11 beta-hydroxysteroid dehydrogenase type 1 in obesity and the metabolic syndrome

Gestational exposure to bisphenol S induces microvesicular steatosis in male rat offspring by modulating metaflammation

Prenatal exposure to endocrine-disrupting bisphenol A (BPA) shows a long-lasting programming effect on an organ's metabolic function and predisposes it to the risk of adult metabolic diseases. Although a reduced contaminant risk due to "BPA-free" exposure is proposed, limited data on a comparative assessment of gestational exposure to BPS and BPA and their effects on metaflammation in predisposing liver metabolic disease is reported. Pregnant Wistar rats were exposed to BPS and BPA (0.0, 0.4, 4.0 μg/kg bw) via gavage from gestational day 4 to 21, and effects were assessed in the 90 d male offspring. Prenatal BPS-exposed offspring showed a more obesogenic effect than BPA, including changes in body fat distribution, feed efficiency, and leptin signalling. The BPS exposure induced the adipocyte hypertrophy of visceral adipose to a greater extent than BPA. The adipose hypertrophy was augmented by tissue inflammation, endoplasmic reticulum (ER) stress, and apoptosis due to increased expression of pro-inflammatory (IL6, IL1β, CRP, COX2) cytokines, ER stress modulator (CHOP), and apoptotic effector (Caspase 3). The enlarged, stressed, inflamed adipocytes triggered de novo lipogenesis in the bisphenol-exposed offspring liver due to increased expression of cholesterol and lipid biogenesis mediators (srebf1, fasn, acaca, PPARα) concomitant with elevated triacylglycerol (TG) and cholesterol (TC), resulted in impaired hepatic clearance of lipids. The lipogenic effects were also promoted by increased expression of HSD11β1. BPS exposure increased absolute liver weight, discoloration, altered liver lobes more than in BPA. Liver histology showed numerous lipid droplets, and hepatocyte ballooning, upregulated ADRP expression, an increased expression of pro-inflammatory mediators (IL6, CRP, IL1β, TNFα, COX2), enhanced lipid peroxidation in the BPS-exposed offspring's liver suggest altered metaflammation leads to microvesicular steatosis. Overall, gestational BPS exposure demonstrated a higher disruption in metabolic changes than BPA, involving excess adiposity, liver fat, inflammation, and predisposition to steatosis in the adult male offspring.

11β-Hydroxysteroid Dehydrogenase Type 1 as a Potential Treatment Target in Cardiovascular Diseases

Glucocorticoids (GCs) belong to the group of steroid hormones. Their representative in humans is cortisol. GCs are involved in most physiological processes of the body and play a significant role in important biological processes, including reproduction, growth, immune responses, metabolism, maintenance of water and electrolyte balance, functioning of the central nervous system and the cardiovascular system. The availability of cortisol to the glucocorticoid receptor is locally controlled by the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). Evidence of changes in intracellular GC metabolism in the pathogenesis of obesity, metabolic syndrome (MetS) and cardiovascular complications highlights the role of selective 11β-HSD1 inhibition in the pharmacotherapy of these diseases. This paper discusses the role of 11β-HSD1 in MetS and its cardiovascular complications and the importance of selective inhibition of 11β-HSD1.

Impact of downstream effects of glucocorticoid receptor dysfunction on organ function in critical illness-associated systemic inflammation

Glucocorticoids (GCs) are stress hormones that regulate developmental and physiological processes and are among the most potent anti-inflammatory drugs to suppress chronic and acute inflammation. GCs act through the glucocorticoid receptor (GR), a ubiquitously expressed ligand-activated transcription factor, which translocates into the nucleus and can act via two different modes, as a GR monomer or as a GR dimer. These two modes of action are not clearly differentiated in practice and may lead to completely different therapeutic outcomes. Detailed aspects of GR mechanisms are often not taken into account when GCs are used in different clinical scenarios. Patients, with critical illness-related corticosteroid insufficiency, treated with natural or synthetic GCs are still missing a clearly defined therapeutic strategy. This review discusses the different modes of GR function and its importance on organ function in vivo.

11β‑hydroxysteroid dehydrogenase‑1 is associated with the activation of hepatic stellate cells in the development of hepatic fibrosis

Hepatic fibrosis (HF) is a common complication of numerous chronic liver diseases, but predominantly results from persistent liver inflammation or injury. If left untreated, HF can progress and develop into liver cirrhosis and even hepatocellular carcinoma. However, the underlying molecular mechanisms of HF remain unknown. The present study aimed to investigate the role of 11β-hydroxysteroid dehydrogenase-1 (11β-HSD1) during the development of hepatic fibrosis. An experimental rat model of liver fibrosis was induced using porcine serum. 11β-HSD1 gene expression levels and enzyme activity during hepatic fibrogenesis were assessed. 11β-HSD1 gene knockdown using small interfering RNA and overexpression were performed in LX2-human hepatic stellate cells (HSCs). HSCs were stimulated with transforming growth factor-β1 (TGF-β1). Cell cycle distribution, proliferation, collagen secretion and 11β-HSD1 gene activity in HSCs were compared before and after stimulation. As hepatic fibrosis progressed, 11β-HSD1 gene expression and activity increased, indicating a positive correlation with typical markers of liver fibrosis. 11β-HSD1 inhibition markedly reduced the degree of fibrosis. The cell proliferation was increased, the number of cells in the G₀/G₁ phase decreased and the number of cells in the S and G₂/M phases increased in the pSuper transfected group compared with the N group. In addition, the overexpression of 11β-HSD1 enhanced the TGF-β1-induced activation of LX2-HSCs and enzyme activity of connective tissue growth factor. 11β-HSD1 knockdown suppressed cell proliferation by blocking the G₀/G₁ phase of the cell cycle, which was associated with HSC stimulation and inhibition of 11β-HSD1 enzyme activity. In conclusion, increased 11β-HSD1 expression in the liver may be partially responsible for hepatic fibrogenesis, which is potentially associated with HSC activation and proliferation.

Imbalanced cortisol concentrations in glycogen storage disease type I: evidence for a possible link between endocrine regulation and metabolic derangement

Background

Glycogen storage disease type I (GSDI) is an inborn error of carbohydrate metabolism caused by mutations of either the G6PC gene (GSDIa) or the SLC37A4 gene (GSDIb). Glucose 6-phosphate (G6P) availability has been shown to modulate 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1), an ER-bound enzyme catalyzing the local conversion of inactive cortisone into active cortisol. Adrenal cortex assessment has never been performed in GSDI. The aim of the current study was to evaluate the adrenal cortex hormones levels in GSDI patients.

Methods

Seventeen GSDI (10 GSDIa and 7 GSDIb) patients and thirty-four age and sex-matched controls were enrolled. Baseline adrenal cortex hormones and biochemical markers of metabolic control serum levels were analyzed. Low dose ACTH stimulation test was also performed.

Results

Baseline cortisol serum levels were higher in GSDIa patients (p = 0.042) and lower in GSDIb patients (p = 0.041) than controls. GSDIa patients also showed higher peak cortisol response (p = 0.000) and Cortisol AUC (p = 0.029). In GSDIa patients, serum cholesterol (p = 0.000), triglycerides (p = 0.000), lactate (p = 0.000) and uric acid (p = 0.008) levels were higher and bicarbonate (p = 0.000) levels were lower than controls. In GSDIb patients, serum cholesterol levels (p = 0.016) were lower and lactate (p = 0.000) and uric acid (p = 0.000) levels were higher than controls. Baseline cortisol serum levels directly correlated with cholesterol (ρ = 0.65, p = 0.005) and triglycerides (ρ = 0.60, p = 0.012) serum levels in GSDI patients.

Conclusions

The present study showed impaired cortisol levels in GSDI patients, with opposite trend between GSDIa and GSDIb. The otherwise preserved adrenal cortex function suggests that this finding might be secondary to local deregulation rather than hypothalamo-pituitary-adrenal axis dysfunction in GSDI patients. We hypothesize that 11βHSD1 might represent the link between endocrine regulation and metabolic derangement in GSDI, constituting new potential therapeutic target in GSDI patients.

