Elevated expression of hsa_circ_0053004 in peripheral blood mononuclear cells correlates with endothelial dysfunction...

Diabetic retinopathy (DR) is a major microvascular complication of diabetes mellitus and a leading cause of vision loss. Circular RNAs (circRNAs) have emerged as promising biomarkers, yet their role in DR remains unclear. In this study, peripheral blood mononuclear cells (PBMCs) and aqueous humor samples from patients with diabetes mellitus and DR were analyzed by circRNA microarray, with candidate transcripts validated by real-time quantitative PCR. Receiver operating characteristic analysis was performed to assess diagnostic performance. Functional assays using human retinal microvascular endothelial cells (hRMECs), together with bioinformatic prediction and experimental validation, were employed to explore mechanistic pathways. Among the differentially expressed circRNAs, hsa_circ_0053004 was the most significantly upregulated in DR. Its elevated expression was confirmed in both PBMCs and aqueous humor, and gain-of-function studies demonstrated that hsa_circ_0053004 promotes endothelial dysfunction in hRMECs, at least in part through interactions with miR-139-5p and miR-23a-5p. ROC analysis further revealed its strong discriminative capacity between DR and diabetes mellitus. These findings suggest that hsa_circ_0053004 from PBMCs could serve as a potential diagnostic marker for DR and revealed that it is possibly associated with the pathological mechanisms of DR by affecting endothelial dysfunction.