The Correlation between Increased Expressions of NLRP3 Inflammasome Components in Peripheral Blood Mono-Nuclear Cells and Plaque Vulnerability in Human Carotid Atherosclerosis

BACKGROUND: We aimed to determine whether NLRP3 inflammasomes in peripheral blood mononuclear cells (PBMC) were associated with carotid plaque instability in carotid atherosclerosis patients. METHODS: Consecutive 38 carotid atherosclerosis with vulnerable plaques, 22 carotid atherosclerosis with stable plaques, and 40 healthy subjects with no carotid or coronary artery stenosis were enrolled. They were referred to the Second Hospital of Dalian Medical University from 2013–2019. Carotid plaques were evaluated by modified plaque vulnerability risk score (MPVRS) and pathological assessment. The mRNA and protein expression of NLRP3 inflammasome components in PBMC were determined by quantitative real time PCR and Western blot analysis or ELISA. RESULTS: When consecutive study subjects undergoing carotid endarterectomy were divided into stable (≤4) and unstable (>4) plaque groups according to the MPVRS, the unstable plaque group had significantly raised mRNA and protein expression of NLRP3 inflammasome components in PBMC as compared with the stable plaque group and healthy subject group. Furthermore, subjects with higher NLRP3 protein expression in PBMC had greater incidence of cerebrovascular events. CONCLUSION: Increased NLRP3 inflammasome components in PBMC is associated with instability of human carotid atherosclerotic plaques, suggesting NLRP3 inflammasome as a potential biomarker for monitoring carotid plaque instability.