Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 502
Filtrar
1.
Nat Commun ; 11(1): 5355, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33097705

RESUMO

Water and lipids are key participants in many biological processes, but there are few non-invasive methods that provide quantification of these components in vivo, and none that can isolate and quantify lipids in the blood. Here we develop a new imaging modality termed shortwave infrared meso-patterned imaging (SWIR-MPI) to provide label-free, non-contact, spatial mapping of water and lipid concentrations in tissue. The method utilizes patterned hyperspectral illumination to target chromophore absorption bands in the 900-1,300 nm wavelength range. We use SWIR-MPI to monitor clinically important physiological processes including edema, inflammation, and tumor lipid heterogeneity in preclinical models. We also show that SWIR-MPI can spatially map blood-lipids in humans, representing an example of non-invasive and contact-free measurements of in vivo blood lipids. Together, these results highlight the potential of SWIR-MPI to enable new capabilities in fundamental studies and clinical monitoring of major conditions including obesity, cancer, and cardiovascular disease.


Assuntos
Raios Infravermelhos , Lipídeos/sangue , Imagem Óptica/métodos , Ondas de Rádio , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Água/análise , Tecido Adiposo Marrom/diagnóstico por imagem , Tecido Adiposo Marrom/patologia , Adulto , Animais , Biomarcadores/sangue , Doenças Cardiovasculares/diagnóstico por imagem , Edema/diagnóstico por imagem , Edema/patologia , Feminino , Xenoenxertos , Humanos , Inflamação/diagnóstico por imagem , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Obesidade/diagnóstico por imagem , Imagem Óptica/instrumentação , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação
2.
Toxicol Lett ; 334: 27-35, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32956827

RESUMO

Methyl- and propyl- parabens are generally regarded as safe by the U.S Food and Drug Administration and as such are commonly used in personal care products. These parabens have been associated with increased white adipogenesis in vitro and methyl paraben also increased the white adipose mass of mice. Given brown adipose also plays a role in energy balance, we sought to evaluate whether the effects of methyl- and propyl- parabens on white adipocytes extended to brown adipocytes. We challenged white and brown pre-adipocytes at low doses of both parabens (up to 1 µM) during the differentiation process and examined adipogenesis with the ORO assay. The impact of each paraben on glucose uptake and lipolytic activity of adipocytes were measured with a fluorescent glucose analog and enzymatically, respectively. Methyl- and propyl- parabens increased adipogenesis of 3T3-L1 white adipocytes but not brown adipocytes. In white adipocytes, methyl paraben increased glucose uptake and both parabens reduced basal lipolysis. However, in brown adipocytes, parabens had no effect on basal lipolysis and instead attenuated isoproterenol induced lipolysis. These data indicate that methyl- and propyl- parabens target the differentiation and metabolic processes of multiple types of adipocytes in a cell autonomous manner.


Assuntos
Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Parabenos/toxicidade , Conservantes Farmacêuticos/toxicidade , Células 3T3-L1 , Adipócitos/metabolismo , Adipócitos/patologia , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Animais , Diferenciação Celular/efeitos dos fármacos , Cosméticos , Glucose/metabolismo , Lipólise/efeitos dos fármacos , Camundongos
3.
Cardiovasc Pathol ; 49: 107259, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32692664

RESUMO

Perivascular adipose tissue (PVAT) is a fat tissue deposit that encircles the vasculature. PVAT is traditionally known to protect the vasculature from external stimuli that could cause biological stress. In addition to the protective role of PVAT, it secretes certain biologically active substances known as adipokines that induce paracrine effects on proximate blood vessels. These adipokines influence vascular tones. There are different types of PVAT and they are phenotypically and functionally distinct. These are the white and brown PVATs. Under certain conditions, white PVAT could undergo phenotypic switch to attain a brown PVAT-like phenotype. This type of PVAT is referred to as Beige PVAT. The morphology of adipose tissue is influenced by species, age, and sex. These factors play significant roles in adipose tissue mass, functionality, paracrine activity, and predisposition to vascular diseases. The difficulty that is currently experienced in extrapolating animal models to human physiology could be traceable to these factors. Up till now, the involvement of PVAT in the development of vascular pathology is still not well understood. Brown and white PVAT contribute differently to vascular pathology. Thus, the PVAT could be a therapeutic target in curbing certain vascular diseases. In this review, knowledge would be updated on the multifaceted involvement of PVAT in vascular pathology and also explore its vascular therapeutic potential.


