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1.
Int J Mol Sci ; 22(19)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34638731

RESUMO

In recent years, brown adipose tissue (BAT), which has a high heat-producing capacity, has been confirmed to exist even in adults, and it has become a focal point for the prevention and the improvement of obesity and lifestyle-related diseases. However, the influences of obesity and physical activity (PA) on the fluid factors secreted from BAT (brown adipokines) are not well understood. In this study, therefore, we focused on brown adipokines and investigated the effects of obesity and PA. The abnormal expressions of gene fluid factors such as galectin-3 (Lgals3) and Lgals3 binding protein (Lgals3bp), whose proteins are secreted from HB2 brown adipocytes, were observed in the interscapular BAT of obese mice fed a high-fat diet for 4 months. PA attenuated the abnormalities in the expressions of these genes. Furthermore, although the gene expressions of factors related to brown adipocyte differentiation such as peroxisome proliferator-activated receptor gamma coactivator 1-α were also down-regulated in the BAT of the obese mice, PA suppressed the down-regulation of these factors. On the other hand, lipogenesis was increased more in HB2 cells overexpressing Lgals3 compared with that in control cells, and the overexpression of Lgals3bp decreased the mitochondrial mass. These results indicate that PA attenuates the obesity-induced dysregulated expression of brown adipokines and suggests that Lgals3 and Lgals3bp are involved in brown adipocyte differentiation.


Assuntos
Adipócitos Marrons/metabolismo , Adipocinas/biossíntese , Tecido Adiposo Marrom/metabolismo , Galectina 3/biossíntese , Regulação da Expressão Gênica , Obesidade/metabolismo , Condicionamento Físico Animal , Animais , Diferenciação Celular , Camundongos
2.
FASEB J ; 35(11): e21966, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34624148

RESUMO

Adipose tissue is central to the regulation of energy balance. While white adipose tissue (WAT) is responsible for triglyceride storage, brown adipose tissue specializes in energy expenditure. Deterioration of brown adipocyte function contributes to the development of metabolic complications like obesity and diabetes. These disorders are also leading symptoms of the Bardet-Biedl syndrome (BBS), a hereditary disorder in humans which is caused by dysfunctions of the primary cilium and which therefore belongs to the group of ciliopathies. The cilium is a hair-like organelle involved in cellular signal transduction. The BBSome, a supercomplex of several Bbs gene products, localizes to the basal body of cilia and is thought to be involved in protein sorting to and from the ciliary membrane. The effects of a functional BBSome on energy metabolism and lipid mobilization in brown and white adipocytes were tested in whole-body Bbs4 knockout mice that were subjected to metabolic challenges. Chronic cold exposure reveals cold-intolerance of knockout mice but also ameliorates the markers of metabolic pathology detected in knockouts prior to cold. Hepatic triglyceride content is markedly reduced in knockout mice while circulating lipids are elevated, altogether suggesting that defective lipid metabolism in adipose tissue creates increased demand for systemic lipid mobilization to meet energetic demands of reduced body temperatures. These findings taken together suggest that Bbs4 is essential for the regulation of adipose tissue lipid metabolism, representing a potential target to treat metabolic disorders.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Metabolismo dos Lipídeos , Proteínas Associadas aos Microtúbulos/fisiologia , Tecido Adiposo Marrom/citologia , Tecido Adiposo Branco/citologia , Animais , Metabolismo Energético , Masculino , Células-Tronco Mesenquimais , Camundongos , Camundongos Endogâmicos C57BL , Termogênese
3.
FASEB J ; 35(11): e21965, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34669999

RESUMO

Obesity and metabolic disorders caused by energy surplus pose an increasing concern within the global population. Brown adipose tissue (BAT) dissipates energy through mitochondrial non-shivering thermogenesis, thus representing a powerful agent against obesity. Here we explore the novel role of a mitochondrial outer membrane protein, LETM1-domain containing 1 (LETMD1), in BAT. We generated a knockout (Letmd1KO ) mouse model and analyzed BAT morphology, function and gene expression under various physiological conditions. While the Letmd1KO mice are born normally and have normal morphology and body weight, they lose multilocular brown adipocytes completely and have diminished mitochondrial abundance, DNA copy number, cristae structure, and thermogenic gene expression in the intrascapular BAT, associated with elevated reactive oxidative stress. In consequence, the Letmd1KO mice fail to maintain body temperature in response to acute cold exposure without food and become hypothermic within 4 h. Although the cold-exposed Letmd1KO mice can maintain body temperature in the presence of food, they cannot upregulate expression of uncoupling protein 1 (UCP1) and convert white to beige adipocytes, nor can they respond to adrenergic stimulation. These results demonstrate that LETMD1 is essential for mitochondrial structure and function, and thermogenesis of brown adipocytes.


Assuntos
Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/metabolismo , Mitocôndrias/metabolismo , Proteínas Oncogênicas/fisiologia , Receptores de Superfície Celular/fisiologia , Termogênese , Adipócitos Marrons/citologia , Tecido Adiposo Marrom/citologia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/metabolismo
4.
Nutrients ; 13(10)2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34684625

RESUMO

We previously reported the potential anti-obesity effects of the water extract of Hydrangea serrata (Thunb.) Ser. leaves (WHS) in high-fat diet-induced obese mice. As an extension of our previous study, we investigated the anti-adipogenic and anti-obesity effects of WHS and its underlying molecular mechanisms in 3T3-L1 preadipocytes and genetically obese db/db mice. WHS attenuated the gene expression of adipogenic transcription factors, CCAAT/enhancer binding protein (C/EBP)α, peroxisome proliferator-activated receptor (PPAR)γ, and sterol regulatory element binding protein (SREBP)-1. Moreover, WHS inhibited the mitotic clonal expansion of preadipocytes by inducing G1 cell cycle arrest. Oral administration of WHS alleviated body weight gain and body fat accumulation in vivo. In addition, adipocyte hypertrophy and liver steatosis were ameliorated by WHS treatment. WHS reduced C/EBPα, PPARγ, and SREBP-1 expression and activated AMPKα phosphorylation in both white adipose tissue (WAT) and liver tissue. WHS also mildly upregulated the expression of thermogenic proteins, including uncoupling protein-1, PPARs, PPARγ coactivator-1α, and sirtuin-1, in brown adipose tissue (BAT). Furthermore, WHS altered the gut microbiota composition to resemble that of wild-type mice. Taken together, our findings suggest that WHS could alleviate adiposity by inhibiting adipogenesis in WAT and the liver and modulating the gut microbiota.


Assuntos
Fármacos Antiobesidade/farmacologia , Hydrangea/química , Obesidade/tratamento farmacológico , Extratos Vegetais/farmacologia , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Adiposidade/efeitos dos fármacos , Animais , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Dieta Hiperlipídica/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/genética , Obesidade/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Termogênese/efeitos dos fármacos , Ganho de Peso/efeitos dos fármacos
5.
Cells ; 10(9)2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34572017

RESUMO

The present study sought to identify gene networks that are hallmarks of the developing inguinal subcutaneous adipose tissue (iWAT) and the interscapular brown adipose tissue (BAT) in the mouse. RNA profiling revealed that the iWAT of postnatal (P) day 6 mice expressed thermogenic and lipid catabolism transcripts, along with the abundance of transcripts associated with the beige adipogenesis program. This was an unexpected finding, as thermogenic BAT was believed to be the only site of nonshivering thermogenesis in the young mouse. However, the transcriptional landscape of BAT in P6 mice suggests that it is still undergoing differentiation and maturation, and that the iWAT temporally adopts thermogenic and lipolytic potential. Moreover, P6 iWAT and adult (P56) BAT were similar in their expression of immune gene networks, but P6 iWAT was unique in the abundant expression of antimicrobial proteins and virus entry factors, including a possible receptor for SARS-CoV-2. In summary, postnatal iWAT development is associated with a metabolic shift from thermogenesis and lipolysis towards fat storage. However, transcripts of beige-inducing signal pathways including ß-adrenergic receptors and interleukin-4 signaling were underrepresented in young iWAT, suggesting that the signals for thermogenic fat differentiation may be different in early postnatal life and in adulthood.


Assuntos
Adipócitos Bege/metabolismo , Transcrição Genética , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Animais Recém-Nascidos , Biomarcadores/metabolismo , Ciclo Celular/genética , Regulação da Expressão Gênica no Desenvolvimento , Ontologia Genética , Redes Reguladoras de Genes , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Desenvolvimento Muscular/genética , Neuropeptídeos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais
6.
Nat Commun ; 12(1): 5362, 2021 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-34508100

RESUMO

Activation of brown fat thermogenesis increases energy expenditure and alleviates obesity. Sympathetic nervous system (SNS) is important in brown/beige adipocyte thermogenesis. Here we discover a fat-derived "adipokine" neurotrophic factor neurotrophin 3 (NT-3) and its receptor Tropomyosin receptor kinase C (TRKC) as key regulators of SNS growth and innervation in adipose tissue. NT-3 is highly expressed in brown/beige adipocytes, and potently stimulates sympathetic neuron neurite growth. NT-3/TRKC regulates a plethora of pathways in neuronal axonal growth and elongation. Adipose tissue sympathetic innervation is significantly increased in mice with adipocyte-specific NT-3 overexpression, but profoundly reduced in mice with TRKC haploinsufficiency (TRKC +/-). Increasing NT-3 via pharmacological or genetic approach promotes beige adipocyte development, enhances cold-induced thermogenesis and protects against diet-induced obesity (DIO); whereas TRKC + /- or SNS TRKC deficient mice are cold intolerant and prone to DIO. Thus, NT-3 is a fat-derived neurotrophic factor that regulates SNS innervation, energy metabolism and obesity.


Assuntos
Tecido Adiposo Marrom/inervação , Neurotrofina 3/metabolismo , Obesidade/patologia , Sistema Nervoso Simpático/fisiologia , Termogênese/fisiologia , Adipócitos Bege/metabolismo , Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Animais , Dieta Hiperlipídica , Modelos Animais de Doenças , Metabolismo Energético/fisiologia , Humanos , Injeções Intraperitoneais , Camundongos , Camundongos Transgênicos , Neurotrofina 3/administração & dosagem , Obesidade/etiologia , Receptor trkC/genética , Receptor trkC/metabolismo , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/metabolismo , Transdução de Sinais/fisiologia
7.
J Agric Food Chem ; 69(40): 11900-11911, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34581185

RESUMO

This study explored whether the antiobesity effect of theabrownin (TB) extracted from Fu brick tea (FBT) was associated with the activation of brown adipose tissue (BAT) or browning of the white adipose tissue (WAT) in mice fed a high-fat diet (HFD). Mice were divided into five groups, which received a normal diet, HFD, or HFD plus TB (200, 400, and 800 mg/kg), respectively. A 12-week administration of TB in a dose-dependent manner reduced the body weight and WAT weight and improved lipid and glucose disorders in the HFD-fed mice (p < 0.05). TB also promoted the expression of thermogenic and mitochondrial genes, whereas inflammation genes were reduced in interscapular BAT (iBAT), inguinal WAT (iWAT), and epididymis white adipose tissue (eWAT), accompanied by improvement in the intestinal homeostasis by improving SCFAs, especially butyric acid levels (p < 0.05), which was related to thermogenic and inflammatory factors of iBAT and iWAT. Mechanistically, TB was shown to efficiently promote thermogenesis by stimulating the AMPK-PGC1α pathway with an increase in uncoupling protein 1 (UCP1). Conclusively, these findings suggest that long-term consumption of TB can enhance BAT activity and WAT browning by activating the AMPK-PGC1α pathway and modulating SCFAs; meanwhile, SCFAs regulating TB improved inflammatory disorder in HFD-fed mice.


Assuntos
Dieta Hiperlipídica , Metabolismo Energético , Adipócitos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Catequina/análogos & derivados , Dieta Hiperlipídica/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/etiologia , Obesidade/genética , Chá/metabolismo , Termogênese/genética
8.
Nat Commun ; 12(1): 5249, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475397

RESUMO

The wake-active orexin system plays a central role in the dynamic regulation of glucose homeostasis. Here we show orexin receptor type 1 and 2 are predominantly expressed in dorsal raphe nucleus-dorsal and -ventral, respectively. Serotonergic neurons in ventral median raphe nucleus and raphe pallidus selectively express orexin receptor type 1. Inactivation of orexin receptor type 1 in serotonin transporter-expressing cells of mice reduced insulin sensitivity in diet-induced obesity, mainly by decreasing glucose utilization in brown adipose tissue and skeletal muscle. Selective inactivation of orexin receptor type 2 improved glucose tolerance and insulin sensitivity in obese mice, mainly through a decrease in hepatic gluconeogenesis. Optogenetic activation of orexin neurons in lateral hypothalamus or orexinergic fibers innervating raphe pallidus impaired or improved glucose tolerance, respectively. Collectively, the present study assigns orexin signaling in serotonergic neurons critical, yet differential orexin receptor type 1- and 2-dependent functions in the regulation of systemic glucose homeostasis.


Assuntos
Glucose/metabolismo , Obesidade/metabolismo , Receptores de Orexina/metabolismo , Neurônios Serotoninérgicos/metabolismo , Tecido Adiposo Marrom/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Homeostase , Região Hipotalâmica Lateral/citologia , Região Hipotalâmica Lateral/metabolismo , Resistência à Insulina , Fígado/metabolismo , Camundongos , Fibras Nervosas/metabolismo , Obesidade/etiologia , Receptores de Orexina/genética , Orexinas/metabolismo , Núcleos da Rafe/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Transdução de Sinais
9.
Int J Mol Sci ; 22(17)2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34502532

RESUMO

Brown adipose tissue (BAT) expresses uncoupling protein-1 (UCP1), which enables energy to be exerted towards needed thermogenesis. Beige adipocytes are precursor cells interspersed among white adipose tissue (WAT) that possess similar UCP1 activity and capacity for thermogenesis. The raccoon dog (Nyctereutes procyonoides) is a canid species that utilizes seasonal obesity to survive periods of food shortage in climate zones with cold winters. The potential to recruit a part of the abundant WAT storages as beige adipocytes for UCP1-dependent thermogenesis was investigated in vitro by treating raccoon dog adipocytes with different browning inducing factors. In vivo positron emission tomography/computed tomography (PET/CT) imaging with the glucose analog 18F-FDG showed that BAT was not detected in the adult raccoon dog during the winter season. In addition, UCP1 expression was not changed in response to chronic treatments with browning inducing factors in adipocyte cultures. Our results demonstrated that most likely the raccoon dog endures cold weather without the induction of BAT or recruitment of beige adipocytes for heat production. Its thick fur coat, insulating fat, and muscle shivering seem to provide the adequate heat needed for surviving the winter.


Assuntos
Adaptação Fisiológica/fisiologia , Tecido Adiposo Bege/metabolismo , Tecido Adiposo Marrom/metabolismo , Cães Guaxinins/metabolismo , Estações do Ano , Adipócitos Bege/metabolismo , Adipócitos Marrons/metabolismo , Tecido Adiposo Bege/diagnóstico por imagem , Tecido Adiposo Marrom/diagnóstico por imagem , Tecido Adiposo Branco/diagnóstico por imagem , Tecido Adiposo Branco/metabolismo , Animais , Células Cultivadas , Fluordesoxiglucose F18/metabolismo , Masculino , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Termogênese , Proteína Desacopladora 1/metabolismo
10.
Obes Res Clin Pract ; 15(5): 485-490, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34465552

RESUMO

BACKGROUND: Adipose tissues have essential roles on energy homeostasis and the development of metabolic syndrome and obesity, they have become critical targets for treating obesity and metabolic disorders. Baicalin is a flavonoid that derived from the root of Scutellaria baicalensis, and it has been reported to take part in the regulation of adipocyte function. All these highlighted the potential of baicalin in the regulation of fat accumulation and obesity. Yet the impact of baicalin on thermogenic function of adipocytes remains to be deciphered. OBJECTIVE: This study aims to explore the anti-obesity effects of baicalin. MATERIALS & METHODS: The level of mRNA was detected by qRT-PCR and the protein expression level was examined by western blot. H&E staining was used for the observation of the structure of adipose tissue. Serum triglyceride and insulin levels were detected by commercial test kits. RESULTS: Our data demonstrated that baicalin up-regulates the expression of UCP1 and PGC1a in a dose-dependent manner in vitro. Baicalin also increases ERK phosphorylation, and the increased expression of UCP1 and PGC1a in adipocytes could be inhibited by an ERK inhibitor, U0126. Moreover, dietary baicalin ameliorates high fat diet (HFD)-induced obesity without affecting food intake. In addition, dietary baicalin inhibits adipocyte hypertrophy and enhances thermogenic gene program in sWAT and intrascapular brown adipose tissue (iBAT) in vivo. DISCUSSION & CONCLUSION: Baicalin prevents HFD-induced obesity partially through promoting adipocyte thermogenesis. Baicalin may be a promising compound against human obesity and related metabolic diseases.


Assuntos
Tecido Adiposo Branco , Metabolismo Energético , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Flavonoides/metabolismo , Flavonoides/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/tratamento farmacológico , Obesidade/etiologia , Obesidade/metabolismo , Termogênese
11.
Int J Mol Sci ; 22(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34502170

RESUMO

(1) Background: Pleiotrophin preserves insulin sensitivity, regulates adipose tissue lipid turnover and plasticity, energy metabolism and thermogenesis. The aim of this study was to determine the role of pleiotrophin in hepatic lipid metabolism and in the metabolic crosstalk between the liver and brown and white adipose tissue (AT) in a high-fat diet-induced (HFD) obesity mice model. (2) Methods: We analyzed circulating variables, lipid metabolism (hepatic lipid content and mRNA expression), brown AT thermogenesis (UCP-1 expression) and periovarian AT browning (brown adipocyte markers mRNA and immunodetection) in Ptn-/- mice either fed with standard-chow diet or with HFD and in their corresponding Ptn+/+ counterparts. (3) Results: HFD-Ptn-/- mice are protected against the development of HFD-induced insulin resistance, had lower liver lipid content and lower expression of the key enzymes involved in triacylglycerides and fatty acid synthesis in liver. HFD-Ptn-/- mice showed higher UCP-1 expression in brown AT. Moreover, Ptn deletion increased the expression of specific markers of brown/beige adipocytes and was associated with the immunodetection of UCP-1 enriched multilocular adipocytes in periovarian AT. (4) Conclusions: Ptn deletion protects against the development of HFD-induced insulin resistance and liver steatosis, by increasing UCP-1 expression in brown AT and promoting periovarian AT browning.


Assuntos
Tecido Adiposo Marrom/metabolismo , Citocinas/deficiência , Dieta Hiperlipídica/efeitos adversos , Suscetibilidade a Doenças , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Biomarcadores , Proteínas de Transporte , Modelos Animais de Doenças , Metabolismo Energético , Fígado Gorduroso/patologia , Expressão Gênica , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Knockout , Tamanho do Órgão , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
12.
Nutrients ; 13(7)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34371916

RESUMO

White adipose tissue (WAT) is a dynamic endocrine organ that can play a significant role in thermoregulation. WAT has the capacity to adopt structural and functional characteristics of the more metabolically active brown adipose tissue (BAT) and contribute to non-shivering thermogenesis under specific stimuli. Non-shivering thermogenesis was previously thought to be uncoupling protein 1 (UCP1)-dependent however, recent evidence suggests that UCP1-independent mechanisms of thermogenesis exist. Namely, futile creatine cycling has been identified as a contributor to WAT thermogenesis. The purpose of this study was to examine the efficacy of creatine supplementation to alter mitochondrial markers as well as adipocyte size and multilocularity in inguinal (iWAT), gonadal (gWAT), and BAT. Thirty-two male and female Sprague-Dawley rats were treated with varying doses (0 g/L, 2.5 g/L, 5 g/L, and 10 g/L) of creatine monohydrate for 8 weeks. We demonstrate that mitochondrial markers respond in a sex and depot specific manner. In iWAT, female rats displayed significant increases in COXIV, PDH-E1alpha, and cytochrome C protein content. Male rats exhibited gWAT specific increases in COXIV and PDH-E1alpha protein content. This study supports creatine supplementation as a potential method of UCP1-independant thermogenesis and highlights the importance of taking a sex-specific approach when examining the efficacy of browning therapeutics in future research.


Assuntos
Tecido Adiposo Branco/efeitos dos fármacos , Regulação da Temperatura Corporal/efeitos dos fármacos , Creatina/farmacologia , Suplementos Nutricionais , Mitocôndrias/efeitos dos fármacos , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Citocromos c/metabolismo , Relação Dose-Resposta a Droga , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Masculino , Mitocôndrias/metabolismo , Piruvato Desidrogenase (Lipoamida) , Ratos Sprague-Dawley , Fatores Sexuais , Proteína Desacopladora 1/metabolismo
13.
Nat Commun ; 12(1): 4725, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34354051

RESUMO

Gut microbiota deficient mice demonstrate accelerated glucose clearance. However, which tissues are responsible for the upregulated glucose uptake remains unresolved, with different studies suggesting that browning of white adipose tissue, or modulated hepatic gluconeogenesis, may be related to enhanced glucose clearance when the gut microbiota is absent. Here, we investigate glucose uptake in 22 different tissues in 3 different mouse models. We find that gut microbiota depletion via treatment with antibiotic cocktails (ABX) promotes glucose uptake in brown adipose tissue (BAT) and cecum. Nevertheless, the adaptive thermogenesis and the expression of uncoupling protein 1 (UCP1) are dispensable for the increased glucose uptake and clearance. Deletion of Ucp1 expressing cells blunts the improvement of glucose clearance in ABX-treated mice. Our results indicate that BAT and cecum, but not white adipose tissue (WAT) or liver, contribute to the glucose uptake in the gut microbiota depleted mouse model and this response is dissociated from adaptive thermogenesis.


Assuntos
Tecido Adiposo Marrom/metabolismo , Microbioma Gastrointestinal/fisiologia , Glucose/metabolismo , Adipócitos Bege/metabolismo , Adipócitos Marrons/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Antibacterianos/administração & dosagem , Ceco/metabolismo , Dieta Hiperlipídica/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Vida Livre de Germes , Masculino , Camundongos , Camundongos Knockout , Obesidade/metabolismo , Obesidade/patologia , Termogênese/fisiologia , Proteína Desacopladora 1/deficiência , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
14.
Int J Mol Sci ; 22(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34445344

RESUMO

Thyroid hormones, including 3,5,3'-triiodothyronine (T3), cause a wide spectrum of genomic effects on cellular metabolism and bioenergetic regulation in various tissues. The non-genomic actions of T3 have been reported but are not yet completely understood. Acute T3 treatment significantly enhanced basal, maximal, ATP-linked, and proton-leak oxygen consumption rates (OCRs) of primary differentiated mouse brown adipocytes accompanied with increased protein abundances of uncoupling protein 1 (UCP1) and mitochondrial Ca2+ uniporter (MCU). T3 treatment depolarized the resting mitochondrial membrane potential (Ψm) but augmented oligomycin-induced hyperpolarization in brown adipocytes. Protein kinase B (AKT) and mammalian target of rapamycin (mTOR) were activated by T3, leading to the inhibition of autophagic degradation. Rapamycin, as an mTOR inhibitor, blocked T3-induced autophagic suppression and UCP1 upregulation. T3 increases intracellular Ca2+ concentration ([Ca2+]i) in brown adipocytes. Most of the T3 effects, including mTOR activation, UCP1 upregulation, and OCR increase, were abrogated by intracellular Ca2+ chelation with BAPTA-AM. Calmodulin inhibition with W7 or knockdown of MCU dampened T3-induced mitochondrial activation. Furthermore, edelfosine, a phospholipase C (PLC) inhibitor, prevented T3 from acting on [Ca2+]i, UCP1 abundance, Ψm, and OCR. We suggest that short-term exposure of T3 induces UCP1 upregulation and mitochondrial activation due to PLC-mediated [Ca2+]i elevation in brown adipocytes.


Assuntos
Tecido Adiposo Marrom/efeitos dos fármacos , Cálcio/metabolismo , Mitocôndrias/efeitos dos fármacos , Tri-Iodotironina/farmacologia , Tecido Adiposo Marrom/metabolismo , Animais , Cálcio/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/fisiologia , Células Cultivadas , Metabolismo Energético/efeitos dos fármacos , Feminino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Consumo de Oxigênio/efeitos dos fármacos
15.
FASEB J ; 35(9): e21868, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34449920

RESUMO

Brown adipose tissue (BAT) plays an important role on no shivering thermogenesis during cold exposure to maintain animal body temperature and energy homeostasis. However, knowledge of the cellular transition from white adipose tissue (WAT) to BAT is still limited. In this study, we provided a comprehensive metabolomics and transcriptional signatures of goat BAT and WAT. A total of 157 metabolites were significantly changed, including 81 upregulated and 76 downregulated metabolites. In addition, we identified the citric acid cycle, fatty acid elongation, and degradation pathways as coordinately activated in BAT. Interestingly, five unsaturated fatty acids (Eicosadienoic Acid, C20:2; γ-Linolenic acid, C20:3; Arachidonic Acid, C20:4; Adrenic acid, C22:4; Docosahexaenoic acid, C22:6), Succinate, L-carnitine, and L-palmitoyl-carnitine were found to be abundant in BAT. Furthermore, L-carnitine, an intermediate of fatty acid degradation, is required for goat brown adipocyte differentiation and thermogenesis through activating AMPK pathway. However, L-carnitine decreased lipid accumulation through inducing lipolysis and thermogenesis in white adipocytes. These results revealed that there are the significant alterations in transcriptomic and metabolomic profiles between goat WAT and BAT, which may contribute to better understanding the roles of metabolites in BAT thermogenesis process.


Assuntos
Tecido Adiposo Marrom/metabolismo , Cabras/metabolismo , Termogênese/fisiologia , Adipogenia/fisiologia , Tecido Adiposo Branco/metabolismo , Animais , Diferenciação Celular/fisiologia , Regulação para Baixo/fisiologia , Metabolismo Energético/fisiologia , Ácidos Graxos Insaturados/metabolismo , Homeostase/fisiologia , Lipólise/fisiologia , Metabolômica/métodos , RNA-Seq/métodos , Transdução de Sinais/fisiologia , Regulação para Cima/fisiologia
16.
Int J Biochem Cell Biol ; 138: 106053, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34371171

RESUMO

Increased browning of white adipocytes (beiging) is considered a promising therapeutic strategy to fight obesity and its associated metabolic complications. However, the molecular mechanism modulating brown and beige fat-mediated thermogenesis is not fully elucidated. Here, we identified the lymphocyte cytosolic protein 1 (LCP1) as a factor that obstructs fat browning in white adipocytes. LCP1 plays a vital role in non-hematopoietic malignancies, and is also a well-known tumor biomarker; however, evidence regarding its function in adipocytes remains to be elucidated. The current study explores the physiological role of LCP1 in cultured 3T3-L1 white adipocytes, by applying the loss-of-function study using siRNA. Induction of fat browning by LCP1 depletion was evidenced by evaluating the gene and protein expression levels of brown fat-associated markers through real-time qRT-PCR and immunoblot analysis, respectively. We observed that deficiency of LCP1 promotes mitochondrial biogenesis, and significantly enhances expressions of the core brown fat-specific genes (Cd137, Cidea, Cited1, Tbx1, and Tmem26) and proteins (PGC-1α, PRDM16, and UCP1). In addition, deficiency of LCP1 promotes lipid catabolism as well as suppresses adipogenesis and lipogenesis. Loss of LCP1 also ameliorates cellular stress by downregulating JNK and c-JUN in adipocytes, and stimulates apoptosis. A mechanistic study revealed that deficiency of LCP1 induces browning in white adipocytes, independently via ß3-AR and the ERK signaling pathway. The current data reveals a previously unknown mechanism of LCP1 in browning of white adipocytes, and highlights the potential of LCP1 as a pharmacotherapeutic target for treating obesity and other metabolic disorders.


Assuntos
Adipócitos Brancos/citologia , Tecido Adiposo Marrom/citologia , Proteínas dos Microfilamentos/deficiência , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Receptores Adrenérgicos beta 3/metabolismo , Estresse Fisiológico , Células 3T3-L1 , Adipócitos Brancos/metabolismo , Tecido Adiposo Marrom/metabolismo , Animais , Lipogênese , Lipólise , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/genética , Receptores Adrenérgicos beta 3/genética , Transdução de Sinais , Termogênese
17.
Int J Mol Sci ; 22(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361032

RESUMO

17,18-Epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP) are bioactive epoxides produced from n-3 polyunsaturated fatty acid eicosapentaenoic acid and docosahexaenoic acid, respectively. However, these epoxides are quickly metabolized into less active diols by soluble epoxide hydrolase (sEH). We have previously demonstrated that an sEH inhibitor, t-TUCB, decreased serum triglycerides (TG) and increased lipid metabolic protein expression in the brown adipose tissue (BAT) of diet-induced obese mice. This study investigates the preventive effects of t-TUCB (T) alone or combined with 19,20-EDP (T + EDP) or 17,18-EEQ (T + EEQ) on BAT activation in the development of diet-induced obesity and metabolic disorders via osmotic minipump delivery in mice. Both T + EDP and T + EEQ groups showed significant improvement in fasting glucose, serum triglycerides, and higher core body temperature, whereas heat production was only significantly increased in the T + EEQ group. Moreover, both the T + EDP and T + EEQ groups showed less lipid accumulation in the BAT. Although UCP1 expression was not changed, PGC1α expression was increased in all three treated groups. In contrast, the expression of CPT1A and CPT1B, which are responsible for the rate-limiting step for fatty acid oxidation, was only increased in the T + EDP and T + EEQ groups. Interestingly, as a fatty acid transporter, CD36 expression was only increased in the T + EEQ group. Furthermore, both the T + EDP and T + EEQ groups showed decreased inflammatory NFκB signaling in the BAT. Our results suggest that 17,18-EEQ or 19,20-EDP combined with t-TUCB may prevent high-fat diet-induced metabolic disorders, in part through increased thermogenesis, upregulating lipid metabolic protein expression, and decreasing inflammation in the BAT.


Assuntos
Fármacos Antiobesidade/uso terapêutico , Ácidos Araquidônicos/uso terapêutico , Benzoatos/uso terapêutico , Obesidade/tratamento farmacológico , Compostos de Fenilureia/uso terapêutico , Adipogenia , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Animais , Fármacos Antiobesidade/administração & dosagem , Fármacos Antiobesidade/farmacologia , Ácidos Araquidônicos/administração & dosagem , Ácidos Araquidônicos/farmacologia , Benzoatos/administração & dosagem , Benzoatos/farmacologia , Glicemia/metabolismo , Carnitina O-Palmitoiltransferase/metabolismo , Dieta Hiperlipídica , Epóxido Hidrolases/antagonistas & inibidores , Ácidos Graxos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Compostos de Fenilureia/administração & dosagem , Compostos de Fenilureia/farmacologia
18.
Am J Physiol Endocrinol Metab ; 321(3): E433-E442, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34370596

RESUMO

Sepsis is a dysregulated systemic response to infection and can lead to organ damage and death. Obesity is a significant problem worldwide and affects outcomes from sepsis. Our laboratory demonstrated that white adipose tissue (WAT) undergoes browning during sepsis, a process whereby WAT adopts a brown adipose tissue phenotype. However, this browning process was not observed in obese mice during sepsis. White adipose tissue browning is detrimental in patients with burn injury and cancer. We hypothesize that norepinephrine (NE) induces WAT browning in nonobese mice but not in obese mice similarly to sepsis-induced WAT browning. Six-week-old C57BL/6 male mice were randomized to a high-fat diet or normal diet. After 6-7 wk of feeding, polymicrobial sepsis was induced by cecal ligation and puncture (CLP). Norepinephrine was administered intraperitoneally via osmotic minipumps for 18 h or 72 h (no CLP) at which time tissue and plasma were harvested. Controls were mice that underwent CLP (no NE) with 18-h harvest. A separate group of mice underwent pretreatment with NE or vehicle infusion for 72 h, CLP was performed, and at 18 h had tissue and plasma harvested. Sepsis resulted in significant weight loss in both nonobese and obese mice. NE treatment alone caused weight loss in obese mice. Septic nonobese mice had higher uncoupling protein-1 (UCP1) expression compared with control and obese septic mice. NE treatment increased UCP1 expression in nonobese, but not obese mice. NE-treated obese septic mice had lower lung myeloperoxidase (MPO) activity, alanine aminotransferase (ALT), aspartate aminotransferase (AST), TNFα, and IL-6 levels compared with NE-treated nonobese septic mice. Obesity protects mice from septic-induced and NE-induced WAT browning.NEW & NOTEWORTHY White adipose tissue browning is detrimental in patients with burn injury and cancer. WAT browning occurs in nonobese mice and can be induced by ß receptor norepinephrine infusion, but obese mice are resistant to sepsis-induced and norepinephrine-induced WAT browning. We propose that the lack of WAT browning and unchanged inflammatory cytokine response may contribute to the protection of obese mice from sepsis.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Norepinefrina/administração & dosagem , Obesidade/metabolismo , Sepse/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Branco/diagnóstico por imagem , Animais , Dieta Hiperlipídica , Masculino , Camundongos Endogâmicos C57BL , Obesidade/complicações , Sepse/complicações
19.
Eur J Endocrinol ; 185(4): 553-563, 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34342595

RESUMO

Objective: Brown adipose tissue (BAT) controls metabolic rate through thermogenesis. As its regulatory factors during the transition from hyperthyroidism to euthyroidism are not well established, our study investigated the relationships between supraclavicular brown adipose tissue (sBAT) activity and physiological/metabolic changes with changes in thyroid status. Design: Participants with newly diagnosed Graves' disease were recruited. A thionamide antithyroid drug (ATD) such as carbimazole (CMZ) or thiamazole (TMZ) was prescribed in every case. All underwent energy expenditure (EE) measurement and supraclavicular infrared thermography (IRT) within a chamber calorimeter, as well as 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography/magnetic resonance (PET/MR) imaging scanning, with clinical and biochemical parameters measured during hyperthyroidism and repeated in early euthyroidism. PET sBAT mean/maximum standardized uptake value (SUV mean/max), MR supraclavicular fat fraction (sFF) and mean temperature (Tscv) quantified sBAT activity. Results: Twenty-one (16 female/5 male) participants aged 39.5 ± 2.5 years completed the study. The average duration to attain euthyroidism was 28.6 ± 2.3 weeks. Eight participants were BAT-positive while 13 were BAT-negative. sFF increased with euthyroidism (72.3 ± 1.4% to 76.8 ± 1.4%; P < 0.01), but no changes were observed in PET SUV mean and Tscv. Significant changes in serum-free triiodothyronine (FT3) levels were related to BAT status (interaction P value = 0.04). FT3 concentration at hyperthyroid state was positively associated with sBAT PET SUV mean (r = 0.58, P = 0.01) and resting metabolic rate (RMR) (P < 0.01). Conclusion: Hyperthyroidism does not consistently lead to a detectable increase in BAT activity. FT3 reduction during the transition to euthyroidism correlated with BAT activity.


Assuntos
Tecido Adiposo Marrom/metabolismo , Hipertireoidismo/metabolismo , Hipertireoidismo/reabilitação , Tecido Adiposo Marrom/diagnóstico por imagem , Tecido Adiposo Marrom/efeitos dos fármacos , Adulto , Idoso , Antitireóideos/farmacologia , Antitireóideos/uso terapêutico , Composição Corporal/efeitos dos fármacos , Composição Corporal/fisiologia , Carbimazol/uso terapêutico , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Feminino , Fluordesoxiglucose F18 , Doença de Graves/tratamento farmacológico , Doença de Graves/metabolismo , Doença de Graves/reabilitação , Humanos , Hipertireoidismo/diagnóstico , Hipertireoidismo/tratamento farmacológico , Imageamento por Ressonância Magnética , Masculino , Metimazol/uso terapêutico , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Indução de Remissão , Singapura , Termogênese/efeitos dos fármacos , Termogênese/fisiologia , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo , Glândula Tireoide/fisiologia , Adulto Jovem
20.
Redox Biol ; 46: 102087, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34411987

RESUMO

Beige adipocyte mitochondria contribute to thermogenesis by uncoupling and by ATP-consuming futile cycles. Since uncoupling may inhibit ATP synthesis, it is expected that expenditure through ATP synthesis is segregated to a disparate population of mitochondria. Recent studies in mouse brown adipocytes identified peridroplet mitochondria (PDM) as having greater ATP synthesis and pyruvate oxidation capacities, while cytoplasmic mitochondria have increased fatty acid oxidation and uncoupling capacities. However, the occurrence of PDM in humans and the processes that result in their expansion have not been elucidated. Here, we describe a novel high-throughput assay to quantify PDM that is successfully applied to white adipose tissue from mice and humans. Using this approach, we found that PDM content varies between white and brown fat in both species. We used adipose tissue from pheochromocytoma (Pheo) patients as a model of white adipose tissue browning, which is characterized by an increase in the capacity for energy expenditure. In contrast with control subjects, PDM content was robustly increased in the periadrenal fat of Pheo patients. Remarkably, bioenergetic changes associated with browning were primarily localized to PDM compared to cytoplasmic mitochondria (CM). PDM isolated from periadrenal fat of Pheo patients had increased ATP-linked respiration, Complex IV content and activity, and maximal respiratory capacity. We found similar changes in a mouse model of re-browning where PDM content in whitened brown adipose tissue was increased upon re-browning induced by decreased housing temperature. Taken together, this study demonstrates the existence of PDM as a separate functional entity in humans and that browning in both mice and humans is associated with a robust expansion of peri-droplet mitochondria characterized by increased ATP synthesis linked respiration.


Assuntos
Tecido Adiposo Marrom , Termogênese , Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Metabolismo Energético , Humanos , Camundongos , Mitocôndrias/metabolismo
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