doxycycline (DOXY) in the presence of 1alpha,25(OH)(2)D(3) (10nM) or s-RANKL (20ng/ml) for 7 days, and the number of TRAP staining-positive osteoclast-like cells was counted. In RNA isolated from BMCs treated with 1alpha,25(OH)(2)D(3) or s-RANKL in the presence or absence of MINO, the expressions of osteoclast differentiation relating to mRNA were analysed by reverse transcription-polymerase chain reaction. Cell viability was examined in mouse BMCs and rabbit osteoclasts treated with MINO (0.25-20muM and 2-50muM, respectively) for 24h. RESULTS: MINO, TC, OXT or DOXY inhibited 1alpha,25(OH)(2)D(3)-induced osteoclast-like cell formation in mouse BMCs dose dependently. MINO suppressed 1alpha,25(OH)(2)D(3)-induced up-regulation of mRNA expressions of TRAP, cathepsin K, carbonic anhydrase II, and calcitonin receptor, but not RANKL. MINO inhibited s-RANKL-induced osteoclast-like cell formation and up-regulation of mRNA expressions for nuclear factor of activated T-cells c1 (NFATc1), a key regulator of osteoclast differentiation; however, MINO had no effects on the viability of mouse BMCs and rabbit osteoclasts. CONCLUSION: MINO inhibits RANKL-induced osteoclastogenesis via down-regulation of NFATc1 mRNA expression in osteoclast precursor cells.