To assess the protective effects of the
cytokine inhibitor
interleukin-1 receptor antagonist (IL-1ra) on gene induction, an electroporation technique to treat adjuvant-induced
arthritis (AIA) in rats was established, and its advantage was estimated in the present study. Electroporation with human
IL-1ra was performed in Lewis rats before and after induction of AIA. Local
inflammation was evaluated by monitoring hind paw swelling, whereas histological evaluations were performed using
paraffin embedded sections of hind paw specimens stained with
hematoxylin and
eosin. In addition, serum IL-1? levels were analyzed using an
enzyme-linked
immunosorbent assay. Induction of
IL-1ra by our electroporation method inhibited systematic
body weight loss and enhancement of local
inflammation after
intradermal injection of heat-killed Mycobacterium tuberculosis. Notably,
IL-1ra electroporation reduced paw swelling,
inflammation, and bone erosion scores in embedded sections and serum IL-1? levels induced in AIA rats. The
IL-1ra gene induction using the present electroporation technique inhibited local and systematic
inflammation in AIA rats. These results indicate that this method may represent a novel
pharmacotherapy strategy for
arthritis.