| 1. |
- Baumeister, Ulf, et al.
(författare)
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Association of Csk to VE-cadherin and inhibition of cell proliferation
- 2005
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Ingår i: EMBO Journal. - : Wiley-Blackwell Publishing Inc.. - 0261-4189 .- 1460-2075. ; 24:9, s. 1686-1695
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Tidskriftsartikel (refereegranskat)abstract
- Vascular endothelial cadherin (VE-cadherin) mediates contact inhibition of cell growth in quiescent endothelial cell layers. Searching for proteins that could be involved in VE-cadherin signaling, we found the cytosolic C-terminal Src kinase (Csk), a negative regulator of Src family kinases. We show that Csk binds via its SH2 domain to the phosphorylated tyrosine 685 of VE-cadherin. VE-cadherin recruits Csk to cell contacts and both proteins can be co-precipitated from cell lysates of transfected cells and endothelial cells. Association of VE-cadherin and Csk in endothelial cells increased with increasing cell density. CHO cells expressing the tyrosine replacement mutant VE-cadherin-Y685F grow to higher cell densities than cells expressing wild-type VE-cadherin. Overexpression of Csk in these cells under an inducible promoter inhibits cell proliferation in the presence and absence of VE-cadherin, but not in the presence of VE-cadherin-Y685F. Reduction of Csk expression by RNA interference enhances endothelial cell proliferation. Our results suggest that the phosphorylated tyrosine residue 685 of VE-cadherin and probably the binding of Csk to this site are involved in inhibition of cell growth triggered by cell density.
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| 2. |
- Bentley, Katie, et al.
(författare)
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The role of differential VE-cadherin dynamics in cell rearrangement during angiogenesis
- 2014
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Ingår i: Nature Cell Biology. - : Springer Science and Business Media LLC. - 1465-7392 .- 1476-4679. ; 16:4, s. 309-321
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial cells show surprising cell rearrangement behaviour during angiogenic sprouting; however, the underlying mechanisms and functional importance remain unclear. By combining computational modelling with experimentation, we identify that Notch/VEGFR-regulated differential dynamics of VE-cadherin junctions drive functional endothelial cell rearrangements during sprouting. We propose that continual flux in Notch signalling levels in individual cells results in differential VE-cadherin turnover and junctional-cortex protrusions, which powers differential cell movement. In cultured endothelial cells, Notch signalling quantitatively reduced junctional VE-cadherin mobility. In simulations, only differential adhesion dynamics generated long-range position changes, required for tip cell competition and stalk cell intercalation. Simulation and quantitative image analysis on VE-cadherin junctional patterning in vivo identified that differential VE-cadherin mobility is lost under pathological high VEGF conditions, in retinopathy and tumour vessels. Our results provide a mechanistic concept for how cells rearrange during normal sprouting and how rearrangement switches to generate abnormal vessels in pathologies.
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| 3. |
- Brandau, Oliver, et al.
(författare)
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Chondromodulin I Is Dispensable during Enchondral Ossification and Eye Development.
- 2002
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Ingår i: Molecular and Cellular Biology. - 0270-7306. ; 22:18, s. 6627-6635
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Tidskriftsartikel (refereegranskat)abstract
- Chondromodulin I (chm-I), a type II transmembrane protein, is highly expressed in the avascular zones of cartilage but is downregulated in the hypertrophic region, which is invaded by blood vessels during enchondral ossification. In vitro and in vivo assays with the purified protein have shown chondrocyte-modulating and angiogenesis-inhibiting functions. To investigate chm-I function in vivo, we generated transgenic mice lacking chm-I mRNA and protein. Null mice are viable and fertile and show no morphological changes. No abnormalities in vascular invasion and cartilage development were detectable. No evidence was found for a compensating function of tendin, a recently published homologue highly expressed in tendons and also, at low levels, in cartilage. Furthermore, no differences in the expression of other angiogenic or antiangiogenic factors such as transforming growth factor beta1 (TGF-beta1), TGF-beta2, TGF-beta3, fibroblast growth factor 2, and vascular endothelial growth factor were found. The surprising lack of phenotype in the chm-I-deficient mice suggests either a different function for chm-I in vivo than has been proposed or compensatory changes in uninvestigated angiogenic or angiogenesis-inhibiting factors. Further analysis using double-knockout technology will be necessary to analyze the function of chm-I in the complex process of enchondral ossification.
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| 4. |
- Frye, Maike, et al.