11β-Hydroxysteroid dehydrogenase type 1 inhibition in idiopathic intracranial hypertension: a double-blind randomized controlled trial

Treatment options for idiopathic intracranial hypertension are limited. The enzyme 11β-hydroxysteroid dehydrogenase type 1 has been implicated in regulating cerebrospinal fluid secretion, and its activity is associated with alterations in intracranial pressure in idiopathic intracranial hypertension. We assessed therapeutic efficacy, safety and tolerability and investigated indicators of in vivo efficacy of the 11β-hydroxysteroid dehydrogenase type 1 inhibitor AZD4017 compared with placebo in idiopathic intracranial hypertension. A multicenter, UK, 16-week phase II randomized, double-blind, placebo-controlled trial of 12-week treatment with AZD4017 or placebo was conducted. Women aged 18–55 years with active idiopathic intracranial hypertension (>25 cmH₂O lumbar puncture opening pressure and active papilledema) were included. Participants received 400 mg of oral AZD4017 twice daily compared with matching placebo over 12 weeks. The outcome measures were initial efficacy, safety and tolerability. The primary clinical outcome was lumbar puncture opening pressure at 12 weeks analysed by intention-to-treat. Secondary clinical outcomes were symptoms, visual function, papilledema, headache and anthropometric measures. In vivo efficacy was evaluated in the central nervous system and systemically. A total of 31 subjects [mean age 31.2 (SD = 6.9) years and body mass index 39.2 (SD = 12.6) kg/m²] were randomized to AZD4017 (n = 17) or placebo (n = 14). At 12 weeks, lumbar puncture pressure was lower in the AZD4017 group (29.7 cmH₂O) compared with placebo (31.3 cmH₂O), but the difference between groups was not statistically significant (mean difference: −2.8, 95% confidence interval: −7.1 to 1.5; P = 0.2). An exploratory analysis assessing mean change in lumbar puncture pressure within each group found a significant decrease in the AZD4017 group [mean change: −4.3 cmH₂O (SD = 5.7); P = 0.009] but not in the placebo group [mean change: −0.3 cmH₂O (SD = 5.9); P = 0.8]. AZD4017 was safe, with no withdrawals related to adverse effects. Nine transient drug-related adverse events were reported. One serious adverse event occurred in the placebo group (deterioration requiring shunt surgery). In vivo biomarkers of 11β-hydroxysteroid dehydrogenase type 1 activity (urinary glucocorticoid metabolites, hepatic prednisolone generation, serum and cerebrospinal fluid cortisol:cortisone ratios) demonstrated significant enzyme inhibition with the reduction in serum cortisol:cortisone ratio correlating significantly with reduction in lumbar puncture pressure (P = 0.005, R = 0.70). This is the first phase II randomized controlled trial in idiopathic intracranial hypertension evaluating a novel therapeutic target. AZD4017 was safe and well tolerated and inhibited 11β-hydroxysteroid dehydrogenase type 1 activity in vivo. Reduction in serum cortisol:cortisone correlated with decreased intracranial pressure. Possible clinical benefits were noted in this small cohort. A longer, larger study would now be of interest.

Xenobiotic Metabolising Enzymes: Impact on Pathologic Conditions, Drug Interactions and Drug Design

Background:

The biotransformation of xenobiotics is a homeostatic defensive response of the body against bioactive invaders. Xenobiotic metabolizing enzymes, important for the metabolism, elimination and detoxification of exogenous agents, are found in most tissues and organs and are distinguished into phase I and phase II enzymes, as well as phase III transporters. The cytochrome P450 superfamily of enzymes plays a major role in the biotransformation of most xenobiotics as well as in the metabolism of important endogenous substrates such as steroids and fatty acids. The activity and the potential toxicity of numerous drugs are strongly influenced by their biotransformation, mainly accomplished by the cytochrome P450 enzymes, one of the most versatile enzyme systems.

Objective:

In this review, considering the importance of drug metabolising enzymes in health and disease, some of our previous research results are presented, which, combined with newer findings, may assist in the elucidation of xenobiotic metabolism and in the development of more efficient drugs.

Conclusion:

Study of drug metabolism is of major importance for the development of drugs and provides insight into the control of human health. This review is an effort towards this direction and may find useful applications in related medical interventions or help in the development of more efficient drugs.

Evaluation of the hypothalamic-pituitary-adrenal axis in a case series of familial partial lipodystrophy

BACKGROUND

Familial partial lipodystrophy (FPL) is a rare genetic disease characterized by body fat abnormalities that lead to insulin resistance (IR). Clinical conditions linked to milder IR, such as type 2 diabetes (T2D) and metabolic syndrome, are associated with abnormalities of the hypothalamic-pituitary-adrenal (HPA) axis, but little is known about its activity in FPL.

METHODS

Patients meeting the clinical criteria for FPL were subjected to anthropometric, biochemical and hormone analyses. A genetic study to identify mutations in the genes encoding peroxisome proliferator-activated receptor gamma (PPARγ) was performed. Polycystic ovary syndrome and hepatic steatosis were investigated, and the patient body compositions were analyzed via dual X-ray energy absorptiometry (DXA). The HPA axis was assessed via basal [cortisol, adrenocorticotrophic hormone (ACTH), cortisol binding globulin, nocturnal salivary cortisol and urinary free cortisol (UFC)] as well as dynamic suppression tests (cortisol post 0.5 mg and post 1 mg dexamethasone).

RESULTS

Six patients (five female and one male) aged 17 to 42 years were included. In DXA analyses, the fat mass ratio between the trunk and lower limbs (FMR) was > 1.2 in all phenotypes. One patient had a confirmed mutation in the PPARγ gene: a novel heterozygous substitution of p. Arg 212 Trp (c.634C>T) at exon 5. HPA sensitivity to glucocorticoid feedback was preserved in all six patients, and a trend towards lower basal serum cortisol, serum ACTH and UFC values was observed.

CONCLUSIONS

Our findings suggest that FPL is not associated with overt abnormalities in the HPA axis, despite a trend towards low-normal basal cortisol and ACTH values and lower UFC levels. These findings suggest that the extreme insulin resistance occurring in FPL may lead to a decrease in HPA axis activity without changing its sensitivity to glucocorticoid feedback, in contrast to the abnormalities in HPA axis function in T2D and common metabolic syndrome.

Comparison of flavonoids and isoflavonoids to inhibit rat and human 11β-hydroxysteroid dehydrogenase 1 and 2

Many flavonoids and isoflavonoids have anti-diabetic effects in animal models. However, the mechanisms that are involved are generally unclear. Since 11β-hydroxysteroid dehydrogenases (HSD11Bs) play important roles in diabetes, we hypothesize that flavonoids and isoflavonoids may affect diabetes by targeting two isoforms of HSD11B differently. The inhibitory effects of flavonoids (apigenin and quercetin) and isoflavonoids [genistein and (±) equol] on rat and human HSD11B1 and HSD11B2 were analyzed. The potencies of inhibition on human HSD11B1 reductase was in the order of apigenin > quercetin > genistein > (±) equol, with IC₅₀ values of 2.19, 5.36, 11.00, and over 100 μM, respectively. Genistein also inhibited rat HSD11B1 reductase with IC₅₀ value of 24.58 μM, while other three chemicals showed no effects on the enzyme activity with IC₅₀ values over 100 μM. However, apigenin and (±) equol did not inhibit human HSD11B2 at concentrations as high as 100 μM, while genistein and quercetin inhibited human HSD11B2 by 60% and 50% at 100 μM, respectively. The effective flavonoids and isoflavonoids are noncompetitive inhibitors of HSD11B1 when steroid substrates were used. Docking analysis showed that they bound to the steroid-binding site of the human HSD11B1. These data indicate that apigenin is a selective inhibitor of human HSD11B1 of two HSD11B isoforms, which may be useful in managing symptoms of the metabolic syndrome.

