Fig. 5: Intravitreous injection of sunitinib MPs in mice with type 3 CNV reduces photoreceptor cell death.

Rho/VEGF mice were given an intravitreous injection of 10 µg of sunitinib microparticles (Suni MP) in one eye and 10 µg of empty MP in the other eye or 40 µg of aflibercept in one eye and PBS in the fellow eye. At P42, mice (n = 7 for each group) were euthanized and serial frozen ocular sections were cut from the superior pole of the eye (S0) to the inferior pole (I0) and sections 25% (S1 and I1), 50% (S2 and I2), and 75% (S3 and I3) of the distance between each pole and the optic nerve (ON) were stained with hematoxylin and outer nuclear layer (ONL) thickness was measured by image analysis by a masked investigator. The ONL of sections from the S2 location of Suni MP-injected eyes appeared thicker than those from empty MP-injected eyes, but those from aflibercept-injected eyes appeared similar to those from PBS-injected eyes (a scale bar = 100 µm). The mean (±SEM) ONL thickness was significantly greater at three of six locations in Suni MP-injected eyes compared with empty MP-injected eyes, but there was no difference between aflibercept- and PBS-injected eyes (b). At P49, mice (n = 5 for each group) were euthanized and immunoblots of retinal homogenates from Suni MP-injected eyes showed prominent bands for rhodopsin kinase (GRK-1) (c). Denistometry showed that the mean (±SEM) GRK-1/Actin ratio was significantly greater in retinas from Suni MP-injected eyes compared with empty MP-injected fellow eyes, but not aflibercept-injected eyes vs. PBS-injected fellow eyes (d). *p < 0.05 by Mann Whitney for difference from fellow eye empty MP control. Source data are provided as a Source Data file.