Tumour necrosis factor-alpha released by testicular macrophages induces apoptosis of germ cells in autoimmune orchitis

Trigonelline Chloride Ameliorated Triphenyltin-Induced Testicular Autophagy, Inflammation, and Apoptosis: Role of Recovery

Triphenyltin chloride (TPT-Cl) is an organometallic organotin. This study aimed to investigate the role of trigonelline (TG) along with the impact of TPT withdrawal on the testicular toxicity induced by TPT-Cl. Thirty-six adult male albino rats were divided into control, TG (40 mg/kg/day), TPT-Cl (0.5 mg/kg/day), TG + TPT-Cl, and recovery groups. Animals were daily gavaged for 12 weeks. Both TG and TPT-Cl withdrawal improved TPT-Cl-induced testicular toxicity features involving testis and relative testis weight reduction, luteinizing hormone, follicular stimulating hormone, and sex hormone-binding globulin elevation, reduction of inhibin B, free testosterone levels, and sperm count reduction with increased abnormal sperm forms. Moreover, both TG and TPT-Cl withdrawal reduced inflammatory activin A, follistatin, tumor necrosis factor α, interleukin-1β, and proapoptotic Bax and elevated antiapoptotic Bcl2 in testicular tissues mediated by TPT-Cl. TG and TPT-Cl withdrawal restored the excessive autophagy triggered by TPT-Cl via elevation of mTOR, AKT, PI3K, and P62/SQSTM1 and reduction of AMPK, ULK1, Beclin1, and LC3 mRNA gene expressions and regained the deteriorated testicular structure. In conclusion, TG and TPT-Cl withdrawal had an ameliorative role in partially reversing TPT-Cl-induced testicular toxicity. However, the findings indicated that the use of TG as an adjunctive factor is more favorable than TPT-Cl withdrawal, suggesting the capability of the testis for partial self-improvement.

Insights into Canine Infertility: Apoptosis in Chronic Asymptomatic Orchitis

Chronic asymptomatic orchitis (CAO) is a common cause of acquired non-obstructive azoospermia in dogs. To understand the impact and mode of action of apoptosis, we investigated TUNEL, Bax, Bcl-2, Fas/Fas ligand, and caspase 3/8/9 in testicular biopsies of CAO-affected dogs and compared the results to undisturbed spermatogenesis in healthy males (CG). TUNEL⁺ cells were significantly increased in CAO, correlating with the disturbance of spermatogenesis. Bcl-2, Bax (p < 0.01 each), caspase 9 (p < 0.05), Fas, caspase 8 (p < 0.01 each), and caspase 3 (p < 0.05) were significantly increased at the mRNA level, whereas FasL expression was downregulated. Cleaved caspase 3 staining was sporadic in CAO but not in CG. Sertoli cells, some peritubular (CAO/CG) and interstitial immune cells (CAO) stained Bcl-2⁺, with significantly more immunopositive cells in both compartments in CAO compared to CG. Bcl-2 and CD20 co-expressing B lymphocytes were encountered interstitially and in CAO occasionally also found intratubally, underlining their contribution to the maintenance of CAO. Our results support the crucial role of the intrinsic and extrinsic apoptotic pathways in the pathophysiology of canine CAO. Autoprotective Bcl-2 expression in Sertoli cells and B lymphocytes seems to be functional, however, thereby also maintaining and promoting the disease by immune cell activation.

Unraveling the effect of the inflammatory microenvironment in spermatogenesis progression

Experimental autoimmune orchitis (EAO) is a chronic inflammatory disorder that causes progressive spermatogenic impairment. EAO is characterized by high intratesticular levels of nitric oxide (NO) and tumor necrosis factor alpha (TNFα) causing germ cell apoptosis and Sertoli cell dysfunction. However, the impact of this inflammatory milieu on the spermatogenic wave is unknown. Therefore, we studied the effect of inflammation on spermatogonia and preleptotene spermatocyte cell cycle progression in an EAO context and through the intratesticular DETA-NO and TNFα injection in the normal rat testes. In EAO, premeiotic germ cell proliferation is limited as a consequence of the undifferentiated spermatogonia (CD9⁺) cell cycle arrest in G2/M and the reduced number of differentiated spermatogonia (c-kit⁺) and preleptotene spermatocytes that enter in the meiotic S-phase. Although inflammation disrupts spermatogenesis in EAO, it is maintained in some seminiferous tubules at XIV and VII-VIII stages of the epithelial cell cycle, thereby guaranteeing sperm production. We found that DETA-NO (2 mM) injected in normal testes arrests spermatogonia and preleptotene spermatocyte cell cycle; this effect reduces the number of proliferative spermatogonia and the number of preleptotene spermatocytes in meiosis S-phase (36 h after). The temporal inhibition of spermatogonia clonal amplification delayed progression of the spermatogenic wave (5 days after) finally altering spermatogenesis. TNFα (0.5 and 1 µg) exposure did not affect premeiotic germ cell cycle or spermatogenic wave. Our results show that in EAO the inflammatory microenvironment altered spermatogenesis kinetics through premeiotic germ cell cycle arrest and that NO is a sufficient factor contributing to this phenomenon.

The Role of Mononuclear Phagocytes in the Testes and Epididymis

The mononuclear phagocytic system (MPS) is the primary innate immune cell group in male reproductive tissues, maintaining the balance of pro-inflammatory and immune tolerance. This article aims to outline the role of mononuclear macrophages in the immune balance of the testes and epididymis, and to understand the inner immune regulation mechanism. A review of pertinent publications was performed using the PubMed and Google Scholar databases on all articles published prior to January 2021. Search terms were based on the following keywords: 'MPS', 'mononuclear phagocytes', 'testes', 'epididymis', 'macrophage', 'Mφ', 'dendritic cell', 'DC', 'TLR', 'immune', 'inflammation', and 'polarization'. Additionally, reference lists of primary and review articles were reviewed for other publications of relevance. This review concluded that MPS exhibits a precise balance in the male reproductive system. In the testes, MPS cells are mainly suppressed subtypes (M2 and cDC2) under physiological conditions, which maintain the local immune tolerance. Under pathological conditions, MPS cells will transform into M1 and cDC1, producing various cytokines, and will activate T cell specific immunity as defense to foreign pathogens or self-antigens. In the epididymis, MPS cells vary in the different segments, which express immune tolerance in the caput and pro-inflammatory condition in the cauda. Collectively, MPS is the control point for maintaining the immune tolerance of the testes and epididymis as well as for eliminating pathogens.

Overexpression of PD-L1 causes germ cells to slough from mouse seminiferous tubules via the PD-L1/PD-L1 interaction

Spermatogenesis is a cyclical process in which different generations of spermatids undergo a series of developmental steps at a fixed time and finally produce spermatids. Here, we report that overexpression of PD‐L1 (B7 homolog1) in the testis causes sperm developmental disorders and infertility in male mice, with severe malformation and sloughing during spermatid development, characterized by disorganized and collapsed seminiferous epithelium structure. PD‐L1 needs to be simultaneously expressed on Sertoli cells and spermatogonia to cause spermatogenesis failure. After that, we excluded the influence of factors such as the PD‐L1 receptor and humoral regulation, confirming that PD‐L1 has an intrinsic function to interact with PD‐L1. Studies have shown that PD‐L1 not only serves as a ligand but also plays a receptor‐like role in signal transduction. PD‐L1 interacts with PD‐L1 to affect the adhesive function of germ cells, causing malformation and spermatid sloughing. Taken together, these results indicate that PD‐L1 can interact with PD‐L1 to cause germ cell detachment and male infertility.

