Ovariectomy modifies lipid metabolism of retroperitoneal white fat in rats: a proteomic approach.

Menopause is often accompanied by visceral obesity. With the aim of exploring the consequences of ovarian failure on visceral fat, we evaluated the effects of ovariectomy and estrogen replacement on the proteome/phosphoproteome and on the fatty acid profile of the retroperitoneal adipose depot (RAT) of rats. Eighteen 3-mo-old female Wistar rats were either ovariectomized or sham operated and fed with standard chow for 3 mo. A subgroup of ovariectomized rats received estradiol replacement. RAT samples were analyzed with data-independent acquisitions LC-MS/MS, and pathway analysis was performed with the differentially expressed/phosphorylated proteins. RAT lipid profile was analyzed by gas chromatography. Ovariectomy induced high adiposity and insulin resistance and promoted alterations in protein expression and phosphorylation. Pathway analysis showed that five pathways were significantly affected by ovariectomy, namely, metabolism of lipids (including fatty acid metabolism and mitochondrial fatty acid ß-oxidation), fatty acyl-CoA biosynthesis, innate immune system (including neutrophil degranulation), metabolism of vitamins and cofactors, and integration of energy metabolism (including ChREBP activates metabolic gene expression). Lipid profile analysis showed increased palmitic and palmitoleic acid content. The analysis of the data indicated that ovariectomy favored lipogenesis whereas it impaired fatty acid oxidation and induced a proinflammatory state in the visceral adipose tissue. These effects are consistent with the findings of high adiposity, hyperleptinemia, and impaired insulin sensitivity. The observed alterations were partially attenuated by estradiol replacement. The data point to a role of disrupted lipid metabolism in adipose tissue in the genesis of obesity after menopause.

High-fat diet intake induces depressive-like behavior in ovariectomized rats.

This study tested the effects of ovariectomy, allied or not to high-fat feeding and estradiol replacement, on hormonal, metabolic and behavioral parameters, to explore the connection of obesity and depression after menopause. Wistar rats were either ovariectomized or sham-operated and fed with either standard chow or lard-enriched diet for twelve weeks. Sub-groups of ovariectomized rats received estradiol replacement. Depressive-like behaviors were assessed by the forced swim test and locomotor activity was assessed by the elevated plus maze test. Ovariectomy alone increased body weight gain and feed efficiency and induced hyperleptinemia and glucose intolerance while it increased caloric intake and body adiposity only marginally. High-fat intake alone induced obesity and, in combination with ovariectomy, accentuated the ovariectomy-induced alterations. Estradiol replacement attenuated the hormonal alterations only in chow-fed rats. Ovariectomy combined with high-fat intake induced depressive-like behaviors, which were marginally attenuated by estradiol. Depressive-like behaviors were associated with metabolic and body composition parameters and with estrogen status. The data indicate that the vulnerability to develop depression after menopause is influenced by high-fat intake. It is suggested that weight management is a crucial issue in postmenopausal women, probably having a beneficial role in preventing the appearance of mental health problems.

A diet including xanthan gum triggers a pro-inflammatory response in Wistar rats inoculated with Walker 256 cells.

OBJECTIVE: The aim of this study was to evaluate the effect of adding xanthan gum to the diet of rats on the production of cytokines and pro-inflammatory factors and on tumor development in rats inoculated with Walker 256 tumor cells. METHODS: Fifty-six rats were divided into 4 groups: control diet (C), control diet with tumor (TC), xanthan gum diet (XG), xanthan gum diet with tumor (TXG). RESULTS: The ingestion of xanthan gum promotes changes in cytokine content: increasing IL-6 TNF-α and IL-10 in retroperitoneal adipose tissue compared to the control group; and increasing TNF-α in the mesenteric adipose tissue compared to the C and TXG groups. On the contrary, the addition of xanthan gum to the diet did not affect the development of Walker 256 tumors in rats. CONCLUSION: The continuous use of xanthan gum triggered a pro-inflammatory response, promoting an increase in pro-inflammatory cytokines in the adipose tissue, but it did not have an effect on the tumor development in the animals inoculated with Walker 256 tumor cells.

A proteomics-metabolomics approach indicates changes in hypothalamic glutamate-GABA metabolism of adult female rats submitted to intrauterine growth restriction.

