Release of Retinal Extracellular Vesicles in a Model of Retinitis Pigmentosa.

Extracellular vesicles (EVs) are membranous structures released by cells, including those of the retinal pigment epithelium (RPE) and photoreceptors. The cargo of EVs includes genetic material and proteins, making these vesicles essential in cell communication. Among the genetic materials, we find a large number of microRNAs (miRNAs), small chains of noncoding RNA. In the case of EVs from the retina, changes have also been observed in the number and cargo of EVs.Our group confirmed that damaged RPE cells in vitro release a greater number of EVs with a higher pro-angiogenic factor (VEGFR-1 and VEGFR-2) than control non-damaged cells, thus increasing neovascularization in endothelial cell cultures. This indicates that something similar could happen in patients suffering from some types of retinal degeneration that occur with angiogenesis, such as wet AMD or RD.Here, we investigated the role of EVs in photoreceptor degeneration, and we report for the first time on CD9 and CD81, closely related tetraspanins, in wild-type and rd1 retinae. Our study demonstrates the involvement of EVs in the process of inherited photoreceptor degeneration in a PDE6 mutation.