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1.
Sci Data ; 9(1): 265, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35654905

RESUMO

Trait databases have become important resources for large-scale comparative studies in ecology and evolution. Here we introduce the AnimalTraits database, a curated database of body mass, metabolic rate and brain size, in standardised units, for terrestrial animals. The database has broad taxonomic breadth, including tetrapods, arthropods, molluscs and annelids from almost 2000 species and 1000 genera. All data recorded in the database are sourced from their original empirical publication, and the original metrics and measurements are included with each record. This allows for subsequent data transformations as required. We have included rich metadata to allow users to filter the dataset. The additional R scripts we provide will assist researchers with aggregating standardised observations into species-level trait values. Our goals are to provide this resource without restrictions, to keep the AnimalTraits database current, and to grow the number of relevant traits in the future.


Assuntos
Metabolismo Basal , Peso Corporal , Encéfalo , Bases de Dados Factuais , Animais , Ecologia , Tamanho do Órgão , Fenótipo
2.
Elife ; 112022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35674717

RESUMO

On the social scale, the blind mole rat (BMR; Spalax ehrenbergi) is an extreme. It is exceedingly solitary, territorial, and aggressive. BMRs reside underground, in self-excavated tunnels that they rarely leave. They possess specialized sensory systems for social communication and navigation, which allow them to cope with the harsh environmental conditions underground. This review aims to present the blind mole rat as an ideal, novel neuroethological model for studying aggressive and solitary behaviors. We discuss the BMR's unique behavioral phenotype, particularly in the context of 'anti-social' behaviors, and review the available literature regarding its specialized sensory adaptations to the social and physical habitat. To date, the neurobiology of the blind mole rat remains mostly unknown and holds a promising avenue for scientific discovery. Unraveling the neural basis of the BMR's behavior, in comparison to that of social rodents, can shed important light on the underlying mechanisms of psychiatric disorders in humans, in which similar behaviors are displayed.


Assuntos
Metabolismo Basal , Ratos-Toupeira , Animais , Humanos
3.
Clin Nutr ; 41(7): 1591-1599, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35671611

RESUMO

BACKGROUND & AIMS: The new indirect calorimeter developed in the framework of the ICALIC project was first evaluated in ventilation mode. This second phase aimed to compare its ease of use and precision with another commonly used device in spontaneously breathing adult patients using a canopy hood or a face mask. METHODS: The time required to measure resting energy expenditure (REE) with Q-NRG® in canopy and face mask mode was compared with Quark RMR® in canopy mode by sequential measurements in 45 and 40 spontaneously breathing adult patients, respectively. Their precision was assessed at different time intervals, using coefficients of variation (CV%) and repeated measures one-way ANOVA. Agreement between the two devices was evaluated by correlation coefficients, Bland-Altman plots, and paired t-test. Patients' characteristics potentially affecting the measurement were assessed using linear regression analysis. RESULTS: REE measurement with Q-NRG® was faster than Quark RMR® (19.7 ± 2.9 min vs 24.5 ± 4.3 min, P < 0.001). In canopy mode, Q-NRG® gave values similar to Quark RMR®, with 73% of patients achieving a steady state (CV% <10%) within the 5-15 min interval. In face mask mode, Q-NRG® was less stable than Quark RMR® in canopy mode, and steady state was achieved in only 40% of the patients within the 5-15 min interval. Correlation between the two devices was stronger when Q-NRG® was used in canopy than in face mask mode, with Pearson coefficients of 0.96 and 0.86, respectively. Compared to Quark RMR® in canopy mode, systematic bias±1.96∗SD with Q-NRG® was -14 ± 236 kcal/day in canopy and 73 ± 484 kcal/day in face mask mode. Q-NRG® in face mask mode overestimated REE by 150 ± 51 kcal/day in men compared to Quark RMR® in canopy mode. CONCLUSIONS: Q-NRG® in canopy mode made it possible to save at least 5 min compared to Quark RMR® while maintaining the same measurement precision. However, its use in face mask mode could lead to REE overestimation in men and, therefore, should not be recommended in the clinical setting. TRIAL REGISTRATION: ClinicalTrials.gov no. NCT03947294.


