ORIGINAL ARTICLE: The Role of Cytokine Expression in Different Subgroups of Subfertile Men

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)-1β, 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-1β 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.

The Association Between the Levels of Oxidative Stress Indicators (MDA, SOD, and GSH) in Seminal Plasma and the Risk of Idiopathic Oligo-asthenotera-tozoospermia: Does Cu or Se Level Alter the Association?

Epidemiological studies on the associations between the levels of oxidative stress (OS) indicators (MDA, SOD, and GSH) in seminal plasma and the risk of idiopathic oligo-asthenotera-tozoospermia (OAT) are still inconsistent. Additionally, whether the associations can be altered by the status of essential trace elements is still unknown. To investigate the relationship between MDA, SOD, and GSH levels in seminal plasma and the risk of idiopathic OAT, and further to examine whether levels of iron (Fe), copper (Cu), and selenium (Se) in seminal plasma can alter the associations. A total of 148 subjects (75 idiopathic OAT cases and 73 controls) were included in this study. Seminal plasma samples from all the participants were measured for levels of MDA, SOD, GSH, Fe, Cu, and Se. Unconditional logistic regression models were used to examine the associations between three oxidative stress indicators and the risk of idiopathic OAT. Bayesian kernel machine regression was performed to determine the joint effects of levels of three OS indicators on the risk of idiopathic OAT. Subgroup analyses were performed to explore whether the above associations can be different when Fe, Cu, and Se were in different levels. The level of MDA in seminal plasma was positively associated with the risk of idiopathic OAT, with adjusted odds ratio (OR) and 95% confidence interval (CI) of 2.38 (1.17, 4.83), and SOD and GSH levels were not associated with the risk of idiopathic OAT. In BKMR analyses, we found a significant positive association between the mixture of MDA, SOD, and GSH levels and the risk of idiopathic OAT at concentrations below the 65th percentile, while a negative association at concentrations above it. In subgroup analysis, a positive association was observed between MDA levels in seminal plasma and the risk of idiopathic OAT in the high-Cu group (adjusted OR = 3.66, 95%CI = 1.16, 11.57), while no significant association was found in the low-Cu group (adjusted OR = 1.43, 95%CI = 0.44, 4.58). Additionally, a negative association was found between GSH levels in seminal plasma and the risk of idiopathic OAT in the high-Se group (adjusted OR = 0.34, 95%CI = 0.11, 0.99), while no significant association was observed in the low-Se group (adjusted OR = 1.96, 95%CI = 0.46, 8.27). The levels of MDA, SOD, and GSH in seminal plasma were associated with the risk of idiopathic OAT, and the levels of Cu and Se in seminal plasma may alter the associations.

Leukocytospermia and/or Bacteriospermia: Impact on Male Infertility

Infertility is a globally underestimated public health concern affecting almost 190 million people, i.e., about 17.5% of people during their lifetime, while the prevalence of male factor infertility is about 7%. Among numerous other causes, the prevalence of male genital tract infections reportedly ranges between 10% and 35%. Leukocytospermia is found in 30% of infertile men and up to 20% in fertile men. Bacterial infections cause an inflammatory response attracting leukocytes, which produce reactive oxygen species (ROS) and release cytokines, both of which can cause damage to sperm, rendering them dysfunctional. Although leukocytospermia and bacteriospermia are both clinical conditions that can negatively affect male fertility, there is still debate about their impact on assisted reproduction outcomes and management. According to World Health Organization (WHO) guidelines, leukocytes should be determined by means of the Endtz test or with monoclonal antibodies against CD15, CD68 or CD22. The cut-off value proposed by the WHO is 1 × 106 peroxidase-positive cells/mL. For bacteria, Gram staining and semen culture are regarded as the "gold standard", while modern techniques such as PCR and next-generation sequencing (NGS) are allowing clinicians to detect a wider range of pathogens. Whereas the WHO manual does not specify a specific value as a cut-off for bacterial contamination, several studies consider semen samples with more than 103 colony-forming units (cfu)/mL as bacteriospermic. The pathogenic mechanisms leading to sperm dysfunction include direct interaction of bacteria with the male germ cells, bacterial release of spermatotoxic substances, induction of pro-inflammatory cytokines and ROS, all of which lead to oxidative stress. Clinically, bacterial infections, including "silent" infections, are treatable, with antibiotics being the treatment of choice. Yet, non-steroidal antiphlogistics or antioxidants should also be considered to alleviate inflammatory lesions and improve semen quality. In an assisted reproduction set up, sperm separation techniques significantly reduce the bacterial load in the semen. Nonetheless, contamination of the semen sample with skin commensals should be prevented by applying relevant hygiene techniques. In patients where leukocytospermia is detected, the causes (e.g. infection, inflammation, varicocele, smoking, etc.) of the leukocyte infiltration have to be identified and addressed with antibiotics, anti-inflammatories or antioxidants in cases where high oxidative stress levels are detected. However, no specific strategy is available for the management of leukocytospermia. Therefore, the relationship between bacteriospermia and leukocytospermia as well as their specific impact on functional sperm parameters and reproductive outcome variables such as fertilization or clinical pregnancy must be further investigated. The aim of this narrative review is to provide an update on the current knowledge on leukocytospermia and bacteriospermia and their impact on male fertility.

PLCζ, WBP2NL and TNF-α expression in spermatozoa is associated with stallion fertility and seminal quality?

This study aims to investigate the gene expression of sperm-borne phospholipase C zeta (PLCζ), WW domain-binding protein 2N-Terminal Like (WBP2NL), and Tumor necrosis factor (TNF-α), as a negative control, in spermatozoa and their relationship with fertility and seminal quality in stallions. Ejaculates from 40 Criollo stallions were used, whose fertility was assessed on the basis of their pregnancy rate per cycle in at least two breeding seasons. Pregnancy rates ranged from 20% to 90% and were used to divide the stallions into two groups: High rates (≥ 50%) (n = 25), and Low rates (< 50%) (n = 15). A computer-assisted sperm analysis system - (CASA) analyzed semen after collection. Also were evaluated the physical and functional integrity of the plasmatic membrane and sperm morphology alterations. All stallions expressed PLCζ, WBP2NL, and TNF-α. PLCζ positively correlates with conception rate, total motility (TM), progressive motility (PM), plasmatic membrane functionality, and integrity. A simple linear regression was detected between pregnancy rate and PLCζ expression (P = 0.003), TM (P < 0.001) and PM (P < 0.001). PLCζ gene expression was higher (P = 0,012) in the High rates group than in the Low group. WBP2NL and TNF-α did not correlate with seminal quality and stallion's fertility. It was concluded that PLCζ gene expression in the spermatozoa might be used as a biomarker of fertility and seminal quality in stallions. Parameters of sperm kinetics also showed, positive correlation between TM, PM and pregnancy rate.

Sleep apnea syndrome associated with gonadal hormone imbalance (Review)

Patients with obstructive sleep apnea exhibit an increased risk of developing gonadal disorders. Because a notable number of people worldwide have sleep respiratory and reproductive disorders, it is essential to recognize the association between local upper airway dysfunction and its gonadal effects. Repeated breathing pauses cause sleep fragmentation, disorganization of sleep cycles and stages, sympathetic activation, intermittent hypoxemia and systemic inflammation. Nocturnal intermittent hypoxemia has a direct central effect on neurotransmitters, with disturbances in the normal production of hypothalamic-pituitary hormones. Awakenings and micro-awakenings at the end of apneic episodes produce a central stress responsible for hormonal changes and subsequent endocrine imbalances. The aim of the present study was to investigate the impact of obstructive sleep apnea syndrome (OSAS) on gonadal hormonal homeostasis and its consequences. Recognizing and understanding how local upper airway dysfunction causes gonadal imbalance may facilitate better care for patients with OSAS. Although there may be a direct relationship between sleep-disordered breathing and gonadal function mediated by hormones via the hypothalamic-pituitary-gonadal axis, to date, current therapies have not been effective.

