DNA fragmentation in spermatozoa: a historical review

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.

Relation between semen oxidative reduction potential in initial semen examination and IVF outcomes

Purpose

The MiOXSYS system is a new technique to analyze the semen oxidative reduction potential (ORP) that may use to classify the level of sperm DNA integrity. It does not clearly explain how the semen ORP values could help to change the IVF outcomes. We have analyzed correlations between semen ORP value and the IVF results.

Methods

Four hundred and thirty couples were enrolled. The male counterparts were divided into two groups according to their semen ORP values and compared the fertilization rate, cell cleavage rate, and embryo quality, following the IVF procedures. The relations between ORP values and the clinical pregnancy, live birth, and abortion rates were analyzed.

Results

The ORP values show negative and positive correlations with some conventional semen parameters. The fertilization and the cleavage rate did not show any differences in those two groups, but the transferable embryo rate was significantly high in patients with high semen ORP. However, the patients with high ORP show a tendency to lower clinical pregnancy with a low abortion rate compared to the low ORP group.

Conclusion

The main purpose of measuring the ORP value in semen is still questionable and shows controversial results.

A novel microfluidic device with parallel channels for sperm separation using spermatozoa intrinsic behaviors

Isolating high-quality motile sperm cells is considered to be the main prerequisite for a successful artificial pregnancy. Microfluidics has emerged as a promising platform capable of mimicking in-vivo environments to separate motile sperm cells and bypassing the need for the current invasive clinical sperm separation methods. In this study, the proposed microfluidic device exploits the parallelization concept through symmetry to increase both the processed sample volume and the injected flow rate compared with the previous conventional devices, which used rheotaxis as their primary method of sperm separation. Using the finite element method (FEM) and flow simulations, the trajectories of sperm cells exhibiting rheotaxis behavior were predicted inside the proposed device. Different flow rates, including 0, 0.5, 1.5, 3, 4.5 and 6 μl/min, were experimentally injected into the device, and the effect of flow rate on the size of the hypothetical rheotaxis zone and the number of isolated sperm cells was investigated. Furthermore, it was illustrated that 100% of the isolated motile sperm cells are motile, and by manipulating the injected flow rate into the device, different classes of sperm cells in terms of motility parameters can be separated and utilized for further uses.

Sperm DNA fragmentation testing in clinical management of reproductive medicine

Background

Approximately 8%-12% of couples worldwide face infertility, with infertility of individuals assigned male at birth (AMAB) contributing to at least 50% of cases. Conventional semen analysis commonly used to detect sperm abnormalities is insufficient, as 30% of AMAB patients experiencing infertility show normal results in this test. From a genetic perspective, the assessment of sperm DNA fragmentation (SDF) is important as a parameter of sperm quality.

Methods

In this narrative study, we review and discuss pathophysiological causes, DNA repair mechanisms, and management of high SDF. We then summarize literature exploring the association between SDF and reproductive outcomes.

Main Findings

Recent systematic reviews and meta-analyses have revealed a significant association between high SDF in AMAB individuals and adverse reproductive outcomes including embryo development, natural conception, intrauterine insemination, and in vitro fertilization. However, the association with live birth rates and pregnancy rates following intracytoplasmic injection remains inconclusive. The disparities among quantitative assays, inconsistent reference range values, absent high-quality prospective clinical trials, and clinical heterogeneity in AMAB patients with elevated SDF represent the main limitations affecting SDF testing.

Conclusion

The evaluation and management of SDF plays an important role in a subset of AMAB infertility, but widespread integration into clinical guidelines will require future high-quality clinical trials and assay standardization.

Expression of estrogen receptors, PELP1, and SRC in human spermatozoa and their associations with semen quality

Sperm cells are target cells for both estrogens and xenoestrogens. Due to the specific structure of spermatozoa, these hormonal compounds may act on sperm in a non-genomic mechanism only. However, the ESR-mediated signaling pathways are still poorly understood. In this study, we obtained 119 samples from male participants of Caucasian descent who donated semen for standard analysis. We analyzed gene expression of estrogen receptors (ESR1 and ESR2) and their coregulators-proline-, glutamic acid-, and leucine-rich protein 1 (PELP1), and cellular kinase c-Src (SRC). RNA level was established using reverse-transcribed RNA as a template, followed by a polymerase chain reaction. Proteins' presence was confirmed by western blot and immunocytochemistry techniques. "Normal" values of semen parameters were defined as follows: > 32% sperm with progressive motility, > 4% sperm cells with normal morphology, > 15 × 10⁶ sperm per mL, > 58% live spermatozoa and leukocyte amount < 10⁶ cells per mL, according to WHO 2010 reference. Semen parameters that deviated from these "normal" values were labeled as "abnormal". Gene expression ratios revealed significant, moderate, and negative correlations for ESR1/ESR2 and weak, negative ESR2/PELP1 correlations in the subgroup of patients with abnormal values of semen parameters. In addition, SRC/PELP1 was moderately and positively correlated in the subgroup with parameters within the reference values established by WHO 2010. Our study showed that both PELP1 scaffolding protein and SRC kinase might influence semen quality via ESRs. It seems that not the expression of a single gene may affect the sperm quality, but more gene-to-gene mutual ratio. Characterization of estrogen-signaling pathway-related genes' modulated expression in sperm cells could aid in better understanding sperm biology and quality.

Electrophysiology and Fluorescence Spectroscopy Approaches for Evaluating Gamete and Embryo Functionality in Animals and Humans

This review has examined two of the techniques most used by our research group for evaluating gamete and embryo functionality in animal species, ranging from marine invertebrates to humans. Electrophysiology has given access to fundamental information on some mechanisms underpinning the biology of reproduction. This technique demonstrates the involvement of ion channels in multiple physiological mechanisms, the achievement of homeostasis conditions, and the triggering of profound metabolic modifications, often functioning as amplification signals of cellular communication. Fluorescence spectrometry using fluorescent probes to mark specific cell structures allows detailed information to be obtained on the functional characteristics of the cell populations examined. The simple and rapid execution of this methodology allowed us to establish a panel helpful in elucidating functional features in living cells in a simultaneous and multi-parameter way in order to acquire overall drafting of gamete and embryo functionality.

Comparison of sperm preparation methods to improve the recovery of mature spermatozoa in sub-fertile males

The integrity of chromatin in the spermatozoon is essential for reproductive outcome. The aim of this study was to evaluate the most effective and cost-effective method to reduce the percentage of spermatozoa with defects in chromatin decondensation for use in assisted reproductive technologies (ART) procedures. Sperm samples from 15 sub-fertile males were examined at CFA Naples to determine the sperm decondensation index (SDI), using the aniline blue test, before and after preparation, comparing density gradients with two different swim-up approaches. All three techniques led to a reduction in decondensed spermatozoa with no statistical difference (P > 0.05) between the control and the treated sperm. In contrast, we found a highly significant decrease in SDI (P < 0.01) after the two swim-up methods in all the samples, confirming the efficacy of these methods in lowering the percentage of chromatin compaction damage. There was no statistical difference between the two swim-up methods, however swim-up from the pellet led to improved count, motility and the percentage of normal condensed spermatozoa. We suggest that swim-up from the pellet be used in ART on sub-fertile males, both to reduce cell stress by multiple centrifugation and improve the recovery rate of mature spermatozoa.

