Inhibition of Crif1 protects fatty acid-induced POMC neuron-like cell-line damage by increasing CPT-1 function.

Hypothalamic proopiomelanocortin (POMC) neurons are sensors of signals that reflect the energy stored in the body. Inducing mild stress in proopiomelanocortin neurons protects them from the damage promoted by the consumption of a high-fat diet, mitigating the development of obesity; however, the cellular mechanisms behind these effects are unknown. Here, we induced mild stress in a proopiomelanocortin neuron cell line by inhibiting Crif1. In proopiomelanocortin neurons exposed to high levels of palmitate, the partial inhibition of Crif1 reverted the defects in mitochondrial respiration and ATP production; this was accompanied by improved mitochondrial fusion/fission cycling. Furthermore, the partial inhibition of Crif1 resulted in increased reactive oxygen species production, increased fatty acid oxidation, and reduced dependency on glucose for mitochondrial respiration. These changes were dependent on the activity of CPT-1. Thus, we identified a CPT-1-dependent metabolic shift toward greater utilization of fatty acids as substrates for respiration as the mechanism behind the protective effect of mild stress against palmitate-induced damage of proopiomelanocortin neurons.NEW & NOTEWORTHY Saturated fats can damage hypothalamic neurons resulting in positive energy balance, and this is mitigated by mild cellular stress; however, the mechanisms behind this protective effect are unknown. Using a proopiomelanocortin cell line, we show that under exposure to a high concentration of palmitate, the partial inhibition of the mitochondrial protein Crif1 results in protection due to a metabolic shift warranted by the increased expression and activity of the mitochondrial fatty acid transporter CPT-1.

Maternal obesity damages the median eminence blood-brain barrier structure and function in the progeny: the beneficial impact of cross-fostering by lean mothers.

Maternal obesity is an important risk factor for obesity, cardiovascular, and metabolic diseases in the offspring. Studies have shown that it leads to hypothalamic inflammation in the progeny, affecting the function of neurons regulating food intake and energy expenditure. In adult mice fed a high-fat diet, one of the hypothalamic abnormalities that contribute to the development of obesity is the damage of the blood-brain barrier (BBB) at the median eminence-arcuate nucleus (ME-ARC) interface; however, how the hypothalamic BBB is affected in the offspring of obese mothers requires further investigation. Here, we used confocal and transmission electron microscopy, transcript expression analysis, glucose tolerance testing, and a cross-fostering intervention to determine the impact of maternal obesity and breastfeeding on BBB integrity at the ME-ARC interface. The offspring of obese mothers were born smaller; conversely, at weaning, they presented larger body mass and glucose intolerance. In addition, maternal obesity-induced structural and functional damage of the offspring's ME-ARC BBB. By a cross-fostering intervention, some of the defects in barrier integrity and metabolism seen during development in an obesogenic diet were recovered. The offspring of obese dams breastfed by lean dams presented a reduction of body mass and glucose intolerance as compared to the offspring continuously exposed to an obesogenic environment during intrauterine and perinatal life; this was accompanied by partial recovery of the anatomical structure of the ME-ARC interface, and by the normalization of transcript expression of genes coding for hypothalamic neurotransmitters involved in energy balance and BBB integrity. Thus, maternal obesity promotes structural and functional damage of the hypothalamic BBB, which is, in part, reverted by lactation by lean mothers.NEW & NOTEWORTHY Maternal dietary habits directly influence offspring health. In this study, we aimed at determining the impact of maternal obesity on BBB integrity. We show that DIO offspring presented a leakier ME-BBB, accompanied by changes in the expression of transcripts encoding for endothelial and tanycytic proteins, as well as of hypothalamic neuropeptides. Breastfeeding in lean dams was sufficient to protect the offspring from ME-BBB disruption, providing a preventive strategy of nutritional intervention during early life.

Exogenous succinate impacts mouse brown adipose tissue mitochondrial proteome and potentiates body mass reduction induced by liraglutide.

