scholarly journals Integrin alpha 4 beta 1 and glycoprotein IV (CD36) are expressed on circulating reticulocytes in sickle cell anemia

Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3548-3555 ◽  
Author(s):  
CC Joneckis ◽  
RL Ackley ◽  
EP Orringer ◽  
EA Wayner ◽  
LV Parise

The abnormal adherence of red blood cells, especially circulating reticulocytes (erythrocyte precursors), to the endothelium is believed to contribute to vascular occlusion observed in patients with sickle cell disease. Although several plasma proteins including von Willebrand factor and fibronectin have been proposed to mediate this adhesion, the mechanism of sickle cell adhesion to the endothelium remains unknown. Using flow cytometry, we screened sickle red blood cells with monoclonal antibodies (MoAbs) against known adhesion receptors and detected integrin subunits alpha 4 and beta 1 and the nonintegrin glycoprotein IV on reticulocytes but not on erythrocytes. No reactivity was detected against integrin subunits alpha 2, alpha 3, alpha 5, alpha 6, alpha v, beta 2, beta 3, integrin alpha IIb beta 3, or the nonintegrin glycoprotein Ib. Immunoprecipitation of reticulocytes with either alpha 4- or beta 1-specific antibodies identified the alpha 4 beta 1 complex (alpha 4(70) and alpha 4(80) forms), a receptor for fibronectin and vascular cell adhesion molecule-1. An antibody against glycoprotein IV, a receptor reported to bind thrombospondin and collagen, immunoprecipitated an 88-kD protein consistent with its reported M(r). MoAbs against alpha 4 and glycoprotein IV bound to an average of 4,600 and 17,500 sites per reticulocyte, respectively. Identification of alpha 4 beta 1 and glycoprotein IV on reticulocytes suggests both plasma-dependent and independent mechanisms of reticulocyte adhesion to endothelium and exposed extracellular matrix.

Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3548-3555 ◽  
Author(s):  
CC Joneckis ◽  
RL Ackley ◽  
EP Orringer ◽  
EA Wayner ◽  
LV Parise

Abstract The abnormal adherence of red blood cells, especially circulating reticulocytes (erythrocyte precursors), to the endothelium is believed to contribute to vascular occlusion observed in patients with sickle cell disease. Although several plasma proteins including von Willebrand factor and fibronectin have been proposed to mediate this adhesion, the mechanism of sickle cell adhesion to the endothelium remains unknown. Using flow cytometry, we screened sickle red blood cells with monoclonal antibodies (MoAbs) against known adhesion receptors and detected integrin subunits alpha 4 and beta 1 and the nonintegrin glycoprotein IV on reticulocytes but not on erythrocytes. No reactivity was detected against integrin subunits alpha 2, alpha 3, alpha 5, alpha 6, alpha v, beta 2, beta 3, integrin alpha IIb beta 3, or the nonintegrin glycoprotein Ib. Immunoprecipitation of reticulocytes with either alpha 4- or beta 1-specific antibodies identified the alpha 4 beta 1 complex (alpha 4(70) and alpha 4(80) forms), a receptor for fibronectin and vascular cell adhesion molecule-1. An antibody against glycoprotein IV, a receptor reported to bind thrombospondin and collagen, immunoprecipitated an 88-kD protein consistent with its reported M(r). MoAbs against alpha 4 and glycoprotein IV bound to an average of 4,600 and 17,500 sites per reticulocyte, respectively. Identification of alpha 4 beta 1 and glycoprotein IV on reticulocytes suggests both plasma-dependent and independent mechanisms of reticulocyte adhesion to endothelium and exposed extracellular matrix.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3058-3058
Author(s):  
Zhou Zhou ◽  
Hyojeong Han ◽  
Mark M. Udden ◽  
Miguel A. Cruz ◽  
Jing-fei Dong ◽  
...  

