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1.
Nat Commun ; 12(1): 5255, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489438

RESUMO

Monocytes are part of the mononuclear phagocytic system. Monocytes play a central role during inflammatory conditions and a better understanding of their dynamics might open therapeutic opportunities. In the present study, we focused on the characterization and impact of monocytes on brown adipose tissue (BAT) functions during tissue remodeling. Single-cell RNA sequencing analysis of BAT immune cells uncovered a large diversity in monocyte and macrophage populations. Fate-mapping experiments demonstrated that the BAT macrophage pool requires constant replenishment from monocytes. Using a genetic model of BAT expansion, we found that brown fat monocyte numbers were selectively increased in this scenario. This observation was confirmed using a CCR2-binding radiotracer and positron emission tomography. Importantly, in line with their tissue recruitment, blood monocyte counts were decreased while bone marrow hematopoiesis was not affected. Monocyte depletion prevented brown adipose tissue expansion and altered its architecture. Podoplanin engagement is strictly required for BAT expansion. Together, these data redefine the diversity of immune cells in the BAT and emphasize the role of monocyte recruitment for tissue remodeling.


Assuntos
Tecido Adiposo Marrom/citologia , Monócitos/fisiologia , Adiponectina/genética , Tecido Adiposo Marrom/fisiologia , Animais , Diferenciação Celular/genética , Contagem de Leucócitos , Macrófagos/citologia , Macrófagos/fisiologia , Glicoproteínas de Membrana/metabolismo , Camundongos Transgênicos , Monócitos/citologia , Tomografia por Emissão de Pósitrons , Receptores CCR2/genética , Receptores CCR2/metabolismo
2.
Int J Mol Sci ; 22(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34502211

RESUMO

Obesity is a condition characterized by uncontrolled expansion of adipose tissue mass resulting in pathological weight gain. Histone deacetylases (HDACs) have emerged as crucial players in epigenetic regulation of adipocyte metabolism. Previously, we demonstrated that selective inhibition of class I HDACs improves white adipocyte functionality and promotes the browning phenotype of murine mesenchymal stem cells (MSCs) C3H/10T1/2 differentiated to adipocytes. These effects were also observed in db/db and diet induced obesity mouse models and in mice with adipose-selective inactivation of HDAC3, a member of class I HDACs. The molecular basis of class I HDACs action in adipose tissue is not deeply characterized and it is not known whether the effects of their inhibition are exerted on adipocyte precursors or mature adipocytes. Therefore, the aim of the present work was to explore the molecular mechanism of class I HDAC action in adipocytes by evaluating the effects of HDAC3-specific silencing at different stages of differentiation. HDAC3 was silenced in C3H/10T1/2 MSCs at different stages of differentiation to adipocytes. shRNA targeting HDAC3 was used to generate the knock-down model. Proper HDAC3 silencing was assessed by measuring both mRNA and protein levels of mouse HDAC3 via qPCR and western blot, respectively. Mitochondrial DNA content and gene expression were quantified via qPCR. HDAC3 silencing at the beginning of differentiation enhanced adipocyte functionality by amplifying the expression of genes regulating differentiation, oxidative metabolism, browning and mitochondrial activity, starting from 72 h after induction of differentiation and silencing. Insulin signaling was enhanced as demonstrated by increased AKT phosphorylation following HDAC3 silencing. Mitochondrial content/density did not change, while the increased expression of the transcriptional co-activator Ppargc1b suggests the observed phenotype was related to enhanced mitochondrial activity, which was confirmed by increased maximal respiration and proton leak linked to reduced coupling efficiency. Moreover, the expression of pro-inflammatory markers increased with HDAC3 early silencing. To the contrary, no differences in terms of gene expression were found when HDAC3 silencing occurred in terminally differentiated adipocyte. Our data demonstrated that early epigenetic events mediated by class I HDAC inhibition/silencing are crucial to commit adipocyte precursors towards the above-mentioned metabolic phenotype. Moreover, our data suggest that these effects are exerted on adipocyte precursors.


