Targeting H3K27me3 methyltransferase EZH2 restrains ANGPT2 signaling in choroidal neovascularization

Aberrant histone-modifying activity drives pathological angiogenesis, yet the epigenetic regulators that govern choroidal neovascularization (CNV) remain poorly defined. Here we demonstrate that the histone methyltransferase enhancer of zeste homolog 2 (EZH2) and its catalytic product H3K27me3 are markedly elevated in human and mouse CNV lesions. Vascular endothelial growth factor (VEGF) rapidly induced EZH2 expression in endothelial cells (ECs). Pharmacologic inhibition of EZH2 with 3-deazaneplanocin A (DZNep) suppressed VEGF-driven EC proliferation, migration, and tube formation in vitro and reduced laser-induced CNV volume by 41.9% in vivo (P < 0.01). RNA-seq revealed that EZH2 inhibition down-regulates a transcriptional program enriched for mitotic cell-cycle genes, microtubule cytoskeleton organizers, and pro-angiogenic cytokines. Conversely, the flow-dependent transcription factor Krüppel-like factor 2 (KLF2) emerged as one of the most significantly up-regulated genes following EZH2 blockade. Chromatin immunoprecipitation confirmed loss of H3K27me3 at the KLF2 promoter, leading to derepression of KLF2 and subsequent suppression of angiopoietin-2 (ANGPT2), a key permissive factor for pathological angiogenesis. Rescue experiments showed that siRNA-mediated knockdown of KLF2 reversed the anti-angiogenic effects of DZNep, validating the EZH2-KLF2-ANGPT2 axis as a functionally critical pathway. Collectively, our findings identify EZH2 as an essential epigenetic driver of CNV and provide pre-clinical evidence that EZH2 inhibition constitutes a promising therapeutic strategy for neovascular ocular diseases.