Low-dose Methotrexate Therapy Does Not Affect Semen Parameters and Sperm DNA

BACKGROUND

Methotrexate is widely used in inflammatory diseases during the patients' reproductive years. The effect on male fertility and sperm DNA integrity is largely unknown. We evaluated sperm DNA integrity and basic semen parameters according to the World Health Organization (WHO) in male patients with inflammatory diseases treated with methotrexate.

METHODS

Semen samples from 14 patients on low-dose maintenance methotrexate were compared with samples from 40 healthy volunteers. Further, 5 patients delivered samples on and off methotrexate therapy for paired comparison. Sperm DNA fragmentation index (DFI), concentration, motility, and morphology were evaluated. Blood sex hormones and methotrexate levels were measured in blood and semen.

RESULTS

DNA fragmentation index in methotrexate-treated patients was comparable with that in healthy volunteers (DFI, 11.5 vs 15.0; P = .06), and DFI did not change significantly on and off methotrexate in the paired samples (DFI, 12.0 vs 14.0; P = 0.35). Sperm concentration, motility, and morphology did not differ between men treated with methotrexate and healthy volunteers. Sperm progressive motility increased off therapy compared with on therapy (65.0% vs 45.0%, P = .04), but all fluctuations in progressive motility were within the WHO reference interval. All methotrexate polyglutamates1-5 were detected in blood, but only methotrexate polyglutamate1 in semen. Serum testosterone was unaffected by methotrexate therapy.

CONCLUSIONS

Patients treated with low-dose methotrexate have a sperm quality comparable with that of healthy volunteers, and methotrexate treatment does not increase sperm DNA fragmentation. This study does not support cryopreservation of semen before treatment initiation nor a 3-month methotrexate-free interval prior to conception.

Microfluidic chips as a method for sperm selection improve fertilization rate in couples with fertilization failure

PURPOSE

Sperm quality plays a vital role in successful fertilization and pregnancy. Patients with fertilization failure (total failure or low-fertilization rate) despite having normal semen parameters are a challenging group whose sperm cannot fertilize the oocyte via the intracytoplasmic sperm injection (ICSI) technique. Microfluidics is offered as a new method for proper sperm sorting.

METHODS

This study aimed to evaluate sperm parameters, DNA fragmentation index (DFI), expression of phospholipase C zeta 1 (PLCZ1), and transition nuclear proteins 1 (TNP1) mRNAs in sperm selected by microfluidic sperm sorting (MSS) chip compared with conventional density gradient centrifugation technique in patients with fertilization failure following ICSI. Subsequence fertilization rate and embryo quality were assayed.

RESULTS

Normal morphology and total motility were significantly higher, and DFI was significantly lower in sperm selected by the MSS chip in fertilization failure and control groups. The RT-PCR results demonstrated a significant increase in the expression of PLCZ1 and TNP1 genes in sperm of both groups selected by MSS chips compared to the DGC method. In addition, with the selected sperm by MSS chip, an increase in fertilization rate and improvement of embryo quality was obtained.

CONCLUSION

The present study findings show that sperm sorting by the microfluidic method improves fertilization rate in patients with poor fertilization outcomes following ICSI.

Sperm-oviduct interaction: Differential gene expression of growth factors induced by sperm DNA fragmentation

The present study investigated the effects of DNA fragmentation of spermatozoa on the growth factors expression by a human oviduct epithelial cell line (OE-E6/E7). Two separate groups were examined in this study. The cell line was cultured in the presence of spermatozoa with normal DNA fragmentation index (DFI) or abnormal DFI. Total RNA from the cell line in each group was isolated, and relative expression of objective genes was analysed using PCR array. Also, the concentration of VEGF, BMP-2, BMP-7 and MSTN in the supernatant of cell culture was analysed by the ELISA method. The PCR array analysis revealed that most of the growth factors had been upregulated in the abnormal group. However, the differences between groups were statistically significant (p < 0.05) for five genes, including VEGF-A, BMP-2, BMP-6, BMP-7 and OSM. Furthermore, MSTN was the only gene that down-regulated significantly under the influence of the spermatozoa with abnormal DFI. Moreover, the results of ELISA analysis were in agreement with the data of the PCR array. It has been concluded that DNA fragmentation in human spermatozoa can probably change regular events throughout the oviducts. Consequently, the genes of interest may change sperm function and probably its fate in the female reproductive tract.

Technical Evaluation of Commercial Sperm DFI Quality Control Products in SCSA Testing

With the increase in population and the advancement of medicine, people even more hope that their offspring will be healthier. DNA fragmentation rate is currently one of the more common indicators for evaluating sperm fertility and predicting the outcome of pregnancy. In order to evaluate the technical performance and application value of commercial sperm DFI (DNA fragmentation index) quality control products in the flow cytometry sperm chromatin structure analysis (SCSA), this paper uses flow cytometry to test commercial sperm DFI quality control products (Celula) and laboratory routine self-made DFI quality control products. In this paper, the quality control of new commercial sperm DFI and laboratory-made quality control were compared and tested for 30 consecutive days. And this paper monitors the response of commercial quality control products to the interference of key reagent parameters. This paper compares the stability of the test results of two quality control products and their sensitivity to the interference of key performance parameters of the detection reagent. Experimental results show that commercial sperm DFI quality control products can simulate sperm DNA damage to achieve accurate detection of DNA integrity. The stability of commercial sperm DFI quality control (CV = 2.47%) is better than that of laboratory-made quality control (CV = 11.22%). The new commercial sperm DFI quality control product can sensitively detect changes in the concentration of acidified solution and staining solution at the same time. It can effectively control the quality of detection reagents and experimental procedures. The new commercial sperm DFI quality control product can effectively control sperm DNA integrity testing. It can be used as an external quality control product for quality control of test results to ensure that more accurate test results are provided to the clinic.

