DNA fragmentation in brighter sperm predicts male fertility independently from age and semen parameters

Apoptotic-Related MiRNAs Correlated with Functional and Flow Cytometric Parameters in Asthenozoospermic Holstein Bulls After Freeze-Thaw Process

Many cellular processes in spermatozoa, including apoptosis and motility, are regulated by miRNA. Different miRNAs and molecular pathways are involved in asthenozoospermia (AS) conditions, which are thought to be one of the causes of infertility with reduced sperm motility. Thirty-two semen samples from four Holstein bulls with normozoospermia (NS), total motility ≥ 70%, and progressive motility ≥ 60%, and 32 semen samples from four bulls with AS, total motility ≤ 40%, and progressive motility ≤ 32% were used to investigate the function of apoptosis-related miRNAs in the AS group. Samples were then aspirated into a 0.5 mL straw after dilution with a Tris-egg yolk extender and frozen at -196°C. After freezing, semen samples were thawed for 2 weeks at 37°C and sperm kinematic parameters, plasma membrane integrity, acrosome integrity, DNA fragmentation, apoptosis status, and expression of apoptosis-related miRNAs (miR-2114, miR-296-3p, miR-455-3p, and miR345-3p) were evaluated. Our results showed that the functional and flow cytometric parameters of the NS group were significantly better than those of the AS group. In the NS group, miR-455-3pp and miR-2412 were upregulated, while miR-345-3p was downregulated compared with the AS group. In the AS group, miR-296-39, miR-2412, and miR-345-3p levels were strongly correlated with membrane integrity, DNA fragmentation, and apoptosis status. The findings demonstrated that the selected miRNAs based on bioinformatic analysis in AS and NS samples had a substantial association with functional and flow cytometry indicators and may be involved in regulating apoptosis and motility in AS samples.

Sperm DNA Fragmentation in Male Infertility: Tests, Mechanisms, Meaning and Sperm Population to Be Tested

Sperm DNA fragmentation (sDF) is a DNA damage able to predict natural conception. Thus, many laboratories added tests for the detection of sDF as an adjunct to routine semen analysis with specific indications. However, some points related to sDF are still open. The available tests are very different each from other, and a direct comparison, in terms of the prediction of reproductive outcomes, is mandatory. The proposed mechanisms responsible for sDF generation have not yielded treatments for men with high levels of sDF that have gained the general consent in clinical practice, thus requiring further research. Another relevant point is the biological meaning to attribute to sDF and, thus, what we can expect from tests detecting sDF for the diagnosis of male infertility. SDF can represent the "tip of iceberg" of a more extended and undetected sperm abnormality somehow impacting upon reproduction. Investigating the nature of such a sperm abnormality might provide novel insights into the link between sDF and reproduction. Finally, several studies reported an impact of native sDF on assisted reproduction technique outcomes. However, to fertilise the oocyte, selected spermatozoa are used where sDF, if present, associates with highly motile spermatozoa, which is the opposite situation to native semen, where most sDF associates with non-viable spermatozoa. Studies comparing the impact of sDF, as assessed in both native and selected spermatozoa, are needed.

A 2-step remote TUNEL approach for sperm DNA fragmentation assessment. Analysis in donors and patients

OBJECTIVES

Infertility is a disease of the male or female reproductive systems. Male reproductive workup is based on routine semen analysis, although of limited value. The 2021 WHO Manual incorporated Sperm DNA Fragmentation (SDF) assessment, and highlighted the need for individual laboratories to define suitable thresholds. This study aimed to present an alternative to address this issue, determine an SDF cut-off value with fertile donors, and characterize SDF in a patient cohort and their relationship with semen parameters.

STUDY DESIGN

A service unit was established to remotely perform TUNEL assay in a 2 step-process. Semen samples were received at andrology laboratories, subjected to routine semen analysis (WHO, 2010), partially processed and transported to the service unit for SDF evaluation. Using this setting, studies were done in fertile donors (n = 15) to define the cut-off value, and in men undergoing infertility workup (n = 318).

RESULTS

A cut-off value of 9.17 % was determined with the fertile donor cohort. With this cut-off, a 64.46 % abnormal SDF incidence was determined in the patient cohort. SDF negatively correlated with sperm number, vitality and motility, and positively with abnormal morphology and male age (P < 0.05). TUNEL-positive cases depicted lower sperm quality and higher male age (P < 0.05). A similar abnormal SDF incidence was determined among patients with semen abnormalities. Asthenozoospermic and ≥40 years patient samples depicted higher (P < 0.05) SDF than those of the general population. SDF incidence was also high in normozoospermic patients.

CONCLUSIONS

Using a 2-step remote approach with a standardized procedure and an SDF cut-off value established with fertile donors, high SDF incidence in semen samples depicting normal and abnormal quality were identified in men consulting for infertility, highlighting the relevance of its evaluation as part of the male fertility workup.

Correlation of MTHFR C677T Polymorphism with Male Infertility among Indian Population: Case-Control Study

This case-control study investigated the correlation between male infertility in India and the methylenetetrahydrofolate reductase (MTHFR) C677T variant. Infertile males were utilized as the case group in the study, whereas fertile individuals served as the control group. The C677T polymorphism was genotyped using PCR-RFLP analysis (polymerase chain reaction-restriction fragment length polymorphism). The Chi-square test and odds ratio calculation were implemented in the statistical analysis method for assessing the correlation between the C677T mutation and infertility. The results of this study revealed that the case group (9.4%) had a substantially greater prevalence of the C677T variation than the control group (1.6%). The C677T variation is significantly associated with male infertility by the Chi-square test (P value: 0.006). According to these results, the MTHFR gene›s C677T variation may increase the incidence of male infertility in the Indian population. Additional evaluations were also conducted to investigate the association between the C677T variation and particular infertility indicators. The C677T variation has been demonstrated to have been significantly correlated with a low or missing sperm count (p 0.05). These findings highlight the potential function of the MTHFR gene in reproductive health and advance our understanding of the genetic underpinnings of male infertility. It is encouraged to investigate the underlying mechanisms and additional investigation of the underlying mechanisms and to support the creation of individualized approaches to diagnosing and managing male infertility.

Sperm Chromatin Dispersion Test Detects Sperm DNA Fragmentation Mainly Associated with Unviable Spermatozoa and Underestimates the Values with Respect to TUNEL Assay

Several clinical laboratories assess sperm DNA fragmentation (sDF) in addition to semen analysis in male infertility diagnosis. Among tests evaluating sDF, TUNEL (Terminal deoxynucleotidyl transferase dUTP nick end labeling) and SCD (Sperm Chromatin Dispersion) are widely used. Our lab developed a modified version of TUNEL (TUNEL/PI) able to distinguish two sperm populations (PI Brighter and PI Dimmer) differently associated with sperm viability and reproductive outcomes. The aim of this study was to compare sDF levels detected by SCD and TUNEL/PI in the semen samples from 71 male subjects attending our Andrology Laboratory. Our results demonstrate that SCD is less sensitive in determining sDF compared to TUNEL/PI. The statistically significant positive correlation found between sDF evaluated by SCD and PI Dimmer (consisting of all dead spermatozoa) suggests that SCD mainly detects sDF in unviable spermatozoa. We confirmed that most spermatozoa detected by SCD are unviable by performing SCD after incubation in hypo-osmotic medium to discriminate viable and unviable cells in 52 samples. Such results might explain the lower ability of this test in discriminating couples having successful ART outcomes demonstrated in published metanalyses. Overall, our results indicate that SCD is less sensitive in evaluating sDF for diagnostic purposes.

