NF—kB配体受体激动因子在脊髓损伤后骨髓间充质干细胞移植中的作用

Effect of RANKL on intraspinal transplantation of bone marrow mesenchymal stem cells after spinal cord injury in rats

目的探讨NF—kB配体受体激动因子（receptor activator of NF—kappa B ligand，RANKL）在脊髓损伤后人骨髓间充质干细胞（hBMSCs）移植中对神经功能恢复的影响。方法Wistar大鼠60只，体重250—350g，雌雄不限，随机分为3组：（1）hBMSCs组，脊髓半横切后行hBMSCs移植；（2）RANKL＋hBMSCs组，脊髓半横切后hBMSCs和RANKL协同移植；（3）PBS组，脊髓半横切，移植物以PBS代替。移植后1，7，14，21，28d采用行为学指标观察大鼠神经功能恢复情况，应用免疫组化和免疫荧光技术检测移植的BrdU标记hBMSCs在宿主脊髓内胶质纤维酸性蛋白（GFAP）和神经元特异性核蛋白（NeuN）的表达情况。结果大鼠脊髓半横切损伤后，hBMSCs组和RANKL＋hBMSCs组均较PBS对照组有明显的神经功能恢复；而移植7，14d时，RANKL＋hBMSCs组动物较hBMSCs组神经功能恢复明显。RANKL＋hBMSCs组中hBMSCs—Ne—uN和hBMSCs—GFAP双标阳性率高于hBMSCs组。结论RANKL和hBMSCs协同移植可提高脊髓损伤后神经病学预后，提高hBMSCs在宿主体内向神经细胞的分化。

Objective To observe the effect of receptor activator of NF kappa B ligand （RANKL） on intraspinal transplantation of bone marrow mesenchymal stem cells （hBMSCs） after spinal cord injury in adult rats. Methods Sixty aduh Wistar rats, weighing 250 - 350g, were used for the experiment. They were subjected to left spinal cord hemisection, then divided into three groups ： （ 1 ） hBM- SCs group, BrdU-labeled hMSCs were injected adjacent to the injury area; （2） RANKL ＋ hBMSCs group, BrdU - labeled hMSCs with RANKL were injected adjacently to the injury area; （3） PBS group, phosphate-buffered saline （PBS） was injected adjacently to the injury area. Functional outcome measurements using the modified Tarlov score were performed at 1,7, 14, 21 and 28 days after transplantation. After the animals were killed, spinal cord sections were examined using immunohistochemical and immunofluorescence staining methods to detect if BrdU - labeled adult hBMSCs express the astrocytic marker- GFAP （glial fibriliary acidic protein） and the neuron marker-NeuN （neuronal nuclei）, and compared between the three groups. Results A statistically significant improvement in neurological function in rats that underwent hBMSCs and hBMSCs plus RANKL transplantation was found at each time point, compared with PBS injection rats. Meanwhile, a better neurological functional outcome was found in group hBMSCs ＋ RANKL than in group hMSCs at 7 and 14 days. More BrdU-NeuN and BrdU-GFAP immunoreactive hBMSCs were determined in rats that underwent hBMSCs and RANKL transplantation than hBMSCs injection only. Conclusion Intraspinal hBMSCs transplantation along with RANKL improves neurological outcome after spinal cord injury, and facilitates hBMSCs differentiation into neural cells.