Remigante Alessia, Morabito Rossana, Spinelli Sara, Trichilo Vincenzo, Loddo Saverio, Sarikas Antonio, Dossena Silvia, Marino Angela
Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno D'Alcontres 31, 98166 Messina, Italy.
Department of Clinical and Experimental Medicine, AOU Policlinico Universitario "G. Martino", Via Consolare Valeria, 98125 Messina, Italy.
Antioxidants (Basel). 2020 Aug 2;9(8):689. doi: 10.3390/antiox9080689.
d-Galactose (d-Gal), when abnormally accumulated in the plasma, results in oxidative stress production, and may alter the homeostasis of erythrocytes, which are particularly exposed to oxidants driven by the blood stream. In the present investigation, the effect of d-Gal (0.1 and 10 mM, for 3 and 24 h incubation), known to induce oxidative stress, has been assayed on human erythrocytes by determining the rate constant of SO uptake through the anion exchanger Band 3 protein (B3p), essential to erythrocytes homeostasis. Moreover, lipid peroxidation, membrane sulfhydryl groups oxidation, glycated hemoglobin (% A1c), methemoglobin levels (% MetHb), and expression levels of B3p have been verified. Our results show that d-Gal reduces anion exchange capability of B3p, involving neither lipid peroxidation, nor oxidation of sulfhydryl membrane groups, nor MetHb formation, nor altered expression levels of B3p. d-Gal-induced %A1c, known to crosslink with B3p, could be responsible for rate of anion exchange alteration. The present findings confirm that erythrocytes are a suitable model to study the impact of high sugar concentrations on cell homeostasis; show the first in vitro effect of d-Gal on B3p, contributing to the understanding of mechanisms underlying an in vitro model of aging; demonstrate that the first impact of d-Gal on B3p is mediated by early Hb glycation, rather than by oxidative stress, which may be involved on a later stage, possibly adding more knowledge about the consequences of d-Gal accumulation.
d-半乳糖（d-Gal）在血浆中异常蓄积时，会导致氧化应激产生，并可能改变红细胞的内环境稳定，而红细胞特别容易受到血流驱动的氧化剂的影响。在本研究中，已知可诱导氧化应激的d-Gal（0.1和10 mM，孵育3小时和24小时）对人红细胞的影响，已通过测定通过阴离子交换蛋白带3（B3p）摄取SO的速率常数来进行检测，B3p对红细胞内环境稳定至关重要。此外，还检测了脂质过氧化、膜巯基氧化、糖化血红蛋白（% A1c）、高铁血红蛋白水平（% MetHb）以及B3p的表达水平。我们的结果表明，d-Gal降低了B3p的阴离子交换能力，这既不涉及脂质过氧化，也不涉及膜巯基的氧化、MetHb的形成，也不涉及B3p表达水平的改变。已知与B3p交联的d-Gal诱导的%A1c可能是阴离子交换速率改变的原因。本研究结果证实，红细胞是研究高糖浓度对细胞内环境稳定影响的合适模型；显示了d-Gal对B3p的首次体外作用，有助于理解体外衰老模型的潜在机制；证明d-Gal对B3p的首次作用是由早期血红蛋白糖基化介导的，而不是由氧化应激介导的，氧化应激可能在后期起作用，这可能会增加对d-Gal蓄积后果的更多了解。
