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Sample records for human adipocyte delipidation

  1. Delipidation of Plasma Has Minimal Effects on Human Butyrylcholinesterase

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    Seda Onder

    2018-02-01

    Full Text Available Human butyrylcholinesterase (BChE is purified in large quantities from Cohn fraction IV-4 to use for protection against the toxicity of chemical warfare agents. Small scale preliminary experiments use outdated plasma from the American Red Cross as the starting material for purifying BChE (P06276. Many of the volunteer donor plasma samples are turbid with fat, the donor having eaten fatty food before the blood draw. The turbid fat interferes with enzyme assays performed in the spectrophotometer and with column chromatography. Our goal was to find a method to remove fat from plasma without loss of BChE activity. Satisfactory delipidation was achieved by adding a solution of 10% dextran sulfate and calcium chloride to fatty plasma, followed by centrifugation, and filtration through a 0.8 μm filter. Treatment with Aerosil also delipidated fatty plasma, but was accompanied by loss of 50% of the plasma volume. BChE activity and the BChE isozyme pattern on nondenaturing gel electrophoresis were unaffected by delipidation. BChE in delipidated plasma was efficiently captured by immobilized monoclonal antibodies B2 18-5 and mAb2. The immunopurified BChE was released from antibody binding with acid and visualized as a highly enriched, denatured BChE preparation by SDS gel electrophoresis. In conclusion, delipidation with dextran sulfate/CaCl2 preserves BChE activity and the tetramer structure of BChE.

  2. Phenolic compounds apigenin, hesperidin and kaempferol reduce in vitro lipid accumulation in human adipocytes.

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    Gómez-Zorita, Saioa; Lasa, Arrate; Abendaño, Naiara; Fernández-Quintela, Alfredo; Mosqueda-Solís, Andrea; Garcia-Sobreviela, Maria Pilar; Arbonés-Mainar, Jose M; Portillo, Maria P

    2017-11-21

    Adipocytes derived from human mesenchymal stem cells (MSCs) are widely used to investigate adipogenesis. Taking into account both the novelty of these MSCs and the scarcity of studies focused on the effects of phenolic compounds, the aim of the present study was to analyze the effect of apigenin, hesperidin and kaempferol on pre-adipocyte and mature adipocytes derived from this type of cells. In addition, the expression of genes involved in TG accumulation was also measured. Pre-adipocytes were cultured from day 0 to day 8 and mature adipocytes for 48 h with the polyphenols at doses of 1, 10 and 25 µM. Apigenin did not show an anti-adipogenic action. Pre-adipocytes treated with hesperidin and kaempferol showed reduced TG content at the three experimental doses. Apigenin did not modify the expression of the main adipogenic genes (c/ebpβ, c/ebpα, pparγ and srebp1c), hesperidin inhibited genes involved in the three phases of adipogenesis (c/ebpβ, srebp1c and perilipin) and kaempferol reduced c/ebpβ. In mature adipocytes, the three polyphenols reduced TG accumulation at the dose of 25 µM, but not at lower doses. All compounds increased mRNA levels of atgl. Apigenin and hesperidin decreased fasn expression. The present study shows the anti-adipogenic effect and delipidating effects of apigenin, hesperidin and kaempferol in human adipocytes derived from hMSCs. While hesperidin blocks all the stages of adipogenesis, kaempferol only inhibits the early stage. Regarding mature adipocytes, the three compounds reduce TG accumulation by activating, at least in part, lipolysis, and in the case of hesperidin and apigenin, also by reducing lipogenesis. The present study shows for the first time the anti-adipogenic effect and delipidating effect of apigenin, hesperidin and kaempferol in human adipocytes derived from MSCs for the first time.

  3. Pro-inflammatory delipidizing cytokines reduce adiponectin secretion from human adipocytes without affecting adiponectin oligomerization

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    Simons, Peter J.; van den Pangaart, Petra S.; Aerts, Johannes M. F. G.; Boon, Louis

    2007-01-01

    Adiponectin and, especially, its oligomeric complex composition have been suggested to be critical in determining insulin sensitivity. Pro-inflammatory cytokines play an important role in the development of insulin resistance in obesity and associated diseases. Therefore, we investigated the effect

  4. Dynamics of Adipocyte Turnover in Humans

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    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.

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

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    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.

  6. Conjugated linoleic acid induces human adipocyte delipidation: autocrine/paracrine regulation of MEK/ERK signaling by adipocytokines

    DEFF Research Database (Denmark)

    Brown, J Mark; Boysen, Maria Sandberg; Chung, Soonkyu

    2004-01-01

    of MEK/ERK could be attenuated by pretreatment with U0126 and pertussis toxin. In parallel, pretreatment with U0126 blocked the ability of trans-10, cis-12 CLA to alter gene expression and attenuate glucose and fatty acid uptake of the cultures. Intriguingly, the induction by CLA of MEK/ERK signaling...

  7. Persistent organic pollutants alter DNA methylation during human adipocyte differentiation

    NARCIS (Netherlands)

    Dungen, van den Myrthe W.; Murk, Albertinka J.; Gils-Kok, van Dieuwertje; Steegenga, Wilma T.

    2017-01-01

    Ubiquitous persistent organic pollutants (POPs) can accumulate in humans where they might influence differentiation of adipocytes. The aim of this study was to investigate whether DNA methylation is one of the underlying mechanisms by which POPs affect adipocyte differentiation, and to what

  8. Staphylococcal superantigens stimulate immortalized human adipocytes to produce chemokines.

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    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

  9. Clozapine modifies the differentiation program of human adipocytes inducing browning.

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    Kristóf, E; Doan-Xuan, Q-M; Sárvári, A K; Klusóczki, Á; Fischer-Posovszky, P; Wabitsch, M; Bacso, Z; Bai, P; Balajthy, Z; Fésüs, L

    2016-11-29

    Administration of second-generation antipsychotic drugs (SGAs) often leads to weight gain and consequent cardio-metabolic side effects. We observed that clozapine but not six other antipsychotic drugs reprogrammed the gene expression pattern of differentiating human adipocytes ex vivo, leading to an elevated expression of the browning marker gene UCP1, more and smaller lipid droplets and more mitochondrial DNA than in the untreated white adipocytes. Laser scanning cytometry showed that up to 40% of the differentiating single primary and Simpson-Golabi-Behmel syndrome (SGBS) adipocytes had the characteristic morphological features of browning cells. Furthermore, clozapine significantly upregulated ELOVL3, CIDEA, CYC1, PGC1A and TBX1 genes but not ZIC1 suggesting induction of the beige-like and not the classical brown phenotype. When we tested whether browning induced by clozapine can be explained by its known pharmacological effect of antagonizing serotonin (5HT) receptors, it was found that browning cells expressed 5HT receptors 2A, 1D, 7 and the upregulation of browning markers was diminished in the presence of exogenous 5HT. Undifferentiated progenitors or completely differentiated beige or white adipocytes did not respond to clozapine administration. The clozapine-induced beige cells displayed increased basal and oligomycin-inhibited (proton leak) oxygen consumption, but these cells showed a lower response to cAMP stimulus as compared with control beige adipocytes indicating that they are less capable to respond to natural thermogenic anti-obesity cues. Our data altogether suggest that novel pharmacological stimulation of these masked beige adipocytes can be a future therapeutic target for the treatment of SGA-induced weight gain.

  10. Brown and beige fat in humans: thermogenic adipocytes that control energy and glucose homeostasis.

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    Sidossis, Labros; Kajimura, Shingo

    2015-02-01

    Brown adipose tissue (BAT), a specialized fat that dissipates energy to produce heat, plays an important role in the regulation of energy balance. Two types of thermogenic adipocytes with distinct developmental and anatomical features exist in rodents and humans: classical brown adipocytes and beige (also referred to as brite) adipocytes. While classical brown adipocytes are located mainly in dedicated BAT depots of rodents and infants, beige adipocytes sporadically reside with white adipocytes and emerge in response to certain environmental cues, such as chronic cold exposure, a process often referred to as "browning" of white adipose tissue. Recent studies indicate the existence of beige adipocytes in adult humans, making this cell type an attractive therapeutic target for obesity and obesity-related diseases, including type 2 diabetes. This Review aims to cover recent progress in our understanding of the anatomical, developmental, and functional characteristics of brown and beige adipocytes and discuss emerging questions, with a special emphasis on adult human BAT.

  11. Activation of peroxisome proliferator-activated receptor-α enhances fatty acid oxidation in human adipocytes

    International Nuclear Information System (INIS)

    Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi; Sakamoto, Tomoya; Takahashi, Nobuyuki; Kawada, Teruo

    2011-01-01

    Highlights: → PPARα activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. → PPARα activation also increased insulin-dependent glucose uptake in human adipocytes. → PPARα activation did not affect lipid accumulation in human adipocytes. → PPARα activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-α (PPARα) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPARα in adipocytes have been unclarified. We examined the functions of PPARα using human multipotent adipose tissue-derived stem cells as a human adipocyte model. Activation of PPARα by GW7647, a potent PPARα agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPARγ, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPARα activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPARγ is activated. On the other hand, PPARα activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPARα-dependent manner. Moreover, PPARα activation increased the production of CO 2 and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPARα stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPARα agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected effects of PPARα activation are very valuable for managing diabetic conditions accompanied by obesity, because

  12. Characterization of lipid metabolism in insulin-sensitive adipocytes differentiated from immortalized human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Prawitt, Janne; Niemeier, Andreas; Kassem, Moustapha

    2008-01-01

    There is a great demand for cell models to study human adipocyte function. Here we describe the adipogenic differentiation of a telomerase-immortalized human mesenchymal stem cell line (hMSC-Tert) that maintains numerous features of terminally differentiated adipocytes even after prolonged...

  13. The Therapeutic Potential of Brown Adipocytes in Humans

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    Craig ePorter

    2015-10-01

    Full Text Available Obesity and its metabolic consequences represent a significant clinical problem. From a thermodynamic standpoint, obesity results from a discord in energy intake and expenditure. To date, lifestyle interventions based on reducing energy intake and/or increasing energy expenditure have proved ineffective in the prevention and treatment of obesity, owing to poor long-term adherence to such interventions. Thus, an effective strategy to prevent or correct obesity is currently lacking.As the combustion engines of our cells, mitochondria play a critical role in energy expenditure. At a whole body level, approximately 80% of mitochondrial membrane potential generated by fuel oxidation is used to produce ATP, and the remaining 20% is lost through heat-producing uncoupling reactions. The coupling of mitochondrial respiration to ATP production represents an important component in whole body energy expenditure. Brown adipose tissue (BAT is densely populated with mitochondria containing the inner mitochondrial proton carrier uncoupling protein 1 (UCP. UCP1 uncouples oxidative phosphorylation, meaning that mitochondrial membrane potential is dissipated as heat. The recent re-discovery of BAT depots in adult humans has rekindled scientific interest in the manipulation of mitochondrial uncoupling reactions as a means to increase metabolic rate, thereby counteracting obesity and its associated metabolic phenotype. In this article, we discuss the evidence for the role BAT plays in metabolic rate and glucose and lipid metabolism in humans, and the potential for UCP1 recruitment in the white adipose tissue of humans. While the future holds much promise for a therapeutic role of UCP1 expressing adipocytes in human energy metabolism, particularly in the context of obesity, tissue specific strategies that activate or recruit UCP1 in human adipocytes represent an obligatory translation step for this early promise to be realized.

  14. Activation of peroxisome proliferator-activated receptor-{alpha} enhances fatty acid oxidation in human adipocytes

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    Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi; Sakamoto, Tomoya; Takahashi, Nobuyuki [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan); Kawada, Teruo, E-mail: fat@kais.kyoto-u.ac.jp [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2011-04-22

    Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. {yields} PPAR{alpha} activation also increased insulin-dependent glucose uptake in human adipocytes. {yields} PPAR{alpha} activation did not affect lipid accumulation in human adipocytes. {yields} PPAR{alpha} activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPAR{alpha} in adipocytes have been unclarified. We examined the functions of PPAR{alpha} using human multipotent adipose tissue-derived stem cells as a human adipocyte model. Activation of PPAR{alpha} by GW7647, a potent PPAR{alpha} agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPAR{gamma}, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPAR{alpha} activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPAR{gamma} is activated. On the other hand, PPAR{alpha} activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPAR{alpha}-dependent manner. Moreover, PPAR{alpha} activation increased the production of CO{sub 2} and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPAR{alpha} stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPAR{alpha} agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected

  15. TBTC induces adipocyte differentiation in human bone marrow long term culture

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    Carfi, M.; Croera, C.; Ferrario, D.; Campi, V.; Bowe, G.; Pieters, R.; Gribaldo, L.

    2008-01-01

    Organotins are widely used in agriculture and the chemical industry, causing persistent and widespread pollution. Organotins may affect the brain, liver and immune system and eventually human health. Recently, it has been shown that tri-butyltin (TBT) interacts with nuclear receptors PPARγ (peroxisome proliferator-activated receptor γ) and RXR (retinoid x receptor) leading to adipocyte differentiation in the 3T3 cell line. Since adipocytes are known to influence haematopoiesis, for instance through the expression of cytokines and adhesion molecules, it was considered of interest to further study the adipocyte-stimulating effect of TBTC in human bone marrow cultures. Nile Red spectrofluorimetric analysis showed a significant increase of adipocytes in TBTC-treated cultures after 14 days of long term culture. Real-time PCR and Western blot analysis confirmed the high expression of the specific adipocyte differentiation marker aP2 (adipocyte-specific fatty acid binding protein). PPARγ, but not RXR, mRNA was increased after 24 h and 48 h exposure. TBTC also induced a decrease in a number of chemokines, interleukins, and growth factors. Also the expression of leptin, a hormone involved in haematopoiesis, was down regulated by TBTC treatment. It therefore appears that TBTC induced adipocyte differentiation, whilst reducing a number of haematopoietic factors. This study indicates that TBTC may interfere in the haematopoietic process through an alteration of the stromal layer and cytokine homeostasis

  16. microRNA-320/RUNX2 axis regulates adipocytic differentiation of human mesenchymal (skeletal) stem cells

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    Hamam, D; Ali, D; Vishnubalaji, R

    2014-01-01

    The molecular mechanisms promoting lineage-specific commitment of human mesenchymal (skeletal or stromal) stem cells (hMSCs) into adipocytes (ADs) are not fully understood. Thus, we performed global microRNA (miRNA) and gene expression profiling during adipocytic differentiation of h...... differentiation and accelerated formation of mature ADs in ex vivo cultures. Integrated analysis of bioinformatics and global gene expression profiling in miR-320c overexpressing cells and during adipocytic differentiation of hMSC identified several biologically relevant gene targets for miR-320c including RUNX2...

  17. Establishment of lipofection for studying miRNA function in human adipocytes.

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    Enlund, Eveliina; Fischer, Simon; Handrick, René; Otte, Kerstin; Debatin, Klaus-Michael; Wabitsch, Martin; Fischer-Posovszky, Pamela

    2014-01-01

    miRNA dysregulation has recently been linked to human obesity and its related complications such as type 2 diabetes. In order to study miRNA function in human adipocytes, we aimed for the modulation of mature miRNA concentration in these cells. Adipocytes, however, tend to be resistant to transfection and there is often a need to resort to viral transduction or electroporation. Our objective therefore was to identify an efficient, non-viral transfection reagent capable of delivering small RNAs into these cells. To achieve this, we compared the efficiencies of three transfection agents, Lipofectamine 2000, ScreenFect A and BPEI 1.2 k in delivering fluorescent-labelled siRNA into human Simpson-Golabi-Behmel syndrome (SGBS) preadipocytes and adipocytes. Downregulation of a specific target gene in response to miRNA mimic overexpression was assayed in SGBS cells and also in ex vivo differentiated primary human adipocytes. Our results demonstrated that while all three transfection agents were able to internalize the oligos, only lipofection resulted in the efficient downregulation of a specific target gene both in SGBS cells and in primary human adipocytes. Lipofectamine 2000 outperformed ScreenFect A in preadipocytes, but in adipocytes the two reagents gave comparable results making ScreenFect A a notable new alternative for the gold standard Lipofectamine 2000.

  18. Establishment of lipofection for studying miRNA function in human adipocytes.

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    Eveliina Enlund

    Full Text Available miRNA dysregulation has recently been linked to human obesity and its related complications such as type 2 diabetes. In order to study miRNA function in human adipocytes, we aimed for the modulation of mature miRNA concentration in these cells. Adipocytes, however, tend to be resistant to transfection and there is often a need to resort to viral transduction or electroporation. Our objective therefore was to identify an efficient, non-viral transfection reagent capable of delivering small RNAs into these cells. To achieve this, we compared the efficiencies of three transfection agents, Lipofectamine 2000, ScreenFect A and BPEI 1.2 k in delivering fluorescent-labelled siRNA into human Simpson-Golabi-Behmel syndrome (SGBS preadipocytes and adipocytes. Downregulation of a specific target gene in response to miRNA mimic overexpression was assayed in SGBS cells and also in ex vivo differentiated primary human adipocytes. Our results demonstrated that while all three transfection agents were able to internalize the oligos, only lipofection resulted in the efficient downregulation of a specific target gene both in SGBS cells and in primary human adipocytes. Lipofectamine 2000 outperformed ScreenFect A in preadipocytes, but in adipocytes the two reagents gave comparable results making ScreenFect A a notable new alternative for the gold standard Lipofectamine 2000.

  19. Momordica charantia (bitter melon inhibits primary human adipocyte differentiation by modulating adipogenic genes

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    Nerurkar Vivek R

    2010-06-01

    Full Text Available Abstract Background Escalating trends of obesity and associated type 2 diabetes (T2D has prompted an increase in the use of alternative and complementary functional foods. Momordica charantia or bitter melon (BM that is traditionally used to treat diabetes and complications has been demonstrated to alleviate hyperglycemia as well as reduce adiposity in rodents. However, its effects on human adipocytes remain unknown. The objective of our study was to investigate the effects of BM juice (BMJ on lipid accumulation and adipocyte differentiation transcription factors in primary human differentiating preadipocytes and adipocytes. Methods Commercially available cryopreserved primary human preadipocytes were treated with and without BMJ during and after differentiation. Cytotoxicity, lipid accumulation, and adipogenic genes mRNA expression was measured by commercial enzymatic assay kits and semi-quantitative RT-PCR (RT-PCR. Results Preadipocytes treated with varying concentrations of BMJ during differentiation demonstrated significant reduction in lipid content with a concomitant reduction in mRNA expression of adipocyte transcription factors such as, peroxisome proliferator-associated receptor γ (PPARγ and sterol regulatory element-binding protein 1c (SREBP-1c and adipocytokine, resistin. Similarly, adipocytes treated with BMJ for 48 h demonstrated reduced lipid content, perilipin mRNA expression, and increased lipolysis as measured by the release of glycerol. Conclusion Our data suggests that BMJ is a potent inhibitor of lipogenesis and stimulator of lipolysis activity in human adipocytes. BMJ may therefore prove to be an effective complementary or alternative therapy to reduce adipogenesis in humans.

  20. Human adipocytes are highly sensitive to intermittent hypoxia induced NF-kappaB activity and subsequent inflammatory gene expression

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    Taylor, Cormac T.; Kent, Brian D.; Crinion, Sophie J.; McNicholas, Walter T.; Ryan, Silke

    2014-01-01

    Highlights: • Intermittent hypoxia (IH) leads to NF-κB activation in human primary adipocytes. • Adipocytes bear higher pro-inflammatory potential than other human primary cells. • IH leads to upregulation of multiple pro-inflammatory genes in human adipocytes. - Abstract: Introduction: Intermittent hypoxia (IH)-induced activation of pro-inflammatory pathways is a major contributing factor to the cardiovascular pathophysiology associated with obstructive sleep apnea (OSA). Obesity is commonly associated with OSA although it remains unknown whether adipose tissue is a major source of inflammatory mediators in response to IH. The aim of this study was to test the hypothesis that IH leads to augmented inflammatory responses in human adipocytes when compared to cells of non-adipocyte lineages. Methods and results: Human primary subcutaneous and visceral adipocytes, human primary microvascular pulmonary endothelial cells (HUMEC-L) and human primary small airway epithelial cells (SAEC) were exposed to 0, 6 or 12 cycles of IH or stimulated with tumor necrosis factor (TNF)-α. IH led to a robust increase in NF-κB DNA-binding activity in adipocytes compared with normoxic controls regardless of whether the source of adipocytes was visceral or subcutaneous. Notably, the NF-κB response of adipocytes to both IH and TNF-α was significantly greater than that in HUMEC-L and SAEC. Western blotting confirmed enhanced nuclear translocation of p65 in adipocytes in response to IH, accompanied by phosphorylation of I-κB. Parallel to p65 activation, we observed a significant increase in secretion of the adipokines interleukin (IL)-8, IL-6 and TNF-α with IH in adipocytes accompanied by significant upregulation of mRNA expression. PCR-array suggested profound influence of IH on pro-inflammatory gene expression in adipocytes. Conclusion: Human adipocytes demonstrate strong sensitivity to inflammatory gene expression in response to acute IH and hence, adipose tissue may be a key

  1. Human adipocytes are highly sensitive to intermittent hypoxia induced NF-kappaB activity and subsequent inflammatory gene expression

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    Taylor, Cormac T. [School of Medicine and Medical Science, The Conway Institute, University College Dublin (Ireland); Kent, Brian D.; Crinion, Sophie J.; McNicholas, Walter T. [School of Medicine and Medical Science, The Conway Institute, University College Dublin (Ireland); Pulmonary and Sleep Disorders Unit, St. Vincent’s University Hospital, Dublin (Ireland); Ryan, Silke, E-mail: silke.ryan@ucd.ie [School of Medicine and Medical Science, The Conway Institute, University College Dublin (Ireland); Pulmonary and Sleep Disorders Unit, St. Vincent’s University Hospital, Dublin (Ireland)

    2014-05-16

    Highlights: • Intermittent hypoxia (IH) leads to NF-κB activation in human primary adipocytes. • Adipocytes bear higher pro-inflammatory potential than other human primary cells. • IH leads to upregulation of multiple pro-inflammatory genes in human adipocytes. - Abstract: Introduction: Intermittent hypoxia (IH)-induced activation of pro-inflammatory pathways is a major contributing factor to the cardiovascular pathophysiology associated with obstructive sleep apnea (OSA). Obesity is commonly associated with OSA although it remains unknown whether adipose tissue is a major source of inflammatory mediators in response to IH. The aim of this study was to test the hypothesis that IH leads to augmented inflammatory responses in human adipocytes when compared to cells of non-adipocyte lineages. Methods and results: Human primary subcutaneous and visceral adipocytes, human primary microvascular pulmonary endothelial cells (HUMEC-L) and human primary small airway epithelial cells (SAEC) were exposed to 0, 6 or 12 cycles of IH or stimulated with tumor necrosis factor (TNF)-α. IH led to a robust increase in NF-κB DNA-binding activity in adipocytes compared with normoxic controls regardless of whether the source of adipocytes was visceral or subcutaneous. Notably, the NF-κB response of adipocytes to both IH and TNF-α was significantly greater than that in HUMEC-L and SAEC. Western blotting confirmed enhanced nuclear translocation of p65 in adipocytes in response to IH, accompanied by phosphorylation of I-κB. Parallel to p65 activation, we observed a significant increase in secretion of the adipokines interleukin (IL)-8, IL-6 and TNF-α with IH in adipocytes accompanied by significant upregulation of mRNA expression. PCR-array suggested profound influence of IH on pro-inflammatory gene expression in adipocytes. Conclusion: Human adipocytes demonstrate strong sensitivity to inflammatory gene expression in response to acute IH and hence, adipose tissue may be a key

  2. Characterization of lipid metabolism in insulin-sensitive adipocytes differentiated from immortalized human mesenchymal stem cells

    International Nuclear Information System (INIS)

    Prawitt, Janne; Niemeier, Andreas; Kassem, Moustapha; Beisiegel, Ulrike; Heeren, Joerg

    2008-01-01

    There is a great demand for cell models to study human adipocyte function. Here we describe the adipogenic differentiation of a telomerase-immortalized human mesenchymal stem cell line (hMSC-Tert) that maintains numerous features of terminally differentiated adipocytes even after prolonged withdrawal of the peroxisome proliferator activated receptor γ (PPARγ) agonist rosiglitazone. Differentiated hMSC-Tert developed the characteristic monolocular phenotype of mature adipocytes. The expression of adipocyte specific markers was highly increased during differentiation. Most importantly, the presence of the PPARγ agonist rosiglitazone was not required for the stable expression of lipoprotein lipase, adipocyte fatty acid binding protein and perilipin on mRNA and protein levels. Adiponectin expression was post-transcriptionally down-regulated in the absence of rosiglitazone. Insulin sensitivity as measured by insulin-induced phosphorylation of Akt and S6 ribosomal protein was also independent of rosiglitazone. In addition to commonly used adipogenic markers, we investigated further PPARγ-stimulated proteins with a role in lipid metabolism. We observed an increase of lipoprotein receptor (VLDLR, LRP1) and apolipoprotein E expression during differentiation. Despite this increased expression, the receptor-mediated endocytosis of lipoproteins was decreased in differentiated adipocytes, suggesting that these proteins may have an additional function in adipose tissue beyond lipoprotein uptake

  3. Regulation of lipoprotein lipase in primary cultures of isolated human adipocytes

    International Nuclear Information System (INIS)

    Kern, P.A.; Marshall, S.; Eckel, R.H.

