Evaluation of EB-203 as a potential treatment for non-proliferative diabetic retinopathy using a zebrafish model

This study aimed to evaluate the therapeutic efficacy of EB-203 using a zebrafish model that exhibits diabetic retinopathy like vascular alterations.

To assess the toxicity of EB-203, embryos obtained from Tg(flk:EGFP) adult zebrafish were exposed to various concentrations of the compound (6.25, 12.5, 25, 50, 100, 200, and 400 μg/mL). To evaluate its efficacy against DR-like phenotypes, normally developed embryos at 3 days post-fertilization (dpf) were treated with EB-203 under hyperglycemic conditions. At 6 dpf, retinal tissues were isolated to measure retinal vessel diameter changes. Microarray analysis was performed to identify changes in DR-related gene expression following EB-203 treatment, and selected markers were validated using RT-PCR. Histological alterations in the retinal layers were analyzed through H&E staining, TUNEL assays, and immunofluorescence.

In the zebrafish model, EB-203 administration ameliorated retinal vessel dilation like phenotypes and improved vascular permeability like alterations. Moreover, EB-203 reduced expression of inflammatory markers in the retina by downregulating the NF-κB signaling pathway, thereby alleviating NPDR like features in hyperglycemic larvae.

EB-203 was found to reduce microvascular leakage changes, edema features, and inflammatory responses associated with NPDR-like phenotypes, suggesting its potential to limit progression toward PDR conditions. Overall, EB-203 demonstrated significant efficacy in improving NPDR like retinal pathology in zebrafish and holds promise as a potential therapeutic candidate for DR.