Obesity is one of the leading noncommunicable diseases in the world. Despite intense efforts to develop strategies to prevent and treat obesity, its prevalence continues to rise worldwide. A recent study has shown that the tricarboxylic acid intermediate succinate increases body energy expenditure by promoting brown adipose tissue thermogenesis through the activation of uncoupling protein-1; this has generated interest surrounding its potential usefulness as an approach to treat obesity. It is currently unknown how succinate impacts brown adipose tissue protein expression, and how exogenous succinate impacts body mass reduction promoted by a drug approved to treat human obesity, the glucagon-like-1 receptor agonist, liraglutide. In the first part of this study, we used bottom-up shotgun proteomics to determine the acute impact of exogenous succinate on the brown adipose tissue. We show that succinate rapidly affects the expression of 177 brown adipose tissue proteins, which are mostly associated with mitochondrial structure and function. In the second part of this study, we performed a short-term preclinical pharmacological intervention, treating diet-induced obese mice with a combination of exogenous succinate and liraglutide. We show that the combination was more efficient than liraglutide alone in promoting body mass reduction, food energy efficiency reduction, food intake reduction, and an increase in body temperature. Using serum metabolomics analysis, we showed that succinate, but not liraglutide, promoted a significant increase in the blood levels of several medium and long-chain fatty acids. In conclusion, exogenous succinate promotes rapid changes in brown adipose tissue mitochondrial proteins, and when used in association with liraglutide, increases body mass reduction.NEW & NOTEWORTHY Exogenous succinate induces major changes in brown adipose tissue protein expression affecting particularly mitochondrial respiration and structural proteins. When given exogenously in drinking water, succinate mitigates body mass gain in a rodent model of diet-induced obesity; in addition, when given in association with the glucagon-like peptide-1 receptor agonist, liraglutide, succinate increases body mass reduction promoted by liraglutide alone.

Arcuate Nucleus Overexpression of NHLH2 Reduces Body Mass and Attenuates Obesity-Associated Anxiety/Depression-like Behavior.

Nescient helix-loop-helix 2 (NHLH2) is a hypothalamic transcription factor that controls the expression of prohormone convertase 1/3, therefore having an impact on the processing of proopiomelanocortin and thus on energy homeostasis. Studies have shown that KO of Nhlh2 results in increased body mass, reduced physical activity, and hypogonadism. In humans, a polymorphism of the NHLH2 gene is associated with obesity; and in Prader-Willi syndrome, a condition characterized by obesity, hypogonadism and behavioral abnormalities, the expression of NHLH2 is reduced. Despite clinical and experimental evidence suggesting that NHLH2 could be a good target for the treatment of obesity, no previous study has evaluated the impact of NHLH2 overexpression in obesity. Here, in mice fed a high-fat diet introduced right after the arcuate nucleus intracerebroventricular injection of a lentivirus that promoted 40% increase in NHLH2, there was prevention of the development of obesity by a mechanism dependent on the reduction of caloric intake. When hypothalamic overexpression of NHLH2 was induced in previously obese mice, the beneficial impact on obesity-associated phenotype was even greater; thus, there was an 80% attenuation in body mass gain, reduced whole-body adiposity, increased brown adipose tissue temperature, reduced hypothalamic inflammation, and reduced liver steatosis. In this setting, the beneficial impact of hypothalamic overexpression of NHLH2 was a result of combined effects on caloric intake, energy expenditure, and physical activity. Moreover, the hypothalamic overexpression of NHLH2 reduced obesity-associated anxiety/depression behavior. Thus, we provide an experimental proof of concept supporting that hypothalamic NHLH2 is a good target for the treatment of obesity.SIGNIFICANCE STATEMENT Obesity is a highly prevalent medical condition that lacks an effective treatment. The main advance provided by this study is the demonstration of the beneficial metabolic and behavioral outcomes resulting from the overexpression of NHLH2 in the hypothalamus. When NHLH2 was overexpressed simultaneously with the introduction of a high-fat diet, there was prevention of obesity by a mechanism dependent on reduced caloric intake. Conversely, when NHLH2 was overexpressed in previously obese mice, there was reduction of the obese phenotype because of a combination of reduced caloric intake, increased physical activity, and increased thermogenesis. In addition, the overexpression of NHLH2 reduced anxiety/depression-like behavior. Thus, NHLH2 emerges as a potential target for the combined treatment of obesity and its associated anxiety/depression-like behavior.

Combined training increases thermogenic fat activity in patients with overweight and type 2 diabetes.

