Identification of seminal markers of male accessory gland inflammation: From molecules to proteome

Male Tract Microbiota and Male Infertility

In recent years, several studies have analyzed the composition of the male genital tract microbiota and its changes in infertility or in different situations associated with infertility. The aim of this narrative review is to obtain more insight on this topic; in particular, to describe actual evidence about changes in the semen microbiota in patients with infertility, male tract infections, or HPV infections. In semen, an increase in semen Prevotella spp. is associated with oligozoospermia and with obesity-associated asthenozoospermia; an increase in Pseudomonas is more frequently associated with asthenozoospermia and oligozoospermia; a reduction in Lactobacilli spp. (namely in Lactobacillus crispatus) may represent a marker of low semen quality. However, an increase in Lactobacillus iners is considered a risk factor for a reduced sperm concentration. In patients with prostatitis, there is a reduction in Lactobacillus spp. and an increase in Streptococcus spp., opening important perspectives about the role of probiotic treatments in these patients. Finally, an increase in Fusobacteria spp. was observed in patients with an HPV infection. In the conclusion, we underline the interactions between the seminal and vaginal microbiota, so that further studies should focus on the "couple genital microbiota".

Chronic Prostatitis/Chronic Pain Pelvic Syndrome and Male Infertility

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is defined as urologic pain or discomfort in the pelvic region, associated with urinary symptoms and/or sexual dysfunction, lasting for at least 3 of the previous 6 months. The rate of symptoms related to prostatitis has a mean prevalence of 8-8.2%. CP/CPPS is most frequent in men younger than 50 years, among whom it is the most common urologic diagnosis. In the last decades, many studies have been published on CP/CPPS and its association with male infertility. The pathophysiologic relation between CP/CPPS and male infertility involves several aspects, which are not well studied yet. A reduction in semen parameters has been demonstrated in patients with CP/CPPS, and several mechanisms have been proposed to represent putative pathophysiological links between CP/CPPS and infertility, including male accessory gland inflammation, metabolic syndrome, inflammatory bowel disease, HPV co-infection and autoimmunity. In light of this evidence, a multidisciplinary approach is advocated for patients with known CP/CPPS, and particular attention is needed for male patients of infertile couples in order to evaluate male accessory glands correctly. In addition, it is advisable that future studies dealing with the treatment of CP/CPPS take into consideration all the different pathophysiological aspects implicated.

Male accessory gland inflammation (MAGI): an evolving entity

Male accessory gland infection (MAGI) is a generic acronym indicating inflammatory conditions affecting the prostate gland, seminal vesicles, the ductus deferens and the epididymis. It is a frequent disease, mostly with a chronic course. Majority of the MAGIs remain asymptomatic, thereby leading to a debate whether to treat these patients or not. The primary criterion for MAGI was suggested by Comhaire and colleagues in 1980. The role of MAGI in causing infertility and sexual dysfunctions has long been a matter of debate. The most recent studies show that MAGI could alter, with various mechanisms, both conventional and biofunctional sperm parameters, and determine worst reproductive outcome. This article provides an overview of up-to-date research findings about MAGI with special focus on data published on its impact on fertility; and diagnostic criteria including cellular and seminal biomarkers along with the promising results of emerging proteomic platforms for the identification of MAGI.

Relevance of Leukocytospermia and Semen Culture and Its True Place in Diagnosing and Treating Male Infertility

The current WHO 2010 manual for human semen analysis defines leukocytospermia as the presence of peroxidase-positive leukocytes at a concentration >1×106/mL of semen. Granular leukocytes when activated are capable of generating high levels of reactive oxygen species in semen resulting in oxidative stress. Oxidative stress has been correlated with poor sperm quality, increased level of sperm DNA fragmentation and low fertility potential. The presence of leukocytes and pathogens in the semen may be a sign of infection and/or localized inflammatory response in the male genital tract and the accessory glands. Common uro-pathogens including Chlamydia trachomatis, Ureaplasma urealyticum, Neisseria gonorrhoeae, Mycoplasma hominis, and Escherichia coli can cause epididymitis, epididymo-orchitis, or prostatitis. The relationship between leukocytospermia and infection is unclear. Therefore, we describe the pathogens responsible for male genital tract infections and their association with leukocytospermia. The review also examines the diagnostic tests available to identify seminal leukocytes. The role of leukocytospermia in male infertility and its management is also discussed.

Interferon γ, IL-17, and IL-1β impair sperm motility and viability and induce sperm apoptosis

Urogenital inflammation is a known cause of male infertility. Increased levels of inflammatory cytokines, leukocyte counts and oxidative stress are highly detrimental for sperm quality thus compromising male fertility. Although cytokines affect sperm by recruiting and activating leukocytes consequently inducing tissue inflammation and oxidative stress, scarce to absent data have been reported about the putative direct effects of inflammatory cytokines on spermatozoa. Herein, we analyzed whether IFNγ, IL-17A, IL-1β, and IL-8 can alter human sperm motility and viability per se. Fractions of viable and motile spermatozoa from normospermic healthy donors were in vitro incubated with recombinant human IFNγ, IL-17A, IL-1β or IL-8 and sperm ROS production, motility, viability and apoptosis were analyzed. Sperm exposed to different concentrations of IFNγ, IL-17A and IL-1β, or a combination of them, for either 1 or 3 h showed significantly increased levels of mitochondrial ROS production and reduced motility and viability with respect to sperm incubated with vehicle. Moreover, the exposure to IFNγ, IL-17A and IL-1β resulted in significantly higher levels of early and/or late apoptotic and/or necrotic spermatozoa. Interestingly, no significant differences in sperm motility, viability and apoptosis were observed in sperm incubated with the concentrations of IL-8 analyzed, for either 1 or 3 h, with respect to sperm incubated with vehicle. In conclusion, our results indicate that IFNγ, IL-17A and IL-1β per se impair sperm motility and decreases viability by triggering increased mitochondrial ROS production and inducing sperm apoptosis. Our results suggest that screening inflammatory cytokines in semen would be an additional helpful tool for the diagnostic workup of male infertility.

Fatty Acid Oxidation and Pro-Resolving Lipid Mediators Are Related to Male Infertility

Specialized pro-resolving lipid mediators regulate the resolution of acute inflammation. They are formed by enzymatic oxygenation of polyunsaturated fatty acids and are divided into families including lipoxins, resolvins, protectins, and maresins. Resolvin D1 (RvD1), produced by docosahexaenoic acid, exerts anti-inflammatory and pro-resolving activities. This research aimed to investigate the implication of seminal RvD1 in human infertility. Infertile patients (n° 67) were grouped based on pathological reproductive conditions as idiopathic infertility, varicocele, and leukocytospermia; the fourth group was composed of fertile men (n° 18). Sperm characteristics were evaluated by light microscopy (WHO guidelines) and by transmission electron microscopy (TEM). The seminal levels of RvD1 and F2-isoprostane (F2-IsoPs) were dosed. In twenty men (6 fertile men, 8 with varicocele, 6 with leukocytospermia) seminal phospholipase A2, iron, cholesterol, transferrin, estradiol, ferritin, testosterone, and sperm membrane fatty acids were detected. The results indicated that: (i) RvD1 amount was positively correlated with F2-IsoPs and reduced sperm quality; (ii) RvD1 levels were significantly higher in patients with leukocytospermia, varicocele, and idiopathic infertility compared to fertile men; (iii) RvD1 increased along with other markers of oxidative stress and inflammation as fatty acids content and clinical biomarkers. This study suggests a panel of inflammatory markers and lipid mediators for a diagnosis of inflammatory status and a subsequent appropriate therapeutic approach.

Male reproductive system inflammation after healing from coronavirus disease 2019

BACKGROUND

There is evidence that, after severe acute respiratory syndrome coronavirus 2 infection, male reproductive function and semen quality may be damaged OBJECTIVES: To evaluate a panel of inflammatory mediators in semen in patients recovered from coronavirus disease 2019.

MATERIAL AND METHODS

Sexually active men with previous severe acute respiratory syndrome coronavirus 2 infection and proven recovery from coronavirus disease 2019 were enrolled in a prospective cohort study. Clinical, uro-andrological data and semen specimens were prospectively collected. For previously hospitalized coronavirus disease 2019 patients, data on serum inflammatory markers were retrospectively collected.

RESULTS

A total of 43 men were enrolled in the study. Of these, 32 men were normozoospermic, three were oligozoospermic, and eight were crypto-azoospermic. Serum inflammatory markers (procalcitonin and C-reactive protein) were analyzed in previously hospitalized patients both at admission and at peak of infection. Levels at admission were statistically significantly higher in patients resulting in crypto-azoospermic with respect to those resulting in normozoospermic (p = 0.05; p = 0.03 and p = 0.02, respectively) after healing. Seminal cytokine levels were similar among all groups. Interleukin-1β and tumor necrosis factor-α levels were significantly negatively related to sperm total number and concentration, whereas interleukin-4 was correlated with sperm motility.

DISCUSSION AND CONCLUSION

Negative correlations between interleukin-1β and tumor necrosis factor-α and sperm number and the overall high levels of semen cytokines indicate a potential detrimental role of severe acute respiratory syndrome coronavirus 2 driven inflammation on spermatogenesis. Overall, our results indicate that male patients recovering from coronavirus disease 2019 deserve accurate follow-up for their fertility status.

Semen parameters in men recovered from COVID-19: a systematic review and meta-analysis

BACKGROUND

The novel beta-coronavirus disease (COVID-19) has infected millions of people globally with high risk among males than females. However, the effect of COVID-19 andrology is still a subject of dispute. We planned to analyze the overall consequences of COVID-19 on semen parameters and male sex hormones.

MAIN TEXT

Systematic search was performed on MEDLINE and Scopus database until 11 June 2021. We included observational studies, which reported mean ± standard deviation of the semen parameters and serum sex hormones of those reproductive-aged males recovered from COVID-19 and controls who did not suffered from COVID-19. We used Random-effect model to pool the studies, as heterogeneity was present. The Q test and I 2 evaluated heterogeneity. All articles were assessed with their quality and publication bias.We assessed 966 articles for eligibility and found seven eligible studies. These 7 studies included 934 participants with mean age 37.34 ± 10.5 years. Random-effect model meta-analysis showed that men who recovered from COVID-19 had semen parameters less than those who had not suffered from COVID-19. The overall mean difference (MD) [95% confidence interval (CI)] in semen volume, sperm concentration, sperm number, and progressive sperm motility was - 0.20 (- 0.45, 0.05) ml, - 16.59 (- 34.82, 1.65) millions/ml, - 45.44 (- 84.56, - 6.31) millions per ejaculate, - 1.73 (- 8.20, 4.75) percentage respectively. Considering sex hormones, luteinizing hormone and prolactin levels were higher among those recovered with a significant MD (95% CI) of 3.47 (1.59, 5.35)U l-1 and 3.21 (1.71, 4.72)ng ml-1 respectively.

CONCLUSION

We found that COVID-19 affects both semen parameters and sexual hormones. However, the mechanism for testicular involvement remains doubtful.

TRIAL REGISTRATION

PROSPERO CRD42021259445.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s43043-021-00089-w.

The secret identities of TMPRSS2: Fertility factor, virus trafficker, inflammation moderator, prostate protector and tumor suppressor

The human TMPRSS2 gene is pathogenetically implicated in both coronaviral lung infection and prostate cancer, suggesting its potential as a drug target in both contexts. SARS-COV-2 spike polypeptides are primed by the host transmembrane TMPRSS2 protease, triggering virus fusion with epithelial cell membranes followed by an endocytotic internalisation process that bypasses normal endosomal activation of cathepsin-mediated innate immunity; viral co-opting of TMPRSS2 thus favors microbial survivability by attenuating host inflammatory responses. In contrast, most early hormone-dependent prostate cancers express TMPRSS2:ERG fusion genes arising from deletions that eliminate the TMPRSS2 coding region while juxtaposing its androgen-inducible promoter and the open reading frame of ERG, upregulating pro-inflammatory ERG while functionally disabling TMPRSS2. Moreover, inflammatory oxidative DNA damage selects for TMPRSS2:ERG-fused cancers, whereas patients treated with antiinflammatory drugs develop fewer of these fusion-dependent tumors. These findings imply that TMPRSS2 protects the prostate by enabling endosomal bypass of pathogens which could otherwise trigger inflammation-induced DNA damage that predisposes to TMPRSS2:ERG fusions. Hence, the high oncogenic selectability of TMPRSS2:ERG fusions may reflect a unique pro-inflammatory synergy between androgenic ERG gain-of-function and fusogenic TMPRSS2 loss-of-function, cautioning against the use of TMPRSS2-inhibitory drugs to prevent or treat early prostate cancer.

Semen impairment and occurrence of SARS-CoV-2 virus in semen after recovery from COVID-19

STUDY QUESTION

How is the semen quality of sexually active men following recovery from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection?

SUMMARY ANSWER

Twenty-five percent of the men with recent SARS-Cov-2 infections and proven healing were oligo-crypto-azoospermic, despite the absence of virus RNA in semen.

WHAT IS KNOWN ALREADY

The presence of SARS-CoV-2 in human semen and its role in virus contagion and semen quality after recovery from coronavirus disease 2019 (COVID-19) is still unclear. So far, studies evaluating semen quality and the occurrence of SARS-CoV-2 in semen of infected or proven recovered men are scarce and included a limited number of participants.

STUDY DESIGN, SIZE, DURATION

A prospective cross-sectional study on 43 sexually active men who were known to have recovered from SARS-CoV2 was performed. Four biological fluid samples, namely saliva, pre-ejaculation urine, semen, and post-ejaculation urine, were tested for the SARS-CoV-2 genome. Female partners were retested if any specimen was found to be SARS-CoV-2 positive. Routine semen analysis and quantification of semen leukocytes and interleukin-8 (IL-8) levels were performed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Questionnaires including International Index of Erectile Function and Male Sexual Health Questionnaire Short Form were administered to all subjects. The occurrence of virus RNA was evaluated in all the biological fluids collected by RT-PCR. Semen parameters were evaluated according to the World Health Organization manual edition V. Semen IL-8 levels were evaluated by a two-step ELISA method.

MAIN RESULTS AND THE ROLE OF CHANCE

After recovery from COVID-19, 25% of the men studied were oligo-crypto-azoospermic. Of the 11 men with semen impairment, 8 were azoospermic and 3 were oligospermic. A total of 33 patients (76.7%) showed pathological levels of IL-8 in semen. Oligo-crypto-azoospermia was significantly related to COVID-19 severity (P < 0.001). Three patients (7%) tested positive for at least one sample (one saliva; one pre-ejaculation urine; one semen and one post-ejaculation urine), so the next day new nasopharyngeal swabs were collected. The results from these three patients and their partners were all negative for SARS-CoV-2.

LIMITATIONS, REASONS FOR CAUTION

Although crypto-azoospermia was found in a high percentage of men who had recovered from COVID-19, clearly exceeding the percentage found in the general population, the previous semen quality of these men was unknown nor is it known whether a recovery of testicular function was occurring. The low number of enrolled patients may limit the statistical power of study.

