Effect Of Methylprednisolone On Expression Of The Inflammatory Cytokines And Autophagy Factor In Injured Spinal Cord Segment

ObjectiveTo investigate the effect of methylprednisolone (MP) on the expressions ofinflammatory cytokines IL-6、IL-10and autophagy factor LC3B in injured spinalcord segment after spinal cord injury. Discuss the preliminary relations betweenthe inflammatory cytokines IL-6、IL-10and autophagy factor LC3B, so as toprovide a new treatment mind for spinal cord injury.Method60female SD rats（220g～250g）were divided into three groups: Shamoperation group (n=20), Operation group (n=20) and MP group (n=20). Themodel of SCI was established by using the modified Allen’s method at T10ofspinal cord. MP was given by tail intravenous injection (30mg/kg) after SCI inMP group and the SD rats in Operation group without any treatment after SCI.Rats in Sham operation group only were opened laminectomy without damagingthe spinal cord. The spinal cord tissues were removed at4h、12h、1d、3d and7d after operation. The changes of the expressions of the inflammatorycytokines IL-6、IL-10and autophagy factor LC3B in the corresponding damagedsegment of spinal cord were detected by using semi quantitative RT-PCRmethod.Results1．Successfully established the Allen ’s model of spinal cord injury in rats. 2．The expressions of IL-6、IL-10and LC3B mRNA was lower in injuredspinal cord segment in the Sham group, whereas the expressions of thosemRNA were increased significantly in the corresponding spinal cord segment inthe Operation group at4h after operation, and reached the peak at1st day afteroperation, then gradually reduced（P﹤0.05）. The trends of the expressions ofLC3B、IL-6and IL-10were similar in Operation group. The expression of LC3Bwas respectively positive correlated with the expressions of IL-6and IL-10inOperation group. The expression of IL-6、IL-10and LC3B in injured spinal cordsegment in MP group were inhibited from12h after operation, reaching theminimum at1st day after operation. The expressions of LC3B were lower thanthose in Operation group at7th day after operation（P﹤0.05）. The trends of theexpressions of IL-6、IL-10and LC3B were similar in MP group. The expressionof LC3B was also respectively positive correlated with IL-6、IL-10in MP group.ConclusionAccording to the experimental results, Methylprednisolone inhibits theexpressions of autophagy factor LC3B and inflammation factor IL-6and IL-10in the damaged segment of spinal cord. This suggests that Methylprednisolonemay inhibit the autophagy through inhibiting the inflammatory response in thecorresponding damaged segment of spinal cord.