title: Adhesion of sickle red blood cells and damage to interleukin-1 beta stimulated endothelial cells under flow in vitro.
abstract: Two factors that are hypothesized to contribute to vasoocclusive crises in sickle cell anemia are increased sickle red blood cell-endothelial cell interactions and damage to endothelium. Despite considerable study, the mechanisms by which erythrocyte-endothelial interactions occur and the role of endothelial damage have not yet been fully elucidated. In this report, we demonstrate that adhesion and damage may be related in a model of vasoocclusion in sickle cell anemia. Phase contrast microscopy coupled to digital image processing was used to determine the adhesion of sickle red blood cells to 1-, 4-, and 24-hour interleukin-I beta (IL-1 beta) stimulated endothelial calls in a parallel plate flow chamber. Morphological alterations to activated endothelial cells after the perfusion of sickle erythrocytes were also identified. Pretreatment of monolayers with 50 pg/mL of IL-1 beta for 1, 4, and 24 hours caused approximately 16-fold increases in adhesion of sickle cells to activated endothelium at all time points. Results with an Arginine-glycine aspartic acid (RGD) peptide and monoclonal antibodies indicated a role for three different endothelial cell receptors: alpha v beta 3 after 1 hour of IL-1 beta stimulation; E-selectin after 4 hours of IL-1 beta stimulation; and vascular cell adhesion molecule-1 after prolonged exposure to cytokines. Perfusion of sickle, but not normal, erythrocytes resulted in alteration of endothelial morphology. Approximately 6% to 8% damage was observed on 4- and 24-hour IL-1 beta stimulated endothelial cells after the perfusion of sickle cells. Damage to 24-hour activated endothelial cells showed a positive correlation (r = .899) with the number of adherent sickle erythrocytes.
authors.affiliation: Cox Laboratory for Biomedical Engineering, Rice University, Houston, TX 77251-1892, USA.
authors.forename: M
authors.initials: M
authors.lastname: Natarajan
authors.forename: M M
authors.initials: MM
authors.lastname: Udden
authors.forename: L V
authors.initials: LV
authors.lastname: McIntire
mesh_terms: D000595:Amino Acid Sequence; D000755:Anemia, Sickle Cell / Q000097:blood*; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods; D002478:Cells, Cultured; D019040:E-Selectin / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects; D004913:Erythrocytes, Abnormal / Q000473:pathology*; D005353:Fibronectins / Q000737:chemistry; D005434:Flow Cytometry; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007375:Interleukin-1 / Q000494:pharmacology*; D008858:Microscopy, Phase-Contrast; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism; D010446:Peptide Fragments / Q000494:pharmacology; D010477:Perfusion; D019030:Receptors, Vitronectin / Q000502:physiology; D012212:Rheology; D013997:Time Factors; D014471:Umbilical Veins; D019010:Vascular Cell Adhesion Molecule-1 / Q000502:physiology
chemical_list: D019040:E-Selectin; D005353:Fibronectins; D007375:Interleukin-1; D009842:Oligopeptides; D010446:Peptide Fragments; D019030:Receptors, Vitronectin; D019010:Vascular Cell Adhesion Molecule-1; C047981:arginyl-glycyl-aspartic acid