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1.
Obesity (Silver Spring) ; 32(4): 743-755, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38328970

RESUMO

OBJECTIVE: Exposure in utero to maternal diet can program offspring health and susceptibility to disease. Using C57BL6/JArc mice, we investigated how maternal dietary protein to carbohydrate balance influences male and female offspring appetite and metabolic health. METHODS: Dams were placed on either a low-protein (LP) or high-protein (HP) diet. Male and female offspring were placed on a food choice experiment post weaning and were then constrained to either a standard diet or Western diet. Food intake, body weight, and composition were measured, and various metabolic tests were performed at different timepoints. RESULTS: Offspring from mothers fed HP diets selected a higher protein intake and had increased body weight in early life relative to offspring from LP diet-fed dams. As predicted by protein leverage theory, higher protein intake targets led to increased food intake when offspring were placed on no-choice diets, resulting in greater body weight and fat mass. The combination of an HP maternal diet and a Western diet further exacerbated this obesity phenotype and led to long-term consequences for body composition and metabolism. CONCLUSIONS: This work could help explain the association between elevated protein intake in humans during early life and increased risk of obesity in childhood and later life.


Assuntos
Obesidade Infantil , Efeitos Tardios da Exposição Pré-Natal , Humanos , Camundongos , Animais , Masculino , Feminino , Fenômenos Fisiológicos da Nutrição Materna , Peso Corporal , Ingestão de Alimentos , Nutrientes , Dieta Ocidental/efeitos adversos
2.
Cell Rep ; 42(12): 113536, 2023 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-38060447

RESUMO

Fibroblast growth factor 21 (FGF21), an endocrine signal robustly increased by protein restriction independently of an animal's energy status, exerts profound effects on feeding behavior and metabolism. Here, we demonstrate that considering the nutritional contexts within which FGF21 is elevated can help reconcile current controversies over its roles in mediating macronutrient preference, food intake, and energy expenditure. We show that FGF21 is primarily a driver of increased protein intake in mice and that the effect of FGF21 on sweet preference depends on the carbohydrate balance of the animal. Under no-choice feeding, FGF21 infusion either increased or decreased energy expenditure depending on whether the animal was fed a high- or low-energy diet, respectively. We show that while the role of FGF21 in mediating feeding behavior is complex, its role in promoting protein appetite is robust and that the effects on sweet preference and energy expenditure are macronutrient-state-dependent effects of FGF21.


Assuntos
Apetite , Fatores de Crescimento de Fibroblastos , Camundongos , Animais , Fatores de Crescimento de Fibroblastos/metabolismo , Comportamento Alimentar , Metabolismo Energético , Fígado/metabolismo
3.
Cell Rep ; 41(7): 111638, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36384123

RESUMO

Modulation of individual macronutrients or caloric density is known to regulate host resistance to infection in mice. However, the impact of diet composition, independent of macronutrient and energy content, on infection susceptibility is unclear. We show that two laboratory rodent diets, widely used as standard animal feeds and experimental controls, display distinct abilities in supporting mice during influenza infection. Mice placed on the highly processed AIN93G showed increased mortality to infection compared with those on a grain-based chow diet, suggesting a detrimental role for highly processed food in host defense. We further demonstrate that the heightened susceptibility of AIN93G-fed mice was associated with the failure in homeostasis restoration mediated by the cytokine interferon (IFN)-γ. Our findings show that diet composition calibrates host survival threshold by regulating adaptive homeostasis and highlights a pivotal role for extrinsic signals in host phenotype and outcome of host-pathogen interaction.


Assuntos
Influenza Humana , Camundongos , Animais , Humanos , Nutrientes , Dieta
4.
Front Nutr ; 9: 917880, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35942169

