局部注射骨髓间充质干细胞治疗大鼠脊髓损伤：运动功能有改善吗？

背景：目前研究多为骨髓间充质干细胞的体外培养及细胞移植对颅内疾病的治疗，对植入细胞在损伤脊髓中的成活、分化、迁移、结构重建等了解有限。 目的：探讨局部骨髓间充质干细胞移植在脊髓损伤修复中的作用和骨髓间充质干细胞替代治疗的可行性。 方法：成年健康雌性SD大鼠随机分为细胞移植组和对照组，建立SD大鼠脊髓横断损伤模型，伤后即刻分别向损伤区局部移植大鼠骨髓间充质干细胞悬液或无钙镁磷酸缓冲液。在术前和术后1 d，1周，2周，3周，4周和8周进行BBB评分，观测大鼠的运动功能，并于移植后1周免疫组织化学染色法观察BrdU标记的骨髓间充质干细胞在脊髓损伤处的存活情况，移植后4周进行损伤脊髓的大体观察和组织学检测。 结果与结论：移植后第1~8周细胞移植组BBB评分均髙于对照组；术后1周免疫组织化学染色结果显示在细胞移植组大鼠脊髓远端检测到BrdU阳性细胞，术后4周脊髓损伤处发现有神经纤维。证实通过损伤后立即局部注射的方式将骨髓间充质干细胞移植进大鼠脊髓损伤区，细胞可在损伤区存活；存活的骨髓间充质干细胞可分化为神经元，在损伤局部形成神经元通路，从而促进脊髓神经纤维传导功能的恢复，并促进高位脊髓损伤后大鼠后肢运动功能恢复。

Injury after local injection of bone marrow stem cell therapy for spinal cord injury in rat experimental study

BACKGROUND: Present studies mainly focused on in vitro culture of bone marrow mesenchymal stem cells (BMSCs) and cell transplantation for treating intracalvarium diseases. However, the understanding of survival, differentiation, migration and structure of transplanted cells in the damaged spinal cord is limited. OBJECTIVE: To explore effects of local BMSC transplantation in repair of spinal cord damage and feasibility of replacement therapy of BMSCs. METHODS: Adult healthy female Sprague-Dawley rats were randomly assigned to cell transplantation and control groups. Rat models of spinal cord transection damage were established. Rat BMSC suspension or calcium and magnesium phosphate buffer were transplanted immediately after injury to the damage zone. At 1 day, 1, 2, 3, 4 and 8 weeks before and after transplantation, BBB score motor function was observed in rats, and at 1 week after transplantation, immunohistochemical staining was utilized to observe BrdU-labeled BMSC survival in the spinal cord damaged site. At 4 weeks after transplantation, the general observation and histological detection were observed. RESULTS AND CONCLUSION: At 1-8 weeks after transplantation, BBB scores were higher in the cell transplantation group than in the control group. At 1 week following surgery, immunohistochemical staining showed that BrdU-positive cells were detected in the distal end of rat spinal cord in the cell transplantation group. At 4 weeks following surgery, nerve fibers were found in the damaged spinal cord. These verified that BMSCs were transplanted into rat damaged spinal cord immediately following damage, and the transplanted cells could survive. Living BMSCs can differentiate into neurons, and formed neuron pathway in the local region of damage, which will promote the recovery of conduction function of spinal nerve fibers, and contribute to the recovery of rat hindlimb motor function following high-level spinal cord injury.