Assuntos
Tecido Adiposo Marrom/fisiologia , Tecido Adiposo Branco/fisiologia , Diferenciação Celular , Regulação da Expressão Gênica , Histona Desacetilases/metabolismo , Mitocôndrias/metabolismo , Fenótipo , Tecido Adiposo Marrom/citologia , Tecido Adiposo Branco/citologia , Animais , Histona Desacetilases/genética , Camundongos , Camundongos Endogâmicos C3H
3.
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
4.
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
5.
Artigo em Inglês | MEDLINE | ID: mdl-33933649

RESUMO

Disruption of circadian (~24 h) rhythms is associated with an increased risk of cardiometabolic diseases. Therefore, unravelling how circadian rhythms are regulated in different metabolic tissues has become a prominent research focus. Of particular interest is brown adipose tissue (BAT), which combusts triglyceride-derived fatty acids and glucose into heat and displays a circannual and diurnal rhythm in its thermogenic activity. In this review, the genetic, neuronal and endocrine generation of these rhythms in BAT is discussed. In addition, the potential risks of disruption or attenuation of these rhythms in BAT, and possible factors influencing these rhythms, are addressed.


Assuntos
Tecido Adiposo Marrom/citologia , Ritmo Circadiano , Animais , Humanos
6.
FEBS J ; 288(12): 3647-3662, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34028971

RESUMO

Brown adipose tissue (BAT) is well known to burn calories through uncoupled respiration, producing heat to maintain body temperature. This 'calorie wasting' feature makes BAT a special tissue, which can function as an 'energy sink' in mammals. While a combination of high energy intake and low energy expenditure is the leading cause of overweight and obesity in modern society, activating a safe 'energy sink' has been proposed as a promising obesity treatment strategy. Metabolically, lipids and glucose have been viewed as the major energy substrates in BAT, while succinate, lactate, branched-chain amino acids, and other metabolites can also serve as energy substrates for thermogenesis. Since the cataplerotic and anaplerotic reactions of these metabolites interconnect with each other, BAT relies on its dynamic, flexible, and complex metabolism to support its special function. In this review, we summarize how BAT orchestrates the metabolic utilization of various nutrients to support thermogenesis and contributes to whole-body metabolic homeostasis.


Assuntos
Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/metabolismo , Metabolismo Energético/genética , Metabolismo dos Lipídeos/genética , Obesidade/genética , Termogênese/genética , Adipócitos Marrons/citologia , Tecido Adiposo Marrom/citologia , Aminoácidos de Cadeia Ramificada/metabolismo , Animais , Fluordesoxiglucose F18/administração & dosagem , Glucose/metabolismo , Homeostase/genética , Humanos , Ácido Láctico/metabolismo , Obesidade/diagnóstico por imagem , Obesidade/metabolismo , Obesidade/patologia , Tomografia por Emissão de Pósitrons , Ácido Succínico/metabolismo
7.
Cryo Letters ; 42(2): 96-105, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33970986

RESUMO

BACKGROUND: Local fat accumulation is a health risk and this has raised interest in the development of aesthetic treatments, such as cryo-radiofrequency (CRF). OBJECTIVE: To evaluate the consequences of CRF in adipose tissue remodeling in a model system. MATERIALS AND METHODS: Lean and high-fat diet-induced obese mice were assessed 7 days after one CRF application; and lean mice were assessed 0, 3, 6 and 12 h after one application of CRF. Assessments included histology, DNA degradation, gene expression, ELISA of cytokines, serum analysis and neutrophil presence. RESULTS: Unchanged fat mass was found 7 days after CRF in obese and lean mice. However, lean mice showed smaller adipocyte size with areas resembling a browning process. TNF levels, apoptotic cells, and UCP-1 expression increased 7 days after CRF in inguinal adipose tissue of lean mice. Although no differences were found in fat mass, adipocyte size decreased just after CRF and this changed was maintained until 12 h, with cells resembling beige adipocytes. CONCLUSION: We suggest that CRF therapy is capable of inducing thermogenic adipocytes in lean mice.


