Control of leukocyte rolling velocity in TNF-α–induced inflammation by LFA-1 and Mac-1

Blood ◽  
2002 ◽  
Vol 99 (1) ◽  
pp. 336-341 ◽  
Author(s):  
Jessica L. Dunne ◽  
Christie M. Ballantyne ◽  
Arthur L. Beaudet ◽  
Klaus Ley

Previously it was shown that β2-integrins are necessary for slow leukocyte rolling in inflamed venules. In this study, mice that are deficient for either one of the β2-integrins, αLβ2 (LFA-1) or αMβ2 (Mac-1), were used to determine which of the β2-integrins are responsible for slowing rolling leukocytes. The cremaster muscles of these mice were treated with tumor necrosis factor-α and prepared for intravital microscopy. The average rolling velocities in venules were elevated in LFA-1−/−mice (11.0 ± 0.7 μm/s) and Mac-1−/− mice (10.1 ± 1.1 μm/s) compared to wild-type mice (4.8 ± 0.3 μm/s;P < .05), but were lower than in CD18−/−mice (28.5 ± 2.1 μm/s). When both LFA-1 and Mac-1 were absent or blocked, rolling velocity became dependent on shear rate and approached that of CD18−/− mice. In addition, leukocyte adhesion efficiency was decreased in LFA-1−/− mice to near CD18−/− levels, but decreased only slightly in Mac-1−/− mice. Thus, both LFA-1 and Mac-1 contribute to slowing down rolling leukocytes, although LFA-1 is more important than Mac-1 in efficiently inducing firm adhesion.

1999 ◽  
Vol 189 (6) ◽  
pp. 939-948 ◽  
Author(s):  
Ali Hafezi-Moghadam ◽  
Klaus Ley

The velocity of rolling leukocytes is thought to be determined by the expression of adhesion molecules and the prevailing wall shear stress. Here, we investigate whether rapid cleavage of L-selectin may be an additional physiologic regulatory parameter of leukocyte rolling. A unique protease in the membrane of leukocytes cleaves L-selectin after activation, resulting in L-selectin shedding. The hydroxamic acid–based metalloprotease inhibitor KD-IX-73-4 completely prevented L-selectin shedding in vitro and significantly decreased the rolling velocity of leukocytes in untreated wild-type C57BL/6 mice from 55 to 35 μm/s in vivo. When E-selectin was expressed on the endothelium (tumor necrosis factor [TNF]-α treatment 2.5–3 h before the experiment), rolling velocity was 4 μm/s and did not change after the application of KD-IX-73-4. However, KD-IX-73-4 decreased mean rolling velocity by 29% from 23 to 16 μm/s in E-selectin–deficient mice treated with TNF-α. The reduction of velocity caused by KD-IX-73-4 was immediate (<5 s) after injection of KD-IX-73-4 as shown by a novel method using a local catheter. These results establish a role for L-selectin shedding in regulating leukocyte rolling velocity in vivo.


Blood ◽  
2006 ◽  
Vol 109 (5) ◽  
pp. 1938-1944 ◽  
Author(s):  
Unni M. Chandrasekharan ◽  
Maria Siemionow ◽  
Murat Unsal ◽  
Lin Yang ◽  
Earl Poptic ◽  
...  

Abstract Tumor necrosis factor-α (TNF-α) binds to 2 distinct cell-surface receptors: TNF-α receptor-I (TNFR-I: p55) and TNF-α receptor-II (TNFR-II: p75). TNF-α induces leukocyte adhesion molecules on endothelial cells (ECs), which mediate 3 defined steps of the inflammatory response; namely, leukocyte rolling, firm adhesion, and transmigration. In this study, we have investigated the role of p75 in TNF-α–induced leukocyte adhesion molecules using cultured ECs derived from wild-type (WT), p75-null (p75−/−), or p55-null (p55−/−) mice. We observed that p75 was essential for TNF-α–induced E-selectin, vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule 1 (ICAM-1) expression. We also investigated the putative role of p75 in inflammation in vivo using an intravital microscopic approach with a mouse cremaster muscle model. TNF-α–stimulated leukocyte rolling, firm adhesion to ECs, and transmigration were dramatically reduced in p75−/− mice. Transplanted WT cremaster in p75−/− mice showed a robust leukocyte rolling and firm adhesion upon TNF-α activation, suggesting that the impairment in EC-leukocyte interaction in p75−/− mice is due to EC dysfunction. These results demonstrate, for the first time, that endothelial p75 is essential for TNF-α–induced leukocyte–endothelial-cell interaction. Our findings may contribute to the identification of novel p75-targeted therapeutic approaches for inflammatory diseases.