Assuntos
Metabolismo Energético , Máscaras , Adulto , Análise de Variância , Metabolismo Basal , Calorimetria Indireta , Humanos , Masculino , Reprodutibilidade dos Testes , Descanso
4.
Proc Natl Acad Sci U S A ; 119(26): e2116645119, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35727970

RESUMO

Physiological performance declines precipitously at high body temperature (Tb), but little attention has been paid to adaptive variation in upper Tb limits among endotherms. We hypothesized that avian maximum tolerable Tb (Tbmax) has evolved in response to climate, with higher Tbmax in species exposed to high environmental heat loads or humidity-related constraints on evaporative heat dissipation. To test this hypothesis, we compared Tbmax and related variables among 53 bird species at multiple sites in South Africa with differing maximum air temperature (Tair) and humidity using a phylogenetically informed comparative framework. Birds in humid, lowland habitats had comparatively high Tbmax (mean ± SD = 45.60 ± 0.58 °C) and low normothermic Tb (Tbnorm), with a significantly greater capacity for hyperthermia (Tbmax - Tbnorm gradient = 5.84 ± 0.77 °C) compared with birds occupying cool montane (4.97 ± 0.99 °C) or hot arid (4.11 ± 0.84 °C) climates. Unexpectedly, Tbmax was significantly lower among desert birds (44.65 ± 0.60 °C), a surprising result in light of the functional importance of hyperthermia for water conservation. Our data reveal a macrophysiological pattern and support recent arguments that endotherms have evolved thermal generalization versus specialization analogous to the continuum among ectothermic animals. Specifically, a combination of modest hyperthermia tolerance and efficient evaporative cooling in desert birds is indicative of thermal specialization, whereas greater hyperthermia tolerance and less efficient evaporative cooling among species in humid lowland habitats suggest thermal generalization.


Assuntos
Aves , Regulação da Temperatura Corporal , Temperatura Alta , Perda Insensível de Água , Animais , Metabolismo Basal/fisiologia , Aves/fisiologia , Regulação da Temperatura Corporal/fisiologia , Umidade , África do Sul , Perda Insensível de Água/fisiologia
5.
J Exp Biol ; 225(12)2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35762381

RESUMO

We investigated the role of mitochondrial function in the avian thermoregulatory response to a cold environment. Using black-capped chickadees (Poecile atricapillus) acclimated to cold (-10°C) and thermoneutral (27°C) temperatures, we expected to observe an upregulation of pectoralis muscle and liver respiratory capacity that would be visible in mitochondrial adjustments in cold-acclimated birds. We also predicted that these adjustments would correlate with thermogenic capacity (Msum) and basal metabolic rate (BMR). Using tissue high-resolution respirometry, mitochondrial performance was measured as respiration rate triggered by proton leak and the activity of complex I (OXPHOSCI) and complex I+II (OXPHOSCI+CII) in the liver and pectoralis muscle. The activity of citrate synthase (CS) and cytochrome c oxidase (CCO) was also used as a marker of mitochondrial density. We found 20% higher total CS activity in the whole pectoralis muscle and 39% higher total CCO activity in the whole liver of cold-acclimated chickadees relative to that of birds kept at thermoneutrality. This indicates that cold acclimation increased overall aerobic capacity of these tissues. Msum correlated positively with mitochondrial proton leak in the muscle of cold-acclimated birds while BMR correlated with OXPHOSCI in the liver with a pattern that differed between treatments. Consequently, this study revealed a divergence in mitochondrial metabolism between thermal acclimation states in birds. Some functions of the mitochondria covary with thermogenic capacity and basal maintenance costs in patterns that are dependent on temperature and body mass.


Assuntos
Metabolismo Basal , Aves Canoras , Aclimatação/fisiologia , Animais , Metabolismo Basal/fisiologia , Temperatura Baixa , Mitocôndrias/metabolismo , Músculos Peitorais/metabolismo , Prótons , Aves Canoras/fisiologia
6.
Asia Pac J Clin Nutr ; 31(2): 215-221, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35766557

RESUMO

BACKGROUND AND OBJECTIVES: Patients with liver failure often have energy metabolism disorders and malnutrition, which lead to poor prognosis, rendering nutritional interventions essential. METHODS AND STUDY DESIGN: Individualized nutritional interventions were offered according to the resting energy expenditure (REE) of patients with liver failure, and the patients were followed up for 180 days. RESULTS: Sixty patients with liver failure were enrolled and grouped by their prognosis and energy intake. Model for end-stage liver disease (MELD) score and body fat mass of the nonsurvival group were significantly higher than those of the survival group (p<0.05), whereas the mean energy intake/REE (MEI/REE) and mean respiratory quotient (RQ) of the nonsurvival group were significantly lower than those of the survival group (p<0.01). Prediction REE (PredREE) was calculated using the Harris-Benedict formula. Most patients in the nonsurvival and survival groups had hypometabolic (REE/PredREE <0.9) and normal metabolic status (0.9

