Screening and Functional Analysis of tsRNAs Associated with Diabetic Foot Ulcer Tissues

<b>Background</b>: Diabetic foot ulcer (DFU) is a serious complication of diabetes mellitus, and its inability to heal is closely linked to vascular pathology. However, the specific molecular regulatory networks involved remain unclear. This study hypothesizes that tRNA-derived small RNAs (tsRNAs) may be associated with endothelial dysfunction in DFU. <b>Methods</b>: RNA sequencing (RNA-seq) was performed on DFU (<i>n</i> = 3) and healthy foot skin (<i>n</i> = 3) samples. Bioinformatics analysis identified differential expression of tsRNAs, with the ten most significantly differentially expressed tsRNAs validated by qRT-PCR. Target gene prediction and GO/KEGG enrichment analysis were then conducted on the four tsRNAs that demonstrated significant differential expression, as confirmed by qRT-PCR. <b>Results</b>: The results revealed that there were 49 differentially expressed tsRNAs between the two groups of samples. qRT-PCR validation confirmed that the expression trends of ten tRNAs were consistent with sequencing results. Among these, the 4770 potential target genes of four tRNAs exhibiting significant expression differences primarily encompassed the cell growth factor family and the Smad protein family. GO analysis revealed that the target genes were located mainly in the cytoplasm and organelle membranes and functioned by specifically binding to DNA in the transcriptional regulatory regions. KEGG pathway enrichment revealed that the differential tsRNAs were closely associated with pathways involved in cytoplasmic lysis and phagocytosis and the transforming growth factor beta (TGF-β) signaling pathway. <b>Conclusions</b>: This study systematically reveals the differential expression profile of tissue-specific tsRNAs in DFU tissue, thereby enriching the molecular pathological theory underlying the poor healing capacity of DFU. It also provides experimental evidence for the clinical translation of tsRNAs as early diagnostic markers for DFU.