Papillomavirus infection and male infertility: A systematic review and meta-analysis.

Background and Aims: Increasing attention is being paid to the role of human papillomavirus (HPV) in men and specifically reproduction. Growing evidence suggests an association between HPV infection with many adverse effects including the impairment of semen parameters, the increase of blastocyst apoptosis, the reduction of endometrial implantation of trophoblastic cells, as well as the increase rate of miscarriages and spontaneous preterm birth. Methods: We systematically searched PubMed/MEDLINE, Scopus, Embase, Web of Science, CINHAL, PsycINFO, and ERIC from inception to 2nd of July 2024, for studies that investigated the association between HPV infection with sperm parameters and fertility outcomes. The meta-analysis was conducted on mean data and standard deviations. Results: We included 25 studies with a total of 6942 patients. Sperm morphology was lower in HPV positive groups versus HPV negative control groups (SMD = -0.52 95% CI -0.84; -0.21; p = 0.001). Sperm motility was also significantly lower in HPV positive groups when compared to HPV negative controls (SMD = -0.82 95% CI -1.07; -0.57; p = <0.001). Sperm volume, concentration, and pH were not significantly different between the two groups. The other 15 studies included in the systematic review for which it was not possible to conduct a meta-analysis showed strong associations between HPV infection and impairment of sperm parameters, reduced couple fertility and increased risk of pregnancy loss. Conclusions: The current evidence highlights the link between HPV infection and sperm parameters, male fertility and reproductive outcomes, which has the potential to lead to a decreased couple fertility, increased risk of pregnancy loss, re-infection and increased treatment costs.

Longitudinal trends and correlation between autism spectrum disorder prevalence and sperm quality parameters (2000-2024): a comprehensive statistical analysis.

Introduction: Over the past few decades, there has been growing concern about the concurrent trends of increasing Autism Spectrum Disorder (ASD) prevalence and declining sperm quality. These trends represent significant public health challenges that warrant thorough investigation of their underlying causes and implications. Objectives: The primary objectives of this study are to analyze trends in ASD prevalence and sperm quality parameters from 2000 to 2024, assess the statistical significance and effect size of these trends, explore potential correlations between ASD prevalence and sperm quality parameters, and identify significant predictors among sperm quality parameters that influence ASD prevalence. Methods: This study employed a longitudinal approach using multiple regression, time series analysis, ANOVA, Principal Component Analysis (PCA), hierarchical clustering, logistic regression, and cross-correlation analysis. Data on ASD prevalence were sourced from the CDC Autism and Developmental Disabilities Monitoring Network, while sperm quality data were collected from various published studies. Results: The findings reveal significant negative associations between ASD prevalence and sperm quality parameters such as sperm concentration and motility, suggesting that better sperm quality is linked to lower ASD rates. Conversely, parameters like sperm DNA fragmentation (SDF), volume of ejaculate, pH level, and semen viscosity show positive associations with ASD prevalence, indicating higher values in these parameters correlate with higher ASD rates. Conclusion: The study highlights the importance of maintaining reproductive health to potentially mitigate ASD risk and calls for further research to elucidate the underlying mechanisms driving these trends. These findings support the hypothesis that reproductive health factors play a crucial role in ASD etiology and suggest potential biological markers for assessing ASD risk.

Tofacitinib Does Not Impair Sperm Quality in Men With Ulcerative Colitis.

We demonstrate that tofacitinib does not adversely affect semen quality or sex hormones in male patients. These first postmarketing data for tofacitinib and semen quality are reassuring. Our study raises no safety concerns, though larger studies are needed to confirm our findings.

The characteristics of frozen-thawed rooster sperm using various intracellular cryoprotectants.