RESUMO

Objectives: In utero glycemia is an important determinant of fetal growth. Women with gestational diabetes are more likely to deliver large-for-gestational age babies that are at increased risk for obesity. The maternal nutritional state modulates the development of offspring biological systems during the critical periods of gestation and lactation. Carbohydrate typically contributes most of the dietary energy, however, there are very few mechanistic studies investigating the effects of maternal dietary carbohydrate quality on fetal and offspring outcomes. Therefore, we sought to investigate the direct effects of maternal carbohydrate quality on sex-specific offspring metabolic programming. Methods: Female C57BL/6 mice were fed one of five isocaloric diets: four high-sugar diets based on glucose, sucrose, isomaltulose or fructose (all containing 60% energy as carbohydrate), or a standard, minimally processed, chow diet, and were mated with chow-fed males. Half of the dams were sacrificed for fetus dissection and placental collection, with the remaining giving live birth. All dams were metabolically profiled before and during pregnancy, and pups were similarly profiled at 12 weeks of age. Results: Overall, glucose-fed dams were heavier and fatter than chow or isomaltulose-fed dams. Female fetuses from glucose and isomaltulose-fed mothers weighed less and had smaller livers, than those from chow-fed mothers, with isomaltulose-fed female fetuses also having decreased placental mass. In contrast, male fetuses responded differently to the maternal diets, with heart mass being significantly increased when their mothers were fed fructose-containing diets, that is, sucrose, isomaltulose and fructose. High-sugar fed female offspring weighed the same, but were significantly fatter, than chow-fed offspring at 12 weeks of age, while glucose and isomaltulose-fed male pups displayed a similar phenotype to their mothers'. Conclusion: While both glucose and isomaltulose diets constrained fetal growth in females, only placentas from isomaltulose-fed dams were significantly smaller than those from chow-fed mothers, suggesting the mechanisms through which fetal growth is reduced may be different. Female fetuses of isomaltulose-fed mothers were also lighter than sucrose-fed fetuses suggesting the glycemic index, or rate of glucose digestion and absorption, may be an important factor in determining nutrient availability to the growing fetus.

5.
Nutr Rev ; 80(8): 1856-1895, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35211745

RESUMO

CONTEXT: Most methods for assessing dietary intake have considerable measurement error. Dietary biomarkers are objective tools for dietary assessment. Dietary biomarkers of dietary patterns have not been well described, despite modern dietary guidelines endorsing dietary patterns. OBJECTIVE: This systematic review sought to describe the dietary biomarkers commonly used to assess dietary patterns, and the novel biomarkers of dietary patterns identified by exploratory studies. DATA SOURCES: MEDLINE, Embase, Cochrane Central, PreMEDLINE, and CINAHL databases were searched. DATA EXTRACTION: Data extraction and bias assessment were undertaken in duplicate. DATA ANALYSIS: A qualitative approach was applied, without statistical analysis. CONCLUSION: In controlled settings, dietary biomarkers of single nutrients or of individual foods or food groups are commonly used to assess compliance with dietary patterns. However, currently, there are no dietary biomarkers or biomarker profiles that are able to identify the specific dietary pattern that has been consumed by an individual. Future work should seek to validate novel dietary biomarkers and biomarker profiles that are indicative of specific dietary patterns and their characteristics. A dietary biomarker panel consisting of multiple biomarkers is almost certainly necessary to capture the complexity of dietary patterns. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42019129839.


Assuntos
Dieta , Alimentos , Biomarcadores , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
6.
Nutrients ; 15(1)2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36615733

RESUMO

Quantitative rankings of multiple dietary patterns for their effects on non-communicable disease (NCD) biomarkers is lacking and would inform primary prevention strategies. Accordingly, a network meta-analysis (NMA) was conducted to compare and rank the effects of different dietary patterns on NCD biomarkers, and associations of dietary patterns' underlying macronutrient composition with NCD biomarkers were determined by a nutritional geometry approach. Randomised controlled trials (RCTs) were eligible for inclusion if they enrolled healthy participants, employed food-based dietary pattern interventions without energy restriction, and reported NCD biomarker outcomes. NCD biomarkers were included as an outcome if ≥10 trials were available. A systematic search of five electronic databases identified 4008 records. Sixty-eight articles from 59 RCTs reporting lipids, glycemic, and inflammatory biomarkers were included for quantitative syntheses. Risk-of-bias was predominantly categorized as low or having some concerns, and confidence-of-evidence low. Relative to western habitual diet, the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), dietary guidelines-based, plant-based, and low-fat diets reduced low-density lipoprotein cholesterol (mean difference range: −0.29 to −0.17 mmol/L), total cholesterol (−0.36 to −0.24 mmol/L), and apolipoprotein B (−0.11 to −0.07 g/L) (all p < 0.05); the Paleo, plant-based and dietary guidelines-based diets reduced homeostasis model assessment of insulin resistance (−0.95 to −0.35, all p < 0.05). No dietary pattern ranked consistently highest. The Paleo diet received the highest all-outcomes-combined average Surface Under the Cumulative Ranking Curve value (67%), followed by DASH (62%) and Mediterranean diets (57%), whereas western habitual diet was lowest (36%). Our findings were independent of macronutrient composition, highlighting the significance of dietary pattern-level analysis.


