Endothelial Cell Activation by Interleukin-1 and Extracellular Matrix Laminin-10 Occurs via the Yap Signalling Pathway

Mapping Intimacies ◽

10.21203/rs.3.rs-365829/v1 ◽

2021 ◽

Author(s):

Hannah Thurgur ◽

Jeffrey Penny ◽

Emmanuel Pinteaux

Keyword(s):

Extracellular Matrix ◽

Endothelial Cell ◽

Cell Activation ◽

Interleukin 1 ◽

Tube Formation ◽

Signalling Pathway ◽

Endothelial Cell Activation ◽

First Time

Abstract Background: The extracellular matrix (ECM) plays an important role for normal brain functions and homeostasis, and contributes to the inflammatory response and mechanisms of brain repair after acute brain injury. We have previously reported that the ECM laminin-10 (LM-10) is a key regulator of blood-brain barrier (BBB) integrity, and is involved in BBB repair after hypoxic injury and interleukin-1 (IL-1)-induced inflammation in vitro. To further investigate the role of LM-10 in BBB inflammation and repair, we investigated for the first time the signalling mechanisms regulated by LM-10 in brain endothelial cells in response to IL-1β-induced inflammation in vitro. Methods: Human brain endothelial cell line hCMEC/D3 cultured on Matrigel- or LM-10-coated tissue culture plates were left untreated or were treated with human recombinant IL-1β at various concentrations and/or for various periods of time. In vitro hallmarks of angiogenesis were assessed using a scratch injury model and tube formation assay. Expression of cell adhesion molecules ICAM-1 and VCAM-1, as well as IL-8 was measured using ELISA. Activation of signalling pathways ERK1/2, p38, NF-κB and YAP was assessed by quantitative ELISA or Western blot. Activation of genes downstream of YAP signalling was assessed by quantitative polymerase chain reaction.Results: LM-10 promoted endothelial proliferation and subsequent repair of an endothelial monolayer after scratch injury, induced tube formation, and upregulated IL-1β-induced ICAM-1 and VCAM-1 expression in vitro. Classical IL-1β-induced signalling pathway ERK1/2 and p38 were not modulated by LM-10, whilst LM-10 upregulated IL-1β-induced NF-κB activation. Importantly, we demonstrate for the first time a role of the YAP signalling pathway in endothelial cell activation, in that LM-10 significantly downregulates p-YAP (S397) activation without affecting phosphorylation of YAP (S127), leading to differential expression of YAP target genes, ctgf and serpine-1 involved in endothelial cell activation. Conclusion: Our study provides for the first time evidence that the YAP signalling pathway is an important regulator of endothelial cell activation, and could be a new therapeutic target for the treatment of cerebrovascular inflammatory diseases.

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Dengue Virus Induces the Expression and Release of Endocan from Endothelial Cells by an NS1–TLR4-Dependent Mechanism

Microorganisms ◽

10.3390/microorganisms9061305 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1305

Author(s):

Carlos Alonso Domínguez-Alemán ◽

Luis Alberto Sánchez-Vargas ◽

Karina Guadalupe Hernández-Flores ◽

Andrea Isabel Torres-Zugaide ◽

Arturo Reyes-Sandoval ◽

...

Keyword(s):

