Novel enzymological profiles of human 11β-hydroxysteroid dehydrogenase type 1

The human enzyme 11β-hydroxysteroid dehydrogenase (11β-HSD) catalyzes the reversible oxidoreduction of 11β-OH/11-oxo groups of glucocorticoid hormones. Besides this important endocrinological property, the type 1 isozyme (11β-HSD1) mediates reductive phase I reactions of several carbonyl group bearing xenobiotics, including drugs, insecticides and carcinogens. The aim of this study was to explore novel substrate specificities of human 11β-HSD1, using heterologously expressed protein in the yeast system Pichia pastoris. In addition to established phase I xenobiotic substrates, it is now demonstrated that transformed yeast strains catalyze the reduction of ketoprofen to its hydroxy metabolite, and the oxidation of the prodrug DFU-lactol to the pharmacologically active lactone compound. Purified recombinant 11β-HSD1 mediated oxidative reactions, however, the labile reductive activity component could not be maintained. In conclusion, evidence is provided that human 11β-HSD1 in vitro is involved in phase I reactions of anti-inflammatory non-steroidal drugs like ketoprofen and DFU-lactol.     

Expression and NNK reducing activities of carbonyl reductase and 11β-hydroxysteroid dehydrogenase type 1 in human lung

The tobacco specific nitrosamine 4-methylnitrosamino-1-(3-pyridyl)-1-butanone (NNK), which is found in high amounts in tobacco products, is believed to play an important role in lung cancer induction in smokers. NNK requires metabolic activation by cytochrome P450 mediated α-hydroxylation to exhibit its carcinogenic properties. On the other hand, NNK is inactivated by carbonyl reduction to its alcohol-equivalent 4-methylnitrosamino-1-(3-pyridyl)-1-butanol (NNAL) followed by glucuronidation and final excretion into urine or bile. Carbonyl reduction and α-hydroxylation are the predominant pathways in man, and it has been postulated that the extent of these competing pathways determines the individual susceptibility to lung cancer. Moreover, only a minor part of all habitual smokers develop lung cancer, suggesting the existence of susceptibility genes. Microsomal 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD 1) (EC 1.1.1.146) and cytosolic carbonyl reductase (CR) (EC 1.1.1.184) have been shown to be mainly responsible for NNAL formation in liver and lung. In the present study, we performed comparative investigations of human lung tissue samples from several patients with respect to the expression and activity of 11β-HSD 1 and carbonyl reductase. We observed varying levels in 11β-HSD 1 and carbonyl reductase expression in these patients, as revealed by RT-PCR and ELISA. Also, the tissue samples showed a different activity and inhibitor profile for both enzymes. According to our results, variations in the expression and activity of NNK carbonyl reducing enzymes may constitute a major determinant in the overall NNK detoxification capacity and thus may be linked to the great differences observed in the individual susceptibility of tobacco-smoke related lung cancer.     

BVT.2733, a selective 11β-hydroxysteroid dehydrogenase type 1 inhibitor, attenuates obesity and inflammation in diet-induced obese mice

Background

Inhibition of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is being pursued as a new therapeutic approach for the treatment of obesity and metabolic syndrome. Therefore, there is an urgent need to determine the effect of 11β-HSD1 inhibitor, which suppresses glucocorticoid action, on adipose tissue inflammation. The purpose of the present study was to examine the effect of BVT.2733, a selective 11β-HSD1 inhibitor, on expression of pro-inflammatory mediators and macrophage infiltration in adipose tissue in C57BL/6J mice.

Methodology/Principal Findings

C57BL/6J mice were fed with a normal chow diet (NC) or high fat diet (HFD). HFD treated mice were then administrated with BVT.2733 (HFD+BVT) or vehicle (HFD) for four weeks. Mice receiving BVT.2733 treatment exhibited decreased body weight and enhanced glucose tolerance and insulin sensitivity compared to control mice. BVT.2733 also down-regulated the expression of inflammation-related genes including monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α) and the number of infiltrated macrophages within the adipose tissue in vivo. Pharmacological inhibition of 11β-HSD1 and RNA interference against 11β-HSD1 reduced the mRNA levels of MCP-1 and interleukin-6 (IL-6) in cultured J774A.1 macrophages and 3T3-L1 preadipocyte in vitro.

Conclusions/Significance

These results suggest that BVT.2733 treatment could not only decrease body weight and improve metabolic homeostasis, but also suppress the inflammation of adipose tissue in diet-induced obese mice. 11β-HSD1 may be a very promising therapeutic target for obesity and associated disease.     