Assuntos
Dieta Mediterrânea , Doenças não Transmissíveis , Humanos , Doenças não Transmissíveis/prevenção & controle , Metanálise em Rede , LDL-Colesterol , Dieta com Restrição de Gorduras
7.
Sci Rep ; 11(1): 14993, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294791

RESUMO

The treatment of periodontitis has numerous positive effects on established chronic health conditions, including cardiovascular disease and diabetes. However, ethical considerations do limit the establishment of human trials to investigate whether periodontitis promotes the early stages of chronic conditions. Therefore, the aim of this study was to investigate whether periodontitis induces endothelial dysfunction in hyperlipidemic apolipoprotein E gene-deficient (ApoE-/-) mice. Forty-five 8-week-old ApoE-/- mice were challenged by oral lavage with Porphyromonas gingivalis and Streptococcus gordonii for 4 weeks. A subgroup of animals (n = 15-17/group) was placed in a metabolic chamber immediately before euthanasia at 4 weeks to measure VO2/CO2 concentrations and voluntary locomotion. In infected and control animals alveolar bone levels were measured by x-ray imaging and endothelial function was determined by measuring endothelial-dependent vasorelaxation of aortic rings. The mRNA expression levels of serum amyloid A and tumor necrosis factor were determined in liver tissues by qRT PCR and protein concentrations in serum by ELISA. Caecal contents were analysed by sequencing to determine changes to the gut microbiota to investigate linkages between microbiome and systemic changes. The results showed that oral lavage of P. gingivalis and S. gordonii for 4 weeks, initiated periodontitis in ApoE-/- mice, similar to the human situation. The oral inflammation was accompanied by a significant increase in mRNA expression of pro-inflammatory mediators serum amyloid A1 and tumor necrosis factor in the liver. Mice with periodontitis also exhibited impaired endothelial-dependent vasorelaxation responses to acetylcholine. This systemic response was connected to increased energy expenditure, locomotion and respiratory quotient. No differences were detected in caecal microbiota between the infected and control animals. Overall, this is the first report that provide evidence that periodontitis induces endothelial dysfunction in mice. Other systemic responses observed in response to the local reaction need further investigation. The study suggests that early prevention of periodontitis may help limit the early stages of endothelial dysfunction that is linked to atherogenesis in humans.


Assuntos
Apolipoproteínas E/genética , Infecções por Bacteroidaceae/diagnóstico por imagem , Hiperlipidemias/genética , Periodontite/microbiologia , Placa Aterosclerótica/diagnóstico por imagem , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Modelos Animais de Doenças , Metabolismo Energético , Microbioma Gastrointestinal , Técnicas de Inativação de Genes , Hiperlipidemias/microbiologia , Masculino , Camundongos , Periodontite/diagnóstico por imagem , Periodontite/genética , Filogenia , Placa Aterosclerótica/microbiologia , Porphyromonas gingivalis/patogenicidade , Análise de Sequência de RNA , Proteína Amiloide A Sérica/genética , Proteína Amiloide A Sérica/metabolismo , Streptococcus gordonii/patogenicidade , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Raios X
8.
Nat Metab ; 3(6): 810-828, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34099926

RESUMO

Reduced protein intake, through dilution with carbohydrate, extends lifespan and improves mid-life metabolic health in animal models. However, with transition to industrialised food systems, reduced dietary protein is associated with poor health outcomes in humans. Here we systematically interrogate the impact of carbohydrate quality in diets with varying carbohydrate and protein content. Studying 700 male mice on 33 isocaloric diets, we find that the type of carbohydrate and its digestibility profoundly shape the behavioural and physiological responses to protein dilution, modulate nutrient processing in the liver and alter the gut microbiota. Low (10%)-protein, high (70%)-carbohydrate diets promote the healthiest metabolic outcomes when carbohydrate comprises resistant starch (RS), yet the worst outcomes were with a 50:50 mixture of monosaccharides fructose and glucose. Our findings could explain the disparity between healthy, high-carbohydrate diets and the obesogenic impact of protein dilution by glucose-fructose mixtures associated with highly processed diets.


Assuntos
Dieta , Carboidratos da Dieta/metabolismo , Proteínas Alimentares/metabolismo , Metabolismo Energético , Homeostase , Animais , Glucose/metabolismo , Nível de Saúde , Masculino , Camundongos , Obesidade/etiologia , Obesidade/metabolismo , Amido/metabolismo
9.
Nat Commun ; 11(1): 2922, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32523103

RESUMO

The conversion of white adipocytes to thermogenic beige adipocytes represents a potential mechanism to treat obesity and related metabolic disorders. However, the mechanisms involved in converting white to beige adipose tissue remain incompletely understood. Here we show profound beiging in a genetic mouse model lacking the transcriptional repressor Krüppel-like factor 3 (KLF3). Bone marrow transplants from these animals confer the beige phenotype on wild type recipients. Analysis of the cellular and molecular changes reveal an accumulation of eosinophils in adipose tissue. We examine the transcriptomic profile of adipose-resident eosinophils and posit that KLF3 regulates adipose tissue function via transcriptional control of secreted molecules linked to beiging. Furthermore, we provide evidence that eosinophils may directly act on adipocytes to drive beiging and highlight the critical role of these little-understood immune cells in thermogenesis.


Assuntos
Tecido Adiposo/metabolismo , Eosinófilos/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Transdução de Sinais/fisiologia , Adiposidade/genética , Adiposidade/fisiologia , Animais , Células COS , Chlorocebus aethiops , Imunoprecipitação da Cromatina , Citometria de Fluxo , Fatores de Transcrição Kruppel-Like/genética , Masculino , Camundongos , Obesidade/metabolismo , Transdução de Sinais/genética , Software
10.
Nat Commun ; 10(1): 5291, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757939

RESUMO

Histone deacetylase 3 (Hdac3) regulates the expression of lipid metabolism genes in multiple tissues, however its role in regulating lipid metabolism in the intestinal epithelium is unknown. Here we demonstrate that intestine-specific deletion of Hdac3 (Hdac3IKO) protects mice from diet induced obesity. Intestinal epithelial cells (IECs) from Hdac3IKO mice display co-ordinate induction of genes and proteins involved in mitochondrial and peroxisomal ß-oxidation, have an increased rate of fatty acid oxidation, and undergo marked remodelling of their lipidome, particularly a reduction in long chain triglycerides. Many HDAC3-regulated fatty oxidation genes are transcriptional targets of the PPAR family of nuclear receptors, Hdac3 deletion enhances their induction by PPAR-agonists, and pharmacological HDAC3 inhibition induces their expression in enterocytes. These findings establish a central role for HDAC3 in co-ordinating PPAR-regulated lipid oxidation in the intestinal epithelium, and identify intestinal HDAC3 as a potential therapeutic target for preventing obesity and related diseases.


Assuntos
Enterócitos/metabolismo , Histona Desacetilases/genética , Metabolismo dos Lipídeos/genética , Obesidade/genética , Animais , Calorimetria , Dieta Hiperlipídica , Ácidos Graxos/metabolismo , Deleção de Genes , Regulação da Expressão Gênica , Mucosa Intestinal/metabolismo , Peroxidação de Lipídeos/genética , Lipidômica , Camundongos , Mitocôndrias/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/agonistas , Receptores Ativados por Proliferador de Peroxissomo/genética , Triglicerídeos/metabolismo
11.
Nat Metab ; 1(5): 532-545, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31656947

RESUMO

Elevated branched chain amino acids (BCAAs) are associated with obesity and insulin resistance. How long-term dietary BCAAs impact late-life health and lifespan is unknown. Here, we show that when dietary BCAAs are varied against a fixed, isocaloric macronutrient background, long-term exposure to high BCAA diets leads to hyperphagia, obesity and reduced lifespan. These effects are not due to elevated BCAA per se or hepatic mTOR activation, but rather due to a shift in the relative quantity of dietary BCAAs and other AAs, notably tryptophan and threonine. Increasing the ratio of BCAAs to these AAs resulted in hyperphagia and is associated with central serotonin depletion. Preventing hyperphagia by calorie restriction or pair-feeding averts the health costs of a high BCAA diet. Our data highlight a role for amino acid quality in energy balance and show that health costs of chronic high BCAA intakes need not be due to intrinsic toxicity but, rather, a consequence of hyperphagia driven by AA imbalance.


Assuntos
Aminoácidos de Cadeia Ramificada/metabolismo , Aminoácidos/metabolismo , Regulação do Apetite , Expectativa de Vida , Animais , Feminino , Regulação da Expressão Gênica , Hiperfagia/metabolismo , Hipotálamo/metabolismo , Resistência à Insulina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Serotonina/metabolismo , Triptofano/metabolismo
12.
Proc Biol Sci ; 286(1902): 20190867, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-31088275

RESUMO

Many animals capable of deploying chemical defences are reluctant to use them, suggesting that synthesis of toxins imposes a substantial cost. Typically, such costs have been quantified by measuring the elevation in metabolic rate induced by toxin depletion (i.e. during replenishment of toxin stores). More generally, we might expect that toxin depletion will induce shifts in a broad suite of fitness-relevant traits. In cane toads ( Rhinella marina), toxic compounds that protect against predators and pathogens are stored in large parotoid (shoulder) glands. We used correlational and experimental approaches in field and laboratory settings to investigate impacts of toxin depletion on growth rate and behaviour in cane toads. In free-ranging toads, larger toxin stores were associated with smaller gonads and livers, suggesting energetic trade-offs between toxin production and both reproduction and energy metabolism. Experimental removal of toxin (by manually squeezing parotoid glands) reduced rates of growth in body mass in both captive and free-ranging toads. Radio tracking demonstrated that de-toxined toads dispersed more slowly than did control toads. Given that toxin stores in cane toads take several months to fully replenish, deploying toxin to repel a predator may impose a substantial cost, explaining why toads use toxin only as a final line of defence.


Assuntos
Bufo marinus/fisiologia , Metabolismo Energético , Reprodução , Toxinas Biológicas/fisiologia , Animais , Bufo marinus/crescimento & desenvolvimento , Glândulas Exócrinas/química
13.
J Endocrinol ; 241(3): 189-199, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30939450

RESUMO

Poor nutrition plays a fundamental role in the development of insulin resistance, an underlying characteristic of type 2 diabetes. We have previously shown that high-fat diet-induced insulin resistance in rats can be ameliorated by a single glucose meal, but the mechanisms for this observation remain unresolved. To determine if this phenomenon is mediated by gut or hepatoportal factors, male Wistar rats were fed a high-fat diet for 3 weeks before receiving one of five interventions: high-fat meal, glucose gavage, high-glucose meal, systemic glucose infusion or portal glucose infusion. Insulin sensitivity was assessed the following day in conscious animals by a hyperinsulinaemic-euglycaemic clamp. An oral glucose load consistently improved insulin sensitivity in high-fat-fed rats, establishing the reproducibility of this model. A systemic infusion of a glucose load did not affect insulin sensitivity, indicating that the physiological response to oral glucose was not due solely to increased glucose turnover or withdrawal of dietary lipid. A portal infusion of glucose produced the largest improvement in insulin sensitivity, implicating a role for the hepatoportal region rather than the gastrointestinal tract in mediating the effect of glucose to improve lipid-induced insulin resistance. These results further deepen our understanding of the mechanism of glucose-mediated regulation of insulin sensitivity and provide new insight into the role of nutrition in whole body metabolism.