Omics and Male Infertility: Highlighting the Application of Transcriptomic Data

Male infertility is a multifaceted disorder affecting approximately 50% of male partners in infertile couples. Over the years, male infertility has been diagnosed mainly through semen analysis, hormone evaluations, medical records and physical examinations, which of course are fundamental, but yet inefficient, because 30% of male infertility cases remain idiopathic. This dilemmatic status of the unknown needs to be addressed with more sophisticated and result-driven technologies and/or techniques. Genetic alterations have been linked with male infertility, thereby unveiling the practicality of investigating this disorder from the “omics” perspective. Omics aims at analyzing the structure and functions of a whole constituent of a given biological function at different levels, including the molecular gene level (genomics), transcript level (transcriptomics), protein level (proteomics) and metabolites level (metabolomics). In the current study, an overview of the four branches of omics and their roles in male infertility are briefly discussed; the potential usefulness of assessing transcriptomic data to understand this pathology is also elucidated. After assessing the publicly obtainable transcriptomic data for datasets on male infertility, a total of 1385 datasets were retrieved, of which 10 datasets met the inclusion criteria and were used for further analysis. These datasets were classified into groups according to the disease or cause of male infertility. The groups include non-obstructive azoospermia (NOA), obstructive azoospermia (OA), non-obstructive and obstructive azoospermia (NOA and OA), spermatogenic dysfunction, sperm dysfunction, and Y chromosome microdeletion. Findings revealed that 8 genes (LDHC, PDHA2, TNP1, TNP2, ODF1, ODF2, SPINK2, PCDHB3) were commonly differentially expressed between all disease groups. Likewise, 56 genes were common between NOA versus NOA and OA (ADAD1, BANF2, BCL2L14, C12orf50, C20orf173, C22orf23, C6orf99, C9orf131, C9orf24, CABS1, CAPZA3, CCDC187, CCDC54, CDKN3, CEP170, CFAP206, CRISP2, CT83, CXorf65, FAM209A, FAM71F1, FAM81B, GALNTL5, GTSF1, H1FNT, HEMGN, HMGB4, KIF2B, LDHC, LOC441601, LYZL2, ODF1, ODF2, PCDHB3, PDHA2, PGK2, PIH1D2, PLCZ1, PROCA1, RIMBP3, ROPN1L, SHCBP1L, SMCP, SPATA16, SPATA19, SPINK2, TEX33, TKTL2, TMCO2, TMCO5A, TNP1, TNP2, TSPAN16, TSSK1B, TTLL2, UBQLN3). These genes, particularly the above-mentioned 8 genes, are involved in diverse biological processes such as germ cell development, spermatid development, spermatid differentiation, regulation of proteolysis, spermatogenesis and metabolic processes. Owing to the stage-specific expression of these genes, any mal-expression can ultimately lead to male infertility. Therefore, currently available data on all branches of omics relating to male fertility can be used to identify biomarkers for diagnosing male infertility, which can potentially help in unravelling some idiopathic cases.

Reproductive function in men conceived with in vitro fertilization and intracytoplasmic sperm injection

OBJECTIVE

To determine the semen quality and reproductive hormones of men conceived by in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) compared with men conceived without assisted reproductive technology (ART).

DESIGN

Cohort study.

SETTING

IVF centers in Victoria and the Western Australian Raine Study.

PATIENT(S)

Men conceived with IVF/ICSI and men conceived without ART aged 18-25 years.

INTERVENTION(S)

Clinical review.

MAIN OUTCOME MEASURE(S)

The primary outcome was the prevalence of severe oligozoospermia (sperm concentration, <5 million/mL). The secondary outcomes were total sperm count, total and progressive motility, total motile count, normal morphology, and serum testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

RESULTS

There was no difference in the prevalence of severe oligozoospermia between 120 men conceived with IVF/ICSI and 356 men conceived without ART (9% vs. 5.3%). Men conceived with IVF/ICSI had similar sperm concentration, total sperm count, and total motile count but lower mean total (55.3% vs. 60.6%) and progressive (44.7% vs. 53.9%) sperm motility with higher mean normal morphology (8.5% vs. 5.4%). Differences in progressive motility (ß, -9.9; 95% confidence interval [CI], -16.7 - -3.0), normal morphology (ß, 4.3; 95% CI, 3.0-5.7), and proportion with abnormal morphology (adjusted odds ratios, 0.1; 95% CI, 0.04-0.5) remained significant after adjusting for confounders. Men conceived with IVF/ICSI had lower mean FSH (3.3 IU/L) and LH (3.9 IU/L) levels and higher mean testosterone levels (19.1 nmol/L) than controls (4.2 IU/L, 11.0 IU/L, and 16.8 nmol/L).

CONCLUSION

This study of men conceived with IVF/ICSI found similar sperm output to men conceived without ART. Overall, the results are reassuring.

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.

Apoptotic M540 bodies present in human semen interfere with flow cytometry-assisted assessment of sperm DNA fragmentation and oxidation

Background

The use of flow cytometry (FC) to evaluate sperm DNA fragmentation via deoxynucleotidyl transferase terminal fluorescein dUTP nick-end labeling (TUNEL) has shown inconsistencies compared with conventional fluorescent microscopic analyses. It has been hypothesized that the observed discrepancies could be attributed to the presence of apoptotic bodies that can be labeled with merocyanine 540, the so-called M540 bodies. In order to verify this hypothesis and determine the accuracy of our in-house FC-assisted evaluation of spermatozoa parameters, we used FC to evaluate both the fragmentation of sperm DNA using the TUNEL assay and the oxidation of sperm DNA using the 8-OHdG assay on semen samples with or without M540 bodies.

Results

We show that the presence of M540 bodies lead to underestimation of both the level of sperm DNA fragmentation and sperm DNA oxidation when using FC assisted detection systems. We also observed that this situation is particularly pertinent in semen samples classified as abnormal with respect to the routine WHO semen evaluation as they appear to contain more M540 bodies than normal samples.

Conclusions

We conclude that M540 bodies interfere with both FC-conducted assays designed to evaluate sperm nuclear/DNA integrity. Exclusion of these contaminants in unprepared semen samples should be performed in order to correctly appreciate the true level of sperm DNA/nuclear damage which is known to be a critical male factor for reproductive success.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12610-021-00143-7.

Rheotaxis-based sperm separation using a biomimicry microfluidic device

Sperm selection is crucial to assisted reproduction, influencing the success rate of the treatment cycle and offspring health. However, in the current clinical sperm selection practices, bypassing almost all the natural selection barriers is a major concern. Here, we present a biomimicry microfluidic method, inspired by the anatomy of the female reproductive tract, that separates motile sperm based on their rheotaxis behavior to swim against the flow into low shear rate regions. The device includes micropocket geometries that recall the oval-shaped microstructures of the female fallopian tube to create shear protected zones for sperm separation. Clinical tests with human samples indicate that the device is capable of isolating viable and highly motile sperm based on their rheotaxis responses, resulting in a separation efficiency of 100%. The device presents an automated alternative for the current sperm selection practices in assisted reproduction.

Chronic Prostatitis/Chronic Pelvic Pain Syndrome Leads to Impaired Semen Parameters, Increased Sperm DNA Fragmentation and Unfavorable Changes of Sperm Protamine mRNA Ratio

BACKGROUND

Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) is a frequent disease affecting men of every age and accounting for a great number of consultations at urology departments. Previous studies suggested a negative impact of CP/CPPS on fertility. As increasing attention has been attributed to additional aspects, such as sperm DNA integrity and sperm protein alterations, besides the WHO standard semen analysis when assessing male fertility, in this prospective study, we aimed to further characterize the fertility status in CP/CPPS patients with a focus on these parameters.

METHODS

Sperm DNA fragmentation measured by sperm chromatin structure assay (SCSA) and protamine 1 to protamine 2 mRNA ratio assessed by RT-qPCR were analyzed along with conventional ejaculate parameters and inflammatory markers in 41 CP/CPPS patients and 22 healthy volunteers.

RESULTS

We found significant differences between the groups concerning multiple conventional ejaculate parameters. A significant increase in sperm DNA fragmentation was shown in CP/CPPS patients with association to other sperm parameters. The majority of CP/CPPS patients exhibited protamine mRNA ratios out of the range of regular fertility.

