FIS1 and acute kidney injury: Mechanistically, high lactate levels mediate the lactylation of mitochondrial fission 1 protein (Fis1) lysine 20 (Fis1 K20la), which promotes excessive mitochondrial fission and subsequently induces ATP depletion, mitochondrial reactive oxygen species overproduction, mitochondrial apoptosis, and exacerbates sepsis-induced AKI.