Assuntos
Tecido Adiposo/metabolismo , Glicemia/análise , Dieta Hiperlipídica , Insulina/metabolismo , Fígado/metabolismo , Veia Porta/metabolismo , Ração Animal , Animais , Diabetes Mellitus Tipo 2/metabolismo , Gorduras na Dieta , Modelos Animais de Doenças , Glucose/administração & dosagem , Técnica Clamp de Glucose , Resistência à Insulina , Lipídeos/sangue , Masculino , Ratos , Ratos Wistar
14.
Nutrients ; 10(10)2018 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-30241328

RESUMO

Maternal diet and gestational hyperglycaemia have implications for offspring health. Leptin (LEP) and fat mass and obesity-associated (FTO) alleles are known to influence body fat mass in humans, potentially via effects on appetite. We hypothesized that expression of Fto, Lep, and other appetite-related genes (Argp, Npy, Pomc, Cart, Lepr) in the offspring of female mice are influenced by the glycaemic index (GI) of carbohydrates in the maternal diet. C57BL/6 mice were randomly assigned to low or high GI diets and mated with chow-fed males at eight weeks of age. Male pups were weaned at four weeks and randomly divided into two groups, one group following their mother's diet (LL and HH), and one following the standard chow diet (LC and HC) to 20 weeks. Fto expression was 3.8-fold higher in the placenta of mothers fed the high GI diet (p = 0.0001) and 2.5-fold higher in the hypothalamus of 20-week old offspring fed the high GI (HH vs. LL, p < 0.0001). By contrast, leptin gene (Lep) expression in visceral adipose tissue was 4.4-fold higher in four-week old offspring of low GI mothers (LC vs. HC, p < 0.0001) and 3.3-fold higher in visceral adipose tissue of 20-week old animals (LL vs. HH, p < 0.0001). Plasma ghrelin and leptin levels, and hypothalamic appetite genes were also differentially regulated by maternal and offspring diet. These findings provide the first evidence in an animal model that maternal high GI dietary carbohydrates that are digested and absorbed faster may contribute to programming of appetite in offspring.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Carboidratos da Dieta/administração & dosagem , Índice Glicêmico , Leptina/metabolismo , Fenômenos Fisiológicos da Nutrição Materna , Estado Nutricional , Efeitos Tardios da Exposição Pré-Natal , Proteína Relacionada com Agouti/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Animais , Carboidratos da Dieta/metabolismo , Feminino , Regulação da Expressão Gênica , Hipotálamo/metabolismo , Gordura Intra-Abdominal/metabolismo , Leptina/genética , Masculino , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/metabolismo , Neuropeptídeo Y/metabolismo , Placenta/metabolismo , Gravidez , Pró-Opiomelanocortina/metabolismo , Receptores para Leptina/metabolismo
15.
Nutrients ; 10(7)2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29966395

RESUMO

The glycaemic index (GI) is a useful tool to compare the glycaemic responses of foods. Numerous studies report the favorable effects of low GI diets on long term metabolic health compared with high GI diets. However, it has not been possible to link these effects to the GI itself because of other components such as macronutrients and dietary fibre, which are known to affect GI. This study aimed to create and evaluate isocaloric diets differing in GI independent of macronutrient and fibre content. The GIs of eight diets differing in carbohydrate source were evaluated in mice; cooked cornstarch (CC), raw cornstarch (RC), chow, maltodextrin, glucose, sucrose, isomaltulose, and fructose. A glucose control was also tested. The GIs of all eight diets were different from the GI of the glucose control (GI: 100; p < 0.0001). The GIs of the glucose (mean ± SEM: 52 ± 3), maltodextrin (52 ± 6), CC (50 ± 4), RC (50 ± 6), and chow (44 ± 4) diets were similar, while the GIs of the sucrose (31 ± 4), isomaltulose (24 ± 5), and fructose (18 ± 2) diets were lower than all other diets (p < 0.05). This is the first trial to report GI testing in vivo in mice, resulting in three main findings: chow is relatively high GI, the glucose availability of raw and cooked cornstarch is similar, and the GI of different sugar diets occur in the same rank order as in humans.


