The Expression of Microfilament-Associated Cell-Cell Contacts in Brain Endothelial Cells Is Modified by IFN-β1a (Rebif®)

2004 ◽  
Vol 24 (12) ◽  
pp. 711-716 ◽  
Author(s):  
Michael Harzheim ◽  
Manuela Stepien-Mering ◽  
Rolf Schröder ◽  
Stephan Schmidt
Keyword(s):  
Endothelial Cells ◽  
Brain Endothelial Cells ◽  
Cell Contacts ◽  
Cell Cell

The Expression of Microfilament-Associated Cell-Cell Contacts in Brain Endothelial Cells Is Modified by IFN-β1a (Rebif®)

2004 ◽  
Vol 24 (12) ◽  
pp. 711-716
Author(s):  
Michael Harzheim ◽  
Manuela Stepien-Mering ◽  
Rolf Schröder ◽  
Stephan Schmidt
Keyword(s):  
Endothelial Cells ◽  
Brain Endothelial Cells ◽  
Cell Contacts ◽  
Cell Cell

Occludin as a possible determinant of tight junction permeability in endothelial cells

1997 ◽  
Vol 110 (14) ◽  
pp. 1603-1613 ◽  
Author(s):  
T. Hirase ◽  
J.M. Staddon ◽  
M. Saitou ◽  
Y. Ando-Akatsuka ◽  
M. Itoh ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
Transmembrane Protein ◽  
Neural Tissue ◽  
Brain Endothelial Cells ◽  
Regulation Of Expression ◽  
Cell Contacts ◽  
Rat Brain Endothelial Cells ◽  
Tight Junction Permeability ◽  
Cell Cell

Endothelial cells provide a crucial interface between blood and tissue environments. Free diffusion of substances across endothelia is prevented by the endothelial tight junction, the permeability of which varies enormously depending on tissue. Endothelial cells of the blood-brain barrier possess tight junctions of severely limited permeability, whereas those of non-neural tissue are considerably leakier, but the molecular basis for this difference is not clear. Occludin is a major transmembrane protein localizing at the tight junction. In this study, we show, by immunocytochemistry, that occludin is present at high levels and is distributed continuously at cell-cell contacts in brain endothelial cells. In contrast, endothelial cells of non-neural tissue have a much lower expression of occludin, which is distributed in a discontinuous fashion at cell-cell contacts. The apparent differences in occludin expression levels were directly confirmed by immunoblotting. The differences in occludin protein were reflected at the message level, suggesting transcriptional regulation of expression. We also show that occludin expression is developmentally regulated, being low in rat brain endothelial cells at postnatal day 8 but clearly detectable at post-natal day 70. Our data indicate that regulation of occludin expression may be a crucial determinant of the tight junction permeability properties of endothelial cells in different tissues.

Cell confluence regulates tyrosine phosphorylation of adherens junction components in endothelial cells

1997 ◽  
Vol 110 (17) ◽  
pp. 2065-2077 ◽  
Author(s):  
M.G. Lampugnani ◽  
M. Corada ◽  
P. Andriopoulou ◽  
S. Esser ◽  
W. Risau ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tyrosine Phosphorylation ◽  
Adherens Junction ◽  
Cell Junctions ◽  
Molecular Organization ◽  
Beta Catenin ◽  
Cell Contacts ◽  
Cell Type Specific ◽  
Dynamic Structures ◽  
Cell Cell

