天津医药

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选择性线粒体分裂抑制剂对大鼠急性脊髓损伤后神经细胞的保护作用及其机制

李刚1,范仲凯1,贾志强1,张振宇2,赵兴长2,吕刚1   

  1. 1. 辽宁医学院
    2. 辽宁医学院附属第一医院
  • 收稿日期:2014-03-25 修回日期:2014-04-03 出版日期:2014-07-15 发布日期:2014-07-15
  • 通讯作者: 李刚

Mechanism for Protective Effects of Selective Mitochondrial Fission Inhibitor on Neurons after Acute Spinal Cord Injury in Rats

  • Received:2014-03-25 Revised:2014-04-03 Published:2014-07-15 Online:2014-07-15

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摘要：

【摘要】目的 检测选择性线粒体分裂抑制剂-1（Mdivi-1）对大鼠急性脊髓损伤（ASCI）后神经细胞线粒体中丙二醛（MDA）、谷胱甘肽（GSH）、细胞色素C（Cyt-C）及神经细胞凋亡的影响。方法成年雌性SD大鼠36只，体质量 250~300g，随机分为假手术组（Sham组）、单纯脊髓损伤组（SCI组）、Mdivi-1预处理组（1.20mg/kg，Mdivi-1组），各12 只。Sham组只暴露脊髓，不打击。SCI组和Mdivi-1组采用Allen’s方法制备脊髓损伤模型。Mdivi-1组在脊髓打击之前15min尾静脉给予Mdivi-1，而SCI组给予等量二甲基亚砜（DMSO）。Sham组在暴露脊髓8h后立即处死，SCI组和Mdivi-1组均于脊髓损伤后8h处死；然后取出脊髓节段T9~T11，用分光光度计检测各组脊髓组织线粒体中MDA 和GSH的含量，Western Blot法检测线粒体及胞浆内Cyt-C表达情况，荧光TUNEL法观察神经细胞凋亡情况。结果与Sham组相比，SCI组线粒体中Cyt-C和GSH明显减少，但线粒体中的MDA，胞浆中Cyt-C及神经细胞凋亡数目明显增多（P<0.01）；与SCI组相比，Mdivi-1组线粒体中Cyt-C和GSH明显增多，但线粒体中MDA，胞浆中Cyt-C以及神经细胞凋亡数目明显减少（P<0.01）。结论Mdivi-1具有减轻ASCI后神经细胞线粒体氧化损伤，抑制线粒体中Cyt-C 的释放及神经细胞凋亡的作用，促进了脊髓功能恢复。

关键词: 急性脊髓损伤, Mdivi-1, 丙二醛, 谷胱甘肽, 细胞色素C, 细胞凋亡

Abstract:

[Abstract] Objective To detect the effects of the selective mitochondrial fission inhibitor-Mdivi-1on the malondi? alolehyde (MDA), glutathione (GSH) as well as cytochrome C (Cyt- C) in neuronal mitochondria and neuronal apoptosis. Methods Thirty-six adult female SD rats (250-300g) were randomly divided into3groups (n=12): sham operation (Sham) group, single spinal cord injury (SCI) group and Mdivi-1pretreatment (1.20mg/kg, Mdivi-1) group. In sham group, the rats’ spinal cord was exposed, but no hit. The rat model of spinal cord injury was established by Allen’s method in SCI group and Mdivi-1group. In Mdivi-1group, rats were given Mdivi-1through the tail vein 15min before spinal cord injury, and SCI group received the same amount of dimethyl sulfoxide (DMSO). Rats in Sham group were sacrificed8h after exposing spinal cord. Rats in SCI group and Mdivi-1group were sacrificed at8h after the spinal cord injury, then were removed the spinal cord T9-11. The contents of MDA and GSH in mitochondria of spinal cord tissues were detected with spectrophotometer. The expressions of Cyt- C protein in the mitochondria and cytoplasm were detected by Western blot assay. The neuronal apoptosis was assessed by TUNEL staining.Results Compared with Sham group, levels of Cyt-C and GSH in mitochondria were decreased significantly (P<0.01), while levels of MDA in mitochondria, Cyt-C in cytoplasm and the neuronal apopto? sis were increased significantly in SCI group (P<0.01). Compared with SCI group, Cyt-C and GSH levels in mitochondria were increased significantly in Mdivi-1group (P<0.01), however, MDA in mitochondria，Cyt-C in cytoplasm and the neuro? nal apoptosis were significantly reduced (P<0.01). Conclusion Mdivi-1can relieve neurons from mitochondrial oxidative damage, inhibit the release of cytochrome C and neuronal apoptosis after acute spinal cord injury, which plays a role in pro? moting the recovery of spinal cord function.

Key words: acute spinal cord injury, mdivi-1, malondialolehyde, glutathione, cytochrome C, apoptosis