Corneal fibrosis and opacity are major causes of visual impairment and blindness, while the conventional treatment by corneal transplantation remains limited due to the global shortage of donor materials and the risk of immune-mediated graft rejection. In this study, we investigated DNA methyltransferase (DNMT) inhibition using the FDA-approved agent decitabine (DAC; 5-aza-2′-deoxycytidine) to suppress corneal fibrosis. DNMT3A is a predicted target of the anti-fibrotic microRNA miR-29a, which was previously linked to the scar-reducing effects of cornealstromal stem cell-derived extracellular vesicles (doi:10.1016/j.jare.2022.05.008). DNMT3A expression was upregulated in scarred mouse corneas. In donor-derived corneal stromal fibroblasts, DAC dose-dependently suppressed TGFβ1-induced αSMA expression and attenuated myofibroblast-associated morphological and functional changes, including collagen gel contraction, at concentrations up to 50 μM. RNA sequencing further showed that DAC reversed TGFβ1-driven extracellular matrix remodeling, including changes in SPOCK1 and CTHRC1 expression. These effects were supported in injured mouse corneas, where topical DAC treatment reduced SPOCK1 and CTHRC1 expression, decreased scar formation, and restored corneal thickness toward normal levels. Fibrosis- and inflammation-associated gene expression was also downregulated, with no apparent treatment-related toxicity. In conclusion, these findings demonstrate that DNMT inhibition suppresses corneal fibrosis and myofibroblast differentiation, supporting the repurposing of DAC as a pharmacological, donor-independent strategy for reducing corneal fibrosis and preserving corneal transparency.

Epigenetics regulates gene activity without altering the underlying DNA sequences. Numerous studies have highlighted the importance of epigenetics in diverse physiological processes, including cell growth, differentiation, and tissue development. Increasingly, epigenetic modifications are recognized for their involvement in various diseases, notably corneal disorders. Corneal fibrosis, a common consequence of ocular injury or infection, significantly contributes to visual impairment and blindness worldwide. Recent evidence indicates that epigenetic changes regulate key processes in corneal pathogenesis, such as inflammation, wound healing, extracellular matrix remodeling, fibrosis, and neovascularization. These findings underscore the potential of developing novel therapeutic strategies that specifically target epigenetic mechanisms to treat or mitigate corneal pathology. Nevertheless, bringing epigenetic therapies into clinical practice remains challenging given the complexity of epigenetic regulation. Future research leveraging multi-omics technologies and specific gene manipulation will be essential to elucidate the mechanisms underlying epigenetic regulation in corneal diseases and to identify specific therapeutic targets. Such advancements will drive the development of effective, clinically relevant treatments for corneal fibrosis and related disorders.