One out of two idiopathic infertile men has pathologic sperm DNA fragmentation values: Potential implications for clinical practice.

OBJECTIVES: To investigate the distribution of sperm DNA fragmentation (SDF) values and their association with clinical and seminal parameters in idiopathic infertile men. DESIGN, PATIENTS, MEASUREMENTS: Data from 3224 primary infertile men (belonging to couples having failed to conceive a pregnancy within 12 months) who underwent a thorough diagnostic work-up were analysed. A SDF value ≥ 30% (according to Sperm Chromatin Structure Assay) was considered pathologic. We excluded: (1) men with genetic abnormalities; (2) men with history of cryptorchidism; (3) men with biochemical hypogonadism; (4) men with clinical varicocele; and (5) men with other possible known aetiological factors. Descriptive statistics and logistic regression analyses were used to describe the whole cohort. RESULTS: Of all, 792 (23%) men with at least one abnormal WHO semen parameter but without any identified aetiologic factor for infertility, were considered as idiopathic infertile men. Of 792, 418 (52.7%) men had SDF ≥30%. Men with pathologic SDF were older (p = .02), had higher Follicle-stimulating hormone (FSH) (p = .04) but lower total testosterone (p = .03) values than those with SDF <30%. The homoeostatic model assessment index for insulin resistance (HOMA-IR) was higher in men with SDF ≥30% (p = .01). Idiopathic infertile men with SDF ≥30% presented with lower sperm concentration (p < .001) and lower progressive sperm motility (p < .01) than those with SDF < 30%. Logistic regression analysis revealed that older age (OR: 1.1, p = .02) and higher HOMA-IR score (OR: 1.8, p = .03) were associated with SDF ≥ 30%, after accounting for FSH and sperm concentration values. CONCLUSIONS: Approximately half of infertile men categorized as idiopathic had pathologic SDF values. Idiopathic infertile men with pathologic SDF showed worse clinical, hormonal and semen parameters than those with normal SDF values. These results suggest that including SDF testing could be clinically relevant over the real-life management work-up of infertile men.

Research progress on the effect of sperm chromatin integrity on function and its detection methods.

Sperm chromatin not only carries genetic information such as paternal DNA, but also carries structural proteins, epigenetic information, and higher-order chromatin structures (such as matrix attachment regions and telomeres), etc. These information play an important role in embryonic development. This article mainly reviews the effects of these different information carried by sperm chromatin on sperm function and embryonic development and the research progress of related detection methods, in order to provide a theoretical basis and scientific diagnosis and treatment strategies for the etiology screening of clinical infertility, embryo arrest and recurrent miscarriage, so as to improve the pregnancy outcomes of natural conception and assisted reproduction. Keywords: sperm chromatin; epigenetics; sperm DNA damage; sperm function; higher-order chromatin structures.

Correlation of Sperm DNA Fragmentation Index With Semen Parameters, Lifestyle and Clinical Pregnancy Outcome After Intracytoplasmic Injection.

Objective: This study aimed to measure the correlation of sperm DNA fragmentation with semen parameters, lifestyle, and fertility outcomes after intracytoplasmic injection (ICSI). Materials and methods: The partners who were candidates for ICSI with a history of one In vitro fertilization (IVF) failure or male factor were recruited in the study. Semen parameters including sperm count, motility, and morphology as well as DNA fragmentation index (DFI) (that were divided into 2 groups as high (>15%), and low (≤15%) fragmentation scales) were evaluated either. The correlation of DFI with semen parameters, lifestyle, and clinical pregnancy after ICSI were compared between groups. Results: In 120 included couples, 59 men (49.2%) had DFIs ≤ 15% and 61 (50.8%) cases had DFIs >15%. In the group with higher DFI, abnormal morphology (p=0.010) was higher whereas, progressive motility (p=0.001), total motility (p<0.001), and total count (p<0.001) of sperm were significantly lower. In addition, the DFI was significantly higher in the subgroup of male infertility (0.012). Logistic regression showed that a lower risk of DFI>15% was associated with higher values of progressive motility (OR=0.97, p=0.001), total motility (OR=0.96, p=<0.001), count (OR=0.96, p=<0.001) and even clinical pregnancy (OR=0.27, p=0.011). However, a history of testicular surgery was associated with a higher risk of DFI>15% (OR=3.37, p=0.046). Although no correlation was found between male age and lifestyle components with DFI, the number of embryos was lower in DFI≥15% (p<0.001). Conclusion: DFI provide a clinically important measurement of sperm quality and have an impact on IVF outcomes; however, lifestyle components may not correlate with DFI.

