scholarly journals Semaphorin 4D inhibits neutrophil activation and is involved in the pathogenesis of neutrophil-mediated autoimmune vasculitis

2017 ◽  
Vol 76 (8) ◽  
pp. 1440-1448 ◽  
Author(s):  
Masayuki Nishide ◽  
Satoshi Nojima ◽  
Daisuke Ito ◽  
Hyota Takamatsu ◽  
Shohei Koyama ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Surface ◽  
Oxidative Burst ◽  
Serum Levels ◽  
Surface Expression ◽  
Proteolytic Cleavage ◽  
Neutrophil Activation ◽  
Cell Surface Expression ◽  
Human Neutrophils ◽  
Semaphorin 4D

ObjectivesInappropriate activation of neutrophils plays a pathological role in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The aim of this study was to investigate the functions of semaphorin 4D (SEMA4D) in regulation of neutrophil activation, and its involvement in AAV pathogenesis.MethodsSerum levels of soluble SEMA4D were evaluated by ELISA. Blood cell-surface expression of membrane SEMA4D was evaluated by flow cytometry. To determine the functional interactions between neutrophil membrane SEMA4D and endothelial plexin B2, wild-type and SEMA4D−/− mice neutrophils were cultured with an endothelial cell line (MS1) stained with SYTOX green, and subjected to neutrophil extracellular trap (NET) formation assays. The efficacy of treating human neutrophils with recombinant plexin B2 was assessed by measuring the kinetic oxidative burst and NET formation assays.ResultsSerum levels of soluble SEMA4D were elevated in patients with AAV and correlated with disease activity scores. Cell-surface expression of SEMA4D was downregulated in neutrophils from patients with AAV, a consequence of proteolytic cleavage of membrane SEMA4D. Soluble SEMA4D exerted pro-inflammatory effects on endothelial cells. Membranous SEMA4D on neutrophils bound to plexin B2 on endothelial cells, and this interaction decreased NET formation. Recombinant plexin B2 suppressed neutrophil Rac1 activation through SEMA4D’s intracellular domain, and inhibited pathogen-induced or ANCA-induced oxidative burst and NET formation.ConclusionsNeutrophil surface SEMA4D functions as a negative regulator of neutrophil activation. Proteolytic cleavage of SEMA4D as observed in patients with AAV may amplify neutrophil-mediated inflammatory responses. SEMA4D is a promising biomarker and potential therapeutic target for AAV.

ErbB2 Expression on Left Ventricular Epicardial Endothelial Cells and CD105+ Cells is Decreased in Patients with Diabetes Mellitus.

2021 ◽  
Author(s):  
Joanne T. deKay ◽  
Joshua Carver ◽  
Bailey Shevenell ◽  
Angela M. Kosta ◽  
Sergey Tsibulnikov ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Endothelial Cells ◽  
Cell Surface ◽  
High Glucose ◽  
Artery Bypass ◽  
Surface Expression ◽  
Left Ventricular ◽  
Cell Surface Expression ◽  
Erbb Receptors ◽  
Diabetic Patients

Abstract Background We investigated the cell surface expression of ErbB receptors on left ventricular (LV) epicardial endothelial cells and CD105+ cells obtained from cardiac biopsies of patients undergoing coronary artery bypass grafting surgery (CABG). Methods Endothelial cells and CD105+ non-endothelial cells were freshly isolated from LV epicardial biopsies obtained from 15 subjects with diabetes mellitus (DM) and 8 controls. The expression of ErbB recepotrs was examined using multiparametric flow cytometry. Human microvascular endothelial cells (HMEC-1) and LV epicardial CD105+ non-endothelial cells were used to determine the effect of high glucose on ADAM10-dependent cleavage of ErbB receptors. Results We found that diabetes mellitus (DM) and high levels of hemoglobin A1C are associated with reduced expression of ErbB2 on both endothelial cells and CD105+ non-endothelial cells. To determine if the expression of ErbB2 receptors is regulated by glucose levels, we examined the effect of high glucose in HMEC-1 and LV epicardial CD105+ non-endothelial cells, using a novel flow cytometric approach to simultaneously determine the total level, cell surface expression, and phosphorylation of ErbB2. Incubation of cells in the presence of 25 mM D-glucose resulted in decreased cell surface expression of ErbB2. We also found high expression of a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) on both endothelial cells and CD105+ non-endothelial cells. Inhibition of ADAM10 prevented the high glucose-dependent decrease in the cell surface expression of ErbB2. Conclusions We suggest that high glucose depresses ErbB receptor signaling in endothelial cells and cardiac progenitor cells via the promotion of ADAM10-dependent cleavage of ErbB2 at the cell surface, thus contributing to vascular dysfunction and adverse remodeling seen in diabetic patients.

