Steroid hormones interrelationships in the metabolic syndrome: an introduction to the ponderostat hypothesis

Sexual dimorphism in the metabolic syndrome. The clairvoyant early implication of sex hormones in the characterization of the metabolic syndrome (MS) was detected early, and in accordance with the well-known sex-related main patterns of fat deposition in obesity: gynoid and android. The differences point to a direct implication of androgens and estrogens in the development, properties and maintenance of obesity and, by extension, to the cumulus of diseases grouped in the MS. For a long time, the key issue of the MS, i.e. the metabolic event explaining (and justifying) most of the derangements of the MS, has been considered to be insulin resistance (...)

Metabolic connectivity as index of verbal working memory.

Positron emission tomography (PET) data are commonly analyzed in terms of regional intensity, while covariant information is not taken into account. Here, we searched for network correlates of healthy cognitive function in resting state PET data. PET with [(18)F]-fluorodeoxyglucose and a test of verbal working memory (WM) were administered to 35 young healthy adults. Metabolic connectivity was modeled at a group level using sparse inverse covariance estimation. Among 13 WM-relevant Brodmann areas (BAs), 6 appeared to be robustly connected. Connectivity within this network was significantly stronger in subjects with above-median WM performance. In respect to regional intensity, i.e., metabolism, no difference between groups was found. The results encourage examination of covariant patterns in FDG-PET data from non-neurodegenerative populations.

Inflammatory and metabolic responses to high-fat meals with and without dairy products in men.

Postprandial inflammation is an important factor for human health since chronic low-grade inflammation is associated with chronic diseases. Dairy products have a weak but significant anti-inflammatory effect on postprandial inflammation. The objective of the present study was to compare the effect of a high-fat dairy meal (HFD meal), a high-fat non-dairy meal supplemented with milk (HFM meal) and a high-fat non-dairy control meal (HFC meal) on postprandial inflammatory and metabolic responses in healthy men. A cross-over study was conducted in nineteen male subjects. Blood samples were collected before and 1, 2, 4 and 6 h after consumption of the test meals. Plasma concentrations of insulin, glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol, TAG and C-reactive protein (CRP) were measured at each time point. IL-6, TNF-α and endotoxin concentrations were assessed at baseline and endpoint (6 h). Time-dependent curves of these metabolic parameters were plotted, and the net incremental AUC were found to be significantly higher for TAG and lower for CRP after consumption of the HFM meal compared with the HFD meal; however, the HFM and HFD meals were not different from the HFC meal. Alterations in IL-6, TNF-α and endotoxin concentrations were not significantly different between the test meals. The results suggest that full-fat milk and dairy products (cheese and butter) have no significant impact on the inflammatory response to a high-fat meal.

Short-term HIIT and Fatmax training increase aerobic and metabolic fitness in men with class II and III obesity.

OBJECTIVE: To compare the effects of two different 2-week-long training modalities [continuous at the intensity eliciting the maximal fat oxidation (Fatmax ) versus high-intensity interval training (HIIT)] in men with class II and III obesity. METHODS: Nineteen men with obesity (BMI ≥ 35 kg(.) m(-2) ) were assigned to Fatmax group (GFatmax ) or to HIIT group (GHIIT ). Both groups performed eight cycling sessions matched for mechanical work. Aerobic fitness and fat oxidation rates (FORs) during exercise were assessed prior and following the training. Blood samples were drawn to determine hormones and plasma metabolites levels. Insulin resistance was assessed by the homeostasis model assessment of insulin resistance (HOMA2-IR). RESULTS: Aerobic fitness and FORs during exercise were significantly increased in both groups after training (P ≤ 0.001). HOMA2-IR was significantly reduced only for GFatmax (P ≤ 0.001). Resting non-esterified fatty acids (NEFA) and insulin decreased significantly only in GFatmax (P ≤ 0.002). CONCLUSIONS: Two weeks of HIIT and Fatmax training are effective for the improvement of aerobic fitness and FORs during exercise in these classes of obesity. The decreased levels of resting NEFA only in GFatmax may be involved in the decreased insulin resistance only in this group.

