Isoquercetin treatment of mouse sickled red blood cells shows a discernible deformability and sickling phenotype

IntroductionSickle cell disease is an inherited hemoglobinopathy with defective red cell deformability. The defective deformability promotes microvascular occlusion and subsequent vaso-occlusion in sickle cell disease patients. Previous studies have demonstrated that thiol isomerases, an endoplasmic reticulum-resident oxidoreductase that is released from vascular cells into the bloodstream, are present on red cell membrane and contribute to cellular dehydration and sickling. However, the role of membrane-bound thiol isomerases on sickled red blood cells is unclear. MethodsUsing red blood cells from Townes humanized sickle cell or non-sickled mice, we performed ektacytometry assay under shear using laser assisted optical rotational cell analyzer (LORRCA) to assess the effects of antagonizing thiol isomerases with isoquercetin and a functional blocking monoclonal antibody. The densitometric properties of sickled red blood cells in the presence of isoquercetin was also tested using magnetic levitation. ResultsThiol isomerase antagonism increased sickled red cell elongation, cellular dehydration and the diamagnetic signature compared to control treatment. ConclusionThiol isomerases may be involved in regulating sickled red blood cells mechanical properties through mechanisms that require further investigation.