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Sample records for brown adipocytes strategies

  1. Effects of glucocorticoids on human brown adipocytes.

    Science.gov (United States)

    Barclay, Johanna L; Agada, Hadiya; Jang, Christina; Ward, Micheal; Wetzig, Neil; Ho, Ken K Y

    2015-02-01

    Clinical cases of glucocorticoid (GC) excess are characterized by increased fat mass and obesity through the accumulation of white adipocytes. The effects of GCs on growth and function of brown adipose tissue are unknown and may contribute to the negative energy balance observed clinically. This study aims to evaluate the effect of GCs on proliferation, differentiation, and metabolic function of brown adipocytes. Human brown adipocytes sourced from supraclavicular fat biopsies were grown in culture and differentiated to mature adipocytes. Human white adipocytes sourced from subcutaneous abdominal fat biopsies were cultured as controls. Effects of dexamethasone on growth, differentiation (UCP1, CIDEA, and PPARGC1A expression), and function (oxygen consumption rate (OCR)) of brown adipocytes were quantified. Dexamethasone (1 μM) significantly stimulated the proliferation of brown preadipocytes and reduced that of white preadipocytes. During differentiation, dexamethasone (at 0.1, 1, and 10 μM) stimulated the expression of UCP1, CIDEA, and PPARGC1A in a concentration-dependent manner and enhanced by fourfold to sixfold the OCR of brown adipocytes. Isoprenaline (100 nM) significantly increased (POCR of brown adipocytes. These effects were significantly reduced (Pbiology of human brown adipose tissue (BAT) and for the involvement of the BAT system in the metabolic manifestation of Cushing's syndrome. © 2015 Society for Endocrinology.

  2. Mitochondria in White, Brown, and Beige Adipocytes

    Directory of Open Access Journals (Sweden)

    Miroslava Cedikova

    2016-01-01

    Full Text Available Mitochondria play a key role in energy metabolism in many tissues, including cardiac and skeletal muscle, brain, liver, and adipose tissue. Three types of adipose depots can be identified in mammals, commonly classified according to their colour appearance: the white (WAT, the brown (BAT, and the beige/brite/brown-like (bAT adipose tissues. WAT is mainly involved in the storage and mobilization of energy and BAT is predominantly responsible for nonshivering thermogenesis. Recent data suggest that adipocyte mitochondria might play an important role in the development of obesity through defects in mitochondrial lipogenesis and lipolysis, regulation of adipocyte differentiation, apoptosis, production of oxygen radicals, efficiency of oxidative phosphorylation, and regulation of conversion of white adipocytes into brown-like adipocytes. This review summarizes the main characteristics of each adipose tissue subtype and describes morphological and functional modifications focusing on mitochondria and their activity in healthy and unhealthy adipocytes.

  3. Second messenger signaling mechanisms of the brown adipocyte thermogenic program: an integrative perspective.

    Science.gov (United States)

    Shi, Fubiao; Collins, Sheila

    2017-09-26

    β-adrenergic receptors (βARs) are well established for conveying the signal from catecholamines to adipocytes. Acting through the second messenger cyclic adenosine monophosphate (cAMP) they stimulate lipolysis and also increase the activity of brown adipocytes and the 'browning' of adipocytes within white fat depots (so-called 'brite' or 'beige' adipocytes). Brown adipose tissue mitochondria are enriched with uncoupling protein 1 (UCP1), which is a regulated proton channel that allows the dissipation of chemical energy in the form of heat. The discovery of functional brown adipocytes in humans and inducible brown-like ('beige' or 'brite') adipocytes in rodents have suggested that recruitment and activation of these thermogenic adipocytes could be a promising strategy to increase energy expenditure for obesity therapy. More recently, the cardiac natriuretic peptides and their second messenger cyclic guanosine monophosphate (cGMP) have gained attention as a parallel signaling pathway in adipocytes, with some unique features. In this review, we begin with some important historical work that touches upon the regulation of brown adipocyte development and physiology. We then provide a synopsis of some recent advances in the signaling cascades from β-adrenergic agonists and natriuretic peptides to drive thermogenic gene expression in the adipocytes and how these two pathways converge at a number of unexpected points. Finally, moving from the physiologic hormonal signaling, we discuss yet another level of control downstream of these signals: the growing appreciation of the emerging roles of non-coding RNAs as important regulators of brown adipocyte formation and function. In this review, we discuss new developments in our understanding of the signaling mechanisms and factors including new secreted proteins and novel non-coding RNAs that control the function as well as the plasticity of the brown/beige adipose tissue as it responds to the energy needs and environmental

  4. Metabolic interplay between white, beige, brown adipocytes and the liver.

    Science.gov (United States)

    Scheja, Ludger; Heeren, Joerg

    2016-05-01

    In mammalian evolution, three types of adipocytes have developed, white, brown and beige adipocytes. White adipocytes are the major constituents of white adipose tissue (WAT), the predominant store for energy-dense triglycerides in the body that are released as fatty acids during catabolic conditions. The less abundant brown adipocytes, the defining parenchymal cells of brown adipose tissue (BAT), internalize triglycerides that are stored intracellularly in multilocular lipid droplets. Beige adipocytes (also known as brite or inducible brown adipocytes) are functionally very similar to brown adipocytes and emerge in specific WAT depots in response to various stimuli including sustained cold exposure. The activation of brown and beige adipocytes (together referred to as thermogenic adipocytes) causes both the hydrolysis of stored triglycerides as well as the uptake of lipids and glucose from the circulation. Together, these fuels are combusted for heat production to maintain body temperature in mammals including adult humans. Given that heating by brown and beige adipocytes is a very-well controlled and energy-demanding process which entails pronounced shifts in energy fluxes, it is not surprising that an intensive interplay exists between the various adipocyte types and parenchymal liver cells, and that this influences systemic metabolic fluxes and endocrine networks. In this review we will emphasize the role of hepatic factors that regulate the metabolic activity of white and thermogenic adipocytes. In addition, we will discuss the relevance of lipids and hormones that are secreted by white, brown and beige adipocytes regulating liver metabolism in order to maintain systemic energy metabolism in health and disease.

  5. Cannabidiol promotes browning in 3T3-L1 adipocytes.

    Science.gov (United States)

    Parray, Hilal Ahmad; Yun, Jong Won

    2016-05-01

    Recruitment of the brown-like phenotype in white adipocytes (browning) and activation of existing brown adipocytes are currently being investigated as a means to combat obesity. Thus, a wide variety of dietary agents that contribute to browning of white adipocytes have been identified. The present study was designed to investigate the effects of cannabidiol (CBD), a major nonpsychotropic phytocannabinoid of Cannabis sativa, on induction of browning in 3T3-L1 adipocytes. CBD enhanced expression of a core set of brown fat-specific marker genes (Ucp1, Cited1, Tmem26, Prdm16, Cidea, Tbx1, Fgf21, and Pgc-1α) and proteins (UCP1, PRDM16, and PGC-1α). Increased expression of UCP1 and other brown fat-specific markers contributed to the browning of 3T3-L1 adipocytes possibly via activation of PPARγ and PI3K. In addition, CBD increased protein expression levels of CPT1, ACSL, SIRT1, and PLIN while down-regulating JNK2, SREBP1, and LPL. These data suggest possible roles for CBD in browning of white adipocytes, augmentation of lipolysis, thermogenesis, and reduction of lipogenesis. In conclusion, the current data suggest that CBD plays dual modulatory roles in the form of inducing the brown-like phenotype as well as promoting lipid metabolism. Thus, CBD may be explored as a potentially promising therapeutic agent for the prevention of obesity.

  6. Molecular pathways regulating the formation of brown-like adipocytes in white adipose tissue.

    Science.gov (United States)

    Fu, Jianfei; Li, Zhen; Zhang, Huiqin; Mao, Yushan; Wang, Anshi; Wang, Xin; Zou, Zuquan; Zhang, Xiaohong

    2015-07-01

    Adipose tissue is functionally composed of brown adipose tissue and white adipose tissue. The unique thermogenic capacity of brown adipose tissue results from expression of uncoupling protein 1 in the mitochondrial inner membrane. On the basis of recent findings that adult humans have functionally active brown adipose tissue, it is now recognized as playing a much more important role in human metabolism than was previously thought. More importantly, brown-like adipocytes can be recruited in white adipose tissue upon environmental stimulation and pharmacologic treatment, and this change is associated with increased energy expenditure, contributing to a lean and healthy phenotype. Thus, the promotion of brown-like adipocyte development in white adipose tissue offers novel possibilities for the development of therapeutic strategies to combat obesity and related metabolic diseases. In this review, we summarize recent advances in understanding the molecular mechanisms involved in the recruitment of brown-like adipocyte in white adipose tissue.

  7. Chronic activation of pattern recognition receptors suppresses brown adipogenesis of multipotent mesodermal stem cells and brown pre-adipocytes.

    Science.gov (United States)

    Bae, Jiyoung; Chen, Jiangang; Zhao, Ling

    2015-06-01

    Brown adipose tissue (BAT) holds promise to combat obesity through energy-spending, non-shivering thermogenesis. Understanding of regulation of BAT development can lead to novel strategies to increase BAT mass and function for obesity treatment and prevention. Here, we report the effects of chronic activation of PRR on brown adipogenesis of multipotent mesodermal stem C3H10T1/2 cells and immortalized brown pre-adipocytes from the classical interscapular BAT of mice. Activation of NOD1, TLR4, or TLR2 by their respective synthetic ligand suppressed brown marker gene expression and lipid accumulation during differentiation of brown-like adipocytes of C3H10T1/2. Activation of the PRR only during the commitment was sufficient to suppress the differentiation. PRR activation suppressed PGC-1α mRNA, but induced PRDM16 mRNA at the commitment. Consistently, PRR activation suppressed the differentiation of immortalized brown pre-adipocytes. Activation of PRR induced NF-κB activation in both cells, which correlated with their abilities to suppress PPARγ transactivation, a critical event for brown adipogenesis. Taken together, our results demonstrate that chronic PRR activation suppressed brown adipogenesis of multipotent mesodermal stem cells and brown pre-adipocytes, possibly through suppression of PPARγ transactivation. The results suggest that anti- inflammatory therapies targeting PRRs may be beneficial for the BAT development.

  8. Methyltransferase and demethylase profiling studies during brown adipocyte differentiation.

    Science.gov (United States)

    Son, Min Jeong; Kim, Won Kon; Oh, Kyoung-Jin; Park, Anna; Lee, Da Som; Han, Baek Soo; Lee, Sang Chul; Bae, Kwang-Hee

    2016-07-01

    Although brown adipose tissue is important with regard to energy balance, the molecular mechanism of brown adipocyte differentiation has not been extensively studied. Specifically, regulation factors at the level of protein modification are largely unknown. In this study, we examine the changes in the expression level of enzymes which are involved in protein lysine methylation during brown adipocyte differentiation. Several enzymes, in this case SUV420H2, PRDM9, MLL3 and JHDM1D, were found to be up-regulated. On the other hand, Set7/9 was significantly down-regulated. In the case of SUV420H2, the expression level increased sharply during brown adipocyte differentiation, whereas the expression of SUV420H2 was marginally enhanced during the white adipocyte differentiation. The knock-down of SUV420H2 caused the suppression of brown adipocyte differentiation, as compared to a scrambled control. These results suggest that SUV420H2, a methyltransferase, is involved in brown adipocyte differentiation, and that the methylation of protein lysine is important in brown adipocyte differentiation. [BMB Reports 2016; 49(7): 388-393].

  9. White, brown and pink adipocytes: the extraordinary plasticity of the adipose organ.

    Science.gov (United States)

    Giordano, Antonio; Smorlesi, Arianna; Frontini, Andrea; Barbatelli, Giorgio; Cinti, Saverio

    2014-05-01

    In mammals, adipocytes are lipid-laden cells making up the parenchyma of the multi-depot adipose organ. White adipocytes store lipids for release as free fatty acids during fasting periods; brown adipocytes burn glucose and lipids to maintain thermal homeostasis. A third type of adipocyte, the pink adipocyte, has recently been characterised in mouse subcutaneous fat depots during pregnancy and lactation. Pink adipocytes are mammary gland alveolar epithelial cells whose role is to produce and secrete milk. Emerging evidence suggests that they derive from the transdifferentiation of subcutaneous white adipocytes. The functional response of the adipose organ to a range of metabolic and environmental challenges highlights its extraordinary plasticity. Cold exposure induces an increase in the 'brown' component of the organ to meet the increased thermal demand; in states of positive energy balance, the 'white' component expands to store excess nutrients; finally, the 'pink' component develops in subcutaneous depots during pregnancy to ensure litter feeding. At the cell level, plasticity is provided not only by stem cell proliferation and differentiation but also, distinctively, by direct transdifferentiation of fully differentiated adipocytes by the stimuli that induce genetic expression reprogramming and through it a change in phenotype and, consequently function. A greater understanding of adipocyte transdifferentiation mechanisms would have the potential to shed light on their biology as well as inspire novel therapeutic strategies against metabolic syndrome (browning) and breast cancer (pinking).

  10. Modulation of brown adipocyte activity by milk by-products: Stimulation of brown adipogenesis by buttermilk.

    Science.gov (United States)

    Asano, Hiroki; Kida, Ryosuke; Muto, Kengo; Nara, Takayuki Y; Kato, Ken; Hashimoto, Osamu; Kawada, Teruo; Matsui, Tohru; Funaba, Masayuki

    2016-12-01

    Brown adipocytes dissipate chemical energy in the form of heat through the expression of mitochondrial uncoupling protein 1 (Ucp1); Ucp1 expression is further upregulated by the stimulation of β-adrenergic receptors in brown adipocytes. An increase in energy expenditure by activated brown adipocytes potentially contributes to the prevention of or therapeutics for obesity. The present study examined the effects of milk by-products, buttermilk and butter oil, on brown adipogenesis and the function of brown adipocytes. The treatment with buttermilk modulated brown adipogenesis, depending on the product tested; during brown adipogenesis, buttermilk 1 inhibited the differentiation of HB2 brown preadipocytes. In contrast, buttermilk 3 and 5 increased the expression of Ucp1 in the absence of isoproterenol (Iso), a β-adrenergic receptor agonist, suggesting the stimulation of brown adipogenesis. In addition, the Iso-induced expression of Ucp1 was enhanced by buttermilk 2 and 3. The treatment with buttermilk did not affect the basal or induced expression of Ucp1 by Iso in HB2 brown adipocytes, except for buttermilk 5, which increased the basal expression of Ucp1. Conversely, butter oil did not significantly affect the expression of Ucp1, irrespective of the cell phase of HB2 cells, ie, treatment during brown adipogenesis or of brown adipocytes. The results of the present study indicate that buttermilk is a regulator of brown adipogenesis and suggest its usefulness as a potential food material for antiobesity.

  11. Direct action of capsaicin in brown adipogenesis and activation of brown adipocytes.

    Science.gov (United States)

    Kida, Ryosuke; Yoshida, Hirofumi; Murakami, Masaru; Shirai, Mitsuyuki; Hashimoto, Osamu; Kawada, Teruo; Matsui, Tohru; Funaba, Masayuki

    2016-01-01

    The ingestion of capsaicin, the principle pungent component of red and chili peppers, induces thermogenesis, in part, through the activation of brown adipocytes expressing genes related to mitochondrial biogenesis and uncoupling such as peroxisome proliferator-activated receptor (Ppar) γ coactivator-1α (Pgc-1α) and uncoupling protein 1 (Ucp1). Capsaicin has been suggested to induce the activation of brown adipocytes, which is mediated by the stimulation of sympathetic nerves. However, capsaicin may directly affect the differentiation of brown preadipocytes, brown adipocyte function, or both, through its significant absorption. We herein demonstrated that Trpv1, a capsaicin receptor, is expressed in brown adipose tissue, and that its expression level is increased during the differentiation of HB2 brown preadipocytes. Furthermore, capsaicin induced calcium influx in brown preadipocytes. A treatment with capsaicin in the early stage of brown adipogenesis did not affect lipid accumulation or the expression levels of Fabp4 (a gene expressed in mature adipocytes), Pparγ2 (a master regulator of adipogenesis) or brown adipocyte-selective genes. In contrast, a treatment with capsaicin in the late stage of brown adipogenesis slightly increased the expression levels of Fabp4, Pparγ2 and Pgc-1α. Although capsaicin did not affect the basal expression level of Ucp1, Ucp1 induction by forskolin was partially inhibited by capsaicin, irrespective of the dose of capsaicin. The results of the present study suggest the direct effects of capsaicin on brown adipocytes or in the late stage of brown adipogenesis.

  12. Browning of White Adipose Tissue with Roscovitine Induces a Distinct Population of UCP1(+) Adipocytes.

    Science.gov (United States)

    Wang, Hong; Liu, Libin; Lin, Jean Z; Aprahamian, Tamar R; Farmer, Stephen R

    2016-12-13

    Brown-like adipocytes exist in several adipose depots including white (WAT) as well as brown (BAT). Activation of these UCP1(+) cells is a potential therapeutic strategy to combat obesity. Studies have shown that posttranslational modifications of PPARγ regulate select adipocyte programs. Deacetylation of K268 and K293 in the ligand-binding domain of PPARγ by Sirt1 induces browning of WAT. Phosphorylation of S273 of PPARγ by CDK5 or ERK stimulates a diabetogenic program of gene expression in WAT. Here, we report that roscovitine, a CDK inhibitor, prevents S273 phosphorylation and promotes formation of UCP1(+) (brite) adipocytes in WAT. It also enhances energy expenditure as well as prevents diet-induced obesity and insulin resistance. Analysis of fluorescence-activated cell-sorted UCP1(+) adipocytes shows that the mRNA signature of brite adipocytes is distinct from beige adipocytes, which arise through catecholamine signaling. These results suggest that brown-like adipocytes in WAT may arise from multiple origins. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. File list: InP.Adp.20.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Adp.20.AllAg.Brown_adipocytes mm9 Input control Adipocyte Brown adipocytes SRX1...85879,SRX143805,SRX478163 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Adp.20.AllAg.Brown_adipocytes.bed ...

  14. File list: NoD.Adp.10.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  15. File list: InP.Adp.10.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  16. File list: NoD.Adp.05.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Adp.05.AllAg.Brown_adipocytes mm9 No description Adipocyte Brown adipocytes htt...p://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Adp.05.AllAg.Brown_adipocytes.bed ...

  17. File list: InP.Adp.50.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  18. File list: Pol.Adp.10.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  19. File list: Unc.Adp.50.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Adp.50.AllAg.Brown_adipocytes mm9 Unclassified Adipocyte Brown adipocytes SRX97...8685,SRX800022 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Adp.50.AllAg.Brown_adipocytes.bed ...

  20. File list: Pol.Adp.20.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Adp.20.AllAg.Brown_adipocytes mm9 RNA polymerase Adipocyte Brown adipocytes SRX...800010,SRX800016,SRX800017 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Adp.20.AllAg.Brown_adipocytes.bed ...

  1. File list: Oth.Adp.05.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.05.AllAg.Brown_adipocytes mm9 TFs and others Adipocyte Brown adipocytes SRX...RX800019,SRX978691,SRX978690,SRX978689,SRX978688 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Adp.05.AllAg.Brown_adipocytes.bed ...

  2. File list: ALL.Adp.20.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Adp.20.AllAg.Brown_adipocytes mm9 All antigens Adipocyte Brown adipocytes SRX80...X800018,SRX800019,SRX185797,SRX478162 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Adp.20.AllAg.Brown_adipocytes.bed ...

  3. File list: ALL.Adp.05.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Adp.05.AllAg.Brown_adipocytes mm9 All antigens Adipocyte Brown adipocytes SRX80...X185879,SRX978689,SRX978688,SRX478162 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Adp.05.AllAg.Brown_adipocytes.bed ...

  4. File list: NoD.Adp.50.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Adp.50.AllAg.Brown_adipocytes mm9 No description Adipocyte Brown adipocytes htt...p://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Adp.50.AllAg.Brown_adipocytes.bed ...

  5. File list: InP.Adp.05.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Adp.05.AllAg.Brown_adipocytes mm9 Input control Adipocyte Brown adipocytes SRX4...78163,SRX143805,SRX185879 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Adp.05.AllAg.Brown_adipocytes.bed ...

  6. File list: Unc.Adp.20.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Adp.20.AllAg.Brown_adipocytes mm9 Unclassified Adipocyte Brown adipocytes SRX97...8685,SRX800022 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Adp.20.AllAg.Brown_adipocytes.bed ...

  7. File list: Oth.Adp.10.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.10.AllAg.Brown_adipocytes mm9 TFs and others Adipocyte Brown adipocytes SRX...RX800014,SRX978690,SRX978689,SRX978688,SRX800019 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Adp.10.AllAg.Brown_adipocytes.bed ...

  8. File list: Pol.Adp.50.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Adp.50.AllAg.Brown_adipocytes mm9 RNA polymerase Adipocyte Brown adipocytes SRX...800010,SRX800016,SRX800017 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Adp.50.AllAg.Brown_adipocytes.bed ...

  9. File list: Unc.Adp.05.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Adp.05.AllAg.Brown_adipocytes mm9 Unclassified Adipocyte Brown adipocytes SRX97...8685,SRX800022 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Adp.05.AllAg.Brown_adipocytes.bed ...

  10. File list: ALL.Adp.10.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Adp.10.AllAg.Brown_adipocytes mm9 All antigens Adipocyte Brown adipocytes SRX80...X978688,SRX800019,SRX478163,SRX478162 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Adp.10.AllAg.Brown_adipocytes.bed ...

  11. File list: Oth.Adp.50.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.50.AllAg.Brown_adipocytes mm9 TFs and others Adipocyte Brown adipocytes SRX...RX978688,SRX800015,SRX800014,SRX800018,SRX800019 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Adp.50.AllAg.Brown_adipocytes.bed ...

  12. File list: Unc.Adp.10.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Adp.10.AllAg.Brown_adipocytes mm9 Unclassified Adipocyte Brown adipocytes SRX97...8685,SRX800022 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Adp.10.AllAg.Brown_adipocytes.bed ...

  13. File list: Pol.Adp.05.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Adp.05.AllAg.Brown_adipocytes mm9 RNA polymerase Adipocyte Brown adipocytes SRX...800010,SRX800016,SRX800017 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Adp.05.AllAg.Brown_adipocytes.bed ...

  14. File list: Oth.Adp.20.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.20.AllAg.Brown_adipocytes mm9 TFs and others Adipocyte Brown adipocytes SRX...RX978689,SRX800015,SRX800014,SRX800018,SRX800019 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Adp.20.AllAg.Brown_adipocytes.bed ...

  15. File list: ALL.Adp.50.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Adp.50.AllAg.Brown_adipocytes mm9 All antigens Adipocyte Brown adipocytes SRX80...X800019,SRX185797,SRX478163,SRX478162 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Adp.50.AllAg.Brown_adipocytes.bed ...

  16. File list: NoD.Adp.20.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Adp.20.AllAg.Brown_adipocytes mm9 No description Adipocyte Brown adipocytes htt...p://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Adp.20.AllAg.Brown_adipocytes.bed ...

  17. Browning effects of (-)-epicatechin on adipocytes and white adipose tissue.

    Science.gov (United States)

    Varela, Claudia Elena; Rodriguez, Alonso; Romero-Valdovinos, Mirza; Mendoza-Lorenzo, Patricia; Mansour, Christina; Ceballos, Guillermo; Villarreal, Francisco; Ramirez-Sanchez, Israel

    2017-09-15

    In this study, we demonstrate that (-)-epicatechin (Epi), a cacao flavanol, induces the browning of fat by promoting mitochondrial biogenesis, enhancing indicators of mitochondrial structure and function, increasing fatty acid metabolism and upregulating the expression of brown adipose tissue-specific proteins in a high-fat diet mouse model of obesity and in cultured human adipocytes. Epi treatment significantly improved mitochondrial function, as measured by citrate synthase activity, and also reduced protein acetylation of total and specific regulators in both adipose tissue and human adipocytes. Browning of fat via Epi was evidenced by the increased expression of key thermogenic genes, phosphorylation of upstream regulators of fatty acid oxidation, and reduced triglyceride levels. Properly designed clinical trials are needed to explore the potential of Epi as an agent that promotes the browning of fat. Copyright © 2017. Published by Elsevier B.V.

  18. Regulatory circuits controlling white versus brown adipocyte differentiation

    DEFF Research Database (Denmark)

    Hansen, Jacob B; Kristiansen, Karsten

    2006-01-01

    Adipose tissue is a major endocrine organ that exerts a profound influence on whole-body homoeostasis. Two types of adipose tissue exist in mammals: WAT (white adipose tissue) and BAT (brown adipose tissue). WAT stores energy and is the largest energy reserve in mammals, whereas BAT, expressing UCP......1 (uncoupling protein 1), can dissipate energy through adaptive thermogenesis. In rodents, ample evidence supports BAT as an organ counteracting obesity, whereas less is known about the presence and significance of BAT in humans. Despite the different functions of white and brown adipocytes......, knowledge of factors differentially influencing the formation of white and brown fat cells is sparse. Here we summarize recent progress in the molecular understanding of white versus brown adipocyte differentiation, including novel insights into transcriptional and signal transduction pathways. Since...

  19. Attainment of brown adipocyte features in white adipocytes of hormone-sensitive lipase null mice.

    Directory of Open Access Journals (Sweden)

    Kristoffer Ström

    Full Text Available BACKGROUND: Hormone-sensitive lipase (HSL is expressed predominantly in adipose tissue, where it plays an important role in catecholamine-stimulated hydrolysis of stored tri- and diglycerides, thus mobilizing fatty acids. HSL exhibits broad substrate specificity and besides acylglycerides it hydrolyzes cholesteryl esters, retinyl esters and lipoidal esters. Despite its role in fatty acid mobilization, HSL null mice have been shown to be resistant to diet-induced obesity. METHODOLOGY/PRINCIPAL FINDINGS: Following a high-fat diet (HFD regimen, energy expenditure, measured using indirect calorimetry, was increased in HSL null mice. White adipose tissue of HSL null mice was characterized by reduced mass and reduced protein expression of PPARgamma, a key transcription factor in adipogenesis, and stearoyl-CoA desaturase 1, the expression of which is known to be positively correlated to the differentiation state of the adipocyte. The protein expression of uncoupling protein-1 (UCP-1, the highly specific marker of brown adipocytes, was increased 7-fold in white adipose tissue of HSL null mice compared to wildtype littermates. Transmission electron microscopy revealed an increase in the size of mitochondria of white adipocytes of HSL null mice. The mRNA expression of pRb and RIP140 was decreased in isolated white adipocytes, while the expression of UCP-1 and CPT1 was increased in HSL null mice compared to wildtype littermates. Basal oxygen consumption was increased almost 3-fold in white adipose tissue of HSL null mice and was accompanied by increased uncoupling activity. CONCLUSIONS: These data suggest that HSL is involved in the determination of white versus brown adipocytes during adipocyte differentiation The exact mechanism(s underlying this novel role of HSL remains to be elucidated, but it seems clear that HSL is required to sustain normal expression levels of pRb and RIP140, which both promote differentiation into the white, rather than the brown

  20. MicroRNAs are required for the feature maintenance and differentiation of brown adipocytes.

    Science.gov (United States)

    Kim, Hye-Jin; Cho, Hyunjii; Alexander, Ryan; Patterson, Heide Christine; Gu, Minxia; Lo, Kinyui Alice; Xu, Dan; Goh, Vera J; Nguyen, Long N; Chai, Xiaoran; Huang, Cher X; Kovalik, Jean-Paul; Ghosh, Sujoy; Trajkovski, Mirko; Silver, David L; Lodish, Harvey; Sun, Lei

    2014-12-01

    Brown adipose tissue (BAT) is specialized to burn lipids for heat generation as a natural defense against cold and obesity. Previous studies established microRNAs (miRNAs) as essential regulators of brown adipocyte differentiation, but whether miRNAs are required for the feature maintenance of mature brown adipocytes remains unknown. To address this question, we ablated Dgcr8, a key regulator of the miRNA biogenesis pathway, in mature brown as well as in white adipocytes. Adipose tissue-specific Dgcr8 knockout mice displayed enlarged but pale interscapular brown fat with decreased expression of genes characteristic of brown fat and were intolerant to cold exposure. Primary brown adipocyte cultures in vitro confirmed that miRNAs are required for marker gene expression in mature brown adipocytes. We also demonstrated that miRNAs are essential for the browning of subcutaneous white adipocytes in vitro and in vivo. Using this animal model, we performed miRNA expression profiling analysis and identified a set of BAT-specific miRNAs that are upregulated during brown adipocyte differentiation and enriched in brown fat compared with other organs. We identified miR-182 and miR-203 as new regulators of brown adipocyte development. Taken together, our study demonstrates an essential role of miRNAs in the maintenance as well as in the differentiation of brown adipocytes.

  1. MicroRNAs Are Required for the Feature Maintenance and Differentiation of Brown Adipocytes

    Science.gov (United States)

    Kim, Hye-Jin; Cho, Hyunjii; Alexander, Ryan; Patterson, Heide Christine; Gu, Minxia; Lo, Kinyui Alice; Xu, Dan; Goh, Vera J.; Nguyen, Long N.; Chai, Xiaoran; Huang, Cher X.; Kovalik, Jean-Paul; Ghosh, Sujoy; Trajkovski, Mirko; Silver, David L.; Lodish, Harvey

    2014-01-01

    Brown adipose tissue (BAT) is specialized to burn lipids for heat generation as a natural defense against cold and obesity. Previous studies established microRNAs (miRNAs) as essential regulators of brown adipocyte differentiation, but whether miRNAs are required for the feature maintenance of mature brown adipocytes remains unknown. To address this question, we ablated Dgcr8, a key regulator of the miRNA biogenesis pathway, in mature brown as well as in white adipocytes. Adipose tissue–specific Dgcr8 knockout mice displayed enlarged but pale interscapular brown fat with decreased expression of genes characteristic of brown fat and were intolerant to cold exposure. Primary brown adipocyte cultures in vitro confirmed that miRNAs are required for marker gene expression in mature brown adipocytes. We also demonstrated that miRNAs are essential for the browning of subcutaneous white adipocytes in vitro and in vivo. Using this animal model, we performed miRNA expression profiling analysis and identified a set of BAT-specific miRNAs that are upregulated during brown adipocyte differentiation and enriched in brown fat compared with other organs. We identified miR-182 and miR-203 as new regulators of brown adipocyte development. Taken together, our study demonstrates an essential role of miRNAs in the maintenance as well as in the differentiation of brown adipocytes. PMID:25008181

  2. The emergence of cold-induced brown adipocytes in mouse white fat depots is determined predominantly by white to brown adipocyte transdifferentiation

    DEFF Research Database (Denmark)

    Barbatelli, G.; Murano, I.; Madsen, Lise;

    2010-01-01

    The origin of brown adipocytes arising in white adipose tissue (WAT) after cold acclimatization is unclear. Here, we demonstrate that several UCP1-immunoreactive brown adipocytes occurring in WAT after cold acclimatization have a mixed morphology (paucilocular adipocytes). These cells also had a ...... for C/EBP (an antimitotic protein), whereas Ccna1 expression (related to cell proliferation) was unchanged. Overall, our data strongly suggest that the cold-induced emergence of brown adipocytes in WAT predominantly reflects ß3-adrenoceptor-mediated transdifferentiation....

  3. Regulation of brown adipocyte metabolism by myostatin/follistatin signaling

    Directory of Open Access Journals (Sweden)

    Rajan eSingh

    2014-10-01

    Full Text Available Obesity develops from perturbations of cellular bioenergetics, when energy uptake exceeds energy expenditure, and represents a major risk factor for the development of type 2 diabetes, dyslipidemia, cardiovascular disease, cancer, and other conditions. Brown adipose tissue (BAT has long been known to dissipate energy as heat and contribute to energy expenditure, but its presence and physiological role in adult human physiology has been questioned for years. Recent demonstrations of metabolically active brown fat depots in adult humans have revolutionized current therapeutic approaches for obesity-related diseases. The balance between white adipose tissue (WAT and BAT affects the systemic energy balance and is widely believed to be the key determinant in the development of obesity and related metabolic diseases. Members of the transforming growth factor-beta (TGF-β superfamily play an important role in regulating overall energy homeostasis by modulation of brown adipocyte characteristics. Inactivation of TGF-β/Smad3/myostatin (Mst signaling promotes browning of white adipocytes, increases mitochondrial biogenesis and protects mice from diet-induced obesity, suggesting the need for development of a novel class of TGF-β/Mst antagonists for the treatment of obesity and related metabolic diseases. We recently described an important role of follistatin (Fst, a soluble glycoprotein that is known to bind and antagonize Mst actions, during brown fat differentiation and the regulation of cellular metabolism. Here we highlight various investigations performed using different in vitro and in vivo models to support the contention that targeting TGF-β/Mst signaling enhances brown adipocyte functions and regulates energy balance, reducing insulin resistance and curbing the development of obesity and diabetes.

  4. An siRNA-based method for efficient silencing of gene expression in mature brown adipocytes.

    Science.gov (United States)

    Isidor, Marie S; Winther, Sally; Basse, Astrid L; Petersen, M Christine H; Cannon, Barbara; Nedergaard, Jan; Hansen, Jacob B

    2016-01-01

    Brown adipose tissue is a promising therapeutic target for opposing obesity, glucose intolerance and insulin resistance. The ability to modulate gene expression in mature brown adipocytes is important to understand brown adipocyte function and delineate novel regulatory mechanisms of non-shivering thermogenesis. The aim of this study was to optimize a lipofection-based small interfering RNA (siRNA) transfection protocol for efficient silencing of gene expression in mature brown adipocytes. We determined that a critical parameter was to deliver the siRNA to mature adipocytes by reverse transfection, i.e. transfection of non-adherent cells. Using this protocol, we effectively knocked down both high- and low-abundance transcripts in a model of mature brown adipocytes (WT-1) as well as in primary mature mouse brown adipocytes. A functional consequence of the knockdown was confirmed by an attenuated increase in uncoupled respiration (thermogenesis) in response to β-adrenergic stimulation of mature WT-1 brown adipocytes transfected with uncoupling protein 1 siRNA. Efficient gene silencing was also obtained in various mouse and human white adipocyte models (3T3-L1, primary mouse white adipocytes, hMADS) with the ability to undergo "browning." In summary, we report an easy and versatile reverse siRNA transfection protocol to achieve specific silencing of gene expression in various models of mature brown and browning-competent white adipocytes, including primary cells.

  5. TSH effects on thermogenesis in rat brown adipocytes.

    Science.gov (United States)

    Martinez-deMena, Raquel; Anedda, Andrea; Cadenas, Susana; Obregon, Maria-Jesus

    2015-03-15

    TSH receptor (TSHR) is present in the thyroid and other tissues, as adipose tissue. In brown adipose tissue (BAT) TSH increases UCP1 expression and lipolysis. We have studied the regulation of Tshr mRNA expression and the effect of TSH on Ucp1 and Dio2 mRNA, on D2 activity and O2 consumption in rat brown adipocytes and the TSH signaling pathways. Tshr increased during brown adipocyte differentiation, was up-regulated by insulin and low TSH concentrations and down-regulated by high TSH concentrations, T3 and/or NE. TSH increased basal Ucp1 mRNA in a dose-dependent way acting synergistically with T3, while had no effect when NE was present. High TSH concentrations increased basal Dio2 mRNA (12-fold) and were synergistic with T3 (100-fold), but decreased Dio2 mRNA in T3+NE-treated cells. TSH increased D2 activities in T3-treated cells and inhibition of ERK pathway decreased the TSH effect by 55%. In T3+NE treated-cells TSH decreased D2 activity by 50%, in a dose-dependent manner. TSH activated Akt and Erk phosphorylation, while inhibition of PKA promoted Akt phosphorylation. TSH inhibited leptin mRNA. TSH increased O2 consumption by 20% and T3 enhanced its effect. Tshr is expressed in brown adipocytes and is regulated by insulin, TSH, T3 and NE. TSH increases basal and T3-stimulated Ucp1 and Dio2 expression and D2 activity only when T3 is present, but decreases Dio2 mRNA and D2 activity stimulated by NE+T3. TSH increases O2 consumption, confirming the role of TSH in the maintenance of thermogenesis.

  6. Retinoblastoma protein functions as a molecular switch determining white versus brown adipocyte differentiation

    DEFF Research Database (Denmark)

    Hansen, Jacob B; Jørgensen, Claus; Petersen, Rasmus K

    2004-01-01

    Adipocyte precursor cells give raise to two major cell populations with different physiological roles: white and brown adipocytes. Here we demonstrate that the retinoblastoma protein (pRB) regulates white vs. brown adipocyte differentiation. Functional inactivation of pRB in wild-type mouse embryo...... into adipocytes with a gene expression pattern and mitochondria content resembling brown adipose tissue. pRB-deficient MEFs exhibit an increased expression of the Forkhead transcription factor Foxc2 and its target gene cAMP-dependent protein kinase regulatory subunit RIalpha, resulting in increased c...... transdifferentiation of white into brown adipocytes in response to beta3-adrenergic receptor agonist treatment. We propose that pRB acts as a molecular switch determining white vs. brown adipogenesis, suggesting a previously uncharacterized function of this key cell cycle regulator in adipocyte lineage commitment...

  7. PPAR{alpha} does not suppress muscle-associated gene expression in brown adipocytes but does influence expression of factors that fingerprint the brown adipocyte

    Energy Technology Data Exchange (ETDEWEB)

    Walden, Tomas B.; Petrovic, Natasa [The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, SE-106 91 Stockholm (Sweden); Nedergaard, Jan, E-mail: jan@metabol.su.se [The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, SE-106 91 Stockholm (Sweden)

    2010-06-25

    Brown adipocytes and myocytes develop from a common adipomyocyte precursor. PPAR{alpha} is a nuclear receptor important for lipid and glucose metabolism. It has been suggested that in brown adipose tissue, PPAR{alpha} represses the expression of muscle-associated genes, in this way potentially acting to determine cell fate in brown adipocytes. To further understand the possible role of PPAR{alpha} in these processes, we measured expression of muscle-associated genes in brown adipose tissue and brown adipocytes from PPAR{alpha}-ablated mice, including structural genes (Mylpf, Tpm2, Myl3 and MyHC), regulatory genes (myogenin, Myf5 and MyoD) and a myomir (miR-206). However, in our hands, the expression of these genes was not influenced by the presence or absence of PPAR{alpha}, nor by the PPAR{alpha} activator Wy-14,643. Similarly, the expression of genes common for mature brown adipocyte and myocytes (Tbx15, Meox2) were not affected. However, the brown adipocyte-specific regulatory genes Zic1, Lhx8 and Prdm16 were affected by PPAR{alpha}. Thus, it would not seem that PPAR{alpha} represses muscle-associated genes, but PPAR{alpha} may still play a role in the regulation of the bifurcation of the adipomyocyte precursor into a brown adipocyte or myocyte phenotype.

  8. Silica nanoparticles inhibit brown adipocyte differentiation via regulation of p38 phosphorylation

    Science.gov (United States)

    Son, Min Jeong; Kim, Won Kon; Kwak, Minjeong; Oh, Kyoung-Jin; Chang, Won Seok; Min, Jeong-Ki; Lee, Sang Chul; Song, Nam Woong; Bae, Kwang-Hee

    2015-10-01

    Nanoparticles are of great interest due to their wide variety of biomedical and bioengineering applications. However, they affect cellular differentiation and/or intracellular signaling when applied and exposed to target organisms or cells. The brown adipocyte is a cell type important in energy homeostasis and thus closely related to obesity. In this study, we assessed the effects of silica nanoparticles (SNPs) on brown adipocyte differentiation. The results clearly showed that brown adipocyte differentiation was significantly repressed by exposure to SNPs. The brown adipocyte-specific genes as well as mitochondrial content were also markedly reduced. Additionally, SNPs led to suppressed p38 phosphorylation during brown adipocyte differentiation. These effects depend on the size of SNPs. Taken together, these results lead us to suggest that SNP has anti-brown adipogenic effect in a size-dependent manner via regulation of p38 phosphorylation.

  9. Brown and brite adipocytes: Same function, but different origin and response.

    Science.gov (United States)

    Chu, Dinh-Toi; Gawronska-Kozak, Barbara

    2017-07-01

    Inducing brown adipocytes in white adipose tissues is a promising target to combat obesity and its related disorders in human beings. This goal has been especially encouraged by new important discoveries of human brown adipose tissues. The accumulating evidence confirms the presence of active brown adipocytes, not only in newborns, but also in adult humans. In rodents, there are two populations of the Ucp1-expressing adipocytes with well characterized-thermogenic functions, classical interscapular brown adipocytes and brite/beige adipocytes (brown adipocytes that are induced in white adipose tissues). Importantly, the anatomical localization, gene expression profiling and functional characterization of Ucp1-expressing fat cells indicates brite and brown adipocytes coexist in human beings. Therefore, the research directions of brown and brite adipogenesis provide lead to potential new therapies to fight obesity and its related metabolic diseases in human being. The objectives of this review are (1) to discuss the fate of primary adipocytes based on tissue origins, and (2) to discuss mechanisms of brown and brite adipogenesis which could lead to their different responses to browning reagents. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. MicroRNA networks regulate development of brown adipocytes.

    Science.gov (United States)

    Trajkovski, Mirko; Lodish, Harvey

    2013-09-01

    Brown adipose tissue (BAT) is specialized for heat generation and energy expenditure as a defense against cold and obesity; in both humans and mice increased amounts of BAT are associated with a lean phenotype and resistance to development of the metabolic syndrome and its complications. Here we summarize recent research showing that several BAT-expressed microRNAs (miRNAs) play important roles in regulating differentiation and metabolism of brown and beige adipocytes; we discuss the key mRNA targets downregulated by these miRNAs and show how these miRNAs affect directly or indirectly transcription factors important for BAT development. We suggest that these miRNAs could be part of novel therapeutics to increase BAT in humans.

  11. A novel crosstalk between Alk7 and cGMP signaling differentially regulates brown adipocyte function

    Directory of Open Access Journals (Sweden)

    Aileen Balkow

    2015-08-01

    Conclusions: We found a so far unknown crosstalk between cGMP and Alk7 signaling pathways. Tight regulation of Alk7 is required for efficient differentiation of brown adipocytes. Alk7 has differential effects on adipogenic differentiation and the development of the thermogenic program in brown adipocytes.

  12. Differentiation of human adipose-derived stem cells into brite (brown-in-white adipocytes

    Directory of Open Access Journals (Sweden)

    Didier F Pisani

    2011-11-01

    Full Text Available It is well established now that adult humans possess active brown adipose tissue which represents a potential pharmacological target to combat obesity and associated diseases. We had shown previously that human multipotent adipose-derived stem (hMADS cells are able to differentiate into cells which exhibit the key properties of human white adipocytes, and to convert into functional brown adipocytes upon PPARγ activation that could explain UCP1-expressing cells within islets surrounded by white adipocytes. Herein we further characterize hMADS cells differentiation into brown adipocytes that behave like mouse brite adipocytes previously described. We analyzed the expression of gene markers known to be associated with mouse white and brown adipocytes. When shifting from a white to a brown fat cell phenotype, the striking enhancement of uncoupling activity appears mainly due, if not all, to an increase in UCP1 expression whereas induction of UCP2 is weak and UCP3 expression is unchanged. Conversion of white hMADS adipocytes is dependent on PPARγ activation with rosiglitazone as the most potent agonist and is inhibited by a PPARγ antagonist. Furthermore our data show that, in contrast to mouse cellular models, hMADS cells conversion into brown adipocytes is not induced by BMP7 treatment and not modulated by activation of the Hedgehog pathway. No primary or clonal precursor cells of human brown adipocytes have been obtained so far that can be used as a tool to develop therapeutic drugs and to gain further insights into the molecular mechanisms of brown adipogenesis in humans. Thus hMADS cells represent a suitable cell model to delineate the formation and/or the uncoupling capacity of human brown/brite adipocytes that could help to dissipate caloric excess intake among individuals.

  13. Myostatin inhibits brown adipocyte differentiation via regulation of Smad3-mediated β-catenin stabilization.

    Science.gov (United States)

    Kim, Won Kon; Choi, Hye-Ryung; Park, Sung Goo; Ko, Yong; Bae, Kwang-Hee; Lee, Sang Chul

    2012-02-01

    Brown adipocytes play an important role in regulating energy balance, and there is a good correlation between obesity and the amount of brown adipose tissue. Although the molecular mechanism of white adipocyte differentiation has been well characterized, brown adipogenesis has not been studied extensively. Moreover, extracellular factors that regulate brown adipogenic differentiation are not fully understood. Here, we assessed the mechanism of the regulatory action of myostatin in brown adipogenic differentiation using primary brown preadipocytes. Our results clearly showed that differentiation of brown adipocytes was significantly inhibited by myostatin treatment. In addition, myostatin-induced suppression of brown adipogenesis was observed during the early phase of differentiation. Myostatin induced the phosphorylation of Smad3, which led to increased β-catenin stabilization. These effects were blocked by treatment with a Smad3 inhibitor. Expression of brown adipocyte-related genes, such as PPAR-γ, UCP-1, PGC-1α, and PRDM16, were dramatically down-regulated by treatment with myostatin, and further down-regulated by co-treatment with a β-catenin activator. Taken together, the present study demonstrated that myostatin is a potent negative regulator of brown adipogenic differentiation by modulation of Smad3-induced β-catenin stabilization. Our findings suggest that myostatin could be used as an extracellular factor in the control of brown adipocyte differentiation.

  14. Pref-1 in brown adipose tissue: specific involvement in brown adipocyte differentiation and regulatory role of C/EBPδ.

    Science.gov (United States)

    Armengol, Jordi; Villena, Josep A; Hondares, Elayne; Carmona, María C; Sul, Hei Sook; Iglesias, Roser; Giralt, Marta; Villarroya, Francesc

    2012-05-01

    Pref-1 (pre-adipocyte factor-1) is known to play a central role in regulating white adipocyte differentiation, but the role of Pref-1 in BAT (brown adipose tissue) has not been analysed. In the present study we found that Pref-1 expression is high in fetal BAT and declines progressively after birth. However, Pref-1-null mice showed unaltered fetal development of BAT, but exhibited signs of over-activation of BAT thermogenesis in the post-natal period. In C/EBP (CCAAT/enhancer-binding protein) α-null mice, a rodent model of impaired fetal BAT differentiation, Pref-1 was dramatically overexpressed, in association with reduced expression of the Ucp1 (uncoupling protein 1) gene, a BAT-specific marker of thermogenic differentiation. In brown adipocyte cell culture models, Pref-1 was mostly expressed in pre-adipocytes and declined with brown adipocyte differentiation. The transcription factor C/EBPδ activated the Pref-1 gene transcription in brown adipocytes, through binding to the proximal promoter region. Accordingly, siRNA (small interfering RNA)-induced C/EBPδ knockdown led to reduced Pref-1 gene expression. This effect is consistent with the observed overexpression of C/EBPδ in C/EBPα-null BAT and high expression of C/EBPδ in brown pre-adipocytes. Dexamethasone treatment of brown pre-adipocytes suppressed Pref-1 down-regulation occurring throughout the brown adipocyte differentiation process, increased the expression of C/EBPδ and strongly impaired expression of the thermogenic markers UCP1 and PGC-1α [PPARγ (peroxisome-proliferator-activated receptor γ) co-activator-α]. However, it did not alter normal fat accumulation or expression of non-BAT-specific genes. Collectively, these results specifically implicate Pref-1 in controlling the thermogenic gene expression program in BAT, and identify C/EBPδ as a novel transcriptional regulator of Pref-1 gene expression that may be related to the specific role of glucocorticoids in BAT differentiation.

  15. Browning of human adipocytes requires KLF11 and reprogramming of PPARγ superenhancers

    DEFF Research Database (Denmark)

    Loft, Anne; Forss, Isabel; Siersbæk, Majken Storm

    2015-01-01

    Long-term exposure to peroxisome proliferator-activated receptor γ (PPARγ) agonists such as rosiglitazone induces browning of rodent and human adipocytes; however, the transcriptional mechanisms governing this phenotypic switch in adipocytes are largely unknown. Here we show that rosiglitazone...... reprogramming of PPARγ binding, leading to the formation of PPARγ "superenhancers" that are selective for brown-in-white (brite) adipocytes. These are highly associated with key brite-selective genes. Based on such an association, we identified an evolutionarily conserved metabolic regulator, Kruppel......-like factor 11 (KLF11), as a novel browning transcription factor in human adipocytes that is required for rosiglitazone-induced browning, including the increase in mitochondrial oxidative capacity. KLF11 is directly induced by PPARγ and appears to cooperate with PPARγ in a feed-forward manner to activate...

  16. Ubc9 Impairs Activation of the Brown Fat Energy Metabolism Program in Human White Adipocytes.

    Science.gov (United States)

    Hartig, Sean M; Bader, David A; Abadie, Kathleen V; Motamed, Massoud; Hamilton, Mark P; Long, Weiwen; York, Brian; Mueller, Michaela; Wagner, Martin; Trauner, Michael; Chan, Lawrence; Bajaj, Mandeep; Moore, David D; Mancini, Michael A; McGuire, Sean E

    2015-09-01

    Insulin resistance and type 2 diabetes mellitus (T2DM) result from an inability to efficiently store and catabolize surplus energy in adipose tissue. Subcutaneous adipocytes protect against insulin resistance and T2DM by coupling differentiation with the induction of brown fat gene programs for efficient energy metabolism. Mechanisms that disrupt these programs in adipocytes are currently poorly defined, but represent therapeutic targets for the treatment of T2DM. To gain insight into these mechanisms, we performed a high-throughput microscopy screen that identified ubiquitin carrier protein 9 (Ubc9) as a negative regulator of energy storage in human sc adipocytes. Ubc9 depletion enhanced energy storage and induced the brown fat gene program in human sc adipocytes. Induction of adipocyte differentiation resulted in decreased Ubc9 expression commensurate with increased brown fat gene expression. Thiazolidinedione treatment reduced the interaction between Ubc9 and peroxisome proliferator-activated receptor (PPAR)γ, suggesting a mechanism by which Ubc9 represses PPARγ activity. In support of this hypothesis, Ubc9 overexpression remodeled energy metabolism in human sc adipocytes by selectively inhibiting brown adipocyte-specific function. Further, Ubc9 overexpression decreased uncoupling protein 1 expression by disrupting PPARγ binding at a critical uncoupling protein 1 enhancer region. Last, Ubc9 is significantly elevated in sc adipose tissue isolated from mouse models of insulin resistance as well as diabetic and insulin-resistant humans. Taken together, our findings demonstrate a critical role for Ubc9 in the regulation of sc adipocyte energy homeostasis.

  17. The Possible Potentiating Role of Endoplasmic Reticulum Stress Response Inhibitors in Trans-Differentiation of white to Brown Adipocytes

    Directory of Open Access Journals (Sweden)

    Ali Mohammad Sharifi

    2012-01-01

    Full Text Available The brown adipose tissue (BAT is an organ with the specialised function of intracellular fat oxidation; in other words, brown fat points to a potential natural tool by which energy expenditure is being stimulated. Obesity is a serious illness which can lead to many medical complications such as cardiovascular disorders. The BAT production, therefore, could be a promising therapeutic strategy for managing obesity. While different approaches have been examined to generate brown adipocytes from various precursor cells, no study has proposed an efficient procedure for direct trans-differentiation of white to brown adipocytes. Bone morphogenic protein (BMP-7 is a possible potential agent by which most of the main factors involved in induction of brown adipocytogenesis such as early regulators of brown fat fate, positive regulatory domain containing 16 (PRDM16 and peroxisome proliferator-activated receptor gamma (PPARγ coactivator-1 alpha (PGC-1α are stimulated, but the rate of success was not so promising. It has been documented that mature white adipocytes exert endoplasmic reticulum stress response (ESR and consequently unfolded protein response (UPR becomes activated for the purpose of ESR recovery since the ESR exceeds the capacity of UPR to overcome the imposed stress, and in turn disables the cell to manage the protein synthesis cascade including those required for BMP-7 induction of brown adipogenesis. This was performed using three main ESR sensors: PKR-like endoplasmic reticulum kinase (PERK, inositol requiring enzyme-1 (IRE-1 and activating transcription factor 6 alpha (ATF-6α resulting in attenuation of protein translation by blocking the activation of transcriptional machinery of UPR genes and the cell behaviour would also be changed towards apoptosis.It may suggest and propose the hypothesis that pretreatment of the white adipocyte with an ESR inhibitor such as salubrinal by reducing ESR and turning on the protein synthesis machinery

  18. The adipocyte clock controls brown adipogenesis through the TGF-Beta and BMP signaling pathways

    Science.gov (United States)

    The molecular clock is intimately linked to metabolic regulation, and brown adipose tissue plays a key role in energy homeostasis. However, whether the cell-intrinsic clock machinery participates in brown adipocyte development is unknown. Here, we show that Bmal1 (also known as ARNTL), the essential...

  19. Susceptibility of brown adipocytes to pro-inflammatory cytokine toxicity and reactive oxygen species.

    Science.gov (United States)

    Rebiger, Lars; Lenzen, Sigurd; Mehmeti, Ilir

    2016-01-21

    Brown adipose tissue (BAT) cells have a very high oxidative capacity. On the other hand, in obesity and obesity-related diabetes, levels of pro-inflammatory cytokines are elevated, which might promote BAT dysfunction and consequently impair carbohydrate metabolism and thereby exacerbate cellular dysfunction and promote diabetes progression. Therefore, the antioxidative enzyme status of a brown adipocyte cell line and its susceptibility towards pro-inflammatory cytokines, which participate in the pathogenesis of diabetes, and reactive oxygen species (ROS) were analysed. Mature brown adipocytes exhibited significantly higher levels of expression of mitochondrially and peroxisomally located antioxidative enzymes compared with non-differentiated brown adipocytes. Pro-inflammatory cytokines induced a significant decrease in the viability of differentiated brown adipocytes, which was accompanied by a massive ROS production and down-regulation of BAT-specific markers, such as uncoupling protein 1 (UCP-1) and β-Klotho. Taken together, the results strongly indicate that pro-inflammatory cytokines cause brown adipocyte dysfunction and death through suppression of BAT-specific proteins, especially of UCP-1 and β-Klotho, and consequently increased oxidative stress.

  20. The orphan nuclear receptor SHP regulates PGC-1alpha expression and energy production in brown adipocytes.

    Science.gov (United States)

    Wang, Li; Liu, Jun; Saha, Pradip; Huang, Jiansheng; Chan, Lawrence; Spiegelman, Bruce; Moore, David D

    2005-10-01

    Brown adipocytes increase energy production in response to induction of PGC-1alpha, a dominant regulator of energy metabolism. We have found that the orphan nuclear receptor SHP (NR0B2) is a negative regulator of PGC-1alpha expression in brown adipocytes. Mice lacking SHP show increased basal expression of PGC-1alpha, increased energy expenditure, and resistance to diet-induced obesity. Increased PGC-1alpha expression in SHP null brown adipose tissue is not due to beta-adrenergic activation, since it is also observed in primary cultures of SHP(-/-) brown adipocytes that are not exposed to such stimuli. In addition, acute inhibition of SHP expression in cultured wild-type brown adipocytes increases basal PGC-1alpha expression, and SHP overexpression in SHP null brown adipocytes decreases it. The orphan nuclear receptor ERRgamma is expressed in BAT and its transactivation of the PGC-1alpha promoter is potently inhibited by SHP. We conclude that SHP functions as a negative regulator of energy production in BAT.

  1. The brown adipocyte differentiation pathway in birds: An evolutionary road not taken

    Directory of Open Access Journals (Sweden)

    Kumaratilake Jaliya S

    2008-04-01

    Full Text Available Abstract Background Thermogenic brown adipose tissue has never been described in birds or other non-mammalian vertebrates. Brown adipocytes in mammals are distinguished from the more common white fat adipocytes by having numerous small lipid droplets rather than a single large one, elevated numbers of mitochondria, and mitochondrial expression of the nuclear gene UCP1, the uncoupler of oxidative phosphorylation responsible for non-shivering thermogenesis. Results We have identified in vitro inductive conditions in which mesenchymal cells isolated from the embryonic chicken limb bud differentiate into avian brown adipocyte-like cells (ABALCs with the morphological and many of the biochemical properties of terminally differentiated brown adipocytes. Avian, and as we show here, lizard species lack the gene for UCP1, although it is present in amphibian and fish species. While ABALCs are therefore not functional brown adipocytes, they are generated by a developmental pathway virtually identical to brown fat differentiation in mammals: both the common adipogenic transcription factor peroxisome proliferator-activated receptor-γ (PPARγ, and a coactivator of that factor specific to brown fat differentiation in mammals, PGC1α, are elevated in expression, as are mitochondrial volume and DNA. Furthermore, ABALCs induction resulted in strong transcription from a transfected mouse UCP1 promoter. Conclusion These findings strongly suggest that the brown fat differentiation pathway evolved in a common ancestor of birds and mammals and its thermogenicity was lost in the avian lineage, with the degradation of UCP1, after it separated from the mammalian lineage. Since this event occurred no later than the saurian ancestor of birds and lizards, an implication of this is that dinosaurs had neither UCP1 nor canonically thermogenic brown fat.

  2. Novel function of the retinoblastoma protein in fat: regulation of white versus brown adipocyte differentiation

    DEFF Research Database (Denmark)

    Hansen, Jacob B; te Riele, Hein; Kristiansen, Karsten

    2004-01-01

    The differentiation of white and brown fat cells is controlled by a similar set of transcription factors, including PPARgamma and C/EBPalpha. However, despite many similarities between the two types of fat cells, they carry out essentially opposite functions in vivo, with white adipocytes being...... the major energy store and brown adipocytes being potent energy-dissipaters through thermogenesis. Yet, little is known about factors differentially regulating the formation of white and brown fat cells. Members of the retinoblastoma protein family (pRB, p107, p130) have been implicated in the regulation...... of adipocyte differentiation, and expression and phosphorylation of the three retinoblastoma family proteins oscillate in a characteristic manner during differentiation of the white preadipocyte cell line 3T3-L1. We have recently demonstrated a surprising function of the retinoblastoma protein...

  3. Adenosine activates brown adipose tissue and recruits beige adipocytes via A2A receptors

    DEFF Research Database (Denmark)

    Gnad, Thorsten; Scheibler, Saskia; von Kügelgen, Ivar

    2014-01-01

    hamster or rat. However, the role of adenosine in human BAT is unknown. Here we show that adenosine activates human and murine brown adipocytes at low nanomolar concentrations. Adenosine is released in BAT during stimulation of sympathetic nerves as well as from brown adipocytes. The adenosine A2A...... of A2A receptors or injection of lentiviral vectors expressing the A2A receptor into white fat induces brown-like cells-so-called beige adipocytes. Importantly, mice fed a high-fat diet and treated with an A2A agonist are leaner with improved glucose tolerance. Taken together, our results demonstrate...... that adenosine-A2A signalling plays an unexpected physiological role in sympathetic BAT activation and protects mice from diet-induced obesity. Those findings reveal new possibilities for developing novel obesity therapies....

  4. Rapamycin negatively impacts insulin signaling, glucose uptake and uncoupling protein-1 in brown adipocytes.

    Science.gov (United States)

    García-Casarrubios, Ester; de Moura, Carlos; Arroba, Ana I; Pescador, Nuria; Calderon-Dominguez, María; Garcia, Laura; Herrero, Laura; Serra, Dolors; Cadenas, Susana; Reis, Flavio; Carvalho, Eugenia; Obregon, Maria Jesus; Valverde, Ángela M

    2016-12-01

    New onset diabetes after transplantation (NODAT) is a metabolic disorder that affects 40% of patients on immunosuppressive agent (IA) treatment, such as rapamycin (also known as sirolimus). IAs negatively modulate insulin action in peripheral tissues including skeletal muscle, liver and white fat. However, the effects of IAs on insulin sensitivity and thermogenesis in brown adipose tissue (BAT) have not been investigated. We have analyzed the impact of rapamycin on insulin signaling, thermogenic gene-expression and mitochondrial respiration in BAT. Treatment of brown adipocytes with rapamycin for 16h significantly decreased insulin receptor substrate 1 (IRS1) protein expression and insulin-mediated protein kinase B (Akt) phosphorylation. Consequently, both insulin-induced glucose transporter 4 (GLUT4) translocation to the plasma membrane and glucose uptake were decreased. Early activation of the N-terminal Janus activated kinase (JNK) was also observed, thereby increasing IRS1 Ser 307 phosphorylation. These effects of rapamycin on insulin signaling in brown adipocytes were partly prevented by a JNK inhibitor. In vivo treatment of rats with rapamycin for three weeks abolished insulin-mediated Akt phosphorylation in BAT. Rapamycin also inhibited norepinephrine (NE)-induced lipolysis, the expression of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and uncoupling protein (UCP)-1 in brown adipocytes. Importantly, basal mitochondrial respiration, proton leak and maximal respiratory capacity were significantly decreased in brown adipocytes treated with rapamycin. In conclusion, we demonstrate, for the first time the important role of brown adipocytes as target cells of rapamycin, suggesting that insulin resistance in BAT might play a major role in NODAT development.

  5. White-to-brown metabolic conversion of human adipocytes by JAK inhibition

    NARCIS (Netherlands)

    Moisan, A.; Lee, Y. K.; Zhang, J.D.; Hudak, C.S.; Meyer, C.A.; Prummer, M.; Zoffmann, S.; Truong, H.H.; Ebeling, M.; Kiialainen, A.; Gerard, R.; Xia, F.; Schinzel, R.T.; Amrein, K.E.; Cowan, C.A.

    2015-01-01

    The rising incidence of obesity and related disorders such as diabetes and heart disease has focused considerable attention on the discovery of new therapeutics. One promising approach has been to increase the number or activity of brown-like adipocytes in white adipose depots, as this has been

  6. ADD1/SREBP1c activates the PGC1-alpha promoter in brown adipocytes

    DEFF Research Database (Denmark)

    Hao, Qin; Hansen, Jacob B; Petersen, Rasmus K

    2010-01-01

    regulatory element-binding protein-1c (SREBP1c) and peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC1alpha) in brown and inguinal white adipose tissues, but not in epididymal white adipose tissue. Using in vitro models of white and brown adipocytes we demonstrate that beta......-adrenergic stimulation induced expression of LXRalpha, ADD1/SREBP1c and PGC1alpha in cells with a brown-like adipose phenotype. We demonstrate that ADD1/SREBP1c is a powerful inducer of PGC1alpha expression via a conserved E box in the proximal promoter and that beta-adrenergic stimulation led to recruitment of ADD1...

  7. Human multipotent adipose-derived stem cells differentiate into functional brown adipocytes

    DEFF Research Database (Denmark)

    Elabd, Christian; Chiellini, Chiara; Carmona, Mamen

    2009-01-01

    adipose-derived stem (hMADS) cells exhibit a normal karyotype and high self-renewal ability; they are known to differentiate into cells that exhibit the key properties of human white adipocytes, that is, uncoupling protein two expression, insulin-stimulated glucose uptake, lipolysis in response to beta......In contrast to the earlier contention, adult humans have been shown recently to possess active brown adipose tissue with a potential of being of metabolic significance. Up to now, brown fat precursor cells have not been available for human studies. We have shown previously that human multipotent......-agonists and atrial natriuretic peptide, and release of adiponectin and leptin. Herein, we show that, upon chronic exposure to a specific PPARgamma but not to a PPARbeta/delta or a PPARalpha agonist, hMADS cell-derived white adipocytes are able to switch to a brown phenotype by expressing both uncoupling protein one...

  8. Altered miRNA processing disrupts brown/white adipocyte determination and associates with lipodystrophy.

    Science.gov (United States)

    Mori, Marcelo A; Thomou, Thomas; Boucher, Jeremie; Lee, Kevin Y; Lallukka, Susanna; Kim, Jason K; Torriani, Martin; Yki-Järvinen, Hannele; Grinspoon, Steven K; Cypess, Aaron M; Kahn, C Ronald

    2014-08-01

    miRNAs are important regulators of biological processes in many tissues, including the differentiation and function of brown and white adipocytes. The endoribonuclease dicer is a major component of the miRNA-processing pathway, and in adipose tissue, levels of dicer have been shown to decrease with age, increase with caloric restriction, and influence stress resistance. Here, we demonstrated that mice with a fat-specific KO of dicer develop a form of lipodystrophy that is characterized by loss of intra-abdominal and subcutaneous white fat, severe insulin resistance, and enlargement and "whitening" of interscapular brown fat. Additionally, KO of dicer in cultured brown preadipocytes promoted a white adipocyte-like phenotype and reduced expression of several miRNAs. Brown preadipocyte whitening was partially reversed by expression of miR-365, a miRNA known to promote brown fat differentiation; however, introduction of other miRNAs, including miR-346 and miR-362, also contributed to reversal of the loss of the dicer phenotype. Interestingly, fat samples from patients with HIV-related lipodystrophy exhibited a substantial downregulation of dicer mRNA expression. Together, these findings indicate the importance of miRNA processing in white and brown adipose tissue determination and provide a potential link between this process and HIV-related lipodystrophy.

  9. Effects of adipocyte lipoprotein lipase on de novo lipogenesis and white adipose tissue browning.

    Science.gov (United States)

    Bartelt, Alexander; Weigelt, Clara; Cherradi, M Lisa; Niemeier, Andreas; Tödter, Klaus; Heeren, Joerg; Scheja, Ludger

    2013-05-01

    Efficient storage of dietary and endogenous fatty acids is a prerequisite for a healthy adipose tissue function. Lipoprotein lipase (LPL) is the master regulator of fatty acid uptake from triglyceride-rich lipoproteins. In addition to LPL-mediated fatty acid uptake, adipocytes are able to synthesize fatty acids from non-lipid precursor, a process called de novo lipogenesis (DNL). As the physiological relevance of fatty acid uptake versus DNL for brown and white adipocyte function remains unclear, we studied the role of adipocyte LPL using adipocyte-specific LPL knockout animals (aLKO). ALKO mice displayed a profound increase in DNL-fatty acids, especially palmitoleate and myristoleate in brown adipose tissue (BAT) and white adipose tissue (WAT) depots while essential dietary fatty acids were markedly decreased. Consequently, we found increased expression in adipose tissues of genes encoding DNL enzymes (Fasn, Scd1, and Elovl6) as well as the lipogenic transcription factor carbohydrate response element binding protein-β. In a high-fat diet (HFD) study aLKO mice were characterized by reduced adiposity and improved plasma insulin and adipokines. However, neither glucose tolerance nor inflammatory markers were ameliorated in aLKO mice compared to controls. No signs of increased BAT activation or WAT browning were detected in aLKO mice either on HFD or after 1 week of β3-adrenergic stimulation using CL316,243. We conclude that despite a profound increase in DNL-derived fatty acids, proposed to be metabolically favorable, aLKO mice are not protected from metabolic disease per se. In addition, induction of DNL alone is not sufficient to promote browning of WAT. This article is part of a Special Issue entitled Brown and White Fat: From Signaling to Disease.

  10. Chronic peroxisome proliferator-activated receptor gamma (PPARgamma) activation of epididymally derived white adipocyte cultures reveals a population of thermogenically competent, UCP1-containing adipocytes molecularly distinct from classic brown adipocytes

    DEFF Research Database (Denmark)

    Petrovic, Natasa; Walden, Tomas B; Shabalina, Irina G;

    2009-01-01

    The recent insight that brown adipocytes and muscle cells share a common origin and in this respect are distinct from white adipocytes has spurred questions concerning the origin and molecular characteristics of the UCP1-expressing cells observed in classic white adipose tissue depots under certain...

  11. Asc-1, PAT2 and P2RX5 are novel cell surface markers for white, beige and brown adipocytes

    OpenAIRE

    Ussar, Siegfried; Lee, Kevin Y.; Dankel, Simon N.; Boucher, Jeremie; Haering, Max-Felix; Kleinridders, Andre; Thomou, Thomas; Xue, Ruidan; Macotela, Yazmin; Cypess, Aaron M.; Tseng, Yu-Hua; Mellgren, Gunnar; Kahn, C. Ronald

    2014-01-01

    White, beige and brown adipocytes are developmentally and functionally distinct but often occur mixed together within individual depots. To target white, beige and brown adipocytes for diagnostic or therapeutic purposes, a better understanding of the cell surface properties of these cell types is essential. Using a combination of in silico, in vitro and in vivo methods, we have identified three new cell surface markers of adipose cell types. The amino acid transporter Asc-1 is a white adipocy...

  12. Effects of Wnt signaling on brown adipocyte differentiation and metabolism mediated by PGC-1alpha

    DEFF Research Database (Denmark)

    Kang, Sona; Bajnok, Laszlo; Longo, Kenneth A;

    2005-01-01

    expression of PGC-1alpha is required for activation of uncoupling protein 1 (UCP1). Wnt10b blocks brown adipose tissue development and expression of UCP1 when expressed from the fatty acid binding protein 4 promoter, even when mice are administered a beta3-agonist. In differentiated brown adipocytes......Activation of canonical Wnt signaling inhibits brown adipogenesis of cultured cells by impeding induction of PPARgamma and C/EBPalpha. Although enforced expression of these adipogenic transcription factors restores lipid accumulation and expression of FABP4 in Wnt-expressing cells, additional......, activation of Wnt signaling suppresses expression of UCP1 through repression of PGC-1alpha. Consistent with these in vitro observations, UCP1-Wnt10b transgenic mice, which express Wnt10b in interscapular tissue, lack functional brown adipose tissue. While interscapular tissue of UCP1-Wnt10b mice lacks...

  13. Calcium-SANDOZ®-induced erythrocyte exovesiculation and internalization of hemichromic material into rat brown adipocytes

    Directory of Open Access Journals (Sweden)

    Markelić Milica

    2011-01-01

    Full Text Available An ultramicroscopic study of brown adipose tissue (BAT of rats treated with Ca-SANDOZ® (480 mg/l for 3 days, revealed erythrocyte exovesiculation and migratory erythrocytic complexes from the capillaries to adipocyte cytoplasm and mitochondria. Two types of erythrocytic material transfer were observed: (i numerous exocytic vesicles with electron dense material leaving the erythrocytes; (ii furcated complexes with microholes, embedded in amorphous material. The content of red blood cell (RBC complexes passed through the capillaries and transferred to the brown adipocytes where it was detectable in the cytoplasm and mitochondria. Light microscopy confirmed sphenoechinocytic transformation of the RBCs in the blood smears of the Ca-SANDOZ® treated rats.