Abstract Abstract 3058 Poster Board II-1034 Elevated levels of von Willebrand factor (VWF), especially the ultra-large multimers, play a significant role in the pathogenesis of vascular occlusion in sickle cell disease (SCD) by promoting cell adhesion to the endothelium. Investigating the pathophysiology of vaso-occlusion and thrombosis in SCD, we have recently observed that excessive extracellular-hemoglobin (Hb) in plasma significantly inhibited ADAMTS-13 proteolysis of VWF by binding directly to the enzyme cleavage-site on VWF. Here, we further show that subpopulations of VWF multimers, which are bound to extracellular-Hb, exist in plasma. We have successfully isolated the Hb-bound VWF (HbVWF) multimers from SCD patients' plasma using the Ni-NTA column and quantified by commercial kit. The HbVWF multimers exist in 5 to 6-times less quantity than the Hb-free multimers as measured in SCD patients. Purified HbVWF multimers are mostly uncleavable by recombinant ADAMTS-13 in vitro. These HbVWF multimers are hyper active in agglutinating platelets as detected by ristocetin cofactor (RCof) activity assay, and also hyper adhesive to collagen type-III compared to the Hb-free multimers. The HbVWF multimers exists in about 2-fold more quantity in SCD patients than normal individuals [mean percent level ± SE, 8.1±1.8 (individual mean 6 – 11) vs. 16.6±3 (12 – 21), P <0.001; n=10]. Using another sandwich-ELISA assay we have reexamined the HbVWF levels, which showed a similar pattern as above. Further, the increased level of HbVWF multimers exists parallely with an elevated RCof activity of plasma VWF [mean percent activity ± SE, 100.4±15.1 (78 – 124) vs. 132.9±11.4, (109 – 149), P <0.001] and high extracellular-Hb levels [mean mg/L ± SE, 59±6.5 (42 – 96) vs. 281.5±71.7 (184 – 410), P <0.001] in plasma of SCD patients compared to normal individuals. Therefore, we believe that these hyperactive HbVWF multimers play a crucial role in cell adhesion, vascular occlusion and thrombosis in SCD. Also, we speculate that this mechanism is not only limited in SCD, but also occurred in other pathophysiological conditions associated with severe intravascular hemolysis. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
1993 ◽  
Vol 82 (6) ◽  
pp. 1891-1899 ◽  
Author(s):  
RA Swerlick ◽  
JR Eckman ◽  
A Kumar ◽  
M Jeitler ◽  
TM Wick

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.


2020 ◽  
Vol 26 (3) ◽  
pp. 329-336 ◽  
Author(s):  
Gengfan Ye ◽  
Qun Gao ◽  
Peng Qi ◽  
Junjie Wang ◽  
Shen Hu ◽  
...  

Purpose Diabetes mellitus indicated poor clinical prognosis for patients with acute ischemic stroke. Furthermore, diabetes mellitus could also impact the hemostatic system, while its influence on the histological composition of thrombus is unclear. Methods Consecutive patients with retrieved clots were included. Histologic staining for thrombus included hematoxylin and eosin, Martius Scarlet Blue, immunohistochemistry for von Willebrand factor. The differences in clot composition were compared according to diabetes mellitus history or hyperglycemia (≥7.8 mmol/L) on admission. Results A total of 52 patients were included; half of them were diagnosed as diabetes mellitus previously. Diabetic patients showed higher serum glucose on admission (8.90 vs. 7.40, p = 0.012). The baseline characteristics (expect smoking history and thrombus location), procedural, and clinical outcomes were similar between diabetic patients and nondiabetic patients. As for histologic composition, thrombus in patients with diagnosed diabetes mellitus had more fibrin (44.2% vs. 28.3%, p = 0.004) and fewer red blood cells (26.0% vs. 42.9%, p = 0.013) and equivalent content of platelets (24.0% vs. 21.5%, p = 0.694) and von Willebrand factor (0.041 vs. 0.031, p = 0.234) than patients without diabetes mellitus. However, there was no statistical difference in the content of red blood cells (41.6% vs. 27.3%, p = 0.105), fibrin (37.6% vs. 34.3%, p = 0.627), platelets (21.2% vs. 24.2%, p = 0.498), and von Willebrand factor (0.038 vs. 0.034, p = 0.284) between patients with or without hyperglycemia on admission. Conclusion Clots in diabetic patients had more fibrin and fewer erythrocyte components compared with patients without diabetes mellitus, while hyperglycemia on admission did not show association with clot composition. Further studies are needed to confirm these results.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1236-1236
Author(s):  
Swapan K. Dasgupta ◽  
Prasenjit Guchhait ◽  
Anhquyen Le ◽  
Sarvari Yellapragada ◽  
Jose Lopez ◽  
...  