H2BFWT Variations in Sperm DNA and Its Correlation to Pregnancy.

Abnormalities in sperm nuclei and chromatin can interfere with normal fertilization, embryonic development, implantation, and pregnancy. We aimed to study the impact of H2BFWT gene variants in sperm DNA on ICSI outcomes in couples undergoing ART treatment. One hundred and nineteen partners were divided into pregnant (G1) and non-pregnant (G2) groups. After semen analysis, complete DNA was extracted from purified sperm samples. The sequence of the H2BFWT gene was amplified by PCR and then subjected to Sanger sequencing. The results showed that there are three mutations in this gene: rs7885967, rs553509, and rs578953. Significant differences were shown in the distribution of alternative and reference alleles between G1 and G2 (p = 0.0004 and p = 0.0020, respectively) for rs553509 and rs578953. However, there was no association between these SNPs and the studied parameters. This study is the first to shed light on the connection between H2BFWT gene variants in sperm DNA and pregnancy after ICSI therapy. This is a pilot study, so further investigations about these gene variants at the transcriptional and translational levels will help to determine its functional consequences and to clarify the mechanism of how pregnancy can be affected by sperm DNA.

Impact of metabolic syndrome factors on sperm DNA fragmentation in males from infertile couples: A systematic review and meta-analysis.

PURPOSE: To investigate the impact of metabolic syndrome factors on sperm DNA fragmentation (sDF) in males from infertile couples. METHODS: A systematic literature search was performed across ten databases for literature published from January 1, 2013 until September 13, 2023. The protocol has been registered on PROSPERO (CRD42023458359), and the literature search strategy is adhered to the PRISMA framework. Studies that evaluated sDF, as indicated by DNA fragmentation index (%DFI), in males from infertile couples in relation to metabolic syndrome factors were included. Meta-analysis, using random effects model and Bayesian framework network, was performed, and data were presented as Standardized Mean Differences (SMD) with corresponding 95 % Confidence Interval (CI). RESULTS: Of the 2579 citations identified, eleven studies were included in this meta-analysis. The findings revealed that the %DFI was not associated with overall metabolic syndrome factors (p-tot = 0.235; SMD = 0.57 [95 %CI: -0.37, 1.52]), metabolic syndrome status (p-tot = 0.337; SMD = 0.08 [95 %CI: -0.08, 0.24), increased body mass index (p-tot = 0.237; SMD = 0.71 [95 %CI: -0.47, 1.89]), or glycaemic profile (p-tot = 0.93; SMD = 0.13 [95 %CI: -2.72, 2.98]). High levels of heterogeneity were observed (p < 0.01) in all subgroups, except for metabolic syndrome status. CONCLUSION: The association between metabolic syndrome factors and sDF is conflicting. However, interpreting the association requires caution, as confounding factors, indicated by high heterogeneity, may conceal the outcome. Metabolic syndrome may influence other factors contributing to male infertility, highlighting the importance of promoting a healthy lifestyle.

The Association of Sperm DNA Fragmentation With Serum Lipid Profile Among Males With Abnormal Semen Parameters: An Analytical Cross-Sectional Study.

BACKGROUND: Through the ages, infertility, affecting 8% to 12% of couples worldwide, has been a perturbing clinical problem. Approximately 40% to 50% of all infertility cases are due to 'male factor' infertility. Semen analysis is crucial in routinely evaluating idiopathic male infertility. Studies support the idea that semen parameters are associated with serum lipids and sperm DNA fragmentation (SDF). Therefore, it is possible to evaluate male infertility by serum lipid levels, especially before assisted reproduction technology, and modify it by bringing about lifestyle modifications. This study aimed to measure the correlation of SDF with levels of total cholesterol (TC), triglycerides (TG), very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) among males with abnormal semen parameters. METHODS: A cross-sectional analytical study was conducted in the infertility clinic of a tertiary care hospital. A total of 106 infertile males with abnormal semen analysis as per the WHO criteria (2010) were enrolled in the study. After routine semen analysis, SDF was studied using the comet assay. The serum fasting lipid profile was analyzed using the spectrophotometric kit in the autoanalyzer. The relationship of SDF with serum lipid profile parameters was analyzed. RESULTS: Out of 106 infertile men, 52% (n = 55) had severe SDF. A modest positive correlation was observed between SDF (percentage of DNA in comet tail) and serum lipid values (serum TG, serum LDL, and serum VLDL). CONCLUSIONS: Our study is novel in its research on the correlation between SDF and serum lipid values. Based on the findings of our study, it can be concluded that a significant level of SDF was observed in men with high levels of serum TG, LDL, and VLDL. This provokes a potential relationship between sperm DNA integrity and serum lipid profile, which warrants further research.

