Chidlow Glyn, Casson Robert, Sobrado-Calvo Paloma, Vidal-Sanz Manuel, Osborne Neville N
Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, UK.
Mol Vis. 2005 Jun 2;11:387-96.
In the current study, a non-histological approach, namely semi-quantitative RT-PCR, was used to provide information on retinal ganglion cell (RGC) injury and survival after optic nerve transection (ONT). The levels of mRNAs synthesized by RGCs and glial components were initially measured at defined time points after ONT. Subsequently, a comparison was made between the levels of these mRNAs in the ONT retinas of rats treated with the neuroprotectant BDNF and in rats which received vehicle.
Wistar rats received an ONT in one eye, while the fellow eye served as a control. ONT was performed 1-2 mm from the optic disc without damaging the retinal blood supply. In the first experiment, rats were killed at 1, 3, 5, 7, and 21 days after ONT. In the second experiment, brain derived neurotrophic factor (BDNF; 5 microg) or vehicle was injected intravitreally at the same time as the ONT and animals were killed after 7 days.
After ONT, mRNA levels of RGC markers (NF-L and Thy-1) decreased substantially, while levels of GFAP and certain trophic factors mRNAs increased significantly. Administration of BDNF resulted in a substantial, but not complete, preservation of the levels of the RGC specific mRNAs, while ONT induced increases in GFAP and trophic factor mRNAs were not reduced to any great extent by BDNF.
The present studies show that measurement of NF-L and Thy-1 mRNAs provides a sensitive and reliable index of RGC injury after ONT, while measurement of GFAP and trophic factors mRNAs provides more general information on the effect of the injury on the retina.
在本研究中，采用一种非组织学方法，即半定量逆转录聚合酶链反应（RT-PCR），来提供视神经横断（ONT）后视网膜神经节细胞（RGC）损伤和存活情况的信息。在ONT后的特定时间点，首先测量由RGC和神经胶质成分合成的mRNA水平。随后，比较了用神经保护剂脑源性神经营养因子（BDNF）治疗的大鼠ONT视网膜与接受赋形剂的大鼠ONT视网膜中这些mRNA的水平。
Wistar大鼠一只眼接受ONT，另一只眼作为对照。ONT在距视盘1-2mm处进行，不损伤视网膜血液供应。在第一个实验中，大鼠在ONT后1、3、5、7和21天处死。在第二个实验中，在ONT的同时经玻璃体注射脑源性神经营养因子（BDNF；5μg）或赋形剂，7天后处死动物。
ONT后，RGC标志物（NF-L和Thy-1）的mRNA水平大幅下降，而胶质纤维酸性蛋白（GFAP）和某些营养因子mRNA水平显著升高。给予BDNF可使RGC特异性mRNA水平得到显著但不完全的保留，而ONT诱导的GFAP和营养因子mRNA水平升高并未被BDNF大幅降低。
本研究表明，测量NF-L和Thy-1 mRNA可提供ONT后RGC损伤的敏感且可靠指标，而测量GFAP和营养因子mRNA可提供关于损伤对视网膜影响的更全面信息。
