Molecular biology of the 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase gene family

Steroid metabolism and hormonal dynamics in normal and malignant ovaries

The ovaries are key steroid hormone production sites in post-pubertal females. However, current research on steroidogenic enzymes, endogenous hormone concentrations and their effects on healthy ovarian function and malignant development is limited. Here, we discuss the importance of steroid enzymes in normal and malignant ovaries, alongside hormone concentrations, receptor expression and action. Key enzymes include STS, 3β-HSD2, HSD17B1, ARK1C3, and aromatase, which influence ovarian steroidal action. Both androgen and oestrogen action, via their facilitating enzyme, drives ovarian follicle activation, development and maturation in healthy ovarian tissue. In ovarian cancer, some data suggest STS and oestrogen receptor α may be linked to aggressive forms, while various oestrogen-responsive factors may be involved in ovarian cancer metastasis. In contrast, androgen receptor expression and action vary across ovarian cancer subtypes. For future studies investigating steroidogenesis and steroidal activity in ovarian cancer, it is necessary to differentiate between disease subtypes for a comprehensive understanding.

Identification and function analysis of steroid hormone synthesis pathway-related gene-Hsd3b in Scylla paramamosain

Mud crab (Scylla paramamosain) has become an important mariculture crab along the southeast coast of China due to its strong adaptability, delicious taste, and rich nutrition. Several vertebrate steroid hormones and their synthesis-related genes and receptors have been found in crustaceans, but there are few reports on their synthesis process and mechanism. 3-beta-hydroxysteroid dehydrogenase (HSD3B) is a member of the Short-chain Dehydrogenase/Reductase (SDR) family, and an indispensable protein in vertebrates' steroid hormone synthesis pathway. In this study, the SpHsd3b gene sequence was obtained from the transcriptome data of S. paramamosain, and its full-length open reading frame (ORF) was cloned. The spatial and temporal expression pattern of SpHsd3b was performed by quantitative real-time PCR (qRT-PCR). SpHsd3b dsRNA interference (RNAi) and HSD3B inhibitor (trilostane) were used to analyze the function of SpHSD3B. The results showed that the SpHsd3b gene has an 1113 bp ORF encoding 370 amino acids with a 3β-HSD domain. SpHSD3B has lower homology with HSD3B of vertebrates and higher homology with HSD3B of crustaceans. SpHsd3b was expressed in all examined tissues in mature crabs, and its expression was significantly higher in the testes than in the ovaries. SpHsd3b expression level was highest in the middle stage of testicular development, while its expression was higher in the early and middle stages of ovarian development. RNAi experiment and trilostane injection results showed that SpHSD3B had regulatory effects on several genes related to gonadal development and steroid hormone synthesis. 15-day trilostane suppression could also inhibit ovarian development and progesterone level of hemolymph. According to the above results, crustaceans may have steroid hormone synthesis pathways like vertebrates, and the Hsd3b gene may be involved in the gonadal development of crabs. This study provides further insight into the function of genes involved in steroid hormone synthesis in crustaceans.

Effects of organochlorine pesticides on human and rat 17β-hydroxysteroid dehydrogenase 1 activity: Structure-activity relationship and in silico docking analysis

The objective of this study was to examine the effect of 11 organochlorine pesticides on human and rat 17β-Hydroxysteroid dehydrogenase 1 (17β-HSD1) in human placental and rat ovarian microsome and on estradiol production in BeWo cells. The results showed that the IC50 values for endosulfan, fenhexamid, chlordecone, and rhothane on human 17β-HSD1 were 21.37, 73.25, 92.80, and 117.69 μM. Kinetic analysis revealed that endosulfan acts as a competitive inhibitor, fenhexamid as a mixed/competitive inhibitor, chlordecone and rhothane as a mixed/uncompetitive inhibitor. In BeWo cells, all insecticides except endosulfan significantly decreased estradiol production at 100 μM. For rats, the IC50 values for dimethomorph, fenhexamid, and chlordecone were 11.98, 36.92, and 109.14 μM. Dimethomorph acts as a mixed inhibitor, while fenhexamid acts as a mixed/competitive inhibitor. Docking analysis revealed that endosulfan and fenhexamid bind to the steroid-binding site of human 17β-HSD1. On the other hand, chlordecone and rhothane binds to a different site other than the steroid and NADPH-binding site. Dimethomorph binds to the steroid/NADPH binding site, and fenhexamid binds to the steroid binding site of rat 17β-HSD1. Bivariate correlation analysis showed a positive correlation between IC50 values and LogP for human 17β-HSD1, while a slight negative correlation was observed between IC50 values and the number of HBA. ADMET analysis provided insights into the toxicokinetics and toxicity of organochlorine pesticides. In conclusion, this study identified the inhibitory effects of 3-4 organochlorine pesticides and binding mechanisms on human and rat 17β-HSD1, as well as their impact on hormone production.

The metabolic activation of pentachlorophenol to chloranil as a potent inhibitor of human and rat placental 3β-hydroxysteroid dehydrogenases

Pentachlorophenol (PCP) is a widely used pesticide. However, whether PCP and its metabolite chloranil have endocrine-disrupting effects by inhibiting placental 3β-hydroxysteroid dehydrogenase 1 (3β-HSD1) remains unclear. The study used in vitro assays with human and rat placental microsomes to measure 3β-HSD activity as well as human JAr cells to evaluate progesterone production. The results showed that PCP exhibited moderate inhibition of human 3β-HSD1, with an IC50 value of 29.83 μM and displayed mixed inhibition in terms of mode of action. Conversely, chloranil proved to be a potent inhibitor, demonstrating an IC50 value of 147 nM, and displaying a mixed mode of action. PCP significantly decreased progesterone production by JAr cells at 50 μM, while chloranil markedly reduced progesterone production at ≥1 μM. Interestingly, PCP and chloranil moderately inhibited rat placental homolog 3β-HSD4, with IC50 values of 27.94 and 23.42 μM, respectively. Dithiothreitol (DTT) alone significantly increased human 3β-HSD1 activity. Chloranil not PCP mediated inhibition of human 3β-HSD1 activity was completely reversed by DTT and that of rat 3β-HSD4 was partially reversed by DTT. Docking analysis revealed that both PCP and chloranil can bind to the catalytic domain of 3β-HSDs. The difference in the amino acid residue Cys83 in human 3β-HSD1 may explain why chloranil is a potent inhibitor through its interaction with the cysteine residue of human 3β-HSD1. In conclusion, PCP is metabolically activated to chloranil as a potent inhibitor of human 3β-HSD1.

Structure-activity relationship and mechanistic study of organotins as inhibitors of human, pig, and rat gonadal 3β-hydroxysteroid dehydrogenases

Organotins have been widely used in various industrial applications. This study investigated the structure-activity relationship as inhibitors of human, pig, and rat gonadal 3β-hydroxysteroid dehydrogenases (3β-HSD). Human KGN cell, pig, and rat testis microsomes were utilized to assess the inhibitory effects of 18 organotins on the conversion of pregnenolone to progesterone. Among them, diphenyltin, triethyltin, and triphenyltin exhibited significant inhibitory activity against human 3β-HSD2 with IC50 values of 114.79, 106.98, and 5.40 μM, respectively. For pig 3β-HSD, dipropyltin, diphenyltin, triethyltin, tributyltin, and triphenyltin demonstrated inhibitory effects with IC50 values of 172.00, 100.19, 87.00, 5.75, and 1.65 μM, respectively. Similarly, for rat 3β-HSD1, dipropyltin, diphenyltin, triethyltin, tributyltin, and triphenyltin displayed inhibitory activity with IC50 values of 81.35, 43.56, 55.55, 4.09, and 0.035 μM, respectively. They were mixed inhibitors of pig and rat 3β-HSD, while triphenyltin was identified as a competitive inhibitor of human 3β-HSD2. The mechanism underlying the inhibition of organotins on 3β-HSD was explored, revealing that they may disrupt the enzyme activity by binding to cysteine residues in the catalytic sites. This proposition was supported by the observation that the addition of dithiothreitol reversed the inhibition caused by all organotins except for triethyltin, which was partially reversed. In conclusion, this study provides valuable insights into the structure-activity relationship of organotins as inhibitors of human, pig, and rat gonadal 3β-HSD. The mechanistic investigation suggests that these compounds likely exert their inhibitory effects through binding to cysteine residues in the catalytic sites.

Butorphanol inhibits androgen biosynthesis and metabolism in rat immature Leydig cells in vitro

Butorphanol is a synthetic opioid analgesic medication that is primarily used for the management of pain. Butorphanol may have an inhibitory effect on androgen biosynthesis and metabolism in rat immature Leydig cells. The objective of this study was to investigate the influence of butorphanol on androgen secretion by rat Leydig cells isolated from the 35-day-old male rats. Rat Leydig cells were cultured with 0.5-50 μM butorphanol for 3 h in vitro. Butorphanol at 5 and 50 μM significantly inhibited androgen secretion in immature Leydig cells. At 50 μM, butorphanol also blocked the effects of luteinizing hormone (LH) and 8bromo-cAMP-stimulated androgen secretion and 22R-hydroxycholesterol- and pregnenolone-mediated androgen production. Further analysis of the results showed that butorphanol downregulated the expression of genes involved in androgen production, including Lhcgr (LH receptor), Cyp11a1 (cholesterol side-chain cleavage enzyme), Srd5a1 (5α-reductase 1), and Akr1c14 (3α-hydroxysteroid dehydrogenase). Additionally, butorphanol directly inhibited HSD3B1 (3β-hydroxysteroid dehydrogenase 1) and SRD5A1 activity. In conclusion, butorphanol may have side effects of inhibiting androgen biosynthesis and metabolism in Leydig cells.

