The Proteome of Large or Small Extracellular Vesicles in Pig Seminal Plasma Differs, Defining Sources and Biological Functions.

Seminal plasma contains many morphologically heterogeneous extracellular vesicles (sEVs). These are sequentially released by cells of the testis, epididymis, and accessory sex glands and involved in male and female reproductive processes. This study aimed to define in depth sEV subsets isolated by ultrafiltration and size exclusion chromatography, decode their proteomic profiles using liquid chromatography-tandem mass spectrometry, and quantify identified proteins using sequential window acquisition of all theoretical mass spectra. The sEV subsets were defined as large (L-EVs) or small (S-EVs) by their protein concentration, morphology, size distribution, and EV-specific protein markers and purity. Liquid chromatography-tandem mass spectrometry identified a total of 1034 proteins, 737 of them quantified by SWATH in S-EVs, L-EVs, and non-EVs-enriched samples (18-20 size exclusion chromatography-eluted fractions). The differential expression analysis revealed 197 differentially abundant proteins between both EV subsets, S-EVs and L-EVs, and 37 and 199 between S-EVs and L-EVs versus non-EVs-enriched samples, respectively. The gene ontology enrichment analysis of differentially abundant proteins suggested, based on the type of protein detected, that S-EVs could be mainly released through an apocrine blebbing pathway and be involved in modulating the immune environment of the female reproductive tract as well as during sperm-oocyte interaction. In contrast, L-EVs could be released by fusion of multivesicular bodies with the plasma membrane becoming involved in sperm physiological processes, such as capacitation and avoidance of oxidative stress. In conclusion, this study provides a procedure capable of isolating subsets of EVs from pig seminal plasma with a high degree of purity and shows differences in the proteomic profile between EV subsets, indicating different sources and biological functions for the sEVs.

Viral Load Dynamics in Plasma and Semen When Antiretroviral Therapy Is Initiated During Early HIV-1 Infection.

We assessed human immunodeficiency virus (HIV) load in plasma and semen during primary HIV infection using serial samples of semen and plasma during the first 24 weeks after diagnosis in untreated participants and those who started antiretroviral therapy (ART) immediately at diagnosis. In the absence of treatment, semen viral load was >1000 copies/mL in almost all specimens (83%) collected 2-10 weeks after the estimated date of HIV acquisition and remained >1000 copies/mL in 35% of untreated participants at the last observed time point. Thus, in the absence of ART, semen viral load remained at a level consistent with transmissibility throughout primary infection.

Proteomics is advancing the understanding of stallion sperm biology.

The mammalian ejaculate is very well suited to proteomics studies. As such, research concerning sperm proteomics is offering a huge amount of new information on the biology of spermatozoa. Among domestic animals, horses represent a species of special interest, in which reproductive technologies and a sizeable market of genetic material have grown exponentially in the last decade. Studies using proteomic approaches have been conducted in recent years, showing that proteomics is a potent tool to dig into the biology of the stallion spermatozoa. The aim of this review is to present an overview of the research conducted, and how these studies have improved our knowledge of stallion sperm biology. The main outcomes of the research conducted so far have been an improved knowledge of metabolism, and its importance in sperm functions, the impact of different technologies on the sperm proteome, and the identification of potential biomarkers. Moreover, proteomics of seminal plasma and phosphoproteomics are identified as areas of major interest.

Proteomics and Metabolic Characteristics of Boar Seminal Plasma Extracellular Vesicles Reveal Biomarker Candidates Related to Sperm Motility.

Although seminal plasma extracellular vesicles (SPEVs) play important roles in sperm function, little is known about their metabolite compositions and roles in sperm motility. Here, we performed metabolomics and proteomics analysis of boar SPEVs with high or low sperm motility to investigate specific biomarkers affecting sperm motility. In total, 140 proteins and 32 metabolites were obtained through differentially expressed analysis and weighted gene coexpression network analysis (WGCNA). Seven differentially expressed proteins (DEPs) (ADIRF, EPS8L1, PRCP, CD81, PTPRD, CSK, LOC100736569) and six differentially expressed metabolites (DEMs) (adenosine, beclomethasone, 1,2-benzenedicarboxylic acid, urea, 1-methyl-l-histidine, and palmitic acid) were also identified in WGCNA significant modules. Joint pathway analysis revealed that three DEPs (GART, ADCY7, and NTPCR) and two DEMs (urea and adenosine) were involved in purine metabolism. Our results suggested that there was significant correlation between proteins and metabolites, such as IL4I1 and urea (r = 0.86). Furthermore, we detected the expression level of GART, ADCY7, and CDC42 in sperm of two groups, which further verified the experimental results. This study revealed that several proteins and metabolites in SPEVs play important roles in sperm motility. Our results offered new insights into the complex mechanism of sperm motility and identified potential biomarkers for male reproductive diseases.

