scholarly journals Neutrophils Can Adhere Via α4β1 -Integrin Under Flow Conditions

Blood ◽  
1997 ◽  
Vol 89 (10) ◽  
pp. 3837-3846 ◽  
Author(s):  
Paul H. Reinhardt ◽  
John F. Elliott ◽  
Paul Kubes
Keyword(s):  
Alternative Pathway ◽  
Human Neutrophils ◽  
Mononuclear Leukocytes ◽  
Shear Stresses ◽  
Β2 Integrin ◽  
L Cells ◽  
A Cell ◽  
Static Conditions ◽  
Factor Α ◽  
Integrin Ligand

Abstract In this study we investigated the possibility that an alternative pathway exists for neutrophil recruitment, namely an α4β1 -dependent pathway. A parallel plate chamber was used to investigate whether neutrophils could tether, roll, and adhere to tumor necrosis factor α (TNFα)-stimulated endothelium via α4β1 . α4β1 -integrin was induced on neutrophils using dihydrocytochalasin B and either an endogenous (endothelial-derived) chemotactic agent or an exogenous chemotactic molecule. α4β1 -expressing neutrophils could stably adhere under shear force (2 dyne/cm2) to TNFα-stimulated endothelium independent of the β2 -integrin. The firm adhesion was entirely abolished by antibodies directed against either the α4 or β1 -integrin subunits. However, the rolling interaction was not dependent on α4β1 but was abolished by antiselectin therapy. Neutrophils expressing α4β1 could also tether to the endothelium in the presence of antiselectin therapy, but at shear stresses less than 2 dyne/cm2. α4β1 -expressing neutrophils also tethered to and stably adhered (no rolling) to VCAM-1– but not to ICAM-1–transfected L cells. The interaction only occurred at shear stress less than 2 dyne/cm2. A cell line (Ramos) known to express high quantities of α4β1 -integrin interacted with VCAM-1–transfected L cells at very similar shear conditions. α4β1 -expressing neutrophils were also able to adhere to a second α4 -integrin ligand, fibronectin; however, this interaction only occurred under static conditions. These data suggest that, under certain conditions, neutrophils can adhere independently of the β2 -integrin pathway and adhere via the α4β1 -integrin. This study refutes the concept that α4β1 -integrin adhesion is restricted to mononuclear leukocytes and is not functional on human neutrophils.

scholarly journals Neutrophils Can Adhere Via α4β1 -Integrin Under Flow Conditions

Blood ◽  
1997 ◽  
Vol 89 (10) ◽  
pp. 3837-3846 ◽  
Author(s):  
Paul H. Reinhardt ◽  
John F. Elliott ◽  
Paul Kubes
Keyword(s):  
Alternative Pathway ◽  
Human Neutrophils ◽  
Mononuclear Leukocytes ◽  
Shear Stresses ◽  
Β2 Integrin ◽  
L Cells ◽  
A Cell ◽  
Static Conditions ◽  
Factor Α ◽  
Integrin Ligand

In this study we investigated the possibility that an alternative pathway exists for neutrophil recruitment, namely an α4β1 -dependent pathway. A parallel plate chamber was used to investigate whether neutrophils could tether, roll, and adhere to tumor necrosis factor α (TNFα)-stimulated endothelium via α4β1 . α4β1 -integrin was induced on neutrophils using dihydrocytochalasin B and either an endogenous (endothelial-derived) chemotactic agent or an exogenous chemotactic molecule. α4β1 -expressing neutrophils could stably adhere under shear force (2 dyne/cm2) to TNFα-stimulated endothelium independent of the β2 -integrin. The firm adhesion was entirely abolished by antibodies directed against either the α4 or β1 -integrin subunits. However, the rolling interaction was not dependent on α4β1 but was abolished by antiselectin therapy. Neutrophils expressing α4β1 could also tether to the endothelium in the presence of antiselectin therapy, but at shear stresses less than 2 dyne/cm2. α4β1 -expressing neutrophils also tethered to and stably adhered (no rolling) to VCAM-1– but not to ICAM-1–transfected L cells. The interaction only occurred at shear stress less than 2 dyne/cm2. A cell line (Ramos) known to express high quantities of α4β1 -integrin interacted with VCAM-1–transfected L cells at very similar shear conditions. α4β1 -expressing neutrophils were also able to adhere to a second α4 -integrin ligand, fibronectin; however, this interaction only occurred under static conditions. These data suggest that, under certain conditions, neutrophils can adhere independently of the β2 -integrin pathway and adhere via the α4β1 -integrin. This study refutes the concept that α4β1 -integrin adhesion is restricted to mononuclear leukocytes and is not functional on human neutrophils.

scholarly journals P-selectin glycoprotein ligand-1 mediates rolling of human neutrophils on P-selectin.

