Sickle erythrocytes: a pro-oxidant machine
Sickle erythrocytes are characterized by the presence of HbS, instead of the normal HbA. Upon deoxygenation within the microcirculation, HbS molecules alter their configuration, exposing some hydrophobic residues that rapidly associate with hydropho- bic regions of adjacent molecules in the aqueous cell compartment [42]. This process of self-assembly or polymerization/sickling generates rigid HbS fibers that distort and damage the RBC membrane and cytoskeleton and alter RBC biochemical properties. HbS polymerization is reversible; fibers “melt” as oxygen is taken up by the HbS and the normal discoid shape returns [