High-temporal-resolution analysis demonstrates that ICAM-1 stabilizes WEHI 274.1 monocytic cell rolling on endothelium

2003 ◽  
Vol 285 (1) ◽  
pp. C112-C118 ◽  
Author(s):  
Christopher G. Kevil ◽  
John H. Chidlow ◽  
Daniel C. Bullard ◽  
Dennis F. Kucik
Keyword(s):  
Temporal Resolution ◽  
High Temporal Resolution ◽  
Leukocyte Rolling ◽  
Wild Type ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Rolling Velocity ◽  
Tnf Α ◽  
Resolution Analysis ◽  
Adhesive Interactions

Leukocyte rolling, adhesion, and migration on vascular endothelium involve several sets of adhesion molecules that interact simultaneously. Each of these receptor-ligand pairs may play multiple roles. We examined the role of ICAM-1 in adhesive interactions with mouse aortic endothelial cells (MAECs) in an in vitro flow system. Average rolling velocity of the monocytic cell line WEHI 274.1 was increased on ICAM-1-deficient MAECs compared with wild-type MAECs, both with and without TNF-α stimulation. High-temporal-resolution analysis provided insights into the underlying basis for these differences. Without TNF-α stimulation, average rolling velocity was slower on wild-type than on ICAM-1-deficient endothelium because of brief (<1 s) pauses. On TNF-α-stimulated ICAM-1-deficient endothelium, cells rolled faster because of transient accelerations, producing “jerky” rolling. Firm adhesion to ICAM-1-deficient MAECs was significantly reduced compared with wild-type MAECs, although the number of rolling cells was similar. These results demonstrate directly that ICAM-1 affects rolling velocity by stabilizing leukocyte rolling.

scholarly journals Revealing the time course of laser evoked potential habituation by high temporal resolution analysis

2021 ◽  
Author(s):  
D. Kersebaum ◽  
S.‐C. Fabig ◽  
M. Sendel ◽  
A. C. Muntean ◽  
R. Baron ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Time Course ◽  
Evoked Potential ◽  
High Temporal Resolution ◽  
Resolution Analysis

Leukocyte adhesion in local versus hemorrhage-induced ischemia

1992 ◽  
Vol 263 (3) ◽  
pp. H810-H815 ◽  
Author(s):  
M. A. Perry ◽  
D. N. Granger
Keyword(s):  
Endothelial Cell ◽  
Leukocyte Adhesion ◽  
Ischemia Reperfusion ◽  
Leukocyte Rolling ◽  
Leukocyte Adherence ◽  
Rolling Velocity ◽  
Local Ischemia ◽  
Cell Adhesive ◽  
Local Restriction ◽  
Adhesive Interactions

The objective of this study was to compare the leukocyte-endothelial cell adhesive interactions elicited in postcapillary venules by either local ischemia-reperfusion or hemorrhage-reperfusion. Leukocyte rolling, adherence, and emigration were monitored in cat mesenteric venules exposed to an 85% reduction in blood flow (induced by either hemorrhage or local restriction of arterial inflow) for 1 h, followed by 1 h reperfusion. Leukocyte-endothelial cell interactions, venular diameter, and red blood cell velocity were measured during baseline, ischemia, and reperfusion periods. Both local and hemorrhage-induced ischemia reperfusion caused a reduction in leukocyte rolling velocity and increases in leukocyte adherence and emigration. Quantitatively, the adherence and emigration responses in both ischemia models were nearly identical. However, the two models differed in their response to immunoneutralization of the leukocyte adhesion glycoprotein CD11/CD18 with monoclonal antibody (MAb) IB4. The MAb had a more profound effect in attenuating leukocyte adherence and emigration in the local ischemia model. These results indicate that different factors may contribute to leukocyte-endothelial cell adhesive interactions observed in local vs. systemic models of ischemia-reperfusion.

Lipopolysaccharide Binds Platelet Toll-Like Receptor 4 and Mediates the Activation of Phagocytes in the Reticuloendothelial System (RES): A Novel Mechanism of Host Immunity.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1093-1093
Author(s):  
John W. Semple ◽  
Rukhsana Aslam ◽  
Edwin R. Speck ◽  
John Freedman
Keyword(s):  
Flow Cytometric Analysis ◽  
Reticuloendothelial System ◽  
Tlr4 Expression ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Tnf Α ◽  
Multiple Copies ◽  
Factor Α