Assuntos
Tecido Adiposo Bege/patologia , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/patologia , Artérias/patologia , Doenças Vasculares/patologia , Adipocinas/metabolismo , Tecido Adiposo Bege/efeitos dos fármacos , Tecido Adiposo Bege/metabolismo , Tecido Adiposo Bege/fisiopatologia , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/fisiopatologia , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/fisiopatologia , Adiposidade , Animais , Artérias/efeitos dos fármacos , Artérias/metabolismo , Artérias/fisiopatologia , Fármacos Cardiovasculares/uso terapêutico , Hemodinâmica , Humanos , Mediadores da Inflamação/metabolismo , Comunicação Parácrina , Transdução de Sinais , Doenças Vasculares/tratamento farmacológico , Doenças Vasculares/metabolismo , Doenças Vasculares/fisiopatologia
4.
Nat Commun ; 11(1): 1517, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32251290

RESUMO

Leptin stimulates the sympathetic nervous system (SNS), energy expenditure, and weight loss; however, the underlying molecular mechanism remains elusive. Here, we uncover Sh2b1 in leptin receptor (LepR) neurons as a critical component of a SNS/brown adipose tissue (BAT)/thermogenesis axis. LepR neuron-specific deletion of Sh2b1 abrogates leptin-stimulated sympathetic nerve activation and impairs BAT thermogenic programs, leading to reduced core body temperature and cold intolerance. The adipose SNS degenerates progressively in mutant mice after 8 weeks of age. Adult-onset ablation of Sh2b1 in the mediobasal hypothalamus also impairs the SNS/BAT/thermogenesis axis; conversely, hypothalamic overexpression of human SH2B1 has the opposite effects. Mice with either LepR neuron-specific or adult-onset, hypothalamus-specific ablation of Sh2b1 develop obesity, insulin resistance, and liver steatosis. In contrast, hypothalamic overexpression of SH2B1 protects against high fat diet-induced obesity and metabolic syndromes. Our results unravel an unrecognized LepR neuron Sh2b1/SNS/BAT/thermogenesis axis that combats obesity and metabolic disease.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Fígado Gorduroso/patologia , Resistência à Insulina , Neurônios/metabolismo , Obesidade/patologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Tecido Adiposo Marrom/inervação , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Animais , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Fígado Gorduroso/etiologia , Feminino , Técnicas de Introdução de Genes , Técnicas de Inativação de Genes , Humanos , Hipotálamo/patologia , Leptina/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Transgênicos , Obesidade/etiologia , Receptores para Leptina/metabolismo , Sistema Nervoso Simpático/fisiologia , Termogênese/fisiologia
5.
Korean J Radiol ; 21(2): 248-256, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31997600

RESUMO

OBJECTIVE: The purpose of the study was to non-invasively characterize and discriminate brown adipose tissue (BAT) from white adipose tissue (WAT) in rats using spectral computed tomography (CT) with histological validation. MATERIALS AND METHODS: A lipid-containing phantom (lipid fractions from 0% to 100%) was imaged with spectral CT. An in vivo, non-enhanced spectral CT scan was performed on 24 rats, and fat concentrations of BAT and WAT were measured. The rats were randomized to receive intraperitoneal treatment with norepinephrine (NE) (n = 12) or saline (n = 12). Non-enhanced and enhanced spectral CT scans were performed after treatment to measure the elevation of iodine in BAT and WAT. The BAT/aorta and WAT/aorta ratios were calculated and compared, after which isolated BAT and WAT samples were subjected to histological and uncoupling protein 1 (UCP1) analyses. RESULTS: The ex-vivo phantom study showed excellent linear fit between measured fat concentration and the known gravimetric reference standard (r² = 0.996). In vivo, BAT had significantly lower fat concentration than WAT (p < 0.001). Compared to the saline group, the iodine concentration of BAT increased significantly (p < 0.001) after injection of NE, while the iodine concentration of WAT only changed slightly. The BAT/aorta ratio also increased significantly after exposure to NE compared to the saline group (p < 0.001). Histological and UCP1 expression analyses supported the spectral CT imaging results. CONCLUSION: The study consolidates spectral CT as a new approach for non-invasive imaging of BAT and WAT. Quantitative analyses of BAT and WAT by spectral CT revealed different characteristics and pharmacologic activations in the two types of adipose tissue.