Assuntos
Tecido Adiposo Marrom , Tecido Adiposo Branco , Crioterapia , Obesidade/terapia , Terapia por Radiofrequência , Adipócitos , Tecido Adiposo Marrom/citologia , Tecido Adiposo Branco/citologia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Termogênese
8.
Nat Commun ; 12(1): 2911, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006859

RESUMO

The impact of immune mediators on weight homeostasis remains underdefined. Interrogation of resistance to diet-induced obesity in mice lacking a negative regulator of Toll-like receptor signaling serendipitously uncovered a role for B cell activating factor (BAFF). Here we show that overexpression of BAFF in multiple mouse models associates with protection from weight gain, approximating a log-linear dose response relation to BAFF concentrations. Gene expression analysis of BAFF-stimulated subcutaneous white adipocytes unveils upregulation of lipid metabolism pathways, with BAFF inducing white adipose tissue (WAT) lipolysis. Brown adipose tissue (BAT) from BAFF-overexpressing mice exhibits increased Ucp1 expression and BAFF promotes brown adipocyte respiration and in vivo energy expenditure. A proliferation-inducing ligand (APRIL), a BAFF homolog, similarly modulates WAT and BAT lipid handling. Genetic deletion of both BAFF and APRIL augments diet-induced obesity. Lastly, BAFF/APRIL effects are conserved in human adipocytes and higher BAFF/APRIL levels correlate with greater BMI decrease after bariatric surgery. Together, the BAFF/APRIL axis is a multifaceted immune regulator of weight gain and adipose tissue function.


Assuntos
Fator Ativador de Células B/genética , Obesidade/genética , Transdução de Sinais/genética , Membro 13 da Superfamília de Ligantes de Fatores de Necrose Tumoral/genética , Ganho de Peso/genética , Adipócitos/citologia , Adipócitos/metabolismo , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/citologia , Tecido Adiposo Branco/metabolismo , Animais , Fator Ativador de Células B/metabolismo , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Perfilação da Expressão Gênica/métodos , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Obesidade/etiologia , Obesidade/metabolismo , Membro 13 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo
9.
Nat Commun ; 12(1): 2622, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976180

RESUMO

Obesity is caused by an imbalance between food intake and energy expenditure (EE). Here we identify a conserved pathway that links signalling through peripheral Y1 receptors (Y1R) to the control of EE. Selective antagonism of peripheral Y1R, via the non-brain penetrable antagonist BIBO3304, leads to a significant reduction in body weight gain due to enhanced EE thereby reducing fat mass. Specifically thermogenesis in brown adipose tissue (BAT) due to elevated UCP1 is enhanced accompanied by extensive browning of white adipose tissue both in mice and humans. Importantly, selective ablation of Y1R from adipocytes protects against diet-induced obesity. Furthermore, peripheral specific Y1R antagonism also improves glucose homeostasis mainly driven by dynamic changes in Akt activity in BAT. Together, these data suggest that selective peripheral only Y1R antagonism via BIBO3304, or a functional analogue, could be developed as a safer and more effective treatment option to mitigate diet-induced obesity.


Assuntos
Arginina/análogos & derivados , Obesidade/prevenção & controle , Receptores de Neuropeptídeo Y/antagonistas & inibidores , Termogênese/efeitos dos fármacos , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Adulto , Animais , Arginina/farmacologia , Arginina/uso terapêutico , Biópsia , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Metabolismo Energético/efeitos dos fármacos , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Obesidade/etiologia , Obesidade/metabolismo , Cultura Primária de Células , Receptores de Neuropeptídeo Y/metabolismo
10.
Nat Commun ; 12(1): 2876, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34001883