Curcumin and Mesenchymal Stem Cells Ameliorate Ankle, Testis, and Ovary Deleterious Histological Changes in Arthritic Rats via Suppression of Oxidative Stress and Inflammation

Rheumatoid arthritis (RA) is a chronic inflammatory condition, an autoimmune disease that affects the joints, and a multifactorial disease that results from interactions between environmental, genetic, and personal and lifestyle factors. This study was designed to assess the effects of curcumin, bone marrow-derived mesenchymal stem cells (BM-MSCs), and their coadministration on complete Freund's adjuvant- (CFA-) induced arthritis in male and female albino rats. Parameters including swelling of the joint, blood indices of pro-/antioxidant status, cytokines and histopathological examination of joints, and testis and ovary were investigated. RA was induced by a single dose of subcutaneous injection of 0.1 mL CFA into a footpad of the right hind leg of rats. Arthritic rats were treated with curcumin (100 mg/kg b.wt./day) by oral gavage for 21 days and/or treated with three weekly intravenous injections of BM-MSCs (1 × 10⁶ cells/rat/week) in phosphate-buffered saline (PBS). The treatment with curcumin and BM-MSCs singly or together significantly (P < 0.05) improved the bioindicators of oxidative stress and nonenzymatic and enzymatic antioxidants in sera of female rats more than in those of males. Curcumin and BM-MSCs significantly (P < 0.05) improved the elevated TNF-α level and the lowered IL-10 level in the arthritic rats. Furthermore, joint, testis, and ovary histological changes were remarkably amended as a result of treatment with curcumin and BM-MSCs. Thus, it can be concluded that both curcumin and BM-MSCs could have antiarthritic efficacies as well as protective effects to the testes and ovaries which may be mediated via their anti-inflammatory and immunomodulatory potentials as well as oxidative stress modulatory effects.

Varicocele-Mediated Male Infertility: From the Perspective of Testicular Immunity and Inflammation

Background

Varicocele (VC) is present in 35 - 40% of men with infertility. However, current surgical and antioxidant treatments are not completely effective. In addition to oxidative stress, it is likely that other factors such as testicular immune microenvironment disorder contribute to irreversible testicular. Evidence suggests that VC is associated with anti-sperm antibodies (ASAs), spermatogenesis and testosterone secretion abnormalities, and testicular cytokine production. Moreover, inhibition of inflammation can alleviate VC-mediated pathogenesis. The normal function of the testis depends on its immune tolerance mechanism. Testicular immune regulation is complex, and many infectious or non-infectious diseases may damage this precision system.

Results

The testicular immune microenvironment is composed of common immune cells and other cells involved in testicular immunity. The former includes testicular macrophages, T cells, dendritic cells (DCs), and mast cells, whereas the latter include Leydig cells and Sertoli cells (SCs). In animal models and in patients with VC, most studies have revealed an abnormal increase in the levels of ASAs and pro-inflammatory cytokines such as interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha in the seminal plasma, testicular tissue, and even peripheral blood. It is also involved in the activation of potential inflammatory pathways, such as the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing (NLRP)-3 pathway. Finally, the development of VC-mediated infertility (VMI) may be facilitated by abnormal permeability of proteins, such as claudin-11, that constitute the blood-testis barrier (BTB).

Conclusions

The testicular immune response, including the production of ASAs and inflammatory factors, activation of inflammatory pathways, and destruction of the BTB may be involved in the pathogenesis of VMI it is necessary to further explore how patient outcomes can be improved through immunotherapy.

Mumps Orchitis: Clinical Aspects and Mechanisms

The causative agent of mumps is a single-stranded, non-segmented, negative sense RNA virus belonging to the Paramyxoviridae family. Besides the classic symptom of painfully swollen parotid salivary glands (parotitis) in mumps virus (MuV)-infected men, orchitis is the most common form of extra-salivary gland inflammation. Mumps orchitis frequently occurs in young adult men, and leads to pain and swelling of the testis. The administration of MuV vaccines in children has been proven highly effective in reducing the incidence of mumps. However, a recent global outbreak of mumps and the high rate of orchitis have recently been considered as threats to male fertility. The pathogenesis of mumps orchitis remains largely unclear due to lack of systematic clinical data analysis and animal models studies. The alarming increase in the incidence of mumps orchitis and the high risk of the male fertility have thus become a major health concern. Recent studies have revealed the mechanisms by which MuV-host cells interact and MuV infection induces inflammatory responses in testicular cells. In this mini-review, we highlight advances in our knowledge of the clinical aspects and possible mechanisms of mumps orchitis.

Involvement of Cytokines and Hormones in the Development of Spermatogenesis In Vitro from Spermatogonial Cells of Cyclophosphamide-Treated Immature Mice

Aggressive chemotherapy treatment may lead to male infertility. Prepubertal boys do not produce sperm at this age, however, they have spermatogonial stem cells in their testes. Here, we examined the effect of intraperitoneal injection of cyclophosphamide (CP) on the capacity of immature mice (IM) to develop spermatogenesis in vivo and in vitro [using methylcellulose culture system (MCS)]. Our results show a significant decrease in testicular weight, total number of testicular cells, and the number of Sertoli, peritubular, premeiotic, and meiotic/post-meiotic cells, but an increase in the percentages of damaged seminiferous tubules in CP-treated IM compared to control. The functionality of Sertoli cells was significantly affected. The addition of testosterone to isolated cells from seminiferous tubules of CP-treated IM significantly increased the percentages of premeiotic (CD9-positive cells) and meiotic/post-meiotic cells (ACROSIN-positive cells) developed in MCS compared to control. The addition of FSH did not affect developed cells in MCS compared to control, but in combination with testosterone, it significantly decreased the percentages of CD9-positive cells and ACROSIN-positive cells. The addition of IL-1 did not affect developed cells in MCS compared to control, but in combination with testosterone, it significantly increased the percentages of VASA-positive cells and BOULE-positive cells compared to IL-1 or testosterone. Addition of TNF significantly increased only CD9-positive cells in MCS compared to control, but in combination with testosterone, it significantly decreased ACROSIN-positive cells compared to testosterone. Our results show a significant impairment of spermatogenesis in the testes of CP-treated IM, and that spermatogonial cells from these mice proliferate and differentiate to meiotic/post-meiotic cells under in vitro culture conditions.

