RNA-sequencing expression profile and functional analysis of retinal pigment epithelium in atrophic age-related macular degeneration

The retinal pigment epithelium (RPE) is fundamental to sustaining retinal homeostasis. RPE abnormality leads to visual defects and blindness, including age-related macular degeneration (AMD). Although breakthroughs have been made in the treatment of neovascular AMD, effective intervention for atrophic AMD is largely absent. The adequate knowledge of RPE pathology is hindered by a lack of the patients' RPE datasets, especially at the single-cell resolution. In the current study, we delved into a large-scale single-cell resource of AMD donors, in which RPE cells were occupied in a substantial proportion. Bulk RNA-seq datasets of atrophic AMD were integrated to extract molecular characteristics of RPE in the pathogenesis of atrophic AMD. Both in vivo and in vitro models revealed that carboxypeptidase X, M14 family member 2 (CPXM2), was specifically expressed in the RPE cells of atrophic AMD, which might be induced by oxidative stress and involved in the epithelial-mesenchymal transition of RPE cells. Additionally, silencing of CPXM2 inhibited the mesenchymal phenotype of RPE cells in an oxidative stress cell model. Thus, our results demonstrated that CPXM2 played a crucial role in regulating atrophic AMD and might serve as a potential therapeutic target for atrophic AMD.