Androgen receptor roles in spermatogenesis and fertility: lessons from testicular cell-specific androgen receptor knockout mice

New insights into FAK function and regulation during spermatogenesis

Germ cell transport across the seminiferous epithelium during the epithelial cycle is crucial to spermatogenesis, although molecular mechanism(s) that regulate these events remain unknown. Studies have shown that spatiotemporal expression of crucial regulatory proteins during the epithelial cycle represents an efficient and physiologically important mechanism to regulate spermatogenesis without involving de novo synthesis of proteins and/or expression of genes. Herein, we critically review the role of focal adhesion kinase (FAK) in coordinating the transport of spermatids and preleptotene spermatocytes across the epithelium and the BTB, respectively, along the apical ectoplasmic specialization (ES) - blood-testis barrier - basement membrane (BM) functional axis during spermatogenesis. In the testis, p-FAK-Tyr³⁸⁷ and p-FAK-Tyr⁴⁰⁷ are spatiotemporally expressed during the epithelial cycle at the actin-rich anchoring junction known as ES, regulating cell adhesion at the Sertoli-spermatid (apical ES) and Sertoli cell-cell (basal ES) interface. Phosphorylated forms of FAK exert their effects by regulating the homeostasis of F-actin at the ES, mediated via their effects on actin polymerization so that microfilaments are efficiently re-organized, such as from their "bundled" to "de-bundled/branched" configuration and vice versa during the epithelial cycle to facilitate the transport of: (i) spermatids across the epithelium, and (ii) preleptotene spermatocytes across the BTB. In summary, p-FAK-Tyr⁴⁰⁷ and p-FAK-Tyr³⁸⁷ are important regulators of spermatogenesis which serve as molecular switches that turn "on" and "off" adhesion function at the apical ES and the basal ES/BTB, mediated via their spatiotemporal expression during the epithelial cycle. A hypothetical model depicting the role of these two molecular switches is also proposed.

Over-expressed Testis-specific Protein Y-encoded 1 as a novel biomarker for male hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a male-predominant cancer. Previous studies have focused on the sex-related disparity in HCC, but the underlying mechanism remains unclear. Here, we aimed to discover characteristic biomarkers for male HCC. Clinical samples were subjected to iTRAQ labeling followed by 2DLC-ESI-MS/MS analysis. Seventy-three differential proteins containing 16 up-regulated and 57 down-regulated proteins were screened out in the male HCC group compared to that in female HCC group. Testis-specific Protein Y-encoded 1(TSPY1) is characteristically present in male HCC and was chosen for further investigation. The data from the functional effects of TSPY1 indicated that over-expression of TSPY1 could potentiate HCC cell proliferation, increase soft agar colonization, induce higher cell invasive ability and correlate with the metastatic potential of the HCC cell lines. In addition, TSPY1 and androgen receptor (AR) were co-expressed simultaneously in HCC cell lines as well as in HCC tissue. TSPY1 up- or down-regulation could lead to a high or low level expression of AR. These results implied that TSPY1 may be included in the regulation of AR expression involved in male HCC and it may act as a novel biomarker for male HCC.

Two periods of total testicular regression are peculiar events of the annual reproductive cycle of the black Myotis bat, Myotis nigricans (Chiroptera: Vespertilionidae)

Myotis nigricans presents few and controversial reproductive data, which indicate geographical variation in reproduction. Thus, this study aimed to evaluate the seasonal modifications in testicular and epididymal morphologies in a tropical environment, submitting these organs to morphometric and immunohistochemical analysis. The observations revealed that this species presents two peaks of spermatogenic activity followed by two periods of total testicular regression (a quiescent pre-pubertal-like morphology, where only Sertoli cells and spermatogonia could be observed), in the same annual reproductive cycle, which seem to be only indirectly influenced by abiotic factors. This testicular behaviour seems to be synchronised with the caput and corpus epididymidis, but not with the cauda epididymidis, which presents aspects of sperm storage in May–June. The control of this variation seems to be directly linked to the expression of the androgen receptor, since, throughout the year, it is high in periods of testicular recrudescence and low in periods of deactivation. It is not thought to be directly linked to apoptosis, which is more pronounced in periods of recrudescence than in periods of regression.

Status of the down-regulated canine testis using two different GNRH agonist implants in comparison with the juvenile testis

Testicular function in the dog was down-regulated using two different GNRH agonist implants, with adult and juvenile testes serving as controls. Treatment resulted in an increased percentage of the interstitial area and decreased area of Leydig cell nuclei. Expression of StAR and the steroidogenic enzymes cytochrome P450 side-chain cleavage enzyme (P450scc, CYP11A1) and cytochrome P450 17α-hydroxylase-17,20-lyase (P450c17, CYP17A1) in Leydig cells was blocked at the mRNA and protein level, showing no differences between the two agonists. Staining for androgen receptor (AR) by immunohistochemistry was positive in Sertoli, Leydig and peritubular cells and some spermatogonia, with in situ hybridization confirming expression in Sertoli cells. At the mRNA level, expression of AR was not affected; however, translation was blocked (reduced percentage of AR-positive Sertoli cells), with the number of nuclei in basal position being decreased. In the juvenile testes, mRNA expression of StAR, CYP11A1 and CYP17A1 was higher compared with the other groups but distinctly lower for the AR. At the protein level, the expression was at the limit of detection for StAR; AR-positive Sertoli cells were not detected. Our observations show that the down-regulated testis is different from the juvenile one rather resembling the testicular status in seasonal breeders out of season.

Effect of pubertal nano-TiO2 exposure on testosterone synthesis and spermatogenesis in mice

Titanium dioxide nanoparticles (nano-TiO2) are frequently used in cosmetics, paints, sunscreens and the like. Recent studies have demonstrated that nano-TiO2 might be deleterious for the male reproductive function. However, the effects of pubertal nano-TiO2 exposure on testosterone (T) synthesis and spermatogenesis remained to be elucidated. Here, we investigated the effect of pubertal nano-TiO2 exposure on the synthesis of T and spermatogenesis. Nano-TiO2 was orally administered daily to Kunming male mice from 28th postnatal day (PND 28) to PND 70. The percentage of spermatozoa abnormality in epididymides was markedly increased in mice exposed to nano-TiO2; decreased layers of spermatogenic cells and vacuoles in seminiferous tubules were also observed in the nano-TiO2 treated group. In addition, pubertal nano-TiO2 exposure significantly decreased the serum T levels in male mice. Moreover, mice exposures to nano-TiO2 significantly reduced the expression of 17β-hydroxysteroid dehydrogenase and P450 17α-hydroxysteroid dehydrogenase in the testis of mice, while the expression of cytochrome P450-19, a key enzyme for the translation of T to estradiol (E2), was increased. Taken together, these results indicated that nano-TiO2 could influence the levels of serum T through changes in both the synthesis and translation of T. Furthermore, the decreased serum T synthesis might contribute to the reduced spermatogenesis in mice exposed to nano-TiO2.

AR3 messenger ribonucleic acid expression and its functional implication in human primary testicular failure

AR3, a major one of androgen receptor (AR) splice variants, has been shown to play a pivotal role in concert with AR signalling in prostate cancer. The present study was undertaken to characterise the expression pattern of AR3 in normal and impaired spermatogenesis. Expression of AR3 mRNA showed significantly lower level in testicular tissues with impaired spermatogenesis when compared to normal tissues. This aberrant expression profile of AR3 in human pathological testes was further confirmed by immunoblotting analysis. Moreover, in situ hybridisation studies revealed that the transcripts of the gene were dominantly localised in the pachytene spermatocytes and round spermatids, suggesting a potential involvement of this transcriptional regulator in the auto-/paracrine regulation of meiotic and post-meiotic differentiation. This hypothesis was strengthened by the observation that AR3 mRNA expression was positively correlated to average seminiferous tubule score and was negatively correlated to serum FSH level. To the best of our knowledge, such a distinct expression profile of AR3 has not been reported previously in human testis. Overall, our data are suggestive of a novel site of action of AR3 during human spermatogenesis and should shed light on the complicated circuit composed of AR and its splice variants.

Up-regulation of SOX9 in sertoli cells from testiculopathic patients accounts for increasing anti-mullerian hormone expression via impaired androgen receptor signaling

Background

Testosterone provokes Sertoli cell maturation and represses AMH production. In adult patients with Sertoli-cells-only syndrome (SCOS) and androgen insensitivity syndrome (AIS), high level of AMH expression is detected in Sertoli cells due to defect of androgen/AR signaling.

Objective

We postulated that up-regulation of SOX9 due to impairment of androgen/AR signaling in Sertoli cells might explain why high level of anti-Mullerian hormone (AMH) expression occur in these testiculopathic patients.

Methods

Biological research of testicular specimens from men with azoospermia or mouse. The serum hormone levels were studied in 23 men with obstructive azoospermia, 33 men with SCOS azoospermia and 21 volunteers with normal seminograms during a period of 4 years.

Immunohistochemical staining and reverse-transcription PCR were used to examine the relationships among AR, SOX9 and AMH expression in adult human and mouse testes. The ability of AR to repress the expression of SOX9 and AMH was evaluated in vitro in TM4 Sertoli cells and C3H10T1/2 cells.

Results

SCOS specimens showed up-regulation of SOX9 and AMH proteins but down-regulation of AR proteins in Sertoli cells. The mRNA levels of AR were significantly lower and the SOX9, AMH mRNA levels higher in all SCOS patients compared to controls (P< 0.05). The testosterone levels in the SCOS patients were within the normal range, but most were below the median of the controls. Furthermore, our invitro cell line experiments demonstrated that androgen/AR signaling suppressed the gene and protein levels of AMH via repression of SOX9.

Conclusions

Our data show that the functional androgen/AR signaling to repress SOX9 and AMH expression is essential for Sertoli cell maturation. Impairment of androgen/AR signaling promotes SOX9-mediated AMH production, accounts for impairments of Sertoli cells in SCOS azoospermic patients.

Sulfotransferase genes: regulation by nuclear receptors in response to xeno/endo-biotics

Pregnane X receptor (PXR) and constitutive active/androstane receptor (CAR), members of the nuclear receptor superfamily, are two major xeno-sensing transcription factors. They can be activated by a broad range of lipophilic xenobiotics including therapeutics drugs. In addition to xenobiotics, endogenous compounds such as steroid hormones and bile acids can also activate PXR and/or CAR. These nuclear receptors regulate genes that encode enzymes and transporters that metabolize and excrete both xenobiotics and endobiotics. Sulfotransferases (SULTs) are a group of these enzymes and sulfate xenobiotics for detoxification. In general, inactivation by sulfation constitutes the mechanism to maintain homeostasis of endobiotics. Thus, deciphering the molecular mechanism by which PXR and CAR regulate SULT genes is critical for understanding the roles of SULTs in the alterations of physiological and pathophysiological processes caused by drug treatment or environmental exposures.

Sertoli cell androgen receptor expression regulates temporal fetal and adult Leydig cell differentiation, function, and population size

We recently created a mouse model displaying precocious Sertoli cell (SC) and spermatogenic development induced by SC-specific transgenic androgen receptor expression (TgSCAR). Here we reveal that TgSCAR regulates the development, function, and absolute number of Leydig cells (LCs). Total fetal and adult type LC numbers were reduced in postnatal and adult TgSCAR vs control testes, despite normal circulating LH levels. Normal LC to SC ratios found in TgSCAR testes indicate that SC androgen receptor (SCAR)-mediated activity confers a quorum-dependent relationship between total SC and LC numbers. TgSCAR enhanced LC differentiation, shown by elevated ratios of advanced to immature LC types, and reduced LC proliferation in postnatal TgSCAR vs control testes. Postnatal TgSCAR testes displayed up-regulated expression of coupled ligand-receptor transcripts (Amh-Amhr2, Dhh-Ptch1, Pdgfa-Pdgfra) for potential SCAR-stimulated paracrine pathways, which may coordinate LC differentiation. Neonatal TgSCAR testes displayed normal T and dihydrotestosterone levels despite differential changes to steroidogenic gene expression, with down-regulated Star, Cyp11a1, and Cyp17a1 expression contrasting with up-regulated Hsd3b1, Hsd17b3, and Srd5a1 expression. TgSCAR males also displayed elevated postnatal and normal adult serum testosterone levels, despite reduced LC numbers. Enhanced adult-type LC steroidogenic output was revealed by increased pubertal testicular T, dihydrotestosterone, 3α-diol and 3β-diol levels per LC and up-regulated steroidogenic gene (Nr5a1, Lhr, Cyp11a1, Cyp17a1, Hsd3b6, Srd5a1) expression in pubertal or adult TgSCAR vs control males, suggesting regulatory mechanisms maintain androgen levels independently of absolute LC numbers. Our unique gain-of-function TgSCAR model has revealed that SCAR activity controls temporal LC differentiation, steroidogenic function, and population size.

Expression, purification and crystallization of the ancestral androgen receptor-DHT complex

Steroid receptors (SRs) are a closely related family of ligand-dependent nuclear receptors that mediate the transcription of genes critical for development, reproduction and immunity. SR dysregulation has been implicated in cancer, inflammatory diseases and metabolic disorders. SRs bind their cognate hormone ligand with exquisite specificity, offering a unique system to study the evolution of molecular recognition. The SR family evolved from an estrogen-sensitive ancestor and diverged to become sensitive to progestagens, corticoids and, most recently, androgens. To understand the structural mechanisms driving the evolution of androgen responsiveness, the ancestral androgen receptor (ancAR1) was crystallized in complex with 5α-dihydrotestosterone (DHT) and a fragment of the transcriptional mediator/intermediary factor 2 (Tif2). Crystals diffracted to 2.1 Å resolution and the resulting structure will permit a direct comparison with its progestagen-sensitive ancestor, ancestral steroid receptor 2 (AncSR2).

The Wilms tumor gene, Wt1, is critical for mouse spermatogenesis via regulation of sertoli cell polarity and is associated with non-obstructive azoospermia in humans

Azoospermia is one of the major reproductive disorders which cause male infertility in humans; however, the etiology of this disease is largely unknown. In the present study, six missense mutations of WT1 gene were detected in 529 human patients with non-obstructive azoospermia (NOA), indicating a strong association between WT1 mutation and NOA. The Wilms tumor gene, Wt1, is specifically expressed in Sertoli cells (SCs) which support spermatogenesis. To examine the functions of this gene in spermatogenesis, Wt1 was deleted in adult testis using Wt1^flox and Cre-ER^TM mice strains. We found that inactivation of Wt1 resulted in massive germ cell death and only SCs were present in most of the seminiferous tubules which was very similar to NOA in humans. In investigating the potential mechanism for this, histological studies revealed that the blood–testis barrier (BTB) was disrupted in Wt1 deficient testes. In vitro studies demonstrated that Wt1 was essential for cell polarity maintenance in SCs. Further studies found that the expression of cell polarity associated genes (Par6b and E-cadherin) and Wnt signaling genes (Wnt4, Wnt11) were downregulated in Wt1 deficient SCs, and that the expression of Par6b and E-cadherin was regulated by Wnt4. Our findings suggest that Wt1 is important in spermatogenesis by regulating the polarity of SCs via Wnt signaling pathway and that WT1 mutation is one of the genetic causes of NOA in humans.

Infertility is one of the most common health problems, affecting about 15% of the couples in the world. In about half of these couples, infertility is related to male reproductive defect. Azoospermia is one of the major causes of male infertility in humans. Previous studies have found that the mutation or deletion of some genes is associated with azoospermia; however, the genetic cause of this remains largely unknown. In the present study, we detected Wt1 missense mutations in men with non-obstructive azoospermia (NOA). An essential function for WT1 in male spermatogenesis was confirmed by the use of a Wt1 conditional knockout mouse strain. Inactivation of Wt1 resulted in germ cell loss in mice, which was similar to NOA in human patients. Our data indicate that WT1 mutation is one genetic cause of male infertility and suggest that WT1 mutational analysis will be useful for diagnosis in a clinical setting.

Experimental varicocoele in rats affects mechanisms that control expression and function of the androgen receptor

Varicocoele is an important cause of male infertility. Normal male reproductive function and fertility depends on a delicate balance between androgen receptor (AR) and the classic oestrogen receptors ESR1 (ERα) and ESR2 (ERβ). Using a model of surgically induced varicocoele in rats, this study aimed to investigate the effects of varicocoele on the expression of AR, ESR1, ESR2 and G-protein coupled oestrogen receptor (GPER). Varicocoele did not affect the mRNA and protein expression of ESR1 and ESR2 in both testes. Varicocoele did not affect the mRNA and protein expression of GPER in the right testis, but slightly reduced the mRNA and increased the protein levels in the left testis. Varicocoele did not affect the mRNA for AR, but reduced the protein levels in both testes. A proteomic approach was used in an attempt to find differentially expressed targets with possible correlation with AR downregulation. Varicocoele caused the differential expression of 29 proteins. Six proteins were upregulated, including the receptor for activated C kinase 1 (RACK1), and 23 were downregulated, including dihydrolipoamide dehydrogenase, alpha-enolase and pyrophosphatase 1. Western blot analysis confirmed that varicocoele upregulated the expression of RACK1, a protein involved with tyrosine phosphorylation and regulation of AR transcriptional activity, AR metabolism and dynamics of the blood-testis barrier. In conclusion, this study suggests that varicocoele affects mechanisms that control AR expression and function. This regulation of AR may play an important role in the varicocoele-induced testicular dysfunction. Furthermore, varicocoele downregulates several other proteins in the testis that may be useful markers of spermatozoa function and male infertility.

Androgen receptor expression relationship with semen variables in infertile men with varicocele

PURPOSE

Androgen receptor, a member of the nuclear receptor superfamily, has important roles in male reproductive function. It is required for sexual differentiation, pubertal development, spermatogenesis regulation, meiosis completion and spermatocyte transition to haploid round spermatids. We assessed the association of androgen receptor expression and semen variables in infertile men with varicocele.

MATERIALS AND METHODS

A total of 299 men were grouped into healthy, fertile controls, infertile men without varicocele and men with infertility associated with varicocele. A history was obtained, clinical examination and semen analysis were done and reproductive hormones were estimated. Androgen receptor expression and the acrosome reaction were determined in recovered spermatozoa.

RESULTS

Androgen receptor expression was significantly decreased in infertile men with varicocele more than in infertile men without varicocele compared to fertile controls. Androgen receptor correlated positively with sperm count, motility, normal forms, velocity, linear velocity, acrosome reaction and α-glucosidase. It correlated negatively with serum follicle-stimulating hormone and estradiol. Multiple stepwise regression analysis of androgen receptor expression revealed that the sperm acrosome reaction and linearity index were the most affected independent variables.

CONCLUSIONS

Androgen receptor expression was significantly decreased in infertile men with varicocele more than in infertile men without varicocele compared to fertile men. Androgen receptor expression correlated positively with sperm count, motility, normal forms, velocity, linear velocity and acrosome reaction.

Proteomic analysis of human spermatozoa proteins with oxidative stress

BACKGROUND

Oxidative stress plays a key role in the etiology of male infertility. Significant alterations in the sperm proteome are associated with poor semen quality. The aim of the present study was to examine if elevated levels of reactive oxygen species cause an alteration in the proteomic profile of spermatozoa.

METHODS

This prospective study consisted of 52 subjects: 32 infertile men and 20 normal donors. Seminal ejaculates were classified as ROS+ or ROS- and evaluated for their proteomic profile. Samples were pooled and subjected to LC-MS/MS analysis through in-solution digestion of proteins for peptide characterization. The expression profile of proteins present in human spermatozoa was examined using proteomic and bioinformatic analysis to elucidate the regulatory pathways of oxidative stress.

RESULTS

Of the 74 proteins identified, 10 proteins with a 2-fold difference were overexpressed and 5 were underexpressed in the ROS+ group; energy metabolism and regulation, carbohydrate metabolic processes such as gluconeogenesis and glycolysis, protein modifications and oxidative stress regulation were some of the metabolic processes affected in ROS+ group.

CONCLUSIONS

We have identified proteins involved in a variety of functions associated with response and management of oxidative stress. In the present study we focused on proteins that showed a high degree of differential expression and thus, have a greater impact on the fertilizing potential of the spermatozoa. While proteomic analyses identified the potential biomarkers, further studies through Western Blot are necessary to validate the biomarker status of the proteins in pathological conditions.

Breast cancer resistance protein (Bcrp) and the testis--an unexpected turn of events

Breast cancer resistance protein (Bcrp) is an ATP-dependent efflux drug transporter. It has a diverse spectrum of hydrophilic and hydrophobic substrates ranging from anticancer, antiviral and antihypertensive drugs, to organic anions, antibiotics, phytoestrogens (e.g., genistein, daidzein, coumestrol), xenoestrogens and steroids (e.g., dehydroepiandrosterone sulfate). Bcrp is an integral membrane protein in cancer and normal cells within multiple organs (e.g., brain, placenta, intestine and testis) that maintains cellular homeostasis by extruding drugs and harmful substances from the inside of cells. In the brain, Bcrp is a major component of the blood-brain barrier located on endothelial cells near tight junctions (TJs). However, Bcrp is absent at the Sertoli cell blood-testis barrier (BTB); instead, it is localized almost exclusively to the endothelial TJ in microvessels in the interstitium and the peritubular myoid cells in the tunica propria. Recent studies have shown that Bcrp is also expressed stage specifically and spatiotemporally by Sertoli and germ cells in the seminiferous epithelium of rat testes, limited only to a testis-specific cell adhesion ultrastructure known as the apical ectoplasmic specialisation (ES) in stage VI-early VIII tubules. These findings suggest that Bcrp is equipped by late spermatids and Sertoli cells to protect late-stage spermatids completing spermiogenesis. Furthermore, Bcrp was found to be associated with F (filamentous)-actin and several actin regulatory proteins at the apical ES and might be involved in the organisation of actin filaments at the apical ES in stage VII-VIII tubules. These findings will be carefully evaluated in this brief review.

Establishment of adult mouse Sertoli cell lines by using the starvation method

Sertoli cells were isolated from the testes of 6-week-old mice and stable Sertoli cell lines with higher proliferation rates were subcloned after starvation of primary cultured cells. After two rounds of this subcloning, 33 subcloned lines were selected on the basis of their proliferation rates. In addition, these subclones were screened according to their phagocytic activity and the characteristics of mature Sertoli cells, such as the expression of androgen receptors (ARs) and progesterone receptors, by using western blotting and immunocytochemical analysis, in addition to their morphology and proliferation rates. After the third round of subcloning, 12 subclones were selected for the final selection using RT-PCR for identification of genes specifically expressed by various testicular cells. Three clones were selected that expressed Sertoli-cell-specific genes, i.e. stem cell factor, clusterin, AR, α-inhibin, transferrin, Wilms' tumour-1, Müllerian inhibitory substance, sex-determining region Y-box 9, FSH receptor (Fshr) and occludin; however, these clones did not express globulin transcription factor 1, steroidogenic factor or androgen-binding protein. These clones also expressed growth and differentiation factors that act on germ cells, such as leukaemia inhibitory factor, transforming growth factor β1 and basic fibroblast growth factor 2, but did not express c-kit (specific for germ cells), LH receptor and 3β-hydroxyl-dehydrogenase (specific for Leydig cells). Immunocytochemical data confirmed the expression of clusterin in these clones. Furthermore, the Bromodeoxyuridine incorporation assay confirmed the proliferation activity of these clones throughFshrafter treatment with FSH. These clones are considered to be valuable tools for the study of Sertoli cell-specific gene expression and function.

Androgen/androgen receptor pathway regulates expression of the genes for cyclooxygenase-2 and amphiregulin in periovulatory granulosa cells

It is well known that the androgen/androgen receptor (AR) pathway is involved in both male and female fertility in mammals. AR knockout female mice are reported to exhibit various abnormalities in follicle development, and a subfertile phenotype. In exogenous gonadotropin-induced superovulation, serum androgen levels were robustly elevated in female mice at the periovulatory stage after human chorionic gonadotropin (hCG) treatment. At this stage, ovarian AR proteins were strongly expressed in cumulus cells. Because these results suggested that the androgen/AR pathway is involved in ovulation, we investigated the expression of ovulation-related genes in the mouse ovary treated with the nonaromatizable androgen, 5α-dihydrotestosterone (DHT). DHT treatment induced the expression of the genes for cyclooxyganase-2 (Cox-2 or prostaglandin endoperoxidase synthase 2) and the epidermal growth factor-like factor, amphiregulin (Areg), in the ovary, whereas their hCG-induced expression was suppressed by the AR antagonist flutamide. These genes were also induced by DHT in AR-expressing primary granulosa and granulosa tumor-derived cells. Reporter assays, electrophoretic shift mobility assays and chromatin immunoprecipitation assays demonstrated that androgen response sequence(s) existing upstream of each gene were responsible for androgen responsiveness and were occupied by the AR in periovulatory granulosa cells. Our results suggest that the androgen/AR pathway is involved in the ovulatory process via expression of the Cox-2 and Areg genes in periovulatory granulosa cells.

Targeting testis-specific proteins to inhibit spermatogenesis: lesson from endocrine disrupting chemicals

INTRODUCTION

Exposure to endocrine disrupting chemicals (EDCs) has recently been linked to declining fertility in men in both developed and developing countries. Since many EDCs possess intrinsic estrogenic or androgenic activities, thus, the gonad is one of the major targets of EDCs.

AREAS COVERED

For the past 2 decades, studies found in the literature regarding the disruptive effects of these EDCs on reproductive function in human males and also rodents were mostly focused on oxidative stress-induced germ cell apoptosis, disruption of steroidogenesis, abnormal sperm production and disruption of spermatogenesis in particular cell adhesion function and the blood-testis-barrier (BTB) function. Herein, we highlight recent findings in the field illustrating testis-specific proteins are also targets of EDCs.

EXPERT OPINION

This information should be helpful in developing better therapeutic approach to manage ECD-induced reproductive toxicity. This information is also helpful to identify potential targets for male contraceptive development.

Cholesterol and male fertility: what about orphans and adopted?

The link between cholesterol homeostasis and male fertility has been clearly suggested in patients who suffer from hyperlipidemia and metabolic syndrome. This has been confirmed by the generation of several transgenic mouse models or in animals fed with high cholesterol diet. Next to the alteration of the endocrine signaling pathways through steroid receptors (androgen and estrogen receptors); "orphan" and "adopted" nuclear receptors, such as the Liver X Receptors (LXRs), the Proliferating Peroxisomal Activated Receptors (PPARs) or the Liver Receptor Homolog-1 (LRH-1), have been involved in this cross-talk. These transcription factors show distinct expression patterns in the male genital tract, explaining the large panel of phenotypes observed in transgenic male mice and highlighting the importance of lipid homesostasis and the complexity of the molecular pathways involved. Increasing our knowledge of the roles of these nuclear receptors in male germ cell differentiation could help in proposing new approaches to either treat infertile men or define new strategies for contraception.

Molecular cloning, characterization, and gene expression of the androgen receptor in the large yellow croaker, Larimichthys crocea

Androgens mediate a wide range of physiological responses and developmental processes in vertebrates, involving both reproductive and nonreproductive systems. The activity of androgens is mediated by the androgen receptor (AR), a member of the nuclear receptor superfamily. In this study, an AR gene was cloned from the large yellow croaker (Larimichthys crocea) for the first time. qRT-PCR revealed ubiquitous expression of AR in all adult tissues examined, with higher expression in the gonad and liver of both sexes and highest expression in the blastula stage of embryonic development. Using in situ hybridization, we detected positive signals of AR in the spermatogonium, spermatocyte, spermatid, and spermatozoon during spermatogenesis, in the cytoplasm of all oocytes during oogenesis and in the follicle cells of stage IV oocytes. Our findings support the important role that AR plays in gametogenesis, gonadal development, and the early stages of embryonic development.

c-Yes regulates cell adhesion at the apical ectoplasmic specialization-blood-testis barrier axis via its effects on protein recruitment and distribution

During spermatogenesis, extensive restructuring takes place at the cell-cell interface since developing germ cells migrate progressively from the basal to the adluminal compartment of the seminiferous epithelium. Since germ cells per se are not motile cells, their movement relies almost exclusively on the Sertoli cell. Nonetheless, extensive exchanges in signaling take place between these cells in the seminiferous epithelium. c-Yes, a nonreceptor protein tyrosine kinase belonging to the Src family kinases (SFKs) and a crucial signaling protein, was recently shown to be upregulated at the Sertoli cell-cell interface at the blood-testis barrier (BTB) at stages VIII-IX of the seminiferous epithelial cycle of spermatogenesis. It was also highly expressed at the Sertoli cell-spermatid interface known as apical ectoplasmic specialization (apical ES) at stage V to early stage VIII of the epithelial cycle during spermiogenesis. Herein, it was shown that the knockdown of c-Yes by RNAi in vitro and in vivo affected both Sertoli cell adhesion at the BTB and spermatid adhesion at the apical ES, causing a disruption of the Sertoli cell tight junction-permeability barrier function, germ cell loss from the seminiferous epithelium, and also a loss of spermatid polarity. These effects were shown to be mediated by changes in distribution and/or localization of adhesion proteins at the BTB (e.g., occludin, N-cadherin) and at the apical ES (e.g., nectin-3) and possibly the result of changes in the underlying actin filaments at the BTB and the apical ES. These findings implicate that c-Yes is a likely target of male contraceptive research.

Testosterone deficiency accompanied by testicular and epididymal abnormalities in TMF(-/-) mice

TMF/ARA160 is a Golgi-associated protein, which is essential for spermiogenesis. In this study, we show that lack of TMF/ARA160 leads to defects in both the testis and the epididymis. In the testis, spermatid retention and extensive proliferation of Leydig cells were observed. Concomitantly, the serum levels of luteinizing hormone (LH), a stimulator of Leydig cell proliferation, were significantly increased in TMF(-/-) mice. Structural and functional defects were also seen in the epididymis. These included apoptosis of epithelial epididymal cells and sperm stasis in the cauda. Notably, the serum testosterone levels of TMF(-/-) mice were significantly lower than those of wt mice, and external testosterone administration decreased the number of apoptotic epithelial epididymal cells in TMF(-/-) animals. In summary, we show here for the first time that TMF/ARA160 participates in the control of serum testosterone levels in males, and its absence results in major testicular and epididymal defects.

RanBPM, a scaffolding protein for gametogenesis

RanBPM is a multimodular scaffold protein that interacts with a great variety of molecules including nuclear, cytoplasmic, and membrane proteins. By building multiprotein complexes, RanBPM is thought to regulate various signaling pathways, especially in the immune and nervous system. However, the diversity of these interactions does not facilitate the identification of its precise mechanism of action, and therefore the physiological role of RanBPM still remains unclear. Recently, RanBPM has been shown to be critical for the fertility of both genders in mouse. Although mechanistically it is still unclear how RanBPM affects gametogenesis, the data collected so far suggest that it is a key player in this process. Here, we examine the RanBPM sterility phenotype in the context of other genetic mutations affecting mouse gametogenesis to investigate whether this scaffold protein affects the function of other known proteins whose deficiency results in similar sterility phenotypes.

Long-term vitamin A deficiency induces alteration of adult mouse spermatogenesis and spermatogonial differentiation: direct effect on spermatogonial gene expression and indirect effects via somatic cells

The objective of this study was to further understand the genetic mechanisms of vitamin A deficiency (VAD) induced arrest of spermatogonial stem-cell differentiation. Vitamin A and its derivatives (the retinoids) participate in many physiological processes including vision, cellular differentiation and reproduction. VAD affects spermatogenesis, the subject of our present study. Spermatogenesis is a highly regulated process of differentiation and complex morphologic alterations that leads to the formation of sperm in the seminiferous epithelium. VAD causes early cessation of spermatogenesis, characterized by degeneration of meiotic germ cells, leading to seminiferous tubules containing mostly type A spermatogonia and Sertoli cells. These observations led us to the hypothesis that VAD affects not only germ cells but also somatic cells. To investigate the effects of VAD on spermatogenesis in mice we used adult Balb/C mice fed with Control or VAD diet for an extended period of time (6-28 weeks). We first observed the chronology, then the extent of the effects of VAD on the testes. Using microarray analysis of isolated pure populations of spermatogonia, Leydig and Sertoli cells from control and VAD 18- and 25-week mice, we examined the effects of VAD on gene expression and identified target genes involved in the arrest of spermatogonial differentiation and spermatogenesis. Our results provide a more precise definition of the chronology and magnitude of the consequences of VAD on mouse testes than the previously available literature and highlight direct and indirect (via somatic cells) effects of VAD on germ cell differentiation.

The consequences of mutations in the reproductive endocrine system

The reproductive activity in male mammals is well known to be regulated by the hypothalamus-pituitary- gonad axis. The hypothalamic neurons secreting gonadotropin releasing hormone (GnRH) govern the reproductive neuroendocrine system by integrating all the exogenous information impinging on themselves. The GnRH synthesized and released from the hypothalamus arrives at the anterior pituitary through the portal vessels, provoking the production of the gonadotropins(follicle-stimulating hormone (FSH) and luteinizing hormone (LH)) at the same time. The gonadotropins affect the gonads to promote spermatogenesis and to secret testosterone. Testosterone acts on the GnRH neurons by a feedback loop through the circulatory system, resulting in the balance of all the hormones by regulating reproductive activities. These hormones exert their effects by acting on their own receptors, which are included in the signal transduction pathways as well. Unexpected aberrants are arised during this course of action of each hormone. This review summarizes these abnormal phenomena, including various mutations of molecules and their actions related to the reproductive function.

The androgen receptor in health and disease

Androgens play pivotal roles in the regulation of male development and physiological processes, particularly in the male reproductive system. Most biological effects of androgens are mediated by the action of nuclear androgen receptor (AR). AR acts as a master regulator of downstream androgen-dependent signaling pathway networks. This ligand-dependent transcriptional factor modulates gene expression through the recruitment of various coregulator complexes, the induction of chromatin reorganization, and epigenetic histone modifications at target genomic loci. Dysregulation of androgen/AR signaling perturbs normal reproductive development and accounts for a wide range of pathological conditions such as androgen-insensitive syndrome, prostate cancer, and spinal bulbar muscular atrophy. In this review we summarize recent advances in understanding of the epigenetic mechanisms of AR action as well as newly recognized aspects of AR-mediated androgen signaling in both men and women. In addition, we offer a perspective on the use of animal genetic model systems aimed at eventually developing novel therapeutic AR ligands.

Androgen insensitivity syndrome

Androgen insensitivity syndrome in its complete form is a disorder of hormone resistance characterised by a female phenotype in an individual with an XY karyotype and testes producing age-appropriate normal concentrations of androgens. Pathogenesis is the result of mutations in the X-linked androgen receptor gene, which encodes for the ligand-activated androgen receptor--a transcription factor and member of the nuclear receptor superfamily. This Seminar describes the clinical manifestations of androgen insensitivity syndrome from infancy to adulthood, reviews the mechanism of androgen action, and shows examples of how mutations of the androgen receptor gene cause the syndrome. Management of androgen insensitivity syndrome should be undertaken by a multidisciplinary team and include gonadectomy to avoid gonad tumours in later life, appropriate sex-hormone replacement at puberty and beyond, and an emphasis on openness in disclosure.

Anabolic-androgenic steroids induce apoptosis and NOS2 (nitric-oxide synthase 2) in adult rat Leydig cells following in vivo exposure

Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone (T) predominantly taken as drugs of abuse. Using in vivo treatment of adult male rats we investigated the effects of testosterone enanthate (TE) a widely abused AAS, on apoptosis of Leydig cells. Increased T and decreased luteinizing hormone levels in serum and decreased intra-testicular T values were found in 2 and 10 weeks treated groups. Two weeks of TE-treatment stimulated the expression of inducible nitric oxide synthase (NOS2) followed by increased NO production, decreased mitochondrial membrane potential and increased prevalence of Leydig cell apoptosis. This was prevented by in vivo administration of androgen receptor blocker. The induced NOS2 level and apoptosis returned to control levels after 10 weeks of TE-treatment but testes contained fewer Leydig cells. Overall, AAS in addition to reduced steroidogenesis induce transient increase of Leydig cells apoptotic rate through mechanism associated with androgen receptor, most likely involving NOS2 induction.

Is matrix metalloproteinase required in postnatal testicular tubules for germ cell maturation?

BACKGROUND/AIM

Cryptorchidism may cause infertility by failed transformation of neonatal gonocytes into adult dark spermatogonia, the putative stem cells for spermatogenesis. Gonocytes migrate centrifugally to the tubular basement membrane to become adult dark spermatogonia. Regulation of this transformation remains unknown. We aimed to investigate neonatal rodent testis matrix metalloproteinase (MMP) production to see whether MMPs loosen extracellular matrix between Sertoli cells to facilitate gonocyte movement.

METHODS

Sprague-Dawley rat testes (n = 4-6 per group) were collected at embryonic day 19 (E19) and postnatal (P) days P0 to 10 for immunohistochemistry. Immunofluorescent confocal images were captured for presence of membrane type 1 MMP (MT1-MMP), matrix metalloproteinase 2 (MMP2), tissue inhibitor of metalloproteinase 2 (TIMP2), mouse VASA homologue, anti-Müllerian hormone, and androgen receptor in tissue sections. Testicular proteins were analyzed by immunoblotting.

RESULTS

Membrane type 1 MMP was strongly present in gonocytes at E19 then decreased, whereas it increased in testicular somatic cells from P0 to P10. Testicular protein levels of MT1-MMP, MMP2, and androgen receptor were constant from E19 to P10. Anti-Müllerian hormone protein sharply decreased after P2, whereas TIMP2 gradually increased from E19 to P10. Gonocytes migrated to basement membrane at P2 to P6.

CONCLUSION

Membrane type 1 MMP, MMP2, and TIMP2 were present in testis from E19 to P10 during gonocyte migration and transformation into spermatogenic stem cells. Increased knowledge about germ cell development may aid efforts to improve fertility in cryptorchidism.

Spermatogenesis arrest caused by conditional deletion of Hsp90α in adult mice

It is controversial whether a functional androgen receptor (AR) on germ cells, including spermatogonia, is essential for their development into sperm and, thus, initiation and maintenance of spermatogenesis. It was recently shown that many spermatocytes underwent apoptosis in the testes of Hsp90α KO mice. We had generated Hsp90α KO mice independently and confirmed this phenotype. However, the important question of whether Hsp90α is required to maintain spermatogenesis in adult mice in which testicular maturation is already completed could not be addressed using these conventional KO mice. To answer this question, we generated a tamoxifen-inducible deletion mutant of Hsp90α and found that conditional deletion of Hsp90α in adult mice caused even more severe apoptosis in germ cells beyond the pachytene stage, leading to complete arrest of spermatogenesis and testicular atrophy. Importantly, immunohistochemical analysis revealed that AR expression in WT testis was more evident in spermatogonia than in spermatocytes, whereas its expression was aberrant and ectopic in Hsp90α KO testis, raising the possibility that an AR abnormality in primordial germ cells is involved in spermatogenesis arrest in the Hsp90α KO mice. Our results suggest that the AR, specifically chaperoned by Hsp90α in spermatogonia, is critical for maintenance of established spermatogenesis and for survival of spermatocytes in adult testis, in addition to setting the first wave of spermatogenesis before puberty.

Proteomic changes in rat spermatogenesis in response to in vivo androgen manipulation; impact on meiotic cells

The production of mature sperm is reliant on androgen action within the testis, and it is well established that androgens act on receptors within the somatic Sertoli cells to stimulate male germ cell development. Mice lacking Sertoli cell androgen receptors (AR) show late meiotic germ cell arrest, suggesting Sertoli cells transduce the androgenic stimulus co-ordinating this essential step in spermatogenesis. This study aimed to identify germ cell proteins responsive to changes in testicular androgen levels and thereby elucidate mechanisms by which androgens regulate meiosis. Testicular androgen levels were suppressed for 9 weeks using testosterone and estradiol-filled silastic implants, followed by a short period of either further androgen suppression (via an AR antagonist) or the restoration of intratesticular testosterone levels. Comparative proteomics were performed on protein extracts from enriched meiotic cell preparations from adult rats undergoing androgen deprivation and replacement in vivo. Loss of androgenic stimulus caused changes in proteins with known roles in meiosis (including Nasp and Hsp70–2), apoptosis (including Diablo), cell signalling (including 14-3-3 isoforms), oxidative stress, DNA repair, and RNA processing. Immunostaining for oxidised DNA adducts confirmed spermatocytes undergo oxidative stress-induced DNA damage during androgen suppression. An increase in PCNA and an associated ubiquitin-conjugating enzyme (Ubc13) suggested a role for PCNA-mediated regulation of DNA repair pathways in spermatocytes. Changes in cytoplasmic SUMO1 localisation in spermatocytes were paralleled by changes in the levels of free SUMO1 and of a subunit of its activating complex, suggesting sumoylation in spermatocytes is modified by androgen action on Sertoli cells. We conclude that Sertoli cells, in response to androgens, modulate protein translation and post-translational events in spermatocytes that impact on their metabolism, survival, and completion of meiosis.

Patterns of molecular evolution of an avian neo-sex chromosome

Newer parts of sex chromosomes, neo-sex chromosomes, offer unique possibilities for studying gene degeneration and sequence evolution in response to loss of recombination and population size decrease. We have recently described a neo-sex chromosome system in Sylvioidea passerines that has resulted from a fusion between the first half (10 Mb) of chromosome 4a and the ancestral sex chromosomes. In this study, we report the results of molecular analyses of neo-Z and neo-W gametologs and intronic parts of neo-Z and autosomal genes on the second half of chromosome 4a in three species within different Sylvioidea lineages (Acrocephalidea, Timaliidae, and Alaudidae). In line with hypotheses of neo-sex chromosome evolution, we observe 1) lower genetic diversity of neo-Z genes compared with autosomal genes, 2) moderate synonymous and weak nonsynonymous sequence divergence between neo-Z and neo-W gametologs, and 3) lower GC content on neo-W than neo-Z gametologs. Phylogenetic reconstruction of eight neo-Z and neo-W gametologs suggests that recombination continued after the split of Alaudidae from the rest of the Sylvioidea lineages (i.e., after ~42.2 Ma) and with some exceptions also after the split of Acrocephalidea and Timaliidae (i.e., after ~39.4 Ma). The Sylvioidea neo-sex chromosome shares classical evolutionary features with the ancestral sex chromosomes but, as expected from its more recent origin, shows weaker divergence between gametologs.

Androgen-responsive microRNAs in mouse Sertoli cells

Although decades of research have established that androgen is essential for spermatogenesis, androgen's mechanism of action remains elusive. This is in part because only a few androgen-responsive genes have been definitively identified in the testis. Here, we propose that microRNAs – small, non-coding RNAs – are one class of androgen-regulated trans-acting factors in the testis. Specifically, by using androgen suppression and androgen replacement in mice, we show that androgen regulates the expression of several microRNAs in Sertoli cells. Our results reveal that several of these microRNAs are preferentially expressed in the testis and regulate genes that are highly expressed in Sertoli cells. Because androgen receptor-mediated signaling is essential for the pre- and post-meiotic germ cell development, we propose that androgen controls these events by regulating Sertoli/germ cell-specific gene expression in a microRNA-dependent manner.

Subfertile effects of quinestrol and levonorgestrel in male rats

The contraceptive regimen consisting of levonorgestrel and quinestrol (EP-1) has been shown to be effective in several types of wild rodents. In the present study, we investigated the effect of EP-1 and its two components on fertility and spermatogenesis to elucidate the mechanisms underlying its contraceptive effect. Sprague-Dawley rats were treated with 0.33 mgkg(-1) quinestrol (E group), 0.67 mgkg(-1) levonorgestrel (P group) or their combination (EP group) for 7 days and then killed on Days 21 or 42 after treatment for tissue analysis. On Day 21, the weight of the cauda epididymis decreased significantly, while the weight of the adrenal gland increased significantly in the E and EP groups compared with the weights in the control group. In addition, there was a significant decrease in sperm number in the E and EP groups compared with the control group and there was less staining for the androgen receptor and Wilms' tumour nuclear protein 1 in the E and EP groups. The primary defects in E- or EP-treated rats were abnormal spermiogenesis, lack of elongating spermatids, and pachytene spermatocyte arrest. Analysis of MutL homologue 1 revealed that EP treatment inhibited chromosome recombination during meiosis, but did not cause obvious genetic abnormalities. These data demonstrate that quinestrol, alone or in combination with levonorgestrel, induces subfertility in male rats mainly by interfering with germ cell differentiation. Thus, EP-1 or E alone may be effective contraceptive regimens for fertility control in rodents.