Severe sperm DNA fragmentation may persist for up to 3 years after cytotoxic therapy in patients affected by Hodgkin lymphoma and non-Hodgkin lymphoma

STUDY QUESTION

Does sperm DNA recover from damage in all men after 2 years from the end of cytotoxic treatments?

SUMMARY ANSWER

The current indication of 2 years waiting time for seeking natural pregnancy after cytotoxic treatment may not be adequate for all men, since severe sperm DNA damage is present in a proportion of subjects even after this timeframe.

WHAT IS KNOWN ALREADY

Data in the literature on sperm DNA fragmentation (SDF) in lymphoma patients after cytotoxic treatments are scarce. The largest longitudinal study evaluated paired pre- and post-therapy (up to 24 months) semen samples from 34 patients while one study performed a longer follow-up (36 months) in 10 patients. The median/mean SDF values >24 months after therapy did not show significant differences but the studies did not explore the proportion of patients with severe DNA damage and the analysis was done on frozen-thawed samples.

STUDY DESIGN, SIZE, DURATION

In this study, 53 Hodgkin lymphoma (HL) and 25 non-Hodgkin lymphoma (NHL) post-pubertal patients were included over a recruitment period of 10 years (2012-2022). Among them, 18 subjects provided paired semen samples for SDF analysis at the three time points. SDF was evaluated in patients before (T0) and after 2 (T2) and 3 years (T3) from the end of, cytotoxic treatments (chemotherapy alone or in combination with radiotherapy). A cohort of 79 healthy, fertile, and normozoospermic men >18 years old served as controls (recruited between 2016 and 2019).

PARTICIPANTS/MATERIALS, SETTING, METHODS

SDF was evaluated on fresh semen samples (i.e. spermatozoa potentially involved in natural conception) from patients and controls using TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay coupled with flow cytometry. SDF median values were compared between groups: (i) HL and NHL patients versus controls at the three time points; (ii) HL versus NHL patients at baseline; and (iii) patients at T0 versus T2 and T3. Severe DNA damage (SDD) was defined for SDF levels above the 95th percentile of controls (50%) and the proportion of patients with SDD at all time points was established.

MAIN RESULTS AND THE ROLE OF CHANCE

At T0, patients displayed higher median SDF than controls, reaching statistical significance in the NHL group: 40.5% [IQR: 31.3-52.6%] versus 28% [IQR: 22-38%], P < 0.05. Comparing SDF pre-treatment to that post-treatment, HL patients exhibited similar median values at the three time points, whereas NHL showed significantly lower values at T3 compared to T0: 29.2% [IQR: 22-38%] versus 40.5% [IQR: 31.3-52.6%], P < 0.05. The proportion with SDD in the entire cohort at T2 was 11.6% and 13.3% among HL and NHL patients, respectively. At T3, only one in 16 NHL patients presented SDD.

LIMITATIONS, REASONS FOR CAUTION

TUNEL assay requires at least 5 million spermatozoa to be performed; hence, severe oligozoospermic men were not included in the study. Although our cohort represents the largest one in the literature, the relatively small number of patients does not allow us to establish precisely the frequency of SDD at T2 which in our study reached 11-13% of patients.

WIDER IMPLICATIONS OF THE FINDINGS

Our data provide further insights into the long-term effects of cytotoxic treatments on the sperm genome. The persistent severe DNA damage after 2 years post-treatment observed in some patients suggests that there is an interindividual variation in restoring DNA integrity. We propose the use of SDF as a biomarker to monitor the treatment-induced genotoxic effects on sperm DNA in order to better personalize pre-conceptional counseling on whether to use fresh or cryopreserved spermatozoa.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from the Istituto Toscano Tumori (ITT), Fondazione Ente Cassa di Risparmio di Firenze, the European Commission-Reproductive Biology Early Research Training (REPROTRAIN). C.K., G.F., V.R., and A.R.-E. belong to COST Action CA20119 (ANDRONET) which is supported by the European Cooperation in Science and Technology (www.cost.eu). The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Improving Semen Quality in a Male Partner With Abnormal Seminal Parameters Through Yoga and Yoga Nidra: A Case Report

This research presents a case study involving a 39-year-old male and his 34-year-old female partner seeking fertility consultation in Maharashtra, India, after struggling to conceive for over three years. Despite the male participant's lack of discernible medical conditions and typical lifestyle, semen analysis revealed severe oligozoospermia attributed to elevated stress levels from his physically demanding occupation and infertility-related emotional strain. The female partner exhibited normal blood parameters, including anti-Müllerian hormone (AMH). Embracing holistic approaches, the couple integrated yoga and Yoga Nidra into their daily routine to address stress-induced hormonal imbalances. The customized yoga regimen is aimed at stress reduction and overall well-being, incorporating physical postures, breathing exercises, and meditation. Yoga Nidra, a guided relaxation technique, was employed to induce profound rest and alleviate stress. Over a 12-week period, the male participant diligently adhered to the regimen, reporting heightened relaxation, improved sleep quality, and reduced stress levels. Semen analysis before and after intervention showed significant improvements in sperm count and motility alongside diminished morphological abnormalities. In parallel, the female partner underwent intrauterine insemination (IUI), resulting in a positive beta-human chorionic gonadotropin (β-hCG) analysis. Weekly follow-ups monitored progress, with supplementation administered as needed. While promising, further research with larger sample sizes and controlled trials is warranted to establish definitive efficacy. Overall, yoga and Yoga Nidra offer noninvasive adjuncts to conventional therapies for male infertility, underscoring the importance of integrating holistic practices into comprehensive fertility management strategies.

External quality assessment scheme for sperm DNA fragmentation: a pilot study in China

BACKGROUND

The aim of this article is to establish an external quality assessment (EQA) scheme for sperm Deoxyribonucleic acid (DNA) fragmentation (SDF) detection, and to assess the feasibility of the scheme. In addition, this article provides some case analysis of abnormal results in order to really help improve the performance of the laboratory.

RESULTS

In 2021 and 2022, 10 and 28 laboratories in China volunteered to participate in the EQA program respectively. Two samples were selected for EQA each year, a large spread of results was obtained for the four samples, and the highest values were 13.7, 4.2, 8.0 and 4.0 times the lowest respectively. The coefficients of variation (CVs) were very high for the four samples, at 46.6%, 30.1%, 26.7% and 30.3%, respectively. The CVs of the samples with high SDF values were lower than those of the samples with low SDF values. There was no significant difference between the results of sperm chromatin structure assay (SCSA) and sperm chromatin dispersion (SCD). For the 10 laboratories that participated in EQA in 2021 and 2022, the CVs of low SDF value samples and high SDF value samples decreased from 46.6% and 30.1% in 2021 to 32.5% and 22.7% in 2022, respectively.

CONCLUSION

This is the first study to evaluate the EQA program on SDF, which involved a number of laboratories and was demonstrated to be feasible. It is recommended that all laboratories participate in the EQA of SDF to ensure the accuracy of the results.

