Inhibitory effects of cholesterol sulfate on progesterone production in human granulosa-like tumor cell line, KGN

Human and rat gonadal 3β-hydroxysteroid dehydrogenases are suppressed by dithiocarbamate fungicides via interacting with cysteine residues

Dithiocarbamates have been widely used in various industrial applications, such as insecticides (ferbam) or drug (disulfiram). This study explored the inhibitory effects of dithiocarbamates on human and rat gonadal 3β-hydroxysteroid dehydrogenases (3β-HSD) and investigated the structure-activity relationship and mechanistic insights. The inhibitory activity of six dithiocarbamates and thiourea on the conversion of pregnenolone to progesterone was evaluated using human KGN cell and rat testicular microsomes, with subsequent progesterone measurement using HPLC-MS/MS. The study found that among the tested compounds disulfiram, ferbam, and thiram exhibited significant inhibitory activity against human 3β-HSD2 and rat 3β-HSD1, with ferbam demonstrating the highest potency. The mode of action for these compounds was characterized, showing mixed inhibition for human 3β-HSD2 and mixed/noncompetitive inhibition for rat 3β-HSD1. Additionally, it was observed that dithiothreitol dose-dependently reversed the inhibitory effects of dithiocarbamates on both human and rat gonadal 3β-HSD enzymes. The study also delved into the penetration of these dithiocarbamates through the human KGN cell membrane and their impact on progesterone production, highlighting their potency in inhibiting human 3β-HSD2. Furthermore, bivariate correlation analysis revealed a positive correlation of LogP (lipophilicity) with IC50 values for both enzymes. Docking analysis indicated that dithiocarbamates bind to NAD+ and steroid-binding sites, with some interactions with cysteine residues. In conclusion, this study provides valuable insights into the structure-activity relationship and mechanistic aspects of dithiocarbamates as inhibitors of human and rat gonadal 3β-HSDs, suggesting that these compounds likely exert their inhibitory effects through binding to cysteine residues.

Inhibitory effects of parabens on human and rat 17β-hydroxysteroid dehydrogenase 1: Mechanisms of action and impact on hormone synthesis

Parabens are commonly used preservatives in cosmetics, food, and pharmaceutical products. The objective of this study was to examine the effect of nine parabens on human and rat 17β-hydroxysteroid dehydrogenase 1 (17β-HSD1) in human placental and rat ovarian cytosols, as well as on estradiol synthesis in BeWo cells. The results showed that the IC50 values for these compounds varied from methylparaben with the weakest inhibition (106.42 μM) to hexylparaben with the strongest inhibition (2.05 μM) on human 17β-HSD1. Mode action analysis revealed that these compounds acted as mixed inhibitors. For rats, the IC50 values ranged from the weakest inhibition for methylparaben (no inhibition at 100 μM) to the most potent inhibition for hexylparaben (0.87 μM), and they functioned as mixed inhibitors. Docking analysis indicated that parabens bind to the region bridging the NADPH and steroid binding sites of human 17β-HSD1 and the NADPH binding site of rat 17β-HSD1. Bivariate correlation analysis demonstrated negative correlations between LogP, molecular weight, heavy atoms, and apolar desolvation energy, and the IC50 values of these compounds. In conclusion, this study identified the inhibitory effects of parabens and their binding mechanisms on human and rat 17β-HSD1, as well as their impact on hormone synthesis.

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.

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.

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.

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.

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.

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.

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.

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.

Amelioration of cholesterol sulfate for lead-induced CTX cell apoptosis based on BDNF signaling pathway mediated cholesterol metabolism

