Method: CIA was induced in DBA/1J mice by the immunization with bovine type II collagen twice on day 0 and 21. On day 35, hind paws and serum were collected at 0, 1, 3, and 6 hours after a single oral administration of 30 mg/kg of T-5224. The tissue extracts were prepared from each paw. The amounts of 23 cytokines/chemokines in the tissue extracts and sera were measured using Bio-Plex Mouse Cytokine 23-Plex Panel or ELISA.
Result: The arthritis developed from several days after the secondary immunization, and mice showed severe arthritis on day 35. When analyzing each of hind paws with full-blown arthritis, the levels of 9 cytokines/chemokines [IL-1β, IL-3, IL-6, IL-12 (p40), G-CSF, KC/groα, MCP-1, MIP-1β, and RANTES] significantly increased compared with those in the normal paws. Especially, the amounts of IL-1β, IL-6, and KC/groα in the arthritis hind paws were approximately 40 times higher than those in normal paws. A single administration of T-5224 at the dose of 30 mg/kg significantly decreased the levels of IL-1β, IL-6, and KC/groα within several hours. Eight cytokines/chemokines including TNFα could not be determined in the paws. The significant elevations of the levels of IL-1β, IL-3, IL-6, G-CSF, KC/groα, MCP-1, and MIP-1β were also observed in the sera from the same individuals. The serum levels of IL-1β and KC/groα were significantly decreased by the treatment of T-5224.
Conclusion: T-5224 immediately reduced the levels of inflammatory cytokines and chemokines in the arthritic lesion. The results suggest that the prompt inhibitory effect of T-5224 on the overexpression of cytokines and chemokines contributes to the anti-arthritic effects in the therapy of RA.
Disclosure: Y. Aikawa, Toyama Chemical Co.,LTD, 3 ; A. Hashiramoto, None; T. Yamamoto, Toyama Chemical Co.,LTD, 3 ; M. Mikami, Toyama Chemical Co.,LTD, 3 ; H. Narita, Toyama Chemical Co.,LTD, 3 ; S. Hirono, None; S. Shiozawa, None.