七氟烷对大鼠脊髓缺血再灌注损伤及Wnt/β-catenin信号通路的影响

Effects of sevoflurane on spinal cord ischemia-reperfusion injury and Wnt/β-catenin signaling pathway in rats

目的:探究七氟烷(sevoflurane,SEVO)在大鼠脊髓缺血再灌注(spinal cord ischemia-reperfusion,SCIR)中的作用及对其对Wnt/β-catenin信号通路的影响。方法:实验大鼠分为SCIR组、SEVO组、SEVO+XAV939(XAV;β-catenin抑制剂)组和假手术组,每组10只。HE、Nissl和TUNEL染色观察脊髓组织损伤;免疫组化和免疫荧光法观察脊髓轴突再生情况;Western blot检测β-catenin、生长相关蛋白43(growth associated protein 43,GAP43)、神经丝H(neurofilament-H,NF-H)、微管相关蛋白2(microtubule-associated protein 2,MAP2)、硫酸软骨素蛋白聚糖NG2(chondroitin sulfate proteoglycan NG2,NG2)及髓磷脂碱性蛋白(myelin basic protein,MBP)水平。结果:SCIR组脊髓组织有空洞,可见肿胀或核固缩的坏死或凋亡细胞,尼氏小体较少,SEVO可减轻上述损伤。SCIR组GAP43和NG2蛋白水平显著高于假手术组(P<0.01),吸入SEVO则进一步增加GAP43和NG2蛋白水平。SCIR组BBB评分,NF-H+、MBP+、β-catenin+GAP43+和β-catenin+MBP+细胞数量,NF-H、MAP2、MBP蛋白水平和胞质、核及总蛋白中β-catenin水平、核/胞质β-catenin比例显著低于假手术组(P<0.05);吸入SEVO后上述指标均被逆转,但XAV则可明显减弱SEVO的上述作用。结论:SEVO可促进轴突和髓鞘再生,减轻SCIR大鼠神经损伤,其机制可能与激活Wnt/β-catenin通路有关。

AIM:To investigate the protective effect of sevoflurane(SEVO)on spinal cord ischemia-reperfusion(SCIR)rats and its effect on Wnt/β-catenin pathway.METHODS:The mice were divided into SCIR group,SEVO group,SEVO+XAV939(XAV;β-catenin inhibitor)group and sham group,with 10 mice in each group,and were given corresponding treatments. HE,Nissl,and TUNEL staining were performed to observe spinal cord injury. Immunohistochemistry and immunofluorescence were performed to observe the regeneration of spinal cord axons. Western blot was performed to detect the levels of β-catenin,growth-associated protein 43(GAP43),neurofilament-H(NF-H),microtubuleassociated protein 2(MAP2),chondroitin sulfate proteoglycan NG2(NG2),and myelin basic protein(MBP).RESULTS:In SCIR group,there were cavities in the spinal cord,necrotic or apoptotic cells with swelling or pyknosis,and fewer Nissl bodies. Inhalation of SEVO was able to alleviate the above injuries. GAP43 and NG2 protein levels in SCIR group were significantly higher than those in sham group(P<0. 01). Inhalation of SEVO further increased GAP43 and NG2 protein levels. The BBB score,the NF-H+,MBP+,β-catenin+GAP43+and β-catenin+MBP+cell numbers,the NFH,MAP2 and MBP protein levels,the cytoplasm,nuclear and total β-catenin levels,and the nuclear/cytoplasmic β-catenin ratio in SCIR group were significantly lower than those in sham group(P<0. 05). Inhaled SEVO inhibited the reduction of these indicators,and XAV reversed the neuroprotective effect of SEVO.CONCLUSION:SEVO can promote the regeneration of axons and myelin sheaths,and alleviate the nerve injury in SCIR rats. Its mechanism may be related to the activation of Wnt/β-catenin signaling pathway.