The Anti-Sickling Agent Aes-103 Decreases Sickle Erythrocyte Fragility, Hypoxia-Induced Sickling and Hemolysis In Vitro

• Published in: Blood 2013-11, Vol.122 (21), p.940-940
• Main Authors: Mendelsohn, Laurel G., Pedoeim, Leah, Wang, Yekai Kevin, Saiyed, Rehan, Brantner, Christine A., Daniels, Mathew P., Nichols, James S., Wang, Xunde, van Beers, Eduard J., Kato, Gregory J.
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V122.21.940.940

The polymerization of hemoglobin S results in red cell morphological changes and fragility, which promotes hemolysis. Aes-103 (5-hydroxymethylfurfural, 5-HMF) is a clinical-stage candidate anti-sickling agent that binds to alpha subunits of hemoglobin, increases its oxygen affinity and stabilizes the R-state. In vitro at, millimolar levels, it inhibits hypoxia-induced sickling and in vivo protects sickle cell mice against hypoxia-induced death. We have found in vitro that Aes-103 increases oxygen affinity of red cells from healthy control subjects and from patients with sickle cell disease either on or off hydroxyurea. We further investigated the ability of Aes-103 to protect red cells from patients with sickle cell anemia from a variety of effects of sickling. First, we used transmission electron microscopy (TEM) to investigate fiber formation in human sickle blood incubated with 5 mM Aes-103 for one hour at 37° prior to deoxygenation (2% oxygen for two hours) and fixed with glutaraldehyde, and embedded by standard techniques. Semi-quantitative analysis of the images showed that the addition of Aes-103 was able to significantly reduce the percentage of cells displaying elongated fibers (p=0.048). Furthermore, we confirmed that Aes-103 incubation prior to hypoxia also reduces morphological sickling as quantified by sickle imaging flow cytometry (P=0.0027). Fiber formation was associated with morphological sickling (R=0.522, P=0.027). Second, we investigated the effects of Aes-103 on sickle erythrocyte fragility. In vitro shear stress induced by rotation on a vertical rotator at 21 revolutions per minute for 3 hours promoted hemolysis in blood samples from patients with SCA (free hemoglobin 29.4 ± 3.4 vs. 8.4 ± 0.9 mM, p