Summary
The concept that an elevation of testicular temperature results in impairment of spermatogenesis is widely accepted. Here, current knowledge concerning genital heat stress and its ...consequences in men is reviewed. Duration of sitting during work positively correlates with daytime scrotal temperatures and daytime scrotal temperature negatively correlates with semen quality. However, the assumed negative correlation between duration of sitting and semen quality could not be shown in the available studies. Fertility parameters of professional drivers with long periods of sitting in vehicles were impaired; however, for predominantly affected drivers of vans, trucks or industrial heavy machinery potential confounders have to be considered. Wearing tight fitting compared with loose‐fitting underwear is associated with significantly higher scrotal temperatures. However, available observations suggesting a link between tight‐fitting underwear or trousers and impaired semen quality are not convincing. Studies addressing professional exposure to high temperatures delivered conflicting results concerning fertility parameters. The postulated negative impact of sauna visits on semen quality is not sufficiently underlined by the available studies. Oligozoospermic men with a varicocele have significantly higher scrotal temperatures than normozoospermic men, and according to several studies varicocelectomy normalises scrotal temperatures. A further link has been reported between fever and deteriorated semen quality. Contraception via genital heat stress has been demonstrated using hot sitting baths or insulating suspensors. However, down‐regulation of spermatogenesis is inconsistent and unsafe. On the other hand, scrotal and consecutively testicular cooling is able to improve semen quality.
Summary
Existing literature suggests evidence that protamine deficiency is related to DNA damage and male fertility. In this meta‐analysis, we analyzed the relationship between the ratio of ...protamine‐1 and protamine‐2 with male fertility and the association of protamine deficiency with sperm DNA damage. Quality of available cohort studies was evaluated using the Newcastle–Ottawa Scale checklist. Summary effect estimates with 95% confidence intervals (CI) were derived using a random effects model. The effect of the protamine ratio on male fertility was analyzed in nine studies demonstrating a significantly higher value of the protamine ratio in subfertile men (n = 633) when compared with controls (n = 453, SMD = 0.46, 95% CI 0.25–0.66, Z = 4.42, p < 0.00001). Both protamine mRNA (SMD = 0.45, 95% CI 0.11–0.79, Z = 2.63, p = 0.009) and protein ratio (SMD = 0.46, 95% CI 0.25–0.68, Z = 4.22, p < 0.0001) showed significantly increased values in subfertile patients. The association between protamine deficiency and DNA damage was analyzed in 12 studies (n = 845) exhibiting a combined overall correlation coefficient (COR) of 0.53 (95% CI 0.28–0.71, Z = 3.87, p < 0.001). Protamine deficiency measured by CMA3 staining was significantly associated with sperm DNA damage (COR = 0.71, 95% CI 0.48–0.85, Z = 4.87, p < 0.001), whereas the P1/P2 ratio was not (COR = 0.17, 95% CI −0.16 to 0.46, Z = 0.99, p = 0.33). It is concluded that the protamine ratio represents a suitable biomarker for the assessment of sperm quality and protamine deficiency is closely related with sperm DNA damage.
Summary
Infection and inflammation of the male reproductive tract are accepted as important aetiological factors of infertility. With regard to their impact on male reproductive function, orchitis ...and epididymo‐orchitis due to local or systemic infection as well as noninfectious aetiological factors are of particular concern. There is clinical and pathological evidence that chronic inflammatory conditions of the testes can disrupt spermatogenesis and irreversibly alter both sperm number and quality. In the majority of patients, however, diagnosis is hampered by an asymptomatic course of the disease and unspecific clinical signs. Hence, respective epidemiological data are scarce. On the other hand, systematic histopathological work‐up of testicular biopsies from infertile men indicates a high prevalence of inflammatory reactions. A characteristic pattern of inflammatory lesions with focal or multifocal, predominantly peritubular lymphocyte infiltration and concomitant damage of seminiferous tubules is seen in chronic orchitis of various origins. This supports the concept that induction of testicular inflammation is associated with a T‐cell‐mediated autoimmune response, i.e. disruption of the immune privilege. Moreover, despite the patchy distribution of the lesions, testicular volume and score counts for spermatogenesis may be significantly reduced. In conclusion, asymptomatic inflammatory reactions in the testis should not be neglected as an underlying cause or co‐factor of male infertility. However, definitive diagnosis of chronic asymptomatic orchitis still requires testicular biopsy and guidelines for the therapeutic management are not yet available.
Summary
Chronic inflammatory conditions of the genital tract are frequently encountered in male fertility problems. The diagnosis, however, is hampered by a mostly asymptomatic course of the disease ...as well as inappropriate definitions and unspecific diagnostic criteria. With regard to their impact on male reproductive function, epididymitis seems to be more relevant than inflammation/infection of the prostate and/or seminal vesicles. Chronic epididymitis may result in reduced sperm count and motility. Impaired sperm motility because of epididymal dysfunction is frequently associated with an atypical staining behaviour of sperm tails. In many cases of chronic epididymitis, the number of leukocytes in the ejaculate is below the threshold of 106 per ml; therefore, consideration of additional markers of inflammation such as granulocyte elastase, pro‐inflammatory cytokines (e.g. interleukin‐6 or 8) or reactive oxygen species is helpful for establishing the diagnosis. Besides changes in the conventional sperm parameters, alterations in DNA integrity have been observed. Positive effects of antiphlogistic/antibiotic treatment on semen quality have been reported; however, controlled prospective studies are still lacking.
The interaction of sperm with the oocyte is pivotal during the process of mammalian fertilization. The limited numbers of sperm that reach the fallopian tube as well as anatomic restrictions indicate ...that human sperm–oocyte encounter is not a matter of chance but a directed process. Chemotaxis is the proposed mechanism for re-orientating sperm toward the source of a chemoattractant and hence to the oocyte. Chemokines represent a superfamily of small (8–11 kDa), cytokine-like proteins that have been shown to mediate chemotaxis and tissue-specific homing of leukocytes through binding to specific chemokine receptors such as CCRs. Here we show that CCR6 is abundantly expressed on human sperms and in human testes. Furthermore, radioligand-binding experiments showed that CCL20 bound human sperm in a specific manner. Conversely, granulosa cells of the oocyte-surrounding cumulus complex as well as human oocytes represent an abundant source of the CCR6-specific ligand CCL20. In human ovaries, CCL20 shows a cycle-dependent expression pattern with peak expression in the preovulatory phase and CCL20 protein induces chemotactic responses of human sperm. Neutralization of CCL20 in ovarian follicular fluid significantly impairs sperm migratory responses. Conversely, analyses in infertile men with inflammatory conditions of the reproductive organs demonstrate a significant increase of CCL20/CCR6 expression in testis and ejaculate. Taken together, findings of the present study suggest that CCR6-CCL20 interaction may represent an important factor in directing sperm–oocyte interaction. Graphical Abstract Summary Sentence The chemokine CCL20 is produced by human oocytes as well as surrounding cumulus granulosa cells and induces chemotaxis of CCR6+ sperm. Infertile male donors demonstrate increased levels of CCL20 in testis and seminal fluid, which may negatively influence sperm–oocyte interaction.
Abstract Objectives To perform a comprehensive follow-up analysis of ultrasonographic scrotal features and associated signs in patients with acute epididymitis. Methods Between 2007 and 2012, 134 ...adults (median age 54 years) with acute epididymitis underwent scrotal ultrasonography and palpation at first presentation and after 2 weeks and 3 months. Results At first presentation, 61 patients (45.5%) had hydrocele, 63 (47.0%) concomitant orchitis, and 8 (5.9%) epididymal abscess. Epididymitis was predominantly located in 24 cases (17.9%) in the head, 52 cases (38.8%) in the tail, and 58 cases (43.3%) in both. On the affected side, testicular volume was 16.9 ± 6.8 ml and peak systolic velocity of the testicular artery was 23.7 ± 7.5 cm/s, compared to the healthy side with 12.3 ± 4.4 ml and 9.5 ± 3.6 cm/s respectively ( P < 0.001). Concomitant orchitis was associated with hydrocele, testicular enlargement and pain ( P < 0.01). Orchiectomy due to secondary testicular infarction was necessary in four cases, while in all other patients ultrasound parameters normalized. Only 16/90 patients (17.8%) showed a persistent epididymal swelling after 3 months. Conclusions Common ultrasound features include hydrocele, epididymal enlargement, hyperperfusion, and testicular involvement. Under conservative treatment, ultrasound parameters normalize without evidence of testicular atrophy even in patients with epididymal abscess or concomitant orchitis.
