Inflammatory lipid mediators in adipocyte function and obesity

The PGE2 EP3 Receptor Regulates Diet-Induced Adiposity in Male Mice

Mice carrying a targeted disruption of the prostaglandin E2 (PGE2) E-prostanoid receptor 3 (EP3) gene, Ptger3, were fed a high-fat diet (HFD), or a micronutrient matched control diet, to investigate the effects of disrupted PGE2-EP3 signaling on diabetes in a setting of diet-induced obesity. Although no differences in body weight were seen in mice fed the control diet, when fed a HFD, EP3(-/-) mice gained more weight relative to EP3(+/+) mice. Overall, EP3(-/-) mice had increased epididymal fat mass and adipocyte size; paradoxically, a relative decrease in both epididymal fat pad mass and adipocyte size was observed in the heaviest EP3(-/-) mice. The EP3(-/-) mice had increased macrophage infiltration, TNF-α, monocyte chemoattractant protein-1, IL-6 expression, and necrosis in their epididymal fat pads as compared with EP3(+/+) animals. Adipocytes isolated from EP3(+/+) or EP3(-/-) mice were assayed for the effect of PGE2-evoked inhibition of lipolysis. Adipocytes isolated from EP3(-/-) mice lacked PGE2-evoked inhibition of isoproterenol stimulated lipolysis compared with EP3(+/+). EP3(-/-) mice fed HFD had exaggerated ectopic lipid accumulation in skeletal muscle and liver, with evidence of hepatic steatosis. Both blood glucose and plasma insulin levels were similar between genotypes on a control diet, but when fed HFD, EP3(-/-) mice became hyperglycemic and hyperinsulinemic when compared with EP3(+/+) fed HFD, demonstrating a more severe insulin resistance phenotype in EP3(-/-). These results demonstrate that when fed a HFD, EP3(-/-) mice have abnormal lipid distribution, developing excessive ectopic lipid accumulation and associated insulin resistance.

Human lysosomal acid lipase inhibitor lalistat impairs Mycobacterium tuberculosis growth by targeting bacterial hydrolases

Lalistat inhibits growth of Mycobacterium tuberculosis in bacterial culture as well as in infected macrophages.

Age and metabolic risk factors associated with oxidatively damaged DNA in human peripheral blood mononuclear cells

Aging is associated with oxidative stress-generated damage to DNA and this could be related to metabolic disturbances. This study investigated the association between levels of oxidatively damaged DNA in peripheral blood mononuclear cells (PBMCs) and metabolic risk factors in 1,019 subjects, aged 18-93 years. DNA damage was analyzed as strand breaks by the comet assay and levels of formamidopyrimidine (FPG-) and human 8-oxoguanine DNA glycosylase 1 (hOGG1)-sensitive sites There was an association between age and levels of FPG-sensitive sites for women, but not for men. The same tendency was observed for the level of hOGG1-sensitive sites, whereas there was no association with the level of strand breaks. The effect of age on oxidatively damaged DNA in women disappeared in multivariate models, which showed robust positive associations between DNA damage and plasma levels of triglycerides, cholesterol and glycosylated hemoglobin (HbA_1c). In the group of men, there were significant positive associations between alcohol intake, HbA_1c and FPG-sensitive sites in multivariate analysis. The levels of metabolic risk factors were positively associated with age, yet only few subjects fulfilled all metabolic syndrome criteria. In summary, positive associations between age and levels of oxidatively damaged DNA appeared mediated by age-related increases in metabolic risk factors.

Adipose Tissue: Sanctuary for HIV/SIV Persistence and Replication

This commentary highlights new findings from a recent study identifying adipose tissue as a potential HIV reservoir and a major site of inflammation during chronic human/simian immunodeficiency virus (HIV/SIV) infection. A concise discussion about upcoming challenges and new research avenues for reducing chronic adipose inflammation during HIV/SIV infection is presented.

Anti-inflammatory γ- and δ-tocotrienols improve cardiovascular, liver and metabolic function in diet-induced obese rats

PURPOSE

This study tested the hypothesis that γ- and δ-tocotrienols are more effective than α-tocotrienol and α-tocopherol in attenuating the signs of diet-induced metabolic syndrome in rats.

METHODS

Five groups of rats were fed a corn starch-rich (C) diet containing 68 % carbohydrates as polysaccharides, while the other five groups were fed a diet (H) high in simple carbohydrates (fructose and sucrose in food, 25 % fructose in drinking water, total 68 %) and fats (beef tallow, total 24 %) for 16 weeks. Separate groups from each diet were supplemented with either α-, γ-, δ-tocotrienol or α-tocopherol (85 mg/kg/day) for the final 8 of the 16 weeks.

RESULTS

H rats developed visceral obesity, hypertension, insulin resistance, cardiovascular remodelling and fatty liver. α-Tocopherol, α-, γ- and δ-tocotrienols reduced collagen deposition and inflammatory cell infiltration in the heart. Only γ- and δ-tocotrienols improved cardiovascular function and normalised systolic blood pressure compared to H rats. Further, δ-tocotrienol improved glucose tolerance, insulin sensitivity, lipid profile and abdominal adiposity. In the liver, these interventions reduced lipid accumulation, inflammatory infiltrates and plasma liver enzyme activities. Tocotrienols were measured in heart, liver and adipose tissue showing that chronic oral dosage delivered tocotrienols to these organs despite low or no detection of tocotrienols in plasma.

CONCLUSION

In rats, δ-tocotrienol improved inflammation, heart structure and function, and liver structure and function, while γ-tocotrienol produced more modest improvements, with minimal changes with α-tocotrienol and α-tocopherol. The most important mechanism of action is likely to be reduction in organ inflammation.

RETRACTED: pNaKtide inhibits Na/K-ATPase reactive oxygen species amplification and attenuates adipogenesis

Obesity has become a worldwide epidemic and is a major risk factor for metabolic syndrome. Oxidative stress is known to play a role in the generation and maintenance of an obesity phenotype in both isolated adipocytes and intact animals. Because we had identified that the Na/K-ATPase can amplify oxidant signaling, we speculated that a peptide designed to inhibit this pathway, pNaKtide, might ameliorate an obesity phenotype. To test this hypothesis, we first performed studies in isolated murine preadipocytes (3T3L1 cells) and found that pNaKtide attenuated oxidant stress and lipid accumulation in a dose-dependent manner. Complementary experiments in C57Bl6 mice fed a high-fat diet corroborated our in vitro observations. Administration of pNaKtide in these mice reduced body weight gain, restored systemic redox and inflammatory milieu, and, crucially, improved insulin sensitivity. Thus, we propose that inhibition of Na/K-ATPase amplification of oxidative stress may ultimately be a novel way to combat obesity, insulin resistance, and metabolic syndrome.

Rice Bran Protein Hydrolysates Improve Insulin Resistance and Decrease Pro-inflammatory Cytokine Gene Expression in Rats Fed a High Carbohydrate-High Fat Diet

A high carbohydrate-high fat (HCHF) diet causes insulin resistance (IR) and metabolic syndrome (MS). Rice bran has been demonstrated to have anti-dyslipidemic and anti-atherogenic properties in an obese mouse model. In the present study, we investigated the beneficial effects of rice bran protein hydrolysates (RBP) in HCHF-induced MS rats. After 12 weeks on this diet, the HCHF-fed group was divided into four subgroups, which were orally administered RBP 100 or 500 mg/kg, pioglitazone 10 mg/kg, or tap water for a further 6 weeks. Compared with normal diet control group, the MS rats had elevated levels of blood glucose, lipid, insulin, and HOMA-IR. Treatment with RBP significantly alleviated all those changes and restored insulin sensitivity. Additionally, RBP treatment increased adiponectin and suppressed leptin levels. Expression of Ppar-γ mRNA in adipose tissues was significantly increased whereas expression of lipogenic genes Srebf1 and Fasn was significantly decreased. Levels of mRNA of proinflammatory cytokines, Il-6, Tnf-α, Nos-2 and Mcp-1 were significantly decreased. In conclusion, the present findings support the consumption of RBP as a functional food to improve insulin resistance and to prevent the development of metabolic syndrome.

