上海交通大学学报（医学版）

上海交通大学学报（医学版）

• 论著（基础研究） • 上一篇    下一篇

大鼠脊髓损伤早期PI3K/Akt/mTOR信号转导通路的活性改变及其与后肢运动功能恢复的关系

刘杨，苗宇船   

  1. 山西中医学院病理学教研室， 太原 030619
  • 出版日期:2015-06-28 发布日期:2015-07-30
  • 通讯作者: 苗宇船, 电子信箱: mych65@163.com。
  • 作者简介:刘杨（1980—）， 男， 副教授， 博士生; 电子信箱: syfy2004@163.com。
  • 基金资助:

    山西中医学院博士科研启动基金

Changes of activity of PI3K/Akt/mTOR signaling pathway in early stage of spinal cord injury of rats and its relationship with recovery of motor function of posterior limbs

LIU Yang, MIAO Yu-chuan   

  1. Department of Pathology, Shanxi University of Traditional Chinese Medicine, Taiyuan 030619, China
  • Online:2015-06-28 Published:2015-07-30
  • Supported by:

    Scientific Research Fund for Doctoral Young Scholars, Shanxi University of Traditional Chinese Medicine

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摘要：

目的 探讨大鼠脊髓损伤（SCI）早期PI3K/Akt/mTOR信号转导通路活性改变及其对后肢运动功能恢复的影响。方法 SD大鼠随机分为正常组、对照组和4个实验组（伤后1、3、5、7 d组），其中对照组和实验组大鼠采用Allen's法建立SCI模型。对照组大鼠给予鞘内注射20 μL LY294002（PI3K/Akt/mTOR信号转导通路抑制剂），正常组和实验组大鼠给予鞘内注射等体积无菌蒸馏水。采用联合行为评分（CBS）法对各组大鼠后肢运动能力进行评定；采用RT-PCR和免疫组织化学法检测损伤节段脊髓组织PI3K/Akt/mTOR信号转导通路活性的改变。结果 在实验组，随着损伤时间的延长，大鼠双侧后肢运动功能好转，CBS评分降低；损伤节段脊髓组织中，PI3K、Akt、mTOR mRNA的相对表达量上调，PI3K、Akt、mTOR蛋白表达阳性细胞数增多。与伤后7 d组比较，对照组大鼠双侧后肢肌力恢复及运动功能均较差，损伤节段脊髓组织PI3K、Akt、mTOR mRNA的相对表达量及蛋白表达阳性细胞数较少。结论 PI3K/Akt/mTOR信号转导通路与大鼠SCI早期神经功能重建有关，可以作为临床治疗的靶点。

关键词: 脊髓损伤, PI3K/Akt /mTOR信号转导通路, RT-PCR, 免疫组织化学

Abstract:

Objective To explore changes of the activity of PI3K/Akt/mTOR signaling pathway in early stage of spinal cord injury (SCI) of rats and the effects on the recovery of motor function of posterior limbs. Methods SD rats were randomly divided into the normal group, control group, and 4 experiment groups (1 d, 3 d, 5 d and 7 d after SCI groups). The Allen’s WD-SCI model was established for rats of the control group and experiment groups. Then 20 μL LY294002 (inhibitor of PI3K/Akt/mTOR signaling pathway) and 20 μL sterile purified water were intrathecally injected into the rats of control group and other groups. The combine behavioral score (CBS) method was adopted to evaluate the motor function of posterior limbs. The changes of the activity of PI3K/Akt/mTOR signaling pathway of spinal cord tissue of injured segments were detected by the RT-PCR and immunohistochemistry assay. Results For experiment groups, the motor function of both posterior limbs improved and the CBS scores declined with time after SCI. The relative mRNA expressions of PI3K, Akt, and mTOR in spinal cord tissue of injured segments upregulated and the number of cells with positive expression of PI3K, Akt, and mTOR proteins increased. Compared with rats of the 7 d after SCI group, the recovery of muscle strength and motor function of both posterior limbs of the control group were poor, and the relative mRNA expressions of PI3K, Akt, and mTOR and the number of cells with positive expression of PI3K, Akt, and mTOR proteins in spinal cord tissue of injured segments decreased. Conclusion PI3K/Akt/mTOR signaling-pathway is relevant to the reconstruction of nerve function in early-phase of SCI and can be used as a target of clinical treatment.

Key words: spinal cord injury, PI3K/Akt/mTOR signaling-pathway, RT-PCR, immunohistochemistry