Depot-specific messenger RNA expression of 11β-hydroxysteroid dehydrogenase type 1 and leptin in adipose tissue of children and adults

Increased systemic and adipose 11β-HSD1 activity in idiopathic intracranial hypertension

Context

Idiopathic intracranial hypertension (IIH) is a disease of raised intracranial pressure (ICP) of unknown etiology. Reductions in glucocorticoid metabolism are associated with improvements in IIH disease activity. The basal IIH glucocorticoid metabolism is yet to be assessed.

Objective

The objective of this study was to determine the basal glucocorticoid phenotype in IIH and assess the effects of weight loss on the IIH glucocorticoid phenotype.

Design

A retrospective case-control study and a separate exploratory analysis of a prospective randomized intervention study were carried out.

Methods

The case-control study compared female IIH patients to BMI, age, and sex-matched controls. In the randomized intervention study, different IIH patients were randomized to either a community weight management intervention or bariatric surgery, with patients assessed at baseline and 12 months. Glucocorticoid levels were determined utilizing 24-h urinary steroid profiles alongside the measurement of adipose tissue 11β-HSD1 activity.

Results

Compared to control subjects, patients with active IIH had increased systemic 11β-hydroxysteroid dehydrogenase (11β-HSD1) and 5α-reductase activity. The intervention study demonstrated that weight loss following bariatric surgery reduced systemic 11β-HSD1 and 5α-reductase activity. Reductions in these were associated with reduced ICP. Subcutaneous adipose tissue explants demonstrated elevated 11β-HSD1 activity compared to samples from matched controls.

Conclusion

The study demonstrates that in IIH, there is a phenotype of elevated systemic and adipose 11β-HSD1 activity in excess to that mediated by obesity. Bariatric surgery to induce weight loss was associated with reductions in 11β-HSD1 activity and decreased ICP. These data reflect new insights into the IIH phenotype and further point toward metabolic dysregulation as a feature of IIH.

Altered glucocorticoid metabolism in girls with central obesity

BACKGROUND

Dysregulation of glucocorticoid metabolism is known to be a causative factor of obesity. However, only a few studies have evaluated the enzymatic activities involved in glucocorticoid metabolism in the pediatric population.

OBJECTIVE

To examine whether circulating glucocorticoid metabolites and their ratios reflecting the activities of metabolic enzyme are associated with obesity and body composition in girls.

METHODS

A total of 227 girls aged 7-13 years (131 control, 45 overweight, 51 obese) were enrolled in this study. Serum concentrations of glucocorticoids (11-deoxycortisol, cortisol, tetrahydrocortisol [THF], allo-THF, allo-dihydrocortisol [allo-DHF], and cortisone) were evaluated by gas chromatography-mass spectrometry. Enzyme activities corresponding to the ratios of cortisol and cortisone to their respective precursors and metabolites were also assessed.

RESULTS

Serum levels of allo-THF were significantly higher in obese girls compared with those in overweight and control girls (P = 0.018); however, concentrations of other cortisol metabolites were not significantly different between the groups studied. According to the severity of obesity, increasing trends in the metabolic ratios reflecting the activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) [(cortisol + allo-DHF + allo-THF + THF)/cortisone], relative 5α/5β-reductase [allo-THF/THF] activity, and 3α-HSD [allo-THF/allo-DHF] activity, were noted (P-for-trend <0.05). Body fat percentage and waist-to-height ratio positively correlated with the activities of 11β-HSD1 and 3α-HSD (P < 0.05). Following covariate control, girls with central obesity demonstrated significantly higher metabolic ratios reflecting 11β-HSD1, relative 5α/5β-reductase, and 3α-HSD activities (P < 0.05).

CONCLUSIONS

We found an altered glucocorticoid metabolism suggesting increased production of cortisol by 11β-HSD1 and increased metabolic clearance of cortisol catalyzed by 3α-HSD in girls with central obesity.

Inflammation in Obesity-Related Complications in Children: The Protective Effect of Diet and Its Potential Role as a Therapeutic Agent

Obesity is a growing health problem in both children and adults, impairing physical and mental state and impacting health care system costs in both developed and developing countries. It is well-known that individuals with excessive weight gain frequently develop obesity-related complications, which are mainly known as Non-Communicable Diseases (NCDs), including cardiovascular disease, type 2 diabetes mellitus, metabolic syndrome, non-alcoholic fatty liver disease, hypertension, hyperlipidemia and many other risk factors proven to be associated with chronic inflammation, causing disability and reduced life expectancy. This review aims to present and discuss complications related to inflammation in pediatric obesity, the critical role of nutrition and diet in obesity-comorbidity prevention and treatment, and the impact of lifestyle. Appropriate early dietary intervention for the management of pediatric overweight and obesity is recommended for overall healthy growth and prevention of comorbidities in adulthood.

Differences in Neuregulin 4 Expression in Children: Effects of Fat Depots and Obese Status

PURPOSE

To observe the expression of Nrg4, uncoupling protein-1 (UCP1), tumor necrosis factor α (TNFα), CD31, VE-cadherin/CDH5 and vascular endothelial growth factor A (VEGF-A) mRNA in abdominal subcutaneous (SC), omental (OM) adipose tissue in children with relation to anthropometric parameters. Further to verify the effect of inflammatory mediators on Nrg4 and UCP1 mRNA expression in adipocytes.

METHODS

Paired SC and OM adipose tissues were obtained from 58 children. In vitro, the adipocytes isolated from primary inguinal adipose tissue of mice were treated with TNFα (50 ng/ml) for 12-48 h. mRNA levels of Nrg4, UCP1 and TNFα were determined by real-time PCR.

RESULTS

Nrg4, UCP1, VEGF-A and CDH5 mRNA levels in SC were significantly higher than those in OM adipose tissue and the mRNA level of TNFα showed the opposite result. Moreover, Nrg4 and UCP1 mRNA in SC were significantly lower in overweight children compared to normal weight children. Nrg4 in SC and OM was negatively associated with BMISDS, WHtR. CDH55 mRNA in OM was negatively associated with WHR. VEGF-A was positively correlated with Nrg4 in SC. In vitro, Nrg4 and UCP1 mRNA levels in adipocytes were dose- and time-dependently decreased under TNFα treatment.

CONCLUSIONS

Nrg4, UCP1, VEGF-A and CDH5 mRNA expression in adipose tissues display a depot-specific pattern. Nrg4 mRNA levels in adipose tissue are decreased with obesity and associated with WAT browning and angiogenesis. TNFα may be involved in the regulation of Nrg4 level in adipose tissue, which may be one of the causes of the down-regulation of Nrg4 expression in obesity with chronic inflammatory response.

Intra-abdominal sepsis--epidemiology, aetiology and management

Peritonitis is a progressive disease leading inexorably from local peritoneal irritation to overwhelming sepsis and death unless this trajectory is interrupted by timely and effective therapy. In children peritonitis is usually secondary to intraperitoneal disease, the nature of which varies around the world. In rich countries, appendicitis is the principal cause whilst in poor countries diseases such as typhoid must be considered in the differential diagnosis. Where resources are limited, the clinical diagnosis of peritonitis mandates laparotomy for diagnosis and source control. In regions with unlimited resources, radiological investigation, ultrasound, CT scan or MRI may be used to select patients for non-operative management. For patients with appendicitis, laparoscopic surgery has achieved results comparable to open operation; however, in many centres open operation remains the standard. In complicated peritonitis "damage control surgery" may be appropriate wherein source control is undertaken as an emergency with definitive repair or reconstruction awaiting improvement in the patient's general condition. Awareness of abdominal compartment syndrome is essential. Primary peritonitis in rich countries is seen in high-risk groups, such as steroid-dependent nephrotic syndrome patients, whilst in poor countries the at-risk population is less well defined and the diagnosis is often made at surgery.

The environmental obesogen bisphenol A promotes adipogenesis by increasing the amount of 11β-hydroxysteroid dehydrogenase type 1 in the adipose tissue of children

BACKGROUND

Bisphenol A (BPA) is considered as an environmental obesogen. The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts the inactive hormone cortisone to the active hormone cortisol in adipose tissues and promotes adipogenesis.

OBJECTIVE

To examine whether environmentally relevant concentrations of BPA could increase the expression of 11β-HSD1, as well as that of the adipogenesis-related genes peroxisome proliferator-activated receptor-γ (PPAR-γ) and lipoprotein lipase (LPL), in the adipose tissue of children.

