Topical antiangiogenic SRPK1 inhibitors reduce choroidal neovascularization in rodent models of exudative AMD

• Published in: Investigative ophthalmology & visual science 2013-09, Vol.54 (9), p.6052-6062
• Main Authors: Gammons, Melissa V, Fedorov, Oleg, Ivison, David, Du, Chunyun, Clark, Tamsyn, Hopkins, Claire, Hagiwara, Masatoshi, Dick, Andrew D, Cox, Russell, Harper, Steven J, Hancox, Jules C, Knapp, Stefan, Bates, David O
• Format: Article
• Language: English
• Subjects: Animals; Cells, Cultured; Choroidal Neovascularization - drug therapy; Choroidal Neovascularization - genetics; Choroidal Neovascularization - metabolism; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Humans; Macular Degeneration - complications; Macular Degeneration - genetics; Macular Degeneration - metabolism; Mice; Mice, Inbred C57BL; Ophthalmic Solutions - administration & dosage; Polymerase Chain Reaction; Protein Kinase Inhibitors - administration & dosage; Protein Serine-Threonine Kinases - antagonists & inhibitors; Protein Serine-Threonine Kinases - metabolism; Rats; Retinal Pigment Epithelium - drug effects; Retinal Pigment Epithelium - metabolism; Retinal Pigment Epithelium - pathology; RNA - genetics; RNA Splicing; Vascular Endothelial Growth Factor A - biosynthesis; Vascular Endothelial Growth Factor A - genetics
• ISSN: 1552-5783; 0146-0404; 1552-5783
• DOI: 10.1167/iovs.13-12422

Exudative AMD (wet AMD) is treated by monthly injection into the eye of anti-VEGF proteins. VEGF is alternatively spliced to produce numerous isoforms that differ in angiogenic activity. Serine-rich protein kinase-1 (SRPK1) has been identified as a regulator of pro-angiogenic VEGF splicing by phosphorylating serine-rich splicing factor-1 (SRSF1), which binds to VEGF pre-mRNA. We tested the hypothesis that topical (eye drop) SRPK1-selective inhibitors could be generated that reduce pro-angiogenic isoforms, and prevent choroidal neovascularization in vivo. Novel inhibitors were tested for SRPK inhibition in vitro, pro-angiogenic VEGF production in RPE cells by PCR and ELISA, and for inhibition of choroidal neovascularisation in mice and rats. A novel disubstituted furan inhibitor was selective for the SRPK family of kinases and reduced expression of pro-angiogenic but not antiangiogenic VEGF isoforms. This inhibitor and previously identified SRPK inhibitors significantly reduced choroidal neovascularisation in vivo. Topical administration of SRPK inhibitors dose-dependently blocked CNV with an EC50 of 9 μM. These results indicate that novel SRPK1 selective inhibitors could be a potentially novel topical (eye drop) therapeutic for wet AMD.