Differential MicroRibonucleic Acid Expression in Cardioembolic Stroke.

BACKGROUND: MicroRNAs (miRNA) are a class of small, endogenous (17-25 nucleotide) noncoding ribonucleic acids implicated in the transcriptional and post-transcriptional regulation of gene expression. This study examines stroke-specific miRNA expression in large vessel territory cardioembolic stroke. METHODS: Peripheral blood was collected from controls and ischemic stroke patients 24 hours after stroke onset. Whole blood miRNA was isolated and analyzed for differential expression. A total of 16 patients with acute middle cerebral artery territory strokes of cardioembolic origin were included in this pilot study. MiRNA profiling was conducted by miRCURY LNA™ microRNA Array. RESULTS: In patients with cardioembolic stroke, significant differential expression of 14 miRNAs was observed when compared to controls. Ten of these miRNA had not previously been associated with ischemic stroke (miR-664a-3p, -2116-5pp, -4531, -4765-5p, -647, -4709-3p, -4742-3p, -5584-3p, -4756-3p, and -5187-3p). Subanalysis of severe strokes (NIHSS > 10) identified an additional 5 differentially expressed miRNA. No significant effects of sex or tissue plasminogen activator treatment were seen on miRNA expression. CONCLUSIONS: Ischemic stroke patients show a differential miRNA expression profile as compared to controls. These new associations between circulating miRNAs and ischemic stroke may help to refine stroke subtype diagnosis and identify novel therapeutic miRNA targets for the treatment of ischemic stroke.