CONCLUSIONS

This is a pioneering study with a strong practical orientation revealing that CP/CPPS leads to increased sperm DNA damage and changes in sperm protamine levels, emphasizing an unfavorable impact of CP/CPPS on fertility.

Effect and mechanisms of reproductive tract infection on oxidative stress parameters, sperm DNA fragmentation, and semen quality in infertile males

Recent years have seen a rising incidence of male infertility, mostly caused by the decline of sperm quality. The ratio of infertile males to infertile females has escalated from 3:7 in 2013 to current 5:5, which turns male infertility into the research focus of reproductive medicine. This study aimed to clarify the effect of reproductive tract infection by ureaplasma urealyticum (UU) and chlamydia trachomatis (CT) on the DNA integrity and routine semen parameters of infertile males. A retrospective study was performed. A total of 259 infertile males who were treated at the Andrological Laboratory Examination and Reproductive Medicine Center in our hospital were analyzed. qRT-PCR was used to examine the infection status of CT and UU. According to the eligibility criteria, we evaluated the semen parameters and biochemical data of 253 men. Based on the results of PCR, the subjects were divided into four groups: Group I (CT positive, 63 cases), Group II (UU positive, 60 cases), Group III (CT positive and UU positive, 62 cases), and Group IV (no infection, 68 cases). DNA fragmentation index (DFI), sperm count, vitality and morphology, elastase level, seminal plasma malondialdehyde (MDA), and total antioxidant capacity (TAC) were assessed. Compared to Group IV, three groups (Group I, Group II and Group III) showed difference in semen volume, proportion of sperm with normal morphology, sperm motility, progressive motility, and vitality (P < 0.05). Compared to Group IV, Group II and Group III showed difference in DFI (P < 0.05). Compared to Group IV, Group II and Group III showed difference in elastase level (P < 0.05). VCL, VSL, VAP, WOB, ROS, TM, HDS showed differences between groups of abnormal/normal WBC (*P < 0.01).UU infection significantly increased the level of seminal leukocytes only in Group II, but not in the other three groups, indicating that UU is a factor to increase the level of seminal leukocytes. Compared with the normal leukocyte group, there were significant differences in total motility, forward motility and normal sperm ratio between the two groups. The proportion of sperm with abnormal morphology (mostly in the head) showed obvious difference between groups of high and normal seminal leukocytic levels. At the same time, in this study, SCGE and SCD verified that leukocytes could damage sperm DNA by increasing ROS, which ultimately affects male fertility.

Implementation of an in-house flow cytometric analysis of DNA fragmentation in spermatozoa

An increased amount of DNA fragmentation in the spermatozoa (SDF) is linked to male infertility. The Sperm Chromatin Structure Assay (SCSA) is widely used for analysis of SDF. However, the current software (SCSASoft^®) linked to this assay is licensed and often located within larger diagnostic centers. In this study, we present a protocol for using other types of software than SCSASoft^® to determine the SDF index (DFI) with clinical relevance. This protocol is engineered after collecting and analyzing 254 samples from fertility patients and sperm donors over a 15-month period. DFI is analyzed using a strict protocol where the spermatozoa are treated with a strong acid (pH 1.2) followed by acridine orange. DFI is determined by a standard flow cytometric software, FACSDiva 6.1.3. Analysis of the outcome of the fertility treatment is included for 137 patients receiving either intrauterine inseminations (IUI) or timed coitus (TC). The results show that the chance of pregnancy declines as DFI increases. We also found that the male DFI affects the chance of pregnancy independent of the female age. We have shown that a standard flow cytometric software can be used when determining a clinical relevant DFI. These findings are a significant step toward implementing the analysis as a part of the routine, in-house diagnosing of the male fertility patient and subsequently optimizing the treatment course of the couple with reduced human and financial costs.

Negative Impact of Elevated DNA Fragmentation and Human Papillomavirus (HPV) Presence in Sperm on the Outcome of Intra-Uterine Insemination (IUI)

We wanted to determine the sperm DNA fragmentation index (DFI) cutoff for clinical pregnancies in women receiving intra-uterine insemination (IUI) with this sperm and to assess the contribution of Human Papillomavirus (HPV) infection on sperm DNA damage and its impact on clinical pregnancies. Prospective non-interventional multi-center study with 161 infertile couples going through 209 cycles of IUI in hospital fertility centers in Flanders, Belgium. Measurement of DFI and HPV DNA with type specific quantitative PCRs (HPV 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68) in sperm before its use in IUI. Clinical pregnancy (CP) rate was used as the outcome to analyze the impact on fertility outcome and to calculated the clinical cutoff value for DFI. A DFI criterion value of 26% was obtained by receiver operating characteristic (ROC) curve analysis. Couples with a male DFI > 26% had significantly less CPs than couples with DFI below 26% (OR 0.0326; 95% CI 0.0019 to 0.5400; p = 0.017). In sperm, HPV prevalence was 14.8%/IUI cycle. Sperm samples containing HPV had a significantly higher DFI compared to HPV negative sperm samples (29.8% vs. 20.9%; p = 0.011). When HPV-virions were present in sperm, no clinical pregnancies were observed. More than 1 in 5 of samples with normal semen parameters (17/78; 21.8%) had an elevated DFI or was HPV positive. Sperm DFI is a robust predictor of clinical pregnancies in women receiving IUI with this sperm. When DFI exceeds 26%, clinical pregnancies are less likely and in vitro fertilization techniques should be considered.

Health and fertility of ICSI-conceived young men: study protocol

STUDY QUESTIONS

What are the long-term health and reproductive outcomes for young men conceived using ICSI whose fathers had spermatogenic failure (STF)? Are there epigenetic consequences of ICSI conception?

WHAT IS KNOWN ALREADY

Currently, little is known about the health of ICSI-conceived adults, and in particular the health and reproductive potential of ICSI-conceived men whose fathers had STF. Only one group to date has assessed semen parameters and reproductive hormones in ICSI-conceived men and suggested higher rates of impaired semen quality compared to spontaneously conceived (SC) peers. Metabolic parameters in this same cohort of men were mostly comparable. No study has yet evaluated other aspects of adult health.

STUDY DESIGN SIZE DURATION

This cohort study aims to evaluate the general health and development (aim 1), fertility and metabolic parameters (aim 2) and epigenetic signatures (aim 3) of ICSI-conceived sons whose fathers had STF (ICSI study group). There are three age-matched control groups: ICSI-conceived sons whose fathers had obstructive azoospermia (OAZ) and who will be recruited in this study, as well as IVF sons and SC sons, recruited from other studies. Of 1112 ICSI parents including fathers with STF and OAZ, 78% (n = 867) of mothers and 74% (n = 823) of fathers were traced and contacted. Recruitment of ICSI sons started in March 2017 and will finish in July 2020. Based on preliminary participation rates, we estimate the following sample size will be achieved for the ICSI study group: mothers n = 275, fathers n = 225, sons n = 115. Per aim, the sample sizes of OAZ-ICSI (estimated), IVF and SC controls are: Aim 1-OAZ-ICSI: 28 (maternal surveys)/12 (son surveys), IVF: 352 (maternal surveys)/244 (son surveys), SC: 428 (maternal surveys)/255 (son surveys); Aim 2-OAZ-ICSI: 12, IVF: 72 (metabolic data), SC: 391 (metabolic data)/365 (reproductive data); Aim 3-OAZ-ICSI: 12, IVF: 71, SC: 292.

PARTICIPANTS/MATERIALS SETTING METHODS

Eligible parents are those who underwent ICSI at one of two major infertility treatment centres in Victoria, Australia and gave birth to one or more males between January 1994 and January 2000. Eligible sons are those aged 18 years or older, whose fathers had STF or OAZ, and whose parents allow researchers to approach sons. IVF and SC controls are age-matched men derived from previous studies, some from the same source population. Participating ICSI parents and sons complete a questionnaire, the latter also undergoing a clinical assessment. Outcome measures include validated survey questions, physical examination (testicular volumes, BMI and resting blood pressure), reproductive hormones (testosterone, sex hormone-binding globulin, FSH, LH), serum metabolic parameters (fasting glucose, insulin, lipid profile, highly sensitive C-reactive protein) and semen analysis. For epigenetic and future genetic analyses, ICSI sons provide specimens of blood, saliva, sperm and seminal fluid while their parents provide a saliva sample. The primary outcomes of interest are the number of mother-reported hospitalisations of the son; son-reported quality of life; prevalence of moderate-severe oligozoospermia (sperm concentration <5 million/ml) and DNA methylation profile. For each outcome, differences between the ICSI study group and each control group will be investigated using multivariable linear and logistic regression for continuous and binary outcomes, respectively. Results will be presented as adjusted odds ratios and 95% CIs.

STUDY FUNDING/COMPETING INTERESTS

This study is funded by an Australian National Health and Medical Research Council Partnership Grant (NHMRC APP1140706) and was partially funded by the Monash IVF Research and Education Foundation. L.R. is a minority shareholder and the Group Medical Director for Monash IVF Group, and reports personal fees from Monash IVF group and Ferring Australia, honoraria from Ferring Australia, and travel fees from Merck Serono, MSD and Guerbet; R.J.H. is the Medical Director of Fertility Specialists of Western Australia and has equity in Western IVF; R.I.M. is a consultant for and a shareholder of Monash IVF Group and S.R.C. reports personal fees from Besins Healthcare and non-financial support from Merck outside of the submitted work. The remaining authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

Not applicable.

TRIAL REGISTRATION DATE

Not applicable.

DATE OF FIRST PATIENT’S ENROLMENT

Not applicable.

The relationship between semen factors and unexplained recurrent spontaneous abortion

BACKGROUND

The male factor may contribute to unexplained recurrent spontaneous abortion (URSA). The relationship between semen factors and URSA is largely unknown. The analysis of metabolomics which is broadly acknowledged as the omics closest to the phenotype is suitable for providing assistance in the semen parameters analysis.

METHODS

We conducted a study including couples with URSA and controls which was next combined with a meta-analysis, and finally the study included 2352 subjects on semen parameters and URSA. Metabolomics analysis was conducted to detect semen metabolic factors related to URSA in total of 106 samples including seminal plasma and sperm cells.

RESULTS

The URSA group had significantly lower total sperm count, sperm concentration, motility and normal morphology percentage. Meta-analysis next showed consistent findings. Metabolomics revealed that 4 metabolites and one pathway and 8 metabolites and one pathway were significantly associated with URSA in sperm and seminal plasma, respectively. The combination of ascorbic acid and guanine in seminal plasma and hexadecanedioic acid and pyroglutamic acid in sperm showed ability for URSA prediction.

CONCLUSION

We provided novel insights into semen indices in relation to URSA. Lower sperm number and quality might increase the risk of URSA, and oxidative stress and hormone metabolism in sperm as well as nucleic acid synthesis and oxidative stress in seminal plasma were related to URSA.

Beyond fertilisation: How the paternal environment influences future generations

In light of the relatively ignored role of paternal influences on offspring development and increasing societal concerns regarding possible health consequences of chemical exposures, our team has addressed the overall hypothesis that environmentally-relevant levels of contaminants have long-lasting effects that are transmitted through the paternal lineage. This review focuses on our research examining the impact of developmental exposure to toxicants and nutrients on the phenotype and epigenome of the male and of his subsequent generations. This report is intended to encourage animal andrologists as well as the domestic animal production industry to increase their consideration of the sire's environment in the context of agricultural productivity.

Sperm DNA fragmentation index with unexplained recurrent spontaneous abortion: A systematic review and meta-analysis

BACKGROUND

A high sperm DNA fragmentation index (DFI) influences human reproduction and is observed in infertile men. However, the influence of DFI on unexplained recurrent spontaneous abortion (RSA) remains controversial.

OBJECTIVE

We explored the influence of DFI on unexplained recurrent spontaneous abortion.

DATA SOURCES

We conducted a meta-analysis of DFI (assessed by sperm chromatin structure assay(SCSA), terminal deoxynucleotidyl transferase-mediated deoxyuridine (TdT)triphosphate (dUTP) nick end labeling assay(TUNEL), sperm chromatin dispersion(SCD), single cell gel electrophoresis assay(COMET assay), and acridine orange test(AOT) with unexplained RSA from the Cochrane Library, EMBASE, Pubmed and Web of Science database.

METHODS

Records were screened for eligible studies and data were extracted to an online data extraction form. The main outcome was the sperm DFI. Summary measures were reported as the mean difference(MD) and Odds Ratio(OR) with 95 % confifidence interval (CI).

RESULT

We identified 27 articles including 3, 2, 9, 9, and 8 studies using AO, COMET, SCSA, SCD and TUNEL respectively; 7 articles used qualitative methods and 21 articles used in quantitative methods. The combined MD estimates of 7 SCSA studies (MD=5.4; 95 % CI: 1.76-9.03; P<0.01), 9 SCD studies (MD=11.16; 95 % CI:6.70-15.62; P<0.01), and 8 TUNEL studies (MD=12.12; 95 % CI: 3.34-20.91; P<0.01) showed significant differences. Notably, qualitative studies showed consistent results with quantitative studies.

CONCLUSION(S)

These findings support an association between sperm DFI and recurrent pregnancy loss. Previous studies revealed that DFI negatively impacts unexplained RSA.

Future diagnostics in male infertility: genomics, epigenetics, metabolomics and proteomics

A male factor is involved in 50% of couples with infertility. Unfortunately, the etiology of male factor infertility remains classified as idiopathic in nearly 50% of cases. The semen analysis (SA) continues to be first line for the workup of male infertility, but it is an imperfect test with high variability between samples. This lack of diagnostic capability has led to the desire to develop minimally invasive tests to aid with understanding the etiology of male factor infertility. Genetic factors are known to play a role in male infertility, and much work has been done to identify the many genes involved. The study of the genes involved, the impact of epigenetic modifications, proteins and metabolites produced are attractive targets for development of biomarkers which may be used to diagnose the etiology of male infertility. This review aims to explore recent advances in these fields as they pertain to the diagnosis of male infertility.