METHODS

Omental fat biopsies were obtained from 17 children (7 boys and 10 girls between 3 and 13 years of age) undergoing abdominal surgery. The effects of BPA (10 nM, 1 μM, and 80 μM) on 11β-HSD1, PPAR-γ and LPL mRNA expression, and 11β-HSD1 enzymatic activity in adipose tissue and adipocytes were assessed in vitro. Moreover, the effects of carbenoxolone (CBX), an 11β-HSD1 inhibitor, or RU486, a glucocorticoid (GC) receptor antagonist, on 11β-HSD1, PPAR-γ and LPL mRNA expression were assessed in human visceral preadipocytes and adipocytes.

RESULTS

BPA, even at the lowest concentration tested (10 nM), increased the mRNA expression and enzymatic activity of 11β-HSD1 in the omental adipose tissue samples and the visceral adipocytes. Similar effects on PPAR-γ and LPL mRNA expression and lipid accumulation were observed in the adipocytes. CBX treatment inhibited the stimulatory effects of BPA (at 10 nM) on PPAR-γ and LPL mRNA expression, whereas RU486 inhibited 11β-HSD1 mRNA expression in the adipocytes.

CONCLUSION

BPA, at environmentally relevant levels, increased the mRNA expression and enzymatic activity of 11β-HSD1 by acting upon a GC receptor, which may lead to the acceleration of adipogenesis.

Is there sufficient evidence to consider the use of 11β-hydroxysteroid dehydrogenase type 1 inhibition in children?

Manifestations of the metabolic syndrome [obesity, dyslipidaemia, hypertension, blood glucose derangements including prediabetes or type 2 diabetes mellitus (T2DM)] in juvenile populations are becoming increasingly prevalent throughout the world and are at the point of being a global public health concern. Derangements in cortisol regeneration seem to be involved in the pathophysiology. Treatment with selective 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) inhibitors could be a therapeutic strategy in paediatric patients with manifestations of the metabolic syndrome. Based on preclinical and clinical data regarding development of the 11β-HSD1 enzyme, it appears that maturation occurs within the first year of life. Different changes in biomarkers for assessing the efficacy and safety of 11β-HSD1 inhibitors are to be expected in paediatric patients compared to adults, reflecting differences in metabolism. The effect of 11β-HSD1 treatment in children on bone differentiation and development as well as adrenocorticotropic hormone (ACTH), circulating and local cortisol tissue concentrations, androgens and respective stress response is not yet known. Based on current literature, the concept of inhibition of 11β-HSD1 is considered a potentially effective mean to regulate local cortisol levels in the paediatric population, and 11β-HSD1 inhibitors may provide a valuable target and treatment option for the metabolic syndrome in paediatric patients. However, the uncertainty over effects on the developing skeleton combined with mild increases in adrenal androgen levels raises potential concerns regarding growth as well as onset of puberty as to their future use in children. Future clinical studies are needed to thoroughly assess the risks and benefits of this new class of drugs in the paediatric population.

Neonatal overfeeding induced by small litter rearing causes altered glucocorticoid metabolism in rats

Elevated glucocorticoid (GC) activity may be involved in the development of the metabolic syndrome. Tissue GC exposure is determined by the tissue-specific GC-activating enzyme 11β-hydroxysteriod dehydrogenase type 1 (11β-HSD1) and the GC-inactivating enzyme 5α-reductase type 1 (5αR1), as well as 5β-reductase (5βR). Our aim was to study the effects of neonatal overfeeding induced by small litter rearing on the expression of GC-regulating enzymes in adipose tissue and/or liver and on obesity-related metabolic disturbances during development. Male Sprague-Dawley rat pup litters were adjusted to litter sizes of three (small litters, SL) or ten (normal litters, NL) on postnatal day 3 and then given standard chow from postnatal week 3 onward (W3). Small litter rearing induced obesity, hyperinsulinemia, and higher circulating corticosterone in adults. 11β-HSD1 expression and enzyme activity in retroperitoneal, but not in epididymal, adipose tissue increased with postnatal time and peaked at W5/W6 in both groups before declining. From W8, 11β-HSD1 expression and enzyme activity levels in retroperitoneal fat persisted at significantly higher levels in SL compared to NL rats. Hepatic 11β-HSD1 enzyme activity in SL rats was elevated from W3 to W16 compared to NL rats. Hepatic 5αR1 and 5βR expression was higher in SL compared to NL rats after weaning until W6, whereupon expression decreased in the SL rats and remained similar to that in NL rats. In conclusion, small litter rearing in rats induced peripheral tissue-specific alterations in 11β-HSD1 expression and activity and 5αR1 and 5βR expression during puberty, which could contribute to elevated tissue-specific GC exposure and aggravate the development of metabolic dysregulation in adults.

