Acute exercise modulates the inflammatory response in adipose tissue in both lean and obese mice.

OBJECTIVES: Acute physical exercise acts as a metabolic stressor, promoting activation of the immune system, and this response could be relevant in the adipose tissue remodeling process. In addition, some cytokines have important functions in lipolysis. Because chronic exercise improves obesity-related metabolic and inflammatory dysfunction, herein we investigated the effect of acute exercise on the inflammatory responses in the adipose tissues of lean and obese mice. METHODS: Lean mice were fed a standard chow diet, whereas obese mice were fed a high-refined carbohydrate diet for 8 wk. Both groups were subjected to 60 min of moderate-intensity exercise. RESULTS: In the epididymal adipose tissue of lean mice, exercise enhanced interleukin (IL)-6 and tumor necrosis factor-α levels, which correlated positively with increased serum free fatty acid concentrations. In vivo confocal imaging of epididymal adipose tissue vessels revealed higher recruitment of neutrophils after exercise. Also, the number of leukocytes expressing CD11b+F480- was elevated 6 h after exercise. Similarly, the chemokine (C-X-C motif) ligand 1 level increased at 6 h and remained high until 24 h after exercise. Myeloperoxidase activity was increased at 6, 12, and 24 h after exercise. Surprisingly, however, no changes were observed in epididymal adipose tissue from obese mice, considering proinflammatory cytokines (IL-6 and tumor necrosis factor-α). On the other hand, IL-13, IL-4, and IL-10 levels were higher in obese mice after exercise. CONCLUSIONS: These data suggest that acute exercise promotes an inflammatory response in the adipose tissue of lean mice that is observed as part of its role in adipose tissue remodeling. In contrast, acute exercise promotes an antiinflammatory response in adipose tissue from obese mice, likely as an important tool for restoring homeostasis.

Protective Effect of Virgin Coconut Oil on Osteopenia Induced by High Refined Carbohydrate-Containing Diet in Mice.

BACKGROUND: Obesity leads to chronic low-grade inflammation, promoting detrimental effects on bone. The consumption of virgin coconut oil (VCO) is associated with benefits related to meta-inflammation. We evaluated the effect of VCO supplementation on osteopenia promoted by diet-induced obesity in mice. METHODS: Male BALB/c mice were fed a control (C) or highly refined carbohydrate-containing (HC) diet for eight weeks. After that, the HC diet group was supplemented with three doses of VCO for four weeks. RESULTS: The HC diet increased the adiposity and leptin levels associated with augmented systemic inflammatory cells improved with VCO supplementation. The HC diet reduced the trabecular bone in the tibia, lumbar vertebrae, distal and proximal femur, as well as the bone mineral density of the femur and alveolar bone. The VCO supplementation reverted bone osteopenia by increasing the trabecular bone in different sites and improving femur and alveolar bone microarchitecture. Although the reduced number of osteoblasts in the alveolar bone of the HC diet group was not significantly enhanced by VCO supplementation, the reduced Alp expression in the HC diet group was enhanced in the VCO group. These beneficial effects were associated with lowering the Rankl/Opg ratio. CONCLUSION: VCO supplementation might be an effective strategy to attenuate bone osteopenic effects induced by obesity.

PAF signaling plays a role in obesity-induced adipose tissue remodeling.

BACKGROUND/OBJECTIVES: Platelet-activating factor receptor (PAFR) activation controls adipose tissue (AT) expansion in animal models. Our objective was twofold: (i) to check whether PAFR signaling is involved in human obesity and (ii) investigate the PAF pathway role in hematopoietic or non-hematopoietic cells to control adipocyte size. MATERIALS/SUBJECTS AND METHODS: Clinical parameters and adipose tissue gene expression were evaluated in subjects with obesity. Bone marrow (BM) transplantation from wild-type (WT) or PAFR-/- mice was performed to obtain chimeric PAFR-deficient mice predominantly in hematopoietic or non-hematopoietic-derived cells. A high carbohydrate diet (HC) was used to induce AT remodeling and evaluate in which cell compartment PAFR signaling modulates it. Also, 3T3-L1 cells were treated with PAF to evaluate fat accumulation and the expression of genes related to it. RESULTS: PAFR expression in omental AT from humans with obesity was negatively correlated to different corpulence parameters and more expressed in the stromal vascular fraction than adipocytes. Total PAFR-/- increased adiposity compared with WT independent of diet-induced obesity. Differently, WT mice receiving PAFR-/--BM exhibited similar adiposity gain as WT chimeras. PAFR-/- mice receiving WT-BM showed comparable augmentation in adiposity as total PAFR-/- mice, demonstrating that PAFR signaling modulates adipose tissue expansion through non-hematopoietic cells. Indeed, the PAF treatment in 3T3-L1 adipocytes reduced fat accumulation and expression of adipogenic genes. CONCLUSIONS: Therefore, decreased PAFR signaling may favor an AT accumulation in humans and animal models. Importantly, PAFR signaling, mainly in non-hematopoietic cells, especially in adipocytes, appears to play a significant role in regulating diet-induced AT expansion.

Imaging and immunometabolic phenotyping uncover changes in the hepatic immune response in the early phases of NAFLD.

BACKGROUND & AIMS: The precise determination of non-alcoholic fatty liver disease (NAFLD) onset is challenging. Thus, the initial hepatic responses to fat accumulation, which may be fundamental to our understanding of NAFLD evolution and clinical outcomes, are largely unknown. Herein, we chronologically mapped the immunologic and metabolic changes in the liver during the early stages of fatty liver disease in mice and compared this with human NAFLD samples. METHODS: Liver biopsies from patients with NAFLD (NAFLD activity score [NAS] 2-3) were collected for gene expression profiling. Mice received a high-fat diet for short periods to mimic initial steatosis and the hepatic immune response was investigated using a combination of confocal intravital imaging, gene expression, cell isolation, flow cytometry and bone marrow transplantation assays. RESULTS: We observed major immunologic changes in patients with NAS 2-3 and in mice in the initial stages of NAFLD. In mice, these changes significantly increased mortality rates upon drug-induced liver injury, as well as predisposing mice to bacterial infections. Moreover, deletion of Toll-like receptor 4 in liver cells dampened tolerogenesis, particularly in Kupffer cells, in the initial stages of dietary insult. CONCLUSION: The hepatic immune system acts as a sentinel for early and minor changes in hepatic lipid content, mounting a biphasic response upon dietary insult. Priming of liver immune cells by gut-derived Toll-like receptor 4 ligands plays an important role in liver tolerance in initial phases, but continuous exposure to insults may lead to damage and reduced ability to control infections. LAY SUMMARY: Fatty liver is a very common form of hepatic disease, leading to millions of cases of cirrhosis every year. Patients are often asymptomatic until becoming very sick. Therefore, it is important that we expand our knowledge of the early stages of disease pathogenesis, to enable early diagnosis. Herein, we show that even in the early stages of fatty liver disease, there are significant alterations in genes involved in the inflammatory response, suggesting that the hepatic immune system is disturbed even following minor and undetectable changes in liver fat content. This could have implications for the diagnosis and clinical management of fatty liver disease.

SOCS2 modulates adipose tissue inflammation and expansion in mice.

INTRODUCTION: Obesity is usually triggered by a nutrient overload that favors adipocyte hypertrophy and increases the number of pro-inflammatory cells and mediators into adipose tissue. These mediators may be regulated by suppressors of cytokine signaling (SOCS), such as SOCS2, which is involved in the regulation of the inflammatory response of many diseases, but its role in obesity is not yet known. We aimed to investigate the role of SOCS2 in metabolic and inflammatory dysfunction induced by a high-refined carbohydrate-containing diet (HC). MATERIAL AND METHODS: Male C57BL/6 wild type (WT) and SOCS2 deficient (SOCS2-/-) mice were fed chow or an HC diet for 8 weeks. RESULTS: In general, SOCS2 deficient mice, independent of the diet, showed higher adipose tissue mass compared with their WT counterparts that were associated with decreased lipogenesis rate in adipose tissue, lipolysis in adipocyte culture and energy expenditure. An anti-inflammatory profile was observed in adipose tissue of SOCS2-/- by reduced secretion of cytokines, such as TNF and IL-6, and increased M2-like macrophages and regulatory T cells compared with WT mice. Also, SOCS2 deficiency reduced the differentiation/expansion of pro-inflammatory cells in the spleen but increased Th2 and Treg cells compared with their WT counterparts. CONCLUSION: The SOCS2 protein is an important modulator of obesity that regulates the metabolic pathways related to adipocyte size. Additionally, SOCS2 is an inflammatory regulator that appears to be essential for controlling the release of cytokines and the differentiation/recruitment of cells into adipose tissue during the development of obesity.

