Toll-like receptor 2, hyaluronan, and neutrophils play a key role in plaque erosion: the OPTICO-ACS study
- PMID: 37381760
- DOI: 10.1093/eurheartj/ehad379
Toll-like receptor 2, hyaluronan, and neutrophils play a key role in plaque erosion: the OPTICO-ACS study
Abstract
Background and aims: In one-third of patients with acute coronary syndrome (ACS), thrombosis occurs despite an intact fibrous cap (IFC) (IFC-ACS, 'plaque erosion'). Recent studies emphasize neutrophils as the immediate inflammatory response in this pathology, but their exact molecular activation patterns are still poorly understood and may represent future therapeutic targets.
Methods and results: Thirty-two patients with IFC-ACS and matched patients with ACS with ruptured fibrous cap (RFC) (RFC-ACS) from the OPTICO-ACS study were included, and blood samples were collected from the local site of the culprit lesion and the systemic circulation. Neutrophil surface marker expression was quantified by flow cytometry. Neutrophil cytotoxicity towards endothelial cells was examined in an ex vivo co-culture assay. Secretion of active matrix metalloproteinase 9 (MMP9) by neutrophils was evaluated using zymography in supernatants and in plasma samples. Optical coherence tomography (OCT)-embedded thrombi were used for immunofluorescence analysis. Toll-like receptor 2 (TLR2) expression was higher on neutrophils from IFC-ACS than RFC-ACS patients. TLR2 stimulation increased the release of active MMP9 from local IFC-ACS-derived neutrophils, which also aggravated endothelial cell death independently of TLR2. Thrombi of IFC-ACS patients exhibited more hyaluronidase 2 with concomitant increase in local plasma levels of the TLR2 ligand: hyaluronic acid.
Conclusion: The current study provides first in-human evidence for distinct TLR2-mediated neutrophil activation in IFC-ACS, presumably triggered by elevated soluble hyaluronic acid. Together with disturbed flow conditions, neutrophil-released MMP9 might be promoting endothelial cell loss-triggered thrombosis and therefore providing a potential future target for a phenotype-specific secondary therapeutic approach in IFC-ACS.
Keywords: Endothelial cell death; Hyaluronic acid; Matrix metalloproteinase 9; Neutrophils; Plaque erosion; Toll-like receptor 2.
© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Comment in
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Unravelling ACS pathophysiology using intracoronary OCT and deep immunophenotyping.Nat Rev Cardiol. 2023 Sep;20(9):581. doi: 10.1038/s41569-023-00915-w. Nat Rev Cardiol. 2023. PMID: 37491589 No abstract available.
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Unravelling the heart's comic drama: can TLRs and hyaluronan metabolism stoke neutrophil rage in acute coronary syndrome?Eur Heart J. 2023 Oct 12;44(38):3908-3910. doi: 10.1093/eurheartj/ehad455. Eur Heart J. 2023. PMID: 37674369 No abstract available.
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