Thromb Haemost 2013; 110(01): 141-152
DOI: 10.1160/TH13-02-0155
Cardiovascular Biology and Cell Signalling
Schattauer GmbH

Endothelial CSN5 impairs NF-κB activation and monocyte adhesion to endothelial cells and is highly expressed in human atherosclerotic lesions

Yaw Asare
1  Institute of Biochemistry and Molecular Cell Biology, RWTH Aachen University, Aachen, Germany
,
Erdenechimeg Shagdarsuren
2  Institute of Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
,
Johannes A. Schmid
3  Center for Physiology and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University Vienna, Vienna, Austria
,
Pathricia V. Tilstam
2  Institute of Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
,
Jochen Grommes
2  Institute of Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
4  European Vascular Center Aachen-Maastricht, Department of Vascular Surgery, RWTH Aachen University, Aachen, Germany
,
Omar El Bounkari
1  Institute of Biochemistry and Molecular Cell Biology, RWTH Aachen University, Aachen, Germany
,
Anke K. Schütz
1  Institute of Biochemistry and Molecular Cell Biology, RWTH Aachen University, Aachen, Germany
,
Christian Weber
5  Institute for Cardiovascular Prevention, Ludwig-Maximilians-University Munich, Munich, Germany
6  Munich Heart Alliance, Munich, Germany
7  Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, The Netherlands
,
Menno P. J. de Winther*
7  Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, The Netherlands
,
Heidi Noels§
2  Institute of Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
,
Jürgen Bernhagen§
1  Institute of Biochemistry and Molecular Cell Biology, RWTH Aachen University, Aachen, Germany
8  August-Lenz-Stiftung, Institute for Cardiovascular Research, Ludwig-Maximilians-University Munich, Munich, Germany
› Author Affiliations
Financial support: This work was supported by the Deutsche Forschungsgemeinschaft (DFG) International graduate school grant IRTG1508/1-TP6 to J.B. and Y.A., by the Alexander von Humboldt Foundation to H.N., and by the Netherlands Organization for Health Research and Development to M.W. M.W. is an established investigator of the Netherlands Heart Foundation.
Further Information

Publication History

Received: 20 February 2013

Accepted after minor revision: 05 April 2013

Publication Date:
30 November 2017 (online)

Summary

The COP9 signalosome (CSN), a multifunctional protein complex involved in the regulation of cullin-RING-E3 ubiquitin ligases (CRLs), has emerged as a regulator of NF-κB signalling. As NF-κB drives the expression of pro-inflammatory and pro-atherosclerotic genes, we probed the yet unknown role of the CSN, in particular CSN5, on NF-KB-mediated atherogenic responses in endothelial cells. Co-immunoprecipitation in human umbilical vein endothelial cells (HUVECs) revealed the presence of a super-complex between IKK and CSN, which dissociates upon TNF-α stimulation. Furthermore, CSN5 silencing enhanced TNF-α-induced IKB-α degradation and NF-κB activity in luci-ferase reporter assays. This was paralleled by an increased NF-KB-driven upregulation of atherogenic chemokines and adhesion molecules, as measured by qPCR and flow cytometry, and translated into an enhanced arrest of THP-1 monocytes on TNF-α-stimulated, CSN5-depleted HUVECs. Reverse effects on NF-κB activity and THP-1 arrest were seen upon CSN5 overexpression. Finally, double-immunostaining confirmed the expression of CSN subunits in the endothelium of human atherosclerotic lesions, and revealed an increased expression of CSN5 which correlated with atheroprogression. In conclusion, endothelial CSN5 attenuates NF-KB-dependent pro-inflammatory gene expression and monocyte arrest on stimulated endothelial cells in vitro, suggesting that CSN5 might serve as a negative regulator of atherogenesis.

Note: The review process for this manuscript was fully handled by G. Y. H. Lip, Editor in Chief.

§ These authors share senior-authorship and contributed equally to this work.


* Current address: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.