MiR-590-3p Inhibits Pyroptosis In Diabetic Retinopathy By Targeting NLRP1 And Inactivating The NOX4 Signaling Pathway

Purpose: The current study aims to detect the expression of miR-590-3p,Caspase-1 and IL-1β in human retinal microvascular endothelial cells(HRMECs)incubated with high glucose(HG),and to clarify the role of pyroptosis in diabetic retinopathy(DR).Furthermore,we elucidate the mechanism whereby miR-590-3p regulates pyroptosis in DR.Methods: HRMECs incubated with HG were used to establish cell models,and the expression levels of miR-590-3p,Caspase-1,IL-1β,NLRP1,NOX4,TXNIP,NLRP3,and ROS were determined via Western blot,real-time PCR,immunofluorescence staining or flow cytometry.Additionally,miR-590-3p was altered using a mimic or an inhibitor,and si RNAs targeting NLRP1 and NOX4 were applied to explore the regulatory mechanism of miR-590-3p in DR.The relationships between miR-590-3p and NLRP1/NOX4 were also investigated using a luciferase reporter assay.Furthermore,vitreous tissue samples were collected to confirm pyroptosis in clinical DR.Results: Caspase-1 and IL-1β levels were upregulated in a cell culture model of DR,and the downregulated miR-590-3p and upregulated NLRP1/NOX4 were also observed.Inhibiting miR-590-3p upregulated NLRP1,the NOX4/ROS/TXNIP/NLRP3 pathway,and Caspase-1 levels.NLRP1 and NOX4 were confirmed as direct target genes of miR-590-3p using a luciferase reporter assay.The overexpression of miR-590-3p or knockdown of NLRP1 and NOX4 increased cell activity and suppressed pyroptosis.Intriguingly,the upregulation of IL-1β induced the downregulation of miR-590-3p by lowering the DNA promoter activity of pri-miR-590.Conclusion: HG induced pyroptosis in a cell culture model of DR,and the downregulation of miR-590-3p promoted pyroptotic death by targeting NLRP1 and activating the NOX4/ROS/TXNIP/NLRP3 pathway via an IL-1β-mediated positive feedback loop.