Differential Expression of MicroRNAs in Endarterectomy Specimens Taken from Patients with Asymptomatic and Symptomatic Carotid Plaques.

OBJECTIVE:Stroke and transient ischemic attacks are considered as clinical manifestations of atherosclerotic disease due to on-going vascular inflammation and finally atherothrombosis of the carotid arteries. MicroRNAs (miRNA/miR) are known to be involved in vascular inflammation and plaque destabilization. The aim of this study was to analyze the expression profile of selected miRNAs in endarterectomy specimen from carotid arteries that were taken from patients with asymptomatic and symptomatic atherosclerotic plaques. METHODS AND RESULTS:11 miRNAs were selected and their expression was analyzed using real-time RT-PCR. Therefore, samples were divided into three different groups. On the one hand we investigated the expression patterns from patients in asymptomatic (n = 14) and symptomatic (n = 10) plaques; on the other hand we took samples from normal configurated internal mammary arteries (n = 15). Out of these 11 targets we identified some miRNAs, which were up- or down-regulated in either one of the two groups. Interestingly, the expression of two miRNAs was significantly different between asymptomatic and symptomatic samples, namely miR-21 (P<0.01) and miR-143 (P<0.05). CONCLUSION:In the present study, we identified miRNA subtypes which showed different expression in endarterectomy specimen from patients with asymptomatic and symptomatic plaques, suggesting that these miRNAs correlated with advanced vascular inflammation and plaque stability. They may represent new therapeutic targets for vascular proliferative diseases such as atherosclerosis

Characteristics of the patients.

<p>Characteristics of the patients.</p

Real-time RT-PCR-analysis of miRNAs from carotid endarterectomy specimen from patients with asymptomatic and symptomatic plaques and from unaffected specimen from the internal mammary artery of healthy controls.

<p><b>(A) unchanged expression, (B) down-regulated expression vs. control and (C) up-regulate expression vs. control.</b> Snord44 was used as housekeeping control for normalization and the relative miRNA expression was calculated using the 2^-ΔΔCT method. con = control, asP = endarterectomy samples of asymptomatic plaques, sP = endarterectomy samples of symptomatic plaques. Data are presented as box plot with median (25^th/75^th percentiles) and whiskers (10^th/90^th percentiles). *P<0.05, **P<0.01, ***P<0.001 vs. con, ^#P<0.05, ^##P<0.01 vs. sP</p

Intersection graph shows miRNAs which were significantly up- (↑) or down-regulated (↓) in endarterectomy specimen from patients with asymptomatic and symptomatic plaques vs. unaffected specimen from the internal mammary artery of healthy controls.

<p>Significant different expression between asymptomatic and symptomatic plaque samples is indicated by an asterisk (*).</p

Target genes of the selected miRNAs and their impact on atherosclerosis.

<p>Target genes of the selected miRNAs and their impact on atherosclerosis.</p