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Thermogenesis in brown adipose tissue (BAT) is fundamental to energy balance and is also relevant for humans. Bone morphogenetic proteins (BMPs) regulate adipogenesis, and, here, we describe a role for BMP8B in the direct regulation of thermogenesis. BMP8B is induced by nutritional and thermogenic factors in mature BAT, increasing the response to noradrenaline through enhanced p38MAPK/CREB signaling and increased lipase activity. Bmp8b(-/-) mice exhibit impaired thermogenesis and reduced metabolic rate, causing weight gain despite hypophagia. BMP8B is also expressed in the hypothalamus, and Bmp8b(-/-) mice display altered neuropeptide levels and reduced phosphorylation of AMP-activated protein kinase (AMPK), indicating an anorexigenic state. Central BMP8B treatment increased sympathetic activation of BAT, dependent on the status of AMPK in key hypothalamic nuclei. Our results indicate that BMP8B is a thermogenic protein that regulates energy balance in partnership with hypothalamic AMPK. BMP8B may offer a mechanism to specifically increase energy dissipation by BAT., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Unlabelled: Low-carbohydrate, high-fat (LC-HF) diets are popular for inducing weight loss in overweighed adults. Adaptive thermogenesis increased by specific effects of macronutrients on energy expenditure has been postulated to induce this weight loss. We studied brown adipose tissue (BAT) morphology and function following exposure to different LC-HF diets., Methods: Male Wistar rats were fed a standard control diet ad libitum or pair-fed isoenergetic amounts of three experimental diets for 4 weeks. The diets had the following macronutrient composition (% metabolizable energy: carbohydrates, fat, protein): control (64.3/16.7/19), LC-HF-low protein (LC-HF-LP, 1.7/92.8/5.5), LC-HF-normal-protein (LC-HF-NP, 2.2/78.7/19.1), and a high fat diet with carbohydrates ("high fat", 19.4/61.9/18.7)., Results: Body weight gain was reduced in all pair-fed experimental groups as compared to rats fed the control diet, with more pronounced effect in rats on LC-HF diets than on the high fat diet with carbohydrates. High fat diets increased expression of PGC1α and ADRB3 in BAT indicating higher SNS outflow. However, UCP1 mRNA expression and expression of UCP1 assessed by immunohistochemistry was not different between diet groups. In accordance, analysis of mitochondrial function in-vitro by extracellular flux analyser (Seahorse Bioscience) and measurement of inducible thermogenesis in vivo (primary endpoint), explored by indirect calorimetry following norepinephrine injection, did not show significant differences between groups. Histology of BAT revealed increased lipid droplet size in rats fed the high-fat diet and both LC-HF diets., Conclusion: All experimental diets upregulated expression of genes which are indicative for increased BAT activity. However, the functional measurements in vivo revealed no increase of inducible BAT thermogenesis. This indicates that lower body weight gain with LC-HF diets and a high fat diet in a pair-feeding setting is not caused by increased adaptive thermogenesis in BAT.

Mice lacking Peroxisome Proliferator-Activated Receptor γ2 (PPARγ2) have unexpectedly normal glucose tolerance and mild insulin resistance. Mice lacking PPARγ2 were found to have elevated levels of Lipocalin prostaglandin D synthase (L-PGDS) expression in BAT and subcutaneous white adipose tissue (WAT). To determine if induction of L-PGDS was compensating for a lack of PPARγ2, we crossed L-PGDS KO mice to PPARγ2 KO mice to generate Double Knock Out mice (DKO). Using DKO mice we demonstrated a requirement of L-PGDS for maintenance of subcutaneous WAT (scWAT) function. In scWAT, DKO mice had reduced expression of thermogenic genes, the de novo lipogenic program and the lipases ATGL and HSL. Despite the reduction in markers of lipolysis in scWAT, DKO mice had a normal metabolic rate and elevated serum FFA levels compared to L-PGDS KO alone. Analysis of intra-abdominal white adipose tissue (epididymal WAT) showed elevated expression of mRNA and protein markers of lipolysis in DKO mice, suggesting that DKO mice may become more reliant on intra-abdominal WAT to supply lipid for oxidation. This switch in depot utilisation from subcutaneous to epididymal white adipose tissue was associated with a worsening of whole organism metabolic function, with DKO mice being glucose intolerant, and having elevated serum triglyceride levels compared to any other genotype. Overall, L-PGDS and PPARγ2 coordinate to regulate carbohydrate and lipid metabolism.

