鞘内注射针对Toll样受体4基因的siRNA缓解坐骨神经结扎大鼠的神经病理性疼痛  

Intrathecal injection of siRNA targeting Toll-like receptor 4 reduces neuropathic pain in rat model of chronic constriction injury

作　　者：吴飞翔[1] 缪雪蓉[1] 徐学武[1] 孙玉明[1] 俞卫锋[1] 

机构地区：[1]第二军医大学东方肝胆外科医院麻醉科,上海200438

出　　处：《第二军医大学学报》2011年第4期377-381,共5页Academic Journal of Second Military Medical University

基　　金：国家自然科学基金(30901403)~~

摘　　要：目的观察坐骨神经结扎(CCI)大鼠鞘内注射针对Toll样受体4基因(TLR4)的siRNA(TLR4-siRNA)的镇痛作用及对脊髓TLR4、IL-1β、TNF-α表达的影响。方法大鼠随机分为4组(每组10只):假手术组、CCI组(鞘内注射生理盐水)、错配siRNA组(鞘内注射错配siRNA)及siRNA-TLR4组(鞘内注射TLR4-siRNA)。后3组大鼠均行右侧坐骨神经结扎术,并行L5～L6鞘内置管;假手术组仅暴露坐骨神经而不结扎。TLR4-siRNA组大鼠从CCI术前1 d开始鞘内注射脂质体包裹的有效TLR4-siRNA(10μg/30μl),连续7 d;CCI组、错配siRNA组分别注射等量生理盐水和错配siRNA。采用热辐射及von Frey测痛丝分别测定各组大鼠的热痛阈及机械性痛阈;采用实时定量RT-PCR法观察各组大鼠脊髓组织TLR4 mRNA的表达;采用ELISA法测各组大鼠脊髓组织炎症因子IL-1β、TNF-α的含量。结果与假手术组相比,坐骨神经结扎后,大鼠热痛阈及机械性痛阈降低,脊髓TLR4 mRNA表达量增加,脊髓组织IL-1β、TNF-α的含量也增加(P<0.05)。与生理盐水组及错配siRNA组相比,鞘内注射TLR4-siRNA可抑制坐骨神经结扎引起的热痛觉过敏及机械性异常性疼痛(结扎后1、3、7 d,P<0.05),降低脊髓TLR4 mRNA表达(P<0.05),降低脊髓IL-1β、TNF-α含量(P<0.05)。结论鞘内注射TLR4-siRNA可通过干扰大鼠脊髓TLR4基因表达抑制其信号通路下游炎症因子的水平,进而缓解坐骨神经结扎引起的神经病理性疼痛。Objective To observe the effect of intrathecal injection of siRNA targeting Toll-like receptor 4（TLR4） on neuropathic pain and spinal cord levels of TLR4,IL-1β,and TNF-α in rat model of chronic constriction injury（CCI）.Methods Male Sprague-Dawley rats were randomly divided into four groups（n=10）： the sham group（intrathecal normal saline,IT NS）,CCI group（CCI＋IT NS）,mismatch siRNA group（CCI＋IT mismatch siRNA）, and siRNA-TLR4 group（CCI＋IT siRNA-TLR4）.The lumbar intrathecal catheters were implanted in rats and CCI models were established as previously described.The TLR4 siRNA were administered intrathecally for 7 days starting from 1 day before surgery.The spinal cord expression of TLR4 mRNA was assessed by real-time PCR.Levels of TNF-α and IL-1β in spinal cord were detected by ELISA.The thermal and mechanical nociceptive thresholds were assessed by paw withdrawal latency（PWL） to radiant heat and von Frey filaments.Results Compared with the sham group,animals in CCI group had significantly lower mechanical and thermal pain thresholds,higher expression of TLR4 mRNA and levels of IL1β,TNF-α in the spinal cord（P0.05）.Rats in the siRNA-TLR4 group had significantly higher mechanical and thermal pain thresholds（at 1,3,and 7 days after ligation,P0.05） and significantly lower expression of TLR4 mRNA and levels of IL-1β,TNF-α in the spinal cord compared with those in the CCI group and mismatch siRNA group（P0/05）.Conclusion Intrathecal injection of siRNA-TLR4 can decrease the levels of inflammatory factors by silencing the TLR4 in the spinal cord of rats,and subsequently relieve the neuropathic pain induced by CCI.

关 键 词：TOLL样受体4 神经病理性疼痛 SIRNA 坐骨神经结扎 RNA干扰 白介素1Β 肿瘤坏死因子α 

分 类 号：R441.1[医药卫生—诊断学]