Transgenic amplification of glucocorticoid action in adipose tissue causes high blood pressure in mice

Inhibition of the glucocorticoid-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 drives concurrent 11-oxygenated androgen excess

Aldo-keto reductase 1C3 (AKR1C3) is a key enzyme in the activation of both classic and 11-oxygenated androgens. In adipose tissue, AKR1C3 is co-expressed with 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1), which catalyzes not only the local activation of glucocorticoids but also the inactivation of 11-oxygenated androgens, and thus has the potential to counteract AKR1C3. Using a combination of in vitro assays and in silico modeling we show that HSD11B1 attenuates the biosynthesis of the potent 11-oxygenated androgen, 11-ketotestosterone (11KT), by AKR1C3. Employing ex vivo incubations of human female adipose tissue samples we show that inhibition of HSD11B1 results in the increased peripheral biosynthesis of 11KT. Moreover, circulating 11KT increased 2-3 fold in individuals with type 2 diabetes after receiving the selective oral HSD11B1 inhibitor AZD4017 for 35 days, thus confirming that HSD11B1 inhibition results in systemic increases in 11KT concentrations. Our findings show that HSD11B1 protects against excess 11KT production by adipose tissue, a finding of particular significance when considering the evidence for adverse metabolic effects of androgens in women. Therefore, when targeting glucocorticoid activation by HSD11B1 inhibitor treatment in women, the consequently increased generation of 11KT may offset beneficial effects of decreased glucocorticoid activation.

JTT-654, an 11-beta hydroxysteroid dehydrogenase type 1 inhibitor, improves hypertension and diabetic kidney injury by suppressing angiotensinogen production

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) plays an important role in regulating the expression of glucocorticoid actions in target tissues. Overexpression of 11β-HSD1 in mouse adipose tissue causes a metabolic syndrome-like phenotype, leading to hypertension. Although, many 11β-HSD1 inhibitors have been studied, few have shown a clear ameliorative effect against hypertension. We investigated whether JTT-654, a novel 11β-HSD1 inhibitor, ameliorated hypertension and elucidated the underlying mechanisms. JTT-654 showed inhibitory effects on angiotensinogen production in cortisone-treated 3T3-L1 adipocytes and in a rat model. JTT-654 improved hypertension not only in cortisone-treated rats and spontaneously hypertensive rats (SHR), but also in SHR/NDmcr-cp rats. In the SHR study, JTT-654 and losartan showed the same degree of antihypertensive efficacy. In addition, JTT-654 ameliorated diabetic nephropathy by suppressing renal angiotensinogen production in SHR/NDmcr-cp rats. These effects of JTT-654 were independent of its insulin-sensitizing effects, and similar effects were not observed for pioglitazone, an insulin sensitizer. Moreover, JTT-654 did not affect normotension or hypothalamus-pituitary-adrenal (HPA) axis function in normal Sprague-Dawley rats. Our results indicate that JTT-654 ameliorates hypertension and diabetic nephropathy by inhibiting 11β-HSD1 in the adipose tissue, liver, and kidney.

11β-Hydroxysteroid dehydrogenase and the brain: Not (yet) lost in translation

11-beta-hydroxysteroid dehydrogenases (11β-HSDs) catalyse the conversion of active 11-hydroxy glucocorticoids (cortisol, corticosterone) and their inert 11-keto forms (cortisone, 11-dehydrocorticosterone). They were first reported in the body and brain 70 years ago, but only recently have they become of interest. 11β-HSD2 is a dehydrogenase, potently inactivating glucocorticoids. In the kidney, 11β-HSD2 generates the aldosterone-specificity of intrinsically non-selective mineralocorticoid receptors. 11β-HSD2 also protects the developing foetal brain and body from premature glucocorticoid exposure, which otherwise engenders the programming of neuropsychiatric and cardio-metabolic disease risks. In the adult CNS, 11β-HSD2 is confined to a part of the brain stem where it generates aldosterone-specific central control of salt appetite and perhaps blood pressure. 11β-HSD1 is a reductase, amplifying active glucocorticoid levels within brain cells, notably in the cortex, hippocampus and amygdala, paralleling its metabolic functions in peripheral tissues. 11β-HSD1 is elevated in the ageing rodent and, less certainly, human forebrain. Transgenic models show this rise contributes to age-related cognitive decline, at least in mice. 11β-HSD1 inhibition robustly improves memory in healthy and pathological ageing rodent models and is showing initial promising results in phase II studies of healthy elderly people. Larger trials are needed to confirm and clarify the magnitude of effect and define target populations. The next decade will be crucial in determining how this tale ends - in new treatments or disappointment.

First in human randomised trial of J2H-1702: A novel 11β-hydroxysteroid dehydrogenase type 1 inhibitor for non-alcoholic steatohepatitis treatment

BACKGROUND

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which is an enzyme that converts cortisone to cortisol, plays a role in the regulation of glucose metabolism and inflammation. J2H-1702 is a novel 11β-HSD1 inhibitor, and the inhibition of 11β-HSD1 has been shown to improve insulin sensitivity, reduce inflammation, and prevent the development of nonalcoholic steatohepatitis (NASH) in preclinical models.

AIMS

We aimed to assess the pharmacokinetics (PKs), pharmacodynamics (PDs), safety, and tolerability of J2H-1702 after a single-dose oral administration.

METHODS

A randomised, double-blinded, placebo-controlled, single-dose, dose-escalation study was conducted on 50 healthy volunteers. Blood and urine samples were collected to assess the PK and PD of J2H-1702.

RESULTS

The peak plasma concentration of J2H-1702 was observed at 2-2.9 h after a single-dose oral administration. J2H-1702 reduced 11β-HSD1 activity compared to the placebo at all dose levels. The drug reached its maximal inhibitory effect within 12-24 h post-dose administration, and the inhibitory effect was maintained till 1 day after administration of the study drug. The drug showed typical first-order elimination kinetics, with a mean elimination half-life of 9.8-14.7 h. Systemic exposure to J2H-1702 increased in a dose-dependent manner. J2H-1702 was well tolerated after a single oral administration of up to 300 mg. A total of 11 treatment-emergent adverse events (TEAEs) occurred in seven (14%) participants, all of which were mild and resolved spontaneously. The most common TEAE was diarrhoea (8%), followed by dizziness (4%).

CONCLUSIONS

The results of this study suggest that J2H-1702 could be developed as an effective therapeutic option for NASH.

Review of triazole scaffolds for treatment and diagnosis of Alzheimer's disease

Triazole scaffolds, a series of 5-membered heterocycles, are well known for their high efficacy, low toxicity, and superior pharmacokinetics. Alzheimer's disease (AD) is the first neurodegenerative disorder with complex pathological mechanisms. Triazole, as an aromatic group with three nitrogen atoms, forms polar and non-polar interactions with diverse key residues in the receptor-ligand binding procedure, and has been widely used in the molecular design in the development of anti-AD agents. Moreover, considering the simple synthesis approaches, triazole scaffolds are commonly used to link two pharmacodynamic groups in one chemical molecule, forming multi-target directed ligands (MTDLs). Furthermore, the click reaction between azide- and cyano-modified enzyme and ligand provides feasibility for the new modulator discovery, compound tissue distribution evaluation, enzyme localization, and pharmacological mechanism study, promoting the diagnosis of AD course.

High salt intake activates the hypothalamic-pituitary-adrenal axis, amplifies the stress response, and alters tissue glucocorticoid exposure in mice

AIMS

High salt intake is common and contributes to poor cardiovascular health. Urinary sodium excretion correlates directly with glucocorticoid excretion in humans and experimental animals. We hypothesized that high salt intake activates the hypothalamic-pituitary-adrenal axis activation and leads to sustained glucocorticoid excess.