Analysis of the Pro- and Anti-Inflammatory Cytokines Secreted by Adult Stem Cells during Differentiation

Adipose-derived stromal/stem cells (ASCs) are adult stem cells that have the potential to differentiate into mesenchymal lineage cells. The abundance of ASCs in adipose tissue and easy accessibility with relatively little donor site morbidity make them attractive candidate cells for tissue engineering and regenerative medicine. However, the underlying inflammatory process that occurs during ASC differentiation into adipocytes and osteoblast has not been extensively investigated. ASCs cultured in osteogenic and adipogenic differentiation medium were characterized by oil red o staining and alizarin red staining, respectively. ASCs undergoing osteogenic and adipogenic differentiation were isolated on days 7, 14, and 21 and assessed by qRT-PCR for the expression of pro- and anti-inflammatory cytokines. ASCs undergoing osteogenic differentiation expressed a distinct panel of cytokines that differed from the cytokine profile of ASCs undergoing adipogenic differentiation at each of the time points analyzed. Mapping the cytokine expression profile during ASC differentiation will provide insight into the role of inflammation in this process and identify potential targets that may aid in enhancing osteogenic or adipogenic differentiation for the purposes of tissue engineering and regenerative medicine.

Nutrient and immune sensing are obligate pathways in metabolism, immunity, and disease

The growth and survival of multicellular organisms depend upon their abilities to acquire and metabolize nutrients, efficiently store and harness energy, and sense and fight infection. Systems for sensing and using nutrients have consequently coevolved alongside systems for sensing and responding to danger signals, including pathogens, and share many of the same cell signaling proteins and networks. Diets rich in carbohydrates and fats can overload these systems, leading to obesity, metabolic dysfunction, impaired immunity, and cardiovascular disease. Excessive nutrient intake promotes adiposity, typically altering adipocyte function and immune cell distribution, both of which trigger metabolic dysfunction. Here, we discuss novel mechanistic links between metabolism and immunity that underlie metabolic dysfunction in obesity. We aim to stimulate debate about how the endocrine and immune systems are connected through autocrine, paracrine, and neuroendocrine signaling in sophisticated networks that are only now beginning to be resolved. Understanding the expression and action of signaling proteins, together with modulating their receptors or pattern recognition using agonists or antagonists, will enable rational intervention in immunometabolism that may lead to novel treatments for obesity and metabolic dysfunction.

Bisphenol A effects on gene expression in adipocytes from children: association with metabolic disorders

Bisphenol A (BPA) is a xenobiotic endocrine-disrupting chemical. In vitro and in vivo studies have indicated that BPA alters endocrine-metabolic pathways in adipose tissue, which increases the risk of metabolic disorders and obesity. BPA can affect adipose tissue and increase fat cell numbers or sizes by regulating the expression of the genes that are directly involved in metabolic homeostasis and obesity. Several studies performed in animal models have accounted for an obesogen role of BPA, but its effects on human adipocytes - especially in children - have been poorly investigated. The aim of this study is to understand the molecular mechanisms by which environmentally relevant doses of BPA can interfere with the canonical endocrine function that regulates metabolism in mature human adipocytes from prepubertal, non-obese children. BPA can act as an estrogen agonist or antagonist depending on the physiological context. To identify the molecular signatures associated with metabolism, transcriptional modifications of mature adipocytes from prepubertal children exposed to estrogen were evaluated by means of microarray analysis. The analysis of deregulated genes associated with metabolic disorders allowed us to identify a small group of genes that are expressed in an opposite manner from that of adipocytes treated with BPA. In particular, we found that BPA increases the expression of pro-inflammatory cytokines and the expression of FABP4 and CD36, two genes involved in lipid metabolism. In addition, BPA decreases the expression of PCSK1, a gene involved in insulin production. These results indicate that exposure to BPA may be an important risk factor for developing metabolic disorders that are involved in childhood metabolism dysregulation.

Influence of body mass index on outcomes after major resection for cancer

BACKGROUND

Evidence supporting worse outcomes among obese patients is inconsistent. This study examined associations between body mass index (BMI) and outcomes after major resection for cancer.

METHODS

Data from the 2005-2012 ACS-NSQIP were used to identify cancer patients (≥18 years) undergoing 1 of 6 major resections: lung surgery, esophagectomy, hepatectomy, gastrectomy, colectomy, or pancreatectomy. We used crude and multivariable regression to compare differences in 30-day mortality, serious and overall morbidity, duration of stay, and operative time among 3 BMI cohorts defined by the World Health Organization: normal versus underweight, overweight-obese I, and obese II-III. Propensity-scored secondary assessment and resection type-specific stratified analyses corroborated results.

RESULTS

A total of 529,955 patients met inclusion criteria; 32.06% had normal BMI, 3.45% were underweight, 32.52% overweight, and 17.76%, 7.51%, and 4.94% obese I-III, respectively. Risk-adjusted outcomes for underweight patients consistently were worse. Overweight-obese I fared similarly to patients with normal BMI but had greater odds of isolated complications. Obese II-III patients experienced only marginally increased odds of morbidity. Analyses among propensity-scored cohorts and stratified by cancer-resection type reported similar trends. Worse outcomes were observed among morbidly obese hepatectomy and pancreatectomy patients.

CONCLUSION

Evidence-based assessment of outcomes after major resection for cancer suggests that obese patients should be treated with the aim for optimal oncologic standards without being hindered by a misleading perception of prohibitively increased perioperative risk. Underweight and certain types of morbidly obese patients require targeted provision of appropriate care.

Relation between leukocyte count, adiposity, and cardiorespiratory fitness in pubertal adolescents

Objective

To compare the total and differential leukocyte count in obese and normal-weight adolescents, and to verify their possible relations with cardiorespiratory fitness and adiposity indicators.

Methods

A cross-sectional study conducted with 139 adolescents (107 obese and 32 normal weight) aged between 13 and 18 years. Cardiorespiratory fitness was determined by direct gas analysis during an incremental treadmill test. Total leukocytes and subsets were estimated by flow cytometry. Body composition was assessed by dual-energy X-ray absorptiometry. The t-test for independent samples was used for comparison between groups. The relation between leukocytes, cardiorespiratory fitness and adiposity indicators was verified by Pearson’s correlation and multiple linear regression (adjusted for age and body mass index) tests.

Results

Obese adolescents had higher leukocyte (8.12±2.36u/L x 10³; p=0.001), neutrophil (4.33±1.86u/L x 10³; p=0.002), and monocyte (0.70±0.22u/L x 10³; p=0.002) counts compared to the levels of normal weight subjects. After the necessary adjustments, cardiorespiratory fitness had a negative association with leukocytes, neutrophils, and monocytes in boys.

Conclusion

Obese adolescents had higher total and differential leucocyte count when compared to normal weight individuals. We also observed a weak positive association between adiposity and total leukocyte, monocyte, and neutrophil counts, and in boys, a negative association between cardiorespiratory fitness and total count of leukocytes, monocytes, and neutrophils.

A multicomponent nutrient bar promotes weight loss and improves dyslipidemia and insulin resistance in the overweight/obese: chronic inflammation blunts these improvements

This study determined if twice-daily consumption of a nutrient-dense bar intended to fill gaps in Western diets, without other dietary/lifestyle requirements, favorably shifted metabolic/anthropometric indicators of dysregulation in a healthy direction. Three 8-wk clinical trials in 43 healthy lean and overweight/obese (OW/OB) adults, who served as their own controls, were pooled for analysis. In less inflamed OW/OB [high-sensitivity C-reactive protein (hsCRP) <1.5], statistically significant decreases occurred in weight (-1.1 ± 0.5 kg), waist circumference (-3.1 ± 1.4 cm), diastolic blood pressure (-4.1 ± 1.6 mmHg), heart rate [HR; -4.0 ± 1.7 beats per minute (bpm)], triglycerides (-72 ± 38.2 mg/dl), insulin resistance (homeostatic model of insulin resistance) (-0.72 ± 0.3), and insulin (-2.8 ± 1.3 mU/L); an increase in HDL-2b (+303 ± 116 nM) and realignment of LDL lipid subfractions toward a less atherogenic profile [decreased small LDL IIIb (-44 ± 23.5 nM), LDL IIIa (-99 ± 43.7 nM), and increased large LDL I (+66 ± 28.0 nM)]. In the more inflamed OW/OB (hsCRP >1.5), inflammation was reduced at 2 wk (-0.66 mg/L), and HR at 8 wk (-3.4 ± 1.3 bpm). The large HDL subfraction (10.5-14.5 nm) increased at 8 wk (+346 ± 126 nM). Metabolic improvements were also observed in lean participants. Thus, favorable changes in measures of cardiovascular health, insulin resistance, inflammation, and obesity were initiated within 8 wk in the OW/OB by replacing deficiencies in Western diets without requiring other dietary or lifestyle modifications; chronic inflammation blunted most improvements.