A review on immunological aspects in male reproduction: An immune cells and cytokines

The male reproductive system, particularly the male gamete, offers a unique barrier to the immune system. The growing germ cells in the testis need to be shielded from autoimmune damage. Hence the testis has to establish and sustain an immune-privileged milieu. Sertoli cells create this safe space, protected by the blood-testis barrier. Cytokines are a type of immune reaction that can positively and negatively affect male reproductive health. Inflammation, disease, and obesity are just a few physiological conditions for which cytokines mediate signals. They interact with steroidogenesis, shaping the adrenals and testes to produce the hormones needed for survival. In particular pathological condition, including autoimmune disorders, contains high levels of the same cytokines in semen that play an essential role in the immunomodulation of the male gonad. This review focuses on understanding the immunological role of cytokines in the control and development of male reproduction. Also, in maintaining male reproductive health and diseases linked with their aberrant function in the testis.

UBR4 deficiency causes male sterility and testis abnormal in Drosophila

Introduction

It has been established that UBR4 encodes E3 ubiquitin ligase, which determines the specificity of substrate binding during protein ubiquitination and has been associated with various functions of the nervous system but not the reproductive system. Herein, we explored the role of UBR4 on fertility with a Drosophila model.

Methods

Different Ubr4 knockdown flies were established using the UAS/GAL4 activating sequence system. Fertility, hatchability, and testis morphology were studied, and bioinformatics analyses were conducted. Our results indicated that UBR4 deficiency could induce male sterility and influent egg hatchability in Drosophila.

Results

We found that Ubr4 deficiency affected the testis during morphological analysis. Proteomics analysis indicated 188 upregulated proteins and 175 downregulated proteins in the testis of Ubr4 knockdown flies. Gene Ontology analysis revealed significant upregulation of CG11598 and Sfp65A, and downregulation of Pelota in Ubr4 knockdown flies. These proteins were involved in the biometabolic or reproductive process in Drosophila. These regulated proteins are important in testis generation and sperm storage promotion. Bioinformatics analysis verified that UBR4 was low expressed in cryptorchidism patients, which further supported the important role of UBR4 in male fertility.

Discussion

Overall, our findings suggest that UBR4 deficiency could promote male infertility and may be involved in the protein modification of UBR4 by upregulating Sfp65A and CG11598, whereas downregulating Pelota protein expression.

Effectiveness of non-pharmaceutical intervention on sperm quality: a systematic review and network meta-analysis

Infertility affects about 10% of the world's population and has been recognized by the WHO as a global public health problem. The aim of this network meta-analysis was to investigate the efficacy of non-pharmaceutical interventions on sperm quality. All randomized clinical trials (RCTs) from the PubMed, MEDLINE, Embase, China national knowledge infrastructure (CNKI), Wanfang database, and Cochrane Library databases evaluating the effectiveness of non-pharmaceutical interventions on semen parameters using network meta-analyses. Results of the ω-3 fatty acid, lycopene, acupuncture, and vitamin suggested evident advantages in improving sperm concentration (MD, 9.93 (95% CI, 7.21 to 12.65)), (MD, 8.79 (95% CI, 2.67 to 14.91)), (MD, 5.40 (95% CI, 2.32 to 8.49)) and (MD, 3.82 (95% CI, 0.70 to 6.94) respectively). Acupuncture has a significant advantage over placebo in improving sperm total motility (MD, 17.81 (95% CI, 10.32 to 25.29)), and the effect of lycopene was obviously greater than that of placebo (MD, 19.91 (95% CI, 2.99 to 36.83)). Lycopene, Coenzyme Q10 (CoQ10), acupuncture, ω-3 fatty acid, and vitamin suggested significant advantages in improving sperm forward motility (MD, 8.64 (95% CI, 1.15 to 16.13), MD, 5.28 (95% CI, 2.70 to 7.86), MD, 3.95 (95% CI, 3.23 to 4.67), MD, 3.50 (95% CI, 2.21 to 4.79)) and (MD, 2.38 (95% CI, 0.96 to 3.80) respectively). This review establishes that non-pharmaceutical interventions, particularly acupuncture, exercise, lycopene, ω-3 fatty acids, CoQ10, zinc, vitamins, selenium, carnitine, or foods rich in these supplements, profitably improve sperm quality that may be used to treat male infertility.

The Impact of Non-Andrological Medications on Semen Characteristics, Oxidative Stress and Inflammatory Parameters

Background and Objectives: The aim of this study was to evaluate the impact of medications on oxidative stress, inflammatory biomarkers and semen characteristics in males with idiopathic infertility. Materials and Methods: In this observational case-control clinical study, 50 men with idiopathic infertility were enrolled, of whom 38 (the study group) were on pharmacological treatment and 12 made up the control group. The study group was clustered according to the medications (Group A: anti-hypertensive, n = 10; Group B: thyroxine, n = 6; Group C: non-steroidal anti-inflammatory drugs, n = 13; Group D: miscellaneous, n = 6; Group E: lipid-lowering drugs, n = 4). Semen analyses were performed according to WHO 2010 guidelines. Interleukins (IL)-10, IL-1 beta, IL-4, IL-6, Tumor Necrosis Factor- alpha (TNF-alpha) and IL-1 alpha were determined using a solid-phase sandwich immunoassay. The diacron reactive oxygen metabolites, d-ROMs test, was performed by means of a colorimetric determination of reactive oxygen metabolites and measured with a spectrophotometer. Beta-2-microglobulin and cystatin-C were measured with an immunoturbidimetric analyzer. Results: No differences between the study and control groups for age and macroscopic and microscopic semen characteristics were found, nor were any differences found after clustering according to the drug categories. IL-1 alpha and IL-10 were significantly lower in the study group compared with the control group; IL-10 was significantly lower in groups A, B, C and D compared with the control group. Furthermore, a direct correlation between IL-1 alpha, IL-10 and TNF-alpha and leukocytes was found. Conclusions: Despite the sample size limitations, the data suggest a correlation between drug use and activation of the inflammatory response. This could clarify the pathogenic mechanism of action for several pharmacological classes on male infertility.

Evaluation of tenofovir disoproxil fumarate loaded silver nanoparticle on testicular morphology in experimental type-2 diabetic rats

Reproductive derangement and metabolic disorders in human immunodeficiency virus (HIV) infected persons require a nanoparticle delivery system to convey antiretroviral drugs to the anatomical sanctuary such as testis. This study investigated the effects of tenofovir disoproxil fumarate (TDF) loaded silver nanoparticles (AgNPs) on the testicular oxidative stress, inflammatory cytokines and histology in male diabetic rats. Thirty-six Sprague-Dawley rats weighing 230 ± 20 g were randomly divided into diabetic and non-diabetic groups (n = 18). Diabetes was induced using the fructose-streptozotocin (Frt-STZ) rat model. Both groups were further divided into three (n = 6) and administered distilled water, TDF, or TDF-AgNP. Results obtained with the TDF-AgNP administration showed a significant increase (p < .05) in the reduced glutathione and catalase levels. Tumour necrosis factor-alpha and interleukin 6 were reduced in diabetic rats administered TDF-AgNP. More so, administration of TDF-AgNP to diabetic rats improved testicular histoarchitecture in diabetic rats. In addition, diabetic rats administered TDF-AgNP showed a significant reduction (p < .05) in blood glucose levels. TDF-AgNP to diabetic rats enhanced testicular antioxidant enzyme, reduced testicular inflammation, and alleviated structural derangements in the testis. Thus, the application of AgNP to deliver TDF may alleviate testicular toxicity and subsequently cater for neglected reproductive dysfunction during the management of HIV infection.