Bisphenol A exposure increases epididymal susceptibility to infection in mice

Male fertility is linked with several well-orchestrated events including spermatogenesis, epididymal maturation, capacitation, the acrosome reaction, fertilization, and beyond. However, the detrimental effects of bisphenol A (BPA) on sperm maturation compared to spermatogenesis and sperm cells remain unclear. Therefore, this study was to investigate whether pubertal exposure to BPA induces male infertility via interruption of the immune response in the epididymis. CD-1 male mice (5 weeks old) were treated daily with vehicle (corn oil) and 50 mg BPA/kg-BW for 6 weeks by oral gavage. Following BPA exposure, we observed decreased intraepithelial projection of basal cells, indicative of changes to the luminal environment. We also observed decreased projection of macrophages and protrusion of apoptotic cells into the lumen induced by incomplete phagocytosis of apoptotic cells in the caput epididymis. Exposure to BPA also reduced the anti- and pro-inflammatory cytokines IL-10, IL-6, IFN-γ, and IL-7 in the epididymis, while the chemotaxis-associated cytokines CCL12, CCL17, CXCL16, and MCP-1 increased. This study suggests two possible mechanisms for BPA induction of male infertility. First, exposure to BPA may induce an imbalance of immune homeostasis by disrupting the ability of basal cells to perceive environmental changes. Second, exposure to BPA may lead to collapse of macrophage phagocytosis via downregulation of intraepithelial projection and inflammatory-related cytokines. In conclusion, the observed potential pathways can lead to autoimmune disorders such epididymitis and orchitis.

The impact of SARS-CoV-2 and COVID-19 on male reproduction and men's health

Many couples initially deferred attempts at pregnancy or delayed fertility care due to concerns about coronavirus disease 2019 (COVID-19). One significant fear during the COVID-19 pandemic was the possibility of sexual transmission. Many couples have since resumed fertility care while accepting the various uncertainties associated with severe acute respiratory syndrome coronavirus 2, including the evolving knowledge related to male reproductive health. Significant research has been conducted exploring viral shedding, tropism, sexual transmission, the impact of male reproductive hormones, and possible implications to semen quality. However, to date, limited definitive evidence exists regarding many of these aspects, creating a challenging landscape for both patients and physicians to obtain and provide the best clinical care. This review provides a comprehensive assessment of the evolving literature concerning COVID-19 and male sexual and reproductive health, and guidance for patient counseling.

Immunologic Environment of the Testis

Mammalian spermatogenesis is a carefully orchestrated male germ cell differentiation process by which spermatogonia differentiate to spermatozoa in the testis. A highly organized testicular microenvironment is therefore necessary to support spermatogenesis. Regarding immunologic aspects, the testis adapts a specialized immune environment for the protection of male germ cells and testicular functions. The mammalian testis possesses two immunologic features: (1) it is an immunoprivileged organ where immunogenic germ cells do not induce deleterious immune responses under physiologic conditions; and (2) it creates its own effective innate defense system against microbial infection. Various pathologic conditions may disrupt testicular immune homeostasis, thereby resulting in a detrimental immune response and perturbing testicular functions, one of the etiologic factors of male infertility. Understanding the mechanisms underlying immunoregulation in the testis can aid in establishing strategies for the prevention and therapy of immunologic testicular dysfunction and male infertility. This chapter focuses on the mechanisms underlying immune privilege, local innate immunity, and immunologic diseases of the testis.

Successful activation of rat T lymphocytes by sperm specific antigens in vitro

Autoimmune orchitis is a condition related to cellular immunity. A disease model involving transfer of T lymphocytes activated by known antigens would be useful for defining pathogenical molecules. Since no method for activating rat T cells using specific antigens is available, we started the study to develop the method. T cells were collected from draining lymph nodes of immunized rats, then co-cultured with syngeneic splenocytes as antigen-presenting cells (APC) in antigen-supplemented medium (= stimulation). The cells were then incubated in medium without antigens and APC (= resting). Repetitive stimulation and resting increased the number of the T cells more than 100-fold. The antigen-specific activation was demonstrated by cell proliferation assay and ELISA assay for interferon gamma. Flow cytometry revealed that > 95% of the cells expressed tumor necrosis factor alpha, a cytokine responsible for autoimmune orchitis. The present method will provide a new procedure to evaluate antigenicity of sperm molecules.

Hypogonadism and cancer survivorship

PURPOSE OF REVIEW

Hypogonadism is highly prevalent among not only patients with a history of prior treatment for cancer, but also among those patients with a new oncologic diagnosis who have not yet received any cancer therapy. Hypogonadism can cause a wide array of signs and symptoms including: deceased muscle mass; increased fat mass; decreased energy, mood, and overall sense of well being; diminished bone mineral density; infertility; and impaired libido and sexual function. This purpose of this manuscript is to review the mechanisms by which cancer and oncologic treatment regimens can adversely affect the hypothalamic pituitary gonadal axis, resulting in hypogonadism. Risks and benefits associated with the treatment of testosterone deficiency are also discussed, which are important considerations for clinicians caring for affected patients.

RECENT FINDINGS

Hypogonadism has a high prevalence in the setting of cancer and is an important survivorship issue. Recent randomized controlled trials confirm testosterone's therapeutic benefits in terms of sexual function, mood body composition, and bone health, but the specific benefits in terms of quality of life are less clear.

SUMMARY

More prospective studies are needed to further delineate the risks, benefits, and overall outcomes of testosterone replacement therapy in patients with cancer and cancer survivors.

Pathomechanisms of Autoimmune Based Testicular Inflammation

Infection and inflammation of the male reproductive tract are relevant causes of infertility. Inflammatory damage occurs in the special immunosuppressive microenvironment of the testis, a hallmark termed testicular immune privilege, which allows tolerance to neo-antigens from developing germ cells appearing at puberty, long after the establishment of systemic immune tolerance. Experimental autoimmune orchitis (EAO) is a well-established rodent model of chronic testicular inflammation and organ specific autoimmunity that offers a valuable in vivo tool to investigate the pathological and molecular mechanisms leading to the breakdown of the testicular immune privilege. The disease is characterized by the infiltration of the interstitium by immune cells (mainly macrophages, dendritic cells, and T cells), formation of autoantibodies against testicular antigens, production of pro-inflammatory mediators such as NO, MCP1, TNFα, IL6, or activins and dysregulation of steroidogenesis with reduced levels of serum testosterone. EAO leads to sloughing of germ cells, atrophic seminiferous tubules and fibrotic remodeling, parameters all found similarly to changes in human biopsies from infertile patients with inflammatory infiltrates. Interestingly, testosterone supplementation during the course of EAO leads to expansion of the regulatory T cell population and inhibition of disease development. Knowledge of EAO pathogenesis aims to contribute to a better understanding of human testicular autoimmune disease as an essential prerequisite for improved diagnosis and treatment.

Interplay between male reproductive system dysfunction and the therapeutic effect of flavonoids

Male infertility has affected many families around the world. However, due to the mechanism underlying male reproductive system dysfunction are not completely elucidated, the use of drugs for male reproductive system dysfunction treatment only insignificant higher pregnancy outcomes, low-quality evidence suggests that clinical pregnancy rates may increase. Therefore, the focus in the future will be on developing more viable treatment options to prevent or treatment of male reproductive system dysfunction and achieve the purpose of improving fertility. Interestingly, natural products, as the potential inhibitors for the treatment of male reproductive system dysfunction, have shown a good therapeutic effect. Among many natural products, flavonoids have been extensively investigated for the treatment of male reproductive system dysfunction, such as testicular structural disruption, spermatogenesis disturbance and sperm quality decline. Flavonoids have been reported to have antioxidant, anti-inflammatory, immune stimulating, anti-apoptotic, anticarcinogenic, anti-allergic and antiviral activities, investigating for the treatment of male reproductive system dysfunction. In this review, we evaluate the therapeutic effects of flavonoids on male reproductive system dysfunction under different cellular scenarios and summarize the therapeutic strategies of flavonoids based on the aforementioned retrospective analysis. In the end, we describe some perspective research areas relevant to the application of flavonoids in the treatment of male reproductive system dysfunction.