Long-term effect of cytotoxic treatments on sperm DNA fragmentation in patients affected by testicular germ cell tumor

INTRODUCTION

Testicular germ cell tumor is the most frequent neoplasia in men of reproductive age, with a 5-year survival rate of 95%. Antineoplastic treatments induce sperm DNA fragmentation, especially within the first year post-therapy. Data in the literature are heterogeneous concerning longer follow-up periods, and the large majority is limited to 2 years.

OBJECTIVE

To define the timing for the recovery of sperm DNA damage and the proportion of patients with severe DNA damage at 2 and 3 years from the end of therapy.

MATERIALS AND METHODS

Sperm DNA fragmentation was evaluated in 115 testicular germ cell tumor patients using terminal deoxynucleotidyl transferase dUTP nick end labeling assay coupled with flow cytometry before (T0 ) and 2 (T2 ) and 3 (T3 ) years post-treatment. Patients were divided based on the type of treatment: carboplatin, bleomycin-etoposide-cisplatin, and radiotherapy. For 24 patients, paired sperm DNA fragmentation data were available at all time-points (T0 -T2 -T3 ). Seventy-nine cancer-free, fertile normozoospermic men served as controls. Severe DNA damage was defined as the 95th percentile in controls (sperm DNA fragmentation = 50%).

RESULTS

Comparing patients versus controls, we observed: (i) no differences at T0 and T3 and (ii) significantly higher sperm DNA fragmentation levels (p < 0.05) at T2 in all treatment groups. Comparing pre- and post-therapy in the 115 patients, the median sperm DNA fragmentation values were higher in all groups at T2 , reaching significance (p < 0.05) only in the carboplatin group. While the median sperm DNA fragmentation values were also higher in the strictly paired cohort at T2 , about 50% of patients returned to baseline. The proportion of severe DNA damage in the entire cohort was 23.4% and 4.8% of patients at T2 and T3 , respectively.

DISCUSSION

Currently, testicular germ cell tumor patients are advised to wait 2 years post-therapy before seeking natural pregnancy. Our results suggest that this period may not be sufficient for all patients.

CONCLUSION

The analysis of sperm DNA fragmentation may represent a useful biomarker for pre-conception counseling following cancer treatment.

Clinical parameters associated with altered sperm DNA fragmentation index among primary infertile men: Findings from a real-life cross-sectional study

BACKGROUND

Recurrent pregnancy loss and unexplained infertility are the current indications to test sperm DNA fragmentation according to the European Association of Urology Guidelines on sexual and reproductive health.

OBJECTIVE

To identify a novel and better performing model to diagnose primary infertile men presenting with altered sperm DNA fragmentation and to outline its predictive ability in respect to current European Association of Urology Guidelines' recommendations.

MATERIALS AND METHODS

Data from the latest 515 consecutive primary infertile men as for World Health Organization criteria were analyzed. Semen analysis, sperm DNA fragmentation (according to sperm chromatin structure assay), and serum hormones were considered in every patient. Altered sperm DNA fragmentation was defined with levels greater than 30%. Descriptive statistics was applied to compare patients with normal versus SDF > 30%. The new predicting model was identified through logistic regression analysis exploring potential predictors of SDF > 30% at first clinical presentation. Diagnostic accuracy between the two predictive models (European Association of Urology Guidelines vs. new) was assessed, and decision curve analyses tested their clinical benefit.

RESULTS

Of 515, 268 (51.9%) patients had SDF > 30% at clinical presentation. Patients with SDF > 30% were older (median [interquartile range] 39 [35-43] vs. 37 [34-41] years), had lower mean testicular volume (Prader 15 [12-20] vs. 17.5 [13.5-20] and lower total motile sperm count (1.80 [0.7-13.2] vs. 11.82 [4.2-44.5] × 106 ), all p < 0.001. No other clinical differences were depicted. The two groups showed similar rates of history of recurrent pregnancy loss and unexplained infertility. At multivariable logistic regression analysis, age more than 38 years (odds ratio: 2.43) and baseline total motile sperm count less than 20 × 106 (odds ratio: 3.72) were associated with SDF > 30%, after adjusting for Prader < 15, history of miscarriages and unexplained infertility, all p < 0.0001. The newly identified model (unexplained infertility + history of poli-abortions + Prader < 15 + age ≥38 years + total motile sperm count <20 × 106 ) showed higher accuracy to identify SDF > 30% at baseline in respect to European Association of Urology Guidelines (area under the curve: 72.1 vs. 52.7), with superior clinical net benefit use.

CONCLUSIONS

The application of the European Association of Urology sexual and reproductive health guidelines does not ensure proper identification of primary infertile men with pathological sperm DNA fragmentation. We propose a novel and better performing predictive model to identify the infertile men with altered sperm DNA fragmentation at first clinical assessment.

DISCUSSION

As altered sperm DNA fragmentation has been widely linked with the inability to conceive, this second-level test could be further implemented over the diagnostic workup of a broader subset of patients presenting for male factor infertility. We propose a better performing model to identify this specific category of patients.

Can semen parameters predict pregnancy outcomes?

Semen analysis is an integral component of the evaluation and management of men with infertility. Although it is important for patient counseling and clinical decision making, a conventional semen analysis cannot reliably predict the chance of pregnancy or differentiate fertile vs. infertile men (except in the most extreme cases). Advanced, nonstandard sperm functional tests may provide additional discriminatory and prognostic power; however, further research is needed to determine how to best incorporate these tests into modern clinical practice. Therefore, the primary applications of a conventional semen analysis should be to judge the severity of infertility, estimate the effects of future therapy, and measure the response to current therapy.

Trend of change of sperm count and concentration over the last two decades: A systematic review and meta-regression analysis

BACKGROUND

Since the 1970s, several studies found that sperm concentration (SC) and total sperm count (TSC) constantly worsened over time, mainly in high-income countries.

OBJECTIVES

To evaluate whether the decreasing trend in sperm count is continuing in Western European countries and USA, we performed a systematic review and meta-regression analysis.

MATERIALS AND METHODS

Embase and Pubmed/Medline were searched papers published in English in the 2000-2020 period limiting the search to data collected in the USA and Western European countries.

RESULTS

We identified 62 articles and pooled information on 24,196 men (range 10-2,523), collected from 1993 to 2018. Considering all the studies, random-effects meta-regression analyses showed no significant trend for SC (slope per year -0.07 mil/mL, p-value = 0.86). Negative trends of SC were detected in Scandinavian countries (slope per year -1.11 mil/mL, 95% CI: -2.40 to +0.19; p-value = 0.09), but the findings were statistically not significant. No significant trends of SC were detected in Central Europe (slope per year +0.23, 95% CI -2.51 to +2.96; p-value = 0.87), the USA (slope per year +1.08, 95% CI -0.42 to +2.57; p-value = 0.16), and Southern Europe (slope per year +0.19, 95% CI -0.99 to +1.37; p-value = 0.75). We have analyzed separately findings from studies including sperm donors, fertile men, young unselected men (unselected men, study mean age < 25 years) and unselected men (unselected men, study mean age ≥ 25 years). No significant trends of SC were observed among sperm donors (slope per year -2.80, 95% CI -6.76 to +1.17; p-value 0.16), unselected men (slope per year -0.23, 95% CI -1.58 to +1.12; p-value 0.73), young unselected men (slope per year -0.49, 95% CI -1.76 to +0.79; p-value 0.45), fertile men (slope per year +0.29, 95% CI -1.09 to +1.67; p-value 0.68).

