title: Inhalation of carbon monoxide ameliorates collagen-induced arthritis in mice and regulates the articular expression of IL-1beta and MCP-1.
abstract: Carbon monoxide (CO), long considered a toxic gas, has recently been shown to mediate anti-inflammatory effects in various animal models. The aim of this study was to investigate whether the inhalation of CO ameliorated collagen-induced arthritis (CIA) in mice. CIA was induced in female DBA/1 mice by the injection of an anti-type II collagen antibody and lipopolysaccharide. The CO treatment group was exposed to CO gas at a concentration of 200 ppm in a closed cage starting on the day of the injection with an anti-type II collagen antibody and throughout the remaining study period. The clinical arthritis scores was examined daily for swelling of the paws as a sign of arthritis. For histopathology, the sections of the hind legs were evaluated by hematoxylin-eosin staining. Moreover, we evaluated the expression of interleukin (IL)-1beta and monocyte chemoattractant protein-1 (MCP-1) mRNA in the hind paws. Both clinical arthritis scores as well as histological findings of joint inflammation were significantly reduced in mice treated with CO gas inhalation compared to untreated mice. Further, CO significantly inhibited the increased expression of IL-1beta and MCP-1 mRNA in paws at day 3 after the induction of arthritis. In conclusion, the inhalation of CO protected mice from the synovial inflammation of CIA. Based on these data, the beneficial effects of CO in murine RA model may be attributed to its anti-inflammatory properties.
authors.affiliation: Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Sience, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Takagi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Naito
authors.forename: Mamoru
authors.initials: M
authors.lastname: Inoue
authors.forename: Satomi
authors.initials: S
authors.lastname: Akagiri
authors.forename: Katsura
authors.initials: K
authors.lastname: Mizushima
authors.forename: Osamu
authors.initials: O
authors.lastname: Handa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kokura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yoshikawa
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000628:therapy*; D002248:Carbon Monoxide / Q000008:administration & dosage* / Q000627:therapeutic use; D002358:Cartilage, Articular / Q000378:metabolism*; D018932:Chemokine CCL2 / Q000235:genetics*; D003094:Collagen / Q000009:adverse effects; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D007249:Inflammation / Q000517:prevention & control; D053583:Interleukin-1beta / Q000235:genetics*; D051379:Mice; D008815:Mice, Inbred Strains; D012333:RNA, Messenger / Q000032:analysis; D012720:Severity of Illness Index
chemical_list: D018932:Chemokine CCL2; D053583:Interleukin-1beta; D012333:RNA, Messenger; D002248:Carbon Monoxide; D003094:Collagen