A critical role of foxp3a-positive regulatory T cells in maintaining immune homeostasis in zebrafish testis development

Suppressive regulatory T cells (Treg cells) play a vital role in preventing autoimmunity and restraining excessive immune response to both self- and non-self-antigens. Studies on humans and mice show that the Forkhead box p3 (Foxp3) is a key regulatory gene for the development and function of Treg cells. In zebrafish, Treg cells have been identified by using foxp3a as a reliable marker. However, little is known about the function of foxp3a and Treg cells in gonadal development and sex differentiation. Here, we show that foxp3a is essential for maintaining immune homeostasis in zebrafish testis development. We found that foxp3a was specifically expressed in a subset of T cells in zebrafish testis, while knockout of foxp3a led to deficiency of foxp3a-positive Treg cells in the testis. More than 80% of foxp3a^-/- mutants developed as subfertile males, and the rest of the mutants developed as fertile females with decreased ovulation. Further study revealed that foxp3a^-/- mutants had a delayed juvenile ovary-to-testis transition in definite males and sex reversal in about half of the definite females, which led to a dominance of later male development. Owing to the absence of foxp3a-positive Treg cells in the differentiating testis of foxp3a^-/- mutants, abundant T cells and macrophages expand to disrupt an immunosuppressive milieu, resulting in defective development of germ cells and gonadal somatic cells and leading to development of infertile males. Therefore, our study reveals that foxp3a-positive Treg cells play an essential role in the orchestration of gonadal development and sex differentiation in zebrafish.

Pattern recognition receptor-mediated innate immune responses in seminal vesicle epithelial cell and their impacts on cellular function†

The seminal vesicles can be infected by microorganisms, thereby resulting in vesiculitis and impairment in male fertility. Innate immune responses in seminal vesicles cells to microbial infections, which facilitate vesiculitis, have yet to be investigated. The present study aims to elucidate pattern recognition receptor-mediated innate immune responses in seminal vesicles epithelial cells. Various pattern recognition receptors, including Toll-like receptor 3, Toll-like receptor 4, cytosolic ribonucleic acid, and deoxyribonucleic acid sensors, are abundantly expressed in seminal vesicles epithelial cells. These pattern recognition receptors can recognize their respective ligands, thus activating nuclear factor kappa B and interferon regulatory factor 3. The pattern recognition receptor signaling induces expression of pro-inflammatory cytokines, such as tumor necrosis factor alpha (Tnfa) and interleukin 6 (Il6), chemokines monocyte chemoattractant protein-1 (Mcp1) and C-X-C motif chemokine 10 (Cxcl10), and type 1 interferons Ifna and Ifnb. Moreover, pattern recognition receptor-mediated innate immune responses up-regulated the expression of microsomal prostaglandin E synthase and cyclooxygenase 2, but they down-regulated semenogelin-1 expression. These results provide novel insights into the mechanism underlying vesiculitis and its impact on the functions of the seminal vesicles.

Cisplatin induced testicular damage through mitochondria mediated apoptosis, inflammation and oxidative stress in rats: impact of resveratrol

The target of this study was to explore the role of mitochondria mediated apoptosis and inflammation in cisplatin-induced testicular damage and to evaluate the ameliorative effect of resveratrol. Adult male Wistar rats were randomly allocated to 4 groups. Group I (Control) received normal saline, Group II (Resveratrol) received resveratrol (50 mg/kg/day), Group III (Cisplatin) received cisplatin (7.5 mg/kg/week, i.p.) and Group IV (Resveratrol + Cisplatin) received resveratrol and cisplatin in the same regimen of treatment. Treatment with resveratrol in Groups II and IV started 48h before cisplatin injection and continued for further 4 successive weeks. Cisplatin-treated rats showed reduced body weight, absolute testes weight and sperm count, motility and viability. On the other hand, cisplatin treatment increased the percentage of sperm abnormalities. It also decreased serum testosterone level, mitochondrial membrane potential while, increased cytochrome C liberation from the mitochondria into the cytosol. The activities of caspase-3 & -9 were increased. The level of TNF-α, IL-6 and Bax were increased whereas Bcl-2 was decreased. Oxidative stress markers were found to increase with a concomitant reduction in the antioxidant enzymes and GSH levels. These results were confirmed by immunohistochemical and histopathological analysis. Contrary to all these results, there were improvements in cisplatin induced testicular damage through attenuation of mitochondria mediated apoptosis, inflammation, and oxidative stress owing to resveratrol pretreatment. Thus, resveratrol, as a potential therapeutic agent, may hold promise in preventing mitochondria mediated apoptosis and inflammation in cisplatin-induced testicular damage in rats.

Investigation of activin A in inflammatory responses of the testis and its role in the development of testicular fibrosis

STUDY QUESTION

Does activin A contribute to testicular fibrosis under inflammatory conditions?

SUMMARY ANSWER

Our results show that activin A and key fibrotic proteins are increased in human testicular biopsies with leukocytic infiltrates and impaired spermatogenesis and in murine experimental autoimmune orchitis (EAO) and that activin A stimulates fibrotic responses in peritubular cells (PTCs) and NIH 3T3 fibroblasts.

WHAT IS KNOWN ALREADY

Fibrosis is a feature of EAO. Activin A, a regulator of fibrosis, was increased in testes of mice with EAO and its expression correlated with severity of the disease.

STUDY DESIGN, SIZE, DURATION

This is a cross-sectional and longitudinal study of adult mice immunized with testicular homogenate (TH) in adjuvant to induce EAO, collected at 30 (n = 6), 50 (n = 6) and 80 (n = 5) days after first immunization. Age-matched mice injected with adjuvant alone (n = 14) and untreated mice (n = 15) were included as controls. TH-immunized mice with elevated endogenous follistatin, injected with a non-replicative recombinant adeno-associated viral vector carrying a gene cassette of follistatin (rAAV-FST315; n = 3) or vector with an empty cassette (empty vector controls; n = 2) 30 days prior to the first immunization, as well as appropriate adjuvant (n = 2) and untreated (n = 2) controls, were also examined.Human testicular biopsies showing focal inflammatory lesions associated with impaired spermatogenesis (n = 7) were included. Biopsies showing intact spermatogenesis without inflammation, from obstructive azoospermia patients, served as controls (n = 7).Mouse primary PTC and NIH 3T3 fibroblasts were stimulated with activin A and follistatin 288 (FST288) to investigate the effect of activin A on the expression of fibrotic markers. Production of activin A by mouse primary Sertoli cells (SCs) was also investigated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Testicular RNA and protein extracts collected from mice at days 30, 50 and 80 after first immunization were used for analysis of fibrotic marker genes and proteins, respectively. Total collagen was assessed by hydroxyproline assay and fibronectin; collagen I, III and IV, α-smooth muscle actin (α-SMA) expression and phosphorylation of suppressor of mothers against decapentaplegic (SMAD) family member 2 were measured by western blot. Immunofluorescence was used to detect fibronectin. Fibronectin (Fn), αSMA (Acta2), collagen I (Col1a2), III (Col3a1) and IV (Col4a1) mRNA in PTC and NIH 3T3 cells treated with activin A and/or FST288 were measured by quantitative RT-PCR (qRT-PCR). Activin A in SC following tumour necrosis factor (TNF) or FST288 stimulation was measured by ELISA. Human testicular biopsies were analysed by qRT-PCR for PTPRC (CD45) and activin A (INHBA), hydroxyproline assay and immunofluorescence.

