The contribution of ferroptosis to the epithelial-mesenchymal transition phenotype in models of age-related macular degeneration.

PURPOSE: Age-related macular degeneration (AMD) involves dysfunction of the retinal pigment epithelium (RPE), where cellular senescence and epithelial-mesenchymal transition (EMT) are key pathological features. The upstream mechanisms linking these processes are not fully understood. This study investigates the potential role of ferroptosis in contributing to senescence-associated EMT in RPE cells.

METHODS

We utilized an aging mouse model and two cellular models in ARPE-19 cells, induced by D-galactose (D-gal) and low-dose sodium iodate (SI), respectively. Ferroptosis, EMT, and oxidative stress markers were evaluated via immunofluorescence, flow cytometry, and Western blotting. The specific ferroptosis inhibitor Ferrostatin-1 was used to assess the involvement of ferroptosis.

RESULTS

Aged mouse RPE/choroid complexes and stressed ARPE-19 cells exhibited features of EMT along with increased ferroptosis hallmarks, including lipid peroxidation and iron accumulation. A downregulation of the xCT/GPX4 anti-ferroptotic axis was observed. Pretreatment with Fer-1 alleviated ferroptosis by reducing iron levels and lipid peroxidation, and restored xCT/GPX4 expression. Furthermore, Fer-1 attenuated the EMT phenotype, as evidenced by the restoration of epithelial markers and reduction of mesenchymal markers (Vimentin, α-SMA) in both D-gal and SI models.

CONCLUSION

Our findings suggest that ferroptosis may contribute to linking RPE senescence with EMT, potentially via oxidative stress pathways. The combined targeting of both senescence and ferroptosis could therefore represent a potential therapeutic strategy for addressing RPE dysfunction and AMD progression.