Circular RNA circVMA21 ameliorates lipopolysaccharide (LPS)-induced acute kidney injury by targeting the miR-199a-5p/NRP1 axis in sepsis

Background: Sepsis is a serious and elusive syndrome caused by infection, with high mortality worldwide. Circular RNAs vacuolar ATPase assembly factor (circVMA21) has been reported to be related to the inflammatory damages in sepsis. This study is designed to explore the role and mechanism of circVMA21 in the lipopolysaccharide (LPS)-induced cell injury in sepsis. Methods: Cell viability and apoptosis were detected by CCK-8, and flow cytometry assays. CircVMA21, microRNA-199a-5p (miR-199a-5p), and Neuropilin-1 (NRP1) level were determined by RT-qPCR. Protein levels of Bcl-2, Bax, cleaved-caspase 3, and NRP1 were examined by Western blot assay. IL-1b, IL-6, and TNF-a were detected using ELISA. Superoxide Dismutase (SOD) and glutathione (GSH) were measured by the special kits. The binding relationship between miR-199a-5p and circVMA21 or NRP1 was predicted by Starbase 3.0 and then verified by a dual-luciferase reporter and RIP assays. Results: CircVMA21 and NRP1 were decreased, and miR-199a-5p was increased in LPS-induced THP1 cells. Moreover, circVMA21 overexpression could repress LPS-mediated cell viability, apoptosis, inflammation, and oxidative stress in THP-1 cells. The mechanical analysis suggested that circVMA21 regulated NRP1 expression through sponging miR-199a-5p. Conclusion: CircVMA21 upregulation could attenuate LPS-triggered THP-1 cell injury through modulating the miR-199a-5p/NRP1 axis, hinting an underlying therapeutic strategy for sepsis patients. (c) 2021 Elsevier Inc. All rights reserved.