Structure-activity relationship and docking analysis of nature flavonoids as inhibitors of human and rat gonadal 3β-hydroxysteroid dehydrogenases for therapeutic purposes

The potential inhibitory effects of flavonoids on gonadal steroid biosynthesis have gained attention due to their widespread presence in natural plant sources. Specifically, our study focused on evaluating the inhibitory efficacy of these compounds on human 3β-hydroxysteroid dehydrogenase 2 (h3β-HSD2) and rat homolog r3β-HSD1, enzymes responsible for the conversion of pregnenolone to progesterone. Through our investigations, we observed that the potency of flavonoids was silymarin (IC50, 1.31 μM) > luteolin (4.63 μM) > tectorigenin > (5.86 μM), and rutin (44.12 μM) in inhibiting human KGN cell microsomal h3β-HSD2. Similarly, the potency of flavonoids was silymarin (9.50 μM) > luteolin (11.49 μM) > tectorigenin (14.06 μM), and rutin (145.71 μM) in inhibiting rat testicular r3β-HSD1. Silymarin, luteolin, and tectorigenin acted as mixed inhibitors of both human and rat 3β-HSDs. Luteolin and tectorigenin were able to penetrate human KGN cells to inhibit progesterone secretion. Furthermore, docking analysis and structure-activity relationship analysis highlighted the importance of hydrogen bond formation for the inhibitory efficacy of these compounds against h3β-HSD2 and r3β-HSD1. Overall, this study demonstrates that silymarin exhibits the most potent inhibition of human and rat gonadal 3β-HSDs, and significant SAR differences exist among the tested compounds.

In silico characterization of the novel SDR42E1 as a potential vitamin D modulator

The short-chain dehydrogenase/reductase (SDR) superfamily encompasses enzymes that play essential roles in the metabolism of steroid hormones and lipids. Despite an enigmatic function, recent genetic studies have linked the novel SDR 42 extended-1 (SDR42E1) gene to 25-hydroxyvitamin D levels. This study investigated the potential SDR42E1 functions and interactions with vitamin D using bioinformatics and molecular docking studies. Phylogenetic analysis unveiled that the nucleotide sequences of human SDR42E1 exhibit high evolutionary conservation across nematodes and fruit flies. Molecular docking analysis identified strong binding affinities between SDR42E1 and its orthologs with vitamin D3 and essential precursors, 8-dehydrocholesterol, followed by 7-dehydrocholesterol and 25-hydroxyvitamin D. The hydrophobic interactions observed between the protein residues and vitamin D compounds supported the predicted transmembrane localization of SDR42E1. Our investigation provides valuable insights into the potential role of SDR42E1 in skin vitamin D biosynthesis throughout species. This provides the foundation for future research and development of targeted therapies for vitamin D deficiency and related health conditions.

Redox Out of the Box: Catalytic Versatility Across NAD(P)H-Dependent Oxidoreductases

The asymmetric reduction of double bonds using NAD(P)H-dependent oxidoreductases has proven to be an efficient tool for the synthesis of important chiral molecules in research and on industrial scale. These enzymes are commercially available in screening kits for the reduction of C=O (ketones), C=C (activated alkenes), or C=N bonds (imines). Recent reports, however, indicate that the ability to accommodate multiple reductase activities on distinct C=X bonds occurs in different enzyme classes, either natively or after mutagenesis. This challenges the common perception of highly selective oxidoreductases for one type of electrophilic substrate. Consideration of this underexplored potential in enzyme screenings and protein engineering campaigns may contribute to the identification of complementary biocatalytic processes for the synthesis of chiral compounds. This review will contribute to a global understanding of the promiscuous behavior of NAD(P)H-dependent oxidoreductases on C=X bond reduction and inspire future discoveries with respect to unconventional biocatalytic routes in asymmetric synthesis.

Androgens at the skin surface regulate S. aureus pathogenesis through the activation of agr quorum sensing

Staphylococcus aureus, the most frequent cause of skin infections, is more common in men than women and selectively colonizes the skin during inflammation. Yet, the specific cues that drive infection in these settings remain unclear. Here we show that the host androgens testosterone and dihydrotestosterone promote S. aureus pathogenesis and skin infection. Without the secretion of these hormones, skin infection in vivo is limited. Testosterone activates S. aureus virulence in a concentration dependent manner through stimulation of the agr quorum sensing system, with the capacity to circumvent other inhibitory signals in the environment. Taken together, our work defines a previously uncharacterized inter-kingdom signal between the skin and the opportunistic pathogen S. aureus and identifies the mechanism of sex-dependent differences in S. aureus skin infection.

One-Sentence Summary

Testosterone promotes S. aureus pathogenesis through activation of the agr quorum sensing system.

Demethoxylation of curcumin enhances its inhibition on human and rat 17β-hydroxysteroid dehydrogenase 3: QSAR structure-activity relationship and in silico docking analysis

Curcuminoids have many pharmacological effects. They or their metabolites may have side effects by suppressing 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3). Herein, we investigated the inhibition of curcuminoids and their metabolites on human and rat 17β-HSD3 and analyzed their structure-activity relationship (SAR) and performed in silico docking. Curcuminoids and their metabolites ranked in terms of IC50 values against human 17β-HSD3 were bisdemethoxycurcumin (0.61 μM) > curcumin (8.63 μM) > demethoxycurcumin (9.59 μM) > tetrahydrocurcumin (22.04 μM) > cyclocurcumin (29.14 μM), and those against rat 17β-HSD3 were bisdemethoxycurcumin (3.94 μM) > demethoxycurcumin (4.98 μM) > curcumin (9.62 μM) > tetrahydrocurcumin (45.82 μM) > cyclocurcumin (143.5 μM). The aforementioned chemicals were mixed inhibitors for both enzymes. Molecular docking analysis revealed that they bind to the domain between the androstenedione and NADPH active sites of 17β-HSD3. Bivariate correlation analysis showed a positive correlation between LogP and pKa of curcumin derivatives with their IC50 values. Additionally, a 3D-QSAR analysis revealed that a pharmacophore model consisting of three hydrogen bond acceptor regions and one hydrogen bond donor region provided a better fit for bisdemethoxycurcumin compared to curcumin. In conclusion, curcuminoids and their metabolites possess the ability to inhibit androgen biosynthesis by directly targeting human and rat 17β-HSD3. The inhibitory strength of these compounds is influenced by their lipophilicity and ionization characteristics.

Comparison of structure-activity relationship for bisphenol analogs in the inhibition of gonadal 3β-hydroxysteroid dehydrogenases among human, rat, and mouse

Bisphenol A (BPA) is a widely used plastic material and its potential endocrine disrupting effect has restricted its use and increasing use of BPA alternatives has raised health concerns. However, the effect of bisphenol alternatives on steroidogenesis remains unclear. The objective of this study was to compare inhibitory potencies of 10 BPA alternatives in the inhibition of gonadal 3β-hydroxysteroid dehydrogenase (3β-HSD) in three species (human, rat and mouse). The inhibitory potency for human 3β-HSD2, rat 3β-HSD1, and mouse 3β-HSD6 ranged from bisphenol FL (IC50, 3.32 μM for human, 5.19 μM for rat, and 3.26 μM for mouse) to bisphenol E, F, and thiodiphenol (ineffective at 100 μM). Most BPA alternatives were mixed inhibitors of gonadal 3β-HSD and they dose-dependently inhibited progesterone formation in KGN cells. Molecular docking analysis showed that all BPA analogs bind to steroid and NAD+ active sites. Lipophilicity of BPA alternatives was inversely correlated with IC50 values. In conclusion, BPA alternatives mostly can inhibit gonadal 3β-HSDs and lipophilicity determines their inhibitory strength.

Chronic hypoxia stabilizes 3βHSD1 via autophagy suppression

Progression of prostate cancer depends on androgen receptor, which is usually activated by androgens. Therefore, a mainstay treatment is androgen deprivation therapy. Unfortunately, despite initial treatment response, resistance nearly always develops, and disease progresses to castration-resistant prostate cancer (CRPC), which remains driven by non-gonadal androgens synthesized in prostate cancer tissues. 3β-Hydroxysteroid dehydrogenase/Δ5-->4 isomerase 1 (3βHSD1) catalyzes the rate-limiting step in androgen synthesis. However, how 3βHSD1, especially the "adrenal-permissive" 3βHSD1(367T) that permits tumor synthesis of androgen from dehydroepiandrosterone (DHEA), is regulated at the protein level is not well understood. Here, we investigate how hypoxia regulates 3βHSD1(367T) protein levels. Our results show that, in vitro, hypoxia stabilizes 3βHSD1 protein by suppressing autophagy. Autophagy inhibition promotes 3βHSD1-dependent tumor progression. Hypoxia represses transcription of autophagy-related (ATG) genes by decreasing histone acetylation. Inhibiting deacetylase (HDAC) restores ATG gene transcription under hypoxia. Therefore, HDAC inhibition may be a therapeutic target for hypoxic tumor cells.

