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

Genetic and genomic insights into male reproductive tract development

Genetic and genomic analysis continues to drive important insights into male reproductive tract (MRT) development. Here, we briefly review normal MRT development, highlighting recent discoveries of cell types and cellular processes delivered by single-cell sequencing. We report a systematic review of phenotype terms and genes linked to MRT development, identifying 35 terms from the Human Phenotype Ontology associated with 269 unique genes. A parallel review of mouse data revealed differences in the phenotype terms available and the number and identity of genes linked to MRT defects, indicating opportunities for harmonization of knowledge. We used a published single-cell atlas of the developing testis to characterize the regulation of MRT genes across cell types and stages of fetal testis development. Single-cell RNA sequencing data support the conclusion that Leydig cells and Sertoli cells are the primary testicular cell types expressing MRT genes. Furthermore, we find post-conception weeks 6, 8, and 16 to be the key points of upregulation of testicular MRT genes. New advances, especially in imaging and spatially resolved molecular measurements, provide exciting prospects for MRT research and diagnosis, and we expect rapid progress in the coming years. Continued investigation in this space is essential to understand the genetic basis of MRT development and how MRT defects are related to medical outcomes in adult life.

Prenatal exposure to organochlorine pesticides and polychlorinated biphenyls and risk of testicular germ cell cancer later in life

INTRODUCTION

Exposure to environmental chemicals during fetal development may increase the risk of testicular germ cell cancer (TGCC), but few studies have tested the hypothesis. We focused on organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), previously investigated in relation to other male reproductive health outcomes.

METHODS

We conducted a nested case-control study of 332 mother-son pairs, comprising 65 TGCC cases and 267 controls, identified from a Danish Pregnancy Screening Registry with biobanked serum samples collected from pregnant women in 1985-1995, when exposure to the studied chemicals was relatively high. We quantified seven OCPs and 13 PCB congeners in maternal serum by gas chromatography tandem mass spectrometry. TGCC diagnoses and covariate information were derived from the nationwide Danish registries. We estimated associations between individual chemicals and their mixture with the risk of TGCC through adapted Cox regression and quantile g-computation models.

RESULTS

Median age at TGCC diagnosis was 24.7 years. In main analyses, associations between individual OCPs and PCBs and risk of TGCC showed either slightly higher risks or no association (close to Hazard Ratios (HR) of 1.00), with confidence intervals overlapping unity. In mixture analyses, simultaneously increasing all chemical concentrations by one quartile resulted in a slightly higher risk of TGCC (HR 1.11, 95 % CI: 0.61; 2.05) after adjusting for confounders. Sensitivity analyses investigating tertiles of concentrations did not change the overall pattern of results.

CONCLUSIONS

Prenatal exposure to OCPs and PCBs, quantified by concentrations in maternal pregnancy serum, was not associated with later risk of TGCC.

Associations between maternal periconceptional exposure to PM2.5 and the risk of cryptorchidism: a case-control study of 4274

Currently, there is limited evidence regarding the association between prenatal exposure to environmental fine particulate matter (PM2.5) and the occurrence of cryptorchidism. The objective of this study was to evaluate the potential correlation between prenatal exposure to PM2.5 and the likelihood of cryptorchidism developing in offspring. We performed a 1:1 case-control study, defining the cases as children diagnosed with cryptorchidism at the Children's Hospital Affiliated to Chongqing Medical University from 2013 to 2017, while the control group comprised children born in the corresponding years who did not have any birth defects, chromosomal abnormalities, and had only trauma-related treatments. Between 2012 and 2017, monthly averages of PM2.5, other pollutants (O3, PM10) and temperature were gathered based on the geographical coordinates of patients' residences. The study assessed the correlation between the two using multivariate logistic regression model, and sensitivity analysis was conducted to assess the stability of the model. We included a total of 2137 cases and 2137 matched controls from 2013 to 2017. Our findings revealed that there was a positive association between exposure to PM2.5 during the first 2 months of pregnancy and the occurrence of cryptorchidism. According to this study, the development of cryptorchidism appears to be associated with maternal exposure to PM2.5 during early pregnancy.

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.

Hormone Regulation in Testicular Development and Function

The testes serve as the primary source of androgens and the site of spermatogenesis, with their development and function governed by hormonal actions via endocrine and paracrine pathways. Male fertility hinges on the availability of testosterone, a cornerstone of spermatogenesis, while follicle-stimulating hormone (FSH) signaling is indispensable for the proliferation, differentiation, and proper functioning of Sertoli and germ cells. This review covers the research on how androgens, FSH, and other hormones support processes crucial for male fertility in the testis and reproductive tract. These hormones are regulated by the hypothalamic-pituitary-gonad (HPG) axis, which is either quiescent or activated at different stages of the life course, and the regulation of the axis is crucial for the development and normal function of the male reproductive system. Hormonal imbalances, whether due to genetic predispositions or environmental influences, leading to hypogonadism or hypergonadism, can precipitate reproductive disorders. Investigating the regulatory network and molecular mechanisms involved in testicular development and spermatogenesis is instrumental in developing new therapeutic methods, drugs, and male hormonal contraceptives.