MAIN RESULTS AND THE ROLE OF CHANCE

Production of activin A by SC was stimulated by 25 and 50 ng/ml TNF (P < 0.01, P < 0.001, respectively) as compared to untreated cells. INHBA mRNA was increased in human testicular biopsies with leukocytic infiltrates and impaired spermatogenesis, compared with control biopsies (P < 0.05), accompanied by increased total collagen (P < 0.01) and fibronectin deposition. Total testicular collagen (P < 0.0001) and fibronectin protein expression (P < 0.05) were also increased in EAO, and fibronectin expression was correlated with the severity of the disease (r = 0.9028). In animals pre-treated with rAAV-FST315 prior to immunization with TH, protein expression of fibronectin was comparable to control. Stimulation of PTC and NIH 3T3 cells with activin A increased fibronectin mRNA (P < 0.05) and the production of collagen I (P < 0.001; P < 0.01) and fibronectin (P < 0.05). Moreover, activin A also increased collagen IV mRNA (P < 0.05) in PTC, while αSMA mRNA (P < 0.01) and protein (P < 0.0001) were significantly increased by activin A in NIH 3T3 cells.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

A limited number of human testicular specimens was available for the study. Part of the study was performed in vitro, including NIH 3T3 cells as a surrogate for testicular fibroblasts.

WIDER IMPLICATIONS OF THE FINDINGS

Resident fibroblasts and PTC may contribute to the progression of testicular fibrosis following inflammation, and activin A is implicated as a key mediator of this process.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Health and Medical Research Council of Australia, the Victorian Government's Operational Infrastructure Support Program and the International Research Training Group between Justus Liebig University (Giessen) and Monash University (Melbourne) (GRK 1871/1-2) on `Molecular pathogenesis on male reproductive disorders' funded by the Deutsche Forschungsgemeinschaft and Monash University. The authors declare no competing financial interests.

Metformin Ameliorates Testicular Function and Spermatogenesis in Male Mice with High-Fat and High-Cholesterol Diet-Induced Obesity

The aim of this study was to investigate the effects of metformin supplementation on metabolic dysfunction, testicular antioxidant capacity, apoptosis, inflammation and spermatogenesis in male mice with high-fat and high-cholesterol diet-induced obesity. Forty male C57BL/6 mice were fed a normal diet (NC group, n = 10) or a high-fat and high-cholesterol diet (HFC group, n = 30) for 24 weeks, and mice randomly chosen from the HFC group were later treated with metformin for the final 8 weeks of HFC feeding (HFC + Met group, n = 15). Compared with the HFC group, the obese mice supplemented with metformin exhibited improved blood cholesterol, glucose and insulin resistance. The HFC group diminishes in the sperm motility and normal sperm morphology, while the poorer maturity of testicular spermatogenesis was improved by metformin treatment. The HFC group exhibited a higher estradiol level and a lower 17β-HSD protein expression. Further analyses showed that metformin treatment increased the activities of superoxide dismutase, catalase and glutathione peroxidase and reduced lipid peroxidation. Nevertheless, both the HFC and HFC + Met groups exhibited increased expressions of apoptosis and inflammation proteins in the testis. Metformin treatment ameliorated obesity-induced poor testicular spermatogenesis and semen quality through increasing the testosterone level and antioxidant capacity.

Oncofertility in adult and pediatric populations: options and barriers

Cancer and its treatments can affect fertility in a variety of ways, and recent advances in cancer detection and treatment have led to an increasing number of cancer survivors for whom future fertility is a primary concern. Oncofertility is the study of interactions between cancer, anti-cancer therapy, fertility, and reproductive health. Fertility preservation aims to optimize fertility potential before initiation of gonadotoxic therapies. Sperm cryopreservation from an ejaculated sample is the gold standard for adults and post-pubertal adolescents, though added maneuvers such as medical therapy, penile vibratory stimulation, and electroejaculation can be employed when appropriate. When all these approaches fail, testicular sperm extraction can be used to obtain and cryopreserve testicular sperm from the azoospermic patient. Fertility preservation in the pre-pubertal pediatric patient is still experimental, but recent scientific breakthroughs with use of spermatogonial stem cells and testicular tissue transplantation offer great promise for the future. While there may be several practical, cultural, religious, and other barriers to fertility preservation, the establishment of a dedicated fertility preservation team can help to overcome these obstacles and optimize the utilization of fertility preservation in cancer patients of all ages.

From Ancient to Emerging Infections: The Odyssey of Viruses in the Male Genital Tract

The male genital tract (MGT) is the target of a number of viral infections that can have deleterious consequences at the individual, offspring, and population levels. These consequences include infertility, cancers of male organs, transmission to the embryo/fetal development abnormalities, and sexual dissemination of major viral pathogens such as human immunodeficiency virus (HIV) and hepatitis B virus. Lately, two emerging viruses, Zika and Ebola, have additionally revealed that the human MGT can constitute a reservoir for viruses cleared from peripheral circulation by the immune system, leading to their sexual transmission by cured men. This represents a concern for future epidemics and further underlines the need for a better understanding of the interplay between viruses and the MGT. We review here how viruses, from ancient viruses that integrated the germline during evolution through old viruses (e.g., papillomaviruses originating from Neanderthals) and more modern sexually transmitted infections (e.g., simian zoonotic HIV) to emerging viruses (e.g., Ebola and Zika) take advantage of genital tract colonization for horizontal dissemination, viral persistence, vertical transmission, and endogenization. The MGT immune responses to viruses and the impact of these infections are discussed. We summarize the latest data regarding the sources of viruses in semen and the complex role of this body fluid in sexual transmission. Finally, we introduce key animal findings that are relevant for our understanding of viral infection and persistence in the human MGT and suggest future research directions.

Fluoride Induces Autoimmune Orchitis Involved with Enhanced IL-17A Secretion in Mice Testis

Fluoride (F) widely exists in the water and food. Recent studies reported that F induced testicular toxicity via inflammation reaction. This study was aimed to explore the mechanism of F-induced inflammation in testis. 100 healthy male mice (BALB/cJ strain) were randomly divided into five groups including: control, experimental autoimmune orchitis (EAO), and three F groups (25, 50, and 100 mg/L sodium fluoride (NaF)). After 150 d, the results showed a significant increase in testicular cytokines levels including of IL-17A, IL-6, IFN-γ, and TNF-α in NaF and EAO groups compared with control group. Interestingly, the presence of specific antisperm autoantibodies in antitesticular autoantibodies and the notable recruitment of immunocyte (T cells and dendritic cells) were also observed in NaF and EAO groups. In addition, findings showed that in NaF and EAO groups macrophages and T cells both significantly secreted IL-17A, and the protein and mRNA levels of cytokines (IL-6 and TGF-β) were significantly increased. From these results, it can be concluded that autoimmune orchitis and IL-17A are implicated in F-induced testicular inflammation.