  14. N-acetylaspartate catabolism determines cytosolic acetyl-CoA levels and histone acetylation in brown adipocytes.

    Science.gov (United States)

    Prokesch, A; Pelzmann, H J; Pessentheiner, A R; Huber, K; Madreiter-Sokolowski, C T; Drougard, A; Schittmayer, M; Kolb, D; Magnes, C; Trausinger, G; Graier, W F; Birner-Gruenberger, R; Pospisilik, J A; Bogner-Strauss, J G

    2016-04-05

    Histone acetylation depends on the abundance of nucleo-cytoplasmic acetyl-CoA. Here, we present a novel route for cytoplasmic acetyl-CoA production in brown adipocytes. N-acetylaspartate (NAA) is a highly abundant brain metabolite catabolized by aspartoacylase yielding aspartate and acetate. The latter can be further used for acetyl-CoA production. Prior to this work, the presence of NAA has not been described in adipocytes. Here, we show that accumulation of NAA decreases the brown adipocyte phenotype. We increased intracellular NAA concentrations in brown adipocytes via media supplementation or knock-down of aspartoacylase and measured reduced lipolysis, thermogenic gene expression, and oxygen consumption. Combinations of approaches to increase intracellular NAA levels showed additive effects on lipolysis and gene repression, nearly abolishing the expression of Ucp1, Cidea, Prdm16, and Ppara. Transcriptome analyses of aspartoacylase knock-down cells indicate deficiencies in acetyl-CoA and lipid metabolism. Concordantly, cytoplasmic acetyl-CoA levels and global histone H3 acetylation were decreased. Further, activating histone marks (H3K27ac and H3K9ac) in promoters/enhancers of brown marker genes showed reduced acetylation status. Taken together, we present a novel route for cytoplasmic acetyl-CoA production in brown adipocytes. Thereby, we mechanistically connect the NAA pathway to the epigenomic regulation of gene expression, modulating the phenotype of brown adipocytes.

  15. Expression of the mitochondrial uncoupling protein in brown adipocytes. Absence in brown preadipocytes and BFC-1 cells. Modulation by isoproterenol in adipocytes.

    Science.gov (United States)

    Forest, C; Doglio, A; Casteilla, L; Ricquier, D; Ailhaud, G

    1987-01-01

    The expression of the uncoupling protein has been compared in cells of BFC-1 clonal line established from mouse brown adipose tissue (BAT) and in preadipocytes, as well as in adipocytes from mouse BAT, both in primary culture. The results of immunoblots show that, after one week in culture, adipocytes have a reduced level of the 32 kD protein. This level can be raised 2-3.5-fold by a 24-h exposure to isoproterenol. Thus a direct modulation by a beta-agonist drug in the expression of the uncoupling protein is observed. Under the same conditions as well as under various other conditions, preadipocytes in primary culture and BFC-1 cells do not express the uncoupling protein. At the same time these cells are able both to differentiate into adipose cells, as demonstrated by the emergence of enzyme markers and triglyceride accumulation, and to respond to isoproterenol. Thus isoproterenol is not sufficient to trigger the expression of the uncoupling protein and behaves as a mere modulator once the cells have acquired the capacity to express it. Injection of undifferentiated BFC-1 cells into athymic mice bearing catecholamine-containing mini-osmotic pumps, or co-cultures of BFC-1 cells and pheochromocytoma PC-12 cells do not allow BFC-1 cells to express the uncoupling protein. Taken together, the results suggest that the formation of brown preadipocytes is critically linked during development to the release by sympathetic nerves of specific trophic factors acting locally.

  16. Fat accumulation in differentiated brown adipocytes is linked with expression of Hox genes.

    Science.gov (United States)

    Singh, Smita; Rajput, Yudhishthir S; Barui, Amit K; Sharma, Rajan; Datta, Tirtha K

    2016-03-01

    Homeobox (Hox) genes are involved in body plan of embryo along the anterior-posterior axis. Presence of several Hox genes in white adipose tissue (WAT) and brown adipose tissue (BAT) is indicative of involvement of Hox genes in adipogenesis. We propose that differentiation inducing agents viz. isobutyl-methyl-xanthine (IBMX), indomethacin, dexamethasone (DEX), triiodothyronine (T3) and insulin may regulate differentiation in brown adipose tissue through Hox genes. In vitro culture of brown fat stromalvascular fraction (SVF) in presence or absence of differentiation inducing agents was used for establishing relationship between fat accumulation in differentiated adipocytes and expression of Hox genes. Relative expression of Pref1, UCP1 and Hox genes was determined in different stages of adipogenesis. Presence or absence of IBMX, indomethacin and DEX during differentiation of proliferated pre-adipocytes resulted in marked differences in expression of Hox genes and lipid accumulation. In presence of these inducing agents, lipid accumulation as well as expression of HoxA1, HoxA5, HoxC4 &HoxC8 markedly enhanced. Irrespective of presence or absence of T3, insulin down regulates HoxA10. T3 results in over expression of HoxA5, HoxC4 and HoxC8 genes, whereas insulin up regulates expression of only HoxC8. Findings suggest that accumulation of fat in differentiated adipocytes is linked with expression of Hox genes.

  17. Noradrenaline represses PPAR (peroxisome-proliferator-activated receptor) gamma2 gene expression in brown adipocytes: intracellular signalling and effects on PPARgamma2 and PPARgamma1 protein levels

    DEFF Research Database (Denmark)

    Lindgren, Eva M; Nielsen, Ronni; Petrovic, Natasa

    2004-01-01

    PPAR (peroxisome-proliferator-activated receptor) gamma is expressed in brown and white adipose tissues and is involved in the control of differentiation and proliferation. Noradrenaline stimulates brown pre-adipocyte proliferation and brown adipocyte differentiation. The aim of the present study...

  18. Enhancement of Adipocyte Browning by Angiotensin II Type 1 Receptor Blockade

    Science.gov (United States)

    Tsukuda, Kana; Mogi, Masaki; Iwanami, Jun; Kanno, Harumi; Nakaoka, Hirotomo; Wang, Xiao-Li; Bai, Hui-Yu; Shan, Bao-Shuai; Kukida, Masayoshi; Higaki, Akinori; Yamauchi, Toshifumi; Min, Li-Juan; Horiuchi, Masatsugu

    2016-01-01

    Browning of white adipose tissue (WAT) has been highlighted as a new possible therapeutic target for obesity, diabetes and lipid metabolic disorders, because WAT browning could increase energy expenditure and reduce adiposity. The new clusters of adipocytes that emerge with WAT browning have been named ‘beige’ or ‘brite’ adipocytes. Recent reports have indicated that the renin-angiotensin system (RAS) plays a role in various aspects of adipose tissue physiology and dysfunction. The biological effects of angiotensin II, a major component of RAS, are mediated by two receptor subtypes, angiotensin II type 1 receptor (AT1R) and type 2 receptor (AT2R). However, the functional roles of angiotensin II receptor subtypes in WAT browning have not been defined. Therefore, we examined whether deletion of angiotensin II receptor subtypes (AT1aR and AT2R) may affect white-to-beige fat conversion in vivo. AT1a receptor knockout (AT1aKO) mice exhibited increased appearance of multilocular lipid droplets and upregulation of thermogenic gene expression in inguinal white adipose tissue (iWAT) compared to wild-type (WT) mice. AT2 receptor-deleted mice did not show miniaturization of lipid droplets or alteration of thermogenic gene expression levels in iWAT. An in vitro experiment using adipose tissue-derived stem cells showed that deletion of the AT1a receptor resulted in suppression of adipocyte differentiation, with reduction in expression of thermogenic genes. These results indicate that deletion of the AT1a receptor might have some effects on the process of browning of WAT and that blockade of the AT1 receptor could be a therapeutic target for the treatment of metabolic disorders. PMID:27992452

  19. Evidence for a direct effect of melatonin on mitochondrial genome expression of Siberian hamster brown adipocytes.

    Science.gov (United States)

    Prunet-Marcassus, B; Ambid, L; Viguerie-Bascands, N; Pénicaud, L; Casteilla, L

    2001-03-01

    Photoperiod variations are known to participate in the regulation of energy balance in different rodent species via melatonin, a neurosecretory product synthesized by the pineal gland during the night. A direct effect of melatonin on adipose tissue has been suggested since binding sites for the indole have been described on brown adipocytes. The aim of this study was to investigate a genetic effect of melatonin on isolated Siberian hamster brown adipocytes using differential display RT-PCR (DDRT-PCR). Brown adipose cells were isolated from brown adipose tissue and treated for 3 hr with 0.1 and 10 microM melatonin. Total RNA was extracted and DDRT-PCR experiments were performed. A differential band, which disappeared after melatonin treatment, was detected. After confirmation and cloning, the corresponding cDNA fragment B18 was sequenced. B18 had 85 and 81% similarity with a portion of rat and mouse cytochrome b mRNA, respectively, suggesting that B18 corresponds to hamster cytochrome b. This hypothesis was confirmed by the close parallel between the changes in mRNA content, detected by B18, and by cytochrome b mRNA content, detected by a rat probe. Cytochrome b mRNA is encoded by the mitochondrial genome, suggesting a similar effect of melatonin on the whole mitochondrial transcripts. Indeed, 3 hr of treatment with melatonin (10 nM and 0.1 microM) decreased by 44% mitochondrial transcript contents. This work constitutes the first evidence of a direct biological effect of melatonin on Siberian hamster brown adipocytes.

  20. UCP1 induction during recruitment of brown adipocytes in white adipose tissue is dependent on cyclooxygenase activity

    DEFF Research Database (Denmark)

    Madsen, Lise; Pedersen, Lone M; Lillefosse, Haldis Haukaas;

    2010-01-01

    -adrenergic induction of UCP1 expression in primary inguinal adipocytes. The use of PGE(2) receptor antagonists implicated EP(4) as a main PGE(2) receptor, and injection of the stable PGE(2) analog (EP(3/4) agonist) 16,16 dm PGE(2) induced UCP1 expression in inguinal white adipose tissue. Inhibition of COX activity......BACKGROUND: The uncoupling protein 1 (UCP1) is a hallmark of brown adipocytes and pivotal for cold- and diet-induced thermogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that cyclooxygenase (COX) activity and prostaglandin E(2) (PGE(2)) are crucially involved in induction of UCP1...... expression in inguinal white adipocytes, but not in classic interscapular brown adipocytes. Cold-induced expression of UCP1 in inguinal white adipocytes was repressed in COX2 knockout (KO) mice and by administration of the COX inhibitor indomethacin in wild-type mice. Indomethacin repressed beta...

  1. Inflammation Downregulates UCP1 Expression in Brown Adipocytes Potentially via SIRT1 and DBC1 Interaction

    Directory of Open Access Journals (Sweden)

    Mark K. Nøhr

    2017-05-01

    Full Text Available Brown adipose tissue thermogenesis at the cost of energy is not only important for the development of obesity, but also possesses great promise in anti-obesity treatment. Uncoupling protein 1 (UCP1 expression has been reported to be under control of the intracellular deacetylase SIRT1. Here, we investigated the effect and mechanism of inflammation and sirtuin-1 (SIRT1 activation on the induction of thermogenic genes in immortalized brown adipocytes incubated with LPS or IL1β and mice with elevated inflammatory tone. In vitro stimulation of brown adipocytes with dibutyryl cyclic adenosine monophosthate (dbcAMP reduced the expression of deleted in breast cancer-1 (Dbc1 (SIRT1 inhibitor and increased the Ucp1 expression. Silencing of SIRT1 attenuated dbcAMP induction of Ucp1. In contrast, IL1β increased the expression of Dbc1 and greatly reduced the induction of Ucp1. Similarly, in vivo studies revealed decreased expression of Ucp1 in brown adipose tissue (BAT in mice chronically infused with LPS. Resveratrol, a known SIRT1 activator, partly rescued the Ucp1 downregulation by inflammation in both the cell cultures and mice. Here, we describe how the expression of Ucp1 in BAT is controlled via SIRT1 and is reduced under inflammation and can be rescued by SIRT1 activation by resveratrol. We suggest the reduced UCP1 expression under inflammation is mediated by the increased expression of DBC1, which inhibits SIRT1 activity.

  2. Inflammation Downregulates UCP1 Expression in Brown Adipocytes Potentially via SIRT1 and DBC1 Interaction.

    Science.gov (United States)

    Nøhr, Mark K; Bobba, Natalia; Richelsen, Bjørn; Lund, Sten; Pedersen, Steen B

    2017-05-08

    Brown adipose tissue thermogenesis at the cost of energy is not only important for the development of obesity, but also possesses great promise in anti-obesity treatment. Uncoupling protein 1 (UCP1) expression has been reported to be under control of the intracellular deacetylase SIRT1. Here, we investigated the effect and mechanism of inflammation and sirtuin-1 (SIRT1) activation on the induction of thermogenic genes in immortalized brown adipocytes incubated with LPS or IL1β and mice with elevated inflammatory tone. In vitro stimulation of brown adipocytes with dibutyryl cyclic adenosine monophosthate (dbcAMP) reduced the expression of deleted in breast cancer-1 (Dbc1) (SIRT1 inhibitor) and increased the Ucp1 expression. Silencing of SIRT1 attenuated dbcAMP induction of Ucp1. In contrast, IL1β increased the expression of Dbc1 and greatly reduced the induction of Ucp1. Similarly, in vivo studies revealed decreased expression of Ucp1 in brown adipose tissue (BAT) in mice chronically infused with LPS. Resveratrol, a known SIRT1 activator, partly rescued the Ucp1 downregulation by inflammation in both the cell cultures and mice. Here, we describe how the expression of Ucp1 in BAT is controlled via SIRT1 and is reduced under inflammation and can be rescued by SIRT1 activation by resveratrol. We suggest the reduced UCP1 expression under inflammation is mediated by the increased expression of DBC1, which inhibits SIRT1 activity.

  3. Carnitine Palmitoyltransferase 1 Increases Lipolysis, UCP1 Protein Expression and Mitochondrial Activity in Brown Adipocytes

    Science.gov (United States)

    Calderon-Dominguez, María; Sebastián, David; Fucho, Raquel; Weber, Minéia; Mir, Joan F.; García-Casarrubios, Ester; Obregón, María Jesús; Zorzano, Antonio; Valverde, Ángela M.; Serra, Dolors

    2016-01-01

    The discovery of active brown adipose tissue (BAT) in adult humans and the fact that it is reduced in obese and diabetic patients have put a spotlight on this tissue as a key player in obesity-induced metabolic disorders. BAT regulates energy expenditure through thermogenesis; therefore, harnessing its thermogenic fat-burning power is an attractive therapeutic approach. We aimed to enhance BAT thermogenesis by increasing its fatty acid oxidation (FAO) rate. Thus, we expressed carnitine palmitoyltransferase 1AM (CPT1AM), a permanently active mutant form of CPT1A (the rate-limiting enzyme in FAO), in a rat brown adipocyte (rBA) cell line through adenoviral infection. We found that CPT1AM-expressing rBA have increased FAO, lipolysis, UCP1 protein levels and mitochondrial activity. Additionally, enhanced FAO reduced the palmitate-induced increase in triglyceride content and the expression of obese and inflammatory markers. Thus, CPT1AM-expressing rBA had enhanced fat-burning capacity and improved lipid-induced derangements. This indicates that CPT1AM-mediated increase in brown adipocytes FAO may be a new approach to the treatment of obesity-induced disorders. PMID:27438137

  4. Berardinelli-Seip congenital lipodystrophy 2 regulates adipocyte lipolysis, browning, and energy balance in adult animals.

    Science.gov (United States)

    Zhou, Hongyi; Lei, Xinnuo; Benson, Tyler; Mintz, James; Xu, Xiaojing; Harris, Ruth B; Weintraub, Neal L; Wang, Xiaoling; Chen, Weiqin

    2015-10-01

    Mutations in BSCL2/SEIPIN cause Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2), but the mechanisms whereby Bscl2 regulates adipose tissue function are unclear. Here, we generated adipose tissue (mature) Bscl2 knockout (Ad-mKO) mice, in which Bscl2 was specifically ablated in adipocytes of adult animals, to investigate the impact of acquired Bscl2 deletion on adipose tissue function and energy balance. Ad-mKO mice displayed reduced adiposity and were protected against high fat diet-induced obesity, but not insulin resistance or hepatic steatosis. Gene expression profiling and biochemical assays revealed increased lipolysis and fatty acid oxidation in white adipose tissue (WAT) and brown adipose tissue , as well as browning of WAT, owing to induction of cAMP/protein kinase A signaling upon Bscl2 deletion. Interestingly, Bscl2 deletion reduced food intake and downregulated adipose β3-adrenergic receptor (ADRB3) expression. Impaired ADRB3 signaling partially offsets upregulated browning-induced energy expenditure and thermogenesis in Ad-mKO mice housed at ambient temperature. However, this counter-regulatory response was abrogated under thermoneutral conditions, resulting in even greater body mass loss in Ad-mKO mice. These findings suggest that Bscl2 regulates adipocyte lipolysis and β-adrenergic signaling to produce complex effects on adipose tissues and whole-body energy balance. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  5. Carnitine Palmitoyltransferase 1 Increases Lipolysis, UCP1 Protein Expression and Mitochondrial Activity in Brown Adipocytes.

    Directory of Open Access Journals (Sweden)

    María Calderon-Dominguez

    Full Text Available The discovery of active brown adipose tissue (BAT in adult humans and the fact that it is reduced in obese and diabetic patients have put a spotlight on this tissue as a key player in obesity-induced metabolic disorders. BAT regulates energy expenditure through thermogenesis; therefore, harnessing its thermogenic fat-burning power is an attractive therapeutic approach. We aimed to enhance BAT thermogenesis by increasing its fatty acid oxidation (FAO rate. Thus, we expressed carnitine palmitoyltransferase 1AM (CPT1AM, a permanently active mutant form of CPT1A (the rate-limiting enzyme in FAO, in a rat brown adipocyte (rBA cell line through adenoviral infection. We found that CPT1AM-expressing rBA have increased FAO, lipolysis, UCP1 protein levels and mitochondrial activity. Additionally, enhanced FAO reduced the palmitate-induced increase in triglyceride content and the expression of obese and inflammatory markers. Thus, CPT1AM-expressing rBA had enhanced fat-burning capacity and improved lipid-induced derangements. This indicates that CPT1AM-mediated increase in brown adipocytes FAO may be a new approach to the treatment of obesity-induced disorders.

  6. Carnitine Palmitoyltransferase 1 Increases Lipolysis, UCP1 Protein Expression and Mitochondrial Activity in Brown Adipocytes.

    Science.gov (United States)

    Calderon-Dominguez, María; Sebastián, David; Fucho, Raquel; Weber, Minéia; Mir, Joan F; García-Casarrubios, Ester; Obregón, María Jesús; Zorzano, Antonio; Valverde, Ángela M; Serra, Dolors; Herrero, Laura

    2016-01-01

    The discovery of active brown adipose tissue (BAT) in adult humans and the fact that it is reduced in obese and diabetic patients have put a spotlight on this tissue as a key player in obesity-induced metabolic disorders. BAT regulates energy expenditure through thermogenesis; therefore, harnessing its thermogenic fat-burning power is an attractive therapeutic approach. We aimed to enhance BAT thermogenesis by increasing its fatty acid oxidation (FAO) rate. Thus, we expressed carnitine palmitoyltransferase 1AM (CPT1AM), a permanently active mutant form of CPT1A (the rate-limiting enzyme in FAO), in a rat brown adipocyte (rBA) cell line through adenoviral infection. We found that CPT1AM-expressing rBA have increased FAO, lipolysis, UCP1 protein levels and mitochondrial activity. Additionally, enhanced FAO reduced the palmitate-induced increase in triglyceride content and the expression of obese and inflammatory markers. Thus, CPT1AM-expressing rBA had enhanced fat-burning capacity and improved lipid-induced derangements. This indicates that CPT1AM-mediated increase in brown adipocytes FAO may be a new approach to the treatment of obesity-induced disorders.

  7. Regulation of Brown and White Adipocyte Transcriptome by the Transcriptional Coactivator NT-PGC-1α.

    Science.gov (United States)

    Kim, Jihyun; Fernand, Vivian E; Henagan, Tara M; Shin, Jeho; Huypens, Peter; Newman, Susan; Gettys, Thomas W; Chang, Ji Suk

    2016-01-01

    The β3-adrenergic receptor (AR) signaling pathway is a major component of adaptive thermogenesis in brown and white adipose tissue during cold acclimation. The β3-AR signaling highly induces the expression of transcriptional coactivator PGC-1α and its splice variant N-terminal (NT)-PGC-1α, which in turn activate the transcription program of adaptive thermogenesis by co-activating a number of transcription factors. We previously reported that NT-PGC-1α is able to increase mitochondrial number and activity in cultured brown adipocytes by promoting the expression of mitochondrial and thermogenic genes. In the present study, we performed genome-wide profiling of NT-PGC-1α-responsive genes in brown adipocytes to identify genes potentially regulated by NT-PGC-1α. Canonical pathway analysis revealed that a number of genes upregulated by NT-PGC-1α are highly enriched in mitochondrial pathways including fatty acid transport and β-oxidation, TCA cycle and electron transport system, thus reinforcing the crucial role of NT-PGC-1α in the enhancement of mitochondrial function. Moreover, canonical pathway analysis of NT-PGC-1α-responsive genes identified several metabolic pathways including glycolysis and fatty acid synthesis. In order to validate the identified genes in vivo, we utilized the FL-PGC-1α-/- mouse that is deficient in full-length PGC-1α (FL-PGC-1α) but expresses a slightly shorter and functionally equivalent form of NT-PGC-1α (NT-PGC-1α254). The β3-AR-induced increase of NT-PGC-1α254 in FL-PGC-1α-/- brown and white adipose tissue was closely associated with elevated expression of genes involved in thermogenesis, mitochondrial oxidative metabolism, glycolysis and fatty acid synthesis. Increased adipose tissue thermogenesis by β3-AR activation resulted in attenuation of adipose tissue expansion in FL-PGC-1α-/- adipose tissue under the high-fat diet condition. Together, the data strengthen our previous findings that NT-PGC-1α regulates

  8. Regulation of Brown and White Adipocyte Transcriptome by the Transcriptional Coactivator NT-PGC-1α.

    Directory of Open Access Journals (Sweden)

    Jihyun Kim

    Full Text Available The β3-adrenergic receptor (AR signaling pathway is a major component of adaptive thermogenesis in brown and white adipose tissue during cold acclimation. The β3-AR signaling highly induces the expression of transcriptional coactivator PGC-1α and its splice variant N-terminal (NT-PGC-1α, which in turn activate the transcription program of adaptive thermogenesis by co-activating a number of transcription factors. We previously reported that NT-PGC-1α is able to increase mitochondrial number and activity in cultured brown adipocytes by promoting the expression of mitochondrial and thermogenic genes. In the present study, we performed genome-wide profiling of NT-PGC-1α-responsive genes in brown adipocytes to identify genes potentially regulated by NT-PGC-1α. Canonical pathway analysis revealed that a number of genes upregulated by NT-PGC-1α are highly enriched in mitochondrial pathways including fatty acid transport and β-oxidation, TCA cycle and electron transport system, thus reinforcing the crucial role of NT-PGC-1α in the enhancement of mitochondrial function. Moreover, canonical pathway analysis of NT-PGC-1α-responsive genes identified several metabolic pathways including glycolysis and fatty acid synthesis. In order to validate the identified genes in vivo, we utilized the FL-PGC-1α-/- mouse that is deficient in full-length PGC-1α (FL-PGC-1α but expresses a slightly shorter and functionally equivalent form of NT-PGC-1α (NT-PGC-1α254. The β3-AR-induced increase of NT-PGC-1α254 in FL-PGC-1α-/- brown and white adipose tissue was closely associated with elevated expression of genes involved in thermogenesis, mitochondrial oxidative metabolism, glycolysis and fatty acid synthesis. Increased adipose tissue thermogenesis by β3-AR activation resulted in attenuation of adipose tissue expansion in FL-PGC-1α-/- adipose tissue under the high-fat diet condition. Together, the data strengthen our previous findings that NT-PGC-1

  9. Genome-wide profiling of peroxisome proliferator-activated receptor γ in primary epididymal, inguinal, and brown adipocytes reveals depot-selective binding correlated with gene expression

    DEFF Research Database (Denmark)

    Siersbæk, Majken; Loft, Anne; Jørgensen, Mads Malik Aagaard

    2012-01-01

    Peroxisome proliferator-activated receptor γ (PPARγ) is a master regulator of adipocyte differentiation and function. We and others have previously mapped PPARγ binding at a genome-wide level in murine and human adipocyte cell lines and in primary human adipocytes. However, little is known about...... how binding patterns of PPARγ differ between brown and white adipocytes and among different types of white adipocytes. Here we have employed chromatin immunoprecipitation combined with deep sequencing to map and compare PPARγ binding in in vitro differentiated primary mouse adipocytes isolated from...... epididymal, inguinal, and brown adipose tissues. While these PPARγ binding profiles are overall similar, there are clear depot-selective binding sites. Most PPARγ binding sites previously mapped in 3T3-L1 adipocytes can also be detected in primary adipocytes, but there are a large number of PPARγ binding...

  10. A-FABP mediates adaptive thermogenesis by promoting intracellular activation of thyroid hormones in brown adipocytes

    Science.gov (United States)

    Shu, Lingling; Hoo, Ruby L. C.; Wu, Xiaoping; Pan, Yong; Lee, Ida P. C.; Cheong, Lai Yee; Bornstein, Stefan R; Rong, Xianglu; Guo, Jiao; Xu, Aimin

    2017-01-01

    The adipokine adipocyte fatty acid-binding protein (A-FABP) has been implicated in obesity-related cardio-metabolic complications. Here we show that A-FABP increases thermogenesis by promoting the conversion of T4 to T3 in brown adipocytes. We find that A-FABP levels are increased in both white (WAT) and brown (BAT) adipose tissues and the bloodstream in response to thermogenic stimuli. A-FABP knockout mice have reduced thermogenesis and whole-body energy expenditure after cold stress or after feeding a high-fat diet, which can be reversed by infusion of recombinant A-FABP. Mechanistically, A-FABP induces the expression of type-II iodothyronine deiodinase in BAT via inhibition of the nuclear receptor liver X receptor α, thereby leading to the conversion of thyroid hormone from its inactive form T4 to active T3. The thermogenic responses to T4 are abrogated in A-FABP KO mice, but enhanced by A-FABP. Thus, A-FABP acts as a physiological stimulator of BAT-mediated adaptive thermogenesis. PMID:28128199

  11. Inhibition of mouse brown adipocyte differentiation by second-generation antipsychotics.

    Science.gov (United States)

    Oh, Jee-Eun; Cho, Yoon Mi; Kwak, Su-Nam; Kim, Jae-Hyun; Lee, Kyung Won; Jung, Hyosan; Jeong, Seong-Whan; Kwon, Oh-Joo

    2012-09-30

    Brown adipose tissue is specialized to burn lipids for thermogenesis and energy expenditure. Second-generation antipsychotics (SGA) are the most commonly used drugs for schizophrenia with several advantages over first-line drugs, however, it can cause clinically-significant weight gain. To reveal the involvement of brown adipocytes in SGA-induced weight gain, we compared the effect of clozapine, quetiapine, and ziprasidone, SGA with different propensities to induce weight gain, on the differentiation and the expression of brown fat-specific markers, lipogenic genes and adipokines in a mouse brown preadipocyte cell line. On Oil Red-O staining, the differentiation was inhibited almost completely by clozapine (40 μM) and partially by quetiapine (30 μM). Clozapine significantly down-regulated the brown adipogenesis markers PRDM16, C/EBPβ, PPARγ2, UCP-1, PGC-1α, and Cidea in dose- and time-dependent manners, whereas quetiapine suppressed PRDM16, PPARγ 2, and UCP-1 much weakly than clozapine. Clozapine also significantly inhibited the mRNA expressions of lipogenic genes ACC, SCD1, GLUT4, aP2, and CD36 as well as adipokines such as resistin, leptin, and adiponectin. In contrast, quetiapine suppressed only resistin and leptin but not those of lipogenic genes and adiponectin. Ziprasidone (10 μM) did not alter the differentiation as well as the gene expression patterns. Our results suggest for the first time that the inhibition of brown adipogenesis may be a possible mechanism to explain weight gain induced by clozapine and quetiapine.

  12. Increased Mitochondrial Activity in BMP7-Treated Brown Adipocytes, Due to Increased CPT1- and CD36-Mediated Fatty Acid Uptake

    OpenAIRE

    Townsend, Kristy L; An, Ding; Lynes, Matthew D.; Huang, Tian Lian; Zhang, Hongbin; Goodyear, Laurie J.; Tseng, Yu-Hua

    2013-01-01

    Aims: Brown adipose tissue dissipates chemical energy in the form of heat and regulates triglyceride and glucose metabolism in the body. Factors that regulate fatty acid uptake and oxidation in brown adipocytes have not yet been fully elucidated. Bone morphogenetic protein 7 (BMP7) is a growth factor capable of inducing brown fat mitochondrial biogenesis during differentiation from adipocyte progenitors. Administration of BMP7 to mice also results in increased energy expenditure. To determine...

  13. Calcium-induced alteration of mitochondrial morphology and mitochondrial-endoplasmic reticulum contacts in rat brown adipocytes

    Directory of Open Access Journals (Sweden)

    I. Golic

    2014-09-01

    Full Text Available Mitochondria are key organelles maintaining cellular bioenergetics and integrity, and their regulation of [Ca2+]i homeostasis has been investigated in many cell types. We investigated the short-term Ca-SANDOZ® treatment on brown adipocyte mitochondria, using imaging and molecular biology techniques. Two-month-old male Wistar rats were divided into two groups: Ca-SANDOZ® drinking or tap water (control drinking for three days. Alizarin Red S staining showed increased Ca2+ level in the brown adipocytes of treated rats, and potassium pyroantimonate staining localized electron-dense regions in the cytoplasm, mitochondria and around lipid droplets. Ca-SANDOZ® decreased mitochondrial number, but increased their size and mitochondrial cristae volume. Transmission electron microscopy revealed numerous enlarged and fusioned-like mitochondria in the Ca-SANDOZ® treated group compared to the control, and megamitochondria in some brown adipocytes. The Ca2+ diet affected mitochondrial fusion as mitofusin 1 (MFN1 and mitofusin 2 (MFN2 were increased, and mitochondrial fission as dynamin related protein 1 (DRP1 was decreased. Confocal microscopy showed a higher colocalization rate between functional mitochondria and endoplasmic reticulum (ER. The level of uncoupling protein-1 (UCP1 was elevated, which was confirmed by immunohistochemistry and Western blot analysis. These results suggest that Ca-SANDOZ® stimulates mitochondrial fusion, increases mitochondrial-ER contacts and the thermogenic capacity of brown adipocytes

  14. Calcium-induced alteration of mitochondrial morphology and mitochondrial-endoplasmic reticulum contacts in rat brown adipocytes.

    Science.gov (United States)

    Golic, I; Velickovic, K; Markelic, M; Stancic, A; Jankovic, A; Vucetic, M; Otasevic, V; Buzadzic, B; Korac, B; Korac, A

    2014-09-09

    Mitochondria are key organelles maintaining cellular bioenergetics and integrity, and their regulation of [Ca2+]i homeostasis has been investigated in many cell types. We investigated the short-term Ca-SANDOZ® treatment on brown adipocyte mitochondria, using imaging and molecular biology techniques. Two-month-old male Wistar rats were divided into two groups: Ca-SANDOZ® drinking or tap water (control) drinking for three days. Alizarin Red S staining showed increased Ca2+ level in the brown adipocytes of treated rats, and potassium pyroantimonate staining localized electron-dense regions in the cytoplasm, mitochondria and around lipid droplets. Ca-SANDOZ® decreased mitochondrial number, but increased their size and mitochondrial cristae volume. Transmission electron microscopy revealed numerous enlarged and fusioned-like mitochondria in the Ca-SANDOZ® treated group compared to the control, and megamitochondria in some brown adipocytes. The Ca2+ diet affected mitochondrial fusion as mitofusin 1 (MFN1) and mitofusin 2 (MFN2) were increased, and mitochondrial fission as dynamin related protein 1 (DRP1) was decreased. Confocal microscopy showed a higher colocalization rate between functional mitochondria and endoplasmic reticulum (ER). The level of uncoupling protein-1 (UCP1) was elevated, which was confirmed by immunohistochemistry and Western blot analysis. These results suggest that Ca-SANDOZ® stimulates mitochondrial fusion, increases mitochondrial-ER contacts and the thermogenic capacity of brown adipocytes.

  15. Short-Chain Fatty Acid Acetate Stimulates Adipogenesis and Mitochondrial Biogenesis via GPR43 in Brown Adipocytes.

    Science.gov (United States)

    Hu, Jiamiao; Kyrou, Ioannis; Tan, Bee K; Dimitriadis, Georgios K; Ramanjaneya, Manjunath; Tripathi, Gyanendra; Patel, Vanlata; James, Sean; Kawan, Mohamed; Chen, Jing; Randeva, Harpal S

    2016-05-01

    Short-chain fatty acids play crucial roles in a range of physiological functions. However, the effects of short-chain fatty acids on brown adipose tissue have not been fully investigated. We examined the role of acetate, a short-chain fatty acid formed by fermentation in the gut, in the regulation of brown adipocyte metabolism. Our results show that acetate up-regulates adipocyte protein 2, peroxisomal proliferator-activated receptor-γ coactivator-1α, and uncoupling protein-1 expression and affects the morphological changes of brown adipocytes during adipogenesis. Moreover, an increase in mitochondrial biogenesis was observed after acetate treatment. Acetate also elicited the activation of ERK and cAMP response element-binding protein, and these responses were sensitive to G(i/o)-type G protein inactivator, Gβγ-subunit inhibitor, phospholipase C inhibitor, and MAPK kinase inhibitor, indicating a role for the G(i/o)βγ/phospholipase C/protein kinase C/MAPK kinase signaling pathway in these responses. These effects of acetate were mimicked by treatment with 4-chloro-α-(1-methylethyl)-N-2-thiazolylbenzeneacetamide, a synthetic G protein-coupled receptor 43 (GPR43) agonist and were impaired in GPR43 knockdown cells. Taken together, our results indicate that acetate may have important physiological roles in brown adipocytes through the activation of GPR43.

  16. Brown Algae Polyphenol, a Prolyl Isomerase Pin1 Inhibitor, Prevents Obesity by Inhibiting the Differentiation of Stem Cells into Adipocytes

    Science.gov (United States)

    Suzuki, Atsuko; Saeki, Toshiyuki; Ikuji, Hiroko; Uchida, Chiyoko; Uchida, Takafumi

    2016-01-01

    Background While screening for an inhibitor of the peptidyl prolyl cis/trans isomerase, Pin1, we came across a brown algae polyphenol that blocks the differentiation of fibroblasts into adipocytes. However, its effectiveness on the accumulation of fat in the body has never been studied. Methodology/Principal Findings Oral administration of brown algae polyphenol to mice fed with a high fat diet, suppressed the increase in fat volume to a level observed in mice fed with a normal diet. We speculate that Pin1 might be required for the differentiation of stem cell to adipocytes. We established wild type (WT) and Pin1-/- (Pin1-KO) adipose-derived mesenchymal stem cell (ASC) lines and found that WT ASCs differentiate to adipocytes but Pin1-KO ASCs do not. Conclusion and Significance Oral administration of brown algae polyphenol, a Pin1 inhibitor, reduced fat buildup in mice. We showed that Pin1 is required for the differentiation of stem cells into adipocytes. We propose that oral intake of brown algae polyphenol is useful for the treatment of obesity. PMID:28036348

  17. Taking control over intracellular fatty acid levels is essential for the analysis of thermogenic function in cultured primary brown and brite/beige adipocytes.

    Science.gov (United States)

    Li, Yongguo; Fromme, Tobias; Schweizer, Sabine; Schöttl, Theresa; Klingenspor, Martin

    2014-10-01

    Thermogenesis in brown adipocytes, conferred by mitochondrial uncoupling protein 1 (UCP1), is receiving great attention because metabolically active brown adipose tissue may protect humans from metabolic diseases. In particular, the thermogenic function of brown-like adipocytes in white adipose tissue, known as brite (or beige) adipocytes, is currently of prime interest. A valid procedure to quantify the specific contribution of UCP1 to thermogenesis is thus of vital importance. Adrenergic stimulation of lipolysis is a common way to activate UCP1. We here report, however, that in this frequently applied setup, taking control over intracellular fatty acid levels is essential for the analysis of thermogenic function in cultured brown and brite adipocytes. By the application of these findings, we demonstrate that UCP1 is functionally thermogenic in intact brite adipocytes and adrenergic UCP1 activation is largely dependent on adipose triglyceride lipase (ATGL) rather than hormone sensitive lipase (HSL).

  18. Insulin/IGF-I regulation of necdin and brown adipocyte differentiation via CREB- and FoxO1-associated pathways

    DEFF Research Database (Denmark)

    Cypess, Aaron M; Zhang, Hongbin; Schulz, Tim J

    2011-01-01

    Brown adipose tissue plays an important role in obesity, insulin resistance, and diabetes. We have previously shown that the transition from brown preadipocytes to mature adipocytes is mediated in part by insulin receptor substrate (IRS)-1 and the cell cycle regulator protein necdin. In this study...... with specific consensus sequences in the proximal region. Based on these results, we propose that insulin/IGF-I act through IRS-1 phosphorylation to stimulate differentiation of brown preadipocytes via two complementary pathways: 1) the Ras-ERK1/2 pathway to activate CREB and 2) the phosphoinositide 3 kinase...

  19. Oxygen deprivation and the cellular response to hypoxia in adipocytes - perspectives on white and brown adipose tissues in obesity.

    Science.gov (United States)

    Trayhurn, Paul; Alomar, Suliman Yousef

    2015-01-01

    Relative hypoxia has been shown to develop in white adipose tissue depots of different types of obese mouse (genetic, dietary), and this leads to substantial changes in white adipocyte function. These changes include increased production of inflammation-related adipokines (such as IL-6, leptin, Angptl4, and VEGF), an increase in glucose utilization and lactate production, and the induction of fibrosis and insulin resistance. Whether hypoxia also occurs in brown adipose tissue depots in obesity has been little considered. However, a recent study has reported low pO2 in brown fat of obese mice, this involving mitochondrial loss and dysfunction. We suggest that obesity-linked hypoxia may lead to similar alterations in brown adipocytes as in white fat cells - particularly changes in adipokine production, increased glucose uptake and lactate release, and insulin resistance. This would be expected to compromise thermogenic activity and the role of brown fat in glucose homeostasis and triglyceride clearance, underpinning the development of the metabolic syndrome. Hypoxia-induced augmentation of lactate production may also stimulate the "browning" of white fat depots through recruitment of UCP1 and the development of brite adipocytes.

  20. Beta(3)-adrenergic signaling acutely down regulates adipose triglyceride lipase in brown adipocytes.

    Science.gov (United States)

    Deiuliis, Jeffrey A; Liu, Li-Fen; Belury, Martha A; Rim, Jong S; Shin, Sangsu; Lee, Kichoon

    2010-06-01

    Mice exposed to cold rely upon brown adipose tissue (BAT)-mediated nonshivering thermogenesis to generate body heat using dietary glucose and lipids from the liver and white adipose tissue. In this report, we investigate how cold exposure affects the PI3 K/Akt signaling cascade and the expression of genes involved in lipid metabolism and trafficking in BAT. Cold exposure at an early time point led to the activation of the PI3 K/Akt, insulin-like signaling cascade followed by a transient decrease in adipose triglyceride lipase (ATGL) gene and protein expression in BAT. To further investigate how cold exposure-induced signaling altered ATGL expression, cultured primary brown adipocytes were treated with the beta(3)-adrenergic receptor (beta(3)AR) agonist CL 316,243 (CL) resulting in activation of PI3 K/Akt, ERK 1/2, and p38 signaling pathways and significantly decreased ATGL protein levels. ATGL protein levels decreased significantly 30 min post CL treatment suggesting protein degradation. Inhibition of PKA signaling by H89 rescued ATGL levels. The effects of PKA signaling on ATGL were shown to be independent of relevant pathways downstream of PKA such as PI3 K/Akt, ERK 1/2, and p38. However, CL treatment in 3T3-L1 adipocytes did not decrease ATGL protein and mRNA expression, suggesting a distinct response in WAT to beta3-adrenergic agonism. Transitory effects, possibly attributed to acute Akt activation during the early recruitment phase, were noted as well as stable changes in gene expression which may be attributed to beta3-adrenergic signaling in BAT.

  1. Fatty acid binding protein 4 expression marks a population of adipocyte progenitors in white and brown adipose tissues.

    Science.gov (United States)

    Shan, Tizhong; Liu, Weiyi; Kuang, Shihuan

    2013-01-01

    Adipose tissues regulate metabolism, reproduction, and life span. The development and growth of adipose tissue are due to increases of both adipocyte cell size and cell number; the latter is mediated by adipocyte progenitors. Various markers have been used to identify either adipocyte progenitors or mature adipocytes. The fatty acid binding protein 4 (FABP4), commonly known as adipocyte protein 2 (aP2), has been extensively used as a marker for differentiated adipocytes. However, whether aP2 is expressed in adipogenic progenitors is controversial. Using Cre/LoxP-based cell lineage tracing in mice, we have identified a population of aP2-expressing progenitors in the stromal vascular fraction (SVF) of both white and brown adipose tissues. The aP2-lineage progenitors reside in the adipose stem cell niche and express adipocyte progenitor markers, including CD34, Sca1, Dlk1, and PDGFRα. When isolated and grown in culture, the aP2-expressing SVF cells proliferate and differentiate into adipocytes upon induction. Conversely, ablation of the aP2 lineage greatly reduces the adipogenic potential of SVF cells. When grafted into wild-type mice, the aP2-lineage progenitors give rise to adipose depots in recipient mice. Therefore, the expression of aP2 is not limited to mature adipocytes, but also marks a pool of undifferentiated progenitors associated with the vasculature of adipose tissues. Our finding adds to the repertoire of adipose progenitor markers and points to a new regulator of adipose plasticity.

  2. Transcriptional pathways in cPGI2-induced adipocyte progenitor activation for browning

    Directory of Open Access Journals (Sweden)

    Irem eBayindir

    2015-08-01

    Full Text Available De novo formation of beige/brite adipocytes from progenitor cells contributes to the thermogenic adaptation of adipose tissue and holds great potential for the therapeutic remodeling of fat as a treatment for obesity. Despite the recent identification of several factors regulating browning of white fat, there is a lack of physiological cell models for the mechanistic investigation of progenitor-mediated beige/brite differentiation. We have previously revealed prostacyclin (PGI2 as one of the few known endogenous extracellular mediators promoting de novo beige/brite formation by relaying beta-adrenergic stimulation to the progenitor level. Here we present a cell model based on murine primary progenitor cells defined by markers previously shown to be relevant for in vivo browning, including a simplified isolation procedure. We demonstrate the specific and broad induction of thermogenic gene expression by PGI2 signaling in the absence of lineage conversion, and reveal the previously unidentified nuclear relocalization of the Ucp1 gene locus in association with transcriptional activation. By profiling the time course of the progenitor response we show that PGI2 signaling promoted progenitor cell activation through cell cycle and adhesion pathways prior to metabolic maturation towards an oxidative cell phenotype. Our results highlight the importance of core progenitor activation pathways for the recruitment of thermogenic cells and provide a resource for further mechanistic investigation.

  3. Nixon's "Southern Strategy" and Forces against Brown

    Science.gov (United States)

    Brown, Frank

    2004-01-01

    Richard M. Nixon, the United States President in 1968 gave birth to the modern reform movement through public vouchers and other educational reform measures under his "Southern Strategy" that was designed to gain the votes of individuals who oppose school desegregation. The political activities in school desegregation after Brown by the…

  4. Adipocytes in both brown and white adipose tissue of adult mice are functionally connected via gap junctions: implications for Chagas disease.

    Science.gov (United States)

    Burke, Shoshana; Nagajyothi, Fnu; Thi, Mia M; Hanani, Menachem; Scherer, Philipp E; Tanowitz, Herbert B; Spray, David C

    2014-11-01

    Adipose tissue serves as a host reservoir for the protozoan Trypanosoma cruzi, the causative organism in Chagas disease. Gap junctions interconnect cells of most tissues, serving to synchronize cell activities including secretion in glandular tissue, and we have previously demonstrated that gap junctions are altered in various tissues and cells infected with T. cruzi. Herein, we examined the gap junction protein connexin 43 (Cx43) expression in infected adipose tissues. Adipose tissue is the largest endocrine organ of the body and is also involved in other physiological functions. In mammals, it is primarily composed of white adipocytes. Although gap junctions are a prominent feature of brown adipocytes, they have not been explored extensively in white adipocytes, especially in the setting of infection. Thus, we examined functional coupling in both white and brown adipocytes in mice. Injection of electrical current or the dye Lucifer Yellow into adipocytes within fat tissue spread to adjacent cells, which was reduced by treatment with agents known to block gap junctions. Moreover, Cx43 was detected in both brown and white fat tissue. At thirty and ninety days post-infection, Cx43 was downregulated in brown adipocytes and upregulated in white adipocytes. Gap junction-mediated intercellular communication likely contributes to hormone secretion and other functions in white adipose tissue and to nonshivering thermogenesis in brown fat, and modulation of the coupling by T. cruzi infection is expected to impact these functions. Copyright © 2014. Published by Elsevier Masson SAS.

  5. UCP1 induction during recruitment of brown adipocytes in white adipose tissue is dependent on cyclooxygenase activity

    DEFF Research Database (Denmark)

    Madsen, Lise; Pedersen, Lone M; Lillefosse, Haldis Haukaas

    2010-01-01

    -adrenergic induction of UCP1 expression in primary inguinal adipocytes. The use of PGE(2) receptor antagonists implicated EP(4) as a main PGE(2) receptor, and injection of the stable PGE(2) analog (EP(3/4) agonist) 16,16 dm PGE(2) induced UCP1 expression in inguinal white adipose tissue. Inhibition of COX activity......BACKGROUND: The uncoupling protein 1 (UCP1) is a hallmark of brown adipocytes and pivotal for cold- and diet-induced thermogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that cyclooxygenase (COX) activity and prostaglandin E(2) (PGE(2)) are crucially involved in induction of UCP1...... attenuated diet-induced UCP1 expression and increased energy efficiency and adipose tissue mass in obesity-resistant mice kept at thermoneutrality. CONCLUSIONS/SIGNIFICANCE: Our findings provide evidence that induction of UCP1 expression in white adipose tissue, but not in classic interscapular brown adipose...

  6. Expression of “brown-in-white” adipocyte biomarkers shows gender differences and the influence of early dietary exposure

    OpenAIRE

    Servera, María; López,Nora; Serra, Francisca; Palou, Andreu

    2013-01-01

    Induction of brown-like adipocytes (brite) in white adipose tissues may allow the conversion of lipid storage cells in fat-burning cells. Little is known concerning browning potential in males compared with females. In this study, we aimed to analyse whether gender differences were present in gene expression of “brite” markers as well as the impact of dietary manipulation at both early stages and adulthood in rats. We have determined the expression of brite markers and genes associated with l...

  7. The Molecular Signature of HIV-1-Associated Lipomatosis Reveals Differential Involvement of Brown and Beige/Brite Adipocyte Cell Lineages.

    Directory of Open Access Journals (Sweden)

    Rubén Cereijo

    Full Text Available Highly active antiretroviral therapy has remarkably improved quality of life of HIV-1-infected patients. However, this treatment has been associated with the so-called lipodystrophic syndrome, which conveys a number of adverse metabolic effects and morphological alterations. Among them, lipoatrophy of subcutaneous fat in certain anatomical areas and hypertrophy of visceral depots are the most common. Less frequently, lipomatous enlargements of subcutaneous fat at distinct anatomic areas occur. Lipomatous adipose tissue in the dorso-cervical area ("buffalo hump" has been associated with a partial white-to-brown phenotype transition and with increased cell proliferation, but, to date, lipomatous enlargements arising in other parts of the body have not been characterized. In order to establish the main molecular events associated with the appearance of lipomatosis in HIV-1 patients, we analyzed biopsies of lipomatous tissue from "buffalo hump" and from other anatomical areas in patients, in comparison with healthy subcutaneous adipose tissue, using a marker gene expression approach. Both buffalo-hump and non-buffalo-hump lipomatous adipose tissues exhibited similar patterns of non-compromised adipogenesis, unaltered inflammation, non-fibrotic phenotype and proliferative activity. Shorter telomere length, prelamin A accumulation and SA-β-Gal induction, reminiscent of adipocyte senescence, were also common to both types of lipomatous tissues. Buffalo hump biopsies showed expression of marker genes of brown adipose tissue (e.g. UCP1 and, specifically, of "classical" brown adipocytes (e.g. ZIC1 but not of beige/brite adipocytes. No such brown fat-related gene expression occurred in lipomatous tissues at other anatomical sites. In conclusion, buffalo hump and other subcutaneous adipose tissue enlargements from HIV-1-infected patients share a similar lipomatous character. However, a distorted induction of white-to-"classical brown adipocyte" phenotype

  8. Effects of vitamin a status on expression of ucp1 and brown/beige adipocyte-related genes in white adipose tissues of beef cattle.

    Science.gov (United States)

    Kanamori, Yohei; Yamada, Tomoya; Asano, Hiroki; Kida, Ryosuke; Qiao, Yuhang; Abd Eldaim, Mabrouk A; Tomonaga, Shozo; Matsui, Tohru; Funaba, Masayuki

    2014-09-01

    We previously reported the presence of brown/beige adipocytes in the white fat depots of mature cattle. The present study examined the effects of dietary vitamin A on the expression of brown/beige adipocyte-related genes in the white fat depots of fattening cattle. No significant differences were observed in the expression of Ucp1 between vitamin A-deficient cattle and control cattle. However, the expression of the other brown/beige adipocyte-related genes was slightly higher in the mesenteric fat depots of vitamin A-deficient cattle. The present results suggest that a vitamin A deficiency does not markedly affect the expression of Ucp1 in white fat depots, but imply that it may stimulate the emergence of beige adipocytes in the mesenteric fat depots of fattening cattle.

  9. Berardinelli-Seip congenital lipodystrophy 2 regulates adipocyte lipolysis, browning, and energy balance in adult animals[S

    Science.gov (United States)

    Zhou, Hongyi; Lei, Xinnuo; Benson, Tyler; Mintz, James; Xu, Xiaojing; Harris, Ruth B.; Weintraub, Neal L.; Wang, Xiaoling; Chen, Weiqin

    2015-01-01

    Mutations in BSCL2/SEIPIN cause Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2), but the mechanisms whereby Bscl2 regulates adipose tissue function are unclear. Here, we generated adipose tissue (mature) Bscl2 knockout (Ad-mKO) mice, in which Bscl2 was specifically ablated in adipocytes of adult animals, to investigate the impact of acquired Bscl2 deletion on adipose tissue function and energy balance. Ad-mKO mice displayed reduced adiposity and were protected against high fat diet-induced obesity, but not insulin resistance or hepatic steatosis. Gene expression profiling and biochemical assays revealed increased lipolysis and fatty acid oxidation in white adipose tissue (WAT) and brown adipose tissue , as well as browning of WAT, owing to induction of cAMP/protein kinase A signaling upon Bscl2 deletion. Interestingly, Bscl2 deletion reduced food intake and downregulated adipose β3-adrenergic receptor (ADRB3) expression. Impaired ADRB3 signaling partially offsets upregulated browning-induced energy expenditure and thermogenesis in Ad-mKO mice housed at ambient temperature. However, this counter-regulatory response was abrogated under thermoneutral conditions, resulting in even greater body mass loss in Ad-mKO mice. These findings suggest that Bscl2 regulates adipocyte lipolysis and β-adrenergic signaling to produce complex effects on adipose tissues and whole-body energy balance. PMID:26269358

  10. Resveratrol induces brown-like adipocyte formation in white fat through activation of AMP-activated protein kinase (AMPK) α1

    Science.gov (United States)

    Wang, Songbo; Liang, Xingwei; Yang, Qiyuan; Fu, Xing; Rogers, Carl J.; Zhu, Meijun; Rodgers, B. D.; Jiang, Qingyan; Dodson, Michael V.; Du, Min

    2014-01-01

    Objective Development of brown-like/beige adipocytes in white adipose tissue (WAT) helps to reduce obesity. Thus, we investigated the effects of resveratrol, a dietary polyphenol capable of preventing obesity and related complications in humans and animal models, on brown-like adipocyte formation in inguinal WAT (iWAT). Methods CD1 female mice (5-month-old) were fed a high-fat diet with/without 0.1% resveratrol. In addition, primary stromal vascular cells separated from iWAT were subjected to resveratrol treatment. Markers of brown-like (beige) adipogenesis were measured and the involvement of AMP-activated protein kinase (AMPK) α1 was assessed using conditional knockout. Results Resveratrol significantly increased mRNA and/or protein expression of brown adipocyte markers including uncoupling protein 1 (UCP1), PR domain-containing 16 (PRDM16), Cell death-inducing DFFA-like effector A (Cidea), elongation of very long chain fatty acids protein 3 (Elovl3), peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α), cytochrome C and pyruvate dehydrogenase (PDH) in differentiated iWAT stromal vascular cells (SVC), suggesting that resveratrol induced brown-like adipocyte formation in vitro. Concomitantly, resveratrol markedly enhanced AMPKα1 phosphorylation and differentiated SVC oxygen consumption. Such changes were absent in cells lacking AMPKα1, showing that AMPKα1 is a critical mediator of resveratrol action. Resveratrol also induced beige adipogenesis in vivo along with the appearance of multiocular adipocytes, increased UCP1 expression and enhanced fatty acid oxidation. Conclusion Resveratrol induces brown-like adipocyte formation in iWAT via AMPKα1 activation and suggest that its beneficial anti-obesity effects may be partly due to the browning of WAT and as a consequence, increased oxygen consumption. PMID:25761413

  11. Novel pharmacological probes reveal ABHD5 as a locus of lipolysis control in white and brown adipocytes.

    Science.gov (United States)

    Rondini, Elizabeth A; Mladenovic-Lucas, Ljiljana; Roush, William R; Halvorsen, Geoff; Green, Alex E; Granneman, James G

    2017-09-19

    Current knowledge regarding acute regulation of adipocyte lipolysis is largely based on receptor-mediated activation or inhibition of pathways that influence intracellular levels of cyclic AMP (cAMP), thereby affecting protein kinase A (PKA) activity. We recently identified synthetic ligands of α-β-hydrolase domain containing 5 (ABHD5) that directly activate adipose triglyceride lipase (ATGL) by dissociating ABHD5 from its inhibitory regulator, perilipin-1 (PLIN1). In the current study we used these novel ligands to determine the direct contribution of ABHD5 to various aspects of lipolysis control in white (3T3-L1) and brown adipocytes. ABHD5 ligands stimulated adipocyte lipolysis without affecting PKA-dependent phosphorylation on consensus sites of PLIN1 or HSL. Co-treatment of adipocytes with synthetic ABHD5 ligands did not alter the potency or maximal lipolysis efficacy of the β-adrenergic receptor (ADRB) agonist, isoproterenol, indicating both target a common pool of ABHD5. Reducing ADRB/PKA signaling with insulin or desensitizing ADRB suppressed lipolysis responses to a subsequent challenge with ISO, but not to ABHD5 ligands. Lastly, despite strong treatment differences in PKA-dependent phosphorylation of hormone sensitive lipase (HSL), we found that ligand-mediated activation of ABHD5 led to complete TG hydrolysis, which involved predominately ATGL, but also HSL. These results indicate that the overall pattern of lipolysis controlled by ABHD5 ligands is similar to that of isoproterenol and that ABHD5 plays a central role in the regulation of adipocyte lipolysis. As lipolysis is critical for adaptive thermogenesis and in catabolic tissue remodeling, ABHD5 ligands may provide a means of activating these processes under conditions where receptor signaling is compromised. The American Society for Pharmacology and Experimental Therapeutics.

  12. Lack of Adipocyte AMPK Exacerbates Insulin Resistance and Hepatic Steatosis through Brown and Beige Adipose Tissue Function

    DEFF Research Database (Denmark)

    Mottillo, Emilio P; Desjardins, Eric M; Crane, Justin D

    2016-01-01

    Brown (BAT) and white (WAT) adipose tissues play distinct roles in maintaining whole-body energy homeostasis, and their dysfunction can contribute to non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes. The AMP-activated protein kinase (AMPK) is a cellular energy sensor, but its role...... in mitochondrial structure, function, and markers of mitophagy. In response to a high-fat diet, iβ1β2AKO mice more rapidly developed liver steatosis as well as glucose and insulin intolerance. Thus, AMPK in adipocytes is vital for maintaining mitochondrial integrity, responding to pharmacological agents...... and thermal stress, and protecting against nutrient-overload-induced NAFLD and insulin resistance....

  13. Adipocyte-Specific Hypoxia-Inducible Factor 2α Deficiency Exacerbates Obesity-Induced Brown Adipose Tissue Dysfunction and Metabolic Dysregulation

    OpenAIRE

    García-Martín, Rubén; Alexaki, Vasileia I.; Qin, Nan; Rubín de Celis, María F.; Economopoulou, Matina; Ziogas, Athanasios; Gercken, Bettina; Kotlabova, Klara; Phieler, Julia; Ehrhart-Bornstein, Monika; Bornstein, Stefan R.; Eisenhofer, Graeme; BREIER, GEORG; Blüher, Matthias; Hampe, Jochen

    2016-01-01

    Angiogenesis is a central regulator for white (WAT) and brown (BAT) adipose tissue adaptation in the course of obesity. Here we show that deletion of hypoxia-inducible factor 2α (HIF2α) in adipocytes (by using Fabp4-Cre transgenic mice) but not in myeloid or endothelial cells negatively impacted WAT angiogenesis and promoted WAT inflammation, WAT dysfunction, hepatosteatosis, and systemic insulin resistance in obesity. Importantly, adipocyte HIF2α regulated vascular endothelial growth factor ...

  14. Anti-obesity effects of Arctii Fructus (Arctium lappa) in white/brown adipocytes and high-fat diet-induced obese mice.

    Science.gov (United States)

    Han, Yo-Han; Kee, Ji-Ye; Kim, Dae-Seung; Park, Jinbong; Jeong, Mi-Young; Mun, Jung-Geon; Park, Sung-Joo; Lee, Jong-Hyun; Um, Jae-Young; Hong, Seung-Heon

    2016-12-07

    Arctii Fructus is traditionally used in oriental pharmacies as an anti-inflammatory medicine. Although several studies have shown its anti-inflammatory effects, there have been no reports on its use in obesity related studies. In this study, the anti-obesity effect of Arctii Fructus was investigated in high-fat diet (HFD)-induced obese mice, and the effect was confirmed in white and primary cultured brown adipocytes. Arctii Fructus inhibited weight gain and reduced the mass of white adipose tissue in HFD-induced obese mice. Serum levels of triglyceride and LDL-cholesterol were reduced, and HDL-cholesterol was increased in the Arctii Fructus treated group. In 3T3-L1 cells, a water extract (WAF) and 70% EtOH extract (EtAF) of Arctii Fructus significantly inhibited adipogenesis and suppressed the expression of proliferator-activated receptor gamma and CCAAT/enhancer-binding protein alpha. In particular, EtAF activated the phosphorylation of AMP-activated protein kinase. On the other hand, uncoupling protein 1 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha, known as brown adipocytes specific genes, were increased in primary cultured brown adipocytes by WAF and EtAF. This study shows that Arctii Fructus prevents the development of obesity through the inhibition of white adipocyte differentiation and activation of brown adipocyte differentiation which suggests that Arctii Fructus could be an effective therapeutic for treating or preventing obesity.

  15. Resveratrol enhances brown adipocyte formation and function by activating AMP-activated protein kinase (AMPK) α1 in mice fed high-fat diet.

    Science.gov (United States)

    Wang, Songbo; Liang, Xingwei; Yang, Qiyuan; Fu, Xing; Zhu, Meijun; Rodgers, B D; Jiang, Qingyan; Dodson, Michael V; Du, Min

    2017-04-01

    Enhancing the formation and function of brown adipose tissue (BAT) increases thermogenesis and hence reduces obesity. Thus, we investigate the effects of resveratrol (Resv) on brown adipocyte formation and function in mouse interscapular BAT (iBAT). CD1 mice and stromal vascular cells (SVCs) isolated from iBAT were treated with Resv. Expression of brown adipogenic and thermogenic markers, and involvement of AMP-activated protein kinase (AMPK)α1 were assessed. In vivo, Resv-enhanced expression of brown adipogenic markers, PR domain-containing 16 (PRDM16) and thermogenic genes, uncoupling protein 1 (UCP1) and cytochrome C in iBAT, along with smaller lipid droplets, elevated AMPKα activity and increased oxygen consumption. Meanwhile, Resv promoted expression of PRDM16, UCP1, PGC1α, cytochrome C and pyruvate dehydrogenase (PDH) in differentiated iBAT SVCs, suggesting that Resv enhanced brown adipocyte formation and function in vitro. In addition, Resv stimulated AMPKα and oxygen consumption in differentiated iBAT SVCs. However, the promotional effects of Resv were diminished by AMPK inhibition or AMPKα1 knockout, implying the involvement of AMPKα1 in this process. Resv enhanced brown adipocyte formation and thermogenic function in mouse iBAT by promoting the expression of brown adipogenic markers via activating AMPKα1, which contributed to the anti-obesity effects of Resv. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Effect of germinated brown rice extracts on pancreatic lipase, adipogenesis and lipolysis in 3T3-L1 adipocytes.

    Science.gov (United States)

    Lim, See Meng; Goh, Yong Meng; Kuan, Wen Bin; Loh, Su Peng

    2014-11-03

    This study investigated anti-obesity effects of seven different solvent (n-hexane, toluene, dicholoromethane, ethyl acetate, absolute methanol, 80% methanol and deionized water) extracts of germinated brown rice (GBR) on pancreatic lipase activity, adipogenesis and lipolysis in 3T3-L1 adipocytes. GBR were extracted separately by employing different solvents with ultrasound-assisted. Pancreatic lipase activity was determined spectrophotometrically by measuring the hydrolysis of p-nitrophenyl butyrate (p-NPB) to p-nitrophenol at 405 nm. Adipogenesis and lipolysis were assayed in fully differentiated 3T3-L1 adipocytes by using Oil Red O staining and glycerol release measurement. GBR extract using hexane showed the highest inhibitory effect (13.58 ± 0.860%) at concentration of 200 μg/ml followed by hexane extract at 100 μg/ml (9.98 ± 1.048%) while ethyl acetate extract showed the lowest (2.62 ± 0.677%) at concentration of 200 μg/ml on pancreatic lipase activity. Water extract at 300 μg/ml showed 61.55 ± 3.824% of Oil Red O staining material (OROSM), a marker of adipogenesis. It significantly decrease (p lipolysis with 1.22-1.83 fold of greater glycerol release than control. GBR extracts especially the least polar and intermediate polar solvent extracts exhibited inhibitory effect on pancreatic lipase, decrease fat accumulation by adipocyte differentiation inhibition, and stimulate lipolysis on adipocytes. Therefore, GBR could be furthered study and developed as a functional food in helping the treatment and/or prevention of obesity.

  17. Expression of "brown-in-white" adipocyte biomarkers shows gender differences and the influence of early dietary exposure.

    Science.gov (United States)

    Servera, María; López, Nora; Serra, Francisca; Palou, Andreu

    2014-01-01

    Induction of brown-like adipocytes (brite) in white adipose tissues may allow the conversion of lipid storage cells in fat-burning cells. Little is known concerning browning potential in males compared with females. In this study, we aimed to analyse whether gender differences were present in gene expression of "brite" markers as well as the impact of dietary manipulation at both early stages and adulthood in rats. We have determined the expression of brite markers and genes associated with lipid and energy metabolism in inguinal adipose tissue in adult male and female rats. We have analysed the impact of high-fat (HF) diet in adult life and of early leucine supplementation (2 %) during lactation. Results show that although both genders have the potential to induce brite genes in inguinal adipose tissue, males expressed higher levels (CIDEA, HOXC9 and SHOX2), which would imply a higher browning capacity in comparison with females. Minor impact of HF diet in adult life was observed in most of the genes studied. Interestingly, results showed that early Leu was able to compromise the metabolic fate of white and brite adipocytes later in adult life. Leucine supplementation programmed higher expression of cell death-inducing DFFA-like effector, accompanied with induction of sterol regulatory element binding transcription 1c factor and lower UPC2 expression, particularly in females. In addition, Leucine supplementation was associated with higher expression of leptin and PPARγ and decreased carnitine palmitoyl transferase in both genders. Although the exact role of these adaptations needs further comprehensive analysis, dietary Leu supplementation at early age programmed inguinal adipose tissue in a gender specific manner.

  18. Histone Deacetylase 1 (HDAC1) Negatively Regulates Thermogenic Program in Brown Adipocytes via Coordinated Regulation of Histone H3 Lysine 27 (H3K27) Deacetylation and Methylation.

    Science.gov (United States)

    Li, Fenfen; Wu, Rui; Cui, Xin; Zha, Lin; Yu, Liqing; Shi, Hang; Xue, Bingzhong

    2016-02-26

    Inhibiting class I histone deacetylases (HDACs) increases energy expenditure, reduces adiposity, and improves insulin sensitivity in obese mice. However, the precise mechanism is poorly understood. Here, we demonstrate that HDAC1 is a negative regulator of the brown adipocyte thermogenic program. The Hdac1 level is lower in mouse brown fat (BAT) than white fat, is suppressed in mouse BAT during cold exposure or β3-adrenergic stimulation, and is down-regulated during brown adipocyte differentiation. Remarkably, overexpressing Hdac1 profoundly blocks, whereas deleting Hdac1 significantly enhances, β-adrenergic activation-induced BAT-specific gene expression in brown adipocytes. β-Adrenergic activation in brown adipocytes results in a dissociation of HDAC1 from promoters of BAT-specific genes, including uncoupling protein 1 (Ucp1) and peroxisome proliferator-activated receptor γ co-activator 1α (Pgc1α), leading to increased acetylation of histone H3 lysine 27 (H3K27), an epigenetic mark of gene activation. This is followed by dissociation of the polycomb repressive complexes, including the H3K27 methyltransferase enhancer of zeste homologue (EZH2), suppressor of zeste 12 (SUZ12), and ring finger protein 2 (RNF2) from (and concomitant recruitment of H3K27 demethylase ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX) to) Ucp1 and Pgc1α promoters, leading to decreased H3K27 trimethylation, a histone transcriptional repression mark. Thus, HDAC1 negatively regulates the brown adipocyte thermogenic program, and inhibiting Hdac1 promotes BAT-specific gene expression through a coordinated control of increased acetylation and decreased methylation of H3K27, thereby switching the transcriptional repressive state to the active state at the promoters of Ucp1 and Pgc1α. Targeting HDAC1 may be beneficial in prevention and treatment of obesity by enhancing BAT thermogenesis.

  19. Nuclear factor-κB is a common upstream signal for growth differentiation factor-5 expression in brown adipocytes exposed to pro-inflammatory cytokines and palmitate

    Energy Technology Data Exchange (ETDEWEB)

    Hinoi, Eiichi; Iezaki, Takashi; Ozaki, Kakeru; Yoneda, Yukio, E-mail: yyoneda@p.kanazawa-u.ac.jp

    2014-10-03

    Highlights: • GDF5 expression is up-regulated by IL-1β, TNF-α and palmitate in brown pre-adipocytes. • NF-κB stimulates promoter activity and expression of GDF5 in brown pre-adipocytes. • Recruitment of NF-κB to the GDF5 promoter is facilitated in BAT from ob/ob mice. • An NF-κB inhibitor prevents upregulation of GDF5 expression in brown pre-adipocytes. - Abstract: We have previously demonstrated that genetic and acquired obesity similarly led to drastic upregulation in brown adipose tissue (BAT), rather than white adipose tissue, of expression of both mRNA and corresponding protein for the bone morphogenic protein/growth differentiation factor (GDF) member GDF5 capable of promoting brown adipogenesis. In this study, we evaluated expression profiles of GDF5 in cultured murine brown pre-adipocytes exposed to pro-inflammatory cytokines and free fatty acids (FFAs), which are all shown to play a role in the pathogenesis of obesity. Both interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were effective in up-regulating GDF5 expression in a concentration-dependent manner, while similar upregulation was seen in cells exposed to the saturated FFA palmitate, but not to the unsaturated FFA oleate. In silico analysis revealed existence of the putative nuclear factor-κB (NF-κB) binding site in the 5′-flanking region of mouse GDF5, whereas introduction of NF-κB subunits drastically facilitated both promoter activity and expression of GDF5 in brown pre-adipocytes. Chromatin immunoprecipitation analysis confirmed significant facilitation of the recruitment of NF-κB to the GDF5 promoter in lysed extracts of BAT from leptin-deficient ob/ob obese mice. Upregulation o GDF5 expression was invariably inhibited by an NF-κB inhibitor in cultured brown pre-adipocytes exposed to IL-1β, TNF-α and palmitate. These results suggest that obesity leads to upregulation of GDF5 expression responsible for the promotion of brown adipogenesis through a mechanism

  20. Glycerol-3-phosphate Acyltransferase Isoform-4 (GPAT4) Limits Oxidation of Exogenous Fatty Acids in Brown Adipocytes.

    Science.gov (United States)

    Cooper, Daniel E; Grevengoed, Trisha J; Klett, Eric L; Coleman, Rosalind A

    2015-06-12

    Glycerol-3-phosphate acyltransferase-4 (GPAT4) null pups grew poorly during the suckling period and, as adults, were protected from high fat diet-induced obesity. To determine why Gpat4(-/-) mice failed to gain weight during these two periods of high fat feeding, we examined energy metabolism. Compared with controls, the metabolic rate of Gpat4(-/-) mice fed a 45% fat diet was 12% higher. Core body temperature was 1 ºC higher after high fat feeding. Food intake, fat absorption, and activity were similar in both genotypes. Impaired weight gain in Gpat4(-/-) mice did not result from increased heat loss, because both cold tolerance and response to a β3-adrenergic agonist were similar in both genotypes. Because GPAT4 comprises 65% of the total GPAT activity in brown adipose tissue (BAT), we characterized BAT function. A 45% fat diet increased the Gpat4(-/-) BAT expression of peroxisome proliferator-activated receptor α (PPAR) target genes, Cpt1α, Pgc1α, and Ucp1, and BAT mitochondria oxidized oleate and pyruvate at higher rates than controls, suggesting that fatty acid signaling and flux through the TCA cycle were enhanced. To assess the role of GPAT4 directly, neonatal BAT preadipocytes were differentiated to adipocytes. Compared with controls, Gpat4(-/-) brown adipocytes incorporated 33% less fatty acid into triacylglycerol and 46% more into the pathway of β-oxidation. The increased oxidation rate was due solely to an increase in the oxidation of exogenous fatty acids. These data suggest that in the absence of cold exposure, GPAT4 limits excessive fatty acid oxidation and the detrimental induction of a hypermetabolic state.

