Establishment and Comparison of AMD-Relevant Fibrotic, Hypoxic, and Oxidative Stress Models in Human Retinal Pigment Epithelial Cells

Age-related macular degeneration (AMD) is a multifactorial retinal disease in which retinal pigment epithelium (RPE) dysfunction is associated with oxidative stress, hypoxia, and fibrotic remodelling. Molecular pathways underlying RPE responses to these AMD-related stresses remain incompletely understood. This study compared the proteomic responses of human primary retinal pigment epithelial (huRPE) cells to transforming growth factor-β2 (TGF-β2), cobalt chloride (CoCl2), and sodium iodate (NaIO3), which predominantly promote fibrotic, hypoxic, and oxidative stresses, respectively. We then performed Gene Ontology (GO) and Ingenuity Pathway Analysis (IPA) to characterise differentially abundant proteins (DAPs) and their associated functional pathways. Each stressor produced a distinct proteomic profile. TGF-β2 predominantly affected extracellular matrix (ECM) remodelling and profibrotic processes, CoCl2 altered hypoxia-associated and metabolic processes, and NaIO3 affected oxidative stress-related responses. We further compared DAPs identified across the three stress models with proteins previously reported to be altered in AMD RPE by Shen et al. Notably, hexokinase 2 (HK2), an AMD-associated altered protein, showed consistently increased abundance under all three stress conditions. This convergence highlights HK2 and its associated metabolic regulation contributing to the multi-pathogenesis of AMD.