Articles de revues : « HSDH »

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Gao, Miaomiao, Kaili Nie, Meng Qin, Haijun Xu, Fang Wang et Luo Liu. « Molecular Mechanism Study on Stereo-Selectivity of α or β Hydroxysteroid Dehydrogenases ». Crystals 11, n^o 3 (25 février 2021) : 224. http://dx.doi.org/10.3390/cryst11030224.

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Hydroxysteroid dehydrogenases (HSDHs) are from two superfamilies of short-chain dehydrogenase (SDR) and aldo–keto reductase (AKR). The HSDHs were summarized and classified according to their structural and functional differences. A typical pair of enzymes, 7α–hydroxysteroid dehydrogenase (7α–HSDH) and 7β–hydroxysteroid dehydrogenase (7β–HSDH), have been reported before. Molecular docking of 7-keto–lithocholic acid(7–KLA) to the binary of 7β–HSDH and nicotinamide adenine dinucleotide phosphate (NADP+) was realized via YASARA, and a possible binding model of 7β–HSDH and 7–KLA was obtained. The α side of 7–KLA towards NADP+ in 7β–HSDH, while the β side of 7–KLA towards nicotinamide adenine dinucleotide (NAD+) in 7α–HSDH, made the orientations of C7–OH different in products. The interaction between Ser193 and pyrophosphate of NAD(P)+ [Ser193–OG⋯3.11Å⋯O1N–PN] caused the upturning of PN–phosphate group, which formed a barrier with the side chain of His95 to make 7–KLA only able to bind to 7β–HSDH with α side towards nicotinamide of NADP+. A possible interaction of Tyr253 and C24 of 7–KLA may contribute to the formation of substrate binding orientation in 7β–HSDH. The results of sequence alignment showed the conservation of His95, Ser193, and Tyr253 in 7β–HSDHs, exhibiting a significant difference to 7α–HSDHs. The molecular docking of other two enzymes, 17β–HSDH from the SDR superfamily and 3(17)α–HSDH from the AKR superfamily, has furtherly verified that the stereospecificity of HSDHs was related to the substrate binding orientation.

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Wang, Rui, Jiaquan Wu, David Kin Jin, Yali Chen, Zhijia Lv, Qian Chen, Qiwei Miao, Xiaoyu Huo et Feng Wang. « Structure of NADP+-bound 7β-hydroxysteroid dehydrogenase reveals two cofactor-binding modes ». Acta Crystallographica Section F Structural Biology Communications 73, n^o 5 (26 avril 2017) : 246–52. http://dx.doi.org/10.1107/s2053230x17004460.

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In mammals, bile acids/salts and their glycine and taurine conjugates are effectively recycled through enterohepatic circulation. 7β-Hydroxysteroid dehydrogenases (7β-HSDHs; EC 1.1.1.201), including that from the intestinal microbeCollinsella aerofaciens, catalyse the NADPH-dependent reversible oxidation of secondary bile-acid products to avoid potential toxicity. Here, the first structure of NADP+bound to dimeric 7β-HSDH is presented. In one active site, NADP+adopts a conventional binding mode similar to that displayed in related enzyme structures. However, in the other active site a unique binding mode is observed in which the orientation of the nicotinamide is different. Since 7β-HSDH has become an attractive target owing to the wide and important pharmaceutical use of its product ursodeoxycholic acid, this work provides a more detailed template to support rational protein engineering to improve the enzymatic activities of this useful biocatalyst, further improving the yield of ursodeoxycholic acid and its other applications.

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Ferreira, Renato Rodrigues, Ariane Vendemiatti, Lyndel Wayne Meinhardt, Peter John Lea et Ricardo Antunes Azevedo. « Isolation of enzymes involved in threonine biosynthesis from sorghum seeds ». Brazilian Journal of Plant Physiology 16, n^o 2 (août 2004) : 95–104. http://dx.doi.org/10.1590/s1677-04202004000200005.

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Cereal seeds are poor in essential amino acids, particularly lysine, tryptophan and threonine. The amino acids lysine and threonine are synthesized in the aspartate pathway. Although most of the enzymes of the aspartate pathway have been isolated and characterized in higher plant species, the metabolism of lysine and threonine is totally unknown in sorghum. We have isolated two enzymes, aspartate kinase (AK) and homoserine dehydrogenase (HSDH) from sorghum. Optimum assay conditions were established for the determination of AK and HSDH activities. The highest level of activity was observed in immature seeds. AK was shown to be inhibited by threonine and lysine indicating the existence of at least two isoenzymes, one sensitive to threonine inhibition and the other sensitive to lysine inhibition with the latter being predominant in sorghum seeds. HSDH was shown to be inhibited by threonine indicating the existence of a threonine-sensitive HSDH, however, most of the activity was not inhibited by threonine, suggesting the existence of a second predominant isoenzyme of HSDH resistant to threonine inhibition.

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Prabha, V., Meenakshi Gupta et K. G. Gupta. « Kinetic properties of 7α-hydroxysteroid dehydrogenase from Escherichia coli 080 ». Canadian Journal of Microbiology 35, n^o 12 (1 décembre 1989) : 1076–80. http://dx.doi.org/10.1139/m89-180.

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Results on the kinetics of 7α-hydroxysteroid dehydrogenase 7α-HSDH showed that this enzyme could oxidize all bile acids having an –OH group at the C-7 position. Lineweaver-Burk plots showed Michaelis constant (Km) values of 0.83 and 0.12 mM for cholic acid and chenodeoxycholic acid, respectively. The effect of enzyme concentration on the reaction velocity showed a constant increase in the enzyme activity with increase in enzyme-protein concentration. 7α-HSDH was activated by Na+, K+, Ca2+, and Mn2+ ions and by reducing agents having a thiol group (dithiothreitol, 2-mercaptoethanol). Co2+, Hg2+, Fe3+, Mg2+, Zn2+, Ba2+, and Cu2+ ions, chelating agents (potassium oxalate, heparin, EDTA), oxidizing agents (sodium perchlorate, sodium periodate, sodium persulphate), and detergents (Tween 20, Tween 40, Tween 80, Triton X-100, sodium lauryl sulphate) were inhibitory to 7α-HSDH activity.Key words: 7α-hydroxysteroid dehydrogenase, bile acids, NAD+, Escherichia coli 080, enzyme kinetics.

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Ji, Qingzhi, Bochu Wang, Chou Li, Jinglan Hao et Wenjing Feng. « Co-immobilised 7α- and 7β-HSDH as recyclable biocatalyst : high-performance production of TUDCA from waste chicken bile ». RSC Advances 8, n^o 60 (2018) : 34192–201. http://dx.doi.org/10.1039/c8ra06798h.

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Isogai, Shota, et Hiroshi Takagi. « Enhancement of lysine biosynthesis confers high-temperature stress tolerance to Escherichia coli cells ». Applied Microbiology and Biotechnology 105, n^o 18 (29 août 2021) : 6899–908. http://dx.doi.org/10.1007/s00253-021-11519-0.

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Abstract Lysine, a nutritionally important amino acid, is involved in adaptation and tolerance to environmental stresses in various organisms. Previous studies reported that lysine accumulation occurs in response to stress and that lysine supplementation enhances stress tolerance; however, the effect of lysine biosynthesis enhancement on stress tolerance has yet to be elucidated. In this study, we confirmed that lysine supplementation to the culture medium increased intracellular lysine content and improved cell growth of Escherichia coli at high temperature (42.5 °C). Lysine-overproducing strains were then isolated from the lysine analogue S-adenosylmethionine-resistant mutants by conventional mutagenesis and exhibited higher tolerance to high-temperature stress than the wild-type strain. We identified novel amino acid substitutions Gly474Asp and Cys554Tyr on ThrA, a bifunctional aspartate kinase/homoserine dehydrogenase (AK/HSDH), in the lysine-overproducing mutants. Interestingly, the Gly474Asp and Cys554Tyr variants of ThrA induced lysine accumulation and conferred high-temperature stress tolerance to E. coli cells. Enzymatic analysis revealed that the Gly474Asp substitution in ThrA reduced HSDH activity, suggesting that the intracellular level of aspartate semialdehyde, which is a substrate for HSDH and an intermediate for lysine biosynthesis, is elevated by the loss of HSDH activity and converted to lysine in E. coli. The present study demonstrated that both lysine supplementation and lysine biosynthesis enhancement improved the high-temperature stress tolerance of E. coli cells. Our findings suggest that lysine-overproducing strains have the potential as stress-tolerant microorganisms and can be applied to robust host cells for microbial production of useful compounds. Key points • Lysine supplementation improved the growth of E. coli cells at high temperature. • The G474D and C554Y variant ThrA increased lysine productivity in E. coli cells. • The G474D substitution in ThrA reduced homoserine dehydrogenase activity. • E. coli cells that overproduce lysine exhibited high-temperature stress tolerance.

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Tsachaki, Maria, Arne Meyer, Benjamin Weger, Denise V. Kratschmar, Janina Tokarz, Jerzy Adamski, Heinz-Georg Belting, Markus Affolter, Thomas Dickmeis et Alex Odermatt. « Absence of 11-keto reduction of cortisone and 11-ketotestosterone in the model organism zebrafish ». Journal of Endocrinology 232, n^o 2 (février 2017) : 323–35. http://dx.doi.org/10.1530/joe-16-0495.

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Zebrafish are widely used as model organism. Their suitability for endocrine studies, drug screening and toxicity assessements depends on the extent of conservation of specific genes and biochemical pathways between zebrafish and human. Glucocorticoids consist of inactive 11-keto (cortisone and 11-dehydrocorticosterone) and active 11β-hydroxyl forms (cortisol and corticosterone). In mammals, two 11β-hydroxysteroid dehydrogenases (11β-HSD1 and 11β-HSD2) interconvert active and inactive glucocorticoids, allowing tissue-specific regulation of glucocorticoid action. Furthermore, 11β-HSDs are involved in the metabolism of 11-oxy androgens. As zebrafish and other teleost fish lack a direct homologue of 11β-HSD1, we investigated whether they can reduce 11-ketosteroids. We compared glucocorticoid and androgen metabolism between human and zebrafish using recombinant enzymes, microsomal preparations and zebrafish larvae. Our results provide strong evidence for the absence of 11-ketosteroid reduction in zebrafish. Neither human 11β-HSD3 nor the two zebrafish 11β-HSD3 homologues, previously hypothesized to reduce 11-ketosteroids, converted cortisone and 11-ketotestosterone (11KT) to their 11β-hydroxyl forms. Furthermore, zebrafish microsomes were unable to reduce 11-ketosteroids, and exposure of larvae to cortisone or the synthetic analogue prednisone did not affect glucocorticoid-dependent gene expression. Additionally, a dual-role of 11β-HSD2 by inactivating glucocorticoids and generating the main fish androgen 11KT was supported. Thus, due to the lack of 11-ketosteroid reduction, zebrafish and other teleost fish exhibit a limited tissue-specific regulation of glucocorticoid action, and their androgen production pathway is characterized by sustained 11KT production. These findings are of particular significance when using zebrafish as a model to study endocrine functions, stress responses and effects of pharmaceuticals.

