Elucidating the contribution of mitochondrial glutathione to ferroptosis in cardiomyocytes
Sehwan Jang,
Xavier R. Chapa-Dubocq,
Yulia Y. Tyurina,
Claudette M. St Croix,
Alexandr A. Kapralov,
Vladimir A. Tyurin,
Hülya Bayır,
Valerian E. Kagan,
Sabzali Javadov
Affiliations
Sehwan Jang
Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR, 00936- 5067, USA
Xavier R. Chapa-Dubocq
Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR, 00936- 5067, USA
Yulia Y. Tyurina
Department of Environmental and Occupational Health, Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA, 15260, USA
Claudette M. St Croix
Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, 15260, USA
Alexandr A. Kapralov
Department of Environmental and Occupational Health, Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA, 15260, USA
Vladimir A. Tyurin
Department of Environmental and Occupational Health, Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA, 15260, USA
Hülya Bayır
Department of Environmental and Occupational Health, Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA, 15260, USA; Department of Critical Care Medicine, University of Pittsburgh, and Children's Neuroscience Institute, UPMC Children's Hospital, Pittsburgh, PA, 15260, USA
Valerian E. Kagan
Department of Environmental and Occupational Health, Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA, 15260, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15260, USA; Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA; Department of Radiation Oncology, University of Pittsburgh, Pittsburgh, PA, 15260, USA
Sabzali Javadov
Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR, 00936- 5067, USA; Corresponding author.
Ferroptosis is a programmed iron-dependent cell death associated with peroxidation of lipids particularly, phospholipids. Several studies suggested a possible contribution of mitochondria to ferroptosis although the mechanisms underlying mitochondria-mediated ferroptotic pathways remain elusive. Reduced glutathione (GSH) is a central player in ferroptosis that is required for glutathione peroxidase 4 to eliminate oxidized phospholipids. Mitochondria do not produce GSH, and although the transport of GSH to mitochondria is not fully understood, two carrier proteins, the dicarboxylate carrier (DIC, SLC25A10) and the oxoglutarate carrier (OGC, SLC25A11) have been suggested to participate in GSH transport. Here, we elucidated the role of DIC and OGC as well as mitochondrial bioenergetics in ferroptosis in H9c2 cardioblasts. Results showed that mitochondria are highly sensitive to ferroptotic stimuli displaying fragmentation, and lipid peroxidation shortly after the onset of ferroptotic stimulus. Inhibition of electron transport chain complexes and oxidative phosphorylation worsened RSL3-induced ferroptosis. LC-MS/MS analysis revealed a dramatic increase in the levels of pro-ferroptotic oxygenated phosphatidylethanolamine species in mitochondria in response to RSL3 (ferroptosis inducer) and cardiac ischemia-reperfusion. Inhibition of DIC and OGC aggravated ferroptosis and increased mitochondrial ROS, membrane depolarization, and GSH depletion. Dihydrolipoic acid, an essential cofactor for several mitochondrial multienzyme complexes, attenuated ferroptosis and induced direct reduction of pro-ferroptotic peroxidized phospholipids to hydroxy-phospholipids in vitro. In conclusion, we suggest that ferroptotic stimuli diminishes mitochondrial bioenergetics and stimulates GSH depletion and glutathione peroxidase 4 inactivation leading to ferroptosis.