In src- and ras-transformed cells, tyrosine phosphorylation of adherens junction (AJ) components is related to impairment of cell-cell adhesion. In this paper we report that in human endothelial cells (EC), tyrosine phosphorylation of AJ can be a physiological process regulated by cell density. Immunofluorescence analysis revealed that a phosphotyrosine (P-tyr) antibody could stain cell-cell junctions only in sparse or loosely confluent EC, while the staining was markedly reduced in tightly confluent cultures. This process was reversible, since on artificial wounding of EC monolayers, the cells at the migrating front reacquired P-tyr labelling at cell contacts. In EC, the major cadherin at intercellular AJ is the cell-type-specific VE-cadherin. We therefore analyzed whether this molecule was at least in part responsible for the changes in P-tyr content at cell junctions. Tyrosine phosphorylation of VE-cadherin, beta-catenin and p120, occurred in looser AJ, i.e. in recently confluent cells, and was notably reduced in tightly confluent cultures. Changes in P-tyr content paralleled changes in the molecular organization of AJ. VE-cadherin was mostly associated with beta-catenin and p120 in loose EC monolayers, while in long-confluent cells, these two catenins were largely replaced by plakoglobin. Inhibition of P-tyr phosphatases (PTPases) by PV markedly augmented the P-tyr content of VE-cadherin, which bound p120 and beta-catenin more efficiently, but not plakoglobin. Transfection experiments in CHO cells showed that p120 could bind to a VE-cadherin cytoplasmic region different from that responsible for beta-catenin binding, and PV stabilized this association. Overall these data indicate that endothelial AJ are dynamic structures that can be affected by the state of confluence of the cells. Tyrosine phosphorylation of VE-cadherin and its association to p120 and beta-catenin characterizes early cell contacts, while the formation of mature and cytoskeleton-connected junctions is accompanied by dephosphorylation and plakoglobin association.

scholarly journals Identification of Fer Tyrosine Kinase Localized on Microtubules as a Platelet Endothelial Cell Adhesion Molecule-1 Phosphorylating Kinase in Vascular Endothelial Cells

2003 ◽  
Vol 14 (9) ◽  
pp. 3553-3564 ◽  
Author(s):  
Naoko Kogata ◽  
Michitaka Masuda ◽  
Yuji Kamioka ◽  
Akiko Yamagishi ◽  
Akira Endo ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Adhesion Molecule ◽  
Intracellular Signaling ◽  
Vascular Endothelial Cells ◽  
Expression Cloning ◽  
Vascular Endothelial ◽  
Cell Contacts ◽  
Cell Cell

Platelet endothelial adhesion molecule-1 (PECAM-1) is a part of intercellular junctions and triggers intracellular signaling cascades upon homophilic binding. The intracellular domain of PECAM-1 is tyrosine phosphorylated upon homophilic engagement. However, it remains unclear which tyrosine kinase phosphorylates PECAM-1. We sought to isolate tyrosine kinases responsible for PECAM-1 phosphorylation and identified Fer as a candidate, based on expression cloning. Fer kinase specifically phosphorylated PECAM-1 at the immunoreceptor tyrosine-based inhibitory motif. Notably, Fer induced tyrosine phosphorylation of SHP-2, which is known to bind to the immunoreceptor tyrosine-based inhibitory motif of PECAM-1, and Fer also induced tyrosine phosphorylation of Gab1 (Grb2-associated binder-1). Engagement-dependent PECAM-1 phosphorylation was inhibited by the overexpression of a kinase-inactive mutant of Fer, suggesting that Fer is responsible for the tyrosine phosphorylation upon PECAM-1 engagement. Furthermore, by using green fluorescent protein-tagged Fer and a time-lapse fluorescent microscope, we found that Fer localized at microtubules in polarized and motile vascular endothelial cells. Fer was dynamically associated with growing microtubules in the direction of cell-cell contacts, where p120catenin, which is known to associate with Fer, colocalized with PECAM-1. These results suggest that Fer localized on microtubules may play an important role in phosphorylation of PECAM-1, possibly through its association with p120catenin at nascent cell-cell contacts.