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Husen, B., N. Psonka, M. Jacob-Meisel, C. Keil et GM Rune. « Differential expression of 17beta-hydroxysteroid dehydrogenases types 2 and 4 in human endometrial epithelial cell lines ». Journal of Molecular Endocrinology 24, n^o 1 (1 février 2000) : 135–44. http://dx.doi.org/10.1677/jme.0.0240135.

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In the endometrium two enzymes are known to convert estradiol to its inactive metabolite estrone: microsomal 17beta-hydroxysteroid dehydrogenase type 2 (17beta-HSD2) and peroxisomal 17beta-HSD4. In order to elucidate the particular function of each of these two different enzymes, the human endometrial epithelial cell lines HEC-1-A and RL95-2 were examined with respect to the expression of 17betaHSD isozymes. They were compared with human endometrium in vivo. Non-radioactive in situ hybridization revealed both enzymes in glandular epithelial cells of human endometrium. The two cell lines were screened for mRNA expression of 17beta-HSD 1-4 by RT-PCR and Northern blot. 17beta-HSD2 and 4 could be detected by either method, 17beta-HSD1 only by RT-PCR, 17beta-HSD3 not at all. Both cell lines were proven to have no receptor for progesterone which is known as a physiological inducer of several 17beta-HSD isozymes. To study the regulation of 17beta-HSD2 and 17betaHSD4, the concentration of fetal calf serum in the cell culture media was reduced stepwise to 0.3% by dilution with a defined serum replacement. This treatment led to an inhibition of 17beta-HSD2 mRNA expression and an increase in the mRNA expression of 17beta-HSD4. Concomitantly, distinct morphological changes were observed, such as a decrease in the number and length of microvilli and a decrease in the formation of domes on top of the monolayers. The endometrial epithelial cell lines HEC-1-A and RL95-2 represent a suitable in vitro model for further studies of the differential expression of the major endometrial HSD isozymes, independent of the effect of progesterone.

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Miro, P., M. L. Marin et M. A. Miranda. « Radical-mediated dehydrogenation of bile acids by means of hydrogen atom transfer to triplet carbonyls ». Organic & ; Biomolecular Chemistry 14, n^o 9 (2016) : 2679–83. http://dx.doi.org/10.1039/c5ob02561c.

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The aim of the present paper is to explore the potential of radical-mediated dehydrogenation of bile salts (BSs), which is reminiscent of the enzymatic action of hydroxysteroid dehydrogenase enzymes (HSDH).

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Zhou, L. Y., D. S. Wang, B. Senthilkumaran, M. Yoshikuni, Y. Shibata, T. Kobayashi, C. C. Sudhakumari et Y. Nagahama. « Cloning, expression and characterization of three types of 17β-hydroxysteroid dehydrogenases from the Nile tilapia, Oreochromis niloticus ». Journal of Molecular Endocrinology 35, n^o 1 (août 2005) : 103–16. http://dx.doi.org/10.1677/jme.1.01801.

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In order to elucidate the roles of 17β-HSDs in fish gonadal steroidogenesis, three types of 17β-HSDs (17β-HSD1, 17β-HSD8 and putative 17β-HSD12) were cloned and characterized from the Nile tilapia, Oreochromis niloticus. The cloned cDNAs of 17β-HSD type 1, 8 and 12 were 1504, 1006 and 1930 bp long, with open reading frames encoding proteins of 289, 256 and 314 aminoacids, respectively. Tissue distribution pattern analyzed by RT-PCR and Northern blot showed that 17β-HSD1 was dominantly expressed in the ovary, while the putative 17β-HSD12, one of the two duplicates found in fish, is a male specific enzyme and expressed exclusively in testis (detected by RT-PCR only). On the other hand, 17β-HSD8 was expressed in the brain, gill, heart, liver, intestine, gonad, kidney and muscle of both male and female. Enzymatic assays of the three types of 17β-HSDs were performed using recombinant proteins expressed in E. coli or HEK 293 cells. Tilapia 17β-HSD1 expressed in E. coli had the preference for NADP(H) as cofactor and could catalyze the inter-conversion between estrone and estradiol efficiently as well as the inter-conversion between androstenedione and testosterone, but less efficiently. Tilapia 17β-HSD8 recombinant protein expressed in HEK 293 cells could catalyze the conversion of testosterone to androstenedione, as well as the inter-conversion between estrone and estradiol. However, the putative 17β-HSD12 expressed in E. coli or in HEK 293 cells showed no conversion to any of the four substrates tested in this study. Based on enzyme characterization and tissue distribution, it is plausible to attribute crucial roles to 17β-HSDs in the gonadal steroidogenesis of teleosts.

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Miller, William G., Bruce M. Pearson, Jerry M. Wells, Craig T. Parker, Vladimir V. Kapitonov et Robert E. Mandrell. « Diversity within the Campylobacter jejuni type I restriction–modification loci ». Microbiology 151, n^o 2 (1 février 2005) : 337–51. http://dx.doi.org/10.1099/mic.0.27327-0.

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The type I restriction–modification (hsd) systems of 73 Campylobacter jejuni strains were characterized according to their DNA and amino acid sequences, and/or gene organization. A number of new genes were identified which are not present in the sequenced strain NCTC 11168. The closely related organism Helicobacter pylori has three type I systems; however, no evidence was found that C. jejuni strains contain multiple type I systems, although hsd loci are present in at least two different chromosomal locations. Also, unlike H. pylori, intervening ORFs are present, in some strains, between hsdR and hsdS and between hsdS and hsdM. No definitive function can be ascribed to these ORFs, designated here as rloA–H (R-linked ORF) and mloA–B (M-linked ORF). Based on parsimony analysis of amino acid sequences to assess character relatedness, the C. jejuni type I R–M systems are assigned to one of three families: ‘IAB’, ‘IC’ or ‘IF’. This study confirms that HsdM proteins within a family are highly conserved but share little homology with HsdM proteins from other families. The ‘IC’ hsd loci are >99 % identical at the nucleotide level, as are the ‘IF’ hsd loci. Additionally, whereas the nucleotide sequences of the ‘IAB’ hsdR and hsdM genes show a high degree of similarity, the nucleotide sequences of the ‘IAB’ hsdS and rlo genes vary considerably. This diversity suggests that recombination between ‘IAB’ hsd loci would lead not only to new hsdS alleles but also to the exchange of rlo genes; five C. jejuni hsd loci are presumably the result of such recombination. The importance of these findings with regard to the evolution of C. jejuni type I R–M systems is discussed.

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Huang, Xueting, Juanjuan Wang, Jing Li, Yanni Liu, Xue Liu, Zeyao Li, Kurni Kurniyati et al. « Prevalence of phase variable epigenetic invertons among host-associated bacteria ». Nucleic Acids Research 48, n^o 20 (29 octobre 2020) : 11468–85. http://dx.doi.org/10.1093/nar/gkaa907.

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Abstract Type I restriction-modification (R-M) systems consist of a DNA endonuclease (HsdR, HsdM and HsdS subunits) and methyltransferase (HsdM and HsdS subunits). The hsdS sequences flanked by inverted repeats (referred to as epigenetic invertons) in certain Type I R-M systems undergo invertase-catalyzed inversions. Previous studies in Streptococcus pneumoniae have shown that hsdS inversions within clonal populations produce subpopulations with profound differences in the methylome, cellular physiology and virulence. In this study, we bioinformatically identified six major clades of the tyrosine and serine family invertases homologs from 16 bacterial phyla, which potentially catalyze hsdS inversions in the epigenetic invertons. In particular, the epigenetic invertons are highly enriched in host-associated bacteria. We further verified hsdS inversions in the Type I R-M systems of four representative host-associated bacteria and found that each of the resultant hsdS allelic variants specifies methylation of a unique DNA sequence. In addition, transcriptome analysis revealed that hsdS allelic variations in Enterococcus faecalis exert significant impact on gene expression. These findings indicate that epigenetic switches driven by invertases in the epigenetic invertons broadly operate in the host-associated bacteria, which may broadly contribute to bacterial host adaptation and virulence beyond the role of the Type I R-M systems against phage infection.

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Trivedi, Seema, et Suresh Bihari Lall. « Histoarchitecture and Δ5-3β hydroxysteroid dehydrogenase profile in ovaries of the non-pregnant, pregnant and lactating insectivorous rat-tailed bat, Rhinopoma microphyllum kinneari ». Animal Biology 57, n^o 1 (2007) : 97–114. http://dx.doi.org/10.1163/157075607780001989.

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AbstractThe histoarchitecture and profile of Δ5-3β hydroxysteroid dehydrogenase were studied in an insectivorous seasonally-breeding microchiropteran, Rhinopoma microphyllum kinneari (rattailed bat) ovaries during non-pregnant, pregnant and lactation phases. Mid-sections of follicles and ova showed variation in their diameter (0.013-0.182 mm and 0.010-0.075 mm, respectively). Though dextral and sinistral ovaries are functionally equivalent, ovulation occurs only once (alternately from one ovary) in each annual cycle. An extroverted corpus luteum (0.792 mm) was observed in either the dextral or sinistral ovary of a pregnant R. m. kinneari. This exhibited two types of cells. Follicular atresia was pronounced in ovaries during these reproductive stages. No post-partum 'heat' was discerned. Δ5-3β HSDH is a crucial catalyst in steroid hormone biosynthesis and the reaction product indicates status of steroidogenesis in different follicle types. Differential Δ5-3β HSDH activity evident from reaction product staining in three reproductive states and in different ovarian components was seen. Consistent sites of enzyme activity were thecal cells and ovarian stroma. However, intensity varied in different reproductive states.

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Chapman, Karen, Megan Holmes et Jonathan Seckl. « 11β-Hydroxysteroid Dehydrogenases : Intracellular Gate-Keepers of Tissue Glucocorticoid Action ». Physiological Reviews 93, n^o 3 (juillet 2013) : 1139–206. http://dx.doi.org/10.1152/physrev.00020.2012.