  1. Human induced pluripotent stem cells: A new source for brown and white adipocytes

    Institute of Scientific and Technical Information of China (English)

    Anne-Laure; Hafner; Christian; Dani

    2014-01-01

    Mesenchymal stem cells(MSCs) derived from human induced pluripotent stem cells(hiPSCs) provide a novel source for generating adipocytes, thus opening new avenues for fundamental research and clinical medicine. We present the adipogenic potential of hiPSCs and the various methods to derive hiPSC-MSCs. We discuss the main characteristic of hiPSC-MSCs, which is their low adipogenic capacity as compared to adult-MSCs. Finally, we propose several hypotheses to explanation this feature, underlying a potential critical role of the micro-environment. We favour the hypothesis that the range of factors or culture conditions required to induce adipocyte differentiation of MSCs derived from adult tissues and from embryonic-like cells could differ.

  2. Non-transactivational, dual pathways for LPA-induced Erk1/2 activation in primary cultures of brown pre-adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Holmstroem, Therese E.; Mattsson, Charlotte L.; Wang, Yanling; Iakovleva, Irina; Petrovic, Natasa [Department of Physiology, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm (Sweden); Nedergaard, Jan, E-mail: jan@metabol.su.se [Department of Physiology, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm (Sweden)

    2010-10-01

    In many cell types, G-protein-coupled receptor (GPCR)-induced Erk1/2 MAP kinase activation is mediated via receptor tyrosine kinase (RTK) transactivation, in particular via the epidermal growth factor (EGF) receptor. Lysophosphatidic acid (LPA), acting via GPCRs, is a mitogen and MAP kinase activator in many systems, and LPA can regulate adipocyte proliferation. The mechanism by which LPA activates the Erk1/2 MAP kinase is generally accepted to be via EGF receptor transactivation. In primary cultures of brown pre-adipocytes, EGF can induce Erk1/2 activation, which is obligatory and determinant for EGF-induced proliferation of these cells. Therefore, we have here examined whether LPA, via EGF transactivation, can activate Erk1/2 in brown pre-adipocytes. We found that LPA could induce Erk1/2 activation. However, the LPA-induced Erk1/2 activation was independent of transactivation of EGF receptors (or PDGF receptors) in these cells (whereas in transformed HIB-1B brown adipocytes, the LPA-induced Erk1/2 activation indeed proceeded via EGF receptor transactivation). In the brown pre-adipocytes, LPA instead induced Erk1/2 activation via two distinct non-transactivational pathways, one G{sub i}-protein dependent, involving PKC and Src activation, the other, a PTX-insensitive pathway, involving PI3K (but not Akt) activation. Earlier studies showing LPA-induced Erk1/2 activation being fully dependent on RTK transactivation have all been performed in cell lines and transfected cells. The present study implies that in non-transformed systems, RTK transactivation may not be involved in the mediation of GPCR-induced Erk1/2 MAP kinase activation.

  3. Tribbles 3 inhibits brown adipocyte differentiation and function by suppressing insulin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ha-Won; Choi, Ran Hee; McClellan, Jamie L. [Division of Applied Physiology, Department of Exercise Science, University of South Carolina, Columbia, SC 29208 (United States); Piroli, Gerardo G.; Frizzell, Norma [Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208 (United States); Tseng, Yu-Hua; Goodyear, Laurie J. [Research Division, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA 02215 (United States); Koh, Ho-Jin, E-mail: kohh@mailbox.sc.edu [Division of Applied Physiology, Department of Exercise Science, University of South Carolina, Columbia, SC 29208 (United States)

    2016-02-19

    Recent studies have demonstrated that adult humans have substantial amounts of functioning brown adipose tissue (BAT). Since BAT has been implicated as an anti-obese and anti-diabetic tissue, it is important to understand the signaling molecules that regulate BAT function. There has been a link between insulin signaling and BAT metabolism as deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function. Tribbles 3 (TRB3) is a pseudo kinase that has been shown to regulate metabolism and insulin signaling in multiple tissues but the role of TRB3 in BAT has not been studied. In this study, we found that TRB3 expression was present in BAT and overexpression of TRB3 in brown preadipocytes impaired differentiation and decreased expression of BAT markers. Furthermore, TRB3 overexpression resulted in significantly lower oxygen consumption rates for basal and proton leakage, indicating decreased BAT activity. Based on previous studies showing that deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function, we assessed insulin signaling in brown preadipocytes and BAT in vivo. Overexpression of TRB3 in cells impaired insulin-stimulated IRS1 and Akt phosphorylation, whereas TRB3KO mice displayed improved IRS1 and Akt phosphorylation. Finally, deletion of IRS1 abolished the function of TRB3 to regulate BAT differentiation and metabolism. These data demonstrate that TRB3 inhibits insulin signaling in BAT, resulting in impaired differentiation and function. - Highlights: • TRB3 is expressed in brown adipose tissue and its expression is increased during differentiation. • Overexpression of TRB3 inhibits differentiation and its activity. • Overexpression of TRB3 in brown preadipocytes inhibits insulin signaling. • TRB3KO mice displays improved insulin signaling in brown adipose tissue. • Insulin signaling is required for the effects of TRB3 to regulate brown adipose tissue differentiation and

  4. Free fatty acids and IL-6 induce adipocyte galectin-3 which is increased in white and brown adipose tissues of obese mice.

    Science.gov (United States)

    Krautbauer, Sabrina; Eisinger, Kristina; Hader, Yvonne; Buechler, Christa

    2014-10-01

    Galectin-3 regulates immune cell function and clearance of advanced glycation end products. Galectin-3 is increased in serum of obese humans and mice and most studies suggest that this protein protects from inflammation in metabolic diseases. Current data show that galectin-3 is markedly elevated in the liver, subcutaneous and intra-abdominal fat depots of mice fed a high fat diet and ob/ob mice. Galectin-3 is also increased in brown adipose tissues of these animals and immunohistochemistry confirms higher levels in adipocytes. Raised galectin-3 in obese white adipocytes has been described in the literature and regulation of adipocyte galectin-3 by metabolites with a role in obesity has been analyzed. Galectin-3 is expressed in 3T3-L1 fibroblasts and human preadipocytes and is modestly induced in mature adipocytes. In 3T3-L1 adipocytes galectin-3 is localized in the cytoplasm and is also detected in cell supernatants. Glucose does not alter soluble galectin-3. Lipopolysaccharide has no effect while TNF reduces and IL-6 raises this lectin in cell supernatants. Palmitate and oleate modestly elevate soluble galectin-3. Differentiation of 3T3-L1 cells in the presence of 100 μM and 200 μM linoleate induces soluble galectin-3 and cellular levels are upregulated by the higher concentration. Current data suggest that free fatty acids and IL-6 increase galectin-3 in adipocytes and thereby may contribute to higher levels in obesity.

  5. MicroRNAs in the regulation of brown adipocyte differentiation%调控褐色脂肪细胞分化的microRNAs

    Institute of Scientific and Technical Information of China (English)

    郭云涛; 苗向阳

    2015-01-01

    MicroRNAs (miRNAs), a class of endogenous non-coding RNA about 22 nucleotide long, regulate gene expression at the post-transcription level by inhibiting the translation or inducing the degradation of their target mRNAs in organisms. There are two types of adipose tissues:brown and white. White adipose tissues store energy in the form of tri-glycerides (TGs), while brown adipose tissues catabolize TGs to generate energy. Brown adipose tissues are of great im-portance to the research of obesity and related metabolic diseases due to their function of preventing people from obesity. A lot of studies have revealed that miRNAs play crucial roles in regulating brown adipocyte differentiation and are modulat-ed by lots of transcription factors and environmental factors, which form a complex regulatory network maintaining the homeostasis of adipose tissues. In this review, we summarize the latest studies of miRNAs in brown adipocyte differentia-tion, which might provide new strategies for the treatment of obesity and other related diseases.%MicroRNA(miRNA)是近年来在真核生物中发现的一类长约22nt的内源性非编码RNA,在动物中主要通过抑制靶 mRNA 翻译,在转录后水平调控基因表达。动物体内有两种类型的脂肪组织:褐色和白色脂肪,白色脂肪以甘油三脂形式贮存能量,而褐色脂肪利用甘油三酯产生能量。褐色脂肪因其对肥胖的拮抗作用而对研究肥胖等代谢疾病具有重要意义,大量研究表明 miRNA在褐色脂肪细胞分化中扮演着重要角色,其自身也受到多种转录因子和环境因子调控,这个复杂的调控网络维持了体内脂肪组织稳态。文章主要综述了 miRNA在褐色脂肪细胞分化中的最新研究进展,以期为利用 miRNA进行肥胖、糖尿病等相关疾病及其并发症的治疗提供新思路。

  6. Carnitine Palmitoyltransferase 1 Increases Lipolysis, UCP1 Protein Expression and Mitochondrial Activity in Brown Adipocytes

    OpenAIRE

    María Calderon-Dominguez; David Sebastián; Raquel Fucho; Minéia Weber; Mir, Joan F.; Ester García-Casarrubios; María Jesús Obregón; Antonio Zorzano; Valverde, Ángela M.; Dolors Serra; Laura Herrero

    2016-01-01

    The discovery of active brown adipose tissue (BAT) in adult humans and the fact that it is reduced in obese and diabetic patients have put a spotlight on this tissue as a key player in obesity-induced metabolic disorders. BAT regulates energy expenditure through thermogenesis; therefore, harnessing its thermogenic fat-burning power is an attractive therapeutic approach. We aimed to enhance BAT thermogenesis by increasing its fatty acid oxidation (FAO) rate. Thus, we expressed carnitine palmit...

  7. Tribbles 3 inhibits brown adipocyte differentiation and function by suppressing insulin signaling.

    Science.gov (United States)

    Jeong, Ha-Won; Choi, Ran Hee; McClellan, Jamie L; Piroli, Gerardo G; Frizzell, Norma; Tseng, Yu-Hua; Goodyear, Laurie J; Koh, Ho-Jin

    2016-02-19

    Recent studies have demonstrated that adult humans have substantial amounts of functioning brown adipose tissue (BAT). Since BAT has been implicated as an anti-obese and anti-diabetic tissue, it is important to understand the signaling molecules that regulate BAT function. There has been a link between insulin signaling and BAT metabolism as deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function. Tribbles 3 (TRB3) is a pseudo kinase that has been shown to regulate metabolism and insulin signaling in multiple tissues but the role of TRB3 in BAT has not been studied. In this study, we found that TRB3 expression was present in BAT and overexpression of TRB3 in brown preadipocytes impaired differentiation and decreased expression of BAT markers. Furthermore, TRB3 overexpression resulted in significantly lower oxygen consumption rates for basal and proton leakage, indicating decreased BAT activity. Based on previous studies showing that deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function, we assessed insulin signaling in brown preadipocytes and BAT in vivo. Overexpression of TRB3 in cells impaired insulin-stimulated IRS1 and Akt phosphorylation, whereas TRB3KO mice displayed improved IRS1 and Akt phosphorylation. Finally, deletion of IRS1 abolished the function of TRB3 to regulate BAT differentiation and metabolism. These data demonstrate that TRB3 inhibits insulin signaling in BAT, resulting in impaired differentiation and function.

  8. Adipocyte-Specific Hypoxia-Inducible Factor 2α Deficiency Exacerbates Obesity-Induced Brown Adipose Tissue Dysfunction and Metabolic Dysregulation.

    Science.gov (United States)

    García-Martín, Rubén; Alexaki, Vasileia I; Qin, Nan; Rubín de Celis, María F; Economopoulou, Matina; Ziogas, Athanasios; Gercken, Bettina; Kotlabova, Klara; Phieler, Julia; Ehrhart-Bornstein, Monika; Bornstein, Stefan R; Eisenhofer, Graeme; Breier, Georg; Blüher, Matthias; Hampe, Jochen; El-Armouche, Ali; Chatzigeorgiou, Antonios; Chung, Kyoung-Jin; Chavakis, Triantafyllos

    2015-11-16

    Angiogenesis is a central regulator for white (WAT) and brown (BAT) adipose tissue adaptation in the course of obesity. Here we show that deletion of hypoxia-inducible factor 2α (HIF2α) in adipocytes (by using Fabp4-Cre transgenic mice) but not in myeloid or endothelial cells negatively impacted WAT angiogenesis and promoted WAT inflammation, WAT dysfunction, hepatosteatosis, and systemic insulin resistance in obesity. Importantly, adipocyte HIF2α regulated vascular endothelial growth factor (VEGF) expression and angiogenesis of obese BAT as well as its thermogenic function. Consistently, obese adipocyte-specific HIF2α-deficient mice displayed BAT dysregulation, associated with reduced levels of uncoupling protein 1 (UCP1) and a dysfunctional thermogenic response to cold exposure. VEGF administration reversed WAT and BAT inflammation and BAT dysfunction in adipocyte HIF2α-deficient mice. Together, our findings show that adipocyte HIF2α is protective against maladaptation to obesity and metabolic dysregulation by promoting angiogenesis in both WAT and BAT and by counteracting obesity-mediated BAT dysfunction. Copyright © 2016 García-Martín et al.

  9. Germinated brown rice extract inhibits adipogenesis through the down-regulation of adipogenic genes in 3T3-L1 adipocytes.

    Science.gov (United States)

    Ho, Jin-Nyoung; Son, Mi-Eun; Lim, Won-Chul; Lim, Seung-Taik; Cho, Hong-Yon

    2013-09-01

    The aim of this study was to examine the anti-adipogenic effect of germinated brown rice methanol extract (GBR) in 3T3-L1 adipocytes. The GBR inhibited adipocyte differentiation was measured by Oil Red O staining and glycerol-3-phosphate dehydrogenase (GPDH) activity in a dose-dependent manner without initiating any cytotoxicity. The mRNA levels of adipogenic transcription factors such as CCAAT/enhancer binding protein (C/EBPα), proliferator-activated receptorγ (PPARγ), and sterol regulatory element-binding protein-1c (SREBP-1c), and adipogenic genes, such as fatty acid synthase (FAS), adipocyte fatty acid-binding protein (aP2), and lipoprotein lipase (LPL), were significantly down-regulated by treatment with GBR when compared to that of untreated control cells. Moreover, tumor necrosis factor-α (TNF-α) and interlukin-6 (IL-6) mRNA expressions were attenuated by GBR in mature adipocytes. These data suggest that GBR exhibits an anti-adipogenic effect through the suppression of adipogenesis in 3T3-L1 adipocytes.

  10. Lecithin:Cholesterol Acyltransferase (LCAT) Deficiency Promotes Differentiation of Satellite Cells to Brown Adipocytes in a Cholesterol-dependent Manner.

    Science.gov (United States)

    Nesan, Dinushan; Tavallaee, Ghazaleh; Koh, Deborah; Bashiri, Amir; Abdin, Rawand; Ng, Dominic S

    2015-12-18

    Our laboratory previously reported that lecithin:cholesterol acyltransferase (LCAT) and LDL receptor double knock-out mice (Ldlr(-/-)xLcat(-/-) or DKO) spontaneously develop functioning ectopic brown adipose tissue (BAT) in skeletal muscle, putatively contributing to protection from the diet-induced obesity phenotype. Here we further investigated their developmental origin and the mechanistic role of LCAT deficiency. Gene profiling of skeletal muscle in DKO newborns and adults revealed a classical lineage. Primary quiescent satellite cells (SC) from chow-fed DKO mice, not in Ldlr(-/-)xLcat(+/+) single-knock-out (SKO) or C57BL/6 wild type, were found to (i) express exclusively classical BAT-selective genes, (ii) be primed to express key functional BAT genes, and (iii) exhibit markedly increased ex vivo adipogenic differentiation into brown adipocytes. This gene priming effect was abrogated upon feeding the mice a 2% high cholesterol diet in association with accumulation of excess intracellular cholesterol. Ex vivo cholesterol loading of chow-fed DKO SC recapitulated the effect, indicating that cellular cholesterol is a key regulator of SC-to-BAT differentiation. Comparing adipogenicity of Ldlr(+/+)xLcat(-/-) (LCAT-KO) SC with DKO SC identified a role for LCAT deficiency in priming SC to express BAT genes. Additionally, we found that reduced cellular cholesterol is important for adipogenic differentiation, evidenced by increased induction of adipogenesis in cholesterol-depleted SC from both LCAT-KO and SKO mice. Taken together, we conclude that ectopic BAT in DKO mice is classical in origin, and its development begins in utero. We further showed complementary roles of LCAT deficiency and cellular cholesterol reduction in the SC-to-BAT adipogenesis. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. A novel SP1/SP3 dependent intronic enhancer governing transcription of the UCP3 gene in brown adipocytes.

    Directory of Open Access Journals (Sweden)

    Christoph Hoffmann

    Full Text Available Uncoupling protein (UCP 3 is a mitochondrial inner membrane protein implicated in lipid handling and metabolism of reactive oxygen species. Its transcription is mainly regulated by peroxisome proliferator-activated receptors (PPAR, a family of nuclear hormone receptors. Employing bandshift assays, RNA interference and reporter gene assays we examine an intronic region in the UCP3 gene harboring a cis-element essential for expression in brown adipocytes. We demonstrate binding of SP1 and SP3 to this element which is adjacent to a direct repeat 1 element mediating activation of UCP3 expression by PPARγ agonists. Transactivation mediated by these elements is interdependent and indispensable for UCP3 expression. Systematic deletion uncovered a third binding element, a putative NF1 site, in close proximity to the SP1/3 and PPARγ binding elements. Data mining demonstrated binding of MyoD and Myogenin to this third element in C2C12 cells, and, furthermore, revealed recruitment of p300. Taken together, this intronic region is the main enhancer driving UCP3 expression with SP1/3 and PPARγ as the core factors required for expression.

  12. Reprogrammed Functional Brown Adipocytes Ameliorate Insulin Resistance and Dyslipidemia in Diet-Induced Obesity and Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Tsunao Kishida

    2015-10-01

    Full Text Available Brown adipocytes (BAs play important roles in body temperature regulation, energy balance, and carbohydrate and lipid metabolism. Activities of BAs are remarkably diminished in obese and diabetic patients, providing possibilities of transplanting functional BAs resulting in therapeutic benefit. Here, we show generation of functional BAs by cellular reprogramming procedures. Transduction of the PRDM16 gene into iPSC-derived embryoid bodies induced BA phenotypes (iBAs. Moreover, normal human fibroblasts were directly converted into BAs (dBAs by C/EBP-β and C-MYC gene transduction. Approximately 90% of the fibroblasts were successfully converted within 12 days. The dBAs were highly active in mitochondrial biogenesis and oxidative metabolism. Mouse dBAs were induced by Prdm16, C/ebp-β, and L-myc genes, and after transplantation, they significantly reduced diet-induced obesity and insulin resistance in an UCP1-dependent manner. Thus, highly functional BAs can be generated by cellular reprogramming, suggesting a promising tailor-made cell therapy against metabolic disorders including type 2 diabetes mellitus.

  13. Endocrine and autocrine/paracrine modulators of brown adipose tissue mass and activity as novel therapeutic strategies against obesity and type 2 diabetes.

    Science.gov (United States)

    Scheideler, Marcel; Herzig, Stephan; Georgiadi, Anastasia

    2017-08-29

    The dramatically increasing world-wide prevalence of obesity is recognized as a risk factor for the development of various diseases. The growing research on the role of adipose tissue in controlling energy homeostasis and insulin sensitivity has revealed that the promotion of brown adipose tissue (BAT) activity and the browning of white adipose tissue (WAT) leads to multiple health benefits and prevents obesity and type 2 diabetes (T2D). Inducible thermogenic adipocytes do exist in adult humans and are linked with increased energy combustion and lower body fat mass. Thus brown adipocytes are currently placed at the center of attention for novel therapeutic strategies against metabolic diseases such as obesity and diabetes. Besides the classical, norepinephrine-mediated sympathetic recruitment and activation of thermogenic adipocytes, a number of novel circulating factors have been recently identified to have a positive or negative impact on thermogenic adipocyte formation and activity. In this review their mechanism of action and the plausible therapeutic applications will be summarized and discussed.

  14. Lipolytic products activate peroxisome proliferator-activated receptor (PPAR) α and δ in brown adipocytes to match fatty acid oxidation with supply.

    Science.gov (United States)

    Mottillo, Emilio P; Bloch, Ainsley E; Leff, Todd; Granneman, James G

    2012-07-20

    β-Adrenergic receptors (β-ARs) promote brown adipose tissue (BAT) thermogenesis by mobilizing fatty acids and inducing the expression of oxidative genes. β-AR activation increases the expression of oxidative genes by elevating cAMP, but whether lipolytic products can modulate gene expression is not known. This study examined the role that adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) plays in the induction of gene expression. Activation of brown adipocytes by β-AR agonism or 8-bromo-cyclic AMP increased the expression of PGC1α, PDK4, PPARα, uncoupling protein 1 (UCP1), and neuron-derived orphan receptor-1 (NOR-1), and concurrent inhibition of HSL reduced the induction of PGC1α, PDK4, PPARα, and UCP1 but not NOR-1. Similar results were observed in the BAT of mice following pharmacological or genetic inhibition of HSL and in brown adipocytes with stable knockdown of ATGL. Conversely, treatments that increase endogenous fatty acids elevated the expression of oxidative genes. Pharmacological antagonism and siRNA knockdown indicate that PPARα and PPARδ modulate the induction of oxidative genes by β-AR agonism. Using a live cell fluorescent reporter assay of PPAR activation, we demonstrated that ligands for PPARα and -δ, but not PPARγ, were rapidly generated at the lipid droplet surface and could transcriptionally activate PPARα and -δ. Knockdown of ATGL reduced cAMP-mediated induction of genes involved in fatty acid oxidation and oxidative phosphorylation. Consequently, ATGL knockdown reduced maximal oxidation of fatty acids, but not pyruvate, in response to cAMP stimulation. Overall, the results indicate that lipolytic products can activate PPARα and PPARδ in brown adipocytes, thereby expanding the oxidative capacity to match enhanced fatty acid supply.

  15. Role of PRDM16 in the activation of brown fat programming. Relevance to the development of obesity.

    Science.gov (United States)

    Becerril, Sara; Gómez-Ambrosi, Javier; Martín, Marina; Moncada, Rafael; Sesma, Pilar; Burrell, María A; Frühbeck, Gema

    2013-11-01

    From a histological and functional point of view, two types of adipose tissue can be identified. As opposed to the mainly unilocular white adipocytes, brown adipocytes possess plenty of small multilocular lipid droplets and dissipate energy as heat. Moreover, two distinct types of brown adipose cells exist. In vivo fate mapping experiments of brown adipose tissue (BAT) precursors suggest that classical brown adipocytes and skeletal myoblasts originate from a common mesenchymal, myogenic factor 5 (Myf5)-positive precursor cell. In addition to the classical brown adipocytes, thermogenic brown-like adipocytes (brite/beige cells) may appear within white adipose tissue (WAT) depots, sharing many of the morphological and functional features of brown adipocytes, but arising from a Myf5-negative lineage. In humans, the conversion of white fat cells into brite adipocytes could be a strategy to increase energy expenditure. The zinc finger transcription factor Prdm16 controls the bidirectional fate decision between brown adipocytes and myoblasts. Prdm16 determines the brown fat-like programme and thermogenesis in both brown and white adipose tissues. Moreover, the expression of this transcriptional regulator is strongly correlated with beige cell-selective genes. From a therapeutical point of view, the potential of inducing BAT or the transdifferentiation of WAT into beige cells by enhancing Prdm16 expression, as well as the identification of mechanisms of Prdm16 function and regulation represent potentially exciting new approaches for treatment or prevention of obesity and related diseases.

  16. FABP3 and brown adipocyte-characteristic mitochondrial fatty acid oxidation enzymes are induced in beige cells in a different pathway from UCP1.

    Science.gov (United States)

    Nakamura, Yuki; Sato, Takahiro; Shiimura, Yuki; Miura, Yoshiki; Kojima, Masayasu

    2013-11-08

    Cold exposure and β3-adrenergic receptor agonist (CL316,243) treatment induce the production of beige cells, which express brown adipocytes(BA)-specific UCP1 protein, in white adipose tissue (WAT). It remains unclear whether the beige cells, which have different gene expression patterns from BA, express BA-characteristic fatty acid oxidation (FAO) proteins. Here we found that 5 day cold exposure and CL316,243 treatment of WAT, but not CL316,243 treatment of primary adipocytes of C57BL/6J mice, increased mRNA levels of BA-characteristic FAO proteins. These results suggest that BA-characteristic FAO proteins are induced in beige cells in a different pathway from UCP1.

  17. L-Arginine promotes protein synthesis and cell growth in brown adipocyte precursor cells via the mTOR signal pathway.

    Science.gov (United States)

    Ma, Xi; Han, Meng; Li, Defa; Hu, Shengdi; Gilbreath, Kyler R; Bazer, Fuller W; Wu, Guoyao

    2017-05-01

    L-Arginine has been reported to enhance brown adipose tissue developments in fetal lambs of obese ewes, but the underlying mechanism is unknown. The present study tested the hypothesis that L-arginine stimulates growth and development of brown adipocyte precursor cells (BAPCs) through activation of mammalian target of rapamycin cell signaling. BAPCs isolated from fetal lambs at day 90 of gestation were incubated   for 6 h in arginine-free DMEM, and then cultured in DMEM with concentrations of 50, 100, 200, 500 or 1000 μmol L-arginine/L for 24-96 h. Cell proliferation, protein turnover, the mammalian target of rapamycin (mTOR) signaling pathway and pre-adipocyte differentiation markers were determined. L-arginine treatment enhanced (P L (the concentrations of arginine in the maternal plasma of obese ewes), 200 μmol L-arginine/L (the concentrations of arginine in the maternal plasma of obese ewes receiving arginine supplementation) increased (P L activates mTOR cell signaling in BAPCs and enhances their growth and development in a dose-dependent manner. Our results provide a mechanism for arginine supplementation to enhance the development of brown adipose tissue in fetal lambs.

  18. Effects of noradrenaline on the cell-surface glucose transporters in cultured brown adipocytes: novel mechanism for selective activation of GLUT1 glucose transporters.

    Science.gov (United States)

    Shimizu, Y; Satoh, S; Yano, H; Minokoshi, Y; Cushman, S W; Shimazu, T

    1998-01-01

    Glucose transport into rat brown adipocytes has been shown to be stimulated directly by the sympathetic neurotransmitter, noradrenaline, without a significant increase in the protein content of either GLUT1 or GLUT4 glucose transporter in the plasma membrane [Shimizu, Kielar, Minokoshi and Shimazu (1996) Biochem. J. 314, 485-490]. In the present study, we labelled the exofacial glucose-binding sites of GLUT1 and GLUT4 with a membrane-impermeant photoaffinity reagent, 2-N-[4-(1-azitrifluoroethyl)benzoyl]-[2-3H]1,3-bis- (D-mannos-4-yloxy)-2-propylamine (ATB-[3H]BMPA), to determine which isoform is responsible for the noradrenaline-induced increase in glucose transport into intact brown adipocytes in culture. Insulin stimulated the rate of hexose transport by increasing ATB-[3H]BMPA-labelled cell-surface GLUT4. In contrast, the noradrenaline-induced increase in glucose transport was not accompanied by an increased ATB-[3H]BMPA labelling of GLUT4, nor with an increased amount of GLUT4 in the plasma membrane fraction as assessed by Western blotting, indicating that noradrenaline does not promote the translocation of GLUT4. However, noradrenaline induced an increase in photoaffinity labelling of cell-surface GLUT1 without an apparent increase in the immunoreactive GLUT1 protein in the plasma membrane. This is suggestive of an increased affinity of GLUT1 for the ligand. In fact, the Ki value of non-radioactive ATB-BMPA for 2-deoxy-D-glucose uptake was significantly decreased after treatment of the cells with noradrenaline. The increased photoaffinity labelling of GLUT1 and increased glucose transport caused by noradrenaline were inhibited by a cAMP antagonist, cAMP-S Rp-isomer. These results demonstrate that noradrenaline stimulates glucose transport in brown adipocytes by enhancing the functional activity of GLUT1 through a cAMP-dependent mechanism. PMID:9461536

  19. Habitable Planets Eclipsing Brown Dwarfs: Strategies for Detection and Characterization

    CERN Document Server

    Belu, Adrian R; Raymond, Sean N; Pallé, Enric; Street, Rachel; Sahu, D K; Von Braun, Kaspar; Bolmont, Emeline; Figueira, Pedro; Anupama, G C; Ribas, Ignasi

    2013-01-01

    Given the very close proximity of their habitable zones, brown dwarfs represent high-value targets in the search for nearby transiting habitable planets that may be suitable for follow-up occultation spectroscopy. In this paper we develop search strategies to find habitable planets transiting brown dwarfs depending on their maximum habitable orbital period (PHZ out). Habitable planets with PHZ out shorter than the useful duration of a night (e.g. 8-10 hrs) can be screened with 100 percent completeness from a single location and in a single night (near-IR). More luminous brown dwarfs require continuous monitoring for longer duration, e.g. from space or from a longitude-distributed network (one test scheduling achieved - 3 telescopes, 13.5 contiguous hours). Using a simulated survey of the 21 closest known brown dwarfs (within 7 pc) we find that the probability of detecting at least one transiting habitable planet is between 4.5 +5.6-1.4 and 56 +31-13 percent, depending on our assumptions. We calculate that bro...

  20. MicroRNA Functions in Brite/Brown Fat — Novel Perspectives towards Anti-Obesity Strategies

    Directory of Open Access Journals (Sweden)

    Michael Karbiener

    2014-09-01

    Full Text Available Current anti-obesity strategies are aiming at restricting energy uptake, but still, obesity treatment is far from being satisfactory. The discovery of active brown adipose tissue (BAT in adult humans currently opens new avenues to combat obesity and follow-up complications as it tackles the other site of the energy balance: energy expenditure via non-shivering thermogenesis. This process of energy dissipation in the adipose tissue is tightly controlled, and the elucidation of its regulatory network is a key plank for therapeutic applications. MicroRNAs (miRNAs belong to a novel class of regulatory determinants which are small non-coding RNAs with vital roles in regulating gene expression that also play a role in many human diseases. In this review we summarize miRNAs which have been shown to govern thermogenic, i.e. brite or brown, adipocyte recruitment and physiology. Notably, most miRNAs in this context have so far been characterized solely in mice, revealing a great demand for more human studies. As in the context of other diseases, RNA-based therapeutics have meanwhile entered clinical trials, further exploring the functions of miRNAs in brown and white adipose tissues could result in novel therapeutic approaches to treat obesity and its follow-up complications.

  1. Oleoylethanolamide enhances β-adrenergic-mediated thermogenesis and white-to-brown adipocyte phenotype in epididymal white adipose tissue in rat

    Directory of Open Access Journals (Sweden)

    Juan Suárez

    2014-01-01

    Full Text Available β-adrenergic receptor activation promotes brown adipose tissue (BAT β-oxidation and thermogenesis by burning fatty acids during uncoupling respiration. Oleoylethanolamide (OEA can inhibit feeding and stimulate lipolysis by activating peroxisome proliferator-activating receptor-α (PPARα in white adipose tissue (WAT. Here we explore whether PPARα activation potentiates the effect of β3-adrenergic stimulation on energy balance mediated by the respective agonists OEA and CL316243. The effect of this pharmacological association on feeding, thermogenesis, β-oxidation, and lipid and cholesterol metabolism in epididymal (eWAT was monitored. CL316243 (1 mg/kg and OEA (5 mg/kg co-administration over 6 days enhanced the reduction of both food intake and body weight gain, increased the energy expenditure and reduced the respiratory quotient (VCO2/VO2. This negative energy balance agreed with decreased fat mass and increased BAT weight and temperature, as well as with lowered plasma levels of triglycerides, cholesterol, nonessential fatty acids (NEFAs, and the adipokines leptin and TNF-α. Regarding eWAT, CL316243 and OEA treatment elevated levels of the thermogenic factors PPARα and UCP1, reduced p38-MAPK phosphorylation, and promoted brown-like features in the white adipocytes: the mitochondrial (Cox4i1, Cox4i2 and BAT (Fgf21, Prdm16 genes were overexpressed in eWAT. The enhancement of the fatty-acid β-oxidation factors Cpt1b and Acox1 in eWAT was accompanied by an upregulation of de novo lipogenesis and reduced expression of the unsaturated-fatty-acid-synthesis enzyme gene, Scd1. We propose that the combination of β-adrenergic and PPARα receptor agonists promotes therapeutic adipocyte remodelling in eWAT, and therefore has a potential clinical utility in the treatment of obesity.

  2. Pharmacological and nutritional agents promoting browning of white adipose tissue.

    Science.gov (United States)

    Bonet, M Luisa; Oliver, Paula; Palou, Andreu

    2013-05-01

    The role of brown adipose tissue in the regulation of energy balance and maintenance of body weight is well known in rodents. Recently, interest in this tissue has re-emerged due to the realization of active brown-like adipose tissue in adult humans and inducible brown-like adipocytes in white adipose tissue depots in response to appropriate stimuli ("browning process"). Brown-like adipocytes that appear in white fat depots have been called "brite" (from brown-in-white) or "beige" adipocytes and have characteristics similar to brown adipocytes, in particular the capacity for uncoupled respiration. There is controversy as to the origin of these brite/beige adipocytes, but regardless of this, induction of the browning of white fat represents an attractive potential strategy for the management and treatment of obesity and related complications. Here, the different physiological, pharmacological and dietary determinants that have been linked to white-to-brown fat remodeling and the molecular mechanisms involved are reviewed in detail. In the light of available data, interesting therapeutic perspectives can be expected from the use of specific drugs or food compounds able to induce a program of brown fat differentiation including uncoupling protein 1 expression and enhancing oxidative metabolism in white adipose cells. However, additional research is needed, mainly focused on the physiological relevance of browning and its dietary control, where the use of ferrets and other non-rodent animal models with a more similar adipose tissue organization and metabolism to humans could be of much help. This article is part of a Special Issue entitled Brown and White Fat: From Signaling to Disease.

  3. Synergism between cAMP and PPARγ Signalling in the Initiation of UCP1 Gene Expression in HIB1B Brown Adipocytes

    Directory of Open Access Journals (Sweden)

    H. Y. Chen

    2013-01-01

    Full Text Available Expression of the brown adipocyte-specific gene, uncoupling protein 1 (UCP1, is increased by both PPARγ stimulation and cAMP activation through their ability to stimulate the expression of the PPAR coactivator PGC1α. In HIB1B brown preadipocytes, combination of the PPARγ agonist, rosiglitazone, and the cAMP stimulator forskolin synergistically increased UCP1 mRNA expression, but PGC1α expression was only increased additively by the two drugs. The PPARγ antagonist, GW9662, and the PKA inhibitor, H89, both inhibited UCP1 expression stimulated by rosiglitazone and forskolin but PGC1α expression was not altered to the same extent. Reporter studies demonstrated that combined rosiglitazone and forskolin synergistically activated transcription from a full length 3.1 kbp UCP1 luciferase promoter construct, but the response was only additive and much reduced when a minimal 260 bp proximal UCP1 promoter was examined. Rosiglitazone and forskolin in combination were able to synergistically stimulate promoters comprising of tandem repeats of either PPREs or CREs. We conclude that rosiglitazone and forskolin act together to synergistically activate the UCP1 promoter directly rather than by increasing PGC1α expression and by a mechanism involving cross-talk between the signalling systems regulating the CRE and PPRE on the promoters.

  4. De Novo Reconstruction of Adipose Tissue Transcriptomes Reveals Long Non-coding RNA Regulators of Brown Adipocyte Development.

    Science.gov (United States)

    Alvarez-Dominguez, Juan R; Bai, Zhiqiang; Xu, Dan; Yuan, Bingbing; Lo, Kinyui Alice; Yoon, Myeong Jin; Lim, Yen Ching; Knoll, Marko; Slavov, Nikolai; Chen, Shuai; Chen, Peng; Lodish, Harvey F; Sun, Lei

    2015-05-01

    Brown adipose tissue (BAT) protects against obesity by promoting energy expenditure via uncoupled respiration. To uncover BAT-specific long non-coding RNAs (lncRNAs), we used RNA-seq to reconstruct de novo transcriptomes of mouse brown, inguinal white, and epididymal white fat and identified ∼1,500 lncRNAs, including 127 BAT-restricted loci induced during differentiation and often targeted by key regulators PPARγ, C/EBPα, and C/EBPβ. One of them, lnc-BATE1, is required for establishment and maintenance of BAT identity and thermogenic capacity. lnc-BATE1 inhibition impairs concurrent activation of brown fat and repression of white fat genes and is partially rescued by exogenous lnc-BATE1 with mutated siRNA-targeting sites, demonstrating a function in trans. We show that lnc-BATE1 binds heterogeneous nuclear ribonucleoprotein U and that both are required for brown adipogenesis. Our work provides an annotated catalog for the study of fat depot-selective lncRNAs and establishes lnc-BATE1 as a regulator of BAT development and physiology.

  5. Habitable Planets Eclipsing Brown Dwarfs: Strategies for Detection and Characterization

    Science.gov (United States)

    Belu, Adrian R.; Selsis, Franck; Raymond, Sean N.; Pallé, Enric; Street, Rachel; Sahu, D. K.; von Braun, Kaspar; Bolmont, Emeline; Figueira, Pedro; Anupama, G. C.; Ribas, Ignasi

    2013-05-01

    Given the very close proximity of their habitable zones, brown dwarfs (BDs) represent high-value targets in the search for nearby transiting habitable planets that may be suitable for follow-up occultation spectroscopy. In this paper, we develop search strategies to find habitable planets transiting BDs depending on their maximum habitable orbital period (P HZ out). Habitable planets with P HZ out shorter than the useful duration of a night (e.g., 8-10 hr) can be screened with 100% completeness from a single location and in a single night (near-IR). More luminous BDs require continuous monitoring for longer duration, e.g., from space or from a longitude-distributed network (one test scheduling achieved three telescopes, 13.5 contiguous hours). Using a simulated survey of the 21 closest known BDs (within 7 pc) we find that the probability of detecting at least one transiting habitable planet is between 4.5^{+5.6}_{-1.4}% and 56^{+31}_{-13}%, depending on our assumptions. We calculate that BDs within 5-10 pc are characterizable for potential biosignatures with a 6.5 m space telescope using ~1% of a five-year mission's lifetime spread over a contiguous segment only one-fifth to one-tenth of this duration.

  6. HABITABLE PLANETS ECLIPSING BROWN DWARFS: STRATEGIES FOR DETECTION AND CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Belu, Adrian R.; Selsis, Franck; Raymond, Sean N.; Bolmont, Emeline [Universite de Bordeaux, LAB, UMR 5804, F-33270, Floirac (France); Palle, Enric [Instituto de Astrofisica de Canarias, E-38205 La Laguna (Spain); Street, Rachel [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Sahu, D. K.; Anupama, G. C. [Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India); Von Braun, Kaspar [NASA Exoplanet Science Institute, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States); Figueira, Pedro [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Ribas, Ignasi, E-mail: belu@obs.u-bordeaux1.fr [Institut de Ciencies de l' Espai (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C5, parell, 2a pl., E-08193 Bellaterra (Spain)

    2013-05-10

    Given the very close proximity of their habitable zones, brown dwarfs (BDs) represent high-value targets in the search for nearby transiting habitable planets that may be suitable for follow-up occultation spectroscopy. In this paper, we develop search strategies to find habitable planets transiting BDs depending on their maximum habitable orbital period (P{sub HZ{sub out}}). Habitable planets with P{sub HZ{sub out}} shorter than the useful duration of a night (e.g., 8-10 hr) can be screened with 100% completeness from a single location and in a single night (near-IR). More luminous BDs require continuous monitoring for longer duration, e.g., from space or from a longitude-distributed network (one test scheduling achieved three telescopes, 13.5 contiguous hours). Using a simulated survey of the 21 closest known BDs (within 7 pc) we find that the probability of detecting at least one transiting habitable planet is between 4.5{sup +5.6}{sub -1.4}% and 56{sup +31}{sub -13}%, depending on our assumptions. We calculate that BDs within 5-10 pc are characterizable for potential biosignatures with a 6.5 m space telescope using {approx}1% of a five-year mission's lifetime spread over a contiguous segment only one-fifth to one-tenth of this duration.

  7. A Management Strategy for Kenai Peninsula Brown Bears

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Increasing human activity and land development on the Kenai Peninsula, Alaska has brought about concern for the brown bear (Ursus arctos) population. The human...

  8. Exploring the activated adipogenic niche: interactions of macrophages and adipocyte progenitors.

    Science.gov (United States)

    Lee, Yun-Hee; Thacker, Robert I; Hall, Brian Eric; Kong, Raymond; Granneman, James G

    2014-01-01

    Adult adipose tissue contains a large supply of progenitors that can renew fat cells for homeostatic tissue maintenance and adaptive growth or regeneration in response to external challenges. However, the in vivo mechanisms that control adipocyte progenitor behavior are poorly characterized. We recently demonstrated that recruitment of adipocyte progenitors by macrophages is a central feature of adipose tissue remodeling under various adipogenic conditions. Catabolic remodeling of white adipose tissue by β3-adrenergic receptor stimulation requires anti-inflammatory M2-polarized macrophages to clear dying adipocytes and to recruit new brown adipocytes from progenitors. In this Extra Views article, we discuss in greater detail the cellular elements of adipogenic niches and report a strategy to isolate and characterize the subpopulations of macrophages and adipocyte progenitors that actively participate in adrenergic tissue remodeling. Further characterization of these subpopulations may facilitate identification of new cellular targets to improve metabolic and immune function of adipose tissue.

  9. Brown Adipogenic Reprogramming Induced by a Small Molecule

    Directory of Open Access Journals (Sweden)

    Baoming Nie

    2017-01-01

    Full Text Available Brown adipose tissue (BAT has attracted considerable research interest because of its therapeutic potential to treat obesity and associated metabolic diseases. Augmentation of brown fat mass and/or its function may represent an attractive strategy to enhance energy expenditure. Using high-throughput phenotypic screening to induce brown adipocyte reprogramming in committed myoblasts, we identified a retinoid X receptor (RXR agonist, bexarotene (Bex, that efficiently converted myoblasts into brown adipocyte-like cells. Bex-treated mice exhibited enlarged BAT mass, enhanced BAT function, and a modest browning effect in subcutaneous white adipose tissue (WAT. Expression analysis showed that Bex initiated several “browning” pathways at an early stage during brown adipocyte reprogramming. Our findings suggest RXRs as new master regulators that control brown and beige fat development and activation, unlike the common adipogenic regulator PPARγ. Moreover, we demonstrated that selective RXR activation may potentially offer a therapeutic approach to manipulate brown/beige fat function in vivo.

  10. Conservation Strategy for Brown Bear and Its Habitat in Nepal

    Directory of Open Access Journals (Sweden)

    Achyut Aryal

    2012-08-01

    Full Text Available The Himalaya region of Nepal encompasses significant habitats for several endangered species, among them the brown bear (Ursus arctos pruinosus. However, owing to the remoteness of the region and a dearth of research, knowledge on the conservation status, habitat and population size of this species is lacking. Our aim in this paper is to report a habitat survey designed to assess the distribution and habitat characteristics of the brown bear in the Nepalese Himalaya, and to summarize a conservation action plan for the species devised at a pair of recent workshops held in Nepal. Results of our survey showed that brown bear were potentially distributed between 3800 m and 5500 m in the high mountainous region of Nepal, across an area of 4037 km2 between the eastern border of Shey Phoksundo National Park (SPNP and the Manasalu Conservation Area (MCA. Of that area, 2066 km2 lie inside the protected area (350 km2 in the MCA; 1716 km2 in the Annapurna Conservation Area and 48% (1917 km2 lies outside the protected area in the Dolpa district. Furthermore, 37% of brown bear habitat also forms a potential habitat for blue sheep (or bharal, Pseudois nayaur, and 17% of these habitats is used by livestock, suggesting a significant potential for resource competition. Several plant species continue to be uprooted by local people for fuel wood. Based on the results of our field survey combined with consultations with local communities and scientists, we propose that government and non-government organizations should implement a three-stage program of conservation activities for the brown bear. This program should: (a Detail research activities in and outside the protected area of Nepal; (b support livelihood and conservation awareness at local and national levels; and (c strengthen local capacity and reduce human-wildlife conflict in the region.

  11. Temporal profiling of the adipocyte proteome during differentiation using a five-plex SILAC based strategy

    DEFF Research Database (Denmark)

    Molina, Henrik; Yang, Yi; Ruch, Travis;

    2009-01-01

    adipocyte differentiation has not been documented previously. For example, THO complex 4, a context-dependent transcriptional activator in the T-cell receptor alpha enhancer complex, showed highest expression at middle stage of adipogenesis, while SNF2 alpha, a chromatin remodeling protein......The adipose tissue has important secretory and endocrine functions in humans. The regulation of adipocyte differentiation has been actively pursued using transcriptomic methods over the last several years. Quantitative proteomics has emerged as a promising approach to obtain temporal profiles...... of biological processes such as differentiation. Stable isotope labeling with amino acids in cell culture (SILAC) is a simple and robust method for labeling proteins in vivo. Here, we describe the development and application of a five-plex SILAC experiment using four different heavy stable isotopic forms...

  12. Function of MicroRNAs During the Differentiation Process of Brown Adipocytes%MicroRNAs在棕色脂肪细胞分化过程中的作用

    Institute of Scientific and Technical Information of China (English)

    郝美林; 黄英; 黄丽梅; 杨明华; 李琦华; 贾俊静; 赵素梅

    2014-01-01

    MicroRNAs(miRNAs)are small, non-coding regulatory RNAs, which negatively regulate post-transcriptionally gene expression. miRNA plays the role in many biological functions including controlling the developmental timing, regulation of cell differentiation and apoptosis, organ development, fat metabolism. Recent studies indicated that the expression levels of transcriptional factors related genes which were important for the development of brown adipocyte tissue was affected by miRNAs directly or indirectly. This article reviewed the recent progress on the function of miRNA during the differentiation process of brown adipocytes.%MicroRNA(miRNA)是一种非编码的小分子RNA,负性调控转录后基因表达。miRNA在个体时序性发育、细胞增殖分化和凋亡、器官发育、脂肪代谢等许多生物发育过程中起着重要作用。近年来对miRNA的研究证实,miRNA直接或间接影响棕色脂肪组织发育过程中重要转录因子的表达。综述了miRNA调节棕色脂肪细胞分化的最新研究进展。

  13. Using Performance as an Interpretive Strategy in Teaching Robert Browning's "My Last Duchess."

    Science.gov (United States)

    Schevera, Nicholas

    1997-01-01

    Uses role-playing, dramatic monologues, and "tableaux vivant" to interpret Robert Browning's poem "My Last Duchess" in an introductory literature class at Westchester Community College. Notes that performative strategies illustrate connections in the poem that often remain unnoticed on a first reading. (PA)

  14. Measuring respiratory activity of adipocytes and adipose tissues in real time.

    Science.gov (United States)

    Bugge, Anne; Dib, Lea; Collins, Sheila

    2014-01-01

    The realization that obesity and its associated diseases have become one of modern society's major challenges to the health of the world's population has fueled much effort to understand white adipocyte biology and elucidate pathways to increase energy expenditure. One strategy has been to increase the oxidative capacity and activity of the adipocytes themselves. This has the advantage that free fatty acids (FAs) would not be released into the circulation in copious amounts, which can have detrimental effects. This is particularly true for obese individuals, who often already display severe dyslipidemia, putting them at increased risk for cardiovascular diseases. It was recently discovered that adult humans, in addition to infants, possess active brown adipocytes, characterized by expression of the mitochondrial electron gradient dissipater uncoupling protein 1 (UCP1). This has generated renewed interest in finding ways to "convert" or "adapt" white adipocytes into a more brown adipocyte-like state by increasing mitochondrial content and expression of UCP1 and activating UCP1 via lipolysis-mediated free FAs. Another approach to consider is elevating the activity of the not insignificant amount of mitochondria found in white adipocytes. The invention of the XF Flux Analyzer by Seahorse Bioscience has revolutionized this line of research as it allows for real-time measurements of respiration in multiple samples simultaneously. In this chapter, we describe our approaches and experience with employing this technology to study the metabolism of mouse and human primary and immortalized cells and mouse white adipose tissue. © 2014 Elsevier Inc. All rights reserved.

  15. Pharmacological Activation of Thyroid Hormone Receptors Elicits a Functional Conversion of White to Brown Fat

    Directory of Open Access Journals (Sweden)

    Jean Z. Lin

    2015-11-01

    Full Text Available The functional conversion of white adipose tissue (WAT into a tissue with brown adipose tissue (BAT-like activity, often referred to as “browning,” represents an intriguing strategy for combating obesity and metabolic disease. We demonstrate that thyroid hormone receptor (TR activation by a synthetic agonist markedly induces a program of adaptive thermogenesis in subcutaneous WAT that coincides with a restoration of cold tolerance to cold-intolerant mice. Distinct from most other browning agents, pharmacological TR activation dissociates the browning of WAT from activation of classical BAT. TR agonism also induces the browning of white adipocytes in vitro, indicating that TR-mediated browning is cell autonomous. These data establish TR agonists as a class of browning agents, implicate the TRs in the browning of WAT, and suggest a profound pharmacological potential of this action.

  16. MR对小鼠原代棕色脂肪细胞功能的影响%Role of MR in the function of primary brown adipocyte in mouse

    Institute of Scientific and Technical Information of China (English)

    毕建华; 孔小岑; 刘娟; 丁国宪

    2013-01-01

    目的:使用小鼠原代棕色脂肪细胞,研究盐皮质激素受体(mineralocorticoid receptor,MR)对其功能的影响.方法:使用MR激动剂醛固酮、MR拮抗剂螺内酯、糖皮质激素可的松分别作用于小鼠原代棕色脂肪细胞,观察棕色脂肪细胞相关基因的改变.结果:MR的配体(盐皮质激素)可显著增加其功能基因非偶联蛋白1(uncoupling protein-1,UCP1)、细胞死亡诱导DNA碎片因子-α-样效应结合区域蛋白(the cell death-inducing DNA fragmentation factor-α-like effector domain-containing protein,CIDEA)、过氧化酶增殖活化受体α(peroxisome proliferator-activated receptor alpha,PGC1α)的表达,同时也促进分化基因脂肪酸结合蛋白4(fatty acid binding protein 4,FABP4)的表达,相反MR的拮抗剂可抑制棕色脂肪细胞功能基因的表达.另一方面,盐皮质激素还可以协同糖皮质激素共同调节棕色脂肪细胞功能基因UCP1的变化.结论:MR是调控原代棕色脂肪细胞功能的重要因子.%Objective:To investigate the role of mineralocorticoid receptor (MR)in regulating the function of mouse primary brown adipocyte.Methods:The primary brown adipocytes were separated from C57BL/5J mice and induced for differentiation.The expression of genes related to brown fat function,including uncoupling protein-1 (UCP1),the cell death-inducing DNA fragmentation factor-α-like effector,domain-containing protein (CIDEA),peroxisome proliferator-activated receptor alpha (PGC1α) and fatty acid binding protein 4 (FABP4) were observed in MR ligands (aldosterone),MR antagonist (spironolactone) and glucocorticoids (cortisone) treated cells,respectively.Results:Mineralocorticoid could significantly increase the expressions of UCP1,PGC1α and FABP4.Conversely,the expression of UCP1 was suppressed by MR antagonists.Moreover,MR regulated the brown adipocyte function with the interaction of glucocorticoid.Conclusion:MR plays an important role in the function of primary brown

  17. MicroRNA 34a inhibits beige and brown fat formation in obesity in part by suppressing adipocyte fibroblast growth factor 21 signaling and SIRT1 function.

    Science.gov (United States)

    Fu, Ting; Seok, Sunmi; Choi, Sunge; Huang, Zhang; Suino-Powell, Kelly; Xu, H Eric; Kemper, Byron; Kemper, Jongsook Kim

    2014-11-15

    Brown fat generates heat through uncoupled respiration, protecting against hypothermia and obesity. Adult humans have brown fat, but the amounts and activities are substantially decreased in obesity, by unknown mechanisms. Here we show that elevated microRNA 34a (miR-34a) in obesity inhibits fat browning in part by suppressing the browning activators fibroblast growth factor 21 (FGF21) and SIRT1. Lentivirus-mediated downregulation of miR-34a in mice with diet-induced obesity reduced adiposity, improved serum profiles, increased the mitochondrial DNA copy number, and increased oxidative function in adipose tissue in both BALB/c and C57BL/6 mice. Remarkably, downregulation of miR-34a increased coexpression of the beige fat-specific marker CD137 and the browning marker UCP1 in all types of white fat, including visceral fat, and promoted additional browning in brown fat. Mechanistically, downregulation of miR-34a increased expression of the FGF21 receptor components, FGFR1 and βKL, and also that of SIRT1, resulting in FGF21/SIRT1-dependent deacetylation of PGC-1α and induction of the browning genes Ucp1, Pgc-1α, and Prdm16. Importantly, anti-miR-34a-mediated beneficial effects, including decreased adiposity, are likely from multiple tissues, since downregulation of miR-34a also improves hepatic FGF21 signaling and lipid oxidation. This study identifies miR-34a as an inhibitor of beige and brown fat formation, providing a potential target for treating obesity-related diseases.

  18. Adrenergic regulation of cellular plasticity in brown, beige/brite and white adipose tissues.

    Science.gov (United States)

    Ramseyer, Vanesa D; Granneman, James G

    2016-01-01

    The discovery of brown adipose tissue in adult humans along with the recognition of adipocyte heterogeneity and plasticity of white fat depots has renewed the interest in targeting adipose tissue for therapeutic benefit. Adrenergic activation is a well-established means of recruiting catabolic adipocyte phenotypes in brown and white adipose tissues. In this article, we review mechanisms of brown adipocyte recruitment by the sympathetic nervous system and by direct β-adrenergic receptor activation. We highlight the distinct modes of brown adipocyte recruitment in brown, beige/brite, and white adipose tissues, UCP1-independent thermogenesis, and potential non-thermogenic, metabolically beneficial effects of brown adipocytes.

  19. Modulating the Genomic Programming of Adipocytes

    DEFF Research Database (Denmark)

    Loft, Anne; Schmidt, Søren Fisker; Mandrup, Susanne

    2015-01-01

    , an antidiabetic agonist of the key adipocyte transcription factor peroxisome proliferator-activated receptor γ (PPARγ), involves redistribution of PPARγ binding to form browning-selective PPARγ super-enhancers that drive expression of key browning genes. These include genes encoding transcriptional regulators...

  20. Cross-species ChIP-seq studies provide insights into regulatory strategies of PPAR¿ in adipocytes

    DEFF Research Database (Denmark)

    Schmidt, Søren Fisker; Jørgensen, Mette; Sandelin, Albin Gustav

    2012-01-01

    Three recent studies have investigated interspecies retention of binding sites of peroxisome proliferator-activated receptor ¿ (PPAR¿), the master regulator of adipocyte differention, between mouse and human adipocytes. Here we discuss the major findings and demonstrate that retention of binding...

  1. Brown adipogenesis of mouse embryonic stem cells in alginate microstrands

    Science.gov (United States)

    Unser, Andrea Mannarino

    The ability of brown adipocytes (fat cells) to dissipate energy as heat shows great promise for the treatment of obesity and other metabolic disorders. Employing pluripotent stem cells, with an emphasis on directed differentiation, may overcome many issues currently associated with primary fat cell cultures. However, brown adipocytes are difficult to transplant in vivo due to the instability of fat, in terms of necrosis and neovascularization, once injected. Thus, 3D cell culture systems that have the potential to mimic adipogenic microenvironments are needed, not only to advance brown fat implantation, but also to better understand the role of brown adipocytes in treating obesity. To address this need, we created 3D "Brown-Fat-in-Microstrands" by microfluidic synthesis of alginate hydrogel microstrands that encapsulated cells and directly induced cell differentiation into brown adipocytes, using mouse embryonic stem cells (ESCs) as a model of pluripotent stem cells and brown preadipocytes as a positive control. The effect of hydrogel formation parameters on brown adipogenesis was studied, leading to the establishment of "Brown-Fat-in-Microstrands". Brown adipocyte differentiation within microstrands was confirmed by lipid droplet accumulation, immunocytochemistry and qPCR analysis of gene expression of brown adipocyte marker uncoupling protein 1 (UCP1) in addition to adipocyte marker expression. Compared to a 2D approach, 3D differentiated "Brown-Fat-in-Microstrands" exhibited higher level of brown adipocyte marker expression. The functional analysis of "Brown-Fat-in-Microstrands" was attempted by measuring the mitochondrial activity of ESC-differentiated brown adipocytes in 3D using Seahorse XF24 3 Extracellular Flux Analyzer. The ability to create "Brown-Fat-in-Microstrands" from pluripotent stem cells opens up a new arena to understanding brown adipogenesis and its implications in obesity and metabolic disorders.

  2. File list: Unc.Adp.20.AllAg.Brown_preadipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Adp.20.AllAg.Brown_preadipocytes mm9 Unclassified Adipocyte Brown preadipocytes... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Adp.20.AllAg.Brown_preadipocytes.bed ...

  3. File list: Unc.Adp.05.AllAg.Brown_preadipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Adp.05.AllAg.Brown_preadipocytes mm9 Unclassified Adipocyte Brown preadipocytes... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Adp.05.AllAg.Brown_preadipocytes.bed ...

  4. File list: Unc.Adp.10.AllAg.Brown_preadipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Adp.10.AllAg.Brown_preadipocytes mm9 Unclassified Adipocyte Brown preadipocytes... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Adp.10.AllAg.Brown_preadipocytes.bed ...

  5. File list: Unc.Adp.50.AllAg.Brown_preadipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Adp.50.AllAg.Brown_preadipocytes mm9 Unclassified Adipocyte Brown preadipocytes... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Adp.50.AllAg.Brown_preadipocytes.bed ...

  6. Pref-1 preferentially inhibits heat production in brown adipose tissue.

    Science.gov (United States)

    Rakhshandehroo, Maryam; Koppen, Arjen; Kalkhoven, Eric

    2012-05-01

    In mammals there are two types of adipocytes with opposing functions. Brown adipocytes are characterized by a high number of mitochondria and are specialized for heat production (thermogenesis), expressing thermogenic genes such as UCP1 (uncoupling protein 1). White adipocytes, on the other hand, store energy. Although many key regulators in the differentiation of white adipocytes have been established, our current knowledge on the same proteins in brown adipogenesis is lagging behind. One example is Pref-1 (pre-adipocyte factor-1), which maintains white pre-adipocytes in an undifferentiated state, but is only poorly characterized in the brown pre-adipocyte lineage. In this issue of the Biochemical Journal, Armengol et al. now shed new light on the role and regulation of Pref-1 in brown pre-adipocytes. First, Pref-1 specifically inhibits the thermogenic gene programme in brown pre-adipocytes. Secondly, they identified the transcription factor C/EBPδ (CCAAT/enhancer-binding protein δ) as a direct positive regulator of Pref-1 expression, whereas this protein does not fulfil this role in white adipogenesis. Taken together, these findings indicate that specific manipulation of brown adipocyte differentiation and/or function without interfering with their white adipocyte counterparts may be possible, which may open up new therapeutic ways to combat obesity-associated health problems.

  7. 白色脂肪组织褐变的抗肥胖作用研究进展%Progress:Anti-obesity Role of White Adipocyte Tissue Browning

    Institute of Scientific and Technical Information of China (English)

    陈士勇; 王欣; 付建飞; 张慧琴; 邹祖全; 张晓宏

    2014-01-01

    肥胖在发达国家和发展中国家广泛流行,成为世界性公共卫生问题。寻找安全、有效的措施拮抗肥胖形成已势在必行。近年来的研究证实了成年人体内存在功能性褐色脂肪组织,但是其活性却呈现随年龄增加而递减的趋势。与褐色脂肪组织不同,白色脂肪组织人体内分布广泛。最近的研究证实白色脂肪组织具有很强的可塑性,在特定情况下能够呈现褐色脂肪表型、获得褐色脂肪的产热活性,并证实某些信号因子以及某些植物化学物可介导白色脂肪组织褐变。%Obesity is a public health problem worldwide, and deserves urgent attention in healthcare sectors. Recent studies show that there are active brown adipose tissues in human adults, but their mass and activities will decrease with aging. In contrast, white adipose tissues are distributed widely in the body. Most importantly, there has been great advancement in studying the function of white adipose tissue. The recent finding suggests that white adipose tissue has strong plasticity, and can get brown phenotype and possess capacity of thermogenesis under some conditions. Besides, some signal factors and phytochemicals are found to be able to mediate the browning of white adipose tissue. In the article, the breakthroughs concerned are reviewed with a view of providing some practical insights for obesity treatment and control.

  8. Brown Adipose Tissue Growth and Development

    Directory of Open Access Journals (Sweden)

    Michael E. Symonds

    2013-01-01

    Full Text Available Brown adipose tissue is uniquely able to rapidly produce large amounts of heat through activation of uncoupling protein (UCP 1. Maximally stimulated brown fat can produce 300 watts/kg of heat compared to 1 watt/kg in all other tissues. UCP1 is only present in small amounts in the fetus and in precocious mammals, such as sheep and humans; it is rapidly activated around the time of birth following the substantial rise in endocrine stimulatory factors. Brown adipose tissue is then lost and/or replaced with white adipose tissue with age but may still contain small depots of beige adipocytes that have the potential to be reactivated. In humans brown adipose tissue is retained into adulthood, retains the capacity to have a significant role in energy balance, and is currently a primary target organ in obesity prevention strategies. Thermogenesis in brown fat humans is environmentally regulated and can be stimulated by cold exposure and diet, responses that may be further modulated by photoperiod. Increased understanding of the primary factors that regulate both the appearance and the disappearance of UCP1 in early life may therefore enable sustainable strategies in order to prevent excess white adipose tissue deposition through the life cycle.

  9. Brown adipose tissue growth and development.

    Science.gov (United States)

    Symonds, Michael E

    2013-01-01

    Brown adipose tissue is uniquely able to rapidly produce large amounts of heat through activation of uncoupling protein (UCP) 1. Maximally stimulated brown fat can produce 300 watts/kg of heat compared to 1 watt/kg in all other tissues. UCP1 is only present in small amounts in the fetus and in precocious mammals, such as sheep and humans; it is rapidly activated around the time of birth following the substantial rise in endocrine stimulatory factors. Brown adipose tissue is then lost and/or replaced with white adipose tissue with age but may still contain small depots of beige adipocytes that have the potential to be reactivated. In humans brown adipose tissue is retained into adulthood, retains the capacity to have a significant role in energy balance, and is currently a primary target organ in obesity prevention strategies. Thermogenesis in brown fat humans is environmentally regulated and can be stimulated by cold exposure and diet, responses that may be further modulated by photoperiod. Increased understanding of the primary factors that regulate both the appearance and the disappearance of UCP1 in early life may therefore enable sustainable strategies in order to prevent excess white adipose tissue deposition through the life cycle.

  10. Obesity Beige adipocytes-will they beat obesity?

    DEFF Research Database (Denmark)

    Sandholt, Camilla H.; Pedersen, Oluf.

    2015-01-01

    The mechanistic link between the FTO locus and risk of obesity has remained elusive. However, a new study presents compelling evidence suggesting that the browning of white adipocytes into beige adipocytes (together with regulation of thermogenesis), might be an important and potentially modifiable...... pathway for development of obesity therapeutics....

  11. Evidence for two types of brown adipose tissue in humans.

    Science.gov (United States)

    Lidell, Martin E; Betz, Matthias J; Dahlqvist Leinhard, Olof; Heglind, Mikael; Elander, Louise; Slawik, Marc; Mussack, Thomas; Nilsson, Daniel; Romu, Thobias; Nuutila, Pirjo; Virtanen, Kirsi A; Beuschlein, Felix; Persson, Anders; Borga, Magnus; Enerbäck, Sven

    2013-05-01

    The previously observed supraclavicular depot of brown adipose tissue (BAT) in adult humans was commonly believed to be the equivalent of the interscapular thermogenic organ of small mammals. This view was recently disputed on the basis of the demonstration that this depot consists of beige (also called brite) brown adipocytes, a newly identified type of brown adipocyte that is distinct from the classical brown adipocytes that make up the interscapular thermogenic organs of other mammals. A combination of high-resolution imaging techniques and histological and biochemical analyses showed evidence for an anatomically distinguishable interscapular BAT (iBAT) depot in human infants that consists of classical brown adipocytes, a cell type that has so far not been shown to exist in humans. On the basis of these findings, we conclude that infants, similarly to rodents, have the bona fide iBAT thermogenic organ consisting of classical brown adipocytes that is essential for the survival of small mammals in a cold environment.

  12. Infanticide as a male reproductive strategy has a nutritive risk effect in brown bears.

    Science.gov (United States)

    Steyaert, S M J G; Reusch, C; Brunberg, S; Swenson, J E; Hackländer, K; Zedrosser, A

    2013-10-23

    Behavioural strategies to reduce predation risk can incur costs, which are often referred to as risk effects. A common strategy to avoid predation is spatio-temporal avoidance of predators, in which prey typically trade optimal resources for safety. Analogous with predator-prey theory, risk effects should also arise in species with sexually selected infanticide (SSI), in which females with dependent offspring avoid infanticidal males. SSI can be common in brown bear (Ursus arctos) populations and explains spatio-temporal segregation among reproductive classes. Here, we show that in a population with SSI, females with cubs-of-the-year had lower quality diets than conspecifics during the SSI high-risk period, the mating season. After the mating season, their diets were of similar quality to diets of their conspecifics. Our results suggest a nutritive risk effect of SSI, in which females with cubs-of-the-year alter their resource selection and trade optimal resources for offspring safety. Such risk effects can add to female costs of reproduction and may be widespread among species with SSI.

  13. Related Regulating Factors of White Adipocytes Browning%白色脂肪细胞棕色化的相关调控因素

    Institute of Scientific and Technical Information of China (English)

    冉红星

    2014-01-01

    哺乳动物主要含有两种脂肪组织:白色脂肪组织(white adipose tissue,WAT)和棕色脂肪组织( brown adipose tissue,BAT).前者为贮存能量,后者在维持体温和能量平衡方面发挥重要作用.研究发现,特定部位的白色脂肪,在适当的刺激下可以发生褐变,即白色脂肪转化为棕色脂肪样.其特点是线粒体中的解耦联蛋白 1(uncoupling protein 1,UCP1)表达增加、多腔室脂滴的存在和线粒体数量的增多.这些褐变脂肪细胞的基因表达谱介于白色脂肪细胞和经典的棕色脂肪细胞之间,于是提出了"白色脂肪细胞棕色化"的概念.其褐变过程是如何进行的,目前已成为热门研究话题.由于白色脂肪褐变显示了能量平衡由能量储存转为能量支出,因而成为治疗日益严重和流行的肥胖和代谢综合征的新目标.文章对褐变中起作用的转录因子、多种蛋白和分泌因子进行了总结.

  14. Expression of a cDNA isolated from rat brown adipose tissue and heart identifies the product as the muscle isoform of carnitine palmitoyltransferase I (M-CPT I). M-CPT I is the predominant CPT I isoform expressed in both white (epididymal) and brown adipocytes.

    Science.gov (United States)

    Esser, V; Brown, N F; Cowan, A T; Foster, D W; McGarry, J D

    1996-03-22

    We set out to determine if the cDNA encoding a carnitine palmitoyltransferase (CPT)-like protein recently isolated from rat brown adipose tissue (BAT) by Yamazaki et al. (Yamazaki, N., Shinohara, Y., Shima, A., and Terada, H. (1995) FEBS Lett. 363, 41-45) actually encodes the muscle isoform of mitochondrial CPT I (M-CPT I). To this end, a cDNA essentially identical to the original BAT clone was isolated from a rat heart library. When expressed in COS cells, the novel cDNA and our previously described cDNA for rat liver CPT I (L-CPT I) gave rise to products with the same kinetic characteristics (sensitivity to malonyl-CoA and Km for carnitine) as CPT I in skeletal muscle and liver mitochondria, respectively. When labeled with [3H]etomoxir, recombinant L-CPT I and putative M-CPT I, although having approximately the same predicated masses (88.2 kDa), migrated differently on SDS gels, as did CPT I from liver and muscle mitochondria. The same was true for the products of in vitro transcription and translation of the L-CPT I and putative M-CPT I cDNAs. We conclude that the BAT cDNA does in fact encode M-CPT I. Northern blots using L- and M-CPT I cDNA probes revealed the presence of L-CPT I mRNA in liver and heart and its absence from skeletal muscle and BAT. M-CPT I mRNA, which was absent from liver, was readily detected in skeletal muscle and was particularly strong in heart and BAT. Whereas the signal for L-CPT I was more abundant than that for M-CPT I in RNA isolated from whole epididymal fat pad, this was reversed in purified adipocytes from this source. These findings, coupled with the kinetic properties and migration profiles on SDS gels of CPT I in brown and white adipocytes, indicate that the muscle form of the enzyme is the dominant, if not exclusive, species in both cell types.

  15. Brown Fat and Browning for the Treatment of Obesity and Related Metabolic Disorders

    Directory of Open Access Journals (Sweden)

    So Hun Kim

    2016-02-01

    Full Text Available Brown fat is a specialized fat depot that can increase energy expenditure and produce heat. After the recent discovery of the presence of active brown fat in human adults and novel transcription factors controlling brown adipocyte differentiation, the field of the study of brown fat has gained great interest and is rapidly growing. Brown fat expansion and/or activation results in increased energy expenditure and a negative energy balance in mice and limits weight gain. Brown fat is also able to utilize blood glucose and lipid and results in improved glucose metabolism and blood lipid independent of weight loss. Prolonged cold exposure and beta adrenergic agonists can induce browning of white adipose tissue. The inducible brown adipocyte, beige adipocyte evolving by thermogenic activation of white adipose tissue have different origin and molecular signature from classical brown adipocytes but share the characteristics of high mitochondria content, UCP1 expression and thermogenic capacity when activated. Increasing browning may also be an efficient way to increase whole brown fat activity. Recent human studies have shown possibilities that findings in mice can be reproduced in human, making brown fat a good candidate organ to treat obesity and its related disorders.

