Extracellular matrix proteomics identifies molecular signature of symptomatic carotid plaques

J Clin Invest. 2017 Apr 3;127(4):1546-1560. doi: 10.1172/JCI86924. Epub 2017 Mar 20.

Abstract

Background: The identification of patients with high-risk atherosclerotic plaques prior to the manifestation of clinical events remains challenging. Recent findings question histology- and imaging-based definitions of the "vulnerable plaque," necessitating an improved approach for predicting onset of symptoms.

Methods: We performed a proteomics comparison of the vascular extracellular matrix and associated molecules in human carotid endarterectomy specimens from 6 symptomatic versus 6 asymptomatic patients to identify a protein signature for high-risk atherosclerotic plaques. Proteomics data were integrated with gene expression profiling of 121 carotid endarterectomies and an analysis of protein secretion by lipid-loaded human vascular smooth muscle cells. Finally, epidemiological validation of candidate biomarkers was performed in two community-based studies.

Results: Proteomics and at least one of the other two approaches identified a molecular signature of plaques from symptomatic patients that comprised matrix metalloproteinase 9, chitinase 3-like-1, S100 calcium binding protein A8 (S100A8), S100A9, cathepsin B, fibronectin, and galectin-3-binding protein. Biomarker candidates measured in 685 subjects in the Bruneck study were associated with progression to advanced atherosclerosis and incidence of cardiovascular disease over a 10-year follow-up period. A 4-biomarker signature (matrix metalloproteinase 9, S100A8/S100A9, cathepsin D, and galectin-3-binding protein) improved risk prediction and was successfully replicated in an independent cohort, the SAPHIR study.

Conclusion: The identified 4-biomarker signature may improve risk prediction and diagnostics for the management of cardiovascular disease. Further, our study highlights the strength of tissue-based proteomics for biomarker discovery.

Funding: UK: British Heart Foundation (BHF); King's BHF Center; and the National Institute for Health Research Biomedical Research Center based at Guy's and St Thomas' NHS Foundation Trust and King's College London in partnership with King's College Hospital. Austria: Federal Ministry for Transport, Innovation and Technology (BMVIT); Federal Ministry of Science, Research and Economy (BMWFW); Wirtschaftsagentur Wien; and Standortagentur Tirol.

MeSH terms

  • Atherosclerosis / metabolism
  • Biomarkers / metabolism
  • Carotid Artery Diseases / metabolism
  • Carotid Artery Diseases / surgery
  • Cells, Cultured
  • Endarterectomy, Carotid
  • Extracellular Matrix / metabolism*
  • Extracellular Matrix Proteins / metabolism*
  • Female
  • Humans
  • Male
  • Myocytes, Smooth Muscle / metabolism
  • Plaque, Atherosclerotic / metabolism*
  • Proteome / metabolism*
  • Proteomics

Substances

  • Biomarkers
  • Extracellular Matrix Proteins
  • Proteome