Red blood cells contain enzymatically active GPx4 whose abundance anticorrelates with hemolysis during blood bank storage
Jeffrey M. Stolwijk,
Jonathan A. Stefely,
Mike T. Veling,
Thomas J. van ‘t Erve,
Brett A. Wagner,
Thomas J. Raife,
Garry R. Buettner
Affiliations
Jeffrey M. Stolwijk
Free Radical and Radiation Biology Program, The University of Iowa Carver College of Medicine, Iowa City, IA, USA; Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, USA
Jonathan A. Stefely
Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, USA; Medical Scientist Training Program, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, USA
Mike T. Veling
Department of Systems Biology, Harvard Medical School, Boston, MA, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
Thomas J. van ‘t Erve
Free Radical and Radiation Biology Program, The University of Iowa Carver College of Medicine, Iowa City, IA, USA; Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, USA
Brett A. Wagner
Free Radical and Radiation Biology Program, The University of Iowa Carver College of Medicine, Iowa City, IA, USA
Thomas J. Raife
Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, USA; Corresponding author.
Garry R. Buettner
Free Radical and Radiation Biology Program, The University of Iowa Carver College of Medicine, Iowa City, IA, USA; Corresponding author.
The antioxidant function of the phospholipid hydroperoxide glutathione peroxidase (GPx4) is vital for the homeostasis of many cell types, from neoplastic cells to normal erythroid precursors. However, some functional proteins in erythroid precursors are lost during the development of red blood cells (RBCs); whether GPx4 is maintained as an active enzyme in mature RBCs has remained unclear. Our meta-analyses of existing RBC proteomics and metabolomics studies revealed the abundance of GPx4 to be correlated with lipid-anchored proteins. In addition, GPx4 anti-correlated with lyso-phospholipids and complement system proteins, further supporting the presence of active GPx4 in mature RBCs. To test the potential biological relevance of GPx4 in mature RBCs, we correlated the rate of hemolysis of human RBCs during storage with the abundance of GPx4 and other heritable RBC proteins. Of the molecules that anti-correlated with the rate of hemolysis of RBCs, proteins that mediate the cellular response to hydroperoxides, including GPx4, have the greatest enrichment. Western blotting further confirmed the presence of GPx4 antigenic protein in RBCs. Using an assay optimized to measure the activity of GPx4 in RBCs, we found GPx4 to be an active enzyme in mature RBCs, suggesting that GPx4 protects RBCs from hemolysis during blood bank storage.