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Glucocorticoid action on target tissues is determined by the density of “nuclear” receptors and intracellular metabolism by the two isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD) which catalyze interconversion of active cortisol and corticosterone with inert cortisone and 11-dehydrocorticosterone. 11β-HSD type 1, a predominant reductase in most intact cells, catalyzes the regeneration of active glucocorticoids, thus amplifying cellular action. 11β-HSD1 is widely expressed in liver, adipose tissue, muscle, pancreatic islets, adult brain, inflammatory cells, and gonads. 11β-HSD1 is selectively elevated in adipose tissue in obesity where it contributes to metabolic complications. Similarly, 11β-HSD1 is elevated in the ageing brain where it exacerbates glucocorticoid-associated cognitive decline. Deficiency or selective inhibition of 11β-HSD1 improves multiple metabolic syndrome parameters in rodent models and human clinical trials and similarly improves cognitive function with ageing. The efficacy of inhibitors in human therapy remains unclear. 11β-HSD2 is a high-affinity dehydrogenase that inactivates glucocorticoids. In the distal nephron, 11β-HSD2 ensures that only aldosterone is an agonist at mineralocorticoid receptors (MR). 11β-HSD2 inhibition or genetic deficiency causes apparent mineralocorticoid excess and hypertension due to inappropriate glucocorticoid activation of renal MR. The placenta and fetus also highly express 11β-HSD2 which, by inactivating glucocorticoids, prevents premature maturation of fetal tissues and consequent developmental “programming.” The role of 11β-HSD2 as a marker of programming is being explored. The 11β-HSDs thus illuminate the emerging biology of intracrine control, afford important insights into human pathogenesis, and offer new tissue-restricted therapeutic avenues.

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Huynh Thi Yen, Ly, Suk-Youl Park et Jeong-Sun Kim. « Cloning, crystallization and preliminary X-ray diffraction analysis of an intact DNA methyltransferase of a type I restriction–modification enzyme fromVibrio vulnificus ». Acta Crystallographica Section F Structural Biology Communications 70, n^o 4 (25 mars 2014) : 489–92. http://dx.doi.org/10.1107/s2053230x14004543.

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Independently of the restriction (HsdR) subunit, the specificity (HsdS) and methylation (HsdM) subunits interact with each other, and function as a methyltransferase in type I restriction–modification systems. A single gene that combines the HsdS and HsdM subunits inVibrio vulnificusYJ016 was expressed and purified. A crystal suitable for X-ray diffraction was obtained from 25%(w/v) polyethylene glycol monomethylether 5000, 0.1 MHEPES pH 8.0, 0.2 Mammonium sulfate at 291 K by hanging-drop vapour diffusion. Diffraction data were collected to a resolution of 2.31 Å using synchrotron radiation. The crystal belonged to the primitive monoclinic space groupP21, with unit-cell parametersa= 93.25,b= 133.04,c= 121.49 Å, β = 109.7°. With four molecules in the asymmetric unit, the crystal volume per unit protein weight was 2.61 Å3 Da−1, corresponding to a solvent content of 53%.

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Klemme, Jobst-Heinrich, Gisela Laakmann-Ditges et Jutta Mertschuweit. « Cellular Amino Acid Concentrations and Regulation of Aspartate Kinase in the Thermophilic Phototrophic Prokaryote Chloroflexus aurantiacus ». Zeitschrift für Naturforschung C 45, n^o 1-2 (1 février 1990) : 74–78. http://dx.doi.org/10.1515/znc-1990-1-213.

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Aspartate kinase (AK , EC 2.7.2.4) from the thermophilic, phototrophic prokaryote, Chloroflexus aurantiacus, was partially purified and separated from homoserine dehydrogenase (HSDH, EC 1.1.1.3). The molecular weights as determined by gel filtration were 130,000 and 46,000, respectively. HSDH had a moderately high thermal stability (50% inactivation at 84 °C) and displayed its activity optimum at 72 °C. By contrast, AK had its activity optimum at 52 °C (with a break-point in the Arrhenius plot at 42 °C) and was much less thermostable (50% inactivation at 67 °C). The Km-values for aspartate and ATP (determined in a pyruvate kinase-coupled test system) were 10.5 and 0.63 mM , respectively. The enzyme was strongly inhibited by L-threonine (Ki = 10 μm) and activated by alanine, isoleucine, valine and methionine. L-Threonine acted as a mixed-type inhibitor in respect to aspartate, and non-competitively in respect to ATP. Contrary to AKs from Rhodospirillaceae, the enzyme from Chloroflexus aurantiacus was not subject to a concerted feedback inhibition by two amino acids of the aspartate family. The regulatory properties of the aspartate kinase are discussed in relation to the cellular amino acid concentrations.

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Zhao, Fangqing, Xiaowen Zhang, Chengwei Liang, Jinyu Wu, Qiyu Bao et Song Qin. « Genome-wide analysis of restriction-modification system in unicellular and filamentous cyanobacteria ». Physiological Genomics 24, n^o 3 (mars 2006) : 181–90. http://dx.doi.org/10.1152/physiolgenomics.00255.2005.

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Cyanobacteria are an ancient group of gram-negative bacteria with strong genome size variation ranging from 1.6 to 9.1 Mb. Here, we first retrieved all the putative restriction-modification (RM) genes in the draft genome of Spirulina and then performed a range of comparative and bioinformatic analyses on RM genes from unicellular and filamentous cyanobacterial genomes. We have identified 6 gene clusters containing putative Type I RMs and 11 putative Type II RMs or the solitary methyltransferases (MTases). RT-PCR analysis reveals that 6 of 18 MTases are not expressed in Spirulina, whereas one hsdM gene, with a mutated cognate hsdS, was detected to be expressed. Our results indicate that the number of RM genes in filamentous cyanobacteria is significantly higher than in unicellular species, and this expansion of RM systems in filamentous cyanobacteria may be related to their wide range of ecological tolerance. Furthermore, a coevolutionary pattern is found between hsdM and hsdR, with a large number of site pairs positively or negatively correlated, indicating the functional importance of these pairing interactions between their tertiary structures. No evidence for positive selection is found for the majority of RMs, e.g., hsdM, hsdS, hsdR, and Type II restriction endonuclease gene families, while a group of MTases exhibit a remarkable signature of adaptive evolution. Sites and genes identified here to have been under positive selection would provide targets for further research on their structural and functional evaluations.

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Mericq, V., P. Medina, E. Kakarieka, L. Márquez, M. C. Johnson et G. Iñiguez. « Differences in expression and activity of 11β-hydroxysteroid dehydrogenase type 1 and 2 in human placentas of term pregnancies according to birth weight and gender ». European Journal of Endocrinology 161, n^o 3 (septembre 2009) : 419–25. http://dx.doi.org/10.1530/eje-09-0308.

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BackgroundFetal exposure to maternal glucocorticoids may determine fetal growth and the programing of later disorders. Availability of the glucocorticoids in the placenta is regulated by the 11β-hydroxysteroid dehydrogenase (11β-HSDs) enzymes. To date, there are discrepancies with regard to cortisol (F) cord blood levels in fetuses with intrauterine growth retardation in different species.ObjectiveTo study the expression and activity of 11β-HSDs in placentas from full term small for gestational age (SGA), appropriate for gestational age (AGA) and large for gestational age (LGA) newborns, and cortisol cord blood concentration.MethodsTwenty-five placentas from AGA, 24 SGA and 25 LGA were collected.ResultsSGA newborns had significantly lower and LGA newborns had significantly higher birth weight, birth length, head circumference, and placental weight than AGA counterparts. We observed a direct correlation between placental weight and birth weight, birth length and head circumference, and higher cord F levels in SGA newborns. The 11β-HSD1 expression was similar among the SGA, AGA, and LGA placentas. However, within the placentas of SGA newborns, the11β-HSD1mRNA levels were significantly reduced in the chorionic plate compared with basal plate. An inverse correlation between cord F levels and activity of 11β-HSD1 in the chorionic plate of the SGA placentas was detected. The 11β-HSD2 activity was seven- to eightfold higher compared with 11β-HSD1 in the placentas, and there was a lower 11β-HSD2 activity in females' SGA placentas compared with the male SGA placentas.ConclusionWe observed a lower expression and activity of 11β-HSD1 in the chorionic plate of the SGA placentas, suggesting a possible compensatory mechanism to diminish the higher cortisol fetal concentrations observed in fetuses with intrauterine growth restriction.

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Bialevich, Vitali, Dhiraj Sinha, Katsiaryna Shamayeva, Alena Guzanova, David Řeha, Eva Csefalvay, Jannette Carey, Marie Weiserova et Rüdiger H. Ettrich. « The helical domain of the EcoR124I motor subunit participates in ATPase activity and dsDNA translocation ». PeerJ 5 (18 janvier 2017) : e2887. http://dx.doi.org/10.7717/peerj.2887.

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Type I restriction-modification enzymes are multisubunit, multifunctional molecular machines that recognize specific DNA target sequences, and their multisubunit organization underlies their multifunctionality. EcoR124I is the archetype of Type I restriction-modification family IC and is composed of three subunit types: HsdS, HsdM, and HsdR. DNA cleavage and ATP-dependent DNA translocation activities are housed in the distinct domains of the endonuclease/motor subunit HsdR. Because the multiple functions are integrated in this large subunit of 1,038 residues, a large number of interdomain contacts might be expected. The crystal structure of EcoR124I HsdR reveals a surprisingly sparse number of contacts between helicase domain 2 and the C-terminal helical domain that is thought to be involved in assembly with HsdM. Only two potential hydrogen-bonding contacts are found in a very small contact region. In the present work, the relevance of these two potential hydrogen-bonding interactions for the multiple activities of EcoR124I is evaluated by analysing mutant enzymes usingin vivoandin vitroexperiments. Molecular dynamics simulations are employed to provide structural interpretation of the functional data. The results indicate that the helical C-terminal domain is involved in the DNA translocation, cleavage, and ATPase activities of HsdR, and a role in controlling those activities is suggested.

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Grinkevich, Pavel, Iuliia Iermak, Nicholas A. Luedtke, Jeroen R. Mesters, Rüdiger Ettrich et Jost Ludwig. « pHluorin-assisted expression, purification, crystallization and X-ray diffraction data analysis of the C-terminal domain of the HsdR subunit of theEscherichia colitype I restriction-modification system EcoR124I ». Acta Crystallographica Section F Structural Biology Communications 72, n^o 9 (9 août 2016) : 672–76. http://dx.doi.org/10.1107/s2053230x16011626.

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The HsdR subunit of the type I restriction-modification system EcoR124I is responsible for the translocation as well as the restriction activity of the whole complex consisting of the HsdR, HsdM and HsdS subunits, and while crystal structures are available for the wild type and several mutants, the C-terminal domain comprising approximately 150 residues was not resolved in any of these structures. Here, three fusion constructs with the GFP variant pHluorin developed to overexpress, purify and crystallize the C-terminal domain of HsdR are reported. The shortest of the three encompassed HsdR residues 887–1038 and yielded crystals that belonged to the orthorhombic space groupC2221, with unit-cell parametersa= 83.42,b= 176.58,c= 126.03 Å, α = β = γ = 90.00° and two molecules in the asymmetric unit (VM= 2.55 Å3 Da−1, solvent content 50.47%). X-ray diffraction data were collected to a resolution of 2.45 Å.

