Liu Chaoqi, Sun Zhe, Cao Lining, Wang Fang
Department of Ophthalmology, Tenth People's Hospital of Tongji University, Shanghai 200072, China.
Department of Ophthalmology, Tenth People's Hospital of Tongji University, Shanghai 200072, China; Email:
Zhonghua Yan Ke Za Zhi. 2015 Nov;51(11):831-8.
To investigate the alterations of retinal tissue induced by OAβ(1-42) subretinal injection in normal C57BL/6N mice.
Experimental study. One hundred and twenty C57BL/6N mice aged 8 weeks participated in this study. Among them, 60 eyes received subretinal injection of OAβ(1-42); another 60 received double distilled water as control. The concentration of OAβ(1-42) was 0.312 5 mmol/L. We took fundus photograph and autofluorescence, electroretinogram(ERG), haematoxylineosin staining of retinal paraffin sections, β-galactosidase staining of neural retinal flatmounts, immunofluorescence of senescence marker P16INK4a of RPE/choroidal flatmounts, Western blot and RT-PCR of senescence relative cytokines IL-6, TGF-β1 before and after the injection. The data were analyzed by independent sample t-test.
Comparing with controls, 1 week post injection, the experimental group eyes had atrophied area with high autofluorescence site, and showed evident decrease in amplitudes of a wave (39.94±7.75)µV comparing with the controls (225.27±28.94)µV(t=12.45, P<0.001) in scotopia ERG, so did the amplitude of b wave (185.55±4.62)µV comparing with the controls (873.78±43.80)µV(t=27.06, P<0.001), retinal structures appeared significant loss of retinal thickness (t=75.13, P<0.001) along with hypo- or hyperpigmentation; the experimental eyes had high frequency of blue-green deposits in retinal β-gal staining; the green fluorescence sites of RPE/choroidal flatmounts were clear and bright, indicating higher expression of P16INK4a in the nucleus; these results were the same till 8 weeks post operation. Western blot and RT-PCR vertified conspicuous increases in expression of TGF-β1, IL-6 in retinas of experimental eyes compared with the control ones 1 week post injection.
OAβ(1-42) subretinal injection could induce visual function deficiency and retinal tissue senescence. All the manifestations were AMD-like retinopathy, which implied that Aβ(1-42) might be an essential clue in human AMD pathology.
研究在正常C57BL/6N小鼠中，经视网膜下注射淀粉样β蛋白1-42（OAβ(1-42)）诱导的视网膜组织改变。
实验研究。120只8周龄的C57BL/6N小鼠参与本研究。其中，60只眼接受视网膜下注射OAβ(1-42)；另外60只接受双蒸水作为对照。OAβ(1-42)的浓度为0.312 5 mmol/L。在注射前后，我们进行了眼底照相和自发荧光检查、视网膜电图（ERG）、视网膜石蜡切片苏木精-伊红染色、神经视网膜铺片β-半乳糖苷酶染色、视网膜色素上皮/脉络膜铺片衰老标志物P16INK4a免疫荧光检查、衰老相关细胞因子白细胞介素-6（IL-6）、转化生长因子-β1（TGF-β1）的蛋白质免疫印迹法（Western blot）和逆转录-聚合酶链反应（RT-PCR）。数据采用独立样本t检验进行分析。
与对照组相比，注射后1周，实验组眼出现萎缩区域伴高自发荧光部位，在暗视ERG中，a波振幅（39.94±7.75）µV较对照组（225.27±28.94）µV明显降低（t=12.45，P<0.001），b波振幅（185.55±4.6）µV较对照组（873.78±43.80）µV也明显降低（t=27.06，P<0.001），视网膜结构出现视网膜厚度显著变薄（t=75.13，P<0.001）并伴有色素减退或色素沉着；实验组眼在视网膜β-半乳糖苷酶染色中有高频蓝绿色沉积物；视网膜色素上皮/脉络膜铺片的绿色荧光部位清晰明亮，表明细胞核中P16INK4a表达较高；这些结果在术后8周时仍相同。蛋白质免疫印迹法和逆转录-聚合酶链反应证实，与对照组相比，注射后1周实验组眼中TGF-β1、IL-6的表达明显增加。
视网膜下注射OAβ(1-42)可诱导视觉功能缺陷和视网膜组织衰老。所有表现均为年龄相关性黄斑变性（AMD）样视网膜病变，这意味着β淀粉样蛋白1-42（Aβ(1-42)）可能是人类AMD病理学中的一个关键线索。