High-Risk HPV with Multiple Infections Promotes CYP2E1, Lipoperoxidation and Pro-Inflammatory Cytokines in Semen of Asymptomatic Infertile Men

High-risk human papillomavirus (HR-HPV) infection, followed by chronic inflammation and oxidative stress, is a major risk factor of male infertility. In this study, we explored the potential impact of high-risk (HR) HPV genotypes in single infection (SI) and multiple infections (MI) that promote CYP2E1 expression, oxidative damage and pro-inflammatory cytokines, possibly contributing to sperm damage and male infertility. Semen samples from 101 infertile military men were studied. We analyzed seminal parameters, namely, HPV genotyping, cytochrome P450 2E1 (CYP2E1), oxidative stress biomarkers (total antioxidant capacity (TAC), catalase (CAT) and superoxide dismutase (SOD)), lipid peroxidation (LPO), 8-hydroxiguanosine (8-OHdG) and pro-inflammatory cytokines (IFN-γ, IL-1β, IL-4, IL-6 and IL-8). Eighty-one men (80.2%, 81/101) were positive for HPV infection, and MI-HR-HPV was higher than SI-HR-HPV (63% vs. 37%). HPV-52 was the most frequently detected type (18.5%), followed by HPV-33 (11.1%), and the most frequent combination of genotypes detected was HPV-33,52 (11.1%), followed by HPV-18,31 (6.2%). The group with infected samples presented lower normal morphology and antioxidant levels compared to non-infected samples. In concordance, the infected group showed high levels of LPO, IFN-γ, IL-1β, IL-4 and IL-6 and downregulation of CAT and SOD enzymes. Interestingly, changes in motility B, low levels of TAC, overexpression of CYP2E1, LPO and IL-8 levels were higher in MI-HR-HPV than SI-HR-HPV, suggesting that HPV infection promotes a chronic inflammatory process and a toxic and oxidative microenvironment, which increases with MI-HPV infections.

Measuring Reactive Oxygen Species in Semen for Male Preconception Care: A Scientist Perspective

Oxidative stress and elevated levels of seminal and sperm reactive oxygen species (ROS) may contribute to up to 80% of male infertility diagnosis, with sperm ROS concentrations at fertilization important in the development of a healthy fetus and child. The evaluation of ROS in semen seems promising as a potential diagnostic tool for male infertility and male preconception care with a number of clinically available tests on the market (MiOXSYS, luminol chemiluminescence and OxiSperm). While some of these tests show promise for clinical use, discrepancies in documented decision limits and lack of cohort studies/clinical trials assessing their benefits on fertilization rates, embryo development, pregnancy and live birth rates limit their current clinical utility. In this review, we provide an update on the current techniques used for analyzing semen ROS concentrations clinically, the potential to use of ROS research tools for improving clinical ROS detection in sperm and describe why we believe we are likely still a long way away before semen ROS concentrations might become a mainstream preconception diagnostic test in men.

High-fat Diet Alters Male Seminal Plasma Composition to Impair Female Immune Adaptation for Pregnancy in Mice

Paternal experiences and exposures before conception can influence fetal development and offspring phenotype. The composition of seminal plasma contributes to paternal programming effects through modulating the female reproductive tract immune response after mating. To investigate whether paternal obesity affects seminal plasma immune-regulatory activity, C57Bl/6 male mice were fed an obesogenic high-fat diet (HFD) or control diet (CD) for 14 weeks. Although HFD consumption caused only minor changes to parameters of sperm quality, the volume of seminal vesicle fluid secretions was increased by 65%, and the concentrations and total content of immune-regulatory TGF-β isoforms were decreased by 75% to 80% and 43% to 55%, respectively. Mating with BALB/c females revealed differences in the strength and properties of the postmating immune response elicited. Transcriptional analysis showed >300 inflammatory genes were similarly regulated in the uterine endometrium by mating independently of paternal diet, and 13 were dysregulated by HFD-fed compared with CD-fed males. Seminal vesicle fluid factors reduced in HFD-fed males, including TGF-β1, IL-10, and TNF, were among the predicted upstream regulators of differentially regulated genes. Additionally, the T-cell response induced by mating with CD-fed males was blunted after mating with HFD-fed males, with 27% fewer CD4+ T cells, 26% fewer FOXP3+CD4+ regulatory T cells (Treg) cells, and 19% fewer CTLA4+ Treg cells, particularly within the NRP1+ thymic Treg cell population. These findings demonstrate that an obesogenic HFD alters the composition of seminal vesicle fluid and impairs seminal plasma capacity to elicit a favorable pro-tolerogenic immune response in females at conception.

Pro-inflammatory cytokines and microRNAs in male infertility

Background

Male infertility is a problem that affects 10–15% of men of reproductive age. In particular, gametogenesis is a complex process in which inflammation may play a central role through the secretion of cytokines and the expression of microRNAs. We assessed the potential role of proinflammatory cytokines (TNF-α, IL-6 and IL-1α) and microRNAs (miR-146a-5p, miR-34a-5p and miR-23a-3p) in the seminal plasma of infertile men compared to controls, evaluating their correlation with seminal and biochemical parameters.

Methods and results

Expression of cytokines and microRNAs was analyzed by ELISA and q-PCR. Our data shows that IL-1α was significantly increased in the azoospermic group compared to controls, TNF-α mRNA was more expressed in the oligozoospermic group than controls. There were no significant differences in miRNAs expression among the three groups. The correlations between sperm parameters and inflammatory markers were evaluated, however no significance was highlighted.

Conclusions

The determination of each inflammatory marker separately in the seminal plasma of subfertile men, despite some significant differences, does not have a diagnostic value in male infertility even if an assay of selective pro-inflammatory cytokines and microRNAs in the semen may improve the diagnosis of male infertility.

Semen Analysis and Insight into Male Infertility

Objectives: Semen analysis is the cornerstone for the valuation of the male partner in the infertile couples. This test has been standardized throughout the world through the World Health Organization (WHO) since the1970s by producing, editing, updating, and disseminating a semen analysis manual and guidelines. A retrospective study to give an insight about  male infertility. Methods: This retrospective study assessed the semen findings of 1000 men evaluated at the  Department of Urology, Al-Kindy Teaching Hospital in Baghdad-Iraq  between January 2016 and May 2019. Semen analysis were done for them. Results: According to WHO standard for semen normality, 1000 samples that were analyzed, normospermia was shown in 835 (83.5%)males (95% CI=0.811-0.857) and 12% had oligospermia and the rest 4.5% was azospermia. The normospermic samples had significantly higher levels regarding the following parameters: count per ml (51.30±1.24) (P= 0.001), volume(3.34±2.31)(P=0.0001), pus cell (8.04±1.02)(P=0.0001), motility (22.81±5.8)(P=0.0001), abnormal motility (22.81±5.8)(P=0.0001) and  normal (V)(P=0.0001)or abnormal morphology (25.86 ±12.4)(P=0.0002) when compared with oligospermia. Conclusions: Semen analysis is the keystone of infertile couple. Semen parameters like sperm concentration, motility and morphology, are indicators for male reproductive function. Sperm concentration is declining and there is a significant association between sperm concentration and sperm parameters.

