ALY688 Protects Against Ferroptosis Via Nrf2 Activation in Skeletal Muscle

Abstract

Ferroptosis is a regulated form of cell death that is characterized by excessive lipid peroxidation. Arachidonic acid (AA), a polyunsaturated fatty acid (PUFA), can be incorporated into cell membrane phospholipids, thereby increasing their susceptibility to oxidative damage and ultimately ferroptosis. In this study, AA was found to enhance susceptibility to ferroptosis in both rat L6 cells and human iPSC-derived skeletal muscle cells. In the presence of AA, cells responded to iron overload (IO) with elevated oxidative stress, total cellular lipid peroxidation and mitochondrial lipid peroxidation, culminating in more ferroptotic cell death. These effects were significantly attenuated by ALY688, an adiponectin receptor agonist. We observed that ALY688 activated Nrf2 signaling in both L6 and iPSC-derived skeletal muscle cells and that the cytoprotective effect of ALY688 was abolished by ML385, an Nrf2 inhibitor. Together, these findings identified that AA increased skeletal muscle cell susceptibility to detrimental effects of iron and established that ALY688 mitigated the combined effects of AA and IO via an Nrf2-dependent mechanism.