Résumé
Objective To investigate the role of IL-17 in immune inflammatory reaction after spinal cord injury, and provide more evidence for clinical treatment of spinal cord injury on cytokine levels. Methods Male C57BL/6 mice were randomly divided into 4 groups: in the spinal cord injury group, mice were made into spinal cord clamp model. In the sham surgery group, the dura was cut without injuring the spinal cord. The IL-17 neutralizing antibody group received IL-17 neutralizing antibody injection through the cadual vein at 1 h after the spinal cord clamp. The solvent control group received the sterile PBS (0.01 μmol/L) through the cadual vein at 1 h after the spinal cord clamp. Mouse scale for locomotion(BMS) was applied to evaluate the mice's behavior change of hindlimb in 1-7 d. The real time fluorescent quantitative PCR was used to detect the expression changes of IL-1β、IL-6 and TNF-αmRNA, and the immunohistochemistry technique was conducted to observe the morphological changes of neurons of NeuN on the 7th day after spinal cord injury respectivly. Results The behavior score of mice after spinal cord injury indicates: the BMS scores were all 9 on the 1st to the 7th day in the sham surgery group, but were 0 on the 1st day in the model group, the IL-17 neutralizing antibody group and the solvent control group. With time extension, the motor function of hindlimbs of mice in each group were improved, but improved even better in the IL-17 neutralizing antibody group than in the model group and the solvent control group. Immunohistochemistry staining showed that after spinal cord injury, there were much complete structure of NeuN positive staining cells in the gray matter in the sham surgery group, which were obviously shrinking and protrusions disappearing in the model group and the solvent control group, while large number of NeuN neurons vacuolated and reduced significantly. It could be seen that part of neurons morphology was normal and with complete NeuN neuronal cell bodies and branches of the synapse, and the amount of NeuN neuron staining positive cells rebounded in the IL-17 neutralizing antibody group. The results of RT-qPCR on the 7th day after spinal cord injury indicated that compared with sham surgery group, IL-1β mRNA increased significantly in the model group and the solvent control group(P<0.01); compared with the model group and the solvent control group, IL-1β mRMA decreased significantly in the IL-17 neutralizing antibody group(P<0.05); compared with sham surgery group , TNF-α mRNA increased significantly in the model group (P<0.01); compared with the sham surgery group, TNF-α mRNA increased significantly in the solvent control group (P<0.05); compared with the model group , TNF-α mRNA decreased significantly in the IL-17 neutralizing antibody group (P< 0.05). IL-6 mRNA expression was on the decline in the IL-17 neutralizing antibody group, but without statistically significant difference with other groups. Conclusion Combined action of IL-17, IL-1β, IL-6 and TNF-α deteriorates the immune inflammatory of spinal cord injury, and it might relieve spinal cord injury in mice by inhibition of IL-17.
Résumé
The CD4+ T cells have an important effect on the regulation of the adaptive immune response. Unlike Th1 cells and Th2 cells,this newly-found Th17 cell plays an important role in autoimmune diseases,inflammation response,transplant rejection and central nervous system disease by the cytokine IL-17. This paper gives a brief review on the relationship among the Th17 cell,the cytokine IL-17 and the disease of central nervous system.
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Objective To investigate the mechanism of expression of interlenkin (IL)-17 in C57 mice′s spinal cord clamp area,and to provide new targets for clinical treatment of spinal cord injury (SCI). Methods Male C57BL/6 mice were randomly divided into three groups. In the spinal cord injury group,mice were made into spinal cord clamp model. In the sham surgery group, the dura was cut without injuring the spinal cord. The IL-17 neutralizing antibody group received IL-17 neutralizing antibody injection through the cadual vein at 1 hour after the spinal cord clamp . Mouse scale for locomotion (BMS)was applied to evaluate the mice's behavior change of hindlimb in 1-7 days,the real time fluorescent quantitative PCR was used to detect the change in the expression of spinal cord injury district TNF-αmRNA each time,HE staining was conducted to detect the morphological changes of spinal cord injury of the sham surgery group,the spinal cord injury group and the IL-17 neutralizing antibody group at the 7th days. Results After spinal cord injury,the mice's BMS score were 9 in the sham surgery group;in the model of spinal cord injury group,the mice's BMS score were 0 on the 1st day,and 2.9 on the 7th day. In the IL-17 neutralizing antibody group,the mice's BMS score were 0 on the 1st day,and 3.5 on the 7th day. The expression of IL-17 mRNA in the injury area peaked at the 3rd hour,which showed statistical difference when compared with sham surgery group (P0.05),and the expression of IL-17 mRNA reduced the lowest levels on the 7th day. The 7th day following spinal cord injury,mice's spinal cord tissue was complete normal in the sham surgery group. In the spinal cord injury group,a large number of mice's nerve cells were necrotic, a lot of cells formed vacuolated. In the IL-17 neutralizing antibody group, part of mice's nuclear neurons were shrinking, cells formed vacuolated, but part of cells remained morphologically complete. Conclusion IL-17 is involved in secondary immune inflammatory process of spinal cord injury, it may be targets for intervention in the treatment of spinal cord injury.
Résumé
BACKGROUND:Intervention using known inflammatory transmitters has limitations on relieving secondary spinal cord injury. Interleukin-17 is an important proinflammatory cytokine, and is gradual y paid attention in the pathogenesis of central nervous system diseases. OBJECTIVE:To investigate the altered rule of interleukin-17 mRNA and protein in a rat model of acute spinal cord injury. METHODS:Healthy male Sprague-Dawley rats were randomly assigned to two groups. In the model group, rats were made into complete spinal cord transaction models. In the sham surgery group, only spinal dura mater was opened, but parenchyma was not injured. Basso, Beattie, Bresnahan locomotor rating scale was used to observe the effects of acute spinal cord injury on limb motor function of rats. Hematoxylin-eosin staining was used to observe histopathological changes at various time points after spinal cord injury. Real-time fluorescence quantitative PCR and western blotting were used to detect interleukin-17 mRNA and protein levels in each group at various time points after spinal cord injury. RESULTS AND CONCLUSION:Basso, Beattie, Bresnahan locomotor rating scale:Basso, Beattie, Bresnahan scores were 20 to 21 in the sham surgery group. Basso, Beattie, Bresnahan scores were 0 at 1 and 2 days after spinal cord injury. At 7 days, Basso, Beattie, Bresnahan scores were 0 to 3 (P<0.05). Hematoxylin-eosin staining results revealed that compared with the sham surgery group, inflammatory cel infiltration, neuronal and glial cel swel ing, and a reduced number of neuronal processes were observed at 6 hours after spinal cord injury. Gray matter and white matter were loose and vacuolated at 12 hours. Gliocyte proliferation and tissue fibrosis were apparent at 7 days. Real-time PCR results demonstrated that interleukin-17 mRNA appeared at 3 hours, and peaked at 6 hours (P<0.01), and then decreased. Interleukin-17 mRNA levels were similar to the sham surgery group at 7 days. Western blotting results revealed that interleukin-17 expression began to increase at 6 hours and peaked at 12 hours (P<0.05), and then reduced, and reached the levels in the sham surgery group at 7 days. Results indicated that tissue injury was most severe at 12 hours, and showed a time consistency with interleukin-17 expression. It is inferred that interleukin-17 is possibly involved in the process of secondary inflammatory reaction of spinal cord.