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Devendran, Saravanan, Sean M. Mythen et Jason M. Ridlon. « The desA and desB genes from Clostridium scindens ATCC 35704 encode steroid-17,20-desmolase ». Journal of Lipid Research 59, n^o 6 (23 mars 2018) : 1005–14. http://dx.doi.org/10.1194/jlr.m083949.

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Clostridium scindens is a gut microbe capable of removing the side-chain of cortisol, forming 11β-hydroxyandrostenedione. A cortisol-inducible operon (desABCD) was previously identified in C. scindens ATCC 35704 by RNA-Seq. The desC gene was shown to encode a cortisol 20α-hydroxysteroid dehydrogenase (20α-HSDH). The desD encodes a protein annotated as a member of the major facilitator family, predicted to function as a cortisol transporter. The desA and desB genes are annotated as N-terminal and C-terminal transketolases, respectively. We hypothesized that the DesAB forms a complex and has steroid-17,20-desmolase activity. We cloned the desA and desB genes from C. scindens ATCC 35704 in pETDuet for overexpression in Escherichia coli. The purified recombinant DesAB was determined to be a 142 ± 5.4 kDa heterotetramer. We developed an enzyme-linked continuous spectrophotometric assay to quantify steroid-17,20-desmolase. This was achieved by coupling DesAB-dependent formation of 11β-hydroxyandrostenedione with the NADPH-dependent reduction of the steroid 17-keto group by a recombinant 17β-HSDH from the filamentous fungus, Cochliobolus lunatus. The pH optimum for the coupled assay was 7.0 and kinetic constants using cortisol as substrate were Km of 4.96 ± 0.57 µM and kcat of 0.87 ± 0.076 min−1. Substrate-specificity studies revealed that rDesAB recognized substrates regardless of 11β-hydroxylation, but had an absolute requirement for 17,21-dihydroxy 20-ketosteroids.

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Shimojo, M., C. B. Whorwood et P. M. Stewart. « 11β-Hydroxysteroid dehydrogenase in the rat adrenal ». Journal of Molecular Endocrinology 17, n^o 2 (octobre 1996) : 121–30. http://dx.doi.org/10.1677/jme.0.0170121.

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ABSTRACT 11β-Hydroxysteroid dehydrogenase (11β-HSD) catalyses the interconversion of biologically active cortisol to inactive cortisone in man, and corticosterone to 11-dehydrocorticosterone in rodents. As such, this enzyme has been shown to confer aldosterone-selectivity on the mineralocorticoid receptor and to modulate cortisol/corticosterone access to the glucocorticoid receptor (GR). Two kinetically distinct isoforms of this enzyme have been characterized in both rodents and man; a low-affinity NADP(H)-dependent enzyme (11β-HSD1) which predominantly acts as an oxo-reductase and, more recently, a high-affinity NAD-dependent uni-directional dehydrogenase (11β-HSD2). In this study we have analysed the expression of both 11β-HSD1 and 11β-HSD2 isoforms in rat adrenal cortex and medulla and have investigated their possible roles with respect to glucocorticoid-regulated enzymes mediating catecholamine biosynthesis in adrenal medullary chromaffin cells. Using a rat 11β-HSD1 probe and a recently cloned in-house mouse 11β-HSD2 cDNA probe, Northern blot analyses revealed expression of mRNA species encoding both 11β-HSD1 (1·4kb) and 11β-HSD2 (1·9kb) in the whole adrenal. Consistent with this, 11β-dehydrogenase activity (pmol 11-dehydrocorticosterone formed/mg protein per h, mean ± s.e.m.) in adrenal homogenates, when incubated with 50 nm corticosterone in the presence of 200 μm NAD, was 97·0 ± 9·0 and with 500 nm corticosterone in the presence of 200 μm NADP, was 98·0 ± 1·4 11-Oxoreductase activity (pmol corticosterone formed/mg protein per h) with 500 nm 11-dehydrocorticosterone in the presence of 200 μm NADPH, was 187·7 ± 31·2. In situ hybridization studies of rat adrenal cortex and medulla using 35S-labelled antisense 11β-HSD1 cRNA probe revealed specific localization of 11β-HSD1 mRNA expression predominantly to cells at the corticomedullary junction, most likely within the inner cortex. In contrast, 11β-HSD2 mRNA was more abundant in cortex versus medulla, and was more uniformly distributed over the adrenal gland. Negligible staining was detected using control sense probes. Ingestion of the 11β-HSD inhibitor, glycyrrhizic acid (>100mg/kg body weight per day for 4 days) resulted in significant inhibition of adrenal NADP-dependent (98·0 ± 1·4 vs 42·5 ± 0·4) and NAD-dependent (97·0 ± 9·0 vs 73·2 ± 6·7) 11β-dehydrogenase activity and 11-oxoreductase activity (187·7 ± 31·2 vs 67·7 ± 15·3). However, while levels of 11β-HSD1 mRNA were similarly reduced (0·85 ± 0·07 vs 0·50 ± 0·05 arbitrary units), those for 11β-HSD2 remained unchanged (0·44 ± 0·03 vs 0·38 ± 0·01). Levels of mRNA encoding the glucocorticoid-dependent enzyme phenylethanolamine N-methyltransferase which catalyses the conversion of noradrenaline to adrenaline, were also significantly reduced in those rats given glycyrrhizic acid (1·12 ± 0·04 vs 0·78 ± 0·04), while those for the glucocorticoid-independent enzyme tyrosine hydroxylase (1·9 kb), which catalyses the conversion of tyrosine to DOPA, were unchanged (0·64 ± 0·04 vs 0·61 ± 0·04). In conclusion, the rat adrenal gland expresses both 11β-HSD1 and 11β-HSD2 isoforms. 11β-HSDl gene expression is localized to the adrenal cortico-medullary junction, where it is ideally placed to regulate the supply of cortex-derived corticosterone to the medullary chromaffin cells. This, together with our in vivo studies, suggests that 11β-HSD1 may play an important role with respect to adrenocorticosteroid regulation of adrenaline biosynthesis. The role of 11β-HSD2 in the adrenal remains to be elucidated.

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Baumgartner, Maximilian, Michaela Lang, Marion Nehr, Petra Pjevac, Bela Hausmann, Rasmus H. Kirkegaard, Anton Klotz et al. « 406 : RUMINOCOCCUS GNAVUS 3β-HSDH LINKS MUCOSAL BIOFILMS AND BILE ACID MALABSORPTION ». Gastroenterology 162, n^o 7 (mai 2022) : S—90. http://dx.doi.org/10.1016/s0016-5085(22)60227-0.

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Tetsi Nomigni, Milène, Sophie Ouzounian, Alice Benoit, Jacqueline Vadrot, Frédérique Tissier, Sylvie Renouf, Hervé Lefebvre, Sophie Christin-Maitre et Estelle Louiset. « Steroidogenic enzyme profile in an androgen-secreting adrenocortical oncocytoma associated with hirsustism ». Endocrine Connections 4, n^o 2 (juin 2015) : 117–27. http://dx.doi.org/10.1530/ec-15-0014.

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Hirsutism induced by hyperandrogenism can be associated with polycystic ovary syndrome, 21-hydroxylase (OH) deficiency or androgen-secreting tumors, including ovarian and adrenal tumors. Adrenal androgen-secreting tumors are frequently malignant. Adrenal oncocytomas represent rare causes of hyperandrogenism. The aim of the study was to investigate steroidogenic enzyme expression and steroid secretion in an androgen-secreting adrenal oncocytoma in a young woman presenting with hirsutism. Hyperandrogenism was diagnosed on the basis of elevated plasma Δ4-androstenedione and testosterone levels. Pelvic ultrasound was normal, CT scanning revealed a right adrenal mass. Androgens were assessed in adrenal and ovarian vein samples and proved a right adrenal origin. Adrenalectomy normalized androgen levels and the adrenal tumor was diagnosed as an oncocytoma. Real time-PCR, immunohistochemistry and cell culture studies were performed on tumor explants to investigate the steroid secretion profile. Among enzymes required for cortisol synthesis, 17α-OH and 3β-hydroxysteroid dehydrogenase 2 (3β-HSD2) were highly expressed whereas 21-OH and 11β-OH were weakly produced at the mRNA and/or protein levels. Enzymes involved in testosterone production, 17β-HSD5 and 17β-HSD3, were also detected. ACTH receptor was present in the tissue. Cortisol, Δ4-androstenedione and testosterone secretions by cultured cells were increased by ACTH. These results provide the first demonstration, to our knowledge, of abnormal expression profile of steroidogenic enzymes in an adrenocortical oncocytoma. Our results also indicate that Δ4-androstenedione hypersecretion resulted from high 17α-OH and 3β-HSD2 expression in combination with low expression of 21-OH and 11β-OH. Testosterone production was ascribed to occurrence of 17β-HSD5 and 17β-HSD3. Finally, our results indicate that androgen secretion was stimulated by ACTH.

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Legeza, Balázs, Zoltán Balázs, Lyubomir G. Nashev et Alex Odermatt. « The Microsomal Enzyme 17β-Hydroxysteroid Dehydrogenase 3 Faces the Cytoplasm and Uses NADPH Generated by Glucose-6-Phosphate Dehydrogenase ». Endocrinology 154, n^o 1 (1 janvier 2013) : 205–13. http://dx.doi.org/10.1210/en.2012-1778.

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Recent studies proposed a functional coupling between 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3)-dependent testosterone formation and 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1)-mediated interconversion of glucocorticoids through competition for the luminal pyridine nucleotide pool. To test this hypothesis, we used human embryonic kidney-293 cells transfected with 17β-HSD3 and/or 11β-HSD1, in the absence or presence of hexose-6-phosphate dehydrogenase that generates reduced nicotinamide adenine dinucleotide phosphate (NADPH) in the endoplasmic reticulum and determined enzyme activities. As an endogenous cell model, mouse MA-10 Leydig cells were used. 17β-HSD3-dependent reduction of Δ4-androstene-3,17-dione was affected by neither coexpression with 11β-HSD1 nor overexpression or knockdown of hexose-6-phosphate dehydrogenase. In contrast, knockdown of glucose-6-phosphate dehydrogenase decreased 17β-HSD3 activity, indicating dependence on cytoplasmic NADPH. Upon selective permeabilization of the plasma membrane by digitonin, 17β-HSD3 but not 11β-HSD1 was detected by antibodies against C-terminal epitope tags, suggesting a cytoplasmic orientation of 17β-HSD3. The cytoplasmic orientation was confirmed using proteinase K digestion of microsomal preparations and by analysis of glycosylation of wild-type 17β-HSD3 and chimera in which the N-terminal anchor sequences between 17β-HSD3 and 11β-HSD1 were exchanged. In conclusion, the results demonstrate a cytoplasmic orientation of 17β-HSD3 and dependence on glucose-6-phosphate dehydrogenase-generated NADPH, explaining the lack of a direct functional coupling with the luminal 11β-HSD1-mediated glucocorticoid metabolism.