An early inflammatory gene profile in visceral adipose tissue in children

The aim of this study was to characterize expression profiles of visceral and subcutaneous adipose tissue in children. Adipose tissue samples were collected from children having elective surgery (n = 71, [54 boys], 6.0 ± 4.3 years). Affymetrix microarrays (n = 20) were performed to characterize the functional profile and identify genes of interest in adipose tissue. Visceral adipose tissue had an overrepresentation of Gene Ontology themes related to immune and inflammatory responses and subcutaneous adipose tissue had an overrepresentation of themes related to adipocyte growth and development. Likewise, qPCR performed in the whole cohort showed a 30-fold increase in haptoglobin (P = 0.005), 7-fold increase in IL-10 (P < 0.001), 8-fold decrease in VEGF (P = 0.01) and a 28-fold decrease in TBOX15 (P < 0.001) in visceral compared to subcutaneous adipose tissue. The inflammatory pattern in visceral adipose tissue may represent an early stage of the adverse effects of this depot, and combined with chronic obesity, may contribute to increased metabolic and cardiovascular risk.

Expression of 11β-hydroxysteroid dehydrogenase type 1 in visceral and subcutaneous adipose tissues of patients with polycystic ovary syndrome is associated with adiposity

Polycystic ovary syndrome (PCOS) is characterized by insulin resistance (IR) and central obesity. The impact of adipose tissue cortisol reactivation by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) on markers of obesity and IR was assessed in PCOS patients. Eighty-five PCOS patients and 43 controls were enrolled for subcutaneous adipose tissue biopsy; 25/85 patients and 29/43 controls underwent also visceral adipose tissue biopsy. HSD11B1 gene expression and expression of lipid metabolism genes were measured in subcutaneous and visceral adipose tissues. Anthropometric and biochemical markers of IR and PCOS were also assessed. HSD11B1 expression in visceral and subcutaneous adipose tissue was increased in PCOS patients compared to controls (p<0.05). After BMI adjustment, the difference was no longer significant. In PCOS patients, visceral HSD11B1 expression correlated positively with waist circumference (p=0.001), BMI (p=0.002), plasma insulin (p<0.05), systolic blood pressure (p=0.003), and lipoprotein lipase (LPL), hormone-sensitive lipase (LIPE) and peroxisome-proliferator activated receptor γ gene expression. Subcutaneous HSD11B1 expression correlated positively with BMI, waist circumference (p<0.001 for both) and HOMA-IR (p=0.003), and negatively with LPL, LIPE, adiponectin and glucose transporter GLUT4 gene expression. HSD11B1 expression in both depots showed a negative correlation with plasma HDL-cholesterol (p<0.03) and a positive one with C-reactive protein (p<0.001). In multiple regression analysis, HSD11B1 expression in visceral adipose tissue was most prominently associated with waist circumference, and that in subcutaneous adipose tissue with BMI (p<0.001 for both). Our results show that PCOS is not associated with increased HSD11B1 expression once adiposity is controlled for. Increased expression of this gene correlates with markers of adiposity and predicts IR and an unfavorable metabolic profile, independently of PCOS.

Cerebrospinal fluid corticosteroid levels and cortisol metabolism in patients with idiopathic intracranial hypertension: a link between 11beta-HSD1 and intracranial pressure regulation?

CONTEXT

The etiology of idiopathic intracranial hypertension (IIH) is unknown. We hypothesized that obesity and elevated intracranial pressure may be linked through increased 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity.

OBJECTIVE

The aim was to characterize 11β-HSD1 in human cerebrospinal fluid (CSF) secretory [choroid plexus (CP)] and drainage [arachnoid granulation tissue (AGT)] structures, and to evaluate 11β-HSD1 activity after therapeutic weight loss in IIH.

