Role of hydroxysteroid (17beta) dehydrogenase type 1 in reproductive tissues and hormone-dependent diseases

Exposure-effect of PFOS and PFOA on lung function: An integrated approach with epidemiological, cellular, and animal studies

Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are increasingly recognized for their adverse impact on human health, particularly on lung function. However, current research results are inconsistent and molecular mechanisms remain unclear, with no studies combining epidemiological, in vivo and in vitro investigations. Our population-based study revealed that PFOS and PFOA exposure is negatively associated with lung function. In vitro, PFOS and PFOA exposure significantly downregulated SP-B mRNA and protein levels, and SP-B expression was restored by overexpression of HSD17B1. PFOS induced hypermethylation and downregulated expression of HSD17B1 in tandem with SP-B. Notably, expression of SP-B was restored after treatment with demethyltransferase inhibitor. In vivo studies corroborated these findings, where PFOS exposure resulted in impaired lung function, histopathological changes, and decreased expression of SP-B and HSD17B1 in lung tissues. Our research demonstrates that PFOS downregulates SP-B expression by inducing hypermethylation and downregulating expression of HSD17B1, leading to impaired lung function.

Impact of Missense Variants on the Structure and Function of Polycystic Ovary Syndrome-Associated HSD17B1 Gene

HSD17B1 regulates estrogen availability in the ovary, and its dysregulation is linked to cyst formation in polycystic ovary syndrome. This study aimed to understand the role of missense variants in HSD17B1 dysfunction. Bioinformatic tools (sift, polyphen2, panther, snps & go, phd-snp, pmut, snap and revel score) were used to identify the deleterious missense variants of HSD17B1 gene. InterPro and Pfam tools were utilized to predict the functional domain of these deleterious variants, and its impact on structure and stability of HSD17B1 was analyzed by Hope, MutPred2, I-Mutant 2.0, and Mupro. Further, the AutoDock was used to determine the binding affinity of NADP to HSD17B1 protein. Finally, the HSD17B1 expression in clinical samples was analyzed using qRT-PCR. Of the 355 missense variants identified, five (rs202173252, rs149630844, rs146159533, rs200202791, and rs138503851) variants were deleterious, pocketed at the NADP binding domain and located at the conserved region of HSD17B1. Further, series of in silico prediction and molecular docking shows only the variant T191I (rs138503851) has an adverse effect on HSD17B1 function because of increased unfavorable bonds and non-interaction of adenine and nicotinamide of NADP to the Glycine94 and Leucine93 of HSD17B1. Additionally, a two-fold reduced expression of HSD17B1 in peripheral blood of PCOS subjects was observed, compared to healthy individuals. Overall, these results indicate that rs138503851 genetic variant of HSD17B1 may affect estrogen synthesis in PCOS. However, further clinical studies are warranted to validate the presence of rs138503851 genetic variant to identify the potential females who are predisposal to the development of PCOS.

Sexually dimorphic gene expression responses of bovine embryos to the maternal microenvironment on day 13 of gestation

BACKGROUND

Various studies have highlighted significant differences in developmental kinetics and sensitivity to developmental conditions between male and female bovine embryos. These differences are thought to be caused in part by the sexually dimorphic expression of genes located on the sex or autosomal chromosomes. However, little is known about the dimorphic gene expression patterns of bovine embryos at the initiation of elongation, which is one of the critical stages of development. Furthermore, to the best of our knowledge, there is little or no data available on the sexually dimorphic gene expression patterns in bovine embryos in relation to maternal environmental conditions during the initiation of elongation. Therefore, the main objective of this study was to investigate the sexually dimorphic gene expression responses of embryos to the maternal environment at the initiation of elongation in embryos developed in lactating dairy cows and nonlactating nulliparous heifers.

