Circulating MicroRNAs as Potential Biomarkers for Ischemic Stroke in Patients with Asymptomatic Intracranial Artery Stenosis.

Circulating microRNAs have been shown to be biomarkers of various diseases. We aimed to investigate whether circulating microRNA can serve as a biomarker to predict ischemic stroke risk in asymptomatic intracranial artery stenosis. A total of 716 participants from the Asymptomatic Polyvascular Abnormalities Community study who had asymptomatic intracranial artery stenosis at baseline were enrolled (2010-11). Patients who suffered incident ischemic stroke were classified into the case group, and age- and sex-matched individuals without stroke were used as controls. MicroRNA microarrays were used to distinguish baseline circulating serum microRNA levels between the case and the control groups (GEO accession number GSE201860). The differentially expressed microRNAs were validated by real-time PCR. MicroRNA microarrays were performed in baseline serum samples from12 subjects who developed ischemic stroke and 12 age- and sex-matched subjects without stroke during the 2014-15 follow-up period. Twenty microRNAs were differentially expressed between the two groups (fold change > 1.3 and p < 0.05 for all). Hsa-miR-486-5p, hsa-miR-92a-3p, hsa-miR-6089 from them were selected and validated in the baseline serum samples of ten subjects with incident ischemic stroke and another ten age- and sex-matched subjects without stroke during the 2016-17 follow-up period. Hsa-miR-1225-5p, with a large fold change value and a reported relationship with cardiovascular or cerebrovascular diseases, was also validated. Ultimately, only hsa-miR-6089 was differentially downregulated among patients with intracranial artery stenosis who developed ischemic stroke (p < 0.05). In patients with asymptomatic intracranial artery stenosis, downregulated serum hsa-miR-6089 may be associated with the risk of ischemic stroke.