Experiment Study On Repairing Spinal Cord Injury By Over-express CXCR4Human Umbilical Mesenchymal Stem Cells Transplantation

ObjectiveTo constructed acute spinal cord injury (SCI) model rat, CXCR4over-expres sed human umbilicalcord mesenchymalstem cells(hUC-MSCs) were transplanted through tail vein. To observe the migration of CXCR4over-expressed hUC-M SCs, assess its therapeutic effects through behavioral and histological methods. And also investigate the mechanisms of CXCR4over-expression hUC-MSCs ce11migration in spinal cord injury.Method1. To observe time and space distribution of CXCR4in vivo:rat SCI model was established through IMPACTOR MODEL-Ⅱin T10level. IHC was used to assess the expression of CXCR4in different time and position. Appropriate time to transplant CXCR4-hUC-MSCs through tail vein was then confirmed.2. Study the migration of CXCR4-hUC-MSCs in vivo:the SCI rats were divided into3groups; cells were injected through tail vein, and GFP expression was assessed by fluorescence.3. To assess the therapeutic effects of CXCR4-hUC-MSCs to SCI:SCI rat model was divided to5groups, BBB score was used to assess the functional recovery of lower limbs motitor. The animals were sacrificed8weeks later, and specimens were obtained from the injured spinal cord, then HE, TUNEL, NF-200, GFAP staining was performed. Data were statistically analyzed at last.Results1. Highest expression of CXCR4was observed in the3rd day after spinal cord injury, which indicated the best transplant time.2. The CXCR4-hUC-MSCs were detected at SCI tissues which were proved by fluorescence results.3. Compared to the control group, tail vein group showed less syringomyelia area by HE (p<0.05), higher BBB score (p<0.05), and lower apoptosis rate (p<0.05)Conclusions1. CXCR4can promotes cells migration in vivo. Tail vein transplant exhibits targeting migration ability. 2. CXCR4-hUC-MSCs migrate to SCI tissues when transplanted in appropriate time.3. CXCR4shows therapeutic effect to SCI, which combined with hUC-MSCs can fill the spinal cord defect and reduce syringomyelia, CXCR4-hUC-MSCs are benefical to SCI.4. This study integrated in all aspects of the experimental results, served as the theoretical basis to intravenous transplant of CXCR4-hUC-MSCs for spinal cord injury repair.