ovalbumin and Obesity

It has been suggested previously that in the fasting state the administration of amino acids alone would be more effective in sparing protein than the administration of amino acids plus small amounts of glucose. In the present study we have examined the effect of administration of amino acids alone (1 g/kg per day) and of the same regimen supplemented with 100 g glucose daily, on the nitrogen balance in 10 subjects, six of whom were obese and four undernourished. Mean cumulative nitrogen balance over a 5-day study period was -12.4 g on amino acids alone and +0.5 g when glucose was added (P less than 0.01). It thus appears that the addition of glucose may be beneficial rather than harmful in subjects receiving amino acid therapy.

Topics: Adult; Aged; Amino Acids; Dietary Carbohydrates; Dietary Proteins; Female; Glucose; Humans; Male; Middle Aged; Nitrogen; Nutrition Disorders; Obesity; Ovalbumin

Obesity increases the severity of airway hyperresponsiveness (AHR) in individuals with asthma, but the mechanism is not well elucidated. G-protein coupled receptor 40 (GPR40) has been found to induce airway smooth muscle contraction after activated by long-chain fatty acids (LC-FFAs), suggesting a close correlation between GPR40 and AHR in obese. In this study, C57BL/6 mice were fed a high-fat diet (HFD) to induce obesity with or without ovalbumin (OVA) sensitization, the regulatory effects of GPR40 on AHR, inflammatory cells infiltration, and the expression of Th1/Th2 cytokines were evaluated by using a small-molecule antagonist of GPR40, DC260126. We found that the free fatty acids (FFAs) level and GPR40 expression were greatly elevated in the pulmonary tissues of obese asthmatic mice. DC260126 greatly reduced methacholine-induced AHR, ameliorated pulmonary pathological changes and decreased inflammatory cell infiltration in the airways in obese asthma. In addition, DC260126 could down-regulate the levels of Th2 cytokines (IL-4, IL-5, and IL-13) and pro-inflammatory cytokines (IL-1β, TNF-α), but elevated Th1 cytokine (IFN-γ) expression. In vitro, DC260126 could remarkedly reduce oleic acid (OA)-induced cell proliferation and migration in HASM cells. Mechanistically, the effects that DC260126 alleviated obese asthma was correlated with the down-regulation of GTP-RhoA and Rho-associated coiled-coil-forming protein kinase 1 (ROCK1). Herein, we proved that targeting of GPR40 with its antagonist helped to mitigate multiple parameters of obese asthma effectively.

Topics: Animals; Asthma; Cytokines; Disease Models, Animal; Lung; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Obese; Obesity; Ovalbumin; Receptors, G-Protein-Coupled; Respiratory Hypersensitivity; Signal Transduction

Obesity and type 2 diabetes (T2D) have been found to be associated with abnormalities in several organs, including the intestine. These conditions can lead to changes in gut homeostasis, compromising tolerance to luminal antigens and increasing susceptibility to food allergies. The underlying mechanisms for this phenomenon are not yet fully understood. In this study, we investigated changes in the intestinal mucosa of diet-induced obese mice and found that they exhibited increased gut permeability and reduced Treg cells frequency. Upon oral treatment with ovalbumin (OVA), obese mice failed to develop oral tolerance. However, hyperglycemia treatment improved intestinal permeability and oral tolerance induction in mice. Furthermore, we observed that obese mice exhibited a more severe food allergy to OVA, and this allergy was alleviated after treatment with a hypoglycemic drug. Importantly, our findings were translated to obese humans. Individuals with T2D had higher serum IgE levels and downregulated genes related to gut homeostasis. Taken together, our results suggest that obesity-induced hyperglycemia can lead to a failure in oral tolerance and to exacerbation of food allergy. These findings shed light on the mechanisms underlying the relationship among obesity, T2D, and gut mucosal immunity, which could inform the development of new therapeutic approaches.

Topics: Administration, Oral; Allergens; Animals; Diabetes Mellitus, Type 2; Food Hypersensitivity; Humans; Immune Tolerance; Mice; Mice, Inbred BALB C; Mice, Obese; Obesity; Ovalbumin

Obesity-related asthma is a kind of nonallergic asthma with excessive neutrophil infiltration in the airways. However, the underlying mechanisms have been poorly elucidated. Among the adipokines related to obesity, leptin is related to the inflammatory response. However, little is understood about how leptin acts on the leptin receptor (obR) in neutrophilic airway inflammation in obesity-associated asthma. We explored the inflammatory effects of leptin/obR signaling in an obesity-related neutrophilic airway inflammation mouse model.. We established a neutrophilic airway inflammation mouse model using lipopolysaccharide (LPS)/ovalbumin (OVA) sensitization and OVA challenge (LPS + OVA/OVA) in lean, obese, or db/db (obR deficiency) female mice. Histopathological, bronchoalveolar lavage fluid (BALF) inflammatory cell, and lung inflammatory cytokine analyses were used to analyze airway inflammation severity. Western blotting, flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR), and enzyme-linked immunosorbent assay (ELISA) were used to evaluate the underlying mechanisms. In vitro bone marrow-derived macrophage (BMDM) and bone marrow-derived neutrophil experiments were performed.. We found that the serum leptin level was higher in obese than in lean female mice. Compared to LPS/OVA + OVA-treated lean female mice, LPS/OVA + OVA-treated obese female mice had higher peribronchial inflammation levels, neutrophil counts, Th1/Th17-related inflammatory cytokine levels, M1 macrophage polarization levels, and long isoform obR activation, which could be decreased by the obR blockade (Allo-Aca) or obR deficiency, suggesting a critical role of leptin/obR signaling in the pathogenesis of obesity-related neutrophilic airway inflammation in female mice. In in vitro experiments, leptin synergized with LPS/IFN-γ to promote the phosphorylation of the long isoform obR and JNK/STAT3/AKT signaling pathway members to increase M1 macrophage polarization, which was reversed by Allo-Aca. Moreover, leptin/obR-mediated M1 macrophage activity significantly elevated CXCL2 production and neutrophil recruitment by regulating the JNK/STAT3/AKT pathways. In clinical studies, obese patients with asthma had higher serum leptin levels and M1 macrophage polarization levels in induced sputum than non-obese patients with asthma. Serum leptin levels were positively correlated with M1 macrophage polarization levels in patients with asthma.. Our results demonstrate leptin/obR signaling plays an important role in the pathogenesis of obesity-related neutrophilic airway inflammation in females by promoting M1 macrophage polarization.

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Female; Inflammation; Leptin; Lipopolysaccharides; Lung; Macrophages; Mice; Mice, Inbred BALB C; Obesity; Ovalbumin; Proto-Oncogene Proteins c-akt; Receptors, Leptin; Signal Transduction

Despite recent investigations on the role of chitinase in asthma, its role in obesity-induced asthma has not been evaluated. Therefore, we investigated the roles of chitin, chitinase-1, and a chitinase-1 inhibitor (compound X, CPX) in a murine model.. We assigned C57BL/6 mice to the ovalbumin (OVA) model or obesity model group. In the OVA model, mice received intraperitoneal OVA twice within a 2-week interval and intranasal OVA for 3 consecutive days. Additionally, chitin was intranasally administered for 3 consecutive days, and CPX was intraperitoneally injected three times over 5 days. In the obesity model, a high-fat diet (HFD) was maintained for 13 weeks, and CPX was intraperitoneally injected eight times over 4 weeks.. In the OVA model, chitin aggravated OVA-induced airway hyper-responsiveness (AHR), increased bronchoalveolar lavage fluid (BALF) cell proliferation, increased fibrosis, and increased the levels of various inflammatory cytokines (including chitinase-1, TGF-β, TNF-α, IL-1 β, IL-6, IL-4, and IL-13). CPX treatment significantly ameliorated these effects. In the obesity model, HFD significantly increased AHR, BALF cell proliferation, fibrosis, and the levels of various inflammatory cytokines. Particularly, compared to the control group, the mRNA expression of chitinase, chitinase-like molecules, and other molecules associated with inflammation and the immune system was significantly upregulated in the HFD and HFD/OVA groups. Immunofluorescence analysis also showed increased chitinase-1 expression in these groups. CPX significantly ameliorated all these effects in this model.. This study showed that CPX can be an effective therapeutic agent in asthma, especially, obesity-induced and -aggravated asthma to protect against the progression to airway remodeling and fibrosis.

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; Chitin; Cytokines; Disease Models, Animal; Fibrosis; Lung; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Obesity; Ovalbumin

The association between asthma and obesity has been shown but its accurate mechanism is unknown. In the current study, we sought to investigate the gene expression levels of IL-17/TRAF6/MAPK/USP25 axis and pro-inflammatory cytokine level (IL-6, IL-1β, and TNF-α) in obese Ovalbumin (OVA)-sensitized female and male Wistar rats lung tissue.. Animals in both males and females were divided into eight groups (four groups in each sex) based on diet and OVA-sensitization: normal diet, a normal diet with OVA-sensitization, high-fat diet (HFD), and OVA-sensitization with an HFD.. The results indicate that in obese OVA-sensitized rats, the IL-17 axis were involved in the pathogenesis of the disease and can be considered as a therapeutic target in subjects with obesity-related asthma.