The cortisol-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 in skeletal muscle in the pathogenesis of the metabolic syndrome

The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) contributes to intracellular glucocorticoid action by converting inactive cortisone to its receptor-active form cortisol (11-dehydrocorticosterone and corticosterone in mice and rats). The potential role of 11β-HSD1 in the pathogenesis of the metabolic syndrome has emerged over the past three decades. However, the precise impact of 11β-HSD1 in obesity-related diseases remains uncertain. Many studies from animal experiments to clinical studies have investigated liver and adipose tissue 11β-HSD1 in relation to obesity and its metabolic disorders including insulin resistance. But the relevance of 11β-HSD1 in skeletal muscle has been less extensively studied. On the other hand, skeletal muscle is assumed to be the main site of peripheral insulin resistance, but the biological relevance of 11β-HSD1 in skeletal muscle is unclear. This mini-review will focus on 11β-HSD1 in skeletal muscle and its postulated link to obesity and insulin-resistance.

Carbonyl reductase 1 catalyzes 20β-reduction of glucocorticoids, modulating receptor activation and metabolic complications of obesity

Carbonyl Reductase 1 (CBR1) is a ubiquitously expressed cytosolic enzyme important in exogenous drug metabolism but the physiological function of which is unknown. Here, we describe a role for CBR1 in metabolism of glucocorticoids. CBR1 catalyzes the NADPH- dependent production of 20β-dihydrocortisol (20β-DHF) from cortisol. CBR1 provides the major route of cortisol metabolism in horses and is up-regulated in adipose tissue in obesity in horses, humans and mice. We demonstrate that 20β-DHF is a weak endogenous agonist of the human glucocorticoid receptor (GR). Pharmacological inhibition of CBR1 in diet-induced obesity in mice results in more marked glucose intolerance with evidence for enhanced hepatic GR signaling. These findings suggest that CBR1 generating 20β-dihydrocortisol is a novel pathway modulating GR activation and providing enzymatic protection against excessive GR activation in obesity.

Effects of Cellular 11β-hydroxysteroid Dehydrogenase 1 on LPS-induced Inflammatory Responses in Synovial Cell Line, SW982

11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) catalyzes the conversion of inactive cortisone into active cortisol, which has pleiotropic roles in various biological conditions, such as immunological and metabolic homeostasis. Cortisol is mainly produced in the adrenal gland, but can be locally regenerated in the liver, fat, and muscle. Its diverse actions are primarily mediated by binding to the glucocorticoid receptor. SW982, a human synovial cell line, expresses 11β-HSD type 1, but not type 2, that catalyzes the conversion of cortisone to cortisol. In this study, therefore, we investigated the control of lipopolysaccharide (LPS)-induced inflammatory responses by prereceptor regulation-mediated maintenance of cortisol levels. Preliminarily, cell seeding density and incubation period were optimized for analyzing the catalytic activity of SW982. Additionally, cellular 11β-HSD1 still remained active irrespective of monolayer or spheroid culture conditions. Inflammatory stimulants, such as interleukin (IL)-1β, tumor necrosis factor (TNF)α, and LPS, did not affect the catalytic activity of 11β-HSD1, although a high dose of LPS significantly decreased its activity. Additionally, autocrine effects of cortisol on inflammatory responses were investigated in LPS-stimulated SW982 cells. LPS upregulated pro-inflammatory cytokines, including IL-6 and IL-1β, in SW982 cells, while cortisol production, catalyzed by cellular 11β-HSD1, downregulated LPS-stimulated cytokines. Furthermore, suppression of NFκB activation-mediated pro-inflammatory responses by cortisol was revealed. In conclusion, the activity of cellular 11β-HSD1 was closely correlated with suppression of LPS-induced inflammation. Therefore, these results partly support the notion that prereceptor regulation of locally regenerated cortisol could be taken into consideration for treatment of inflammation-associated diseases, including arthritis.

The degree of urinary hypercortisolism is not correlated with the severity of cushing's syndrome

Cushing syndrome (CS) is characterized by increased morbidity and mortality compared to the general population. However, there are patients who have more clinical aggressive forms than others. Aim of the study is to evaluate whether the degree of hypercortisolism, defined by the number of times urinary free cortisol (UFC) levels exceed the upper limit of the normal range (ULN), is related to the worsening of phenotypic features, as well as metabolic and cardiovascular parameters, in a cohort of CS patients. A cross-sectional study was conducted on 192 patients with active CS, consecutively presenting at the outpatients' clinic of the University Hospitals of Ancona, Naples, and Palermo. Patients were grouped into mild (UFC not exceeding twice the ULN), moderate (2-5 times the ULN), and severe (more than 5 times the ULN) hypercortisolism. Thirty-seven patients (19.3 %) had mild, 115 (59.8 %) moderate, and 40 (20.9 %) severe hypercortisolism. A significant trend of increase among the three groups was demonstrated for 8-, 16-, and 24-h serum cortisol levels (p < 0.001) and serum cortisol after low dose of dexamethasone suppression test (p = 0.001). No significant trend of increase was found regarding phenotype and comorbidities. The degree of hypercortisolism by itself does not appear to be a sufficient parameter to express the severity of CS. Therefore, estimating the severity of CS according to biochemical parameters remains a challenge, while the clinical phenotype and the associated comorbidities might be more useful to assessing the severity of the CS.

Privileged heterocycles: bioactivity and synthesis of 1,9-diazaspiro[5.5]undecane-containing compounds

This review discusses the biological activity and synthesis of 1,9-diazaspiro[5.5]undecanes, including those ring-fused with arenes and heteroarenes and/or containing a carbonyl group at position 2. These compounds could be used for the treatment of obesity, pain, as well as various immune system, cell signaling, cardiovascular, and psychotic disorders.

Loss of 11βHSD1 enhances glycolysis, facilitates intrahepatic metastasis, and indicates poor prognosis in hepatocellular carcinoma

11Beta-hydroxysteroid dehydrogenase type 1 (11βHSD1), converting glucocorticoids from hormonally inactive cortisone to active cortisol, plays an essential role in glucose homeostasis. Accumulating evidence suggests that enhanced glycolytic activity is closely associated with postoperative recurrence and prognosis of hepatocellular carcinoma (HCC). Whether 11βHSD1 contributes to HCC metastasis and recurrence remains unclear. Here we found that expression of 11βHSD1 in human HCC (310 pairs) was frequently decreased compared to the adjacent non-neoplastic liver tissues (ANT), which correlated well with the intrahepatic-metastatic index, serum glycemia, and other malignant clinicopathological characteristics of HCC and predicted poor prognosis. Knockdown of 11βHSD1 in BEL-7402 cells drastically reduced the pH of culture medium and induced cell death. Meanwhile, overexpression of 11βHSD1 in SMMC-7721 HCC cells resulted in repression of cell migration, invasion, angiogenesis, and proliferation in vitro. When transferred into BALB/c nude mice, 11βHSD1 overexpression resulted in decreased intrahepatic metastasis, angiogenesis, and tumor size. F-18-2-fluoro-2-deoxyglucose accumulation assay measured by positron emission tomography elucidated that 11βHSD1 reduced glucose uptake and glycolysis in SMMC-7721 cells in vitro, and intrahepatic metastasis foci and subcutaneous tumor growth in vivo. We showed that 11βHSD1 repressed cell metastasis, angiogenesis and proliferation of HCC by causing disruption of glycolysis via the HIF-1α and c-MYC pathways. In conclusion, 11βHSD1 inhibits the intrahepatic metastasis of HCC via restriction of tumor glycolysis activity and may serve as a prognostic biomarker for patients.

