Dynamic profile of malondialdehyde in renal and hepatic ischemia reperfusion injury: an explorative study of internal historical samples

BackgroundFerroptosis has emerged as a promising therapeutic target in IRI. However, it remains largely unclear how and when this iron-dependent regulated cell death manifests during IRI. Therefore, we explored malondialdehyde (MDA), a byproduct of lipid peroxidation, and glutathione peroxidase 4 (GPX4), as a marker of redox capacity, in multiple IRI models. With this explorative study, we aimed to uncover MDA dynamics in renal and hepatic IRI, which could provide valuable insights for future internal studies. MethodsHistorical plasma and tissue samples from rat and porcine models of renal and hepatic IRI were selected based on varying conditions of ischemic injury, reperfusion and perfusion. MDA was measured using a colorimetric assay with N-methyl-2-phenylindole, methanol, acetonitrile and hydrochloric acid and quantified at 595 nm. GPX4 protein concentrations were investigated using standard western blotting. ResultsIn rat clamping models, plasma MDA concentrations revealed no difference between control and IRI settings. However, an increasing trend could be observed in tissue samples after IRI. Similarly, a decrease in tissue GPX4 concentrations was observed after IRI. In porcine studies, MDA concentrations were increased during reperfusion of kidneys exposed to prolonged warm ischemia and livers exposed to short periods of cold ischemia. Dynamic preservation could attenuate MDA concentrations. ConclusionWe found that MDA and GPX4 are affected within the first hours after reperfusion, stressing the need for early sampling in studies focusing on characterizing ferroptosis. Moreover, MDA dynamics during organ perfusion revealed an increased vulnerability of ischemic organs to lipid peroxidation and a potential protective effect of dynamic preservation. These preliminary results should be confirmed in studies focusing on ferroptosis characterization, as notable observations regarding sample age and storage conditions and experimental design limit the validity of this study.