WIDER IMPLICATIONS OF THE FINDINGS

SARS-CoV-2 can be detected in saliva, urine, and semen in a small percentage of men who recovered from COVID-19. One-quarter of men who recovered from COVID-19 demonstrated oligo-crypto-azoospermia indicating that an assessment of semen quality should be recommended for men of reproductive age who are affected by COVID-19.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Microbiological Evaluation and Sperm DNA Fragmentation in Semen Samples of Patients Undergoing Fertility Investigation

Fifteen percent of male infertility is associated with urogenital infections; several pathogens are able to alter the testicular and accessory glands' microenvironment, resulting in the impairment of biofunctional sperm parameters. The purpose of this study was to assess the influence of urogenital infections on the quality of 53 human semen samples through standard analysis, microbiological evaluation, and molecular characterization of sperm DNA damage. The results showed a significant correlation between infected status and semen volume, sperm concentration, and motility. Moreover, a high risk of fragmented sperm DNA was demonstrated in the altered semen samples. Urogenital infections are often asymptomatic and thus an in-depth evaluation of the seminal sample can allow for both the diagnosis and therapy of infections while providing more indicators for male infertility management.

Ultrasound evaluation of patients with male accessory gland inflammation: a pictorial review

Male accessory gland infection/inflammation (MAGI) is a major cause of male infertility. The importance of ultrasound evaluation in these patients is highly controversial, although evidence of its relevance has increased in recent years. Ultrasound criteria are an important element for confirming the clinical diagnosis. Furthermore, they help to localize the anatomical site or sites of the inflammatory process and in assessing its extension which, in turn, have different consequences on the seminological and symptomatic aspects. This article summarizes the clinical interpretations related to ultrasound aspects in patients with MAGI and the possible effects on the seminological, microbiological, endocrinologic, urological, sexological, and internist aspects.

Relationship Between Semen IL-6, IL-33 and Malondialdehyde Generation in Human Seminal Plasma and Spermatozoa

Cytokines are physiological seminal components and their abnormal levels, reported in different pathological conditions, negatively influence the sperm function. We analysed the relationship between interleukin (IL)-6 and IL-33 levels and lipid peroxidation (LPO), measured both in semen and sperm lysate, in 44 human semen samples. The semen analysis was performed following the WHO guidelines. Seminal IL-6 and IL-33 concentrations were assessed by ELISA and LPO was evaluated measuring malondialdehyde (MDA) both in seminal plasma and viable spermatozoa. Two small groups of patients with varicocele and infection were extrapolated from the cases analysed and the variables compared with those of a group of control. IL-33 levels were undetectable in all samples and IL-6 levels were positively correlated with both seminal and sperm MDA concentrations (p < 0.01) and negatively with sperm parameters (p < 0.01). Seminal and sperm MDA levels were both negatively correlated with sperm parameters (p < 0.01). IL-6 and semen MDA showed an exponential positive relationship, whereas MDA values measured in viable spermatozoa were low until IL-6 amount reached a concentration of >30 pg/mL, rising consistently. By comparing the variables in the groups, we confirmed that a high IL-6 concentration in the varicocele and infection groups was concomitant with an increase of seminal MDA levels, but also with MDA measured in viable spermatozoa, which represents the novelty of this study. We identified the IL-6 threshold, beyond which sperm MDA concentration rises concomitantly with the increase of IL-6 concentration. Other studies are needed, considering the increasing number of patients with different pathologies affecting male infertility.

Measurable Cytokine Concentrations in Pig Seminal Plasma Are Modified by Semen Handling and Storage

Sample handling and storing are critical steps for the reliable measurement of circulating biomolecules in biological fluids. This study evaluates how cytokine measurements in pig seminal plasma (SP) vary depending on semen handling and SP storage. Thirteen cytokines (GM-CSF, IFNγ, IL-1α, IL-1β, IL-1ra, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18 and TNFα) were measured using Luminex xMAP^® technology in individual seminal plasma (SP) samples (n = 62) from healthy breeding boars. Three separate experiments explored the delay (2 h and 24 h) in SP collection after ejaculation (Experiment 1) and SP storage, either short-term (5 °C, −20 °C and −80 °C for 72 h, Experiment 2) or long-term (at −20 °C and −80 °C for two months, Experiment 3), before analysis. Levels in fresh SP-samples were used as baseline control values. Delays in SP harvesting of up to 24 h did not substantially impact SP cytokine measurements. Some cytokines showed instability in stored SP samples, mainly in long-term storage. Ideally, cytokines in pig SP should be measured in fresh samples harvested within 24 h after ejaculation. If storage of SP is imperative, storage conditions should be adjusted for each cytokine.

