Comparative analysis of whole plasma, high density lipoprotein and microvesicles carried miRNAs in a group of patients with coronary atherosclerotic disease

Background Atherosclerosis is the leading cause of cardiovascular mortality worldwide. MicroRNAs (miRNAs) regulate key mechanisms involved in atherosclerotic plaque development, including lipid handling, endothelial dysfunction, inflammation, and vascular remodeling. In blood, miRNAs can be detected in different biological compartments, including whole plasma (WP), high-density lipoproteins (HDL), and Microvesicles (MVs). Purpose The aim of this study was to explore the role of circulating miRNA carried by different matrixes, including WP, HDL, or MVs, in patients with suspected coronary atherosclerotic disease (CAD), as assessed by computed tomography angiography (CTA). Methods Circulating miRNA profile was compared across WP, HDL, or MVs obtained by 27 subjects enrolled in the HURRICANE retrospective study. All subjects were characterized by a complete clinical and molecular profile. MVs were isolated from EDTA plasma using a dextran/polyethylene glycol precipitation method, and HDL by sequential ultracentrifugation. Total RNA was extracted from WP, MVs, and HDL fractions and miRNAs were analyzed by real-time PCR. All patients underwent coronary CTA to assess total, calcified, and noncalcified plaque volume (PV). Obstructive CAD was defined as the presence of stenoses >50% in at least one of the main coronary vessels. Results Among the miRNAs tested (n=25), miR-126-5p, miR-145-5p, miR-30e-5p, miR-375-3p, miR-638, and miR-92a-3p were consistently detected in WP, HDL, and MVs. Overall, miRNA levels were higher in WP compared with particle-associated fractions, except for miR-638, which was enriched in MVs (Fig 1 A-F). Obstructive CAD was diagnosed in 21 subjects (78%) and clinical, molecular and CTA differences between CAD and no CAD were reported in Fig 1G. Significant differences between CAD and no CAD patients were observed exclusively in MV-miRNAs (Fig 2A-F). Specifically, miR-126-5p and miR-145-5p were reduced in CAD patients, whereas miR-30e-5p, miR-638, and miR-92a-3p increased compared with no CAD. In CAD patients, only MV- miR-126-5p, miR-375-3p, and miR-30e-5p showed significant correlations with cardiometabolic risk factors, including BMI, triglycerides, remnant cholesterol, and HDL cholesterol (Fig 2G). Only MV- miR-126-5p, miR-145-5p, miR-375-3p, and miR-30e-5p were significantly associated with total, calcified, and noncalcified PVs (Fig 2G). Conclusions These findings collectively identified MVs as the most informative circulating matrix for miRNA assessment in CAD. Unlike WP and HDL, MV- miRNAs discriminated CAD from no CAD patients and correlated with cardiometabolic risk and coronary plaque burden, suggesting a potential involvement of MV-associated miRNAs in molecular mechanisms of atherosclerosis reflecting plaque biology.Figure 1Figure 2