title: Iguratimod (T-614) suppresses RANKL-induced osteoclast differentiation and migration in RAW264.7 cells via NF-κB and MAPK pathways.
abstract: BACKGROUND
  Iguratimod (T-614) has been confirmed as a highly efficacious and safe novel disease-modifying anti-rheumatic drug (DMARD) for rheumatoid arthritis therapy in China and Japan due to its potent anti-inflammation effect. Here, we investigate the effects of Iguratimod on osteoclast differentiation, migration and function.
  
  
  METHODS
  The effect of Iguratimod on osteoclastogenesis, migration and bone resorption were assessed by TRAP staining, transwell migration assay and osteologic discs, respectively. Relative expressions of osteoclastic related genes, chemokines and transcription factors were assessed by reverse transcription polymerase chain reaction (RT-PCR) and signaling pathways were analyzed by western blotting.
  
  
  RESULTS
  Iguratimod significantly inhibits osteoclast differentiation, migration and bone resorption in RANKL-induced RAW264.7 cell in a dose-dependent manner. The expressions of osteoclastic related genes including TRAP, CTSK and CTR were increased in RAW264.7 cell upon RANKL stimulation but were obviously suppressed in the presence of Iguratimod. RANKL induced the expression of chemokines including CCL7, CCL4 and CCL12 and osteoclastic related transcription factors of c-Fos, c-Jun and NFATc1 could be significantly inhibited by Iguratimod in a dose dependent manner. Western blotting indicated Iguratimod could suppress the activation of MAPKs and NF-κB pathway in RANKL induced osteoclastogenesis in RAW264.7.
  
  
  CONCLUSIONS
  These findings revealed a directly inhibitory role of Iguratimod on osteoclast formation and function, which is distinct from previous report, suggesting Iguratimod provide a unique therapeutic strategy for RA and especially in light of preventing bone destruction.
authors.affiliation: Department of Rheumatology, The First Affiliated Hospital of Nanjing Medical University, 300 Guanzhou Road, Nanjing, China; Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Gan
authors.affiliation: Department of Rheumatology, The First Affiliated Hospital of Nanjing Medical University, 300 Guanzhou Road, Nanjing, China.
authors.forename: Leilei
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Rheumatology, The First Affiliated Hospital of Nanjing Medical University, 300 Guanzhou Road, Nanjing, China.
authors.forename: Lingxiao
authors.initials: L
authors.lastname: Xu
authors.affiliation: Integrative Medicine Institute of Nanjing Medical University, 300 Guanzhou Road, 138 Xianling Road, Nanjing, China.
authors.forename: Xiaoke
authors.initials: X
authors.lastname: Feng
authors.affiliation: Integrative Medicine Institute of Nanjing Medical University, 300 Guanzhou Road, 138 Xianling Road, Nanjing, China.
authors.forename: Qiande
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guanzhou Road, Nanjing, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Rheumatology, The First Affiliated Hospital of Nanjing Medical University, 300 Guanzhou Road, Nanjing, China. Electronic address: tw2006@njmu.edu.cn.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Tan
authors.affiliation: Department of Rheumatology, The First Affiliated Hospital of Nanjing Medical University, 300 Guanzhou Road, Nanjing, China. Electronic address: miaojia_zhang@163.com.
authors.forename: Miaojia
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000818:Animals; D018501:Antirheumatic Agents / Q000494:pharmacology*; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000188:drug therapy*; D001862:Bone Resorption / Q000209:etiology / Q000517:prevention & control*; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002465:Cell Movement / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D050778:NFATC Transcription Factors / Q000235:genetics / Q000378:metabolism; D010010:Osteoclasts / Q000187:drug effects* / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D053245:RANK Ligand / Q000378:metabolism; D000067996:RAW 264.7 Cells; D015398:Signal Transduction / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology*
chemical_list: D018501:Antirheumatic Agents; D002867:Chromones; D016328:NF-kappa B; D050778:NFATC Transcription Factors; C494005:Nfatc1 protein, mouse; D016760:Proto-Oncogene Proteins c-fos; D053245:RANK Ligand; D013449:Sulfonamides; C505689:Tnfsf11 protein, mouse; C519076:iguratimod; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases
keywords: Differentiation; Function; Iguratimod; Migrations; Osteoclast; RANKL