Abstract
Purpose :
Diabetic macular edema (DME) and neovascular age-related macular degeneration (nAMD) are leading causes of vision loss and blindness worldwide. Despite the success of anti-vascular endothelial growth factor (VEGF) therapies in treating these diseases, a significant proportion of patients do not achieve adequate improvement in vision. Therefore, new therapies with novel mechanisms of action are needed. To explore the therapeutic potential of Rho kinase (ROCK) and protein kinase C (PKC) inhibitors in DME and nAMD, we investigated the effects of a ROCK/PKC inhibitor, AR-13503, on angiogenesis and retinal pigment epithelium (RPE) permeability using in vitro and ex vivo models.
Methods :
The anti-angiogenic effect of AR-13503 was evaluated using an in vitro human umbilical vein endothelial cell (HUVEC) tube formation assay and an ex vivo mouse choroidal explant angiogenesis sprouting assay. HUVEC cells were plated in Matrigel® and treated with AR-13503 overnight. To determine the effect of AR-13503 on choroidal sprouting, choroidal punches were isolated from C57BL/6J mice and cultured in Matrigel® with the addition of endothelium growth medium. Explants were then treated with various concentrations of AR-13503 for 5 days. Choroidal angiogenesis was quantified by measuring the area of the choroidal sprouting. To test RPE barrier function in the presence of AR-13503, we cultured primary porcine RPEs on transwell inserts and measured the transepithelial resistance (TER) following treatment with various concentrations of the compound.
Results :
AR-13503 inhibited HUVEC tube formation with an IC50 of 21 nM. In the choroidal sprouting assay, the sprouting area was reduced dose-dependently in the presence of AR-13503. In the RPE permeability assay, primary porcine RPEs established high TER (~800 Ohm.cm2) after 2-weeks of culture in transwell inserts with polarization-inducing medium. Treating these monolayers with 400 nM AR-13503 produced a 200% increase in TER.
Conclusions :
In ex vivo and in vitro assays, AR-13503 inhibited HUVEC vessel formation and mouse choroidal angiogenesis in a dose-depend manner. Moreover, AR-13503 also enhanced primary porcine RPE barrier function in a dose-dependent manner. These data support further study of AR-13503 as a potential new treatment for DME and nAMD.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.