Mechanisms of enhanced insulin secretion and sensitivity with n-3 unsaturated fatty acids

The widespread acceptance that increased dietary n-3 polyunsaturated fatty acids (PUFAs), especially α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), improve health is based on extensive studies in animals, isolated cells and humans. Visceral adiposity is part of the metabolic syndrome, together with insulin resistance, dyslipidemia, hypertension and inflammation. Alleviation of metabolic syndrome requires normalization of insulin release and responses. This review assesses our current knowledge of the mechanisms that allow n-3 PUFAs to improve insulin secretion and sensitivity. EPA has been more extensively studied than either ALA or DHA. The complex actions of EPA include increased G-protein-receptor-mediated release of glucagon-like peptide 1 (GLP-1) from enteroendocrine L-cells in the intestine, up-regulation of the apelin pathway and down-regulation of other control pathways to promote insulin secretion by the pancreatic β-cells, together with suppression of inflammatory responses to adipokines, inhibition of peroxisome proliferator-activated receptor α actions and prevention of decreased insulin-like growth factor-1 secretion to improve peripheral insulin responses. The receptors involved and the mechanisms of action probably differ for ALA and DHA, with antiobesity effects predominating for ALA and anti-inflammatory effects for DHA. Modifying both GLP-1 release and the actions of adipokines by n-3 PUFAs could lead to additive improvements in both insulin secretion and sensitivity.

A platelet-activating factor (PAF) receptor deficiency exacerbates diet-induced obesity but PAF/PAF receptor signaling does not contribute to the development of obesity-induced chronic inflammation

Platelet-activating factor (PAF) is a well-known phospholipid that mediates acute inflammatory responses. In the present study, we investigated whether PAF/PAF receptor signaling contributed to chronic inflammation in the white adipose tissue (WAT) of PAF receptor-knockout (PAFR-KO) mice. Body and epididymal WAT weights were higher in PAFR-KO mice fed a high-fat diet (HFD) than in wild-type (WT) mice. TNF-α mRNA expression levels in epididymal WAT and the infiltration of CD11c-positive macrophages into epididymal WAT, which led to chronic inflammation, were also elevated in HFD-fed PAFR-KO mice. HFD-fed PAFR-KO mice had higher levels of fasting serum glucose than HFD-fed WT mice as well as impaired glucose tolerance. Although PAF receptor signaling up-regulated the expression of TNF-α and lipopolysaccharide induced the expression of acyl-CoA:lysophosphatidylcholine acyltransferase 2 (LPCAT2) mRNA in bone marrow-derived macrophages, no significant differences were observed in the expression of LPCAT2 mRNA and PAF levels in epididymal WAT between HFD-fed mice and normal diet-fed mice. In addition to our previous finding in which energy expenditure in PAF receptor (PAFR)-deficient mice was low due to impaired brown adipose tissue function, the present study demonstrated that PAF/PAF receptor signaling up-regulated the expression of Ucp1 mRNA, which is essential for cellular thermogenesis, in 3T3-L1 adipocytes. We concluded that the marked accumulation of abdominal fat due to HFD feeding led to more severe chronic inflammation in WAT, which is associated with glucose metabolism disorders, in PAFR-KO mice than in WT mice, and PAF/PAF receptor signaling may regulate energy expenditure and adiposity.

Hypothalamic inflammation and the central nervous system control of energy homeostasis

The control of energy homeostasis relies on robust neuronal circuits that regulate food intake and energy expenditure. Although the physiology of these circuits is well understood, the molecular and cellular response of this program to chronic diseases is still largely unclear. Hypothalamic inflammation has emerged as a major driver of energy homeostasis dysfunction in both obesity and anorexia. Importantly, this inflammation disrupts the action of metabolic signals promoting anabolism or supporting catabolism. In this review, we address the evidence that favors hypothalamic inflammation as a factor that resets energy homeostasis in pathological states.

Estrogen signaling in metabolic inflammation

There is extensive evidence supporting the interference of inflammatory activation with metabolism. Obesity, mainly visceral obesity, is associated with a low-grade inflammatory state, triggered by metabolic surplus where specialized metabolic cells such as adipocytes activate cellular stress initiating and sustaining the inflammatory program. The increasing prevalence of obesity, resulting in increased cardiometabolic risk and precipitating illness such as cardiovascular disease, type 2 diabetes, fatty liver, cirrhosis, and certain types of cancer, constitutes a good example of this association. The metabolic actions of estrogens have been studied extensively and there is also accumulating evidence that estrogens influence immune processes. However, the connection between these two fields of estrogen actions has been underacknowledged since little attention has been drawn towards the possible action of estrogens on the modulation of metabolism through their anti-inflammatory properties. In the present paper, we summarize knowledge on the modification inflammatory processes by estrogens with impact on metabolism and highlight major research questions on the field. Understanding the regulation of metabolic inflammation by estrogens may provide the basis for the development of therapeutic strategies to the management of metabolic dysfunctions.

15-LOX metabolites and angiogenesis: angiostatic effect of 15(S)-HPETE involves induction of apoptosis in adipose endothelial cells

Inflammation is critical in the dysregulated growth of adipose tissue and associated vascular dysfunctions. 15-Lipoxygenase metabolites, important mediators of inflammation in adipose tissue during obese conditions, may contribute to codependence of inflammation and angiogenesis in adipose tissue. We have already reported the pro-angiogenic effect of 15(S)-HETE in adipose tissue. The present study was designed to understand the effect of 15(S)-HPETE, precursor of 15(S)-HETE, on angiogenesis in adipose tissue. Results showed that 15(S)-HPETE exerts an anti-angiogenic effect in adipose tissue. This was evidenced from decreased endothelial sprouting in adipose tissue explants, inhibition of angiogenic phenotype in adipose endothelial cells, decreased production of CD31 and VEGF in endothelial cells treated with 15(S)-HPETE. Further studies to examine the molecular mechanism of anti-angiogenic effect of 15(S)-HPETE showed that it inhibited cell survival signaling molecule Akt and anti-apoptotic Bcl-2 and also activated caspase-3 in adipose endothelial cells. These observations indicate that 15(S)-HPETE exerts its angiostatic effect in adipose tissue by inducing apoptosis of endothelial cells.

Mammalian lipoxygenases and their biological relevance

Lipoxygenases (LOXs) form a heterogeneous class of lipid peroxidizing enzymes, which have been implicated not only in cell proliferation and differentiation but also in the pathogenesis of various diseases with major public health relevance. As other fatty acid dioxygenases LOXs oxidize polyunsaturated fatty acids to their corresponding hydroperoxy derivatives, which are further transformed to bioactive lipid mediators (eicosanoids and related substances). On the other hand, lipoxygenases are key players in the regulation of the cellular redox homeostasis, which is an important element in gene expression regulation. Although the first mammalian lipoxygenases were discovered 40 years ago and although the enzymes have been well characterized with respect to their structural and functional properties the biological roles of the different lipoxygenase isoforms are not completely understood. This review is aimed at summarizing the current knowledge on the physiological roles of different mammalian LOX-isoforms and their patho-physiological function in inflammatory, metabolic, hyperproliferative, neurodegenerative and infectious disorders. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".