Assuntos
Doença Hepática Terminal , Metabolismo Basal , Calorimetria Indireta , Ingestão de Energia , Metabolismo Energético , Humanos , Prognóstico , Índice de Gravidade de Doença
7.
Biol Lett ; 18(6): 20220036, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35702980

RESUMO

The energy cost of adaptive immune activation in endotherms is typically quantified from changes in resting metabolic rate following exposure to a novel antigen. An implicit assumption of this technique is that all variation in energy costs following antigenic challenge is due solely to adaptive immunity, while ignoring potential changes in the energy demands of ongoing bodily functions. We critically assess this assumption by measuring both basal metabolic rate (BMR) and exercise-induced maximal metabolic rate (MMR) in house sparrows before and after the primary and two subsequent vaccinations with either saline (sham) or two novel antigens (keyhole limpet haemocyanin and sheep red blood cells; KLH and SRBC, respectively). We also examined the effect of inducing male breeding levels of testosterone (T) on immune responses and their metabolic costs in both males and females. Although there was a moderate decrease in KLH antibody formation in T-treated birds, there was no effect of T on BMR, MMR or immunity to SRBC. There was no effect of vaccination on BMR but, surprisingly, all vaccinated birds maintained MMR better than sham-treated birds as the experiment progressed. Our findings caution against emphasizing energy costs or nutrient diversion as being responsible for reported fitness reductions following activation of adaptive immunity.


Assuntos
Pardais , Animais , Metabolismo Basal/fisiologia , Metabolismo Energético/fisiologia , Feminino , Masculino , Ovinos , Pardais/fisiologia
8.
Nutrition ; 99-100: 111652, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35576872

RESUMO

OBJECTIVES: Obesity is a disorder of energy balance with increasing prevalence in Indian children. Objectives were to study 1) resting metabolic rate (RMR), anthropometry, body composition (BC), and their relationships in Indian children and adolescents affected with overweight (OW) or obesity (OB) and in non-overweight (NOW) children and 2) factors influencing RMR, such as age, sex, and BC. METHODS: This cross-sectional, observational, multicentric study included 495 children (260 boys) of age 9-18 y who were assessed from six Indian states for sociodemographic and anthropometric parameters using standard protocols. Body composition was assessed by a body impedance analyzer technique (Tanita-BC-420), and RMR was assessed using indirect calorimetry. Data were analyzed using SPSS (version 26) with appropriate statistical tests. The level of significance was set at P < 0.05. RESULTS: Boys had higher absolute RMR values than did girls (1212±263 kcal/d versus 1066±204 kcal/d; P < 0.001). Weight-adjusted RMR was significantly lower among children classified as OW or OB than among NOW children of both sexes, respectively (P < 0.001). Linear regression analysis revealed fat-free mass, sex, age, and body mass index (BMI) as significant predictors of RMR (P < 0.05). CONCLUSIONS: We found lower weight-adjusted RMR in children classified as OW or OB as compared with NOW children. Our study underlines the importance of low RMR levels among children with a higher BMI, in girls, and with increasing age.


Assuntos
Metabolismo Basal , Composição Corporal , Adolescente , Índice de Massa Corporal , Calorimetria Indireta , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Obesidade/metabolismo , Sobrepeso
9.
Nutrition ; 99-100: 111632, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35588651

