BPS2026 – Impact of ECM stiffness alterations on ferroptosis of RPE cells

Age-related macular degeneration (AMD) is a leading cause of blindness worldwide. During AMD progression, the microenvironment of retinal pigment epithelial (RPE) cells undergoes mechanical softening, and ferroptosis has been recognized as a critical contributor to AMD pathogenesis. However, how different substrate stiffness regulates RPE susceptibility to ferroptosis remains largely unexplored. In our study, we employed polyacrylamide (PA) hydrogels with different stiffness (1–100 kPa) as culture substrates and seeded ARPE-19 cells to simulate distinct mechanical microenvironments. Our results demonstrate that ARPE-19 cells cultured on softer substrates exhibited significantly reduced viability (64.23%) upon Erastin treatment—a ferroptosis inducer—indicating that a softer mechanical environment enhances susceptibility to ferroptosis. Mechanistically, low substrates stiffness reduces integrin/FAK-Rho/ROCK tension, disrupts ZO-1/F-actin and sequesters YAP/TAZ (with β-catenin redistribution), leading to fission-biased mitochondrial dynamics, mitochondrial membrane potential loss, intramitochondrial iron (Fe 2+ ) loading, and increased ferroptosis sensitivity in ARPE-19 cells. By linking substrate stiffness to cytoskeletal dynamics and mitochondrial iron regulation, we provide alternative insights into how the mechanical microenvironment contributes to ferroptosis and AMD pathogenesis.