DISCUSSION AND CONCLUSION

The results of this analysis show no significant trends in SC, in USA, and selected Western European countries.

Decrease of air pollution during lockdown in Tuscany (Italy): An effect on sperm DNA fragmentation?

In March 2020, the Italian government imposed a national lockdown which was almost completely removed in June 2020. Due to the abrupt stop of human activities, emissions of air pollutants decreased. Air pollution is an environmental risk factor for noncommunicable disease and mortality. Emerging evidence also suggests a role in male infertility. In this study, we compared sperm DNA fragmentation (sDF) levels and conventional semen parameters between subjects undergoing sDF determination and routine semen analysis in a single Italian centre, during about 6 months before (N = 119) and after lockdown (N = 105). After lockdown, we found an improvement of sperm progressive motility (48.00[38.50-58.00]% vs. 42.00[33.00-53.00]%) and sDF levels (as total: 24.79[18.33-33.97]% vs. 35.02[25.04-45.73]%, p < .001; brighter: 14.02[10.69-17.93]% vs 18.54[13.58-25.82]%, p < .001 and dimmer sDF: 9.24[5.64-15.78]% vs. 12.24[8.08-19.10]%, p < .01), mirrored by a decrease of leukocyte semen concentration (p < .01). The improvement of sperm motility and DNA quality was maintained after adjusting for leukocyte concentration and several conditions known to affect sperm motility and/or sDF levels. With a significant decrease in air pollution observed in Tuscany during and after lockdown, associated improvement in sperm motility and DNA quality in patients referred to the infertility clinic is suggestive of the potential role of air pollution in male infertility.

Altered DNA methylation in estrogen-responsive repetitive sequences of spermatozoa of infertile men with shortened anogenital distance

BACKGROUND

It has been suggested that antenatal exposure to environmental endocrine disruptors is responsible for adverse trends in male reproductive health, including male infertility, impaired semen quality, cryptorchidism and testicular cancer, a condition known as testicular dysgenesis syndrome. Anogenital distance (AGD) is an anthropomorphic measure of antenatal exposure to endocrine disruptors, with higher exposure levels leading to shortened AGD. We hypothesized that exposure to endocrine disruptors could lead to changes in DNA methylation during early embryonic development, which could then persist in the sperm of infertile men with shortened AGD.

RESULTS

Using fluorescence activated cell sorting based on staining with either YO-PRO-1 (YOPRO) or chromomycin-3 (CMA3), we isolated four sperm fractions from eleven infertile men with short AGD and ten healthy semen donors. We examined DNA methylation in these sorted spermatozoa using reduced representation bisulfite sequencing. We found that fractions of spermatozoa from infertile men stained with CMA3 or YOPRO were more likely to contain transposable elements harboring an estrogen receptor response element (ERE). Abnormal sperm (as judged by high CMA3 or YOPRO staining) from infertile men shows substantial hypomethylation in estrogenic Alu sequences. Conversely, normal sperm fractions (as judged by low CMA3 or YO-PRO-1 staining) of either healthy donors or infertile patients were more likely to contain hypermethylated Alu sequences with ERE.

CONCLUSIONS

Shortened AGD, as related to previous exposure to endocrine disruptors, and male infertility are accompanied by increased presence of hormonal response elements in the differentially methylated regulatory sequences of the genome of sperm fractions characterized by chromatin decondensation and apoptosis.

Variability in Sperm DNA Fragmentation in Men with Mild/Unexplained Subfertility in a Prospective Longitudinal Intrauterine Insemination Trial

The biological variability of semen and sperm DNA fragmentation (SDF) parameters in a longitudinal intrauterine insemination (IUI) trial over multiple IUI cycles was investigated. A TUNEL assay was used for SDF testing, both before and after density gradient centrifugation. A significant age effect was observed: while semen parameters deteriorated with advancing age, on average, higher SDF values were observed for older males. There was quite some variability observed for both semen and SDF variables. Using fertile threshold values, three patient categories were distinguished: those with a high SDF in all samples, those with low SDF in all samples and those who fluctuated between high and low during the whole IUI trial. Density gradient centrifugation increases SDF. However, the three patient categories react differently after semen processing. A large percentage of those with high SDF retain their high SDF even after gradient centrifugation. The SDF fluctuaters react with a high SDF after gradient centrifugation. The low SDF category, on the contrary, distributes itself evenly between the three categories after gradient centrifugation. SDF testing after semen processing might be indispensable for therapeutic purposes, probably influencing medical decision-making. In order to isolate fluctuaters, a second SDF testing might be advocated in certain cases. SDF after semen processing is indispensable for therapeutic management.

Risk factors on testicular function in adolescents

PURPOSE

Adolescence represents an important window for gonadal development. The aim of this review is to carry out a critical excursus of the most recent literature on endogenous and exogenous risk factors related to testicular function, focusing the research on adolescence period.

METHODS

A comprehensive literature search within PubMed was performed to provide a summary of currently available evidence regarding the impact on adolescence of varicocele, cryptorchidism, cancer, diabetes, lifestyle factors, endocrine disruptors, obesity and sexually transmitted diseases. We focused on human studies that evaluated a possible impact of these factors on puberty timing and their effects on andrological health.

RESULTS

Evidence collected seems to suggest that andrological health in adolescence may be impaired by several factors, as varicocele, cryptorchidism, and childhood cancer. Despite an early diagnosis and treatment, many adolescents might still have symptoms and sign of a testicular dysfunction in their adult life and at the current time it is not possible to predict which of them will experience andrological problems. Lifestyle factors might have a role in these discrepancies. Most studies point out towards a correlation between obesity, insulin resistance, alcohol, smoking, use of illegal drugs and testicular function in pubertal boys. Also, endocrine disruptors and sexually transmitted diseases might contribute to impair reproductive health, but more studies in adolescents are needed.

CONCLUSION

According to currently available evidence, there is an emerging global adverse trend of high-risk and unhealthy behaviors in male adolescents. A significant proportion of young men with unsuspected and undiagnosed andrological disorders engage in behaviors that could impair testicular development and function, with an increased risk for later male infertility and/or hypogonadism during the adult life. Therefore, adolescence should be considered a key time for intervention and prevention of later andrological diseases.

A systematic review identifying fertility biomarkers in semen: a clinical approach through Omics to diagnose male infertility

OBJECTIVE

To identify the most robust molecular biomarkers in sperm and seminal plasma for the diagnosis of male infertility, and to evaluate their clinical use.

DESIGN

Systematic review.

SETTING

Not applicable.

PATIENT(S)

Accessible studies reporting well-defined (in)fertile populations and semen molecular biomarkers were included in this review.

INTERVENTION(S)

A systematic search of the literature published in MEDLINE-PubMed and EMBASE databases was performed, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

MAIN OUTCOME MEASURE(S)

The primary outcome was the content, expression, or activity of molecular biomarkers in human semen samples. Only studies reporting a receiver-operating characteristic (ROC) analysis values were included.

RESULT(S)

Eighty-nine studies were included. Direct evaluation of sperm DNA damage has high potential as a diagnostic biomarker of fertility and assisted reproductive technology outcomes (area under the curve [AUCs] median = 0.67). Regarding strand break-associated chromatin modifications, γH2AX levels show good predictive value for the diagnosis of male infertility (AUCs median = 0.93). Some noncoding ribonucleic acid (RNA) exhibit excellent predictive values; miR-34c-5p in semen is the most well-characterized and robust transcriptomic biomarker (AUCs median = 0.78). While many proteins in semen show fair diagnostic value for sperm quality and fertilizing capacity, the levels of some, such as TEX101, in seminal plasma have an excellent diagnostic potential (AUCs median = 0.69). Although individual metabolites and metabolomic profiles in seminal plasma present good predictive value, the latter seem to be better than the former when inferring sperm quality and fertilizing capacity.

CONCLUSION(S)

The current review supports that some Omics (e.g., DNA structure and integrity, genomics and epigenomics, transcriptomics, metabolomics, and proteomics) could be considered relevant molecular biomarkers that may help identify infertility etiologies and fertilization prognosis with cost-effective, simple, and accurate diagnosis.

Evolution of the World Health Organization semen analysis manual: where are we?

The WHO (World Health Organization) manuals provide state-of-the-art guidance on how a semen analysis should be carried out. The much anticipated sixth edition of the WHO semen analysis manual has been released 10 years after its previous version and includes essential updates, such as new reference standards for semen volume and microscopic sperm characteristics of recent fathers. A well-conducted semen analysis remains an essential foundation of the infertility evaluation process and affects patient referral, diagnosis and treatment. However, a male infertility work-up primarily based on routine semen analysis does not provide men with an optimal fertility pathway; the primary reasons for routine semen analysis inadequacy in this context include its low predictive value for natural and assisted conception success, its inability to detect sperm DNA and epigenetic deficiencies that might negatively affect embryo development, implantation and offspring well-being, and the substantial overlap between semen parameters of fertile and subfertile individuals. Ideally, a full andrological assessment should be carried out by reproductive urologists in all men dealing with couple infertility and should include a detailed history analysis, physical examination, semen analysis, endocrine assessment and other tests as needed. Only through a complete male infertility work-up will relevant underlying medical and infertility conditions be revealed and potentially treated or alleviated. The ultimate goals of a comprehensive andrological assessment are to positively influence overall male health, pregnancy prospects and offspring well-being.

Extended semen examinations in the sixth edition of the World Health Organization manual on semen analysis: contributing to the understanding of the function of the male reproductive system

In the sixth edition of the World Health Organization manual for the examination and processing of human semen, extended examination methods to provide key diagnostics in the investigation of the male reproductive system function are elaborated. These go beyond the basic analysis of semen and may be useful in more specifically guiding the clinical characterization of fertile or infertile men. Among the extended examinations included in the chapter, the use of multiparametric scoring for sperm morphological defects, sperm DNA fragmentation, and the roles for computer-assisted analysis of sperm or semen are arguably those that will be the most widely used and may also cause the most debate.

Sperm DNA fragmentation in reproductive medicine: A review

Approximately 15% of the world's couples suffer from infertility during their reproductive period of which the male factor is responsible for 50% of cases. Male factor infertility is multifactorial in origin, and sperm DNA fragmentation (SDF) has also been linked to male infertility including idiopathic male infertility. Some degree of controlled DNA nicking is essential for adequate DNA compaction, but excessive SDF is usually associated with reduced male fertility potential, reduced fertilisation, poor embryo quality, recurrent pregnancy loss and poor assisted reproductive techniques (ARTs) outcomes. Although semen analysis remains the gold standard for diagnosis of male factor infertility worldwide, its limitations motivated the search and the development of complementary tests of sperm function and integrity. SDF assay is an emerging diagnostic tool in infertile men, and several indications for SDF testing in infertile couples have also been proposed. The use of SDF in routine male infertility assessment is, however, still controversial. Furthermore, both direct and indirect SDF tests are now available. Hence, the present review was conducted to summarise the recent evidence of SDF, underlying mechanisms, clinical indications, diagnostic tests, as well as the role of SDF in male factor infertility, pregnancy and ART outcomes.

The TUNEL assay underestimates the incidence of DNA damage in pig sperm due to chromatin condensation

Inconsistencies in the relationship between sperm DNA fragmentation and reproductive outcomes as well as the low incidence in farm animals raise concerns on its actual value as a sperm quality parameter. Previous studies suggested that the different sensitivity of techniques evaluating DNA fragmentation could explain variations in the correlation with reproductive outcomes. While the TUNEL assay is one of the most standardized methods to detect DNA damage and cell death, the steric impediment for the terminal nucleotidyl transferase enzyme to access the highly condensed sperm nucleus may decrease the ability of this test to detect internal DNA breaks. In the present study, we sought to determine whether increasing chromatin decondensation makes the TUNEL assay more sensitive to detect DNA damage in pig sperm. We compared three chromatin decondensation treatments (2 mM DTT for 45 min; 5 mM DTT for 8 min and further 45 min; and 5 mM DTT+ 1 M NaCl for 8 min) through the Chromomycin A3 test (CMA3). While incubation with DTT increased the percentages of sperm with decondensed chromatin, regardless of concentration and time of incubation (P < 0.05), the extent of that decondensation was higher when 5 mM DTT was combined with 1 M NaCl. In addition, the TUNEL assay detected a higher number of DNA breaks in sperm with decondensed chromatin (1.89% ± 1.63% vs 8.74% ± 6.05%; P = 0.003). This study shows, for the first time, that previous chromatin decondensation increases the sensitivity of the TUNEL assay to detect DNA damage in pig sperm. These findings also support that larger chromatin decondensation is needed in order for DNA damage to be evaluated properly in species containing protamine P1 only.

Effects of lead, cadmium, copper and zinc levels on the male reproductive function

This study aimed to investigate the effects of heavy metals on measures of male fertility. One hundred and two infertile men with occupational exposure and thirty fertile men were included in this study. Blood and urinary levels of lead, cadmium, zinc and copper were measured by atomic absorption spectrophotometry. Semen parameters and a motile sperm organelle morphology examination were also performed. Measures of hormonal levels, oxidation-reduction potential, DNA fragmentation index and chromatin condensation were assessed for all participants. Heavy metals levels, oxidative stress and DNA quality were significantly higher in the infertile group compared to controls. FSH and testosterone levels were lower in the infertile group. A urinary cadmium level was positively associated with abnormal sperm morphology (r = .225, p < .05). Normal morphology was inversely correlated with the duration of the exposure (r = -.227, p = .022). The blood lead level was positively related to the level of testosterone (r = .223, p = .031). Cadmium and lead blood levels were positively correlated with the level of chromatin decondensation (r = .528, p < .001; r = .280, p = .017). Our study showed that occupational exposure to heavy metals is very harmful to reproductive health. DNA quality and oxidative stress investigations must be recommended for reprotoxic exposed patients prior to in vitro fertilisation treatment.

TUNEL assay-Standardized method for testing sperm DNA fragmentation

Sperm DNA integrity is important for normal functions such as fertilization, implantation, pregnancy and fetal development. Sperm DNA fragmentation (SDF) is more common in infertile men and may be responsible for poor reproductive function. Although there are a number of tests available to measure SDF, the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling TUNEL) assay using flow cytometry is becoming more popular to measure the sperm DNA fragmentation. It is a direct test that measures both single- and double- DNA strand breaks. In this review, we describe the protocol, quality control and measurement of sperm DNA fragmentation using a benchtop flow cytometer. We also briefly discuss the factors that can affect the results, challenges and clinical implications of TUNEL in assessing male infertility.