(författare)
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EphrinB2-EphB4 signalling provides Rho-mediated homeostatic control of lymphatic endothelial cell junction integrity
- 2020
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Ingår i: eLIFE. - : eLife Sciences Publications, Ltd. - 2050-084X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial integrity is vital for homeostasis and adjusted to tissue demands. Although fluid uptake by lymphatic capillaries is a critical attribute of the lymphatic vasculature, the barrier function of collecting lymphatic vessels is also important by ensuring efficient fluid drainage as well as lymph node delivery of antigens and immune cells. Here, we identified the transmembrane ligand EphrinB2 and its receptor EphB4 as critical homeostatic regulators of collecting lymphatic vessel integrity. Conditional gene deletion in mice revealed that EphrinB2/EphB4 signalling is dispensable for blood endothelial barrier function, but required for stabilization of lymphatic endothelial cell (LEC) junctions in different organs of juvenile and adult mice. Studies in primary human LECs further showed that basal EphrinB2/EphB4 signalling controls junctional localisation of the tight junction protein CLDN5 and junction stability via Rac1/Rho-mediated regulation of cytoskeletal contractility. EphrinB2/EphB4 signalling therefore provides a potential therapeutic target to selectively modulate lymphatic vessel permeability and function.
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| 5. |
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| 6. |
- Haegerling, Rene, et al.
(författare)
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Distinct roles of VE-cadherin for development and maintenance of specific lymph vessel beds
- 2018
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Ingår i: EMBO Journal. - : WILEY. - 0261-4189 .- 1460-2075. ; 37:22
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial cells line blood and lymphatic vessels and form intercellular junctions, which preserve vessel structure and integrity. The vascular endothelial cadherin, VE-cadherin, mediates endothelial adhesion and is indispensible for blood vessel development and permeability regulation. However, its requirement for lymphatic vessels has not been addressed. During development, VE-cadherin deletion in lymphatic endothelial cells resulted in abortive lymphangiogenesis, edema, and prenatal death. Unexpectedly, inducible postnatal or adult deletion elicited vessel bed-specific responses. Mature dermal lymph vessels resisted VE-cadherin loss and maintained button junctions, which was associated with an upregulation of junctional molecules. Very different, mesenteric lymphatic collectors deteriorated and formed a strongly hyperplastic layer of lymphatic endothelial cells on the mesothelium. This massive hyperproliferation may have been favored by high mesenteric VEGF-C expression and was associated with VEGFR-3 phosphorylation and upregulation of the transcriptional activator TAZ. Finally, intestinal lacteals fragmented into cysts or became highly distended possibly as a consequence of the mesenteric defects. Taken together, we demonstrate here the importance of VE-cadherin for lymphatic vessel development and maintenance, which is however remarkably vessel bed-specific.
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| 7. |
- Hayashi, Makoto, et al.
(författare)
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VE-PTP regulates VEGFR2 activity in stalk cells to establish endothelial cell polarity and lumen formation
- 2013
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 1672-
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Tidskriftsartikel (refereegranskat)abstract
- Vascular endothelial growth factor (VEGF) guides the path of new vessel sprouts by inducing VEGF receptor-2 activity in the sprout tip. In the stalk cells of the sprout, VEGF receptor-2 activity is downregulated. Here, we show that VEGF receptor-2 in stalk cells is dephosphorylated by the endothelium-specific vascular endothelial-phosphotyrosine phosphatase (VE-PTP). VE-PTP acts on VEGF receptor-2 located in endothelial junctions indirectly, via the Angiopoietin-1 receptor Tie2. VE-PTP inactivation in mouse embryoid bodies leads to excess VEGF receptor-2 activity in stalk cells, increased tyrosine phosphorylation of VE-cadherin and loss of cell polarity and lumen formation. Vessels in ve-ptp(-/-) teratomas also show increased VEGF receptor-2 activity and loss of endothelial polarization. Moreover, the zebrafish VE-PTP orthologue ptp-rb is essential for polarization and lumen formation in intersomitic vessels. We conclude that the role of Tie2 in maintenance of vascular quiescence involves VE-PTP-dependent dephosphorylation of VEGF receptor-2, and that VEGF receptor-2 activity regulates VE-cadherin tyrosine phosphorylation, endothelial cell polarity and lumen formation.
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| 8. |
- Jin, Yi, et al.
