Atherosclerosis-Related Circulating MicroRNAs as a Predictor of Stroke Recurrence

MicroRNAs (miRNAs) are short sequenced non-coding RNAs that posttranscriptionally regulate gene expression. We investigated circulating miRNA expression levels in acute stroke patients and its relationship with future vascular event. We included acute ischemic stroke patients who admitted to a university hospital between May 1, 2011, and July 31, 2012, and the patients with vascular risk factors but not incident stroke as controls. We collected 5 ml of venous blood, and circulating miRNA levels were evaluated by quantitative real-time polymerase chain reaction. Five miRNAs (miR-17, miR-21, miR-106a, miR-126, and miR-200b), which had been reported to be related to atherosclerosis, were measured. The levels of miRNAs were compared with the presence of acute stroke, vascular risk factors, stroke subtypes, and stroke recurrence after index stroke. A total of 120 patients were included in the study, with 83 acute stroke patients. The levels of miR-17 were significantly increased in acute stroke patients, and the levels of miR-126 had positive correlation with cerebral atherosclerosis (r = 0.254, p = 0.021). Among the 83 stroke patients, eight experienced stroke recurrence during follow-up and higher level of miR-17 was associated with shorter event-free survival (p = 0.047). This study shows that the miR-17 level was elevated in acute ischemic stroke and associated with future stroke recurrence.