Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
Br J Nutr ; 109(9): 1573-89, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23433235

RESUMO

Of the environmental factors which have an impact on body weight, nutrients are most influential. Within normal limits, hypothalamic and related neuronal populations correct perturbations in energy metabolism, to return the body to its nutritional set-point, either through direct response to nutrients or indirectly via peripheral appetite signals. Excessive intake of certain macronutrients, such as simple carbohydrates and SFA, can lead to obesity and attendant metabolic dysfunction, also reflected in alterations in structural plasticity, and, intriguingly,neurogenesis, in some of these brain regions. Neurogenesis, previously thought to occur only in the embryo, is now known to take place in the adult brain, dependent on numerous stimulating and inhibiting factors, including dietary components. Because of classic associations between neurogenesis and the hippocampus, in learning and cognition, this brain region has also been the focus of attention in the study of links between diet and neurogenesis. Recently, however, a more complete picture of this relationship has been building: not only has the hypothalamus been shown to satisfy the criteria for a neurogenic niche, but appetite-related mediators, including circulating hormones, such as leptin and ghrelin, pro-inflammatory cytokines and the endocannabinoid intracellular messengers, are also being examined for their potential role in mediating neurogenic responses to macronutrients. The present review draws together these observations and investigates whether n-3 PUFA may exert their attenuating effects on body weight through the stimulation of adult neurogenesis. Exploration of the effects of nutraceuticals on neurogenic brain regions may encourage the development of new rational therapies in the fight against obesity.


Assuntos
Dieta , Metabolismo Energético , Neurogênese , Adulto , Humanos
2.
Lab Anim ; 56(5): 466-470, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35360986

RESUMO

The main objective of a post mortem is to identify, at a macroscopic level, any anatomical features that characterise mutant or sick mice and to describe lesions contributing to morbidity and mortality. Tissues collected for subsequent examination require appropriate handling and preservation to prevent deterioration. Therefore, efficient routine procedures are essential to facilitate histology and to ensure high-quality samples. In addition, optimised techniques minimise data loss from damaged samples reducing the numbers of animals used and supporting the 3Rs principle of reduction. Here, we describe an optimised method for tissue collection in the mouse. Training tips and points for caution are included.


Assuntos
Bancos de Tecidos , Animais , Camundongos , Autopsia/métodos , Modelos Animais de Doenças
3.
Curr Protoc ; 2(5): e428, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35617451

RESUMO

Histology is the study of the microscopic structure of tissues. This protocol permits the generation of frozen transverse sections of lumbar spinal cord regions L3 to L6. It enables counting of murine ventral horn lumbar motor neurons in a reproducible manner. Methods include spinal column dissection, hydraulic extrusion, and histological processing. The preparation for cryo-sectioning includes embedding lumbar spinal cord in optimal cutting temperature (OCT) medium. The correct orientation of the tissue is critical as calculating the amount of tissue to discard saved time overall. Specific details regarding section thickness and mounting are described. These requirements not only allow optimum coverage of specific regions but also ensure that no individual motor neuron was counted twice. The Nissl bodies of the motor neurons were stained using gallocyanin. The sections obtained are all of a comparable area and quality assurance is consistent. The specificity of the staining enables the scientist to identify and reliably quantify lumbar motor neurons. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Euthanasia of mouse and isolation of spinal cord Basic Protocol 2: Hydraulic extrusion of the spinal cord Basic Protocol 3: Identification of the lumbar region Basic Protocol 4: Embedding cord in OCT Basic Protocol 5: Collection of frozen sections onto slides Basic Protocol 6: Gallocyanin staining Basic Protocol 7: Motor neuron counting.


Assuntos
Neurônios Motores , Medula Espinal , Animais , Células do Corno Anterior , Região Lombossacral , Camundongos , Neurônios Motores/fisiologia
4.
Front Physiol ; 13: 953199, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36091365

RESUMO

Background: Increased waist-to-hip ratio (WHR) is associated with increased mortality and risk of type 2 diabetes and cardiovascular disease. The TBX15-WARS2 locus has consistently been associated with increased WHR. Previous study of the hypomorphic Wars2 V117L/V117L mouse model found phenotypes including severely reduced fat mass, and white adipose tissue (WAT) browning, suggesting Wars2 could be a potential modulator of fat distribution and WAT browning. Methods: To test for differences in browning induction across different adipose depots of Wars2 V117L/V117L mice, we measured multiple browning markers of a 4-month old chow-fed cohort in subcutaneous and visceral WAT and brown adipose tissue (BAT). To explain previously observed fat mass loss, we also tested for the upregulation of plasma mitokines FGF21 and GDF15 and for differences in food intake in the same cohort. Finally, to test for diet-associated differences in fat distribution, we placed Wars2 V117L/V117L mice on low-fat or high-fat diet (LFD, HFD) and assessed their body composition by Echo-MRI and compared terminal adipose depot weights at 6 months of age. Results: The chow-fed Wars2 V117L/V117L mice showed more changes in WAT browning marker gene expression in the subcutaneous inguinal WAT depot (iWAT) than in the visceral gonadal WAT depot (gWAT). These mice also demonstrated reduced food intake and elevated plasma FGF21 and GDF15, and mRNA from heart and BAT. When exposed to HFD, the Wars2 V117L/V117L mice showed resistance to diet-induced obesity and a male and HFD-specific reduction of gWAT: iWAT ratio. Conclusion: Severe reduction of Wars2 gene function causes a systemic phenotype which leads to upregulation of FGF21 and GDF15, resulting in reduced food intake and depot-specific changes in browning and fat mass.

5.
Sci Rep ; 9(1): 18779, 2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31827172

RESUMO

The analysis of volatile organic compounds (VOCs) as a non-invasive method for disease monitoring, such as type 2 diabetes (T2D) has shown potential over the years although not yet set in clinical practice. Longitudinal studies to date are limited and the understanding of the underlying VOC emission over the age is poorly understood. This study investigated longitudinal changes in VOCs present in faecal headspace in two mouse models of T2D - Cushing's syndrome and single Afmid knockout mice. Longitudinal changes in bodyweight, blood glucose levels and plasma insulin concentration were also reported. Faecal headspace analysis was carried out using selected ion flow tube mass spectrometry (SIFT-MS) and thermal desorption coupled to gas chromatography-mass spectrometry (TD-GC-MS). Multivariate data analysis of the VOC profile showed differences mainly in acetic acid and butyric acid able to discriminate the groups Afmid and Cushing's mice. Moreover, multivariate data analysis revealed statistically significant differences in VOCs between Cushing's mice/wild-type (WT) littermates, mainly short-chain fatty acids (SCFAs), ketones, and alcohols, and longitudinal differences mainly attributed to methanol, ethanol and acetone. Afmid mice did not present statistically significant differences in their volatile faecal metabolome when compared to their respective WT littermates. The findings suggested that mice developed a diabetic phenotype and that the altered VOC profile may imply a related change in gut microbiota, particularly in Cushing's mice. Furthermore, this study provided major evidence of age-related changes on the volatile profile of diabetic mice.


Assuntos
Arilformamidase/metabolismo , Síndrome de Cushing/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Metaboloma , Compostos Orgânicos Voláteis/metabolismo , Animais , Arilformamidase/genética , Glicemia/metabolismo , Síndrome de Cushing/diagnóstico , Diabetes Mellitus Experimental/diagnóstico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/diagnóstico , Fezes , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Microbioma Gastrointestinal , Insulina/sangue , Estudos Longitudinais , Masculino , Camundongos , Camundongos Knockout , Monitorização Fisiológica , Análise Multivariada , Obesidade/metabolismo
6.
Nat Genet ; 50(4): 572-580, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29632379

