VEGF/VEGFR2 blockade does not cause retinal atrophy in AMD-relevant models
Da Long, … , Lili Lu, Peter A. Campochiaro
Da Long, … , Lili Lu, Peter A. Campochiaro
Published May 17, 2018
Citation Information: JCI Insight. 2018;3(10):e120231. https://doi.org/10.1172/jci.insight.120231.
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Research Article Angiogenesis Ophthalmology

VEGF/VEGFR2 blockade does not cause retinal atrophy in AMD-relevant models

Abstract

Intraocular injections of VEGF-neutralizing proteins provide tremendous benefits in patients with choroidal neovascularization (NV) due to age-related macular degeneration (AMD), but during treatment some patients develop retinal atrophy. Suggesting that VEGF is a survival factor for retinal neurons, a clinical trial group attributed retinal atrophy to VEGF suppression and cautioned against frequent anti-VEGF injections. This recommendation may contribute to poor outcomes in clinical practice from insufficient treatment. Patients with type 3 choroidal NV have particularly high risk of retinal atrophy, an unexplained observation. Herein we show in mouse models that VEGF signaling does not contribute to photoreceptor survival and functioning: (a) neutralization of VEGFR2 strongly suppresses choroidal NV without compromising photoreceptor function or survival; (b) VEGF does not slow loss of photoreceptor function or death in mice with inherited retinal degeneration, and there is no exacerbation by VEGF suppression; and (c) mice with type 3 choroidal NV develop retinal atrophy due to oxidative damage with no contribution from VEGF suppression. Intraocular injections of VEGF-neutralizing proteins, a highly effective treatment in patients with neovascular AMD, should not be withheld or reduced due to concern that they may contribute to long-term visual loss from retinal atrophy.

Authors

Da Long, Yogita Kanan, Jikui Shen, Sean F. Hackett, Yuanyuan Liu, Zibran Hafiz, Mahmood Khan, Lili Lu, Peter A. Campochiaro

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Figure 2

Effect of VEGF or VEGFR blockade on photoreceptor function and survival in rd10 mice with inherited retinal degeneration.

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Effect of VEGF or VEGFR blockade on photoreceptor function and survival ...
Rd10 mice were given an intravitreous injection of 100 ng of VEGF (n = 6) or PBS (n = 6) on P14, P21, and P28 or they were given subcutaneous injections of 5 μg of the VEGFR tyrosine kinase inhibitor SU4312 (n = 6) or vehicle (n = 6) every 5 days starting at P14. At P35, electroretinography showed that compared with eyes injected with vehicle control, those injected with VEGF had no significant differences in mean (±SEM) scotopic a-wave amplitudes (A), mean (±SEM) scotopic b-wave amplitudes (B), or mean (±SEM) photopic b-wave amplitudes (C). Compared with mice given subcutaneous vehicle injections, those given injections of SU4312 had no significant differences in mean (±SEM) scotopic a-wave amplitudes (D), mean (±SEM) scotopic b-wave amplitudes (E), or mean (±SEM) photopic b-wave amplitudes (F). At P35, mice were euthanized and retinal homogenates were immunoblotted for rhodopsin kinase (GRK1) and actin. The bands for GRK1 from vehicle-injected control eyes, VEGF-injected eyes, and eyes from mice treated with SU4312 appeared very similar (G). The mean (±SEM) ratio of GRK1/actin densitometry readings were not significantly different between VEGF (n = 3) or SU4312 (n = 3) and vehicle controls (n = 3) by ANOVA with Bonferroni’s correction for multiple comparisons (H).