Recent Advances in Understanding the Role of PEST Sequence-Containing Proteins in Retinal Neovascularization

Abstract: Recent studies have identified significant advancements in understanding the role of PEST sequence-containing proteins in retinal neovascularization. Retinal neovascularization, a critical pathological process, leads to severe visual impairment associated with conditions such as diabetic retinopathy, retinopathy of prematurity, and neovascular age-related macular degeneration. These conditions represent the leading causes of blindness worldwide. Although initially effective, current anti-VEGF treatments can lose efficacy over time and impose a burden due to frequent administrations, highlighting the need for novel therapeutic targets. PEST sequences, characterized by proline, glutamic acid, serine, and threonine enrichment, are structural motifs within proteins that target them for rapid degradation via the ubiquitin-proteasome pathway. Beyond influencing protein degradation, PEST sequences are crucial in regulating angiogenesis and inflammation, essential factors in retinal disease progression. This review focuses on the dual regulatory roles of PEST sequences in VEGFR-2 degradation and stabilization, crucial receptors in angiogenic signaling, as well as their involvement in essential signaling pathways including Notch and JAK/STAT. These findings suggest that PEST sequences could serve as promising new therapeutic targets to control pathological neovascularization and associated inflammatory responses, paving the way for more effective treatments in retinal diseases. Furthermore, advances in gene editing technologies and innovative drug delivery systems enhance the potential for the development of PEST sequence-targeted therapies, offering promising avenues for future clinical applications.