  16. GLP-1受体激动剂对小鼠棕色脂肪细胞基因表达和细胞分化的研究%Research on glucagon-like peptide-1 receptor agonist on the function and differentiation of brown adipocytes in mice

    Institute of Scientific and Technical Information of China (English)

    沈山梅; 石欢; 毕艳; 冯文焕; 王维敏; 金玺; 韩小娟; 胡明玥; 朱大龙

    2013-01-01

    Objective To investigate the effects of glucagon-like peptide-1 (GLP-1) receptor agonist on the function and differentiation of brown adipocytes in mice.Methods Primary brown adipocytes in mice were cultivated in vitro.Before the induction,brown adipocytes were assigned to four groups:GLP-1 10-8mol/L group,GLP-1 10-9mol/L group,L-NAME 10-3 mol/L group,and control group.Finally,adipocytes were put under morphological observation.The expression levels of genes of brown adipocytes in different groups were detected by RT-PCR.The single factor analysis was used for data analysis.Results The lipid droplets of brown adipocytes in GLP-1 group increased significantly compared with the control group under morphological observation.The expressions of specific genes [uncoupling protein 1 (UCP1),cell death-inducing DFFA (DNA fragmentation factor a)-like effector a (Cidea),peroxisome proliferator-activated receptor γcoactive 1α (PGC1-α)],differentiation genes [PRD1-BF1-RIZ1 homologous domain containing 16 (PRDM16),peroxisome proliferators-activated receptor-γ(PPAR-γ)],nitric oxide pathway genes [endothelial nitric oxide synthase (eNOS),inducible nitric oxide synthase (iNOS)] in brown adipocytes in GLP-1 group were significantly increased as compared with the control group,F values were 17.36,29.57,66.76,13.78,4.14,105.47,346.57 respectively(all P<0.05).Conclusions GLP-1 receptor agonist may improve the differentiation and function of brown adipocytes in mice,thereby enhance the function and induce the differentiation of brown adipocytes,the effect is more evident in high concentration of GLP-1.%目的 研究胰升糖素样肽1(GLP-1)受体激动剂对小鼠棕色脂肪细胞功能基因表达和分化的作用.方法 体外培养小鼠棕色脂肪前体细胞,诱导分化前分4组:GLP-1(10-8 mol/L)组、GLP-1(10-9moL/L)组、L-NAME(一氧化氮合酶抑制剂,10-3mol/L)组和对照组.干预结束后对细胞进行形态学观察研究,应用荧光定量PCR检测棕色

  17. Perilipin overexpression in white adipose tissue induces a brown fat-like phenotype.

    Directory of Open Access Journals (Sweden)

    Takashi Sawada

    Full Text Available BACKGROUND: Perilipin A (PeriA exclusively locates on adipocyte lipid droplets and is essential for lipid storage and lipolysis. Previously, we reported that adipocyte specific overexpression of PeriA caused resistance to diet-induced obesity and resulted in improved insulin sensitivity. In order to better understand the biological basis for this observed phenotype, we performed additional studies in this transgenic mouse model. METHODOLOGY AND PRINCIPAL FINDINGS: When compared to control animals, whole body energy expenditure was increased in the transgenic mice. Subsequently, we performed DNA microarray analysis and real-time PCR on white adipose tissue. Consistent with the metabolic chamber data, we observed increased expression of genes associated with fatty acid β-oxidation and heat production, and a decrease in the genes associated with lipid synthesis. Gene expression of Pgc1a, a regulator of fatty acid oxidation and Ucp1, a brown adipocyte specific protein, was increased in the white adipose tissue of the transgenic mice. This observation was subsequently verified by both Western blotting and histological examination. Expression of RIP140, a regulator of white adipocyte differentiation, and the lipid droplet protein FSP27 was decreased in the transgenic mice. Importantly, FSP27 has been shown to control gene expression of these crucial metabolic regulators. Overexpression of PeriA in 3T3-L1 adipocytes also reduced FSP27 expression and diminished lipid droplet size. CONCLUSIONS: These findings demonstrate that overexpression of PeriA in white adipocytes reduces lipid droplet size by decreasing FSP27 expression and thereby inducing a brown adipose tissue-like phenotype. Our data suggest that modulation of lipid droplet proteins in white adipocytes is a potential therapeutic strategy for the treatment of obesity and its related disorders.

  18. The Progression of Resveratrol Induced Browning of white Adipocytes%白藜芦醇诱导白色脂肪组织棕色化的研究进展

    Institute of Scientific and Technical Information of China (English)

    于鹏; 张慧

    2015-01-01

    哺乳动物体内的棕色脂肪组织(brown adipose tissue,BAT)与主要储存能量的白色脂肪组织(white adipose tissue,WAT)相比,BAT因含有丰富线粒体解偶联蛋白1(uncoupling protein-1,UCP1)而拥有非颤栗产热的能力."米色脂肪细胞"(Beige Adipocytes)虽具有区别白色脂肪细胞和棕色脂肪细胞的分化路径,但在机体中发挥着与棕色脂肪同样的生理作用,具有极高的代谢率并发挥产热作用,激活米色脂肪中棕色脂肪特异性表达基因对白色脂肪棕色化起着重要作用.白藜芦醇(Resveratrol,RSV)激活脂肪组织沉默信号调节因子1(Silent information regulator 1,SIRT1),SIRT1通过配体依赖方式去乙酰化过氧化物酶体增殖体激活受体γ(Peroxisome proliferator activated receptor γ,PPARγ),抑制过氧化物酶体增殖物激活受体γ辅助激活因子-1α (peroxisome proliferator activated receptorγ coactivator-1α,PGC-1α)的去乙酰化作用及其与PPARγ的交互作用等减少脂肪生成和脂质蓄积,促进脂肪分解速率,诱导线粒体生成,提高线粒体生物氧化功能,线粒体解偶联蛋白1 (uncoupling protein 1,UCP-1)表达增加等进而诱导白色脂肪棕色化的可能机制,探讨白藜芦醇诱导白色脂肪棕色化的信号通路,为今后的研究作出展望.

  19. Can Brown Fat Win the Battle Against White Fat?

    Science.gov (United States)

    Elattar, Sawsan; Satyanarayana, Ande

    2015-10-01

    A rapid growth in the overweight and obese population in the last few decades suggest that the current diet, exercise, awareness or drug strategies are still not effectively restraining the obesity epidemic. Obesity results from increased energy intake, and the body's energy balance shifts towards energy abundance. Therefore, current research is focused on developing new strategies aimed at increasing energy expenditure. As a result, brown adipose tissue (BAT) is receiving tremendous attention since the major function of BAT is to dissipate energy as heat. For example, mouse models that have increased BAT activity or increased numbers of brown-like adipocytes within the white adipose tissue (WAT) are lean and protected from obesity. Alternatively, mouse models that lack BAT activity are more susceptible to age and diet-induced obesity. However, a significant loss of BAT mass during the natural growth process in humans has created enormous challenges in effectively utilizing this tissue to increase energy expenditure. New strategies are primarily focused on expanding the BAT mass and/or activating the existing BAT. In this regard, recent finding that expression of early B cell factor-2 (Ebf2) reprograms the white pre-adipocytes into brown adipocytes is a significant break-through in developing BAT-mediated strategies to treat obesity. Here we review the major biological functions of WAT and BAT, which play critical but opposing roles in the energy spectrum, energy storage versus energy expenditure, and we evaluate whether activation and/or expansion of BAT is practically achievable to treat obesity in humans.

  20. Cell autonomous lipin 1 function is essential for development and maintenance of white and brown adipose tissue

    NARCIS (Netherlands)

    Nadra, K.; Medard, J.J.; Mul, J.D.; Han, G.S.; Gres, S.; Pende, M.; Metzger, D.; Chambon, P.; Cuppen, E.; Saulnier-Blache, J.S.; Carman, G.M.; Desvergne, B.; Chrast, R.

    2012-01-01

    Through analysis of mice with spatially and temporally restricted inactivation of Lpin1, we characterized its cell autonomous function in both white (WAT) and brown (BAT) adipocyte development and maintenance. We observed that the lipin 1 inactivation in adipocytes of

  1. Intricate Transcriptional Networks of Classical Brown and Beige Fat Cells.

    Science.gov (United States)

    Park, Jun Hong; Hur, Wonhee; Lee, Sean Bong

    2015-01-01

    Brown adipocytes are a specialized cell type that is critical for adaptive thermogenesis, energy homeostasis, and metabolism. In response to cold, both classical brown fat and the newly identified "beige" or "brite" cells are activated by β-adrenergic signaling and catabolize stored lipids and carbohydrates to produce heat via UCP1. Once thought to be non-existent in adults, recent studies have discovered active classical brown and beige fat cells in humans, thus reinvigorating interest in brown and beige adipocytes. This review will focus on the newly discovered transcription factors and microRNAs that specify and orchestrate the classical brown and beige fat cell development.

  2. Changes in expression levels of brown adipocyte differentiation associated with key genes and reference controls during adipogenesis%棕色脂肪细胞分化过程中关键基因及常用内参表达水平变化

    Institute of Scientific and Technical Information of China (English)

    孙亚洲; 封在李; 张艳艳; 王星云; 周亚慧; 李沄; 崔县伟; 郭学鹏; 王家勤

    2016-01-01

    目的 探究棕色脂肪细胞分化过程中关键基因以及参照基因随分化进程的表达变化趋势.方法 根据随机数字表法随机选取20只4周龄雄性C57BL/6J小鼠,提取肩胛间区棕色脂肪组织.以高糖DMEM培养原代棕色前体脂肪细胞,以“鸡尾酒法”诱导培养基(含0.5 mmol/L异丁基甲基黄嘌呤、5 mmol/L地塞米松、320 nmol/L胰岛素、1 nmol/L三碘甲状腺原氨酸和0.125 mmol/L吲哚美辛)诱导分化.Trizol裂解法提取分化过程中(0、2、4、6d)棕色脂肪细胞总RNA,琼脂糖凝胶电泳验证总RNA质量.油红O染色,检测棕色脂肪细胞成熟情况,免疫荧光鉴定棕色脂肪细胞成熟标志物UCP1表达水平.实时荧光定量聚合酶链反应(RT-qPCR)法比较在棕色脂肪细胞中参照基因(GAPDH、β-actin、18S和PPIA)表达水平的恒定性,并检测棕色脂肪分化关键基因(UCPI、PRDM16、PGC-1α、EBF2、PPARγ和Cidea)的表达水平.结果 1.诱导第6天可见棕色脂肪细胞内密布细小脂滴,UCP1表达水平较高.2.琼脂糖凝胶电泳检测RNA质量,可见3条明亮带,提示RNA质量合格.3.在小鼠棕色脂肪分化过程中PPIA的表达水平相对恒定,可作为小鼠棕色脂肪分化合适的内参.4.棕色脂肪能量代谢相关基因UCP1、PRDM16、PGC-1α、EBF2、PPARγ和Cidea随着分化天数(0、2、4、6d)的增加表达量显著增加,差异有统计学意义(P均<0.05).结论 原代棕色脂肪细胞分化过程中,内参基因PPIA表达恒定,是合适的内参基因.原代棕色分化关键基因UCP1、PRDM16、PGC-1α、EBF2、PPARγ和Cidea可作为合适的棕色脂肪细胞成熟标志基因.%Objective To investigate the expression changes in the key differentiation-associated genes and reference genes during the progress of primary brown phagocyte adipocytes.Methods Twenty 4-week-old male C57BL/6J mice were selected randomly and brown adipose tissues were extracted from interscapular area.These brown preadipocytes

  3. Metabolic programming of a beige adipocyte phenotype by genistein

    Science.gov (United States)

    Aziz, Sadat A.; Wakeling, Luisa A.; Miwa, Satomi; Alberdi, Goiuri; Hesketh, John E.

    2016-01-01

    Scope Promoting the development of brown or beige adipose tissue may protect against obesity and related metabolic features, and potentially underlies protective effects of genistein in mice. Methods and results We observed that application of genistein to 3T3‐L1 adipocytes changed the lipid distribution from large droplets to a multilocular distribution, reduced mRNAs indicative of white adipocytes (ACC, Fasn, Fabp4, HSL, chemerin, and resistin) and increased mRNAs that are a characteristic feature of brown/beige adipocytes (CD‐137 and UCP1). Transcripts with a role in adipocyte differentiation (Cebpβ, Pgc1α, Sirt1) peaked at different times after application of genistein. These responses were not affected by the estrogen receptor (ER) antagonist fulvestrant, revealing that this action of genistein is not through the classical ER pathway. The Sirt1 inhibitor Ex‐527 curtailed the genistein‐mediated increase in UCP1 and Cebpβ mRNA, revealing a role for Sirt1 in mediating the effect. Baseline oxygen consumption and the proportional contribution of proton leak to maximal respiratory capacity was greater for cells exposed to genistein, demonstrating greater mitochondrial uncoupling. Conclusions We conclude that genistein acts directly on adipocytes or on adipocyte progenitor cells to programme the cells metabolically to adopt features of beige adipocytes. Thus, this natural dietary agent may protect against obesity and related metabolic disease. PMID:27670404

  4. Role of Brown Fat in Lipoprotein Metabolism and Atherosclerosis.

    Science.gov (United States)

    Hoeke, Geerte; Kooijman, Sander; Boon, Mariëtte R; Rensen, Patrick C N; Berbée, Jimmy F P

    2016-01-08

    Atherosclerosis, for which hyperlipidemia is a major risk factor, is the leading cause of morbidity and mortality in Western society, and new therapeutic strategies are highly warranted. Brown adipose tissue (BAT) is metabolically active in human adults. Although positron emission tomography-computed tomography using a glucose tracer is the golden standard to visualize and quantify the volume and activity of BAT, it has become clear that activated BAT combusts fatty acids rather than glucose. Here, we review the role of brown and beige adipocytes in lipoprotein metabolism and atherosclerosis, with evidence derived from both animal and human studies. On the basis of mainly data from animal models, we propose a model in which activated brown adipocytes use their intracellular triglyceride stores to generate fatty acids for combustion. BAT rapidly replenishes these stores by internalizing primarily lipoprotein triglyceride-derived fatty acids, generated by lipoprotein lipase-mediated hydrolysis of triglycerides, rather than by holoparticle uptake. As a consequence, BAT activation leads to the generation of lipoprotein remnants that are subsequently cleared via the liver provided that an intact apoE-low-density lipoprotein receptor pathway is present. Through these mechanisms, BAT activation reduces plasma triglyceride and cholesterol levels and attenuates diet-induced atherosclerosis development. Initial studies suggest that BAT activation in humans may also reduce triglyceride and cholesterol levels, but potential antiatherogenic effects should be assessed in future studies. © 2016 American Heart Association, Inc.

  5. Brown adipose tissue and its therapeutic potential.

    Science.gov (United States)

    Lidell, M E; Betz, M J; Enerbäck, S

    2014-10-01

    Obesity and related diseases are a major cause of human morbidity and mortality and constitute a substantial economic burden for society. Effective treatment regimens are scarce, and new therapeutic targets are needed. Brown adipose tissue, an energy-expending tissue that produces heat, represents a potential therapeutic target. Its presence is associated with low body mass index, low total adipose tissue content and a lower risk of type 2 diabetes mellitus. Knowledge about the development and function of thermogenic adipocytes in brown adipose tissue has increased substantially in the last decade. Important transcriptional regulators have been identified, and hormones able to modulate the thermogenic capacity of the tissue have been recognized. Intriguingly, it is now clear that humans, like rodents, possess two types of thermogenic adipocytes: the classical brown adipocytes found in the interscapular brown adipose organ and the so-called beige adipocytes primarily found in subcutaneous white adipose tissue after adrenergic stimulation. The presence of two distinct types of energy-expending adipocytes in humans is conceptually important because these cells might be stimulated and recruited by different signals, raising the possibility that they might be separate potential targets for therapeutic intervention. In this review, we will discuss important features of the energy-expending brown adipose tissue and highlight those that may serve as potential targets for pharmacological intervention aimed at expanding the tissue and/or enhancing its function to counteract obesity.

  6. Shades of Brown: A Model for Thermogenic Fat

    Directory of Open Access Journals (Sweden)

    Jon Michael Dempersmier

    2015-05-01

    Full Text Available Brown adipose tissue (BAT is specialized to burn fuels to perform thermogenesis in defense of body temperature against cold. Recent discovery of metabolically active and relevant amounts of BAT in adult humans have made it a potentially attractive target for development of anti-obesity therapeutics. There are two types of brown adipocytes: classical brown adipocytes as well as brown adipocyte-like cells, so called beige/brite cells, that arise in white adipose tissue in response to cold and hormonal stimuli. These cells may derive from distinct origins, and while functionally similar, have different gene signatures. Here, we highlight recent advances in the understanding of brown and beige/brite adipocytes as well as transcriptional regulation for development and function of murine brown and beige/brite adipocytes focusing on EBF2, IRF4 and ZFP516, in addition to PRDM16 as a coregulator. We also discuss hormonal regulation of brown and beige/brite adipocytes including several factors secreted from various tissues, including BMP7, FGF21 and irisin, as well as those from BAT itself, such as Nrg4 and adenosine.

  7. Phosphoproteomics Identifies CK2 as a Negative Regulator of Beige Adipocyte Thermogenesis and Energy Expenditure.

    Science.gov (United States)

    Shinoda, Kosaku; Ohyama, Kana; Hasegawa, Yutaka; Chang, Hsin-Yi; Ogura, Mayu; Sato, Ayaka; Hong, Haemin; Hosono, Takashi; Sharp, Louis Z; Scheel, David W; Graham, Mark; Ishihama, Yasushi; Kajimura, Shingo

    2015-12-01

    Catecholamines promote lipolysis both in brown and white adipocytes, whereas the same stimuli preferentially activate thermogenesis in brown adipocytes. Molecular mechanisms for the adipose-selective activation of thermogenesis remain poorly understood. Here, we employed quantitative phosphoproteomics to map global and temporal phosphorylation profiles in brown, beige, and white adipocytes under β3-adrenenoceptor activation and identified kinases responsible for the adipose-selective phosphorylation profiles. We found that casein kinase2 (CK2) activity is preferentially higher in white adipocytes than brown/beige adipocytes. Genetic or pharmacological blockade of CK2 in white adipocytes activates the thermogenic program in response to cAMP stimuli. Such activation is largely through reduced CK2-mediated phosphorylation of class I HDACs. Notably, inhibition of CK2 promotes beige adipocyte biogenesis and leads to an increase in whole-body energy expenditure and ameliorates diet-induced obesity and insulin resistance. These results indicate that CK2 is a plausible target to rewire the β3-adrenenoceptor signaling cascade that promotes thermogenesis in adipocytes.

  8. Adipocyte-specific deletion of mTOR inhibits adipose tissue development and causes insulin resistance in mice.

    Science.gov (United States)

    Shan, Tizhong; Zhang, Pengpeng; Jiang, Qinyang; Xiong, Yan; Wang, Yizhen; Kuang, Shihuan

    2016-09-01

    The in vivo role of mechanistic target of rapamycin (mTOR) in the development and function of adipose tissue, especially brown adipose tissue (BAT), is not well understood. Here, we aimed to assess the effect of mTOR (also known as Mtor) knockout on adipose tissues and systemic energy metabolism. We generated adipocyte-specific mTOR-knockout mice (Adipoq-mTOR) by crossing adiponectin-Cre (Adipoq-Cre) mice with mTOR (flox/flox) mice. The mice were then subjected to morphological, physiological (indirect calorimetry, glucose and insulin tolerance tests) and gene expression analyses to determine the role of mTOR in adipose tissues. We provide in vivo evidence that mTOR is essential for adipose tissue development and growth. Deletion of mTOR decreased the mass of both BAT and white adipose tissues (WAT) and induced browning of WAT. In addition, ablation of mTOR in adipose tissues caused insulin resistance and fatty liver in the Adipoq-mTOR mice. Furthermore, mTOR was required for adipocyte differentiation in vivo and activation of PPARγ ameliorated the differentiation deficiency of the mTOR-null adipocytes. Our findings demonstrate that mTOR is a critical regulator of adipogenesis and systemic energy metabolism. Our study provides key insights into the role of mTOR in adipose tissues; such knowledge may facilitate the development of novel strategies with which to treat obesity and related metabolic diseases.

  9. Browning and thermogenic programing of adipose tissue.

    Science.gov (United States)

    Kiefer, Florian W

    2016-08-01

    The view of adipose tissue as solely a fat storing organ has changed significantly over the past two decades with the discoveries of numerous adipocyte-secreted factors, so called adipokines, and their endocrine functions throughout the body. The newest chapter added to this story is the finding that adipose tissue is also a thermogenic organ contributing to energy expenditure through actions of specialized, heat-producing brown or beige adipocytes. In contrast to bone fide brown adipocytes, beige cells develop within white fat depots in response to various stimuli such as prolonged cold exposure, underscoring the great thermogenic plasticity of adipose tissue. The energy dissipating properties of beige and/or brown adipocytes hold great promise as a novel therapeutic concept against obesity and related complications. Hence, identifying the specific thermogenic adipocyte populations in humans and their pathways of activation are key milestones of current metabolism research. Here we will discuss the recent advances in the understanding of the molecular and physiological mechanisms of adipose tissue browning. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Dynamic regulation of genes involved in mitochondrial DNA replication and transcription during mouse brown fat cell differentiation and recruitment.

    Science.gov (United States)

    Murholm, Maria; Dixen, Karen; Qvortrup, Klaus; Hansen, Lillian H L; Amri, Ez-Zoubir; Madsen, Lise; Barbatelli, Giorgio; Quistorff, Bjørn; Hansen, Jacob B

    2009-12-24

    Brown adipocytes are specialised in dissipating energy through adaptive thermogenesis, whereas white adipocytes are specialised in energy storage. These essentially opposite functions are possible for two reasons relating to mitochondria, namely expression of uncoupling protein 1 (UCP1) and a remarkably higher mitochondrial abundance in brown adipocytes. Here we report a comprehensive characterisation of gene expression linked to mitochondrial DNA replication, transcription and function during white and brown fat cell differentiation in vitro as well as in white and brown fat, brown adipose tissue fractions and in selected adipose tissues during cold exposure. We find a massive induction of the majority of such genes during brown adipocyte differentiation and recruitment, e.g. of the mitochondrial transcription factors A (Tfam) and B2 (Tfb2m), whereas only a subset of the same genes were induced during white adipose conversion. In addition, PR domain containing 16 (PRDM16) was found to be expressed at substantially higher levels in brown compared to white pre-adipocytes and adipocytes. We demonstrate that forced expression of Tfam but not Tfb2m in brown adipocyte precursor cells promotes mitochondrial DNA replication, and that silencing of PRDM16 expression during brown fat cell differentiation blunts mitochondrial biogenesis and expression of brown fat cell markers. Using both in vitro and in vivo model systems of white and brown fat cell differentiation, we report a detailed characterisation of gene expression linked to mitochondrial biogenesis and function. We find significant differences in differentiating white and brown adipocytes, which might explain the notable increase in mitochondrial content observed during brown adipose conversion. In addition, our data support a key role of PRDM16 in triggering brown adipocyte differentiation, including mitochondrial biogenesis and expression of UCP1.

  11. Dynamic regulation of genes involved in mitochondrial DNA replication and transcription during mouse brown fat cell differentiation and recruitment.

    Directory of Open Access Journals (Sweden)

    Maria Murholm

    Full Text Available BACKGROUND: Brown adipocytes are specialised in dissipating energy through adaptive thermogenesis, whereas white adipocytes are specialised in energy storage. These essentially opposite functions are possible for two reasons relating to mitochondria, namely expression of uncoupling protein 1 (UCP1 and a remarkably higher mitochondrial abundance in brown adipocytes. METHODOLOGY/PRINCIPAL FINDINGS: Here we report a comprehensive characterisation of gene expression linked to mitochondrial DNA replication, transcription and function during white and brown fat cell differentiation in vitro as well as in white and brown fat, brown adipose tissue fractions and in selected adipose tissues during cold exposure. We find a massive induction of the majority of such genes during brown adipocyte differentiation and recruitment, e.g. of the mitochondrial transcription factors A (Tfam and B2 (Tfb2m, whereas only a subset of the same genes were induced during white adipose conversion. In addition, PR domain containing 16 (PRDM16 was found to be expressed at substantially higher levels in brown compared to white pre-adipocytes and adipocytes. We demonstrate that forced expression of Tfam but not Tfb2m in brown adipocyte precursor cells promotes mitochondrial DNA replication, and that silencing of PRDM16 expression during brown fat cell differentiation blunts mitochondrial biogenesis and expression of brown fat cell markers. CONCLUSIONS/SIGNIFICANCE: Using both in vitro and in vivo model systems of white and brown fat cell differentiation, we report a detailed characterisation of gene expression linked to mitochondrial biogenesis and function. We find significant differences in differentiating white and brown adipocytes, which might explain the notable increase in mitochondrial content observed during brown adipose conversion. In addition, our data support a key role of PRDM16 in triggering brown adipocyte differentiation, including mitochondrial biogenesis and

  12. Adipocyte Dynamics and Reversible Metabolic Syndrome in Mice with an Inducible Adipocyte-Specific Deletion of the Insulin Receptor.

    Science.gov (United States)

    Sakaguchi, Masaji; Fujisaka, Shiho; Cai, Weikang; Winnay, Jonathon N; Konishi, Masahiro; O'Neill, Brian T; Li, Mengyao; García-Martín, Rubén; Takahashi, Hirokazu; Hu, Jiang; Kulkarni, Rohit N; Kahn, C Ronald

    2017-02-07

    Insulin and IGF1 signaling are important for adipose tissue development and function; however, their role in mature adipocytes is unclear. Mice with a tamoxifen-inducible knockout of insulin and/or IGF1 receptors (IR/IGF1R) demonstrate a rapid loss of white and brown fat due to increased lipolysis and adipocyte apoptosis. This results in insulin resistance, glucose intolerance, hepatosteatosis, islet hyperplasia with hyperinsulinemia, and cold intolerance. This phenotype, however, resolves over 10-30 days due to a proliferation of preadipocytes and rapid regeneration of both brown and white adipocytes as identified by mTmG lineage tracing. This cycle can be repeated with a second round of receptor inactivation. Leptin administration prior to tamoxifen treatment blocks development of the metabolic syndrome without affecting adipocyte loss or regeneration. Thus, IR is critical in adipocyte maintenance, and this loss of adipose tissue stimulates regeneration of brown/white fat and reversal of metabolic syndrome associated with fat loss. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Loss of the tumour suppressor gene AIP mediates the browning of human brown fat tumours.

    Science.gov (United States)

    Magnusson, Linda; Hansen, Nils; Saba, Karim H; Nilsson, Jenny; Fioretos, Thoas; Rissler, Pehr; Nord, Karolin H

    2017-10-01

    Human brown fat tumours (hibernomas) show concomitant loss of the tumour suppressor genes MEN1 and AIP. We hypothesized that the brown fat phenotype is attributable to these mutations. Accordingly, in this study, we demonstrate that silencing of AIP in human brown preadipocytic and white fat cell lines results in the induction of the brown fat marker UCP1. In human adipocytic tumours, loss of MEN1 was found both in white (one of 51 lipomas) and in brown fat tumours. In contrast, concurrent loss of AIP was always accompanied by a brown fat morphology. We conclude that this white-to-brown phenotype switch in brown fat tumours is mediated by the loss of AIP. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  14. Effects of Epigallocatechin-3-Gallate on Autophagic Lipolysis in Adipocytes

    Directory of Open Access Journals (Sweden)

    Sang-Nam Kim

    2017-06-01

    Full Text Available Previous studies demonstrated effects of green tea on weight loss; however, green tea-induced modulation of adipocyte function is not fully understood. Here, we investigated effects of the major green tea phytochemical, epigallocatechin-3-gallate (EGCG on triglyceride contents, lipolysis, mitochondrial function, and autophagy, in adipocytes differentiated from C3H10T1/2 cells and immortalized pre-adipocytes in vitro. EGCG reduced the triglycerol content significantly in adipocytes by 25%, comparable to the nutrient starvation state. EGCG did not affect protein kinase A signaling or brown adipocyte marker expression in adipocytes; however, EGCG increased autophagy, as measured by autophagy flux analysis and immunoblot analysis of LC3B, ATG7, and Beclin1. EGCG treatment reduced mitochondrial membrane potential by 56.8% and intracellular ATP levels by 49.1% compared to controls. Although mammalian target of rapamycin signaling was not upregulated by EGCG treatment, EGCG treatment induced AMP-activated protein kinase phosphorylation, indicating an energy-depleted state. In addition, EGCG increased the association between RAB7 and lipid droplets, suggesting that lipophagy was activated. Finally, knockdown of Rab7 attenuated the EGCG-dependent reduction in lipid contents. Collectively, these results indicated that EGCG upregulated autophagic lipolysis in adipocytes, supporting the therapeutic potential of EGCG as a caloric restriction mimetic to prevent obesity and obesity-related metabolic diseases.

  15. Fish oil intake induces UCP1 upregulation in brown and white adipose tissue via the sympathetic nervous system.

    Science.gov (United States)

    Kim, Minji; Goto, Tsuyoshi; Yu, Rina; Uchida, Kunitoshi; Tominaga, Makoto; Kano, Yuriko; Takahashi, Nobuyuki; Kawada, Teruo

    2015-12-17

    Brown adipose tissue (BAT) plays a central role in regulating energy homeostasis, and may provide novel strategies for the treatment of human obesity. BAT-mediated thermogenesis is regulated by mitochondrial uncoupling protein 1 (UCP1) in classical brown and ectopic beige adipocytes, and is controlled by sympathetic nervous system (SNS). Previous work indicated that fish oil intake reduces fat accumulation and induces UCP1 expression in BAT; however, the detailed mechanism of this effect remains unclear. In this study, we investigated the effect of fish oil on energy expenditure and the SNS. Fish oil intake increased oxygen consumption and rectal temperature, with concomitant upregulation of UCP1 and the β3 adrenergic receptor (β3AR), two markers of beige adipocytes, in the interscapular BAT and inguinal white adipose tissue (WAT). Additionally, fish oil intake increased the elimination of urinary catecholamines and the noradrenaline (NA) turnover rate in interscapular BAT and inguinal WAT. Furthermore, the effects of fish oil on SNS-mediated energy expenditure were abolished in transient receptor potential vanilloid 1 (TRPV1) knockout mice. In conclusion, fish oil intake can induce UCP1 expression in classical brown and beige adipocytes via the SNS, thereby attenuating fat accumulation and ameliorating lipid metabolism.

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  1. File list: InP.Adp.10.AllAg.Brown_preadipocytes [Chip-atlas[Archive

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  2. Big brown bats (Eptesicus fuscus) reveal diverse strategies for sonar target tracking in clutter.

    Science.gov (United States)

    Mao, Beatrice; Aytekin, Murat; Wilkinson, Gerald S; Moss, Cynthia F

    2016-09-01

    Bats actively adjust the acoustic features of their sonar calls to control echo information specific to a given task and environment. A previous study investigated how bats adapted their echolocation behavior when tracking a moving target in the presence of a stationary distracter at different distances and angular offsets. The use of only one distracter, however, left open the possibility that a bat could reduce the interference of the distracter by turning its head. Here, bats tracked a moving target in the presence of one or two symmetrically placed distracters to investigate adaptive echolocation behavior in a situation where vocalizing off-axis would result in increased interference from distracter echoes. Both bats reduced bandwidth and duration but increased sweep rate in more challenging distracter conditions, and surprisingly, made more head turns in the two-distracter condition compared to one, but only when distracters were placed at large angular offsets. However, for most variables examined, subjects showed distinct strategies to reduce clutter interference, either by (1) changing spectral or temporal features of their calls, or (2) producing large numbers of sonar sound groups and consistent head-turning behavior. The results suggest that individual bats can use different strategies for target tracking in cluttered environments.

  3. Lkb1 controls brown adipose tissue growth and thermogenesis by regulating the intracellular localization of CRTC3

    Science.gov (United States)

    Shan, Tizhong; Xiong, Yan; Zhang, Pengpeng; Li, Zhiguo; Jiang, Qingyang; Bi, Pengpeng; Yue, Feng; Yang, Gongshe; Wang, Yizhen; Liu, Xiaoqi; Kuang, Shihuan

    2016-01-01

    Brown adipose tissue (BAT) dissipates energy through Ucp1-mediated uncoupled respiration and its activation may represent a therapeutic strategy to combat obesity. Here we show that Lkb1 controls BAT expansion and UCP1 expression in mice. We generate adipocyte-specific Lkb1 knockout mice and show that, compared with wild-type littermates, these mice exhibit elevated UCP1 expression in BAT and subcutaneous white adipose tissue, have increased BAT mass and higher energy expenditure. Consequently, KO mice have improved glucose tolerance and insulin sensitivity, and are more resistant to high-fat diet (HFD)-induced obesity. Deletion of Lkb1 results in a cytoplasm to nuclear translocation of CRTC3 in brown adipocytes, where it recruits C/EBPβ to enhance Ucp1 transcription. In parallel, the absence of Lkb1 also suppresses AMPK activity, leading to activation of the mTOR signalling pathway and subsequent BAT expansion. These data suggest that inhibition of Lkb1 or its downstream signalling in adipocytes could be a novel strategy to increase energy expenditure in the context of obesity, diabetes and other metabolic diseases. PMID:27461402

  4. Browning attenuates murine white adipose tissue expansion during postnatal development.

    Science.gov (United States)

    Lasar, D; Julius, A; Fromme, T; Klingenspor, M

    2013-05-01

    During postnatal development of mice distinct white adipose tissue depots display a transient appearance of brown-like adipocytes. These brite (brown in white) adipocytes share characteristics with classical brown adipocytes including a multilocular appearance and the expression of the thermogenic protein uncoupling protein 1. In this study, we compared two inbred mouse strains 129S6sv/ev and C57BL6/N known for their different propensity to diet-induced obesity. We observed transient browning in retroperitoneal and inguinal adipose tissue depots of these two strains. From postnatal day 10 to 20 the increase in the abundance of multilocular adipocytes and uncoupling protein 1 expression was higher in 129S6sv/ev than in C57BL6/N pups. The parallel increase in the mass of the two fat depots was attenuated during this browning period. Conversely, epididymal white and interscapular brown adipose tissue displayed a steady increase in mass during the first 30 days of life. In this period, 129S6sv/ev mice developed a significantly higher total body fat mass than C57BL6/N. Thus, while on a local depot level a high number of brite cells is associated with the attenuation of adipose tissue expansion the strain comparison reveals no support for a systemic impact on energy balance. This article is part of a Special Issue entitled Brown and White Fat: From Signaling to Disease.

  5. Two types of brown adipose tissue in humans.

    Science.gov (United States)

    Lidell, Martin E; Betz, Matthias J; Enerbäck, Sven

    2014-01-01

    During the last years the existence of metabolically active brown adipose tissue in adult humans has been widely accepted by the research community. Its unique ability to dissipate chemical energy stored in triglycerides as heat makes it an attractive target for new drugs against obesity and its related diseases. Hence the tissue is now subject to intense research, the hypothesis being that an expansion and/or activation of the tissue is associated with a healthy metabolic phenotype. Animal studies provide evidence for the existence of at least two types of brown adipocytes. Apart from the classical brown adipocyte that is found primarily in the interscapular region where it constitutes a thermogenic organ, a second type of brown adipocyte, the so-called beige adipocyte, can appear within white adipose tissue depots. The fact that the two cell types develop from different precursors suggests that they might be recruited and stimulated by different cues and therefore represent two distinct targets for therapeutic intervention. The aim of this commentary is to discuss recent work addressing the question whether also humans possess two types of brown adipocytes and to highlight some issues when looking for molecular markers for such cells.

  6. Enhanced Differentiation of Three-Gene-Reprogrammed Induced Pluripotent Stem Cells into Adipocytes via Adenoviral-Mediated PGC-1α Overexpression

    Directory of Open Access Journals (Sweden)

    Yi-Jen Chen

    2011-11-01

    Full Text Available Induced pluripotent stem cells formed by the introduction of only three factors, Oct4/Sox2/Klf4 (3-gene iPSCs, may provide a safer option for stem cell-based therapy than iPSCs conventionally introduced with four-gene iPSCs. Peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α plays an important role during brown fat development. However, the potential roles of PGC-1α in regulating mitochondrial biogenesis and the differentiation of iPSCs are still unclear. Here, we investigated the effects of adenovirus-mediated PGC-1α overexpression in 3-gene iPSCs. PGC-1α overexpression resulted in increased mitochondrial mass, reactive oxygen species production, and oxygen consumption. Microarray-based bioinformatics showed that the gene expression pattern of PGC-1α-overexpressing 3-gene iPSCs resembled the expression pattern observed in adipocytes. Furthermore, PGC-1α overexpression enhanced adipogenic differentiation and the expression of several brown fat markers, including uncoupling protein-1, cytochrome C, and nuclear respiratory factor-1, whereas it inhibited the expression of the white fat marker uncoupling protein-2. Furthermore, PGC-1α overexpression significantly suppressed osteogenic differentiation. These data demonstrate that PGC-1α directs the differentiation of 3-gene iPSCs into adipocyte-like cells with features of brown fat cells. This may provide a therapeutic strategy for the treatment of mitochondrial disorders and obesity.

  7. Mir193b-365 is essential for brown fat differentiation.

    Science.gov (United States)

    Sun, Lei; Xie, Huangming; Mori, Marcelo A; Alexander, Ryan; Yuan, Bingbing; Hattangadi, Shilpa M; Liu, Qingqing; Kahn, C Ronald; Lodish, Harvey F

    2011-07-10

    Mammals have two principal types of fat. White adipose tissue primarily serves to store extra energy as triglycerides, whereas brown adipose tissue is specialized to burn lipids for heat generation and energy expenditure as a defence against cold and obesity. Recent studies have demonstrated that brown adipocytes arise in vivo from a Myf5-positive, myoblastic progenitor by the action of Prdm16 (PR domain containing 16). Here, we identified a brown-fat-enriched miRNA cluster, MiR-193b-365, as a key regulator of brown fat development. Blocking miR-193b and/or miR-365 in primary brown preadipocytes markedly impaired brown adipocyte adipogenesis by enhancing Runx1t1 (runt-related transcription factor 1; translocated to, 1) expression, whereas myogenic markers were significantly induced. Forced expression of Mir193b and/or Mir365 in C2C12 myoblasts blocked the entire programme of myogenesis, and, in adipogenic conditions, miR-193b induced myoblasts to differentiate into brown adipocytes. Mir193b-365 was upregulated by Prdm16 partially through Pparα. Our results demonstrate that Mir193b-365 serves as an essential regulator for brown fat differentiation, in part by repressing myogenesis.

  8. Adipocyte-specific Hypoxia-inducible gene 2 promotes fat deposition and diet-induced insulin resistance.

    Science.gov (United States)

    DiStefano, Marina T; Roth Flach, Rachel J; Senol-Cosar, Ozlem; Danai, Laura V; Virbasius, Joseph V; Nicoloro, Sarah M; Straubhaar, Juerg; Dagdeviren, Sezin; Wabitsch, Martin; Gupta, Olga T; Kim, Jason K; Czech, Michael P

    2016-12-01

    Adipose tissue relies on lipid droplet (LD) proteins in its role as a lipid-storing endocrine organ that controls whole body metabolism. Hypoxia-inducible Gene 2 (Hig2) is a recently identified LD-associated protein in hepatocytes that promotes hepatic lipid storage, but its role in the adipocyte had not been investigated. Here we tested the hypothesis that Hig2 localization to LDs in adipocytes promotes adipose tissue lipid deposition and systemic glucose homeostasis. White and brown adipocyte-deficient (Hig2(fl/fl) × Adiponection cre+) and selective brown/beige adipocyte-deficient (Hig2(fl/fl) × Ucp1 cre+) mice were generated to investigate the role of Hig2 in adipose depots. Additionally, we used multiple housing temperatures to investigate the role of active brown/beige adipocytes in this process. Hig2 localized to LDs in SGBS cells, a human adipocyte cell strain. Mice with adipocyte-specific Hig2 deficiency in all adipose depots demonstrated reduced visceral adipose tissue weight and increased glucose tolerance. This metabolic effect could be attributed to brown/beige adipocyte-specific Hig2 deficiency since Hig2(fl/fl) × Ucp1 cre+ mice displayed the same phenotype. Furthermore, when adipocyte-deficient Hig2 mice were moved to thermoneutral conditions in which non-shivering thermogenesis is deactivated, these improvements were abrogated and glucose intolerance ensued. Adipocyte-specific Hig2 deficient animals displayed no detectable changes in adipocyte lipolysis or energy expenditure, suggesting that Hig2 may not mediate these metabolic effects by restraining lipolysis in adipocytes. We conclude that Hig2 localizes to LDs in adipocytes, promoting adipose tissue lipid deposition and that its selective deficiency in active brown/beige adipose tissue mediates improved glucose tolerance at 23 °C. Reversal of this phenotype at thermoneutrality in the absence of detectable changes in energy expenditure, adipose mass, or liver triglyceride suggests that

  9. In vivo adeno-associated viral vector-mediated genetic engineering of white and brown adipose tissue in adult mice.

    Science.gov (United States)

    Jimenez, Veronica; Muñoz, Sergio; Casana, Estefania; Mallol, Cristina; Elias, Ivet; Jambrina, Claudia; Ribera, Albert; Ferre, Tura; Franckhauser, Sylvie; Bosch, Fatima

    2013-12-01

    Adipose tissue is pivotal in the regulation of energy homeostasis through the balance of energy storage and expenditure and as an endocrine organ. An inadequate mass and/or alterations in the metabolic and endocrine functions of adipose tissue underlie the development of obesity, insulin resistance, and type 2 diabetes. To fully understand the metabolic and molecular mechanism(s) involved in adipose dysfunction, in vivo genetic modification of adipocytes holds great potential. Here, we demonstrate that adeno-associated viral (AAV) vectors, especially serotypes 8 and 9, mediated efficient transduction of white (WAT) and brown adipose tissue (BAT) in adult lean and obese diabetic mice. The use of short versions of the adipocyte protein 2 or uncoupling protein-1 promoters or micro-RNA target sequences enabled highly specific, long-term AAV-mediated transgene expression in white or brown adipocytes. As proof of concept, delivery of AAV vectors encoding for hexokinase or vascular endothelial growth factor to WAT or BAT resulted in increased glucose uptake or increased vessel density in targeted depots. This method of gene transfer also enabled the secretion of stable high levels of the alkaline phosphatase marker protein into the bloodstream by transduced WAT. Therefore, AAV-mediated genetic engineering of adipose tissue represents a useful tool for the study of adipose pathophysiology and, likely, for the future development of new therapeutic strategies for obesity and diabetes.

  10. In Vivo Adeno-Associated Viral Vector–Mediated Genetic Engineering of White and Brown Adipose Tissue in Adult Mice

    Science.gov (United States)

    Jimenez, Veronica; Muñoz, Sergio; Casana, Estefania; Mallol, Cristina; Elias, Ivet; Jambrina, Claudia; Ribera, Albert; Ferre, Tura; Franckhauser, Sylvie; Bosch, Fatima

    2013-01-01

    Adipose tissue is pivotal in the regulation of energy homeostasis through the balance of energy storage and expenditure and as an endocrine organ. An inadequate mass and/or alterations in the metabolic and endocrine functions of adipose tissue underlie the development of obesity, insulin resistance, and type 2 diabetes. To fully understand the metabolic and molecular mechanism(s) involved in adipose dysfunction, in vivo genetic modification of adipocytes holds great potential. Here, we demonstrate that adeno-associated viral (AAV) vectors, especially serotypes 8 and 9, mediated efficient transduction of white (WAT) and brown adipose tissue (BAT) in adult lean and obese diabetic mice. The use of short versions of the adipocyte protein 2 or uncoupling protein-1 promoters or micro-RNA target sequences enabled highly specific, long-term AAV-mediated transgene expression in white or brown adipocytes. As proof of concept, delivery of AAV vectors encoding for hexokinase or vascular endothelial growth factor to WAT or BAT resulted in increased glucose uptake or increased vessel density in targeted depots. This method of gene transfer also enabled the secretion of stable high levels of the alkaline phosphatase marker protein into the bloodstream by transduced WAT. Therefore, AAV-mediated genetic engineering of adipose tissue represents a useful tool for the study of adipose pathophysiology and, likely, for the future development of new therapeutic strategies for obesity and diabetes. PMID:24043756

  11. Adipocyte-specific deletion of Ip6k1 reduces diet-induced obesity by enhancing AMPK-mediated thermogenesis

    Science.gov (United States)

    Zhu, Qingzhang; Ghoshal, Sarbani; Rodrigues, Ana; Gao, Su; Asterian, Alice; Kamenecka, Theodore M.; Barrow, James C.

    2016-01-01

    Enhancing energy expenditure (EE) is an attractive strategy to combat obesity and diabetes. Global deletion of Ip6k1 protects mice from diet-induced obesity (DIO) and insulin resistance, but the tissue-specific mechanism by which IP6K1 regulates body weight is unknown. Here, we have demonstrated that IP6K1 regulates fat accumulation by modulating AMPK-mediated adipocyte energy metabolism. Cold exposure led to downregulation of Ip6k1 in murine inguinal and retroperitoneal white adipose tissue (IWAT and RWAT) depots. Adipocyte-specific deletion of Ip6k1 (AdKO) enhanced thermogenic EE, which protected mice from high-fat diet–induced weight gain at ambient temperature (23°C), but not at thermoneutral temperature (30°C). AdKO-induced increases in thermogenesis also protected mice from cold-induced decreases in body temperature. UCP1, PGC1α, and other markers of browning and thermogenesis were elevated in IWAT and RWAT of AdKO mice. Cold-induced activation of sympathetic signaling was unaltered, whereas AMPK was enhanced, in AdKO IWAT. Moreover, beige adipocytes from AdKO IWAT displayed enhanced browning, which was diminished by AMPK depletion. Furthermore, we determined that IP6 and IP6K1 differentially regulate upstream kinase-mediated AMPK stimulatory phosphorylation in vitro. Finally, treating mildly obese mice with the IP6K inhibitor TNP enhanced thermogenesis and inhibited progression of DIO. Thus, IP6K1 regulates energy metabolism via a mechanism that could potentially be targeted in obesity. PMID:27701146

  12. Silibinin regulates lipid metabolism and differentiation in functional human adipocytes

    Directory of Open Access Journals (Sweden)

    Ignazio eBarbagallo

    2016-01-01

    Full Text Available Silibinin, a natural plant flavonoid, is the main active constituent found in milk thistle (Silybum marianum. It is known to have hepatoprotective, anti-neoplastic effect and suppresses lipid accumulation in adipocytes. Objective of this study was to investigate the effect of silibinin on adipogenic differentiation and thermogenic capacity of human adipose tissue derived mesenchymal stem cells. Silibinin (10 μM treatment, either at the beginning or at the end of adipogenic differentiation, resulted in an increase of SIRT-1, PPARα, Pgc-1α and UCPs gene expression. Moreover, silibinin administration resulted in a decrease of PPARγ, FABP4, FAS and MEST/PEG1 gene expression during the differentiation, confirming that this compound is able to reduce fatty acid accumulation and adipocyte size. Our data showed that silibinin regulated adipocyte lipid metabolism, inducing thermogenesis and promoting a brown remodelling in adipocyte. Taken together, our findings suggest that silibinin increases UCPs expression by stimulation of SIRT1, PPARα and Pgc-1α, improved metabolic parameters, decreased lipid mass leading to the formation of functional adipocytes.

  13. The fat controller: adipocyte development.

    Directory of Open Access Journals (Sweden)

    Jacqueline M Stephens

    Full Text Available Obesity is a condition characterized by excess adipose tissue that results from positive energy balance and is the most common metabolic disorder in the industrialized world. The obesity epidemic shows no sign of slowing, and it is increasingly a global problem. Serious clinical problems associated with obesity include an increased risk for type 2 diabetes, atherosclerosis, and cancer. Hence, understanding the origin and development of adipocytes and adipose tissue will be critical to the analysis and treatment of metabolic diseases. Historically, albeit incorrectly, adipocytes were thought to be inert cells whose singular function was lipid storage. It is now known that adipocytes have other critical functions; the most important include sensitivity to insulin and the ability to produce and secrete adipocyte-specific endocrine hormones that regulate energy homeostasis in other tissues. Today, adipocytes are recognized as critical regulators of whole-body metabolism and known to be involved in the pathogenesis of a variety of metabolic diseases. All cells come from other cells and many cells arise from precursor cells. Adipocytes are not created from other adipocytes, but they arise from precursor cells. In the last two decades, scientists have discovered the function of many proteins that influence the ability of precursor cells to become adipocytes. If the expansion of the adipose tissue is the problem, it seems logical that adipocyte development inhibitors could be a viable anti-obesity therapeutic. However, factors that block adipocyte development and limit adipocyte expansion also impair metabolic health. This notion may be counterintuitive, but several lines of evidence support the idea that blocking adipocyte development is unhealthy. For this reason it is clear that we need a better understanding of adipocyte development.

  14. Leptin and insulin act on POMC neurons to promote the browning of white fat

    Science.gov (United States)

    Dodd, Garron; Descherf, Stephanie; Loh, Kim; Simonds, Stephanie E.; Wiede, Florian; Balland, Eglantine; Merry, Troy L.; Münzberg, Heike; Zhang, Zhong-Yin; Kahn, Barbara B.; Neel, Benjamin G.; Bence, Kendra K.; Andrews, Zane B.; Cowley, Michael A.; Tiganis, Tony

    2015-01-01

    SUMMARY The primary task of white adipose tissue (WAT) is the storage of lipids. However, ‘beige’ adipocytes also exist in WAT. Beige adipocytes burn fat and dissipate the energy as heat, but their abundance is diminished in obesity. Stimulating beige adipocyte development, or WAT browning, increases energy expenditure and holds potential for combating metabolic disease and obesity. Here we report that insulin and leptin act together on hypothalamic neurons to promote WAT browning and weight loss. Deletion of the phosphatases PTP1B and TCPTP enhanced insulin and leptin signaling in proopiomelanocortin neurons and prevented diet-induced obesity by increasing WAT browning and energy expenditure. The co-infusion of insulin plus leptin into the CNS or the activation of proopiomelanocortin neurons also increased WAT browning and decreased adiposity. Our findings identify a homeostatic mechanism for coordinating the status of energy stores, as relayed by insulin and leptin, with the central control of WAT browning. PMID:25594176

  15. BMP4-mediated brown fat-like changes in white adipose tissue alter glucose and energy homeostasis.

    Science.gov (United States)

    Qian, Shu-Wen; Tang, Yan; Li, Xi; Liu, Yuan; Zhang, You-You; Huang, Hai-Yan; Xue, Rui-Dan; Yu, Hao-Yong; Guo, Liang; Gao, Hui-Di; Liu, Yan; Sun, Xia; Li, Yi-Ming; Jia, Wei-Ping; Tang, Qi-Qun

    2013-02-26

    Expression of bone morphogenetic protein 4 (BMP4) in adipocytes of white adipose tissue (WAT) produces "white adipocytes" with characteristics of brown fat and leads to a reduction of adiposity and its metabolic complications. Although BMP4 is known to induce commitment of pluripotent stem cells to the adipocyte lineage by producing cells that possess the characteristics of preadipocytes, its effects on the mature white adipocyte phenotype and function were unknown. Forced expression of a BMP4 transgene in white adipocytes of mice gives rise to reduced WAT mass and white adipocyte size along with an increased number of a white adipocyte cell types with brown adipocyte characteristics comparable to those of beige or brite adipocytes. These changes correlate closely with increased energy expenditure, improved insulin sensitivity, and protection against diet-induced obesity and diabetes. Conversely, BMP4-deficient mice exhibit enlarged white adipocyte morphology and impaired insulin sensitivity. We identify peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC1α) as the target of BMP signaling required for these brown fat-like changes in WAT. This effect of BMP4 on WAT appears to extend to human adipose tissue, because the level of expression of BMP4 in WAT correlates inversely with body mass index. These findings provide a genetic and metabolic basis for BMP4's role in altering insulin sensitivity by affecting WAT development.

  16. Selection of Aptamers for Mature White Adipocytes by Cell SELEX Using Flow Cytometry

    Science.gov (United States)

    Kim, Eun Young; Kim, Ji Won; Kim, Won Kon; Han, Baek Soo; Park, Sung Goo; Chung, Bong Hyun; Lee, Sang Chul; Bae, Kwang-Hee

    2014-01-01

    Background Adipose tissue, mainly composed of adipocytes, plays an important role in metabolism by regulating energy homeostasis. Obesity is primarily caused by an abundance of adipose tissue. Therefore, specific targeting of adipose tissue is critical during the treatment of obesity, and plays a major role in overcoming it. However, the knowledge of cell-surface markers specific to adipocytes is limited. Methods and Results We applied the CELL SELEX (Systematic Evolution of Ligands by EXponential enrichment) method using flow cytometry to isolate molecular probes for specific recognition of adipocytes. The aptamer library, a mixture of FITC-tagged single-stranded random DNAs, is used as a source for acquiring molecular probes. With the increasing number of selection cycles, there was a steady increase in the fluorescence intensity toward mature adipocytes. Through 12 rounds of SELEX, enriched aptamers showing specific recognition toward mature 3T3-L1 adipocyte cells were isolated. Among these, two aptamers (MA-33 and 91) were able to selectively bind to mature adipocytes with an equilibrium dissociation constant (Kd) in the nanomolar range. These aptamers did not bind to preadipocytes or other cell lines (such as HeLa, HEK-293, or C2C12 cells). Additionally, it was confirmed that MA-33 and 91 can distinguish between mature primary white and primary brown adipocytes. Conclusions These selected aptamers have the potential to be applied as markers for detecting mature white adipocytes and monitoring adipogenesis, and could emerge as an important tool in the treatment of obesity. PMID:24844710

  17. Vascular endothelial growth factor is important for brown adipose tissue development and maintenance.

    Science.gov (United States)

    Bagchi, Mandrita; Kim, Leo A; Boucher, Jeremie; Walshe, Tony E; Kahn, C Ronald; D'Amore, Patricia A

    2013-08-01

    Vascular endothelial growth factor (VEGF) is critical for angiogenesis, but also has pleiotropic effects on several nonvascular cells. Our aim was to investigate the role of VEGF in brown adipose tissue (BAT). We show that VEGF expression increases 2.5-fold during differentiation of cultured murine brown adipocytes and that VEGF receptor-2 is phosphorylated, indicating VEGF signaling. VEGF increased proliferation in brown preadipocytes in vitro by 70%, and blockade of VEGF signaling using anti-VEGFR2 antibody DC101 increased brown adipocyte apoptosis, as determined by cell number and activation of caspase 3. Systemic VEGF neutralization in mice, accomplished by adenoviral expression of soluble Flt1, resulted in 7-fold increase in brown adipocyte apoptosis, mitochondrial degeneration, and increased mitophagy compared to control mice expressing a null adenovirus. Absence of the heparan sulfate-binding VEGF isoforms, VEGF164 and VEGF188, resulted in abnormal BAT development in mice at E15.5, with fewer brown adipocytes and lower mitochondrial protein compared to wild-type littermates. These results suggest a role for VEGF in brown adipocytes and preadipocytes to promote survival, proliferation, and normal mitochondria and development.

  18. Dynamic regulation of genes involved in mitochondrial DNA replication and transcription during mouse brown fat cell differentiation and recruitment

    DEFF Research Database (Denmark)

    Murholm, Maria; Dixen, Karen; Qvortrup, Klaus

    2009-01-01

    BACKGROUND: Brown adipocytes are specialised in dissipating energy through adaptive thermogenesis, whereas white adipocytes are specialised in energy storage. These essentially opposite functions are possible for two reasons relating to mitochondria, namely expression of uncoupling protein 1 (UCP1......) and a remarkably higher mitochondrial abundance in brown adipocytes. METHODOLOGY/PRINCIPAL FINDINGS: Here we report a comprehensive characterisation of gene expression linked to mitochondrial DNA replication, transcription and function during white and brown fat cell differentiation in vitro as well as in white...... precursor cells promotes mitochondrial DNA replication, and that silencing of PRDM16 expression during brown fat cell differentiation blunts mitochondrial biogenesis and expression of brown fat cell markers. CONCLUSIONS/SIGNIFICANCE: Using both in vitro and in vivo model systems of white and brown fat cell...

  19. NFIA co-localizes with PPARγ and transcriptionally controls the brown fat gene program

    DEFF Research Database (Denmark)

    Hiraike, Yuta; Waki, Hironori; Yu, Jing

    2017-01-01

    . NFIA and the master transcriptional regulator of adipogenesis, PPARγ, co-localize at the brown-fat-specific enhancers. Moreover, the binding of NFIA precedes and facilitates the binding of PPARγ, leading to increased chromatin accessibility and active transcription. Introduction of NFIA into myoblasts...... results in brown adipocyte differentiation. Conversely, the brown fat of NFIA-knockout mice displays impaired expression of the brown-fat-specific genes and reciprocal elevation of muscle genes. Finally, expression of NFIA and the brown-fat-specific genes is positively correlated in human brown fat......Brown fat dissipates energy as heat and protects against obesity. Here, we identified nuclear factor I-A (NFIA) as a transcriptional regulator of brown fat by a genome-wide open chromatin analysis of murine brown and white fat followed by motif analysis of brown-fat-specific open chromatin regions...

  20. Effects of ethyl acetate extract of Kaempferia parviflora on brown adipose tissue.

    Science.gov (United States)

    Kobayashi, Hiroko; Horiguchi-Babamoto, Emi; Suzuki, Mio; Makihara, Hiroko; Tomozawa, Hiroshi; Tsubata, Masahito; Shimada, Tsutomu; Sugiyama, Kiyoshi; Aburada, Masaki

    2016-01-01

    We have previously reported the effects of Kaempferia parviflora (KP), including anti-obesity, preventing various metabolic diseases, and regulating differentiation of white adipose cells. In this study we used Tsumura, Suzuki, Obese Diabetes (TSOD) mice--an animal model of spontaneous obese type II diabetes--and primary brown preadipocytes to examine the effects of the ethyl acetate extract of KP (KPE) on brown adipose tissue, which is one of the energy expenditure organs. TSOD mice were fed with MF mixed with either KPE 0.3 or 1% for 8 weeks. Computed tomography images showed that whitening of brown adipocytes was suppressed in the interscapular tissue of the KPE group. We also examined mRNA expression of uncoupling protein 1 (UCP-1) and β3-adrenalin receptor (β3AR) in brown adipose tissue. As a result, mRNA expression of UCP-1 significantly increased in the KPE 1% treatment group, indicating that KPE activated brown adipose tissue. We then evaluated the direct effects of KPE on brown adipocytes using primary brown preadipocytes isolated from interscapular brown adipocytes in ICR mice. Triacylglycerol (TG) accumulation in primary brown preadipocytes was increased by KPE in a dose-dependent manner. Each mRNA expression of peroxisome proliferator-activated receptor γ (PPARγ), UCP-1, and β3AR exhibited an upward trend compared with the control group. Moreover, some polymethoxyflavonoids (PMFs), the main compound in KP, also increased TG accumulation. This study therefore showed that KPE enhanced the thermogenesis effect of brown adipocytes as well as promoted the differentiation of brown adipocyte cells.

  1. Turning up the heat : role of brown adipose tissue in metabolic disease

    NARCIS (Netherlands)

    Boon, Mariëtte Rebecca

    2014-01-01

    In 1551, the Swiss naturalist Konrad Gessner first described brown adipose tissue (BAT) as being “neither fat, nor flesh (nec pinguitudo, nec caro), but something in between”. Now, some 460 years later, we know that Gessner had guessed the origin of brown adipocytes correctly. A unique property of t

  2. Evaluation of markers of beige adipocytes in white adipose tissue of the mouse

    Science.gov (United States)

    Background: There is a growing interest in exploiting the induction of beige or “brite” (brown in white) adipocytes (beigeing) to combat obesity and its comorbidities. However, there is some uncertainty regarding the best markers to evaluate the occurrence or magnitude of beigeing in white adipose t...

  3. A classical brown adipose tissue mRNA signature partly overlaps with brite in the supraclavicular region of adult humans

    DEFF Research Database (Denmark)

    Jespersen, Naja Zenius; Larsen, Therese Juhlin; Peijs, Lone

    2013-01-01

    . A similar mRNA expression profile was observed when comparing isolated human adipocytes from BAT and white adipose tissue (WAT) depots, differentiated in vitro. In conclusion, our data suggest that human BAT might consist of both classical brown and recruitable brite adipocytes, an observation important...

  4. Mechanism of Regulation of Adipocyte Numbers in Adult Organisms Through Differentiation and Apoptosis Homeostasis.

    Science.gov (United States)

    Bozec, Aline; Hannemann, Nicole

    2016-06-03

    Considering that adipose tissue (AT) is an endocrine organ, it can influence whole body metabolism. Excessive energy storage leads to the dysregulation of adipocytes, which in turn induces abnormal secretion of adipokines, triggering metabolic syndromes such as obesity, dyslipidemia, hyperglycemia, hyperinsulinemia, insulin resistance and type 2 diabetes. Therefore, investigating the molecular mechanisms behind adipocyte dysregulation could help to develop novel therapeutic strategies. Our protocol describes methods for evaluating the molecular mechanism affected by hypoxic conditions of the AT, which correlates with adipocyte apoptosis in adult mice. This protocol describes how to analyze AT in vivo through gene expression profiling as well as histological analysis of adipocyte differentiation, proliferation and apoptosis during hypoxia exposure, ascertained through staining of hypoxic cells or HIF-1α protein. Furthermore, in vitro analysis of adipocyte differentiation and its responses to various stimuli completes the characterization of the molecular pathways behind possible adipocyte dysfunction leading to metabolic syndromes.

  5. Role of adipocyte-derived lipoprotein lipase in adipocyte hypertrophy

    Directory of Open Access Journals (Sweden)

    Orlando Robert A

    2007-10-01

    Full Text Available Abstract Background A major portion of available fatty acids for adipocyte uptake is derived from lipoprotein lipase (LPL-mediated hydrolysis of circulating lipoprotein particles. In vivo studies aimed at identifying the precise role of adipocyte-derived LPL in fat storage function of adipose tissue have been unable to provide conclusive evidence due to compensatory mechanisms that activate endogenous fatty acid synthesis. To address this gap in knowledge, we have measured the effect of reducing adipocyte LPL expression on intracellular lipid accumulation using a well-established cultured model of adipocyte differentiation. Methods siRNA specific for mouse LPL was transfected into 3T3-L1 adipocytes. Expression of LPL was measured by quantitative real-time PCR and cell surface-associated LPL enzymatic activity was measured by colorimetric detection following substrate (p-nitrophenyl butyrate hydrolysis. Apolipoprotein CII and CIII expression ratios were also measured by qRT-PCR. Intracellular lipid accumulation was quantified by Nile Red staining. Results During differentiation of 3T3-L1 pre-adipocytes, LPL mRNA expression increases 6-fold resulting in a 2-fold increase in cell surface-associated LPL enzymatic activity. Parallel to this increase in LPL expression, we found that intracellular lipids increased ~10-fold demonstrating a direct correlation between adipocyte-derived LPL expression and lipid storage. We next reduced LPL expression in adipocytes using siRNA transfections to directly quantify the contributions of adipocyte-derived LPL to lipid storage, This treatment reduced LPL mRNA expression and cell surface-associated LPL enzymatic activity to ~50% of non-treated controls while intracellular lipid levels were reduced by 80%. Exogenous addition of purified LPL (to restore extracellular lipolytic activity or palmitate (as a source of free fatty acids to siRNA-treated cells restored intracellular lipid levels to those measured for non

  6. Mechanism of Regulation of Adipocyte Numbers in Adult Organisms Through Differentiation and Apoptosis Homeostasis

    OpenAIRE

    Bozec, Aline; Hannemann, Nicole

    2016-01-01

    Considering that adipose tissue (AT) is an endocrine organ, it can influence whole body metabolism. Excessive energy storage leads to the dysregulation of adipocytes, which in turn induces abnormal secretion of adipokines, triggering metabolic syndromes such as obesity, dyslipidemia, hyperglycemia, hyperinsulinemia, insulin resistance and type 2 diabetes. Therefore, investigating the molecular mechanisms behind adipocyte dysregulation could help to develop novel therapeutic strategies. Our pr...

  7. Increasing cAMP levels of preadipocytes by cyanidin-3-glucoside treatment induces the formation of beige phenotypes in 3T3-L1 adipocytes.

    Science.gov (United States)

    Matsukawa, Toshiya; Villareal, Myra O; Motojima, Hideko; Isoda, Hiroko

    2017-02-01

    Obesity is a serious health problem and a major risk factor for the onset of several diseases such as heart disease, diabetes, stroke and cancer. The conversion of white adipocytes to brown-like adipocytes, also called beige or brite adipocytes, by pharmacological and dietary compounds has gained attention as an effective treatment for obesity. Cyanidin-3-glucoside (Cy3G), a polyphenolic compound contained in black soybean, blueberry and grape, has several antiobesity effects. However, there are no reports on the role of Cy3G in the induction of differentiation of preadipocytes to beige adipocytes and corresponding phenotypes. Here, the formation of beige adipocyte phenotypes following treatment with Cy3G was evaluated using 3T3-L1 adipocytes. Cy3G induced phenotypic changes to white adipocytes, such as increased multilocular lipid droplets and mitochondrial content. Additionally, the expression of mitochondrial genes (TFAM, SOD2, UCP-1 and UCP-2), UCP-1 protein and beige adipocyte markers (CITED1 and TBX1) in 3T3-L1 adipocytes was increased by Cy3G. Furthermore, Cy3G promoted preadipocyte differentiation by up-regulating of C/EBPβ through the elevation of the intracellular cAMP levels. These results indicated that Cy3G elevates the intracellular cAMP levels, which induces beige adipocyte phenotypes. This is the first report on the effect of Cy3G on induction of differentiation of preadipocytes into beige adipocyte phenotypes. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Pmch-deficiency in rats is associated with normal adipocyte differentiation and lower sympathetic adipose drive.

    Science.gov (United States)

    Mul, Joram D; O'Duibhir, Eoghan; Shrestha, Yogendra B; Koppen, Arjen; Vargoviç, Peter; Toonen, Pim W; Zarebidaki, Eleen; Kvetnansky, Richard; Kalkhoven, Eric; Cuppen, Edwin; Bartness, Timothy J

    2013-01-01

    The orexigenic neuropeptide melanin-concentrating hormone (MCH), a product of Pmch, is an important mediator of energy homeostasis. Pmch-deficient rodents are lean and smaller, characterized by lower food intake, body-, and fat mass. Pmch is expressed in hypothalamic neurons that ultimately are components in the sympathetic nervous system (SNS) drive to white and interscapular brown adipose tissue (WAT, iBAT, respectively). MCH binds to MCH receptor 1 (MCH1R), which is present on adipocytes. Currently it is unknown if Pmch-ablation changes adipocyte differentiation or sympathetic adipose drive. Using Pmch-deficient and wild-type rats on a standard low-fat diet, we analyzed dorsal subcutaneous and perirenal WAT mass and adipocyte morphology (size and number) throughout development, and indices of sympathetic activation in WAT and iBAT during adulthood. Moreover, using an in vitro approach we investigated the ability of MCH to modulate 3T3-L1 adipocyte differentiation. Pmch-deficiency decreased dorsal subcutaneous and perirenal WAT mass by reducing adipocyte size, but not number. In line with this, in vitro 3T3-L1 adipocyte differentiation was unaffected by MCH. Finally, adult Pmch-deficient rats had lower norepinephrine turnover (an index of sympathetic adipose drive) in WAT and iBAT than wild-type rats. Collectively, our data indicate that MCH/MCH1R-pathway does not modify adipocyte differentiation, whereas Pmch-deficiency in laboratory rats lowers adiposity throughout development and sympathetic adipose drive during adulthood.

  9. Evidence for small scale variation in the vertebrate brain: mating strategy and sex affect brain size and structure in wild brown trout (Salmo trutta).

    Science.gov (United States)

    Kolm, N; Gonzalez-Voyer, A; Brelin, D; Winberg, S

    2009-12-01

    The basis for our knowledge of brain evolution in vertebrates rests heavily on empirical evidence from comparative studies at the species level. However, little is still known about the natural levels of variation and the evolutionary causes of differences in brain size and brain structure within-species, even though selection at this level is an important initial generator of macroevolutionary patterns across species. Here, we examine how early life-history decisions and sex are related to brain size and brain structure in wild populations using the existing natural variation in mating strategies among wild brown trout (Salmo trutta). By comparing the brains of precocious fish that remain in the river and sexually mature at a small size with those of migratory fish that migrate to the sea and sexually mature at a much larger size, we show, for the first time in any vertebrate, strong differences in relative brain size and brain structure across mating strategies. Precocious fish have larger brain size (when controlling for body size) but migratory fish have a larger cerebellum, the structure in charge of motor coordination. Moreover, we demonstrate sex-specific differences in brain structure as female precocious fish have a larger brain than male precocious fish while males of both strategies have a larger telencephalon, the cognitive control centre, than females. The differences in brain size and structure across mating strategies and sexes thus suggest the possibility for fine scale adaptive evolution of the vertebrate brain in relation to different life histories.

  10. Fatty acid-induced mitochondrial uncoupling in adipocytes is not a promising target for treatment of insulin resistance unless adipocyte oxidative capacity is increased.

    Science.gov (United States)

    Frayn, K N; Langin, D; Karpe, F

    2008-03-01

    The release of fatty acids from white adipose tissue is regulated at several levels. We have examined the suggestion that fatty acid release might be diminished by upregulation of mitochondrial fatty acid oxidation in the adipocyte, through increasing mitochondrial uncoupling. The intrinsic oxidative capacity of white adipose tissue is low, and older studies suggest that there is little fatty acid oxidation in white adipocytes, human or rodent. We have examined data on fatty acid metabolism and O(2) consumption in human white adipose tissue in vivo, and conclude that increasing fatty acid oxidation within the oxidative capacity of the tissue would produce only small changes (a few percent) in fatty acid release. The major locus of control of fatty acid release beyond the stimulation of lipolysis is the pathway of fatty acid esterification, already probably targeted by the thiazolidinedione insulin-sensitising agents. An alternative approach would be to upregulate the mitochondrial capacity of the adipocyte. We review proof-of-concept studies in which the phenotype of the white adipocyte has been changed to resemble that of the brown adipocyte by expression of peroxisome proliferator-activated receptor coactivator-1alpha. This increases oxidative capacity and also leads to fatty acid retention through upregulation of glycerol-3-phosphate production, and hence increased fatty acid re-esterification. We conclude that prevention or treatment of insulin resistance through alteration of adipocyte fatty acid handling will require more than a simple alteration of the activity of mitochondrial beta-oxidation within normal limits.