RESUMO

Activation of non-shivering thermogenesis is considered a promising approach to lower body weight in obesity. p62 deficiency in adipocytes reduces systemic energy expenditure but its role in sustaining mitochondrial function and thermogenesis remains unresolved. NBR1 shares a remarkable structural similarity with p62 and can interact with p62 through their respective PB1 domains. However, the physiological relevance of NBR1 in metabolism, as compared to that of p62, was not clear. Here we show that whole-body and adipocyte-specific ablation of NBR1 reverts the obesity phenotype induced by p62 deficiency by restoring global energy expenditure and thermogenesis in brown adipose tissue. Impaired adrenergic-induced browning of p62-deficient adipocytes is rescued by NBR1 inactivation, unveiling a negative role of NBR1 in thermogenesis under conditions of p62 loss. We demonstrate that upon p62 inactivation, NBR1 represses the activity of PPARγ, establishing an unexplored p62/NBR1-mediated paradigm in adipocyte thermogenesis that is critical for the control of obesity.


Assuntos
Adipócitos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , PPAR gama/metabolismo , Proteína Sequestossoma-1/deficiência , Termogênese , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Animais , Animais Recém-Nascidos , Núcleo Celular/metabolismo , Células Cultivadas , Metabolismo Energético/genética , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , PPAR gama/genética , Ligação Proteica , Receptor X Retinoide alfa/genética , Receptor X Retinoide alfa/metabolismo , Proteína Sequestossoma-1/genética
11.
J Biol Chem ; 296: 100632, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33865855

RESUMO

Nonshivering thermogenesis is essential for mammals to maintain body temperature. According to the canonical view, temperature is sensed by cutaneous thermoreceptors and nerve impulses transmitted to the hypothalamus, which generates sympathetic signals to ß-adrenergic receptors in brown adipocytes. The energy for heat generation is primarily provided by the oxidation of fatty acids derived from triglyceride hydrolysis and cellular uptake. Fatty acids also activate the uncoupling protein, UCP1, which creates a proton leak that uncouples mitochondrial oxidative phosphorylation from ATP production, resulting in energy dissipation as heat. Recent evidence supports the idea that in response to mild cold, ß-adrenergic signals stimulate not only lipolysis and fatty acid oxidation, but also act through the mTORC2-Akt signaling module to stimulate de novo lipogenesis. This opposing anabolic effect is thought to maintain lipid fuel stores during increased catabolism. We show here, using brown fat-specific Gs-alpha knockout mice and cultured adipocytes that, unlike mild cold, severe cold directly cools brown fat and bypasses ß-adrenergic signaling to inhibit mTORC2. This cell-autonomous effect both inhibits lipogenesis and augments UCP1 expression to enhance thermogenesis. These findings suggest a novel mechanism for overriding ß-adrenergic-stimulated anabolic activities while augmenting catabolic activities to resolve the homeostatic crisis presented by severe cold.


Assuntos
Tecido Adiposo Marrom/metabolismo , Cromograninas/fisiologia , Temperatura Baixa , Subunidades alfa Gs de Proteínas de Ligação ao GTP/fisiologia , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Termogênese , Tecido Adiposo Marrom/citologia , Animais , Lipogênese , Masculino , Alvo Mecanístico do Complexo 2 de Rapamicina/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores Adrenérgicos beta/genética , Receptores Adrenérgicos beta/metabolismo , Transdução de Sinais , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
12.
Artigo em Inglês | MEDLINE | ID: mdl-33713833

