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1.
Nat Commun ; 11(1): 575, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31996678

RESUMO

mTORC2 phosphorylates AKT in a hydrophobic motif site that is a biomarker of insulin sensitivity. In brown adipocytes, mTORC2 regulates glucose and lipid metabolism, however the mechanism has been unclear because downstream AKT signaling appears unaffected by mTORC2 loss. Here, by applying immunoblotting, targeted phosphoproteomics and metabolite profiling, we identify ATP-citrate lyase (ACLY) as a distinctly mTORC2-sensitive AKT substrate in brown preadipocytes. mTORC2 appears dispensable for most other AKT actions examined, indicating a previously unappreciated selectivity in mTORC2-AKT signaling. Rescue experiments suggest brown preadipocytes require the mTORC2/AKT/ACLY pathway to induce PPAR-gamma and establish the epigenetic landscape during differentiation. Evidence in mature brown adipocytes also suggests mTORC2 acts through ACLY to increase carbohydrate response element binding protein (ChREBP) activity, histone acetylation, and gluco-lipogenic gene expression. Substrate utilization studies additionally implicate mTORC2 in promoting acetyl-CoA synthesis from acetate through acetyl-CoA synthetase 2 (ACSS2). These data suggest that a principal mTORC2 action is controlling nuclear-cytoplasmic acetyl-CoA synthesis.


Assuntos
ATP Citrato (pro-S)-Liase/metabolismo , Adipócitos Marrons/metabolismo , Lipogênese/fisiologia , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Acetato-CoA Ligase/metabolismo , Animais , Proteínas de Transporte , Epigênese Genética , Ácido Graxo Sintases , Edição de Genes , Expressão Gênica , Transportador de Glucose Tipo 4/genética , Transportador de Glucose Tipo 4/metabolismo , Células HEK293 , Histonas/metabolismo , Humanos , Lipogênese/genética , Camundongos , Camundongos Endogâmicos C57BL , PPAR gama/metabolismo , Fosforilação , Proteômica , Elementos de Resposta
2.
J Agric Food Chem ; 67(51): 14056-14065, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31789021

RESUMO

The main purpose of the present study was to investigate the browning effect of 6-gingerol (6G), one of the main functional compounds in the ethyl acetate extract of ginger (ginger ethyl acetate fraction, GEF), and its underlying mechanisms. In this study, we first discovered that GEF stimulated brown adipocyte differentiation by upregulating the expression levels of browning-specific transcription makers (UCP1, PRDM16, and PGC-1α), thereby reducing lipogenesis transcriptional regulator (C/EBPα) expression in 3T3-L1-differentiated adipocytes. Then, 6G (47.81 ± 0.62 mg/g) was identified as one of the main functional compounds in GEF using high-performance liquid chromatography. 6G promoted adipocyte browning, as evidenced by an increase in some brown/beige fat-specific genes (PGC-1α, Cidea, Prdm16, Cited1, SIRT1, Tmem26, and Ucp1) and proteins (UCP1, CEBP/ß, PGC-1α, and PRDM16) expression levels. Moreover, 6G greatly improved mitochondrial respiration and energy metabolism by upregulating the expression levels of some mitochondrial biogenesis markers (Tfam, Nrf1, SIRT1, and p-AMPK/AMPK) and increasing the uncoupled oxygen consumption rate of protons leaked in 3T3-L1 cells. Comparison of the experimental results obtained with an inhibitor (dorsomorphin) and an activator (5-aminoimidazole-4-carboxamide ribonucleotide) suggested that the 6G-associated regulation of the energy metabolism effect was mediated partly through the AMPK signaling pathway. This study provides new insight into the promotion of fat browning and regulation of lipid metabolism by 6G and suggests that 6G likely has potential therapeutic effects on obesity.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos Marrons/efeitos dos fármacos , Catecóis/farmacologia , Álcoois Graxos/farmacologia , Gengibre/química , Extratos Vegetais/farmacologia , Células 3T3-L1 , Proteínas Quinases Ativadas por AMP/genética , Adipócitos Marrons/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Camundongos , Polifenóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
3.
Mol Cell ; 75(4): 807-822.e8, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31442424

RESUMO

mTORC2 controls glucose and lipid metabolism, but the mechanisms are unclear. Here, we show that conditionally deleting the essential mTORC2 subunit Rictor in murine brown adipocytes inhibits de novo lipid synthesis, promotes lipid catabolism and thermogenesis, and protects against diet-induced obesity and hepatic steatosis. AKT kinases are the canonical mTORC2 substrates; however, deleting Rictor in brown adipocytes appears to drive lipid catabolism by promoting FoxO1 deacetylation independently of AKT, and in a pathway distinct from its positive role in anabolic lipid synthesis. This facilitates FoxO1 nuclear retention, enhances lipid uptake and lipolysis, and potentiates UCP1 expression. We provide evidence that SIRT6 is the FoxO1 deacetylase suppressed by mTORC2 and show an endogenous interaction between SIRT6 and mTORC2 in both mouse and human cells. Our findings suggest a new paradigm of mTORC2 function filling an important gap in our understanding of this more mysterious mTOR complex.