Assuntos
Ração Animal , Glicemia/metabolismo , Açúcares da Dieta/metabolismo , Índice Glicêmico , Animais , Biomarcadores/sangue , Fibras na Dieta/administração & dosagem , Fibras na Dieta/metabolismo , Sacarose Alimentar/metabolismo , Açúcares da Dieta/administração & dosagem , Feminino , Frutose/metabolismo , Isomaltose/metabolismo , Camundongos Endogâmicos C57BL , Valor Nutritivo , Polissacarídeos/metabolismo , Amido/metabolismo , Fatores de Tempo
16.
Nutrients ; 9(7)2017 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-28640233

RESUMO

Low glycaemic index (LGI) diets are often reported to benefit metabolic health, but the mechanism(s) responsible are not clear. This review aimed to systematically identify studies investigating metabolic effects of high glycaemic index (HGI) versus LGI diets in mice and rats. A meta-analysis was conducted to calculate an overall effect size, Hedge's standardised mean differences (hereafter d), for each trait, with moderator variables considered in subsequent meta-regressions. Across 30 articles, a HGI diet increased five of the seven traits examined: body weight (d = 0.55; 95% confidence interval: 0.31, 0.79), fat mass (d = 1.08; 0.67, 1.49), fasting circulating insulin levels (d = 0.40; 0.09, 0.71), and glucose (d = 0.80; 0.35, 1.25) and insulin (d = 1.14; 0.50, 1.77) area under the curve during a glucose tolerance test. However, there was substantial heterogeneity among the effects for all traits and the small number of studies enabled only limited investigation of possible confounding factors. HGI diets favour body weight gain, increased adiposity and detrimentally affect parameters of glucose homeostasis in mice and rats, but these effects may not be a direct result of GI per se; rather they may be due to variation in other dietary constituents, such as dietary fibre, a factor which is known to reduce the GI of food and promote health via GI-independent mechanisms.


Assuntos
Dieta , Metabolismo Energético , Índice Glicêmico , Animais , Glucose/metabolismo , Camundongos , Ratos
17.
Adipocyte ; 6(2): 112-123, 2017 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-28453382

RESUMO

Understanding adipose tissue heterogeneity is hindered by the paucity of methods to analyze mature adipocytes at the single cell level. Here, we report a system for analyzing live adipocytes from different adipose depots in the adult mouse. Single cell suspensions of buoyant adipocytes were separated from the stromal vascular fraction and analyzed by flow cytometry. Compared to other lipophilic dyes, Nile Red uptake effectively distinguished adipocyte populations. Nile Red fluorescence increased with adipocyte size and granularity and could be combined with MitoTracker® Deep Red or fluorescent antibody labeling to further dissect adipose populations. Epicardial adipocytes exhibited the least mitochondrial membrane depolarization and highest fatty-acid translocase CD36 surface expression. In contrast, brown adipocytes showed low surface CD36 expression. Pregnancy resulted in reduced mitochondrial membrane depolarisation and increased CD36 surface expression in brown and epicardial adipocyte populations respectively. Our protocol revealed unreported heterogeneity between adipose depots and highlights the utility of flow cytometry for screening adipocytes at the single cell level.


Assuntos
Adipócitos/citologia , Análise de Célula Única/métodos , Adipócitos/fisiologia , Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Tecido Adiposo/citologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Adiposidade , Animais , Antígenos CD36 , Diferenciação Celular , Citometria de Fluxo/métodos , Corantes Fluorescentes , Camundongos , Obesidade/metabolismo
18.
Mol Metab ; 6(1): 48-60, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28123937

RESUMO

OBJECTIVE: Dietary supplementation with fermentable carbohydrate protects against body weight gain. Fermentation by the resident gut microbiota produces short-chain fatty acids, which act at free fatty acid receptor 2 (FFAR2). Our aim was to test the hypothesis that FFAR2 is important in regulating the beneficial effects of fermentable carbohydrate on body weight and to understand the role of gut hormones PYY and GLP-1. METHODS: Wild-type or Ffar2-/- mice were fed an inulin supplemented or control diet. Mice were metabolically characterized and gut hormone concentrations, enteroendocrine cell density measurements were carried out. Intestinal organoids and colonic cultures were utilized to substantiate the in vivo findings. RESULTS: We provide new mechanistic insight into how fermentable carbohydrate regulates metabolism. Using mice that lack FFAR2, we demonstrate that the fermentable carbohydrate inulin acts via this receptor to drive an 87% increase in the density of cells that produce the appetite-suppressing hormone peptide YY (PYY), reduce food intake, and prevent diet-induced obesity. CONCLUSION: Our results demonstrate that FFAR2 is predominantly involved in regulating the effects of fermentable carbohydrate on metabolism and does so, in part, by enhancing PYY cell density and release. This highlights the potential for targeting enteroendocrine cell differentiation to treat obesity.