In cases with raised sperm DNA fragmentation, can sperm selection by magnetic-activated cell sorting or testicular sperm aspiration help improve reproductive outcomes?

PURPOSE: To evaluate the efficacy of magnetic-activated cell sorting (MACS) or testicular sperm aspiration (TESA) to improve reproductive outcomes in cases with elevated sperm DNA fragmentation undergoing assisted reproduction. METHODS: This randomized controlled trial included couples with failed IVF cycles and sperm DNA fragmentation > 30%. Sperm DNA fragmentation was assessed using the sperm chromatin structure assay (SCSA) method. Participants were randomly assigned to either the MACS or TESA group. Testicular sperm retrieval was performed for the TESA group, while MACS involved sperm selection using magnetic beads. Extended blastocyst culture, freeze all policy of blastocysts by vitrification, and frozen embryo transfer were undertaken as per clinic's standard operating protocols. Blastocyst formation rate, implantation rate, miscarriage rate, multiple pregnancy rate, and live birth rate were analyzed and compared between MACS and TESA groups. RESULTS: There were no significant differences in female age, male age, or sperm DNA fragmentation index (DFI) between the MACS and TESA groups. The blastocyst conversion rate was slightly higher in the TESA group (39%) compared to the MACS group (32%). However, the MACS group had a higher implantation rate (50%) than the TESA group (35%). Miscarriage rates, multiple pregnancy rates, and live birth rates did not show statistically significant differences between the groups. A chi-squared test was conducted to compare categorical variables, and t-tests were done to compare continuous variables. CONCLUSION: In cases with raised sperm DNA fragmentation, sperm selection by MACS or TESA seems to offer comparable reproductive outcomes. There seems no superiority of one intervention over the other in cases with raised sperm DNA fragmentation undergoing assisted reproduction. Both interventions seem to be beneficial for couples seeking assisted reproduction with raised sperm DNA fragmentation.

Oxidative Stress Biomarkers in Male Infertility: Established Methodologies and Future Perspectives.

Male fertility can be affected by oxidative stress (OS), which occurs when an imbalance between the production of reactive oxygen species (ROS) and the body's ability to neutralize them arises. OS can damage cells and influence sperm production. High levels of lipid peroxidation have been linked to reduced sperm motility and decreased fertilization ability. This literature review discusses the most commonly used biomarkers to measure sperm damage caused by ROS, such as the high level of OS in seminal plasma as an indicator of imbalance in antioxidant activity. The investigated biomarkers include 8-hydroxy-2-deoxyguanosine acid (8-OHdG), a marker of DNA damage caused by ROS, and F2 isoprostanoids (8-isoprostanes) produced by lipid peroxidation. Furthermore, this review focuses on recent methodologies including the NGS polymorphisms and differentially expressed gene (DEG) analysis, as well as the epigenetic mechanisms linked to ROS during spermatogenesis along with new methodologies developed to evaluate OS biomarkers. Finally, this review addresses a valuable insight into the mechanisms of male infertility provided by these advances and how they have led to new treatment possibilities. Overall, the use of biomarkers to evaluate OS in male infertility has supplied innovative diagnostic and therapeutic approaches, enhancing our understanding of male infertility mechanisms.

Elucidating the impact of Y chromosome microdeletions and altered gene expression on male fertility in assisted reproduction.