The incidence and etiology of sperm DNA fragmentation in the ejaculates of males with spinal cord injuries

STUDY DESIGN

Retrospective descriptive study.

OBJECTIVES

To determine the incidence and probable etiology of sperm DNA fragmentation (SDF) in a sample of males with spinal cord injury (SCI).

SETTING

Hospital in Toledo, Spain; University-based Genetics laboratory in Madrid, Spain.

METHODS

Semen collected by vibro-stimulation from 27 males with various levels of spinal cord injury. Classical semen parameters, SDF, leukocytospermia and pro-oxidant capacity were assessed and compared with a cohort of normozoospermic fertile donors (n = 10).

RESULTS

Males with SCI presented with lower semen quality compared with normozoospermic donors with respect to progressive motility (p = 0.0002), SDF (p < 0.00005), pro-oxidant capacity (p = 0.0191) and leukocytospermia (p < 0.00005). Although there was no significant correlation between semen quality and time since the lesion occurred, the period of abstinence appeared to be positively correlated with SDF (r = 0.486; p = 0.041). When the semen parameters of males with SCI were categorized based on those with cervical and thoracic lesions, sperm concentration was higher for those with cervical damage (p = 0.0257). Males with complete lesions (AIS A) had ejaculates that were lower in progressive motility (p = 0.0040) than those with incomplete injuries (AIS B-D).

CONCLUSIONS

Ejaculates of males with SCI have excessively elevated SDF when compared with normozoospermic donors, which is likely to be associated with coincident high levels of leucocytospermia and pro-oxidant capacity. We propose that these phenomena are caused by the accumulation and degeneration of spermatozoa in the cauda epididymidis.

Redox Regulation and Oxidative Stress: The Particular Case of the Stallion Spermatozoa

Redox regulation and oxidative stress have become areas of major interest in spermatology. Alteration of redox homeostasis is recognized as a significant cause of male factor infertility and is behind the damage that spermatozoa experience after freezing and thawing or conservation in a liquid state. While for a long time, oxidative stress was just considered an overproduction of reactive oxygen species, nowadays it is considered as a consequence of redox deregulation. Many essential aspects of spermatozoa functionality are redox regulated, with reversible oxidation of thiols in cysteine residues of key proteins acting as an “on–off” switch controlling sperm function. However, if deregulation occurs, these residues may experience irreversible oxidation and oxidative stress, leading to malfunction and ultimately death of the spermatozoa. Stallion spermatozoa are “professional producers” of reactive oxygen species due to their intense mitochondrial activity, and thus sophisticated systems to control redox homeostasis are also characteristic of the spermatozoa in the horse. As a result, and combined with the fact that embryos can easily be collected in this species, horses are a good model for the study of redox biology in the spermatozoa and its impact on the embryo.

Relationship between Sperm Parameters with Sperm Function Tests in Infertile Men with at Least One Failed Cycle after Intracytoplasmic Sperm Injection Cycle

Background

Imbalance between production of reactive oxygen species (ROS) and total antioxidant capacity in testis, epididymis, and seminal fluid can eventually lead to infertility. Abnormal sperm chromatin packaging, and DNA fragmentation is considered as the main underlying causes of infertility. Therefore, we aimed to assess relationship between sperm parameters with DNA damage, protamine deficiency, persistent histones, and lipid peroxidation in infertile men with at least one failed cycle after intracytoplasmic sperm injection (ICSI).

Materials and Methods

In this experimental study, semen samples were collected from infertile men with at least one failed intracytoplasmic sperm injection (ICSI) cycle (n=20). Sperm parameters, DNA damage, protamine de- ficiency, persistent histones, and lipid peroxidation were assessed using computer-assisted sperm analysis (CASA) system, sperm chromatin structure assay (SCSA) and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays, chromomycin A3, aniline blue, and BODIPY C11 staining, respectively.

Results

A negative significant correlation was observed between sperm concentration with percentage of sperm persistent histones (r=-0.56, P=0.02), while positive significant correlations were found between percentage of sperm persistent histones with percentage of abnormal morphology (r=0.54, P=0.02), CMA3-positive spermatozoa (r=o.6, P=0.008) and intensity of lipid peroxidation (r=0.6, P=0.01). In addition, significant correlation was observed be- tween sperm DNA damage with intensity and percentage of lipid peroxidation (r=0.62, P=0.009). Correlation between CMA3-positive spermatozoa and intensity of lipid peroxidation (r=0.5, P=0.03) were also significant.

Conclusion

Observed significant correlations between sperm functional tests in infertile men with at least one failed ICSI cycle, indicated that the reduction of oxidative stress by antioxidant supplementation may be considered as one therapy approach that can improve sperm function and increase the chance of successful clinical outcomes in next assisted reproductive cycle.

New perspectives on male fertility evaluation: Innovative approach for the qualitative analysis of spermatozoa

The identification of idiopathic infertility cases, actually, is impossible. Among new functional tests, developed to improve the male fertility diagnosis, the evaluation of spermatic myo-inositol (MI) level, known as Andrositol^® test (AT), is one of the most interesting, considering its weak economic burden and ease of use. The aim of this study was to evaluate the predictive power of AT and its potential use for a preliminary evaluation of semen samples. To evaluate the predictive power of AT, 87 sperm samples were analysed in comparison with spermiogram and sperm chromatin dispersion (SCD) Test, the gold standard analyses for male fertility evaluation. The application of AT resulted very useful for a preliminary sample evaluation, predicting the absence of DNA fragmentation in case of Low Responder samples precisely, and the presence of DNA fragmentation in case of medium or High Responder samples with abnormal morphology, predicting SCD results with a probability of 80% for Medium Responder sample and of 96.7% for High Responder sample. Considering the predictive power of this method, we could imagine, as preliminary qualitative analysis, its application before SCD test, deepening sperm analysis, improving the daily activities of laboratory operators and maintaining a good reliability of sperm evaluation.

Association between semen quality among men with different occupational exposures and risk of recurrent spontaneous abortion in island residents

Objective: This study aimed to evaluate the semen quality of male adults whose spouses suffer from recurrent spontaneous abortion (RSA) in the island area, and to explore the association between RSA and occupational exposures.

Methods: A total of 131 male patients were recruited and divided into two groups: spouse with recurrent spontaneous abortion group (RSA group, [Formula: see text]) and the normal fertility group (control group, [Formula: see text]). Information such as height, weight and occupational exposure history of 131 men were obtained. Semen samples were collected and analyzed. Differences in semen parameters and DNA fragmentation index (DFI) between the two groups were compared. Odds ratios (ORs) and their corresponding 95% confidence intervals were calculated to evaluate the association between occupational exposures and RSA status.

Results: Overall, no significant difference was found in sperm concentration, progressive motility and normal morphology rate between RSA and control groups. Only DFI was observed to be significantly higher in the RSA group. Evaluation of the receiver operating characteristic (ROC) curve showed DFI (AUC: 0.623, [Formula: see text]) could discriminate between males from the couples with RSA and without RSA.