  11. Adipocyte differentiation and leptin expression

    DEFF Research Database (Denmark)

    Hwang, C S; Loftus, T M; Mandrup, S

    1997-01-01

    , most notably those of the C/EBP and PPAR families, which combine to regulate each other and to control the expression of adipocyte-specific genes. One such gene, i.e. the obese gene, was recently identified and found to encode a hormone, referred to as leptin, that plays a major role in the regulation...... of energy intake and expenditure. The hormonal and transcriptional control of adipocyte differentiation is discussed, as is the role of leptin and other factors secreted by the adipocyte that participate in the regulation of adipose homeostasis....

  12. Novel nuances of human brown fat

    DEFF Research Database (Denmark)

    Scheele, Camilla; Larsen, Therese Juhlin; Nielsen, Søren

    2014-01-01

    There is a current debate in the literature on whether human fat derived from the supraclavicular region should be classified as brown, or as the white fat-derived less potent, brite/beige. This commentary addresses whether the existing classification defined in mice is sufficient to describe the......, the classification of adipocyte subtypes defined in mice may need reconsideration when applying to humans.......There is a current debate in the literature on whether human fat derived from the supraclavicular region should be classified as brown, or as the white fat-derived less potent, brite/beige. This commentary addresses whether the existing classification defined in mice is sufficient to describe...... the types of thermogenic adipocytes in humans. We recently published a contradictory mRNA expression signature of human supraclavicular fat defined by an upregulation of the brite marker TBX1 along with the classical brown markers ZIC1 and LHX8, as well as genes indicating brown fat activity including UCP1...

  13. Curcumin promotes browning of white adipose tissue in a norepinephrine-dependent way.

    Science.gov (United States)

    Wang, Shan; Wang, Xiuchao; Ye, Zichen; Xu, Chengming; Zhang, Ming; Ruan, Banjun; Wei, Ming; Jiang, Yinghao; Zhang, Ying; Wang, Li; Lei, Xiaoying; Lu, Zifan

    2015-10-16

    Brown adipose tissue converts energy from food into heat via the mitochondrial uncoupling protein UCP1, defending against cold. In some conditions, inducible 'brown-like' adipocytes, also known as beige adipocytes, can develop within white adipose tissue (WAT). These beige adipocytes have characteristics similar to classical brown adipocytes and thus can burn lipids to produce heat. In the current study, we demonstrated that curcumin (50 or 100 mg/kg/day) decreased bodyweight and fat mass without affecting food intake in mice. We further demonstrated that curcumin improves cold tolerance in mice. This effect was possibly mediated by the emergence of beige adipocytes and the increase of thermogenic gene expression and mitochondrial biogenesis in inguinal WAT. In addition, curcumin promotes β3AR gene expression in inguinal WAT and elevates the levels of plasma norepinephrine, a hormone that can induce WAT browning. Taken together, our data suggest that curcumin can potentially prevent obesity by inducing browning of inguinal WAT via the norepinephrine-β3AR pathway.

  14. Novel Browning Agents, Mechanisms, and Therapeutic Potentials of Brown Adipose Tissue

    Directory of Open Access Journals (Sweden)

    Umesh D. Wankhade

    2016-01-01

    Full Text Available Nonshivering thermogenesis is the process of biological heat production in mammals and is primarily mediated by brown adipose tissue (BAT. Through ubiquitous expression of uncoupling protein 1 (Ucp1 on the mitochondrial inner membrane, BAT displays uncoupling of fuel combustion and ATP production in order to dissipate energy as heat. Because of its crucial role in regulating energy homeostasis, ongoing exploration of BAT has emphasized its therapeutic potential in addressing the global epidemics of obesity and diabetes. The recent appreciation that adult humans possess functional BAT strengthens this prospect. Furthermore, it has been identified that there are both classical brown adipocytes residing in dedicated BAT depots and “beige” adipocytes residing in white adipose tissue depots that can acquire BAT-like characteristics in response to environmental cues. This review aims to provide a brief overview of BAT research and summarize recent findings concerning the physiological, cellular, and developmental characteristics of brown adipocytes. In addition, some key genetic, molecular, and pharmacologic targets of BAT/Beige cells that have been reported to have therapeutic potential to combat obesity will be discussed.

  15. PRDM16 represses the type I interferon response in adipocytes to promote mitochondrial and thermogenic programing.

    Science.gov (United States)

    Kissig, Megan; Ishibashi, Jeff; Harms, Matthew J; Lim, Hee-Woong; Stine, Rachel R; Won, Kyoung-Jae; Seale, Patrick

    2017-06-01

    Brown adipose has the potential to counteract obesity, and thus, identifying signaling pathways that regulate the activity of this tissue is of great clinical interest. PRDM16 is a transcription factor that activates brown fat-specific genes while repressing white fat and muscle-specific genes in adipocytes. Whether PRDM16 also controls other gene programs to regulate adipocyte function was unclear. Here, we identify a novel role for PRDM16 in suppressing type I interferon (IFN)-stimulated genes (ISGs), including Stat1, in adipocytes in vitro and in vivo Ectopic activation of type I IFN signaling in brown adipocytes induces mitochondrial dysfunction and reduces uncoupling protein 1 (UCP1) expression. Prdm16-deficient adipose displays an exaggerated response to type I IFN, including higher STAT1 levels and reduced mitochondrial gene expression. Mechanistically, PRDM16 represses ISGs through binding to promoter regions of these genes and blocking the activating function of IFN regulatory factor 1 (IRF1). Together, these data indicate that PRDM16 diminishes responsiveness to type I IFN in adipose cells to promote thermogenic and mitochondrial function. © 2017 The Authors.

  16. Thermogenic activity of UCP1 in human white fat-derived beige adipocytes.

    Science.gov (United States)

    Bartesaghi, Stefano; Hallen, Stefan; Huang, Li; Svensson, Per-Arne; Momo, Remi A; Wallin, Simonetta; Carlsson, Eva K; Forslöw, Anna; Seale, Patrick; Peng, Xiao-Rong

    2015-01-01

    Heat-producing beige/brite (brown-in-white) adipocytes in white adipose tissue have the potential to suppress metabolic disease in mice and hold great promise for the treatment of obesity and type 2 diabetes in humans. Here, we demonstrate that human adipose-derived stromal/progenitor cells (hASCs) from subcutaneous white adipose tissue can be efficiently converted into beige adipocytes. Upon pharmacological activation of peroxisome proliferator-activated receptor-γ, hASC-derived adipocytes activated beige fat-selective genes and a brown/beige fat-selective electron transport chain gene program. Importantly, hASC-derived beige fat cells displayed the bioenergetic characteristics of genuine brown fat cells, including a capacity for increased respiratory uncoupling in response to β-adrenergic agonists. Furthermore, knock-down experiments reveal that the thermogenic capacity of human beige fat cells was entirely dependent on the presence of Uncoupling protein 1. In summary, this study reveals that hASCs can be readily differentiated into beige adipocytes that, upon activation, undergo uncoupling protein 1-dependent thermogenesis.

  17. Central serotonergic neurons activate and recruit thermogenic brown and beige fat and regulate glucose and lipid homeostasis

    DEFF Research Database (Denmark)

    McGlashon, Jacob M; Gorecki, Michelle C; Kozlowski, Amanda E;

    2015-01-01

    diphtheria toxin receptor (DTR) was selectively expressed in central 5-HT neurons. Treatment with diphtheria toxin (DT) eliminated 5-HT neurons and caused loss of thermoregulation, brown adipose tissue (BAT) steatosis, and a >50% decrease in uncoupling protein 1 (Ucp1) expression in BAT and inguinal white...... glucose and lipid homeostasis, in part through recruitment and metabolic activation of brown and beige adipocytes....

  18. p53 is required for brown adipogenic differentiation and has a protective role against diet-induced obesity

    DEFF Research Database (Denmark)

    Molchadsky, A; Ezra, O; Amendola, P G

    2013-01-01

    that p53 is implicated in protection against diet-induced obesity. In striking contrast, our data shows that p53 exerts a positive regulatory effect on brown adipocyte differentiation. Abrogation of p53 function in skeletal muscle committed cells reduced their capacity to differentiate into brown...... adipocytes and histological analysis of brown adipose tissue revealed an impaired morphology in both embryonic and adult p53-null mice. Thus, depending on the specific adipogenic differentiation program, p53 may exert a positive or a negative effect. This cell type dependent regulation reflects an additional...

  19. Adipocyte lipolysis and insulin resistance.

    Science.gov (United States)

    Morigny, Pauline; Houssier, Marianne; Mouisel, Etienne; Langin, Dominique

    2016-06-01

    Obesity-induced insulin resistance is a major risk factor for the development of type 2 diabetes. Basal fat cell lipolysis (i.e., fat cell triacylglycerol breakdown into fatty acids and glycerol in the absence of stimulatory factors) is elevated during obesity and is closely associated with insulin resistance. Inhibition of adipocyte lipolysis may therefore be a promising therapeutic strategy for treating insulin resistance and preventing obesity-associated type 2 diabetes. In this review, we explore the relationship between adipose lipolysis and insulin sensitivity. After providing an overview of the components of fat cell lipolytic machinery, we describe the hypotheses that may support the causality between lipolysis and insulin resistance. Excessive circulating fatty acids may ectopically accumulate in insulin-sensitive tissues and impair insulin action. Increased basal lipolysis may also modify the secretory profile of adipose tissue, influencing whole body insulin sensitivity. Finally, excessive fatty acid release may also worsen adipose tissue inflammation, a well-known parameter contributing to insulin resistance. Partial genetic or pharmacologic inhibition of fat cell lipases in mice as well as short term clinical trials using antilipolytic drugs in humans support the benefit of fat cell lipolysis inhibition on systemic insulin sensitivity and glucose metabolism, which occurs without an increase of fat mass. Modulation of fatty acid fluxes and, putatively, of fat cell secretory pattern may explain the amelioration of insulin sensitivity whereas changes in adipose tissue immune response do not seem involved. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. Enhanced fatty acid oxidation in adipocytes and macrophages reduces lipid-induced triglyceride accumulation and inflammation.

    Science.gov (United States)

    Malandrino, Maria Ida; Fucho, Raquel; Weber, Minéia; Calderon-Dominguez, María; Mir, Joan Francesc; Valcarcel, Lorea; Escoté, Xavier; Gómez-Serrano, María; Peral, Belén; Salvadó, Laia; Fernández-Veledo, Sonia; Casals, Núria; Vázquez-Carrera, Manuel; Villarroya, Francesc; Vendrell, Joan J; Serra, Dolors; Herrero, Laura

    2015-05-01

    Lipid overload in obesity and type 2 diabetes is associated with adipocyte dysfunction, inflammation, macrophage infiltration, and decreased fatty acid oxidation (FAO). Here, we report that the expression of carnitine palmitoyltransferase 1A (CPT1A), the rate-limiting enzyme in mitochondrial FAO, is higher in human adipose tissue macrophages than in adipocytes and that it is differentially expressed in visceral vs. subcutaneous adipose tissue in both an obese and a type 2 diabetes cohort. These observations led us to further investigate the potential role of CPT1A in adipocytes and macrophages. We expressed CPT1AM, a permanently active mutant form of CPT1A, in 3T3-L1 CARΔ1 adipocytes and RAW 264.7 macrophages through adenoviral infection. Enhanced FAO in palmitate-incubated adipocytes and macrophages reduced triglyceride content and inflammation, improved insulin sensitivity in adipocytes, and reduced endoplasmic reticulum stress and ROS damage in macrophages. We conclude that increasing FAO in adipocytes and macrophages improves palmitate-induced derangements. This indicates that enhancing FAO in metabolically relevant cells such as adipocytes and macrophages may be a promising strategy for the treatment of chronic inflammatory pathologies such as obesity and type 2 diabetes.

  1. γ-Oryzanol Enhances Adipocyte Differentiation and Glucose Uptake

    Directory of Open Access Journals (Sweden)

    Chang Hwa Jung

    2015-06-01

    Full Text Available Recent studies show that brown rice improves glucose intolerance and potentially the risk of diabetes, although the underlying molecular mechanisms remain unclear. One of the phytochemicals found in high concentration in brown rice is γ-oryzanol (Orz, a group of ferulic acid esters of phytosterols and triterpene alcohols. Here, we found that Orz stimulated differentiation of 3T3-L1 preadipocytes and increased the protein expression of adipogenic marker genes such as peroxisome proliferator-activated receptor gamma (PPAR-γ and CCAAT/enhanced binding protein alpha (C/EBPα. Moreover, Orz significantly increased the glucose uptake in insulin-resistant cells and translocation of glucose transporter type 4 (GLUT4 from the cytosol to the cell surface. To investigate the mechanism by which Orz stimulated cell differentiation, we examined its effects on cellular signaling of the mammalian target of rapamycin complex 1 (mTORC1, a central mediator of cellular growth and proliferation. The Orz treatment increased mTORC1 kinase activity based on phosphorylation of 70-kDa ribosomal S6 kinase 1 (S6K1. The effect of Orz on adipocyte differentiation was dependent on mTORC1 activity because rapamycin blocks cell differentiation in Orz-treated cells. Collectively, our results indicate that Orz stimulates adipocyte differentiation, enhances glucose uptake, and may be associated with cellular signaling mediated by PPAR-γ and mTORC1.

  2. Brown adipose tissue in cetacean blubber.

    Directory of Open Access Journals (Sweden)

    Osamu Hashimoto

    Full Text Available Brown adipose tissue (BAT plays an important role in thermoregulation in species living in cold environments, given heat can be generated from its chemical energy reserves. Here we investigate the existence of BAT in blubber in four species of delphinoid cetacean, the Pacific white-sided and bottlenose dolphins, Lagenorhynchus obliquidens and Tursiops truncates, and Dall's and harbour porpoises, Phocoenoides dalli and Phocoena phocoena. Histology revealed adipocytes with small unilocular fat droplets and a large eosinophilic cytoplasm intermingled with connective tissue in the innermost layers of blubber. Chemistry revealed a brown adipocyte-specific mitochondrial protein, uncoupling protein 1 (UCP1, within these same adipocytes, but not those distributed elsewhere throughout the blubber. Western blot analysis of extracts from the inner blubber layer confirmed that the immunohistochemical positive reaction was specific to UCP1 and that this adipose tissue was BAT. To better understand the distribution of BAT throughout the entire cetacean body, cadavers were subjected to computed tomography (CT scanning. Resulting imagery, coupled with histological corroboration of fine tissue structure, revealed adipocytes intermingled with connective tissue in the lowest layer of blubber were distributed within a thin, highly dense layer that extended the length of the body, with the exception of the rostrum, fin and fluke regions. As such, we describe BAT effectively enveloping the cetacean body. Our results suggest that delphinoid blubber could serve a role additional to those frequently attributed to it: simple insulation blanket, energy storage, hydrodynamic streamlining or contributor to positive buoyancy. We believe delphinoid BAT might also function like an electric blanket, enabling animals to frequent waters cooler than blubber as an insulator alone might otherwise allow an animal to withstand, or allow animals to maintain body temperature in cool

  3. Brown adipose tissue in cetacean blubber.

    Science.gov (United States)

    Hashimoto, Osamu; Ohtsuki, Hirofumi; Kakizaki, Takehiko; Amou, Kento; Sato, Ryo; Doi, Satoru; Kobayashi, Sara; Matsuda, Ayaka; Sugiyama, Makoto; Funaba, Masayuki; Matsuishi, Takashi; Terasawa, Fumio; Shindo, Junji; Endo, Hideki

    2015-01-01

    Brown adipose tissue (BAT) plays an important role in thermoregulation in species living in cold environments, given heat can be generated from its chemical energy reserves. Here we investigate the existence of BAT in blubber in four species of delphinoid cetacean, the Pacific white-sided and bottlenose dolphins, Lagenorhynchus obliquidens and Tursiops truncates, and Dall's and harbour porpoises, Phocoenoides dalli and Phocoena phocoena. Histology revealed adipocytes with small unilocular fat droplets and a large eosinophilic cytoplasm intermingled with connective tissue in the innermost layers of blubber. Chemistry revealed a brown adipocyte-specific mitochondrial protein, uncoupling protein 1 (UCP1), within these same adipocytes, but not those distributed elsewhere throughout the blubber. Western blot analysis of extracts from the inner blubber layer confirmed that the immunohistochemical positive reaction was specific to UCP1 and that this adipose tissue was BAT. To better understand the distribution of BAT throughout the entire cetacean body, cadavers were subjected to computed tomography (CT) scanning. Resulting imagery, coupled with histological corroboration of fine tissue structure, revealed adipocytes intermingled with connective tissue in the lowest layer of blubber were distributed within a thin, highly dense layer that extended the length of the body, with the exception of the rostrum, fin and fluke regions. As such, we describe BAT effectively enveloping the cetacean body. Our results suggest that delphinoid blubber could serve a role additional to those frequently attributed to it: simple insulation blanket, energy storage, hydrodynamic streamlining or contributor to positive buoyancy. We believe delphinoid BAT might also function like an electric blanket, enabling animals to frequent waters cooler than blubber as an insulator alone might otherwise allow an animal to withstand, or allow animals to maintain body temperature in cool waters during

  4. Ras signalling regulates differentiation and UCP1 expression in models of brown adipogenesis

    DEFF Research Database (Denmark)

    Murholm, Maria; Dixen, Karen; Hansen, Jacob B

    2010-01-01

    on two unrelated models of mouse brown adipocyte differentiation. RESULTS: A constitutively active H-Ras mutant (Ras V12) caused a complete block of adipose conversion, as manifested by a lack of both lipid accumulation and induction of adipocyte gene expression. The Ras V12-mediated impediment......-Ras mutant (Ras N17) did not inhibit differentiation, but led to increased expression of genes important for energy dissipation in brown fat cells, including UCP1. GENERAL SIGNIFICANCE: These data suggest that the intensity of Ras signalling is important for differentiation and UCP1 expression in models...

  5. α-Lipoic acid treatment increases mitochondrial biogenesis and promotes beige adipose features in subcutaneous adipocytes from overweight/obese subjects.

    Science.gov (United States)

    Fernández-Galilea, Marta; Pérez-Matute, Patricia; Prieto-Hontoria, Pedro L; Houssier, Marianne; Burrell, María A; Langin, Dominique; Martínez, J Alfredo; Moreno-Aliaga, María J

    2015-03-01

    α-Lipoic acid (α-Lip) is a natural occurring antioxidant with beneficial anti-obesity properties. The aim of this study was to investigate the putative effects of α-Lip on mitochondrial biogenesis and the acquirement of brown-like characteristics by subcutaneous adipocytes from overweight/obese subjects. Thus, fully differentiated human subcutaneous adipocytes were treated with α-Lip (100 and 250μM) for 24h for studies on mitochondrial content and morphology, mitochondrial DNA (mtDNA) copy number, fatty acid oxidation enzymes and brown/beige characteristic genes. The involvement of the Sirtuin1/Peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (SIRT1/PGC-1α) pathway was also evaluated. Our results showed that α-Lip increased mitochondrial content in cultured human adipocytes as revealed by electron microscopy and by mitotracker green labeling. Moreover, an enhancement in mtDNA content was observed. This increase was accompanied by an up-regulation of SIRT1 protein levels, a decrease in PGC-1α acetylation and up-regulation of Nuclear respiratory factor 1 (Nrf1) and Mitochondrial transcription factor (Tfam) transcription factors. Enhanced oxygen consumption and fatty acid oxidation enzymes, Carnitine palmitoyl transferase 1 and Acyl-coenzyme A oxidase (CPT-1 and ACOX) were also observed. Mitochondria from α-Lip-treated adipocytes exhibited some morphological characteristics of brown mitochondria, and α-Lip also induced up-regulation of some brown/beige adipocytes markers such as cell death-inducing DFFA-like effector a (Cidea) and T-box 1 (Tbx1). Moreover, α-Lip up-regulated PR domain containing 16 (Prdm16) mRNA levels in treated adipocytes. Therefore, our study suggests the ability of α-Lip to promote mitochondrial biogenesis and brown-like remodeling in cultured white subcutaneous adipocytes from overweight/obese donors.

  6. Human adipocytes stimulate invasion of breast cancer MCF-7 cells by secreting IGFBP-2.

    Directory of Open Access Journals (Sweden)

    Chen Wang

    Full Text Available A better understanding of the effects of human adipocytes on breast cancer cells may lead to the development of new treatment strategies. We explored the effects of adipocytes on the migration and invasion of breast cancer cells both in vitro and in vivo.To study the reciprocal effects of adipocytes and cancer cells, we co-cultured human mature adipocytes and breast cancer cells in a system devoid of heterogeneous cell-cell contact. To analyze the factors that were secreted from adipocytes and that affected the invasive abilities of breast cancer cells, we detected different cytokines in various co-culture media. To study the communication of mature adipocytes and breast cancer cells in vivo, we chose 10 metastatic pathologic samples and 10 non-metastatic pathologic samples to do immunostaining.The co-culture media of human MCF-7 breast cancer cells and human mature adipocytes increased motility of MCF-7 cells. In addition, MMP-2 was remarkably up-regulated, whereas E-cadherin was down-regulated in these MCF-7 cells. Based on our co-culture medium chip results, we chose four candidate cytokines and tested their influence on metastasis individually. We found that IGFBP-2 enhanced the invasion ability of MCF-7 cells in vitro more prominently than did the other factors. In vivo, metastatic human breast tumors had higher levels of MMP-2 than did non-metastatic tumor tissue, whereas adipocytes around metastatic breast tumors had higher levels of IGFBP-2 than did adipocytes surrounding non-metastatic breast tumors.IGFBP-2 secreted by mature adipocytes plays a key role in promoting the metastatic ability of MCF-7 breast cancer cells.

  7. Transcriptional networks controlling adipocyte differentiation

    DEFF Research Database (Denmark)

    Siersbæk, R; Mandrup, Susanne

    2011-01-01

    Adipocyte differentiation is regulated by a complex cascade of signals that drive the transcriptional reprogramming of the fibroblastic precursors. Genome-wide analyses of chromatin accessibility and binding of adipogenic transcription factors make it possible to generate "snapshots" of the trans...

  8. Contributions Of Adipocyte Lipid Metabolism To Body Fat Content And Implications For The Treatment Of Obesity

    OpenAIRE

    Marcelin, Genevieve; Chua, Streamson

    2010-01-01

    Obesity is a chronic disease that increases susceptibility to various diseases, particularly cardiovascular dysfunction, type 2 diabetes and some types of cancer. In this review, we highlighted recent evidence in mouse models that support a potential benefit of increasing adipose lipid utilization through stimulating lipolysis in adipose tissue and fatty acid oxidation. Brown adipocyte development within white adipose tissue of humans suggests that mouse models may be applicable to human obes...

  9. Functional modification of adipocytes by grape seed extract impairs their pro-tumorigenic signaling on colon cancer stem cells and the daughter cancer cells.

    Science.gov (United States)

    Kumar, Sushil; Kumar, Dileep; Raina, Komal; Agarwal, Rajesh; Agarwal, Chapla

    2014-10-30

    With global rise in obesity, it is imperative that we identify obesity-driven factors that increase growth and progression of colorectal cancer (CRC), and also discover and develop agents with anti-CRC efficacy under obese conditions. Here in, we investigated grape seed extract (GSE), a well-defined agent with both preventive and anti-CRC efficacy, for its potential to impair pro-tumorigenic signaling of adipocytes on CRC/colon cancer stem cells (CSCs) and associated molecular mechanisms, to control CRC under obese conditions. GSE treatment significantly decreased the growth and invasion promoting effects of both mouse and human adipocytes on CRC cells. Moreover, GSE exerted a direct inhibitory effect, as well as it strongly reduced the growth promoting signals of adipocytes, on colon CSCs. These GSE effects were associated with a decrease in both mRNA and protein levels of various CSC-associated molecules. Notably, GSE effects on adipocytes were not due to changes in lipid content, but by inducing the 'browning' of adipocytes as evidenced by an increase in UCP-1 mRNA level and mitochondriogenesis. Together, these findings, for the first time, suggest the ability of GSE to induce 'brown remodeling' of white adipocytes, which causes functional modification of adipocytes thus impairing their pro-tumorigenic signals on colon CSCs/CRC cells.

  10. The Ontogeny of Brown Adipose Tissue.

    Science.gov (United States)

    Symonds, Michael E; Pope, Mark; Budge, Helen

    2015-01-01

    There are three different types of adipose tissue (AT)-brown, white, and beige-that differ with stage of development, species, and anatomical location. Of these, brown AT (BAT) is the least abundant but has the greatest potential impact on energy balance. BAT is capable of rapidly producing large amounts of heat through activation of the unique uncoupling protein 1 (UCP1) located within the inner mitochondrial membrane. White AT is an endocrine organ and site of lipid storage, whereas beige AT is primarily white but contains some cells that possess UCP1. BAT first appears in the fetus around mid-gestation and is then gradually lost through childhood, adolescence, and adulthood. We focus on the interrelationships between adipocyte classification, anatomical location, and impact of diet in early life together with the extent to which fat development differs between the major species examined. Ultimately, novel dietary interventions designed to reactivate BAT could be possible.

  11. 17β-Estradiol suppresses visceral adipogenesis and activates brown adipose tissue-specific gene expression.

    Science.gov (United States)

    Al-Qahtani, Saad Misfer; Bryzgalova, Galyna; Valladolid-Acebes, Ismael; Korach-André, Marion; Dahlman-Wright, Karin; Efendić, Suad; Berggren, Per-Olof; Portwood, Neil

    2017-01-01

    Both functional ovaries and estrogen replacement therapy (ERT) reduce the risk of type 2 diabetes (T2D). Understanding the mechanisms underlying the antidiabetic effects of 17β-estradiol (E2) may permit the development of a molecular targeting strategy for the treatment of metabolic disease. This study examines how the promotion of insulin sensitivity and weight loss by E2 treatment in high-fat-diet (HFD)-fed mice involve several anti-adipogenic processes in the visceral adipose tissue. Magnetic resonance imaging (MRI) revealed specific reductions in visceral adipose tissue volume in HFD+E2 mice, compared with HFD mice. This loss of adiposity was associated with diminished visceral adipocyte size and reductions in expression of lipogenic genes, adipokines and of the nuclear receptor nr2c2/tr4. Meanwhile, expression levels of adipose triglyceride lipase/pnpla2 and leptin receptor were increased. As mRNA levels of stat3, a transcription factor involved in brown adipose tissue differentiation, were also increased in visceral adipose, the expression of other brown adipose-specific markers was assessed. Both expression and immunohistochemical staining of ucp-1 were increased, and mRNA levels of dio-2, and of adrβ3, a regulator of ucp-1 expression during the thermogenic response, were increased. Furthermore, expression of cpt-1b, a brown adipose-specific gene involved in fatty acid utilization, was also increased. Methylation studies demonstrated that the methylation status of both dio-2 and adrβ3 was significantly reduced. These results show that improved glycemic control and weight loss due to E2 involve anti-adipogenic mechanisms which include suppressed lipogenesis and augmented fatty acid utilization, and in addition, the activation of brown adipose tissue-specific gene expression in association with E2-dependent epigenetic modifications in these genes.

  12. Adeno-Associated Viral Vectors Transduce Mature Human Adipocytes in Three-Dimensional Slice Cultures.

    Science.gov (United States)

    Kallendrusch, Sonja; Schopow, Nikolas; Stadler, Sonja C; Büning, Hildegard; Hacker, Ulrich T

    2016-10-01

    Adipose tissue plays a pivotal role, both in the regulation of energy homeostasis and as an endocrine organ. Consequently, adipose tissue dysfunction is closely related to insulin resistance, morbid obesity, and metabolic syndrome. To study molecular mechanisms and to develop novel therapeutic strategies, techniques are required to genetically modify mature adipocytes. Here, we report on adeno-associated viral (AAV) vectors as a versatile tool to transduce human mature adipocytes in organotypic three-dimensional tissue cultures.

  13. Mature adipocyte-derived dedifferentiated fat cells exhibit multilineage potential.

    Science.gov (United States)

    Matsumoto, Taro; Kano, Koichiro; Kondo, Daisuke; Fukuda, Noboru; Iribe, Yuji; Tanaka, Nobuaki; Matsubara, Yoshiyuki; Sakuma, Takahiro; Satomi, Aya; Otaki, Munenori; Ryu, Jyunnosuke; Mugishima, Hideo

    2008-04-01

    When mature adipocytes are subjected to an in vitro dedifferentiation strategy referred to as ceiling culture, these mature adipocytes can revert to a more primitive phenotype and gain cell proliferative ability. We refer to these cells as dedifferentiated fat (DFAT) cells. In the present study, we examined the multilineage differentiation potential of DFAT cells. DFAT cells obtained from adipose tissues of 18 donors exhibited a fibroblast-like morphology and sustained high proliferative activity. Flow cytometric analysis revealed that DFAT cells comprised a highly homogeneous cell population compared with that of adipose-derived stem/stromal cells (ASCs), although the cell-surface antigen profile of DFAT cells was very similar to that of ASCs. DFAT cells lost expression of mature adipocytes marker genes but retained or gained expression of mesenchymal lineage-committed marker genes such as peroxisome proliferator-activated receptor gamma (PPARgamma), RUNX2, and SOX9. In vitro differentiation analysis revealed that DFAT cells could differentiate into adipocytes, chondrocytes, and osteoblasts under appropriate culture conditions. DFAT cells also formed osteoid matrix when implanted subcutaneously into nude mice. In addition, clonally expanded porcine DFAT cells showed the ability to differentiate into multiple mesenchymal cell lineages. These results indicate that DFAT cells represent a type of multipotent progenitor cell. The accessibility and ease of culture of DFAT cells support their potential application for cell-based therapies.

  14. Pmch-deficiency in rats is associated with normal adipocyte differentiation and lower sympathetic adipose drive.

    Directory of Open Access Journals (Sweden)

    Joram D Mul

    Full Text Available The orexigenic neuropeptide melanin-concentrating hormone (MCH, a product of Pmch, is an important mediator of energy homeostasis. Pmch-deficient rodents are lean and smaller, characterized by lower food intake, body-, and fat mass. Pmch is expressed in hypothalamic neurons that ultimately are components in the sympathetic nervous system (SNS drive to white and interscapular brown adipose tissue (WAT, iBAT, respectively. MCH binds to MCH receptor 1 (MCH1R, which is present on adipocytes. Currently it is unknown if Pmch-ablation changes adipocyte differentiation or sympathetic adipose drive. Using Pmch-deficient and wild-type rats on a standard low-fat diet, we analyzed dorsal subcutaneous and perirenal WAT mass and adipocyte morphology (size and number throughout development, and indices of sympathetic activation in WAT and iBAT during adulthood. Moreover, using an in vitro approach we investigated the ability of MCH to modulate 3T3-L1 adipocyte differentiation. Pmch-deficiency decreased dorsal subcutaneous and perirenal WAT mass by reducing adipocyte size, but not number. In line with this, in vitro 3T3-L1 adipocyte differentiation was unaffected by MCH. Finally, adult Pmch-deficient rats had lower norepinephrine turnover (an index of sympathetic adipose drive in WAT and iBAT than wild-type rats. Collectively, our data indicate that MCH/MCH1R-pathway does not modify adipocyte differentiation, whereas Pmch-deficiency in laboratory rats lowers adiposity throughout development and sympathetic adipose drive during adulthood.

  15. Brown Adipose Tissue and Browning Agents: Irisin and FGF21 in the Development of Obesity in Children and Adolescents.

    Science.gov (United States)

    Pyrżak, B; Demkow, U; Kucharska, A M

    2015-01-01

    In the pediatric population, especially in early infancy, the activity of brown adipose tissue (BAT) is the highest. Further in life BAT is more active in individuals with a lower body mass index and one can expect that BAT is protective against childhood obesity. The development of BAT throughout the whole life can be regulated by genetic, endocrine, and environmental factors. Three distinct adipose depots have been identified: white, brown, and beige adipocytes. The process by which BAT can become beige is still unclear and is an area of intensive research. The "browning agents" increase energy expenditure through the production of heat. Numerous factors known as "browning agents" have currently been described. In humans, recent studies justify a notion of a role of novel myokines: irisin and fibroblast growth factor 21 (FGF21) in the metabolism and development of obesity. This review describes a possible role of irisin and FGF21 in the pathogenesis of obesity in children.

  16. Downregulation of STRA6 in Adipocytes and Adipose Stromovascular Fraction in Obesity and Effects of Adipocyte-Specific STRA6 Knockdown In Vivo

    Science.gov (United States)

    Zemany, Laura; Kraus, Bettina J.; Norseen, Julie; Saito, Tsugumichi; Peroni, Odile D.; Johnson, Randy L.

    2014-01-01

    To investigate the mechanisms by which elevated retinol-binding protein 4 (RBP4) causes insulin resistance, we studied the role of the high-affinity receptor for RBP4, STRA6 (stimulated by retinoic acid), in insulin resistance and obesity. In high-fat-diet-fed and ob/ob mice, STRA6 expression was decreased 70 to 95% in perigonadal adipocytes and both perigonadal and subcutaneous adipose stromovascular cells. To determine whether downregulation of STRA6 in adipocytes contributes to insulin resistance, we generated adipose-Stra6−/− mice. Adipose-Stra6−/− mice fed chow had decreased body weight, fat mass, leptin levels, insulin levels, and adipocyte number and increased expression of brown fat-selective markers in white adipose tissue. When fed a high-fat diet, these mice had a mild improvement in insulin sensitivity at an age when adiposity was unchanged. STRA6 has been implicated in retinol uptake, but retinol uptake and the expression of retinoid homeostatic genes (encoding retinoic acid receptor β [RARβ], CYP26A1, and lecithin retinol acyltransferase) were not altered in adipocytes from adipose-Stra6−/− mice, indicating that retinoid homeostasis was maintained with STRA6 knockdown. Thus, STRA6 reduction in adipocytes in adipose-Stra6−/− mice fed chow resulted in leanness, which may contribute to their increased insulin sensitivity. However, in wild-type mice with high-fat-diet-induced obesity and in ob/ob mice, the marked downregulation of STRA6 in adipocytes and adipose stromovascular cells does not compensate for obesity-associated insulin resistance. PMID:24421389

  17. M1-M2 balancing act in white adipose tissue browning - a new role for RIP140.

    Science.gov (United States)

    Liu, Pu-Ste; Lin, Yi-Wei; Burton, Frank H; Wei, Li-Na

    2015-01-01

    A "Holy Grail" sought in medical treatment of obesity is to be able to biologically reprogram their adipose tissues to burn fat rather than store it. White adipose tissue (WAT) stores fuel and its expansion underlines insulin resistance (IR) whereas brown adipose tissue (BAT) burns fuel and stimulates insulin sensitivity. These two types of fats seesaw within our bodies via a regulatory mechanism that involves intricate communication between adipocytes and blood cells, particularly macrophages that migrate into adipose deposits. The coregulator, Receptor Interacting Protein 140 (RIP140), plays a key role in regulating this communication. In mice on a high-fat diet, the level of RIP140 in macrophages is dramatically elevated to activate their inflammatory M1 polarization and enhance their recruitment into WAT, facilitating IR. Conversely, lowering the level of RIP140 in macrophages not only reduces M1 macrophages but also expands alternatively polarized, anti-inflammatory M2 macrophages, triggering white adipose tissue browning, fat burning, and restoration of insulin sensitivity. This suggests a potential therapeutic strategy for reversing IR, obesity, and atherosclerotic or even cosmetic fat deposits: therapeutic browning of white adipose deposits by diminishing RIP140 levels in macrophages.

  18. Brown-like adipose progenitors derived from human induced pluripotent stem cells: Identification of critical pathways governing their adipogenic capacity

    Science.gov (United States)

    Hafner, Anne-Laure; Contet, Julian; Ravaud, Christophe; Yao, Xi; Villageois, Phi; Suknuntha, Kran; Annab, Karima; Peraldi, Pascal; Binetruy, Bernard; Slukvin, Igor I.; Ladoux, Annie; Dani, Christian

    2016-01-01

    Human induced pluripotent stem cells (hiPSCs) show great promise for obesity treatment as they represent an unlimited source of brown/brite adipose progenitors (BAPs). However, hiPSC-BAPs display a low adipogenic capacity compared to adult-BAPs when maintained in a traditional adipogenic cocktail. The reasons of this feature are unknown and hamper their use both in cell-based therapy and basic research. Here we show that treatment with TGFβ pathway inhibitor SB431542 together with ascorbic acid and EGF were required to promote hiPSCs-BAP differentiation at a level similar to adult-BAP differentiation. hiPSC-BAPs expressed the molecular identity of adult-UCP1 expressing cells (PAX3, CIDEA, DIO2) with both brown (ZIC1) and brite (CD137) adipocyte markers. Altogether, these data highlighted the critical role of TGFβ pathway in switching off hiPSC-brown adipogenesis and revealed novel factors to unlock their differentiation. As hiPSC-BAPs display similarities with adult-BAPs, it opens new opportunities to develop alternative strategies to counteract obesity. PMID:27577850

  19. The effect of non-esterified long-chain fatty acids on blood flow and thermogenesis in brown adipose tissue in the young dog

    DEFF Research Database (Denmark)

    Astrup, A; Bülow, J; Christensen, N J

    1985-01-01

    In vitro experiments have demonstrated that increasing the molar ratio of extracellular non-esterified fatty acids (NEFA) to albumin stimulates thermogenesis in brown adipocytes. To test these results, in vivo blood flow and local temperature were measured in perirenal brown adipose tissue (BAT) ...

  20. MyomiR-133 regulates brown fat differentiation through Prdm16.

    Science.gov (United States)

    Trajkovski, Mirko; Ahmed, Kashan; Esau, Christine C; Stoffel, Markus

    2012-12-01

    Brown adipose tissue (BAT) uses the chemical energy of lipids and glucose to produce heat, a function that can be induced by cold exposure or diet. A key regulator of BAT is the gene encoding PR domain containing 16 (Prdm16), whose expression can drive differentiation of myogenic and white fat precursors to brown adipocytes. Here we show that after cold exposure, the muscle-enriched miRNA-133 is markedly downregulated in BAT and subcutaneous white adipose tissue (SAT) as a result of decreased expression of its transcriptional regulator Mef2. miR-133 directly targets and negatively regulates PRDM16, and inhibition of miR-133 or Mef2 promotes differentiation of precursors from BAT and SAT to mature brown adipocytes, thereby leading to increased mitochondrial activity. Forced expression of miR-133 in brown adipogenic conditions prevents the differentiation to brown adipocytes in both BAT and SAT precursors. Our results point to Mef2 and miR-133 as central upstream regulators of Prdm16 and hence of brown adipogenesis in response to cold exposure in BAT and SAT.

  1. Adipose tissue and adipocyte dysregulation.

    Science.gov (United States)

    Lafontan, M

    2014-02-01

    Obesity-associated insulin resistance is a complex disorder involving a number of candidate molecules, pathways and transduction systems possessing potential causal actions. Inflammation in adipose tissue (AT) is one mechanism proposed to explain the development of insulin resistance, while identification of factors that lead to or cause AT dysfunction when it reaches its limit of expansion represents an important challenge. Pathological expansion of AT is characterized by changes in its blood flow, and the presence of enlarged and dysfunctional adipocytes that begin an inflammatory campaign of altered adipokine and cytokine secretions. Adipocyte senescence, necrosis and death are associated with increased immune cell and macrophage infiltration of AT in obesity. This can boost inflammation and reinforce fat cell dysfunction and death. In addition, pathological fat mass expansion is also related to limited recruitment of fat cell progenitors able to proliferate and differentiate into healthy small fat cells to compensate for cell death and preserve adipocyte numbers. Limiting vascular development and enhancing fibrotic processes worsen inflammation towards chronic irreversibility. The AT expandability hypothesis states that failure of AT expansion is one of the key factors linking positive energy balance and cardiometabolic risks, not obesity per se. Besides the usual treatment of obesity based on behavioral approaches (specific dietary/nutritional approaches together with increased physical activity), a number of questions remain concerning the possible recovery of metabolic health after inflammation-preventing interventions. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  2. Expression and regulation of transcript for the novel transmembrane protein Tmem182 in the adipocyte and muscle lineage

    Directory of Open Access Journals (Sweden)

    Smas Cynthia M

    2008-09-01

    Full Text Available Abstract Background White adipose tissue is not only an energy storage organ; it also functions as an endocrine organ. The coordination and integration of numerous gene expression events is required to establish and maintain the adipocyte phenotype. Findings We previously observed a 45-fold upregulation for a transcript encoding a novel predicted transmembrane protein, Tmem182, upon brown preadipocyte to adipocyte conversion. Here we use real-time PCR analysis to further characterize Tmem182 transcript expression in the adipocyte lineage. Analysis across a panel of 10 murine tissues revealed highest Tmem182 transcript expression in white adipose tissues (WAT, with 10-fold to 20-fold higher levels than in brown adipose tissue (BAT. Tmem182 transcript expression is ~3-fold upregulated in BAT of genetically obese (ob/ob mice vs. wild type C57BL/6. Analysis of three in vitro models of white adipogenesis indicates markedly enriched expression of Tmem182 transcript in adipocytes vs. preadipocytes. Compared to 3T3-L1 preadipocytes, a 157-fold higher level of Tmem182 transcript is detected at 3 day post-induction of adipogenesis and an ~2500-fold higher level in mature 3T3-L1 adipocytes. TNFα treatment of 3T3-L1 adipocytes resulted in a ~90% decrease in Tmem182 transcript level. As skeletal muscle and heart were also found to express Tmem182 transcript, we assessed expression in C2C12 myogenesis and observed a ~770-fold upregulation upon conversion of myoblasts to myocytes. Conclusion WAT is the most prominent site of Tmem182 transcript expression and levels of transcript for Tmem182 are altered in adipose tissues of ob/ob mice and upon exposure of 3T3-L1 adipocytes to the proinflammatory cytokine TNFα. The dramatic upregulation of Tmem182 transcript during in vitro adipogenesis and myogenesis suggests Tmem182 may function in intracellular pathways important in these two cell types.

  3. Sestrin2, a regulator of thermogenesis and mitohormesis in brown adipose tissue

    Directory of Open Access Journals (Sweden)

    Seung-Hyun eRo

    2015-07-01

    Full Text Available Sestrin2 is a stress-inducible protein that functions as an antioxidant and inhibitor of mTOR complex 1. In a recent study, we found that Sestrin2 overexpression in brown adipocytes interfered with normal metabolism by reducing mitochondrial respiration through the suppression of uncoupling protein 1 (UCP1 expression. The metabolic effects of Sestrin2 in brown adipocytes were dependent on its antioxidant activity, and chemical antioxidants produced similar effects in inhibiting UCP1-dependent thermogenesis. These observations suggest that low levels of ROS in brown adipocytes can actually be beneficial and necessary for proper metabolic homeostasis. In addition, considering that Sestrins are ROS-inducible and perform ROS-detoxifying as well as other metabolism-controlling functions, they are potential regulators of mitohormesis. This is a concept in which overall beneficial effects result from low-level oxidative stress stimuli, such as the ones induced by caloric restriction or physical exercise. In this perspective, we incorporate our recent insight obtained from the Sestrin2 study towards a better understanding of the relationship between ROS, Sestrin2 and mitochondrial metabolism in the context of brown adipocyte physiology.

  4. [Brown, white, beige: the color of fat and new therapeutic perspectives for obesity...].

    Science.gov (United States)

    Kuhn, E; Binart, N; Lombès, M

    2012-10-01

    Three articles published in the NEJM in 2009 have renewed the interest for brown adipose tissue (BAT) in humans. This review reports interesting new findings on adipocyte cell types that have been presented at the last meeting of the Endocrine Society in Houston, TX, in June 2012. Many studies have focused on identifying factors involved in brown adipocyte lineage, the site of adaptive thermogenesis. Indeed, the role of the transcription factors, such as PRDM16, in brown adipocyte differentiation has been unambiguously established. Very recently, the concept of "beigeing", defined as the occurrence of thermogenic brown adipocytes in white adipose tissue, has emerged, leading to the identification, by Bruce Spiegelman's group, of a new muscular hormone, called irisin, which is able to stimulate the "beigeing". This finding should convey toward the discovery of new mutations involved in the pathogenesis of obesity and lipodystrophies, and should be translated into innovative therapeutic perspectives. Finally, the nature of BAT innervation has been clarified and the presence of an autoregulatory loop between BAT and notably hypothalamic paraventricular nuclei via the sensory and sympathetic nervous systems has been delineated. These feedback circuits appear to be crucial to control BAT thermogenic activity. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  5. PRDM16 sustains white fat gene expression profile in human adipocytes in direct relation with insulin action.

    Science.gov (United States)

    Moreno-Navarrete, José María; Ortega, Francisco; Moreno, María; Xifra, Gemma; Ricart, Wifredo; Fernández-Real, José Manuel

    2015-04-15

    In the present study, we aimed to evaluate the possible role of PRDM16 in human adipocytes and in whole adipose tissue according to obesity and insulin sensitivity. PRDM16 knockdown (KD) had a dual behavior. While KD in preadipocytes led to enhanced gene expression markers of adipocyte differentiation, PRDM16 KD in fully differentiated adipocytes resulted in decreased adipogenic gene expression and insulin action. In line with KD in adipocytes, PRDM16 was positively associated with the expression of several genes involved in adipogenesis, insulin signaling, mitochondrial function and brown adipocyte-related markers in whole adipose tissue from two independent cohorts. PRDM16 was decreased in obese subjects in relation with the decrease of insulin sensitivity [HOM(AIR) (cohort 1) and M clamp value (cohort 2)]. Rosiglitazone (5 µmol/l) and metformin (5 mmol/l) led to increased PRDM16 mRNA and protein levels in isolated human adipocytes and in whole adipose tissue. In conclusion, PRDM16 might contribute to maintain adipose tissue "white fat" gene expression profile and systemic metabolic homeostasis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Regulation of brown and beige fat by microRNAs.

    Science.gov (United States)

    Chen, Yong; Pan, Ruping; Pfeifer, Alexander

    2017-02-01

    MicroRNAs (miRNAs) are small non-coding RNA molecules consisting of approximately 20 to 22 nucleotides. They play a very important role in the regulation of gene expression. miRNAs can be found in different species and a variety of organs and tissues including adipose tissue. There are two types of adipose tissue in mammals: White adipose tissue (WAT) is the largest energy storage, whereas brown adipose tissue (BAT) dissipates energy to maintain body temperature. BAT was first identified in hibernating animals and newborns as a defense against cold. Later on, it was also discovered in human adults, suggesting its potential role in energy balance and metabolism. Moreover, "brown-like" adipocytes present in WAT depots, so called beige or brite (brown-in-white) cells, were discovered by several groups. In recent years, miRNAs were found to have important regulatory function during brown fat differentiation, brown fat activation and white fat "browning". In this review, we focus on the regulation of brown and beige fat by miRNAs including the role in their differentiation and function, providing evidence for their therapeutic potential in metabolic diseases.

  7. Differentiation of human adipose stromal cells in vitro into insulin-sensitive adipocytes.

    Science.gov (United States)

    Huttala, Outi; Mysore, R; Sarkanen, J R; Heinonen, T; Olkkonen, V M; Ylikomi, T

    2016-10-01

    Adipose tissue-related diseases such as obesity and type 2 diabetes are worldwide epidemics. In order to develop adipose tissue cultures in vitro that mimic more faithfully the in vivo physiology, new well-characterized and publicly accepted differentiation methods of human adipose stem cells are needed. The aims of this study are (1) to improve the existing natural adipose tissue extract (ATE)-based induction method and (2) to study the effects of a differentiation method on insulin responsiveness of the resulting adipocytes. Different induction media were applied on human adipose stromal cell (hASC) monocultures to study the differentiation capacity of the induction media and the functionality of the differentiated adipocytes. Cells were differentiated for 14 days to assess triglyceride accumulation per cell and adipocyte-specific gene expression (PPARγ, adiponectin, AP2, leptin, Glut4, Prdm16, CIDEA, PGC1-α, RIP140, UCP and ADCY5). Insulin response was studied by measuring glucose uptake and inhibition of lipolysis after incubation with 100 or 500 nM insulin. The selected differentiation method included a 3-day induction with ATE, 6 days in serum-free medium supplemented with 1.15 μM insulin and 9.06 μM Troglitazone, followed by 4 days in a defined serum- and insulin-free stimulation medium. This protocol induced prominent general adipocyte gene expression, including markers for both brown and white adipocytes and triglyceride accumulation. Moreover, the cells were sensitive to insulin as observed from increased glucose uptake and inhibition of lipolysis. This differentiation protocol provides a promising approach for the induction of hASC adipogenesis to obtain functional and mature human adipocytes.

  8. 一种新型脂肪细胞:beige细胞%A new type of adipocytes: beige cells

    Institute of Scientific and Technical Information of China (English)

    王相清; 朱慧娟; 龚凤英

    2013-01-01

    最近的研究发现,与传统的白色和棕色脂肪细胞不同,脂肪组织中还存在另外一种新型的脂肪细胞,它们散在分布于白色脂肪组织中,受寒冷刺激或β3肾上腺素能受体激动剂激活后,表现出棕色脂肪细胞的特点,棕色脂肪细胞特异的解耦联蛋白1(UCP1)等基因的表达显著增高,产热和能量消耗能力增强.这一过程被称为“白色脂肪细胞棕色化”,这些细胞被命名为brite(brown to white)细胞或者beige(the intermediate color between white and brown)细胞.由于beige细胞在机体内分布广泛,并具有显著的消耗能量的功能,因此可能成为未来减肥药物开发的靶点.%Recent studies demonstrated that there was a new kind of adipocytes,which were different from traditional white and brown adipocytes.These adipocytes are scattered in the white adipose tissue and could highly express the brown adipocytes specific genes uncoupling protein 1 (UCP1),which promote heat production and energy consumption,when stimulated by the cold or β3 adrenergic receptor agonist.This process is called browning of white adipocytes,and these cells are called brite (brown to white) cells or beige (the intermediate color between white and brown) cells.In light of their potential function in energy consumption and their wide distribution in the body,the beige cells may become new therapeutic targets for antiobesity in the future.

  9. PPARgamma in adipocyte differentiation and metabolism

    DEFF Research Database (Denmark)

    Siersbaek, Rasmus; Nielsen, Ronni; Mandrup, Susanne

    2010-01-01

    Adipocyte differentiation is controlled by a tightly regulated transcriptional cascade in which PPARgamma and members of the C/EBP family are key players. Here we review the roles of PPARgamma and C/EBPs in adipocyte differentiation with emphasis on the recently published genome-wide binding prof...

  10. Controlled cellular energy conversion in brown adipose tissue thermogenesis

    Science.gov (United States)

    Horowitz, J. M.; Plant, R. E.

    1978-01-01

    Brown adipose tissue serves as a model system for nonshivering thermogenesis (NST) since a) it has as a primary physiological function the conversion of chemical energy to heat; and b) preliminary data from other tissues involved in NST (e.g., muscle) indicate that parallel mechanisms may be involved. Now that biochemical pathways have been proposed for brown fat thermogenesis, cellular models consistent with a thermodynamic representation can be formulated. Stated concisely, the thermogenic mechanism in a brown fat cell can be considered as an energy converter involving a sequence of cellular events controlled by signals over the autonomic nervous system. A thermodynamic description for NST is developed in terms of a nonisothermal system under steady-state conditions using network thermodynamics. Pathways simulated include mitochondrial ATP synthesis, a Na+/K+ membrane pump, and ionic diffusion through the adipocyte membrane.

  11. Adipocytes properties and crosstalk with immune system in obesity-related inflammation.

    Science.gov (United States)

    Maurizi, Giulia; Della Guardia, Lucio; Maurizi, Angela; Poloni, Antonella

    2018-01-01

    Obesity is a condition likely associated with several dysmetabolic conditions or worsening of cardiovascular and other chronic disturbances. A key role in this mechanism seem to be played by the onset of low-grade systemic inflammation, highlighting the importance of the interplay between adipocytes and immune system cells. Adipocytes express a complex and highly adaptive biological profile being capable to selectively activate different metabolic pathways in order to respond to environmental stimuli. It has been demonstrated how adipocytes, under appropriate stimulation, can easily differentiate and de-differentiate thereby converting themselves into different phenotypes according to metabolic necessities. Although underlying mechanisms are not fully understood, growing in adipocyte size and the inability of storing triglycerides under overfeeding conditions seem to be crucial for the switching to a dysfunctional metabolic profile, which is characterized by inflammatory and apoptotic pathways activation, and by the shifting to pro-inflammatory adipokines secretion. In obesity, changes in adipokines secretion along with adipocyte deregulation and fatty acids release into circulation contribute to maintain immune cells activation as well as their infiltration into regulatory organs. Over the well-established role of macrophages, recent findings suggest the involvement of new classes of immune cells such as T regulatory lymphocytes and neutrophils in the development inflammation and multi systemic worsening. Deeply understanding the pathways of adipocyte regulation and the de-differentiation process could be extremely useful for developing novel strategies aimed at curbing obesity-related inflammation and related metabolic disorders. © 2017 Wiley Periodicals, Inc.

  12. Isoproterenol Increases Uncoupling, Glycolysis, and Markers of Beiging in Mature 3T3-L1 Adipocytes.

    Science.gov (United States)

    Miller, Colette N; Yang, Jeong-Yeh; England, Emily; Yin, Amelia; Baile, Clifton A; Rayalam, Srujana

    2015-01-01

    Beta-adrenergic activation stimulates uncoupling protein 1 (UCP1), enhancing metabolic rate. In vitro, most work has studied brown adipocytes, however, few have investigated more established adipocyte lines such as the murine 3T3-L1 line. To assess the effect of beta-adrenergic activation, mature 3T3-L1s were treated for 6 or 48 hours with or without isoproterenol (10 and 100 μM) following standard differentiation supplemented with thyroid hormone (T3; 1 nM). The highest dose of isoproterenol increased lipid content following 48 hours of treatment. This concentration enhanced UCP1 mRNA and protein expression. The increase in UCP1 following 48 hours of isoproterenol increased oxygen consumption rate. Further, coupling efficiency of the electron transport chain was disturbed and an enhancement of glycolytic rate was measured alongside this, indicating an attempt to meet the energy demands of the cell. Lastly, markers of beige adipocytes (protein content of CD137 and gene transcript of CITED1) were also found to be upregulated at 48 hours of isoproterenol treatment. This data indicates that mature 3T3-L1 adipocytes are responsive to isoproterenol and induce UCP1 expression and activity. Further, this finding provides a model for further pharmaceutical and nutraceutical investigation of UCP1 in 3T3-L1s.

  13. Isoproterenol Increases Uncoupling, Glycolysis, and Markers of Beiging in Mature 3T3-L1 Adipocytes.

    Directory of Open Access Journals (Sweden)

    Colette N Miller

    Full Text Available Beta-adrenergic activation stimulates uncoupling protein 1 (UCP1, enhancing metabolic rate. In vitro, most work has studied brown adipocytes, however, few have investigated more established adipocyte lines such as the murine 3T3-L1 line. To assess the effect of beta-adrenergic activation, mature 3T3-L1s were treated for 6 or 48 hours with or without isoproterenol (10 and 100 μM following standard differentiation supplemented with thyroid hormone (T3; 1 nM. The highest dose of isoproterenol increased lipid content following 48 hours of treatment. This concentration enhanced UCP1 mRNA and protein expression. The increase in UCP1 following 48 hours of isoproterenol increased oxygen consumption rate. Further, coupling efficiency of the electron transport chain was disturbed and an enhancement of glycolytic rate was measured alongside this, indicating an attempt to meet the energy demands of the cell. Lastly, markers of beige adipocytes (protein content of CD137 and gene transcript of CITED1 were also found to be upregulated at 48 hours of isoproterenol treatment. This data indicates that mature 3T3-L1 adipocytes are responsive to isoproterenol and induce UCP1 expression and activity. Further, this finding provides a model for further pharmaceutical and nutraceutical investigation of UCP1 in 3T3-L1s.

  14. Developmental origins of the adipocyte lineage: new insights from genetics and genomics studies.

    Science.gov (United States)

    Billon, Nathalie; Dani, Christian

    2012-03-01

    The current epidemic of obesity and overweight has caused a surge of interest in the study of adipose tissue formation. Much progress has been made in defining the transcriptional networks controlling the terminal differentiation of adipocyte progenitors into mature adipocytes. However, the early steps of adipocyte development and the embryonic origin of this lineage have been largely disregarded until recently. In mammals, two functionally different types of adipose tissues coexist, which are both involved in energy balance but assume opposite functions. White adipose tissue (WAT) stores energy, while brown adipose tissue (BAT) is specialized in energy expenditure. WAT and BAT can be found as several depots located in various sites of the body. Individual fat depots exhibit different timing of appearance during development, as well as distinct functional properties, suggesting possible differences in their developmental origin. This hypothesis has recently been revisited through large-scale genomics studies and in vivo lineage tracing approaches, which are reviewed in this report. These studies have provided novel fundamental insights into adipocyte biology, pointing out distinct developmental origins for WAT and BAT, as well as for individual WAT depots. They suggest that the adipose tissue is composed of distinct mini-organs, exhibiting developmental and functional differences, as well as variable contribution to obesity-related metabolic diseases.

  15. Diffuse Optical Spectroscopy and Imaging to Detect and Quantify Adipose Tissue Browning

    Science.gov (United States)

    Dinish, U. S; Wong, Chi Lok; Sriram, Sandhya; Ong, Wee Kiat; Balasundaram, Ghayathri; Sugii, Shigeki; Olivo, Malini

    2017-01-01

    Adipose (fat) tissue is a complex metabolic organ that is highly active and essential. In contrast to white adipose tissue (WAT), brown adipose tissue (BAT) is deemed metabolically beneficial because of its ability to burn calories through heat production. The conversion of WAT-resident adipocytes to “beige” or “brown-like” adipocytes has recently attracted attention. However, it typically takes a few days to analyze and confirm this browning of WAT through conventional molecular, biochemical, or histological methods. Moreover, accurate quantification of the overall browning process is not possible by any of these methods. In this context, we report the novel application of diffuse reflectance spectroscopy (DRS) and multispectral imaging (MSI) to detect and quantify the browning process in mice. We successfully demonstrated the time-dependent increase in browning of WAT, following its induction through β-adrenergic agonist injections. The results from these optical techniques were confirmed with those of standard molecular and biochemical assays, which measure gene and protein expression levels of UCP1 and PGC-1α, as well as with histological examinations. We envision that the reported optical methods can be developed into a fast, real time, cost effective and easy to implement imaging approach for quantification of the browning process in adipose tissue. PMID:28145475

  16. Selective Insulin Resistance in Adipocytes*

    Science.gov (United States)

    Tan, Shi-Xiong; Fisher-Wellman, Kelsey H.; Fazakerley, Daniel J.; Ng, Yvonne; Pant, Himani; Li, Jia; Meoli, Christopher C.; Coster, Adelle C. F.; Stöckli, Jacqueline; James, David E.

    2015-01-01

    Aside from glucose metabolism, insulin regulates a variety of pathways in peripheral tissues. Under insulin-resistant conditions, it is well known that insulin-stimulated glucose uptake is impaired, and many studies attribute this to a defect in Akt signaling. Here we make use of several insulin resistance models, including insulin-resistant 3T3-L1 adipocytes and fat explants prepared from high fat-fed C57BL/6J and ob/ob mice, to comprehensively distinguish defective from unaffected aspects of insulin signaling and its downstream consequences in adipocytes. Defective regulation of glucose uptake was observed in all models of insulin resistance, whereas other major actions of insulin such as protein synthesis and anti-lipolysis were normal. This defect corresponded to a reduction in the maximum response to insulin. The pattern of change observed for phosphorylation in the Akt pathway was inconsistent with a simple defect at the level of Akt. The only Akt substrate that showed consistently reduced phosphorylation was the RabGAP AS160 that regulates GLUT4 translocation. We conclude that insulin resistance in adipose tissue is highly selective for glucose metabolism and likely involves a defect in one of the components regulating GLUT4 translocation to the cell surface in response to insulin. PMID:25720492

  17. Selective insulin resistance in adipocytes.

    Science.gov (United States)

    Tan, Shi-Xiong; Fisher-Wellman, Kelsey H; Fazakerley, Daniel J; Ng, Yvonne; Pant, Himani; Li, Jia; Meoli, Christopher C; Coster, Adelle C F; Stöckli, Jacqueline; James, David E

    2015-05-01

    Aside from glucose metabolism, insulin regulates a variety of pathways in peripheral tissues. Under insulin-resistant conditions, it is well known that insulin-stimulated glucose uptake is impaired, and many studies attribute this to a defect in Akt signaling. Here we make use of several insulin resistance models, including insulin-resistant 3T3-L1 adipocytes and fat explants prepared from high fat-fed C57BL/6J and ob/ob mice, to comprehensively distinguish defective from unaffected aspects of insulin signaling and its downstream consequences in adipocytes. Defective regulation of glucose uptake was observed in all models of insulin resistance, whereas other major actions of insulin such as protein synthesis and anti-lipolysis were normal. This defect corresponded to a reduction in the maximum response to insulin. The pattern of change observed for phosphorylation in the Akt pathway was inconsistent with a simple defect at the level of Akt. The only Akt substrate that showed consistently reduced phosphorylation was the RabGAP AS160 that regulates GLUT4 translocation. We conclude that insulin resistance in adipose tissue is highly selective for glucose metabolism and likely involves a defect in one of the components regulating GLUT4 translocation to the cell surface in response to insulin. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Dysfunctional Subcutaneous Fat With Reduced Dicer and Brown Adipose Tissue Gene Expression in HIV-Infected Patients.

    Science.gov (United States)

    Torriani, Martin; Srinivasa, Suman; Fitch, Kathleen V; Thomou, Thomas; Wong, Kimberly; Petrow, Eva; Kahn, C Ronald; Cypess, Aaron M; Grinspoon, Steven K

    2016-03-01

    HIV patients are at an increased risk for cardiometabolic disease secondary to depot-specific alterations in adipose function, but mechanisms remain poorly understood. The endoribonuclease Dicer has been linked to the modulation of brown and white adipocyte differentiation. We previously demonstrated that Dicer knockout mice undergo transformation of brown adipose tissue to white adipose tissue and develop a lipodystrophic phenotype. We hypothesized reduced Dicer and brown adipose tissue gene expression from nonlipomatous sc fat among HIV patients with a lipodystrophic phenotype. Eighteen HIV (nine with and without lipodystrophic changes in fat distribution, characterized by excess dorsocervical adipose tissue [DCAT]) and nine non-HIV subjects underwent punch biopsy of abdominal sc fat to determine expression of Dicer and other adipose-related genes. HIV subjects with long-duration antiretroviral use demonstrated excess DCAT vs non-HIV subjects (9.8 ± 1.0 vs 6.6 ± 0.8 cm(2), P = .02) with similar body mass index. Dicer expression was decreased in abdominal sc fat of HIV vs non-HIV (4.88 [1.91, 11.93] vs 17.69 [10.72, 47.91], P = .01), as were PPARα, ZIC1, PRDM16, DIO2, and HSP60 (all P ≤ .03). Moreover, the expression of Dicer (2.49 [0.02, 4.88] vs 11.20 [4.83, 21.45], P = .006), brown fat (PPARα [P = .002], ZIC1 [P = .004], LHX8 [P = .03], PRDM16 [P = .0008], PAT2 [P = .008], P2RX5 [P = .02]), beige fat (TMEM26 [P = .004], CD137 [P = .008]), and other genes (DIO2 [P = .002], leptin [P = .003], HSP60 [P = .0004]) was further decreased in abdominal sc fat comparing HIV subjects with vs without excess DCAT. Down-regulation of Dicer in the abdominal sc fat correlated with the down-regulation of all brown and beige fat genes (all P ≤ .01). Our results demonstrate dysfunctional sc adipose tissue marked by reduced Dicer in relationship to the down-regulation of brown and beige fat-related genes in lipodystrophic HIV patients and may provide a novel mechanism for

  19. Modelling of the simultaneous photodegradation of Acid Red 97, Acid Orange 61 and Acid Brown 425 using factor screening and response surface strategies.

    Science.gov (United States)

    Fernández, Cristina; Larrechi, M Soledad; Callao, M Pilar

    2010-08-15

    In this paper the influence of seven variables that could be relevant in the photodegradation of three textile dyes - Acid Red 97, Acid Orange 61 and Acid Brown 425 - has been studied with the aim of determining the most efficient conditions for this process. The type and concentration of catalyst, the presence and concentration of H(2)O(2), the stirring, the pH and the dye concentration have been studied as variables. In the first stage the more basic variables were analyzed using a screening methodology (saturated fractional factorial design) and it was concluded that the most influential variable was the presence of H(2)O(2). In the second stage, a central composite design was used to establish a response surface for the behavior of the photodegradation. In this stage the concentration of Acid Brown 425 was fixed and the degradation was carried out without catalyst. The most remarkable aspects of the experiment are that brown dye is always the most persistent in the solution and that a catalyst is not needed to degrade the dyes quickly. A second-order equation is needed to model this process. The response surface obtained could be useful for reducing the time and money needed to treat effluent wastewater. Copyright 2010 Elsevier B.V. All rights reserved.

  20. The β3-adrenergic receptor is dispensable for browning of adipose tissues.

    Science.gov (United States)

    de Jong, Jasper M A; Wouters, René T F; Boulet, Nathalie; Cannon, Barbara; Nedergaard, Jan; Petrovic, Natasa

    2017-02-21

    Brown and brite/beige adipocytes are attractive therapeutic targets to treat metabolic diseases. To maximally utilize their functional potential, further understanding is required about their identities and their functional differences. Recent studies with β3-adrenergic receptor knockout mice reported that brite/beige adipocytes, but not classical brown adipocytes, require the β3-adrenergic receptor for cold-induced transcriptional activation of thermogenic genes. We aimed to further characterize this requirement of the β3-adrenergic receptor as a functional distinction between classical brown and brite/beige adipocytes. However, when comparing wild-type and β3-adrenergic receptor knockout mice, we observed no differences in cold-induced thermogenic gene expression (Ucp1, Pgc1a, Dio2 and Cidea) in brown or white (brite/beige) adipose tissues. Irrespective of the duration of the cold exposure or the sex of the mice, we observed no effect of the absence of the β3-adrenergic receptor. Experiments with the β3-adrenergic receptor agonist CL-316,243 verified the functional absence of β3-adrenergic signaling in these knockout mice. The β3-adrenergic receptor knockout model in the present study was maintained on a FVB/N background, whereas earlier reports used C57BL/6 and 129Sv mice. Thus, our data imply background-dependent differences in adrenergic signaling mechanisms in response to cold exposure. Nonetheless, the present data indicate that the β3-adrenergic receptor is dispensable for cold-induced transcriptional activation in both classical brown and, as opposed to earlier studies, brite/beige cells. This should be taken into account in the increasing number of studies on the induction of browning and their extrapolation to human physiology.

  1. [Human brown adipose tissue].

    Science.gov (United States)

    Virtanen, Kirsi A; Nuutila, Pirjo

    2015-01-01

    Adult humans have heat-producing and energy-consuming brown adipose tissue in the clavicular region of the neck. There are two types of brown adipose cells, the so-called classic and beige adipose cells. Brown adipose cells produce heat by means of uncoupler protein 1 (UCP1) from fatty acids and sugar. By applying positron emission tomography (PET) measuring the utilization of sugar, the metabolism of brown fat has been shown to multiply in the cold, presumably influencing energy consumption. Active brown fat is most likely present in young adults, persons of normal weight and women, least likely in obese persons.

  2. Rutin ameliorates obesity through brown fat activation.

    Science.gov (United States)

    Yuan, Xiaoxue; Wei, Gang; You, Yilin; Huang, Yuanyuan; Lee, Hyuek Jong; Dong, Meng; Lin, Jun; Hu, Tao; Zhang, Hanlin; Zhang, Chuanhai; Zhou, Huiqiao; Ye, Rongcai; Qi, Xiaolong; Zhai, Baiqiang; Huang, Weidong; Liu, Shunai; Xie, Wen; Liu, Qingsong; Liu, Xiaomeng; Cui, Chengbi; Li, Donghao; Zhan, Jicheng; Cheng, Jun; Yuan, Zengqiang; Jin, Wanzhu

    2017-01-01

    Increasing energy expenditure through activation of brown adipose tissue (BAT) is a critical approach to treating obesity and diabetes. In this study, rutin, a natural compound extracted from mulberry and a drug used as a capillary stabilizer clinically for many years without any side effects, regulated whole-body energy metabolism by enhancing BAT activity. Rutin treatment significantly reduced adiposity, increased energy expenditure, and improved glucose homeostasis in both genetically obese (Db/Db) and diet-induced obesity (DIO) mice. Rutin also induced brown-like adipocyte (beige) formation in subcutaneous adipose tissue in both obesity mouse models. Mechanistically, we found that rutin directly bound to and stabilized SIRT1, leading to hypoacetylation of peroxisome proliferator-activated receptor γ coactivator-1α protein, which stimulated Tfam transactivation and eventually augmented the number of mitochondria and UCP1 activity in BAT. These findings reveal that rutin is a novel small molecule that activates BAT and may provide a novel therapeutic approach to the treatment of metabolic disorders.-Yuan, X., Wei, G., You, Y., Huang, Y., Lee, H. J., Dong, M., Lin, J., Hu, T., Zhang, H., Zhang, C., Zhou, H., Ye, R., Qi, X., Zhai, B., Huang, W., Liu, S., Xie, W., Liu, Q., Liu, X., Cui, C., Li, D., Zhan, J., Cheng, J., Yuan, Z., Jin, W. Rutin ameliorates obesity through brown fat activation. © FASEB.

  3. Atmospheres of Brown Dwarfs

    CERN Document Server

    Helling, Christiane

    2014-01-01

    Brown Dwarfs are the coolest class of stellar objects known to date. Our present perception is that Brown Dwarfs follow the principles of star formation, and that Brown Dwarfs share many characteristics with planets. Being the darkest and lowest mass stars known makes Brown Dwarfs also the coolest stars known. This has profound implication for their spectral fingerprints. Brown Dwarfs cover a range of effective temperatures which cause brown dwarfs atmospheres to be a sequence that gradually changes from a M-dwarf-like spectrum into a planet-like spectrum. This further implies that below an effective temperature of < 2800K, clouds form already in atmospheres of objects marking the boundary between M-Dwarfs and brown dwarfs. Recent developments have sparked the interest in plasma processes in such very cool atmospheres: sporadic and quiescent radio emission has been observed in combination with decaying Xray-activity indicators across the fully convective boundary.

  4. AMPK is Involved in Mediation of Erythropoietin Influence on Metabolic Activity and Reactive Oxygen Species Production in White Adipocytes

    OpenAIRE

    Wang, Li; Di, Lijun; Noguchi, Constance Tom

    2014-01-01

    Erythropoietin, discovered for its indispensable role during erythropoiesis, has been used in the therapy for selected red blood cell disorders in erythropoietin-deficient patients. The biological activities of erythropoietin have been found to extend to non-erythroid tissues due to the expression of erythropoietin receptor. We previously demonstrated that erythropoietin promotes metabolic activity and white adipocytes browning to increase mitochondrial function and energy expenditure via per...

  5. Role of ENPP1 on adipocyte maturation.

    Directory of Open Access Journals (Sweden)

    Jian Liang

    Full Text Available BACKGROUND: It is recognized that the ability of adipose tissue to expand in response to energy excess, i.e. adipocyte maturation, is important in determining systemic abnormalities in glucose and lipid metabolism. Ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1, also known as PC-1 has been recently reported to be involved in the pathogenesis of insulin resistance and related diseases. However, its role on adipose tissue physiology as a mechanism of systemic insulin resistance is not understood. This study was performed to evaluate whether ENPP1 is regulated during adipogenesis and whether over-expression in adipocytes can affect adipocyte maturation, a potential novel mechanism of ENPP1-related insulin resistance. METHODOLOGY/PRINCIPAL FINDINGS: ENPP1 expression was found down-regulated during 3T3-L1 maturation, and over-expression of human ENPP1 in 3T3-L1 (pQCXIP-ENPP1 vector resulted in adipocyte insulin resistance and in defective adipocyte maturation. Adipocyte maturation was more efficient in mesenchymal embryonal cells from ENPP1 knockout mice than from wild-type. CONCLUSIONS: We identify ENPP1 as a novel mechanism of defective adipocyte maturation. This mechanism could contribute to the pathogenesis of insulin resistance in absence of obesity.

  6. Functional and anatomical characteristics of the nerve-brown adipose interaction in the rat

    Science.gov (United States)

    Flaim, K. E.; Horowitz, J. M.; Horwitz, B. A.

    1976-01-01

    Experiments were conducted on 12 male rats to study the coupling of signals from the sympathetic nervous system to the brown adipose tissue. Analysis of electron photomicrographs revealed considerable morphological heterogeneity among the nerves entering and leaving the interscapular fat pad. In response to electrical simulation of the nerves, the temperature of the brown fat increased following a rapid but transient temperature drop. Such changes were observed only on the ipsilateral side, indicating that the innervation to the interscapular brown fat of the rat is functionally bilateral rather than diffuse. The finding that brown fat is capable of responding in a graded fashion correlates well with observations suggesting that clusters of brown adipocytes may be electrically coupled.

  7. Inhibition of Notch signaling promotes browning of white adipose tissue and ameliorates obesity.

    Science.gov (United States)

    Bi, Pengpeng; Shan, Tizhong; Liu, Weiyi; Yue, Feng; Yang, Xin; Liang, Xin-Rong; Wang, Jinghua; Li, Jie; Carlesso, Nadia; Liu, Xiaoqi; Kuang, Shihuan

    2014-08-01

    Beige adipocytes in white adipose tissue (WAT) are similar to classical brown adipocytes in that they can burn lipids to produce heat. Thus, an increase in beige adipocyte content in WAT browning would raise energy expenditure and reduce adiposity. Here we report that adipose-specific inactivation of Notch1 or its signaling mediator Rbpj in mice results in browning of WAT and elevated expression of uncoupling protein 1 (Ucp1), a key regulator of thermogenesis. Consequently, as compared to wild-type mice, Notch mutants exhibit elevated energy expenditure, better glucose tolerance and improved insulin sensitivity and are more resistant to high fat diet-induced obesity. By contrast, adipose-specific activation of Notch1 leads to the opposite phenotypes. At the molecular level, constitutive activation of Notch signaling inhibits, whereas Notch inhibition induces, Ppargc1a and Prdm16 transcription in white adipocytes. Notably, pharmacological inhibition of Notch signaling in obese mice ameliorates obesity, reduces blood glucose and increases Ucp1 expression in white fat. Therefore, Notch signaling may be therapeutically targeted to treat obesity and type 2 diabetes.

  8. Revisiting the adipocyte: a model for integration of cytokine signaling in the regulation of energy metabolism.

    Science.gov (United States)

    Rodríguez, Amaia; Ezquerro, Silvia; Méndez-Giménez, Leire; Becerril, Sara; Frühbeck, Gema

    2015-10-15

    Adipose tissue constitutes an extremely active endocrine organ with a network of signaling pathways enabling the organism to adapt to a wide range of different metabolic challenges, such as starvation, stress, infection, and short periods of gross energy excess. The functional pleiotropism of adipose tissue relies on its ability to synthesize and release a huge variety of hormones, cytokines, complement and growth factors, extracellular matrix proteins, and vasoactive factors, collectively termed adipokines. Obesity is associated with adipose tissue dysfunction leading to the onset of several pathologies including type 2 diabetes, dyslipidemia, nonalcoholic fatty liver, or hypertension, among others. The mechanisms underlying the development of obesity and its associated comorbidities include the hypertrophy and/or hyperplasia of adipocytes, adipose tissue inflammation, impaired extracellular matrix remodeling, and fibrosis together with an altered secretion of adipokines. Recently, the potential role of brown and beige adipose tissue in the protection against obesity has been also recognized. In contrast to white adipocytes, which store energy in the form of fat, brown and beige fat cells display energy-dissipating capacity through the promotion of triacylglycerol clearance, glucose disposal, and generation of heat for thermogenesis. Identification of the morphological and molecular changes in white, beige, and brown adipose tissue during weight gain is of utmost relevance for the identification of pharmacological targets for the treatment of obesity and its associated metabolic diseases.

  9. Adipocyte biology in polycystic ovary syndrome.

    Science.gov (United States)

    Barber, T M; Franks, S

    2013-07-05

    Polycystic Ovary Syndrome (PCOS) is a common endocrinopathy that is associated with an adverse metabolic profile including insulin resistance. There is a clear association between obesity, the development of PCOS and the severity of its phenotypic, biochemical and metabolic features. Evidence to support this link includes data from epidemiological, pathophysiological and genetic studies. Given the importance of obesity in the development and manifestation of PCOS, ongoing research into the many facets of adipocyte biology in women with the condition is important and should continue to be a priority. In this review article, we discuss the existing literature on fat distribution, adipokines, adipocyte hypertrophy and adipocyte steroid metabolism in women with PCOS.

  10. Inorganic nitrate promotes the browning of white adipose tissue through the nitrate-nitrite-nitric oxide pathway.

    Science.gov (United States)

    Roberts, Lee D; Ashmore, Tom; Kotwica, Aleksandra O; Murfitt, Steven A; Fernandez, Bernadette O; Feelisch, Martin; Murray, Andrew J; Griffin, Julian L

    2015-02-01

    Inorganic nitrate was once considered an oxidation end product of nitric oxide metabolism with little biological activity. However, recent studies have demonstrated that dietary nitrate can modulate mitochondrial function in man and is effective in reversing features of the metabolic syndrome in mice. Using a combined histological, metabolomics, and transcriptional and protein analysis approach, we mechanistically defined that nitrate not only increases the expression of thermogenic genes in brown adipose tissue but also induces the expression of brown adipocyte-specific genes and proteins in white adipose tissue, substantially increasing oxygen consumption and fatty acid β-oxidation in adipocytes. Nitrate induces these phenotypic changes through a mechanism distinct from known physiological small molecule activators of browning, the recently identified nitrate-nitrite-nitric oxide pathway. The nitrate-induced browning effect was enhanced in hypoxia, a serious comorbidity affecting white adipose tissue in obese individuals, and corrected impaired brown adipocyte-specific gene expression in white adipose tissue in a murine model of obesity. Because resulting beige/brite cells exhibit antiobesity and antidiabetic effects, nitrate may be an effective means of inducing the browning response in adipose tissue to treat the metabolic syndrome.

  11. Bone Marrow Adipocytes Facilitate Fatty Acid Oxidation Activating AMPK and a Transcriptional Network Supporting Survival of Acute Monocytic Leukemia Cells.

    Science.gov (United States)

    Tabe, Yoko; Yamamoto, Shinichi; Saitoh, Kaori; Sekihara, Kazumasa; Monma, Norikazu; Ikeo, Kazuho; Mogushi, Kaoru; Shikami, Masato; Ruvolo, Vivian; Ishizawa, Jo; Hail, Numsen; Kazuno, Saiko; Igarashi, Mamoru; Matsushita, Hiromichi; Yamanaka, Yasunari; Arai, Hajime; Nagaoka, Isao; Miida, Takashi; Hayashizaki, Yoshihide; Konopleva, Marina; Andreeff, Michael

    2017-03-15

    Leukemia cells in the bone marrow must meet the biochemical demands of increased cell proliferation and also survive by continually adapting to fluctuations in nutrient and oxygen availability. Thus, targeting metabolic abnormalities in leukemia cells located in the bone marrow is a novel therapeutic approach. In this study, we investigated the metabolic role of bone marrow adipocytes in supporting the growth of leukemic blasts. Prevention of nutrient starvation-induced apoptosis of leukemic cells by bone marrow adipocytes, as well as the metabolic and molecular mechanisms involved in this process, was investigated using various analytic techniques. In acute monocytic leukemia (AMoL) cells, the prevention of spontaneous apoptosis by bone marrow adipocytes was associated with an increase in fatty acid β-oxidation (FAO) along with the upregulation of PPARγ, FABP4, CD36, and BCL2 genes. In AMoL cells, bone marrow adipocyte coculture increased adiponectin receptor gene expression and its downstream target stress response kinase AMPK, p38 MAPK with autophagy activation, and upregulated antiapoptotic chaperone HSPs. Inhibition of FAO disrupted metabolic homeostasis, increased reactive oxygen species production, and induced the integrated stress response mediator ATF4 and apoptosis in AMoL cells cocultured with bone marrow adipocytes. Our results suggest that bone marrow adipocytes support AMoL cell survival by regulating their metabolic energy balance and that the disruption of FAO in bone marrow adipocytes may be an alternative, novel therapeutic strategy for AMoL therapy. Cancer Res; 77(6); 1453-64. ©2017 AACR.

  12. MicroRNA-455 regulates brown adipogenesis via a novel HIF1an-AMPK-PGC1α signaling network

    DEFF Research Database (Denmark)

    Zhang, Hongbin; Guan, Meiping; Townsend, Kristy L

    2015-01-01

    Brown adipose tissue (BAT) dissipates chemical energy as heat and can counteract obesity. MicroRNAs are emerging as key regulators in development and disease. Combining microRNA and mRNA microarray profiling followed by bioinformatic analyses, we identified miR-455 as a new regulator of brown...... adipogenesis. miR-455 exhibits a BAT-specific expression pattern and is induced by cold and the browning inducer BMP7. In vitro gain- and loss-of-function studies show that miR-455 regulates brown adipocyte differentiation and thermogenesis. Adipose-specific miR-455 transgenic mice display marked browning...... of subcutaneous white fat upon cold exposure. miR-455 activates AMPKα1 by targeting HIF1an, and AMPK promotes the brown adipogenic program and mitochondrial biogenesis. Concomitantly, miR-455 also targets the adipogenic suppressors Runx1t1 and Necdin, initiating adipogenic differentiation. Taken together...

  13. ER Stress and Lipid Metabolism in Adipocytes

    Directory of Open Access Journals (Sweden)

    Beth S. Zha

    2012-01-01

    Full Text Available The role of endoplasmic reticulum (ER stress is a rapidly emerging field of interest in the pathogenesis of metabolic diseases. Recent studies have shown that chronic activation of ER stress is closely linked to dysregulation of lipid metabolism in several metabolically important cells including hepatocytes, macrophages, β-cells, and adipocytes. Adipocytes are one of the major cell types involved in the pathogenesis of the metabolic syndrome. Recent advances in dissecting the cellular and molecular mechanisms involved in the regulation of adipogenesis and lipid metabolism indicate that activation of ER stress plays a central role in regulating adipocyte function. In this paper, we discuss the current understanding of the potential role of ER stress in lipid metabolism in adipocytes. In addition, we touch upon the interaction of ER stress and autophagy as well as inflammation. Inhibition of ER stress has the potential of decreasing the pathology in adipose tissue that is seen with energy overbalance.

  14. Berberine activates thermogenesis in white and brown adipose tissue.

    Science.gov (United States)

    Zhang, Zhiguo; Zhang, Huizhi; Li, Bo; Meng, Xiangjian; Wang, Jiqiu; Zhang, Yifei; Yao, Shuangshuang; Ma, Qinyun; Jin, Lina; Yang, Jian; Wang, Weiqing; Ning, Guang

    2014-11-25

    Obesity develops when energy intake exceeds energy expenditure. Promoting brown adipose tissue formation and function increases energy expenditure and hence may counteract obesity. Berberine (BBR) is a compound derived from the Chinese medicinal plant Coptis chinensis. Here we show that BBR increases energy expenditure, limits weight gain, improves cold tolerance and enhances brown adipose tissue (BAT) activity in obese db/db mice. BBR markedly induces the development of brown-like adipocytes in inguinal, but not epididymal adipose depots. BBR also increases expression of UCP1 and other thermogenic genes in white and BAT and primary adipocytes via a mechanism involving AMPK and PGC-1α. BBR treatment also inhibits AMPK activity in the hypothalamus, but genetic activation of AMPK in the ventromedial nucleus of the hypothalamus does not prevent BBR-induced weight loss and activation of the thermogenic programme. Our findings establish a role for BBR in regulating organismal energy balance, which may have potential therapeutic implications for the treatment of obesity.

  15. Control of Adipocyte Differentiation in Different Fat Depots; Implications for Pathophysiology or Therapy

    Directory of Open Access Journals (Sweden)

    Xiuquan eMa

    2015-01-01

    Full Text Available Adipocyte differentiation and its impact on restriction or expansion of particular adipose tissue depots has physiological and pathophysiological significance in view of the different functions of these depots. Brown or beige fat [BAT] expansion can enhance thermogenesis, lipid oxidation, insulin sensitivity and glucose tolerance; conversely expanded visceral fat [VAT] is associated with insulin resistance, low grade inflammation, dyslipidaemia and cardiometabolic risk. The largest depot, subcutaneous white fat [WAT], has important beneficial characteristics including storage of lipid out of harms way and secretion of adipokines, especially leptin and adiponectin, with positive metabolic effects including lipid oxidation, energy utilisation, enhanced insulin action and an anti-inflammatory role. The absence of these functions in lipodystrophies leads to major metabolic disturbances. An ability to expand WAT adipocyte differentiation would seem an important defence mechanism against the detrimental effects of energy excess and limit harmful accumulation of lipid in ectopic sites, such as liver and muscle.Adipocyte differentiation involves a transcriptional cascade with PPARg being most important in WAT but less so in VAT, with increased angiogenesis also critical. The transcription factor, Islet1, is fairly specific to VAT and in vitro inhibits adipocyte differentiation. The physiological importance of Islet1 requires further study. Basic control of differentiation is similar in BAT but important differences include the effect of PGC-1a on mitochondrial biosynthesis and upregulation of UCP1; also PRDM16 plays a pivotal role in expression of the BAT phenotype.Modulation of the capacity or function of these different adipose tissue depots, by altering adipocyte differentiation or other means, holds promise for interventions that can be helpful in human disease, particularly cardiometabolic disorders associated with the world wide explosion of

  16. Adipocyte induced arterial calcification is prevented with sodium thiosulfate

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Neal X., E-mail: xuechen@iupui.edu [Divison of Nephrology, Indiana University School of Medicine, Indianapolis, IN (United States); O’Neill, Kalisha; Akl, Nader Kassis [Divison of Nephrology, Indiana University School of Medicine, Indianapolis, IN (United States); Moe, Sharon M. [Divison of Nephrology, Indiana University School of Medicine, Indianapolis, IN (United States); Roudebush VA Medical Center, Indianapolis, IN (United States)

    2014-06-20

    Highlights: • High phosphorus can induce calcification of adipocytes, even when fully differentiated. • Adipocytes can induce vascular calcification in an autocrine manner. • Sodium thiosulfate inhibits adipocyte calcification. - Abstract: Background: Calcification can occur in fat in multiple clinical conditions including in the dermis, breasts and in the abdomen in calciphylaxis. All of these are more common in patients with advanced kidney disease. Clinically, hyperphosphatemia and obesity are risk factors. Thus we tested the hypothesis that adipocytes can calcify in the presence of elevated phosphorus and/or that adipocytes exposed to phosphorus can induce vascular smooth muscle cell (VSMC) calcification. Methods: 3T3-L1 preadipocytes were induced into mature adipocytes and then treated with media containing high phosphorus. Calcification was assessed biochemically and PCR performed to determine the expression of genes for osteoblast and adipocyte differentiation. Adipocytes were also co-cultured with bovine VSMC to determine paracrine effects, and the efficacy of sodium thiosulfate was determined. Results: The results demonstrated that high phosphorus induced the calcification of differentiated adipocytes with increased expression of osteopontin, the osteoblast transcription factor Runx2 and decreased expression of adipocyte transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT-enhancer-binding protein α (CEBPα), indicating that high phosphorus led to a phenotypic switch of adipocytes to an osteoblast like phenotype. Sodium thiosulfate, dose dependently decreased adipocyte calcification and inhibited adipocyte induced increase of VSMC calcification. Co-culture studies demonstrated that adipocytes facilitated VSMC calcification partially mediated by changes of secretion of leptin and vascular endothelial growth factor (VEGF) from adipocytes. Conclusion: High phosphorus induced calcification of mature adipocytes, and

  17. Browning of white adipose tissue uncouples glucose uptake from insulin signaling.

    Science.gov (United States)

    Mössenböck, Karin; Vegiopoulos, Alexandros; Rose, Adam J; Sijmonsma, Tjeerd P; Herzig, Stephan; Schafmeier, Tobias

    2014-01-01

    Presence of thermogenically active adipose tissue in adult humans has been inversely associated with obesity and type 2 diabetes. While it had been shown that insulin is crucial for the development of classical brown fat, its role in development and function of inducible brown-in-white (brite) adipose tissue is less clear. Here we show that insulin deficiency impaired differentiation of brite adipocytes. However, adrenergic stimulation almost fully induced the thermogenic program under these settings. Although brite differentiation of adipocytes as well as browning of white adipose tissue entailed substantially elevated glucose uptake by adipose tissue, the capacity of insulin to stimulate glucose uptake surprisingly was not higher in the brite state. Notably, in line with the insulin-independent stimulation of glucose uptake, our data revealed that brite recruitment results in induction of solute carrier family 2 (GLUT-1) expression in adipocytes and inguinal WAT. These results for the first time demonstrate that insulin signaling is neither essential for brite recruitment, nor is it improved in cells or tissues upon browning.

  18. Browning of white adipose tissue uncouples glucose uptake from insulin signaling.

    Directory of Open Access Journals (Sweden)

    Karin Mössenböck

    Full Text Available Presence of thermogenically active adipose tissue in adult humans has been inversely associated with obesity and type 2 diabetes. While it had been shown that insulin is crucial for the development of classical brown fat, its role in development and function of inducible brown-in-white (brite adipose tissue is less clear. Here we show that insulin deficiency impaired differentiation of brite adipocytes. However, adrenergic stimulation almost fully induced the thermogenic program under these settings. Although brite differentiation of adipocytes as well as browning of white adipose tissue entailed substantially elevated glucose uptake by adipose tissue, the capacity of insulin to stimulate glucose uptake surprisingly was not higher in the brite state. Notably, in line with the insulin-independent stimulation of glucose uptake, our data revealed that brite recruitment results in induction of solute carrier family 2 (GLUT-1 expression in adipocytes and inguinal WAT. These results for the first time demonstrate that insulin signaling is neither essential for brite recruitment, nor is it improved in cells or tissues upon browning.

  19. Browning of White Adipose Tissue Uncouples Glucose Uptake from Insulin Signaling

    Science.gov (United States)

    Mössenböck, Karin; Vegiopoulos, Alexandros; Rose, Adam J.; Sijmonsma, Tjeerd P.; Herzig, Stephan; Schafmeier, Tobias

    2014-01-01

    Presence of thermogenically active adipose tissue in adult humans has been inversely associated with obesity and type 2 diabetes. While it had been shown that insulin is crucial for the development of classical brown fat, its role in development and function of inducible brown-in-white (brite) adipose tissue is less clear. Here we show that insulin deficiency impaired differentiation of brite adipocytes. However, adrenergic stimulation almost fully induced the thermogenic program under these settings. Although brite differentiation of adipocytes as well as browning of white adipose tissue entailed substantially elevated glucose uptake by adipose tissue, the capacity of insulin to stimulate glucose uptake surprisingly was not higher in the brite state. Notably, in line with the insulin-independent stimulation of glucose uptake, our data revealed that brite recruitment results in induction of solute carrier family 2 (GLUT-1) expression in adipocytes and inguinal WAT. These results for the first time demonstrate that insulin signaling is neither essential for brite recruitment, nor is it improved in cells or tissues upon browning. PMID:25313899

  20. Insights into an adipocyte whitening program

    OpenAIRE

    Hill, Bradford G.

    2015-01-01

    White adipose tissue plays a critical role in regulating systemic metabolism and can remodel rapidly in response to changes in nutrient availability. Nevertheless, little is known regarding the metabolic changes occurring in adipocytes during obesity. Our laboratory recently addressed this issue in a commonly used, high-fat-diet mouse model of obesity. We found remarkable changes in adipocyte metabolism that occur prior to infiltration of macrophages in expanding adipose tissue. Results of me...

  1. All-trans retinoic acid increases oxidative metabolism in mature adipocytes

    DEFF Research Database (Denmark)

    Mercader, Josep; Madsen, Lise; Felipe, Francisco;

    2007-01-01

    BACKGROUND/AIMS: In rodents, retinoic acid (RA) treatment favors loss of body fat mass and the acquisition of brown fat features in white fat depots. In this work, we sought to examine to what extent these RA effects are cell autonomous or dependent on systemic factors. METHODS: Parameters of lipid...... preceded by an early RA-induced phosphorylation of p38 mitogen-activated protein kinase. UCP1 expression was not induced. CONCLUSION: The results indicate that RA directly favors remodeling of mature 3T3-L1 adipocytes in culture toward increased oxidative metabolism....

  2. Dynamics of Adipocyte Turnover in Humans

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, K; Arner, E; Westermark, P; Bernard, S; Buchholz, B; Bergmann, O; Blomqvist, L; Hoffstedt, J; Naslund, E; Britton, T; Concha, H; Hassan, M; Ryden, M; Frisen, J; Arner, P

    2007-07-16

    Obesity is increasing in an epidemic fashion in most countries and constitutes a public health problem by enhancing the risk for cardiovascular disease and metabolic disorders such as type 2 diabetes. Owing to the increase in obesity, life expectancy may start to decrease in developed countries for the first time in recent history. The factors determining fat mass in adult humans are not fully understood, but increased lipid storage in already developed fat cells is thought to be most important. We show that adipocyte number is a major determinant for the fat mass in adults. However, the number of fat cells stays constant in adulthood in lean and obese and even under extreme conditions, indicating that the number of adipocytes is set during childhood and adolescence. To establish the dynamics within the stable population of adipocytes in adults, we have measured adipocyte turnover by analyzing the integration of {sup 14}C derived from nuclear bomb tests in genomic DNA. Approximately 10% of fat cells are renewed annually at all adult ages and levels of body mass index. Neither adipocyte death nor generation rate is altered in obesity, suggesting a tight regulation of fat cell number that is independent of metabolic profile in adulthood. The high turnover of adipocytes establishes a new therapeutic target for pharmacological intervention in obesity.

  3. Dissecting the brown adipogenic regulatory network using integrative genomics

    Science.gov (United States)

    Pradhan, Rachana N.; Bues, Johannes J.; Gardeux, Vincent; Schwalie, Petra C.; Alpern, Daniel; Chen, Wanze; Russeil, Julie; Raghav, Sunil K.; Deplancke, Bart

    2017-01-01

    Brown adipocytes regulate energy expenditure via mitochondrial uncoupling, which makes them attractive therapeutic targets to tackle obesity. However, the regulatory mechanisms underlying brown adipogenesis are still poorly understood. To address this, we profiled the transcriptome and chromatin state during mouse brown fat cell differentiation, revealing extensive gene expression changes and chromatin remodeling, especially during the first day post-differentiation. To identify putatively causal regulators, we performed transcription factor binding site overrepresentation analyses in active chromatin regions and prioritized factors based on their expression correlation with the bona-fide brown adipogenic marker Ucp1 across multiple mouse and human datasets. Using loss-of-function assays, we evaluated both the phenotypic effect as well as the transcriptomic impact of several putative regulators on the differentiation process, uncovering ZFP467, HOXA4 and Nuclear Factor I A (NFIA) as novel transcriptional regulators. Of these, NFIA emerged as the regulator yielding the strongest molecular and cellular phenotypes. To examine its regulatory function, we profiled the genomic localization of NFIA, identifying it as a key early regulator of terminal brown fat cell differentiation. PMID:28181539

  4. Thyroid hormone status defines brown adipose tissue activity and browning of white adipose tissues in mice.

    Science.gov (United States)

    Weiner, Juliane; Kranz, Mathias; Klöting, Nora; Kunath, Anne; Steinhoff, Karen; Rijntjes, Eddy; Köhrle, Josef; Zeisig, Vilia; Hankir, Mohammed; Gebhardt, Claudia; Deuther-Conrad, Winnie; Heiker, John T; Kralisch, Susan; Stumvoll, Michael; Blüher, Matthias; Sabri, Osama; Hesse, Swen; Brust, Peter; Tönjes, Anke; Krause, Kerstin

    2016-12-12

    The present study aimed to determine the effect of thyroid hormone dysfunction on brown adipose tissue activity and white adipose tissue browning in mice. Twenty randomized female C57BL/6NTac mice per treatment group housed at room temperature were rendered hypothyroid or hyperthyroid. In-vivo small animal (18)F-FDG PET/MRI was performed to determine the effects of hypo- and hyperthyroidism on BAT mass and BAT activity. Ex-vivo(14)C-acetate loading assay and assessment of thermogenic gene and protein expression permitted analysis of oxidative and thermogenic capacities of WAT and BAT of eu-, hyper and hypothyroid mice. (18)F-FDG PET/MRI revealed a lack of brown adipose tissue activity in hypothyroid mice, whereas hyperthyroid mice displayed increased BAT mass alongside enhanced (18)F-FDG uptake. In white adipose tissue of both, hyper- and hypothyroid mice, we found a significant induction of thermogenic genes together with multilocular adipocytes expressing UCP1. Taken together, these results suggest that both the hyperthyroid and hypothyroid state stimulate WAT thermogenesis most likely as a consequence of enhanced adrenergic signaling or compensation for impaired BAT function, respectively.

  5. Cell Volume Regulation and Signaling in 3T3-L1 Pre-adipocytes and Adipocytes

    DEFF Research Database (Denmark)

    Eduardsen, Kathrine; Larsen, Susanne; Novak, Ivana

    2011-01-01

    Caveolae have been implicated in sensing of cell volume perturbations, yet evidence is still limited and findings contradictory. Here, we investigated the possible role of caveolae in cell volume regulation and volume sensitive signaling in an adipocyte system with high (3T3-L1 adipocytes......) and osmotic cell shrinkage (RVI), accompanied by increased swelling-activated taurine efflux. However, caveolin-1 distribution was not detectably altered after osmotic swelling or shrinkage, and caveolae integrity, as studied by cholesterol depletion or expression of dominant negative Cav-1, was not required...... no detectable effect on InsR, yet increased ERK1/2 phosphorylation. In conclusion, differentiated 3T3-L1 adipocytes exhibit greatly accelerated RVD and RVI responses and increased swelling-activated taurine efflux compared to pre-adipocytes. Furthermore, in pre-adipocytes, Cav-1/caveolae integrity...

  6. Father Brown, Selected sories

    NARCIS (Netherlands)

    Chesterton, G.K.

    2005-01-01

    Father Brown, a small, round Catholic priest with a remarkable understanding of the criminal mind, is one of literature's most unusual and endearing detectives, able to solve the strangest crimes in a most fascinating manner. This collection draws from all five Father Brown books, and within their r

  7. File list: His.Adp.05.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Adp.05.AllAg.White_adipocytes mm9 Histone Adipocyte White adipocytes SRX800009 ...http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.05.AllAg.White_adipocytes.bed ...

  8. File list: His.Adp.20.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Adp.20.AllAg.White_adipocytes mm9 Histone Adipocyte White adipocytes SRX800009 ...http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.20.AllAg.White_adipocytes.bed ...

  9. File list: His.Adp.50.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Adp.50.AllAg.White_adipocytes mm9 Histone Adipocyte White adipocytes SRX800009 ...http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.50.AllAg.White_adipocytes.bed ...

  10. File list: His.Adp.10.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Adp.10.AllAg.White_adipocytes mm9 Histone Adipocyte White adipocytes SRX800009 ...http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.10.AllAg.White_adipocytes.bed ...

  11. Microlensing, Brown Dwarfs and GAIA

    CERN Document Server

    Evans, N W

    2014-01-01

    The GAIA satellite can precisely measure the masses of nearby brown dwarfs and lower main sequence stars by the microlensing effect. The scientific yield is maximised if the microlensing event is also followed with ground-based telescopes to provide densely sampled photometry. There are two possible strategies. First, ongoing events can be triggered by photometric or astrometric alerts by GAIA. Second, events can be predicted using known high proper motion stars as lenses. This is much easier, as the location and time of an event can be forecast. Using the GAIA source density, we estimate that the sample size of high proper motion ($>300$ mas yr$^{-1}$) brown dwarfs needed to provide predictable events during the 5 year mission lifetime is surprisingly small, only of the order of a hundred. This is comparable to the number of high proper motion brown dwarfs already known from the work of the UKIDSS Large Area Survey and the all-sky WISE satellite. Provided the relative parallax of the lens and the angular Ein...

  12. Farnesol Has an Anti-obesity Effect in High-Fat Diet-Induced Obese Mice and Induces the Development of Beige Adipocytes in Human Adipose Tissue Derived-Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Hye-Lin Kim

    2017-09-01

    Full Text Available Brown adipocytes dissipate energy as heat and hence have an important therapeutic capacity for obesity. Development of brown-like adipocytes (also called beige is also another attractive target for obesity treatment. Here, we investigated the effect of farnesol, an isoprenoid, on adipogenesis in adipocytes and on the browning of white adipose tissue (WAT as well as on the weight gain of high-fat diet (HFD-induced obese mice. Farnesol inhibited adipogenesis and the related key regulators including peroxisome proliferator-activated receptor γ (PPARγ and CCAAT/enhancer binding protein α through the up-regulation of AMP-activated protein kinase in 3T3-L1 murine adipocytes and human adipose tissue-derived mesenchymal stem cells (hAMSCs. Farnesol markedly increased the expression of uncoupling protein 1 and PPARγ coactivator 1 α in differentiated hAMSCs. In addition, farnesol limited the weight gain in HFD obese mice and induced the development of beige adipocytes in both inguinal and epididymal WAT. These results suggest that farnesol could be a potential therapeutic agent for obesity treatment.

  13. MicroRNA-133 Controls Brown Adipose Determination in Skeletal Muscle Satellite Cells by Targeting Prdm16

    DEFF Research Database (Denmark)

    Yin, Hang; Pasut, Alessandra; Soleimani, Vahab D

    2013-01-01

    (satellite cells) have long been considered uniformly determined toward the myogenic lineage. Here, we report that adult satellite cells give rise to brown adipocytes and that microRNA-133 regulates the choice between myogenic and brown adipose determination by targeting the 3'UTR of Prdm16. Antagonism...... are downregulated in mice exposed to cold, resulting in de novo generation of satellite cell-derived brown adipocytes. Therefore, microRNA-133 represents an important therapeutic target for the treatment of obesity....... of microRNA-133 during muscle regeneration increases uncoupled respiration, glucose uptake, and thermogenesis in local treated muscle and augments whole-body energy expenditure, improves glucose tolerance, and impedes the development of diet-induced obesity. Finally, we demonstrate that miR-133 levels...

  14. The role of mouse Akt2 in insulin-dependent suppression of adipocyte lipolysis in vivo

    Science.gov (United States)

    Koren, Shlomit; DiPilato, Lisa M.; Emmett, Matthew J.; Shearin, Abigail L.; Chu, Qingwei; Monks, Bob; Birnbaum, Morris J.

    2015-01-01

    Aim/hypothesis The release of fatty acids from adipocytes, i.e. lipolysis, is maintained under tight control, primarily by the opposing actions of catecholamines and insulin. A widely accepted model is that insulin antagonises catecholamine-dependent lipolysis through phosphorylation and activation of cAMP phosphodiesterase 3B (PDE3B) by the serine-threonine protein kinase Akt (protein kinase B). Recently, this hypothesis has been challenged, as in cultured adipocytes insulin appears, under some conditions, to suppress lipolysis independently of Akt. Methods To address the requirement for Akt2, the predominant isoform expressed in classic insulin target tissues, in the suppression of fatty acid release in vivo, we assessed lipolysis in mice lacking Akt2. Results In the fed state and following an oral glucose challenge, Akt2 null mice were glucose intolerant and hyperinsulinaemic, but nonetheless exhibited normal serum NEFA and glycerol levels, suggestive of normal suppression of lipolysis. Furthermore, insulin partially inhibited lipolysis in Akt2 null mice during an insulin tolerance test (ITT) and hyperinsulinaemic–euglycaemic clamp, respectively. In support of these in vivo observations, insulin antagonised catecholamine-induced lipolysis in primary brown fat adipocytes from Akt2-deficient nice. Conclusion These data suggest that suppression of lipolysis by insulin in hyperinsulinaemic states can take place in the absence of Akt2. PMID:25740694

  15. Browning of white adipose tissue: role of hypothalamic signaling.

    Science.gov (United States)

    Bi, Sheng; Li, Lin

    2013-10-01

    Two types of fat, white adipose tissue (WAT) and brown adipose tissue (BAT), exist in mammals including adult humans. While WAT stores excess calories and an excessive accumulation of fat causes obesity, BAT dissipates energy to produce heat through nonshivering thermogenesis for protection against cold environments and provides the potential for the development of novel anti-obesity treatments. The hypothalamus plays a central role in the control of energy balance. Specifically, recent observations indicate the importance of the dorsomedial hypothalamus (DMH) in thermoregulation. We have found that the orexigenic neuropeptide Y (NPY) in the DMH has distinct actions in modulating adiposity and BAT thermogenesis. Knockdown of NPY in the DMH elevates the thermogenic activity of classic BAT and promotes the development of brown adipocytes in WAT, leading to increased thermogenesis. These findings identify a novel potential target for combating obesity.

  16. Fucoxanthin exerts differing effects on 3T3-L1 cells according to differentiation stage and inhibits glucose uptake in mature adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seong-Il [Department of Biology, Jeju National University, Jejusi, Jeju 690-756 (Korea, Republic of); Ko, Hee-Chul [Jeju Sasa Industry Development Agency, Jeju National University, Jejusi, Jeju 690-756 (Korea, Republic of); Shin, Hye-Sun; Kim, Hyo-Min; Hong, Youn-Suk [Department of Biology, Jeju National University, Jejusi, Jeju 690-756 (Korea, Republic of); Lee, Nam-Ho [Department of Chemistry, Jeju National University, Jejusi, Jeju 690-756 (Korea, Republic of); Kim, Se-Jae, E-mail: sjkim@jejunu.ac.kr [Department of Biology, Jeju National University, Jejusi, Jeju 690-756 (Korea, Republic of); Jeju Sasa Industry Development Agency, Jeju National University, Jejusi, Jeju 690-756 (Korea, Republic of)

    2011-06-17

    Highlights: {yields} Fucoxanthin enhances 3T3-L1 adipocyte differentiation at an early stage. {yields} Fucoxanthin inhibits 3T3-L1 adipocyte differentiation at intermediate and late stages. {yields} Fucoxanthin attenuates glucose uptake by inhibiting the phosphorylation of IRS in mature 3T3-L1 adipocytes. {yields} Fucoxanthin exerts its anti-obesity effect by inhibiting the differentiation of adipocytes at both intermediate and late stages, as well as glucose uptake in mature adipocytes. -- Abstract: Progression of 3T3-L1 preadipocyte differentiation is divided into early (days 0-2, D0-D2), intermediate (days 2-4, D2-D4), and late stages (day 4 onwards, D4-). In this study, we investigated the effects of fucoxanthin, isolated from the edible brown seaweed Petalonia binghamiae, on adipogenesis during the three differentiation stages of 3T3-L1 preadipocytes. When fucoxanthin was applied during the early stage of differentiation (D0-D2), it promoted 3T3-L1 adipocyte differentiation, as evidenced by increased triglyceride accumulation. At the molecular level, fucoxanthin increased protein expression of peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}), CCAAT/enhancer-binding protein {alpha} (C/EBP{alpha}), sterol regulatory element-binding protein 1c (SREBP1c), and aP2, and adiponectin mRNA expression, in a dose-dependent manner. However, it reduced the expression of PPAR{gamma}, C/EBP{alpha}, and SREBP1c during the intermediate (D2-D4) and late stages (D4-D7) of differentiation. It also inhibited the uptake of glucose in mature 3T3-L1 adipocytes by reducing the phosphorylation of insulin receptor substrate 1 (IRS-1). These results suggest that fucoxanthin exerts differing effects on 3T3-L1 cells of different differentiation stages and inhibits glucose uptake in mature adipocytes.

  17. Marilyn Levine: "Brown Boots, Leather Laces."

    Science.gov (United States)

    Williams, Ray

    1988-01-01

    Presents a lesson plan which uses Marilyn Levine's "Brown Boots, Leather Laces" to introduce students in grades 10-12 to naturalistic representation and the "trompe l'oeil" artistic tradition. Discusses Levine's background. Includes instructional strategies and student objectives, as well as a photograph of the artwork. (GEA)

  18. Adipocyte insulin receptor activity maintains adipose tissue mass and lifespan.

    Science.gov (United States)

    Friesen, Max; Hudak, Carolyn S; Warren, Curtis R; Xia, Fang; Cowan, Chad A

    2016-08-05

    Type 2 diabetes follows a well-defined progressive pathogenesis, beginning with insulin resistance in metabolic tissues such as the adipose. Intracellular signaling downstream of insulin receptor activation regulates critical metabolic functions of adipose tissue, including glucose uptake, lipogenesis, lipolysis and adipokine secretion. Previous studies have used the aP2 promoter to drive Cre recombinase expression in adipose tissue. Insulin receptor (IR) knockout mice created using this aP2-Cre strategy (FIRKO mice) were protected from obesity and glucose intolerance. Later studies demonstrated the promiscuity of the aP2 promoter, casting doubts upon the tissue specificity of aP2-Cre models. It is our goal to use the increased precision of the Adipoq promoter to investigate adipocyte-specific IR function. Towards this end we generated an adipocyte-specific IR knockout (AIRKO) mouse using an Adipoq-driven Cre recombinase. Here we report AIRKO mice are less insulin sensitive throughout life, and less glucose tolerant than wild-type (WT) littermates at the age of 16 weeks. In contrast to WT littermates, the insulin sensitivity of AIRKO mice is unaffected by age or dietary regimen. At any age, AIRKO mice are comparably insulin resistant to old or obese WT mice and have a significantly reduced lifespan. Similar results were obtained when these phenotypes were re-examined in FIRKO mice. We also found that the AIRKO mouse is protected from high-fat diet-induced weight gain, corresponding with a 90% reduction in tissue weight of major adipose depots compared to WT littermates. Adipose tissue mass reduction is accompanied by hepatomegaly and increased hepatic steatosis. These data indicate that adipocyte IR function is crucial to systemic energy metabolism and has profound effects on adiposity, hepatic homeostasis and lifespan. Copyright © 2016. Published by Elsevier Inc.

  19. Cold-Inducible SIRT6 Regulates Thermogenesis of Brown and Beige Fat

    Directory of Open Access Journals (Sweden)

    Lu Yao

    2017-07-01

    Full Text Available Promoting development and function of brown and beige fat may reduce obesity. Here, we show that fat SIRT6 expression is markedly induced by cold exposure and a β-adrenergic agonist. Deletion of SIRT6 in adipose tissue impairs the thermogenic function of brown adipocytes, causing a morphological “whitening” of brown fat, reduced oxygen (O2 consumption, obesity, decreased core body temperature, and cold sensitivity. Fat SIRT6-deleted mice exhibit increased blood glucose levels, severe insulin resistance, and hepatic steatosis. Moreover, SIRT6 deficiency inhibits the browning of white adipose tissue (WAT following cold exposure or β3-agonist treatment. Depletion of SIRT6 expression in brown adipocytes reduces expression of thermogenic genes, causing a reduction in cellular respiration. Conversely, SIRT6 overexpression in primary fat cells stimulates the thermogenic program. Mechanistically, SIRT6 interacts with and promotes phospho-ATF2 binding to the PGC-1α gene promoter to activate its expression. The present study reveals a critical role for SIRT6 in regulating thermogenesis of fat.

  20. Berberine attenuates autophagy in adipocytes by targeting BECN1

    OpenAIRE

    Deng, Yujie; Xu, Jun; Zhang, Xiaoyan; Yang, Jian; Zhang, Di; Huang, Jian; Lv, Pengfei; Shen, Weili; Yang, Ying

    2014-01-01

    The lysosomal degradation pathway, autophagy, is essential for the maintenance of cellular homeostasis. Recently, autophagy has been demonstrated to be required in the process of adipocyte conversion. However, its role in mature adipocytes under physiological and pathological conditions remains unclear. Here, we report a major function of BECN1 in the regulation of basal autophagy in mature adipocytes. We also show that berberine, a natural plant alkaloid, inhibits basal autophagy in adipocyt...

  1. Take-over: multiple mechanisms of inter-adipocyte communication

    Institute of Scientific and Technical Information of China (English)

    Günter Müller

    2011-01-01

    Adipose tissue mass in mammals is thought to expand with an increase in both volume and total number of the adipocytes. Recent findings suggest that in normal-weight as well as obese individuals, the adipocyte number is set during adolescence prior to adulthood, whereas the subsequent increase in size predominantly drives obesity. The simultaneous existence of large and small adipocytes and their unsynchronized growth, even within the same adipose tissue depot, argues against simple filling-up of emerging adipocytes with lipids and lipid droplets (LDs). Consequently, it is tempting to speculate about signals sent by large adipocytes to order small adipocytes the take-over of the burden of lipid loading. Currently there is experimental evidence for three distinct types of inter-adipocyte signals, i.e, cell-to-cell contacts, adipokines, and other soluble factors and microvesicles. Very recently,microvesicles have been shown (i) to harbour the glycosylphosphatidylinositol-anchored (c)AMP-degrading phosphodiesterase Gce1 and 5'-nucleotidase CD73, (ii) to be released from large adipocytes, (iii) to interact with small adipocytes, and (iv) to transfer Gce1 and CD73 to plasma membranes and LDs of small adipocytes where they degrade (c)AMP. This sequence of events leads to the up-regulation of lipid storage in small adipocytes in response to the microvesicle-encoded 'take-over' signal from large adipocytes. A model is proposed for the maturation of small adipocytes driven by large ones along a gradient of those inter-adipocyte signals.Pharmacological modulation of inter-adipocyte communication and thereby adipocyte maturation may be useful for the therapy of metabolic diseases.

  2. Insights into an adipocyte whitening program.

    Science.gov (United States)

    Hill, Bradford G

    2015-01-01

    White adipose tissue plays a critical role in regulating systemic metabolism and can remodel rapidly in response to changes in nutrient availability. Nevertheless, little is known regarding the metabolic changes occurring in adipocytes during obesity. Our laboratory recently addressed this issue in a commonly used, high-fat-diet mouse model of obesity. We found remarkable changes in adipocyte metabolism that occur prior to infiltration of macrophages in expanding adipose tissue. Results of metabolomic analyses, adipose tissue respirometry, electron microscopy, and expression analyses of key genes and proteins revealed dysregulation of several metabolic pathways, loss of mitochondrial biogenetic capacity, and apparent activation of mitochondrial autophagy which were followed in time by downregulation of numerous mitochondrial proteins important for maintaining oxidative capacity. These findings demonstrate the presence of an adipocyte whitening program that may be critical for regulating adipose tissue remodeling under conditions of chronic nutrient excess.

  3. Berardinelli-seip congenital lipodystrophy 2/seipin is a cell-autonomous regulator of lipolysis essential for adipocyte differentiation.

    Science.gov (United States)

    Chen, Weiqin; Chang, Benny; Saha, Pradip; Hartig, Sean M; Li, Lan; Reddy, Vasumathi Theegala; Yang, Yisheng; Yechoor, Vijay; Mancini, Michael A; Chan, Lawrence

    2012-03-01

    Mutations in BSCL2 underlie human congenital generalized lipodystrophy. We inactivated Bscl2 in mice to examine the mechanisms whereby absence of Bscl2 leads to adipose tissue loss and metabolic disorders. Bscl2(-/-) mice develop severe lipodystrophy of white adipose tissue (WAT), dyslipidemia, insulin resistance, and hepatic steatosis. In vitro differentiation of both Bscl2(-/-) murine embryonic fibroblasts (MEFs) and stromal vascular cells (SVCs) reveals normal early-phase adipocyte differentiation but a striking failure in terminal differentiation due to unbridled cyclic AMP (cAMP)-dependent protein kinase A (PKA)-activated lipolysis, which leads to loss of lipid droplets and silencing of the expression of adipose tissue-specific transcription factors. Importantly, such defects in differentiation can be largely rescued by inhibitors of lipolysis but not by a gamma peroxisome proliferator-activated receptor (PPARγ) agonist. The residual epididymal WAT (EWAT) in Bscl2(-/-) mice displays enhanced lipolysis. It also assumes a "brown-like" phenotype with marked upregulation of UCP1 and other brown adipose tissue-specific markers. Together with decreased Pref1 but increased C/EBPβ levels, these changes highlight a possible increase in cAMP signaling that impairs terminal adipocyte differentiation in the EWAT of Bscl2(-/-) mice. Our study underscores the fundamental role of regulated cAMP/PKA-mediated lipolysis in adipose differentiation and identifies Bscl2 as a novel cell-autonomous determinant of activated lipolysis essential for terminal adipocyte differentiation.

  4. Endocrine modulators of mouse subcutaneous adipose tissue beige adipocyte markers

    Science.gov (United States)

    The stromal vascular fraction (SVF) of subcutaneous adipose tissue contains precursors that can give rise to beige adipocytes. Beige adipocytes are characterized by the expression of specific markers, but it is not clear which markers best evaluate beige adipocyte differentiation. Both regulators of...

  5. Application of adipocyte-derived stem cells in treatment of cutaneous radiation syndrome.

    Science.gov (United States)

    Riccobono, Diane; Agay, Diane; Scherthan, Harry; Forcheron, Fabien; Vivier, Mylène; Ballester, Bruno; Meineke, Viktor; Drouet, Michel

    2012-08-01

    Cutaneous radiation syndrome caused by local high dose irradiation is characterized by delayed outcome and incomplete healing. Recent therapeutic management of accidentally irradiated burn patients has suggested the benefit of local cellular therapy using mesenchymal stem cell grafting. According to the proposed strategy of early treatment, large amounts of stem cells would be necessary in the days following exposure and hospitalization, which would require allogeneic stem cells banking. In this context, the authors compared the benefit of local autologous and allogeneic adipocyte-derived stem cell injection in a large animal model. Minipigs were locally irradiated using a 60Co gamma source at a dose of 50 Gy and divided into three groups. Two groups were grafted with autologous (n = 5) or allogeneic (n = 5) adipocyte-derived stem cells four times after the radiation exposure, whereas the control group received the vehicle without cells (n = 8). A clinical score was elaborated to compare the efficiency of the three treatments. All controls exhibited local inflammatory injuries leading to a persistent painful necrosis, thus mimicking the clinical evolution in human victims. In the autologous adipocyte-derived stem cells group, skin healing without necrosis or uncontrollable pain was observed. In contrast, the clinical outcome was not significantly different in the adipocyte-derived stem cell allogeneic group when compared with controls. This study suggests that autologous adipocyte-derived stem cell grafting improves cutaneous radiation syndrome wound healing, whereas allogeneic adipocyte derived stem cells do not. Further studies will establish whether manipulation of allogeneic stem cells will improve their therapeutic potential.

  6. The Gustatory Signaling Pathway and Bitter Taste Receptors Affect the Development of Obesity and Adipocyte Metabolism in Mice.

    Directory of Open Access Journals (Sweden)

    Bert Avau

    Full Text Available Intestinal chemosensory signaling pathways involving the gustatory G-protein, gustducin, and bitter taste receptors (TAS2R have been implicated in gut hormone release. Alterations in gut hormone profiles may contribute to the success of bariatric surgery. This study investigated the involvement of the gustatory signaling pathway in the development of diet-induced obesity and the therapeutic potential of targeting TAS2Rs to induce body weight loss. α-gustducin-deficient (α-gust-/- mice became less obese than wild type (WT mice when fed a high-fat diet (HFD. White adipose tissue (WAT mass was lower in α-gust-/- mice due to increased heat production as a result of increases in brown adipose tissue (BAT thermogenic activity, involving increased protein expression of uncoupling protein 1. Intra-gastric treatment of obese WT and α-gust-/- mice with the bitter agonists denatonium benzoate (DB or quinine (Q during 4 weeks resulted in an α-gustducin-dependent decrease in body weight gain associated with a decrease in food intake (DB, but not involving major changes in gut peptide release. Both WAT and 3T3-F442A pre-adipocytes express TAS2Rs. Treatment of pre-adipocytes with DB or Q decreased differentiation into mature adipocytes. In conclusion, interfering with the gustatory signaling pathway protects against the development of HFD-induced obesity presumably through promoting BAT activity. Intra-gastric bitter treatment inhibits weight gain, possibly by directly affecting adipocyte metabolism.

  7. Fucoidan from Marine Brown Algae Inhibits Lipid Accumulation

    Directory of Open Access Journals (Sweden)

    Changhyun Roh

    2011-08-01

    Full Text Available In this study, we elucidated the inhibitory effect of fucoidan from marine brown algae on the lipid accumulation in differentiated 3T3-L1 adipocytes and its mechanism. The treatment of fucoidan in a dose-dependent manner was examined on lipid inhibition in 3T3-L1 cells by using Oil Red O staining. Fucoidan showed high lipid inhibition activity at 200 µg/mL concentration (P < 0.001. Lipolytic activity in adipocytes is highly dependent on hormone sensitive lipase (HSL, which is one of the most important targets of lipolytic regulation. Here, we examined the biological response of fucoidan on the protein level of lipolysis pathway. The expressed protein levels of total hormone sensitive lipase (HSL and its activated form, phosphorylated-HSL were significantly increased at concentration of 200 µg/mL fucoidan. Furthermore, insulin-induced 2-deoxy-D-[3H] glucose uptake was decreased up to 51% in fucoidan-treated cells as compared to control. Since increase of HSL and p-HSL expression and decrease of glucose uptake into adipocytes are known to lead to stimulation of lipolysis, our results suggest that fucoidan reduces lipid accumulation by stimulating lipolysis. Therefore, these results suggest that fucoidan can be useful for the prevention or treatment of obesity due to its stimulatory lipolysis.

  8. Apolipoprotein E promotes lipid accumulation and differentiation in human adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Lasrich, Dorothee; Bartelt, Alexander [Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Grewal, Thomas, E-mail: thomas.grewal@sydney.edu.au [Faculty of Pharmacy A15, The University of Sydney, Sydney, NSW 2006 (Australia); Heeren, Joerg, E-mail: heeren@uke.de [Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany)

    2015-09-10

    Several studies in mice indicate a role for apolipoprotein E (APOE) in lipid accumulation and adipogenic differentiation in adipose tissue. However, little is yet known if APOE functions in a similar manner in human adipocytes. This prompted us to compare lipid loading and expression of adipocyte differentiation markers in APOE-deficient and control adipocytes using the differentiated human mesenchymal stem cell line hMSC-Tert as well as primary human and mouse adipocytes as model systems. Differentiated hMSC-Tert were stably transduced with or without siRNA targeting APOE while murine adipocytes were isolated from wild type and Apoe knockout mice. Human APOE knockdown hMSC-Tert adipocytes accumulated markedly less triglycerides compared to control cells. This correlated with strongly decreased gene expression levels of adipocyte markers such as adiponectin (ADIPOQ) and fatty acid binding protein 4 (FABP4) as well as the key transcription factor driving adipocyte differentiation, peroxisome proliferator activator receptor gamma (PPARG), in particular the PPARG2 isoform. Similarly, differentiation of murine Apoe-deficient adipocytes was characterized by reduced gene expression of Adipoq, Fabp4 and Pparg. Interestingly, incubation of APOE-deficient hMSC-Tert adipocytes with conditioned media from APOE3-overexpressing adipocytes or APOE-containing Very Low Density Lipoprotein (VLDL) partially restored triglyceride accumulation, but were unable to induce adipocyte differentiation, as judged by expression of adipocyte markers. Taken together, depletion of endogenous APOE in human adipocytes severely impairs lipid accumulation, which is associated with an inability to initiate differentiation. - Highlights: • Immortalized human mesenchymal stem cells were used to study adipocyte development. • Knockdown of endogenous APOE lead to impaired lipid accumulation and adipogenesis. • APOE supplementation partially restored lipid accumulation but not differentiation.

  9. Modulation of chromatin access during adipocyte differentiation

    DEFF Research Database (Denmark)

    Mandrup, Susanne; Hager, Gordon L

    2012-01-01

    Cellular development requires reprogramming of the genome to modulate the gene program of the undifferentiated cell and allow expression of the gene program unique to differentiated cells. A number of key transcription factors involved in this reprogramming of preadipocytes to adipocytes have bee...

  10. Effects of parabens on adipocyte differentiation.

    Science.gov (United States)

    Hu, Pan; Chen, Xin; Whitener, Rick J; Boder, Eric T; Jones, Jeremy O; Porollo, Aleksey; Chen, Jiangang; Zhao, Ling

    2013-01-01

    Parabens are a group of alkyl esters of p-hydroxybenzoic acid that include methylparaben, ethylparaben, propylparaben, butylparaben, and benzylparaben. Paraben esters and their salts are widely used as preservatives in cosmetics, toiletries, food, and pharmaceuticals. Humans are exposed to parabens through the use of such products from dermal contact, ingestion, and inhalation. However, research on the effects of parabens on health is limited, and the effects of parabens on adipogenesis have not been systematically studied. Here, we report that (1) parabens promote adipogenesis (or adipocyte differentiation) in murine 3T3-L1 cells, as revealed by adipocyte morphology, lipid accumulation, and mRNA expression of adipocyte-specific markers; (2) the adipogenic potency of parabens is increased with increasing length of the linear alkyl chain in the following potency ranking order: methyl- parabens, and the structurally related benzoic acid (without the OH group) are inactive in promoting 3T3-L1 adipocyte differentiation; (3) parabens activate glucocorticoid receptor and/or peroxisome proliferator-activated receptor γ in 3T3-L1 preadipocytes; however, no direct binding to, or modulation of, the ligand binding domain of the glucocorticoid receptor by parabens was detected by glucocorticoid receptor competitor assays; and lastly, (4) parabens, butyl- and benzylparaben in particular, also promote adipose conversion of human adipose-derived multipotent stromal cells. Our results suggest that parabens may contribute to obesity epidemic, and the role of parabens in adipogenesis in vivo needs to be examined further.

  11. Adrenoceptors promote glucose uptake into adipocytes and muscle by an insulin-independent signaling pathway involving mechanistic target of rapamycin complex 2.

    Science.gov (United States)

    Mukaida, Saori; Evans, Bronwyn A; Bengtsson, Tore; Hutchinson, Dana S; Sato, Masaaki

    2017-02-01

    Uptake of glucose into skeletal muscle and adipose tissue plays a vital role in metabolism and energy balance. Insulin released from β-islet cells of the pancreas promotes glucose uptake in these target tissues by stimulating translocation of GLUT4 transporters to the cell surface. This process is complex, involving signaling proteins including the mechanistic (or mammalian) target of rapamycin (mTOR) and Akt that intersect with multiple pathways controlling cell survival, growth and proliferation. mTOR exists in two forms, mTOR complex 1 (mTORC1), and mTOR complex 2 (mTORC2). mTORC1 has been intensively studied, acting as a key regulator of protein and lipid synthesis that integrates cellular nutrient availability and energy balance. Studies on mTORC2 have focused largely on its capacity to activate Akt by phosphorylation at Ser473, however recent findings demonstrate a novel role for mTORC2 in cellular glucose uptake. For example, agonists acting at β2-adrenoceptors (ARs) in skeletal muscle or β3-ARs in brown adipose tissue increase glucose uptake in vitro and in vivo via mechanisms dependent on mTORC2 but not Akt. In this review, we will focus on the signaling pathways downstream of β-ARs that promote glucose uptake in skeletal muscle and brown adipocytes, and will highlight how the insulin and adrenergic pathways converge and interact in these cells. The identification of insulin-independent mechanisms that promote glucose uptake should facilitate novel treatment strategies for metabolic disease.

  12. Lipoprotein lipase release from BFC-1 beta adipocytes. Effects of triglyceride-rich lipoproteins and lipolysis products.

    Science.gov (United States)

    Sasaki, A; Goldberg, I J

    1992-07-25

    Lipoprotein lipase (LPL), synthesized by adipocytes and myocytes, must be transported to the luminal endothelial cell surface where it then interacts with circulating lipoproteins. The first step in this extracellular LPL transport pathway is LPL release from the surface of LPL-synthesizing cells. Because hydrolysis of triglyceride (TG)-rich lipoproteins releases LPL from the apical surface of endothelial cells, we hypothesized that the same substances dissociate LPL from adipocytes. 125I-LPL was bound to the surface of brown adipocytes (BFC-1 beta). LPL binding to the adipocyte surface was greater than to endothelial cell surfaces. Using low concentrations of heparin, more LPL was released from endothelial cells than BFC-1 beta, suggesting that the affinity of LPL binding to the adipocytes was greater than LPL affinity for endothelial cells. Greater than 3-fold more LPL was released from the cell surface when very low density lipoproteins (VLDL) were added to culture medium containing 3% bovine serum albumin. LPL remaining on the cell surface decreased with VLDL addition. Endogenously produced LPL activity was also released from the cells by VLDL. Low and high density lipoproteins did not release 125I-LPL or LPL activity from the adipocytes. To assess whether lipolysis was necessary for LPL release, BFC-1 beta were incubated with TG-rich lipoproteins from a patient with apoCII deficiency. The apoCII-deficient lipoproteins did not release LPL unless an exogenous source of apoCII was added. Apolipoproteins E and Cs and high molar ratios of oleic acid:bovine serum albumin did not release surface-associated LPL. Lysolecithin (25 and 100 microM), but not lecithin, monoglycerides, or diglycerides, released adipocyte surface LPL. Because lysolecithin also released LPL during a 4 degrees C incubation, cellular metabolic functions are not required for LPL dissociation from the cells. Lysolecithin also inhibited LPL binding to endothelial cells; however, this effect was

  13. Global gene expression profiling of brown to white adipose tissue transformation in sheep reveals novel transcriptional components linked to adipose remodeling

    DEFF Research Database (Denmark)

    Basse, Astrid L.; Dixen, Karen; Yadav, Rachita;

    2015-01-01

    NR1H3, MYC, KLF4, ESR1, RELA and BCL6, which were linked to the overall changes in gene expression during the adipose tissue remodeling. Finally, the perirenal adipose tissue expressed both brown and brite/beige adipocyte marker genes at birth, the expression of which changed substantially over time...

  14. Ambient particulate air pollution induces oxidative stress and alterations of mitochondria and gene expression in brown and white adipose tissues

    Directory of Open Access Journals (Sweden)

    Harkema Jack R

    2011-07-01

    Full Text Available Abstract Background Prior studies have demonstrated a link between air pollution and metabolic diseases such as type II diabetes. Changes in adipose tissue and its mitochondrial content/function are closely associated with the development of insulin resistance and attendant metabolic complications. We investigated changes in adipose tissue structure and function in brown and white adipose depots in response to chronic ambient air pollutant exposure in a rodent model. Methods Male ApoE knockout (ApoE-/- mice inhaled concentrated fine ambient PM (PM 2.5 or filtered air (FA for 6 hours/day, 5 days/week, for 2 months. We examined superoxide production by dihydroethidium staining; inflammatory responses by immunohistochemistry; and changes in white and brown adipocyte-specific gene profiles by real-time PCR and mitochondria by transmission electron microscopy in response to PM2.5 exposure in different adipose depots of ApoE-/- mice to understand responses to chronic inhalational stimuli. Results Exposure to PM2.5 induced an increase in the production of reactive oxygen species (ROS in brown adipose depots. Additionally, exposure to PM2.5 decreased expression of uncoupling protein 1 in brown adipose tissue as measured by immunohistochemistry and Western blot. Mitochondrial number was significantly reduced in white (WAT and brown adipose tissues (BAT, while mitochondrial size was also reduced in BAT. In BAT, PM2.5 exposure down-regulated brown adipocyte-specific genes, while white adipocyte-specific genes were differentially up-regulated. Conclusions PM2.5 exposure triggers oxidative stress in BAT, and results in key alterations in mitochondrial gene expression and mitochondrial alterations that are pronounced in BAT. We postulate that exposure to PM2.5 may induce imbalance between white and brown adipose tissue functionality and thereby predispose to metabolic dysfunction.

  15. Brown and white adipose tissues: intrinsic differences in gene expression and response to cold exposure in mice.

    Science.gov (United States)

    Rosell, Meritxell; Kaforou, Myrsini; Frontini, Andrea; Okolo, Anthony; Chan, Yi-Wah; Nikolopoulou, Evanthia; Millership, Steven; Fenech, Matthew E; MacIntyre, David; Turner, Jeremy O; Moore, Jonathan D; Blackburn, Edith; Gullick, William J; Cinti, Saverio; Montana, Giovanni; Parker, Malcolm G; Christian, Mark

    2014-04-15

    Brown adipocytes dissipate energy, whereas white adipocytes are an energy storage site. We explored the plasticity of different white adipose tissue depots in acquiring a brown phenotype by cold exposure. By comparing cold-induced genes in white fat to those enriched in brown compared with white fat, at thermoneutrality we defined a "brite" transcription signature. We identified the genes, pathways, and promoter regulatory motifs associated with "browning," as these represent novel targets for understanding this process. For example, neuregulin 4 was more highly expressed in brown adipose tissue and upregulated in white fat upon cold exposure, and cell studies showed that it is a neurite outgrowth-promoting adipokine, indicative of a role in increasing adipose tissue innervation in response to cold. A cell culture system that allows us to reproduce the differential properties of the discrete adipose depots was developed to study depot-specific differences at an in vitro level. The key transcriptional events underpinning white adipose tissue to brown transition are important, as they represent an attractive proposition to overcome the detrimental effects associated with metabolic disorders, including obesity and type 2 diabetes.

  16. An ERβ agonist induces browning of subcutaneous abdominal fat pad in obese female mice.

    Science.gov (United States)

    Miao, Yi-Fei; Su, Wen; Dai, Yu-Bing; Wu, Wan-Fu; Huang, Bo; Barros, Rodrigo P A; Nguyen, Hao; Maneix, Laure; Guan, You-Fei; Warner, Margaret; Gustafsson, Jan-Åke

    2016-12-06

    Estrogen, via estrogen receptor alpha (ERα), exerts several beneficial effects on metabolism and energy homeostasis by controlling size, enzymatic activity and hormonal content of adipose tissue. The actions of estrogen on sympathetic ganglia, which are key players in the browning process, are less well known. In the present study we show that ERβ influences browning of subcutaneous adipose tissue (SAT) via its actions both on sympathetic ganglia and on the SAT itself. A 3-day-treatment with a selective ERβ agonist, LY3201, induced browning of SAT in 1-year-old obese WT and ERα(-/-) female mice. Browning was associated with increased expression of ERβ in the nuclei of neurons in the sympathetic ganglia, increase in tyrosine hydroxylase in both nerve terminals in the SAT and sympathetic ganglia neurons and an increase of β3-adrenoceptor in the SAT. LY3201 had no effect on browning in young female or male mice. In the case of young females browning was already maximal while in males there was very little expression of ERβ in the SAT and very little expression of the β3-adrenoceptor. The increase in both sympathetic tone and responsiveness of adipocytes to catecholamines reveals a novel role for ERβ in controlling browning of adipose tissue.

  17. Advances in molecular mechanisms of browning of white adipose tissue%白色脂肪组织棕色化调控机制的研究进展

    Institute of Scientific and Technical Information of China (English)

    倪鸣; 王金焱(综述); 王璟(审校)

    2015-01-01

    脂肪组织棕色细胞和白色细胞具有截然不同的代谢特征。白色脂肪细胞推动动脉粥样硬化的形成与发展,而棕色脂肪细胞在动脉粥样硬化的防治中发挥重要作用,两者可以相互转化。文中从转录因子(如PPARγ、PRDM16、PGC-1α)、共调节因子、激素、信号分子、氧化应激和miRNAs的调控等方面对白色脂肪组织棕色化调控机制作一综述。%Brown and white adipocytes have different metabolism characteristics.White adipocytes promote the formation and development of atherosclerosis.However, brown adipocytes contribute to the control of atherosclerosis.Brown and white adipocyte phe-notypes can transform mutually.This article will elaborate the pathogenesis of the transformation between brown/white adipocyte pheno-types regulated by transcription factors(such as PPARγ, PRDM16, PGC-1α), co-regulators, hormones, proteins, signal molecules, oxidative stress and miRNAs.

  18. Irradiated brown dwarfs

    CERN Document Server

    Casewell, S L; Lawrie, K A; Maxted, P F L; Dobbie, P D; Napiwotzki, R

    2014-01-01

    We have observed the post common envelope binary WD0137-349 in the near infrared $J$, $H$ and $K$ bands and have determined that the photometry varies on the system period (116 min). The amplitude of the variability increases with increasing wavelength, indicating that the brown dwarf in the system is likely being irradiated by its 16500 K white dwarf companion. The effect of the (primarily) UV irradiation on the brown dwarf atmosphere is unknown, but it is possible that stratospheric hazes are formed. It is also possible that the brown dwarf (an L-T transition object) itself is variable due to patchy cloud cover. Both these scenarios are discussed, and suggestions for further study are made.

  19. 10e12z CLA alters adipocyte differentiation and adipocyte cytokine expression and induces macrophage proliferation.

    Science.gov (United States)

    Belda, Benjamin J; Thompson, Jerry T; Eser, Pinar O; Vanden Heuvel, John P

    2012-05-01

    The trans-10, cis-12 (10e12z) conjugated linoleic acid (CLA) isomer of CLA is responsible for loss of lipid storage or adipose tissue in vitro or in vivo. This isomer also induces inflammatory signaling in both mouse and human adipocytes in vitro. However, when these events occur and whether they are significant enough to affect other cell types are unclear. In these experiments, the 3T3-L1 cell line has been used to examine the interaction between inflammatory signaling and decreased differentiation or lipid storage induced by 10e12z CLA. In assays measuring both lipid accumulation and gene expression, differentiating 3T3-L1 cells exhibit concurrent induction of inflammatory signaling, as measured by cyclooxygenase-2 expression, and a decrease in adipocyte marker gene expression. Furthermore, in fully differentiated adipocytes, as identified in microarray assays and confirmed with real-time polymerase chain reaction, 10e12z CLA also significantly affected expression of both matrix metalloprotein-3 (MMP-3), collagen VI α 3 ColVI alpha 3 (VIα3) and the cytokine epiregulin, demonstrating that the effects of 10e12z broadly impact adipocyte function. In agreement with other experimental systems, 10e12z CLA inhibited RAW 264.7 cell proliferation; however, in response to adipocyte-conditioned media, 10e12z-CLA-treated adipocytes induced proliferation of this cell line, suggesting that the effect of 10e12z CLA is context dependent. These results are largely consistent with the known activation of the inflammatory mediator nuclear factor-κB in adipocytes in vitro and in vivo by 10e12z CLA treatment and demonstrate that adipose is an important target tissue of this isomer that impacts other cell types.

  20. Microsomal Triglyceride Transfer Protein (MTP Associates with Cytosolic Lipid Droplets in 3T3-L1 Adipocytes.

    Directory of Open Access Journals (Sweden)

    Joseph D Love

    Full Text Available Lipid droplets are intracellular energy storage organelles composed of a hydrophobic core of neutral lipid, surrounded by a monolayer of phospholipid and a diverse array of proteins. The function of the vast majority of these proteins with regard to the formation and/or turnover of lipid droplets is unknown. Our laboratory was the first to report that microsomal triglyceride transfer protein (MTP, a lipid transfer protein essential for the assembly of triglyceride-rich lipoproteins, was expressed in adipose tissue of humans and mice. In addition, our studies suggested that MTP was associated with lipid droplets in both brown and white fat. Our observations led us to hypothesize that MTP plays a key role in lipid droplet formation and/or turnover. The objective of these studies was to gain insight into the function of MTP in adipocytes. Using molecular, biochemical, and morphologic approaches we have shown: 1 MTP protein levels increase nearly five-fold as 3T3-L1 cells differentiate into adipocytes. 2 As 3T3-L1 cells undergo differentiation, MTP moves from the juxtanuclear region of the cell to the surface of lipid droplets. MTP and perilipin 2, a major lipid droplet surface protein, are found on the same droplets; however, MTP does not co-localize with perilipin 2. 3 Inhibition of MTP activity has no effect on the movement of triglyceride out of the cell either as a lipid complex or via lipolysis. 4 MTP is found associated with lipid droplets within hepatocytes from human fatty livers, suggesting that association of MTP with lipid droplets is not restricted to adipocytes. In summary, our data demonstrate that MTP is a lipid droplet-associated protein. Its location on the surface of the droplet in adipocytes and hepatocytes, coupled with its known function as a lipid transfer protein and its increased expression during adipocyte differentiation suggest a role in lipid droplet biology.

  1. Brown fat like gene expression in the epicardial fat depot correlates with circulating HDL-cholesterol and triglycerides in patients with coronary artery disease.

    Science.gov (United States)

    Chechi, Kanta; Blanchard, Pierre-Gilles; Mathieu, Patrick; Deshaies, Yves; Richard, Denis

    2013-09-01

    Recent evidence indicates that epicardial adipose tissue (EAT) expresses uncoupling protein-1 (UCP1), a marker of brown adipocytes. However, the putative effects of the presence of brown adipocytes in EAT remain unknown. The mRNA expression of genes related to brown adipocyte-mediated thermogenesis was measured in the fat samples collected from the epicardial-, mediastinal- and subcutaneous-depots of patients undergoing coronary artery bypass grafting. Both univariate and multivariate analyses were then utilized to determine any association between gene expression and the anthropometrics and fasting blood chemistries of these patients. EAT exhibited significantly higher expression of UCP1 and cytochrome c oxidase subunit-IV (COX-IV) compared to mediastinal- and subcutaneous-fat depots (P ≤ 0.05). EAT expression of UCP1 (r=0.50), COX-IV (r=0.37) and lipoprotein lipase (LPL) (r=0.58) positively associated with circulating levels of HDL-cholesterol (P ≤ 0.05). In addition, EAT expression of LPL, acyl coA dehydrogenase-short, -medium and -long chain genes associated negatively with circulating TG levels (P ≤ 0.05). Abundance of UCP-1 in the EAT relative to other fat depots confirms the presence of brown adipocytes in human EAT. Furthermore, the correlations among the EAT expression of thermogenesis-related genes with the circulating HDL and TG levels indicate that presence of active brown adipocytes shares a functional association with the circulating plasma lipids in humans. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  2. Transcriptional regulatory program in wild-type and retinoblastoma gene-deficient mouse embryonic fibroblasts during adipocyte differentiation

    DEFF Research Database (Denmark)

    Hakim-Weber, Robab; Krogsdam, Anne-M; Jørgensen, Claus

    2011-01-01

    Although many molecular regulators of adipogenesis have been identified a comprehensive catalogue of components is still missing. Recent studies showed that the retinoblastoma protein (pRb) was expressed in the cell cycle and late cellular differentiation phase during adipogenesis. To investigate...... of 64 deregulated genes showed that the Rb-/- MEF model exhibits a brown(-like) adipocyte phenotype. Additionally, the analysis results indicate a different or additional role for pRb family member involvement in the lineage commitment. CONCLUSION: In this study a number of commonly modulated genes...

  3. Superantigen activates the gp130 receptor on adipocytes resulting in altered adipocyte metabolism.

    Science.gov (United States)

    Banke, Elin; Rödström, Karin; Ekelund, Mikael; Dalla-Riva, Jonathan; Lagerstedt, Jens O; Nilsson, Staffan; Degerman, Eva; Lindkvist-Petersson, Karin; Nilson, Bo

    2014-06-01

    The bacteria Staphylococcus aureus is part of the normal bacterial flora and produces a repertoire of enterotoxins which can cause food poisoning and toxic shock and might contribute to the pathogenesis of inflammatory diseases. These enterotoxins directly cross-link the T cell receptor with MHC class II, activating large amounts of T cells and are therefore called superantigens. It was recently discovered that the superantigen SEA binds to the cytokine receptor gp130. As obesity and type 2 diabetes are highly associated with inflammation of the adipose tissue and gp130 has been shown to play an important role in adipocytes, we wanted to investigate the effect of SEA on adipocyte signaling and function. Binding of SEA to gp130 was examined using surface plasmon resonance in a cell free system. Effects of SEA on adipocyte signaling, insulin sensitivity and function were studied using western blotting and biological assays for lipolysis, lipogenesis and glucose uptake. We demonstrate that SEA binds to gp130 with a medium affinity. Furthermore, SEA induces phosphorylation of a key downstream target, STAT3, in adipocytes. SEA also inhibits insulin-induced activation of PKB and PKB downstream signaling which was associated with reduced basal and insulin induced glucose uptake, reduced lipogenesis as well as reduced ability of insulin to inhibit lipolysis. SEA inhibits insulin signaling as well as insulin biological responses in adipocytes supporting that bacterial infection might contribute to the development of insulin resistance and type 2 diabetes. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Optical detection of pores in adipocyte membrane

    Science.gov (United States)

    Yanina, I. Yu.; Doubrovski, V. A.; Tuchin, V. V.

    2013-08-01

    Structures that can be interpreted as cytoplasm droplets leaking through the membrane are experimentally detected on the membranes of adipocytes using optical digital microscopy. The effect of an aqueous alcohol solution of brilliant green on the amount and sizes of structures is studied. It is demonstrated that the optical irradiation of the adipocytes that are sensitized with the aid of the brilliant green leads to an increase in the amount of structures (pores) after the irradiation. The experimental results confirm the existence of an earlier-proposed effect of photochemical action on the sensitized cells of adipose tissue that involves additional formation of pores in the membrane of the sensitized cell under selective optical irradiation. The proposed method for the detection of micropores in the membrane of adipose tissue based on the detection of the cytoplasm droplets leaking from the cell can be considered as a method for the optical detection of nanosized pores.

  5. Hypoxia induces apelin expression in human adipocytes.

    Science.gov (United States)

    Geiger, K; Muendlein, A; Stark, N; Saely, C H; Wabitsch, M; Fraunberger, P; Drexel, H

    2011-06-01

    Adipokines play a central role in the development of diseases associated with insulin resistance and obesity. Hypoxia in adipose tissue leads to a dysregulation of the expression of adipokines. The effect of hypoxia on the more recently identified adipokine apelin in human adipocytes is unclear. Therefore, we aimed at investigating the role of hypoxia on the expression of the adipokine apelin. Differentiated human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes were cultured under hypoxic conditions for varying time periods. A modular incubator chamber was used to create a hypoxic tissue culture environment (defined as 1% O(2), 94% N, and 5% CO(2)). In addition, hypoxic conditions were mimicked by using CoCl(2). The effect of hypoxia on the expression of the investigated adipokines was measured by real-time PCR and the secretion of apelin was quantified by ELISA. Induction of hypoxia significantly induced mRNA expression of leptin and apelin in differentiated SGBS adipocytes compared with the normoxic control condition. Expression of adiponectin was significantly decreased by hypoxia. In addition, the amount of secreted apelin protein in response to hypoxia was elevated compared to untreated cells. Furthermore, we could demonstrate that the observed hypoxia-induced induction of apelin mRNA expression is in the first phase dependent on HIF-1α. In our study, we could demonstrate for the first time that apelin expression and secretion by human adipocytes are strongly induced under hypoxic conditions and that the early response on hypoxia with apelin induction is dependent on HIF-1α. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Fucoidans from brown seaweeds

    DEFF Research Database (Denmark)

    Ale, Marcel Tutor; Meyer, Anne S.

    2013-01-01

    Fucoidan or fucoidans cover a family of sulfated fucose-rich polysaccharides, built of a backbone of L-fucose units, and characteristically found in brown seaweeds. Fucoidans have potential therapeutic properties, including anti-inflammatory and anti-coagulant activities, as well as anti...

  7. Protein carbonylation and adipocyte mitochondrial function.

    Science.gov (United States)

    Curtis, Jessica M; Hahn, Wendy S; Stone, Matthew D; Inda, Jacob J; Droullard, David J; Kuzmicic, Jovan P; Donoghue, Margaret A; Long, Eric K; Armien, Anibal G; Lavandero, Sergio; Arriaga, Edgar; Griffin, Timothy J; Bernlohr, David A

    2012-09-21

    Carbonylation is the covalent, non-reversible modification of the side chains of cysteine, histidine, and lysine residues by lipid peroxidation end products such as 4-hydroxy- and 4-oxononenal. In adipose tissue the effects of such modifications are associated with increased oxidative stress and metabolic dysregulation centered on mitochondrial energy metabolism. To address the role of protein carbonylation in the pathogenesis of mitochondrial dysfunction, quantitative proteomics was employed to identify specific targets of carbonylation in GSTA4-silenced or overexpressing 3T3-L1 adipocytes. GSTA4-silenced adipocytes displayed elevated carbonylation of several key mitochondrial proteins including the phosphate carrier protein, NADH dehydrogenase 1α subcomplexes 2 and 3, translocase of inner mitochondrial membrane 50, and valyl-tRNA synthetase. Elevated protein carbonylation is accompanied by diminished complex I activity, impaired respiration, increased superoxide production, and a reduction in membrane potential without changes in mitochondrial number, area, or density. Silencing of the phosphate carrier or NADH dehydrogenase 1α subcomplexes 2 or 3 in 3T3-L1 cells results in decreased basal and maximal respiration. These results suggest that protein carbonylation plays a major instigating role in cytokine-dependent mitochondrial dysfunction and may be linked to the development of insulin resistance in the adipocyte.

  8. Bacterial translocation - impact on the adipocyte compartment.

    Science.gov (United States)

    Kruis, Tassilo; Batra, Arvind; Siegmund, Britta

    2014-01-01

    Over the last decade it became broadly recognized that adipokines and thus the fat tissue compartment exert a regulatory function on the immune system. Our own group described the pro-inflammatory function of the adipokine leptin within intestinal inflammation in a variety of animal models. Following-up on this initial work, the aim was to reveal stimuli and mechanisms involved in the activation of the fat tissue compartment and the subsequent release of adipokines and other mediators paralleled by the infiltration of immune cells. This review will summarize the current literature on the possible role of the mesenteric fat tissue in intestinal inflammation with a focus on Crohn's disease (CD). CD is of particular interest in this context since the transmural intestinal inflammation has been associated with a characteristic hypertrophy of the mesenteric fat, a phenomenon called "creeping fat." The review will address three consecutive questions: (i) What is inducing adipocyte activation, (ii) which factors are released after activation and what are the consequences for the local fat tissue compartment and infiltrating cells; (iii) do the answers generated before allow for an explanation of the role of the mesenteric fat tissue within intestinal inflammation? With this review we will provide a working model indicating a close interaction in between bacterial translocation, activation of the adipocytes, and subsequent direction of the infiltrating immune cells. In summary, the models system mesenteric fat indicates a unique way how adipocytes can directly interact with the immune system.

  9. Notch pathway is dispensable for adipocyte specification.

    Science.gov (United States)

    Nichols, Amy M; Pan, Yonghua; Herreman, An; Hadland, Brandon K; De Strooper, Bart; Kopan, Raphael; Huppert, Stacey S

    2004-09-01

    In the past decade we have witnessed an epidemic of obesity in developed countries. Therefore, understanding the mechanisms involved in regulation of body weight is becoming an increasingly important goal shared by the public and the scientific community. The key to fat deposition is the adipocyte, a specialized cell that plays a critical role in energy balance and appetite regulation. Much of our knowledge of adipogenesis comes from studies using preadipocytic cell lines that have provided important information regarding molecular control of adipocyte differentiation. However, they fall short of revealing how naive cells acquire competence for adipogenesis. Studies in preadipocytes indicate that the Notch pathway plays a role in regulating adipogenesis (Garces et al.: J Biol Chem 272:29729-29734, 1997). Given the known biological functions of Notch in mediating cell fate decisions (Artavanis-Tsakonas et al.: Science 284:770-776, 1999), we wished to test the hypothesis that the Notch pathway is required for this cellular program by examining adipogenesis in several genetic loss-of-function models that encompass the entire pathway. We conclude that the "canonical" Notch signaling pathway is dispensable for adipocyte specification and differentiation from either mesenchymal or epithelial progenitors.

  10. Intradermal adipocytes mediate fibroblast recruitment during skin wound healing

    Science.gov (United States)

    Schmidt, Barbara A.; Horsley, Valerie

    2013-01-01

    Acute wound healing in the skin involves the communication of multiple cell types to coordinate keratinocyte and fibroblast proliferation and migration for epidermal and dermal repair. Many studies have focused on the interplay between hematopoietic cells, keratinocytes and fibroblasts during skin wound healing, yet the possible roles for other cell types within the skin, such as intradermal adipocytes, have not been investigated during this process. Here, we identify that adipocyte lineage cells are activated and function during acute skin wound healing. We find that adipocyte precursor cells proliferate and mature adipocytes repopulate skin wounds following inflammation and in parallel with fibroblast migration. Functional analysis of mice with defects in adipogenesis demonstrates that adipocytes are necessary for fibroblast recruitment and dermal reconstruction. These data implicate adipocytes as a key component of the intercellular communication that mediates fibroblast function during skin wound healing. PMID:23482487

  11. Cadmium modulates adipocyte functions in metallothionein-null mice

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Takashige; Nishiyama, Kaori; Kadota, Yoshito; Sato, Masao; Inoue, Masahisa; Suzuki, Shinya, E-mail: suzukis@ph.bunri-u.ac.jp

    2013-11-01

    Our previous study has demonstrated that exposure to cadmium (Cd), a toxic heavy metal, causes a reduction of adipocyte size and the modulation of adipokine expression. To further investigate the significance of the Cd action, we studied the effect of Cd on the white adipose tissue (WAT) of metallothionein null (MT{sup −/−}) mice, which cannot form atoxic Cd–MT complexes and are used for evaluating Cd as free ions, and wild type (MT{sup +/+}) mice. Cd administration more significantly reduced the adipocyte size of MT{sup −/−} mice than that of MT{sup +/+} mice. Cd exposure also induced macrophage recruitment to WAT with an increase in the expression level of Ccl2 (MCP-1) in the MT{sup −/−} mice. The in vitro exposure of Cd to adipocytes induce triglyceride release into culture medium, decrease in the expression levels of genes involved in fatty acid synthesis and lipid hydrolysis at 24 h, and at 48 h increase in phosphorylation of the lipid-droplet-associated protein perilipin, which facilitates the degradation of stored lipids in adipocytes. Therefore, the reduction in adipocyte size by Cd may arise from an imbalance between lipid synthesis and lipolysis. In addition, the expression levels of leptin, adiponectin and resistin decreased in adipocytes. Taken together, exposure to Cd may induce unusually small adipocytes and modulate the expression of adipokines differently from the case of physiologically small adipocytes, and may accelerate the risk of developing insulin resistance and type 2 diabetes. - Highlights: • Cd causes a marked reduction in adipocyte size in MT-null mice. • Cd enhances macrophage migration into adipose tissue and disrupt adipokine secretion. • MT gene alleviates Cd-induced adipocyte dysfunctions. • Cd enhances the degradation of stored lipids in adipocytes, mediated by perilipin. • Cd induces unusually small adipocytes and the abnormal expression of adipokines.

  12. Dedifferentiated adipocyte-derived progeny cells (DFAT cells)

    OpenAIRE

    Wei, Shengjuan; Zan, Linsen; Hausman, Gary J.; Rasmussen, Theodore P; Bergen, Werner G.; Dodson, Michael V.

    2013-01-01

    Analyses of mature adipocytes have shown that they possess a reprogramming ability in vitro, which is associated with dedifferentiation. The subsequent dedifferentiated fat cells (DFAT cells) are multipotent and can differentiate into adipocytes and other cell types as well. Mature adipocytes can be easily obtained by biopsy, and the cloned progeny cells are homogeneous in vitro. Therefore, DFAT cells (a new type of stem cell) may provide an excellent source of cells for tissue regeneration, ...

  13. The Ubiquitin Ligase Siah2 Regulates PPARγ Activity in Adipocytes

    OpenAIRE

    Kilroy, Gail; Kirk-Ballard, Heather; Carter, Lauren E.; Floyd, Z. Elizabeth

    2012-01-01

    Moderate reductions in peroxisome proliferator-activated receptor (PPAR)γ levels control insulin sensitivity as effectively as activation of PPARγ in adipocytes by the thiazolidinediones. That observation suggests that PPARγ activity can be regulated by modulating the amount of PPARγ protein in adipocytes. Activation of PPARγ in adipocytes is linked to changes in PPARγ protein levels via increased degradation of PPARγ proteins by the ubiquitin proteasome system. Identification of the ubiquiti...

  14. PI3K/Akt is involved in brown adipogenesis mediated by growth differentiation factor-5 in association with activation of the Smad pathway

    Energy Technology Data Exchange (ETDEWEB)

    Hinoi, Eiichi; Iezaki, Takashi; Fujita, Hiroyuki; Watanabe, Takumi; Odaka, Yoshiaki; Ozaki, Kakeru; Yoneda, Yukio, E-mail: yyoneda@p.kanazawa-u.ac.jp

    2014-07-18

    Highlights: • Akt is preferentially phosphorylated in BAT and sWAT of aP2-GDF5 mice. • PI3K/Akt signaling is involved in GDF5-induced brown adipogenesis. • PI3K/Akt signaling regulates GDF5-induced Smad5 phosphorylation. - Abstract: We have previously demonstrated promotion by growth differentiation factor-5 (GDF5) of brown adipogenesis for systemic energy expenditure through a mechanism relevant to activating the bone morphological protein (BMP) receptor/mothers against decapentaplegic homolog (Smad)/peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) pathway. Here, we show the involvement of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in brown adipogenesis mediated by GDF5. Overexpression of GDF5 in cells expressing adipocyte protein-2 markedly accelerated the phosphorylation of Smad1/5/8 and Akt in white and brown adipose tissues. In brown adipose tissue from heterozygous GDF5{sup Rgsc451} mutant mice expressing a dominant-negative (DN) GDF5 under obesogenic conditions, the basal phosphorylation of Smad1/5/8 and Akt was significantly attenuated. Exposure to GDF5 not only promoted the phosphorylation of both Smad1/5/8 and Akt in cultured brown pre-adipocytes, but also up-regulated Pgc1a and uncoupling protein-1 expression in a manner sensitive to the PI3K/Akt inhibitor Ly294002 as well as retroviral infection with DN-Akt. GDF5 drastically promoted BMP-responsive luciferase reporter activity in a Ly294002-sensitive fashion. Both Ly294002 and DN-Akt markedly inhibited phosphorylation of Smad5 in the nuclei of brown pre-adipocytes. These results suggest that PI3K/Akt signals play a role in the GDF5-mediated brown adipogenesis through a mechanism related to activation of the Smad pathway.

  15. The cold-induced lipokine 12,13-diHOME promotes fatty acid transport into brown adipose tissue

    DEFF Research Database (Denmark)

    Lynes, Matthew D; Leiria, Luiz O; Lundh, Morten

    2017-01-01

    . Mechanistically, 12,13-diHOME increased fatty acid (FA) uptake into brown adipocytes by promoting the translocation of the FA transporters FATP1 and CD36 to the cell membrane. These data suggest that 12,13-diHOME, or a functional analog, could be developed as a treatment for metabolic disorders.......Brown adipose tissue (BAT) and beige adipose tissue combust fuels for heat production in adult humans, and so constitute an appealing target for the treatment of metabolic disorders such as obesity, diabetes and hyperlipidemia. Cold exposure can enhance energy expenditure by activating BAT...

  16. Blockade of the activin receptor IIb activates functional brown adipogenesis and thermogenesis by inducing mitochondrial oxidative metabolism.

    Science.gov (United States)

    Fournier, Brigitte; Murray, Ben; Gutzwiller, Sabine; Marcaletti, Stefan; Marcellin, David; Bergling, Sebastian; Brachat, Sophie; Persohn, Elke; Pierrel, Eliane; Bombard, Florian; Hatakeyama, Shinji; Trendelenburg, Anne-Ulrike; Morvan, Frederic; Richardson, Brian; Glass, David J; Lach-Trifilieff, Estelle; Feige, Jerome N

    2012-07-01

    Brown adipose tissue (BAT) is a key tissue for energy expenditure via fat and glucose oxidation for thermogenesis. In this study, we demonstrate that the myostatin/activin receptor IIB (ActRIIB) pathway, which serves as an important negative regulator of muscle growth, is also a negative regulator of brown adipocyte differentiation. In parallel to the anticipated hypertrophy of skeletal muscle, the pharmacological inhibition of ActRIIB in mice, using a neutralizing antibody, increases the amount of BAT without directly affecting white adipose tissue. Mechanistically, inhibition of ActRIIB inhibits Smad3 signaling and activates the expression of myoglobin and PGC-1 coregulators in brown adipocytes. Consequently, ActRIIB blockade in brown adipose tissue enhances mitochondrial function and uncoupled respiration, translating into beneficial functional consequences, including enhanced cold tolerance and increased energy expenditure. Importantly, ActRIIB inhibition enhanced energy expenditure only at ambient temperature or in the cold and not at thermoneutrality, where nonshivering thermogenesis is minimal, strongly suggesting that brown fat activation plays a prominent role in the metabolic actions of ActRIIB inhibition.

  17. The formation of brown adipose tissue induced by transgenic over-expression of PPARγ2.

    Science.gov (United States)

    Zhou, Ying; Yang, Jinzeng; Huang, Jinliang; Li, Ting; Xu, Dequan; Zuo, Bo; Hou, Liming; Wu, Wangjun; Zhang, Lin; Xia, Xiaoliang; Ma, Zhiyuan; Ren, Zhuqing; Xiong, Yuanzhu

    2014-04-18

    Brown adipose tissue (BAT) is specialized to dissipate energy as heat, therefore reducing fat deposition and counteracting obesity. Brown adipocytes arise from myoblastic progenitors during embryonic development by the action of transcription regulator PRDM16 binding to PPARγ, which promotes BAT-like phenotype in white adipose tissue. To investigate the capability of converting white adipose tissue to BAT or browning by PPARγ in vivo, we generated transgenic mice with over-expressed PPARγ2. The transgenic mice showed strong brown fat features in subcutaneous fat in morphology and histology. To provide molecular evidences on browning characteristics of the adipose tissue, we employed quantitative real-time PCR to determine BAT-specific gene expressions. The transgenic mice had remarkably elevated mRNA level of UCP1, Elovl3, PGC1α and Cebpα in subcutaneous fat. Compared with wild-type mice, UCP1 protein levels were increased significantly in transgenic mice. ATP concentration was slightly decreased in the subcutaneous fat of transgenic mice. Western blotting analysis also confirmed that phosphorylated AMPK and ACC proteins were significantly (P<0.01) increased in the transgenic mice. Therefore, this study demonstrated that over-expression of PPARγ2 in skeletal muscle can promote conversion of subcutaneous fat to brown fat formation, which can have beneficial effects on increasing energy metabolisms and combating obesity.

  18. M1-M2 balancing act in white adipose tissue browning – a new role for RIP140

    OpenAIRE

    Liu, Pu-Ste; LIN, YI-WEI; Burton, Frank H; Wei, Li-Na

    2015-01-01

    A “Holy Grail” sought in medical treatment of obesity is to be able to biologically reprogram their adipose tissues to burn fat rather than store it. White adipose tissue (WAT) stores fuel and its expansion underlines insulin resistance (IR) whereas brown adipose tissue (BAT) burns fuel and stimulates insulin sensitivity. These two types of fats seesaw within our bodies via a regulatory mechanism that involves intricate communication between adipocytes and blood cells, particularly macrophage...

  19. Invited review: Pre- and postnatal adipose tissue development in farm animals: from stem cells to adipocyte physiology.

    Science.gov (United States)

    Louveau, I; Perruchot, M-H; Bonnet, M; Gondret, F

    2016-11-01

    Both white and brown adipose tissues are recognized to be differently involved in energy metabolism and are also able to secrete a variety of factors called adipokines that are involved in a wide range of physiological and metabolic functions. Brown adipose tissue is predominant around birth, except in pigs. Irrespective of species, white adipose tissue has a large capacity to expand postnatally and is able to adapt to a variety of factors. The aim of this review is to update the cellular and molecular mechanisms associated with pre- and postnatal adipose tissue development with a special focus on pigs and ruminants. In contrast to other tissues, the embryonic origin of adipose cells remains the subject of debate. Adipose cells arise from the recruitment of specific multipotent stem cells/progenitors named adipose tissue-derived stromal cells. Recent studies have highlighted the existence of a variety of those cells being able to differentiate into white, brown or brown-like/beige adipocytes. After commitment to the adipocyte lineage, progenitors undergo large changes in the expression of many genes involved in cell cycle arrest, lipid accumulation and secretory functions. Early nutrition can affect these processes during fetal and perinatal periods and can also influence or pre-determinate later growth of adipose tissue. How these changes may be related to adipose tissue functional maturity around birth and can influence newborn survival is discussed. Altogether, a better knowledge of fetal and postnatal adipose tissue development is important for various aspects of animal production, including neonatal survival, postnatal growth efficiency and health.

  20. All-trans retinoic acid increases oxidative metabolism in mature adipocytes

    DEFF Research Database (Denmark)

    Mercader, Josep; Madsen, Lise; Felipe, Francisco;

    2007-01-01

    BACKGROUND/AIMS: In rodents, retinoic acid (RA) treatment favors loss of body fat mass and the acquisition of brown fat features in white fat depots. In this work, we sought to examine to what extent these RA effects are cell autonomous or dependent on systemic factors. METHODS: Parameters of lipid...... metabolism and related gene expression were analyzed in differentiated 3T3-L1 adipocytes after exposure to RA or vehicle. RESULTS: Treatment with RA resulted in decreased cellular triacylglycerol content and increased basal lipolysis and fatty acid oxidation rate. At the mRNA level, RA treatment led......), and to an increased expression of proteins favoring fat oxidation (peroxisome proliferator-activated receptor gamma coactivator-1alpha, uncoupling protein 2, fasting-induced adipose factor, enzymes of mitochondrial fatty acid oxidation). These changes paralleled inactivation of the retinoblastoma protein and were...

  1. Cold-Induced Browning Dynamically Alters the Expression Profiles of Inflammatory Adipokines with Tissue Specificity in Mice

    Directory of Open Access Journals (Sweden)

    Xiao Luo

    2016-05-01

    Full Text Available Cold exposure or β3-adrenoceptor agonist treatment induces the adipose tissues remodeling, relevant for beige adipogenesis within white adipose tissue (WAT. It remains unclear whether this process influences inflammatory adipokines expression in adipose tissues. We determine the temporal profile of cold or β3-adrenoceptor agonist (CL316,243-induced changes in the expression of inflammatory adipokines in adipose tissues in mice or primary mice adipocytes. Male C57BL/6J mice at eight weeks old were exposed to 4 °C for 1–5 days. Interscapular brown adipose tissue (iBAT, inguinal subcutaneous WAT (sWAT and epididymal WAT (eWAT were harvested for gene and protein expression analysis. In addition, cultured primary mice brown adipocyte (BA and white adipocyte (WA treated with or without CL316,243 were harvested for gene expression analysis. The inflammatory adipokines expressed significantly higher in WAT than BAT at baseline. They were rapidly changed in iBAT, while down-regulated in sWAT and up-regulated in eWAT during the cold acclimation. Upon CL316,243 treatment, detected inflammatory adipokines except Leptin were transiently increased in both BA and WA. Our in vivo and in vitro data demonstrate that the browning process alters the inflammatory adipokines expression in adipose tissues, which is acutely responded to in iBAT, dynamically decreased in sWAT whilst increased in eWAT for compensation.

  2. ApoA-IV improves insulin sensitivity and glucose uptake in mouse adipocytes via PI3K-Akt Signaling

    Science.gov (United States)

    Li, Xiaoming; Wang, Fei; Xu, Min; Howles, Philip; Tso, Patrick

    2017-01-01

    Insulin resistance is a risk factor for type 2 diabetes mellitus. We investigated the effect of ApoA-IV on glucose uptake in the adipose and muscle tissues of mice and cultured 3T3-L1 adipocytes. We found that treatment with ApoA-IV lowered fasting blood glucose in both WT and diabetic KKAy mice by increasing glucose uptake in cardiac muscle, white adipose tissue, and brown adipose tissue through a mechanism that was partially insulin independent. Cell culture experiments showed that ApoA-IV improved glucose uptake in adipocytes in the absence of insulin by upregulating GLUT4 translocation by PI3K mediated activation of Akt signaling pathways. Considering our previous finding that ApoA-IV treatment enhanced pancreatic insulin secretion, these results suggests that ApoA-IV acts directly upon adipose tissue to improve glucose uptake and indirectly via insulin signaling. Our findings warrant future studies to identify the receptor for ApoA-IV and the downstream targets of PI3K-Akt signaling that regulate glucose uptake in adipocytes as potential therapeutic targets for treating insulin resistance. PMID:28117404

  3. DNA microarray analysis of genes differentially expressed in adipocyte differentiation

    Indian Academy of Sciences (India)

    Chunyan Yin; Yanfeng Xiao; Wei Zhang; Erdi Xu; Weihua Liu; Xiaoqing Yi; Ming Chang

    2014-06-01

    In the present study, the human liposarcoma cell line SW872 was used to identify global changes in gene expression profiles occurring during adipogenesis. We further explored some of the genes expressed during the late phase of adipocyte differentiation. These genes may play a major role in promoting excessive proliferation and accumulation of lipid droplets, which contribute to the development of obesity. By using microarray-based technology, we examined differential gene expression in early differentiated adipocytes and late differentiated adipocytes. Validated genes exhibited a ≥ 10-fold increase in the late phase of adipocyte differentiation by polymerase chain reaction (RT-PCR). Compared with undifferentiated preadipocytes, we found that 763 genes were increased in early differentiated adipocytes, and 667 genes were increased in later differentiated adipocytes. Furthermore, 21 genes were found being expressed 10-fold higher in the late phase of adipocyte differentiation. The results were in accordance with the RT-PCR test, which validated 11 genes, namely, CIDEC, PID1, LYRM1, ADD1, PPAR2, ANGPTL4, ADIPOQ, ACOX1, FIP1L1, MAP3K2 and PEX14. Most of these genes were found being expressed in the later phase of adipocyte differentiation involved in obesity-related diseases. The findings may help to better understand the mechanism of obesity and related diseases.

  4. Phytochemicals and regulation of the adipocyte life cycle.

    Science.gov (United States)

    Rayalam, Srujana; Della-Fera, Mary Anne; Baile, Clifton A

    2008-11-01

    Natural products have potential for inducing apoptosis, inhibiting adipogenesis and stimulating lipolysis in adipocytes. The objective of this review is to discuss the adipocyte life cycle and various dietary bioactives that target different stages of adipocyte life cycle. Different stages of adipocyte development include preadipocytes, maturing preadipocytes and mature adipocytes. Various dietary bioactives like genistein, conjugated linoleic acid (CLA), docosahexaenoic acid, epigallocatechin gallate, quercetin, resveratrol and ajoene affect adipocytes during specific stages of development, resulting in either inhibition of adipogenesis or induction of apoptosis. Although numerous molecular targets that can be used for both treatment and prevention of obesity have been identified, targeted monotherapy has resulted in lack of success. Thus, targeting several signal transduction pathways simultaneously with multiple natural products to achieve additive or synergistic effects might be an appropriate approach to address obesity. We have previously reported two such combinations, namely, ajoene+CLA and vitamin D+genistein. CLA enhanced ajoene-induced apoptosis in mature 3T3-L1 adipocytes by synergistically increasing the expression of several proapoptotic factors. Similarly, genistein potentiated vitamin D's inhibition of adipogenesis and induction of apoptosis in maturing preadipocytes by an enhanced expression of VDR (vitamin D receptor) protein. These two examples indicate that combination therapy employing compounds that target different stages of the adipocyte life cycle might prove beneficial for decreasing adipose tissue volume by inducing apoptosis or by inhibiting adipogenesis or both.

  5. Notch intracellular domain overexpression in adipocytes confers lipodystrophy in mice

    Directory of Open Access Journals (Sweden)

    Dionysios V. Chartoumpekis

    2015-07-01

    Conclusions: Increased Notch signaling in adipocytes in mice results in blocked expansion of white adipose tissue which leads to ectopic accumulation of lipids and insulin resistance, thus to a lipodystrophic phenotype. These results suggest that further investigation of the role of Notch signaling in adipocytes could lead to the manipulation of this pathway for therapeutic interventions in metabolic disease.

  6. DNA microarray analysis of genes differentially expressed in adipocyte differentiation.

    Science.gov (United States)

    Yin, Chunyan; Xiao, Yanfeng; Zhang, Wei; Xu, Erdi; Liu, Weihua; Yi, Xiaoqing; Chang, Ming

    2014-06-01

    In the present study, the human liposarcoma cell line SW872 was used to identify global changes in gene expression profiles occurring during adipogenesis. We further explored some of the genes expressed during the late phase of adipocyte differentiation. These genes may play a major role in promoting excessive proliferation and accumulation of lipid droplets, which contribute to the development of obesity. By using microarray-based technology, we examined differential gene expression in early differentiated adipocytes and late differentiated adipocytes. Validated genes exhibited a greater than or equal to 10-fold increase in the late phase of adipocyte differentiation by polymerase chain reaction (RT-PCR). Compared with undifferentiated preadipocytes, we found that 763 genes were increased in early differentiated adipocytes, and 667 genes were increased in later differentiated adipocytes. Furthermore, 21 genes were found being expressed 10-fold higher in the late phase of adipocyte differentiation. The results were in accordance with the RTPCR test, which validated 11 genes, namely, CIDEC, PID1, LYRM1, ADD1, PPAR?2, ANGPTL4, ADIPOQ, ACOX1, FIP1L1, MAP3K2 and PEX14. Most of these genes were found being expressed in the later phase of adipocyte differentiation involved in obesity-related diseases. The findings may help to better understand the mechanism of obesity and related diseases.

  7. Lsd1 Ablation Triggers Metabolic Reprogramming of Brown Adipose Tissue

    Directory of Open Access Journals (Sweden)

    Delphine Duteil

    2016-10-01

    Full Text Available Previous work indicated that lysine-specific demethylase 1 (Lsd1 can positively regulate the oxidative and thermogenic capacities of white and beige adipocytes. Here we investigate the role of Lsd1 in brown adipose tissue (BAT and find that BAT-selective Lsd1 ablation induces a shift from oxidative to glycolytic metabolism. This shift is associated with downregulation of BAT-specific and upregulation of white adipose tissue (WAT-selective gene expression. This results in the accumulation of di- and triacylglycerides and culminates in a profound whitening of BAT in aged Lsd1-deficient mice. Further studies show that Lsd1 maintains BAT properties via a dual role. It activates BAT-selective gene expression in concert with the transcription factor Nrf1 and represses WAT-selective genes through recruitment of the CoREST complex. In conclusion, our data uncover Lsd1 as a key regulator of gene expression and metabolic function in BAT.

  8. Data on regulation of the gene for the adipocyte-enriched micropeptide Adig/Smaf1 by qPCR analysis and luciferase reporter assay

    Directory of Open Access Journals (Sweden)

    Gang Ren

    2016-12-01

    Full Text Available This article describes qPCR analysis for the Adig/Smaf1 gene in multiple in vitro adipocyte differentiation models including white and brown adipogenesis, cell lines and primary cultures. The article also contains qPCR data for transcript levels of Adig/Smaf1 in a wide panel of murine tissues. Expression of Adig/Smaf1 transcript in white and brown adipose tissue in fasted and refed mice is reported and also data for Adig/Smaf1 transcript expression in genetically obese ob/ob mice. Data on the effects of siRNA-mediated knockdown of Srebp1c on Adig/Smaf1 transcript levels in 3T3-L1 adipocytes are shown. Luciferase reporter assays provide data for regulation of an ~ 2 kb fragment of the 5′ flanking region of Adig/Smaf1 gene by PPARγ/RXRα. This data is related to a research article describing Adig/Smaf1 protein expression, “Expression, regulation and functional assessment of the 80 amino acid Small Adipocyte Factor 1 (Smaf1 protein in adipocytes” (G. Ren, P. Eskandari, S. Wang, C.M. Smas, 2016 [1].

  9. Berberine attenuates autophagy in adipocytes by targeting BECN1.

    Science.gov (United States)

    Deng, Yujie; Xu, Jun; Zhang, Xiaoyan; Yang, Jian; Zhang, Di; Huang, Jian; Lv, Pengfei; Shen, Weili; Yang, Ying

    2014-10-01

    The lysosomal degradation pathway, autophagy, is essential for the maintenance of cellular homeostasis. Recently, autophagy has been demonstrated to be required in the process of adipocyte conversion. However, its role in mature adipocytes under physiological and pathological conditions remains unclear. Here, we report a major function of BECN1 in the regulation of basal autophagy in mature adipocytes. We also show that berberine, a natural plant alkaloid, inhibits basal autophagy in adipocytes and adipose tissue of mice fed a high-fat diet via downregulation of BECN1 expression. We further demonstrate that berberine has a pronounced effect on the stability of Becn 1 mRNA through the Mir30 family. These findings explore the potential of BECN1 as a key molecule and a drug target for regulating autophagy in mature adipocytes.

  10. Rosiglitazone regulates IL-6-stimulated lipolysis in porcine adipocytes.

    Science.gov (United States)

    Yang, Yongqing; Yang, Gongshe

    2010-10-01

    Interleukin (IL)-6, a proinflammatory cytokine, stimulates adipocyte lipolysis and induces insulin resistance in obese and diabetic subjects. However, the effects of the anti-diabetic drug rosiglitazone on IL-6-stimulated lipolysis and the underlying molecular mechanism are largely unknown. In this study, we demonstrated that rosiglitazone suppressed IL-6-stimulated lipolysis in differentiated porcine adipocytes by inactivation of extracellular signal-related kinase (ERK). Meanwhile, rosiglitazone enhanced the lipolysis response of adipocytes to isoprenaline. In addition, rosiglitazone significantly reversed IL-6-induced down-regulation of several genes such as perilipin A, peroxisome proliferators activated receptor gamma (PPARγ), and fatty acid synthetase, as well as the up-regulation of IL-6 mRNA. However, mRNA expression of PPARγ coactivator-1 alpha (PCG-1α) was enhanced by rosiglitazone in IL-6-stimulated adipocytes. These results indicate that rosiglitazone suppresses IL-6-stimulated lipolysis in porcine adipocytes through multiple molecular mechanisms.

  11. Recruitment of Brown Adipose Tissue as a Therapy for Obesity-Associated Diseases.

    Directory of Open Access Journals (Sweden)

    STEPHEN ROBERT FARMER

    2012-02-01

    Full Text Available Brown adipose tissue (BAT has been recognized for more than 20 years to play a key role in cold-induced non-shivering thermogenesis (CIT, NST, and body weight homeostasis in animals. BAT is a flexible tissue that can be recruited by stimuli (including small molecules in animals, and atrophies in the absence of a stimulus. In fact, the contribution of BAT (and UCP1 to resting metabolic rate and healthy body weight homeostasis in animals (rodents is now well established. Many investigations have shown that resistance to obesity and associated disorders in various rodent models is due to increased BAT mass and the number of brown adipocytes or UCP1 expression in various depots. The recent discovery of active BAT in adult humans has rekindled the notion that BAT is a therapeutic target for combating obesity-related metabolic disorders. In this review, we highlight investigations performed in rodents that support the contention that activation of BAT formation and/or function in obese individuals is therapeutically powerful. We also propose that enhancement of brown adipocyte functions in white adipose tissue (WAT will also regulate energy balance as well as reduce insulin resistance in obesity-associated inflammation in WAT.

  12. Searching for Brown Dwarf Outflows

    CERN Document Server

    Whelan, E T; Bacciotti, F; Randich, S; Natta, A

    2009-01-01

    As outflow activity in low mass protostars is strongly connected to ac- cretion it is reasonable to expect accreting brown dwarfs to also be driving out- flows. In the last three years we have searched for brown dwarf outflows using high quality optical spectra obtained with UVES on the VLT and the technique of spectro-astrometry. To date five brown dwarf outflows have been discovered. Here the method is discussed and the results to date outlined.

  13. Heart-type fatty acid-binding protein is essential for efficient brown adipose tissue fatty acid oxidation and cold tolerance.

    Science.gov (United States)

    Vergnes, Laurent; Chin, Robert; Young, Stephen G; Reue, Karen

    2011-01-07

    Brown adipose tissue has a central role in thermogenesis to maintain body temperature through energy dissipation in small mammals and has recently been verified to function in adult humans as well. Here, we demonstrate that the heart-type fatty acid-binding protein, FABP3, is essential for cold tolerance and efficient fatty acid oxidation in mouse brown adipose tissue, despite the abundant expression of adipose-type fatty acid-binding protein, FABP4 (also known as aP2). Fabp3(-/-) mice exhibit extreme cold sensitivity despite induction of uncoupling and oxidative genes and hydrolysis of brown adipose tissue lipid stores. However, using FABP3 gain- and loss-of-function approaches in brown adipocytes, we detected a correlation between FABP3 levels and the utilization of exogenous fatty acids. Thus, Fabp3(-/-) brown adipocytes fail to oxidize exogenously supplied fatty acids, whereas enhanced Fabp3 expression promotes more efficient oxidation. These results suggest that FABP3 levels are a determinant of fatty acid oxidation efficiency by brown adipose tissue and that FABP3 represents a potential target for modulation of energy dissipation.

  14. Impaired response of mature adipocytes of diabetic mice to hypoxia

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seok Jong, E-mail: seok-hong@northwestern.edu; Jin, Da P.; Buck, Donald W.; Galiano, Robert D.; Mustoe, Thomas A., E-mail: tmustoe@nmh.org

    2011-10-01

    Adipose tissue contains various cells such as infiltrated monocytes/macrophages, endothelial cells, preadipocytes, and adipocytes. Adipocytes have an endocrine function by secreting adipokines such as interleukin (IL)-6, tumor necrosis factor (TNF)-{alpha}, leptin, and adiponectin. Dysregulation of adipokines in adipose tissues leads to a chronic low-grade inflammation which could result in atherosclerosis, hypertension, and type 2 diabetes. A sustained inflammatory state, which is characterized by prolonged persistence of macrophages and neutrophils, is found in diabetic wounds. In addition, subcutaneous adipocytes are enormously increased in amount clinically in type 2 diabetes. However, the function of subcutaneous adipocytes, which play an important role in injured tissue subjected to hypoxia, has not been well characterized in vitro due to the difficulty of maintaining mature adipocytes in culture using conventional methods because of their buoyancy. In this study, we established a novel in vitro culture method of mature adipocytes by enclosing them in a hyaluronan (HA) based hydrogel to study their role in response to stress such as hypoxia. BrdU labeling and Ki67 immunostaining experiments showed that hydrogel enclosed mature adipocytes proliferate in vitro. Both mRNA and protein expression analyses for hypoxia regulated genes, such as vascular endothelial growth factor (VEGF) and heme oxygenase 1 (HO1), showed that mature adipocytes of wild type mice respond to hypoxia. In contrast, mature adipocytes of diabetic db/db and TallyHo mice did not efficiently respond to hypoxia. Our studies suggest that mature adipocytes are functionally active cells, and their abnormal function to hypoxia can be one of underlining mechanisms in type 2 diabetes.

  15. Staphylococcal superantigens stimulate immortalized human adipocytes to produce chemokines.

    Directory of Open Access Journals (Sweden)

    Bao G Vu

    Full Text Available BACKGROUND: Human adipocytes may have significant functions in wound healing and the development of diabetes through production of pro-inflammatory cytokines after stimulation by gram-negative bacterial endotoxin. Diabetic foot ulcers are most often associated with staphylococcal infections. Adipocyte responses in the area of the wound may play a role in persistence and pathology. We studied the effect of staphylococcal superantigens (SAgs on immortalized human adipocytes, alone and in the presence of bacterial endotoxin or staphylococcal α-toxin. METHODOLOGY/PRINCIPAL FINDINGS: Primary non-diabetic and diabetic human preadipocytes were immortalized by the reverse transcriptase component of telomerase (TERT and the E6/E7 genes of human papillomavirus. The immortal cells were demonstrated to have properties of non-immortalized pre-adipocytes and could be differentiated into mature and functional adipocytes. Differentiated adipocytes exposed to staphylococcal SAgs produced robust levels of cytokines IL-6 and IL-8, but there were no significant differences in levels between the non-diabetic and diabetic cells. Cytokine production was increased by co-incubation of adipocytes with SAgs and endotoxin together. In contrast, α-toxin alone was cytotoxic at high concentrations, but, at sub-cytotoxic doses, did not stimulate production of IL-6 and IL-8. CONCLUSIONS/SIGNIFICANCE: Endotoxin has been proposed to contribute to diabetes through enhanced insulin resistance after chronic exposure and stimulation of adipocytes to produce cytokines. Our data indicate staphylococcal SAgs TSST-1 and SEB alone and in combination with bacterial endotoxin also stimulate adipocytes to produce cytokines and thus may contribute to the inflammatory response found in chronic diabetic ulcers and in the systemic inflammation that is associated with the development and persistence of diabetes. The immortal human pre-adipocytes reported here will be useful for studies to

  16. Regulation of vascular tone by adipocytes

    Directory of Open Access Journals (Sweden)

    Van de Voorde Johan

    2011-03-01

    Full Text Available Abstract Recent studies have shown that adipose tissue is an active endocrine and paracrine organ secreting several mediators called adipokines. Adipokines include hormones, inflammatory cytokines and other proteins. In obesity, adipose tissue becomes dysfunctional, resulting in an overproduction of proinflammatory adipokines and a lower production of anti-inflammatory adipokines. The pathological accumulation of dysfunctional adipose tissue that characterizes obesity is a major risk factor for many other diseases, including type 2 diabetes, cardiovascular disease and hypertension. Multiple physiological roles have been assigned to adipokines, including the regulation of vascular tone. For example, the unidentified adipocyte-derived relaxing factor (ADRF released from adipose tissue has been shown to relax arteries. Besides ADRF, other adipokines such as adiponectin, omentin and visfatin are vasorelaxants. On the other hand, angiotensin II and resistin are vasoconstrictors released by adipocytes. Reactive oxygen species, leptin, tumour necrosis factor α, interleukin-6 and apelin share both vasorelaxing and constricting properties. Dysregulated synthesis of the vasoactive and proinflammatory adipokines may underlie the compromised vascular reactivity in obesity and obesity-related disorders.

  17. Genistein inhibits differentiation of primary human adipocytes.

    Science.gov (United States)

    Park, Hea Jin; Della-Fera, Mary Anne; Hausman, Dorothy B; Rayalam, Srujana; Ambati, Suresh; Baile, Clifton A

    2009-02-01

    Genistein, a major soy isoflavone, has been reported to exhibit antiadipogenic and proapoptotic potential in vivo and in vitro. It is also a phytoestrogen which has high affinity to estrogen receptor beta. In this study, we determined the effect of genistein on adipogenesis and estrogen receptor (ER) alpha and beta expression during differentiation in primary human preadipocytes. Genistein inhibited lipid accumulation in a dose-dependent manner at concentrations of 6.25 microM and higher, with 50 microM genistein inhibiting lipid accumulation almost completely. Low concentrations of genistein (3.25 microM) increased cell viability and higher concentrations (25 and 50 microM) decreased it by 16.48+/-1.35% (P<.0001) and 50.68+/-1.34% (P<.0001). Oil Red O staining was used to confirm the effects on lipid accumulation. The inhibition of lipid accumulation was associated with inhibition of glycerol-3-phosphate dehydrogenase activity and down-regulation of expression of adipocyte-specific genes, including peroxisome proliferator-activated receptor gamma, CCAAT/enhancer binding protein alpha, glycerol-3-phosphate dehydrogenase, adipocyte fatty acid binding protein, fatty acid synthase, sterol regulatory element-binding protein 1, perilipin, leptin, lipoprotein lipase and hormone-sensitive lipase. These effects of genistein during the differentiation period were associated with down-regulation of ERalpha and ERbeta expression. This study adds to the elucidation of the molecular pathways involved in the inhibition of adipogenesis by phytoestrogens.

  18. Regulation of brown fat adipogenesis by protein tyrosine phosphatase 1B.

    Directory of Open Access Journals (Sweden)

    Kosuke Matsuo

    Full Text Available Protein-tyrosine phosphatase 1B (PTP1B is a physiological regulator of insulin signaling and energy balance, but its role in brown fat adipogenesis requires additional investigation.To precisely determine the role of PTP1B in adipogenesis, we established preadipocyte cell lines from wild type and PTP1B knockout (KO mice. In addition, we reconstituted KO cells with wild type, substrate-trapping (D/A and sumoylation-resistant (K/R PTP1B mutants, then characterized differentiation and signaling in these cells. KO, D/A- and WT-reconstituted cells fully differentiated into mature adipocytes with KO and D/A cells exhibiting a trend for enhanced differentiation. In contrast, K/R cells exhibited marked attenuation in differentiation and lipid accumulation compared with WT cells. Expression of adipogenic markers PPARγ, C/EBPα, C/EBPδ, and PGC1α mirrored the differentiation pattern. In addition, the differentiation deficit in K/R cells could be reversed completely by the PPARγ activator troglitazone. PTP1B deficiency enhanced insulin receptor (IR and insulin receptor substrate 1 (IRS1 tyrosyl phosphorylation, while K/R cells exhibited attenuated insulin-induced IR and IRS1 phosphorylation and glucose uptake compared with WT cells. In addition, substrate-trapping studies revealed that IRS1 is a substrate for PTP1B in brown adipocytes. Moreover, KO, D/A and K/R cells exhibited elevated AMPK and ACC phosphorylation compared with WT cells.These data indicate that PTP1B is a modulator of brown fat adipogenesis and suggest that adipocyte differentiation requires regulated expression of PTP1B.

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  4. File list: ALL.Adp.50.AllAg.Adipocytes [Chip-atlas[Archive

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  5. File list: ALL.Adp.10.AllAg.Adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Adp.10.AllAg.Adipocytes hg19 All antigens Adipocyte Adipocytes SRX027402,SRX682...086,SRX682084,SRX027400,SRX682085,SRX682083,SRX027403,SRX027401,SRX027404 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Adp.10.AllAg.Adipocytes.bed ...

  6. File list: Pol.Adp.10.AllAg.Adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Adp.10.AllAg.Adipocytes hg19 RNA polymerase Adipocyte Adipocytes SRX682086,SRX6...82084,SRX682085,SRX682083 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.Adp.10.AllAg.Adipocytes.bed ...

  7. Human adipocyte function is impacted by mechanical cues.

    Science.gov (United States)

    Pellegrinelli, V; Heuvingh, J; du Roure, O; Rouault, C; Devulder, A; Klein, C; Lacasa, M; Clément, E; Lacasa, D; Clément, K

    2014-06-01

    Fibrosis is a hallmark of human white adipose tissue (WAT) during obesity-induced chronic inflammation. The functional impact of increased interstitial fibrosis (peri-adipocyte fibrosis) on adjacent adipocytes remains unknown. Here we developed a novel in vitro 3D culture system in which human adipocytes and decellularized material of adipose tissue (dMAT) from obese subjects are embedded in a peptide hydrogel. When cultured with dMAT, adipocytes showed decreased lipolysis and adipokine secretion and increased expression/production of cytokines (IL-6, G-CSF) and fibrotic mediators (LOXL2 and the matricellular proteins THSB2 and CTGF). Moreover, some alterations including lipolytic activity and fibro-inflammation also occurred when the adipocyte/hydrogel culture was mechanically compressed. Notably, CTGF expression levels correlated with the amount of peri-adipocyte fibrosis in WAT from obese individuals. Moreover, dMAT-dependent CTGF promoter activity, which depends on β1-integrin/cytoskeleton pathways, was enhanced in the presence of YAP, a mechanosensitive co-activator of TEAD transcription factors. Mutation of TEAD binding sites abolished the dMAT-induced promoter activity. In conclusion, fibrosis may negatively affect human adipocyte function via mechanosensitive molecules, in part stimulated by cell deformation. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  8. Female adipocyte androgen synthesis and the effects of insulin

    Directory of Open Access Journals (Sweden)

    David Cadagan

    2014-01-01

    Full Text Available The metabolic syndrome is a cluster of metabolic disorders characterized by insulin resistance and hyperinsulinaemia, and its presence can increase the risk of cardiovascular disease significantly. The metabolic syndrome is associated with increased circulating androgen levels in women, which may originate from the ovaries and adrenal glands. Adipocytes are also able to synthesise steroid hormones, and this output has been hypothesised to increase with elevated insulin plasma concentrations. However, the contribution of the adipocytes to the circulating androgen levels in women with metabolic syndrome is limited and the effects of insulin are not fully understood. The aim of this study was to investigate the presence of steroid precursors and synthetic enzymes in human adipocyte biopsies as markers of possible adipocyte androgen synthesis. We examined pre and mature adipocytes taken from tissue biopsies of abdominal subcutaneous adipose tissue of participating women from the Department of Obstetrics and Gynaecology, of the Royal Derby Hospital. The results showed the potential for localised adipocyte androgen synthesis through the presence of the androgen precursor progesterone, as well as the steroid-converting enzyme 17α-hydroxylase. Furthermore, we found the controlled secretion of androstenedione in vitro and that insulin treatment caused levels to increase. Continued examination of a localised source of androgen production is therefore of clinical relevance due to its influence on adipocyte metabolism, its negative impact on female steroidogenic homeostasis, and the possible aggravation this may have when associated to obesity and obesity related metabolic abnormalities such as hyperinsulinaemia.

  9. A study of genes involved in adipocyte differentiation.

    Science.gov (United States)

    Zhu, Shunming; Cheng, Gong; Zhu, Huolan; Guan, Gongchang

    2015-01-01

    With the use of the microarray technique, genes expressed in the late phase of adipocyte differentiation were investigated. These genes play an important role in stimulating adipocyte growth and lipid droplet formation. Therefore, they contribute a great deal to the onset of obesity. With the use of SW872 adipocytes and the microarray technique, genes related to adipocyte differentiation were tested and compared with undifferentiated preadipocytes 14 days after induction. Real-time reverse transcription polymerase chain reaction (RT-PCR) was used for confirmation. More than 21,329 transcriptors were expressed and determined, of which 1326 increased and 687 decreased undifferentiated adipocytes. Among them, 21 were highly expressed by more than 10-fold. With RT-PCR, 12 were confirmed, including apelin, CIDEC, PID1, LYRM1, ADD1, PPARγ2, ANGPTL4, ADIPOQ, ACOX1, FIP1L1, MAP3K2 and PEX14. Furthermore, genes involved in lipid metabolism, signal transduction, DNA replication, redox status and transcription factors were determined as well. Novel genes involved in adipogenesis (e.g., apelin) were detected. A variety of genes were discovered and validated with RT-PCR at the late phase of adipocyte differentiation. This may help us better understand the onset of obesity and the potential role of adipocytes in other organs.

  10. Maraviroc shows differential effects on glucose uptake and lipolysis in human subcutaneous cultured adipocytes in comparison with omental adipocytes

    Directory of Open Access Journals (Sweden)

    P Perez-Matute

    2012-11-01

    Full Text Available Maraviroc (MVC, the first approved CC-chemokine receptor 5 (CCR5 antagonist, is used for treating HIV-1-infected patients with CCR5 tropism. MVC has been proved safe in all respects and showed beneficial effects on lipid profile of HIV patients with dislipidemia. Adipocyte dysfunction seems to be responsible for many metabolic alterations such as insulin resistance and dislipidemia. Subcutaneous and visceral fat depots are not only physiologically but also metabolically different and metabolic disturbances are more closely associated with visceral than subcutaneous fat accumulation. It has been suggested that antiretrovirals affect both fat depots in a different extent. Thus, whether isolated human adipocytes display regio-specific sensitivity to the metabolic effects of MVC have been tested in this study. Human subcutaneous and omental preadipocytes were used as the source of human adipocytes. These cells were treated with therapeutic concentrations of MVC (0.5–25 µM at day 14 post-differentiation (4 and 24 hours of treatment. Glucose utilization, lactate production and glycerol released into the media were measured using an autoanalyzer. Adiponectin secretion was determined by an ELISA array. A dose-dependent increase in glucose uptake was observed in subcutaneous adipocytes treated with MVC (+72% of stimulation for MVC 25 µM, p < 0.01. This stimulatory effect was tissue specific, as no effects were observed in omental adipocytes. MVC did not exert any significant effect on adiponectin secretion. No significant effects were observed on lactate production neither in subcutaneous nor omental adipocytes. Interestingly, 4 hours of treatment with MVC induced a significant increase in the amount of glycerol released into the media by subcutaneous adipocytes (p < 0.001, but this effect disappeared with longer exposure of adipocytes to MVC (24 h. No effects were observed on lipolysis in omental adipocytes although a slight tendency to

  11. Metabolic activity of brown, "beige," and white adipose tissues in response to chronic adrenergic stimulation in male mice.

    Science.gov (United States)

    Labbé, Sébastien M; Caron, Alexandre; Chechi, Kanta; Laplante, Mathieu; Lecomte, Roger; Richard, Denis

    2016-07-01

    Classical brown adipocytes such as those found in interscapular brown adipose tissue (iBAT) represent energy-burning cells, which have been postulated to play a pivotal role in energy metabolism. Brown adipocytes can also be found in white adipose tissue (WAT) depots [e.g., inguinal WAT (iWAT)] following adrenergic stimulation, and they have been referred to as "beige" adipocytes. Whether the presence of these adipocytes, which gives iWAT a beige appearance, can confer a white depot with some thermogenic activity remains to be seen. In consequence, we designed the present study to investigate the metabolic activity of iBAT, iWAT, and epididymal white depots in mice. Mice were either 1) kept at thermoneutrality (30°C), 2) kept at 30°C and treated daily for 14 days with an adrenergic agonist [CL-316,243 (CL)], or 3) housed at 10°C for 14 days. Metabolic activity was assessed using positron emission tomography imaging with fluoro-[(18)F]deoxyglucose (glucose uptake), fluoro-[(18)F]thiaheptadecanoic acid (fatty acid uptake), and [(11)C]acetate (oxidative activity). In each group, substrate uptakes and oxidative activity were measured in anesthetized mice in response to acute CL. Our results revealed iBAT as a major site of metabolic activity, which exhibited enhanced glucose and nonesterified fatty acid uptakes and oxidative activity in response to chronic cold and CL. On the other hand, beige adipose tissue failed to exhibit appreciable increase in oxidative activity in response to chronic cold and CL. Altogether, our results suggest that the contribution of beige fat to acute-CL-induced metabolic activity is low compared with that of iBAT, even after sustained adrenergic stimulation.

  12. Understanding the effects of mature adipocytes and endothelial cells on fatty acid metabolism and vascular tone in physiological fatty tissue for vascularized adipose tissue engineering.

    Science.gov (United States)

    Huber, Birgit; Volz, Ann-Cathrin; Kluger, Petra J

    2015-11-01

    Engineering of large vascularized adipose tissue constructs is still a challenge for the treatment of extensive high-graded burns or the replacement of tissue after tumor removal. Communication between mature adipocytes and endothelial cells is important for homeostasis and the maintenance of adipose tissue mass but, to date, is mainly neglected in tissue engineering strategies. Thus, new co-culture strategies are needed to integrate adipocytes and endothelial cells successfully into a functional construct. This review focuses on the cross-talk of mature adipocytes and endothelial cells and considers their influence on fatty acid metabolism and vascular tone. In addition, the properties and challenges with regard to these two cell types for vascularized tissue engineering are highlighted.

  13. Tune Your Brown Clustering, Please

    DEFF Research Database (Denmark)

    Derczynski, Leon; Chester, Sean; Bøgh, Kenneth Sejdenfaden

    2015-01-01

    unexplored. Accordingly, we present information for practitioners on the behaviour of Brown clustering in order to assist hyper-parametre tuning, in the form of a theoretical model of Brown clustering utility. This model is then evaluated empirically in two sequence labelling tasks over two text types. We...

  14. Apolipoprotein E synthesized by adipocyte and apolipoprotein E carried on lipoproteins modulate adipocyte triglyceride content

    OpenAIRE

    Li, Yan-Hong; Liu, Ling

    2014-01-01

    Excessive energy storage of adipose tissue makes contribution to the occurrence and progression of obesity, which accompanies with multiple adverse complications, such as metabolic syndrome, cardiovascular diseases. It is well known that apolipoprotein E, as a component of lipoproteins, performs a key role in maintaining plasma lipoproteins homeostasis. Interestingly, apolipoprotein E is highly expressed in adipocyte and has positive relation with body fat mass. Apolipoprotein E knock-out mic...

  15. Oestrogen alters adipocyte biology and protects female mice from adipocyte inflammation and insulin resistance.

    Science.gov (United States)

    Stubbins, R E; Najjar, K; Holcomb, V B; Hong, J; Núñez, N P

    2012-01-01

    Obesity is associated with insulin resistance, liver steatosis and low-grade inflammation. The role of oestrogen in sex differences in the above co-morbidities is not fully understood. Our aim was to assess the role oestrogen has in modulating adipocyte size, adipose tissue oxidative stress, inflammation, insulin resistance and liver steatosis. To determine the role oestrogen has in the above co-morbidities related to obesity, we randomized C57BL/6J mice into four groups (15 mice per group): (i) male, (ii) non-ovariectomized female (novx), (iii) ovariectomized female (ovx) and (iv) ovariectomized female mice supplemented with 17β estradiol (ovx-E). Mice received either a low-fat (LF) or a high-fat (HF) diet for 10 weeks. Outcomes measured were bodyweight, body fat, adipocyte diameter, adipose tissue lipolysis markers, adipose tissue oxidative stress, inflammation, insulin resistance and liver steatosis. Male and ovx-female mice consuming the HF diet had a higher propensity of gaining weight, specifically in the form of body fat. Oestrogen protected female mice from adipocyte hypertrophy and from developing adipose tissue oxidative stress and inflammation. Moreover, novx-female and ovx-female+E mice had higher phosphorylated levels of protein kinase A and hormone sensitive lipase, markers associated with lipolysis. Additionally, male and ovx female mice had a higher propensity of developing liver steatosis and insulin resistance. In contrast, oestrogen protected female mice from developing liver steatosis and from becoming insulin resistant. We show that oestrogen protects female mice from adipocyte hypertrophy and adipose tissue oxidative stress and inflammation. Furthermore, oestrogen prevented female mice from developing liver steatosis and from becoming insulin resistant. © 2011 Blackwell Publishing Ltd.

  16. Physiological response of adipocytes to weight loss and maintenance.

    Directory of Open Access Journals (Sweden)

    Sanne P M Verhoef

    Full Text Available BACKGROUND: Metabolic processes in adipose tissue are dysregulated in obese subjects and, in response to weight loss, either normalize or change in favor of weight regain. OBJECTIVE: To determine changes in adipocyte glucose and fatty acid metabolism in relation to changes in adipocyte size during weight loss and maintenance. METHODS: Twenty-eight healthy subjects (12 males, age 20-50 y, and BMI 28-35 kg/m(2, followed a very low energy diet for 2 months, followed by a 10-month period of weight maintenance. Body weight, body composition (deuterium dilution and BodPod, protein levels (Western blot and adipocyte size were assessed prior to and after weight loss and after the 10-month follow-up. RESULTS: A 10% weight loss resulted in a 16% decrease in adipocyte size. A marker for glycolysis decreased (AldoC during weight loss in association with adipocyte shrinking, and remained decreased during follow-up in association with weight maintenance. A marker for fatty acid transport increased (FABP4 during weight loss and remained increased during follow-up. Markers for mitochondrial beta-oxidation (HADHsc and lipolysis (ATGL were only increased after the 10-month follow-up. During weight loss HADHsc and ATGL were coordinately regulated, which became weaker during follow-up due to adipocyte size-related changes in HADHsc expression. AldoC was the major denominator of adipocyte size and body weight, whereas changes in ATGL during weight loss contributed to body weight during follow-up. Upregulation of ATGL and HADHsc occured in the absence of a negative energy balance and was triggered by adipocyte shrinkage or indicated preadipocyte differentiation. CONCLUSION: Markers for adipocyte glucose and fatty acid metabolism are changed in response to weight loss in line with normalization from a dysregulated obese status to an improved metabolic status. TRIAL REGISTRATION: ClinicalTrials.gov NCT01015508.

  17. Physiological response of adipocytes to weight loss and maintenance.

    Science.gov (United States)

    Verhoef, Sanne P M; Camps, Stefan G J A; Bouwman, Freek G; Mariman, Edwin C M; Westerterp, Klaas R

    2013-01-01

    Metabolic processes in adipose tissue are dysregulated in obese subjects and, in response to weight loss, either normalize or change in favor of weight regain. To determine changes in adipocyte glucose and fatty acid metabolism in relation to changes in adipocyte size during weight loss and maintenance. Twenty-eight healthy subjects (12 males), age 20-50 y, and BMI 28-35 kg/m(2), followed a very low energy diet for 2 months, followed by a 10-month period of weight maintenance. Body weight, body composition (deuterium dilution and BodPod), protein levels (Western blot) and adipocyte size were assessed prior to and after weight loss and after the 10-month follow-up. A 10% weight loss resulted in a 16% decrease in adipocyte size. A marker for glycolysis decreased (AldoC) during weight loss in association with adipocyte shrinking, and remained decreased during follow-up in association with weight maintenance. A marker for fatty acid transport increased (FABP4) during weight loss and remained increased during follow-up. Markers for mitochondrial beta-oxidation (HADHsc) and lipolysis (ATGL) were only increased after the 10-month follow-up. During weight loss HADHsc and ATGL were coordinately regulated, which became weaker during follow-up due to adipocyte size-related changes in HADHsc expression. AldoC was the major denominator of adipocyte size and body weight, whereas changes in ATGL during weight loss contributed to body weight during follow-up. Upregulation of ATGL and HADHsc occured in the absence of a negative energy balance and was triggered by adipocyte shrinkage or indicated preadipocyte differentiation. Markers for adipocyte glucose and fatty acid metabolism are changed in response to weight loss in line with normalization from a dysregulated obese status to an improved metabolic status. ClinicalTrials.gov NCT01015508.

  18. Cancer-associated adipocytes promotes breast tumor radioresistance

    Energy Technology Data Exchange (ETDEWEB)

    Bochet, Ludivine; Meulle, Aline [Universite de Toulouse, UPS, F-31077 Toulouse Cedex (France); CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, BP 64182, F-31077 Toulouse Cedex (France); Institut National de la Sante et de la Recherche Medicale, INSERM U1048, 1 Avenue du Pr Jean Poulhes, BP 84225, F-31432 Toulouse Cedex (France); Imbert, Sandrine [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, BP 64182, F-31077 Toulouse Cedex (France); Salles, Bernard [Universite de Toulouse, UPS, F-31077 Toulouse Cedex (France); CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, BP 64182, F-31077 Toulouse Cedex (France); Valet, Philippe [Universite de Toulouse, UPS, F-31077 Toulouse Cedex (France); Institut National de la Sante et de la Recherche Medicale, INSERM U1048, 1 Avenue du Pr Jean Poulhes, BP 84225, F-31432 Toulouse Cedex (France); Muller, Catherine, E-mail: muller@ipbs.fr [Universite de Toulouse, UPS, F-31077 Toulouse Cedex (France); CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, BP 64182, F-31077 Toulouse Cedex (France)

    2011-07-22

    Highlights: {yields} Tumor-surrounding adipocytes contribute to breast cancer progression. {yields} Breast tumor cells previously co-cultivated with mature adipocytes exhibit radioresistance. {yields} Increased in Chk1 phosphorylation is observed in irradiated co-cultivated tumor cells. {yields} IL-6 is over-expressed in tumor cells co-cultivated with adipocytes. {yields} IL-6 exposure confers increased Chk1 phosphorylation and radioresistance in tumor cells. -- Abstract: Mature adipocytes are excellent candidates to influence tumor behavior through heterotypic signaling processes since these cells produce hormones, growth factors, cytokines and other molecules, a heterogeneous group of molecules named adipokines. Using a 2D coculture system, we demonstrate that breast tumor cells previously co-cultivated with mature adipocytes exhibit radioresistance and an earlier and higher increase in the effector kinase Chk1, a phenotype that was associated with decreased cell death as compared to tumor cells grown alone. Interestingly, the adipocytes-induced tumor changes taking place during the coculture time preceding the exposure to IR were sufficient to confer the radioresistant effect. Notorious among the changes brought by adipocytes was the significant increase of IL-6 expression in tumor cells, whose activity may well account for the observed tumor cell protection from IR toxicity. Indeed, our data confirmed the protective role of this cytokine as tumor cells incubated after irradiation with recombinant IL-6 exhibit an increased in Chk1 phosphorylation and a radioresistant phenotype, thus far recapitulating the effects observed in the presence of adipocytes. Our current study sheds light on a new role of tumor-surrounding adipocytes in fostering a radioresistant phenotype in breast tumors, a finding that might have important clinical implications in obese patients that frequently exhibit aggressive diseases.

  19. Direct and indirect effects of leptin on adipocyte metabolism.

    Science.gov (United States)

    Harris, Ruth B S

    2014-03-01

    Leptin is hypothesized to function as a negative feedback signal in the regulation of energy balance. It is produced primarily by adipose tissue and circulating concentrations correlate with the size of body fat stores. Administration of exogenous leptin to normal weight, leptin responsive animals inhibits food intake and reduces the size of body fat stores whereas mice that are deficient in either leptin or functional leptin receptors are hyperphagic and obese, consistent with a role for leptin in the control of body weight. This review discusses the effect of leptin on adipocyte metabolism. Because adipocytes express leptin receptors there is the potential for leptin to influence adipocyte metabolism directly. Adipocytes also are insulin responsive and receive sympathetic innervation, therefore leptin can also modify adipocyte metabolism indirectly. Studies published to date suggest that direct activation of adipocyte leptin receptors has little effect on cell metabolism in vivo, but that leptin modifies adipocyte sensitivity to insulin to inhibit lipid accumulation. In vivo administration of leptin leads to a suppression of lipogenesis, an increase in triglyceride hydrolysis and an increase in fatty acid and glucose oxidation. Activation of central leptin receptors also contributes to the development of a catabolic state in adipocytes, but this may vary between different fat depots. Leptin reduces the size of white fat depots by inhibiting cell proliferation both through induction of inhibitory circulating factors and by contributing to sympathetic tone which suppresses adipocyte proliferation. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Suppression of adipocyte hypertrophy by polymethoxyflavonoids isolated from Kaempferia parviflora.

    Science.gov (United States)

    Okabe, Yui; Shimada, Tsutomu; Horikawa, Takumi; Kinoshita, Kaoru; Koyama, Kiyotaka; Ichinose, Koji; Aburada, Masaki; Takahashi, Kunio

    2014-05-15

    We previously demonstrated that ethyl acetate extracts of Kaempferia parviflora Wall. Ex Baker (KPE) improve insulin resistance in TSOD mice and showed that its components induce differentiation and adipogenesis in 3T3-L1 preadipocytes. The present study was undertaken to examine whether KPE and its isolated twelve components suppress further lipid accumulation in 3T3-L1 mature adipocytes. KPE reduced intracellular triglycerides in mature adipocytes, as did two of its components, 3,5,7,3',4'-pentamethoxyflavone and 5,7,4'-trimethoxyflavone. Shrinkage of lipid droplets in mature adipocytes was observed, and mRNA expression levels of adipose tissue triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) were up-regulated by these two polymethoxyflavonoids (PMFs). Furthermore, the protein expression level of ATGL and the release level of glycerol into the cell culture medium increased. In contrast, the peroxisome proliferator-activated receptor γ (PPARγ) agonist, troglitazone, did not decrease intracellular triglycerides in mature adipocytes, and the mRNA expression level of PPARγ was not up-regulated in mature adipocytes treated with the two active PMFs. Therefore, suppression of lipid accumulation in mature adipocytes is unlikely to be enhanced by transcriptional activation of PPARγ. These results suggest that KPE and its active components enhance lipolysis in mature adipocytes by activation of ATGL and HSL independent of PPARγ transcription, thus preventing adipocyte hypertrophy. On the other hand, the full hydroxylated flavonoid quercetin did not show the suppressive effects of lipid accumulation in mature adipocyte in the same conditions. Consequently, methoxy groups in the flavones are important for the activity. Copyright © 2014 Elsevier GmbH. All rights reserved.

