Plaque vulnerability is associated with the degree of carotid artery stenosis (CS) and the risk of stroke. MicroRNAs (miRNAs) exert critical functions in disease progression, although only a few miRNAs have been well identified in CS. Therefore, this study aimed to investigate the differential expression profile of miRNAs and their potential functions in plaques of CS patients. Three CS patients with stable plaques and three patients with vulnerable plaques who underwent carotid endarterectomy were enrolled in this study. Differentially expressed miRNAs (DEmiRNAs) between patients with stable and vulnerable plaques were determined using small RNA sequencing. Target genes of DEmiRNAs were predicted and submitted to functional analyses. Validation of dysregulated DEmiRNAs was determined using quantitative real-time polymerase chain reaction (qRT-PCR). After sequencing, 76 DEmiRNAs were identified in vulnerable plaques, including 53 upregulated miRNAs and 23 downregulated miRNAs. Next, 23,495 target genes of the identified DEmiRNAs were predicted and functionally analyzed. This indicated that the target genes of the identified DEmiRNAs were mainly enriched in protein phosphorylation, transcription, nitrogen compound metabolism, endocytosis and autophagy, and related to signaling pathways of Hippo, MAPK, insulin, TGF-β, FoxO, AMPK and p53. Furthermore, qRT-PCR results for six miRNAs showed that five (83%) of them (hsa-miR-511-5p, hsa-miR-150-5p, hsa-miR-378a-5p, hsa-miR-365b-5p and hsa-miR-6511b-5p) were consistent with the sequencing results. Differential expression profiles and potential function of miRNAs associated with plaque stability in CS patients are identified for the first time, which should help to understand the regulatory mechanism of plaque stability in CS.
Keywords: carotid artery stenosis; differentially expressed miRNAs; qRT-PCR.