Assuntos
Tecido Adiposo Marrom/diagnóstico por imagem , Tecido Adiposo Branco/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/patologia , Animais , Processamento de Imagem Assistida por Computador , Injeções Intraperitoneais , Masculino , Norepinefrina/farmacologia , Ratos , Ratos Wistar , Proteína Desacopladora 1/metabolismo
6.
Eur J Radiol ; 123: 108777, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31855655

RESUMO

PURPOSE: To characterize brown adipose tissue (BAT) in polycystic ovary syndrome (PCOS) patients in comparison to healthy subjects using Z-spectral imaging (ZSI). METHOD: ZSI data were collected on 19 normal control females (NCF), 17 males (NCM), and 13 PCOS patients. By fitting to multiple Lorentzian functions, ZSI provides fat-water fraction (FWF) of tissue in the supraclavicular area that can be used to differentiate between white adipose tissue (WAT), BAT, and muscle. The fraction of BAT over the total fat depot (BATf) and the average FWF in BAT or FWF(BAT) were then computed, reflecting relative BAT mass and BAT metabolism respectively. The parameters were compared among the three groups, and the correlations to Body Mass Index (BMI) were also quantified. RESULTS: There was an inverse correlation between BATf and BMI in normal subjects. The BATf of the PCOS group was significantly smaller than the NCF (P < 0.001). On the other hand, FWF(BAT) correlated linearly with BMI in healthy subjects. The PCOS group had higher FWF(BAT) than the NCF group (P < 0.001). CONCLUSIONS: Normal subjects with higher BMI show less BATf and have increased FWF(BAT), indicating relatively higher level of metabolic passive WAT depot and relatively reduced metabolism in their BAT depots. PCOS patients have the least BATf and the highest FWF(BAT), suggesting decreased BAT mass and function in PCOS. Novel imaging technique with ZSI for the characterization of BAT mass and function in PCOS may help to monitor treatment responses of PCOS therapies.


Assuntos
Tecido Adiposo Marrom/diagnóstico por imagem , Síndrome do Ovário Policístico/fisiopatologia , Termogênese/fisiologia , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/diagnóstico por imagem , Tecido Adiposo Branco/patologia , Adulto , Análise de Variância , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino
7.
Molecules ; 24(24)2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31817377

RESUMO

Many anti-obesity chemicals have been withdrawn from the market due to serious adverse reactions, and the researchers have turned their attention to low-toxic natural products. Previous studies have demonstrated that chitosan (CTS) and chitosan oligosaccharide (COS) were low-toxic natural products for the use of weight loss. However, it is still unclear whether CTS and COS have positive effects on the thermogenesis. In this study, CTS and COS significantly reduced the weight gain of rats without affecting food intake and effectively inhibited adipose tissue hypertrophy and hyperplasia. Consistently, CTS and COS significantly increased the thermogenic capacity of obese rats induced by high-fat diet (HFD) and increased the expression of browning genes and proteins (UCP1, PGC1α, PRMD16, and ATF2) in white adipose tissue (WAT) and brown adipose tissue (BAT). In vitro, COS inhibited the formation of mature adipocytes and increased the expression of browning genes. In conclusion, COS and CTS was used to explore the function and mechanism on thermogenesis, and CTS and COS can increase the browning of WAT and the thermogenesis of BAT to inhibit obesity. This effect may be achieved by promoting the expression of browning and thermogenic genes, providing new ideas for the utilization of COS and CTS.


Assuntos
Tecido Adiposo Marrom , Tecido Adiposo Branco , Quitosana , Obesidade/tratamento farmacológico , Oligossacarídeos , Termogênese/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Animais , Quitosana/química , Quitosana/farmacologia , Dieta Hiperlipídica/efeitos adversos , Epididimo/metabolismo , Epididimo/patologia , Masculino , Obesidade/induzido quimicamente , Obesidade/metabolismo , Obesidade/patologia , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Ratos , Ratos Sprague-Dawley
8.
Commun Biol ; 2: 389, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31667363

RESUMO

Billions of people have obesity-related metabolic syndromes such as diabetes and hyperlipidemia. Promoting the browning of white adipose tissue has been suggested as a potential strategy, but a drug still needs to be identified. Here, genetic deletion of activating transcription factor 3 (ATF3 -/- ) in mice under a high-fat diet (HFD) resulted in obesity and insulin resistance, which was abrogated by virus-mediated ATF3 restoration. ST32da, a synthetic ATF3 inducer isolated from Salvia miltiorrhiza, promoted ATF3 expression to downregulate adipokine genes and induce adipocyte browning by suppressing the carbohydrate-responsive element-binding protein-stearoyl-CoA desaturase-1 axis. Furthermore, ST32da increased white adipose tissue browning and reduced lipogenesis in HFD-induced obese mice. The anti-obesity efficacy of oral ST32da administration was similar to that of the clinical drug orlistat. Our study identified the ATF3 inducer ST32da as a promising therapeutic drug for treating diet-induced obesity and related metabolic disorders.


Assuntos
Fator 3 Ativador da Transcrição/metabolismo , Adipócitos Marrons/metabolismo , Obesidade/metabolismo , Células 3T3-L1 , Fator 3 Ativador da Transcrição/deficiência , Fator 3 Ativador da Transcrição/genética , Adipócitos Marrons/patologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Animais , Fármacos Antiobesidade/farmacologia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Regulação da Temperatura Corporal/fisiologia , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Humanos , Resistência à Insulina , Lipogênese/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/genética , Obesidade/prevenção & controle , Orlistate/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Salvia miltiorrhiza/química
9.
Int J Mol Sci ; 20(21)2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31652943

RESUMO

Shortening of poly(A) tails triggers mRNA degradation; hence, mRNA deadenylation regulates many biological events. In the present study, we generated mice lacking the Cnot1 gene, which encodes an essential scaffold subunit of the CCR4-NOT deadenylase complex in adipose tissues (Cnot1-AKO mice) and we examined the role of CCR4-NOT in adipocyte function. Cnot1-AKO mice showed reduced masses of white adipose tissue (WAT) and brown adipose tissue (BAT), indicating abnormal organization and function of those tissues. Indeed, Cnot1-AKO mice showed hyperinsulinemia, hyperglycemia, insulin resistance, and glucose intolerance and they could not maintain a normal body temperature during cold exposure. Muscle-like fibrous material appeared in both WAT and BAT of Cnot1-AKO mice, suggesting the acquisition of non-adipose tissue characteristics. Gene expression analysis using RNA-sequencing (RNA-seq) showed that the levels of adipose tissue-related mRNAs, including those of metabolic genes, decreased, whereas the levels of inflammatory response-related mRNAs increased. These data suggest that the CCR4-NOT complex ensures proper adipose tissue function by maintaining adipocyte-specific mRNAs at appropriate levels and by simultaneously suppressing mRNAs that would impair adipocyte function if overexpressed.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Fatores de Transcrição/genética , Adipócitos/citologia , Adipócitos/metabolismo , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/patologia , Animais , Temperatura Corporal , Células Cultivadas , Regulação da Expressão Gênica , Hiperglicemia/etiologia , Hiperglicemia/metabolismo , Hiperinsulinismo/etiologia , Hiperinsulinismo/metabolismo , Metabolismo dos Lipídeos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro/metabolismo , Fatores de Transcrição/deficiência
10.
Ann Endocrinol (Paris) ; 80(5-6): 314-318, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31606198

RESUMO

INTRODUCTION: Excess catecholamine stimulates heat production in brown adipose tissue (BAT). Activation of BAT can be detected in patients presenting pheochromocytoma. CASE STUDY: A 58-year-old female patient sought medical advice due to 13 kg weight loss over 2 years accompanied by sweating and high blood pressure. Thoracic-abdominal-pelvic CT-scan revealed a solid 40 mm mass in the left adrenal compartment with peri-adrenal nodules and a solid 80 mm mass at the lower end of the right kidney. 18FDG-PET scan exhibited intense uptake in the supraclavicular, intercostal, mediastinal, peri-renal, mesenteric, iliac and inguinal spaces. Renal tumor with locoregional infiltration and remote metastases was initially considered. Diagnosis of pheochromocytoma was subsequently confirmed by a 10-fold increase in urinary catecholamine, metanephrine and normetanephrine levels. Left adrenalectomy confirmed the diagnosis of pheochromocytoma, with 3 lymph-node metastases in the adjacent adipose tissue surrounded by brown fat. The patient was clinically asymptomatic with normal blood pressure at 3 months post-surgery. A weight gain of 6 kg was recorded, with normalisation of catecholamines/metanephrine/normetanephrine levels. Bilateral peri-renal infiltration (including the right renal mass) disappeared on CT-scan, and TEP-18-FDG no longer showed hypermetabolism. Recurrent mediastinal metastases were diagnosed 6 months after surgery. CONCLUSION: Brown fat activation may mislead diagnosis of pheochromocytoma, suggesting multi-metastatic extra-adrenal tumor, if clinicians are not aware of it.


Assuntos
Tecido Adiposo Marrom/fisiologia , Neoplasias das Glândulas Suprarrenais/diagnóstico , Feocromocitoma/diagnóstico , Perda de Peso , Tecido Adiposo Marrom/patologia , Neoplasias das Glândulas Suprarrenais/patologia , Neoplasias das Glândulas Suprarrenais/fisiopatologia , Adrenalectomia , Catecolaminas/urina , Feminino , Humanos , Hipertensão , Metástase Linfática/patologia , Pessoa de Meia-Idade , Metástase Neoplásica/diagnóstico , Feocromocitoma/patologia , Feocromocitoma/fisiopatologia , Tomografia por Emissão de Pósitrons , Sudorese , Tomografia Computadorizada por Raios X
11.
Life Sci ; 237: 116914, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31622606

RESUMO

AIMS: The aim of the presente study was to examine the effects of oral gallic acid (GA) administration on the brown adipose tissue of obese mice fed with high-fat diet. New mechanisms and interactions pathways in thermogenesis were accessed through bioinformatics analyses. MAIN METHODS: Swiss male mice were divided into four groups and fed during 60 days with: standard diet, standard diet combined with gallic acid, high-fat diet and high-fat diet combined with gallic acid. Body weight, food intake, and blood parameters (glucose tolerance test, total-cholesterol, high-density low-c, triglyceride and glucose levels) were evaluated. Brown and subcutaneous white adipose tissue histological analysis were performed. SIRT1 and PGC1-α mRNA expression in the brown adipose tissue were assessed. KEY FINDINGS: Our main findings showed that the gallic acid improved glucose tolerance and metabolic parameters. These results were accompanied by bioinformatics analyses that evidenced SIRT1 as main target in the thermogenesis process, confirmed as increased SIRT1 mRNA expression was evidenced in the brown adipose tissue. SIGNIFICANCE: Together, the data suggest that the gallic acid effect in brown adipose tissue may improve body metabolism, glucose homeostasis and increase thermogenesis.


Assuntos
Tecido Adiposo Marrom/metabolismo , Biologia Computacional/métodos , Dieta Hiperlipídica/efeitos adversos , Ácido Gálico/farmacologia , Metaboloma/efeitos dos fármacos , Obesidade/metabolismo , Sirtuína 1/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/patologia , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Obesos , Obesidade/tratamento farmacológico , Obesidade/etiologia , Sirtuína 1/genética , Termogênese/efeitos dos fármacos
12.
Eur J Pharmacol ; 863: 172708, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31568785

RESUMO

Obesity is a serious public health problem characterized by abnormal or excessive fat accumulation, which is caused by an energy imbalance between calories consumed and calories expended. MiRNAs have been involved in the regulation of occurrence and progression of obesity. This study aims to investigate the role of miR-324-5p in regulating the adipose tissue mass and preliminarily probe into its effect on progression of obesity. MiR-324-5p was upregulated in the epididymal white adipose tissues (eWAT), inguinal white adipose tissues (iWAT) and brown adipose tissues (BAT) of the mice fed with high fat diet (HFD). Under room temperature (RT) or thermoneutrality (TN) condition, when tail intravenously injected with miR-324-5p antagomir (anta-miR-324-5p), the fat mass and total weight of mice were both significantly suppressed. The suppressive effect was more distinct under TN than RT. The weight of iWAT and BAT were both inhibited by anta-miR-324-5p under TN. Moreover, PM20D1 was a direct target gene of miR-324-5p. In primary iWAT cells, the expression of PM20D1 was significantly increased by anta-miR-324-5p, whereas decreased by the miR-324-5p mimic. Furthermore, anta-miR-324-5p noticeably increased the cellular oxygen consumption in primary BAT and iWAT cells. Our findings indicated that inhibition of miR-324-5p increased PM20D1-mediated fat consumption and reduced body weight in mice, suggesting that miR-324-5p may be a novel therapeutic target against obesity.


Assuntos
Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/citologia , Tecido Adiposo Branco/metabolismo , Amidoidrolases/metabolismo , Peso Corporal/genética , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/patologia , Amidoidrolases/genética , Animais , Antagomirs/genética , Progressão da Doença , Camundongos , Camundongos Endogâmicos BALB C , Obesidade/genética , Obesidade/metabolismo , Obesidade/patologia , Consumo de Oxigênio/genética , Termogênese/genética , Regulação para Cima/genética
14.
Acta Diabetol ; 56(12): 1333-1339, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31506721

RESUMO

AIMS: This study aimed to evaluate the effect of pioglitazone on brown adipose tissue function and hypothalamic gliosis in humans. Brown adipose tissue and the hypothalamus are regarded as important potential pharmacological targets to metabolic diseases, and defining the impact of current therapies on their structure and/or function could provide therapeutic advance in this field. METHODS: Six patients with type 2 diabetes were treated for 24 weeks with pioglitazone 30 mg/day as an add-on therapy. Brown adipose tissue glucose uptake and volume were determined using 18F-FDG PET/CT scans; hypothalamic gliosis was determined using MRI scans; blood was collected for hormone and biochemistry measurements. All tests were performed at inclusion and six months after pioglitazone introduction. RESULTS: Pioglitazone treatment led to a significant 3% body mass increase. There were neither changes in cold-induced brown adipose tissue glucose uptake and volume nor changes in hypothalamic gliosis. CONCLUSIONS: This is a proof-of-concept study that provides clinical evidence for a lack of action of a thiazolidinedione, pioglitazone, to promote homogeneous and measurable changes in brown adipose tissue volume and also in hypothalamic gliosis after 6 months of treatment.