Molecular Actions of Glucocorticoids in Cartilage and Bone During Health, Disease, and Steroid Therapy

Cartilage and bone are severely affected by glucocorticoids (GCs), steroid hormones that are frequently used to treat inflammatory diseases. Major complications associated with long-term steroid therapy include impairment of cartilaginous bone growth and GC-induced osteoporosis. Particularly in arthritis, GC application can increase joint and bone damage. Contrarily, endogenous GC release supports cartilage and bone integrity. In the last decade, substantial progress in the understanding of the molecular mechanisms of GC action has been gained through genome-wide binding studies of the GC receptor. These genomic approaches have revolutionized our understanding of gene regulation by ligand-induced transcription factors in general. Furthermore, specific inactivation of GC signaling and the GC receptor in bone and cartilage cells of rodent models has enabled the cell-specific effects of GCs in normal tissue homeostasis, inflammatory bone diseases, and GC-induced osteoporosis to be dissected. In this review, we summarize the current view of GC action in cartilage and bone. We further discuss future research directions in the context of new concepts for optimized steroid therapies with less detrimental effects on bone.

Idiopathic intracranial hypertension, hormones, and 11β-hydroxysteroid dehydrogenases

Idiopathic intracranial hypertension (IIH) results in raised intracranial pressure (ICP) leading to papilledema, visual dysfunction, and headaches. Obese females of reproductive age are predominantly affected, but the underlying pathological mechanisms behind IIH remain unknown. This review provides an overview of pathogenic factors that could result in IIH with particular focus on hormones and the impact of obesity, including its role in neuroendocrine signaling and driving inflammation. Despite occurring almost exclusively in obese women, there have been a few studies evaluating the mechanisms by which hormones and adipokines exert their effects on ICP regulation in IIH. Research involving 11β-hydroxysteroid dehydrogenase type 1, a modulator of glucocorticoids, suggests a potential role in IIH. Improved understanding of the complex interplay between adipose signaling factors such as adipokines, steroid hormones, and ICP regulation may be key to the understanding and future management of IIH.

Splitting hair for cortisol? Associations of socio-economic status, ethnicity, hair color, gender and other child characteristics with hair cortisol and cortisone

The aim of this study was to examine associations of SES and ethnicity with hair cortisol and cortisone and to identify potential child and family characteristics that can assist in choosing covariates and potential confounders for analyses involving hair cortisol and cortisone concentrations. Hair samples were collected in 2484 6-year-old children from the Generation R Study, a prospective cohort in Rotterdam, the Netherlands. Measurements for cortisol and cortisone were used as the outcome in regression analyses. Predictors were SES, ethnicity, hair color and child characteristics such as birthweight, gestational age at birth, BMI, disease, allergy, and medication use. Lower family income, more children to be supported by this income, higher BMI and darker hair color were associated with higher hair cortisol and cortisone levels. Boys also showed higher levels. Ethnicity (Dutch and North European descent) was related to lower levels. High amounts of sun in the month of hair collection was related to higher levels of cortisone only. More recent hair washing was related to lower levels of cortisol and cortisone. Gestational age at birth, birth weight, age, medication use, hair washing frequency, educational level of the mother, marital status of the mother, disease and allergy were not associated with cortisol or cortisone levels. Our results serve as a starting point for choosing covariates and confounders in studies of substantive predictors or outcomes. Gender, BMI, income, the number of persons in a household, ethnicity, hair color and recency of hair washing are strongly suggested to take into account.

Gossypol ameliorates liver fibrosis in diabetic rats induced by high-fat diet and streptozocin

11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) inhibitors have been shown to treat type 2 diabetes (T2D). Since gossypol is an 11β-HSD1 inhibitor, the objective of the present study was to treat T2D and T2D-related liver fibrosis in rat model using low-dose gossypol. T2D was induced by feeding with high fat diet plus injection of streptozocin (30mg/kg). Diabetic rats were treated with either vehicle control or racemic gossypol with a dose of 15mg/kg/day for 4weeks followed by 15mg/kg/week for additional 8weeks. Blood glucose, cholesterol, LDL, and triglycerides were measured. Messenger mRNA levels of glucocorticoid receptor (Nr3c1), phosphoenolpyruvate carboxykinase (Pck1), glucose-6-phosphatase (G6pc), collagen I (Col1a1), collagen III (Col3a1), fibronectin (Fn1), tissue inhibitor of metalloproteinase 1 (Timp1), and 2 (Timp2) were measured. T2D rats had higher serum glucose, cholesterol, LDL, and triglyceride levels compared to control. Liver Nr3c1, Col1a1, Col3a1, Fn1, Timp1, and Timp2 were increased in T2D rats. T2D liver showed significant fibrosis with the increases of α-smooth muscle actin and fibronectin. After gossypol treatment, serum glucose level was lowered by 64%. Liver fibrosis was significantly ameliorated. Nr3c1, Col1a1, Col3a1, Fn1, Timp1, Timp2, Pck1 as well as G6pc levels were significantly reduced. In conclusion, low dose gossypol is effective for the treatment of T2D and T2D-related fibrosis.

Glycogen storage disease type Ia (GSDIa) but not Glycogen storage disease type Ib (GSDIb) is associated to an increased risk of metabolic syndrome: possible role of microsomal glucose 6-phosphate accumulation

BACKGROUND

In GSDIa, glucose 6-phosphate (G6P) accumulates in the endoplasmic reticulum (ER); in GSDIb, G6P levels are reduced in ER. G6P availability directly modulates the activity of 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1), an ER-bound enzyme playing a key role in the development of the metabolic syndrome (MS).

OBJECTIVE

To evaluate the prevalence of MS and Insulin Resistance (IR) in GSDIa and GSDIb patients.

PATIENTS AND METHODS

This was a prospective study. All the enrolled patients were followed at the Department of Pediatrics "Federico II" University of Naples for 10 years. Clinical and biochemical parameters of MS and the presence of IR were recorded. The results were correlated with the biochemical parameters of GSDI-related metabolic control. 10 GSDIa patient (median age 12.10 ± 1.50), 7 GSDIb patients (median age 14.90 ± 2.20 were enrolled in the study. They were compared to 20 and 14 age and sex matched controls, respectively. 10 GSDIa patients (median age 24.60 ± 1.50) and 6 GSDIb patients (median age 25.10 ± 2.00) completed the 10-year-follow-up. At the end of the study the patients' data were compared to 10 and 6 age and sex matched controls, respectively.

RESULTS

At study entry, 20 % GSDIa patients had MS and 80 % showed 2 criteria for MS. GSDIa patients showed higher HOMA-IR than controls and GSDIb patients (p < 0.001, p < 0.05), respectively. Baseline ISI was lower in GSDIa than controls (p < 0.001). QUICKI was significantly lower in GSDIa than in controls (p < 0.001). At the end of the study 70 % of GSDIa patients had MS and 30 % showed 2 criteria for MS. HOMA-IR was higher in GSDIa than controls (p < 0.01). Baseline ISI was higher in GSDIb than controls (p < 0.005) and GSD1a (p < 0.05). QUICKI was lower in GSD1a patients than in controls (p < 0.03). VAI was higher in GSDIa patients than controls (p < 0.001) and GSDIb patients (p = 0.002).

CONCLUSIONS

Our data showed high prevalence of IR and MS in GSDIa patients. We speculate a possible role of 11βHSD1 modulation by G6P availability. We suggest a routine metabolic assessment in GSDIa patients.

Hupehenols A-E, selective 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors from Viburnum hupehense

Five selective 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) competitive inhibitors, hupehenols A-E (1-5), were isolated from Viburnum hupehense. The structure elucidation indicated that compounds 1-5 are new 20,21,22,23,24,25,26,27-octanordammarane triterpenoids. Their structures were established on the basis of NMR spectroscopic and mass spectrometric analysis. Hupehenols A-E (1-5) showed inhibition against human 11β-HSD1, with hupehenols B (2) and E (5) having IC50 values of 15.3 and 34.0 nM, respectively. Moreover, hupehenols C (3) and D (4) are highly selective inhibitors of human 11β-HSD1 when compared to murine 11β-HSD1.