Mechanisms underlying fat pad remodeling induced by fasting: role of PAF receptor.

OBJECTIVES: Fasting has long been practiced for political and religious reasons and to lose weight. However, biological responses during fasting have yet to be fully understood. Previous studies have shown that cytokines may control fat pad expansion, at least in part, owing to the induction of lipolysis. Indeed, we have previously shown that mice with a lower inflammatory response, such as platelet-activating factor receptor knockout mice (PAFR-/-), are prone to gain weight and adiposity. The aims of this study were to determine whether adipose tissue becomes inflamed after fasting and to evaluate whether the PAF signaling is a factor in the fat loss induced by fasting. METHODS: Wild-type (WT) and PAFR-/- mice were fasted for 24 h. Adiposity, leukocyte recruitment, and cytokine levels were evaluated. Multiple comparisons were performed using two-way analysis of variance and post hoc Fisher exact test. RESULTS: After fasting, male WT mice showed lower adiposity (P < 0.001), higher recruitment of immune cells (P < 0.001), and increased cytokine levels (P < 0.05) in adipose tissue. Although WT mice lost ~79% of their adipose tissue mass, PAFR-/- mice lost only 36%. Additionally, PAFR-/- mice did not show enhanced cytokine and chemokine levels after fasting (P > 0.05). CONCLUSION: Despite low-grade inflammation being associated with metabolic syndrome, at least in part, the inflammatory milieu is also important to induce proper fat mobilization and remodeling of adipose tissue.

Role of adipose tissue inflammation in fat pad loss induced by fasting in lean and mildly obese mice.

Inflammation induced by obesity contributes to insulin resistance and atherosclerosis. Indeed, high levels of proinflammatory cytokines trigger chronic low-grade inflammation and promote detrimental metabolic effects in the adipose tissue. On the other hand, inflammation seems to control fat pad expansion and to have important functions on lipolysis and glucose metabolism. Thus, it is possible that inflammation may also drive fat pad loss, as seen during long-fast periods. Herein, we have used fasting as a strategy to induce weight loss and evaluate the possible role of inflammation on adipose tissue remodeling. Male BALB-c mice were fed with chow diet (lean mice) or with high-carbohydrate refined diet (mildly obese mice) for 8 weeks. After that, animals were subjected to 24 h of fasting. There was a 63% reduction of adiposity in lean mice following fasting. Furthermore, the adipose tissue was enriched of immune cells and had a higher content of IL-6, TNF-alpha, IL-10, TGF-ß and CXCL-1. Interestingly, mildly obese mice, subjected to the same 24-h fasting period, lost only 33% of their adiposity. Following fasting, these mice did not show any increment in leukocyte recruitment and cytokine levels, as did lean mice. Our findings indicate that inflammation participates in fat mass loss induced by fasting. Although the chronic low-grade inflammation seen in obesity is associated with metabolic diseases, a lower inflammatory response triggered by fasting in mildly obese mice impairs fat pad mobilization.

The usefulness of fine-needle aspirates for detection of recurrent carcinoma in the thyroid bed.

INTRODUCTION: Locoregional recurrence of thyroid carcinoma has a negative impact on patient prognosis. In the current study, we retrospectively reviewed cases of thyroid bed lesions in the last 3 years, correlating cytologic diagnoses with clinical findings and, whenever available, final surgical diagnosis. MATERIALS AND METHODS: Cytologic results and needle wash thyroglobulin results from patients with fine-needle aspiration (FNA) of thyroid bed lesions were retrospectively collected from our electronic files. Additional retrieved data included sex, age at diagnosis, previous thyroidectomy diagnosis, time lapse since surgery, and corresponding surgical diagnosis (whenever available). RESULTS: A total of 91 cases from 72 patients (54 F, 18 M) were retrieved from the electronic files, with a median age of 49 years. Average interval between surgery and thyroid bed FNA was 5 years. Thyroglobulin levels were available for 60 (65.2%) cases. The average level was 276.2 ug/mL, with a range of <0.1 to 4720 ug/mL. Information on final surgical diagnosis was available for 31 samples. Complete agreement between final cytologic and histologic diagnoses was achieved in 28 of 31 (90.3%) of the cases, with 1 false negative and 2 false positives. Cytology sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 95.2%, 71.4%, 90.9%, 83.3%, and 89.1%, respectively. CONCLUSIONS: Ultrasound-guided FNA is an accurate and minimally invasive diagnostic method for suspicious thyroid bed lesions, with high sensitivity and positive predictive value.

Aerobic training reduces immune cell recruitment and cytokine levels in adipose tissue in obese mice.

Obesity is associated with an energy imbalance that results from excessive energy intake, low diet quality, and a sedentary lifestyle. The increased consumption of a high-refined carbohydrate (HC) diet is strongly related to higher adiposity and low-grade inflammation. Aerobic training is a well-known nonpharmacological intervention to treat obesity and metabolic disturbances. However, the mechanisms through which aerobic training ameliorates the low-grade inflammation induced by an HC diet should be further investigated. Our hypothesis herein was that aerobic training would decrease the recruitment of leukocytes in adipose tissue, thereby reducing the levels of cytokines and improving metabolism in mice fed an HC diet. Male Balb/c mice were assigned to the following groups: control diet/nontrained (C-NT), control diet/trained (C-T), high-refined carbohydrate diet/nontrained (HC-NT), and high-refined carbohydrate diet/trained (HC-T). Mice were submitted to moderate-intensity training sessions that consisted of running 60 min per day for 8 weeks. An intravital microscopy technique was performed in vivo in anesthetized mice to visualize the microvasculature of the adipose tissue. The HC diet induced obesity and increased the influx of immune cells into the adipose tissue. In contrast, HC-T mice presented a lower adiposity and adipocyte area. Furthermore, relative to HC-NT mice, HC-T mice showed increased resting energy expenditure, decreased recruitment of immune cells in the adipose tissue, reduced cytokine levels, and ameliorated hyperglycemia and fatty liver deposition. Collectively, our data enhance understanding about the anti-inflammatory effect of aerobic training and shed light on the adipose tissue-mediated mechanisms by which training promotes a healthier metabolic profile.

Virgin coconut oil is effective to treat metabolic and inflammatory dysfunction induced by high refined carbohydrate-containing diet in mice.

The global rise in obesity rates is alarming since this condition is associated with chronic low-grade inflammation and secondary comorbidities as glucose intolerance, cardiovascular disease and liver damage. Therefore, a lot of dietary approaches are proposed to prevent and to treat obesity and its associated disorders. Virgin coconut oil (VCO) is well known as a functional food due to its significant amounts of medium-chain triglycerides. This study aimed to evaluate the effect of VCO on adiposity, metabolic and inflammatory dysfunctions induced by a high-refined carbohydrate-containing (HC) diet in mice. Male BALB/c mice were divided into two groups and fed with control (C) or HC diet to induce obesity for eight weeks. At the 9th week mice fed with HC diet were randomly regrouped into four groups, and were kept this way until the 12th week, as following: (i) HC diet alone or HC diet supplemented with three different VCO doses (ii) 1000 mg/kg, (iii) 3000 mg/kg and (iv) 9000 mg/kg. Regardless of the concentration used, VCO supplementation promoted lower adiposity and also improvement in glucose tolerance, lower serum glucose and lipid levels and decreased hepatic steatosis. Moreover, VCO intake induced a lower inflammatory response due to decreased number of leukocytes and TNF-α and IL-6 concentrations in adipose tissue, as well as reduced counts of total leukocytes, mononuclear and polymorphonuclear circulating cells. Our data showed that VCO can be considered as an interesting potential dietary approach to attenuate obesity and its metabolic and inflammatory alterations.