Developmental and adult stress: effects of steroids and neurosteroids

In humans, exposure to early life adversity has profound implications for susceptibility to developing neuropsychiatric disorders later in life. Studies in rodents have shown that stress experienced during early postnatal life can have lasting effects on brain development. Glucocorticoids and sex steroids are produced in endocrine glands and the brain from cholesterol; these molecules bind to nuclear and membrane-associated steroid receptors. Unlike other steroids that can also be made in the brain, neurosteroids bind specifically to neurotransmitter receptors, not steroid receptors. The relationships among steroids, neurosteroids, and stress are multifaceted and not yet fully understood. However, studies demonstrating altered levels of progestogens, androgens, estrogens, glucocorticoids, and their neuroactive metabolites in both developmental and adult stress paradigms strongly suggest that these molecules may be important players in stress effects on brain circuits and behavior. In this review, we discuss the influence of developmental and adult stress on various components of the brain, including neurons, glia, and perineuronal nets, with a focus on sex steroids and neurosteroids. Gaining an enhanced understanding of how early adversity impacts the intricate systems of brain steroid and neurosteroid regulation could prove instrumental in identifying novel therapeutic targets for stress-related conditions.

Rare forms of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders due to pathogenic variants in genes encoding enzymes and cofactors involved in adrenal steroidogenesis. Although 21-hydroxylase, 11β-hydroxylase, 3β-hydroxysteroid dehydrogenase type 2, 17α-hydroxylase/17,20-lyase, P450 oxidoreductase, steroidogenic acute regulatory protein, cholesterol side-chain cleavage enzyme deficiencies are considered within the definition of CAH, the term 'CAH' is often used to refer to '21-hydroxylase deficiency (21OHD)' since 21OHD accounts for approximately 95% of CAH in most populations. The prevalence of the rare forms of CAH varies according to ethnicity and geographical location. In most cases, the biochemical fingerprint of impaired steroidogenesis points to the specific subtypes of CAH, and genetic testing is usually required to confirm the diagnosis. Despite there are significant variations in clinical characteristics and management, most data about the rare CAH forms are extrapolated from 21OHD. This review article aims to collate the currently available data about the diagnosis and the management of rare forms of CAH.

Transcriptional Reprogramming of Candida tropicalis in Response to Isoespintanol Treatment

Candida tropicalis, an opportunistic pathogen, ranks among the primary culprits of invasive candidiasis, a condition notorious for its resistance to conventional antifungal drugs. The urgency to combat these drug-resistant infections has spurred the quest for novel therapeutic compounds, with a particular focus on those of natural origin. In this study, we set out to evaluate the impact of isoespintanol (ISO), a monoterpene derived from Oxandra xylopioides, on the transcriptome of C. tropicalis. Leveraging transcriptomics, our research aimed to unravel the intricate transcriptional changes induced by ISO within this pathogen. Our differential gene expression analysis unveiled 186 differentially expressed genes (DEGs) in response to ISO, with a striking 85% of these genes experiencing upregulation. These findings shed light on the multifaceted nature of ISO's influence on C. tropicalis, spanning a spectrum of physiological, structural, and metabolic adaptations. The upregulated DEGs predominantly pertained to crucial processes, including ergosterol biosynthesis, protein folding, response to DNA damage, cell wall integrity, mitochondrial activity modulation, and cellular responses to organic compounds. Simultaneously, 27 genes were observed to be repressed, affecting functions such as cytoplasmic translation, DNA damage checkpoints, membrane proteins, and metabolic pathways like trans-methylation, trans-sulfuration, and trans-propylamine. These results underscore the complexity of ISO's antifungal mechanism, suggesting that it targets multiple vital pathways within C. tropicalis. Such complexity potentially reduces the likelihood of the pathogen developing rapid resistance to ISO, making it an attractive candidate for further exploration as a therapeutic agent. In conclusion, our study provides a comprehensive overview of the transcriptional responses of C. tropicalis to ISO exposure. The identified molecular targets and pathways offer promising avenues for future research and the development of innovative antifungal therapies to combat infections caused by this pathogenic yeast.

Chalcone derivatives from licorice inhibit human and rat gonadal 3β-hydroxysteroid dehydrogenases as therapeutic uses

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine, licorice (the roots of Glycyrrhiza glabra and G. inflata) has been used to treat inflammation and sexual debility for over 1000 years. Pharmacological studies have identified many biologically active chalcone derivatives from licorice.

AIM OF THE STUDY

Human 3β-Hydroxysteroid dehydrogenase 2 (h3β-HSD2) catalyzes the formation of precursors for sex hormones and corticosteroids, which play critical roles in reproduction and metabolism. We explored inhibition and mode action of chalcones of inhibiting h3β-HSD2 and compared it with rat 3β-HSD1.

MATERIALS AND METHODS

We investigated the inhibition of 5 chalcones on h3β-HSD2 and compared species-dependent difference with 3β-HSD1.

RESULTS

The inhibitory strength on h3β-HSD2 was isoliquiritigenin (IC50, 0.391 μM) > licochalcone A (0.494 μM) > licochalcone B (1.485 μM) > echinatin (1.746 μM) >chalcone (100.3 μM). The inhibitory strength on r3β-HSD1 was isoliquiritigenin (IC50, 0.829 μM) > licochalcone A (1.165 μM) > licochalcone B (1.866 μM) > echinatin (2.593 μM) > chalcone (101.2 μM). Docking showed that all chemicals bind steroid and/or NAD+-binding site with the mixed mode. Structure-activity relationship analysis showed that strength was correlated with chemical's hydrogen bond acceptor.

CONCLUSION

Some chalcones are potent h3β-HSD2 and r3β-HSD1 inhibitors, possibly being potential drugs to treat Cushing's syndrome or polycystic ovarian syndrome.

Arbutin inhibits androgen biosynthesis by rat immature Leydig cells in vitro

Arbutin, a widely used skin lightening agent, has raised concerns regarding its potential side effects. In this study, we investigated the impact of arbutin on Leydig cell function using an in vitro model. We measured medium androgen levels, as well as the gene and protein expression related to Leydig cell steroidogenesis. Rat immature Leydig cells from age of 35 days were exposed to arbutin at concentrations ranging from 0.5 to 50 μM for a duration of 3 hrs. Following treatment, we observed a significant inhibition of androgen secretion by Leydig cells at both the 5 and 50 μM concentrations of arbutin. Furthermore, at a concentration of 50 μM, arbutin effectively blocked the stimulatory effects of luteinizing hormone (LH) and 8Br-cAMP on androgen secretion. Subsequent analysis revealed that arbutin downregulated the expression of crucial genes involved in androgen production, including Lhcgr, Hsd3b1, Cyp17a1, and Srd5a1. In silico computer program analysis predicted that arbutin exhibits good absorption, possesses a long elimination half-life, and may have other potential toxicity such as hepatoxicity. Taken together, our results demonstrate that arbutin negatively influences Leydig cell function and androgen production, potentially impacting male reproductive health.

Curcumin analogues exert potent inhibition on human and rat gonadal 3β-hydroxysteroid dehydrogenases as potential therapeutic agents: structure-activity relationship and in silico docking

Curcuminoids are functional food additives, and the effect on gonadal hormone biosynthesis remains unclear. Gonads contain 3β-hydroxysteroid dehydrogenase isoforms, h3β-HSD2 (humans) and r3β-HSD1 (rats), which catalyse pregnenolone into progesterone. The potency and mechanisms of curcuminoids to inhibit 3β-HSD activity were explored. The inhibitory potency was bisdemethoxycurcumin (IC₅₀, 1.68 µM) >demethoxycurcumin (3.27 µM) > curcumin (13.87 µM) > tetrahydrocurcumin (109.0 µM) > dihydrocurcumin and octahydrocurcumin on KGN cell h3β-HSD2, while that was bisdemethoxycurcumin (1.22 µM) >demethoxycurcumin (2.18 µM) > curcumin (4.12 µM) > tetrahydrocurcumin (102.61 µM) > dihydrocurcumin and octahydrocurcumin on testicular r3β-HSD1. All curcuminoids inhibited progesterone secretion by KGN cells under basal and forskolin-stimulated conditions at >10 µM. Docking analysis showed that curcuminoids bind steroid-active site with mixed or competitive mode. In conclusion, curcuminoids inhibit gonadal 3β-HSD activity and de-methoxylation of curcumin increases inhibitory potency and metabolism of curcumin by saturation of carbon chain losses inhibitory potency.

Risk assessment and environmental consequences of the use of the Allium-derived compound propyl-propane thiosulfonate (PTSO) in agrifood applications

The organosulfur compound propyl-propane thiosulfonate (PTSO), mainly found in Allium cepa, has a promising use in the agrifood industry. To confirm its safety for livestock, consumers, and environment, toxicological assessment is needed. In this regard, endocrine-disrupting chemicals (EDCs) are in the spotlight of research. Therefore, as part of the risk assessment of PTSO, in the present work, an in vivo study was performed in mice exposed to PTSO to investigate its potential reproductive toxicity considering fertility, genetic and endocrine endpoints. Five-weeks-old CD1 mice (80 males, 80 females) were exposed for 11 or 16 weeks (males or females, respectively) to different doses of PTSO (0, 14, 28 and 55 mg PTSO/kg b.w./day; 20 animals per group and sex) through the food pellets. No clinical observations or mortality and no changes in absolute organ weights and relative organ weights/body weight or brain ratios occurred during the study. The estrous cycle did not undergo any significant toxicologically relevant change. Most of the sex hormones displayed normal values. Some alterations in the expression of some genes related to reproduction is only observed in females, but they do not appear to have consequences in the development of sex organs. Docking results showed the impossibility of stable binding to estrogen and androgen receptors. Considering all the results obtained, the safe profile of PTSO can be confirmed for different agrifood applications at the conditions assayed.

Carbon chain length of perfluoroalkylated carboxylic acids determines inhibitory strength on gonadal 3β-hydroxysteroid dehydrogenases in humans, rats, and mice

Perfluoroalkylated carboxylic acids (PFCAs) are a subclass of man-made chemicals that have been widely used in industrial production and consumer products. As a result, PFCAs have been found to accumulate in the environment and bioaccumulate in organisms, leading to potential health and environmental impacts. This study investigated the inhibition of 11 PFCAs on gonadal 3β-hydroxysteroid dehydrogenases in humans, rats, and mice. We observed a V-shaped inhibition pattern against human granulosa (KGN) cell 3β-HSD2 starting from C9 (half-maximal inhibitory concentration, IC50, 100.8 μM) to C11 (8.92 μM), with a V-shaped turn. The same V-shaped inhibition pattern was also observed for PFCAs against rat testicular 3β-HSD1 from C9 (IC50, 50.43 μM) to C11 (6.60 μM). Mouse gonadal 3β-HSD6 was insensitive to the inhibition of PFCAs, with an IC50 of 50.43 μM for C11. All of these PFCAs were mixed inhibitors of gonadal 3β-HSDs. Docking analysis showed that PFCAs bind to the nicotinamide adenine dinucleotide (NAD+)/steroid binding sites of these enzymes and bivariate correlation analysis showed that molecular length determines the inhibitory pattern of PFCAs on these enzymes. In conclusion, the carbon chain length determines the inhibitory strength of PFCAs on human, rat, and mouse gonadal 3β-HSDs, and the inhibitory strength of PFCAs against human and rat 3β-HSD enzymes shows V-shaped turn.

Involvement of estrogen receptor alpha (ERα) and impairment of steroidogenesis after exposure to tris(2,3-dibromopropyl) isocyanurate (TBC) in mouse spermatogenic (GC-1 spg) cells in vitro

Good-quality reproductive cells are essential for reproduction. Endocrine disruptors are widely available in the environment and are known to have an adverse effect on spermatogenesis and steroidogenesis. One of them is tris(2,3-dibromopropyl) isocyanurate (TBC), i.e. one of the novel brominated flame retardants (NBFR). TBC is a widely distributed ingredient used in the production of flame retardants. Currently, it is known to affect the hormonal system, but the exact mechanism of its action is unknown. Therefore, the aim of the study was to determine whether TBC alone and in cotreatment with BHPI (estrogen receptor alpha antagonist) has an impact on the expression of nuclear receptors involved in the formation of steroid hormones, proteins, and enzymes responsible for steroidogenesis and the levels of steroid hormones (E2, P4, and T) in the GC-1 spg cell line as a mouse model of spermatogenic cells in vitro. Our results indicate that ERα is involved in the mechanism of TBC action, while no activation of PPARγ, AhR, and IGF-1R was observed. In addition, a decrease in the levels of most of the analyzed proteins and enzymes involved in steroid conversion was observed. Only Cyp19a1 was upregulated after TBC, BHPI, and TBC with BHPI cotreatment. In all the analyzed groups, a significant decrease in P4 and a subtle decrease in T and E2 were observed in the production and secretion of the hormones to the culture medium, compared to the control. The obtained results confirm the involvement of TBC in the dysregulation of steroid biosynthesis, which may affect male fertility.

Naringenin stimulates aromatase expression and alleviates the clinical and histopathological findings of experimental autoimmune encephalomyelitis in C57bl6 mice

This study was conducted to demonstrate the possible protective and therapeutic effects of naringenin, an estrogenically effective flavonoid, in experimental autoimmune encephalomyelitis (EAE), which is the rodent model of multiple sclerosis. For this purpose, 50 12-week-old C57BL6 male mice were divided into five groups; control, naringenin, EAE, prophylactic naringenin + EAE, and EAE + therapeutic naringenin. The EAE model was induced with myelin oligodendrocyte glycoprotein(35-55), and naringenin (50 mg/kg) was administered by oral gavage. The prophylactic and therapeutic effects of naringenin were examined according to clinical, histopathological, immunohistochemical, electron microscopic, and RT-PCR (aromatase, 3βHSD, estrogen receptors, and progesterone receptor expression) parameters. The acute EAE model was successfully induced, along with its clinical and histopathological findings. RT-PCR showed that expression of aromatase, 3βHSD, estrogen receptor-β, and progesterone receptor gene decreased, while estrogen receptor-α increased after EAE induction. Electron microscopic analysis showed mitochondrial damage and degenerative changes in myelinated axons and neurons in EAE, which could be behind the downregulation in the expressions of neurosteroid enzymes. Aromatase immunopositivity rates also decreased in EAE, while estrogen receptor α and β, and progesterone receptor immunopositivity rates increased. Naringenin improved aromatase immunopositivity rates and gene expression in both prophylactic and therapeutic use. Clinical and histopathological findings revealed that EAE findings were alleviated in both prophylactic and therapeutic groups, along with significantly decreased inflammatory cell infiltrations in the white matter of the spinal cords. In conclusion, naringenin could provide long-term beneficial effects even in prophylactic use due to stimulating aromatase expression, but it could not prevent or eliminate the EAE model's lesions completely.

Benzene ring bisphenol A substitutes potently inhibit human, rat, and mouse gonadal 3β-hydroxysteroid dehydrogenases: Structure-activity relationship and in silico docking analysis

Bisphenol A (BPA) is a chemical used in the production of certain plastics and resins. Recent research has found that BPA can inhibit the activity of 3β-hydroxysteroid dehydrogenase/Δ5,4-isomerases (3β-HSDs). Whether benzene ring BPA substitutes can inhibit human, rat, and mouse gonadal 3β-HSDs, the structure-activity relationship and the underlying mechanism remain unclear. In this study, we compared 6 benzene ring BPA substitutes to BPA in the inhibition of human, rat, and mouse gonadal 3β-HSDs and conducted structure-activity relationship and in silico docking analysis. The inhibitory activity (IC50) of human 3β-HSD2 in KGN cells ranged from about 0.02 μM for bisphenol H to 8.75 μM for BPA, that of rat 3β-HSD1 in testicular microsomes ranged from 0.099 μM for bisphenol H to 31.32 μM for BPA, and that of mouse 3β-HSD6 ranged from 0.021 μM for BPH to ineffectiveness for 100 μM BPA. These compounds acted as mixed inhibitors with LogP inversely correlated with IC50 and ΔG positively correlated with IC50 value. Docking analysis showed that these compounds bind to the steroid active site of the 3β-HSD enzymes. In conclusion, some benzene ring BPA substitutes potently inhibit gonadal 3β-HSD in various species, and lipophilicity and binding affinity determine their inhibitory strength.

Azole fungicides inhibit human and rat gonadal 3β-hydroxysteroid dehydrogenases: Structure-activity relationship and in silico docking analysis

Azole fungicides are widely used in the agricultural industry to control fungal infections in crops. However, recent studies have shown that some azole fungicides inhibit the activity of 3β-hydroxysteroid dehydrogenases (3β-HSDs) in the gonads. Out of the 16 azole fungicides tested, 8 were found to inhibit human KGN cell 3β-HSD2 with IC50 values of less than 100 μM. The strongest inhibitor was difenoconazole, with an IC50 value of 1.88 μM. In contrast, only 3 of the azole fungicides inhibited rat testicular 3β-HSD1, which was less sensitive to inhibition. Azole fungicides potently inhibited progesterone secretion by KGN cells under basal and forskolin stimulated conditions at ≥ 5 μM. The inhibitory strength of azole fungicides was determined by their lipophilicity (LogP), molecular weight, pKa, and binding energy. A pharmacophore analysis revealed that the hydrogen bond acceptor-lipid group was a critical feature required for inhibition. Overall, these findings suggest that the use of azole fungicides have unintended consequences on reproductive health due to their inhibition of gonadal 3β-HSDs. Key words: Azole fungicides; steroid hormones; 3β-hydroxysteroid dehydrogenase; docking analysis; lipophilicity.

Recent advances in age-related meibomian gland dysfunction (ARMGD)

Meibomian glands (MGs), located within the tarsal plate of the eyelid, secrete meibum which is the lipid-rich secretion necessary for stabilizing the tear film and preventing tear evaporation. Changes in the quality and quantity of meibum produced causes MG dysfunction (MGD), the leading cause of evaporative dry eye disease (EDED). MGD is an underdiagnosed disease and it is estimated that, in the US, approximately 70 % of the population over 60 have MGD. Three forms of MGD occur based on their meibum secretion: hyposecretory, obstructive, and hypersecretory MGD. The pathophysiology of MGD remains poorly understood, however aging is the primary risk factor. With age, MGs undergo various age-related changes, including decreased acinar basal cell proliferation, hyperkeratinization, MG atrophy, and eventual MG drop-out, leading to age-related MGD (ARMGD). Additionally, studies have suggested that MGs can suffer inflammatory cell infiltration and changes innervation patterns with aging, which could also contribute towards ARMGD. This review focuses on how the aging process affects the MG, and more importantly, how age-related changes to the MG can lead to MG atrophy and MG drop-out, ultimately leading to ARMGD. This review also highlights the most recent developments in potential therapeutic interventions for ARMGD.