BACKGROUND: Exercise is an important strategy in the management of diabetes. Experimental studies have shown that exercise acts, at least in part, by inducing the production of myokines that improve metabolic control and activate brown/beige adipose tissue depots. Combined training (CT) is recommended by the major diabetes guidelines due to its metabolic and cardiovascular benefits, however, its impact on brown/beige adipose tissue activities has never been tested in humans with overweight and type 2 diabetes (T2D). Here, we evaluated the effects of 16-week combined training (CT) program on brown adipose tissue activity; browning and autophagy markers, and serum pro-thermogenic/inflammatory inducers in patients with overweight and T2D. METHODS: Thirty-four patients with overweight and T2D were assigned to either a control group (CG) or a combined training group (CTG) in a randomized and controlled study. Functional/fitness parameters, anthropometry/body composition parameters, blood hormone/biochemical parameters, thermogenic/autophagic gene expression in subcutaneous adipose tissue were evaluated before and at the end of the intervention. In addition, cold-induced 18-Fluoroxyglucose Positron Emission Computed Tomography (18F-FDG PET/CT) was performed in the training group before and after the end of the intervention. RESULTS: CT increased cervical/supraclavicular brown adipose tissue (BAT) thermogenic activity (p = 0.03) as well as in perirenal adipose tissue (p = 0.02). In addition, CT increased the expression of genes related to thermogenic profile (TMEM26: + 95%, p = 0.04; and EPSTI1: + 26%, p = 0.03) and decreased autophagic genes (ULK1: -15%, p = 0.04; LC3: -5%, p = 0.02; and ATG4: -22%, p < 0.001) in subcutaneous adipose tissue. There were positive correlations between Δ% BAT activity with Δ% of post training energy expenditure cold exposure, HDL-c, IL4, adiponectin, irisin, meteorin-like, and TMEM26 and ZIC1 genes, besides negative correlations with LDL-c, total cholesterol and C-reactive protein. CONCLUSION: This is the first evidence of the beneficial actions of CT on adipose tissue thermogenic activity in humans, and it adds important support for the recommendation of CT as a strategy in the management of diabetes.

Endoplasmic Reticulum Stress in Colonic Mucosa of Ulcerative Colitis Patients Is Mediated by PERK and IRE1 Pathway Activation.

Ulcerative colitis (UC) is characterized by a chronic overproduction of proinflammatory cytokines. During an acute phase, the endoplasmic reticulum (ER) is overloaded and the protein folding process is impaired, a condition named ER stress. This state induces a response (unfolded protein response (UPR)), initiated by the activation of IRE1/Xbp-1, PERK/eIF2α, and ATF6 pathways, which has previously been linked to intestinal inflammation in experimental models. ER stress and UPR activation trigger the activation of proinflammatory, autophagy, and apoptosis genes, in addition to promoting protein degradation. Therefore, the goal of this study was to evaluate the activation of ER stress and UPR in colonic mucosa of UC patients. Patient and Methods. Transcriptional analysis of ER stress- and UPR-related genes was performed by qPCR from intestinal mucosa of patients with UC. We also performed in situ hybridization (ISH) and immunohistochemistry (IHQ) of PERK/eIF2α and IRE1/Xbp-1 pathways and UPR-related chaperones. Results. We first evaluated inflammatory genes via qPCR, and we observed that all analyzed proinflammatory transcripts were upregulated in UC patients. ISH and IHQ images showed that ER stress is activated via PERK/eIF2α and IRE1/Xbp-1 pathways not only in intestinal epithelial cells but also in cells of the lamina propria of UC colonic mucosa. Transcriptional analysis confirmed that EIF2AK3 was upregulated in UC patients. UPR-related genes, such as ATF3, STC2, and DDIT3, along with the chaperones and cochaperones DNAJC3, CALR, HSP90B1, and HSPA5, were also upregulated in UC patients. In addition, we observed that proapoptotic and autophagy genes (Bax and ATG6L1, respectively) were also upregulated. Conclusion. Our results suggest that ER stress and UPR are indeed activated in UC patients and this may contribute to the chronic inflammatory process seen in UC. The increased apoptosis and autophagy markers further support the activation of these findings once they are activated to counterbalance tissue damage. These findings provide new insights into the molecular mechanisms that maintain UC activity and open new possibilities to attenuate intestinal inflammation.

Interleukin-6 actions in the hypothalamus protects against obesity and is involved in the regulation of neurogenesis.

