High-fat diet induces increased tissue expression of TNF-alpha

Miso, fermented soybean paste, suppresses high-fat/high-sucrose diet-induced muscle atrophy in mice

This study investigated the effects of miso, a traditional fermented soybean food in Japan, on muscle mass atrophy. Eight week old male C57BL/6J mice were fed high fat/high sucrose diet with or without miso for 12 weeks. A miso diet increased soleus muscle weights (p<0.05) and reduced intraperitoneal glucose tolerance and insulin tolerance (p<0.05). The miso diet downregulated the Tnfα and Ccl2 expression, related to inflammation, and Trim63 and Fbxo32 expression, related to muscle atrophy, in the soleus muscle (p<0.05). The miso diet increased short-chain fatty acids levels, including acetic, propanoic, and butanoic acids, in the feces, serum, and soleus muscle (p<0.05). According to the LEfSe analysis, the miso diet increased family Prevotellaceae, family Christensenellaceae, family Dehalobacterium, family Desulfitibacter; family Deferribacteraceae, order Deferribacterales, class Deferribacteres; and family Gemmatimonadaceae, order Gemmatimonadetes, and class Gemmatimonadales, whereas the miso diet decreased family Microbacteriaceae, order Micrococcales, class Actinobacteria, and family Lactobacillaceae. Miso suppressed high fat/high sucrose diet induced impaired glucose tolerance, low muscle strength, and muscle atrophy by improving dysbiosis and increasing short-chain fatty acids production and provides new insights into the preventive effects of fermented foods on sarcopenia.

The Role of Organokines in Obesity and Type 2 Diabetes and Their Functions as Molecular Transducers of Nutrition and Exercise

Maintaining systemic homeostasis requires the coordination of different organs and tissues in the body. Our bodies rely on complex inter-organ communications to adapt to perturbations or changes in metabolic homeostasis. Consequently, the liver, muscle, and adipose tissues produce and secrete specific organokines such as hepatokines, myokines, and adipokines in response to nutritional and environmental stimuli. Emerging evidence suggests that dysregulation of the interplay of organokines between organs is associated with the pathophysiology of obesity and type 2 diabetes (T2D). Strategies aimed at remodeling organokines may be effective therapeutic interventions. Diet modification and exercise have been established as the first-line therapeutic intervention to prevent or treat metabolic diseases. This review summarizes the current knowledge on organokines secreted by the liver, muscle, and adipose tissues in obesity and T2D. Additionally, we highlighted the effects of diet/nutrition and exercise on the remodeling of organokines in obesity and T2D. Specifically, we investigated the ameliorative effects of caloric restriction, selective nutrients including ω3 PUFAs, selenium, vitamins, and metabolites of vitamins, and acute/chronic exercise on the dysregulation of organokines in obesity and T2D. Finally, this study dissected the underlying molecular mechanisms by which nutrition and exercise regulate the expression and secretion of organokines in specific tissues.

Anti-Inflammatory Diets in Fertility: An Evidence Review

Infertility is a global health concern affecting 48 million couples and 186 million individuals worldwide. Infertility creates a significant economic and social burden for couples who wish to conceive and has been associated with suboptimal lifestyle factors, including poor diet and physical inactivity. Modifying preconception nutrition to better adhere with Food-Based Dietary Guidelines (FBDGs) is a non-invasive and potentially effective means for improving fertility outcomes. While several dietary patterns have been associated with fertility outcomes, the mechanistic links between diet and infertility remain unclear. A key mechanism outlined in the literature relates to the adverse effects of inflammation on fertility, potentially contributing to irregular menstrual cyclicity, implantation failure, and other negative reproductive sequelae. Therefore, dietary interventions which act to reduce inflammation may improve fertility outcomes. This review consistently shows that adherence to anti-inflammatory diets such as the Mediterranean diet (specifically, increased intake of monounsaturated and n-3 polyunsaturated fatty acids, flavonoids, and reduced intake of red and processed meat) improves fertility, assisted reproductive technology (ART) success, and sperm quality in men. Therefore, integration of anti-inflammatory dietary patterns as low-risk adjunctive fertility treatments may improve fertility partially or fully and reduce the need for prolonged or intensive pharmacological or surgical interventions.

Raspberry and blackberry act in a synergistic manner to improve cardiac redox proteins and reduce NF-κB and SAPK/JNK in mice fed a high-fat, high-sucrose diet

BACKGROUND AND AIMS

Increased cardiac inflammation and oxidative stress are common features in obesity, and toll-like receptor (TLR)4 signaling is a key inflammatory pathway in this deleterious process. This study aimed to investigate whether berries could attenuate the detrimental effects of a high-fat, high-sucrose (HFHS) diet on the myocardium at the molecular level.

METHODS AND RESULTS

Eight-week-old male C57BL/6 mice consumed a low-fat, low-sucrose (LFLS) diet alone or supplemented with 10% blackberry (BL), 10% raspberry (RB) or 10% blackberry + raspberry (BL + RB) for four weeks. Animals were then switched to a HFHS diet for 24 weeks with or without berry supplementation or maintained on a LFLS control diet without berry supplementation. Left ventricles of the heart were isolated for protein and mRNA analysis. Berry consumption, particularly BL + RB reduced NADPH-oxidase (NOX)1 and NOX2 and increased catalase (CAT) and superoxide dismutase (SOD)2, expression while BL and RB supplementation alone was less efficacious. Downstream TLR4 signaling was attenuated mostly by both RB and BL + RB supplementation, while NF-κB pathway was attenuated by BL + RB supplementation. Stress-activated protein kinase (SAPK)/Jun amino-terminal kinase (JNK) was also attenuated by BL + RB supplementation, and reduced TNF-α transcription and protein expression was observed only with BL + RB supplementation.

CONCLUSION

The synergistic effects of BL + RB may reduce obesity-induced cardiac inflammation and oxidative stress to a greater extent than BL or RB alone.

Probiotics Function as Immunomodulators in the Intestine in C57Bl/6 Male Mice Exposed to Inhaled Diesel Exhaust Particles on a High-Fat Diet

Epidemiological studies reveal a correlation between air pollution exposure and gastrointestinal (GI) diseases, yet few studies have investigated the role of inhaled particulate matter on intestinal integrity in conjunction with a high-fat (HF) diet. Additionally, there is currently limited information on probiotics in mitigating air-pollutant responses in the intestines. Thus, we investigated the hypothesis that exposure to inhaled diesel exhaust particles (DEP) and a HF diet can alter intestinal integrity and inflammation, which can be attenuated with probiotics. 4-6-w-old male C57Bl/6 mice on a HF diet (45% kcal fat) were randomly assigned to be exposed via oropharyngeal aspiration to 35 µg of DEP suspended in 35 µL of 0.9% sterile saline or sterile saline (CON) only twice a week for 4 w. A subset of mice was treated with 0.3 g/day of Winclove Ecologic^® barrier probiotics (PRO) in drinking water throughout the duration of the study. Our results show that DEP exposure ± probiotics resulted in increased goblet cells and mucin (MUC)-2 expression, as determined by AB/PAS staining. Immunofluorescent quantification and/or RT-qPCR showed that DEP exposure increases claudin-3, occludin, zona occludens (ZO)-1, matrix metalloproteinase (MMP)-9, and toll-like receptor (TLR)-4, and decreases tumor necrosis factor (TNF)-α and interleukin (IL)-10 expression compared to CON. DEP exposure + probiotics increases expression of claudin-3, occludin, ZO-1, TNF-α, and IL-10 and decreases MMP-9 and TLR-4 compared to CON + PRO in the small intestine. Collectively, these results show that DEP exposure alters intestinal integrity and inflammation in conjunction with a HF diet. Probiotics proved fundamental in understanding the role of the microbiome in protecting and altering inflammatory responses in the intestines following exposure to inhaled DEP.

TGR5 Expression Is Associated with Changes in the Heart and Urinary Bladder of Rats with Metabolic Syndrome

Adipose-derived cytokines may contribute to the inflammation that occurs in metabolic syndrome (MetS). The Takeda G protein-coupled receptor (TGR5) regulates energy expenditure and affects the production of pro-inflammatory biomarkers in metabolic diseases. Etanercept, which acts as a tumor necrosis factor (TNF)-α antagonist, can also block the inflammatory response. Therefore, the interaction between TNF-α and TGR5 expression was investigated in rats with high-fat diet (HFD)-induced obesity. Heart tissues isolated from the HFD-induced MetS rats were analyzed. Changes in TGR5 expression were investigated with lithocholic acid (LCA) as the agonist. Betulinic acid (BA) was used to activate TGR5 in urinary bladders. LCA was more effective in the heart tissues of HFD-fed rats, although etanercept alleviated the function of LCA. STAT3 activation and higher TGR5 expression were observed in the heart tissues collected from HFD-fed rats. Thus, cardiac TGR5 expression is promoted by HFD through STAT3 activation in rats. Moreover, the urinary bladders of female rats fed a HFD showed a low response, which was reversed by etanercept. Relaxation by BA in the bladders was more marked in HFD-fed rats. The high TGR5 expression in HFD-fed rats was characterized using a mRNA assay, and the increased cAMP levels were found to be stimulated by BA in the isolated bladders. Therefore, TGR5 expression increases with a HFD in both the hearts and urinary bladders. Collectively, cytokine-medicated TGR5 activation was observed in the hearts and urinary bladders of rats.

