Possible fetal determinants of male infertility

Prepregnancy and Gestational Interventions to Prevent Childhood Obesity

Childhood obesity is a significant global health issue with complex and multifactorial origins, often beginning before conception and influenced by both maternal and paternal health. The increased prevalence of prepregnancy obesity and gestational diabetes mellitus in women of reproductive age contributes to a heightened risk of metabolic dysfunction in offspring. Current clinical practices often implement lifestyle interventions after the first trimester and have limited success, implying that they miss a critical window for effective metabolic adjustments. This review examines the limitations of lifestyle interventions during pregnancy in improving perinatal outcomes and highlights the importance of initiating such interventions before conception to positively impact parental health and fetal development. A re-evaluation of strategies is needed to enhance the metabolic health of prospective parents as a preventive measure against childhood obesity.

Associations between prenatal exposure to metal mixtures and infant reproductive hormones during mini-puberty

BACKGROUND

The reproductive hormone homeostasis is crucial for child development. Exposure to metals during pregnancy may have adverse effects on offspring health. However, the association between prenatal exposure to metals and infant reproductive hormone levels remains unknown.

METHODS

This study involved 812 mother-infant pairs from Wuhan, China, assessing prenatal exposure to 13 metals in maternal plasma during early pregnancy and measuring five reproductive hormones in urine samples of one-month-old infants. Generalized linear models were employed to investigate the associations between individual metal exposures and urinary hormone levels in infants. Additionally, weighted quantile sum (WQS) regression and quantile g-computation were employed to evaluate the impact of metal mixtures.

RESULTS

Most of the detected metals in maternal plasma were associated with lower levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in infants. Each interquartile range (IQR) increase in manganese (Mn), barium (Ba), thallium (Tl), vanadium (V), cobalt (Co), nickel (Ni), and lead (Pb) was significantly associated with an approximately 9.87 % to 38.24 % decrease in FSH or LH. WQS and quantile g-computation models confirmed a significant association between prenatal metal mixtures and reduced FSH and LH in male infants, and WQS indicated a significant association between metal mixtures and decreased FSH in female infants.

CONCLUSIONS

Maternal exposure to mixed metals during early pregnancy was associated with lower levels of FSH and LH in infants, suggesting that prenatal exposure to metals may disrupt the balance of infant reproductive hormones. Further research is warranted to confirm these associations and explore the underlying mechanisms.

Longitudinal Evaluation of Fetal and Infant AGD in Healthy Children: Association With Penile Size, Testosterone, and DHT

CONTEXT

The anogenital distance (AGD) is considered a postnatal readout of early fetal androgen action. Little is known of prenatal AGD and how it correlates with AGD postnatally.

OBJECTIVE

We present longitudinal measurements of fetal and infant AGD. We evaluate the impact of testosterone and dihydrotestosterone at minipuberty on AGD and penile size.

METHODS

We performed secondary analyses of an observational, prospective pregnancy and birth cohort, COPANA (2020-2022), at Copenhagen University Hospital-Rigshospitalet, enrolling 685 healthy, singleton pregnant women, of whom 657 attended third trimester ultrasound and 589 infants completed follow-up. Fetal AGD was measured at third semester ultrasound (gestational week 29-34), and infant AGD, penile width, stretched penile length, and circulating testosterone and dihydrotestosterone (LC-MS/MS) were assessed at the minipuberty clinical examination (approximately 3.5 months postpartum).

RESULTS

AGD was available in 650/657 fetuses (310 boys) and 588/589 infants (287 boys). Boys had longer fetal and infant AGD than girls; fetal AGDas: mean (SD) 21.4 mm (±3.5), fetal AGDaf: 12.8 mm (±2.3), P < .001, infant AGDas: 32.0 mm (±5.6) and infant AGDaf: 15.8 (±3.3), P < .001. Fetal AGD correlated with infant AGD in boys and girls (Spearman r = .275, P < .001 and r = .189, P = .001 respectively), but not with circulating testosterone or dihydrotestosterone at minipuberty. Penile size correlated positively with circulating androgen levels at minipuberty: stretched penile length vs testosterone: r = .235, P < .001.

CONCLUSION

AGD is sexually dimorphic already in the third trimester. Fetal and infant AGD correlate. AGD is associated with body size but not circulating androgen levels at minipuberty. These findings suggest that fetal and infant AGD reflect androgen action during early fetal development.

"Management of andrological disorders from childhood and adolescence to transition age: guidelines from the Italian Society of Andrology and Sexual Medicine (SIAMS) in collaboration with the Italian Society for Pediatric Endocrinology and Diabetology (SIEDP)-Part-1"

PURPOSE

Andrological pathologies in the adulthood are often the results of conditions that originate during childhood and adolescence and sometimes even during gestation and neonatal period. Unfortunately, the reports in the literature concerning pediatric andrological diseases are scares and mainly concerning single issues. Furthermore, no shared position statement are so far available.

METHODS

The Italian Society of Andrology and Sexual Medicine (SIAMS) commissioned an expert task force involving the Italian Society of Pediatric Endocrinology and Diabetology (SIEDP) to provide an updated guideline on the diagnosis and management of andrological disorders from childhood and adolescence to transition age. Derived recommendations were based on the grading of recommendations, assessment, development, and evaluation (GRADE) system.

RESULTS

A literature search of articles in English for the term "varicoceles", "gynecomastia", "fertility preservation", "macroorchidism", "precocious puberty" and "pubertal delay" has been performed. Three major aspects for each considered disorder were assessed including diagnosis, clinical management, and treatment. Recommendations and suggestions have been provided for each of the mentioned andrological disorders.

CONCLUSIONS

These are the first guidelines based on a multidisciplinary approach that involves important societies related to the field of andrological medicine from pediatric to transition and adult ages. This fruitful discussion allowed for a general agreement on several recommendations and suggestions to be reached, which can support all stakeholders in improving andrological and general health of the transitional age.

Male animal sterilization: history, current practices, and potential methods for replacing castration

Sterilization and castration have been synonyms for thousands of years. Making an animal sterile meant to render them incapable of producing offspring. Castration or the physical removal of the testes was discovered to be the most simple but reliable method for managing reproduction and sexual behavior in the male. Today, there continues to be global utilization of castration in domestic animals. More than six hundred million pigs are castrated every year, and surgical removal of testes in dogs and cats is a routine practice in veterinary medicine. However, modern biological research has extended the meaning of sterilization to include methods that spare testis removal and involve a variety of options, from chemical castration and immunocastration to various methods of vasectomy. This review begins with the history of sterilization, showing a direct link between its practice in man and animals. Then, it traces the evolution of concepts for inducing sterility, where research has overlapped with basic studies of reproductive hormones and the discovery of testicular toxicants, some of which serve as sterilizing agents in rodent pests. Finally, the most recent efforts to use the immune system and gene editing to block hormonal stimulation of testis function are discussed. As we respond to the crisis of animal overpopulation and strive for better animal welfare, these novel methods provide optimism for replacing surgical castration in some species.

Reproductive chemical database: a curated database of chemicals that modulate protein targets regulating important reproductive biological processes

Recent studies have shifted the spotlight from adult disease to gametogenesis and embryo developmental events, and these are greatly affected by various environmental chemicals, such as drugs, metabolites, pollutants, and others. Growing research has highlighted the critical importance of identifying and understanding the roles of chemicals in reproductive biology. However, the functions and mechanisms of chemicals in reproductive processes remain incomplete. We developed a comprehensive database called the Reproductive Chemical Database (RCDB) ( https://yu.life.sjtu.edu.cn/ChenLab/RCDB ) to facilitate research on chemicals in reproductive biology. This resource is founded on rigorous manual literature extraction and precise protein target prediction methodologies. This database focuses on the delineation of chemicals associated with phenotypes, diseases, or endpoints intricately associated with four important reproductive processes: female and male gamete generation, fertilization, and embryo development in human and mouse. The RCDB encompasses 93 sub-GO processes, and it revealed 1447 intricate chemical-biological process interactions. To date, the RCDB has meticulously cataloged and annotated 830 distinct chemicals, while also predicting 614 target proteins from a selection of 3800 potential candidates. Additionally, the RCDB offers an online predictive tool that empowers researchers to ascertain whether specific chemicals play discernible functional roles in these reproductive processes. The RCDB is an exhaustive, cross-platform, manually curated database, which provides a user-friendly interface to search, browse, and use reproductive processes modulators and their comprehensive related information. The RCDB will help researchers to understand the whole reproductive process and related diseases and it has the potential to promote reproduction research in the pharmacological and pathophysiological areas.

Cohort profile: The Copenhagen Analgesic Study-The COPANA cohort

BACKGROUND

Development of the gonads during fetal life is complex and vital for adult reproductive health. Cell and animal studies have shown an alarming effect of mild analgesics on germ cells in both males and females. More than 50% of pregnant women use mild analgesics during pregnancy, which potentially could compromise the reproductive health of the next generation.

OBJECTIVES

We present a research protocol designed to evaluate the effect of prenatal exposure to mild analgesics and endocrine-disrupting chemicals on gonadal function in the offspring.

POPULATION

Healthy, singleton pregnant women and their partners.

DESIGN

The COPANA cohort is a prospective, observational pregnancy and birth cohort.