Structural assessment and identification of 11β-hydroxysteroid dehydrogenase type 1 inhibitors

Communicated by Ramaswamy H. Sarma     

Adamantyl carboxamides and acetamides as potent human 11β-hydroxysteroid dehydrogenase type 1 inhibitors

The modulation of 11β-HSD1 activity with selective inhibitors has beneficial effects on various metabolic disorders including insulin resistance, dyslipidemia and obesity. Here we report the discovery of a series of novel adamantyl carboxamide and acetamide derivatives as selective inhibitors of human 11β-HSD1 in HEK-293 cells transfected with the HSD11B1 gene. Optimization based on an initially identified 11β-HSD1 inhibitor (3) led to the discovery of potent inhibitors with IC₅₀ values in the 100 nM range. These compounds are also highly selective 11β-HSD1 inhibitors with no activity against 11β-HSD2 and 17β-HSD1. Compound 15 (IC₅₀ = 114 nM) with weak inhibitory activity against the key human cytochrome P450 enzymes and moderate stability in incubation with human liver microsomes is worthy of further development. Importantly, compound 41 (IC₅₀ = 280 nM) provides a new lead that incorporates an adamantyl group surrogate and should enable further series diversification.     

Alteration of 11β-hydroxysteroid dehydrogenase type 1 in skeletal muscle in a rat model of type 2 diabetes

Recent investigations have demonstrated that activation of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in liver and adipose tissue is closely related to the pathogenesis of obesity and diabetes. However, the relationship between alteration of 11β-HSD1 and the pathogenesis of type 2 diabetes in skeletal muscle is still unclear. A rat model of Type 2 diabetes was developed by high fat diet feeding combined with multiple low dose streptozotocin injection (30 mg/kg, i.p. twice). Intraperitoneal glucose tolerance test, insulin tolerance test were performed. Fasting blood glucose, fasting insulin, total cholesterol, triglyceride were measured. The protein and mRNA level of 11β-HSD1 and glucocorticoid receptor in gastrocnemius muscle were determined. The alteration of insulin signaling pathway related protein was investigated. We found that the protein levels of 11β-HSD1 and glucocorticoid receptor were significantly increased (P < 0.05); the mRNA level of 11β-HSD1 was also elevated (P < 0.05); the mRNA level of glucocorticoid receptor was decreased (P < 0.05). After insulin stimulation, diabetic rats had no significant changes in the level of the insulin receptor β-subunit (IR-β), AKT, as in phosphorylated AKT in the gastrocnemius muscle compared to its basal state. Similar results were observed in the protein expression level of glucose transporter 4 (GLUT4). Our data indicate that the alteration of 11β-HSD1 at protein and mRNA level may be related to the abnormality of insulin signal pathway in skeletal muscle, this effect may be mediated by glucocorticoid receptor.     

Upregulation of 11β-hydroxysteroid dehydrogenase 1 in lymphoid organs during inflammation in the rat

Glucocorticoids exert anti-inflammatory and immunomodulatory effects that may be regulated in part by the activities of the glucocorticoid-activating and -inactivating enzymes, 11β-hydroxysteroid dehydrogenase type 1 (11HSD1) and type 2 (11HSD2), respectively. Previous studies have demonstrated that inflammatory bowel diseases in humans and experimental animals upregulate 11HSD1 and downregulate 11HSD2. We investigated whether proinflammatory cytokines modulate colonic 11HSDs as well as whether lymphoid organs exhibit any 11HSD response to inflammation. Colon tissue explants exposed to tumor necrosis factor α exhibited an upregulation of 11HSD1 mRNA whereas interleukin 1β downregulated 11HSD2 mRNA. Experimental colitis induced by the intracolonic administration of 2,4,6-trinitrobenzenesulfonic acid stimulated 11HSD1 activity not only in the colon but also in mesenteric lymph nodes and the spleen. Analysis of mRNA for 11HSD1 in colon-draining lymph nodes and the spleen showed that inflammation upregulates the expression of this enzyme in mobile lymphoid cells similar to the intraepithelial and lamina propria leukocytes isolated from the colon. It is inferred that inflammation stimulates the reactivation of glucocorticoids in lymphoid organs and in gut-associated lymphoid tissue.     