A comprehensive theory of linear vibronic coupling in a coupled manifold of Frenkel and charge-transfer states in an infinite molecular crystal is presented and applied for sexithiophene. The approach, valid in the intermediate-coupling regime, includes up to three-particle terms of the Philpott expansion, with the vibronic wavefunctions represented in the Lang-Firsov basis. As a stringent test, the scheme is used to reproduce the complete set of available sexithiophene absorption and electroabsorption spectra within a unified theoretical framework. The input is based primarily on independent calculations and to some extent on independent experiments, with explicit fitting contained within the limits set by the estimated inherent errors of a priori parameter estimates. Reasonably good quantitative agreement with experimental spectra is achieved. The results resolve some existing interpretational ambiguities and expose some peculiarities of electric field effect on vibronic eigenstates of Frenkel parentage, highlighting the role of charge-transfer interactions.

Low-carbohydrate, high-fat (LC-HF) diets are popular for inducing weight loss in adults and are also used as part of a treatment for children with epilepsy. However, potential risks and side effects remain controversial. We investigated effects of LC-HF diets on growth, bone mineral density (BMD), and turnover in growing rats fed for 4 weeks either normal chow (CH, 9% fat, 33% protein, and 58% carbohydrates), LC-HF-1 (66% fat, 33% protein, and 1% carbohydrates), or LC-HF-2 (94.5% fat, 4.2% protein, and 1.3% carbohydrates). Rats fed LC-HF diets accumulated significantly more visceral and bone marrow fat and showed increased leptin but decreased insulin-like growth-factor 1 (IGF-1). Both LC-HF diets significantly decreased body length (nose to rump), but lengths of humerus, tibia, and femur were significantly reduced with LC-HF-2 only. Peripheral quantitative computed tomography (pQCT) and micro-CT (microCT) independently revealed significant reductions in BMD of tibiae in both LC-HF groups, and tibial maximum load was impaired. Bone-formation marker N-terminal propeptide of type I procollagen was reduced in sera of LC-HF groups, whereas bone resorption marker CrossLaps remained unchanged. Real-time PCR analysis revealed significant reductions by 70% to 80% of transcription factors influencing osteoblastogenesis (Runx2, osterix, and C/EBPbeta) in bone marrow of rats fed LC-HF diets. In conclusion, both LC-HF diets impaired longitudinal growth, BMD, and mechanical properties, possibly mediated by reductions in circulating IGF-1. Serum bone-formation markers as well as expression of transcription factors influencing osteoblastogenesis were reduced. This might indicate a lower rate of mesenchymal stem cells differentiating into osteoblasts, thus explaining reduced bone formation with LC-HF diets., (Copyright 2010 American Society for Bone and Mineral Research.)

Background: In many patients, the benefit of interventional bronchoscopy cannot be appropriately objectified., Objectives: We investigated a new technique, vibration response imaging (VRI), for breathing sound mapping to determine whether it could provide additional, valuable objective qualitative and quantitative information in central airway obstruction (CAO) and patient outcome following interventional bronchoscopy., Methods: VRI images from 83 patients with suspected central airway stenosis and 25 healthy volunteers were evaluated by two raters blinded to the subjects' status. Qualitative and quantitative dynamic and static features were documented for the final assessment of images as normal or abnormal and changes after the intervention. As a secondary goal, stenosis location was also evaluated and compared to bronchoscopic findings. Treatment outcome analysis (improved vs. not improved) was performed by comparing baseline and follow-up images in 64 evaluations of interventional bronchoscopy. VRI measurements of treatment outcome were compared to standard tests, i.e. dyspnea score, pulmonary function testing (PFT, i.e. FEV(1), FVC and FEV(1)/FVC), chest X-ray/computed tomography and bronchoscopy, the latter being considered the gold standard)., Results: There was 95% (115/121) agreement between raters and clinical assessment in distinguishing between normal and abnormal images. The sensitivity and specificity of VRI were 97 and 88%, respectively. The accuracy of VRI in locating the pathology compared to bronchoscopy was 85% (17/20) for tracheal and 88% (51/58) for bronchial obstruction; overall accuracy was 83%. Correct detection of the affected side in bronchial obstructions was 88%. The overall accuracy of VRI in defining the outcome of interventional bronchoscopy was 84%., Conclusions: Obstruction location and procedure outcome were reliably identified according to specific patterns of lung images. VRI proved at least as good as standard tests in locating CAO and has the potential for becoming a valuable complementary tool in evaluating treatment outcome in patients with CAO. If our results are confirmed by further studies, VRI may replace PFT or imaging procedures in cases in which such tests cannot be performed or are not readily available at the time of the intervention., (2008 S. Karger AG, Basel.)

