七氟烷预处理上调miR-199a-5p对脊髓缺血/再灌注损伤的保护作用

Sevoflurane preconditioning protects against spinal cord ischemia/reperfusion injury by up-regulating miR-199a-5p in rats

目的研究miR-199a-5p在七氟烷预处理大鼠脊髓缺血/再灌注损伤(SCIRI)中的作用。方法将24只SD大鼠随机分为:假手术组(Sham组)、模型组(I/R组)、七氟烷+模型组(SEVO+I/R组)。Sham组给予同样的手术,但不吸入七氟烷或夹闭主动脉弓;I/R组无创动脉夹夹闭主动脉弓14 min后再灌注,以建立SCIRI模型;SEVO+I/R组,建立SCIRI模型前吸入2.4%的七氟烷3 h。Basso Beattie Bresnahan评分法评价神经运动功能;TUNEL染色观察细胞凋亡情况;伊文思蓝(EB)测定血-脊髓屏障(BSCB)通透性;realtime qPCR检测miR-199a-5p含量;Western blot测定脊髓组织中caspase-9和Bcl-2水平。结果与假手术组比较,I/R组神经运动功能评分降低,细胞凋亡率增加,BSCB通透性增加,miR-199a-5p表达降低,caspase-9表达增加,Bcl-2表达减少;与I/R组比较,SEVO+I/R组神经运动功能评分增加,细胞凋亡率减少,BSCB通透性减少,miR-199a-5p表达增加,caspase-9表达减少,Bcl-2表达增加。结论七氟烷预处理可能通过增加miR-199a-5p,减少BSCB通透性及细胞凋亡,保护大鼠SCIRI。

To investigate the effect of sevoflurane preconditioning on spinal cord ischemia-reperfusion injury(SCIRI)of miR-199a-5p in rats.Methods Twenty-four SD rats were randomly divided into:group of sham(Sham group),group of ischemia-reperfusion(I/R group),and group of sevoflurane and control(SEVO+I/R group).Sham group received the same operation,but did not inhale sevoflurane or close the aortic arch;SCIRI model was established after 14 min of the aortic arch of the non-invasive arterial clip in I/R group.SEVO+I/R group,before the establishment of SCIRI model,was inhaled 2.4%sevoflurane for 3 h.Basso Beattie Bresnahan scoring method was used to evaluate neuromotor function and TUNEL staining to observe apoptosis.Evans blue(EB)was used to determine blood-spinal cord barrier(BSCB)permeability;real-time qPCR to detect miR-199a-5p content;Western blot to measure the levels of caspase-9 and Bcl-2 in spinal cord tissues.Results Compared with sham group,the score of neuromotor function in I/R group decreased,cell apoptosis rate increased,BSCB permeability increased,miR-199a-5p expression decreased,caspase-9 expression increased,and Bcl-2 expression decreased;compared with I/R group,the neurological motor function score of SEVO+I/R group increased,the apoptotic rate decreased,the BSCB permeability decreased,the expression of miR-199a-5p increased,the expression of caspase-9 decreased,and the expression of Bcl-2 increased.Conclusion Sevoflurane pretreatment may reduce BSCB permeability and neuronal apoptosis by up-regulation of miR-199a-5p and protection of SCIRI in rats.