Lipid signaling in adipose tissue: Connecting inflammation & metabolism

Obesity-associated low-grade inflammation of white adipose tissue (WAT) contributes to development of insulin resistance and other disorders. Accumulation of immune cells, especially macrophages, and macrophage polarization from M2 to M1 state, affect intrinsic WAT signaling, namely anti-inflammatory and proinflammatory cytokines, fatty acids (FA), and lipid mediators derived from both n-6 and n-3 long-chain PUFA such as (i) arachidonic acid (AA)-derived eicosanoids and endocannabinoids, and (ii) specialized pro-resolving lipid mediators including resolvins derived from both eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), lipoxins (AA metabolites), protectins and maresins (DHA metabolites). In this respect, potential differences in modulating adipocyte metabolism by various lipid mediators formed by inflammatory M1 macrophages typical of obese state, and non-inflammatory M2 macrophages typical of lean state remain to be established. Studies in mice suggest that (i) transient accumulation of M2 macrophages could be essential for the control of tissue FA levels during activation of lipolysis, (ii) currently unidentified M2 macrophage-borne signaling molecule(s) could inhibit lipolysis and re-esterification of lipolyzed FA back to triacylglycerols (TAG/FA cycle), and (iii) the egress of M2 macrophages from rebuilt WAT and removal of the negative feedback regulation could allow for a full unmasking of metabolic activities of adipocytes. Thus, M2 macrophages could support remodeling of WAT to a tissue containing metabolically flexible adipocytes endowed with a high capacity of both TAG/FA cycling and oxidative phosphorylation. This situation could be exemplified by a combined intervention using mild calorie restriction and dietary supplementation with EPA/DHA, which enhances the formation of "healthy" adipocytes. This article is part of a Special Issue entitled Oxygenated metabolism of PUFA: analysis and biological relevance."

Unraveling the complex relationship triad between lipids, obesity, and inflammation

Obesity today stands at the intersection between inflammation and metabolic disorders causing an aberration of immune activity, and resulting in increased risk for diabetes, atherosclerosis, fatty liver, and pulmonary inflammation to name a few. Increases in mortality and morbidity in obesity related inflammation have initiated studies to explore different lipid mediated molecular pathways of attempting resolution that uncover newer therapeutic opportunities of anti-inflammatory components. Majorly the thromboxanes, prostaglandins, leukotrienes, lipoxins, and so forth form the group of lipid mediators influencing inflammation. Of special mention are the omega-6 and omega-3 fatty acids that regulate inflammatory mediators of interest in hepatocytes and adipocytes via the cyclooxygenase and lipoxygenase pathways. They also exhibit profound effects on eicosanoid production. The inflammatory cyclooxygenase pathway arising from arachidonic acid is a critical step in the progression of inflammatory responses. New oxygenated products of omega-3 metabolism, namely, resolvins and protectins, behave as endogenous mediators exhibiting powerful anti-inflammatory and immune-regulatory actions via the peroxisome proliferator-activated receptors (PPARs) and G protein coupled receptors (GPCRs). In this review we attempt to discuss the complex pathways and links between obesity and inflammation particularly in relation to different lipid mediators.

Micronutrients and superoxide dismutase in postmenopausal women with chronic periodontitis: a pilot interventional study

Purpose

The study was aimed at investigating changes in periodontal parameters and superoxide dismutase activity triggered by root surface debridement with and without micronutrient supplementation in postmenopausal women.

Methods

Forty-three postmenopausal chronic periodontitis patients were divided into two groups: group 1 (n=22) were provided periodontal treatment in the form of scaling and root planing (SRP) and group 2 (n=21) patients received SRP along with systemic administration of micronutrient antioxidants. Patients in both groups were subjected to root surface debridement. Group 2 patients also received adjunctive micronutrient antioxidant supplementation. Serum and salivary superoxide dismutase (SOD) activity along with periodontal parameters were recorded at baseline and 3 months after therapy.

Results

Salivary and serum SOD values significantly (P<0.05) improved with periodontal treatment. Improvement in systemic enzymatic antioxidant status along with reduction in gingival inflammation and bleeding on probing (%) sites was significantly greater in group 2 as compared to group 1.

Conclusions

Adjunctive micronutrient supplements reduce periodontal inflammation and improve the status of systemic enzymatic antioxidants in postmenopausal women.

Graphical Abstract

Metabolic health reduces risk of obesity-related cancer in framingham study adults

BACKGROUND

It is unknown whether the risk for obesity-related cancers differs between metabolically unhealthy and healthy overweight/obese adults.

METHODS

Data on body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and random blood glucose in Framingham Heart Study adults (n = 3,763) ages 55 to 69 years were used to estimate risks of obesity-related cancers (n = 385), including postmenopausal breast, female reproductive, colon, liver, gallbladder, pancreas, and kidney cancers, as well as esophageal adenocarcinomas. Multivariable-adjusted Cox proportional hazards models were used to estimate risk for obesity-related cancers associated with body fat and metabolic health (as defined by glucose levels) among subjects in three risk groups (vs. referent group with normal weight/normal glucose): normal weight/elevated glucose, overweight/normal glucose, and overweight/elevated glucose.

RESULTS

Overweight adults [BMI ≥ 25 or WHtR ≥ 0.51 (men) and ≥0.57 (women)] with elevated glucose (≥125 mg/dL) had a statistically significant 2-fold increased risk of developing obesity-related cancer, whereas overweight adults with normal glucose had a 50% increased risk. Normal-weight adults with elevated glucose had no excess cancer risk. The effects of BMI and WHtR were independent of one another. Finally, overweight women with elevated blood glucose had a 2.6-fold increased risk [95% confidence interval (CI), 1.4-4.9] of female reproductive (cervical, endometrial, uterine cancers) and postmenopausal breast cancers, whereas overweight women with normal glucose levels had only a 70% increased risk (95% CI, 1.1-2.5).

CONCLUSION

These results suggest that cancer risk may be lower among metabolically healthy overweight/obese older adults than among overweight/obese adults with metabolic dysfunction.

IMPACT

Metabolic dysfunction and obesity act synergistically to increase cancer risk.

Nitric oxide, oxidant status and antioxidant response in morbidly obese patients: the impact of 1-year surgical weight loss

BACKGROUND

The aims of this study were to evaluate nitric oxide (NO) metabolites (nitrite/nitrate NO x ) as proinflammatory parameter and total oxidant status (TOS) as well as total antioxidant response (TAR) as oxidative stress (OS) markers in morbidly obese (MO) patients in comparison with normal-weight healthy (NWH) subjects and to determine the post-bariatric surgery changes of NO x and OS indicators in relation with weight loss.

METHODS

We examined serum NO x , TOS, and TAR in a bariatric group of MO patients and a NWH control group (n = 23 each group). In the NWH group, serum was examined once, while in the MO group, serum was examined before and at 3, 6, and 12 months after silastic ring vertical gastroplasty (SRVG).

RESULTS

Serum NO x and TOS values were higher (p < 0.001), while TAR level was lower (p < 0.001) in MO patients as compared to the NWH group. No significant changes occurred at 12 months after surgery in the MO group as far as the NO x (p = 0.93), TOS (p = 0.11), and TAR (p = 0.15) levels were concerned as compared to baseline values. However, NO x increased at 6 months after surgery (p < 0.008) and then decreased by the 12th month after SRVG (p < 0.008), reaching almost baseline values.

CONCLUSIONS

At baseline, there was a high production of proinflammatory and OS markers in MO patients. SRVG surgical weight loss was not accompanied by significant changes of these parameters at 1 year after surgery.

Lipidomics reveals a link between CYP1B1 and SCD1 in promoting obesity

Cytochrome P450 1B1 (CYP1B1) is involved in the metabolism of xenobiotic compounds and endogenous metabolites. Disruption of Cyp1b1 in mice results in suppression of high-fat diet (HFD)-induced obesity and an extensive change in hepatic energy regulation despite minimal constitutive expression of CYP1B1 in hepatocytes. Lack of CYP1B1 is correlated with altered lipid metabolism, especially lysophosphatidylcholines, contributing to protection against obesity. Ultraperformance liquid chromatography coupled to electrospray ionization quadrupole mass spectrometry (UPLC-ESI-QTOFMS)-based metabolomics revealed lysophosphatidylcholine 18:0 (LPC 18:0) as a biomarker positively related to HFD-induced obesity. The increased serum LPC 18:0 in wild-type mice is reduced in Cyp1b1-null mice on a HFD, which is reversed in CYP1B1-humanized mice. CYP1B1-humanized mice show higher diet-induced obesity compared with Cyp1b1-null mice, suggesting that human CYP1B1 shows a similar response to HFD as mouse Cyp1b1. In addition, hepatic stearoyl-CoA desaturase 1 (SCD1) expression was decreased in Cyp1b1-null mice, and the attenuated diet-induced obesity and lower serum LPC 18:0 in the Cyp1b1-null mice is elevated after SCD1 overexpression, suggesting that SCD1 is correlated with CYP1B1-induced obesity. These studies establish a biochemical link between cytochromes P450, lipids, and metabolic disorders and suggest that inhibition of CYP1B1 could be target for antiobesity drugs.

PPARδ binding to heme oxygenase 1 promoter prevents angiotensin II-induced adipocyte dysfunction in Goldblatt hypertensive rats

OBJECTIVE

Renin-angiotensin system (RAS) regulates adipogenic response with adipocyte hypertrophy by increasing oxidative stress. Recent studies have shown the role of peroxisome proliferator-activated receptor-δ (PPARδ) agonist in attenuation of angiotensin II-induced oxidative stress. The aim of this study was to explore a potential mechanistic link between PPARδ and the cytoprotective enzyme heme oxygenase-1 (HO-1) and to elucidate the contribution of HO-1 to the adipocyte regulatory effects of PPARδ agonism in an animal model of enhanced RAS, the Goldblatt 2 kidney 1 clip (2K1C) model.

METHOD

We first established a direct stimulatory effect of the PPARδ agonist (GW 501516) on the HO-1 gene by demonstrating increased luciferase activity in COS-7 cells transfected with a luciferase-HO-1 promoter construct. Sprague-Dawley rats were divided into four groups: sham-operated animals, 2K1C rats and 2K1C rats treated with GW 501516, in the absence or presence of the HO activity inhibitor, stannous mesoporphyrin (SnMP).

RESULTS

2K1C animals had increased visceral adiposity, adipocyte hypertrophy, increased inflammatory cytokines, increased circulatory and adipose tisssue levels of renin and Ang II along with increased adipose tissue gp91 phox expression (P<0.05) when compared with sham-operated animals. Treatment with GW 501516 increased adipose tissue HO-1 and adiponectin levels (P<0.01) along with enhancement of Wnt10b and β-catenin expression. HO-1 induction was accompanied by the decreased expression of Wnt5b, mesoderm specific transcript (mest) and C/EBPα levels and an increased number of small adipocytes (P<0.05). These effects of GW501516 were reversed in 2K1C animals exposed to SnMP (P<0.05).

CONCLUSION

Taken together, our study demonstrates, for the first time, that increased levels of Ang II contribute towards adipose tissue dysregulation, which is abated by PPARδ-mediated upregulation of the heme-HO system. These findings highlight the pivotal role and symbiotic relationship of HO-1, adiponectin and PPARδ in the regulation of metabolic homeostasis in adipose tissues.

Implication of the Tpl2 kinase in inflammatory changes and insulin resistance induced by the interaction between adipocytes and macrophages

Adipose tissue inflammation is associated with the development of insulin resistance. In obese adipose tissue, lipopolysaccharides (LPSs) and saturated fatty acids trigger inflammatory factors that mediate a paracrine loop between adipocytes and macrophages. However, the inflammatory signaling proteins underlying this cross talk remain to be identified. The mitogen-activated protein kinase kinase kinase tumor progression locus 2 (Tpl2) is activated by inflammatory stimuli, including LPS, and its expression is up-regulated in obese adipose tissue, but its role in the interaction between adipocytes and macrophages remains ill-defined. To assess the implication of Tpl2 in the cross talk between these 2 cell types, we used coculture system and conditioned medium (CM) from macrophages. Pharmacological inhibition of Tpl2 in the coculture markedly reduced lipolysis and cytokine production and prevented the decrease in adipocyte insulin signaling. Tpl2 knockdown in cocultured adipocytes reduced lipolysis but had a weak effect on cytokine production and did not prevent the alteration of insulin signaling. By contrast, Tpl2 silencing in cocultured macrophages resulted in a marked inhibition of cytokine production and prevented the alteration of adipocyte insulin signaling. Further, when Tpl2 was inhibited in LPS-activated macrophages, the produced CM did not alter adipocyte insulin signaling and did not induce an inflammatory response in adipocytes. By contrast, Tpl2 silencing in adipocytes did not prevent the deleterious effects of a CM from LPS-activated macrophages. Together, these data establish that Tpl2, mainly in macrophages, is involved in the cross talk between adipocytes and macrophages that promotes inflammatory changes and alteration of insulin signaling in adipocytes.

Modulation of obesity-induced inflammation by dietary fats: mechanisms and clinical evidence

Obesity plays a pivotal role in the development of low-grade inflammation. Dietary fatty acids are important modulators of inflammatory responses. Saturated fatty acids (SFA) and n-6 polyunsaturated fatty acids (PUFA) have been reported to exert pro-inflammatory effects. n-3 PUFA in particular, possess anti-inflammatory properties. Numerous clinical studies have been conducted over decades to investigate the impact of dietary fatty acids on inflammatory response in obese individuals, however the findings remained uncertain. High fat meals have been reported to increase pro-inflammatory responses, however there is limited evidence to support the role of individual dietary fatty acids in a postprandial state. Evidence in chronic studies is contradictory, the effects of individual dietary fatty acids deserves further attention. Weight loss rather than n-3 PUFA supplementation may play a more prominent role in alleviating low grade inflammation. In this context, the present review provides an update on the mechanistic insight and the influence of dietary fats on low grade inflammation, based on clinical evidence from acute and chronic clinical studies in obese and overweight individuals.

Dietary cocoa reduces metabolic endotoxemia and adipose tissue inflammation in high-fat fed mice

In diet-induced obesity, adipose tissue (AT) is in a chronic state of inflammation predisposing the development of metabolic syndrome. Cocoa (Theobroma cacao) is a polyphenol-rich food with putative anti-inflammatory activities. Here, we examined the impact and underlying mechanisms of action of cocoa on AT inflammation in high fat-fed mice. In the present study, male C57BL/6 J mice were fed a high fat diet (HF), a HF diet with 8% (w/w) unsweetened cocoa powder (HFC), or a low-fat diet (LF) for 18 weeks. Cocoa supplementation decreased AT mRNA levels of tumor necrosis factor-α, interleukin-6, inducible nitric oxide synthase, and EGF-like module-containing mucin-like hormone receptor-like 1 by 40-60% compared to HF group, and this was accompanied by decreased nuclear protein levels of nuclear factor-κB. Cocoa treatment reduced the levels of arachidonic acid in the AT by 33% compared to HF controls. Moreover, cocoa treatment also reduced protein levels of the eicosanoid-generating enzymes, adipose-specific phospholipase A2 and cyclooxygenase-2 by 53% and 55%, respectively, compared to HF-fed mice. Finally, cocoa treatment ameliorated metabolic endotoxemia (40% reduction in plasma endotoxin) and improved gut barrier function (as measured by increased plasma levels of glucagon-like peptide-2). In conclusion, the present study has shown for the first time that long-term cocoa supplementation can reduce AT inflammation in part by modulating eicosanoid metabolism and metabolic endotoxemia.

