鞘内注射干扰素调节因子8小干扰RNA对术后持续性疼痛大鼠痛阈及脊髓小胶质细胞活化的影响  

Effects of intrathecal injection of IRF8 SiRNA on pain threshold and activation of spinal cord microglia in rats with postoperative persistent pain

作　　者：徐昌顺 林春 蔡振宇[1] XU Chang-shun;LIN Chun;CAI Zhen-yu(Department of Pain Management,the First Affiliated Hospital of Xiamen University,Xiamen 361001;Pain Institute,Key Laboratory of Brain Aging and Neurodegenerative Diseases,School of Basic Medical Sciences,Fujian Medical University,Fuzhou 350108,China)

机构地区：[1]厦门大学附属第一医院疼痛科,厦门361001 [2]福建医科大学基础医学院脑老化与神经变性疾病重点实验室福建医科大学疼痛研究所,福州350108

出　　处：《中国应用生理学杂志》2022年第2期113-118,共6页Chinese Journal of Applied Physiology

基　　金：福建省科技创新联合基金(2018Y9069);福建省财政专项基金(2019B028)。

摘　　要：目的:探究鞘内注射干扰素调节因子8小干扰RNA(IRF8 SiRNA)对PPsP大鼠痛阈及脊髓小胶质细胞活化的影响。方法:120只雄性SD大鼠随机分为假手术组(SH,n=12),模型组(SM,n=48),溶媒组(SD,n=12)和IRF8沉默组(SS,n=48),其中,SM组于大鼠后足中部隐静脉内侧按皮肤/肌肉切开牵拉(SMIR)法建立术后持续性疼痛(PPsP)模型,SH组仅切开不牵拉;SD组与SS组建模前一周先于L4/5椎间隙行鞘内置管术,SS组于建模后第5、6日连续鞘内给予IRF8 SiRNA溶液20μl(溶于DEPC水中,150 pmol),SD组给予等量DEPC水。测量并记录建模前(D0),建模后第1(D1)、3(D3)、7(D7)、12(D12)、22(D22)、33(D33)日等时点各组大鼠术侧后足机械刺激缩足反应阈值(PWT);建模后第12日各取6只,Western blot法检测脊髓背角Iba-1蛋白表达情况,并取SH组和SM组各3只,取术野隐神经行电镜观察其超微结构改变;再取SM组和SS组于上述各时点各6只,流式细胞术检测脊髓背角小胶质细胞活化情况。结果:与D0相比,SM组在D1~D22PWT降低(P<0.05或P<0.01),并在D33恢复至正常水平(P>0.05);与SH组相比,SM组PWT在D1~D22均降低(P<0.05或P<0.01);与SD组相比,SS组PWT在D7~D22增高(P<0.05或P<0.01);与SH组相比,SS组D7~D22降低(P<0.05或P<0.01);隐神经髓鞘平均厚度:SH组为(377.03±69.60) nm, SM组为(369.50±73.26) nm,两组间相比无统计学意义(P>0.05);与SH组相比,SM组Iba-1明显上调(P<0.01);与SD组相比,SS组Iba-1表达受到抑制(P<0.05),与SH组相比,SS组Iba-1表达也具有统计学差异(P<0.05),而SM组与SD组之间,Iba-1的表达无统计学意义(P>0.05);与D0相比,SM组小胶质细胞活化比率在D3~D22均显著增加(P<0.01),而SS组小胶质细胞活化于D3达到高峰(P<0.01);鞘内给药后,SS组脊髓背角小胶质细胞活化比率明显下降,与SM组相比,在D7~D12显著下降(P<0.01)。结论:SMIR诱导的PPsP大鼠显著且持续的机械痛觉过敏为非明显的外周神经损伤所致,可能是基于脊髓背角小胶质细胞�Objective:To investigate the effects of intrathecal injection of IRF8 SiRNA on the pain threshold and activation of spinal cord microglia in rats with postoperative persistent pain.Methods:One hundred and twenty male Sprague-Dawley rats were randomly divided into sham group(SH,n=12),SMIR group(SM,n=48),SMIR+DEPC group(SD,n=12)and SMIR+irf8 SiRNA group(SS,n=48).In the SM group,the persistent postsurgical pain(PPsP)model was established according to the skin/muscle incision and retraction(SMIR),and the SH group was only incised without retracted.The SD group and SS group received intrathecal catheterization one week before SMIR,the SS group was injected with 20μl of IRF8 SiRNA solution(dissolved in DEPC-treated water,150 pmol)intrathecally on the 5^(th) and 6^(th) day after SMIR,and the SD group was injected with the same amount of DEPC-treated water.The paw withdrawal threshold(PWT)of each group was measured and recorded before SMIR and on the 1^(st),3^(rd),7^(th),12^(th),22^(nd) and 33^(rd) days after SMIR.Western blot was used to detect the expression of Iba-1 in the dorsal horn of spinal cord on the 12^(th) days after SMIR,and the saphenous nerves in the SH group and SM group were collected to observe their ultrastructural changes under electron microscope.The flow cytometry was used to detect the activation of microglia in spinal cord dorsal horn before SMIR and on the 1^(st),3^(rd),7^(th),12^(th),22^(nd) and 33^(rd) days after SMIR in the SM group and SS group.Results:Compared with D0,the PWT of SM group was decreased on the 1^(th) to 22^(nd) day after SMIR(P<0.05 or P<0.01),and returned to normal level on the 33^(rd) day after SMIR(P>0.05).Compared with the SH group,the PWT of the SM group was decreased on the 1^(th) to 22^(nd) day after SMIR(P<0.05 or P<0.01).However,compared with the SD group,the PWT of the SS group was increased on the 7^(th) to 22^(nd) day after SMIR(P<0.05 or P<0.01).Compared with SH group,the PWT of SS group was decreased on the 7^(th) to 22^(nd) day after SMIR(P<0.05 or P<0.01).The a

关 键 词：干扰素调节因子8 小胶质细胞 术后持续性疼痛 脊髓 痛觉过敏 大鼠小干扰RNA(SiRNA) 

分 类 号：R363[医药卫生—病理学] R602[医药卫生—基础医学]