Alpha 4 beta 1-integrin expression on sickle reticulocytes: vascular cell adhesion molecule-1-dependent binding to endothelium.
Important complications in sickle cell anemia occur secondary to vascular occlusion, which is postulated to be initiated by interactions of erythrocytes with vascular endothelial cells. In patients with sickle cell anemia, up to 25% of reticulocytes express the alpha 4 beta 1-integrin complex. Furthermore, erythrocytes from patients with sickle cell anemia bind to endothelial cells activated by tumor necrosis factor alpha via (TNF alpha) via interactions between erythrocyte alpha 4 beta 1 and endothelial cell vascular cell adhesion molecule-1 (VCAM-1). Thus, binding of alpha 4 beta 1-expressing reticulocytes to cytokine-activated endothelial cells may initiate vascular complications in sickle cell anemia and perhaps other hemolytic anemias during episodes of infection and inflammation.
Swerlick
R A
RA
Department of Dermatology, Emory University School of Medicine, Atlanta, GA 30322.
Eckman
J R
JR
Kumar
A
A
Jeitler
M
M
Wick
T M
TM
D000755:Anemia, Sickle Cell / Q000097:blood*; D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules / Q000494:pharmacology*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D039041:Integrin alpha4beta1; D016023:Integrins / Q000096:biosynthesis* / Q000378:metabolism; D012156:Reticulocytes / Q000378:metabolism*; D014471:Umbilical Veins; D019010:Vascular Cell Adhesion Molecule-1
D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D039041:Integrin alpha4beta1; D016023:Integrins; D019010:Vascular Cell Adhesion Molecule-1