摘要目的 观察髓鞘相关抑制分子Nogo-A及其受体NgR mRNA和蛋白在慢性高跟压大鼠视网膜组织中的表达和动态变化.方法 实验研究.将实验用SD大鼠分为造模后3、7、14及28 d组,每组各16只大鼠.取16只正常SD大鼠作为对照组.仅灼烧大鼠右眼浅层巩膜静脉和颞侧角膜缘静脉,以制作慢性高眼压模型.造模成功的大鼠于各时间点取其视网膜,分别采用逆转录-聚合酶链反应法( RT-PCR)和免疫印迹法,检测正常对照组和各实验组Nogo-A及其受体NgR mRNA和蛋白相对表达水平(以目的基因条带与甘油醛-3-磷酸脱氢酶条带的A值比值作为目的基因Nogo-A mRNA的相对表达量,以日的蛋白条带与β-actin条带的A值比值作为目的蛋白Nogo-A mRNA的相对表达量).组间检测数据比较采用单因素方差分析.结果 64只实验大鼠中,有60只大鼠成功建立了慢性高眼压动物模型.造模成功大鼠在眼压升高后3、7、14及28 d,Nogo-A mRNA和蛋白表达水平持续升高,mRNA的A值比值分别为0.661±0.065、0.831±0.055、0.813±0.063及0.844±0.077,蛋白的A值比值分别为1.284±0.043、1.359±0.033、1.381±0.063及1.361 ±0.044;各时间点组间Nogo-A mRNA和蛋白相对表达水平差异有统计学意义(F=7.464,5.677;P ＜0.01).而组间Nogo-A受体NgR mRNA和蛋白相对表达水平差异无统计学意义(F=0.598,0.460;P＞0.01).结论 高眼压导致视神经损伤的神经再生过程中,Nogo-A起抑制神经轴突再生的作用,其受体NgR表达受多重复杂因素的影响,Nogo-A对神经轴突再生的抑制作用可能受其他受体介导.

abstractsObjective To investigate the expression of Nogo-A and its receptor NgR mRNA and protein in the retina of rats with chronic elevated intraocular pressure (IOP).Methods Experimental study.Rat chronic ocular hypertension (OHT) was induced by obstructing episcleral veins and temporal limber veins.The retiual tissues were collected at day 3,7,14 and 28 after the IOP elevated in rats.Each group includes 16 rats and one group served as normal control.Expression of Nogo-A and NgR mRNA was detected by reverse transcription polymerase chain reaction ( RT-PCR),while the protein levels of Nogo-A and NgR were expressed by the western blot in rat retinal tissues in different groups.Expression of Nogo-A,NgR mRNA and protein were analysed by one way analysis of variance ( ANOV ) and multiple comparison ANOV.Results IOP in rat OHT group was significantly increased after day 3 lasting for 28 day.Compared with control group,the level of Nogo-A mRNA and protein in rat chronic OHT groups were significantly (mRNA:F=7.464,protein:F=5.677;P＜0.01) increased at day7,14,and28 (mRNA:0.661 ±0.065vs 0.831 ± 0.055,0.813 ± 0.063,0.844 ± 0.077,protein:1.284 ± 0.043 vs 1.359 ± 0.033,1.381 ±0.063,1.361 ±0.044),respectively.There is a tendency of increase of Nogo-A mRNA expression at day 3 but did not reach statistical significance.However,the level of NgR in the retina in rats with the chronic OHT was not significantly ( mRNA:F =0.598,protein:F =0.460; P ＞ 0.01 ) changed compared with normal group.Conclusion The increased expression of Nogo-A in retina of rat OHT indicates that Nogo-A may play a primary role in obstructing regeneration of optic nerve,which is mediated by other receptors and elements ralher than NgR.