Do sperm and lubricants gel well with each other? A systematic review

Vaginal lubricants are commonly used to aid sexual pleasure and/or to help combat vaginal dryness and dyspareunia. Several studies have reported their impact on sperm function, however there are no published guidelines to help healthcare professionals and couples select a vaginal lubricant that is 'sperm-safe'. To address this, we conducted a literature search using both PubMed and Scopus to identify and appraise manuscripts that reported the impact of lubricants on sperm function. We did not restrict the literature search by year of publication, and we only included manuscripts that looked at the impact of vaginal lubricants on human sperm. The quality of the eligible studies was assessed using the Björndahl et al., (2016) checklist for semen analysis, as most of the studies reported the findings of a basic semen analysis. A total of 24 articles were eligible for analysis with a total of 35 vaginal lubricants (that were available to buy over the counter) being included, 2 of which studied the effect of vaginal lubricants on sperm function in vivo, and 22 being conducted in vitro. KY Jelly, PreSeed and Astroglide were most studied, with most manuscripts focussing on their impact on sperm motility. A paucity of data on most lubricants combined with methodological variations between studies and limited/no reporting on pregnancy outcomes means greater efforts are required before an evidence-based guideline can be published.

Correlation between standard sperm parameters and sperm DNA fragmentation from 11,339 samples

Conventional semen parameters have long been considered fundamental in male fertility analyses. However, doubts have been raised regarding the clinical utility of the assessment of spermatozoa (sperm) DNA damage. In this retrospective study, we investigated the potential correlation between conventional semen parameters and semen DNA fragmentation (SDF) assessed as sperm DNA damage, in 11,339 semen samples collected between January 2019 and June 2022. We observed significant negative correlations between the DNA fragmentation index (DFI) and sperm viability (correlation coefficient [r] = -0.514) as well as progressive sperm motility (r = -0.512, p < 0.05). Samples were categorized into three groups according to DFI levels (Groups A, B, and C: ≤15%, 15 < DFI ≤30%, and >30%, respectively). Furthermore, the percentage of semen samples with normal sperm conventional parameters in Groups A, B, and C was 76.7% (4369/5697), 61.4% (2351/3827), and 39.7% (721/1815), respectively. Moreover, according to the reference values of conventional sperm parameters, the samples were divided into Groups F, G, and H with all normal, only one abnormal, and > two abnormal parameters, respectively. In addition, the proportions of samples with abnormal DFI values (>30) in Groups F, G, and H were 9.7% (721/7441), 23.1% (618/2676), and 39.0% (476/1222), respectively. Multivariate logistic regression models demonstrated that sperm vitality, progressive sperm motility, normal sperm form, total sperm count, semen volume, age, and some sperm kinematics collectively improved the area under the receiver operating characteristic curve (AUROC) to 0.861, surpassing the predictive value of a single predictor of pathologically damaged sperm DNA. Our study suggests that samples with abnormal sperm parameters may have a higher likelihood of high DNA fragmentation. Furthermore, certain semen parameters could be potential indicators of sperm DNA fragmentation, aiding sperm selection in assisted reproductive procedures.

Metabolites assay offers potential solution to improve the rooster semen cryopreservation

Semen cryopreservation represents a promising technology utilized for preserving high-quality chicken varieties in husbandry practices. However, the efficacy of this methodology is significantly impeded by the diminished quality of sperm. Metabolites, as the end products of metabolic reactions, serve as indicators of biological processes and offer insights into physiological conditions. In this study, we investigaged the sperm quality and alteration in metabolic profiles during the cryopreservation of Longyou Partridge Chicken semen. Following artificial semen collection, four groups of semen samples were established based on four points of the cryopreservation process (Ⅰ, fresh semen; Ⅱ, semen added extender and chilled at 4 °C for 30 min; Ⅲ, semen added cryoprotectants; Ⅳ, semen gradient freezed and stored in liquid nitrogen). Semen cryopreservation has a negative effect on the percentage of sperm in a straight-line trajectory (LIN), has no significant effect on total motile sperms (TM) or the proportion of sperm with typical morphology (NM). Metabolites were identified using LC-MS technique and analyses including Principal Component Analysis (PCA), Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), Univariate statistical analysis, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database were employed to identify metabolites. A total of 2471 metabolites had been identified, with the majority of the list being made up of amino acids and their metabolites as well as benzene and substituted derivatives. Group II exhibits 882 metabolites with significantly elevated abundance relative to Group I, alongside 37 metabolites displaying decreased abundance. In Group III, 836 metabolites demonstrate notably augmented abundance compared to Group II, while 87 metabolites exhibit reduced abundance. Furthermore, Group IV showcases 513 metabolites with markedly heightened abundance in comparison to Group III, and 396 metabolites with decreased abundance. Specific metabolites such as 5-Hydroxylysine, Phosphocholine, and alpha-d-glucose-6-phosphate exhibited a progressive decline during the cryopreservation process, correlating with either dilution and chilling, cryoprotectant addition, or freezing. In conclusion, our investigation systematically examined the changes of seminal metabolome and sperm quality throughout the cryopreservation process of rooster semen.

Genome-wide 5'-C-phosphate-G-3' methylation patterns reveal the effect of heat stress on the altered semen quality in Bubalus bubalis

Semen production and quality are closely correlated with different environmental factors in bovines, particularly for the buffalo (Bubalus bubalis) bulls reared under tropical and sub-tropical conditions. Factors including DNA methylation patterns, an intricate process in sperm cells, have an impact on the production of quality semen in buffalo bulls under abiotic stress conditions. The present study was conducted to identify DNA methylome signatures for semen quality in Murrah buffalo bulls, acclaimed as a major dairy breed globally, under summer heat stress. Based on semen quality parameters that significantly varied between the two groups over the seasons, the breeding bulls were classified into seasonally affected (SA = 6) and seasonally non-affected (SNA = 6) categories. DNA was isolated from purified sperm cells and sequenced using the RRBS (Reduced Representation Bisulfite Sequencing) technique for genome-wide methylome data generation. During the hot summer months, the physiological parameters such as scrotal surface temperature, rectal temperature, and respiration rate for both the SA and SNA bulls were significantly higher in the afternoon than in the morning. Whereas, the global CpG% of SA bulls was positively correlated with the afternoon's scrotal surface and rectal temperature. The RRBS results conveyed differentially methylated cytosines in the promoter region of the genes encoding the channels responsible for Ca2+ exchange, NPTN, Ca2+ activated chloride channels, ANO1, and a few structure-related units such as septins (SEPT4 and SEPT6), SPATA, etc. Additionally, the hypermethylated set of genes in SA was significantly enriched for pathways such as the FOXO signaling pathway and oocyte meiosis. The methylation patterns suggest promoter methylation in the genes regulating the sperm structure as well as surface transporters, which could contribute to the reduced semen quality in the Murrah buffalo bulls during the season-related heat stress.

Correlation of Dietary Macro- and Micro-Mineral Intake with Seminal Plasma Quality/Quantity and Oxidant/Antioxidant Status in Infertile Compared to the Normal Men: a Case-Control Study

Male infertility is a global public health issue, but studies on the correlation between the dietary components and sperm quality showed inconclusive results due to the heterogeneous population with different dietary habits and environmental stimuli. Herein, the correlation of dietary macro- and micro-mineral intake was evaluated with quality/quantity and oxidant/antioxidant status of seminal fluid in infertile compared to the healthy men. One hundred twenty men attending to the infertility clinic of Ayatollah Mousavi Hospital in Zanjan City were enrolled. Seminal fluid was extracted, and groups were categorized into the infertile (non-standard) and normal (standard) groups based on the WHO, 2020 criteria. Food frequency questionnaire was completed. Seminal malondialdehyde (MDA) and total antioxidant capacity (TAC) were measured by ELISA kit based on the manufacture's instruction. An independent sample t-test was used to determine differences between the two groups, and linear regression model was used to determine the effect of each dietary macro/micro mineral intake on these parameters. Adjusting for all parameters, dietary selenium increased 3.7-folds the seminal TAC level (p=0.04) and decreased sperm with non-progressive motility by 2.4-folds (p=0.04). Higher manganese intake increased the sperm count by 7.8-folds (p=0.005). Dietary copper decreased sperm vitality and increased sperm with slow motility (OR= -1.7, 95% CI= -59.8, -9.9; p=0.007). Dietary zinc (OR=1.24, p=0.01) and iron (OR=1.5, p=0.02) showed a positive effect on sperm vitality. None of macro and micro minerals showed a significant effect on the seminal MDA level. Daily intake of adequate amounts of micro and macro minerals improves sperm quality and increases the antioxidant capacity of the seminal fluid; however, copper showed a negative correlation that must be evaluated in future studies.

Tip-microVapour Fast Freezing: A novel easy method for cryopreserving severe oligozoospermic samples

BACKGROUND

Sperm cryopreservation is an important procedure for oligozoospermic subjects at risk of azoospermia and after surgical recovery of spermatozoa in non-obstructive azoospermic men. Conventional procedures for sperm cryopreservation might be, however, not suitable for samples with a very low sperm number.

OBJECTIVES

In this pilot study, we investigated the recoveries of sperm motility and viability in severe oligozoospermic subjects (n = 39) after cryopreservation with a tip-microVapour Fast Freezing, a procedure previously developed by our group for men with good semen quality. Sperm DNA fragmentation was also evaluated in a second group of oligozoospermic samples (n = 16).

MATERIALS AND METHODS

We used a Vapour Fast Freezing procedure using 10 μL tips as carrier, and Test Yolk Buffer as freezing medium (tip-microVapour Fast Freezing). In a subset of samples (n = 22), we compared recovery of motility and viability as obtained with tip-microVapour Fast Freezing and with a Vapour Fast Freezing procedure using 500 μL straws. Sperm DNA fragmentation was evaluated by the sperm chromatin dispersion test.

RESULTS

We found a recovery rate (median [interquartile range]) of 0.29 (0.13-0.41) for progressive motility, 0.30 (0.21-0.52) for total motility and 0.48 (0.29-0.60) for viability. Interestingly, we observed that samples with the poorest motility were apparently less damaged by freezing/thawing. In a subset of samples (n = 22), we directly compared values of viability, progressive motility and total motility by freezing/thawing with tip-microVapour Fast Freezing and Vapour Fast Freezing conducted with 500 μL straws. We found much better values of all sperm parameters in samples after freezing/thawing with tip-microVapour Fast Freezing than with Vapour Fast Freezing in 500 μL straws: that is, progressive motility: 7.00 (3.00-8.50)% versus 2.00 (0.00-4.25)%, p < 0.001; total motility: 12.00 (8.00-16.25)% versus 6.50 (1.00-9.25)%, p < 0.001; viability: 29.75 (23.75-45.25) versus 22.50 (13.75-28.13), p < 0.001, respectively. In the second group of oligozoospermic samples, we found that tip-microVapour Fast Freezing produced lower levels of sperm DNA fragmentation than straws (33.00 [19.75-36.00]% vs. 36.00 [22.75-41.87]%, p < 0.001).