RESULTS

Gene expression analysis showed that 159 genes including those involved in steroid biosynthesis and gastrulation were differentially expressed exclusively between male and female embryos developed in cows. Among these, 61 genes including CYP39 A1, CYP2R1 and CYP27B1 were upregulated and 98 genes including HSD17B1, HSD17B10 and aromatase (CYP19 A1) were downregulated in male embryos. Chromosomal analysis showed that 31.2% of the differentially expressed genes (DEGs) including glucose-6-phosphate dehydrogenase (G6PD) were located on the X chromosome, and 96% of those were upregulated in female embryos. Similarly, 254 genes including those involved in female sex differentiation, placenta development, transmembrane transport, and cell adhesion were differentially expressed exclusively between the male and female embryos developed in heifers. Of these, 108 genes including HSD17B11, HSD17B12, and HSD3B1 were upregulated, and 146 genes including SLC16 A9, SLC10 A1, SLC10 A3, SLC16 A5, SLC22 A23, SLC25 A43, SLC35 A2, SLC35 C1, and SLC4 were downregulated in male compared to female embryos. In addition, 17.3% of the DEGs were located on the X chromosome and 75% of the DEGs located on the X chromosome were upregulated in female embryos. On the other hand, 38 genes including SLC30 A10, SLC10 A4, ATP6 AP1, and KDM5 C showed sexually dimorphic expression patterns in day 13 bovine embryos irrespective of the maternal environment. These genes accounted for only 19% and 13% of the genes that showed sexually dimorphic expression in embryos developed in cows and heifers, respectively and the expression difference of these genes in male and female embryos was then likely influenced by the sex of the embryo.

CONCLUSION

This study revealed that embryos developed in lactating cows showed sexually dimorphic expression of genes involved in various functions including steroid biosynthesis and gastrulation. In contrast, embryos developed in heifers displayed sexually dimorphic expression of genes related to placental development, female sex differentiation, and transmembrane transport. This suggests that the reproductive tract environments of cows and heifers differently affect the sex specific expression of genes in bovine embryos. A higher proportion of genes that showed sexually dimorphic expression in cow embryos were located on the X chromosome, and the majority of these genes were upregulated in female embryos. Overall, this study provides insight into genes that exhibit sexually dimorphic expression patterns in day 13 bovine embryos due to the maternal reproductive tract microenvironment or solely due to the sex of the embryo.

Revealing the impact of Pseudomonas aeruginosa quorum sensing molecule 2'-aminoacetophenone on human bronchial-airway epithelium and pulmonary endothelium using a human airway-on-a-chip

Pseudomonas aeruginosa (PA) causes severe respiratory infections utilizing multiple virulence functions. Our previous findings on PA quorum sensing (QS)-regulated small molecule, 2'-aminoacetophenone (2-AA), secreted by the bacteria in infected tissues, revealed its effect on immune and metabolic functions favouring a long-term presence of PA in the host. However, studies on 2-AA's specific effects on bronchial-airway epithelium and pulmonary endothelium remain elusive. To evaluate 2AA's spatiotemporal changes in the human airway, considering endothelial cells as the first point of contact when the route of lung infection is hematogenic, we utilized the microfluidic airway-on-chip lined by polarized human bronchial-airway epithelium and pulmonary endothelium. Using this platform, we performed RNA-sequencing to analyse responses of 2-AA-treated primary human pulmonary microvascular endothelium (HPMEC) and adjacent primary normal human bronchial epithelial (NHBE) cells from healthy female donors and potential cross-talk between these cells. Analyses unveiled specific signaling and biosynthesis pathways to be differentially regulated by 2-AA in epithelial cells, including HIF-1 and pyrimidine signaling, glycosaminoglycan, and glycosphingolipid biosynthesis, while in endothelial cells were fatty acid metabolism, phosphatidylinositol and estrogen receptor signaling, and proinflammatory signaling pathways. Significant overlap in both cell types in response to 2-AA was found in genes implicated in immune response and cellular functions. In contrast, we found that genes related to barrier permeability, cholesterol metabolism, and oxidative phosphorylation were differentially regulated upon exposure to 2-AA in the cell types studied. Murine in-vivo and additional in vitro cell culture studies confirmed cholesterol accumulation in epithelial cells. Results also revealed specific biomarkers associated with cystic fibrosis and idiopathic pulmonary fibrosis to be modulated by 2-AA in both cell types, with the cystic fibrosis transmembrane regulator expression to be affected only in endothelial cells. The 2-AA-mediated effects on healthy epithelial and endothelial primary cells within a microphysiological dynamic environment mimicking the human lung airway enhance our understanding of this QS signaling molecule. This study provides novel insights into their functions and potential interactions, paving the way for innovative, cell-specific therapeutic strategies to combat PA lung infections.