Lead (Pb), as a deleterious heavy metal, ubiquitously exists in environment and industry, which engenders multi-organ disfunction, especially the brain of infants who are vulnerable to attack from lead-induced neurotoxicity. Although cholesterol sulfate (CS) is crucial constituent of cell membranes and precursor of neurosteroids, which maintains the function and survival of neurons, the role of CS in lead-induced neurological damage still remains incomplete. In this work, Rat Brain Astrocytes cell line (CTX cells) was applied into exploration that protective effects of CS on CTX cell apoptosis induced by lead via the regulation of BDNF/TrkB signaling pathway mediated cholesterol metabolism. We found that CTX cells exposed to lead manifested apparent cytotoxicity, where the viability of CTX cells was significantly suppressed, accompanied with the elevation of apoptosis, in response to a trend towards increases in reactive oxygen species (ROS) production and pro-apoptotic protein Cleaved-caspase3, synchronized with the decline in anti-apoptotic protein Bcl-2. Moreover, accumulation of lead in CTX cells showed a dose-dependent increase, and meanwhile, decrements in cholesterol content occurred along with increase in lead exposure, in which expressions of cholesterol metabolism related proteins and transcriptions of its genes (SREBP2, LDLR, and HMGCR) were diminished. Furthermore, BDNF signaling pathway was obviously blocked after lead exposure, down-regulating expressions of proteins BDNF and TrkB. However, pretreatment with CS detoxified the negative impacts of lead-invoked CTX cell damage, acting as an effective remedy for apoptosis, imbalance of cholesterol metabolism and inhibition of BDNF signaling pathway. In addition, the relationship between BDNF signaling pathway and cholesterol metabolism was further verified, in which cholesterol metabolism related proteins and genes were promoted significantly after the activation of BDNF/TrkB signaling pathway using 7,8-Dihydroxyflavone (7,8-DHF), thereby detoxifying lead-induced CTX cell injury. However, the pretreatment of TrkB inhibitor ANA-12 offset the promotion of 7,8-DHF and ultimately inhibit cholesterol metabolism. Overall, our study demonstrated that CS could initiate the BDNF/TrkB signaling pathway, regulating the cholesterol metabolism against CTX cell apoptosis invoked by lead.

Underestimated reactions and regulation patterns of adrenal cytochromes P450

Although cytochrome P450 (CYP) systems including the adrenal ones are being investigated since many years, there are still reactions and regulation patterns that have been underestimated ever since. This review discusses neglected ones to bring them into the focus of investigators working in the field. Novel substrates and reactions described for adrenal CYPs recently point to the fact that different from what has been believed for many years, adrenal CYPs are less selective than previously thought. The conversion of steroid sulfates, intermediates of steroid biosynthesis as well as of exogenous compounds are being discussed here in more detail and consequences for further studies are drawn. Furthermore, it was shown that protein-protein interactions may have an important effect not only on the activity of adrenal CYPs, but also on the product pattern of the reactions. It was found that, as expected, the stoichiometry of CYP:redox partner plays an important role for tuning the activity. In addition, competition between different CYPs for the redox partner and for electrons and possible alterations by mutants in the efficiency of electron transfer play an important role for the activity and product pattern. Moreover, the influence of phosphorylation and small charged molecules like natural polyamines on the activity of adrenal systems has been demonstrated in-vitro indicating a possible regulation of adrenal CYP reactions by affecting redox partner recognition and binding affinity. Finally, an effect of the genetic background on the consequences of mutations in adrenal CYPs found in patients was suggested from corresponding in-vitro studies indicating that a different genetic background might be able to significantly affect the activity of a CYP mutant.

Characterization and identification of human immortalized granulosa cells derived from ovarian follicular fluid