METHODS

Participants were enrolled during the first trimester of pregnancy. Information on the use of mild analgesics was collected retrospectively 3 months prior to pregnancy and prospectively every 2 weeks throughout the study. We collected extensive data on lifestyle and reproductive health. Biospecimens were collected in the first trimester (maternal and paternal urine- and blood samples), in the third trimester in conjunction with a study-specific ultrasound scan (maternal urine sample), and approximately 3 months post-partum during the infant minipuberty period (maternal and infant urine- and blood samples). A comprehensive evaluation of reproductive function in the infants during the minipuberty phase was performed, including an ultrasound scan of the testis or ovaries and uterus.

PRELIMINARY RESULTS

In total, 685 pregnant women and their partners were included between March 2020 and January 2022. A total of 589 infants (287 males) and their parents completed the follow-up during the minipuberty phase (December 2020-November 2022).

CONCLUSIONS

The Copenhagen Analgesic Study holds the potential to provide novel and comprehensive insights into the impact of early and late prenatal exposure to mild analgesics and other endocrine-disrupting chemicals on future reproductive function in the offspring.

Splicing factor SRSF1 is essential for homing of precursor spermatogonial stem cells in mice

Spermatogonial stem cells (SSCs) are essential for continuous spermatogenesis and male fertility. The underlying mechanisms of alternative splicing (AS) in mouse SSCs are still largely unclear. We demonstrated that SRSF1 is essential for gene expression and splicing in mouse SSCs. Crosslinking immunoprecipitation and sequencing data revealed that spermatogonia-related genes (e.g. Plzf, Id4, Setdb1, Stra8, Tial1/Tiar, Bcas2, Ddx5, Srsf10, Uhrf1, and Bud31) were bound by SRSF1 in the mouse testes. Specific deletion of Srsf1 in mouse germ cells impairs homing of precursor SSCs leading to male infertility. Whole-mount staining data showed the absence of germ cells in the testes of adult conditional knockout (cKO) mice, which indicates Sertoli cell-only syndrome in cKO mice. The expression of spermatogonia-related genes (e.g. Gfra1, Pou5f1, Plzf, Dnd1, Stra8, and Taf4b) was significantly reduced in the testes of cKO mice. Moreover, multiomics analysis suggests that SRSF1 may affect survival of spermatogonia by directly binding and regulating Tial1/Tiar expression through AS. In addition, immunoprecipitation mass spectrometry and co-immunoprecipitation data showed that SRSF1 interacts with RNA splicing-related proteins (e.g. SART1, RBM15, and SRSF10). Collectively, our data reveal the critical role of SRSF1 in spermatogonia survival, which may provide a framework to elucidate the molecular mechanisms of the posttranscriptional network underlying homing of precursor SSCs.

Prenatal exposure to bisphenol A and neonatal health outcomes: A systematic review

Bisphenol A (BPA) is an endocrine-disrupting chemical substance responsible for the composition of polycarbonate plastics and epoxy resins. Early life and pregnancy are important windows of susceptibility. This review aimed to conduct a systematic assessment of human studies to comprehensively describe the association between prenatal BPA exposure and neonatal health outcomes. Literature was searched in Cochrane Library, Embase, PubMed, Scopus, and Web of Science published before November 2022, and were selected according to clear inclusion and exclusion criteria. The Newcastle-Ottawa scale (NOS) and Grades of Recommendation, Assessment, Development, and Evaluation guidelines (GRADE) were followed to grade the methodological quality of studies and the certainty of the evidence respectively. As a result, a total of 22259 participants from 45 trials were included. And the potential associations of prenatal exposure to BPA and neonatal health outcomes were mainly shown in four aspects: gestational age/preterm birth, physical health at birth, the incidence of systemic abnormalities or diseases, and other health outcomes. Although the certainty of the evidence was low to very low, the methodological quality of the included studies was high. Prenatal BPA exposure tended to have negative effects on most of the health outcomes in neonates but showed inconsistent results on physical health at birth. This systematic review is the first to comprehensively synthesize the existing evidence on the association between prenatal BPA exposure and neonatal health outcomes. In the future, further studies are still needed to verify these effects and elucidate the underlying mechanisms.

Association between Late Manifestations of Testicular Dysgenesis Syndrome and Anogenital Distance: A Systematic Review and Meta-analysis

Background

In 2001, Skakkebæk et al. proposed that certain male reproductive disorders might be grouped into a syndrome called testicular dysgenesis syndrome (TDS), as they all appear to be associated with disruption of the embryonic and foetal programming of gonadal development. TDS may be manifested in early life by the presence of genital malformations (hypospadias and cryptorchidism) and in adult life as disorders represented by low sperm counts and testicular cancer. Changes in androgen hormones during the foetal development, in addition to resulting in TDS, can also cause permanent changes in anopenile anogenital distance (AGDap) and anoscrotal anogenital distance (AGDas).

Aims

The objective of this study was to determine whether there is a relationship between late manifestations of TDS and reduced anogenital/anoscrotal distance.

Materials and Methods

The present study is a systematic review and meta-analysis. The research included papers from 2001 to 2020, comprising a total of 737 articles, and 13 articles were selected.

Results

Linear regression analysis was performed to evaluate the relationship between the two anogenital distance measures, which showed a significant positive association (P = 0.039). A meta-analysis was also performed and compared AGDap and AGDas between control and case groups, with cases defined as men with any late TDS manifestation. These data showed a significant reduction in AGDas in the affected population (P = 0.04), but no differences in the AGDap measure (P = 0.59).

Conclusion

Our study confirmed a significant relationship between reduced AGDas and late manifestations of TDS, providing further support to the association between prenatal androgen deficiency and late-onset reproductive disorders.

Onco-TESE (Testicular Sperm Extraction): Insights from a Tertiary Center and Comprehensive Literature Analysis

Background and Objectives: The peak of incidence of testicular cancer (TC) occurs among individuals in their reproductive age, emphasizing the importance of fertility preservation as an integral aspect of disease management. Sperm cryopreservation performed before orchiectomy is ineffective in azoospermic men, necessitating alternative approaches such as microdissection testicular sperm extraction (mTESE) at the time of orchiectomy (onco-mTESE) to obtain viable sperm. This study presents the findings from our institution's experience with onco-mTESE and critically discusses our results in light of the existing body of literature. Materials and Methods: This is a tertiary center retrospective analysis of onco-mTESE procedures performed at a single center between December 2011 and July 2022. The included patients were post-puberal men with testicular tumors requiring orchiectomy, along with concomitant severe oligozoospermia or azoospermia. Bilateral mTESE was performed in all cases. Surgical outcomes, sperm retrieval rates, the usage of preserved viable sperm, assistive reproductive techniques' results, and post-operative serum testosterone were recorded. Results: A total of nine patients were included, with a median age of 34 (IQR 29-36) years. All patients had germ cell tumors (GCTs), with seminomatous and non-seminomatous GCTs accounting for 44.4% (n = 4) and 55.6% (n = 5) of patients, respectively. Sperm retrieval occurred in three (33%) patients: one patient in the ipsilateral testis, one in the contralateral testis, and one in both testes. No complications were reported during the procedure, and no post-operative hypogonadism was observed. Among the three patients with successful sperm retrieval, an intracytoplasmic sperm injection (ICSI) was performed in two patients, resulting in two pregnancies, leading to one healthy live birth and one miscarriage. Conclusions: In the context of TC, it is essential to conduct a thorough evaluation of testicular function, including a semen analysis and cryopreservation. Onco-mTESE has proven its safety in preserving fertility in azoospermic cases while ensuring the efficacy of oncological treatment.

Cumulative Risk Evaluation of Phthalates Under TSCA

The U.S. Environmental Protection Agency (EPA) is currently conducting separate Toxic Substances Control Act (TSCA) risk evaluations for seven phthalates: dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), diisobutyl phthalate (DIBP), dicyclohexyl phthalate (DCHP), di-isodecyl phthalate (DIDP), and diisononyl phthalate (DINP). Phthalates are highly abundant plastic additives used primarily to soften materials and make them flexible, and biomonitoring shows widespread human exposure to a mixture of phthalates. Evidence supports biological additivity of phthalate mixture exposures, including the enhancement of toxicity affecting common biological targets. Risk estimates based on individual phthalate exposure may not be protective of public health. Thus, a cumulative risk approach is warranted. While EPA initially did not signal that it would incorporate cumulative risk assessment (CRA) as part of its current risk evaluation for the seven phthalates, the agency recently announced that it is reconsidering if CRA for phthalates would be appropriate. Based on our review of existing chemical mixtures risk assessment guidance, current TSCA scoping documents for the seven phthalates, and pertinent peer-reviewed literature, we delineate a CRA approach that EPA can easily implement for phthalates. The strategy for using CRA to inform TSCA risk evaluation for existing chemicals is based upon integrative physiology and a common adverse health outcome algorithm for identifying and grouping relevant nonchemical and chemical stressors. We recommend adjustments for how hazard indices (HIs) or margins of exposure (MOEs) based on CRA are interpreted for determining "unreasonable risk" under TSCA.

Metzincin metalloproteases in PGC migration and gonadal sex conversion

Development of a functional gonad includes migration of primordial germ cells (PGCs), differentiations of somatic and germ cells, formation of primary follicles or spermatogenic cysts with somatic gonadal cells, development and maturation of gametes, and subsequent releasing of mature germ cells. These processes require extensive cellular and tissue remodeling, as well as broad alterations of the surrounding extracellular matrix (ECM). Metalloproteases, including MMPs (matrix metalloproteases), ADAMs (a disintegrin and metalloproteinases), and ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs), are suggested to have critical roles in the remodeling of the ECM during gonad development. However, few research articles and reviews are available on the functions and mechanisms of metalloproteases in remodeling gonadal ECM, gonadal development, or gonadal differentiation. Moreover, most studies focused on the roles of transcription and growth factors in early gonad development and primary sex determination, leaving a significant knowledge gap on how differentially expressed metalloproteases exert effects on the ECM, cell migration, development, and survival of germ cells during the development and differentiation of ovaries or testes. We will review gonad development with focus on the evidence of metalloprotease involvements, and with an emphasis on zebrafish as a model for studying gonadal sex differentiation and metalloprotease functions.

Aryl hydrocarbon receptor activity in human breast milk and cryptorchidism: A case-control study within the prospective Norwegian HUMIS cohort

BACKGROUND

The etiology of cryptorchidism remains poorly understood. Endocrine disrupting chemicals can impact estrogen signaling by interacting with aryl hydrocarbon receptor (AhR) activity.

OBJECTIVE

To evaluate whether AhR activity in breast milk samples is associated with cryptorchidism.

METHOD

We conducted a case-control study based on 199 mother-child pairs (n = 91 cases/108 controls) selected from the Norwegian Human Milk Study (2002-2009). We defined cases for cryptorchidism based on maternal reports at 1-, 6-, 12-, and 24- months after birth. Chemically- and biologically stable AhR activity (pg 2,3,7,8-TCDD equivalent (TEQ)/g lipid) was determined by DR- CALUX® assay in the mothers' milk collected at a median of 33 (10th-90th percentile: 18-57) days after delivery. We used multivariate logistic regression to compare AhR activity levels between cases and controls, and linear regression separately, to establish the relationship with the presence of 27 potential EDCs measured in breast milk and AhR activity.

RESULTS

The average estimated daily intake (EDI) of dioxin and (dioxin-like (dl)-compounds via breast milk is 33.7 ± 17.9 pg TEQ/kg bodyweight per day among Norwegian children. There were no significant differences in AhR activation in breast milk samples between cases with cryptorchidism and controls. Among the 27 chemicals measured in breast milk, AhR activity was (borderline) significantly associated with all dl-PCBs, three non-dioxin-like (ndl)-PCBs (PCB-74, PCB-180, PCB-194) and two organochlorine pesticides (OCPs; HCB, β-HCH). No associations between AhR activity and brominated flame retardants (PBDEs) or poly- and perfluoroalkyl substances (PFASs).

CONCLUSION

No association between AhR activity and cryptorchidism was found among Norwegian boys. The average EDI of dioxin and dl-compounds in exclusively breastfed Norwegian infants remains above the safety threshold and, therefore requires further reduction measures. Consistent with a possible role in the observed AhR activity, all dl-PCBs were associated with AhR activity whereas the association was null for either PBDEs or PFASs.

Maternal Serum α-Fetoprotein Levels during Pregnancy and Testicular Cancer in Male Offspring: A Cohort Study within a Danish Pregnancy Screening Registry

Testicular cancer is believed to originate from disruptions of normal androgen-estrogen balance in-utero. α-fetoprotein (AFP) may modify fetal response to estrogens via estrogen interaction. In a cohort study, we investigated the association between circulating maternal pregnancy AFP and testicular cancer risk in offspring. Of the 56,709 live-born males from a pregnancy screening registry in 1980-1995, our study included 50,519 singleton males with available second trimester blood samples from their mothers and complete covariate ascertainment. Testicular cancer diagnoses and covariate data were obtained from nationwide Danish health registries. Cox regression and Kaplan-Meier analyses estimated the prospective risk of testicular cancer (all, seminoma, nonseminoma) by AFP multiples of the median. During follow-up, 163 (0.3%) of the included males developed testicular cancer, of which 89 (54.6%) were nonseminomas. Maternal serum AFP levels greater than/equal to the median were associated with a relative risk of testicular cancer close to unity (RR 1.04, 95% CI 0.76; 1.41) compared to AFP below the median. Associations differed by type of testicular cancer (RR_seminoma 0.81, 95% CI 0.51; 1.29, RR_nonseminoma 1.31, 95% CI 0.85; 2.02). On balance, our findings do not support that serum AFP in pregnancy can be used as a predictor of testicular cancer in offspring.

Identification of a window of androgen sensitivity for somatic cell function in human fetal testis cultured ex vivo

BACKGROUND

Reduced androgen action during early fetal development has been suggested as the origin of reproductive disorders comprised within the testicular dysgenesis syndrome (TDS). This hypothesis has been supported by studies in rats demonstrating that normal male development and adult reproductive function depend on sufficient androgen exposure during a sensitive fetal period, called the masculinization programming window (MPW). The main aim of this study was therefore to examine the effects of manipulating androgen production during different timepoints during early human fetal testis development to identify the existence and timing of a possible window of androgen sensitivity resembling the MPW in rats.

METHODS

The effects of experimentally reduced androgen exposure during different periods of human fetal testis development and function were examined using an established and validated human ex vivo tissue culture model. The androgen production was reduced by treatment with ketoconazole and validated by treatment with flutamide which blocks the androgen receptor. Testicular hormone production ex vivo was measured by liquid chromatography-tandem mass spectrometry or ELISA assays, and selected protein markers were assessed by immunohistochemistry.

RESULTS

Ketoconazole reduced androgen production in testes from gestational weeks (GW) 7-21, which were subsequently divided into four age groups: GW 7-10, 10-12, 12-16 and 16-21. Additionally, reduced secretion of testicular hormones INSL3, AMH and Inhibin B was observed, but only in the age groups GW 7-10 and 10-12, while a decrease in the total density of germ cells and OCT4⁺ gonocytes was found in the GW 7-10 age group. Flutamide treatment in specimens aged GW 7-12 did not alter androgen production, but the secretion of INSL3, AMH and Inhibin B was reduced, and a reduced number of pre-spermatogonia was observed.

CONCLUSIONS

This study showed that reduced androgen action during early development affects the function and density of several cell types in the human fetal testis, with similar effects observed after ketoconazole and flutamide treatment. The effects were only observed within the GW 7-14 period-thereby indicating the presence of a window of androgen sensitivity in the human fetal testis.

Developmental origins of adult diseases

The occurrence and mechanisms of developmental adult diseases have gradually attracted attention in recent years. Exposure of gametes and embryos to adverse environments, especially during plastic development, can alter the expression of certain tissue-specific genes, leading to increased susceptibility to certain diseases in adulthood, such as diabetes, cardiovascular disease, neuropsychiatric, and reproductive system diseases, etc. The occurrence of chronic disease in adulthood is partly due to genetic factors, and the remaining risk is partly due to environmental-dependent epigenetic information alteration, including DNA methylation, histone modifications, and noncoding RNAs. Changes in this epigenetic information potentially damage our health, which has also been supported by numerous epidemiological and animal studies in recent years. Environmental factors functionally affect embryo development through epimutation, transmitting diseases to offspring and even later generations. This review mainly elaborated on the concept of developmental origins of adult diseases, and revealed the epigenetic mechanisms underlying these events, discussed the theoretical basis for the prevention and treatment of related diseases.

Expression of G-Protein-Coupled Estrogen Receptor (GPER) in Whole Testicular Tissue and Laser-Capture Microdissected Testicular Compartments of Men with Normal and Aberrant Spermatogenesis

Simple Summary

Nowadays, there is no doubt that estrogens play an important role in male reproduction, affecting testicular cell differentiation, proliferation, apoptosis and metabolism. It is also widely believed that intratesticular balance of androgens and estrogens is crucial for the testicular development and function and that the increased testicular estrogen production may be associated with spermatogenic failure. There is also growing epidemiological evidence that the exposure of men to endocrine disruptors demonstrating estrogenic activity (xenoestrogens) may lead to impairment of male fertility via interference with estrogen signaling pathways. Besides the two classical nuclear estrogen receptors, the membrane-bound G protein-coupled estrogen receptor (GPER) was described in human testicular tissue. However, there are little data on its expression in testes with disturbed spermatogenesis. In this study, we investigated the GPER expression pattern in biopsies of azoospermic men with complete and aberrant spermatogenesis. Our results showed an increased expression of the GPER in testes with impaired spermatogenesis. Moreover, they indicate a possible involvement of estrogen signaling through GPER in disturbed function of Sertoli cells—the cells that support spermatogenic process.

Abstract

In this study, we retrospectively investigated GPER expression in biopsies of azoospermic men with complete (obstructive azoospermia—OA) and aberrant spermatogenesis (nonobstructive azoospermia—NOA). Each biopsy was histologically evaluated with morphometry. The testicular GPER expression was analyzed by the immunohistochemistry and RT-PCR technique in the whole testicular tissue and in seminiferous tubules and Leydig cells after laser-capture microdissection. In laser-microdissected compartments, we also analyzed transcriptional expression of selected Leydig (CYP17A1, HSD17B3, StAR) and Sertoli cell (AMH, SCF, BMP4) function markers. Immunohistochemical staining revealed expression of GPER in the cytoplasm of Leydig and Sertoli cells. Its stronger intensity was observed in Sertoli cells of NOA biopsies. The RT-PCR analysis of the GPER mRNA level unequivocally showed its increased expression in seminiferous tubules (i.e., Sertoli cells), not Leydig cells in NOA biopsies. This increased expression correlated positively with the transcriptional level of AMH—a marker of Sertoli cell immaturity, as well as FSH serum level in NOA but not in the OA group. Our results clearly demonstrate altered GPER expression in testes with primary spermatogenic impairment that might be related to Sertoli cell maturity/function.

Intrauterine hyponutrition reduces fetal testosterone production and postnatal sperm count in the mouse

Although intrauterine hyponutrition is regarded as a risk factor for the development of "testicular dysgenesis syndrome" (TDS) in the human, underlying mechanism(s) remain largely unknown. To clarify the underlying mechanism(s), we fed vaginal plug-positive C57BL/6N female mice with regular food ad libitum throughout the pregnant course (control females) (C-females) or with 50% of the mean daily intake of the C-females from 6.5 dpc (calorie-restricted females) (R-females), and compared male reproductive findings between 17.5-dpc-old male mice delivered from C-females (C-fetuses) and those delivered from R-females (R-fetuses) and between 6-week-old male mice born to C-females (C-offspring) and those born to R-females (R-offspring). Compared with the C-fetuses, the R-fetuses had (1) morphologically normal external genitalia with significantly reduced anogenital distance index, (2) normal numbers of testicular component cells, and (3) significantly low intratesticular testosterone, in association with significantly reduced expressions of steroidogenic genes. Furthermore, compared with the C-offspring, the R-offspring had (1) significantly increased TUNEL-positive cells and normal numbers of other testicular component cells, (2) normal intratesticular testosterone, in association with normal expressions of steroidogenic genes, (3) significantly reduced sperm count, and normal testis weight and sperm motility, and (4) significantly altered expressions of oxidation stress-related, apoptosis-related, and spermatogenesis-related genes. The results, together with the previous data including the association between testosterone deprivation and oxidative stress-evoked apoptotic activation, imply that reduced fetal testosterone production is the primary underlying factor for the development of TDS in intrauterine hyponutrition, and that TDS is included in the clinical spectrum of Developmental Origins of Health and Disease.

Society for Endocrinology guidelines for testosterone replacement therapy in male hypogonadism

Male hypogonadism (MH) is a common endocrine disorder. However, uncertainties and variations in its diagnosis and management exist. There are several current guidelines on testosterone replacement therapy that have been driven predominantly by single disciplines. The Society for Endocrinology commissioned this new guideline to provide all care providers with a multidisciplinary approach to treating patients with MH. This guideline has been compiled using expertise from endocrine (medical and nursing), primary care, clinical biochemistry, urology and reproductive medicine practices. These guidelines also provide a patient perspective to help clinicians best manage MH.

A case-cohort study of perinatal exposure to potential endocrine disrupters and the risk of cryptorchidism in the Norwegian HUMIS study

BACKGROUND

Exposure to endocrine-disrupting chemicals (EDCs) during the critical period of testicular descent may increase the risk of cryptorchidism and male fertility.

OBJECTIVE

To investigate 27 potential EDCs measured in breast milk as a proxy for perinatal exposure and the risk of cryptorchidism in a prospective cohort.

METHOD

The Norwegian Human Milk Study (2002-2009) enrolled 2606 mother-infant pairs, of which 1326 were mother-son pairs. In a case-cohort design, we studied 641 male infants who had 27 EDCs already quantified in milk samples: 5 organochlorine pesticides, 14 polychlorinated biphenyls (PCBs), 6 brominated flame retardants, and 2 poly- and perfluoroalkyl substances. We defined cases of congenital, recurrent, persistent and ever-reported cryptorchidism based on questionnaires mothers completed when children were 1, 6, 12 and 24 months old. Variable selection via elastic net logistic regression identified the best cryptorchidism predictors while multivariable logistic regression models determined their effect estimates.

RESULTS

The prevalence of reported congenital cryptorchidism was 6.1%, with half spontaneously descending within six months of birth, after which prevalence stabilized between 2.2 and 2.4%. The ever-reported prevalence of cryptorchidism at 1, 6, 12, or 24 months was 12.2%. Elastic net models identified PCB-74 (OR = 1.31, 95% CI: 1.001-1.703), PCB-114 (OR = 1.36, 95% CI: 1.05-1.77), PCB-194 (OR = 1.28, 95% CI: 1.03-1.53) and β-HCH (OR = 1.26, 95% CI: 1.03-1.53 (per interquartile range increase in concentration of EDCs) as best predictors of congenital cryptorchidism. No EDCs were selected for either recurrent or persistent cryptorchidism, and only PCB-194 was selected by elastic net for ever-reported cryptorchidism (OR = 1.23, 95% CI: 1.01-1.51), in contrast to unpenalized multivariable logistic regression, where most of the individual congeners of PCBs showed significant associations.

CONCLUSION

In the largest multi-pollutant analysis to date considering potential confounding from co-exposure to other chemicals, perinatal exposure to PCB-74, PCB-114, PCB-194 and β-HCH were associated with increased odds of congenital cryptorchidism. Many PCBs may falsely be associated with cryptorchidism when assessed individually, due to confounding by highly correlated chemicals. Experimental studies are warranted to confirm our findings.

Nutritional Regulation of Embryonic Survival, Growth, and Development

Maternal nutritional status affects conceptus development and, therefore, embryonic survival, growth, and development. These effects are apparent very early in pregnancy, which is when most embryonic losses occur. Maternal nutritional status has been shown to affect conceptus growth and gene expression throughout the periconceptual period of pregnancy (the period immediately before and after conception). Thus, the periconceptual period may be an important "window" during which the structure and function of the fetus and the placenta are "programmed" by stressors such as maternal malnutrition, which can have long-term consequences for the health and well-being of the offspring, a concept often referred to as Developmental Origins of Health and Disease (DOHaD) or simply developmental programming. In this review, we focus on recent studies, using primarily animal models, to examine the effects of various maternal "stressors," but especially maternal malnutrition and Assisted Reproductive Techniques (ART, including in vitro fertilization, cloning, and embryo transfer), during the periconceptual period of pregnancy on conceptus survival, growth, and development. We also examine the underlying mechanisms that have been uncovered in these recent studies, such as effects on the development of both the placenta and fetal organs. We conclude with our view of future research directions in this critical area of investigation.

Sonographic evaluation of fetal scrotum, testes and epididymis

External male genitalia have rarely been evaluated on fetal ultrasound. Apart from visualization of the penis for fetal sex determination, there are no specific instructions or recommendations from scientific societies. This study aimed to review the current knowledge about prenatal diagnosis of the scrotum and internal structures, with discussion regarding technical aspects and clinical management. We conducted an article search in Medline, EMBASE, Scopus, Google Scholar, and Web of Science databases for studies in English or Spanish language that discussed prenatal scrotal pathologies. We identified 72 studies that met the inclusion criteria. Relevant data were grouped into sections of embryology, ultrasound, pathology, and prenatal diagnosis. The scrotum and internal structures show a wide range of pathologies, with varying degrees of prevalence and morbidity. Most of the reported cases have described incidental findings diagnosed via striking ultrasound signs. Studies discussing normative data or management are scarce.

EDCs and male urogenital cancers

Male sex determination and sexual differentiation occur between 6-12 weeks of gestation. During the "male programming window" the fetal testes start to produce testosterone that initiates the development of the male reproductive tract. Exposure to endocrine disrupting chemicals (EDCs) able to mimic or disrupt steroid hormone actions may disrupt testicular development and adversely impact reproductive health at birth, during puberty and adulthood. The testicular dysgenesis syndrome (TDS) occurs as a result inhibition of androgen action on fetal development preceding Sertoli and Leydig cell dysfunction and may result from direct or epigenetic effects. Hypospadias, cryptorchidism and poor semen quality are elements of TDS, which may be considered a risk factor for testicular germ cell cancer (TGCC). Exposure to estrogen or estrogenic EDCs results in developmental estrogenization/estrogen imprinting in the rodent for prostate cancer (PCa). This can disrupt prostate histology by disorganization of the epithelium, prostatic intraepithelial neoplasia (PIN) lesions, in particular high-grade PIN (HGPIN) lesions which are precursors of prostatic adenocarcinoma. These defects persist throughout the lifespan of the animal and later in life estrogen exposure predispose development of cancer. Exposure of pregnant dams to vinclozolin, a competitive anti-androgen, and results in prominent, focal regions of inflammation in all exposed animals. The inflammation closely resembles human nonbacterial prostatitis that occurs in young men and evidence indicates that inflammation plays a central role in the development of PCa. In conclusion, in utero exposure to endocrine disrupters may predispose to the development of TDS, testicular cancer (TCa) and PCa and are illustrations of Developmental Origins of Health and Disease (DOHaD).

Effect and in silico characterization of genetic variants associated with severe spermatogenic disorders in a large Iberian cohort

BACKGROUND

Severe spermatogenic failure (SpF) represents the most extreme manifestation of male infertility, as it decreases drastically the semen quality leading to either severe oligospermia (SO, <5 million spermatozoa/mL semen) or non-obstructive azoospermia (NOA, complete lack of spermatozoa in the ejaculate without obstructive causes).

OBJECTIVES

The main objective of the present study is to analyze in the Iberian population the effect of 6 single-nucleotide polymorphisms (SNPs) previously associated with NOA in Han Chinese through genome-wide association studies (GWAS) and to establish their possible functional relevance in the development of specific SpF patterns.

MATERIALS AND METHODS

We genotyped 674 Iberian infertile men (including 480 NOA and 194 SO patients) and 1058 matched unaffected controls for the GWAS-associated variants PRMT6-rs12097821, PEX10-rs2477686, CDC42BPA-rs3000811, IL17A-rs13206743, ABLIM1-rs7099208, and SOX5-rs10842262. Their association with SpF, SO, NOA, and different NOA phenotypes was evaluated by logistic regression models, and their functional relevance was defined by comprehensive interrogation of public resources.

RESULTS

ABLIM1-rs7099208 was associated with SpF under both additive (OR = 0.86, p = 0.036) and dominant models (OR = 0.78, p = 0.026). The CDC42BPA-rs3000811 minor allele frequency was significantly increased in the subgroup of NOA patients showing maturation arrest (MA) of germ cells compared to the remaining NOA cases under the recessive model (OR = 4.45, p = 0.044). The PEX10-rs2477686 SNP was associated with a negative testicular sperm extraction (TESE) outcome under the additive model (OR = 1.32, p = 0.034). The analysis of functional annotations suggested that these variants affect the testis-specific expression of nearby genes and that lincRNA may play a role in SpF.

CONCLUSIONS

Our data support the association of three previously reported NOA risk variants in Asians (ABLIM1-rs7099208, CDC42BPA-rs3000811, and PEX10-rs2477686) with different manifestations of SpF in Iberians of European descent, likely by influencing gene expression and lincRNA deregulation.

Classical toxicity endpoints in female rats are insensitive to the human endocrine disruptors diethylstilbestrol and ketoconazole

Developmental exposure to endocrine disrupting chemicals can have negative consequences for reproductive health in both men and women. Our knowledge about how chemicals can cause adverse health outcomes in females is, however, poorer than our knowledge in males. This is possibly due to lack of sensitive endpoints to evaluate endocrine disruption potential in toxicity studies. To address this shortcoming we carried out rat studies with two well-known human endocrine disruptors, diethylstilbestrol (DES) and ketoconazole (KTZ), and evaluated the sensitivity of a series of endocrine related endpoints. Sprague-Dawley rats were exposed orally from gestational day 7 until postnatal day 22. In a range-finding study, disruption of pregnancy-related endpoints was seen from 0.014 mg/kg bw/day for DES and 14 mg/kg bw/day for KTZ, so doses were adjusted to 0.003; 0.006; and 0.0012 mg/kg bw/day DES and 3; 6; or 12 mg/kg bw/day KTZ in the main study. We observed endocrine disrupting effects on sensitive endpoints in male offspring: both DES and KTZ shortened anogenital distance and increased nipple retention. In female offspring, 0.0012 mg/kg bw/day DES caused slightly longer anogenital distance. We did not see effects on puberty onset when comparing average day of vaginal opening; however, we saw a subtle delay after exposure to both chemicals using a time-curve analysis. No effects on estrous cycle were registered. Our study shows a need for more sensitive test methods to protect the reproductive health of girls and women from harmful chemicals.

A pilot study: Relationship between Bisphenol A, Bisphenol A glucuronide and sex steroid hormone levels in cord blood in A South African population

Exposure to Bisphenol A (BPA) during early development particularly in- utero has been linked to a wide range of pathology. The aim of this study was to examine the relationship of BPA and its naturally occurring metabolite BPA-glucuronide (BPA-g) with sex steroid hormone levels in South African mother-child pairs. Third-trimester serum maternal samples and matching cord blood samples were analyzed for BPA, BPA-g and nine sex steroid hormones using liquid chromatography tandem mass spectrometry (LC-MS/MS). Sixty maternal and child pairs were analyzed. Rank correlation demonstrated a significant positive relationship between cord blood estradiol and cord blood BPA (p = 0.002) and maternal BPA levels (p = 0.02) respectively. Cord blood testosterone from male infants showed a negative Spearman's correlation (r=-0.5, p = 0.02) with maternal BPA-g. There was no statistical difference in total testosterone levels in cord blood from male and female infants. The findings of the current study indicate a significant relationship between some key sex steroid hormones namely testosterone, dihydrotestosterone and estradiol and fetal exposure BPA.

Endocrine Disrupting Chemicals and Reproductive Health in Boys and Men

Male reproductive health has declined as indicated by increasing rates of cryptorchidism, i.e., undescended testis, poor semen quality, low serum testosterone level, and testicular cancer. Exposure to endocrine disrupting chemicals (EDCs) has been proposed to have a role in this finding. In utero exposure to antiandrogenic EDCs, particularly at a sensitive period of fetal testicular development, the so-called 'masculinization programming window (MPW)', can disturb testicular development and function. Low androgen effect during the MPW can cause both short- and long-term reproductive disorders. A concurrent exposure to EDCs may also affect testicular function or damage testicular cells. Evidence from animal studies supports the role of endocrine disrupting chemicals in development of male reproductive disorders. However, evidence from epidemiological studies is relatively mixed. In this article, we review the current literature that evaluated relationship between prenatal EDC exposures and anogenital distance, cryptorchidism, and congenital penile abnormality called hypospadias. We review also studies on the association between early life and postnatal EDC exposure and semen quality, hypothalamic-pituitary-gonadal axis hormone levels and testicular cancer.

FSHB and FSHR gene variants exert mild modulatory effect on reproductive hormone levels and testis size but not on semen quality: A study of 2020 men from the general Danish population

BACKGROUND

Spermatogenesis depends on stimulation by follicle-stimulating hormone (FSH) which binds to FSH receptors (FSHR) on testicular Sertoli cells. Three FSH-related single-nucleotide polymorphisms (SNPs), FSHB -211G>T (rs10835638), FSHR -29G>A (rs1394205) and FSHR 2039A>G (rs6166) affect FSH action, and have been suggested to affect testicular function, but the evidence is uncertain.

OBJECTIVE

To describe the associations between the three SNPs and testicular function in a large and well-characterised cohort of men from the general population.

MATERIALS AND METHODS

A cross-sectional study of 2020 Danish men unselected regarding testicular function. Outcome variables were semen parameters, reproductive hormones and testis size. Genotyping was done by competitive allele-specific quantitative PCR. Differences in genotype frequencies were tested by chi-square test and associations between genotypes and outcomes were assessed by multivariate linear regressions.

RESULTS

The SNPs affected serum FSH; carriers of the variant affecting FSH secretion (FSHB -211G>T) had lower FSH levels while carriers of variants affecting receptor expression (FSHR -29G>A) and receptor sensitivity (FSHR 2039A>G) had higher FSH levels. Carriers of FSHB -211G>T had lower calculated free testosterone/LH ratio. Although both FSHB -211G>T and FSHR 2039A>G were associated with smaller testis size, no clear association was detected in relation to any semen parameters, except a lower total number of morphologically normal spermatozoa in the heterozygous carriers of the FSHB -211G>T DISCUSSION AND CONCLUSION: The studied polymorphisms have only minor modulating influence on testis size and function in healthy men. We detected subtle effects of the three SNPs on FSH levels, but also effects of FSHB -211G>T on calculated free testosterone/LH ratio, compatible with altered Leydig cell function. Thus, the role of these FSH-related polymorphisms is complex and modest in men with normal testicular function, but the possible importance of FSH polymorphisms in men with impaired testicular function should be evaluated in future studies in more detail.

Quantitative in Vitro to in Vivo Extrapolation (QIVIVE) for Predicting Reduced Anogenital Distance Produced by Anti-Androgenic Pesticides in a Rodent Model for Male Reproductive Disorders

BACKGROUND

Many pesticides can antagonize the androgen receptor (AR) or inhibit androgen synthesis in vitro but their potential to cause reproductive toxicity related to disruption of androgen action during fetal life is difficult to predict. Currently no approaches for using in vitro data to anticipate such in vivo effects exist. Prioritization schemes that limit unnecessary in vivo testing are urgently needed.

OBJECTIVES

The aim was to develop a quantitative in vitro to in vivo extrapolation (QIVIVE) approach for predicting in vivo anti-androgenicity arising from gestational exposures and manifesting as a shortened anogenital distance (AGD) in male rats.

METHODS

We built a physiologically based pharmacokinetic (PBK) model to simulate concentrations of chemicals in the fetus resulting from maternal dosing. The predicted fetal levels were compared with analytically determined concentrations, and these were judged against in vitro active concentrations for AR antagonism and androgen synthesis suppression.

RESULTS

We first evaluated our model by using in vitro and in vivo anti-androgenic data for procymidone, vinclozolin, and linuron. Our PBK model described the measured fetal concentrations of parent compounds and metabolites quite accurately (within a factor of five). We applied the model to nine current-use pesticides, all with in vitro evidence for anti-androgenicity but missing in vivo data. Seven pesticides (fludioxonil, cyprodinil, dimethomorph, imazalil, quinoxyfen, fenhexamid, o -phenylphenol) were predicted to produce a shortened AGD in male pups, whereas two (λ -cyhalothrin , pyrimethanil) were anticipated to be inactive. We tested these expectations for fludioxonil, cyprodinil, and dimethomorph and observed shortened AGD in male pups after gestational exposure. The measured fetal concentrations agreed well with PBK-modeled predictions.

DISCUSSION

Our QIVIVE model newly identified fludioxonil, cyprodinil, and dimethomorph as in vivo anti-androgens. With the examples investigated, our approach shows great promise for predicting in vivo anti-androgenicity (i.e., AGD shortening) for chemicals with in vitro activity and for minimizing unnecessary in vivo testing. https://doi.org/10.1289/EHP6774.

Regional difference in semen quality of young men: a review on the implication of environmental and lifestyle factors during fetal life and adulthood

The prevalence of low semen quality and the incidence of testicular cancer have been steadily increasing over the past decades in different parts of the World. Although these conditions may have a genetic or epigenetic origin, there is growing evidence that multiple environmental and lifestyle factors can act alone or in combination to induce adverse effects. Exposure to these factors may occur as early as during fetal life, via the mother, and directly throughout adulthood after full spermatogenic capacity is reached. This review aims at providing an overview of past and current trends in semen quality and its relevance to fertility as well as a barometer of men’s general health. The focus will be on recent epidemiological studies of young men from the general population highlighting geographic variations in Europe. The impact of some lifestyle and environmental factors will be discussed with their role in both fetal life and adulthood. These factors include smoking, alcohol consumption, psychological stress, exposure to electromagnetic radiation, and Endocrine Disrupting Chemicals (EDCs). Finally, the challenges in investigating the influence of environmental factors on semen quality in a fast changing world are presented.

Anogenital Distance in Healthy Infants: Method-, Age- and Sex-related Reference Ranges

CONTEXT

The use of anogenital distance (AGD) in clinical and epidemiological settings is increasing; however, sex-specific reference data on AGD and data on longitudinal changes in AGD in children is scarce.

OBJECTIVE

To create age-, sex-, and method-related reference ranges of AGD in healthy boys and girls aged 0-24 months, to assess the age-related changes in AGD and to evaluate the 2 predominantly used methods of AGD measurement.

DESIGN

The International AGD consortium comprising 4 centers compiled data from 1 cross-sectional and 3 longitudinal cohort studies (clinicaltrials.gov [NCT02497209]).

SETTING

All data were collected from population-based studies, recruiting from 4 maternity or obstetric centers (United States, Cambridge [United Kingdom], Odense, and Copenhagen [Denmark]).

SUBJECTS

This study included a total of 3705 healthy, mainly Caucasian children aged 0-24 months on whom 7295 measurements were recorded.

MAIN OUTCOME MEASURES

AGDAS (ano-scrotal), AGDAF (ano-fourchette), AGDAP (ano-penile), AGDAC (ano-clitoral), AGD body size indices (weight, body mass index [BMI], body surface area, and length), and intra- and interobserver biases.

RESULTS

We created age-specific reference ranges by centers. We found that AGD increased from birth to 6 months of age and thereafter reached a plateau. Changes in AGD/BMI during the first year of life were minor (0-6% and 0-11% in boys and girls, respectively).

CONCLUSIONS

Reference ranges for AGD can be used in future epidemiological research and may be utilized clinically to evaluate prenatal androgen action in differences-in-sex-development patients. The increase in AGD during the first year of life was age-related, while AGD/BMI was fairly stable. The TIDES and Cambridge methods were equally reproducible.

Androgens During Infancy, Childhood, and Adolescence: Physiology and Use in Clinical Practice

We provide an in-depth review of the role of androgens in male maturation and development, from the fetal stage through adolescence into emerging adulthood, and discuss the treatment of disorders of androgen production throughout these time periods. Testosterone, the primary androgen produced by males, has both anabolic and androgenic effects. Androgen exposure induces virilization and anabolic body composition changes during fetal development, influences growth and virilization during infancy, and stimulates development of secondary sexual characteristics, growth acceleration, bone mass accrual, and alterations of body composition during puberty. Disorders of androgen production may be subdivided into hypo- or hypergonadotropic hypogonadism. Hypogonadotropic hypogonadism may be either congenital or acquired (resulting from cranial radiation, trauma, or less common causes). Hypergonadotropic hypogonadism occurs in males with Klinefelter syndrome and may occur in response to pelvic radiation, certain chemotherapeutic agents, and less common causes. These disorders all require testosterone replacement therapy during pubertal maturation and many require lifelong replacement. Androgen (or gonadotropin) therapy is clearly beneficial in those with persistent hypogonadism and self-limited delayed puberty and is now widely used in transgender male adolescents. With more widespread use and newer formulations approved for adults, data from long-term randomized placebo-controlled trials are needed to enable pediatricians to identify the optimal age of initiation, route of administration, and dosing frequency to address the unique needs of their patients.

Human amniotic fluid-based exposure levels of phthalates and bisphenol A mixture reduce INSL3/RXFP2 signaling

BACKGROUND

The presence of chemical pollutants in the environment can affect human health. Epidemiological and in vivo experimental studies reveal reprotoxic effects (undescended testis) of phthalates (diethylhexyl phthalate (DEHP), dibutyl phthalate (DBP)) and bisphenol A (BPA), resulting in particular of a decrease in INSL3 (Insulin-Like 3 peptide) production. This hormone is essential for normal testis development and acts on a G protein-coupled receptor: RXFP2.

OBJECTIVES

The aim of this study was to evaluate the individual and combined impacts of DEHP, DBP, and BPA on human RXFP2 (hRXFP2) activity.

METHODS

We used HEK293 cells transiently transfected with hRXFP2 and receptor activity was analyzed by measuring intracellular cAMP production. The mixture was established at concentrations reported in human amniotic fluid, for the three compounds.

RESULTS

Individually, DEHP, DBP and BPA increased the response to INSL3 by 19.3 to 27.5%. This potentiating effect was specific for RXFP2, because it was absent in the cells which did not express this receptor. On the other hand, and interestingly, the mixture of the three compounds reduced significantly the response to INSL3 by 12%, and the observed effects were opposite to those predicted, suggesting an antagonist effect.

DISCUSSION-CONCLUSION

Taken together, our results demonstrate for the first time that a mixture of phthalates and BPA present in human amniotic fluid disturbs the human RXFP2 function. Moreover, we demonstrate that mixture can produce potential antagonistic effects that are not displayed by the compounds, individually.

Psychological stress, stressful life events, male factor infertility, and testicular function: a cross-sectional study

OBJECTIVE

To assess the association between psychological stress and male factor infertility as well as testicular function (semen quality, serum reproductive hormones) and erectile dysfunction.

DESIGN

Cross-sectional study.

SETTING

University Hospital-based research center.

PATIENTS

Men with impaired semen quality were included from infertile couples, and men with naturally conceived pregnant partners were used as a reference population.

INTERVENTIONS

Participants completed a questionnaire on health and lifestyle, including a 14-item questionnaire about self-rated psychological stress symptoms and stressful life event (SLEs), had a physical examination performed, delivered a semen sample and had a blood sample drawn.

MAIN OUTCOMES

Differences in stress scores (calculated from self-reported stress symptoms) and SLEs between infertile and fertile men were assessed in crude and fully adjusted linear regression models. Secondary outcomes were semen quality, serum reproductive hormones, and erectile dysfunction.

RESULTS

Of 423 men, 176 (41.6%) experienced at least one SLE in the 3 months prior to inclusion (50.4%/36.9%: infertile/fertile men, P = .03); β-coefficient and 95% confidence interval for the difference between the groups on the transformed scale in fully adjusted linear regression models was 0.18 (0.06, 0.30). However, there were no differences in psychological stress symptoms between the two groups (β-coefficient and 95% confidence interval) on the transformed scale (0.14; -0.02, 0.30). No association between stress (self-reported stress symptoms and SLEs) and testicular function or with erectile dysfunction was found in any of the men.

CONCLUSION

Infertile men reported a higher number of SLEs than fertile men but did not report more psychological stress symptoms. Distress and SLEs were not associated with reduced male reproductive function.

Prenatal organophosphate pesticide exposure and reproductive hormones in cord blood in Shandong, China

BACKGROUND

Organophosphate pesticides (OPs) have been found to be associated with endocrine disorders, but limited research has been conducted to evaluate the relationship between maternal OP exposure and fetal reproductive hormone levels. In this study, we investigated the association between prenatal OP exposure and fetal reproductive hormones.

METHODS

A total of 306 healthy pregnant women were enrolled between September 2010 and February 2012. Pesticide exposure was assessed via the analysis of maternal urinary nonspecific metabolites of OPs (dialkylphosphate, DAP), and four reproductive hormones were measured in cord blood. Linear regression models and generalized linear models were used to estimate the associations between DAP metabolites and reproductive hormones, and further stratified by infant sex.

RESULTS

We found that concentrations of diethylphosphate (DEP) (β = -0.03; 95% CI: -0.07, -0.00) were inversely associated with estradiol (E2). Dimethylphosphate (DMP) (β = -0.08; 95% CI: -0.13, -0.03), diethylthiophosphate (DETP) (β = -0.08; 95% CI: -0.14, -0.01), and DAPs (β = -0.10; 95% CI: -0.17, -0.03) were inversely associated with testosterone (T) levels. DMP was inversely associated with follicle-stimulating hormone (FSH) levels (β = -0.03; 95% CI: -0.05, -0.01). DMP (β = -0.06; 95% CI: -0.10, -0.01) and DETP (β = -0.07; 95% CI: -0.13, -0.01) showed inverse associations with the testosterone/estradiol (T/E2) ratio. Moreover, the magnitude of associations notably increased in higher quartiles of concentrations in a dose-response manner. After stratification by sex, these effects were mainly observed among female infants.

CONCLUSION

Our findings suggest the potential impacts of prenatal OP exposure on fetal reproductive hormones, and that sex-related differences may exist.

Male Hypogonadism and Disorders of Sex Development

Disorders of Sex Development (DSD) are congenital anomalies in which there is a discordance between chromosomal, genetic, gonadal, and/or internal/external genital sex. In XY individuals, the process of fetal sex differentiation can be disrupted at the stage of gonadal differentiation, resulting in gonadal dysgenesis, a form of early fetal-onset primary hypogonadism characterized by insufficient androgen and anti-Müllerian hormone (AMH) production, which leads to the development of ambiguous or female genitalia. The process of sex differentiation can also be disrupted at the stage of genital differentiation, due to isolated defects in androgen or AMH secretion, but not both. These are forms of fetal-onset hypogonadism with dissociated gonadal dysfunction. In this review, we present a perspective on impaired testicular endocrine function, i.e., fetal-onset male hypogonadism, resulting in incomplete virilization at birth.

The current status and future of andrology: A consensus report from the Cairo workshop group

BACKGROUND

In attempting to formulate potential WHO guidelines for the diagnosis of male infertility, the Evidence Synthesis Group noted a paucity of high-quality data on which to base key recommendations. As a result, a number of authors suggested that key areas of research/evidence gaps should be identified, so that appropriate funding and policy actions could be undertaken to help address key questions.

OBJECTIVES

The overall objective of this Consensus workshop was to clarify current knowledge and deficits in clinical laboratory andrology, so that clear paths for future development could be navigated.

MATERIALS AND METHODS

Following a detailed literature review, each author, prior to the face-to-face meeting, prepared a summary of their topic and submitted a PowerPoint presentation. The topics covered were (a) Diagnostic testing in male fertility and infertility, (b) Male fertility/infertility in the modern world, (c) Clinical management of male infertility, and (d) The overuse of ICSI. At the meeting in Cairo on February 18, 2019, the evidence was presented and discussed and a series of consensus points agreed.

RESULTS

The paper presents a background and summary of the evidence relating to these four topics and addresses key points of significance. Following discussion of the evidence, a total of 36 consensus points were agreed.

DISCUSSION

The Discussion section presents areas where there was further debate and key areas that were highlighted during the day.

CONCLUSION

The consensus points provide clear statements of evidence gaps and/or potential future research areas/topics. Appropriate funding streams addressing these can be prioritized and consequently, in the short and medium term, answers provided. By using this strategic approach, andrology can make the rapid progress necessary to address key scientific, clinical, and societal challenges that face our discipline now and in the near future.

Development of fetal and adult Leydig cells

BACKGROUND

In mammals, two distinct Leydig cell populations, fetal Leydig cells (FLCs) and adult Leydig cells (ALCs), appear in the prenatal and postnatal testis, respectively. Although the functional differences between these cell types have been well described, the developmental relationship between FLCs and ALCs has not been fully understood. In this review, I focus on the cellular origins of FLCs and ALCs as well as the developmental and functional links between them.

METHODS

I surveyed previous reports about FLC and/or ALC development and summarized the findings.

MAIN FINDINGS

Fetal Leydig cells and ALCs were identified to have separate origins in the fetal and neonatal testis, respectively. However, several studies suggested that FLCs and ALCs share a common progenitor pool. Moreover, perturbation of FLC development at the fetal stage induces ALC dysfunction in adults, suggesting a functional link between FLCs and ALCs. Although the lineage relationship between FLCs and ALCs remains controversial, a recent study suggested that some FLCs dedifferentiate at the fetal stage, and that these cells serve as ALC stem cells.

CONCLUSION

Findings obtained from animal studies might provide clues to the causative mechanisms of male reproductive dysfunctions such as testicular dysgenesis syndrome in humans.

Novel combined insulin-like 3 variations of a single nucleotide in cryptorchidism

Background Insulin-like 3 hormone (INSL3) is involved in the process of testicular descent, and has been thoroughly studied in cryptorchidism. However, INSL3 allelic variations found in the human genome were heterozygous and only a few of them were found exclusively in patients with cryptorchidism. Under this perspective, we aimed to study the presence of INSL3 allelic variations in a cohort of patients with cryptorchidism and to estimate their potential consequences. Methods Blood samples were collected from 46 male patients with non-syndromic cryptorchidism and from 43 age-matched controls. DNA extraction and polymerase chain reaction (PCR) were performed for exons 1 and 2 of the INSL3 gene in all subjects. Sequencing analysis was carried out on the PCR products. All data were grouped according to testicular location. Results Seven variations of a single nucleotide (SNVs) were identified both in patients with cryptorchidism and in controls: rs2286663 (c.27G > A), rs1047233 (c.126A > G) and rs6523 (c.178A > G) at exon 1, rs74531687 (c.191-30C > T) at the intron, rs121912556 (c.305G > A) at exon 2 and rs17750642 (c.*101C > A) and rs1003887 (c.*263G > A) at the untranslated region (UTR). The allelic variants rs74531687 and rs121912556 were found for the first time in the Greek population. The novel homozygotic combination of the three allelic variants rs1047233-rs6523-rs1003887 seemed to present a stronger correlation with more severe forms of cryptorchidism. Conclusions The combination of specific INSL3 SNVs rather than the existence of each one of them alone may offer a new insight into the involvement of allelic variants in phenotypic variability and severity.

The effects of perfluorooctanoic acid (PFOA) on fetal and adult rat testis

Perfluorooctanoic acid (PFOA) is a widely dispersed synthetic chemical, which accumulates in living organisms and has been connected with male reproductive disorders. To monitor the effects of PFOA, fetal rat testes or seminiferous tubule segments (stage VII-VIII) of adult rats were cultured in 0-100 μg/ml PFOA for 24 h. Afterwards, cAMP, progesterone, testosterone and StAR protein levels were measured from the fetal testes culture. Measurements were combined with immunohistochemistry, immunofluorescence, TUNEL and flow cytometric analysis to monitor cell death in somatic and germ cells. This study shows that the levels of cAMP, progesterone, testosterone and expression of StAR decreased significantly in PFOA 50 and 100 μg/ml. PFOA affected cell populations significantly by decreasing the amount of diploid, proliferating, meiotic I and G2/M-phase cells in adult rat testis. However, PFOA did not affect fetal, proliferating or adult rat Sertoli cells but an increased tendency of apoptosis in fetal Leydig cells was observed.

Timescales of developmental toxicity impacting on research and needs for intervention

Much progress has happened in understanding developmental vulnerability to preventable environmental hazards. Along with the improved insight, the perspective has widened, and developmental toxicity now involves latent effects that can result in delayed adverse effects in adults or at old age and additional effects that can be transgenerationally transferred to future generations. Although epidemiology and toxicology to an increasing degree are exploring the adverse effects from developmental exposures in human beings, the improved documentation has resulted in little progress in protection, and few environmental chemicals are currently regulated to protect against developmental toxicity, whether it be neurotoxicity, endocrine disruption or other adverse outcome. The desire to obtain a high degree of certainty and verification of the evidence used for decision-making must be weighed against the costs and necessary duration of research, as well as the long-term costs to human health because of delayed protection of vulnerable early-life stages of human development and, possibly, future generations. Although two-generation toxicology tests may be useful for initial test purposes, other rapidly emerging tools need to be seriously considered from computational chemistry and metabolomics to CLARITY-BPA-type designs, big data and population record linkage approaches that will allow efficient generation of new insight; epigenetic mechanisms may necessitate a set of additional regulatory tests to reveal such effects. As reflected by the Prenatal Programming and Toxicity (PPTOX) VI conference, the current scientific understanding and the timescales involved require an intensified approach to protect against preventable adverse health effects that can harm the next generation and generations to come. While further research is needed, the main emphasis should be on research translation and timely public health intervention to avoid serious, irreversible and perhaps transgenerational harm.

Cord blood Per- and polyfluoroalkyl substances, placental steroidogenic enzyme, and cord blood reproductive hormone

BACKGROUND

Per- and polyfluoroalkyl substances (PFASs) are widely used in China, but little is known about the association between prenatal PFASs exposure and fetal reproductive development as well as its potential mechanism.

OBJECTIVE

We investigated the effects of cord blood PFASs on fetal reproductive hormones and its potential mechanism in relation to steroidogenic enzymes.