Ginger (Zingiber officinale Rosc.) Ameliorated Metabolic and Inflammatory Dysfunction Induced by High-Refined Carbohydrate-Containing Diet in Mice.

This study aimed to evaluate the effects and the mechanisms of ginger extract intake in the adiposity gain, metabolic and inflammatory disturbances induced by a high-refined carbohydrate (HC) diet in mice. Ginger extract at doses of 200, 600, and 1800 mg/kg was supplemented in the daily food of obese Balb/c mice during an 8-week experiment. Our findings indicate that consumption of high doses of ginger extracts prevents the increase of adiposity induced by HC diet, improves lipid profile, and promotes decrease of inflammatory markers in mice. We showed that ginger addition to HC diet leads to decrease in the recruitment of cells visualized in vivo in the microvasculature of adipose tissue, decrease of inflammatory cytokines, and increase of adiponectin serum levels. These results indicate that the consumption of ginger decreases the negative metabolic consequences induced by HC diet.

Osteopetrosis in obese female rats is site-specifically inhibited by physical training.

NEW FINDINGS: What is the central question of this study? Clinical studies suggest that obesity 'protects' against osteoporosis. However, these studies used only bone densitometry and assessed only one bone site, which is insufficient to enable conclusions to be drawn about the response of the whole skeleton. Furthermore, the effects of exercise on bone responses in obesity have not been explored previously. What is the main finding and what is its importance? We show that obesity causes osteopetrosis. Therefore, the classical perspective of 'protective effects of obesity' needs to be reviewed, and exercise is an important tool to avoid these alterations and to maintain the homeostasis of bone. A sedentary lifestyle and obesity induce systemic inflammatory responses. Although the effects of physical inactivity on osseous tissue have been well established, the effects of obesity on bone tissue remain controversial. Furthermore, the effects of physical training on bone tissue responses in the presence of diet-induced obesity are unknown. Our aim was to investigate the effects of obesity and physical training at multiple bone sites in rats. Female Wistar rats were divided into the following four groups: (i) control diet, non-trained (C-NT); (ii) high-refined carbohydrate-containing diet, non-trained (HC-NT); (iii) control diet, trained (C-T); and (iv) high-refined carbohydrate-containing diet, trained (HC-T). At 5 months of age, the rats were submitted to daily exercise for 30 min day(-1). After 13 weeks, blood samples, adipose and skeletal tissues were harvested. Two-way ANOVA was applied to detect differences (significance accepted when P ≤ 0.05). The HC-NT group exhibited increased body mass, adiposity, serum leptin, serum insulin, insulin resistance index and concentrations of tumour necrosis factor-α and interleukin-6. Obese rats (HC-NT) exhibited thickening of nasal bones, trabecular bones in the lumbar vertebrae and long bones in a site-dependent manner. The HC-T group exhibited similar adiposity and inflammatory results. Morphological analysis of the lumbar vertebrae in rats fed the HC diet revealed characteristics of osteopetrosis that were inhibited by exercise. In conclusion, the HC diet induced obesity and inflammatory/hormonal alterations and increased the trabecular bone in a site-dependent manner. However, obesity caused osteopetrosis in the lumbar vertebrae, which could be inhibited by physical training. Although exercise inhibited the development of bone alterations, physical training did not inhibit the HC diet-induced obesity responses.

Exercising for food: bringing the laboratory closer to nature.

