Transcriptomic analysis of human varicose veins

tRNA-derived fragments (tRFs) with a size of 15-50 nt are derived from mature or precursor tRNAs and associated with a variety of pathological conditions. However, the roles of tRFs in varicose veins (VVs) are largely unknown. The aim of this study was to identify the tRFs involved in VVs and predict their potential biological functions. We first performed small RNA-seq to investigate the expression profiles of tRFs in vascular tissue of VVs patients and healthy controls. In total, 13,789 tRFs were obtained, accounting for 4 % of the total small RNA. Moreover, 45 tRFs were remarkably changed, of which 14 were up-regulated and 31 were down-regulated. Gene Ontology analysis showed that the target genes of these differently expressed tRFs are mainly involved in transcriptional functions, DNA-template and nervous system development. Kyoto Encyclopedia of Genes and Genomes analysis revealed that target genes of these differently expressed tRFs were significantly enriched the wnt signaling pathway and the calcium signaling pathway which regulate local hypoxia and degradation of extracellular matrix(ECM) processes, which play an important role in the development of VVs. Furthermore, differentially expressed mRNA-tRF-non coding RNA regulatory network was constructed which revealed that tRFs may play a central role in this interaction network and correlate with many mRNAs and ncRNAs. Additionally, two up-regulated tRFs (tRF-36-F900BY4D84KRIME and tRF-23-87R8WP9IY) and one down-regulated tRFs (tRF-40-86J8WPMN1E8Y7Z2R)) were identified and verified. These results show that tRFs are aberrantly expressed in vascular tissue of patients with VVs and might play important roles in the development of VVs. Overall design: small RNA-Seq profiles of control healthy, B1-B4; RNA-Seq profiles of case, A1-A4