Topics: Animals; Body Weight; Cytokines; Female; Gene Expression Regulation; Interleukin-17; Lung; Male; Methacholine Chloride; Mitogen-Activated Protein Kinase Kinases; Obesity; Ovalbumin; Rats, Wistar; TNF Receptor-Associated Factor 6; Trachea; Ubiquitin Thiolesterase

Dietary lipids, highly lipophilic drugs, antigens and immune cells are transported from the intestine to the mesenteric lymph nodes (MLNs) via mesenteric lymphatic vessels. Recently our lab reported that the mesenteric lymphatic vessels become highly branched and leak lymph to the surrounding mesenteric adipose tissue (MAT) in mice and humans with obesity, promoting insulin resistance. This study aimed to investigate the impact of obesity-associated mesenteric lymph leakage on the trafficking of a dietary lipid (oleic acid), lipophilic drug (cyclosporin A) and antigen (ovalbumin) from the intestine to MLNs. C57BL/6J mice were fed a control fat diet (CFD), or a high fat diet (HFD) for up to 35 weeks leading to obesity and impaired glucose tolerance.

Topics: Animals; Cyclosporins; Humans; Intestines; Lymph Nodes; Mesentery; Mice; Mice, Inbred C57BL; Obesity; Oleic Acid; Ovalbumin

Cysteinyl leukotrienes (CysLTs), a group of inflammatory lipid mediators, are found elevated in obese-asthmatic patients. Leukotriene D. Primary human small airway epithelial cells (SAECs) were stimulated with different concentrations of LTD

Topics: Airway Remodeling; Allergens; Animals; Asthma; Bronchoalveolar Lavage Fluid; Cells, Cultured; Cytokines; Epithelial Cells; Humans; Inflammasomes; Inflammation; Leukocyte Count; Leukotriene D4; Male; Mice, Inbred BALB C; Mucin 5AC; NLR Family, Pyrin Domain-Containing 3 Protein; Obesity; Ovalbumin; Smad2 Protein; Smad3 Protein; Vimentin

Obesity increases the morbidity and severity of asthma, with poor sensitivity to corticosteroid treatment. Metformin has potential effects on improving asthma airway inflammation. Regulatory T cells (Tregs) play a key role in suppressing the immunoreaction to allergens. We built an obese asthmatic mouse model by administering a high-fat diet (HFD) and ovalbumin (OVA) sensitization, with daily metformin treatment. We measured the body weight and airway inflammatory status by histological analysis, qRT-PCR, and ELISA. The percentage of Tregs was measured by flow cytometry. Obese asthmatic mice displayed more severe airway inflammation and more significant changes in inflammatory cytokines. Metformin reversed the obese situation and alleviated the airway inflammation and remodelling with increased Tregs and related transcript factors. The anti-inflammatory function of metformin may be mediated by increasing Tregs.

Topics: Animals; Anti-Inflammatory Agents; Asthma; Body Weight; Bronchoalveolar Lavage Fluid; CD4 Lymphocyte Count; Diet, High-Fat; Disease Models, Animal; Humans; Hypoglycemic Agents; Inflammation; Interleukin-4; Lung; Metformin; Mice; Obesity; Ovalbumin; Spleen; T-Lymphocytes, Regulatory; Tumor Necrosis Factor-alpha

Obesity is a correctable factor for uncontrolled bronchial asthma. However, the effects of glucagon-like peptide-1 receptor (GLP-1R) agonist, a recently approved antiobestic drug, on airway hyperresponsiveness (AHR) and immune responses are not known.. Mice were fed with high-fat diet (HFD, 60% fat) for 8 weeks to induce obesity. Ovalbumin (OVA) sensitization and challenges were performed for 7 weeks. The mice were injected intraperitoneally with GLP-1R agonist 5 times a week for 4 weeks after OVA sensitization. After AHR measurement, expression of Th2, Th17 cytokines, and interleukin (IL)-33 were measured in BALF and lung tissues. Moreover, IL-1β and activity level of nucleotide oligomerization domain-like receptor protein 3 (NLRP3) were analyzed to investigate the mechanism of GLP-1R agonist on asthmatic airway inflammation.. HFD induced significant weight gain, OVA sensitization and challenge in obese mice made eosinophilic airway inflammation, and increased AHR. Treatment with GLP-1R agonist-induced weight loss suppressed eosinophilic airway inflammation and decreased AHR. Expression of IL-4, 5, and 33 was increased in BALF of obese asthma mice followed by a decrease in response to GLP-1R agonist treatment. Moreover, lung tissue H&E stain revealed that peribronchial inflammation induced by obesity and OVA was effectively suppressed by GLP-1R agonist. Expressions of NLRP3, activated caspase-1, and IL-1β were increased in lung tissues of obese asthma mice and demonstrated a decrease in response to GLP-1R agonist treatment.. GLP-1R agonist effectively induced weight loss, suppressed eosinophilic bronchial airway inflammation, and AHR in obese asthma mice. These effects were mediated by suppression of NLRP3 inflammasome activity and IL-1β. GLP-1R agonist is proposed as a novel anti-asthmatic agent targeting the obese asthmatics.

Topics: Animals; Asthma; Disease Models, Animal; Glucagon-Like Peptide 1; Inflammasomes; Inflammation; Mice; Mice, Inbred BALB C; Mice, Obese; NLR Family, Pyrin Domain-Containing 3 Protein; Obesity; Ovalbumin; Pharmaceutical Preparations

Although natural killer T cells (NKT cells) are altered in obese asthmatic mice, their function remains completely unclear. To further explore the potential mechanism of NKT cells in airway inflammation of obesity-associated asthma, we examined the effects of α-galactosylceramide (KRN7000) on airway inflammation in obese asthmatic mice. Male C57BL/6J mice were divided into five groups: (1) control; (2) asthma; (3) A + KRN, asthma with KRN7000; (4) obese asthma; and (5) OA + KRN, obese asthma with KRN7000. Cytometric bead array (CBA) was used to detect interleukin-4 (IL-4), IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) in the serum. Flow cytometry was used to detect NKT cells and CD69

Topics: Adjuvants, Immunologic; Animals; Asthma; Diet, High-Fat; Galactosylceramides; Inflammation Mediators; Killer Cells, Natural; Male; Mice; Mice, Inbred C57BL; Obesity; Ovalbumin

Magnesium deficiency common in obesity is known to promote chronic low-grade inflammation and aggravate asthma symptoms; however, the effects of magnesium supplementation in obese asthmatic patients have not been investigated.. To examine the effects of magnesium co-administration with dexamethasone on airway inflammation in obese mice.. Female C57BL/6 mice were fed a high-fat diet, sensitized with ovalbumin (OVA) to induce allergic reactions, challenged with aerosolized OVA, and administered dexamethasone (3 mg/kg) with or without magnesium. Bronchial inflammation was analyzed based on the presence of inflammatory cells and cytokines in bronchoalveolar lavage fluid, total and OVA-specific IgE in serum, goblet cells ratios, bronchial wall thickness, and expression of α-smooth muscle actin.. In obese mice, co-administration of magnesium and dexamethasone decreased IL-13 in bronchoalveolar lavage fluid and total and OVA-specific IgE in serum, and reduced α-smooth muscle actin-positive areas in the bronchi compared with mice treated with dexamethasone alone. However, no differences were observed in dexamethasone-treated normal-weight mice depending on magnesium supplementation.. These results suggest that magnesium increases immunosuppressive effects of dexamethasone in airway inflammation aggravated by obesity, suggesting that magnesium supplementation may have a potential in alleviating asthma symptoms in obese patients with reduced responses to corticosteroids.

Topics: Adrenal Cortex Hormones; Animals; Anti-Inflammatory Agents; Asthma; Bronchi; Bronchoalveolar Lavage Fluid; Cell Count; Cytokines; Dexamethasone; Diet, High-Fat; Female; Immunoglobulin E; Immunosuppressive Agents; Inflammation; Magnesium; Mice, Inbred C57BL; Obesity; Ovalbumin

Asthma outcomes is aggravated in obese patients. Excess of methylglyoxal (MGO) in obese/diabetic patients has been associated with diverse detrimental effects on cell function. This study aimed to evaluate the effects of long-term oral intake of MGO on ovalbumin-induced eosinophil inflammation. Male C57/Bl6 mice received 0.5% MGO in the drinking water for 12 weeks. Mice were sensitized and challenged with ovalbumin (OVA), and at 48 h thereafter, bronchoalveolar lavage (BAL) fluid and lungs were collected for cell counting, morphological analysis, and ELISA, mRNA expressions and DHE assays. In MGO-treated mice, OVA challenge significantly increased the peribronchiolar infiltrations of inflammatory cells and eosinophils compared with control group. Higher levels of IL-4, IL-5, and eotaxin in BAL fluid were also detected in MGO compared with control group. In addition, lung tissue of MGO-treated mice displayed significant increases in mRNA expressions of NF-κB and iNOS whereas COX-2 expression remained unchanged. The high TNF-α mRNA expression observed in lungs of OVA-challenged control mice was not further increased by MGO treatment. In MGO group, OVA-challenge increased significantly the NOX-2 and NOX-4 mRNA expressions, without affecting the NOX-1 expression. Levels of reactive-oxygen species (ROS) were significantly higher in lungs of MGO-treated mice, and no further increase by OVA-challenge was observed. In conclusion, 12-week intake of MGO exacerbates Th2-mediated airway eosinophil infiltration by activation of NF-kB/iNOS-dependent signaling pathway and positive regulation of NOX-2 and NOX-4 in the lung tissues. Scavengers of MGO could be an option to prevent obesity-related asthma.

