Serum Exosomes miR-122-5P Induces Hepatic and Renal Injury in Septic Rats by Regulating TAK1/SIRT1 Pathway.

Aim: Sepsis is a potentially fatal condition characterized by organ failure resulting from an abnormal host response to infection, often leading to liver and kidney damage. Timely recognition and intervention of these dysfunctions have the potential to significantly reduce sepsis mortality rates. Recent studies have emphasized the critical role of serum exosomes and their miRNA content in mediating sepsis-induced organ dysfunction. The objective of this study is to elucidate the mechanism underlying the impact of miR-122-5p on sepsis-associated liver and kidney injury using inhibitors for miR-122-5p as well as GW4869, an inhibitor targeting exosome release. Materials and Methods: Exosomes were isolated from serum samples of septic rats, sepsis patients, and control groups, while liver and kidney tissues were collected for subsequent analysis. The levels of miR-122-5p, inflammation indices, and organ damage were assessed using PCR, ELISA, and pathological identification techniques. Immunohistochemistry and Western blotting methods were employed to investigate the activation of inflammatory pathways. Furthermore, big data analysis was utilized to screen potential targets of miR-122-5p in vivo. Key Findings: Serum exosomal levels of miR-122-5p were significantly elevated in septic patients as well as in LPS-induced septic rats. Inhibition of miR-122-5p reduced serum pro-inflammatory factors and ameliorated liver and kidney damage in septic rats. Mechanistically, miR-122-5p upregulated TAK1, downregulated SIRT1, and facilitated NF-κB activation. Conclusion: Serum exosomal miR-122-5p promotes inflammation and induces liver/kidney injury in LPS-induced septic rats by modulating the TAK1/SIRT1/NF-κB pathway, highlighting potential therapeutic targets for sepsis management.