BACKGROUND: Interleukin-6 (IL6) produced in the context of exercise acts in the hypothalamus reducing obesity-associated inflammation and restoring the control of food intake and energy expenditure. In the hippocampus, some of the beneficial actions of IL6 are attributed to its neurogenesis-inducing properties. However, in the hypothalamus, the putative neurogenic actions of IL6 have never been explored, and its potential to balance energy intake can be an approach to prevent or attenuate obesity. METHODS: Wild-type (WT) and IL6 knockout (KO) mice were employed to study the capacity of IL6 to induce neurogenesis. We used cell labeling with Bromodeoxyuridine (BrdU), immunofluorescence, and real-time PCR to determine the expression of markers of neurogenesis and neurotransmitters. We prepared hypothalamic neuroprogenitor cells from KO that were treated with IL6 in order to provide an ex vivo model to further characterizing the neurogenic actions of IL6 through differentiation assays. In addition, we analyzed single-cell RNA sequencing data and determined the expression of IL6 and IL6 receptor in specific cell types of the murine hypothalamus. RESULTS: IL6 expression in the hypothalamus is low and restricted to microglia and tanycytes, whereas IL6 receptor is expressed in microglia, ependymocytes, endothelial cells, and astrocytes. Exogenous IL6 reduces diet-induced obesity. In outbred mice, obesity-resistance is accompanied by increased expression of IL6 in the hypothalamus. IL6 induces neurogenesis-related gene expression in the hypothalamus and in neuroprogenitor cells, both from WT as well as from KO mice. CONCLUSION: IL6 induces neurogenesis-related gene expression in the hypothalamus of WT mice. In KO mice, the neurogenic actions of IL6 are preserved; however, the appearance of new fully differentiated proopiomelanocortin (POMC) and neuropeptide Y (NPY) neurons is either delayed or disturbed.

TGF-ß1 downregulation in the hypothalamus of obese mice through acute exercise.

Obesity and aging lead to abnormal transforming growth factor-ß1 (TGF-ß1) signaling in the hypothalamus, triggering the imbalance on glucose metabolism and energy homeostasis. Here, we determine the effect of acute exercise on TGF-ß1 expression in the hypothalamus of two models of obesity in mice. The bioinformatics analysis was performed to evaluate the correlation between hypothalamic Tgf-ß1 messenger RNA (mRNA) and genes related to thermogenesis in the brown adipose tissue (BAT) by using a large panel of isogenic BXD mice. Thereafter, leptin-deficient (ob/ob) mice and obese C57BL/6 mice fed on a high-fat diet (HFD) were submitted to the acute exercise protocol. Transcriptomic analysis by using BXD mouse reference population database revealed that hypothalamic Tgf-ß1 mRNA is negatively correlated with genes related to thermogenesis in brown adipose tissue of BXD mice, such as peroxisome proliferator-activated receptor gamma coactivator and is positively correlated with respiratory exchange ratio. In agreement with these results, leptin-deficient (ob/ob) and HFD-fed mice displayed high levels of Tgf-ß1 mRNA in the hypothalamus and reduction of Pgc1α mRNA in BAT. Interestingly, an acute exercise session reduced TGF-ß1 expression in the hypothalamus, increased Pgc1α mRNA in the BAT and reduced food consumption in obese mice. Our results demonstrated that acute physical exercise suppressed hypothalamic TGF-ß1 expression, increasing Pgc1α mRNA in BAT in obese mice.

Breast Lipofilling Does Not Pose Evidence of Chronic Inflammation in Rats.

BACKGROUND: Laboratory reports on adipose tissue suggest that fat grafting to the breast may pose an oncologic risk. One possible reason for this is the theoretic chronic inflammation due to adipokynes released by grafted white adipose tissue (WAT). OBJECTIVES: The aim of this study was to analyze inflammatory activity in lipofilled breast through the use of proinflammatory markers. METHODS: Fifty-four paired-breasts of female rats were divided into 4 groups: control, sham, and breasts grafted with either autologous subcutaneous (SC) WAT or autologous omentum (OM). The WAT was prepared through centrifugation, and the grafting was performed with the use of 0.9-mm blunt-tip cannula. The rats were killed 8 weeks postoperatively, and their breasts were harvested for immunohistochemical staining for CD68-expressing macrophages, gene expression (real-time PCR) for monocyte chemoattractant protein 1 (MCP-1), F4/80, Cox-2, and IL-6. RESULTS: The weights of the rats that underwent a procedure differed from those of the unmanipulated control group (P < 0.01). The macrophage counts of CD68 differed only between breasts lipofilled with OM and control (P < 0.01). MCP-1, F4/80, and Cox-2 were similarly expressed among the groups (P = 0.422, P = 0.143, and P = 0.209, respectively). The expression of IL-6 differed between breast samples grafted with SC and OM WAT (P = 0.015), but not between samples of control and OM (P = 0.752), and control and SC (P = 0.056). CONCLUSIONS: No inflammation activity was identified in the microenvironment of lipofilled breasts, indicating that chronic inflammation does not seem to be triggered by the breast lipofilling procedure.