Assuntos
Tecido Adiposo Marrom/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Gliose/prevenção & controle , Hipotálamo/efeitos dos fármacos , Hipotálamo/patologia , Pioglitazona/farmacologia , Tecido Adiposo Marrom/diagnóstico por imagem , Tecido Adiposo Marrom/patologia , Adulto , Idoso , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/patologia , Quimioterapia Combinada , Feminino , Fluordesoxiglucose F18 , Gliose/diagnóstico , Gliose/patologia , Humanos , Hipotálamo/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/diagnóstico , Obesidade/tratamento farmacológico , Obesidade/patologia , Tamanho do Órgão/efeitos dos fármacos , Sobrepeso/complicações , Sobrepeso/diagnóstico , Sobrepeso/tratamento farmacológico , Sobrepeso/patologia , Pioglitazona/administração & dosagem , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Estudo de Prova de Conceito , Tiazolidinedionas/administração & dosagem , Tiazolidinedionas/farmacologia
15.
Endocr J ; 66(10): 923-936, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31292308

RESUMO

Promoting brown adipose tissue (BAT) formation and function reduces obesity. Ellagic Acid (EA), located abundantly in plant extracts and fruits, has been shown to modulate formation and differentiation of adipocytes, although its role in the process of browning of white adipose tissue (WAT) has not been elucidated. In this study, fifty-six five-week old SD rats were randomly assigned to receive normal diet (ND, 10% lipids) or high-fat diet (HFD, 60% lipid) with or without various dosages of EA for 24 weeks. Our results showed that high fat diet intake triggered overweight, glucose intolerance and white adipocyte hypertrophy, the effects of which were mitigated by EA treatment. Meanwhile, EA supplementation reduced serum resistin levels, improved hepatic steatosis and serum lipid profile in DIO (high fat diet induced obesity) rats. Moreover, EA supplementation significantly decreased mRNA expression of Zfp423 and Aldh1a1, the key determinants of WAT plasticity. EA also increased mRNA expression of brown adipocyte markers including UCP1, PRDM16, Cidea, PGC1α, Ppar-α; beige markers including CD137and TMEM26; mitochondrial biogenesis markers including TFAM in inguinal WAT (iWAT) when compared to their counterparts. EA treatment significantly improved mitochondrial function, as measured by citrate synthase activity. More importantly, EA markedly elevated the expression of UCP1 in iWAT, which is a specific protein of brown adipocyte. In conclusion, our results provided evidence that EA improved obesity-induced dyslipidemia and hepatic steatosis in DIO rats via browning of iWAT through suppressing white adipocyte maintaining genes and promoting expression of key thermogenic genes. These findings suggest that EA could be a promising therapeutic avenue to treat metabolic diseases.


Assuntos
Adipócitos Brancos/efeitos dos fármacos , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/patologia , Ácido Elágico/administração & dosagem , Obesidade/tratamento farmacológico , Obesidade/patologia , Adipócitos Brancos/fisiologia , Tecido Adiposo Branco/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Citrato (si)-Sintase/metabolismo , Dieta Hiperlipídica , Intolerância à Glucose/prevenção & controle , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Obesidade/etiologia , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Ganho de Peso/efeitos dos fármacos
16.
Mol Metab ; 25: 35-49, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31060926

RESUMO

OBJECTIVE: Brown adipose tissue (BAT) is important for thermoregulation in many mammals. Uncoupling protein 1 (UCP1) is the critical regulator of thermogenesis in BAT. Here we aimed to investigate the deacetylation control of BAT and to investigate a possible functional connection between UCP1 and sirtuin 3 (SIRT3), the master mitochondrial lysine deacetylase. METHODS: We carried out physiological, molecular, and proteomic analyses of BAT from wild-type and Sirt3KO mice when BAT is activated. Mice were either cold exposed for 2 days or were injected with the ß3-adrenergic agonist, CL316,243 (1 mg/kg; i.p.). Mutagenesis studies were conducted in a cellular model to assess the impact of acetylation lysine sites on UCP1 function. Cardiac punctures were collected for proteomic analysis of blood acylcarnitines. Isolated mitochondria were used for functional analysis of OXPHOS proteins. RESULTS: Our findings showed that SIRT3 absence in mice resulted in impaired BAT lipid use, whole body thermoregulation, and respiration in BAT mitochondria, without affecting UCP1 expression. Acetylome profiling of BAT mitochondria revealed that SIRT3 regulates acetylation status of many BAT mitochondrial proteins including UCP1 and crucial upstream proteins. Mutagenesis work in cells suggested that UCP1 activity was independent of direct SIRT3-regulated lysine acetylation. However, SIRT3 impacted BAT mitochondrial proteins activities of acylcarnitine metabolism and specific electron transport chain complexes, CI and CII. CONCLUSIONS: Our data highlight that SIRT3 likely controls BAT thermogenesis indirectly by targeting pathways upstream of UCP1.


Assuntos
Tecido Adiposo Marrom/metabolismo , Sirtuína 3/metabolismo , Proteína Desacopladora 1/metabolismo , 3-Hidroxiacil-CoA Desidrogenases , Acetil-CoA C-Aciltransferase , Acetilação , Tecido Adiposo Marrom/patologia , Antagonistas de Receptores Adrenérgicos beta 3/efeitos adversos , Animais , Composição Corporal , Regulação da Temperatura Corporal , Isomerases de Ligação Dupla Carbono-Carbono , Carnitina/análogos & derivados , Carnitina/farmacologia , Enoil-CoA Hidratase , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Modelos Animais , Mutagênese , Fosforilação Oxidativa , Proteômica , Racemases e Epimerases , Sirtuína 3/genética , Termogênese/fisiologia
17.
Mol Metab ; 25: 154-158, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31105057

RESUMO

OBJECTIVES: The browning of white adipose tissue (WAT) into beige has been proposed as a strategy to enhance energy expenditure to combat the growing epidemic of obesity. Research into browning strategies are hampered by the lack of sensitive, translatable, imaging tools capable of detecting beige fat mass non-invasively. [18F]FDG is able to detect activated beige fat but provides little information on unstimulated beige fat mass. We have assessed the use of [18F]FEPPA, a tracer for the TSPO-18KDa found on the outer mitochondrial membrane, as an alternative imaging agent capable of detecting unstimulated brown fat (BAT) and beige fat. METHODS: Female Balb/c mice (n = 5) were treated for 7 days with the ß3 adrenergic agonist CL-316,243 to induce the browning of inguinal WAT (beige fat). Animals were imaged longitudinally with [18F]FDG and [18F]FEPPA and uptake in interscapular BAT and inguinal WAT assessed. The browning of inguinal WAT was confirmed using H&E and immunohistochemical detection of UCP-1 and TSPO. RESULTS: Repeated dosing with ß3-adrenergic agonist CL-316,243 caused a significant increase in [18F]FDG uptake in both interscapular BAT and inguinal WAT associated with the increased metabolic activity of brown and beige adipocytes respectively. [18F]FEPPA uptake was likewise increased in inguinal WAT but showed no increase in BAT uptake due to stimulation over the same time course. Furthermore, inguinal WAT uptake was unaffected by pharmacological blockade, indicating that [18F]FEPPA uptake is associated with the expression of mitochondria in BAT and beige adipocytes and independent of activation. CONCLUSION: These data show that [18F]FEPPA can detect BAT and newly formed beige fat under non-stimulated, thermoneutral conditions and that uptake after stimulation is linked to mitochondrial expression as opposed to activation.


Assuntos
Tecido Adiposo Marrom/diagnóstico por imagem , Tecido Adiposo Branco/diagnóstico por imagem , Tecido Adiposo Branco/metabolismo , Fluordesoxiglucose F18/metabolismo , Adipócitos Bege/efeitos dos fármacos , Adipócitos Bege/metabolismo , Tecido Adiposo Bege/diagnóstico por imagem , Tecido Adiposo Bege/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/patologia , Agonistas de Receptores Adrenérgicos beta 3/farmacologia , Animais , Dioxóis/farmacologia , Metabolismo Energético , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Obesidade/diagnóstico por imagem , Obesidade/metabolismo , Obesidade/patologia
18.
Mol Cell ; 74(4): 844-857.e7, 2019 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-31000437

RESUMO

Brown adipose tissue (BAT) is rich in mitochondria and plays important roles in energy expenditure, thermogenesis, and glucose homeostasis. We find that levels of mitochondrial protein succinylation and malonylation are high in BAT and subject to physiological and genetic regulation. BAT-specific deletion of Sirt5, a mitochondrial desuccinylase and demalonylase, results in dramatic increases in global protein succinylation and malonylation. Mass spectrometry-based quantification of succinylation reveals that Sirt5 regulates the key thermogenic protein in BAT, UCP1. Mutation of the two succinylated lysines in UCP1 to acyl-mimetic glutamine and glutamic acid significantly decreases its stability and activity. The reduced function of UCP1 and other proteins in Sirt5KO BAT results in impaired mitochondria respiration, defective mitophagy, and metabolic inflexibility. Thus, succinylation of UCP1 and other mitochondrial proteins plays an important role in BAT and in regulation of energy homeostasis.