Structure-activity relationship and in silico docking analysis of dicarboximide fungicides on 17β-hydroxysteroid dehydrogenase 1 of human, rat, and pig

Dicarboximide fungicides, including captafol, captan, cyclohexylthiophthalimide, folpet, and procymidone, represent a distinct category of fungicides. 17β-Hydroxysteroid dehydrogenase 1 (17β-HSD1) catalyzes the conversion of estrone to estradiol in mammals. Yet, the impact of these fungicides on 17β-HSD1 activity remains unknown. In this study, we investigated their inhibition using human placental cytosols, rat and pig ovarian cytosols. Our observations revealed that dicarboximide fungicides significantly inhibited human 17β-HSD1 activity. Among them, captan showed the strongest potency, with its IC50 of 1.28 μM, whereas procymidone had an IC50 of 100.71 μM. However, both rat and pig 17β-HSD1 enzymes were less sensitive to the inhibition of these fungicides compared to the human enzyme, with captan displaying an IC50 of 5.65 μM for the rat enzyme and 7.36 μM for the pig enzyme. Correlation analysis indicated a positive correlation between IC50 values and LogP. Docking analysis revealed that these fungicides bound to cofactor or between the steroid and cofactor binding sites. The dithiothreitol treatment demonstrated that the formation of irreversible bonds between dicarboximide fungicides and the cysteine residues played a key role in the inhibition of 17β-HSD1 activity. In conclusion, dicarboximide fungicides inhibit 17β-HSD1 depending on lipophilicity, species, and cysteine residue interactions.

Serum hydroxysteroid (17beta) dehydrogenase 1 concentration in pregnant women correlates with pregnancy-associated plasma protein A but does not serve as an independent marker for preeclampsia†

Hydroxysteroid (17beta) dehydrogenase 1 (HSD17B1) is a steroid synthetic enzyme expressed in ovarian granulosa cells and placental syncytiotrophoblasts. Here, HSD17B1 serum concentration was measured with a validated immunoassay during pregnancy at three time points (12-14, 18-20 and 26-28 weeks of gestation). The concentration increased 2.5-fold (P < 0.0001) and 1.7-fold (P = 0.0019) during the follow-up period for control women and women who later developed preeclampsia (PE), respectively, and a significant difference was observed at weeks 26-28 (P = 0.0266). HSD17B1 concentration at all the three time points positively correlated with serum PAPPA measured at the first time point (first time point r = 0.38, P = 1.1 × 10-10; second time point r = 0.27, P = 5.9 × 10-6 and third timepoint r = 0.26, P = 2.3 × 10-5). No correlation was observed between HSD17B1 and placental growth factor (PLGF). Serum HSD17B1 negatively correlated with the mother's weight and body mass index (BMI), mirroring the pattern observed for PAPPA. The univariable logistic regression identified a weak association between HSD17B1 at 26-28 weeks and later development of PE (P = 0.04). The best multivariable model obtained using penalized logistic regression with stable iterative variable selection at 26-28 weeks included HSD17B1, together with PLGF, PAPPA and mother's BMI. While the area under the receiver operating characteristic curve of the model was higher than that of the adjusted PLGF, the difference was not statistically significant. In summary, the serum concentration of HSD17B1 correlated with PAPPA, another protein expressed in syncytiotrophoblasts, and with mother's weight and BMI but could not be considered as an independent marker for PE.

