Unraveling DEHP influence on hemoglobin S polymerization in sickle cell disease: Ex vivo, in vitro and in silico analysis

• Published in: Toxicology in vitro 2024-06, Vol.98, p.105832-105832, Article 105832
• Main Authors: Camacho, Rodrigo Abreu, Machado, Aghata Vitoria, de Oliveira Mendonça, Fernanda, Teixeira-Alves, Lyzes Rosa, Guimarães-Nobre, Camila Cristina, Mendonça-Reis, Evelyn, da Silva, Priscila Ferreira, Cardim-Pires, Thyago R., Miranda-Alves, Leandro, Berto-Junior, Clemilson
• Format: Article
• Language: English
• Subjects: Anemia, Sickle Cell - genetics; Anemia, Sickle Cell - metabolism; Computer Simulation; DEHP; Diethylhexyl Phthalate - toxicity; Erythrocyte; Erythrocytes - drug effects; Erythrocytes - metabolism; Hemoglobin; Hemoglobin, Sickle - genetics; Hemoglobin, Sickle - metabolism; Humans; Polymerization; Sickle cell disease
• ISSN: 0887-2333; 1879-3177
• DOI: 10.1016/j.tiv.2024.105832

Sickle cell disease (SCD) is a hereditary hemoglobinopathy, caused by a mutation at position 6 of the β-globin chain and patients are frequently exposed to several blood transfusions in order to maintain physiological function. Transfusion blood bags are composed of PVC and phthalates (as DEHP) are often introduced to the material in order to confer malleability. In this sense, DEHP can easily elute to the blood and cause harmful effects. This study aimed to unravel DEHP effect on SCD patient's hemoglobin function. We found that HbS polymerization using whole erythrocytes is decreased by DEHP in ex vivo experiments and this effect might be mediated by the DEHP-VAL6 interaction, evaluated in silico. Isolated HbS exhibited less polymerization at low DEHP concentrations and increased polymerization rate at higher concentration. When analyzing the propensity to aggregate, HbS is more inclined to aggregate when compared to HbA due to the residue 6 mutation. Circular dichroism showed characteristic hemoglobin peaks for oxygenated HbS that are lost when oxygen is sequestered, and DEHP at higher concentration mildly recovers a peak close to the second hemoglobin one. Finally, by transmission electron microscopy we demonstrated that high DEHP concentration increased polymer formation with a more organized structure. These findings show for the first-time the beneficial effect of low-dose DEHP on HbS polymerization. [Display omitted] •Hemoglobin S has a higher propensity to aggregate then HbA.•DEHP at low dose decrease HbS polymerization and increase at high doses of DEHP.•DEHP-VAL6 interaction prevents HbS polymerization in silico.