Glucocorticoid receptor gene expression in adipose tissue and associated metabolic risk in black and white South African women

BACKGROUND

Black women have lower visceral adipose tissue (VAT) but are less insulin sensitive than white women; the mechanisms responsible are unknown.

OBJECTIVE

The study aimed to test the hypothesis that variation in subcutaneous adipose tissue (SAT) sensitivity to glucocorticoids might underlie these differences.

METHODS

Body fatness (dual energy X-ray absorptiometry) and distribution (computerized tomography), insulin sensitivity (SI, intravenous and oral glucose tolerance tests), and expression of 11β-hydroxysteroid dehydrogenase-1 (11HSD1), hexose-6-phosphate dehydrogenase and glucocorticoid receptor-α (GRα), as well as genes involved in adipogenesis and inflammation were measured in abdominal deep SAT, superficial SAT and gluteal SAT (GLUT) depots of 56 normal-weight or obese black and white premenopausal South African (SA) women. We used a combination of univariate and multivariate statistics to evaluate ethnic-specific patterns in adipose gene expression and related body composition and insulin sensitivity measures.

RESULTS

Although 11HSD1 activity and mRNA did not differ by ethnicity, GRα mRNA levels were significantly lower in SAT of black compared with white women, particularly in the GLUT depot (0.52±0.21 vs 0.91±0.26 AU, respectively, P<0.01). In black women, lower SAT GRα mRNA levels were associated with increased inflammatory gene transcript levels and abdominal SAT area, and reduced adipogenic gene transcript levels, VAT/SAT ratio and SI. Abdominal SAT 11HSD1 activity associated with increased VAT area and decreased SI in white, but not in black women.

CONCLUSIONS

In black SA women, downregulation of GRα mRNA levels with obesity and reduced insulin sensitivity, possibly via increased SAT inflammation, is associated with reduced VAT accumulation.

Identification of novel 11β-HSD1 inhibitors by combined ligand- and structure-based virtual screening

11 beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts cortisone to cortisol in a NADPH dependent manner. Overexpression of 11β-HSD1 in key metabolic tissues is related to the development of type 2 diabetes, obesity, hypertension and metabolic syndrome. Using crystal structures of human 11β-HSD1 in complex with inhibitors as source of structural information, a combined ligand and structure-based virtual screening approach was implemented to identify novel 11β-HSD1 inhibitors. A selected group of compounds was identified in silico and further evaluated in cell-based assays for cytotoxicity and 11β-HSD1 mediated cortisol production inhibitory capacity. The expression of 11β-HSD1 and 11β-HSD2 in human LS14 adipocytes was assessed during differentiation. Biological evaluation of 39 compounds in adipocytes and steroids quantification by HPLC-MS/MS identify 4 compounds that exhibit 11β-HSD1 mediated cortisol production inhibitory activity with potencies in the micromolar range. Two compounds showed to be selective for the 11β-HSD1 reductase activity and over 11β-HSD2 isoform, and thus represent novel leads for the development of more active derivatives with higher efficacies targeting intracellular cortisol levels in type 2 diabetes and metabolic syndrome.

Diurnal cortisol pattern, eating behaviors and overweight in low-income preschool-aged children

This study examined, among children, the associations among chaos in the home, diurnal cortisol patterns, eating behaviors and being overweight. Participants included 331 low-income children aged 3-4years. Mean salivary cortisol-intercept (representing morning peak, 60min since waking) and cortisol-slope (representing diurnal decline after peak) were calculated using mixed models from samples obtained across 3days. Parents reported chaos in the home by questionnaire and responded to the Children's Eating Behavior Questionnaire, generating subscales Food Responsiveness (FR), Emotional Overeating (EO), Enjoyment of Food (EF), and Satiety Responsiveness (SR). Body mass index was categorized as overweight vs. not. Path analysis evaluated associations among chaos, cortisol patterns, eating behaviors, and weight status. Children living in more chaotic homes had lower morning cortisol levels, consistent with "hypocortisolism" reported among individuals who have experienced significant allostatic load as a result of substantial early life chronic stress. Among girls, the hypocortisolism pattern predicted a higher likelihood of being overweight both directly and mediated through reduced Satiety Responsiveness; in boys, the association of the hypocortisolism pattern with being overweight was mediated entirely through Emotional Overeating. In summary, our results provide support for the conceptual model that psychosocial stress contributes to hypocortisolism, which contributes directly to a higher likelihood of being overweight in girls, and indirectly through reduced Satiety Responsiveness in girls and through increased Emotional Overeating in boys.

Adiposopathy: how do diet, exercise and weight loss drug therapies improve metabolic disease in overweight patients?

An increase in bodyweight is generally associated with an increased risk of excessive fat-related metabolic diseases (EFRMD), including Type 2 diabetes mellitus, hypertension and dyslipidemia. However, not all patients who are overweight have EFRMD, and not all patients with EFRMD are significantly overweight. The adipocentric paradigm provides the basis for a unifying, pathophysiological process whereby fat gain in susceptible patients leads to fat dysfunction ('sick fat'), and wherein pathological abnormalities in fat function (adiposopathy) are more directly related to the onset of EFRMD than increases in fat mass (adiposity) alone. But just as worsening fat function worsens EFRMD, improved fat function improves EFRMD. Peroxisome proliferator-activated receptor-gamma agonists increase the recruitment, proliferation and differentiation of preadipocytes ('healthy fat') and cause apoptosis of hypertrophic and dysfunctional (including visceral) adipocytes resulting in improved fat function and improved metabolic parameters associated with EFRMD. Weight loss interventions, such as a hypocaloric diet and physical exercise, in addition to agents such as orlistat, sibutramine and cannabinoid receptor antagonists, may have favorable effects upon fat storage (lipogenesis and fat distribution), nutrient metabolism (such as free fatty acids), favorable effects upon adipose tissue factors involved in metabolic processes and inflammation, and enhanced 'cross-talk' with other major organ systems. In some cases, weight loss therapeutic agents may even affect metabolic parameters and adipocyte function independently of weight loss alone, suggesting that the benefit of these agents in improving EFRMD may go beyond their efficacy in weight reduction. This review describes how adiposopathy interventions may affect fat function, and thus improve EFRMD.

Curcumin as a potent and selective inhibitor of 11β-hydroxysteroid dehydrogenase 1: improving lipid profiles in high-fat-diet-treated rats

Background

11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) activates glucocorticoid locally in liver and fat tissues to aggravate metabolic syndrome. 11β-HSD1 selective inhibitor can be used to treat metabolic syndrome. Curcumin and its derivatives as selective inhibitors of 11β-HSD1 have not been reported.

Methodology

Curcumin and its 12 derivatives were tested for their potencies of inhibitory effects on human and rat 11β-HSD1 with selectivity against 11β-HSD2. 200 mg/kg curcumin was gavaged to adult male Sprague-Dawley rats with high-fat-diet-induced metabolic syndrome for 2 months.

Results and Conclusions

Curcumin exhibited inhibitory potency against human and rat 11β-HSD1 in intact cells with IC₅₀ values of 2.29 and 5.79 µM, respectively, with selectivity against 11β-HSD2 (IC₅₀, 14.56 and 11.92 µM). Curcumin was a competitive inhibitor of human and rat 11β-HSD1. Curcumin reduced serum glucose, cholesterol, triglyceride, low density lipoprotein levels in high-fat-diet-induced obese rats. Four curcumin derivatives had much higher potencies for Inhibition of 11β-HSD1. One of them is (1E,4E)-1,5-bis(thiophen-2-yl) penta-1,4-dien-3-one (compound 6), which had IC₅₀ values of 93 and 184 nM for human and rat 11β-HSD1, respectively. Compound 6 did not inhibit human and rat kidney 11β-HSD2 at 100 µM. In conclusion, curcumin is effective for the treatment of metabolic syndrome and four novel curcumin derivatives had high potencies for inhibition of human 11β-HSD1 with selectivity against 11β-HSD2.

