Purpose Reactive oxygen species (ROS) and oxidative stress is one of the main reasons of male infertility. MicroRNAs (miRNAs) regulate multiple intracellular processes. Alterations in miRNAs expression may occur in different conditions and diseases. In this study, the effect of oxidative stress induced by tertiary-butyl hydroperoxide (TBHP) on the expression of candidate miRNAs in mouse testis was investigated.Methods After determining median lethal dose (LD 50 ), TBHP was intraperitoneally (ip) injected at the dilution of 1:10 LD 50 into the adult male mice for 2weeks, and then testis tissues were removed in order to assay the ROS level. Total RNA was extracted and the expression of five miRNAs was quantified by reverse transcription-real time polymerase chain reaction (RT-qPCR).Results The flow cytometry analysis showed a significant increase in ROS level in testis. The expression of three out of five selected miRNAs, including miR-34a, miR-181b and miR-122a, showed some degrees of changes following exposure to oxidative stress. These miRNAs are involved in antioxidant responses, inflammation pathway and spermatogenesis arrest. Conclusions In conclusion, TBHP alters the miRNA expression profile of testis which might play a potential role in oxidative and antioxidative responses and spermatogenesis.

Summary Male infertility is responsible for approximately 50% of infertility worldwide. Reactive oxygen species are one of the major causes of male infertility. In this study, the effects of oxidative stress induced by tertiary‐butyl hydroperoxide (TBHP) on sperm quality and testis tissue are investigated. After determination of LD50, TBHP with a concentration of 1 : 10 LD50 was injected in adult male mice strains Balb/c for two consecutive weeks. Their testis tissues were used for cell viability, histopathology analysis and ROS assay. The epididymis was also surveyed for sperm analysis by CASA system. The sperm motility, count and viability decreased in the TBHP‐treated mice compared to the control mice. The flow cytometry analysis showed a significant increase in H2O2 and O2 ·− levels in both testis and sperm within 2 weeks after intraperitoneal injection. Body weights revealed no treatment‐related effects, but atrophy of testis and a decrease of testis cells viability were observed. The results showed that exposure to TBHP could lead to morphological changes in seminiferous tubules. TBHP‐induced oxidative stress caused a decrease in sperm parameters and testis cells viability. That is due to an increase level of ROS in the testis and their deleterious effects on genomic levels.

Our nomogram based on age, DRE, PSA, %fPSA and TRUS finding was significantly more accurate in predicting initial prostate biopsy outcome in men.