The role of infections and leukocytes in male infertility

Declining birth rates are one of the problems facing society today. Male counterparts are responsible for about half of the infertility cases, and genitourinary tract infections may play a contributing role in approximately 15% of male infertility cases. Leukocytospermia is an established indicator of infection in the male urogenital tract, although other microorganisms such as bacteria and virus may also be contributors to the etiology of male infertility. The pathophysiology of these infectious agents may be initiated by a local inflammatory reaction resulting in an increase in reactive oxygen species (ROS). This results in testicular injury, thereby affecting sperm morphology, sperm motility, sperm viability and elevation of the seminal leukocyte as a result of the genital tract infection. The infectious and inflammatory changes can result in male infertility. It is proposed that high concentrations of seminal leukocyte and infectious agents may affect sperm function resulting in clumping of motile spermatozoa, decreasing acrosomal functionality and also causing alterations in sperm morphology. However, the literature has poorly clarified the role of infection in male infertility, provoking further debate and research on this topic.

Period of Boar Ejaculate Collection Contributes to the Yearly Intra-Male Variability of Seminal Plasma Cytokines

The concentrations of cytokines in seminal plasma (SP) fluctuate over time in healthy males, weakening their practical usefulness as diagnostic tools. This study evaluated the relevance of intra-male variability in SP cytokines and to what extent the period of the year when ejaculate is collected contributes to such variability. Thirteen cytokines (GM-CSF, IFNγ, IL-1α, IL-1β, IL-1ra, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, and TNFα) were measured using the Luminex xMAP^® technology for 180 SP samples of ejaculate collected over a year from nine healthy and fertile boars. The SP samples were grouped into two annual periods according to decreasing or increasing daylight and ambient temperature. Intra-male variability was higher than inter-male variability for all cytokines. All SP cytokines showed concentration differences between the two periods of the year, showing the highest concentration during the increasing daylength/temperature period, irrespective of the male. Similarly, some cytokines showed differences between daylength/temperature periods when focusing on their total amount in the ejaculate. No strong relationship (explaining more than 50% of the total variance) was found between annual fluctuations in SP-cytokine levels and semen parameters. In conclusion, the period of the year during which ejaculates were collected helps explain the intra-male variability of SP-cytokine levels in breeding boars.

Differential seminal plasma proteome signatures of acute lymphoblastic leukemia survivors

With advances in therapeutic methods, there is a high survival rate among leukemia patients, of an extent more than 80%. However, chemotherapeutic drugs used to treat these patients have adverse effects on their overall health profile including fertility. The primary aim of this study was to identify differentially expressed proteins in seminal plasma of acute lymphoblastic leukemia (ALL) survivors compared to age-matched healthy controls, which can provide molecular basis of idiopathic infertility in such survivors. Differential proteome profiling was performed by 2D-differential in-gel electrophoresis, protein spots were identified by mass spectrometry and selective differentially expressed proteins (DEPs) were validated by western blotting and ELISA method. Out of eight DEPs identified, five proteins (isocitrate dehydrogenase 1, semenogelin 1, lactoferrin, prolactin-inducible protein, and human serum albumin) were upregulated and three (pepsinogen, prostate specific antigen and prostatic acid phosphatase) were downregulated. Expression profiles of these proteins are suggestive of reduction in semen quality in ALL survivors and can further be explored to determine their fertility status.