Inflammatory regulation of steroid sulfatase: A novel mechanism to control estrogen homeostasis and inflammation in chronic liver disease.

BACKGROUND & AIMS: Chronic inflammatory liver diseases are associated with estrogen excess and feminization in men, which is thought to be due to compromised liver function to break down estrogens. The goal of this study is to determine whether the inflammatory induction of steroid sulfatase (STS), which converts inactive estrogen sulfates to active estrogens, may have contributed to the estrogen excess in chronic liver disease. METHODS: We performed bioinformatic analysis, real-time PCR, immunohistochemistry, and UPLC/MS-MS to analyze hepatic STS expression and serum estrogen levels in patients with chronic liver diseases. The crosstalk between NF-κB pathway and STS-regulated estrogen signaling was investigated by electrophoretic mobility shift assay, chromatin immunoprecipitation, luciferase assay and gene knockdown experiments in human hepatocytes. RESULTS: Hepatic STS was induced in patients with chronic inflammatory liver diseases, which was accompanied by increased circulating estrogen levels. The human STS gene, but not the mouse Sts gene, was induced by inflammatory stimuli in hepatic cells. Mechanistically, STS was established as a novel NF-κB target gene, whose induction facilitated the conversion of inactive estrogen sulfates to active estrogens, and consequently attenuated the inflammatory response. In contrast, genetic or pharmacological inhibition of STS or a direct blockade of estrogen signaling sensitized liver cells to the transcriptional activation of NF-κB and inflammatory response, possibly through the inhibition of IκB kinase activation. CONCLUSIONS: Our results suggest a negative feedback loop in chronic inflammatory liver diseases, in which the inflammatory activation of NF-κB induces STS gene expression. The induced STS facilitates the conversion of inactive estrogen sulfates to active estrogens, which in return attenuates the NF-κB-mediated inflammation.

Novel homozygous deletion of segmental KAL1 and entire STS cause Kallmann syndrome and X-linked ichthyosis in a Chinese family.

Kallmann syndrome (KS) is a genetically heterogeneous disease characterised by hypogonadotrophic hypogonadism in association with anosmia or hyposmia. This condition affects 1 in 10 000 men and 1 in 50,000 women. Defects in seventeen genes including KAL1 gene contribute to the molecular basis of KS. We report the clinical characteristics, molecular causes and treatment outcome of two Chinese brothers with KS and X-linked ichthyosis. The phenotypes of the patients were characterised by bilateral cryptorchidism, unilateral renal agenesis in one patient but normal kidney development in another. The patients had low serum testosterone, follicle-stimulating hormone and luteinising hormone levels and a blunt response to the gonadotrophin-releasing hormone stimulation test. After human chorionic gonadotrophin treatment, the serum testosterone levels were normalized, and the pubic hair, penis length and testicular volumes were greatly improved in both of the patients. The two affected siblings had the same novel deletion at Xp22.3 including exons 9-14 of KAL1 gene and entire STS gene. Our study broadens the mutation spectrum in the KAL1 gene associated with KS and facilitates the genetic diagnosis and counselling for KS.

Steroid sulfatase is a potential modifier of cognition in attention deficit hyperactivity disorder.

Deletions encompassing the X-linked STS gene (encoding steroid sulfatase) have been observed in subjects with neurodevelopmental disorders, including attention deficit hyperactivity disorder (ADHD). Recently, two single nucleotide polymorphisms (SNPs) within STS (rs12861247 and rs17268988) have been reported to be associated with ADHD risk and inattentive symptoms in ADHD, respectively. Using a UK sample of ADHD subjects (aged 5-18 years), we tested the hypothesis that rs12861247 is associated with ADHD risk using a case-control approach (comparing 327 ADHD cases with 358 male controls from the Wellcome Trust Case Control Consortium). Using a subset of males from the ADHD sample, we also examined whether variation within STS is associated with symptomatology/cognitive function in ADHD. We then tested whether SNPs associated with cognitive function in ADHD were also associated with cognitive function in healthy male subjects using a German sample (n = 143, aged 18-30 years), and whether STS was expressed in brain regions pertinent to ADHD pathology during development. We did not replicate the previously identified association with rs12861247. However, in ADHD males, variation at rs17268988 was associated with inattentive symptoms, while variation within STS was significantly associated with performance on three cognitive measures. Three SNPs associated with cognitive function in ADHD males were not associated with cognitive function in healthy males. STS was highly expressed in the developing cerebellar neuroepithelium, basal ganglia, thalamus, pituitary gland, hypothalamus and choroid plexus. These data suggest that genetic variants affecting STS expression and/or activity could influence the function of brain regions perturbed in ADHD.

Steroidogenic enzymes.

The enzymes and pathways of steroidogenesis are familiar to most endocrinologists, but the biochemistry and molecular biology of these processes are still being studied. This chapter outlines current knowledge about each enzyme. The quantitative regulation of steroidogenesis occurs at the first step, the conversion of cholesterol to pregnenolone. Chronic regulation is principally at the level of transcription of the gene for P450 side chain cleave (P450scc), which is the enzymatically rate-limiting step. Acute regulation is mediated by steroidogenic acute regulatory protein, which facilitates the rapid influx of cholesterol into mitochondria, where P450scc resides. Qualitative regulation, determining the class of steroid produced, is principally determined by P450c17. In the absence of P450c17 in the zona glomerulosa, C21 deoxy steroids are produced, leading to the mineralocorticoid aldosterone. In the presence of the 17alpha-hydroxylase but not the 17,20 lyase activity of P450c17 in the zona fasciculata, C21, 17-hydroxy steroids are produced, leading to the glucocorticoid cortisol. When both the 17alpha-hydroxylase and 17,20 lyase activities of P450c17 are present in the zona reticularis, the androgen precursor dehydroepiandrosterone is produced. The discrimination between 17alpha-hydroxylase and 17,20 lyase activities is regulated by two posttranslational events, the serine phosphorylation of P450c17 and the allosteric action of cytochrome b5, both of which act to optimize the interaction of P450c17 with its obligatory electron donor, P450 oxidoreductase.

Oestrogen producing enzymes and mammary carcinogenesis: a review.

There is a large and compelling body of epidemiological and experimental evidence that oestrogens are instrumental in the aetiology of breast cancer. Their mechanisms of action are varied, including stimulation of cellular proliferation through receptor-mediated hormonal activity, increasing genetic mutation rates through cytochrome P450-mediated metabolic activation, and induction of aneuploidy. The local biosynthesis of oestrogens especially in postmenopausal women is believed to play a very important role in the pathogenesis and development of hormone dependent breast carcinoma and the over-expression of regulatory enzymes seems to be associated with the development of a more aggressive disease and associated with poor outcome and increased local and distant recurrences. In this article we highlight the role of CYP19 gene expression and aromatase activity in mammary carcinogenesis. Other oestrogen producing (17-beta-hydroxysteroid dehydrogenase and steroid sulphatase) and catalyzing enzymes (3-beta-hydroxysteroid dehydrogenase, Oestrogen sulfotransferase, CYP1A1, CYP1B1, and CYP3A4) are also discussed in some detail. Understanding the mechanisms that regulate these enzymes is crucial to the development of new endocrine therapies in post-menopausal females with hormone dependant breast cancer. Currently, third generation aromatase inhibitors has revolutionized the treatment of oestrogen dependant breast cancer. However, the important role of both STS and 17-beta-HSD type 1 in local oestrogen production provides novel potential targets for endocrine therapy. Such endocrine therapy is currently being explored and the development of STS inhibitors, combined aromatase/steroid sulfatase inhibitors and 17-beta-HSD type 1 inhibitors is underway with promising initial results.

Biological roles of estrogen and progesterone in human endometrial carcinoma--new developments in potential endocrine therapy for endometrial cancer.

Endometrial carcinoma is one of the most common female pelvic malignancies. It is well known that uterine endometrial cell proliferation is under the control of both estrogen and progesterone. In this review, results of the recent studies on the biosynthesis and action of estrogen and progestin in normal endometrium and its disorders will be summarized and the new aspects of hormonal therapies in the patients with endometrial carcinoma will be discussed including its future prospectives. We reported that the enzymes responsible for intratumoral estrogen metabolism and biosynthesis are markedly different between human breast and endometrial carcinoma, although both of them are considered "estrogen-dependent malignancies". In addition, the biological significance of Progesterone receptor (PR) isoforms is considered to differ between endometrial and breast carcinomas. Clinical data concerning Hormone replacement therapy (HRT) and estrogen-dependent cancer risk also support these findings. These basic and clinical findings help to understand the biology and provide the new knowledge for prevention, diagnosis and treatment of human endomerial carcinoma. Specific endocrine treatment of endometrial carcinoma should be explored in future, although aromatase inhibitors are the most effective endocrine treatments of estrogen-responsive breast carcinoma. Retinoid, metabolities of vitamin A, and synthetic peroxisome proliferator-activated receptor (PPAR) gamma ligands, which have been used for the treatment of insulin resistance in type II diabetes mellitus, may be the important candidates as drugs not only for prevention but also for possible endocrine treatment of endometrial carcinoma.

Dehydroepiandrosterone sulphate sulphohydrolase [correction of sulphoydrolase] from human placenta microsomes--properties of the purified enzyme.

A form of steroid sulphate sulphohydrolase (EC 3.1.6.2) hydrolysing the dehydroepiandrosterone sulphate (DHEAS-ase) was purified from human placenta microsomes. During the purification procedure the DHEAS-ase was separated from the oestrone sulphate sulphohydrolase (OS-ase). The purified DHEAS-ase revealed specific activity of 1520 nmolxmin-1xmgprotein-1 and exhibited optimal activity at pH 8.4. The Km value was established to be 3.3+/-0.07x10(-5) M. The pI value was around 8.7. The molecular weight estimated by gel filtration was 7.4 kDa. The purified DHEAS-ase was not sensitive to the common sulphohydrolase inhibitors, such as phosphate, sulphate and sulphide ions, but was inhibited by several phosphohydrolase inhibitors (ammonium molybdate, vanadium oxide(V), zinc acetate). Steroids effected inhibition or activation of the purified enzyme. The data concerning substances reacting with -SH groups suggest that in the physiological conditions DHEAS-ase is controlled by the redox status of the cell.

Apoptosis related to steroid sulfatase at the cone-shaped projection in nephron morphogenesis.

Steroid sulfatase (STS) is a microsomal enzyme catalysing the hydrolysis of steroid 3beta-sulfates, including estrogen sulfate, at organ target sites. Steroid sulfatase activity, as well as the activity of various estrogens, has been reported to influence the development of organs. In the kidney, progenitor cells of nephrons develop from mesenchymal cells and finally attach to the ureteric duct at the region termed the cone-shaped projection. However, the mechanisms of this process have not been fully investigated. In the present study, STS-related apoptosis occurring between the renal vesicle and ureteric duct was examined using immunohistochemical techniques. Immunoreactivity to STS was demonstrated at the cortical metanephric mesenchyme surrounding new vessels and was pronounced at the junction between the renal vesicle and ureteric duct (cone-shaped junction). Steroid sulfatase-transfected LLC-RK1 cells (rat proximal cell line) were also examined in vitro. Apoptosis occurred when an estrogen precursor (ELS) was added at concentrations between 10(-4) and 10(-2) mol/L. These results indicate that STS is synthesized in the progenitor cells of proximal tubules. Moreover, STS may be related to apoptosis occurring at the junction between the renal vesicle and ureteric duct in a manner proportional to the availability of STS precursors.

Steroid sulfatase and estrogen sulfotransferase in human prostate cancer.

BACKGROUND: Estrogen sulfotransferase (EST) and steroid sulfatase (STS) are known to be involved in in situ estrogen production in estrogen dependent human cancer such as breast cancer, but unknown in prostate cancer. MATERIALS AND METHODS: We first examined whether these enzymes above were expressed and actually involved in estrogen production and metabolism in prostate cancer cell lines (LNCaP, DU-145, and PC-3). We than examined the expression of EST and STS in human prostate cancer tissues obtained from surgery (n = 52) using immunohistochemistry. RESULTS: mRNAs of both enzymes were detected in all prostate cancer cell lines examined, and the synthesis of estrone (E(1)) and estradiol (E(2)) was also confirmed in these cell lines. In addition, STS immunoreactivity was detected in 44 cases (85%) and EST in 39 cases (75%), respectively. CONCLUSIONS: STS and EST are expressed and may be involved in local production and metabolism of estrogens in human prostate cancers.

Strong expression of steroid sulfatase in human cumulus cells in patients with endometriosis.

OBJECTIVE: To investigate the localization and expression of steroid sulfatase (STS) in cumulus cells obtained from subjects with and without endometriosis. DESIGN: Case-control study. SETTING: In vitro fertilization program at the Showa University School of Medicine. PATIENT(S): Cumulus cells (142 samples) were obtained from 49 patients for whom IVF was indicated. Some of these samples were taken from cases complicated by endometriosis (35 samples), polycystic ovary syndrome (PCOS; 16 samples), or latent hyperprolactinemia (16 samples). INTERVENTION(S): Immunohistochemical staining for STS. Measurement of STS mRNA expression by real-time polymerase chain reaction (PCR). MAIN OUTCOME MEASURE(S): Expression of STS mRNA and localization of STS. RESULT(S): Steroid sulfatase was localized in the cytoplasm of the cumulus cells, and expression of STS mRNA was observed. The expression level of STS mRNA from patients with endometriosis was significantly higher (11.8-fold) than that of patients without endometriosis. CONCLUSION(S): These results suggest a local steroidal regulation mechanism in cumulus cells. Although the physiological role of STS in cumulus cells remains unclear, STS may be involved in the quality of eggs in patients with endometriosis.

The potential function of steroid sulphatase activity in steroid production and steroidogenic acute regulatory protein expression.

The first step in the biosynthesis of steroid hormones is conversion of cholesterol into pregnenolone. StAR (steroidogenic acute regulatory) protein plays a crucial role in the intra-mitochondrial movement of cholesterol. STS (steroid sulphatase), which is present ubiquitously in mammalian tissues, including the placenta, adrenal gland, testis and ovary, desulphates a number of 3beta-hydroxysteroid sulphates, including cholesterol sulphate. The present study was designed to examine the effect of STS on StAR protein synthesis and steroidogenesis in cells. Steroidogenic activities of COS-1 cells that had been co-transfected with a vector for the cholesterol P450scc (cytochrome P450 side-chain-cleavage enzyme) system, named F2, a StAR expression vector (pStAR), and an STS expression vector (pSTS) were assayed. Whole-cell extracts were subjected to SDS/PAGE and then to Western blot analysis. pSTS co-expressed in COS-1 cells with F2 and pStAR increased pregnenolone synthesis 2-fold compared with that of co-expression with F2 and pStAR. Western blot analysis using COS-1 cells that had been co-transfected with pSTS, F2 and pStAR revealed that StAR protein levels increased, whereas STS and P450scc protein levels did not change. The amount of StAR protein translation products increased when pSTS was added to an in vitro transcription-translation reaction mixture. Pulse-chase experiments demonstrated that the 37 kDa StAR pre-protein disappeared significantly ( P <0.01) more slowly in COS-1 cells that had been transfected with pSTS than in COS-1 cells that had not been transfected with pSTS. The increase in StAR protein level is not a result of an increase in StAR gene expression, but is a result of both an increase in translation and a longer half-life of the 37 kDa pre-StAR protein. In conclusion, STS increases StAR protein expression level and stimulates steroid production.