Translocation of iron from lysosomes to mitochondria during ischemia predisposes to injury after reperfusion in rat hepatocytes.

摘要: The mitochondrial permeability transition (MPT) initiated by reactive oxygen species (ROS) plays an essential role in ischemia-reperfusion (IR) injury. Iron is a critical catalyst for ROS formation, and intracellular chelatable iron promotes oxidative injury-induced MPT-dependent cell death hepatocytes. Accordingly, our aim was to investigate the of IR-induced generation, MPT primary rat To simulate IR, overnight-cultured hepatocytes were incubated anoxically at pH 6.2 4h reoxygenated 7.4. Chelatable Fe(2+), ROS, membrane potential monitored confocal fluorescence microscopy calcein, chloromethyldichlorofluorescein, tetramethylrhodamine methyl ester, respectively. Cell killing assessed propidium iodide fluorimetry. Ischemia caused progressive quenching cytosolic calcein more than 90%, signifying increased Fe(2+). Desferal starch-desferal 1h before ischemia suppressed quenching. also induced dequenching loaded into mitochondria lysosomes, Desferal, starch-desferal, inhibitor Ca(2+) uniporter (MCU), Ru360, during ischemia. Ru360 decreased opening, after reperfusion. These results indicate that lysosomes release Fe(2+) ischemia, which taken up MCU. Increased then predisposes ROS-dependent opening