Background: Dosage of T(4) in central hypothyroidism is primarily guided by the free serum T(4) level (fT4). However, the optimum fT4 range is ill defined, and subtle hypothyroidism might be missed using this approach., Objectives: Our aim was to investigate the effects of a body weight (bw)-adapted T(4) treatment, alone or in combination with T(3), on metabolism, well-being, and cognitive function in comparison to a regimen leading to normal fT4., Design: This was a placebo-controlled trial (double-blind, crossover)., Patients: A total of 29 patients (age 52 +/- 2 yr; females/males, 8/21) with hypopituitarism, including TSH deficiency, participated in the study., Interventions: Three regimens were compared (5 wk each): "EMPIRICAL-T4," empirical T(4) dosage (1 +/- 0.05 microg/kg bw) leading to normal fT4; BW-ADAPTED-T4 (1.6 microg/kg bw T(4)); and "BW-ADAPTED-T3T4," bw-adapted combination of T(3) and T(4) (ratio of 1:10)., Results: BW-ADAPTED-T4 administration increased mean fT4 concentrations to the upper limit of the normal range (peak levels). Compared with EMPIRICAL-T4, BW-ADAPTED-T4 treatment resulted in a lower body mass index (BMI) (29.0 +/- 0.7 vs. 29.5 +/- 0.7 kg/m(2); P < 0.03), lower total cholesterol (198 +/- 9 vs. 226 +/- 7 mg/dl; P < 0.01), and lower low-density lipoprotein (LDL) cholesterol (116 +/- 5 vs. 135 +/- 7 mg/dl; P < 0.01). BW-ADAPTED-T3T4 treatment was associated with additional beneficial effects on ankle reflex time and working memory but resulted in supraphysiological free serum T(3) (fT(3)) levels., Limitations: Long-term side effects may have been missed., Conclusions: Using a dose of 1.6 microg/kg bw improved markers commonly associated with central hypothyroidism. This suggests that T(4) dosage based on bw and aiming at fT4 in the upper reference range is superior to titration of T(4) aiming at middle normal fT4 concentrations in those patients.

Despite the fact that the last decade has seen major advances in our knowledge of obesity, the average unsatisfactory successes of lifestyle changes and pharmacological treatment strategies clearly show how very far obesity research and treatment still has to go. What is most regrettable, however, is the fact that, in contrast to the WHO, the German Social Security Code V does not recognize obesity as a disease. This means ignoring the approaching flood of costs associated with obesity, which will put a great strain our health system.

Mouse models of adrenal tumorigenesis have the potential to give insights in the dysregulation of adrenal growth and differentiation. The inbred mouse strain CE/J has been reported to develop adrenal tumors upon gonadectomy (GDX) similar to mice with targeted deletions of the inhibin alpha subunit (Inh-/-). We performed a detailed morphological and molecular characterization of adrenal glands from CE/J mice 8-50 weeks of age to define the cellular origin of these tumors as well as the spatial and temporal expression of marker genes associated with tumor growth. In contrast to the induction of x-zone growth upon GDX in Inh-/- mice, GDX in CE/J mice induced the appearance of sub-capsular nests of densely packed cells that progress into adrenal tumors. Staining for proliferative cell nuclear antigen confirms a substantial increased in cellular proliferation within this sub-capsular compartment and lack of apoptosis upon GDX. Induction of adrenal tumor growth was accompanied by transcriptional changes that otherwise define gonadal endocrine cells. These regulated genes included transcription factors such as GATA-4, WT-1, FOG-1, and steroidogenic factor-1 (SF-1), peptide hormones such as Mullerian-inhibiting substance (MIS), hormone receptors including luteinizing hormone and MIS receptor, and steroidogenic enzymes such as P450c17 and P450 aromatase. The functional significance of steroid enzyme expression was demonstrated by a gradual increase of adrenal androgens after GDX. Taken together these data suggest that adrenal tumors in gonad-ectomized CE/J mice are direct derivatives from cells of the proposed sub-capsular stem cell zone. The distinct expression pattern of this cell population is consistent with a defect in the differentiation of these cells into a cell population with functional properties that otherwise define a gonadal endocrine phenotype.

