【摘要】 目的评价Nogo-A基因在视神经损伤后修复机制中的作用。方法Nogo-A基因敲除联合视神经损伤鼠为实验组(20只),C57BL/6小鼠联合视神经损伤作为对照组(20只)。制备视网膜、视神经冰冻切片,采用免疫荧光技术检测视网膜神经节细胞和视神经中生长相关蛋白(GAP)-43的表达。进行视网膜神经节细胞体外培养,进行GAP-43染色,采用图像分析系统计算细胞轴突长度。结果视神经中GAP-43表达:夹伤后1、3、7d对照组中表达少量GAP-43,实验组中GAP-43表达明显高于对照组(t=2·12,3·56、2·63,均P<0·01)。GAP-43抗体染色可见着色在体外培养RGC轴突,实验组3d有较长轴突生长,对照组3d有较短轴突生长。RGC于培养1、3及7d,经自动图像分析系统处理,得出细胞突起长度,实验组突起长度明显高于对照组(F=41·36、31·23,均P<0·01)。结论Nogo-A基因在抑制视神经损伤后轴突再生机制中起重要作用。更多还原

【Abstract】 Objective To investigate the role Nogo-A gene plays in the axonal regeneration of retinal ganglion cells (RGCs) after optic nerve crush. Methods Twenty Nogo-A knockout C57BL mice and 20 normal C57BL/6 mice underwent clipping at the optic nerve 2 mm behind the eyeball by specially designed clip so as to cause partial optic nerve injury. Then the mice in each group were subdivided into subgroups of day 1 (n=7), day 3 (n=7), and day 7 (n=6). The optical nerves of different groups were taken out to detect the mRNA expression of Nogo-A gene by in situ hybridization. Frozen sections of optical nerve were immunostained to investigate the expression of GAP-43, a protein showing axonal regeneration, by immunofluorescence assay. RGCs were cultured and immunostained with Thy1.1 antibody and GAP-43 antibody. The axonal growth of the RGCs was calculated with a computerized image analyzer. Results Nogo-A expression could be seen in the optical nerves of the control mice, however, not in the Nogo-A knockout mice. The expression levels of GAP-43 at different time points of the Nogo-A knockout mice were all significantly higher than those of the control mice(t=2.12,3.56,2.63,P<0.01). Staining of GAP-43 antibody could be seen in the axons of the cultured RGCs. The neurite growth of the Nogo-A knockout mice was significantly longer than that of the control mice at different time points(F=41.36、31.23,P<0.01). Conclusion Nogo-A gene plays an important role in inhibition of axonal regeneration of optic nerve after injury.更多还原