Topics: Allergens; Animals; Asthma; Cell Movement; Disease Models, Animal; Eosinophils; Humans; Interleukin-4; Interleukin-5; Male; Mice; Mice, Inbred C57BL; NADPH Oxidase 4; NF-kappa B; Obesity; Ovalbumin; Pyruvaldehyde; Reactive Oxygen Species; Signal Transduction; Th2 Cells

Previous studies showed a close relationship between obesity and asthma. In this study, we investigated the expression of endoplasmic reticulum (ER) stress genes in the lung tissue of obese ovalbumin (OVA)-sensitized male and female rats.. The rats were divided into eight groups (n = 5 per group) as follows: female and male rats fed with normal diet (FND and MND, respectively), female and male OVA-sensitized rats fed with normal diet (F-OND and M-OND, respectively), female and male rats fed with high-fat diet (F-HFD and M-HFD, respectively), female and male OVA-sensitized rats fed with high-fat diet (F-OHFD and M-OHFD, respectively). All rats were fed with a high-fat diet or standard pelts for 8 weeks, and for another 4 weeks, they were sensitized by OVA or saline. At the end of the study, lung tissue NF-kB protein level was assessed, and ER stress markers genes expression was determined by Real Time-PCR.. OVA-sensitization and diet-induced obesity caused the curve of methacholine concentration-response to shift to the left. In addition, the results indicated that the EC50 (the effective concentration of methacholine generating 50% of peak response) in F-OHFD rats was statistically lower than that of the M-OHFD group (p < 0.05). Moreover, the results showed that diet-induced obesity increased the expression of ATF4, ATF6, GRP78, XBP-1, and CHOP as well as the protein level of NF-kB in this experimental model of asthma, markedly in the F-OHFD group.. The results suggest that ER stress may be involved in the pathogenesis of asthma observed in obese OVA-sensitized rats, especially in the female animals.

Topics: Animals; Asthma; Diet, High-Fat; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Female; Gene Expression Regulation; HSP70 Heat-Shock Proteins; Leptin; Lung; Male; Membrane Proteins; Methacholine Chloride; NF-kappa B; Obesity; Ovalbumin; Rats; Rats, Wistar; Signal Transduction; Time Factors

In this study, a mice model of obesity-asthma was established. We investigated the correlation between oxidative stress and NF-κB signaling pathway in the lung tissues, together with the effects of acetylcysteine. The animals were fed on a high-fat diet, and then ovalbumin (OVA) sensitization was utilized to establish the obesity-asthma model. N-acetylcysteine was used to treat asthma, animals treated with budesonide served as control. The malondialdehyde (MDA) in the lung tissues was determined, together with the activity of glutathione (GSH). EMAS assay was utilized to measure the nuclear factor-κB-P65 (NF-κB-P65) in lung tissues. Western blot analysis was performed to determine the expression of inhibitor kappa B-α (IκB-α) and inhibitor kappa B kinase-β (IKK-β). The MDA in the asthma groups showed significantly elevation (P < 0.01), and the GSH showed significant decrease (P < 0.01), especially in the obesity-asthma group. The efficiency of N-acetylcysteine was superior to that of the budesonide in the decline of MDA and elevation of GSH (P < 0.01). In both asthma groups, the expression of IKK-β and transcription of NF-κB-P65 in the lung tissues showed significant elevation (P < 0.01), and IκB-α showed significant decline (P < 0.01), especially in the obesity-asthma group. There was decline of IKK-β and NF-κB-P65 and elevation of IκB-α in the N-acetylcysteine group, which was even significantly in the Budesonide group (P < 0.01). There was a positive correlation between MDA and NF-κB activation in the lung tissues in all the asthma groups and treatment groups (P < 0.05). Obesity-asthma mice showed higher oxidative stress and activation of NF-κB compared with that of the asthma mice. There was a positive correlation between MDA and NF-κB activation in the lung tissues in the asthma groups. N-acetylcysteine was more effective in reducing the oxidative stress compared to the budesonide.

Topics: Acetylcysteine; Animals; Asthma; Female; Glutathione; I-kappa B Kinase; Lung; Malondialdehyde; Mice; Mice, Inbred C57BL; Mice, Obese; NF-kappa B; NF-KappaB Inhibitor alpha; Obesity; Ovalbumin; Oxidative Stress; Phosphorylation; Signal Transduction; Tumor Necrosis Factor-alpha

Inflammatory diseases of the bile ducts like primary sclerosing colangitis (PSC) are characterized by a robust cellular response targeting the biliary epithelium leading to chronic inflammation and fibrosis. Driving fibro-inflammatory diseases, NOD-like receptors such as NLRP3 have been identified as a central component to immune-mediated pathology. However, to date the role of NLRP3 in biliary diseases has been poorly explored. Here, we addressed the role of NLRP3 in the OVAbil mouse model of antigen-mediated cholangitis. As obesity continues to spread worldwide, we also evaluated the NLRP3 response in experimental cholangitis after high-fat diet exposure. We compared the extent of histopathological liver damage between OVAbil and OVAbilxNLRP3-/- mice after either a standard chow or a high-fat diet. Infiltrating immune cells were characterized by flow cytometry and levels of cytokines, chemokines and liver enzymes in blood samples were analyzed at the end of the experiment. We observed a more severe histopathological phenotype of cholangitis in absence of NLRP3, characterized by loss of bile ducts and larger inflammatory foci and higher levels of IL- 6 and CXCL10 as compared with NLRP3 sufficient mice. This phenotype was further exaggerated in the context of obesity, where cholangitis induced in NLRP3-deficient obese mice resulted in further exacerbated histopathology and increased levels of IL-13 and TNFα, suggesting a diet-specific profile. The absence of NLRP3 caused a supressed IL-17 response. In summary, our data suggest that activation of NLRP3 attenuates this antigen-mediated OVAbil model of cholangitis.

Topics: Animals; Antigens; Bile Ducts, Intrahepatic; Chemokine CXCL10; Cholangitis; Disease Models, Animal; Inflammation Mediators; Interleukin-6; Male; Mice, Inbred C57BL; Mice, Knockout; NLR Family, Pyrin Domain-Containing 3 Protein; Obesity; Ovalbumin; Severity of Illness Index; Signal Transduction

Numerous population studies conducted worldwide indicate that the prevalence of asthma is higher in obese versus lean individuals. It has been reported that sensitized lean mice has a better recovery of lung inflammation in asthma. Extracellular matrix (ECM) plays an essential role in the structural support of the lungs regulating the airways diameter, thus preventing its collapse during expiration. ECM renewal by metalloproteinase (MMPs) enzymes is critical for pulmonary biology. There seems to be an imbalance of MMPs activity in asthma and obesity, which can impair the lung remodeling process. In this study, we characterized the pulmonary ECM of obese and lean mice, non-sensitized and sensitized with ovalbumin (OVA). Pharmacological intervention was performed by using anti-TNF-α, and MMP-8 and MMP-9 inhibitors in obese and lean sensitized mice. Activity of MMPs was assessed by gelatinase electrophorese, western blotting and zymogram in situ. Unbalance of MMP-2, MMP-8, MMP-9 and MMP-12 was detected in lung tissue of OVA-sensitized obese mice, which was accompanied by high degradation, corroborating an excessive deposition of types I and III collagen in pulmonary matrix of obese animals. Inhibitions of TNF-α and MMP-9 reduced this MMP imbalance, clearly suggesting a positive effect on pulmonary ECM. Obese and lean mice presented diverse phenotype of asthma regarding the ECM compounds and the inhibition of MMPs pathway could be a good alternative to regulate the activity in ECM lungs of asthmatic obese individuals.