Halogenated bisphenol A derivatives potently inhibit human, rat, and mouse gonadal 3β-hydroxysteroid dehydrogenases: Structure-activity relationship and in silico molecular docking analysis

Bisphenol A (BPA) is a widely used plastic material, and halogenated BPA derivatives are formed either by synthesis or environmental processes. However, the effect of halogenated bisphenols on steroidogenesis remains unclear. The aim of this study was to compare inhibition of 6 BPA derivatives on gonadal 3β-hydroxysteroid dehydrogenases (3β-HSDs) in three species (human, rat, and mouse). The inhibition on human 3β-HSD2 was tetrabromo BPA (TBBPA, IC50, 1.01 μM)>trichloro BPA (TrCBPA, 3.95 μM)>tetrachloro BPA (TCBPA, 4.14 μM)>monochloro BPA (MCBPA, 4.74 μM)>others with TrCBPA of competitive, TBBPA of noncompetitive and MCBPA/TCBPA of mixed inhibition. The inhibition on rat 3β-HSD1 was TCBPA (1.68 μM)>TrCBPA (1.72 μM)>MCBPA (2.80 μM)>BPA>others with mixed inhibition. The inhibition on mouse 3β-HSD6 was TrCBPA (1.59 μM) >MCBPA (3.36 μM)>TCBPA (3.72 μM)>others with mixed inhibition. Molecular docking analysis showed that TBBPA, TrCBPA, and TCBPA bind to steroid active sites, contacting with catalytic residue Tyr154 of human 3β-HSD2. MCBPA, TrCBPA, and TCBPA bind to steroid active site of rat 3β-HSD1. MCBPA and TrCBPA bind to active site of mouse 3β-HSD6. Regression of lowest binding energy values with Ki values revealed a significant negative linear regression (P < 0.05). In conclusion, halogenated BPA derivatives are more potent inhibitors of three 3β-HSDs than BPA and there is structure-dependent inhibition. SYNOPSIS: Chlorinated bisphenol derivatives after water chlorination process and other halogenated bisphenols effectively inhibit human and rat 3β-HSD activity, thereby leading to steroid hormone deficiency.

Luteal Lipid Droplets: A Novel Platform for Steroid Synthesis

Progesterone is an essential steroid hormone that is required to initiate and maintain pregnancy in mammals and serves as a metabolic intermediate in the synthesis of endogenously produced steroids, including sex hormones and corticosteroids. Steroidogenic luteal cells of the corpus luteum have the tremendous capacity to synthesize progesterone. These specialized cells are highly enriched with lipid droplets that store lipid substrate, which can be used for the synthesis of steroids. We recently reported that hormone-stimulated progesterone synthesis by luteal cells requires protein kinase A-dependent mobilization of cholesterol substrate from lipid droplets to mitochondria. We hypothesize that luteal lipid droplets are enriched with steroidogenic enzymes and facilitate the synthesis of steroids in the corpus luteum. In the present study, we analyzed the lipid droplet proteome, conducted the first proteomic analysis of lipid droplets under acute cyclic adenosine monophosphate (cAMP)-stimulated conditions, and determined how specific lipid droplet proteins affect steroidogenesis. Steroidogenic enzymes, cytochrome P450 family 11 subfamily A member 1 and 3 beta-hydroxysteroid dehydrogenase (HSD3B), were highly abundant on lipid droplets of the bovine corpus luteum. High-resolution confocal microscopy confirmed the presence of active HSD3B on the surface of luteal lipid droplets. We report that luteal lipid droplets have the capacity to synthesize progesterone from pregnenolone. Lastly, we analyzed the lipid droplet proteome following acute stimulation with cAMP analog, 8-Br-cAMP, and report increased association of HSD3B with luteal lipid droplets following stimulation. These findings provide novel insights into the role of luteal lipid droplets in steroid synthesis.

Identification of a novel candidate HSD3B2 gene variant for familial hypospadias by whole-exome sequencing

Introduction: Hypospadias [MIM: 300633] is one of the most frequent congenital malformations of male external genitalia. The spectrum of genetic variants causing hypospadias is varied, with studies commonly implicating genes critical in the fetal steroidogenic pathway. This is the first genetic study on hypospadias from the Yemen ethnicity and the second to report HSD3B2 mutations in more than one affected individual from the same family. Material and methods: Surgical hypospadias repair was performed on two hypospadias-affected siblings from a consanguineous family. Whole-exome sequencing (WES) was performed to identify the potential pathogenic variant for hypospadias, which was later confirmed by Sanger sequencing. The identified variant was further analyzed for its pathogenicity by using in silico tools such as SIFT, PolyPhen-2, MutationAssessor, MutationTaster, FATHMM, and ConSurf. Results: We identified a novel missense mutation (Chr1:119964631T>A, c.507T>A, p. N169K) in 3β-hydroxysteroid 2-dehydrogenase (HSD3B2) gene by WES. Sanger sequencing confirmed that the variant segregated the disease in the family between the affected and non-affected individuals. Both patients are homozygous, while parents and two unaffected siblings are heterozygous carriers, indicating an autosomal recessive pattern of inheritance. The in silico analysis by all six in silico tools (SIFT, PolyPhen-2, MutationAssessor, MutationTaster, FATHMM, and ConSurf) predicted the variant to be pathogenic/deleterious. Discussion: An abnormal fetal steroidogenic pathway due to genetic influences may affect the development of the male genital tract, including the urethral tract closure and morphogenesis of male genitalia. Furthermore, the pathogenicity of the observed variant in this study, confirmed by multiple in silico tools, characterizes the influence HSD3B2 gene variants may have in the etiology of hypospadias. Conclusion: Understanding of pathogenic manifestation and inheritance of confounding genetic variants in hypospadias is a matter of great concern, especially in familial cases.

Benzophenone-type ultraviolet filters inhibit human and rat placental 3β-hydroxysteroid dehydrogenases: structure-activity relationship and in silico docking analysis

Benzophenones (BPs) are a class of chemicals found in various personal care and cosmetic products, such as sunscreens and lotions. Their usage is known to cause reproductive and hormonal health risks, but the exact mechanism of action remains unknown. In this study, we investigated the effect of BPs on human and rat placental 3β-hydroxysteroid dehydrogenases (3β-HSDs), which play a crucial role in the biosynthesis of steroid hormones, particularly progesterone. We tested inhibitory effects of 12 BPs, and performed structure-activity relationship (SAR) and in silico docking analysis. The potency of BPs to inhibit human 3β-HSD1 (h3β-HSD1) is BP-1 (IC₅₀, 8.37 μM)>BP-2 (9.06 μM)>BP-12 (94.24 μM)>BP-7 (1160 μM) >BP-6 (1257 μM) >BP-6 (1410 μM) > other BPs (ineffective at 100 μM). The potency of BPs on rat r3β-HSD4 is BP-1 (IC₅₀, 4.31 μM)>BP-2 (117.3 μM)>BP-6 (669 μM) >BP-3 (820 μM)>other BPs (ineffective at 100 μM). BP-1, BP-2, and BP-12 are mixed h3β-HSD1 inhibitors and BP-1 is a mixed r3β-HSD4 inhibitor. LogP, lowest binding energy, and molecular weight were positively associated with IC₅₀ for h3β-HSD1, while LogS was negatively associated with IC₅₀. The 4-OH substitution in the benzene ring play a key role in enhancing the effectiveness of inhibiting h3β-HSD1 and r3β-HSD4, possibly through increasing water solubility and decreasing lipophilicity by forming hydrogen bonds. BP-1 and BP-2 inhibited progesterone production in human JAr cells. Docking analysis shows that 2-OH of BP-1 forms hydrogen bond with catalytic residue Ser125 of h3β-HSD1 and Thr125 of r3β-HSD4. In conclusion, this study demonstrates that BP-1 and BP-2 are moderate inhibitors of h3β-HSD1 and BP-1 is moderate inhibitor of r3β-HSD4. There is a significant SAR difference for 3β-HSD homologues between BPs and distinct species-dependent inhibition of placental 3β-HSDs.

Overlapping representations of food and social stimuli in VTA dopamine neurons

Dopamine neurons of the ventral tegmental area (VTA DA ) respond to food and social stimuli and contribute to both forms of motivation. However, it is unclear if the same or different VTA DA neurons encode these different stimuli. To address this question, we performed 2-photon calcium imaging in mice presented with food and conspecifics, and found statistically significant overlap in the populations responsive to both stimuli. Both hunger and opposite-sex social experience further increased the proportion of neurons that respond to both stimuli, implying that modifying motivation for one stimulus affects responses to both stimuli. In addition, single-nucleus RNA sequencing revealed significant co-expression of feeding- and social-hormone related genes in individual VTA DA neurons. Taken together, our functional and transcriptional data suggest overlapping VTA DA populations underlie food and social motivation.

