scholarly journals Endothelial IQGAP1 regulates leukocyte transmigration by directing the LBRC to the site of diapedesis

2019 ◽  
Vol 216 (11) ◽  
pp. 2582-2601 ◽  
Author(s):  
David P. Sullivan ◽  
Prarthana J. Dalal ◽  
Fanny Jaulin ◽  
David B. Sacks ◽  
Geri Kreitzer ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Scaffold Protein ◽  
Interacting Proteins ◽  
Calponin Homology Domain ◽  
Directed Movement ◽  
Lateral Border ◽  
Leukocyte Transmigration ◽  
Calponin Homology ◽  
First Time

Transendothelial migration (TEM) of leukocytes across the endothelium is critical for inflammation. In the endothelium, TEM requires the coordination of membrane movements and cytoskeletal interactions, including, prominently, recruitment of the lateral border recycling compartment (LBRC). The scaffold protein IQGAP1 was recently identified in a screen for LBRC-interacting proteins. Knockdown of endothelial IQGAP1 disrupted the directed movement of the LBRC and substantially reduced leukocyte TEM. Expression of truncated IQGAP1 constructs demonstrated that the calponin homology domain is required for IQGAP1 localization to endothelial borders and that the IQ domain, on the same IQGAP1 polypeptide, is required for its function in TEM. This is the first reported function of IQGAP1 requiring two domains to be present on the same polypeptide. Additionally, we show for the first time that IQGAP1 in the endothelium is required for efficient TEM in vivo. These findings reveal a novel function for IQGAP1 and demonstrate that IQGAP1 in endothelial cells facilitates TEM by directing the LBRC to the site of TEM.

Cyclosporine triggers endoplasmic reticulum stress in endothelial cells: a role for endothelial phenotypic changes and death

2009 ◽  
Vol 296 (1) ◽  
pp. F160-F169 ◽  
Author(s):  
Nicolas Bouvier ◽  
Jean Pierre Flinois ◽  
Jerome Gilleron ◽  
François-Ludovic Sauvage ◽  
Christophe Legendre ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Calcineurin Inhibitors ◽  
Solid Organ ◽  
Mesenchymal Transition ◽  
Phenotypic Changes ◽  
Endothelial To Mesenchymal Transition ◽  
First Time

Calcineurin inhibitors cyclosporine and tacrolimus are effective immunosuppressants, but both substances have the same intrinsic nephrotoxic potential that adversely affects allograft survival in renal transplant patients and causes end-stage renal disease in other solid organ or bone marrow transplant recipients. Endothelial cells are the first biological interface between drugs and the kidney, and calcineurin inhibitors may influence endothelial function and viability in a number of ways. Notably, endothelial cells have recently been shown to contribute to the accumulation of interstitial fibroblasts in nonrenal models, through endothelial-to-mesenchymal transition. Here we demonstrate that cyclosporine, but not tacrolimus or its metabolites, induces morphological and phenotypic endothelial changes suggestive of a partial endothelial-to-mesenchymal transition in human umbilical arterial endothelial cells. We identify for the first time a contingent of interstitial myofibroblasts that coexpress endothelial markers in rat kidneys treated with cyclosporine, suggesting that endothelial-to-mesenchymal transition could occur in vivo. Finally, our findings suggest that endoplasmic reticulum stress triggered by cyclosporine induces endothelial cells to undergo endothelial phenotypic changes suggestive of a partial endothelial-to-mesenchymal transition, whereas salubrinal partially preserves the endothelial phenotype. Inversely, tacrolimus does not induce endothelial-to-mesenchymal transition or endoplasmic reticulum stress. In conclusion, this study demonstrates for the first time that cyclosporine, and not tacrolimus, induces endoplasmic reticulum stress in endothelial cells. Our findings also suggest that endoplasmic reticulum stress contributes to endothelial cell death and phenotypic changes similar to a partial endothelial-to-mesenchymal transition.

scholarly journals Leukocyte transmigration requires kinesin-mediated microtubule-dependent membrane trafficking from the lateral border recycling compartment

