Extent Of Sperm DNA Fragmentation Research Articles

Semen Quality is Associated with Sperm Aneuploidy and DNA Fragmentation in the United Arab Emirates Population.

Background: Sperm chromosome aneuploidy and the extent of sperm DNA fragmentation (SDF) are contributing factors to male infertility. Their extent can be measured using platforms such as sperm chromatin dispersion (SCD) and sperm fluorescence in situ hybridization (sFISH). Additional studies, however, are needed to understand the clinical applicability of these in vitro tests based on statistically validated thresholds. Aim: The primary objective of this study was to report the incidence of SDF and chromosomal aneuploidy with respect to sperm quality in the United Arab Emirates (UAE) population. In addition, we wished to establish clinically useful SDF and aneuploidy cutoff values. Materials and Methods: A total of 302 subjects were enrolled in this study. The control group consisted of n = 100 (33.11%) reproductively-proven fertile men, and the case group consisted of n = 202 (66.89%) infertile men. The sperm quality of the cases was further subclassified as normospermia ("Normo," n = 88; 43.56%); teratozoospermia ("T," n = 40; 19.80%); oligoasthenoteratozoospermia ("OAT," n = 37; 18.32%); asthenoteratozoospermia ("AT," n = 19; 9.41%); or oligoteratozoospermia ("OT," n = 18; 8.91%). The assessments of SDF were done using SCD tests. Chromosomal aneuploidy (Chr 13, 18, 21, X, and Y) was investigated using sFISH. Furthermore, based on the fragmentation index, cases were divided into subfertile groups defined as low, medium, high, and severe. The Mann-Whitney test was used to set the upper threshold value for sFISH, and the odds ratio was used for SDF assessment. Results: Cases having sperm quality "AT," "OAT," and "OT" together with the moderate, high, and severe subfertile groups had the highest DNA fragmentation indices: 31.58%, 27.03%, and 22.22%, respectively. In the sFISH analyses, groups with sperm quality "OAT," "T," and "OT" exhibited high degrees of abnormalities: 86.49%, 52.50%, and 50%, respectively. The most common chromosomal abnormalities found were "sex chromosome hyperploidy (XY18)" and "diploid (Chr 13, 21)." The incidences of sperm quality with respect to SDF and sFISH are also reported in detail. Conclusions: This is the first study in the UAE which shows SDF and sFISH incidences together with sperm quality. This study also establishes SDF and sFISH cutoff values for the UAE population.

The higher risk for sperm DNA damage in infertile men.

Supplementary assays are needed for determination of relationships between sperm biomarkers and fertility potential. Therefore, our research was designed to determine the extent of sperm DNA fragmentation (SDF) and establish a discriminating threshold of SDF for fertility potential. Semen characteristics were evaluated according to World Health Organization recommendations, and SDF was assessed by sperm chromatin dispersion test on ejaculated spermatozoa from infertile and healthy normozoospermic men. A higher proportion of SDF was noted in infertile men (median 23.00%) than normozoospermic (median 14.00%). Significantly less subjects (17.03%) with low SDF level (≤ 15%) and more (35.17%) with high SDF level ( > 30%) were found for the infertile group vs the normooospermic (57.90% and 5.26%, respectively). Infertile group had significantly lower odds ratio (OR) for having a low SDF level (OR: 0.1493) and higher OR for having a high SDF level (OR: 9.7627). Receiver operating characteristic analysis [area under curve (AUC) = 0.785] revealed that 20% SDF is predictive value for discriminating between infertile and normozoospermic subjects. SDF was negatively correlated with the sperm number, morphology, progressive motility and vitality but positively with the teratozoospermia index. Our study demonstrates: (1) a significant difference in the extent of SDF and in the risk for having damaged sperm DNA between infertile and normozoospermic men, (2) > 20% SDF has negative predictive value for fertility potential, (3) coexistence of abnormal standard sperm parameters with sperm chromatin damages. Therefore, SDF should be considered as a highly valuable indicator of male fertility potential.