The safest place to store lipids is the white adipose tissue, but its storage capacity may become saturated resulting in excess of fat "overspilled" to non-adipose tissues. This overspill of fat occurs in apparently opposite pathological states such as lipodistrophy or obesity. When the excess of energy is redirected towards peripheral organs, their initial response is to facilitate the storage of the surplus in the form of triacylglycerol, but the limited triacylglycerol buffer capacity becomes saturated soon. Under these conditions excess of lipids enter alternative non-oxidative pathways that result in production of toxic reactive lipid species that induce organ-specific toxic responses leading to apoptosis. Reactive lipids can accumulate in non-adipose tissues of metabolically relevant organs such as pancreatic beta-cells, liver, heart and skeletal muscle leading to lipotoxicity, a process that contributes substantially to the pathophysiology of insulin resistance, type 2 diabetes, steatotic liver disease and heart failure. The effects of this lipotoxic insult can be minimised by several strategies: (a) decreased incorporation of energy, (b) a less orthodox approach such as increased adipose tissue expandability and/or (c) increased oxidation of fat in peripheral organs. Aging should be considered as physiological degenerative process potentially accelerated by concomitant lipotoxic insults. Conversely, the process of aging can sensitise cells to effects of lipid toxicity.

Obesity is one of the major health problems in developed countries. More than 35% of adults in Germany are considered to be overweight (BMI 25-29.9 kg/m(2)) and approximately 15-20% to be obese (BMI >30 kg/m(2)). Overweight and obesity result from chronic disruption of energy balance. Recent progress in understanding of appetite control and energy expenditure has elucidated a complex integrated system of energy homoeostasis. Although changes in nutritional habits and reduction of physical activity are the main characteristics leading to the strong increase in obesity, it is now recognized that obesity is not only caused by a lack of will power, but can be a consequence of metabolic defects. As obesity results from a genetic make-up favoring weight gain in an "obesigenic" environment the elucidation of the underlying molecular mechanisms might be translated in novel therapeutic options in the future.

Objective: Adrenocorticotropic hormone (ACTH) is the primary secretagogue stimulating secretion of adrenal androgens (AA). Yet, genetic and environmental factors are assumed to play a determining role in the regulation of their biosynthesis and thus might explain the high variability of AA levels. Here we investigate the influence of an ACTH receptor promoter polymorphism affecting ACTH receptor gene transcription on ACTH-dependent dehydroepiandrosterone (DHEA) secretion., Design: We recently reported a polymorphism within the transcription initiation site of the ACTH receptor gene promoter that alters the consensus sequence from CTC to CCC at -2 bp. This results in lower promoter activity in vitro and is associated with impaired cortisol response to ACTH stimulation in vivo. We now studied 14 normal, lean volunteers aged 20-35 years (eight CTC/CTC and six CCC/CCC carriers) in a 6-h ACTH stimulation test., Methods: After overnight dexamethasone suppression, ACTH1-24 was administered continuously in each subject with hourly increasing doses (120-3840 ng/m2 body surface area/h) within a 6-h period. On a separate day, baseline DHEA samples were collected., Results: In the 6-h ACTH stimulation test, CTC/CTC carriers showed a significantly higher DHEA response than CCC/CCC carriers (area under the curve: 19 367 +/- 2919 vs 11 098 +/- 1241 nmol/l per min; P < 0.04, Mann-Whitney U-test). In contrast, baseline DHEA concentrations did not differ between groups., Conclusion: These data demonstrate that genetic variations within the ACTH receptor promoter result in decreased DHEA secretion. Thus, we might have identified one of the genetic factors responsible for variation in ACTH-dependent DHEA secretion.