METHODS

Ten selected PFASs (n = 351) including PFOS, PFOA, PFBS, PFDA, PFDoA, PFHpA, PFHxS, PFNA, PFOSA, and PFUA, and two reproductive hormones estradiol (E2) (n = 351) and testosterone (T) (n = 349) were measured in 351 cord blood serum samples from a Chinese birth cohort between 2010 and 2013. Three steroidogenic enzymes including P450arom (n = 125), 3β-HSD1 (n = 123), and 17β-HSD1 (n = 116) were measured in 125 placental tissue samples. Linear regression tested the associations between cord blood PFASs and reproductive hormones in cord blood. Mediation analysis assessed the role of placental steroidogenic enzymes between cord blood PFASs and reproductive hormones.

RESULTS

The positive associations between PFOA, PFHxS and E2 levels, PFOS, PFUA, PFNA and T levels, and PFOS, PFUA and T/E2 ratio were significant. PFUA, PFNA, PFDA, PFHxS, and ∑PFASs were associated with higher P450arom levels. PFHxS was also associated with increased 3β-HSD1 and 17β-HSD1 levels. These associations were more pronounced in females than males when stratified by gender. Furthermore, 17β-HSD1 demonstrated mediating effects in the positive association between cord blood PFHxS and E2 levels in females.

CONCLUSION

Our findings suggested the potential impacts of cord blood PFASs on fetal reproductive hormones, in which steroidogenic enzymes may play important roles. These associations were more pronounced in females than males.

Developmental Programming of Fetal Growth and Development

Maternal stressors that affect fetal development result in "developmental programming," which is associated with increased risk of various chronic pathologic conditions in the offspring, including metabolic syndrome; growth abnormalities; and reproductive, immune, behavioral, or cognitive dysfunction that can persist throughout their lifetime and even across subsequent generations. Developmental programming thus can lead to poor health, reduced longevity, and reduced productivity. Current research aims to develop management and therapeutic strategies to optimize fetal growth and development and thereby overcome the negative consequences of developmental programming, leading to improved health, longevity, and productivity of offspring.

Developmental kinetics and transcriptome dynamics of stem cell specification in the spermatogenic lineage

Continuity, robustness, and regeneration of cell lineages relies on stem cell pools that are established during development. For the mammalian spermatogenic lineage, a foundational spermatogonial stem cell (SSC) pool arises from prospermatogonial precursors during neonatal life via mechanisms that remain undefined. Here, we mapped the kinetics of this process in vivo using a multi-transgenic reporter mouse model, in silico with single-cell RNA sequencing, and functionally with transplantation analyses to define the SSC trajectory from prospermatogonia. Outcomes revealed that a heterogeneous prospermatogonial population undergoes dynamic changes during late fetal and neonatal development. Differential transcriptome profiles predicted divergent developmental trajectories from fetal prospermatogonia to descendant postnatal spermatogonia. Furthermore, transplantation analyses demonstrated that a defined subset of fetal prospermatogonia is fated to function as SSCs. Collectively, these findings suggest that SSC fate is preprogrammed within a subset of fetal prospermatogonia prior to building of the foundational pool during early neonatal development.

In neonatal testes, prospermatogonia generate both spermatogonia for the first wave of spermatogenesis and spermatogonial stem cells (SSCs) for maintenance of spermatogenesis in males. Here the authors characterize the development of mouse SSCs from prospermatogonia using single-cell RNA-seq and transplantation assays.

Water and soil pollution as determinant of water and food quality/contamination and its impact on male fertility

Over the past two decades, public health has focused on the identification of environmental chemical factors that are able to adversely affect hormonal function, known as endocrine disruptors (EDs). EDs mimic naturally occurring hormones like estrogens and androgens which can in turn interfere with the endocrine system. As a consequence, EDs affect human reproduction as well as post and pre-natal development. In fact, infants can be affected already at prenatal level due to maternal exposure to EDs. In particular, great attention has been given to those chemicals, or their metabolites, that have estrogenic properties or antagonistic effects on the activity of androgen or even inhibiting their production. These compounds have therefore the potential of interfering with important physiological processes, such as masculinization, morphological development of the urogenital system and secondary sexual traits. Animal and in vitro studies have supported the conclusion that endocrine-disrupting chemicals affect the hormone-dependent pathways responsible for male gonadal development, either through direct interaction with hormone receptors or via epigenetic and cell-cycle regulatory modes of action. In human populations, epidemiological studies have reported an overall decline of male fertility and an increased incidence of diseases or congenital malformations of the male reproductive system. The majority of studies point towards an association between exposure to EDs and male and/or female reproductive system disorders, such as infertility, endometriosis, breast cancer, testicular cancer, poor sperm quality and/or function. Despite promising discoveries, a causal relationship between the reproductive disorders and exposure to specific toxicants has yet to be established, due to the complexity of the clinical protocols used, the degree of occupational or environmental exposure, the determination of the variables measured and the sample size of the subjects examined. Despite the lack of consistency in the results of so many studies investigating endocrine-disrupting properties of many different classes of chemicals, the overall conclusion points toward a positive association between exposure to EDs and reproductive system. Future studies should focus on a uniform systems to examine human populations with regard to the exposure to specific EDs and the direct effect on the reproductive system.

Testicular Cancer: Genes, Environment, Hormones

Testicular cancer (TC) represents one of the most peculiar clinical challenges at present. In fact, currently treatments are so effective ensuring a 5 years disease-free survival rate in nearly 95% of patients. On the other hand however, TC represents the most frequent newly diagnosed form of cancer in men between the ages of 14 and 44 years, with an incidence ranging from <1 to 9.9 affected individuals per 100,000 males across countries, while the overall incidence is also increasing worldwide. Furthermore, cancer survivors show a 2% risk of developing cancer in the contralateral testis within 15 years of initial diagnosis. This complex and multifaceted scenario requires a great deal of effort to understand the clinical base of available evidence. It is now clear that genetic, environmental and hormonal risk factors concur and mutually influence both the development of the disease and its prognosis, in terms of response to treatment and the risk of recurrence. In this paper, the most recent issues describing the relative contribution of the aforementioned risk factors in TC development are discussed. In addition, particular attention is paid to the exposure to environmental chemical substances and thermal stress, whose role in cancer development and progression has recently been investigated at the molecular level.

In-utero Exposure to Maternal Stressful Life Events and Risk of Cryptorchidism: The Raine Study

Cryptorchidism, registered at birth or later, is the most common birth defect in males in western countries, estimated to affect around 2-3% of newborn boys, declining to around 2% at 3 months. We have previously described a potential association between stressful life events (SLEs) in pregnancy and reduced semen quality and testosterone levels in adult offspring. Both outcomes are believed to share a common etiology with cryptorchidism thus increased risk of cryptorchidism in boys exposed to prenatal SLEs may be plausible. The risk of cryptorchidism associated with prenatal SLE amongst 1,273 male Generation 2 offspring was estimated using the Western Australian Pregnancy (Raine) Study. SLEs are discrete experiences that disrupt an individual's usual activities causing a life change and readjustment, such as death of a relative or friend, divorce, illness or job loss. Mothers prospectively reported SLEs, during pregnancy at gestational weeks (GW) 18 and 34 using a standardized 10-point questionnaire. A boy was diagnosed as cryptorchid if one or both testes was non-palpable in the scrotum and not able to be manipulated into the scrotum. Twenty-four (2%) cryptorchid boys were identified. Mean (standard deviation) of SLE exposures in GW34 was 1.1 (1.2) for non-cryptorchid boys and slightly higher 1.5 (1.8) for cryptorchid boys, similar differences were observed in GW18. Adjusted odds ratio [OR] and 95% confidence intervals (CI) for risk of cryptorchidism in early (18-weeks) and late gestation (34-weeks) according to prenatal SLE exposures were: 1.06 (95% CI: 0.77-1.45) and 1.18 (95% CI: 0.84-1.67), respectively. This is the first-time report on the possible relationships between exposure to early and late pregnancy SLEs and risk of cryptorchidism in a birth cohort. Prenatal SLE exposure was not associated with a statistically significant increase in the risk of cryptorchidism in male offspring. A small case population limits the statistical power of the study and future larger studies are required to evaluate this potential association.

Hypogonadism and Cryptorchidism

Congenital cryptorchidism (undescended testis) is one of the most common congenital urogenital malformations in boys. Prevalence of cryptorchidism at birth among boys born with normal birth weight ranges from 1.8 to 8.4%. Cryptorchidism is associated with a risk of low semen quality and an increased risk of testicular germ cell tumors. Testicular hormones, androgens and insulin-like peptide 3 (INSL3), have an essential role in the process of testicular descent from intra-abdominal position into the scrotum in fetal life. This explains the increased prevalence of cryptorchidism among boys with diseases or syndromes associated with congenitally decreased secretion or action of androgens, such as patients with congenital hypogonadism and partial androgen insensitivity syndrome. There is evidence to support that cryptorchidism is associated with decreased testicular hormone production later in life. It has been shown that cryptorchidism impairs long-term Sertoli cell function, but may also affect Leydig cells. Germ cell loss taking place in the cryptorchid testis is proportional to the duration of the condition, and therefore early orchiopexy to bring the testis into the scrotum is the standard treatment. However, the evidence for benefits of early orchiopexy for testicular endocrine function is controversial. The hormonal treatments using human chorionic gonadotropin (hCG) or gonadotropin-releasing hormone (GnRH) to induce testicular descent have low success rates, and therefore they are not recommended by the current guidelines for management of cryptorchidism. However, more research is needed to assess the effects of hormonal treatments during infancy on future male reproductive health.