1995 ◽  
Vol 128 (4) ◽  
pp. 661-671 ◽  
Author(s):  
K L Moore ◽  
K D Patel ◽  
R E Bruehl ◽  
F Li ◽  
D A Johnson ◽  
...  
Keyword(s):  
Binding Sites ◽  
Fluid Phase ◽  
Human Neutrophils ◽  
Shear Stresses ◽  
High Affinity ◽  
Affinity Ligand ◽  
Activated Platelets ◽  
Static Conditions ◽  
Selectin Binding ◽  
High Affinity Ligand

Neutrophils roll on P-selectin expressed by activated platelets or endothelial cells under the shear stresses in the microcirculation. P-selectin glycoprotein ligand-1 (PSGL-1) is a high affinity ligand for P-selectin on myeloid cells. However, it has not been demonstrated that PSGL-1 contributes to the rolling of neutrophils on P-selectin. We developed two IgG mAbs, PL1 and PL2, that appear to recognize protein-dependent epitopes on human PSGL-1. The mAbs bound to PSGL-1 on all leukocytes as well as on heterologous cells transfected with PSGL-1 cDNA. PL1, but not PL2, blocked binding of 125-I-PSGL-1 to immobilized P-selectin, binding of fluid-phase P-selectin to myeloid and lymphoid leukocytes, adhesion of neutrophils to immobilized P-selectin under static conditions, and rolling of neutrophils on P-selectin-expressing CHO cells under a range of shear stresses. PSGL-1 was localized to microvilli on neutrophils, a topography that may facilitate its adhesive function. These data indicate that (a) PSGL-1 accounts for the high affinity binding sites for P-selectin on leukocytes, and (b) PSGL-1 must interact with P-selectin in order for neutrophils to roll on P-selectin at physiological shear stresses.

scholarly journals Platelet and Fibrin Deposition at the Damaged Vessel Wall: Cooperative Substrates for Neutrophil Adhesion Under Flow Conditions

Blood ◽  
1997 ◽  
Vol 89 (1) ◽  
pp. 166-175 ◽  
Author(s):  
P.H.M. Kuijper ◽  
H.I. Gallardo Torres ◽  
J.-W.J. Lammers ◽  
J.J. Sixma ◽  
L. Koenderman ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Human Neutrophils ◽  
Shear Stresses ◽  
Dependent Manner ◽  
Fibrin Deposition ◽  
Flow Conditions ◽  
Shear Rates ◽  
Fibrin Network ◽  
Static Conditions ◽  
Blocking Antibodies

Abstract At sites of vessel wall damage, the primary hemostatic reaction involves platelet and fibrin deposition. At these sites, circulating leukocytes marginate and become activated. Adhered platelets can support leukocyte localization; however, the role of fibrin in this respect is not known. We studied the adhesion of human neutrophils (polymorphonuclear leukocytes [PMNs]) to endothelial extracellular matrix (ECM)-bound fibrin and platelets under flow conditions. ECM alone did not show PMN adhesion. ECM-coated cover slips were perfused with plasma to form a surface-bound fibrin network, and/or with whole blood to allow platelet adhesion. Unstimulated PMNs adhered to fibrin at moderate shear stress (20 to 200 mPa). ECM-bound platelets induced rolling adhesion and allowed more PMNs to adhere at higher shear (320 mPa). ECM coated with both platelets and fibrin induced more static and shear-resistant PMN adhesion. PMN adhesion to fibrin alone but not to platelet/fibrin surfaces was inhibited by soluble fibrinogen. Adhesion to fibrin alone was inhibited by CD11b and CD18 blocking antibodies. Furthermore, fibrin formed under flow conditions showed up to threefold higher PMN adhesion compared with fibrin formed under static conditions, due to structural differences. These results indicate that circulating PMNs adhere to fibrin in an integrin-dependent manner at moderate shear stresses. However, at higher shear rates (<200 mPa), additional mechanisms (ie, activated platelets) are necessary for an interaction of PMNs with a fibrin network.

