SRC Promotes High Glucose-Induced Retinal Endothelial Dysfunction by Suppressing FUNDC1-Mediated Mitophagy in Diabetic Retinopathy.

Purpose

Diabetic retinopathy (DR) is a leading cause of blindness, yet the role of mitophagy in its pathogenesis remains unclear. This study aims to dissect mitophagy heterogeneity in DR at single-cell resolution and identify key regulators.

Methods

Bulk RNA-seq datasets were first used to screen mitophagy-related genes associated with DR, followed by single-cell RNA-seq analysis to define cell-type-specific mitophagy alterations. Mitophagy activity was scored by four methods (AddModuleScore, AUCell, ssGSEA, and PercentageFeatureSet). Cell communication and pseudotime trajectories were inferred with CellChat and Monocle3. The function of SRC in high glucose-induced human retinal endothelial cells (HRECs) was validated by RT-qPCR, Western blot, CCK-8, Transwell, and transmission electron microscopy.

Results

Endothelial cells exhibited the highest mitophagy activity in DR. Immature endothelial cells showed the highest mitophagy scores and occupied a key transition state in differentiation trajectory. SRC was consistently upregulated in DR and its knockdown restored mitophagy by promoting FUNDC1-LC3 interaction, thereby suppressing high glucose-induced proliferation and migration of HRECs.

Conclusion

This study reveals cell-specific mitophagy dysregulation in DR and identifies SRC as a critical regulator of FUNDC1-mediated mitophagy. Targeting SRC may offer a novel therapeutic strategy for DR.