Browsing by Subject "Retinal neovascularization"

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    Ref‐1 redox activity regulates retinal neovascularization by modulating transcriptional activation of HIF‐1α
    (Wiley, 2025) Hartman, Gabriella D.; Muniyandi, Anbukkarasi; Sishtla, Kamakshi; Kpenu, Eyram K.; Miller, William P.; Kaplan, Bryan A.; Kim, Leo A.; Liu, Sheng; Wan, Jun; Qi, Xiaoping; Boulton, Michael E.; Kelley, Mark R.; Corson, Timothy W.; Ophthalmology, School of Medicine
    Retinal neovascularization impairs visual function and is a hallmark of several neovascular eye diseases, including retinopathy of prematurity (ROP) and proliferative diabetic retinopathy (PDR). Current treatments include intravitreal injections of anti-vascular endothelial growth factor (VEGF) biologics, but these therapeutics are often accompanied by high treatment burden and resistance to therapy. Prior studies indicate that APE1/Ref-1, a multifunctional protein with both endonuclease (APE1) and redox-mediated transcriptional regulatory activity (Ref-1), activates multiple pro-angiogenic and pro-inflammatory signaling pathways by chemically reducing key cysteine residues in transcription factors, thereby activating them. Here, we investigated the previously unexplored role of Ref-1 in retinal neovascularization. We demonstrate that Ref-1 is highly expressed in endothelial cells in human PDR and in the oxygen-induced retinopathy (OIR) mouse model of retinal neovascularization. Ref-1 is also highly expressed in microglia and astrocytes in OIR. A small molecule Ref-1 redox inhibitor, APX2009, decreased retinal neovascularization in OIR after systemic delivery. In vitro, hypoxic endothelial cells did not exhibit upregulation of Ref-1 but rather increased Ref-1 nuclear localization. APX2009 decreased hypoxic endothelial cell proliferation and HIF-1α transcriptional activation. Thus, Ref-1 redox activity may be a novel therapeutic target for the treatment of retinal neovascularization, making APX2009 a promising systemic therapeutic approach for the treatment of vascular retinopathies such as ROP and PDR.
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    Repurposing antimalarial aminoquinolines and related compounds for treatment of retinal neovascularization
    (PLOS, 2018-09-12) McAnally, Danielle; Siddiquee, Khandaker; Gomaa, Ahmed; Szabo, Andras; Vasile, Stefan; Maloney, Patrick R.; Divlianska, Daniela B.; Peddibhotla, Satyamaheshwar; Morfa, Camilo J.; Hershberger, Paul; Falter, Rebecca; Williamson, Robert; Terry, David B.; Farjo, Rafal; Pinkerton, Anthony B.; Qi, Xiaping; Quigley, Judith; Boulton, Michael E.; Grant, Maria B.; Smith, Layton H.; Ophthalmology, School of Medicine
    Neovascularization is the pathological driver of blinding eye diseases such as retinopathy of prematurity, proliferative diabetic retinopathy, and wet age-related macular degeneration. The loss of vision resulting from these diseases significantly impacts the productivity and quality of life of patients, and represents a substantial burden on the health care system. Current standard of care includes biologics that target vascular endothelial growth factor (VEGF), a key mediator of neovascularization. While anti-VGEF therapies have been successful, up to 30% of patients are non-responsive. Therefore, there is a need for new therapeutic targets, and small molecule inhibitors of angiogenesis to complement existing treatments. Apelin and its receptor have recently been shown to play a key role in both developmental and pathological angiogenesis in the eye. Through a cell-based high-throughput screen, we identified 4-aminoquinoline antimalarial drugs as potent selective antagonists of APJ. The prototypical 4-aminoquinoline, amodiaquine was found to be a selective, non-competitive APJ antagonist that inhibited apelin signaling in a concentration-dependent manner. Additionally, amodiaquine suppressed both apelin-and VGEF-induced endothelial tube formation. Intravitreal amodaiquine significantly reduced choroidal neovascularization (CNV) lesion volume in the laser-induced CNV mouse model, and showed no signs of ocular toxicity at the highest doses tested. This work firmly establishes APJ as a novel, chemically tractable therapeutic target for the treatment of ocular neovascularization, and that amodiaquine is a potential candidate for repurposing and further toxicological, and pharmacokinetic evaluation in the clinic.