Oxidative Stress Increases Erythrocyte Sensitivity to Shear-Mediated Damage

Area of Science:

• Biomedical Engineering
• Hematology
• Cellular Mechanics

Background:

• Mechanical circulatory support (MCS) patients experience inflammation and free radical production.
• Blood interactions with artificial surfaces in MCS exacerbate oxidative stress.

Purpose of the Study:

• To investigate the impact of oxygen free radicals on red blood cell (RBC) deformability.
• To determine the susceptibility of free radical-exposed RBCs to mechanical forces.

Main Methods:

• Red blood cells (RBCs) from healthy donors were incubated with phenazine methosulfate (PMS) to generate superoxide radicals.
• Ektacytometry assessed RBC deformability and mechanical damage susceptibility before and after exposure to various shear stress conditions.
• Compared mechanical properties of PMS-treated RBCs against control groups.

Main Results:

• PMS incubation significantly impaired RBC deformability by approximately 19% under all conditions.
• Free radicals reduced the ability of RBCs to deform.
• RBCs retained their mechanical response to shear stress, but at a reduced level compared to controls.

Conclusions:

• Oxygen free radicals negatively impact RBC mechanics, reducing deformability.
• While RBCs adapt to shear stress, their mechanical resilience is compromised by free radicals.
• Minimizing high shear stress is crucial for MCS patients with elevated free radical exposure to prevent further RBC damage.