    1985-01-01

    To study the regulation of adipose tissue lipoprotein lipase (LPL) in human adipocytes, omental adipose tissue was obtained from healthy subjects and digested in collagenase. The isolated adipocytes thus obtained were suspended in Medium 199 and cultured at 37 degrees C. Cell viability was demonstrated in adipocytes cultured for up to 72 h by constancy of cell number, cell size, trypan-blue exclusion, and specific 125 I-insulin binding. In addition, chloroquine induced an increase in cell-associated 125 I-insulin at 24, 48, and 72 h after preparation. Thus, isolated adipocytes retained their ability to bind, internalize, and degrade insulin. LPL was measured as activity secreted into the culture medium (CM), released from cells by heparin (HR), and extracted from cell digests. A broad range of heparin concentrations produced a prompt release of LPL from a rapidly replenishable pool of cellular activity. When cells were cultured in medium containing 10% fetal bovine serum, there was a marked stimulation of CM and HR. The secretory response to serum (CM) correlated strongly with HR 24 h after preparation. In addition, HR was found to correlate logarithmically and inversely with body mass index. Insulin, at 400 ng/ml only, increased HR by 36 +/- 10%, an effect simulated by lower concentrations of insulin-like growth factor-1 (IGF1). Thus, LPL is produced and regulated in isolated human adipocytes. The degree of adiposity and serum are important regulators of HR activity, whereas insulin is stimulatory only at a pharmacologic concentration. This effect of insulin may be mediated through the IGF1 receptor. Isolated human adipocytes represent a novel and useful system for the study of LPL and lipid metabolism as well as for other aspects of adipocyte biology

  4. Establishment of Lipofection for Studying miRNA Function in Human Adipocytes

    OpenAIRE

    Enlund, Eveliina; Fischer, Simon; Handrick, René; Otte, Kerstin; Debatin, Klaus-Michael; Wabitsch, Martin; Fischer-Posovszky, Pamela

    2014-01-01

    miRNA dysregulation has recently been linked to human obesity and its related complications such as type 2 diabetes. In order to study miRNA function in human adipocytes, we aimed for the modulation of mature miRNA concentration in these cells. Adipocytes, however, tend to be resistant to transfection and there is often a need to resort to viral transduction or electroporation. Our objective therefore was to identify an efficient, non-viral transfection reagent capable of delivering small RNA...

  5. Induction of adipocyte-like phenotype in human mesenchymal stem cells by hypoxia

    DEFF Research Database (Denmark)

    Fink, Trine; Abildtrup, Lisbeth Ann; Fogd, Kirsten

    2004-01-01

    Human mesenchymal stem cells (hMSCs) have the capacity to differentiate along several pathways to form bone, cartilage, tendon, muscle, and adipose tissues. The adult hMSCs reside in vivo in the bone marrow in niches where oxygen concentration is far below the ambient air, which is the most...... commonly encountered laboratory condition. The study reported here was designed to determine whether oxygen has a role in the differentiation of hMSCs into adipocytes. Indeed, when exposed to atmosphere containing only 1% of oxygen, the formation of adipocyte-like phenotype with cytoplasmic lipid....... High level of induction, however, was observed with the PPAR-gamma-induced angiopoietin-related gene, PGAR. The lack of an adipocyte-specific transcription pattern thus indicates that despite accumulation of the lipid, true adipogenic differentiation did not take place. In conclusion, hypoxia appears...

  6. Multiple intracellular signaling pathways orchestrate adipocytic differentiation of human bone marrow stromal stem cells

    DEFF Research Database (Denmark)

    Ayesh Hafez Ali, Dalia; Abuelreich, Sarah; Alkeraishan, Nora

    2018-01-01

    during adipocyte differentiation of human bone marrow stromal (mesenchymal) stem cells (hMSCs) and identified 2,589 up-regulated and 2,583 down-regulated mRNA transcripts. Pathway analysis on the up-regulated gene list untraveled enrichment in multiple signaling pathways including insulin receptor......Bone marrow adipocyte formation plays a role in bone homeostasis and whole body energy metabolism. However, the transcriptional landscape and signaling pathways associated with adipocyte lineage commitment and maturation are not fully delineated. Thus, we performed global gene expression profiling...... signaling, focal Adhesion, metapathway biotransformation, a number of metabolic pathways e.g. selenium metabolism, Benzo(a)pyrene metabolism, fatty acid, triacylglycerol, ketone body metabolism, tryptophan metabolism, and catalytic cycle of mammalian flavin-containing monooxygenase (FMOs). On the other hand...

  7. Atypical antipsychotics induce both proinflammatory and adipogenic gene expression in human adipocytes in vitro

    International Nuclear Information System (INIS)

    Sárvári, Anitta K.; Veréb, Zoltán; Uray, Iván P.; Fésüs, László; Balajthy, Zoltán

    2014-01-01

    Highlights: • Antipsychotics modulate the expression of adipogenic genes in human adipocytes. • Secretion of proinflammatory cytokine IL8 and MCP-1 is induced by antipsychotics. • Adipocyte-dependent inflammatory abnormality could develop during chronic treatment. • Infiltrated macrophages would further enhance proinflammatory cytokine production. - Abstract: Schizophrenia requires lifelong treatment, potentially causing systemic changes in metabolic homeostasis. In the clinical setting, antipsychotic treatment may differentially lead to weight gain among individual patients, although the molecular determinants of such adverse effects are currently unknown. In this study, we investigated changes in the expression levels of critical regulatory genes of adipogenesis, lipid metabolism and proinflammatory genes during the differentiation of primary human adipose-derived stem cells (ADSCs). These cells were isolated from patients with body mass indices <25 and treated with the second-generation antipsychotics olanzapine, ziprasidone, clozapine, quetiapine, aripiprazole and risperidone and the first-generation antipsychotic haloperidol. We found that antipsychotics exhibited a marked effect on key genes involved in the regulation of cell cycle, signal transduction, transcription factors, nuclear receptors, differentiation markers and metabolic enzymes. In particular, we observed an induction of the transcription factor NF-KB1 and NF-KB1 target genes in adipocytes in response to these drugs, including the proinflammatory cytokines TNF-α, IL-1β, IL-8 and MCP-1. In addition, enhanced secretion of both IL8 and MCP-1 was observed in the supernatant of these cell cultures. In addition to their remarkable stimulatory effects on proinflammatory gene transcription, three of the most frequently prescribed antipsychotic drugs, clozapine, quetiapine and aripiprazole, also induced the expression of essential adipocyte differentiation genes and the adipocyte hormones leptin

  8. Atypical antipsychotics induce both proinflammatory and adipogenic gene expression in human adipocytes in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Sárvári, Anitta K., E-mail: anittasarvari@med.unideb.hu [Department of Biochemistry and Molecular Biology, Medical and Health Science Center, University of Debrecen, Debrecen (Hungary); Veréb, Zoltán, E-mail: jzvereb@gmail.com [Department of Biochemistry and Molecular Biology, Medical and Health Science Center, University of Debrecen, Debrecen (Hungary); Uray, Iván P., E-mail: ipuray@mdanderson.org [Clinical Cancer Prevention Department, The University of Texas, MD Anderson Cancer Center, Houston, TX (United States); Fésüs, László, E-mail: fesus@med.unideb.hu [Department of Biochemistry and Molecular Biology, Medical and Health Science Center, University of Debrecen, Debrecen (Hungary); MTA DE Apoptosis, Genomics and Stem Cell Research Group of the Hungarian Academy of Sciences (Hungary); Balajthy, Zoltán, E-mail: balajthy@med.unideb.hu [Department of Biochemistry and Molecular Biology, Medical and Health Science Center, University of Debrecen, Debrecen (Hungary)

    2014-08-08

    Highlights: • Antipsychotics modulate the expression of adipogenic genes in human adipocytes. • Secretion of proinflammatory cytokine IL8 and MCP-1 is induced by antipsychotics. • Adipocyte-dependent inflammatory abnormality could develop during chronic treatment. • Infiltrated macrophages would further enhance proinflammatory cytokine production. - Abstract: Schizophrenia requires lifelong treatment, potentially causing systemic changes in metabolic homeostasis. In the clinical setting, antipsychotic treatment may differentially lead to weight gain among individual patients, although the molecular determinants of such adverse effects are currently unknown. In this study, we investigated changes in the expression levels of critical regulatory genes of adipogenesis, lipid metabolism and proinflammatory genes during the differentiation of primary human adipose-derived stem cells (ADSCs). These cells were isolated from patients with body mass indices <25 and treated with the second-generation antipsychotics olanzapine, ziprasidone, clozapine, quetiapine, aripiprazole and risperidone and the first-generation antipsychotic haloperidol. We found that antipsychotics exhibited a marked effect on key genes involved in the regulation of cell cycle, signal transduction, transcription factors, nuclear receptors, differentiation markers and metabolic enzymes. In particular, we observed an induction of the transcription factor NF-KB1 and NF-KB1 target genes in adipocytes in response to these drugs, including the proinflammatory cytokines TNF-α, IL-1β, IL-8 and MCP-1. In addition, enhanced secretion of both IL8 and MCP-1 was observed in the supernatant of these cell cultures. In addition to their remarkable stimulatory effects on proinflammatory gene transcription, three of the most frequently prescribed antipsychotic drugs, clozapine, quetiapine and aripiprazole, also induced the expression of essential adipocyte differentiation genes and the adipocyte hormones leptin

  9. Inhibition of fatty acid biosynthesis prevents adipocyte lipotoxicity on human osteoblasts in vitro

    Science.gov (United States)

    Elbaz, Alexandre; Wu, Xiying; Rivas, Daniel; Gimble, Jeffrey M; Duque, Gustavo

    2010-01-01

    Abstract Although increased bone marrow fat in age-related bone loss has been associated with lower trabecular mass, the underlying mechanism responsible remains unknown. We hypothesized that marrow adipocytes exert a lipotoxic effect on osteoblast function and survival through the reversible biosynthesis of fatty acids (FA) into the bone marrow microenvironment. We have used a two-chamber system to co-culture normal human osteoblasts (NHOst) with differentiating pre-adipocytes in the absence or presence of an inhibitor of FA synthase (cerulenin) and separated by an insert that allowed unidirectional trafficking of soluble factors only and prevented direct cell–cell contact. Supernatants were assayed for the presence of FA using mass spectophotometry. After 3 weeks in co-culture, NHOst showed significantly lower levels of differentiation and function based on lower mineralization and expression of alkaline phosphatase, osterix, osteocalcin and Runx2. In addition, NHOst survival was affected by the presence of adipocytes as determined by MTS-formazan and TUNEL assays as well as higher activation of caspases 3/7. These toxic effects were inhibited by addition of cerulenin. Furthermore, culture of NHOst with either adipocyte-conditioned media alone in the absence of adipocytes themselves or with the addition of the most predominant FA (stearate or palmitate) produced similar toxic results. Finally, Runx2 nuclear binding was affected by addition of either adipocyte conditioned media or FA into the osteogenic media. We conclude that the presence of FA within the marrow milieu can contribute to the age-related changes in bone mass and can be prevented by the inhibition of FA synthase. PMID:19382912

  10. Ursodeoxycholic acid but not tauroursodeoxycholic acid inhibits proliferation and differentiation of human subcutaneous adipocytes.

    Directory of Open Access Journals (Sweden)

    Lucia Mališová

    Full Text Available Stress of endoplasmic reticulum (ERS is one of the molecular triggers of adipocyte dysfunction and chronic low inflammation accompanying obesity. ERS can be alleviated by chemical chaperones from the family of bile acids (BAs. Thus, two BAs currently used to treat cholestasis, ursodeoxycholic and tauroursodeoxycholic acid (UDCA and TUDCA, could potentially lessen adverse metabolic effects of obesity. Nevertheless, BAs effects on human adipose cells are mostly unknown. They could regulate gene expression through pathways different from their chaperone function, namely through activation of farnesoid X receptor (FXR and TGR5, G-coupled receptor. Therefore, this study aimed to analyze effects of UDCA and TUDCA on human preadipocytes and differentiated adipocytes derived from paired samples of two distinct subcutaneous adipose tissue depots, abdominal and gluteal. While TUDCA did not alter proliferation of cells from either depot, UDCA exerted strong anti-proliferative effect. In differentiated adipocytes, acute exposition to neither TUDCA nor UDCA was able to reduce effect of ERS stressor tunicamycin. However, exposure of cells to UDCA during whole differentiation process decreased expression of ERS markers. At the same time however, UDCA profoundly inhibited adipogenic conversion of cells. UDCA abolished expression of PPARγ and lipogenic enzymes already in the early phases of adipogenesis. This anti-adipogenic effect of UDCA was not dependent on FXR or TGR5 activation, but could be related to ability of UDCA to sustain the activation of ERK1/2 previously linked with PPARγ inactivation. Finally, neither BAs did lower expression of chemokines inducible by TLR4 pathway, when UDCA enhanced their expression in gluteal adipocytes. Therefore while TUDCA has neutral effect on human preadipocytes and adipocytes, the therapeutic use of UDCA different from treating cholestatic diseases should be considered with caution because UDCA alters functions of

  11. The lipid fraction of human milk initiates adipocyte differentiation in 3T3-L1 cells.

    Science.gov (United States)

    Fujisawa, Yasuko; Yamaguchi, Rie; Nagata, Eiko; Satake, Eiichiro; Sano, Shinichiro; Matsushita, Rie; Kitsuta, Kazunobu; Nakashima, Shinichi; Nakanishi, Toshiki; Nakagawa, Yuichi; Ogata, Tsutomu

    2013-09-01

    The prevalence of childhood obesity has increased worldwide over the past decade. Despite evidence that human milk lowers the risk of childhood obesity, the mechanism is not fully understood. We investigated the direct effect of human milk on differentiation of 3T3-L1 preadipocytes. 3T3-L1 preadipocytes were treated with donated human milk only or the combination of the standard hormone mixture; insulin, dexamethasone (DEX), and 3-isobututyl-1-methylxanthine (IBMX). Furthermore, the induction of preadipocyte differentiation by extracted lipids from human milk was tested in comparison to the cells treated with lipid extracts from infant formula. Adipocyte differentiation, specific genes as well as formation of lipid droplets were examined. We clearly show that lipids present in human milk initiate 3T3-L1 preadipocyte differentiation. In contrast, this effect was not observed in response to lipids present in infant formula. The initiation of preadipocyte differentiation by human milk was enhanced by adding the adipogenic hormone, DEX or insulin. The expression of late adipocyte markers in Day 7 adipocytes that have been induced into differentiation with human milk lipid extracts was comparable to those in control cells initiated by a standard adipogenic hormone cocktail. These results demonstrate that human milk contains bioactive lipids that can initiate preadipocyte differentiation in the absence of the standard adipogenic compounds via a unique pathway. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. 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...

  13. Interaction of differentiated human adipocytes with macrophages leads to trogocytosis and selective IL-6 secretion.

    Science.gov (United States)

    Sárvári, A K; Doan-Xuan, Q-M; Bacsó, Z; Csomós, I; Balajthy, Z; Fésüs, L

    2015-01-22

    Obesity leads to adipose tissue inflammation that is characterized by increased release of proinflammatory molecules and the recruitment of activated immune cells. Although macrophages are present in the highest number among the immune cells in obese adipose tissue, not much is known about their direct interaction with adipocytes. We have introduced an ex vivo experimental system to characterize the cellular interactions and the profile of secreted cytokines in cocultures of macrophages and human adipocytes differentiated from either mesenchymal stem cells or a preadipocyte cell line. As observed by time-lapse microscopy, flow, and laser-scanning cytometry, macrophages phagocytosed bites of adipocytes (trogocytosis), which led to their de novo, phagocytosis and NF-κB-dependent synthesis, then release of interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1. IL-6 secretion was not accompanied by secretion of other proinflammatory cytokines, such as tumor necrosis factor (TNF)-α and IL-8, except MCP-1. LPS-induced release of TNF-α, IL-8 and MCP-1 was decreased in the presence of the differentiated adipocytes but the IL-6 level did not subside suggesting that phagocytosis-dependent IL-6 secretion may have significant regulatory function in the inflamed adipose tissue.

  14. Expression, purification, crystallization and structure of human adipocyte lipid-binding protein (aP2)

    International Nuclear Information System (INIS)

    Marr, Eric; Tardie, Mark; Carty, Maynard; Brown Phillips, Tracy; Wang, Ing-Kae; Soeller, Walt; Qiu, Xiayang; Karam, George

    2006-01-01

    The crystal structure of human adipocyte lipid-binding protein (aP2) with a bound palmitate is reported at 1.5 Å resolution. Human adipocyte lipid-binding protein (aP2) belongs to a family of intracellular lipid-binding proteins involved in the transport and storage of lipids. Here, the crystal structure of human aP2 with a bound palmitate is described at 1.5 Å resolution. Unlike the known crystal structure of murine aP2 in complex with palmitate, this structure shows that the fatty acid is in a folded conformation and that the loop containing Phe57 acts as a lid to regulate ligand binding by excluding solvent exposure to the central binding cavity

  15. Atrial natriuretic peptide regulates lipid mobilization and oxygen consumption in human adipocytes by activating AMPK

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Sandra C. [Translational Sciences - Translational Medicine, Novartis Institutes for Biomedical Research, Inc., 220 Massachusetts Avenue, Cambridge, MA 02139 (United States); Chau, Mary D.L.; Yang, Qing [Cardiovascular and Metabolism Disease Area, Novartis Institutes for Biomedical Research, Inc., 100 Technology Square, Cambridge, MA 02139 (United States); Gauthier, Marie-Soleil [Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02140 (United States); Clairmont, Kevin B.; Wu, Zhidan; Gromada, Jesper [Cardiovascular and Metabolism Disease Area, Novartis Institutes for Biomedical Research, Inc., 100 Technology Square, Cambridge, MA 02139 (United States); Dole, William P., E-mail: bill.dole@novartis.com [Translational Sciences - Translational Medicine, Novartis Institutes for Biomedical Research, Inc., 220 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2011-07-08

    Highlights: {yields} Treatment of differentiated human adipocytes with atrial natriuretic peptide (ANP) increased lipolysis and oxygen consumption by activating AMP-activated protein kinase (AMPK). {yields} ANP stimulated lipid mobilization by selective activation of the alpha2 subunit of AMPK and increased energy utilization through activation of both the alpha1 and alpha2 subunits of AMPK. {yields} ANP enhanced adipocyte mitochondrial oxidative capacity as evidenced by induction of oxidative mitochondrial genes and increase in oxygen consumption. {yields} Exposure of human adipocytes to fatty acids and (TNF{alpha}) induced insulin resistance and decreased expression of mitochondrial genes which was restored to normal by ANP. -- Abstract: Atrial natriuretic peptide (ANP) has been shown to regulate lipid and carbohydrate metabolism providing a possible link between cardiovascular function and metabolism by mediating the switch from carbohydrate to lipid mobilization and oxidation. ANP exerts a potent lipolytic effect via cGMP-dependent protein kinase (cGK)-I mediated-stimulation of AMP-activated protein kinase (AMPK). Activation of the ANP/cGK signaling cascade also promotes muscle mitochondrial biogenesis and fat oxidation. Here we demonstrate that ANP regulates lipid metabolism and oxygen utilization in differentiated human adipocytes by activating the alpha2 subunit of AMPK. ANP treatment increased lipolysis by seven fold and oxygen consumption by two fold, both of which were attenuated by inhibition of AMPK activity. ANP-induced lipolysis was shown to be mediated by the alpha2 subunit of AMPK as introduction of dominant-negative alpha2 subunit of AMPK attenuated ANP effects on lipolysis. ANP-induced activation of AMPK enhanced mitochondrial oxidative capacity as evidenced by a two fold increase in oxygen consumption and induction of mitochondrial genes, including carnitine palmitoyltransferase 1A (CPT1a) by 1.4-fold, cytochrome C (CytC) by 1.3-fold, and

  16. Atrial natriuretic peptide regulates lipid mobilization and oxygen consumption in human adipocytes by activating AMPK

    International Nuclear Information System (INIS)

    Souza, Sandra C.; Chau, Mary D.L.; Yang, Qing; Gauthier, Marie-Soleil; Clairmont, Kevin B.; Wu, Zhidan; Gromada, Jesper; Dole, William P.

    2011-01-01

    Highlights: → Treatment of differentiated human adipocytes with atrial natriuretic peptide (ANP) increased lipolysis and oxygen consumption by activating AMP-activated protein kinase (AMPK). → ANP stimulated lipid mobilization by selective activation of the alpha2 subunit of AMPK and increased energy utilization through activation of both the alpha1 and alpha2 subunits of AMPK. → ANP enhanced adipocyte mitochondrial oxidative capacity as evidenced by induction of oxidative mitochondrial genes and increase in oxygen consumption. → Exposure of human adipocytes to fatty acids and (TNFα) induced insulin resistance and decreased expression of mitochondrial genes which was restored to normal by ANP. -- Abstract: Atrial natriuretic peptide (ANP) has been shown to regulate lipid and carbohydrate metabolism providing a possible link between cardiovascular function and metabolism by mediating the switch from carbohydrate to lipid mobilization and oxidation. ANP exerts a potent lipolytic effect via cGMP-dependent protein kinase (cGK)-I mediated-stimulation of AMP-activated protein kinase (AMPK). Activation of the ANP/cGK signaling cascade also promotes muscle mitochondrial biogenesis and fat oxidation. Here we demonstrate that ANP regulates lipid metabolism and oxygen utilization in differentiated human adipocytes by activating the alpha2 subunit of AMPK. ANP treatment increased lipolysis by seven fold and oxygen consumption by two fold, both of which were attenuated by inhibition of AMPK activity. ANP-induced lipolysis was shown to be mediated by the alpha2 subunit of AMPK as introduction of dominant-negative alpha2 subunit of AMPK attenuated ANP effects on lipolysis. ANP-induced activation of AMPK enhanced mitochondrial oxidative capacity as evidenced by a two fold increase in oxygen consumption and induction of mitochondrial genes, including carnitine palmitoyltransferase 1A (CPT1a) by 1.4-fold, cytochrome C (CytC) by 1.3-fold, and peroxisome proliferator

  17. Protein phosphorylation in isolated human adipocytes - Adrenergic control of the phosphorylation of hormone-sensitive lipase

    International Nuclear Information System (INIS)

    Smiley, R.M.; Paul, S.; Browning, M.D.; Leibel, R.L.; Hirsch, J.

    1990-01-01

    The effect of adrenergic agents on protein phosphorylation in human adipocytes was examined. Freshly isolated human fat cells were incubated with 32 PO 4 in order to label intracellular ATP, then treated with a variety of adrenergic and other pharmacologic agents. Treatment with the β-adrenergic agonist isoproterenol led to a significant increase in phosphate content of at least five protein bands (M r 52, 53, 63, 67, 84 kDa). The increase in phosphorylation was partially inhibited by the α-2 agonist clonidine. Epinephrine, a combined α and β agonist, was less effective at increasing phosphate content of the proteins than was isoproterenol. Neither insulin nor the α-1 agonist phenylephrine had any discernible effect on the pattern of protein phosphorylation. The 84 kDa phosphorylated peptide band appears to contain hormone-sensitive lipase, a key enzyme in the lipolytic pathway which is activated by phosphorylation. These results are somewhat different than previously reported results for rat adipocytes, and represent the first report of overall pattern and adrenergic modulation of protein phosphorylation in human adipocytes

  18. Visfatin expression analysis in association with recruitment and activation of human and rodent brown and brite adipocytes

    OpenAIRE

    Pisani, Didier F.; Dumortier, Olivier; Beranger, Guillaume E.; Casamento, Virginie; Ghandour, Rayane A.; Giroud, Maude; Gautier, Nadine; Balaguer, Thierry; Chambard, Jean-Claude; Virtanen, Kirsi A.; Nuutila, Pirjo; Niemi, Tarja; Taittonen, Markku; Van Obberghen, Emmanuel; Hinault, Charlotte

    2015-01-01

    Human brown adipocytes are able to burn fat and glucose and are now considered as a potential strategy to treat obesity, type 2 diabetes and metabolic disorders. Besides their thermogenic function, brown adipocytes are able to secrete adipokines. One of these is visfatin, a nicotinamide phosphoribosyltransferase involved in nicotinamide dinucleotide synthesis, which is known to participate in the synthesis of insulin by pancreatic β cells. In a therapeutic context, it is of interest to establ...

