The how, when, and why of the aging signals appearing on the human erythrocyte membrane: an atomic force microscopy study of surface roughness

We recently developed an atomic force microscopy–based protocol to use the roughness of the plasma membrane of erythrocytes (red blood cells, RBCs) as a morphological parameter, independently from the cell shape, to investigate the membrane-skeleton integrity in healthy and pathological cells. Here we apply the method to investigate a complex physiological phenomenon, the RBCs aging, that plays a major role in the regulation of the RBCs' turnover. The aging, monitored morphologically and biochemically, has been accelerated and modulated by preventing oxidative stresses as well as the effects of proteases and divalent cations, and by artificially consuming the intracellular adenosine triphosphate. The collected data evidence that the progression of aging causes a drastic decrease of the measured roughness that is diagnostic of a progressive, adenosine triphosphate–dependent alteration of the membrane-skeleton properties. Finally, the degree of reversibility of such effects has been investigated as a function of aging time, enabling the detection of irreversible transformation in the RBCs' structure and metabolism.From the Clinical EditorAn Atomic Force Microscopy-based protocol that uses the roughness of plasma membrane of erythrocytes as a morphological parameter to investigate membrane-skeleton integrity was applied to investigate red blood cell aging. The authors demonstrate that aging causes a decrease of the measured roughness, correlating with a progressive, ATP-dependent alteration of membrane-skeleton properties.

Graphical AbstractTrend of the mean roughness value of the RBCs plasma membrane shown as function of the aging time measured in starvation conditions. A progressive decrease of the membrane roughness, which is sensitive to the aggregation of the membrane-skeleton, runs parallel to the occurrence and evolution of microscopic aging markers on the plasma membrane of RBCs shown in the insets A to E.Figure optionsDownload high-quality image (74 K)Download as PowerPoint slide