A microfluidic approach to study the effect of mechanical stress on erythrocytes in sickle cell disease

Abstract

The human red blood cell is a biconcave disc of 6-8 × 2 μm that is highly elastic. This capacity to deform enables it to stretch while circulating through narrow capillaries to ensure its main function of gas exchange. Red cell shape and deformability are altered in membrane disorders because of defects in skeletal or membrane proteins affecting protein-protein interactions. Red cell properties are also altered in other pathologies such as sickle cell disease. Sickle cell disease is a genetic hereditary disorder caused by a single point mutation in the β-globin gene generating sickle haemoglobin (HbS). Hypoxia drives HbS polymerisation that is responsible for red cell sickling and reduced deformability. The main clinical features of sickle cell disease are vaso-occlusive crises and haemolytic anaemia. Foetal haemoglobin (HbF) inhibits HbS polymerisation and positively impacts red cell survival in the circulation but the mechanism through which it exerts this action is not fully characterized. In this study, we designed a microfluidic biochip mimicking the dimensions of human capillaries to measure the impact of repeated mechanical stress on the survival of red cells at the single cell scale under controlled pressure. We show that mechanical stress is a critical parameter underlying intravascular haemolysis in sickle cell disease and that high intracellular levels of HbF protect against lysis. The biochip is a promising tool to address red cell deformability in pathological situations and to screen for molecules positively impacting this parameter in order to improve red cell survival in the circulation.

Numerical Model for the Determination of Erythrocyte Mechanical Properties and Wall Shear Stress in vivo From Intravital Microscopy

“…Molecular techniques, namely atomic force microscopy and optical tweezers, allow for increased spatial resolution by determining spatial maps of stress along the RBC membrane (Fedosov et al, 2014). Recently, microfluidic devices have been developed for probing the mechanical properties of RBCs and the effects of mechanical stress on RBCs in hematologic conditions, namely sickle cell disease (Iragorri et al, 2018;Ye et al, 2019). The mechanical properties and the strain energy function for the RBC membrane have been defined for a two-dimensional membrane with variable membrane thickness, physiologically dependent on the density of glycoproteins and transporters at any one given section of the RBC membrane (Skalak and Chien, 1982).…”

New insights into red cell rheology and adhesion in patients with sickle cell anaemia during vaso‐occlusive crises

“…Two μl of packed RBC were suspended in 200 μl of ID‐CellStab (Biorad, Hercules, CA, USA) and 50 000 events were acquired using an Imagestream ISX MkII flow cytometer (Amnis Corp, EMD Millipore, Seattle, WA, USA). ISCs were quantified using the IDEAS software (version 6.2; Amnis Corp, EMD Millipore) as recently described (Lizarralde Iragorri et al , ). Results are presented as median and IQR.…”

Early Career Scientists’ Guide to the Red Blood Cell – Don’t Panic!

“…Technologies use stem cells for production and manipulation of red blood cells ( Hansen et al, 2019 ). We may follow red blood cells running through the blood vessels of living hosts ( Hertz et al, 2019 ; Slovinski et al, 2019 ) and model and evaluate responses of red blood cells to mechanical shear forces – the ones they are exposed to in our microvasculature ( Lizarralde Iragorri et al, 2018 ; Moura et al, 2019 ). We can detect electric currents that ions mediate passing through red blood cell membranes in hundreds of individual cells at the same time ( Rotordam et al, 2019 ).…”