45 DNA Fragmentation of Epididymal Freeze-Dried Ram Spermatozoa Impairs Embryo Development

Sperm freeze-drying is a revolutionary technique that resolves many of the drawback of long-term storage under liquid nitrogen. The first significant result of this method was provided by Wakayama and Yanagimachi (1998 Nat. Biotechnol. 16, 639-641, 10.1038/nbt0798-639), demonstrating for the first time the birth of healthy offspring from epididymal freeze-dried (mouse) spermatozoa. Besides models in the mouse and rat, which are the first small mammals born from epididymal lyophilized sperm by intracytoplasmic sperm injection (ICSI), most studies in this field have used ejaculated sperm. In this work, aiming to repeat the result of Wakayama and Yanagimachi, we tried to apply this technique to epididymal spermatozoa from a large mammal (ram). Moreover, we checked the correlation between freeze-dried spermatozoa DNA integrity and embryo development. To do this, epididymal sperm from 4 rams was lyophilized in a medium containing trehalose, glucose, KCl, HEPES, and Trolox. To evaluate DNA damage and fragmentation at rehydration, part of the sperm was processed for sperm chromatin dispersion test (SCD) and two-tailed comet assay and the rest was used for ICSI. Compared with rams 1 and 3, rams 2 and 4 had higher rate of spermatozoa with intact DNA (median: 3.3% v. 16.5%, respectively), lower rate of single strand breaks (SSB; median: 94.2% v. 81.5%, respectively) and lower rate of double-strand breaks (DSB; median: 2.5% v. 2%, respectively). Embryo development following ICSI showed that blastocyst stage was reached only from rams that had sperm with more intact DNA: ram 2 (4.8%, n = 83) and ram 4 (6.3%, n = 64). Spermatozoa from rams 1 and 3 produced no blastocysts. This can be explained by the fact that rams 2 and 4 had higher rate of spermatozoa with intact DNA than rams 1 and 3. Definitively, the implication of sperm DNA damage in embryonic development should depend on the balance between the extent of sperm DNA fragmentation, the type of fragmentation (SSB or DSB), and the oocyte’s repair capacity. Rams 2 and 4 were the only rams that produced blastocyst probably because they had considerably more sperm with normal DNA; thus, it is important to select spermatozoa of the best quality to perform a good ICSI. Fragmentation of DNA due to the lyophilization process impairs embryonic development. To conclude, oocytes injected with epididymal freeze-dried ram spermatozoa can reach the blastocyst stage. These are preliminary results; more conclusive outcomes will be given following embryo transfer experiments that are now in progress.

The quality of sperm preparation medium affects the motility, viability, and DNA integrity of human spermatozoa.

AIM:The goal was to compare the effects of three different sperm preparation media on sperm motility, viability, and DNA integrity of semen samples from normozoospermic men.METHODS:A total of 15 normozoospermic males were included in the study. The semen analysis (SA) was performed in accordance with the WHO guidelines (2010). After SA, each sample was divided into three aliquots, and swim-up was performed with three different sperm preparation media (Sperm Preparation Media, Origio, Denmark; Ham's F10, Biochrome, Berlin, Germany; and VitaSperm™, Innovative Biotech, Iran). Sperm motility, viability, and DNA fragmentation were evaluated at 0, 1, 2, and 24 h after swim-up.RESULTS:There were no significant differences, at any time intervals, in the total sperm motility between the different sperm preparation media. However, the rate of progressive motility was significantly higher in spermatozoa prepared using the media from Origio in comparison with VitaSperm™ (P = 0.03), whereas no significant difference was found against Ham's F10 medium. No significant differences in sperm viability were seen between the media products. However, 1 h after swim-up, the extent of sperm DNA fragmentation was lower in the medium from Origio versus VitaSperm™ (P = 0.02).CONCLUSIONS:The data showed that the quality of medium for preparation of semen samples from normozoospermic men significantly affects the performance of spermatozoa in assisted conception programs.