Long-Lasting Metabolic Imbalance Related to Obesity Alters Olfactory Tissue Homeostasis and Impairs Olfactory-Driven Behaviors.

Obesity is associated with chronic food intake disorders and binge eating. Food intake relies on the interaction between homeostatic regulation and hedonic signals among which, olfaction is a major sensory determinant. However, its potential modulation at the peripheral level by a chronic energy imbalance associated to obese status remains a matter of debate. We further investigated the olfactory function in a rodent model relevant to the situation encountered in obese humans, where genetic susceptibility is juxtaposed on chronic eating disorders. Using several olfactory-driven tests, we compared the behaviors of obesity-prone Sprague-Dawley rats (OP) fed with a high-fat/high-sugar diet with those of obese-resistant ones fed with normal chow. In OP rats, we reported 1) decreased odor threshold, but 2) poor olfactory performances, associated with learning/memory deficits, 3) decreased influence of fasting, and 4) impaired insulin control on food seeking behavior. Associated with these behavioral modifications, we found a modulation of metabolism-related factors implicated in 1) electrical olfactory signal regulation (insulin receptor), 2) cellular dynamics (glucorticoids receptors, pro- and antiapoptotic factors), and 3) homeostasis of the olfactory mucosa and bulb (monocarboxylate and glucose transporters). Such impairments might participate to the perturbed daily food intake pattern that we observed in obese animals.

Gene Expression Profiling of Desmoid Tumors by cDNA Microarrays and Correlation with Progression-Free Survival.

PURPOSE: Because desmoid tumors exhibit an unpredictable clinical course, translational research is crucial to identify the predictive factors of progression in addition to the clinical parameters. The main issue is to detect patients who are at a higher risk of progression. The aim of this work was to identify molecular markers that can predict progression-free survival (PFS). EXPERIMENTAL DESIGN: Gene-expression screening was conducted on 115 available independent untreated primary desmoid tumors using cDNA microarray. We established a prognostic gene-expression signature composed of 36 genes. To test robustness, we randomly generated 1,000 36-gene signatures and compared their outcome association to our define 36-genes molecular signature and we calculated positive predictive value (PPV) and negative predictive value (NPV). RESULTS: Multivariate analysis showed that our molecular signature had a significant impact on PFS while no clinical factor had any prognostic value. Among the 1,000 random signatures generated, 56.7% were significant and none was more significant than our 36-gene molecular signature. PPV and NPV were high (75.58% and 81.82%, respectively). Finally, the top two genes downregulated in no-recurrence were FECH and STOML2 and the top gene upregulated in no-recurrence was TRIP6. CONCLUSIONS: By analyzing expression profiles, we have identified a gene-expression signature that is able to predict PFS. This tool may be useful for prospective clinical studies. Clin Cancer Res; 21(18); 4194-200. ©2015 AACR.

Responders to Wide-Pulse, High-Frequency Neuromuscular Electrical Stimulation Show Reduced Metabolic Demand: A 31P-MRS Study in Humans.

