骨髓基质细胞移植治疗脊髓全横断损伤超微结构观察

Transplantation of marrow stromal cells for the treatment of spinal cord injury:an ultrastructural observation

目的观察骨髓基质细胞(MSCs)移植治疗脊髓全横断损伤(SCI)超微结构,探讨内源性细胞与再生轴突关系。方法通过全骨髓法培养、纯化MSCs,SCI 9 d后移植MSCs,通过免疫荧光组化观察细胞移植后损伤区轴突再生情况,免疫荧光双标、免疫电镜观察再生轴突与内源性细胞关系。结果移植8 w后实验组脊髓损伤区可见大量神经微丝蛋白200(NF200)阳性纤维,对照组脊髓损伤区未见明显的NF200阳性纤维。免疫荧光双标结果显示损伤区NF200阳性纤维和2',3'-环核苷酸磷酸而酯酶(CNP)阳性细胞之间存在密切的空间关系,免疫电镜显示CNP阳性细胞通过伸长丝状伪足形成再生轴突支架,内源性施万细胞参与再生轴突髓鞘形成。结论 MSCs移植可促进损伤区轴突再生,宿主自身CNP阳性细胞和施万细胞参与损伤轴突的再生和髓鞘形成。

Objective To observe uhrastructural organization in transplantation of marrow stromal cells （MSCs） for the treatment of spinal cord injury （SCI） and to explore the relationship between host-derived cells and regenerating axons. Methods MSCs were isolated and purified from Wistar rats, and then were transplanted at 9 d after spinal cord injury. Regenerating axons were observed by immnnofluorescence. The relationship between host-derived cells and regenerating axons were detected by double immunofluoresce and immunoelectron microscopy. Results Robust axons were detected at SCI area in experimental group and similar fiber were barely observed in control group. Close spatial relationship between neurofilament protein 200 （NF200）-positive fibres and 2,3 ：cyclic nucleotide phosphodi-esterase （CNP）-positive cells were shown by double labeling immunofluorescence. Immunoelectron microscopy showed CNP-positive cells formed compartments with their long extending filopodia and Schwann cells promoted axonal remyefination. Conclusion Transplantation of MSCs enhances axonal regeneration, and host-derived CNP-positive cells and Schwann cells provide structural support to regenerating axons and promote their remyelination in spinal cord injury.