  19. Atypical antipsychotics induce both proinflammatory and adipogenic gene expression in human adipocytes in vitro.

    Science.gov (United States)

    Sárvári, Anitta K; Veréb, Zoltán; Uray, Iván P; Fésüs, László; Balajthy, Zoltán

    2014-08-08

    Schizophrenia requires lifelong treatment, potentially causing systemic changes in metabolic homeostasis. In the clinical setting, antipsychotic treatment may differentially lead to weight gain among individual patients, although the molecular determinants of such adverse effects are currently unknown. In this study, we investigated changes in the expression levels of critical regulatory genes of adipogenesis, lipid metabolism and proinflammatory genes during the differentiation of primary human adipose-derived stem cells (ADSCs). These cells were isolated from patients with body mass indices <25 and treated with the second-generation antipsychotics olanzapine, ziprasidone, clozapine, quetiapine, aripiprazole and risperidone and the first-generation antipsychotic haloperidol. We found that antipsychotics exhibited a marked effect on key genes involved in the regulation of cell cycle, signal transduction, transcription factors, nuclear receptors, differentiation markers and metabolic enzymes. In particular, we observed an induction of the transcription factor NF-KB1 and NF-KB1 target genes in adipocytes in response to these drugs, including the proinflammatory cytokines TNF-α, IL-1β, IL-8 and MCP-1. In addition, enhanced secretion of both IL8 and MCP-1 was observed in the supernatant of these cell cultures. In addition to their remarkable stimulatory effects on proinflammatory gene transcription, three of the most frequently prescribed antipsychotic drugs, clozapine, quetiapine and aripiprazole, also induced the expression of essential adipocyte differentiation genes and the adipocyte hormones leptin and adiponectin, suggesting that both glucose and fat metabolism may be affected by these drugs. These data further suggest that antipsychotic treatments in patients alter the gene expression patterns in adipocytes in a coordinated fashion and priming them for a low-level inflammatory state. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. AMP-Activated Kinase (AMPK Activation by AICAR in Human White Adipocytes Derived from Pericardial White Adipose Tissue Stem Cells Induces a Partial Beige-Like Phenotype.

    Directory of Open Access Journals (Sweden)

    Omar Abdul-Rahman

    Full Text Available Beige adipocytes are special cells situated in the white adipose tissue. Beige adipocytes, lacking thermogenic cues, morphologically look quite similar to regular white adipocytes, but with a markedly different response to adrenalin. White adipocytes respond to adrenergic stimuli by enhancing lipolysis, while in beige adipocytes adrenalin induces mitochondrial biogenesis too. A key step in the differentiation and function of beige adipocytes is the deacetylation of peroxisome proliferator-activated receptor (PPARγ by SIRT1 and the consequent mitochondrial biogenesis. AMP-activated protein kinase (AMPK is an upstream activator of SIRT1, therefore we set out to investigate the role of AMPK in beige adipocyte differentiation using human adipose-derived mesenchymal stem cells (hADMSCs from pericardial adipose tissue. hADMSCs were differentiated to white and beige adipocytes and the differentiation medium of the white adipocytes was supplemented with 100 μM [(2R,3S,4R,5R-5-(4-Carbamoyl-5-aminoimidazol-1-yl-3,4-dihydroxyoxolan-2-yl]methyl dihydrogen phosphate (AICAR, a known activator of AMPK. The activation of AMPK with AICAR led to the appearance of beige-like morphological properties in differentiated white adipocytes. Namely, smaller lipid droplets appeared in AICAR-treated white adipocytes in a similar fashion as in beige cells. Moreover, in AICAR-treated white adipocytes the mitochondrial network was more fused than in white adipocytes; a fused mitochondrial system was characteristic to beige adipocytes. Despite the morphological similarities between AICAR-treated white adipocytes and beige cells, functionally AICAR-treated white adipocytes were similar to white adipocytes. We were unable to detect increases in basal or cAMP-induced oxygen consumption rate (a marker of mitochondrial biogenesis when comparing control and AICAR-treated white adipocytes. Similarly, markers of beige adipocytes such as TBX1, UCP1, CIDEA, PRDM16 and TMEM26 remained

  1. Nutritional Ingredients Modulate Adipokine Secretion and Inflammation in Human Primary Adipocytes

    Science.gov (United States)

    Romacho, Tania; Glosse, Philipp; Richter, Isabel; Elsen, Manuela; Schoemaker, Marieke H.; van Tol, Eric A.; Eckel, Jürgen

    2015-01-01

    Nutritional factors such as casein hydrolysates and long chain polyunsaturated fatty acids have been proposed to exert beneficial metabolic effects. We aimed to investigate how a casein hydrolysate (eCH) and long chain polyunsaturated fatty acids could affect human primary adipocyte function in vitro. Incubation conditions with the different nutritional factors were validated by assessing cell vitality with lactate dehydrogenase (LDH) release and neutral red incorporation. Intracellular triglyceride content was assessed with Oil Red O staining. The effect of eCH, a non-peptidic amino acid mixture (AA), and long-chain polyunsaturated fatty acids (LC-PUFAs) on adiponectin and leptin secretion was determined by enzyme-linked immunosorbent assay (ELISA). Intracellular adiponectin expression and nuclear factor-κB (NF-κB) activation were analyzed by Western blot, while monocyte chemoattractant protein-1 (MCP-1) release was explored by ELISA. The eCH concentration dependently increased adiponectin secretion in human primary adipocytes through its intrinsic peptide bioactivity, since the non-peptidic mixture, AA, could not mimic eCH’s effects on adiponectin secretion. Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and DHA combined with arachidonic acid (ARA) upregulated adiponectin secretion. However, only DHA and DHA/ARA exerted a potentanti-inflammatory effect reflected by prevention of tumor necrosis factor-α (TNF-α) induced NF-κB activation and MCP-1 secretion in human adipocytes. eCH and DHA alone or in combination with ARA, may hold the key for nutritional programming through their anti-inflammatory action to prevent diseases with low-grade chronic inflammation such as obesity or diabetes. PMID:25629558

  2. Nutritional Ingredients Modulate Adipokine Secretion and Inflammation in Human Primary Adipocytes

    Directory of Open Access Journals (Sweden)

    Tania Romacho

    2015-01-01

    Full Text Available Nutritional factors such as casein hydrolysates and long chain polyunsaturated fatty acids have been proposed to exert beneficial metabolic effects. We aimed to investigate how a casein hydrolysate (eCH and long chain polyunsaturated fatty acids could affect human primary adipocyte function in vitro. Incubation conditions with the different nutritional factors were validated by assessing cell vitality with lactate dehydrogenase (LDH release and neutral red incorporation. Intracellular triglyceride content was assessed with Oil Red O staining. The effect of eCH, a non-peptidic amino acid mixture (AA, and long-chain polyunsaturated fatty acids (LC-PUFAs on adiponectin and leptin secretion was determined by enzyme-linked immunosorbent assay (ELISA. Intracellular adiponectin expression and nuclear factor-κB (NF-κB activation were analyzed by Western blot, while monocyte chemoattractant protein-1 (MCP-1 release was explored by ELISA. The eCH concentration dependently increased adiponectin secretion in human primary adipocytes through its intrinsic peptide bioactivity, since the non-peptidic mixture, AA, could not mimic eCH’s effects on adiponectin secretion. Eicosapentaenoic acid (EPA, docosahexaenoic acid (DHA, and DHA combined with arachidonic acid (ARA upregulated adiponectin secretion. However, only DHA and DHA/ARA exerted a potentanti-inflammatory effect reflected by prevention of tumor necrosis factor-α (TNF-α induced NF-κB activation and MCP-1 secretion in human adipocytes. eCH and DHA alone or in combination with ARA, may hold the key for nutritional programming through their anti-inflammatory action to prevent diseases with low-grade chronic inflammation such as obesity or diabetes.

  3. A biomimetic physiological model for human adipose tissue by adipocytes and endothelial cell cocultures with spatially controlled distribution

    International Nuclear Information System (INIS)

    Yao, Rui; Zhang, Renji; Lin, Feng; Du, Yanan; Luan, Jie

    2013-01-01

    An in vitro model that recapitulates the characteristics of native human adipose tissue would largely benefit pathology studies and therapy development. In this paper, we fabricated a physiological model composed of both human adipocytes and endothelial cells with spatially controlled distribution that biomimics the structure and composition of human adipose tissue. Detailed studies into the cell–cell interactions between the adipocytes and endothelial cells revealed a mutual-enhanced effect which resembles the in vivo routine. Furthermore, comparisons between planar coculture and model coculture demonstrated improved adipocyte function as well as endothelial cell proliferation under the same conditions. This research provided a reliable model for human adipose tissue development studies and potential obesity-related therapy development. (paper)

  4. Effect of the Cannabinoid Receptor-1 antagonist SR141716A on human adipocyte inflammatory profile and differentiation

    Directory of Open Access Journals (Sweden)

    Murumalla Ravi

    2011-11-01

    Full Text Available Abstract Background Obesity is characterized by inflammation, caused by increase in proinflammatory cytokines, a key factor for the development of insulin resistance. SR141716A, a cannabinoid receptor 1 (CB1 antagonist, shows significant improvement in clinical status of obese/diabetic patients. Therefore, we studied the effect of SR141716A on human adipocyte inflammatory profile and differentiation. Methods Adipocytes were obtained from liposuction. Stromal vascular cells were extracted and differentiated into adipocytes. Media and cells were collected for secretory (ELISA and expression analysis (qPCR. Triglyceride accumulation was observed using oil red-O staining. Cholesterol was assayed by a fluorometric method. 2-AG and anandamide were quantified using isotope dilution LC-MS. TLR-binding experiments have been conducted in HEK-Blue cells. Results In LPS-treated mature adipocytes, SR141716A was able to decrease the expression and secretion of TNF-a. This molecule has the same effect in LPS-induced IL-6 secretion, while IL-6 expression is not changed. Concerning MCP-1, the basal level is down-regulated by SR141716A, but not the LPS-induced level. This effect is not caused by a binding of the molecule to TLR4 (LPS receptor. Moreover, SR141716A restored adiponectin secretion to normal levels after LPS treatment. Lastly, no effect of SR141716A was detected on human pre-adipocyte differentiation, although the compound enhanced adiponectin gene expression, but not secretion, in differentiated pre-adipocytes. Conclusion We show for the first time that some clinical effects of SR141716A are probably directly related to its anti-inflammatory effect on mature adipocytes. This fact reinforces that adipose tissue is an important target in the development of tools to treat the metabolic syndrome.

  5. The Influence of a KDT501, a Novel Isohumulone, on Adipocyte Function in Humans

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    Brian S. Finlin

    2017-09-01

    Full Text Available ObjectiveIn a phase II clinical trial in nine obese, insulin-resistant humans, we observed that treatment with KDT501, a novel isohumulone drug, increased total and high-molecular weight (HMW adiponectin in plasma. The objective was to determine whether KDT501 increased adiponectin secretion from subcutaneous white adipose tissue (SC WAT and the underlying mechanism(s.MethodsNine obese participants with either prediabetes or with normal glucose tolerance plus three features of metabolic syndrome were part of the study. SC WAT biopsies were performed before and after 28 days of KDT501 treatment in a clinical research setting. In addition, a cold stimulus was used to induce thermogenic gene expression. Adiponectin secretion was measured, and gene expression of 130 genes involved in adipose tissue function was determined. The effect of KDT501 on adipocyte mitochondrial function was analyzed in vitro.ResultsSC WAT explants secreted more total and HMW adiponectin after KDT501 treatment (P < 0.05. After KDT501 treatment, a number of genes involved in thermogenesis and lipolysis were induced by cold (P < 0.05. KDT501 also potentiated β-adrenergic signaling (P < 0.001 and enhanced mitochondrial function in adipocytes (P < 0.001.ConclusionKDT501 induced adiponectin secretion posttranscriptionally and increased gene expression of thermogenic and lipolytic genes in response to cold stimulation. These beneficial effects on SC WAT may be explained by the ability of KDT501 to potentiate β-adrenergic signaling and enhance mitochondrial function in adipocytes.Clinical Trial Registrationhttps://www.ClinicalTrials.gov, ID number: NCT02444910.

  6. Development of a rapid culture method to induce adipocyte differentiation of human bone marrow-derived mesenchymal stem cells

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    Ninomiya, Yuichi; Sugahara-Yamashita, Yzumi; Nakachi, Yutaka; Tokuzawa, Yoshimi; Okazaki, Yasushi; Nishiyama, Masahiko

    2010-01-01

    Human mesenchymal stem cells (hMSCs) derived from bone marrow are multipotent stem cells that can regenerate mesenchymal tissues such as adipose, bone or muscle. It is thought that hMSCs can be utilized as a cell resource for tissue engineering and as human models to study cell differentiation mechanisms, such as adipogenesis, osteoblastogenesis and so on. Since it takes 2-3 weeks for hMSCs to differentiate into adipocytes using conventional culture methods, the development of methods to induce faster differentiation into adipocytes is required. In this study we optimized the culture conditions for adipocyte induction to achieve a shorter cultivation time for the induction of adipocyte differentiation in bone marrow-derived hMSCs. Briefly, we used a cocktail of dexamethasone, insulin, methylisobutylxanthine (DIM) plus a peroxisome proliferator-activated receptor γ agonist, rosiglitazone (DIMRo) as a new adipogenic differentiation medium. We successfully shortened the period of cultivation to 7-8 days from 2-3 weeks. We also found that rosiglitazone alone was unable to induce adipocyte differentiation from hMSCs in vitro. However, rosiglitazone appears to enhance hMSC adipogenesis in the presence of other hormones and/or compounds, such as DIM. Furthermore, the inhibitory activity of TGF-β1 on adipogenesis could be investigated using DIMRo-treated hMSCs. We conclude that our rapid new culture method is very useful in measuring the effect of molecules that affect adipogenesis in hMSCs.

  7. Differentiation of human pluripotent stem cells into highly functional classical brown adipocytes.

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    Nishio, Miwako; Saeki, Kumiko

    2014-01-01

    We describe a detailed method for directed differentiation of human pluripotent stem cells, including human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), into functional classical brown adipocytes (BAs) under serum-free and feeder-free conditions. It is a two-tiered culture system, based on very simple techniques, a floating culture and a subsequent adherent culture. It does not require gene transfer. The entire process can be carried out in about 10 days. The key point is the usage of our special hematopoietic cytokine cocktail. Almost all the differentiated cells express uncoupling protein 1, a BA-selective marker, as determined by immunostaining. The differentiated cells show characteristics of classical BA as assessed by morphology and gene/protein expression. Moreover, the expression of myoblast marker genes is transiently induced during the floating culture step. hESC/hiPSC-derived BAs show significantly higher oxygen consumption rates (OCRs) than white adipocytes generated from human mesenchymal stem cell. They also show responsiveness to adrenergic stimuli, with about twofold upregulation in OCR by β-adrenergic receptor (β-AR) agonist treatments. hESC/hiPSC-derived BAs exert in vivo calorigenic activities in response to β-AR agonist treatments as assessed by thermography. Finally, lipid and glucose metabolisms are significantly improved in hESC/hiPSC-derived BA-transplanted mice. Our system provides a highly feasible way to produce functional classical BA bearing metabolism-improving capacities from hESC/hiPSC under a feeder-free and serum-free condition without gene transfer. © 2014 Elsevier Inc. All rights reserved.

  8. Ibervillea sonorae (Cucurbitaceae) induces the glucose uptake in human adipocytes by activating a PI3K-independent pathway.

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    Zapata-Bustos, Rocio; Alonso-Castro, Angel Josabad; Gómez-Sánchez, Maricela; Salazar-Olivo, Luis A

    2014-03-28

    Ibervillea sonorae (S. Watson) Greene (Cucurbitaceae), a plant used for the empirical treatment of type 2 diabetes in México, exerts antidiabetic effects on animal models but its mechanism of action remains unknown. The aim of this study is to investigate the antidiabetic mechanism of an Ibervillea sonorae aqueous extract (ISE). Non-toxic ISE concentrations were assayed on the glucose uptake by insulin-sensitive and insulin-resistant murine and human cultured adipocytes, both in the absence or the presence of insulin signaling pathway inhibitors, and on murine and human adipogenesis. Chemical composition of ISE was examined by spectrophotometric and HPLC techniques. ISE stimulated the 2-NBDGlucose uptake by mature adipocytes in a concentration-dependent manner. ISE 50 µg/ml induced the 2-NBDG uptake in insulin-sensitive 3T3-F442A, 3T3-L1 and human adipocytes by 100%, 63% and 33%, compared to insulin control. Inhibitors for the insulin receptor, PI3K, AKT and GLUT4 blocked the 2-NBDG uptake in murine cells, but human adipocytes were insensitive to the PI3K inhibitor Wortmannin. ISE 50 µg/ml also stimulated the 2-NBDG uptake in insulin-resistant adipocytes by 117% (3T3-F442A), 83% (3T3-L1) and 48% (human). ISE induced 3T3-F442A adipogenesis but lacked proadipogenic effects on 3T3-L1 and human preadipocytes. Chemical analyses showed the presence of phenolics in ISE, mainly an appreciable concentration of gallic acid. Ibervillea sonorae exerts its antidiabetic properties by means of hydrosoluble compounds stimulating the glucose uptake in human preadipocytes by a PI3K-independent pathway and without proadipogenic effects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Genome-wide profiling of H3K56 acetylation and transcription factor binding sites in human adipocytes.

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    Kinyui Alice Lo

    Full Text Available The growing epidemic of obesity and metabolic diseases calls for a better understanding of adipocyte biology. The regulation of transcription in adipocytes is particularly important, as it is a target for several therapeutic approaches. Transcriptional outcomes are influenced by both histone modifications and transcription factor binding. Although the epigenetic states and binding sites of several important transcription factors have been profiled in the mouse 3T3-L1 cell line, such data are lacking in human adipocytes. In this study, we identified H3K56 acetylation sites in human adipocytes derived from mesenchymal stem cells. H3K56 is acetylated by CBP and p300, and deacetylated by SIRT1, all are proteins with important roles in diabetes and insulin signaling. We found that while almost half of the genome shows signs of H3K56 acetylation, the highest level of H3K56 acetylation is associated with transcription factors and proteins in the adipokine signaling and Type II Diabetes pathways. In order to discover the transcription factors that recruit acetyltransferases and deacetylases to sites of H3K56 acetylation, we analyzed DNA sequences near H3K56 acetylated regions and found that the E2F recognition sequence was enriched. Using chromatin immunoprecipitation followed by high-throughput sequencing, we confirmed that genes bound by E2F4, as well as those by HSF-1 and C/EBPα, have higher than expected levels of H3K56 acetylation, and that the transcription factor binding sites and acetylation sites are often adjacent but rarely overlap. We also discovered a significant difference between bound targets of C/EBPα in 3T3-L1 and human adipocytes, highlighting the need to construct species-specific epigenetic and transcription factor binding site maps. This is the first genome-wide profile of H3K56 acetylation, E2F4, C/EBPα and HSF-1 binding in human adipocytes, and will serve as an important resource for better understanding adipocyte

  10. Stress of endoplasmic reticulum modulates differentiation and lipogenesis of human adipocytes

    International Nuclear Information System (INIS)

    Koc, Michal; Mayerová, Veronika; Kračmerová, Jana; Mairal, Aline; Mališová, Lucia; Štich, Vladimír; Langin, Dominique; Rossmeislová, Lenka

    2015-01-01

    Background: Adipocytes are cells specialized for storage of neutral lipids. This storage capacity is dependent on lipogenesis and is diminished in obesity. The reason for the decline in lipogenic activity of adipocytes in obesity remains unknown. Recent data show that lipogenesis in liver is regulated by pathways initiated by endoplasmic reticulum stress (ERS). Thus, we aimed at investigating the effect of ERS on lipogenesis in adipose cells. Methods: Preadipocytes were isolated from subcutaneous abdominal adipose tissue from obese volunteers and in vitro differentiated into adipocytes. ERS was induced pharmacologically by thapsigargin (TG) or tunicamycin (TM). Activation of Unfolded Protein Response pathway (UPR) was monitored on the level of eIF2α phosphorylation and mRNA expression of downstream targets of UPR sensors. Adipogenic and lipogenic capacity was evaluated by Oil Red O staining, measurement of incorporation of radio-labelled glucose or acetic acid into lipids and mRNA analysis of adipogenic/lipogenic markers. Results: Exposition of adipocytes to high doses of TG (100 nM) and TM (1 μg/ml) for 1–24 h enhanced expression of several UPR markers (HSPA5, EDEM1, ATF4, XBP1s) and phosphorylation of eIF2α. This acute ERS substantially inhibited expression of lipogenic genes (DGAT2, FASN, SCD1) and glucose incorporation into lipids. Moreover, chronic exposure of preadipocytes to low dose of TG (2.5 nM) during the early phases of adipogenic conversion of preadipocytes impaired both, lipogenesis and adipogenesis. On the other hand, chronic low ERS had no apparent effect on lipogenesis in mature adipocytes. Conclusions: Acute ERS weakened a capacity of mature adipocytes to store lipids and chronic ERS diminished adipogenic potential of preadipocytes. - Highlights: • High intensity ERS inhibits lipogenic capacity of adipocytes. • ERS impairs adipogenesis when present in early stages of adipogenesis. • Lipogenesis in mature adipocytes is not

  11. Stress of endoplasmic reticulum modulates differentiation and lipogenesis of human adipocytes

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    Koc, Michal; Mayerová, Veronika; Kračmerová, Jana [Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague (Czech Republic); Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, CZ-100 00 (Czech Republic); Mairal, Aline [Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague (Czech Republic); Inserm, UMR1048, Obesity Research Laboratory, Institute of Metabolic and Cardiovascular Diseases, 31432 Toulouse, Cedex 4 (France); Mališová, Lucia; Štich, Vladimír [Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague (Czech Republic); Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, CZ-100 00 (Czech Republic); Langin, Dominique [Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague (Czech Republic); Inserm, UMR1048, Obesity Research Laboratory, Institute of Metabolic and Cardiovascular Diseases, 31432 Toulouse, Cedex 4 (France); University of Toulouse, UMR1048, Paul Sabatier University, 31432 Toulouse, Cedex 4 (France); Toulouse University Hospitals, Department of Clinical Biochemistry, 31059 Toulouse, Cedex 9 (France); Rossmeislová, Lenka, E-mail: Lenka.Rossmeislova@lf3.cuni.cz [Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague (Czech Republic); Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, CZ-100 00 (Czech Republic)

    2015-05-08

    Background: Adipocytes are cells specialized for storage of neutral lipids. This storage capacity is dependent on lipogenesis and is diminished in obesity. The reason for the decline in lipogenic activity of adipocytes in obesity remains unknown. Recent data show that lipogenesis in liver is regulated by pathways initiated by endoplasmic reticulum stress (ERS). Thus, we aimed at investigating the effect of ERS on lipogenesis in adipose cells. Methods: Preadipocytes were isolated from subcutaneous abdominal adipose tissue from obese volunteers and in vitro differentiated into adipocytes. ERS was induced pharmacologically by thapsigargin (TG) or tunicamycin (TM). Activation of Unfolded Protein Response pathway (UPR) was monitored on the level of eIF2α phosphorylation and mRNA expression of downstream targets of UPR sensors. Adipogenic and lipogenic capacity was evaluated by Oil Red O staining, measurement of incorporation of radio-labelled glucose or acetic acid into lipids and mRNA analysis of adipogenic/lipogenic markers. Results: Exposition of adipocytes to high doses of TG (100 nM) and TM (1 μg/ml) for 1–24 h enhanced expression of several UPR markers (HSPA5, EDEM1, ATF4, XBP1s) and phosphorylation of eIF2α. This acute ERS substantially inhibited expression of lipogenic genes (DGAT2, FASN, SCD1) and glucose incorporation into lipids. Moreover, chronic exposure of preadipocytes to low dose of TG (2.5 nM) during the early phases of adipogenic conversion of preadipocytes impaired both, lipogenesis and adipogenesis. On the other hand, chronic low ERS had no apparent effect on lipogenesis in mature adipocytes. Conclusions: Acute ERS weakened a capacity of mature adipocytes to store lipids and chronic ERS diminished adipogenic potential of preadipocytes. - Highlights: • High intensity ERS inhibits lipogenic capacity of adipocytes. • ERS impairs adipogenesis when present in early stages of adipogenesis. • Lipogenesis in mature adipocytes is not

  12. High content analysis of differentiation and cell death in human adipocytes.

    Science.gov (United States)

    Doan-Xuan, Quang Minh; Sarvari, Anitta K; Fischer-Posovszky, Pamela; Wabitsch, Martin; Balajthy, Zoltan; Fesus, Laszlo; Bacso, Zsolt

    2013-10-01

    Understanding adipocyte biology and its homeostasis is in the focus of current obesity research. We aimed to introduce a high-content analysis procedure for directly visualizing and quantifying adipogenesis and adipoapoptosis by laser scanning cytometry (LSC) in a large population of cell. Slide-based image cytometry and image processing algorithms were used and optimized for high-throughput analysis of differentiating cells and apoptotic processes in cell culture at high confluence. Both preadipocytes and adipocytes were simultaneously scrutinized for lipid accumulation, texture properties, nuclear condensation, and DNA fragmentation. Adipocyte commitment was found after incubation in adipogenic medium for 3 days identified by lipid droplet formation and increased light absorption, while terminal differentiation of adipocytes occurred throughout day 9-14 with characteristic nuclear shrinkage, eccentric nuclei localization, chromatin condensation, and massive lipid deposition. Preadipocytes were shown to be more prone to tumor necrosis factor alpha (TNFα)-induced apoptosis compared to mature adipocytes. Importantly, spontaneous DNA fragmentation was observed at early stage when adipocyte commitment occurs. This DNA damage was independent from either spontaneous or induced apoptosis and probably was part of the differentiation program. © 2013 International Society for Advancement of Cytometry. Copyright © 2013 International Society for Advancement of Cytometry.

  13. Integration of human adipocyte chromosomal interactions with adipose gene expression prioritizes obesity-related genes from GWAS.

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    Pan, David Z; Garske, Kristina M; Alvarez, Marcus; Bhagat, Yash V; Boocock, James; Nikkola, Elina; Miao, Zong; Raulerson, Chelsea K; Cantor, Rita M; Civelek, Mete; Glastonbury, Craig A; Small, Kerrin S; Boehnke, Michael; Lusis, Aldons J; Sinsheimer, Janet S; Mohlke, Karen L; Laakso, Markku; Pajukanta, Päivi; Ko, Arthur

    2018-04-17

    Increased adiposity is a hallmark of obesity and overweight, which affect 2.2 billion people world-wide. Understanding the genetic and molecular mechanisms that underlie obesity-related phenotypes can help to improve treatment options and drug development. Here we perform promoter Capture Hi-C in human adipocytes to investigate interactions between gene promoters and distal elements as a transcription-regulating mechanism contributing to these phenotypes. We find that promoter-interacting elements in human adipocytes are enriched for adipose-related transcription factor motifs, such as PPARG and CEBPB, and contribute to heritability of cis-regulated gene expression. We further intersect these data with published genome-wide association studies for BMI and BMI-related metabolic traits to identify the genes that are under genetic cis regulation in human adipocytes via chromosomal interactions. This integrative genomics approach identifies four cis-eQTL-eGene relationships associated with BMI or obesity-related traits, including rs4776984 and MAP2K5, which we further confirm by EMSA, and highlights 38 additional candidate genes.

  14. Hyperspectral and differential CARS microscopy for quantitative chemical imaging in human adipocytes

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    Di Napoli, Claudia; Pope, Iestyn; Masia, Francesco; Watson, Peter; Langbein, Wolfgang; Borri, Paola

    2014-01-01

    In this work, we demonstrate the applicability of coherent anti-Stokes Raman scattering (CARS) micro-spectroscopy for quantitative chemical imaging of saturated and unsaturated lipids in human stem-cell derived adipocytes. We compare dual-frequency/differential CARS (D-CARS), which enables rapid imaging and simple data analysis, with broadband hyperspectral CARS microscopy analyzed using an unsupervised phase-retrieval and factorization method recently developed by us for quantitative chemical image analysis. Measurements were taken in the vibrational fingerprint region (1200–2000/cm) and in the CH stretch region (2600–3300/cm) using a home-built CARS set-up which enables hyperspectral imaging with 10/cm resolution via spectral focussing from a single broadband 5 fs Ti:Sa laser source. Through a ratiometric analysis, both D-CARS and phase-retrieved hyperspectral CARS determine the concentration of unsaturated lipids with comparable accuracy in the fingerprint region, while in the CH stretch region D-CARS provides only a qualitative contrast owing to its non-linear behavior. When analyzing hyperspectral CARS images using the blind factorization into susceptibilities and concentrations of chemical components recently demonstrated by us, we are able to determine vol:vol concentrations of different lipid components and spatially resolve inhomogeneities in lipid composition with superior accuracy compared to state-of-the art ratiometric methods. PMID:24877002

  15. Epigenetic Library Screen Identifies Abexinostat as Novel Regulator of Adipocytic and Osteoblastic Differentiation of Human Skeletal (Mesenchymal) Stem Cells

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    Ali, Dalia; Hamam, Rimi; Alfayez, Musaed; Kassem, Moustapha; Aldahmash, Abdullah

    2016-01-01

    The epigenetic mechanisms promoting lineage-specific commitment of human skeletal (mesenchymal or stromal) stem cells (hMSCs) into adipocytes or osteoblasts are still not fully understood. Herein, we performed an epigenetic library functional screen and identified several novel compounds, including abexinostat, which promoted adipocytic and osteoblastic differentiation of hMSCs. Using gene expression microarrays, chromatin immunoprecipitation for H3K9Ac combined with high-throughput DNA sequencing (ChIP-seq), and bioinformatics, we identified several key genes involved in regulating stem cell proliferation and differentiation that were targeted by abexinostat. Concordantly, ChIP-quantitative polymerase chain reaction revealed marked increase in H3K9Ac epigenetic mark on the promoter region of AdipoQ, FABP4, PPARγ, KLF15, CEBPA, SP7, and ALPL in abexinostat-treated hMSCs. Pharmacological inhibition of focal adhesion kinase (PF-573228) or insulin-like growth factor-1R/insulin receptor (NVP-AEW51) signaling exhibited significant inhibition of abexinostat-mediated adipocytic differentiation, whereas inhibition of WNT (XAV939) or transforming growth factor-β (SB505124) signaling abrogated abexinostat-mediated osteogenic differentiation of hMSCs. Our findings provide insight into the understanding of the relationship between the epigenetic effect of histone deacetylase inhibitors, transcription factors, and differentiation pathways governing adipocyte and osteoblast differentiation. Manipulating such pathways allows a novel use for epigenetic compounds in hMSC-based therapies and tissue engineering. Significance This unbiased epigenetic library functional screen identified several novel compounds, including abexinostat, that promoted adipocytic and osteoblastic differentiation of human skeletal (mesenchymal or stromal) stem cells (hMSCs). These data provide new insight into the understanding of the relationship between the epigenetic effect of histone deacetylase

  16. Effects of GSK3 inhibitors on in vitro expansion and differentiation of human adipose-derived stem cells into adipocytes

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    Peraldi Pascal

    2008-02-01

    Full Text Available Abstract Background Multipotent stem cells exist within adipose tissue throughout life. An abnormal recruitment of these adipose precursor cells could participate to hyperplasia of adipose tissue observed in severe obesity or to hypoplasia of adipose tissue observed in lipodystrophy. Therefore, pharmacological molecules that control the pool of stem cells in adipose tissue are of great interest. Glycogen Synthase Kinase (GSK 3 has been previously described as involved in differentiation of preadipose cells and might be a potential therapeutic target to modulate proliferation and differentiation of adipocyte precursors. However, the impact of GSK3 inhibition on human adipose-derived stem cells remained to be investigated. The aim of this study was to investigate GSK3 as a possible target for pharmacological inhibition of stem cell adipogenesis. To reach this goal, we studied the effects of pharmacological inhibitors of GSK3, i.e. lithium chloride (LiCl and BIO on proliferation and adipocyte differentiation of multipotent stem cells derived from human adipose tissue. Results Our results showed that GSK3 inhibitors inhibited proliferation and clonogenicity of human stem cells, strongly suggesting that GSK3 inhibitors could be potent regulators of the pool of adipocyte precursors in adipose tissue. The impact of GSK3 inhibition on differentiation of hMADS cells was also investigated. Adipogenic and osteogenic differentiations were inhibited upon hMADS treatment with BIO. Whereas a chronic treatment was required to inhibit osteogenesis, a treatment that was strictly restricted to the early step of differentiation was sufficient to inhibit adipogenesis. Conclusion These results demonstrated the feasibility of a pharmacological approach to regulate adipose-derived stem cell function and that GSK3 could represent a potential target for controlling adipocyte precursor pool under conditions where fat tissue formation is impaired.

  17. Romidepsin Promotes Osteogenic and Adipocytic Differentiation of Human Mesenchymal Stem Cells through Inhibition of Histondeacetylase Activity

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    Dalia Ali

    2018-01-01

    Full Text Available Bone marrow mesenchymal stem cells (BMSCs are adult multipotent stem cells that can differentiate into mesodermal lineage cells, including adipocytes and osteoblasts. However, the epigenetic mechanisms governing the lineage-specific commitment of BMSCs into adipocytes or osteoblasts are under investigation. Herein, we investigated the epigenetic effect of romidepsin, a small molecule dual inhibitor targeting HDAC1 and HDAC2 identified through an epigenetic library functional screen. BMSCs exposed to romidepsin (5 nM exhibited enhanced adipocytic and osteoblastic differentiation. Global gene expression and signaling pathway analyses of differentially expressed genes revealed a strong enrichment of genes involved in adipogenesis and osteogenesis in romidepsin-treated BMSCs during induction into adipocytes or osteoblasts, respectively. Pharmacological inhibition of FAK signaling during adipogenesis or inhibition of FAK or TGFβ signaling during osteogenesis diminished the biological effects of romidepsin on BMSCs. The results of chromatin immunoprecipitation combined with quantitative polymerase chain reaction indicated a significant increase in H3K9Ac epigenetic markers in the promoter regions of peroxisome proliferator-activated receptor gamma (PPARγ and KLF15 (related to adipogenesis or SP7 (Osterix and alkaline phosphatase (ALP (related to osteogenesis in romidepsin-treated BMSCs. Our data indicated that romidepsin is a novel in vitro modulator of adipocytic and osteoblastic differentiation of BMSCs.

  18. MicroRNAs regulate human adipocyte lipolysis: effects of miR-145 are linked to TNF-α.

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    Silvia Lorente-Cebrián

    Full Text Available MicroRNAs (miRNAs are small non-coding RNAs that regulate gene expression and have multiple effects in various tissues including adipose inflammation, a condition characterized by increased local release of the pro-lipolytic cytokine tumor necrosis factor-alpha (TNF-α. Whether miRNAs regulate adipocyte lipolysis is unknown. We set out to determine whether miRNAs affect adipocyte lipolysis in human fat cells. To this end, eleven miRNAs known to be present in human adipose tissue were over-expressed in human in vitro differentiated adipocytes followed by assessments of TNF-α and glycerol levels in conditioned media after 48 h. Three miRNAs (miR-145, -26a and let-7d modulated both parameters in parallel. However, while miR-26a and let-7d decreased, miR-145 increased both glycerol release and TNF-α secretion. Further studies were focused therefore on miR-145 since this was the only stimulator of lipolysis and TNF-α secretion. Time-course analysis demonstrated that miR-145 over-expression up-regulated TNF-α expression/secretion followed by increased glycerol release. Increase in TNF-α production by miR-145 was mediated via activation of p65, a member of the NF-κB complex. In addition, miR-145 down-regulated the expression of the protease ADAM17, resulting in an increased fraction of membrane bound TNF-α, which is the more biologically active form of TNF-α. MiR-145 overexpression also increased the phosphorylation of activating serine residues in hormone sensitive lipase and decreased the mRNA expression of phosphodiesterase 3B, effects which are also observed upon TNF-α treatment in human adipocytes. We conclude that miR-145 regulates adipocyte lipolysis via multiple mechanisms involving increased production and processing of TNF-α in fat cells.

  19. Metabolic signatures of cultured human adipocytes from metabolically healthy versus unhealthy obese individuals.

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    Anja Böhm

    Full Text Available Among obese subjects, metabolically healthy and unhealthy obesity (MHO/MUHO can be differentiated: the latter is characterized by whole-body insulin resistance, hepatic steatosis, and subclinical inflammation. Aim of this study was, to identify adipocyte-specific metabolic signatures and functional biomarkers for MHO versus MUHO.10 insulin-resistant (IR vs. 10 insulin-sensitive (IS non-diabetic morbidly obese (BMI >40 kg/m2 Caucasians were matched for gender, age, BMI, and percentage of body fat. From subcutaneous fat biopsies, primary preadipocytes were isolated and differentiated to adipocytes in vitro. About 280 metabolites were investigated by a targeted metabolomic approach intracellularly, extracellularly, and in plasma.Among others, aspartate was reduced intracellularly to one third (p = 0.0039 in IR adipocytes, pointing to a relative depletion of citric acid cycle metabolites or reduced aspartate uptake in MUHO. Other amino acids, already known to correlate with diabetes and/or obesity, were identified to differ between MUHO's and MHO's adipocytes, namely glutamine, histidine, and spermidine. Most species of phosphatidylcholines (PCs were lower in MUHO's extracellular milieu, though simultaneously elevated intracellularly, e.g., PC aa C32∶3, pointing to increased PC synthesis and/or reduced PC release. Furthermore, altered arachidonic acid (AA metabolism was found: 15(S-HETE (15-hydroxy-eicosatetraenoic acid; 0 vs. 120pM; p = 0.0014, AA (1.5-fold; p = 0.0055 and docosahexaenoic acid (DHA, C22∶6; 2-fold; p = 0.0033 were higher in MUHO. This emphasizes a direct contribution of adipocytes to local adipose tissue inflammation. Elevated DHA, as an inhibitor of prostaglandin synthesis, might be a hint for counter-regulatory mechanisms in MUHO.We identified adipocyte-inherent metabolic alterations discriminating between MHO and MUHO.

  20. Gene-chip studies of adipogenesis-regulated microRNAs in mouse primary adipocytes and human obesity

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    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

  1. The use of small interfering RNAs to inhibit adipocyte differentiation in human preadipocytes and fetal-femur-derived mesenchymal cells

    International Nuclear Information System (INIS)

    Xu, Y.; Mirmalek-Sani, S.-H.; Yang, X.; Zhang, J.; Oreffo, R.O.C.

    2006-01-01

    RNA interference (RNAi) has been used in functional genomics and offers innovative approaches in the development of novel therapeutics. Human mesenchymal stem cells offer a unique cell source for tissue engineering/regeneration strategies. The current study examined the potential of small interfering RNAs (siRNA) against human peroxisome proliferator activated receptor gamma (PPARγ) to suppress adipocyte differentiation (adipogenesis) in human preadipocytes and fetal-femur-derived mesenchymal cells. Adipogenesis was investigated using cellular and biochemical analysis. Transient transfection with PPARγ-siRNA using a liposomal-based strategy resulted in a significant inhibition of adipogenesis in human preadipocytes and fetal-femur-derived mesenchymal cells, compared to controls (cell, liposomal and negative siRNA). The inhibitory effect of PPARγ-siRNA was supported by testing human PPARγ mRNA and adipogenic associated genes using reverse transcription polymerase chain reaction (RT-PCR) to adiponectin receptor 1 and 2 as well as examination of fatty acid binding protein 3 (FABP 3 ) expression, an adipocyte-specific marker. The current studies indicate that PPARγ-siRNA is a useful tool to study adipogenesis in human cells, with potential applications both therapeutic and in the elucidation of mesenchymal cell differentiation in the modulation of cell differentiation in human mesenchymal cells

  2. Low-dose radiation pretreatment improves survival of human ceiling culture-derived proliferative adipocytes (ccdPAs) under hypoxia via HIF-1 alpha and MMP-2 induction

    International Nuclear Information System (INIS)

    Adachi, Naoki; Kubota, Yoshitaka; Kosaka, Kentarou; Akita, Shinsuke; Sasahara, Yoshitarou; Kira, Tomoe; Kuroda, Masayuki; Mitsukawa, Nobuyuki; Bujo, Hideaki; Satoh, Kaneshige

    2015-01-01

    Poor survival is a major problem of adipocyte transplantation. We previously reported that VEGF and MMPs secreted from transplanted adipocytes are essential for angiogenesis and adipogenesis. Pretreatment with low-dose (5 Gy) radiation (LDR) increased VEGF, MMP-2, and HIF-1 alpha mRNA expression in human ceiling culture-derived proliferative adipocytes (hccdPAs). Gene expression after LDR differed between adipose-derived stem cells (hASCs) and hccdPAs. Pretreatment with LDR improved the survival of hccdPAs under hypoxia, which is inevitable in the early stages after transplantation. Upregulation of VEGF and MMP-2 after LDR in hccdPAs is mediated by HIF-1 alpha expression. Our results suggest that pretreatment with LDR may improve adipocyte graft survival in a clinical setting through upregulation of VEGF and MMP-2 via HIF-1 alpha. - Highlights: • Ceiling culture-derived proliferative adipocytes (ccdPAs) react to radiation. • Low-dose radiation (LDR) pretreatment improves survival of ccdPAs under hypoxia. • Gene expression after LDR differs between ccdPAs and adipose-derived stem cells. • LDR-induced increase in MMP-2 and VEGF is dependent on HIF-1 alpha induction. • LDR pretreatment may improve the adipocyte graft survival rate in clinical settings

  3. Low-dose radiation pretreatment improves survival of human ceiling culture-derived proliferative adipocytes (ccdPAs) under hypoxia via HIF-1 alpha and MMP-2 induction

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Naoki [Department of Plastic Surgery, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-city, Chiba, #260-8677 (Japan); Kubota, Yoshitaka, E-mail: kubota-cbu@umin.ac.jp [Department of Plastic Surgery, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-city, Chiba, #260-8677 (Japan); Kosaka, Kentarou; Akita, Shinsuke; Sasahara, Yoshitarou; Kira, Tomoe [Department of Plastic Surgery, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-city, Chiba, #260-8677 (Japan); Kuroda, Masayuki [Center for Advanced Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-city, Chiba, #260-8677 (Japan); Mitsukawa, Nobuyuki [Department of Plastic Surgery, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-city, Chiba, #260-8677 (Japan); Bujo, Hideaki [Department of Clinical-Laboratory and Experimental-Research Medicine, Toho University, Sakura Medical Center, 564-1 Shimoshizu, Sakura-shi, Chiba, #285-8741 (Japan); Satoh, Kaneshige [Department of Plastic Surgery, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-city, Chiba, #260-8677 (Japan)

    2015-08-07

    Poor survival is a major problem of adipocyte transplantation. We previously reported that VEGF and MMPs secreted from transplanted adipocytes are essential for angiogenesis and adipogenesis. Pretreatment with low-dose (5 Gy) radiation (LDR) increased VEGF, MMP-2, and HIF-1 alpha mRNA expression in human ceiling culture-derived proliferative adipocytes (hccdPAs). Gene expression after LDR differed between adipose-derived stem cells (hASCs) and hccdPAs. Pretreatment with LDR improved the survival of hccdPAs under hypoxia, which is inevitable in the early stages after transplantation. Upregulation of VEGF and MMP-2 after LDR in hccdPAs is mediated by HIF-1 alpha expression. Our results suggest that pretreatment with LDR may improve adipocyte graft survival in a clinical setting through upregulation of VEGF and MMP-2 via HIF-1 alpha. - Highlights: • Ceiling culture-derived proliferative adipocytes (ccdPAs) react to radiation. • Low-dose radiation (LDR) pretreatment improves survival of ccdPAs under hypoxia. • Gene expression after LDR differs between ccdPAs and adipose-derived stem cells. • LDR-induced increase in MMP-2 and VEGF is dependent on HIF-1 alpha induction. • LDR pretreatment may improve the adipocyte graft survival rate in clinical settings.

  4. Extracellular Redox Regulation of Intracellular Reactive Oxygen Generation, Mitochondrial Function and Lipid Turnover in Cultured Human Adipocytes.

    Directory of Open Access Journals (Sweden)

    Albert R Jones

    Full Text Available Many tissues play an important role in metabolic homeostasis and the development of diabetes and obesity. We hypothesized that the circulating redox metabolome is a master metabolic regulatory system that impacts all organs and modulates reactive oxygen species (ROS production, lipid peroxidation, energy production and changes in lipid turnover in many cells including adipocytes.Differentiated human preadipocytes were exposed to the redox couples, lactate (L and pyruvate (P, β-hydroxybutyrate (βOHB and acetoacetate (Acoc, and the thiol-disulfides cysteine/ cystine (Cys/CySS and GSH/GSSG for 1.5-4 hours. ROS measurements were done with CM-H2DCFDA. Lipid peroxidation (LPO was assessed by a modification of the thiobarbituric acid method. Lipolysis was measured as glycerol release. Lipid synthesis was measured as 14C-glucose incorporated into lipid. Respiration was assessed using the SeaHorse XF24 analyzer and the proton leak was determined from the difference in respiration with oligomycin and antimycin A.Metabolites with increasing oxidation potentials (GSSG, CySS, Acoc increased adipocyte ROS. In contrast, P caused a decrease in ROS compared with L. Acoc also induced a significant increase in both LPO and lipid synthesis. L and Acoc increased lipolysis. βOHB increased respiration, mainly due to an increased proton leak. GSSG, when present throughout 14 days of differentiation significantly increased fat accumulation, but not when added later.We demonstrated that in human adipocytes changes in the external redox state impacted ROS production, LPO, energy efficiency, lipid handling, and differentiation. A more oxidized state generally led to increased ROS, LPO and lipid turnover and more reduction led to increased respiration and a proton leak. However, not all of the redox couples were the same suggesting compartmentalization. These data are consistent with the concept of the circulating redox metabolome as a master metabolic regulatory system.

  5. Interaction of differentiated human adipocytes with macrophages leads to trogocytosis and selective IL-6 secretion

    OpenAIRE

    Sárvári, Anitta Kinga; Doan-Xuan, Quang-Minh; Bacsó, Zsolt; Csomós, István; Balajthy, Zoltán; Fésüs, László

    2015-01-01

    Obesity leads to adipose tissue inflammation that is characterized by increased release of proinflammatory molecules and the recruitment of activated immune cells. Although macrophages are present in the highest number among the immune cells in obese adipose tissue, not much is known about their direct interaction with adipocytes. We have introduced an ex vivo experimental system to characterize the cellular interactions and the profile of secreted cytokines in cocultures of macrophages and h...

  6. Effects of selected bioactive food compounds on human white adipocyte function

    DEFF Research Database (Denmark)

    Björk, Christel; Wilhelm, Uta; Mandrup, Susanne

    2016-01-01

    BACKGROUND: Previous studies suggest that intake of specific bioactive compounds may have beneficial clinical effects on adipose tissue partly due to their anti-inflammatory and insulin-sensitizing properties. With the overall aim to contribute to better understanding of the mechanisms of selecte...... uptake albeit only with the combination of DHA and AC. Taken together, our results may link the reported health benefits of the selected bioactives on metabolic disorders such as insulin resistance, hypertension and dyslipidemia to effects on white adipocytes....

  7. Activation of protein kinase A and exchange protein directly activated by cAMP promotes adipocyte differentiation of human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Jia, Bingbing; Madsen, Lise; Petersen, Rasmus Koefoed

    2012-01-01

    ) and exchange protein directly activated by cAMP (Epac) in adipocyte conversion of human mesenchymal stem cells derived from adipose tissue (hMADS). We show that cAMP signaling involving the simultaneous activation of both PKA- and Epac-dependent signaling is critical for this process even in the presence......Human mesenchymal stem cells are primary multipotent cells capable of differentiating into several cell types including adipocytes when cultured under defined in vitro conditions. In the present study we investigated the role of cAMP signaling and its downstream effectors, protein kinase A (PKA...... results emphasize the need for cAMP signaling in concert with treatment with a PPARγ or PPARδ agonist to secure efficient adipocyte differentiation of human hMADS mesenchymal stem cells....

  8. Fibroblast growth factor 21 is elevated in metabolically unhealthy obesity and affects lipid deposition, adipogenesis, and adipokine secretion of human abdominal subcutaneous adipocytes

    Directory of Open Access Journals (Sweden)

    Lucia Berti

    2015-07-01

    Conclusions: The hepatokine FGF21 exerts weak lipogenic and anti-adipogenic actions and marked adiponectin-suppressive and leptin and interleukin-6 release-promoting effects in human differentiating preadipocytes. Together with the higher serum concentrations in MUHO subjects, our findings reveal FGF21 as a circulating factor promoting the development of metabolically unhealthy adipocytes.

  9. Evaluation of the synuclein-y (SNCG) gene as a PPARy target in murine adipocytes, dorsal root ganglia somatosensory neurons, and human adipose tissue

    Science.gov (United States)

    Synuclein-gamma is highly expressed in both adipocytes and peripheral nervous system (PNS) somatosensory neurons. Its mRNA is induced during adipogenesis, increased in obese human white adipose tissue (WAT), may be coordinately regulated with leptin, and is decreased following treatment of murine 3T...

  10. Association of Lipidome Remodeling in the Adipocyte Membrane with Acquired Obesity in Humans

    DEFF Research Database (Denmark)

    Pietilainen, K. H.; Rog, T.; Seppanen-Laakso, T.

    2011-01-01

    Identification of early mechanisms that may lead from obesity towards complications such as metabolic syndrome is of great interest. Here we performed lipidomic analyses of adipose tissue in twin pairs discordant for obesity but still metabolically compensated. In parallel we studied more evolved...... of ethanolamine plasmalogens containing arachidonic acid. Information gathered from these experimental groups was used for molecular dynamics simulations of lipid bilayers combined with dependency network analysis of combined clinical, lipidomics, and gene expression data. The simulations suggested...... also show by in vitro Elovl6 knockdown that the lipid network regulating the observed remodeling may be amenable to genetic modulation. Together, our novel approach suggests a physiological mechanism by which adaptation of adipocyte membranes to adipose tissue expansion associates with positive energy...

