The "backdoor pathway" of androgen synthesis in human male sexual development

Hallmarks of sex bias in immuno-oncology: mechanisms and therapeutic implications

Sex differences are present across multiple non-reproductive organ cancers, with male individuals generally experiencing higher incidence of cancer with poorer outcomes. Although some mechanisms underlying these differences are emerging, the immunological basis is not well understood. Observations from clinical trials also suggest a sex bias in conventional immunotherapies with male individuals experiencing a more favourable response and female individuals experiencing more severe adverse events to immune checkpoint blockade. In this Perspective article, we summarize the major biological hallmarks underlying sex bias in immuno-oncology. We focus on signalling from sex hormones and chromosome-encoded gene products, along with sex hormone-independent and chromosome-independent epigenetic mechanisms in tumour and immune cells such as myeloid cells and T cells. Finally, we highlight opportunities for future studies on sex differences that integrate sex hormones and chromosomes and other emerging cancer hallmarks such as ageing and the microbiome to provide a more comprehensive view of how sex differences underlie the response in cancer that can be leveraged for more effective immuno-oncology approaches.

Determination of urinary androgens in women with polycystic ovary syndrome using LC-QqQ/MS and the application of thin film solid-phase microextraction (TF-SPME)

Hyperandrogenism is one of the most pronounced symptoms of Polycystic Ovary Syndrome (PCOS) and seems to play a key role in the pathogenesis of this complex disorder. Nevertheless, there is still a lack of consistent results regarding common steroid predictors of PCOS. Therefore, a liquid chromatography tandem mass spectrometry (HPLC-QqQ/MS) method was developed and validated to determine the concentrations of four classic androgens: androstenedione (An-dione), testosterone (T), 5α-dihydrotestosterone (DHT) and androsterone (An) in urine samples obtained from women with PCOS and healthy controls. The limits of detection were between 0.04 and 0.09 ng/mL, while the limits of quantification ranged from 0.1 to 0.3 ng/mL respectively. As a pre-treatment procedure prior to analysis, hydrolysis using β-glucuronidase and thin film solid-phase microextraction (TF-SPME) was applied. The methodology was employed to perform targeted metabolomics of urinary steroids in women with PCOS and healthy controls. All measured androgens: An-dione (p < 0.0001), T (p = 0.0001), DHT (p < 0.0001) and An (p = 0.0002) showed significantly higher concentrations in the urine of women with PCOS. The largest difference in the mean concentration was found for DHT, which was 2.8 times higher in the PCOS group (13.9 ± 14.1 ng/mg creatinine) in comparison to healthy controls (4.9 ± 3.4 ng/mg creatinine). The results of receiver operating characteristic curve indicated that determination of the panel of three urinary androgens: T+DHT+An-dione with, under the study assumptions, was the best predictor of PCOS diagnosis (AUC of ROC curve = 0.91 (95 % CI: 0.8212-0.9905). The application of an LC-MS/MS-based analysis, together with highly sensitive extraction techniques like TF-SPME, is a suitable approach to perform fast assays and obtain reliable results - crucial in the search for valuable and significant steroids predictors of PCOS.

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.

Molecular and Functional Characterization of Human Sex-Determining Region on the Y Chromosome Variants Using Protamine 1 Promoter

The male sex-determining gene, sex-determining region on the Y chromosome (SRY), is expressed in adult testicular germ cells; however, its role in regulating spermatogenesis remains unclear. The role of SRY in the postmeiotic gene expression was investigated by determining the effect of SRY on the promoter of the haploid-specific Protamine 1 (PRM1) gene, which harbors five distinct SRY-binding motifs. In a luciferase reporter assay system, SRY upregulates PRM1 promoter activity in vitro in a dose-dependent manner. Through a gel-shift assay involving a 31-bp DNA fragment encompassing the SRY element within the PRM1 promoter, the third SRY-binding site on the sense strand (-373/-367) was identified as crucial for PRM1 promoter activation. This assay was extended to analyze 9 SRY variants found in the testicular DNA of 44 azoospermia patients. The findings suggest that SRY regulates PRM1 promoter activity by directly binding to its specific motif within the PRM1 promoter.

An extra-genital cell population contributes to urethra closure during mouse penis development

Hypospadias, or incomplete closure of the urethra along the penis, is the second most common birth defect in the United States. We discovered a population of extra-genital mesenchymal cells that are essential for proper penile urethra closure in mouse embryos. This extra-genital population first appeared in the mesenchyme posterior to the hindlimb of the fetus after the onset of penis formation. These extra-genital cells, which transiently express a lineage marker Nr5a1, migrated centrally and colonized the penis bilateral to the urethra epithelium. Removal of the Nr5a1+ extra-genital cells, using a cell-type specific ablation model, resulted in severe hypospadias. The absence of extra-genital cells had the most significant impacts on another mesenchymal cells, the peri-urethra that were immediately adjacent to the Nr5a1+ extra-genital cells. Single cell mRNA sequencing revealed that the extra-genital cells extensively interact with the peri-urethra, particularly through Neuregulin 1, an epidermal Growth Factor (EGF) ligand. Disruption of Neuregulin 1 signaling in the ex-vivo slice culture system led to failure of urethra closure, recapitulating the phenotypes of extra-genital cell ablation. These results demonstrate that the Nr5a1+ extra-genital mesenchymal cells from outside of the fetal penis are indispensable for urethra closure through their interaction with the peri-urethra mesenchymal cells. This discovery provides a new entry point to understand the biology of penis formation and potential causes of hypospadias in humans.

Influence of cholesterol on kinetic parameters for human aromatase (P450 19A1) in phospholipid nanodiscs

Cholesterol, a significant constituent of the endoplasmic reticulum membrane, exerts a substantial effect on the membrane's biophysical and mechanical properties. Cholesterol, however, is often neglected in model systems used to study membrane-bound proteins. For example, the influence of cholesterol on the enzymatic functions of type 2 cytochromes P450, which require a phospholipid bilayer and the redox partner P450-oxidoreductase (POR) for activity, are rarely investigated. Human aromatase (P450 19A1) catalyzes three sequential oxygenations of 19‑carbon steroids to estrogens and is widely expressed across various tissues, which are characterized by varying cholesterol compositions. Our study examined the impact of cholesterol on the functionality of the P450 19A1 complex with POR. Nanodiscs containing P450 19A1 with 20% cholesterol/80% phospholipid had similar rates and affinity of androstenedione binding as phospholipid-only P450 19A1 nanodiscs, and rates of product formation were indistinguishable among these conditions. In contrast, the rate of the first electron transfer from POR to P450 19A1 was 3-fold faster in cholesterol-containing nanodiscs than in phospholipid-only nanodiscs. These results suggest that cholesterol influences some aspects of POR interaction with P450 19A1 and might serve as an additional regulatory mechanism in this catalytic system.

Differences of Sex Development: Current Issues and Controversies

Differences of sex development (DSD) encompass a broad range of conditions in which the development of chromosomal, gonadal, or anatomic sex is not typically male or female. Terms used to describe DSD are controversial, and continuously evolving. An individualized, multidisciplinary approach is key to both the diagnosis and management of DSD. Recent advances in DSD care include expanded genetic testing options, a more nuanced approach to gonadal management, and an emphasis on shared decision-making, particularly related to external genital surgical procedures. The timing of DSD surgery is currently being questioned and debated in both medical and advocacy/activism spheres.

Monorchidism in a Phenotypic Mare With a 64,XY, SRY-Positive Karyotype

Disorders of sexual development (DSD) are associated with atypical chromosomal, gonadal, or phenotypic sex. It is likely that the number of cases of DSD are underestimated in the equine population. Monorchidism in the horse is very rare. This case report describes the clinical assessment of a phenotypic mare with stallion-like behavior which led to the diagnosis of a DSD. A 4-year-old Quarter Horse mare presented in good body condition, with normal external genitalia for a mare, and normal mammary glands with two bilaterally symmetric teats. No uterus, cervix, or gonads were detected on transrectal palpation. Transrectal ultrasonography revealed a single gonad in the right dorsal abdomen with the morphologic appearance of a testicle. Presurgical hormonal evaluation revealed elevated serum testosterone and anti-Müllerian hormone (AMH) concentrations. The right gonad was successfully removed via standing exploratory laparoscopy and submitted for histopathology. No gonad was identified on the left side during laparoscopy. Histopathologic examination confirmed that the excised gonad was a testicle. Cytogenetic and molecular analysis revealed a 64,XY, SRY-positive chromosomal constitution. Hormonal evaluation 5 weeks after surgery revealed low serum testosterone and AMH levels. A diagnosis of monorchidism was based on ultrasound examination, laparoscopic exploration of the abdomen, removal of a single gonad, and a subsequent decrease in serum testosterone and AMH concentrations to basal levels. In summary, a combination of clinical signs, endocrine evaluation, chromosomal and molecular analysis, and histopathology can be used in the diagnosis of DSD conditions.

Androgen signalling in the ovaries and endometrium

Currently, our understanding of hormonal regulation within the female reproductive system is largely based on our knowledge of estrogen and progesterone signalling. However, while the important functions of androgens in male physiology are well known, it is also recognized that androgens play critical roles in the female reproductive system. Further, androgen signalling is altered in a variety of gynaecological conditions, including endometriosis and polycystic ovary syndrome, indicative of regulatory roles in endometrial and ovarian function. Co-regulatory mechanisms exist between different androgens, estrogens, and progesterone, resulting in a complex network of steroid hormone interactions. Evidence from animal knockout studies, in vitro experiments, and human data indicate that androgen receptor expression is cell-specific and menstrual cycle stage-dependent, with important regulatory roles in the menstrual cycle, endometrial biology, and follicular development in the ovaries. This review will discuss the expression and co-regulatory interactions of androgen receptors, highlighting the complexity of the androgen signalling pathway in the endometrium and ovaries, and the synthesis of androgens from additional alternative pathways previously disregarded as male-specific. Moreover, it will illustrate the challenges faced when studying androgens in female biology, and the need for a more in-depth, integrative view of androgen metabolism and signalling in the female reproductive system.

Effects of Pregnanolone Glutamate and Its Metabolites on GABAA and NMDA Receptors and Zebrafish Behavior

Multiple molecular targets have been identified to mediate membrane-delimited and nongenomic effects of natural and synthetic steroids, but the influence of steroid metabolism on neuroactive steroid signaling is not well understood. To begin to address this question, we set out to identify major metabolites of a neuroprotective synthetic steroid 20-oxo-5β-pregnan-3α-yl l-glutamyl 1-ester (pregnanolone glutamate, PAG) and characterize their effects on GABAA and NMDA receptors (GABARs, NMDARs) and their influence on zebrafish behavior. Gas chromatography-mass spectrometry was used to assess concentrations of PAG and its metabolites in the hippocampal tissue of juvenile rats following intraperitoneal PAG injection. PAG is metabolized in the peripheral organs and nervous tissue to 20-oxo-17α-hydroxy-5β-pregnan-3α-yl l-glutamyl 1-ester (17-hydroxypregnanolone glutamate, 17-OH-PAG), 3α-hydroxy-5β-pregnan-20-one (pregnanolone, PA), and 3α,17α-dihydroxy-5β-pregnan-20-one (17-hydroxypregnanolone, 17-OH-PA). Patch-clamp electrophysiology experiments in cultured hippocampal neurons demonstrate that PA and 17-OH-PA are potent positive modulators of GABARs, while PAG and 17-OH-PA have a moderate inhibitory effect at NMDARs. PAG, 17-OH-PA, and PA diminished the locomotor activity of zebrafish larvae in a dose-dependent manner. Our results show that PAG and its metabolites are potent modulators of neurotransmitter receptors with behavioral consequences and indicate that neurosteroid-based ligands may have therapeutic potential.

Non-steroidal CYP17A1 Inhibitors: Discovery and Assessment

CYP17A1 is an enzyme that plays a major role in steroidogenesis and is critically involved in the biosynthesis of steroid hormones. Therefore, it remains an attractive target in several serious hormone-dependent cancer diseases, such as prostate cancer and breast cancer. The medicinal chemistry community has been committed to the discovery and development of CYP17A1 inhibitors for many years, particularly for the treatment of castration-resistant prostate cancer. The current Perspective reflects upon the discovery and evaluation of non-steroidal CYP17A1 inhibitors from a medicinal chemistry angle. Emphasis is placed on the structural aspects of the target, key learnings from the presented chemotypes, and design guidelines for future inhibitors.

Exploring the human chorionic gonadotropin induced steroid secretion profile of mouse Leydig tumor cell line 1 by a 20 steroid LC-MS/MS panel

The canonical androgen synthesis in Leydig cells involves Δ5 and Δ4 steroids. Besides, the backdoor pathway, eompassing 5α and 5α,3α steroids, is gaining interest in fetal and adult pathophysiology. Moreover, the role of androgen epimers and progesterone metabolites is still unknown. We developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring 20 steroids and used it to investigate the steroid secretion induced by human chorionic gonadotropin (hCG) in the mouse Leydig tumor cell line 1 (mLTC1). Steroids were extracted from 500 µL supernatants from unstimulated or 100 pM hCG-exposed mLTC1 cells, separated on a Luna C8 100 × 3 mm, 3 µm column, with 100 µM NH4F and methanol as mobile phases, and analyzed by positive electrospray ionization and multiple reaction monitoring. Sensitivity ranged within 0.012-38.0 nmol/L. Intra-assay and inter-assay imprecision were < 9.1% and 10.0%, respectively. Trueness, recovery and matrix factor were within 93.4-122.0, 55.6-104.1 and 76.4-106.3%, respectively. Levels of 16OH-progesterone, 11-deoxycortisol, androstenedione, 11-deoxycorticosterone, testosterone, 17OH-progesterone, androstenedione, epitestosterone, dihydrotestosterone, progesterone, androsterone and 17OH-allopregnanolone were effectively measured. Traces of 17OH-dihydroprogesterone, androstanediol and dihydroprogesterone were found, whereas androstenediol, 17OH-pregnenolone, dehydroepiandrosterone, pregnenolone and allopregnanolone showed no peak. hCG induced an increase of 80.2-102.5 folds in 16OH-progesterone, androstenedione and testosterone, 16.6 in dihydrotestosterone, 12.2-27.5 in epitestosterone, progesterone and metabolites, 8.1 in 17OH-allopregnanolone and ≤ 3.3 in 5α and 5α,3α steroids. In conclusion, our LC-MS/MS method allows exploring the Leydig steroidogenesis flow according to multiple pathways. Beside the expected stimulation of the canonical pathway, hCG increased progesterone metabolism and, to a low extent, the backdoor route.

Genetic control of typical and atypical sex development

Sex development relies on the sex-specific action of gene networks to differentiate the bipotential gonads of the growing fetus into testis or ovaries, followed by the differentiation of internal and external genitalia depending on the presence or absence of hormones. Differences in sex development (DSD) arise from congenital alterations during any of these processes, and are classified depending on sex chromosomal constitution as sex chromosome DSD, 46,XY DSD or 46,XX DSD. Understanding the genetics and embryology of typical and atypical sex development is essential for diagnosing, treating and managing DSD. Advances have been made in understanding the genetic causes of DSD over the past 10 years, especially for 46,XY DSD. Additional information is required to better understand ovarian and female development and to identify further genetic causes of 46,XX DSD, besides congenital adrenal hyperplasia. Ongoing research is focused on the discovery of further genes related to typical and atypical sex development and, therefore, on improving diagnosis of DSD.

Pregnancy and Prenatal Management of Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive diseases that may cause cortisol insufficiency together with other hormonal alterations. The most common form is 21-hydroxylase deficiency, in which the lack of pituitary negative feedback causes an increase in ACTH and adrenal androgens. Classical forms of CAHs can lead to severe adrenal failure and female virilization. To date, the appropriate management of pregnant CAH patients is still debated regarding appropriate maternal therapy modifications during pregnancy and the risks and benefits of prenatal treatment of the fetus. We conducted a literature search of relevant papers to collect current evidence and experiences on the topic. The most recent and significant articles were selected, and current international guidelines were consulted to update current recommendations and guide clinical practice. Given the lack of randomized clinical trials and other high-quality scientific evidence, the issue is still debated, and great heterogeneity exists in current practice in terms of risk/benefit evaluation and pharmacological choices for pregnancy and prenatal treatment. Glucocorticoid therapy is advised not only in classical CAH patients but also in non-classical, milder forms. The choice of which glucocorticoid to use, and the safety and benefits of dexamethasone therapy aimed at preventing genital virilization are still debated issues. Several advances, however, have been made, especially in terms of fertility and reproduction. This review aims to present the most recent scientific and real-world updates on pregnancy and prenatal management of CAH, with the presentation of various clinical scenarios and specific case-by-case recommendations.

Cohort profile: pathways to care among people with disorders of sex development (DSD)

PURPOSE

The 'DSD Pathways' study was initiated to assess health status and patterns of care among people enrolled in large integrated healthcare systems and diagnosed with conditions comprising the broad category of disorders (differences) of sex development (DSD). The objectives of this communication are to describe methods of cohort ascertainment for two specific DSD conditions-classic congenital adrenal hyperplasia with 46,XX karyotype (46,XX CAH) and complete androgen insensitivity syndrome (CAIS).

PARTICIPANTS

Using electronic health records we developed an algorithm that combined diagnostic codes, clinical notes, laboratory data and pharmacy records to assign each cohort candidate a 'strength-of-evidence' score supporting the diagnosis of interest. A sample of cohort candidates underwent a review of the full medical record to determine the score cutoffs for final cohort validation.

FINDINGS TO DATE

Among 5404 classic 46,XX CAH cohort candidates the strength-of-evidence scores ranged between 0 and 10. Based on sample validation, the eligibility cut-off for full review was set at the strength-of-evidence score of ≥7 among children under the age of 8 years and ≥8 among older cohort candidates. The final validation of all cohort candidates who met the cut-off criteria identified 115 persons with classic 46,XX CAH. The strength-of-evidence scores among 648 CAIS cohort candidates ranged from 2 to 10. There were no confirmed CAIS cases among cohort candidates with scores <6. The in-depth medical record review for candidates with scores ≥6 identified 61 confirmed cases of CAIS.

FUTURE PLANS

As the first cohort of this type, the DSD Pathways study is well-positioned to fill existing knowledge gaps related to management and outcomes in this heterogeneous population. Analyses will examine diagnostic and referral patterns, adherence to care recommendations and physical and mental health morbidities examined through comparisons of DSD and reference populations and analyses of health status across DSD categories.

The consequence and mechanism of dietary flavonoids on androgen profiles and disorders amelioration

Androgen is a kind of steroid hormone that plays a vital role in reproductive system and homeostasis of the body. Disrupted androgen balance serves as the causal contributor to a series of physiological disorders and even diseases. Flavonoids, as an extremely frequent family of natural polyphenols, exist widely in plants and foods and have received great attention when considering their inevitable consumption and estrogen-like effects. Mounting evidence illustrates that flavonoids have a propensity to interfere with androgen synthesis and metabolism, and also have a designated improvement effect on androgen disorders. Therefore, flavonoids were divided into six subclasses based on the structural feature in this paper, and the literature about their effects on androgens published in the past ten years was summarized. It could be concluded that flavonoids have the potential to regulate androgen levels and biological effects, mainly by interfering with the hypothalamic-pituitary-gonadal axis, androgen synthesis and metabolism, androgen binding with its receptors and membrane receptors, and antioxidant effects. The faced challenges about androgen regulation by flavonoids masterly include target mechanism exploration, individual heterogeneity, food matrixes interaction, and lack of clinical study. This review also provides a scientific basis for nutritional intervention using flavonoids to improve androgen disorder symptoms.

Classic and backdoor pathways of androgen biosynthesis in human sexual development

Both genes and hormones regulate human sexual development. Although ovarian hormones are not essential for female external genitalia development, male sexual development requires the action of testicular testosterone and dihydrotestosterone (DHT). DHT is the most active endogenous androgen formed by the conversion of testosterone in genital skin. This synthesis route from cholesterol to DHT is called the conventional classic pathway. Recent investigations have reported an alternative ("backdoor") route for DHT formation that bypasses fetal testicular testosterone. This alternative route plays a crucial role in human hyperandrogenic disorders like congenital adrenal hyperplasia caused by P450c21 deficiency, polycystic ovary syndrome, and P450 oxidoreductase deficiency. In addition, mutations in AKR1C2 and AKR1C4, genes encoding 3α-reductases, have been implicated in disorders of sexual development, indicating that both the classic and backdoor routes are required for normal human male sexual development. More recently, androsterone was found to be the primary androgen of the human backdoor route. Androsterone and steroidal substrates specific to the backdoor route are predominantly found in the placenta, liver, and adrenal glands rather than in the testes. These findings are essential to understanding human sexual development.

Classic and current concepts in adrenal steroidogenesis: a reappraisal

Adrenal steroid biosynthesis and its related pathology are constant evolving disciplines. In this paper, we review classic and current concepts of adrenal steroidogenesis, plus control mechanisms of steroid pathways, distribution of unique enzymes and cofactors, and major steroid families. We highlight the presence of a "mineralocorticoid (MC) pathway of zona fasciculata (ZF)", where most circulating corticosterone and deoxycorticosterone (DOC) originate together with 18OHDOC, under ACTH control, a claim based on functional studies in normal subjects and in patients with 11β-, and 17α-hydroxylase deficiencies. We emphasize key differences between CYP11B1 (11β-hydroxylase) and CYP11B2 (aldosterone synthase) and the onset of a hybrid enzyme - CYP11B1/CYP11B2 -, responsible for aldosterone formation in ZF under ACTH control, in "type I familial hyperaldosteronism" (dexamethasone suppressible). In "apparent MC excess syndrome", peripheral conversion of cortisol to cortisone is impaired by lack of 11β-hydroxysteroid dehydrogenase type 2, permitting free cortisol access to MC receptors resulting in severe hypertension. We discuss two novel conditions involving the synthesis of adrenal androgens: the "backdoor pathway", through which dihydrotestosterone is formed directly from androsterone, being relevant for the fetoplacental setting and sexual differentiation of male fetuses, and the rediscovery of C19 11-oxygenated steroids (11-hydroxyandrostenedione and 11-ketotestosterone), active androgens and important markers of virilization in 21-hydroxylase deficiency and polycystic ovaries syndrome. Finally, we underline two enzyme cofactor deficiencies: cytochrome P450 oxidoreductase which partially affects 21- and 17α-hydroxylation, producing a combined clinical/hormonal picture and causing typical skeletal malformations (Antley-Bixler syndrome), and PAPSS2, coupled to SULT2A1, that promotes sulfation of DHEA to DHEAS, preventing active androgens to accumulate. Its deficiency results in reduced DHEAS and elevated DHEA and androgens with virilization. Future and necessary studies will shed light on remaining issues and questions on adrenal steroidogenesis.

A spatiotemporal steroidogenic regulatory network in human fetal adrenal glands and gonads

Human fetal adrenal glands produce substantial amounts of dehydroepiandrosterone (DHEA), which is one of the most important precursors of sex hormones. However, the underlying biological mechanism remains largely unknown. Herein, we sequenced human fetal adrenal glands and gonads from 7 to 14 gestational weeks (GW) via 10× Genomics single-cell transcriptome techniques, reconstructed their location information by spatial transcriptomics. Relative to gonads, adrenal glands begin to synthesize steroids early. The coordination among steroidogenic cells and multiple non-steroidogenic cells promotes adrenal cortex construction and steroid synthesis. Notably, during the window of sexual differentiation (8-12 GW), key enzyme gene expression shifts to accelerate DHEA synthesis in males and cortisol synthesis in females. Our research highlights the robustness of the action of fetal adrenal glands on gonads to modify the process of sexual differentiation.

Activin A and Sertoli Cells: Key to Fetal Testis Steroidogenesis

The long-standing knowledge that Sertoli cells determine fetal testosterone production levels is not widespread, despite being first reported over a decade ago in studies of mice. Hence any ongoing use of testosterone as a marker of Leydig cell function in fetal testes is inappropriate. By interrogating new scRNAseq data from human fetal testes, we demonstrate this situation is also likely to be true in humans. This has implications for understanding how disruptions to either or both Leydig and Sertoli cells during the in utero masculinization programming window may contribute to the increasing incidence of hypospadias, cryptorchidism, testicular germ cell tumours and adult infertility. We recently discovered that activin A levels directly govern androgen production in mouse Sertoli cells, because the enzymes that drive the conversion of the precursor androgen androstenedione to generate testosterone are produced exclusively in Sertoli cells in response to activin A. This minireview addresses the implications of this growing understanding of how in utero exposures affect fetal masculinization for future research on reproductive health, including during programming windows that may ultimately be relevant for organ development in males and females.

Role of sex steroids and prostaglandins during the luteal life cycle in domestic cats and lynxes

Although lynxes and domestic cats are both felids, their luteal life cycles differ. As in many species, corpora lutea (CLs) of domestic cats regress after pregnancy or pseudopregnancy. By contrast, CLs of lynxes do not functionally regress following the cycle of their formation. They stay physiologically active and persist for several years. To obtain an improved understanding of the life cycle of both species, we comparatively studied the CLs of these species in detail. In this review, we summarize the similarities and differences of their CLs regarding sex steroid and prostaglandin generation and receptors. The most evident differences were visible in the CLs of lynxes, which persist from previous cycles, compared with CLs of lynxes and domestic cats from the recent luteal cycle. We assume that these differences could indicate processes ensuring long-term luteal survival and functionality, for example, by high estrogen production/metabolism or by antioxidative effects.

The Neuroactive Steroid Pregnanolone Glutamate: Anticonvulsant Effect, Metabolites and Its Effect on Neurosteroid Levels in Developing Rat Brains

Pregnanolone glutamate (PA-G) is a neuroactive steroid that has been previously demonstrated to be a potent neuroprotective compound in several biological models in vivo. Our in vitro experiments identified PA-G as an inhibitor of N-methyl-D-aspartate receptors and a potentiator of γ-aminobutyric acid receptors (GABA_ARs). In this study, we addressed the hypothesis that combined GABA_AR potentiation and NMDAR antagonism could afford a potent anticonvulsant effect. Our results demonstrated the strong age-related anticonvulsive effect of PA-G in a model of pentylenetetrazol-induced seizures. PA-G significantly decreased seizure severity in 12-day-old animals, but only after the highest dose in 25-day-old animals. Interestingly, the anticonvulsant effect of PA-G differed both qualitatively and quantitatively from that of zuranolone, an investigational neurosteroid acting as a potent positive allosteric modulator of GABA_ARs. Next, we identified 17-hydroxy-pregnanolone (17-OH-PA) as a major metabolite of PA-G in 12-day-old animals. Finally, the administration of PA-G demonstrated direct modulation of unexpected neurosteroid levels, namely pregnenolone and dehydroepiandrosterone sulfate. These results suggest that compound PA-G might be a pro-drug of 17-OH-PA, a neurosteroid with a promising neuroprotective effect with an unknown mechanism of action that may represent an attractive target for studying perinatal neural diseases.

Disorders of Sex Development of Adrenal Origin

Disorders of Sex Development (DSD) are anomalies occurring in the process of fetal sexual differentiation that result in a discordance between the chromosomal sex and the sex of the gonads and/or the internal and/or external genitalia. Congenital disorders affecting adrenal function may be associated with DSD in both 46,XX and 46,XY individuals, but the pathogenic mechanisms differ. While in 46,XX cases, the adrenal steroidogenic disorder is responsible for the genital anomalies, in 46,XY patients DSD results from the associated testicular dysfunction. Primary adrenal insufficiency, characterized by a reduction in cortisol secretion and overproduction of ACTH, is the rule. In addition, patients may exhibit aldosterone deficiency leading to salt-wasting crises that may be life-threatening. The trophic effect of ACTH provokes congenital adrenal hyperplasia (CAH). Adrenal steroidogenic defects leading to 46,XX DSD are 21-hydroxylase deficiency, by far the most prevalent, and 11β-hydroxylase deficiency. Lipoid Congenital Adrenal Hyperplasia due to StAR defects, and cytochrome P450scc and P450c17 deficiencies cause DSD in 46,XY newborns. Mutations in SF1 may also result in combined adrenal and testicular failure leading to DSD in 46,XY individuals. Finally, impaired activities of 3βHSD2 or POR may lead to DSD in both 46,XX and 46,XY individuals. The pathophysiology, clinical presentation and management of the above-mentioned disorders are critically reviewed, with a special focus on the latest biomarkers and therapeutic development.

Uterine Involution of Mares Supplemented with Dietary Algae-Derived Omega-3 Fatty Acids During the Peripartum Period

Different approaches have been used to improve conception rates at foal heat. Omega-3 fatty acids family and derivatives have improved reproductive efficiency in ruminants, but literature lacks studies evaluating these components on equines. The objective of this study was to evaluate effects of mare dietary supplementation with microalgae rich in docosahexaenoic acid (DHA) during peripartum on follicular dynamics and uterine involution in early post-partum. Eighteen pregnant mares, no particular breed, 410 ± 39.5 kg body weight (BW), and 7.83 ± 2.01 yr old were used. Mares were randomly assigned to control (CONT) or supplementation with microalgae rich in DHA at 0.06 g/kg BW (ALG). Treatments were supplied from 90 d prior to expected foaling date until 7 d after first ovulation. Reproductive evaluations were performed during early post-partum until 7 d after first ovulation through rectal palpation and ultrasonography of the following parameters: uterine and endometrium diameters, intrauterine fluid (IUF), uterine echogenicity, uterus tone, and follicular dynamics. Endometrial cells samples were collected to assess mRNA expression of CRP, IL-1β and AKR1C4, using RT-qPCR. Data were analyzed by mixed procedure of SAS. ALG mares had smaller uterine horns diameters and greater uterine echogenicity during post-partum in comparison with CONT. No treatment effects were detected for other characteristics evaluated, but a day effect was observed for uterine and endometrium diameter, IUF, uterine echogenicity, and transcript abundance of endometrial AKR1C4. Supplementation with DHA during peripartum may benefit uterine involution process and odds of early conception, but more studies should be performed regarding fertility.

Dysregulated androgen synthesis and anti-androgen resistance in advanced prostate cancer

Current therapies for treating castration resistant prostate cancer (CRPC) include abiraterone and enzalutamide which function by inhibiting androgen signaling by targeting androgen synthesis and antagonizing the androgen receptor (AR) respectively. While these therapies are initially beneficial, resistance inevitably develops. A number of pathways have been identified to contribute to CRPC progression and drug resistance. Among these is aberrant androgen signaling perpetuated by increased expression and activity of androgenic enzymes. While abiraterone inhibits the androgenic enzyme, CYP17A1, androgen synthesis inhibition by abiraterone is incomplete and sustained androgenesis persists, in part due to increased levels of AKR1C3 and steroid sulfatase (STS). Expression of both of these enzymes is increased in CRPC and is associated with resistance to anti-androgens. A number of studies have identified methods for targeting these enzymes. Indomethacin, a non-steroidal anti-inflammatory drug commonly used to treat inflammatory arthritis has been well established as an inhibitor of AKR1C3. Treatment of CRPC cells with indomethacin reduces cell growth and improves the response to enzalutamide and abiraterone. Similarly, STS inhibitors have been shown to reduce intracrine androgens and also reduce CRPC growth and enhance anti-androgen treatment. In this review, we provide an overview of androgen synthesis in CRPC and strategies aimed at inhibiting intracrine androgens.

46,XX DSD: Developmental, Clinical and Genetic Aspects

Differences in sex development (DSD) in patients with 46,XX karyotype occur by foetal or postnatal exposure to an increased amount of androgens. These disorders are usually diagnosed at birth, in newborns with abnormal genitalia, or later, due to postnatal virilization, usually at puberty. Proper diagnosis and therapy are mostly based on the knowledge of normal development and molecular etiopathogenesis of the gonadal and adrenal structures. This review aims to describe the most relevant data that are correlated with the normal and abnormal development of adrenal and gonadal structures in direct correlation with their utility in clinical practice, mainly in patients with 46,XX karyotype. We described the prenatal development of structures together with the main molecules and pathways that are involved in sex development. The second part of the review described the physical, imaging, hormonal and genetic evaluation in a patient with a disorder of sex development, insisting more on patients with 46,XX karyotype. Further, 95% of the etiology in 46,XX patients with disorders of sex development is due to congenital adrenal hyperplasia, by enzyme deficiencies that are involved in the hormonal synthesis pathway. The other cases are explained by genetic abnormalities that are involved in the development of the genital system. The phenotypic variability is very important in 46,XX disorders of sex development and the knowledge of each sign, even the most discreet, which could reveal such disorders, mainly in the neonatal period, could influence the evolution, prognosis and life quality long term.

Steroidogenic cytochrome P450 17A1 structure and function

Cytochrome P450 17A1 (CYP17A1) is a critical steroidogenic enzyme, essential for producing glucocorticoids and sex hormones. This review discusses the complex activity of CYP17A1, looking at its role in both the classical and backdoor steroidogenic pathways and the complex chemistry it carries out to perform both a hydroxylation reaction and a carbon-carbon cleavage, or lyase reaction. Functional and structural investigations have informed our knowledge of these two reactions. This review focuses on a few specific aspects of this discussion: the identities of reaction intermediates, the coordination of hydroxylation and lyase reactions, the effects of cytochrome b5, and conformational selection. These discussions improve understanding of CYP17A1 in a physiological setting, where CYP17A1 is implicated in a variety of steroidogenic diseases. This information can be used to improve ways in which CYP17A1 can be effectively modulated to treat diseases such as prostate and breast cancer, Cushing's syndrome, and glioblastoma.

The Role of Androgen Signaling in Male Sexual Development at Puberty

Puberty is characterized by major changes in the anatomy and function of reproductive organs. Androgen activity is low before puberty, but during pubertal development, the testes resume the production of androgens. Major physiological changes occur in the testicular cell compartments in response to the increase in intratesticular testosterone concentrations and androgen receptor expression. Androgen activity also impacts on the internal and external genitalia. In target cells, androgens signal through a classical and a nonclassical pathway. This review addresses the most recent advances in the knowledge of the role of androgen signaling in postnatal male sexual development, with a special emphasis on human puberty.

Expression of Mafb is down-regulated in the foreskin of children with hypospadias

BACKGROUND

Hypospadias is the second most common congenital malformation in males. Although the aetiology of hypospadias is not clear, it is generally thought to be affected by both genetic and environmental endocrine-disrupting factors that affect the development of the urethra, leading to deformity.

OBJECTIVE

To investigate the difference in expression of the transcription factor Mafb in hypospadias and normal penile tissues and to assess whether it is related to the occurrence of hypospadias.

STUDY DESIGN

Penile tissue was obtained from children with hypospadias who underwent surgical repair at the Children's Hospital of Chongqing Medical University. Patients diagnosed with undescended testicles, intersex status or endocrine abnormalities were excluded from the study. Twenty-five cases with hypospadias (average 3.5 years old) and 15 cases with circumcisions (as control) (average 5 years old) were included in this study. Real-time quantitative polymerase chain reaction, Immunochemistry and Western blot were used to detect the expression of Mafb.

RESULTS

Mafb mRNA expressions in the prepuce of cases with hypospadias was significantly reduced compared with that in the controls [(1.179 ± 0.1275), (0.6652 ± 0.07506), p < 0.05)]. Hypospadias cases also showed decreased Mafb protein expression in the preputial subcutaneous mesenchymal cell layer. Mafb protein levels were significantly decreased in those with hypospadias compared with controls [(1.932 ± 0.1139), (1.006 ± 0.03312), p < 0.05]. However, no such differences were found in Mafb expression between subjects with mild and severe hypospadias.

DISCUSSION

Compared to the normal foreskin, expression of the Mafb gene was down-regulated at both mRNA and protein levels, which was consistent with our RNA-seq sequencing results in Diethylhexyl phthalate (DEHP)-induced hypospadias rats. This study is the first to report abnormal expression of Mafb in the preputial tissue of hypospadias cases. An in-depth study of the relationship between Mafb and cell proliferation, apoptosis, and urethra development may reveal the pathogenesis of hypospadias.

CONCLUSION

Expression of the Mafb gene and protein in the foreskin of children with hypospadias is lower than that in normal foreskin. We postulate that such abnormal expression of the Mafb gene may be related to the occurrence of hypospadias and that this abnormal expression may affect the development of the urethra during the embryonic period.

The role of gonadotropins in testicular and adrenal androgen biosynthesis pathways-Insights from males with congenital hypogonadotropic hypogonadism on hCG/rFSH and on testosterone replacement

OBJECTIVE

To delineate the role of gonadotropins in male androgen biosynthesis pathways.

DESIGN

Case-control study.

PATIENTS AND MEASUREMENTS

Twenty five males with congenital hypogonadotropic hypogonadism (CHH) underwent hCG/rFSH and testosterone treatment sequentially. Serum steroid hormone profiles (testosterone precursors and metabolites) on both replacement regimens were analysed, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and compared to those of healthy controls, matched by age, BMI and serum testosterone.

RESULTS

On testosterone replacement, serum concentrations of the classic Δ4 pathway hormones progesterone and 17-hydroxy-progesterone (17-OHP), and the marker steroid of an alternative pathway of testosterone synthesis (androstenediol) were decreased, compared to controls. Androstanediol, a marker of the backdoor pathway of dihydrotestosterone (DHT) synthesis, was increased. 17-OH-pregnenolone, androstenedione and DHEAS (Δ5 pathway), three 11-oxygenated C19 androgens (11-keto-A4, 11-keto-T and 11-keto-DHT) and the testosterone (T) metabolites DHT and 17ß-oestradiol (E2) were similar to controls. On gonadotropin replacement, 17-OHP, 17-OH-pregnenolone, DHEAS and androstenedione, as well as DHT, androstenediol, and all 11-oxygenated C19 androgens were normal. Progesterone (Δ4 pathway) was slightly decreased, and androstanediol (backdoor DHT pathway) and E2 (T metabolite) were increased.

CONCLUSIONS

In males with CHH, serum steroid hormone profiles resemble those of healthy men, if hCG/rFSH is used for substitution. Gonadotropins contribute to steroid hormone production along the classic Δ4 pathway and co-activate an alternative pathway of testosterone biosynthesis via androstenediol. Backdoor DHT biosynthesis, Δ5 17-OH-pregnenolone, DHEA(S) and androstenedione synthesis and 11-oxygenated C19 androgen production are activated independently of gonadotropins. The androgen replacement modality used for treatment of hypogonadal males with absent or reduced endogenous LH/FSH secretion may impact on long-term health and quality of life.

Exome sequencing identified compound heterozygous mutations in the SRD5A2 gene in a case of 46,XY ambiguous genitalia

The disorders of sexual development (DSD) represent an array of phenotypes with ambiguous genitalia. The present case had microphallus with fused and bifid scrotum and was initially assigned androgen insensitivity syndrome; however, sequencing of the complete coding region of the androgen receptor gene failed to identify a causative mutation. We undertook whole exome sequencing for identification of the pathogenic mutation. The most promising pathogenic variants were genotyped using Sanger sequencing to confirm the genotypes. We found compound heterozygous mutations, c.169G>T and c.586G>A in the SRD5A2 gene in this case, resulting in a nonsense (p.Glu57Ter) and a nonsynonymous substitution (p.Gly196Ser), respectively. While the nonsense mutation would result in a truncated protein, p.Gly196Ser substitution has been previously reported to be pathogenic. The mutations were confirmed by Sanger sequencing. Sequencing of 96 normal male individuals did not show the above mutations, suggesting their pathogenic nature. In conclusion, we identified compound heterozygous pathogenic mutations, c.169G>T (p.Glu57Ter) and c.586G>A (p.Gly196Ser), in the SRD5A2 gene in a case of ambiguous genitalia. p.Glu57Ter is a novel mutation, which in compound heterozygote combination with Gly196Ser causes 5a reductase deficiency.

Alteration of the steroidogenesis in boys with autism spectrum disorders

The etiology of autism spectrum disorders (ASD) remains unknown, but associations between prenatal hormonal changes and ASD risk were found. The consequences of these changes on the steroidogenesis during a postnatal development are not yet well known. The aim of this study was to analyze the steroid metabolic pathway in prepubertal ASD and neurotypical boys. Plasma samples were collected from 62 prepubertal ASD boys and 24 age and sex-matched controls (CTRL). Eighty-two biomarkers of steroidogenesis were detected using gas-chromatography tandem-mass spectrometry. We observed changes across the whole alternative backdoor pathway of androgens synthesis toward lower level in ASD group. Our data indicate suppressed production of pregnenolone sulfate at augmented activities of CYP17A1 and SULT2A1 and reduced HSD3B2 activity in ASD group which is partly consistent with the results reported in older children, in whom the adrenal zona reticularis significantly influences the steroid levels. Furthermore, we detected the suppressed activity of CYP7B1 enzyme readily metabolizing the precursors of sex hormones on one hand but increased anti-glucocorticoid effect of 7α-hydroxy-DHEA via competition with cortisone for HSD11B1 on the other. The multivariate model found significant correlations between behavioral indices and circulating steroids. From dependent variables, the best correlation was found for the social interaction (28.5%). Observed changes give a space for their utilization as biomarkers while reveal the etiopathogenesis of ASD. The aforementioned data indicate a direction of the future research with a focus on the expression and functioning of genes associated with important steroidogenic enzymes in ASD patients from early childhood to adrenarche.

Molecular Basis of CYP19A1 Deficiency in a 46,XX Patient With R550W Mutation in POR: Expanding the PORD Phenotype

CONTEXT

Mutations in cytochrome P450 oxidoreductase (POR) cause a form of congenital adrenal hyperplasia (CAH). We report a novel R550W mutation in POR identified in a 46,XX patient with signs of aromatase deficiency.

OBJECTIVE

Analysis of aromatase deficiency from the R550W mutation in POR.

DESIGN, SETTING, AND PATIENT

Both the child and the mother had signs of virilization. Ultrasound revealed the presence of uterus and ovaries. No defects in CYP19A1 were found, but further analysis with a targeted Disorders of Sexual Development NGS panel (DSDSeq.V1, 111 genes) on a NextSeq (Illumina) platform in Madrid and Barcelona, Spain, revealed compound heterozygous mutations c.73_74delCT/p.L25FfsTer93 and c.1648C > T/p.R550W in POR. Wild-type and R550W POR were produced as recombinant proteins and tested with multiple cytochrome P450 enzymes at University Children's Hospital, Bern, Switzerland.

MAIN OUTCOME MEASURE AND RESULTS

POR-R550W showed 41% of the WT activity in cytochrome c and 7.7% activity for reduction of MTT. Assays of CYP19A1 showed a severe loss of activity, and CYP17A1 as well as CYP21A2 activities were also lost by more than 95%. Loss of CYP2C9, CYP2C19, and CYP3A4 activities was observed for the R550W-POR. Predicted adverse effect on aromatase activity as well as a reduction in binding of NADPH was confirmed.

CONCLUSIONS

Pathological effects due to POR-R550W were identified, expanding the knowledge of molecular pathways associated with aromatase deficiency. Screening of the POR gene may provide a diagnosis in CAH without defects in genes for steroid metabolizing enzymes.

The role of miRNAs in regulating adrenal and gonadal steroidogenesis

miRNAs are endogenous noncoding single-stranded small RNAs of ~22 nucleotides in length that post-transcriptionally repress the expression of their various target genes. They contribute to the regulation of a variety of physiologic processes including embryonic development, differentiation and proliferation, apoptosis, metabolism, hemostasis and inflammation. In addition, aberrant miRNA expression is implicated in the pathogenesis of numerous diseases including cancer, hepatitis, cardiovascular diseases and metabolic diseases. Steroid hormones regulate virtually every aspect of metabolism, and acute and chronic steroid hormone biosynthesis is primarily regulated by tissue-specific trophic hormones involving transcriptional and translational events. In addition, it is becoming increasingly clear that steroidogenic pathways are also subject to post-transcriptional and post-translational regulations including processes such as phosphorylation/dephosphorylation, protein‒protein interactions and regulation by specific miRNAs, although the latter is in its infancy state. Here, we summarize the recent advances in miRNA-mediated regulation of steroidogenesis with emphasis on adrenal and gonadal steroidogenesis.

Polycystic Ovary Syndrome: Pathophysiology, Presentation, and Treatment With Emphasis on Adolescent Girls

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by hyperandrogenism and chronic anovulation. Depending on diagnostic criteria, 6% to 20% of reproductive aged women are affected. Symptoms of PCOS arise during the early pubertal years. Both normal female pubertal development and PCOS are characterized by irregular menstrual cycles, anovulation, and acne. Owing to the complicated interwoven pathophysiology, discerning the inciting causes is challenging. Most available clinical data communicate findings and outcomes in adult women. Whereas the Rotterdam criteria are accepted for adult women, different diagnostic criteria for PCOS in adolescent girls have been delineated. Diagnostic features for adolescent girls are menstrual irregularity, clinical hyperandrogenism, and/or hyperandrogenemia. Pelvic ultrasound findings are not needed for the diagnosis of PCOS in adolescent girls. Even before definitive diagnosis of PCOS, adolescents with clinical signs of androgen excess and oligomenorrhea/amenorrhea, features of PCOS, can be regarded as being “at risk for PCOS.” Management of both those at risk for PCOS and those with a confirmed PCOS diagnosis includes education, healthy lifestyle interventions, and therapeutic interventions targeting their symptoms. Interventions can include metformin, combined oral contraceptive pills, spironolactone, and local treatments for hirsutism and acne. In addition to ascertaining for associated comorbidities, management should also include regular follow-up visits and planned transition to adult care providers. Comprehensive knowledge regarding the pathogenesis of PCOS will enable earlier identification of girls with high propensity to develop PCOS. Timely implementation of individualized therapeutic interventions will improve overall management of PCOS during adolescence, prevent associated comorbidities, and improve quality of life.