Conventional (CONV) neuromuscular electrical stimulation (NMES) (i.e., short pulse duration, low frequencies) induces a higher energetic response as compared to voluntary contractions (VOL). In contrast, wide-pulse, high-frequency (WPHF) NMES might elicit-at least in some subjects (i.e., responders)-a different motor unit recruitment compared to CONV that resembles the physiological muscle activation pattern of VOL. We therefore hypothesized that for these responder subjects, the metabolic demand of WPHF would be lower than CONV and comparable to VOL. 18 healthy subjects performed isometric plantar flexions at 10% of their maximal voluntary contraction force for CONV (25 Hz, 0.05 ms), WPHF (100 Hz, 1 ms) and VOL protocols. For each protocol, force time integral (FTI) was quantified and subjects were classified as responders and non-responders to WPHF based on k-means clustering analysis. Furthermore, a fatigue index based on FTI loss at the end of each protocol compared with the beginning of the protocol was calculated. Phosphocreatine depletion (ΔPCr) was assessed using 31P magnetic resonance spectroscopy. Responders developed four times higher FTI's during WPHF (99 ± 37 ×103 N.s) than non-responders (26 ± 12 ×103 N.s). For both responders and non-responders, CONV was metabolically more demanding than VOL when ΔPCr was expressed relative to the FTI. Only for the responder group, the ∆PCr/FTI ratio of WPHF (0.74 ± 0.19 M/N.s) was significantly lower compared to CONV (1.48 ± 0.46 M/N.s) but similar to VOL (0.65 ± 0.21 M/N.s). Moreover, the fatigue index was not different between WPHF (-16%) and CONV (-25%) for the responders. WPHF could therefore be considered as the less demanding NMES modality-at least in this subgroup of subjects-by possibly exhibiting a muscle activation pattern similar to VOL contractions.

Iron metabolism and incidence of metabolic syndrome.

BACKGROUND AND AIMS: Whether iron metabolism affects metabolic syndrome (METS) is debated. We assessed the association between several markers of iron metabolism and incidence of METS. METHODS AND RESULTS: Data from 3271 participants (1870 women, 51.3 ± 10.4 years), free of METS at baseline and followed for 5.5 years. The association of serum iron, ferritin and transferrin with incident METS was assessed separately by gender. Incidence of METS was 22.6% in men and 16.5% in women (p < 0.001). After multivariate adjustment, a positive association was found between transferrin and incident METS in men: odds ratio (OR) and 95% confidence interval for the fourth relative to the first quartile 1.55 (1.04-2.31), p for trend = 0.03, while no association was found for iron OR = 0.81 (0.53-1.24), p for trend = 0.33 and ferritin OR = 1.30 (0.88-1.92), p for trend = 0.018. In women, a negative association was found between iron and incident METS: OR for the fourth relative to the first quartile 0.51 (0.33-0.80), p for trend<0.03; the association between transferrin and incident METS was borderline significant: OR = 1.45 (0.97-2.17), p for trend = 0.07 and no association was found for ferritin: OR = 1.11 (0.76-1.63), p for trend = 0.58. CONCLUSION: Transferrin, not ferritin, is independently associated with an increased risk of incident METS; the protective effect of iron in women should be further explored.

Further molecular profiling of tumors harboring therapeutic targets within non-small cell lung cancer

Background: Treatment of NSCLC has been revolutionized in recent years with the introduction of several targeted therapies for selected genetically altered subtypes of NSCLC. A better understanding of molecular characteristics of NSCLC, which features common drug targets, may identify new therapeutic options. Methods: Over 6,700 non-small cell lung cancer cases referred to Caris Life Sciences between 2009 and 2014. Diagnoses and history were collected from referring physicians. Specific testing was performed per physician request and included a combination of sequencing (Sanger, NGS or pyrosequencing), protein expression (IHC), gene amplification/rearrangement (CISH or FISH), and/or RNA fragment analysis. Results: Tumors profiles from patients with hormone receptor positive disease (HER2, ER, PR, or AR positive by IHC) (n=629), HER2 mutations (n=8) ALK rearrangements (n=55), ROS1 rearrangement (n=17), cMET amplification or mutation (n=126), and cKIT mutation (n=11) were included in this analysis and compared to the whole cohort. Tumors with ALK rearrangement overexpressed AR in 18% of cases, and 7% presented with concomitant KRAS mutation. Lower rates of PTEN loss, as assessed by IHC, were observed in ALK positive (20%), ROS1 positive (9%) and cKIT mutated tumors (25%) compared to the overall NSCLC population (58%). cMET was overexpressed in 66% of ROS1 translocated and 57% of HER2 mutated tumors. cKIT mutations were found co-existing with APC (20%) and EGFR (20%) mutations. Pathway analysis revealed that hormone receptor positive disease carried more mutations in the ERK pathway (32%) compared to 9% in the mTOR pathway. 25% of patients with HER2 mutations harbored a co-existing mutation in the mTOR pathway. Conclusions: Pathway profiling reveals that NSCLC tumors present more often than reported with several concomitant alterations affecting the ERK or AKT pathway. Additionally, they are also characterized by the expression of potential biological modifiers of the cell cycle like hormonal receptors, representing a rationale for dual inhibition strategies in selected patients. Further refining of the understanding of NSCLC biomarker profile will optimize research for new treatment strategies.