CD39/NTPDase1 Variants Identified in Human Neutrophils Regulate Antithrombotic Activity.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3088-3088 ◽  
Author(s):  
Kim E. Olson ◽  
Dianne Pulte ◽  
Marinus Johan Broekman ◽  
Ashley E. Olson ◽  
Joan Drosopoulos ◽  
...  
Keyword(s):  
Cell Surface ◽  
Atpase Activity ◽  
Western Blot ◽  
Transmembrane Domain ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Human Neutrophils ◽  
Platelet Activity ◽  
Total Rna ◽  
Cos Cells

Abstract Blood-borne cellular elements expressing ectonucleotidase activity have been shown to regulate platelet activation and recruitment in response to agonists. In particular, exposure of a platelet releasate to isolated neutrophils (PMN) results in loss of its platelet activating activity in a subsequent assay (Valles et al, J Clin Invest1993, 92:1357–1365). Whereas expression of CD39 on vascular endothelial cells has been well characterized, expression on leukocytes has been less well studied. Freshly prepared lymphocyte and PMN cell populations were evaluated for both cell surface expression of CD39 and ectonucleotidase activity. FACS analysis showed that 98% of PMN were positive for CD39 compared to only 20% of lymphocytes. In addition, neutrophils stained more intensely, indicating the presence of a higher quantity of cell surface-expressed CD39. Interestingly, neutrophils exhibited only 1/3 of the ATPase and 1/2 of the ADPase activities of the same number of lymphocytes, although the latter are thought to have greater antithrombotic capacity. RT-PCR products from total RNA isolated from lymphocytes and PMN were sequenced. This revealed alternately spliced CD39 mRNA species present in PMN at levels equal to that of CD39 mRNA. In contrast, lymphocytes, which showed much higher levels of CD39 mRNA, expressed these variants at much lower levels. RACE analyses of cDNAs generated from total RNA demonstrated two CD39 gene-derived mRNAs. Each was comprised of an alternate 3′ segment lacking the C-terminal transmembrane domain, and distinguished by an internal deletion. Myc- and Flag-tagged constructs expressed in COS cells resulted in cell surface expression of the respectively tagged variants (immunocytochemistry, western blot analyses of plasma membrane preparations). Membrane preparations assayed for enzyme activity revealed no apyrase activity for either molecule expressed alone or together. Co-transfection of CD39 with equal amounts of either construct singly or in combination resulted in a 30-50% decrease in ATPase activity compared to CD39 alone. Similarly, CD39 co-expressed with either construct alone lost 75–90% of its ADPase activity. Unexpectedly, co-transfection of CD39 with both variants together resulted in a 20–40% increase in ADPase activity. Glutaraldehyde cross-linking of membrane preparations from triply transfected COS cells followed by immunoprecipitation and western blot analyses demonstrated the presence of all three species in higher order complexes. Thus, both variants can simultaneously associate with CD39, generating hetero-multimers with altered substrate preference and catalytic efficiency compared to CD39 tetramers. These observations add to our understanding of the regulation of ectonucleotidase activity at the cell surface. The balanced expression of CD39 and its two identified variants may underlie the anti-platelet activity of neutrophils previously reported. The finding that association of CD39 with either construct alone results in near complete loss of ADPase activity with only partial diminution of ATPase activity suggests a possible etiology for a pro-thrombotic phenotype.

Perfusion with sickle erythrocytes up-regulates ICAM-1 andVCAM-1 gene expression in cultured human endothelial cells

Blood ◽  
2000 ◽  
Vol 95 (10) ◽  
pp. 3232-3241 ◽  
Author(s):  
Yan-Ting Shiu ◽  
Mark M. Udden ◽  
Larry V. McIntire
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Cell Adhesion ◽  
Cell Surface ◽  
Sickle Cell ◽  
Cell Adhesion Molecules ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Human Endothelial Cells ◽  
Sickle Erythrocytes

Sickle cell anemia is characterized by periodic vasoocclusive crises. Increased adhesion of sickle erythrocytes to vascular endothelium is a possible contributing factor to vasoocclusion. This study determined the effect of sickle erythrocyte perfusion at a venous shear stress level (1 dyne/cm2) on endothelial cell (EC) monolayers. Sickle erythrocytes up-regulated intercellular adhesion molecule-1 (ICAM-1) gene expression in cultured human endothelial cells. This was accompanied by increased cell surface expression of ICAM-1 and also elevated release of soluble ICAM-1 molecules. Expression of vascular cell adhesion molecule-1 (VCAM-1) messenger RNA (mRNA) was also strikingly elevated in cultured ECs after exposure to sickle cell perfusion, although increases in membrane-bound and soluble VCAM-1 levels were small. The presence of cytokine interleukin-1β in the perfusion system enhanced the production of ICAM-1 and VCAM-1 mRNA, cell surface expression, and the concentrations of circulating forms. This is the first demonstration that sickle erythrocytes have direct effects on gene regulation in cultured human ECs under well-defined flow environments. The results suggest that perfusion with sickle erythrocytes increases the expression of cell adhesion molecules on ECs and stimulates the release of soluble cell adhesion molecules, which may serve as indicators of injury and/or activation of endothelial cells. The interactions between sickle red blood flow, inflammatory cytokines, and vascular adhesion events may render sickle cell disease patients vulnerable to vasoocclusive crises.

scholarly journals Lovastatin Enhances Ecto-5′-Nucleotidase Activity and Cell Surface Expression in Endothelial Cells

2002 ◽  
Vol 90 (4) ◽  
pp. 420-427 ◽  
Author(s):  
S. Ledoux ◽  
D. Laouari ◽  
M. Essig ◽  
I. Runembert ◽  
G. Trugnan ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Surface ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Nucleotidase Activity
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