title: In vitro target validation and in vivo efficacy of p38 MAP kinase inhibition in established chronic collagen-induced arthritis model: a pre-clinical study.
abstract: OBJECTIVE
  The aim of the present study was to determine the in vivo efficacy of p38 mitogen-activated protein kinase (MAPK) inhibitors, namely GW856553X and GSK678361, in murine models of arthritis.
  
  
  METHODS
  The effect of p38 MAPK inhibitors was tested in 2 variants of the collagen-induced arthritis model (CIA) in DBA/1 mice, acute arthritis induced by heterologous collagen and chronic relapsing arthritis induced by homologous collagen. Animals were treated after onset of arthritis. Furthermore, post-onset disease efficacy of GSK678361 was tested in the chronic model, so as to determine the effects on established arthritis. In vitro studies were carried out with GW856553X, using human umbilical vein endothelial cells, to determine potential effects of GW856553X on the vasculature.
  
  
  RESULTS
  In both acute and chronic arthritis, GW856553X reduced signs and symptoms of disease, and protected joints from damage. The effect of GW856553X in chronic CIA was confirmed using an alternative compound, GSK678361. Importantly, treatment with GSK678361 from 14 days post-onset of chronic arthritis completely reversed signs of established disease and joint destruction. Mechanism of action studies demonstrated that GW856553X inhibited endothelial cell migration and angiogenesis in vitro, with reduced pro-inflammatory cytokine production.
  
  
  CONCLUSIONS
  Suppression of murine CIA by the p38 MAPK inhibitors GW856553X and GSK678361 suggests that they may have therapeutic potential for future use in RA if safe clinical dosing achieves adequate compound exposure.
authors.affiliation: Kennedy Institute of Rheumatology and Faculty of Medicine, National Heart and Lung Institute, Imperial College London, UK. k.triantaplyllopoulos@imperial.ac.uk
authors.forename: K
authors.initials: K
authors.lastname: Triantaphyllopoulos
authors.forename: L
authors.initials: L
authors.lastname: Madden
authors.forename: I
authors.initials: I
authors.lastname: Rioja
authors.forename: D
authors.initials: D
authors.lastname: Essex
authors.forename: J
authors.initials: J
authors.lastname: Buckton
authors.forename: R
authors.initials: R
authors.lastname: Malhotra
authors.forename: K
authors.initials: K
authors.lastname: Ray
authors.forename: M
authors.initials: M
authors.lastname: Binks
authors.forename: E M
authors.initials: EM
authors.lastname: Paleolog
mesh_terms: D000208:Acute Disease; D000818:Animals; D001169:Arthritis, Experimental / Q000188:drug therapy* / Q000378:metabolism; D018932:Chemokine CCL2 / Q000378:metabolism; D002908:Chronic Disease; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D042783:Endothelial Cells / Q000166:cytology / Q000201:enzymology; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D051379:Mice; D008811:Mice, Inbred DBA; D009389:Neovascularization, Pathologic / Q000188:drug therapy* / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D012008:Recurrence; D014471:Umbilical Veins / Q000166:cytology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: C111835:CCL2 protein, human; D018932:Chemokine CCL2; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D047428:Protein Kinase Inhibitors; D048051:p38 Mitogen-Activated Protein Kinases