Effect of trace elements on the seminal oxidative status and correlation to sperm motility in infertile Saudi males

The impact of trace elements, especially zinc, selenium, copper, and magnesium, on male fertility has gained great interest and significance. Increased oxidative stress and altered trace element levels are probable etiological factors underlying male reproductive dysfunction and infertility. The present study focused on the evaluation of seminal oxidative markers, such as reactive oxygen species (ROS), malondialdehyde (MDA), and total antioxidant capacity (TAC), and trace element levels in the normozoospermic fertile control group (n = 40) and asthenozoospermic infertile group (n = 30). Semen from infertile men exhibited significantly higher ROS and MDA levels accompanied with significant decline in TAC and trace element (zinc and magnesium) levels. Furthermore, a significant correlation was observed between trace elements and oxidative markers with sperm motility. The current study revealed increased lipid peroxidation and oxidant-reductant imbalance that leads to deterioration of semen quality and male infertility. Thus, oxidative stress and trace elements can be considered important biomarkers of male infertility. Measurement of seminal oxidative stress with conventional seminological parameters must be integrated in fertility assessment from early stages to ensure healthy semen characteristics and fertility in men.

Seminal pro-inflammatory cytokines and pH are affected by Chlamydia infection in asymptomatic patients with teratozoospermia

Introduction

Infection and inflammation of the reproductive tract by Chlamydia trachomatis (CT) are recognized as significant risk factors for male infertility. This study aimed to evaluate CT infection and its effects on seminal parameters and cytokines in asymptomatic patients with teratozoospermia.

Material and methods

Semen samples from one hundred four male patients were collected, and CT detection was performed by polymerase chain reaction (PCR). The quality (volume, sperm concentration, pH, motility, morphology, and leucocytes) of the semen was measured by standard procedures recommended by the World Health Organization (WHO). Pro-inflammatory cytokines [interleukin (IL)-1 β, IL-6, IL-8, tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ)], as well as anti-inflammatory cytokines (IL-4, IL-10), were determined by using enzyme-linked immunosorbent assay (ELISA). The frequency of CT infection was expressed as a percentage. Descriptive statistics were used for comparison of cytokines from infertile men, and then the Mann-Whitney U test was applied for the contrast of seminal parameters and cytokines from CT-infected versus non-CT infected men.

Results

A ratio of 33/104 (31.7%) patients were positive for CT infection. The ejaculate of positive CT infection was found to have increased pH (pH = 7.65 in non-CT infected vs. 7.94 CT-infected men; p = 0.026). High levels of pro-inflammatory cytokines were found in the population studied; however, infected males were noted to have high levels of IL-1 β [184.66 (0-3985.33 pg/ml), p = 0.001] and IL-6 [87.8 (0-1042.8 pg/ml), p = 0.001].

Conclusions

CT infection increased seminal pH, as well as IL-1 β and IL-6 cytokines, suggesting a potential role of infection and inflammation in asymptomatic patients with teratozoospermia.

The "Hitchhiker's Guide to the Galaxy" of Endothelial Dysfunction Markers in Human Fertility

Endothelial dysfunction is an early event in the pathogenesis of atherosclerosis and represents the first step in the pathogenesis of cardiovascular diseases. The evaluation of endothelial health is fundamental in clinical practice and several direct and indirect markers have been suggested so far to identify any alterations in endothelial homeostasis. Alongside the known endothelial role on vascular health, several pieces of evidence have demonstrated that proper endothelial functioning plays a key role in human fertility and reproduction. Therefore, this state-of-the-art review updates the endothelial health markers discriminating between those available for clinical practice or for research purposes and their application in human fertility. Moreover, new molecules potentially helpful to clarify the link between endothelial and reproductive health are evaluated herein.

Association of Obstructive Sleep Apnea With the Risk of Male Infertility in Taiwan

IMPORTANCE

Obstructive sleep apnea (OSA) has been proposed as a risk factor in infertility. However, to date, the association between OSA and male infertility has not been examined in a population-based study.

OBJECTIVE

To investigate the risk factor of OSA in male infertility and the outcome of OSA treatment for the risk of male infertility.

DESIGN, SETTING, AND PARTICIPANTS

This case-control population-based study collected data from the Longitudinal Health Insurance Database, a subset of the National Health Insurance Research Database in Taiwan. Male patients with a diagnosis of infertility and at least 3 outpatient visits or 1 hospitalization between January 1, 2000, and December 31, 2013, were included and matched by age, sex, and date of infertility diagnosis with individuals without an infertility diagnosis. Data analysis was performed from October 22, 2018, to April 22, 2019.

EXPOSURES

Patients with male infertility and randomly selected patients without male infertility were matched using a 1:4 propensity score matching ratio.

MAIN OUTCOMES AND MEASURES

A primary outcome was the risk factor of OSA (diagnosed through polysomnography). A secondary outcome was the association of the risk of male infertility with OSA exposure time interval (short term, middle term, and long term) and OSA management (ie, none, continuous positive airway pressure, uvulopalatopharyngoplasty, or both).

RESULTS

A total of 4607 male patients with infertility (mean [SD] age, 34.18 [5.44] years) and 18 428 control patients (mean [SD] age, 34.28 [5.81] years) were included. In the multivariate conditional logistic regression analysis, OSA was an independent risk factor associated with infertility (adjusted odds ratio [OR], 1.24; 95% CI, 1.10-1.64; P = .003). The absolute risk was 0.204 (95% CI, 0.092-0.391). For patients with OSA in the group without treatment, the adjusted OR was 1.80 (95% CI, 1.56-2.07; P < .001) for infertility compared with patients without OSA.

CONCLUSIONS AND RELEVANCE

Results of this study support the hypothesis that OSA increases the risk of infertility in male patients, and the risk is associated with the OSA exposure time. Furthermore, no OSA management or treatment is associated with a higher infertility risk.

The Vehicle Determines the Destination: The Significance of Seminal Plasma Factors for Male Fertility

Of all human infertility cases, up to 50% show contributing factors leading to defects in the male reproductive physiology. Seminal plasma (SP) is the biological fluid derived from the male accessory sex gland which carries spermatozoa passing throughout the male and female reproductive tract during ejaculation. It contains a complicated set of heterogeneous molecular structures, including proteins, cell-free nucleic acid (DNA, microRNA and LncRNA), and small-molecule metabolites as well as inorganic chemicals (ions). For a long time, the substantial significance of seminal plasma factors’ functions has been underestimated, which is restricted to spermatozoa transport and protection. Notably, significant advancements have been made in dissecting seminal plasma components, revealing new insights into multiple aspects of sperm function, as well as fertilization and pregnancy outcomes in recent years. In this review, we summarize the state-of-art discoveries regarding SP compositions and their implications in male fertility, particularly describing the novel understanding of seminal plasma components and related modifications using “omics” approaches and mainly focusing on proteome and RNA-seq data in the latest decade. Meanwhile, we highlighted the proposed mechanism of the regulation of SP molecules on immunomodulation in the female reproductive tract. Moreover, we also discussed the proteins investigated as non-invasive diagnosis biomarkers for male infertility in the clinic.

Oxidative Stress is Associated with Reduced Sperm Motility in Normal Semen

Infertility is among the most serious medical problems worldwide. Male factors contribute to 40%-50% of all infertility cases, and approximately 7% of men worldwide are affected by infertility. Spermatozoa are extremely vulnerable to oxidative insult. Oxidative stress results in axonemal damage and increased midpiece sperm morphological defects, which lead to reduced sperm motility. The aim of the study is to evaluate the association between sperm motility and the levels of selected antioxidants, cytokines, and markers of oxidative damage in the seminal plasma.The study group included 107 healthy males, who were split into two subgroups based on the percentage of motile spermatozoa after 1 hr: low motility (LM, n = 51) and high motility (HM, n = 56).The glucose-6-phosphate dehydrogenase (G6PD) activity was 52% lower in the LM group compared to that in the HM group. The level of malondialdehyde (MDA) was 12% higher in the LM group compared to that in the HM group. Similarly, the median values of interleukin (IL)-1β, IL-10, IL-12, and tumor necrosis factor alpha (TNF-α) were higher in the LM group than those in the HM group. Results of the present study revealed that the percentage of motile spermatozoa after 1 hr correlated positively with the levels of IL-1β, IL-10, IL-12, and TNFα.The lower motility of spermatozoa in healthy men is associated with a decreased activity of G6PD and increased levels of cytokines, which may be related to increased oxidative stress in seminal plasma that manifests as an increased level of MDA.

Proteomic analysis of seminal plasma from bilateral varicocele patients indicates an oxidative state and increased inflammatory response

Seminal plasma is a rich source of proteins and serves as an ideal sample for proteomic analysis of male infertility. In varicocele-associated infertility, the contributory role of seminal plasma proteins specific to unilateral and bilateral varicocele is not clear. Furthermore, there is a lack of specific protein biomarker to differentiate bilateral from unilateral varicocele. The main objective is to identify the differentially regulated molecular and cellular pathways in bilateral varicocele. Furthermore, we intend to identify seminal plasma biomarkers to differentiate bilateral and unilateral varicocele patients in comparison with fertile healthy men. Global proteomic analysis of seminal plasma proteins has identified the functionality of differentially expressed proteins (DEPs) in varicocele patients. Bioinformatic analysis has revealed response to reactive oxygen species and oxidative stress, and tissue homeostasis as top process pathways that are affected in bilateral varicocele patients compared to fertile healthy men. In comparison with unilateral varicocele patients, inflammatory response pathways were dysregulated, especially interleukin 6 (IL-6) signaling and Janus kinase-signal transducer and activator of transcription (Jak-STAT) pathways, in bilateral varicocele patients, owing to the involvement of underexpressed DEPs. Key DEPs associated with oxidative stress (peroxiredoxin 2; PRDX2), DNA fragmentation (fatty acid synthase; FASN), and inflammatory response (fibronectin 1; FN1) validated by western blot analysis revealed differential expression of these proteins in unilateral and bilateral varicocele groups. Altered expression of DEPs and its association with key processes show that the seminal plasma homeostasis is compromised in bilateral varicocele patients. Furthermore, we propose PRDX2, FASN, and FN1 as potential noninvasive seminal plasma markers for the differentiation of unilateral and bilateral varicocele patients.

Human spermatozoa of male patients with subfertility express the interleukin-6 receptor

Male subfertility has been associated with bacterial infections and chronic inflammation. In this context, several studies investigated cytokine levels in seminal plasma, whereas interleukin-6 (IL-6) appears to be crucial. However, little is known about its receptor, the IL-6R expression on human spermatozoa. Thus, the aim of the present study was to screen spermatozoa for IL-6R expression and to identify its localisation. Semen samples of 137 patients (median age 37.69, SD ± 7.82) with subfertility were analysed. Sperm analysis including determination of IL-6 was performed following the World Health Organization criteria. Also, flow cytometry was performed for sperm IL-6R expression. IL-6R⁺ cells were used for immunofluorescence staining to identify receptor localisation. The results showed positive staining for IL-6R in the midpiece of spermatozoa. Furthermore, a significant correlation between sperm IL-6R expression, seminal plasma IL-6 and total sperm count could be demonstrated, whereas a negative correlation was observed in sperm IL-6R expression and motility. However, no statistical significance could be observed between IL-6R expression, vitality and morphology. Moreover, incubation of spermatozoa with IL-6 led to a slight but significant decrease in motility after 24 hr. These data suggest that IL-6R expression may play a role in impaired sperm function during inflammation.

The Female Response to Seminal Fluid

Seminal fluid is often assumed to have just one function in mammalian reproduction, delivering sperm to fertilize oocytes. But seminal fluid also transmits signaling agents that interact with female reproductive tissues to facilitate conception and .pregnancy. Upon seminal fluid contact, female tissues initiate a controlled inflammatory response that affects several aspects of reproductive function to ultimately maximize the chances of a male producing healthy offspring. This effect is best characterized in mice, where the female response involves several steps. Initially, seminal fluid factors cause leukocytes to infiltrate the female reproductive tract, and to selectively target and eliminate excess sperm. Other signals stimulate ovulation, induce an altered transcriptional program in female tract tissues that modulates embryo developmental programming, and initiate immune adaptations to promote receptivity to implantation and placental development. A key result is expansion of the pool of regulatory T cells that assist implantation by suppressing inflammation, mediating tolerance to male transplantation antigens, and promoting uterine vascular adaptation and placental development. Principal signaling agents in seminal fluid include prostaglandins and transforming growth factor-β. The balance of male signals affects the nature of the female response, providing a mechanism of ‟cryptic female choiceˮ that influences female reproductive investment. Male-female seminal fluid signaling is evident in all mammalian species investigated including human, and effects of seminal fluid in invertebrates indicate evolutionarily conserved mechanisms. Understanding the female response to seminal fluid will shed new light on infertility and pregnancy disorders and is critical to defining how events at conception influence offspring health.

The association of seminal leucocytes, interleukin-6 and interleukin-8 with sperm DNA fragmentation: A prospective study

The effect of seminal leucocytes on sperm DNA integrity has been discussed controversially in literatures. Moreover, the studies investigating the in vivo effect of pro-inflammatory cytokines interleukin-6 and interleukin-8 on sperm DNA fragmentation are scarce and inconsistent. The association of standard sperm parameters with sperm DNA fragmentation is also a matter of ongoing discussion. Hence, the aims of this study were, first, to evaluate the effect of seminal leucocytes, interleukin-6 and interleukin-8 on sperm DNA integrity and, second, to examine whether standard semen parameters are associated with sperm DNA fragmentation. Seminal leucocytes, interleukin-6, interleukin-8 and standard semen parameters, including total sperm number, sperm concentration, progressive motility, nonprogressive motility, immotility and normal morphology, were determined in 134 consecutive men. The concentrations of seminal leucocytes, interleukin-6 and interleukin-8, did not correlate with sperm DNA fragmentation. In contrast, total sperm number, sperm concentration, progressive motility, nonprogressive motility and normal morphology exhibited significant inverse correlations with sperm DNA fragmentation. Immotile spermatozoa were directly correlated with sperm DNA fragmentation. In conclusion, seminal leucocytes, interleukin-6 and interleukin-8, are not associated with sperm DNA fragmentation. Poor standard semen parameters are significantly related to the high levels of sperm DNA fragmentation.

Effects of physical exercises on semen quality and reproductive outcomes in male infertility: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Infertility has troubled the world's 186 million people, and male infertility accounts for more than half. The literature of physical exercise related to semen quality has shown inconsistent results, and there is currently no systematic review to evaluate the effects of exercise on reproductive outcomes in male infertility patients. This study aims to assessing the effects of exercise interventions based on randomized controlled trials (RCTs) on semen quality and reproductive outcomes in male infertility.

METHODS

English and Chinese literature about physical exercise treatment for male infertility published before July 31, 2019 will be systematic searched in PubMed, Embase, Web of Science, Cochrane Library, Open Grey, Clinicaltrials.gov, Chinese Clinical Trial Registry, WANFANG, VIP Chinese Science and Technology Journal Database, CNKI, Chinese biomedical document service system (SinoMed). Only RCTs of patients with male infertility will be included. Literature screening, data extraction, and the assessment of risk of bias will be independently conducted by 2 reviewers, and the 3rd reviewer will be consulted if any different opinions existed. Live-birth rate, pregnancy rate, adverse events (including miscarriage), sperm concentration, progressive motility, sperm morphology, and sperm DNA fragmentation will be evaluated. Systematic review and meta-analysis will be produced by RevMan 5.3 and Stata 14.0. This protocol reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) statement, and we will report the systematic review by following the PRISMA statement.

CONCLUSION AND DISSEMINATION

We will assess the efficacy and safety of physical exercise on semen quality and reproductive outcomes in infertile men. The findings will be published in a peer-reviewed journal to provide evidence-based medical evidence for clinical decision making and the patient's lifestyle guidance.

REGISTRATION INFORMATION

PROSPERO CRD42019140294.

The Potential Role of Seminal Plasma in the Fertilization Outcomes

For human infertility both male and female factors may be equally important. Searching for molecular biomarkers of male infertility, neglected for decades, and the attempts to explain regulatory mechanisms of fertilization become thus extremely important. Apart from examination of the structure and function of male gametes, also the possible importance of seminal plasma components should be considered. In this article we discuss data that indicate for the substantial significance of active seminal plasma components for conception and achievement of healthy pregnancy. Seminal plasma impact on the storage and cryopreservation of human and animal sperm and regulatory role of glycodelin on human sperm capacitation as well as hypothesized course of female immune response to allogenic sperm and conceptus has been discussed. The possible involvement of carbohydrates in molecular mechanism of fetoembryonic defense has been also mentioned.

Can Seminal IL-8 Level Be Used as a Marker of Leukocytospermia and Does It Have Any Correlation with Semen Parameters in Infertile Couples?

Objectives

Infection of male genital tract leads to leukocytospermia which may have a detrimental effect on semen quality. This study was conducted to evaluate whether seminal IL-8 level can be used as a marker of leukocytospermia and does it have any correlation with semen parameters in infertile couples?

Methods

This cross-sectional study was conducted in an infertility clinic of a tertiary care hospital including 150 male partners of infertile couples who underwent semen analysis (WHO laboratory manual for the examination and processing of human semen, 5th edn, World Health Organization, Geneva, p 271, 2010), semen culture sensitivity and seminal IL-8 levels. Independent t-test, Mann-Whitney U test and Chi-square test were applied for analysis.

Results

Mean seminal plasma IL-8 level of patients with leukocytospermia was significantly higher than patients without leukocytospermia (1143.67 ± 887.03 vs. 267.174 ± 242.29, p value < 0.001). Strong positive correlation was found between seminal plasma IL-8 levels and pus cells in the semen (r = 0.950, p < 0.001); AUC for seminal plasma IL-8 was 0.985 (CI 0.972-0.988), and a cutoff value of 399 pg/ml was determined to diagnose leukocytospermia. This value had high sensitivity (91.8%), specificity (94.5%), positive predictive value (94.4%) and diagnostic accuracy (93.2%) for detecting leukocytospermia. Seminal IL-8 levels correlated negatively with sperm motility (r = - 0.29, p < 0.001) and morphology (r = - 0.230, p < 0.01).

Conclusion

Seminal plasma IL-8 levels were found to be almost five times higher in male partners with leukocytospermia than in non-leukocytospermia group, and it appears to be a promising tool to detect leukocytospermia. Seminal IL-8 level correlated negatively with semen parameters including sperm motility and morphology.

The Role of Oxidative Stress, Selected Metals, and Parameters of the Immune System in Male Fertility

The aim of the study was to investigate the associations between standard semen parameters and the parameters reflecting oxidative stress intensity, antioxidant defense functions, levels of selected macro and trace elements, and parameters characterizing immune system function. The study group consisted of 103 fertile males. Based on semen volume, sperm concentration, total sperm count, and percentage of motile sperm at 1 hour postcollection, the individuals were divided into two equal groups—those with excellent (EX) semen quality and those with mediocre (ME) semen quality. The remaining measured parameters characterizing motility and the percentage of normal morphology were higher in the EX group than in the ME group; however, the seminal plasma pH did not differ between the examined groups. The phosphate level was 31% lower in the EX group than in the ME group, whereas there was a tendency toward a 25% lower level of Fe in the EX group than in the ME group (p = 0.064). The activities of enzymes involved in antioxidant defense, CuZn-SOD, CAT, and G6PD, were 14%, 63%, and 39%, respectively, higher in the EX group than in the ME group. However, the level of alpha-tocopherol was 32% lower in the EX group than in the ME group. The other measured parameters characterizing antioxidant defense and the parameters of oxidative stress intensity and immune system function were not significantly different. The value of seminal plasma pH is not related to the semen quality of fertile males. Higher fertility potential estimated based on standard semen parameters in fertile males is associated with lower levels of Fe and higher activities of some antioxidant enzymes.

Linking sleep disturbance to idiopathic male infertility

Recently published data suggests that male fertility has declined over the past four decades. The reasons for the decline are unclear with up to 50% of cases of male infertility remaining unexplained (idiopathic male infertility). Whilst environmental factors and rising rates of obesity have been implicated, there is now growing evidence that sleep disturbance may be an independent causative factor. Indeed, the prevalence of sleep disturbance appears to be increasing in parallel with deterioration in population sperm quality, a commonly used surrogate marker of male fertility. Although there is some understanding of the relationship between sleep, gonadal hormone secretion and sexual function, it remains to be seen whether sleep disturbance is implicated in idiopathic male infertility. This review will detail the current evidence supporting a link between sleep disturbance and male infertility. Potential mechanistic pathways will be proposed and evidence supporting these pathways will be discussed. Further research is needed in clarifying links between sleep disturbance and idiopathic male infertility. At present the only available treatment option for men with idiopathic infertility is assisted reproductive technology. Demonstration of a causative link between sleep disturbance and idiopathic male infertility may in the future lead to additional treatment options in selected cases.

Seminal plasma pro-inflammatory cytokines interferon-γ (IFNG) and C-X-C motif chemokine ligand 8 (CXCL8) fluctuate over time within men

STUDY QUESTION

Do seminal plasma pro-inflammatory cytokines interferon-γ (IFNG) and C-X-C motif chemokine ligand 8 (CXCL8) vary within individual men over time?

SUMMARY ANSWER

IFNG exhibits substantial variation that is independent of duration of abstinence but correlates with lipopolysaccharide (LPS) content, while CXCL8 varies moderately in association with duration of abstinence.

WHAT IS KNOWN ALREADY

Pro-inflammatory cytokines IFNG and CXCL8 in seminal fluid can adversely impact male and female fertility. Other cytokines as well as sperm parameters fluctuate considerably within individuals over time, but whether IFNG and CXCL8 vary similarly, and the determinants of variance, are unknown.