RESUMO

Mitochondrial abundance and thermogenic capacity are two imperative components that distinguish brown, beige and white adipose tissues. Most importantly, the lipid composition is vital for maintaining the quantity, quality and function of mitochondria. Therefore, we employed quantitative lipidomics to probe the mitochondrial lipidome of adipose tissues. The mitochondrial lipidome reveals ß3-adrenergic stimulation and aging drastically altered the levels of phosphatidylcholine (PC)/phosphatidylethanolamine (PE) ratio and acyl chain desaturation. Precisely, PC36:2 and PE38:4 levels correlate with the increased brown and beige fat activity in young mice. While aging increased lysoPC species in white adipose tissue (WAT) mitochondria, CL-316,243 administration reduced lysoPC species and increased lyso-PE18:1 and 18:2 content during WAT browning. Also, non-thermogenic mitochondria accumulate sphingomyelin (SM), phosphatidylserine (PS), phosphatidic acid (PA) and ether-linked PC (ePC). Similarly, enrichment of phosphatidylglycerol (PG) and cardiolipin (CL) levels are associated with thermogenic mitochondria. Also, our in vitro experiment supports that blocking the de novo sphingolipid synthesis pathway by myriocin, SPT1 inhibitor increased the thermogenic capacity and oxygen consumption rate in mature adipocytes. Overall, our study suggests mitochondria of brown, beige and white adipose tissues own a unique pattern of lipid molecular species and their levels are altered by aging and CL-316,243 administration.


Assuntos
Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Branco/citologia , Adrenérgicos/farmacologia , Envelhecimento/metabolismo , Lipidômica , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Animais , Metabolismo Energético/efeitos dos fármacos , Camundongos , Consumo de Oxigênio/efeitos dos fármacos , Termogênese/efeitos dos fármacos
13.
Nat Commun ; 12(1): 1905, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33772024

RESUMO

Brown and beige adipose tissue are emerging as distinct endocrine organs. These tissues are functionally associated with skeletal muscle, adipose tissue metabolism and systemic energy expenditure, suggesting an interorgan signaling network. Using metabolomics, we identify 3-methyl-2-oxovaleric acid, 5-oxoproline, and ß-hydroxyisobutyric acid as small molecule metabokines synthesized in browning adipocytes and secreted via monocarboxylate transporters. 3-methyl-2-oxovaleric acid, 5-oxoproline and ß-hydroxyisobutyric acid induce a brown adipocyte-specific phenotype in white adipocytes and mitochondrial oxidative energy metabolism in skeletal myocytes both in vitro and in vivo. 3-methyl-2-oxovaleric acid and 5-oxoproline signal through cAMP-PKA-p38 MAPK and ß-hydroxyisobutyric acid via mTOR. In humans, plasma and adipose tissue 3-methyl-2-oxovaleric acid, 5-oxoproline and ß-hydroxyisobutyric acid concentrations correlate with markers of adipose browning and inversely associate with body mass index. These metabolites reduce adiposity, increase energy expenditure and improve glucose and insulin homeostasis in mouse models of obesity and diabetes. Our findings identify beige adipose-brown adipose-muscle physiological metabokine crosstalk.


Assuntos
Tecido Adiposo Bege/metabolismo , Tecido Adiposo Marrom/metabolismo , Metabolismo Energético/genética , Homeostase/genética , Transdução de Sinais/genética , Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Tecido Adiposo Bege/citologia , Tecido Adiposo Marrom/citologia , Animais , Linhagem Celular , Células Cultivadas , Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas , Perfilação da Expressão Gênica/métodos , Humanos , Masculino , Espectrometria de Massas , Metabolômica/métodos , Camundongos Endogâmicos C57BL
14.
J Vis Exp ; (169)2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33779621

RESUMO

Brown adipose tissue (BAT) is responsible for non-shivering thermogenesis in mammals, and brown adipocytes (BAs) are the functional units of BAT. BAs contain both multilocular lipid droplets and abundant mitochondria, and they express uncoupling protein 1 (UCP1). BAs are categorized into two sub-types based on their origin: embryo derived classical BAs (cBAs) and white adipocytes derived BAs. Due to their relatively low density, BAs cannot be isolated from BAT with traditional centrifugation method. In this study, a new method was developed to isolate BAs from mice for gene and protein expression analysis. In this protocol, interscapular BAT from adult mice was digested with Collagenase and Dispase solution, and the dissociated BAs were enriched with 6% iodixanol solution. Isolated BAs were then lysed with Trizol reagent for simultaneous isolation of RNA, DNA, and protein. After RNA isolation, the organic phase of the lysate was used for protein extraction. Our data showed that 6% iodixanol solution efficiently enriched BAs without interfering with follow-up gene and protein expression studies. Platelet-derived growth factor (PDGF) is a growth factor that regulates the growth and proliferation of mesenchymal cells. Compared to the brown adipose tissue, isolated BAs had significantly higher expression of Pdgfa. In summary, this new method provides a platform for studying the biology of brown adipocytes at a single cell-type level.


Assuntos
Adipócitos Marrons/citologia , Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/citologia , Regulação da Expressão Gênica , Proteínas/genética , Proteínas/metabolismo , Escápula/citologia , Tecido Adiposo Marrom/metabolismo , Animais , Separação Celular/métodos , Camundongos , Escápula/metabolismo
15.
Pharm Res ; 38(1): 9-14, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33433776

RESUMO

The presence of glycogen in the brown adipose tissue (BAT) has been described 60 years ago. However, the role of this energetic storage in brown adipocytes has been long time underestimated. We have recently shown that during brown adipocyte differentiation in the embryo, glycogen accumulates and is degraded by glycophagy, a dynamic essential for lipid droplets biogenesis. Recent studies have shown that the storage and degradation of triglycerides in BAT are not essential for the activation of BAT in response to cold exposure in adults, and that glycogen can compensate for their absence. In this review, we report the recent advances related to the importance of glycogen in brown adipocytes.


Assuntos
Tecido Adiposo Marrom/metabolismo , Glicogênio/metabolismo , Glicogenólise/fisiologia , Termogênese/fisiologia , Adipócitos/metabolismo , Tecido Adiposo Marrom/citologia , Animais , Metabolismo Energético/fisiologia , Humanos , Gotículas Lipídicas/metabolismo , Lipólise , Triglicerídeos/metabolismo
16.
Acta Biochim Biophys Sin (Shanghai) ; 53(1): 112-118, 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33219380

RESUMO

AMP-activated protein kinase (AMPK) is indispensable for the development and maintenance of brown adipose tissue (BAT), and its activity is inhibited due to obesity. The isocitrate dehydrogenase 2 (IDH2) is a mitochondrial enzyme responsible for the production of α-ketoglutarate, a key intermediate metabolite integrating multiple metabolic processes. We previously found that AMPKα1 ablation reduced cellular α-ketoglutarate concentration during brown adipocyte differentiation, but the effect of AMPKα1 on Idh2 expression remains undefined. In the present study, mouse C3H10T1/2 cells were transfected with Idh2-CRISPR/Cas9, and induced to brown adipogenesis. Our data suggested that brown adipogenesis was compromised due to IDH2 deficiency in vitro, which was accompanied by down-regulation of PR-domain containing 16. Importantly, the IDH2 content was reduced in brown stromal vascular cells (BSVs) separated from AMPKα1 knockout (KO) BAT, which was associated with lower contents of histone 2B (H2B) O-GlcNAcylation and monoubiquitination. Furthermore, both GlcNAcylated-H2B (S112) and ubiquityl-histone 2B (K120) contents in the Idh2 promoter were decreased in AMPKα1 KO BSVs. Meanwhile, ectopic O-linked N-acetylglucosamine transferase (OGT) expression was positively correlated with Idh2 expression, while OGT (T444A) mutation abolished the regulatory effect of AMPKα1 on Idh2. In vivo, reduced AMPKα1 activity and lower IDH2 abundance were observed in BAT of obese mice when compared with those in control mice. Taken together, our data demonstrated that IDH2 is necessary for brown adipogenesis and that AMPKα1 deficiency attenuates Idh2 expression, which might be by suppressing H2B O-GlcNAcylation modification.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Tecido Adiposo Marrom/metabolismo , Histonas/metabolismo , Isocitrato Desidrogenase/genética , Acilação , Adipogenia/fisiologia , Tecido Adiposo Marrom/citologia , Animais , Sistemas CRISPR-Cas , Linhagem Celular , Dieta Hiperlipídica , Feminino , Glucose/metabolismo , Isocitrato Desidrogenase/metabolismo , Células-Tronco Mesenquimais , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Regiões Promotoras Genéticas
17.
Artigo em Inglês | MEDLINE | ID: mdl-33010451

RESUMO

Different strategies to boost NAD+ levels are considered promising means to promote healthy aging and ameliorate dysfunctional metabolism. CD38 is a NAD+-dependent enzyme involved in the regulation of different cell functions. In the context of systemic energy metabolism, it has been demonstrated that brown adipocytes, the parenchymal cells of brown adipose tissue (BAT) as well as beige adipocytes that emerge in white adipose tissue (WAT) depots in response to catabolic conditions, are important to maintain metabolic homeostasis. In this study we aim to understand the functional relevance of CD38 for NAD+ and energy metabolism in BAT and WAT, also using a CD38-/- mouse model. During cold exposure, an increase in NAD+ levels occurred in BAT of wild type mice, together with a marked downregulation of CD38, as detected at the mRNA and protein level. CD38 downregulation was observed also in WAT of cold-exposed mice, where it was accompanied by a strong increase in NADP(H) levels. Accordingly, NAD kinase and glucose-6-phosphate dehydrogenase activities were enhanced in WAT (but not in BAT). Increased NAD+ levels were observed in BAT/WAT from CD38-/- compared with wild type mice, in line with CD38 being a major NAD+-consumer in AT. CD38-/- mice kept at 6 °C had higher levels of Ucp1 and Pgc-1α in BAT and WAT, and increased levels of phosphorylated hormone-sensitive lipase in BAT, compared with wild type mice. These results demonstrate that CD38, by modulating cellular NAD(P)+ levels, is involved in the regulation of thermogenic responses in cold-activated BAT and WAT.


Assuntos
ADP-Ribosil Ciclase 1/genética , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Glicoproteínas de Membrana/genética , NADP/metabolismo , NAD/metabolismo , RNA Mensageiro/genética , Termogênese/genética , ADP-Ribosil Ciclase 1/deficiência , Adipócitos Bege/citologia , Adipócitos Bege/metabolismo , Adipócitos Marrons/citologia , Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/citologia , Tecido Adiposo Branco/citologia , Animais , Temperatura Baixa , Metabolismo Energético/genética , Regulação da Expressão Gênica , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Homeostase/genética , Glicoproteínas de Membrana/deficiência , Camundongos , Camundongos Knockout , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Fosforilação , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , RNA Mensageiro/metabolismo , Transdução de Sinais , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
18.
Magn Reson Imaging ; 77: 1-6, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33309921

RESUMO

OBJECTIVE: The aim of this study was to measure brown adipose tissue (BAT) activity by targeted peptide (CKGGRAKDC-NH2)-coupled, polyethylene glycol (PEG)-coated ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles with magnetic resonance imaging (MRI). METHODS: The peptide was conjugated with PEG-coated USPIO to obtain targeted probes. Male C57BL/6 J mice were randomly divided into cold exposing and control group (n = 5 per group). T2*-weighted images were obtained pre- and post-contrast probes. Histological and gene expression analyses were carried out. RESULTS: T2* relaxation time of BAT in the cold exposing group decreased more significantly compared to the control group. The calculated R2* increased with the reduction of T2* value. The ΔR2* (26.68 s-1) of BAT in the cold exposing group was significantly higher (P < 0.05) than the control group. Iron particle sediments in BAT of the cold exposing group were revealed more than the control group with Prussian blue staining. The UCP1 expression level was up-regulated after cold activation. CONCLUSIONS: BAT activity could be measured in vivo by the targeted peptide-coupled, PEG-coated USPIOs with MRI.


Assuntos
Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/diagnóstico por imagem , Imageamento por Ressonância Magnética , Animais , Linhagem Celular Tumoral , Ferro/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Polietilenoglicóis/química
19.
Proc Natl Acad Sci U S A ; 117(50): 32029-32037, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33257580

RESUMO

Disease tolerance, the capacity of tissues to withstand damage caused by a stimulus without a decline in host fitness, varies across tissues, environmental conditions, and physiologic states. While disease tolerance is a known strategy of host defense, its role in noninfectious diseases has been understudied. Here, we provide evidence that a thermogenic fat-epithelial cell axis regulates intestinal disease tolerance during experimental colitis. We find that intestinal disease tolerance is a metabolically expensive trait, whose expression is restricted to thermoneutral mice and is not transferable by the microbiota. Instead, disease tolerance is dependent on the adrenergic state of thermogenic adipocytes, which indirectly regulate tolerogenic responses in intestinal epithelial cells. Our work has identified an unexpected mechanism that controls intestinal disease tolerance with implications for colitogenic diseases.


Assuntos
Tecido Adiposo Marrom/metabolismo , Colite/imunologia , Neoplasias do Colo/imunologia , Resistência à Doença , Infecções por Enterobacteriaceae/imunologia , Adipócitos/metabolismo , Tecido Adiposo Marrom/citologia , Animais , Azoximetano/administração & dosagem , Comunicação Celular , Citrobacter rodentium/patogenicidade , Colite/induzido quimicamente , Colite/microbiologia , Colite/patologia , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/patologia , Sulfato de Dextrana/toxicidade , Infecções por Enterobacteriaceae/induzido quimicamente , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/patologia , Células Epiteliais/metabolismo , Feminino , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Masculino , Camundongos , Neoplasias Experimentais/induzido quimicamente , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Termogênese/imunologia
20.
Front Endocrinol (Lausanne) ; 11: 565483, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193083

RESUMO

Obesity has become a worldwide epidemic, and obesity-related problems are becoming more severe in public health. Increasing brown adipose tissue (BAT) mass or/and activity in mice and humans has been demonstrated to help lose weight and improve whole-body metabolism. Studies on the conversion of white adipose tissue (WAT) to BAT under certain conditions have provided new possibilities for treating obesity and the related disorders. It has been established that long non-coding RNAs (lncRNAs) play an important role in the regulation of mouse adipocyte differentiation and thermogenic programs; however, the function and potential mechanism of lncRNA in the process of human white adipocyte browning remains unclear. In the present study, we identified a lncRNA called Forkhead Box C2 antisense RNA 1 (FOXC2-AS1), which was first identified in osteosarcoma, and it was highly expressed in human adipocytes but decreased during the white adipocyte differentiation program. FOXC2-AS1 expression was also induced by the thermogenic agent forskolin. Lentivirus-mediated overexpression of FOXC2-AS1 in human white adipocytes did not affect lipid drop accumulation, but significantly promoted the browning phenotype, as revealed by the increased respiratory capacity and the enhanced protein expression levels of brown adipocyte-specific markers. In contrast, inhibiting FOXC2-AS1 with small interfering RNA led to attenuated thermogenic capacity in human white adipocytes. RNA-sequencing analysis and western blot were used to identify a possible regulatory role of the autophagy signaling pathway in FOXC2-AS1 to mediate white-to-brown adipocyte conversion. The autophagy inhibitor 3-methyladenine restored the reduced UCP1 protein level and thermogenic capacity caused by inhibiting FOXC2-AS1. Overall, the present study characterized the potential role of FOXC2-AS1 and further identified a lncRNA-mediated mechanism for inducing browning of human white adipocytes and maintaining thermogenesis, further providing a potential strategy for treating obesity and related disorder.


Assuntos
Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Diferenciação Celular/fisiologia , Fatores de Transcrição Forkhead/biossíntese , Fatores de Transcrição Forkhead/genética , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/citologia , Tecido Adiposo Branco/metabolismo , Autofagia/fisiologia , Células Cultivadas , Fatores de Transcrição Forkhead/deficiência , Técnicas de Silenciamento de Genes , Humanos
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