DISCUSSION AND CONCLUSION

Tip-microVapour Fast Freezing appears to be a very promising method to cryopreserve semen samples from severe oligozoospermic patients.

Cryopreservation of equine spermatozoa reduces plasma membrane integrity and phospholipase C zeta 1 content as associated with oocyte activation

BACKGROUND

Phospholipase C zeta (PLCZ1) is considered the major sperm-borne oocyte activation factor. Cryopreserved stallion spermatozoa are commonly used for intracytoplasmic sperm injection (ICSI). However, plasma membrane damage and protein modifications caused by cryopreservation could impair sperm structure and function, leading to a reduction of PLCZ1 and oocyte activation after ICSI.

OBJECTIVES

We compared membrane integrity and PLCZ1 abundance in populations for fresh, frozen, and refrozen stallion spermatozoa, either thawed and refrozen at room or low temperature; and examined the effect of relative PLCZ1 content on cleavage after ICSI.

MATERIALS AND METHODS

Western blotting, ELISA, and immunofluorescence were conducted in stallion spermatozoa, freezing extenders, and detergent-extracted sperm fractions to detect and quantify PLCZ1. Retrospectively, PLCZ1 content and cleavage rate were analyzed. Fresh, frozen, and refrozen at room and low temperatures spermatozoa were evaluated for acrosomal and plasma membrane integrity and PLCZ1 content using flow cytometry.

RESULTS

Western blotting, ELISA, and immunofluorescence revealed significant reduction of PLCZ1 in spermatozoa after cryopreservation and confirmed PLCZ1 detection in extenders. After detergent extraction, a PLCZ1-nonextractable fraction remained in the postacrosomal region of spermatozoa. Plasma membrane integrity was significantly reduced after freezing. Acrosomal and plasma membrane integrity were similar between frozen and refrozen samples at low temperature, but both were significantly higher than samples refrozen at room temperature. Acrosomal and plasma membrane integrity significantly correlated to PLCZ1 content. Percentages of PLCZ1-labeled spermatozoa and PLCZ1 content were reduced after freezing but not after refreezing. Relative content and localization of PLCZ1 were associated with cleavage rates after ICSI.

DISCUSSION AND CONCLUSION

Sperm PLCZ1 content associates with cleavage rates after ICSI. Cryopreservation is detrimental to sperm plasma membrane integrity and PLCZ1 retention. However, refreezing did not result in additional PLCZ1 loss. Refreezing stallion spermatozoa at a low temperature resulted in better survival but did not improve PLCZ1 retention.

Ameliorative Effects of Zinc Oxide, in Either Conventional or Nanoformulation, Against Bisphenol A Toxicity on Reproductive Performance, Oxidative Status, Gene Expression and Histopathology in Adult Male Rats

Bisphenol A (BPA) is a widely used endocrine disruptor that represents a significant risk to male reproductive function. Zinc (Zn) is vital for appropriate development of testes and to guarantee optimal testicular function and spermatogenesis. Our goal was to investigate if zinc oxide (ZnO), either in conventional or nanoformulation, could safeguard adult male rats' reproductive performance against the damaging effects of BPA. Signaling expression of CYP11A1 and Nrf-2 in the testis, testicular oxidant-antioxidant status, Bax/Bcl-2 apoptotic ratio, and histological examination of various reproductive organs were all evaluated. Twenty-eight adult male albino rats were divided randomly into 4 groups (7 animals each) including the control, BPA, conventional zinc oxide (cZnO) + BPA, and zinc oxide nanoparticles (ZnO-NPs) + BPA groups. The study was extended for 2 successive months. Our findings revealed strong negative effects of BPA on sperm cell characteristics such as sperm motility, viability, concentration and abnormalities. Additionally, BPA reduced serum levels of testosterone, triiodothyronine (T3), and thyroxine (T4). Also, it evoked marked oxidative stress in the testes; elevating malondialdehyde (MDA) and reducing total antioxidant capacity (TAC). BPA significantly downregulated testicular mRNA relative expression levels of CYP11A1 and Nrf-2, compared to control. Testicular apoptosis was also prompted by increasing Bax/ Bcl-2 ratio in testicular tissue. Histopathological findings in the testes, epididymis, prostate gland, and seminal vesicle confirmed the detrimental effects of BPA. Interestingly, cZnO and ZnO-NPs significantly alleviated all negative effects of BPA, but ZnO-NPs performed better. In conclusion, our findings point to ZnO, specifically ZnO-NPs, as a viable treatment for BPA-induced testicular dysfunction.

Quantitative phosphoproteomics explain cryopreservation-induced reductions in ram sperm motility

Sperm cryopreservation decreases motility, probably due to changes in protein phosphorylation. Our objective was to use quantitative phosphoproteomics for systematic comparative analyses of fresh versus frozen-thawed sperm to identify factors causing cryo-injury. Ejaculates were collected (artificial vagina) from six Dorper rams, pooled, extended, and frozen over liquid nitrogen. Overall, 915, 3382, and 6875 phosphorylated proteins, phosphorylated peptides, and phosphorylation sites, respectively, were identified. At least two modified sites were present in 57.94% of the 6875 phosphosites identified, of which AKAP4 protein contained up to 331 modified sites. There were 732 phosphorylated peptides significantly up-regulated and 909 significantly down-regulated in frozen-thawed versus fresh sperm. Moreover, the conserved motif [RxxS] was significantly down-regulated in frozen-thawed sperm. Phosphorylation of sperm-specific proteins, e.g., AKAP3/4, CABYR, FSIP2, GSK3A/B, GPI, and ODF1/2 make them potential biomarkers to assess the quality of frozen-thawed ram sperm. Furthermore, these differentially phosphorylated proteins and modification sites were implicated in cryopreservation-induced changes in sperm energy production, fiber sheath composition, and various biological processes. We concluded that abnormal protein phosphorylation modifications are key regulators of reduced sperm motility. These novel findings implicated specific protein phosphorylation modifications in sperm cryo-injury. SIGNIFICANCE: This study used phosphorylated TMT quantitative proteomics to explore regulation of epigenetic modifications in frozen-thawed ram sperm. This experiment demonstrated that ram sperm freezing affects phosphorylation site modifications of proteins, especially those related to functions such as sperm motility and energy production. Furthermore, it is important to link functions of phosphorylated proteins with changes in sperm quality after freezing and thawing, and to clarify intrinsic reasons for sperm quality changes, which is of great importance for elucidating mechanisms of sperm freezing damage. Based on these protein markers and combined with cryoprotectant design theory, it provides a theoretical basis and data reference to study sperm cryoprotectants.

Sperm quality variables of sex-sorted bull semen produced by magnetic-activated cell sorting coupled with recombinant antibodies targeting Y-chromosome-bearing sperm

The immunological sexing method using antibodies offers cost-effective, high-volume production but faces challenges in terms of X-sperm purity in sexed semen. This research aimed to produce sexed bull semen using highly specific recombinant antibodies in magnetic-activated cell sorting (MACS), evaluate sperm quality and kinematic parameters, and verify the sex ratio of sperm, embryos, and live calves. Fresh semen from two Angus bulls was separated into two equal groups: conventional (CONV) semen and semen sexed using MACS with Y-scFv antibody conjugation to separate two fractions, i.e., the X-enriched and Y-enriched fractions. Then, computer assisted semen analysis and imaging flow cytometry were used to evaluate sperm motility and kinematic variables, acrosomal integrity, sperm viability, and sperm sex ratios. The results showed that sperm motility and quality did not differ between X-enriched and CONV semen. However, the Y-enriched fraction showed significantly lower sperm quality than the X-enriched fraction and CONV semen. The sperm ratio revealed that X-sperm accounted for up to 79.50% of the X-enriched fraction, while Y-sperm accounted for up to 78.56% of the Y-enriched fraction. The sex ratio of embryos was examined using in vitro fertilization. The cleavage rates using CONV and X-enriched semen were significantly higher than that using Y-enriched semen. Accordingly, 88.26% female blastocysts were obtained by using X-enriched semen, and 83.58% male blastocysts were obtained by using Y-enriched semen. In farm trials, 304 cows were subjected to AI using X-enriched and CONV semen. The pregnancy rate did not differ between the X-enriched and CONV semen groups. On the other hand, X-enriched semen generated significantly more live female calves (83.64%) than CONV semen (47.00%). The MACS sexing method significantly enhanced the X-sperm purity in sexed semen, producing high-quality sperm, a high percentage of female blastocytes, and a high percentage of live female calves.

Exosomes from porcine serum as endogenous additive maintain function of boar sperm during liquid preservation at 17 °C in vitro

The supplementation of sperm culture media with serum is quite common, and improves both sperm survival and motility. However, the link between serum and sperm remains poorly understood. The present study is the first investigation of the effects on sperm quality and function of endogenous porcine serum exosomes in medium used for culturing boar sperm. Scanning electron microscopy (SEM) confirmed that serum-derived exosomes from both castrated boars (cbsExos) and sows (ssExos) exhibited typical nanostructural morphology and expressed CD63, CD9, and Alix, as shown by Western blotting. At 17 °C, the progressive motility and membrane integrity of sperm were significantly increased after incubation of fresh boar semen for 7 days with cbsExos-4 (8 × 1010 particles/mL) or ssExos-16 (32 × 1010 particles/mL). Moreover, cbsExos-4 and ssExos-16 were found to be effective sperm additives, improving mitochondrial transmembrane potential (ΔΨm) and adenosine triphosphate (ATP) content, total antioxidant activity (T-AOC), superoxide dismutase (SOD) activity, and glutathione peroxidase (GPx) activity while reducing reactive oxygen species (ROS) levels, and malondialdehyde (MDA) content following preservation at 17 °C after a 5-day incubation. Both fluorescence and SEM showed that the serum exosomes bound directly to the sperm membrane, suggesting an interaction that could influence sperm-zona pellucida binding. Overall, this study provides new insights into the potential benefits of adding cbsExos and ssExos to enhance the quality of boar sperm during ambient temperature preservation, which may lead to advancements in sperm preservation strategies.

