Photo-Oxidative Blue-Light Stimulation in Retinal Pigment Epithelium Cells Promotes Exosome Secretion and Increases the Activity of the NLRP3 Inflammasome

ABSTRACTPurpose: Age-related macular degeneration (AMD) is a major cause of blindness in the elderly, and the activation of the NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome is involved in AMD pathogenesis. We investigated whether photooxidative blue-light stimulation in retinal pigment epithelium (RPE) cells promotes exosome secretion and modulates the activity of the NLRP3 inflammasome in vitro.Methods: Exosomes were isolated from ARPE-19 cultures stimulated or not with blue-light photostimulation (488 nm). Isolated exosomes were characterized by transmission electron microscope and Western blot analyses. The contents of the NLRP3 inflammasome (IL-1β, IL-18, and caspase-1 as markers of the inflammasome) in exosomes were analyzed by Western blotting. After culture, IL-1β, IL-18, and caspase-1 in RPE cells were analyzed by both immunofluorescence and Western blotting. RT-PCR and Western blotting were conducted to assess the contents of NLRP3 in RPE cells.Results: Exosomes exhibited ...