Site-specific N-glycoproteomic analysis reveals up-regulated fucosylation in seminal plasma of asthenozoospermia.

N-linked glycoproteins are rich in seminal plasma, playing essential roles in supporting sperm function and fertilization process. The alteration of seminal plasma glycans and its correspond glycoproteins may lead to sperm dysfunction and even infertility. In present study, an integrative analysis of glycoproteomic and proteomic was performed to investigate the changes of site-specific glycans and glycoptoteins in seminal plasma of asthenozoospermia. By large scale profiling and quantifying 5,018 intact N-glycopeptides in seminal plasma, we identified 92 intact N-glycopeptides from 34 glycoproteins changed in asthenozoospermia. Especially, fucosylated glycans containing lewis x, lewis y and core fucosylation were significantly up-regulated in asthenozoospermia compared to healthy donors. The up-regulation of fucosylated glycans in seminal plasma may interfere sperm surface compositions and regulation of immune response, which subsequently disrupts sperm function. Three differentiated expression of seminal vesicle-specific glycoproteins (fibronectin, seminogelin-2, and glycodelin) were also detected with fucosylation alteration in seminal plasma of asthenozoospermia. The interpretation of the altered site-specific glycan structures provides data for the diagnosis and etiology analysis of male infertility, as well as providing new insights into the potential therapeutic targets for male infertility.

Prostate-specific membrane antigen (PSMA) glycoforms in prostate cancer patients seminal plasma.

INTRODUCTION: Prostate-specific membrane antigen (PSMA) is a US Food and Drug Administration-approved theranostic target for prostate cancer (PCa). Although PSMA is known to be glycosylated, the composition and functional roles of its N-linked glycoforms have not been fully characterized. METHODS: PSMA was isolated from pooled seminal plasma from low-risk grade Groups 1 and 2 PCa patients. Intact glycopeptides were analyzed by mass spectrometry to identify site-specific glycoforms. RESULTS: We observed a rich distribution of PSMA glycoforms in seminal plasma from low and low-intermediate-risk PCa patients. Some interesting generalities can be drawn based on the predicted topology of PSMA on the plasma membrane. The glycoforms at ASN-459, ASN-476, and ASN-638 residues that are located at the basal domain facing the plasma membrane in cells, are predominantly high mannose glycans. ASN-76 which is located in the interdomain region adjacent to the apical domain of the protein shows a mixture of high mannose glycans and complex glycans, whereas ASN-121, ASN-195 and ASN-336 that are located and are exposed at the apical domain of the protein predominantly possess complex sialylated and fucosylated N-linked glycans. These highly accessible glycosites display the greatest diversity in isoforms across the patient samples. CONCLUSIONS: Our study provides novel qualitative insights into PSMA glycoforms that are present in the seminal fluid of PCa patients. The presence of a rich diversity of glycoforms in seminal plasma provides untapped potential for glycoprotein biomarker discovery and as a clinical sample for noninvasive diagnostics of male urological disorders and diseases including PCa. Specifically, our glycomics approach will be critical in uncovering PSMA glycoforms with utility in staging and risk stratification of PCa.

LGALS3 cfDNA methylation in seminal fluid as a novel prostate cancer biomarker outperforming PSA.

BACKGROUND: The unmet challenge in prostate cancer (PCa) management is to discriminate it from benign prostate hyperplasia (BPH) due to the lack of specific diagnostic biomarkers. Contemporary research on potential PCa biomarkers is directed toward methylated cell-free DNA (cfDNA) from liquid biopsies since epigenetic mechanisms are strongly involved in PCa development. METHODS: In the present research, cfDNA methylation of the LGALS3 gene in blood and seminal plasma of PCa and BPH patients was assessed using pyrosequencing, as well as LGALS3 DNA methylation in tissue biopsies. Liquid biopsy samples were taken from patients with clinical suspicion of PCa, who were subsequently divided into two groups, that is, 42 with PCa and 55 with BPH, according to the histopathological analysis. RESULTS: Statistically significant higher cfDNA methylation of LGALS3 in seminal plasma of BPH than in PCa patients was detected by pyrosequencing. ROC curve analysis showed that it could distinguish PCa and BPH patients with 56.4% sensitivity and 70.4% specificity, while PSA did not differ between the two patient groups. In contrast, there was no statistically significant difference in LGALS3 cfDNA methylation in blood plasma between the two patient groups. In prostate tumor tissue, there was a statistically significant DNA hypermethylation of LGALS3 compared to surrounding nontumor tissue and BPH tissue. CONCLUSIONS: The DNA hypermethylation of the LGALS3 gene represents an event specific to PCa development. In conclusion, LGALS3 cfDNA methylation in seminal fluid discriminates early PCa and BPH presenting itself as a powerful novel PCa biomarker highly outperforming PSA.

In vivo effect of vaginal seminal plasma application on the human endometrial transcriptome: a randomized controlled trial.

Studies in humans and animals suggest that seminal plasma, the acellular seminal fluid component, stimulates the endometrium to promote immune tolerance and facilitate implantation. We designed a randomized, double-blinded, placebo-controlled trial to investigate changes in the endometrial transcriptomic profile after vaginal application of seminal plasma. The study participants were randomized into two groups. Five women received a vaginal application of seminal plasma, and four received a placebo application with saline solution. The application was performed 2 days after HCG-triggered ovulation in an unstimulated cycle. After 5-8 days, an endometrial biopsy was collected to analyze differences in the endometrial transcriptomic profile using microarray analyses. A differential gene expression analysis and a gene set analysis were performed. The gene set enrichment analysis showed a positive enrichment of pathways associated with the immune response, cell viability, proliferation, and cellular movement. Moreover, pathways involved in implantation, embryo development, oocyte maturation, and angiogenesis were positively enriched. The differential gene expression analysis, after adjusting for multiple testing, showed no significantly differentially expressed genes between the two groups. A comparative analysis was also performed with similar studies conducted in other animals or in vitro using human endometrial cells. The comparative analysis showed that the effect of seminal plasma effect on the endometrium is similar in pigs, mice, and in vitro human endometrial cells. The present study provides evidence that seminal plasma might impact the endometrium during the implantation window, with potential to affect endometrial receptivity and embryo development.

Both protein and non-protein components in extracellular vesicles of human seminal plasma improve human sperm function via CatSper-mediated calcium signaling.

STUDY QUESTION: What is the significance and mechanism of human seminal plasma extracellular vesicles (EVs) in regulating human sperm functions? SUMMARY ANSWER: EV increases the intracellular Ca2+ concentrations [Ca2+]i via extracellular Ca2+ influx by activating CatSper channels, and subsequently modulate human sperm motility, especially hyperactivated motility, which is attributed to both protein and non-protein components in EV. WHAT IS KNOWN ALREADY: EVs are functional regulators of human sperm function, and EV cargoes from normal and asthenozoospermic seminal plasma are different. Pre-fusion of EV with sperm in the acidic and non-physiological sucrose buffer solution could elevate [Ca2+]i in human sperm. CatSper, a principle Ca2+ channel in human sperm, is responsible for the [Ca2+]i regulation when sperm respond to diverse extracellular stimuli. However, the role of CatSper in EV-evoked calcium signaling and its potential physiological significance remain unclear. STUDY DESIGN, SIZE, DURATION: EV isolated from the seminal plasma of normal and asthenozoospermic semen were utilized to investigate the mechanism by which EV regulates calcium signal in human sperm, including the involvement of CatSper and the responsible cargoes in EV. In addition, the clinical application potential of EV and EV protein-derived peptides were also evaluated. This is a laboratory study that went on for more than 5 years and involved more than 200 separate experiments. PARTICIPANTS/MATERIALS, SETTING, METHODS: Semen donors were recruited in accordance with the Institutional Ethics Committee on human subjects of the Affiliated Hospital of Nantong University and Jiangxi Maternal and Child Health Hospital. The Flow NanoAnalyzer, western blotting, and transmission electron microscope were used to systematically characterize seminal plasma EV. Sperm [Ca2+]i responses were examined by fluorimetric measurement. The whole-cell patch-clamp technique was performed to record CatSper currents. Sperm motility parameters were assessed by computer-assisted sperm analysis. Sperm hyperactivation was also evaluated by examining their penetration ability in viscous methylcellulose media. Protein and non-protein components in EV were analyzed by liquid chromatography-mass spectrum. The levels of prostaglandins, reactive oxygen species, malonaldehyde, and DNA integrity were detected by commercial kits. MAIN RESULTS AND THE ROLE OF CHANCE: EV increased [Ca2+]i via an extracellular Ca2+ influx, which could be suppressed by a CatSper inhibitor. Also, EV potentiated CatSper currents in human sperm. Furthermore, the EV-in [Ca2+]i increase and CatSper currents were absent in a CatSper-deficient sperm, confirming the crucial role of CatSper in EV induced Ca2+ signaling in human sperm. Both proteins and non-protein components of EV contributed to the increase of [Ca2+]i, which were important for the effects of EV on human sperm. Consequently, EV and its cargos promoted sperm hyperactivated motility. In addition, seminal plasma EV protein-derived peptides, such as NAT1-derived peptide (N-P) and THBS-1-derived peptide (T-P), could activate the sperm calcium signal and enhance sperm function. Interestingly, EV derived from asthenozoospermic semen caused a lower increase of [Ca2+]i than that isolated from normal seminal plasma (N-EV), and N-EV significantly improved sperm motility and function in both asthenozoospermic samples and frozen-thawed sperm. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: This was an in vitro study and caution must be taken when extrapolating the physiological relevance to in vivo regulation of sperm. WIDER IMPLICATIONS OF THE FINDINGS: Our findings demonstrate that the CatSper-mediated-Ca2+ signaling is involved in EV-modulated sperm function under near physiological conditions, and EV and their derivates are a novel CatSper and sperm function regulators with potential for clinical application. They may be developed to improve sperm motility resulting from low [Ca2+]i response and/or freezing and thawing. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by the National Natural Science Foundation of China (32271167), the Social Development Project of Jiangsu Province (BE2022765), the Nantong Social and People's Livelihood Science and Technology Plan (MS22022087), the Basic Science Research Program of Nantong (JC22022086), and the Jiangsu Innovation and Entrepreneurship Talent Plan (JSSCRC2021543). The authors declare no conflict of interest.

