Neuroprotective effect of tetramethylpyrazine on mice after spinal cord injury / 中国中药杂志

This study aims to investigate the neuroprotective effect of tetramethylpyrazine on mice after spinal cord injury and its mechanism. Seventy-five female C57BL/6 mice were randomly divided into 5 groups, namely, a sham operation group, a model group, a tetramethylpyrazine low-dose group(25 mg·kg~(-1)), a tetramethylpyrazine medium-dose group(50 mg·kg~(-1)), and a tetramethylpyrazine high-dose group(100 mg·kg~(-1)), with 15 mice in each group. Modified Rivlin method was used to establish the mouse model of acute spinal cord injury. After 14 d of tetramethylpyrazine intervention, the motor function of hind limbs of mice was evaluated by basso mouse scale(BMS) and inclined plate test. The levels of inflammatory cytokines tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), and interleukin-1β(IL-1β) in the spinal cord homogenate were determined by enzyme-linked immunosorbent assay(ELISA). Hematoxylin-eosin(HE) staining was used to observe the histology of the spinal cord, and Nissl's staining was used to observe the changes in the number of neurons. Western blot and immunofluorescence method were used to detect the expression of glial fibrillary acidic protein(GFAP) and C3 protein. Tetramethylpyrazine significantly improved the motor function of the hind limbs of mice after spinal cord injury, and the BMS score and inclined plate test score of the tetramethylpyrazine high-dose group were significantly higher than those of the model group(P<0.01). The levels of TNF-α, IL-6, and IL-1β in spinal cord homogenate of the tetramethylpyrazine high-dose group were significantly decreased(P<0.01). After tetramethylpyrazine treatment, the spinal cord morphology recovered, the number of Nissl bodies increased obviously with regular shape, and the loss of neurons decreased. As compared with the model group, the expression of GFAP and C3 protein was significantly decreased(P<0.05,P<0.01) in tetramethylpyrazine high-dose group. In conclusion, tetramethylpyrazine can promote the improvement of motor function and play a neuroprotective role in mice after spinal cord injury, and its mechanism may be related to inhibiting inflammatory response and improving the hyperplasia of glial scar.

Experimental Advance in Seed Cells and Biological Scaffolds for Spinal Cord Tissue Engineering (review) / 中国康复理论与实践

Objective:To explore the problems of seed cells and biological scaffolds in spinal cord tissue engineering, and review the recent experimental research. Methods:Related literatures were searched in CNKI, Wangfang data, PubMed and Web of Science from establishment to March, 2021, and the problems and progress of seed cells, biological scaffolds and their combination were reviewed. Results:The problems of seed cells are carcinogenicity, immune rejection, ethics, low survival rate and differentiation rate after transplantation, and current researches focus on exploring new cell types, gene transfection, cell co-transplantation and pretreatment before transplantation. The problems of biological scaffold are that a single material selection cannot meet different needs, and the traditional technology cannot simulate the internal structure of spinal cord well. There were more researches focusing on new composite materials and new technology. The core problem of their combination is that the effects of different cell and scaffold combinations are different, and the current researches are mostly devoted to the continuous exploration of suitable composite mode, and try to introduce biological agents and other factors. Conclusion:Spinal cord tissue engineering has the potential to completely change the therapeutic pathway of spinal cord injury. Current experimental researches mainly base on solving the problems of seed cells and biological scaffolds of spinal cord tissue engineering, and further explore the appropriate composite mode of seed cells and biological scaffolds, so as to provide more basic evidence for its clinical application.

Co-culture of Neural Stem Cells and Spinal Cord Acellular Scaffold in Vitro / 中国康复理论与实践

Objective:To observe the adhesion, growth and differentiation of rat neural stem cells (NSCs) on spinal cord acellular scaffold (SCAS) to evaluate its feasibility for spinal cord tissue engineering. Methods:NSCs derived from neonatal Sprague-Dawley rat cerebral cortex were cultured and identified. SCAS were prepared from female Sprague-Dawley rat spinal cord tissues using modified chemical extraction and physical oscillation, and evaluated. The third generation NSCs were planted on SCAS and co-cultured, the morphology of the cells on the scaffold was observed with immunofluorescence, immunohistochemistry and scanning electron microscope. Results:The cultured cells were NSCs, which could proliferate and differentiate. The porosity, water content and enzymatic hydrolysis rates of the prepared SCAS were significantly higher than that of normal spinal cord (|t| > 4.679, P < 0.01). The matrix structure of SCAS was loosely network-like, with few residual nuclei. NSCs adhered and grew well, and differentiated into neurons and glial cells on SCAS. Conclusion:This kind of SCAS shapes multi-channel spatial structure and is suitable for NSCs adhesion, growth and differentiation, which can be used for spinal cord tissue engineering.