scholarly journals Platelet and Fibrin Deposition at the Damaged Vessel Wall: Cooperative Substrates for Neutrophil Adhesion Under Flow Conditions

Blood ◽  
1997 ◽  
Vol 89 (1) ◽  
pp. 166-175 ◽  
Author(s):  
P.H.M. Kuijper ◽  
H.I. Gallardo Torres ◽  
J.-W.J. Lammers ◽  
J.J. Sixma ◽  
L. Koenderman ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Human Neutrophils ◽  
Shear Stresses ◽  
Dependent Manner ◽  
Fibrin Deposition ◽  
Flow Conditions ◽  
Shear Rates ◽  
Fibrin Network ◽  
Static Conditions ◽  
Blocking Antibodies

At sites of vessel wall damage, the primary hemostatic reaction involves platelet and fibrin deposition. At these sites, circulating leukocytes marginate and become activated. Adhered platelets can support leukocyte localization; however, the role of fibrin in this respect is not known. We studied the adhesion of human neutrophils (polymorphonuclear leukocytes [PMNs]) to endothelial extracellular matrix (ECM)-bound fibrin and platelets under flow conditions. ECM alone did not show PMN adhesion. ECM-coated cover slips were perfused with plasma to form a surface-bound fibrin network, and/or with whole blood to allow platelet adhesion. Unstimulated PMNs adhered to fibrin at moderate shear stress (20 to 200 mPa). ECM-bound platelets induced rolling adhesion and allowed more PMNs to adhere at higher shear (320 mPa). ECM coated with both platelets and fibrin induced more static and shear-resistant PMN adhesion. PMN adhesion to fibrin alone but not to platelet/fibrin surfaces was inhibited by soluble fibrinogen. Adhesion to fibrin alone was inhibited by CD11b and CD18 blocking antibodies. Furthermore, fibrin formed under flow conditions showed up to threefold higher PMN adhesion compared with fibrin formed under static conditions, due to structural differences. These results indicate that circulating PMNs adhere to fibrin in an integrin-dependent manner at moderate shear stresses. However, at higher shear rates (<200 mPa), additional mechanisms (ie, activated platelets) are necessary for an interaction of PMNs with a fibrin network.

Analysis of the Dynamics of the Electric Capacitance of a Cell Monolayer at the Late Stages of Caco-2 cell Differentiation

2019 ◽  
Vol 35 (6) ◽  
pp. 87-90
Author(s):  
S.V. Nikulin ◽  
V.A. Petrov ◽  
D.A. Sakharov
Keyword(s):  
Impedance Spectroscopy ◽  
Cell Monolayer ◽  
Microfluidic Chips ◽  
Russian Science ◽  
Electric Capacitance ◽  
A Cell ◽  
Static Conditions ◽  
Late Stages

The real-time monitoring of electric capacitance (impedance spectroscopy) allowed obtaining evidence that structures which look like intestinal villi can be formed during the cultivation under static conditions as well as during the cultivation in microfluidic chips. It was shown in this work via transcriptome analysis that the Hh signaling pathway is involved in the formation of villus-like structures in vitro, which was previously shown for their formation in vivo. impedance spectroscopy, intestine, villi, electric capacitance, Hh The study was funded by the Russian Science Foundation (Project 16-19-10597).

Syndecan-4-dependent signaling in the inhibition of endotoxin-induced endothelial adherence of neutrophils by antithrombin

2003 ◽  
Vol 90 (12) ◽  
pp. 1150-1157 ◽  
Author(s):  
Nicole Kaneider ◽  
Ellen Förster ◽  
Birgit Mosheimer ◽  
Daniel Sturn ◽  
Christian Wiedermann
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Interleukin 1 ◽  
Human Neutrophils ◽  
Heparin Binding ◽  
Clotting Factors ◽  
Edema Formation ◽  
Granulocyte Elastase ◽  
Umbilical Vein Endothelial Cells ◽  
Static Conditions