Assuntos
Adipócitos Marrons/metabolismo , Proteína Forkhead Box O1/metabolismo , Lipólise , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Sirtuínas/metabolismo , Adipócitos Marrons/citologia , Animais , Proteína Forkhead Box O1/genética , Células HEK293 , Células HeLa , Humanos , Alvo Mecanístico do Complexo 2 de Rapamicina/genética , Camundongos , Camundongos Transgênicos , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Proteína Companheira de mTOR Insensível à Rapamicina/metabolismo , Sirtuínas/genética
4.
Int J Mol Sci ; 20(14)2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31323770

RESUMO

The high abundance of mitochondria and the expression of mitochondrial uncoupling protein 1 (UCP1) confer upon brown adipose tissue (BAT) the unique capacity to convert chemical energy into heat at the expense of ATP synthesis. It was long believed that BAT is present only in infants, and so, it was not considered as a potential therapeutic target for metabolic syndrome; however, the discovery of metabolically active BAT in adult humans has re-stimulated interest in the contributions of BAT metabolic regulation and dysfunction to health and disease. Here we demonstrate that brown adipocyte autophagy plays a critical role in the regulation BAT activity and systemic energy metabolism. Mice deficient in brown adipocyte autophagy due to BAT-specific deletion of Atg7-a gene essential for autophagosome generation-maintained higher mitochondrial content due to suppression of mitochondrial clearance and exhibited improved insulin sensitivity and energy metabolism. Autophagy was upregulated in BAT of older mice compared to younger mice, suggesting its involvement in the age-dependent decline of BAT activity and metabolic rate. These findings suggest that brown adipocyte autophagy plays a crucial role in metabolism and that targeting this pathway may be a potential therapeutic strategy for metabolic syndrome.


Assuntos
Adipócitos Marrons/citologia , Adipócitos Marrons/metabolismo , Metabolismo Energético/fisiologia , Mitocôndrias/metabolismo , Envelhecimento/genética , Envelhecimento/fisiologia , Animais , Proteína 7 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/metabolismo , Camundongos , Camundongos Mutantes , /fisiologia
5.
Cells ; 8(7)2019 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-31262098

RESUMO

Obesity is characterized by chronic and low-grade systemic inflammation, an increase of adipose tissue, hypertrophy, and hyperplasia of adipocytes. Adipose tissues can be classified into white, brown, beige and pink adipose tissues, which display different regulatory, morphological and functional characteristics of their adipocyte and immune cells. Brown and white adipocytes can play a key role not only in the control of energy homeostasis, or through the balance between energy storage and expenditure, but also by the modulation of immune and inflammatory responses. Therefore, brown and white adipocytes can orchestrate important immunological crosstalk that may deeply impact the tumor microenvironment and be crucial for cancer establishment and progression. Recent works have indicated that white adipose tissues can undergo a process called browning, in which an inducible brown adipocyte develops. In this review, we depict the mechanisms involved in the differential role of brown, white and pink adipocytes, highlighting their structural, morphological, regulatory and functional characteristics and correlation with cancer predisposition, establishment, and progression. We also discuss the impact of the increased adiposity in the inflammatory and immunological modulation. Moreover, we focused on the plasticity of adipocytes, describing the molecules produced and secreted by those cells, the modulation of the signaling pathways involved in the browning phenomena of white adipose tissue and its impact on inflammation and cancer.


Assuntos
Adiposidade/imunologia , Carcinogênese/imunologia , Inflamação/imunologia , Neoplasias/imunologia , Obesidade/imunologia , Adipócitos Marrons/imunologia , Adipócitos Marrons/metabolismo , Adipócitos Brancos/imunologia , Adipócitos Brancos/metabolismo , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/imunologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/citologia , Tecido Adiposo Branco/imunologia , Tecido Adiposo Branco/metabolismo , Animais , Carcinogênese/patologia , Modelos Animais de Doenças , Progressão da Doença , Metabolismo Energético/imunologia , Humanos , Inflamação/metabolismo , Inflamação/patologia , Neoplasias/metabolismo , Neoplasias/patologia , Obesidade/complicações , Obesidade/metabolismo , Microambiente Tumoral/imunologia
6.
Cells ; 8(6)2019 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-31234575

RESUMO

Induced brown adipocytes (also referred to as beige cells) execute thermogenesis, as do the classical adipocytes by consuming stored lipids, being related to metabolic homeostasis. Treatment of phytochemicals, including berberine (BBR), was reported to induce conversion from white adipocytes to beige cells. In this study, results of microRNA (miRNA)-seq analyses revealed a decrease in miR-92a, of which the transcription is driven by the c13orf25 promoter in BBR-treated 3T3-L1 cells. BBR treatment manipulated the expressions of SP1 and MYC, in turn, reducing the activity of the c13orf25 promoter. A decrease in miR-92a led to an increase in RNA-binding motif protein 4a (RBM4a) expression, which facilitated the beige adipogenesis. Overexpression of miR-92a or depletion of RBM4a reversely interfered with the impact of BBR treatment on the beige adipogenic signatures, gene expressions, and splicing events in 3T3-L1 cells. Our findings demonstrated that BBR treatment enhanced beige adipogenesis of 3T3-L1 cells through transcription-coupled post-transcriptional regulation.


