Jevans Benjamin, James Nicholas D, Burnside Emily, McCann Conor J, Thapar Nikhil, Bradbury Elizabeth J, Burns Alan J
Stem Cells and Regenerative Medicine, UCL Great Ormond Street Institute of Child Health, London, UK.
Present Address: German Centre for Neurodegenerative diseases (DZNE), Bonn, Germany.
Stem Cell Res Ther. 2021 Jan 6;12(1):10. doi: 10.1186/s13287-020-02031-9.
Spinal cord injury (SCI) presents a significant challenge for the field of neurotherapeutics. Stem cells have shown promise in replenishing the cells lost to the injury process, but the release of axon growth-inhibitory molecules such as chondroitin sulfate proteoglycans (CSPGs) by activated cells within the injury site hinders the integration of transplanted cells. We hypothesised that simultaneous application of enteric neural stem cells (ENSCs) isolated from the gastrointestinal tract, with a lentivirus (LV) containing the enzyme chondroitinase ABC (ChABC), would enhance the regenerative potential of ENSCs after transplantation into the injured spinal cord.
ENSCs were harvested from the GI tract of p7 rats, expanded in vitro and characterised. Adult rats bearing a contusion injury were randomly assigned to one of four groups: no treatment, LV-ChABC injection only, ENSC transplantation only or ENSC transplantation+LV-ChABC injection. After 16 weeks, rats were sacrificed and the harvested spinal cords examined for evidence of repair.
ENSC cultures contained a variety of neuronal subtypes suitable for replenishing cells lost through SCI. Following injury, transplanted ENSC-derived cells survived and ChABC successfully degraded CSPGs. We observed significant reductions in the injured tissue and cavity area, with the greatest improvements seen in the combined treatment group. ENSC-derived cells extended projections across the injury site into both the rostral and caudal host spinal cord, and ENSC transplantation significantly increased the number of cells extending axons across the injury site. Furthermore, the combined treatment resulted in a modest, but significant functional improvement by week 16, and we found no evidence of the spread of transplanted cells to ectopic locations or formation of tumours.
Regenerative effects of a combined treatment with ENSCs and ChABC surpassed either treatment alone, highlighting the importance of further research into combinatorial therapies for SCI. Our work provides evidence that stem cells taken from the adult gastrointestinal tract, an easily accessible source for autologous transplantation, could be strongly considered for the repair of central nervous system disorders.
脊髓损伤（SCI）对神经治疗领域构成重大挑战。干细胞在补充因损伤过程而丢失的细胞方面显示出前景，但损伤部位内活化细胞释放的轴突生长抑制分子，如硫酸软骨素蛋白聚糖（CSPG），阻碍了移植细胞的整合。我们假设，将从胃肠道分离的肠神经干细胞（ENSC）与含有软骨素酶ABC（ChABC）的慢病毒（LV）同时应用，会增强ENSC移植到损伤脊髓后的再生潜力。
从出生7天大鼠的胃肠道中获取ENSC，在体外进行扩增并鉴定。对成年大鼠造成挫伤性损伤后，将其随机分为四组之一：不治疗、仅注射LV-ChABC、仅进行ENSC移植或ENSC移植+LV-ChABC注射。16周后，处死大鼠并检查收获的脊髓以寻找修复证据。
ENSC培养物包含多种适合补充因SCI而丢失细胞的神经元亚型。损伤后，移植的ENSC来源细胞存活，且ChABC成功降解了CSPG。我们观察到损伤组织和空洞面积显著减小，联合治疗组改善最为明显。ENSC来源细胞的突起穿过损伤部位延伸至头端和尾端的宿主脊髓，且ENSC移植显著增加了穿过损伤部位延伸轴突的细胞数量。此外，联合治疗在第16周时导致了适度但显著的功能改善，且我们未发现移植细胞扩散到异位位置或形成肿瘤的证据。
ENSC与ChABC联合治疗的再生效果超过单独任何一种治疗，突出了进一步研究SCI联合疗法的重要性。我们的工作提供了证据，表明取自成年胃肠道的干细胞作为自体移植的便捷来源，可被强烈考虑用于中枢神经系统疾病的修复。