PURPOSE: Intrauterine growth restriction (IUGR) has been shown to induce the programming of metabolic disturbances and obesity, associated with hypothalamic derangements. The present study aimed at investigating the effects of IUGR on the protein and metabolite profiles of the hypothalamus of adult female rats. METHODS: Wistar rats were mated and either had ad libitum access to food (control group) or received only 50% of the control intake (restricted group) during the whole pregnancy. Both groups ate ad libitum throughout lactation. At 4 months of age, the control and restricted female offspring was euthanized for blood and tissues collection. The hypothalami were processed for data independent acquisition mass spectrometry-based proteomics or targeted mass spectrometry-based metabolomics. RESULTS: The adult females submitted to IUGR showed increased glycemia and body adiposity, with normal body weight and food intake. IUGR modulated significantly 28 hypothalamic proteins and 7 hypothalamic metabolites. The effects of IUGR on hypothalamic proteins and metabolites included downregulation of glutamine synthetase, glutamate decarboxylase, glutamate dehydrogenase, isocitrate dehydrogenase, α-ketoglutarate, and up-regulation of NADH dehydrogenase and phosphoenolpyruvate. Integrated pathway analysis indicated that IUGR affected GABAergic synapse, glutamate metabolism, and TCA cycle, highly interconnected pathways whose derangement has potentially multiple consequences. CONCLUSION: The present findings suggested that the effects of IUGR on GABA/glutamate-glutamine cycle may be involved in the programming of obesity and hyperglycemia in female rats.

Corrigendum: High-Fat Feeding Improves Anxiety-Type Behavior Induced by Ovariectomy in Rats.

[This corrects the article DOI: 10.3389/fnins.2018.00557.].

High-Fat Feeding Improves Anxiety-Type Behavior Induced by Ovariectomy in Rats.

Menopause-induced changes may include increased incidence of both depression/anxiety and obesity. We hypothesized that behavioral changes that may develop after ovarian failure could be related to neurochemical and metabolic aspects affected by this condition and that high-fat intake may influence these associations. The present study investigated in rats the effects of ovariectomy, either alone or combined with high-fat diets enriched with either lard or fish-oil, on metabolic, behavioral and monoaminergic statuses, and on gene expression of neuropeptides and receptors involved in energy balance and mood regulation. Female rats had their ovaries removed and received either standard chow (OvxC) or high-fat diets enriched with either lard (OvxL) or fish-oil (OvxF) for 8 weeks. The Sham group received only chow diet. Ovariectomy increased feed efficiency and body weight gain and impaired glucose homeostasis and serotonin-induced hypophagia, effects either maintained or even accentuated by the lard diet but counteracted by the fish diet. The OvxL group developed obesity and hyperleptinemia. Regarding components of hypothalamic serotonergic system, both ovariectomy alone or combined with the fish diet increased 5-HT2C expression while the lard diet reduced 5-HT1B mRNA. Ovariectomy increased the anxiety index, as derived from the elevated plus maze test, while both high-fat groups showed normalization of this index. In the forced swimming test, ovariectomy allied to high-lard diet, but not to fish-oil diet, reduced the latency to immobility, indicating vulnerability to a depressive-like state. Linear regression analysis showed hippocampal AgRP to be negatively associated with the anxiety index and hypothalamic AgRP to be positively associated with the latency to immobility. These AgRp gene expression associations are indicative of a beneficial involvement of this neuropeptide on both depression and anxiety measures. The present findings demonstrate metabolic, neurochemical and behavioral alterations after ovaries removal and highlight a positive effect of high-fat feeding on the anxiety-like behavior shown by ovariectomized animals. Since the polyunsaturated ômega-3 intake (fish diet), unlike the saturated fat intake (lard diet), failed to induce deleterious metabolic or neurochemical consequences, further studies are needed focusing on the potential of this dietary component as an adjuvant anxiolytic agent after menopause.

Maternal consumption of green tea extract during pregnancy and lactation alters offspring's metabolism in rats.