RESUMO

OBJECTIVE: Indirect calorimetry is the recommended, most accurate way to measure resting energy expenditure (REE) in critically ill, mechanically ventilated patients. We tested the agreement of two systems: the Mindray metabolic system (the system to be validated) and the GE S/5 metabolic system (the reference system). We also compared the measurements obtained to commonly used predictive equations. METHODS: This was a prospective single-center study, in a general 16-bed intensive care unit, with critically ill, mechanically ventilated patients eligible to undergo indirect calorimetry. REE was measured successively during the same session with two 30-min measurements. The agreement and bias between oxygen consumption, carbon dioxide production, REE, and respiratory quotient obtained by Mindray and GE systems were compared using Bland-Altman plots. A priori we defined an acceptable within-method error to be 20% or less and an acceptable between-methods error to be 30% or less, according to Critchley and Critchley. RESULTS: Forty measurements were performed with 16 participants. All measurements were included in the final analysis. The mean REE was 2478 ± 650 kcal/d for the GE system and 2166 ± 415 kcal/d for the Mindray system (P ˂ 0.0001), for a difference of 12.6%. This difference in REE is related to the variations between the two devices in both oxygen consumption and carbon dioxide production. CONCLUSIONS: The Mindray metabolic system, compared to the GE S/5 metabolic system (the reference method used), measured REE with a mean difference of 12.6%. The Mindray-measured REE was within an error limit we defined a priori.


Assuntos
Estado Terminal , Respiração Artificial , Metabolismo Basal , Calorimetria Indireta/métodos , Dióxido de Carbono/metabolismo , Estado Terminal/terapia , Metabolismo Energético , Humanos , Estudos Prospectivos , Reprodutibilidade dos Testes
10.
Proc Biol Sci ; 289(1975): 20220427, 2022 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-35611529

RESUMO

Many species up- or downregulate their resting metabolic rate (RMR) when they encounter favourable or unfavourable feeding conditions, respectively. This is thought to promote faster growth when food is abundant and conserve energy reserves when food is scarce. The time it takes to express metabolic plasticity remain little studied. Here, we develop a conceptual model showing how rapid or slow metabolic plasticity alter growth trajectories in response to changes in food supply. We test predictions from the model in a food manipulation experiment with young-of-the-year northern pike, Esox lucius, a species that experience drastic changes in food supply in nature. We find that metabolic plasticity is expressed gradually over several weeks in this species. Rapid changes in food supply thus caused apparent trait-environment mismatches that persisted for at least five weeks. Contrary to predictions, pike grew faster at high food levels when they had previously experienced low food levels and downregulated their RMR. This was not owing to increases in food intake but probably reflected that low RMRs increased the energetic scope for growth when feeding conditions improved. This highlights the important but complex effects of metabolic plasticity on growth dynamics under variable resource levels on ecologically relevant time scales.


Assuntos
Metabolismo Basal , Esocidae , Animais , Metabolismo Energético , Esocidae/metabolismo , Abastecimento de Alimentos
11.
BMC Womens Health ; 22(1): 171, 2022 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-35568898

RESUMO

BACKGROUND: The goal of this study is to clarify clinical, functional, and biochemical features of postmenopausal women who are at risk of developing osteosarcopenia. METHODS: This is a cross-sectional study undertaken to investigate the co-accordance of osteoporosis and sarcopenia and common risk factors on 305 postmenopausal Iranian women. Sarcopenia and osteoporosis were defined based on the European Working Group on sarcopenia in Older People guidelines and WHO criteria, respectively. Confounding factors including age, menopausal age, obesity, sun exposure, physical activity, macronutrient composition, and calcium and vitamin D supplementations were considered for all participants. A multivariate model was used to consider the common risk factors of both disorders; osteoporosis and sarcopenia. RESULTS: The mean age was 57.9 years ± 6.0 SD (range: 48-78 years) and 37.4% of patients were 60 years or older. Among all participants, 35.7% were obese (BMI ≥ 30 kg/m2). Approximately 45% of all the study population had insufficient physical activity and at least half of participants had insufficient intake of protein. There was a significant correlation between bone density and muscle mass and basal metabolic rate (BMR) (p < 0.01). In multivariate-multivariable regression model, after Bonferroni correction for obesity, lower BMR was the only one associated with both lower muscle mass and bone density in lumbar and hip sites (p < 0.007). CONCLUSIONS: Our data suggest that low BMR might be an early predictor for concordance of osteoporosis and sarcopenia in postmenopausal women.


