Yang Yijie, Shen Jiawei, Li Yanting, Chen Xinzhu, Liu Gaoqin, Lu Peirong
Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou, China.
Department of Ophthalmology, Suzhou EENT Hospital, Suzhou, China.
Invest Ophthalmol Vis Sci. 2025 Apr 1;66(4):83. doi: 10.1167/iovs.66.4.83.
Subretinal fibrosis (SRF) represents a significant contributor to irreversible vision loss in patients with neovascular age-related macular degeneration (nAMD). This study aimed to elucidate the underlying mechanism of SRF and identify potential therapeutic targets.
The SRF model was established using a two-stage laser-induced protocol in C57BL/6J mice. RNA-seq analysis was conducted to identify differentially expressed genes (DEGs) at 10 days and 30 days post-second laser. Quantitative RT-PCR was used to validate the expression levels of selected DEGs including zinc-alpha-2-glycoprotein 1 (AZGP1). Recombinant AZGP1 (rAZGP1) was intravitreally administrated to investigate its effects on SRF. The ARPE-19 cells were used to demonstrate the role of AZGP1 in modulating epithelial-mesenchymal transition (EMT).
RNA-seq of RPE/choroid complex identified a total of 66 DEGs between samples collected at 10 days and 30 days post-second laser compared with controls (log2(fold change) ≥ 1, false discovery rate [FDR] < 0.05), with Azgp1 being one of the most significant downregulated genes. Intravitreal injection of rAZGP1 markedly reduced collagen I and CD31 positive areas in RPE/choroid flat-mounts. Co-localization of AZGP1 and RPE65 was observed in patients with nAMD (GSE135922) and SRF mouse models. Treatment with rAZGP1 resulted in significantly lower expressions of collagen I, α-SMA, and fibronectin in ARPE-19 cells after TGFβ1 induction. Both knockdown and overexpression studies demonstrated that AZGP1 regulated the PI3K/AKT signaling pathway within ARPE-19 cells.
The abnormal expression pattern of AZGP1 is critical for the development of SRF. Exogenous supplementation with AZGP1 may represent a promising strategy for ameliorating SRF by inhibiting EMT within RPE through the PI3K/AKT pathway.
视网膜下纤维化（SRF）是导致新生血管性年龄相关性黄斑变性（nAMD）患者不可逆视力丧失的重要因素。本研究旨在阐明SRF的潜在机制并确定潜在的治疗靶点。
采用两阶段激光诱导方案在C57BL/6J小鼠中建立SRF模型。进行RNA测序分析以鉴定第二次激光照射后10天和30天的差异表达基因（DEG）。定量逆转录PCR用于验证包括锌-α-2-糖蛋白1（AZGP1）在内的选定DEG的表达水平。玻璃体内注射重组AZGP1（rAZGP1）以研究其对SRF的影响。使用ARPE-19细胞来证明AZGP1在调节上皮-间质转化（EMT）中的作用。
与对照组相比，对RPE/脉络膜复合体进行RNA测序发现，第二次激光照射后10天和30天采集的样本之间共有66个DEG（log2（倍数变化）≥1，错误发现率[FDR]<0.05），其中Azgp1是下调最显著的基因之一。玻璃体内注射rAZGP1可显著减少RPE/脉络膜平铺片中I型胶原蛋白和CD31阳性区域。在nAMD患者（GSE135922）和SRF小鼠模型中观察到AZGP1与RPE65的共定位。用rAZGP1处理后，TGFβ1诱导的ARPE-19细胞中I型胶原蛋白、α-SMA和纤连蛋白的表达显著降低。敲低和过表达研究均表明，AZGP1调节ARPE-19细胞内的PI3K/AKT信号通路。
AZGP1的异常表达模式对SRF的发展至关重要。通过PI3K/AKT途径抑制RPE内的EMT，外源性补充AZGP1可能是改善SRF的一种有前景的策略。
