Molecular mechanism of activation of Wnt/β-catenin signaling pathway by liraglutide to protect nerve function after acute spinal cord injury in rats
Objective To explore the mechanism of the neuroprotective effects of liraglutide on acute spinal cord injury rats by regulating the Wnt/β-catenin signaling pathway.Methods Of the 60 SD rats,15 were randomly selected as sham operation group(only underwent T9～T10 laminectomy),and the remaining 45 rats were used to establish the acute spinal cord injury model using the modified Allens technique.After the successful establishment of spinal cord injury model,the rats were randomly divided into model group,liraglutide group and liraglutide+XAV939 group,with 15 rats in each group.During the first 14 days af-ter spinal cord injury,the rats in the sham operation group and model group were subcutaneously injected with 50 mg/kg of saline daily,while the rats in the liraglutide group were subcutaneously injected with 50 μg/kg of liraglutide daily.The rats in the liraglutide+XAV939 group were subcutaneously injected with 50 μg/kg of liraglutide and 0.4 mg/kg of XAV939(a small molecule inhibitor of the Wnt/β-catenin signaling pathway)daily.Lower limb motor function of rats were assessed by BBB scoreing method before surgery,intervention 7th day and 14th day.On the 14th day,the protein expression levels of β-catenin,caspase-3,tumor necrosis factor α(TNF-α)and interleukin 6(IL-6)were analyzed by Western blot and immunohistochemistry.On the 14th day,the neural cell changes in rat spinal cord tissue were observed by HE and Nissl staining.Results There was no difference in BBB scores between the groups before opera-tion.After intervention 7 d and 14 d,BBB scores in the model group,liraglutide and liraglutide+XAV939 group were significantly lower than the sham group(P＜0.05),and the BBB score was significantly high-er in liraglutide group than model group and liraglutide+XAV939 group(P＜0.05),while the difference in the model group and liraglutide+XAV939 group was not statistically significant(P＞0.05).The num-ber of positive cells in the spinal cord in the model group,liraglutide group and liraglutide+XAV939 group was significantly lower than that in the sham group(P＜0.05).Compared with model group and li-raglutide+XAV9 3 9 group,the number of Nissl positive cells in liraglutide group was significantly in-creased(P＜0.05).There was no significant difference in the number of positive cells between the model group and liraglutide+XAV939 group(P＞0.05).The Western blot analysis showed that β-catenin was significantly higher in the model group compared to sham group(P＜0.05).Compared with model group,the β-catenin in the liraglutide group was significantly increased(P＜0.05).Compared with liraglutide group,β-catenin in liraglutide+XAV939 group was significantly decreased(P＜0.05).The expression levels of caspase-3,IL-6 and TNF-α were significantly higher in the model group compared to the sham group(P＜0.05),liraglutide decreased the expression of caspase-3,IL-6 and TNF-α compared to the model group(P＜0.05).Compared with the liraglutide group,the expression of caspase-3,IL-6 and TNF-α was significantly higher in the liraglutide+XAV939 group(P＜0.05).The results of immunohis-tochemical staining were similar to those of western blot analysis.Conclusion Liraglutide may regulate the expression levels of related proteins by activating the Wnt/β-catenin signaling pathway and inhibit neu-ral cell apoptosis to exert neuroprotective effects in rats with acute spinal cord injury.
万方数据
维普
