gms | German Medical Science

Introduction: The C-type natriuretic peptide (CNP) has anti-inflammatory, anti-proliferative, and anti-migratory properties, which may be relevant during development of atherosclerosis. No data exist on the presence of CNP and its receptors in human arteriosclerotic plaques of the carotid artery. Therefore, we investigated the distribution pattern and characteristics of CNP and its receptors in both, early and advanced human carotid plaques as well as in stable and unstable plaques. In addition, this study should validate CNP and its receptors as possible biomarkers to predict plaque stability.

Materials and methods: Advanced carotid artery plaques of 40 patients (20 stable and 20 unstable plaques, Virmani classification) and early arteriosclerotic lesions of 3 patients were analyzed using immunohistochemistry and quantitative gene expression analysis of CNP and its receptors and correlated with clinical data.

Results: Expression level of natriuretic peptide receptor 3 (NPR3) was significantly higher in unstable plaques compared to stable plaques (5.6±1.8% vs. 1.7±0.5%, p=0.039, ANOVA). Expression levels of CNP and NPR2 were higher in unstable plaques but the differences were not statistically significant. The distribution pattern of CNP, NPR2 and NPR3 varied between early and advanced carotid plaques but no differences were observed with respect to plaque stability.

Conclusion: This study shows for the first time the presence of CNP and its receptors in atherosclerotic plaques of the human carotid artery. Furthermore, our results indicate the modulation of CNP and its receptors in accordance with the degree of the lesion and plaque vulnerability. This suggests that CNP and its receptors may be involved in regulation of plaque formation in humans and might be a possible factor to estimate the risk of plaque rupture in the future.