title: Interleukin-10 inhibits RANKL-mediated expression of NFATc1 in part via suppression of c-Fos and c-Jun in RAW264.7 cells and mouse bone marrow cells.
abstract: Interleukin-10 (IL-10), an anti-inflammatory cytokine, has been shown to inhibit osteoclast formation and bone resorption in rat and mouse systems. However, the precise intracellular mechanism(s) of this action remains unclear. The aim of this study was to clarify the role of IL-10 in the regulation of critical transcription factors involved in osteoclastogenesis. A RAW264.7 macrophage cell line, which constitutively expressed IL-10 receptor, was differentiated to osteoclasts with stimulation of receptor activator of nuclear factor kappaB ligand (RANKL). IL-10 inhibited the RANKL-induced osteoclastogenesis. IL-10 potently reduced the RANKL-induced expression of NFATc1, c-Jun and c-Fos, which are known to be essential for osteoclastogenesis, in time- and dose-dependent manners. The IL-10-induced inhibition of these transcription factors was observed in the system of mouse bone marrow precursors. Besides these transcription factors, IL-10 also decreased the RANKL-induced expression of NF-kappaB p50 and phosphorylation of JNK. To determine which signaling was critical for the IL-10 effect, we examined the effect of overexpression of NFATc1, c-Fos, and c-Jun on the IL-10-induced inhibition of osteoclastogenesis. As expected, overexpression of NFATc1 abrogated the IL-10-induced inhibition of osteoclastogenesis. Interestingly, overexpression of either c-Fos or c-Jun partially rescued the reduction of RANKL-induced expression of NFATc1 and osteoclastogenesis by IL-10. These data suggest that IL-10 may down-regulate osteoclastogenesis mainly through inhibition of the expression of NFATc1, c-Fos and c-Jun. These findings provide new insight into the inhibitory action of IL-10 on RANKL-mediated osteoclastogenesis.
authors.affiliation: Department of Internal Medicine 1, Faculty of Medicine, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan.
authors.forename: Saad Gad-Kamel
authors.initials: SG
authors.lastname: Mohamed
authors.forename: Eiji
authors.initials: E
authors.lastname: Sugiyama
authors.forename: Kouichiro
authors.initials: K
authors.lastname: Shinoda
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Taki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hounoki
authors.forename: Hekmat Osman
authors.initials: HO
authors.lastname: Abdel-Aziz
authors.forename: Muneharu
authors.initials: M
authors.lastname: Maruyama
authors.forename: Masashi
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ogawa
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Miyahara
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D006801:Humans; D016753:Interleukin-10 / Q000494:pharmacology*; D051379:Mice; D052002:NF-kappa B p50 Subunit / Q000378:metabolism; D050778:NFATC Transcription Factors / Q000235:genetics / Q000378:metabolism*; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D053245:RANK Ligand / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D053701:Receptors, Interleukin-10 / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism
chemical_list: D052002:NF-kappa B p50 Subunit; D050778:NFATC Transcription Factors; C494005:Nfatc1 protein, mouse; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D053245:RANK Ligand; D012333:RNA, Messenger; D053701:Receptors, Interleukin-10; D018808:Transcription Factor AP-1; D016753:Interleukin-10