  1. [Adipose triglyceride lipase regulates adipocyte lipolysis].

    Science.gov (United States)

    Xu, Chong; Xu, Guo-Heng

    2008-01-01

    Obesity, insulin resistance, and type 2 diabetes are associated with elevated concentration of circulating free fatty acids (FFAs), which are critically governed by the process of triglyceride lipolysis in adipocytes. Hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) are two major enzymes in the control of triacylglycerol hydrolysis in adipose tissue. ATGL expressed predominantly in white adipose tissue specifically initiates triacylglycerol hydrolysis to generate diacylglycerols and FFA, a role distinguished from HSL that mainly hydrolyzes diacylglycerols. The transcription of ATGL is regulated by several factors. ATGL activity is regulated by CGI-58. Under basal conditions, interaction of CGI-58 with a lipid droplet associating protein, perilipin, results in an inactivation of ATGL activity. During PKA-stimulated lipolysis, CGI-58 is released from phosphorylated perilipin and in turn, binds to ATGL. This action facilitates triglyceride lipolysis. This review focuses on the regulation and function of ATGL in adipose lipolysis and metabolism.

  2. Contrasting effects of cold acclimation versus obesogenic diets on chemerin gene expression in brown and brite adipose tissues.

    Science.gov (United States)

    Hansen, Ida R; Jansson, Kim M; Cannon, Barbara; Nedergaard, Jan

    2014-12-01

    Based on results from a signal sequence trap, we investigated chemerin gene expression in brown adipose tissue. Male NMRI mice were exposed to 30, 22 or 4 °C for 3 weeks, or were fed control (chow) diet, cafeteria diet or high-fat diet at thermoneutrality for the same time. In brown adipose tissue, cold acclimation strongly diminished chemerin gene expression, whereas obesogenic diets augmented expression. Qualitatively, changes in expression were paralleled in brite/beige adipose tissues (e.g. inguinal), whereas white adipose tissue (epididymal) and muscle did not react to these cues. Changes in tissue expression were not directly paralleled by alterations in plasma levels. Both these intact animal studies and brown adipocyte cell culture studies indicated that the gene expression regulation was not congruent with a sympathetic/adrenergic control. The data are discussed in relation to suggested endocrine, paracrine and autocrine effects of chemerin.

  3. Interleukin-17A inhibits adipocyte differentiation in human mesenchymal stem cells and regulates pro-inflammatory responses in adipocytes.

    Science.gov (United States)

    Shin, Jennifer H; Shin, Dong Wook; Noh, Minsoo

    2009-06-15

    The immune system is closely linked to human metabolic diseases. Serum levels of IL-6 increase with obesity and insulin resistance. Not only does IL-6 decrease the insulin sensitivity of human cells such as adipocytes, but it also regulates the lineage commitment of naïve T cells into interleukin (IL)-17A-producing CD4(+) T (Th17) cells. Although IL-17A exerts a variety of effects on somatic tissues, its functional role in human adipocytes has not been identified. In this work, we show that IL-17A inhibits adipocyte differentiation in human bone marrow mesenchymal stem cells (hBM-MSCs), while promoting lipolysis of differentiated adipocytes. We find that IL-17A increases both mRNA and protein secretion of IL-6 and IL-8 during adipocyte differentiation in hBM-MSCs. IL-17A up-regulates cyclooxygenase (COX)-2 gene expression and thereby increases the level of prostaglandin (PG) E(2) in differentiated adipocyes. The suppression of anti-adipogenic PGE(2) by COX inhibitors such as aspirin and NS-398 partially blocked the effect of IL-17A on adipocyte differentiation in hBM-MSCs. Therefore, IL-17A exhibits its inhibitory effect in part via the COX-2 induction in differentiated adipocytes. In addition, treatment with anti-IL-17A antibody neutralizes IL-17A-mediated effects on adipocyte differentiation and function. These results suggest that IL-17A plays a regulatory role in both the metabolic and inflammatory processes of human adipocytes, similar to other pro-inflammatory cytokines such as IL-1, IFNgamma, and TNFalpha.

  4. Molecular clock integration of brown adipose tissue formation and function.

    Science.gov (United States)

    Nam, Deokhwa; Yechoor, Vijay K; Ma, Ke

    2016-01-01

    The circadian clock is an essential time-keeping mechanism that entrains internal physiology to environmental cues. Despite the well-established link between the molecular clock and metabolic homeostasis, an intimate interplay between the clock machinery and the metabolically active brown adipose tissue (BAT) is only emerging. Recently, we came to appreciate that the formation and metabolic functions of BAT, a key organ for body temperature maintenance, are under an orchestrated circadian clock regulation. Two complementary studies from our group uncover that the cell-intrinsic clock machinery exerts concerted control of brown adipogenesis with consequent impacts on adaptive thermogenesis, which adds a previously unappreciated temporal dimension to the regulatory mechanisms governing BAT development and function. The essential clock transcriptional activator, Bmal1, suppresses adipocyte lineage commitment and differentiation, whereas the clock repressor, Rev-erbα, promotes these processes. This newly discovered temporal mechanism in fine-tuning BAT thermogenic capacity may enable energy utilization and body temperature regulation in accordance with external timing signals during development and functional recruitment. Given the important role of BAT in whole-body metabolic homeostasis, pharmacological interventions targeting the BAT-modulatory activities of the clock circuit may offer new avenues for the prevention and treatment of metabolic disorders, particularly those associated with circadian dysregulation.

  5. Extrasolar Giant Planet and Brown Dwarf Models

    CERN Document Server

    Burrows, A; Lunine, J I; Guillot, M P; Saumon, D S; Freedman, R S

    1997-01-01

    With the discovery of the companions of 51 Peg, 55 Cnc, $\\tau$ Boo, gas giants and/or brown dwarfs with masses from 0.3 through 60 times that of Jupiter assume a new and central role in the emerging field of extrasolar planetary studies. In this contribution, we describe the structural, spectral, and evolutionary characteristics of such exotic objects, as determined by our recent theoretical calculations. These calculations can be used to establish direct search strategies via SIRTF, ISO, and HST (NICMOS), and via various ground--based adaptive optics and interferometric platforms planned for the near future.

  6. 脂肪细胞的功能调节与脂肪组织重构%Functional regulation of adipocytes and adipose tissue remodeling

    Institute of Scientific and Technical Information of China (English)

    马度芳; 李晓

    2016-01-01

    Adipocytes are classified into three types, including white, brown, and “beige/brite” adipocytes. There exist differences in origin of adipocytes, gene expressions, morphology, and functions among three kinds of adipocytes. Multiple factors such as physical and chemical factors, neurohormonal and immunological factors, transcriptional factors have been shown to regulate and control the browning process and lipolysis of white adipose tissue. Thus, they may become new targets for anti-obesity intervention. In the process of obesity, chronic inflammation reaction, adipose tissue remodeling and abnormal angiogenesis occurring in the adipose tissue cause pathological fat expansion and reduce lipid storage in adipocytes. Understanding adipocytes biology is important to decipher how the aberrant adipose tissue contributes to obesity and metabolic disorders, and provides guidance for treating obesity.%脂肪细胞分为白色脂肪细胞、棕色脂肪细胞和米色脂肪细胞,三者在细胞来源、基因表达、形态学及功能方面存在差异。机体理化因素、神经内分泌和免疫因素、转录因子等多种因素可调控白色脂肪“棕色化”和脂肪分解。这些因素可能是药物干预的新靶点。肥胖时脂肪组织慢性炎症、纤维化和血管异常可导致脂肪扩充障碍,降低脂肪细胞的储脂能力。了解脂肪组织的这些生物学特性可揭示异常的脂肪组织如何导致肥胖以及肥胖相关的代谢紊乱,而且对于肥胖的治疗具有指导性意义。

  7. Dedifferentiated adipocyte-derived progeny cells (DFAT cells)

    Science.gov (United States)

    Wei, Shengjuan; Zan, Linsen; Hausman, Gary J; Rasmussen, Theodore P; Bergen, Werner G; Dodson, Michael V

    2013-01-01

    Analyses of mature adipocytes have shown that they possess a reprogramming ability in vitro, which is associated with dedifferentiation. The subsequent dedifferentiated fat cells (DFAT cells) are multipotent and can differentiate into adipocytes and other cell types as well. Mature adipocytes can be easily obtained by biopsy, and the cloned progeny cells are homogeneous in vitro. Therefore, DFAT cells (a new type of stem cell) may provide an excellent source of cells for tissue regeneration, engineering and disease treatment. The dedifferentiation of mature adipocytes, the multipotent capacity of DFAT cells and comparisons and contrasts with mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPS) are discussed in this review. PMID:23991357

  8. Adipose tissue and adipocytes support tumorigenesis and metastasis.

    Science.gov (United States)

    Nieman, Kristin M; Romero, Iris L; Van Houten, Bennett; Lengyel, Ernst

    2013-10-01

    Adipose tissue influences tumor development in two major ways. First, obese individuals have a higher risk of developing certain cancers (endometrial, esophageal, and renal cell cancer). However, the risk of developing other cancers (melanoma, rectal, and ovarian) is not altered by body mass. In obesity, hypertrophied adipose tissue depots are characterized by a state of low grade inflammation. In this activated state, adipocytes and inflammatory cells secrete adipokines and cytokines which are known to promote tumor development. In addition, the adipocyte mediated conversion of androgens to estrogen specifically contributes to the development of endometrial cancer, which shows the greatest relative risk (6.3-fold) increase between lean and obese individuals. Second, many tumor types (gastric, breast, colon, renal, and ovarian) grow in the anatomical vicinity of adipose tissue. During their interaction with cancer cells, adipocytes dedifferentiate into pre-adipocytes or are reprogrammed into cancer-associated adipocytes (CAA). CAA secrete adipokines which stimulate the adhesion, migration, and invasion of tumor cells. Cancer cells and CAA also engage in a dynamic exchange of metabolites. Specifically, CAA release fatty acids through lipolysis which are then transferred to cancer cells and used for energy production through β-oxidation. The abundant availability of lipids from adipocytes in the tumor microenvironment, supports tumor progression and uncontrolled growth. Given that adipocytes are a major source of adipokines and energy for the cancer cell, understanding the mechanisms of metabolic symbiosis between cancer cells and adipocytes, should reveal new therapeutic possibilities. This article is part of a Special Issue entitled Lipid Metabolism in Cancer. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Adipocyte secreted factors enhance aggressiveness of prostate carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Ângela Moreira

    Full Text Available Obesity has been associated with increased incidence and risk of mortality of prostate cancer. One of the proposed mechanisms underlying this risk association is the change in adipokines expression that could promote the development and progression of the prostate tumor cells. The main goal of this study was to evaluate the effect of preadipocyte and adipocyte secretome in the proliferation, migration and invasion of androgen independent prostate carcinoma cells (RM1 and to assess cell proliferation in the presence of the adiposity signals leptin and insulin. RM1 cells were co-cultured in with preadipocytes, adipocytes or cultured in their respective conditioned medium. Cell proliferation was assessed by flow cytometry and XTT viability test. Cell migration was evaluated using a wound healing injury assay of RM1 cells cultured with conditioned media. Cellular invasion of RM1 cells co-cultured with adipocytes and preadipocytes was assessed using matrigel membranes. Preadipocyte conditioned medium was associated with a small increase in RM1 proliferation, while adipocytes conditioned media significantly increased RM1 cell proliferation (p<0.01. Adipocytes also significantly increased the RM1 cells proliferation in co-culture (p <0.01. Cell migration was higher in RM1 cells cultured with preadipocyte and adipocyte conditioned medium. RM1 cell invasion was significantly increased after co-culture with preadipocytes and adipocytes (p <0.05. Insulin also increased significantly the cell proliferation in contrast to leptin, which showed no effect. In conclusion, prostate carcinoma cells seem to be influenced by factors secreted by adipocytes that are able to increase their ability to proliferate, migrate and invade.

  10. Adipocyte Triglyceride Turnover Is Independently Associated With Atherogenic Dyslipidemia

    Science.gov (United States)

    Frayn, Keith; Bernard, Samuel; Spalding, Kirsty; Arner, Peter

    2012-01-01

    Background Inappropriate storage of fatty acids as triglycerides in adipocytes and their removal from adipocytes through lipolysis and subsequent oxidation may cause the atherogenic dyslipidemia phenotype of elevated apolipoprotein B levels and subsequent hypertriglyceridemia. We tested whether turnover of triglycerides in fat cells was related to dyslipidemia. Methods and Results The age of triglycerides (reflecting removal) and triglyceride storage in adipocytes was determined under free living conditions by measuring incorporation of atmospheric 14C into these lipids within the adipocytes in 47 women and 26 men with a large interindividual variability in body mass index. Because limited 14C data were available, triglyceride age was also determined in 97 men and 233 women by using an algorithm based on adipocyte lipolysis, body fat content, waist‐to‐hip ratio, and insulin sensitivity. This cohort consisted of nonobese subjects since obesity per se is related to all components in the algorithm. Triglyceride turnover (age and storage) was compared with plasma levels of apolipoproteins and lipids. Plasma levels of apolipoprotein B and triglycerides were positively related to triglyceride age in adipocytes, when measured directly using radiocarbon analyses (r=0.45 to 0.47; PTriglyceride storage showed no independent correlation (partial r=0.02 to 0.11; P=0.42 to 0.91). Algorithm‐based values for adipocyte removal of triglycerides were positively associated with plasma triglycerides and apolipoprotein B (r=0.44 to 0.45; Ptriglycerides (as indicated by a high triglyceride age in fat cells) is independently associated with circulating apolipoprotein B and triglycerides. This suggests a hitherto unknown role of triglyceride turnover in adipocytes for the development and/or maintenance of atherogenic dyslipidemia. PMID:23316323

  11. Review on the Association between Exercise and Adipose Tissue Browning%运动与脂肪组织棕色化研究进展

    Institute of Scientific and Technical Information of China (English)

    黄涛; 李效凯

    2016-01-01

    主要探讨棕色脂肪组织和米色脂肪细胞对机体能量代谢的调控作用,以及运动对白色脂肪组织棕色化的调控作用及其潜在的分子机制。最近的研究证实,成年人体内也存在具有生理功能的棕色脂肪组织。与白色脂肪组织不同的是,棕色脂肪组织具有产生和释放热量的功能。白色脂肪组织在特定的情况下(如运动和冷环境暴露)出现可诱导的棕色脂肪细胞(即米色脂肪细胞)的过程被称为脂肪组织棕色化。米色脂肪细胞的诱导作为治疗肥胖及相关疾病的潜能受到了广泛关注。动物研究显示,运动可诱导棕色脂肪特异性基因的表达,启动白色脂肪组织棕色化的过程。这些米色脂肪细胞的分化来源并未被完全阐明。目前,仅有两项研究探讨了运动训练对人体脂肪组织棕色化的调控作用,且结果并不一致。今后的研究应该进一步验证和探讨不同运动方案对人体脂肪组织棕色化的影响及其生理学意义和机制。%This article reviewed the influences of brown adipose tissue and beige adipocytes on energy metabolism ,and also summarized the effects of exercise on adipose tissue browning and underlying molecular mechanisms .Recent studies have shown that functional brown adipose tis-sue exists in adults .Unlike white adipose tissue ,brown adipose tissue has the capability of dis-sipating chemical energy .Some conditions ,such as exercise and cold exposure ,can result in the development of inducible brown adipocytes (named beige adipocytes ) in white adipose tissue , which was named as brown tissue browning .Activation of beige adipocytes in white adipose tissue may provide a promising therapeutic target for obesity and associated diseases ,which has drawn extensive attention from researchers .Animal studies have shown that exercise can in-crease gene expressions of the brown adipocyte-specific genes in white adipose tissue

  12. A New Benchmark Brown Dwarf

    CERN Document Server

    Tinney, C G; Forveille, T; Delfosse, Xavier

    1997-01-01

    We present optical spectroscopy of three brown dwarf candidates identified in the first 1% of the DENIS sky survey. Low resolution spectra from 6430--9000A show these objects to have similar spectra to the uncertain brown dwarf candidate GD 165B. High resolution spectroscopy shows that one of the objects -- DBD 1228-1547 -- has a strong EW=2.3+-0.05A absorption line of Li I 6708A, and is therefore a brown dwarf with mass below 0.065 Msol. DBD 1228-1547 can now be the considered proto-type for objects JUST below the hydrogen burning limit.

  13. Gene expression profiles reveal effect of a high-fat diet on the development of white and brown adipose tissues.

    Science.gov (United States)

    Kim, Hyeng-Soo; Ryoo, Zae Young; Choi, Sang Un; Lee, Sanggyu

    2015-07-01

    Because of the recent discovery of brown adipose tissues tissue in adult humans, brown adipose tissues have garnered additional attention. Many studies have attempted to transform the precursor cells within the white adipocyte cultures to Brite (brown-in-white) cells by using genomic modification or pharmacological activation in order to determine the therapeutic effect of obesity. However, genome-scale analysis of the genetic factors governing the development of white and brown adipose tissues remains incomplete. In order to identify the key genes that regulate the development of white and brown adipose tissues in mice, a transcriptome analysis was performed on the adipose tissues. Network analysis of differentially expressed genes indicated that Trim30 and Ucp3 play pivotal roles in energy balance and glucose homeostasis. In addition, it was discovered that identical biological processes and pathways in the white and brown adipose tissues might be regulated by different genes. Trim30 and Ucp3 might be used as genetic markers to precisely represent the stage of obesity during the early and late stages of adipose tissue development, respectively. These results may provide a stepping-stone for future obesity-related studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. MAP kinase phosphatase 2 regulates macrophage-adipocyte interaction.

    Directory of Open Access Journals (Sweden)

    Huipeng Jiao

    Full Text Available Inflammation is critical for the development of obesity-associated metabolic disorders. This study aims to investigate the role of mitogen-activated protein kinase phosphatase 2 (MKP-2 in inflammation during macrophage-adipocyte interaction.White adipose tissues (WAT from mice either on a high-fat diet (HFD or normal chow (NC were isolated to examine the expression of MKP-2. Murine macrophage cell line RAW264.7 stably expressing MKP-2 was used to study the regulation of MKP-2 in macrophages in response to saturated free fatty acid (FFA and its role in macrophage M1/M2 activation. Macrophage-adipocyte co-culture system was employed to investigate the role of MKP-2 in regulating inflammation during adipocyte-macrophage interaction. c-Jun N-terminal kinase (JNK- and p38-specific inhibitors were used to examine the mechanisms by which MKP-2 regulates macrophage activation and macrophage-adipocytes interaction.HFD changed the expression of MKP-2 in WAT, and MKP-2 was highly expressed in the stromal vascular cells (SVCs. MKP-2 inhibited the production of proinflammatory cytokines in response to FFA stimulation in macrophages. MKP-2 inhibited macrophage M1 activation through JNK and p38. In addition, overexpression of MKP-2 in macrophages suppressed inflammation during macrophage-adipocyte interaction.MKP-2 is a negative regulator of macrophage M1 activation through JNK and p38 and inhibits inflammation during macrophage-adipocyte interaction.

  15. Gene-chip studies of adipogenesis-regulated microRNAs in mouse primary adipocytes and human obesity

    Directory of Open Access Journals (Sweden)

    Gallagher Iain J

    2011-03-01

    Full Text Available Abstract Background Adipose tissue abundance relies partly on the factors that regulate adipogenesis, i.e. proliferation and differentiation of adipocytes. While components of the transcriptional program that initiates adipogenesis is well-known, the importance of microRNAs in adipogenesis is less well studied. We thus set out to investigate whether miRNAs would be actively modulated during adipogenesis and obesity. Methods Several models exist to study adipogenesis in vitro, of which the cell line 3T3-L1 is the most well known, albeit not the most physiologically appropriate. Thus, as an alternative, we produced EXIQON microarray of brown and white primary murine adipocytes (prior to and following differentiation to yield global profiles of miRNAs. Results We found 65 miRNAs regulated during in vitro adipogenesis in primary adipocytes. We evaluated the similarity of our responses to those found in non-primary cell models, through literature data-mining. When comparing primary adipocyte profiles, with those of cell lines reported in the literature, we found a high degree of difference in 'adipogenesis' regulated miRNAs suggesting that the model systems may not be accurately representing adipogenesis. The expression of 10 adipogenesis-regulated miRNAs were studied using real-time qPCR and then we selected 5 miRNAs, that showed robust expression, were profiled in subcutaneous adipose tissue obtained from 20 humans with a range of body mass indices (BMI, range = 21-48, and all samples have U133+2 Affymetrix profiles provided. Of the miRNAs tested, mir-21 was robustly expressed in human adipose tissue and positively correlated with BMI (R2 = 0.49, p Conclusion In conclusion, we provide a preliminary analysis of miRNAs associated with primary cell in vitro adipogenesis and demonstrate that the inflammation-associated miRNA, mir-21 is up-regulated in subcutaneous adipose tissue in human obesity. Further, we provide a novel transcriptomics database of

  16. 7 CFR 29.3505 - Brown colors.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Brown colors. 29.3505 Section 29.3505 Agriculture... Type 95) § 29.3505 Brown colors. A group of colors ranging from a light brown to a dark brown. These colors vary from medium to low saturation and from medium to very low brillance. As used in...

  17. 7 CFR 29.2504 - Brown colors.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Brown colors. 29.2504 Section 29.2504 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2504 Brown colors. A group of colors ranging from a reddish brown to yellowish brown. These colors vary from low to medium saturation and from...

  18. Microbiota depletion promotes browning of white adipose tissue and reduces obesity.

    Science.gov (United States)

    Suárez-Zamorano, Nicolas; Fabbiano, Salvatore; Chevalier, Claire; Stojanović, Ozren; Colin, Didier J; Stevanović, Ana; Veyrat-Durebex, Christelle; Tarallo, Valentina; Rigo, Dorothée; Germain, Stéphane; Ilievska, Miroslava; Montet, Xavier; Seimbille, Yann; Hapfelmeier, Siegfried; Trajkovski, Mirko

    2015-12-01

    Brown adipose tissue (BAT) promotes a lean and healthy phenotype and improves insulin sensitivity. In response to cold or exercise, brown fat cells also emerge in the white adipose tissue (WAT; also known as beige cells), a process known as browning. Here we show that the development of functional beige fat in the inguinal subcutaneous adipose tissue (ingSAT) and perigonadal visceral adipose tissue (pgVAT) is promoted by the depletion of microbiota either by means of antibiotic treatment or in germ-free mice. This leads to improved glucose tolerance and insulin sensitivity and decreased white fat and adipocyte size in lean mice, obese leptin-deficient (ob/ob) mice and high-fat diet (HFD)-fed mice. Such metabolic improvements are mediated by eosinophil infiltration, enhanced type 2 cytokine signaling and M2 macrophage polarization in the subcutaneous white fat depots of microbiota-depleted animals. The metabolic phenotype and the browning of the subcutaneous fat are impaired by the suppression of type 2 cytokine signaling, and they are reversed by recolonization of the antibiotic-treated or germ-free mice with microbes. These results provide insight into the microbiota-fat signaling axis and beige-fat development in health and metabolic disease.

  19. Control of brown adipose tissue glucose and lipid metabolism by PPARγ

    Directory of Open Access Journals (Sweden)

    William T. Festuccia

    2011-12-01

    Full Text Available Brown adipose tissue (BAT non-shivering thermogenesis impacts energy homeostasis in rodents and humans. Mitochondrial UCP1 in brown fat cells produce heat by dissipating the energy generated by the oxidation of fatty acids and glucose. In addition to thermogenesis and despite its small relative size, sympathetically activated BAT constitutes an important glucose, fatty acid and triacylglycerol-clearing organ, and such function could potentially be used to alleviate dyslipidemias, hyperglycemia and insulin resistance. To date, chronic sympathetic innervation and PPARγ activation are the only recognized inducers of BAT recruitment. Here, we review the major differences between these two inducers of BAT recruitment in the regulation of lipolysis, fatty acid oxidation, lipid uptake and triacylglycerol synthesis, glucose uptake and de novo lipogenesis. Whereas BAT recruitment through sympathetic drive translates into functional thermogenic activity, PPARγ-mediated recruitment is associated with a reduction in sympathetic activity leading to increased lipid storage in brown adipocytes. The promising therapeutic role of brown adipose tissue in the treatment of hypertriglyceridemic and hyperglycaemic conditions are also discussed.

  20. Browning of Subcutaneous White Adipose Tissue in Humans after Severe Adrenergic Stress.

    Science.gov (United States)

    Sidossis, Labros S; Porter, Craig; Saraf, Manish K; Børsheim, Elisabet; Radhakrishnan, Ravi S; Chao, Tony; Ali, Arham; Chondronikola, Maria; Mlcak, Ronald; Finnerty, Celeste C; Hawkins, Hal K; Toliver-Kinsky, Tracy; Herndon, David N

    2015-08-01

    Since the presence of brown adipose tissue (BAT) was confirmed in adult humans, BAT has become a therapeutic target for obesity and insulin resistance. We examined whether human subcutaneous white adipose tissue (sWAT) can adopt a BAT-like phenotype using a clinical model of prolonged and severe adrenergic stress. sWAT samples were collected from severely burned and healthy individuals. A subset of burn victims were prospectively followed during their acute hospitalization. Browning of sWAT was determined by the presence of multilocular adipocytes, uncoupling protein 1 (UCP1), and increased mitochondrial density and respiratory capacity. Multilocular UCP1-positive adipocytes were found in sWAT samples from burn patients. UCP1 mRNA, mitochondrial density, and leak respiratory capacity in sWAT increased after burn trauma. Our data demonstrate that human sWAT can transform from an energy-storing to an energy-dissipating tissue, which opens new research avenues in our quest to prevent and treat obesity and its metabolic complications.

  1. [Kidney, adipose tissue, adipocytes--what's new?].

    Science.gov (United States)

    Lafontan, Max

    2011-04-01

    Increased evidence suggests that obesity-related glomerulopathy and chronic kidney diseases should be identified as isolated complications of obesity. It is questioned if the numerous adipose tissue productions could play a role in the initiation/maintenance of such kidney diseases. This review will provide a sum-up of recent advances on fat cell metabolism and adipose tissue physiology. The adipose tissue behaves as an endocrine organ with multiple activities. It is secreting hormones (leptin, adiponectin, apelin) and numerous factors with autocrine, paracrine and systemic effects. These secretions are coming from adipocytes themselves or from cells present in the stroma-vascular fraction of the adipose tissue. When expanding, the adipose tissue of the obese is infiltrated by immune cells such as macrophages and lymphocytes; the role of which is not fully clarified. An attempt will be done to delineate if alterations of lipid storage/fatty acid release or of the secretion potencies of adipose tissue could contribute to kidney lipotoxicity and other chronic kidney diseases described in the obese. Copyright © 2010 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  2. The effect of dehydroleucodine in adipocyte differentiation.

    Science.gov (United States)

    Galvis, Adriana; Marcano, Adriana; Stefancin, Chad; Villaverde, Nicole; Priestap, Horacio A; Tonn, Carlos E; Lopez, Luis A; Barbieri, Manuel A

    2011-12-05

    Dehydroleucodine (DhL) is a sesquiterpene lactone of the guaianolide group with gastric cytoprotective activity. Recent studies have also demonstrated that DhL inhibits the proliferation of vascular smooth muscle cells. In this study we examined the effect of DhL in the differentiation of 3T3-L1 preadipocytes. The addition of DhL significantly inhibited the differentiation of 3T3-L1 preadipocytes along with a significant decrease in the accumulation of lipid content by a dramatic downregulation of the expression of adipogenic-specific transcriptional factors PPARγ and C-EBPα. However, phosphorylation of AMPKα, Erk1/2 and Akt1 was not inhibited by DhL treatment. Interestingly, we also found that 11,13-dihydrodehydroleucodine, a derivative of DhL with inactivated α-methylene-γ-lactone function, also inhibited the differentiation of 3T3-L1 preadipocytes. Taken together, these data suggest that DhL has an important inhibitory effect in cellular pathways regulating adipocyte differentiation by modulating the PPARγ expression, which is known to play a pivotal role during adipogenesis. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Insulin: pancreatic secretion and adipocyte regulation.

    Science.gov (United States)

    Baumgard, L H; Hausman, G J; Sanz Fernandez, M V

    2016-01-01

    Insulin is the primary acute anabolic coordinator of nutrient partitioning. Hyperglycemia is the main stimulant of insulin secretion, but other nutrients such as specific amino acids, fatty acids, and ketoacids can potentiate pancreatic insulin release. Incretins are intestinal hormones with insulinotropic activity and are secreted in response to food ingestion, thus integrating diet chemical composition with the regulation of insulin release. In addition, prolactin is required for proper islet development, and it stimulates β-cell proliferation. Counterintuitively, bacterial components appear to signal insulin secretion. In vivo lipopolysaccharide infusion acutely increases circulating insulin, which is paradoxical as endotoxemia is a potent catabolic condition. Insulin is a potent anabolic orchestrator of nutrient partitioning, and this is particularly true in adipocytes. Insulin dictates lipid accretion in a dose-dependent manner during preadipocyte development in adipose tissue-derived stromal vascular cell culture. However, in vivo studies focused on insulin's role in regulating adipose tissue metabolism from growing, and market weight pigs are sometimes inconsistent, and this variability appears to be animal, age and depot dependent. Additionally, porcine adipose tissue synthesizes and secretes a number of adipokines (leptin, adiponectin, and so forth) that directly or indirectly influence insulin action. Therefore, because insulin has an enormous impact on agriculturally important phenotypes, it is critical to have a better understanding of how insulin homeostasis is governed.

  4. Autotaxin Is Regulated by Glucose and Insulin in Adipocytes.

    Science.gov (United States)

    D'Souza, Kenneth; Kane, Daniel A; Touaibia, Mohamed; Kershaw, Erin E; Pulinilkunnil, Thomas; Kienesberger, Petra C

    2017-04-01

    Autotaxin (ATX) is an adipokine that generates the bioactive lipid, lysophosphatidic acid. Despite recent studies implicating adipose-derived ATX in metabolic disorders including obesity and insulin resistance, the nutritional and hormonal regulation of ATX in adipocytes remains unclear. The current study examined the regulation of ATX in adipocytes by glucose and insulin and the role of ATX in adipocyte metabolism. Induction of insulin resistance in adipocytes with high glucose and insulin concentrations increased ATX secretion, whereas coincubation with the insulin sensitizer, rosiglitazone, prevented this response. Moreover, glucose independently increased ATX messenger RNA (mRNA), protein, and activity in a time- and concentration-dependent manner. Glucose also acutely upregulated secreted ATX activity in subcutaneous adipose tissue explants. Insulin elicited a biphasic response. Acute insulin stimulation increased ATX activity in a PI3Kinase-dependent and mTORC1-independent manner, whereas chronic insulin stimulation decreased ATX mRNA, protein, and activity. To examine the metabolic role of ATX in 3T3-L1 adipocytes, we incubated cells with the ATX inhibitor, PF-8380, for 24 hours. Whereas ATX inhibition increased the expression of peroxisome proliferator-activated receptor-γ and its downstream targets, insulin signaling and mitochondrial respiration were unaffected. However, ATX inhibition enhanced mitochondrial H2O2 production. Taken together, this study suggests that ATX secretion from adipocytes is differentially regulated by glucose and insulin. This study also suggests that inhibition of autocrine/paracrine ATX-lysophosphatidic acid signaling does not influence insulin signaling or mitochondrial respiration, but increases reactive oxygen species production in adipocytes. Copyright © 2017 Endocrine Society.

  5. Short-term regulation of adiponectin secretion in rat adipocytes.

    Science.gov (United States)

    Szkudelski, T; Nogowski, L; Szkudelska, K

    2011-01-01

    Adiponectin belongs to the group of biologically active substances secreted by adipocytes and referred to as adipokines. Disturbances in its secretion and/or action are thought to be involved in the pathogenesis of some metabolic diseases. However, regulation of adiponectin secretion is poorly elucidated. In the present study, short-term regulation of adiponectin secretion in primary rat adipocytes was investigated. Isolated rat adipocytes were incubated in Krebs-Ringer buffer containing 5 mM glucose and insulin alone or in the combination with epinephrine, dibutyryl-cAMP, adenosine A(1) receptor antagonist (DPCPX), palmitate, 2-bromopalmitate or inhibitor of mitochondrial electron transport (rotenone). Adipocyte exposure for 2 h to insulin (1-100 nM) significantly increased secretion of adiponectin compared with secretion observed without insulin. Furthermore, secretion of adiponectin from adipocytes incubated with glucose and insulin was reduced by 1 and 2 microM epinephrine, but not by 0.25 and 0.5 microM epinephrine. Under similar conditions, 1 and 2 mM dibutyryl-cAMP substantially diminished secretion of adiponectin, whereas 0.5 mM dibutyryl-cAMP was ineffective. Secretion of adiponectin was found to be effectively decreased by DPCPX. Moreover, adipocyte exposure to rotenone also resulted in a substantial diminution of secretory response of adipocytes incubated for 2 h with glucose and insulin. It was also demonstrated that palmitate and 2-bromopalmitate (0.06-0.5 mM) failed to affect secretion of leptin. The obtained results indicated that in short-term regulation of adiponectin secretion, insulin and epinephrine exert the opposite effects. These effects appeared as early as after 2 h of exposure. Moreover, deprivation of energy or blockade of adenosine action substantially decreased secretion of adiponectin.

  6. SIRT1 Limits Adipocyte Hyperplasia through c-Myc Inhibition.

    Science.gov (United States)

    Abdesselem, Houari; Madani, Aisha; Hani, Ahmad; Al-Noubi, Muna; Goswami, Neha; Ben Hamidane, Hisham; Billing, Anja M; Pasquier, Jennifer; Bonkowski, Michael S; Halabi, Najeeb; Dalloul, Rajaa; Sheriff, Mohamed Z; Mesaeli, Nasrin; ElRayess, Mohamed; Sinclair, David A; Graumann, Johannes; Mazloum, Nayef A

    2016-01-29

    The expansion of fat mass in the obese state is due to increased adipocyte hypertrophy and hyperplasia. The molecular mechanism that drives adipocyte hyperplasia remains unknown. The NAD(+)-dependent protein deacetylase sirtuin 1 (SIRT1), a key regulator of mammalian metabolism, maintains proper metabolic functions in many tissues, counteracting obesity. Here we report that differentiated adipocytes are hyperplastic when SIRT1 is knocked down stably in mouse 3T3-L1 preadipocytes. This phenotype is associated with dysregulated adipocyte metabolism and enhanced inflammation. We also demonstrate that SIRT1 is a key regulator of proliferation in preadipocytes. Quantitative proteomics reveal that the c-Myc pathway is altered to drive enhanced proliferation in SIRT1-silenced 3T3-L1 cells. Moreover, c-Myc is hyperacetylated, levels of p27 are reduced, and cyclin-dependent kinase 2 (CDK2) is activated upon SIRT1 reduction. Remarkably, differentiating SIRT1-silenced preadipocytes exhibit enhanced mitotic clonal expansion accompanied by reduced levels of p27 as well as elevated levels of CCAAT/enhancer-binding protein β (C/EBPβ) and c-Myc, which is also hyperacetylated. c-Myc activation and enhanced proliferation phenotype are also found to be SIRT1-dependent in proliferating mouse embryonic fibroblasts and differentiating human SW872 preadipocytes. Reducing both SIRT1 and c-Myc expression in 3T3-L1 cells simultaneously does not induce the adipocyte hyperplasia phenotype, confirming that SIRT1 controls adipocyte hyperplasia through c-Myc regulation. A better understanding of the molecular mechanisms of adipocyte hyperplasia will open new avenues toward understanding obesity.

  7. Effects and Molecular Mechanism of GST-Irisin on Lipolysis and Autocrine Function in 3T3-L1 Adipocytes.

    Directory of Open Access Journals (Sweden)

    Shanshan Gao

    Full Text Available Irisin, which was recently identified as a myokine and an adipokine, transforms white adipose tissue to brown adipose tissue and has increasingly caught the attention of the medical and scientific community. However, the signaling pathway of irisin and the molecular mechanisms responsible for the lipolysis effect remain unclear. In this study, we established an efficient system for the expression and purification of GST-irisin in Escherichia coli. The biological activity of GST-irisin was verified using the cell counting kit-8 assay and by detecting the mRNA expression of uncoupling protein 1. Our data showed that GST-irisin regulates mRNA levels of lipolysis-related genes such as adipose triglyceride lipase and hormone-sensitive lipase and proteins such as the fatty acid-binding protein 4, leading to increased secretion of glycerol and decreased lipid accumulation in 3T3-L1 adipocytes. In addition, exogenous GST-irisin can increase its autocrine function in vitro by regulating the expression of fibronectin type III domain-containing protein 5. GST-irisin could regulate glucose uptake in 3T3-L1 adipocytes. Hence, we believe that recombinant GST-irisin could promote lipolysis and its secretion in vitro and can potentially prevent obesity and related metabolic diseases.

  8. Effects and Molecular Mechanism of GST-Irisin on Lipolysis and Autocrine Function in 3T3-L1 Adipocytes.

    Science.gov (United States)

    Gao, Shanshan; Li, Fangmin; Li, Huimin; Huang, Yibing; Liu, Yu; Chen, Yuxin

    2016-01-01

    Irisin, which was recently identified as a myokine and an adipokine, transforms white adipose tissue to brown adipose tissue and has increasingly caught the attention of the medical and scientific community. However, the signaling pathway of irisin and the molecular mechanisms responsible for the lipolysis effect remain unclear. In this study, we established an efficient system for the expression and purification of GST-irisin in Escherichia coli. The biological activity of GST-irisin was verified using the cell counting kit-8 assay and by detecting the mRNA expression of uncoupling protein 1. Our data showed that GST-irisin regulates mRNA levels of lipolysis-related genes such as adipose triglyceride lipase and hormone-sensitive lipase and proteins such as the fatty acid-binding protein 4, leading to increased secretion of glycerol and decreased lipid accumulation in 3T3-L1 adipocytes. In addition, exogenous GST-irisin can increase its autocrine function in vitro by regulating the expression of fibronectin type III domain-containing protein 5. GST-irisin could regulate glucose uptake in 3T3-L1 adipocytes. Hence, we believe that recombinant GST-irisin could promote lipolysis and its secretion in vitro and can potentially prevent obesity and related metabolic diseases.

  9. PACSIN3 Overexpression Increases Adipocyte Glucose Transport through GLUT1

    Science.gov (United States)

    Roach, William; Plomann, Markus

    2007-01-01

    PACSIN family members regulate intracellular vesicle trafficking via their ability to regulate cytoskeletal rearrangement. These processes are known to be involved in trafficking of GLUT1 and GLUT4 in adipocytes. In this study PACSIN3 was observed to be the only PACSIN isoform that increases in expression during 3T3-L1 adipocyte differentiation. Overexpression of PACSIN3 in 3T3-L1 adipocytes caused an elevation of glucose uptake. Subcellular fractionation revealed that PACSIN3 overexpression elevated GLUT1 plasma membrane localization without effecting GLUT4 distribution. In agreement with this result, examination of GLUT exofacial presentation at the cell surface by photoaffinity labeling revealed significantly increased GLUT1, but not GLUT4, after overexpression of PACSIN3. These results establish a role for PACSIN3 in regulating glucose uptake in adipocytes via its preferential participation in GLUT1 trafficking. They are consistent with the proposal, which is supported by a recent study, that GLUT1, but not GLUT4, is predominantly endocytosed via the coated pit pathway in unstimulated 3T3-L1 adipocytes. PMID:17320047

  10. Adipocyte activation of cancer stem cell signaling in breast cancer

    Institute of Scientific and Technical Information of China (English)

    Benjamin; Wolfson; Gabriel; Eades; Qun; Zhou

    2015-01-01

    Signaling within the tumor microenvironment has a critical role in cancer initiation and progression. Adipocytes, one of the major components of the breast microenvironment,have been shown to provide pro-tumorigenic signals that promote cancer cell proliferation and invasiveness in vitro and tumorigenicity in vivo. Adipocyte secreted factors such as leptin and interleukin-6(IL-6) have a paracrine effect on breast cancer cells. In adipocyte-adjacent breast cancer cells, the leptin and IL-6 signaling pathways activate janus kinase 2/signal transducer and activatorof transcription 5, promoting the epithelial-mesenchymal transition, and upregulating stemness regulators such as Notch, Wnt and the Sex determining region Y-box 2/octamer binding transcription factor 4/Nanog signaling axis. In this review we will summarize the major signaling pathways that regulate cancer stem cells in breast cancer and describe the effects that adipocyte secreted IL-6 and leptin have on breast cancer stem cell signaling. Finally we will introduce a new potential treatment paradigm of inhibiting the adipocyte-breast cancer cell signaling via targeting the IL-6 or leptin pathways.

  11. CD36 is important for adipocyte recruitment and affects lipolysis.

    Science.gov (United States)

    Vroegrijk, Irene O C M; van Klinken, Jan Bert; van Diepen, Janna A; van den Berg, Sjoerd A A; Febbraio, Maria; Steinbusch, Laura K M; Glatz, Jan F C; Havekes, Louis M; Voshol, Peter J; Rensen, Patrick C N; van Dijk, Ko Willems; van Harmelen, Vanessa

    2013-10-01

    The scavenger receptor CD36 facilitates the cellular uptake of long-chain fatty acids. As CD36-deficiency attenuates the development of high fat diet (HFD)-induced obesity, the role of CD36-deficiency in preadipocyte recruitment and adipocyte function was set out to characterize. Fat cell size and number were determined in gonadal, visceral, and subcutaneous adipose tissue of CD36(-/-) and WT mice after 6 weeks on HFD. Basal lipolysis and insulin-inhibited lipolysis were investigated in gonadal adipose tissue. CD36(-/-) mice showed a reduction in adipocyte size in all fat pads. Gonadal adipose tissue also showed a lower total number of adipocytes because of a lower number of very small adipocytes (diameter lipolysis, in adipose tissue from CD36(-/-) mice, cAMP levels were increased and both basal and 8-bromo-cAMP stimulated lipolysis were higher. However, insulin-mediated inhibition of lipolysis was more potent in CD36(-/-) mice. These results indicate that during fat depot expansion, CD36-deficiency negatively affects preadipocyte recruitment and that in mature adipocytes, CD36-deficiency is associated with increased basal lipolysis and insulin responsiveness. Copyright © 2013 The Obesity Society.

  12. Adipocyte pseudohypoxia suppresses lipolysis and facilitates benign adipose tissue expansion.

    Science.gov (United States)

    Michailidou, Zoi; Morton, Nicholas M; Moreno Navarrete, José Maria; West, Christopher C; Stewart, Kenneth J; Fernández-Real, José Manuel; Schofield, Christopher J; Seckl, Jonathan R; Ratcliffe, Peter J

    2015-03-01

    Prolyl hydroxylase enzymes (PHDs) sense cellular oxygen upstream of hypoxia-inducible factor (HIF) signaling, leading to HIF degradation in normoxic conditions. In this study, we demonstrate that adipose PHD2 inhibition plays a key role in the suppression of adipocyte lipolysis. Adipose Phd2 gene ablation in mice enhanced adiposity, with a parallel increase in adipose vascularization associated with reduced circulating nonesterified fatty acid levels and normal glucose homeostasis. Phd2 gene-depleted adipocytes exhibited lower basal lipolysis in normoxia and reduced β-adrenergic-stimulated lipolysis in both normoxia and hypoxia. A selective PHD inhibitor suppressed lipolysis in murine and human adipocytes in vitro and in vivo in mice. PHD2 genetic ablation and pharmacological inhibition attenuated protein levels of the key lipolytic effectors hormone-sensitive lipase and adipose triglyceride lipase (ATGL), suggesting a link between adipocyte oxygen sensing and fatty acid release. PHD2 mRNA levels correlated positively with mRNA levels of AB-hydrolase domain containing-5, an activator of ATGL, and negatively with mRNA levels of lipid droplet proteins, perilipin, and TIP47 in human subcutaneous adipose tissue. Therapeutic pseudohypoxia caused by PHD2 inhibition in adipocytes blunts lipolysis and promotes benign adipose tissue expansion and may have therapeutic applications in obesity or lipodystrophy. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  13. Effect of clenbuterol on apoptosis, adipogenesis, and lipolysis in adipocytes.

    Science.gov (United States)

    Kim, Hye-Kyeong; Della-Fera, Mary Anne; Hausman, Dorothy B; Baile, Clifton A

    2010-09-01

    Clenbuterol, a beta(2)-adrenergic receptor (beta(2)-AR) selective agonist, has been shown to decrease body fat in animals and can induce apoptosis in adipose tissue in mice. We hypothesized that direct actions of a beta-adrenergic receptor agonist on adipocytes could trigger the observed apoptotic effect. The hypothesis was inspected by investigating the direct effect of clenbuterol on apoptosis, adipogenesis, and lipolysis in vitro using the 3T3-L1 cell line and rat primary adipocytes. Cells were treated with 10(-9) to 10(-5) M clenbuterol depending on the experiments. There was no apoptotic effect of clenbuterol both in 3T3-L1 cells and rat primary adipocytes. Adipogenesis monitored by Oil Red O staining and AdipoRed assay was modestly decreased by clenbuterol treatment (p < 0.05). In fully differentiated primary adipocytes, clenbuterol increased basal lipolysis compared with the control (p < 0.01). In summary, direct stimulation of beta(2)-AR by clenbuterol does not cause apoptosis in adipocytes, despite a direct lipolytic stimulation and attenuation of adipogenesis.

  14. Evaluation of chylomicron effect on ASP production in 3T3-L1 adipocytes.

    Science.gov (United States)

    Gao, Ying; Gauvreau, Danny; Cui, Wei; Lapointe, Marc; Paglialunga, Sabina; Cianflone, Katherine

    2011-02-01

    In the past few years, there has been increasing interest in the production and physiological role of acylation-stimulating protein (ASP), identical to C3adesArg, a product of the alternative complement pathway generated through C3 cleavage. Recent studies in C3 (-/-) mice that are ASP deficient have demonstrated a role for ASP in postprandial triglyceride clearance and fat storage. The aim of the present study was to establish a cell model and sensitive ELISA assay for the evaluation of ASP production using 3T3-L1 adipocytes. 3T3-L1 preadipocytes were differentiated into adipocytes, then cultured in different media such as serum-free (SF), Dulbecco's modified Eagle's medium (DMEM)/F12 + 10% fetal calf serum (FBS), and at varying concentrations of chylomicrons and insulin + chylomicrons up to 48 h. ASP production in SF and DMEM/F12 + 10% FBS was compared. Chylomicrons stimulated ASP production in a concentration- and time-dependent manner. By contrast, chylomicron treatment had no effect on the production of C3, the precursor protein of ASP, which was constant over 48 h. Addition of insulin (100 nM) to a low-dose of chylomicrons (100 µg TG/ml) significantly increased ASP production compared with chylomicrons alone at 48 h (P ASP to C3 remained constant, indicating no change in the ratio of C3 cleaved to generate ASP. This study demonstrated that 3T3-L1 adipocyte is a useful model for the evaluation of C3 secretion and ASP production by using a sensitive mouse-specific ELISA assay. The stimulation of ASP production with chylomicrons demonstrates a physiologically relevant response, and provides a strategy for further studies on ASP production and function.

  15. Up-regulation of the complement system in subcutaneous adipocytes from nonobese, hypertriglyceridemic subjects is associated with adipocyte insulin resistance.

    Science.gov (United States)

    van Greevenbroek, M M J; Ghosh, S; van der Kallen, C J H; Brouwers, M C G J; Schalkwijk, C G; Stehouwer, C D A

    2012-12-01

    Dysfunctional adipose tissue plays an important role in the etiology of the metabolic syndrome, type 2 diabetes, and dyslipidemia. However, the molecular mechanisms underlying adipocyte dysfunction are incompletely understood. The aim of the study was to identify differentially regulated pathways in sc adipocytes of dyslipidemic subjects. Whole-genome expression profiling was conducted on sc adipocytes from a discovery group of nine marginally overweight subjects with familial combined hyperlipidemia (FCHL) and nine controls of comparable body sizes as well as two independent confirmation groups. In this study, FCHL served as a model of familial insulin resistance and dyslipidemia, in the absence of frank obesity. Functional analyses and gene set enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes or a custom pathway database identified the complement system and complement regulators as one of the top up-regulated pathways in FCHL [false discovery rate (FDR) set and with triglycerides and/or waist circumference in the confirmation groups. Complement pathway up-regulation did not appear to be driven by hypertriglyceridemia because a 40% pharmacological reduction in triglycerides did not affect complement expression. These findings point to an up-regulation of a complement-related transcriptome in sc adipocytes under metabolically stressed conditions, even in the absence of overt obesity. Such up-regulation may subsequently influence downstream processes, including macrophage infiltration into adipose tissue and adipocyte insulin resistance.

  16. Enhancement of insulin sensitivity in adipocytes by ginger.

    Science.gov (United States)

    Sekiya, Keizo; Ohtani, Atsuko; Kusano, Shuichi

    2004-01-01

    Antidiabetic and hypoglycemic drugs have been reported to enhance adipocyte differentiation of 3T3-L1 preadipocytes. We previously reported that ginseng (active constituents: ginsenosides) enhanced the differentiation [1]. In this experiment, effect of some ginger group food extracts on the adipocyte differentiation was investigated using cultured mouse 3T3-L1 preadipocytes. 3T3-L1 cells were grown as monolayer cultures at 37 degrees C in DMEM supplemented by 10% FBS under the atmosphere of 5% CO(2)-95% air. Ginger extracts were found to enhance the adipocyte differentiation. Active constituent was purified and identified as gingerol. In the gingerol-treated cells, insulin-sensitive glucose uptake was increased. It is expected that ginger enhance the insulin-sensitivity, and improve chronic disease, such as diabetes.

  17. Extra Fructose in the Growth Medium Fuels Lipogenesis of Adipocytes

    Directory of Open Access Journals (Sweden)

    Armin Robubi

    2014-01-01

    Full Text Available Fructose in excessive amounts exerts negative effects on insulin sensitivity, blood pressure, and liver metabolism. These adverse outcomes were attributed to its disturbances of key metabolic pathways in the liver. Recently, possible consequences of high fructose levels directly on adipocytes in vivo have been considered. We have cultured adipocytes in growth media containing 1 g/L fructose additionally to glucose and monitored the cells fate. Cells developed lipid vesicles much earlier with fructose and showed altered kinetics of the expression of mRNAs involved in lipogenesis and hexose uptake. Adiponectin secretion, too, peaked earlier in fructose containing media than in media with glucose only. From these data it can be speculated that similar effects of fructose containing diets happen in vivo also. Apart from toxic action on liver cells, adipocytes might be stimulated to take up extra fructose and generate new lipid vesicles, further dysregulating energy homeostasis.

  18. The biological clock is regulated by adrenergic signaling in brown fat but is dispensable for cold-induced thermogenesis.

    Directory of Open Access Journals (Sweden)

    Siming Li

    Full Text Available The biological clock plays an important role in integrating nutrient and energy metabolism with other cellular processes. Previous studies have demonstrated that core clock genes are rhythmically expressed in peripheral tissues, including the liver, skeletal muscle, pancreatic islets, and white and brown adipose tissues. These peripheral clocks are entrained by physiological cues, thereby aligning the circadian pacemaker to tissue functions. The mechanisms that regulate brown adipose tissue clock in response to physiological signals remain poorly understood. Here we found that the expression of core clock genes is highly responsive to cold exposure in brown fat, but not in white fat. This cold-inducible regulation of the clock network is mediated by adrenergic receptor activation and the transcriptional coactivator PGC-1α. Brown adipocytes in mice lacking a functional clock contain large lipid droplets accompanied by dysregulation of genes involved in lipid metabolism and adaptive thermogenesis. Paradoxically, the "clockless" mice were competent in maintaining core body temperature during cold exposure. These studies elucidated the presence of adrenergic receptor/clock crosstalk that appears to be required for normal thermogenic gene expression in brown fat.

  19. The rotation of brown dwarfs

    CERN Document Server

    Scholz, Aleks

    2016-01-01

    One of the characteristic features of low-mass stars is their propensity to shed large amounts of angular momentum throughout their evolution. This distinguishs them from brown dwarfs which remain fast rotators over timescales of gigayears. Brown dwarfs with rotation periods longer than a couple of days have only been found in star forming regions and young clusters. This is a useful constraint on the mass dependency of mechanisms for angular momentum regular in stars. Rotational braking by disks and winds become highly inefficient in the substellar regime. In this short review I discuss the observational evidence for the fast rotation in brown dwarfs, the implications, and the link to the spin-mass relation in planets.

  20. Lipid droplets hypertrophy: A crucial determining factor in insulin regulation by adipocytes

    NARCIS (Netherlands)

    B. Sanjabi (B.); M. Dashty (Monireh); B. Özcan (Behiye); V. Akbarkhanzadeh (Vishtaseb); M. Rahimi (Mehran); M. Vinciguerra (Manlio); F. Van Rooij (Felix); S.H. Al-Lahhman (Sa'ad); F. Sheedfar (Fareeba); T.G. Van Kooten (Theo G.); C.A. Spek (Arnold); A.T. Rowshani (Ajda); J.J.L. van der Want (Johannes); R. Klaassen (Rene); E.J.G. Sijbrands (Eric); M.P. Peppelenbosch (Maikel); F. Rezaee (Farhad)

    2015-01-01

    textabstractLipid droplets (LDs) hypertrophy in adipocytes is the main cause of energy metabolic system dysfunction, obesity and its afflictions such as T2D. However, the role of adipocytes in linking energy metabolic disorders with insulin regulation is unknown in humans. Human adipocytes constitut

  1. Transcriptional regulatory program in wild-type and retinoblastoma gene-deficient mouse embryonic fibroblasts during adipocyte differentiation

    Directory of Open Access Journals (Sweden)

    Hansen Jacob B

    2011-05-01

    Full Text Available Abstract Background Although many molecular regulators of adipogenesis have been identified a comprehensive catalogue of components is still missing. Recent studies showed that the retinoblastoma protein (pRb was expressed in the cell cycle and late cellular differentiation phase during adipogenesis. To investigate this dual role of pRb in the early and late stages of adipogenesis we used microarrays to perform a comprehensive systems-level analysis of the common transcriptional program of the classic 3T3-L1 preadipocyte cell line, wild-type mouse embryonic fibroblasts (MEFs, and retinoblastoma gene-deficient MEFs (Rb-/- MEFs. Findings Comparative analysis of the expression profiles of 3T3-L1 cells and wild-type MEFs revealed genes involved specifically in early regulation of the adipocyte differentiation as well as secreted factors and signaling molecules regulating the later phase of differentiation. In an attempt to identify transcription factors regulating adipogenesis, bioinformatics analysis of the promoters of coordinately and highly expressed genes was performed. We were able to identify a number of high-confidence target genes for follow-up experimental studies. Additionally, combination of experimental data and computational analyses pinpointed a feedback-loop between Pparg and Foxo1. To analyze the effects of the retinoblastoma protein at the transcriptional level we chose a perturbated system (Rb-/- MEFs for comparison to the transcriptional program of wild-type MEFs. Gene ontology analysis of 64 deregulated genes showed that the Rb-/- MEF model exhibits a brown(-like adipocyte phenotype. Additionally, the analysis results indicate a different or additional role for pRb family member involvement in the lineage commitment. Conclusion In this study a number of commonly modulated genes during adipogenesis in 3T3-L1 cells and MEFs, potential transcriptional regulation mechanisms, and differentially regulated targets during adipocyte

  2. The Dietary Isoflavone Daidzein Reduces Expression of Pro-Inflammatory Genes through PPARα/γ and JNK Pathways in Adipocyte and Macrophage Co-Cultures.

    Directory of Open Access Journals (Sweden)

    Yuri Sakamoto

    Full Text Available Obesity-induced inflammation caused by adipocyte-macrophage interactions plays a critical role in developing insulin resistance, and peroxisome proliferator-activated receptors (PPARs regulate inflammatory gene expression in these cells. Recently, the soy isoflavone daidzein was reported to act as a PPAR activator. We examined whether daidzein affected adipocyte-macrophage crosstalk via the regulation of PPARs. Co-cultures of 3T3-L1 adipocytes and RAW264 macrophages, or palmitate-stimulated RAW264 macrophages were treated with daidzein in the presence or absence of specific inhibitors for PPARs: GW6471 (a PPARα antagonist, and GW9662 (a PPARγ antagonist. Inflammatory gene expression was then determined. Daidzein significantly decreased chemokine (C-C motif ligand 2 (Ccl2, known in humans as monocyte chemo-attractant protein 1 (MCP1 and interleukin 6 (Il6 mRNA levels induced by co-culture. In 3T3-L1 adipocytes, daidzein inversed the attenuation of adiponectin gene expression by co-culture, and these effects were inhibited by the PPAR-γ specific inhibitor. Daidzein also decreased Ccl2 and Il6 mRNA levels in RAW264 macrophages stimulated with palmitate or conditioned medium (CM from hypertrophied 3T3-L1 adipocytes. This inhibitory effect on Il6 expression was abrogated by a PPAR-α inhibitor. Additionally, we examined the activation of nuclear factor-kappa B (NF-κB and c-Jun N-terminal kinase (JNK pathways and found that daidzein significantly inhibited palmitate-induced phosphorylation of JNK. Our data suggest that daidzein regulates pro-inflammatory gene expression by activating PPAR-α and -γ and inhibiting the JNK pathway in adipocyte and macrophage co-cultures. These effects might be favorable in improving adipose inflammation, thus, treatment of daidzein may be a therapeutic strategy for chronic inflammation in obese adipose tissue.

  3. Salt-inducible kinase 2 and -3 are downregulated in adipose tissue from obese or insulin-resistant individuals: implications for insulin signalling and glucose uptake in human adipocytes.

    Science.gov (United States)

    Säll, Johanna; Pettersson, Annie M L; Björk, Christel; Henriksson, Emma; Wasserstrom, Sebastian; Linder, Wilhelm; Zhou, Yuedan; Hansson, Ola; Andersson, Daniel P; Ekelund, Mikael; Degerman, Eva; Stenkula, Karin G; Laurencikiene, Jurga; Göransson, Olga

    2017-02-01

    Salt-inducible kinases (SIKs) are related to the metabolic regulator AMP-activated protein kinase (AMPK). SIK2 is abundant in adipose tissue. The aims of this study were to investigate the expression of SIKs in relation to human obesity and insulin resistance, and to evaluate whether changes in the expression of SIKs might play a causal role in the development of disturbed glucose uptake in human adipocytes. SIK mRNA and protein was determined in human adipose tissue or adipocytes, and correlated to clinical variables. SIK2 and SIK3 expression and phosphorylation were analysed in adipocytes treated with TNF-α. Glucose uptake, GLUT protein levels and localisation, phosphorylation of protein kinase B (PKB/Akt) and the SIK substrate histone deacetylase 4 (HDAC4) were analysed after the SIKs had been silenced using small interfering RNA (siRNA) or inhibited using a pan-SIK-inhibitor (HG-9-91-01). We demonstrate that SIK2 and SIK3 mRNA are downregulated in adipose tissue from obese individuals and that the expression is regulated by weight change. SIK2 is also negatively associated with in vivo insulin resistance (HOMA-IR), independently of BMI and age. Moreover, SIK2 protein levels and specific kinase activity display a negative correlation to BMI in human adipocytes. Furthermore, SIK2 and SIK3 are downregulated by TNF-α in adipocytes. Silencing or inhibiting SIK1-3 in adipocytes results in reduced phosphorylation of HDAC4 and PKB/Akt, less GLUT4 at the plasma membrane, and lower basal and insulin-stimulated glucose uptake in adipocytes. This is the first study to describe the expression and function of SIKs in human adipocytes. Our data suggest that SIKs might be protective in the development of obesity-induced insulin resistance, with implications for future treatment strategies.

  4. Live-trapping and handling brown bear

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This paper reports techniques developed to live trap and handle brown bears on the Kodiak National Wildlife Refuge. The brown bears (Ursus middendorffi) on the...

  5. Browns Park NWR Water Use Report- 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Browns Park NWR for 1999. A basic introduction highlighting the region that Browns Park NWR is a part of and the...

  6. Browns Park NWR Water Use Report- 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Browns Park NWR for 1985. Data for each diversion/impoundment at Browns Park NWR is supplied. This data includes the...

  7. Browns Park NWR Water Use Report- 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Browns Park NWR for 1987. Data for each diversion/impoundment at Browns Park NWR is supplied. This data includes the...

  8. Browns Park NWR Water Use Report- 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Browns Park NWR for 1984. Data for each diversion/impoundment at Browns Park NWR is supplied. This data includes the...

  9. Browns Park NWR Water Use Report- 1980

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Browns Park NWR for 1980. Data for each diversion/impoundment at Browns Park NWR is supplied. This data includes the...

  10. Browns Park NWR Water Use Report- 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Browns Park NWR for 2000. A basic introduction highlighting the region that Browns Park NWR is a part of and the...

  11. Browns Park NWR Water Use Report- 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Browns Park NWR for 1986. Data for each diversion/impoundment at Browns Park NWR is supplied. This data includes the...

  12. Estrogen-related receptor alpha modulates the expression of adipogenesis-related genes during adipocyte differentiation.

    Science.gov (United States)

    Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Yagi, Ken; Okazaki, Yasushi; Inoue, Satoshi

    2007-07-06

    Estrogen-related receptor alpha (ERRalpha) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in fatty acid oxidation and mitochondrial biogenesis in brown adipose tissue. However, the physiological role of ERRalpha in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERRalpha and ERRalpha-related transcriptional coactivators, peroxisome proliferator-activated receptor gamma (PPARgamma) coactivator-1alpha (PGC-1alpha) and PGC-1beta, can be up-regulated in 3T3-L1 preadipocytes at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. Gene knockdown by ERRalpha-specific siRNA results in mRNA down-regulation of fatty acid binding protein 4, PPARgamma, and PGC-1alpha in 3T3-L1 cells in the adipogenesis medium. ERRalpha and PGC-1beta mRNA expression can be also up-regulated in another preadipocyte lineage DFAT-D1 cells and a pluripotent mesenchymal cell line C3H10T1/2 under the differentiation condition. Furthermore, stable expression of ERRalpha in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERRalpha may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes.

  13. Characterization of age-related gene expression profiling in bone marrow and epididymal adipocytes

    Directory of Open Access Journals (Sweden)

    Ueno Masami

    2011-05-01

    Full Text Available Abstract Background While an increase in bone marrow adiposity is associated with age-related bone disease, the function of bone marrow adipocytes has not been studied. The aim of this study was to characterize and compare the age-related gene expression profiles in bone marrow adipocytes and epididymal adipocytes. Results A total of 3918 (13.7% genes were differentially expressed in bone marrow adipocytes compared to epididymal adipocytes. Bone marrow adipocytes revealed a distinct gene profile with low expression of adipocyte-specific genes peroxisome proliferator-activated receptor gamma (PPARγ, fatty acid binding protein 4 (FABP4, perilipin (Plin1, adipsin (CFD and high expression of genes associated with early adipocyte differentiation (CCAAT/enhancer binding protein beta (C/EBPβ, regulator of G-protein signaling 2 (RGS2. In addition, a number of genes including secreted frizzled related protein 4 (SFRP4, tumor necrosis factor α (TNFα, transforming growth factor beta 1(TGFβ1, G-protein coupled receptor 109A (GPR109A and interleukin 6 (IL-6, that could affect adipose-derived signaling to bone are markedly increased in bone marrow adipocytes. Age had a substantial effect on genes associated with mitochondria function and inflammation in bone marrow adipocytes. Twenty seven genes were significantly changed with age in both adipocyte depots. Among these genes, IL6 and GPR109A were significantly reduced with age in both adipocyte depots. Conclusions Overall, gene profiling reveals a unique phenotype for primary bone marrow adipocytes characterized by low adipose-specific gene expression and high expression of inflammatory response genes. Bone marrow and epididymal adipocytes share a common pathway in response to aging in mice, but age has a greater impact on global gene expression in epididymal than in bone marrow adipocytes. Genes that are differentially expressed at greater levels in the bone marrow are highly regulated with age.

  14. α-Naphthoflavone Increases Lipid Accumulation in Mature Adipocytes and Enhances Adipocyte-Stimulated Endothelial Tube Formation

    Directory of Open Access Journals (Sweden)

    Mei-Lin Wang

    2015-04-01

    Full Text Available The aryl hydrocarbon receptor (AhR is a ligand-activated factor that regulates biological effects associated with obesity. The AhR agonists, such as environmental contaminants 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD and β-naphthoflavone (BNF, inhibit preadipocyte differentiation and interfere with the functions of adipose tissue, whereas the antagonist may have opposite or protective effects in obesity. This study investigated the effects of α-naphthoflavone (α-NF, an AhR antagonist, on adipogenesis- and angiogenesis-associated factors in mature adipocytes and on cross-talk of mature adipocytes with endothelial cells (ECs. Besides, the roles of the AhR on lipid accumulation and on secretion of vascular endothelial growth factor were also determined by introducing siRNA of AhR. Differentiated 3T3-L1 cells were treated with α-naphthoflavone (α-NF (1–5 μM for 16 h. Lipid accumulation and the expressions of AhR-associated factors in the cells were determined. The interaction between adipocytes and ECs was investigated by cultivating ECs with conditioned medium (CM from α-NF-treated mature adipocytes, followed by the determination of endothelial tube formation. The results showed that α-NF significantly increased triglyceride (TG accumulation in mature adipocytes, which was associated with increased expression of hormone-sensitive lipase (HSL, estrogen receptor (ER, as well as decreased expression of AhR, AhR nuclear translocator (ARNT, cytochrome P4501B1 (CYP1B1, and nuclear factor erythroid-2-related factor (NRF-2 proteins. In addition, CM stimulated formation of tube-like structures in ECs, and α-NF further enhanced such stimulation in association with modulated the secretions of various angiogenic mediators by mature adipocytes. Similarly, increased TG accumulation and vascular endothelial growth factor (VEGF secretion were observed in AhR-knockout cells. In conclusion, α-NF increased TG accumulation in mature adipocytes and

  15. Cell Biology Symposium: imaging the organization and trafficking of lipolytic effectors in adipocytes.

    Science.gov (United States)

    Granneman, J G; Kimler, V A; Moore, H-P H

    2011-03-01

    The storage and mobilization of lipid energy are central functions of adipocytes. Lipid energy is stored as triglyceride in lipid droplet structures that are now recognized as bona fide organelles and whose functions are greatly influenced by members of the perilipin family of lipid droplet scaffolds. Recent work indicates that the signaling events underlying fatty acid mobilization involve protein trafficking to a specialized subset of lipid droplets. Furthermore, the core lipolytic machinery is composed of evolutionarily conserved proteins whose functions are conserved in avian and mammalian production species. Lipolysis affects many aspects of animal nutrition and physiology, which can have an important influence on growth efficiency, lactation, and meat quality. This review focuses on recent research that addresses the organization and trafficking of key players in hormone-stimulated lipolysis, and the central role of perilipin1A in adipocyte lipolysis. The review emphasizes recent work from the laboratories of the authors that utilizes imaging techniques to explore the organization and interactions among lipolytic effectors in live cells during lipolytic activation. A mechanistic understanding of lipolysis may lead to new strategies for promoting human and animal health.

  16. 21 CFR 184.1120 - Brown algae.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Brown algae. 184.1120 Section 184.1120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1120 Brown algae. (a) Brown algae are seaweeds of the species Analipus...

  17. 7 CFR 29.2254 - Brown colors.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Brown colors. 29.2254 Section 29.2254 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... colors. A group of colors ranging from a reddish brown to yellowish brown. These colors vary from low...

  18. Beth Starts Like Brown Bear!

    Science.gov (United States)

    Fawcett, Gay

    1994-01-01

    Recounts a reading teacher's illuminating experience with a first grader who enjoyed reading Bill Martin's "Brown Bear" books, despite being labeled as dyslexic. Dyslexia is an elusive condition that is biological in origin and distinct from other reading problems. New research shows that reading difficulties, including dyslexia, occur as part of…

  19. Tune Your Brown Clustering, Please

    DEFF Research Database (Denmark)

    Derczynski, Leon; Chester, Sean; Bøgh, Kenneth Sejdenfaden

    2015-01-01

    explore the dynamic between the input corpus size, chosen number of classes, and quality of the resulting clusters, which has an impact for any approach using Brown clustering. In every scenario that we examine, our results reveal that the values most commonly used for the clustering are sub-optimal....

  20. Direct activating effects of adrenocorticotropic hormone (ACTH) on brown adipose tissue are attenuated by corticosterone.

    Science.gov (United States)

    van den Beukel, Johanna C; Grefhorst, Aldo; Quarta, Carmelo; Steenbergen, Jacobie; Mastroberardino, Pier G; Lombès, Marc; Delhanty, Patric J; Mazza, Roberta; Pagotto, Uberto; van der Lely, Aart Jan; Themmen, Axel P N

    2014-11-01

    Brown adipose tissue (BAT) and brown-like cells in white adipose tissue (WAT) can dissipate energy through thermogenesis, a process mediated by uncoupling protein 1 (UCP1). We investigated whether stress hormones ACTH and corticosterone contribute to BAT activation and browning of WAT. ACTH and corticosterone were studied in male mice exposed to 4 or 23°C for 24 h. Direct effects were studied in T37i mouse brown adipocytes and primary cultured murine BAT and inguinal WAT (iWAT) cells. In vivo effects were studied using (18)F-deoxyglucose positron emission tomography. Cold exposure doubled serum ACTH concentrations (P=0.03) and fecal corticosterone excretion (P=0.008). In T37i cells, ACTH dose-dependently increased Ucp1 mRNA (EC50=1.8 nM) but also induced Ucp1 protein content 88% (P=0.02), glycerol release 32% (P=0.03) and uncoupled respiration 40% (P=0.003). In cultured BAT and iWAT, ACTH elevated Ucp1 mRNA by 3-fold (P=0.03) and 3.7-fold (P=0.01), respectively. In T37i cells, corticosterone prevented induction of Ucp1 mRNA and Ucp1 protein by both ACTH and norepinephrine in a glucocorticoid receptor (GR)-dependent fashion. ACTH and GR antagonist RU486 independently doubled BAT (18)F-deoxyglucose uptake (P=0.0003 and P=0.004, respectively) in vivo. Our results show that ACTH activates BAT and browning of WAT while corticosterone counteracts this. © FASEB.