Differential Expression of Platelet-derived Exosomal MicroRNAs in Patients with In-Stent Restenosis: A Pilot Study

Background: This study was conducted to identify differences in platelet-derived exosomal microRNA (miRNA) profiles between patients with in-stent restenosis (ISR) and those without restenosis using RNA sequencing. Methods: Platelet-derived exosomes (PDEs) were isolated via ultracentrifugation and validated through western blotting, transmission electron microscopy, and NanoSight analysis. The miRNA expression profiles of PDEs from three patients with restenosis and three without restenosis were identified using Illumina Hiseq2000 sequencing, whereas the differential expression of PDEs miRNAs in 20 patients, including 10 with restenosis and 10 without, was validated via quantitative real-time polymerase chain reaction (qRT-PCR). Finally, the potential functions of the miRNAs were predicted using miRNA-gene-Gene Ontology (GO) and miRNA-gene-Kyoto Encyclopedia of Genes and Genomes (KEGG) networks. Results: Several differentially expressed PDE miRNAs were identified.Particularly, miRNA PC-3p-75179_24 was upregulated, whereas hsa-miR-133a-3p_R+1 and hsa-miR-589-5p_R-1 were downregulated in patients with ISR, as validated by qRT-PCR. Our results also revealed potential miRNA-gene-GO and miRNA-gene-KEGG interactions. GO functional analysis of miRNAs with statistically significant differential expression revealed their primary distribution in areas related to cell growth, protein binding, and transferase activity. KEGG pathway analysis revealed enrichment of pathways associated with differentially expressed miRNAs, including Rap1, cAMP, AMPK, adrenergic, and autophagy signaling pathways in cardiomyocytes. Conclusions: In this study, we identified one significantly upregulated and two significantly downregulated miRNAs. Our findings reveal, for the first time, alterations in miRNA expression within the PDEs of patients with ISR, notably the upregulation of miRNA PC-3p-75179_24 and the downregulation of has-miR-133a-3p_R+1 and hsa-miR-589-5p_R-1. These results support further exploration of these miRNAs as potential biomarkers and their pathological implications on ISR, offering new insights into future diagnostic markers.