Thrombomodulin is essential for maintaining quiescence in vascular endothelial cells
Thrombomodulin (TM) is a thrombin receptor on endothelial cells that is involved in promoting activation of the anticoagulant protein C pathway during blood coagulation. TM also exerts protective anti-inflammatory properties through a poorly understood mechanism. In this study, we investigated the i...
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| Published in: | Proceedings of the National Academy of Sciences - PNAS Vol. 118; no. 11 |
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| Main Authors: | , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
United States
16.03.2021
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| Subjects: | |
| ISSN: | 1091-6490, 1091-6490 |
| Online Access: | Get more information |
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| Summary: | Thrombomodulin (TM) is a thrombin receptor on endothelial cells that is involved in promoting activation of the anticoagulant protein C pathway during blood coagulation. TM also exerts protective anti-inflammatory properties through a poorly understood mechanism. In this study, we investigated the importance of TM signaling to cellular functions by deleting it from endothelial cells by CRISPR-Cas9 technology and analyzed the resultant phenotype of TM-deficient (
) cells. Deficiency of TM in endothelial cells resulted in increased basal permeability and hyperpermeability when stimulated by thrombin and TNF-α. The loss of the basal barrier permeability function was accompanied by increased tyrosine phosphorylation of VE-cadherin and reduced polymerization of F-actin filaments at cellular junctions. A significant increase in basal NF-κB signaling and expression of inflammatory cell adhesion molecules was observed in
cells that resulted in enhanced adhesion of leukocytes to
cells in flow chamber experiments. There was also a marked increase in expression, storage, and release of the von Willebrand factor (VWF) and decreased storage and release of angiopoietin-2 in
cells. In a flow chamber assay, isolated platelets adhered to
cells, forming characteristic VWF-platelet strings. Increased VWF levels and inflammatory foci were also observed in the lungs of tamoxifen-treated ERcre-TM
mice. Reexpression of the TM construct in
cells, but not treatment with soluble TM, normalized the cellular phenotype. Based on these results, we postulate cell-bound TM endows a quiescent cellular phenotype by tightly regulating expression of procoagulant, proinflammatory, and angiogenic molecules in vascular endothelial cells. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 1091-6490 1091-6490 |
| DOI: | 10.1073/pnas.2022248118 |