tRNA-Derived Fragments in Seminal Plasma Exosomes Are Non-invasive Biomarkers for Diagnosis of Non-obstructive Azoospermia With Spermatogenic Failure

Abstract BackgroundThere is lack of accurate and non-invasive preoperative evaluation for improving microdissection testicular sperm success rate. tRNA-derived small RNA (tsRNAs) perform a variety of physiological functions and are related to many physiological and pathological processes. This study sought to identify the potential of exosomal tsRNA as a novel non-invasive diagnostic biomarker for non-obstructive azoospermia (NOA) with spermatogenic failure.MethodsSeminal plasma exosome tsRNA levels were used in a two-stage (screened by tsRNA sequencing on Illumina NextSeq instrument and validated by qRT-PCR) case-control designed study. The expression levels of the selected tsRNAs were further examined in the testicular tissues of NOA patients and obstructive azoospermia (OA) patients, and their underlying role in the pathogenesis of non-obstructive azoospermia was performed by bioinformatic analysis.ResultsIn this study, two tsRNAs (tRF-Val-AAC-010: AUC = 0.96, specificity = 80%, sensitivity = 95%; tRF-Pro-AGG-003: AUC = 0.96, specificity = 87%, sensitivity=95%) were found to have a good predictive accuracy which also showed differential expression in testicular tissue between NOA patients and OA patients. We also found that the combinations of tRF-Val-AAC-010 and tRF-pro -AGG-003 have a better discriminating ability between NOA patients and OA patients than single biomarkers. Finally, the bioinformatic analysis showed that the two selected tsRNAs were involved in spermatogenesis.ConclusionThis study first evaluated tsRNAs as potential biomarkers for NOA diagnosis and identified the exosomal tRF-Val-AAC-010 and tRF-pro-AGG-003 in seminal plasma valuable as biomarkers for NOA diagnosis.