LRRC52 is likely a functional component of human KSper†

Completion of fertilization is orchestrated by various ion channels in sperm membrane. Hyperpolarization of membrane potential, an indispensable event during the capacitation process, is dominated by sperm potassium channel (KSper). In addition to sperm-specific SLO3, which forms the channel pore, the auxiliary subunit leucine-rich-repeat-containing protein 52 (LRRC52) is required to form mKSper to function under physiological conditions. However, in human sperm, although most evidence supports that hSLO3 is the pore-forming subunit, whether hLRRC52 contributes to hKSper conductance and modulates sperm function remains to be understood. Here, using an extracellular segment that is homologous between mice and humans as an antigen, we developed a polyclonal antibody designed as LID1 that specifically detected mLRRC52 and performed co-immunoprecipitation with mSLO3. Additionally, patch-clamp recordings of mouse sperm showed that, physiological activation of mKSper and sperm functions were dramatically attenuated after treatment with LID1, indicating that LID1 functionally disrupted the regulation of mLRRC52 on mKSper. Next, LID1 was used to investigate the significance of hLRRC52 for hKSper activation. As a result, hLRRC52 was expressed in human sperm and might be assembled with hSLO3. More importantly, LID1 inhibited hKSper currents and depolarized sperm membrane potential, supporting essential modulation of hLRRC52 in hKSper. Ca2+ signaling of human sperm was also compromised in the presence of LID1, which impaired sperm motility and acrosome reaction. Because LID1 specifically inhibited both mKSper and hKSper but not mCatSper or hCatSper, our results suggest that hLRRC52 functions as an important component of hKSper and regulates sperm physiological functions.

Metabolic profiling identifies Qrich2 as a novel glutamine sensor that regulates microtubule glutamylation and mitochondrial function in mouse sperm

In our prior investigation, we discerned loss-of-function variants within the gene encoding glutamine-rich protein 2 (QRICH2) in two consanguineous families, leading to various morphological abnormalities in sperm flagella and male infertility. The Qrich2 knockout (KO) in mice also exhibits multiple morphological abnormalities of the flagella (MMAF) phenotype with a significantly decreased sperm motility. However, how ORICH2 regulates the formation of sperm flagella remains unclear. Abnormal glutamylation levels of tubulin cause dysplastic microtubules and flagella, eventually resulting in the decline of sperm motility and male infertility. In the current study, by further analyzing the Qrich2 KO mouse sperm, we found a reduced glutamylation level and instability of tubulin in Qrich2 KO mouse sperm flagella. In addition, we found that the amino acid metabolism was dysregulated in both testes and sperm, leading to the accumulated glutamine (Gln) and reduced glutamate (Glu) concentrations, and disorderly expressed genes responsible for Gln/Glu metabolism. Interestingly, mice fed with diets devoid of Gln/Glu phenocopied the Qrich2 KO mice. Furthermore, we identified several mitochondrial marker proteins that could not be correctly localized in sperm flagella, which might be responsible for the reduced mitochondrial function contributing to the reduced sperm motility in Qrich2 KO mice. Our study reveals a crucial role of a normal Gln/Glu metabolism in maintaining the structural stability of the microtubules in sperm flagella by regulating the glutamylation levels of the tubulin and identifies Qrich2 as a possible novel Gln sensor that regulates microtubule glutamylation and mitochondrial function in mouse sperm.

Kaempferol as an Alternative Cryosupplement for Bovine Spermatozoa: Cytoprotective and Membrane-Stabilizing Effects

Kaempferol (KAE) is a natural flavonoid with powerful reactive oxygen species (ROS) scavenging properties and beneficial effects on ex vivo sperm functionality. In this paper, we studied the ability of KAE to prevent or ameliorate structural, functional or oxidative damage to frozen-thawed bovine spermatozoa. The analysis focused on conventional sperm quality characteristics prior to or following thermoresistance tests, namely the oxidative profile of semen alongside sperm capacitation patterns, and the levels of key proteins involved in capacitation signaling. Semen samples obtained from 30 stud bulls were frozen in the presence of 12.5, 25 or 50 μM KAE and compared to native ejaculates (negative control-CtrlN) as well as semen samples cryopreserved in the absence of KAE (positive control-CtrlC). A significant post-thermoresistance test maintenance of the sperm motility (p < 0.001), membrane (p < 0.001) and acrosome integrity (p < 0.001), mitochondrial activity (p < 0.001) and DNA integrity (p < 0.001) was observed following supplementation with all KAE doses in comparison to CtrlC. Experimental groups supplemented with all KAE doses presented a significantly lower proportion of prematurely capacitated spermatozoa (p < 0.001) when compared with CtrlC. A significant decrease in the levels of the superoxide radical was recorded following administration of 12.5 (p < 0.05) and 25 μM KAE (p < 0.01). At the same time, supplementation with 25 μM KAE in the cryopreservation medium led to a significant stabilization of the activity of Mg2+-ATPase (p < 0.05) and Na+/K+-ATPase (p < 0.0001) in comparison to CtrlC. Western blot analysis revealed that supplementation with 25 μM KAE in the cryopreservation medium prevented the loss of the protein kinase A (PKA) and protein kinase C (PKC), which are intricately involved in the process of sperm activation. In conclusion, we may speculate that KAE is particularly efficient in the protection of sperm metabolism during the cryopreservation process through its ability to promote energy synthesis while quenching excessive ROS and to protect enzymes involved in the process of sperm capacitation and hyperactivation. These properties may provide supplementary protection to spermatozoa undergoing the freeze-thaw process.

Systematic analyses of the factors influencing sperm quality in patients with SARS-CoV-2 infection

To figure out how does SARS-CoV-2 affect sperm parameters and what influencing factors affect the recovery of sperm quality after infection? We conducted a prospective cohort study and initially included 122 men with SARS-CoV-2 infection. The longest time to track semen quality after infection is 112 days and 58 eligible patients were included in our study eventually. We subsequently exploited a linear mixed-effects model to statistically analyze their semen parameters at different time points before and after SARS-CoV-2 infection. Semen parameters were significantly reduced after SARS-CoV-2 infection, including total sperm count (211 [147; 347] to 167 [65.0; 258], P < 0.001), sperm concentration (69.0 [38.8; 97.0] to 51.0 [25.5; 71.5], P < 0.001), total sperm motility (57.5 [52.3; 65.0] to 51.0 [38.5; 56.8], P < 0.001), progressive motility (50.0 [46.2; 58.0] to 45.0 [31.5; 52.8], P < 0.001). The parameters displayed the greatest diminution within 30 days after SARS-CoV-2 infection, gradually recovered thereafter, and exhibited no significant difference after 90 days compared with prior to COVID-19 infection. In addition, the patients in the group with a low-grade fever showed a declining tendency in semen parameters, but not to a significant degree, whereas those men with a moderate or high fever produced a significant drop in the same parameters. Semen parameters were significantly reduced after SARS-CoV-2 infection, and fever severity during SARS-CoV-2 infection may constitute the main influencing factor in reducing semen parameters in patients after recovery, but the effect is reversible and the semen parameters gradually return to normal with the realization of a new spermatogenic cycle.

Progesterone and estradiol regulate sperm hyperactivation and in vitro fertilization success in mice

Progesterone (P) and 17β-estradiol (Eβ) form the well-known hormone pair that regulates sperm capacitation. Here, we examined the regulatory effects of P and Eβ on sperm hyperactivation in mice and evaluated the in vitro fertilization (IVF) success. Although P enhanced hyperactivation, Eβ dose-dependently suppressed the P-enhanced hyperactivation. Moreover, P increased IVF success, whereas Eβ suppressed the P-induced increase in IVF success in a dose-dependent manner. Thus, P and Eβ competitively regulate hyperactivation and IVF success in mice. Since P and Eβ concentrations generally change during the estrous cycle, sperm are speculated to capacitate in response to the oviductal environment and fertilize the oocyte.

Flagellar pH homeostasis mediated by Na+/H+ exchangers regulates human sperm functions through coupling with CatSper and KSper activation

STUDY QUESTION

Whether and how do Na+/H+ exchangers (NHEs) regulate the physiological functions of human sperm?

SUMMARY ANSWER

NHE-mediated flagellar intracellular pH (pHi) homeostasis facilitates the activation of the pH-sensitive, sperm-specific Ca2+ channel (CatSper) and the sperm-specific K+ channel (KSper), which subsequently modulate sperm motility, hyperactivation, flagellar tyrosine phosphorylation, and the progesterone (P4)-induced acrosome reaction.

WHAT IS KNOWN ALREADY

Sperm pHi alkalization is an essential prerequisite for the acquisition of sperm-fertilizing capacity. Different sperm functions are strictly controlled by particular pHi regulatory mechanisms. NHEs are suggested to modulate sperm H+ efflux.

STUDY DESIGN, SIZE, DURATION

This was a laboratory study that used samples from >50 sperm donors over a period of 1 year. To evaluate NHE action on human sperm function, 5-(N,N-dimethyl)-amiloride (DMA), a highly selective inhibitor of NHEs, was utilized. All experiments were repeated at least five times using different individual sperm samples or cells.

PARTICIPANTS/MATERIALS, SETTING, METHODS

By utilizing the pH fluorescent indicator pHrodo Red-AM, we detected alterations in single-cell pHi value in human sperm. The currents of CatSper and KSper in human sperm were recorded by the whole-cell patch-clamp technique. Changes in population and single-cell Ca2+ concentrations ([Ca2+]i) of human sperm loaded with Fluo 4-AM were measured. Membrane potential (Vm) and population pHi were quantitatively examined by a multimode plate reader after sperm were loaded with 3,3'-dipropylthiadicarbocyanine iodide and 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester, respectively. Sperm motility parameters were assessed by a computer-assisted semen analysis system. Tyrosine phosphorylation was determined by immunofluorescence, and sperm acrosome reaction was evaluated by Pisum sativum agglutinin-FITC staining.

MAIN RESULTS AND THE ROLE OF CHANCE

DMA-induced NHEs inhibition severely acidified the human sperm flagellar pHi from 7.20 ± 0.04 to 6.38 ± 0.12 (mean ± SEM), while the effect of DMA on acrosomal pHi was less obvious (from 5.90 ± 0.13 to 5.57 ± 0.12, mean ± SEM). The whole-cell patch-clamp recordings revealed that NHE inhibition remarkably suppressed alkalization-induced activation of CatSper and KSper. As a consequence, impairment of [Ca2+]i homeostasis and Vm maintenance were detected in the presence of DMA. During the capacitation process, pre-treatment with DMA for 2 h potently decreased sperm pHi, which in turn decreased sperm motility and kinetic parameters. Sperm capacitation-associated functions, including hyperactivation, tyrosine phosphorylation, and P4-induced acrosome reaction, were also compromised by NHE inhibition.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This was an in vitro study. Caution should be taken when extrapolating these results to in vivo applications.

WIDER IMPLICATIONS OF THE FINDINGS

This study revealed that NHEs are important physiological regulators for human CatSper and KSper, which are indispensable for human sperm fertility, suggesting that malfunction of NHEs could be an underlying mechanism for the pathogenesis of male infertility.

FUNDING/COMPETING INTEREST(S)

This work was supported by the National Natural Science Foundation of China (32271167 and 81871202 to X.Z.), Jiangsu Innovation and Entrepreneurship Talent Plan (JSSCRC20211543 to X.Z.), the Social Development Project of Jiangsu Province (No. BE2022765 to X.Z.), the Society and livelihood Project of Nantong City (No. MS22022087 to X.Z.), and the Natural Science Foundation of Jiangsu Province (BK20220608 to H.K.). The authors have no competing interests to declare.

Transferrin maintains the motility rate, ATP content, and DNA integrity of common carp spermatozoa during short-term storage

Short-term sperm storage is a straightforward and cost-effective method of managing logistics in large scale fish hatchery operations but may result in decline in sperm quality. For effective artificial reproduction of fish, use of an appropriate additive to optimize sperm storage conditions is essential. In this study, it was investigated the effect of purified seminal plasma transferrin (Tf) at 10 μg/ml on relevant parameters in common carp Cyprinus carpio sperm during short-term storage. We compared sperm motility and curvilinear velocity, adenosine triphosphate (ATP) content and DNA fragmentation of fresh spermatozoa to that stored for 24, 48, 72, and 144 h with or without Tf. The percentage of motile cells and the curvilinear velocity of spermatozoa in stored samples for 72 h with transferrin supplementation were greater compared to samples with no added protein. The ATP content in samples without added transferrin was reduced (P < 0.05) after 72 h of storage, in contrast to the levels observed in transferrin-supplemented sperm. A time-dependent increase in DNA fragmentation was observed. Significantly lower DNA damage, expressed as percent tail DNA (10.99 ± 1.28) and olive tail moment (0.54 ± 0.12), was recorded in Tf-supplemented samples stored for 48 h compared to that with no Tf. Hence, it is concluded that the beneficial effects of transferrin on common carp sperm could serve as an additional tool for developing and enhancing short-term sperm preservation procedures commonly used in aquaculture.

Proteomic analysis of fipronil-induced molecular defects in spermatozoa

The phenylpyrazole insecticide fipronil has wide-ranging applications from agriculture to public health to control undesirable organisms. However, several studies have reported the residual environmental hazards of fipronil and demonstrated its harmful effects even in mammalian reproduction. Therefore, this study was conducted to demonstrate the mode of action of fipronil on mouse spermatozoa. We treated fipronil to spermatozoa and performed comprehensive function evaluations. Moreover, proteomic analyses were conducted to identify the alteration of protein expression levels in spermatozoa. Most of sperm motility and kinematic parameters and intracellular ATP levels were diminished, and the spontaneous acrosome reaction was promoted after treatment with fipronil. Proteomic analyses revealed altered expression levels of 14 proteins after treatment. These proteins have been reported to be associated with sperm-specific pathways, prominently the cytoskeleton of the sperm, "9 + 2" axoneme composition, metabolism, and fertility. Collectively, our results showed that fipronil alters sperm functional-related proteins and therefore influences male fertility. This study elucidates the possible reproductive toxic hazards associated with male infertility through aberrant suppression of sperm proteins.

Predicting the cryotolerance of boar sperm through antioxidant stress

High sperm cryotolerance is crucial to the successful cryopreservation of boar sperm. Evaluating the cryotolerance of boar sperm by using a rapid and convenient technique can enhance the commercial viability of these sperm. This study investigated the correlation between sperm parameters for three sample subsets-fresh sperm, sperm with H2O2-induced oxidative damage (hereinafter referred to as H2O2-induced sperm), and frozen-thawed sperm-to identify the potential of these correlations to predict cryotolerance. A total of 64 sperm samples were obtained from 64 Duroc boars. The sperm parameters of the three subsets, where the frozen-thawed sperm were analysed at 30 or 180 min after thawing, were determined, and the coefficients of correlation between these parameters were calculated. The results indicated that H2O2-induced oxidative stress resulted in decreases in various sperm parameters-including total motility (TM), viability (VIA), mitochondrial membrane potential (MMP), and live sperm with MMP (LMP)-but increased their coefficients of variation. Receiver operating characteristic (ROC) curve analysis revealed that the kinematic parameters of the H2O2-induced sperm effectively predicted those of the frozen-thawed boar sperm at 30 min after thawing; the corresponding area under the ROC curve (AUC) was 0.8667 for TM and 0.8733 for progressive motility in the H2O2-induced sperm. For measurement at 180 min after thawing, the sperm membrane and mitochondrial parameters of the H2O2-induced sperm effectively predicted the LMP of the frozen-thawed boar sperm; the corresponding AUC was 0.8489 for VIA, 0.8289 for MMP, and 0.8444 for LMP. To our knowledge, this is the first study to directly establish a strong correlation between post-thaw boar sperm quality and H2O2-induced oxidative stress before freezing. Our proposed technique can serve as a valuable reference for the development of practical applications aimed at enhancing techniques for cryopreserving boar sperm.

Vibration emissions affect the quality of liquid-preserved AI doses in stallions

Artificial insemination (AI) with liquid-preserved stallion semen is a widely used reproductive technology. As the demand for AI doses of high-class stallions is transnational, they are frequently exposed to long-distance transport. Since recent studies in boars indicated that vibration emissions caused by transport negatively affected sperm quality in vitro, this study questioned whether sperm quality in stallions is similarly impaired. Furthermore, we investigated stallion and extender-related differences in the spermatozoa's resistance to transport-related quality loss. Stallion ejaculates (n = 30) were collected at a German AI center, split in half, and subsequently diluted to a final sperm concentration of 50 × 106 sperm/mL using the semen extenders EquiPlus or Gent (both Minitüb GmbH, Germany). Four 12 mL aliquots of each sample were filled in plastic syringes according to a split-sample design and exposed to vibration (Displacement index Di = 3.0 ± 0.1) at 5 °C for 0 h (control), 3 h, 6 h or 9 h. All samples were stored for four days at 5 °C after transport simulation and analyzed for total sperm motility, thermo-resistance, membrane integrity, and mitochondrial activity determined by flow cytometry as well as the pH. After calculating generalized linear mixed models for each sperm quality trait, a negative impact of the duration of transport simulation could be shown on total sperm motility (P = 0.001), thermo-resistance (P = 0.030), and the pH (P = 0.001). Simulated transport for 6 h and 9 h diminished sperm quality (P ≤ 0.01), with 9 h reducing thermo-resistance by 5 ± 2.2% points (PP) for EquiPlus and sperm motility by 2.2 ± 1.7 PP for Gent compared to the control group. In contrast, samples exposed to vibration for 3 h showed no decline in sperm quality (P > 0.05). The individual stallion influenced every semen trait (P < 0.05) and transport-related losses in sperm thermo-resistance of up to 15.9 PP were demonstrated. Furthermore, EquiPlus was superior to Gent in all semen assessments (P < 0.001). We conclude that in vitro sperm quality is impaired by vibration. As the quality loss depends on the transport time, we recommend keeping shipping time as short as possible especially for spermatozoa of stallions that are susceptible to vibration-induced sperm quality loss.

An updated review on the application of proteomics to explore sperm cryoinjury mechanisms in livestock animals

This comprehensive review critically examines the application of proteomics in understanding sperm cryoinjury mechanisms in livestock animals, in the context of the widespread use of semen cryopreservation for genetic conservation. Despite its global adoption, cryopreservation often detrimentally affects sperm quality and fertility due to cryoinjuries. These injuries primarily arise from ice crystal formation, osmotic shifts, oxidative stress, and the reorganization of membrane proteins and lipids during freezing and thawing, leading to premature capacitation-like changes. Moreover, the cryopreservation process induces proteome remodeling in mammalian sperm. Although there have been technological advances in semen cryopreservation, the precise mechanisms of mammalian sperm cryoinjury remain elusive. This review offers an in-depth exploration of how recent advancements in proteomic technologies have enabled a detailed investigation into these molecular disruptions. It presents an analysis of protein-level alterations post-thaw and their impact on sperm viability and functionality. Additionally, it discusses the role of proteomics in refining cryopreservation techniques to mitigate cryoinjury and enhance reproductive outcomes in livestock. This work synthesizes current knowledge, highlights gaps, and suggests directions for future research in animal reproductive science and biotechnology.

Clinical Utility of Sperm Function Tests in Predicting Male Fertility: A Systematic Review

Routine semen analysis provides considerable information regarding sperm parameters; however, it is not solely adequate to predict male fertility potential. In the past two decades, several advance sperm function tests have been developed. The present systematic review intends to assess the clinical utility of available advance sperm function tests in predicting the male fertility potential. A systematic literature search was conducted as per PRISMA guidelines using PubMed, MEDLINE, Google Scholar, and Cochrane Library. Different keywords either singly or in combination were used to retrieve the relevant articles related to sperm function tests, male fertility, and pregnancy outcomes. A total of 5169 articles were obtained, out of which 110 meeting the selection criteria were included in this review. The majorly investigated sperm function tests are hypo-osmotic swelling test, acrosome reaction test, sperm capacitation test, hemizona binding assay, sperm DNA fragmentation test, seminal reactive oxygen species test, mitochondrial dysfunction tests, antisperm antibody test, nuclear chromatin de-condensation (NCD) test, etc. The different advance sperm function tests analyse different aspects of sperm function. Hence, any one test may not be helpful to appropriately predict the male fertility potential. Currently, the unavailability of high-quality clinical data, robust thresholds, complex protocols, high cost, etc., are the limiting factors and prohibiting current sperm function tests to reach the clinics. Further multi-centric research efforts are required to fulfil the existing lacunas and pave the way for these tests to be introduced into the clinics.

L-Proline: A Promising Tool for Boosting Cryotolerance and Fertilizing Ability of Cryopreserved Sperm in Animals

Sperm cryopreservation technology significantly contributes to the safeguarding of genetic resources, particularly for endangered species, and supports the use of artificial insemination in domestic animals. Therefore, cryopreservation can negatively affect sperm health and function leading to reduce the freezing ability and fertility potential. Therefore, it is essential to prioritize the improvement of cryotolerance in cryopreserved sperm to enhance reproductive efficiency and ensure sustainability in livestock herds. The main reason for sperm dysfunction after thawing may be related to the excessive amount of oxidative stress (OS) produced during cryopreservation. Scientists have different ways for counteracting this OS including the use of plant extracts, enzymes, minerals, anti-freezing proteins, and amino acids. Recently, one such amino acid is L-proline (LP), which has multiple roles such as osmotic and OS defense, nitrogen, and carbon metabolism, as well as cell survival and signaling. LP has been found in seminal plasma and has recently been added to the freezing extender to improve the various post-thaw parameters of sperm. This improvement is related to the ability of LP to reduce the OS, sustain the plasma membrane and to act as an osmoregulatory agent. Moreover, LP can suppress cell apoptosis by modulating intracellular redox in sperm. This review addresses the ongoing research on the addition of L-proline as an osmoregulatory agent in freezing extenders to increase the cryotolerance of animal spermatozoa to freeze-thaw.

Adverse Effects of Avobenzone on Boar Sperm Function: Disruption of Protein Kinase A Activity and Tyrosine Phosphorylation

Avobenzone (AVO), an ultraviolet (UV) filter, is frequently used as an ingredient in personal cosmetics. This UV filter has been found to be easily exposed in swimming pools and beaches, and it has been detected in human urine and blood. Moreover, numerous studies have demonstrated that AVO exhibits endocrine-disrupting properties. Nevertheless, the effects of AVO on male fertility have not yet fully understood. Therefore, this study aimed to assess the effects of AVO on various sperm functions during capacitation. First, boar spermatozoa were treated with various AVO concentrations. After treatment, sperm motility and kinetic characteristics, capacitation status, intracellular adenosine triphosphate (ATP) levels, and sperm viability were evaluated. Moreover, Western blot analysis w.as conducted to evaluate protein kinase A (PKA) activity and tyrosine phosphorylation. As a result, AVO treatment significantly decreased total motility, progressive motility, and several kinetic characteristics at high concentrations (50 and 100 μM). Furthermore, the capacitation status dose-dependently decreased. Conversely, no significant differences in acrosome reaction, cell viability, and intracellular ATP levels were observed. However, the intracellular ATP level tended to decrease. In addition, AVO dose-dependently induced abnormal changes in PKA activity and tyrosine phosphorylation. Although AVO did not directly exert a toxic effect on cell viability, it ultimately negatively affected sperm functions through abnormal alterations in PKA activity and tyrosine phosphorylation. Thus, the potential implications on male fertility must be considered when contemplating the safe utilization of AVO.

A ripple effect? The impact of obesity on sperm quality and function

Infertility affects approximately 15% of couples trying to conceive. Male-related causes account for roughly 50% of cases, with obesity emerging as a possible significant factor. Obesity, defined as a body mass index of 30.0 or higher, has become a widespread epidemic associated with numerous health issues, including a decrease of fertility. This review discusses the relationship between obesity and male infertility, particularly focusing on sperm quality and function. An overview of the literature suggests that obesity may influence the male reproductive system via disruptions in hormonal profiles, oxidative stress, and inflammation, leading to changes in sperm parameters. Several studies have discussed if obesity causes a decrease in sperm concentration, motility, and normal morphology, so far without a consensus being reached. However, available evidence suggests an impairment of sperm function in obese men, due to an increase in DNA damage and oxidative stress, impaired mitochondrial function and acrosome reaction in response to progesterone. Finally, the relationship between obesity and assisted reproductive technologies outcomes remains debatable, with conflicting evidence regarding the influence on fertilisation, pregnancy, and live birth rates. Therefore, the actual impact of obesity on human spermatozoa still needs to be clarified, due to the multiple factors potentially in play.

The impact of Origanum Vulgare essential oil supplementation on sperm motility and subpopulation alterations in bulls, dogs, and rabbits

Artificial insemination is a widely adopted method in livestock production for various reasons such as health security and genetic improvement. Although sperm motility is of paramount importance in this technique as it directly influences the sperm's ability to fertilize the oocyte. In previous research on human sperm, we observed that in vitro supplementation with Origanum Vulgare essential oil significantly improved sperm motility and antioxidant activities, all without negatively affecting the integrity of their DNA. Based on these promising results, we considered it crucial to explore the potential effects of supplementation with this essential oil on sperm of other species. In this study, we studied the effects of oregano essential oil supplementation on sperm motility of (bulls = 15) (dogs = 15) and (rabbits = 9) and the changes that in vitro incubation with this oil could induce on sub-motile sperm populations of different species. The results of the study showed that in vitro oregano essential oil supplementation had a significant impact on sperm motility in the three species studied. This improvement in sperm motility was accompanied by an increase in the proportion of subpopulations with high velocity and progressivity: an increase of (2.16%, 10% and 4.84%) for subpopulation 1, (6.50%, 5.5% and 3.17%) for subpopulation 4 in bulls, dogs and rabbits respectively. While the subpopulations representing low motile and non-progressive sperm have decreased. These results suggest that the use of oregano essential oil can be a beneficial approach to improve sperm motility in different species, which can have important implications for the success of artificial insemination.

Rats' testicular toxicity induced by bisphenol A is lessened by crocin via an antiapoptotic mechanism and bumped P-glycoprotein expression

Bisphenol A (BPA) engenders testicular toxicity via hydroxyl free radical genesis in rat striatum and depletion of the endogenous antioxidants in the epididymal sperms. The multi-drug resistance efflux carrier; P-glycoprotein (P-gp) expel the BPA from the testis and is responsible for the testicular protection through the deactivation of numerous xenobiotics. In our study, we investigated whether the BPA-induced testicular toxicity could be circumvented through administration of an antioxidant; crocin (Cr). Implication of P-gp expression was also investigated. Rats administered BPA (10 mg/kg b.w. orally for 14 days), dropped the body weight, testes/body weight ratio, total protein content, testosterone, follicle stimulating hormone, luteinizing hormone, and sperm motility & count, total antioxidant status, glutathione content and antioxidant enzymes (superoxide dismutase and catalase), concomitant with the elevation of the percentage abnormal sperm morphology, as well as testicular lipid peroxides and nitrite/nitrate levels. Histopathological examination showed spermatogenesis disorders after the BPA rats exposure. The immunohistochemical study showed up-regulation of the P-gp as evident by increasing immunoreactivity in interstitial cells, with positive localization in some spermatogonia cells. The BPA-treated rats showed positive immunoreactivity against caspase-3. The co-intake of Cr (200 mg/kg b.w./day, i.p. 14 days) along with the BPA, significantly ameliorated all the mentioned parameters, boosted histopathological image, fell the caspase-3 up-regulation, and perched the P-gp expression. We showed that, Cr promotes P-gp as an approach to nurture the testicles against the BPA toxicity. In conclusion; Cr lessens the oxidative stress conditions to safeguard rats from the BPA-induced testicular toxicity and sex hormones abnormalities, reducing apoptosis and up-regulating P-gp.

Association of Serum Vitamin D level with Asthenozoospermic Male

Although vitamin D deficiency is one of the most common health problems throughout the world, conflicting information exists on the potential association between serum vitamin D levels and semen quality. Currently available data identifies that vitamin D has a vital role in reproductive process as it affects sperm motility. This study was done with the rationality to evaluate the association between serum vitamin D levels with asthenozoospermic males. This cross-sectional analytic study was conducted on 314 men who attended the Department of Reproductive Endocrinology and Infertility, Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh July 2018 to June 2019. Considering the inclusion and exclusion criteria all participants were categorized into two groups; Group I included 157 asthenozoospermic male and Group II included 157 normozoospermic male according to World Health Organization 'strict' criteria 2010. Participants completed the questionnaires after they had agreed on a informed consent. Blood and semen samples were obtained for assessment and all data were adjusted for age, body mass index (BMI), total motility and progressive motility. Vitamin D levels were classified according to the Endocrine Society guideline. Statistical analyses were carried out by using the Statistical Package for Social Sciences version 22.0 for Windows (SPSS Inc., Chicago, Illinois, USA). The results showed that the mean vitamin D level was 16.63±5.54ng/ml in asthenozoospermic group and 19.83±5.33ng/ml in normozoospermic group. The mean vitamin D level was significantly (p<0.05) lower in asthenozoospermic group. It was noticed that 86.6% patients had vitamin D deficiency (≤20ng/ml) in asthenozoospermic group compared to 56.7% in the normozoospermic group. The study found that low vitamin D was associated with a fivefold increased risk of developing asthenozoospermia at 95% CI (2.74-8.99). Moreover, there was a positive significant correlation (r=0.285; p<0.001) between serum vitamin D level with total motility and progressive motility (r=0.232; p<0.001). Hence, the study suggests a significant association between asthenozoospermia and low vitamin D levels. However, clinical trials are warranted to further reinforce the findings.

In vitro characteristics of X- and Y-bearing ram spermatozoa sorted by bovine serum albumin (BSA) column and TLR7/8 ligand R848

The quality of the separated fractions in sex-sorted semen is very important for the success of the artificial insemination. This study aimed to evaluate some in vitro characteristics (DNA quantity, kinematic parameters and enzymes activity) of X- and Y-bearing ram spermatozoa sorted by bovine serum albumin (BSA) column and toll-like receptors (TLR)7/8 ligand R848. The ejaculates from six rams were collected by artificial vagina and subjected to a computer-assisted semen analysis (CASA). Total motility and percentage of the sperms with rapid and medium progressivity or non-progressivity in whole ejaculates and in X and Y fractions were analyzed. Activity of the enzymes ALP, GGT, CK, LDH and accumulation of lactate in the seminal plasma of ejaculates and in the environmental fluid of sexed spermatozoa were measured by biochemical analyzer. DNA was isolated from precipitated spermatozoa, and its quantity was measured. For both protocols the DNA mass from X-bearing fractions was higher, than from Y-bearing fractions. The high total motility of X- and Y-bearing spermatozoa as well as greater percent sperms with progressive motility were observed after use of BSA protocol. The application of TLR7/8 ligand R848 protocol led to reducing of Y-sperm motility and enhancement of non-progressivity in both fractions, which corresponded to the determined high amount of the extracellular lactate. For both methods, the significantly reduced activity of enzymes in the X and Y spermatozoa environmental fluids was established. Both protocols produce X- and Y-sperm fractions with satisfactory quality (over 80% total motility and over 50% rapid and medium progressive spermatozoa in each fraction).

Egg Yolk-Supplemented Tris-Citric Acid Extender Improves the Prefreezing and Post-Thaw Sperm Quality Indices of Guinea Pig (Cavia porcellus) Epididymal Spermatozoa

This study aimed to assess the suitability of egg yolk (EY) supplementation to a tris-citric acid-based extender on cryosurvival of guinea pig (Cavia porcellus) epididymal spermatozoa. Two synthetic-based extenders, tris-citric acid-glucose plus 20% EY (TCG-EY) and tris-citric acid-fructose (TCF) both with 5% glycerol, were compared. Thirty-two epididymides were recovered from 16 adult guinea pig males by gonadectomy, and then the sperm samples were retrieved by retrograde flushing using TCG-EY and TCF extenders for left or right epididymis, respectively. TCG-EY and TCF sperm samples were frozen in static liquid nitrogen vapors through a two-step cooling procedure. Before freezing, the percentage of progressive sperm motility and sperm with intact plasma and acrosome membranes from TCG-EY sperm samples were higher (p < 0.05) than those diluted with TCF. Post-thaw sperm kinematic variables and membrane integrity were drastically reduced (p < 0.001) compared with prefreezing samples, regardless of extender type. The post-thaw plasmatic and acrosome membrane integrity from TCG-EY sperm samples was higher (p < 0.05) than those from TCF samples. Except for the length, the morphometric head dimensions of sperm diluted with TCG-EY or TCF did not vary (p > 0.05) after the freezing-thawing process compared with the prefreezing samples. In conclusion, despite greater cell cryoinjury with both extenders, the EY supplementation exerted greater cell membrane protection before and after the freezing-thawing process. This research shows an in-depth analysis of guinea pig sperm cryopreservation; however, more studies are recommended.

