Peroxiredoxin 2, glutathione peroxidase, and catalase in the cytosol and membrane of erythrocytes under H₂O₂-induced oxidative stress

Abstract

Erythrocytes are continuously exposed to risk of oxidative injury due to oxidant oxygen species. To prevent damage, they have antioxidant agents namely, catalase (Cat), glutathione peroxidase (GPx), and peroxiredoxin 2 (Prx2). Our aim was to contribute to a better understanding of the interplay between Prx2, Cat, and GPx under H2O2-induced oxidative stress, by studying their changes in the red blood cell cytosol and membrane, in different conditions. These three enzymes were quantified by immunoblotting. Malondialdehyde, that is, lipoperoxidation (LPO) in the erythrocyte membrane, and membrane-bound hemoglobin (MBH) were evaluated, as markers of oxidative stress. We also studied the erythrocyte membrane protein profile, to estimate how oxidative stress affects the membrane protein structure. We showed that under increasing H2O2 concentrations, inhibition of the three enzymes with or without metHb formation lead to the binding of Prx2 and GPx (but not Cat) to the erythrocyte membrane. Prx2 was detected mainly in its oxidized form and the linkage of metHb to the membrane seems to compete with the binding of Prx2. Catalase played a major role in protecting erythrocytes from high exogenous flux of H2O2, since whenever Cat was active there were no significant changes in any of the studied parameters. When only Cat was inhibited, Prx2 and GPx were unable to prevent H2O2-induced oxidative stress resulting in increasing MBH and membrane LPO. Additionally, the inhibition of one or more of these enzymes induced changes in the anchor/linker proteins of the junctional complexes of the membrane cytoskeleton-lipid bilayer, which might lead to membrane destabilization.

LncRNA ACART protects cardiomyocytes from apoptosis by activating PPAR‐γ/Bcl‐2 pathway

“…It cannot penetrate the cell membrane under physiological conditions; however, when cell membrane is damaged, LDH leaks from the intracellular substance to the extracellular matrix or culture supernatant . H 2 O 2 ‐induced oxidative stress results in membrane lipoperoxidation and membrane destabilization leading to cell membrane permeability increased . Therefore, when cardiomyocytes are stimulated by H 2 O 2 to induce cell damage, the release of LDH to the culture supernatant is increased.…”

Interplay between Erythrocyte Peroxidases and Membrane

“…Clustering of band 3 as a result of enhanced metHb formation and linkage to the membrane has been reported in several erythrocyte disorders such as, hereditary spherocytosis [26], beta-thalassemia [27], sickle cell anemia [28] and glucose-6-phosphate dehydrogenase deficiency [29]. An increase in metHb levels and in its linkage to the RBC membrane, accompanied by ROS formation, was also found in stored RBCs for blood transfusion [30] and in exogenous H 2 O 2 -induced OS upon healthy erythrocytes [31,32]. Hb oxidation also occurs as a natural process, resulting from RBC aging [33], that is associated with metabolic degradation due to reduction in enzyme activity.…”

“…When compared with the other H 2 O 2 scavenger enzymes, CAT seems to be the key enzyme to remove high intracellular concentrations of H 2 O 2 [32,53,59,60]. Moreover, CAT is highly specific for its substrate, H 2 O 2 , and it is not able to eliminate organic peroxides, unlike other peroxidases [59].…”

“…As part of the erythrocyte antioxidant system, Prx2 is responsible for the removal of low H 2 O 2 concentrations, since the Trx system has a limited capacity for Prx2 regeneration into its reduced active form [32,59,60,73]. Recently, it was found that Prx2 can have a dual function according to H 2 O 2 levels, as an antioxidant enzyme or as a chaperone, due to changes in its structure [59,73,78].…”

Antifatigue and antiaging effects of Chinese rice wine in mice

“…For dealing with reactive byproducts of the metabolic process, higher eukaryotes have developed antioxidatant defense strategies, including enzymatic systems, such as CAT and GSH‐Px, to protect cells from oxidative damages (Rocha, Gomes, Lima, Bronze‐da‐Rocha, & Santos‐Silva, 2015; Sin et al., 2013). CAT occurs in almost all biological cells, while GSH‐Px is especially important for brain.…”