Follicular fluid serves a crucial role in follicular development and oocyte maturation. Increasing evidence indicates that follicular fluid is rich in proteins and functional cells. In addition to oocyte cells, follicular fluid contains granulosa, thecal and ovarian surface epithelial cells. Granulosa cells (GCs) represent the predominant somatic cell type of the ovarian follicle and are involved in steroidogenesis and folliculogenesis. However, the long-term culture of GCs in vitro remains challenging. The present study aimed to extend the culture of GCs in vitro. Human GCs were collected from the follicular fluid of patients included in an in vitro fertilization program and cultured in the presence of conditioned medium obtained from mouse embryonic fibroblasts. GCs were cultured for over a year and 130 passages, and the population doubling time was ~22 h. Cells presented epithelial-like morphology and a cobblestone-like appearance when they reached confluence. Flow cytometric analysis demonstrated that cells expressed CD29, CD166 and CD49f but not CD31, CD34, CD45, CD90, CD105 or CD13. Immunofluorescence staining revealed that cells expressed follicle stimulating hormone receptor, luteinizing hormone receptor and cytochrome P450 aromatase, which was confirmed by reverse transcription-quantitative polymerase chain reaction. In the presence of androstenedione, cells secreted estradiol. In addition, estradiol level was further stimulated by dibutyryl cAMP treatment. In addition, intracellular cAMP and progesterone expression levels were upregulated by follicle stimulating hormone and/or human chorionic gonadotropin. Furthermore, cells survived in severe combined immunodeficiency mice following intra-ovarian injection. Histological analysis revealed that certain cells formed follicle-like structures. The results from the present study suggested that immortalized GCs may be a useful tool for further research on GC and improve the clinical application of drugs such as follicle-stimulating hormone or human chorionic gonadotropin.

Cumulus cell pappalysin-1, luteinizing hormone/choriogonadotropin receptor, amphiregulin and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 mRNA levels associate with oocyte developmental competence and embryo outcomes

PURPOSE

To determine whether a selected set of mRNA biomarkers expressed in individual cumulus granulosa cell (CC) masses show association with oocyte developmental competence, embryo ploidy status, and embryo outcomes.

METHODS

This prospective observational cohort pilot study assessed levels of mRNA biomarkers in 163 individual CC samples from 15 women stimulated in antagonist cycles. Nineteen mRNA biomarker levels were measured by real-time PCR and related to the development of their corresponding individually cultured oocytes and subsequent embryos, embryo ploidy status, and live birth outcomes.

RESULTS

PAPPA mRNA levels were significantly higher in CC from oocytes that led to euploid embryos resulting in live births and aneuploid embryos compared to immature oocytes by ANOVA. LHCGR mRNA levels were significantly higher in CC of oocytes resulting in embryos associated with live birth compared to immature oocytes and oocytes resulting in arrested embryos by ANOVA. Using a general linearized mixed model to assess ploidy status, CC HSD3B mRNA levels in oocytes producing euploid embryos were significantly lower than other oocyte outcomes, collectively. When transferred euploid embryos outcomes were analyzed by ANOVA, AREG mRNA levels were significantly lower and PAPPA mRNA levels significantly higher in CC from oocytes that produced live births compared to transferred embryos that did not form a pregnancy.

CONCLUSIONS

Collectively, PAPPA, LHCGR, and AREG mRNA levels in CC may be able to identify oocytes with the best odds of resulting in a live birth, and HSD3B1 mRNA levels may be able to identify oocytes capable of producing euploid embryos.

Effect of sulfonated steroids on steroidogenic cytochrome P450-dependent steroid hydroxylases

In the last decades, sulfonated steroids evolved from inactive metabolites intended for excretion to highly relevant compounds involved in many physiological processes. Investigations of the impact of sulfonated steroids on the steroid hormone biosynthesis revealed that, on the one hand, these can serve as substrate for steroidogenic cytochromes P450 and, on the other hand, these are able to influence the catalytic properties of these enzymes. In this review the relevance of sulfonated steroids for the steroid hormone biosynthesis will be discussed.

Dehydroepiandrosterone (DHEA) and Its Sulfate (DHEA-S) in Mammalian Reproduction: Known Roles and Novel Paradigms

Steroid hormones form an integral part of normal development in mammalian organisms. Cholesterol is the parent compound from which all steroid hormones are synthesized. The product pregnenolone formed from cholesterol serves as precursor for mineralocorticoids, glucocorticoids, as well as dehydroepiandrosterone (DHEA) and its derived sexual hormones. DHEA assumes the prohormone status of a predominant endogenous precursor and a metabolic intermediate in ovarian follicular steroidogenesis. DHEA supplementation has been used to enhance ovarian reserve. Steroids like estradiol and testosterone have long been contemplated to play important roles in regulating meiotic maturation of oocytes in conjunction with gonadotropins. It is known that oocyte priming with estrogen is necessary to develop calcium (Ca²⁺) oscillations during maturation. Accruing evidence from diverse studies suggests that DHEA and its sulfate (dehydroepiandrosterone sulfate, DHEA-S) play significantly vital role not only as intermediates in androgen and estrogen formation, but may also be the probable 'oocyte factor' and behave as endogenous agonists triggering calcium oscillations for oocyte activation. DHEA/DHEA-S have been reported to regulate calcium channels for the passage of Ca²⁺ through the oocyte cytoplasm and for maintaining required threshold of Ca²⁺ oscillations. This role of DHEA/DHEA-S assumes critical significance in assisted reproductive technology and in-vitro fertilization treatment cycles where physical, chemical, and mechanical methods are employed for artificial oocyte activation to enhance fertilization rates. However, since these methods are invasive and may also cause adverse epigenetic modifications; oral or culture-media supplementation with DHEA/DHEA-S provides a noninvasive innate mechanism of in-vitro oocyte activation based on physiological metabolic pathway.

Syndecan 1 represses cell growth and FSH responsiveness in human granulosa cells

Albeit devoid of intrinsic catalytic activity, the transmembrane heparan sulphate proteoglycan syndecan 1 plays critical roles in cellular processes such as extracellular matrix crosstalk, cytoskeletal organization, cell spreading, proliferation and differentiation. During the ovarian cycle, the expression of syndecan 1 in granulosa cells shows cyclic variation suggesting that it might fulfil specific roles in follicle development. To investigate its physiological roles on granulosa cells, syndecan 1 was overexpressed in human granulosa cell line KGN which retains features of granulosa cells from small antral follicle such as estradiol (E2) synthesis and low expression of functional FSH receptor (FSHR). We demonstrated that overexpression of syndecan 1 in immature granulosa cells (KGN-SDC1) induces a profound alteration in their intrinsic characteristics including enhanced spreading and attachment, both associated with a reduced growth rate. Flow cytometry analysis revealed that syndecan 1 overexpression increases the percentage of KGN cells in quiescent phase. This partial cell cycle exit is concordant with downregulated levels of CCND1 and CDK4 and upregulated expression of CDK inhibitor CDKN1A. In parallel both unstimulated and FSH-induced E2 synthesis are reduced in KGN-SDC1 through both repression of CYP19A1 and FSHR mRNA associated with decreased levels of potential regulators NR5A1 and ESR2. Additionally, we provide evidence that transient cAMP accumulation reduction in cells overexpressing syndecan 1 is accompanied by an increase in cAMP-hydrolysing PDE activity. Our results demonstrated that syndecan 1 might regulate differentiation of granulosa cells and follicular development by means of various mechanisms involving morphological changes, control of signalling pathways and alterations in gene expressions.

Free French abstract: A French translation of this abstract is freely available at http://www.reproduction-online.org/content/153/6/797/suppl/DC2

Dehydroepiandrosterone sulfate (DHEAS) stimulates the first step in the biosynthesis of steroid hormones

Dehydroepiandrosterone sulfate (DHEAS) is the most abundant circulating steroid in human, with the highest concentrations between age 20 and 30, but displaying a significant decrease with age. Many beneficial functions are ascribed to DHEAS. Nevertheless, long-term studies are very scarce concerning the intake of DHEAS over several years, and molecular investigations on DHEAS action are missing so far. In this study, the role of DHEAS on the first and rate-limiting step of steroid hormone biosynthesis was analyzed in a reconstituted in vitro system, consisting of purified CYP11A1, adrenodoxin and adrenodoxin reductase. DHEAS enhances the conversion of cholesterol by 26%. Detailed analyses of the mechanism of DHEAS action revealed increased binding affinity of cholesterol to CYP11A1 and enforced interaction with the electron transfer partner, adrenodoxin. Difference spectroscopy showed K_d-values of 40±2.7 µM and 24.8±0.5 µM for CYP11A1 and cholesterol without and with addition of DHEAS, respectively. To determine the K_d-value for CYP11A1 and adrenodoxin, surface plasmon resonance measurements were performed, demonstrating a K_d-value of 3.0±0.35 nM (with cholesterol) and of 2.4±0.05 nM when cholesterol and DHEAS were added. Kinetic experiments showed a lower K_m and a higher k_cat value for CYP11A1 in the presence of DHEAS leading to an increase of the catalytic efficiency by 75%. These findings indicate that DHEAS affects steroid hormone biosynthesis on a molecular level resulting in an increased formation of pregnenolone.