Assuntos
Adipócitos Bege/metabolismo , Adipogenia/genética , Berberina/farmacologia , Transcrição Genética , Células 3T3-L1 , Adipócitos Bege/efeitos dos fármacos , Adipócitos Marrons/efeitos dos fármacos , Adipócitos Marrons/metabolismo , Adipogenia/efeitos dos fármacos , Animais , Sequência de Bases , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Fases de Leitura Aberta/genética , Regiões Promotoras Genéticas/genética , Processamento de RNA/efeitos dos fármacos , Processamento de RNA/genética , Proteínas de Ligação a RNA/metabolismo , Transcrição Genética/efeitos dos fármacos
7.
Cell Biochem Funct ; 37(5): 377-384, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31215681

RESUMO

Dietary vitamin A status affects energy metabolism. The present study explored the effect of all-trans retinoic acid (ATRA) on the expression levels of molecules and metabolites of brown adipocytes. Chronic ATRA treatment was initiated during the early stage (days 0-8) or late stage (days 8-12) of adipogenesis. Treatment with ATRA during the early and late stage of adipogenesis resulted in an increase in the expression level of Ucp1 and Cidea, genes highly expressed in brown adipocytes, on day 8 and day 12, respectively, whereas expression of Pgc-1α, another gene expressed during brown adipogenesis, was unaffected by ATRA. Non-targeted metabolomic analyses indicated that the pathways related to the glucose metabolism were affected by ATRA, irrespective of the differentiation stage. Cellular levels of glucose 6-phosphate, fructose 6-phosphate, citric acid, and succinic acid decreased after ATRA treatment on days 8 and 12. In contrast, glucose level was higher in ATRA-treated cells on day 8, but it was lower on day 12. ATRA decreased the cellular level of aconitic acid, fumaric acid, and malic acid on day 12 but not on day 8. Furthermore, ATRA increased the expression level of Hxk2 and downregulated the expressions of G6pdh and Pfkl/Pfkp on day 8 but not on day 12. Together, the results indicate that the chronic treatment with ATRA stimulated the formation of activated brown adipocytes, eventually leading to alterations in the levels of cellular metabolites related to glucose metabolism. SIGNIFICANCE OF THE STUDY: Significance of the study treatment with all-trans retinoic acid (ATRA) during the early and late stage of adipogenesis increased the expression of Ucp1 and Cidea, genes highly expressed in brown adipocytes, on day 8 and day 12. Cellular levels of glucose 6-phosphate, fructose 6-phosphate, citric acid, and succinic acid decreased after ATRA treatment on days 8 and 12. In contrast, glucose level was higher in ATRA-treated cells on day 8, but it was lower on day 12. The present results indicate that ATRA stimulated the formation of activated brown adipocytes, eventually leading to alterations in the levels of cellular metabolites related to glucose metabolism.


Assuntos
Adipócitos Marrons/efeitos dos fármacos , Adipócitos Marrons/metabolismo , Diferenciação Celular/efeitos dos fármacos , Metabolômica , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Tretinoína/farmacologia , Adipócitos Marrons/citologia , Células Cultivadas , Perfilação da Expressão Gênica , Humanos , RNA/genética , Células-Tronco/citologia , Tretinoína/administração & dosagem
8.
J Agric Food Chem ; 67(22): 6232-6240, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31075194

