Exendin-4, a GLP-1 receptor agonist, suppresses diabetic retinopathy <i>in vivo</i> and <i>in vitro</i>.

Diabetic retinopathy (DR) is a complication of diabetes and a leading cause of blindness in adults. Studies have shown that glucagon-like peptide-1 (GLP-1) exerts a protective effect on patients with DR. Here, we investigated the protective effects of Exendin-4, a GLP-1 analogue, on DR. We established a high-glucose-induced HREC cell model and an STZ-induced rat DR Model to study the effect of Exendin-4 in DR and . The qRT-PCR, CCK-8, TUNEL, western blotting, tube formation assays, and ELISA were performed. In addition, we overexpressed TGFB2 to observe whether the protective effect of Exendin-4 was reversed. Our results showed that Exendin-4 inhibited the progression of DR. Furthermore, the protective effect of Exendin-4 was suppressed in cells overexpressing TGFB2. Our findings suggest that Exendin-4 may be involved in the regulation of TGFB2 expression levels to inhibit DR. These results indicate that Exendin-4 could be an effective therapy for DR.