Objective To investigate the role and potential mechanism of glutathione peroxidase 3 (GPX3) in ischemia-reperfusion injury (IRI) during kidney transplantation.

Methods C57BL/6 mice were divided into four groups according to different interventions: sham operation group (Sham group), kidney transplantation group (KT group), kidney transplantation + GPX3 overexpression group (KT+GPX3 group) and kidney transplantation + GPX3 overexpression + reactive oxygen species (ROS) agonist group (KT+GPX3+CADD522 group). Twenty-four hours after model establishment, inferior vena cava blood was collected to detect blood urea nitrogen (BUN) and serum creatinine (Scr). Left renal tissues were harvested for immunofluorescence staining to detect ROS and NADPH oxidase 2 (NOX2). Enzyme-linked immunosorbent assay (ELISA) was performed to measure neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), tumor necrosis factor (TNF) -α and interleukin (IL)-1β. Western blotting was used to detect myeloperoxidase (MPO) and citrullinated histone H3 (CitH3).

Results Compared with the Sham group, the expression level of GPX3 was decreased in the KT group; compared with the KT group, GPX3 expression was increased in the KT+GPX3 group; compared with the KT+GPX3 group, GPX3 expression was reduced in the KT+GPX3+CADD522 group (all P<0.05). Compared with the Sham group, the levels of Scr, BUN, NGAL and KIM-1 were elevated in the KT group; compared with the KT group, the above indicators were decreased in the KT+GPX3 group; compared with the KT+GPX3 group, the levels of Scr, BUN, NGAL and KIM-1 were increased in the KT+GPX3+CADD522 group (all P<0.05). Compared with the Sham group, the expression levels of NOX2 and ROS were increased in the KT group; compared with the KT group, NOX2 and ROS levels were decreased in the KT+GPX3 group; compared with the KT+GPX3 group, NOX2 and ROS levels were upregulated in the KT+GPX3+CADD522 group (all P<0.05). Compared with the Sham group, the expression levels of MPO and CitH3 were increased in the KT group; compared with the KT group, MPO and CitH3 levels were decreased in the KT+GPX3 group; compared with the KT+GPX3 group, MPO and CitH3 levels were increased in the KT+GPX3+CADD522 group (all P<0.05). Compared with the Sham group, the expression levels of TNF-α and IL-1β were increased in the KT group; compared with the KT group, TNF-α and IL-1β levels were decreased in the KT+GPX3 group; compared with the KT+GPX3 group, TNF-α and IL-1β levels were increased in the KT+GPX3+CADD522 group (all P<0.05).

Conclusions GPX3 may alleviate renal tissue inflammation by inhibiting ROS-mediated neutrophil extracellular trap (NET) formation, thereby attenuating IRI in renal transplantation.