title: Beneficial effects of GW274150, a novel, potent and selective inhibitor of iNOS activity, in a rodent model of collagen-induced arthritis.
abstract: The aim of this study was to investigate the role of inducible nitric oxide synthase (iNOS) on the modulation of the inflammatory response in mice subjected to collagen-induced arthritis. Collagen-induced arthritis was induced in wild-type mice (iNOS-WT) treated with GW274150, a novel, potent and selective inhibitor of iNOS activity, and in mice lacking the gene for iNOS (iNOS 'knock-out', iNOS-KO), by an intradermal injection of 100 microl of emulsion containing 100 microg of bovine type II collagen and complete Freund's adjuvant at the base of the tail. After 21 days, a second injection of type II collagen in complete Freund's adjuvant was administered. iNOS-WT mice developed erosive hind paw arthritis when immunised with type II collagen in complete Freund's adjuvant. Over a 35-day period, macroscopic clinical evidence of collagen-induced arthritis first appeared as periarticular erythema and oedema in the hind paws. By day 28, the incidence of collagen-induced arthritis was 100% in type II collagen-challenged iNOS-WT mice and the severity of collagen-induced arthritis progressed with radiographic evaluation revealing resorption of bone. Histopathology of collagen-induced arthritis mice demonstrated erosion of the cartilage at the joint margins. iNOS-WT mice treated with GW274150 (5 mg/kg, i.p. daily) starting at the onset of arthritis (day 23), and iNOS-KO mice showed a delay of the development of the clinical signs at days 24-35 and an improvement of the histological status in the knee and paw. Immunohistochemical analysis for nitrotyrosine and for poly(ADP-ribose) polymerase revealed positive staining in inflamed joints from type II collagen-treated iNOS-WT mice. The degree of staining for nitrotyrosine and poly(ADP-ribose) polymerase were markedly reduced in tissue sections obtained from type II collagen-treated iNOS-WT mice, who had received GW274150 and from iNOS-KO mice. Furthermore, radiographic signs of protection against bone resorption were present in the joints of iNOS-WT mice treated with GW274150 as well as in the joint from iNOS-KO mice. This study provides the first evidence that GW274150, a novel, potent and selective inhibitor of iNOS activity, attenuates the degree of chronic inflammation and tissue damage associated with collagen-induced arthritis in mice. Furthermore, these results suggest that the induction of iNOS and NO production are essential for the up-regulation of the inflammatory response during experimental collagen-induced arthritis.
authors.affiliation: Institute of Pharmacology, School of Medicine, University of Messina, Torre Biologica, Policlinico Universitario Via C Valeria, Gazzi, 98100 Messina, Italy. salvitor@www.unime.it
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cuzzocrea
authors.forename: Prabal K
authors.initials: PK
authors.lastname: Chatterjee
authors.forename: Emanuela
authors.initials: E
authors.lastname: Mazzon
authors.forename: Michelle C
authors.initials: MC
authors.lastname: McDonald
authors.forename: Laura
authors.initials: L
authors.lastname: Dugo
authors.forename: Rosanna
authors.initials: R
authors.lastname: Di Paola
authors.forename: Ivana
authors.initials: I
authors.lastname: Serraino
authors.forename: Domenico
authors.initials: D
authors.lastname: Britti
authors.forename: Achille P
authors.initials: AP
authors.lastname: Caputi
authors.forename: Christoph
authors.initials: C
authors.lastname: Thiemermann
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D003094:Collagen / Q000633:toxicity; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000172:deficiency / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D013440:Sulfides / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D004791:Enzyme Inhibitors; D013440:Sulfides; C409004:GW 274150; D003094:Collagen; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse