Effect of weight loss,independent of change in diet composition,on apolipoprotein AI kinetic in men with metabolic syndrome

We investigated the effect of weight loss, independent of change in diet composition, on HDL and apoAI metabolism in men with metabolic syndrome (MetS). Subjects (19 men with MetS [NCEP-ATPIII]) were fed an isoenergetic Mediterranean-style diet for 5 weeks (all foods provided). Participants then underwent a 20-week free-living period during which they were counseled to restrict energy intake, after which they were again fed an isoenergetic Mediterranean-style diet for 5 weeks. At the end of the two controlled diets, participants received a single bolus of [5,5,5-²H₃] _L-leucine, and fasting blood samples were collected over a 96 h period. ApoAI kinetic was assessed using multicompartmental modeling of the tracer enrichment data. Participants achieved a 9.1 ± 2.8% reduction in body weight (P < 0.001). Weight loss resulted in an increase in plasma HDL-cholesterol (HDL-C) concentrations of 6.0% (P = 0.059) and HDL₃-C of 7.9% (P = 0.045), attributable to a reduction in apoAI fractional catabolic rate (−7.8%; P = 0.046) with no change in apoAI production rate (2.2%; P = 0.58). These data indicate that weight loss, independent of variation in diet composition, increases plasma HDL primarily by delaying the catabolism of apoAI.     

Body mass growth in common marmosets: Toward a model of pediatric obesity

While much is known about adult obesity in nonhuman primates, very little is known regarding development of childhood adiposity. As small monkeys that are easy to handle and have a relatively fast life history, common marmoset monkeys (Callithrix jacchus) offer interesting opportunities to examine the question of fat versus lean mass growth in a nonhuman primate. This article provides an overview of our understanding of early life growth in mass in marmoset monkeys, based primarily upon our past 20 years of research, culminating in our recent findings on early life obesity in this species. Common marmosets display variance in early life growth patterns that is related to both pre‐ and postnatal factors and the marmoset uterine environment is exquisitely designed to reflect resources available for the gestation of multiple offspring, making them an interesting model of developmental programming. We have demonstrated that obesity can be generated in very early life in captive marmosets, with excess adiposity evident by one month of age, making this species a potentially valuable model in which to study pediatric obesity and its sequelae. Birth weight is associated with adiposity in animals vulnerable to obesity. Early life exposure to higher fat diets enhances the chances of postweaning obesity development. However, overall higher food consumption is also associated with obesity development at later ages. One unexpected finding in our studies has been the relatively high body fat percentage of neonatal (12–18%) marmosets suggesting that hypotheses regarding the uniqueness of high human neonatal adiposity merit further examination. Am J Phys Anthropol, 2013. © 2012 Wiley Periodicals, Inc.     

The daidzein- and estradiol- induced anorectic action in CCK or leptin receptor deficiency rats

We investigated the effect of daidzein feeding and estradiol treatment on food intake in cholecystokinin-1 receptor (CCK1R) deficiency, leptin receptor (ObRb) deficiency rats and their wild-type rats. These rats underwent an ovariectomy or a sham operation. For the 5 week experiment, each rat was divided in three groups: control, daidzein (150 mg/kg diet), and estradiol (4.2 μg/rat/day) groups. In both CCK1R+ and CCK1R? rats, daidzein feeding and estradiol treatment significantly decreased food intake. Daidzein feeding significantly reduced food intake in ovariectomized ObRb? rats, although not in ObRb+ rats. Estradiol treatment significantly lowered food intake in ovariectomized ObRb+ and ObRb? rats. In the ovariectomized rats, estradiol treatment significantly increases uterine weight, while daidzein feeding did not change it, suggesting that daidzein might have no or weak estrogenic effect in our experiment. These results suggest that CCK1R and ObRb signalings were not essential for the daidzein- and estradiol-induced anorectic action.     

Role of Copper Ions in the Regulation of L-Glutamate Biosynthesis

Cell-free extracts of Brevibacterium thiogenitalis culture grown in the presence of copper catalyzed the oxidation of NADH₂ and succinate through an electron transport chain which contained menaquinones and cytochromes a, b and c. On the other hand, extracts of cells grown in the absence of copper lacked cytochromes a and c, and contained cytochrome d.

These findings, as well as the results obtained in inhibition experiments, suggest that in copper-deficient cells the major part of NADH₂ was oxidized via a bypass in which the electrons were transferred directly from flavoprotein or cytochrome b to molecular oxygen.

Electron transport from these substrates to molecular oxygen resulted in ATP synthesis. The average P/O ratios in extracts of the copper-sufficient cells were 0.33 for generated NADH₂, 0.20 for added NADH₂, and 0.34 for succinate, and those in extracts of the copper-deficient cells were 0.15, 0.13 and 0.21, respectively. In addition, a linear relationship was found between the yield of L-glutamate from acetate and the P/Ο ratios with both NADH₂ and succinate as substrates.

From these results, it is reasonable to consider that the poor yield of L-glutamate from acetate in copper-deficient cells was due to a reduction in energy supply, which was caused by the low efficiency of oxidative phosphorylation.     

A high-throughput screen for inhibitors of the prolyl isomerase,Pin1, identifies a seaweed polyphenol that reduces adipose cell differentiation

The peptidyl prolyl cis/trans isomerase Pin1 enhances the uptake of triglycerides and the differentiation of fibroblasts into adipose cells in response to insulin stimulation. Pin1 downregulation could be a potential approach to prevent and treat obesity-related disorders. In order to identify an inhibitor of Pin1 that exhibited minimal cytotoxicity, we established a high-throughput screen for Pin1 inhibitors and used this method to identify an inhibitor from 1,056 crude fractions of two natural product libraries. The candidate, a phlorotannin called 974-B, was isolated from the seaweed, Ecklonia kurome. 974-B inhibited the differentiation of mouse embryonic fibroblasts and 3T3-L1 cells into adipose cells without inducing cytotoxicity. We discovered the Pin1 inhibitor, 974-B, from the seaweed, E. kurome, and showed that it blocks the differentiation of fibroblasts into adipose cells, suggesting that 974-B could be a lead drug candidate for obesity-related disorders.     

TRPV1 Agonist Monoacylglycerol Increases UCP1 Content in Brown Adipose Tissue and Suppresses Accumulation of Visceral Fat in Mice Fed a High-Fat and High-Sucrose Diet

The administration of such a transient receptor potential vanilloid 1 (TRPV1) agonist as capsaicin, which is a pungent ingredient of red pepper, promotes energy metabolism and suppresses visceral fat accumulation. We have recently identified monoacylglycerols (MGs) having an unsaturated long-chain fatty acid as the novel TRPV1 agonist in foods. We investigated in this present study the effects of dietary MGs on uncoupling protein 1 (UCP1) expression in interscapular brown adipose tissue (IBAT) and on fat accumulation in mice fed with a high-fat, high-sucrose diet. The MG30 diet that substituted 30% of all lipids for MGs (a mixture of 1-oleoylglycerol, 1-linoleoylglycerol and 1-linolenoylglycerol) significantly increased the UCP1 content of IBAT and decreased the weight of epididymal white adipose tissue, and the serum glucose, total cholesterol and free fatty acid levels. The diet containing only 1-oleoylglycerol as MG also increased UCP1 expression in IBAT. MGs that activated TRPV1 also therefore induced the expression of UCP 1 and prevented visceral fat accumulation as well as capsaicin.     

A meta‐analysis of cardio‐metabolic abnormalities in drug naïve,first‐episode and multi‐episode patients with schizophrenia versus general population controls

A meta‐analysis was conducted to explore the risk for cardio‐metabolic abnormalities in drug naïve, first‐episode and multi‐episode patients with schizophrenia and age‐ and gender‐ or cohort‐matched general population controls. Our literature search generated 203 relevant studies, of which 136 were included. The final dataset comprised 185,606 unique patients with schizophrenia, and 28 studies provided data for age‐ and gender‐matched or cohort‐matched general population controls (n=3,898,739). We found that multi‐episode patients with schizophrenia were at increased risk for abdominal obesity (OR=4.43; CI=2.52‐7.82; p<0.001), hypertension (OR=1.36; CI=1.21‐1.53; p<0.001), low high‐density lipoprotein cholesterol (OR=2.35; CI=1.78‐3.10; p<0.001), hypertriglyceridemia (OR=2.73; CI=1.95‐3.83; p<0.001), metabolic syndrome (OR=2.35; CI=1.68‐3.29; p<0.001), and diabetes (OR=1.99; CI=1.55‐2.54; p<0.001), compared to controls. Multi‐episode patients with schizophrenia were also at increased risk, compared to first‐episode (p<0.001) and drug‐naïve (p<0.001) patients, for the above abnormalities, with the exception of hypertension and diabetes. Our data provide further evidence supporting WPA recommendations on screening, follow‐up, health education and lifestyle changes in people with schizophrenia.     

MiR‐802 causes nephropathy by suppressing NF‐κB‐repressing factor in obese mice and human

Obesity is associated with significant microvascular complications including renal injuries and may induce end‐stage renal disease. Emerging studies have demonstrated microRNAs (miRNAs) are potential mediators in the pathophysiological process of nephropathy. The present study aimed to investigate the role of miR‐802 in obesity‐related nephropathy and potential molecular mechanisms. Through utilizing obese mouse model and human subjects, we explored the therapeutic benefits and clinical application of miR‐802 in protecting against nephropathy. Renal miR‐802 level was positively correlated with functional parameters, including blood urea nitrogen and creatinine in obese mice. Specific silencing of renal miR‐802 improved high fat diet (HFD)‐induced renal dysfunction, structural disorders and fibrosis. The up‐regulated inflammatory response and infiltrated macrophages were also significantly decreased in miR‐802 inhibitor‐treated obese mice. Mechanistically, miR‐802 directly bond to 3?‐UTR of NF‐κB‐repressing factor (NRF) and suppressed its expression. In clinical study, the circulating miR‐802 level was significantly increased in obese subjects, and positively correlated with plasma creatinine level but negatively correlated with creatinine clearance. Taken together, our findings provided evidence that miR‐802/NRF signalling was an important pathway in mediating obesity‐related nephropathy. It is a possible useful clinical approach of treating miR‐802 inhibitor to combat nephropathy.     

Expansion of Islet-Resident Macrophages Leads to Inflammation Affecting β Cell Proliferation and Function in Obesity

1. Download high-res image (213KB)
2. Download full-size image

     

A Combination of Proteomic Approaches Identifies A Panel of Circulating Extracellular Vesicle Proteins Related to the Risk of Suffering Cardiovascular Disease in Obese Patients

Plasma‐derived extracellular vesicles (EVs) have been extensively described as putative biomarkers in different diseases. Interestingly, increased levels of EVs subpopulations are well known to associate with obesity. The goal of this study is to identify EVs‐derived biomarkers in plasma from obese patients in order to predict the development of pathological events associated with obesity. Samples are obtained from 22 obese patients and their lean‐matched controls are divided into two cohorts: one for a 2D fluorescence difference gel electrophoresis (2D‐DIGE)‐based study, and the other one for a label free LC–MS/MS‐based approach. EVs are isolated following a serial ultracentrifugation protocol. Twenty‐two and 23 differentially regulated features are detected from 2D‐DIGE and label free LC–MS/MS, respectively; most of them involve in the coagulation and complement cascades. Remarkably, there is an upregulation of complement C4, complement C3, and fibrinogen in obese patients following both approaches, the latter two also validated by 2D‐western‐blotting in an independent cohort. These results correlate with a proinflammatory and prothrombotic state of those individuals. On the other hand, a downregulation of adiponectin leading to an increased risk of suffering cardiovascular diseases has been shown. The results suggest the relevance of plasma‐derived‐EVs proteins as a source of potential biomarkers for the development of atherothrombotic events in obesity.