RESUMO

This study investigated the effects and molecular mechanism of a combination of capsaicin and capsiate on promoting lipid metabolism and inducing browning in 3T3-L1 white adipocytes. The combination significantly suppressed lipid accumulation in adipocytes ( p = 0.019) and robustly improved lipid metabolic profiles, including decreased triacylglycerol (0.6703 ± 0.0385 versus 0.2849 ± 0.0188 mmol/g of protein; p < 0.001), total cholesterol (0.1282 ± 0.0241 versus 0.0651 ± 0.0178 mmol/g of protein; p = 0.003), and low-density lipoprotein cholesterol (0.0021 ± 0.0017 versus 0.0005 ± 0.0002 mmol/g of protein; p = 0.024) and increased high-density lipoprotein cholesterol (0.0162 ± 0.0141 versus 0.1002 ± 0.0167 mmol/g of protein; p = 0.012). Furthermore, this combination markedly upgraded the protein levels of cluster of differentiation 36 ( p = 0.007) and adipose triglyceride lipase ( p = 0.013) and phosphorylation of hormone-sensitive lipase at Ser660, Ser565, and Ser563 ( p < 0.001, p = 0.027, and p = 0.002, respectively), indicating increases of fatty acid transport and lipolysis. The levels of lipid metabolism regulators, phosphorylation of adenosine-monophosphate-activated protein kinases α and ß ( p = 0.011, and p < 0.001, respectively), sirtuin 1 ( p = 0.004), and vanilloid transient receptor subtype I ( p = 0.014) were also increased by the combination. Moreover, the combination greatly activated the browning program in adipocytes, as demonstrated by increases in beige-specific gene and protein. Further research found that the protein levels of peroxisome proliferator-activated receptor γ (PPARγ; p = 0.001) and ß3-adrenergic receptor (ß3-AR; p = 0.026) were elevated by the combination, and most of the beige-specific markers were abolished by pretreatment of antagonists of PPARγ or ß3-AR. In conclusion, these results indicated that a combination of capsaicin and capsiate could induce browning in white adipocytes via activation of the PPARγ/ß3-AR signaling pathway, and this combination might be worth investigating as a potential cure for obesity.


Assuntos
Adipócitos Marrons/citologia , Adipócitos Brancos/efeitos dos fármacos , Capsaicina/análogos & derivados , Capsaicina/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , PPAR gama/metabolismo , Receptores Adrenérgicos beta/metabolismo , Células 3T3-L1 , Adipócitos Marrons/metabolismo , Adipócitos Brancos/citologia , Adipócitos Brancos/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Lipólise/efeitos dos fármacos , Camundongos , PPAR gama/genética , Receptores Adrenérgicos beta/genética , Transdução de Sinais/efeitos dos fármacos
9.
Cells ; 8(4)2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-31022919

RESUMO

Leptin is an important secretory protein that regulates the body's intake and energy consumption, and the functions of the Hh signaling pathway related to white adipocyte browning are controversial. It has been reported that leptin plays a critical role in adipogenesis by regulating the Hh signaling pathway, but whether there is a functional relationship between leptin, the Hh signaling pathway, and adipocyte browning is not clear. In this research, mouse white pre-adipocytes were isolated to explore the influence of the Hh signal pathway and leptin during the process described above. This showed that leptin decreased high fat diet-induced obese mice body weight and inhibited the Hh signaling pathway, which suggested that leptin and the Hh signaling pathway have an important role in obesity. After activation of the Hh signaling pathway, significantly decreased browning fat-relative gene expression levels were recorded, whereas inhibition of the Hh signaling pathway significantly up-regulated the expression of these genes. Similarly, leptin also up-regulated the expression of these genes, and increased mitochondrial DNA content, but decreased the expression of Gli, the key transcription factors of the Hh signaling pathway. In short, the results show that leptin promotes white adipocyte browning through inhibiting the Hh signaling pathway. Overall, these results demonstrate that leptin serves as a potential intervention to decrease obesity by inhibiting the Hh signaling pathway.


Assuntos
Adipócitos/metabolismo , Proteínas Hedgehog/metabolismo , Leptina/metabolismo , Células 3T3-L1 , Adipócitos Bege/metabolismo , Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Adipogenia/genética , Tecido Adiposo Bege/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Adiposidade , Animais , Dieta Hiperlipídica , Leptina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/genética , Transdução de Sinais , Fatores de Transcrição/genética
10.
Cells ; 8(4)2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-31022954

RESUMO

We previously established a method for a directed differentiation of human pluripotent stem cells into classical brown adipocytes (BA) by forming aggregates via massive floating culture in the presence of a specific cytokine cocktail. However, use of recombinant cytokines requires significant cost. Moreover, an enforced differentiation by exogenously added cytokines may amend skewed differentiation propensity of patient's pluripotent stem cells, providing unsatisfactory disease models. Therefore, an exogenous cytokine-free method, where cytokines required for differentiation are provided in an auto/paracrine manner mimicking natural developmental process, is beneficial. Here we show that, if human pluripotent stem cells are cultured as size-controlled spheroids (100-120 µm radius, 2000-2500 cells/spheroid) in a mutually segregated manner with half-change of the medium every other day, they differentiate into classical BA via an authentic MYF5-positive myoblast route in the absence of exogenous cytokines. Differentiated BA exerted thermogenic activity in transplanted mice in response to beta-adrenergic receptor agonist stimuli. The cytokine-free differentiation method has further advantages in exploring BATokines, BA-derived physiologically active substances. Indeed, we have found that BA produces an unknown small (<1000 Da), highly hydrophilic molecule that augments insulin secretion from pancreatic beta cells. Our upgraded technique will contribute to an advancement of stem cell study for diverse purposes.