  11. MicroRNA-4739 regulates osteogenic and adipocytic differentiation of immortalized human bone marrow stromal cells via targeting LRP3

    Directory of Open Access Journals (Sweden)

    Mona Elsafadi

    2017-04-01

    Full Text Available Understanding the regulatory networks underlying lineage differentiation and fate determination of human bone marrow stromal cells (hBMSC is a prerequisite for their therapeutic use. The goal of the current study was to unravel the novel role of the low-density lipoprotein receptor-related protein 3 (LRP3 in regulating the osteogenic and adipogenic differentiation of immortalized hBMSCs. Gene expression profiling revealed significantly higher LRP3 levels in the highly osteogenic hBMSC clone imCL1 than in the less osteogenic clone imCL2, as well as a significant upregulation of LRP3 during the osteogenic induction of the imCL1 clone. Data from functional and gene expression assays demonstrated the role of LRP3 as a molecular switch promoting hBMSC lineage differentiation into osteoblasts and inhibiting differentiation into adipocytes. Interestingly, microRNA (miRNA expression profiling identified miR-4739 as the most under-represented miRNA (−36.11 fold in imCL1 compared to imCL2. The TargetScan prediction algorithm, combined with functional and biochemical assays, identified LRP3 mRNA as a novel target of miR-4739, with a single potential binding site for miR-4739 located in the LRP3 3′ UTR. Regulation of LRP3 expression by miR-4739 was subsequently confirmed by qRT-PCR, western blotting, and luciferase assays. Over-expression of miR-4739 mimicked the effects of LRP3 knockdown on promoting adipogenic and suppressing osteogenic differentiation of hBMSCs. Hence, we report for the first time a novel biological role for the LRP3/hsa-miR-4739 axis in balancing osteogenic and adipocytic differentiation of hBMSCs. Our data support the potential utilization of miRNA-based therapies in regenerative medicine.

  12. Association of lipidome remodeling in the adipocyte membrane with acquired obesity in humans.

    Directory of Open Access Journals (Sweden)

    Kirsi H Pietiläinen

    2011-06-01

    Full Text Available Identification of early mechanisms that may lead from obesity towards complications such as metabolic syndrome is of great interest. Here we performed lipidomic analyses of adipose tissue in twin pairs discordant for obesity but still metabolically compensated. In parallel we studied more evolved states of obesity by investigating a separated set of individuals considered to be morbidly obese. Despite lower dietary polyunsaturated fatty acid intake, the obese twin individuals had increased proportions of palmitoleic and arachidonic acids in their adipose tissue, including increased levels of ethanolamine plasmalogens containing arachidonic acid. Information gathered from these experimental groups was used for molecular dynamics simulations of lipid bilayers combined with dependency network analysis of combined clinical, lipidomics, and gene expression data. The simulations suggested that the observed lipid remodeling maintains the biophysical properties of lipid membranes, at the price, however, of increasing their vulnerability to inflammation. Conversely, in morbidly obese subjects, the proportion of plasmalogens containing arachidonic acid in the adipose tissue was markedly decreased. We also show by in vitro Elovl6 knockdown that the lipid network regulating the observed remodeling may be amenable to genetic modulation. Together, our novel approach suggests a physiological mechanism by which adaptation of adipocyte membranes to adipose tissue expansion associates with positive energy balance, potentially leading to higher vulnerability to inflammation in acquired obesity. Further studies will be needed to determine the cause of this effect.

  13. The activity of the endocannabinoid metabolising enzyme fatty acid amide hydrolase in subcutaneous adipocytes correlates with BMI in metabolically healthy humans

    Directory of Open Access Journals (Sweden)

    Alexander Stephen PH

    2011-08-01

    Full Text Available Abstract Background The endocannabinoid system (ECS is a ubiquitously expressed signalling system, with involvement in lipid metabolism and obesity. There are reported changes in obesity of blood concentrations of the endocannabinoids anandamide (AEA and 2-arachidonoylglcyerol (2-AG, and of adipose tissue expression levels of the two key catabolic enzymes of the ECS, fatty acid amide hydrolase (FAAH and monoacylglycerol lipase (MGL. Surprisingly, however, the activities of these enzymes have not been assayed in conditions of increasing adiposity. The aim of the current study was to investigate whether FAAH and MGL activities in human subcutaneous adipocytes are affected by body mass index (BMI, or other markers of adiposity and metabolism. Methods Subcutaneous abdominal mature adipocytes, fasting blood samples and anthropometric measurements were obtained from 28 metabolically healthy subjects representing a range of BMIs. FAAH and MGL activities were assayed in mature adipocytes using radiolabelled substrates. Serum glucose, insulin and adipokines were determined using ELISAs. Results MGL activity showed no relationship with BMI or other adiposity indices, metabolic markers (fasting serum insulin or glucose or serum adipokine levels (adiponectin, leptin or resistin. In contrast, FAAH activity in subcutaneous adipocytes correlated positively with BMI and waist circumference, but not with skinfold thickness, metabolic markers or serum adipokine levels. Conclusions In this study, novel evidence is provided that FAAH activity in subcutaneous mature adipocytes increases with BMI, whereas MGL activity does not. These findings support the hypothesis that some components of the ECS are upregulated with increasing adiposity in humans, and that AEA and 2-AG may be regulated differently.

  14. Analysis for apoptosis and necrosis on adipocytes, stromal vascular fraction, and adipose-derived stem cells in human lipoaspirates after liposuction.

    Science.gov (United States)

    Wang, Wei Z; Fang, Xin-Hua; Williams, Shelley J; Stephenson, Linda L; Baynosa, Richard C; Wong, Nancy; Khiabani, Kayvan T; Zamboni, William A

    2013-01-01

    Adipose-derived stem cells have become the most studied adult stem cells. The authors examined the apoptosis and necrosis rates for adipocyte, stromal vascular fraction, and adipose-derived stem cells in fresh human lipoaspirates. Human lipoaspirate (n = 8) was harvested using a standard liposuction technique. Stromal vascular fraction cells were separated from adipocytes and cultured to obtain purified adipose-derived stem cells. A panel of stem cell markers was used to identify the surface phenotypes of cultured adipose-derived stem cells. Three distinct stem cell subpopulations (CD90/CD45, CD105/CD45, and CD34/CD31) were selected from the stromal vascular fraction. Apoptosis and necrosis were determined by annexin V/propidium iodide assay and analyzed by flow cytometry. The cultured adipose-derived stem cells demonstrated long-term proliferation and differentiation evidenced by cell doubling time and positive staining with oil red O and alkaline phosphatase. Isolated from lipoaspirates, adipocytes exhibited 19.7 ± 3.7 percent apoptosis and 1.1 ± 0.3 percent necrosis; stromal vascular fraction cells revealed 22.0 ± 6.3 percent of apoptosis and 11.2 ± 1.9 percent of necrosis; stromal vascular fraction cells had a higher rate of necrosis than adipocytes (p vascular fraction cells, 51.1 ± 3.7 percent expressed CD90/CD45, 7.5 ± 1.0 percent expressed CD105/CD45, and 26.4 ± 3.8 percent expressed CD34/CD31. CD34/CD31 adipose-derived stem cells had lower rates of apoptosis and necrosis compared with CD105/CD45 adipose-derived stem cells (p necrosis than adipocytes. However, the extent of apoptosis and necrosis was significantly different among adipose-derived stem cell subpopulations.

  15. An intensified esterification process of palm oil fatty acid distillate catalyzed by delipidated rice bran lipase.

    Science.gov (United States)

    Chong, Fui Chin; Tey, Beng Ti; Dom, Zanariah Mohd; Ibrahim, Nordin; Rahman, Russly Abd; Ling, Tau Chuan

    2006-09-07

    An intensified esterification process was operated by circulating 10 l of reaction mixtures, consisting of palm oil fatty acid distillate (PFAD) and glycerol in hexane, through a packed-bed reactor (PBR) filled with 10 kg of delipidated rice bran lipase (RBL). The influence of the process parameters, such as reaction temperature and type of water-removal agent, on the performance of this intensified esterification process were investigated. The highest degree of esterification (61%) was achieved at a reaction temperature of 65 masculineC, using silica gels as the water-removal agent. Thin-layer chromatography (TLC) analysis showed that the major composition of the esterified product was diacylglycerol.

  16. Inflammation and insulin resistance induced by trans-10, cis-12 conjugated linoleic acid depend on intracellular calcium levels in primary cultures of human adipocytes

    DEFF Research Database (Denmark)

    Kennedy, Arion; Martinez, Kristina; Chung, Soonkyu

    2010-01-01

    We previously demonstrated that trans-10, cis-12 (10,12) conjugated linoleic acid (CLA) induced inflammation and insulin resistance in primary human adipocytes by activating nuclear factor kappaB (NFkappaB) and extracellular signal-related kinase (ERK) signaling. In this study, we demonstrated...... that the initial increase in intracellular calcium ([Ca2+]i) mediated by 10,12 CLA was attenuated by TMB-8, an inhibitor of calcium release from the endoplasmic reticulum (ER), by BAPTA, an intracellular calcium chelator, and by D609, a phospholipase C (PLC) inhibitor. Moreover, BAPTA, TMB-8, and D609 attenuated......, and suppression of peroxisome proliferator activated receptor gamma protein levels and insulin-stimulated glucose uptake. These data suggest that 10,12 CLA increases inflammation and insulin resistance in human adipocytes, in part by increasing [Ca2+]i levels, particularly calcium from the ER....

  17. Activation of classical brown adipocytes in the adult human perirenal depot is highly correlated with PRDM16-EHMT1 complex expression.

    Directory of Open Access Journals (Sweden)

    Gaku Nagano

    Full Text Available Brown fat generates heat to protect against cold and obesity. Adrenergic stimulation activates the thermogenic program of brown adipocytes. Although the bioactivity of brown adipose tissue in adult humans had been assumed to very low, several studies using positron emission tomography-computed tomography (PET-CT have detected bioactive brown adipose tissue in adult humans under cold exposure. In this study, we collected adipose tissues obtained from the perirenal regions of adult patients with pheochromocytoma (PHEO or non-functioning adrenal tumors (NF. We demonstrated that perirenal brown adipocytes were activated in adult patients with PHEO. These cells had the molecular characteristics of classical brown fat rather than those of beige/brite fat. Expression of brown adipose tissue markers such as uncoupling protein 1 (UCP1 and cell death-inducing DFFA-like effector A (CIDEA was highly correlated with the amounts of PRD1-BF-1-RIZ1 homologous domain-containing protein-16 (PRDM16 - euchromatic histone-lysine N-methyltransferase 1 (EHMT1 complex, the key transcriptional switch for brown fat development. These results provide novel insights into the reconstruction of human brown adipocytes and their therapeutic application against obesity and its complications such as type 2 diabetes.

  18. Spexin is a Novel Human Peptide that Reduces Adipocyte Uptake of Long Chain Fatty Acids and Causes Weight Loss in Rodents with Diet-induced Obesity*

    Science.gov (United States)

    Walewski, José L.; Ge, Fengxia; Lobdell, Harrison; Levin, Nancy; Schwartz, Gary J.; Vasselli, Joseph; Pomp, Afons; Dakin, Gregory; Berk, Paul D.

    2014-01-01

    Objective Microarray studies identified Ch12:orf39 (Spexin) as the most dysregulated gene in obese human fat. Therefore we examined its role in obesity pathogenesis. Design and Methods Spexin effects on food intake, meal patterns, body weight, Respiratory Exchange Ratio (RER), and locomotor activity were monitored electronically in C57BL/6J mice or Wistar rats with dietary-induced obesity (DIO). Its effects on adipocyte [3H]-oleate uptake were determined. Results In humans, Spexin gene expression was down-regulated 14.9-fold in obese omental and subcutaneous fat. Circulating Spexin changed in parallel, correlating (r = −0.797) with Leptin. In rats, Spexin (35 μg/kg/day s.c) reduced caloric intake ~32% with corresponding weight loss. Meal patterns were unaffected. In mice, Spexin (25 μg/kg/day i.p.) significantly reduced the RER at night, and increased locomotion. Spexin incubation in vitro significantly inhibited facilitated fatty acid (FA) uptake into DIO mouse adipocytes. Conditioned taste aversion testing (70μg/kg/day i.p.) demonstrated no aversive Spexin effects. Conclusions Spexin gene expression is markedly down-regulated in obese human fat. The peptide produces weight loss in DIO rodents. Its effects on appetite and energy regulation are presumably central; those on adipocyte FA uptake appear direct and peripheral. Spexin is a novel hormone involved in weight regulation, with potential for obesity therapy. PMID:24550067

  19. Spexin is a novel human peptide that reduces adipocyte uptake of long chain fatty acids and causes weight loss in rodents with diet-induced obesity.

    Science.gov (United States)

    Walewski, José L; Ge, Fengxia; Lobdell, Harrison; Levin, Nancy; Schwartz, Gary J; Vasselli, Joseph R; Pomp, Afons; Dakin, Gregory; Berk, Paul D

    2014-07-01

    Microarray studies identified Ch12:orf39 (Spexin) as the most down-regulated gene in obese human fat. Therefore, we examined its role in obesity pathogenesis. Spexin effects on food intake, meal patterns, body weight, respiratory exchange ratio (RER), and locomotor activity were monitored electronically in C57BL/6J mice or Wistar rats with diet-induced obesity (DIO). Its effects on adipocyte [(3)H]-oleate uptake were determined. In humans, Spexin gene expression was down-regulated 14.9-fold in obese omental and subcutaneous fat. Circulating Spexin changed in parallel, correlating (r = -0.797) with Leptin. In rats, Spexin (35 µg/kg/day SC) reduced caloric intake ∼32% with corresponding weight loss. Meal patterns were unaffected. In mice, Spexin (25 µg/kg/day IP) significantly reduced the RER at night, and increased locomotion. Spexin incubation in vitro significantly inhibited facilitated fatty acid (FA) uptake into DIO mouse adipocytes. Conditioned taste aversion testing (70 µg/kg/day IP) demonstrated no aversive Spexin effects. Spexin gene expression is markedly down-regulated in obese human fat. The peptide produces weight loss in DIO rodents. Its effects on appetite and energy regulation are presumably central; those on adipocyte FA uptake appear direct and peripheral. Spexin is a novel hormone involved in weight regulation, with potential for obesity therapy. Copyright © 2014 The Obesity Society.

  20. On the formation of lipid droplets in human adipocytes: the organization of the perilipin-vimentin cortex.

    Directory of Open Access Journals (Sweden)

    Hans Heid

    Full Text Available We report on the heterogeneity and diversity of lipid droplets (LDs in early stages of adipogenesis by elucidating the cell and molecular biology of amphiphilic and cytoskeletal proteins regulating and stabilizing the generation of LDs in human adipose cells. A plethora of distinct and differently sized LDs was detected by a brief application of adipocyte differentiation medium and additional short treatment with oleic acid. Using these cells and highly specific antibodies for LD-binding proteins of the perilipin (PLIN family, we could distinguish between endogenously derived LDs (endogenous LDs positive for perilipin from exogenously induced LDs (exogenous LDs positive for adipophilin, TIP47 and S3-12. Having optimized these stimulation conditions, we used early adipogenic differentiation stages to investigate small-sized LDs and concentrated on LD-protein associations with the intermediate-sized filament (IF vimentin. This IF protein was described earlier to surround lipid globules, showing spherical, cage-like structures. Consequently - by biochemical methods, by immunofluorescence microscopy and by electron- and immunoelectron microscopy - various stages of emerging lipid globules were revealed with perilipin as linking protein between LDs and vimentin. For this LD-PLIN-Vimentin connection, a model is now proposed, suggesting an interaction of proteins via opposed charged amino acid domains respectively. In addition, multiple sheaths of smooth endoplasmic reticulum cisternae surrounding concentrically nascent LDs are shown. Based on our comprehensive localization studies we present and discuss a novel pathway for the LD formation.

  1. Delipidation of mammalian Atg8-family proteins by each of the four ATG4 proteases.

    Science.gov (United States)

    Kauffman, Karlina J; Yu, Shenliang; Jin, Jiaxin; Mugo, Brian; Nguyen, Nathan; O'Brien, Aidan; Nag, Shanta; Lystad, Alf Håkon; Melia, Thomas J

    2018-04-10

    During macroautophagy/autophagy, mammalian Atg8-family proteins undergo 2 proteolytic processing events. The first exposes a COOH-terminal glycine used in the conjugation of these proteins to lipids on the phagophore, the precursor to the autophagosome, whereas the second releases the lipid. The ATG4 family of proteases drives both cleavages, but how ATG4 proteins distinguish between soluble and lipid-anchored Atg8 proteins is not well understood. In a fully reconstituted delipidation assay, we establish that the physical anchoring of mammalian Atg8-family proteins in the membrane dramatically shifts the way ATG4 proteases recognize these substrates. Thus, while ATG4B is orders of magnitude faster at processing a soluble unprimed protein, all 4 ATG4 proteases can be activated to similar enzymatic activities on lipid-attached substrates. The recognition of lipidated but not soluble substrates is sensitive to a COOH-terminal LIR motif both in vitro and in cells. We suggest a model whereby ATG4B drives very fast priming of mammalian Atg8 proteins, whereas delipidation is inherently slow and regulated by all ATG4 homologs.

  2. Mining microarray datasets in nutrition: expression of the GPR120 (n-3 fatty acid receptor/sensor) gene is down-regulated in human adipocytes by macrophage secretions.

    Science.gov (United States)

    Trayhurn, Paul; Denyer, Gareth

    2012-01-01

    Microarray datasets are a rich source of information in nutritional investigation. Targeted mining of microarray data following initial, non-biased bioinformatic analysis can provide key insight into specific genes and metabolic processes of interest. Microarrays from human adipocytes were examined to explore the effects of macrophage secretions on the expression of the G-protein-coupled receptor (GPR) genes that encode fatty acid receptors/sensors. Exposure of the adipocytes to macrophage-conditioned medium for 4 or 24 h had no effect on GPR40 and GPR43 expression, but there was a marked stimulation of GPR84 expression (receptor for medium-chain fatty acids), the mRNA level increasing 13·5-fold at 24 h relative to unconditioned medium. Importantly, expression of GPR120, which encodes an n-3 PUFA receptor/sensor, was strongly inhibited by the conditioned medium (15-fold decrease in mRNA at 24 h). Macrophage secretions have major effects on the expression of fatty acid receptor/sensor genes in human adipocytes, which may lead to an augmentation of the inflammatory response in adipose tissue in obesity.

  3. Relative shrinkage of adipocytes by paraffin in proportion to plastic embedding in human adipose tissue before and after weight loss.

    Science.gov (United States)

    Verhoef, Sanne P M; van Dijk, Paul; Westerterp, Klaas R

    2013-01-01

    Adipocyte size is a major modulator of endocrine functioning of adipose tissue and methods allowing accurate determination of adipocyte size are important to study energy metabolism. The aim of this study was to assess the relative shrinkage of adipocytes before and after weight loss by comparing adipose tissue from the same subjects embedded in paraffin and plastic. 18 healthy subjects (5 males and 13 females) aged 20-50 y with a BMI of 28-38 kg/m² followed a very low energy diet for 8 weeks. Adipose tissue biopsies were taken prior to and after weight loss and were processed for paraffin and plastic sections. Parameters of adipocyte size were determined with computer image analysis. Mean adipocyte size was smaller in paraffin compared to plastic embedded tissue both before (66 ± 4 vs. 103 ± 5 μm, P paraffin embedded tissue in proportion to plastic embedded tissue was not significantly different before and after weight loss (73 and 69%, respectively). Shrinkage due to the type of embedding of the adipose tissue can be ignored when comparing before and after weight loss. Plastic embedding of adipose tissue provides more accurate and sensitive results. © 2013 Asian Oceanian Association for the Study of Obesity . Published by Elsevier Ltd. All rights reserved.

  4. Genome-wide analysis of gene expression during adipogenesis in human adipose-derived stromal cells reveals novel patterns of gene expression during adipocyte differentiation

    Directory of Open Access Journals (Sweden)

    Melvin Anyasi Ambele

    2016-05-01

    Full Text Available We have undertaken an in-depth transcriptome analysis of adipogenesis in human adipose-derived stromal cells (ASCs induced to differentiate into adipocytes in vitro. Gene expression was assessed on days 1, 7, 14 and 21 post-induction and genes differentially expressed numbered 128, 218, 253 and 240 respectively. Up-regulated genes were associated with blood vessel development, leukocyte migration, as well as tumor growth, invasion and metastasis. They also shared common pathways with certain obesity-related pathophysiological conditions. Down-regulated genes were enriched for immune response processes. KLF15, LMO3, FOXO1 and ZBTB16 transcription factors were up-regulated throughout the differentiation process. CEBPA, PPARG, ZNF117, MLXIPL, MMP3 and RORB were up-regulated only on days 14 and 21, which coincide with the maturation of adipocytes and could possibly serve as candidates for controlling fat accumulation and the size of mature adipocytes. In summary, we have identified genes that were up-regulated only on days 1 and 7 or days 14 and 21 that could serve as potential early and late-stage differentiation markers.

  5. A biomimetic hydrogel functionalized with adipose ECM components as a microenvironment for the 3D culture of human and murine adipocytes.

    Science.gov (United States)

    Louis, Fiona; Pannetier, Pauline; Souguir, Zied; Le Cerf, Didier; Valet, Philippe; Vannier, Jean-Pierre; Vidal, Guillaume; Demange, Elise

    2017-08-01

    The lack of relevant in vitro models for adipose tissue makes necessary the development of a more physiological environment providing spatial and chemical cues for the effective maturation of adipocytes. We developed a biofunctionalized hydrogel with components of adipose extracellular matrix: collagen I, collagen VI, and the cell binding domain of fibronectin and we compared it to usual 2D cultures on plastic plates. This scaffold allowed 3D culture of mature adipocytes from the preadipocytes cell lines 3T3-L1 and 3T3-F442A, as well as primary Human White Preadipocytes (HWP), acquiring in vivo-like organization, with spheroid shaped adipocytes forming multicellular aggregates. The size of these aggregates increased with time up to 120 μm in diameter after 4 weeks of maturation, with good viability. Significantly higher lipogenic activity (up to 20-fold at day 28 for HWP cultures) and differentiation rates were also observed compared to 2D. Gene expression analyses highlighted earlier differentiation and complete maturation of 3D HWP compared to 2D, reinforced by the expression of Perilipin protein after 21 days of nutrition. This increase in adipocytes phenotypic and genotypic markers made this scaffold-driven culture as a robust adipose 3D model. Retinoic acid inhibition of lipogenesis in HWP or isoprenalin and caffeine induction of lipolysis performed on mouse 3T3-F442A cells, showed higher doses of molecules than typically used in 2D, underlying the physiologic relevance of this 3D culture system. Biotechnol. Bioeng. 2017;114: 1813-1824. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  6. G0/G1 switch gene-2 regulates human adipocyte lipolysis by affecting activity and localization of adipose triglyceride lipase

    NARCIS (Netherlands)

    Schweiger, M.; Paar, M.; Eder, C.; Brandis, J.; Moser, E.; Gorkiewisz, G.; Grond, S.; Radner, F.P.W.; Cerk, I.; Cornaciu, I.; Oberer, M.; Kersten, A.H.; Zechner, R.; Zimmermann, M.B.; Lass, A.

    2012-01-01

    The hydrolysis of triglycerides in adipocytes, termed lipolysis, provides free fatty acids as energy fuel. Murine lipolysis largely depends on the activity of adipose triglyceride lipase (ATGL)5, which is regulated by two proteins annotated as comparative gene identification-58 (CGI-58) and G0/G1

  7. Maintenance of osteoblastic and adipocytic differentiation potential with age and osteoporosis in human marrow stromal cell cultures

    DEFF Research Database (Denmark)

    Justesen, J; Dokkedahl, Karin Stenderup; Eriksen, E F

    2002-01-01

    Osteoblasts and adipocytes share a common precursor cell in the bone marrow stroma, termed marrow stromal cell (MSC). As the volume of bone adipose tissue increases in vivo with age, we hypothesized that decreased bone formation observed during aging and in patients with osteoporosis (OP) is the ...

  8. An Intensified Esterification Process of Palm Oil Fatty Acid Distillate Catalyzed by Delipidated Rice Bran Lipase

    Directory of Open Access Journals (Sweden)

    Fui Chin Chong

    2006-01-01

    Full Text Available An intensified esterification process was operated by circulating 10 l of reaction mixtures, consisting of palm oil fatty acid distillate (PFAD and glycerol in hexane, through a packed-bed reactor (PBR filled with 10 kg of delipidated rice bran lipase (RBL. The influence of the process parameters, such as reaction temperature and type of water-removal agent, on the performance of this intensified esterification process were investigated. The highest degree of esterification (61% was achieved at a reaction temperature of 65°C, using silica gels as the water-removal agent. Thin-layer chromatography (TLC analysis showed that the major composition of the esterified product was diacylglycerol.

  9. Fibroblast growth factor 21 improves insulin sensitivity and synergizes with insulin in human adipose stem cell-derived (hASC adipocytes.

    Directory of Open Access Journals (Sweden)

    Darwin V Lee

    Full Text Available Fibroblast growth factor 21 (FGF21 has evolved as a major metabolic regulator, the pharmacological administration of which causes weight loss, insulin sensitivity and glucose control in rodents and humans. To understand the molecular mechanisms by which FGF21 exerts its metabolic effects, we developed a human in vitro model of adipocytes to examine crosstalk between FGF21 and insulin signaling. Human adipose stem cell-derived (hASC adipocytes were acutely treated with FGF21 alone, insulin alone, or in combination. Insulin signaling under these conditions was assessed by measuring tyrosine phosphorylation of insulin receptor (InsR, insulin receptor substrate-1 (IRS-1, and serine 473 phosphorylation of Akt, followed by a functional assay using 14C-2-deoxyglucose [14C]-2DG to measure glucose uptake in these cells. FGF21 alone caused a modest increase of glucose uptake, but treatment with FGF21 in combination with insulin had a synergistic effect on glucose uptake in these cells. The presence of FGF21 also effectively lowered the insulin concentration required to achieve the same level of glucose uptake compared to the absence of FGF21 by 10-fold. This acute effect of FGF21 on insulin signaling was not due to IR, IGF-1R, or IRS-1 activation. Moreover, we observed a substantial increase in basal S473-Akt phosphorylation by FGF21 alone, in contrast to the minimal shift in basal glucose uptake. Taken together, our data demonstrate that acute co-treatment of hASC-adipocytes with FGF21 and insulin can result in a synergistic improvement in glucose uptake. These effects were shown to occur at or downstream of Akt, or separate from the canonical insulin signaling pathway.