BACKGROUND: Genetic abnormalities like Y chromosome microdeletions are implicated in male infertility. This study investigated the association of azoospermia factor (AZF) region microdeletions with unsuccessful assisted reproductive techniques (ART), including in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). METHODS: This cross-sectional analysis study examined 80 Iranian oligospermic men (mean age 34 years) with prior failed ICSI and IVF cycles (IR.IAU.TNB.REC.1401.041). Semen analysis evaluated quantity/quality parameters based on World Health Organization guidelines. Participants were stratified by sperm DNA fragmentation (SDF) levels into: control (SDF < 15%, n = 20), mild elevation (15% ≤ SDF ≤ 30%, n = 60), and high (SDF > 30%, n = 20). Multiplex PCR mapped AZF microdeletions in the high SDF group. The AZF-associated genes were selected by RNA Seq analysis, and the candidate genes were checked for expression level by real-time PCR. RESULTS: High SDF individuals exhibited poorer semen metrics, including 69% lower sperm concentration (P = 0.04) than those without SDF. Of this subset, 45% (9/20 men) harboured predominately AZF microdeletions. Men with AZF microdeletions showed higher SDF (32% vs 21%, P = 0.02) and altered AZF-associated genes expression. As USP9Y 3-fold, UTY 1.3-fold, and BPY2 1-fold revealed up-regulation, while IQCF1 8-fold, CDY 6.5-fold, DAZ 6-fold, and DDX3Y 1-fold underwent down-regulation. The PAWP gene was also down-regulated (5.7-fold, P = 0.029) in the IVF/ICSI failure group. CONCLUSION: AZF microdeletions significantly impact male infertility and ART outcomes. High SDF individuals exhibited poorer semen metrics, with 45% AZF microdeletions. These microdeletions altered AZF-associated genes expression, affecting fertility mediator PAWP independently. Dual AZF and SDF screening enables personalized management in severe male infertility, potentially explaining IVF/ICSI failures.

Human circBOULE RNAs as potential biomarkers for sperm quality and male infertility.

Reliable molecular biomarkers to predict fertility remain scarce. The current study explored the potential of testis-specific circBOULE RNAs as biomarkers for male infertility and sperm quality. Using RT-PCR and RT-qPCR assays, we identified seven circular RNAs from the human BOULE gene in human sperm. We found that sperm circEx3-6 RNA exhibited a significantly decreased expression in asthenozoospermia while circEx2-6 and circEx2-7 expression decreased in teratozoospermia, compared with the controls. Furthermore, circEx2-6 expression exhibited a negative correlation with sperm DNA Fragmentation Index (DFI), and circEx2-7 levels were correlated with both fertilization and cleavage rates involving assisted reproductive technologies. Further functional analyses in a transgenic fly model lent support for the roles of circBOULE RNAs in sperm development and human fertility. Collectively, our findings support that sperm circBOULE RNAs may serve as diagnostic biomarkers for assessing sperm motility and DNA quality. Hence clinical application and significance of sperm circular RNAs in assisted reproductive technologies warrant further investigation.

Age, sexual abstinence duration, sperm morphology, and motility are predictors of sperm DNA fragmentation.

Purpose: Sperm DNA fragmentation (SDF) has recently received attention as a cause of male infertility. However, SDF cannot be fully assessed using conventional semen parameter evaluations alone. Therefore, the authors aimed to elucidate the relationship between SDF and sperm parameters via computer-assisted sperm analysis (CASA) to improve treatment strategies in reproductive medicine. Methods: This retrospective observational study analyzed the relationship between sperm parameters assessed by CASA and SDF values determined by the TUNEL assay in 359 patients who visited the Mie University Hospital for infertility treatment. The methodology involved semen analyses covering concentration, motility, and morphology, followed by SDF quantification using the flow cytometry. Results: Statistical analysis revealed significant correlations between SDF and various factors, including age, sexual abstinence period, and specific CASA-measured parameters. Notably, lower sperm motility rates and abnormal head dimensions were associated with higher SDF values, indicating that these parameters were predictive of SDF. Conclusions: This study highlights the importance of sperm motility and head morphology as indicators of SDF, suggesting their usefulness in assessing male fertility. These findings demonstrate the efficacy of detailed sperm analysis, potentially increasing the success rate of assisted reproductive technologies by improving sperm selection criteria.

Phase angle at bioelectric impedance analysis is associated with detrimental sperm quality in idiopathic male infertility: a preliminary clinical study.

