MicroRNA (miR) is reported to be involved in vascular inflammation and may represent a novel class of diagnostic biomarkers in cardiovascular disease. We aimed to identify the miR expression profile in human advanced coronary atherosclerotic plaques (CAP) and to connect this expression to the processes in atherosclerosis. Microarray techniques and TaqMan polymerase chain reaction were used to analyse the global expression of 352 miRs in CAP obtained during ACS MULTI-LINK study. 11 miRs were selected on the basis of their implication in atherosclerosis, endothelial activation, and inflammation. 6 miRs were found to be differently expressed in CAP when compared to non-atherosclerotic internal mammary arteries (IMA, p < 0.05). The expression of miR-21, -92a, and -99a was verified and found to be significantly up-regulated in CAP versus IMA (p < 0.001). We also performed bioinformatic analysis and found several potential target genes of miR-92a and -99a as well as several pathways with impact on atherosclerosis which could be differently expressed due to this miRNA profile. The most up-regulated miRs are involved in processes known to be connected to atherosclerosis. Interfering with the miR expression in the artery wall is a potential way to affect atherosclerotic plaque and cardiovascular disease development.

Factor VII activating protease (FSAP) is a circulating serine protease strongly expressed in unstable plaques and may serve as a marker of plaque destabilization. The aim of this study was to examine the relation between plasma concentrations of FSAP and clinical instability and outcome in coronary artery disease (CAD). Circulating FSAP concentration and activity, as well as FSAP mRNA expression in monocytes, were measured in 231 sequential patients who underwent coronary angiography because of stable angina pectoris (n=50), unstable angina pectoris (n=43), or acute myocardial infarction (n=87). FSAP activity, but not FSAP antigen concentration, was elevated in patients with CAD compared with a control group. Elevated FSAP activity (≥1.035 plasma equivalent units [PEU]/ml) indicated a significantly increased risk of death or non-fatal myocardial infarction during 1 year of follow-up as compared with patients with low activity of FSAP (odds ratio 1.895 [95% confidence interval 1.093-3.283]; P=0.023). Furthermore, there were no significant changes in the FSAP expression in monocytes from CAD and control subjects in the basal state but there were differences after stimulation with proinflammatory factors. Plasma FSAP activity was significantly increased in patients with acute coronary syndrome and may be involved in the pathogenesis of these conditions. High levels of FSAP activity were predictive of adverse events during follow-up, suggesting its potential role in risk stratification and clinical management of CAD patients.

MicroRNA has been increasingly suggested to be involved in vascular inflammation. The aim of this study was to assess the expression profile of miRs as possible novel cellular biomarkers in circulating monocytes in patients with ST-segment elevation myocardial infarction (STEMI). Microarray techniques and TaqMan polymerase chain reaction were used to analyse the global expression of 352 miRNAs in peripheral blood monocytes from healthy donors (n = 20) and patients (n = 24) with acute STEMI. The expression level of miR-143 in monocytes from STEMI patients compared to healthy controls was increased, whereas the expression of miR-1, -92a, -99a, and -223 was reduced significantly. During 3.5 ± 1.5 months of follow-up miR-1 and -223 were back to baseline, whereas miR-92a and -99a return to normal levels over 3 months, but remained lower than healthy controls. Furthermore, monocytic expression of miR-143 was positively correlated with hs-CRP (R² = 0.338; P < 0.031), but not with cTnT. Importantly, treatment of monocytes isolated from healthy individuals with INFγ, but not LPS or TNFα caused an upregulation of miR-143 and downregulation of miR-1. Our findings identify circulating monocytes as putative biomarkers and as novel carriers for the cell-specific transfer of miRs in the early phase of myocardial infarction.

Background: Cardiac-specific JDP2 overexpression provokes ventricular dysfunction and atrial dilatation in mice. We performed in vivo studies on JDP2-overexpressing mice to investigate the impact of JDP2 on the predisposition to spontaneous atrial fibrillation (AF). Methods: JDP2-overexpression was started by withdrawal of a doxycycline diet in 4-week-old mice. The spontaneous onset of AF was documented by ECG within 4 to 5 weeks of JDP2 overexpression. Gene expression was analyzed by real-time RT-PCR and Western blots. Results: In atrial tissue of JDP2 mice, besides the 3.6-fold increase of JDP2 mRNA, no changes could be detected within one week of JDP2 overexpression. Atrial dilatation and hypertrophy, combined with elongated cardiomyocytes and fibrosis, became evident after 5 weeks of JDP2 overexpression. Electrocardiogram (ECG) recordings revealed prolonged PQ-intervals and broadened P-waves and QRS-complexes, as well as AV-blocks and paroxysmal AF. Furthermore, reductions were found in the atrial mRNA and protein level of the calcium-handling proteins NCX, Cav1.2 and RyR2, as well as of connexin40 mRNA. mRNA of the hypertrophic marker gene ANP, pro-inflammatory MCP1, as well as markers of immune cell infiltration (CD68, CD20) were increased in JDP2 mice. Conclusion: JDP2 is an important regulator of atrial calcium and immune homeostasis and is involved in the development of atrial conduction defects and arrhythmogenic substrates preceding paroxysmal AF.