Extracellular vesicles confer disease phenotype in Y402H-retinal pigment epithelium cell model of age-related macular degeneration.

Age related macular degeneration (AMD) is a leading cause of legal blindness. Vision loss is caused by the retinal pigment epithelium (RPE) and photoreceptors loss and/or retinal and choroidal angiogenesis. Here we report enhanced polarised secretion of extracellular vesicles (EVs) in complement factor H (CFH) Y402H AMD patient specific RPE. As indicated by multi ‘omics analyses, AMD RPE EVs carry a repertoire of RNA, proteins and lipids that reflect disease changes in the RPE cells of origin and mediate pathological processes such as oxidative stress, cytoskeletal dysfunction and angiogenesis. We demonstrate that exposure of control RPE to AMD RPE EVs leads to the formation of numerous cytoplasmic stress vacuoles, cytoskeletal destabilization, and abnormalities in the morphology of the nucleus in the recipient cells. Treatment of laminated retinal organoids containing photoreceptor cells with apical AMD RPE EVs leads to disrupted neuroepithelium and appearance of enlarged cells immunopositive for cytoprotective alpha B crystallin. The presence of cells expressing alpha B crystallin and progenitor cells markers Pax6 or Vsx2 are consistent with the activation of regenerative pathways upon injury. These findings suggest that AMD RPE EVs act as signalling messengers in the outer retina and may be involved in disease progression. 4 AMD patient CFH Y402H carriers-derived samples (F180_A, F180_B, F181_A and F181_B) and 4 control individuals-derived samples (F018_A, F018_B, AD3_A and AD3_B). All samples in duplicates. A- apical, B-basal - RPE cell conditioned media fractions-derived extracellular vesicles.