蜘蛛香环烯醚萜类成分对急性脊髓损伤大鼠神经细胞焦亡的影响

Effect of Iridoid-rich Fraction from Valeriana Jatamansi Jones on Neuron Pyroptosis in Rats with Acute Spinal Cord Injury

目的探讨蜘蛛香环烯醚萜类成分对急性脊髓损伤大鼠神经细胞焦亡的影响,及其发挥神经保护作用的相关机制。方法健康雄性Sprague-Dawley大鼠24只,随机分为假手术组、模型组和治疗组,每组8只。后两组建立大鼠急性脊髓损伤模型,假手术组只摘除椎板。术后4 h,治疗组灌胃蜘蛛香环烯醚萜类成分溶液10 mg/kg,模型组和假手术组灌胃等体积羧甲基纤维素钠(CMC-Na)溶液,每天1次,连续7 d。7 d后处死大鼠,HE染色观察脊髓组织病理情况,计算剩余组织残存面积,TUNEL法检测细胞死亡情况,ELISA检测血清中白细胞介素(IL)-1β和IL-18含量,Western blotting测定焦亡蛋白NLRP3、Caspase-1、GSDMD的表达水平。结果与假手术组相比,模型组脊髓组织残存面积减少(P <0.05);TUNEL染色阳性率,IL-1β、IL-18含量以及焦亡蛋白NLRP3、Caspase-1、GSDMD的相对含量增加(P <0.05);与模型组比较,治疗组脊髓组织病理情况有所改善,组织残存面积增加(P <0.05),TUNEL染色阳性率,IL-1β、IL-18含量以及焦亡蛋白NLRP3、Caspase-1、GSDMD的相对含量降低(P <0.05)。结论蜘蛛香环烯醚萜类成分能减轻大鼠脊髓损伤后的炎症反应,发挥神经保护作用,其机制可能与调控NLRP3/Caspase-1通路抑制急性脊髓损伤大鼠的神经细胞焦亡有关。

Objective To investigate the effects of iridoid-rich fraction from Valeriana jatamansi Jones(IRFV)on neuronal pyroptosis in rats with acute spinal cord injury,and to explain the related mechanism of neuroprotection.Methods Twenty-four healthy male Sprague-Dawley rats were randomly divided into sham-operated group,model group and treatment group,with eight rats in each group.The model of spinal cord injury was established by using a medical aneurysm clip in the latter two groups.Only the lamina was removed without injury to the spinal cord in the sham-operated group.Four hours after the operation,the treatment group was given IRFV solution 10 mg/kg,the model group and the sham-operated group were given the same volume of sodium carboxymethyl cellulose(CMC-Na)solution,for seven days.The rats were sacrificed to detected the pathological changes and the residual area of spinal cord tissue through HE staining.The apoptosis of nerve cells of the spinal cord tissue at the perilesional area was detected by TUNEL fluorescent staining.The levels of interleukin(IL)-1 and IL-18 in serum were detected by ELISA Kit and the expression of NLRP3,Caspase-1 and GSDMD were detected by Western blotting.Results Compared with the sham-operated group,the residual area of spinal cord tissue decreased(P<0.05),and the positive rate of TUNEL staining,the level of IL-1 and IL-18,and the expression of pyroptosis-associated proteins(NLRP3,Caspase-1 and GSDMD)increased(P<0.05)in the model group.Compared with the model group,the pathological condition of the spinal cord tissue improved and the residual area of the spinal cord tissue increased(P<0.05);the positive rate of TUNEL staining,the level of IL-1 and IL-18 and the expression of NLRP3,Caspase-1 and GSDMD decreased(P<0.05)in the treatment group.Conclusion IRFV could attenuate the inflammatory response to exert neuroprotective effects,which may be related to the regulation of NLRP3/Caspase-1 signaling pathway to inhibit the neuronal pyroptosis in rats with acute spinal cord injury.