In vitro differentiation potential of human urine-derived stem cells into neuron-like cells and their protective effects against spinal cord injury in rats / 中国组织工程研究

ABSTRACT

BACKGROUND: Human urine-derived stem cells are newly discovered adult stem cells, characterized by rich sources, simple extraction, good proliferative ability and multi-directional differentiation potential. In recent years, human urine-derived stem cells have been used for the repair of neurological functions in urinary diseases, such as stress urinary incontinence and vesicoureteral reflux. OBJECTIVE: To explore the biological characteristics of human urine-derived stem cells and to study their repairing effect in a rat model of spinal cord injury. METHODS: Cell phenotypes of human urine-derived stem cells were detected using flow cytometry, and the immunohistochemical staining was used to identify neuron-like cells differentiated from human urine-derived mesenchymal stem cells. Then, an animal model of spinal cord injury at T9 segment was made by Allen method, and after modeling 24 Sprague-Dawley rats were assigned into spinal cord injury group or cell treatment group (n=12/group). In the cell treatment group, the model rats were injected 2 μL of 1.0×1011/L human urine-derived stem cells, while in the spinal cord injury group, the rats were administered the same volume of L-DMEM containing 10% fetal bovine serum. Basso, Beattie and Bresnahan scores were valued at 1, 10, 20, and 30 days after modeling. Spinal cord samples from all the rats were taken out at 30 days after modeling, and Luxol Fast Blue staining, microglia/macrophages staining and glial fibrillary acidic protein staining were used to value the injured area of the spinal cord and the fluorescence intensity of glial fibrillary acidic protein. RESULTS AND CONCLUSION: (1) Flow cytometry showed high expression on CD29 and CD90, and low expression on CD45 in human urine-derived mesenchymal stem cells. Moreover, human urine-derived mesenchymal stem cells could be induced to differentiating into neuron-like cells in vitro. (2) Basso, Beattie and Bresnahan scores showed no significant difference between the two groups at 1 and 10 days after modeling (P > 0.05), while, at 20 and 30 days after modeling, the scores in the cell treatment group were significantly higher than those in the spinal cord injury group (P < 0.05). (3) Luxol Fast Blue staining showed that the injured area of the spinal cord in the cell treatment group was markedly less than that in the spinal cord injury group (P < 0.05), and the glial fibrillary acidic protein showed lower fluorescence intensity in the cell treatment group than the spinal cord injury group (P < 0.05). To conclude, human urine-derived stem cells can differentiate into neuron-like cells and have therapeutic effects in the rat model of spinal cord injury.