SummaryCirculating endotoxin is elevated in sepsis and plays a role in endothelial dysfunction whereas antithrombin is decreased by virtue of its consumption during complex formation with clotting factors and by proteolytic degradation by granulocyte elastase. Dysfunction of endothelium results in enhanced leukocyte rolling and diapedesis into tissues leading to edema formation and injury. Antithrombin exerts beneficial effects on endothelial function in sepsis. A direct anti-inflammatory action of anti-thrombin in inflammatory cells is exerted via heparan sulfate proteoglycans. In this study, we investigated whether antithrom-bin affects endotoxin-induced adhesion of neutrophils to human endothelial cells in vitro and whether glycosaminoglycans are involved in its signaling. Adhesion of human neutrophils to monolayers of umbilical vein endothelial cells was tested under static conditions. Endothelial cells were pretreated with endotoxin, interleukin-1, heparinase-I, chondroitinase-ABC or anti-syndecan-4-antibody. Endotoxin and interleukin-1 increased neutrophil adherence to human umbilical vein endothelial cells which was inhibited by antithrombin. Concomitant incubation with pentasaccharide abolished this effect of antithrombin. Treatment of endothelial cells with heparinase or chondroitinase led to higher adhesion and prevented effects of antithrom-bin. With antibodies to syndecan-4, enhanced adhesion of neutrophils was observed. As studied by Western blotting, endo-toxin-induced signaling was diminished by antithrombin and the effect was reversible by chondroitinase or heparinase. From our results, we can conclude that endotoxin-induced adhesion of leukocytes to endothelium can be reversed by ligation of syndecan-4 with antithrombin´s heparin-binding site and interferences with stress response signaling events in endothelium.

Vitexin inhibits APEX1 to counteract the flow-induced endothelial inflammation

2021 ◽  
Vol 118 (48) ◽  
pp. e2115158118
Author(s):  
Chuan-Rong Zhao ◽  
Fang-Fang Yang ◽  
Qinghua Cui ◽  
Dong Wang ◽  
Yiran Zhou ◽  
...  
Keyword(s):  
Laminar Flow ◽  
Nuclear Translocation ◽  
Vascular Endothelial Cells ◽  
Animal Experiments ◽  
Shear Stresses ◽  
Neointimal Formation ◽  
Disturbed Flow ◽  
Endothelial Inflammation ◽  
Therapeutic Molecules ◽  
Factor Α

Vascular endothelial cells are exposed to shear stresses with disturbed vs. laminar flow patterns, which lead to proinflammatory vs. antiinflammatory phenotypes, respectively. Effective treatment against endothelial inflammation and the consequent atherogenesis requires the identification of new therapeutic molecules and the development of drugs targeting these molecules. Using Connectivity Map, we have identified vitexin, a natural flavonoid, as a compound that evokes the gene-expression changes caused by pulsatile shear, which mimics laminar flow with a clear direction, vs. oscillatory shear (OS), which mimics disturbed flow without a clear direction. Treatment with vitexin suppressed the endothelial inflammation induced by OS or tumor necrosis factor-α. Administration of vitexin to mice subjected to carotid partial ligation blocked the disturbed flow-induced endothelial inflammation and neointimal formation. In hyperlipidemic mice, treatment with vitexin ameliorated atherosclerosis. Using SuperPred, we predicted that apurinic/apyrimidinic endonuclease1 (APEX1) may directly interact with vitexin, and we experimentally verified their physical interactions. OS induced APEX1 nuclear translocation, which was inhibited by vitexin. OS promoted the binding of acetyltransferase p300 to APEX1, leading to its acetylation and nuclear translocation. Functionally, knocking down APEX1 with siRNA reversed the OS-induced proinflammatory phenotype, suggesting that APEX1 promotes inflammation by orchestrating the NF-κB pathway. Animal experiments with the partial ligation model indicated that overexpression of APEX1 negated the action of vitexin against endothelial inflammation, and that endothelial-specific deletion of APEX1 ameliorated atherogenesis. We thus propose targeting APEX1 with vitexin as a potential therapeutic strategy to alleviate atherosclerosis.

A cell-free preparation of human neutrophils catalyzing NADPH-dependent conversion of leukotriene B4

1984 ◽  
Vol 125 (2) ◽  
pp. 615-621 ◽  
Author(s):  
Hideki Sumimoto ◽  
Koichiro Takeshige ◽  
Hironori Sakai ◽  
Shigeki Minakami
Keyword(s):  
Leukotriene B4 ◽  
Human Neutrophils ◽  
A Cell
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