Etanercept Ameliorates Cardiac Fibrosis in Rats with Diet-Induced Obesity

Diet-induced obesity (DIO) is considered the main risk factor for cardiovascular diseases. Increases in the plasma levels of tumor necrosis factor alpha (TNF-α) is associated with DIO. Etanercept, a TNF-α inhibitor, has been shown to alleviate cardiac hypertrophy. To investigate the effect of etanercept on cardiac fibrosis in DIO model, rats on high fat diet (HFD) were subdivided into two groups: the etanercept group and vehicle group. Cardiac injury was identified by classic methods, while fibrosis was characterized by histological analysis of the hearts. Etanercept treatment at 0.8 mg/kg/week twice weekly by subcutaneous injection effectively alleviates the cardiac fibrosis in HFD-fed rats. STAT3 activation seems to be induced in parallel with fibrosis-related gene expression in the hearts of HFD-fed rats. Decreased STAT3 activation plays a role in the etanercept-treated animals. Moreover, fibrosis-related genes are activated by palmitate in parallel with STAT3 activation in H9c2 cells. Etanercept may inhibit the effects of palmitate, but it is less effective than a direct inhibitor of STAT3. Direct inhibition of STAT3 activation by etanercept seems unlikely. Etanercept has the ability to ameliorate cardiac fibrosis through reduction of STAT3 activation after the inhibition of TNF-α and/or its receptor.

Improving Age-Related Cognitive Decline through Dietary Interventions Targeting Mitochondrial Dysfunction

Aging is inevitable and it is one of the major contributors to cognitive decline. However, the mechanisms underlying age-related cognitive decline are still the object of extensive research. At the biological level, it is unknown how the aging brain is subjected to progressive oxidative stress and neuroinflammation which determine, among others, mitochondrial dysfunction. The link between mitochondrial dysfunction and cognitive impairment is becoming ever more clear by the presence of significant neurological disturbances in human mitochondrial diseases. Possibly, the most important lifestyle factor determining mitochondrial functioning is nutrition. Therefore, with the present work, we review the latest findings disclosing a link between nutrition, mitochondrial functioning and cognition, and pave new ways to counteract cognitive decline in late adulthood through diet.

Differential Protein Metabolism and Regeneration in Gastrocnemius Muscles in High-fat Diet Fed Mice and Pre-hibernation Daurian Ground Squirrels: A Comparison between Pathological and Healthy Obesity

We focused on pathological obesity induced by excessive fat intake (nutritional obesity) in non-hibernator and healthy obesity due to pre-hibernation (PRE) fat storage in hibernator to study the effects of different types of obesity on skeletal muscle protein metabolism and cell regeneration. Kunming mice were fed with high-fat diet for 3 months to construct a pathological obesity model. Daurian ground squirrels fattened naturally before hibernation were used as a healthy obesity model. Body weight, adipose tissue wet weight, gastrocnemius muscle wet weight, muscle fiber cross-sectional area (CSA) and fiber type distribution were measured. The protein expression levels related to protein degradation (MuRF-1, atrogin-1, calpain1, calpain2, calpastatin, desmin, troponin T, Beclin-1, LC3-II), protein synthesis (P-Akt, P-mTORC1, P-S6K1, P-4E-BP1) and cell regeneration (MyoD, myogenin, myostatin) were detected by Western blot. As a result, the body weight and adipose tissue wet weight were both significantly increased in high fat obese (OB) mice and pre-hibernation fat (PRE) ground squirrels. The muscle wet weight, ratio of muscle wet weight to body weight, and muscle fiber CSA were significantly decreased, while the percentage of MHC I fiber isoform was significantly increased in gastrocnemius muscle of OB mice compared with the control (CON) group. The protein expression levels of P-Akt, P-mTORC1, P-4E-BP1 and myogenin were significantly decreased, while those of calpain1, calpain2, MuRF-1 and myostatin were significantly increased in the OB mice. In the ground squirrels, the muscle wet weight, muscle fiber CSA and percentage of MHC I fiber isoform all showed no change in the gastrocnemius muscle in the PRE group compared with the summer active (SA) group. The protein expression levels of P-Akt, P-mTORC1, P-S6K1 and MyoD were significantly increased, while those of Beclin-1 and LC3-II were significantly decreased in the PRE ground squirrels. This study demonstrated that the decrease in protein expression levels in the Akt/mTOR pathway (P-Akt, P-mTORC1 and P-4E-BP1) and cell regeneration (myogenin) and the increase in protein expression levels of the calpain pathway (calpain1 and calpain2) and ubiquitin-proteasome pathway (MuRF-1) were involved in the mechanism of muscle atrophy in gastrocnemius muscle of the pathologically obese Kunming mice induced by high-fat diet. In contrast, the increased protein expression levels of the Akt/mTOR pathway (P-Akt, P-mTORC1 and P-S6K1) and cell regeneration (MyoD), and the decreased protein expression levels of the autophagy lysosomal pathway (Beclin-1 and LC3-II) were involved in the mechanism of anti-atrophy in gastrocnemius muscle of the healthy obese ground squirrels fattened before hibernation.

Antioxidant and Anti-Inflammatory Potential of Polyphenols Contained in Mediterranean Diet in Obesity: Molecular Mechanisms

Nutrition transition can be defined as shifts in food habits, and it is characterized by high-fat (chiefly saturated animal fat), hypercaloric and salty food consumption at the expense of dietary fibers, minerals and vitamins. Western dietary patterns serve as a model for studying the impact of nutrition transition on civilization diseases, such as obesity, which is commonly associated with oxidative stress and inflammation. In fact, reactive oxygen species (ROS) overproduction can be associated with nuclear factor-κB (NF-κB)-mediated inflammation in obesity. NF-κB regulates gene expression of several oxidant-responsive adipokines including tumor necrosis factor-α (TNF-α). Moreover, AMP-activated protein kinase (AMPK), which plays a pivotal role in energy homeostasis and in modulation of metabolic inflammation, can be downregulated by IκB kinase (IKK)-dependent TNF-α activation. On the other hand, adherence to a Mediterranean-style diet is highly encouraged because of its healthy dietary pattern, which includes antioxidant nutraceuticals such as polyphenols. Indeed, hydroxycinnamic derivatives, quercetin, resveratrol, oleuropein and hydroxytyrosol, which are well known for their antioxidant and anti-inflammatory activities, exert anti-obesity proprieties. In this review, we highlight the impact of the most common polyphenols from Mediterranean foods on molecular mechanisms that mediate obesity-related oxidative stress and inflammation. Hence, we discuss the effects of these polyphenols on a number of signaling pathways. We note that Mediterranean diet (MedDiet) dietary polyphenols can de-regulate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and NF-κB-mediated oxidative stress, and metabolic inflammation. MedDiet polyphenols are also effective in upregulating downstream effectors of several proteins, chiefly AMPK.

The Effect of Short-Term Feeding of a High-Coconut Oil or High-Fat Diet on Neuroinflammation and the Performance of an Object-Place Task in Rats

The consumption of high-fat and high-sugar diets, in the form of junk food, and binge eating are now common. Increasing evidence suggests that a high-fat diet (HFD) can induce neuroinflammation and alter behavior. I aimed to study the effects of diets of differing fat content on neuroinflammation and spatial memory using an object-place (OP) task. Thirty-two adult male rats were allocated to four groups and fed a regular diet (Regular diet), a control diet (Control diet), an HFD (60% of calories from lard), or a high-coconut oil diet (HCOD; 60% of calories from coconut oil) for 3 days. Their water intake, food consumption, body mass, and metabolic variables were measured. HFD-fed rats showed significantly poorer performance on the OP task, as assessed using the discrimination index (- 0.208 ± 0.094), than the Regular (0.462 ± 0.078; P < 0.0001) and Control (0.379 ± 0.081; P = 0.0003) groups. However, no significant difference was observed in spatial memory between the HCOD and Regular groups. The concentrations of neuroinflammatory markers (interleukin [IL]-1β, IL-6, tumor necrosis factor α, and nuclear factor κB) were also measured in the hippocampus and prefrontal cortex. HFD-fed rats showed significantly higher levels of neuroinflammatory markers than the Regular and Control diet-fed groups. HCOD feeding did not induce neuroinflammation in the hippocampus and prefrontal cortex compared with the Regular and Control groups.