Analysis of 12 kinds of cytokines in seminal plasma by flow cytometry and their correlations with routine semen parameters.

OBJECTIVE: To investigate the levels of 12 kinds of cytokines in seminal plasma and their correlations with routine semen parameters. METHODS: The remaining seminal plasma samples of 134 patients undergoing routine semen examination were collected for detecting cytokines. The parameters for sperm concentration, percentage of progressively motile sperm (PR), and motility were analyzed by a computer-assisted sperm analysis (CASA) system. According to the results of sperm concentration, PR and motility, 134 patients were divided into the normal routine semen parameters group, oligoasthenospermia group and azoospermia group. The levels of 12 kinds of cytokines in seminal plasma, including interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12P70, IL-17, interferin (IFN)-α, IFN-γ, and tumor necrosis factor (TNF)-α, were detected by flow cytometry. Two seminal plasma samples were detected for 10 times, respectively, to calculate the coefficients of variation (CV) of each cytokine. The linear range of each cytokine was measured using the standard, and the correlation coefficient (r) was calculated. RESULTS: The r2 of 12 kinds of cytokines detected by flow cytometry were all greater than 0.99. The reproducibility of 2 seminal plasma samples showed that the CVs of all cytokines were lower than 15 % except for TNF-α in sample 1 (15.15 %). Seminal plasma IL-6 levels were negatively correlated with semen volume (P < 0.01). Seminal plasma IL-5 levels were positively correlated with sperm concentration (P < 0.01). Seminal plasma IL-8 levels were negatively correlated with sperm motility (P < 0.01). Seminal plasma IL-8, IL-17 and IL-12P70 levels were negatively correlated with sperm PR (P < 0.05). In addition to the significant negative correlation between IL-5 and IL-17 (P < 0.05), there was a significant positive correlation between the majority of other cytokines. The levels of seminal plasma IL-17 and IL-12P70 in the oligoasthenospermia group and IL-1ß and IL-12P70 in the azoospermia group were significantly higher than those in the normal routine semen parameters group (P ≤ 0.05), while the levels of IL-10 in the azoospermia group were significantly lower than that in the normal routine semen parameters group (P < 0.05). CONCLUSION: There are certain correlations between seminal plasma cytokines and routine semen parameters and strong correlations between different seminal plasma cytokines, suggesting that the imbalance between seminal plasma cytokines may affect sperm quality. However, it still needs to be further confirmed by large samples and multi-center clinical studies and related basic researches.

Screening of cytokine expression in human seminal plasma in associations with sperm disorders and markers of oxidative-antioxidant balance.

