Dexmedetomidine attenuates ferroptosis by Keap1-Nrf2/HO-1 pathway in LPS-induced acute kidney injury.

ABSTRACT

Previous research has demonstrated that Dexmedetomidine (DEX), an α2 adrenergic agonist commonly used for its sedative and analgesic properties, can attenuate lipopolysaccharide (LPS)-induced acute kidney injury (AKI). This study explores the possibility that DEX's protective effects in LPS-induced AKI are mediated through the inhibition of ferroptosis, a form of regulated cell death characterized by iron-dependent lipid peroxidation, and the activation of the antioxidant response through the Keap1/Nrf2/HO-1 signaling pathway. We induced AKI in 42 mice using LPS and divided them into six groups saline control, LPS, LPS + DEX, LPS + Ferrostatin-1 (LPS + Fer-1; a ferroptosis inhibitor), LPS + DEX with α2-receptor antagonist Altipamizole (LPS + DEX + ATI), and LPS + DEX with Nrf2 inhibitor ML385 (LPS + DEX + ML385). After 24 h, we analyzed blood and kidney tissues. LPS exposure resulted in AKI, with increased serum creatinine, BUN, and cystatin C, and tubular damage, which DEX and Fer-1 ameliorated. However, Altipamizole and ML385 negated these improvements. The LPS group exhibited elevated oxidative stress markers and mitochondrial damage, reduced by DEX and Fer-1, but not when α2-adrenergic or Nrf2 pathways were blocked. Nrf2 and HO-1 expression declined in the LPS group, rebounded with LPS + DEX and LPS + Fer-1, and fell again with inhibitors; inversely, Keap1 expression varied. Our results demonstrate that DEX may protect against LPS-induced AKI, at least partially by regulating ferroptosis and the α2-adrenergic receptor/Keap1/Nrf2/HO-1 pathway, suggesting a potential therapeutic role for DEX in AKI management by modulating cell death and antioxidant defenses.