Exercise activates the hypothalamic S1PR1-STAT3 axis through the central action of interleukin 6 in mice.

Hypothalamic sphingosine-1-phosphate receptor 1 (S1PR1), the G protein-coupled receptor 1 of sphingosine-1-phosphate, has been described as a modulator in the control of energy homeostasis in rodents. However, this mechanism is still unclear. Here, we evaluate the role of interleukin 6 (IL-6) associated with acute physical exercise in the control of the hypothalamic S1PR1-signal transducer and activator of transcription 3 (STAT3) axis. Acute exercise session and an intracerebroventricular IL-6 injection increased S1PR1 protein content and STAT3 phosphorylation in the hypothalamus of lean and obese mice accompanied by a reduction in food consumption. Transcriptome analysis indicated a strong positive correlation between Il-6 and S1pr1 messenger RNA in several tissues of genetically diverse BXD mice strains and humans, including in the hypothalamus. Interestingly, exercise failed to stimulate the S1PR1-STAT3 axis in IL-6 knockout mice and the disruption of hypothalamic-specific IL-6 action blocked the anorexigenic effects of exercise. Taken together, our results indicate that physical exercise modulates the S1PR1 protein content in the hypothalamus, through the central action of IL-6.

Dietary fats promote functional and structural changes in the median eminence blood/spinal fluid interface-the protective role for BDNF.

BACKGROUND: The consumption of large amounts of dietary fats activates an inflammatory response in the hypothalamus, damaging key neurons involved in the regulation of caloric intake and energy expenditure. It is currently unknown why the mediobasal hypothalamus is the main target of diet-induced brain inflammation. We hypothesized that dietary fats can damage the median eminence blood/spinal fluid interface. METHODS: Swiss mice were fed on a high-fat diet, and molecular and structural studies were performed employing real-time PCR, immunoblot, immunofluorescence, transmission electron microscopy, and metabolic measurements. RESULTS: The consumption of a high fat diet was sufficient to increase the expression of inflammatory cytokines and brain-derived neurotrophic factor in the median eminence, preceding changes in other circumventricular regions. In addition, it led to an early loss of the structural organization of the median eminence ß1-tanycytes. This was accompanied by an increase in the hypothalamic expression of brain-derived neurotrophic factor. The immunoneutralization of brain-derived neurotrophic factor worsened diet-induced functional damage of the median eminence blood/spinal fluid interface, increased diet-induced hypothalamic inflammation, and increased body mass gain. CONCLUSIONS: The median eminence/spinal fluid interface is affected at the functional and structural levels early after introduction of a high-fat diet. Brain-derived neurotrophic factor provides an early protection against damage, which is lost upon a persisting consumption of large amounts of dietary fats.

Inhibition of hypothalamic leukemia inhibitory factor exacerbates diet-induced obesity phenotype.