Pyruvate carboxylase (PC) plays a crucial role in various metabolic pathways, including gluconeogenesis, lipogenesis, and glucose-induced insulin secretion. Here we showed for the first time that the PC gene is transcriptionally regulated by peroxisome proliferator-activated receptor-gamma (PPARgamma) in vitro and in vivo in white and brown adipose tissue. PC mRNA and protein are markedly increased during differentiation of 3T3-L1 cells and HIB-1B, in parallel with the expression of the adipogenic transcription factors, CCAAT-enhancer binding protein alpha, PPARgamma1, and PPARgamma2. Tumor necrosis factor-alpha, a cytokine that blocks differentiation of 3T3-L1 cells, suppressed PC expression. Co-transfection studies in 3T3-L1 preadipocytes or HEK293T cells with a 2.3-kb promoter fragment of mouse PC gene linked to a luciferase reporter construct and with plasmids overexpressing retinoid X receptor alpha/PPARgamma1 or retinoid X receptor alpha/PPARgamma2 showed a 6-8-fold increase above the basal promoter activity. Furthermore, treatment of these transfected cells with the PPARgamma agonist doubled the promoter activity. Mutation of the putative PPAR-response element-(-386/-374) of this 2.3-kb PC promoter fragment abolished the PPARgamma response. Gel shift and chromatin immunoprecipitation assays demonstrated that endogenous PPARgamma binds to this functional PPAR-response element of the PC promoter. Mice with targeted disruption of the PPARgamma2 gene displayed approximately 50-60% reduction of PC mRNA and protein in white adipose tissue. Similarly, in brown adipose tissue of PPARgamma2-deficient mice subjected to cold exposure, PC mRNA was 40% lower than that of wild type mice. Impaired in vitro differentiation of white adipocytes of PPARgamma2 knock-out mice was also associated with a marked reduction of PC mRNA. Our findings identified PC as a PPARgamma-regulated gene and suggested a role for PPARgamma regulating intermediary metabolism.

The ACTH receptor has a pivotal role in the regulation of adrenal cortisol secretion. Here, we describe a polymorphism within the transcription initiation site of the ACTH receptor promoter altering the consensus sequence from CTC to CCC. The prevalence of the polymorphism in 1266 unrelated healthy men was 80.2% for CTC/CTC, 19.0% for CTC/CCC, and 0.8% for CCC/CCC, respectively. In vitro studies using luciferase assays demonstrated a lower basal (CCC, 73 +/- 4%; CTC, 100 +/- 5%; P = 0.02) and forskolin-stimulated (CCC, 143 +/- 13%; CTC, 194 +/- 15%; P = 0.0008) promoter activity in the CCC construct compared with CTC. The clinical significance of the in vitro findings was investigated by a 6-h ACTH stimulation test with increasing ACTH(1-24) doses in normal subjects, demonstrating a blunted cortisol response in CCC/CCC subjects compared with CTC/CTC individuals (area under the curve, 12176 +/- 966; 16334 +/- 1051 nmol/liter.min; P < 0.03). Accordingly, after CRH stimulation, subjects with CCC/CCC showed a higher ACTH/cortisol ratio (P < 0.05) suggesting a decreased adrenal responsiveness to endogenous ACTH. In conclusion, we describe an ACTH receptor promoter polymorphism that results in a lower promoter activity in vitro and is associated with a lower cortisol secretion to prolonged ACTH stimulation in vivo. This polymorphism might influence cortisol homeostasis under stress conditions.

A novel delivery system has been developed for testosterone replacement. This formulation, COL-1621 (Striant), a testosterone-containing buccal mucoadhesive system, has been shown in preliminary studies to replace testosterone at physiological levels when used twice daily. Therefore, the current study compared the steady-state pharmacokinetics and tolerability of the buccal system with a testosterone-containing skin patch (Andropatch or Androderm) in an international multicenter study of a group of hypogonadal men. Sixty-six patients were randomized into two groups; one applied the buccal system twice daily, whereas the other applied the transdermal patch daily, in each case for 7 d. Serum total testosterone and dihydrotestosterone concentrations were measured at d 1, 3 or 4, and 6, and serially over the last 24 h of the study. Pharmacokinetic parameters for each formulation were calculated, and the two groups were compared. The tolerability of both formulations was also evaluated. Thirty-three patients were treated with the buccal preparation, and 34 were treated with the transdermal patch. The average serum testosterone concentration over 24 h showed a mean of 18.74 nmol/liter (SD =; 5.90) in the buccal system group and 12.15 nmol/liter (SD =; 5.55) in the transdermal patch group (P < 0.01). Of the patients treated with the buccal system, 97% had average steady-state testosterone concentrations within the physiological range (10.41-36.44 nmol/liter), whereas only 56% of the transdermal patch patients achieved physiological total testosterone concentrations (P < 0.001 between groups). Testosterone concentrations were within the physiological range in the buccal system group for a significantly greater portion of the 24-h treatment period than in the transdermal patch group (mean, 84.9% vs. 54.9%; P < 0.001). Testosterone/dihydrotestosterone ratios were physiological and similar in both groups. Few patients experienced major adverse effects from either treatment. No significant local tolerability problems were noted with the buccal system, other than a single patient withdrawal. We conclude that this buccal system is superior to the transdermal patch in achieving testosterone concentrations within the normal range. It may, therefore, be a valuable addition to the range of choices for testosterone replacement therapy.