Soluble complement receptor type 1 inhibits complement system activation and improves motor function in acute spinal cord injury

Study design: Spinal cord injured rat model, treated with soluble complement receptor type 1 (sCR1). Setting: Experimental Animal Department of China Medical University, Shenyang, China. Objectives: Soluble CR1 is a powerful inhibitor of complement activation. In this study, we investigate the effectiveness of sCR1 on spinal cord injury (SCI) in rats. Methods: Spinal cord injury was induced in Sprague-Dawley rats. Three experimental groups were examined; the sCR1 group was administered sCR1 at 1 h after the SCI, whereas the control group was administered saline at 1 h after SCI and the sham group underwent a sham operation without SCI or administration. The expressions of C9 and CD59 in the injured spinal cords were evaluated by immunohistochemistry, and numbers of positive cells counted. Furthermore, myeloperoxidase (MPO) activity and motor function were evaluated in each group. Results: At all postoperative time points, the numbers of C9- and CD59-positive cells in the sCR1 group were reduced compared with the control group and MPO activity was significantly decreased compared with both other groups. Moreover, the Basso, Beattie and Bresnahan score for the sCR1 group was significantly improved as compared with that of the control group after 7 days postoperatively. Conclusion: Soluble CR1 decreases inflammation reactions by inhibiting activation of the complement system and improves motor function after acute SCI. Spinal Cord (2010) 48, 105-111; doi: 10.1038/sc.2009.104; published online 8 September 2009