The Effects of Dairy Product and Dairy Protein Intake on Inflammation: A Systematic Review of the Literature

Systemic inflammation is associated with obesity and chronic disease risk. Intake of dairy foods is associated with reduced risk of type 2 diabetes and cardiovascular disease; however, the impact of dairy foods on inflammation is not well-established. The objective of this study was to conduct a systematic review to evaluate the effect of dairy product (milk, cheese, and yogurt) and dairy protein consumption on low-grade systemic inflammation in adults without severe inflammatory disorders. A literature search was completed in September 2019 using PubMed and CENTRAL as well as inspection of reference lists from relevant review articles. The search resulted in the identification of 27 randomized controlled trials which were included in this analysis. In the 19 trials which evaluated dairy products, 10 reported no effect of the intervention, while 8 reported a reduction in at least one biomarker of inflammation. All 8 trials that investigated dairy protein intake on markers of inflammation reported no effect of the intervention. The available literature suggests that dairy products and dairy proteins have neutral to beneficial effects on biomarkers of inflammation. Additional clinical studies designed using inflammatory biomarkers as the primary outcome are needed to fully elucidate the effects of dairy intake on inflammation.

Andrographis paniculata Improves Insulin Resistance in High-Fat Diet-Induced Obese Mice and TNFα-Treated 3T3-L1 Adipocytes

Pro-inflammatory cytokines interfere with blood glucose homeostasis, which leads to hyperglycemia. Andrographis paniculata (AP) has been shown to possess anti-inflammatory activity and to reduce blood glucose levels in diabetes. The two major bioactive diterpenoids in AP, andrographolide (AND) and 14-deoxy-11,12-didehydroandrographolide (deAND), have potent anti-inflammatory activity. We studied whether APE (an ethanolic extract of AP), AND, and deAND could improve a high-fat diet (HFD)-induced hyperglycemia in vivo and TNF[Formula: see text]-induced impairment of insulin signaling in vitro. Male C57BL/6JNarl mice were fed a normal diet (ND) or the HFD, and the fatty mice were treated with APE, deAND, or AND for 16 weeks. 3T3-L1 cells were used to study the underlying mechanisms by which APE, deAND, or AND attenuated TNF[Formula: see text]-induced insulin resistance. The HFD significantly induced obesity, hyperglycemia, insulin resistance, and inflammation, whereas APE and deAND significantly ameliorated HFD-induced obesity, hyperglycemia, insulin resistance, and TNF[Formula: see text] production. The HFD significantly impaired insulin signaling by decreasing the protein expression of p-IRS1 tyr632 and p-AKT ser473, as well as the membrane translocation of GLUT4 in response to insulin stimulation in epididymal adipose tissue. HFD-impaired the membrane translocation of GLUT4 was significantly reversed by deAND and APE. In addition, deAND and APE markedly reversed the detrimental effect of TNF[Formula: see text] on the insulin signaling pathway and glucose uptake in 3T3-L1 cells. Despite no significant positive effect on p-AS160, a trend for recovery by deAND and APE was observed. These results suggest that deAND and APE protect against HFD-induced insulin resistance by ameliorating inflammation-driven impairment of insulin sensitivity.

Consumption of a high energy density diet triggers microbiota dysbiosis, hepatic lipidosis, and microglia activation in the nucleus of the solitary tract in rats

Introduction

Obesity is a multifactorial chronic inflammatory disease. Consumption of high energy density (HED) diets is associated with hyperphagia, increased body weight and body fat accumulation, and obesity. Our lab has previously shown that short-term (4 weeks) consumption of a HED diet triggers gut microbiota dysbiosis, gut inflammation, and reorganization of the gut-brain vagal communication.

Objetives

The aim of this study was to investigate the effect of long-term (6 months) consumption of HED diet on body composition, gut microbiome, hepatocellular lipidosis, microglia activation in the nucleus of the solitary tract, and systemic inflammation.

Methods

Male Sprague–Dawley rats were fed a low energy density (LED) diet for 2 weeks and then switched to a HED diet for 26 weeks. Twenty-four-hour food intake, body weight, and body composition were measured twice a week. Blood serum and fecal samples were collected at baseline, 1, 4, 8, and 26 weeks after introduction of the HED diet. Serum samples were used to measure insulin, leptin, and inflammatory cytokines using Enzyme-linked Immunosorbent Assay. Fecal samples were assessed for 16 S rRNA genome sequencing.

Results

HED diet induced microbiota dysbiosis within a week of introducing the diet. In addition, there was significant microglia activation in the intermediate NTS and marked hepatic lipidosis after 4 weeks of HED diet. We further observed changes in the serum cytokine profile after 26 weeks of HED feeding.

Conclusions

These data suggest that microbiota dysbiosis is the first response of the organism to HED diets, followed by increased liver fat accumulation, microglia activation in the brain, and circulating levels of inflammatory markers. To our knowledge, this is the first study to present longitudinal and cross-sectional results on effect of long-term consumption of HED diets on all these parameters in a single cohort of animals.

Short-Term Administration of a High-Fat Diet Impairs Wound Repair in Mice

High intake of dietary fat plays an important role in obesity development in animals and humans, and prolonged intake of high-fat diet might lead to low-grade chronic inflammation. Previous study showed that diet-induced overweight delays cutaneous wound healing in both obesity-prone and obesity-resistant animals, highlighting the importance of diet composition in the wound healing process. This study evaluated the hypothesis that a short-term administration of high-fat diet could affect cutaneous wound healing. Male mice (C57/bl6) were randomly divided into standard (10% energy from fat) or high-fat (60% energy from fat) chow groups. After 10 days of diet administration, an excisional lesion was performed and the animals were sacrificed 6 or 10 days later. There was no difference in the fasting blood glucose between groups. Ten days after wounding, high-fat chow group presented increased inflammatory infiltrate, levels of inducible nitric oxide synthase and cyclo-oxygenase-2 proteins, and lipid peroxidation. The high-fat chow group presented delayed wound closure, increased amount of myofibroblasts and vessels, and decreased deposition of type I collagen. These findings support the hypothesis that short-term administration of high-fat diet exerts negative effects on mice cutaneous wound healing, due to the interference in the inflammatory phase.

Role of Proinflammatory Cytokines in Feedback Modulation of Circadian Clock Gene Rhythms by Saturated Fatty Acids

Proinflammatory signaling cascades have been implicated in the mechanism by which high fat diet (HFD) and saturated fatty acids (SFA) modulate fundamental circadian properties of peripheral clocks. Because the cytokines TNFα and IL-6 are key signals in HFD- and SFA-induced proinflammatory responses that ultimately lead to systemic insulin resistance, the present study examined the roles of these cytokines in the feedback modulation of peripheral circadian clocks by the proinflammatory SFA, palmitate. IL-6 and TNFα secretion in Bmal1-dLuc fibroblast cultures was increased during palmitate treatment although the time course and amplitude of the inductive response differed between these cytokines. Similar to the time-dependent phase shifts observed in response to palmitate, treatment with IL-6 or with the low dose (0.1 ng/ml) of TNFα at hour 12 (i.e., after forskolin synchronization) induced phase advances of fibroblast Bmal1-dLuc rhythms. In complementary experiments, treatment with neutralizing antibodies against these proinflammatory cytokines or their receptors to inhibit of IL-6- or TNFα-mediated signaling repressed palmitate-induced phase shifts of the fibroblast clock. These studies suggest that TNFα, IL-6 and other proinflammatory cytokines may mediate the feedback modulation of peripheral circadian clocks by SFA-induced inflammatory signaling.

Low-intensity current (LIC) stimulation of subcutaneous adipose derived stem cells (ADSCs) - A missing link in the course of LIC based wound healing

Millions of people die as a result of fatal injuries accounting for 9% of the total global annual deaths. Non fatal injuries generally result in variety of wounds. The normal wound healing process is slow and takes weeks to months, depending on the type of wound. In last two decades, electrotherapy called low-intensity currents (LIC) for the treatment became popular for faster wound healing, as well as in management of nonresponding and ulcerative wounds. It was reported that LIC mimics 'the current of injury' which is generated by body on wounding and helps in faster wound healing. Researchers have also studied the migration of localized cell and other bio-molecules under the influence of LIC helping the wound to heal faster. Literature review has also suggested that, electrical stimulation of isolated adipose tissue derived stem cells (ADSCs) releases growth factors and differentiates in to specialized cells like fibroblasts and keratinocytes in laboratory conditions. These research areas are well explored and emerged as independent state-of-the-arts therapies and technologies. Considering the fact, that adipose tissue (along with ADSCs) is present subcutaneously, a new hypothesis is proposed which states that 'low intensity current (LIC) stimulation of wound stimulates subcutaneous adipose tissue containing ADSCs which releases different growth factors and also differentiates into certain cells like fibroblasts, neurons and keratinocytes. These cells easily migrate to wound site due to lipolysis and loosening of fat tissue, resulting in faster wound healing'. Thus this hypothesis provides a missing link between two state of the art technologies; first one is 'LIC based electrotherapy' and second one is 'in-vitro LIC stimulation of ADCSs' where role and significance of in-situ ADCSs were never studied.

