Objective: To investigate the regulatory mechanism of miRNAs on intimal hyperplasia of the vein graft through analyzing the expression profile of microRNAs (miRNAs) of autologous vein graft in rats.
Methods: The rat vein graft models were established by grafting the autologous external jugular vein into the infrarenal abdominal aorta. The vein grafts were harvested on postoperative day (POD) 3 and 14, using the normal rat external jugular veins as control, and then, the miRNA expression profiles were determined by high-throughput sequencing after total RNA extraction, the differentially expressed miRNAs were screened out and their target genes were estimated. Finally, GO enrichment analysis and KEGG pathway analysis of the target genes were performed.
Results: Compared with the normal vein, the total number of differentially expressed in the vein graft miRNAs on POD 14 was 265, in which, 183 miRNAs were up-regulated and 82 miRNAs were down-regulated. There were 158 differentially expressed miRNAs between the vein graft on POD 14 and POD 3, including 94 up-regulated miRNAs and down-regulated 64 miRNAs. The GO analysis of the target genes of the miRNAs showed that the enriched genes were mainly involved in the regulation of DNA transcription, the regulation of intercellular signal transduction and the regulation of protein phosphorylation. The KEGG pathway analysis showed that the enriched pathways were MAPK signaling pathway, cAMP signaling pathway, Wnt signaling pathway, tight junction and cGMP-PKG signaling pathway.
Conclusion: MiRNAs participate in the biological process of intimal hyperplasia of the vein graft through complex regulatory networks. The discovered miRNA and their regulatory networks may provide the reference framework for investigating the mechanism of intimal hyperplasia of the vein graft and its interventions.