In vitro effects of high glucose concentrations on membrane protein oxidation, G‐actin and deformability of human erythrocytes

Abstract

The object of this study was to examine the effect of elevated in vitro glucose concentrations on protein modification and functional changes in human erythrocytes. Groups were exposed to 5-45 mM glucose concentrations. The time effect of any changes was also evaluated. In erythrocyte ghosts, protein glycation and oxidation were evaluated using spectrophotometric methods. G-actin was measured by a DNase I inhibition assay in cell lysates. Erythrocyte deformability was assessed using a cell transit analyser. At 24 h, a significant protein oxidation (at 25 and 45 mM glucose; p < 0.05), and G-actin increase was observed for all concentrations (p < 0.05). At 48 h, a significant increase in glycation (25 and 45 mM glucose; p < 0.05), protein oxidation (p < 0.05), and G-actin (p < 0.05) was observed in all groups. A significant positive correlation was observed between glucose /protein oxidation, glucose/G-actin and protein oxidation/G-actin at 24 and 48 h. Our findings show that the oxidative effect of glucose on erythrocytes depends on concentration and incubation time. We also present the first evidence of increased G-actin in human erythrocytes exposed to high glucose concentrations as a diabetes model.

Less known pathophysiological mechanisms of anemia in patients with diabetic nephropathy

“…Impaired activity of the Na+/K+-ATPase pump which leads to RBC swelling [88] together with protein oxidation and accumulation of AGEs on the RBC cell membrane are the main mechanisms responsible for erythrocyte dysfunction [91,92], thus leading to shortened RBC lifespan [93,94]. In addition, hyperglycemia promotes the expression of aminophospholipids such as phosphatidylserine on the surface of RBC, which results in their recognition and trapping by the reticuloendothelial system [92].…”

Deep Coverage Mouse Red Blood Cell Proteome

“…Actin cytoplasmic 2 (␥-actin) appears to be a mouse, but not human, mature RBC protein. Increased ␥-actin in human RBCs (induced by high circulating glucose levels) may pathologically reduce RBC deformability (65). Glucose effects on mouse RBC may consequently differ from human RBC.…”

Non-transferrin-bound iron is associated with biomarkers of oxidative stress, inflammation and endothelial dysfunction in type 2 diabetes

“…Protein glycation may in turn lead to the formation of reactive oxygen species (Resmi et al 2005). These changes may predispose patients with type 2 diabetes to an enhanced tendency towards intravascular haemolysis.…”