Cryopreservation of rooster semen is essential for conserving genetic resources, genetic improvement, and increasing productivity. However, the nature of avian sperm presents a global issue in ensuring superior frozen semen for artificial insemination. Thus, the present study aimed to evaluate the impact of using dimethylacetamide (DMA), dimethyl sulfoxide (DMSO), and ethylene glycol (EG) as cryoprotectants on post-thawed sperm motility, quality, antioxidant indicators, and fertilizing capacity. Twice a week, fresh semen ejaculates were collected from 15 adult roosters and immediately evaluated to constitute a pool from clean and qualified samples. The pooled semen was further diluted at a ratio of 1:2 (v/v) with an extender and then subjected to a freezing protocol in a liquid nitrogen vapor after adding a cryoprotectant solution containing 6% of either DMA, DMSO, or EG, respectively. After thawing, characteristics of sperm motion, quality, antioxidants, and fertilizing ability were evaluated and compared to fresh and cooled semen as controls. The results demonstrated that semen cooling negatively affected some parameters of sperm motility, quality, antioxidant biomarkers, and fertility. In comparison to the DMSO and EG groups, employing DMA considerably (P < 0.05) raised the percentages of sperm progressive motility, viability, plasma membrane intactness, and DNA integrity. The DMA group showed a significant increase in the catalase and glutathione reduced antioxidant enzyme activity and a reduction in nitric oxide and lipid peroxidation. After artificial insemination, the DMA and DMSO groups exhibited considerably (P < 0.05) better rates of hatchability and fertility than the EG group. It is concluded that freezing extenders containing 6% DMA is better than DMSO or EG to improve the post thaw semen quality and fertility in chickens.

Whole tomato lipidic extract improved sperm quality in obese rats induced by a high-carbohydrate diet.

BACKGROUND: Obesity represents a risk in the development of metabolic and oxidative stress (OS), as well as in male infertility. There is still no pharmacological treatment for obesity-induced male infertility, but the use of natural antioxidants has been proposed as a treatment. OBJECTIVE: The aim of this work is to evaluate the effect of a whole tomato lipid extract on rats that decreased their fertility and spermatogenesis after being induced obese with a high carbohydrate diet. MATERIALS AND METHODS: One hundred fourteen male Wistar rats of 12 weeks of age were used. Two groups were randomly formed non-obese control group (C, n = 54) and obese group (Ob, n = 54) that received 30% w/v sucrose solution for 3 months. Subsequently, the C and Ob group were divided into two groups: vehicle (C-Vh and Ob-Vh) that received corn oil as vehicle and tomato lipid extract (C-Ex and Ob-Ex) that received whole tomato lipid extract. The groups that received a hypercaloric diet had a gain in visceral and retroperitoneal adipose tissue, an increase in total cholesterol and triglyceride levels, increased OS in the testis, and lesions in testicular histology, as well as a reduction in testicular size and sperm quality parameters (motility, viability, and concentration). RESULTS: Treatment with whole tomato lipid extract significantly decreased the weight of gonadal adipose tissue and OS, maintained testicular size, showed a significant increase in sperm quality parameters and improved histology of seminiferous tubules. CONCLUSIONS: These results demonstrate a greater therapeutic and beneficial effect of the tomato lipid extract on sperm quality parameters in obese rats and therefore on fertility.

Metagenomic identification of bull semen microbiota in different seasons.

A seasonal effect on sperm quality parameters was observed previously. Although identification of the bull semen microbiota by 16S rRNA sequencing was performed previously, it has not been carried out in commercial semen samples from different seasons, and its connection with sperm quality parameters has not been evaluated yet. The objectives in this study were; (i) to evaluate diversity of bull semen microbiota and sperm quality parameters in different seasons, and (ii) to find if specific bacteria were associated with seasonal differences in specific sperm quality parameters. Bull semen microbiota was identified in 54 commercial bull semen samples from 3 seasons (winter, spring, summer). Sperm quality was analysed by Computer Assisted Sperm Analyses (CASA) and Flow Cytometry (FC). From 28 phyla in all samples, six phyla were identified in samples from all seasons, with observed seasonal differences in their distribution. At genus level, 388 genera were identified, of which 22 genera had a relative abundance over 1 % and showed seasonal differences in bacterial diversity, and 9 bacteria genera were present in all seasons. Differences between spring and summer (P < 0.05) were observed for live hydrogen peroxide positive sperm cells. A trend towards significance (0.10 > P > 0.05) was observed for some CASA kinematics (VCL and LIN) and FC parameters (High respiratory activity, and live hydrogen peroxide positive sperm cells) between seasons. Nevertheless, associations between sperm quality parameters and specific bacteria were observed in spring.

Effect of Mitoquinone on sperm quality of cryopreserved stallion semen.

This study aimed to investigate the effect of mitochondria-targeted antioxidants (Mitoquinone, MitoQ) on the quality of frozen-thawed stallion semen. Semen samples collected from three fertile stallions aged 10 - 13 years, were filtered, centrifuged in a skimmed milk-based extender, and diluted to a final concentration of 50 × 106 sperm/mL in freezing medium. Diluted semen was divided into five experimental groups supplemented with MitoQ at concentrations of 0 (control), 25, 50, 100, and 200 nM and then subjected to freezing after cooling and equilibration. After thawing, semen was evaluated for motility and kinetics at different time points. Sperm viability, plasma membrane, acrosome, DNA integrity, mitochondrial membrane potential, apoptosis, and intracellular reactive oxygen species (ROS) concentrations were evaluated. The results revealed that MitoQ at concentrations of 25, 50, and 100 nM improved (P< 0.01) the total sperm motility after 30 minutes of incubation. In addition, 25 nM MitoQ improved the sperm amplitude of lateral head displacement values (P< 0.01) after 30 minutes of incubation. Conversely, negative effects on sperm motility, kinetics, and viability were observed with the highest tested concentration of MitoQ (200 nM). The various concentrations of MitoQ did not affect the plasma membrane, acrosome, and DNA integrity, or the mitochondrial membrane potential and intracellular ROS concentrations. In conclusion, supplementation of MitoQ during cryopreservation, had a mild positive effect on sperm motility and kinetics especially at a concentration of 25 nM, while the highest concentration (200nM) has a detrimental effect on motility and viability parameters of frozen-thawed stallion sperm.

Male infertility risk and plasma lipidome: a Mendelian randomization study.

Background: In recent years, the decline in sperm quality in men has become a global trend. There is a close relationship between sperm quality and pregnancy outcome. There is a large body of literature supporting the role of plasma lipidome in male infertility, while the complex mechanisms between them and male infertility are still less clear. Systematic study of the causal relationship between plasma lipidome and MI can help to provide new therapeutic ideas and targets for male infertility. Methods: In this study, we used a two-sample Mendelian randomization analysis based on Genome-wide association studies pooled data of 179 causal relationships between plasma lipidome and male infertility. We used employed the inverse variance weighted method as the main analysis to assess causality between exposure and outcome, in addition to MR-Egger, Weighted median as complementary methods, and tests for multiplicity and heterogeneity. Results: We identified 13 plasma lipidome comprising 4 types of plasma lipidome that were associated with male infertility. Among these, 9 plasma lipidome were found to be protective factors, while 4 were risk factors. Notably, the largest proportion of these plasma lipidome were triglyceride types, with Sphingomyelin (d40:1) exhibiting the strongest association with male infertility. Conclusion: These findings contribute to the current better understanding of male infertility and provide new perspectives on the underlying etiology of male infertility as well as prevention and treatment strategies. In addition, clinical trial validation is needed to assess the potential of these plasma lipidome as biomarkers.

The prediction of semen quality based on lifestyle behaviours by the machine learning based models.

PURPOSE: To find the machine learning (ML) method that has the highest accuracy in predicting the semen quality of men based on basic questionnaire data about lifestyle behavior. METHODS: The medical records of men whose semen was analyzed for any reason were collected. Those who had data about their lifestyle behaviors were included in the study. All semen analyses of the men included were evaluated according to the WHO 2021 guideline. All semen analyses were categorized as normozoospermia, oligozoospermia, teratozoospermia, and asthenozoospermia. The Extra Trees Classifier, Average (AVG) Blender, Light Gradient Boosting Machine (LGBM) Classifier, eXtreme Gradient Boosting (XGB) Classifier, Logistic Regression, and Random Forest Classifier techniques were used as ML algorithms. RESULTS: Seven hundred thirty-four men who met the inclusion criteria and had data about lifestyle behavior were included in the study. 356 men (48.5%) had abnormal semen results, 204 (27.7%) showed the presence of oligozoospermia, 193 (26.2%) asthenozoospermia, and 265 (36.1%) teratozoospermia according to the WHO 2021. The AVG Blender model had the highest accuracy and AUC for predicting normozoospermia and teratozoospermia. The Extra Trees Classifier and Random Forest Classifier models achieved the best performance for predicting oligozoospermia and asthenozoospermia, respectively. CONCLUSION: The ML models have the potential to predict semen quality based on lifestyles.

PRSS50-mediated inhibition of MKP3/ERK signaling is crucial for meiotic progression and sperm quality.

Serine protease 50 (PRSS50/TSP50) is highly expressed in spermatocytes. Our study investigated its role in testicular development and spermatogenesis. Initially, PRSS50 knockdown was observed to impair DNA synthesis in spermatocytes. To further explore this, we generated PRSS50 knockout ( Prss50 -/- ) mice ( Mus musculus), which exhibited abnormal spermatid nuclear compression and reduced male fertility. Furthermore, dysplastic seminiferous tubules and decreased sex hormones were observed in 4-week-old Prss50 -/- mice, accompanied by meiotic progression defects and increased apoptosis of spermatogenic cells. Mechanistic analysis indicated that PRSS50 deletion resulted in increased phosphorylation of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) and elevated levels of MAP kinase phosphatase 3 (MKP3), a specific ERK antagonist, potentially accounting for testicular dysplasia in adolescent Prss50 -/- mice. Taken together, these findings suggest that PRSS50 plays an important role in testicular development and spermatogenesis, with the MKP3/ERK signaling pathway playing a significant role in this process.

Effects of antioxidant Bis-carboxyethyl germanium sesquioxide added to bovine semen cryopreservation medium on in vitro assessed morphofunctional sperm parameters.

This study investigated the impact of various Ge132 (Bis-carboxyethyl germanium sesquioxide) concentrations on frozen bovine semen. Ejaculates from three bulls were pooled and divided into six groups, each one with different Ge132 concentrations (0, 500, and 1000 µg/mL) and each group was incubated in different conditions (33°C for 30 min (D: D0, D500, and D1000), and the other was immediately cooled to 4°C (R: R0-control; R500 and R1000)). Thawed semen was evaluated for sperm characteristics by CASA and flow cytometer. Results showed better motility in the immediate cooling group without Ge132 compared with high Ge132 concentrations. Values for total motility dropped after 5 and 60 min in groups with high Ge132 levels and some control groups. Linearity increased with 1000 µg/mL Ge132, while straightness differed between moments in multiple groups. Membrane integrity was higher in a control group and certain Ge132 groups. Lower O2 - generation occurred without Ge132. After oxidative stress induction, lipid peroxidation intensity increased with arachidonic acid, but D1000 had lower peroxidation than R0. Overall, Ge132 appears to have provided protection against PLM when subjected to oxidative stress, since even at high concentrations it maintained sperm metabolism.

Fluorene-9-bisphenol impaired male fertility through disrupting the testicular function and local microenvironment.

Past studies have observed that BHPF induces multi-organ toxicity, however, whether it induces damage to male reproductive system and the specific mechanism remains unclear. In the present study, male mice were given 0, 2, 10 or 50 mg/kg/day of BHPF by gavage for 35 days to observe its effect on reproductive organ and sperm quality. The results indicated that BHPF decreased sperm count and sperm motility in a dose-dependent manner. Besides, our results demonstrated that BHPF triggered the proliferation inhibition and cell death of germ cells in vivo and in vitro. Also, BHPF reduced the expression of function markers for germ cells, Sertoli cells, and Leydig cells, indicating its damage to function of testis cells. Simultaneously, testicular microenvironment was found to be altered by BHPF, as presented with declined testosterone level and decreased expression of local microenvironment regulators. Overall, our findings indicated the detrimental effects of BHPF on male reproductive function in mice, suggesting testicular function and local microenvironment disturbance as mechanism underlying testicular damage.

The effect of hydroxy-selenomethionine on the productive and reproductive performance of old broiler breeders.

BACKGROUND: Selenium (Se) is a rare essential element that plays a vital role in the health and performance of animals. By interfering in the production of antioxidant enzymes such as glutathione peroxidase, thioredoxin reductase and methionine sulfoxide, Se plays a role in reducing the effects of oxidative stress and animal performance. OBJECTIVES: This study aimed to investigate the effect of hydroxy-selenomethionine (OH-SeMet) in the diet of broiler breeder and old broiler breeder roosters on productive performance, reproduction and sperm quality parameters. METHODS: For this purpose, 260 broiler breeders of the Ross 308 strain were used in a completely randomized design with four treatments and five replications (13 hens and one rooster in each replication). Experimental treatments included: (1) a basal diet without OH-SeMet (T1:control), (2) a broiler breeder diet without OH-SeMet and a rooster diet containing 0.1 mg/kg OH-SeMet (T2), (3) broiler breeder diet containing 0.1 mg/kg OH-SeMet and rooster diet without OH-SeMet (T3) and (4) broiler breeder and rooster diet contained 0.1 mg/kg OH-SeMet (T4). RESULTS: The results showed that T3 and T4 treatments improved egg production, egg weight, egg mass and feed conversion ratio (FCR) compared to the control treatment (p < 0.05). The fertility and hatchability percentages of T4 and T2 treatments increased compared to T1 and T3 treatments (p < 0.05). The rate of embryonic losses in T1 was higher than in other treatments. However, grade one chickens were higher in T4 than in other treatments (p < 0.05). Total motility and viability of sperms were significantly higher in T2 and T4 treatments than in T1 and T3 treatments. The sperm abnormality percentage and sperm MDA concentration decreased in T2 and T4 treatments. CONCLUSIONS: Therefore, using OH-SeMet may be a practical approach to help old broiler breeders' production and reproduction performance.

Sperm-borne miR-34c-5p and miR-191-3p as markers for sperm motility and embryo developmental competence.

BACKGROUND: Sperm-borne microRNAs play a pivotal role in influencing essential cellular processes during fertilization, impacting the quality of embryo development. Dysregulated microRNA profiles have been associated with compromised embryonic development and increased incidences of pregnancy loss. OBJECTIVE: This study aimed to investigate the potential associations between the abundance of miR-34c-5p and miR-191-3p in human spermatozoa with sperm quality, as well as with embryo quality and metabolic performance during in vitro development. MATERIALS AND METHODS: Thirteen couples who underwent a total of 13 cycles participated in this study. The sperm quality was assessed using conventional methods following World Health Organization guidelines. Quantitative polymerase chain reaction was employed to measure microRNA abundance in spermatozoa. Embryos were categorized as good, lagging, or bad based on morphokinetic evaluation. Evaluation of embryo metabolic performance involved tracking changes in specific metabolites within the cultured media using nuclear magnetic resonance spectroscopy. Statistical analysis was conducted to explore the correlation between microRNA abundance in human spermatozoa and all other collected data. RESULTS: Our findings revealed a negative correlation between the abundance of miR-34c-5p (but not miR-191-3p) and total sperm motility, potentially mediated by the modulation of key signaling pathways. Additionally, higher levels of miR-34c-5p in spermatozoa were strongly associated with the consumption or release of key metabolites by developing embryos, particularly those linked with lipid and glucose metabolism, suggesting enhanced metabolic performance, while miR-191-3p was mostly associated with glucose consumption. Concurrently, only miR-34c-5p content in spermatozoa correlated with higher embryo quality. DISCUSSION AND CONCLUSION: This study provides evidence suggesting that the abundance of miR-34c-5p in spermatozoa is correlated not only with total sperm motility but also with markers of embryo developmental competence, highlighting the potential significance of this sperm microRNA content as a biomarker in assisted reproduction.

Sperm collection and characteristics analysis of the critically endangered Chinese pangolin (Manis pentadactyla).

The Chinese pangolin (Manis pentadactyla) is a critically endangered species. However, there is a paucity of research on the male reproductive gamete biology of this species. The present study was the first to systematically analyse the sperm characterization of the Chinese pangolin, including semen collection, sperm morphometry and ultrastructure. The semen of five male Chinese pangolins was successfully collected using the electroejaculation method. CASA (computer-assisted sperm analysis) was used to assess semen quality and take images for sperm morphometric analysis. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for sperm ultrastructure observation. The results showed that the semen of the Chinese pangolin was yellow to pale yellow in colour, viscous, with a fishy odour, and a slightly alkaline pH of between 7.7 and 7.9. The head defects were the main sperm defects; there were 13 kinds of head defects counted in this study. The total sperm length, head length, head width and tail length were 67.62 ± 0.21 µm, 10.47 ± 0.06 µm, 1.33 ± 0.006 µm and 57.16 ± 0.20 µm, respectively. SEM observed that the spermatozoa had a rod-shaped head with a distinct apical ridge, which was different from most mammals and similar to that in avians and reptiles. Interestingly, TEM found that the acrosome membrane of the Chinese pangolin had a double membrane structure rather than a multiple bi-lamellar membrane structure as reported by the previous study. Collectively, this study contributes to the development of artificial breeding efforts and assisted reproductive techniques for the Chinese pangolin, as well as providing technical support for research on germplasm conservation of this species.

Evaluation of sperm quality and male fertility: The use of molecular markers in boar sperm and seminal plasma.