Expression of retinoic acid-related orphan receptor alpha and its responsive genes in human endometrium regulated by cholesterol sulfate

Cholesterol sulfate (CS) is a major sterol sulfate in human plasma that is detected in the uterine endometrium. CS plays a role in steroidogenesis, cellular membrane stabilization, and regulation of the skin barrier. We previously reported that CS increased in rabbit endometrium during the implantation period. Recently, CS has been reported to be a ligand of retinoic acid receptor-related orphan receptor alpha (RORA). NR1D1 is one of the genes regulated by RORA. In the present study, we investigated the regulation of RORA and NR1D1 by CS in human endometrium. We determined the association-dissociation curves for the interaction of CS with RORA and the kinetic rates by surface plasmon resonance. Immunohistochemical staining and in situ hybridization revealed that RORA and NR1D1 were expressed in human endometrial stromal and epithelial cells. CS treatment significantly induced the mRNA expression of RORA and NR1D1 mRNA in ESCs. The results of a luciferase assay showed that RORA significantly activated the human NR1D1 promoter regardless of CS. Our results suggest that CS regulates the expression of RORA responsive genes in human endometrial cells but not as a ligand for RORA.

Alterations of folliculogenesis in women with polycystic ovary syndrome

The objective of the present study was to examine some factors involved in follicular development of women with polycystic ovary syndrome (PCOS). Women with PCOS showed increased levels of serum luteinizing hormone (LH) but decreased follicular production of progesterone and estradiol by pre-ovulatory follicles. The mRNA expression corresponding to steroidogenic acute regulatory protein (StAR), and 20alpha-hydroxysteroid dehydrogenase (20α-HSD) was increased, while that corresponding to cytochrome P450 aromatase (P450arom) was decreased in PCOS follicles as compared to controls. No changes in the mRNA expression for 3beta-hydroxysteroid dehydrogenase 2 (3β-HSD2), cytochrome P450 side-chain cleavage (P450scc), cytochrome P450 17 alpha hydroxylase/lyase (P450c17), cyclooxygenase 2 (COX2), and transcription factors (GATA-4 and GATA-6) were found. We conclude that despite the hyper-luteinized environment of PCOS follicles, these follicles produce lower levels of progesterone and estradiol, and that this is characterized by increased degradation of progesterone and decreased estradiol synthesis. Our data demonstrate that the synthesis of prostaglandin F2α (PGF2α) may be affected in PCOS-follicles and that the transcription factors GATA-4 and GATA-6 are present in PCOS-follicles but they are not involved in the abnormal transcription observed in the steroidogenic enzymes.

Transcriptional regulation of steroidogenic genes: STARD1, CYP11A1 and HSD3B

Expression of the genes that mediate the first steps in steroidogenesis, the steroidogenic acute regulatory protein (STARD1), the cholesterol side-chain cleavage enzyme, cytochrome P450scc (CYP11A1) and 3beta-hydroxysteroid dehydrogenase/Delta5-Delta4 isomerase (HSD3B), is tightly controlled by a battery of transcription factors in the adrenal cortex, the gonads and the placenta. These genes generally respond to the same hormones that stimulate steroid production through common pathways such as cAMP signaling and common actions on their promoters by proteins such as NR5A and GATA family members. However, there are distinct temporal, tissue and species-specific differences in expression between the genes that are defined by combinatorial regulation and unique promoter elements. This review will provide an overview of the hormonal and transcriptional regulation of the STARD1, CYP11A1 and specific steroidogenic HSD3B genes in the adrenal, testis, ovary and placenta and discuss the current knowledge regarding the key transcriptional factors involved.