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

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.

Differential microRNAs expression in seminal plasma of normospermic patients with different sperm DNA fragmentation indexes

Sperm DNA fragmentation index (SDF), as an important supplement to routine semen parameters, has been proposed to discriminate between fertile and infertile men, and predicts the outcomes of natural conception and in vitro fertilization. Unfortunately there are uncertainty and contradictory evidences regarding the importance of SDF. An important reason is the fact that significant and fundamental research about SDF is rare. This study was designed to characterize the microRNA (miRNA) expression profile in seminal plasma of normospermic patients with different SDF and their implications in human fertility. Using next-generation sequencing (NGS), a total of 897 human miRNAs were detected from 10 seminal plasma samples, out of which 431 differentially expressed miRNAs in 5 pairs of seminal plasma samples (each pair of seminal plasma samples obtained from the same male), with 14 miRNAs were identified in all the pairs. According to the fold change and expression level, 7 miRNAs including miR-374b-5p, miR-429, hsa-miR-26b-5p, miR-21-5p, miR-4257, miR-135b-5p and miR-134-5p were selected for further excavation. MiR-374b-5p and miR-26b-5p were significantly different in 3 sets of individual seminal plasma samples with different SDF from total 90 infertile patients (30 patients each set). Our results demonstrate that the profile of miR-374b and miR-26b with significantly decreased expression could be used as a first indication of increased SDF. And miR-374b and miR-26b could serve as adjunct biomarkers for the diagnosis of idiopathic infertile males.

Tracking research trends and hotspots in sperm DNA fragmentation testing for the evaluation of male infertility: a scientometric analysis

BACKGROUND

This article describes the research trends in sperm DNA fragmentation (SDF) over the past 20 years (1999-2018) using a scientometric approach.

METHODS

A stepwise approach was adopted to retrieve scientometric data (articles per year, authors, affiliations, journals, countries) from Scopus and analyze the publication pattern of SDF with reference to key areas of research in the field of Andrology.

RESULTS

A total of 2121 articles were retrieved related to SDF. Our data revealed an increasing research trend in SDF (n = 33 to n = 173) over the past 20 years (R² = 0.894). Most productive country in publications was the USA (n = 450), while Agarwal A. (n = 129) being the most productive author. Most of the articles in SDF were primarily focused on lifestyle (n = 157), asthenozoospermia (n = 135) and varicocele (130). Mechanistic studies on SDF were published twice as much as prognostic/diagnostic studies, with significant emphasis on oxidative stress. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was the most widely used technique to evaluate SDF. Publications on SDF related to assisted reproductive techniques also showed a linear increasing trend (R² = 0.933).

CONCLUSIONS

Our analysis revealed an increasing trend in SDF publications predominantly investigating lifestyle, asthenozoospermia and varicocele conditions with TUNEL being the most widely used technique. A substantial increase in research is warranted to establish SDF as prognostic/diagnostic parameter to evaluate clinical scenarios and ART outcomes.

The current status and future of andrology: A consensus report from the Cairo workshop group

BACKGROUND

In attempting to formulate potential WHO guidelines for the diagnosis of male infertility, the Evidence Synthesis Group noted a paucity of high-quality data on which to base key recommendations. As a result, a number of authors suggested that key areas of research/evidence gaps should be identified, so that appropriate funding and policy actions could be undertaken to help address key questions.

OBJECTIVES

The overall objective of this Consensus workshop was to clarify current knowledge and deficits in clinical laboratory andrology, so that clear paths for future development could be navigated.

MATERIALS AND METHODS

Following a detailed literature review, each author, prior to the face-to-face meeting, prepared a summary of their topic and submitted a PowerPoint presentation. The topics covered were (a) Diagnostic testing in male fertility and infertility, (b) Male fertility/infertility in the modern world, (c) Clinical management of male infertility, and (d) The overuse of ICSI. At the meeting in Cairo on February 18, 2019, the evidence was presented and discussed and a series of consensus points agreed.

RESULTS

The paper presents a background and summary of the evidence relating to these four topics and addresses key points of significance. Following discussion of the evidence, a total of 36 consensus points were agreed.

DISCUSSION

The Discussion section presents areas where there was further debate and key areas that were highlighted during the day.

CONCLUSION

The consensus points provide clear statements of evidence gaps and/or potential future research areas/topics. Appropriate funding streams addressing these can be prioritized and consequently, in the short and medium term, answers provided. By using this strategic approach, andrology can make the rapid progress necessary to address key scientific, clinical, and societal challenges that face our discipline now and in the near future.

Removal of DNA-fragmented spermatozoa using flow cytometry and sorting does not improve the outcome of intracytoplasmic sperm injection

PURPOSE

The DNA fragmentation in sperm is associated with reduced outcome in assisted reproduction. Using YoPro1 as the staining dye and flow cytometry and sorting (FACS), the number of spermatozoa with DNA fragmentation can be lowered to 5%. Can the cumulative outcome of ICSI be improved using FACS?

METHODS

A prospective, randomized, double-blind clinical trial was conducted in 104 infertile couples with male infertility based on abnormal conventional semen analysis results. Cumulative ongoing pregnancy rate was the primary outcome parameter. In 52 cases, semen was processed for ICSI using swim-up. In another 52 cases, spermatozoa with fragmented DNA were removed with FACS.

RESULTS

The cumulative pregnancy rate at 12 weeks of gestation (51.9% versus 46.2%) and live birth rate (42.3% versus 34.6%) were higher and the miscarriage rate was lower (27.8% versus 35.3%) after FACS-sorting as compared with swim-up. An interim analysis scheduled before initiation of the study after 100 cases demonstrated that the aim of a 20% gain in pregnancy rate could not be achieved. For that reason, the prospective study was stopped prematurely.

CONCLUSIONS

A trend towards consistently better results was achieved by removing spermatozoa with fragmented DNA. The fragmentation of the DNA in sperm is the end stage of apoptosis. Sorting of spermatozoa may be improved by selecting parameters of processes active more upstream of apoptosis, such as chromatin decondensation.

TRIAL REGISTRATION

NCT02166567 . June 14, 2014.

Genetics of male infertility

Male infertility is a multifactorial pathological condition affecting approximately 7% of the male population. The genetic landscape of male infertility is highly complex as semen and testis histological phenotypes are extremely heterogeneous, and at least 2,000 genes are involved in spermatogenesis. The highest frequency of known genetic factors contributing to male infertility (25%) is in azoospermia, but the number of identified genetic anomalies in other semen and aetiological categories is constantly growing. Genetic screening is relevant for its diagnostic value, clinical decision making, and appropriate genetic counselling. Anomalies in sex chromosomes have major roles in severe spermatogenic impairment. Autosome-linked gene mutations are mainly involved in central hypogonadism, monomorphic teratozoospermia or asthenozoospermia, congenital obstructive azoospermia, and familial cases of quantitative spermatogenic disturbances. Results from whole-genome association studies suggest a marginal role for common variants as causative factors; however, some of these variants can be important for pharmacogenetic purposes. Results of studies on copy number variations (CNVs) demonstrate a considerably higher CNV load in infertile patients than in normozoospermic men, whereas whole-exome analysis has proved to be a highly successful diagnostic tool in familial cases of male infertility. Despite such efforts, the aetiology of infertility remains unknown in about 40% of patients, and the discovery of novel genetic factors in idiopathic infertility is a major challenge for the field of androgenetics. Large, international, and consortium-based whole-exome and whole-genome studies are the most promising approach for the discovery of the missing genetic aetiology of idiopathic male infertility.