Assuntos
Adipócitos Marrons/citologia , Diferenciação Celular/fisiologia , Células-Tronco Pluripotentes/citologia , Adipócitos Marrons/metabolismo , Adipócitos Marrons/fisiologia , Animais , Técnicas de Cultura de Células/métodos , Células Cultivadas , Citocinas/farmacologia , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células Secretoras de Insulina/citologia , Camundongos , Células-Tronco Pluripotentes/metabolismo , Esferoides Celulares/metabolismo , Termogênese
11.
Am J Physiol Renal Physiol ; 316(6): F1282-F1292, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30995115

RESUMO

According to recent studies, kidney stones are associated with metabolic syndrome. We focused on brown adipocytes and ß3-stimulant-induced brown-like adipocytes to investigate how these adipocytes influence kidney stone disease. For the interscapular brown adipose tissue (iBAT) removal experiment, mice were subjected to either iBAT removal or sham operation (X-BAT group or sham group), and, after 3 wk, renal crystal deposition was induced by intra-abdominal injection of glyoxylate (GOX) for 6 days. For the ß3-stimulant experiment, mice were administered intra-abdominal injections of the ß3-stimulant (ß3-group) or saline (control group) for 6 days. Thereafter, renal crystal deposition was induced by intra-abdominal injection of GOX for 6 days. iBAT removal decreased the expression of Sod1 and increased that of chemokine (C-C motif) ligand 2 (Ccl2), EGF module-containing mucin-like receptor 1 (Emr1), and tumor necrosis factor (Tnf) in the kidneys. Renal crystal deposition was 2.06-fold higher in the X-BAT group than in the sham group. The ß3-stimulant caused differentiation of white adipocytes into brown-like adipocytes. In the kidneys of the ß3-group, the expression of Ccl2 and Emr1 decreased and that of Sod1 increased. Renal crystal deposition was 0.17-fold lower in the ß3-group than in the control group. In summary, iBAT removal promoted kidney inflammation and renal crystal formation. ß3-Stimulant-induced brown-like adipocytes reduced inflammation and improved antioxidant action in the kidneys, which suppressed renal crystal formation. This is the first report on the therapeutic role of brown and brown-like adipocytes for kidney stone formation.


Assuntos
Adipócitos Marrons/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Tecido Adiposo Marrom/efeitos dos fármacos , Agonistas de Receptores Adrenérgicos beta 3/farmacologia , Dioxóis/farmacologia , Cálculos Renais/prevenção & controle , Receptores Adrenérgicos beta 3/efeitos dos fármacos , Adipócitos Marrons/metabolismo , Adipócitos Marrons/ultraestrutura , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/cirurgia , Tecido Adiposo Marrom/ultraestrutura , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Quimiocina CCL2/metabolismo , Cristalização , Modelos Animais de Doenças , Glioxilatos , Mediadores da Inflamação/metabolismo , Cálculos Renais/metabolismo , Cálculos Renais/patologia , Masculino , Camundongos Endogâmicos C57BL , Receptores Adrenérgicos beta 3/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Transdução de Sinais , Superóxido Dismutase-1/metabolismo
12.
Int J Mol Sci ; 20(7)2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30939750

RESUMO

Obesity is a major risk for diabetes. Brown adipose tissue (BAT) mediates production of heat while white adipose tissue (WAT) function in the storage of fat. Roles of BAT in the treatment of obesity and related disorders warrants more investigation. Peroxisome proliferator activator receptor gamma (PPAR-γ) is the master regulator of both BAT and WAT adipogenesis and has roles in glucose and fatty acid metabolism. Adipose tissue is the major expression site for PPAR-γ. In this study, the effects of rosiglitazone on the brown adipogenesis and the association of MAPK and PI3K pathways was investigated during the in vitro adipogenic differentiation of telomerase transformed mesenchymal stromal cells (iMSCs). Our data indicate that 2 µM rosiglitazone enhanced adipogenesis by over-expression of PPAR-γ and C/EBP-α. More specifically, brown adipogenesis was enhanced by the upregulation of EBF2 and UCP-1 and evidenced by multilocular fatty droplets morphology of the differentiated adipocytes. We also found that rosiglitazone significantly activated MAPK and PI3K pathways at the maturation stage of differentiation. Overall, the results indicate that rosiglitazone induced overexpression of PPAR-γ that in turn enhanced adipogenesis, particularly browning adipogenesis. This study reports the browning effects of rosiglitazone during the differentiation of iMSCs into adipocytes in association with the activation of MAPK and PI3K signaling pathways.


Assuntos
Adipócitos Marrons/efeitos dos fármacos , Adipogenia , Hipoglicemiantes/farmacologia , Sistema de Sinalização das MAP Quinases , Rosiglitazona/farmacologia , Adipócitos Marrons/citologia , Adipócitos Marrons/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Linhagem Celular , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
13.
Food Funct ; 10(4): 2221-2233, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30950462

RESUMO

Zeaxanthin (ZEA), a type of oxygenated carotenoid with strong antioxidant activity, has previously been found to exhibit an anti-lipogenesis effect. In the present study, we investigated the effect of ZEA on brown-like adipocyte formation and mitochondrial biogenesis in 3T3-L1 adipocytes. Brown adipocyte-specific markers, mitochondrial biogenesis and oxidative stress, and the involvement of AMP-activated protein kinase (AMPK) α1 were assessed. ZEA treated adipocytes demonstrated a brown-like pattern, with upregulated expression of uncoupling protein 1 (UCP1) and other brown adipocyte markers. In addition, ZEA intervention induced a dramatic increase in mitochondrial DNA (mtDNA) content and in the mRNA levels of genes associated with mitochondrial biogenesis. Furthermore, ZEA attenuated mitochondrial oxidative damage caused by lipid peroxidation in adipocytes, significantly improved the mitochondrial membrane potential (MMP), and scavenged intracellular reactive oxygen species (ROS) and mitochondrial superoxide. Finally, we concluded that AMPKα1 mediated the ZEA-caused inhibition of lipid accumulation and promotion of brown and beige adipocyte-biomarker expression, as the positive effects of ZEA were diminished by Prkaa1 (AMPKα1) knockdown. These findings demonstrated that ZEA promoted the expression of brown and beige adipogenesis markers and mitochondrial biogenesis, which involved AMPKα1 activation, thus contributing to the anti-obesity effects of ZEA.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos Marrons/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Zeaxantinas/farmacologia , Células 3T3-L1 , Proteínas Quinases Ativadas por AMP/genética , Adipócitos Bege/efeitos dos fármacos , Adipócitos Bege/metabolismo , Adipócitos Marrons/metabolismo , Adipogenia , Animais , Biomarcadores/metabolismo , Camundongos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Biogênese de Organelas
14.
J Pharmacol Exp Ther ; 369(3): 419-427, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30940691

RESUMO

Mirabegron, a ß3-adrenergic receptor agonist, has been shown to stimulate the activity of brown fat and increase the resting metabolic rate in humans. However, it is unknown whether mirabegron can reduce body weight and improve metabolic health. We investigated the antiobesity effects of mirabegron using both in vitro and in vivo models. Mouse brown preadipocytes and 3T3-L1 cells were treated with different concentrations of mirabegron (0.03-3 µg/ml), and the expression of brown fat-related genes was measured by quantitative real-time polymerase chain reaction. Furthermore, male C57BL/6J mice were fed a high-fat diet for 10 weeks, and mirabegron (2 mg/kg body weight) or a vehicle control was delivered to the interscapular brown adipose tissue (iBAT) using ALZET osmotic pumps from week 7 to 10. The metabolic parameters and tissues were analyzed. In both mouse brown preadipocytes and 3T3-L1 cells, mirabegron stimulated uncoupling protein 1 (UCP1) expression. In animal studies, mirabegron-treated mice had a lower body weight and adiposity. Lipid droplets in the iBAT of mirabegron-treated mice were fewer and smaller in size compared with those from vehicle-treated mice. H&E staining and immunohistochemistry indicated that mirabegron increased the abundance of beige cells in inguinal white adipose tissue (iWAT). Compared with vehicle-treated mice, mirabegron-treated mice had a higher gene expression of UCP1 (14-fold) and cell death-inducing DNA fragmentation factor alpha-like effector A (CIDEA) (4-fold) in iWAT. Furthermore, mirabegron-treated mice had improved glucose tolerance and insulin sensitivity. Taken together, mirabegron enhances UCP1 expression and promotes browning of iWAT, which are accompanied by improved glucose tolerance and insulin sensitivity and prevention from high-fat diet-induced obesity.


Assuntos
Acetanilidas/farmacologia , Dieta Hiperlipídica/efeitos adversos , Obesidade/induzido quimicamente , Obesidade/metabolismo , Tiazóis/farmacologia , Células 3T3-L1 , Acetanilidas/uso terapêutico , Adipócitos/efeitos dos fármacos , Adipócitos/patologia , Adipócitos Marrons/efeitos dos fármacos , Adipócitos Marrons/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Homeostase/efeitos dos fármacos , Masculino , Camundongos , Camundongos Obesos , Obesidade/tratamento farmacológico , Obesidade/patologia , Tiazóis/uso terapêutico , Proteína Desacopladora 1/genética
15.
J Vet Med Sci ; 81(5): 646-652, 2019 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-30880304

RESUMO

Activin E, a secreted peptide encoded by the inhibin/activin ßE subunit gene, is a member of the transforming growth factor-ß superfamily, which is predominantly expressed in the liver. Recent reports have suggested that activin E plays a role in energy homeostasis as a hepatokine. Here, using transgenic mice overexpressing activin E under the control of the ß-actin promoter, we demonstrate that activin E controls energy metabolism through brown/beige adipocytes. The glucose tolerance test and insulin tolerance test showed that the insulin sensitivity was improved in the transgenic mice. Furthermore, the mice had a high body temperature compared with wild-type mice. The transgenic brown adipose tissue and mesenteric white adipose tissue showed upregulation of uncoupling protein 1, which enables energy dissipation as heat by uncoupling oxidative phosphorylation from ATP production. Present results indicate that activin E activates energy expenditure through brown/beige adipocyte activation, suggesting that activin E has high potential for obesity therapy.


Assuntos
Ativinas/farmacologia , Adipócitos Bege/metabolismo , Adipócitos Marrons/metabolismo , Resistência à Insulina , Actinas/genética , Actinas/metabolismo , Ativinas/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Temperatura Corporal/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Intolerância à Glucose/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Termogênese/efeitos dos fármacos , Proteína Desacopladora 1/metabolismo
16.
Biomed Pharmacother ; 111: 1156-1165, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30841429

RESUMO

AIMS: We studied the effect of metformin on the brown adipose tissue (BAT) in a fructose-rich-fed model, focusing on BAT proliferation, differentiation, and thermogenic markers. MAIN METHODS: C57Bl/6 mice received isoenergetic diets for ten weeks: control (C) or high-fructose (F). For additional eight weeks, animals received metformin hydrochloride (M, 250 mg/kg/day) or saline. After sacrifice, BAT and white fat pads were prepared for light microscopy and molecular analyses. KEY FINDINGS: Body mass gain, white fat pads, and adiposity index were not different among the groups. There was a reduction in energy intake in the F group and energy expenditure in the F and FM groups. Metformin led to a more massive BAT in both groups CM and FM, associated with a higher adipocyte proliferation (ß1-adrenergic receptor, proliferating cell nuclear antigen, and vascular endothelial growth factor), and differentiation (PR domain containing 16, bone morphogenetic protein 7), in part by activating 5' adenosine monophosphate-activated protein kinase. Metformin also enhanced thermogenic markers in the BAT (uncoupling protein type 1, peroxisome proliferator-activated receptor gamma coactivator-1 alpha) through adrenergic stimuli and fibroblast growth factor 21. Metformin might improve mitochondrial biogenesis in the BAT (nuclear respiratory factor 1, mitochondrial transcription factor A), lipolysis (perilipin, adipose triglyceride lipase, hormone-sensitive lipase), and fatty acid uptake (lipoprotein lipase, cluster of differentiation 36, adipocyte protein 2). SIGNIFICANCE: Metformin effects are not linked to body mass changes, but affect BAT thermogenesis, mitochondrial biogenesis, and fatty acid uptake. Therefore, BAT may be a metformin adjuvant target for the treatment of metabolic disorders.


Assuntos
Adipócitos Marrons/efeitos dos fármacos , Metformina/farmacologia , Mitocôndrias/efeitos dos fármacos , Termogênese/efeitos dos fármacos , Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Animais , Biomarcadores/metabolismo , Índice de Massa Corporal , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Biogênese de Organelas
17.
Diabetes ; 68(6): 1178-1196, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30862682

RESUMO

Carboxylesterase 3 (Ces3) is a hydrolase with a wide range of activities in liver and adipose tissue. In this study, we identified Ces3 as a major lipid droplet surface-targeting protein in adipose tissue upon cold exposure by liquid chromatography-tandem mass spectrometry. To investigate the function of Ces3 in the ß-adrenergic signaling-activated adipocytes, we applied WWL229, a specific Ces3 inhibitor, or genetic inhibition by siRNA to Ces3 on isoproterenol (ISO)-treated 3T3-L1 and brown adipocyte cells. We found that blockage of Ces3 by WWL229 or siRNA dramatically attenuated the ISO-induced lipolytic effect in the cells. Furthermore, Ces3 inhibition led to impaired mitochondrial function measured by Seahorse. Interestingly, Ces3 inhibition attenuated an ISO-induced thermogenic program in adipocytes by downregulating Ucp1 and Pgc1α genes via peroxisome proliferator-activated receptor γ. We further confirmed the effects of Ces3 inhibition in vivo by showing that the thermogenesis in adipose tissues was significantly attenuated in WWL229-treated or adipose tissue-specific Ces3 heterozygous knockout (Adn-Cre-Ces3flx/wt) mice. As a result, the mice exhibited dramatically impaired ability to defend their body temperature in coldness. In conclusion, our study highlights a lipolytic signaling induced by Ces3 as a unique process to regulate thermogenesis in adipose tissue.