The inflammatory mediators TNFα and nitric oxide arrest spermatogonia GC-1 cell cycle

During an inflammatory process of the testis, the network of somatic, immune, and germ cell interactions is altered leading to organ dysfunction. In testicular biopsies of infertile men, spermatogenesis impairment is associated with reduced spermatogonia proliferation, increased number of immune cells, and content of pro-inflammatory cytokines. TNFα-TNFR and nitric oxide (NO)-NO synthase systems are up-regulated in models of testicular damage and in human testis with maturation arrest. The purpose of this study was to test the hypothesis that TNFα-TNFR system and NO alter the function of spermatogonia in the inflamed testis. We studied the effect of TNFα and NO on GC-1 spermatogonia cell cycle progression and death by flow cytometry. GC-1 cells expressed TNFR1 and TNFR2 (immunofluorescence). TNFα (10 and 50 ng/ml) and DETA-Nonoate (0.5 and 2 mM), a NO releaser, increased the percentage of cells in S-phase of the cell cycle and reduced the percentage in G1, inducing also cell apoptosis. TNFα effect was not mediated by oxidative stress unlike NO, since the presence of N-acetyl-l-cysteine (2.5 and 5.0 mM) prevented NO induced cell cycle arrest and death. GC-1 spermatogonia overpass NO induced cell cycle arrest but no TNFα, since after removal of NO, spermatogonia progressed through the cell cycle. We propose TNFα and NO might contribute to impairment of spermatogenesis by preventing adequate functioning of the spermatogonia population. Our results showed that TNFα and NO impaired spermatogonia cell cycle, inducing GC-1 arrest in the S phase.

Alteration of testicular regulatory and functional molecules following long-time exposure to 900 MHz RFW emitted from BTS

The aim of this investigation was to evaluate changes in testosterone and some of the functional and regulatory molecules of testis such as P450scc, steroidogenic acute regulatory protein (StAR), tumour necrosis factor-α (TNF-α), interleukin-1α (IL-1α), interleukin-1β (IL-1β) and nerve growth factor (NGF) following exposure to 900 MHz radio frequency (RF). Thirty adult male Sprague Dawley rats (190 ± 20 g BW) were randomly classified in three equal groups, control (sham, without any exposure), short-time exposure (2 hr) (STE) and long-time exposure (4 hr) (LTE). The exposure was performed for 30 consecutive days. The testosterone level in both exposed groups was significantly less than control (p < .05). Level of TNF-α in both exposed groups was significantly greater than control (p < .05). IL-1α and NGF levels in LTE were significantly higher than the STE and control groups (p < .05). Level of IL-1β in LTE was significantly higher than control (p < .05). Expression of both P450scc and StAR mRNA was significantly down-regulated in both exposed groups compared to control (p < .05). Our results showed that RFW can affect testis and reproductive function through changes in factors, which are important during steroidogenesis, and also through changes in inflammatory factors, which regulate Leydig cell functions.

Viral threat to male fertility

The detrimental effects of Zika virus (ZIKV) infection on mouse testicular functions have reminded a viral threat to male fertility. A broad range of virus families has tropism for male reproductive system, particularly the testes. Certain virus types of these viruses, such as mumps virus and human immunodeficiency virus (HIV), may severely damage the testes and consequently lead to male infertility. ZIKV has been recently found to damage testicular functions and lead to male infertility in mice. Many other viruses also have detrimental effects on host reproduction. Public attention has been paid to sexually transmitted viruses, such as HIV and hepatitis B and C viruses in humans and likewise in economically important farm animals. This article provides an overview on main viruses affecting the male reproductive system and their detrimental effects on fertility, and outlines some important issues for future study.

MEHP-induced rat testicular inflammation does not exacerbate germ cell apoptosis

The testis is an organ that maintains an immune suppressive environment. We previously revealed that exposure of pre-pubertal rats to an acute dose of a well-described Sertoli cell toxicant, mono-(2-ethylhexyl) phthalate (MEHP), leads to an accumulation of CD11b+ immune cells in the testicular interstitial space that closely correlates with a robust incidence of germ cell (GC) apoptosis. Here, we test the hypothesis that the infiltrating immune cells contribute to GC apoptosis. Postnatal day 28 Fischer rats that received an oral dose of 700 mg/kg MEHP showed a significant infiltration of both CD11bc+/CD68+/CD163- macrophages and neutrophils. The infiltration peaked at 12 h, but had reduced by 48 h. Testicular macrophages from MEHP-treated rats showed significantly upregulated expression of Tnfa and Il6, and the Arg1/Nos2 ratio was reduced compared to controls. However, small increases in anti-inflammatory genes Il10 and Tgfb1 were also observed. Depletion of circulating monocytes with clodronate liposomes prior to MEHP treatment reduced the macrophage influx into the testis, but did not lower GC apoptosis. Additionally, depletion of neutrophils using an anti-polymorphonuclear cell antibody prevented both macrophage and neutrophil infiltration into the testis, and also did not affect GC apoptosis. Together, these results show that exposure to MEHP leads to a rapid and temporary influx of pro-inflammatory monocytes and neutrophils in the interstitium of the testis. However, with this acute dosing paradigm, these infiltrating leukocytes do not appear to contribute to MEHP-induced testicular GC apoptosis leaving the functional significance of these infiltrating cells in the pathogenesis of MEHP-induced testicular injury unresolved.

Galectin-1 enhances TNFα-induced inflammatory responses in Sertoli cells through activation of MAPK signalling

Galectin-1 (Gal-1) is a pleiotropic lectin involved in the modulation of immune responses. Using a model of rat experimental autoimmune orchitis (EAO), we investigated the role of Gal-1 in testicular inflammation. EAO is characterized by leukocytic infiltrates in the interstitium, damage of spermatogenesis and production of inflammatory mediators like TNFα and MCP1 causing infertility. In normal rat testis Gal-1 was mainly expressed in Sertoli cells and germ cells. In the inflamed testis, Gal-1 expression was significantly downregulated most likely due to germ cell loss. Analyses of lectin binding and expression of glucosaminyl- and sialyltransferases indicated that the glycan composition on the cell surface of Sertoli and peritubular cells becomes less favourable for Gal-1 binding under inflammatory conditions. In primary Sertoli cells Gal-1 expression was found to be upregulated after TNFα challenge. Pretreatment with Gal-1 synergistically and specifically enhanced TNFα-induced expression of MCP1, IL-1α, IL-6 and TNFα in Sertoli cells. Combined stimulation of Sertoli cells with Gal-1 and TNFα enhanced the phosphorylation of MAP kinases as compared to TNFα or Gal-1 alone. Taken together, our data show that Gal-1 modulates inflammatory responses in Sertoli cells by enhancing the pro-inflammatory activity of TNFα via stimulation of MAPK signalling.

Protective influence of rosiglitazone against testicular ischaemia-reperfusion injury in rats

Testicular torsion is a urology urgent disease which causes testicular injury and potential sterility. In this study, we explored the protective influence of rosiglitazone on testicular ischaemia-reperfusion damage. There were 28 male Sprague Dawley rats in total, which were assigned randomly to four groups. Group A was blank control one; group B was testicular injury one; group C was rosiglitazone one; group D was rosiglitazone antagonist one. The testicles were counter-rotated after 2 hr and then underwent orchiectomy 24 hr later. We found that testicular tissue structure of rats was seriously damaged in groups B and D. However, group C had better testicular architecture. Similar findings were also shown for lipid peroxidation by evaluating the MDA activity (p < .05). Unlike group B or group D, the levels of inflammation by evaluating the MPO activity, the levels of TNF-a, IL-1 and IL-6 and the expressions of ICAM-1 were prominently lower in group C (p < .05) as well. So our researches demonstrated that rosiglitazone significantly decreased the amount of responsive oxygen radical and regulated inflammatory responses. Rosiglitazone had a protective influence against testicular ischaemia-reperfusion injury in rats and possibly depended on its anti-inflammatory and antioxidant traits.

C-X-C motif chemokine ligand 10 produced by mouse Sertoli cells in response to mumps virus infection induces male germ cell apoptosis

Mumps virus (MuV) infection usually results in germ cell degeneration in the testis, which is an etiological factor for male infertility. However, the mechanisms by which MuV infection damages male germ cells remain unclear. The present study showed that C-X-C motif chemokine ligand 10 (CXCL10) is produced by mouse Sertoli cells in response to MuV infection, which induces germ cell apoptosis through the activation of caspase-3. CXC chemokine receptor 3 (CXCR3), a functional receptor of CXCL10, is constitutively expressed in male germ cells. Neutralizing antibodies against CXCR3 and an inhibitor of caspase-3 activation significantly inhibited CXCL10-induced male germ cell apoptosis. Furthermore, the tumor necrosis factor-α (TNF-α) upregulated CXCL10 production in Sertoli cells after MuV infection. The knockout of either CXCL10 or TNF-α reduced germ cell apoptosis in the co-cultures of germ cells and Sertoli cells in response to MuV infection. Local injection of MuV into the testes of mice confirmed the involvement of CXCL10 in germ cell apoptosis in vivo. These results provide novel insights into MuV-induced germ cell apoptosis in the testis.

Influence of TNF-alpha inhibitors and fumaric acid esters on male fertility in psoriasis patients

OBJECTIVE

Is there any influence of a therapy with TNF-alpha inhibitors or fumaric acid esters and of disease activity status on male fertility and sperm quality in patients with psoriasis?

METHODS

In this monocentric, open-label, prospective study, semen samples were collected from patients receiving either TNF-alpha inhibitors or fumaric acid esters for moderate-to-severe plaque psoriasis. Semen was analysed at baseline before onset of the systemic therapy and monitored every 3 months under therapy. Sperm parameters were assessed according to the current WHO definitions.

RESULTS

In total, 101 semen specimens from 27 patients were obtained. Mean Psoriasis Area and Severity Index (PASI) score at baseline was 11.05. Only 14.8% of patients showed a normozoospermia without any other abnormal seminal values. 85.2% of patients had at least one sperm/seminal abnormality, including two patients showing an azoospermia. Interestingly, 48.1% showed sperm parameters indicative of genital tract inflammation. Therapy with TNF-alpha inhibitors or fumaric acid esters did not have any negative effects on relevant sperm parameters such as mean total sperm number, sperm concentration, total and progressive motility. No major gonadal dysfunction was observed in any patient.

CONCLUSION

At baseline, many patients with psoriasis showed abnormal semen/sperm parameters and remarkably elevated leukocytes and values of seminal polymorphonuclear elastase, indicating a genital tract inflammation. Thus, genital tract inflammation may represent an important comorbidity of psoriasis, little attention paid to so far. Regarding treatment with TNF-alpha inhibitors or fumaric acid esters, no major negative (side-) effects on sperm quality were observed.

Perspective in Pediatric Pathology, Chapter 24. Testicular Inflammatory Processes in Pediatric Patients

Acute scrotal pain in children represents a major diagnostic and therapeutic challenge. An important initial differentiation should be made between epididymitis and other processes that cause acute scrotal pain, such as testicular torsion and tumor. Infectious agents disseminating through the blood flow can damage the testis by causing orchitis. On the other hand, infections ascending via spermatic pathways typically lead to epididymitis [ 1 ].

Local Actions of Melatonin in Somatic Cells of the Testis

The pineal hormone melatonin regulates testicular function through the hypothalamic-adenohypophyseal axis. In addition, direct actions of melatonin in somatic cells of the testis have been described. Melatonin acts as a local modulator of the endocrine activity in Leydig cells. In Sertoli cells, melatonin influences cellular growth, proliferation, energy metabolism and the oxidation state, and consequently may regulate spermatogenesis. These data pinpoint melatonin as a key player in the regulation of testicular physiology (i.e., steroidogenesis, spermatogenesis) mostly in seasonal breeders. In patients with idiopathic infertility, melatonin exerts anti-proliferative and anti-inflammatory effects on testicular macrophages, and provides protective effects against oxidative stress in testicular mast cells. Consequently, melatonin is also involved in the modulation of inflammatory and oxidant/anti-oxidant states in testicular pathology. Overall, the literature data indicate that melatonin has important effects on testicular function and male reproduction.

Testicular activin and follistatin levels are elevated during the course of experimental autoimmune epididymo-orchitis in mice

Experimental autoimmune epididymo-orchitis (EAEO) is a model of chronic inflammation, induced by immunisation with testicular antigens, which reproduces the pathology of some types of human infertility. Activins A and B regulate spermatogenesis and steroidogenesis, but are also pro-inflammatory, pro-fibrotic cytokines. Expression of the activins and their endogenous antagonists, inhibin and follistatin, was examined in murine EAEO. Adult untreated and adjuvant-treated control mice showed no pathology. All mice immunised with testis antigens developed EAEO by 50 days, characterised by loss of germ cells, immune cell infiltration and fibrosis in the testis, similar to biopsies from human inflamed testis. An increase of total CD45+ leukocytes, comprising CD3+ T cells, CD4 + CD8− and CD4 + CD25+ T cells, and a novel population of CD4 + CD8+ double positive T cells was also detected in EAEO testes. This was accompanied by increased expression of TNF, MCP-1 and IL-10. Activin A and B and follistatin protein levels were elevated in EAEO testes, with peak activin expression during the active phase of the disease, whereas mRNA expression of the inhibin B subunits (Inha and Inhbb) and activin receptor subunits (Acvr1b and Acvr2b) were downregulated. These data suggest that activin–follistatin regulation may play a role during the development of EAEO.

Mouse Testicular Cell Type-Specific Antiviral Response against Mumps Virus Replication

Mumps virus (MuV) infection has high tropism to the testis and usually leads to orchitis, an etiological factor in male infertility. However, MuV replication in testicular cells and the cellular antiviral responses against MuV are not fully understood. The present study showed that MuV infected the majority of testicular cells, including Leydig cells (LC), testicular macrophages, Sertoli cells (SC), and male germ cells (GC). MuV was replicated at relatively high efficiencies in SC compared with LC and testicular macrophages. In contrast, MuV did not replicate in male GC. Notably, testicular cells exhibited different innate antiviral responses against MuV replication. We showed that interferon β (IFN-β) inhibited MuV replication in LC, macrophages, and SC, which were associated with the upregulation of major antiviral proteins. We provided primary evidence that autophagy plays a role in blocking MuV replication in male GC. Autophagy was also involved in limiting MuV replication in testicular macrophages but not in Leydig and SC. These findings indicate the involvement of the innate defense against MuV replication in testicular cells.

Microcystin-Leucine Arginine Causes Cytotoxic Effects in Sertoli Cells Resulting in Reproductive Dysfunction in Male Mice

Microcystin-leucine arginine (MC-LR) is a potent toxin for Sertoli cells. However, the specific molecular mechanisms of MC-induced cytotoxicity still remain unclear. In this study, we performed a comprehensive analyses of changes of miRNAs and mRNAs in Sertoli cells treated with MC-LR. Through computational approaches, we showed the pivotal roles of differentially expressed miRNAs that were associated with cell metabolism, cellular growth and proliferation, cell-to-cell signaling and interaction and cellular movement. Ingenuity Pathway Analyses (IPA) revealed some differentially expressed miRNAs and mRNAs that may cause reproductive system diseases. Target gene analyses suggested that destruction in tight junctions (TJ) and adherens junctions (AJ) in testes may be mediated by miRNAs. Consistent with a significant enrichment of chemokine signaling pathways, we observed numerous macrophages in the testes of mice following treatment with MC-LR, which may cause testicular inflammation. Moreover, miR-98-5p and miR-758 were predicted to bind the 3′-UTR region of the mitogen-activated protein kinase 11 (MAPK11, p38 β isoform) gene which stimulates tumor necrosis factor-α (TNF-α) expression in Sertoli cells. TNF-α could interact with the tumor necrosis factor receptor 1 (TNFR1) on germ cells leading to induction of germ cell apoptosis. Collectively, our integrated miRNA/mRNA analyses provided a molecular paradigm, which was experimentally validated, for understanding MC-LR-induced cytotoxicity.

Specific autoantigens identified by sera obtained from mice that are immunized with testicular germ cells alone

There are various autoimmunogenic antigens (AIs) in testicular germ cells (TGCs) recognized as foreign by the body's immune system. However, there is little information of TGC-specific AIs being available. The aim of this study is to identify TGC-specific AIs. We have previously established that immunization using viable syngeneic TGC can also induce murine experimental autoimmune orchitis (EAO) without using any adjuvant. This study is to identify TGC-specific AIs by TGC liquid chromatography-tandem mass spectrometry analysis, followed by two-dimensional gel electrophoresis that reacted with serum IgG from EAO mice. In this study, we identified 11 TGC-specific AIs that reacted with serum from EAO mice. Real-time RT-PCR analysis showed that the mRNA expressions of seven TGC-specific AIs were significantly higher in only mature testis compared to other organs. Moreover, the recombinant proteins of identified 10 (except unnamed protein) TGC-specific AIs were created by using human embryonic kidney 293 (HEK293) cells and these antigencities were reconfirmed by Western blot using EAO serum reaction. These results indicated Atp6v1a, Hsc70t, Fbp1 and Dazap1 were candidates for TGC-specific AIs. Identification of these AIs will facilitate new approaches for understanding infertility and cancer pathogenesis and may provide a basis for the development of novel therapies.

The presence of macrophages and inflammatory responses in an in vitro testicular co-culture model of male reproductive development enhance relevance to in vivo conditions

Our 3-dimensional testis co-culture system (3D-TCS) represents a promising model of male reproductive toxicity which captures sensitive processes of male reproductive development and contains the main testes cell types (germ, Leydig and Sertoli cells). Macrophages are another cell type important for testicular function and help to modulate immuno-endocrine processes during testes development. Chemicals such as phthalate esters (PE's) affect macrophage function and testosterone production in the testes in vivo. The aim of this study was to determine whether macrophages were present in the 3D-TCS and investigate responses in our model that may be related to immuno-endocrine functions. We observed consistent expression of the resident macrophage marker ED2 as well as increases in inflammatory cytokines produced by macrophages and testes cells (IL-6, TNF-α and KC/GRO) after exposure to toxic PE's. Pathway analysis of gene expression changes after exposure to PE's showed that IL-6 and TNF-α signaling pathways were enriched after treatment with reproductively toxic, but not non-reproductively toxic phthalates. These results indicate that macrophages and inflammatory processes are captured in the 3D-TCS and that these processes are impacted by exposure to reproductive toxicants. These processes represent a major mode of action for in vivo testis toxicity for a variety of compounds and our novel in vitro model is able to capture toxicant perturbation of immune function.

Mumps virus-induced innate immune responses in mouse Sertoli and Leydig cells

Mumps virus (MuV) infection frequently causes orchitis and impairs male fertility. However, the mechanisms underlying the innate immune responses to MuV infection in the testis have yet to be investigated. This study showed that MuV induced innate immune responses in mouse Sertoli and Leydig cells through TLR2 and retinoic acid-inducible gene I (RIG-I) signaling, which result in the production of proinflammatory cytokines and chemokines, including TNF-α, IL-6, MCP-1, CXCL10, and type 1 interferons (IFN-α and IFN-β). By contrast, MuV did not induce the cytokine production in male germ cells. In response to MuV infection, Sertoli cells produced higher levels of proinflammatory cytokines and chemokines but lower levels of type 1 IFNs than Leydig cells did. The MuV-induced cytokine production by Sertoli and Leydig cells was significantly reduced by the knockout of TLR2 or the knockdown of RIG-I signaling. The local injection of MuV into the testis triggered the testicular innate immune responses in vivo. Moreover, MuV infection suppressed testosterone synthesis by Leydig cells. This is the first study examining the innate immune responses to MuV infection in testicular cells. The results provide novel insights into the mechanisms underlying the MuV-induced innate immune responses in the testis.

Inhibition of NOS-NO System Prevents Autoimmune Orchitis Development in Rats: Relevance of NO Released by Testicular Macrophages in Germ Cell Apoptosis and Testosterone Secretion

Background

Although the testis is considered an immunoprivileged organ it can orchestrate immune responses against pathological insults such as infection and trauma. Experimental autoimmune orchitis (EAO) is a model of chronic inflammation whose main histopathological features it shares with human orchitis. In EAO an increased number of macrophages infiltrate the interstitium concomitantly with progressive germ cell degeneration and impaired steroidogenesis. Up-regulation of nitric oxide (NO)-NO synthase (NOS) system occurs, macrophages being the main producers of NO.

Objective

The aim of our study was to evaluate the role of NO-NOS system in orchitis development and determine the involvement of NO released by testicular macrophages on germ cell apoptosis and testosterone secretion.

Method and Results

EAO was induced in rats by immunization with testicular homogenate and adjuvants (E group) and a group of untreated normal rats (N) was also studied. Blockage of NOS by i.p. injection of E rats with a competitive inhibitor of NOS, L-NAME (8mg/kg), significantly reduced the incidence and severity of orchitis and lowered testicular nitrite content. L-NAME reduced germ cell apoptosis and restored intratesticular testosterone levels, without variations in serum LH. Co-culture of N testicular fragments with testicular macrophages obtained from EAO rats significantly increased germ cell apoptosis and testosterone secretion, whereas addition of L-NAME lowered both effects and reduced nitrite content. Incubation of testicular fragments from N rats with a NO donor DETA-NOnoate (DETA-NO) induced germ cell apoptosis through external and internal apoptotic pathways, an effect prevented by N-acetyl-L-cysteine (NAC). DETA-NO inhibited testosterone released from Leydig cells, whereas NAC (from 2.5 to 15 mM) did not prevent this effect.

Conclusions

We demonstrated that NO-NOS system is involved in the impairment of testicular function in orchitis. NO secreted mainly by testicular macrophages could promote oxidative stress inducing ST damage and interfering in Leydig cell function.