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; Extracellular Matrix; Inflammation; Lung; Male; Matrix Metalloproteinase 8; Matrix Metalloproteinase 9; Metalloproteases; Mice; Mice, Inbred C57BL; Obesity; Ovalbumin; Protease Inhibitors; Tumor Necrosis Factor-alpha

The present study aimed to investigate the role of microRNA-146a and its adapter proteins [interleukin-1 receptor-associated kinase 1 (IRAK1) and tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6)] in the pathogenesis of ovalbumin (OVA)-sensitized rats in association with the diet-induced obesity condition. Twenty male Wistar rats were divided into four groups: control with normal diet (ND), OVA-sensitized with normal diet (S + ND), high-fat diet (HFD), and OVA-sensitized with high-fat diet (S + HFD). All the animals were fed for 8 weeks with standard pelts or high-fat diet, and were then sensitized and challenged with OVA or saline for another 4 weeks. The tracheal responsiveness to methacholine, serum protein levels, and lipid profile levels was measured by the ELISA method. Moreover, the gene expression level of microRNA-146a (miR-146a) was measured in the lung tissue of the rats using the real-time PCR method. Maximum response to methacholin increased in the S + HFD group in compared with ND, S + ND, and HFD groups (P < 0.05 to P < 0.001). Moreover, in the S + HFD group the mRNA expression levels of miRNA-146a increased in the lung tissue (P < 0.001). In addition, the protein analysis results showed that IRAK1, TRAF6, NF-kB, and IL-1β protein levels were high in the S + HFD group compared to the ND and HFD groups; however, in compared with the S + ND group, only the IL-1β protein level was higher in the S + HFD group (P < 0.05). These results suggest that a defect in the NF-kB-miR-146a negative feedback loop may be involved in the pathogenesis of obesity associated with OVA-sensitized condition. © 2018 BioFactors, 45(1):75-84, 2019.

Topics: Allergens; Animals; Bronchial Provocation Tests; Diet, High-Fat; Feedback, Physiological; Gene Expression Regulation; Immunization; Interleukin-1 Receptor-Associated Kinases; Interleukin-1beta; Lung; Male; Methacholine Chloride; MicroRNAs; NF-kappa B; Obesity; Ovalbumin; Rats; Rats, Wistar; Signal Transduction; TNF Receptor-Associated Factor 6

Epidemiological and clinical studies have demonstrated a close association between obesity and asthma. The current study investigated the effect of high-fat diet on tracheal responsiveness to methacholine and insulin resistance in ovalbumin (OVA) sensitized male and female rats. The rats were divided into eight groups (n=6 per group): female with the normal diet (F+ND), male with the normal diet (M+ND), female OVA-sensitized with the normal diet (F+SND), male OVA-sensitized with the normal diet (M+SND), female with high-fat diet (F+HFD), male with high-fat diet (M+HFD), female OVA-sensitized with high-fat diet (F+SHFD), and male OVA-sensitized with high-fat diet (M+SHFD). All rats were fed for 8 weeks with high-fat diet or standard pelts, and for another 4 weeks, they were sensitized with OVA or saline. At the end of the study, the tracheal responsiveness to methacholine, serum insulin, and blood glucose levels was measured. Also, insulin resistance indexes were determined. OVA-sensitization and diet-induced obesity caused the curve of methacholine concentration response to shifting to the left. In addition, results indicated that the EC50 (the effective concentration of methacholine generating 50% of peak response) in F+SHFD rats was statistically lower than M+SHFD group (p<0.05). Moreover, insulin resistance was higher in the F+SHFD than the M+SHFD group (p<0.001). These results suggest that insulin resistance and metabolic syndrome may be involved in the pathogenesis of obesity associated with OVA-sensitized rats condition, especially in female animals.

Topics: Allergens; Animals; Asthma; Blood Glucose; Bronchoconstrictor Agents; Diet, High-Fat; Disease Models, Animal; Female; Insulin; Insulin Resistance; Male; Methacholine Chloride; Obesity; Ovalbumin; Rats, Wistar; Trachea

Many studies have shown a close relationship between obesity and asthma severity. In the present study, the effects of diet-induced obesity were examined on airway responsiveness to methacholine in addition to visfatin level in female Wistar rats' tracheae after sensitization with ovalbumin. The rats were divided into four groups: control with normal diet (ND), ovalbumin (OVA)-sensitized with normal diet (S + ND), high-fat diet (HFD), and OVA-sensitized with a high-fat diet (S + HFD). The animals were fed for 8 weeks with standard pelts or high-fat diet and then sensitized and challenged with OVA or saline for another 4 weeks. At the end of the study, the tracheae were isolated and assessed for airway responsiveness and visfatin protein levels. Diet-induced obesity groups developed increased weight and obesity indices (p < 0.001). After sensitization with OVA and diet-induced obesity, there were marked leftward shifts in methacholine concentration-response curves in S + HFD group compared to other groups. Also, maximum response was the highest (p < 0.05 to p < 0.001), EC

Topics: Animals; Diet, High-Fat; Female; Inflammation; Methacholine Chloride; Nicotinamide Phosphoribosyltransferase; Obesity; Ovalbumin; Rats; Rats, Wistar; Respiratory Hypersensitivity; Sensitivity and Specificity; Trachea

Mucus production and hypersecretion are important pathophysiological features of asthma. Airway mucus secretion is more serious in obese asthma. Therefore, it is of great significance to elucidate the mechanism of asthma airway mucus high secretion in improving the control of asthma and the prognosis of obese asthmatic patients.. Obese asthmatic mice model was established to test the airway resistance and mucin secretion by hematoxylin-eosin (HE) staining. Munc18b and Muc5ac expression levels were determined by Western-blotting. Munc18b conditioned knockout mice were adopted to explore the mechanism of Muc5ac high secretion.. The mice weight increased in obese asthmatic model accompanied by elevated airway resistance. HE staining showed enhanced mucin secretion, which was correlated to weight and airway resistance. Munc18b and Muc5ac expressions significant upregulated in an obese asthmatic mouse model compared with normal control. Muc5ac expression failed to show elevation in Munc18b conditioned knockout mice.. Muc5ac high secretion was positively correlated with Munc18b upregulation in obese asthma. Munc18b participated in inducing Muc5ac high expression.

Topics: Animals; Asthma; Disease Models, Animal; Mice; Mice, Inbred C57BL; Mice, Knockout; Mucin 5AC; Munc18 Proteins; Obesity; Ovalbumin; Up-Regulation

The consumption of Westernized diets leads to hyperphagia and obesity, as well as intestinal alterations. In the present study, we evaluated the effect of the administration of a grape seed proanthocyanidin extract (GSPE) at different time points on the modulation of intestinal barrier function (intestinal permeability and metabolic endotoxemia), in rats with high-fat/high-carbohydrate diet-induced obesity. Animals were fed a cafeteria diet (CAF) supplemented with a preventive (PRE-CAF) or simultaneously intermittent (SIT-CAF) GSPE treatment (500 mg/kg bw). Changes in the plasma levels of an orally administered marker of intestinal permeability (ovalbumin, OVA), lipopolysaccharide (LPS) and tumor necrosis factor-α (TNF-α) were analyzed after animals were fed the obesogenic diet for 8, 12 and 17 weeks. In addition, ex vivo variations in transepithelial electrical resistance (TEER), the expression of tight junction (TJ) genes and the activity of myeloperoxidase (MPO) in the small and large intestines were monitored at the end of the experiment. The CAF diet increased OVA, LPS, MPO and TNF-α levels, accompanied by decreased TEER values in the small and large intestines. Interestingly, both GSPE treatments prevented these detrimental effects of the CAF diet, being the SIT-CAF group the most effective after 17 weeks of diet intervention. For the first time, this study provides evidence of the ameliorative effect of a proanthocyanidin extract, administered before or together with an obesogenic diet, on barrier dysfunction, as measured by intestinal permeability and metabolic endotoxemia.

Topics: Administration, Oral; Animals; Diet, High-Fat; Dietary Supplements; Endotoxemia; Female; Gene Expression Regulation; Grape Seed Extract; Intestinal Mucosa; Intestines; Lipopolysaccharides; Obesity; Ovalbumin; Permeability; Proanthocyanidins; Rats, Wistar; Tight Junction Proteins; Tumor Necrosis Factor-alpha

To investigate the effects of diet-induced obesity on the expression of nuclear factor-κB (NF-κB) and visfatin messenger RNA in male Wistar rats' tracheae after sensitization with ovalbumin (OVA).. Twenty male Wistar rats were divided into 4 groups (n = 5 for each group), which included a control group fed a normal diet (ND) and groups fed normal diet, OVA-sensitized (S+ND); high-fat diet (HFD) only (diet-induced obesity); and high-fat diet, OVA-sensitized (S+HFD). All animals were fed for 8 weeks with standard chow or a high-fat diet, and then were sensitized and challenged with OVA or saline for another 4 weeks as per the above groups. The rats were anesthetized, after which the necks were exposed and the tracheae isolated and examined for expression levels of NF-κB and visfatin mRNA with the real-time polymerase chain reaction method. Data were compared between the different groups using one-way analysis of variance.. The expression level of NF-κB mRNA in the S+HFD group was 2.67, which was statistically higher than the levels in the ND (0.96; p = 0.001), S+ND (1.86; p = 0.05), and HFD (1.26; p = 0.001) groups. Also, the visfatin mRNA expression level in the S+HFD group was 4.21, which was higher than the levels in the ND (0.92), S+ND (1.79), and HFD (2.20) (p = 0.001) groups.. In this study, the expression levels of NF-κB and visfatin were markedly higher in the S+HFD group in comparison to the other groups. These findings indicate that alternative signaling pathways might be activated in diet-induced obesity associated with the OVA-sensitized animal model and could be responsible for possible altered sensitization phenotype.