Abstract Toll-like receptors (TLR) comprise a family of transmembrane proteins characterized by multiple copies of leucine-rich repeats in the extracellular domain and an IL-1 receptor motif in their cytoplasmic domain. The TLR family is a phylogenetically conserved mediator of innate immunity that is essential for microbial recognition and the stimulation of adaptive immune responses. Recently, our laboratory demonstrated that TLR4 expression on platelets was responsible for lipopolysaccharide (LPS)-mediated thrombocytopenia and tumour necrosis factor-α production in vivo (Aslam et al. Blood107:637, 2006). To understand the mechanism of how platelet TLR4 may mediate RES activation, platelets from wild type (WT) and TLR4 knockout mice were incubated with various concentrations of LPS in vitro, washed extensively and transfused into WT mice. Results suggest that only the WT platelets could significantly stimulate TNF-α production in vivo. In vitro flow cytometric analysis of phagocytosis by the monocytic cell line THP-1 demonstrated that platelet TLR4 could efficiently present LPS to THP-1 cells and stimulated them to engulf the LPS-coated platelets. The phagocytosis of the platelets was correlated to elevated levels of intracellular TNF-α production in the THP-1 cells. These results suggest that platelets, via TLR4 expression, can act as initial sentinels of the innate immune system by presenting bacterial products such as LPS to phagocytes of the RES.

scholarly journals TNF-α activation of arterioles and venules alters distribution and levels of ICAM-1 and affects leukocyte-endothelial cell interactions

2006 ◽  
Vol 291 (5) ◽  
pp. H2116-H2125 ◽  
Author(s):  
Ronen Sumagin ◽  
Ingrid H. Sarelius
Keyword(s):  
Spatial Distribution ◽  
Endothelial Cell ◽  
Inflammatory Responses ◽  
Leukocyte Adhesion ◽  
Leukocyte Rolling ◽  
Cremaster Muscle ◽  
Rolling Velocity ◽  
Tnf Α ◽  
Arteriolar Wall ◽  
Microvessel Wall

The observation that leukocyte-endothelial cell (EC) interactions are localized to specific regions on the microvessel wall suggests that adhesion molecule distribution is not uniform. We investigated ICAM-1 distribution and leukocyte-EC interactions in blood-perfused microvessels (<80 μm) in cremaster muscle of anesthetized mice, using intravital confocal microscopy and immunofluorescent labeling. Variability of ICAM-1 expression directly determines leukocyte adhesion distribution within the venular microcirculation and contributes to leukocyte rolling in arterioles during inflammation. The number of rolling interactions increased with ICAM-1 intensity ( r2 = 0.69, P < 0.05), and rolling velocity was lower in regions of higher ICAM-1 intensity. In controls, venular ICAM-1 expression was approximately twofold higher than in arterioles. After TNF-α treatment, ICAM-1 expression was significantly increased, 2.8 ± 0.2-fold in arterioles and 1.7 ± 0.2-fold in venules ( P < 0.05). ICAM-1 expression on activated arteriolar ECs only reached the level of control venular ICAM-1. Arteriolar but not venular ECs underwent redistribution of ICAM-1 among cells; some cells increased and some decreased ICAM-1 expression, magnifying the variability of ICAM-1. TNF-α treatment increased the length of bright fluorescent regions per unit vessel length (42%, control; 70%, TNF-α) along the arteriolar wall, whereas no significant change was observed in venules (60%, control; 63%, TNF-α). The spatial distribution and expression levels of adhesion molecules in the microcirculation determine the timing and placement of leukocyte interactions and hence significantly impact the inflammatory response. That arteriolar ECs respond to TNF-α by upregulation of ICAM-1, although in a different way compared with venules, suggests an explicit role for arterioles in inflammatory responses.

scholarly journals Differentiation of Monocytes to Macrophages Primes Cells for Lipopolysaccharide Stimulation via Accumulation of Cytoplasmic Nuclear Factor κB

1999 ◽  
Vol 67 (11) ◽  
pp. 5573-5578 ◽  
Author(s):  
Shogo Takashiba ◽  
Thomas E. Van Dyke ◽  
Salomon Amar ◽  
Yoji Murayama ◽  
Aubrey W. Soskolne ◽  
...  
Keyword(s):  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Blood Monocytes ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Necrosis Factor Alpha ◽  
Lps Challenge ◽  
Differentiated Cells ◽  
Human Monocytic Cell Line ◽  
Tnf Α

ABSTRACT During infection, circulating blood monocytes migrate from the vasculature to the extravascular compartments where they mature into tissue macrophages. The maturation process prepares the cell to actively participate in the inflammatory and the immune responses, and many transcription factors have been found to be involved. Here we report on a novel role for nuclear factor κB (NF-κB) in this process. Its accumulation in the cytoplasm of differentiated macrophages is responsible for the enhanced ability of the cell to respond to lipopolysaccharide (LPS) stimulation, as determined by tumor necrosis factor alpha (TNF-α) secretion. Differentiation of the human monocytic cell line THP-1 into macrophage-like cells was induced by exposure of the cells to phorbol myristate acetate. DNA-bindable NF-κB was not detected in the cytoplasm of undifferentiated THP-1 cells but accumulated in the cytoplasm of the cells following differentiation. No TNF-α was detected in the media of resting differentiated and nondifferentiated THP-1 cells. Stimulation with LPS of differentiated cells induced the production of higher levels of TNF-α than stimulation of nondifferentiated cells. This hyperresponsiveness to LPS was found in the mRNA and secreted TNF-α levels. Furthermore, stimulation with LPS induced the translocation of NF-κB from the cytoplasm into the nucleus. This translocation process was more rapid in the differentiated cells than in the nondifferentiated cells, and the resultant accumulated levels of NF-κB in the nucleus were higher. The DNA-bindable NF-κB was identified as a heterodimer of p65 and p50. The results suggest that NF-κB accumulation in the cytoplasm during maturation of monocytes to macrophages primes the cells for enhanced responsiveness to LPS and results in the rapid secretion of inflammatory mediators, such as TNF-α, by mature macrophages following LPS challenge.

