神经营养素-3能够促进体外受损伤大鼠脊髓神经元的存活及其神经突起生长

Neurotrophin-3 can promote the survival and neurite growth of injured rat spinal cord neurons in vitro

目的探讨神经营养素-3(NT-3)对体外机械性损伤的大鼠脊髓神经元存活及其神经突起生长影响。方法将体外培养的大鼠脊髓神经元分为4组:正常组、对照组、20 ng/ml NT-3组和40 ng/ml NT-3组。培养4 d后,除正常组外,其余3组建立划痕损伤模型。在划痕损伤后,对照组不做处理,另外2组分别在培养液中加入20 ng/mlNT-3和40 ng/ml NT-3继续培养。直至培养第6 d,应用4%多聚甲醛固定4组细胞。固定后的细胞分别做转移酶介导的三磷酸脱氧鸟苷-生物素刻痕末端标记(TUNEL)、微管相关蛋白2(MAP2)和生长相关蛋白-43(GAP43)免疫荧光染色,检测划痕损伤的神经元凋亡及其神经突起生长情况。结果免疫荧光化学染色显示,与对照组相比,应用NT-3处理的2组可以显著降低划痕损伤后的脊髓神经元凋亡率,并促进其神经突起生长。尤其是40 ng/mlNT-3组的神经元凋亡率最低,其神经突起可穿过划痕损伤边界。结论 NT-3能够促进体外机械性损伤的大鼠脊髓神经元存活及其神经突起生长。

Objective To investigate the effect of neurotrophin?3(NT?3)on the survival and neurite growth of rat spinal cord neurons with mechanical injury in vitro.Methods Rat spinal cord neurons cultured in vitro were divided into four groups:the Normal group,the Control group,the 20 ng/ml NT?3 group and the 40 ng/ml NT?3 group.After the neurons were cultured for 4 d,scratch injury model was established in other 3 groups except the Normal group.After scratch injury,the neurons in the Control group was not treated and those in other two groups were respectively added with 20 ng/ml NT?3 and 40 ng/ml NT?3 to continue the culture.Culturing until day 6,the cells of 4 groups were fixed with 4%paraformaldehyde.To detect the apoptosis and neurite growth of scratched neurons,fixed cells were stained by transferase?mediated deoxyuridine triphosphate?biotin Nick end labeling(Tunel),microtubule associated protein 2(MAP2)and growth associated protein?43(GAP43)with immunofluorescence.Results Immunofluorescence staining showed that,after scratch injury,NT?3 treating the two groups significantly reduced the apoptosis rate of spinal cord neurons and promoted the neurite growth,compared with the Control group.Especially,in the 40 ng/ml NT?3 group,the rate of neuronal apoptosis was the lowest and the regrowing neurites can cross the boundary of scratch injury.Conclusion NT?3 can promote the survival and neurite growth of rat spinal cord neurons with mechanical injury in vitro.