Purpose

To develop a model of focal injury by blue light-emitting diode (LED)-induced phototoxicity (LIP) in pigmented mouse retinas and to study the effects on cone, Iba-1⁺ cells and retinal pigment epithelium (RPE) cell populations after administration of basic fibroblast growth factor (bFGF) and minocycline, alone or combined.

Methods

In anesthetized dark-adapted adult female pigmented C57BL/6 mice, left pupils were dilated and the eye exposed to LIP (500 lux, 45 s). The retina was monitored longitudinally in vivo with SD-OCT for 7 days (d). Ex vivo, the effects of LIP and its protection with bFGF (0.5 μg) administered alone or combined with minocycline (45 mg/kg) were studied in immunolabeled arrestin-cone outer segments (a⁺OS) and quantified within a predetermined fixed-size circular area (PCA) centered on the lesion in flattened retinas at 1, 3, 5 or 7d. Moreover, Iba-1⁺ cells and RPE cell morphology were analysed with Iba-1 and ZO-1 antibodies, respectively.

Results

LIP caused a focal lesion within the superior-temporal retina with retinal thinning, particularly the outer retinal layers (116.5 ± 2.9 μm to 36.8 ± 6.3 μm at 7d), and with progressive diminution of a⁺OS within the PCA reaching minimum values at 7d (6218 ± 342 to 3966 ± 311). Administration of bFGF alone (4519 ± 320) or in combination with minocycline (4882 ± 446) had a significant effect on a⁺OS survival at 7d and Iba-1⁺ cell activation was attenuated in the groups treated with minocycline. In parallel, the RPE cell integrity was progressively altered after LIP and administration of neuroprotective components had no restorative effect at 7d.

Conclusions

LIP resulted in progressive outer retinal damage affecting the OS cone population and RPE. Administration of bFGF increased a⁺OS survival but did not prevent RPE deterioration.

中文翻译：

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成年色素小鼠中局灶性发光二极管诱导的锥形光感受器光毒性的体内模型：bFGF 的保护

目的

开发蓝色发光二极管 (LED) 诱导的小鼠色素视网膜光毒性 (LIP) 局灶性损伤模型，并研究给药后对视锥细胞、Iba-1 ⁺细胞和视网膜色素上皮 (RPE) 细胞群的影响碱性成纤维细胞生长因子 (bFGF) 和米诺环素，单独或联合使用。

方法

在麻醉的暗适应成年雌性 C57BL/6 小鼠中，左瞳孔扩大，眼睛暴露于 LIP（500 勒克斯，45 秒）。用 SD-OCT在体内纵向监测视网膜7 天（d）。离体，在免疫标记的抑制蛋白锥体外段 (a ⁺ OS)中研究了 LIP 的作用及其使用 bFGF (0.5 μg) 单独给药或与米诺环素 (45 mg/kg) 联合给药的保护作用，并在预定的固定大小内进行量化在第 1、3、5 或 7 天，以扁平视网膜病变为中心的圆形区域 (PCA)。此外，分别用 Iba-1 和 ZO-1 抗体分析了Iba-1 ⁺细胞和 RPE 细胞形态。

结果

LIP 在颞上视网膜内引起局灶性病变，视网膜变薄，尤其是视网膜外层（第 7 天从 116.5 ± 2.9 μm 到 36.8 ± 6.3 μm），并且PCA 内的a ⁺ OS逐渐减小，在 7d 时达到最小值（6218 ± 342 至 3966 ± 311）。单独施用 bFGF (4519 ± 320) 或联合米诺环素 (4882 ± 446) 对第 7 天的 a ⁺ OS 存活率有显着影响，并且在用米诺环素治疗的组中，Iba-1 ⁺细胞活化减弱。同时，LIP 后 RPE 细胞完整性逐渐改变，神经保护成分的给药在第 7 天没有恢复作用。

结论

LIP 导致渐进性外层视网膜损伤，影响 OS 视锥细胞群和 RPE。bFGF 的施用增加了 a ⁺ OS 存活率，但不能防止 RPE 恶化。