Moderate Physical Training Ameliorates Cardiovascular Dysfunction Induced by High Fat Diet After Cessation of Training in Adult Rats

We aimed to test whether moderate physical training can induce long-lasting protection against cardiovascular risk factors induced by high fat diet (HFD) intake, even after cessation of training. 90-days-old Wistar rats were submitted to a sedentary lifestyle or moderate physical training, three times a week, for 30 days. Following this, at 120 days-of age, sedentary and trained rats received a hypercaloric diet (HFD) or a commercial diet normal fat diet (NFD) for 30 days. Body weight (BW) and food intake were evaluated weekly. At 150 days-of age, hemodynamic measures (systolic, diastolic, mean blood pressure, pulse pressure, pulse interval and heart rate) were made via an indwelling femoral artery catheter. Beat-to-beat data were analyzed to calculate power spectra of systolic blood pressure (SBP) and pulse interval. After euthanasia, mesenteric fat pads were removed and weighted and total blood was stored for later analysis of lipid profile. Consumption of a HFD increased blood pressure (BP), pulse pressure, low frequency BP variability, BW gain, fat pad stores and induced dyslipidemia. Interestingly, prior physical training was able to partially protect against this rise in BP and body fat stores. Prior physical training did not totally protect against the effects of HFD consumption but previously trained animals did demonstrate resistance to the development of cardiometabolic alterations, which illustrate that the benefits of physical training may be partially maintained even after 30 days of detraining period.

Effect of the Anti-Inflammatory Diet in People with Diabetes and Pre-Diabetes: A Randomized Controlled Feeding Study

Introduction

Inflammation underlies a variety of chronic medical conditions, including diabetes. The anti-inflammatory diet, one that excludes foods that may stimulate inflammation and includes foods that reduce inflammation, may improve inflammatory biomarkers in people with diabetes and pre-diabetes.

Study Design

Thirty participants with diabetes or pre-diabetes were randomized (2:1) in a controlled feeding study that compared the anti-inflammatory diet (n=20) to a control diet (n=10) based on the American Diabetes Association recommendations. Diets were matched for protein, carbohydrate, fat, and fiber content as closely as possible. Participants were fed an isocaloric diet for 2 weeks, followed by continued ad libitum feeding in their dietary group assignment for an additional 4 weeks. All meals were prepared by the study team.

Outcomes

Primary outcomes included inflammatory markers, including cytokines and hsCRP. Secondary outcomes included body weight and biomarkers for cardiovascular disease and diabetes.

Results

Both diets resulted in trends in reduced markers of inflammation, especially with weight loss. In addition, glucose, lipids, and triglycerides all trended downward, also non-significantly and equally in both groups.

Conclusion

Dietary change can improve inflammation as well as other cardiometabolic risk factors. In this study, the anti-inflammatory diet did not affect markers of inflammation more than the control diet.

Dietary Habits and Intestinal Immunity: From Food Intake to CD4+ T H Cells

Dietary habits have a profound impact on intestinal homeostasis and in general on human health. In Western countries, high intake of calories derived from fried products, butter and processed meat is favored over dietary regimens rich in fruits and vegetables. This type of diet is usually referred to as Western-type diet (WTD) and it has been associated with several metabolic and chronic inflammatory conditions of the gastrointestinal tract. In this review, we describe how WTD promotes intestinal and extra-intestinal inflammation and alters mucosal immunity acting on CD4⁺ T cells in a microbiota-dependent or –independent fashion, ultimately leading to higher susceptibility to infectious and autoimmune diseases. Moreover, summarizing recent findings, we propose how dietary supplementation with fiber and vitamins could be used as a tool to modulate CD4⁺ T cell phenotype and function, ameliorating inflammation and restoring mucosal homeostasis.

Association between enteral macronutrient delivery and inflammatory response in critically ill children

BACKGROUND AND AIMS

An important goal of nutrition support in paediatric critical illness is minimising catabolism. While focussing on providing full energy requirements, macronutrient balance is often neglected. Studies suggest that there is interplay between nutrition and inflammation. We aimed to assess the amount of enteral macronutrients delivered compared to estimated requirements, and the association between delivered macronutrients and systemic inflammation in critically ill children.

METHOD

We prospectively evaluated energy and macronutrient intake in critically ill children who required at least 72 h of mechanical ventilation. Data on enteral energy and macronutrient intake was collected and expressed as a percentage of the estimated requirements. Circulating levels of inflammatory cytokines were measured by ELISA and association assessed with delivery of macronutrients from the previous 24 h.

RESULTS

A total of 87 children (0-16 years) were included in this study. By day 3 the median (IQR) intake of energy, fat, carbohydrate (CHO) and protein were 75% (50-103), 85% (43-120), 63% (42-102) and 45% (23-65) respectively. We have also shown that delivery of enteral fat and protein was associated with elevation in the levels of tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6).

CONCLUSION

The inflammatory response in critically ill children is influenced by the amount of enteral fat and protein delivered. Our data suggests that within the feed delivered, fat is often higher than protein and CHO. It is crucial to take into account the proportion of macronutrients required and not only aim to achieve the energy goal.

Diet-induced glucose homeostasis dysregulation is enhanced by taurine supplementation in ovariectomized mice

Low levels of estrogens are associated with obesity-related comorbidities. Mice with lower levels of estrogens are thereby more sensitive to the effects of a high-fat-diet (HFD) for the development of glucose intolerance and insulin resistance. Studies in vivo have demonstrated that taurine (TAU) supplementation prevents glucose and insulin resistance. Thus, we aimed to investigate the potential beneficial effects of TAU supplementation on glucose homeostasis of mice with low levels of estrogens fed with a HFD. 3-month-old female C57BL/6J mice underwent bilateral ovariectomy (OVX). After 1 week of recovery, mice were divided into 4 groups and either received: a standard chow diet (OVXC), chow diet plus drinking water enriched with 3% of TAU (OVXCT), HFD (OVXH), and HFD plus supplementation of TAU (OVXHT) for 14 weeks. Exposure to the HFD increased adiposity and plasma levels of glucose and insulin. Contrary to our prediction, the addition of TAU enhanced the deleterious effects of the HFD. Glucose and insulin tolerance tests (ipGTT and ipITT) indicated that mice maintained on the HFD + TAU had worse glucose intolerance and insulin resistance that was linked to lower insulin signaling in skeletal muscle and liver. Insulin secretion of isolated pancreatic islets of OVXH mice was higher than OVXC, and the addition of TAU associated with a HFD did not modulate insulin secretion, suggesting a failure of pancreatic β cells of OVXHT mice. These results suggest that despite the beneficial reports of TAU, it should be used cautiously in situations where the levels of estrogens are low.

Anti-hyperglycemic and anti-hyperlipidaemic effect of Arjunarishta in high-fat fed animals

Background

Arjunarishta (AA), a formulation used as cardiotonic is a hydroalcoholic formulation of Terminalia arjuna (Roxb.) Wight and Arn. (TA) belonging to family Combretaceae.

Objective

To evaluate the anti-hyperglycemic and anti-hyperlipidemic effect of Arjunarishta on high-fat diet fed animals.

Materials and methods

High-fat diet fed (HFD) Wistar rats were randomly divided into three groups and treated with phytochemically standardized Arjunarishta (1.8 ml/kg), and hydroalcoholic extract of T. arjuna (TAHA) (250 mg/kg) and rosuvastatin (10 mg/kg), for 3 months. Intraperitoneal glucose tolerance test, blood biochemistry, liver triglyceride and systolic blood pressure were performed in all the groups. Effect of these drugs on the expression of tumor necrosis factor-α (TNF-α) and insulin receptor substrate-1 (IRS-1) and peroxisome proliferators activated receptor γ coactivator 1-α (PGC-1α) were studied in liver tissue using Quantitative Real-time PCR.

Results

HFD increased fasting blood glucose, liver triglyceride, systolic blood pressure and gene expression of TNF-α, IRS-1 and PGC-1α. Treatment of AA and TAHA significantly reduced fasting blood glucose, systolic blood pressure, total cholesterol and triglyceride levels. These treatments significantly decreased gene expression of TNF-α (2.4, 2.2 and 2.6 fold change); increased IRS-1 (2.8, 2.9 and 2.8 fold change) and PGC-1α (2.9, 3.7 and 3.3 fold change) as compared to untreated HFD.

Conclusion

Anti-hyperglycemic, anti-hyperlipidemic effect of Arjunarishta may be mediated by decreased TNF-α and increased PGC-1α and IRS-1.

Tumor necrosis factor alpha in sleep regulation

This review details tumor necrosis factor alpha (TNF) biology and its role in sleep, and describes how TNF medications influence sleep/wake activity. Substantial evidence from healthy young animals indicates acute enhancement or inhibition of endogenous brain TNF respectively promotes and inhibits sleep. In contrast, the role of TNF in sleep in most human studies involves pathological conditions associated with chronic elevations of systemic TNF and disrupted sleep. Normalization of TNF levels in such patients improves sleep. A few studies involving normal healthy humans and their TNF levels and sleep are consistent with the animal studies but are necessarily more limited in scope. TNF can act on established sleep regulatory circuits to promote sleep and on the cortex within small networks, such as cortical columns, to induce sleep-like states. TNF affects multiple synaptic functions, e.g., its role in synaptic scaling is firmly established. The TNF-plasticity actions, like its role in sleep, can be local network events suggesting that sleep and plasticity share biochemical regulatory mechanisms and thus may be inseparable from each other. We conclude that TNF is involved in sleep regulation acting within an extensive tightly orchestrated biochemical network to niche-adapt sleep in health and disease.

Long-lasting effect of obesity on skeletal muscle transcriptome

BACKGROUND

Reduced physical activity and increased intake of calorically-dense diets are the main risk factors for obesity, glucose intolerance, and type 2 diabetes. Chronic overnutrition and hyperglycemia can alter gene expression, contributing to long-term obesity complications. While caloric restriction can reduce obesity and glucose intolerance, it is currently unknown whether it can effectively reprogram transcriptome to a pre-obesity level. The present study addressed this question by the preliminary examination of the transcriptional dynamics in skeletal muscle after exposure to overnutrition and following caloric restriction.

RESULTS

Six male rhesus macaques of 12-13 years of age consumed a high-fat western-style diet for 6 months and then were calorically restricted for 4 months without exercise. Skeletal muscle biopsies were subjected to longitudinal gene expression analysis using next-generation whole-genome RNA sequencing. In spite of significant weight loss and normalized insulin sensitivity, the majority of WSD-induced (n = 457) and WSD-suppressed (n = 47) genes remained significantly dysregulated after caloric restriction (FDR ≤0.05). The Metacore^TM pathway analysis reveals that western-style diet induced the sustained activation of the transforming growth factor-β gene network, associated with extracellular matrix remodeling, and the downregulation of genes involved in muscle structure development and nutritional processes.

CONCLUSIONS

Western-style diet, in the absence of exercise, induced skeletal muscle transcriptional programing, which persisted even after insulin resistance and glucose intolerance were completely reversed with caloric restriction.

iNOS as a Driver of Inflammation and Apoptosis in Mouse Skeletal Muscle after Burn Injury: Possible Involvement of Sirt1 S-Nitrosylation-Mediated Acetylation of p65 NF-κB and p53

Inflammation and apoptosis develop in skeletal muscle after major trauma, including burn injury, and play a pivotal role in insulin resistance and muscle wasting. We and others have shown that inducible nitric oxide synthase (iNOS), a major mediator of inflammation, plays an important role in stress (e.g., burn)-induced insulin resistance. However, it remains to be determined how iNOS induces insulin resistance. Moreover, the interrelation between inflammatory response and apoptosis is poorly understood, although they often develop simultaneously. Nuclear factor (NF)-κB and p53 are key regulators of inflammation and apoptosis, respectively. Sirt1 inhibits p65 NF-κB and p53 by deacetylating these transcription factors. Recently, we have shown that iNOS induces S-nitrosylation of Sirt1, which inactivates Sirt1 and thereby increases acetylation and activity of p65 NF-κB and p53 in various cell types, including skeletal muscle cells. Here, we show that iNOS enhances burn-induced inflammatory response and apoptotic change in mouse skeletal muscle along with S-nitrosylation of Sirt1. Burn injury induced robust expression of iNOS in skeletal muscle and gene disruption of iNOS significantly inhibited burn-induced increases in inflammatory gene expression and apoptotic change. In parallel, burn increased Sirt1 S-nitrosylation and acetylation and DNA-binding capacity of p65 NF-κB and p53, all of which were reversed or ameliorated by iNOS deficiency. These results indicate that iNOS functions not only as a downstream effector but also as an upstream enhancer of burn-induced inflammatory response, at least in part, by Sirt1 S-nitrosylation-dependent activation (acetylation) of p65 NF-κB. Our data suggest that Sirt1 S-nitrosylation may play a role in iNOS-mediated enhanced inflammatory response and apoptotic change, which, in turn, contribute to muscle wasting and supposedly to insulin resistance after burn injury.

Imidacloprid Promotes High Fat Diet-Induced Adiposity and Insulin Resistance in Male C57BL/6J Mice

Imidacloprid, a neonicotinoid insecticide widely used in agriculture worldwide, has been reported to promote adipogenesis and cause insulin resistance in vitro. The purpose of the current study was to determine the effects of imidacloprid and its interaction with dietary fat in the development of adiposity and insulin resistance using male C57BL/6J mice. Imidacloprid (0.06, 0.6, or 6 mg/kg bw/day) was mixed in a low-fat (4% w/w) or high-fat (20% w/w) diet and given to mice ad libitum for 12 weeks. Imidacloprid significantly promoted high fat diet-induced body weight gain and adiposity. In addition, imidacloprid treatment with the high fat diet resulted in impaired glucose metabolism. Consistently, there were significant effects of imidacloprid on genes regulating lipid and glucose metabolisms, including the AMP-activated protein kinase-α (AMPKα) pathway in white adipose tissue and liver. These results suggest that imidacloprid may potentiate high fat diet-induced adiposity and insulin resistance in male C57BL/6J mice.

Zingiber mioga reduces weight gain, insulin resistance and hepatic gluconeogenesis in diet-induced obese mice

Zingiber mioga is a perennial herb belonging to the ginger family (Zingiberaceae) that is used medicinally to treat cough and rheumatism in China and consumed throughout Japan. The aim of the present study was to investigate the anti-obesity effects of Z. mioga following extraction with distilled water or 70% ethanol. In 3T3-L1 preadipocyte cells, Z. mioga water extract (ZMW) markedly inhibited adipogenesis, whereas the ethanol extract had no effect. In addition, we conducted ZMW feeding experiments (0.25 or 0.5% ZMW) in high-fat diet (HFD)-fed mice to examine the anti-obesity effects of Z. mioga in vivo. Body weight and serum triglyceride and cholesterol levels significantly decreased in the HFD + ZMW 0.5% group. Notably, ZMW decreased liver weight but not adipose tissue weight. Furthermore, insulin resistance and hepatic mRNA expression of gluconeogenic genes, such as phosphoenolpyruvate carboxykinase and G6Pase, were improved in the HFD + ZMW 0.5% group. Furthermore, ZMW treatment decreased hepatic lipogenic gene expression; however, it did not alter adipogenesis in fat tissue, suggesting that ZMW inhibits hepatosteatosis through the suppression of lipogenesis. ZMW improved HFD-induced hepatic inflammation. Collectively, the present findings suggest that ZMW may serve as a new and promising strategy for the treatment of hepatosteatosis.

Bifidobacterium pseudocatenulatum CECT 7765 Reduces Obesity-Associated Inflammation by Restoring the Lymphocyte-Macrophage Balance and Gut Microbiota Structure in High-Fat Diet-Fed Mice

BACKGROUND/OBJECTIVES

The role of intestinal dysbiosis in obesity-associated systemic inflammation via the cross-talk with peripheral tissues is under debate. Our objective was to decipher the mechanisms by which intervention in the gut ecosystem with a specific Bifidobacterium strain reduces systemic inflammation and improves metabolic dysfunction in obese high-fat diet (HFD) fed mice.

METHODS

Adult male wild-type C57BL-6 mice were fed either a standard or HFD, supplemented with placebo or Bifidobacterium pseudocatenulatum CECT 7765, for 14 weeks. Lymphocytes, macrophages and cytokine/chemokine concentrations were quantified in blood, gut, liver and adipose tissue using bead-based multiplex assays. Biochemical parameters in serum were determined by ELISA and enzymatic assays. Histology was assessed by hematoxylin-eosin staining. Microbiota was analyzed by 16S rRNA gene pyrosequencing and quantitative PCR.