Molecular cloning and expression of 17β-hydroxysteroid dehydrogenase type 2 gene in Hu sheep

17β-Hydroxysteroid dehydrogenase type 2 (17β-HSD2) catalyzes the NADP+-dependent oxidation of the most potent estrogen 17β-estradiol into the weak estrogen estrone, and the conversion of testosterone to androstenedione. It has been reported that 17β-HSD2 was expressed in many tissues in human, rats, however, the full-length sequence of 17β-HSD2 gene and its expression in ewe were still unknown. In this study, we cloned the full-length cDNA sequence and investigated mRNA differential expression in 28 tissues of 12 adult Hu-Sheep which were fed with high- and low- dietary intake. The 1,317 bp full-length cDNA sequence was first cloned. The coding region was 1,167 bp in length, and the monomer was estimated to contain 389 amino acid residues. It shares high AA sequence identity with that of bos Taurus (96.13 %), sus scrofa (77.06 %), canis lupus familiaris (70.44 %), Callithrix jacchus (65.72 %), Nomascus leucogenys (65.46 %), pan troglodytes (65.21 %), human (64.69 %), mus musculus (58.35 %), and a comparatively lower identity to danio rerio (37.85 %). 17β-HSD2 gene was high expressed in gastrointestinal (GI) tract, liver, but weakly expressed in other tissues. No detected expression was examined in lung. 17β-HSD2 gene expression was significantly difference in rumen, omasum, duodenum, cecum, hypophysis after high- and low- dietary intake. Results from the present study suggested that 17β-HSD2 plays a crucial role in almost all tissues protecting against excessive levels of active steroid hormone, and GI tract maybe an important steroid hormone metabolizing organ in Hu-Sheep. This present study is the first to provide the primary foundation for further insight into this ovine gene.     

Effects of phthalates on 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase 3 activities in human and rat testes

The 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3) are involved in the reactions that culminate in androgen biosynthesis in Leydig cells. Human and rat testis microsomes were used to investigate the inhibitory potencies on 3β-HSD and 17β-HSD3 activities of 14 different phthalates with various carbon numbers in the ethanol moiety. The results demonstrated that the half-maximal inhibitory concentrations (IC(50)s) of dipropyl (DPrP), dibutyl (DBP), dipentyl (DPP), bis(2-butoxyethyl) (BBOP) and dicyclohexyl (DCHP) phthalate were 123.0, 24.1, 25.5, 50.3 and 25.5μM for human 3β-HSD activity, and 62.7, 30.3, 33.8, 82.6 and 24.7μM for rat 3β-HSD activity, respectively. However, only BBOP and DCHP potently inhibited human (IC(50)s, 23.3 and 8.2μM) and rat (IC(50)s, 30.24 and 9.1μM) 17β-HSD3 activity. Phthalates with 1-2 or 7-8 carbon atoms in ethanol moieties had no effects on both enzyme activities even at concentrations up to 1mM. The mode of action of DCHP on 3β-HSD activity was competitive with the substrate pregnenolone but noncompetitive with the cofactor NAD+. The mode of action of DCHP on 17β-HSD3 activity was competitive with the substrate androstenedione but noncompetitive with the cofactor NADPH. In summary, our results showed that there are clear structure-activity responses for phthalates in the inhibition of both 3β-HSD and 17β-HSD3 activities. The length of carbon chains in the ethanol moieties of phthalates may determine the potency to inhibit these two enzymes.     

Regulation of 11β-hydroxysteroid dehydrogenase 1 and 2 by IGF-1 in mice

Two isoforms of 11β-hydroxysteroid dehydrogenase (11β-HSD1 and 11β-HSD2) play an important role in regulation of glucocorticoid corticosterone (CORT, the active form in rodents) by the interconversion between CORT and 11-dehydrocorticosterone (11DHC, the biologically inert form). 11β-HSD1 is an NADP+/NADPH-dependent oxidoreductase which is mainly expressed in liver and kidney, while 11β-HSD2 is an NAD+-dependent oxidase which is predominantly expressed in kidney. The regulation of 11β-HSD1 and 11β-HSD2 mRNA (Hsd11b1 and Hsd11b2) levels and their activities by IGF-1 was performed in liver, kidney, and testis of IGF-1 knockout male mice. Real-time PCR showed that Hsd11b1 in liver was decreased while Hsd11b2 mRNA level was decreased in kidney of IGF-1 null mice. 11β-HSD1 and 11β-HSD2 activities fluctuated with the changes of their respective Hsd11b1 or Hsd11b2 mRNA levels. In conclusion, IGF-I tissue-specifically regulates Hsd11b1 and Hsd11b2 expression.     