Thrombopoietin Stimulates the Formation of Endothelial Cell-Cell Contacts and Activates the Small GTPase Rap1.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3713-3713
Author(s):  
Marloes R. Tijssen ◽  
Franca di Summa ◽  
Anne-Marieke van Stalborch ◽  
C. Ellen Van der Schoot ◽  
Jaap D. van Buul ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Electrical Resistance ◽  
Umbilical Vein ◽  
Small Gtpase ◽  
Endothelial Monolayer ◽  
Impedance Sensing ◽  
Cell Contacts ◽  
Umbilical Vein Endothelial Cells ◽  
Cell Cell

Abstract In addition to hematopoietic cells, the receptor for thrombopoietin (Tpo), c-Mpl, is expressed on human umbilical vein endothelial cells (HUVEC). In this study, we demonstrated that Mpl mRNA and protein can also be detected in immortalized human bone marrow endothelial cells (HBMEC). Furthermore, it was investigated whether Tpo affects endothelial monolayer integrity by either cell spreading or cell-cell contacts. By continuously monitoring the electrical resistance of freshly plated HUVEC or HBMEC with ECIS (electric cell-substrate impedance sensing), we observed a significant increase in the electrical resistance when endothelial cells were treated with 100 ng/ml of Tpo just prior to seeding, as shown in the figure below. This increase in electrical resistance was not due to increased cell adhesion or proliferation of the endothelial cells. However, a significant increase in initial spreading could be detected. Besides its effect on spreading, Tpo increased the electrical resistance of a confluent endothelial monolayer when compared to untreated monolayers. This indicates that Tpo promotes the formation of endothelial cell-cell contacts. Indeed, a decrease in immunostaining levels of phosphotyrosine could be observed in monolayers treated with Tpo. Also the junctional protein VE-cadherin showed diminished co-localization with phosphotyrosine staining when cells were treated with Tpo. The small GTPase Rap1 plays an important role in the formation of endothelial cell-cell contacts. In a pull-down experiment, using RalGDS as bait for active Rap1, we could demonstrate that Tpo transiently activates Rap1 in HUVEC. Thus, these results may put Tpo forward as a regulator of endothelial cell-cell contacts, possibly after vascular damage and subsequent release of Tpo by activated platelets. To our knowledge, Tpo is the first cytokine exerting this effect on endothelial cells. Figure Figure

scholarly journals Molecular cloning of CD31, a putative intercellular adhesion molecule closely related to carcinoembryonic antigen.

1990 ◽  
Vol 171 (6) ◽  
pp. 2147-2152 ◽  
Author(s):  
D L Simmons ◽  
C Walker ◽  
C Power ◽  
R Pigott
Keyword(s):  
Endothelial Cells ◽  
Carcinoembryonic Antigen ◽  
Adhesion Molecule ◽  
Umbilical Vein ◽  
Sequence Similarity ◽  
Intercellular Adhesion ◽  
Intercellular Adhesion Molecule ◽  
Cdna Clones ◽  
Cell Contacts ◽  
Cell Cell

cDNA clones encoding CD31 have been isolated by transient expression. The sequence of CD31 expressed on human umbilical vein endothelial cells (HUVEC) is identical to that expressed on the monocyte-like cell line HL60. In HUVEC. CD31 is concentrated in regions of cell-cell contacts. CD31 is a member of the Ig superfamily and is most closely related to the carcinoembryonic antigen CEA, consisting of four contiguous C2 domains. The localization of CD31 to regions of cell-cell contacts, and the sequence similarity to CEA, a known intercellular adhesion molecule (ICAM), strongly suggest that CD31 may function as an ICAM, possibly mediating endothelial cell-cell contacts and also promoting interactions between leukocytes and endothelial cells.

scholarly journals Integration of Endothelial Cells in Multicellular Spheroids Prevents Apoptosis and Induces Differentiation

1998 ◽  
Vol 143 (5) ◽  
pp. 1341-1352 ◽  
Author(s):  
Thomas Korff ◽  
Hellmut G. Augustin
Keyword(s):  
Endothelial Cells ◽  
Three Dimensional ◽  
Embryonic Stem ◽  
Multicellular Spheroids ◽  
Survival Factors ◽  
Cell Contacts ◽  
Survival Factor ◽  
Cell Culture Systems ◽  
Polarized Surface ◽  
Cell Cell