BACKGROUND: The consumption of large amounts of dietary fats can trigger an inflammatory response in the hypothalamus and contribute to the dysfunctional control of caloric intake and energy expenditure commonly present in obesity. The objective of this study was to identify chemokine-related transcripts that could be involved in the early stages of diet-induced hypothalamic inflammation. METHODS: We used immunoblot, PCR array, real-time PCR, immunofluorescence staining, glucose and insulin tolerance tests, and determination of general metabolic parameters to evaluate markers of inflammation, body mass variation, and glucose tolerance in mice fed a high-fat diet. RESULTS: Using a real-time PCR array, we identified leukemia inhibitory factor as a chemokine/cytokine undergoing a rapid increase in the hypothalamus of obesity-resistant and a rapid decrease in the hypothalamus of obesity-prone mice fed a high-fat diet for 1 day. We hypothesized that the increased hypothalamic expression of leukemia inhibitory factor could contribute to the protective phenotype of obesity-resistant mice. To test this hypothesis, we immunoneutralized hypothalamic leukemia inhibitory factor and evaluated inflammatory and metabolic parameters. The immunoneutralization of leukemia inhibitory factor in the hypothalamus of obesity-resistant mice resulted in increased body mass gain and increased adiposity. Body mass gain was mostly due to increased caloric intake and reduced spontaneous physical activity. This modification in the phenotype was accompanied by increased expression of inflammatory cytokines in the hypothalamus. In addition, the inhibition of hypothalamic leukemia inhibitory factor was accompanied by glucose intolerance and insulin resistance. CONCLUSION: Hypothalamic expression of leukemia inhibitory factor may protect mice from the development of diet-induced obesity; the inhibition of this protein in the hypothalamus transforms obesity-resistant into obesity-prone mice.

Assessment of the Cancer Risk of the Fat-Grafted Breast in a Murine Model.

Background: The results of experimental studies indicate that grafting of autologous adipose tissue may induce tumorigenesis at the recipient site, but clinical results do not support a carcinogenic effect of fat grafting to the breast. Objectives: The authors assessed cancer risk following transplantation of autologous fat into murine mammary tissue. Methods: In this animal study, mammary tissues from 54 breasts of 9 female rats were either grafted with autologous subcutaneous fat, grafted with autologous omental fat, or unmanipulated. Tissues were harvested and processed for histologic and immunohistochemical analyses, and the mRNA expression levels of specific genes were determined. Results: No atypia or changes in lobular structures were observed in lipofilled breasts compared with controls. The numbers of ductal cell layers and terminal ductal units were similar for lipofilled and control breasts. Macrophage concentrations also were similar for the 3 groups. The localization and magnitude of plasminogen activator inhibitor 1 were similar for lipofilled and unmanipulated breast tissue. The percentages of cells expressing Ki67 or estrogen receptor (ER) and the ER/Ki67 balance were similar for the 3 groups. Gene expression was not altered in lipofilled breasts, compared with controls. Conclusions: No theoretical risk of cancer was detected in the microenvironment of the lipofilled rat breast.

Oral Mucositis in Pediatric Acute Lymphoblastic Leukemia Patients: Evaluation of Microbiological and Hematological Factors.

OBJECTIVE: to investigate the associations of oral microbiota, leucocytes count, neutrophil count, platelet counts and hemoglobin level, and the severity of oral mucositis in pediatric patients with acute lymphoblastic leukemia (ALL) receiving chemotherapy. MATERIALS AND METHODS: 71 prospective patients were included. Analyses of oral microbiota and blood sample were conducted on days 14 (D14) and 56 (D56) of the Brazilian GBTLI-99 treatment protocol. Herpes simplex virus (HSV) identification was performed by PCR followed by DNA sequencing analysis. Bacteria and fungi identification was obtained by standard microbiological culture tests. RESULTS: 103 episodes of mucositis occurred, being 65 at D14 and 38 at D56. Most cases positive for herpes viral DNA sequences were identified as HSV-1. At D14, we found a significant association between the severity of mucositis and presence of HSV-1 (p = 0.0347), Candida spp. (p = 0.0078), and low platelet count (p = 0.0064). At D56, we found a significant association between the severity of mucositis and the presence of HSV-1 (p = 0.0317), previous HSV-1 presence on D14 (p < 0.0001) and neutrophil count (p = 0.0211). CLINICAL RELEVANCE: the identification of risk factors for mucositis in children and adolescents may contribute to the development of new strategies for prevention and/or treatment, reducing the complications associated with this condition. CONCLUSIONS: the presence of HSV, platelet count, and Candida spp. presence at D14 of ALL induction treatment is associated with increased severity of mucositis in children and adolescents. At D56 of ALL treatment, mucositis severity was associated with neutrophil count, HSV presence, and previous presence of HSV (at D14).

Pubertal glyphosate-based herbicide exposure aggravates high-fat diet-induced obesity in female mice.