STUDY DESIGN, SIZE, DURATION

Between two and seven semen samples were collected from 14 proven fertile donors at 6-10 week intervals over the course of ~12 months, to assess variation over time in cytokines and LPS, and to investigate relationships with sperm parameters and possible regulatory factors.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The concentrations and total amounts per ejaculate of IFNG and CXCL8 were determined using commercial ELISA. Sperm parameters were assessed according to World Health Organization (WHO) IV standards and LPS was measured by limulus amebocyte lysate (LAL) assay. Mixed model analysis was utilized to determine the relative contribution of between- and within-individual factors in explaining variance. Relationships between cytokines, LPS and sperm parameters, as well as effect of age and duration of abstinence, were investigated by correlation analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Within-individual variability contributed to total variance particularly for both IFNG, CXCL8 and LPS, and was a stronger determinant than between-individual variability for IFNG and LPS. Normal sperm motility correlated inversely with CXCL8, and sperm concentration correlated inversely with LPS. Duration of abstinence was a determinant of total CXCL8, but not IFNG or LPS. Associations between LPS, IFNG and CXCL8 suggest IFNG and perhaps CXCL8 are influenced by microbial populations.

LIMITATIONS, REASONS FOR CAUTION

A limited number of donors from a single clinic were investigated. Clinical information on complete microbiology, BMI, nutrition, smoking and other lifestyle factors was unavailable. Further studies are required to determine whether the findings can be generalized to larger populations and different ethnicities.

WIDER IMPLICATIONS OF THE FINDINGS

These data reveal substantial variation over time in pro-inflammatory seminal fluid cytokines and imply existence of microbial or other environmental regulatory factors.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the National Health and Medical Research Council of Australia. The authors have no competing interests to disclose.

The enigmatic seminal plasma: a proteomics insight from ejaculation to fertilization

BACKGROUND

The 'omics' approach for a noninvasive diagnosis of male reproductive system disorders has gained momentum during the last decade, particularly from a screening and prognosis point of view. Due to the rapid development in assisted reproductive technologies (ART) over the years, the major focus of proteomic studies has been around the ejaculated spermatozoa. Although seminal plasma is not a requirement for ART, the question arose whether the role of seminal plasma is merely to transport spermatozoa.

MAIN BODY

Seminal plasma (SP) contains a large diversity of proteins that are essential not only for sperm transport, but also for sperm protection and maturation. Most of the proteins bind to sperm surface through exosomes (epididymosomes and prostasomes), modulating sperm function, interaction with the female reproductive tract and finally fertilization. This review focuses on the state-of-art discoveries regarding SP proteome and its role in fertilization.

CONCLUSION

Tissue-specific proteins in the SP have emerged as fundamental contributors for protein biomarker discovery. This is important for a noninvasive diagnosis of male infertility and development of new therapeutic approaches. Moreover, ART success rates may be improved by taking into account the critical role of seminal proteome in fertilization.

Obesity or Overweight, a Chronic Inflammatory Status in Male Reproductive System, Leads to Mice and Human Subfertility

Obesity is frequently accompanied with chronic inflammation over the whole body and is always associated with symptoms that include those arising from metabolic and vascular alterations. On the other hand, the chronic inflammatory status in the male genital tract may directly impair spermatogenesis and is even associated with male subfertility. However, it is still unclear if the chronic inflammation induced by obesity damages spermatogenesis in the male genital tract. To address this question, we used a high fat diet (HFD) induced obese mouse model and recruited obese patients from the clinic. We detected increased levels of tumor necrosis factor (TNF-α), interleukin-6 (IL-6), and NOD-like receptor family pyrin domain containing-3 (NLRP3) in genital tract tissues including testis, epididymis, seminal vesicle, prostate, and serum from obese mice. Meanwhile, the levels of immunoglobulin G (IgG) and corticosterone were significantly higher than those in the control group in serum. Moreover, signal factors regulated by TNF-α, i.e., p38, nuclear factor-κB (NF-κB), Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and their phosphorylated status, and inflammasome protein NLRP3 were expressed at higher levels in the testis. For overweight and obese male patients, the increased levels of TNF-α and IL-6 were also observed in their seminal plasma. Furthermore, there was a positive correlation between the TNF-α and IL-6 levels and BMI whereas they were inversely correlated with the sperm concentration and motility. In conclusion, impairment of male fertility may stem from a chronic inflammatory status in the male genital tract of obese individuals.

Tumor Necrosis Factor Alpha -308 G/A Single Nucleotide Polymorphism and Risk of Sperm Abnormalities in Iranian Males

BACKGROUND

Signaling molecules such as cytokines regulate spermatogenesis during the maturation of germ cells and sperm apoptosis. Tumor necrosis factor alpha (TNFα) is one of the most-documented cytokines that is involved in spermatogenesis. We investigated the association of the TNFα -308 G/A single nucleotide polymorphism with sperm abnormalities in Iranian males.

MATERIALS AND METHODS

This case-control study included 180 infertile men who re- ferred to Yazd Research and Clinical Center for Infertility and 100 healthy normospermic controls. Infertile men were classified into four groups of azoospermia (n=91), oligospermia (n=26), teratospermia (n=30) and asthenoteratospermia (n=33). After sperm analysis, DNA was extracted from blood and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was carried out for the genotyping of TNFα- 308 G/A.

RESULTS

The A allele was significantly associated with sperm abnormality in our population [(P<0.001, odds ratios (OR) 95% confidence interval (CI)=2.31]. In addition, the A allele was also associated with azoospermia (P<0.001, OR (95% CI)=2.484), oligospermia (P=0.005, OR (95% CI)=2.51) and teratospemia (P<0.001, OR (95% CI)=3.385) but not with asthenoteratospermia (P=0.623).

CONCLUSION

Our data suggest that this single nucleotide polymorphism (SNP) maybe associated with the risk of sperm abnormality in infertile men of Iranian origin.

Is male factor infertility associated with midlife low-grade inflammation? A population based study

Male factor infertility is associated with an increased risk of disease and mortality, which has been related to markers of chronic systemic inflammation. The objective of this study was to investigate the association between male factor infertility and low-grade inflammation and furthermore to examine the lifetime prevalence of male factor infertility and overall infertility (also including female and couple infertility). The study population consisted of 2140 members of the Metropolit 1953 Danish Male Birth Cohort who had participated in the Copenhagen Aging and Midlife Biobank data collection in 2009-2011. Information on male factor infertility and overall infertility was obtained from a questionnaire, and low-grade inflammation was evaluated as the highest plasma levels of C-reactive protein, interleukin-6 and tumour necrosis factor-alpha in the population. The level of interleukin-6 was significantly higher among men with male factor infertility compared with other men adjusted for potential confounders. This was not found for the two other inflammatory markers. The lifetime prevalence of male factor infertility and overall infertility were 10.2% and 17.9%, respectively. The findings suggest that male factor infertility might be associated with an increased level of interleukin-6.

Seminal plasma transforming growth factor-β, activin A and follistatin fluctuate within men over time

STUDY QUESTION

Do seminal plasma transforming growth factor-β (TGFB) cytokines vary within individuals over time, and does this relate to sperm parameters, age or prior abstinence?

SUMMARY ANSWER

Activin A and follistatin, and to a lesser extent TGFB1, TGFB2 and TGFB3, vary within individuals over time, in association with duration of abstinence.

WHAT IS ALREADY KNOWN

Seminal plasma TGFB cytokines can influence sperm function and reproductive success through interactions with the female reproductive tract after coitus. Over time, individual sperm parameters fluctuate considerably. Whether seminal fluid TGFB cytokines vary similarly, and the determinants of any variance, is unknown.