2006 ◽  
Vol 291 (5) ◽  
pp. H2116-H2125 ◽  
Author(s):  
Ronen Sumagin ◽  
Ingrid H. Sarelius

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.


1994 ◽  
Vol 266 (2) ◽  
pp. H637-H642 ◽  
Author(s):  
J. P. Gaboury ◽  
D. C. Anderson ◽  
P. Kubes

Intravital microscopy was used to monitor leukocyte adherence, flux, rolling velocity, and number of rolling leukocytes (flux/velocity) in venules 25–40 microns in diameter. The superoxide-generating system, hypoxanthine and xanthine oxidase (HX/XO), was infused into the mesenteric circulation in untreated animals or in animals pretreated with either catalase (a hydrogen peroxide scavenger), WEB-2086 [a platelet-activating factor (PAF) receptor antagonist], or monoclonal antibodies directed against adhesion molecules CD18 (CL26) or P-selectin (PB1.3). HX/XO infusion caused a decrease in leukocyte rolling velocity and an increase in the number of rolling and adherent leukocytes. WEB-2086 prevented the increase in leukocyte adhesion and markedly increased leukocyte rolling velocity. PB1.3 abolished the HX/XO-associated rise in the flux of rolling leukocytes and proportionally decreased the number of adherent leukocytes. CL26 abolished HX/XO-induced leukocyte adhesion and also reduced the number of rolling leukocytes. In conclusion, P-selectin mediates the increased leukocyte flux induced by superoxide, whereas PAF and CD18 modulate leukocyte adhesion. PAF also reduces leukocyte rolling velocity, possibly as a result of CD18, but not P-selectin.


2001 ◽  
Vol 193 (7) ◽  
pp. 863-872 ◽  
Author(s):  
Ali Hafezi-Moghadam ◽  
Kennard L. Thomas ◽  
Alyson J. Prorock ◽  
Yuqing Huo ◽  
Klaus Ley

The physiologic role of L-selectin shedding is unknown. Here, we investigate the effect of L-selectin shedding on firm adhesion and transmigration. In a tumor necrosis factor α–induced model of inflammation, inhibition of L-selectin shedding significantly increased firm adhesion and transmigration by a lymphocyte function–associated antigen (LFA)-1 and intercellular adhesion molecule (ICAM)-1–dependent mechanism. We examined the quality of leukocyte rolling and L-selectin–mediated signaling. Blockade of L-selectin shedding significantly reduced the “jerkiness” of leukocyte rolling, defined as the variability of velocity over time. A low level of jerkiness was also observed in the rolling of microbeads conjugated with L-selectin, a model system lacking the mechanism for L-selectin shedding. Inhibition of L-selectin shedding potentiated activation of LFA-1 and Mac-1 induced by L-selectin cross-linking as shown by activation epitope expression and binding of ICAM-1–conjugated beads. We conclude that inhibition of L-selectin shedding increases leukocyte adhesion and transmigration by (a) increasing leukocyte exposure to the inflamed endothelium by decreasing jerkiness and (b) promoting leukocyte activation by outside-in signaling. These observations help to resolve the apparent discrepancy between the minor contribution of L-selectin to rolling and the significant leukocyte recruitment defect in L-selectin knockout mice.


2000 ◽  
Vol 279 (6) ◽  
pp. H2815-H2823 ◽  
Author(s):  
Charmaine B. S. Henry ◽  
Brian R. Duling

The endothelial luminal glycocalyx has been largely ignored as a target in vascular pathophysiology even though it occupies a key location. As a model of the inflammatory response, we tested the hypothesis that tumor necrosis factor-α (TNF-α) can alter the properties of the endothelial apical glycocalyx. In the intact hamster cremaster microcirculation, fluorescein isothiocyanate (FITC)-labeled Dextrans 70, 580, and 2,000 kDa are excluded from a region extending from the endothelial surface almost 0.5 μm into the lumen. This exclusion zone defines the boundaries of the glycocalyx. Red blood cells (RBC) under normal flow conditions are excluded from a region extending even farther into the lumen. The cremaster microcirculation was pretreated with topical or intrascrotal applications of TNF-α. After infusion of FITC-dextran, FITC-albumin, or FITC-immunoglubulin G (IgG) via a femoral cannula, microvessels were observed with bright-field and fluorescence microscopy to obtain estimates of the anatomic diameters and the widths of fluorescent tracer columns and of the RBC columns (means ± SE). After 2 h of intrascrotal TNF-α exposure, there was a significant increase in access of FITC-Dextrans 70 and 580 to the space bounded by the apical glycocalyx in arterioles, capillaries, and venules, but no significant change in access of FITC-Dextran 2,000. The effects of TNF-α could be observed as early as 20 min after the onset of topical application. TNF-α treatment also significantly increased the penetration rate of FITC-Dextran 40, FITC-albumin, and FITC-IgG into the glycocalyx and caused a significant increase in the intraluminal volume occupied by flowing RBC. White blood cell adhesion increased during TNF-α application, and we used the selectin antagonist fucoidan to attenuate leukocyte adhesion during TNF-α stimulation. This did not inhibit the TNF-α-mediated increase in permeation of the glycocalyx. These results show that proinflammatory cytokines can cause disruption of the endothelial apical glycocalyx, leading to an increased macromolecular permeation in the absence of an increase in leukocyte recruitment.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3573
Author(s):  
Lian-Chun Li ◽  
Zheng-Hong Pan ◽  
De-Sheng Ning ◽  
Yu-Xia Fu

Simonsinol is a natural sesqui-neolignan firstly isolated from the bark of Illicium simonsii. In this study, the anti-inflammatory activity of simonsinol was investigated with a lipopolysaccharide (LPS)-stimulated murine macrophages RAW264.7 cells model. The results demonstrated that simonsinol could antagonize the effect of LPS on morphological changes of RAW264.7 cells, and decrease the production of nitric oxide (NO), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) in LPS-stimulated RAW264.7 cells, as determined by Griess assay and enzyme-linked immunosorbent assay (ELISA). Furthermore, simonsinol could downregulate transcription of inducible nitric oxide synthase (iNOS), TNF-α, and IL-6 as measured by reverse transcription polymerase chain reaction (RT-PCR), and inhibit phosphorylation of the alpha inhibitor of NF-κB (IκBα) as assayed by Western blot. In conclusion, these data demonstrate that simonsinol could inhibit inflammation response in LPS-stimulated RAW264.7 cells through the inactivation of the nuclear transcription factor kappa-B (NF-κB) signaling pathway.


2019 ◽  
Vol 88 ◽  
pp. 149-150 ◽  
Author(s):  
Erkoseoglu Ilknur ◽  
Kadioglu Mine ◽  
Cavusoglu Irem ◽  
Sisman Mulkiye ◽  
Aran Turhan ◽  
...  

2005 ◽  
Vol 60 (4) ◽  
pp. 471-475 ◽  
Author(s):  
Barbara Orzeszko ◽  
Tomasz Świtaj ◽  
Anna B. Jakubowska-Mućka ◽  
Witold Lasek ◽  
Andrzej Orzeszko ◽  
...  

Certain adamantylated heterocycles were previously shown to enhance the secretion of tumor necrosis factor alpha (TNF-α) by murine melanoma cells that have been transduced with the gene for human TNF-α and constitutively expressed this cytokine. The stimulatory potency of those compounds depended, among other factors, on the structure of the linker between the adamantyl residue and the heterocyclic core. In the present study, a series of (1-adamantyl)alkylsulfanyl derivatives of heterocyclic compounds was prepared by alkylation of the corresponding thioheterocyles. Of the novel adamantylalkylthio compounds tested in the aforementioned cell line, 2-(2-adamantan-1-ylethylsulfanyl)- 4-methyl-pyrimidine was found to be the most active


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