Topics: Analysis of Variance; Animals; Body Weight; Cholesterol; Diet, High-Fat; Disease Models, Animal; Male; NF-kappa B; Nicotinamide Phosphoribosyltransferase; Obesity; Ovalbumin; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Trachea

Clinical and epidemiological studies indicate that obesity affects the development and phenotype of asthma by inducing inflammatory mechanisms in addition to eosinophilic inflammation. The aim of this study was to assess the effect of obesity on allergic airway inflammation and T helper type 2 (Th2) immune responses using an experimental model of asthma in BALB/c mice. Mice fed a high-fat diet (HFD) for 10 weeks were sensitized and challenged with ovalbumin (OVA), and analyses were performed at 24 and 48 h after the last OVA challenge. Obesity induced an increase of inducible nitric oxide synthase (iNOS)-expressing macrophages and neutrophils which peaked at 48 h after the last OVA challenge, and was associated with higher levels of interleukin (IL)-4, IL-9, IL-17A, leptin and interferon (IFN)-γ in the lungs. Higher goblet cell hyperplasia was associated with elevated mast cell influx into the lungs and trachea in the obese allergic mice. In contrast, early eosinophil influx and lower levels of IL-25, thymic stromal lymphopoietin (TSLP), CCL11 and OVA-specific immunoglobulin (IgE) were observed in the obese allergic mice in comparison to non-obese allergic mice. Moreover, obese mice showed higher numbers of mast cells regardless of OVA challenge. These results indicate that obesity affects allergic airway inflammation through mechanisms involving mast cell influx and the release of TSLP and IL-25, which favoured a delayed immune response with an exacerbated Th1, Th2 and Th17 profile. In this scenario, an intense mixed inflammatory granulocyte influx, classically activated macrophage accumulation and intense mucus production may contribute to a refractory therapeutic response and exacerbate asthma severity.

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Eosinophils; Female; Immunoglobulin E; Inflammation; Leukocyte Count; Lung; Macrophages; Mice; Mice, Inbred BALB C; Neutrophils; Nitric Oxide Synthase Type II; Obesity; Ovalbumin; T-Lymphocytes, Helper-Inducer; Thymic Stromal Lymphopoietin

Obesity is accompanied with systemic inflammation and pre-conditions to severe alterations in liver environment and functions. So far, it remains elusive to which extent obesity modulates immune responses during hepatotropic virus infections as well as in autoimmune hepatitis. In this study we investigated the influence of obesity on the intrahepatic immune response, in particular on the function of CD8 T cells as the crucial players in clearance of virus infected hepatocytes.. We established high fat induced obesity in transgenic mouse models with hepatocyte specific expression of a model antigen (Ova). We investigated the immune response upon adoptive transfer of antigen specific T cells and in mice with continuous thymic output of antigen specific T cells, mimicking the situations upon acute infection and autoimmunity, respectively.. Irrespective of the metabolic condition, adoptive T cell transfer resulted in a transient hepatitis with no obvious differences concerning the acute T cell response. In the situation of autoimmunity, we observed a transient hepatitis in lean mice, whereas an extended hepatitis with a reduced antigen clearance capacity was found in obese mice.. Our results demonstrate that obesity affects T cell function and increases the severity of autoimmune hepatitis while it has no impact on the acute T cell response.

Topics: Adoptive Transfer; Animals; Autoimmunity; CD8-Positive T-Lymphocytes; Diet; Diet, High-Fat; Hepatocytes; Liver; Liver Function Tests; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Mice, Transgenic; Obesity; Ovalbumin; Thymus Gland

Allergic mice show a reduction in body weight and adiposity with a higher inflammatory response in the adipose tissue similar to obese fat tissue. This study aimed to evaluate whether the low-grade inflammatory milieu of mice with diet-induced mild obesity interferes with the allergic response induced by ovalbumin (OVA).. BALB/c mice were divided into four groups: 1) non-allergic (OVA-) mice fed chow diet, 2) allergic (OVA+) mice fed chow diet, 3) OVA- mice fed high-refined carbohydrate-containing (HC) diet, and 4) OVA+ mice fed HC diet. After 5 wk, allergic groups were sensitized with OVA and received a booster 14 d later. All groups received an oral OVA challenge 7 d after the booster.. Allergic groups showed increased serum levels of total IgE, anti-OVA IgE, and IgG1; a high disease activity index score; aversion to OVA; and increased intestinal eosinophil infiltration. Non-allergic mild-obese mice also showed aversion to OVA and an increased number of eosinophils in the proximal jejunum. After the allergic challenge, OVA+ mice fed chow diet showed weight loss and lower adiposity in several adipose tissue depots. OVA+ mice fed HC diet showed a loss of fat mass only in the mesenteric adipose tissue. Furthermore, increased levels of TNF, IL-6, and IL-10 were observed in this tissue.. Our data show that mild-obese allergic mice do not present severe pathologic features of food allergy similar to those exhibited by lean allergic mice. Mild obesity promoted by HC diet ingestion causes important intestinal disorders that appear to modulate the inflammatory response during the antigen challenge.

Topics: Adipose Tissue; Adiposity; Animals; Body Weight; Diet; Dietary Carbohydrates; Food Hypersensitivity; Glucose Tolerance Test; Immunoglobulin E; Immunoglobulin G; Inflammation; Insulin Resistance; Interleukin-10; Interleukin-6; Intestinal Mucosa; Intestines; Leukocyte Count; Male; Mice; Mice, Inbred BALB C; Obesity; Ovalbumin

Obese patients with asthma respond poorly to conventional asthma medications, resulting in severe symptoms and poor prognosis. Roflumilast, a phosphodiesterase-4 inhibitor that lowers the levels of various substances that are implicated in obese subjects with asthma, may be effective in the treatment of those subjects. We evaluated the potential of roflumilast as a novel therapeutic agent for obese subjects with asthma. We designed three models: diet-induced obesity (DIO); DIO with ovalbumin (OVA); and OVA. We fed C57BL/6J mice a high-fat diet for 3 months with or without OVA sensitization and challenge. Roflumilast or dexamethasone was administered orally three times at 2-day intervals in the last experimental week. Airway hyperresponsiveness resulting from DIO significantly improved in the roflumilast-treated group compared with the dexamethasone-treated groups. Although DIO did not affect the cell proliferation in bronchoalveolar lavage fluid, increased fibrosis was seen in the DIO group, which significantly improved from treatment with roflumilast. DIO-induced changes in adiponectin and leptin levels were improved by roflumilast, whereas dexamethasone aggravated them. mRNA levels and proteins of TNF-α, transforming growth factor-β, IL-1β, and IFN-γ increased in the DIO group and decreased with roflumilast. The reactive oxygen species levels were also increased in the DIO group and decreased by roflumilast. In the DIO plus OVA and OVA models, roflumilast improved Th1 and Th2 cell activation to a greater extent than dexamethasone. Roflumilast is significantly more effective than dexamethasone against airway hyperresponsiveness caused by DIO in the murine model. Roflumilast may represent a promising therapeutic agent for the treatment of obese patients with asthma.

Topics: Adiponectin; Aminopyridines; Animals; Benzamides; Cell Proliferation; Cyclopropanes; Cytokines; Diet; Disease Models, Animal; Leptin; Mice, Inbred C57BL; Models, Biological; Obesity; Ovalbumin; Pulmonary Fibrosis; Reactive Oxygen Species; Respiratory Hypersensitivity; T-Lymphocytes

The incidence of obesity has risen to epidemic proportions in recent decades, most commonly attributed to an increasingly sedentary lifestyle, and a 'western' diet high in fat and low in fibre. Although non-allergic asthma is a well-established co-morbidity of obesity, the influence of obesity on allergic asthma is still under debate. Allergic asthma is thought to result from impaired tolerance to airborne antigens, so-called respiratory tolerance. We sought to investigate whether a diet high in fats affects the development of respiratory tolerance. Mice fed a high fat diet (HFD) for 8 weeks showed weight gain, metabolic disease, and alteration in gut microbiota, metabolites and glucose metabolism compared to age-matched mice fed normal chow diet (ND). Respiratory tolerance was induced by repeated intranasal (i.n.) administration of ovalbumin (OVA), prior to induction of allergic airway inflammation (AAI) by sensitization with OVA in alum i.p. and subsequent i.n. OVA challenge. Surprisingly, respiratory tolerance was induced equally well in HFD and ND mice, as evidenced by decreased lung eosinophilia and serum OVA-specific IgE production. However, in a pilot study, HFD mice showed a tendency for impaired activation of airway dendritic cells and regulatory T cells compared with ND mice after induction of respiratory tolerance. Moreover, the capacity of lymph node cells to produce IL-5 and IL-13 after AAI was drastically diminished in HFD mice compared to ND mice. These results indicate that HFD does not affect the inflammatory or B cell response to an allergen, but inhibits priming of Th2 cells and possibly dendritic cell and regulatory T cell activation.