RESUMO

Individual risk of type 2 diabetes (T2D) is modified by perturbations to the mass, distribution and function of adipose tissue. To investigate the mechanisms underlying these associations, we explored the molecular, cellular and whole-body effects of T2D-associated alleles near KLF14. We show that KLF14 diabetes-risk alleles act in adipose tissue to reduce KLF14 expression and modulate, in trans, the expression of 385 genes. We demonstrate, in human cellular studies, that reduced KLF14 expression increases pre-adipocyte proliferation but disrupts lipogenesis, and in mice, that adipose tissue-specific deletion of Klf14 partially recapitulates the human phenotype of insulin resistance, dyslipidemia and T2D. We show that carriers of the KLF14 T2D risk allele shift body fat from gynoid stores to abdominal stores and display a marked increase in adipocyte cell size, and that these effects on fat distribution, and the T2D association, are female specific. The metabolic risk associated with variation at this imprinted locus depends on the sex both of the subject and of the parent from whom the risk allele derives.


Assuntos
Adipócitos/patologia , Composição Corporal/genética , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patologia , Fatores de Transcrição Sp/genética , Alelos , Animais , Distribuição da Gordura Corporal , Tamanho Celular , Elementos Facilitadores Genéticos , Feminino , Expressão Gênica , Estudo de Associação Genômica Ampla , Impressão Genômica , Humanos , Fatores de Transcrição Kruppel-Like/deficiência , Fatores de Transcrição Kruppel-Like/genética , Lipogênese/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Fatores de Risco , Caracteres Sexuais
8.
J Obes ; 2016: 7127898, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27747100

RESUMO

Introduction. Obesity is increasingly common and is associated with an increased prevalence of cardiac arrhythmias. The aim of this study was to see whether in obesity there is proarrhythmic gene expression of ventricular ion channels and related molecules. Methods and Results. Rats were fed on a high-fat diet and compared to control rats on a normal diet (n = 8). After 8 weeks, rats on the high-fat diet showed significantly greater weight gain and higher adiposity. Left ventricle samples were removed at 8 weeks and mRNA expression of ion channels and other molecules was measured using qPCR. Obese rats had significant upregulation of Cav1.2, HCN4, Kir2.1, RYR2, NCX1, SERCA2a, and RYR2 mRNA and downregulation of ERG mRNA. In the case of HCN4, it was confirmed that there was a significant increase in protein expression. The potential effects of the mRNA changes on the ventricular action potential and intracellular Ca2+ transient were predicted using computer modelling. Modelling predicted prolongation of the ventricular action potential and an increase in the intracellular Ca2+ transient, both of which would be expected to be arrhythmogenic. Conclusion. High-fat diet causing obesity results in arrhythmogenic cardiac gene expression of ion channels and related molecules.


Assuntos
Arritmias Cardíacas/genética , Canais de Cálcio/genética , Ventrículos do Coração/metabolismo , Obesidade/genética , Animais , Arritmias Cardíacas/etiologia , Canais de Cálcio/metabolismo , Gorduras na Dieta/administração & dosagem , Regulação da Expressão Gênica , Masculino , Obesidade/complicações , Reação em Cadeia da Polimerase , Ratos , Ratos Wistar
9.
Biol Open ; 4(11): 1367-75, 2015 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-26432886

RESUMO

Tryptophan metabolites have been linked in observational studies with type 2 diabetes, cognitive disorders, inflammation and immune system regulation. A rate-limiting enzyme in tryptophan conversion is arylformamidase (Afmid), and a double knockout of this gene and thymidine kinase (Tk) has been reported to cause renal failure and abnormal immune system regulation. In order to further investigate possible links between abnormal tryptophan catabolism and diabetes and to examine the effect of single Afmid knockout, we have carried out metabolic phenotyping of an exon 2 Afmid gene knockout. These mice exhibit impaired glucose tolerance, although their insulin sensitivity is unchanged in comparison to wild-type animals. This phenotype results from a defect in glucose stimulated insulin secretion and these mice show reduced islet mass with age. No evidence of a renal phenotype was found, suggesting that this published phenotype resulted from loss of Tk expression in the double knockout. However, despite specifically removing only exon 2 of Afmid in our experiments we also observed some reduction of Tk expression, possibly due to a regulatory element in this region. In summary, our findings support a link between abnormal tryptophan metabolism and diabetes and highlight beta cell function for further mechanistic analysis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA