脑源性神经营养因子基因转染嗅鞘细胞移植修复脊髓损伤的观察

目的观察BDNF基因转染的嗅鞘细胞（OECs）对脊髓损伤的修复作用。方法制作大鼠脊髓损伤模型，随机分为无OFCs移植组（6只）、非转染OECs移植组（6只）和转染OECs移植组（8只），利用免疫组化、逆行示踪及顺行示踪技术对脊髓横断损伤区及其上位、下位脊髓不同平面进行观察。结果移植后12周在局部注射区仍可以见到预标记的OECs，免疫组化观察到脊髓损伤区有BDNF的表达。逆行示踪法在损伤平面头侧的脊髓、脑干和皮质中观察到示踪剂。顺行示踪法在脊髓损伤区可以见到再生的神经纤维通过。无嗅鞘细胞移植组及非转染嗅鞘细胞移植组损伤平面头侧的脊髓、脑干和皮质中未观察到示踪剂，脊髓损伤区内亦未见有再生神经纤维长入。结论移植BDNF转染的OECs可促进损伤的中枢神经轴突存活和再生，较单纯应用OECs能更好地促进脊髓损伤修复。

Neuronal tracing and immunohistochemistry of BDNF gene transfected olfactory ensheathing cells transplant in spinal cord injury

Objective To evaluation of the result of transplantation of BDNF gene transfected olfactory ensheathing cells (OECs) to repair spinal cord injury (SCI). Methods The rat with SCI were divided into non-OECs, OECs and transfected OECs groups. The evidences of anatomical regeneration across the transection site were demonstrated by both neuronal tracing and immunohistochemical methods. Results 12w after implantation the retrograde labeling study with flurogold showed abundant labeled neurons in the superior part of CNS. There were a lot of labeled neurons in the intermediate zone and dorsal column of lower thoracic spinal cord rostral to the transection site. Labeled neurons were also observed in the upper thoracic and cervical spinal cord, reticular nucleus and raphe nucleus of oblongata, as well as reticular nucleus and parabrachial nucleus of pons. The anterograde labeling of PHA-L showed that regenerated fibers of upper neurons overcame glial scar and regrew into the distal part of spinal cord through the grafts. Some labeled fibers extended long enough to the caudal gray matter of the transected site. Conclusion The implantation of OECs transfected by BDNF gene may benefit the survival and regeneration of the injured axons, and accelerate the repair of the injured spinal cord in a more efficient way than that with OECs alone.