Abstract
Purpose :
Targeting senescence in the retinal pigment epithelium (RPE) has recently emerged as a promising therapeutic approach for age-related macular degeneration (AMD). However, the mechanisms underlying RPE senescence remain largely unknown. In this study, we sought to uncover these mechanisms by employing single-cell RNA sequencing (scRNA-seq). Our analysis focused on RPE cells from both young and aged mice, aiming to reveal the cellular processes involved in RPE senescence.
Methods :
We performed scRNA-seq on RPE cells from young and 24-month-old mice. In vitro experiments involved integrin knockout (KO) in ARPE-19 cells using shRNA, FAK inhibitor application, and softer substrate use. We evaluated these methods for their ability to induce RPE senescence, characterized by increased p21 or p16 markers and senescent-associated secretory phenotype (SASP) gene activation. We also investigated YAP inactivation in both in vitro and in vivo settings. The therapeutic efficacy of a YAP activator, TRULI, was assessed in vitro (ARPE-19 and iPSC-RPE) and in vivo, including NaIO3-induced and naturally aged mouse models.
Results :
scRNA-seq revealed impaired cell-matrix adhesion in aged mouse RPE cells. Inhibition of integrin signaling, either genetically or chemically, and softer substrate use induced RPE senescence. Notably, we discovered that impaired integrin signaling led to YAP inactivation in senescent RPE cells. Importantly, TRULI treatment reversed senescence phenotypes in vitro and in vivo and improved retinal function, as evidenced by ERG results in mouse models.
Conclusions :
Our findings suggest that integrin-mediated cell-matrix adhesion dysfunction is a key driver of RPE senescence, with YAP inactivation being a critical mechanistic link. TRULI's ability to reverse RPE senescence and enhance retinal function highlights its potential as a therapeutic agent for AMD and age-related RPE diseases.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.