INTRODUCTION: Green tea extract has anti-inflammatory and antioxidant effects which improve dyslipidemia and decrease adipose tissue depots associated with hyperlipidic diet consumption. OBJECTIVE: To evaluate the effect of green tea extract consumption by rats during pregnancy and lactation on the metabolism of their offspring that received control or high-fat diet with water during 10 weeks after weaning. METHODS: Wistar rats received water (W) or green tea extract diluted in water (G) (400 mg/kg body weight/day), and control diet (10 animals in W and G groups) during pregnancy and lactation. After weaning, offspring received water and a control (CW) or a high-fat diet (HW), for 10 weeks. One week before the end of treatment, oral glucose tolerance test was performed. The animals were euthanized and the samples were collected for biochemical, hormonal and antioxidant enzymes activity analyses. In addition, IL-10, TNF-α, IL-6, and IL-1ß were quantified by ELISA while p-NF-κBp50 was analyzed by Western Blotting. Repeated Measures ANOVA, followed by Tukey's test were used to find differences between data (p < 0.05). RESULTS: The consumption of high-fat diet by rats for 10 weeks after weaning promoted hyperglycemia and hyperinsulinemia, and increased fat depots. The ingestion of a high-fat diet by the offspring of mothers who consumed green tea extract during pregnancy and lactation decreased the inflammatory cytokines in adipose tissue, while the ingestion of a control diet increased the same cytokines. CONCLUSION: Our results demonstrate that prenatal consumption of green tea associated with consumption of high-fat diet by offspring after weaning prevented inflammation. However, maternal consumption of the green tea extract induced a proinflammatory status in the adipose tissue of the adult offspring that received the control diet after weaning.

Lipases and lipid droplet-associated protein expression in subcutaneous white adipose tissue of cachectic patients with cancer.

BACKGROUND: Cancer cachexia is a multifactorial metabolic syndrome characterized by marked loss of adipose tissue and skeletal muscle. Fat loss from adipose tissue in cancer cachexia is partly the result of increased lipolysis. Despite the growing amount of studies focused on elucidating the mechanisms through which lipolysis-related proteins regulate the lipolytic process, there are scarce data concerning that profile in the adipose tissue of cancer cachectic patients. Considering its fundamental importance, it was our main purpose to characterize the expression of the lipolysis-related proteins in the white adipose tissue of cachectic cancer patients. METHODS: Patients from the University Hospital were divided into three groups: control, cancer cachexia (CC), and weight-stable cancer patients (WSC). To gain greater insight into adipose tissue wasting during cancer cachexia progression, we have also analyzed an experimental model of cachexia (Walker 256 carcinosarcoma). Animals were divided into: control, intermediate cachexia (IC) and terminal cachexia (TC). Subcutaneous white adipose tissue of patients and epidydimal white adipose tissue of animals were investigated regarding molecular aspects by determining the protein content and gene expression of hormone-sensitive lipase (HSL), adipose triglyceride lipase (ATGL), comparative gene identification-58 (CGI-58), perilipin 1, leptin, adiponectin, visfatin, and tumour necrosis factor alpha (TNF-alpha). RESULTS: We found augmented lipolysis in CC associated with increased HSL expression, as well as upregulation of ATGL expression and reduction in perilipin 1 content. In IC, there was an imbalance in the secretion of pro- and anti-inflammatory factors. The alterations at the end-stage of cachexia were even more profound, and there was a reduction in the expression of almost all proteins analyzed in the animals. CONCLUSIONS: Our findings show that cachexia induces important morphological, molecular, and humoral alterations in the white adipose tissue, which are specific to the stage of the syndrome.

Intrauterine Growth Restriction Programs the Hypothalamus of Adult Male Rats: Integrated Analysis of Proteomic and Metabolomic Data.

Programming of hypothalamic functions regulating energy homeostasis may play a role in intrauterine growth restriction (IUGR)-induced adulthood obesity. The present study investigated the effects of IUGR on the hypothalamus proteome and metabolome of adult rats submitted to 50% protein-energy restriction throughout pregnancy. Proteomic and metabolomic analyzes were performed by data independent acquisition mass spectrometry and multiple reaction monitoring, respectively. At age 4 months, the restricted rats showed elevated adiposity, increased leptin and signs of insulin resistance. 1356 proteins were identified and 348 quantified while 127 metabolites were quantified. The restricted hypothalamus showed down-regulation of 36 proteins and 5 metabolites and up-regulation of 21 proteins and 9 metabolites. Integrated pathway analysis of the proteomics and metabolomics data indicated impairment of hypothalamic glucose metabolism, increased flux through the hexosamine pathway, deregulation of TCA cycle and the respiratory chain, and alterations in glutathione metabolism. The data suggest IUGR modulation of energy metabolism and redox homeostasis in the hypothalamus of male adult rats. The present results indicated deleterious consequences of IUGR on hypothalamic pathways involved in pivotal physiological functions. These results provide guidance for future mechanistic studies assessing the role of intrauterine malnutrition in the development of metabolic diseases later in life.

Homeostasis Model Assessment-Adiponectin: the role of different types of physical exercise in obese adolescents.

BACKGROUND: Homeostasis Model Assessment-Adiponectin (HOMA-AD) is suggesting a new biomarker of insulin resistance in obese population. In this way, the purpose of this study was to investigate the effects of different kinds of exercise in the sensitive index predictor of insulin resistance. METHODS: A total of 148 obese adolescents were enrolled in the program. They aged 15-19 y, with Body Mass Index (BMI) ≥P95th and were submitted to 1 year of interdisciplinary weight loss therapy, randomized in two groups, aerobic training (AT) (N.=51) and aerobic plus resistance training (N.=97). Blood samples were collected to analyze adiponectin, glucose and insulin concentrations. The insulin resistance was measured by HOMA-AD and Homeostasis Model Assessment Insulin Resistance Index (HOMA-IR). RESULTS: Both kinds of exercise training promoted a decrease in body mass, body mass index, fat mass, visceral and subcutaneous fat. However, only aerobic plus resistance training was effective to reduce HOMA-AD, insulin and glucose concentration; and increase insulin sensibility and adiponectin concentration. CONCLUSIONS: The aerobic plus resistance training was more effective than AT alone to improve the HOMA-AD, suggesting clinical application on obesity, diabetes, atherosclerosis and metabolic syndrome control in the pediatric population.

Chronic psychological stress and high-fat high-fructose diet disrupt metabolic and inflammatory gene networks in the brain, liver, and gut and promote behavioral deficits in mice.

The mechanisms underlying the association between chronic psychological stress, development of metabolic syndrome (MetS), and behavioral impairment in obesity are poorly understood. The aim of the present study was to assess the effects of mild chronic psychological stress on metabolic, inflammatory, and behavioral profiles in a mouse model of diet-induced obesity. We hypothesized that (1) high-fat high-fructose diet (HFHF) and psychological stress would synergize to mediate the impact of inflammation on the central nervous system in the presence of behavioral dysfunction, and that (2) HFHF and stress interactions would impact insulin and lipid metabolism. C57Bl/6 male mice underwent a combination of HFHF and two weeks of chronic psychological stress. MetS-related conditions were assessed using untargeted plasma metabolomics, and structural and immune changes in the gut and liver were evaluated. Inflammation was measured in plasma, liver, gut, and brain. Our results show a complex interplay of diet and stress on gut alterations, energetic homeostasis, lipid metabolism, and plasma insulin levels. Psychological stress and HFHF diet promoted changes in intestinal tight junctions proteins and increases in insulin resistance and plasma cholesterol, and impacted the RNA expression of inflammatory factors in the hippocampus. Stress promoted an adaptive anti-inflammatory profile in the hippocampus that was abolished by diet treatment. HFHF increased hippocampal and hepatic Lcn2 mRNA expression as well as LCN2 plasma levels. Behavioral changes were associated with HFHF and stress. Collectively, these results suggest that diet and stress as pervasive factors exacerbate MetS-related conditions through an inflammatory mechanism that ultimately can impact behavior. This rodent model may prove useful for identification of possible biomarkers and therapeutic targets to treat metabolic syndrome and mood disorders.

Impact of Doxorubicin Treatment on the Physiological Functions of White Adipose Tissue.

White adipose tissue (WAT) plays a fundamental role in maintaining energy balance and important endocrine functions. The loss of WAT modifies adipokine secretion and disrupts homeostasis, potentially leading to severe metabolic effects and a reduced quality of life. Doxorubicin is a chemotherapeutic agent used clinically because of its good effectiveness against various types of cancer. However, doxorubicin has deleterious effects in many healthy tissues, including WAT, liver, and skeletal and cardiac muscles. Our objective was to investigate the effects of doxorubicin on white adipocytes through in vivo and in vitro experiments. Doxorubicin reduced the uptake of glucose by retroperitoneal adipocytes and 3T3-L1 cells via the inhibition of AMP-activated protein kinase Thr172 phosphorylation and glucose transporter 4 content. Doxorubicin also reduced the serum level of adiponectin and, to a greater extent, the expression of genes encoding lipogenic (Fas and Acc) and adipogenic factors (Pparg, C/ebpa, and Srebp1c) in retroperitoneal adipose tissue. In addition, doxorubicin inhibited both lipogenesis and lipolysis and reduced the hormone-sensitive lipase and adipose tissue triacylglycerol lipase protein levels. Therefore, our results demonstrate the impact of doxorubicin on WAT. These results are important to understand some side effects observed in patients receiving chemotherapy and should encourage new adjuvant treatments that aim to inhibit these side effects.