  10. IL-33 stimulates expression of the GPR84 (EX33) fatty acid receptor gene and of cytokine and chemokine genes in human adipocytes.

    Science.gov (United States)

    Zaibi, Mohamed S; Kępczyńska, Małgorzata A; Harikumar, Parvathy; Alomar, Suliman Y; Trayhurn, Paul

    2018-05-15

    Expression of GPCR fatty acid sensor/receptor genes in adipocytes is modulated by inflammatory mediators, particularly IL-1β. In this study we examined whether the IL-1 gene superfamily member, IL-33, also regulates expression of the fatty acid receptor genes in adipocytes. Human fat cells, differentiated from preadipocytes, were incubated with IL-33 at three different dose levels for 3 or 24 h and mRNA measured by qPCR. Treatment with IL-33 induced a dose-dependent increase in GPR84 mRNA at 3 h, the level with the highest dose being 13.7-fold greater than in controls. Stimulation of GPR84 expression was transitory; the mRNA level was not elevated at 24 h. In contrast to GPR84, IL-33 had no effect on GPR120 expression. IL-33 markedly stimulated expression of the IL1B, CCL2, IL6, CXCL2 and CSF3 genes, but there was no effect on ADIPOQ expression. The largest effect was on CSF3, the mRNA level of which increased 183-fold over controls at 3 h with the highest dose of IL-33; there was a parallel increase in the secretion of G-CSF protein into the medium. It is concluded that in human adipocytes IL-33, which is synthesised in adipose tissue, has a strong stimulatory effect on the expression of cytokine and chemokine genes, particularly CSF3, and on the expression of GPR84, a pro-inflammatory fatty acid receptor. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. The epigenetic modifiers 5-aza-2'-deoxycytidine and trichostatin A influence adipocyte differentiation in human mesenchymal stem cells

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    J. Zych

    2013-05-01

    Full Text Available Epigenetic mechanisms such as DNA methylation and histone modification are important in stem cell differentiation. Methylation is principally associated with transcriptional repression, and histone acetylation is correlated with an active chromatin state. We determined the effects of these epigenetic mechanisms on adipocyte differentiation in mesenchymal stem cells (MSCs derived from bone marrow (BM-MSCs and adipose tissue (ADSCs using the chromatin-modifying agents trichostatin A (TSA, a histone deacetylase inhibitor, and 5-aza-2′-deoxycytidine (5azadC, a demethylating agent. Subconfluent MSC cultures were treated with 5, 50, or 500 nM TSA or with 1, 10, or 100 µM 5azadC for 2 days before the initiation of adipogenesis. The differentiation was quantified and expression of the adipocyte genes PPARG and FABP4 and of the anti-adipocyte gene GATA2 was evaluated. TSA decreased adipogenesis, except in BM-MSCs treated with 5 nM TSA. Only treatment with 500 nM TSA decreased cell proliferation. 5azadC treatment decreased proliferation and adipocyte differentiation in all conditions evaluated, resulting in the downregulation of PPARG and FABP4 and the upregulation of GATA2. The response to treatment was stronger in ADSCs than in BM-MSCs, suggesting that epigenetic memories may differ between cells of different origins. As epigenetic signatures affect differentiation, it should be possible to direct the use of MSCs in cell therapies to improve process efficiency by considering the various sources available.

  12. Role of C/EBPβ-LAP and C/EBPβ-LIP in early adipogenic differentiation of human white adipose-derived progenitors and at later stages in immature adipocytes.

    Science.gov (United States)

    Lechner, Stefan; Mitterberger, Maria C; Mattesich, Monika; Zwerschke, Werner

    2013-01-01

    We investigated the role of the major isoforms of CCAAT enhancer binding protein β (C/EBPβ), C/EBPβ-LAP and C/EBPβ-LIP, in adipogenesis of human white adipose-derived stromal/progenitor cells (ASC). C/EBPβ gene expression was transiently induced early in adipogenesis. At later stages, in immature adipocytes, the C/EBPβ mRNA and protein levels declined. The C/EBPβ-LIP protein steady-state level decreased considerably stronger than the C/EBPβ-LAP level and the C/EBPβ-LIP half-life was significantly shorter than the C/EBPβ-LAP half-life. The turn-over of both C/EBPβ-isoforms was regulated by ubiquitin/proteasome-dependent degradation. These data suggest that the protein stability of the C/EBPβ-isoforms is differentially regulated in the course of adipogenesis and in immature adipocytes. Constitutive overexpression of C/EBPβ-LIP had antiadipogenic activity in human ASC. C/EBPβ-LAP, which promotes adipogenesis in mouse 3T3-L1 preadipocytes by directly activating expression of the adipogenic keyregulator PPARγ2, induced the expression of PPARγ2 and of the adipocyte differentiation gene product FABP4 in confluent ASC in the absence of adipogenic hormones. At later stages after hormone cocktail-induced adipogenesis, in immature adipocytes, constitutive overexpression of C/EBPβ-LAP led to reduced expression of PPARγ2 and FABP4, C/EBPα expression was downregulated and the expression of the adipocyte differentiation gene products adiponectin and leptin was impaired. These findings suggest that constitutive overexpression of C/EBPβ-LAP induces adipogenesis in human ASC and negatively regulates the expression of adipogenic regulators and certain adipocyte differentiation gene products in immature adipocytes. We conclude the regulation of both C/EBPβ gene expression and C/EBPβ-LIP and C/EBPβ-LAP protein turn-over plays an important role for the expression of adipogenic regulators and/or adipocyte differentiation genes in early adipogenic differentiation of

  13. B Lymphocyte Stimulator (BLyS is expressed in human adipocytes in vivo and is related to obesity but not to insulin resistance.

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    Nike Müller

    Full Text Available Inflammation and metabolism have been shown to be evolutionary linked and increasing evidence exists that pro-inflammatory factors are involved in the pathogenesis of obesity and type 2 diabetes. Until now, most data suggest that within adipose tissue these factors are secreted by cells of the innate immune system, e. g. macrophages. In the present study we demonstrate that B lymphocyte stimulator (BLyS is increased in human obesity. In contrast to several pro-inflammatory factors, we found the source of BLyS in human adipose tissue to be the adipocytes rather than immune cells. In grade 3 obese human subjects, expression of BLyS in vivo in adipose tissue is significantly increased (p<0.001. Furthermore, BLyS serum levels are elevated in grade 3 human obesity (862.5+222.0 pg/ml vs. 543.7+60.7 pg/ml in lean controls, p<0.001 and are positively correlated to the BMI (r = 0.43, p<0.0002. In the present study, bariatric surgery significantly altered serum BLyS concentrations. In contrast, weight loss due to a very-low-calorie-formula-diet (800 kcal/d had no such effect. To examine metabolic activity of BLyS, in a translational research approach, insulin sensitivity was measured in human subjects in vivo before and after treatment with the human recombinant anti-BLyS antibody belimumab. Since BLyS is known to promote B-cell proliferation and immunoglobulin secretion, the present data suggest that adipocytes of grade 3 obese human subjects are able to activate the adaptive immune system, suggesting that in metabolic inflammation in humans both, innate and adaptive immunity, are of pathophysiological relevance.

  14. Brown-Like Adipocyte Progenitors Derived from Human iPS Cells: A New Tool for Anti-obesity Drug Discovery and Cell-Based Therapy?

    Science.gov (United States)

    Yao, Xi; Salingova, Barbara; Dani, Christian

    2018-04-10

    Alternative strategies are urgently required to fight obesity and associated metabolic disorders including diabetes and cardiovascular diseases. Brown and brown-like adipocytes (BAs) store fat, but in contrast to white adipocytes, activated BAs are equipped to dissipate energy stored. Therefore, BAs represent promising cell targets to counteract obesity. However, the scarcity of BAs in adults is a major limitation for a BA-based therapy of obesity, and the notion to increase the BA mass by transplanting BA progenitors (BAPs) in obese patients recently emerged. The next challenge is to identify an abundant and reliable source of BAPs. In this chapter, we describe the capacity of human-induced pluripotent stem cells (hiPSCs) to generate BAPs able to differentiate at a high efficiency with no gene transfer. This cell model represents an unlimited source of human BAPs that in a near future may be a suitable tool for both therapeutic transplantation and for the discovery of novel efficient and safe anti-obesity drugs. The generation of a relevant cell model, such as hiPSC-BAs in 3D adipospheres enriched with macrophages and endothelial cells to better mimic the microenvironment within the adipose tissue, will be the next critical step.

  15. Brown adipocyte function

    DEFF Research Database (Denmark)

    Winther, Sally

    . The first part of this thesis explores this by identifying and investigating two novel kinase regulators of brown adipocyte function. Study 1 demonstrates that spleen tyrosine kinase is a hitherto undescribed regulator of brown adipocyte differentiation and activation. Study 2 identifies glycogen synthase...

  16. Macrophages and Adipocytes in Human Obesity Adipose Tissue Gene Expression and Insulin Sensitivity During Calorie Restriction and Weight Stabilization

    DEFF Research Database (Denmark)

    Capel, F.; Klimcakova, E.; Viguerie, N.

    2009-01-01

    OBJECTIVE-We investigated the regulation of adipose tissue gene expression during different phases of a dietary weight loss program and its relation with insulin sensitivity. RESEARCH DESIGN AND METHODS-Twenty-two obese women followed a dietary intervention program composed of an energy restriction...... expression profiling was performed using a DNA microarray in a subgroup of eight women. RT-quantitative PCR was used for determination of mRNA levels of 31 adipose tissue macrophage markers (n = 22). RESULTS-Body weight, fat mass, and C-reactive protein level decreased and glucose disposal rate increased...... during the dietary intervention program. Transcriptome profiling revealed two main patterns of variations. The first involved 464 mostly adipocyte genes involved in metabolism that were downregulated during energy restriction, upregulated during weight stabilization, and unchanged during the dietary...

  17. Adipocytes Impair Efficacy of Antiretroviral Therapy

    Science.gov (United States)

    Couturier, Jacob; Winchester, Lee C.; Suliburk, James W.; Wilkerson, Gregory K.; Podany, Anthony T.; Agarwal, Neeti; Chua, Corrine Ying Xuan; Nehete, Pramod N.; Nehete, Bharti P.; Grattoni, Alessandro; Sastry, K. Jagannadha; Fletcher, Courtney V.; Lake, Jordan E.; Balasubramanyan, Ashok; Lewis, Dorothy E.

    2018-01-01

    Adequate distribution of antiretroviral drugs to infected cells in HIV patients is critical for viral suppression. In humans and primates, HIV- and SIV-infected CD4 T cells in adipose tissues have recently been identified as reservoirs for infectious virus. To better characterize adipose tissue as a pharmacological sanctuary for HIV-infected cells, in vitro experiments were conducted to assess antiretroviral drug efficacy in the presence of adipocytes, and drug penetration in adipose tissue cells (stromal-vascular-fraction cells and mature adipocytes) was examined in treated humans and monkeys. Co-culture experiments between HIV-1-infected CD4 T cells and primary human adipocytes showed that adipocytes consistently reduced the antiviral efficacy of the nucleotide reverse transcriptase inhibitor tenofovir and its prodrug forms tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF). In HIV-infected persons, LC-MS/MS analysis of intracellular lysates derived from adipose tissue stromal-vascular-fraction cells or mature adipocytes suggested that integrase inhibitors penetrate adipose tissue, whereas penetration of nucleoside/nucleotide reverse transcriptase inhibitors such as TDF, emtricitabine, abacavir, and lamivudine is restricted. The limited distribution and functions of key antiretroviral drugs within fat depots may contribute to viral persistence in adipose tissue. PMID:29630975

  18. A strategy for solubilizing delipidated apolipoprotein with lysophosphatidylcholine and reconstitution with phosphatidylcholine

    International Nuclear Information System (INIS)

    Kawooya, J.K.; Wells, M.A.; Law, J.H.

    1989-01-01

    The apolipoproteins of insect lipophorin were dissociated in guanidinium chloride and isolated by gel permeation chromatography. Over 98% of the total lipid in lipophorin was associated with apolipophorin I (apoLp-I), thus suggesting this apolipoprotein to be the lipid binding component of the particle. ApoLp-I was delipidated with ethanol/ether and solubilized in buffer that contained radioactive lysophosphatidylcholine ([ 3 H]LPC) above the critical micellar concentration. Sonic irradiation of radioactive phosphatidylcholine ([ 14 C]PC) with [ 3 H]LPC-solubilized apoLp-I at a molar ratio of 318 resulted in reconstituted lipophorin I (RLp-I). [ 3 H]LPC was bound to fatty acid free bovine serum albumin and was separated from RLp-I by density gradient ultracentrifugation and gel permeation chromatography. Negatively stained RLp-I particles were quasispherical with an average radius of 55 angstrom, and their overall morphology and secondary structure were similar to those of native hemolymph lipophorin. The RLp-I particle had a ρ = 1.137 g/mL, a M r ∼ 5.2 x 10 5 , and a [ 14 C]PC:apoLp-I molar ratio of 308. From the compositional analysis, molecular size, trypsinization, and lipolysis with phospholipase A 2 , the authors concluded that each RLp-I particle contained one molecule of apoLp-I and a monomolecular layer of [ 14 C]PC. When injected into the hemolymph of adult moths in vivo, RLp-I was loaded with lipid, as judged by a decrease in its density both in the presence and in the absence of adipokinetic hormone. The similarities in morphology and immunology of RLp-I and native lipophorin, together with the ability of RLp-I to load lipid, suggest that reconstituted lipophorins may serve as models to probe lipophorin structure and function

  19. Fructose Alters Intermediary Metabolism of Glucose in Human Adipocytes and Diverts Glucose to Serine Oxidation in the One–Carbon Cycle Energy Producing Pathway

    Directory of Open Access Journals (Sweden)

    Vijayalakshmi Varma

    2015-06-01

    Full Text Available Increased consumption of sugar and fructose as sweeteners has resulted in the utilization of fructose as an alternative metabolic fuel that may compete with glucose and alter its metabolism. To explore this, human Simpson-Golabi-Behmel Syndrome (SGBS preadipocytes were differentiated to adipocytes in the presence of 0, 1, 2.5, 5 or 10 mM of fructose added to a medium containing 5 mM of glucose representing the normal blood glucose concentration. Targeted tracer [1,2-13C2]-d-glucose fate association approach was employed to examine the influence of fructose on the intermediary metabolism of glucose. Increasing concentrations of fructose robustly increased the oxidation of [1,2-13C2]-d-glucose to 13CO2 (p < 0.000001. However, glucose-derived 13CO2 negatively correlated with 13C labeled glutamate, 13C palmitate, and M+1 labeled lactate. These are strong markers of limited tricarboxylic acid (TCA cycle, fatty acid synthesis, pentose cycle fluxes, substrate turnover and NAD+/NADP+ or ATP production from glucose via complete oxidation, indicating diminished mitochondrial energy metabolism. Contrarily, a positive correlation was observed between glucose-derived 13CO2 formed and 13C oleate and doses of fructose which indicate the elongation and desaturation of palmitate to oleate for storage. Collectively, these results suggest that fructose preferentially drives glucose through serine oxidation glycine cleavage (SOGC pathway one-carbon cycle for NAD+/NADP+ production that is utilized in fructose-induced lipogenesis and storage in adipocytes.

  20. Adipocytes and abdominal aortic aneurysm: Putative potential role of adipocytes in the process of AAA development.

    Science.gov (United States)

    Kugo, Hirona; Moriyama, Tatsuya; Zaima, Nobuhiro

    2018-01-15

    Background Adipose tissue plays a role in the storage of excess energy as triglycerides (TGs). Excess fat accumulation causes various metabolic and cardiovascular diseases. It has been reported that ectopic fat deposition and excess TG accumulation in non-adipose tissue might be important predictors of cardiometabolic and vascular risk. For example, ectopic fat in perivascular tissue promotes atherosclerotic plaque formation in the arterial wall. Objective Recently, it has been reported that ectopic fat (adipocyte) in the vascular wall of an abdominal aortic aneurysm (AAA) is present in both human and experimental animal models. The pathological significance of adipocytes in the AAA wall has not been fully understood. In this review, we summarized the functions of adipocytes and discussed potential new drugs that target vascular adipocytes for AAA treatment. Result Previous studies suggest that adipocytes in vascular wall play an important role in the development of AAA. Conclusion Adipocytes in the vascular wall could be novel targets for the development of AAA therapeutic drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. The human lipodystrophy gene product Berardinelli-Seip congenital lipodystrophy 2/seipin plays a key role in adipocyte differentiation.

    Science.gov (United States)

    Chen, Weiqin; Yechoor, Vijay K; Chang, Benny Hung-Junn; Li, Ming V; March, Keith L; Chan, Lawrence

    2009-10-01

    Mutations in the Berardinelli-Seip congenital lipodystrophy 2 gene (BSCL2) are the underlying defect in patients with congenital generalized lipodystrophy type 2. BSCL2 encodes a protein called seipin, whose function is largely unknown. In this study, we investigated the role of Bscl2 in the regulation of adipocyte differentiation. Bscl2 mRNA is highly up-regulated during standard hormone-induced adipogenesis in 3T3-L1 cells in vitro. However, this up-regulation does not occur during mesenchymal stem cell (C3H10T1/2 cells) commitment to the preadipocyte lineage. Knockdown of Bscl2 by short hairpin RNA in C3H10T1/2 cells has no effect on bone morphogenetic protein-4-induced preadipocyte commitment. However, knockdown in 3T3-L1 cells prevents adipogenesis induced by a standard hormone cocktail, but adipogenesis can be rescued by the addition of peroxisome proliferator-activated receptor-gamma agonist pioglitazone at an early stage of differentiation. Interestingly, pioglitazone-induced differentiation in the absence of standard hormone is not associated with up-regulated Bscl2 expression. On the other hand, short hairpin RNA-knockdown of Bscl2 largely blocks pioglitazone-induced adipose differentiation. These experiments suggest that Bscl2 may be essential for normal adipogenesis; it works upstream or at the level of peroxisome proliferator-activated receptor-gamma, enabling the latter to exert its full activity during adipogenesis. Loss of Bscl2 function thus interferes with the normal transcriptional cascade of adipogenesis during fat cell differentiation, resulting in near total loss of fat or lipodystrophy.

  2. 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.

  3. IL-1β and TNFα inhibit GPR120 (FFAR4) and stimulate GPR84 (EX33) and GPR41 (FFAR3) fatty acid receptor expression in human adipocytes: implications for the anti-inflammatory action of n-3 fatty acids.

    Science.gov (United States)

    Muredda, Laura; Kępczyńska, Małgorzata A; Zaibi, Mohamed S; Alomar, Suliman Y; Trayhurn, Paul

    2018-05-01

    Regulation of the expression of GPCR fatty acid receptor genes has been examined in human adipocytes differentiated in culture. TNFα and IL-1β induced a marked reduction in GPR120 expression, mRNA level falling 17-fold at 24 h in adipocytes incubated with TNFα. In contrast, GPR84 mRNA was dramatically increased by these cytokines (>500-fold for IL-1β at 4 h); GPR41 expression was also stimulated. Rosiglitazone did not affect GPR84 expression, but GPR120 and GPR41 expression increased. Dexamethasone, insulin, linoleic and docosahexaenoic acids (DHA), and TUG891 (GPR120 agonist) had little effect on GPR120 and GPR84 expression. TUG891 did not attenuate the pro-inflammatory actions of TNFα and IL-1β. DHA slightly countered the actions of IL-1β on CCL2, IL6 and ADIPOQ expression, though not on secretion of these adipokines. GPR120 and GP84 gene expression in human adipocytes is highly sensitive to pro-inflammatory mediators; the inflammation-induced inhibition of GPR120 expression may compromise the anti-inflammatory action of GPR120 agonists.

  4. 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.

  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. 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...

  7. Decellularization and Delipidation Protocols of Bovine Bone and Pericardium for Bone Grafting and Guided Bone Regeneration Procedures.

    Directory of Open Access Journals (Sweden)

    Chiara Gardin

    Full Text Available The combination of bone grafting materials with guided bone regeneration (GBR membranes seems to provide promising results to restore bone defects in dental clinical practice. In the first part of this work, a novel protocol for decellularization and delipidation of bovine bone, based on multiple steps of thermal shock, washes with detergent and dehydration with alcohol, is described. This protocol is more effective in removal of cellular materials, and shows superior biocompatibility compared to other three methods tested in this study. Furthermore, histological and morphological analyses confirm the maintenance of an intact bone extracellular matrix (ECM. In vitro and in vivo experiments evidence osteoinductive and osteoconductive properties of the produced scaffold, respectively. In the second part of this study, two methods of bovine pericardium decellularization are compared. The osmotic shock-based protocol gives better results in terms of removal of cell components, biocompatibility, maintenance of native ECM structure, and host tissue reaction, in respect to the freeze/thaw method. Overall, the results of this study demonstrate the characterization of a novel protocol for the decellularization of bovine bone to be used as bone graft, and the acquisition of a method to produce a pericardium membrane suitable for GBR applications.

  8. Lipolytic effect of a polyphenolic citrus dry extract of red orange, grapefruit, orange (SINETROL) in human body fat adipocytes. Mechanism of action by inhibition of cAMP-phosphodiesterase (PDE).

    Science.gov (United States)

    Dallas, Constantin; Gerbi, Alain; Tenca, Guillaume; Juchaux, Franck; Bernard, François-Xavier

    2008-10-01

    The present study investigated the lipolytic (break of fat stored) effect of a citrus-based polyphenolic dietary supplement (SINETROL) at human adipocytes (ex vivo), body fat (clinical) and biochemical levels (inhibition of phosphodiesterase). Free fatty acids (FFA) release was used as indicator of human adipocyte lipolysis and SINETROL activity has been compared with known lipolytic products (isoproterenol, theopylline and caffeine). SINETROL stimulated significantly the lipolytic activity in a range of 6 fold greater than the control. Moreover, SINETROL has 2.1 greater activity than guarana 12% caffeine while its content in caffeine is 3 times lower. Clinically, two groups of 10 volunteers with BMI relevant of overweight were compared during 4 and 12 weeks with 1.4 g/day SINETROL and placebo supplementation. In the SINETROL Group the body fat (%) decreased with a significant difference of 5.53% and 15.6% after 4 and 12 weeks, respectively, while the body weight (kg) decreased with a significant difference of 2.2 and 5.2 kg after 4 and 12 weeks, respectively. These observed effects are linked to SINETROL polyphenolic composition and its resulting synergistic activity. SINETROL is a potent inhibitor of cAMP-phosphodiesterase (PDE) (97%) compared to other purified compounds (cyanidin-3 glycoside, narangin, caffeine). These results suggest that SINETROL has a strong lipolytic effect mediated by cAMP-PDE inhibition. SINETROL may serve to prevent obesity by decreasing BMI.

  9. Adipocyte triglyceride turnover and lipolysis in lean and overweight subjects.

    Science.gov (United States)

    Rydén, Mikael; Andersson, Daniel P; Bernard, Samuel; Spalding, Kirsty; Arner, Peter

    2013-10-01

    Human obesity is associated with decreased triglyceride turnover and impaired lipolysis in adipocytes. We determined whether such defects also occur in subjects with only moderate increase in fat mass. Human abdominal subcutaneous adipose tissue was investigated in healthy, nonobese subjects [body mass index (BMI) > 17 kg/m(2) and BMI lean subjects (P = 0.017) with triglyceride T1/2 of 14 and 9 months, respectively (P = 0.04). Triglyceride age correlated positively with BMI (P = 0.002) but not with adipocyte volume (P = 0.2). Noradrenaline-, isoprenaline- or dibutyryl cyclic AMP-induced lipolysis was inversely correlated with triglyceride age (P maintenance of excess body fat.

