title: Inhibition of matrix metalloproteinase-9 activity by doxycycline ameliorates RANK ligand-induced osteoclast differentiation in vitro and in vivo.
abstract: Tetracycline antibiotics, including doxycycli\e (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 osteoclastogenesis. 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.
authors.affiliation: Department of Immunology, Forsyth Institute, Cambridge, MA 02142, USA.
authors.forename: Gilson C N
authors.initials: GC
authors.lastname: Franco
authors.forename: Mikihito
authors.initials: M
authors.lastname: Kajiya
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Kouji
authors.initials: K
authors.lastname: Ohta
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Rosalen
authors.forename: Francisco C
authors.initials: FC
authors.lastname: Groppo
authors.forename: Cory W O
authors.initials: CW
authors.lastname: Ernst
authors.forename: Janie L
authors.initials: JL
authors.lastname: Boyesen
authors.forename: John D
authors.initials: JD
authors.lastname: Bartlett
authors.forename: Philip
authors.initials: P
authors.lastname: Stashenko
authors.forename: Martin A
authors.initials: MA
authors.lastname: Taubman
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Kawai
mesh_terms: D000135:Acid Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015153:Blotting, Western; D001862:Bone Resorption / Q000378:metabolism / Q000473:pathology; D001842:Bone and Bones / Q000378:metabolism; D056657:Cathepsin K / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D004318:Doxycycline / Q000494:pharmacology*; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D051379:Mice; D008807:Mice, Inbred BALB C; D050778:NFATC Transcription Factors / Q000235:genetics / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation; D053245:RANK Ligand / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012886:Skull / Q000378:metabolism / Q000473:pathology*; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D000900:Anti-Bacterial Agents; D007527:Isoenzymes; D061965:Matrix Metalloproteinase Inhibitors; D050778:NFATC Transcription Factors; C494005:Nfatc1 protein, mouse; D053245:RANK Ligand; D012333:RNA, Messenger; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase; D056657:Cathepsin K; C534132:Ctsk protein, mouse; D020780:Matrix Metalloproteinase 9; D004318:Doxycycline