DESIGN AND SETTING

We conducted in vitro analysis of CP and AGT and a prospective in vivo cohort study set in two tertiary care centers.

PATIENTS OR OTHER PARTICIPANTS

Twenty-five obese adult female patients with active IIH were studied, and 22 completed the study.

INTERVENTION

Fasted serum, CSF, and 24-h urine samples were collected at baseline, after 3-month observation, and after a 3-month diet.

MAIN OUTCOME MEASURES

Changes in urine, serum, and CSF glucocorticoids (measured by gas chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry) after weight loss were measured.

RESULTS

11β-HSD1 and key elements of the glucocorticoid signaling pathway were expressed in CP and AGT. After weight loss (14.2±7.8 kg; P<0.001), global 11β-HSD1 activity decreased (P=0.001) and correlated with reduction in intracranial pressure (r=0.504; P=0.028). CSF and serum glucocorticoids remained stable, although the change in CSF cortisone levels correlated with weight loss (r=-0.512; P=0.018).

CONCLUSIONS

Therapeutic weight loss in IIH is associated with a reduction in global 11β-HSD1 activity. Elevated 11β-HSD1 may represent a pathogenic mechanism in IIH, potentially via manipulation of CSF dynamics at the CP and AGT. Although further clarification of the functional role of 11β-HSD1 in IIH is needed, our results suggest that 11β-HSD1 inhibition may have therapeutic potential in IIH.

Localization, age- and site-dependent expression, and regulation of 11β-hydroxysteroid dehydrogenase type 1 in skin

Glucocorticoids (GCs) are highly detrimental to skin integrity and function both when applied topically for anti-inflammatory treatments and during conditions of circulating excess, e.g., Cushing's syndrome. Within target tissues, GC availability is regulated at a prereceptor level, independently of systemic levels, by isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD) that interconvert active cortisol and inactive cortisone. Many of the adverse effects of GCs on skin are also reminiscent of the natural aging process. 11β-HSD1 (which activates cortisol), but not 11β-HSD2 (which inactivates cortisol), was expressed in epidermal keratinocytes and dermal fibroblasts in human skin and also in outer hair follicle root sheath cells in murine skin. 11β-HSD1 activity was present ex vivo in both species and increased with age in human skin tissue explants. In primary human dermal fibroblasts (HDF) from both photoprotected and photoexposed sites, 11β-HSD1 also increased with donor age. Additionally, photoexposed HDF displayed higher 11β-HSD1 mRNA expression than donor-matched photoprotected HDF. GC treatment of HDF caused upregulation of 11β-HSD1 mRNA levels independent of donor age or site. The age- and site-associated increase in dermal 11β-HSD1, and the ensuing increased local GC activation, may contribute to the adverse changes in skin morphology and function associated with chronological aging and photoaging.

Testosterone stimulates adipose tissue 11beta-hydroxysteroid dehydrogenase type 1 expression in a depot-specific manner in children

CONTEXT

Activation of the enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) in adipose tissue results in the production of excess tissue glucocorticoids and the induction of adiposity and visceral obesity in particular. Androgens may affect body fat distribution by regulating the local metabolism of cortisol.

OBJECTIVE

Our objective was to study 11beta-HSD1 mRNA expression in abdominal sc and omental (om) adipose tissue in children after in vitro testosterone and cortisol treatment.

SUBJECTS AND METHODS

Paired fat biopsies (sc and om) were obtained from 19 boys (age 6-14 yr, body mass index 14.6-25.3 kg/m(2), BMI sd score SDS -1.6-3.1) undergoing open abdominal surgery. Pieces of adipose tissue were incubated with testosterone, cortisol, or both hormones for 24 h, whereupon mRNA expression of 11beta-HSD1 and hexose-6-phosphate dehydrogenase (H6PDH) were measured by real-time PCR, and 11beta-HSD1 enzyme activity was determined.

RESULTS

Testosterone treatment up-regulated 11beta-HSD1 mRNA expression compared with control incubations in the absence of testosterone (P < 0.05) in om adipose tissue. Testosterone and cortisol both increased 11beta-HSD1 mRNA expression in om but not sc adipose tissue in a depot-specific manner by 2.5- and 2.9-fold, respectively (P < 0.001). However, there was no synergistic effect of the two hormones. 11beta-HSD1 enzyme activity correlated positively to mRNA expression (r = 0.610; P = 0.001). Adipose tissue mRNA expression of H6PDH was affected in a similar fashion to 11beta-HSD1 after hormonal treatment.

