RNA干扰技术抑制nNOS基因对根性撕脱伤脊髓运动神经元的影响  

Effect of RNAi mediated inhibition of nNOS expression on motoneuron death induced by avulsion

作　　者：廖晓燕[1] 付饶[2] 王家传[2] 刘述[2] 周丽华[2] 

机构地区：[1]广东省梅州市人民医院眼科,广东梅州514000 [2]中山大学中山医学院人体解剖学教研室,广东广州510080

出　　处：《解剖学研究》2011年第4期265-270,共6页Anatomy Research

摘　　要：目的研究神经元型一氧化氮合酶(neuronal nitric oxide synthase,nNOS)基因在臂丛神经根撕脱伤中的作用地位。方法设计、筛选并构建针对nNOS基因的siRNA表达载体,建立C5～T1神经根撕脱伤SD雄性大鼠模型,于撕脱后14d脊髓鞘内给予nNOS的siRNA干预,3d后用NADPH-d酶组化反应结合中性红染色评估撕脱伤脊髓运动神经元的nNOS基因表达水平和创伤神经元的存活率。结果臂丛C5～T1根性撕脱伤17d后,C7节段损伤侧前角运动神经元的存活率在siRNA组、siRNA序列对照组和生理盐水组分别为(80.51±9.16)%、(88.26±2.95)%和(89.13±3.47)%;C7节段损伤侧前角运动神经元的nNOS阳性率为(18.10±6.63)%、(42.21±2.29)%和(39.46±2.41)%。nNOS的siRNA能显著减低撕脱伤诱导的nNOS蛋白在前角运动神经元内的表达水平。虽然与对照组相比,nNOS-siRNA组撕脱伤后运动神经元存活率有下降趋势,nNOS的siRNA但并未对撕脱伤导致的运功神经元的死亡造成显著影响。结论鞘内应用siRNA技术能下调撕脱伤后大鼠脊髓运动神经元内nNOS蛋白的表达,nNOS基因有可能发挥维持撕脱伤后运动神经元存活的作用。Objective To investigate the effects of nNOS gene on the nNOS expression and survival situation of spinal motoneuron（MN） following avulsion.Methods Roots avulsion models were completed on the SD rats,then the siRNA gene consequence targeting on nNOS was constructed,then applicatied into spinal cord intrathecally on the 14d after avulsion.All animals were subdivided randomly into 3 groups including saline control group,random sequence siRNA control group and nNOS-siRNA treatment group.MN nNOS expression and survival rate were evaluated with the methods of NADPH-d histochemical staining and neutral red counterstaining at 17 d followed avulsion surgery.Results The nNOS-positive MNs rate in saline control group,random sequence siRNA control group and nNOS-siRNA treatment group were（39.46±2.41）%,（42.21±2.29）% and（18.10±6.63）% respectively,compared to two control groups,the nNOS-positive MNs rate in siRNA treatment group decreased significantly（P0.05）.The MN survival rate in 3 groups were（89.13±3.47）%,（88.26±2.95）% and（80.51±9.16）%.Compared to control groups,although there was a decline trend about MN survival rate in nNOS-siRNA treatment group but without statistical significance（P0.05）.Conclusion The present study provide a strong proof that siRNA can be applied in the avulsion model effectively and safely,furthermore siRNA could blockade the expression of nNOS in MN and induced the decreasing on MN survival rate followed by root avulsion.In a word,our present data indicated that nNOS gene may play a positive role in sustaining for MN survival after avulsion injury.

关 键 词：SIRNA 一氧化氮合酶 脊髓运动神经元 臂丛根性撕脱 

分 类 号：R651.2[医药卫生—外科学]