Green Tea Extract Rich in Epigallocatechin-3-Gallate Prevents Fatty Liver by AMPK Activation via LKB1 in Mice Fed a High-Fat Diet.

Supplementation with epigallocatechin-3-gallate has been determined to aid in the prevention of obesity. Decaffeinated green tea extract appears to restore a normal hepatic metabolic profile and attenuate high-fat diet (HFD)-induced effects, thereby preventing non-alcoholic fatty liver disease in mice. Mice were maintained on either a control diet (CD) or HFD for 16 weeks and supplemented with either water or green tea extract (50 mg/kg/day). The body mass increase, serum adiponectin level, and lipid profile were measured over the course of the treatment. Furthermore, the AMPK pathway protein expression in the liver was measured. From the fourth week, the weight gain in the CD + green tea extract (CE) group was lower than that in the CD + water (CW) group. From the eighth week, the weight gain in the HFD + water (HFW) group was found to be higher than that in the CW group. Moreover, the weight gain in the HFD + green tea extract (HFE) group was found to be lower than that in the HFW group. Carcass lipid content was found to be higher in the HFW group than that in the CW and HFE groups. Serum analysis showed reduced non-esterified fatty acid level in the CE and HFE groups as compared with their corresponding placebo groups. Increased adiponectin level was observed in the same groups. Increased VLDL-TG secretion was observed in the HFW group as compared with the CW and HFE groups. Increased protein expression of AdipoR2, SIRT1, pLKB1, and pAMPK was observed in the HFE group, which explained the reduced expression of ACC, FAS, SREBP-1, and ChREBP in this group. These results indicate that the effects of decaffeinated green tea extract may be related to the activation of AMPK via LKB1 in the liver of HFD-fed mice.

Cancer as a Proinflammatory Environment: Metastasis and Cachexia.

The development of the syndrome of cancer cachexia and that of metastasis are related with a poor prognostic for cancer patients. They are considered multifactorial processes associated with a proinflammatory environment, to which tumour microenvironment and other tissues from the tumour bearing individuals contribute. The aim of the present review is to address the role of ghrelin, myostatin, leptin, HIF, IL-6, TNF-α, and ANGPTL-4 in the regulation of energy balance, tumour development, and tumoural cell invasion. Hypoxia induced factor plays a prominent role in tumour macro- and microenvironment, by modulating the release of proinflammatory cytokines.

Decaffeinated green tea extract rich in epigallocatechin-3-gallate prevents fatty liver disease by increased activities of mitochondrial respiratory chain complexes in diet-induced obesity mice.

Nonalcoholic fatty liver disease has been considered the hepatic manifestation of obesity. It is unclear whether supplementation with green tea extract rich in epigallocatechin-3-gallate (EGCG) influences the activity of mitochondrial respiratory chain complexes and insulin resistance in the liver. EGCG regulated hepatic mitochondrial respiratory chain complexes and was capable of improving lipid metabolism, attenuating insulin resistance in obese mice. Mice were divided into four groups: control diet+water (CW) or EGCG (CE) and hyperlipidic diet+water (HFW) or EGCG (HFE). All animals received water and diets ad libitum for 16 weeks. Placebo groups received water (0.1 ml/day) and EGCG groups (0.1 ml EGCG and 50 mg/kg/day) by gavage. Cytokines concentrations were obtained by ELISA, protein expression through Western blotting and mitochondrial complex enzymatic activity by colorimetric assay of substrate degradation. HFW increased body weight gain, adiposity index, retroperitoneal and mesenteric adipose tissue relative weight, serum glucose, insulin and Homeostasis Model Assessment of Basal Insulin Resistance (HOMA-IR); glucose intolerance was observed in oral glucose tolerance test (OGTT) as well as ectopic fat liver deposition. HFE group decreased body weight gain, retroperitoneal and mesenteric adipose tissue relative weight, HOMA-IR, insulin levels and liver fat accumulation; increased complexes II-III and IV and malate dehydrogenase activities and improvement in glucose uptake in OGTT and insulin sensitivity by increased protein expression of total AKT, IRα and IRS1. We did not find alterations in inflammatory parameters analyzed. EGCG was able to prevent obesity stimulating the mitochondrial complex chain, increasing energy expenditure, particularly from the oxidation of lipid substrates, thereby contributing to the prevention of hepatic steatosis and improved insulin sensitivity.