(författare)
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Tyrosine-protein kinase Yes controls endothelial junctional plasticity and barrier integrity by regulating VE-cadherin phosphorylation and endocytosis
- 2022
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Ingår i: Nature Cardiovascular Research. - : Springer Nature. - 2731-0590. ; 1:12, s. 1156-1173
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Tidskriftsartikel (refereegranskat)abstract
- Vascular endothelial (VE)-cadherin in endothelial adherens junctions is an essential component of the vascular barrier, critical for tissue homeostasis and implicated in diseases such as cancer and retinopathies. Inhibitors of Src cytoplasmic tyrosine kinase have been applied to suppress VE-cadherin tyrosine phosphorylation and prevent excessive leakage, edema and high interstitial pressure. Here we show that the Src-related Yes tyrosine kinase, rather than Src, is localized at endothelial cell (EC) junctions where it becomes activated in a flow-dependent manner. EC-specific Yes1 deletion suppresses VE-cadherin phosphorylation and arrests VE-cadherin at EC junctions. This is accompanied by loss of EC collective migration and exaggerated agonist-induced macromolecular leakage. Overexpression of Yes1 causes ectopic VE-cadherin phosphorylation, while vascular leakage is unaffected. In contrast, in EC-specific Src deficiency, VE-cadherin internalization is maintained and leakage is suppressed. In conclusion, Yes-mediated phosphorylation regulates constitutive VE-cadherin turnover, thereby maintaining endothelial junction plasticity and vascular integrity.
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| 9. |
- Li, Xiujuan, et al.
(författare)
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VEGFR2 pY949 signalling regulates adherens junction integrity and metastatic spread
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The specific role of VEGFA-induced permeability and vascular leakage in physiology and pathology has remained unclear. Here we show that VEGFA-induced vascular leakage depends on signalling initiated via the VEGFR2 phosphosite Y949, regulating dynamic c-Src and VE-cadherin phosphorylation. Abolished Y949 signalling in the mouse mutant Vegfr2(Y949F/Y949F) leads to VEGFA-resistant endothelial adherens junctions and a block in molecular extravasation. Vessels in Vegfr2(Y949F/Y949F) mice remain sensitive to inflammatory cytokines, and vascular morphology, blood pressure and flow parameters are normal. Tumour-bearing Vegfr2(Y949F/Y949F) mice display reduced vascular leakage and oedema, improved response to chemotherapy and, importantly, reduced metastatic spread. The inflammatory infiltration in the tumour micro-environment is unaffected. Blocking VEGFA-induced disassembly of endothelial junctions, thereby suppressing tumour oedema and metastatic spread, may be preferable to full vascular suppression in the treatment of certain cancer forms.
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| 10. |
- Mapunda, Josephine A., et al.
(författare)
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VE-cadherin in arachnoid and pia mater cells serves as a suitable landmark for in vivo imaging of CNS immune surveillance and inflammation
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Meninges cover the surface of the brain and spinal cord and contribute to protection and immune surveillance of the central nervous system (CNS). How the meningeal layers establish CNS compartments with different accessibility to immune cells and immune mediators is, however, not well understood. Here, using 2-photon imaging in female transgenic reporter mice, we describe VE-cadherin at intercellular junctions of arachnoid and pia mater cells that form the leptomeninges and border the subarachnoid space (SAS) filled with cerebrospinal fluid (CSF). VE-cadherin expression also marked a layer of Prox1+ cells located within the arachnoid beneath and separate from E-cadherin+ arachnoid barrier cells. In vivo imaging of the spinal cord and brain in female VE-cadherin-GFP reporter mice allowed for direct observation of accessibility of CSF derived tracers and T cells into the SAS bordered by the arachnoid and pia mater during health and neuroinflammation, and detection of volume changes of the SAS during CNS pathology. Together, the findings identified VE-cadherin as an informative landmark for in vivo imaging of the leptomeninges that can be used to visualize the borders of the SAS and thus potential barrier properties of the leptomeninges in controlling access of immune mediators and immune cells into the CNS during health and neuroinflammation. How the leptomeninges establish CNS compartments with different accessibility to immune cells and immune mediators remains unknown. Here, the authors show junctional localization of VE-cadherin in arachnoid and pia mater cells, which allows to visualize potential barrier properties of the leptomeninges in vivo.
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| 11. |
- Ninchoji, Takeshi, et al.