Conclusion: The analysis of conventional semen parameters could not directly reflect their influence on embryonic development, and test of integrity of the sperm DNA is of paramount importance to fully understand male fertility. It is crucial to conduct studies regarding occupational exposures and pregnancy loss and/or RSA risk, since it will provide population-level data to aid in the identification of important risk factors that warrant further mechanistic investigation, and eventually lead to effective prevention and treatment strategies.

Utility and Predictive Value of Human Standard Semen Parameters and Sperm DNA Dispersion for Fertility Potential

Because the assessment of sperm DNA fragmentation (SDF) plays a key role in male fertility, our study was designed to find the relationships between SDF and standard semen parameters. The receiver operating characteristic (ROC) curve showed that 18% SDF is a prognostic parameter for discriminating between men with normal and abnormal standard semen parameters (n = 667). Men with > 18% SDF had significantly lower quality semen, a higher prevalence of abnormal semen characteristics, and a higher odds ratio for abnormal semen parameters compared to men with ≤ 18% SDF. An ROC analysis provided predictive values for age and semen parameters to distinguish between men with SDF > 18% and men with ≤ 18% SDF. SDF was positively correlated with male age and teratozoospermia index but negatively with sperm concentration, total number of spermatozoa, sperm morphology, progressive motility, and vitality. Our study shows that 18% SDF has a predictive value for distinguishing between men with normal and abnormal semen characteristics. Men with >18% SDF have a higher risk for abnormal semen parameters, while age and obtained semen parameters have a predictive value for SDF. There is a relationship between SDF and conventional sperm characteristics, and thus, SDF can be incorporated into male fertility assessment.

Independent and combined effects of diethylhexyl phthalate and polychlorinated biphenyl 153 on sperm quality in the human and dog

A temporal decline in human and dog sperm quality is thought to reflect a common environmental aetiology. This may reflect direct effects of seminal chemicals on sperm function and quality. Here we report the effects of diethylhexyl phthalate (DEHP) and polychlorinated biphenyl 153 (PCB153) on DNA fragmentation and motility in human and dog sperm. Human and dog semen was collected from registered donors (n = 9) and from stud dogs (n = 11) and incubated with PCB153 and DEHP, independently and combined, at 0x, 2x, 10x and 100x dog testis concentrations. A total of 16 treatments reflected a 4 × 4 factorial experimental design. Although exposure to DEHP and/or PCB153 alone increased DNA fragmentation and decreased motility, the scale of dose-related effects varied with the presence and relative concentrations of each chemical (DEHP.PCB interaction for: DNA fragmentation; human p < 0.001, dog p < 0.001; Motility; human p < 0.001, dog p < 0.05). In both human and dog sperm, progressive motility negatively correlated with DNA fragmentation regardless of chemical presence (Human: P < 0.0001, r = −0.36; dog P < 0.0001, r = −0.29). We conclude that DEHP and PCB153, at known tissue concentrations, induce similar effects on human and dog sperm supporting the contention of the dog as a sentinel species for human exposure.

Evaluation of Sperm DNA Fragmentation via Halosperm Technique and TUNEL Assay Before and After Cryopreservation

AIM

Human sperm DNA fragmentation is one of the factors suggested for male infertility. The ratio of sperm DNA damage in semen may adversely affect both the fertilization rate and the embryo development of in vitro fertilization/ intracytoplasmic sperm injection cycles. Sperm cryopreservation both increases the success rates in assisted reproductive techniques (ARTs) and contributes to the preservation of fertility before testis surgery, chemotherapy, and radiotherapy. The aim of the current study is to determine sperm DNA fragmentation, following cryopreservation.

METHODS

A cross-sectional, observational study was conducted at a university hospital infertility clinic. One hundred (n = 100) volunteer fertile men (ages between 21 and 39 years) with normozoospermic sperm parameters were involved in the current study. Sperm DNA damage was evaluated with the Halosperm technique and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. Fresh samples were studied in liquid form. The remaining samples were kept frozen and then thawed after 1 month and reevaluated with the Halosperm technique and TUNEL assay. Results were then compared between the fresh and frozen samples.

RESULTS

Sperm DNA fragmentation results with the Halosperm technique both before and after cryopreservation were 25% (5%-65%) and 40% (6%-89%), respectively, with a statistically significant increase (15%; P < .001). Sperm DNA fragmentation results by TUNEL assay before and after cryopreservation were 17% (3%-43%) and 36% (7%-94%), respectively, with a statistically significant increase (19%; P <.001).

CONCLUSION

The current data demonstrate increased sperm DNA damage after cryopreservation. Further studies may contribute to development of less harmful techniques and cryoprotectants in order to improve the results of ART.

Association between semen parameters and chance of fatherhood - a long-term follow-up study

BACKGROUND

Evaluation of male fertility includes standard semen analysis; however, there is uncertainty about the value of sperm parameters in predicting fertility.

OBJECTIVE

To evaluate the association between semen parameters and fatherhood during a long-time period.

MATERIALS AND METHODS

Semen parameters (total sperm count, concentration, motility, and morphology) and sperm DNA fragmentation Index (DFI) assessed on samples collected from 195 Norwegian men from the general population in 2001/2002 were matched with information about fatherhood until 2015, obtained from the Medical Birth Register. The parameters were dichotomized as normal vs. abnormal according to the WHO reference values from 1999 and 2010. Cut-offs at 20% and 30% were used for DFI.

RESULTS

Among men who had no children before 2003, those with normal progressive sperm motility had more often become fathers (WHO 1999, cut-off ≥50%, adjusted OR 2.8, 95% CI 1.3-6.1 and WHO 2010, cut-off ≥32%; aOR 4.2, 95% CI 1.1-15). Based on the WHO 1999 reference value, men with normal sperm concentration (≥20 × 10⁶ /mL) had more often become fathers (aOR 3.1, 95% CI 1.1-8.6). Men with progressive sperm motility ≥50% and concentration ≥20 × 10⁶ /mL did more often achieve fatherhood (aOR 8.4, 95% CI 2.1-34). For DFI, there was a borderline significance at cut-off 20% in the group of men who had ever been fathers (OR 2.7, 95% CI 1.0-7.0 p < 0.05).

DISCUSSION

The results indicate that sperm progressive motility, sperm concentration, and DFI are associated with fatherhood during a longer time period, with sperm motility being most consistent. Although the sample size is relatively small and our results should be replicated in larger studies, they may be of clinical relevance.

CONCLUSION

Semen parameters may have a diagnostic value not only in a short time frame but also for predicting future fertility potential.

Assessing the potential of HSPA2 and ADAM2 as two biomarkers for human sperm selection

Selection of the best sperm, with the least defects, is a critical factor in the success of ART especially in male factor infertility. This study assessed the potential Heat shock protein (HSPA2) and metallopeptidase domain2 (ADAM2) biomarkers for sperm selection. Sperm were obtained from 72 asthenoteratozoospermic and 42 normospermic ejaculates. The semen characteristic, DNA fragmentation (DFI), chromatin maturation index (CMI), ADAM2 and HSPA2 levels on sperm, and their correlation with embryo quality were assessed in both groups. Results showed the significant reduction in HSPA2 and ADAM2 in asthenoteratozoospermic compared to normazoospermic ejaculates regarding the cut-off value of 14 and 13% for these two biomarkers. The specificity of HSPA2 and ADAM2 separately, and the combination of these two biomarkers, were 95.2, 90.5 and 93.5%, respectively, for sperm from normozoospermic ejaculates. However, they were 48.6, 50.0 and 54.5% for asthenoteratozoospermic ones. A significant correlation was observed with HSPA2, ADAM2 and a combination of these two biomarkers with CMI, DFI and embryo quality. Although a combination of these two biomarkers have the potential to be a good choice for selecting sperm with the lowest level of chromatin damage, it seems that selection according to HSPA2 has priority over ADAM2 or a combination of the two.