Among the many factors with a proven relation to semen quality and male fertility, the determination of seminal plasma cytokines provides a promising direction for research into the identification of factors connected with male infertility. The interleukins: IL-1α, -1ß, -2, -4, -6, -8, -10, -12p40, -12p70, -18, IFNγ, and GM-CSF, total oxidant (TOS) and antioxidant (TAS) status, were simultaneously examined in seminal plasmas and blood sera in terato- (n = 32), asthenoterato- (n = 33), and oligoasthenoteratozoospermic (n = 29) infertile men and in normozoospermic fertile men (n = 20). Our research shows different cytokine composition of the sera and seminal plasmas in all studied groups, along with much higher concentrations of seminal plasma GM-CSF, IFNγ, IL-1α, IL-4, IL-6, and IL-8 and lower IL-18 and TOS in the comparison to their sera levels. The seminal plasma concentrations of GM-CSF, IFNγ, IL-1α, -4, and -6 differ significantly between fertile and infertile as well as between teratozoospermic, asthenoteratozoospermic, and oligoasthenoteratozoospermic groups. The indication of the cause of different concentrations of cytokines in seminal plasmas of infertile men, and their associations with semen parameters and oxidative status, may be a promising direction for the search for new therapeutic targets that would directly affect the cells and tissues of male reproductive organs.

Lipidomics random forest algorithm of seminal plasma is a promising method for enhancing the diagnosis of necrozoospermia.

BACKGROUND: Despite the clear clinical diagnostic criteria for necrozoospermia in andrology, the fundamental mechanisms underlying it remain elusive. This study aims to profile the lipid composition in seminal plasma systematically and to ascertain the potential of lipid biomarkers in the accurate diagnosis of necrozoospermia. It also evaluates the efficacy of a lipidomics-based random forest algorithm model in identifying necrozoospermia. METHODS: Seminal plasma samples were collected from patients diagnosed with necrozoospermia (n = 28) and normozoospermia (n = 28). Liquid chromatography-mass spectrometry (LC-MS) was used to perform lipidomic analysis and identify the underlying biomarkers. A lipid functional enrichment analysis was conducted using the LION lipid ontology database. The top 100 differentially significant lipids were subjected to lipid biomarker examination through random forest machine learning model. RESULTS: Lipidomic analysis identified 46 lipid classes comprising 1267 lipid metabolites in seminal plasma. The top five enriched lipid functions as follows: fatty acid (FA) with ≤ 18 carbons, FA with 16-18 carbons, monounsaturated FA, FA with 18 carbons, and FA with 16 carbons. The top 100 differentially significant lipids were subjected to machine learning analysis and identified 20 feature lipids. The random forest model identified lipids with an area under the curve > 0.8, including LPE(20:4) and TG(4:0_14:1_16:0). CONCLUSIONS: LPE(20:4) and TG(4:0_14:1_16:0), were identified as differential lipids for necrozoospermia. Seminal plasma lipidomic analysis could provide valuable biochemical information for the diagnosis of necrozoospermia, and its combination with conventional sperm analysis may improve the accuracy and reliability of the diagnosis.

Immunophenotype profile by flow cytometry reveals different subtypes of extracellular vesicles in porcine seminal plasma.

BACKGROUND: Porcine seminal plasma (SP) is endowed with a heterogeneous population of extracellular vesicles (sEVs). This study evaluated the immunophenotypic profile by high-sensitivity flow cytometry of eight sEV subpopulations isolated according to their size (small [S-sEVs] and large [L-sEVs]) from four different SP sources, namely three ejaculate fractions (the first 10 mL of the sperm rich fraction [SRF-P1], the remaining SRF [SRF-P2], and the post-SRF [PSRF]) and entire ejaculate (EE). METHODS: Seminal EVs were isolated using a size exclusion chromatography-based protocol from six SP pools (five ejaculates/pool) of each SP source and characterized using complementary approaches including total protein (BCA™assay), particle size distribution (dynamic light scattering), morphology (transmission electron microscopy), and purity (albumin by Western blot). Expression of CD9, CD63, CD81, CD44 and HSP90ß was analyzed in all sEV subpopulations by high-sensitivity flow cytometry according to MIFlowCyt-EV guidelines, including an accurate calibration, controls, and discrimination by CFSE-labelling. RESULTS: Each sEV subpopulation exhibited a specific immunophenotypic profile. The percentage of sEVs positive for CD9, CD63, CD81 and HSP90ß differed between S- and L-sEVs (P < 0.0001). Specifically, the percentage of sEVs positive for CD9 and CD63 was higher and that for CD81 was lower in S- than L-sEVs in the four SP sources. However, the percentage of HSP90ß-positive sEVs was lower in S-sEVs than L-sEVs in the SRF-P1 and EE samples. The percentage of sEVs positive for CD9, CD63, and CD44 also differed among the four SP sources (P < 0.0001), being highest in PSRF samples. Notably, virtually all sEV subpopulations expressed CD44 (range: 88.04-98.50%). CONCLUSIONS: This study demonstrated the utility of high-sensitivity flow cytometry for sEV immunophenotyping, allowing the identification of distinct sEV subpopulations that may have different cellular origin, cargo, functions, and target cells.

A systematic review identifying seminal plasma biomarkers and their predictive ability on IVF and ICSI outcomes.

The diverse nature and high molecule concentration of seminal plasma (SP) makes this fluid a good potential source for a potential biomarker that could predict assisted reproductive technology (ART) outcomes. Currently, semen quality parameters cannot accurately predict ART outcomes. A systematic literature search was conducted to identify human SP biomarkers with potential predictive ability for the outcomes of IVF and intracytoplasmic sperm injection. Observational cohort and case-control studies describing the association between biomarkers in human SP and the outcome of infertile men attending for ART were included. Forty-three studies were selected, reporting on 89 potential SP biomarkers (grouped as oxidative stress, proteins glycoproteins, metabolites, immune system components, metals and trace elements and nucleic acids). The present review supports 32 molecules in SP as potentially relevant biomarkers for predicting ART outcomes; 23 molecules were reported once and nine molecules were reported in more than one study; IL-18 and TGF-ß1-IL-18 ratio were confirmed in distinct studies. This review presents the most comprehensive overview of relevant SP biomarkers to predict ART outcomes to date, which is of clinical interest for infertility investigations and assisted reproduction; nevertheless, its potential is under-exploited. This review could serve as starting point for designing an all-encompassing study for biomarkers in SP and their predictive ability for ART outcomes, and for developing a non-invasive diagnostic tool.

Exposome Profiling of Environmental Pollutants in Seminal Plasma and Novel Associations with Semen Parameters.

Indicators of male fertility are in decline globally, but the underlying causes, including the role of environmental exposures, are unclear. This study aimed to examine organic chemical pollutants in seminal plasma, including both known priority environmental chemicals and less studied chemicals, to identify uncharacterized male reproductive environmental toxicants. Semen samples were collected from 100 individuals and assessed for sperm concentration, percent motility, and total motile sperm. Targeted and nontargeted organic pollutant exposures were measured from seminal plasma using gas chromatography, which showed widespread detection of organic pollutants in seminal plasma across all exposure classes. We used principal component pursuit (PCP) on our targeted panel and derived one component (driven by etriadizole) associated with total motile sperm (p < 0.001) and concentration (p = 0.03). This was confirmed by the exposome-wide association models using individual chemicals, where etriadizole was negatively associated with total motile sperm (FDR q = 0.01) and concentration (q = 0.07). Using PCP on 814 nontargeted spectral peaks identified a component that was associated with total motile sperm (p = 0.001). Bayesian kernel machine regression identified one principal driver of this association, which was analytically confirmed to be N-nitrosodiethylamine. These findings are promising and consistent with experimental evidence showing that etridiazole and N-nitrosodiethylamine may be reproductive toxicants.

Effects of natural mating, artificial insemination and intravaginal deposition of raw semen or seminal plasma on vaginal and uterine blood flow in German Holstein cows.

AIM: The present study was performed to characterize and compare the perfusion of vaginal and uterine arteries after challenging the reproductive tract of dairy cows via natural mating, artificial insemination (AI), or intravaginal deposition (vaginal fundus) of different biological fluids or a placebo. MATERIALS AND METHODS: In a double-blind study, six German Holstein cows were administered PGF2α during dioestrus and 48 h later treated with GnRH. Intravaginal or intrauterine treatments were carried out 12 h after GnRH was administered. Animals served as their controls, using a cross-over design with an interval of 14 days between experiments. The experimental animals were allocated to receive the following treatments: natural mating (N), intrauterine artificial insemination (A), intravaginal deposition (vaginal fundus) of 6 mL raw semen (R) or 6 mL seminal plasma (S), and compared to their controls [control 1: 6 mL placebo (P: physiological saline); control 2: no treatment (C)). Corresponding time intervals were chosen for the untreated control oestrus. Blood flow volume (BFV) in the uterine (u) and vaginal (v) arteries ipsilateral to the ovary bearing the preovulatory follicle was determined using transrectal Doppler sonography. RESULTS: All animals exhibited oestrus and ovulated between 30 and 36 h after GnRH. Transient increases (P < 0.05) in vaginal blood flow occurred between 3 and 12 h following mating as well as 3 to 9 h after deposition of raw semen and seminal plasma, respectively. The most distinct increases (199%) in vBFV occurred 6 h after mating compared to values immediately before mating (= time 0 h). Neither AI nor deposition of a placebo into the vagina affected vBFV (P > 0.05). Only mating and deposition of either raw semen, seminal plasma or AI increased uBFV (P < 0.003). The greatest rise in uBFV occurred after natural mating. Maximum uBFV values were detected 9 h after mating when values were 79% greater (P < 0.05) than at 0 h. CONCLUSIONS: The natural mating, deposition of raw semen or seminal plasma and conventional AI affect vaginal and/or uterine blood flow to different degrees. The factors responsible for these alterations in blood flow and their effects on fertility remain to be clarified in future studies.

