Expression of CARD8 in human atherosclerosis and its regulation of inflammatory proteins in human endothelial cells

Geena V Paramel,Peder S Olofsson,Ulf Hedin,Anna Göthlin Eremo,Lasse Folkersen,Allan Sirsjö,Karin Fransén,Gabrielle Paulsson-Berne,Glykeria Karadimou,Liza U Ljungberg

doi:10.1038/s41598-020-73600-4

Abstract

The Caspase activation and recruitment domain 8 (CARD8) protein is a component of innate immunity and overexpression of CARD8 mRNA was previously identified in atherosclerosis. However, very little is known about the regulation of CARD8 in endothelial cells and atherosclerosis. The aim of this study was to investigate CARD8 in the regulation of cytokine and chemokine expression in endothelial cells. Sections of human atherosclerotic lesions and non-atherosclerotic arteries were immunostained for CARD8 protein. Expression of CARD8 was correlated to mediators of inflammation in atherosclerotic lesions using Biobank of Karolinska Endarterectomies microarray data. The CARD8 mRNA was knocked-down in human umbilical vein endothelial cells (HUVECs) in vitro, followed by quantitative RT-PCR analysis and OLINK Proteomics. Endothelial and smooth muscle cells in arterial tissue expressed CARD8 and CARD8 correlated with vWF, CD163 and the expression of inflammatory genes, such as CXCL1, CXCL6 and PDGF-A in plaque. Knock-down of CARD8 in HUVECs significantly altered proteins involved in inflammatory response, such as CXCL1, CXCL6, PDGF-A, MCP-1 and IL-6. The present study suggest that CARD8 regulate the expression of cytokines and chemokines in endothelial cells and atherosclerotic lesions, suggesting that CARD8 plays a significant role in endothelial activation.

Highlights

The Caspase activation and recruitment domain 8 (CARD8) protein is a component of innate immunity and overexpression of CARD8 mRNA was previously identified in atherosclerosis
CARD8 was detected in the endothelial layer, smooth muscle cells and CD68 positive macrophages (Fig. 2), suggesting that the immune cells together with vascular cells contribute to the increased expression of CARD8 in the human atherosclerotic lesion
We show that CARD8 protein is expressed in endothelial cells and SMCs of healthy and atherosclerotic vessels and that CARD8 may be an upstream regulator of several inflammatory cytokines and chemokines in both endothelial cells and human carotid plaques

Summary

Introduction

The Caspase activation and recruitment domain 8 (CARD8) protein is a component of innate immunity and overexpression of CARD8 mRNA was previously identified in atherosclerosis. The aim of this study was to investigate CARD8 in the regulation of cytokine and chemokine expression in endothelial cells. The present study suggest that CARD8 regulate the expression of cytokines and chemokines in endothelial cells and atherosclerotic lesions, suggesting that CARD8 plays a significant role in endothelial activation. The CARD8 has in earlier studies been associated with a possible role in the NLRP3 inflammasome complex and has been found over-expressed in atherosclerotic lesions[10]. The aim of the present study is to examine the expression of CARD8 in human atherosclerotic lesion and to elucidate the role of CARD8 in the regulation of inflammatory proteins in endothelial cells and atherosclerotic lesions

Objectives

Methods

Results

Conclusion