Comparison of SP-A and LPS effects on the THP-1 monocytic cell line

2000 ◽  
Vol 279 (1) ◽  
pp. L110-L117 ◽  
Author(s):  
Mingchen Song ◽  
David S. Phelps
Keyword(s):  
Protein A ◽  
Surfactant Protein ◽  
Polymyxin B ◽  
Inhibitory Effects ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Monocytic Cells ◽  
Similar Treatment ◽  
Tnf Α ◽  
Factor Α

Surfactant protein A (SP-A) increases production of proinflammatory cytokines by monocytic cells, including THP-1 cells, as does lipopolysaccharide (LPS). Herein we report differences in responses to these agents. First, polymyxin B inhibits the LPS response but not the SP-A response. Second, SP-A-induced increases in tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-8 are reduced by >60% if SP-A is preincubated with Survanta (200 μg/ml) for 15 min before addition to THP-1 cells. However, the LPS effects on TNF-α and IL-8 are inhibited by <20% and the effect on IL-1β by <50%. Third, at Survanta levels of 1 mg/ml, SP-A-induced responses are reduced by >90%, and although the inhibitory effects on LPS action increase, they still do not reach those seen with SP-A. Finally, we tested whether SP-A could induce tolerance as LPS does. Pretreatment of THP-1 cells with LPS inhibits their response to subsequent LPS treatment 24 h later, including TNF-α, IL-1β, and IL-8. Similar treatment with SP-A reduces TNF-α, but IL-1β and IL-8 are further increased by the second treatment with SP-A rather than inhibited as with LPS. Thus, whereas both SP-A and LPS stimulate cytokine production, their mechanisms differ with respect to inhibition by surfactant lipids and in ability to induce tolerance.

scholarly journals Palmitate-Induced MMP-9 Expression in the Human Monocytic Cells is Mediated through the TLR4-MyD88 Dependent Mechanism

2016 ◽  
Vol 39 (3) ◽  
pp. 889-900 ◽  
Author(s):  
Sardar Sindhu ◽  
Areej Al-Roub ◽  
Merin Koshy ◽  
Reeby Thomas ◽  
Rasheed Ahmad
Keyword(s):  
Underlying Mechanism ◽  
Positive Control ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Monocytic Cells ◽  
Metabolic Inflammation ◽  
Human Monocytic Cell Line ◽  
Tnf Α ◽  
Human Monocytic Cell

Background/Aims: Obese individuals are known to have increased Matrix metalloproteinase (MMP)-9 plasma levels and MMP-9 is reported to play an important role in obesity-associated adipose tissue inflammation. Since in obesity, the levels of circulatory saturated free fatty acid (FFA) palmitate (palimitic acid) are increased and modulate the expression of inflammatory mediators, the role of palmitate in the regulation of MMP-9 remains unclear. Methods: Human monocytic cell line THP-1 and primary monocytes were stimulated with palmitate and TNF-α (positive control). MMP-9 expression was assessed with real time RT-PCR and ELISA. Signaling pathways were studied by using THP-1-XBlue™ cells, THP-1-XBlue™-defMyD cells, anti-TLR4 mAb and TLR4 siRNA. Phosphorylation of NF-kB and c-Jun was analyzed by Western blotting. Results: Here, we provide the evidence that palmitate induces MMP-9 expression at both mRNA (THP-1: 6.8 ± 1.2 Fold; P = 0.01; Primary monocytes: 5.9 ± 0.7 Fold; P = 0.0003) and protein (THP1: 1116 ±14 pg/ml; P<0.001; Primary monocytes: 1426 ± 13.8; P = 0.0005) levels in human monocytic cells. Palmitate-induced MMP-9 secretion was markedly suppressed by neutralizing anti-TLR-4 antibody (P < 0.05). Furthermore, genetic silencing of TLR4 by siRNA also significantly abrogated the palmitate-induced up-regulation of MMP-9. Additionally, MyD88-/- THP-1 cells did not express MMP-9 in response to palmitate treatment. Increased NF-κB/AP-1 activity (P<0.05) was also observed in palmitate-treated THP-1 cells. Conclusion: Altogether, these results show that palmitate induces TLR4-dependent activation of MMP-9 gene expression, which requires the recruitment of MyD88 leading to activation of NF-kB/AP-1 transcription factors. Thus, our findings suggest that the palmitate-induced MMP-9 secretion might be an underlying mechanism of its increased levels in obesity and related metabolic inflammation.

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