Age-Driven Lipid Remodeling Activates Lysosome-Mediated Plasma Membrane Repair

The abundance and stoichiometry of membrane lipid species vary across a cell's lifespan and metabolic state. In the retinal pigment epithelium (RPE), age-related alterations in lipid composition contribute to vision loss and diseases such as age-related macular degeneration (AMD), yet the molecular drivers of these changes remain unclear. Here, we show that age-dependent remodeling of the composition and biophysical properties of the plasma membrane compromises membrane integrity and function. Remarkably, rather than undergoing cell death, affected cells activate a lysosome-dependent plasma membrane repair program to preserve barrier integrity. While this adaptive response may protect RPE structure under metabolic stress, it also drives spatially polarized release of lysosomal contents that potentially can contribute to extracellular matrix remodeling and sub-RPE deposit formation during aging and AMD. Finally, we demonstrate that supplementation with the direct product of the aging-associated lipid elongase ELOVL2 alleviates these phenotypes, providing direct evidence for a critical role of ELOVL2-mediated PUFA elongation in healthy aging. Taken together, our results propose a model in which age-dependent decline in PUFA elongation disrupts the balance between membrane flexibility and stability, initiating a compensatory cycle of membrane stress and repair.