Sperm cyropreservation and oxidative damage. What does it mean?

Sperm cyropreservation and oxidative damage. What does it mean?

Association between the extent of DNA damage in the spermatozoa, fertilization and developmental competence in preimplantation stage embryos

To examine the fertilizing ability and DNA damage response of preimplantation stage embryos derived from the γ-irradiated mouse sperm carrying varying amounts of DNA strand-breaks. The DNA damage in the sperm was induced by exposing the testicular area to different doses of γ-radiation. After mating with healthy female mice, sperm zona binding, fertilizing ability of DNA damaged sperm and developmental competence of embryos derived from the DNA damaged sperm were assessed. The in vivo zona binding ability and fertilizing ability of DNA damaged sperm was significantly affected in the 5.0 and 10.0 Gy sperm irradiation groups. Although the development of the embryos derived from the DNA damaged sperm was not significantly affected until day 2.5 post-coitus, further development was significantly altered, as evidenced by the total cell number in the embryos. The sperm carrying DNA strand breaks still has the ability to fertilize the oocyte normally. However, the events like zona-binding and successful fertilization depend on the extent of sperm DNA fragmentation. The study has also showed a great heterogeneity in embryonic development at peri-implantation period with respect to the degree of sperm DNA damage.

Sperm chromatin damage and its role in the pathogenesis of infertility in patients with endometriosis

Factors that contribute to infertility in patients diagnosed with endometriosis, especially those with little or no distortion of their pelvic anatomy are poorly understood. This study sought to 1) evaluate the effect of coincubation of peritoneal fluid (PF) from patients with and without endometriosis on the extent of sperm DNA fragmentation, and 2) assess if DNA damage is consistent across PF from patients with endometriosis.

Sperm selection by swim-up in terms of deoxyribonucleic acid fragmentation as measured by the sperm chromatin dispersion test is altered in heavy smokers

Toxic habits and their relationship with male factor infertility have been a matter of investigation in recent years, and smoking is one of the most common lifestyle toxic exposures to harmful substances. The analysis of sperm deoxyribonucleic acid fragmentation after capacitation detected a detrimental effect produced by tobacco, and this deleterious effect alters the sperm swim-up selection process in smokers, although the molecular and cellular basis of this phenomenon remain to be elucidated.

P-849: Coincubation of peritoneal fluid from endometriosis patients with spermatozoa and its correlation with extent of DNA fragmentation

Oxidative stress and reactive oxygen species (ROS) in semen decrease sperm membrane integrity and consequently sperm function due to DNA damage. Evidence shows that endometriosis is a disease of oxidative stress. The objective of this study was to examine the effect of coincubation of peritoneal fluid of endometriosis patients on the extent of sperm DNA fragmentation.

Sperm DNA fragmentation: threshold value in male fertility

The extent of sperm DNA fragmentation, which can be measured by the TUNEL assay, is one of the determinants of male fertility. However, the clinical application of this test to in-vivo situations is difficult owing to the absence of a statistically validated threshold value. The aim of this study was to compare the results of TUNEL assay applied to semen samples from men of proven fertility (n = 47) and patients from an infertile population (n = 66), in order to establish a discriminating threshold value. Infertile patients had a higher mean level of DNA fragmentation than men of proven fertility (40.9 +/- 14.3% versus 13.1 +/- 7.3%, respectively; P < 0.001). The area under the receiver operating characteristics curve was 0.93 for 20% sperm DNA fragmentation. The calculated threshold value for TUNEL assay to distinguish between fertile controls and infertile men was 20%. At this threshold, specificity was 89.4 [95% confidence interval (CI) 83.7-95.1] and sensitivity was 96.9% (95% CI 93.8-100). The positive and negative predictive values of the 20% sperm DNA fragmentation threshold were high: 92.8% (95% CI 87.9-97.5) and 95.5% (95% CI 91.6-99.3), respectively. This study demonstrates that sperm DNA fragmentation, as measured by TUNEL assay, is a highly valuable indicator of male fertility.