Anti-SPARC oligopeptide inhibits laser-induced CNV in mice

It is known that SPARC gates VEGF-A signal transduction towards KDR, the primary angiogenic VEGF receptor. We sought to determine whether inhibition of SPARC activity using anti-SPARC peptide could inhibit laser-induced CNV by promoting binding of VEGF-A to FLT-1. We created anti-SPARC l-peptide and retro-inverso anti-SPARC d-peptide. Anti-SPARC peptides or PBS were injected intravitreally 1 day before or after laser induction. Intravitreal injection of anti-SPARC l-peptide 1 day before laser induction promotes FLT-1 phosphorylation and inhibited laser-induced CNV and anti-SPARC d-peptide had no effect. Injection 1 day after laser injury did not affect size of laser-induced CNV. Inhibition of SPARC activity could be complementary to existing anti-CNV therapy.