Apoptosis of testicular germ cells induced by exogenous glucocorticoid in rats

The effect of red blood cell disorders on male fertility and reproductive health

Male infertility is defined as a failure to conceive after 12 months of unprotected intercourse owing to suspected male reproductive factors. Non-malignant red blood cell disorders are systemic conditions that have been associated with male infertility with varying severity and strength of evidence. Hereditary haemoglobinopathies and bone marrow failure syndromes have been associated with hypothalamic-pituitary-gonadal axis dysfunction, hypogonadism, and abnormal sperm parameters. Bone marrow transplantation is a potential cure for these conditions, but exposes patients to potentially gonadotoxic chemotherapy and/or radiation that could further impair fertility. Iron imbalance might also reduce male fertility. Thus, disorders of hereditary iron overload can cause iron deposition in tissues that might result in hypogonadism and impaired spermatogenesis, whereas severe iron deficiency can propagate anaemias that decrease gonadotropin release and sperm counts. Reproductive urologists should be included in the comprehensive care of patients with red blood cell disorders, especially when gonadotoxic treatments are being considered, to ensure fertility concerns are appropriately evaluated and managed.

Differential susceptibility of male and female germ cells to glucocorticoid-mediated signaling

While physiologic stress has long been known to impair mammalian reproductive capacity through hormonal dysregulation, mounting evidence now suggests that stress experienced prior to or during gestation may also negatively impact the health of future offspring. Rodent models of gestational physiologic stress can induce neurologic and behavioral changes that persist for up to three generations, suggesting that stress signals can induce lasting epigenetic changes in the germline. Treatment with glucocorticoid stress hormones is sufficient to recapitulate the transgenerational changes seen in physiologic stress models. These hormones are known to bind and activate the glucocorticoid receptor (GR), a ligand-inducible transcription factor, thus implicating GR-mediated signaling as a potential contributor to the transgenerational inheritance of stress-induced phenotypes. Here, we demonstrate dynamic spatiotemporal regulation of GR expression in the mouse germline, showing expression in the fetal oocyte as well as the perinatal and adult spermatogonia. Functionally, we find that fetal oocytes are intrinsically buffered against changes in GR signaling, as neither genetic deletion of GR nor GR agonism with dexamethasone altered the transcriptional landscape or the progression of fetal oocytes through meiosis. In contrast, our studies revealed that the male germline is susceptible to glucocorticoid-mediated signaling, specifically by regulating RNA splicing within the spermatogonia, although this does not abrogate fertility. Together, our work suggests a sexually dimorphic function for GR in the germline, and represents an important step towards understanding the mechanisms by which stress can modulate the transmission of genetic information through the germline.

Differential susceptibility of male and female germ cells to glucocorticoid-mediated signaling

While physiologic stress has long been known to impair mammalian reproductive capacity through hormonal dysregulation, mounting evidence now suggests that stress experienced prior to or during gestation may also negatively impact the health of future offspring. Rodent models of gestational physiologic stress can induce neurologic and behavioral changes that persist for up to three generations, suggesting that stress signals can induce lasting epigenetic changes in the germline. Treatment with glucocorticoid stress hormones is sufficient to recapitulate the transgenerational changes seen in physiologic stress models. These hormones are known to bind and activate the glucocorticoid receptor (GR), a ligand-inducible transcription factor, thus implicating GR-mediated signaling as a potential contributor to the transgenerational inheritance of stress-induced phenotypes. Here we demonstrate dynamic spatiotemporal regulation of GR expression in the mouse germline, showing expression in the fetal oocyte as well as the perinatal and adult spermatogonia. Functionally, we find that fetal oocytes are intrinsically buffered against changes in GR signaling, as neither genetic deletion of GR nor GR agonism with dexamethasone altered the transcriptional landscape or the progression of fetal oocytes through meiosis. In contrast, our studies revealed that the male germline is susceptible to glucocorticoid-mediated signaling, specifically by regulating RNA splicing within the spermatogonia, although this does not abrogate fertility. Together, our work suggests a sexually dimorphic function for GR in the germline, and represents an important step towards understanding the mechanisms by which stress can modulate the transmission of genetic information through the germline.

Effects of pharmacological doses of niacin on subacute glucocorticoid-induced testicular damage in rats

Glucocorticoid excess adversely affects male reproduction. This study evaluates effects of pharmacological doses of niacin on testicular structure and function in dexamethasone-treated rats. Adult rats (48) were randomly assigned to 6 equal groups: (1) Negative control (NC): normal rats; (2) Positive control (PC): dexamethasone at 7 mg/kg/day by intraperitoneal injections for 7 days; groups 3-6 (N50, N100, N200, and N400): dexamethasone and concomitant treatment with niacin at 50, 100, 200, and 400 mg/kg/day by oral gavages. Testicular weight and volume of PC rats were significantly lower than the NC group (p < .05). Testicular volume of rats in the N50 and N200 groups was statistically similar to the NC group. Significant decreases in serum testosterone with a slight LH increase were detected in the PC group. Nacin at 50 mg/kg reversed serum testosterone to NC levels and increased serum LH concentration. Niacin only slightly increased epididymal spermatozoa number while all groups of niacin-treated rats had significantly higher percentages of motile spermatozoa compared with the PC group. Hypospermatogenesis, germ cell degeneration and depletion, epithelial vacuolization, and degenerated Leydig cells were observed in PC rats. Lesions were relatively milder in niacin-treated rats. Johnsen scores were also significantly higher in niacin-treated rats. Niacin reduced apoptosis as shown by TUNEL assay. In conclusion, niacin administration at pharmacological doses dose-dependently ameliorates the destructive effects of dexamethasone on sperm motility, Johnsen score, and testicular cell apoptosis in rats with the latter can be considered a decisive mechanism for its positive effects on testis.

Stress-related testicular changes in Wistar and Sprague-Dawley rats following oral administration of an interleukin-8 inhibitor

We describe testicular changes in Wistar and Sprague-Dawley rats following oral administration of DF2156A, a novel allosteric inhibitor of the CXCR1/CXCR2 receptors of interleukin-8. These testicular changes, which were associated with clinical signs, modifications of body weight parameters (decrease of body weight and weight gain) and a decrease of testosterone serum levels, were not considered to be a direct toxic effect of the test substance but secondary to a likely induced stress resulting from the oral administration of a high dose (200 mg/kg/day) of the test substance to male rats for a period of six weeks. Testicular changes consisted of seminiferous tubules atrophy and germinal cell degeneration and only occurred in animals presenting clinical signs of transient visible weight loss, ruffled fur and/or weakened condition, and/or decreased body weight and weight gain. A decrease in serum testosterone levels was only observed in those Sprague-Dawley rats affected by decreased body weight, weight gain and testicular changes. Only a single Wistar rat with testicular changes exhibited relevant reduced levels of circulating testosterone. Sperm analysis in terms of motility, morphology and number of sperm cells was altered in males presenting with morphological changes in the testes. Sprague-Dawley rats with testicular changes were more numerous and with more pronounced lesions than were Wistar rats.