STUDY DESIGN, SIZE, DURATION

Between two and seven semen samples were collected from each of 14 fertile donors at 6-10 week intervals over the course of 12 months, then seminal plasma cytokines and sperm parameters were measured.

PARTICIPANTS/MATERIALS, SETTING AND METHOD

The concentrations and total amounts per ejaculate of TGFB1, TGFB2, TGFB3, activin A and follistatin were determined using commercial assays. Sperm parameters were assessed according to WHO IV standards. Mixed model analysis was utilised to determine the relative contribution of between- and within-individual factors to the variance. Relationships between cytokines and sperm parameters, as well as effect of age and duration of abstinence, were investigated by correlation analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Within-individual variability contributed to the total variance for all cytokines and sperm parameters, and was a stronger determinant than between-individual variability for activin A and follistatin as well as for total sperm concentration and sperm motility. Positive correlations between each of the three TGFB isoforms, and activin and follistatin, suggest co-regulation of synthesis. Duration of abstinence influenced total content of TGFB1, TGFB2, activin A and follistatin. TGFB1 correlated inversely with age.

LIMITATIONS, REASONS FOR CAUTION

A limited number of donors from a single clinic were investigated. Clinical information on BMI, nutrition, smoking and other lifestyle factors was unavailable. Further studies are required to determine whether the findings can be generalised to larger populations and different ethnicities.

WIDER IMPLICATIONS OF THE FINDINGS

These data reveal substantial variation over time in seminal fluid cytokines and indicate that repeated analyses are required to gain precise representative data on an individual's status. Within-individual variation in seminal fluid components should be taken into account when investigating seminal fluid cytokines.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by grants from the National Health and Medical Research Council of Australia, ID453556 and APP1041332. The authors have no competing interests to disclose.

Seminal fluid and fertility in women

Seminal fluid is often viewed as simply a vehicle to carry sperm to fertilize the oocyte, but a more complex function in influencing female reproductive physiology is now evident. Remarkably, seminal fluid contains soluble and exosome-born signaling agents that interact with the female reproductive tract to prime the immune response, with consequences for fertility and pregnancy outcome. Experiments in rodent models demonstrate a key role for seminal fluid in enabling robust embryo implantation and optimal placental development. In particular, seminal fluid promotes leukocyte recruitment and generation of regulatory T cells, which facilitate embryo implantation by suppressing inflammation, assisting uterine vascular adaptation, and sustaining tolerance of fetal antigens. There is emerging evidence of comparable effects in women, where seminal fluid provokes an adaptive immune response in the cervical tissues after contact at intercourse, and spermatozoa accessing the higher tract potentially affect the endometrium directly. These biological responses may have clinical significance, explaining why [1] intercourse in IVF ET cycles improves the likelihood of pregnancy, [2] inflammatory disorders of gestation are more common in women who conceive after limited exposure to seminal fluid of the prospective father, and [3] preeclampsia incidence is elevated after use of donor oocytes or donor sperm where prior contact with conceptus alloantigens has not occurred. It will be important to define the mechanisms through which seminal fluid interacts with female reproductive tissues, to provide knowledge that may assist in preconception planning and infertility treatment.

Seminal fluid factors regulate activin A and follistatin synthesis in female cervical epithelial cells

Seminal fluid induces pro-inflammatory cytokines and elicits an inflammation-like response in the cervix. Here, Affymetrix microarray and qPCR was utilised to identify activin A (INHBA) and its inhibitor follistatin (FST) amongst the cytokines induced by seminal plasma in Ect1 ectocervical epithelial cells, and a similar response was confirmed in primary ectocervical epithelial cells. TGFB is abundant in seminal plasma and all three TGFB isoforms induced INHBA in Ect1 and primary cells, and neutralisation of TGFB in seminal plasma suppressed the INHBA response. Bacterial lipopolysaccharide in seminal plasma also elicited INHBA, but potently suppressed FST production. There was moderate reciprocal inhibition between FST and INHBA, and cross-attenuating effects were seen. These data identify TGFB and potentially LPS as factors mediating seminal plasma-induced INHBA synthesis in cervical cells. INHBA and FST induced by seminal fluid in cervical tissues may thus contribute to regulation of the post-coital response in women.

The Seminal Plasma of the Boar is Rich in Cytokines, with Significant Individual and Intra-Ejaculate Variation

PROBLEM

The boar, as human, sequentially ejaculates sperm-rich and sperm-poor fractions. Seminal plasma (SP) spermadhesins (PSP-I/PSP-II) induce a primary endometrial inflammatory response in female sows, similar to that elicited by semen deposition in other species, including human. However, the SP is also known to mitigate such response, making it transient to allow for embryo entry to a cleansed endometrium. Although cytokine involvement has been claimed, the exploration of cytokines in different SP fractions is scarce. This study determines Th1, Th2, Th17 and Th3 cytokine profiles in specific ejaculate SP fractions from boars of proven fertility.

METHODS

SP samples from the sperm-rich fraction (SRF) and the sperm-poor post-SRF fraction (post-SRF) of manually collected ejaculates from eight boars (four ejaculates per boar) were analysed by commercial multiplex bead assay kits (Milliplex MAP, Millipore, USA) for interferon-γ, interferon gamma-induced protein 10, macrophage-derived chemokine, growth-regulated oncogene, granulocyte-macrophage colony-stimulating factor, monocyte chemo-attractant protein-1, interleukins (IL)-6, IL-8, IL-10, IL-15, IL-17 and transforming growth factor (TGF)-β1-β3.

RESULTS

Cytokine concentrations differed between the ejaculate fractions among boars, being highest in the post-SRF.

CONCLUSION

Boar SP is rich in Th1, Th2, Th17 and Th3 cytokines, with lowest concentrations in the sperm-peak-containing fraction, indicating its main immune influence might reside in the larger, protein-rich sperm-poor post-SRF.

The influence of macro and trace elements on sperm quality

The aim of this study was to examine the association between combined concentrations of macro and trace elements and markers of oxidative stress and antioxidative defense system function together with selected cytokine levels. Based on the combined medians of the seminal plasma levels of calcium, magnesium, zinc, copper, iron, and selenium, the study subjects (88 fertile male volunteers) were divided into the following two subgroups: the Me-L group (low level of metals) and the Me-H group (high level of metals). There was a tendency toward reduced motility in the Me-H group compared to that in the Me-L group. The total protein, albumin, and total oxidation status (TOS) levels were significantly higher in the Me-H group than in the Me-L group. The total superoxide dismutase (SOD), Mn-SOD, and CuZn-SOD, activity in spermatozoa were significantly lower in the Me-H group than in the Me-L group. In seminal plasma, the Mn-SOD activity was significantly higher in the Me-H group, whereas the CuZn-SOD activity was significantly lower. Additionally, the activity levels of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were lower in the Me-H group. The medians of IL-1β, IL-10, and IL-12 were significantly higher in the Me-H group than in the Me-L group, whereas the medians of IL-2, IL-5, and IL-13 were significantly lower. Higher levels of macro and trace elements in the seminal plasma of fertile males may be associated with decreased motility. Higher levels of the examined metals are associated with elevated oxidative stress accompanied by decreased activities of some of the antioxidant enzymes and increased pro-inflammatory cytokine levels.

Infectious, inflammatory, and immunologic conditions resulting in male infertility

This article provides an overview of infectious and inflammatory conditions associated with male infertility. These conditions may affect several components of the male reproductive tract and therefore have the ability to potentially alter sperm function. The effect of these conditions on male fertility is poorly understood and often underestimated.