In pig production, the optimization of artificial insemination (AI) efficiency significantly relies on the accurate assessment of semen quality and fertility of boars. Traditional methods such as conventional seminogram techniques, although long-standing, exhibit limited sensitivity in predicting boar fertility, warranting the exploration of novel molecular markers. This review synthesizes the current knowledge on the utilization of molecular markers for semen quality evaluation and male fertility prediction in boars, providing an in-depth examination of molecular markers in this context. Specifically, the present work delves into the potential of OMICs technologies, encompassing genetic and genomic approaches, transcriptomics, proteomics, and metabolomics. A diverse array of molecular markers, including genomic regions associated with sperm quality and male fertility, chromatin integrity, mitochondrial DNA content, mRNA and non-coding RNA signatures, as well as proteins and metabolites in sperm and seminal plasma, are identified as promising molecular markers for fertility prediction in boars. Furthermore, the need of validating biomarkers and their practical implementation in AI centres is here emphasized. Addressing these considerations and integrating molecular markers within the swine breeding field holds the potential to enhance reproductive management practices and optimize productivity in boar breeding programs. This integration can significantly improve overall efficiency within the pig breeding industry.

Dietary supplementation with ginseng extract enhances testicular function, semen preservation, and fertility rate of mature and aging Thai native roosters.

The decrease in fertility in aging roosters is related to the reduced quality of ejaculated sperm. This study aimed to investigate the effect of dietary supplementation with ginseng extract at various concentrations (0-150 mg/kg) on testicular function, semen preservation, and fertility at different stages of sexual maturity (mature and aging roosters) in Thai native roosters. Pradu Hang Dum roosters at 32 (mature; n = 24) and 75 (aging; n = 24) weeks of age were fed diets with non-supplemented or supplemented ginseng extracts (50, 100, and 150 mg/kg) until the end of the experiment. In experiment 1, fresh semen samples were examined for the quality parameters of semen volume, sperm concentration, sperm motility, sperm viability, lipid peroxidation, and enzymatic activities. In experiment 2, semen was preserved at 5 °C for up to 48 h, and the semen quality and fertility potential were determined. In experiment 3, testicular function and testosterone concentrations were evaluated. The results showed that ginseng extract supplementation in the diets of both mature and aging roosters at 50 and 100 mg/kg improved fresh semen quality (P < 0.05). A decrease in malondialdehyde levels in fresh semen was observed with increasing enzyme activities. In mature roosters, the progressive motility of cold-stored semen and fertility rates were higher in the G50 and G100 groups compared to the control and G150 groups after 24 h of storage (P < 0.05). In aging roosters, the highest significant differences in progressive motility, viability, and fertility rates were observed in the G50 and G100 groups at all storage times (P < 0.01). These improvements might be attributed to good testicular function in spermatogenesis, as revealed by the results of histological examination and testosterone concentrations. However, higher doses of ginseng extract supplementation negatively affected sperm quality. In summary, the recommended dose of ginseng extract supplementation in diets is 50 mg/kg. Fertility results indicated that insemination with semen preserved for 24 h was satisfactory in both mature and aging roosters.

Exposure to ambient ozone and sperm quality among adult men in China.

BACKGROUND: Limited evidence exists regarding the association between ozone exposure and adverse sperm quality. We aimed to assess the association between ozone exposure and sperm quality, and identify susceptible exposure windows. METHODS: We recruited 32,541 men aged between 22 and 65 years old attending an infertility clinic in Wuhan, Hubei Province, China from 2014 to 2020. Ozone data were obtained from a satellite-based spatiotemporal model. Generalized linear models were used to estimate the association between ozone exposure and sperm quality parameters, including sperm concentration, sperm count, sperm total motility, and sperm progressive motility during the entire stage of sperm development (0-90 days before ejaculation) and three crucial stages (0-9 days, 10-14 days and 70-90 days before ejaculation). Stratified analyses were performed to evaluate whether associations varied by age, body mass index, and education levels. RESULTS: The final analysis included 27,854 adult men. A 10 µg/m3 increase in ozone concentrations during the entire stage of sperm development was associated with a -4.17 % (95 % CI: -4.78 %, -3.57 %) decrease in sperm concentration, -6.54 % (95 % CI: -8.03 %, -5.60 %) decrease in sperm count, -0.50 % (95 % CI: -0.66 %, -0.34 %) decrease in sperm total motility, and -0.07 % (95 % CI: -0.22 %, 0.09 %) decrease in sperm progressive motility. The associations were stronger during 70-90 days before ejaculation and among men with middle school and lower education for sperm concentration. CONCLUSIONS: Ozone exposure was associated with decreased sperm quality among Chinese adult men attending an infertility clinic. These results suggest that ozone may be a risk factor contributing to decreased sperm quality in Chinese men.

