Garcia-Rodrigo, J. F. | bioRxiv Science

bioRxiv2024

Topical Ophthalmic Administration of VIAN-c4551 Antiangiogenic Peptide for Diabetic Macular Edema: Preclinical Efficacy and Ocular Pharmacokinetics

VIAN-c4551 is a cyclic antiangiogenic peptide that stands as a potent and stable inhibitor of vascular endothelial cell growth factor (VEGF), the major vasopermeability and angiogenic factor in diabetic macular edema and diabetic retinopathy. Intravitreal injections of inhibitors of VEGF are a first-line therapy, but the invasiveness, risk, and low adherence of frequent intravitreal injections interfere with the needed long-term treatments and successful outcomes. Eye drops are non-invasive and favor compliance. Here, we evaluated the preclinical efficacy, permeability, and ocular pharmacokinetics of VIAN-c4551 delivered in eye drops. VIAN-c4551 demonstrated high potency (IC50 = 137 pM) to inhibit the permeability of human umbilical vein endothelial cell monolayers induced by VEGF. VIAN-c4551 eye drops potently (0.005% minimum effective dose) prevented the retinal vascular leakage induced by VEGF injected intravitreally for up to 24 hours and reversed the increase in retinal vascular permeability due to streptozotocin-induced diabetes in rats and mice. VIAN-c4551 exhibited high permeability across MDCK epithelium and, after a single topical ocular instillation in rabbits, reached the retina-choroid in micromolar concentrations several orders of magnitude above its IC50 (Cmax= 51 {micro}M at 6 hours) that lasted at least 24 hours. In conclusion, VIAN-c4551 eye drops reach the back of the eye at therapeutic concentrations, providing a potential, once-a-day, non-invasive intervention for preventing and reversing retinal vascular leakage in diabetic macular edema, diabetic retinopathy, and other vascular retinopathies and preserving sight.

pharmacology and toxicology↗

bioRxiv2023

The apoptotic, inflammatory, and fibrinolytic actions of vasoinhibin are in a motif different from its antiangiogenic HGR motif

Vasoinhibin is a proteolytic fragment of the hormone prolactin that inhibits blood vessel growth (angiogenesis) and permeability, stimulates the apoptosis and inflammation of endothelial cells and promotes fibrinolysis. The antiangiogenic and antivasopermeability properties of vasoinhibin were recently traced to the HGR motif located in residues 46 to 48, allowing the development of potent, orally active, HGR-containing vasoinhibin analogs for therapeutic use against angiogenesis-dependent diseases. However, whether the HGR motif is also responsible for the apoptotic, inflammatory, and fibrinolytic properties of vasoinhibin has not been addressed. Here, we report that HGR-containing analogs are devoid of these properties. Instead, the incubation of human umbilical vein endothelial cells with oligopeptides containing the sequence HNLSSEM, corresponding to residues 30 to 36 of vasoinhibin, induced apoptosis, the nuclear translocation of NF-{kappa}B, the expression of genes encoding leukocyte adhesion molecules (VCAM1 and ICAM1) and proinflammatory cytokines (IL1B, IL6, TNF), and the adhesion of peripheral blood leukocytes. Also, the intravenous or intra-articular injection of HNLSSEM-containing oligopeptides induced the expression of Vcam1, Icam1, Il1b, Il6, Tnf in the lung, liver, kidney, eye, and joints of mice and, like vasoinhibin, these oligopeptides promoted the lysis of plasma fibrin clots by binding to plasminogen activator inhibitor-1 (PAI-1). Moreover, the inhibition of PAI-1, urokinase plasminogen activator receptor, or NF-{kappa}B prevented the apoptotic and inflammatory actions. In conclusion, the functional properties of vasoinhibin are segregated into two different structural determinants. Because apoptotic, inflammatory, and fibrinolytic actions may be undesirable for antiangiogenic therapy, HGR-containing vasoinhibin analogs stand as selective and safe agents for targeting pathological angiogenesis.

cell biology↗