Abstract Adherence of red blood cells to the endothelium initiates vaso-occlusion in sickle cell anemia. The increased adhesiveness of sickle erythrocytes is accompanied by several changes in the lipids of the erythrocyte membrane, including increased expression of phosphatidylserine (PS). One important PS-binding protein is lactadherin (also known as milk fat globule-EGF factor 8), a 45-kDa glycoprotein containing an Arg-Gly-Asp (RGD) sequence. It is secreted by macrophages and is present in normal plasma. Lactadherin promotes phagocytosis of PS-expressing apoptotic lymphocytes and sickle red blood cells by anchoring them to integrins on macrophages. Here, we investigated the role of endogenous lactadherin in adhesion of sickle erythrocytes to the endothelium. We developed a murine monoclonal antibody to human lactadherin, called L688, and investigated its effect on the adhesion of sickle red blood cells to histamine-stimulated human umbilical vein endothelial cells under hydrodynamic flow. In three experiments using washed erythrocytes resuspended in autologous plasma from three different patients with sickle cell anemia, L688 (20 μg/ml) inhibited adhesion by 24–30% (p&lt;0.01). Further evidence for an important role for lactadherin in sickle erythrocyte adhesion to endothelial cells was provided by the observation that exogenous lactadherin enhanced adhesion in a concentration-dependent manner. Lactadherin-mediated adhesion was also inhibited by monoclonal antibody abciximab, (c7E3, 10 μg/ml) which targets the β3 integrin subunit common to both αIIbβ3 and αVβ3. Control antibodies had no effect. Finally, the lactadherin-dependent adhesion of sickle erythrocytes to activated endothelium was inhibited by PS vesicles but not by phosphatidylcholine vesicles, confirming an important role for PS in sickle cell adhesion. Consistent with this, normal erythrocytes can be induced to adhere to stimulated HUVEC in a lactadherin-dependent manner by treatment with N-ethylmaleimide (10 mM) and calcium ionophore A23187 (4 μM) — treatment that exposes PS on the outer leaflet of the red cell membrane. Together, these results indicate that lactadherin mediates sickle cell adhesion to the endothelium by bridging PS on the erythrocytes with αVβ3 integrin on the endothelium. We propose that anemia in sickle cell disease is at least partially due to phagocytosis of lactadherin-coated sickle erythrocytes in the spleen, liver, and lymph nodes. Those erythrocytes that are not ingested immediately by macrophages will become more adhesive for endothelium. Thus, lactadherin appears to be involved both in sickle cell clearance from the circulation and in adhesion to endothelium.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2769-2769
Author(s):  
Michel WJ Smeets ◽  
Alexander PJ Vlaar ◽  
Herm Jan M Brinkman ◽  
Jan J Voorberg ◽  
Peter L Hordijk

Abstract Background/Objectives Red blood cell (RBC) transfusion can be lifesaving and is an essential therapy in conditions associated with tissue hypoxia due to anemia. However, recent clinical studies show that both the number of RBCs and the age of RBCs transfused are independent risk factors for an increase in transfusion related morbidity and mortality. It has been suggested that the so called “storage lesion” of RBCs, a reduction of quality of erythrocytes and changes in the erythrocyte concentrate storage medium, is the causal factor. Recently it has been shown that cold storage of erythrocytes induces microparticle formation. These erythrocyte microparticles are pro-coagulant and can cause thrombin formation. Another phenomenon of the storage lesion is the rapid and considerable loss of donor erythrocytes from the circulation of transfused patients. We wondered whether thrombin generated by transfused erythrocyte microparticles could contribute to red blood cell adherence to the vascular endothelium. Cytoadherence of red blood cells could contribute to the loss of circulating transfused red blood cells and vascular obstruction and could explain the observed transfusion associated complications in clinical practice. Methods/Results Employing FACS analysis and a microparticle analyzer we showed that erythrocyte cold storage indeed induces microparticle formation. We confirmed the pro-coagulant properties of these microparticles using a chromogenic substrate specific for thombin and a thrombin-anti-thrombin complex ELISA. To determine whether thrombin could induce adhesion of red blood cells to endothelial cells, we cultured human umbilical vein endothelial cells in micro-perfusion chambers and used live-imaging to define the adherence potential of the erythrocytes to endothelial cells at post-capillary flow rate. Thrombin stimulation of the endothelial cells did increase erythrocyte adhesion to endothelial cells. Moreover, the adhesion of erythrocytes followed a pattern resembling platelets binding to von Willebrand factor (VWF). By using live immunofluoresence imaging we confirmed that the erythrocytes did bind to VWF secreted from endothelial cells. Since erythrocyte-VWF interactions may be mediated by platelets, we used fluorescence cell sorting to remove platelets and erythrocyte-platelet complexes from erythrocyte concentrates. The purified erythrocytes did also bind to VWF secreted by endothelial cells and thereby we confirmed that erythrocytes can bind to VWF in a platelet-independent fashion. We further analyzed the specificity of the erythrocyte-VWF interaction by using different protein coatings in micro-perfusion chambers. Erythrocytes did bind to recombinant high molecular weight VWF multimers. Furthermore, they adhered more potently to VWF when compared to fibrinogen or fibrin but showed little binding to fibronectin, collagen type I, or subendothelial extra-cellular matrix proteins. Conclusion Our results suggest that transfusion of RBCs is able to induce endothelial binding of erythrocytes based on a VWF-erythrocyte interaction. We propose that passive infusion of cold stored erythrocyte derived microparticles promotes thrombin generation which subsequently activates endothelial cells and induces VWF secretion. This results in binding of red blood cells to endothelial cells in a platelet-independent fashion which requires the presence of VWF. Based on our results we hypothesize that binding of erythrocytes to VWF may occlude micro-capillaries thereby contributing to transfusion associated complications. Disclosures No relevant conflicts of interest to declare.


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