Hypoxia-driven histone modification landscape and the role of EZH2 in retinal neovascularization

IF 2.7 2区医学 Q1 OPHTHALMOLOGY

Experimental eye research Pub Date : 2025-09-26 DOI:10.1016/j.exer.2025.110670

Yong Lin, Rusen Yang, Tianyi Xu, Juxiu Ye, Hua Zhang, Peter S. Reinach, Jia Qu, Dongsheng Yan

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引用次数: 0

Abstract

Enhancer of zeste homolog 2 (EZH2) is a critical histone methyltransferase involved in catalyzing H3K27 trimethylation, regulating cell fate determination, DNA damage repair, cell proliferation, and differentiation. However, its role in retinal neovascularization (RNV) remains unclear. Here, we investigated the effects of EZH2-mediated H3K27me3 in human retinal microvascular endothelial cells (HRMECs) under hypoxic conditions. Hypoxia significantly upregulated various histone modifications in HRMECs, with the most pronounced increase in H3K27me3. Immunofluorescence confirmed increased EZH2 expression in the neo-vessels of the oxygen-induced retinopathy (OIR) model and hypoxia-treated HRMECs. Inhibition of EZH2, through specific inhibitors or siRNA, effectively reduced EZH2 and H3K27me3 levels, leading to decreased HRMEC proliferation, migration, and angiogenesis. Chromatin immunoprecipitation assays indicated that EZH2-mediated H3K27me3 suppresses miR-221 expression. Overexpression of miR-221 reproduced the effects of EZH2 inhibition, and dual-luciferase reporter assays confirmed that miR-221 directly targets KDR. Inhibition of miR-221 counteracted the KDR downregulation caused by EZH2 inhibition. Furthermore, intravitreal administration of the EZH2 inhibitor DZNeP significantly reduced RNV in OIR mice. In conclusion, our findings identify the EZH2-miR-221-KDR axis as a critical regulatory pathway in RNV and suggest that EZH2 inhibition may represent a promising therapeutic strategy for RNV-related diseases.

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缺氧驱动的组蛋白修饰景观和EZH2在视网膜新生血管中的作用。

zeste同源物2增强子（Enhancer of zeste homolog 2, EZH2）是一种关键的组蛋白甲基转移酶，参与催化H3K27三甲基化、调节细胞命运决定、DNA损伤修复、细胞增殖和分化。然而，其在视网膜新生血管（RNV）中的作用尚不清楚。在这里，我们研究了缺氧条件下ezh2介导的H3K27me3对人视网膜微血管内皮细胞（HRMECs）的影响。缺氧显著上调hrmec中各种组蛋白修饰，其中H3K27me3的上调最为明显。免疫荧光证实EZH2在氧诱导视网膜病变（OIR）模型和缺氧处理的hrmec的新生血管中表达增加。通过特异性抑制剂或siRNA抑制EZH2，有效降低EZH2和H3K27me3水平，导致HRMEC增殖、迁移和血管生成减少。染色质免疫沉淀实验表明ezh2介导的H3K27me3抑制miR-221的表达。miR-221的过表达再现了EZH2抑制的作用，双荧光素酶报告基因检测证实了miR-221直接靶向KDR。miR-221的抑制抵消了EZH2抑制引起的KDR下调。此外，玻璃体内给予EZH2抑制剂DZNeP可显著降低OIR小鼠的RNV。总之，我们的研究结果确定EZH2- mir -221- kdr轴是RNV的一个关键调控途径，并表明EZH2抑制可能是一种有希望的RNV相关疾病的治疗策略。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Experimental eye research 医学-眼科学

CiteScore

6.80

自引率

5.90%

发文量

323

审稿时长

66 days

期刊介绍： The primary goal of Experimental Eye Research is to publish original research papers on all aspects of experimental biology of the eye and ocular tissues that seek to define the mechanisms of normal function and/or disease. Studies of ocular tissues that encompass the disciplines of cell biology, developmental biology, genetics, molecular biology, physiology, biochemistry, biophysics, immunology or microbiology are most welcomed. Manuscripts that are purely clinical or in a surgical area of ophthalmology are not appropriate for submission to Experimental Eye Research and if received will be returned without review.