Single endothelial cells (EC) seeded in suspension culture rapidly undergo apoptosis. Addition of survival factors, such as VEGF and FGF-2, does not prevent apoptosis of suspended EC. However, when cells are allowed to establish cell–cell contacts, they become responsive to the activities of survival factors. These observations have led to the development of a three-dimensional spheroid model of EC differentiation. EC spheroids remodel over time to establish a differentiated surface layer of EC and a center of unorganized EC that subsequently undergo apoptosis. Surface EC become quiescent, establish firm cell–cell contacts, and can be induced to express differentiation antigens (e.g., induction of CD34 expression by VEGF). In contrast, the unorganized center spheroid cells undergo apoptosis if they are not rescued by survival factors. The responsiveness to the survival factor activities of VEGF and FGF-2 was not dependent on cell shape changes since it was retained after cytochalasin D treatment. Taken together, these findings characterize survival factor requirements of unorganized EC and indicate that polarized surface EC differentiate to become independent of exogenous survival factors. Furthermore, they demonstrate that spheroid cell culture systems are useful not just for the study of tumor cells and embryonic stem cells but also for the analysis of differentiated functions of nontransformed cells.

scholarly journals Formation of a PKCζ/β-catenin complex in endothelial cells promotes angiopoietin-1–induced collective directional migration and angiogenic sprouting

Blood ◽  
2012 ◽  
Vol 120 (16) ◽  
pp. 3371-3381 ◽  
Author(s):  
Malika Oubaha ◽  
Michelle I. Lin ◽  
Yoran Margaron ◽  
Dominic Filion ◽  
Emily N. Price ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Leading Edge ◽  
Cell Junctions ◽  
Endothelial Cell Migration ◽  
Directional Migration ◽  
Cell Contacts ◽  
Angiopoietin 1 ◽  
Cell Cell

Abstract Angiogenic sprouting requires that cell-cell contacts be maintained during migration of endothelial cells. Angiopoietin-1 (Ang-1) and vascular endothelial growth factor act oppositely on endothelial cell junctions. We found that Ang-1 promotes collective and directional migration and, in contrast to VEGF, induces the formation of a complex formed of atypical protein kinase C (PKC)-ζ and β-catenin at cell-cell junctions and at the leading edge of migrating endothelial cells. This complex brings Par3, Par6, and adherens junction proteins at the front of migrating cells to locally activate Rac1 in response to Ang-1. The colocalization of PKCζ and β-catenin at leading edge along with PKCζ-dependent stabilization of cell-cell contacts promotes directed and collective endothelial cell migration. Consistent with these results, down-regulation of PKCζ in endothelial cells alters Ang-1–induced sprouting in vitro and knockdown in developing zebrafish results in intersegmental vessel defects caused by a perturbed directionality of tip cells and by loss of cell contacts between tip and stalk cells. These results reveal that PKCζ and β-catenin function in a complex at adherens junctions and at the leading edge of migrating endothelial cells to modulate collective and directional migration during angiogenesis.

ICAM-3 Activation Modulates Cell-Cell Contacts of Human Bone Marrow Endothelial Cells

2004 ◽  
Vol 41 (1) ◽  
pp. 28-37 ◽  
Author(s):  
J.D. van Buul ◽  
F.P.J. Mul ◽  
C.E. van der Schoot ◽  
P.L. Hordijk
Keyword(s):  
Bone Marrow ◽  
Endothelial Cells ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Cell Contacts ◽  
Cell Cell

Quantitative Phenotyping of Cell–Cell Junctions to Evaluate ZO-1 Presentation in Brain Endothelial Cells

2019 ◽  
Vol 47 (7) ◽  
pp. 1675-1687 ◽  
Author(s):  
Kelsey M. Gray ◽  
Dakota B. Katz ◽  
Erica G. Brown ◽  
Kimberly M. Stroka
Keyword(s):  
Endothelial Cells ◽  
Cell Junctions ◽  
Brain Endothelial Cells ◽  
Cell Cell
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