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Jang, Christina, Varuni R. Obeyesekere, Rodney J. Dilley, Zygmunt Krozowski, Warrick J. Inder et Frank P. Alford. « Altered Activity of 11β-Hydroxysteroid Dehydrogenase Types 1 and 2 in Skeletal Muscle Confers Metabolic Protection in Subjects with Type 2 Diabetes ». Journal of Clinical Endocrinology & ; Metabolism 92, n^o 8 (1 août 2007) : 3314–20. http://dx.doi.org/10.1210/jc.2006-2729.

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Abstract Context: There is little information regarding the regulation of 11β-hydroxysteroid dehydrogenase (11β-HSD) enzymes in skeletal muscle in the setting of type 2 diabetes. Objective: Our objective was to investigate whether there is differential mRNA expression and enzyme activity of 11β-HSD1 and 11β-HSD2 in the skeletal muscle of diabetic subjects compared with controls at baseline and in response to dexamethasone. Design: Participants underwent muscle biopsy of vastus lateralis at baseline and after dexamethasone. Setting: The study took place at a university teaching hospital. Participants: Twelve subjects with type 2 diabetes and 12 age- and sex-matched controls participated. Intervention: Subjects were given oral dexamethasone, 4 mg/d for 4 d. Main Outcome Measures: We assessed 11β-HSD1, 11β-HSD2, and H6PDH mRNA levels by quantitative RT-PCR and enzyme activity by percent conversion of [3H]cortisone and [3H]cortisol, respectively. Results: At baseline, mRNA levels were similar in diabetic and control subjects for 11β-HSD1, 11β-HSD2, and H6PDH. 11β-HSD1 activity was reduced in diabetic subjects (percent conversion of [3H]cortisone to [3H]cortisol was 11.4 ± 2.5% vs. 18.5 ± 2.2%; P = 0.041), and 11β-HSD2 enzyme activity was higher in diabetic subjects (percent conversion of [3H]cortisone to [3H]cortisol was 17.2 ± 2.6% vs. 9.2 ± 1.3%; P = 0.012). After dexamethasone, 11β-HSD1 mRNA increased in both groups (P < 0.001), whereas 11β-HSD2 mRNA decreased (P = 0.002). 11β-HSD1 activity increased in diabetic subjects (P = 0.021) but not in controls, whereas 11β-HSD2 activity did not change in either group. At baseline, there was a significant negative correlation between 11β-HSD1 and 11β-HSD2 enzyme activity (r = −0.463; P = 0.026). Conclusions: The activities of skeletal muscle 11β-HSD1 and 11β-HSD2 are altered in diabetes, which together may reduce intracellular cortisol generation, potentially conferring metabolic protection.

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Oliver, Melissa B., et W. Edward Swords. « Comparative Analysis of Streptococcus pneumoniae Type I Restriction-Modification Loci : Variation in hsdS Gene Target Recognition Domains ». Pathogens 9, n^o 9 (29 août 2020) : 712. http://dx.doi.org/10.3390/pathogens9090712.

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Streptococcus pneumoniae (pneumococcus) is a respiratory commensal pathogen that causes a range of infections, particularly in young children and the elderly. Pneumococci undergo spontaneous phase variation in colony opacity phenotype, in which DNA rearrangements within the Type I restriction-modification (R-M) system specificity gene hsdS can potentially generate up to six different hsdS alleles with differential DNA methylation activity, resulting in changes in gene expression. To gain a broader perspective of this system, we performed bioinformatic analyses of Type I R-M loci from 18 published pneumococcal genomes, and one R-M locus sequenced for this study, to compare genetic content, organization, and homology. All 19 loci encoded the genes hsdR, hsdM, hsdS, and at least one hsdS pseudogene, but differed in gene order, gene orientation, and hsdS target recognition domain (TRD) content. We determined the coding sequences of 87 hsdS TRDs and excluded seven from further analysis due to the presence of premature stop codons. Comparative analyses revealed that the TRD 1.1, 1.2, and 2.1 protein sequences had single amino acid substitutions, and TRD 2.2 and 2.3 each had seven differences. The results of this study indicate that variability exists among the gene content and arrangements within Type I R-M loci may provide an additional level of divergence between pneumococcal strains, such that phase variation-mediated control of virulence factors may vary significantly between individual strains. These findings are consistent with presently available transcript profile data.

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Taketo-Hosotani, T., Y. Nishioka, C. M. Nagamine, I. Villalpando et H. Merchant-Larios. « Development and fertility of ovaries in the B6.YDOM sex-reversed female mouse ». Development 107, n^o 1 (1 septembre 1989) : 95–105. http://dx.doi.org/10.1242/dev.107.1.95.

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When the Y chromosome of Mus musculus domesticus (YDOM) was introduced onto the C57BL/6 (B6) mouse background, half of the XY progeny (B6.YDOM) developed bilateral ovaries and female internal and external genitalia. We examined the fertility of the B6.YDOM sex-reversed female mouse. The chromosomal sex of the individual mouse was identified by dot hybridization with mouse Y chromosome-specific DNA probes. The results indicated that all XY females lacked regular estrous cyclicity although most were able to mate and ovulate after treatment with gonadotropins. When they had been ovariectomized and grafted with ovaries from the XX female litter mate, they initiated estrous cyclicity. Reciprocally, the XX female that had received XY ovarian grafts did not resume estrous cyclicity. Development of the XY ovary was morphologically comparable to the XX ovary until 16 day of gestation (d.g.), when most germ cells had reached the zygotene or pachytene stage of meiotic prophase. However, by the day of delivery (19 or 20 d.g.), no oocyte remained in the medullary cords of the XY ovary. In the control XX ovary, the first generation of follicles developed in the medullary region, and 5 delta-3 beta-hydroxysteroid dehydrogenase (3 beta-HSDH) activity appeared first in the stromal cells around growing follicles by 10 days after birth. In contrast, in the XY ovary, follicles were not formed in the medullary region, and 3 beta-HSDH activity appeared in epithelial cells of the oocyte-free medullary cords. Primordial follicles in the cortex region continued development in both the XX and XY ovaries. These results suggest that the XY female is infertile due to a defect inside the XY ovary. The prenatal loss of oocytes in the medullary cords may be a key event leading to abnormal endocrine function, and thereby, the absence of estrous cyclicity.

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Prabha, Vijay, Meenakshi Gupta, D. Seiffge et K. G. Gupta. « Purification of 7α-hydroxysteroid dehydrogenase from Escherichia coli strain 080 ». Canadian Journal of Microbiology 36, n^o 2 (1 février 1990) : 131–35. http://dx.doi.org/10.1139/m90-023.

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Purification studies of 7α-hydroxysteroid dehydrogenase (7α-HSDH) (EC 1.1.1.159) from Escherichia coli 080 showed that 1.59-fold purification could be achieved by heating (60 °C for 10 min) the ultracentrifuged enzyme preparation, and 6.46-fold purification was achieved by subsequent precipitation with ammonium sulfate. Further purification on Sephadex G-100 gel gave 10.1-fold purification. After pooling and concentrating the active fractions obtained from the Sephadex G-100 filtration, an 11.1-fold purification was achieved using DEAE-cellulose chromatography. The purified enzyme produced a single band on polyacrylamide gel electrophoresis and its molecular weight was determined to be 54 000. The enzyme was immunogenic and showed immunoprecipitation with homologus antisera. Key words: 7α-hydroxysteroid dehydrogenase, Escherichia coli.

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Souness, Graham W., Andrew S. Brem et David J. Morris. « Antisense to Both 11β-Hsd1 and 2 Increase Glucocorticoid (GC) Activity in Vascular Tissue ». Hypertension 36, suppl_1 (octobre 2000) : 705. http://dx.doi.org/10.1161/hyp.36.suppl_1.705-c.

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P69 GC’s amplify the pressor effects of catecholamines and Ang II in VSM. Thus, the level of vasoconstriction in vascular tissue can be influenced by local GC concentrations. GC’s are metabolized to their inactive 11-dehydro derivatives by the enzyme 11β-HSD which exists in at least two isoforms, 11β-HSD1 and 11β-HSD2. 11β-HSD2 is unidirectional, with only dehydrogenase activity (inactivating GC’s) while 11β-HSD1 is bi-directional, also possessing reductase activity and thus the ability to reactivate 11-dehydroGC’s back to the active parent steroid. The aim of the present study was to investigate the role of each isoform in the regulation of GC metabolism in vascular tissue. Aortic rings (2-3mm), from male SD rats, were incubated for 24 hrs in DMEM media with either corticosterone (B) or 11-dehydrocorticosterone (11-dehydroB)(10 -8 -10 -7 M) ± specific Antisense oligos (20 μg/ring) targeted against rat 11β-HSD1 or 11β-HSD2. The contractile responses to graded doses of phenylephrine (PE; 10 -9 - 10 -6 M)in individual rings were then measured. In aortic rings co-incubated with B and 11β-HSD2 Antisense, the contractile responses to PE were amplified 30-50% versus rings incubated with B + nonsense oligonicleotide (n = 21, p < 0.01). The co-incubation of aortic rings with B + 11β-HSD1 Antisense resulted in a 50% increase in the contractile responses to PE (n = 8, p<0.001). In parallel experiments, 11β-HSD2 Antisense caused a 25% reduction(n =16 aortic rings) and 11β-HSD1 Antisense a 12% reduction (n = 8 aortic rings)in the metabolism of B to 11-dehydroB. These results indicate that 11β-HSD1 and 11β-HSD2 are both important in the metabolism of GC’s in vascular tissue and hence in the regulation of vascular tone. Additionally, rat aortic rings incubated with 11-dehydroB have an increased contractile response to PE versus controls, an effect attenuated by 11β-HSD1 Antisense. This suggests 11-dehydroB is re-activated back to B by 11β-HSD1-reductase making this enzyme a target for possible antihypertensive therapies.

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Lou, Deshuai, Xiaoli Zhang, Yangyang Cao, Zixin Zhou, Cheng Liu, Gang Kuang, Jun Tan et Liancai Zhu. « A novel NADP(H)-dependent 3α-HSDH from the intestinal microbiome of Ursus thibetanus ». International Journal of Biological Macromolecules 219 (octobre 2022) : 159–65. http://dx.doi.org/10.1016/j.ijbiomac.2022.07.252.

