Oxidative Damage In Red Blood Cells Research Articles

ROS formation, mitochondrial potential and osmotic stability of the lamprey red blood cells: effect of adrenergic stimulation and hypoosmotic stress.

Semi-anadromous animals experience salinity fluctuations during their life-span period. Alterations of environmental conditions induce stress response where catecholamines (CA) play a central role. Physiological stress and changes in external and internal osmolarity are frequently associated with increased production of reactive oxygen species (ROS). In this work, we studied the involvement of the cAMP/PKA pathway in mediating catecholamine-dependent effects on osmoregulatory responses, intracellular production of ROS, and mitochondrial membrane potential of the river lamprey (Lampetra fluviatilis, Linnaeus, 1758) red blood cells (RBCs). We also investigated the role of hypoosmotic shock in the process of ROS production and mitochondrial respiration of RBCs. For this, osmotic stability and the dynamics of the regulatory volume decrease (RVD) following hypoosmotic swelling, intracellular ROS levels, and changes in mitochondrial membrane potential were assessed in RBCs treated with epinephrine (Epi, 25 μM) and forskolin (Forsk, 20 μM). Epi and Forsk markedly reduced the osmotic stability of the lamprey RBCs whereas did not affect the dynamics of the RVD response in a hypoosmotic environment. Activation of PKA with Epi and Forsk increased ROS levels and decreased mitochondrial membrane potential of the lamprey RBCs. In contrast, upon hypoosmotic shock enhanced ROS production in RBCs was accompanied by increased mitochondrial membrane potential. Overall, a decrease in RBC osmotic stability and the enhancement of ROS formation induced by β-adrenergic stimulation raises concerns about stress-associated changes in RBC functions in agnathans. Increased ROS production in RBCs under hypoosmotic shock indicates that a decrease in blood osmolarity may be associated with oxidative damage of RBCs during lamprey migration.

An Ex Vivo Model of Oxidatively Stressed Red Blood Cells Demonstrates a Role for Exogenous Amino Acids in Enhancing Red Blood Cell Function and Morphology

The capacity of mature red blood cells (RBCs) to respond to oxidative stress is limited due to lack of a full complement of organelles and as such, when faced with an oxidative environment, they rely on their endogenous antioxidant capacity (including superoxide dismutase, catalase, peroxiredoxin and glutathione) to protect against cellular damage. Low blood glutathione activity has been reported in several red cell disorders leading to increased oxidative stress. Targeting oxidative stress has thus been proposed as a secondary treatment in multiple anemia-causing diseases, such as sickle cell disease (SCD) and malaria, although its overall efficacy remains unclear. As glutathione itself is not permeable through the RBC membrane, treatment with cell-permeable amino acid precursors of glutathione (glutamine, cysteine and/or glycine) is a potential strategy to expand the RBC's antioxidant capacity and alleviate oxidative stress. Indeed, L-glutamine has recently been approved as a therapeutic for SCD, although the mechanistic basis for its effect is not clear. To fill this gap in our understanding, we performed detailed characterization of biophysical phenotype, morphology, and intracellular redox environment of oxidatively stressed RBCs in environments with varying amounts of available precursor amino acids.To assess the impact of exogenous amino acid precursors on the RBC's glutathione antioxidant capacity, we exposed mature RBCs from healthy adults to hydrogen peroxide (H 2O 2) and co-incubated with media that included glutamine, cysteine, and/or glycine. As catalase has the ability to scavenge high levels of exogenously fluxed H 2O 2, we performed these experiments using sodium azide to block catalase activity, enabling us to model oxidatively stressed RBCs. We performed osmotic gradient ektacytometry to quantify RBC deformability and hydration status, and assessed RBC morphology using osmotic-adjusted fixation techniques and scanning electron microscopy. As previously documented, H 2O 2 exposure in sodium azide-treated healthy RBCs was associated with decreased deformability, decreased hydration and increased numbers of echinocytes in a dose-dependent manner. We monitored red cell phenotypic changes following co-incubation with glutamine, cysteine, and/or glycine individually and in combination to test whether these amino acids extended the RBC's antioxidant abilities and contributed to improved function and morphology. We found that supplementation with all three amino acids in combination significantly improved both deformability and hydration of H 2O 2-stressed RBCs, as opposed to treatment with glutamine alone. To directly assess whether the exogenous amino acids were in fact contributing to less intracellular oxidative stress in RBCs, we quantified intracellular reactive oxygen species (ROS) using 2‘, 7‘ -dichlorofluorescein diacetate (DCFDA), a cell permeable dye used to measure ROS production. As expected, H 2O 2 exposure alone was associated with elevated intracellular ROS inside RBCs in both a time- and dose-dependent manner. Supplementation with the three amino acid cocktail during H 2O 2 stress resulted in a reduction in the level of intracellular ROS activity.In summary, we documented that exogenous added amino acids reduce oxidative damage in RBCs and we hypothesize that this protection occurs via the glutathione antioxidant pathways. In future studies, we plan to investigate the impact of exogenous amino acids on sickled and irreversibly sickled RBCs (ISCs) in the context of SCD, and on uninfected and infected RBCs in the context of malaria. DisclosuresKim-Shapiro: Beverage Operations LLC: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: co-inventor on a patent related to the use of nitrite under cardiovascular conditions, and a co-author on patents related to treatment of hemolysis.