Repeated immobilization stress disturbed steroidogenic machinery and stimulated the expression of cAMP signaling elements and adrenergic receptors in Leydig cells

This study was designed to evaluate the effect of acute (2 h daily) and repeated (2 h daily for 2 or 10 consecutive days) immobilization stress (IMO) on: 1) the steroidogenic machinery homeostasis; 2) cAMP signaling; and the expression of receptors for main markers of 3) adrenergic and 4) glucocorticoid signaling in Leydig cells of adult rats. The results showed that acute IMO inhibited steroidogenic machinery in Leydig cells by downregulation of Scarb1 (scavenger receptor class B), Cyp11a1 (cholesterol side-chain cleavage enzyme), Cyp17a1 (17α-hydroxylase/17,20 lyase), and Hsd17b3 (17β-hydroxysteroid dehydrogenase) expression. In addition to acute IMO effects, repeated IMO increased transcription of Star (steroidogenic acute regulatory protein) and Arr19 (androgen receptor corepressor 19 kDa) in Leydig cells. In the same cells, the transcription of adenylyl cyclases (Adcy7, Adcy9, Adcy10) and cAMP-specific phosphodiesterases (Pde4a, Pde4b, Pde4d, Pde7a, Pde8a) was stimulated, whereas the expression of the genes encoding protein kinase A subunits were unaffected. Ten times repeated IMO increased the levels of all adrenergic receptors and β-adrenergic receptor kinase (Adrbk1) in Leydig cells. The transcription analysis was supported by cAMP/testosterone production. In this signaling scenario, partial recovery of testosterone production in medium/content was detected. The physiological significance of the present results was proven by ex vivo application of epinephrine, which increased cAMP/testosterone production by Leydig cells from control rats in greater fashion than from stressed. IMO did not affect the expression of transcripts for Crhr1/Crhr2 (corticotropin releasing hormone receptors), Acthr (adrenocorticotropin releasing hormone receptor), Gr (glucocorticoid receptor), and Hsd11b1 [hydroxysteroid (11-β) dehydrogenase 1], while all types of IMO stimulated the expression of Hsd11b2, the unidirectional oxidase with high affinity to inactivate glucocorticoids. Thus, presented data provide new molecular/transcriptional base for "fight/adaptation" of Leydig cells and new insights into the role of cAMP, epinephrine, and glucocorticoid signaling in recovery of stress-impaired Leydig cell steroidogenesis.

Tissue- and cell-specific functions of the androgen receptor revealed through conditional knockout models in mice

This review aims to evaluate the contribution of individual cell-selective knockout models to our current understanding of androgen action. Cre/loxP technology has allowed the generation of cell-selective knockout models targeting the androgen receptor (AR) in distinct putative target cells in a wide variety of organs and tissues including: testis, ovary, accessory sex tissues, muscle, bone, fat, liver, skin and myeloid tissue. In some androgen-regulated processes such as spermatogenesis and folliculogenesis this approach has lead to the identification of a key cellular mediator of androgen action (Sertoli and granulosa cells, respectively). In many target tissues, however, the final response to androgens appears to be more complex. Here, cell-selective knockout technology offers a platform upon which we can begin to unravel the more complex interplay and signaling pathways of androgens. A prototypic example is the analysis of mesenchymal-epithelial interactions in many accessory sex glands. Furthermore, for some actions of testosterone, in which part of the effect is mediated by the active metabolite 17β-estradiol, conditional knockout technology offers a novel strategy to study the relative contribution of AR and estrogen receptor-mediated signaling. The latter approach has already resulted in a better understanding of androgen action in brain and bone. Finally, cell-selective knockout technology has generated valuable models to search for AR-controlled molecular mediators of androgen action, a strategy that has successfully been applied to the study of androgen action in the testis and in the epididymis. Although some conditional knockout models have provided clear answers to physiologic questions, it should be noted that others have pointed to unexpected complexities or technical limitations confounding interpretation of the results.

The protective effects of quercetin on the cytotoxicity of atrazine on rat Sertoli-germ cell co-culture

To evaluate the direct effect of atrazine (ATZ) and the protective effect of quercetin (QT) on testicular cells, we used primary cultures of rat Sertoli-germ cells (SGCs). ATZ (232 μm) up-regulated the mRNA expression of GATA-4, androgen receptor (AR), androgen-binding protein (ABP), steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage enzyme (CYP11A1), cyclooxygenase-2 (COX-2) and NF-κappaB (NF-κB) and down-regulated the expression of stem cell factor (SCF) mRNA. There was no change on the mRNA expression of oestrogen receptor-alpha (ER-α). Simultaneous supplementation of QT in the culture normalizes the expression of these genes. The stimulatory action of follicle stimulating hormone (10 ng/mL) on ATZ-induced StAR and CYP11A1 mRNA levels were also prevented by QT. Furthermore, ATZ-stimulatory action on AR mRNA was opposed in a dose-dependent manner in the presence of increasing concentrations of QT (10-50 μm).The dislodgement of germ cells from the Sertoli cells monolayer and decrease in SGCs viability was prevented by QT. To show whether or not the disrupted interactions of Sertoli and germ cells impaired spermatogenesis, adult male rats exposed in vivo to ATZ (50 mg/kg b.wt) for 1 week had their daily spermatozoa production (DSP) per gram testis lowered by 30%. DSP was significantly increased in the QT(10 mg/kg) + ATZ-treated rats as compared with the ATZ-treated rats. Taken together, ATZ can alter SGCs expression of spermatogenesis- and steroiodogenesis-related genes resulting in a decrease in sperm production in the testis as well as cell viability. QT might block these molecular events-induced by ATZ thereby protecting testicular Sertoli-germ cells from ATZ-induced toxicity.

A model of delivering multi-disciplinary care to people with 46 XY DSD

In 2006, a consensus statement was jointly produced by the Lawson Wilkins Pediatric Endocrine Society (LWPES) and the European Society of Paediatric Endocrinology (ESPE) concerning the management of disorders of sex development (DSD) [1]. A recommendation provided by this consensus was that evaluation and long-term care for people affected by DSD should be performed at medical centers with multi-disciplinary teams experienced in such conditions. Here we provide our team's interpretation of the 2006 consensus statement recommendations and its translation into a clinical protocol for individuals affected by 46 XY DSD with either female, or ambiguous, genitalia at birth. Options for medical and surgical management, transitioning of care, and the use of mental health services and peer support groups are discussed. Finally, we provide preliminary data to support the application of our model for delivering multi-disciplinary care and support to patients and their families.