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Devendran, Saravanan, Celia Méndez-García et Jason M. Ridlon. « Identification and characterization of a 20β-HSDH from the anaerobic gut bacteriumButyricicoccus desmolansATCC 43058 ». Journal of Lipid Research 58, n^o 5 (17 mars 2017) : 916–25. http://dx.doi.org/10.1194/jlr.m074914.

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Coutinho, Agnes E., Mohini Gray, David G. Brownstein, Donald M. Salter, Deborah A. Sawatzky, Spike Clay, James S. Gilmour, Jonathan R. Seckl, John S. Savill et Karen E. Chapman. « 11β-Hydroxysteroid Dehydrogenase Type 1, But Not Type 2, Deficiency Worsens Acute Inflammation and Experimental Arthritis in Mice ». Endocrinology 153, n^o 1 (1 janvier 2012) : 234–40. http://dx.doi.org/10.1210/en.2011-1398.

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Glucocorticoids profoundly influence immune responses, and synthetic glucocorticoids are widely used clinically for their potent antiinflammatory effects. Endogenous glucocorticoid action is modulated by the two isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD). In vivo, 11β-HSD1 catalyzes the reduction of inactive cortisone or 11-dehydrocorticosterone into active cortisol or corticosterone, respectively, thereby increasing intracellular glucocorticoid levels. 11β-HSD2 catalyzes the reverse reaction, inactivating intracellular glucocorticoids. Both enzymes have been postulated to modulate inflammatory responses. In the K/BxN serum transfer model of arthritis, 11β-HSD1-deficient mice showed earlier onset and slower resolution of inflammation than wild-type controls, with greater exostoses in periarticular bone and, uniquely, ganglion cysts, consistent with greater inflammation. In contrast, K/BxN serum arthritis was unaffected by 11β-HSD2 deficiency. In a distinct model of inflammation, thioglycollate-induced sterile peritonitis, 11β-HSD1-deficient mice had more inflammatory cells in the peritoneum, but again 11β-HSD2-deficient mice did not differ from controls. Additionally, compared with control mice, 11β-HSD1-deficient mice showed greater numbers of inflammatory cells in pleural lavages in carrageenan-induced pleurisy with lung pathology consistent with slower resolution. These data suggest that 11β-HSD1 limits acute inflammation. In contrast, 11β-HSD2 plays no role in acute inflammatory responses in mice. Regulation of local 11β-HSD1 expression and/or delivery of substrate may afford a novel approach for antiinflammatory therapy.

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Tseng, J. K., P. C. Tang et J. C. Ju. « 357 CALCIUM RELEASE INDUCED BY THIMEROSAL AND INOSITOL 1,4,5-TRIPHOSPHATE IN HEAT-SHOCKED PORCINE OOCYTES ». Reproduction, Fertility and Development 19, n^o 1 (2007) : 294. http://dx.doi.org/10.1071/rdv19n1ab357.

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Elevated ambient temperature has been known to be deleterious to the developmental competence of mammalian oocytes and embryos, although the mechanism is still unclear. The objective of this study was to determine the effect of heat shock (HS) on the alteration of intracellular calcium concentrations ([Ca2+]i) of matured pig oocytes by two different calcium releasing agents. Porcine cumulus–oocyte complexes were aspirated from the follicles (3–6 mm) and subjected to standard in vitro maturation procedure for 42 h. Matured oocytes were then randomly allocated to different heat treatments at 41.5°C for 0 (Control, C0h), 1 (HS1h), 2 (HS2h), or 4 h (HS4h). An additional control group was cultured for 4 h without heat shock (C4h). Oocytes were incubated with 2 µM fura-2 acetoxymethyl ester (AM) and 0.02% pluronic F-127 in Ca2+-free PBS (40 min) following heat shock, and then washed with Ca2+-free PBS (30 min) for detection of [Ca2+]i. Fluorescent images were captured with alternative excitation wavelengths at 340/380 nm by a rotating chopper disk equipped with an Axon imaging system. Data from both experiments were analyzed by ANOVA using the General Linear Model (GLM) of the SAS (SAS Institute, Inc., Cary, NC, USA). In Experiment 1, matured oocytes were activated by 200 mM thimerosal (10 min) following heat treatment. The maximal [Ca2+]i in the HS2h group was the highest among all treatment groups. The lowest maximal peak of [Ca2+]i was observed in the HS4h group, but it was still higher than that in the C4h group (P < 0.05). The total amount of Ca2+ release represented by the total area of the peaks in C4h was lower than in any other groups except HS4h (P < 0.05). In Experiment 2, each matured oocyte was injected with approximately 10 pL of inositol 1,4,5-triphosphate (IP3, 0.5 mM); the Ca2+ transient was recorded as described in the previous experiment. The maximal value of [Ca2+]i in the C4h group was still the lowest among the heat-shocked and C0h groups (P < 0.05). The total Ca2+ release in the HS2h group was the highest among all treatment groups, but only significantly higher than the HS1h and C4h groups (P < 0.05). A similar pattern of Ca2+ release in HS-oocytes was induced by thimerosal and IP3 stimulations. These results indicate that Ca2+ releasing capacity of matured pig oocytes is enhanced by a shorter duration of heat shock, but declines after prolonged exposure of heat shock and/or in vitro culture. The differential Ca2+ releasing capacity of heat-shocked oocytes prior to fertilization revealed physiological changes of pig oocytes after heat shock. This finding provides further insight for the low fertilization and developmental competence that occurs in farm species during hot seasons.

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Langlois, D. A., S. G. Matthews, M. Yu et K. Yang. « Differential expression of 11β-hydroxysteroid dehydrogenase 1 and 2 in the developing ovine fetal liver and kidney ». Journal of Endocrinology 147, n^o 3 (décembre 1995) : 405–11. http://dx.doi.org/10.1677/joe.0.1470405.

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Abstract In adult mammals, liver and kidney are the two major sites of biosynthesis for 11β-hydroxysteroid dehydrogenase (11β-HSD) 1 and 2 respectively. In the present study, the expression of these two isozymes in the developing ovine fetal liver and kidney was characterized. Livers and kidneys were obtained from fetal sheep at days 85, 100–120 and 140–143 of gestation (term=145 days). Tissue levels of 11β-HSD2 mRNA were assessed by Northern blot analysis. 11β-HSD dehydrogenase and reductase activities in tissue homogenates were determined by a radiometric conversion assay using cortisol and cortisone as physiological substrates respectively. The unidirectional 11β-HSD2 dehydrogenase activity was identified by its distinct co-factor preference (NAD), and by its unique ability to metabolize dexamethasone (Dex). In the liver, 11β-HSD1 dehydrogenase and reductase activities were present by day 85, and their levels did not change between days 85 and 100–120 but increased more than twofold at days 140–143. This was consistent with changes we reported previously in the fetal hepatic 11β-HSD1 mRNA. 11β-HSD1 reductase activity was always higher than the dehydrogenase activity. 11β-HSD2 mRNA and activity were undetectable in the fetal liver at all three ages. By contrast, 11β-HSD2 mRNA was present in the fetal kidney by day 85, and its abundance increased progressively thereafter. There was a parallel increase in the renal 11β-HSD2 activity. Dex was also converted to 11-dehydro-Dex by the fetal kidney. In keeping with the absence of the full-length 11β-HSD1 mRNA, 11β-HSD1 activity was undetectable in the kidney. These results indicate that (1) 11β-HSD1 and 2 genes are differentially expressed and regulated in the fetal liver and kidney during development, (2) since the hepatic 11β-HSD1 reductase activity is always higher than the dehydrogenase activity, the fetal liver may be a potential extra-adrenal source of cortisol, and (3) 11β-HSD2 in the kidney may play a very important role in protecting the fetus from elevated levels of bioactive glucocorticoids. Journal of Endocrinology (1995) 147, 405–411

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Patel, Pushpa, Rowan Hardy, Vaiyapuri Sumathi, Gillian Bartle, Lars-Gunnar Kindblom, Robert Grimer, Iwona Bujalska et al. « Expression of 11β-hydroxysteroid dehydrogenase enzymes in human osteosarcoma : potential role in pathogenesis and as targets for treatments ». Endocrine-Related Cancer 19, n^o 4 (20 juin 2012) : 589–98. http://dx.doi.org/10.1530/erc-12-0079.

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Osteosarcoma (OS) is a primary malignant tumour of bone occurring predominantly in children and young adults. Despite chemotherapy, relapse is common and mortality remains high. Non-transformed osteoblasts are highly sensitive to glucocorticoids, which reduce proliferation and induce apoptosis. Previously, we observed that OS cells, but not normal osteoblasts, express 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2). This enzyme inactivates cortisol (active) to cortisone (inactive) and expression of 11β-HSD2 renders OS cells resistant to glucocorticoids. By contrast, the related enzyme 11β-HSD1 converts cortisone to cortisol and reduces OS cell proliferation in vitro. Some synthetic glucocorticoids (e.g. dehydrodexamethasone (DHD), inactive counterpart of dexamethasone (DEX)) have been reported to be activated by 11β-HSD2. We therefore investigated expression and enzymatic activity of 11β-HSD isozymes in human OS tissue, determined whether 11β-HSD expression has prognostic value in the response to therapy, and evaluated the potential use of synthetic glucocorticoids to selectively target OS cells. OS samples expressed both 11β-HSD1 and 11β-HSD2. 11β-HSD1 expression in pretreatment biopsy specimens positively correlated with primary tumour size. Expression and activity of 11β-HSD1 in post-treatment biopsies were unrelated to the degree of tumour necrosis following chemotherapy. However, high 11β-HSD2 expression in post-treatment biopsies correlated with a poor response to therapy. OS cells that expressed 11β-HSD2 inactivated endogenous glucocorticoids; but these cells were also able to generate DEX from DHD. These results suggest that OS treatment response is related to 11β-HSD2 enzyme expression. Furthermore, OS cells expressing this enzyme could be targeted by treatment with synthetic glucocorticoids that are selectively reactivated by the enzyme.

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Lou, Deshuai, Qian Long, Cunhong Luo, Xiaoli Zhang, Zixin Zhou, Chunju Zhang, Qiang Li, Xi Liu et Jun Tan. « A novel NAD(H)-dependent 3alpha-HSDH with enhanced activity by magnesium or manganese ions ». International Journal of Biological Macromolecules 204 (avril 2022) : 34–40. http://dx.doi.org/10.1016/j.ijbiomac.2022.01.198.

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Mark, P. J., S. Augustus, D. P. Hewitt et B. J. Waddell. « 203. Partial progesterone withdrawal during late gestation increases placental expression of 11β-HSD1 in the rat ». Reproduction, Fertility and Development 20, n^o 9 (2008) : 3. http://dx.doi.org/10.1071/srb08abs203.