Topics: Allergens; Alum Compounds; Animals; B-Lymphocytes; Dendritic Cells; Diet, High-Fat; Dietary Fats; Eosinophilia; Female; Immune Tolerance; Immunoglobulin E; Interleukin-13; Interleukin-5; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Obesity; Ovalbumin; Respiratory Hypersensitivity; Respiratory System; T-Lymphocytes, Regulatory

Obesity is a known risk factor for allergic asthma. It has been recognized as a key player in the pathogenesis of several inflammatory disorders via activation of macrophages, which is also vital to the development of allergic asthma. We investigated the mechanism of obesity-related asthma and whether treating obesity through exercise or diet ameliorates the severity of asthma in the obesity-related asthma model. We generated diet-induced obesity (DIO) in C57BL/6 mice by high-fat-feeding and ovalbumin-induced asthma (lean-OVA or DIO-OVA). The DIO-OVA mice were then treated with tumor necrosis factor (TNF)-α neutralizing antibody as a TNF-α blockade or a Cl2MDP-containing liposome to induce an alveolar macrophage deficiency. To treat obesity, the DIO-OVA mice were under dietary restrictions or exercised. The pathophysiological and immunological responses were analyzed. Airway hyperresponsiveness (AHR), serum IgE and TNF-α levels in the lung tissue increased in the DIO-OVA mice compared to the lean-OVA mice. Both the TNF-α blockade and depletion of alveolar macrophages in the DIO-OVA mice decreased AHR compared to the DIO-OVA mice. Treating obesity by exercise or through dietary means also reduced pulmonary TNF-α levels and AHR in the DIO-OVA mice. These results suggest that restoring normal body weight is an appropriate strategy for reducing TNF-α levels, and controlling inflammation may help improve asthma severity and control in obesity-related asthma.

Topics: Animals; Antibodies, Neutralizing; Body Weight; Clodronic Acid; Diet Therapy; Diet, High-Fat; Disease Models, Animal; Exercise Therapy; Macrophages, Alveolar; Mice; Obesity; Ovalbumin; Respiratory Hypersensitivity; Tumor Necrosis Factor-alpha

The present study was designed to assess the potential of supplementation of diet with Flaxseed (Linum usitatissimum, L.) oil (FXO), on obesity-related inflammation and reversal of obesity-induced insulin resistance. Swiss Albino mice, C57bl/6 mice and co-culture of 3T3-L1 adipocytes - RAW 264.7 macrophages to mimick obese adipose tissue environment were used for the study. Oral gavage of FXO at concentrations of 4, 8 or 16 mg/kg body weight (bwt) for 4 weeks or high-fat diet (HFD, 60% energy as fat) supplemented with dietary FXO (4, 8 or 16 mg/kg bwt) was given to the mice. FXO was characterised using gas chromatography - mass spectrometry. FXO supplemented HFD-fed mice (4 mg/kg bwt exhibited reduced adiposity index, serum glucose levels and triglycerides (8 and 16 mg/kg bwt) and improvement in insulin sensitisation (4, 8 and 16 mg/kg bwt) when compared with HFD mice. The co-culture showed a dose-dependent shift in cytokines towards anti-inflammatory (IL-4) state, with a decrease in pro-inflammatory TNF-α (p < 0.05). For immunomodulatory studies a dose-dependent increase (p < 0.05) was observed in antigen-specific levels of Th2 (IL-4) cytokine, serum anti-ova IgG1 and IgE levels. Suppression in anti-ova IgG2a, IgG2b, and IgG3 and antigen-specific Th1 cytokines like TNF-α and IFN-γ significantly (p < 0.05) was observed at 16 mg/kg bwt dosage. The results indicate that FXO exhibits an anti-inflammatory immunomodulatory potential and may partially relieve symptoms of obesity-associated insulin resistance.

Topics: 3T3-L1 Cells; Adiposity; Animals; Anti-Inflammatory Agents; Coculture Techniques; Cytokines; Diet, High-Fat; Dose-Response Relationship, Drug; Dose-Response Relationship, Immunologic; Drug Evaluation, Preclinical; Glucose Tolerance Test; Hypersensitivity, Delayed; Immunoglobulin E; Immunoglobulin G; Immunologic Factors; Insulin Resistance; Linseed Oil; Lipids; Liver; Lymphocyte Activation; Lymphoid Tissue; Male; Mice; Mice, Inbred C57BL; Obesity; Ovalbumin; Phytotherapy; RAW 264.7 Cells; Th1 Cells; Th2 Cells

Atopic, obese asthmatics exhibit airway obstruction with variable degrees of eosinophilic airway inflammation. We previously reported that mice obese as a result of a genetic deficiency in either leptin (ob/ob mice) or the long isoform of the leptin receptor (db/db mice) exhibit enhanced airway obstruction in the presence of decreased numbers of bronchoalveolar lavage fluid (BALF) eosinophils compared with lean, wild-type mice following antigen (ovalbumin; OVA) sensitization and challenge. To determine whether the genetic modality of obesity induction influences the development of OVA-induced airway obstruction and OVA-induced pulmonary inflammation, we examined indices of these sequelae in mice obese as a result of a genetic deficiency in carboxypeptidase E, an enzyme that processes prohormones and proneuropeptides involved in satiety and energy expenditure (Cpe(fat) mice). Accordingly, Cpe(fat) and lean, wild-type (C57BL/6) mice were sensitized to OVA and then challenged with either aerosolized PBS or OVA. Compared with genotype-matched, OVA-sensitized and PBS-challenged mice, OVA sensitization and challenge elicited airway obstruction and increased BALF eosinophils, macrophages, neutrophils, IL-4, IL-13, IL-18, and chemerin. However, OVA challenge enhanced airway obstruction and pulmonary inflammation in Cpe(fat) compared with wild-type mice. These results demonstrate that OVA sensitization and challenge enhance airway obstruction in obese mice regardless of the genetic basis of obesity, whereas the degree of OVA-induced pulmonary inflammation is dependent on the genetic modality of obesity induction. These results have important implications for animal models of asthma, as modeling the pulmonary phenotypes for subpopulations of atopic, obese asthmatics critically depends on selecting the appropriate mouse model.

Topics: Airway Obstruction; Airway Resistance; Animals; Antigens; Biomarkers; Bronchoalveolar Lavage Fluid; Carboxypeptidase H; Disease Models, Animal; Female; Genotype; Immunoglobulins; Inflammation Mediators; Lung; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Ovalbumin; Phenotype; Pneumonia; Time Factors

A positive relationship between obesity and asthma has been well documented. The AMP-activated protein kinase (AMPK) activator metformin reverses obesity-associated insulin resistance (IR) and inhibits different types of inflammatory responses. This study aimed to evaluate the effects of metformin on the exacerbation of allergic eosinophilic inflammation in obese mice. Male C57BL6/J mice were fed for 10 weeks with high-fat diet (HFD) to induce obesity. The cell infiltration and inflammatory markers in bronchoalveolar lavage (BAL) fluid and lung tissue were evaluated at 48 h after ovalbumin (OVA) challenge. HFD obese mice displayed peripheral IR that was fully reversed by metformin (300 mg/kg/day, two weeks). OVA-challenge resulted in higher influx of total cell and eosinophils in lung tissue of obese mice compared with lean group. As opposed, the cell number in BAL fluid of obese mice was reduced compared with lean group. Metformin significantly reduced the tissue eosinophil infiltration and prevented the reduction of cell counts in BAL fluid. In obese mice, greater levels of eotaxin, TNF-α and NOx, together with increased iNOS protein expression were observed, all of which were normalized by metformin. In addition, metformin nearly abrogated the binding of NF-κB subunit p65 to the iNOS promoter gene in lung tissue of obese mice. Lower levels of phosphorylated AMPK and its downstream target acetyl CoA carboxylase (ACC) were found in lung tissue of obese mice, which were restored by metformin. In separate experiments, the selective iNOS inhibitor aminoguanidine (20 mg/kg, 3 weeks) and the anti-TNF-α mAb (2 mg/kg) significantly attenuated the aggravation of eosinophilic inflammation in obese mice. In conclusion, metformin inhibits the TNF-α-induced inflammatory signaling and NF-κB-mediated iNOS expression in lung tissue of obese mice. Metformin may be a good pharmacological strategy to control the asthma exacerbation in obese individuals.

Topics: AMP-Activated Protein Kinases; Animals; Asthma; Blotting, Western; Bronchoalveolar Lavage Fluid; Diet, High-Fat; Enzyme Inhibitors; Eosinophils; Guanidines; Hypoglycemic Agents; Inflammation; Insulin Resistance; Lung; Male; Metformin; Mice; Mice, Inbred C57BL; Nitric Oxide; Nitric Oxide Synthase Type II; Obesity; Ovalbumin; Promoter Regions, Genetic; Protein Binding; Transcription Factor RelA; Tumor Necrosis Factor-alpha

Asthma and obesity are growing epidemics in the world. It is well established that obesity worsens the asthma outcomes. High-fat diet-induced obesity in mice exacerbates the pulmonary eosinophilic inflammation. We have used wild-type (WT) and ob/ob mice to further explore the mechanisms by which obesity aggravates the pulmonary eosinophilic inflammation. The eosinophil (EO) number in bronchoalveolar lavage (BAL) fluid, lung tissue, blood, and bone marrow were evaluated at 24, 48, and 72 h after ovalbumin (OVA) challenge in sensitized mice. The basal EO number (phosphate-buffered saline (PBS)-instilled mice) in lung tissue was about 3.5-fold greater in ob/ob compared with WT mice. OVA challenge in ob/ob mice promoted an EO accumulation into the lung that was accompanied by a lower emigration to airways lumen (BAL fluid) in comparison with WT mice. OVA challenge also markedly elevated the number of mature and immature EO in bone marrow of ob/ob mice at 24 h compared with WT group. Blood EO at 48 h was markedly greater in ob/ob mice. Tumor necrosis factor (TNF)-α and interleukin (IL)-10 levels in BAL fluid were significantly higher in ob/ob mice, whereas no changes for IL-5 and eotaxin were found. The IL-6 levels were significantly lower in ob/ob mice. In conclusion, OVA challenge in ob/ob obese mice potentiates eosinophilopoiesis and promotes an accumulation of EO into the lung tissue, delaying their transit to airways lumen. The longer EO remain into the lung tissue is likely to contribute, at least in part, to the asthma worsened by obesity.