CONCLUSIONS

Testosterone and cortisol stimulated 11beta-HSD1 and H6PDH mRNA expression and 11beta-HSD1 activity in om but not in sc adipose tissue. This suggests that these hormones may contribute to fat distribution and accumulation during childhood.

Expression of inflammatory molecules and associations with BMI in children

BACKGROUND

Adipose tissue secrets several adipokines that have been proposed to be enrolled in many inflammatory pathways. Our aim was to investigate the adipokine expression in adipose tissue and peripheral blood mononuclear cells (PBMCs) in children.

MATERIALS AND METHODS

Thirty-one (17 males and 14 females) healthy children aged 10.9 +/- 1.8 years with a body mass index (BMI) of 19.3 +/- 3.5 kg m(-2) were enrolled. Adipokines (TNF-alpha, IL-6 and leptin) gene expression was quantified by real-time quantitative PCR in adipose tissue and PBMCs from the same children. Their serum levels were also measured.

RESULTS

BMI was positively correlated with leptin gene expression in adipose tissue and with leptin serum levels (beta = 0.476, P = 0.006 and beta = 0.576, P = 0.003 respectively). Leptin's serum levels were positively correlated with leptin gene expression in adipose tissue (beta = 0.462, P = 0.02). Adipose tissue gene expression of leptin and TNF-alpha and serum leptin and TNF-alpha serum levels were positively correlated (beta = 0.752, P < 0.001, beta = 0.311 and P = 0.015 respectively). In PBMCs, a positive correlation between TNF-alpha and IL-6 expression was found (beta = 0.526, P = 0.042).

CONCLUSION

We demonstrated powerful correlations of adipokines gene expression in adipose tissue and PBMCs in children, underlying that these molecules share common pathways related to childhood obesity.

Obesity and low-grade inflammation: a paediatric perspective

Childhood obesity is a major public health problem. Low-grade inflammation, a hallmark characterizing adult obesity, may be a pivotal mechanism linking obesity to its numerous systemic complications, with adipose tissue depots secreting and producing inflammatory mediators and visceral fat displaying an increased inflammatory profile. While knowledge is relatively scarce regarding the importance of the adipose tissue inflammation process in children, identifying its contribution in childhood obesity and the associated influences of age, sex, weight status, growth, and adipose depot phenotypes are crucial for understanding physiopathology and implementing early intervention strategies. We review the latest research linking obesity and inflammation in childhood focusing on serum inflammatory markers and the effectiveness of lifestyle interventions in improving systemic inflammation. Generally, there are significant correlations between body mass index and increased c-reactive protein and decreased adiponectin levels in children; these levels tend to be improved in interventions resulting in approximately 5% weight loss, regardless of the type or length of intervention. There is a need for further research measuring other inflammatory mediators (e.g. tumour necrosis factor (TNF)-alpha, IL-6, IL-8) and histological studies examining immune cell infiltration in adipose tissue depots in obese children.

Tissue-specific increases in 11beta-hydroxysteroid dehydrogenase type 1 in normal weight postmenopausal women

With age and menopause there is a shift in adipose distribution from gluteo-femoral to abdominal depots in women. Associated with this redistribution of fat are increased risks of type 2 diabetes and cardiovascular disease. Glucocorticoids influence body composition, and 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) which converts inert cortisone to active cortisol is a putative key mediator of metabolic complications in obesity. Increased 11βHSD1 in adipose tissue may contribute to postmenopausal central obesity. We hypothesized that tissue-specific 11βHSD1 gene expression and activity are up-regulated in the older, postmenopausal women compared to young, premenopausal women. Twenty-three pre- and 23 postmenopausal, healthy, normal weight women were recruited. The participants underwent a urine collection, a subcutaneous adipose tissue biopsy and the hepatic 11βHSD1 activity was estimated by the serum cortisol response after an oral dose of cortisone. Urinary (5α-tetrahydrocortisol+5β-tetrahydrocortisol)/tetrahydrocortisone ratios were higher in postmenopausal women versus premenopausal women in luteal phase (P<0.05), indicating an increased whole-body 11βHSD1 activity. Postmenopausal women had higher 11βHSD1 gene expression in subcutaneous fat (P<0.05). Hepatic first pass conversion of oral cortisone to cortisol was also increased in postmenopausal women versus premenopausal women in follicular phase of the menstrual cycle (P<0.01, at 30 min post cortisone ingestion), suggesting higher hepatic 11βHSD1 activity. In conclusion, our results indicate that postmenopausal normal weight women have increased 11βHSD1 activity in adipose tissue and liver. This may contribute to metabolic dysfunctions with menopause and ageing in women.

