Role of Hsa_circ_0000880 in the Regulation of High Glucose-Induced Apoptosis of Retinal Microvascular Endothelial Cells.

Purpose: Circular RNAs (circRNAs) have been verified to participate in multiple biological processes and disease progression. Yet, the role of circRNAs in the pathogenesis of diabetic retinopathy (DR) is still poorly understood and deserves further study. This study aimed to investigate the role of circRNAs in the regulation of high glucose (HG)-induced apoptosis of retinal microvascular endothelial cells (RMECs). Methods: Epiretinal membranes from patients with DR and nondiabetic patients with idiopathic macular epiretinal membrane were collected for this study. The circRNA microarrays were performed using high-throughput sequencing. Hierarchical clustering, functional enrichment, and network regulation analyses were used to analyze the data generated by high-throughput sequencing. Next, RMECs were subjected to HG (25 mM) conditions to induce RMECs apoptosis in vitro. A series of experiments, such as Transwell, the Scratch wound, and tube formation, were conducted to explore the regulatory effect of circRNA on RMECs. Fluorescence in situ hybridization (FISH), immunofluorescence staining, and Western blot were used to study the mechanism underlying circRNA-mediated regulation. Results: A total of 53 differentially expressed circRNAs were found in patients with DR. Among these, hsa_circ_0000880 was significantly upregulated in both the diabetic epiretinal membranes and in an in vitro DR model of HG-treated RMECs. Hsa_circ_0000880 knockout facilitated RMECs vitality and decreased the paracellular permeability of RMECs under hyperglycemia. More importantly, silencing of hsa_circ_0000880 significantly inhibited HG-induced ROS production and RMECs apoptosis. Hsa_circ_0000880 acted as an endogenous sponge for eukaryotic initiation factor 4A-III (EIF4A3). Knockout of hsa_circ_0000880 reversed HG-induced decrease in EIF4A3 protein level. Conclusions: Our findings suggest that hsa_circ_0000880 is a novel circRNA can induce RMECs apoptosis in response to HG conditions by sponging EIF4A3, offering an innovative treatment approach against DR. Translational Relevance: The circRNAs participate in the dysregulation of microvascular endothelial function induced by HG conditions, indicating a promising therapeutic target for DR.

Changes in the Lipid Profile of Aqueous Humor From Diabetic Cataract Patients.

Purpose: To identify the differential profiles of lipids in aqueous humor (AH) between control and diabetic cataract patients. Methods: The lipidomic profiles of 19 samples from patients with diabetic cataract (diabetic group) and 32 controls (control group) were analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS). Differentially expressed lipids between the two groups were determined through partial least-squares-discriminant analysis and principal component analysis. Receiver operating characteristic curve was calculated to evaluate the diagnostic value of differentially expressed lipids in distinguishing diabetic cataract patients from the control subjects. The correlations of the target lipids with the serum lipids were determined by Pearson correlation. Results: The results of LC-MS/MS analysis revealed a remarkable variation in lipid class composition. As compared with the control group, the percentage of triglycerides (TGs) was higher and that of Ceramide-1-phosphates was significantly lower in the AH of the diabetic group. A multivariate analysis of the lipid species showed that the expression levels of 16 of 639 lipids significantly changed in the diabetic group as compared to the control group. Among them, TG (42:6) (area under curve [AUC] = 0.985, P < 0.0001) and diacylglycerol (DG) (24:2) (AUC = 0.944, P < 0.0001) exhibited high prediction capability for diabetic cataract. The results of Pearson correlation revealed that the concentrations of TG (42:6) in AH were positively correlated with serum TG levels in diabetic patients. Conclusions: The lipid composition of AH of diabetic cataract patients showed a significant difference from that of the healthy subjects. Lipid changes, especially the high AH levels of TG (42:6) and DG (24:2), might contribute to cataractogenesis and possibly be involved in the development of diabetic cataract. Translational Relevance: Changes in the lipid profile of AH may partly account for the pathogenesis of diabetic cataracts and lead to a novel therapeutic strategy for diabetic cataract.