High carrier frequency of a nonsense p.Trp230* variant in HSD3B2 gene in Ossetians

Background

Congenital adrenal hyperplasia (CAH) caused by 3β-HSD deficiency is a rare form of congenital adrenal deficiency with an autosomal recessive type of inheritance. Previously we have demonstrated that a single nucleotide variant (SNV) p.Trp230* in the homozygous state is a frequent cause of CAH among the indigenous population of North Ossetia-Alania represented by Ossetians.

Methods

Genotyping of the NM_000198.3:c.690G>A p.Trp230* variant was performed by Real-time PCR. 339 healthy individuals of Ossetian origin were included in the study. Allele frequencies, Fisher's confidence intervals (CI) were calculated using the WinPepi v. 11.65 software. Comparison of allele frequencies was performed with the z-score test for two proportions.

Results

Eight heterozygous carriers of c.690G>A variant in HSD3B2 gene were detected in 339 samples investigated. The total allele frequency of p.Trp230* variant was 0.0118 (n=8/678, 95% CI=0.0051-0.0231). Accordingly, the heterozygous carrier rate was 0.0236 (n=8/339). The frequency of CAH caused by p.Trp230* variant in HSD3B2 in Ossetian population was 1:7183 or 13.9 per 100,000 (95% CI: 1:1874-1:38447 or 3-53 per 100,000).

Conclusion

The results demonstrate high frequency of p.Trp230* variant in Ossetians, which is most likely attributed to a founder effect.

Inhibition of Resveratrol Analogs on Human and Rat 3β-Hydroxysteroid Dehydrogenases: Structure-Activity Relationship and Docking Analysis

Resveratrol and its analogs are phytochemicals. Human 3β-hydroxysteroid dehydrogenase 1 (3β-HSD1) synthesizes steroid hormones for normal pregnancy or promoting cancer metastasis. Whether they inhibit 3β-HSD1 remains unclear. In this study, the inhibitory potency, mode of action, structure-activity relationship, and docking parameters of resveratrol and its analogs on 3β-HSD1 and rat homolog 3β-HSD4 were analyzed. The inhibitory potency of these chemicals on human 3β-HSD1 was 4,4'-dihydroxystilbene (IC₅₀, 3.68 μM) > pinostilbene (8.07 μM) > pinosylvin (10.60 μM) > lunularin (26.84 μM) > resveratrol (30.20 μM) > dihydroresveratrol (>100 μM) = oxyresveratrol (>100 μM) > dihydropinosylvin (ineffective at 100 μM). Resveratrol analogs and metabolites are mixed or competitive inhibitors of human 3β-HSD1. Resveratrol and 4,4'-dihydroxystilbene inhibited progesterone secretion by human JAr cells at ≥1 μM. Resveratrol (IC₅₀, 32.09 μM) and pinosylvin (34.71 μM) significantly inhibited rat placental 3β-HSD4 activity. Docking analysis shows that resveratrol analogs and metabolites bind the steroid-binding sites of human 3β-HSD1 and rat 3β-HSD4 and interact with the catalytic residues Ser125/Thr125 and Tyr155. The negative correlation of LogP and IC₅₀ values for human 3β-HSD1 indicates that lipophilicity of chemicals plays a critical role in the inhibitory effect of chemicals. In conclusion, 4,4'-dihydroxystilbene, pinostilbene, and pinosylvin effectively inhibit human 3β-HSD1 depending on their lipophilicity, thereby acting as potential therapeutic agents.

Approaches to assessing 3β-hydroxysteroid dehydrogenase-1

The enzyme 3β-hydroxysteroid dehydrogenase-1 (3βHSD1), encoded by the gene HSD3B1, plays an essential role in the peripheral conversion of 3β-OH, Δ5-steroids to 3-keto, Δ4-steroids. In human physiology, the adrenal produces dehydroepiandrosterone (DHEA) and DHEA-sulfate, which are major precursors for the biosynthesis of potent androgens and estrogens. DHEA is converted by 3βHSD1 and subsequently is converted by steroid-5α-reductase to potent androgens or by aromatase to estrogens. Assessment of 3βHSD1 is therefore critical under various conditions. In this chapter, we detail several approaches to assessing 3βHSD1. First, we describe a genotyping protocol for the identification of a common missense-encoding variation that regulates 3βHSD1 cellular metabolic activity. This protocol distinguishes between the HSD3B1(1245A) and the HSD3B1(1245C) allele which have lower and higher metabolic activity, respectively. Second, we detail mass spectrometry approaches to determining 3βHSD1 activity using stable isotope dilution. Third, we describe methods for using tritiated DHEA and high performance liquid chromatography coupled with a beta-RAM to also determine 3βHSD1 activity. Together, we provide multiple methods of directly assessing 3βHSD1 activity or anticipated 3βHSD1 activity.

Curcuminoids inhibit human and rat placental 3β-hydroxysteroid dehydrogenases: Structure-activity relationship and in silico docking analysis

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine, curcuma longa L has been applied to treat pain and tumour-related symptoms for over thousands of years. Curcuminoids, polyphenolic compounds, are the main pharmacological component from the rhizome of Curcuma longa L. Pharmacological investigations have found that curcuminoids have many pharmacological activities of anti-inflammatory, anti-tumour, and anti-metastasis.

AIM OF THE STUDY

3β-Hydroxysteroid dehydrogenase (3β-HSD1) catalyses the production of steroid precursors for androgens and estrogens, which play an essential role in cancer metastasis. We explored the potency and mode of action of curcuminoids and their metabolites of inhibiting 3β-HSD1 activity and compared the species difference between human and rat.

MATERIALS AND METHODS

In this study, we investigated the direct inhibition of 6 curcuminoids on human placental 3β-HSD1 activity and compared the species-dependent difference in human 3β-HSD1 and rat placental homolog 3β-HSD4.

RESULTS

The inhibitory potency of curcuminoids on human 3β-HSD1 was demethoxycurcumin (IC₅₀, 0.18 μM) > bisdemethoxycurcumin (0.21 μM)>curcumin (2.41 μM)> dihydrocurcumin (4.13 μM)>tetrahydrocurcumin (15.78 μM)>octahydrocurcumin (ineffective at 100 μM). The inhibitory potency of curcuminoids on rat 3β-HSD4 was bisdemethoxycurcumin (3.34 μM)>dihydrocurcumin (5.12 μM)>tetrahydrocurcumin (41.82 μM)>demethoxycurcumin (88.10 μM)>curcumin (137.06 μM)> octahydrocurcumin (ineffective at 100 μM). Human choriocarcinoma JAr cells with curcuminoid treatment showed that these chemicals had similar potency to inhibit progesterone secretion under basal and 8bromo-cAMP stimulated conditions. Docking analysis showed that all chemicals bind pregnenolone-binding site with mixed/competitive mode for 3β-HSD.

CONCLUSION

Some curcuminoids are potent human placental 3β-HSD1 inhibitors, possibly being potential drugs to treat prostate cancer and breast cancer.

The analysis of pesticides and fungicides in the inhibition of human and rat placental 3β-hydroxysteroid dehydrogenase activity: mode of inhibition and mechanism

3β-Hydroxysteroid dehydrogenase/steroid Δ^5,4-isomerase 1 (3β-HSD1) plays a critical role in the biosynthesis of progesterone from pregnenolone in the human placenta to maintain normal pregnancy. Whether they inhibit placental 3β-HSD1 and mode of inhibition remains unclear. In this study, we screened 21 pesticides and fungicides in five classes to inhibit human 3β-HSD1 and compared them to rat homolog 3β-HSD4. 3β-HSD activity was measured by catalyzing pregnenolone to progesterone in the presence of NAD⁺. Of the 21 chemicals, azoles (difenoconazole), thiocarbamates (thiram and ferbam) and organochlorine (hexachlorophene) significantly inhibited human 3β-HSD1 with half maximal inhibitory concentration (IC₅₀) values of 2.77, 0.24, 0.68, and 17.96 μM, respectively. We also found that difenoconazole, ferbam and hexachlorophene are mixed/competitive inhibitors of 3β-HSD1 while thiram is a mixed/noncompetitive inhibitor. Docking analysis showed that difenoconazole and hexachlorophene bound steroid-binding site. Difenoconazole and hexachlorophene except thiram and ferbam also significantly inhibited rat 3β-HSD4 activity with IC₅₀ of 1.12 and 2.28µM, respectively. Thiram and ferbam significantly inhibited human 3β-HSD1 possibly by interfering with cysteine residues, while they had no effects on rat 3β-HSD4. In conclusion, some pesticides potently inhibit placental 3β-HSD, leading to the reduction of progesterone formation.

Benzophenone-1 and -2 UV-filters potently inhibit human, rat, and mouse gonadal 3β-hydroxysteroid dehydrogenases: Structure-activity relationship and in silico docking analysis

Benzophenone (BP) ultraviolet (UV) -filters have been widely used to prevent adverse effects of UV. Whether they can disrupt gonadal steroidogenesis remains unclear. Gonadal 3β-hydroxysteroid dehydrogenases (3β-HSD) catalyse the conversion of pregnenolone to progesterone. This study explored the effect of 12 BPs on human, rat, and mouse 3β-HSD isoforms, and analysed the structure-activity relationship (SAR) and underlying mechanisms. The inhibitory potency was BP-1 (IC₅₀, 5.66 ± 0.95 μM) > BP-2 (5.84 ± 2.22 μM) > BP-6 (185.8 ± 115.2 μM) > BP3-BP12 on human KGN 3β-HSD2, BP-2 (5.90 ± 1.02 μM) > BP-1 (7.55 ± 1.26 μM) > BP3-B12 on rat testicular 3β-HSD1, and BP-1 (15.04 ± 5.20 μM) > BP-2 (22.64 ± 11.81 μM) > BP-6（125.1 ± 34.65 μM）> BP-7 (161.1 ± 102.4 μM) > other BPs on mouse testicular 3β-HSD6. BP-1 is a mixed inhibitor of human, rat, and mouse 3β-HSDs, and BP-2 is a mixed inhibitor of human and rat 3β-HSDs and a noncompetitive inhibitor of mouse 3β-HSD6. 4-Hydroxyl substitution in the benzene ring plays a key role in enhancing potency of inhibiting human, rat, and mouse gonadal 3β-HSDs. BP-1 and BP-2 can penetrate human KGN cells to inhibit progesterone secretion at ≥ 10 μM. Docking analysis revealed that the 4-hydroxyl group of BP-1 and BP-2 forms hydrogen bonds with residue Ser123 of human 3β-HSD2 and residue Asp127 of rat 3β-HSD1. In conclusion, this study demonstrates that BP-1 and BP-2 are the most potent inhibitors of human, rat, and mouse gonadal 3β-HSDs and that there is a significant SAR difference.

Steroid hormone signaling: What we can learn from insect models

Ecdysteroids are a group of steroid hormones in arthropods with pleiotropic functions throughout their life history. Ecdysteroid research in insects has made a significant contribution to our current understanding of steroid hormone signaling in metazoans, but how far can we extrapolate our findings in insects to other systems, such as mammals? In this chapter, we compare steroid hormone signaling in insects and mammals from multiple perspectives and discuss similarities and differences between the two lineages. We also highlight a few understudied areas and remaining questions of steroid hormone biology in metazoans and propose potential future research directions.

History of Adrenal Research: From Ancient Anatomy to Contemporary Molecular Biology

The adrenal is a small, anatomically unimposing structure that escaped scientific notice until 1564 and whose existence was doubted by many until the 18th century. Adrenal functions were inferred from the adrenal insufficiency syndrome described by Addison and from the obesity and virilization that accompanied many adrenal malignancies, but early physiologists sometimes confused the roles of the cortex and medulla. Medullary epinephrine was the first hormone to be isolated (in 1901), and numerous cortical steroids were isolated between 1930 and 1949. The treatment of arthritis, Addison's disease, and congenital adrenal hyperplasia (CAH) with cortisone in the 1950s revolutionized clinical endocrinology and steroid research. Cases of CAH had been reported in the 19th century, but a defect in 21-hydroxylation in CAH was not identified until 1957. Other forms of CAH, including deficiencies of 3β-hydroxysteroid dehydrogenase, 11β-hydroxylase, and 17α-hydroxylase were defined hormonally in the 1960s. Cytochrome P450 enzymes were described in 1962-1964, and steroid 21-hydroxylation was the first biosynthetic activity associated with a P450. Understanding of the genetic and biochemical bases of these disorders advanced rapidly from 1984 to 2004. The cloning of genes for steroidogenic enzymes and related factors revealed many mutations causing known diseases and facilitated the discovery of new disorders. Genetics and cell biology have replaced steroid chemistry as the key disciplines for understanding and teaching steroidogenesis and its disorders.

Inhibition of human and rat placental 3β-hydroxysteroid dehydrogenase/Δ5,4-isomerase activities by insecticides and fungicides: Mode action by docking analysis

Many insecticides and fungicides are endocrine-disrupting compounds, which possibly interfere with the placental endocrine system. In the placenta, 3β-hydroxysteroid dehydrogenase/Δ^5,4-isomerase type 1 (HSD3B1) is the major steroidogenic enzyme, which makes progesterone from pregnenolone to support the placental stability. In this study, we screened 12 classes of insecticides and fungicides to inhibit placental HSD3B1 activity and compared them to the rat homolog type 4 (HSD3B4) isoform. Human HSD3B1 activity and rat HSD3B4 activity were measured in the presence of 200 nM pregnenolone and 0.2 mM NAD⁺ and 100 μM of test chemical. Triclosan, triflumizole, dichlone, and oxine at 100 μM significantly inhibited human HSD3B1 activity with the residual activity being less than 50% of the control. Further study showed that the half-maximal inhibitory concentration (IC₅₀) values of triclosan, triflumizole, dichlone, and oxine were 85.53 ± 9.14, 73.75 ± 3.42, 2.54 ± 0.40, and 102.93 ± 6.10 μM, respectively. In the presence of pregnenolone, triclosan, triflumizole, and dichlone were mixed inhibitors of HSD3B1, while oxine was a noncompetitive inhibitor. In the presence of NAD⁺, triclosan exhibited competitive inhibition while triflumizole possessed uncompetitive inhibition. Docking analysis showed that triclosan bound NAD⁺-binding site, while triflumizole, dichlone, and oxine mostly bound steroid-binding site. When the effect of these insecticides on rat placental HSD3B4 activity was screened in the presence of 200 nM pregnenolone, atrazine, triclosan, triflumizole, oxine, cyprodinil, and diphenyltin at 100 μM significantly inhibited rat HSD3B4 activity, with IC₅₀ values of triclosan, triflumizole, oxine, and cyprodinil were 82.99 ± 6.48, 35.45 ± 2.73, 105.59 ± 12.04, and 43.37 ± 3.00 μM, respectively. The mode action analysis showed that triflumizole and cyprodinil were almost competitive inhibitors, while triclosan and oxine were almost noncompetitive inhibitors of rat HSD3B4. Docking analysis showed that triclosan and oxine bound cofactor NAD⁺ binding residues more than steroid-binding residues of rat HSD3B4 while triflumizole and cyprodinil bound most pregnenolone-interactive residues. In conclusion, some insecticides such as triclosan, triflumizole, and oxine can effectively inhibit both human and rat placental HSD3B activity and they have unique mode action due to the structure difference.

Effects of phenolic compounds on 3β-hydroxysteroid dehydrogenase activity in human and rat placenta: Screening, mode of action, and docking analysis

Human 3β-hydroxysteroid dehydrogenase type I (HSD3B1) and rat type IV (HSD3B4) in placentas catalyze the conversion of pregnenolone to progesterone, which plays a key role in maintaining pregnancy. Many phenolic compounds potentially inhibit HSD3B in placentas as endocrine disruptors. In this study, the effects of 16 phenolic compounds on the activity of human HSD3B1 and rat HSD3B4 were determined and the structure-activity relationship was compared. HSD3B1 in human placental microsomes and HSD3B4 in rat placental microsomes were used to measure their activities and pregnenolone and NAD⁺ were used as substrates. Of the 16 phenolic compounds, 4-nonylphenol, pentabromophenol, and 2-bromophenol resulted in residual human HSD3B1 activity lower than 50 % and 4-nonylphenol and pentabromophenol resulted in residual rat HSD3B4 activity lower than 50 %. 4-Nonylphenol, pentabromophenol, and 2-bromophenol were mixed inhibitors of human HSD3B1, with Ki values of 2.31, 3.58 and 4.86 µM, respectively, while 4-nonylphenol and pentabromophenol were noncompetitive inhibitors of rat HSD3B4 with Ki values of 20.86 and 141.8 µM. Molecular docking showed that 4-nonylphenol, pentabromophenol, and 2-bromophenol docked to the active sites of human HSD3B1 and rat HSD3B4, and the shift of residue S125 in human HSD3B1 to T125 in rat HSD3B4 could explain the species-dependent difference in their inhibitory potency and mode of action. This study demonstrates that 4-nonylphenol, pentabromophenol, and 2-bromophenol are mixed inhibitors of human placental HSD3B1, while 4-nonylphenol and pentabromophenol are noncompetitive inhibitors of rat HSD3B4, possibly blocking the placental steroidogenesis.

Environmentally relevant uptake, elimination, and metabolic changes following early embryonic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in zebrafish

Dioxin and dioxin-like compounds are ubiquitous environmental contaminants that induce toxicity by binding to the aryl hydrocarbon receptor (AHR), a ligand activated transcription factor. The zebrafish model has been used to define the developmental toxicity observed following exposure to exogenous AHR ligands such as the potent agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin, TCDD). While the model has successfully identified cellular targets of TCDD and molecular mechanisms mediating TCDD-induced phenotypes, fundamental information such as the body burden produced by standard exposure models is still unknown. We performed targeted gas chromatography (GC) high-resolution mass spectrometry (HRMS) in tandem with non-targeted liquid chromatography (LC) HRMS to quantify TCDD uptake, model the elimination dynamics of TCDD, and determine how TCDD exposure affects the zebrafish metabolome. We found that 50 ppt, 10 ppb, and 1 ppb waterborne exposures to TCDD during early embryogenesis produced environmentally relevant body burdens: 38 ± 4.34, 26.6 ± 1.2, and 8.53 ± 0.341 pg/embryo, respectively, at 24 hours post fertilization. TCDD exposure was associated with the dysregulation of metabolic pathways that are associated with the AHR signaling pathway as well as pathways shown to be affected in mammals following TCDD exposure. In addition, we discovered that TCDD exposure affected several metabolic pathways that are critical for brain development and function including glutamate metabolism, chondroitin sulfate biosynthesis, and tyrosine metabolism. Together, these data demonstrate that existing exposure methods produce environmentally relevant body burdens of TCDD in zebrafish and provide insight into the biochemical pathways impacted by toxicant-induced AHR activation.