Assuntos
Adipócitos Marrons/metabolismo , Tecido Adiposo/metabolismo , Carboxilesterase/fisiologia , Lipólise/genética , Termogênese/genética , Células 3T3-L1 , Adipócitos Marrons/efeitos dos fármacos , Tecido Adiposo/efeitos dos fármacos , Agonistas Adrenérgicos beta/farmacologia , Animais , Carboxilesterase/antagonistas & inibidores , Carboxilesterase/genética , Temperatura Baixa , Regulação para Baixo , Isoproterenol/farmacologia , Lipólise/efeitos dos fármacos , Camundongos , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , PPAR gama/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , RNA Interferente Pequeno , Termogênese/efeitos dos fármacos , Proteína Desacopladora 1/genética
18.
Life Sci ; 222: 117-124, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30708100

RESUMO

Obesity is caused by energy imbalance and accompanied by adipocyte hypertrophy and hyperplasia. Therefore, both enhancement of adipocyte energy expenditure and inhibition of adipogenesis are viable ways to combat obesity. Using the Ucp1-2A-luciferase reporter animal model previously reported by us as a screening platform, a chemical compound Linifanib was identified as a potent inducer of UCP1 expression in primary inguinal adipocytes in vitro and in vivo. Signal pathway analyses showed that Linifanib promoted adipocyte browning by attenuating STAT3 phosphorylation. The effects of Linifanib on adipocyte browning were blocked by the compound, SD19, which activates the STAT3 signaling cascade. Linifanib also inhibited adipocyte differentiation, by blocking mitotic clonal expansion, which could be rescued by STAT3 activator. Taken together, our results indicate that Linifanib might serve as a potential drug for the treatment of obesity.


Assuntos
Adipócitos Marrons/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Fármacos Antiobesidade/farmacologia , Indazóis/farmacologia , Compostos de Fenilureia/farmacologia , Fator de Transcrição STAT3/antagonistas & inibidores , Células 3T3-L1 , Adipócitos Marrons/metabolismo , Adipogenia/fisiologia , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Camundongos , Camundongos Transgênicos , Distribuição Aleatória , Fator de Transcrição STAT3/metabolismo , Smegmamorpha
19.
Internist (Berl) ; 60(2): 115-121, 2019 02.
Artigo em Alemão | MEDLINE | ID: mdl-30617700

RESUMO

The metabolic functions of different kinds of adipose tissue are of growing scientific and clinical interest. White adipose tissue is not only an energy store but as a highly active endocrine organ it also plays an essential role in the development of diabetes mellitus, dyslipidemia, arterial hypertension and cardiovascular diseases. Brown adipose tissue, on the other hand, can convert chemical energy into heat and could therefore have an opposing, protective effect. The activation of brown adipose tissue and the induction of the development of adipocytes with the characteristics of brown fat cells could make a significant contribution to the treatment of these civilization diseases. This article provides an overview of the current understanding of the physiology and pathophysiology of different adipose tissue types and the resulting therapeutic potential.


Assuntos
Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Tecido Adiposo Marrom/metabolismo , Metabolismo Energético/fisiologia , Obesidade/metabolismo , Termogênese/fisiologia , Adipócitos Marrons/fisiologia , Tecido Adiposo , Tecido Adiposo Marrom/fisiologia , Tecido Adiposo Branco/metabolismo , Humanos , Obesidade/fisiopatologia , Ganho de Peso
20.
Biochim Biophys Acta Mol Cell Res ; 1866(3): 337-348, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30595160

RESUMO

The discovery of significant amounts of metabolically active brown adipose tissue (BAT) in adult humans renders it a promising target for anti-obesity therapies by inducing weight loss through increased energy expenditure. The components of the N-acetylaspartate (NAA) pathway are highly abundant in BAT. Aspartate N-acetyltransferase (Asp-NAT, encoded by Nat8l) synthesizes NAA from acetyl-CoA and aspartate and increases energy expenditure in brown adipocytes. However, the exact mechanism how the NAA pathway contributes to accelerated mobilization and oxidation of lipids and the physiological regulation of the NAA pathway remained elusive. Here, we demonstrate that the expression of NAA pathway genes corresponds to nutrient availability and specifically responds to changes in exogenous glucose. NAA is preferentially produced from glucose-derived acetyl-CoA and aspartate and its concentration increases during adipogenesis. Overexpression of Nat8l drains glucose-derived acetyl-CoA into the NAA pool at the expense of cellular lipids and certain amino acids. Mechanistically, we elucidated that a combined activation of neutral and lysosomal (acid) lipolysis is responsible for the increased lipid degradation. Specifically, translocation of the transcription factor EB to the nucleus activates the biosynthesis of autophagosomes and lysosomes. Lipid degradation within lysosomes accompanied by adipose triglyceride lipase-mediated lipolysis delivers fatty acids for the support of elevated mitochondrial respiration. Together, our data suggest a crucial role of the NAA pathway in energy metabolism and metabolic adaptation in BAT.


Assuntos
Adipócitos Marrons/metabolismo , Ácido Aspártico/análogos & derivados , Nutrientes/metabolismo , Acetilcoenzima A/metabolismo , Acetiltransferases/metabolismo , Adipócitos Marrons/fisiologia , Adipogenia/genética , Adipogenia/fisiologia , Tecido Adiposo Marrom/metabolismo , Animais , Ácido Aspártico/genética , Ácido Aspártico/metabolismo , Ácido Aspártico/fisiologia , Metabolismo Energético/fisiologia , Ácidos Graxos/metabolismo , Glucose/metabolismo , Metabolismo dos Lipídeos/fisiologia , Lipídeos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Oxirredução
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