Transplantation of Human Amniotic Mesenchymal Stem Cells Promotes Functional Recovery in a Rat Model of Traumatic Spinal Cord Injury

Human amniotic membrane mesenchymal stem cells (hAMSCs) are considered ideal candidate stem cells for cell-based therapy. In this study, we assessed whether hAMSCs transplantation promotes neurological functional recovery in rats after traumatic spinal cord injury (SCI). In addition, the potential mechanisms underlying the possible benefits of this therapy were investigated. Female Sprague-Dawley rats were subjected to SCI using a weight drop device and then hAMSCs, or phosphate-buffered saline (PBS) were immediately injected into the contused dorsal spinal cord at 2 mm rostral and 2 mm caudal to the injury site. Our results indicated that transplanted hAMSCs migrated in the host spinal cord without differentiating into neuronal or glial cells. Compared with the control group, hAMSCs transplantation significantly decreased the numbers of ED1(+) macrophages/microglia and caspase-3(+) cells. In addition, hAMSCs transplantation significantly increased the levels of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in the injured spinal cord, and promoted both angiogenesis and axonal regeneration. These effects were associated with significantly improved neurobehavioral recovery in the hAMSCs transplantation group. These results show that transplantation of hAMSCs provides neuroprotective effects in rats after SCI, and could be candidate stem cells for the treatment of SCI.