Sperm traits and seminal plasma proteome of locally adapted hairy rams subjected to intermittent scrotal insulation

The present study evaluated the effects of heat stress on reproductive parameters of hairy rams. Six animals were subjected to scrotal insulation during four consecutive nights (6 PM - 6 AM). Day (D) 0 was the first day of insulation. Scrotal circumference increased from 30.5 ± 0.3 cm (at pre-insulation) to 31.8 ± 0.4 cm on D4, decreased 3.9 cm on D28, returning to 30.6 ± 0.6 cm on D57. Sperm concentration decreased from 3.7 ± 0.12 ×109 sperm/mL before insulation to 2.6 ± 0.1 ×109 on D23, returning to normal on D57. Sperm motility averaged 75 ± 2.9% before insulation, was undetectable on D23, and became normal on D77. Sperm with normal morphology reached 5.9 ± 2.6% on D35 but recovered (86.8 ± 2.1%) on D91. Sperm DNA integrity decreased from 86.5 ± 4.7% before insulation to 11.1 ± 3.7% on D63, returning to pre-insulation values on D120. Sperm BSP immunostaining was reduced after scrotal insulation. Variations in seminal protein abundances coincided with changes in sperm parameters. Seminal plasma superoxide dismutase, carboxypeptidase Q-precursor and NPC intracellular cholesterol transporter 2 decreased on D18, returning to normal after D28. Albumin, inhibitor of carbonic anhydrase precursor, EGF-like repeat and discoid I-like domain-containing protein 3 and polymeric immunoglobulin receptor increased after insulation. In summary, intermittent scrotal insulation drastically altered ram sperm attributes and seminal proteins, especially those associated with oxidative stress. Knowledge of animal´s response to thermal stress is vital in the scenario of climate changes.

Effect of exogenous melatonin implant on post-thaw semen quality of buffalo bulls

Melatonin is an intracellular antioxidant of sperm membrane that protects the cells from lipid peroxidation. Yet, its role as an antioxidant on semen quality of buffalo bulls is still obscure. The present study was undertaken to assess the effect of exogenous melatonin implant (18 mg/50 kg bodyweight) on post-thaw sperm characteristics, oxidative stress, endocrinological profiles and fertility of buffalo bulls. Six apparently healthy breeding Murrah buffalo bulls were randomly selected at bull farm, Guru Angad Dev Veterinary and Animal Sciences University for the present study and divided into two groups viz. control (n = 3) and melatonin implanted group (n = 3). A total of 120 ejaculates were collected from bulls of both groups (n = 60 each) throughout the study period. Most beneficial effects of melatonin implants were observed during post-implantation period. The percentages of post-thaw sperm total and progressive motility, viability and mitochondrial membrane potential were higher (p < .05) in melatonin implanted buffalo bulls compared to controls during post-implantation period. Following melatonin implantation, MDA production in post-thaw semen was lower (p < .05) in melatonin implanted group than in control group. Plasma melatonin and testosterone concentrations were higher (p < .05) in buffalo bulls implanted with melatonin as compared to their control counterparts. No differences (p > .05) in plasma LH concentrations were observed in both groups. First service pregnancy rate was 43.3% using semen of melatonin implanted bulls and 30.0% with semen of controls (p > .05). Thus, melatonin was able to protect sperm membrane against oxidative damage and improve post-thaw semen quality, thereby resulting in higher fertilizing potential of spermatozoa.

Factors affecting the analysis and interpretation of sperm quality in frozen/thawed stallion semen

In the current study, we examined: 1) the agreement (bias) between fluorescence-based methods (NucleoCounter-SP100 [NC] vs. flow cytometry [FC]) for determining the viability (VIAB) of frozen/thawed stallion sperm; 2) the agreement between post-thaw sperm total motility (TMOT) and VIAB; 3) whether a difference between TMOT and VIAB [VIAB - TMOT] in frozen/thawed stallion sperm could be explained by the level of lipid peroxidation in viable sperm (VLPP); 4) the repeatability of post-thaw analysis of sperm quality; and 5) the effect of final post-thaw semen dilution (10, 30, or 50 x 106 sperm/mL) on sperm motion characteristics. Post-thaw VIAB was similar between NC and FC (P > 0.05), and the agreement between these two methods was high (bias: 1 to -3). The agreement between post-thaw TMOT and VIAB decreased as the pre-freeze percentages of morphologically normal sperm and DNA quality decreased: bias - 4 to - 25. The bias between [VIAB - TMOT] and VLPP ranged from - 5 to 7. Differences in post-thaw sperm quality (TMOT, PMOT, VIAB, and sperm concentration) were not observed when analyzing one or three straws per ejaculate (P > 0.05). There was no effect of post-thaw sperm concentration (i.e., 10 vs. 30 vs. 50 x 106 sperm/mL) on sperm motion characteristics (P > 0.05). This study reports factors other than post-thaw sperm motility that warrant further consideration when analyzing frozen/thawed stallion sperm.

A Dietary Supplement Jinghuosu Ameliorates Reproductive Damage Induced by Tripterygium Glycosides

OBJECTIVE

To determine the possible protective effects of Jinghuosu, a dietary supplement (DS), on tripterygium glycosides (TG)-induced reproductive system injury in rats and its underlying mechanisms.

METHODS

A reproductive damage model was established in rats by feeding of TGs. Twenty-eight male Sprague Dawley rats were randomly divided into 4 groups using a random number table (n=7 in each): control (C) group, model (M) group, DS group and L-carnitine (LC) group. Rats in M, DS and LC groups received 40 mg/kg TGs orally. Starting from the 5th week, after administration of TGs for 4 h every day, rats in DS and LC groups were administered with 2.7 g/kg DS and 0.21 g/kg LC, respectively, for protective treatment over the next 4 weeks. Rats in Group C continued to receive the control treatment. Hematoxylin-eosin staining was used for histopathological analysis of rat testicular tissues. Enzyme-linked immunosorbent assay was performed to measure alkaline phosphatase (ALP), lactate dehydrogenase, alcohol dehydrogenase, total antioxidant capacity (T-AOC), superoxide dismutase, glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) concentrations. Chemiluminescence assay was used to determine the serum testosterone content. Quantitative real-time PCR and Western blotting were conducted to analyze the expression of genes and proteins related to the testosterone synthesis pathway and the nuclear factor erythroid 2-related factor 2/heme oxygenase 1 antioxidant pathway.

RESULTS

Oral administration of TGs induced significant increases in the testicular levels of zinc transporter 1 and MDA (P<0.05). On the other hand, sperm concentration, sperm motility, and serum testosterone, serum zinc, testicular zinc, Zrt-, Irt-like protein 1, ALP, luteinizing hormone (LH) receptor, steroidogenic acute regulatory protein, Cytochrome P450 family 11 subfamily A member 1, 3 β -hydroxysteroid dehydrogenase 1 T-AOC, GSH-Px, nuclear factor erythroid 2-related factor 2, heme oxygenase-1 and NAD (P)H: quinone oxidoreductase 1 levels decreased following TGs exposure (P<0.05). All of these phenotypes were evidently reversed by DS (P<0.05).

CONCLUSION

DS Jinghuosu protects against TG-induced reproductive system injury in rats, probably by improving zinc homeostasis, enhancing the testosterone synthesis and attenuating oxidative stress.

Automated Single-Sperm Selection Software (SiD) during ICSI: A Prospective Sibling Oocyte Evaluation

The computer-assisted program SiD was developed to assess and select sperm in real time based on motility characteristics. To date, there are limited studies examining the correlation between AI-assisted sperm selection and ICSI outcomes. To address this limit, a total of 646 sibling MII oocytes were randomly divided into two groups as follows: the ICSI group (n = 320): ICSI performed with sperm selected by the embryologist and the ICSI-SiD group (n = 326): ICSI performed with sperm selected using SiD software. Our results show a non-significant trend towards improved outcomes in the ICSI-SiD group across various biological parameters, including fertilization, cleavage, day 3 embryo development, blastocyst development, and quality on day 5. Similarly, we observed a non-significant increase in these outcomes when comparing both groups with sperm selection performed by a junior embryologist. Embryo development was monitored using a timelapse system. Some fertilization events happen significantly earlier when SiD is used for ICSI, but no significant difference was observed in the ICSI-SiD group for other timepoints. We observed comparable cumulative early and clinical pregnancy rates after ICSI-SiD. This preliminary investigation illustrated that employing the automated sperm selection software SiD leads to comparable biological outcomes, suggesting its efficacy in sperm selection.

Effect of Medicago sativa seed powder (Plus vitamin E vs. vitamin E alone) on semen analysis in men with idiopathic infertility: A double blind randomized clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Different parts of the alfalfa plant (Medicago sativa L.), especially its seeds, have been introduced as a semen quality enhancer in the folk medicine of different regions of Iran as well as in the traditional Persian medicine (PM) books. The seeds of this plant are also used in many combined medicines to treat male infertility in PM.

AIM OF THE STUDY

This study was designed to investigate the effect of M. sativa seed powder plus vitamin E vs. vitamin E alone on semen analysis of men with idiopathic infertility.

MATERIALS AND METHODS

In this randomized clinical trial, 60 participants were randomly divided into two groups and then received M. sativa seed powder (6 g daily) or placebo for three months, as add-on to vitamin E (100 U). Results of semen analysis (sperm total count, motility, and morphology as well as semen volume) of these two groups and their changes were compared before and after treatment as the primary outcome. The number of pregnancies after one month and probable side effects were also assessed.

RESULTS

After 12 weeks, sperm total count changed from 36.2 ± 21.8 × 106/ml to 48.5 ± 19.1 × 106/ml in M. sativa and from 39.5 ± 23.5 × 106/ml to 41.2 ± 20.9 × 106/ml in placebo, percentage of normal morphology changed from 1.8 ± 0.8% to 2.6 ± 1.2 % in M. sativa and from 2.0 ± 0.9% to 2.6 ± 1.2% in placebo and percentage of motile sperm changed from 36.5 ± 11.8 % to 39.7 ± 12.0% in M. sativa and from 39.3 ± 10.1 % to 38.1 ± 12.1% in placebo. The improvements in M. sativa group are significantly better than placebo group (P = 0.00, 0.01 and 0.04, respectively). However, semen volume decreased in both groups, but its changes were not significant. The number of pregnancies was four in the intervention and zero in placebo group. One case with abdominal bloating and one with respiratory allergy withdrew from the intervention group. No other adverse effect was reported.