Associations between seminal plasma metals/metalloids and semen quality: A cross-sectional study.

Exposure to metals/metalloids is reported to potentially influence semen quality. While most studies have focused on single metal impacts, the link between exposure to multiple metals and semen quality has remained less explored. The study aimed to investigate the effects of both individual and mixed metal/metalloid exposure on semen quality. A total of 330 men were recruited from three reproductive centers in eastern China. Seminal plasma levels of 25 metals/metalloids and sperm parameters were determined. We used the Generalized Linear Model (GLM) and Restricted Cubic Spline (RCS) to assess the relationships between single metals/metalloids and semen quality. The weighted quantile sum (WQS) models were then applied to evaluate the combined effect of all these metals/metalloids. We observed positive associations of exposure to lithium (Li), zinc (Zn), and magnesium (Mg) with an increased risk of below reference values for progressive motility and total motility using a logistic regression model (P < 0.05). Additionally, our results also revealed a significant inverse relationship between aluminum (Al) and both sperm concentration and count, while cobalt (Co) demonstrated a positive association with sperm concentration (P < 0.05). Notably, the WQS model indicated a significant positive association between exposure to metal/metalloid mixtures and the risk of abnormal progressive motility (OR: 1.57; 95%CI: 1.10, 2.24) and abnormal total motility (OR: 1.53; 95%CI: 1.06, 2.19), with this association primarily driven by Li, Mg, and Zn. In summary, our findings indicate that exposure to metal/metalloid mixtures might have an adverse effect on semen quality.

Physiological evaluation of seasonal sperm quality in a biannual spawner, Pacific abalone: Effects on in-vitro fertilization and cryotolerance.

Pacific abalone, Haliotis discus hannai, is a highly valuable gastropod mollusk commonly found in Southeast Asia. The present study aims to analyze the seminal plasma quality, sperm quality, and cryotolerance of the Pacific abalone sperm during its reproductive season. The seminal plasma quality was evaluated by analyzing biochemical and metabolite composition, enzymatic activity (superoxide dismutase, catalase, and glutathione), and lipid peroxidation (LPO) activity. The sperm quality was evaluated by analyzing motility, concentration, volume, ATP content, acrosome integrity (AI), plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), DNA integrity, and fertilization potential. The cryotolerance capacity was evaluated by analyzing post-thaw motility, AI, PMI, MMP, and DNA integrity. Seminal plasma osmolarity was significantly higher (1123.3 ± 1.5 mOsmL-1) in May compared to other reproductive periods, with Cl- (516.8 ± 0.5 mM) and Na+ (460.2 ± 0.4 mM) as the dominant ions. The seminal plasma pH remained constant at 6.8 throughout the reproductive season. Improved enzymatic activity and lower LPO were detected in May or June. Sperm quality indicators were similar in May and June, except for sperm production. The fertilization potential (May: 93.0 ± 4.4%, June: 86.0 ± 7.2%) and hatching rate (May: 86.6 ± 5.78%, June: 82.3 ± 3.2%) of Pacific abalone were significantly higher in May or June than they were in other reproductive seasons. The motility (May: 50.19 ± 2.35%, June: 49.96 ± 1.60%), AI (May: 44.02 ± 3.46%, June: 42.16 ± 3.61%), PMI (May: 54.12 ± 3.29%, June: 52.82 ± 2.58%), and MMP (May: 44.02 ± 3.46%, June: 42.16 ± 3.61%) of the cryopreserved sperm were similar in May and June compared with those preserved in other reproductive seasons. The DNA integrity of the cryopreserved sperm was similar in May (80.3 ± 6.7%) or June (78.9 ± 7.4%) and had a higher cryotolerance than in other reproductive seasons. Hence, it can be suggested that May and/or June are suitable periods for sperm physiology experiments, artificial reproduction, and sperm cryopreservation of Pacific abalone.