Involvement of GLCCI1 in mouse spermatogenesis

Spermatid production is a complex regulatory process in which coordination between hormonal control and apoptosis plays a pivotal role in maintaining a balanced number of sperm cells. Apoptosis in spermatogenesis is controlled by pro-apoptotic and anti-apoptotic molecules. Hormones involved in the apoptotic process during spermatogenesis include gonadotrophins, sex hormones, and glucocorticoid (GC). GC acts broadly as an apoptosis inducer by binding to its receptor (glucocorticoid receptor: GR) during organ development processes, such as spermatogenesis. However, the downstream pathway induced in GC-GR signaling and the apoptotic process during spermatogenesis remains poorly understood. We reported previously that GC induces full-length glucocorticoid-induced transcript 1 (GLCCI1-long), which functions as an anti-apoptotic mediator in thymic T cell development. Here, we demonstrate that mature murine testis expresses a novel isoform of GLCCI1 protein (GLCCI1-short) in addition to GLCCI1-long. We demonstrate that GLCCI1-long is expressed in spermatocytes along with GR. In contrast, GLCCI1-short is primarily expressed in spermatids where GR is absent; instead, the estrogen receptor is expressed. GLCCI1-short also binds to LC8, which is a known mediator of the anti-apoptotic effect of GLCCI1-long. A luciferase reporter assay revealed that β-estradiol treatment synergistically increased Glcci1-short promotor-driven luciferase activity in Erα-overexpressing cells. Together with the evidence that the conversion of testosterone to estrogen is preceded by aromatase expression in spermatids, we hypothesize that estrogen induces GLCCI1-short, which, in turn, may function as a novel anti-apoptotic mediator in mature murine testis.

Hair cortisol, glucocorticoid gene receptor polymorphisms, stress, and testicular function

OBJECTIVE

Self-reported psychological stress has been associated with decreased semen quality. Cortisol levels in scalp hair (hair cortisol concentration, HCC) has emerged as a potential objective marker of psychological stress. Thus, we investigated if HCC was associated with markers of testicular function. Furthermore, we examined whether three common single nucleotide polymorphisms in the glucocorticoid-receptor gene (NR3C1, chromosome 5), potentially affecting receptor sensitivity, were associated with HCC and could influence the studied association between HCC and testicular function.

DESIGN

Cross-sectional study.

METHODS

We analysed HCC, serum-levels of reproductive hormones, semen parameters, and the three NR3C1-polymorphisms; BclI (rs41423247), Tth111I (rs10052957), and 9β (rs6198), in a population of 696 men from the general population.

RESULTS

HCC was not associated with testicular function, and adjustment for the three NR3C1-polymorphisms did not alter the results. However, HCC increased significantly with the number of Tth111I minor-alleles (T) and decreased significantly with the number of 9β minor-alleles (G).

CONCLUSION

Given previously shown associations between stress and semen quality, and that no association between HCC and self-reported stress was observed in the current study, we speculate that negative reproductive effects of stress may not be mediated directly by cortisol. This study demonstrates associations between HCC and glucocorticoid receptor gene variants indicating that these SNPs may influence systemic glucocorticoid levels, but the potential health effects of such alterations are yet unknown.

Effect of Stress and Caffeine on Male Infertility

Caffeine is a natural psychoactive chemical found in beverages made from coffee. In addition, it is added by the manufacturers of a large number of sodas and energy drinks. It does this by stimulating both the brain and the central nervous system, enabling you to avoid being sleepy while still keeping you attentive. A state of emotional or physical tension is defined as stress. It can be induced through the experience of something or thinking of something that causes you to feel uncomfortable, irritated, or nervous. Your body's response to adversity or demand is what we call stress. Among couples, male infertility is common. A failure in spermatogenesis is accountable for nearly half of all occurrences of infertility in marriage. Ageing, psychological stress, diet, physical exercise, coffee, hot water, hot scrotum, and cell phone usage are some of the few modifiable lifestyle variables that have a role in the development of infertility. Many hypotheses have been proposed to establish the link between stress in the workplace, life events (war, earthquake, etc.), and inability to conceive have been linked to inferior or degraded semen quality. In this review, we will discuss the effect on male fertility of elements including quality of life (such as exercise, diet, and other alterations to one's daily routine) and psychological stress. In addition, the effects on male fertility of elevated scrotal temperature, improper dietary habits, and physical inactivity will be discussed. The loss in male fertility, mainly due to ageing, inappropriate lifestyles, and environmental factors, is a significant public health concern in this century. Couples can enhance their quality of life and increase their chances of naturally conceiving a child by altering their way of life and supplementing it with nutraceutical antioxidants and an organised educational, environmental, dietary, and physical exercise program.

Comparative transcriptomic analysis reveals reproductive impairments caused by PCBs and OH-PCBs through the dysregulation of ER and AR signaling

Reports have highlighted the presence of PCBs and their metabolites, OH-PCBs, in human serum as well as their endocrine-disrupting effects on reproductive function through direct interactions with the androgen receptor (AR) and estrogen receptor (ER). However, the molecular mechanisms directly linking the actions of PCBs and OH-PCBs on the AR and ER to induce reproductive impairment remain poorly understood. In this study, we characterized the cellular response to PCBs and OH-PCBs acting on AR and ER transactivation at the transcriptome level coupled with bioinformatics analysis to identify the downstream pathways of androgen and estrogen signaling that leads to reproductive dysfunction. We first confirmed the agonistic and antagonistic effects of several PCBs and OH-PCBs on AR- and ER-mediated reporter gene activity using the androgen-responsive LNCaP and estrogen-responsive MCF-7 cell lines, respectively. Anti-estrogenic activity was not detected among the tested compounds; however, we found that in addition to anti-androgenic and estrogenic activity, PCB 28 and PCB 138 exhibited androgenic activity, while most of the tested OH-PCBs showed a synergistic effect on DHT-mediated transactivation of the AR. Bioinformatics analysis of transcriptome profiles from selected PCBs and OH-PCBs revealed various pathways that were dysregulated depending on their agonistic, antagonistic, or synergistic effects. The OH-PCBs with estrogenic activity affected pathways including vitamin metabolism and calcium transport. Other notable dysregulated pathways include cholesterol transport in response to androgenic PCBs, thyroid hormone metabolism in response to anti-androgenic PCBs, and antioxidant pathways in response to androgen-synergistic OH-PCBs. Our results demonstrate that PCBs and OH-PCBs directly alter specific pathways through androgen- or estrogen-mediated signaling, thereby providing additional insights into the mechanisms by which these compounds cause reproductive dysfunction.

Male subfertility effects of sub-chronic ethanol exposure during stress in a rat model

BACKGROUND

Stressful conditions increase alcohol consumption in men. Clinical studies link disruption of the neuroendocrine stress system with alcoholism, but the effect of alcohol in a stress condition on male fertility is still relatively poorly understood. This project was undertaken to evaluate the effect of sub-chronic alcohol in a stress condition on male fertility in a rat model.

METHODS

Male Sprague-Dawley rats were randomly divided into a control group, a stress group that was exposed to restraint stress, an ethanol group that was injected with ethanol daily, and a stress + ethanol group that was injected with ethanol daily and was exposed to restraint stress, simultaneously. Furthermore, testis tissue was evaluated histomorphometrically and immunohistochemically for apoptosis using a TUNEL assay after 12 days. Epididymis sperm analysis was done. Blood cortisol and testosterone were measured and expression of hypothalamic kisspeptin (Kiss1), RFRP-3, and MC4R mRNA were evaluated.

RESULTS

Ethanol exposure during restraint stress did not alter body weight. Ethanol exposure decreased the cellular diameter and area, and stress increased the cellular diameter and area, in comparison with the control group. In the stress group, in comparison with the other groups, the number of seminiferous tubules decreased and the numerical density of seminiferous tubules increased. In addition, ethanol exposure and/or stress reduced semen analysis parameters (sperm viability and motility), but did not change serum testosterone concentrations. Apoptosis increased in spermatogonia with ethanol exposure, but spermatocytes were not affected. Our data present the novel finding that ethanol and stress reduced hypothalamic Kiss1 mRNA expression, while ethanol exposure decreased hypothalamic RFRP-3 and MC4R mRNA expression.

CONCLUSIONS

Ethanol decreased cortisol hormone level during the restraint stress condition and attenuated hypothalamic reproductive-related gene expressions. Therefore, ethanol exposure may induce reduction of sperm viability, increased sperm mortality, and increased apoptosis, with long-term effects, and may induce permanent male subfertility.

Dysfunction in Sertoli cells participates in glucocorticoid-induced impairment of spermatogenesis

The effect of stress on male fertility is a widespread public health issue, but less is known about the related signaling pathway. To investigate this, we established a hypercortisolism mouse model by supplementing the drinking water with corticosterone for four weeks. In the hypercortisolism mice, the serum corticosterone was much higher than in the control, and serum testosterone was significantly decreased. Moreover, corticosterone treatment induced decrease of sperm counts and increase of teratozoospermia. Increased numbers of multinucleated giant cells and apoptotic germ cells as well as downregulated meiotic markers suggested that corticosterone induced impaired spermatogenesis. Further, upregulation of macrophage-specific marker antigen F4/80 as well as inflammation-related genes suggested that corticosterone induced inflammation in the testis. Lactate content was found to be decreased in the testis and Sertoli cells after corticosterone treatment, and lactate metabolism-related genes were downregulated. In vitro phagocytosis assays showed that the phagocytic activity in corticosterone-treated Sertoli cells was downregulated and accompanied by decreased mitochondrial membrane potential, while pyruvate dehydrogenase kinase-4 inhibitor supplementation restored this process. Taken together, our results demonstrated that dysfunctional phagocytosis capacity and lactate metabolism in Sertoli cells participates in corticosterone-induced impairment of spermatogenesis.

Chronic unpredictable stress disturbs the blood-testis barrier affecting sperm parameters in mice

RESEARCH QUESTION

Does chronic stress affect the key proteins and sperm parameters of the blood-testis barrier (BTB)?

DESIGN

C57Bl/6 mice were divided into two groups: a non-treated control group and a chronic unpredictable stress (CUS) applied group. The stress status of the animals was confirmed with behavioural tests. Histopathologic evaluation was conducted by haematoxylin and eosin staining and electron microscope. Malondialdehyde, corticosterone and testosterone levels were evaluated in peripheral blood. Expression levels of BTB proteins, namely zonula occludens-1 (ZO-1), claudin-11 (CLDN11) and clathrin in Sertoli cells, were assessed by Western blotting and immunofluorescence techniques. Sperm samples were collected from cauda epididymis, and sperm parameters analysed.

RESULTS

The stress model was confirmed by behavioural tests. Histopathological evaluation of the testes demonstrated a mild degeneration in seminiferous tubules. Malondialdehyde (P = 0.008) and corticosterone levels increased (P = 0.004) and testosterone levels decreased (P = 0.005) in the CUS group. Electron microscopic evaluation confirmed the damage in BTB integrity in the CUS group. Western blot analysis showed that ZO-1 and CLDN11 levels were significantly decreased, although clathrin levels were unchanged. Although sperm concentration and total motility rate were not significantly different between the groups, progressive motility (P = 0.03), normal sperm morphology (P = 0.04), chromatin integrity (toluidine blue) (P = 0.002) and the acrosomal reaction rate (P = 0.002) were significantly decreased, and acrosomal abnormality rate was dramatically increased (P = 0.04) in the CUS group.

CONCLUSIONS

In mice, CUS disrupted BTB integrity and impaired sperm parameters. A decrease in ZO-1 and CLDN11 expression levels may be proposed as the causative factor.

Low testicular zinc level, p53 expression and impairment of Sertoli cell phagocytosis of residual bodies in rat subjected to psychological stress

Psychological stress is a known aetiology of infertility. However, the mechanisms translating it to reproductive dysfunction are not fully elucidated. Three experiments were performed on Wistar rats were designed to evaluate Sertoli cell function under stress. In Experiment I, rats were randomised into three groups: saline baseline group given saline, ASEMA baseline group given aqueous extract of Massularia acuminata, zinc baseline group administered zinc orally. In Experiment II, exposure to psychological stress (for 1 hour per day) was layered on Experiment I while Experiment III substituted stress with administration of dexamethasone (DX). Six rats were sacrificed per group per experiment on days 7 and 14 and the right testis was excised and processed for PAS-haematoxylin staining and the left used for Zn determination. Results show significantly lower testicular Zn level as well more intensely immunoexpression of p53 in saline stress and saline DX groups compared with other groups. Also seen are the presence of residual bodies in the seminiferous tubular lumen of saline groups in Experiments II and III suggesting failure of residual bodies to be transported back towards the basement membrane. This study demonstrates that psychological stress impairs the ability of Sertoli cells to recycle residual bodies.

Effects of corticosterone treatment and wound healing on reproductive traits of American bullfrogs

During reproductive season, calling anuran males display high testosterone (T) and episodically high corticosterone (CORT) plasma levels, which are positively associated with higher calling rates and immunocompetence. However, exposure to constant stress stimuli can result in chronically elevated CORT levels, possibly leading to inhibition of reproductive and immune activity. Reproduction and immune responses are energetically expensive, so when an animal is immunologically challenged, a tradeoff might be expressed, with CORT potentially mediating it. Our aim was to test how episodic and chronic CORT treatments, alongside wound healing, would affect reproduction in American bullfrog males (Lithobates catesbeianus). Forty animals were divided in four groups: Episodic CORT (daily transdermic application of CORT), placebo (daily transdermic application of sesame oil), chronic CORT (subcutaneous CORT silastic implants), and sham control (subcutaneous empty silastic implants). One week after treatments began, animals were punctured in the leg with a biopsy needle and the wound was photographed after 45 days to determine wound healing status (WS). Blood samples were collected throughout the experiment to measure CORT and T plasma levels. After animal euthanasia, testes were dissected, fixed, and analyzed histologically to determine spermatogenic activity (germinative cyst [GmC] morphometrics). As expected, the episodic CORT treatment had no effect on T plasma levels or spermatogenic activity. On the other hand, chronic CORT treatment reduced GmC morphometric traits, indicating suppression of reproduction, although T levels were not altered. In addition, animals from sham control and chronic CORT treatments with higher T levels presented higher WS, which indicates an immune-enhancing T effect.

Effect of exogenous glucocorticoids on male hypogonadism

The aim of the present study was to investigate the effects of exogenous glucocorticoids (GCs), a potent cause of male hypogonadism, on the function of the hypothalamic-pituitary-gonadal axis, and to determine their secondary effects in male patients. The present study was a case-controlled study conducted in Basrah, Iraq. Of the 152 participants who met the inclusion criteria, 100 patients used different types of GCs. Of these 100 patients, 57 patients (57%) were current GC users, and 43 patients (43%) were not currently using GCs (had not used GCs in the past 30 days). The control group was comprised of 52 men (34.21%), considered as healthy participants, although 7 men (13.65%) were biochemically diagnosed with hypogonadism. Current GC exposure significantly decreased the total and free testosterone levels, whereas previous GC exposure increased estradiol (E2) levels, with the 31 patients on oral dexamethasone (cumulative dose, 18.9 mg) exhibiting a 7.5-fold increased risk of being diagnosed with hypogonadism. For previous GC users, a significant increase in the E2 level was observed, whereas all other gonadal hormonal levels were within normal reference ranges, including the total and free testosterone levels. The total cumulative dose of equivalent GCs was 240 mg, which resulted in a decrease in total testosterone levels, and subsequent hypogonadism. Oral dexamethasone at a lower total cumulative dose resulted in hypogonadism.

Natural Mating Differentially Triggers Expression of Glucocorticoid Receptor (NR3C1)-Related Genes in the Preovulatory Porcine Female Reproductive Tract

Mating initiates dynamic modifications of gene transcription in the female reproductive tract, preparing the female for fertilization and pregnancy. Glucocorticoid signaling is essential for the homeostasis of mammalian physiological functions. This complex glucocorticoid regulation is mediated through the glucocorticoid receptor, also known as nuclear receptor subfamily 3 group C member 1 (NR3C1/GR) and related genes, like 11β-hydroxysteroid dehydrogenases (HSD11Bs) and the FK506-binding immunophilins, FKBP5 and FKBP4. This study tested the transcriptome changes in NR3C1/GR regulation in response to natural mating and/or cervical deposition of the sperm-peak ejaculate fraction collected using the gloved-hand method (semen or only its seminal plasma), in the preovulatory pig reproductive tract (cervix to infundibulum, 24 h after mating/insemination/infusion treatments). Porcine cDNA microarrays revealed 22 NR3C1-related transcripts, and changes in gene expression were triggered by all treatments, with natural mating showing the largest differences, including NR3C1, FKBP5, FKBP4, hydroxysteroid 11-beta dehydrogenase 1 and 2 (HSD11B1, HSD11B2), and the signal transducer and activator of transcription 5A (STAT5A). Our data suggest that natural mating induces expression changes that might promote a reduction of the cortisol action in the oviductal sperm reservoir. Together with the STAT-mediated downregulation of cytokine immune actions, this reduction may prevent harmful effects by promoting tolerance towards the spermatozoa stored in the oviduct and perhaps elicit spermatozoa activation and detachment after ovulation.

Mechanisms of Stress-Induced Spermatogenesis Impairment in Male Rats Following Unpredictable Chronic Mild Stress (uCMS)

The negative association between psychological stress and male fertility has been known for many years. This study was aimed at (i) identifying spermatogenesis impairment induced by psychological stress in rats and (ii) exploring the role of glucocorticoid receptor (GR) signaling in these adverse effects (if they exist). Male Sprague Dawley rats were exposed to a six-week period of unpredictable chronic mild stress (uCMS) along with cotreatment of GR antagonist RU486 (1 mg/kg/day). Testicular damage was assessed by testicular pathological evaluation, epididymal sperm concentration, serum testosterone levels, testicular apoptotic cell measurements, and cell cycle progression analyses. Rats in the uCMS group had decreased levels of serum testosterone and decreased epididymal sperm concentration. The uCMS-treated rats also had decreased numbers of spermatids and increased levels of apoptotic seminiferous tubules; additionally, cell cycle progression of spermatogonia was arrested at the G₀/G₁ phase. Furthermore, uCMS exposure caused an increase in serum corticosterone level and activated GR signaling in the testes including upregulated GR expression. RU486 treatment suppressed GR signaling and alleviated the damaging effects of stress, resulting in an increased epididymal sperm concentration. Overall, this work demonstrated for the first time that the activation of GR signaling mediates stress-induced spermatogenesis impairment and that this outcome is related to cell apoptosis and cell cycle arrest in germ cells.

Leydig cell genes change their expression and association with polysomes in a stage-specific manner in the adult mouse testis

Spermatogenesis in mammals occurs in a very highly organized manner within the seminiferous epithelium regulated by different cell types in the testis. Testosterone produced by Leydig cells regulates blood-testis barrier formation, meiosis, spermiogenesis, and spermiation. However, it is unknown whether Leydig cell function changes with the different stages of the seminiferous epithelium. This study utilized the WIN 18,446 and retinoic acid (RA) treatment regime combined with the RiboTag mouse methodology to synchronize male germ cell development and allow for the in vivo mapping of the Leydig cell translatome across the different stages of one cycle of the seminiferous epithelium. Using microarrays analysis, we identified 11 Leydig cell-enriched genes that were expressed in stage-specific manner such as the glucocorticoid synthesis and transport genes, Cyp21a1 and Serpina6. In addition, there were nine Leydig cell transcripts that change their association with polysomes in correlation with the different stages of the spermatogenic cycle including Egr1. Interestingly, the signal intensity of EGR1 and CYP21 varied among Leydig cells in the adult asynchronous testis. However, testosterone levels across the different stages of germ cell development did not cycle. These data show, for the first time, that Leydig cell gene expression changes in a stage-specific manner during the cycle of the seminiferous epithelium and indicate that a heterogeneous Leydig cell population exists in the adult mouse testis.

Safety of important dermatological drugs (retinoids, immune suppressants, anti androgens and thalidomide) in reproductively active males with respect to pregnancy outcome: A brief review of literature

Paternally transmitted damage to offspring is recognized as a complex issue. Each parent contributes 23 chromosomes to a child; hence, it is necessary to know the effects of both maternal and paternal pre-and peri-conceptional exposure to drugs on pregnancy outcome. While there are many studies on the effects of maternal drug exposure on pregnancy outcome, literature on paternal exposure is scarce. Of late however, paternal exposure has been receiving increasing attention. We present a brief review on the safety of commonly used drugs in dermatology, focused on retinoids, immune suppressants, anti androgens and thalidomide.

Lifestyle and fertility: the influence of stress and quality of life on male fertility

BACKGROUND

Male infertility is a widespread condition among couples. In about 50% of cases, couple infertility is attributable to the male partner, mainly due to a failure in spermatogenesis. In recent times, the crucial role that modifiable lifestyle factors play in the development of infertility have generated a growing interest in this field of study, i.e. aging, psychological stress, nutrition, physical activity, caffeine, high scrotal temperature, hot water, mobile telephone use. Several studies have investigated associations between semen quality and the presence of lifestyle stressors i.e. occupational, life events (war, earthquake, etc.) or couple infertility; overall, these studies provide evidence that semen quality is impaired by psychological stress. In this review, we will discuss the impact of quality of life (modifiable lifestyle factors) and psychological stress on male fertility. In addition, the role that increased scrotal temperature along with inappropriate nutritional and physical exercise attitudes exert on male fertility will be presented.

CONCLUSION

The decline of male fertility, particularly associated with advancing age, incorrect lifestyles and environmental factors plays an important role on natality, and its consequences on the future on human population makes this an important public health issue in this century. Thus, modification of lifestyle through a structured program of educational, environmental, nutritional/physical exercise and psychological support, combined with the use of nutraceutical antioxidants can prevent infertility and therefore, may help couples to obtain better quality of life and improved possibility to conceive spontaneously or optimize their chances of conception.

The effect of 20-week continuous 60 Hz magnetic field exposure on testicular function in sprague-dawley rats

Accumulating evidence does not yet confirm the effect of power line frequency magnetic field (MF) on human health and fertility. We recently reported that, at continuous 60 Hz MF exposure in mice, the dose given as magnetic flux density (tesla; T) and duration of exposure was related to induce testicular germ cell apoptosis. We aimed to characterize the effect of a 20-week continuous exposure to 60 Hz MF on the motility, morphology, and number of sperm as well as the apoptosis of testicular germ cell in rats. Sprague-Dawley rats were exposed for 20 weeks to 60 Hz MF of 2, 20, or 200 μT for 24 h/day with rats exposed to sham conditions, serving as the control. The exposure to 60 Hz MF of 2 and 20 μT had no effects on testicular in this study. The exposure to 60 Hz MF of 200 μT for 20 weeks induced increases of the apoptotic cells (P < 0.001) in germ cells and decreases of sperm numbers (P < 0.05). However, the MF did not significantly affect the body or testis mass, seminiferous tubule diameter, or the motility or morphology of sperm. This study concluded that exposure to 60 Hz MF of 200 μT can increase testicular germ cell apoptosis, especially spermatogonia, and reduce sperm count. Also compared to previous mice studies, rats are less sensitive than mice to exposure to 60 Hz MF. Bioelectromagnetics. 39:539-546, 2018. © 2018 Wiley Periodicals, Inc.

FDA-approved medications that impair human spermatogenesis

We herein provide an overview of the single-ingredient U.S. Food and Drug Administration (FDA)-approved drugs that affect human spermatogenesis, potentially resulting in a negative impact on male fertility. To provide this information, we performed an in-depth search of DailyMed, the official website for FDA-approved drug labels. Not surprisingly, hormone-based agents were found to be the drugs most likely to affect human spermatogenesis. The next category of drugs most likely to have effects on spermatogenesis was the antineoplastic agents. Interestingly, the DailyMed labels indicated that several anti-inflammatory drugs affect spermatogenesis, which is not supported by the peer-reviewed literature. Overall, there were a total of 65 labels for drugs of various classes that showed that they have the potential to affect human sperm production and maturation. We identified several drugs indicated to be spermatotoxic in the drug labels that were not reported in the peer-reviewed literature. However, the details about the effects of these drugs on human spermatogenesis are largely lacking, the mechanisms are often unknown, and the clinical impact of many of the findings is currently unclear. Therefore, additional work is needed at both the basic research level and during clinical trials and post-marketing surveillance to fill the gaps in the current knowledge. The present findings will be of interest to physicians and pharmacists, researchers, and those involved in drug development and health care policy.

Linking Stress and Infertility: A Novel Role for Ghrelin

Infertility affects a remarkable one in four couples in developing countries. Psychological stress is a ubiquitous facet of life, and although stress affects us all at some point, prolonged or unmanageable stress may become harmful for some individuals, negatively impacting on their health, including fertility. For instance, women who struggle to conceive are twice as likely to suffer from emotional distress than fertile women. Assisted reproductive technology treatments place an additional physical, emotional, and financial burden of stress, particularly on women, who are often exposed to invasive techniques associated with treatment. Stress-reduction interventions can reduce negative affect and in some cases to improve in vitro fertilization outcomes. Although it has been well-established that stress negatively affects fertility in animal models, human research remains inconsistent due to individual differences and methodological flaws. Attempts to isolate single causal links between stress and infertility have not yet been successful due to their multifaceted etiologies. In this review, we will discuss the current literature in the field of stress-induced reproductive dysfunction based on animal and human models, and introduce a recently unexplored link between stress and infertility, the gut-derived hormone, ghrelin. We also present evidence from recent seminal studies demonstrating that ghrelin has a principal role in the stress response and reward processing, as well as in regulating reproductive function, and that these roles are tightly interlinked. Collectively, these data support the hypothesis that stress may negatively impact upon fertility at least in part by stimulating a dysregulation in ghrelin signaling.

Melatonin ameliorates restraint stress-induced oxidative stress and apoptosis in testicular cells via NF-κB/iNOS and Nrf2/ HO-1 signaling pathway

Decline in semen quality has become a global public health concern. Psychological stress is common in the current modern society and is associated with semen decline. Increasing evidence demonstrated that melatonin has anti-apoptotic and antioxidant functions. Whether melatonin can ameliorate the damage in testes induced by psychological stress has never been investigated. Here, a mouse model of restraint stress demonstrated that melatonin normalized the sperm density decline, testicular cells apoptosis, and testicular oxidative stress in stressed male mice. Melatonin decreased reactive oxygen species (ROS) level, increased superoxide dismutase (SOD) and glutathione (GSH) activities, and downregulated inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) activities in stressed mice testes. Furthermore, melatonin reduced the stress-induced activation of the NF-κB signaling pathway by decreasing the phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) and p65 nuclear translocation. In addition, melatonin upregulated the expression of anti-oxidant proteins including nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Meanwhile, in vitro studies also demonstrated melatonin could reduce oxidative apoptosis of testicular cells. Collectively, melatonin mitigated psychological stress-induced spermatogenic damage, which provides evidence for melatonin as a therapy against sperm impairment associated with psychological stress.

Gradual decrease in spermatogenesis caused by chronic stress

Chronic stress induces decreased sperm motility, viability and concentration in stressed males. Also, stress modifies oxidative status and causes apoptosis in testes, as well as a decrease in the epithelial area of seminiferous tubules. However, there are no studies that analyze the alterations caused by stress in testicular cells. Thus, in this study, alterations in the morphology of testicular germ cells caused by different days of chronic stress were assessed. Adult male rats were exposed to stress by immersion in cold water (ICW) daily for 3, 8, 20 or 50 consecutive days. Plasma testosterone and corticosterone were also assessed. Results showed that chronic stress causes loss of germ cells, and alteration of spermatogenesis. Seminiferous tubules from stressed males showed several degenerative signs, such as vacuoles in the basal epithelium, with picnotic indicia; moderate to severe exfoliation of degenerative germinal cells in the tubule lumen was also observed. These alterations were observed in all days of stress in a gradual way, from day 3-50. Testosterone levels were decreased at all those times, and corticosterone concentrations were increased on the same days. These results show that chronic stress causes severe damage to germ cells, which can account for infertility problems in males. These alterations are related to a decrease in testosterone as well as an increase in corticosterone caused by stress.

Immunosuppressants and Male Reproduction

Prolonged use of immunosuppressant medications is occasionally seen in infertile men with chronic inflammatory conditions; autoimmune disorders; or an organ or hematopoietic stem cell transplant. Chronic inflammation impacts negatively on male reproductive endpoints, so immunosuppressant therapy can produce improvements. Corticosteroids have been used to treat antisperm antibodies and even as an empirical treatment for male infertility in general. Trials of these methods have provided mixed results on semen quality and fertility, with improvement, no change and negative effects reported by different investigators. In a substantial number of observational studies, patients on long-term therapy with prednisone for chronic inflammatory disease, testosterone levels were lower compared to untreated controls, though randomized controlled trials have not been conducted. Similarly decreases in testosterone have been reported in men receiving corticosteroids to minimize transplant rejection; however, most were treated with multiple immunosuppressive medications that may have contributed to this effect. A large number of trials of healthy men treated with corticosteroids have shown some disruption in reproductive hormone levels, but other studies reported no effect. Studies in monkeys, rats (at human equivalent dose), cattle, sheep, and horses have shown endocrine disruption, including low testosterone with dexamethasone treatment. Of the cytostatic immunosuppressives, which have high potential for cellular damage, cyclophosphamide has received the most attention, sometimes lowering sperm counts significantly. Methotrexate may decrease sperm numbers in humans and has significant negative impacts in rodents. Other chemotherapeutic drugs used as immunosuppressants are likely to impact negatively on male fertility endpoints, but few data have been collected. The TNF-α Inhibitors have also received little experimental attention. There is some evidence that the immunophilin modulators: cyclosporine, sirolimus, and everolimus cause endocrine disruption and semen quality impairment. As we review in this chapter, results in experimental species are concerning, and well-designed studies are lacking for the effects of these medications on reproductive endpoints in men.

Prenatally administered dexamethasone impairs folliculogenesis in spiny mouse offspring

This study was designed to determine whether prenatal dexamethasone treatment has an effect on follicular development and atresia in the ovary of spiny mouse (Acomys cahirinus) offspring. Dexamethasone (125µg kg-1 bodyweight per day) was administered to pregnant spiny mice from Day 20 of gestation to parturition. The processes of follicle loss were analysed using classical markers of apoptosis (terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling reaction, active caspase-3) and autophagy (Lamp1). The present study indicated that dexamethasone reduced the pool of healthy primordial follicles. Moreover, the oocytes from these follicles showed intensive caspase-3 and Lamp1 staining. Surprisingly, dexamethasone caused an increase in the number of secondary follicles; however, most of these follicles were characterised by extensive degeneration of the oocyte and caspase-3 and Lamp1 labelling. Western-blot analysis indicated that the glucocorticoid receptor as well as apoptosis and autophagy markers were more strongly expressed in the DEX-treated group than in the control. On the basis of these findings, we have concluded that dexamethasone impairs spiny mouse folliculogenesis and enhances follicular atresia through induction of autophagy or combined autophagy and apoptosis.

Glucocorticoids impair oocyte developmental potential by triggering apoptosis of ovarian cells via activating the Fas system

Previous studies indicate that stress damages oocytes with increased secretion of glucorticoids. However, although injection of female mice with cortisol decreased oocyte competence, exposure of mouse oocytes directly to physiological or stress-induced concentrations of glucorticoids did not affect oocyte maturation and embryo development. This study has explored the mechanisms by which glucocorticoids impair oocyte competence. Female mice were injected with cortisol and the effects of cortisol-injection on oocyte competence, ovarian cell apoptosis and Fas/FasL activation were observed. The results showed that cortisol-injection decreased (a) oocyte developmental potential, (b) the E2/P4 ratio in serum and ovaries, and (c) expression of insulin-like growth factor 1, brain-derived neurotrophic factor and glucocorticoid receptor in mural granulosa cells (MGCs), while increasing levels of (a) cortisol in serum and ovaries, (b) apoptosis in MGCs and cumulus cells (CCs), (c) FasL secretion in ovaries and during oocyte maturation in vitro, and (d) Fas in MGCs, CCs and oocytes. The detrimental effects of cortisol-injection on oocyte competence and apoptosis of MGCs and CCs were significantly relieved when the gld (generalized lymphoproliferative disorder) mice harboring FasL mutations were observed. Together, the results suggested that glucocorticoids impair oocyte competence by triggering apoptosis of ovarian cells via activating the Fas system.

Association of NR3C1/Glucocorticoid Receptor gene SNP with azoospermia in Japanese men

AIM

The molecular pathogenesis of non-obstructive azoospermia (NOA) is unclear. Our aim was to identify the genetic susceptibility for NOA in Japanese men by using a combination of transcriptome network analysis and SNP genotyping.

MATERIAL AND METHODS

We searched for candidate genes using RNA transcriptome network analysis of 2611 NOA-related genes that we had previously reported. We analyzed candidate genes for disease linkage with single nucleotide polymorphisms (SNP) in the genomes of 335 Japanese men with NOA and 410 healthy controls using SNP-specific real-time polymerase chain reaction TaqMan assays.

RESULTS

Three candidate genes (NR3C1, YBX2, and BCL2) were identified by the transcriptome network analysis, each with three SNP. Allele frequency analysis of the nine SNP indicated a significantly higher frequency of the NR3C1 rs852977 G allele in NOA cases compared with controls (corrected P = 5.7e-15; odds ratio = 3.20; 95% confidence interval, 2.40-4.26). The other eight candidate polymorphisms showed no significant association.

CONCLUSION

The NR3C1 rs852977 polymorphism is a potential marker for genetic susceptibility to NOA in Japanese men. Further studies are necessary to clarify the association between the NR3C1 polymorphism and alterations of glucocorticoid signaling pathway leading to male infertility.

Humanin protects against chemotherapy-induced stage-specific male germ cell apoptosis in rats

Humanin (HN) has cytoprotective action on male germ cells after testicular stress induced by heat and hormonal deprivation. To examine whether HN has protective effects on chemotherapy-induced male germ cell apoptosis, we treated four groups of adult rats with (i) vehicle (control), (ii) HN, (iii) cyclophosphamide (CP); or (iv) HN+CP. To investigate whether the protective effects of HN on germ cells require the presence of Leydig cells, another four groups of rats were pre-treated with ethane dimethanesulfonate (EDS), a Leydig cell toxicant, to eliminate Leydig cells. After 3 days, when Leydig cells were depleted by EDS, we administered: (i) vehicle, (ii) HN, (iii) CP; or (iv) HN+CP to rats. All rats were killed 12 h after the injection of HN and/or CP. Germ cell apoptosis was detected by TUNEL assay and quantified by numerical count. Compared with control and HN (alone), CP significantly increased germ cell apoptosis; HN +CP significantly reduced CP-induced apoptosis at early (I-VI) and late stages (IX-XIV) but not at middle stages (VII-VIII) of the seminiferous epithelial cycle. Pre-treatment with EDS markedly suppressed serum and intratesticular testosterone (T) levels, and significantly increased germ cell apoptosis at the middle (VII-VIII) stages. CP did not further increase germ cell apoptosis in the EDS-pre-treated rats. HN significantly attenuated germ cell apoptosis at the middle stages in EDS pre-treated rats. To investigate whether HN has any direct effects on Leydig cell function, adult Leydig cells were isolated and treated with ketoconazole (KTZ) to block testosterone synthesis. HN was not effective in preventing the reduction of T production by KTZ in vitro. We conclude that HN decreases CP and/or EDS-induced germ cell apoptosis in a stage-specific fashion. HN acts directly on germ cells to protect against EDS-induced apoptosis in the absence of Leydig cells and intratesticular testosterone levels are very low.

Glucocorticoid Regulation of Reproduction

It is well accepted that stress, measured by increased glucocorticoid secretion, leads to profound reproductive dysfunction. In times of stress, glucocorticoids activate many parts of the fight or flight response, mobilizing energy and enhancing survival, while inhibiting metabolic processes that are not necessary for survival in the moment. This includes reproduction, an energetically costly procedure that is very finely regulated. In the short term, this is meant to be beneficial, so that the organism does not waste precious energy needed for survival. However, long-term inhibition can lead to persistent reproductive dysfunction, even if no longer stressed. This response is mediated by the increased levels of circulating glucocorticoids, which orchestrate complex inhibition of the entire reproductive axis. Stress and glucocorticoids exhibits both central and peripheral inhibition of the reproductive hormonal axis. While this has long been recognized as an issue, understanding the complex signaling mechanism behind this inhibition remains somewhat of a mystery. What makes this especially difficult is attempting to differentiate the many parts of both of these hormonal axes, and new neuropeptide discoveries in the last decade in the reproductive field have added even more complexity to an already complicated system. Glucocorticoids (GCs) and other hormones within the hypothalamic-pituitary-adrenal (HPA) axis (as well as contributors in the sympathetic system) can modulate the hypothalamic-pituitary-gonadal (HPG) axis at all levels-GCs can inhibit release of GnRH from the hypothalamus, inhibit gonadotropin synthesis and release in the pituitary, and inhibit testosterone synthesis and release from the gonads, while also influencing gametogenesis and sexual behavior. This chapter is not an exhaustive review of all the known literature, however is aimed at giving a brief look at both the central and peripheral effects of glucocorticoids on the reproductive function.

Sexual behavior attenuates the effects of chronic stress in body weight, testes, sexual accessory glands, and plasma testosterone in male rats

The aim of this study was to evaluate whether continuous sexual behavior could attenuate the effects of chronic stress on spermatogenesis, sexual glands, plasma testosterone and corticosterone in sexually experienced male rats. Rats were exposed to stress by immersion in cold water (ICW) daily for 20 or 50 consecutive days. Plasma testosterone and corticosterone, masculine sexual behavior, as well as the number of offspring, the epithelial area of seminiferous, prostatic and seminal glands were assessed. In stressed males, body and testicular weights decreased, male sexual behavior was disrupted, and adrenal weights increased. In males stressed for 50 days, prostate and seminal glands had lower weights compared with controls. Prostate and seminal epithelial areas also decreased in these males. Seminiferous tubules in testes from rats stressed for 20 or 50 days showed several degenerative signs, such as vacuoles in the basal epithelium, with picnotic indicia; moderate to severe exfoliation of degenerative germinal cells in the tubule lumen was also observed. In males stressed for 50 days a significant decrease in seminiferous epithelial area was observed from stages I-VIII, regardless of copulation. The litters from females that copulated with males stressed for 50 days decreased significantly. Chronic stress caused increase in plasma levels of corticosterone, which were higher in males stressed for 20 days than in males stressed for 50 days. Testosterone decreased in stressed males and it was lower in males stressed for 50 days. In stressed males allowed to copulate, body and testicular weights were similar to controls. Adrenal, seminal glands, and prostate weights, as well as epithelial areas of males stressed for 50 days allowed to copulate were also similar to controls. Corticosterone was lower than in males stressed for 50 days, but still higher than in controls. Testosterone in males stressed for 50 days and allowed to copulate was higher than in stressed males not allowed to copulate and control males without copulation, but still lower than in control copulating males. These results show that chronic stress causes germ cell loss in testes and a decrease in prostate and seminal epithelium, possibly as a result of testosterone decrease, affecting fertility. Continuous copulation can attenuate the effects of stress on testosterone levels and on the epithelial area in male sexual glands, but not on the seminiferous epithelium after 50 days of stress.

Extremely low frequency magnetic fields induce spermatogenic germ cell apoptosis: possible mechanism

The energy generated by an extremely low frequency electromagnetic field (ELF-EMF) is too weak to directly induce genotoxicity. However, it is reported that an extremely low frequency magnetic field (ELF-MF) is related to DNA strand breakage and apoptosis. The testes that conduct spermatogenesis through a dynamic cellular process involving meiosis and mitosis seem vulnerable to external stress such as heat, MF exposure, and chemical or physical agents. Nevertheless the results regarding adverse effects of ELF-EMF on human or animal reproductive functions are inconclusive. According to the guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP; 2010) for limiting exposure to time-varying MF (1 Hz to 100 kHz), overall conclusion of epidemiologic studies has not consistently shown an association between human adverse reproductive outcomes and maternal or paternal exposure to low frequency fields. In animal studies there is no compelling evidence of causal relationship between prenatal development and ELF-MF exposure. However there is increasing evidence that EL-EMF exposure is involved with germ cell apoptosis in testes. Biophysical mechanism by which ELF-MF induces germ cell apoptosis has not been established. This review proposes the possible mechanism of germ cell apoptosis in testes induced by ELF-MF.

Impact of adrenalectomy and dexamethasone treatment on testicular morphology and sperm parameters in rats: insights into the adrenal control of male reproduction

Here we investigated the hypothesis that normal levels of glucocorticoids, a class of adrenal steroid hormones, are required for normal testicular and epididymal functions. We examined the effects of the manipulation of glucocorticoid plasma levels by bilateral adrenalectomy (1, 2, 7 and 15 days) alone or in combination with daily treatment with the synthetic glucocorticoid dexamethasone (DEX; 5 μg/kg, i.p., 6 days) on the morphology of the testis and sperm parameters in rats. We showed that adrenalectomy led to a reduction in testicular sperm count and daily sperm production starting 2 days after surgery and a differential decrease in sperm count in the epididymis, according to the region and time post-adrenalectomy analysed. In parallel, testes from 7-day adrenalectomized (ADX) rats displayed a higher frequency of damaged seminiferous tubules and the presence of elongated spermatids retained in the basal epithelial compartment in stages IX-XVII, which is indicative of defective spermiation. The alkaline comet assay revealed a late effect of adrenalectomy on epididymal sperm DNA fragmentation, which was increased only 15 days after surgery. DEX treatment prevented the changes in testicular and epididymal sperm count observed in 7-day ADX rats, but failed to protect the testis from ADX-induced morphological abnormalities. Thus, our results indicated that glucocorticoids may be involved in events related to the maintenance of spermatogenesis and sperm maturation during adulthood. These findings provide new insights into the importance of adrenal steroids to male fertility.

A role for glucocorticoids in stress-impaired reproduction: beyond the hypothalamus and pituitary

In addition to the well-characterized role of the sex steroid receptors in regulating fertility and reproduction, reproductive events are also mediated by the hypothalamic-pituitary-adrenal axis in response to an individual's environment. Glucocorticoid secretion in response to stress contributes to the well-characterized suppression of the hypothalamic-pituitary-gonadal axis through central actions in the hypothalamus and pituitary. However, both animal and in vitro studies indicate that other components of the reproductive system are also regulated by glucocorticoids. Furthermore, in the absence of stress, it appears that homeostatic glucocorticoid signaling plays a significant role in reproduction and fertility in all tissues comprising the hypothalamic-pituitary-gonadal axis. Indeed, as central regulators of the immune response, glucocorticoids are uniquely poised to integrate an individual's infectious, inflammatory, stress, nutritional, and metabolic status through glucocorticoid receptor signaling in target tissues. Endocrine signaling between tissues regulating the immune and stress response and those determining reproductive status provides an evolutionary advantage, facilitating the trade-off between reproductive investment and offspring fitness. This review focuses on the actions of glucocorticoids in tissues important for fertility and reproduction, highlighting recent studies that show glucocorticoid signaling plays a significant role throughout the hypothalamic-pituitary-gonadal axis and characterizing these effects as permissive or inhibitory in terms of facilitating reproductive success.

Protective Effects of Resveratrol against Chronic Immobilization Stress on Testis

Objective. The aim of this study was to investigate protective effects of resveratrol, a strong antioxidant, against possible negative effects of chronic immobilization stress on testes of male rats histochemically, immunohistochemically, ultrastructurally, and biochemically. Material and Methods. Male Wistar rats were divided into 4 groups (n = 7). Group I, control group (C), was not exposed to stress. Group II, stress group (S), was exposed to chronic immobilization stress. In Group III, low dose resveratrol + stress group (LRS), rats were given 10 mg/kg/day resveratrol just before the stress application. In Group IV, high dose resveratrol + stress group (HRS), rats were given 20 mg/kg/day resveratrol just before the stress application. For chronic immobilization stress application animals were put in the plastic tubes (6 cm in diameter, 15 cm in length) during 32 days for 6 hours. All animals were sacrificed 18 hours after the last stress application. Results. Histochemical and ultrastructural investigations showed that in stress group there was germ cell deprivation in seminiferous tubules and increase of connective tissue on interstitial area. No significant changes were seen in low and high dose resveratrol groups. After immunohistochemical investigations, TUNEL (+) and Active Caspase-3 (+) cells were increased in seminiferous tubules of stress group compared with those control group, but they were decreased in low and high dose resveratrol groups. According to biochemically results, MDA, GSH, and testosterone levels in stress group showed no significant difference when compared with those of the other groups. Conclusion. The chronic immobilization stress increases oxidative stress and apoptosis and causes histological tissue damages; resveratrol can minimize the histological damage in testes significantly.

Tissue-specific actions of glucocorticoids on apoptosis: a double-edged sword

First described for their metabolic and immunosuppressive effects, glucocorticoids are widely prescribed in clinical settings of inflammation. However, glucocorticoids are also potent inducers of apoptosis in many cell types and tissues. This review will focus on the established mechanisms of glucocorticoid-induced apoptosis and outline what is known about the apoptotic response in cells and tissues of the body after exposure to glucocorticoids. Glucocorticoid-induced apoptosis affects the skeletal system, muscular system, circulatory system, nervous system, endocrine system, reproductive system, and the immune system. Interestingly, several cell types have an anti-apoptotic response to glucocorticoids that is cytoprotective. Lastly, we will discuss the pro- and anti-apoptotic effects of glucocorticoids in cancers and their clinical implications.

Dexamethasone induces germ cell apoptosis in the human fetal ovary

CONTEXT

The 21-hydroxylase deficiency is the most common cause of congenital adrenal hyperplasia. Pregnant women presenting a risk of genetic transmission may be treated with synthetic glucocorticoids such as dexamethasone (DEX) to prevent female fetus virilization.

OBJECTIVE

The aim of this study was to assess the potential deleterious effects of DEX exposure on fetal ovarian development.

SETTINGS

Human fetal ovaries, ranging from 8-11 weeks after fertilization, were harvested from material available after legally induced abortions. They were cultured in the absence or presence of DEX (2, 10, or 50 μm) over 14 d, and histological analyses were performed.

RESULTS

The glucocorticoid receptor NR3C1 was present and the signaling pathway active in the fetal ovary as demonstrated by the expression of NR3C1 target genes, such as PLZF and FKBP5, in response to DEX exposure. DEX decreased germ cell density at the 10 and 50 μm doses. Exposure to DEX, even at the highest dose, did not change oogonial proliferation as monitored by 5-bromo-2'-deoxyuridine incorporation and significantly increased the apoptotic rate, detected with cleaved caspase 3 staining. Interestingly, the expression of the prosurvival gene KIT was significantly decreased in the presence of DEX during the course of the culture.

CONCLUSION

We have demonstrated for the first time that in vitro exposure to high doses of DEX impairs human fetal oogenesis through an increase in apoptosis. These data are of high importance, and additional epidemiological studies are required to investigate the female fertility of those women who have been exposed to DEX during fetal life.

Thymus as a target tissue of glucocorticoid action: what are the consequences of glucocorticoids thymectomy?

Glucocorticoids represent the most powerful endogenous anti-inflammatory and immunosuppressive effectors, interfering with virtually every step of immunoinflammatory responses. Glucocorticoids are often the most effective therapy in the prevention or suppression of inflammation and other immunologically mediated processes, but their use is limited by systemic side effects induced by the over-production of reactive oxygen species, causing dysregulation of physiological processes. The thymus is an organ with both endocrine and immune functions. Glucocorticoids induce thymocyte apoptosis, causing a profound reduction in thymic mass and volume and inducing hormonal thymectomy. The clinical aspects of glucocorticoid thymectomy are not under enough investigation. These unwanted systemic side effects may be the consequence of prolonged therapeutic application of glucocorticoids and prolonged or chronic activation of the hypothalamic-pituitary adrenal axis, which may lead to increased and prolonged secretion of glucocorticoids. This review will discuss the metabolic effects of glucocorticoids in the context of thymic physiology asthe primary sex hormone-responsive organ.

Effects of 60 Hz 14 microT magnetic field on the apoptosis of testicular germ cell in mice

We recently reported that continuous exposure, for 8 weeks, of extremely low frequency (ELF) magnetic field (MF) of 0.1 or 0.5 mT might induce testicular germ cell apoptosis in BALB/c mice. In that report, the ELF MF exposure did not significantly affect the body weight or testicular weight, but significantly increased the incidence of testicular germ cell death. In the present study, we aimed to further characterize the effect of a 16-week continuous exposure to ELF MF of 14 or 200 microT on testicular germ cell apoptosis in mice. There were no significant effects of MF on body weight and testosterone levels in mice. In TUNEL staining (In situ terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labeling), germ cells showed a significantly higher apoptotic rate in exposed mice than in sham controls (P < 0.001). TUNEL-positive cells were mainly spermatogonia. In an electron microscopic study, degenerating spermatogonia showed condensation of nuclear chromatin similar to apoptosis. These results indicate that apoptosis may be induced in spermatogenic cells in mice by continuous exposure to 60 Hz MF of 14 microT.

Adrenocorticotropic hormone affects nonapoptotic cell death of undifferentiated germ cells in the fetal mouse testis: in vivo study by exo utero transplantation of corticotropic tumor cells into embryos

Adrenocorticotropic hormone (ACTH) has been suggested to have possible roles in the fetal testes, one of the organs that express its specific receptors, melanocortin type 2 and 5 receptors (MC2R and MC5R), during the fetal period. We investigated the effect of ACTH on the cells in the testis cord of the fetal mouse testis by inducing ACTH-secreting AtT20 tumor cells in mouse fetuses. We first identified that mouse testicular germ cells at embryonic day (E) 16.5 and E18.5 spermatogonia were entirely CDH1 (E-cadherin)-positive by immunohistochemistry. We next performed AtT20-cell transplantation into the mouse fetus at E12.5, and analyzed ACTH effects on the development of fetal male mouse germ cells that express MC2R and MC5R at E16.5 and E18.5. The spermatogonia in the testis of AtT20-implanted embryos exhibited morphological changes, including pyknotic nuclei and swollen cytoplasm. In the AtT20-implanted embryos, the number of spermatogonia per unit area of the testis cord was significantly lower, but there were more pyknotic spermatogonia than in the controls. Single-stranded DNA-positive (apoptotic) and histone H3-positive (mitotic) spermatogonia were rarely observed and their numbers did not significantly differ in the two groups. Anti-Müllerian hormone (AMH)-positive Sertoli cells, another cell type that constitutes the fetal testis cord but does not express MC2R or MC5R, showed no apparent morphological changes compared with controls, nor were their numbers in the two groups significantly different between the two groups. These results suggest that ACTH, via MC2R and/or MC5R, may be involved in the nonapoptotic cell death of fetal mouse spermatogonia that is observed during the normal perinatal period.

Effect of dexamethasone on germ cell apoptosis in the contralateral testis after testicular ischemia-reperfusion injury in the rat

OBJECTIVE

To evaluate the effect of dexamethasone on spermatogenesis and germ cell apoptosis in the ipsilateral and contralateral testis after testicular ischemia-reperfusion (IR) in rats.

DESIGN

Laboratory study.

SETTING

Medical research laboratory in a university setting.

ANIMAL(S)

Forty adult Sprague-Dawley rats weighing 250-280 g.

INTERVENTION(S)

Testicular IR, treatment with dexamethasone (10 mg per kilogram of body weight).

MAIN OUTCOME MEASURE(S)

Testicular germ cell apoptosis was assessed by deoxyuridine nick-end labeling immunohistochemical assay.

RESULT(S)

Testicular ischemia in rats led to histological damage in the ipsilateral testis. In the contralateral testis, minimal damage was observed. Germ cell apoptosis in both the ischemic and the contralateral testis increased significantly after IR. Treatment with dexamethasone did not change germ cell apoptosis in ischemic testis but decreased germ cell apoptosis in the contralateral testis.

CONCLUSION(S)

Glucocorticoids may be beneficial for spermatogenesis after testicular IR by decreasing germ cell apoptosis in the contralateral testis.