Sperm chromatin structure assay (SCSA®) and flow cytometry-assisted TUNEL assay provide a concordant assessment of sperm DNA fragmentation as a function of age in a large cohort of approximately 10,000 patients

BACKGROUND

Sperm DNA integrity is increasingly seen as a critical characteristic determining reproductive success, both in natural reproduction and in assisted reproductive technologies (ART). Despite this awareness, sperm DNA and nuclear integrity tests are still not part of routine examinations for either infertile men or fertile men wishing to assess their reproductive capacity. This is not due to the unavailability of DNA and sperm nuclear integrity tests. On the contrary, several relevant but distinct tests are available and have been used in many clinical trials, which has led to conflicting results and confusion. The reasons for this are mainly the lack of standardization between different clinics and between the tests themselves. In addition, the small number of samples analyzed in these trials has often weakened the value of the analyses performed. In the present work, we used a large cohort of semen samples, covering a wide age range, which were simultaneously evaluated for sperm DNA fragmentation (SDF) using two of the most frequently used SDF assays, namely the TUNEL assay and the sperm chromatin structure assay (SCSA®). At the same time, as standard seminal parameters (sperm motility, sperm morphology, sperm count) were available for these samples, correlations between age, SDF and conventional seminal parameters were analyzed.

RESULTS

We show that the SCSA® and TUNEL assessments of SDF produce concordant data. However, the SDF assessed by TUNEL is systematically lower than that assessed by SCSA®. Regardless of the test used, the SDF increases steadily during aging, while the HDS parameter (High DNA stainability assessed via SCSA®) remains unchanged. In the cohort analyzed, conventional sperm parameters do not seem to discriminate with aging. Only sperm volume and motility were significantly lower in the oldest age group analyzed [50-59 years of age].

CONCLUSIONS

In the large cohort analyzed, SDF is an age-dependent parameter, increasing linearly with aging. The SCSA® assessment of SDF and the flow cytometry-assisted TUNEL assessment are well correlated, although TUNEL is less sensitive than SCSA®. This difference in sensitivity should be taken into account in the final assessment of the true level of fragmentation of the sperm nucleus of a given sample. The classical sperm parameters (motility, morphology, sperm count) do not change dramatically with age, making them inadequate to assess the fertility potential of an individual.

Integrative Bioinformatics Analysis of The Cell Division Cycle and Ribosomal Pathways in The Rat Varicocele: Implications for Drug Discovery

OBJECTIVE

Varicocele is a common cause of male infertility, affecting a substantial proportion of infertile men. Recent studies have employed transcriptomic analysis to identify candidate genes that may be implicated in the pathogenesis of this condition. Accordingly, this study sought to leverage rat gene expression profiling, along with protein-protein interaction networks, to identify key regulatory genes, related pathways, and potentially effective drugs for the treatment of varicocele.

MATERIALS AND METHODS

In this in-silico study, differentially expressed genes (DEGs) from the testicular tissue of 3 rats were screened using the edgeR package in R software and the results were compared to 3 rats in the control group. Data was obtained from GSE139447. Setting a -11 and P<0.05 as cutoff points for statistical significance, up and down-regulated genes were identified. Based on Cytoscape plugins, protein-protein interaction (PPI) networks were drawn, and hub genes were highlighted. ShinyGO was used for pathway enrichment. Finally, effective drugs were identified from the drug database.

RESULTS

Among the 1277 DEGs in this study, 677 genes were up-regulated while 600 genes were down-regulated in rats with varicocele compared to the control group. Using protein-protein interaction networks, we identified the top five up-regulated genes and the top five down-regulated genes. Enrichment analysis showed that the up-regulated genes were associated with the cell division cycle pathway, while the down-regulated genes were linked to the ribosome pathway. Notably, our findings suggested that dexamethasone may be a promising therapeutic option for individuals with varicocele.

CONCLUSION

The current investigation indicates that in varicocele the cell division cycle pathway is up-regulated while the ribosome pathway is down-regulated compared to controls. Based on these findings, dexamethasone could be considered a future candidate drug for the treatment of individuals with varicocele.