CONCLUSIONS

In this study, significant improvement was detected in sperm parameters (except semen volume) of men with idiopathic infertility in M. sativa plus vitamin E group in compare to vitamin E alone after 12 weeks. These findings suggest that the M. sativa, as a complementary therapy, may have a beneficial effect on semen quality. More clinical trials with larger sample size are needed.

Effect of dressing with different antiseptic agents on reproductive parameters in rats undergoing abdominal incision

Antiseptic agents used in the postoperative period affect the functions of many tissues in the body, including the testicles. In this study, the effect of dressings administered with different antiseptic agents on testicular functions in rats that underwent abdominal incisions was investigated. A total of 48 Sprague-Dawley rats were used in the study. Each of the rats in the study group underwent a 4 cm-long skin and muscle operation. The incision was then stitched immediately. Antiseptics, hemp seed oil, hemp leaf oil, and cannabidiol oil were then administered to the rats for 10 days to provide antisepsis. The rats were sacrificed 24 hours after the last administration, and testicular tissues were removed. Testicular tissues were used for histopathological examination and biochemical analysis, while epididymal tissue was used for sperm analysis. According to the results, the MDA level in the antiseptic-administered group was higher than in the other experimental groups (p<0.05). Levels of SOD, CAT activities, and GSH content were found to be lower in the antiseptic group than in the hemp seed oil, hemp leaf oil, and cannabidiol oil groups (p<0.05). In testicular histology, the SEED group had the highest Johnsen score, and the antiseptic group had the lowest score (p<0.05). While JAK, P-JAK2, STAT3, PSTAT3, and NF-κB were generally higher in the antiseptic group compared to the other groups, they were lower in the SEED group. Additionally, sperm total motility rate and epididymal sperm density were highest in the SEED group (p<0.05). As a result, it was determined that cannabidiol seed oil had a good effect on testicular histology and sperm quality in male rats during the wound healing process.

Post-thaw quality of boar spermatozoa is affected by ejaculate fractions and extenders

The aim of this study was to investigate the effect of different extenders on the post-thaw (PT) quality of sperm originating from the sperm-rich fraction (SRF) and post-sperm-rich fraction (PSRF) of boar ejaculate. Motility and velocity parameters, analyzed using a computer-assisted semen analysis (CASA) system, and membrane integrity parameters were markedly higher in frozen-thawed (FT) spermatozoa of the SRF in both the Belstville Thawing Solution (BTS) and Androhep Plus (AHP) extenders, irrespective of the post-thaw (PT) storage time. Furthermore, reduced cryo-survival was more marked in FT spermatozoa of the PSRF in both extenders following storage for 60 min. It was found that the SRF-stored samples in the AHP extender for 60 min exhibited significantly higher percentages of spermatozoa with total motility, mitochondrial function and acrosome integrity than those stored in the BTS extender. The findings of this study confirm that components of the ejaculate fractions and extender have varying effects on the cryo-survival of boar spermatozoa.

Transcription factors and miRNA act as contrary regulators of gene expression in the testis and epididymis of Bos indicus animals

Spermatogenesis is highly conserved among mammalians, but its gene expression and regulatory profile are not entirely known. As transcription factors (TFs) and miRNAs are crucial for gene expression regulation, identifying genes negatively regulated by miRNAs and positively regulated by TFs in the testis and epididymis can provide a deeper understanding of gene expression and regulatory patterns. To do this, we used expression data coming from RNA-Seq and miRNA-Seq experiments made with biopsies from testicular parenchyma, head of the epididymis, and tail of the epididymis of four Brahman bulls. We identified miRNA differentially expressed (DE) by comparing the three distinct tissues. A co-expression analysis combined with a regulatory impact factor approach identified miRNAs and TFs with regulatory impact over gene expression regulation in the Bos indicus tissues studied. We identified 116 DE miRNAs, 206 miRNAs and 237 TFs with a significant regulatory impact on mRNA patterns in the tissues' comparisons. bta-miR-196b was the only DE miRNA for all tissue comparisons and it may be a regulator of spermatogenesis through its links with adipogenesis and insulin biosynthesis. DE genes and TFs involved in contrary regulations between the epididymis head and testis parenchyma were associated with spermatogenesis, sexual reproduction, and sperm motility. Our results provide possible mechanisms, governed by the contrary effect of miRNA and TF, leading to the differential expression between the studied tissues. We have demonstrated that our predictions of miRNAs and TFs co-regulations over target DE genes can retrieve known regulatory mechanisms and predict new ones that merit further validation.

Deleterious variant in FAM71D cause male infertility with asthenoteratospermia

Asthenoteratospermia is a significant cause of male infertility. FAM71D (Family with sequence similarity 71, member D), as a novel protein exclusively expressed in the testis, has been found to be associated with sperm motility. However, the association of FAM71D mutation with male infertility has yet to be examined. Here, we conducted whole-exome sequencing and identified a homozygous missense mutation c.440G > A (p. Arg147Gln) of FAM71D in an asthenoteratospermia-affected man from a consanguineous family. The FAM71D variant is extremely rare in human population genome databases and predicted to be deleterious by multiple bioinformatics tools. Semen analysis indicated decreased sperm motility and obvious morphological abnormalities in sperm cells from the FAM71D-deficient man. Immunofluorescence assays revealed that the identified FAM71D mutation had an important influence on the assembly of sperm structure-related proteins. Furthermore, intra-cytoplasmic sperm injection (ICSI) treatment performed on the infertile man with FAM71D variant achieved a satisfactory outcome. Overall, our study identified FAM71D as a novel causative gene for male infertility with asthenoteratospermia, for which ICSI treatment may be suggested to acquire good prognosis. All these findings will provide effective guidance for genetic counselling and assisted reproduction treatments of asthenoteratospermia-affected subjects.

Relationship of environmental exposure temperature and temperature extremes on sperm DNA fragmentation index in men with different BMI values and the indirect effect of DNA fragmentation index on semen parameters

Prior studies have established a significant correlation between the DNA fragmentation index (DFI) and infertility. Additionally, certain investigations suggest that environmental exposure may serve as an etiological factor impacting semen quality. This study aimed to explore the impact of season, ambient temperature, and weather extremes on the DFI of sperm, along with other relevant parameters. Furthermore, it sought to assess how ambient temperature affects the DFI of sperm and other semen parameters in populations with varying BMI values. Additionally, the study analyzed the transient indirect effect of DFI on sperm parameters. This retrospective study analyzed semen samples from 11,877 men, selected based on female factor considerations, spanning from January 2016 to December 2021. Participants were grouped according to the season of semen collection. The results showed that samples collected in summer had a lower semen volume and sperm motility, while those collected in autumn had a lower DFI. We analyzed the exposure-response ratio between environmental exposure temperature and semen parameters using a generalized additive model. Results showed that the curve of the exposure-response relationship was U-shaped or inverted U-shaped; when the air temperature exposure was below the threshold, for each degree of temperature increase, the total sperm motility, sperm concentration, and progressive motility increased by 0.16 %, 0.29 × 10 (Levine, 1999)/ml and 0.14 %, respectively, while the DFI and inactivity rate decreased by 0.078 % and 0.15 %, respectively. When the air temperature exposure exceeded the threshold, for each degree of temperature increase, the sperm concentration, total sperm motility, semen volume and progressive motility decreased by 0.42 × 10 (Levine, 1999)/ml, 0.11 %, 0.0078 ml and 0.15 %, respectively, while the DFI and inactivity rate increased by 0.13 % and 0.12 %, respectively. Extremely cold weather during spermatogenesis was positively correlated with DFI, and extremely hot weather was negatively correlated with sperm motility. Subgroup analysis revealed that individuals classified as overweight / obese exhibited more pronounced changes in sperm parameters and the DFI in response to variations in environmental exposure temperature compared to those with a normal BMI. In the analysis of the relationship between DFI and sperm parameters, the results showed an inverted U-shape relationship between DFI and semen volume, and a negative correlation between DFI and sperm concentration and sperm motility. And we found that ambient temperature affects sperm parameters through DFI at low as well as average temperatures, whereas at high temperatures this indirect effect is no longer present.

The beneficial effect of Allium Cepa bulb extract on reproduction of rats; A two-generation study on fecundity and sex hormones

Allium Cepa Linn. (Onions) has extensively been used in traditional medicine, is one of the important Allium species regularly used in our daily diet, and has been the source of robust phenolic compounds. The current study is intended to evaluate the fecundity-enhancing effect of A. Cepa on the reproductive performance of two successive generations of rats; F0 and F1. A. Cepa extract was initially tested for in vitro antioxidant assay via DPPH and ROS, followed by in vivo toxicity testing. In the fecundity assessment, eighteen pairs of male and female rats (n = 36, 1:1, F0 generation) were divided into three groups and dosed with 75mg/kg and 150 mg/kg daily of A. Cepa extract and saline respectively, up to pre-cohabitation, cohabitation, gestation and lactation period. The reproductive performance, including body weight, live birth index, fertility index, and litter size, was assessed. Various parameters like Hematological, Hormonal (FSH, LH, Testosterone, estradiol), antioxidant markers (SOD, Glutathione peroxidase) and lipid profile of F0 and F1 generations were assessed with evaluation of histopathology of male and female organs. Ethanolic extract of A. Cepa showed the greatest antioxidant potential in DPPH and ROS methods. The continued exposure of the F0 and F1 generations to A. Cepa extract did not affect body weight, fertility index, litter size, and survival index. However, semen pH, sperm motility, sperm count, sperm viability, and semen volume were significantly improved in both generations. We have found pronounced fecundity outcomes in both genders of F0 and F1 generations with A. Cepa 150mg/kg/day extract as compared to control. Results showed that A. Cepa significantly increased (P < 0.05) hemoglobin, follicular stimulating hormone (FSH), luteinizing hormone (LH), plasma testosterone and glutathione peroxidase activities, while total lipid, LDL, and cholesterol were significantly decreased (P < 0.05) in both generations. Histology of both generations of animals reveals enhanced spermatogenesis and enhanced folliculogenesis with improved architecture. Altogether, the present results suggest that A. Cepa extract improved fecundity in both male and female rats by improving hormonal activities and oxidative stress.

