Mesenchymal Stem Cell-Based Therapy Improves Lower Limb Movement After Spinal Cord Ischemia in Rats

Abstract

Spinal cord ischemia is a devastating complication after thoracic and thoracoabdominal aortic operations. In this study, we aimed to investigate the effects of mesenchymal stem cells (MSCs), which have regenerative capability and exert paracrine actions on damaged tissues, injected into rat models of spinal cord ischemia-reperfusion injury. Forty-five Sprague-Dawley rats were divided into sham, phosphate-buffered saline (PBS), and MSC groups. Spinal cord ischemia was induced in the latter two groups by balloon occlusion of the thoracic aorta. MSCs and PBS were then immediately injected into the left carotid artery of the MSC and PBS groups, respectively. Hindlimb motor function was evaluated at 6 and 24 hours. The spinal cord was removed at 24 hours after ischemia-reperfusion injury, and histologic and immunohistochemical analyses and real-time polymerase chain reaction assessments were performed. Rats in the MSC and PBS groups showed flaccid paraparesis/paraplegia postoperatively. Hindlimb function was significantly better at 6 and 24 hours after ischemia-reperfusion injury in the MSC group than in the PBS group (p < 0.05). The number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive neuron cells in the spinal cord and the ratio of Bax to Bcl2 were significantly larger (p < 0.05) in the PBS group than in the MSC group. The injected MSCs were observed in the spinal cord 24 hours after ischemia-reperfusion injury. The MSC therapy by transarterial injection immediately after spinal cord ischemia-reperfusion injury may improve lower limb function by preventing apoptosis of neuron cells in the spinal cord.