scholarly journals Monocyte adhesion to subendothelial components

Blood ◽  
1987 ◽  
Vol 69 (4) ◽  
pp. 1265-1268
Author(s):  
JW Tobias ◽  
MM Bern ◽  
PA Netland ◽  
BR Zetter
Keyword(s):  
Cell Line ◽  
Human Leukocyte ◽  
Adhesion Assay ◽  
U937 Cells ◽  
Monocyte Adhesion ◽  
Active Components ◽  
Dot Blot ◽  
Collagen Types ◽  
Subendothelial Matrix ◽  
Soluble Acid

Human monocytes have been shown to penetrate the endothelial layer of large blood vessels and to adhere to the subendothelial basement membrane. To determine the active components of this process, we have studied the ability of monocytes to adhere to isolated components of the subendothelial matrix. Using a quantitative dot-blot adhesion assay, we find that monocytes adhere preferentially to immobilized laminin and elastin. The monocytes adhere less well to fibronectin and bind poorly or not at all to collagen types I and IV, or to heparan sulfate. Monocyte binding to elastin requires an intact, crosslinked molecule as no binding was observed to soluble, acid-alcohol elastin extracts, to pepsin or elastase digests of elastin, to tropoelastin monomer, or to desmosine/isodesmosine crosslinks. Similar binding profiles to elastin, laminin, and fibronectin were seen with the established human leukocyte cell line U937. The promyelocytic cell line HL60 adhered equally well to laminin but showed slightly reduced adhesion to elastin when compared with the fresh monocytes or U937 cells. Freshly isolated human erythrocytes did not demonstrate significant adhesion to fibronectin, laminin, or elastin.

scholarly journals Monocyte adhesion to subendothelial components

Blood ◽  
1987 ◽  
Vol 69 (4) ◽  
pp. 1265-1268 ◽  
Author(s):  
JW Tobias ◽  
MM Bern ◽  
PA Netland ◽  
BR Zetter
Keyword(s):  
Cell Line ◽  
Human Leukocyte ◽  
Adhesion Assay ◽  
U937 Cells ◽  
Monocyte Adhesion ◽  
Active Components ◽  
Dot Blot ◽  
Collagen Types ◽  
Subendothelial Matrix ◽  
Soluble Acid

Abstract Human monocytes have been shown to penetrate the endothelial layer of large blood vessels and to adhere to the subendothelial basement membrane. To determine the active components of this process, we have studied the ability of monocytes to adhere to isolated components of the subendothelial matrix. Using a quantitative dot-blot adhesion assay, we find that monocytes adhere preferentially to immobilized laminin and elastin. The monocytes adhere less well to fibronectin and bind poorly or not at all to collagen types I and IV, or to heparan sulfate. Monocyte binding to elastin requires an intact, crosslinked molecule as no binding was observed to soluble, acid-alcohol elastin extracts, to pepsin or elastase digests of elastin, to tropoelastin monomer, or to desmosine/isodesmosine crosslinks. Similar binding profiles to elastin, laminin, and fibronectin were seen with the established human leukocyte cell line U937. The promyelocytic cell line HL60 adhered equally well to laminin but showed slightly reduced adhesion to elastin when compared with the fresh monocytes or U937 cells. Freshly isolated human erythrocytes did not demonstrate significant adhesion to fibronectin, laminin, or elastin.

scholarly journals Impact of cigarette versus electronic cigarette aerosol conditioned media on aortic endothelial cells in a microfluidic cardiovascular model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Om Makwana ◽  
Gina A. Smith ◽  
Hannah E. Flockton ◽  
Gary P. Watters ◽  
Frazer Lowe ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Human Monocyte ◽  
Conditioned Media ◽  
Electronic Cigarette ◽  
Microfluidic Channels ◽  
Adhesion Assay ◽  
Monocyte Adhesion ◽  
Aortic Endothelial Cells ◽  
Aortic Endothelial