  10. The adipocyte as an important target cell for Trypanosoma cruzi infection.

    Science.gov (United States)

    Combs, Terry P; Nagajyothi; Mukherjee, Shankar; de Almeida, Cecilia J G; Jelicks, Linda A; Schubert, William; Lin, Ying; Jayabalan, David S; Zhao, Dazhi; Braunstein, Vicki L; Landskroner-Eiger, Shira; Cordero, Aisha; Factor, Stephen M; Weiss, Louis M; Lisanti, Michael P; Tanowitz, Herbert B; Scherer, Philipp E

    2005-06-24

    Adipose tissue plays an active role in normal metabolic homeostasis as well as in the development of human disease. Beyond its obvious role as a depot for triglycerides, adipose tissue controls energy expenditure through secretion of several factors. Little attention has been given to the role of adipocytes in the pathogenesis of Chagas disease and the associated metabolic alterations. Our previous studies have indicated that hyperglycemia significantly increases parasitemia and mortality in mice infected with Trypanosoma cruzi. We determined the consequences of adipocyte infection in vitro and in vivo. Cultured 3T3-L1 adipocytes can be infected with high efficiency. Electron micrographs of infected cells revealed a large number of intracellular parasites that cluster around lipid droplets. Furthermore, infected adipocytes exhibited changes in expression levels of a number of different adipocyte-specific or adipocyte-enriched proteins. The adipocyte is therefore an important target cell during acute Chagas disease. Infection of adipocytes by T. cruzi profoundly influences the pattern of adipokines. During chronic infection, adipocytes may represent an important long-term reservoir for parasites from which relapse of infection can occur. We have demonstrated that acute infection has a unique metabolic profile with a high degree of local inflammation in adipose tissue, hypoadiponectinemia, hypoglycemia, and hypoinsulinemia but with relatively normal glucose disposal during an oral glucose tolerance test.

  11. Adipocyte differentiation and leptin expression

    DEFF Research Database (Denmark)

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

    1997-01-01

    Adipose tissue has long been known to house the largest energy reserves in the animal body. Recent research indicates that in addition to this role, the adipocyte functions as a global regulator of energy metabolism. Adipose tissue is exquisitely sensitive to a variety of endocrine and paracrine ...... 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.......Adipose tissue has long been known to house the largest energy reserves in the animal body. Recent research indicates that in addition to this role, the adipocyte functions as a global regulator of energy metabolism. Adipose tissue is exquisitely sensitive to a variety of endocrine and paracrine......, 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...

  12. 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

    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...

  13. 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 ...

  14. [The adipocyte in the history of slimming agents].

    Science.gov (United States)

    Franchi, J; Pellicier, F; André, P; Schnebert, S

    2003-07-01

    Nowadays, in industrialised societies, it is fashionable for women to be slim. However, throughout history, this has not always been the case, especially as "cellulite" (cellulitis) was full of typically feminine symbols. The ideal feminine silhouette has changed with the rhythm of cultures. Cellulitis is an inappropriate term used by women to describe curves which they judge to be too plump and not very aesthetic, mostly around the thighs and hips. This lipodystrophy of the adipose tissue represents approximately 25% of a woman's body weight. It is clinically characterised by an "orange peel" skin surface, which is a result of the excessive development of the volume of the adipocytes organised in lobules within the walls of the unstretchable conjunctive tissue. This phenomenon is associated with an insufficiency of the venous tonus and an increase in the capillary permeability, which both contribute to an increase in the infiltration of water in the tissue. In reality, the understanding of cellulite has truly progressed with research based on adipocyte functions. An adipocyte is a metabolically active cell which plays a central role in the control of the energetic balance of the organism. In order to assume this role, it possesses all the enzymatic equipment necessary for synthesis (lipogenesis) and for triglyceride storage, mobilisation and liberation as free fatty acids (lipolysis). During these last few years, as well as this role as an energetic reserve which manages lipogenesis/lipolysis balance, the adipocyte has acquired the status of an endocrine and paracrine cell through the identification of numerous secreted factors. When we look back at the history of slimming products launched on the market since the 1980's, we can notice the role of the adipocyte tool and understand its functions in the choice of active ingredients, the development of complementary actions, the importance of the texture, the evolution of methods used to evaluate the efficacy on

  15. The action of D-dopachrome tautomerase as an adipokine in adipocyte lipid metabolism.

    Directory of Open Access Journals (Sweden)

    Takeo Iwata

    Full Text Available Adipose tissue is a critical exchange center for complex energy transactions involving triacylglycerol storage and release. It also has an active endocrine role, releasing various adipose-derived cytokines (adipokines that participate in complex pathways to maintain metabolic and vascular health. Here, we found D-dopachrome tautomerase (DDT as an adipokine secreted from human adipocytes by a proteomic approach. DDT mRNA levels in human adipocytes were negatively correlated with obesity-related clinical parameters such as BMI, and visceral and subcutaneous fat areas. Experiments using SGBS cells, a human preadipocyte cell line, revealed that DDT mRNA levels were increased in an adipocyte differentiation-dependent manner and DDT was secreted from adipocytes. In DDT knockdown adipocytes differentiated from SGBS cells that were infected with the adenovirus expressing shRNA against the DDT gene, mRNA levels of genes involved in both lipolysis and lipogenesis were slightly but significantly increased. Furthermore, we investigated AMP-activated protein kinase (AMPK signaling, which phosphorylates and inactivates enzymes involved in lipid metabolism, including hormone-sensitive lipase (HSL and acetyl-CoA carboxylase (ACC, in DDT knockdown adipocytes. The AMPK phosphorylation of HSL Ser-565 and ACC Ser-79 was inhibited in DDT knockdown cells and recovered in the cells treated with recombinant DDT (rDDT, suggesting that down-regulated DDT in adipocytes brings about a state of active lipid metabolism. Furthermore, administration of rDDT in db/db mice improved glucose intolerance and decreased serum free fatty acids levels. In the adipose tissue from rDDT-treated db/db mice, not only increased levels of HSL phosphorylated by AMPK, but also decreased levels of HSL phosphorylated by protein kinase A (PKA, which phosphorylates HSL to promote its activity, were observed. These results suggested that DDT acts on adipocytes to regulate lipid metabolism through

  16. miR-125b affects mitochondrial biogenesis and impairs brite adipocyte formation and function

    Directory of Open Access Journals (Sweden)

    Maude Giroud

    2016-08-01

    Full Text Available Objective: In rodents and humans, besides brown adipose tissue (BAT, islands of thermogenic adipocytes, termed “brite” (brown-in-white or beige adipocytes, emerge within white adipose tissue (WAT after cold exposure or β3-adrenoceptor stimulation, which may protect from obesity and associated diseases. microRNAs are novel modulators of adipose tissue development and function. The purpose of this work was to characterize the role of microRNAs in the control of brite adipocyte formation. Methods/Results: Using human multipotent adipose derived stem cells, we identified miR-125b-5p as downregulated upon brite adipocyte formation. In humans and rodents, miR-125b-5p expression was lower in BAT than in WAT. In vitro, overexpression and knockdown of miR-125b-5p decreased and increased mitochondrial biogenesis, respectively. In vivo, miR-125b-5p levels were downregulated in subcutaneous WAT and interscapular BAT upon β3-adrenergic receptor stimulation. Injections of an miR-125b-5p mimic and LNA inhibitor directly into WAT inhibited and increased β3-adrenoceptor-mediated induction of UCP1, respectively, and mitochondrial brite adipocyte marker expression and mitochondriogenesis. Conclusion: Collectively, our results demonstrate that miR-125b-5p plays an important role in the repression of brite adipocyte function by modulating oxygen consumption and mitochondrial gene expression. Author Video: Author Video Watch what authors say about their articles Keywords: miR-125b-5p, White adipocyte, Brite adipocyte, Mitochondriogenesis

  17. Regulation of glycolysis in brown adipocytes by HIF-1α

    DEFF Research Database (Denmark)

    Basse, Astrid L; Isidor, Marie S; Winther, Sally

    2017-01-01

    Brown adipose tissue takes up large amounts of glucose during cold exposure in mice and humans. Here we report an induction of glucose transporter 1 expression and increased expression of several glycolytic enzymes in brown adipose tissue from cold-exposed mice. Accordingly, these genes were also...... with glucose as the only exogenously added fuel. These data suggest that HIF-1α-dependent regulation of glycolysis is necessary for maximum glucose metabolism in brown adipocytes....

  18. Unravelling hair follicle-adipocyte communication.

    Science.gov (United States)

    Schmidt, Barbara; Horsley, Valerie

    2012-11-01

    Here, we explore the established and potential roles for intradermal adipose tissue in communication with hair follicle biology. The hair follicle delves deep into the rich dermal macroenvironment as it grows to maturity where it is surrounded by large lipid-filled adipocytes. Intradermal adipocytes regenerate with faster kinetics than other adipose tissue depots and in parallel with the hair cycle, suggesting an interplay exists between hair follicle cells and adipocytes. While adipocytes have well-established roles in metabolism and energy storage, until recently, they were overlooked as niche cells that provide important growth signals to neighbouring skin cells. We discuss recent data supporting adipocytes as niche cells for the skin and skin pathologies that may be related to alterations in skin adipose tissue defects. © 2012 John Wiley & Sons A/S.

  19. 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

  20. Adrenaline is a critical mediator of acute exercise-induced AMP-activated protein kinase activation in adipocytes

    Science.gov (United States)

    Koh, Ho-Jin; Hirshman, Michael F.; He, Huamei; Li, Yangfeng; Manabe, Yasuko; Balschi, James A.; Goodyear, Laurie J.

    2007-01-01

    Exercise increases AMPK (AMP-activated protein kinase) activity in human and rat adipocytes, but the underlying molecular mechanisms and functional consequences of this activation are not known. Since adrenaline (epinephrine) concentrations increase with exercise, in the present study we hypothesized that adrenaline activates AMPK in adipocytes. We show that a single bout of exercise increases AMPKα1 and α2 activities and ACC (acetyl-CoA carboxylase) Ser79 phosphorylation in rat adipocytes. Similarly to exercise, adrenaline treatment in vivo increased AMPK activities and ACC phosphorylation. Pre-treatment of rats with the β-blocker propranolol fully blocked exercise-induced AMPK activation. Increased AMPK activity with exercise and adrenaline treatment in vivo was accompanied by an increased AMP/ATP ratio. Adrenaline incubation of isolated adipocytes also increased the AMP/ATP ratio and AMPK activities, an effect blocked by propranolol. Adrenaline incubation increased lipolysis in isolated adipocytes, and Compound C, an AMPK inhibitor, attenuated this effect. Finally, a potential role for AMPK in the decreased adiposity associated with chronic exercise was suggested by marked increases in AMPKα1 and α2 activities in adipocytes from rats trained for 6 weeks. In conclusion, both acute and chronic exercise are significant regulators of AMPK activity in rat adipocytes. Our findings suggest that adrenaline plays a critical role in exercise-stimulated AMPKα1 and α2 activities in adipocytes, and that AMPK can function in the regulation of lipolysis. PMID:17253964

  1. 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......); intermediate (3T3-L1 pre-adipocytes); and low (cholesterol-depleted 3T3-L1 pre-adipocytes) caveolae levels. Using large-angle light scattering, we show that compared to pre-adipocytes, differentiated adipocytes exhibit several-fold increased rates of volume restoration following osmotic cell swelling (RVD......) 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...

  2. Exocytosis of macrophage lysosomes leads to digestion of apoptotic adipocytes and foam cell formation[S

    Science.gov (United States)

    Haka, Abigail S.; Barbosa-Lorenzi, Valéria C.; Lee, Hyuek Jong; Falcone, Domenick J.; Hudis, Clifford A.; Dannenberg, Andrew J.

    2016-01-01

    Many types of apoptotic cells are phagocytosed and digested by macrophages. Adipocytes can be hundreds of times larger than macrophages, so they are too large to be digested by conventional phagocytic processes. The nature of the interaction between macrophages and apoptotic adipocytes has not been studied in detail. We describe a cellular process, termed exophagy, that is important for macrophage clearance of dead adipocytes and adipose tissue homeostasis. Using mouse models of obesity, human tissue, and a cell culture model, we show that macrophages form hydrolytic extracellular compartments at points of contact with dead adipocytes using local actin polymerization. These compartments are acidic and contain lysosomal enzymes delivered by exocytosis. Uptake and complete degradation of adipocyte fragments, which are released by extracellular hydrolysis, leads to macrophage foam cell formation. Exophagy-mediated foam cell formation is a highly efficient means by which macrophages internalize large amounts of lipid, which may ultimately overwhelm the metabolic capacity of the macrophage. This process provides a mechanism for degradation of objects, such as dead adipocytes, that are too large to be phagocytosed by macrophages. PMID:27044658

  3. Plastic occlusion stress test as a model to investigate the effects of skin delipidization on the stratum corneum water holding capacity in vivo.

    Science.gov (United States)

    Berardesca, E; Herbst, R; Maibach, H

    1993-01-01

    The purpose of the study was to develop an in vivo model to study the effects of lipid removal on skin barrier. 16 subjects (age 41 +/- 8) were delipidized in vivo on the volar forearm using respectively ether/acetone (EA; 1:1) and chloroform/methanol (CM; 2:1). A third site served as control. Water holding capacity (WHC) was measured according to the plastic occlusion stress test (POST) procedure: the water desorption curve after removal of the occlusion was recorded in terms of skin surface water loss (SSWL) using an evaporimeter for 30 min. In the central part of the evaporation curve (bound water) the CM-treated site is significantly different from control and EA-treated sites (p rate of water from SC are higher in the CM-treated site (p evaporation of free water. We conclude that polar lipids have a key role in modulating barrier function and WHC of the stratum corneum. The POST can represent a useful in vivo model to study the effects of lipid extraction on skin function.

  4. 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.

  5. Trehalose prevents adipocyte hypertrophy and mitigates insulin resistance.

    Science.gov (United States)

    Arai, Chikako; Arai, Norie; Mizote, Akiko; Kohno, Keizo; Iwaki, Kanso; Hanaya, Toshiharu; Arai, Shigeyuki; Ushio, Simpei; Fukuda, Shigeharu

    2010-12-01

    Trehalose has been shown to evoke lower insulin secretion than glucose in oral saccharide tolerance tests in humans. Given this hypoinsulinemic effect of trehalose, we hypothesized that trehalose suppresses adipocyte hypertrophy by reducing storage of triglyceride and mitigates insulin resistance in mice fed a high-fat diet (HFD). Mice were fed an HFD and given drinking water containing 2.5% saccharide (glucose [Glc], trehalose [Tre], maltose [Mal], high-fructose corn syrup, or fructose [Fru]) ad libitum. After 7 weeks of HFD and saccharide intake, fasting serum insulin levels in the Tre/HFD group were significantly lower than in the Mal/HFD and Glc/HFD groups (P fructose corn syrup/HFD, or Fru/HFD group. Analysis of gene expression in mesenteric adipocytes showed that no statistically significant difference in the expression of monocyte chemoattractant protein-1 (MCP-1) messenger RNA (mRNA) was observed between the Tre/HFD group and the distilled water/standard diet group, whereas a significant increase in the MCP-1 mRNA expression was observed in the Glc/HFD, Mal/HFD, Fru/HFD, and distilled water/HFD groups. Thus, our data indicate that trehalose prevents adipocyte hypertrophy and mitigates insulin resistance in HFD-fed mice by reducing insulin secretion and down-regulating mRNA expression of MCP-1. These findings further suggest that trehalose is a functional saccharide that mitigates insulin resistance. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. HIV protease inhibitors disrupt lipid metabolism by activating endoplasmic reticulum stress and inhibiting autophagy activity in adipocytes.

    Directory of Open Access Journals (Sweden)

    Beth S Zha

    Full Text Available HIV protease inhibitors (PI are core components of Highly Active Antiretroviral Therapy (HAART, the most effective treatment for HIV infection currently available. However, HIV PIs have now been linked to lipodystrophy and dyslipidemia, which are major risk factors for cardiovascular disease and metabolic syndrome. Our previous studies have shown that HIV PIs activate endoplasmic reticulum (ER stress and disrupt lipid metabolism in hepatocytes and macrophages. Yet, little is known on how HIV PIs disrupt lipid metabolism in adipocytes, a major cell type involved in the pathogenesis of metabolic syndrome.Cultured and primary mouse adipocytes and human adipocytes were used to examine the effect of frequently used HIV PIs in the clinic, lopinavir/ritonavir, on adipocyte differentiation and further identify the underlying molecular mechanism of HIV PI-induced dysregulation of lipid metabolism in adipocytes. The results indicated that lopinavir alone or in combination with ritonavir, significantly activated the ER stress response, inhibited cell differentiation, and induced cell apoptosis in adipocytes. In addition, HIV PI-induced ER stress was closely linked to inhibition of autophagy activity. We also identified through the use of primary adipocytes of CHOP(-/- mice that CHOP, the major transcriptional factor of the ER stress signaling pathway, is involved in lopinavir/ritonavir-induced inhibition of cell differentiation in adipocytes. In addition, lopinavir/ritonavir-induced ER stress appears to be associated with inhibition of autophagy activity in adipocytes.Activation of ER stress and impairment of autophagy activity are involved in HIV PI-induced dysregulation of lipid metabolism in adipocytes. The key components of ER stress and autophagy signaling pathways are potential therapeutic targets for HIV PI-induced metabolic side effects in HIV patients.

  7. 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

  8. Direct Evidence of Brown Adipocytes in Different Fat Depots in Children

    Science.gov (United States)

    Rockstroh, Denise; Landgraf, Kathrin; Wagner, Isabel Viola; Gesing, Julia; Tauscher, Roy; Lakowa, Nicole; Kiess, Wieland; Bühligen, Ulf; Wojan, Magdalena; Till, Holger; Blüher, Matthias; Körner, Antje

    2015-01-01

    Recent studies suggested the persistence of brown adipocytes in adult humans, as opposed to being exclusively present in infancy. In this study, we investigated the presence of brown-like adipocytes in adipose tissue (AT) samples of children and adolescents aged 0 to 18 years and evaluated the association with age, location, and obesity. For this, we analysed AT samples from 131 children and 23 adults by histological, immunohistochemical and expression analyses. We detected brown-like and UCP1 positive adipocytes in 10.3% of 87 lean children (aged 0.3 to 10.7 years) and in one overweight infant, whereas we did not find brown adipocytes in obese children or adults. In our samples, the brown-like adipocytes were interspersed within white AT of perirenal, visceral and also subcutaneous depots. Samples with brown-like adipocytes showed an increased expression of UCP1 (>200fold), PRDM16 (2.8fold), PGC1α and CIDEA while other brown/beige selective markers, such as PAT2, P2RX5, ZIC1, LHX8, TMEM26, HOXC9 and TBX1 were not significantly different between UCP1 positive and negative samples. We identified a positive correlation between UCP1 and PRDM16 within UCP1 positive samples, but not with any other brown/beige marker. In addition, we observed significantly increased PRDM16 and PAT2 expression in subcutaneous and visceral AT samples with high UCP1 expression in adults. Our data indicate that brown-like adipocytes are present well beyond infancy in subcutaneous depots of non-obese children. The presence was not restricted to typical perirenal locations, but they were also interspersed within WAT of visceral and subcutaneous depots. PMID:25706927

  9. Impaired histone deacetylases 5 and 6 expression mimics the effects of obesity and hypoxia on adipocyte function

    Directory of Open Access Journals (Sweden)

    Julien Bricambert

    2016-12-01

    Full Text Available Objective: The goal of the study was to investigate the role of histone deacetylases (HDACs in adipocyte function associated with obesity and hypoxia. Methods: Total proteins and RNA were prepared from human visceral adipose tissues (VAT of human obese and normal weight subjects and from white adipose tissue (WAT of C57Bl6-Rj mice fed a normal or high fat diet (HFD for 16 weeks. HDAC activity was measured by colorimetric assay whereas the gene and protein expression were monitored by real-time PCR and by western blotting, respectively. RNA interference (RNAi was used to silence the expression of genes in 3T3-L1 adipocytes. Results: Total HDAC activity was decreased in VAT and WAT from obese individuals and from mice fed a HFD, respectively. The HDAC activity reduction was associated with decreased HDAC5/Hdac5 and HDAC6/Hdac6 expression in human and mice adipocyte fraction. Similarly, hypoxia hampered total Hdac activity and reduced the expression of Hdac5 and Hdac6 in 3T3-L1 adipocytes. The decrease of both Hdac5 and Hdac6 by hypoxia was associated with altered expression of adipokines and of the inducible cAMP early repressor (Icer, a key repressor that is defective in human and mice obesity. Silencing of Icer in adipocytes reproduced the changes in adipokine levels under hypoxia and obesity, suggesting a causative effect. Finally, modeling the defect of the two Hdacs in adipocytes by RNAi or selective inhibitors mimicked the effects of hypoxia on the expression of Icer, leading to impairment of insulin-induced glucose uptake. Conclusion: Hdac5 and Hdac6 expression are required for the adequate expression of Icer and adipocyte function. Altered adipose expression of the two Hdacs in obesity by hypoxia may contribute to the development of metabolic abnormalities. Keywords: Histone deacetylases, Adipocytes, Adipokines, Obesity, Insulin resistance

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

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    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.

  11. Naringenin Inhibits Adipogenesis and Reduces Insulin Sensitivity and Adiponectin Expression in Adipocytes

    Directory of Open Access Journals (Sweden)

    Allison J. Richard

    2013-01-01

    Full Text Available Adipose tissue development and function are widely studied to examine the relationship between obesity and the metabolic syndrome. It is well documented that the inability of adipose tissue to properly increase its lipid storage capacity during the obese state can lead to metabolic dysfunction. In a blind screen of 425 botanicals, we identified naringenin as an inhibitor of adipocyte differentiation. Naringenin is one of the most abundant citrus flavonoids, and recent studies have demonstrated antihyperlipidemic capabilities. These studies have largely focused on the effects of naringenin on the liver. Our biochemical studies clearly demonstrate that naringenin inhibits adipogenesis and impairs mature fat cell function. Naringenin specifically inhibited adipogenesis in a dose-dependent fashion as judged by examining lipid accumulation and induction of adipocyte marker protein expression. In mature 3T3-L1 adipocytes, naringenin reduced the ability of insulin to induce IRS-1 tyrosine phosphorylation and substantially inhibited insulin-stimulated glucose uptake in a dose-dependent manner and over a time frame of 1.5 to 24 hours. Exposure to naringenin also inhibited adiponectin protein expression in mature murine and human adipocytes. Our studies have revealed that naringenin may have a negative impact on adipocyte-related diseases by limiting differentiation of preadipocytes, by significantly inducing insulin resistance, and by decreasing adiponectin expression in mature fat cells.

  12. Lipid droplets hypertrophy: a crucial determining factor in insulin regulation by adipocytes

    Science.gov (United States)

    Sanjabi, Bahram; Dashty, Monireh; Özcan, Behiye; Akbarkhanzadeh, Vishtaseb; Rahimi, Mehran; Vinciguerra, Manlio; van Rooij, Felix; Al-Lahham, Saad; Sheedfar, Fareeba; van Kooten, Theo G.; Spek, C. Arnold; Rowshani, Ajda T.; van der Want, Johannes; Klaassen, Rene; Sijbrands, Eric; Peppelenbosch, Maikel P.; Rezaee, Farhad

    2015-03-01

    Lipid 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 constitutively synthesize and secrete insulin, which is biologically functional. Insulin concentrations and release are fat mass- and LDs-dependent respectively. Fat reduction mediated by bariatric surgery repairs obesity-associated T2D. The expression of genes, like PCSK1 (proinsulin conversion enzyme), GCG (Glucagon), GPLD1, CD38 and NNAT, involved in insulin regulation/release were differentially expressed in pancreas and adipose tissue (AT). INS (insulin) and GCG expression reduced in human AT-T2D as compared to AT-control, but remained unchanged in pancreas in either state. Insulin levels (mRNA/protein) were higher in AT derived from prediabetes BB rats with destructed pancreatic β-cells and controls than pancreas derived from the same rats respectively. Insulin expression in 10 human primary cell types including adipocytes and macrophages is an evidence for extrapancreatic insulin-producing cells. The data suggest a crosstalk between AT and pancreas to fine-tune energy metabolic system or may minimize the metabolic damage during diabetes. This study opens new avenues towards T2D therapy with a great impact on public health.

  13. SIK2 regulates CRTCs, HDAC4 and glucose uptake in adipocytes

    DEFF Research Database (Denmark)

    Henriksson, Emma; Säll, Johanna; Gormand, Amélie

    2015-01-01

    regulation in human adipocytes, strengthening the physiological relevance of our findings. Collectively, we demonstrate that SIK2 acts directly on CRTC2, CRTC3 and HDAC4, and that cAMP/PKA reduces the interaction of SIK2 with CRTCs and PP2A. Downstream, SIK2 promotes GLUT4 levels and glucose uptake...

  14. Adipocyte tissue volume in bone marrow is increased with aging and in patients with osteoporosis

    DEFF Research Database (Denmark)

    Justesen, J; Dokkedahl, Karin Stenderup; Ebbesen, E N

    2001-01-01

    Aging of the human skeleton is characterized by decreased bone formation and bone mass and these changes are more pronounced in patients with osteoporosis. As osteoblasts and adipocytes share a common precursor cell in the bone marrow, we hypothesized that decreased bone formation observed during...