Oxidative Stress in the Male Germline: A Review of Novel Strategies to Reduce 4-Hydroxynonenal Production

Germline oxidative stress is intimately linked to several reproductive pathologies including a failure of sperm-egg recognition. The lipid aldehyde 4-hydroxynonenal (4HNE) is particularly damaging to the process of sperm-egg recognition as it compromises the function and the stability of several germline proteins. Considering mature spermatozoa do not have the capacity for de novo protein translation, 4HNE modification of proteins in the mature gametes has uniquely severe consequences for protein homeostasis, cell function and cell survival. In somatic cells, 4HNE overproduction has been attributed to the action of lipoxygenase enzymes that facilitate the oxygenation and degradation of ω-6 polyunsaturated fatty acids (PUFAs). Accordingly, the arachidonate 15-lipoxygenase (ALOX15) enzyme has been intrinsically linked with 4HNE production, and resultant pathophysiology in various complex conditions such as coronary artery disease and multiple sclerosis. While ALOX15 has not been well characterized in germ cells, we postulate that ALOX15 inhibition may pose a new strategy to prevent 4HNE-induced protein modifications in the male germline. In this light, this review focuses on (i) 4HNE-induced protein damage in the male germline and its implications for fertility; and (ii) new methods for the prevention of lipid peroxidation in germ cells.

Is sperm DNA fragmentation a useful test that identifies a treatable cause of male infertility?

The present-day laboratory methods of sperm analysis are a poor predictor of reproductive outcome, and for many years it has been clear that newer and better tests are required. Although many such tests have been proposed, only those which determine sperm DNA quality are still being considered. Of these, several tests of sperm DNA fragmentation are available, although there is presently no consensus about the most appropriate test, the best test specimen (fresh or washed sperm) or what level of fragmentation is of clinical concern. Moreover, although several strategies have been proposed to reduce DNA fragmentation, there is no universal approach and few randomised trials have tested these in a clinical context. As such, most professional bodies do not presently support the use of sperm DNA fragmentation tests, and it is clear that large randomised trials are still required to further evaluate their clinical effectiveness.

Apoptosis Is a Demanding Selective Tool During the Development of Fetal Male Germ Cells

Apoptosis is widely known to play a major role on diseases related to male infertility. Diseases of the male genital tract as defective spermatogenesis, decreased sperm motility, sperm DNA fragmentation, testicular torsion, varicocele and immunological infertility are strongly related to apoptotic cell death. Apoptosis must not be considered only as a fail on germ cell physiology or a secondary effect of certain pathologies and exogenous hazardous agents. Apoptosis orchestrates correct function and development of the male germ cell from the early embryonic stages of gonadal differentiation to the fertilization. In this review we have tried to address a reading frame of the main knowledge about apoptosis in male germ cell development. Focussing on mechanisms concerning cellular apoptosis, which are independent of exogenous stimuli, we aimed to highlight that apoptosis is a selective instrument that guarantees the delivery of genetic message to offspring.

Associations of sperm DNA fragmentation with lifestyle factors and semen parameters of Saudi men and its impact on ICSI outcome

BACKGROUND

Male factor infertility is quite common as 30-50% of infertility cases are due to sperm defects. The high sperm DNA fragmentation is one of the causes of male factor infertility. Many factors cause sperm DNA fragmentation and could be testicular or post-testicular. The purpose of this study was to assess relationships among sperm DNA fragmentation, lifestyle factors and semen values of Saudi men and to determine impact of sperm DNA fragmentation on ICSI cycle outcome.

METHODS

The duration of this study was from January 2015 to June 2016. The cases with female factor infertility were excluded. In total 94 couples were selected for investigation. The study parameters were male age, body mass index, smoking, semen values, % sperm DNA fragmentation, fertilization rate and pregnancy outcome. The ICSI procedure was performed in all patients per standard protocol. The semen samples were grouped based on % sperm DNA fragmentation into < 15%, 15-30 and > 30% which corresponded to low, moderate and high sperm DNA fragmentation, respectively.

RESULTS

There was no difference in ICSI outcome in low and moderate sperm DNA fragmentation, however, in high sperm DNA fragmentation no patient achieved pregnancy. In this study, 53.19% Saudi men had low, 32.98% moderate and 13.83% high DFI. Semen volume, sperm morphology and fertilization rate did not show any correlation trend with DNA fragmentation, however, sperm concentration and motility were negatively correlated in all DFI categories. The BMI was positively correlated in moderate DFI category and smoking was positively correlated with low DFI category. The age was positively correlated in moderate and high DFI categories.

CONCLUSIONS

The results of this study indicated that 14% Saudi men had high DNA fragmentation. The BMI was positively correlated in moderate DFI category and smoking was positively correlated with low DFI category. The age was positively correlated in moderate and high DFI categories.

Evaluating the Potential of Three Sperm Surface Antigens as Egg-adhesion Biomarkers for Human Sperm Selection

BACKGROUND

The selection of sperm with good genomic integrity and surface antigens is suggested for improving assisted reproductive technology (ART) outcome. The aim of this study was evaluating the heat shock protein (HSPA2), Dj-1 and serum amyloid P compound (SAP) three sperm surface proteomes as biomarkers for this purpose.

METHODS

In this study, semen samples were obtained from 114 men who presented at Avicenna Fertility Clinic for their treatment. The semen characteristics, DNA fragmentation Index (DFI), chromatin maturation index (CMI), biomarker levels, and their embryo quality were considered. The paired-samples t-test and independent-samples t-test were used for analyzing the data and p-values<0.05 were considered significant.

RESULTS

Outcomes exhibited the major reduction in HSPA2, DJ-1 and SAP following reduction in sperm quality and DNA integrity (p<0.001) with cut-off value of 14% (HSPA2), 12% (DJ-1) and 10% (SAP). The specificity of these three biomarkers was 95.2, 73.8 and 88.1%, respectively. Also, DFI (p<0.001), CMI (p<0.05), cleavage (p<0.05), and embryos quality (p<0.001) decreased significantly in abnormal spermiogram (ANS) group in compared with normal spermiogram (NS) group. It was shown that DFI was 97.1% in HSPA2, 76.5% in DJ-1 and 94.1% in SAP, and CMI was 95.0%, 75.50% and 87.5%, respectively. The significant correlation was found between of the three biomarkers and CMI (p<0.001), DFI (p<0.001) and embryos quality (p<0.001).

CONCLUSION

By comparing the efficiency of these three biomarkers for selecting sperm with the lowest level of chromatin damages, it seems that selection based on HSPA2 has significance over others.

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.