AbstractAtherosclerosis is a complex process involving progressive pathological events, including monocyte adhesion to the luminal endothelial surface. We have developed a functional in vitro adhesion assay using BioFlux microfluidic technology to investigate THP-1 (human acute monocytic leukaemia cell) monocyte adhesion to human aortic endothelial cells (HAECs). The effect of whole smoke conditioned media (WSCM) generated from University of Kentucky reference cigarette 3R4F, electronic cigarette vapour conditioned media (eVCM) from an electronic nicotine delivery system (ENDS) product (Vype ePen) and nicotine on monocyte adhesion to HAECs was evaluated. Endothelial monolayers were grown in microfluidic channels and exposed to 0–1500 ng/mL nicotine or nicotine equivalence of WSCM or eVCM for 24 h. Activated THP-1 cells were perfused through the channels and a perfusion, adhesion period and wash cycle performed four times with increasing adhesion period lengths (10, 20, 30 and 40 min). THP-1 cell adhesion was quantified by counting adherent cells. WSCM induced dose-dependent increases in monocyte adhesion compared to vehicle control. No such increases were observed for eVCM or nicotine. Adhesion regulation was linked to increased ICAM-1 protein expression. Staining of ICAM-1 in HAECs and CD11b (MAC-1) in THP-1 cells demonstrated adhesion molecule co-localisation in BioFlux plates. The ICAM-1 adhesion response to WSCM was downregulated by transfecting HAECs with ICAM-1 siRNA. We conclude that the BioFlux system is able to model human monocyte adhesion to primary human endothelial cells in vitro and WSCM drives the greatest increase in monocyte adhesion via a mechanism involving endothelial ICAM-1 expression.

scholarly journals Sphingosine-1-phosphate inhibits high glucose-mediated ERK1/2 action in endothelium through induction of MAP kinase phosphatase-3

2009 ◽  
Vol 296 (2) ◽  
pp. C339-C345 ◽  
Author(s):  
Angela M. Whetzel ◽  
David T. Bolick ◽  
Catherine C. Hedrick
Keyword(s):  
Endothelial Cells ◽  
Type 1 Diabetes ◽  
Vascular Complications ◽  
Nod Mice ◽  
Endothelial Activation ◽  
Adhesion Assay ◽  
Monocyte Adhesion ◽  
Map Kinase Phosphatase ◽  
Sphingosine 1 Phosphate

Endothelial activation is a key early event in vascular complications of Type 1 diabetes. The nonobese diabetic (NOD) mouse is a well-characterized model of Type 1 diabetes. We previously reported that Type 1 diabetic NOD mice have increased endothelial activation, with increased production of monocyte chemoattractant protein (MCP)-1 and IL-6, and a 30% increase of surface VCAM-1 expression leading to a fourfold increase in monocyte adhesion to the endothelium. Sphingosine-1-phosphate (S1P) prevents monocyte:endothelial interactions in these diabetic NOD mice. Incubation of diabetic NOD endothelial cells (EC) with S1P (100 nmol/l) reduced ERK1/2 phosphorylation by 90%, with no significant changes in total ERK1/2 protein. In the current study, we investigated the mechanism of S1P action on ERK1/2 to reduce activation of diabetic endothelium. S1P caused a significant threefold increase in mitogen-activated kinase phosphatase-3 (MKP-3) expression in EC. MKP-3 selectively regulates ERK1/2 activity through dephosphorylation. Incubation of diabetic NOD EC with S1P and the S1P1-selective agonist SEW2871 significantly increased expression of MKP-3 and reduced ERK1/2 phosphorylation, while incubation with the S1P1/S1P3 antagonist VPC23019 decreased the expression of MKP-3, both results supporting a role for S1P1 in MKP-3 regulation. To mimic the S1P-mediated induction of MKP-3 diabetic NOD EC, we overexpressed MKP-3 in human aortic endothelial cells (HAEC) cultured in elevated glucose (25 mmol/l). Overexpression of MKP-3 in glucose-cultured HAEC decreased ERK1/2 phosphorylation and resulted in decreased monocyte:endothelial interactions in a static monocyte adhesion assay. Finally, we used small interfering RNA to MKP-3 and observed increased monocyte adhesion. Moreover, S1P was unable to inhibit monocyte adhesion in the absence of MKP-3. Thus, one mechanism for the anti-inflammatory action of S1P in diabetic EC is inhibition of ERK1/2 phosphorylation through induction of MKP-3 expression via the S1P-S1P1 receptor axis.

