Transplant of Very Small Embryoniclike Stem Cells to Spinal Cord Injury in a Rat Model Promotes Movement Recovery.

Very small embryoniclike stem cells are a population of small stem cells with embryonic characteristics that were identified in adult murine bone marrow. During the past decade, researchers have examined different alternatives for functional recovery after spinal cord injury. The aim of this study was to evaluate transplant of small embryoniclike stem cells in a spinal cord injury rat model, and investigate cell migration to the lesion sites and the effects of cells on lesion size and overall functional recovery of the injured rats. Small embryoniclike stem cells were isolated from bone marrow and injected intravenously to rats with spinal cord injury. Quantification of size of cavities in injured spinal cord tissue revealed significant reduction of the size of cavities in rats transplanted with very small embryoniclike stem cells (P < .05). Florescence microscopic images from injured spinal cord tissue showed localization of DiI-labeled small embryoniclike stem cells at the lesion site at 7 weeks after transplant. Real-time reverse transcription polymerase chain reaction analyses indicated higher expression of neural markers in the rats transplanted with small embryoniclike stem cells than in the other rats that did not receive small embryoniclike stem cells (P < .05). Assessment of improvement of locomotor function in rats transplanted with small embryoniclike stem cells was noticeable at 7 weeks after injury. Small embryoniclike stem cells may be a good source of stem cells for transplant into injured tissue of rat spinal cord for regeneration because they contain both embryonic and adult stem cell characteristics.