The Effect Of Erythropoietin On The Expression Of Nf-κB And Inflammatory Cytokines After Acute Spinal Cord Injury In Rats

Part IExpression of nuclear factor-κB and inflammatory cytokines after acute spinal cord injury in ratsObjectiveTo observe the expression level of nuclear factor-κB(NF-κB) and inflammatory factor of tumor necrosis factor (TNF-α), interleukin(IL)-1βand IL-6 after acute spinal cord injury in rats, and to explore its possible relationship with acute spinal cord injury,also observed for the next step of erythropoietin (EPO) treatment of spinal cord injury in a reasonable time window.Methods30 SD rats weighting(250+10)g were randomly divided into 5 groups(control group, 6h group, 24h group, 72h group, 7d group), SD rat model of acute spinal cord injury were established by aneurysm clip with 30g power cord clamping from both sides of spinal cord for 30s. Rats after operation were sacrificed respectively after 6h, 24h, 72h and 7d. The expression of NF-κB was detected by EMSA assay and the expression of TNF-α, IL-1βand IL-6 were examined with ELISA in spinal cord tissue.ResultThe activity of NF-κB and the expression of TNF-α, IL-1βand IL-6 were significantly higher than control group 6 hours after spinal cord injury(P<0.01). The highest NF-κB activity in 72h after operation, TNF-α, IL-1βexpression peaked at 24h and IL-6 expression peaked at 72h after operation. Factor expression in each group after 7 days had fallen, but still higher than the level of control group(P<0.01).ConclusionThe high expression of TNF-α, IL-1βand IL-6 may lead to inflammation and increase the important factors in spinal cord injury, regulation of the expression of NF-κB activity can provide a new clinical treatment strategy for spinal cord injury. NF-κB activity and expression of inflammatory cytokines in each group wre in the peak period between 24h to 72h, this provided a time window to observe the EPO treatment of spinal cord injury.Part IIThe effect of erythropoietin on the expression of NF-κB and inflammatory cytokines after acute spinal cord injury in ratsObjectiveTo observe the influence of erythropoietin (EPO) administration on expression of nuclear factor-kappa B(NF-κB) and inflammatory cytokines of tumor necrosis factor-α(TNF-α), interleukin(IL)-1β, IL-6 following acute spinal cord injury and to explore the possible mechanisms of reducing secondary spinal cord injury.Methods18 SD rats weighting(250+10)g were randomly divided into 3 groups: Control group, injury group and treatment group. Treatment group were given intraperitoneal injection of EPO(5000u/kg) at 1h, on the 1st, 2nd and 3rd day after establishment of spinal cord injury model. All rats were sacrificed after 3days. The expression of NF-κB was detected by EMSA assay and the expression of TNF-α, IL-1βand IL-6 were examined with ELISA, the spinal cord edema was evaluated by spinal cord water content, and the hindlimb function in rats was evaluated by the BBB Rating.ResultThe levels of NF-κB, TNF-α, IL-1β, IL-6 in spinal cord tissue of treatment group were significantly lower than those in injury model group(P<0.05), and the levels of spinal cord edema and indlimb function were no statistically significant.ConclusionEPO administration can down-regulate the expression of the inflammatory cytokines, inhibit the inflammatory response and play a role in protecting the secondary spinal cord injury, but the Functional recovery of spinal cord was no significant change.