急性脊髓损伤合并内毒素攻击时脊髓内源性锌脂蛋白A20表达  

Expression of endogenous zinc finger protein A20 of spinal tissues after acute spinal cord injury with lipopolysaccharide infection

作　　者：朱凤臣[1] 蒋电明[1] 刘渤[1] 

机构地区：[1]重庆医科大学附属第一医院骨科、重庆市脊注外科中心,400016

出　　处：《中国脊柱脊髓杂志》2008年第12期942-946,I0013,共6页Chinese Journal of Spine and Spinal Cord

基　　金：国家自然科学基金资助项目(30500512)

摘　　要：目的:研究急性脊髓损伤合并内毒素攻击时小鼠脊髓组织中锌脂蛋白A20的表达规律。方法:将健康昆明种小白鼠225只(雌雄不拘,体重l8～24g)随机分为4组:正常对照组(N组,n=9),单纯尾静脉注射生理盐水0.1ml;脊髓损伤组(A组,n=72),按改良Allen′s法制作T10～T11节段脊髓损伤模型;内毒素组(B组,n=72),不进行脊髓损伤只行尾静脉注射内毒素(5mg/kg)0.1ml;脊髓损伤合并内毒素注射组(C组,n=72),制作脊髓损伤模型后再行尾静脉注射内毒素(5mg/kg)0.1ml。A、B、C组分别于处理后0.5、1、2、4、8、12、24、48h,N组于处理后48h,取T10～T11节段脊髓组织。以HE染色观察脊髓损伤程度,以免疫组化(IHC)、逆转录-聚合酶链式反应(RT-PCR)技术分别检测脊髓组织中A20蛋白及mRNA表达。结果:HE染色显示N组和B组各时相点脊髓组织无明显变化;A组打击后0.5h即出现染色质凝聚,染色变深,细胞核偏位、核固缩等现象,神经细胞肿胀,可见片状出血,炎性细胞浸润;至打击8h后可见到核仁消失、核碎裂、核溶解,鬼影细胞现象;C组较A组脊髓损伤更为明显,8h除可见核固缩、碎裂、溶解外,还可见到细胞自溶、空泡形成,并随损伤时间的延长而逐渐加重。IHC显示N组未见A20蛋白阳性表达,A、B组未见或仅有少量A20蛋白阳性表达,C组2h时少量表达,8h表达达高峰。RT-PCR示N组A20 mRNA呈微量表达;A组与N组比较表达升高,与B、C组比较表达高峰延迟,且在12～24h表达高于B、C组;B组在注射内毒素后0.5h,锌脂蛋白A20 mRNA较N组升高明显,1～2h为A20 mRNA表达的高峰期;C组锌脂蛋白A20 mRNA表达最明显,表达高峰在1～8h。结论:在脊髓损伤的早期就出现神经细胞变性死亡的进行性加重,同时伴有锌脂蛋白A20表达增高,合并内毒素注射时尤其明显,锌脂蛋白A20可能对于调控脊髓损伤的炎症反应具有重要意义。Objective ：To investigate the expression protocol of endogenous zinc finger protein A20 in mouse spinal cord tissues under the process of spinal cord injury （SCI） with lipopolysaccharide （LPS） infection. Method：A total of 225 healthy mice（either sex,from Kunming,Yunnan province） with a mean body weight of 21g（range,18-24g） were randomized into 4 groups：animals in control group received Normal Saline of 0.1ml through tail vein （group N,n=9）,the SCI model in T10-T11 was established according to Allen＇s method,animals in group A（n=72） received nothing,animals in group B（n=72） were given LPS through tail vein while spinal cord were kept intact; while animals in group C（n=72） received LPS（5mg/kg） 0.1ml secondary to SCI. Specimens of T10-T11 were taken at 0.5,1,2,4,8,12,24,48h in group A,B and C after surgery respective- ly,and specimens in group N were taken at 48h.The intensity of injury to spinal cord was observed by hematoxylin-eosin （HE） stain.The expression protocol of zinc finger protein A20 protein were measured by immunohistochemistry （IHC） and its mRNA expression were measured by reverse transcription-polymerase chain reaetion（RT-PCR）.Result：There was no obvious change of spinal cord in group B and N at each time point unde HE stain.In group A,karyopycnosis and chromatin condensation emerged at 0.5h after SCI with neurocytes swelling and patchy bleeding and inflammatory cells infiltration,and karyorrhexis,karyolysis and even ＂ghost cell＂ could be seen at 8h after SCI.In group C,the intensity of injury was the more serious than that in group A,with aqtocytolysis and vacuolation seen at 8h in group C which was deteriorating with time processing.There was no expression of positive A20 protein in group N under IHC,while no or little positive A20 protein were present in group A and B.In group C,and little positive A20 protein were evidenced at 2h but reached peak at 8h after SCI.A20 mRNA expressed at a low level in group N under RT-PCR.There was low exp

关 键 词：脊髓损伤 锌脂蛋白A20 内毒素 

分 类 号：R683.2[医药卫生—骨科学] R651.2[医药卫生—外科学]