Assuntos
Carboidratos da Dieta/metabolismo , Peptídeo YY/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Peso Corporal , Colo/citologia , Suplementos Nutricionais , Ingestão de Alimentos , Ácidos Graxos Voláteis/metabolismo , Fermentação , Alimentos Fermentados , Hormônios Gastrointestinais/metabolismo , Microbioma Gastrointestinal/fisiologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Inulina/metabolismo , Masculino , Camundongos , Camundongos Knockout , Obesidade/metabolismo , Receptores de Superfície Celular/fisiologia , Aumento de Peso
19.
J Biol Chem ; 291(31): 16048-58, 2016 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-27226561

RESUMO

The Lgals3 gene encodes a multifunctional ß-galactoside-binding protein, galectin-3. Galectin-3 has been implicated in a broad range of biological processes from chemotaxis and inflammation to fibrosis and apoptosis. The role of galectin-3 as a modulator of inflammation has been studied intensively, and recent evidence suggests that it may serve as a protective factor in obesity and other metabolic disorders. Despite considerable interest in galectin-3, little is known about its physiological regulation at the transcriptional level. Here, using knockout mice, chromatin immunoprecipitations, and cellular and molecular analyses, we show that the zinc finger transcription factor Krüppel-like factor 3 (KLF3) directly represses galectin-3 transcription. We find that galectin-3 is broadly up-regulated in KLF3-deficient mouse tissues, that KLF3 occupies regulatory regions of the Lgals3 gene, and that KLF3 directly binds its cognate elements (CACCC boxes) in the galectin-3 promoter and represses its activation in cellular assays. We also provide mechanistic insights into the regulation of Lgals3, demonstrating that C-terminal binding protein (CtBP) is required to drive optimal KLF3-mediated silencing. These findings help to enhance our understanding of how expression of the inflammatory modulator galectin-3 is controlled, opening up avenues for potential therapeutic interventions in the future.


Assuntos
Galectina 3/biossíntese , Inativação Gênica , Mediadores da Inflamação/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Repressoras/metabolismo , Elementos de Resposta , Transcrição Gênica , Animais , Galectina 3/genética , Fatores de Transcrição Kruppel-Like/genética , Camundongos , Camundongos Knockout , Proteínas Repressoras/genética
20.
Obesity (Silver Spring) ; 23(9): 1845-55, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26250514

RESUMO

OBJECTIVE: Adipose inflammation and dysfunction underlie metabolic obesity. Exercise improves glycemic control and metabolic indices, but effects on adipose function and inflammation are less clear. Accordingly, it was hypothesized that exercise improves adipose morphometry to reduce adipose inflammation in hyperphagic obese mice. METHODS: Alms1 mutant foz/foz mice housed in pairs were fed an atherogenic or chow diet; half the cages were fitted with a computer-monitored wheel for voluntary exercise. Insulin-induced AKT-phosphorylation, adipocyte size distribution, and inflammatory recruitment were studied in visceral versus subcutaneous depots, and severity of fatty liver disease was determined. RESULTS: Exercise prevented obesity and diabetes development in chow-fed foz/foz mice and delayed their onset in atherogenic-fed counterparts. Insulin-stimulated phospho-AKT levels in muscle were improved with exercise, but not in adipose or liver. Exercise suppressed adipose inflammatory recruitment, particularly in visceral adipose, associated with an increased number of small adipocyte subpopulations, and enhanced expression of beige adipocyte factor PRDM16 in subcutaneous fat. In atherogenic-fed foz/foz mice liver, exercise suppressed development of nonalcoholic steatohepatitis and related liver fibrosis. CONCLUSIONS: Exercise confers metabo-protective effects in atherogenic-fed hyperphagic mice by preventing early onset of obesity and diabetes in association with enhanced muscle insulin sensitivity, improved adipose morphometry, and suppressed adipose and liver inflammation.


Assuntos
Diabetes Mellitus Experimental/complicações , Inflamação/complicações , Hepatopatia Gordurosa não Alcoólica/terapia , Obesidade/complicações , Condicionamento Físico Animal/métodos , Animais , Camundongos , Camundongos Obesos , Hepatopatia Gordurosa não Alcoólica/complicações
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