The role of multicomponent therapy in the metabolic syndrome, inflammation and cardiovascular risk in obese adolescents.

Obesity is characterised by low-grade inflammation, which increases the metabolic syndrome (MetS) and cardiovascular risks. The aim of the present study was to verify the role of multicomponent therapy in controlling the MetS, inflammation and carotid intima-media thickness (cIMT) in obese adolescents. The second aim was to investigate the relationships between adipokines, the MetS parameters and cIMT. A total of sixty-nine obese adolescents participated in the present study and completed 1 year of multicomponent therapy (a combination of strategies involving nutrition, psychology, physical exercise and clinical therapy), and were divided according to their MetS diagnosis as follows: MetS (n 19); non-MetS (n 50). Blood analyses of glucose, lipid and adipokine concentrations (adiponectin, leptin, plasminogen activator inhibitor 1 (PAI-1) and C-reactive protein) were collected. Insulin resistance was assessed using the homeostasis model assessment for insulin resistance, quantitative insulin sensitivity check index and homeostasis model assessment-adiponectin. cIMT and visceral and subcutaneous fat were estimated using ultrasonography. At baseline, the MetS group presented higher waist circumference, glucose and insulin levels, and systolic and median blood pressures compared with the non-MetS group. After therapy, both groups showed improvements in the anthropometric profile, body composition, insulin level, insulin resistance, insulin sensibility, TAG and VLDL-cholesterol, adiponectin, leptin and PAI-1 levels, blood pressure and cIMT. The prevalence of the MetS was reduced from 27·5 to 13·0 %. Metabolic syndrome patients showed resistance in the attenuation of total cholesterol and LDL-cholesterol (LDL-C) levels and leptin:adiponectin and adiponectin:leptin ratios. In the MetS group, the variation in the adiponectin:leptin ratio was correlated with variations in glucose, insulin sensibility, total cholesterol, LDL-c and systolic blood pressure. Additionally, the number of MetS parameters was correlated with the carotid measurement. Moreover, the variation in cIMT was correlated with the variations in insulin sensibility, total cholesterol and LDL-c. For the entire group, the number of MetS alterations was correlated with the leptin level and leptin:adiponectin ratio and adiponectin:leptin ratio after therapy. In conclusion, multicomponent therapy was effective in controlling the MetS, inflammation and cIMT in the obese adolescents. However, the MetS patients showed resistance in the attenuation of the atherogenic lipid profile and leptin:adiponectin ratio and adiponectin:leptin ratio. These results suggest that the MetS patients have increased cardiovascular risks, and that it is important to attempt to control the inflammatory process that occurs due to obesity in clinical practice in order to improve the health of adolescents.

Type of fatty acids in maternal diets during pregnancy and/or lactation and metabolic consequences of the offspring.

During pregnancy and/or lactation, maternal nutrition is related to the adequate development of the fetus, newborn and future adult, likely by modifications in fetal programming and epigenetic regulation. Fetal programming is characterized by adaptive responses to specific environmental conditions during early life stages, which may alter gene expression and permanently affect the structure and function of several organs and tissues, thus influencing the susceptibility to metabolic disorders. Regarding lipid metabolism during the first two trimesters of pregnancy, the maternal body accumulates fat, whereas in late pregnancy, the lipolytic activity in the maternal adipose tissue is increased. However, an excess or deficiency of certain fatty acids may lead to adverse consequences to the fetuses and newborns. Fetal exposure to trans fatty acids appears to promote early deleterious effects in the offspring's health, thereby increasing the individual risk for developing metabolic diseases throughout life. Similarly, the maternal intake of saturated fatty acids seems to trigger alterations in the liver and adipose tissue function associated with insulin resistance and diabetes. The polyunsaturated fatty acids (PUFAs), particularly long-chain PUFAs (long-chain PUFA-arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid), play an important and beneficial physiologic role in the offspring who receive this fatty acid during critical periods of development. Therefore, the maternal nutritional condition and fatty acid intake during pregnancy and/or lactation are critical factors that are strongly associated with normal fetal and postnatal development, which influence the modifications in fetal programming and in the individual risk for developing metabolic diseases throughout life.

