Nogo-A mRNA在视神经损伤后视网膜中的表达和分布

Expression of Nogo-A mRNA in retina of adult rat after optic nerve trauma

目的定位检测NogoAmRNA在成年大鼠正常视网膜和视神经损伤后视网膜中的表达和分布。方法将90只成年大鼠随机分为2组,右眼为对照组,左眼为实验组。实验组在眼球后2mm用视神经损伤夹夹持9s,根据处死时间不同分别于夹伤后1、3、7d取出大鼠眼球,沿其长轴制作视网膜冰冻切片。应用原位杂交方法检测视网膜中NogoAmRNA的表达和定位。将切片图像输入图像分析仪进行处理。结果视网膜中可见NogoAmRNA在不同细胞层中的表达:视网膜神经节细胞层、内颗粒层、外颗粒层中可见NogoAmRNA表达,其中以视网膜神经节细胞层为最多。夹伤组中1、3、7d组分别与对照组比较,阳性细胞染色面积差异有极显著统计学意义(t=3.82,4.21,4.07;P<0.01),A值差异有非常显著统计学意义(t=3.90,4.52,3.78;P<0.01)。结论NogoAmRNA在视神经损伤后视网膜中的表达明显增多,在抑制视神经损伤后轴突再生的机制中可能起重要作用。

Objective To investigate the expression and distribution of Nogo-A mRNA in retina of adult rat after optic nerve trauma. Methods Ninety rats were divided into two groups. Right eyes of them were control group. Left of rats were experimental group and were crushed with optic nerve crush forcep for 9 seconds 2 mm behind the eyeball. Experimental group was divided into three subgroups according to sacrificing time. Eyeball of rats were nucleated at 1,3,7 days separately and the frozen sections of retina were longitudely cut. Expression and distribution of Nogo-A mRNA in retina of ninety healthy adult rat were detected with in situ hybridization. Sections of retina were randomly selected and photos were counted by a computerized image analyzer. Result The expression of Nogo-A mRNA could be seen in retinal ganglion cells layer,inner nuclear layer and outer nuclear layer. There was notable significance between experimental group of 1 day,3 days,7 days and control group of area of positively stained cells（ t = 3.82,4. 21.4.07 ; P 〈 0. 01 ） , so was density of positively stained cells （ t = 3.90,4.52,3.78 ; P 〈 0. 01 ）. Conclusion Nogo-A in retina is increased after the trauma of optic nerve in comparison with normal rat. It may be of important effect in the mechanism of inhibiting the axon regeneration after the trauma of optic nerve.