Inhibition of matrix metalloproteinase-9 activity by doxycycline ameliorates RANK ligand-induced osteoclast differentiation in vitro and in vivo

Abstract

Tetracycline antibiotics, including Doxycycline (DOX), have been used to treat bone resorptive diseases, partially because of their activity to suppress osteoclastogenesis induced by receptor activator of nuclear factor kappa B ligand (RANKL). However, their precise inhibitory mechanism remains unclear. Therefore, the present study examined the effect of Dox on osteoclastogenesis signaling induced by RANKL, both in vitro and in vivo. Although Dox inhibited RANKL-induced osteoclastogenesis and down-modulated the mRNA expression of functional osteoclast markers, including tartrate-resistant acid phosphatase (TRAP) and cathepsin K, Dox neither affected RANKL-induced MAPKs phosphorylation nor NFATc1 gene expression in RAW264.7 murine monocytic cells. Gelatin zymography and Western blot analyses showed that Dox down-regulated the enzyme activity of RANKL-induced MMP-9, but without affecting its protein expression. Furthermore, MMP-9 enzyme inhibitor also attenuated both RANKL-induced osteoclastogenesis and up-regulation of TRAP and cathepsin K mRNA expression, indicating that MMP-9 enzyme action is engaged in the promotion of RANKL-induced osteoclstogenesis. Finally, Dox treatment abrogated RANKL-induced osteoclastogenesis and TRAP activity in mouse calvaria along with the suppression of MMP9 enzyme activity, again without affecting the expression of MMP9 protein. These findings suggested that Dox inhibits RANKL-induced osteoclastogenesis by its inhibitory effect on MMP-9 enzyme activity independent of the MAPK-NFATc1 signaling cascade.

Pristimerin, a naturally occurring triterpenoid, protects against autoimmune arthritis by modulating the cellular and soluble immune mediators of inflammation and tissue damage

“…A reduction in MMP-9 activity may limit bone resorption associated with arthritis by decreasing RANKL expression. This association is based on the results of other investigators showing that MMP-9 can induce RANKL activity, and a reduction in MMP-9 can reduce RANKL [35]. Thus, Pristimerin might block this bi-directional cross-talk resulting in protection against bone damage.…”

“…MMPs play an important role in cartilage and bone destruction in arthritic joints [35,36]. These enzymes also participate in the migration of DC to the secondary lymphoid tissue and the site of inflammation [37,38].…”

Celastrus and Its Bioactive Celastrol Protect against Bone Damage in Autoimmune Arthritis by Modulating Osteoimmune Cross-talk

“…Another physiological modulator of RANKL activity is MMP-9, which has been shown to play an important role in bone remodeling (48). For example, MMP-9 activity is involved in the promotion of RANKL-induced osteoclastogenesis independent of NFATc1 signaling (48).…”

“…For example, MMP-9 activity is involved in the promotion of RANKL-induced osteoclastogenesis independent of NFATc1 signaling (48). Furthermore, IL-1␤ can stimulate FLS/osteoclasts and chondrocytes to produce MMPs that degrade cartilage (45).…”

Osteoblastogenesis and osteoprotection enhanced by flavonolignan silibinin in osteoblasts and osteoclasts

“…In addition, silibinin hampered osteoclastogenesis signaling by down-regulated the enzyme activity of RANKL-induced MMP-9. It is shown that MMP-9 enzyme action is engaged in the promotion of RANKL-induced osteoclastogenesis independent of NFATc1 signaling [Franco et al, 2011]. Similarly, the isoflavone genistein down-regulated RANKL production and MMP-9 activity and inhibited osteoclast formation, resulting in the inhibition of osteoclastic bone resorption and prostate cancer bone metastasis [Li et al, 2006].…”