Mechanism of circRNA_0076631 mediated diabetic retinopathy by regulating pyroptosis

AIM: To investigate the role of pyroptosis in the development of diabetic retinopathy(DR)and to explore the regulatory mechanism by which circular RNA(circRNA)and its targeted microRNA(miRNA)mediate pyroptosis in DR, providing new therapeutic targets and strategies for the prevention and treatment of DR.METHODS: A streptozotocin(STZ)-induced model of type 1 diabetes in SD rats was established. The expression of circRNA_0076631, miR-214, and pyroptosis-related factors were measured in retinal tissues. CCK-8 and tube formation assays were used to detect the effect of different concentration of glucose on cell proliferation and angiogenic abilities of human retinal microvascular endothelial cells(HRMECs). The expression levels of circRNA_0076631, miR-214, and pyroptosis-related markers were evaluated through qRT-PCR and Western blot analysis, with additional experiments conducted following circRNA_0076631 knockdown to assess its effect on pyroptosis markers. Previous bioinformatics analysis and luciferase reporter assays identified a shared binding site among circRNA_0076631, miR-214, and caspase-1. To clarify the interaction between these molecules, co-transfection experiments using circRNA_0076631 inhibitors(ASO-circRNA_0076631), miR-214 overexpression transfection reagent, and miR-214 inhibitors(AMO-miR-214)were conducted to elucidate the regulatory pathway involved in DR.RESULTS: Both the diabetic rat model and D-glucose-treated HRMECs showed significantly elevated expression of circRNA_0076631 and pyroptosis-related factors(NLRP3, caspase-1, and IL-1β), while miR-214 expression was reduced(all P<0.05). The mRNA expression of pyroptosis-related factors caspase-1 was reduced after the overexpression of miR-214, and it was upregulated after the inhibition of miR-214(all P<0.05). Knockdown of circRNA_0076631 reduced the mRNA expression of pyroptosis markers caspase-1(P<0.05). Co-transfection experiments revealed that the inhibition circRNA_0076631 suppressed pyroptosis(all P<0.05), but this suppression was reversed upon co-transfection with miR-214 inhibitors, leading to increased mRNA expression of the pyroptosis marker caspase-1(all P<0.05).CONCLUSION: The circRNA_0076631 and pyroptosis play critical roles in the pathogenesis of DR, and circRNA_0076631 may regulate pyroptosis by modulating miR-214, which in turn influences the expression of caspase-1 in the pyroptosis signaling pathway, thereby contributing to DR progression. The circRNA_0076631 may serve as a novel therapeutic target, providing new insights for the prevention and treatment of DR.