Article

Erythrocyte vesiculation: a self-protective mechanism?

Department of Clinical Chemistry, Rijnstate Hospital, Arnhem, The Netherlands.
British Journal of Haematology (impact factor: 4.94). 06/2008; 141(4):549-56. DOI:10.1111/j.1365-2141.2008.07055.x pp.549-56
Source: PubMed

ABSTRACT Previous studies demonstrated that 20% of haemoglobin is lost from circulating erythrocytes during their total lifespan by vesiculation. To study whether removal molecules other than membrane-bound haemoglobin were present in erythrocyte-derived vesicles, flow cytometry and immunoblot analysis were employed to examine the presence of phosphatidylserine (PS) and IgG, and senescent cell antigens respectively. It was demonstrated that 67% of glycophorin A-positive vesicles exposed PS, and that half of these vesicles also contained IgG. Immunoblot analysis revealed the presence of a breakdown product of band 3 that reacted with antibodies directed against senescent erythrocyte antigen-associated band 3 sequences. In contrast, only the oldest erythrocytes contained senescent cell antigens and IgG, and only 0.1% of erythrocytes, of all ages, exposed PS. It was concluded that vesiculation constitutes a mechanism for the removal of erythrocyte membrane patches containing removal molecules, thereby postponing the untimely elimination of otherwise healthy erythrocytes. Consequently, these same removal molecules mediate the rapid removal of erythrocyte-derived vesicles from the circulation.

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Keywords

ages
 
band 3
 
breakdown product
 
erythrocyte membrane patches
 
erythrocyte-derived vesicles
 
erythrocytes
 
healthy erythrocytes
 
immunoblot analysis
 
membrane-bound haemoglobin
 
oldest erythrocytes
 
Previous studies
 
PS
 
rapid removal
 
removal molecules
 
senescent cell antigens
 
senescent erythrocyte antigen-associated band 3 sequences
 
total lifespan
 
untimely elimination
 
vesiculation