Human umbilical cord mesenchymal stem cell transplantation for the treatment of two noncontinuous segments spinal cord compression injury in rabbits

Abstract

Objective: In order to explore the effects of human umbilical cord mesenchymal stem cells (UCMSC) transplantation on the treatment of two noncontinuous segments spinal cord compression injury and to investigate whether repeated intravenous injection UCMSC was more beneficial for the recovery of spinal cord function. Methods: A total of 30 adult rabbits were randomly divided into three groups: control group (received PBS), single injection group, repeated injection group with 3 days intervals. A noncontinuous two segments SCI model was established by using the 2F Fogarty balloon catheter. Rabbits were infused with either a single total dose or three divided doses of 2×10(6) UCMSC (3 intervals) at first day post-decompreesion. Behavioral scores, somatosensory evoked potentials (SSEP) and histopathological were used to evaluate therapeutic effects. The rates of stem cell homing were studied by immunofluorescence test and the apoptosis of the spinal cord was evaluated by TUNEL test. Results: Behavior alanalyses showed that the rabbits in the UCMSC injection groups showed better motor performance than those in the control group (P<0.01), and the motor performance in the repeated transplantation group was better than that in the single transplantation group (P<0.01). The SSEP latencies were (22.53±0.75) ms, (24.52±0.45) ms and (26.31±0.69) ms in the repeated injection group, single injection group and control group (all P<0.01), respectively. Treatment with UCMSC increased ventral horn motor neurons preservation and decreased the number of TUNEL-positive cells compared with control group (P<0.01). The rates of stem cell homing in the repeated injection group was significantly higher than that in single injection group (P<0.01). Conclusion: Transplantation of UCMSC after spinal cord compression injury of two noncontinuous segments can promote functional recovery through enhancement anti-apoptotic and neuroprotective effects, and the recovery was more pronounced in the rabbits repeatedly injected at 3-day intervals.