The perfect storm: obesity, adipocyte dysfunction, and metabolic consequences

Soybean polar lipids differently impact adipose tissue inflammation and the endotoxin transporters LBP and sCD14 in flaxseed vs. palm oil-rich diets

Obesity and type 2 diabetes are nutritional pathologies, characterized by a subclinical inflammatory state. Endotoxins are now well recognized as an important factor implicated in the onset and maintain of this inflammatory state during fat digestion in high-fat diet. As a preventive strategy, lipid formulation could be optimized to limit these phenomena, notably regarding fatty acid profile and PL emulsifier content. Little is known about soybean polar lipid (SPL) consumption associated to oils rich in saturated FA vs. anti-inflammatory omega-3 FA such as α-linolenic acid on inflammation and metabolic endotoxemia. We then investigated in mice the effect of different synthetic diets enriched with two different oils, palm oil or flaxseed oil and containing or devoid of SPL on adipose tissue inflammation and endotoxin receptors. In both groups containing SPL, adipose tissue (WAT) increased compared with groups devoid of SPL and an induction of MCP-1 and LBP was observed in WAT. However, only the high-fat diet in which flaxseed oil was associated with SPL resulted in both higher WAT inflammation and higher circulating sCD14 in plasma. In conclusion, we have demonstrated that LPS transporters LBP and sCD14 and adipose tissue inflammation can be modulated by SPL in high fat diets differing in oil composition. Notably high-flaxseed oil diet exerts a beneficial metabolic impact, however blunted by PL addition. Our study suggests that nutritional strategies can be envisaged by optimizing dietary lipid sources in manufactured products, including fats/oils and polar lipid emulsifiers, in order to limit the inflammatory impact of palatable foods.

Prevalence of diabetes mellitus and impaired glucose metabolism in the adult population of the Basque Country, Spain

AIMS

To assess the prevalence of diabetes mellitus and impaired glucose metabolism in the Basque Country and their relationship with cardiovascular risk factors.

METHODS

A population-based, cross-sectional, cluster sampling design study was carried out in an adult (≥18 years) Basque population. A total of 847 participants completed a questionnaire on personal and family medical history and lifestyle. Anthropometric variables and blood pressure were measured and biochemical analysis and an oral glucose tolerance test (75 g) were also performed.

RESULTS

The total prevalence of diabetes was 10.6% (95% CI 8.65-12.95). Among them 6.3% (95% CI 4.79-8.22) had previously been diagnosed and 4.3% (95% CI 3.04-5.92) were not aware that they had diabetes. Impaired glucose tolerance was present in 7.2% (95% CI 5.53-9.15) and impaired fasting glucose in 3.8% (95% CI 2.64-5.37) of the population. In total, 21.6% of the population had some type of glucose metabolism disturbance, with a higher rate among men (28.3 vs 16.3%; P<0.001) and with the rate increasing with age. Risk factors independently associated with the development of diabetes were: male sex [odds ratio 4.58 (95% CI 2.34-8.97)]; abdominal obesity [odds ratio 2.80 (95% CI 1.47-5.36)]; high triglyceride levels [odds ratio 2.46 (95% CI 1.26-4.81)]; hypertension [odds ratio 2.40 (95% CI 1.16-4.96)]; family history of diabetes [odds ratio 2.30 (95% CI 1.25-4.24)]; high LDL cholesterol levels [odds ratio 1.83 (95% CI 1.01-3.31)] and older age [odds ratio 1.08 (95% CI 1.05-1.10)].

CONCLUSIONS

The prevalence of diabetes in the Basque Country was lower than in Spain and was independently associated with family history of diabetes and with cardiovascular risk factors such as abdominal obesity, hypertension, high LDL cholesterol levels and high triglyceride levels, which were also observed in those with prediabetes.

Markers of Oxidative Stress and Antioxidant Defense in Romanian Patients with Type 2 Diabetes Mellitus and Obesity

Type 2 diabetes mellitus (T2DM) is strongly associated with obesity. The adipose tissue secretes bioactive adipokines leading to low grade inflammation, amplified by oxidative stress, which promotes the formation of advanced glycation end products and eventually leads to dyslipidemia and vascular complications. The aim of this study was to correlate anthropometric, biochemical and oxidative stress parameters in newly diagnosed (ND) T2DM patients and to investigate the role of oxidative stress in T2DM associated with obesity. A group of 115 ND- T2DM patients was compared to a group of 32 healthy subjects in terms of clinical, anthropometric, biochemical and oxidative stress parameters. ND-T2DM patients had significantly lower adiponectin, glutathione (GSH) and gluthatione peroxidase (GPx) and elevated insulin, proinsulin, HOMA-IR index, proinsulin/insulin (P/I) and proinsulin/adiponectin (P/A) ratio, fructosamine, and total oxidant status (TOS). The total body fat mass was positively correlated with total oxidant status (TOS). Positive correlations were found between TOS and glycated hemoglobin (HbA1c), and between TOS and glycaemia. Negative correlations were identified between: GPx and glycaemia, GPx and HbA1c, and also between GSH and fructosamine. The total antioxidant status was negatively correlated with the respiratory burst. The identified correlations suggest the existence of a complex interplay between diabetes, obesity and oxidative stress.

Skeletal muscle insulin resistance: role of mitochondria and other ROS sources

At present, obesity is one of the most important public health problems in the world because it causes several diseases and reduces life expectancy. Although it is well known that insulin resistance plays a pivotal role in the development of type 2 diabetes mellitus (the more frequent disease in obese people) the link between obesity and insulin resistance is yet a matter of debate. One of the most deleterious effects of obesity is the deposition of lipids in non-adipose tissues when the capacity of adipose tissue is overwhelmed. During the last decade, reduced mitochondrial function has been considered as an important contributor to 'toxic' lipid metabolite accumulation and consequent insulin resistance. More recent reports suggest that mitochondrial dysfunction is not an early event in the development of insulin resistance, but rather a complication of the hyperlipidemia-induced reactive oxygen species (ROS) production in skeletal muscle, which might promote mitochondrial alterations, lipid accumulation and inhibition of insulin action. Here, we review the literature dealing with the mitochondria-centered mechanisms proposed to explain the onset of obesity-linked IR in skeletal muscle. We conclude that the different pathways leading to insulin resistance may act synergistically because ROS production by mitochondria and other sources can result in mitochondrial dysfunction, which in turn can further increase ROS production leading to the establishment of a harmful positive feedback loop.

Metabolite profiling can change health-care delivery to obese patients with fatty liver disease: the search for biomarkers

Comorbidities associated with obesity have become a worldwide public health concern. Obesity-associated hepatic steatosis is not benign, and the risk of developing severe liver disease is high. Currently, biopsy is the only clinical tool available for the diagnosis of pathological alterations in the liver. However, the procedure is painful and not without risk. As such, there is a need to identify non-invasive biomarkers of steatosis. There has been considerable progress in this area, but research appears to be limited to measurements of levels of certain parameters in patients with liver impairment relative to those of healthy controls. The clinically relevant aim should be to distinguish, at an early stage, those obese individuals with liver steatosis from those obese individuals without it. Plasma constituents that act as surrogates of altered hepatic energy metabolism in response to food intake are likely candidates. Targeted metabolomics, combined with quantitation of the metabolites involved, has been shown to be an efficient measurement tool. Indeed, the evaluation of exhaled volatile compounds might be sufficient, while other rapid, sensitive, and reproducible methods have been validated in preliminary studies in various clinical settings. Metabolomics methods are promising but require considerable expertise and sophisticated (and expensive) equipment not readily available in all centers. The challenge is to adapt this newly acquired, expanding knowledge to current, reasonably equipped clinical laboratories, while substantially reducing costs. Good outcomes are urgently required if effective prevention programs are to be developed to decrease the prevalence of liver disease.

Increased Adipose and Muscle Insulin Sensitivity Without Changes in Serum Adiponectin in Young Female Collegiate Athletes

BACKGROUND

Effects of endurance training on adipose insulin sensitivity in association with body composition, circulating adipokines, and markers of inflammation have been studied less in young Asian subjects.

METHODS

Adipose insulin sensitivity/resistance was compared between 170 female Japanese collegiate athletes and 311 nonathletes (18-24 years), who underwent measurements of serum adipokines, markers of insulin sensitivity, inflammation, and dual-energy X-ray absorptiometry. Two separate subsamples of two groups of women underwent either a 75-gram oral glucose tolerance test or a standardized meal test, but not both.

RESULTS

As compared with nonathletes, athletes, characterized by higher skeletal muscle mass and lower percentage of body fat (both P < 0.001), had lower adipose insulin resistance (IR) (a product of fasting insulin and nonesterified fatty acid (NEFA) and lower leptin/adiponectin ratio (both P < 0.001). Although athletes had lower postmeal/postglucose insulinemia (P = 0.009 and 0.01, respectively), the two groups did not differ in postmeal percentage NEFA suppression and postmeal/postglucose glycemia, suggesting increased insulin sensitivity in adipose tissue and skeletal muscle, respectively. Serum leptin (P < 0.001) and tumor necrosis factor-α (P = 0.01) were lower in athletes, whereas adiponectin and homeostasis model assessment IR did not differ.

CONCLUSIONS

Endurance training was associated with increased insulin sensitivity in adipose tissue as well as skeletal muscle without changes in circulating adiponectin even in young, normal-weight Japanese women.

Hypolipidemic effects of S-(+)-linalool and essential oil from Cinnamomum osmophloeum ct. linalool leaves in mice

Cinnamomum osmophloeum ( tǔ ròu guì) ct. linalool is one of the chemotypes of the indigenous cinnamon in Taiwan. S-(+)-linalool is the major constituent of leaf essential oil (LEO) of C. osmophloeum ct. linalool. This study aimed to investigate its physiological effects including body weight changes, blood biochemical values, and histopathological changes in mice. The mice were treated with LEO, S-(+)-linalool, and R-(-)-linalool. Results demonstrated similar physiological changes in mice treated with LEO and S-(+)-linalool, but significantly different effects in the body weight, TG, TC and blood glucose of R-(-)-linalool group. S-(+)-linalool-treated mice gained less weight and had significant decrease in blood triglyceride levels. No histopathological changes were observed in livers, kidneys, and spleens of S-(+)-linalool-treated mice. Furthermore, there were no significant differences in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels between S-(+)-linalool-treated mice and the control group. In addition, LEO and S-(+)-linalool significantly inhibited lipid accumulation through down-regulation of 3T3-L1 adipocyte differentiation. Taken together, the results show that LEO and S-(+)-linalool from C. osmophloeum ct. linalool can contribute to body weight management without harmful side effects.

Aqueous seed extract of Hunteria umbellata (K. Schum.) Hallier f. (Apocynaceae) palliates hyperglycemia, insulin resistance, dyslipidemia, inflammation and oxidative stress in high-fructose diet-induced metabolic syndrome in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Hunteria umbellata is used in the management and treatment of diabetes and obesity in Nigeria. This study evaluates the effect of aqueous seed extract of Hunteria umbellata on insulin resistance, dyslipidemia, inflammation and oxidative stress in high-fructose diet-induced metabolic syndrome MATERIALS AND METHODS: Rats were randomized into seven groups (A-G). Control (group A) and group C rats received control diet for nine weeks while rats in groups B, D - G were placed on high-fructose diet for 9 weeks. In addition to the diets, groups C - F rats orally received 400, 100, 200 and 400mg/kg body weight aqueous seed extract of Hunteria umbellata for 3 weeks starting from 6th - 9th week.

RESULTS

High-fructose diet (when compared to control rats) mediated a significant (p<0.05) increase in body weight, body mass index and abdominal circumference. Similarly, levels of blood glucose, insulin, leptin, adiponectin and insulin resistance were increased. It also caused a significant increase in the levels of cholesterol, triglycerides, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, atherogenic index, cardiac index and coronary artery index while high-density lipoprotein cholesterol was decreased significantly. Levels of proinflammatory factor, tumour necrosis factor-α, interleukin-6 and 8 were also increased by the high fructose diet. Moreover, it mediated decrease in activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose 6-phosphate dehydrogenase and level of glutathione reduced. Conversely, levels of malondialdehyde, conjugated dienes, lipid hydroperoxides, protein carbonyl and fragmented DNA were elevated. Aqueous seed extract of Hunteria umbellata significantly ameliorated the high fructose diet-mediated alterations.

CONCLUSIONS

From this study, it is concluded that aqueous seed extract of Hunteria umbellata possesses hypoglycemic, hypolipidemic and antioxidants abilities as evident from its capability to extenuate insulin resistance, dyslipidemia, inflammation and oxidative stress in high-fructose diet-induced metabolic syndrome rats.

Early High-Fat Feeding Induces Alteration of Trace Element Content in Tissues of Juvenile Male Wistar Rats

The primary objective of the current study was to assess the influence of early high-fat feeding on tissue trace element content in young male Wistar rats. Twenty weanling male Wistar rats were divided into two groups fed standard (STD) or high-fat diet (HFD) containing 10 and 31.6 % of total calories from fat, respectively, for 1 month. Serum lipid spectrum, apolipoproteins, glucose, insulin, adiponectin, and leptin levels were assessed. The level of trace elements was estimated using inductively coupled plasma mass spectrometry. High-fat feeding significantly increased epidydimal (EDAT) and retroperitoneal adipose tissue (RPAT), as well as total adipose tissue mass by 34, 103, and 59 %, respectively. Serum leptin levels in HFD animals were twofold higher than those in the control rats. No significant difference in serum lipid spectrum, apolipoproteins, glucose, adiponectin, and insulin was detected between the groups. HFD significantly altered tissue trace element content. In particular, HFD-fed animals were characterized by significantly lower levels of Cu, I, Mn, Se, and Zn in the liver; Cr, V, Co, Cu, Fe, and I content of EDAT; Co, Cu, I, Cr, V, Fe, and Zn concentration in RPAT samples. At the same time, only serum Cu was significantly depressed in HFD-fed animals as compared to the control ones. Hair Co, Mn, Si, and V levels were significantly increased in comparison to the control values, whereas Se and I content was decreased. HFD feeding induced excessive adiposity and altered tissue trace element content in rats without insulin resistance, adiponectin deficiency, and proatherogenic state. Hypothetically, trace element disbalance may precede obesity-associated metabolic disturbances.

MECHANISMS IN ENDOCRINOLOGY: Skeletal muscle lipotoxicity in insulin resistance and type 2 diabetes: a causal mechanism or an innocent bystander?

Dysfunctional adipose tissue is associated with an increased risk of developing type 2 diabetes (T2D). One characteristic of a dysfunctional adipose tissue is the reduced expandability of the subcutaneous adipose tissue leading to ectopic storage of fat in organs and/or tissues involved in the pathogenesis of T2D that can cause lipotoxicity. Accumulation of lipids in the skeletal muscle is associated with insulin resistance, but the majority of previous studies do not prove any causality. Most studies agree that it is not the intramuscular lipids per se that causes insulin resistance, but rather lipid intermediates such as diacylglycerols, fatty acyl-CoAs and ceramides and that it is the localization, composition and turnover of these intermediates that play an important role in the development of insulin resistance and T2D. Adipose tissue is a more active tissue than previously thought, and future research should thus aim at examining the exact role of lipid composition, cellular localization and the dynamics of lipid turnover on the development of insulin resistance. In addition, ectopic storage of fat has differential impact on various organs in different phenotypes at risk of developing T2D; thus, understanding how adipogenesis is regulated, the interference with metabolic outcomes and what determines the capacity of adipose tissue expandability in distinct population groups is necessary. This study is a review of the current literature on the adipose tissue expandability hypothesis and how the following ectopic lipid accumulation as a consequence of a limited adipose tissue expandability may be associated with insulin resistance in muscle and liver.

Clinical utility of metabolic syndrome severity scores: considerations for practitioners

The metabolic syndrome (MetS) is marked by abnormalities in central obesity, high blood pressure, high triglycerides, low high-density lipoprotein-cholesterol, and high fasting glucose and appears to be produced by underlying processes of inflammation, oxidative stress, and adipocyte dysfunction. MetS has traditionally been classified based on dichotomous criteria that deny that MetS-related risk likely exists as a spectrum. Continuous MetS scores provide a way to track MetS-related risk over time. We generated MetS severity scores that are sex- and race/ethnicity-specific, acknowledging that the way MetS is manifested may be different by sex and racial/ethnic subgroup. These scores are correlated with long-term risk for type 2 diabetes mellitus and cardiovascular disease. Clinical use of scores like these provide a potential opportunity to identify patients at highest risk, motivate patients toward lifestyle change, and follow treatment progress over time.

Sigumjang (fermented barley bran) water-soluble extracts inhibit the expression of adipogenic and lipogenic regulators in 3T3-L1 adipocytes

Sigumjang prepared from fermented barley bran is a traditional fermented food found only in the Gyeongsang-do area of South Korea. There have been no studies reported to date despite the potential bioactivities of sigumjang. In this study, the anti-obesity activities of sigumjang extracts (SEs) during 3T3-L1 differentiation into adipocytes were investigated. SEs inhibited adipocyte differentiation by suppressing the CCAAT/enhancer binding protein-β and sterol regulatory element binding protein-1c expression in the early stage of differentiation, followed by the suppression of the peroxisome proliferator-activated receptor-γ, CCAAT/enhancer binding protein-α, and adiponectin. These changes in adipogenic markers induced inhibition of lipogenesis via down-regulation of mainly fatty acid synthase, acetyl-CoA carboxylase, fatty acid binding protein 4, and perilipin. These results were more significant in the extract of sigumjang fermented with isolated Bacillus amyloliquefaciens MFST compared to naturally fermented sigumjang group. SEs can be considered as a useful material for developing food with health benefits and anti-obesity properties.

Obesity and cancer: the role of adipose tissue and adipo-cytokines-induced chronic inflammation

Adipose tissue in addition to its ability to keep lipids is now recognized as a real organ with both metabolic and endocrine functions. Recent studies demonstrated that in obese animals is established a status of adipocyte hypoxia and in this hypoxic state interaction between adipocytes and stromal vascular cells contribute to tumor development and progression. In several tumors such as breast, colon, liver and prostate, obesity represents a poor predictor of clinical outcomes. Dysfunctional adipose tissue in obesity releases a disturbed profile of adipokines with elevated levels of pro-inflammatory factors and a consequent alteration of key signaling mediators which may be an active local player in establishing the peritumoral environment promoting tumor growth and progression. Therefore, adipose tissue hypoxia might contribute to cancer risk in the obese population. To date the precise mechanisms behind this obesity-cancer link is not yet fully understood. In the light of information provided in this review that aims to identify the key mechanisms underlying the link between obesity and cancer we support that inflammatory state specific of obesity may be important in obesity-cancer link.

Defective adaptive thermogenesis contributes to metabolic syndrome and liver steatosis in obese mice

Fatty liver diseases are complications of the metabolic syndrome associated with obesity, insulin resistance and low grade inflammation. Our aim was to uncover mechanisms contributing to hepatic complications in this setting. We used foz/foz mice prone to obesity, insulin resistance and progressive fibrosing non-alcoholic steatohepatitis (NASH). Foz/foz mice are hyperphagic but wild-type (WT)-matched calorie intake failed to protect against obesity, adipose inflammation and glucose intolerance. Obese foz/foz mice had similar physical activity level but reduced energy expenditure. Thermogenic adaptation to high-fat diet (HFD) or to cold exposure was severely impaired in foz/foz mice compared with HFD-fed WT littermates due to lower sympathetic tone in their brown adipose tissue (BAT). Intermittent cold exposure (ICE) restored BAT function and thereby improved glucose tolerance, decreased fat mass and liver steatosis. We conclude that failure of BAT adaptation drives the metabolic complications of obesity in foz/foz mice, including development of liver steatosis. Induction of endogenous BAT function had a significant therapeutic impact on obesity, glucose tolerance and liver complications and is a potential new avenue for therapy of non-alcoholic fatty liver disease (NAFLD).

Inter-relationships between the severity of metabolic syndrome, insulin and adiponectin and their relationship to future type 2 diabetes and cardiovascular disease

BACKGROUND

The severity of the metabolic syndrome (MetS) is related to future incidence of type 2 diabetes (T2DM) and cardiovascular disease (CVD). However, the relationship between MetS severity and levels of fasting insulin and adiponectin-markers of insulin resistance-is unclear.

METHODS

We used linear and logistic regression to analyze data from 711 participants of the Princeton Lipid Research Cohort with information regarding levels of insulin, adiponectin and MetS severity during 1998-2003 (mean age 39.5 years); 595 participants had MetS severity data from childhood (1973-1976, mean age 12.9 years) and 417 had updated disease status from 2010 to 2014 (mean age 50.9 years).

RESULTS

Childhood MetS Z-scores were positively associated with adult insulin levels (P<0.001) and negatively associated with adiponectin levels (P=0.01). In individual analyses, higher insulin levels and MetS Z-score as adults were related to higher odds of incident diabetes and CVD over the next 11.2 years (all P<0.001), whereas lower adiponectin levels were only related to odds of future T2DM (P<0.0001). In a model including insulin, adiponectin and MetS Z-score, adiponectin was not linked to future disease; both insulin (P=0.027) and MetS Z-score (P=0.002) were related to risk of future T2DM, while only MetS Z-score was related to future CVD (P<0.001).

CONCLUSIONS

The severity of MetS exhibits long-term links to levels of insulin and adiponectin, suggesting potential genetic and environmental influences on insulin resistance over time. As a long-term predictor of T2DM and CVD, the severity of MetS exhibited consistent independent correlations. This supports clinical utility in evaluating MetS severity as a predictor of risk for future disease.

High fat diet-induced TGF-β/Gbb signaling provokes insulin resistance through the tribbles expression

Hyperglycemia, hyperlipidemia, and insulin resistance are hallmarks of obesity-induced type 2 diabetes, which is often caused by a high-fat diet (HFD). However, the molecular mechanisms underlying HFD-induced insulin resistance have not been elucidated in detail. In this study, we established a Drosophila model to investigate the molecular mechanisms of HFD-induced diabetes. HFD model flies recapitulate mammalian diabetic phenotypes including elevated triglyceride and circulating glucose levels, as well as insulin resistance. Expression of glass bottom boat (gbb), a Drosophila homolog of mammalian transforming growth factor-β (TGF-β), is elevated under HFD conditions. Furthermore, overexpression of gbb in the fat body produced obese and insulin-resistant phenotypes similar to those of HFD-fed flies, whereas inhibition of Gbb signaling significantly ameliorated HFD-induced metabolic phenotypes. We also discovered that tribbles, a negative regulator of AKT, is a target gene of Gbb signaling in the fat body. Overexpression of tribbles in flies in the fat body phenocopied the metabolic defects associated with HFD conditions or Gbb overexpression, whereas tribbles knockdown rescued these metabolic phenotypes. These results indicate that HFD-induced TGF-β/Gbb signaling provokes insulin resistance by increasing tribbles expression.

Swertiamarin ameliorates oleic acid induced lipid accumulation and oxidative stress by attenuating gluconeogenesis and lipogenesis in hepatic steatosis

Swertiamarin, a bitter secoiridoid glycoside, is an antidiabetic drug with lipid lowering activity meliorates insulin resistance in Type 2 Diabetes condition. Therefore, the study was designed to explore the antioxidant and hypolipidemic activity of swertiamarin in ameliorating NAFLD caused due to hepatic lipid accumulation, inflammation and insulin resistance. Steatosis was induced in HepG2 cells by supplementing 1mM oleic acid (OA) for 24h which was marked by significant accumulation of lipid droplets. This was determined by Oil Red O (ORO) staining and triglyceride accumulation. Swertiamarin (25μg/ml) decreased triglyceride content by 2 folds and effectively reduced LDH release (50%) activity by protecting membrane integrity thus, preventing apoptosis evidenced by reduced cleavage of Caspase 3 and PARP1. We observed that swertiamarin significantly increased the expressions of major insulin signaling proteins like Insulin receptor (IR), PI(3)K, pAkt with concomitant reduction in p307 IRS-1. AMPK was activated by swertiamarin action, thus restoring insulin sensitivity in hepatocytes. In addition, qPCR results confirmed OA up-regulated Sterol Regulatory Element Binding Protein (SREBP)-1c and fatty acid synthase (FAS), resulting in increased fatty acid synthesis. Swertiamarin effectively modulated PPAR-α, a major potential regulator of carbohydrate metabolism which, in turn, decreased the levels of the gluconeogenic enzyme PEPCK, further restricting hepatic glucose production and fatty acid synthesis. Cumulatively, swertiamarin targets potential metabolic regulators AMPK and PPAR-α, through which it regulates hepatic glycemic burden, fat accumulation, insulin resistance and ROS in hepatic steatosis which emphasizes clinical significance of swertiamarin in regulating metabolism and as a suitable candidate for treating NAFLD.

Systems view of adipogenesis via novel omics-driven and tissue-specific activity scoring of network functional modules

The investigation of the complex processes involved in cellular differentiation must be based on unbiased, high throughput data processing methods to identify relevant biological pathways. A number of bioinformatics tools are available that can generate lists of pathways ranked by statistical significance (i.e. by p-value), while ideally it would be desirable to functionally score the pathways relative to each other or to other interacting parts of the system or process. We describe a new computational method (Network Activity Score Finder - NASFinder) to identify tissue-specific, omics-determined sub-networks and the connections with their upstream regulator receptors to obtain a systems view of the differentiation of human adipocytes. Adipogenesis of human SBGS pre-adipocyte cells in vitro was monitored with a transcriptomic data set comprising six time points (0, 6, 48, 96, 192, 384 hours). To elucidate the mechanisms of adipogenesis, NASFinder was used to perform time-point analysis by comparing each time point against the control (0 h) and time-lapse analysis by comparing each time point with the previous one. NASFinder identified the coordinated activity of seemingly unrelated processes between each comparison, providing the first systems view of adipogenesis in culture. NASFinder has been implemented into a web-based, freely available resource associated with novel, easy to read visualization of omics data sets and network modules.

Roux-en-Y Gastric Bypass Acutely Decreases Protein Carbonylation and Increases Expression of Mitochondrial Biogenesis Genes in Subcutaneous Adipose Tissue

BACKGROUND

Mitochondrial dysfunction in adipose tissue has been implicated as a pathogenic step in the development of type 2 diabetes mellitus (T2DM). In adipose tissue, chronic nutrient overload results in mitochondria driven increased reactive oxygen species (ROS) leading to carbonylation of proteins that impair mitochondrial function and downregulation of key genes linked to mitochondrial biogenesis. In patients with T2DM, Roux-en-Y gastric bypass (RYGB) surgery leads to improvements in glycemic profile prior to significant weight loss. Consequently, we hypothesized that improved glycemia early after RYGB would be paralleled by decreased protein carbonylation and increased expression of genes related to mitochondrial biogenesis in adipose tissue.

METHODS

To evaluate this hypothesis, 16 obese individuals were studied before and 7-8 days following RYGB and adjustable gastric banding (AGB). Subcutaneous adipose tissue was obtained pre- and post-bariatric surgery as well as from eight healthy, non-obese individual controls.

RESULTS

Prior to surgery, adipose tissue expression of PGC1α, NRF1, Cyt C, and eNOS (but not Tfam) showed significantly lower expression in the obese bariatric surgery group when compared to lean controls (p < 0.05). Following RYGB, but not after AGB, patients showed significant decrease in HOMA-IR, reduction in adipose protein carbonylation, and increased expression of genes linked to mitochondrial biogenesis.

CONCLUSIONS

These results suggest that rapid reduction in protein carbonylation and increased mitochondrial biogenesis may explain postoperative metabolic improvements following RYGB.

Does Metabolically Healthy Obesity Exist?

The relationship between obesity and other metabolic diseases have been deeply studied. However, there are clinical inconsistencies, exceptions to the paradigm of "more fat means more metabolic disease", and the subjects in this condition are referred to as metabolically healthy obese (MHO).They have long-standing obesity and morbid obesity but can be considered healthy despite their high degree of obesity. We describe the variable definitions of MHO, the underlying mechanisms that can explain the existence of this phenotype caused by greater adipose tissue inflammation or the different capacity for adipose tissue expansion and functionality apart from other unknown mechanisms. We analyze whether these subjects improve after an intervention (traditional lifestyle recommendations or bariatric surgery) or if they stay healthy as the years pass. MHO is common among the obese population and constitutes a unique subset of characteristics that reduce metabolic and cardiovascular risk factors despite the presence of excessive fat mass. The protective factors that grant a healthier profile to individuals with MHO are being elucidated.

Nonalcoholic Fatty Liver Disease is Associated with Increased Carotid Intima-Media Thickness in Type 1 Diabetic Patients

A growing body of evidence suggests that NAFLD is associated with an increased risk of incident CVD events both in patients without diabetes and in those with type 2 diabetes (T2DM). However, no published data are available regarding the association between NAFLD and C-IMT in T1DM. A total of 722 patients (371 men) with T1DM were included in this cross-sectional study. The main outcome measures were detection of NAFLD, C-IMT and classical risk factors. The mean age of the subjects was 46.2 years, and 51.1% were male. The prevalence of NAFLD was 15.9%. NAFLD patients had a markedly greater C-IMT (0.81 ± 0.25 vs. 0.69 ± 0.18 mm; p < 0.001) and frequency of carotid plaque (28.9% vs. 16.9%; p < 0.05) than those without fatty liver. Moreover, the differences in C-IMT remained after adjusting for potential confounders. A stepwise linear regression analysis revealed that age (standardized β, 0.326; p < 0.001), NAFLD (standardized β, 0.151, p < 0.001), and hsCRP (standardized β, 0.115, p = 0.008) were independently associated with C-IMT in all subjects. Our data show NAFLD is associated with elevated C-IMT in T1DM independent of conventional cardiovascular disease risk factors.

Monocyte chemoattractant protein-1, transforming growth factor-beta1, nerve growth factor, resistin and hyaluronic acid as serum markers: comparison between recurrent acute and chronic pancreatitis

BACKGROUND

Diagnostic parameters that can predict the presence of chronic pancreatitis (CP) in patients with recurrent pain due to pancreatitis would help to direct appropriate therapy. This study aimed to compare the serum levels of monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-beta1 (TGF-beta1), nerve growth factor (NGF), resistin and hyaluronic acid (HA) in patients with recurrent acute pancreatitis (RAP) and CP to assess their ability to differentiate the two conditions.

METHODS

Levels of serum markers assessed by enzyme-linked immunosorbent assay (ELISA) were prospectively compared in consecutive patients with RAP, CP and in controls, and stepwise discriminant analysis was performed to identify the markers differentiating RAP from CP.

RESULTS

One hundred and thirteen consecutive patients (RAP=32, CP=81) and 78 healthy controls were prospectively enrolled. The mean (SD) age of the patients was 32.0 (14.0) years; 89 (78.8%) were male. All markers were significantly higher in CP patients than in the controls (P<0.001); MCP-1, NGF and HA were significantly higher in RAP patients than in the controls (P<0.001). Stepwise discriminant analysis showed significant difference (P=0.002) between RAP and CP for resistin with an accuracy of 61.9%, discriminant scores of ≤-0.479 and ≥0.189 indicating RAP and CP, respectively. The other markers had no differential value between RAP and CP.

CONCLUSION

Serum resistin is a promising marker to differentiate between RAP and CP and needs validation in future studies, especially in those with early CP.

Ion Channels in Obesity: Pathophysiology and Potential Therapeutic Targets

Obesity is a multifactorial disease related to metabolic disorders and associated with genetic determinants. Currently, ion channels activity has been linked to many of these disorders, in addition to the central regulation of food intake, energetic balance, hormone release and response, as well as the adipocyte cell proliferation. Therefore, the objective of this work is to review the current knowledge about the influence of ion channels in obesity development. This review used different sources of literature (Google Scholar, PubMed, Scopus, and Web of Science) to assess the role of ion channels in the pathophysiology of obesity. Ion channels present diverse key functions, such as the maintenance of physiological homeostasis and cell proliferation. Cell biology and pharmacological experimental evidences demonstrate that proliferating cells exhibit ion channel expression, conductance, and electrical properties different from the resting cells. Thereby, a large variety of ion channels has been identified in the pathogenesis of obesity such as potassium, sodium, calcium and chloride channels, nicotinic acetylcholine receptor and transient receptor potential channels. The fundamental involvement of these channels on the generation of obesity leads to the progress in the knowledge about the mechanisms responsible for the obesity pathophysiology, consequently emerging as new targets for pharmacological modulation.

Analysis of Genes Involved in Body Weight Regulation by Targeted Re-Sequencing

Introduction

Genes involved in body weight regulation that were previously investigated in genome-wide association studies (GWAS) and in animal models were target-enriched followed by massive parallel next generation sequencing.

Methods

We enriched and re-sequenced continuous genomic regions comprising FTO, MC4R, TMEM18, SDCCAG8, TKNS, MSRA and TBC1D1 in a screening sample of 196 extremely obese children and adolescents with age and sex specific body mass index (BMI) ≥ 99^th percentile and 176 lean adults (BMI ≤ 15^th percentile). 22 variants were confirmed by Sanger sequencing. Genotyping was performed in up to 705 independent obesity trios (extremely obese child and both parents), 243 extremely obese cases and 261 lean adults.

Results and Conclusion

We detected 20 different non-synonymous variants, one frame shift and one nonsense mutation in the 7 continuous genomic regions in study groups of different weight extremes. For SNP Arg695Cys (rs58983546) in TBC1D1 we detected nominal association with obesity (p_TDT = 0.03 in 705 trios). Eleven of the variants were rare, thus were only detected heterozygously in up to ten individual(s) of the complete screening sample of 372 individuals. Two of them (in FTO and MSRA) were found in lean individuals, nine in extremely obese. In silico analyses of the 11 variants did not reveal functional implications for the mutations. Concordant with our hypothesis we detected a rare variant that potentially leads to loss of FTO function in a lean individual. For TBC1D1, in contrary to our hypothesis, the loss of function variant (Arg443Stop) was found in an obese individual. Functional in vitro studies are warranted.

Hirsutenone Directly Targets PI3K and ERK to Inhibit Adipogenesis in 3T3-L1 Preadipocytes

Adipogenesis is a key driver of the expansion of adipose tissue mass that causes obesity. Hirsutenone (HST) is an active botanical diarylheptanoid present in Alnus species. In this study, we evaluated the effects of HST on adipogenesis, its mechanisms of action and the molecular targets involved. Using Oil Red O staining, we observed that HST dose-dependently suppresses lipid accumulation during adipogenesis in 3T3-L1 preadipocytes, concomitant with a decrease in peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα) and fatty acid synthase (FAS) protein expression. This inhibitory effect was largely limited to the early stage of adipogenesis, which includes mitotic clonal expansion (MCE), as evidenced by delayed cell cycle entry of preadipocytes from G1 to S phase. Furthermore, the regulation of MCE was accompanied by suppression of phosphatidylinositol 3-kinase (PI3K) and extracellular-regulated kinase (ERK) activity. HST was also shown to bind directly to PI3K and ERK1 in a non-ATP competitive manner. Our results suggest that HST attenuates adipogenesis by directly targeting PI3K and ERK during MCE in 3T3-L1 preadipocytes, underscoring the potential therapeutic application of HST in preventing obesity.

Biomarkers of Metabolic Syndrome: Biochemical Background and Clinical Significance

Biomarkers of the metabolic syndrome are divided into four subgroups. Although dividing them in groups has some limitations, it can be used to draw some conclusions. In a first part, the dyslipidemias and markers of oxidative stress are discussed, while inflammatory markers and cardiometabolic biomarkers are reviewed in a second part. For most of them, the biochemical background and clinical significance are discussed, although here also a well-cut separation cannot always be made. Altered levels cannot always be claimed as the cause, risk, or consequence of the syndrome. Several factors are interrelated to each other and act in a concerted, antagonistic, synergistic, or modulating way. Most important conclusions are summarized at the end of every reviewed subgroup. Genetic biomarkers or influences of various food components on concentration levels are not included in this review article.

Protective effects of Egyptian cloudy apple juice and apple peel extract on lipid peroxidation, antioxidant enzymes and inflammatory status in diabetic rat pancreas

Background

Apples possess rich content of varied polyphenolic compounds showing a variety of biological activities that may ascribe to worthy effects against some chronic diseases. The present study was designed to assess the protective effects of the cloudy apple juice (CAJ) and apple peel extract (APE) of Egyptian Anna apple on the complications in experimental diabetes.

Materials and methods

Four groups were studied. Diabetes was induced by a single dose of streptozotocin (STZ) to only three groups of albino Wistar rats. Two of the diabetic groups received either CAJ or APE for 21 days. At the end of the study, lipid profile parameters were measured in serum while lipid peroxidation (LPO) level, antioxidant enzyme activities and inflammatory markers were evaluated in pancreas tissue samples. The gas chromatography–mass spectrometry (GC-MS) analysis of phenolic compounds found in CAJ and APE was carried out. Moreover, total phenolic content of CAJ and APE were measured.

Results

The significant increase of blood glucose level, serum total cholesterol (TC), triglycerides (TG), low- density lipoprotein cholesterol (LDL-C), and very low-density lipoprotein (VLDL) levels, in addition to tissue malondialdehyde (MDA), nuclear factor kappa B (NF-kB), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8) levels, but a significant decrease in high-density lipoprotein cholesterol (HDL-C), and the activity of pancreatic antioxidant enzymes were the remarkably parameters observed in diabetic control rats. Dissimilarly, oral supplementation of 15 ml/kg CAJ and 1 g/kg APE for 21 days resulted in a significant decrease in fasting blood glucose, serum TC, TG, LDL-C, VLDL-C and tissue MDA, NF-kB, TNF-α, IL-6, IL-8 levels coupled with a significant elevation of HDL-C and antioxidant enzymes’ activity when compared with diabetic control animals.

Conclusions

The results indicate that Egyptian CAJ and APE supplementation may have protective effects against deleterious complications of diabetes mellitus.

Ramie Leaf Extracts Suppresses Adipogenic Differentiation in 3T3-L1 Cells and Pig Preadipocytes

The present study was carried out to evaluate the anti-obesity effect of different concentrations of extracts of hot air-dried ramie leaf (HR) and freeze-dried ramie leaf (FR) in 3T3-L1 cells and pig preadipocytes. To analyze the effect on cell proliferation, cells were treated with 25 μg/mL or 100 μg/mL HR or FR extract for 2 days. Cell differentiation was evaluated by measuring glycerol-3-phosphate dehydrogenase and lipoprotein lipase (LPL) activities and intracellular triglyceride content. Treatment with either HR or FR extracts inhibited the proliferation of 3T3-L1 cells and pig preadipocytes in a dose-dependent manner. HR extract treatment inhibited the differentiation of both cell types more effectively than FR treatment. The extent of triglyceride accumulation decreased significantly in both cells following either HR or FR treatment. Furthermore, LPL activity significantly decreased after treatment with HR or FR extract. These results indicated that HR and FR extracts may inhibit proliferation and differentiation of 3T3-L1 cells and pig preadipocytes. Further studies are needed to explore the anti-obesity effect of HR and FR extracts.

Severity of the metabolic syndrome as a predictor of type 2 diabetes between childhood and adulthood: the Princeton Lipid Research Cohort Study

AIMS/HYPOTHESIS

The aim of this study was to determine the long-term associations of a sex- and race/ethnicity-specific metabolic syndrome (MetS) severity z score from childhood and adulthood with a future diagnosis of type 2 diabetes mellitus.

METHODS

We performed a prospective cohort study with evaluations from the Cincinnati Clinic of the National Heart Lung and Blood Institute Lipids Research Clinic (LRC) 1973-1976 and Princeton Follow-up Study (PFS) 1998-2003, and further disease status from the Princeton Health Update (PHU) 2010-2014. We assessed MetS severity as a predictor of incident type 2 diabetes among 629 cohort participants assessed at both the LRC and PFS and 354 participants at the PHU.

RESULTS

Cohort participants had a mean age of 12.9 years at baseline (LRC), 38.4 years at the PFS and 49.6 years at the most recent follow-up. Childhood MetS z scores were associated with adult MetS z scores (p < 0.01). Compared with individuals who were disease-free at all time-points, those who developed type 2 diabetes by 1998-2003 and 2010-2014 had higher MetS severity z scores in childhood (p < 0.05). For every one-unit elevation in childhood MetS z score, the OR of developing future type 2 diabetes was 2.7 for incident disease by a mean age of 38.5 years (p < 0.01) and 2.8 for incident disease by a mean age of 49.6 years (p < 0.05). Regarding associations with the change in z score from childhood to adulthood, for every one-unit increase in MetS z score over time the OR of developing incident type 2 diabetes by a mean age of 49.6 years was 7.3 (p < 0.01).

CONCLUSIONS/INTERPRETATION

The severity of MetS in childhood was associated with the incidence of adult type 2 diabetes and the degree of increase in this severity predicted future disease. These findings provide evidence of potential clinical utility in assessing MetS severity to detect risk and follow clinical progress over time.

Shikonin inhibits adipogenic differentiation via regulation of mir-34a-FKBP1B

Shikonin is a naturally occurring naphthoquinone pigment and a major constituent present in Lithospermum erythrorhizon. Since microRNAs (miRNAs) are one of the key post-transcriptional regulators of adipogenesis, their manipulation represents a potential new strategy to inhibit adipogenesis. Our aim was to investigate shikonin-dependent inhibition of adipogenesis with an emphasis on miRNA-related processes. Mir-34a increased during induced adipogenesis, and this was suppressed in the presence of shikonin. mRNA expression of FKBP1B, a suggested target of mir-34a according to bioinformatics studies, decreased during adipogenesis, but was recovered by shikonin treatment, which reversely correlated with mir-34a expression. A mir-34a inhibitor suppressed MDI-induced adipogenesis by blocking PPARγ and C/EBPα expression, while suppression of mir-34a recovered MDI-induced down-regulation of FKBP1B expression. A mir-34a mimic decreased FKBP1B mRNA expression in 3T3-L1 preadipocytes. We also observed that mir-34a bound directly to the 3'-untranslated region of FKBP1B. Finally, FKBP1B overexpression attenuated MDI-induced adipogenesis, PPARγ, and C/EBPα expression. These results suggest that mir-34a regulates adipogenesis by targeting FKBP1B expression. Our findings reveal that shikonin prevents adipogenesis by blocking the mir-34a-FKBP1B pathway which represents a promising potential target for preventing obesity.

Excess of free fatty acids as a cause of metabolic dysfunction in skeletal muscle

Obesity is often associated with metabolic impairments in peripheral tissues. Evidence suggests an excess of free fatty acids (FFA) as one factor linking obesity and related pathological conditions and the impact of FFA overload on skeletal muscle metabolism is described herein. Obesity is associated with dysfunctional adipose tissue unable to buffer the flux of dietary lipids. Resulting increased levels and fluxes of plasma FFA lead to ectopic lipid deposition and lipotoxicity. FFA accumulated in skeletal muscle are associated with insulin resistance and overall cellular dysfunction. Mechanisms supposed to be involved in these conditions include the Randle cycle, intracellular accumulation of lipid metabolites, inflammation and mitochondrial dysfunction or mitochondrial stress. These mechanisms are described and discussed in the view of current experimental evidence with an emphasis on conflicting theories of decreased vs. increased mitochondrial fat oxidation associated with lipid overload. Since different types of FFA may induce diverse metabolic responses in skeletal muscle cells, this review also focuses on cellular mechanisms underlying the different action of saturated and unsaturated FFA.

Inter-relationships of the chronobiotic, melatonin, with leptin and adiponectin: implications for obesity

Obesity and its medical complications represent a significant problem throughout the world. In recent decades, mechanisms underlying the progression of obesity have been intensively examined. The involvement of both the behavioral aspects, such as calorie-rich diet, low physical activity and sleep deprivation, and the intrinsic factors, including adipose tissue deregulation, chronic inflammation, oxidative stress, and chronodisruption, has been identified. The circadian disturbances of the adipose tissue endocrine function have been correlated with obesity. Leptin and adiponectin are adipokines strongly associated with glucose and lipid metabolism and with energy balance. Their synthesis and secretion display circadian rhythms that are disturbed in the obese state. Hyperleptinemia resulting in leptin resistance, and hypo-adiponectinemia have been linked to the pathophysiology of the obesity-related disorders. A deficiency of melatonin, one of the consequences of sleep deprivation, has also been demonstrated to correlate with obesity. Melatonin is a pineal secretory product involved in numerous actions, such as regulation of internal biological clocks and energy metabolism, and it functions as an antioxidant and as an anti-inflammatory agent. There exists a substantial amount of evidence supporting the beneficial effects of melatonin supplementation on obesity and its complications. In the current review, the results of studies related to the interactions between melatonin, and both leptin and adiponectin are discussed. Despite the existence of some inconsistencies, melatonin has been found to normalize the expression and secretion patterns of both adipokines. These results support the concept of melatonin as a potential therapeutic agent for obesity and related disorders.

Retinoic Acid Inhibits Adipogenesis Modulating C/EBPβ Phosphorylation and Down Regulating Srebf1a Expression

Adipogenesis comprises a complex network of signaling pathways and transcriptional cascades; the GSK3β-C/EBPβ-srebf1a axis is a critical signaling pathway at early stages leading to the expression of PPARγ2, the master regulator of adipose differentiation. Previous work has demonstrated that retinoic acid inhibits adipogenesis affecting different signaling pathways. Here, we evaluated the anti-adipogenic effect of retinoic acid on the adipogenic transcriptional cascade, and the expression of adipogenic genes cebpb, srebf1a, srebf1c, pparg2, and cebpa. Our results demonstrate that retinoic acid blocks adipose differentiation during commitment, returning cells to an apparent non-committed state, since they have to be newly induced to adipose conversion after the retinoid is removed from the culture medium. Retinoic acid down regulates the expression of the adipogenic genes, srebf1a, srebf1c, pparg2, and cebpa; however, it did not down regulate the expression of cebpb, but it inhibited C/EBPβ phosphorylation at Thr188, a critical step for the progression of the adipogenic program. We also found that RA inhibition of adipogenesis did not increase the expression of dlk1, the gene encoding for Pref1, a well-known anti-adipogenic factor.

Obesity and cancer phenotype: Is angiogenesis a missed link?

Obesity remains nowadays one of the main threats to human health, being a problem of worldwide proportions. It is characterized by augmented storage of fatty acids in an enlarged adipose tissue. This process is possible thanks to a rich capillary network, supported by a mechanism that has also a crucial role on cancer: angiogenesis. Given that several studies point obesity as a risk factor for cancer development, angiogenesis may be approached as the missed link between these two pathologies. Understanding the different pathways behind angiogenesis becomes essential to break this link by developing new anti-angiogenic therapies or improving the actual ones. In the first phase, this paper will focus the structural and cellular changes that adipose tissue suffers in obesity. Then, the main pro-angiogenic players will be reviewed, taking into account the pathways that explain their putative role in obesity-cancer link. Finally, the clinical implications of the presented mechanisms will also be regarded, being the main focus on the anti-angiogenic therapies.

Perilipin 4 in human skeletal muscle: localization and effect of physical activity

Perilipins (PLINs) coat the surface of lipid droplets and are important for the regulation of lipid turnover. Knowledge about the physiological role of the individual PLINs in skeletal muscle is limited although lipid metabolism is very important for muscle contraction. To determine the effect of long-term exercise on PLINs expression, 26 middle-aged, sedentary men underwent 12 weeks combined endurance and strength training intervention. Muscle biopsies from m. vastus lateralis and subcutaneous adipose tissue were taken before and after the intervention and total gene expression was measured with deep mRNA sequencing. PLIN4 mRNA exhibited the highest expression of all five PLINs in both tissues, and the expression was significantly reduced after long-term exercise in skeletal muscle. Moreover, PLIN4 mRNA expression levels in muscle correlated with the expression of genes involved in de novo phospholipid biosynthesis, with muscular content of phosphatidylethanolamine and phosphatidylcholine, and with the content of subsarcolemmal lipid droplets. The PLIN4 protein was mainly located at the periphery of skeletal muscle fibers, with higher levels in slow-twitch as compared to fast-twitch skeletal muscle fibers. In summary, we report reduced expression of PLIN4 after long-term physical activity, and preferential slow-twitch skeletal muscle fibers and plasma membrane-associated PLIN4 location.

The inhibitory effects of quercetin on obesity and obesity-induced inflammation by regulation of MAPK signaling

Quercetin is a flavonoid found in fruits, vegetables, leaves and grains. It has inhibitory, antiviral, antiasthma, anticancer and antiinflammatory effects. Research has suggested that obesity is linked to metabolic disorders. In this study, we examined the inhibitory effect of quercetin on lipid accumulation and obesity-induced inflammation using 3T3-L1, RAW264.7, zebrafish and mouse models. Quercetin suppressed protein levels of the key adipogenic factors C/EBPβ, C/EBPα, PPARγ and FABP4 and the TG-synthesis enzymes lipin1, DGAT1 and LPAATθ. Activation of m-TOR and p70S6K, which are related to insulin and adipogenesis, was down-regulated during adipogenesis in 3T3-L1 cells. Recent research suggested that MAPK signaling factors were involved in adipogenesis and inflammation and that the adipokines MCP-1 and TNF-α attracted macrophages into adipose tissue. Our data showed that quercetin inhibited the MAPK signaling factors ERK1/2, JNK and p38MAPK and MCP-1 and TNF-α in adipocytes and macrophages. Quercetin also inhibited secretion of the inflammatory cytokines IL-1β and IL-6 and stimulated that of IL-10, an antiinflammatory cytokine. In this study, we confirmed the inhibitory effects of quercetin in adipogenesis and inflammation using a mouse model. In mice, quercetin reduced body weight (almost 40%) and suppressed expression of adipogenic, lipogenic and inflammation-related cytokines. Our data demonstrated that quercetin inhibits lipid accumulation and obesity-induced inflammation in the cell and animal models. Our study suggested that quercetin may represent a potential therapeutic agent for other metabolic disorders by regulating obesity and obesity-induced inflammation.

Tumor Necrosis Factor-Α, Interleukin-6, C-Reactive Protein Levels and Insulin Resistance Associated with Type 2 Diabetes in Abdominal Obesity Women

We aim to investigate the association between elevated tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and high sensitivity-C-reactive protein (hs-CRP) with type 2 diabetes mellitus (T2DM) in abdominal obesity (AO) women subjects. A total of 428 AO subjects (age 48.4 ± 10.2 years), and 107 non-AO women subjects (age 48.8 ± 11.8 years) were enrolled for the all biochemistry testing, inflammatory cytokines, fasting insulin and Homeostasis Model Assessment of insulin resistance (HOMA-IR). Body mass index, waist circumference (WC), blood pressure (BP), plasma glucose (Glu), triglyceride (TG), insulin, HOMA-IR and inflammatory cytokines were significantly higher and lower total antioxidant capacity, HDL-C in AO subjects (p < 0.05). WC was significantly correlated with BP, Glu, TG, LDL-C, insulin, HOMA-IR, TNF-α, IL-6 and negative correlation with HDL-C in AO subjects. Elevation of TNF-α, IL-6, hs-CRP and insulin resistance were significantly associated with T2DM in AO subjects, after adjusting with insulin resistance, increased oxidative stress, elevated TG and reduced HDL-C by using multiple logistic regression analysis. In conclusions, elevation of inflammatory cytokines, oxidative stress and insulin resistance were associated with T2DM in AO women subjects. These inflammatory cytokines are positively associated with T2DM and may have a causal relation with an increased oxidative stress and insulin resistance in these AO women subjects.

Yeast with bacteriocin from ruminal bacteria enhances glucose utilization, reduces ectopic fat accumulation, and alters cecal microbiota in dietary-induced obese mice

BACKGROUND

This study investigated the effect of yeast with bacteriocin (YB) on the homeostasis of lipid and glucose in diet-induced obese (DIO) mice. Seven-week-old C57BL/6 male mice were fed with a Western diet for 24 weeks to induce obesity. These DIO mice were randomly assigned to 2 groups: obese control (WS) and WYB [0.125 μg YB per g body weight (BW)]. YB was administered daily to the WYB mice in the last 4 weeks, while an equal volume of normal saline was administered to the WS mice.

RESULTS

YB caused a significant reduction in BW, and in plasma levels of total cholesterol and glucose. Less hepatic lipid accumulation and smaller adipocytes were observed in WYB mice. WYB mice had higher lipid catabolism in liver and adipose tissue. Compared with WS mice, WYB mice had higher glycolysis in the liver and muscles. YB suppressed hepatic GLUT5 expression, altered the composition of cecal microbiota, and also caused more efficient carbohydrate utilization for energy expenditure.

CONCLUSION

YB resulted in body weight loss, promoted lipid catabolism and carbohydrate utilization; it also modulated cecal microbiota, and therefore partially improved the health of obese mice.