Association between levels of insulin-like growth factor-1 in serum and seminal plasma with fresh and frozen-thawed semen characteristics in Beetal bucks.

The aim of this study was to investigate the relationship between the levels of insulin-like growth factor-1 (IGF-1) in serum and seminal plasma and the characteristics of semen in Beetal bucks (Capra hircus). A total of 12 adult Beetal bucks were involved in the study, with each buck providing six ejaculates collected using a standard artificial vagina (n = 72 total). Only qualified semen samples (volume of 0.7 mL, a mass motility rating of 3+ or higher on a 0-+ scale, and individual progressive motility of 80% or more) divided into three fractions were processed for estimation of IGF-1 and other seminal parameters like motility, viability, acrosome integrity, sperm abnormality and superoxide dismutase (SOD) activity. The first and second fraction were diluted and extended with Optixcell extender (1:15 ratio). The first ejaculate fraction was processed for studying fresh semen parameters and the second fraction was cryopreserved for evaluating frozen semen parameters. French mini straws (0.25 mL) were used for semen filling, and polyvinyl alcohol powder of different colours was used for sealing the extended semen. The third fraction of each ejaculate was centrifuged at room temperature (1100 × g for 7 min) to separate the seminal plasma. Additionally, blood samples were taken from each buck on the same day as semen collection, resulting in a total of 36 blood samples. The results revealed a significant positive correlation (r = .4243; p < .05) between the concentration of IGF-1 in both serum and seminal plasma of the Beetal bucks. Furthermore, the concentration of IGF-1 in serum showed significant positive correlations with sperm viability (r = .554; p < .05), acrosome integrity (r = .527; p < .05), post-thaw sperm motility (r = .407; p < .01), post-thaw sperm viability (r = .426; p < .01) and post-thaw acrosome integrity (r = .333; p < .05). However, it had a significant negative correlation with SOD activity in fresh semen (r = -0.458; p < .01). Moreover, the concentration of IGF-1 in seminal plasma demonstrated significant positive correlations with individual progressive motility (r = .341; p < .05), sperm viability (r = .527; p < .05), acrosome integrity (r = .539; p < .05), sperm plasma membrane integrity (r = .464; p < .05), post-thaw sperm motility (r = .644; p < .01), post-thaw sperm viability (r = .643; p < .01), post-thaw acrosome integrity (r = .487; p < .01) and post-thaw sperm plasma membrane integrity (r = .521; p < .01). Additionally, it showed a significant negative correlation with SOD activity in both fresh semen (r = -0.714; p < .01) and frozen semen (r = -0.558; p < .01) of Beetal bucks. Based on these findings, IGF-1 in seminal plasma can be considered as a potential biomarker for the selection of bucks for breeding purposes.

Quantitative Analysis of the Human Semen Phosphorometabolome by 31P-NMR.

Phosphorus-containing metabolites occupy a prominent position in cell pathways. The phosphorometabolomic approach in human sperm samples will deliver valuable information as new male fertility biomarkers could emerge. This study analyzed, by 31P-NMR, seminal plasma and whole semen from asthenozoospermic and normozoospermic samples (71% vs. 27% and 45% vs. 17%, total and progressive sperm motility, respectively), and also ejaculates from healthy donors. At least 16 phosphorus-containing metabolites involved in central energy metabolism and phospholipid, nucleotide, and nicotinamide metabolic pathways were assigned and different abundances between the samples with distinct sperm quality was detected. Specifically, higher levels of phosphocholine, glucose-1-phosphate, and to a lesser degree, acetyl phosphate were found in the asthenozoospermic seminal plasma. Notably, the phosphorometabolites implicated in lipid metabolism were highlighted in the seminal plasma, while those associated with carbohydrate metabolism were more abundant in the spermatozoa. Higher levels of phosphocholine, glucose-1-phosphate, and acetyl phosphate in the seminal plasma with poor quality suggest their crucial role in supporting sperm motility through energy metabolic pathways. In the seminal plasma, phosphorometabolites related to lipid metabolism were prominent; however, spermatozoa metabolism is more dependent on carbohydrate-related energy pathways. Understanding the presence and function of sperm phosphorylated metabolites will enhance our knowledge of the metabolic profile of healthy human sperm, improving assessment and differential diagnosis.