Bio-inspired progressive motile sperm separation using joint rheotaxis and boundary-following behavior

Infertility, as a daunting ever-increasing challenge, poses a worldwide issue to both couples and the healthcare sector. According to the World Health Organization, half of infertility cases are attributed to male factor infertility, either partly or completely. Semen parameters of concern including sperm count, morphology, and motility are deemed to play a vital role in the insemination process. Density gradient centrifugation, being a clinically established procedure for improving on the mentioned parameters, has long been proven to inflict damage on the DNA content of the sperm cells, inducing DNA fragmentation. Herein, a bio-inspired microfluidic device is proposed that capitalizes on the geometry of the uterotubal junction (UTJ) of the female reproductive tract, which can act as a rheological barrier. The device leverages sperm rheotaxis and boundary-following behavior which have been considered as major migratory mechanisms used by sperm during the fertilization process in the female body. The device consists of a series of parallel channels that guide progressive motile sperms into the main sorting channel, where the hydrodynamic barriers created by two consecutive UTJ-like constrictions select sperms based on their propulsive velocity and linearity of motion. The sequential sorting employed here allows for the fractionation of the sperm population into two subpopulations with varying degrees of motility. Both sorted populations showed a significant increase in straight line velocity, reaching 63.4 ± 14.4 μm s-1 and 74 ± 13.8 μm s-1 in the first and second pools, respectively from 35.2 ± 27.2 μm s-1 in raw semen. Additionally, sorted populations demonstrated over 30% reduction in DNA fragmentation index, an indication that the proposed device selects for undamaged sperms with high quality. Apart from the biological superiority of the sorted sperms, this device presents itself as an easy and clinically-applicable method for the separation of progressive motile sperms, while at the same time, benefiting from a straightforward procedure for sperm retrieval.

Birth by caesarean section and semen quality in adulthood: a Danish population-based cohort study

BACKGROUND

The caesarean section (CS) rate has increased worldwide and there is an increasing public and scientific interest in the potential long-term health consequences for the offspring. CS is related to persistent aberrant microbiota colonization in the offspring, which may negatively interfere with sex hormone homeostasis and thus potentially affect the reproductive health. It remains unknown whether adult sons' semen quality is affected by CS. We hypothesize that CS is associated with lower semen quality.

METHODS

This study was based on the Fetal Programming of Semen Quality cohort (FEPOS, enrolled from 2017 to 2019) nested within the Danish National Birth Cohort (DNBC, enrolled from 1996 to 2002). A total of 5697 adult sons of mothers from the DNBC were invited to the FEPOS cohort, and 1044 young men participated in this study. Information on mode of delivery was extracted from the Danish Medical Birth Registry, and included vaginal delivery, elective CS before labor, emergency CS during labor and unspecified CS. The young men provided a semen sample for analysis of semen volume, sperm concentration, motility and morphology. Negative binomial regression models were applied to examine the association between CS and semen characteristics with estimation of relative differences in percentages with 95% confidence intervals (CIs).

RESULTS

Among included sons, 132 (13%) were born by CS. We found a slightly lower non-progressive sperm motility (reflecting higher progressive sperm motility) among sons born by CS compared to sons born by vaginal delivery [relative difference (95% CI): - 7.5% (- 14.1% to - 0.4%)]. No differences were observed for other sperm characteristics. When CS was further classified into elective CS, emergency CS and unspecified CS in a sensitivity analysis, no significant differences in non-progressive motility were observed among sons born by any of the three types of CS compared to sons born vaginally.

CONCLUSIONS

This large population-based cohort study found no significant evidence for an adverse effect on semen quality in adult sons born by CS.

Decreased AdipoR1 signaling and its implications for obesity-induced male infertility

Obesity is among the risk factors for male infertility. Although several mechanisms underlying obesity-induced male subfertility have been reported, the entire mechanism of obesity-induced male infertility still remains unclear. Here, we show that sperm count, sperm motility and sperm fertilizing ability were decreased in male mice fed a high-fat diet and that the expression of the AdipoR1 gene and protein was decreased, and the expression of pro-apoptotic genes and protein increased, in the testis from mice fed a high-fat diet. Moreover, we demonstrate that testes weight, sperm count, sperm motility and sperm fertilizing ability were significantly decreased in AdipoR1 knockout mice compared to those in wild-type mice; furthermore, the phosphorylation of AMPK was decreased, and the expression of pro-apoptotic genes and proteins, caspase-6 activity and pathologically apoptotic seminiferous tubules were increased, in the testis from AdipoR1 knockout mice. Furthermore, study findings show that orally administrated AdipoRon decreased caspase-6 activity and apoptotic seminiferous tubules in the testis, thus ameliorating sperm motility in male mice fed a high-fat diet. This was the first study to demonstrate that decreased AdipoR1/AMPK signaling led to increased caspase-6 activity/increased apoptosis in the testis thus likely accounting for male infertility.

Tektin bundle interacting protein, TEKTIP1, functions to stabilize the tektin bundle and axoneme in mouse sperm flagella

Tektins are microtubule inner proteins (MIPs) and localize at the inside lumen of doublet microtubules (DMTs) of cilia/flagella. TEKTIP1, a newly identified protein by cryo-electron microscopy (cryo-EM), is proposed to be localized at the center of the tektin bundle and hypothesized to recruit tektins or stabilize the bundle. However, the physiological role of TEKTIP1 is unknown. In this study, we generated Tektip1-knockout (Tektip1-/-) mice and showed that they were male subfertile primarily due to reduced sperm motility. A high percentage of sperm from Tektip1-/- mice showed moderately disorganized axoneme structures and abnormal flagellar waveforms. TEKTIP1 predominately interacted with TEKT3 among tektins. Loss of TEKTIP1 partially disturbed the organization of tektin bundle by mainly affecting the native status of TEKT3 and its interaction with other tektins. Collectively, our study reveals the physiological role and potential molecular mechanism of TEKTIP1 in axonemal structure and sperm motility, highlights the importance of MIPs in stabilizing DMTs, and suggests a potential relevance of TEKTIP1 deficiency to human asthenospermia. Tektip1-/- mice will be an excellent animal model to study the DMT organization of sperm flagella using cryo-EM in future.

Effects of nanotubes on semen quality and fertility in humans: A systematic review of literature

BACKGROUND

In the medical field, it is increasingly common to observe the use of nanotubes, for example, in the administration of drugs. However, nanotubes raise concerns for male fertility due to potential effects on hormone levels and sperm quality observed in animal studies. In addition, animal exposure to multi-walled carbon nanotube models found alterations in hormone levels, sperm motility, and sperm count. Limited evidence in humans suggests no adverse effects, but further research is needed. This study aimed to perform a systematic review to assess the in vitro effects of nanotubes on semen and fertility in humans.

METHODS

We included all published in vitro studies about semen or sperm or male fertility and nanotubes in humans. A search was conducted in LILACS, PubMed, and SCOPUS as of May 2023. The risk of bias was assessed using the QUIN tool.

RESULTS

Four studies using nanotubes on human sperm were included, nanotubes exposure appears not to affect sperm viability; however, some alterations to motility, velocity and production of reactive oxygen species were reported. Limited evidence is provided because of the small quantity of publications.

CONCLUSIONS

Nanotubes appear to have no adverse effects on human sperm.

The deleterious effects of sofosbuvir and ribavirin (antiviral drugs against hepatitis C virus) on different body systems in male albino rats regarding reproductive, hematological, biochemical, hepatic, and renal profiles and histopathological changes

Sofosbuvir is one of the crucial drugs used in the treatment of chronic hepatitis C virus (HCV) in adults and children with compensated liver disease, including cirrhosis. It may be used alone or with other drugs. Ribavirin is an antiviral medication used to treat HCV infection. It is not effective when used alone and must be used in combination with other medications, such as sofosbuvir. This study pertains to a comprehensive assessment of the deleterious effects of sofosbuvir (an antiviral drug against chronic HCV) or sofosbuvir combined with ribavirin (an antiviral drug against RNA and DNA viruses) on several biological activities of the body, including hematological, hormonal, biochemical, histological, and immunohistochemical examinations during a long-standing period on male healthy rats. In addition, fertility assessments were performed, including sperm collections and semen parameter investigations. This study was conducted on 21 male rats divided into three equal groups. Group I (control group) received distilled water; group II (sofosbuvir group) received sofosbuvir (4 mg/kg); and group III (sofosbuvir + ribavirin) received sofosbuvir (4 mg/kg) plus ribavirin (30 ml/kg). All groups received the specific drug for six months. Blood and tissue samples were collected for hematological, hormonal, biochemical, histological, and immunohistochemical examinations. In addition, sperm collection and assessments of semen parameters were performed. Results revealed that sofosbuvir causes a highly significant decrease in the mean of most hematological, immunological, hormonal, and biochemical parameters, except for a few numbers of parameters such as neutrophils, monocytes, basophils, cortisol, GOT, and lipase, which exhibit a significant increase. The same occurred in the sofosbuvir + ribavirin group, but at much higher levels, as most hematological, immunological, hormonal, and biochemical parameters exhibit a highly significant decrease except for monocytes, triglyceride, and lipase, which exhibit a significant increase. When compared to the sofosbuvir group alone, the sofosbuvir + ribavirin group demonstrated a highly significant decline in the mean of most hematological, immunological, hormonal, and biochemical parameters except lymphocytes and triglycerides, which exhibit a substantial increase. For the reproductive parameters, both groups exhibit a significant decrease in the total sperm motility percentage. Finally, it can be concluded that sofosbuvir causes acute pancreatitis and combined immunodeficiency. Ribavirin is associated with hormonal deficiency, which indicates the occurrence of hypopituitarism. Moreover, sofosbuvir and ribavirin synergistically affect myelosuppression and cause iron-deficiency anemia. However, sofosbuvir, or its combination with ribavirin, is associated with a reduced risk of hepatocellular carcinoma. Besides, adding ribavirin to be combined with sofosbuvir improved the immunodeficiency caused by sofosbuvir; this confirms that using ribavirin with sofosbuvir reduces the side effects of both alone.

Flagellar beating forces of human spermatozoa with different motility behaviors

BACKGROUND

One of the causes of male infertility is associated with altered spermatozoa motility. These sperm features are frequently analyzed by image-based approaches, which, despite allowing the acquisition of crucial parameters to assess sperm motility, they are unable to provide details regarding the flagellar beating forces, which have been neglected until now.

RESULTS

In this work we exploit Fluidic Force Microscopy to investigate and quantify the forces associated with the flagellar beating frequencies of human spermatozoa. The analysis is performed on two groups divided according to the progressive motility of semen samples, as identified by standard clinical protocols. In the first group, 100% of the spermatozoa swim linearly (100% progressive motility), while, in the other, spermatozoa show both linear and circular motility (identified as 80 - 20% progressive motility). Significant differences in flagellar beating forces between spermatozoa from semen sample with different progressive motility are observed. Particularly, linear motile spermatozoa exhibit forces higher than those with a circular movement.

CONCLUSIONS

This research can increase our understanding of sperm motility and the role of mechanics in fertilization, which could help us unveil some of the causes of idiopathic male infertility.