The Kaposi's sarcoma-associated herpesvirus (KSHV)-induced 5-lipoxygenase-leukotriene B4 cascade plays key roles in KSHV latency, monocyte recruitment, and lipogenesis

Kaposi's sarcoma-associated herpesvirus (KSHV) is etiologically associated with Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). KS lesions are characterized by endothelial cells with multiple copies of the latent KSHV episomal genome, lytic replication in a low percentage of infiltrating monocytes, and inflammatory cytokines plus growth factors. We demonstrated that KSHV utilizes inflammatory cyclooxygenase 2/prostaglandin E2 to establish and maintain latency (Sharma-Walia, N., A. G. Paul, V. Bottero, S. Sadagopan, M. V. Veettil, N. Kerur, and B. Chandran, PLoS Pathog 6:e1000777, 2010 [doi:10.1371/journal.ppat.1000777]). Here, we evaluated the role of 5-lipoxygenase (5LO) and its chemotactic metabolite leukotriene B4 (LTB4) in KSHV biology. Abundant staining of 5LO was detected in human KS tissue sections. We observed elevated levels of 5LO and high levels of secretion of LTB4 during primary KSHV infection of endothelial cells and in PEL B cells (BCBL-1 and BC-3 cells). Blocking the 5LO/LTB4 cascade inhibited viral latent ORF73, immunomodulatory K5, viral macrophage inflammatory protein 1 (MIP-1), and viral MIP-2 gene expression, without much effect on lytic switch ORF50, immediate early lytic K8, and viral interferon-regulatory factor 2 gene expression. 5LO inhibition significantly downregulated latent viral Cyclin and latency-associated nuclear antigen 2 levels in PEL cells. 5LO/LTB4 inhibition downregulated TH2-related cytokine secretion, elevated TH1-related cytokine secretion, and reduced human monocyte recruitment, adhesion, and transendothelial migration. 5LO/LTB4 inhibition reduced fatty acid synthase (FASN) promoter activity and its expression. Since FASN, a key enzyme required in lipogenesis, is important in KSHV latency, these findings collectively suggest that 5LO/LTB4 play important roles in KSHV biology and that effective inhibition of the 5LO/LTB4 pathway could potentially be used in treatment to control KS/PEL.

Antiobesity effect of caraway extract on overweight and obese women: a randomized, triple-blind, placebo-controlled clinical trial

Caraway (Carum carvi L.), a potent medicinal plant, is traditionally used for treating obesity. This study investigates the weight-lowering effects of caraway extract (CE) on physically active, overweight and obese women through a randomized, triple-blind, placebo-controlled clinical trial. Seventy overweight and obese, healthy, aerobic-trained, adult females were randomly assigned to two groups (n = 35 per group). Participants received either 30 mL/day of CE or placebo without changing their diet or physical activity. Subjects were examined at baseline and after 90 days for changes in body composition, anthropometric indices, and clinical and paraclinical variables. The treatment group, compared with placebo, showed a significant reduction of weight, body mass index, body fat percentage, and waist-to-hip ratio. No changes were observed in lipid profile, urine-specific gravity, and blood pressure of subjects. The results suggest that a dietary CE with no restriction in food intake, when combined with exercise, is of value in the management of obesity in women wishing to lower their weight, BMI, body fat percentage, and body size, with no clinical side effects. In conclusion, results of this study suggest a possible phytotherapeutic approach for caraway extract in the management of obesity. This trial is registered with NCT01833377.

Neonatal overnutrition in mice exacerbates high-fat diet-induced metabolic perturbations

Neonatal overnutrition results in accelerated development of high-fat diet (HFD)-induced metabolic defects in adulthood. To understand whether the increased susceptibility was associated with aggravated inflammation and dysregulated lipid metabolism, we studied metabolic changes and insulin signaling in a chronic postnatal overnutrition (CPO) mouse model. Male Swiss Webster pups were raised with either three pups per litter to induce CPO or ten pups per litter as control (CTR) and weaned to either low-fat diet (LFD) or HFD. All animals were killed on the postnatal day 150 (P150) except for a subset of mice killed on P15 for the measurement of stomach weight and milk composition. CPO mice exhibited accelerated body weight gain and increased body fat mass prior to weaning and the difference persisted into adulthood under conditions of both LFD and HFD. As adults, insulin signaling was more severely impaired in epididymal white adipose tissue (WAT) from HFD-fed CPO (CPO-HFD) mice. In addition, HFD-induced upregulation of pro-inflammatory cytokines was exaggerated in CPO-HFD mice. Consistent with greater inflammation, CPO-HFD mice showed more severe macrophage infiltration than HFD-fed CTR (CTR-HFD) mice. Furthermore, when compared with CTR-HFD mice, CPO-HFD mice exhibited reduced levels of several lipogenic enzymes in WAT and excess intramyocellular lipid accumulation. These data indicate that neonatal overnutrition accelerates the development of insulin resistance and exacerbates HFD-induced metabolic defects, possibly by worsening HFD-induced inflammatory response and impaired lipid metabolism.

The role of 14,15-dihydroxyeicosatrienoic acid levels in inflammation and its relationship to lipoproteins

BACKGROUND

14,15-Epoxyeicosatrienoic acids (14,15-EETs) generated from arachidonic acid by cytochrome P450 epoxygenases have beneficial effects in certain cardiovascular diseases, and increased 14,15-EET levels protect the cardiovascular system. 14,15-EETs are rapidly hydrolyzed by soluble epoxide hydrolase (sEH) to the corresponding 14,15-dihydroxyeicosatrienoic acids (14,15-DHETs), which are generally less biologically active but more stable metabolite. A functionally relevant polymorphism of the CYP2J2 gene is independently associated with an increased risk of coronary heart disease (CHD), and the major CYP2J2 product is 14,15-EETs. 14,15-DHETs can be considered a relevant marker of CYP2J2 activity. Therefore, the aim of the present study was to evaluate the plasma 14,15-DHET levels to reflect the 14,15-EET levels in an indirectly way in patients with CHD, and to highlight the growing body of evidence that 14,15-EETs also play a role in anti-inflammatory and lipid-regulating effects in patients with CHD. This was achieved by investigating the relationship between 14,15-DHETs and high-sensitivity C-reactive protein (hs-CRP) and blood lipoproteins.

METHODS

Samples of peripheral venous blood were drawn from 60 patients with CHD and 60 healthy controls. A 14,15-DHET enzyme-linked immunosorbent assay kit (14,15-DHET ELISA kit) was used to measure the plasma 14,15-DHET levels. Hs-CRP, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein-cholesterol levels were measured.

RESULTS

14,15-DHET levels (2.53 ± 1.60 ng/mL) were significantly higher in patients with CHD as compared with those of the healthy controls (1.65 ± 1.54 ng/mL, P < 0.05). There was a significant positive correlation between 14,15-DHETs and hs-CRP levels (R = 0.286, P = 0.027). However, there was no significant correlation between 14,15-DHETs and blood lipoproteins (all, P > 0.05).

CONCLUSIONS

Increased plasma 14,15-DHET levels reflect the decreased of 14,15-EET levels in an indirectly way. Indicated that decreased plasma 14,15-EET levels might be involved in the inflammatory reaction process in atherosclerosis.

Stimulation of fibrotic processes by the infrapatellar fat pad in cultured synoviocytes from patients with osteoarthritis: a possible role for prostaglandin f2α

OBJECTIVE

Stiffening of the joint is a feature of knee osteoarthritis (OA) that can be caused by fibrosis of the synovium. The infrapatellar fat pad (IPFP) present in the knee joint produces immune-modulatory and angiogenic factors. The goal of the present study was to investigate whether the IPFP can influence fibrotic processes in synovial fibroblasts, and to determine the role of transforming growth factor β (TGFβ) and prostaglandin F2α (PGF2α ) in these processes.

METHODS

Batches of fat-conditioned medium (FCM) were made by culturing pieces of IPFP obtained from the knees of 13 patients with OA. Human OA fibroblast-like synoviocytes (FLS) (from passage 3) were cultured in FCM with or without inhibitors of TGFβ/activin receptor-like kinase 5 or PGF2α for 4 days. The FLS were analyzed for production of collagen and expression of the gene for procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2; encoding lysyl hydroxylase 2b, an enzyme involved in collagen crosslinking) as well as the genes encoding α-smooth muscle actin and type I collagen α1 chain. In parallel, proliferation and migration of the synoviocytes were analyzed.