Co-Occurrence of a Pathogenic HSD3B2 Variant and a Duplication on 10q22.3-q23.2 Detected in Newborn Twins with Salt-Wasting Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders caused by enzyme deficiencies required for cortisol biosynthesis in the adrenal cortex. The majority of CAH are due to the deficiency of the 21-hydroxylase enzyme, while 3β-hydroxysteroid dehydrogenase type 2 deficiency accounts for less than five percent of all CAH cases. We report two Moroccan twins from a spontaneous triplet pregnancy. The 46,XY newborn exhibited a disorder of sexual differentiation (DSD) with hypo virilization, while the 46,XX newborn had normal female external genitalia. In the first week of life, they showed hyponatremia and primary adrenal insufficiency with a slight 17OHP elevation and increased DHEAS and renin levels. The aCGH-SNP analysis disclosed a 8.36 Mb long contiguous stretch of homozygosity (LCSH) on chromosome 1p13.2-p11.2 including the candidate HSD3B2 gene, a LCSH of 7.3 Mb on 14q31.1-q32.11, and a 7 Mb duplication on 10q22.3-q23.2. Clinical exome sequencing revealed the biallelic c.969T > G (p.Asn323Lys) HSD3B2, likely pathogenic, variant in both of the affected twins. This case emphasizes the importance of a prompt molecular diagnosis performed through the combination of aCGH and clinical exome, both for establishment of correct therapy and for follow-up, as the newborns also carry a genomic rearrangement with possible clinical implications.

HSD3B1 Expression Is Upregulated by Interleukin 4 in HT-29 Colon Cancer Cells via Multiple Signaling Pathways

3β-Hydroxysteroid dehydrogenase/isomerase is essential for the synthesis of active steroid hormones. Interleukin 4 (IL4) induces the expression of HSD3B1 in various human cancer cell lines. Here, we demonstrated that administration of IL4 to an HT-29 colon cancer cell line induced high expression of HSD3B1 at the mRNA and protein levels. In the HT-29 cells, IL4 stimulated the activity of signal transducer and activator of transcription 6 (STAT6) and promoted its binding to the STAT6-binding site in the HSD3B1 promoter. The STAT6 inhibitor significantly suppressed HSD3B1 induction by IL4 in a dose-dependent manner. Moreover, inhibition of the PI3-kinase/AKT pathway strongly suppressed the IL4-induced HSD3B1 expression. Glycogen synthase kinase 3 (GSK3), a downstream target of AKT, had a stimulatory effect on the IL4-induced HSD3B1 expression. However, IL4 stimulated the phosphorylation of AKT, which inhibited the GSK3 activity at the early stage. Hence, GSK3 potentiated the HSD3B1 levels at the late stage of the IL4 stimulation. Additionally, inhibitors of mitogen-activated protein kinases (MAPKs), ERK1/2 and p38, but not of JNK, partly reduced the HSD3B1 expression following the IL4 stimulation. We further demonstrated that IL4 potently promoted steroid synthesis. Our results indicate that IL4 induces HSD3B1 expression via multiple signaling pathways in HT-29 cells and may play a role in the regulation of steroid synthesis.

Genetic Testing for a Patient with Suspected 3 Beta-Hydroxysteroid Dehydrogenase Deficiency: A Case of Unreported Genetic Variants

3beta-hydroxysteroid dehydrogenase type II deficiency (HSD3B2 deficiency), a rare form of congenital adrenal hyperplasia (CAH), is characterized by varying degrees of salt loss and incomplete masculinization in males and mild virilization or normal external genitalia in females. We report the case of a patient (46XY) showing salt loss and incomplete masculinization, markedly elevated levels of 17OHP (17 hydroxyprogesterone), ACTH (Adreno Cortico Tropic Hormone), testosterone and delta4androstenedione (delta4A), low levels of cortisol and absence of bone skeletal alterations that frequently characterize POR (Cytochrome P450 oxidoreductase) deficiency. Mutation analysis by Sanger sequencing of the HSD3B2 gene showed that the patient presented with a compound heterozygote for two novel variants c.370A>G p.Ser124Gly and c.308-6 G>A. The two HSD3B2 gene variants were also present in the patient’s older brother showing only incomplete masculinization. The in silico analysis revealed a probable damaging effect of c.370A>G p.Ser124Gly: residue p.Ser124 is highly conserved among species and seems to be located in the catalytic site of the enzyme, playing a pivotal role in NAD(H) binding to its substrate. Intronic c.308-6G>A variant is predicted to be likely pathogenic; the substitution seems to cause a change in the splice acceptor site located 6bp downstream of the variant. The two siblings seem to be affected by 3β-HSD2 deficiency; nevertheless, the two novel variants are likely to cause variable expressivity of the disease.

The Efficacy of a 3β-Hydroxysteroid Dehydrogenase Inhibitor for the Termination of Mid-Term Pregnancies in Dogs

Simple Summary

The medical termination of unwanted pregnancies in dogs is practiced throughout the world for many reasons, including at the request of animal owners. For these procedures, it is advised to use rapidly effective drugs with minimal side effects. In this study, we investigated trilostane, which decreases progesterone levels, for its efficacy in terminating mid-term pregnancies in dogs, as well as potential side effects. Although trilostane is not a standalone alternative for the termination of pregnancy in dogs, it has been determined that its combined use with another medical agent of known efficacy reduces both the abortion time and potential side effects. Further studies investigating an increased frequency of administration rather than the administration dose could contribute to determining the efficacy of trilostane in dogs.

Abstract

Progesterone (P4) is the only hormone needed to maintain pregnancy in dogs. Therefore, a competitive inhibitor of 3β-hydroxysteroid dehydrogenase (3β-HSD) could be a safe and effective option to terminate pregnancy by inhibiting P4 synthesis. To address this hypothesis, we investigated the efficacy of trilostane (TRL), a competitive inhibitor of 3β-HSD, in terminating pregnancy in dogs. Twenty-one dogs between days 30 and 38 of pregnancy were randomly assigned to one of two treatment groups (trilostane (TRL) and aglepristone (AGL)) and an untreated control (CON) group (n = 7 dogs each). Fetal heart rates (FHRs) (measured at 12 h intervals) and serum P4 concentrations (measured at 6 h intervals) were evaluated. The pregnancy termination rates were 0% and 100% in the TRL and AGL groups, respectively. The decrease in the FHR in the TRL and AGL groups was significantly lower than that observed in the CON group. There was a marked decrease in P4 concentrations in the TRL group 6, 54, and 102 h after the initiation of treatment. The luteal expression of StAR appeared to be weaker in the AGL group than the CON group. In conclusion, although a treatment-induced decrease was observed in plasma P4 concentrations, a seven-day TRL treatment alone was not effective in terminating pregnancies. Further studies are needed on the effects of the prolonged administration of TRL with varying doses and frequencies for the termination of mid-term pregnancy in dogs.

Structure-activity relationship analysis of perfluoroalkyl carbonic acids on human and rat placental 3β-hydroxysteroid dehydrogenase activity

Placenta contains 3β-hydroxysteroid dehydrogenase/steroid Δ^5,4-isomerase (HSD3B), which catalyzes pregnenolone to progesterone for maintaining pregnancy. Perfluoroalkyl carbonic acids (PFC) are subclass of perfluoroalkyl substances containing 4-14 carbons (C4-C14) in the carbon backbone and are potential endocrine disruptors. Whether PFC inhibit HSD3B and structure-activity relationship (SAR) remains unclear. Herein, we screened 11 PFC for inhibiting human type I HSD3B (HSD3B1) and rat type IV HSD3B (HSD3B4) activities and determined SAR and mode of inhibition. HSD3B was measured by converting pregnenolone to progesterone assisted by NAD⁺ in placental microsomes. Of the 11 PFC, C9-C14 significantly inhibited human HSD3B1 activity at 100 μM. Half-maximal inhibitory concentration (IC₅₀) values of C9-C14 compounds were 363.56 ± 12.14, 12.78 ± 0.69, 6.54 ± 0.65, 20.88 ± 0.41, 118.35 ± 0.16, and 149.26 ± 21.67 μM, respectively. We determined Ki values and mode of inhibition of three most potent PFC (C10-C12), and found that they were mixed inhibitors against pregnenolone, with Ki values of 5.57 ± 4.37, 2.04 ± 2.26, and 9.93 ± 7.71, respectively. Docking analysis showed that they bound steroid-binding site. Effects of PFC on rat placental HSD3B4 were performed. Of the 11 PFC, C10-C12 significantly inhibited rat HSD3B4 activity at 100 μM. IC₅₀ values of C10-C12 compounds were 45.85 ± 1.49, 36.08 ± 1.50, and 88.74 ± 1.99 µM, respectively. Ki values and inhibition modes of the three most potent PFC (C10-C12) were studied. It was found that they were mixed inhibitors against pregnenolone, with Ki values of 48.16 ± 20.44, 36.28 ± 53.07, and 91.79 ± 21.75 μM, respectively. Docking analysis showed that they bound steroid-binding site of rat HSD3B4. In conclusion, PFC showed significant SAR differences. The potency of inhibiting HSD3B activity increased from C9 to C11, and then declined. Human HSD3B1 was more sensitive to the inhibition of rat HSD3B4.