Shinoda K, Nakamura Y, Matsushita K, Shimoda K, Okita H, Fukuma M, Yamada T, Ohde H, Oguchi Y, Hata J, Umezawa A
Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
Br J Ophthalmol. 2001 Oct;85(10):1237-43. doi: 10.1136/bjo.85.10.1237.
BACKGROUND/AIM: EAT/mcl-1 (EAT), an immediate early gene, functions in a similar way to bcl-2 in neutralising Bax mediated cytotoxicity, suggesting that EAT is a blocker of cell death. The aim of this study was to determine the effect of overexpression of the human EAT gene on light induced retinal cell apoptosis.
EAT transgenic mice incorporating the EF-1alpha promoter were utilised, and expression of human EAT was detected by RT-PCR. Light damage was induced by raising mice under constant illumination. Two groups of animals, EAT transgenic mice (n=14) and littermates (n=13), were examined by ERG testing and histopathology at regular time points up to 20 weeks of constant light stimulation. Electrophysiological and histopathological findings were evaluated by established systems of arbitrary scoring as scores 0-2 and scores 0-3, respectively.
The mean score (SD) of ERG response was significantly lower in EAT transgenic mice (0.79 (0.89)) than in littermates (1.69 (0.48)) (p<0.01). Although the differences between the two survival curves did not reach statistical significance (p=0.1156), the estimated incidence of electrophysiological retinal damage was higher in EAT mice (0.0495/mouse/week; 95% confidence interval (CI) 0.0347-0.0500) than in littermates (0. 0199/mouse/week; 95% CI 0.0035-0.0364). The mean scores (SD) for histopathological retinal degeneration were 2.31 (0.63) in littermates and 1.43 (1.22) in EAT transgenic mice (p=0.065). However, Kaplan-Meier curves for histopathological failure in two groups of mice showed that retinal photoreceptor cells were preserved significantly against constant light in the littermate compared with transgenic mice (p=0.0241). The estimated incidence of histopathological retinal damage was 0.0042/mouse/week in the littermates (95% CI 0-0.0120) and 0.0419/mouse/week in the EAT mice (95% CI 0.0286-0.0500).
Retinal photoreceptor cell apoptosis under constant light stimulation is likely to be accelerated in transgenic retina overexpressing EAT.
背景/目的：EAT/mcl-1（EAT）是一种即刻早期基因，在中和Bax介导的细胞毒性方面，其功能与bcl-2相似，这表明EAT是细胞死亡的阻滞剂。本研究的目的是确定人类EAT基因过表达对光诱导的视网膜细胞凋亡的影响。
使用整合了EF-1α启动子的EAT转基因小鼠，并通过RT-PCR检测人类EAT的表达。通过在持续光照下饲养小鼠来诱导光损伤。在长达20周的持续光刺激的定期时间点，通过ERG测试和组织病理学检查两组动物，即EAT转基因小鼠（n = 14）和同窝小鼠（n = 13）。电生理和组织病理学结果分别通过既定的任意评分系统进行评估，评分为0 - 2分和0 - 3分。
EAT转基因小鼠的ERG反应平均评分（标准差）（0.79（0.89））显著低于同窝小鼠（1.69（0.48））（p < 0.01）。虽然两条生存曲线之间的差异未达到统计学显著性（p = 0.1156），但EAT小鼠中视网膜电生理损伤的估计发生率（0.0495/小鼠/周；95%置信区间（CI）0.0347 - 0.0500）高于同窝小鼠（0.0199/小鼠/周；95%CI 0.0035 - 0.0364）。同窝小鼠视网膜组织病理学退变的平均评分（标准差）为2.31（0.63），EAT转基因小鼠为1.43（1.22）（p = 0.065）。然而，两组小鼠组织病理学失败的Kaplan-Meier曲线显示，与转基因小鼠相比，同窝小鼠的视网膜光感受器细胞在持续光照下得到了显著保护（p = 0.0241）。同窝小鼠视网膜组织病理学损伤的估计发生率为0.0042/小鼠/周（95%CI 0 - 0.0120），EAT小鼠为0.0419/小鼠/周（95%CI 0.0286 - 0.0500）。
在持续光刺激下，过表达EAT的转基因视网膜中，视网膜光感受器细胞凋亡可能会加速。