RESULTS

Collagen production and PLOD2 gene expression by the FLS were increased 1.8-fold (P < 0.05) and 6.0-fold (P < 0.01), respectively, in the presence of FCM, relative to control cultures without FCM. Moreover, the migration and proliferation of synoviocytes were stimulated by FCM. Collagen production was positively associated with PGF2α levels in the FCM (R = 0.89, P < 0.05), and inhibition of PGF2α levels reduced the extent of FCM-induced collagen production and PLOD2 expression. Inhibition of TGFβ signaling had no effect on the profibrotic changes.

CONCLUSION

These results indicate that the IPFP can contribute to the development of synovial fibrosis in the knee joint by increasing collagen production, PLOD2 expression, cell proliferation, and cell migration. In addition, whereas the findings showed that TGFβ is not involved, the more recently discovered profibrotic factor PGF2α appears to be partially involved in the regulation of profibrotic changes.

ω3-PUFAs exert anti-inflammatory activity in visceral adipocytes from colorectal cancer patients

Objective

The aim of this study was to correlate specific fatty acid profiles of visceral white adipose tissue (WAT) with inflammatory signatures potentially associated with colorectal cancer (CRC).

Methods

Human adipocytes were isolated from biopsies of visceral WAT from 24 subjects subdivided in four groups: normal-weight (BMI 22.0-24.9 Kg/m²) and over-weight/obese (BMI 26.0-40.0 Kg/m²), affected or not by CRC. To define whether obesity and/or CRC affect the inflammatory status of WAT, the activation of the pro-inflammatory STAT3 and the anti-inflammatory PPARγ transcription factors as well as the expression of adiponectin were analyzed by immunoblotting in adipocytes isolated from each group of subjects. Furthermore, to evaluate whether differences in inflammatory WAT environment correlate with specific fatty acid profiles, gas-chromatographic analysis was carried out on WAT collected from all subject categories. Finally, the effect of the ω3 docosahexaenoic acid treatment on the balance between pro- and anti-inflammatory factors in adipocytes was also evaluated.

Results

We provide the first evidence for the existence of a pro-inflammatory environment in WAT of CRC patients, as assessed by the up-regulation of STAT3, and the concomitant decrease of PPARγ and adiponectin with respect to healthy subjects. WAT inflammatory status was independent of obesity degree but correlated with a decreased ω3-/ω6-polyunsaturated fatty acid ratio. These observations suggested that qualitative changes, other than quantitative ones, in WAT fatty acid may influence tissue dysfunctions potentially linked to inflammatory conditions. This hypothesis was further supported by the finding that adipocyte treatment with docosahexaenoic acid restored the equilibrium between STAT3 and PPARγ.

Conclusion

Our results suggest that adipocyte dysfunctions occur in CRC patients creating a pro-inflammatory environment that might influence cancer development. Furthermore, the protective potential of docosahexaenoic acid in re-establishing the equilibrium between pro- and anti-inflammatory factors might represent a useful tool for preventive and therapeutic strategies.

Positive effect of mushrooms substituted for meat on body weight, body composition, and health parameters. A 1-year randomized clinical trial

Reducing energy density (ED) of the diet is an important strategy for controlling obesity. This 1-year, randomized clinical trial examined the effect of substituting mushrooms for red meat ('mushroom diet'), compared to a standard diet ('meat diet'), on weight loss and maintenance among 73 obese adults (64 women, 9 men). The subjects completed anthropometric measurements and 7-day food records four times during a standardized weight loss and maintenance regimen. At the end of the 1-year trial, compared to participants on the standard diet, participants on the mushroom diet (n=36) reported lower intakes of energy (mean ± [SE]=-123 ± 113 kcals) and fat (-4.25 ± 6.88 g), lost more pounds and percentage body weight (-7.03 ± 3.34 lbs, 3.6%), achieved lower body mass index (-1.53 ± 0.36), waist circumference (-2.6 ± 3.5 in.) and percent total body fat (-0.85 ± 0.53), and had lower systolic and diastolic pressure (-7.9 and -2.5 mmHg); their lipid profile and inflammatory markers also improved. After initial weight loss, subjects following the mushroom diet maintained that loss well. Those who completed the full 12-month trial still weighed a mean of 7 lbs less than baseline. Thus, encouraging adults to substitute mushrooms for red meat was a useful strategy for enhancing weight loss, weight maintenance, and health parameters.

Diet-induced obesity, adipose inflammation, and metabolic dysfunction correlating with PAR2 expression are attenuated by PAR2 antagonism

Excessive uptake of fatty acids and glucose by adipose tissue triggers adipocyte dysfunction and infiltration of immune cells. Altered metabolic homeostasis in adipose tissue promotes insulin resistance, type 2 diabetes, hypertension, and cardiovascular disease. Inflammatory and metabolic processes are mediated by certain proteolytic enzymes that share a common cellular target, protease-activated receptor 2 (PAR2). This study showed that human and rat obesity correlated in vivo with increased expression of PAR2 in adipose tissue, primarily in stromal vascular cells (SVCs) including macrophages. PAR2 was expressed more than other PARs on human macrophages and was increased by dietary fatty acids (palmitic, stearic, and myristic). A novel PAR2 antagonist, GB88 (5-isoxazoyl-Cha-Ile-spiroindene-1,4-piperidine), given orally at 10 mg/kg/d (wk 8-16) reduced body weight by ∼10% in obese rats fed a high-carbohydrate high-fat (HCHF) diet for 16 wk, and strongly attenuated adiposity, adipose tissue inflammation, infiltrated macrophages and mast cells, insulin resistance, and cardiac fibrosis and remodeling; while reversing liver and pancreatic dysfunction and normalizing secretion of PAR2-directed glucose-stimulated insulin secretion in MIN6 β cells. In summary, PAR2 is a new biomarker for obesity, and its expression is stimulated by dietary fatty acids; PAR2 is a substantial contributor to inflammatory and metabolic dysfunction; and a PAR2 antagonist inhibits diet-induced obesity and inflammatory, metabolic, and cardiovascular dysfunction.

Oxidative stress and inflammatory markers in relation to circulating levels of adiponectin

OBJECTIVE

Previous epidemiological studies together with animal studies have suggested an association between adiponectin and oxidative stress and inflammation, but community-based studies are lacking. Our objective was to investigate the relative importance of oxidative stress and inflammatory markers, representing different pathways in relation to adiponectin.

DESIGN AND METHODS

In a cross-sectional sample of 929 70-year-old individuals (50% women) of the Prospective Investigation of the Vasculature in Uppsala Seniors study, relations between serum adiponectin and oxidative stress [conjugated dienes (CD), homocysteine, total antioxidant capacity, oxidized low-density lipoprotein (OxLDL), OxLDL antibodies, baseline CD of LDL, glutathione (GSH), total glutathione (TGSH), glutathione disulfide], circulation interleukins (IL-6, IL-8), other cytokines [tumor necrosis factor α, monocyte chemotactic protein-1 (MCP-1), epidermal growth factor (EGF), vascular endothelial growth factor], cell adhesion molecules (vascular cell adhesion molecule-1, intercellular adhesion molecule-1, E-selectin, P-selectin, L-selectin), and systemic inflammatory markers [C-reactive protein (CRP), leukocyte count] in separate models were investigated.

RESULTS

In age- and sex-adjusted, as well as multivariable-adjusted models, adiponectin was significantly and positively associated with GSH, log TGSH, whereas an inverse association was observed for CD and log EGF. An inverse association between adiponectin and MCP-1, log E-selectin, and log CRP was significant in age- and sex-adjusted models, but not in multivariable-adjusted models.

CONCLUSIONS

Our results imply that higher levels of adiponectin are associated with a more beneficial oxidative stress profile, with higher levels of principal anti-oxidative GSH and total GSH together with lower levels of lipid peroxidation, possibly through shared pathways. Further studies are needed to investigate whether changes in the oxidative stress profile may be a mechanism linking adiponectin with type 2 diabetes and/or cardiovascular disease.