Green tea extract improves high fat diet-induced hypothalamic inflammation, without affecting the serotoninergic system.

To investigate possible mechanisms of green tea's anti-obesity and anti-diabetic effects in the hypothalamus, the central regulator of metabolism, of mice fed with high-fat diet (HFD), we analyzed proteins of the toll-like receptor 4 (TLR4) pathway and serotoninergic proteins involved in energy homeostasis. Thirty-day-old male Swiss mice were fed with HFD rich in saturated fat and green tea extract (GTE) for 8 weeks. After that, body weight and mass of fat depots were evaluated. Oral glucose tolerance test was performed 3 days prior to euthanasia; serum glucose, insulin and adiponectin were measured in fasted mice. Hypothalamic TLR4 pathway proteins, serotonin receptors 1B and 2C and serotonin transporter were analyzed by Western blotting or enzyme-linked immunosorbent assay. A second set of animals was used to measure food intake in response to fluoxetine, a selective serotonin reuptake inhibitor. Mice fed with HFD had increased body weight and mass of fat depots, impaired oral glucose tolerance, elevated glucose and insulin and decreased adiponectin serum levels. TLR4, IκB-α, nuclear factor κB p50 and interleukin 6 were increased by HFD. Concomitant GTE treatment ameliorated these parameters. The serotoninergic system remained functional after HFD treatment despite a few alterations in protein content of serotonin receptors 1B and 2C and serotonin transporter. In summary, the GTE attenuated the deleterious effects of the HFD investigated in this study, partially due to reduced hypothalamic inflammation.

Hyperleptinemia: implications on the inflammatory state and vascular protection in obese adolescents submitted to an interdisciplinary therapy.

The low-grade systemic inflammation seen in obesity may affect the actions of some adipose tissue-derived adipokines that are involved in the regulation of vascular function. We sought to verify whether hyperleptinemia may influence the inflammatory and atherogenic responses in obese adolescents undergoing interdisciplinary therapy. Thirty-four obese adolescents underwent interdisciplinary therapy for 1 year. Subjects were considered hyperleptinemic if they had baseline values of leptin above 20 ng/mL for boys and 24 ng/mL for girls. Both groups showed an improvement in body composition and a reduction in carotid intima-media thickness. However, only subjects in the non-hyperleptinemic group showed an increase in adiponectin concentration after therapy. Moreover, leptin concentration was positively correlated with adiponectin and inversely correlated with PAI-1 in this group. Hyperleptinemic state may impair the attenuation of inflammation in obese adolescents undergoing interdisciplinary therapy, particularly by impeding the increase in adiponectin concentration, which is directly involved in vascular protection.

Effect of fish oil intake on glucose levels in rat prefrontal cortex, as measured by microdialysis.

BACKGROUND: Brain glucose sensing may contribute to energy homeostasis control. The prefrontal cortex (PFC) participates in the hedonic component of feeding control. As high-fat diets may disrupt energy homeostasis, we evaluated in male Wistar rats whether intake of high-fat fish-oil diet modified cortical glucose extracellular levels and the feeding induced by intracerebroventricular glucose or PFC glucoprivation. METHODS: Glucose levels in PFC microdialysates were measured before and after a 30-min meal. Food intake was measured in animals receiving intracerebroventricular glucose followed, 30-min. later, by 2-deoxy-D-glucose injected into the PFC. RESULTS: The fish-oil group showed normal body weight and serum insulin while fat pads weight and glucose levels were increased. Baseline PFC glucose and 30-min. carbohydrates intake were similar between the groups. Feeding-induced PFC glucose levels increased earlier and more pronouncedly in fish-oil than in control rats. Intracerebroventricular glucose inhibited feeding consistently in the control but not in the fish-oil group. Local PFC glucoprivation with 2-DG attenuated glucose-induced hypophagia. CONCLUSIONS: The present experiments have shown that, following food intake, more glucose reached the prefrontal cortex of the rats fed the high-fat fish-oil diet than of the rats fed the control diet. However, when administered directly into the lateral cerebral ventricle, glucose was able to consistently inhibit feeding only in the control rats. The findings indicate that, an impairment of glucose transport into the brain does not contribute to the disturbances induced by the high-fat fish-oil feeding.