Vascular endothelial growth factor (
VEGF) A is implicated in aberrant angiogenesis and intravitreous neovascularization (IVNV) in
retinopathy of prematurity (ROP). However, VEGFA also regulates
retinal vascular development and functions as a
retinal neural survival factor. By using a relevant ROP model, the 50/10
oxygen-induced retinopathy (OIR) model, we previously found that broad inhibition of VEGFA bioactivity using a
neutralizing antibody to rat
VEGF significantly reduced IVNV area compared with control
IgG but also significantly reduced
body weight gain in the pups, suggesting an adverse effect. Therefore, we propose that knockdown of up-regulated VEGFA in cells that overexpress it under pathological conditions would reduce IVNV without affecting physiological
retinal vascular development or overall pup growth. Herein, we determined first that the VEGFA
mRNA signal was located within the inner nuclear layer corresponding to CRALBP-labeled Müller cells of pups in the 50/10 OIR model. We then developed a lentiviral-delivered miR-30eembedded
shRNA against VEGFA that targeted Müller cells. Reduction of VEGFA by lentivector VEGFA-shRNAetargeting Müller cells efficiently reduced 50/10 OIR up-regulated VEGFA and IVNV in the model, without adversely affecting physiological
retinal vascular development or pup
weight gain. Knockdown of VEGFA in rat Müller cells by lentivector VEGFA-
shRNA significantly reduced VEGFR2 phosphorylation in
retinal vascular endothelial cells. Our results suggest that targeted knockdown of overexpressed VEGFA in Müller cells safely reduces IVNV in a relevant ROP model.