Scientists describe a novel mechanism responsible for blood vessel injury in Sickle Cell Disease (SCD): microparticles derived from sickle cells deliver heme to the vascular endothelial cells causing oxidative damage.
Sickle Cell Disease (SCD) is an inherited blood disorder caused by a single base mutation in the DNA of affected patients, producing abnormal hemoglobin molecules. In SCD, red blood cells (RBCs) that carry oxygen lose their flexibility and typical round shape, and become rigid with a distinctive “sickle” shape that make their passage through blood vessels more difficult. Millions of people worldwide suffer from SCD; this is also the most …show more content…
In particular, little is known about the process by which cell-free heme is presented to the endothelial cells.
A recent article published in Blood by a group led by Drs. Blanc-Brude and Camus at the Paris Center for Cardiovascular Research in France, has revealed that there are additional players that take part in the …show more content…
Heme-laden MPs transfer heme and iron to the endothelial cells of the lining, causing their death by oxidative damage. Because of the toxicity of cell-free heme and iron, nature has developed specialized systems that scavenge and remove these molecules from circulation, providing systemic protection against oxidative injury. Such systems comprise two molecules called haptoglobin (Hp) and hemopexin (Hpx). However, these mechanisms are overwhelmed in SCD because of the sizeable amounts of heme and iron that are released following RBC breakdown [Figure