RESULTS

B. pseudocatenulatum CECT 7765 reduced obesity-associated systemic inflammation by restoring the balance between regulatory T cells (Tregs) and B lymphocytes and reducing pro-inflammatory cytokines of adaptive (IL-17A) and innate (TNF-α) immunity and endotoxemia. In the gut, the bifidobacterial administration partially restored the HFD-induced alterations in microbiota, reducing abundances of Firmicutes and of LPS-producing Proteobacteria, paralleled to reductions in B cells, macrophages, and cytokines (IL-6, MCP-1, TNF-α, IL-17A), which could contribute to systemic effects. In adipose tissue, bifidobacterial administration reduced B cells whereas in liver the treatment increased Tregs and shifted different cytokines (MCP-1 plus ILP-10 in adipose tissue and INF-γ plus IL-1β in liver). In both tissues, the bifidobacteria reduced pro-inflammatory macrophages and, TNF-α and IL-17A concentrations. These effects were accompanied by reductions in body weight gain and in serum cholesterol, triglyceride, glucose and insulin levels and improved oral glucose tolerance and insulin sensitivity in obese mice.

CONCLUSIONS

Here, we provide evidence of the immune cellular mechanisms by which the inflammatory cascade associated with diet-induced obesity is attenuated by the administration of a specific Bifidobacterium strain and that these effects are associated with modulation of gut microbiota structure.

Short-Term High Fat Intake Does Not Significantly Alter Markers of Renal Function or Inflammation in Young Male Sprague-Dawley Rats

Chronic high fat feeding is correlated with diabetes and kidney disease. However, the impact of short-term high fat diets (HFD) is not well-understood. Six weeks of HFD result in indices of metabolic syndrome (increased adiposity, hyperglycemia, hyperinsulinemia, hyperlipidemia, hyperleptinemia, and impaired endothelium-dependent vasodilation) compared to rats fed on standard chow. The hypothesis was that short-term HFD would induce early signs of renal disease. Young male Sprague-Dawley rats were fed either HFD (60% fat) or standard chow (5% fat) for six weeks. Morphology was determined by measuring changes in renal mass and microstructure. Kidney function was measured by analyzing urinary protein, creatinine, and hydrogen peroxide (H₂O₂) concentrations, as well as plasma cystatin C concentrations. Renal damage was measured through assessment of urinary oxDNA/RNA concentrations as well as renal lipid peroxidation, tumor necrosis factor alpha (TNFα), and interleukin 6 (IL-6). Despite HFD significantly increasing adiposity and renal mass, there was no evidence of early stage kidney disease as measured by changes in urinary and plasma biomarkers as well as histology. These findings suggest that moderate hyperglycemia and inflammation produced by short-term HFD are not sufficient to damage kidneys or that the ketogenic HFD may have protective effects within the kidneys.

Moderate exercise training is more effective than resveratrol supplementation for ameliorating lipid metabolic complication in skeletal muscle of high fat diet-induced obese mice

PURPOSE

The aim of this study was to compare the effectiveness of moderate exercise training or resveratrol supplementation with a low fat diet on lipid metabolism in the skeletal muscle of high fat diet-induced obese mice.

METHODS

C57BL/6J mice (5 weeks old, n = 30) were fed a high fat diet (45% fat) for 8 weeks first to make them obese. Afterward, all the mice were fed a low fat diet during 8 weeks of intervention with moderate exercise training and resveratrol supplementation. Before the intervention, the mice were separated into 3 groups: low-fat diet control (HLC; n = 10), low fat diet with resveratrol (HLR; n = 10) or low fat diet with exercise (HLE n = 10). The exercise group (HLE) performed treadmill running for 30-60 min/day at 10-22 m/min, 0% grade, 5 times/week for 8 weeks, while the resveratrol group (HLR) received a daily dose of resveratrol (10 mg/kg of body weight), 5 days/week for 8 weeks.

RESULTS

Body weight was significantly reduced in HLE. Further, the lipogenesis marker SREBP and the inflammatory cytokine TNF-α were significant reduced in HLE. However, there was no significant effect from resveratrol supplementation with a low fat diet. Taken together, exercise training with a low fat diet has the positive effect of ameliorating lipid disturbance in the skeletal muscle of high fat diet-induced obese mice.

CONCLUSION

These findings suggest that exercise training with a low fat diet is most effective to improve lipid metabolism by reducing lipogenesis and inflammation in the skeletal muscle of high fat diet-induced obese mice.

Muscular interleukin-6 differentially regulates skeletal muscle adaptation to high-fat diet in a sex-dependent manner

Interleukin-6 (IL-6) is now known to be not only a major cytokine controlling the immune system but also basic physiological variables such as body weight and metabolism. We recently reported that muscle-specific interleukin-6 deletion influences body weight and body fat in a sex-dependent manner in mice. When compared with littermate floxed controls, males gained less weight whereas females gained more weight after a 12-week high-fat diet treatment (HFD). We herewith report gender-differences of HFD treatment on fast and slow skeletal muscle in muscle-specific IL-6 deficient mice. While gross muscle architecture was normal, in males, HFD resulted in an increased proportion of medium-large size myofibers which was prevented by muscle IL-6 deletion. No modifications of fiber size were observed in females. HFD induced a fiber-type switching in tibialis muscle, increasing the proportion of fast-oxidative fibers and decreasing the fast-glycolytic fibers in female mice which were dependent on muscle IL-6. No changes of fiber types were detected in males. Finally, HFD was associated with increased collagen deposition in both sexes and muscle types. However, this effect was only associated to the presence of muscular IL-6 only on the slow soleus muscle in males. The results demonstrate sex-dependent effects of both HFD and muscle IL-6 deficiency in skeletal muscle.

Efficacy of garcinia cambogia on body weight, inflammation and glucose tolerance in high fat fed male wistar rats

INTRODUCTION

Obesity leads to derangements in lipid and glucose homeostasis resulting in various metabolic complications. Plants containing vital phytochemicals are known to posses anti obesity properties and have proved to exert beneficial effects in obesity.

OBJECTIVES

The present study was aimed to investigate the effects of Garcinia Cambogia on body weight, glucose tolerance and inflammation in high fat diet fed male Wistar rats.

MATERIALS AND METHODS

Five month old male wistar rats (n=40) were divided into four groups. Two groups were fed with standard rodent diet and the remaining two with 30% high fat diet. One group in each of the two sets received the crude ethanolic extract of Garcinia Cambogia at a dose of 400mg/kg body weight/day for ten weeks. Body weight, intraperitoneal glucose tolerance test, leptin, tumour necrosis factor-α (TNF-α) and renal function (urea, creatinine, uric acid) were studied.

RESULTS

High fat diet fed rats showed increased body weight gain, glucose intolerance, elevated levels of plasma leptin and TNF-α. Supplementation of Garcinia Cambogia extract (GE) along with high fat diet significantly decreased body weight gain, glucose intolerance, plasma leptin and TNF-α level. No significant changes were observed in the renal function parameters in any of the groups.

CONCLUSION

Supplementation of the Garcinia Cambogia extract with high fat diet reduced body weight gain, inflammation and glucose intolerance.

Vagus nerve contributes to metabolic syndrome in high-fat diet-fed young and adult rats

NEW FINDINGS

What is the central question of this study? Different nerve contributes periods of life are known for their differential sensitivity to interventions, and increased parasympathetic activity affects the development and maintenance of obesity. Thus, we evaluated the involvement of the vagus nerve by performing a vagotomy in young or adult rats that were offered an obesogenic high-fat diet. What is the main finding and its importance? Although the accumulation of adipose tissue decreased in both younger and older groups, the younger rats showed a greater response to the effects of vagotomy in general. In addition to the important role of the parasympathetic activity, we suggest that the vagus nerve contributes to the condition of obesity. Obesity has become a global problem, and this condition develops primarily because of an imbalance between energy intake and expenditure. The high complexity involved in the regulation of energy metabolism results from several factors besides endocrine factors. It has been suggested that obesity could be caused by an imbalance in the autonomous nervous system, which could lead to a condition of high parasympathetic activity in counterpart to low sympathetic tonus. High-fat (HF) diets have been used to induce obesity in experimental animals, and their use in animals leads to insulin resistance, hyperinsulinaemia and high parasympathetic activity, among other disorders. The aim of this work was to evaluate the effects of a vagotomy performed at the initiation of a HF diet at two different stages of life, weaning and adulthood. The vagotomy reduced parasympathetic activity (-32 and -51% in normal fat-fed rats and -43 and -55% in HF diet-fed rats; P < 0.05) and fat depots (-17 and -33%, only in HF diet-fed rats; P < 0.05). High-fat diet-fed rats exhibited fasting hyperinsulinaemia (fivefold higher in young rats and threefold higher in older rats; P < 0.05); however, vagotomy corrected it in younger rats only, and a similar effect was also observed during the glucose tolerance test. The insulin resistance exhibited by the HF diet-fed groups was not altered in the vagotomized rats. We suggest that the vagus nerve, in addition to the important role of parasympathetic activity, contributes to the condition of obesity, and that non-vagal pathways may be involved along with the imbalanced autonomic nervous system.