Background: In 2020, 38% of adults were affected by obesity, while infertility globally affected 1 in 6 people at some stage of their lives.Body mass index (BMI) provides an easy but occasionally inaccurate estimation of body composition. To achieve a more precise assessment, bioelectric impedance analysis serves as a validated tool that administers electrical energy through surface electrodes. Phase angle as a function of the relationship between tissues resistance and reactance, is a trustworthy predictor of body composition and cell membrane integrity. Objectives: We aim to assess whether there is an association between phase angle and seminal parameters, as well as sperm DNA fragmentation percentage. Design: Semen samples of 520 idiopathic infertile patients were analyzed according to 2021 World Health Organization guidelines and evaluated for sperm DNA fragmentation rate. Each participants underwent bioelectric impedance analysis. Results: Median age was 40 years old, median BMI was 26.3 kg/m2, median phase angle was 6.2°. In the logistic regression analysis adjusted for age and total intracorporeal water, phase angle (continuous) was significantly associated with oligozoospermia (odds ratio [OR]:0.4; p<0.01) and sperm morphology (OR: 0.65; p=0.05) and slightly with sperm DNA fragmentation (OR: 0.98; p=0.07). In subgroup analysis, the logistic regression analysis adjusted for the mentioned parameters showed that a phase angle between 6.2 and 7 (°) (OR: 0.63; p=0.02) and >7 (°) (OR: 0.12; p<0.01) were associated with a reduced risk of oligozoospermia compared to values <6.2 (°). Similarly, a phase angle between 6.2 and 7 (°) (OR: 0.57; p< 0.01 and OR: 0.58; p= 0.01) and PA > 7 (°) (OR: 0.12; p= 0.03 and OR: 0.21; p< 0.01) were associated with a reduced risk of lower sperm concentration and lower total sperm count, respectively, compared to a phase angle < 6.2 (°). Conclusion: Our study suggests a negative association between phase angle and detrimental sperm parameters in male idiopathic infertility.

Obesity and male fertility disorders.

Often associated with obesity, male infertility represents a widespread condition that challenges the wellbeing of the couple. In this article, we provide a comprehensive and critical analysis of studies exploring the association between obesity and male reproductive function, to evaluate the frequency of this association, and establish the effects of increased body weight on conventional and biofunctional sperm parameters and infertility. In an attempt to find possible molecular markers of infertility in obese male patients, the numerous mechanisms responsible for infertility in overweight/obese patients are reviewed in depth. These include obesity-related functional hypogonadism, insulin resistance, hyperinsulinemia, chronic inflammation, adipokines, irisin, gut hormones, gut microbiome, and sperm transcriptome. According to meta-analytic evidence, excessive body weight negatively influences male reproductive health. This can occurr through a broad array of molecular mechanisms. Some of these are not yet fully understood and need to be further elucidated in the future. A better understanding of the effects of metabolic disorders on spermatogenesis and sperm fertilizing capacity is very useful for identifying new diagnostic markers and designing therapeutic strategies for better clinical management of male infertility.

Transcriptomic and proteomic features of a mouse model of sperm DNA damage induced by benzo(a)pyrene.

This study replicated a mouse model of sperm DNA damage induced by benzo(a)pyrene (BaP), and the transcriptomic and proteomic features of the model were examined to clarify the pathways related to BaP-induced damage to sperm DNA. Male mice in the BaP group were subjected to BaP at a dosage of 100 mg/kg/d or an equivalent quantity of saline solution in the control group for 60 days. Subsequently, the DNA fragmentation index (DFI) in sperm was assessed using a sperm chromatin structure assay (SCSA). RNA-seq and data-independent acquisition (DIA) were used to identify the mRNA and protein expression patterns in the testis. The sperm DFI significantly increased in the BaP group. Compared to the control group, the BaP group exhibited differential expression of 240 genes (referred to as DEGs) and 616 proteins (referred to as DEPs). These molecules included Aldh1a1, Cyb5r3, Fads1, Oxsm, Rcn3, and Prss45. Pathways in cancer, the PI3K-Akt signaling pathway, metabolic pathways, and the MAPK signaling pathway were the primary areas where these genes showed enrichment. BaP can damage the DNA of sperm and affect metabolism, the PI3K-Akt pathway, and pathways associated with cancer signaling.

