ERYTHROCYTE AGING IS ASSOCIATED WITH CHANGES IN BAND 3 PROTEIN FUNCTION DUE TO OXIDATIVE STRESS AND GLYCATION EVENTS

Aging is described as a multi-factorial process developing through a complex net of interactions between biological and molecular mechanisms, and involves oxidative stress as well as glycation. The aim of the present work focuses on the role of Band 3 protein (B3p) activity, an anion exchanger essential to erythrocytes homeostasis, in a D-galactose (D-Gal)-induced aging model. Anion exchange capability, measured by the rate constant of SO4² uptake through B3p, TBARS levels -a marker of lipid peroxidation-, total sulfhydryl (SH) groups, methaemoglobin (MetHb) and glycated haemoglobin (Hb) levels, and GSH/GSSG ratio were determined following to exposure of human erythrocytes to different concentrations of D-Gal for 24 hours. Our results show that: i) the rate constant for SO4² uptake is accelerated; ii) TBARS and glycated Hb levels are increased; iii) total -SH groups and GSH/GSSG ratio are decreased. Conversely, MetHb levels did not change compared to control conditions. In conclusion, these findings confirm that D-Gal exposure induces aging in human erythrocytes, altering B3p function, Hb and the antioxidant system. Further studies are needed to understand whether supplementation with antioxidant substances, namely quercetin, can restore the altered parameters.