Assuntos
Osteoporose , Sarcopenia , Idoso , Metabolismo Basal , Densidade Óssea/fisiologia , Estudos Transversais , Feminino , Humanos , Irã (Geográfico) , Pessoa de Meia-Idade , Obesidade/complicações , Osteoporose/epidemiologia , Pós-Menopausa , Sarcopenia/complicações , Sarcopenia/epidemiologia
12.
J Nutr Gerontol Geriatr ; 41(2): 126-139, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35502533

RESUMO

It is unclear which energy expenditure prediction equation should guide weight loss interventions in older adults with obesity. We ascertained the validity of four equations commonly used in practice in a series of weight loss studies of adults aged ≥65 with a body mass index ≥30kg/m2 using indirect calorimetry data. Diagnostic accuracy was defined as <10% discrepancy between predicted and measured resting metabolic rate (RMR). Mean was 73.4 years. RMR using the ReeVue was 1,643 kCal. With 59.0% accuracy, the WHO equation demonstrated the highest accuracy while the Harris-Benedict yielded 53.5% accuracy. The Owens equation demonstrated the least variability (21.5% overprediction, 27.8% underprediction) with 50.7% accuracy. A SECA bioimpedance analyzer noted the second lowest accuracy of 49.6%. Only 43.1% of measurements were within 10% of the gold-standard indirect calorimetry value using the Mifflin equation. All equations demonstrated <60% accuracy suggesting a great need for estimating energy needs.


Assuntos
Metabolismo Basal , Obesidade , Idoso , Índice de Massa Corporal , Metabolismo Energético , Humanos , Obesidade/metabolismo , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Perda de Peso
13.
Nutrients ; 14(10)2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35631136

RESUMO

Hormonal changes are caused by the menstrual cycle phases, which influence resting metabolic rate and eating behavior. The aim of the study was to determine resting metabolic rate (RMR) and its association with dietary intake according to the menstrual cycle phase in lean and obese Chilean women. This cross-sectional analytical study included 30 adult women (15 lean and 15 with obesity). Body composition was measured with a tetrapolar bioelectrical impedance meter. Nutritional status was determined by adiposity. A 24-h recall of three nonconsecutive days verifies dietary intake. The RMR was measured by indirect calorimetry. All measurements were performed in both the follicular and luteal phases of the menstrual cycle. Statistical analyses were performed with STATA software at a significance level, which was α = 0.05. The RMR (ß = 121.6 kcal/d), temperature (ß = 0.36 °C), calorie intake (ß = 317.1 kcal/d), and intake of lipids (ß = 13.8 g/d) were associated with the luteal phase in lean women. Only extracellular water (ß = 1.11%) and carbohydrate consumption (ß = 45.2 g/d) were associated in women with obesity. Lean women showed increased RMR, caloric intake, and lipid intake during the luteal phase. For women with obesity, carbohydrate intake increased but not RMR.


Assuntos
Metabolismo Basal , Fase Luteal , Adulto , Carboidratos , Estudos Transversais , Metabolismo Energético , Feminino , Humanos , Fase Luteal/metabolismo , Obesidade/metabolismo
14.
BMC Endocr Disord ; 22(1): 121, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35538513

RESUMO

BACKGROUND: Recent studies have shown that dietary carbohydrate quantity and quality as well as genetic variants may contribute to determining the metabolic rate and general and central obesity. This study aimed to examine interactions between melanocortin 4 receptor gene (MC4R) rs17782313 and dietary carbohydrate intake, glycemic index (GI), and glycemic load (GL) on body mass index (BMI), waist circumferences (WC), basal metabolic rate (BMR), and BMR/kg in overweight/obese women. METHODS: A total of 282 Iranian women (BMI ≥ 25) aged 18-56 years were enrolled in this cross-sectional study. All participants were assessed for blood parameters, body composition, BMR, and dietary intake. Dietary carbohydrate intake, GI, and GL were determined using a valid, reliable 147-item food frequency questionnaire. MC4R rs17782313 was genotyped by the restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: After adjustment for age and energy intake, significant interactions were observed between carbohydrate intake and MC4R rs17782313 in terms of BMI (P Interaction = 0.007), WC (P Interaction = 0.02), and BMR/kg (P Interaction = 0.003) in this way that higher carbohydrate intake, compared with lower intake, was associated with an increase in BMI and WC for individuals with C allele carriers (TC + CC genotypes), while related to an increase in BMR/kg for those carrying the TT genotype. No significant interaction was found between MC4R rs17782313 and GI and GL on BMI, WC, BMR/kg, and BMR. CONCLUSIONS: Interactions between the MC4R rs17782313 and carbohydrate intake probably can have an effect on BMI, WC, and BMR/kg in overweight/obese women.


Assuntos
Sobrepeso , Receptor Tipo 4 de Melanocortina , Metabolismo Basal/genética , Índice de Massa Corporal , Estudos Transversais , Carboidratos da Dieta , Feminino , Predisposição Genética para Doença , Humanos , Irã (Geográfico)/epidemiologia , Obesidade/complicações , Obesidade Abdominal/metabolismo , Sobrepeso/genética , Sobrepeso/metabolismo , Polimorfismo de Nucleotídeo Único , Receptor Tipo 4 de Melanocortina/genética , Receptor Tipo 4 de Melanocortina/metabolismo
15.
AAPS J ; 24(3): 67, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35538161

RESUMO

The objective of this study is to propose a unified, continuous, and bodyweight-only equation to quantify the changes of human basal metabolic rate (BMR), glomerular filtration rate (GFR), and drug clearance (CL) from infancy to adulthood. The BMR datasets were retrieved from a comprehensive historical database of male and female subjects (0.02 to 64 years). The CL datasets for 17 drugs and the GFR dataset were generated from published maturation and growth models with reported parameter values. A statistical approach was used to simulate the model-generated CL and GFR data for a hypothetical population with 26 age groups (from 0 to 20 years). A biphasic equation with two power-law functions of bodyweight was proposed and evaluated as a general model using nonlinear regression and dimensionless analysis. All datasets universally reveal biphasic curves with two distinct linear segments on log-log plots. The biphasic equation consists of two reciprocal allometric terms that asymptotically determine the overall curvature. The fitting results show a superlinear scaling phase (asymptotic exponent >1; ca. 1.5-3.5) and a sublinear scaling phase (asymptotic exponent <1; ca. 0.5-0.7), which are separated at the phase transition bodyweight ranging from 5 to 20 kg with a mean value of 10 kg (corresponding to 1 year of age). The dimensionless analysis generalizes and offers quantitative realization of the maturation and growth process. In conclusion, the proposed mixed-allometry equation is a generic model that quantitatively describes the phase transition in the human maturation process of diverse human functions.


Assuntos
Metabolismo Basal , Modelos Biológicos , Adolescente , Adulto , Peso Corporal , Criança , Pré-Escolar , Vias de Eliminação de Fármacos , Feminino , Taxa de Filtração Glomerular , Humanos , Lactente , Recém-Nascido , Masculino , Taxa de Depuração Metabólica , Adulto Jovem
16.
Cells ; 11(8)2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35456010

RESUMO

Obesity causes various complications such as type 2 diabetes, hypertension, fatty liver, cardiovascular diseases, and cancer. In a pilot GWAS study, we screened the DNAJC6 gene which is significantly related to the resting metabolic rate (RMR) in childhood obesity. With DNAJC6-overexpressed 3T3-L1 cells (TgHsp), we investigated the new obesity mechanism caused by an energy imbalance. After differentiation, lipid droplets (Oil red O staining) were not formed in TgHsp cells compared to the control. TgHsp preadipocyte fibroblast morphology was also not clearly observed in the cell morphology assay (DAPI/BODIPY). In TgHsp cells, the expression of PPARγ, C/EBPα, and aP2 (adipogenesis-related biomarkers) decreased 3-, 39-, and 200-fold, respectively. The expression of the adipokines leptin and adiponectin from adipose tissues also decreased 2.4- and 840-fold, respectively. In addition, the levels of pHSL(Ser563) and free glycerol, which are involved in lipolysis, were significantly lower in TgHsp cells than in the control. The reduction in insulin receptor expression in TgHsp cells suppressed insulin signaling systems such as AKT phosphorylation, and GLUT4 expression. Degradation of IRS-1 in 3T3-L1 adipocytes was caused by chronic exposure to insulin, but not TgHsp. Mitochondrial functions such as oxygen consumption and ATP production, as well as proton leak and UCP1 protein expression, decreased in TgHsp cells compared to the control. Moreover, autophagy was observed by increasing autophagosomal proteins, LC3, on Day 8 of differentiation in TgHsp cells. Through our first report on the DNAJC6 gene related to RMR, we found a new mechanism related to energy metabolism in obesity. DNAJC6 expression positively suppressed adipogenesis, leading to the subsequent resistance of lipolysis, adipokine expression, insulin signaling, and mitochondrial functions.


Assuntos
Adipogenia , Metabolismo Basal , Proteínas de Choque Térmico HSP40 , Células 3T3-L1 , Adipogenia/genética , Adipocinas , Animais , Proteínas de Choque Térmico HSP40/genética , Insulina/metabolismo , Camundongos
17.
Proc Biol Sci ; 289(1972): 20212747, 2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35414242

RESUMO

The enlarged brains of homeotherms bring behavioural advantages, but also incur high energy expenditures. The 'expensive brain' (EB) hypothesis posits that the energetic costs of the enlarged brain and the resulting increased cognitive abilities (CA) were met by either increased energy turnover or reduced allocation to other expensive organs, such as the gut. We tested the EB hypothesis by analysing correlated responses to selection in an experimental evolution model system, which comprises line types of laboratory mice selected for high or low basal metabolic rate (BMR), maximum (VO2max) metabolic rates and random-bred (unselected) lines. The traits are implicated in the evolution of homeothermy, having been pre-requisites for the encephalization and exceptional CA of mammals, including humans. High-BMR mice had bigger guts, but not brains, than mice of other line types. Yet, they were superior in the cognitive tasks carried out in both reward and avoidance learning contexts and had higher neuronal plasticity (indexed as the long-term potentiation) than their counterparts. Our data indicate that the evolutionary increase of CA in mammals was initially associated with increased BMR and brain plasticity. It was also fuelled by an enlarged gut, which was not traded off for brain size.


Assuntos
Metabolismo Basal , Metabolismo Energético , Animais , Metabolismo Basal/fisiologia , Evolução Biológica , Regulação da Temperatura Corporal , Encéfalo/metabolismo , Cognição , Mamíferos , Camundongos , Tamanho do Órgão/fisiologia
18.
Am J Physiol Endocrinol Metab ; 322(6): E508-E516, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35373585

RESUMO

Increased adiposity is associated with dysregulation of the endothelin system, both of which increase the risk of cardiovascular disease (CVD). Preclinical data indicate that endothelin dysregulation also reduces resting energy expenditure (REE). The objective was to test the hypothesis that endothelin receptor antagonism will increase REE in people with obesity compared with healthy weight individuals. Using a double blind, placebo-controlled, crossover design, 32 participants [healthy weight (HW): n = 16, BMI: 21.3 ± 2.8 kg/m2, age: 26 ± 7 yr and overweight/obese (OB): n = 16, BMI: 33.5 ± 9.5 kg/m2, age: 31 ± 6 yr] were randomized to receive either 125 mg of bosentan (ETA/B antagonism) or placebo twice per day for 3 days. Breath-by-breath gas exchange data were collected and REE was assessed by indirect calorimetry. Venous blood samples were analyzed for concentrations of endothelin-1 (ET-1). Treatment with bosentan increased plasma ET-1 in both OB and HW groups. Within the OB group, the changes in absolute REE (PLA: -77.6 ± 127.6 vs. BOS: 72.2 ± 146.6 kcal/day; P = 0.046). The change in REE was not different following either treatment in the HW group. Overall, absolute plasma concentrations of ET-1 following treatment with bosentan were significantly associated with kcal/day of fat (r = 0.488, P = 0.005), percentage of fat utilization (r = 0.415, P = 0.020), and inversely associated with the percentage of carbohydrates (r = -0.419, P = 0.019), and respiratory exchange ratio (r = -0.407, P = 0.023). Taken together, these results suggest that modulation of the endothelin system may represent a novel therapeutic approach to increase both resting metabolism and caloric expenditure, and reduce CVD risk in people with increased adiposity.NEW & NOTEWORTHY Findings from our current translational investigation demonstrate that dual endothelin A/B receptor antagonism increases total REE in overweight/obese individuals. These results suggest that modulation of the endothelin system may represent a novel therapeutic target to increase both resting metabolism and caloric expenditure, enhance weight loss, and reduce CVD risk in seemingly healthy individuals with elevated adiposity.


