YBX1 Modulated Corneal Neovascularization Induced by Alkali Burn via m5C-Dependent Regulation of the STAT3/HIF-1α/VEGFA Axis.

PURPOSE: Effective management of corneal neovascularization (CoNV) remains challenging, and the role of epitranscriptomic regulation, particularly N5-methylcytosine (m5C) modification, in this process remain incompletely defined. This study investigated the function and mechanism of the RNA-binding protein YBX1 in CoNV following alkali burn (AB).

METHODS: An AB-induced CoNV model was generated using C57BL/6 mice. In vitro, human umbilical vein endothelial cells (HUVECs) underwent hypoxia/reoxygenation (H/R). Multi-omics approaches including transcriptome sequencing, RNA immunoprecipitation sequencing, and m5C methylated RNA immunoprecipitation sequencing were used to identify YBX1 targets and their modification status. Functional assays assessed angiogenesis, apoptosis, and reactive oxygen species (ROS). The therapeutic potential of the YBX1 inhibitor Soyasaponin II (SII) was evaluated in vivo.

RESULTS: YBX1 was upregulated following AB and H/R. YBX1 knockdown suppressed HUVEC migration, tube formation, and ROS production, while promoting apoptosis; these effects were rescued by HIF-1α overexpression. Mechanistically, YBX1 activated the JAK1/STAT3 pathway and recognizes m5C-modified sequences on STAT3 and VEGFA mRNAs, enhancing their stability. In vivo, subconjunctival injection of SII attenuated CoNV, reduced inflammation, and modulated macrophage polarization.

CONCLUSIONS: Our study unveils a novel epitranscriptomic mechanism in which YBX1 drives CoNV by regulating the stability of m5C-modified STAT3 and VEGFA mRNAs, thereby activating the JAK1/STAT3/HIF-1α axis. Inhibition of YBX1 with SII effectively counteracts this pathway, highlighting YBX1 as an attractive candidate for intervention against sight-threatening CoNV.