Characterization of fertility associated sperm proteins in Aseel and Rhode Island Red chicken breeds

This study focused on characterization of fertility associated proteins in Aseel and RIR roosters and was conducted on two generations of birds. Roosters were divided into high (>50%) and low fertility groups (<50%) based on sperm function tests and fertility rate in both the generations. Polyclonal antibodies were raised in rabbits against sperm proteins of first generation highly fertile roosters and tested for characterization of fertility associated sperm proteins in the second generation of same roosters. IgG-fraction against proteins (Anti-SP-IgG) was reacted with sperm proteins of both high and low fertile roosters of second generation on immunoblots. Sperm proteins present in highly fertile roosters were further characterized by Mass Spectrometry (MS). Use of SDS-PAGE for evaluation of sperm extracts of Aseel and RIR breeds resulted in resolution of 16 and 10 proteins on 12% acrylamide gels. Anti-SP-IgG reacted with eight and ten sperm proteins of Aseel and RIR roosters on immunoblots. The SDS-PAGE and immunoblotting analysis also indicated a variation in sperm proteins among two breeds and high/low fertile roosters. The MS analysis indicated matching of 20, 30, and 20, 25 kDa proteins (associated with high fertility rate) of Aseel and RIR roosters with immunoglobulin kappa chain variable, phospholipase A₂ (PLA2), hypothetical N332-08551 partial and cystatin like partial proteins with a top score of 41, 46, 52 and 43, respectively. Considering the function and importance of matching proteins in male reproduction, these proteins may be further explored as potential markers for fertility evaluation of Aseel and RIR roosters.

Chromatin condensation, fragmentation of DNA and differences in the epigenetic signature of infertile men

Epidemiological studies report an increase of pathologies of male reproductive tracts and suggest a link between this trend and the increased exposure of men to endocrine disruptors (EDs). The mechanisms by which EDs impact male fertility are far to be elucidated although DNA, chromatin and epigenome of spermatozoa appear to be relevant targets for these molecules. Indeed, many studies report associations between increased levels of sperm DNA fragmentation (sDF) or aberrant chromatin condensation or epigenetic modifications and poor semen quality and/or infertile phenotype. In this scenario, therapies able to reduce sperm damage to DNA, chromatin and epigenome are sought. Currently, antioxidants and FSH administration is proposed for treating high levels of sDF, but whether or not such therapies are really effective is still debated. Further studies are necessary to understand the link between endocrine disruptor exposure and damage to sperm function and/or structure and thus to define effective therapeutic strategies.

Pharmacogenetics of FSH Action in the Male

Male infertility is a major contributor to couple infertility, however in most cases it remains "idiopathic" and putative treatment regimens are lacking. This leads to a scenario in which intra-cytoplasmic spermatozoa injection (ICSI) is widely used in idiopathic male infertility, though the treatment burden is high for the couple and it entails considerable costs and risks. Given the crucial role of the Follicle-stimulating hormone (FSH) for spermatogenesis, FSH has been used empirically to improve semen parameters, but the response to FSH varied strongly among treated infertile men. Single nucleotide polymorphisms (SNPs) within FSH ligand/receptor genes (FSHB/FSHR), significantly influencing reproductive parameters in men, represent promising candidates to serve as pharmacogenetic markers to improve prediction of response to FSH. Consequently, several FSH-based pharmacogenetic studies have been conducted within the last years with unfortunately wide divergence concerning selection criteria, treatment and primary endpoints. In this review we therefore outline the current knowledge on single nucleotide polymorphisms (SNPs) in the FSH and FSH receptor genes and their putative functional effects. We compile and critically assess the previously performed pharmacogenetic studies in the male and propose a putative strategy that might allow identifying patients who could benefit from FSH treatment.

Lifestyle and fertility: the influence of stress and quality of life on male fertility

BACKGROUND

Male infertility is a widespread condition among couples. In about 50% of cases, couple infertility is attributable to the male partner, mainly due to a failure in spermatogenesis. In recent times, the crucial role that modifiable lifestyle factors play in the development of infertility have generated a growing interest in this field of study, i.e. aging, psychological stress, nutrition, physical activity, caffeine, high scrotal temperature, hot water, mobile telephone use. Several studies have investigated associations between semen quality and the presence of lifestyle stressors i.e. occupational, life events (war, earthquake, etc.) or couple infertility; overall, these studies provide evidence that semen quality is impaired by psychological stress. In this review, we will discuss the impact of quality of life (modifiable lifestyle factors) and psychological stress on male fertility. In addition, the role that increased scrotal temperature along with inappropriate nutritional and physical exercise attitudes exert on male fertility will be presented.

CONCLUSION

The decline of male fertility, particularly associated with advancing age, incorrect lifestyles and environmental factors plays an important role on natality, and its consequences on the future on human population makes this an important public health issue in this century. Thus, modification of lifestyle through a structured program of educational, environmental, nutritional/physical exercise and psychological support, combined with the use of nutraceutical antioxidants can prevent infertility and therefore, may help couples to obtain better quality of life and improved possibility to conceive spontaneously or optimize their chances of conception.

Massive Weight Loss Obtained by Bariatric Surgery Affects Semen Quality in Morbid Male Obesity: a Preliminary Prospective Double-Armed Study

OBJECTIVES

The aim of this study is to evaluate the effect of massive weight loss on the seminal parameters at 6 months from bariatric surgery.

DESIGN

Two-armed prospective study performed in 31 morbidly obese men, undergoing laparoscopic roux-en-Y-gastric bypass (n = 23) or non-operated (n = 8), assessing sex hormones, conventional (sperm motility, morphology, number, semen volume), and non-conventional (DNA fragmentation and seminal interleukin-8), semen parameters, at baseline and after 6 months from surgery or patients' recruitment.

RESULTS

In operated patients only, a statistically significant improvement in the sex hormones was confirmed. Similarly, a positive trend in the progressive/total sperm motility and number was observed, though only the increase in semen volume and viability was statistically significant (Δ = 0.6 ml and 10%, P < 0.05, respectively). A decrease in the seminal interleukin-8 levels and in the sperm DNA fragmentation was also present after bariatric surgery, whereas these parameters even increased in non-operated subjects. Age-adjusted multivariate analysis showed that the BMI variations significantly correlated with the changes in the sperm morphology (β = -0.675, P = 0.025), sperm number (β = 0.891, P = 0.000), and semen volume (r = 0.618, P = 0.015).

CONCLUSION

The massive weight loss obtained with bariatric surgery was associated with an improvement in some semen parameters. The correlations found between weight loss and semen parameter variations after surgery suggest that these might occur early downstream of the testis and more slowly than the changes in the sex hormones.