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Fetal glucocorticoid excess programs adverse outcomes in adult offspring, including hypertension, obesity and insulin resistance. Access of maternal glucocorticoids to the fetus is regulated by the placental glucocorticoid barrier which consists of the 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) enzyme and P-glycoprotein (Abcb1). Both proteins act to reduce fetal and placental exposure to active, circulating glucocorticoids. In addition, placental expression of 11β-HSD1 is thought to limit the effectiveness of the barrier by local reactivation of inert glucocorticoids. The present study measured expression of placental 11β-HSD1 and 11β-HSD2 in normal rat pregnancy and after either partial progesterone withdrawal or treatment with dexamethasone, both of which reduce fetal growth. Placentas were collected and dissected into their morphologically- and functionally-distinct zones (junctional and labyrinth) on days 16 and 22 of normal pregnancy (term = 23 days) and after either dexamethasone treatment (0.75 μg/mL in drinking water from day 13) or ovariectomy (day 16) plus full oestrogen and partial progesterone replacement (to approximately one-third of day 22 levels). Junctional and labyrinth zone expression of 11β-HSD1 and 11β-HSD2 mRNA were determined by qRT–PCR. Labyrinthine expression of 11β-HSD1 increased markedly between days 16 and 22 and there was a concomitant decrease in labyrinthine 11β-HSD2 expression. Dexamethasone administration had no effect on the expression of either 11β-HSD isoform in either placental zone. Partial progesterone withdrawal increased 11β-HSD1 expression in both placental zones (1.9 and 3.1-fold in LZ and JZ respectively, P < 0.05), but had no effect on 11β-HSD2 levels. In conclusion, these data confirm the pattern of placental 11β-HSD isoform expression in late rat pregnancy and suggest that that labyrinth zone 11β-HSD1 is normally suppressed by progesterone. Thus, the normal pre-partum decline in circulating progesterone may provide a key stimulus for the marked rise in labyrinth zone 11β-HSD1 that occurs between days 16 and 22 of pregnancy.

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Adamczyk-Popławska, Monika, Aneta Kondrzycka, Katarzyna Urbanek et Andrzej Piekarowicz. « Tetra-amino-acid tandem repeats are involved in HsdS complementation in type IC restriction–modification systems ». Microbiology 149, n^o 11 (1 novembre 2003) : 3311–19. http://dx.doi.org/10.1099/mic.0.26497-0.

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All known type I restriction and modification (R–M) systems of Escherichia coli and Salmonella enterica belong to one of four discrete families: type IA, IB, IC or ID. The classification of type I systems from a wide range of other genera is mainly based on complementation and molecular evidence derived from the comparison of the amino acid similarity of the corresponding subunits. This affiliation was seldom based on the strictest requirement for membership of a family, which depends on relatedness as demonstrated by complementation tests. This paper presents data indicating that the type I NgoAV R–M system from Neisseria gonorrhoeae, despite the very high identity of HsdM and HsdR subunits with members of the type IC family, does not show complementation with E. coli type IC R–M systems. Sequence analysis of the HsdS subunit of several different potential type IC R–M systems shows that the presence of different tetra-amino-acid sequence repeats, e.g. TAEL, LEAT, SEAL, TSEL, is characteristic for type IC R–M systems encoded by distantly related bacteria. The other regions of the HsdS subunits potentially responsible for subunit interaction are also different between a group of distantly related bacteria, but show high similarity within these bacteria. Complementation between the NgoAV R–M system and members of the EcoR124 R–M family can be restored by changing the tetra-amino-acid repeat within the HsdS subunit. The authors propose that the type IC family of R–M systems could consist of several complementation subgroups whose specificity would depend on differences in the conserved regions of the HsdS polypeptide.

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Sadeghi, Zohre, Mahdi Fasihi-Ramandi et Saeid Bouzari. « Brucella antigens (BhuA, 7α-HSDH, FliC) in poly I:C adjuvant as potential vaccine candidates against brucellosis ». Journal of Immunological Methods 500 (janvier 2022) : 113172. http://dx.doi.org/10.1016/j.jim.2021.113172.

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Nomura, Kaoru, Hiroshi Demura, Nobuo Horiba et Kazuo Shizume. « Long-term treatment of idiopathic hyperaldosteronim using trilostane ». Acta Endocrinologica 113, n^o 1 (septembre 1986) : 104–10. http://dx.doi.org/10.1530/acta.0.1130104.

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Abstract. Three patients with idiopathic hyperaldosteronism were continuously treated with trilostane, a competitive inhibitor of adrenal 3β-hydroxysteroid dehydrogenase (3β-HSDH) (3 to 4⅔ years). Trilostane, in conjunction with antihypertensive drugs, effectively decreased plasma aldosterone levels and improved hyperaldosteronism symptoms without undesirable side effects. Trilostane continued to be effective even when treatment was continuous. Rapid ACTH testing (iv bolus of 0.25 mg α1–24 ACTH) was done on the day without trilostane after long-term treatment, and plasma levels of aldosterone and cortisol were compared to those obtained during a pre-treatment period. Results suggest that the inhibitory effect of trilostane on steroid biosynthesis rapidly disappears following discontinuance of trilostane administration even after long-term treatment, and that continuous treatment causes no significant or irreversible change in steroid biosynthesis. These results suggest that trilostane is a safe, feasible therapeutic agent for long-term treatment of idiopathic hyperaldosteronism.

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Kupczyk, Daria, Renata Studzińska, Rafał Bilski, Szymon Baumgart, Renata Kołodziejska et Alina Woźniak. « Synthesis of Novel 2-(Isopropylamino)thiazol-4(5H)-one Derivatives and Their Inhibitory Activity of 11β-HSD1 and 11β-HSD2 in Aspect of Carcinogenesis Prevention ». Molecules 25, n^o 18 (15 septembre 2020) : 4233. http://dx.doi.org/10.3390/molecules25184233.

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Glucocorticoid metabolism at the tissue level is regulated by two isoenzymes 11β-hydroxysteroid dehydrogenase (11β-HSD), which mutually convert biologically active cortisol and inactive cortisone. Recent research is focused on the role of 11β-HSD1 and 11β-HSD2 as autocrine factors of tumor cell proliferation and differentiation. Herein, we report the synthesis of novel 2-(isopropylamino)thiazol-4(5H)-one derivatives and their inhibitory activity for 11β-HSD1 and 11β-HSD2. The derivative containing the spiro system of thiazole and cyclohexane rings shows the highest degree of 11β-HSD1 inhibition (54.53% at 10 µM) and is the most selective inhibitor of this enzyme among the tested compounds. In turn, derivatives containing ethyl and n-propyl group at C-5 of thiazole ring inhibit the activity of 11β-HSD2 to a high degree (47.08 and 54.59% at 10 µM respectively) and are completely selective. Inhibition of the activity of these enzymes may have a significant impact on the process of formation and course of tumors. Therefore, these compounds can be considered as potential pharmaceuticals supporting anti-cancer therapy.

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Bakonyi, Daniel, Astrid Wirtz et Werner Hummel. « Large-scale Enzymatic Synthesis of 12-Ketoursodeoxycholic Acid from Dehydrocholic Acid by Simultaneous Combination of 3α-Hydroxysteroid Dehydrogenase from Pseudomonas testosteroni and 7β-Hydroxysteroid Dehydrogenase from Collinsella aerofaciens ». Zeitschrift für Naturforschung B 67, n^o 10 (1 octobre 2012) : 1037–44. http://dx.doi.org/10.5560/znb.2012-0165.

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12-Keto-UDCA is an important optically active component for the drug ursodeoxycholic acid (UDCA). Starting from the three-keto compound dehydrocholic acid, the carbonyl groups at position 3 and 7 have to be reduced stereo- and regioselectively. In this case we applied two hydroxysteroid dehydrogenases for this purpose, the NAD-dependent 3α-HSDH from Pseudomonas testosteroni and the NADP-dependent 7β-hydroxysteroid dehydrogenase from Collinsella aerofaciens. Both enzymes can be produced in high yields by an Escherichia coli strain as recombinant proteins. In order to avoid impurities by the 7a-hydroxysteroid dehydrogenase of Escherichia coli, a mutant strain with an inactivated 7a-enzyme was applied for producing the three enzymes. For bioconversion, the dehydrogenases can be used as crude enzyme samples and are applied simultaneously. A 1.8 L batch of 100mM DHCA incubated at pH = 8.0 and 25°C resulted in 80 g crude product with a quite high purity of ≥ 99:5% as judged by HPLC analysis.

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Qi, Jia, Wangsheng Wang, Qinling Zhu, Yaqiong He, Yao Lu, Yuan Wang, Xiaoxue Li, Zi-jiang Chen et Yun Sun. « Local Cortisol Elevation Contributes to Endometrial Insulin Resistance in Polycystic Ovary Syndrome ». Journal of Clinical Endocrinology & ; Metabolism 103, n^o 7 (30 mars 2018) : 2457–67. http://dx.doi.org/10.1210/jc.2017-02459.

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Abstract Context Endometrial insulin resistance (IR) may account for the endometrial dysfunction in polycystic ovary syndrome (PCOS). The underlying mechanism remains to be elucidated. Objective To investigate whether the abundance of 11β-hydroxysteroid dehydrogenases (11β-HSDs) 1 and 2 and cortisol as well as the insulin signaling pathway are altered in PCOS endometrium and to clarify the relationship between endometrial IR and local cortisol. Design We measured cortisol and cortisone concentrations, 11β-HSD1 and 11β-HSD2, and core insulin signaling molecules in endometrial biopsies collected from non-PCOS and PCOS with or without IR patients on the seventh day after human chorionic gonadotropin injection. We also studied the effects of cortisol on glucose uptake and the insulin signaling pathway in primary cultured endometrial epithelial cells (EECs). Results The cortisol concentration was elevated, whereas 11β-HSD2 expression was diminished in endometrial biopsies obtained from PCOS with IR patients compared with those from non-PCOS and PCOS without IR patients. The implantation rate was relatively impaired and the endometrial insulin signaling pathway was defective in PCOS with IR patients. In addition, cortisol attenuated insulin-stimulated glucose uptake in EECs, which was mediated by inhibition of Akt phosphorylation and glucose transporter type 4 translocation via induction of phosphatase and tensin homolog deleted on chromosome ten (PTEN). Conclusions Decreased oxidation of cortisol and defects of insulin signaling in endometrium were observed in PCOS with IR patients. The excessive cortisol level, derived from the reduction of 11β-HSD2, might contribute to the development of endometrial IR by inhibiting the insulin signaling pathway via induction of PTEN expression in EECs.