scholarly journals Acid phosphatase activity in mononuclear phagocytes and the U937 cell line: monocyte-derived macrophages express tartrate-resistant acid phosphatase

Blood ◽  
1986 ◽  
Vol 67 (3) ◽  
pp. 729-734
Author(s):  
RG Snipes ◽  
KW Lam ◽  
RC Dodd ◽  
TK Gray ◽  
MS Cohen
Keyword(s):  
Acid Phosphatase ◽  
Cell Line ◽  
Gel Electrophoresis ◽  
U937 Cell ◽  
Colorimetric Assay ◽  
Mononuclear Phagocytes ◽  
Tartrate Resistant Acid Phosphatase ◽  
U937 Cells ◽  
Phagocytic Cells ◽  
The Relationship

Tartrate-resistant acid phosphatase (TRAcP) is used as a marker for osteoclasts, which are believed to be derived from phagocytic cells or phagocyte stem cell precursors. To further investigate the relationship between monocytic phagocytes and osteoclasts, acid phosphatase (AcP) activity was measured by three different techniques in human peripheral blood monocytes, monocyte-derived macrophages, and the U937 cell line. We found that cytochemistry and gel electrophoresis led to similar results, but that the colorimetric assay was inconsistent. Normal human peripheral monocytes expressed both tartrate-sensitive and -resistant AcP. In culture these cells formed polykaryons and expressed TRAcP activity that was further identified as an isoenzyme associated with bone tissue. In contrast, the U937 cells did not express TRAcP activity as measured by gel electrophoresis. Both U937 cells and monocytes possess material that interferes with interpretation of the colorimetric assay of AcP. The presence of TRAcP in monocyte-derived macrophages further supports the relationship between phagocytic cells and bone osteoclasts.

scholarly journals Selection of U937 histiocytic lymphoma cells highly responsive to phorbol ester-induced differentiation using monoclonal antibody to the eosinophil cytotoxicity-enhancing factor

Blood ◽  
1990 ◽  
Vol 75 (12) ◽  
pp. 2427-2433 ◽  
Author(s):  
MI Elsas ◽  
AJ Dessein ◽  
PX Elsas
Keyword(s):  
Cell Line ◽  
Phorbol Ester ◽  
Fold Increase ◽  
U937 Cells ◽  
Induced Differentiation ◽  
Fourfold Increase ◽  
Enhancing Factor ◽  
Histiocytic Lymphoma ◽  
Before And After ◽  
P Cells

Abstract Monoclonal antibodies (MoAbs) to the eosinophil cytotoxicity-enhancing factor (ECEF) were used to detect ECEF in U937 cells before and after phorbol ester (PMA)-induced differentiation into ECEF-secreting macrophages. Membrane-associated ECEF (mECEF), apparently an integral membrane component, is found in U937 cells and in 70% of monocytes and, at lower levels, on blood T lymphocytes. Expression of mECEF in U937 cells is heterogeneous, as is responsiveness to PMA. In PMA-treated cultures, the strongest mECEF expression is on adherent, differentiated macrophages, rather than on activated, nonadherent cells. To study the relationship of mECEF to PMA responsiveness, we positively selected by “panning” a cell line (U937 P+) with significantly higher mECEF expression than that of U937. U937 P+ cells respond to PMA as a differentiation stimulus more effectively than do U937 cells, with a fourfold increase in the number of differentiated macrophages (P less than .001) and a faster rate of differentiation (a fourfold increase at t = 12 hours, P less than .001). U937 P+ cells also show a 7.4-fold increase in response to suboptimal doses of PMA (P less than .001). These findings suggest that mECEF expression correlates with responsiveness to a differentiation stimulus in a histiocytic lymphoma cell line that is widely used as a model of monocyte maturation.

scholarly journals Cell surface expression of murine, rat, and human Fc receptors by Xenopus oocytes.