Background
Urogenital infections and inflammation are a significant etiologic factor in male infertility.
Methods
Data for this review were acquired by a systematic search of the medical literature. ...Relevant cross-references were also taken into account.
Results
We address infectious and inflammatory diseases of different compartments of the male genital tract and discuss their andrological sequelae. Chronic urethritis might be responsible for silent genital tract inflammation with negative impact on semen quality. In chronic pelvic pain syndrome, morphological abnormalities of spermatozoa and seminal plasma alterations are detectable. In the majority of men with epididymitis, a transient impairment of semen quality can be found during the acute infection. However, persistent detrimental effects are not uncommon, even after complete bacteriological cure. The relevance of chronic viral infections as an etiologic factor in male infertility is believed to be underestimated. Data concerning the impact of HIV infection on male fertility are of increasing interest as with the improvement in life expectancy, issues of sexuality and procreation gain importance. Moreover, effects of noninfectious systemic inflammation on the male reproductive tract have to be considered in patients with metabolic syndrome, a disorder of growing relevance worldwide. Finally, microbiological and related diagnostic findings in urine and semen samples are reviewed according to their relevance for male infertility.
Conclusions
Available data provide sufficient evidence that in men with alterations of the ejaculate, urogenital infections and inflammation have to be considered.
Background
Human testicular germ cell tumours (TGCT) arise from germ cell neoplasia in situ (GCNIS) cells that originate from foetal germ cell precursors. Activin A is central to normal foetal testis ...development, and its dysregulation may contribute to TGCT aetiology.
Objective
(i) To test whether the expression profiles of activin A targets in normal and neoplastic human testes indicates functional links with TGCT progression. (ii) To investigate whether activin A levels influence MMP activity in a neoplastic germ cell line.
Materials and Methods
(1) Bouin's fixed, paraffin‐embedded human testes were utilized for PCR‐based transcript analysis and immunohistochemistry. Samples (n = 5 per group) contained the following: (i) normal spermatogenesis, (ii) GCNIS or (iii) seminoma. CXCL12, CCL17, MMP2 and MMP9 were investigated. (2) The human seminoma‐derived TCam‐2 cell line was exposed to activin A (24 h), and target transcripts were measured by qRT‐PCR (n = 4). ELISA (n = 4) and gelatin zymography (n = 3) showed changes in protein level and enzyme activity, respectively.
Results
(i) Cytoplasmic CXCL12 was detected in Sertoli and other somatic cells, including those surrounding seminoma cells. Anti‐CCL17 labelled only the cytoplasm of Sertoli cells surrounding GCNIS, while anti‐MMP2 and anti‐MMP9 labelled germline and epithelial‐like cells in normal and neoplastic testes. (ii) Exposing TCam‐2 cells to activin A (50 ng/mL) elevated MMP2 and MMP9 transcripts (fourfold and 30‐fold), while only MMP2 protein levels were significantly higher after activin A (5 ng/mL and 50 ng/mL) exposure. Importantly, gelatin zymography revealed activin A increased production of activated MMP2.
Discussion
Detection of CCL17 only in GCNIS tumours may reflect a change in Sertoli cell phenotype to a less mature state. Stimulation of MMP2 activity by activin A in TCam‐2 cells suggests activin influences TGCT by modulating the tumour niche.
Conclusion
This knowledge provides a basis for understanding how physiological changes that influence activin/TGF‐β superfamily signalling may alter germ cell fate.