Targeting the formation of estrogens for treatment of hormone dependent diseases-current status

Local formation and action of estrogens have crucial roles in hormone dependent cancers and benign diseases like endometriosis. Drugs that are currently used for the treatment of these diseases act at the receptor and at the pre-receptor levels, targeting the local formation of estrogens. Since 1980s the local formation of estrogens has been targeted by inhibitors of aromatase that catalyses their formation from androgens. Steroidal and non-steroidal inhibitors have successfully been used to treat postmenopausal breast cancer and have also been evaluated in clinical studies in patients with endometrial, ovarian cancers and endometriosis. Over the past decade also inhibitors of sulfatase that catalyses the hydrolysis of inactive estrogen-sulfates entered clinical trials for treatment of breast, endometrial cancers and endometriosis, with clinical effects observed primarily in breast cancer. More recently, inhibitors of 17beta-hydroxysteroid dehydrogenase 1, an enzyme responsible for formation of the most potent estrogen, estradiol, have shown promising results in preclinical studies and have already entered clinical evaluation for endometriosis. This review aims to provide an overview of the current status of the use of hormonal drugs for the major hormone-dependent diseases. Further, it aims to explain the mechanisms behind the -sometimes- observed weak effects and low therapeutic efficacy of these drugs and the possibilities and the advantages of combined treatments targeting several enzymes in the local estrogen formation, or drugs acting with different therapeutic mechanisms.

Comparison of Placental HSD17B1 Expression and Its Regulation in Various Mammalian Species

During mammalian gestation, large amounts of progesterone are produced by the placenta and circulate for the maintenance of pregnancy. In contrast, primary plasma estrogens are different between species. To account for this difference, we compared the expression of ovarian and placental steroidogenic genes in various mammalian species (mouse, guinea pig, porcine, ovine, bovine, and human). Consistent with the ability to synthesize progesterone, CYP11A1/Cyp11a1, and bi-functional HSD3B/Hsd3b genes were expressed in all species. CYP17A1/Cyp17a1 was expressed in the placenta of all species, excluding humans. CYP19A/Cyp19a1 was expressed in all placental estrogen-producing species, whereas estradiol-producing HSD17B1 was only strongly expressed in the human placenta. The promoter region of HSD17B1 in various species possesses a well-conserved SP1 site that was activated in human placental cell line JEG-3 cells. However, DNA methylation analyses in the ovine placenta showed that the SP1-site in the promoter region of HSD17B1 was completely methylated. These results indicate that epigenetic regulation of HSD17B1 expression is important for species-specific placental sex steroid production. Because human HSD17B1 showed strong activity for the conversion of androstenedione into testosterone, similar to HSD17B1/Hsd17b1 in other species, we also discuss the biological significance of human placental HSD17B1 based on the symptoms of aromatase-deficient patients.

Master-Key Regulators of Sex Determination in Fish and Other Vertebrates-A Review

In vertebrates, mainly single genes with an allele ratio of 1:1 trigger sex-determination (SD), leading to initial equal sex-ratios. Such genes are designated master-key regulators (MKRs) and are frequently associated with DNA structural variations, such as copy-number variation and null-alleles. Most MKR knowledge comes from fish, especially cichlids, which serve as a genetic model for SD. We list 14 MKRs, of which dmrt1 has been identified in taxonomically distant species such as birds and fish. The identification of MKRs with known involvement in SD, such as amh and fshr, indicates that a common network drives SD. We illustrate a network that affects estrogen/androgen equilibrium, suggesting that structural variation may exert over-expression of the gene and thus form an MKR. However, the reason why certain factors constitute MKRs, whereas others do not is unclear. The limited number of conserved MKRs suggests that their heterologous sequences could be used as targets in future searches for MKRs of additional species. Sex-specific mortality, sex reversal, the role of temperature in SD, and multigenic SD are examined, claiming that these phenomena are often consequences of artificial hybridization. We discuss the essentiality of taxonomic authentication of species to validate purebred origin before MKR searches.

Overexpression of Human Estrogen Biosynthetic Enzyme Hydroxysteroid (17beta) Dehydrogenase Type 1 Induces Adenomyosis-like Phenotype in Transgenic Mice

Hydroxysteroid (17beta) dehydrogenase type 1 (HSD17B1) is an enzyme that converts estrone to estradiol, while adenomyosis is an estrogen-dependent disease with poorly understood pathophysiology. In the present study, we show that mice universally over-expressing human estrogen biosynthetic enzyme HSD17B1 (HSD17B1TG mice) present with adenomyosis phenotype, characterized by histological and molecular evaluation. The first adenomyotic changes with endometrial glands partially or fully infiltrated into the myometrium appeared at the age of 5.5 months in HSD17B1TG females and became more prominent with increasing age. Preceding the phenotype, increased myometrial smooth muscle actin positivity and increased amount of glandular myofibroblast cells were observed in HSD17B1TG uteri. This was accompanied by transcriptomic upregulation of inflammatory and estrogen signaling pathways. Further, the genes upregulated in the HSD17B1TG uterus were enriched with genes previously observed to be induced in the human adenomyotic uterus, including several genes of the NFKB pathway. A 6-week-long HSD17B1 inhibitor treatment reduced the occurrence of the adenomyotic changes by 5-fold, whereas no effect was observed in the vehicle-treated HSD17B1TG mice, suggesting that estrogen is the main upstream regulator of adenomyosis-induced uterine signaling pathways. HSD17B1 is considered as a promising drug target to inhibit estrogen-dependent growth of endometrial disorders. The present data indicate that HSD17B1 over-expression in TG mice results in adenomyotic changes reversed by HSD17B1 inhibitor treatment and HSD17B1 is, thus, a potential novel drug target for adenomyosis.

Comprehensive Sex Steroid Profiling in Multiple Tissues Reveals Novel Insights in Sex Steroid Distribution in Male Mice

A comprehensive atlas of sex steroid distribution in multiple tissues is currently lacking, and how circulating and tissue sex steroid levels correlate remains unknown. Here, we adapted and validated a gas chromatography tandem mass spectrometry method for simultaneous measurement of testosterone (T), dihydrotestosterone (DHT), androstenedione, progesterone (Prog), estradiol, and estrone in mouse tissues. We then mapped the sex steroid pattern in 10 different endocrine, reproductive, and major body compartment tissues and serum of gonadal intact and orchiectomized (ORX) male mice. In gonadal intact males, high levels of DHT were observed in reproductive tissues, but also in white adipose tissue (WAT). A major part of the total body reservoir of androgens (T and DHT) and Prog was found in WAT. Serum levels of androgens and Prog were strongly correlated with corresponding levels in the brain while only modestly correlated with corresponding levels in WAT. After orchiectomy, the levels of the active androgens T and DHT decreased markedly while Prog levels in male reproductive tissues increased slightly. In ORX mice, Prog was by far the most abundant sex steroid, and, again, WAT constituted the major reservoir of Prog in the body. In conclusion, we present a comprehensive atlas of tissue and serum concentrations of sex hormones in male mice, revealing novel insights in sex steroid distribution. Brain sex steroid levels are well reflected by serum levels and WAT constitutes a large reservoir of sex steroids in male mice. In addition, Prog is the most abundant sex hormone in ORX mice.

Analogues of Natural Chalcones as Efficient Inhibitors of AKR1C3

Naturally occurring substances are valuable resources for drug development. In this respect, chalcones are known to be antiproliferative agents against prostate cancer cell lines through various mechanisms or targets. Based on the literature and preliminary results, we aimed to study and optimise the efficiency of a series of chalcones to inhibit androgen-converting AKR1C3, known to promote prostate cancer. A total of 12 chalcones with different substitution patterns were synthesised. Structure-activity relationships associated with these modifications on AKR1C3 inhibition were analysed by performing enzymatic assays and docking simulations. In addition, the selectivity and cytotoxicity of the compounds were assessed. In enzymatic assays, C-6' hydroxylated derivatives were more active than C-6' methoxylated derivatives. In contrast, C-4 methylation increased activity over C-4 hydroxylation. Docking results supported these findings with the most active compounds fitting nicely in the binding site and exhibiting strong interactions with key amino acid residues. The most effective inhibitors were not cytotoxic for HEK293T cells and selective for 17β-hydroxysteroid dehydrogenases not primarily involved in steroid hormone metabolism. Nevertheless, they inhibited several enzymes of the steroid metabolism pathways. Favourable substitutions that enhanced AKR1C3 inhibition of chalcones were identified. This study paves the way to further develop compounds from this series or related flavonoids with improved inhibitory activity against AKR1C3.

Transcriptome comparative analysis of ovarian follicles reveals the key genes and signaling pathways implicated in hen egg production

Background

Ovarian follicle development plays an important role in determination of poultry egg production. The follicles at the various developmental stages possess their own distinct molecular genetic characteristics and have different biological roles in chicken ovary development and function. In the each stage, several genes of follicle-specific expression and biological pathways are involved in the vary-sized follicular development and physiological events. Identification of the pivotal genes and signaling pathways that control the follicular development is helpful for understanding their exact regulatory functions and molecular mechanisms underlying egg-laying traits of laying hens.

Results

The comparative mRNA transcriptomic analysis of ovarian follicles at three key developmental stages including slow growing white follicles (GWF), small yellow follicles (SYF) of recruitment into the hierarchy, and differentiated large yellow follicles (LYF), was accomplished in the layers with lower and higher egg production. Totally, 137, 447, and 229 of up-regulated differentially expressed genes (DEGs), and 99, 97, and 157 of down-regulated DEGs in the GWF, SYF and LYF follicles, including VIPR1, VIPR2, ADRB2, and HSD17B1 were identified, respectively. Moreover, NDUFAB1 and GABRA1 genes, two most promising candidates potentially associated with egg-laying performance were screened out from the 13 co-expressed DEGs in the GWF, SYF and LYF samples. We further investigated the biological effects of NDUFAB1 and GABRA1 on ovarian follicular development and found that NDUFAB1 promotes follicle development by stimulating granulosa cell (GC) proliferation and decreasing cell apoptosis, increases the expression of CCND1 and BCL-2 but attenuates the expression of caspase-3, and facilitates steroidogenesis by enhancing the expression of STAR and CYP11A1. In contrast, GABRA1 inhibits GC proliferation and stimulates cell apoptosis, decreases the expression of CCND1, BCL-2, STAR, and CYP11A1 but elevates the expression of caspase-3. Furthermore, the three crucial signaling pathways such as PPAR signaling pathway, cAMP signaling pathway and neuroactive ligand-receptor interaction were significantly enriched, which may play essential roles in ovarian follicle growth, differentiation, follicle selection, and maturation.

Conclusions

The current study provided new molecular data for insight into the regulatory mechanism underlying ovarian follicle development associated with egg production in chicken.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-08213-w.

Normal and Premature Adrenarche

Adrenarche is the maturational increase in adrenal androgen production that normally begins in early childhood. It results from changes in the secretory response to adrenocorticotropin (ACTH) that are best indexed by dehydroepiandrosterone sulfate (DHEAS) rise. These changes are related to the development of the zona reticularis (ZR) and its unique gene/enzyme expression pattern of low 3ß-hydroxysteroid dehydrogenase type 2 with high cytochrome b5A, sulfotransferase 2A1, and 17ß-hydroxysteroid dehydrogenase type 5. Recently 11-ketotestosterone was identified as an important bioactive adrenarchal androgen. Birth weight, body growth, obesity, and prolactin are related to ZR development. Adrenarchal androgens normally contribute to the onset of sexual pubic hair (pubarche) and sebaceous and apocrine gland development. Premature adrenarche causes ≥90% of premature pubarche (PP). Its cause is unknown. Affected children have a significantly increased growth rate with proportionate bone age advancement that typically does not compromise growth potential. Serum DHEAS and testosterone levels increase to levels normal for early female puberty. It is associated with mildly increased risks for obesity, insulin resistance, and possibly mood disorder and polycystic ovary syndrome. Between 5% and 10% of PP is due to virilizing disorders, which are usually characterized by more rapid advancement of pubarche and compromise of adult height potential than premature adrenarche. Most cases are due to nonclassic congenital adrenal hyperplasia. Algorithms are presented for the differential diagnosis of PP. This review highlights recent advances in molecular genetic and developmental biologic understanding of ZR development and insights into adrenarche emanating from mass spectrometric steroid assays.

Analyses of Molecular Characteristics and Enzymatic Activities of Ovine HSD17B3

17β-hydroxysteroid dehydrogenase type 3 (HSD17B3) converts androstenedione (A4) into testosterone (T), which regulates sex steroid production. Because various mutations of the HSD17B3 gene cause disorder of sex differentiation (DSD) in multiple mammalian species, it is very important to reveal the molecular characteristics of this gene in various species. Here, we revealed the open reading frame of the ovine HSD17B3 gene. Enzymatic activities of ovine HSD17B3 and HSD17B1 for converting A4 to T were detected using ovine androgen receptor-mediated transactivation in reporter assays. Although HSD17B3 also converted estrone to estradiol, this activity was much weaker than those of HSD17B1. Although ovine HSD17B3 has an amino acid sequence that is conserved compared with other mammalian species, it possesses two amino acid substitutions that are consistent with the reported variants of human HSD17B3. Substitutions of these amino acids in ovine HSD17B3 for those in human did not affect the enzymatic activities. However, enzymatic activities declined upon missense mutations of the HSD17B3 gene associated with 46,XY DSD, affecting amino acids that are conserved between these two species. The present study provides basic information and tools to investigate the molecular mechanisms behind DSD not only in ovine, but also in various mammalian species.

Associations among maternal perfluoroalkyl substance levels, fetal sex-hormone enzymatic gene polymorphisms, and fetal sex hormone levels in the Hokkaido study

Prenatal sex hormones affect fetal growth; for example, prenatal exposure to low levels of androgen accelerates female puberty onset. We assessed the association of perfluoroalkyl substances (PFASs) in maternal sera and infant genotypes of genes encoding enzymes involved in sex steroid hormone biosynthesis on cord sera sex hormone levels in a prospective birth cohort study of healthy pregnant Japanese women (n = 224) recruited in Sapporo between July 2002 and October 2005. We analyzed PFAS and five sex hormone levels using liquid chromatography-tandem mass spectrometry. Cytochrome P450 (CYP) 17A1 (CYP17A1 rs743572), 19A1 (CYP19A1 rs10046, rs700519, and rs727479), 3β-hydroxysteroid dehydrogenase type 1 (HSD3B1 rs6203), type 2 (HSD3B2 rs1819698, rs2854964, and rs4659175), 17β-hydroxysteroid dehydrogenase type 1 (HSD17B1 rs605059, rs676387, and rs2676531), and type 3 (HSD17B3 rs4743709) were analyzed using real-time PCR. Multiple linear regression models were used to establish the influence of log₁₀-transformed PFAS levels and infant genotypes on log₁₀-transformed sex steroid hormone levels. When the interaction between perfluorooctanesulfonate (PFOS) levels and female infant genotype CYP17A1 (rs743572) on the androstenedione (A-dione) levels was considered, the estimated changes (95 % confidence intervals) in A-dione levels against PFOS levels, female infant genotype CYP17A1 (rs743572)-AG/GG, and interaction between them showed a mean increase of 0.445 (0.102, 0.787), mean increase of 0.392 (0.084, 0.707), and mean reduction of 0.579 (0.161, 0.997) (P_int = 0.007), respectively. Moreover, a female-specific interaction with testosterone levels was observed. A-dione and T levels showed positive main effects and negative interaction with PFOS levels and the female infant CYP17A1 genotype.

