Diabetic retinopathy: Research advances in canonical cellular pathways and emerging mechanisms

As the most common microvascular complication of diabetes, diabetic retinopathy (DR) has become a leading cause of blindness among the global diabetic population. The pathogenesis of DR is not yet fully understood, and current clinical treatment options are limited and have suboptimal efficacy. A detailed investigation of the intercellular communication mechanisms during the progression of DR is of paramount importance. In this study, we first synthesized findings from various studies on classical pathways, including VEGF signaling, oxidative stress, inflammatory cascades, the polyol pathway, PKC signaling, and the Wnt/β-catenin pathway, with a focus on elucidating the cell-type specificity of each pathway and the interactions among them. Subsequently, we explored emerging mechanisms identified in recent years, such as the ethanolamine pathway, ANGPTL4, Lrg1, and Norrin-FZD4, to expand our understanding of the pathogenesis of DR. Through a systematic investigation of multiple pathways, we propose that the progression of DR is not driven by the effect of a single pathway but rather results from the dynamic interplay among these signaling networks. Additionally, we described recent advances in the clinical translation of related pathways, including multitarget therapeutic strategies and precision interventions mediated by pathway-specific biomarkers. This review aims to provide a comprehensive and integrative perspective on the mechanisms underlying DR, thereby establishing a theoretical foundation for experimental research and clinical translation.