Testicular sperm retrieval for intracytoplasmic sperm injection: when to consider it after unsuccessful intracytoplasmic sperm injection with ejaculated sperm?

BACKGROUND: The question of whether patients are more likely to succeed with testicular sperm intracytoplasmic sperm injection (T-ICSI) after unsuccessful ICSI with ejaculated sperm (Ej-ICSI) remains unknown. OBJECTIVE: The study aimed to identify potential predictors of successful T-ICSI in men with idiopathic infertility and oligozoospermia (sperm concentration < 15 × 106/mL, non-azoospermic) who had previously experienced unsuccessful Ej-ICSI. MATERIALS AND METHODS: In total, 154 couples with male partners who had oligozoospermic conditions after two unsuccessful cycles of Ej-ICSI switched to T-ICSI. Before initiating T-ICSI, the sperm DNA fragmentation index (DFI) was assessed in ejaculated specimens. Participants were divided into two groups: group A (live birth (+), n = 60) and group B (live birth (-), n = 94). RESULTS: Fertilization, clinical pregnancy, live births, and miscarriages had rates of 72.7%, 44.2%, 39%, and 5.2%, respectively. The total motile sperm (TMS) count in group A was significantly higher (3.8 ± 1.5 million) than in group B (3 ± 1.6 million; p = 0.002). DFI was significantly higher in group A (24.2 ± 12.3) than in group B (18.1 ± 11; p = 0.001). Hormone levels and oocyte counts showed no statistically significant differences between groups. Multivariate regression analysis revealed that TMS (odds ratio [OR]: 1.46; 95% CI, 1.14-1.87, p = 0.003) and DFI (OR: 1.04; 95% CI, 1.01-1.08, p = 0.009) were found to be significant predictors of live birth outcomes. At a cutoff point of 2.55 (area under the curve [AUC] = 0.65), the optimal sensitivity and specificity values for TMS were 78% and 48%, respectively. At a cutoff point of 25.8 (AUC = 0.65), DFI had a maximum sensitivity of 51.7% and a specificity of 78.7%. CONCLUSIONS: TMS and DFI were found to be significant predictors of live birth outcomes in couples with oligozoospermic male partners undergoing T-ICSI. These findings may help clinicians tailor treatment strategies for this specific patient population.

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.

Reproductive outcomes in patients with high levels of sperm DNA fragmentation using testicular sperm for intracytoplasmic injection: a retrospective analysis.

This study aims to compare the embryological and clinical parameters of intracytoplasmic sperm injection (ICSI) cycles using testicular versus ejaculated sperm in male patients with elevated sperm DNA fragmentation (SDF). A total of 73 ICSI cycles were examined in couples where the male partner exhibited high levels of SDF. ICSI was performed using either ejaculated or testicular sperm. The primary outcomes were rates of blastocyst formation, high-quality embryo development, and clinical pregnancy. The DNA fragmentation index (DFI) for testicular sperm (16.81 ± 17.51) was significantly lower than that of ejaculated sperm (56.96 ± 17.56). While the blastocyst formation rate was significantly higher in the testicular sperm group compared to the ejaculated sperm group, no statistically significant differences were noted in fertilization rate (72.15% vs. 77.23%), rate of high-quality embryo formation (47.17% vs. 46.53%), clinical pregnancy (50% vs. 56.52%), Cumulative pregnancy (70.2% vs. 55.6%), or live birth rate (43.75% vs.43.48%). Testicular spermatozoa have no additional advantage over ejaculated spermatozoa except for blastocyst quality in patients with high SDF, the use of testicular spermatozoa for the first ICSI cycle in male infertility patients with high SDF should be undertaken after much consideration at present.

Elevated sperm DNA fragmentation is correlated with an increased chromosomal aneuploidy rate of miscarried conceptus in women of advanced age undergoing fresh embryo transfer cycle.