The influence of oxidative bursts of phagocytes on red blood cell oxidation in anemic cattle infected with Theileria sergenti

The primary clinical symptom of Japanese bovine theileriosis, caused by the intraerythrocytic protozoan Theileria sergenti, is anemia, but the underlying mechanism of this anemia remains unknown. To elucidate the pathogenesis of anemia developing in bovine theileriosis, we investigated the relationship between oxidative bursts of peripheral blood phagocytes (neutrophils and monocytes) and the oxidation of red blood cells (RBC) to the development of anemia in cattle experimentally infected with T. sergenti. The levels of methemoglobin (MetHb) and malondialdehyde (MDA), as a parameter of intracellular and membrane oxidative damage in RBC and of production of hydrogen peroxide (H2O2) in phagocytes, were low before the onset of anemia; these parameters began to increase remarkably with decreasing packed cell volume and increasing parasitemia during the course of the anemia, which returned to initial levels during convalescence from anemia. A positive correlation between H2O2 production of phagocytes and each of the oxidative indices of MetHb and MDA was also noted during the onset of anemia. The levels of antioxidants, namely reduced glutathione and glucose-6-phosphate dehydrogenase, in RBC also decreased during the progression of anemia. These results suggest that oxidative damage of RBC has a close relationship with the onset of anemia in bovine theileriosis, and that oxidative bursts of phagocytes may play a part in the pathogenesis of anemia in infected cattle.

Evidence for accumulation of lipid hydroperoxides during the aging of human red blood cells in the circulation.

Young and old human red blood cells (RBC) were separated from freshly collected human blood by Percoll density gradient centrifugation. The amounts of lipid peroxidation products in the lipid fractions of these RBC were determined by high performance liquid chromatography-chemiluminescence, thiobarbituric acid and LPO-586 methods. The levels of phosphatidylcholine and phosphatidylethanolamine hydroperoxides in old RBC were higher than in young RBC. The products reflecting the advanced stage of lipid peroxidation, malonaldehyde (free and bound forms), 4-hydroxyalkenals (free and bound forms) and other aldehydes, were also higher in old RBC than in young RBC. The levels of these lipid peroxidation products increased when whole RBC were mildly oxidized with ferric ion. These results indicate that oxidative damage of RBC in the circulation takes place during the aging process, and lipid hydroperoxides and other lipid peroxidation products accumulate in old RBC.

Quantitative relationship between Heinz body formation and red blood cell deformability [see comments

The ultimate cause of destruction of red blood cells (RBCs) after oxidative damage with Heinz body formation is not well understood. We correlated the changes in RBC morphology and membrane protein composition after oxidant treatment with the alterations in deformability of whole cells and cell membranes. The incubation of RBCs with phenylhydrazine concentrations of 0.3 to 100 mg/dL at 37 degrees C for one hour led to a dose-dependent formation of Heinz bodies, ranging from isolated Heinz bodies at 1 mg/dL to a confluent coating of the inner membrane surface at 100 mg/dL phenylhydrazine. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of a large quantity of hemoglobin bound to the ghost membrane of treated RBCs. Electrophoresis with and without dithiothreitol indicated that disulfide bridges are abundant between hemoglobin molecules and are also present among membrane proteins but are not the major bond between hemoglobin and membrane. Changes of spectrin, ankyrin, band 3, and band 6 and the appearance of a 260,000-dalton complex were also observed. With phenylhydrazine concentrations below 30 mg/dL, even in the presence of multiple Heinz bodies, the RBC deformability measured by filtration through 2.6-, 4.5-, and 6.8-microns pores and the membrane deformability determined by a filter aspiration technique were not altered. With 100 mg/dL phenylhydrazine, when the entire membrane was coated with Heinz bodies, RBC filterability and membrane deformability were drastically reduced. These results indicate that oxidative damage of RBCs with discrete Heinz body formation causes focal membrane rigidification but does not affect the global cellular deformability until the Heinz bodies nearly cover the entire cell endoface.

Quantitative Relationship Between Heinz Body Formation and Red Blood Cell Deformability

Abstract The ultimate cause of destruction of red blood cells (RBCs) after oxidative damage with Heinz body formation is not well understood. We correlated the changes in RBC morphology and membrane protein composition after oxidant treatment with the alterations in deformability of whole cells and cell membranes. The incubation of RBCs with phenylhydrazine concentrations of 0.3 to 100 mg/dL at 37 degrees C for one hour led to a dose-dependent formation of Heinz bodies, ranging from isolated Heinz bodies at 1 mg/dL to a confluent coating of the inner membrane surface at 100 mg/dL phenylhydrazine. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of a large quantity of hemoglobin bound to the ghost membrane of treated RBCs. Electrophoresis with and without dithiothreitol indicated that disulfide bridges are abundant between hemoglobin molecules and are also present among membrane proteins but are not the major bond between hemoglobin and membrane. Changes of spectrin, ankyrin, band 3, and band 6 and the appearance of a 260,000-dalton complex were also observed. With phenylhydrazine concentrations below 30 mg/dL, even in the presence of multiple Heinz bodies, the RBC deformability measured by filtration through 2.6-, 4.5-, and 6.8-microns pores and the membrane deformability determined by a filter aspiration technique were not altered. With 100 mg/dL phenylhydrazine, when the entire membrane was coated with Heinz bodies, RBC filterability and membrane deformability were drastically reduced. These results indicate that oxidative damage of RBCs with discrete Heinz body formation causes focal membrane rigidification but does not affect the global cellular deformability until the Heinz bodies nearly cover the entire cell endoface.