Glyphosate-based herbicides (GBH) are the most widely used pesticides globally. Studies have indicated that they may increase the risk of various organic dysfunctions. Herein, we verified whether exposure to GBH during puberty increases the susceptibility of male and female mice to obesity when they are fed a high-fat diet (HFD) in adulthood. From the 4th-7th weeks of age, male and female C57Bl/6 mice received water (CTL group) or 50 mg GBH /kg body weight (BW; GBH group). From the 8th-21st weeks of age, the mice were fed a standard diet or a HFD. It was found that pubertal GBH exposure exacerbated BW gains and hyperphagia induced by HFD, but only in female GBH-HFD mice. These female mice also exhibited high accumulation of perigonadal and subcutaneous fat, as well as reduced lean body mass. Both male and female GBH-HFD displayed hypertrophic white adipocytes. However, only in females, pubertal GBH exposure aggravated HFD-induced fat accumulation in brown adipocytes. Furthermore, GBH increased plasma cortisol levels by 80% in GBH-HFD males, and 180% in GBH-HFD females. In conclusion, pubertal GBH exposure aggravated HFD-induced obesity, particularly in adult female mice. This study provides novel evidence that GBH misprograms lipid metabolism, accelerating the development of obesity when individuals are challenged by a second metabolic stressor, such as an obesogenic diet.

Digestion of whey peptide induces antioxidant and anti-inflammatory bioactivity on glial cells: Sequences identification and structural activity analysis.

Whey derived peptides have shown potential activity improving brain function in pathological condition. However, there is little information about their mechanism of action on glial cells, which have important immune functions in brain. Astrocytes and microglia are essential in inflammatory and oxidative defense that take place in neurodegenerative disease. In this work we evaluate antioxidant and anti-inflammatory potential bioactivity of whey peptide in glial cells. Peptides were formed during simulated gastrointestinal digestion (Infogest protocol), and low molecular weight (<5kDA) peptides (WPHf) attenuated reactive oxygen species (ROS) production induced by hydrogen peroxide stimulus in both cells in dose-dependent manner. WPHf induced an increase in the antioxidant glutathione (GSH) content and prevented GSH reduction induced by lipopolysaccharides (LPS) stimulus in astrocytes cells in a cell specific form. An increase in cytokine mRNA expression (TNFα and IL6) and nitric oxide secretion induced by LPS was attenuated by WPHf pre-treatment in both cells. The inflammatory pathway was dependent on NFκB activation. Bioactive peptide ranking analysis showed positive correlation with hydrophobicity and negative correlation with high molecular weights. The sequence identification revealed 19 peptides cross-referred with bioactive database. Whey peptides were rich in leucine, valine and tyrosine in the C-terminal region and lysine in the N-terminal region. The anti-inflammatory and antioxidant potential of whey peptides were assessed in glia cells and its mechanisms of action were related, such as modulation of antioxidant enzymes and anti-inflammatory pathways. Features of the peptide structure, such as molecular size, hydrophobicity and types of amino acids present in the terminal region are associated to bioactivity.

In Vitro and In Vivo Evaluation of Chitosan/HPMC/Insulin Hydrogel for Wound Healing Applications.

Treatment of chronic wounds is challenging, and the development of different formulations based on insulin has shown efficacy due to their ability to regulate oxidative stress and inflammatory reactions. The formulation of insulin with polysaccharides in biohybrid hydrogel systems has the advantage of synergistically combining the bioactivity of the protein with the biocompatibility and hydrogel properties of polysaccharides. In this study, a hydrogel formulation containing insulin, chitosan, and hydroxypropyl methyl cellulose (Chi/HPMC/Ins) was prepared and characterized by FTIR, thermogravimetric, and gel point analyses. The in vitro cell viability and cell migration potential of the Chi/HPMC/Ins hydrogel were evaluated in human keratinocyte cells (HaCat) by MTT and wound scratch assay. The hydrogel was applied to excisional full-thickness wounds in diabetic mice for twenty days for in vivo studies. Cell viability studies indicated no cytotoxicity of the Chi/HPMC/Ins hydrogel. Moreover, the Chi/HPMC/Ins hydrogel promoted faster gap closure in the scratch assay. In vivo, the wounds treated with the Chi/HPMC/Ins hydrogel resulted in faster wound closure, formation of a more organized granulation tissue, and hair follicle regeneration. These results suggest that Chi/HPMC/Ins hydrogels might promote wound healing in vitro and in vivo and could be a new potential dressing for wound healing.