Poor Sperm Chromatin Condensation Is Associated with Cryopreservation-Induced DNA Fragmentation and Cell Death in Human Spermatozoa.

Background/Objectives: Semen cryopreservation is routinely performed in fertility clinics for a variety of reasons, including fertility preservation and storage of donor sperm, yet the freeze-thaw process leads to cellular damage via ice crystal formation, osmotic shock, and supraphysiological levels of oxidative stress. Sperm resistance to damage during the freeze-thaw process varies widely, yet the intrinsic factors associated with sperm cryotolerance are largely unknown. The study aimed to investigate whether poor chromatin condensation renders sperm vulnerable to DNA fragmentation and cell death induced by the freeze-thaw process. Methods: Participants (n = 51) from the general community who met the inclusion criteria collected a semen sample after 3-8 days of abstinence. Neat semen samples underwent traditional semen analysis, aniline blue (AB)-eosin staining for chromatin condensation, the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay for DNA fragmentation, and the Annexin V assay for apoptosis/necrosis, prior to being cryopreserved using the liquid nitrogen vapour method and stored at -196 °C. Stored samples were later thawed at room temperature and processed using density gradient centrifugation. Motile sperm concentration, DNA fragmentation and apoptosis/necrosis were analysed in post-thaw samples. Results: As indicated by a significant interaction effect in linear mixed models, an increased proportion of AB-positive sperm in the pre-freeze sample exacerbated the adverse effect of freezing on sperm DNA fragmentation (p = 0.004), late apoptosis (p = 0.007), and necrosis (p = 0.007). AB-staining was positively correlated with all three parameters in the post-thaw sample (all rs ≥ 0.424, all p < 0.01) and remained significant after adjusting for neat sperm concentration (all partial rs ≥ 0.493, all p < 0.01). Similarly, AB-staining was significantly correlated with the percentage point change in sperm DNA fragmentation (rs = 0.366, p = 0.014) and necrosis (rs = 0.403, p = 0.009), both of which remained significant after adjusting for neat sperm concentration (both partial rs ≥ 0.404, both p < 0.01), and borderline significantly correlated with percentage point change in late apoptosis (rs = 0.307, p = 0.051). Conclusions: Sperm with poorly condensed chromatin may be more susceptible to cellular damage during the freeze-thaw process, independent of pre-freeze sperm concentration. These findings may help to explain the intrinsic variation in sperm resistance to cryodamage within and between individuals that is poorly understood.

Vigor King mitigates spermatogenic disorders caused by environmental estrogen zearalenone exposure.

Zearalenone (ZEN) has been shown to cause reproductive damage by inducing oxidative stress. Astaxanthin and L-carnitine are widely used to alleviate oxidative stress and promote sperm maturation. However, it remains uncertain whether they are effective in mitigating spermatogenesis disorders induced by ZEN. This study aimed to investigate the therapeutic efficacy and potential mechanisms of Vigor King (Vig), a compound preparation primarily consisting of astaxanthin and L-carnitine, in alleviating ZEN-induced spermatogenesis disorders. In the experiment, mice received continuous oral gavage of ZEN (80 µg/kg) for 35 days, accompanied by a rescue strategy with Vig (200 mg/kg). The results showed that Vig effectively reduced the negative impact on semen quality and improved the structural and functional abnormalities of the seminiferous epithelium caused by ZEN. Additionally, the accumulation of reactive oxygen species (ROS), DNA double-strand breaks, apoptosis, and autophagy abnormalities were all significantly ameliorated. Intriguingly, the GSK3ß-dependent BTRC-NRF2 signaling pathway was found to play an important role in this process. Furthermore, testing of offspring indicated that Vig could extend its protective effects to the next generation, effectively combating the transgenerational toxic effects of ZEN. In summary, our research suggests that Vig supplementation holds considerable promise in alleviating spermatogenesis disorders induced by zearalenone.