Pharmacological inhibition of 17β-hydroxysteroid dehydrogenase impairs human endometrial cancer growth in an orthotopic xenograft mouse model

Endometrial cancer (EC) is the most common gynaecological tumor in developed countries and its incidence is increasing. Approximately 80% of newly diagnosed EC cases are estrogen-dependent. Type 1 17β-hydroxysteroid dehydrogenase (17β-HSD-1) is the enzyme that catalyzes the final step in estrogen biosynthesis by reducing the weak estrogen estrone (E1) to the potent estrogen 17β-estradiol (E2), and previous studies showed that this enzyme is implicated in the intratumoral E2 generation in EC. In the present study we employed a recently developed orthotopic and estrogen-dependent xenograft mouse model of EC to show that pharmacological inhibition of the 17β-HSD-1 enzyme inhibits disease development. Tumors were induced in one uterine horn of athymic nude mice by intrauterine injection of the well-differentiated human endometrial adenocarcinoma Ishikawa cell line, modified to express human 17β-HSD-1 in levels comparable to EC, and the luciferase and green fluorescent protein reporter genes. Controlled estrogen exposure in ovariectomized mice was achieved using subcutaneous MedRod implants that released either the low active estrone (E1) precursor or vehicle. A subgroup of E1 supplemented mice received daily oral gavage of FP4643, a well-characterized 17β-HSD-1 inhibitor. Bioluminescence imaging (BLI) was used to measure tumor growth non-invasively. At sacrifice, mice receiving E1 and treated with the FP4643 inhibitor showed a significant reduction in tumor growth by approximately 65% compared to mice receiving E1. Tumors exhibited metastatic spread to the peritoneum, to the lymphovascular space (LVI), and to the thoracic cavity. Metastatic spread and LVI invasion were both significantly reduced in the inhibitor-treated group. Transcriptional profiling of tumors indicated that FP4643 treatment reduced the oncogenic potential at the mRNA level. In conclusion, we show that 17β-HSD-1 inhibition represents a promising novel endocrine treatment for EC.

Evaluation of 17β-hydroxysteroid dehydrogenase activity using androgen receptor-mediated transactivation

17β-Hydroxysteroid dehydrogenases (17β-HSDs) catalyze the reduction of 17-ketosteroids and the oxidation of 17β-hydroxysteroids to regulate the production of androgens and estrogens. Among them, 17β-HSD type 3 (HSD17B3) is expressed almost exclusively in testicular Leydig cells and contributes to development of male sexual characteristics by converting androstenedione (A4) to testosterone (T). Mutations of HSD17B3 genes cause a 46,XY disorder of sexual development (46,XY DSD) as a result of low T production. Therefore, the evaluation of 17β-HSD3 enzymatic activity is important for understanding and diagnosing this disorder. We adapted a method that easily evaluates enzymatic activity of 17β-HSD3 by quantifying the conversion from A4 to T using androgen receptor (AR)-mediated transactivation. HEK293 cells were transduced to express human HSD17B3, and incubated medium containing A4. Depending on the incubation time with HSD17B3-expressing cells, the culture media progressively increased luciferase activities in CV-1 cells, transfected with the AR expression vector and androgen-responsive reporter. Culture medium from HSD17B1 and HSD17B5-expressing cells also increased the luciferase activities. This system is also applicable to detect the conversion of 11-ketoandrostenedione to 11-ketotestosterone by HSD17B3. Establishment of HEK293 cells expressing various missense mutations in the HSD17B3 gene associated with 46,XY DSD revealed that this system is effective to evaluate the enzymatic activities of mutant proteins.