Neural Regeneration Research ›› 2017, Vol. 12 ›› Issue (9): 1507-1518.doi: 10.4103/1673-5374.215263

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Methotrexate combined with methylprednisolone for the recovery of motor function and differential gene expression in rats with spinal cord injury

Jian-tao Liu1, Si Zhang1, Bing Gu1, Hua-nan Li2, Shuo-yu Wang2, Shui-yin Zhang1   

  1. 1 Jiangxi Key Laboratory of Bioprocess Engineering, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi Province, China
    2 Department of Spine Surgery, Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi Province, China
  • Received:2017-08-12 Online:2017-09-15 Published:2017-09-15
  • Contact: Bing Gu, Ph.D.,bguemory@hotmail.com.
  • Supported by:

    This research was supported by the National Natural Science Foundation of China, No. 30960448; the Natural Science Foundation of Jiangxi Province, No. 20142BAB205023; the Ph.D. Start-up Fund of Natural Science Foundation of Jiangxi Science & Technology Normal University in China, No. 3000990122.

Abstract:

Methylprednisolone is a commonly used drug for the treatment of spinal cord injury, but high doses of methylprednisolone can increase the incidence of infectious diseases. Methotrexate has anti-inflammatory activity and immunosuppressive effects, and can reduce inflammation after spinal cord injury. To analyze gene expression changes and the molecular mechanism of methotrexate combined with methylprednisolone in the treatment of spinal cord injury, a rat model of spinal cord contusion was prepared using the PinPoint™ precision cortical impactor technique. Rats were injected with methylprednisolone 30 mg/kg 30 minutes after injury, and then subcutaneously injected with 0.3 mg/kg methotrexate 1 day after injury, once a day, for 2 weeks. TreadScan gait analysis found that at 4 and 8 weeks after injury, methotrexate combined with methylprednisolone significantly improved hind limb swing time, stride time, minimum longitudinal deviation, instant speed, footprint area and regularity index. Solexa high-throughput sequencing was used to analyze differential gene expression.Compared with methylprednisolone alone, differential expression of 316 genes was detected in injured spinal cord treated with methotrexate and ethylprednisolone. The 275 up-regulated genes were mainly related to nerve recovery, anti-oxidative, anti-inflammatory and anti-apoptotic functions, while 41 down-regulated genes were mainly related to proinflammatory and pro-apoptotic functions. These results indicate that methotrexate combined with methylprednisolone exhibited better effects on inhibiting the activity of inflammatory cytokines and enhancing antioxidant and anti-apoptotic effects and thereby produced stronger neuroprotective effects than methotrexate alone. The 316 differentially expressed genes play an important role in the above processes.
 

Key words: nerve regeneration, spinal cord injury, methotrexate, methylprednisolone, gait, gene expression profile, inflammation, oxidative stress, apoptosis, nerve repair, Solexa gene sequencing, secondary lesion, neural regeneration