Assuntos
Metabolismo Energético/genética , Mitocôndrias/metabolismo , Obesidade/genética , Sirtuínas/genética , Proteína Desacopladora 1/genética , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Animais , Regulação da Expressão Gênica , Glucose/metabolismo , Camundongos , Camundongos Knockout , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Obesidade/metabolismo , Obesidade/patologia , Proteômica/métodos , Ácido Succínico/metabolismo , Termogênese/genética , Proteína Desacopladora 1/metabolismo
19.
J Vet Med Sci ; 81(6): 799-807, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-30956272

RESUMO

Brown adipocytes, which exist in brown adipose tissue (BAT), are activated by adrenergic stimulation, depending on the activity of uncoupling protein 1 (UCP1). Beige adipocytes emerge from white adipose tissue (WAT) in response to chronic adrenergic stimulation. We investigated obesity-related changes in responses of both types of adipocytes to adrenergic stimulation in mice. Feeding of mice with high-fat diets (HFD: 45%-kcal fat) for 14 weeks resulted in significantly higher body and WAT weight compared to feeding with normal diets (ND: 10%-kcal fat). Injection with ß3-adrenergic receptor agonist CL316,243 (CL; 0.1 mg/kg, once a day) for one week elevated the mRNA and protein expression levels of UCP1 in BAT, irrespective of diet. In WAT, CL-induced UCP1 expression in ND mice; however, the responses to CL treatment were attenuated in HFD mice, indicating that CL-induced browning of WAT was impaired in obese mice. Flow cytometric analysis revealed a significant decrease in platelet-derived growth factor receptor (PDGFR) α-expressing beige adipocyte progenitors in WAT of HFD mice compared with those of ND mice. Expression of PDGF-B, a PDGFRα ligand, increased in WAT following CL-injection in ND mice, but not in HFD mice. Treatment of mice with a PDGFR inhibitor significantly decreased CL-dependent UCP1 protein induction in WAT. Our study demonstrates that ß3-adrenergic stimulation-dependent beige adipocyte induction in WAT is impaired by obesity in mice, potentially due to obesity-dependent reduction in the number of PDGFRα-expressing progenitors and decreased PDGF-B expression.


Assuntos
Adipócitos Bege/efeitos dos fármacos , Tecido Adiposo Branco/efeitos dos fármacos , Agonistas de Receptores Adrenérgicos beta 3/farmacologia , Dioxóis/farmacologia , Obesidade/patologia , Adipócitos Bege/patologia , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Animais , Dieta Hiperlipídica , Regulação da Expressão Gênica , Masculino , Camundongos Endogâmicos C57BL , Camundongos Obesos , Proteínas Proto-Oncogênicas c-sis/metabolismo , Proteína Desacopladora 1/metabolismo
20.
J Diabetes Investig ; 10(6): 1419-1429, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30927519

RESUMO

AIMS/INTRODUCTION: Fat-specific protein 27 (FSP27) α is the major isoform of FSP27 in white adipose tissue (WAT), and is essential for large unilocular lipid droplet (LD) formation in white adipocytes. In contrast, FSP27ß is abundantly expressed in brown adipose tissue (BAT), and plays an important role in small multilocular LD formation. In FSP27 KO mice in which FSP27α and ß are both depleted, WAT is characterized by multilocular LD formation, and by increased mitochondrial abundance and energy expenditure, whereas BAT conversely manifests large oligolocular LDs and reduced energy expenditure. MATERIALS AND METHODS: We investigated the effects of autophagy in WAT and BAT of wild type (WT) and FSP27 knockout (KO) mice. In addition, we examined the effects of FSP27α and FSP27ß to the induction of autophagy in COS cells. RESULTS: Food deprivation induced autophagy in BAT of WT mice, as well as in WAT of FSP27 KO mice, suggesting that enhanced autophagy is characteristic of adipocytes with small multilocular LDs. Pharmacological inhibition of autophagy attenuated the fasting-induced loss of LD area in adipocytes with small multilocular LDs (BAT of WT mice and WAT of FSP27 KO mice), without affecting that in adipocytes with large unilocular or oligolocular LDs (WAT of WT mice or in BAT of FSP27 KO mice). Overexpression of FSP27α inhibited autophagy induction by serum deprivation in COS cells, whereas that of FSP27ß had no such effect. CONCLUSIONS: The present results thus showed that FSP27α inhibits autophagy and might thereby contribute to the energy-storage function of WAT.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Autofagia , Gotículas Lipídicas/metabolismo , Mitocôndrias/metabolismo , Proteínas/fisiologia , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/patologia , Animais , Metabolismo Energético , Gotículas Lipídicas/patologia , Masculino , Camundongos , Camundongos Knockout , Mitocôndrias/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA