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Showing papers on "Hydroxysteroid dehydrogenase published in 2005"


Journal ArticleDOI
TL;DR: This versatile enzyme might provide a new drug target for neuronal excitability control and for intervention in Alzheimer's disease and certain cancers.
Abstract: Human 17β-hydroxysteroid dehydrogenase type 10 (17β-HSD10) is a mitochondrial enzyme encoded by the SCHAD gene, which escapes chromosome X inactivation 17β-HSD10/SCHAD mutations cause a spectrum of clinical conditions, from mild mental retardation to progressive infantile neurodegeneration 17β-HSD10/SCHAD is essential for the metabolism of isoleucine and branched-chain fatty acids It can inactivate 17β-estradiol and steroid modulators of GABA A receptors, and convert 5α-androstanediol into 5α-dihydrotestosterone (DHT) Certain malignant prostatic epithelial cells contain high levels of 17β-HSD10, generating 5α-DHT in the absence of testosterone 17β-HSD10 has an affinity for amyloid-β peptide, and might be linked to the mitochondrial dysfunction seen in Alzheimer's disease This versatile enzyme might provide a new drug target for neuronal excitability control and for intervention in Alzheimer's disease and certain cancers

106 citations


Journal ArticleDOI
TL;DR: The evidence linking cofactor handling and HSD activity is reviewed, additional ways that intracellular metabolism can alter H SD activity and, thus, hormone potency are speculated, and fruitful avenues of further investigation are discussed.
Abstract: Hydroxysteroid dehydrogenases (HSDs) interconvert potent and relatively inactive forms of individual steroid hormones using nicotinamide cofactors NADPH/NADP(+) and NADH/NAD(+) [nicotinamide adenine dinucleotide (phosphate), reduced/oxidized forms]. Although reactions with purified enzymes in vitro may be driven in either direction depending on the assay conditions, HSD enzymes appear to function in one direction or the other in intact cells. At least for some of these enzymes, however, the apparent unidirectional metabolism actually reflects bidirectional catalysis that reaches a pseudoequilibrium state with a strong directional preference. This directional preference, in turn, derives from intracellular concentration gradients for the nicotinamide cofactors and the relative affinities of each HSD for these cofactors. Because the concentrations of free cofactor exceed those of steroids by many orders of magnitude, the activities of these enzymes are predominantly driven by cofactor abundance, which is linked to intermediary metabolism. Consequently, the amount of active steroids in cells containing HSDs may be modulated by cofactor abundance and, hence, intracellular redox state. We will review the evidence linking cofactor handling and HSD activity, speculate on additional ways that intracellular metabolism can alter HSD activity and, thus, hormone potency, and discuss fruitful avenues of further investigation.

106 citations


Journal ArticleDOI
TL;DR: The identification and characterization of the zebrafish homolog of 17beta-HSD type 3 is described and it is found that both enzymes can reduce 11-ketoandrostenedione as well as 11beta-hydroxyandrosthenione at C-17 to the respective testosterone forms.
Abstract: Formation and inactivation of testosterone is performed by various members of the 17beta-hydroxysteroid dehydrogenase (17beta-HSD) family. The main player in testosterone formation is considered to be 17beta-HSD type 3, which catalyzes the reduction of androstenedione to testosterone with high efficiency and is almost exclusively expressed in testis. So far, only the mammalian homologs have been characterized but nothing is known about the role of 17beta-HSD type 3 in other vertebrates. In this study, we describe the identification and characterization of the zebrafish homolog. We found zebrafish 17beta-HSD type 3 to be expressed in embryogenesis from sphere to 84 h post-fertilization. Expression was also detected in various tissues of both male and female adults, but displayed sexual dimorphism. Interestingly, expression was not highest in male testis but in male liver. In female adults, strongest expression was observed in ovaries. At the subcellular level, both human and zebrafish 17beta-HSD type 3 localize to the endoplasmic reticulum. The zebrafish enzyme in vitro effectively catalyzed the conversion of androstenedione to testosterone by use of NADPH as cofactor. Among further tested androgens epiandrosterone and dehydroepiandrosterone were accepted as substrates and reduced at C-17 by the human and the zebrafish enzyme. Androsterone and androstanedione though, were only substrates of human 17beta-HSD type 3, not the zebrafish enzyme. Furthermore, we found that both enzymes can reduce 11-ketoandrostenedione as well as 11beta-hydroxyandrostenedione at C-17 to the respective testosterone forms. Our results suggest that 17beta-HSD type 3 might play slightly different roles in zebrafish compared with human although testosterone itself is likely to have similar functions in both organisms.

