The blood-epididymis barrier and inflammation

Protective Effects of Resveratrol Against Perfluorooctanoic Acid-Induced Testicular and Epididymal Toxicity in Adult Rats Exposed During Their Prepubertal Period

The antioxidant properties of resveratrol (RES) against oxidative toxicity induced by testicular toxicants are well documented. The current study aimed to investigate the probable beneficial role of RES on male reproduction in adult rats following prepubertal exposure to perfluorooctanoic acid (PFOA). Healthy rats of the Wistar strain (23 days old) were allocated into four groups. Rats in group I did not receive any treatment, while rats in groups II, III, and IV received RES, PFOA, and RES + PFOA, respectively, between days 23 and 56 and were monitored for up to 90 days. Exposure to PFOA resulted in a significant reduction in spermiogram parameters, testicular 3β- and 17β-HSD activity levels, and circulatory levels of testosterone. A significant elevation in LPx, PCs, H2O2, and O2-, associated with a concomitant reduction in SOD, CAT, GPx, GR, and GSH, was noticed in the testes, as well as region-specific changes in pro- and antioxidants in the epididymides of exposed rats compared to controls. A significant increase in serum FSH and LH, testicular cholesterol levels, and caspase-3 activity was observed in PFOA-exposed rats compared to controls. Histological analysis revealed that the integrity of the testes was deteriorated in PFOA-exposed rats. Transcriptomic profiling of the testes and epididymides revealed 98 and 611 altered genes, respectively. In the testes, apoptosis and glutathione pathways were disrupted, while in the epididymides, glutathione and bile secretion pathways were altered in PFOA-exposed rats. PFOA exposure resulted in the down-regulation in the testes of 17β-HSD, StAR, nfe2l2, ar, Lhcgr, and mRNA levels, associated with the up-regulation of casp3 mRNA, and down-regulation of alpha 1 adrenoceptor, muscarinic choline receptor 3, and androgen receptor in the epididymides of exposed rats compared to the controls. These events might lead to male infertility in PFOA-exposed rats. In contrast, restoration of selected reproductive variables was observed in RES plus PFOA-exposed rats compared to rats exposed to PFOA alone. Taken together, we postulate that prepubertal exposure to PFOA triggered oxidative damage and altered genes in the testes and epididymides, leading to suppressed male reproductive health in adult rats, while RES, with its steroidogenic, antiapoptotic, and antioxidant effects, restored PFOA-induced fertility potential in rats.

Regulation of NHE3 subcellular localization in epididymal principal cells: pH, cyclic adenosine 3,5 monophosphate (cAMP), and adenosine signaling

INTRODUCTION

The epididymis creates an optimal acidic luminal environment for sperm maturation and storage. In epididymal principal cells (PCs), proton secretion is activated by the accumulation of the sodium-proton exchanger type 3, NHE3 (SLC9A3), in apical stereocilia. PCs also secrete ATP, which is hydrolyzed into adenosine by ectonucleotidases. Adenosine has opposite effects depending on which purinergic receptors it activates. Activation of ADORA1 (A1) and ADORA3 (A3) receptors decreases intracellular cAMP (cAMP), while activation of ADORA2A (A2A) and ADORA2B (A2B) receptors increases cAMP. In other epithelia, cAMP triggers NHE3 internalization from the apical membrane. Here, we examined the roles of pH, cAMP, and adenosine (via A3, A2A, and A2B receptors) in the subcellular localization of NHE3 in PCs.

METHODS

3D immunofluorescence confocal microscopy was used to visualize NHE3 in stereocilia or intracellular vesicles. Single confocal microscopy images superimposed with bright-field imaging was used to quantify NHE3 subcellular localization. The lumen of the cauda (Cd) epididymis of C57Bl/6Ncrl mice was perfused in vivo at pH 6.0 and 7.8. The effect of a permeant analog of cAMP (cpt-cAMP) was studied at pH 7.8, while the effect of adenosine was investigated at pH 6.0. Expression of A2A, A2B, and A3 was examined by immunofluorescence, and their respective role was evaluated by using specific agonists and antagonists at different luminal pH. Immunofluorescence for clathrin, an endosomal marker, was examined at pH 7.8 with and without an A2B agonist.

RESULTS

At an acidic pH perfusion solution of 6.0, NHE3 was predominantly localized intracellularly, whereas an alkaline pH of 7.8 promoted its accumulation in apical stereocilia. Perfusion with cpt-cAMP at pH 7.8 reduced the amount of NHE3 in stereocilia. Immunolabeling showed the localization of A3, A2A, and A2B receptors in the apical membrane of epithelial cells in the Cd epididymis. Adenosine and an A3 agonist increased NHE3 stereocilia accumulation at pH 6.0, and the adenosine effect was abolished with an A3 antagonist. An A2A agonist had no effect on NHE3 localization, while an A2B agonist decreased the amount of NHE3 in stereocilia observed at pH 7.8. A concomitant increase in intracellular labeling for clathrin was induced by the A2B agonist at pH 7.8.

CONCLUSIONS

Our study indicates that in the Cd epididymis, NHE3 localization in PCs is modulated by luminal pH, cAMP, and adenosine receptor signaling. Acidic pH promotes NHE3 internalization, while alkaline pH facilitates its accumulation in stereocilia. Activation of A3 by luminal adenosine maintains NHE3 on the cell surface. Conversely, A2B activation by adenosine induces NHE3 internalization. We propose that the distinct effects mediated by these receptors are the consequence of their opposite effect on cAMP signaling. This intricate interplay of pH and adenosine highlights some of the regulatory mechanisms influencing the establishment of an optimal acidic environment for sperm maturation and storage in the epididymis.

Physiological and pathological aspects of epididymal sperm maturation

In mammals, sperm that leave the testes are nonfunctional and require a complex post-testicular maturation process to acquire their ability to recognize and fertilize the egg. The crucial maturation changes that provide sperm their fertilizing capability occur while passing through the epididymis. Due to the widespread use of assisted reproductive technologies to address male infertility, there has been a significant decrease in research focusing on the mechanisms underlying the maturation process over the past decades. Considering that up to 40% of male infertility is idiopathic and could be reflecting sperm maturation defects, the study of post-testicular sperm maturation will clearly contribute to a better understanding of the causes of male infertility and to the development of both new approaches to maturing sperm in vitro and safer male contraceptive methods. Based on this, the present review focuses on the physiopathology of the epididymis as well as on current approaches under investigation to improve research in sperm maturation and as potential therapeutic options for male infertility.

Immunoregulatory mechanisms between epithelial clear cells and mononuclear phagocytes in the epididymis

INTRODUCTION

One of the most intriguing aspects of male reproductive physiology is the ability of the epididymis to prevent the mounting of immune responses against the onslaught of foreign antigens carried by spermatozoa while initiating very efficient immune responses versus stressors. Epithelial clear cells are strategically positioned to work in a concerted manner with region-specific heterogeneous subsets of mononuclear phagocytes to survey the epididymal barrier and regulate the balance between inflammation and immune tolerance in the post-testicular environment.

OBJECTIVE

This review aims to describe how clear cells communicate with mononuclear phagocytes to contribute to the unique immune environment in which sperm mature and are stored in the epididymis.

MATERIALS/METHODS

A comprehensive systematic review was performed. PubMed was searched for articles specific to clear cells, mononuclear phagocytes, and epididymis. Articles that did not specifically address the target material were excluded.

RESULTS

In this review, we discuss the unexpected roles of clear cells, including the transfer of new proteins to spermatozoa via extracellular vesicles and nanotubes as they transit along the epididymal tubule; and we summarize the immune phenotype, morphology, and antigen capturing, processing, and presenting abilities of mononuclear phagocytes. Moreover, we present the current knowledge of immunoregulatory mechanisms by which clear cells and mononuclear phagocytes may contribute to the immune-privileged environment optimal for sperm maturation and storage.

DISCUSSION AND CONCLUSION

Notably, we provide an in-depth characterization of clear cell-mononuclear phagocyte communication networks in the steady-state epididymis and in the presence of injury. This review highlights crucial concepts of mucosal immunology and cellcell interactions, all of which are critical but understudied facets of human male reproductive health.

Exploring complex links: inflammatory rheumatic diseases and men's health

This article examines the complex interactions between inflammatory rheumatic diseases (IRDs) and men's health. It delves into the effects of IRDs on reproductive health, erectile dysfunction, prostate involvement, male osteoporosis, body composition, physical activity, and coping mechanisms. The findings show that the prevalence of sexual dysfunction varies among different diseases, underscoring the necessity for comprehensive counseling. The link between IRDs and prostate health, with a substantial rise in benign prostatic hyperplasia among IRD patients, demonstrates the condition's importance. In contrast to popular belief, osteoporosis mostly affects women; the current study highlights the growing identification of male osteoporosis, particularly in the setting of IRDs. Male RA patients had a significant loss in bone mineral density, highlighting the importance of increasing awareness and tailored therapy to address osteoporosis in men. IRDs affect body composition, with male RA patients showing imbalances characterized by decreased lean body mass and increased fat mass. Given the dynamic nature of these conditions, coping with IRDs necessitates thorough and individualized diversified approaches. The complex link between IRDs and men's health demands continuing research, including longitudinal studies and tailored therapies. The essay promotes a patient-centered approach, recognizing the unique obstacles that males with IRDs confront.

Morphology of the immune cells in the wall of the human uterine tube and their possible impact on reproduction-uterine tube as a possible immune privileged organ

The uterine tube, as well as other parts of the upper female reproductive system, is immunologically unique in its requirements for tolerance to allogenic sperm and semi-allogenic embryos, yet responds to an array of sexually transmitted pathogens. To understand this dichotomy, there is a need to understand the functional morphology of immune cells in the wall of the uterine tube. Thus, we reviewed scientific literature regarding immune cells and the human uterine tube by using the scientific databases. The human uterine tube has a diverse population of immunocompetent cells representing both the innate and adaptive immune systems. We describe in detail the possible roles of cells of the mononuclear phagocyte system (macrophages and dendritic cells), T and B lymphocytes, natural killer cells, neutrophils and mast cells in association with the reproductive functions of uterine tubes. We are also discussing about the possible "immune privilege" of the uterine tube, as another mechanism to tolerate sperm and embryo without eliciting an inflammatory immune response. In uterine tube is not present an anatomical blood-tissue barrier between antigens and circulation. However, the immune cells of the uterine tube probably represent a type of "immunological barrier," which probably includes the uterine tube among the immunologically privileged organs. Understanding how immune cells in the female reproductive tract play roles in reproduction is essential to understand not only the mechanisms of gamete transport and fertilization as well as embryo transport through the uterine tube, but also in improving results from assisted reproduction.

Silica nanoparticles induces sperm granuloma formation and blood-epididymal barrier disruption via the p38 MAPK pathway in mice

Previous researches have demonstrated that the silica nanoparticles (SiNPs), which are widely used in all aspects of life, are hazardous to the male reproductive system. However, the cellular and molecular mechanism underlying SiNPs toxicity to the epididymis remain unclear. In this present study, a total of 60 male mice were separated into 4 groups and then treated to SiNPs for 7 consecutive days at a dose of 0, 2.5, 10, and 20 mg/kg body weight. The results showed that SiNPs could alter the histological structure of epididymis and induce sperm granuloma formation, leading to decreased sperm quality and quantity. In addition, the ultrastructure and permeability of blood-epididymal barrier (BEB) were impaired after exposure to SiNPs, and a significant downregulation of integral membrane proteins at the BEB was detected. SiNPs were also found to raise the percentage of macrophages in the epithelium and interstitium of the epididymis, followed by increased expression of pro-inflammatory molecules including TNF α, IL-1β, and IL-6. Meanwhile, SiNPs induced oxidative stress in epididymis, as shown by the markedly elevated generation of reactive oxygen species (ROS) and malondialdehyde (MDA) and upregulated activity of superoxide dismutase (SOD). Further study showed that SiNPs activated the p38 MAPK signaling pathway, which accelerated clathrin-mediated endocytosis of integral membrane proteins and perturb vesicular trafficking. Taken together, exposure to SiNPs could induce sperm granuloma formation and impair the integrity of BEB in mice through activating the p38 MAPK pathway.

Rituximab alleviates increased disomic sperm in DBA/1J mouse models of rheumatoid arthritis via restoration of redox imbalance

Compared to the general population, patients with arthritis have a higher risk of fertility abnormalities, which have deleterious effects on both reproductive function and pregnancy outcomes, especially in patients wishing to conceive. These may be due to the disease itself or those of drug therapies. Despite the increasing use of rituximab in arthritis, limited data are available on its potential to induce aneuploidy in germ cells. Therefore, the aim of the current investigation was to determine if repeated treatment with rituximab affects the incidence of aneuploidy and redox imbalance in arthritic mouse sperm. Mice were treated with 250 mg/kg rituximab once weakly for 3 weeks, and then sperm were sampled 22 days after the last dose of rituximab. Fluorescence in situ hybridization assay with chromosome-specific DNA probes was used to evaluate the disomic/diploid sperm. Our results showed that rituximab had no aneuploidogenic effect on the meiotic stage of spermatogenesis. Conversely, arthritis induced a significantly high frequency of disomy, and treatment of arthritic mice with rituximab reduced the increased levels of disomic sperm. The occurrence of total diploidy was not significantly different in all groups. Reduced glutathione and8-hydroxydeoxyguanosine, markers of oxidative stress were significantly altered in arthritic animals, while rituximab treatment restored these changes. Additionally, arthritis severity was reduced after rituximab treatment. We conclude that rituximab may efficiently alleviate the arthritis-induced effects on male meiosis and avert the higher risk of abnormal reproductive outcomes. Therefore, treating arthritic patients with rituximab may efficiently inhibit the transmission of genetic anomalies induced by arthritis to future generations.

Identification and Functional Assignment of Genes Implicated in Sperm Maturation of Tibetan Sheep

While traveling through the epididymis, immature sheep spermatozoa undergo a sequence of processes that ultimately give them the capacity to swim and fertilize an egg. Different gene expression patterns may be found in the epididymal caput, corpus, and cauda, conferring variant or unique biological roles during epididymis development and sperm maturation. To search for candidate genes associated with ovine sperm maturation and assess their possible modulating mechanisms, we characterized gene expression in each epididymal segment derived from pre- and post-pubertal Tibetan sheep by RNA sequencing. Compared with pre-puberty, 7730 (3724 upregulated and 4006 downregulated), 7516 (3909 upregulated and 3607 downregulated), and 7586 (4115 elevated and 3471 downregulated) genes were found to be differentially expressed in the post-pubertal caput, corpus, and cauda epididymis, respectively, and real-time quantitative PCR verified the validity of the gathered expression patterns. Based on their functional annotations, most differential genes were assigned to the biological processes and pathways associated with cellular proliferation, differentiation, immune response, or metabolic activities. As for the post-pubertal epididymis, 2801, 197, and 186 genes were specifically expressed in the caput, corpus, and cauda, respectively. Functional annotation revealed that they were mainly enriched to various distinct biological processes associated with reproduction (including the caput binding of sperm to the zona pellucida; fertilization in the caput and corpus; and meiosis in the caput and cauda) and development (such as cell differentiation and developmental maturation in the caput; cell proliferation and metabolism in the corpus; and regulation of tube size and cell division/cell cycle in the cauda). Additionally, we focused on the identification of genes implicated in immunity and sperm maturation, and subsequent functional enrichment analysis revealed that immune-related genes mainly participated in the biological processes or pathways associated with the immune barrier (such as JAM3 and ITGA4/6/9) and immunosuppression (such as TGFB2, TGFBR1, TGFBR2, and SMAD3), thus protecting auto-immunogenic spermatozoa. Additionally, sperm maturation was mostly controlled by genes linked with cellular processes, including cell growth, proliferation, division, migration, morphogenesis, and junction. Altogether, these results suggest that most genes were differentially expressed in developmental epididymal regions to contribute to microenvironment development and sperm maturation. These findings help us better understand the epididymal biology, including sperm maturation pathways and functional differences between the epididymal regions in Tibetan sheep and other sheep breeds.

Pathology of African Swine Fever in Reproductive Organs of Mature Breeding Boars

African swine fever (ASF) is a severe, globally important disease in domestic and wild pigs. The testing of alternative transmission routes has proven that the ASF virus (ASFV) can be efficiently transmitted to sows via semen from infected boars through artificial insemination. Boars intramuscularly inoculated with the ASFV strain “Estonia 2014” showed grossly and microscopically visible changes in the testis, epididymis, prostate, and vesicular gland. The gross lesions included hemorrhages on the scrotum, testicular membranes, and parenchyma; edema; hydroceles; and proliferations of the tunica vaginalis. Histopathologically, vasculitis and perivasculitis was detected in the testis and epididymis. Subacutely infected animals further revealed a degeneration of the testicular and epididymal tubules, pointing to the destruction of the blood–testis and blood–epididymis barriers upon disease progression. This was confirmed by evidence of semen round cells and sperm abnormalities at later time points after the infection. The histopathology was associated with the presence of viral DNA and the infectious virus, and in a limited amount with viral antigens. In most scenarios, the impact of these changes on the reproductive performance and long-term persistence of the virus is probably negligible due to the culling of the animals. However, under backyard conditions and in wild boar populations, infected males will remain in the population and the long-term fate should be further evaluated.

Organoids of the male reproductive system: Challenges, opportunities, and their potential use in fertility research

Organoids are units of function of a given organ able to reproduce, in culture, a biological structure similar in architecture and function to its counterpart in vivo. Today, it is possible to develop an organoid from a fragment of tissue, a stem cell located in an adult organ, an embryonic stem cell, or an induced pluripotent stem cell. In the past decade, many organoids have been developed which mimic stomach, pancreas, liver and brain tissues, optic cups, among many others. Additionally, different male reproductive system organs have already been developed as organoids, including the prostate and testis. These 3D cultures may be of great importance for urological cancer research and have the potential to be used in fertility research for the study of spermatozoa production and maturation, germ cells-somatic cells interactions, and mechanisms of disease. They also provide an accurate preclinical pipeline for drug testing and discovery, as well as for the study of drug resistance. In this work, we revise the current knowledge on organoid technology and its use in healthcare and research, describe the male reproductive system organoids and other biomaterials already developed, and discuss their current application. Finally, we highlight the research gaps, challenges, and opportunities in the field and propose strategies to improve the use of organoids for the study of male infertility situations. This article is categorized under: Reproductive System Diseases > Stem Cells and Development Reproductive System Diseases > Biomedical Engineering.

The abundance and localization of claudin-1 and -5 in the adult tomcats (Felis catus) testis, tubules rectus, rete testis, efferent ductules, and epididymis

Tight junctions (TJ) are the anatomical component of blood-testis (BTB) and blood-epididymis (BEB) barriers and contain many proteins, including claudins. The presence of claudins in domestic cat testis and epididymis has not been previously described. This study aimed to determine whether claudin-1 and claudin-5 participate in the structure of BTB and BEB and whether their amounts differ between the testis and epididymal segments of adult cats, using Western blotting (WB) and immunohistochemistry. WB results demonstrated that claudin-1 was significantly lower in the testis than in all epididymal segments and higher in the corpus epididymis than in the cauda, while claudin-5 in the testis was significantly lower than in the caput and corpus. Claudin-1 was absent at the Sertoli-Sertoli junctions, while claudin-5 was detected at the level of the BTB during stages I and VIII. Both claudins were observed in the pachytene spermatocytes and the developing acrosome of the round and elongating spermatids. Claudin-5 was also detected in the cytoplasm of some spermatogonia, Sertoli cells, and late spermatid acrosome. In the epididymal segments, both claudins were localized to the area of the tight junctions and along the entire length of the lateral plasma membranes of adjacent principal cells and between principal and basal cells. These results may indicate that in the domestic cat, claudin-1 and -5 participate as both tight junction proteins and adhesion molecules in the BEB's structure, claudin 5 is a component of the BTB, and both proteins may be involved in postmeiotic germ cell development, especially acrosome development.

Purinergic signaling in the male reproductive tract

Purinergic receptors are ubiquitously expressed throughout the body and they participate in the autocrine and paracrine regulation of cell function during normal physiological and pathophysiological conditions. Extracellular nucleotides activate several types of plasma membrane purinergic receptors that form three distinct families: P1 receptors are activated by adenosine, P2X receptors are activated by ATP, and P2Y receptors are activated by nucleotides including ATP, ADP, UTP, UDP, and UDP-glucose. These specific pharmacological fingerprints and the distinct intracellular signaling pathways they trigger govern a large variety of cellular responses in an organ-specific manner. As such, purinergic signaling regulates several physiological cell functions, including cell proliferation, differentiation and death, smooth muscle contraction, vasodilatation, and transepithelial transport of water, solute, and protons, as well as pathological pathways such as inflammation. While purinergic signaling was first discovered more than 90 years ago, we are just starting to understand how deleterious signals mediated through purinergic receptors may be involved in male infertility. A large fraction of male infertility remains unexplained illustrating our poor understanding of male reproductive health. Purinergic signaling plays a variety of physiological and pathophysiological roles in the male reproductive system, but our knowledge in this context remains limited. This review focuses on the distribution of purinergic receptors in the testis, epididymis, and vas deferens, and their role in the establishment and maintenance of male fertility.

How does the boar epididymis regulate the emission of fertile spermatozoa?

The epididymis is responsible for peripheral immune tolerance of maturing spermatozoa even though these have xeno-antigens foreign to the male and female immune system. The epididymis also produces factors required for fertilization and serves as a sperm repository until the time of ejaculation. These reproduction-relevant epididymal functions occur in the mesonephros-derived duct-system that is composed of absorptive and secretory epithelial cells with the capacity for merocrine and apocrine secretion of proteins, antioxidative- and electrolyte/pH-regulating enzymes and small, non-coding RNAs (sncRNAs), many stored in epididymosomes for sperm adhesion and long-lasting modifications of sperm functions. This paper provides a review summary of current and new knowledge of how the boar epididymis affects the quality of spermatozoa in the ejaculate of breeding boars. There is a particular focus on sperm maturation, survival, function and the role of signaling to the female immune system in fertility modulation. Furthermore, aspects related to the ductus epithelial contributions regarding electrolyte control, protein production, release of epididymosomes that contain sncRNAs are emphasized as are novel associations with fertility of the male, sperm quiescence during storage in the cauda epididymis, and on changes occurring in sperm subsequent to ejaculation.

Emerging organoid models to study the epididymis in male reproductive toxicology

The importance of the epididymis on sperm maturation and consequently male fertility has been well documented. The pseudostratified epithelium of the epididymis is comprised of multiple cell types, including principal cells, which are the most abundant, and basal cells. The role of basal cells has been unclear and has been a source of discussion in the literature. However, the recent demonstration that these cells are multipotent or adult stem cells has opened new areas of research in epididymal biology. One such avenue is to understand the regulation of these stem cells, and to exploit their properties to develop tools for toxicological studies to elucidate the effects of chemicals on cell differentiation and epididymal function in vitro. Studies in both rat and mouse have shown that purified single epididymal basal cells cultured under 3D conditions can proliferate and differentiate to form organoids, or mini organs. Furthermore, these epididymal basal stem cells can self-renew and differentiate into other epididymal cell types. It is known that during epididymal development, basal cells are derived from undifferentiated columnar cells, which have been reported to share common properties to stem cells. Like basal cells, these undifferentiated columnar cells can also form organoids under 3D culture conditions and can differentiate into basal, principal and clear cells. Organoids derived from either basal cells or columnar cells offer unique models for toxicology studies and represent an exciting and emerging approach to understand the epididymis.

Treatment with the anti-CD20 monoclonal antibody rituximab mitigates gonadal disruptions in the collagen-induced arthritis in male DBA/1 J mouse model

Rheumatoid arthritis (RA), which is driven by persistent activation of the immune system, primarily affects the joints. Several reports have estimated the risk of gonadal disruptions in arthritic patients, with potential attributable risk factors such as treatments with the disease-modifying antirheumatic drugs and the influence of the disease itself. The FDA approved rituximab, a therapy for non-Hodgkin's lymphoma, for management of RA in February 2006. However, the influence of repeated treatment with rituximab on gonadal function in RA has not been reported yet. Thus, the aim of the presents study is to evaluate whether repeated treatment with the clinically relevant dose of rituximab may change the gonadal disruptions in collagen-induced arthritis in male DBA/1 J mouse, a model of RA. Testicular disruptions, as determined by the sperm DNA strand breaks, spermatocyte chromosomal analysis and spermiogram examination have been conducted by the use of standard techniques. Additionally, we aimed to test whether the anti-rheumatic effect of rituximab also decreases the cellular oxidant-antioxidant imbalance in arthritic male DBA/1 J mice. Repeated treatment of naïve control DBA/1 J mice with rituximab did not exhibit any significant deleterious effects. Moreover, repeated administration of rituximab to the arthritic DBA/1 J mice suppressed disease severity and decreased testicular disruptions. Rituximab treatment also diminished gonadal oxidative stress, through decreasing reactive oxygen species generation and restoring the reduced glutathione level in arthritic DBA/1 J mice. In conclusion, rituximab is a safe therapeutic agent and can mitigate gonadal disruptions induced by arthritis, which insinuates the importance for arthritic patients especially at reproductive age.

Effect of dihydrotestosterone on melatonin secretion and the expression of melatonin receptors and apoptosis-related factors in sheep epididymides

Melatonin (MEL) is involved in homeostasis of the epididymis lumen environment. Dihydrotestosterone (DHT) partakes in the development of gonads and organs in male animals. However, whether MEL secretion, the expression of its receptors, MT1 and MT2, and sheep epididymal epithelial cell apoptosis is regulated by DHT remains unclear. In this study, we used immunohistochemical staining to detect the distribution patterns of DHT synthetases [5α-reductase (5α-red)] and its androgen receptor (AR) in sheep epididymides. 5α-red1, 5α-red2, and AR were positively expressed in sperm, epididymal epithelial cells, and the smooth muscle cells of the caput, corpus, and cauda regions of the epididymis. DHT concentration and the expression levels of 5α-red and AR in the caput, corpus, and cauda regions were measured by enzyme-linked immunosorbent assay, liquid chromatography-mass spectrometry, real-time quantitative polymerase chain reaction, and western blot analysis. DHT concentration in the caput was significantly higher than those in corpus and cauda, probably because of the high expression of 5α-red2 in the caput and secretion and transport of DHT by the testicles. DHT inhibited MEL secretion, the expression of its membrane receptors, and MEL synthetases in cultured sheep epididymal epithelial cells in vitro. In addition, the Bax/Bcl-2 ratio, ACT CASP3, and caspase-3 mRNA expression were also decreased. The decreasing effect was partially reversed after flutamide treatment. Therefore, DHT regulates sheep epididymal function by influencing MEL expression and apoptosis-related factors. This study provides basic data for further research on the reproductive physiology of male animals.

Differential gene expression and hallmarks of stemness in epithelial cells of the developing rat epididymis

Epididymal development can be subdivided into three phases: undifferentiated, a period of differentiation, and expansion. The objectives of this study were (1) to assess gene expression profiles in epididymides, (2) predict signaling pathways, and (3) develop a novel 3D cell culture method to assess the regulation of epididymal development in vitro. Microarray analyses indicate that the largest changes in differential gene expression occurred between the 7- to 18-day period, in which 1452 genes were differentially expressed, while 671 differentially expressed genes were noted between days 18 and 28, and there were 560 differentially expressed genes between days 28 and 60. Multiple signaling pathways were predicted at different phases of development. Pathway associations indicated that in epididymides of 7- to 18-day old rats, there was a significant association of regulated genes implicated in stem cells, estrogens, thyroid hormones, and kidney development, while androgen- and estrogen-related pathways were enriched at other phases of development. Organoids were derived from CD49f + columnar cells from 7-day old rats, while no organoids developed from CD49f^- cells. Cells cultured in an epididymal basal cell organoid medium versus a commercial kidney differentiation medium supplemented with DHT revealed that irrespective of the culture medium, cells within differentiating organoids expressed p63, AQP9, and V-ATPase after 14 days of culture. The commercial kidney medium resulted in an increase in the number of organoids positive for p63, AQP9, and V-ATPase. Together, these data indicate that columnar cells represent an epididymal stem/progenitor cell population.

Early infection of Zika virus in the male reproductive system of AG129 mice: molecular and immunohistochemical evaluation

Sexual transmission of Zika virus (ZIKV), an important arbovirus, and the virus persistence in semen raise several questions about how and where it circulates in the male reproductive system (MRS). Several studies reported detection of the virus in testes, epididymis, and prostate at 5 days post-infection (dpi) or more in animal models. In the present study, we investigated the interactions of ZIKV with mouse MRS using the AG129 strain, a ZIKV permissive immunodeficient mouse strain, at two dpi. Viral RNA was detected in blood, testes, epididymis, and prostatic complexes (prostate and seminal vesicles). Immunohistochemical (IHC) analyses, based on the envelope protein, showed an early infection in organs of MRS since ZIKV positive antigens were detected in cells within or surrounding blood vessels, Sertoli, and germ cells in testes and epithelial cells in epididymis and prostate. Positive antigens for NS5 protein, the virus RNA-dependent RNA polymerase, were also detected by IHC in these organs and circulating leukocytes, suggesting that the virus replicates in these sites as early as 2 days post-infection. Analysis of the early stages of ZIKV infection in MRS may improve the current knowledge about this issue and contribute to the development of therapies directed to the infection at this site.

Calcium Homeostasis in the Epididymal Microenvironment: Is Extracellular Calcium a Cofactor for Matrix Gla Protein-Dependent Scavenging Regulated by Vitamins

In the male reproductive tract, the epididymis is an essential organ for sperm maturation, in which sperm cells acquire mobility and the ability to fertilize oocytes while being stored in a protective microenvironment. Epididymal function involves a specialized luminal microenvironment established by the epithelial cells of epididymal mucosa. Low-calcium concentration is a unique feature of this epididymal luminal microenvironment, its relevance and regulation are, however, incompletely understood. In the rat epididymis, the vitamin D-related calcium-dependent TRPV6-TMEM16A channel-coupler has been shown to be involved in fluid transport, and, in a spatially complementary manner, vitamin K2-related γ-glutamyl carboxylase (GGCX)-dependent carboxylation of matrix Gla protein (MGP) plays an essential role in promoting calcium-dependent protein aggregation. An SNP in the human GGCX gene has been associated with asthenozoospermia. In addition, bioinformatic analysis also suggests the involvement of a vitamin B6-axis in calcium-dependent MGP-mediated protein aggregation. These findings suggest that vitamins interact with calcium homeostasis in the epididymis to ensure proper sperm maturation and male fertility. This review article discusses the regulation mechanisms of calcium homeostasis in the epididymis, and the potential role of vitamin interactions on epididymal calcium homeostasis, especially the role of matrix calcium in the epididymal lumen as a cofactor for the carboxylated MGP-mediated scavenging function.

GPR64, Screened from Ewing Sarcoma Cells, Is a Potential Target for Antibody-Based Therapy for Various Sarcomas

Simple Summary

New strategies for immunotherapy have led to an increased interest in tumor-specific antigens on the cell surface in the field of oncology. Identifying markers in sarcomas is difficult because their tumor mutation burden is less than that of carcinomas. We assumed that a target protein may be acceptable as a therapeutic target, even if it is only expressed in the epididymis along with the tumor, because the epididymis has special barriers, known as the blood–epididymis barrier (BEB). We identified GPR64 as a therapeutic target for Ewing sarcoma via next-generation RNA-sequencing. GPR64 is located on the apical membranes of efferent ductules and separated from antibodies by the BEB. This study revealed, for the first time, that anti-GPR64 antibodies accumulate in various sarcomas and avoid targeting GPR64 in the epididymis in vivo. Furthermore, GPR64 is widely expressed in various sarcomas and is, therefore, a potential antibody-based therapeutic target for sarcomas.

Abstract

Ewing sarcoma is an aggressive and the second most common bone tumor in adolescent and young adult patients. The 5-year survival rate is 60–70% for localized disease but 30% for patients with metastases. Here, we aimed to identify a therapeutic target for Ewing sarcoma and evaluate antibody-based therapeutic agents using in vitro and in vivo models. We identified G protein-coupled receptor 64 (GPR64) as a therapeutic target for Ewing sarcoma via next-generation RNA-sequencing. GPR64v205 mRNA was expressed in HTB166, A673, MG63, 143B, HS-Sy II, and HT1080 cell lines as well as in Ewing sarcoma, undifferentiated pleomorphic sarcoma, leiomyosarcoma, dedifferentiated liposarcoma, and synovial sarcoma tissues. GPR64 expression was observed in 62.5% of sarcoma cases and was overexpressed in 33.9% cases. GPR64-specific monoclonal antibodies were tested as near-infrared probes for in vivo imaging using subcutaneous tumor mouse xenografts. Fluorescence intensity was stronger for the AF700-labeled anti-GPR64 antibody than that for the AF700-labeled isotype control antibody. GPR64 was detected in engrafted tumors of A673, 143B, HT1080, and the epididymis but not in other resected tissues. The anti-GPR64 antibody showed excellent binding to GPR64-positive tumors but not to healthy tissues. This antibody has potential for drug delivery in the antibody-based treatment of sarcomas.

Implications of RNA Viruses in the Male Reproductive Tract: An Outlook on SARS-CoV-2

Emerging viral infections continuously pose a threat to human wellbeing. Several RNA viruses have managed to establish access to the male reproductive tract and persist in human semen. The sexual transmission of the virus is of critical public concern. The epidemiological inferences are essential to understand its complexity, particularly the probability of viral transmission from asymptomatic patients or those in the incubation period or from the patient who was previously infected and now fully recovered. From the clinical perspective, negative impacts in the male reproductive tract associated with RNA virus infection have been described, including orchitis, epididymitis, impaired spermatogenesis, and a decrease in sperm quality, which can affect male fertility at different time intervals. The disruption of anatomical barriers due to inflammatory responses might enable the viral invasion into the testis, and the immune privilege status of testes might facilitate a sustained persistence of the virus in the semen. In this review, the current knowledge about other RNA viruses that affect male reproductive health provides the framework to discuss the impact of the SARS-CoV-2 pandemic. The molecular mechanisms, sexual transmission, and viral impacts for mumps, HIV, Zika, and Ebola viruses are explored. We discuss the currently available information on the impact of SARS-CoV-2 and its sequelae in the male reproductive tract, particularly regarding presence in semen, its impact on sexual organs, and sperm quality. To date, no sexual transmission of SARS-CoV-2 has been reported, whereas the identification of viral particles in semen remains conflicting. In the purview of the earlier conducted analyses, it is essential to investigate further the long-term health impacts of SARS-CoV-2 on the male reproductive tract.

Influence of inguinal hernia repair on sperm autoimmunity: The largest single center experience

BACKGROUND

Studies on immunological infertility after inguinal hernia correction are few and not very representative. Anti-sperm antibodies have been shown to reduce male fertility. Although the extent of infertility due to anti-sperm antibodies alone is not very clear, data indicates that about 8%-10% of infertile patients have immunological infertility DESIGN: This retrospective study includes all infertile male patients (n = 2258) who underwent mixed antiglobulin reaction tests and urologic examination from 2000 to 2020. Sperm quality (assessed by the number of spermatozoa, their motility, vitality, and normal form) was also evaluated. Among these patients, 191 had previously undergone unilateral or bilateral inguinal hernia surgery repair. The aim of the study is to evaluate if there is a higher incidence of positive mixed antiglobulin reaction test among patients undergoing inguinal hernioplasty compared to the unselected infertile population.

RESULTS

Anti-sperm antibodies would seem to increase in both patients who performed general andrological surgery and groin hernia correction, respectively 3.48 (95% Confidence Interval: 1.70-7.10; p < 0.001) and 2.45 (95% Confidence Interval: 1.01-5.99; p < 0.05) times more than the unselected infertile population.

CONCLUSIONS

Mixed antiglobulin reaction test could be useful in patients undergone previous scrotal surgery or hernia correction men, to avoid false unexplained infertility diagnoses and to direct the couple to assisted reproductive technology procedures. Basal evaluation of spermatozoa does not actually consider andrological surgery as an indication to autoimmunity investigation.

Pathogenesis of Brucella epididymoorchitis-game of Brucella death

Brucellosis is a worldwide zoonotic disease caused by Brucella spp. Human infection often results from direct contact with tissues from infected animals or by consumption of undercooked meat and unpasteurised dairy products, causing serious economic losses and public health problems. The male genitourinary system is a common involved system in patients with brucellosis. Among them, unilateral orchitis and epididymitis are the most common. Although the clinical and imaging aspect of orchi-epididymitis caused by brucellosis have been widely described, the cellular and molecular mechanisms involved in the damage and the immune response in testis and epididymis have not been fully elucidated. In this review, we first summarised the clinical characteristics of Brucella epididymo-orchitis and the composition of testicular and epididymal immune system. Secondly, with regard to the mechanism of Brucella epididymoorchitis, we mainly discussed the process of Brucella invading testis and epididymis in temporal and spatial order, including i) Brucella evades innate immune recognition of testicular PRRs；ii) Brucella overcomes the immune storm triggered by the invasion of testis through bacterial lipoproteins and virulence factors, and changes the secretion mode of cytokines; iii) Brucella breaks through the blood-testis barrier with the help of macrophages, and inflammatory cytokines promote the oxidative stress of Sertoli cells, damaging the integrity of BTB; iv) Brucella inhibits apoptosis of testicular phagocytes. Finally, we revealed the structure and sequence of testis invaded by Brucella at the tissue level. This review will enable us to better understand the pathogenesis of orchi-epididymitis caused by brucellosis and shed light on the development of new treatment strategies for the treatment of brucellosis and the prevention of transition to chronic form. Facing the testicle with immunity privilege, Brucella is like Bruce Lee in the movie Game of Death, winning is survival while losing is death.HIGHLIGHTSWe summarized the clinical features and pathological changes of Brucellaepididymoorchitis.Our research reveals the pathogenesis of Brucella epididymoorchitis, which mainly includes the subversion of testicular immune privilege by Brucella and a series of destructive reactions derived from it.As a basic framework and valuable resource, this study can promote the exploration of the pathogenesis of Brucella and provide reference for determining new therapeutic targets for brucellosis in the future.

Epididymal Sperm Granuloma and Antisperm Antibodies in Donkeys

This study aimed to describe and compare semen parameters (pre-freeze and post-freezing) and antisperm antibodies (ASA) of donkeys with epididymal sperm granuloma and healthy controls. Feral donkeys (n = 10) castrated in a concurrent study were enrolled in the present experiment. Three donkeys had unilateral granulomas, two donkeys had bilateral granulomas, whereas the remaining five had grossly normal epididymides. The granulomas were either single or multiple, firm, well-circumscribed, tan to red, and 1-5 mm in size. Upon incision, abundant, thick, tan to white-yellow fluid was recovered. Histopathology revealed epithelioid macrophages, multinucleated giant cells, and abundant sperm cell fragments with mineralized cellular debris. Each epididymis was dissected, and semen harvested for cryopreservation. Semen was assessed for sperm motility parameters, plasma membrane integrity, and mitochondrial membrane potential. All donkeys had semen cryopreserved in a standard manner. In addition, post-thaw semen from all donkeys was assessed for ASA (IgG and IgA), acrosome integrity and morphology. Post-thaw, the progressive sperm motility and the percentage of sperm with an intact plasma membrane were reduced in donkeys with sperm granuloma (P = 0.04). There was no difference in total sperm motility, morphology, or damaged acrosome across groups (P > 0.05). Three donkeys with sperm granuloma (60%) displayed increased IgG and IgA ASA. In conclusion, sperm granulomas only marginally affected sperm quality and resulted in IgG ASA binding to sperm with damaged plasma membrane. It remains to be determined if sperm granuloma and ASA affect fertility in donkeys.

Exogenous Factors Affecting the Functional Integrity of Male Reproduction

Natural processes along with increased industrial production and the irresponsible behavior of mankind have resulted in environmental pollution. Environmental pollutants can be categorized based on their characteristics and appearance into the following groups: physical, biological, and chemical. Every single one of them represents a serious threat to the male reproductive tract despite the different modes of action. Male gonads and gametes are especially vulnerable to the effect of exogenous factors; therefore, they are considered a reliable indicator of environmental pollution. The impact of xenobiotics or radiation leads to an irreversible impairment of fertility displayed by histological changes, modulated androgen production, or compromised spermatozoa (or germ cells) quality. The present article reviews the exogenous threats, male reproductive system, the mode of action, and overall impact on the reproductive health of humans and animals.

Zika virus disrupts the barrier structure and Absorption/Secretion functions of the epididymis in mice

Several studies have demonstrated that Zika virus (ZIKV) damages testis and leads to infertility in mice; however, the infection in the epididymis, another important organ of male reproductive health, has gained less attention. Previously, we detected lesions in the epididymis in interferon type I and II receptor knockout male mice during ZIKV infection. Herein, the pathogenesis of ZIKV in the epididymis was further assessed in the infected mice after footpad inoculation. ZIKV efficiently replicated in the epididymis, and principal cells were susceptible to ZIKV. ZIKV infection disrupted the histomorphology of the epididymis, and the effects were characterized by a decrease in the thickness of the epithelial layer and an increase in the luminal diameter, especially at the proximal end. Significant inflammatory cell infiltration was observed in the epididymis accompanied by an increase in the levels of interleukin (IL)-6 and IL-28. The expression of tight junction proteins was downregulated and associated with disordered arrangement of the junctions. Importantly, the expression levels of aquaporin 1 and lipocalin 8, indicators of the absorption and secretion functions of the epididymis, were markedly reduced, and the proteins were redistributed. These events synergistically altered the microenvironment for sperm maturation, disturbed sperm transport downstream, and may impact male reproductive health. Overall, these results provide new insights into the pathogenesis of the male reproductive damage caused by ZIKV infection and the possible contribution of epididymal injury into this process. Therefore, male fertility of the population in areas of ZIKV epidemic requires additional attention.

Unlike other mosquito-transmitted flaviviruses, ZIKV can persistently replicate in the male reproductive system and is sexually transmitted. ZIKV infection was reported to damage testis. However, ZIKV-induced epididymal injury was not investigated in detail. Clinically, epididymitis is closely associated with male infertility. In this study, a mouse model was used to demonstrate that ZIKV causes histomorphological and functional changes in the epididymis, which may alter the microenvironment of sperm maturation and movement and finally lead to male infertility. Therefore, long-term investigation of male reproductive health may be needed in the areas of ZIKV epidemic.

Differential Immune Response to Infection and Acute Inflammation Along the Epididymis

The epididymis is a tubular structure connecting the vas deferens to the testis. This organ consists of three main regions—caput, corpus, and cauda—that face opposing immunological tasks. A means of combating invading pathogens is required in the distally located cauda, where there is a risk of ascending bacterial infections originating from the urethra. Meanwhile, immune tolerance is necessary at the caput, where spermatozoa with immunogenic neo-antigens originate from the testis. Consistently, when challenged with live bacteria or inflammatory stimuli, the cauda elicits a much stronger immune response and inflammatory-inflicted damage than the caput. At the cellular level, a role for diverse and strategically positioned mononuclear phagocytes is emerging. At the mechanistic level, differential expression of immunoprotective and immunomodulatory mediators has been detected between the three main regions of the epididymis. In this review, we summarize the current state of knowledge about region-specific immunological characteristics and unveil possible underlying mechanisms on cellular and molecular levels. Improved understanding of the different immunological microenvironments is the basis for an improved therapy and counseling of patients with epididymal infections.

[E-Cadherine and GATA-3 are useful in the confirmation of the vas deferens in vasectomy specimens]

INTRODUCTION AND OBJECTIVES

Urologists often submit the resected tissue from vasectomies for histopathological examination in order to confirm the presence of the vas deferens. Microscopy is simple and based on haematoxylin-eosin staining; however, sample artefacts can sometimes cause confusion and immunohistochemistry can be used to identify the vas deferens.

MATERIALS AND METHODS

We investigated the utility of immunohistochemical analysis using E-cadherin and GATA-3 to confirm the presence of vas deferens epithelium in 110 vasectomy sections with different artefacts, using monoclonal antibodies and a multimer conjugated with peroxidase based technique; 5 renal arteries and 5 renal veins were stained as negative controls.

RESULTS

Membrane staining was observed for E-cadherin, which was moderate (2.7%) or strong (97.3%) in the vas deferens epithelium in all cases: 35 without artefacts, 7 with denuded epithelium, 56 with compressed/distorted epithelium, 8 with detached epithelium and 4 with displaced epithelium. GATA-3 showed moderate (31%) or strong (69%) nuclear staining in all cases, including the 76 with artefacts. In the control group, arteries and veins were negative for both markers in the endothelium, but GATA-3 occasionally stained lymphocytes in the blood vessel wall.

CONCLUSIONS

E-cadherin membrane positivity and GATA-3 nuclear expression are useful for the identification of the vas deferens in vasectomy samples containing artefacts. Vascular endothelium is negative for both markers and any possible GATA-3 staining of the lymphocytes in the blood vessel wall should not be misinterpreted.

Testis and blood-testis barrier in Covid-19 infestation: role of angiotensin-converting enzyme 2 in male infertility

Severe acute respiratory syndrome coronavirus 2 (SARS- CoV-2) that causes COVID-19 infections penetrates body cells by binding to angiotensin-converting enzyme-2 (ACE2) receptors. Evidence shows that SARS-CoV-2 can also affect the urogenital tract. Hence, it should be given serious attention when treating COVID-19-infected male patients of reproductive age group. Other viruses like HIV, mumps, papilloma and Epstein-Barr can induce viral orchitis, germ cell apoptosis, inflammation and germ cell destruction with attending infertility and tumors. The blood-testis barrier (BTB) and blood-epididymis barrier (BEB) are essential physical barricades in the male reproductive tract located between the blood vessel and seminiferous tubules in the testes. Despite the significant role of these barriers in male reproductive function, studies have shown that a wide range of viruses can still penetrate the barriers and induce testicular dysfunctions. Therefore, this mini-review highlights the role of ACE2 receptors in promoting SARS-CoV-2-induced blood-testis/epididymal barrier infiltration and testicular dysfunction.

The Immune Characteristics of the Epididymis and the Immune Pathway of the Epididymitis Caused by Different Pathogens

The epididymis is an important male accessory sex organ where sperm motility and fertilization ability develop. When spermatozoa carrying foreign antigens enter the epididymis, the epididymis shows "immune privilege" to tolerate them. It is well-known that a tolerogenic environment exists in the caput epididymis, while pro-inflammatory circumstances prefer the cauda epididymis. This meticulously regulated immune environment not only protects spermatozoa from autoimmunity but also defends spermatozoa against pathogenic damage. Epididymitis is one of the common causes of male infertility. Up to 40% of patients suffer from permanent oligospermia or azoospermia. This is related to the immune characteristics of the epididymis itself. Moreover, epididymitis induced by different pathogenic microbial infections has different characteristics. This article elaborates on the distribution and immune response characteristics of epididymis immune cells, the role of epididymis epithelial cells (EECs), and the epididymis defense against different pathogenic infections (such as uropathogenic Escherichia coli, Chlamydia trachomatis, and viruses to provide therapeutic approaches for epididymitis and its subsequent fertility problems.

An atlas of cell types in the mouse epididymis and vas deferens

Following testicular spermatogenesis, mammalian sperm continue to mature in a long epithelial tube known as the epididymis, which plays key roles in remodeling sperm protein, lipid, and RNA composition. To understand the roles for the epididymis in reproductive biology, we generated a single-cell atlas of the murine epididymis and vas deferens. We recovered key epithelial cell types including principal cells, clear cells, and basal cells, along with associated support cells that include fibroblasts, smooth muscle, macrophages and other immune cells. Moreover, our data illuminate extensive regional specialization of principal cell populations across the length of the epididymis. In addition to region-specific specialization of principal cells, we find evidence for functionally specialized subpopulations of stromal cells, and, most notably, two distinct populations of clear cells. Our dataset extends on existing knowledge of epididymal biology, and provides a wealth of information on potential regulatory and signaling factors that bear future investigation.

Distribution pattern of ZO-1 and claudins in the epididymis of vampire bats

Epithelial cells connect with each other by tight junctions (TJs) in several tissues. In epididymides, TJs proteins form the blood-epididymis barrier (BEB), which is crucial for male fertility. However, little is known about BEB morphological and physiological aspects in wild animals. This study examines the region-specific distribution pattern of TJs proteins in D. rotundus' epididymis, assessing their regulation in rainy and dry season. The expression of zonula occludens-1 (ZO-1), and claudins (Cldn)-1, -3, and -4 were evaluated by confocal immunofluorescence and ELISA analysis. Herein, ZO-1 was strictly expressed in TJs, whereas Cldns were expressed in TJs and basolateral membranes of epithelial cells. Their co-localization and intensity of expression varied in the epididymal regions examined. The effect of season on protein expression was detected mainly in TJ proteins located in the proximal regions. As such, in the initial segment (IS), Cldn-3 and -4 were detected at low levels in basolateral membranes in the rainy season compared to the dry season. Furthermore, in the distal IS, Cldn-1 expression was lower in TJs of epithelial cells during the rainy season than the dry season. ZO-1 expression was higher in the cauda region than the corpus region by ELISA analysis. Additionally, in the corpus region, ZO-1 expression was higher in TJs during dry season compared to the rainy season. Our study sheds light on the understanding of BEB in D. rotundus, improving the knowledge of their reproductive biology.

Saccharum officinarum juice alters reproductive functions in male Wistar rats

Infertility is a problem across almost all cultures and societies. Problems in the male partner, especially as a result of unhealthy dietary habits, are the commonest single group of course. Many populations, therefore, tend more toward the use of natural dietary substitutes opined to proffer less risk to reproductive functions and more health benefits. Saccharum officinarum juice (SOJ) is a widely consumed, energy-rich, nutritious substance that has many minerals and enzymes. Saccharum officinarum plant was reported to have anti-thrombosis, anti-inflammatory and immune-stimulatory activities. This study evaluated the reproductive effects of S. officinarum juice in male Wistar rats. A sugarcane press juicer was used to extract S. officinarum juice. Twenty male Wistar rats (100-120 g) grouped into four (n = 5) received 1.0 mL/kg/day distilled water (control), and 1.0, 3.2 and 10.0 mL/kg/day of fresh S. officinarum juice once daily for 8 weeks via gavage. Sperm analysis, histology of testes and epididymides were evaluated by microscopy. Enzyme-linked immunosorbent assay (ELISA) was used in assessing the serum levels of luteinizing hormone, follicle-stimulating hormone and testosterone. Data were analyzed using the analysis of variance at a significance of p < 0.05. SOJ increased fasting blood glucose levels in 3.2 and 10.0 mL/kg groups. The 10.0 mL/kg juice caused a significant increase in testosterone level and sperm count, and it also increased the percentage of aberrant sperm and decreased sperm viability. Saccharum officinarum juice impaired the histological integrity of the testes and epididymides. Thus, S. officinarum juice adversely altered the reproductive functions of male Wistar rats by reducing sperm quality and disrupting testicular architecture.

Sexual function and reproduction can be impaired in men with rheumatic diseases: A systematic review

BACKGROUND

Information about the possible effect of rheumatic diseases on male sexual function and reproduction (sexual health) is scarce and difficult to summarize. Factors known to impair sexual health, such as inflammation, medication use and hypogonadism can be present in a significant proportion of male patients with rheumatic diseases.

OBJECTIVES

The objective of our study was to systematically review the literature for the influence of paternal rheumatic disease on sexual health, such as sexual function, reproductive hormones, male fertility, pregnancy and offspring outcomes.

DATA SOURCES

English language articles identified through Embase, MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Google Scholar and the Clinical trial registries of Europe and the USA published until February 2019.

STUDY APPRAISAL AND SYNTHESIS METHODS

Literature was synthesized in narrative form and in summary tables. Outcomes were categorized as: sexual function, reproductive hormones, fertility and pregnancy and offspring outcomes. Results are presented per category and per disease.

RESULTS

9735 articles were identified with our search strategy. After removal of duplicates, excluding articles by screening titles and abstracts and assessing eligibility by reading 289 fulltext articles, 87 articles fulfilled the eligibility criteria. All included studies enrolled patients diagnosed with a rheumatic disease and had results at least on one of the outcome categories. Sexual function was the most common category, followed by reproductive hormones, fertility and pregnancy and offspring outcomes. Sexual function is impaired in a high proportion of patients with rheumatic diseases. This was statistically significant in most of the studies where a control group was available. Clinically relevant abnormalities in reproductive hormones were mainly identified in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) and a positive correlation with disease activity were reported. Semen quality in men with rheumatic diseases can be impaired in patients with SLE, SpA, sarcoidosis, BD and MWS. Sperm count and motility were the most common semen quality parameters affected. No negative effect of paternal RA and vasculitis on pregnancy outcomes were reported in 3 studies. No studies reporting the effect of paternal disease on offspring outcomes were identified.

LIMITATIONS

Most of the studies included in this review suffer from an inconsistent methodological quality, definitions of outcomes varied in several studies, a wide variety of screening questionnaires and/or diagnostic tools were used and results might only apply to the specific populations that were studied.

CONCLUSIONS

This systematic review suggests that sexual health is impaired in men with rheumatic diseases. The degree and extent of sexual health impairment vary per disease. More research is needed to fully understand the link between rheumatic diseases and impaired male sexual health. Meanwhile, rheumatologists should be aware of this association and discuss it with their patients.

IMPLICATIONS OF KEY FINDINGS

Sexual health of men with rheumatic diseases can be impaired by the disease itself. Especially in men trying to conceive, information on sexual function, reproductive hormones and sperm quality are needed to identify these problems. Treatment resulting in lower disease activity can improve overall sexual health in man with rheumatic diseases and facilitate their journey to fatherhood.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO 2018 CRD42018099845.

Importance of SLC26 Transmembrane Anion Exchangers in Sperm Post-testicular Maturation and Fertilization Potential

In mammals, sperm cells produced within the testis are structurally differentiated but remain immotile and are unable to fertilize the oocyte unless they undergo a series of maturation events during their transit in the male and female genital tracts. This post-testicular functional maturation is known to rely on the micro-environment of both male and female genital tracts, and is tightly controlled by the pH of their luminal milieus. In particular, within the epididymis, the establishment of a low bicarbonate (HCO₃^–) concentration contributes to luminal acidification, which is necessary for sperm maturation and subsequent storage in a quiescent state. Following ejaculation, sperm is exposed to the basic pH of the female genital tract and bicarbonate (HCO₃^–), calcium (Ca²⁺), and chloride (Cl^–) influxes induce biochemical and electrophysiological changes to the sperm cells (cytoplasmic alkalinization, increased cAMP concentration, and protein phosphorylation cascades), which are indispensable for the acquisition of fertilization potential, a process called capacitation. Solute carrier 26 (SLC26) members are conserved membranous proteins that mediate the transport of various anions across the plasma membrane of epithelial cells and constitute important regulators of pH and HCO₃^– concentration. Most SLC26 members were shown to physically interact and cooperate with the cystic fibrosis transmembrane conductance regulator channel (CFTR) in various epithelia, mainly by stimulating its Cl^– channel activity. Among SLC26 members, the function of SLC26A3, A6, and A8 were particularly investigated in the male genital tract and the sperm cells. In this review, we will focus on SLC26s contributions to ionic- and pH-dependent processes during sperm post-testicular maturation. We will specify the current knowledge regarding their functions, based on data from the literature generated by means of in vitro and in vivo studies in knock-out mouse models together with genetic studies of infertile patients. We will also discuss the limits of those studies, the current research gaps and identify some key points for potential developments in this field.

Effects of phthalates on bovine primary testicular culture and spermatozoa

Among environmental endocrine-active chemicals, phthalates, commonly known as plasticizers, disrupt the development of the male reproductive tract. In this study, the effects of phthalates (DIBP, BBP, DINP, DBP, DEP, DEHP and DMP) were evaluated on cultures of bovine primary male reproductive cells (n = 3) and spermatozoa (n = 4). Epididymal (caput and corpus epididymis), testicular (parenchymal and mediastinal/tubular) and vas deferens cells (VDC) were prepared from samples collected from slaughterhouse. Second part of caput epididymis which have fewer amount of principal cells, were found to be less affected compared to the first part except DEHP; while corpus epididymis was found to be more affected with IC50 values below 0.976 ng/mL (except for DEP at 4.97 ng/mL). In testicular parenchymal cells, IC50 ranged from 0.15 to 4.11 ng/mL and for mediastinum from 0.01 to 7.31 ng/mL; where cytotoxic effects were more evident in mediastinal section. Least cytotoxic and even proliferational effects (DEHP, DMP and DEP) were observed in VDC, the muscular tube carrying sperm from epididymis to the ejaculatory duct. Least spermiotoxic phthalate was DBP (3.928 ng/mL); while DINP (0.550 ng/mL) induced highest cytotoxic effect on bovine spermatozoa. Differences in the cellular structure and/or the androgen receptor distribution effect the toxicity of phthalates. Our preliminary findings on bovine spermatozoa indicate possible morphological and motility alterations; which challenges further investigation of the transition of phthalates on semen straws used in cryopreservation. Increase of exposure to environmental contaminants raise the issue of the requirement of a new perspective on reproductive health, species and tissue specific differences should further be emphasized.

Effects of co-administered melatonin, fructose and bisphenol A (BPA) on rat epididymis and sperm characteristics

Consumption of fructose-rich food and exposure to endocrine disrupting chemicals continue to increase. High fructose consumption is associated with increased incidence of dyslipidemia, hypertension, hyperuricemia and insulin resistance. Bisphenol A (BPA) is an environmental contaminant that exhibits estrogen-like activity; it impairs reproductive organs, sperm production, spermatogenesis and fertility. We investigated the possible ameliorative effects of melatonin on rat epididymis and sperm characteristics following exposure to fructose and BPA. We used 42 adult male Sprague-Dawley rats divided into seven groups. Group 1, control group, was treated with 25 mg/kg sesame oil + 25 mg/kg 0.1% ethanol. Group 2 was treated with 10% aqueous fructose. Group 3 was treated with 25 mg/kg BPA. Group 4 was treated with 10% fructose and 25 mg/kg BPA. Group 5 was treated with 10% fructose and 20 mg/kg melatonin. Group 6 was treated with 25 mg/kg BPA and 20 mg/kg melatonin. Group 7 was treated with 10% fructose, 25 mg/kg BPA and 20 mg/kg melatonin. After 60 days, epididymal tissue was removed and analyzed using histochemistry and immunohistochemistry. Sperm were counted, and sperm motility and viability were investigated. Administration of BPA caused significant damage to both epididymal tissue and sperm quality; melatonin reduced the damage, but did not prevent it completely.

Epithelial dynamics in the epididymis: role in the maturation, protection, and storage of spermatozoa

Epithelial cells line the lumen of tubular organs and are key players in their respective functions. They establish a unique luminal environment by providing a protective barrier and by performing vectorial transport of ions, nutrients, solutes, proteins, and water. Complex intercellular communication networks, specific for each organ, ensure their interaction with adjacent epithelial and non-epithelial cells, allowing them to respond to and modulate their immediate environment. In the epididymis, several epithelial cell types work in a concerted manner to establish a luminal acidic milieu that is essential for the post-testicular maturation and storage of spermatozoa. The epididymis also prevents autoimmune responses against auto-antigenic spermatozoa, while ensuring protection against ascending and blood pathogens. This is achieved by a network of immune cells that are in close contact and interact with epithelial cells. This review highlights the coordinated interactions between spermatozoa, basal cells, principal cells, narrow cells, clear cells, and immune cells that contribute to the maturation, protection, selection, and storage of spermatozoa in the lumen of the epididymis.

Airway exposure to TiO2 nanoparticles and quartz and effects on sperm counts and testosterone levels in male mice

Several types of engineered nanoparticles (ENP) have been shown to adversely affect male reproduction in rodent studies, but the airway route of exposure has been little investigated. This precludes adequate risk assessment of ENP exposure in occupational settings. Titanium dioxide nanoparticles (TiO₂ NP) have been shown to affect total sperm count in adult male mice after intravenous and oral administration. This study aimed to investigate whether also airway exposure would affect sperm counts in male mice. Mature C57BL/6J mice were intratracheally instilled with 63 μg of rutile nanosized TiO₂, once weekly for seven weeks. Respirable α-quartz (SRM1878a) was included at a similar dose level as a positive control for pulmonary inflammation. BALF cell composition showed neutrophil granulocyte influx as indication of pulmonary inflammation in animals exposed to TiO₂ NP and α-quartz, but none of the particle exposures affected weight of testes or the epididymis, sperm counts or plasma testosterone when assessed at termination of the study.

Prenatal exposure to betamethasone causes intergenerational impairment of epididymal development in the rat

BACKGROUND

Studies on epididymal toxicology are scarce. Betamethasone (BM) is a glucocorticoid used in clinical practice for antenatal therapy. We previously reported changes to testicular morphology, altered sperm quality, and fertility in adult rats following intrauterine administration of BM.

OBJECTIVES

Given that high levels of corticosteroids during gestation lead to fetal androgen depletion, and the essential role of testosterone during epididymal development, here we investigated epididymal morphology and physiology in the F1 and F2 male offspring of female rats treated with BM during gestation.

MATERIALS AND METHODS

Pregnant rats were randomly divided into two experimental groups: control (saline vehicle, n = 11) and BM-treated group (0.1 mg/kg betamethasone 21-phosphate disodium, n = 13). Rats received an intramuscular injection of vehicle or BM on gestational days 12, 13, 18, and 19. This encompasses the beginning of the critical window of male rat reproductive tract development. A subset of three males from each litter (n = 5 litters/group) was used: One rat per litter was euthanized at puberty, one was euthanized at adulthood, while the others were mated with a non-treated female to obtain the F2 generation. The same protocol described for the F1 was applied for F2, except for the mating protocol.

RESULTS

In both F1 and F2 generations, prenatal BM exposure resulted in delayed differentiation of the cauda epididymal epithelium, characterized by increased cribriform appearance on PND 45, and displayed weaker or non-detectable Cx43 immunostaining. Furthermore, in the F1 generation only, immunostaining of TP63, a transcription factor expressed in basal cells, appeared more intense with a greater number of TP63-positive cells observed in the cauda epididymis. In adults, the epithelial area was reduced in the F1 BM rats. The contractile activity of isolated epididymal ducts was comparable between groups.

DISCUSSION AND CONCLUSION

Prenatal BM exposure leads to intergenerational impairment in the development and structure of the rat epididymis.

Tissue regeneration and the epididymal stem cell

BACKGROUND

In most pseudostratified epithelia, basal cells represent a multipotent adult stem cell population. These cells generally remain in a quiescent state, until they are stimulated to respond to tissue damage by initiating epithelial regeneration. In the epididymis, cell proliferation occurs at a relatively slow rate under normal physiological conditions. Epididymal basal cells have been shown to share common properties with multipotent adult stem cells. The development of organoids from stem cells represents a novel approach for understanding cellular differentiation and characterization of stem cells.

OBJECTIVE

To review the literature on tissue regeneration in the epididymis and demonstrate the presence of an epididymal stem cell population.

METHODS

PubMed database was searched for studies reporting on cell proliferation, regeneration, and stem cells in the epididymis. Three-dimensional cell culture of epididymal cells was used to determine whether these can develop into organoids in a similar fashion to stem cells from other tissues.

RESULTS

The epididymal epithelium can rapidly regenerate following orchidectomy or efferent duct ligation, in order to maintain epithelial integrity. Studies have isolated a highly purified fraction of rat epididymal basal cells and reported that these cells displayed properties similar to those of multipotent adult stem cells. In two-dimensional cell culture conditions, these cells differentiated into cells which expressed connexin 26, a marker of columnar cells, and cytokeratin 8. Furthermore, three-dimensional cell culture of epididymal cells resulted in the formation of organoids, a phenomenon associated with the proliferation and differentiation of stem cells in vitro.

CONCLUSIONS

The rapid proliferation and tissue regeneration of the epididymal epithelium to preserve its integrity following tissue damage as well as the ability of cells to differentiate into organoids in vitro support the notion of a resident progenitor/stem cell population in the adult epididymis.

Seasonal expressions of luteinising hormone receptor, follicle-stimulating hormone receptor and prolactin receptor in the epididymis of the male wild ground squirrel (Spermophilus dauricus)

Luteinising hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) are pituitary-derived hormones and mediate their functions through LH receptor (LHR), FSH receptor (FSHR) and PRL receptor (PRLR) respectively. This study aimed to investigate the seasonal expression patterns of LHR, FSHR and PRLR in the epididymis of the male wild ground squirrel during the breeding and non-breeding seasons. Histologically, principal cells, basal cells, cilia and mature spermatozoa were found in the lumen of caput, corpus and cauda epididymidis in the breeding season, whereas in the non-breeding season, cilia and basal cells were rarely found and the epididymidal duct was devoid of spermatozoa. Immunohistochemical results showed that LHR, FSHR and PRLR were mainly present in the filamentous cytoplasm layer of epithelial cells of the caput, corpus and cauda epididymidis and FSHR and PRLR displayed stronger staining in the breeding season than in the non-breeding season. Furthermore, the mRNA and protein levels of FSHR and PRLR in all regions of epididymis as well as the levels of LHR in the caput and cauda epididymidis were higher during the breeding season. The protein levels of FSHR, LHR and PRLR were positively correlated with epididymal weight. Together, these results suggest that LHR, FSHR and PRLR may regulate epididymal functional changes in the male wild ground squirrel during its seasonal breeding cycle.

Seasonal expressions of androgen receptor, P450arom and estrogen receptors in the epididymis of the wild ground squirrel (Citellus dauricus Brandt)

The aim of this study was to investigate the seasonal expressions of androgen receptor (AR), estrogen receptors alpha and beta (ERα and ERβ) and aromatase cytochrome P450 (P450arom) in the epididymis of the wild ground squirrel. Histologically, the epididymis was with larger duct diameter and cell population during the breeding season. AR was presented in the peritubular smooth muscle cells and epithelial cells in the whole epididymis with stronger staining in the breeding period. P450arom was intensely localized in epithelial cells and spermatozoa during the breeding season, absent in the non-breeding season and moderately stained in pre-hibernation. During the breeding season, ERα was intensely expressed in epithelial cytoplasm and/or nucleus, whereas in the non-breeding season and pre-hibernation, weaker staining signal was found in nucleus of epithelial cells. ERβ was absent in the entire annual cycle by immunohistochemical and Real-time PCR detection. The mRNA levels of AR, P450arom and ERα were higher in the epididymis of the breeding season when compared to those of the non-breeding season and pre-hibernation. Taken together, these results suggest that epididymis of the wild ground squirrel is a primary target for androgen and estrogen, and the expression of P450arom represents that epididymis may be a potential source of estrogen.

Ethylene dimethane sulfonate (EDS) ablation of Leydig cells in adult rat depletes testosterone resulting in epididymal sperm granuloma: Testosterone replacement prevents granuloma formation

Sperm granuloma may develop in the epididymis following vasectomy or chemical insults. Inflammation due to sperm granuloma causes abdominal and scrotal pain. Prolonged and persistent inflammation in the epididymis due to sperm granuloma may lead to infertility. Extravasation of germ cells into the interstitium of epididymis following damage of the epididymal epithelium is one of the primary reasons for sperm granuloma-associated pathology. Since testosterone is vital for the maintenance of epididymal epithelium, we investigated the pathology of sperm granuloma and its relationship with testosterone. Adult rats were treated with a Leydig cell-specific toxicant ethylene dimethane sulfonate (EDS) to eliminate testosterone. At 7 days post-EDS, disrupted epididymal epithelium and sperm granuloma were observed in the caput epididymis. Sperm granuloma and caput were collagen-filled indicating fibrosis. Numerous round apoptotic cells were localized inside the caput lumen and dispersed through the sperm granuloma. Tnp1 (round spermatid marker) was significantly higher in the epididymis of the EDS-treated group compared to controls suggesting the apoptotic cells were round spermatids. Increases in CD68⁺ macrophages and T cells (CD4 and CD8) support an inflammatory immune infiltration in post-EDS epididymis. However, testosterone replacement following EDS prevented the sperm granuloma-associated pathology. We suggest that the immune response in the sperm granuloma may be due to the increased numbers of apoptotic round spermatids or other testicular tissue components that may be released, in addition to the regression of epididymal epithelium due to testosterone loss. Thus, testosterone replacement prevents EDS-induced sperm granuloma and ameliorates sperm granuloma-associated pathology.

Impaired male fertility and abnormal epididymal epithelium differentiation in mice lacking CRISP1 and CRISP4

Epididymal Cysteine Rich Secretory Proteins 1 and 4 (CRISP1 and CRISP4) associate with sperm during maturation and play different roles in fertilization. However, males lacking each of these molecules individually are fertile, suggesting compensatory mechanisms between these homologous proteins. Based on this, in the present work, we generated double CRISP1/CRISP4 knockout (DKO) mice and examined their reproductive phenotype. Our data showed that the simultaneous lack of the two epididymal proteins results in clear fertility defects. Interestingly, whereas most of the animals exhibited specific sperm fertilizing ability defects supportive of the role of CRISP proteins in fertilization, one third of the males showed an unexpected epididymo-orchitis phenotype with altered levels of inflammatory molecules and non-viable sperm in the epididymis. Further analysis showed that DKO mice exhibited an immature epididymal epithelium and abnormal luminal pH, supporting these defects as likely responsible for the different phenotypes observed. These observations reveal that CRISP proteins are relevant for epididymal epithelium differentiation and male fertility, contributing to a better understanding of the fine-tuning mechanisms underlying sperm maturation and immunotolerance in the epididymis with clear implications for human epididymal physiology and pathology.

Cellular junctions in the epididymis, a critical parameter for understanding male reproductive toxicology

Epididymal sperm maturation is a critical aspect of male reproduction in which sperm acquire motility and the ability to fertilize an ovum. Sperm maturation is dependent on the creation of a specific environment that changes along the epididymis and which enables the maturation process. The blood-epididymis barrier creates a unique luminal micro-environment, different from blood, by limiting paracellular transport and forcing receptor-mediated transport of macromolecules across the epididymal epithelium. Direct cellular communication between cells allows coordinated function of the epithelium. A limited number of studies have directly examined the effects of toxicants on junctional proteins and barrier function in the epididymis. Effects on the integrity of the blood-epididymis barrier have resulted in decreased fertility and, in some cases, the development of sperm granulomas. Studies have shown that in addition to tight junctions, proteins implicated in the maintenance of adherens junctions and gap junctions alter epididymal functions. This review will provide an overview of the types and roles of cellular junctions in the epididymis, and how these are targeted by different toxicants.