Direct remyelinating effect of bone marrow mesenchymal stem cells in the rat model of spinal cord injury

摘要

Background:Several studies have tried to evaluate the effects of stem cell therapy for spinal cord injury in animal models and human trials.Bone marrow mesenchymal stem cells are one of the safe and available candidate cells with established beneficial therapeutic effects for bone and cartilage repair.However,there are some doubts regarding their therapeutic efficacy for nervous system disorders.Bone marrow mesenchymal stem cells have been used in some clinical trials for spinal cord injury but their precise mechanism of action and also their safety has not been investigated.Available experimental reports do not provide sufficient and convincing evidence to persuade therapists to perform further clinical trials.In the present study we have used detailed staining methods to clearly show the entire structure of the injured spinal cord and the effects of bone marrow mesenchymal stem cells treatment on this tissue.Methods:Intrathecal injection of neutral red stained bone marrow mesenchymal stem cells were done in a rat model of spinal cord injury and the fate of the transplanted cells,immunologic responses in the host tissue,and tumor generation were assessed by using brightfield and fluorescence microscopy.Sensory-motor functions were also evaluated in the animals.Results:Injected cells could migrate to the site of the injury and differentiate into oligodendrocytes and astrocytes.Immuno-histological assays showed no cells expressing CD2,CD3,CD15 and CD45 in host tissues,and sensory-motor assessments revealed that there were some partial improvements.Conclusion:Present study provides strong evidence that mesenchymal stem cell therapy is safe and could be helpful for the remyelination of injured nerve fibers in the acute phase of injury.