DNA fragmentation in two cytometric sperm populations: relationship with clinical and ultrasound characteristics of the male genital tract

We investigated whether DNA fragmentation in two cytometric sperm populations (PIdimmer and PIbrighter) with different biological characteristics and clinical relevance is related to clinical and color-Doppler ultrasound (CDUS) parameters of the male genital tract. One hundred and sixty males of infertile couples without genetic abnormalities were evaluated for clinical, scrotal, and transrectal CDUS characteristics, presence of prostatitis-like symptoms (with the National Institutes of Health-Chronic Prostatitis Symptom Index) and sperm DNA fragmentation (sDF) in PIdimmer and PIbrighter populations (using TUNEL/PI method coupled with flow cytometry). Data were adjusted for age (Model 1) along with waistline, testosterone levels, smoking habit, and sexual abstinence (Model 2). According to the statistical Model 2, PIdimmer sDF was associated with testicular abnormalities, including lower clinical and ultrasound volume (r = -0.21 and r = -0.20, respectively; P < 0.05), higher FSH levels (r = 0.34, P < 0.0001) and occurrence of testicular inhomogeneity (P < 0.05) and hypoechogenicity (P < 0.05). PIbrighter sDF was associated with prostate-related symptoms and abnormal signs, including higher NIH-CPSI total and subdomain scores, a higher prevalence of prostatitis-like symptoms and of CDUS alterations such as macro-calcifications, severe echo-texture inhomogeneity, hyperemia (all P < 0.05), and higher arterial peak systolic velocity (r = 0.25, P < 0.05). Our results suggest that DNA fragmentation in PIdimmer sperm, which is related to poor semen quality, mainly originates in the testicles, likely due to apoptosis. Conversely, DNA fragmentation in PIbrighter sperm appears to mainly originate during or after transit through the prostate, increasing with the presence of an inflammatory status of the organ. These results could lead to new perspectives for the identification of therapeutic targets to reduce sDF.

Impact of a mild scrotal heating on sperm chromosomal abnormality, acrosin activity and seminal alpha-glucosidase in human fertile males

The aim of this study was to observe sperm aneuploidy, DNA integrity, seminal alpha-glucosidase (NAG) and acrosin activity (AA) under testicular heat stress (SH). Spermatozoa were obtained from 30 healthy adult volunteers subjected to scrotal warming at 43°C for 30-40 min on two successive days per week for 3 months between February 2012 and September 2016. Aniline blue (AB), acridine orange (AO) staining, TUNEL assay and FISH analysis to evaluate sperm function, sperm DNA integrity and chromosomal abnormalities were carried on before, during and after SH. Sperm AA and NAG was measured by microplate reader. The mean parameters of sperm parameters, AA and NAG were significantly decreased. In contrast, the mean percentage of sperm DNA fragmentation and the proportion of aneuploidy of chromosomes 13, 18, 21, X and Y were significantly increased for spermatozoa collected during SH versus before SH (p < .01-.001). After stopping scrotal heating for 3 months, most parameters were completely restored to pre-SH levels. Sperm parameters, sperm DNA integrity, chromosomes, AA and NAG are affected by scrotal exposure to constant SH temperatures several degrees over normal physiological temperature, and after treatment, these parameters were reversibly restored to the level before SH in adult men.

Effects of FSH on Sperm DNA Fragmentation: Review of Clinical Studies and Possible Mechanisms of Action

Sperm DNA fragmentation (sDF) is an important reproductive problem, associated to an increased time-to-pregnancy and a reduced success rate in natural and in vitro fertilization. sDF may virtually originate at any time of sperm's life: in the testis, in the epididymis, during transit in the ejaculatory ducts and even following ejaculation. Studies demonstrate that an apoptotic pathway, mainly occurring in the testis, and oxidative stress, likely acting in the male genital tract, are responsible for provoking the DNA strand breaks present in ejaculated spermatozoa. Although several pharmacological anti-oxidants tools have been used to reduce sDF, the efficacy of this type of therapies is questioned. Clearly, anti-apoptotic agents cannot be used because of the ubiquitous role of the apoptotic process in the body. A notable exception is represented by Follicle-stimulating hormone (FSH), which regulates testis development and function and has been demonstrated to exert anti-apoptotic actions on germ cells. Here, we review the existing clinical studies evaluating the effect of FSH administration on sDF and discuss the possible mechanisms through which the hormone may reduce sDF levels in infertile subjects. Although there is evidence for a beneficial effect of the hormone on sDF, further studies with clear and univocal patient inclusion criteria, including sDF cut-off levels and considering the use of a pharmacogenetic approach for patients selection are warranted to draw firm conclusions.

TUNEL labeling with BrdUTP/anti-BrdUTP greatly underestimates the level of sperm DNA fragmentation in semen evaluation

Many studies have now confirmed that sperm DNA fragmentation (SDF) is associated with a poorer outcome of some forms of assisted reproduction technology. For this reason, SDF is an important parameter to evaluate in male fertility assessment. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay coupled to flow cytometry is one of the most promising methods for SDF quantification. Several kits for the detection of DNA fragmentation are currently available on the market and all are recommended as equally appropriate to quantify SDF. In this work we compared for the first time the efficacy of two different types of TUNEL kits for SDF quantification: one using an indirect antibody-based labeling system (BrdUTP/fluorescein-anti-BrdUTP) and another using a direct labeling system (fluorescein-dUTP). We demonstrated that TUNEL indirect labeling system largely underestimates SDF when compared with the direct labeling, the differences ranging from 19.2% to 85.3% (p<0.05, n = 22). We observed that these differences were most pronounced among dead spermatozoa where indirect labeling stained 40.1% [23.6%, 58.2%] and the direct system 65.7% [36.5%, 90.9%] (n = 10, p<0.05). Interestingly, we found that both systems stained the living spermatozoa with the same efficiency. We showed that the differences are due to the steric hindrance of the antibody during its binding to the BrdUTP. Indeed, after sperm DNA decondensation, the percentages of TUNEL positivity increased significantly from 46.3% [31.8%, 61.7%] to 97.5% [96.1%, 98.8%] (p<0.05, n = 5). Our results are important for future use of TUNEL in clinical practice. Laboratories relying on the use of an antibody-based system heavily underestimate SDF, most particularly in infertile patients with reduced sperm motility. As a consequence, the kit using BrdUTP/fluorescein-anti-BrdUTP should not be recommended as a method to assay DNA damage in semen. This study represents one further step in the standardization of TUNEL among laboratories.

New insights in sperm biology: How benchside results in the search for molecular markers may help understand male infertility

The male factor is responsible for about 40% of couple infertility cases and such percentage is expected to increase in the future because of several likely factors including the presence of endocrine disruptors in the environment, changes in lifestyle habits and advanced couple aging. How such factors affect male fertility status, however, should be clarified. Most studies on male fertility status have focused on parameters analyzed using a spermiogram test, the primary diagnostic tool in the routine assessment of male infertility, which is, however, poorly predictive of both natural and medically assisted conception. For these reasons it is mandatory for the scientific community to identify new molecular markers to incorporate into the existing diagnostic tests of male fertility. Ideally, such markers would be detected in mature spermatozoa to avoid invasive procedures for the patient. This review summarizes the recent advancements in benchside approaches that appear most promising for the development of new diagnostic sperm fertility tests, or identification of therapeutic targets, and, illustrates their advantages and limits.