Molecular profiling of non-small cell lung cancer by histologic subtype

Background: A substantial proportion of NSCLC has been shown to harbour specific molecular alterations affecting tumour proliferation and resulting in sensitivity to inhibition of the corresponding activated oncogenic pathway by targeted therapies. Comprehensive tumor profiling can diagnose such alterations and may identify new alterations opening additional treatment options for all distinct NSCLC subtypes. Methods: Over 6,700 non-small cell lung cancer cases referred to Caris Life Sciences between 2009 and 2014 were evaluated; clinical diagnoses and detailed tumor pathology were collected from referring physicians. Specific profiling was performed per physician request and included a combination of sequencing (Sanger, NGS or pyrosequencing), protein expression (IHC), gene amplification/rearrangement (CISH or FISH), and/or RNA fragment analysis within potential cancer-related genes and pathways. Results: Patients were grouped into cohorts according to histological subtype - adenocarcinoma (AD) (n=4,286), squamous cell carcinoma (SCC) (n=1,280), large cell carcinoma (LCC) (n=153) and bronchioalveolar carcinoma (BAC) (n=94). Protein overexpression of cMET (>2+ in >50% cells) was higher in AD (35.9%) compared to other subgroups (12-20%) while RRM1 and TOP2A levels were lower in AD. ALK or ROS1 were rearranged in 5.3% of patients with AD compared to 3.7% of patients with LCC and 1.2% of patients with SCC. EGFR mutations were found at low prevalence in both the LCC (0%) and SCC cohorts (2.8%) compared to 21% in AD. Similar lower rates of BRAF mutations were observed in the LCC and SCC cohorts compared to AD (0%, 1.1% and 5.1%). Pathway analysis showed activating mutations in the ERK pathway in 40% of patients with AD. Only 10-12% of patients with LCC or SCC had activating mutations in the ERK pathway. Conclusions: Despite the limitations of this retrospective series, we report comprehensive profiling of the largest cohort of NSCLC. Tumor profiling reveals that ADs may be more addicted to the ERK pathway than other histological subtypes. Drugs which target cMET may also have most utility in AD. Full analysis by histological subtype and additional correlative data on protein expression, gene copy number and mutations will be presented.

Imaging the time-integrated cerebral metabolic activity with subcellular resolution through nanometer-scale detection of biosynthetic products deriving from (13)C-glucose.

Glucose is the primary source of energy for the brain but also an important source of building blocks for proteins, lipids, and nucleic acids. Little is known about the use of glucose for biosynthesis in tissues at the cellular level. We demonstrate that local cerebral metabolic activity can be mapped in mouse brain tissue by quantitatively imaging the biosynthetic products deriving from [U-(13)C]glucose metabolism using a combination of in situ electron microscopy and secondary ion mass-spectroscopy (NanoSIMS). Images of the (13)C-label incorporated into cerebral ultrastructure with ca. 100nm resolution allowed us to determine the timescale on which the metabolic products of glucose are incorporated into different cells, their sub-compartments and organelles. These were mapped in astrocytes and neurons in the different layers of the motor cortex. We see evidence for high metabolic activity in neurons via the nucleus (13)C enrichment. We observe that in all the major cell compartments, such as e.g. nucleus and Golgi apparatus, neurons incorporate substantially higher concentrations of (13)C-label than astrocytes.

CRTC2 polymorphism as a risk factor for the incidence of metabolic syndrome in patients with solid organ transplantation.

NlmCategory="UNASSIGNED">Metabolic syndrome after transplantation is a major concern following solid organ transplantation (SOT). The CREB-regulated transcription co-activator 2 (CRTC2) regulates glucose metabolism. The effect of CRTC2 polymorphisms on new-onset diabetes after transplantation (NODAT) was investigated in a discovery sample of SOT recipients (n1=197). Positive results were tested for replication in two samples from the Swiss Transplant Cohort Study (STCS, n2=1294 and n3=759). Obesity and other metabolic traits were also tested. Associations with metabolic traits in population-based samples (n4=46'186, n5=123'865, n6>100,000) were finally analyzed. In the discovery sample, CRTC2 rs8450-AA genotype was associated with NODAT, fasting blood glucose and body mass index (Pcorrected<0.05). CRTC2 rs8450-AA genotype was associated with NODAT in the second STCS replication sample (odd ratio (OR)=2.01, P=0.04). In the combined STCS replication samples, the effect of rs8450-AA genotype on NODAT was observed in patients having received SOT from a deceased donor and treated with tacrolimus (n=395, OR=2.08, P=0.02) and in non-kidney transplant recipients (OR=2.09, P=0.02). Moreover, rs8450-AA genotype was associated with overweight or obesity (n=1215, OR=1.56, P=0.02), new-onset hyperlipidemia (n=1007, OR=1.76, P=0.007), and lower high-density lipoprotein-cholesterol (n=1214, β=-0.08, P=0.001). In the population-based samples, a proxy of rs8450G>A was significantly associated with several metabolic abnormalities. CRTC2 rs8450G>A appears to have an important role in the high prevalence of metabolic traits observed in patients with SOT. A weak association with metabolic traits was also observed in the population-based samples.The Pharmacogenomics Journal advance online publication, 8 December 2015; doi:10.1038/tpj.2015.82.

HDLs, diabetes, and metabolic syndrome.

The prevalence of type 2 diabetes mellitus and of the metabolic syndrome is rising worldwide and reaching epidemic proportions. These pathologies are associated with significant morbidity and mortality, in particular with an excess of cardiovascular deaths. Type 2 diabetes mellitus and the cluster of pathologies including insulin resistance, central obesity, high blood pressure, and hypertriglyceridemia that constitute the metabolic syndrome are associated with low levels of HDL cholesterol and the presence of dysfunctional HDLs. We here review the epidemiological evidence and the potential underlying mechanisms of this association. We first discuss the well-established association of type 2 diabetes mellitus and insulin resistance with alterations of lipid metabolism and how these alterations may lead to low levels of HDL cholesterol and the occurrence of dysfunctional HDLs. We then present and discuss the evidence showing that HDL modulates insulin sensitivity, insulin-independent glucose uptake, insulin secretion, and beta cell survival. A dysfunction in these actions could play a direct role in the pathogenesis of type 2 diabetes mellitus.

