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.