Topics: Allergens; Animals; Bone Marrow; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Eosinophils; Female; Inflammation; Interleukin-6; Leptin; Leukocyte Count; Lung; Male; Mice; Mice, Obese; Obesity; Ovalbumin; Respiratory Hypersensitivity

A number of studies have shown an association between obesity and asthma. Controversy remains on the mechanisms supporting this association. In this study we aimed to assess neurogenic inflammation in a model of diet-induced obesity and allergen-challenged mice.. High fat diet-induced (HFD) obese Balb/c mice were sensitized and challenged with ovalbumin (OVA). Glucose, insulin, OVA-specific IgE and substance P (SP), and the main tachykinin involved in neurogenic inflammation, were quantified in sera. Cell counts were performed in bronchoalveolar lavage fluid (BALF). The extent of peribronchial infiltrates was estimated on lung tissue sections and inflammation was score based on inflammatory cell counts surrounding the bronchi.. Obesity per se and allergen-sensitization per se increased serum SP (P = .027, P = .004, respectively). Further increased was observed in obese-sensitized mice (P = .007). Obese-sensitized mice also showed higher insulin (P = .0016), OVA-specific IgE (P = .016), peribronchial inflammatory score (P = .045), and tendency for higher glycemia. The interaction of obesity and asthma on SP levels was confirmed (P = .005, R(2) = 0.710). SP was positively correlated with metabolic (glycemia, r = 0.539, P = .007) and allergic inflammation parameters (BALF eosinophils, r = 0.445, P = 0.033; BALF mast cells, r = 0.574, P = .004; peribronchial inflammation score, r = 0.661, P < .001; and OVA-specific IgE, r = 0.714, P < .001).. Our findings provide support to the neurogenic inflammation link between obesity and asthma in mice. These two conditions independently increased SP and the presence of both pathologies further increased this level. Neurogenic inflammation may be a previously unrecognized mechanism beyond the obese-asthma phenotype. Further studies are need to confirm this role of SP in human obesity-asthma association.

Topics: Allergens; Animals; Asthma; Blood Glucose; Bronchoalveolar Lavage Fluid; Cell Count; Diet, High-Fat; Immunoglobulin E; Insulin; Lung; Mice; Mice, Inbred BALB C; Mice, Obese; Neurogenic Inflammation; Obesity; Ovalbumin; Substance P; Tachykinins

Obesity is associated with deterioration in asthma outcomes. Although airways eosinophil accumulation is characteristic of lung allergic diseases, little is known about the influence of obesity on the allergic eosinophil trafficking from bone marrow to lung tissues, and recruitment to airways lumen. Here, we have assessed the effects of diet-induced obesity on allergic eosinophilic inflammation in mice, examining eosinophil trafficking from bone marrow to airways, and production of T(H)1/T(H)2 cytokines.. C57BL/6 mice fed for 10 weeks with standard chow or high-fat diet were sensitized and challenged with ovalbumin. At 24-96 h post-ovalbumin challenge, bronchoalveolar lavage (BAL) fluid, lung tissue and bone marrow were examined.. The high-fat-fed mice exhibited increased body weight and epididymal fat, glucose intolerance and alterations in lipid profile compared with the lean mice. Obesity markedly elevated serum leptin and lowered adiponectin levels. Ovalbumin challenge in obese mice promoted a markedly higher eosinophil accumulation in bone marrow and connective tissue surrounding the bronchial and bronchiolar segments. Eosinophil number in BAL fluid of obese mice was lower at 24 and 48 h. Levels of interleukin (IL)-5, eotaxin, tumour necrosis factor-alpha and IL-10 in BAL fluid of obese mice were significantly higher than in lean mice.. Diet-induced obesity enhanced eosinophil trafficking from bone marrow to lung tissues, and delayed their transit through the airway epithelium into the airway lumen. Consequently, eosinophils remain longer in lung peribronchiolar segments due to overproduction of T(H)1/T(H)2 cytokines and chemokines.

Topics: Animals; Asthma; Bone Marrow; Bronchi; Bronchoalveolar Lavage Fluid; Chemokine CCL11; Cytokines; Eosinophilia; Eosinophils; Hypersensitivity; Inflammation; Interleukin-10; Interleukin-5; Lung; Lung Diseases; Male; Mice; Mice, Inbred C57BL; Obesity; Ovalbumin; Pneumonia; Tumor Necrosis Factor-alpha

There is a clear link between obesity and metabolic disorders; however, little is known about the effect of obesity on immune function, particularly during an infection. We have previously reported that diet-induced obese mice are more susceptible to morbidity and mortality during influenza infection than lean mice. Obese mice displayed aberrant innate immune responses characterized by minimal induction of interferon (IFN)-alpha/beta, delayed expression of pro-inflammatory cytokines and chemokines, and impaired natural killer cell cytotoxicity. To further examine the abnormal immune response of diet-induced obese mice, we analysed the cellularity of their lungs during influenza virus infection. We found delayed mononuclear cell entry with a marked decrease in dendritic cells (DCs) throughout the infection. Given the critical role of the DC in activating the cell-mediated immune response, we also analysed the functional capacity of DCs from obese mice. We found that, while obesity did not interfere with antigen uptake and migration, it did impair DC antigen presentation. This was probably attributable to an altered cytokine milieu, as interleukin (IL)-2, IL-12, and IL-6 were differentially regulated in the obese mice. Overall, this did not impact the total number of virus-specific CD8(+) T cells that were elicited, but did affect the number and frequency of CD3(+) and CD8(+) T cells in the lung. Thus, obesity interferes with cellular responses during influenza infection, leading to alterations in the T-cell population that ultimately may be detrimental to the host.

Topics: Animals; Antigen Presentation; CD8-Positive T-Lymphocytes; Cells, Cultured; Dendritic Cells; Diet; Immunity, Innate; Influenza A virus; Interleukin-6; Lung; Lymph Nodes; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Orthomyxoviridae Infections; Ovalbumin

Obesity is associated with an increased incidence and severity of asthma, as well as other lung disorders, such as pulmonary hypertension. Adiponectin (APN), an antiinflammatory adipocytokine, circulates at lower levels in the obese, which is thought to contribute to obesity-related inflammatory diseases. We sought to determine the effects of APN deficiency in a murine model of chronic asthma. Allergic airway inflammation was induced in APN-deficient mice (APN(-/-)) using sensitization without adjuvant followed by airway challenge with ovalbumin. The mice were then analyzed for changes in inflammation and lung remodeling. APN(-/-) mice in this model develop increased allergic airway inflammation compared with wild-type mice, with greater accumulation of eosinophils and monocytes in the airways associated with elevated lung chemokine levels. Surprisingly, APN(-/-) mice developed severe pulmonary arterial muscularization and pulmonary arterial hypertension in this model, whereas wild-type mice had only mild vascular remodeling and comparatively less pulmonary arterial hypertension. Our findings demonstrate that APN modulates allergic inflammation and pulmonary vascular remodeling in a model of chronic asthma. These data provide a possible mechanism for the association between obesity and asthma, and suggest a potential novel link between obesity, inflammatory lung disease, and pulmonary hypertension.

Topics: Adiponectin; Airway Resistance; Animals; Asthma; Chemokines; Disease Models, Animal; Disease Susceptibility; Female; Hyperplasia; Hypertension, Pulmonary; Hypoxia; Inflammation; Lung Compliance; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Monocytes; Muscle, Smooth, Vascular; Obesity; Ovalbumin; Pulmonary Artery; Pulmonary Eosinophilia

Epidemiological studies suggest that obesity is associated with the impairment of immunity. However, there is no experimental evidence that obesity prejudices immune responses.. This study was designed to determine the effects of obesity on contact hypersensitivity (CHS) response using a diet-induced obese (DIO) mouse model.. The effect of high fat diet (HFD) on CHS response to trinitrochlorobenzene (TNCB) was assessed by ear swelling, cytokine production, functional analysis of epidermal Langerhans cells, and adoptive transfer of immune cells. Immune response to ovalbumin was also analyzed in DIO mice.. C57BL/6 mice but not BALB/c mice that fed with HFD for 4 weeks or more became obese and showed impaired CHS response, although both strain of mice showed enhanced irritant response to TNCB. CHS response was slightly impaired when C57BL/6 mice fed with HFD for 1 or 2 weeks. This suggests that diet-induced obesity or the HFD itself impairs the CHS response in the susceptible mice. The adoptive transfer of immune cells from DIO mice sensitized with TNCB to naïve mice failed to show vigorous CHS, which suggests dysfunction of an afferent phase of CHS in DIO mice. However, the number and allo-stimulating ability of epidermal Langerhans cells were comparable between DIO mice and lean mice. In addition, the immune response to ovalbumin (delayed type hypersensitivity, and antigen-dependent production of antibodies and cytokine) was preserved in DIO mice.. These results suggest that the diet-induced obesity or the HFD only partially impairs immunity in the susceptible mice.

