中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2018, Vol. 13 ›› Issue (12): 2191-2199.doi: 10.4103/1673-5374.241473

• 原著:脊髓损伤修复保护与再生 • 上一篇    下一篇

锂剂通过诱导自噬促进脊髓损伤后神经功能的恢复

  

  • 收稿日期:2018-08-22 出版日期:2018-12-15 发布日期:2018-12-15
  • 基金资助:

    中国北京优秀人才培养基金（2017000021469G215）(DZ)；中国北京天坛医院青年科学基金（）2016-YQN-14）(DZ)；首都医科大学自然科学基金（PYZ2017082）(DZ)；西安科技项目（2016048SF/YX 04(3) ）(XHL)

Lithium promotes recovery of neurological function after spinal cord injury by inducing autophagy

Duo Zhang1, Fang Wang2, Xu Zhai3, Xiao-Hui Li4, Xi-Jing He2   

  1. 1 Department of Orthopedics, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
    2 Department of Orthopedics, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi Province, China
    3 Department of Emergency, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi Province, China
    4 Department of Radiology, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi Province, China
  • Received:2018-08-22 Online:2018-12-15 Published:2018-12-15
  • Contact: Duo Zhang, MD, zhangduo-88@163.com; Xi-Jing He, MD, xijing_h@vip.tom.com.
  • Supported by:

    This study was supported by the Beijing Excellent Talent Training Funding in China, No. 2017000021469G215 (to DZ); the Youth Science Foundation of Beijing Tiantan Hospital of China, No. 2016-YQN-14 (to DZ); the Natural Science Foundation of Capital Medical University of China, No. PYZ2017082 (to DZ); the Xi’an Science and Technology Project in China, No. 2016048SF/YX04(3) (to XHL).

PDF

301

摘要：

有研究表明，锂剂具有较强的神经保护作用，在促进细胞自噬过程中可发挥重要作用，锂剂对脊髓损伤(SCI)也有治疗作用，但其作用机制目前仍不清楚。因此，试验拟观察锂剂和自噬抑制剂3-甲基腺嘌呤(3-methyladenine，3-MA)对SCI的影响。为明确锂剂是否通过促进自噬发挥作用，实验建立脊髓打击损伤大鼠模型，随机分为SCI组、锂剂治疗组(SCI+锂剂)、3-MA干预组(SCI+3-MA)，同时设假手术组作对照。(1)3-MA组大鼠在SCI前2 h腹腔注射3-MA(3 mg/kg)；锂剂治疗组和3-MA干预组在SCI后6 h腹腔注射锂剂(LiCl 30 mg/kg)，随后每日注射1次；(2)SCI后2，3，4周，锂剂治疗组大鼠在神经功能及DTI检查指标方面较SCI组和3-MA干预组明显改善(BBB评分和FA值升高，ADC值下降)，而3-MA干预组在SCI后3，4周上述指标较SCI组明显改善。锂剂治疗组和SCI组在SCI后1 d免疫组织染色结果检测的自噬标记蛋白Beclin-1和LC3b免疫反应达到高峰，而3-MA干预组较SCI组明显减弱，说明3-MA抑制了锂剂的促自噬作用；(3)免疫组织化学染色显示，锂剂治疗组脊髓组织较SCI组和3-MA干预组有更多NeuN(一个神经元标记物)阳性细胞存活，而SCI组存活NeuN阳性细胞较3-MA干预组更多；(4)结果证实，锂剂通过诱导自噬，减轻急性SCI后的神经元损伤，促进神经功能恢复，而其发挥神经保护作用的机制可能不完全依赖促进自噬作用，或者3-MA不能完全抑制自噬所有通路。

orcid:0000-0001-9011-4316(Duo Zhang)
        0000-0002-0465-5376(Xi-Jing He)

关键词: 脊髓损伤, 锂, 继发性损伤, 自噬, 扩散张量成像, 神经保护, 功能恢复, 免疫组织化学, Beclin-1, 轻链-3B

Abstract:

Lithium promotes autophagy and has a neuroprotective effect on spinal cord injury (SCI); however, the underlying mechanisms remain unclear. Therefore, in this study, we investigated the effects of lithium and the autophagy inhibitor 3-methyladenine (3-MA) in a rat model of SCI. The rats were randomly assigned to the SCI, lithium, 3-MA and sham groups. In the 3-MA group, rats were intraperitoneally injected with 3-MA (3 mg/kg) 2 hours before SCI. In the lithium and 3-MA groups, rats were intraperitoneally injected with lithium (LiCl; 30 mg/kg) 6 hours after SCI and thereafter once daily until sacrifice. At 2, 3 and 4 weeks after SCI, neurological function and diffusion tensor imaging indicators were remarkably improved in the lithium group compared with the SCI and 3-MA groups. The Basso, Beattie and Bresnahan locomotor rating scale score and fractional anisotropy values were increased, and the apparent diffusion coefficient value was decreased. Immunohistochemical staining showed that immunoreactivities for Beclin-1 and light-chain 3B peaked 1 day after SCI in the lithium and SCI groups. Immunoreactivities for Beclin-1 and light-chain 3B were weaker in the 3-MA group than in the SCI group, indicating that 3-MA inhibits lithium-induced autophagy. Furthermore, NeuN+ neurons were more numerous in the lithium group than in the SCI and 3-MA groups, with the fewest in the latter. Our findings show that lithium reduces neuronal damage after acute SCI and promotes neurological recovery by inducing autophagy. The neuroprotective mechanism of action may not be entirely dependent on the enhancement of autophagy, and furthermore, 3-MA might not completely inhibit all autophagy pathways.

Key words: nerve regeneration, spinal cord injury, lithium, secondary injury, autophagy, diffusion tensor imaging, neuroprotection, functional recovery, immunohistochemistry, Beclin-1, light-chain 3B, neural regeneration