LPS-induced inflammation in the chicken is associated with CCAAT/enhancer binding protein beta-mediated fat mass and obesity associated gene down-regulation in the liver but not hypothalamus

Background

The fat mass and obesity associated gene (FTO) is widely investigated in humans regarding its important roles in obesity and type 2 diabetes. Studies in mammals demonstrate that FTO is also associated with inflammation markers. However, the association of FTO with inflammation in chickens remains unclear. In this study, male chickens on day 28 posthatching were injected intraperitoneally with lipopolysaccharide (LPS) or saline to investigate whether the FTO gene is involved in LPS-induced inflammation.

Results

We detected significant down-regulation of FTO mRNA in the liver (P < 0.01), but not in the hypothalamus, 2 and 24 h after LPS challenge. Toll-like receptor (TLR) 2 (P < 0.01) and TLR4 (P < 0.01) followed the same pattern as FTO, being suppressed significantly in liver but not in hypothalamus. IL-1β was dramatically up-regulated (P < 0.01) in both liver and hypothalamus 2 h after LPS challenge, while activation of IL-6 was observed in the liver (P < 0.01), but not in hypothalamus. The 5′-flanking sequence of the chicken FTO gene contains nine predicted binding sites for CCAAT/enhancer binding protein beta (C/EBP beta) and one for signal transducer and activator of transcription 3 (STAT3). Significant elevation of C/EBP beta was detected in the liver (P < 0.01), but not in the hypothalamus, 2 h after LPS challenge. Lipopolysaccharide challenge increased the C/EBP beta binding to FTO promoter in the liver (P < 0.01 for fragment 1, P < 0.05 for fragment 2), although the protein content of C/EBP beta was not altered. Moreover, injection of LPS resulted in enhanced phosphorylation of liver STAT3, a downstream transcription factor in IL-6 signaling. Although phosphorylated STAT3 was not detected to directly bind to FTO promoter, it was found to interact with C/EBP beta.

Conclusion

Our results reveal that FTO expression in liver, but not in hypothalamus, is affected by the i.p. injection of LPS, which may be mediated through tissue-specific FTO transcriptional regulation by C/EBP beta and STAT3 interaction.

The mechanisms linking adiposopathy to type 2 diabetes

Obesity is defined as excessive accumulation of body fat in proportion to body size. When obesity occurs, the functions of adipose tissue may be deregulated, which is termed as adiposopathy. Adiposopathy is an independent risk factor for many diseases, including diabetes and cardiovascular diseases. In overweight or obese subjects with adiposopathy, hyperlipidemia exerts lipotoxicity in pancreatic islet and liver and induces pancreatic β cell dysfunction and liver insulin resistance, which are the decisive factors causing type 2 diabetes. Moreover, adipokines have been shown to play important roles in the regulation of glucose homeostasis. When adiposopathy occurs, abnormal changes in the serum adipokine profile correlate with the development and progression of pancreatic β cell dysfunction and insulin resistance in peripheral tissue. The current paper briefly discusses the latest findings regarding the effects of adiposopathy-related lipotoxicity and cytokine toxicity on the development of type 2 diabetes.

Impaired protein metabolism: interlinks between obesity, insulin resistance and inflammation

Metabolic and structural changes in skeletal muscle that accompany obesity are often associated with the development of insulin resistance. The first events in the pathogenesis of this disorder are considered as an accumulation of lipids within skeletal muscle due to blunted muscle capacity to oxidize fatty acids. Fat infiltration is also associated with muscle fibre typology modification, decrease in muscle mass and impairments in muscle strength. Thus, as a result of obesity, mobility and quality of life are affected, and this is in part due to quantitative and qualitative impairments in skeletal muscle. In addition, the insulin resistance related to obesity results not only in defective insulin-stimulated glucose disposal but has also detrimental consequences on protein metabolism at the skeletal muscle level and whole-body level. This review highlights the involvement of fat accumulation and insulin resistance in metabolic disorders occurring in skeletal muscle during the development of obesity, and the impairments in the regulation of protein metabolism and protein turnover in the links between obesity, metabolic inflammation and insulin resistance.

Time-course changes of muscle protein synthesis associated with obesity-induced lipotoxicity

The object of the study was to investigate the sequential changes of protein synthesis in skeletal muscle during establishment of obesity, considering muscle typology. Adult Wistar rats were fed a standard diet for 16 weeks (C; n = 14), or a high-fat, high-sucrose diet for 16 (HF16; n = 14) or 24 weeks (HF24; n = 15). Body composition was measured using a dual-energy X-ray absorptiometry scanner. The fractional synthesis rates (FSRs) of muscle protein fractions were calculated in tibialis anterior (TA) and soleus muscles by incorporation of l-13C-valine in muscle protein. Muscle lipid and mitochondria contents were determined using histochemical analysis. Obesity occurred in an initial phase, from 1 to 16 weeks, with an increase in weight (P < 0.05), fat mass (P < 0.001), muscle mass (P < 0.001) and FSR in TA (actin: 5.3 ± 0.2 vs. 8.8 ± 0.5% day−1, C vs. HF16, P < 0.001) compared with standard diet. The second phase, from 16 to 24 weeks, was associated with a weight stabilization, a decrease in muscle mass (P < 0.05) and a decrease in FSR in TA (mitochondrial: 5.6 ± 0.2 vs. 4.2 ± 0.4% day−1, HF16 vs. HF24, P < 0.01) compared with HF16 group. Muscle lipid content was increased in TA in the second phase of obesity development (P < 0.001). Muscle mass, lipid infiltration and muscle protein synthesis were differently affected, depending on the stage of obesity development and muscle typology. Chronic lipid infiltration in glycolytic muscle is concomitant with a reduction of muscle protein synthesis, suggesting that muscle lipid infiltration in response to a high-fat diet is deleterious for the incorporation of amino acid in skeletal muscle proteins.

Quercetin decreases inflammatory response and increases insulin action in skeletal muscle of ob/ob mice and in L6 myotubes

Quercetin is a potent anti-inflammatory flavonoid, but its capacity to modulate insulin sensitivity in obese insulin resistant conditions is unknown. This study investigated the effect of quercetin treatment upon insulin sensitivity of ob/ob mice and its potential molecular mechanisms. Obese ob/ob mice were treated with quercetin for 10 weeks, and L6 myotubes were treated with either palmitate or tumor necrosis factor-α (TNFα) plus quercetin. Cells and muscles were processed for analysis of glucose transporter 4 (GLUT4), TNFα and inducible nitric oxide synthase (iNOS) expression, and c-Jun N-terminal kinase (JNK) and inhibitor of nuclear factor-κB (NF-κB) kinase (IκK) phosphorylation. Myotubes were assayed for glucose uptake and NF-κB translocation. Chromatin immunoprecipitation assessed NF-κB binding to GLUT4 promoter. Quercetin treatment improved whole body insulin sensitivity by increasing GLUT4 expression and decreasing JNK phosphorylation, and TNFα and iNOS expression in skeletal muscle. Quercetin suppressed palmitate-induced upregulation of TNFα and iNOS and restored normal levels of GLUT4 in myotubes. In parallel, quercetin suppressed TNFα-induced reduction of glucose uptake in myotubes. Nuclear accumulation of NF-κB in myotubes and binding of NF-κB to GLUT4 promoter in muscles of ob/ob mice were also reduced by quercetin. We demonstrated that quercetin decreased the inflammatory status in skeletal muscle of obese mice and in L6 myotubes. This effect was followed by increased muscle GLUT4, with parallel improvement of insulin sensitivity. These results point out quercetin as a putative strategy to manage inflammatory-related insulin resistance.

Involvement of nuclear factor kappa B in high-fat diet-related pancreatic fibrosis in rats

Background/Aims

High-fat diets contribute to pancreatic fibrogenesis, but the pathogenesis remains unclear. This study investigated the role of nuclear factor kappa B (NF-κB) in high-fat diet-induced pancreatic fibrosis in rats.

Methods

Male Wistar rats were fed a high-fat diet or standard normal chow for 20 weeks. Pancreatic fibrosis was determined by Sirius red staining. Immunohistochemical staining, reverse transcription-polymerase chain reaction and Western blotting were used to identify NF-κB-associated genes or protein expressions.

Results

Inflammation, fat deposition, pancreatic stellate cell activation and fibrosis were observed in the pancreases of the high-fat diet group. NF-κB subunit p65 (NF-κB/p65) expression was localized to the nucleus, and intercellular adhesion molecule 1 (ICAM-1) was over-expressed. Pancreatic gene expression levels of NF-κB/p65, ICAM-1 and tumor necrosis factor α were all elevated significantly in rats fed a high-fat diet compared with control rats. Western blotting also revealed significantly increased levels of ICAM-1 and nuclear NF-κB/p65 in rats fed high-fat diets comparison with control rats.