Markers of iron metabolism and metabolic syndrome in Swiss adults

Plusieurs études populationnelles ont montré l'existence d'une association entre des taux sanguins élevés de transferrine et le syndrome métabolique (SM). Bien que cette association soit bien établie, restent encore à être décrites les associations entre le SM et les autres marqueurs sanguins du métabolisme du fer, tels que le fer, la transferrine (Tsf), la capacité totale de fixation de la transferrine (CTF) ou la saturation de la transferrine (SaTsf) sanguins. Le but de notre étude a été d'identifier les associations entre les différents marqueurs du métabolisme du fer (fer, ferritine, Tsf, CTF et SaTsf) et le SM. Les données de l'étude CoLaus, récoltées entre 2003 et 2006, ont été utilisées. Le SM était défini selon les critères du National Cholesterol Education Program Adult Panel III. L'analyse statistique a été faite en stratifiant selon le genre ainsi que le status ménopausal chez les femmes. Des 6733 participants, 1235 (18%) ont été exclus de fait d'absence de données concernant les variables qui nous intéressaient, ou chez qui nous avons soupçonné une possible hémochromatose non diagnostiquée (SaTsf> 50%). Des 5498 participants restant (âge moyen ± écart-type: 53 ± 11 ans), 2596 étaient des hommes, 1285 des femmes pré- et 1617 des femmes postménopausées. La prévalence du SM était de 29,4% chez les hommes, 8,3% et 25,5% chez les femmes pré- et postménopausées, respectivement. Dans les trois groupes, la prévalence du SM était la plus haute dans les quartiles les plus élevés de ferritine, Tsf et CTF, ainsi que dans le quartile le plus bas de SaTsf. Après ajustement sur l'âge, l'indice de masse corporelle, la protéine C réactive, la consommation de tabac et/ou d'alcool, la prise de suppléments en fer et les marqueurs hépatiques, l'appartenance au quartile le plus élevé de ferritine, Tsf ou CTF était associée à un risque plus important de SM chez les hommes et les femmes postménopausées : Odds ratio (OR) et [intervalle de confiance à 95%] pour la ferritine 1.44 [1.07-1.94] et 1.47 [0.99-2.17]; pour la Tsf et la CTF, OR=1.43 [1.06-1.91] et 2.13 [1.44-3.15] pour les hommes et les femmes postménopausées, respectivement. Au contraire, l'appartenance au quartile le plus élevé de la SaTsf était associé à un risque moins important de SM: OR=0.77 [0.57-1.05] et 0.59 [0.39-0.90] pour les hommes et les femmes postménopausées, respectivement. Il n'y avait aucune association entre les marqueurs sanguins du métabolisme du fer et le SM chez les femmes préménopausées, ni entre le fer sanguin et le SM chez les trois groupes. En conclusion, la majorité des marqueurs sanguins du métabolisme du fer, mais pas le fer lui-même, sont associés de manière indépendante au SM chez les hommes et les femmes postménopausées. -- Context: Excessive iron storage has been associated with metabolic syndrome (MS). Objective: To assess the association between markers of iron metabolism and MS in a healthy population. Design: Cross-sectional study conducted between 2003 and 2006. Setting: Population-based study in Lausanne, Switzerland. Patients: 5,498 participants aged 35-75 years, stratified by sex and menopausal status. Participants with transferrin saturation (TSAT) >50% were excluded. Intervention: None. Main Outcome Measures: serum iron, ferritin, transferrin, total iron binding capacity (TIBC) and TSAT. MS was defined according to ATP-III criteria. Results: Prevalence of MS was 29.4% in men, 8.3% in premenopausal and 25.5% in postmenopausal women. On bivariate analysis, the highest prevalence of MS occurred in the highest quartiles of serum ferritin, transferrin and TIBC, and in the lowest quartile of TSAT. After multivariate adjustment for age, body mass index, C-reactive protein, smoking, alcohol, liver markers and iron supplementation, men and postmenopausal women in the highest quartile of serum ferritin, transferrin and TIBC had a higher risk of presenting with MS: for ferritin, Odds ratio and [95% CI]=1.44 [1.07-1.94] for men and 1.47 [0.99-2.17] for postmenopausal women; for transferrin and TIBC, OR=1.43 [1.06-1.91] and 2.13 [1.44-3.15], Participants in the highest quartile of TSAT had a lower risk of MS: OR=0.77 [0.57-1.05] for men and 0.59 [0.39-0.90] for postmenopausal women. No association was found between iron and MS and between markers of iron metabolism and MS in premenopausal women. Conclusion: Ferritin, transferrin, TIBC are positively and TSAT is negatively associated with MS in men and postmenopausal women.