ORIGINAL ARTICLE Expression of Egfl7 and miRNA-126-5p in Symptomatic Carotid Artery Disease C xig ˘ dem Sezer Zhmurov, 1,2 O ¨ zlem Timirci-Kahraman, 3 Fatimat’ul Zahara Amadou, 2 Osman Fazlıog ˘ ulları, 4 Cem Bas xaran, 5 Tunc Catal, 6 U ¨ mit Zeybek, 3 and Hakan Bermek 1 Background: Neoangiogenesis inside the atherosclerotic plaques has been linked to progression of the disease. Egfl7, a key player in adult angiogenesis, was found to be upregulated in response to vascular injury in rats. Egfl7 encodes for miR-126-3p and miR-126-5p. Specific information about miRNA-126-5p and its expression in cardiovascular disease is scarce in comparison to that of miR-126-3p. Objectives: A gene expression study was conducted to investigate the levels of Egfl7 and miRNA126-5p in human carotid artery atherosclerotic plaques aiming to gain a better understanding of the role of neoangiogenesis within plaques and the mechanisms causing atherosclerosis progression. Methods: Egfl7 and miR-126-5p levels were studied in 14 plaque samples and 14 control samples using real-time PCR. The fold change between the carotid artery plaque tissue and control tissue was calculated using the 2 -DDCT method. Results: Egfl7 was upregulated in the 11 plaque samples compared to controls, while expression levels of miR-126-5p was higher in eight of the plaque samples and lower in six as compared to control samples. Upregulation of miR-126-5p expression was correlated with high low-density lipoprotein (LDL) cholesterol ( p = 0.023). Conclusions: Our findings suggest that the upregulation of Egfl7 promotes neoangiogenesis within the plaques, contributing to disease progression. Introduction A ccording to the World Health Organization Global Health Observatory Data, cardiovascular dis- eases were the leading cause of death worldwide in 2012 (‘‘Cardiovascular Diseases,’’ WHO, 2015). Coronary heart disease and strokes were responsible for 47.7% and 16.4% of the deaths, respectively. The consequences of the strokes suffered by more than 15 million people everyday worldwide are permanent disabilities and deaths (Lloyd-Jones et al., 2010). Among the several risk factors associated with car- diovascular diseases, the most important ones are high blood pressure, smoking, diabetes mellitus, high blood cholesterol and other lipids, family history of cardiovascular disease, physical inactivity, and obesity ( Jashari et al., 2013; Mo- zaffarian et al., 2015). The main cause of stroke is carotid artery disease, occurring due to the blockage in the carotid arteries that supply blood to the brain (Sobieszczyk and Beckman, 2006). To reduce the risk of future cerebrovascular events, carotid endarterectomy is performed in patients with symptomatic carotid artery disease. Arterial blockage is caused by atherosclerosis; a chronic and inflammatory disease of the medium and large arteries. The characteristic lesion of atherosclerosis is atheroma- tous plaque deposited in the vascular bed, developing due to endothelial dysfunction. Atherosclerotic plaques occur es- pecially at arterial branch points, such as the carotid, fem- oral, and aortic bifurcations, where the laminar flow is disturbed and where there is significant turbulence. Ather- osclerosis alone is rarely fatal. Acute coronary syndrome, myocardial infarction, or stroke occurs as thrombosis emerges upon unstable vulnerable plaque rupture; and it is these acute cardiovascular syndromes that cause death (Falk, 2006; Mughal et al., 2011; Weber and Noels, 2011; Schiro et al., 2014). Although how an asymptomatic fi- broatheroma is converted to a lesion that is vulnerable to rupture is not clear, there are many studies linking plaque neoangiogenesis with progressive atherosclerotic disease and the development of acute lesion instability. It is widely suggested that neoangiogenesis causes stenosis, intraplaque hemorrhage, and thrombosis (Kolodgie et al., 2007; Schiro et al., 2014). 1 Department of Molecular Biology and Genetics, Istanbul Technical University, Istanbul, Turkey. 2 Department of Genetics and Bioengineering, Istanbul Bilgi University, Istanbul, Turkey. 3 Department of Molecular Medicine, Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey. 4 Department of Cardiovascular Surgery, Medical Park Gebze Hospital, Kocaeli, Turkey. 5 Department of Cardiovascular Surgery, Medicana Bahcelievler Hospital, Istanbul, Turkey. 6 Department of Molecular Biology and Genetics, Uskudar University, Istanbul, Turkey. GENETIC TESTING AND MOLECULAR BIOMARKERS Volume 00, Number 00, 2016 ª Mary Ann Liebert, Inc. Pp. 1–5 DOI: 10.1089/gtmb.2015.0252 1