AICAR Attenuates Ischemia-Reperfusion-Induced AKI by Modulating AMPK-TXNIP-NLRP3 Pathway and Energy Metabolism

This study aims to elucidate the synergistic protective mechanism of the AMPK agonist 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) in renal ischemia-reperfusion injury-associated acute kidney injury (IRI-AKI). By establishing a hypoxia/reoxygenation (H/R) injury model using human proximal tubule cells (HK-2) and IRI-AKI rat model, and employing molecular techniques including qRT-PCR, western blotting, serum biochemical assays, renal tissue hematoxylin and eosin staining, immunofluorescence, and transmission electron microscopy (TEM), we demonstrated that AICAR activates AMPK, leading to the significant downregulation of TXNIP and NLRP3, blocks Caspase-1-dependent release of IL-1β and IL-18, and ultimately suppresses pyroptosis, thereby alleviating renal inflammatory injury. Furthermore, AICAR restored mitochondrial membrane potential and ATP levels in H/R-treated HK-2 cells, reduced reactive oxygen species production in renal tissues of IRI-AKI rats, and elevated levels of antioxidant enzymes. Concurrently, utilizing targeted metabolomics technology, we discovered that AICAR effectively restores the levels of multiple metabolites associated with glycolysis, the TCA cycle, the urea cycle, and tryptophan metabolism and alleviates lipid deposition in IRI-AKI. This confirms that AICAR alleviates IRI-AKI by activating AMPK to restore impaired cellular energy metabolism, improve mitochondrial function, and ameliorate oxidative stress. Notably, this study is the first to reveal that AICAR, via AMPK activation, synchronously regulates dual protective pathways: "pyroptosis inhibition" and "energy metabolism remodeling." This synergistic protective mechanism may represent the core advantage distinguishing AICAR from other potential therapeutic strategies, highlighting its substantial translational potential as a multi-mechanism synergistic therapeutic agent. Our findings provide an innovative dual-regulatory ("pyroptosis-energy metabolism") therapeutic strategy for the clinical prevention and treatment of IRI-AKI.