Nutritionally mediated oxidative stress and inflammation

There are many sources of nutritionally mediated oxidative stress that trigger inflammatory cascades along short and long time frames. These events are primarily mediated via NF κ B. On the short-term scale postprandial inflammation is characterized by an increase in circulating levels of IL-6 and TNF- α and is mirrored on the long-term by proinflammatory gene expression changes in the adipocytes and peripheral blood mononuclear cells (PBMCs) of obese individuals. Specifically the upregulation of CCL2/MCP-1, CCL3/MIP-1 α , CCL4/MIP-1 β , CXCL2/MIP-2 α , and CXCL3/MIP-2 β is noted because these changes have been observed in both adipocytes and PBMC of obese humans. In comparing numerous human intervention studies it is clear that pro-inflammatory and anti-inflammatory consumption choices mediate gene expression in humans adipocytes and peripheral blood mononuclear cells. Arachidonic acid and saturated fatty acids (SFAs) both demonstrate an ability to increase pro-inflammatory IL-8 along with numerous other inflammatory factors including IL-6, TNF α , IL-1 β , and CXCL1 for arachidonic acid and IGB2 and CTSS for SFA. Antioxidant rich foods including olive oil, fruits, and vegetables all demonstrate an ability to lower levels of IL-6 in PBMCs. Thus, dietary choices play a complex role in the mediation of unavoidable oxidative stress and can serve to exacerbate or dampen the level of inflammation.

Gene expression profiling reveals distinct features of various porcine adipose tissues

Background

The excessive accumulation of body fat is a major risk factor to develop a variety of metabolic diseases. To investigate the systematic association between the differences in gene expression profiling and adipose deposition, we used pig as a model, and measured the gene expression profiling of six variant adipose tissues in male and females from three pig breeds which display distinct fat level.

Results

We identified various differential expressed genes among breeds, tissues and between sexes, and further used a clustering method to identify sets of functionally co-expression genes linked to different obesity-related phenotypes. Our results reveal that the subcutaneous adipose tissues mainly modulate metabolic indicators, nonetheless, the visceral adipose tissues as well as the intermuscular adipose tissue were mainly associated with the impaired inflammatory and immune response.

Conclusions

The present study provided the evidence of gene expression profiling that the subcutaneous adipose tissues are mainly affected the metabolism process, whereas the visceral and intermuscular adipose tissues should been term as the metabolic risk factors of obesity.

C5a receptor deficiency alters energy utilization and fat storage

OBJECTIVE

To investigate the impact of whole body C5a receptor (C5aR) deficiency on energy metabolism and fat storage.

DESIGN

Male wildtype (WT) and C5aR knockout (C5aRKO) mice were fed a low fat (CHOW) or a high fat high sucrose diet-induced obesity (DIO) diet for 14 weeks. Body weight and food intake were measured weekly. Indirect calorimetry, dietary fatload clearance, insulin and glucose tolerance tests were also evaluated. Liver, muscle and adipose tissue mRNA gene expression were measured by RT-PCR.

RESULTS

At week one and 12, C5aRKO mice on DIO had increased oxygen consumption. After 12 weeks, although food intake was comparable, C5aRKO mice had lower body weight (-7% CHOW, -12% DIO) as well as smaller gonadal (-38% CHOW, -36% DIO) and inguinal (-29% CHOW, -30% DIO) fat pads than their WT counterparts. Conversely, in WT mice, C5aR was upregulated in DIO vs CHOW diets in gonadal adipose tissue, muscle and liver, while C5L2 mRNA expression was lower in C5aRKO on both diet. Furthermore, blood analysis showed lower plasma triglyceride and non-esterified fatty acid levels in both C5aRKO groups, with faster postprandial triglyceride clearance after a fatload. Additionally, C5aRKO mice showed lower CD36 expression in gonadal and muscle on both diets, while DGAT1 expression was higher in gonadal (CHOW) and liver (CHOW and DIO) and PPARγ was increased in muscle and liver.

CONCLUSION

These observations point towards a role (either direct or indirect) for C5aR in energy expenditure and fat storage, suggesting a dual role for C5aR in metabolism as well as in immunity.

New players for advanced prostate cancer and the rationalisation of insulin-sensitising medication

Obesity and type 2 diabetes are recognised risk factors for the development of some cancers and, increasingly, predict more aggressive disease, treatment failure, and cancer-specific mortality. Many factors may contribute to this clinical observation. Hyperinsulinaemia, dyslipidaemia, hypoxia, ER stress, and inflammation associated with expanded adipose tissue are thought to be among the main culprits driving malignant growth and cancer advancement. This observation has led to the proposal of the potential utility of "old players" for the treatment of type 2 diabetes and metabolic syndrome as new cancer adjuvant therapeutics. Androgen-regulated pathways drive proliferation, differentiation, and survival of benign and malignant prostate tissue. Androgen deprivation therapy (ADT) exploits this dependence to systemically treat advanced prostate cancer resulting in anticancer response and improvement of cancer symptoms. However, the initial therapeutic response from ADT eventually progresses to castrate resistant prostate cancer (CRPC) which is currently incurable. ADT rapidly induces hyperinsulinaemia which is associated with more rapid treatment failure. We discuss current observations of cancer in the context of obesity, diabetes, and insulin-lowering medication. We provide an update on current treatments for advanced prostate cancer and discuss whether metabolic dysfunction, developed during ADT, provides a unique therapeutic window for rapid translation of insulin-sensitising medication as combination therapy with antiandrogen targeting agents for the management of advanced prostate cancer.

Emerging targets in lipid-based therapy

The use of prostaglandins and NSAIDS in the clinic has proven that lipid mediators and their associated pathways make attractive therapeutic targets. When contemplating therapies involving lipid pathways, several basic agents come to mind. There are the enzymes and accessory proteins that lead to the metabolism of lipid substrates, provided through diet or through actions of lipases, the subsequent lipid products, and finally the lipid sensors or receptors. There is abundant evidence that molecules along this lipid continuum can serve as prognostic and diagnostic indicators and are in fact viable therapeutic targets. Furthermore, lipids themselves can be used as therapeutics. Despite this, the vernacular dialog pertaining to "biomarkers" does not routinely include mention of lipids, though this is rapidly changing. Collectively these agents are becoming more appreciated for their respective roles in diverse disease processes from cancer to preterm labor and are receiving their due appreciation after decades of ground work in the lipid field. By relating examples of disease processes that result from dysfunction along the lipid continuum, as well as examples of lipid therapies and emerging technologies, this review is meant to inspire further reading and discovery.

The inhibitory effect of pterostilbene on inflammatory responses during the interaction of 3T3-L1 adipocytes and RAW 264.7 macrophages

Chronic inflammation is characterized by the upregulation of proinflammatory cytokines in obese adipose tissue. Accumulations of adipose tissue macrophages enhance a chronic inflammatory state in adipose tissues. Many studies have indicated that the adipocyte-related inflammatory response in obesity is characterized by an enhanced infiltration of macrophages. The aim of this work was to study the inhibitory effects of garcinol and pterostilbene on the change in inflammatory response due to the interaction between 3T3-L1 adipocytes and RAW 264.7 macrophages. In the TNF-α-induced 3T3-L1 adipocyte model, garcinol and pterostilbene significantly decreased the mRNA expression of COX-2, iNOS, IL-6, and IL-1β and IL-6 secretion by suppressing phosphorylation of p-IκBα and p-p65. In a coculture model of 3T3-L1 adipocytes and RAW 264.7 macrophages, pterostilbene suppressed IL-6 and TNF-α secretion and proinflammatory mRNA expression and also reduced the migration of macrophages toward adipocytes. In the RAW 264.7 macrophage-derived conditioned medium (RAW-CM)-induced 3T3-L1 adipocyte and 3T3-CM-induced RAW 264.7 macrophage models, pterostilbene significantly decreased IL-6 and TNF-α secretion and proinflammatory mRNA expression (COX-2, iNOS, IL-6, TNF-α, PAI-1, CRP, MCP-1, resistin, and leptin). Our findings suggest that garcinol and pterostilbene may provide novel and useful applications to reduce the chronic inflammatory properties of adipocytes. We also found that pterostilbene inhibits proinflammatory responses during the interaction between 3T3-L1 adipocytes and RAW 264.7 macrophages.