The AGO2-ATOX1 axis exacerbates inflammation in a mouse sepsis model

The study aimed to investigate the mechanism of the Argonaute RISC catalytic component 2 (AGO2)-antioxidant protein 1 (ATOX1) axis in the inflammatory response of sepsis.

AGO2 was knocked down by tail vein injection of sh-Ago2 lentivirus, and a sepsis mouse model was established using the cecal ligation and puncture (CLP) method. RAW264.7 cells were transfected with AGO2 or ATOX1 knockdown or overexpression plasmids and treated with lipopolysaccharide (LPS) to construct a cellular sepsis model. Hematoxylin-eosin staining was used to evaluate lung and liver tissue damage in mice. Serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured using biochemical analysis. ELISA was performed to determine the levels of inflammatory cytokines: tumor necrosis factor α (TNF-α), interleukin (IL)-6, and IL-1 β. The expression of AGO2, ATOX1, inducible nitric oxide synthase (iNOS), and arginase 1 (Arg1) was analyzed using RT-qPCR and Western blotting. The effect of AGO2 on ATOX1 mRNA stability was assessed using an actinomycin D assay, and the interaction between AGO2 and ATOX1 was analyzed via RIP-qPCR.

AGO2 and ATOX1 were highly expressed in septic mice. In vitro experiments demonstrated that knockdown of AGO2 or ATOX1 suppressed LPS-induced inflammatory responses and macrophage polarization imbalance. AGO2 promoted M1 macrophage polarization and aggravated inflammatory damage by enhancing the stability of ATOX1 mRNA. In vivo experiments further confirmed that AGO2 knockdown significantly alleviated sepsis-induced lung and liver damage, reduced the inflammatory response, and inhibited ATOX1 expression.

AGO2 binds to ATOX1 mRNA, promoting ATOX1 expression, inducing macrophage polarization imbalance, and exacerbating sepsis-induced inflammatory responses.