Structure, function and tissue-specific gene expression of 3β-hydroxysteroid dehydrogenase/5-ene-4-ene isomerase enzymes in classical and peripheral intracrine steroidogenic tissues

The membrane-bound enzyme 3β-hydroxysteroid dehydrogenase/5-ene-4-ene isomerase (3β-HSD) catalyses an essential step in the transformation of all 5-pregnen-3β-ol and 5-androsten-3β-ol steroids into the corresponding 3-keto-4-ene-steroids, namely progesterone as well as all the precursors of androgens, estrogens, glucocorticoids and mineralocorticoids. We have recently characterized two types of human 3β-HSD cDNA clones and the corresponding genes which encode type I and II 3β-HSD isoenzymes of 372 and 371 amino acids, respectively, and share 93.5% homology. The human 3β-HSD genes containing 4 exons were assigned by in situ hybridization to the p11-p13 region of the short arm of chromosome 1. Human type I 3β-HSD is the almost exclusive mRNA species present in the placenta and skin while the human type II is the predominant mRNA species in the adrenals, ovaries and testes. The type I protein possesses higher 3β-HSD activity than type II. We elucidated the structures of three types of rat 3β-HSD cDNAs as well that of one type of 3β-HSD from bovine and macaque ovary λgt11 cDNA libraries, which all encode a 372 amino acid protein. The rat type I and II 3β-HSD proteins expressed in the adrenals, gonads and adipose tissue share 93.8% homology. Transient expression of human type I and II as well as rat type I and II 3β-HSD cDNAs in HeLa human cervical carcinoma cells reveals that 3β-ol dehydrogenase and 5-ene-4-ene isomerase activities reside within a single protein. These expressed 3β-HSD proteins convert 3β-hydroxy-5-ene-steroids into 3-keto-4-ene derivatives and catalyze the interconversion of 3β-hydroxy and 3-keto-5α-androstane steroids. By site-directed mutagenesis, we demonstrated that the lower activity of expressed rat type II compared to rat type I 3β-HSD is due to a change of four residues probably involved in a membrane-spanning domain. When homogenates from cells transfected with a plasmid vector containing rat type I 3β-HSD is incubated in the presence of dihydrotestosterone (DHT) using NAD? as co-factor, 5α-androstanedione was formed (A-dione), indicating an intrinsic androgenic 17β-hydroxysteroid dehydrogenase (17β-HSD) activity of this 3β-HSD. We cloned a third type of rat cDNA encoding a predicted type III 3β-HSD specifically expressed in the rat liver, which shares 80% similarity with the two other isoenzymes. Transient expression in human HeLa cells reveals that the type III isoenzyme does not display oxidative activity for the classical substrates of 3β-HSD. However, in common with the type I enzyme, it converts A-dione and DHT to the corresponding 3β-hydroxysteroids, thus showing an exclusive 3-ketosteroid reductase activity. When NADPH is used as co-factor, the affinity for DHT of the type III enzyme becomes 10-fold higher than that of the type I. Rat type III mRNA was below the detection limit in intact female liver. Following hypophysectomy, its concentration increased to 55% of the values measured in intact or hypophysectomized male rats, an increase which can be blocked by administration of ovine prolactin (oPRL). Treatment with oPRL for 10 days starting 15 days after hypophysectomy markedly decreased ovarian 3β-HSD mRNA accumulation accompanied by a similar decrease in 3β-HSD activity and protein levels. Treatment with the gonadotropin hCG reversed the potent inhibitory effect of oPRL on these parameters and stimulated 3β-HSD mRNA levels in ovarian interstitial cells. These data indicate that the presence of multiple 3β-HSD isoenzymes offers the possibility of tissue-specific expression and regulation of this enzymatic activity that plays an essential role in the biosynthesis of all hormonal steroids in classical as well as peripheral intracrine steroidogenic tissues.     

Synthesis and optimization of arylsulfonylpiperazines as a novel class of inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1)

The synthesis and SAR of a series of arylsulfonylpiperazine inhibitors of 11β-HSD1 are described. Optimization rapidly led to potent, selective, and orally bioavailable inhibitors demonstrating efficacy in a cynomolgus monkey ex vivo enzyme inhibition model.     

Momordica charantia extract, a herbal remedy for type 2 diabetes, contains a specific 11β-hydroxysteroid dehydrogenase type 1 inhibitor

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the intracellular regeneration of active cortisol from inert cortisone in key metabolic tissues, thus regulating ligand access to glucocorticoid receptors. There is strong evidence that increased adipose 11β-HSD1 activity may be an important aetiological factor in the current obesity and diabetes type 2 epidemics. Hence, inhibition of 11β-HSD1 has emerged as a promising anti-diabetic strategy, a concept that is largely supported by numerous studies in rodent models as well as limited clinical data with prototype inhibitors. Momordica charantia (also known as bitter melon, bitter gourd or karela) is traditionally used for treatment of diabetes in Asia, South America, the Caribbean, and East Africa. In the present study, we show that M. charantia extract capsules contain at least one ingredient with selective 11β-HSD1 inhibitory activity. The finding constitutes an interesting additional explanation for the well-documented anti-diabetic and hypoglycaemic effects of M. charantia.     

The inhibitory effects of perfluoroalkyl substances on human and rat 11β-hydroxysteroid dehydrogenase 1

Perfluoroalkyl substances (PFASs) are man-made polyfluorinated compounds that are widely used and persistent in the environment. PFASs have potential effects on many biological systems including the development of lung. Glucocorticoids have been reported to promote fetal and neonatal lung development at the late stage, and 11β-hydroxysteroid dehydrogenase 1(11βHSD1) in the lung is critical for the generation of local active glucocorticoid cortisol (human) or corticosterone (rodents) from biologically inert 11keto-steroids. The purpose of the present study is to study the direct inhibitory effects of PFASs on 11βHSD1 activities and action modes. Microsomal 11βHSD1 was subjected to the exposure to various PFASs, including perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), potassium perfluorohexanesulfonate (PFHxS) and potassium perfluorobutane sulfonate (PFBS). PFOS and PFOA inhibited neonatal rat lung 11βHSD1 activity with IC(50)s of 3.45μM (95% Confidence Intervals, CI(95): 1.97-6.37μM) and 45.31μM (CI(95): 27.64-74.26μM), respectively, while PFHxS and PFBS did not inhibit the enzyme activity at 250μM. PFOS and PFOA inhibited human 11βHSD1 activity with IC(50)s of 7.56μM (CI(95): 2.86-19.97μM) and 37.61μM (CI(95): 24.49-57.75μM), respectively, while PFHxS and PFBS did not inhibit the enzyme activity at 250μM. PFASs showed competitive inhibition on both human and rat 11βHSD1. In conclusion, the present study shows that PFOS and PFOA are the inhibitors of 11βHSD1.     

Central glucocorticoid administration promotes weight gain and increased 11β-hydroxysteroid dehydrogenase type 1 expression in white adipose tissue

Glucocorticoids (GCs) are involved in multiple metabolic processes, including the regulation of insulin sensitivity and adipogenesis. Their action partly depends on their intracellular activation by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). We previously demonstrated that central GC administration promotes hyperphagia, body weight gain, hyperinsulinemia and marked insulin resistance at the level of skeletal muscles. Similar dysfunctions have been reported to occur upon specific overexpression of 11β-HSD1 in adipose tissue. The aim of the present study was therefore to determine whether the effects of central GC infusion may enhance local GC activation in white adipose tissue. Male Wistar and Sprague Dawley (SD) rats were intracerebroventricularly infused with GCs for 2 to 3 days. Body weight, food intake and metabolic parameters were measured, and expression of enzymes regulating 11β-HSD1, as well as that of genes regulated by GCs, were quantified. Central GC administration induced a significant increase in body weight gain and in 11β-HSD1 and resistin expression in adipose tissue. A decrease 11β-HSD1 expression was noticed in the liver of SD rats, as a partial compensatory mechanism. Such effects of GCs are centrally elicited. This model of icv dexamethasone infusion thus appears to be a valuable acute model, that helps delineating the initial metabolic defects occurring in obesity. An impaired downregulation of intracellular GC activation in adipose tissue may be important for the development of insulin resistance.     

Design, synthesis, and SAR studies of novel polycyclic acids as potent and selective inhibitors of human 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1)

Starting from high throughput screening hit 2-adamantyl acetic acid 3, a series of polycyclic acids have been designed and synthesized as novel, potent, and selective inhibitors of human 11β-HSD-1. Structure-activity relationships of two different regions of the chemotype (polycyclic ring and substituents on quaternary carbon) are discussed.     

Reciprocal regulation of 11��-hydroxysteroid dehydrogenase 1 and glucocorticoid receptor expression by dexamethasone inhibits human coronary artery smooth muscle cell proliferation in vitro

The actions of glucocorticoids are mediated, in part, by 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1), which amplifies their effects at the pre-receptor level by converting cortisone to cortisol. Glucocorticoids, such as dexamethasone, inhibit vascular smooth muscle cell proliferation; however, the role of 11β-HSD1 in this response remains unknown. Accordingly, we treated human coronary artery smooth muscle cells (HCSMC) with dexamethasone (10(-9)-10(-6) mol/l) and found that after 72?h dexamethasone increased 11β-HSD1 expression (14.16?±?1.6-fold, P?相似文献