The expression of omental 11β-HSD1 is not increased in severely obese women with metabolic syndrome

OBJECTIVE

Plasma cortisol in obese subjects does not differ from that in normoweight subjects. Extra-adrenal cortisol production by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) can result in local hypercortisolemia. The aim of the present study was to examine the role of visceral hypercortisolemia in the development of metabolic syndrome in severe obesity.

METHODS

Eight lean women during hysterectomy (controls) and 19 severely obese women during bariatric surgery were studied, 8 without metabolic syndrome (OM- group) and 11 with it (OM+ group). Biopsies of omental and subcutaneous fat were performed in the severely obese women during surgery, but only omental biopsies in the controls. Expression of 11β-HSD1, glucocorticoid receptor α (GRα) and glucocorticoid receptor β (GRβ) was evaluated using real-time PCR.

RESULTS

Omental 11β-HSD1 expression was different between groups (one-way ANOVA, p < 0.01). Post-hoc analysis revealed that mean omental 11β-HSD1 mRNA levels were higher in the OM- group compared to controls, whereas they were similar when comparing the OM+ group with lean controls. Expression of 11β-HSD1 in subcutaneous fat was not different between OM+ and OM- groups. GRα expression in omental fat did not differ among groups or between omental and subcutaneous fat in severely obese patients. An expression of GRβ was not detected.

CONCLUSION

Contrary to our original hypothesis, omental 11β-HSD1 expression is not increased in the OM+ group.

Amelioration of glucose homeostasis by glycyrrhizic acid through gluconeogenesis rate-limiting enzymes

The activities of phosphoenolpyruvate carboxykinase (PEPCK) are influenced by active glucocorticoids which are activated by 11-β-hydroxysteroid dehydrogenase 1 (11β-HSD1) while hexose-6-phosphate dehydrogenase (H6PDH) influences the activities of 11-βHSD1 in a cofactor manner. Dysregulation of PEPCK and H6PDH has been associated with the pathogenesis of metabolic syndrome. Sixteen male Sprague Dawley rats, fed ad libitum, were assigned to two groups, control and treated, with the treated group being given GA at 100mg/kg for one week. Blood and subcutaneous and visceral adipose tissue, abdominal and quadriceps femoris muscle, liver and kidney were examined. GA treatment led to an overall significant decrease in blood glucose while HOMA-IR. PEPCK activities decreased in the liver but increased in the visceral adipose tissue. H6PDH activities also decreased significantly in the liver while 11β-HSD1 activities decreased significantly in all studied tissues except for subcutaneous adipose tissue. Adipocytes in the subcutaneous and visceral depots showed a reduction in size. Though increased glycogen storage was seen in the liver, no changes were observed in the kidneys and muscles. Results from this study may imply that GA could counteract the development of type 2 diabetes mellitus by improving insulin sensitivity and probably by reduction of H6PDH, 11β-HSD1 and a selective decrease in PEPCK activities.

11-Hydroxy-β-steroid dehydrogenase gene expression in canine adipose tissue and adipocytes: stimulation by lipopolysaccharide and tumor necrosis factor α

The enzyme 11β-hydroxysteroid dehydrogenase 1 (11β-HSD-1) is expressed in a number of tissues in rodents and humans and is responsible for the reactivation of inert cortisone into cortisol. Its gene expression and activity are increased in white adipose tissue (WAT) from obese humans and may contribute to the adverse metabolic consequences of obesity and the metabolic syndrome. The extent to which 11β-HSD-1 contributes to adipose tissue function in dogs is unknown; the aim of the present study was to examine 11β-HSD-1 gene expression and its regulation by proinflammatory and anti-inflammatory agents in canine adipocytes. Real-time PCR was used to examine the expression of 11β-HSD-1 in canine adipose tissue and canine adipocytes differentiated in culture. The mRNA encoding 11β-HSD-1 was identified in all the major WAT depots in dogs and also in liver, kidney, and spleen. Quantification by real-time PCR showed that 11β-HSD-1 mRNA was least in perirenal and falciform depots and greatest in subcutaneous, omental, and gonadal depots. Greater expression was seen in the omental depot in female than in male dogs (P=0.05). Gene expression for 11β-HSD-1 was also seen in adipocytes, from both subcutaneous and visceral depots, differentiated in culture; expression was evident throughout differentiation but was generally greatest in preadipocytes and during early differentiation, declining as cells progressed to maturity. The inflammatory mediators lipopolysaccharide and tumor necrosis factor α had a main stimulatory effect on 11β-HSD-1 gene expression in canine subcutaneous adipocytes, but IL-6 had no significant effect. Treatment with dexamethasone resulted in a significant time- and dose-dependent increase in 11β-HSD-1 gene expression, with greatest effects seen at 24 h (2 nM: approximately 4-fold; 20 nM: approximately 14-fold; P=0.010 for both). When subcutaneous adipocytes were treated with the peroxisome proliferator activated receptor γ agonist rosiglitazone, similar dose- and time-dependent effects were noted. However, no effects were seen when adipocytes from the gonadal WAT depot were treated with rosiglitazone. The induction of 11β-HSD-1 expression, by the pro-inflammatory cytokine tumor necrosis factor α and by lipopolysaccharide may have implications for the pathogenesis of obesity and its associated diseases in the dog.

Maternal prenatal undernutrition programs adipose tissue gene expression in adult male rat offspring under high-fat diet

Several studies have shown that maternal undernutrition leading to low birth weight predisposes offspring to the development of metabolic pathologies such as obesity. Using a model of prenatal maternal 70% food restriction diet (FR30) in rat, we evaluated whether postweaning high-fat (HF) diet would amplify the phenotype observed under standard diet. We investigated biological parameters as well as gene expression profile focusing on white adipose tissues (WAT) of adult offspring. FR30 procedure does not worsen the metabolic syndrome features induced by HF diet. However, FR30HF rats displayed catch-up growth to match the body weight of adult control HF animals, suggesting an increase of adiposity while showing hyperleptinemia and a blunted increase of corticosterone. Using quantitative RT-PCR array, we demonstrated that FR30HF rats exhibited leptin and Ob-Rb as well as many peptide precursor and receptor gene expression variations in WAT. We also showed that the expression of genes involved in adipogenesis was modified in FR30HF animals in a depot-specific manner. We observed an opposite variation of STAT3 phosphorylation levels, suggesting that leptin sensitivity is modified in WAT adult FR30 offspring. We demonstrated that 11β-HSD1, 11β-HSD2, GR, and MR genes are coexpressed in WAT and that FR30 procedure modifies gene expression levels, especially under HF diet. In particular, level variation of 11β-HSD2, whose protein expression was detected by Western blotting, may represent a novel mechanism that may affect WAT glucocorticoid sensitivity. Data suggest that maternal undernutrition differently programs the adult offspring WAT gene expression profile that may predispose for altered fat deposition.

Mechanisms behind early life nutrition and adult disease outcome

Obesity is increasing around the globe. While adult lifestyle factors undoubtedly contribute to the incidence of obesity and its attendant disorders, mounting evidence suggests that programming of obesity may occur following under- and over-nutrition during development. As hypothalamic control of appetite and energy expenditure is set early in life and can be perturbed by certain exposures such as undernutrition and altered metabolic and hormonal signals, in utero exposure to altered maternal nutrition and inadequate nutrition during early postnatal life may contribute to programming of obesity in offspring. Data from animal studies indicate both intrauterine and postnatal environments are critical determinants of the development of pathways regulating energy homeostasis. This review summarizes recent evidence of the impact of maternal nutrition as well as postnatal nutrition of the offspring on subsequent obesity and disease risk of the offspring. While much of the experimental work reviewed here was conducted in the rodent, these observations provide useful insights into avenues for future research into developing preventive measures to curb the obesity epidemic.

Human hydroxysteroid dehydrogenases and pre-receptor regulation: insights into inhibitor design and evaluation

Hydroxysteroid dehydrogenases (HSDs) represent a major class of NAD(P)(H) dependent steroid hormone oxidoreductases involved in the pre-receptor regulation of hormone action. This is achieved by HSDs working in pairs so that they can interconvert ketosteroids with hydroxysteroids resulting in a change in ligand potency for nuclear receptors. HSDs belong to two protein superfamilies the aldo-keto reductases and the short-chain dehydrogenase/reductases. In humans, many of the important enzymes have been thoroughly characterized including the elucidation of their three-dimensional structures. Because these enzymes play fundamental roles in steroid hormone action they can be considered to be drug targets for a variety of steroid driven diseases, e.g. metabolic syndrome and obesity, inflammation, and hormone dependent malignancies of the endometrium, prostate and breast. This article will review how fundamental knowledge of these enzymes can be exploited in the development of isoform specific HSD inhibitors from both protein superfamilies. Article from the Special issue on Targeted Inhibitors.

Evaluation of Hepatic 11 β-Hydroxysteroid Dehydrogenase Activity by Cortisone Acetate Test in Young Adults With Diabetes Mellitus Type 1

Cortisone acetate test was performed in twelve young adult patients with diabetes mellitus type 1, after dexamethasone administration to suppress endogenous cortisol production. Previous screening revealed that all of the subjects had peak cortisol responses in the range from subnormal to normal, as determined by a low-dose Synacthen test. The aim was to find out whether these patients would exhibit different conversion of cortisone to cortisol by 11β-hydroxysteroid dehydrogenase. Using multifactorial ANOVA the following significant relationships were obtained between cortisol or cortisol/cortisone ratio measured during the test and other parameters examined a) before dexamethasone suppression and b) during the test: a) Cortisol at 120th minute negatively correlated with daily insulin dose and positively with basal aldosterone. Cortisol/cortisone ratio at 60th, 120th, 180th, and 240th minute negatively correlated with basal aldosterone/plasma renin activity ratio, urinary free cortisol/24 hours and positively with basal dehydroepindrosterone sulphate. b) Cortisol at 120th minute negatively correlated with suppressed basal serum glycemia; cortisol/cortisone ratio during the whole test negatively correlated with supressed basal ACTH. The examination of peripheral metabolism of cortisol using cortisone acetate test in patients with diabetes mellitus type 1 showed adaptive changes of 11β-hydroxysteroid dehydrogenace activity associated with altered cortisol tissue supply.

Weight loss after gastric bypass surgery in women is followed by a metabolically favorable decrease in 11beta-hydroxysteroid dehydrogenase 1 expression in subcutaneous adipose tissue

BACKGROUND AND AIMS

The role of 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) in the pathogenesis of obesity has been elucidated in humans and in various rodent models. Obesity is accompanied by disturbances in glucocorticoid metabolism, circulating adipokine levels, and fatty acid (FA) reesterification. This study was undertaken to evaluate glucocorticoid metabolism in sc fat before and after weight loss and to explore putative associations between 11beta-HSD1 and leptin, adiponectin, and FA recycling.

SUBJECTS AND METHODS

Twenty-seven obese (mean body mass index 44.4 + or - 4.4 kg/m(2)) women underwent gastric bypass surgery. Subcutaneous fat biopsies were collected before and 2 yr after surgery. The expression of 11beta-HSD1, leptin, adiponectin, and phosphoenolpyruvate carboxykinase (PEPCK) mRNA was evaluated with real-time PCR. Serum leptin and adiponectin protein levels were estimated by ELISA.

RESULTS

Two years after gastric bypass surgery, significant reductions were observed in the mean body mass index (from 44.4 to 30.8 kg/m(2)) and mean waist circumference (from 121.9 to 90.6 cm). After weight loss, 11beta-HSD1 mRNA expression decreased 4-fold (P < 0.001). Both leptin and adiponectin mRNA expression decreased, with concomitantly decreased circulating leptin and increased circulating adiponectin levels. PEPCK mRNA expression did not change.

CONCLUSION

Weight loss after gastric bypass surgery was followed by metabolically favorable changes in insulin sensitivity, circulating leptin and adiponectin, and peripheral glucocorticoid metabolism. A significant reduction in 11beta-HSD1 expression was observed in sc adipose tissue after weight loss. This suggests that up-regulation of 11beta-HSD1 is a consequence, rather than a cause, of obesity.

Selective effects of PPARgamma agonists and antagonists on human pre-adipocyte differentiation

AIM

The insulin sensitizer rosiglitazone (RTZ) acts by activating peroxisome proliferator and activated receptor gamma (PPAR gamma), an effect accompanied in vivo in humans by an increase in fat storage. We hypothesized that this effect concerns PPARgamma(1) and PPARgamma(2) differently and is dependant on the origin of the adipose cells (subcutaneous or visceral). To this aim, the effect of RTZ, the PPARgamma antagonist GW9662 and lentiviral vectors expressing interfering RNA were evaluated on human pre-adipocyte models.

METHODS

Two models were investigated: the human pre-adipose cell line Chub-S7 and primary pre-adipocytes derived from subcutaneous and visceral biopsies of adipose tissue (AT) obtained from obese patients. Cells were used to perform oil-red O staining, gene expression measurements and lentiviral infections.

RESULTS

In both models, RTZ was found to stimulate the differentiation of pre-adipocytes into mature cells. This was accompanied by significant increases in both the PPARgamma(1) and PPARgamma(2) gene expression, with a relatively stronger stimulation of PPARgamma(2). In contrast, RTZ failed to stimulate differentiation processes when cells were incubated in the presence of GW9662. This effect was similar to the effect observed using interfering RNA against PPARgamma(2). It was accompanied by an abrogation of the RTZ-induced PPARgamma(2) gene expression, whereas the level of PPARgamma(1) was not affected.

CONCLUSIONS

Both the GW9662 treatment and interfering RNA against PPARgamma(2) are able to abrogate RTZ-induced differentiation without a significant change of PPARgamma(1) gene expression. These results are consistent with previous results obtained in animal models and suggest that in humans PPARgamma(2) may also be the key isoform involved in fat storage.

HPLC method for determination of fluorescence derivatives of cortisol, cortisone and their tetrahydro- and allo-tetrahydro-metabolites in biological fluids

11Beta-hydroxysteroid dehydrogenase isoform 2 (11beta-HSD2) is responsible for conversion of cortisol (F) to inactive cortisone (E). Disturbance of its activity can cause hypertension. To estimate 11beta-HSD2 activity, besides F and E, their tetrahydro- (THF, THE) as well allo-tetrahydro- (allo-THF, allo-THE) metabolites should be determined. This study describes HPLC-FLD method for the quantitative determination of endogenous glucocorticoids (GCs) in plasma and urine (total and free) and their metabolites in urine. Following extraction at pH 7.4 using dichloromethane, GCs (F, E, THF, allo-THF, THE, allo-THE and internal standard--prednisolone) were derivatized with 9-anthroyl nitrile and purified by SPE using C(18) cartridges. The enzymatic hydrolysis of conjugated steroids was provided using beta-glucuronidase. The influence of organic bases on 9-AN derivatization of steroids was investigated. The best yield of the derivatization was obtained in presence of the mixture of 10.0% triethylamine (TEA) and 0.1% quinuclidine (Q). Chromatographic separation was accomplished in the Chromolith RP-18e monolithic column. The elaborated method was validated. Calibration curves were linear in the ranges: for F, E and THF 5.0-1000.0 ng mL(-1), for allo-THF and THE + allo-THE 10.0-1000.0 ng mL(-1). LOD (S/N=3:1) for all analytes amounted 3.0 ng mL(-1). Recoveries of GCs exceeded 90%. The method was precise and accurate, intra- and inter-day precision were 3.0-12.1% and 9.2-14.0%, respectively. Accuracy ranged from 0.2 to 15.1%. The method was applied for estimating endogenous GCs in plasma and urine. Plasma levels of F and E were in the ranges: 133.0-174.5 ng mL(-1) and 17.4-35.9 ng mL(-1), respectively. Free urinary steroids were in the ranges: 12.0-54.1 microg/24 h (UFF) and 37.8-76.2 microg/24 h (UFE). The ratio of (THF + allo-THF)/(THE + allo-THE) amounted from 1.01 to 1.23. The obtained results confirmed utility of the elaborated method in the assessment of 11beta-HSD2 activity in man.

Insulin sensitization of human preadipocytes through glucocorticoid hormone induction of forkhead transcription factors

Glucocorticoids are synthesized locally in adipose tissue and contribute to metabolic disease through the facilitation of adipose tissue expansion. Here we report that exposure of human primary preadipocytes to glucocorticoids increases their sensitivity to insulin and enhances their subsequent response to stimuli that promote differentiation. This effect was observed in primary human preadipocytes but not in immortalized 3T3-L1 murine preadipocytes or in fully differentiated primary human adipocytes. Stimulation of insulin signaling was mediated through induction of insulin receptor (IR), IR substrate protein 1 (IRS1), IRS2, and the p85 regulatory subunit of phosphoinositide-3-3-kinase, which led to enhanced insulin-mediated activation of Akt. Although induction of IRS2 was direct, induction of IR and IRS1 by glucocorticoids occurred subsequent to primary induction of the forkhead family transcription factors FoxO1A and FoxO3A. These results reveal a new role for glucocorticoids in preparing preadipocytes for differentiation.

Obesity is accompanied by disturbances in peripheral glucocorticoid metabolism and changes in FA recycling

The glucocorticoid activating enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) is of major interest in obesity-related morbidity. Alterations in tissue-specific cortisol levels may influence lipogenetic and gluco/glyceroneogenetic pathways in fat and liver. We analyzed the expression and activity of 11betaHSD1 as well as the expression of phosphoenolpyruvate carboxykinase (PEPCK), sterol regulatory element binding protein (SREBP), and fatty acid synthase (FAS) in adipose and liver and investigated putative associations between 11betaHSD1 and energy metabolism genes. A total of 33 obese women (mean BMI 44.6) undergoing gastric bypass surgery were enrolled. Subcutaneous adipose tissue (SAT), omental fat (omental adipose tissue (OmAT)), and liver biopsies were collected during the surgery. 11betaHSD1 gene expression was higher in SAT vs. OmAT (P = 0.013), whereas the activity was higher in OmAT (P = 0.009). The SAT 11betaHSD1 correlated with waist circumference (P = 0.045) and was an independent predictor for the OmAT area in a linear regression model. Energy metabolism genes had AT depot-specific expression; higher leptin and SREBP in SAT than OmAT, but higher PEPCK in OmAT than SAT. The expression of 11betaHSD1 correlated with PEPCK in both AT depots (P = 0.05 for SAT and P = 0.0001 for OmAT). Hepatic 11betaHSD1 activity correlated negatively with abdominal adipose area (P = 0.002) and expression positively with PEPCK (P = 0.003). In human obesity, glucocorticoid regeneration in the SAT is associated with central fat accumulation indicating that the importance of this specific fat depot is underestimated. Central fat accumulation is negatively associated with hepatic 11betaHSD1 activity. A disturbance in peripheral glucocorticoid metabolism is associated with changes in genes involved in fatty acid (FA) recycling in adipose tissue (AT).

Cortisol secretion after adrenocorticotrophin (ACTH) and dexamethasone tests in healthy female and male dogs

Background

For the conclusive diagnosis of Cushing's Syndrome, a stimulating ACTH test or a low suppressive Dexamethasone test is used. Reports in other species than the dog indicate that plasma cortisol concentration after ACTH administration is affected by gender. We investigated the effect of gender on the cortisol response to ACTH and Dexamethasone tests in dogs.

Methods

Seven healthy adult Cocker Spaniels (4 females and 3 males) were assigned to a two by two factorial design: 4 dogs (2 females and 2 males) received IV Dexamethasone 0.01 mg/kg, while the other 3 dogs received an IV saline solution (control group). Two weeks later the treatments were reversed. After one month, ACTH was given IV (250 μg/animal) to 4 dogs (2 female and 2 males) while the rest was treated with saline solution (control group). Cortisol concentrations were determined by a direct solid-phase radioimmunoassay and cholesterol and triglycerides by commercial kits.

Results and Discussion

No effect of treatment was observed in metabolite concentrations, but females presented higher cholesterol concentrations. ACTH-treated dogs showed an increase in cortisol levels in the first hour after sampling until 3 hours post injection. Cortisol concentrations in Dexamethasone-treated dogs decreased one hour post injection and remained low for 3 hours, thereafter cortisol concentrations increased. The increase in cortisol levels from one to two hours post ACTH injection was significantly higher in females than males. In Dexamethasone-treated males cortisol levels decreased one hour post injection up to 3 hours; in females the decrease was more pronounced and prolonged, up to 5 hours post injection.

Conclusion

We have demonstrated that cortisol response to ACTH and Dexamethasone treatment in dogs differs according to sex.

Comparison of gene transcription between subcutaneous and visceral adipose tissue in Chinese adults

Obese individuals with fat stored in visceral adipose tissue (VAT) generally suffer greater adverse metabolic consequences than those with fat stored predominantly in subcutaneous adipose tissue (SAT), but its molecular basis is not completely understood. We isolated paired samples of SAT and VAT from 15 lean and 15 obese subjects and systematically compared the transcription level of genes that may determine fat distribution and metabolic sequelae between SAT and VAT using quantitative real-time PCR. We found that, leptin levels were lower in VAT than SAT, for both lean and obese subjects. In lean subjects, tumor necrosis factor-alpha (TNF-alpha) was expressed equally in both fat depots, while toll-like receptor 4 (TLR4) and glucocorticoid receptor (GR) showed significantly lower expression in VAT than SAT. In obese subjects, TNF-alpha and TLR4 expression were significantly higher in VAT than SAT, yet GR expression did not differ in these areas. For all subjects, VAT 11beta-hydroxysteroid dehydrogenate type 1 (11beta-HSD1) level was significantly correlated with BMI. GR expression level was significantly correlated with TLR4 expression level. Cultured adipocytes showed higher TLR4 mRNA level after differentiation, and higher TNF-alpha level after treatment with free fatty acids. These results suggest that there are depot-specific differences in leptin, TNF-alpha, TLR4 and GR transcriptions in humans. TLR4 signaling and higher 11beta-HSD1 and GR levels in VAT may contribute predominantly to inflammatory factor production and subsequent metabolic sequelae in obese human.

Cushing's syndrome: aftermath of the cure

Cushing's syndrome (CS) is a chronic and systemic disease caused by endogenous or exogenous hypercortisolism, associated with an increase of mortality rate due to the clinical consequences of glucocorticoid excess, especially cardiovascular diseases. After cure, usually obtained by the surgical removal of the tumor responsible for the disease, the normalization of cortisol secretion is not constantly followed by the recovery of the clinical complications developed during the active disease, and it is often followed by the development of novel clinical manifestations induced by the fall of cortisol levels. These evidences were mostly documented in patients with pituitary-dependent CS, after surgical resection of the pituitary tumor. Indeed, despite an improvement of the mortality rate, metabolic syndrome and the consequent cardiovascular risk have been found to partially persist after disease remission, strictly correlated to the insulin resistance. Skeletal diseases, mainly osteoporosis, improve after normalization of cortisol levels but require a long period of time or the use of specific treatment, mainly bisphosphonates, to reach the normalization of bone mass. A relevant improvement or resolution of mental disturbances has been described in patients cured from CS, although in several cases, cognitive decline persisted and psychological or psychiatric improvement was erratic, delayed, or incomplete. On the other hand, development or exacerbation of autoimmune disorders, mainly thyroid autoimmune diseases, was documented in predisposed patients with CS after disease remission. The totality of these complications persisting or occurring after successful treatment contribute to the impairment of quality of life registered in patients with CS after disease cure.