title: Aflibercept Traps Galectin-1, an Angiogenic Factor Associated with Diabetic Retinopathy.
abstract: Vascular endothelial growth factor (VEGF)-A-driven angiogenesis contributes to various disorders including cancer and proliferative diabetic retinopathy (PDR). Among several VEGF-A blockers clinically used is aflibercept, a chimeric VEGFR1/VEGFR2-based decoy receptor fused to the Fc fragment of IgG1 (i.e., VEGFR1/VEGFR2-Fc). Here, we revealed a novel anti-angiogenic function for aflibercept beyond its antagonism against VEGF family members. Immunoprecipitation and mass spectrometry analyses identified galectin-1 as an aflibercept-interacting protein. Biolayer interferometry revealed aflibercept binding to galectin-1 with higher affinity than VEGFR1-Fc and VEGFR2-Fc, which was abolished by deglycosylation of aflibercept with peptide:N-glycosidase F. Retinal LGALS1/Galectin-1 mRNA expression was enhanced in vitro by hypoxic stimulation and in vivo by induction of diseases including diabetes. Galectin-1 immunoreactivity co-localized with VEGFR2 in neovascular tissues surgically excised from human eyes with PDR. Compared with non-diabetic controls, intravitreal galectin-1 protein levels were elevated in PDR eyes, showing no correlation with increased VEGF-A levels. Preoperative injection of bevacizumab, a monoclonal antibody to VEGF-A, reduced the VEGF-A, but not galectin-1, levels. Galectin-1 application to human retinal microvascular endothelial cells up-regulated VEGFR2 phosphorylation, which was eliminated by aflibercept. Our present findings demonstrated the neutralizing efficacy of aflibercept against galectin-1, an angiogenic factor associated with PDR independently of VEGF-A.
authors.affiliation: Laboratory of Ocular Cell Biology and Visual Science, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.|Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Kanda
authors.affiliation: Laboratory of Ocular Cell Biology and Visual Science, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.|Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.
authors.forename: Kousuke
authors.initials: K
authors.lastname: Noda
authors.affiliation: Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Saito
authors.affiliation: Laboratory of Ocular Cell Biology and Visual Science, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.|Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Ishida
mesh_terms: D043925:Angiogenesis Inducing Agents / Q000378:metabolism*; D002460:Cell Line; D003930:Diabetic Retinopathy / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D042783:Endothelial Cells / Q000378:metabolism; D037483:Galectin 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D011485:Protein Binding; D025941:Protein Interaction Mapping; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor / Q000378:metabolism* / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000378:metabolism* / Q000494:pharmacology; D055213:Retinal Pigment Epithelium / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: D043925:Angiogenesis Inducing Agents; D037483:Galectin 1; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D042461:Vascular Endothelial Growth Factor A; C533178:aflibercept; D040262:Receptors, Vascular Endothelial Growth Factor; D040301:Vascular Endothelial Growth Factor Receptor-2