Hypothalamic free fatty acid receptor-1 regulates whole-body energy balance.

OBJECTIVE: Free fatty acid receptor-1 (FFAR1) is a medium- and long-chain fatty acid sensing G protein-coupled receptor that is highly expressed in the hypothalamus. Here, we investigated the central role of FFAR1 on energy balance. METHODS: Central FFAR1 agonism and virogenic knockdown were performed in mice. Energy balance studies, infrared thermographic analysis of brown adipose tissue (BAT) and molecular analysis of the hypothalamus, BAT, white adipose tissue (WAT) and liver were carried out. RESULTS: Pharmacological stimulation of FFAR1, using central administration of its agonist TUG-905 in diet-induced obese mice, decreases body weight and is associated with increased energy expenditure, BAT thermogenesis and browning of subcutaneous WAT (sWAT), as well as reduced AMP-activated protein kinase (AMPK) levels, reduced inflammation, and decreased endoplasmic reticulum (ER) stress in the hypothalamus. As FFAR1 is expressed in distinct hypothalamic neuronal subpopulations, we used an AAV vector expressing a shRNA to specifically knockdown Ffar1 in proopiomelanocortin (POMC) neurons of the arcuate nucleus of the hypothalamus (ARC) of obese mice. Our data showed that knockdown of Ffar1 in POMC neurons promoted hyperphagia and body weight gain. In parallel, these mice developed hepatic insulin resistance and steatosis. CONCLUSIONS: FFAR1 emerges as a new hypothalamic nutrient sensor regulating whole body energy balance. Moreover, pharmacological activation of FFAR1 could provide a therapeutic advance in the management of obesity and its associated metabolic disorders.

IL-6 and IL-10 anti-inflammatory activity links exercise to hypothalamic insulin and leptin sensitivity through IKKbeta and ER stress inhibition.

Overnutrition caused by overeating is associated with insulin and leptin resistance through IKKbeta activation and endoplasmic reticulum (ER) stress in the hypothalamus. Here we show that physical exercise suppresses hyperphagia and associated hypothalamic IKKbeta/NF-kappaB activation by a mechanism dependent upon the pro-inflammatory cytokine interleukin (IL)-6. The disruption of hypothalamic-specific IL-6 action blocked the beneficial effects of exercise on the re-balance of food intake and insulin and leptin resistance. This molecular mechanism, mediated by physical activity, involves the anti-inflammatory protein IL-10, a core inhibitor of IKKbeta/NF-kappaB signaling and ER stress. We report that exercise and recombinant IL-6 requires IL-10 expression to suppress hyperphagia-related obesity. Moreover, in contrast to control mice, exercise failed to reverse the pharmacological activation of IKKbeta and ER stress in C3H/HeJ mice deficient in hypothalamic IL-6 and IL-10 signaling. Hence, inflammatory signaling in the hypothalamus links beneficial physiological effects of exercise to the central action of insulin and leptin.

Freeze-dried jaboticaba peel powder improves insulin sensitivity in high-fat-fed mice.

The peel of the native Brazilian fruit jaboticaba is rich in anthocyanins, which are known for their anti-obesity effects in animal models. The aim of the present study was to evaluate the effects of freeze-dried jaboticaba peel powder (FDJPP) on a number of metabolic parameters in a model of diet-induced obesity. Mice (n 8 per group) were initially fed on a high-fat diet (HFD, 35% w/w) for 4 weeks and then switched to a HFD supplemented with FDJPP (1, 2 or 4% w/w) for an additional 6 weeks. Energy intake, weight loss, glucose tolerance, insulin resistance and lipid profile were determined, and the results were evaluated using ANOVA and Tukey's tests. The FDJPP exerted no protective effect on HFD-induced weight gain, hyperleptinaemia and glucose intolerance. However, the supplementation was effective to reduce insulin resistance, as evidenced in the insulin tolerance test, and subsequently confirmed by improved signal transduction through the insulin receptor/insulin receptor substrate-1/Akt/forkhead box protein pathway and by the attenuation of HFD-induced inflammation in the liver, verified by lower expressions of IL-1b and IL-6 and decreased phosphorylated IkB-a protein levels in all jaboticaba-treated mice. These results suggest that FDJPP may exert a protective role against obesity-associated insulin resistance.