•Adult testicular leukocytes characterized via flow cytometry and confocal microscopy.•Mononuclear phagocyte and lymphocyte heterogeneity documented.•New testicular leukocytes sub-populations ...identified.•Impact of activin A activity on testicular macrophage phenotype indicated.
Detailed morphological characterization of testicular leukocytes in the adult CX3CR1 gfp/+ transgenic mouse identified two distinct CX3CR1 + mononuclear phagocyte (macrophage and dendritic cell) populations: stellate/dendriform cells opposed to the seminiferous tubules (peritubular), and polygonal cells associated with Leydig cells (interstitial). Using confocal microscopy combined with stereological enumeration of CX3CR1gfp/+ cells established that there were twice as many interstitial cells (68%) as peritubular cells (32%). Flow cytometric analyses of interstitial cells from mechanically-dissociated testes identified multiple mononuclear phagocyte subsets based on surface marker expression (CX3CR1, F4/80, CD11c). These cells comprised 80% of total intratesticular leukocytes, as identified by CD45 expression. The remaining leukocytes were CD3+ (T lymphocytes) and NK1.1+ (natural killer cells). Functional phenotype assessment using CD206 (an anti-inflammatory/M2 marker) and MHC class II (an activation marker) identified a potentially tolerogenic CD206+MHCII+ sub-population (12% of total CD45+ cells). Rare testicular subsets of CX3CR1 +CD11c+F4/80+ (4.3%) mononuclear phagocytes and CD3+NK1.1+ (3.1%) lymphocytes were also identified for the first time. In order to examine the potential for the immunoregulatory cytokine, activin A to modulate testicular immune cell populations, testes from adult mice with reduced activin A (Inhba+/−) or elevated activin A (Inha+/−) were assessed using flow cytometry. Although the proportion of F4/80+CD11b+ leukocytes (macrophages) was not affected, the frequency of CD206+MHCII+cells was significantly lower and CD206+MHCII− correspondingly higher in Inha+/− testes. This shift in expression of MHCII in CD206+ macrophages indicates that changes in circulating and/or local activin A influence resident macrophage activation and phenotype and, therefore, the immunological environment of the testis.
Summary
Given the increasing prevalence of metabolic syndrome (MetS) in males of reproductive age, the objective of this prospective case–controlled study was to investigate the impact of subacute ...systemic inflammation associated with MetS on seminal cytokines and standard sperm parameters in comparison with healthy men. Between 2011 and 2014, we recruited 27 patients with MetS out of 41 obese patients screened from an internal outpatient clinic. Twenty‐seven age‐matched healthy controls were enrolled from 54 men requesting vasectomy in a urological outpatient clinic. A multiplex analysis was performed to quantify simultaneously the level of 30 cytokines (Eotaxin, FGF, Fraktalkine, GCSF, GMCSF, Granzyme A, IFN‐γ, IL‐1α, IL‐1β, IL‐2, IL‐4, IL‐5, IL‐6, IL‐7, IL‐8, IL‐9, IL‐10, IL‐12p70, IL‐13, IL‐17A, IL‐21, IP‐10, I‐TAC, MCP‐1, MIG, MIP‐1α, MIP‐1β, RANTES, TNF‐α, and VEGF) in each 50 μL of blood and seminal plasma during the andrological work‐up. Semen analysis was performed according to the WHO (Global status report on noncommunicable diseases, 2010) recommendations, including standard sperm parameters as well as peroxidase‐positive leukocytes and polymorphonuclear elastase. Blood levels of C‐reactive protein, interleukins 6 and 10 were elevated in MetS (p > 0.001). Two‐way hierarchical cluster analysis showed characteristic cytokine networks in semen greatly differing from those in blood, but not between MetS and controls. No deterioration of semen analysis was evident in men diagnosed with MetS. Our results suggest that there is no transmission of the systemic inflammation associated with MetS into semen based on cytokine profiles and that MetS does not impair standard semen parameters to a clinically significant extent.
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