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Draper, Nicole, et Paul M. Stewart. « 11β-Hydroxysteroid dehydrogenase and the pre-receptor regulation of corticosteroid hormone action ». Journal of Endocrinology 186, n^o 2 (août 2005) : 251–71. http://dx.doi.org/10.1677/joe.1.06019.

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Two isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD1 and 11β-HSD2) catalyse the interconversion of hormonally active cortisol and inactive cortisone. The enzyme evolved from a metabolic pathway to a novel mechanism underpinning human disease with the elucidation of the role of the type 2 or ‘kidney’ isozyme and an inherited form of hypertension, ‘apparent mineralocorti-coid excess’. ‘Cushing’s disease of the kidney’ arises because of a failure of 11β-HSD2 to inactivate cortisol to cortisone resulting in cortisol-induced mineralocorticoid excess. Conversely, 11β-HSD1 has been linked to human obesity and insulin resistance, but also to other diseases in which glucocorticoids have historically been implicated (osteoporosis, glaucoma). Here, the activation of cortisol from cortisone facilitates glucocorticoid hormone action at an autocrine level. The molecular basis for the putative human 11β-HSD1 ‘knockout’ – ‘cortisone reductase deficiency’ - has recently been described, an observation that also answers a long standing conundrum relating to the set-point of 11β-HSD1 activity. In each case, these clinical studies have been underpinned by studies in vitro and the manipulation of enzyme expression in vivo using recombinant mouse models.

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Al-Masoudi, Najim A., Abbas Sami, Nabeel A. Abdul-Rida et Martin Fortscher. « New cholic acid analogs : synthesis and 17β-hydroxydehydrogenase (17β-HSD) inhibition activity ». Zeitschrift für Naturforschung B 73, n^o 3-4 (25 avril 2018) : 211–23. http://dx.doi.org/10.1515/znb-2018-0192.

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AbstractThe 17β-hydroxysteroid dehydrogenase (17β-HSD) enzyme family is involved in the biosynthesis of active steroids and its inhibition constitutes an interesting approach for treating estrogen-, androgen-dependent cancers and osteoporosis. In this study, a new series of cholic acid analogs was designed with the goal of improving the biological activity as 17β-HSD1 and 17β-HSD2 inhibitors. To this end, 23-cholyl amides4–7, 3-O-p-toluenesulfonyl-23-cholyl amides10–12, 23-cholyl-carbohydrazide14, carbothioamide analog15, and 23-cholyl-acylhydrazone derivatives18–22were synthesized from cholic acid (3)viacoupling, sulfonation and substitution reactions. Basic treatment of keto group of5withp-bromoaniline afforded8, meanwhile acidic treatment of3with thiosemicarbazide furnished the 23-cholyl-thiadiazole derivative16. The synthesized compounds were evaluated for their inhibition activity against 17β-HSD1 and 17β-HSD2, and were found inactive at 1.0 μmconcentration (inhibition <10%). However, the steroids12,21and22showed inhibition of 21.1, 23.9 and 21.3%, respectively, against 17β-HSD2 at the same concentration. Therefore, these steroidal analogs can be further structurally modified to optimize their inhibition activity against 17β-HSD2 for the development of potential therapeutics.

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Raleigh, E. A., R. Trimarchi et H. Revel. « Genetic and physical mapping of the mcrA (rglA) and mcrB (rglB) loci of Escherichia coli K-12. » Genetics 122, n^o 2 (1 juin 1989) : 279–96. http://dx.doi.org/10.1093/genetics/122.2.279.

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Abstract We have genetically analyzed, cloned and physically mapped the modified cytosine-specific restriction determinants mcrA (rglA) and mcrB (rglB) of Escherichia coli K-12. The independently discovered Rgl and Mcr restriction systems are shown to be identical by three criteria: 1) mutants with the RglA- or RglB- phenotypes display the corresponding McrA- or McrB- phenotypes, and vice versa; 2) the gene(s) for RglA and McrA reside together at one locus, while gene(s) for RglB and McrB are coincident at a different locus; and 3) RglA+ and RglB+ recombinant clones complement for the corresponding Mcr-deficient lesions. The mcrA (rglA) gene(s) is on the excisable element e14, just clockwise of purB at 25 min. The mcrB (rglB) gene(s), at 99 min, is in a cluster of restriction functions that includes hsd and mrr, determinants of host-specific restriction (EcoK) and methyladenine-specific restriction respectively. Gene order is mcrB-hsdS-hsdM-hsdR-mrr-serB. Possible models for the acqusition of these restriction determinants by enteric bacteria are discussed.

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Kupczyk, Daria, Renata Studzińska, Szymon Baumgart, Rafał Bilski, Tomasz Kosmalski, Renata Kołodziejska et Alina Woźniak. « A Novel N-Tert-Butyl Derivatives of Pseudothiohydantoin as Potential Target in Anti-Cancer Therapy ». Molecules 26, n^o 9 (29 avril 2021) : 2612. http://dx.doi.org/10.3390/molecules26092612.

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Tumors are currently more and more common all over the world; hence, attempts are being made to explain the biochemical processes underlying their development. The search for new therapeutic pathways, with particular emphasis on enzymatic activity and its modulation regulating the level of glucocorticosteroids, may contribute to the development and implementation of new therapeutic options in the treatment process. Our research focuses on understanding the role of 11β-HSD1 and 11β-HSD2 as factors involved in the differentiation and proliferation of neoplastic cells. In this work, we obtained the 9 novel N-tert-butyl substituted 2-aminothiazol-4(5H)-one (pseudothiohydantoin) derivatives, differing in the substituents at C-5 of the thiazole ring. The inhibitory activity and selectivity of the obtained derivatives in relation to two isoforms of 11β-HSD were evaluated. The highest inhibitory activity for 11β-HSD1 showed compound 3h, containing the cyclohexane substituent at the 5-position of the thiazole ring in the spiro system (82.5% at a conc. 10 µM). On the other hand, the derivative 3f with the phenyl substituent at C-5 showed the highest inhibition of 11β-HSD2 (53.57% at a conc. of 10 µM). A low selectivity in the inhibition of 11β-HSD2 was observed but, unlike 18β-glycyrrhetinic acid, these compounds were found to inhibit the activity of 11β-HSD2 to a greater extent than 11β-HSD1, which makes them attractive for further research on their anti-cancer activity.

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Papacleovoulou, Georgia, Hilary O. D. Critchley, Stephen G. Hillier et J. Ian Mason. « IL1α and IL4 signalling in human ovarian surface epithelial cells ». Journal of Endocrinology 211, n^o 3 (8 septembre 2011) : 273–83. http://dx.doi.org/10.1530/joe-11-0081.

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The human ovarian surface epithelium (hOSE) is a mesothelial layer that surrounds the ovary and undergoes injury and repair cycles after ovulation-associated inflammation. We previously showed that IL4 is a key regulator of progesterone bioavailability during post-ovulatory hOSE repair as it differentially up-regulated 3β-HSD1 and 3β-HSD2 mRNA transcripts and total 3β-hydroxysteroid dehydrogenase activity whereas it inhibited androgen receptor (AR) expression. We now show that the pro-inflammatory effect of IL1α on 3β-HSD1 expression is mediated by nuclear factor-κB (NF-κB), whereas its anti-inflammatory action on 3β-HSD2 expression is exerted via p38 mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K) and NF-κB signalling pathways. The anti-inflammatory IL4 effects on 3β-HSD1 and 3β-HSD2 mRNA expression are mediated through STAT6 and PI3K signalling networks. IL4 effects on AR and 3β-HSD2 expression involve the p38 MAPK pathway. We also document that IL4 up-regulates lysyl oxidase (LOX) mRNA transcripts, a key gene for extracellular matrix (ECM) deposition and inhibits IL1α-induced expression of cyclooxygenase-2 (COX-2) mRNA, a gene involved in breakdown of ECM, showing a further role in post-ovulatory wound healing. We conclude that IL1α and IL4 actions in the post-ovulatory wound healing of hOSE cells are mediated by different signalling transduction pathways. The p38 MAPK signalling pathway may have possible therapeutic benefit in inflammation-associated disorders of the ovary, including cancer.

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Bujalska, Iwona J., Nicole Draper, Zoi Michailidou, Jeremy W. Tomlinson, Perrin C. White, Karen E. Chapman, Elizabeth A. Walker et Paul M. Stewart. « Hexose-6-phosphate dehydrogenase confers oxo-reductase activity upon 11β-hydroxysteroid dehydrogenase type 1 ». Journal of Molecular Endocrinology 34, n^o 3 (juin 2005) : 675–84. http://dx.doi.org/10.1677/jme.1.01718.

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Two isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD) interconvert active cortisol and inactive cortisone. 11β-HSD2 (renal) acts only as a dehydrogenase, converting cortisol to cortisone. 11β-HSD1 (liver) is a bi-directional enzyme in cell homogenates, whereas in intact cells it typically displays oxo-reductase activity, generating cortisol from cortisone. We recently established that cortisone reductase deficiency is a digenic disease requiring mutations in both the gene encoding 11β-HSD1 and in the gene for a novel enzyme located within the lumen of the endoplasmic reticulum (ER), hexose-6-phosphate dehydrogenase (H6PDH). This latter enzyme generates NADPH, the co-factor required for oxo-reductase activity. Therefore, we hypothesized that H6PDH expression may be an important determinant of 11β-HSD1 oxo-reductase activity. Transient transfection of chinese hamster ovary (CHO) cells with 11β-HSD1 resulted in the appearance of both oxo-reductase and dehydrogenase activities in intact cells. Co-transfection of 11β-HSD1 with H6PDH increased oxo-reductase activity whilst virtually eliminating dehydrogenase activity. In contrast, H6PDH had no effect on reaction direction of 11β-HSD2, nor did the cytosolic enzyme, glucose-6-phosphate dehydrogenase (G6PD) affect 11β-HSD1 oxo-reductase activity. Conversely in HEK 293 cells stably transfected with 11β-HSD1 cDNA, transfection of an H6PDH siRNA reduced 11β-HSD1 oxo-reductase activity whilst simultaneously increasing 11β-HSD1 dehydrogenase activity. In human omental preadipocytes obtained from 15 females of variable body mass index (BMI), H6PDH mRNA levels positively correlated with 11β-HSD1 oxo-reductase activity, independent of 11β-HSD1 mRNA levels. H6PDH expression increased 5.3-fold across adipocyte differentiation (P<0.05) and was associated with a switch from 11β-HSD1 dehydrogenase to oxo-reductase activity. In conclusion, H6PDH is a crucial determinant of 11β-HSD1 oxo-reductase activity in intact cells. Through its interaction with 11β-HSD1, H6PDH may represent a novel target in the pathogenesis and treatment of obesity.

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