The development and endocrine functions of adipose tissue

White adipose tissue is a mesenchymal tissue that begins developing in the fetus. Classically known for storing the body's fuel reserves, adipose tissue is now recognized as an endocrine organ. As such, the secretions from adipose tissue are known to affect several systems such as the vascular and immune systems and play major roles in metabolism. Numerous studies have shown nutrient or hormonal manipulations can greatly influence adipose tissue development. In addition, the associations between various disease states, such as insulin resistance and cardiovascular disease, and disregulation of adipose tissue seen in epidemiological and intervention studies are great. Evaluation of known adipokines suggests these factors secreted from adipose tissue play roles in several pathologies. As the identification of more adipokines and determination of their role in biological systems, and the interactions between adipocytes and other cells types continues, there is little doubt that we will gain a greater appreciation for a tissue once thought to simply store excess energy.

Expression of cortisol metabolism-related genes shows circadian rhythmic patterns in human adipose tissue

OBJECTIVE

To analyze, in morbid obese patients, the expression of several human genes regulating cortisol metabolism, such as glucocorticoid receptor (GR), 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1), 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2), stearoyl-acute regulatory protein (StAR), 5alpha-reductase type I (5alpha-R) and peroxisome proliferator-activated receptor-gamma (PPARgamma) in two different adipose depots. A second objective was to characterize the circadian rhythmicity of these genes in both adipose tissue (AT) regions.

DESIGN

Visceral and subcutaneous abdominal AT biopsies were obtained from obese patients (body mass index >or=40 kg m(-2)). To carry out rhythmic expression analysis, AT explants were cultured for 24 h and gene expression at times (T) 0, 6, 12 and 18 h, was performed with quantitative real-time PCR.

RESULT

GR, 11betaHSD1 and PPARgamma genes were highly expressed in both subcutaneous and visceral depots. StAR and 5alpha-R genes were detected at lower levels. The expression of 11betaHSD2 was quantified in both AT depots with a higher expression in the visceral depot (P=0.032). Both sexes had similar gene expression levels, except for 5alpha-R (P=0.002). The genes studied showed circadian rhythmicity being more robust in visceral than in subcutaneous AT. Genes ranged in anti-phase between both depots (P=0.002). This rhythmicity was maintained in an AT culture.

CONCLUSION

We have shown for the first time circadian rhythmicity in glucocorticoid-related gene expression in human AT ex vivo. These results may have potential therapeutic implications with respect to the pathogenesis and treatment of diseases, such as obesity, type 2 diabetes and cardiovascular diseases.

Adiponectin and peroxisome proliferator-activated receptor gamma expression in subcutaneous and omental adipose tissue in children

AIM

To compare the expression levels of the adiponectin and peroxisome proliferator -activated receptor gamma (PPARgamma) genes in subcutaneous adipose tissue (SC) and omental adipose tissue (OM) in children with relation to age and anthropometric variables.

METHODS

Paired biopsies (SC and OM) were obtained from 53 children (age 0.2-14 years, BMI 12.5-25.8 kg/m(2)). Adiponectin and PPARgamma mRNA levels in adipose tissue were measured by real-time PCR.

RESULTS

In overweight, but not in normal weight children, the median adiponectin mRNA level was significantly lower in OM [0.51 (0.1-2.17)] compared to SC [1.29 (0.16-5.08)], (p = 0.03). Adiponectin mRNA levels were strongly associated with PPARgamma mRNA levels in both SC (r = 0.73, p < 0.001) and OM (r = 0.78, p < 0.001).

CONCLUSIONS

The lower adiponectin expression in OM relative to SC in overweight children indicates that metabolic-endocrine alterations begin already in childhood. The close association between adiponectin and PPARgamma expression supports the hypothesis this transcription factor is involved in adiponectin gene regulation.