Experimentation of acute injured spinal cord by transplanting the bone marrow stromal cells

Abstract

Objective: In this study, bone marrow stromal cells (BMSCs) were transplanted in situ after spinal cord injury (SCI) in rats. It was proved that the implanted BMSCs could differentiate into neuron-like cells in the injured spinal cord, and the long-term motor ability test was carried out to investigate the recovery of neurological dysfunction after transplantation.

Methods: (1) An improved Alien’s SCI rat model (weight 10 g, height 30 mm) was made by Alien weight drop method. Methyl eosin (Haematoxyli - n/eosin, HE) was used to identify with SCI. (2) The BMSCs were identified by the method of bone marrow adherent culture in vitro. The morphology of the cells was observed by cell staining, and CD44 was detected by BMSCs. After three cultures, the cells were transfected with lentiviral vectors carrying Green Fluorescent Protein (GFP) gene. (3) Cell survival after passage and transplantation: the GFP labeled BMSCs in situ (injury zone) were implanted into the injury model. The spinal cord sections were sacrificed after 2 weeks (2w), 4 weeks (4w) and 6 weeks (6w) respectively, and the cells expressing GFP were observed under immunofluorescence microscope. (4) The modified Rivlin oblique plate test and spinal motor function blood brain barrir (BBB) score method were used to compare the changes of exercise ability in the simple injury group, 2w after transplantation group, 4w after transplantation group and 6w after transplantation group.

Results: (1) The Alien’s SCI rat model was made by using Alien’s heavy drop method, and the effect was reliable and stable. (2) The proliferation of BMSCs after 3 passages has stabilized. After culture and amplification in vitro, the cell morphology changed to be conical, protruding interwoven into a network. Therefore, it could be used as a source of cell transplantation after SCI. The morphology of the cells was observed by staining, and the positive CD44 was detected. (3) BMSCs were transfected into the SCI model by lentiviral vector carrying GFP gene, and the expression of GFP in 6w was observed. (4) The results of modified inclined plane test and Rivlin locomotor BBB score of rats in simple injury group were significantly worse than those in transplantation control group (p < .05). 2w, 4w and 6w after transplantation groups could improve long-term motor function. The recovery of neurological dysfunction after 6w was the best, and the difference was statistically significant (p < .05). 

Conclusions: BMSCs transplantation could promote the recovery of neurological dysfunction after SCI, and the mechanism may be related to the differentiation of BMSCs into neurons and glial cells, and the BMSCs induced by transplantation could interact with peripheral nerve cells and produce some cytokines.