2008 ◽  
Vol 205 (4) ◽  
pp. 951-966 ◽  
Author(s):  
Zahra Mamdouh ◽  
Geri E. Kreitzer ◽  
William A. Muller
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Membrane Trafficking ◽  
Molecular Motors ◽  
Lateral Border ◽  
Leukocyte Transmigration ◽  
Surface Molecules ◽  
Adaptive Immune ◽  
Platelet Endothelial Cell Adhesion ◽  
Kinesin Family

Diapedesis of leukocytes across endothelial cells is a crucial step in both the innate and adaptive immune responses. Surface molecules on leukocytes and endothelial cells critical for diapedesis have been identified, but the mechanisms underlying this process are not understood. Homophilic interaction between platelet/endothelial cell adhesion molecule (PECAM) on leukocytes and PECAM at the endothelial border triggers targeted recycling of membrane from a reticulum localized close to the endothelial cell lateral border. This membrane surrounds the transmigrating leukocyte (Mamdouh, Z., X. Chen, L.M. Pierini, F.R. Maxfield, and W.A. Muller. 2003. Nature. 421:748–753). How this process occurs and whether it is required for diapedesis independent of PECAM are not known. We now report that targeted recycling from this lateral border recycling compartment (LBRC) is required for diapedesis, is mediated by kinesin family molecular motors, and requires normally functioning endothelial microtubules. Selective disruption of microtubules or inhibition of kinesin motor domain blocked targeted recycling and diapedesis of monocytes. Furthermore, targeted recycling of membrane from the LBRC was required for transmigration of lymphocytes, which migrate independently of PECAM. Thus, trafficking of membrane from the LBRC to surround leukocytes may be a general requirement for migration of leukocytes across the endothelial cell border. Furthermore, these data provide the first demonstration of a role for endothelial microtubules and kinesins in promoting diapedesis, and a mechanism to explain targeted recycling.

scholarly journals Plasmodium falciparum-infected erythrocyte receptor(s) for CD36 and thrombospondin are restricted to knobs on the erythrocyte surface.

1992 ◽  
Vol 40 (9) ◽  
pp. 1419-1422 ◽  
Author(s):  
K Nakamura ◽  
T Hasler ◽  
K Morehead ◽  
R J Howard ◽  
M Aikawa
Keyword(s):  
Endothelial Cells ◽  
Plasmodium Falciparum ◽  
Cerebral Malaria ◽  
Vascular Occlusion ◽  
Cerebral Microvessels ◽  
Erythrocyte Surface ◽  
Infected Rbcs ◽  
First Time

Adherence of Plasmodium falciparum-infected RBCs (PRBC) to endothelial cells causes PRBC sequestration in cerebral microvessels and is considered to be a major contributor to the pathogenesis of cerebral malaria. Both CD36 and thrombospondin (TSP) are glycoproteins that mediate PRBC adherence to endothelial cells in vitro. Because they are both expressed on the surface of endothelial cells, they probably contribute to PRBC sequestration and vascular occlusion in vivo. By applying affinity labeling of receptor binding sites with purified ligands, we showed for the first time that both CD36 and TSP can bind independently to the PRBC surface and that the PRBC receptor(s) for CD36 and TSP are localized specifically to the electron-dense knob protrusions of the PRBC surface. These findings may help in efforts to develop a malaria vaccine to prevent cerebral malaria.

scholarly journals The Nucleolar Protein Nucleophosmin Is Physiologically Secreted by Endothelial Cells in Response to Stress Exerting Proangiogenic Activity Both In Vitro and In Vivo

2021 ◽  
Vol 22 (7) ◽  
pp. 3672
Author(s):  
Anna Di Carlo ◽  
Sara Beji ◽  
Silvia Palmerio ◽  
Mario Picozza ◽  
Marco D’Agostino ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Biological Effects ◽  
Intercellular Adhesion Molecule ◽  
Serum Starvation ◽  
Cell Necrosis ◽  
Intercellular Adhesion Molecule 1 ◽  
First Time