Endothelial Cell ◽

Mrna Expression ◽

Cell Lines ◽

Cell Activation ◽

Dengue Infection ◽

Elevated Serum ◽

Fold Increase ◽

Endothelial Cell Activation ◽

Stimulation Of

A common hallmark of dengue infections is the dysfunction of the vascular endothelium induced by different biological mechanisms. In this paper, we studied the role of recombinant NS1 proteins representing the four dengue serotypes, and their role in promoting the expression and release of endocan, which is a highly specific biomarker of endothelial cell activation. We evaluated mRNA expression and the levels of endocan protein in vitro following the stimulation of HUVEC and HMEC-1 cell lines with recombinant NS1 proteins. NS1 proteins increase endocan mRNA expression 48 h post-activation in both endothelial cell lines. Endocan mRNA expression levels were higher in HUVEC and HMEC-1 cells stimulated with NS1 proteins than in non-stimulated cells (p < 0.05). A two-fold to three-fold increase in endocan protein release was observed after the stimulation of HUVECs or HMEC-1 cells with NS1 proteins compared with that in non-stimulated cells (p < 0.05). The blockade of Toll-like receptor 4 (TLR-4) signaling on HMEC-1 cells with an antagonistic antibody prevented NS1-dependent endocan production. Dengue-infected patients showed elevated serum endocan levels (≥30 ng/mL) during early dengue infection. High endocan serum levels were associated with laboratory abnormalities, such as lymphopenia and thrombocytopenia, and are associated with the presence of NS1 in the serum.

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Role of CL-100, a Dual Specificity Phosphatase, in Thrombin-induced Endothelial Cell Activation

Journal of Biological Chemistry ◽

10.1074/jbc.m406441200 ◽

2004 ◽

Vol 279 (45) ◽

pp. 46678-46685 ◽

Cited By ~ 28

Author(s):

Unni M. Chandrasekharan ◽

Lin Yang ◽

Alicia Walters ◽

Philip Howe ◽

Paul E. DiCorleto

Keyword(s):

Endothelial Cell ◽

Cell Activation ◽

Endothelial Cell Activation ◽

Dual Specificity Phosphatase ◽

Dual Specificity

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160. THE ROLE OF PHAGOCYTOSIS OF APOPTOTIC SYNCYTIAL KNOTS IN THE PREVENTION OF ENDOTHELIAL CELL ACTIVATION: AN IMPORTANT ADAPTATION FOR NORMAL PREGNANCY

Reproduction Fertility and Development ◽

10.1071/srb10abs160 ◽

2010 ◽

Vol 22 (9) ◽

pp. 78

Author(s):

Q. Chen ◽

H. Jin ◽

P. Stone ◽

L. Chamley

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Immune Responses ◽

Cell Activation ◽

Normal Pregnancy ◽

Cytochalasin D ◽

Endothelial Cell Activation ◽

Endothelial Cell Surface ◽

Large Numbers

Preeclampsia is characterised by an exaggerated inflammatory response and maternal endothelial cell activation. Syncytial knots, dead multinucleated fetal cells shed from the placenta in large numbers during all pregnancies, may be phagocytosed by maternal endothelial cells. Our previous studies showed that phagocytosis of necrotic but not apoptotic syncytial knots led to endothelial cell activation. It is known that phagocytosis of apoptotic cells leads to active tolerance of immune responses and in this study we questioned whether phagocytosis of apoptotic syncytial knots leads to suppression of the endothelial cells ability to be activated. Syncytial knots were harvested from 1st trimester placental explants. Monolayers of endothelial cells were pre-treated with apoptotic syncytial knots for 24 h. After washing, the endothelial cells were treated with the endothelial cell activators LPS, PMA, IL-6, or necrotic syncytial knots for 24 h. In some experiments the inhibitor of phagocytosis, cytochalasin D, was added into the cultures along with apoptotic syncytial knots. Endothelial cell-surface ICAM-1 was measured using cell based ELISAs. Expression of ICAM-1 by endothelial cells that had phagocytosed apoptotic syncytial knots prior to treatment with LPS, PMA, IL-6, or necrotic syncytial knots was significantly (P =/<0.003) reduced, compared to control endothelial cells that had not phagocytosed apoptotic syncytial knots. Inhibiting phagocytosis of apoptotic syncytial knots with cytochalasin D abolished this protective effect. Our data suggest phagocytosis of apoptotic syncytial knots results in the suppression of the ability of endothelial cells to be activated by a number of potent chemical activators, as well as by the physiologically relevant activator, necrotic syncytial knots. This work suggests that the release of apoptotic syncytial knots from the placenta during normal pregnancy may be a mechanism by which the fetus attempts to protect the maternal vasculature against activation.

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