92 citations


Journal ArticleDOI
TL;DR: Mounting evidence obtained from both preclinical and clinical studies support the contention that inhibiting 11βHSD1 will have a therapeutic benefit by lowering glucose output and increasing insulin sensitivity.
Abstract: 11β-Hydroxysteroid dehydrogenase-1 (11βHSD1) is a therapeutic target for Type 2 diabetes that has stimulated the interest of many pharmaceutical companies. Mounting evidence obtained from both preclinical and clinical studies support the contention that inhibiting 11βHSD1 will have a therapeutic benefit by lowering glucose output and increasing insulin sensitivity. In just over two years, 21 applications containing 11βHSD1 inhibitors have been published. In this review, the target rationale and patent applications from Merck, Novo Nordisk, AstraZeneca, Sterix, Biovitrum, Janssen and Novartis will be discussed.

78 citations


Patent
16 Dec 2005
TL;DR: In this article, the authors provided compounds of formula I that are useful as potent and selective inhibitors of 11-beta hydroxysteroid dehydrogenase 1 (HBDE) and a pharmaceutical composition which comprises a compound of Formula I, or a pharmaceutical salt thereof, and a pharmaceutically acceptable carrier, diluent, or excipient.
Abstract: The present invention provides compounds of formula I that are useful as potent and selective inhibitors of 11-beta hydroxysteroid dehydrogenase 1. The present invention further provides a pharmaceutical composition which comprises a compound of Formula I, or a pharmaceutical salt thereof, and a pharmaceutically acceptable carrier, diluent, or excipient. In addition, the present invention compositions containing these compounds for the treatment of metabolic syndrome, diabetes, hyperglycemia, obesity, hypertension, hyperlipidemia, other symptoms associated with hyperglycemia, and related disorders. Formula I wherein G1 is methylene or ethylene; L is-(C1-C4)alkylene-, -S-, -CH(OH)-, or -O-; R0 is Formula II or Formula III and the other substituents are as defined in the claims.

67 citations


Journal ArticleDOI
TL;DR: Evidence suggests that 17beta-HSD10 is the brain enzyme capable of catalyzing the oxidation of steroid modulators of GABA(A) receptors.

52 citations


Journal ArticleDOI
TL;DR: Estrogen sulfotransferase, the enzyme that inactivates estrogen, has been found selectively expressed in male tissues, thus suggesting a role for this enzyme to protect male-specific tissues against estrogenic activity.

52 citations


Journal ArticleDOI
01 May 2005-Placenta
TL;DR: Evidence is provided that CCT and IS cells participate in P and estrogen biosynthesis, in addition to ST cells, which may provide an optimal level of P for the maintenance and progression of pregnancy.

34 citations


Journal ArticleDOI
TL;DR: This study describes the isolation and characterization of the enzyme 17α-hydroxysteroid dehydrogenase and permits to clarify the biosynthesis pathway of epiT and offers the opportunity to study gene regulation and function of this enzyme.
Abstract: Epi-testosterone (epiT) is the 17α-epimer of testosterone. It has been found at similar level as testosterone in human biological fluids. This steroid has thus been used as a natural internal standard for assessing testosterone abuse in sports. EpiT has been also shown to accumulate in mammary cyst fluid and in human prostate. It was found to possess antiandrogenic activity as well as neuroprotective effects. So far, the exact pathway leading to the formation of epiT has not been elucidated. In this report, we describe the isolation and characterization of the enzyme 17α-hydroxysteroid dehydrogenase. The name is given according to its most potent activity. Using cells stably expressing the enzyme, we show that 17α-HSD catalyzes efficienty the transformation of 4-androstenedione (4-dione), dehydroepiandrosterone (DHEA), 5α-androstane-3,17-dione (5α-dione) and androsterone (ADT) into their corresponding 17α-hydroxy-steroids : epiT, 5-androstene-3β,17α-diol (epi5diol), 5α-androstane-17α-ol-3-one (epiDHT) and 5α-androstane-3α,17α-diol (epi3α-diol), respectively. Similar to other members of the aldo-keto reductase family that possess the ability to reduce the keto-group into hydroxyl-group at different position on the steroid nucleus, 17α-HSD could also catalyze the transformation of DHT, 5α-dione, and 5α-pregnane-3,20-dione (DHP) into 3α-diol, ADT and 5α-pregnane-3α-ol-20-one (allopregnanolone) through its less potent 3α-HSD activity. We also have over-expressed the 17α-HSD in Escherichia coli and have purified it by affinity chromatography. The purified enzyme exhibits the same catalytic properties that have been observed with cultured HEK-293 stably transfected cells. Using quantitative Realtime-PCR to study tissue distribution of this enzyme in the mouse, we observed that it is expressed at very high levels in the kidney. The present study permits to clarify the biosynthesis pathway of epiT. It also offers the opportunity to study gene regulation and function of this enzyme. Further study in human will allow a better comprehension about the use of epiT in drug abuse testing; it will also help to clarify the importance of its accumulation in breast cyst fluid and prostate, as well as its potential role as natural antiandrogen.

34 citations



Journal ArticleDOI
01 Aug 2005-Steroids
TL;DR: Docking the representative inhibitors chrysin and kaempferol into the active site of 17beta-HSDcl revealed the possible binding mode, in which they are sandwiched between the nicotinamide moiety and Tyr212, similar to the reported structural features of phytoestrogen inhibitors of human 17 beta- HSD types 1 and 2.

Journal ArticleDOI
01 Jul 2005-Steroids
TL;DR: It is demonstrated that phytochemicals have the potential to inhibit 5alpha-DHT metabolism and thereby affect the androgen status of the human lung.

Journal ArticleDOI
TL;DR: In this paper, the authors showed that the high levels of type II 17beta-hydroxysteroid dehydrogenase (17beta-HSD) present in ZR-75-1 cells were largely responsible for the facile conversion of 2-MeO-E2 to 2-methoxyestrone and also for the selective insensitivity to other nonsteroidal anticancer agents.
Abstract: 2-Methoxyestradiol (2-MeO-E2), a nonpolar endogenous metabolite of 17beta-estradiol, has strong antiproliferative, apoptotic, and antiangiogenic actions. Among the four human breast cancer cell lines tested (MCF-7, T-47D, ZR-75-1, and MDA-MB-435s), the ZR-75-1 cells were selectively insensitive to the antiproliferative actions of 2-MeO-E2, although these cells had a similar sensitivity as other cell lines to several other anticancer agents (5-fluorouracil, mitomycin C, doxorubicin, colchicine, vinorelbine, and paclitaxel). Mechanistically, this insensitivity is largely attributable to the presence of high levels of a steroid-selective metabolizing enzyme, the type II 17beta-hydroxysteroid dehydrogenase (17beta-HSD), in the ZR-75-1 cells, which rapidly converts 2-MeO-E2 to the inactive 2-methoxyestrone, but this enzyme does not metabolically inactivate other nonsteroidal anticancer agents. The type II 17beta-HSD-mediated conversion of 2-MeO-E2 to 2-methoxyestrone in ZR-75-1 cells followed the first-order kinetics, with a very short half-life (approximately 2 hours). In comparison, the T-47D, MCF-7, and MDA-MB-435s human breast cancer cells, which were highly sensitive to 2-MeO-E2, had very low or undetectable catalytic activity for the conversion of 2-MeO-E2 to 2-methoxyestrone. Reverse transcription-PCR analysis of the mRNA levels of three known oxidative 17beta-HSD isozymes (types II, IV, and VIII) revealed that only the type II isozyme was selectively expressed in the ZR-75-1 cells, whereas the other two isozymes were expressed in all four cell lines. Taken together, our results showed, for the first time, that the high levels of type II 17beta-HSD present in ZR-75-1 cells were largely responsible for the facile conversion of 2-MeO-E2 to 2-methoxyestrone and also for the selective insensitivity to the antiproliferative actions of 2-MeO-E2.

Journal ArticleDOI
TL;DR: The present data suggest that type 8 17β-HSD can exert its action to downregulate E2 levels in a large variety of tissues.
Abstract: The enzyme type 8 17β-hydroxysteroid dehydrogenase (17β-HSD) selectively catalyzes the conversion of estradiol (E2) to estrone (E1). To obtain detailed information on the sites of action of type 8 17β-HSD, we have studied the cellular localization of type 8 17β-HSD mRNA in mouse tissues using in situ hybridization. In the ovary, hybridization signal was detected in granulosa cells of growing follicles and luteal cells. In the uterus, type 8 17β-HSD mRNA was found in the epithelial (luminal and glandular) and stromal cells. In the female mammary gland, the enzyme mRNA was seen in ductal epithelial cells and stromal cells. In the testis, hybridization signal was observed in the seminiferous tubule. In the prostate, type 8 17β-HSD was detected in the epithelial cells of the acini and stromal cells. In the clitoral and preputial glands, labeling was detected in the epithelial cells of acini and small ducts. The three lobes of the pituitary gland were labeled. In the adrenal gland, hybridization signal was obs...

Patent
28 Feb 2005
TL;DR: Fused heterotricyclic compounds, methods of using such compounds in the treatment of hormone sensitive diseases such as prostate cancer, and pharmaceutical compositions containing such compounds are discussed in this paper.
Abstract: Fused heterotricyclic compounds, methods of using such compounds in the treatment of hormone sensitive diseases such as prostate cancer, and pharmaceutical compositions containing such compounds.

Journal ArticleDOI
TL;DR: Experiments showed that vitamin K2 binds 17beta hydroxysteroid dehydrogenase 4 and decreases the intracellular estradiol:estrone ratio, which resulted in the inhibition of the amount of estrogen receptor alpha-binding to its target DNA, suggesting a possible novel role for vitamin K in modulating estrogen function.

Journal ArticleDOI
TL;DR: The more extensive and specific interactions of 17beta-HSD_8 with the BKR substrate compared to interactions with estradiol raise a serious question about the enzyme's primary function in vivo and suggest that it is likely to be involved in the regulation of fatty acid metabolism rather than in the steroid-dependent activity that has been demonstrated in vitro.

Journal ArticleDOI
TL;DR: Addition of a negatively-charged amino acid residue at the first position after the second beta-strand affected the coenzyme specificity and turned the enzyme into an NAD+-dependent oxidase resembling the cD1d subfamily members.

Journal ArticleDOI
TL;DR: It is shown by site-directed mutagenesis and structure/function analysis that 17β-HSDcl dimerization involves the αE and αF helices of both subunits, which is a prerequisite for catalysis.
Abstract: Background 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl) is a member of the short-chain dehydrogenase/reductase (SDR) superfamily. SDR proteins usually function as dimers or tetramers and 17β-HSDcl is also a homodimer under native conditions.

Journal ArticleDOI
TL;DR: The discovery of 4,5-disubstituted cis-pyrrolidinones as 17β-HSD II inhibitors led to the development of an efficient intramolecular Michael addition, followed by catalytic hydrogenation to obtain the desired cis configuration as discussed by the authors.

Journal ArticleDOI
TL;DR: The promoter elements involved in the basal expression of PRAP/17betaHSD7 are identified and it is found that LH-mediated repression of this gene is at the level of transcription and involves inhibition of nuclear factor YA binding to the CCAAT site within the proximal promoter.
Abstract: Prolactin receptor-associated protein (PRAP) originally cloned in our laboratory was shown to be a novel, luteal isoform of 17β hydroxysteroid dehydrogenase 7 (17βHSD7). In this study, we cloned the promoter region of rat PRAP/17βHSD7 and investigated the mechanisms regulating both basal activity and LH-induced repression of this promoter. Truncated and site-specific mutants of PRAP/17βHSD7 promoter identified two enhancer regions that contained highly conserved Sp1 binding site and bound Sp1 from nuclear extracts of both corpora lutea and a rat luteal cell line. Repression of PRAP/17βHSD7 expression and promoter activity by human chorionic gonadotropin/forskolin was localized to a −52-bp proximal segment of the promoter. This region contained a conserved CCAAT site and bound nuclear factor Y; binding of this transcription factor was inhibited by human chorionic gonadotropin in vivo. Furthermore, mutation of the nuclear factor Y site in the −52-bp promoter-reporter construct abolished forskolin-mediated i...

Journal ArticleDOI
TL;DR: The data indicate that androgens and estrogens are formed via the action of type 5 17β-HSD in specific cell types in the liver, ovary, adrenal cortex, and kidney.
Abstract: The mouse enzyme type 5 17β-hydroxysteroid dehydrogenase (17β-HSD) catalyzes the conversion of androstenedione to testosterone and, to a lesser degree, the conversion of estrone to estradiol. In order to determine the exact sites of action of type 5 17β-HSD, we studied the cellular localization of the mRNA of the enzyme in mouse tissues by using in situ hybridization. Specific hybridization signal was found in the liver, ovary, adrenal cortex, and kidney. In the liver of mice of both sexes, a strong signal was observed in all hepatocytes. In the ovary, specific labeling was detected in the granulosa and theca interna cells in growing follicles and in luteal cells. In the female adrenal cortex, intense labeling was restricted to the zona reticularis, whereas no type 5 17β-HSD mRNA expression could be found in the male adrenal cortex. In the kidney of mice of both sexes, type 5 17β-HSD mRNA was expressed in epithelial cells in both the proximal and distal convoluted tubules. The data indicate that androgens and estrogens are formed via the action of type 5 17β-HSD in specific cell types in the liver, ovary, adrenal cortex, and kidney.

Journal ArticleDOI
TL;DR: An X-ray crystallographic study has been undertaken and the optimal conditions for crystallization of 17beta-HSDcl (apo form) were established, resulting in well shaped crystals that diffracted to 1.7 A resolution.
Abstract: 17β-Hydroxysteroid dehydrogenase from the filamentous fungus Cochliobolus lunatus (17β-HSDcl) is an NADP(H)-dependent enzyme that preferentially catalyses the oxidoreduction of oestrogens and androgens. The enzyme belongs to the short-chain dehydrogenase/reductase superfamily and is the only fungal hydroxysteroid dehydrogenase known to date. 17β-HSDcl has recently been characterized and cloned and has been the subject of several functional studies. Although several hypotheses on the physiological role of 17β-HSDcl in fungal metabolism have been formulated, its function is still unclear. An X-ray crystallographic study has been undertaken and the optimal conditions for crystallization of 17β-HSDcl (apo form) were established, resulting in well shaped crystals that diffracted to 1.7 A resolution. The space group was identified as I4122, with unit-cell parameters a = b = 67.14, c = 266.77 A. Phasing was successfully performed by Patterson search techniques. A catalytic inactive mutant Tyr167Phe was also engineered, expressed, purified and crystallized for functional and structural studies.

Journal ArticleDOI
TL;DR: The results suggest that BRE influences steroidogenesis through its effects on 3beta-HSD action, probably affecting its transcription.
Abstract: Conversion of cholesterol to biologically active steroids is a multi-step enzymatic process. Along with some important enzymes, like cholesterol side-chain cleavage enzyme (P450scc) and 3beta-hydroxysteroid dehydrogenase/isomerase (3beta-HSD), several proteins play key role in steroidogenesis. The role of steroidogenic acute regulatory (StAR) protein is well established. A novel protein, BRE, found mainly in brain, adrenals and gonads, was highly expressed in hyperplastic rat adrenals with impaired steroidogenesis, suggesting its regulation by pituitary hormones. To further elucidate its role in steroidogenic tissues, mouse Leydig tumor cells (mLTC-1) were transfected with BRE antisense probes. Morphologically the BRE antisense cells exhibited large cytoplasmic lipid droplets and failed to shrink in response to human chorionic gonadotropin. Although cAMP production, along with StAR and P450scc mRNA expression, was unaffected in BRE antisense clones, progesterone and testosterone yields were significantly decreased, while pregnenolone was increased in response to human chorionic gonadotropin stimulation or in the presence of 22(R)OH-cholesterol. Furthermore, whereas exogenous progesterone was readily converted to testosterone, pregnenolone was not, suggesting impairment of pregnenolone-to-progesterone conversion, a step metabolized by 3beta-HSD. That steroidogenesis was compromised at the 3beta-HSD step was further confirmed by the reduced expression of 3beta-HSD type I (3ss-HSDI) mRNA in BRE antisense cells compared with controls. Our results suggest that BRE influences steroidogenesis through its effects on 3beta-HSD action, probably affecting its transcription.

Journal ArticleDOI
TL;DR: This study examined and compared the 5' flanking regions (promoter regions) of human and murine 17beta-hydroxysteroid dehydrogenase type 7 genes and provided new insights to the transcriptional regulation of HSD17B7 and further hints to its involvement in cholesterol biosynthesis.

Journal ArticleDOI
TL;DR: Results suggest that 17-HSD4 is involved in estrogen inactivation and may protect against an excessive accumulation of E 2 in hOSE cells.
Abstract: The human ovarian surface epithelium (hOSE) is a single layer of mesothelial-type primitive epithelial cells that are potential estrogen targets. It has been reported that hOSE cells can produce estrogen. However, the mechanisms that regulate estrogen level(s) in hOSE cells are not yet known. To elucidate the enzymes involved in these reactions, we examined gene expression of 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) in primary hOSE (POSE) and OSE2a cells using RT-PCR. We found that POSE cells and cells of the immortalized hOSE line, OSE2a, bidirectionally converted estrone (E1) and 17beta-estradiol (E2). Both cell types expressed mRNA for 17beta-HSD type 1 (17beta-HSD1), suggesting that the enzyme is involved in the E1 to E2 conversion. Interestingly, both cells expressed 17beta-HSD4 mRNA but not 17beta-HSD2 mRNA. We prepared an antibody against the carboxyl terminal of 17beta-HSD4 (anti-17beta-HSD4 antibody), which recognized the 80 and 48 kDa proteins in POSE and OSE2a cells based on immunoblot analysis. Furthermore, immunohistochemical study revealed the presence of 17beta-HSD4 in hOSE cells in the human ovary. These results suggest that 17beta-HSD4 is involved in estrogen inactivation and may protect against an excessive accumulation of E2 in hOSE cells.

Patent
30 Mar 2005
TL;DR: The use of 11-Beta Hydroxysteroid Dehydrogenase Type 1 may be a common molecular etiology for visceral obesity and the metabolic syndrome of obesity as well as a treatment for diabetes, especially type II diabetes as mentioned in this paper.
Abstract: This invention is directed to the discovery that 11-Beta Hydroxysteroid Dehydrogenase Type 1 may be a common molecular etiology for visceral obesity and the metabolic syndrome of obesity as well a treatment for diabetes, especially type II diabetes. The present invention also relates to the use of certain compounds as inhibitors of 17-Beta Hydroxysteroid Dehydrogenase Type 1 and their use for the treatment of cancer, especially breast cancer.


Journal ArticleDOI
TL;DR: It is suggested that in addition to 20β-HSD, the CYP17 might have a role in the shift in steroidogenesis during meiotic maturation of snake head murrel.
Abstract: Partial cDNAs encoding carbonyl reductase like 20β-hydroxysteroid dehydrogenase (20β-HSD) and P450 17α-hydroxylase/c17–20 lyase (CYP17) were isolated from the ovary of snake head murrel and they exhibited high sequence identity to the Nile tilapia and rainbow trout, respectively. A low transcript level of both 20β-HSD and CYP17 were detected in pre-vitellogenic follicles, while the transcript level was high in full-grown immature follicles. In hCG-induced in vitro oocyte maturation, we found a significant increase in 20β-HSD transcript level after 2 h. The CYP17 transcripts also showed a considerable increase following hCG-induction compared to saline-treated controls. On the other hand, Western blot analysis demonstrated no significant change in the CYP17 protein level during hCG-induced in vitro oocyte maturation. Taken together, we suggest that in addition to 20β-HSD, the CYP17 might have a role in the shift in steroidogenesis during meiotic maturation of snake head murrel.

01 Apr 2005
TL;DR: In this paper, the authors present a set of ACKNOWLEDGEMENTS 6 ABBREVIATIONS 8 of the following categories: 1.4 ACKnOWLEDGE
Abstract: 4 ACKNOWLEDGEMENTS 6 ABBREVIATIONS 8