Background: Male sperm DNA fragmentation (SDF) may be associated with assisted reproductive technology (ART) outcomes, but the impact of SDF on the occurrence of aneuploid-related miscarriage remains controversial. Methods: Genome-wide single-nucleotide polymorphism-based chromosomal microarray analysis was performed on 495 miscarried chorionic villus samples undergone IVF/ICSI treatment from the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University. SDF was assessed using sperm chromatin structure assay. Patients were divided into four groups according to embryo transfer cycle type and maternal age, and the correlation between SDF and chromosome aberration was analyzed. A receiver operating characteristic (ROC) curve was utilized to find the optimal threshold. Results: Total chromosomal aneuploidy rate was 54.95%, and trisomy was the most common abnormality (71.32%). The chromosomally abnormal group had higher SDF than the normal group (11.42% [6.82%, 16.54%] vs. 12.95% [9.61%, 20.58%], P = 0.032). After grouping, elevated SDF was significantly correlated with an increasing chromosome aneuploidy rate only in women of advanced age who underwent fresh embryo transfer (adjusted odds ratio:1.14 [1.00-1.29], adjusted-P = 0.045). The receiver operating characteristic curve showed that SDF can predict the occurrence of chromosomal abnormality of miscarried conceptus in this group ((area under the curve = 0.76 [0.60-0.91], P = 0.005), and 8.5% was the optimum threshold. When SDF was ≥ 8.5%, the risk of such patients increased by 5.76 times (adjusted odds ratio: 6.76 [1.20-37.99], adjusted-P = 0.030). Conclusion: For women of advanced maternal age undergoing fresh embryo transfer, older oocytes fertilized using sperm with high SDF in IVF/ICSI treatment might increase the risk of chromosomal abnormality in miscarried conceptus.

Iterative oxidation by TET1 is required for reprogramming of imprinting control regions and patterning of mouse sperm hypomethylated regions.

Ten-eleven translocation (TET) enzymes iteratively oxidize 5-methylcytosine (5mC) to generate 5-hydroxymethylcytosine (5hmC), 5-formylcytosine, and 5-carboxylcytosine to facilitate active genome demethylation. Whether these bases are required to promote replication-coupled dilution or activate base excision repair during mammalian germline reprogramming remains unresolved due to the inability to decouple TET activities. Here, we generated two mouse lines expressing catalytically inactive TET1 (Tet1-HxD) and TET1 that stalls oxidation at 5hmC (Tet1-V). Tet1 knockout and catalytic mutant primordial germ cells (PGCs) fail to erase methylation at select imprinting control regions and promoters of meiosis-associated genes, validating the requirement for the iterative oxidation of 5mC for complete germline reprogramming. TET1V and TET1HxD rescue most hypermethylation of Tet1-/- sperm, suggesting the role of TET1 beyond its oxidative capability. We additionally identify a broader class of hypermethylated regions in Tet1 mutant mouse sperm that depend on TET oxidation for reprogramming. Our study demonstrates the link between TET1-mediated germline reprogramming and sperm methylome patterning.

Investigation of sperm hsa-mir-145-5p and MLH1 expressions, seminal oxidative stress and sperm DNA fragmentation in varicocele.

BACKGROUND: Mechanisms by which varicocele causes infertility are not clear and few studies have reported that some miRNAs show expression alterations in men with varicocele. Recently, sperm promoter methylation of MLH1 has been shown to be higher in men diagnosed with varicocele. This study aimed to assess the potential effects of miR-145, which was determined to target MLH1 mRNA in silico on sperm quality and function in varicocele. METHODS: Sperm miR-145 and MLH1 expressions of six infertile men with varicocele (Group 1), nine idiopathic infertile men (Group 2), and nine fertile men (control group) were analyzed by quantitative PCR. Sperm DNA fragmentation was evaluated by TUNEL and the levels of seminal oxidative damage and total antioxidant capacity were analyzed by ELISA. RESULTS: Our results have shown that sperm expression of miR-145 was decreased in Group 1 compared to Group 2 (P = 0.029). MLH1 expression was significantly higher in Group 2 than the controls (P = 0.048). Total antioxidant level and sperm DNA fragmentations of Group 1 and Group 2 were decreased (P = 0.001 and P = 0.011, respectively). Total antioxidant capacity was positively correlated with sperm concentration (ρ = 0.475, P = 0.019), total sperm count (ρ = 0.427, P = 0.037), motility (ρ = 0.716, P < 0.0001) and normal morphological forms (ρ = 0.613, P = 0.001) and negatively correlated with the seminal oxidative damage (ρ=-0.829, P = 0.042) in varicocele patients. CONCLUSION: This is the first study investigating the expressions of sperm miR-145 and MLH1 in varicocele patients. Further studies are needed to clarify the potential effect of miR-145 on male fertility.