RPE PFKFB3 in Subretinal Fibrosis

PROJECT SUMMARY (See instructions): Subretinal fibrosis, an end-stage fibrous plaque/disciform scar that progresses from choroidal neovascularization (CNV) of neovascular age-related macular degeneration (nAMD), compromises highly organized anatomical layers and tightly coordinated cellular interactions, inevitably leading to irreversible visual impairment. Current treatment for subretinal fibrosis is limited; thus, therapeutic strategies for the inhibition of subretinal fibrosis are essential. The objective of this R00 proposal is to elucidate the metabolic mechanisms driving subretinal fibrosis, focusing on the role of glycolytic enzyme PFKFB3 in RPE cells. My central hypothesis is that PFKFB3-mediated glycolysis in RPE cells promotes epithelial-to-mesenchymal transition (EMT) and enhances production of proinflammatory and profibrotic mediators via stabilization of hypoxia-inducible factors (H IFs), ultimately leading to subretinal fibrosis. During the K99 phase, I demonstrated that PFKFB3 regulates glycolytic metabolism, HIF stabilization, and mesenchymal transition in RPE cells, and that PFKFB3-overexpressing RPE cells promote macrophage-tomyofibroblast (M MT) and endothelial-to-mesenchymal transitions (End MT) in neighboring cell types. In the R00 phase, I will test whether RPE-specific deletion of Pfkfb3 mitigates subretinal fibrosis and preserves visual function in two in vivo models: laser-induced choroidal neovascularization and spontaneous fibrosis in Vldlr / mice. I will utilize RPE-specific Pfkfb3 knockout mice, retinal lineage tracing, and functional readouts including ERG and OCT to evaluate fibrosis progression, myofibroblast abundance, and vision outcomes. This project is innovative because it links metabolic reprogramming with fibrotic remodeling in the retina, uncovering PFKFB3 as a central driver of fibrosis in RPE cells. It also proposes therapeutic targeting of metabolism as a novel antifibrotic strategy in AM D. The R00 phase will be conducted in the Department of Pharmacological Sciences at Stony Brook University. My K99 training under the mentorship of Ors. Yuqing Hua and Ruth Caldwell, with additional input from Ors. David Stepp, Jian-xing Ma, and Akrit Sodhi have prepared me to transition into an independent research career. The supportive research environment and resources at Stony Brook University are ideal for advancing my program focused on metabolic mechanisms and therapeutic targets in retinal fibrosis and degeneration.