Zhongshan Ophthalmic Center and State Key Laboratory of Ophthalmology, Sun Yat-sen University, Guangzhou 510060, China.
Exp Eye Res. 2012 Aug;101:1-8. doi: 10.1016/j.exer.2012.05.003. Epub 2012 May 30.
Image degradation by loss of higher spatial frequencies causes form-deprivation myopia (FDM) in humans and animals, and cyclical illumination (flicker) at certain frequencies may prevent FDM. The molecular mechanisms underlying FDM and its prevention by flicker are poorly known. To understand them better, we have identified proteins that differ in amount in form-deprived (FD) mouse retinas, under steady versus flickering light. Male C57BL/6 mice (age 27-29 days) were randomly divided into three groups: Experimental - monocularly form-deprived, and kept under either normal room light ("FD-Only") or 20 Hz flickering light ("FD-Flicker"), throughout the 12-hour light phase; and Control ("Open-Control") - kept under normal illumination, without form deprivation. After two weeks of treatment, retinal proteins were extracted and separated by two-dimensional gel electrophoresis (2D-GE); proteins that differ in content in FD-only versus FD-flicker retinas were identified by mass spectroscopy ("MS"), and their identities were verified by western blotting. The contents of three identified proteins differed statistically in FD-only compared to FD-flicker retinas. These proteins were identified by MS as α-A-crystallin, crystallin β A2 and crystallin β A1. Quantitative western blotting showed that the relative amount of α-A-crystallin in FD-only retinas was significantly higher than that in FD-Flicker and control retinas. In conclusion, form deprivation induced significant increases in the amounts of crystallins in mouse retinas. These increases were significantly reduced by exposure to 20 Hz flicker. Since form deprivation is known to induce myopia development, and flicker to prevent it, our data suggest that FD- and flicker-responsive changes in the content of crystallin proteins may be involved causally or protectively in myopia development.
图像高频信息的损失会导致形觉剥夺性近视（form-deprivation myopia，FDM），而特定频率的周期性光照（闪烁光）可能会预防 FDM。导致 FDM 的分子机制及其预防机制尚不清楚。为了更好地理解这些机制，我们鉴定了在稳定光和闪烁光条件下，形态剥夺（form deprived，FD）小鼠视网膜中含量不同的蛋白。雄性 C57BL/6 小鼠（27-29 日龄）随机分为三组：实验 - 单眼形觉剥夺，在整个 12 小时光照周期中，仅接受正常室内光（“FD-Only”）或 20Hz 闪烁光（“FD-Flicker”）照射；对照组（“Open-Control”） - 仅在正常光照下，不进行形觉剥夺。治疗两周后，提取视网膜蛋白，通过二维凝胶电泳（2D-GE）分离；通过质谱（MS）鉴定 FD-Only 组和 FD-Flicker 组视网膜中含量不同的蛋白，并通过 Western blot 验证其身份。与 FD-Flicker 组相比，FD-Only 组中 3 种鉴定出的蛋白含量有统计学差异。通过 MS 鉴定，这些蛋白分别为α-A-晶体蛋白、晶体蛋白βA2 和晶体蛋白βA1。定量 Western blot 显示，在 FD-Only 组视网膜中，α-A-晶体蛋白的相对含量明显高于 FD-Flicker 组和对照组。总之，形态剥夺会导致小鼠视网膜中晶体蛋白含量显著增加，而 20Hz 闪烁光照射则显著减少了这种增加。由于已知形态剥夺会诱导近视发展，而闪烁光可以预防近视，因此我们的数据表明，形态剥夺和闪烁光响应的晶体蛋白含量变化可能与近视的发展有因果关系或具有保护作用。