(författare)
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eNOS-induced vascular barrier disruption in retinopathy by c-Src activation and tyrosine phosphorylation of VE-cadherin
- 2021
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Ingår i: eLIFE. - : eLife Sciences Publications Ltd. - 2050-084X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background:Hypoxia and consequent production of vascular endothelial growth factor A (VEGFA) promote blood vessel leakiness and edema in ocular diseases. Anti-VEGFA therapeutics may aggravate hypoxia; therefore, therapy development is needed.Methods:Oxygen-induced retinopathy was used as a model to test the role of nitric oxide (NO) in pathological neovascularization and vessel permeability. Suppression of NO formation was achieved chemically using L-NMMA, or genetically, in endothelial NO synthase serine to alanine (S1176A) mutant mice.Results:Suppression of NO formation resulted in reduced retinal neoangiogenesis. Remaining vascular tufts exhibited reduced vascular leakage through stabilized endothelial adherens junctions, manifested as reduced phosphorylation of vascular endothelial (VE)-cadherin Y685 in a c-Src-dependent manner. Treatment with a single dose of L-NMMA in established retinopathy restored the vascular barrier and prevented leakage.Conclusions:We conclude that NO destabilizes adheren junctions, resulting in vascular hyperpermeability, by converging with the VEGFA/VEGFR2/c-Src/VE-cadherin pathway.
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| 12. |
- Petri, Björn, et al.
(författare)
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Endothelial LSP1 is involved in endothelial dome formation, minimizing vascular permeability changes during neutrophil transmigration in vivo
- 2011
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 117:3, s. 942-952
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Tidskriftsartikel (refereegranskat)abstract
- The endothelium actively participates in neutrophil migration out of the vasculature via dynamic, cytoskeleton-dependent rearrangements leading to the formation of transmigratory cups in vitro, and to domes that completely surround the leukocyte in vivo. Leukocyte-specific protein 1 (LSP1), an F-actin-binding protein recently shown to be in the endothelium, is critical for effective transmigration, although the mechanism has remained elusive. Herein we show that endothelial LSP1 is expressed in the nucleus and cytosol of resting endothelial cells and associates with the cytoskeleton upon endothelial activation. Two-photon microscopy revealed that endothelial LSP1 was crucial for the formation of endothelial domes in vivo in response to neutrophil chemokine keratinocyte-derived chemokine (KC) as well as in response to endogenously produced chemokines stimulated by cytokines (tumor necrosis factor α [TNFα] or interleukin-1β [IL-1β]). Endothelial domes were significantly reduced in Lsp1-/- compared with wildtype (WT) mice. Lsp1-/- animals not only showed impaired neutrophil emigration after KC and TNFα stimulation, but also had disproportionate increases in vascular permeability. We demonstrate that endothelial LSP1 is recruited to the cytoskeleton in inflammation and plays an important role in forming endothelial domes thereby regulating neutrophil transendothelial migration. The permeability data may underscore the physiologic relevance of domes and the role for LSP1 in endothelial barrier integrity.
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| 13. |
- Pruenster, Monika, et al.
(författare)
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Extracellular MRP8/14 is a regulator of β2 integrin-dependent neutrophil slow rolling and adhesion.
- 2015
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Myeloid-related proteins (MRPs) 8 and 14 are cytosolic proteins secreted from myeloid cells as proinflammatory mediators. Currently, the functional role of circulating extracellular MRP8/14 is unclear. Our present study identifies extracellular MRP8/14 as an autocrine player in the leukocyte adhesion cascade. We show that E-selectin-PSGL-1 interaction during neutrophil rolling triggers Mrp8/14 secretion. Released MRP8/14 in turn activates a TLR4-mediated, Rap1-GTPase-dependent pathway of rapid β2 integrin activation in neutrophils. This extracellular activation loop reduces leukocyte rolling velocity and stimulates adhesion. Thus, we identify Mrp8/14 and TLR4 as important modulators of the leukocyte recruitment cascade during inflammation in vivo.
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| 14. |
- Smith, Ross O., et al.
(författare)
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Vascular permeability in retinopathy is regulated by VEGFR2 Y949 signaling to VE-cadherin
- 2020
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Ingår i: eLIFE. - : ELIFE SCIENCES PUBLICATIONS LTD. - 2050-084X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Edema stemming from leaky blood vessels is common in eye diseases such as agerelated macular degeneration and diabetic retinopathy. Whereas therapies targeting vascular endothelial growth factor A (VEGFA) can suppress leakage, side-effects include vascular rarefaction and geographic atrophy. By challenging mouse models representing different steps in VEGFA/VEGF receptor 2 (VEGFR2)-induced vascular permeability, we show that targeting signaling downstream of VEGFR2 pY949 limits vascular permeability in retinopathy induced by high oxygen or by laser-wounding. Although suppressed permeability is accompanied by reduced pathological neoangiogenesis in oxygen-induced retinopathy, similarly sized lesions leak less in mutant mice, separating regulation of permeability from angiogenesis. Strikingly, vascular endothelial (VE)-cadherin phosphorylation at the Y685, but not Y658, residue is reduced when VEGFR2 pY949 signaling is impaired. These findings support a mechanism whereby VE-cadherin Y685 phosphorylation is selectively associated with excessive vascular leakage. Therapeutically, targeting VEGFR2-regulated VE-cadherin phosphorylation could suppress edema while leaving other VEGFR2-dependent functions intact.
