Nogo-A在晶状体损伤促进视神经损伤后再生中的作用的相关研究

发布时间：2018-04-27 07:07

本文选题：视神经损伤 + 晶状体损伤　；参考：《郑州大学》2012年硕士论文

【摘要】：视神经的损伤(optic nerve injury)在眼科的临床工作中很常见。视神经损伤后往往预后很差,据统计致盲率可达40%～50%。视神经损伤后的再生很难,因此,探讨视神经损伤后再生困难的机制以及寻找有效方法促进视神经再生是广大学者研究的焦点。传统观点提出,成年哺乳动物的中枢神经损伤后没有再生能力而只有再生反应,Aguage在实验中发现,将坐骨神经移植到视网膜,可明显提高神经节细胞(Retina ganglion cells, RGCs)的存活率,从而促进损伤后的视神经修复再生,这一实验证明视神经损伤后可再生。近年来的大量实验研究发现,损伤视神经的同时损伤晶状体,并成功观察到损伤后的晶状体形成外伤性白内障,可成功提高视网膜神经节细胞的存活机率,从而促进视神经的修复再生。Fischer[2]与Leon两个小组的研究工作表明其可能的机制与神经营养因子(NGF、 BDNF、CNTF等)、局部炎症、晶状体蛋白等有关。近年来,随着髓鞘相关抑制分子Nogo-A[3]、 MAG[4][5]、 OMGP[6]等相继被证实,晶状体损伤对视神经损伤后再生的促进作用的机制是否与这些神经生长抑制因子有关报道很少,本实验拟对此相关机制进行探讨。目的观察单纯视神经损伤及视神经损伤联合晶状体损伤后视神经中Nogo-AmRNA及Nogo-A的表达,探讨晶状体损伤促进视神经损伤后再生的机制方-法实验动物选取Wistar大鼠,共66只。随即分为三组：A组：正常对照组(6只);B组：单纯视神经损伤组(30只)；C组：视神经损伤联合晶状体损伤组(30只)。分别于7d、14d、21d处死大鼠2只(A组)、10只(B组)、10只(C组),光镜下观察视神经的病理变化,免疫组化染色检测Nogo-a表达情况,采用逆转录-聚合酶链反应(RT-PCR),半定量分析不同组视神经Nogo-A mRNA的表达结果 1.视神经的少突胶质细胞中Nogo-a的表达损伤后7天,正常视神经对照组中,Nogo-A染色阳性的少突胶质细胞单行排列,排列规则,阳性细胞数为：117.40±2.84,呈淡蓝色。术后第7天,单纯损伤组神经纤维排列不规则,少突胶质细胞排列紊乱,阳性细胞数为：136.80±3.94,呈深蓝色。视神经联合晶状体损伤组神经纤维排列不规则,少突胶质细胞排列错乱,阳性细胞数：130.40±2.48,呈深蓝色。3组中Nogo-A表达阳性细胞数进行两两比较,除视神经损伤联合晶状体损伤组与单纯损伤组间差异无统计学意义(P=-0.277)外,其余每两组之间的比较都有统计学意义。损伤后14天,阳性细胞计数在正常视神经组为：119.80±4.45,单纯视神经损伤组为：128.40±3.82,视神经损伤联合晶状体损伤组为：122.6±3.23。单纯损伤组与正常喂养组比较差异有统计学意义(P0.05)、联合损伤组与正常喂养组比较差异无统计学意义(P=0.632),单纯损伤组与联合损伤组之间差异无统计学意义(P=0.121)。损伤后21天,正常组阳性细胞数为：116.60±4.38,单纯视神经损伤组阳性细胞数为：130.40±2.48,视神经损伤联合晶状体损伤组为：104.40±6.78。三组之间每两组之间的比较差异均有统计学意义(P0.05)。 2.样本经PCR扩增、琼脂糖凝胶电泳后显示Nogo-A mRNA在单纯损伤组和联合损伤组均可检测到,且在术后7d、14d和21d, LabWorks软件分析显示Nogo-A mRNA的扩增表现出很稳定的表达水平。结论 1.正常视神经也可见Nogo-a和Nogo-A mRNA的表达,且三个时间点表达较稳定。 2.单纯视神经损伤组及联合损伤组后Nogo-A表的阳性细胞数明显增多。 3.晶体状损伤促进轴突再生的机制与Nogo-A有关,可能是晶状体损伤后阻碍了Nogo-A mRNA的转录过程或者影响了Nogo-A的稳定性。
[Abstract]:Optic nerve injury is very common in the clinical work of the ophthalmology. The prognosis is very poor after optic nerve injury. It is difficult to regenerate after 40% ~ 50%. optic nerve injury according to the statistical blinding rate. Therefore, it is a study to explore the mechanism of the difficulty of regeneration after optic nerve injury and to find an effective method to promote the optic nerve regeneration. The traditional point of view suggests that the central nerve injury of adult mammals has no regeneration ability but only regenerative response. In the experiment, Aguage found that the transplantation of the sciatic nerve to the retina could obviously improve the survival rate of the ganglion cells (Retina ganglion cells, RGCs), thus promoting the regeneration of the optic nerve after the injury. To verify the regeneration of the optic nerve injury.
In recent years, a large number of experimental studies have found that the damage of the optic nerve at the same time damage the lens, and the successful observation of the traumatic cataract after the injury, can successfully improve the survival probability of retinal ganglion cells, thus promoting the repair and regeneration of the optic nerve,.Fischer[2] and Leon, two groups of research work to show that the possible machine It is related to NGF (BDNF, CNTF, etc.), local inflammation, and lens protein. In recent years, with myelin related inhibitors, Nogo-A[3], MAG[4][5], and OMGP[6] have been confirmed, whether the mechanism of lens injury to promote the regeneration of optic nerve injury is not related to these nerve growth inhibitors. The experiment is to discuss the related mechanism.
objective
To observe the expression of Nogo-AmRNA and Nogo-A in optic nerve after optic nerve injury and optic nerve injury combined with lens injury, and to explore the mechanism of lens injury to promote the regeneration of optic nerve after injury.
Square method
The experimental animals selected a total of 66 Wistar rats, and then divided into three groups: group A: normal control group (6); group B: simple optic nerve injury group (30); group C: optic nerve injury combined with lens injury group (30). 2 rats were killed in 7d, 14d, 21d, 10 (B group), 10 (C group). The pathological changes of optic nerve were observed under the light microscope, immunologic changes were observed under the light microscope. Immunity was observed under the light microscope. Immunity was observed under the light microscope. Immunology was observed under the light microscope. Immunity was observed under the light microscope, immune to the pathological changes of the optic nerve under the light microscope to observe the immune pathological changes under the light scope, immunization under the light scope, immunity under the observation of the immune system The expression of Nogo-a was detected by histochemical staining, and the expression of Nogo-A mRNA in different groups was analyzed by reverse transcription polymerase chain reaction (RT-PCR).
Result
Expression of Nogo-a in the oligodendrocytes of 1. optic nerve
In the normal optic nerve control group 7 days after the injury, the Nogo-A positive oligodendrocytes were arranged in a single row and arranged regularly. The number of positive cells was 117.40 + 2.84, and the number of oligodendrocytes in simple injury group was irregular and the oligodendrocytes were arranged irregular, and the number of positive cells was 136.80 + 3.94, and the optic nerve was dark blue. The arrangement of nerve fibers in the combined lens injury group was irregular and the oligodendrocytes were arranged in disorder. The number of positive cells was 130.40 + 2.48. The number of Nogo-A positive cells in the group of deep blue.3 was compared, and the difference between the optic nerve injury combined with the lens injury group and the simple injury group was not statistically significant (P=-0.277), and the other two groups were in each group. There is statistical significance in the comparison.
14 days after injury, the number of positive cells in the normal optic nerve group was 119.80 + 4.45, and the only optic nerve injury group was 128.40 + 3.82. The optic nerve injury combined with the lens injury group was 122.6 + 3.23. simple injury group and the normal feeding group was statistically significant (P0.05). There was no statistical difference between the combined injury group and the normal feeding group. Significance (P=0.632), there was no significant difference between pure injury group and combined injury group (P=0.121).
21 days after injury, the number of positive cells in the normal group was 116.60 + 4.38, and the number of positive cells in the simple optic nerve injury group was 130.40 + 2.48, and the optic nerve injury combined with the lens injury group was statistically significant (P0.05) between the 104.40 + 6.78. three groups.
2. samples were amplified by PCR, and the agarose gel electrophoresis showed that Nogo-A mRNA could be detected in both simple injury group and joint injury group, and 7d, 14d and 21d after operation. LabWorks software analysis showed that the amplification of Nogo-A mRNA showed a stable expression level.
conclusion
1. the expression of Nogo-a and Nogo-A mRNA was also observed in normal optic nerve, and the expression was stable at three time points.
2. the number of Nogo-A positive cells in the optic nerve injury group and the combined injury group increased significantly.
The mechanism of 3. crystal injury promoting axon regeneration is related to Nogo-A, which may be hindering the transcriptional process of Nogo-A mRNA or affecting the stability of Nogo-A after lens injury.

【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R774.6

【参考文献】