Serum amyloid A receptor blockade and incorporation into high-density lipoprotein modulates its pro-inflammatory and pro-thrombotic activities on vascular endothelial cells

Belal Chami; Nicola Barrie; Xiaoping Cai; Xiaosuo Wang; Moumita Paul; Rebecca Morton-Chandra; Alexandra Sharland; Joanne M Dennis; Saul B Freedman; Paul K Witting

doi:10.3390/ijms160511101

Serum amyloid A receptor blockade and incorporation into high-density lipoprotein modulates its pro-inflammatory and pro-thrombotic activities on vascular endothelial cells

Int J Mol Sci. 2015 May 15;16(5):11101-24. doi: 10.3390/ijms160511101.

Authors

Affiliations

¹ Discipline of Pathology, Sydney Medical School, the University of Sydney, Sydney, NSW 2006, Australia. belal.chami@sydney.edu.au.
² Discipline of Pathology, Sydney Medical School, the University of Sydney, Sydney, NSW 2006, Australia. nicola.gbarrie@gmail.com.
³ Discipline of Pathology, Sydney Medical School, the University of Sydney, Sydney, NSW 2006, Australia. xcai4874@uni.sydney.edu.au.
⁴ Discipline of Pathology, Sydney Medical School, the University of Sydney, Sydney, NSW 2006, Australia. xiaosuo.wang@sydney.edu.au.
⁵ Transplantation Immunobiology Group, Central Clinical School, Sydney Medical School, the University of Sydney, Sydney, NSW 2006, Australia. moumita.paul@sydney.edu.au.
⁶ Transplantation Immunobiology Group, Central Clinical School, Sydney Medical School, the University of Sydney, Sydney, NSW 2006, Australia.
⁷ Transplantation Immunobiology Group, Central Clinical School, Sydney Medical School, the University of Sydney, Sydney, NSW 2006, Australia. alexandra.sharland@sydney.edu.au.
⁸ Discipline of Pathology, Sydney Medical School, the University of Sydney, Sydney, NSW 2006, Australia. martindennis@optusnet.com.au.
⁹ Sydney Medical School, the University of Sydney, ANZAC Research Institute, Concord Repatriation General Hospital, Sydney, NSW 2139, Australia. ben.freedman@sydney.edu.au.
¹⁰ Discipline of Pathology, Sydney Medical School, the University of Sydney, Sydney, NSW 2006, Australia. paul.witting@sydney.edu.au.

Abstract

The acute phase protein serum amyloid A (SAA), a marker of inflammation, induces expression of pro-inflammatory and pro-thrombotic mediators including ICAM-1, VCAM-1, IL-6, IL-8, MCP-1 and tissue factor (TF) in both monocytes/macrophages and endothelial cells, and induces endothelial dysfunction-a precursor to atherosclerosis. In this study, we determined the effect of pharmacological inhibition of known SAA receptors on pro-inflammatory and pro-thrombotic activities of SAA in human carotid artery endothelial cells (HCtAEC). HCtAEC were pre-treated with inhibitors of formyl peptide receptor-like-1 (FPRL-1), WRW4; receptor for advanced glycation-endproducts (RAGE), (endogenous secretory RAGE; esRAGE) and toll-like receptors-2/4 (TLR2/4) (OxPapC), before stimulation by added SAA. Inhibitor activity was also compared to high-density lipoprotein (HDL), a known inhibitor of SAA-induced effects on endothelial cells. SAA significantly increased gene expression of TF, NFκB and TNF and protein levels of TF and VEGF in HCtAEC. These effects were inhibited to variable extents by WRW4, esRAGE and OxPapC either alone or in combination, suggesting involvement of endothelial cell SAA receptors in pro-atherogenic gene expression. In contrast, HDL consistently showed the greatest inhibitory action, and often abrogated SAA-mediated responses. Increasing HDL levels relative to circulating free SAA may prevent SAA-mediated endothelial dysfunction and ameliorate atherogenesis.

Keywords: atherosclerosis; high-density lipoprotein; inflammation; serum amyloid A.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Apolipoprotein A-I / metabolism
Cells, Cultured
Endothelial Cells / cytology
Endothelial Cells / drug effects
Endothelial Cells / metabolism
Enzyme-Linked Immunosorbent Assay
Gene Expression Regulation / drug effects*
Humans
Immunohistochemistry
Lipoproteins, HDL / isolation & purification
Lipoproteins, HDL / pharmacology*
NF-kappa B / genetics
NF-kappa B / metabolism
Peptides / pharmacology
Phosphatidylcholines / pharmacology
Receptor for Advanced Glycation End Products / genetics
Receptor for Advanced Glycation End Products / metabolism
Receptors, Formyl Peptide / chemistry
Receptors, Formyl Peptide / metabolism
Receptors, Lipoxin / chemistry
Receptors, Lipoxin / metabolism
Recombinant Proteins / biosynthesis
Recombinant Proteins / genetics
Recombinant Proteins / pharmacology
Serum Amyloid A Protein / antagonists & inhibitors
Serum Amyloid A Protein / metabolism*
Serum Amyloid A Protein / pharmacology
Thromboplastin / genetics
Thromboplastin / metabolism
Tumor Necrosis Factor-alpha / analysis
Tumor Necrosis Factor-alpha / genetics
Tumor Necrosis Factor-alpha / metabolism
Vascular Endothelial Growth Factor A / metabolism

Substances

Apolipoprotein A-I
FPR2 protein, human
Lipoproteins, HDL
NF-kappa B
Peptides
Phosphatidylcholines
Receptor for Advanced Glycation End Products
Receptors, Formyl Peptide
Receptors, Lipoxin
Recombinant Proteins
Serum Amyloid A Protein
Tumor Necrosis Factor-alpha
Vascular Endothelial Growth Factor A
oxidized-L-alpha-1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine
Thromboplastin