Epigallocatechin gallate ameliorates retinal pigment epithelial cell damage via the CYFIP2 /AKT pathway.

Abstract

Age-related macular degeneration (AMD) is a representative age-related ophthalmic disease, and the pathogenesis of AMD remains unclear. This research intended to determine whether epigallocatechin gallate (EGCG) could alleviate the progression of AMD and the possible mechanism. We constructed three groups of mice (young, aged, and EGCG), and HE and TUNEL staining of retinal tissues was performed to observe the structural changes in the retinal pigment epithelial (RPE) layer and the level of apoptosis, respectively. Through RNA-Sequencing analysis of retinal tissues and by RT-qPCR, GO, KEGG, and literature analyses, we identified cytoplasmic fragile X mental retardation 1-interacting protein 2 (CYFIP2) as a possible effector gene for EGCG action and validated its role by immunofluorescent and western blotting experiments. The CCK-8 and Hoechst 33342 apoptosis assays, and western blotting and qRT-PCR assays showed that EGCG reduced hydrogen peroxide (H₂O₂)-induced apoptosis in adult human RPE (ARPE-19) cells, and the expression of Cyfip2 was changed accordingly. RNA interference analysis indicated that Cyfip2 knockdown alleviated H₂O₂-induced ARPE apoptosis, while its overexpression weakened EGCG's protective effect. Western blot analysis showed that Cyfip2 mediated the anti-apoptotic effect of EGCG by modulating the level of protein kinase B (Akt) phosphorylation in ARPE cells, and the activation level of phosphorylated AKT (p-AKT Ser473) in retinal tissue of the EGCG-fed group was higher than that of the aged group. Taken together, this study suggests that EGCG plays a protective role in the development of AMD and the apoptosis of ARPE cells through the Cyfip2/AKT pathway.