MicroRNA-23a-3p ameliorates acute kidney injury by targeting FKBP5 and NF-κB signaling in sepsis

Low miR-23a-3p expression in patients with acute kidney injury (AKI) or sepsis has been revealed. However, the specific role of miR-23a-3p in AKI remains unclear. Our study aimed to determine the function of miR-23a-3p in AKI. Exposure to lipopolysaccharide (LPS) was used to induce cell injury in vitro. Cecal ligation and puncture (CLP) surgery was used to establish an animal model of septic AKI. Bioinformatics analysis and a wide range of experiments, including RT-qPCR, luciferase reporter, western blot, ELISA, TUNEL, hematoxylin and eosin staining, and immunofluorescence assays were conducted. The experimental results revealed that LPS exposure induced the significant apoptosis and inflammatory response of HK-2 cells, and miR-23a-3p exhibited a low expression in LPS-exposed HK-2 cells. Functionally, miR-23a-3p overexpression inhibited cell apoptosis and release of inflammatory cytokines including interleukin (IL)-1β, IL-6 and IL-8. Mechanistically, miR-23a-3p bound to the FKBP prolyl isomerase 5 (FKBP5) 3' untranslated region and negatively regulated its expression at mRNA and protein levels. Rescue assays indicated that FKBP5 overexpression reversed the influence of miR-23a-3p mimics on cell apoptosis and inflammatory response. Furthermore, miR-23a-3p overexpression attenuated the sepsis-induced impairment of renal function and the inflammatory response in mice with AKI. Finally, the knockdown of FKBP5 inactivated the nuclear factor kappaB (NF-κB) signaling by inactivating NF-κB nuclear translocation, and thereby inhibited the release of proinflammatory cytokines. Overall, our study demonstrates that miR-23a-3p ameliorates sepsis induced AKI by targeting FKBP5 and inactivating the NF-κB signaling, implying a potential therapeutic or diagnostic target for AKI.