Conclusions

NF-κB is involved in high-fat diet-related pancreatic fibrosis.

Gut Microbiota and Obesity

The current obesity epidemic clearly has many causes, including the impact of our modern world on both our diet and our lifestyle/physical activity. Although many interventions have been recommended, the prevalence of obesity continues to rise and has forced a re-evaluation of the potential interventions that could have an impact. In recent years it has been definitively shown that microbiota in the gastrointestinal tract are altered in obese individuals. Recent data provide a potential mechanistic understanding of the interactions between microbiota and obesity and allow potential new interventions to the control of obesity to be proposed.

Amyloid precursor protein and proinflammatory changes are regulated in brain and adipose tissue in a murine model of high fat diet-induced obesity

Background

Middle age obesity is recognized as a risk factor for Alzheimer's disease (AD) although a mechanistic linkage remains unclear. Based upon the fact that obese adipose tissue and AD brains are both areas of proinflammatory change, a possible common event is chronic inflammation. Since an autosomal dominant form of AD is associated with mutations in the gene coding for the ubiquitously expressed transmembrane protein, amyloid precursor protein (APP) and recent evidence demonstrates increased APP levels in adipose tissue during obesity it is feasible that APP serves some function in both disease conditions.

Methodology/Principal Findings

To determine whether diet-induced obesity produced proinflammatory changes and altered APP expression in brain versus adipose tissue, 6 week old C57BL6/J mice were maintained on a control or high fat diet for 22 weeks. Protein levels and cell-specific APP expression along with markers of inflammation and immune cell activation were compared between hippocampus, abdominal subcutaneous fat and visceral pericardial fat. APP stimulation-dependent changes in macrophage and adipocyte culture phenotype were examined for comparison to the in vivo changes.

Conclusions/Significance

Adipose tissue and brain from high fat diet fed animals demonstrated increased TNF-α and microglial and macrophage activation. Both brains and adipose tissue also had elevated APP levels localizing to neurons and macrophage/adipocytes, respectively. APP agonist antibody stimulation of macrophage cultures increased specific cytokine secretion with no obvious effects on adipocyte culture phenotype. These data support the hypothesis that high fat diet-dependent obesity results in concomitant pro-inflammatory changes in brain and adipose tissue that is characterized, in part, by increased levels of APP that may be contributing specifically to inflammatory changes that occur.

Immunomodulatory actions of central ghrelin in diet-induced energy imbalance

We investigated the effects of centrally administered orexigenic hormone ghrelin on energy imbalance-induced inflammation. Rats were subjected for four weeks to three different dietary regimes: normal (standard food), high-fat (standard food with 30% lard) or food-restricted (70%, 50%, 40% and 40% of the expected food intake in 1st, 2nd, 3rd and 4th week, respectively). Compared to normal-weight controls, starved, but not obese rats had significantly higher levels of proinflammatory cytokines (TNF, IL-1β, IFN-γ) in the blood. When compared to normally fed animals, the hearts of starved and obese animals expressed higher levels of mRNAs encoding proinflammatory mediators (TNF, IL-1β, IL-6, IFN-γ, IL-17, IL-12, iNOS), while mRNA levels of the anti-inflammatory TGF-β remained unchanged. Intracerebroventricular (ICV) injection of ghrelin (1 μg/day) for five consecutive days significantly reduced TNF, IL-1β and IFN-γ levels in the blood of starved rats, as well as TNF, IL-17 and IL-12p40 mRNA expression in the hearts of obese rats. Conversely, ICV ghrelin increased the levels of IFN-γ, IL-17, IL-12p35 and IL-12p40 mRNA in the heart tissue of food-restricted animals. This was associated with an increase of immunosuppressive ACTH/corticosterone production in starved animals and a decrease of the immunostimulatory adipokine leptin both in food-restricted and high-fat groups. Ghrelin activated the energy sensor AMP-activated protein kinase (AMPK) in the hypothalamus and inhibited extracellular signal-regulated kinase (ERK) in the hearts of obese, but not starved rats. Therefore, central ghrelin may play a complex role in energy imbalance-induced inflammation by modulating HPA axis, leptin and AMPK/ERK signaling pathways.

Both obesity-prone and obesity-resistant rats present delayed cutaneous wound healing

Diet-induced overweight rats exhibit delayed cutaneous healing; however, when receiving an obesogenic diet, some rats are susceptible to developing the overweight phenotype, whereas others are resistant. We investigated cutaneous healing in diet-induced obesity (DIO)-prone and diet-resistant (DR) rats. Male rats were fed with a standard (control) or a high-saturated fat (30 % fat, w/w) diet for 20 weeks. Then, the experimental group was subdivided into DIO (n 17) and DR (n 16) groups. An excision lesion was made, and the animals were killed 7 or 14 d later. The average body weight was 29 and 25 % higher in the DIO group compared with the C and DR groups. Retroperitoneal fat was higher in the DIO group than in the control and DR groups (518 and 92 %) and was higher in the DR group than in the control group (223 %). The DIO group presented glucose intolerance, and both the DIO and DR groups presented delayed wound contraction (50 %) and re-epithelialisation (20 %). Compared with the DR group, the DIO group displayed higher amounts of inflammatory cells as well as higher levels of lipid peroxidation (P < 0·05). Myofibroblastic differentiation and vessel remodelling were delayed in both the DIO and DR groups. Nitrite levels were lower in the DIO group (340 % less) than in the DR group. TNF-α expression was increased in the DIO group (130 %) compared with the DR group. Our results showed that DIO as well as DR rats present delays in cutaneous wound healing, even though the DR group does not have an overweight phenotype.

Cardiac remodeling in a rat model of diet-induced obesity

The mechanisms by which diet-induced obesity cause remodeling and cardiac dysfunction are still unknown. Interstitial collagen and myocardial ultrastructure are important in the development of left ventricular hypertrophy, and are essential to the adaptive and maladaptive changes associated with obesity. Thus, the accumulation of collagen and ultrastructural damage may contribute to cardiac dysfunction in obesity. The purpose of the present study was to investigate cardiac function in a rat model of diet-induced obesity and to test the hypothesis that cardiac dysfunction induced by obesity is related to myocardial collagen deposition and ultrastructural damage. Thirty-day-old male Wistar rats were fed standard (control [C]) and hypercaloric diets (obese [Ob]) for 15 weeks. Cardiac function was evaluated by echocardiogram and isolated left ventricle papillary muscle. Cardiac morphology was assessed by histology and electron microscopy. Compared with C rats, Ob rats had increased body fat, systolic blood pressure and area under the curve for glucose, leptin and insulin plasma concentrations. Echocardiographic indexes indicated that Ob rats had increased left ventricular mass, increased systolic stress and depressed systolic function. Analysis of the isolated papillary muscle was consistent with higher myocardial stiffness in Ob compared with C rats. The Ob rats had an increase in myocardial collagen and marked ultrastructural changes compared with C rats. Obesity promotes pathological cardiac remodeling with systolic dysfunction and an increase in myocardial stiffness, which, in turn, is probably related to afterload elevation and cardiac fibrosis. Obesity also causes damage to myocardial ultrastructure, but its effect on myocardial function needs to be further clarified.

Antioxidant effects of the chestnut (Castanea crenata) inner shell extract in t-BHP-treated HepG2 cells, and CCl4- and high-fat diet-treated mice

The antioxidant effects of chestnut inner shell extract (CISE) were investigated in a tert-butylhydroperoxide (t-BHP)-treated HepG2 cells, and in mice that were administered carbon tetrachloride (CCl(4)) and fed a high-fat diet (HFD). Pre-incubation with CISE significantly blocked the oxidative stress induced by t-BHP treatment in HepG2 cells (P<0.05) and preserved the activities of catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase compared to group treated with t-BHP only. Similarly, the CCl(4)- and HFD-induced reduction of antioxidant enzymes activities in liver was prevented by CISE treatment compared to control groups. Furthermore, hepatic lipid peroxidation were remarkably lower (P<0.05) in the CISE-treated groups with t-BHP or HFD. To determine the active compound of CISE, the fractionation of CISE has been conducted and scoparone and scopoletin were identified as main compounds. These compounds were also shown to inhibit the t-BHP-induced ROS generation and reduction in antioxidant enzyme activity in an in vitro model system. From these results, it was demonstrated that CISE has the ability to protect against damage from oxidative stressors such as t-BHP, CCl(4) and HFD in in vitro and in vivo models. The CISE might be useful for the prevention of oxidative damage in liver cells and tissues.