中国神经再生研究(英文版) ›› 2021, Vol. 16 ›› Issue (7): 1281-1287.doi: 10.4103/1673-5374.301032

• 原著:脊髓损伤修复保护与再生 • 上一篇    下一篇

临床前脊髓运动神经元损伤模型的建立

  

  • 出版日期:2021-07-15 发布日期:2021-01-07
  • 基金资助:
    新泽西脊髓研究委员会(05-3047; 11-015)资助

Suicide transport blockade of motor neuron survival generates a focal graded injury and functional deficit

Allison S. Liang1, Joanna E. Pagano1, Christopher A. Chrzan1, Randall D. McKinnon1, 2, *   

  1. 1 Department of Neurosurgery, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ, USA;  2 Member, The Cancer Institute of New Jersey, New Brunswick, NJ, USA
  • Online:2021-07-15 Published:2021-01-07
  • Contact: Randall D. McKinnon, PhD, mckinnon@rwjms.rutgers.edu.
  • Supported by:
    Supported by grants to Dr McKinnon (PI) from the New Jersey Commission on Spinal Cord Research (05-3047; 11-015).

摘要:

实验旨在建立一种临床前的脊髓运动神经元损伤模型,该模型具有微创性,可重复性,局灶性,并且易于应用于小型啮齿动物。实验将促凋亡的磷脂酰肌醇3’-激酶抑制剂渥曼青霉素注射至小鼠左侧坐骨神经以建立前面提到的脊髓运动神经元损伤模型。胆碱乙酰基转移酶(ChAT)免疫染色和转基因thy1-eGFP标记检测结果显示,坐骨神经(Sn)逆行轴突转运促凋亡的磷脂酰肌醇3’-激酶抑制剂渥曼青霉素致同侧腰部运动神经元丢失,且丢失程度与药物剂量呈正比。共同注射的假狂犬病病毒示踪剂显示,渥曼青霉素不影响轴突运输。定量PCR检测显示,ChAT转录水平在渥曼青霉素注射后14d显著降低,且在90d后仍保持较低水平。14d后,渥曼青霉素使星形胶质细胞Gfap转录物的瞬时显著增加,并在90天时恢复到对照水平。出水测试中渥曼青霉素干预小鼠表现为后肢痉挛和运动功能障碍,这种表现持续了至少3个月。因此,渥曼青霉素的局部递送对运动神经元的神经毒性作用持续时间持久,可用于建立可靠的脊髓运动神经元损伤模型。

https://orcid.org/0000-0002-7539-9613 (Randall D. McKinnon) 

Abstract: We describe a pre-clinical spinal cord motor neuron injury model that is minimal invasive, reproducible, focal and easily applied to small rodents. Retrograde axonal transport of a pro-apoptotic phosphatidylinosotol 3’-kinase inhibitor, wortmannin, via the sciatic nerve results in loss of ipsilateral lumbar motor neurons proportional to the level of drug administered. Motor neuron loss was detected by choline acetyltransferase (ChAT) immunostaining and with a transgenic thy1-eGFP marker. The short half-life of wortmannin generates minimal wound spread, and wortmannin does not affect axon transport, as determined by co-injection of a pseudorabies virus tracer. Using quantitative transcript analysis, we found that ChAT transcripts significantly decreased at 14 days post-delivery of 1 μg wortmannin, relative to sham controls, and remained low after 90 days. Smaller effects were observed with 200 ng and 100 ng wortmannin. Wortmannin also generated a transient and significant increase in astrocyte Gfap transcripts after 14 days with a return to control levels at 90 days. Treated mice had hind limb spasticity and a forced motor function defect that was quantified using a water exit test. Controls rapidly exit a shallow water tray, and wortmannin treated animals were up to 12-fold slower, a phenotype that persisted for at least 3 months. Thus the focal delivery of wortmannin to motor neurons generates a reproducible and scalable injury that can facilitate quantitative studies on neural regeneration and repair. The efficacy of sciatic nerve suicide transport can also explain neurotoxin-mediated selective loss of motor neurons in diseases such as amyotrophic lateral sclerosis. All procedures were performed at Rutgers under established Institutional Animal Care and Use protocols (eIACUC_TR201800022, approved on March 20, 2018). 

Key words: amyotrophic lateral sclerosis, injury, motor function, motor neuron, PI3’kinase, sciatic nerve, suicide transport, wortmannin