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Updated: Jul 4, 2025
Glycoproteomics of the Extracellular Matrix: A Method for Intact Glycopeptide Analysis Using Mass Spectrometry
Published on: April 21, 2017
Proteomic analysis of the extracellular matrix of human atherosclerotic plaques shows marked changes between plaque
Lasse G Lorentzen1, Karin Yeung2,3, Nikolaj Eldrup2,3
1Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Denmark.
Insights
Atherosclerosis plaque composition differs between stable and unstable types. Unstable plaques show more inflammation and ECM remodeling proteins, while stable plaques have more structural ECM proteins, aiding risk stratification.
Area of Science:
- Biochemistry
- Proteomics
- Cardiovascular Research
Background:
- Cardiovascular disease, primarily atherosclerosis, is a leading global cause of mortality.
- Atherosclerotic plaque rupture leads to acute events like myocardial infarction and stroke.
- Extracellular matrix (ECM) remodeling is strongly linked to plaque instability.
Purpose of the Study:
- To investigate differences in ECM composition between stable and unstable atherosclerotic plaques.
- To correlate proteomic profiles with clinical and morphological plaque characteristics.
- To identify potential biomarkers for atherosclerosis risk stratification.
Main Methods:
- Analysis of atherosclerotic plaques from 21 patients undergoing carotid surgery.
- A novel single-step solubilization and liquid chromatography-mass spectrometry approach.
- Identification and quantification of 4498 plaque proteins, including 354 ECM proteins.
Main Results:
- Two distinct plaque clusters identified, correlating with morphology, ultrasound, and ulceration.
- 714 differentially abundant proteins found between plaque types.
- Soft/unstable plaques enriched in inflammation and ECM remodeling proteins (e.g., MMPs, cathepsins).
- Hard/stable plaques showed higher levels of structural ECM proteins (e.g., collagens, versican).
Conclusions:
- Proteomics can reveal mechanistic insights into plaque ECM remodeling and inflammation.
- Plaque proteomic profiles correlate with clinical parameters and stability.
- This approach aids in understanding plaque destabilization and identifying biomarkers for risk profiling.
Abstract:
Cardiovascular disease is the leading cause of death, with atherosclerosis the major underlying cause. While often asymptomatic for decades, atherosclerotic plaque destabilization and rupture can arise suddenly and cause acute arterial occlusion or peripheral embolization resulting in myocardial infarction, stroke and lower limb ischaemia. As extracellular matrix (ECM) remodelling is associated with plaque instability, we hypothesized that the ECM composition would differ between plaques. We analyzed atherosclerotic plaques obtained from 21 patients who underwent carotid surgery following recent symptomatic carotid artery stenosis. Plaques were solubilized using a new efficient, single-step approach. Solubilized proteins were digested to peptides, and analyzed by liquid chromatography-mass spectrometry using data-independent acquisition. Identification and quantification of 4498 plaque proteins was achieved, including 354 ECM proteins, with unprecedented coverage and high reproducibility. Multidimensional scaling analysis and hierarchical clustering indicate two distinct clusters, which correlate with macroscopic plaque morphology (soft/unstable versus hard/stable), ultrasound classification (echolucent versus echogenic) and the presence of hemorrhage/ulceration. We identified 714 proteins with differential abundances between these groups. Soft/unstable plaques were enriched in proteins involved in inflammation, ECM remodelling, and protein degradation (e.g. matrix metalloproteinases, cathepsins). In contrast, hard/stable plaques contained higher levels of ECM structural proteins (e.g. collagens, versican, nidogens, biglycan, lumican, proteoglycan 4, mineralization proteins). These data indicate that a single-step proteomics method can provide unique mechanistic insights into ECM remodelling and inflammatory mechanisms within plaques that correlate with clinical parameters, and help rationalize plaque destabilization. These data also provide an approach towards identifying biomarkers for individualized risk profiling of atherosclerosis.
