Department of Ophthalmology and Clinical Centre of Optometry, Peking University People's Hospital, Beijing, China.
Eye Diseases and Optometry Institute, Peking University People's Hospital, Beijing, China.
Biomed Res Int. 2020 Oct 10;2020:7161027. doi: 10.1155/2020/7161027. eCollection 2020.
Retinal neovascularization (RNV) is an important pathological feature of vitreoretinopathy that can lead to severe vision loss. The purpose of this study was to identify the role of ephrin-A5 (Efna5) in RNV and to explore its mechanism. The expression pattern and biological significance of Efna5 were investigated in a mouse model of oxygen-induced retinopathy (OIR). The expression of Efna5 and downstream signaling pathway members was determined by RT-PCR, immunofluorescence, immunohistochemistry, and western blot analyses. shRNA was used to knockdown Efna5 in the retina of the OIR mouse model. Retinal flat mounts were performed to evaluate the impact of Efna5 silencing on the RNV process. We found that the Efna5 was greatly upregulated in the retina of OIR mice. Elevated Efna5 mainly colocalized with the retinal vessels and endothelial cells. We then showed that knockdown of Efna5 in OIR mouse retinas using lentivirus-mediated shRNA markedly decreased the expression of Efna5 and reduced the retinal neovascularization and avascular retina area. We further showed hypoxia stimulation dramatically increased both total and phosphorylation levels of ERK1/2 and the phosphorylation levels of Akt in OIR mice. More importantly, knockdown of Efna5 could inhibit the p-Akt and p-ERK signaling pathways. Our results suggested that Efna5 may regulate the RNV. This study suggests that Efna5 was significantly upregulated in the retina of OIR mice and closely involved in the pathological retinal angiogenesis.
视网膜新生血管（RNV）是玻璃体视网膜病变的重要病理特征，可导致严重的视力丧失。本研究旨在探讨 Ephrin-A5（Efna5）在 RNV 中的作用及其机制。在氧诱导的视网膜病变（OIR）小鼠模型中研究了 Efna5 的表达模式和生物学意义。通过 RT-PCR、免疫荧光、免疫组织化学和 Western blot 分析测定 Efna5 及其下游信号通路成员的表达。使用 shRNA 在 OIR 小鼠模型的视网膜中敲低 Efna5。进行视网膜平片评估 Efna5 沉默对 RNV 过程的影响。结果发现，OIR 小鼠视网膜中 Efna5 表达显著上调。升高的 Efna5 主要与视网膜血管和内皮细胞共定位。然后我们表明，用慢病毒介导的 shRNA 在 OIR 小鼠视网膜中敲低 Efna5 可显著降低 Efna5 的表达并减少视网膜新生血管形成和无血管视网膜面积。我们进一步表明，缺氧刺激可显著增加 OIR 小鼠中 ERK1/2 的总水平和磷酸化水平以及 Akt 的磷酸化水平。更重要的是，敲低 Efna5 可抑制 p-Akt 和 p-ERK 信号通路。我们的结果表明 Efna5 可能调节 RNV。本研究表明，Efna5 在 OIR 小鼠的视网膜中显著上调，并密切参与病理性视网膜血管生成。