Assuntos
Adiposidade , Doenças Cardiovasculares , Adulto , Metabolismo Basal , Bosentana , Calorimetria Indireta , Endotelinas/metabolismo , Metabolismo Energético , Humanos , Obesidade/metabolismo , Sobrepeso/metabolismo , Receptores de Endotelina/metabolismo , Adulto Jovem
19.
Clin Nutr ; 41(5): 1073-1082, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35405584

RESUMO

BACKGROUND & AIMS: Predicting the risk of early limiting toxicity (ELT) is major challenge for the clinician seeking an effective, safe treatment for older patients with cancer. The Cancer and Aging Research Group (CARG) and CRASH (Chemotherapy Risk Assessment Scale for High-Age Patients) toxicity scores were designed to predict chemotherapy-related toxicity. Elevated resting energy expenditure (REE) may predispose to cachexia and increase ELT and mortality in older patients with cancer. The primary objective was to assess the association between elevated REE and ELT in older patients with cancer. The secondary objectives were to assess the discriminant ability of a predictive model including REE (relative to the CARG and CRASH scores) and the prognostic value of elevated REE. METHODS: We assessed patients aged 70 or over included in the prospective ELCAPA cohort between 2014 and 2018. The inclusion criteria were a solid tumour, a measurement of REE at baseline (mREE, by indirect calorimetry), and a geriatric assessment prior to cancer treatment in a teaching hospital (Paris, France). The mREE was compared with the predicted REE (pREE), as defined by the Harris-Benedict equation. Depending on the mREE/pREE ratio, study participants were classified as hypermetabolic, hypometabolic or normometabolic. The primary endpoint was 3-month ELT, defined as any unplanned hospitalization or any event leading to dose reduction, a treatment delay of more than 7 days, or treatment discontinuation within 3 months of initiation. The secondary endpoint was the 3-month mortality rate. RESULTS: A total of 179 patients were included. The median age was 80 [interquartile range: 76-84] years, 37% of the patients were female, 81.8% had metastatic disease, 67.6% received chemotherapy, 20.7% received hormone therapy, and 11.7% received targeted therapies. According to the mREE/pREE ratio, 85 patients (47%) were hypermetabolic, 63 (35%) were normometabolic, and 31 (18%) were hypometabolic. Sixty patients (33.5%; 95% confidence interval (CI): 26.7-40.9) experienced ELT. The discriminant ability (as assessed by the C-index) of a multivariate model including REE and adjustment factors was 0.82 [95%CI: 0.73-0.91]. In comparison, the discriminant ability of the CARG and CRASH models was 0.57 [0.45-0.68] and 0.51 [0.40-0.62], respectively. In our model, hypermetabolism was an independent risk factor for ELT (adjusted odds ratio = 2.44; 95%CI: 1.02-5.80). Other risk factors were the cancer type and stage, the treatment protocol, a clinical diagnosis of depression, the presence of grade 3 or 4 comorbidities, and the serum lactate dehydrogenase level. CONCLUSION: Hypermetabolism status is an independent predictor of ELT in older patients with cancer, relative to normometabolic status. Baseline REE measurement might improve the ELT risk assessment and decision-making process.


Assuntos
Metabolismo Basal , Neoplasias , Idoso , Idoso de 80 Anos ou mais , Calorimetria Indireta , Metabolismo Energético , Feminino , Humanos , Masculino , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Estudos Prospectivos
20.
J Comp Physiol B ; 192(3-4): 513-526, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35348882

RESUMO

Proper housing conditions are important aspects of animal welfare. Animals housed in enriched environments show less stereotypic behaviours than animals kept in barren cages. However, different types of cage enrichment may affect the results of experimental studies and hinder comparative analyses of animal physiology and behaviour. We investigated whether access to a running wheel, availability of nesting material, and pair housing affect basal metabolic rate (BMR) of Siberian hamsters (Phodopus sungorus) under various acclimation conditions. We used 70 adult hamsters (35 males and 35 females) divided into five groups housed under different cage conditions. All individuals experienced the same acclimation procedure: first a winter (L8:D16) then a summer (L16:D8) photoperiod, at air temperatures of first 20 °C then 7 °C under both photoperiods. We found that nesting material and pair housing did not affect hamster BMR, while access to a running wheel increased BMR and body mass regardless of photoperiod and ambient temperature. Thus, we suggest that cage enrichment should be applied with caution, especially in studies on energetics or thermoregulation, particularly in seasonal animals.


Assuntos
Metabolismo Basal , Phodopus , Animais , Metabolismo Basal/fisiologia , Peso Corporal , Cricetinae , Feminino , Masculino , Phodopus/fisiologia , Fotoperíodo , Estações do Ano
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