Topics: Adoptive Transfer; Animals; Cytokines; Dermatitis, Allergic Contact; Dietary Fats; Disease Models, Animal; Edema; Female; Hypersensitivity, Delayed; Langerhans Cells; Leptin; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Obesity; Ovalbumin; Picryl Chloride; Species Specificity; T-Lymphocytes; Time Factors

Epidemiologic data indicate an increased incidence of asthma in the obese.. To determine whether obese mice exhibit augmented pulmonary responses after allergen sensitization and challenge.. Lean, wild-type (C57BL/6), obese ob/ob, and obese db/db mice were sensitized to ovalbumin (OVA), and then challenged with aerosolized OVA or phosphate-buffered saline (PBS). Changes in total pulmonary resistance (Rl) induced by intravenous methacholine were measured by forced oscillation. Blood was collected, bronchoalveolar lavage (BAL) was performed, and lungs were harvested for measurement of cytokine expression by real-time reverse transcription-polymerase chain reaction.. OVA challenge increased baseline Rl in ob/ob, but not wild-type, mice, and airway responsiveness was greater in ob/ob than wild-type mice, regardless of the challenge. Compared with PBS, OVA challenge caused an increase in the number of BAL fluid (BALF) cells, an increase in lung Th2 cytokine expression, and an increase in serum IgE. Significantly fewer BALF cells were recovered from OVA-challenged ob/ob versus wild-type mice, whereas serum IgE levels were elevated significantly more in ob/ob versus wild-type mice. BALF and lung Th2 cytokine expression was not different in ob/ob versus wild-type mice. Airway responsiveness was greater in db/db versus wild-type mice, regardless of the challenge, and OVA caused airway hyperresponsiveness in db/db but not wild-type mice, despite reduced BALF cells in OVA-challenged db/db versus wild-type mice.. These results demonstrate that obesity enhances OVA-induced changes in pulmonary resistance and serum IgE and that these changes are not the result of increased Th2 type airway inflammation.

Topics: Airway Resistance; Animals; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchoconstrictor Agents; Cytokines; Immunization; Immunoglobulin E; Lung; Methacholine Chloride; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Ovalbumin; Receptors, Tumor Necrosis Factor, Type I; Receptors, Tumor Necrosis Factor, Type II; Respiratory Hypersensitivity; Th2 Cells

It is known that immune functions are altered in various ways by obesity. However, changes in the intestinal immune system resulting from obesity remain poorly understood. Oral tolerance is a system that suppresses antigen specific immune responses to orally administrated antigens. The intestinal immune system is intimately associated with the oral tolerance system, that acts to prevent allergic and inflammatory diseases. In this study we investigated the effect of obesity on induction of oral tolerance to ovalbumin (OVA) in an animal model of obesity.. Obese mice induced by a high fat diet and control mice were allowed free access for 3 days to a 1%-ovalbumin (OVA) solution in drinking water. After continuous feeding of the antigen, all the mice were immunized by two intraperitoneal injections of OVA administered 7 days apart.. In the control mice, induction of oral tolerance caused an increase in antigen specific IgG1 levels and a decrease in IgG2a levels. In contrast, the IgG1/IgG2a ratio was reversed in obese mice. OVA-specific IL-2 production was suppressed by antigen feeding in both the control and obese mice; however, suppression of OVA-specific IL-10 was observed only in the control mice. Although OVA-specific IgA and IgM were not affected by antigen feeding, the obese groups of mice had significantly lower titers of antibodies.. These findings suggest that obesity may affect induction of oral tolerance following antigen feeding and that these changes may be related to the inflammatory reaction.

Topics: Animals; Antigens; Diet; Dietary Fats; Immune Tolerance; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Interleukin-10; Interleukin-2; Interleukin-4; Mice; Mouth; Obesity; Ovalbumin; Spleen

Obesity is becoming one of the most serious public health problems in industrialized societies, due to the profound changes in lifestyle, and notably in nutrition. Beside diabetes, cardiovascular diseases or hypertension, increased susceptibility to infection is one of the pathological consequences of being overweight. In this paper, we have assessed the influence of a high-fat diet (HFD) rich in saturated fatty acids on the immune system of DO11.10 mice, which are transgenic for a T-cell receptor specifically recognizing a peptide of ovalbumin. We showed that the specific T-cell immune response was impaired by high-fat feeding, and that the expression of this defect is different depending on whether T cells are naive or Ag experienced. Indeed, on in vitro ovalbumin stimulation, spleen T cells from naive HFD-fed transgenic mice showed proliferation similar to that of cells from standard diet (SD)-fed mice, but exhibited a strong inflammatory profile as shown by the markedly increased IFN-gamma/IL-4 ratio. Inversely, spleen T cells from ovalbumin-immunized HFD mice were impaired in their Ag-dependent proliferation compared to cells from SD mice. By co-culture experiments, we showed that both T cells and antigen-presenting cells were involved in this impairment. Moreover, in ovalbumin-immunized HFD animals, a trend towards Th2 response was noted, compared to immunized SD mice. This data implies that naive T cells could participate actively in the low-grade systemic inflammation observed in overweight patients. Moreover, the impaired activity of Ag-experienced T cells could have major consequences both in defence against infection and/or in vaccination protocols.

Topics: Animals; Body Weight; Cells, Cultured; Diet Fads; Dose-Response Relationship, Immunologic; Female; Immunization; Metabolism; Mice; Mice, Inbred BALB C; Mice, Transgenic; Obesity; Ovalbumin; Receptors, Antigen, T-Cell; T-Lymphocytes

Some epidemiologic surveys have demonstrated that asthma is more prevalent in obese children and adults. However, the mechanism of association between obesity and asthma has not been fully clarified. This report investigates a murine model for antigen-induced asthma and diet-induced obesity from an immunologic perspective. For the induction of obesity, C57BL/6J mice were fed a high-fat diet supplemented with lard or soybean oil. Mice were then sensitized and challenged with ovalbumin (OVA) to induce allergic lung inflammation. OVA-specific serum immunoglobulin levels were lower in obese mice compared with non-obese control mice. The decline of OVA-specific IgE in the soybean oil group was found to be especially pronounced. However, obese mice with OVA-induced asthma showed a higher sensitivity of antigen-induced T-cell responses, and increased gamma interferon (IFN-gamma) production of splenocytes with phytohemagglutinin (PHA) stimulation. Furthermore, mast cell numbers in the tracheal mucosa were increased in obese mice upon sensitization by OVA. These results suggest that obesity-induced changes in T-cell function may be partly involved in the pathophysiology of asthma in human obesity, rather than Ig E-mediated allergic responses.

Topics: Adipose Tissue; Animals; Asthma; Body Weight; Cell Division; Diet; Dietary Fats; Energy Metabolism; Immunoglobulins; Interferon-gamma; Interleukin-2; Leptin; Mice; Mice, Inbred C57BL; Mitogens; Obesity; Ovalbumin; Respiratory Hypersensitivity; Spleen

Topics: Adrenal Cortex; Adult; Dietary Carbohydrates; Dietary Proteins; Female; Humans; Islets of Langerhans; Male; Maltose; Obesity; Ovalbumin

Fifty-two obese patients were studied initially for two weeks as inpatients on very low calorie diets, containing 0.76-1.34 MJ (180-320 kcal) as 15-40 g egg albumin, 30-40 g oligosaccharides, vitamins and minerals. Patients were seen weekly after discharge from hospital. Forty-one patients were able to continue treatment for more than eight weeks, and 29 for more than 16 weeks. In terms of weight loss, 41 patients lost at least 10 kg body weight, 29 at least 15 kg, and 14 at least 20 kg; 17 patients came within 15 kg of their ideal body weight. With 40 g/day carbohydrate, the quantity of egg albumin required to give nitrogen equilibrium was estimated to be about 25 g/day. All patients were able to resume their normal activities on discharge from hospital and had no major side-effects from treatment. Routine clinical, biochemical and haematological examinations showed no significant changes. In particular, serum proteins, electrolytes, uric acid, cholesterol and blood haemoglobin and haematocrit were unaffected. Ketosis was minimal or absent. It is concluded that the use of very low calorie semi-synthetic diets is a feasible and safe method of weight reduction for obese patients.

Topics: Adolescent; Adult; Aged; Ambulatory Care; Diet, Reducing; Dietary Proteins; Female; Hospitalization; Humans; Male; Middle Aged; Obesity; Ovalbumin; Vitamins