Nucleophosmin (NPM), a nucleolar multifunctional phosphoprotein, acts as a stress sensor in different cell types. NPM can be actively secreted by inflammatory cells, however its biology on endothelium remains unexplored. In this study, we show for the first time that NPM is secreted by human vein endothelial cells (HUVEC) in the early response to serum deprivation and that NPM acts as a pro-inflammatory and angiogenic molecule both in vitro and in vivo. Accordingly, 24 h of serum starvation condition induced NPM relocalization from the nucleus to cytoplasm. Interestingly, NPM was increasingly excreted in HUVEC-derived conditioned media in a time dependent fashion upon stress conditions up to 24 h. The secretion of NPM was unrelated to cell necrosis within 24 h. The treatment with exogenous and recombinant NPM (rNPM) enhanced migration as well as the Intercellular Adhesion Molecule 1 (ICAM-1) but not Vascular cell adhesion protein 1 (VCAM-1) expression and it did not affect cell proliferation. Notably, in vitro tube formation by Matrigel assay was significantly increased in HUVEC treated with rNPM compared to controls. This result was confirmed by the in vivo injection of Matrigel plug assay upon stimulation with rNPM, displaying significant enhanced number of functional capillaries in the plugs. The stimulation with rNPM in HUVEC was also associated to the increased expression of master genes regulating angiogenesis and migration, including Vascular Endothelial Growth Factor-A (VEGF-A), Hepatocyte Growth Factor (HGF), Stromal derived factor-1 (SDF-1), Fibroblast growth factor-2 (FGF-2), Platelet Derived Growth Factor-B (PDGF-B), and Matrix metallopeptidase 9 (MMP9). Our study demonstrates for the first time that NPM is physiologically secreted by somatic cells under stress condition and in the absence of cell necrosis. The analysis of the biological effects induced by NPM mainly related to a pro-angiogenic and inflammatory activity might suggest an important autocrine/paracrine role for NPM in the regulation of both phenomena.

A CD99-related antigen on endothelial cells mediates neutrophil but not lymphocyte extravasation in vivo

Blood ◽  
2007 ◽  
Vol 109 (12) ◽  
pp. 5327-5336 ◽  
Author(s):  
M. Gabriele Bixel ◽  
Björn Petri ◽  
Alexander G. Khandoga ◽  
Andrej Khandoga ◽  
Karen Wolburg-Buchholz ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Surface Protein ◽  
Cell Aggregation ◽  
Transendothelial Migration ◽  
Leukocyte Transmigration ◽  
Leukocyte Antigen ◽  
Neutrophil Extravasation ◽  
Endothelial Surface

Abstract CD99 is a long-known leukocyte antigen that does not belong to any of the known protein families. It was recently found on endothelial cells, where it mediates transendothelial migration of human monocytes and lymphocyte recruitment into inflamed skin in the mouse. Here, we show that CD99L2, a recently cloned, widely expressed antigen of unknown function with moderate sequence homology to CD99, is expressed on mouse leukocytes and endothelial cells. Using antibodies, we found that CD99L2 and CD99 are involved in transendothelial migration of neutrophils in vitro and in the recruitment of neutrophils into inflamed peritoneum. Intravital and electron microscopy of cremaster venules revealed that blocking CD99L2 inhibited leukocyte transmigration through the vessel wall (diapedesis) at the level of the perivascular basement membrane. We were surprised to find that, in contrast to CD99, CD99L2 was not relevant for the extravasation of lymphocytes into inflamed tissue. Although each protein promoted cell aggregation of transfected cells, endothelial CD99 and CD99L2 participated in neutrophil extravasation independent of these proteins on neutrophils. Our results establish CD99L2 as a new endothelial surface protein involved in neutrophil extravasation. In addition, this is the first evidence for a role of CD99 and CD99L2 in the process of leukocyte diapedesis in vivo.

scholarly journals Immunotargeting and cloning of two CD34 variants exhibiting restricted expression in adult rat endothelia in vivo

2009 ◽  
Vol 297 (2) ◽  
pp. L251-L262 ◽  
Author(s):  
Jacqueline E. Testa ◽  
Adrian Chrastina ◽  
Phil Oh ◽  
Yan Li ◽  
Halina Witkiewicz ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasma Membranes ◽  
Complete Sequence ◽  
Hematopoietic Stem ◽  
Adult Rat ◽  
Cell Plasma ◽  
Mouse Tissues ◽  
First Time ◽  
Cd34 Expression

Mapping protein expression of endothelial cells (EC) in vivo is fundamental to understanding cellular function and may yield new tissue-selective targets. We have developed a monoclonal antibody, MAb J120, to a protein expressed primarily in rat lung and heart endothelium. The antigen was identified as CD34, a marker of hematopoietic stem cells and global marker of endothelial cells in human and mouse tissues. PCR-based cloning identified two CD34 variant proteins, full length and truncated, both of which are expressed on luminal endothelial cell plasma membranes (P) isolated from lung. Truncated CD34 predominated in heart P, and neither variant was detected in P from kidney or liver. CD34 in lung was readily accessible to125I-J120 inoculated intravenously, and immunohistochemistry showed strong CD34 expression in lung EC. Few microvessels stained in heart and kidney, and no CD34 was detected in vessels of other organs or in lymphatics. We present herein the first complete sequence of a rat CD34 variant and show for the first time that the encoded truncated variant is endogenously expressed on EC in vivo. We also demonstrate that CD34 expression in rat EC, unlike mouse and human, is restricted in its distribution enabling quite specific lung targeting in vivo.

scholarly journals Freezing adhesion molecules in a state of high-avidity binding blocks eosinophil migration.

1993 ◽  
Vol 178 (1) ◽  
pp. 279-284 ◽  
Author(s):  
T W Kuijpers ◽  
E P Mul ◽  
M Blom ◽  
N L Kovach ◽  
F C Gaeta ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Platelet Activating Factor ◽  
Inflammatory Cells ◽  
High Avidity ◽  
Directed Movement ◽  
Eosinophil Migration ◽  
Beta 1 Integrin

Leukocyte extravasation is mediated by multiple interactions of adhesive surface structures with ligands on endothelial cells and matrix components. The functional role of beta 1 (CD29) integrins (or very late antigen [VLA] proteins) in eosinophil migration across polycarbonate filters was examined under several in vitro conditions. Eosinophil migration induced by the chemoattractant C5a or platelet-activating factor was fully inhibited by monoclonal antibody (mAb) 8A2, a recently characterized "activating" CD29 mAb. However, inhibition by mAb 8A2 was observed only under filter conditions that best reflected the in vivo situation, i.e., when the eosinophils migrated over filters preincubated with the extracellular matrix (ECM) protein fibronectin (FN), or when the filters were covered with confluent monolayers of cultured human umbilical vein endothelial cells (HUVEC). When bare untreated filters were used, mAb 8A2 had no effect, whereas the C5a-directed movement was prevented by CD18 mAb. Studies with alpha-subunit (CD49)-specific mAbs indicated that the integrins VLA-4 and -5 mediated migration across FN-preincubated filters, and VLA-2, -4, -5, and -6 were involved in eosinophil migration through filters covered with HUVEC. In contrast with the activating CD29 mAb 8A2, a combination of blocking CD49 mAbs or the nonactivating but blocking CD29 mAb AIIB2 failed to inhibit completely eosinophil migration over FN-preincubated or HUVEC-covered filters. mAb 8A2 stimulated binding to FN but not to HUVEC. Moreover, eosinophil migration over FN-preincubated or HUVEC-covered filters was significantly inhibited by anti-connecting segment 1 (CS-1) mAbs, as well as the soluble CS-1 peptide (unlike migration across bare untreated filters). Thus, inhibition of eosinophil migration by mAb 8A2 depended upon the presence of ECM proteins and not upon the presence of HUVEC per se. In conclusion, "freezing" adhesion receptors of the beta 1 integrin family into their high-avidity binding state by the activating CD29 mAb 8A2 results in a complete inhibition of eosinophil migration under physiological conditions. Hence, activation of beta 1 integrin-mediated cell adhesion may represent a new approach to prevent influx of inflammatory cells.

scholarly journals Enhanced endothelial motility and multicellular sprouting is mediated by the scaffold protein TKS4

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Elod Mehes ◽  
Monika Barath ◽  
Marton Gulyas ◽  
Edina Bugyik ◽  
Miklos Geiszt ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Motility ◽  
Umbilical Vein ◽  
Time Lapse ◽  
Scaffold Protein ◽  
Key Factor ◽  
Membrane Type ◽  
Umbilical Vein Endothelial Cells ◽  
The Impact

Abstract Endothelial cell motility has fundamental role in vasculogenesis and angiogenesis during developmental or pathological processes. Tks4 is a scaffold protein known to organize the cytoskeleton of lamellipodia and podosomes, and thus modulating cell motility and invasion. In particular, Tks4 is required for the localization and activity of membrane type 1-matrix metalloproteinase, a key factor for extracellular matrix (ECM) cleavage during cell migration. While its role in transformed cells is well established, little is known about the function of Tks4 under physiological conditions. In this study we examined the impact of Tks4 gene silencing on the functional activity of primary human umbilical vein endothelial cells (HUVEC) and used time-lapse videomicrosopy and quantitative image analysis to characterize cell motility phenotypes in culture. We demonstrate that the absence of Tks4 in endothelial cells leads to impaired ECM cleavage and decreased motility within a 3-dimensional ECM environment. Furthermore, absence of Tks4 also decreases the ability of HUVEC cells to form multicellular sprouts, a key requirement for angiogenesis. To establish the involvement of Tks4 in vascular development in vivo, we show that loss of Tks4 leads sparser vasculature in the fetal chorion in the Tks4-deficient ‘nee’ mouse strain.

Resveratrol Reduces Matrix Metalloproteinase-2 Activity Induced by Oxygen-Glucose Deprivation and Reoxygenation in Human Cerebral Microvascular Endothelial Cells

2012 ◽  
Vol 82 (4) ◽  
pp. 267-274 ◽  
Author(s):  
Zahide Cavdar ◽  
Mehtap Y. Egrilmez ◽  
Zekiye S. Altun ◽  
Nur Arslan ◽  
Nilgun Yener ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Neurovascular Unit ◽  
Glucose Deprivation ◽  
Matrix Metalloproteinase 2 ◽  
Microvascular Endothelial Cells ◽  
Oxygen Glucose Deprivation ◽  
Microvascular Endothelial

The main pathophysiology in cerebral ischemia is the structural alteration in the neurovascular unit, coinciding with neurovascular matrix degradation. Among the human matrix metalloproteinases (MMPs), MMP-2 and -9, known as gelatinases, are the key enzymes for degrading type IV collagen, which is the major component of the basal membrane that surrounds the cerebral blood vessel. In the present study, we investigated the effects of resveratrol on cytotoxicity, reactive oxygen species (ROS), and gelatinases (MMP-2 and -9) in human cerebral microvascular endothelial cells exposed to 6 hours of oxygen-glucose deprivation and a subsequent 24 hours of reoxygenation with glucose (OGD/R), to mimic ischemia/reperfusion in vivo. Lactate dehydrogenase increased significantly, in comparison to that in the normoxia group. ROS was markedly increased in the OGD/R group, compared to normoxia. Correspondingly, ROS was significantly reduced with 50 μM of resveratrol. The proMMP-2 activity in the OGD/R group showed a statistically significant increase from the control cells. Resveratrol preconditioning decreased significantly the proMMP-2 in the cells exposed to OGD/R in comparison to that in the OGD/R group. Our results indicate that resveratrol regulates MMP-2 activity induced by OGD/R via its antioxidant effect, implying a possible mechanism related to the neuroprotective effect of resveratrol.

An Electron Microscopic Study of Platelet Thrombus Formation in the Rabbit with Particular Regard to 5-Hydroxytryptamine Release

1967 ◽  
Vol 18 (03/04) ◽  
pp. 592-604 ◽  
Author(s):  
H. R Baumgartner ◽  
J. P Tranzer ◽  
A Studer
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vessel Wall ◽  
Thrombus Formation ◽  
Endothelial Damage ◽  
Electron Microscopic ◽  
Rabbit Ear ◽  
Basement Lamina ◽  
Platelet Thrombus

SummaryElectron microscopic and histologic examination of rabbit ear vein segments 4 and 30 min after slight endothelial damage have yielded the following findings :1. Platelets do not adhere to damaged endothelial cells.2. If the vessel wall is denuded of the whole endothelial cell, platelets adhere to the intimai basement lamina as do endothelial cells.3. The distance between adherent platelets as well as endothelial cells and intimai basement lamina measures 10 to 20 mµ, whereas the distance between aggregated platelets is 30 to 60 mµ.4. 5-hydroxytryptamine (5-HT) is released from platelets during viscous metamorphosis at least in part as 5-HT organelles.It should be noted that the presence of collagen fibers is not necessary for platelet thrombus formation in vivo.

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