DNA Fragmentation in Viable and Non-Viable Spermatozoa Discriminates Fertile and Subfertile Subjects with Similar Accuracy

Abstract

Sperm DNA fragmentation (sDF) negatively affects reproduction and is traditionally detected in total sperm population including viable and non-viable spermatozoa. Here, we aimed at exploring the ability of DNA fragmentation to discriminate fertile and subfertile men when detected in viable (viable sDF), non-viable (non-viable sDF), and total spermatozoa (total sDF). We revealed sDF in 91 male partners of infertile couples and 71 fertile men (max 1 year from natural conception) with LiveTUNEL coupled to flow cytometry, able to reveal simultaneously DNA fragmentation and cell viability. We found that the three sDF parameters discriminated fertile and subfertile men with similar accuracy and independently from age and basal semen parameters: AUCs (area under the curves) (95% CI) were: 0.696 (0.615–0.776), p < 0.001 for total sDF; 0.718 (0.640–0.797), p < 0.001 for viable sDF; 0.760 (0.685–0.835), p < 0.001 for non-viable sDF. We also found that total and non-viable but not viable sDF significantly correlated to age and semen quality. In conclusion, the three sDF parameters similarly discriminated fertile and subfertile men. Viable spermatozoa with DNA fragmentation are likely cells able to fertilize the oocyte but failing to properly support subsequent embryo development. Non-viable sDF could be a sign of a subtler damage extended beyond the non-viable cells.

Complete Chromatin Decondensation of Pig Sperm Is Required to Analyze Sperm DNA Breaks With the Comet Assay

“…Previous studies reported that viable spermatozoa can contain DNA breaks, supporting that apparently intact sperm with proper motility may bear fragmented DNA (Pérez-Llano et al, 2010;Samplaski et al, 2015;Muratori et al, 2020). DNA damage can occur in response to oxidative stress, but also as a result of enzymatic activity during chromatin remodeling and/or apoptotic-like processes (Aitken and De Iuliis, 2010;Sakkas and Alvarez, 2010;Bui et al, 2018;Ribas-Maynou and Benet, 2019).…”

Simultaneous detection of sperm membrane integrity and DNA fragmentation by flow cytometry: A novel and rapid tool for sperm analysis

“…In brief, ten of 12 studies reported that none of the participants had SARS-CoV-2 RNA COVID-19 induces respiratory-predominant multiorgan dysfunction, including myocardial, renal, enteric and hepatic dysfunction, which coincides with the tissue expression of ACE2. 3 Meanwhile, several studies have shown that ACE2 is expressed in human testes (eg spermatogonia, Leydig cells and Sertoli cells), 4,5 suggesting that the testes may be another organ affected by COVID-19.…”

“…In previous research using TUNEL+LD for the simultaneous evaluation of membrane integrity and DNA fragmentation, it was evident that DNA fragmentation was largely associated with dead spermatozoa. 6 Furthermore, using the same method Muratori et al 5 reported that it is possible to discriminate the fertility status of men by evaluating the sperm DNA Fragmentation either in live or dead spermatozoa. This could suggest that the increase of DNA fragmentation is proportional in both fractions, allowing the detection of subfertile patients with the same accuracy when compared to fertile subjects.…”

“…3 In this regard, it has long been known that higher sperm DNA damage is prevalent among infertile men than in the fertile ones. [4][5][6] Furthermore, it negatively affects fertilization, embryo development, implantation, and pregnancies in natural reproduction. 7 Likewise, similar observations have been reported on clinical pregnancies following in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI).…”

“…2COVID-19 induces respiratory-predominant multiorgan dysfunction, including myocardial, renal, enteric and hepatic dysfunction, which coincides with the tissue expression of ACE2. 3 Meanwhile, several studies have shown that ACE2 is expressed in human testes (eg spermatogonia, Leydig cells and Sertoli cells), 4,5 suggesting that the testes may be another organ affected by COVID-19.Numerous viruses have been detected in human semen. 6 Viruses may persist in semen and last longer in seminal fluid than in other body fluids due to the immune privilege of the testes and the contribution of the blood-testes barrier to resistance to therapeutic agents.…”