Molecular, anatomical and functional changes in the retinal ganglion cells after optic nerve crush in mice
Molecular, anatomical and functional changes in the retinal ganglion cells after optic nerve crush in mice
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DOI：
10.1007/s10633-014-9478-2
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发表时间：
2015-01
影响因子：
1.4
通讯作者：
Masayoshi Yukita;S. Machida;K. Nishiguchi;Satoru Tsuda;Yu Yokoyama;Masayuki Yasuda;K. Maruyama;T. Nakazawa
中科院分区：
文献类型：
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作者：
Masayoshi Yukita;S. Machida;K. Nishiguchi;Satoru Tsuda;Yu Yokoyama;Masayuki Yasuda;K. Maruyama;T. Nakazawa
目的利用啮齿动物视神经挤压伤（ONC）及随后的轴突损伤来研究视网膜神经节细胞（RGC）变性的机制。在这里，我们检查了ONC后小鼠的视网膜电图（ERG），以研究正暗视阈值反应（pSTR）的变化。然后，我们比较这些变化与分子和形态学的变化，以确定早期的客观生物标志物RGC dysfunction.MethodsFifty 12周龄的C57 BL/6小鼠。ONC用于在每只动物的右眼中诱导轴突损伤，左眼用作对照。采用实时荧光定量PCR方法检测ONC后1、2、3、5、7天RGC标记Brn 3a和Brn 3b的表达。在ONC后第1、2、3、5、7和10天，在暗适应下记录ERG，刺激强度从-6.2增加到0.43 log cd-s/m2。测量pSTR、a波和b波振幅。结果Brn 3a和Brn 3b的表达分别在ONC后第1、2、5、7、10天开始明显下降（P <0. 01），第10天开始下降（P<0. 01），第20天下降（P<0. 01）。pSTR的振幅在第3天迅速显著恶化，之后逐渐下降（P< 0.01），而a和b波振幅在整个实验期间保持不变。视网膜内层厚度逐渐减少，以第10天减少最明显（P< 0.01）。结论pSTR的减少可能反映了ONC后RGC功能的早期丧失，RGC特异性基因表达的下降先于RGC的解剖和功能改变。
PurposeOptic nerve crush (ONC) and subsequent axonal damage can be used in rodents to study the mechanism of retinal ganglion cell (RGC) degeneration. Here, we examined electroretinograms (ERGs) in post-ONC mice to investigate changes in the positive scotopic threshold response (pSTR). We then compared these changes with molecular and morphological changes to identify early objective biomarkers of RGC dysfunction.MethodsFifty 12-week-old C57BL/6 mice were included. ONC was used to induce axonal injury in the right eye of each animal, with the left eye used as a control. The expression of the RGC markersBrn3aandBrn3bwas measured on days 1, 2, 3, 5 and 7 after ONC with quantitative real-time PCR. ERGs were recorded under dark adaptation with the stimulus intensity increasing from −6.2 to 0.43 log cd-s/m2on days 1, 2, 3, 5, 7 and 10 after ONC. The pSTR, a- and b-wave amplitudes were measured. Inner retinal thickness around the optic nerve head was measured with spectral-domain optical coherence tomography on days 0, 2, 5, 7 and 10 after ONC.ResultsThe expression ofBrn3aandBrn3bbegan to significantly decrease on day 1 and day 2, respectively (P< 0.01). The amplitude of the pSTR underwent rapid, significant deterioration on day 3, after which it fell gradually (P< 0.01), while the a- and b-wave amplitudes remained unchanged throughout the experiment. Inner retinal thickness gradually decreased, with the most significant reduction on day 10 (P< 0.01).ConclusionsDecrease in pSTR likely reflected the early loss of RGC function after ONC and that declining expression of RGC-specific genes preceded anatomical and functional changes in the RGCs.