Circulating MicroRNAs as Novel Biomarkers of Stenosis Progression in Asymptomatic Carotid Stenosis

Background and Purpose—Progression of asymptomatic carotid artery stenosis (ACAS) in patients with >50% luminal narrowing is considered a potential risk factor for ischemic stroke; however, subclinical molecular biomarkers of ACAS progression are lacking. Recent studies suggest a regulatory function for several microRNAs (miRNAs) on the evolution of carotid plaque, but its role in ACAS progression is mostly unknown. The aim of our study was to investigate a wide miRNA panel in peripheral blood exosomes from patients with ACAS to associate circulating miRNA expression profiles with stenosis progression. Methods—The study included 60 patients with ACAS carrying >50% luminal narrowing. First, miRNA expression profiles of circulating exosomes were determined by Affymetrix microarrays from plasma samples of 16 patients from the cohort. Second, those miRNAs among the most differentially expressed in patients with ACAS progression were quantified by real-time polymerase chain reaction in a separate replication c...