1984 ◽  
Vol 160 (2) ◽  
pp. 606-611 ◽  
Author(s):  
E Pure ◽  
A D Luster ◽  
J C Unkeless
Keyword(s):  
Plasma Membrane ◽  
Cell Line ◽  
Surface Expression ◽  
Gamma Interferon ◽  
Membrane Receptors ◽  
Cell Surface Expression ◽  
Xenopus Laevis Oocytes ◽  
High Avidity ◽  
U937 Cells ◽  
Mouse Igg2a

We report that Xenopus laevis oocytes can efficiently translate and insert heterologous membrane receptors into the oocyte plasma membrane, where they can be detected by the binding of either monoclonal antibodies or ligands. Thus, oocytes injected with mRNA from the mouse J774 macrophage-like cell line, the rat RBL-1 basophilic leukemia, and the U937 promonocyte cell line, bound 2.4G2 Fab, rat IgE, and mouse IgG2a, respectively. The increase in the high avidity Fc gamma R observed after gamma-interferon induction of U937 cells was also observed after injection of mRNA from gamma-interferon-induced U937 cells into oocytes. This suggests either much greater message stability or a greater rate of transcription of Fc gamma Rhi mRNA in the gamma-interferon-induced cells. The assay affords a sensitive method for the detection of rare mRNA species that code for plasma membrane proteins.

HLA class II genotyping: two assay systems compared

1995 ◽  
Vol 41 (4) ◽  
pp. 553-556 ◽  
Author(s):  
J Thonnard ◽  
F Deldime ◽  
M Heusterspreute ◽  
B Delepaut ◽  
F Hanon ◽  
...  
Keyword(s):  
Large Scale ◽  
Clinical Laboratory ◽  
Blot Hybridization ◽  
Human Leukocyte ◽  
Hla Typing ◽  
High Rate ◽  
Polymorphism Analysis ◽  
Dot Blot ◽  
Pcr Products ◽  
Typing Methods

Abstract In the last few years, a variety of DNA-based human leukocyte antigen (HLA) typing methods have emerged, revealing the extreme polymorphism of HLA genes. This polymorphism makes it difficult for a clinical laboratory to establish the best HLA typing strategy. In this study we have compared two techniques for performing HLA-DRB typing: a commercial rapid assay based on the polymerase chain reaction (PCR) followed by reverse dot-blot hybridization of the PCR products (the Inno-LiPA assay), and a method based on PCR followed by restriction fragment length polymorphism analysis. We found that both methods provide reliable results with a high rate of concordance (97%) and that Inno-LiPA is convenient for large-scale routine typing. However, if a high-resolution allelic typing is required, each method lacks accuracy but using them in association improves the accuracy of the results.

Interaction of Thrombin-Stimulated Platelets with Vitronectin (S-Protein of Complement) Substrate: Inhibition by a Monoclonal Antibody to Glycoprotein IIb-IIIa Complex

1988 ◽  
Vol 60 (03) ◽  
pp. 514-517 ◽  
Author(s):  
Perumal Thiagarajan ◽  
Kathleen Kelly
Keyword(s):  
Synthetic Peptides ◽  
Vessel Wall ◽  
Divalent Cations ◽  
Substrate Inhibition ◽  
Adhesion Assay ◽  
Dependent Manner ◽  
Activated Platelets ◽  
Subendothelial Matrix ◽  
Dose Dependent ◽  
Adhesion Of Platelets

SummaryPlatelets adhere to vitronectin substrate following activation with physiological concentrations of thrombin. Adhesion of activated platelets to vitronectin substrate is dependent upon the presence of divalent cations, the amount of vitronectin, and the duration of adhesion assay. The adhesion of platelets is inhibited by synthetic peptides containing the sequence of Arg-Gly-Asp. In addition, monoclonal antibodies to glycoprotein IIb-IIIa complex inhibit the adhesion of activated platelets to vitronectin substrate in a dose-dependent manner. These studies suggest that the glycoprotein IIb-IIIa complex on activated platelets may interact with vitronectin substrate through the Arg-Gly-Asp mechanism. Since vitronectin is present in the subendothelial matrix, it might be involved in platelet-vessel wall interactions

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