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.

The epidemiology of cryptorchidism and potential risk factors, including endocrine disrupting chemicals

Congenital cryptorchidism, also known as undescended testis, is the condition where one or both testes are not in place in the scrotum at birth and is one of the most common birth defects in boys. Temporal trends and geographic variation in the prevalence of cryptorchidism from 1% to 9% have been reported in prospective cohort studies. The testes develop in the abdominal cavity and descend to the scrotum in two phases, which should be completed by gestational week 35. Thus, the risk of cryptorchidism is higher in preterm boys. In many cases a spontaneous descent occurs during the first months of life during the surge of gonadotropins and testosterone. If not, the testis is usually brought down to the scrotum, typically by surgery, to increase future fertility chances and facilitate cancer surveillance. The increasing frequency of impaired semen quality and testicular cancer, with which cryptorchidism is associated, represents a concern for male reproductive health in general and a need to understand its risk factors. The risk of cryptorchidism is closely related to gestational factors (preterm birth, low birth weight and intrauterine growth restriction), and especially maternal smoking seems to be a risk factor. Evidence is accumulating that the increasing prevalence of cryptorchidism is also related to prenatal exposure to environmental chemicals, including endocrine disrupting compounds. This association has been corroborated in rodents and supported by ecological studies. Conducting human studies to assess the effect of endocrine disrupting chemicals and their interactions is, however, challenged by the widespread concomitant exposure of all humans to a wide range of chemicals, the combined effect of which and their interactions are highly complex.

Fetal Leydig cells: What we know and what we don't

During male fetal development, testosterone plays an essential role in the differentiation and maturation of the male reproductive system. Deficient fetal testosterone production can result in variations of sex differentiation that may cause infertility and even increased tumor incidence later in life. Fetal Leydig cells in the fetal testis are the major androgen source in mammals. Although fetal and adult Leydig cells are similar in their functions, they are two distinct cell types, and therefore, the knowledge of adult Leydig cells cannot be directly applied to understanding fetal Leydig cells. This review summarizes our current knowledge of fetal Leydig cells regarding their cell biology, developmental biology, and androgen production regulation in rodents and human. Fetal Leydig cells are present in basement membrane-enclosed clusters in between testis cords. They originate from the mesonephros mesenchyme and the coelomic epithelium and start to differentiate upon receiving a Desert Hedgehog signal from Sertoli cells or being released from a NOTCH signal from endothelial cells. Mature fetal Leydig cells produce androgens. Human fetal Leydig cell steroidogenesis is LHCGR (Luteinizing Hormone Chronic Gonadotropin Receptor) dependent, while rodents are not, although other Gαs -protein coupled receptors might be involved in rodent steroidogenesis regulation. Fetal steroidogenesis ceases after sex differentiation is completed, and some fetal Leydig cells dedifferentiate to serve as stem cells for adult testicular cell types. Significant gaps are acknowledged: (1) Why are adult and fetal Leydig cells different? (2) What are bona fide progenitor and fetal Leydig cell markers? (3) Which signaling pathways and transcription factors regulate fetal Leydig cell steroidogenesis? It is critical to discover answers to these questions so that we can understand vulnerable targets in fetal Leydig cells and the mechanisms for androgen production that when disrupted, leads to variations in sex differentiation that range from subtle to complete sex reversal.

Protective effect of selenium and vitamin C on the fertility of male rats given penconazole

OBJECTIVE

Penconazole is used in agriculture and human and veterinary medicine applications. It has been included in the acute toxicity hazard category by the WHO. This study examines the protective effect of selenium and vitamin C on the fertility of male rats given penconazole.

METHODS

Nine groups of rats were given penconazole at concentrations of 50 and 75 mg/ml and selenium and vitamin C at concentrations of 0.5 and 100 mg/ml, respectively. Serum levels of LH and FSH were measured with ELISA kits; β-actin, GPX4, AQP7, PRM2, and BAX gene expression was evaluated with real-time PCR performed on the left testis of each rat.

RESULTS

LH, FSH, and testosterone levels were lower in the groups given penconazole (50 and 75 mg/kg). Histopathology showed that the groups given penconazole had the lowest number of spermatogonia and primary spermatocytes; these numbers were greater in the groups receiving penconazole together with selenium or vitamin C; and the highest counts were observed in separate groups given Se and vitamin C. GPX4, AQP7, PRM2 and BAX gene expression in the groups receiving penconazole was different from controls and was modulated by treatment with selenium or vitamin C.

CONCLUSIONS

This study showed that antioxidant compounds have a strengthening effect on the reproductive system and can mitigate the destructive effects of chemical fungicides.