Expression And Significance Of SUMO-1 In Adjuvant-induced Arthritis Mouse And Influence Of ～(99)Tc-MDP

Objective To examine the expression of small ubiquitin-like modifier-1(SUMO-1)in adjuvant-induced arthritis (AA) mouse and the influence of ⁹⁹Tc-MDP.Methods The AA was established by subcutaneous injection with complete Freud's adjuvant to rats, except the normal group A(n=8). The rats successfully induced AA(n=18) were divided into two groups randomly:â‘ Model group B(n=8, treated with normal saline);â‘¡⁹⁹Tc-MDP group C(n=10, treated with ⁹⁹Tc -MDP); The symptoms of arthritis were evaluated by arthritis index; the histopathological (hematoxylin and eosin stain) changes of joint were scored in infiltration of inflammatory cells and hyperplasia of synoviocytes. The expressions of SUMO-1 in synovium and joint were detected by Immunohistochemistry technique.Results 1. Arthritis index(AI): The arthritis indexes of model group and ⁹⁹Tc-MDP group were increasing with the time elongation. There were no significant diferences in the first 36 days, after which the arthritis indexes of model group became higher than ⁹⁹Tc-MDP group (P<0.05). 2. The histopathological score: The histopathological scores of model group were significantly higher than ⁹⁹Tc-MDP group(P<0.05). 3. Immunohistochemistry Assay: The levels of SUMO-1 of model group and ⁹⁹Tc-MDP group were notably higher than those of normal group (P<0.05). The levels of SUMO- 1 of model group were notably higher than those of ⁹⁹Tc -MDP group(P<0.05). 4 The correlation between SUMO-1 and the level of hyperplasia of synoviocytes and AI were very good.Conclusion The expression of SUMO-1 in AA mouse with severe arthritis is significantly increased, and it is correlated with disease active index and level of hyperplasia of synoviocytes. SUMO-1 may be one of important factor in the pathogenesis of rheumatoid arthritis (RA). ⁹⁹Tc -MDP can comparatively decrese the levels of SUMO-1, and it may induce apoptosis of synoviocytes.