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| 15. |
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| 16. |
- Vestweber, Dietmar, et al.
(författare)
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Report from the 2023 workshop on endothelial permeability, edema and inflammation
- 2023
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Ingår i: Nature Cardiovascular Research. - : Springer Nature. - 2731-0590. ; 2:12, s. 1120-1124
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A key consequence of increased and sustained vascular permeability in several inflammatory and cardiovascular disorders is the development of interstitial protein-rich proinflammatory edema. This response remains poorly understood mechanistically and its potential adverse effect on local and systemic diseases is often underestimated. To discuss current findings and identify crucial unresolved questions, a workshop was held in Berlin from 12-15 April 2023. Key topics that were discussed included regulation of endothelial cell junctions, neutrophil-dependent vascular leakage, resolution of edema, exemplar diseases, and anti-edema therapies. This report is a summary of the meeting.
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| 17. |
- Wan, Ming Xiu, et al.
(författare)
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Leukocyte rolling is exclusively mediated by P-selectinin colonic venules.
- 2002
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Ingår i: British Journal of Pharmacology. - : Wiley. - 1476-5381 .- 0007-1188. ; 135:7, s. 1749-1756
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Tidskriftsartikel (refereegranskat)abstract
- 1. The objective of the present study was to examine the role of the endothelial selectins (i.e. P- and E-selectin) in leukocyte-endothelium interactions in colonic venules by use of intravital microscopy. 2. Balb/c mice were exposed to dextran sodium sulphate (DSS) in the drinking water for 5 days or treated intraperitoneally (i.p.) with tumour necrosis factor-alpha (TNF-alpha) for 3 h. 3. In DSS-treated mice, mRNA of both P- and E-selectin were expressed and leukocyte rolling and adhesion was increased to 27+/-3 cells min(-1) and 36+/-8 cells mm(-1), respectively. An anti-P-selectin antibody abolished DSS-induced leukocyte rolling, whereas an antibody against E-selectin had no effect. Established leukocyte adhesion was insensitive to inhibition of the selectins. 4. DSS markedly increased production of TNF-alpha in the colon. TNF-alpha increased leukocyte rolling to 22+/-3 cells min(-1) and adhesion to 45+/-4 cells mm(-1). Only inhibition of P-selectin significantly reduced (>94%) leukocyte rolling provoked by TNF-alpha. Leukocyte adhesion was not changed by late anti-P-selectin antibody treatment. In contrast, pretreatment with the anti-P-selectin antibody not only abolished leukocyte rolling but also completely inhibited firm adhesion in response to TNF-alpha. 5. This study demonstrates that P-selectin plays an important role in leukocyte rolling in colonic venules, both in experimental colitis and when stimulated with TNF-alpha. Moreover, P-selectin-dependent leukocyte rolling was found to be a precondition for TNF-alpha-induced firm adhesion. Thus, these findings suggest that P-selectin may be a key target to reduce pathological recruitment of inflammatory cells in the colon.
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| 18. |
- Wu, Chuan, et al.
(författare)
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Endothelial basement membrane laminin alpha 5 selectively inhibits T lymphocyte extravasation into the brain
- 2009
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 15:5, s. 519-527
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Tidskriftsartikel (refereegranskat)abstract
- Specific inhibition of the entry of encephalitogenic T lymphocytes into the central nervous system in multiple sclerosis would provide a means of inhibiting disease without compromising innate immune responses. We show here that targeting lymphocyte interactions with endothelial basement membrane laminins provides such a possibility. In mouse experimental autoimmune encephalomyelitis, T lymphocyte extravasation correlates with sites expressing laminin alpha 4 and small amounts of laminin alpha 5. In mice lacking laminin alpha 4, laminin alpha 5 is ubiquitously expressed along the vascular tree, resulting in marked and selective reduction of T lymphocyte infiltration into the brain and reduced disease susceptibility and severity. Vessel phenotype and immune response were not affected in these mice. Rather, laminin alpha 5 directly inhibited integrin alpha(6)beta(1)-mediated migration of T lymphocytes through laminin alpha 4. The data indicate that T lymphocytes use mechanisms distinct from other immune cells to penetrate the endothelial basement membrane barrier, permitting specific targeting of this immune cell population.
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