联合激活mTOR和STAT信号通路对脊髓损伤小鼠轴突再生及运动功能的影响  

Effect of combined activation of mTOR and STAT signaling pathways on axon regeneration and motor function in mice with spinal cord injury

作　　者：易凌荣 谭波涛[1] 刘媛 殷樱[1] 虞乐华[1] Yi Ling-Rong;Tan Bo-Tao;Liu Yuan;Yin Ying;Yu Le-Hua(Department of Rehabilitation Medicine,the Second Affiliated Hospital of Chongqing Medical University,Chongqing 400010,China;Research Institute of Surgery,Daping Hospital,Army Medical University Chongqing 400042,China)

机构地区：[1]重庆医科大学附属第二医院康复医学科,重庆400010 [2]陆军军医大学大坪医院野战外科研究部,重庆400042

出　　处：《解放军医学杂志》2022年第1期12-19,共8页Medical Journal of Chinese People's Liberation Army

基　　金：国家自然科学基金(81702221,81772066);重庆市自然科学基金(cstc2018jcyjAX0180);重庆市渝中区基础研究与前沿探索项目(20180121)。

摘　　要：目的探索联合激活AKT/mTOR和JAK/STAT信号通路对小鼠C;脊髓钳夹损伤后皮质脊髓束轴突再生和运动功能的影响。方法成年C;7/BL小鼠40只,随机分为磷酸酶和张力蛋白同源物(PTEN)/细胞因子信号抑制物3(SOCS3)组(注射PTEN抑制病毒和SOCS3抑制病毒)、PTEN组(注射PTEN抑制病毒)、SOCS3组(注射SOCS3抑制病毒)与对照组(注射空载对照病毒),每组10只,所有小鼠均于感觉运动皮质区进行病毒注射。采用免疫荧光染色检测锥体神经元p-S6和p-STAT3的表达以明确通路激活情况。注射病毒2周后,对各组小鼠进行C;钳夹损伤,使用生物素化葡聚糖胺(BDA)顺行示踪皮质脊髓束。在损伤前及损伤后1、2、4、6周行水平楼梯和圆筒攀爬探索实验检测小鼠运动功能恢复情况。结果免疫荧光染色结果显示,腺相关病毒(AAV)成功转染感觉运动皮质锥体神经元。PTEN/SOCS3组和PTEN组皮质神经元p-S6表达明显增加,其荧光强度[分别为(25.429±2.991) AU、(26.171±2.140) AU]明显高于SOCS3组和对照组[分别为(9.544±2.474) AU、(9.558±1.650) AU],差异有统计学意义(P<0.001);PTEN/SOCS3组和SOCS3组p-STAT3表达增加,其荧光强度[分别为(48.900±6.310) AU、(46.721±5.169) AU]明显高于PTEN组和对照组[分别为(12.952±1.282) AU、(14.394±1.983) AU],差异有统计学意义(P<0.001)。与对照组相比,3个抑制干预组皮质脊髓束损伤后出现明确的轴突再生反应,其中PTEN/SOCS3组再生距离最远,再生数量最多,差异有统计学意义(P<0.05)。各组动物水平楼梯和圆筒攀爬探索实验运动表现在各个时间点差异均无统计学意义(P>0.05)。结论联合激活AKT/mTOR和JAK/STAT信号通路可提高神经元轴突内源性再生能力,促进脊髓损伤小鼠轴突再生,但对其早期运动功能恢复的作用不明显。Objective To investigate the effect of AKT/mTOR and JAK/STAT pathways co-activation on axon regeneration and function recovery in C;spinal cord injury mice. Methods Forty adult C;7/BL mice were randomly divided into PTEN/SOCS3 group(injected PTEN virus and SOCS3 virus), PTEN group(injected PTEN virus), SOCS3 group(injected SOCS3 virus) and control group(injected empty control virus), 10 mice in each group. Adeno-associated-virus(AAV) were injected into the sensorimotor cortex. The activation of AKT/mTOR and JAK/STAT pathways in pyramidal neurons was detected by measuring the expression of p-S6 and p-STAT3 using immunofluorescence staining. Two weeks after injection, all the mice received C;crush injury. Biotinylated dextran amine(BDA) tracer was used to label corticospinal tract. The horizontal ladder and cylinder rearing tests were used to assess motor function recovery at pre-injury, and one week, two weeks, four weeks and six weeks after injury.Results Immunofluorescence staining results showed that AAV successfully infected the sensorimotor cortex pyramidal neurons.The expression of p-S6 in PTEN/SOCS3 group and PTEN group were significantly increased, the fluorescence intensity of p-S6[(25.429±2.991) AU and(26.171±2.140) AU] were significantly higher than SOCS3 group and control group [(9.544±2.474) AU and(9.558±1.650) AU](P<0.001). The expression of p-STAT3 in PTEN/SOCS3 group and SOCS3 group were obviously increased, compared with PTEN group and control group [(12.952±1.282) AU and(14.394±1.983) AU], the fluorescence intensity of p-STAT3 in PTEN/SOCS3 group and SOCS3 group [(48.900±6.310) AU and(46.721±5.169) AU] were significantly higher(P<0.001). Compared with control group, the other three groups showed obvious axon regeneration after corticospinal tract injury. The regeneration distance and number were longer and more in PTEN/SOCS3 group(P<0.05). There was no significant difference between four groups in horizontal ladder and cylinder rearing tests at various time points(P>0.05). Conclusion Coac

关 键 词：脊髓损伤 哺乳动物雷帕霉素靶蛋白 STAT 轴突再生 运动功能 

分 类 号：R493[医药卫生—康复医学]