METHODS AND RESULTS

In male C57BL/6 mice, high salt intake for 2-8 weeks caused an increase in diurnal peak levels of plasma corticosterone. After 2 weeks, high salt increased Crh and Pomc mRNA abundance in the hypothalamus and anterior pituitary, consistent with basal hypothalamic-pituitary-adrenal axis activation. Additionally, high salt intake amplified glucocorticoid response to restraint stress, indicative of enhanced axis sensitivity. The binding capacity of Corticosteroid-Binding Globulin was reduced and its encoding mRNA downregulated in the liver. In the hippocampus and anterior pituitary, Fkbp5 mRNA levels were increased, indicating increased glucocorticoid exposure. The mRNA expression of the glucocorticoid-regenerating enzyme, 11β-hydroxysteroid dehydrogenase Type 1, was increased in these brain areas and in the liver. Sustained high salt intake activated a water conservation response by the kidney, increasing plasma levels of the vasopressin surrogate, copeptin. Increased mRNA abundance of Tonebp and Avpr1b in the anterior pituitary suggested that vasopressin signalling contributes to hypothalamic-pituitary-adrenal axis activation by high salt diet.

CONCLUSION

Chronic high salt intake amplifies basal and stress-induced glucocorticoid levels and resets glucocorticoid biology centrally, peripherally and within cells.

An 11-Beta Hydroxysteroid Dehydrogenase Type 1 Inhibitor, JTT-654 Ameliorates Insulin Resistance and Non-obese Type 2 Diabetes

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is the only enzyme that converts inactive glucocorticoids to active forms and plays an important role in the regulation of glucocorticoid action in target tissues. JTT-654 is a selective 11β-HSD1 inhibitor and we investigated its pharmacological properties in cortisone-treated rats and non-obese type 2 diabetic Goto-Kakizaki (GK) rats because Asians, including Japanese, are more likely to have non-obese type 2 diabetics. Systemic cortisone treatment increased fasting plasma glucose and insulin levels and impaired insulin action on glucose disposal rate and hepatic glucose production assessed by hyperinsulinemic-euglycemic clamp, but all these effects were attenuated by JTT-654 administration. Cortisone treatment also reduced basal and insulin-stimulated glucose oxidation in adipose tissue, increased plasma glucose levels after administration of the pyruvate, the substrate of gluconeogenesis, and increased liver glycogen content. Administration of JTT-654 also inhibited all of these effects. Cortisone treatment decreased basal and insulin-stimulated 2-deoxy-D-[1-³H]-glucose uptake in 3T3-L1 adipocytes and increased the release of free fatty acids and glycerol, a gluconeogenic substrate, from 3T3-L1 adipocytes, and JTT-654 significantly attenuated these effects. In GK rats, JTT-654 treatment significantly reduced fasting plasma glucose and insulin levels, enhanced insulin-stimulated glucose oxidation in adipose tissue, and suppressed hepatic gluconeogenesis as assessed by pyruvate administration. These results demonstrated that glucocorticoid was involved in the pathology of diabetes in GK rats, as in cortisone-treated rats, and that JTT-654 ameliorated the diabetic conditions. Our results suggest that JTT-654 ameliorates insulin resistance and non-obese type 2 diabetes by inhibiting adipose tissue and liver 11β-HSD1.

Development and structure-activity relationships of tanshinones as selective 11β-hydroxysteroid dehydrogenase 1 inhibitors

11β-Hydroxysteroid dehydrogenase 1 (11β-HSD1) represents a promising drug target for metabolic syndrome, including obesity and type 2 diabetes. Our initial screen of a collection of natural products from Danshen led to the identification of tanshinones as the potent and selective 11β-HSD1 inhibitors. To improve the druggability and explore the structure-activity relationships (SARs), more than 40 derivatives have been designed and synthesized using tanshinone IIA and cryptotanshinone as the starting materials. More than 10 derivatives exhibited potent in vitro 11β-HSD1 inhibitory activity and good selectivity over 11β-HSD2 across human and mouse species. Based on the biological results, SARs were further discussed, which was also partially rationalized by a molecular docking model of 1 bound to the 11β-HSD1. Remarkably, compounds 1, 17 and 30 significantly inhibited 11β-HSD1 in 3T3-L1 adipocyte and in livers of ob/ob mice, which merits further investigations as anti-diabetic agents. This study not only provides a series of novel selective 11β-HSD1 inhibitors with promising therapeutic potentials in metabolic syndromes, but also expands the boundaries of the chemical and biological spaces of tanshinones.

Discovery of 1'-(1-phenylcyclopropane-carbonyl)-3H-spiro[isobenzofuran-1,3'-pyrrolidin]-3-one as a novel steroid mimetic scaffold for the potent and tissue-specific inhibition of 11β-HSD1 using a scaffold-hopping approach

11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) has been identified as the primary enzyme responsible for the activation of hepatic cortisone to cortisol in specific peripheral tissues resulting in the concomitant antagonism of insulin action within these tissues. Dysregulation of 11β-HSD1, particularly in adipose tissues, has been associated with metabolic syndrome and type 2 diabetes mellitus. Therefore, inhibition of 11β-HSD1 with a small nonsteroidal molecule is therapeutically desirable. Implementation of a scaffold-hopping approach revealed a three-point pharmacophore for 11β-HSD1 that was utilized to design a steroid mimetic scaffold. Reiterative optimization provided valuable insight into the bioactive conformation of our novel scaffold and led to the discovery of INCB13739. Clinical evaluation of INCB13739 confirmed for the first time that tissue-specific inhibition of 11β-HSD1 in patients with type 2 diabetes mellitus was efficacious in controlling glucose levels and reducing cardiovascular risk factors.

Discovery of a novel 2-spiroproline steroid mimetic scaffold for the potent inhibition of 11β-HSD1

11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) has been identified as the primary enzyme responsible for the activation of hepatic cortisone to cortisol in specific peripheral tissues, resulting in the concomitant antagonism of insulin action within these tissues. Dysregulation of 11β-HSD1, particularly in adipose tissues, has been associated with a variety of ailments including metabolic syndrome and type 2 diabetes mellitus. Therefore, inhibition of 11β-HSD1 with a small nonsteroidal molecule is therapeutically desirable. Implementation of a scaffold-hopping approach revealed a 3-point pharmacophore for 11β-HSD1 that was utilized to design a 2-spiroproline derivative as a steroid mimetic scaffold. Reiterative optimization provided valuable insight into the bioactive conformation of our novel scaffold and led to the discovery of several leads, such as compounds 39 and 51. Importantly, deleterious hERG inhibition and pregnane X receptor induction were mitigated by the introduction of a 4-hydroxyl group to the proline ring system.

An Open-label Phase I/IIa Clinical Trial of 11β-HSD1 Inhibitor for Cushing's Syndrome and Autonomous Cortisol Secretion

CONTEXT

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors demonstrate antimetabolic and antisarcopenic effects in Cushing's syndrome (CS) and autonomous cortisol secretion (ACS) patients.

OBJECTIVE

To confirm the efficacy and safety of S-707106 (11β-HSD1 inhibitor) administered to CS and ACS patients.

DESIGN

A 24-week single-center, open-label, single-arm, dose-escalation, investigator-initiated clinical trial on a database.

SETTING

Kyushu University Hospital, Kurume University Hospital, and related facilities.

PATIENTS

Sixteen patients with inoperable or recurrent CS and ACS, with mildly impaired glucose tolerance.

INTERVENTION

Oral administration of 200 mg S-707106 after dinner, daily, for 24 weeks. In patients with insufficient improvement in oral glucose tolerance test results at 12 weeks, an escalated dose of S-707106 (200 mg twice daily) was administered for the residual 12 weeks.

MAIN OUTCOME MEASURES

The rate of participants responding to glucose tolerance impairment, defined as those showing a 25% reduction in the area under the curve (AUC) of plasma glucose during the 75-g oral glucose tolerance test at 24 weeks.

RESULTS

S-707106 administration could not achieve the primary endpoint of this clinical trial (>20% of responsive participants). AUC glucose decreased by -7.1% [SD, 14.8 (90% CI -14.8 to -1.0), P = 0.033] and -2.7% [14.5 (-10.2 to 3.4), P = 0.18] at 12 and 24 weeks, respectively. S-707106 administration decreased AUC glucose significantly in participants with a high body mass index. Body fat percentage decreased by -2.5% [1.7 (-3.3 to -1.8), P < 0.001] and body muscle percentage increased by 2.4% [1.6 (1.7 to 3.1), P < 0.001].

CONCLUSIONS

S-707106 is an effective insulin sensitizer and antisarcopenic and antiobesity medication for these patients.

Calcium-Deficiency during Pregnancy Affects Insulin Resistance in Offspring

Prenatal malnutrition is known to affect the phenotype of the offspring through changes in epigenetic regulation. Growing evidence suggests that epigenetics is one of the mechanisms by which nutrients and minerals affect metabolic traits. Although the perinatal period is the time of highest phenotypic plasticity, which contributes largely to developmental programming, there is evidence of nutritional influence on epigenetic regulation during adulthood. Calcium (Ca) plays an important role in the pathogenesis of insulin resistance syndrome. Cortisol, the most important glucocorticoid, is considered to lead to insulin resistance and metabolic syndrome. 11β-hydroxysteroid dehydrogenase-1 is a key enzyme that catalyzes the intracellular conversion of cortisone to physiologically active cortisol. This brief review aims to identify the effects of Ca deficiency during pregnancy and/or lactation on insulin resistance in the offspring. Those findings demonstrate that maternal Ca deficiency during pregnancy may affect the epigenetic regulation of gene expression and thereby induce different metabolic phenotypes. We aim to address the need for Ca during pregnancy and propose the scaling-up of clinical and public health approaches that improved pregnancy outcomes.

11β-hydroxysteroid dehydrogenases: A growing multi-tasking family

This review briefly addresses the history of the discovery and elucidation of the three cloned 11β-hydroxysteroid dehydrogenase (11βHSD) enzymes in the human, 11βHSD1, 11βHSD2 and 11βHSD3, an NADP⁺-dependent dehydrogenase also called the 11βHSD1-like dehydrogenase (11βHSD1L), as well as evidence for yet identified 11βHSDs. Attention is devoted to more recently described aspects of this multi-functional family. The importance of 11βHSD substrates other than glucocorticoids including bile acids, 7-keto sterols, neurosteroids, and xenobiotics is discussed, along with examples of pathology when functions of these multi-tasking enzymes are disrupted. 11βHSDs modulate the intracellular concentration of glucocorticoids, thereby regulating the activation of the glucocorticoid and mineralocorticoid receptors, and 7β-27-hydroxycholesterol, an agonist of the retinoid-related orphan receptor gamma (RORγ). Key functions of this nuclear transcription factor include regulation of immune cell differentiation, cytokine production and inflammation at the cell level. 11βHSD1 expression and/or glucocorticoid reductase activity are inappropriately increased with age and in obesity and metabolic syndrome (MetS). Potential causes for disappointing results of the clinical trials of selective inhibitors of 11βHSD1 in the treatment of these disorders are discussed, as well as the potential for more targeted use of inhibitors of 11βHSD1 and 11βHSD2.

Structure-based molecular modeling in SAR analysis and lead optimization

In silico methods like molecular docking and pharmacophore modeling are established strategies in lead identification. Their successful application for finding new active molecules for a target is reported by a plethora of studies. However, once a potential lead is identified, lead optimization, with the focus on improving potency, selectivity, or pharmacokinetic parameters of a parent compound, is a much more complex task. Even though in silico molecular modeling methods could contribute a lot of time and cost-saving by rationally filtering synthetic optimization options, they are employed less widely in this stage of research. In this review, we highlight studies that have successfully used computer-aided SAR analysis in lead optimization and want to showcase sound methodology and easily accessible in silico tools for this purpose.

Adipose Tissue and Endocrine-Disrupting Chemicals: Does Sex Matter?

Obesity and metabolic-related diseases, among which diabetes, are prominent public health challenges of the 21st century. It is now well acknowledged that pollutants are a part of the equation, especially endocrine-disrupting chemicals (EDCs) that interfere with the hormonal aspect. The aim of the review is to focus on adipose tissue, a central regulator of energy balance and metabolic homeostasis, and to highlight the significant differences in the endocrine and metabolic aspects of adipose tissue between males and females which likely underlie the differences of the response to exposure to EDCs between the sexes. Moreover, the study also presents an overview of several mechanisms of action by which pollutants could cause adipose tissue dysfunction. Indeed, a better understanding of the mechanism by which environmental chemicals target adipose tissue and cause metabolic disturbances, and how these mechanisms interact and sex specificities are essential for developing mitigating and sex-specific strategies against metabolic diseases of chemical origin. In particular, considering that a scenario without pollutant exposure is not a realistic option in our current societies, attenuating the deleterious effects of exposure to pollutants by acting on the gut-adipose tissue axis may constitute a new direction of research.

Maternal separation-induced increases in vascular stiffness are independent of circulating angiotensinogen levels

The renin-angiotensin system (RAS) precursor angiotensinogen (AGT) has been implicated in the functional and mechanical alterations of the vascular wall in response to high-fat diet (HFD). Previously, we showed that HFD exacerbates angiotensin II-induced constriction in isolated aortic rings from male rats exposed to maternal separation (MatSep), a model of early-life stress. Thus, the aim of this study was to investigate whether MatSep increases AGT secretion promoting vascular stiffness in rats fed a HFD. Male Wistar-Kyoto MatSep offspring were separated (3 h/day, postnatal days 2-14), and undisturbed littermates were used as controls. At weaning, rats were fed for 17 wk a normal diet (ND) or a HFD, 18% or 60% kcal from fat, respectively. In plasma, there was a main effect of MatSep reducing AGT concentration (P < 0.05) but no effect due to diet. In urine, ND-fed MatSep rats displayed higher AGT concentrations that were further increased by HFD (P < 0.05 vs. control). AGT mRNA abundance and protein expression were increased in adipose tissue from HFD-fed MatSep rats compared with control rats (P < 0.05). No significant differences in liver and kidney AGT levels were found between groups. In addition, MatSep augmented vascular stiffness assessed on freshly isolated aortic rings from ND-fed rats (P < 0.05), yet HFD did not worsen vascular stiffness in either MatSep or control rats. There was no correlation between plasma AGT and vascular stiffness in ND-fed rats; however, this relationship was negative in HFD-fed MatSep rats only (P < 0.05). Therefore, this study shows that MatSep-induced increases in vascular stiffness are independent of diet or plasma AGT.NEW & NOTEWORTHY This study demonstrates that there was no correlation between circulating levels of angiotensinogen (AGT) and the development of vascular stiffness in rats exposed to early-life stress and fed a normal diet. This study also shows that early-life stress-induced hypersensitive vascular contractility to angiotensin II in rats fed a high-fat diet is independent of circulating levels of AGT and occurs without further progression of vascular stiffness. Our data show that early-life stress primes the adipose tissue to secrete AGT in a sex- and species-independent fashion.

Alpha2B-Adrenergic Receptor Overexpression in the Brain Potentiate Air Pollution-induced Behavior and Blood Pressure Changes

Fine ambient particulate matter (PM2.5) is able to induce sympathetic activation and inflammation in the brain. However, direct evidence demonstrating an essential role of sympathetic activation in PM2.5-associated disease progression is lacking. We assess the contribution of α2B-adrenergic receptor (Adra2b) in air pollution-associated hypertension and behavioral changes in this study. Wild-type mice and Adra2b-transgenic mice overexpressing Adra2b in the brain (Adra2bTg) were exposed to concentrated PM2.5 or filtered air for 3 months via a versatile aerosol concentrator exposure system. Mice were fed with a high salt diet (4.0% NaCl) for 1 week at week 11 of exposure to induce blood pressure elevation. Intra-arterial blood pressure was monitored by radio-telemetry and behavior changes were assessed by open field, light-dark, and prepulse inhibition tests. PM2.5 exposure increased Adra2b in the brain of wild-type mice. Adra2b overexpression enhanced the anxiety-like behavior and high salt diet-induced blood pressure elevation in response to air pollution but not filtered air exposure. Adra2b overexpression induced upregulation of inflammatory genes such as TLR2, TLR4, and IL-6 in the brain exposed to PM2.5. In addition, there were increased frequencies of activated effector T cells and increased expression of oxidative stress-related genes, such as SOD1, NQO1, Nrf2, and Gclm in Adra2bTg mice compared with wild-type mice. Our results provide new evidence of distinct behavioral changes consistent with anxiety and blood pressure elevation in response to high salt intake and air pollution exposure, highlighting the importance of centrally expressed Adra2b in the vulnerability to air pollution exposure.

Role of Mineralocorticoid Receptor in Adipogenesis and Obesity in Male Mice

Increased visceral adiposity and hyperglycemia, 2 characteristics of metabolic syndrome, are also present in conditions of excess glucocorticoids (GCs). GCs are hormones thought to act primarily via the glucocorticoid receptor (GR). GCs are commonly prescribed for inflammatory disorders, yet their use is limited due to many adverse metabolic side effects. In addition to GR, GCs also bind the mineralocorticoid receptor (MR), but there are many conflicting studies about the exact role of MR in metabolic disease. Using MR knockout mice (MRKO), we find that both white and brown adipose depots form normally when compared with wild-type mice at P5. We created mice with adipocyte-specific deletion of MR (FMRKO) to better understand the role of MR in metabolic dysfunction. Treatment of mice with excess GCs for 4 weeks, via corticosterone in drinking water, induced increased fat mass and glucose intolerance to similar levels in FMRKO and floxed control mice. Separately, when fed a high-fat diet for 16 weeks, FMRKO mice had reduced body weight, fat mass, and hepatic steatosis, relative to floxed control mice. Decreased adiposity likely resulted from increased energy expenditure since food intake was not different. RNA sequencing analysis revealed decreased enrichment of genes associated with adipogenesis in inguinal white adipose of FMRKO mice. Differentiation of mouse embryonic fibroblasts (MEFs) showed modestly impaired adipogenesis in MRKO MEFs compared with wild type, but this was rescued upon the addition of peroxisome proliferator-activated receptor gamma (PPARγ) agonist or PPARγ overexpression. Collectively, these studies provide further evidence supporting the potential value of MR as a therapeutic target for conditions associated with metabolic syndrome.

Early weaning leads to specific glucocorticoid signalling in fat depots of adult rats

PURPOSE

Early weaning (EW) is a stressful condition that programmes a child to be overweight in adult life. Fat mass depends on glucocorticoids (GC) to regulate adipogenesis and lipogenesis. We hypothesised that the increased adiposity in models of EW was due to a disturbed HPA axis and/or disrupted GC function.

METHODS

We used two experimental models, pharmacological early weaning (PEW, dams were bromocriptine-treated) and non-pharmacological early weaning (NPEW, dams' teats were wrapped with a bandage), which were initiated during the last 3 days of lactation. Offspring from both genders was analysed on postnatal day 180.

RESULTS

Offspring in both models were overweight with increased visceral fat mass, but plasma corticosterone was increased in both genders in the PEW group but not the NPEW group. NPEW males had increased GRα expression in visceral adipose tissue (VAT), and GRα expression decreased in PEW males in subcutaneous adipose tissue (SAT). Females in both EW groups had increased 11βHSD1 expression in SAT. PEW males had increased C/EBPβ expression in SAT. PEW females had lower PPARy and FAS expression in VAT than the NPEW females. We detected a sex dimorphism in VAT and SAT in the EW groups regarding 11βHSD1, GRα and C/EBPβ expression.

CONCLUSIONS

The accumulated adiposity induced by EW exhibited distinct mechanisms depending on gender, specific fat deposition and GC metabolism and action. The higher proportion of VAT/SAT in both sets of EW males may be related to the action of GC in these tissues, and the higher conversion of GC in SAT in females may explain the differences in the fat distribution.

A Novel 18F-Labeled Radioligand for Positron Emission Tomography Imaging of 11β-Hydroxysteroid Dehydrogenase (11β-HSD1): Synthesis and Preliminary Evaluation in Nonhuman Primates

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the conversion of cortisone to cortisol and controls a key pathway in the regulation of stress. Studies have implicated 11β-HSD1 in metabolic diseases including type 2 diabetes and obesity, as well as stress-related disorders and neurodegenerative diseases, such as depression and Alzheimer's disease (AD). We have previously developed [¹¹C]AS2471907 as a PET radiotracer to image 11β-HSD1 in the brain of nonhuman primates and humans. However, the radiosynthesis of [¹¹C]AS2471907 was unreliable and low-yielding. Here, we report the development of the ¹⁸F-labeled version [¹⁸F]AS2471907, including the synthesis of two iodonium ylide precursors and the optimization of ¹⁸F-radiosynthesis. Preliminary PET experiments, composed of a baseline scan of [¹⁸F]AS2471907 and a blocking scan with the reversible 11β-HSD1 inhibitor ASP3662 (0.3 mg/kg), was also conducted in a rhesus monkey to verify the pharmacokinetics of [¹⁸F]AS2471907 and its specific binding in the brain. The iodonium ylide precursors were prepared in a seven-step synthetic route with an optimized overall yield of ∼2%. [¹⁸F]AS2471907 was synthesized in good radiochemical purity, with the ortho regioisomer of iodonium ylide providing greater radiochemical yield as compared with the para regioisomer. In monkey brain, [¹⁸F]AS2471907 displayed high uptake and heterogeneous distribution, while administration of the 11β-HSD1 inhibitor ASP3662 significantly reduced radiotracer uptake, thus demonstrating the binding specificity of [¹⁸F]AS2471907. Given the longer half-life of F-18 and feasibility for central production and distribution, [¹⁸F]AS2471907 holds great promise to be a valuable PET radiotracer to image 11β-HSD1 in the brain.

Ectopic lipid deposition mediates insulin resistance in adipose specific 11β-hydroxysteroid dehydrogenase type 1 transgenic mice

CONTEXT

Excessive adipose glucocorticoid action is associated with insulin resistance, but the mechanisms linking adipose glucocorticoid action to insulin resistance are still debated. We hypothesized that insulin resistance from excess glucocorticoid action may be attributed in part to increased ectopic lipid deposition in liver.

METHODS

We tested this hypothesis in the adipose specific 11β-hydroxysteroid dehydrogenase-1 (HSD11B1) transgenic mouse, an established model of adipose glucocorticoid excess. Tissue specific insulin action was assessed by hyperinsulinemic-euglycemic clamps, hepatic lipid content was measured, hepatic insulin signaling was assessed by immunoblotting. The role of hepatic lipid content was further probed by administration of the functionally liver-targeted mitochondrial uncoupler, Controlled Release Mitochondrial Protonophore (CRMP).

FINDINGS

High fat diet fed HSD11B1 transgenic mice developed more severe hepatic insulin resistance than littermate controls (endogenous suppression of hepatic glucose production was reduced by 3.8-fold, P < 0.05); this was reflected by decreased insulin-stimulated hepatic insulin receptor kinase tyrosine phosphorylation and AKT serine phosphorylation. Hepatic insulin resistance was associated with a 53% increase (P < 0.05) in hepatic triglyceride content, a 73% increase in diacylglycerol content (P < 0.01), and a 66% increase in PKCε translocation (P < 0.05). Hepatic insulin resistance was prevented with administration of CRMP by reversal of hepatic steatosis and prevention of hepatic diacylglycerol accumulation and PKCε activation.

CONCLUSIONS

These findings are consistent with excess adipose glucocorticoid activity being a predisposing factor for the development of lipid (diacylglycerol-PKCε)-induced hepatic insulin resistance.

Expression and activity of the cortisol-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 is tissue and species-specific

The microsomal enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) interconverts glucocorticoid receptor-inert cortisone (11-dehydrocorticosterone in rodents) to its receptor-active form cortisol (corticosterone in rodents). Thus, 11β-HSD1 amplifies glucocorticoid action at the tissue level. According to the current literature, dysregulation of glucocorticoid signaling may contribute to the pathogenesis of the metabolic syndrome in which regeneration of cortisol by 11β-HSD1 may be an important factor. This is why the enzyme has been very intensely investigated as a potential therapeutic target to treat metabolic complications such as obesity and diabetes type 2. However, due to controversial results from the various animal and human studies as well as from different findings with regard to tissue-specific expression and activity, the varied results unfortunately do not yield a consistent picture. Therefore, the precise role of 11β-HSD1 in the development of complications associated with the metabolic syndrome has still not been deciphered yet. Overall, the prominent role of this enzyme in the pathogenesis of the metabolic syndrome becomes more and more dubious and therefore further studies are necessary to clarify its role finally. This short review gives an overview on the main contradicting findings on the role of 11β-HSD1 in the development of visceral obesity and diabetes type 2.

11β Hydroxysteroid dehydrogenase - 1 activity in type 2 diabetes mellitus: a comparative study

BACKGROUND

A comparative study of 11 β HSD 1 activity in type 2 diabetes mellitus subjects with respect to fasting blood glucose and other metabolic parameters was conducted.

METHODS

A case control experimental study was performed enrolling thirty type 2 diabetes mellitus patients and thirty age, gender and BMI matched controls using cortisone acetate test.

RESULTS

The rise of serum cortisol after oral 25 mg cortisone acetate from baseline (dexamethasone suppressed level) is higher in subjects with type 2 diabetes and is associated with exercise, BMI, SGOT but not daily calorie intake, lipid parameters and thyroid status. Fasting blood glucose after overnight 1 mg oral dexamethasone is a strong predictor of 11HSD1 activity, irrespective of presence of type 2 diabetes.

CONCLUSION

11β HSD 1 activity is higher in type 2 diabetes mellitus subjects, especially those who are lean. Future 11 β HSD 1 inhibitors targeting metabolic syndrome, will be most useful in those with increased fasting blood glucose. The role of DHEAS and vitamin D status needs to be explored.

Minor role of mature adipocyte mineralocorticoid receptor in high-fat diet-induced obesity

Obesity is a major risk factor that contributes to the development of cardiovascular disease and type 2 diabetes. Mineralocorticoid receptor (MR) expression is increased in the adipose tissue of obese patients and several studies provide evidence that MR pharmacological antagonism improves glucose metabolism in genetic and diet-induced mouse models of obesity. In order to investigate whether the lack of adipocyte MR is sufficient to explain these beneficial metabolic effects, we generated a mouse model with inducible adipocyte-specific deletion of Nr3c2 gene encoding MR (adipo-MRKO). We observed a significant, yet not complete, reduction of Nr3c2 transcript and MR protein expression in subcutaneous and visceral adipose depots of adipo-MRKO mice. Notably, only mature adipocyte fraction lacks MR, whereas the stromal vascular fraction maintains normal MR expression in our mouse model. Adipo-MRKO mice fed a 45% high-fat diet for 14 weeks did not show any significant difference in body weight and fat mass compared to control littermates. Glucose and insulin tolerance tests revealed that mature adipocyte MR deficiency did not improve insulin sensitivity in response to a metabolic homeostatic challenge. Accordingly, no significant changes were observed in gene expression profile of adipogenic and inflammatory markers in adipose tissue of adipo-MRKO mice. Moreover, pharmacological MR antagonism in mature primary murine adipocytes, which differentiated ex vivo from WT mice, did not display any effect on adipokine expression. Taken together, these data demonstrate that the depletion of MR in mature adipocytes displays a minor role in diet-induced obesity and metabolic dysfunctions.

Pentacyclic Triterpenes from Cecropia telenitida Can Function as Inhibitors of 11β-Hydroxysteroid Dehydrogenase Type 1

Plant extracts from the genus Cecropia have been used by Latin-American traditional medicine to treat metabolic disorders and diabetes. Previous results have shown that roots of Cecropia telenitida contain pentacyclic triterpenes and these molecules display a hypoglycemic effect in an insulin-resistant murine model. The pharmacological target of these molecules, however, remains unknown. Several lines of evidence indicate that pentacyclic triterpenes inhibit the 11β-hydroxysteroid dehydrogenase type 1 enzyme, which highlights the potential use of this type of natural product as phytotherapeutic or botanical dietary supplements. The main goal of the study was the evaluation of the inhibitory effect of Cecropia telenitida molecules on 11β-hydroxysteroid dehydrogenase type 1 enzyme activity. A pre-fractionated chemical library was obtained from the roots of Cecropia telenitida using several automated chromatography separation steps and a homogeneous time resolved fluorescence assay was used for the bio-guided isolation of inhibiting molecules. The screening of a chemical library consisting of 125 chemical purified fractions obtained from Cecropia telenitida roots identified one fraction displaying 82% inhibition of the formation of cortisol by the 11β-hydroxysteroid dehydrogenase type 1 enzyme. Furthermore, a molecule displaying IC₅₀ of 0.95 ± 0.09 µM was isolated from this purified fraction and structurally characterized, which confirms that a pentacyclic triterpene scaffold was responsible for the observed inhibition. Our results support the hypothesis that pentacyclic triterpene molecules from Cecropia telenitida can inhibit 11β-hydroxysteroid dehydrogenase type 1 enzyme activity. These findings highlight the potential ethnopharmacological use of plants from the genus Cecropia for the treatment of metabolic disorders and diabetes.

Exploring N-acyl-4-azatetracyclo[5.3.2.02,6.08,10]dodec-11-enes as 11β-HSD1 Inhibitors

We recently found that a cyclohexanecarboxamide derived from 4-azatetracyclo[5.3.2.0^2,6.0^8,10]dodec-11-ene displayed low nanomolar inhibition of 11β-HSD1. In continuation of our efforts to discover potent and selective 11β-HSD1 inhibitors, herein we explored several replacements for the cyclohexane ring. Some derivatives exhibited potent inhibitory activity against human 11β-HSD1, although with low selectivity over the isoenzyme 11β-HSD2, and poor microsomal stability.

Fructose-induced inflammation and increased cortisol: A new mechanism for how sugar induces visceral adiposity

Traditionally, the leading hypothesis regarding the development of obesity involves caloric imbalance, whereby the amount of calories consumed exceeds the amount of calories burned which causes obesity. Another hypothesis for why we get fat has surfaced in the last decade which is the idea that the overconsumption of added sugars and refined carbohydrates induce insulin resistance and high insulin levels causing obesity. While insulin is a fat-storing hormone, this hypothesis does not explain visceral adiposity, or why certain people are found to have fat stored in and around their organs. We propose a new mechanism for body fattening, particular visceral adiposity. This hypothesis involves the overconsumption of fructose, which leads to inflammation in all cells that metabolize it rapidly. When fructose is metabolized in subcutaneous adipocytes, the subsequent inflammation leads to an increase in intracellular cortisol in order to help squelch the inflammation. Unfortunately, the increase in intracellular cortisol leads to an increased flux of fatty acids out of the subcutaneous adipocytes allowing more substrate for fat storage into visceral fat tissue. Moreover fructose-induced inflammation in the liver also leads to increased intracellular cortisol via an upregulation of 11-B hydroxysteroid dehydrogenase type 1 causing increased fat storage in the liver (i.e., fatty liver). In essence, the fructose-induced inflammatory cortisol response causes "thin on the outside, fat on the inside" (TOFI). Furthermore, fructose in the brain, either from fructose uptake via the blood brain barrier or endogenous formation from glucose via the polyol pathway stimulates an increased release of cortisol causing hepatic gluconeogenesis leading to overall insulin resistance and further body fattening. This review paper will discuss in detail the hypothesis that fructose-induced inflammation and cortisol activation causes visceral adiposity.

Glucocorticoid treatment facilitates development of a metabolic syndrome in ovariectomized Macaca Mulatta fed a high fat diet

Metabolic syndrome (MetS) is characterized by a cluster of key features, which include abdominal obesity, insulin resistance, hypertension, and dyslipidemia. The aim of this study was to assess the impact of elevated glucocorticoid levels on the development of MetS in middle-aged female rhesus monkeys (Macaca Mulatta) after ovariectomy. Six female ovariectomized rhesus monkeys (9-13years) were randomly assigned to either a control group (normal diet, n=3) or a group in which MetS was facilitated (n=3). The MetS group fed with HFD (15% fat) and received oral prednisone acetate treatment (50mg/day). After 24months, the GCs treatment was withdrawn with continuation of high-fat feeding for a further 12months. After 24months, the MetS group displayed a significant increase in body weight and abdominal circumference. Additionally, the MetS animals displayed abnormal serum lipids, insulin resistance and impaired glucose tolerance. Histology of liver biopsies indicated marked accumulation of lipid droplets in hepatocytes of MetS animals. Withdrawal of GCs treatment led to recovery from above-mentioned metabolic disorders. Whereas GCs treatment increased leptin expression, it lowered expression of adiponectin and other factors in adipose tissue. Expression of Hydroxy-steroid dehydrogenase-1 and glucose transporter type-4 in the livers of MetS animals were reduced. We conclude that in the context of high fat diet, high levels of exogenous GCs contribute to the development of MetS in non-human primates.

11β-Hydroxysteroid Dehydrogenases and Hypertension in the Metabolic Syndrome

The metabolic syndrome describes a clustering of risk factors—visceral obesity, dyslipidaemia, insulin resistance, and salt-sensitive hypertension—that increases mortality related to cardiovascular disease, type 2 diabetes, cancer, and non-alcoholic fatty liver disease. The prevalence of these concurrent comorbidities is ~ 25–30% worldwide, and metabolic syndrome therefore presents a significant global public health burden. Evidence from clinical and preclinical studies indicates that glucocorticoid excess is a key causal feature of metabolic syndrome. This is not increased systemic in circulating cortisol, rather increased bioavailability of active glucocorticoids within tissues. This review examines the role of covert glucocorticoid excess on the hypertension of the metabolic syndrome. Here, the role of the 11β-hydroxysteroid dehydrogenase enzymes, which exert intracrine and paracrine control over glucocorticoid signalling, is examined. 11βHSD1 amplifies glucocorticoid action in cells and contributes to hypertension through direct and indirect effects on the kidney and vasculature. The deactivation of glucocorticoid by 11βHSD2 controls ligand access to glucocorticoid and mineralocorticoid receptors: loss of function promotes salt retention and hypertension. As for hypertension in general, high blood pressure in the metabolic syndrome reflects a complex interaction between multiple systems. The clear association between high dietary salt, glucocorticoid production, and metabolic disorders has major relevance for human health and warrants systematic evaluation.

11β-HSD1 inhibition ameliorates diabetes-induced cardiomyocyte hypertrophy and cardiac fibrosis through modulation of EGFR activity

11β-HSD1 has been recognized as a potential therapeutic target for type 2 diabetes. Recent studies have shown that hyperglycemia leads to activation of 11β-HSD1, increasing the intracellular glucocorticoid levels. Excess glucocorticoids may lead to the clinical manifestations of cardiac injury. Therefore, the aim of this study is to investigate whether 11β-HSD1 activation contributes to the development of diabetic cardiomyopathy. To investigate the role of 11β-HSD1, we administered a selective 11β-HSD1 inhibitor in type 1 and type 2 murine models of diabetes and in cultured cardiomyocytes. Our results show that diabetes increases cortisone levels in heart tissues. 11β-HSD1 inhibitor decreased cortisone levels and ameliorated all structural and functional features of diabetic cardiomyopathy including fibrosis and hypertrophy. We also show that high levels of glucose caused cardiomyocyte hypertrophy and increased matrix protein deposition in culture. Importantly, inhibition of 11β-HSD1 attenuated these changes. Moreover, we show that 11β-HSD1 activation mediates these changes through modulating EGFR phosphorylation and activity. Our findings demonstrate that 11β-HSD1 contributes to the development of diabetic cardiomyopathy through activation of glucocorticoid and EGFR signaling pathway. These results suggest that inhibition of 11β-HSD1 might be a therapeutic strategy for diabetic cardiomyopathy, which is independent of its effects on glucose homeostasis.

Potential mechanisms of hypothalamic renin-angiotensin system activation by leptin and DOCA-salt for the control of resting metabolism

The renin-angiotensin system (RAS), originally described as a circulating hormone system, is an enzymatic cascade in which the final vasoactive peptide angiotensin II (ANG) regulates cardiovascular, hydromineral, and metabolic functions. The RAS is also synthesized locally in a number of tissues including the brain, where it can act in a paracrine fashion to regulate blood pressure, thirst, fluid balance, and resting energy expenditure/resting metabolic rate (RMR). Recent studies demonstrate that ANG AT_1A receptors (Agtr1a) specifically in agouti-related peptide (AgRP) neurons of the arcuate nucleus (ARC) coordinate autonomic and energy expenditure responses to various stimuli including deoxycorticosterone acetate (DOCA)-salt, high-fat feeding, and leptin. It remains unclear, however, how these disparate stimuli converge upon and activate this specific population of AT_1A receptors in AgRP neurons. We hypothesize that these stimuli may act to stimulate local expression of the angiotensinogen (AGT) precursor for ANG, or the expression of AT_1A receptors, and thereby local activity of the RAS within the (ARC). Here we review mechanisms that may control AGT and AT_1A expression within the central nervous system, with a particular focus on mechanisms activated by steroids, dietary fat, and leptin.

Impact of Adrenal Steroids on Regulation of Adipose Tissue

Corticosteroids are secreted by the adrenal glands and control the functions of adipose tissue via the activation of mineralocorticoid receptor (MR) and glucocorticoid receptor (GR). In turn, adipocytes release a large variety of adipokines into the bloodstream, regulating the function of several organs and tissues, including the adrenal glands, hereby controlling corticosteroid production. In adipose tissue, the activation of the MR by glucocorticoids (GC) and aldosterone affects important processes such as adipocyte differentiation, oxidative stress, autophagic flux, adipokine expression as well as local production of GC through upregulation of the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). Notably, the proinflammatory responses induced by the MR are counteracted by activation of the GR, whose activity inhibits the expression of inflammatory adipokines. Both GR and MR are deeply involved in adipogenesis and adipose expansion; hence pharmacological blockade of these two receptors has proven effective against adipose tissue dysfunction in experimental models of obesity and metabolic syndrome (MetS), suggesting a potential use for MR and GR antagonists in these clinical settings. Importantly, obesity and Cushing's syndrome (CS) share metabolic similarities and are characterized by high levels of circulating corticosteroids, which in turn are able to deeply affect adipose tissue. In addition, pharmacological approaches aimed at reducing aldosterone and GC levels, by means of the inhibition of CYP11B2 (aldosterone synthase) or 11β-HSD1, represent alternative strategies to counter the detrimental effects of excessive levels of corticosteroids, which are often observed in obesity and, more general, in MetS. © 2017 American Physiological Society. Compr Physiol 7:1425-1447, 2017.

Association of HSD11B1 gene polymorphisms with type 2 diabetes and metabolic syndrome in South Indian population

BACKGROUND

11beta-hydroxysteroid dehydrogenase Type 1 (11β-HSD1) is an NADP or NADPH-dependent enzyme that generates cortisol from cortisone for a local glucocorticoid action. Functional polymorphisms within 11beta-hydroxysteroid dehydrogenase Type 1 (HSD11B1) gene have shown an association with various factors, including insulin resistance (IR) and hypertension. In our study, we have assessed the association of HSD11B1 (rs12086634 and rs846910) gene polymorphisms with type 2 diabetes (T2D) and metabolic syndrome (metS).

METHODS

In the present study, 616 subjects were enrolled. DNA from T2D subjects (n=207), metS subjects (n=101), and their age and sex matched control subjects were analyzed. Genotyping of HSD11B1 rs12086634 and rs846910 single nucleotide polymorphisms was performed using tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). An odds ratio and 95% confidence interval were calculated to determine the association of HSD11B1 gene polymorphisms with T2D and metS.

RESULTS

The association analysis indicated that HSD11B1 rs12086634 TG contributed to an increased risk of both T2D (OR=1.91; 95% CI-1.33-2.76, P=0.0005) and metS (OR=2.37; 95% CI-1.39-4.05, P=0.0015), but HSD11B1 rs846910 AG contributed to an increased risk of T2D (OR=1.62; 95% CI-1.02-2.57, P=0.03) only. There was a statistically significant difference in systolic blood pressure between the control group with HSD11B1 rs12086634 TG genotype (128.96±13.19mmHg) and the control group with HSD11B1 rs12086634 TT genotype (123.27±10.84mmHg).

CONCLUSIONS

The results of our study indicated that the HSD11B1 rs12086634 is associated with both T2D and metS, but HSD11B1 rs846910 is associated with only T2D in South Indian population.

Virtual screening applications in short-chain dehydrogenase/reductase research

Several members of the short-chain dehydrogenase/reductase (SDR) enzyme family play fundamental roles in adrenal and gonadal steroidogenesis as well as in the metabolism of steroids, oxysterols, bile acids, and retinoids in peripheral tissues, thereby controlling the local activation of their cognate receptors. Some of these SDRs are considered as promising therapeutic targets, for example to treat estrogen-/androgen-dependent and corticosteroid-related diseases, whereas others are considered as anti-targets as their inhibition may lead to disturbances of endocrine functions, thereby contributing to the development and progression of diseases. Nevertheless, the physiological functions of about half of all SDR members are still unknown. In this respect, in silico tools are highly valuable in drug discovery for lead molecule identification, in toxicology screenings to facilitate the identification of hazardous chemicals, and in fundamental research for substrate identification and enzyme characterization. Regarding SDRs, computational methods have been employed for a variety of applications including drug discovery, enzyme characterization and substrate identification, as well as identification of potential endocrine disrupting chemicals (EDC). This review provides an overview of the efforts undertaken in the field of virtual screening supported identification of bioactive molecules in SDR research. In addition, it presents an outlook and addresses the opportunities and limitations of computational modeling and in vitro validation methods.

Discovery of Clinical Candidate 2-((2S,6S)-2-Phenyl-6-hydroxyadamantan-2-yl)-1-(3'-hydroxyazetidin-1-yl)ethanone [BMS-816336], an Orally Active Novel Selective 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitor

BMS-816336 (6n-2), a hydroxy-substituted adamantyl acetamide, has been identified as a novel, potent inhibitor against human 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme (IC₅₀ 3.0 nM) with >10000-fold selectivity over human 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2). 6n-2 exhibits a robust acute pharmacodynamic effect in cynomolgus monkeys (ED₅₀ 0.12 mg/kg) and in DIO mice. It is orally bioavailable (%F ranges from 20 to 72% in preclinical species) and has a predicted pharmacokinetic profile of a high peak to trough ratio and short half-life in humans. This ADME profile met our selection criteria for once daily administration, targeting robust inhibition of 11β-HSD1 enzyme for the first 12 h period after dosing followed by an "inhibition holiday" so that the potential for hypothalamic-pituitary-adrenal (HPA) axis activation might be mitigated. 6n-2 was found to be well-tolerated in phase 1 clinical studies and represents a potential new treatment for type 2 diabetes, metabolic syndrome, and other human diseases modulated by glucocorticoid control.

Discovery of Novel Insulin Sensitizers: Promising Approaches and Targets

Insulin resistance is the undisputed root cause of type 2 diabetes mellitus (T2DM). There is currently an unmet demand for safe and effective insulin sensitizers, owing to the restricted prescription or removal from market of certain approved insulin sensitizers, such as thiazolidinediones (TZDs), because of safety concerns. Effective insulin sensitizers without TZD-like side effects will therefore be invaluable to diabetic patients. The specific focus on peroxisome proliferator-activated receptor γ- (PPARγ-) based agents in the past decades may have impeded the search for novel and safer insulin sensitizers. This review discusses possible directions and promising strategies for future research and development of novel insulin sensitizers and describes the potential targets of these agents. Direct PPARγ agonists, selective PPARγ modulators (sPPARγMs), PPARγ-sparing compounds (including ligands of the mitochondrial target of TZDs), agents that target the downstream effectors of PPARγ, along with agents, such as heat shock protein (HSP) inducers, 5'-adenosine monophosphate-activated protein kinase (AMPK) activators, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) selective inhibitors, biguanides, and chloroquines, which may be safer than traditional TZDs, have been described. This minireview thus aims to provide fresh perspectives for the development of a new generation of safe insulin sensitizers.

Obesity and hypertension

Obesity and in particular the excessive visceral fat distribution is accompanied by several alterations at hormonal, inflammatory and endothelial level. These alterations induce a stimulation of several other mechanisms that contribute to the hypertensive state and on the other side to increase the cardiovascular morbidity. In these chapter we will examine the main mechanisms of obesity and obesity-related hypertension and in particular the role of sympathetic nervous system, the alterations of the renal function and at the microvascular level. We will also depict the role of insulin resistance as factor stimulating and potentiating the other mechanisms. The second part will be focalized on the major target organ damage linked with obesity and obesity-related hypertension. We will finally describe the management and treatment of obesity and the antihypertensive drug therapies more effective in hypertensive obeses.

Analysis of Purified Pancreatic Islet Beta and Alpha Cell Transcriptomes Reveals 11β-Hydroxysteroid Dehydrogenase (Hsd11b1) as a Novel Disallowed Gene

We and others have previously identified a group of genes, dubbed "disallowed," whose expression is markedly lower in pancreatic islets than in other mammalian cell types. Forced mis-expression of several members of this family leads to defective insulin secretion, demonstrating the likely importance of disallowance for normal beta cell function. Up to now, transcriptomic comparisons have been based solely on data from whole islets. This raises the possibilities that (a) there may be important differences in the degree of disallowance of family members between beta and other either neuroendocrine cells; (b) beta (or alpha) cell disallowed genes may have gone undetected. To address this issue, we survey here recent massive parallel sequencing (RNA-Seq) datasets from purified mouse and human islet cells. Our analysis reveals that the most strongly disallowed genes are similar in beta and alpha cells, with 11β-hydroxysteroid dehydrogenase (Hsd11b1) mRNA being essentially undetectable in both cell types. The analysis also reveals that several genes involved in cellular proliferation, including Yap1 and Igfbp4, and previously assumed to be disallowed in both beta and alpha cells, are selectively repressed only in the beta cell. The latter finding supports the view that beta cell growth is selectively restricted in adults, providing a mechanism to avoid excessive insulin production and the risk of hypoglycaemia. Approaches which increase the expression or activity of selected disallowed genes in the beta cell may provide the basis for novel regenerative therapies in type 2 diabetes.

Postnatal treatment with metyrapone attenuates the effects of diet-induced obesity in female rats exposed to early-life stress

Experimental studies in rodents have shown that females are more susceptible to exhibiting fat expansion and metabolic disease compared with males in several models of fetal programming. This study tested the hypothesis that female rat pups exposed to maternal separation (MatSep), a model of early-life stress, display an exacerbated response to diet-induced obesity compared with male rats. Also, we tested whether the postnatal treatment with metyrapone (MTP), a corticosterone synthase inhibitor, would attenuate this phenotype. MatSep was performed in WKY offspring by separation from the dam (3 h/day, postnatal days 2-14). Upon weaning, male and female rats were placed on a normal (ND; 18% kcal fat) or high-fat diet (HFD; 60% kcal fat). Nondisturbed littermates served as controls. In male rats, no diet-induced differences in body weight (BW), glucose tolerance, and fat tissue weight and morphology were found between MatSep and control male rats. However, female MatSep rats displayed increased BW gain, fat pad weights, and glucose intolerance compared with control rats (P < 0.05). Also, HFD increased plasma corticosterone (196 ± 51 vs. 79 ± 18 pg/ml, P < 0.05) and leptin levels (1.8 ± 0.4 vs. 1.3 ± 0.1 ng/ml, P < 0.05) in female MatSep compared with control rats, whereas insulin and adiponectin levels were similar between groups. Female control and MatSep offspring were treated with MTP (50 µg/g ip) 30 min before the daily separation. MTP treatment significantly attenuated diet-induced obesity risk factors, including elevated adiposity, hyperleptinemia, and glucose intolerance. These findings show that exposure to stress hormones during early life could be a key event to enhance diet-induced obesity and metabolic disease in female rats. Thus, pharmacological and/or behavioral inflection of the stress levels is a potential therapeutic approach for prevention of early life stress-enhanced obesity and metabolic disease.

Obesity: A Perspective from Hypertension

The prevalence of obesity-related hypertension is high worldwide and has become a major health issue. The mechanisms by which obesity relates to hypertensive disease are still under intense research scrutiny, and include altered hemodynamics, impaired sodium homeostasis, renal dysfunction, autonomic nervous system imbalance, endocrine alterations, oxidative stress and inflammation, and vascular injury. Most of these contributing factors interact with each other at multiple levels. Thus, as a multifactorial and complex disease, obesity-related hypertension should be recognized as a distinctive form of hypertension, and specific considerations should apply in planning therapeutic approaches to treat obese individuals with high blood pressure.

11β-Hydroxysteroid Dehydrogenase Type 1(11β-HSD1) mediates insulin resistance through JNK activation in adipocytes

Glucocorticoids are used to treat a number of human diseases but often lead to insulin resistance and metabolic syndrome. 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a key enzyme that catalyzes the intracellular conversion of cortisone to physiologically active cortisol. Despite the known role of 11β-HSD1 and active glucocorticoid in causing insulin resistance, the molecular mechanisms by which insulin resistance is induced remain elusive. The aim of this study is to identify these mechanisms in high fat diet (HFD) experimental models. Mice on a HFD were treated with 11β-HSD1 inhibitor as well as a JNK inhibitor. We then treated 3T3-L1-derived adipocytes with prednisone, a synthetic glucocorticoid, and cells with 11β-HSD1 overexpression to study insulin resistance. Our results show that 11β-HSD1 and JNK inhibition mitigated insulin resistance in HFD mice. Prednisone stimulation or overexpression of 11β-HSD1 also caused JNK activation in cultured adipocytes. Inhibition of 11β-HSD1 blocked the activation of JNK in adipose tissue of HFD mice as well as in cultured adipocytes. Furthermore, prednisone significantly impaired the insulin signaling pathway, and these effects were reversed by 11β-HSD1 and JNK inhibition. Our study demonstrates that glucocorticoid-induced insulin resistance was dependent on 11β-HSD1, resulting in the critical activation of JNK signaling in adipocytes.

A post-weaning fish oil dietary intervention reverses adverse metabolic outcomes and 11β-hydroxysteroid dehydrogenase type 1 expression in postnatal overfed rats

Early life is considered a critical period for determining long-term metabolic health. Postnatal over-nutrition may alter glucocorticoid (GC) metabolism and increase the risk of developing obesity and metabolic disorders in adulthood. Our aim was to assess the effects of the dose and timing of a fish oil diet on obesity and the expression of GC-activated enzyme 11β-hydroxysteroid dehydrogenase type 1 (HSD1) in postnatal overfed rats. Litter sizes were adjusted to three (small litter (SL)) or ten (normal litter) rats on postnatal day 3 to induce overfeeding or normal feeding. The SL rats were divided into three groups after weaning: high-dose fish oil (HFO), low-dose fish oil (LFO) and standard-diet groups. After 10 weeks, the HFO diet reduced body weight gain (16 %, P0·05). In conclusion, the post-weaning HFO diet could reverse adverse outcomes and decrease tissue GC activity in postnatal overfed rats.

Influence of sub-chronic selective 11β-hydroxysteroid dehydrogenase 1 inhibition on the hypothalamic-pituitary-adrenal axis in female cynomolgus monkeys

Inhibition of local cortisol regeneration from circulating cortisone by blocking 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) has been shown to ameliorate the risk factors associated with the metabolic syndrome. Chronic modulation of glucocorticoid homeostasis may result in hypothalamic-pituitary-adrenal (HPA) axis stimulation. HPA axis over-activation leading androgen excess would be undesirable in a therapeutic intervention designed to treat a chronic condition such as the metabolic syndrome. To address whether 11β-HSD1 inhibition would lead to excess androgens, we treated female cynomolgus monkeys with a selective inhibitor, BI 135558, for 4 weeks. Continual action of the compound over the dosing period was confirmed by constant plasma exposure, and a maintained change in urinary glucocorticoid metabolites consistent with 11β-HSD1 inhibition. No significant changes in adrenal function, as evidenced by an adrenocorticotropic hormone (ATCH) challenge, were observed. An examination of androgenic hormones revealed a slight increase in dehydroepiandrosterone sulfate (DHEA-S), while other hormones such as testosterone remained within reference values. Overall, treatment with BI 135558 in monkeys did not result in obvious over-activation of the HPA axis.

The expression of 11β-hydroxysteroid dehydrogenase type 1 is increased in experimental periodontitis in rats

Background

The involvement of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which converts inactive glucocorticoids into active glucocorticoids intracellularly, in metabolic diseases and chronic inflammatory diseases has been elucidated. We recently reported that an increase in 11β-HSD1 expression was associated with chronic periodontitis in humans irrespective of obesity. To further clarify the role of 11β-HSD1 in chronic periodontitis, the expression of 11β-HSD1 was investigated in experimental periodontitis model in rats.

Methods

Experimental periodontitis was induced by silk ligature of left maxillary second molars of 7-week-old male Wistar rats, and periodontal tissues were collected at day 3. The expression of 11β-HSD1, 11β-HSD2, and TNFα mRNA was examined using real time reverse transcription-polymerase chain reaction. The expression of TNFα was used as an indicator of inflammation. Thus, the rats in which the levels of TNFα mRNA were increased in the ligature-induced periodontitis compared with the control were analysed.

Results

The findings demonstrated that the expression of 11β-HSD1 mRNA was significantly increased in experimental periodontitis compared with the control. The increase in the levels of 11β-HSD1 mRNA in the ligature-induced periodontitis compared with the control was positively correlated with that of TNFα mRNA. On the other hand, the expression of 11β-HSD2 mRNA, which inactivates glucocorticoids, was slightly decreased in experimental periodontitis. Therefore, the ratio of 11β-HSD1 versus 11β-HSD2 mRNA was significantly higher in experimental periodontitis than in the control.

Conclusions

These results suggest that the increased expression of 11β-HSD1, which would result in the increased levels of intracellular glucocorticoids, may play a role in the pathophysiology of experimental periodontitis.

Polymorphisms of the GR and HSD11B1 genes influence body mass index and weight gain during hormone replacement treatment in patients with Addison's disease

OBJECTIVE

Glucocorticoid substitution is essential in patients with chronic primary adrenocortical insufficiency (Addison's disease) and both over-treatment and inadequate dosage have deleterious effects. Individual sensitivity to glucocorticoids is partly genetically determined.

CONTEXT

To test the hypothesis whether the well-characterized SNPs of the GR and HSD11B1 genes may modulate the individual sensitivity to exogenous glucocorticoids and may influence clinical and/or laboratory parameters and the glucocorticoid substitution dosage in patients with Addison's disease.

PATIENTS AND METHODS

68 patients with primary adrenocortical insufficiency were involved. Clinical and laboratory data, as well as the dosage of the hormone replacement therapy were collected. Peripheral blood DNA was isolated, and the GR and HSD11B1 SNPs were examined using allele-specific PCR or Taqman assay on Real Time PCR.

RESULTS

The allele frequency of the GR N363S polymorphism was higher in patients compared to the control group and the disease appeared significantly earlier in patients harbouring the GR A3669G compared to noncarriers. These patients had higher ACTH level measured at the time of diagnosis. Homozygous BclI carriers had higher body mass index (BMI) and lower total hydrocortisone equivalent supplementation dose needed than heterozygous or noncarriers. The BMI and weight gain during hormone replacement therapy were also higher in carriers of the HSD11B1 rs4844880 treated with glucocorticoids other than dexamethasone.

CONCLUSION

The BclI polymorphism of the GR gene and the rs4844880 of the HSD11B1 gene may contribute to weight gain and may affect the individual need of glucocorticoid substitution dose in these patients.