Traditionally, exercise physiology experiments have borne little resemblance to how animals express physical activity in the wild. In this experiment, 15 adult male rats were divided into three equal-sized groups: exercise contingent (CON), non-exercise contingent (NON) and sedentary (SED). The CON group was placed in a cage with a running wheel, where the acquisition of food was contingent upon the distance required to run. Every 3 days the distance required to run to maintain food intake at free feeding levels was increased by 90% in comparison to the previous 3 days. The NON group was housed identically to the CON group, but food acquisition was not dependent upon running in the wheel. Finally, the SED group was kept in small cages with no opportunity to perform exercise. A two-way ANOVA with repeated measures was used to determine significant differences in responses between the experimental phases and treatment groups, and ANCOVA was used to analyse growth and tissue mass variables with body length and body mass used separately as covariates. A post hoc Tukey's test was used to indicate significant differences. A Pearson's correlation was used to test the relationship between the distance travelled by the animal and the distance/food ratio. The level of significance was set at P<0.05 for all tests. The CON group showed the hypothesized correlation between distance required to run to obtain food and the mean distance travelled (P<0.001), during 45 days in the contingency phase. This group showed a decrease in body mass, rather than an increase as shown by NON and SED groups. The CON group had a significantly lower body temperature (P<0.05) and adiposity (P<0.05) when compared with the other two groups for the same body size. The present experimental model based on animals choosing the characteristics of their physical exercise to acquire food (i.e. distance travelled, speed and duration) clearly induced physiological effects (body characteristics and internal temperature), which are useful for investigating relevant topics in exercise physiology such as the link between exercise, food and body mass.

Adiposidade e perfil metabólico em crianças de escolas da zona urbana de Ouro Preto-MG / Adiposity and metabolic profile of schoolchildren in the urban areas of Ouro Preto, Minas Gerais

A obesidade, doença multifatorial definida como excesso de gordura corporal, apresenta concomitância entre fatores de risco genéticos e ambientais. O diagnóstico precoce e as intervenções no período crítico do desenvolvimento da obesidade - infância e adolescência - têm sido recomendados, buscando-se evitar desfechos desfavoráveis na idade adulta. Este estudo transversal teve como objetivo caracterizar perfil lipídico, glicemia, adiponectina, leptina e grelina de escolares entre seis e nove anos, portadores de sobrepeso e obesidade, do município de Ouro Preto-MG. Os dados foram analisados a partir do teste de normalidade Shapiro Wilk; e nas comparações entre os grupos foi aplicado o teste paramétrico (Teste t) ou não paramétrico (Teste Mann Whitney), adotando-se intervalo de confiança de 95% e nível de significância para valores ≤ 0,05. A idade média da população escolar foi de 7,8 ± 1,1 anos, com prevalência de 8,9% de sobrepeso e 3% de obesidade. Foram identificados hipercolesterolemia em 5,5%, HDL alterado em 98,7%, taxa limítrofe de LDL em 32,4% e glicemia alterada em 46,6% das crianças. Na análise estratificada quanto ao gênero, foram observados valores maisaltos para leptina em meninas (p=0,032) e grelina nos meninos (p=0,033), não havendo diferença para as demais variáveis. Os resultados demonstram ser o excesso de peso entre escolares problema de saúde relevante no município, ressaltando-se a importância de implementação de programa de intervenção precoce por parte dos gestores. Elucidar os precursores da obesidade na infância pode levar a intervenções capazes de atenuar ou impedir suas consequências na juventude e fase adulta.

Obesity, defined as an excess in body fat, is a multifactorial disease involving both genetic and environmental risk factors. Early diagnosis and interventions during critical periods of development of obesity - childhood and adolescence - have been recommended, aiming at preventing unfavorable outcomes at a later age. This cross-sectional study sought tocharacterize the lipid profile, glucose, adiponectin, leptin and ghrelin in schoolchildren between six and nine years of age with overweight and obesity in the city of Ouro Preto (MG). The data was analyzed with the Shapiro Wilk normality test, groups comparisons were made with either a parametric (T test) or a nonparametric (Mann Whitney) test, adopting confidence intervals of 95% and a significance level of ≤ 0.05. The average age of the school population was 7.8 ± 1.1 years, with a prevalence of 8.9% of overweight and 3% of obesity. Hypercholesterolemia was found in 5.5%, HDL was abnormal in 98.7%, LDL levels were borderline in 32.4% and altered glucose levels were present in 46.6% of the children. In stratified analysis by gender, higher values of leptin in girls (p = 0.032) and ghrelin in boys (p = 0.033) were found, with no difference for the other variables. The results show that overweight/obesity among schoolchildren should be considered a significant health problem in this population, highlighting the importanceof implementing early intervention programs. Uncovering the precursors of childhood obesity could lead to interventions so as to prevent or mitigate its consequences in youth and adulthood.