  15. Obestatin regulates adipocyte function and protects against diet-induced insulin resistance and inflammation.

    Science.gov (United States)

    Granata, Riccarda; Gallo, Davide; Luque, Raul M; Baragli, Alessandra; Scarlatti, Francesca; Grande, Cristina; Gesmundo, Iacopo; Córdoba-Chacón, Jose; Bergandi, Loredana; Settanni, Fabio; Togliatto, Gabriele; Volante, Marco; Garetto, Stefano; Annunziata, Marta; Chanclón, Belén; Gargantini, Eleonora; Rocchietto, Stefano; Matera, Lina; Datta, Giacomo; Morino, Mario; Brizzi, Maria Felice; Ong, Huy; Camussi, Giovanni; Castaño, Justo P; Papotti, Mauro; Ghigo, Ezio

    2012-08-01

    The metabolic actions of the ghrelin gene-derived peptide obestatin are still unclear. We investigated obestatin effects in vitro, on adipocyte function, and in vivo, on insulin resistance and inflammation in mice fed a high-fat diet (HFD). Obestatin effects on apoptosis, differentiation, lipolysis, and glucose uptake were determined in vitro in mouse 3T3-L1 and in human subcutaneous (hSC) and omental (hOM) adipocytes. In vivo, the influence of obestatin on glucose metabolism was assessed in mice fed an HFD for 8 wk. 3T3-L1, hSC, and hOM preadipocytes and adipocytes secreted obestatin and showed specific binding for the hormone. Obestatin prevented apoptosis in 3T3-L1 preadipocytes by increasing phosphoinositide 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK)1/2 signaling. In both mice and human adipocytes, obestatin inhibited isoproterenol-induced lipolysis, promoted AMP-activated protein kinase phosphorylation, induced adiponectin, and reduced leptin secretion. Obestatin also enhanced glucose uptake in either the absence or presence of insulin, promoted GLUT4 translocation, and increased Akt phosphorylation and sirtuin 1 (SIRT1) protein expression. Inhibition of SIRT1 by small interfering RNA reduced obestatin-induced glucose uptake. In HFD-fed mice, obestatin reduced insulin resistance, increased insulin secretion from pancreatic islets, and reduced adipocyte apoptosis and inflammation in metabolic tissues. These results provide evidence of a novel role for obestatin in adipocyte function and glucose metabolism and suggest potential therapeutic perspectives in insulin resistance and metabolic dysfunctions.

  16. The Mechanism of White and Brown Adipocyte Differentiation

    Directory of Open Access Journals (Sweden)

    Hironori Nakagami

    2013-04-01

    Full Text Available Obesity gives vent to many diseases such as type 2 diabetes, hypertension, and hyperlipidemia, being considered as the main causes of mortality and morbidity worldwide. The pathogenesis and pathophysiology of metabolic syndrome can well be understood by studying the molecular mechanisms that control the development and function of adipose tissue. In human body, exist two types of adipose tissue, the white and the brown one, which are reported to play various roles in energy homeostasis. The major and most efficient storage of energy occurs in the form of triglycerides in white adipose tissue while brown adipose tissue actively participates in both basal and inducible energy consumption in the form of thermogenesis. Recent years have observed a rapid and greater interest towards developmental plasticity and therapeutic potential of stromal cells those isolated from adipose tissue. The adipocyte differentiation involves a couple of regulators in the white or brown adipogenesis. Peroxisome proliferators-activated receptor-γ actively participates in regulating carbohydrate and lipid metabolism, and also acts as main regulator of both white and brown adipogenesis. This review based on our recent research, seeks to highlight the adipocyte differentiation.

  17. 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.

    2012-01-01

    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. PMID:22822087

  18. 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.

  19. 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.

  20. Phosphatidylcholine induces apoptosis of 3T3-L1 adipocytes

    Directory of Open Access Journals (Sweden)

    Li Hailan

    2011-12-01

    Full Text Available Abstract Background Phosphatidylcholine (PPC formulation is used for lipolytic injection, even though its mechanism of action is not well understood. Methods The viability of 3T3-L1 pre-adipocytes and differentiated 3T3-L1 cells was measured after treatment of PPC alone, its vehicle sodium deoxycholate (SD, and a PPC formulation. Western blot analysis was performed to examine PPC-induced signaling pathways. Results PPC, SD, and PPC formulation significantly decreased 3T3-L1 cell viability in a concentration-dependent manner. PPC alone was not cytotoxic to CCD-25Sk human fibroblasts at concentrations Conclusions PPC results in apoptosis of 3T3-L1 cells.

  1. Rab18 dynamics in adipocytes in relation to lipogenesis, lipolysis and obesity.

    Directory of Open Access Journals (Sweden)

    Marina R Pulido

    Full Text Available Lipid droplets (LDs are organelles that coordinate lipid storage and mobilization, both processes being especially important in cells specialized in managing fat, the adipocytes. Proteomic analyses of LDs have consistently identified the small GTPase Rab18 as a component of the LD coat. However, the specific contribution of Rab18 to adipocyte function remains to be elucidated. Herein, we have analyzed Rab18 expression, intracellular localization and function in relation to the metabolic status of adipocytes. We show that Rab18 production increases during adipogenic differentiation of 3T3-L1 cells. In addition, our data show that insulin induces, via phosphatidylinositol 3-kinase (PI3K, the recruitment of Rab18 to the surface of LDs. Furthermore, Rab18 overexpression increased basal lipogenesis and Rab18 silencing impaired the lipogenic response to insulin, thereby suggesting that this GTPase promotes fat accumulation in adipocytes. On the other hand, studies of the β-adrenergic receptor agonist isoproterenol confirmed and extended previous evidence for the participation of Rab18 in lipolysis. Together, our data support the view that Rab18 is a common mediator of lipolysis and lipogenesis and suggests that the endoplasmic reticulum (ER is the link that enables Rab18 action on these two processes. Finally, we describe, for the first time, the presence of Rab18 in human adipose tissue, wherein the expression of this GTPase exhibits sex- and depot-specific differences and is correlated to obesity. Taken together, these findings indicate that Rab18 is involved in insulin-mediated lipogenesis, as well as in β-adrenergic-induced lipolysis, likely facilitating interaction of LDs with ER membranes and the exchange of lipids between these compartments. A role for Rab18 in the regulation of adipocyte biology under both normal and pathological conditions is proposed.

  2. 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

  3. Models of lipid droplets growth and fission in adipocyte cells

    Energy Technology Data Exchange (ETDEWEB)

    Boschi, Federico, E-mail: federico.boschi@univr.it [Department of Computer Science, University of Verona, Strada Le Grazie 15, 37134 Verona (Italy); Rizzatti, Vanni; Zamboni, Mauro [Department of Medicine, Geriatric Section, University of Verona, Piazzale Stefani 1, 37126 Verona (Italy); Sbarbati, Andrea [Department of Neurological and Movement Sciences, University of Verona, Strada Le Grazie 8, 37134 Verona (Italy)

    2015-08-15

    Lipid droplets (LD) are spherical cellular inclusion devoted to lipids storage. It is well known that excessive accumulation of lipids leads to several human worldwide diseases like obesity, type 2 diabetes, hepatic steatosis and atherosclerosis. LDs' size range from fraction to one hundred of micrometers in adipocytes and is related to the lipid content, but their growth is still a puzzling question. It has been suggested that LDs can grow in size due to the fusion process by which a larger LD is obtained by the merging of two smaller LDs, but these events seems to be rare and difficult to be observed. Many other processes are thought to be involved in the number and growth of LDs, like the de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets. Moreover the number and size of LDs are influenced by the catabolism and the absorption or interaction with other organelles. The comprehension of these processes could help in the confinement of the pathologies related to lipid accumulation. In this study the LDs' size distribution, number and the total volume of immature (n=12), mature (n=12, 10-days differentiated) and lipolytic (n=12) 3T3-L1 adipocytes were considered. More than 11,000 LDs were measured in the 36 cells after Oil Red O staining. In a previous work Monte Carlo simulations were used to mimic the fusion process alone between LDs. We found that, considering the fusion as the only process acting on the LDs, the size distribution in mature adipocytes can be obtained with numerical simulation starting from the size distribution in immature cells provided a very high rate of fusion events. In this paper Monte Carlo simulations were developed to mimic the interaction between LDs taking into account many other processes in addition to fusion (de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets) in order to reproduce the LDs growth and we also simulated the

  4. Models of lipid droplets growth and fission in adipocyte cells

    International Nuclear Information System (INIS)

    Boschi, Federico; Rizzatti, Vanni; Zamboni, Mauro; Sbarbati, Andrea

    2015-01-01

    Lipid droplets (LD) are spherical cellular inclusion devoted to lipids storage. It is well known that excessive accumulation of lipids leads to several human worldwide diseases like obesity, type 2 diabetes, hepatic steatosis and atherosclerosis. LDs' size range from fraction to one hundred of micrometers in adipocytes and is related to the lipid content, but their growth is still a puzzling question. It has been suggested that LDs can grow in size due to the fusion process by which a larger LD is obtained by the merging of two smaller LDs, but these events seems to be rare and difficult to be observed. Many other processes are thought to be involved in the number and growth of LDs, like the de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets. Moreover the number and size of LDs are influenced by the catabolism and the absorption or interaction with other organelles. The comprehension of these processes could help in the confinement of the pathologies related to lipid accumulation. In this study the LDs' size distribution, number and the total volume of immature (n=12), mature (n=12, 10-days differentiated) and lipolytic (n=12) 3T3-L1 adipocytes were considered. More than 11,000 LDs were measured in the 36 cells after Oil Red O staining. In a previous work Monte Carlo simulations were used to mimic the fusion process alone between LDs. We found that, considering the fusion as the only process acting on the LDs, the size distribution in mature adipocytes can be obtained with numerical simulation starting from the size distribution in immature cells provided a very high rate of fusion events. In this paper Monte Carlo simulations were developed to mimic the interaction between LDs taking into account many other processes in addition to fusion (de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets) in order to reproduce the LDs growth and we also simulated the

  5. Retroendocytosis of insulin in rat adipocytes

    International Nuclear Information System (INIS)

    Levy, J.R.; Olefsky, J.M.

    1986-01-01

    A variety of ligands internalized by receptor-mediated endocytosis follow a short circuit pathway that does not lead to degradation but results in rapid exocytosis of intact ligand, a process termed retroendocytosis. We studied the time course of [ 125 I]iodoinsulin processing and retroendocytosis after internalization in isolated rat adipocytes. After steady state binding and internalization, surface receptor-bound insulin was removed by exposing cells to a low pH at low temperatures. The cells containing internalized [ 125 I]iodoinsulin were reincubated in fresh medium; subsequently, the radioactivity remaining within the cells and released into the medium were analyzed at various times by trichloroacetic acid (TCA) precipitation, Sephadex G-50 gel filtration, and reverse phase HPLC. Cell-associated radioactivity progressively decreased after reincubation in 37 C buffer, with 50% released in 9 min and 85% by 45 min. In the media, TCA-precipitable material appeared quickly, with a t1/2 of 2 min, and plateaued by 10 min. TCA-soluble material was released continually throughout the 45-min period. The release of both TCA-precipitable and TCA-soluble material was temperature and energy dependent. Sephadex G-50 chromatography demonstrated the loss of insulin from the intracellular pool and its appearance in the medium with a time course similar to that of TCA-precipitable material. Reverse phase HPLC demonstrated that the intracellular and medium radioactivity eluting in peak II (insulin peak) on Sephadex G-50 was composed of both intact insulin and intermediates. After the internalization of insulin, rat adipocytes release not only small mol wt degradation products of insulin, but also insulin intermediates and intact insulin. The rate of retroendocytosis reported here is almost identical to the rate of insulin receptor recycling in rat adipocytes

  6. Saw palmetto ethanol extract inhibits adipocyte differentiation.

    Science.gov (United States)

    Villaverde, Nicole; Galvis, Adriana; Marcano, Adriana; Priestap, Horacio A; Bennett, Bradley C; Barbieri, M Alejandro

    2013-07-01

    The fruits of saw palmetto have been used for the treatment of a variety of urinary and reproductive system problems. In this study we investigated whether the fruit extracts affect in vitro adipogenesis. Saw palmetto ethanol extract inhibited the lipid droplet accumulation by induction media in a dose-dependent manner, and it also attenuated the protein expressions of C-EBPα and PPARγ. Phosphorylation of Erk1/2 and Akt1 were also decreased by saw palmetto ethanol extract. This report suggests that saw palmetto extracts selectively affect the adipocyte differentiation through the modulation of several key factors that play a critical role during adipogenesis.

  7. Tributyltin Differentially Promotes Development of a Phenotypically Distinct Adipocyte

    Science.gov (United States)

    Regnier, Shane M.; El-Hashani, Essam; Kamau, Wakanene; Zhang, Xiaojie; Massad, Nicole L.; Sargis, Robert M.

    2015-01-01

    Objective Environmental endocrine disrupting chemicals (EDCs) are increasingly implicated in the pathogenesis of obesity. Evidence implicates various EDCs as being pro-adipogenic, including tributyltin (TBT), which activates the peroxisome proliferator activated receptor-γ (PPARγ). However, the conditions required for TBT-induced adipogenesis and its functional consequences are incompletely known. Methods The co-stimulatory conditions necessary for preadipocyte-to-adipocyte differentiation were compared between TBT and the pharmacological PPARγ agonist troglitazone (Trog) in the 3T3-L1 cell line; basal and insulin-stimulated glucose uptake were assessed using radiolabeled 2-deoxyglucose. Results TBT enhanced expression of the adipocyte marker C/EBPα with co-exposure to either isobutylmethylxanthine or insulin in the absence of other adipogenic stimuli. Examination of several adipocyte-specific proteins revealed that TBT and Trog differentially affected protein expression despite comparable PPARγ stimulation. In particular, TBT reduced adiponectin expression upon maximal adipogenic stimulation. Under submaximal stimulation, TBT and Trog differentially promoted adipocyte-specific gene expression despite similar lipid accumulation. Moreover, TBT attenuated Trog-induced adipocyte gene expression under conditions of co-treatment. Finally, TBT-induced adipocytes exhibited altered glucose metabolism, with increased basal glucose uptake. Conclusions TBT-induced adipocytes are functionally distinct from those generated by a pharmacological PPARγ agonist, suggesting that obesogen-induced adipogenesis may generate dysfunctional adipocytes with the capacity to deleteriously affect global energy homeostasis. PMID:26243053

  8. Tributyltin differentially promotes development of a phenotypically distinct adipocyte.

    Science.gov (United States)

    Regnier, Shane M; El-Hashani, Essam; Kamau, Wakanene; Zhang, Xiaojie; Massad, Nicole L; Sargis, Robert M

    2015-09-01

    Environmental endocrine disrupting chemicals (EDCs) are increasingly implicated in the pathogenesis of obesity. Evidence implicates various EDCs as being proadipogenic, including tributyltin (TBT), which activates the peroxisome proliferator activated receptor-γ (PPARγ). However, the conditions required for TBT-induced adipogenesis and its functional consequences are incompletely known. The costimulatory conditions necessary for preadipocyte-to-adipocyte differentiation were compared between TBT and the pharmacological PPARγ agonist troglitazone (Trog) in the 3T3-L1 cell line; basal and insulin-stimulated glucose uptake were assessed using radiolabeled 2-deoxyglucose. TBT enhanced expression of the adipocyte marker C/EBPα with coexposure to either isobutylmethylxanthine or insulin in the absence of other adipogenic stimuli. Examination of several adipocyte-specific proteins revealed that TBT and Trog differentially affected protein expression despite comparable PPARγ stimulation. In particular, TBT reduced adiponectin expression upon maximal adipogenic stimulation. Under submaximal stimulation, TBT and Trog differentially promoted adipocyte-specific gene expression despite similar lipid accumulation. Moreover, TBT attenuated Trog-induced adipocyte gene expression under conditions of cotreatment. Finally, TBT-induced adipocytes exhibited altered glucose metabolism, with increased basal glucose uptake. TBT-induced adipocytes are functionally distinct from those generated by a pharmacological PPARγ agonist, suggesting that obesogen-induced adipogenesis may generate dysfunctional adipocytes with the capacity to deleteriously affect global energy homeostasis. © 2015 The Obesity Society.

  9. 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...

  10. Metabolic cooperativity between epithelial cells and adipocytes of mice

    International Nuclear Information System (INIS)

    Bartley, J.C.; Emerman, J.T.; Bissell, M.J.

    1981-01-01

    We have demonstrated that glycogen and lipid synthesis in adipocytes is modulated by the lactational state and that this modulation in mammary adipocytes requires the presence of the adjacent epithelial cells. Glycogen and lipid synthesis from [ 14 C]glucose was measured in mammary fat pads cleared of epithelium, in abdominal fat pads, and in adipocytes from both sources and from intact mammary gland of mature virgin, pregnant, and lactating mice. Accumulation of glycogen, the activity of glycogen synthase, and the lipogenic rate in abdominal and mammary adipocytes remained high during pregnancy but decreased to insignificant levels by early lactation. The depressant effects of lactation were observed solely in those mammary adipocytes isolated from intact glands. The presence of mammary epithelial cells was also required to effect the stimulated lipogenesis in mammary adipocytes during pregnancy. We conclude that the metabolic activity of adipocytes is modulated both during pregnancy and lactation to channel nutrients to the mammary epithelial cell. The fact that the changes occur in mammary adipocytes only when epithelial cells are present indicates that local as well as systemic factors are operating in these modulations

  11. Restricting glycolysis impairs brown adipocyte glucose and oxygen consumption

    DEFF Research Database (Denmark)

    Winther, Sally; Isidor, Marie Sophie; Basse, Astrid Linde

    2018-01-01

    During thermogenic activation, brown adipocytes take up large amounts of glucose. In addition, cold stimulation leads to an upregulation of glycolytic enzymes. Here we have investigated the importance of glycolysis for brown adipocyte glucose consumption and thermogenesis. Using siRNA-mediated kn......During thermogenic activation, brown adipocytes take up large amounts of glucose. In addition, cold stimulation leads to an upregulation of glycolytic enzymes. Here we have investigated the importance of glycolysis for brown adipocyte glucose consumption and thermogenesis. Using si...... of glycolysis, i.e., hexokinase 2 (HK2) and pyruvate kinase M (PKM), respectively, decreased glucose uptake and ISO-stimulated oxygen consumption. HK2 knockdown had a more severe effect, which, in contrast to PKM knockdown, could not be rescued by supplementation with pyruvate. Hence, brown adipocytes rely...... on glucose consumption and glycolytic flux to achieve maximum thermogenic output, with glycolysis likely supporting thermogenesis not only by pyruvate formation but also by supplying intermediates for efferent metabolic pathways....

  12. 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.

  13. Adipocyte aminopeptidases in obesity and fasting.

    Science.gov (United States)

    Alponti, Rafaela Fadoni; Silveira, Paulo Flavio

    2015-11-05

    This study checked the existence of a diverse array of aminopeptidase (AP) enzymes in high (HDM) and low (LDM) density microsomal and plasma membrane (MF) fractions from adipocytes of control, monosodium glutamate obese and food deprived rats. Gene expression was detected for ArgAP, AspAP, MetAP, and two AlaAP (APM and PSA). APM and PSA had the highest catalytic efficiency, whereas AspAP the highest affinity. Subcellular distribution of AP activities depended on metabolic status. Comparing catalytic levels, AspAP in HDM, LDM and MF was absent in obese and control under food deprivation; PSA in LDM was 3.5-times higher in obese than in normally fed control and control and obese under food deprivation; MetAP in MF was 4.5-times higher in obese than in food deprived obese. Data show new AP enzymes genetically expressed in subcellular compartments of adipocytes, three of them with altered catalytic levels that respond to whole-body energetic demands. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. CUDC-907 Promotes Bone Marrow Adipocytic Differentiation Through Inhibition of Histone Deacetylase and Regulation of Cell Cycle.

    Science.gov (United States)

    Ali, Dalia; Alshammari, Hassan; Vishnubalaji, Radhakrishnan; Chalisserry, Elna Paul; Hamam, Rimi; Alfayez, Musaad; Kassem, Moustapha; Aldahmash, Abdullah; Alajez, Nehad M

    2017-03-01

    The role of bone marrow adipocytes (BMAs) in overall energy metabolism and their effects on bone mass are currently areas of intensive investigation. BMAs differentiate from bone marrow stromal cells (BMSCs); however, the molecular mechanisms regulating BMA differentiation are not fully understood. In this study, we investigated the effect of CUDC-907, identified by screening an epigenetic small-molecule library, on adipocytic differentiation of human BMSCs (hBMSCs) and determined its molecular mechanism of action. Human bone marrow stromal cells exposed to CUDC-907 (500 nM) exhibited enhanced adipocytic differentiation (∼2.9-fold increase, P < 0.005) compared with that of control cells. Global gene expression and signaling pathway analyses of differentially expressed genes revealed a strong enrichment of genes involved in adipogenesis, cell cycle, and DNA replication. Chromatin immune precipitation combined with quantitative polymerase chain reaction showed significant increase in H3K9ac epigenetic marker in the promoter regions of AdipoQ, FABP4, PPARγ, KLF15, and CEBPA in CUDC-907-treated hBMSCs. Follow-up experiments corroborated that the inhibition of histone deacetylase (HDAC) activity enhanced adipocytic differentiation, while the inhibition of PI3K decreased adipocytic differentiation. In addition, CUDC-907 arrested hBMSCs in the G0-G1 phase of the cell cycle and reduced the number of S-phase cells. Our data reveal that HDAC, PI3K, and cell cycle genes are important regulators of BMA formation and demonstrate that adipocyte differentiation of hBMSCs is associated with complex changes in a number of epigenetic and genetic pathways, which can be targeted to regulate BMA formation.

  15. 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://dbarchi...ve.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.50.AllAg.White_adipocytes.bed ...

  16. 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://dbarchi...ve.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.05.AllAg.White_adipocytes.bed ...

  17. 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://dbarchi...ve.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.10.AllAg.White_adipocytes.bed ...

  18. 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://dbarchi...ve.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.20.AllAg.White_adipocytes.bed ...

  19. 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.

  20. Obestatin as a regulator of adipocyte metabolism and adipogenesis

    Science.gov (United States)

    Gurriarán-Rodríguez, Uxía; Al-Massadi, Omar; Roca-Rivada, Arturo; Crujeiras, Ana Belén; Gallego, Rosalía; Pardo, Maria; Seoane, Luisa Maria; Pazos, Yolanda; Casanueva, Felipe F; Camiña, Jesús P

    2011-01-01

    Abstract The role of obestatin, a 23-amino-acid peptide encoded by the ghrelin gene, on the control of the metabolism of pre-adipocyte and adipocytes as well as on adipogenesis was determined. For in vitro assays, pre-adipocyte and adipocyte 3T3-L1 cells were used to assess the obestatin effect on cell metabolism and adipogenesis based on the regulation of the key enzymatic nodes, Akt and AMPK and their downstream targets. For in vivo assays, white adipose tissue (WAT) was obtained from male rats under continuous subcutaneous infusion of obestatin. Obestatin activated Akt and its downstream targets, GSK3α/β, mTOR and S6K1, in 3T3-L1 adipocyte cells. Simultaneously, obestatin inactivated AMPK in this cell model. In keeping with this, ACC phosphorylation was also decreased. This fact was confirmed in vivo in white adipose tissue (omental, subcutaneous and gonadal) obtained from male rats under continuous sc infusion of obestatin (24 and 72 hrs). The relevance of obestatin as regulator of adipocyte metabolism was supported by AS160 phosphorylation, GLUT4 translocation and augment of glucose uptake in 3T3-L1 adipocyte cells. In contrast, obestatin failed to modify translocation of fatty acid transporters, FATP1, FATP4 and FAT/CD36, to plasma membrane. Obestatin treatment in combination with IBMX and DEX showed to regulate the expression of C/EBPα, C/EBPβ, C/EBPδ and PPARγ promoting adipogenesis. Remarkable, preproghrelin expression, and thus obestatin expression, increased during adipogenesis being sustained throughout terminal differentiation. Neutralization of endogenous obestatin secreted by 3T3-L1 cells by anti-obestatin antibody decreased adipocyte differentiation. Furthermore, knockdown experiments by preproghrelin siRNA supported that obestatin contributes to adipogenesis. In summary, obestatin promotes adipogenesis in an autocrine/paracrine manner, being a regulator of adipocyte metabolism. These data point to a putative role in the pathogenesis of

  1. 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.

  2. Adipocyte-Macrophage Cross-Talk in Obesity.

    Science.gov (United States)

    Engin, Ayse Basak

    2017-01-01

    Obesity is characterized by the chronic low-grade activation of the innate immune system. In this respect, macrophage-elicited metabolic inflammation and adipocyte-macrophage interaction has a primary importance in obesity. Large amounts of macrophages are accumulated by different mechanisms in obese adipose tissue. Hypertrophic adipocyte-derived chemotactic monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2) pathway also promotes more macrophage accumulation into the obese adipose tissue. However, increased local extracellular lipid concentrations is a final mechanism for adipose tissue macrophage accumulation. A paracrine loop involving free fatty acids and tumor necrosis factor-alpha (TNF-alpha) between adipocytes and macrophages establishes a vicious cycle that aggravates inflammatory changes in the adipose tissue. Adipocyte-specific caspase-1 and production of interleukin-1beta (IL-1beta) by macrophages; both adipocyte and macrophage induction by toll like receptor-4 (TLR4) through nuclear factor-kappaB (NF-kappaB) activation; free fatty acid-induced and TLR-mediated activation of c-Jun N-terminal kinase (JNK)-related pro-inflammatory pathways in CD11c+ immune cells; are effective in macrophage accumulation and in the development of adipose tissue inflammation. Old adipocytes are removed by macrophages through trogocytosis or sending an "eat me" signal. The obesity-induced changes in adipose tissue macrophage numbers are mainly due to increases in the triple-positive CD11b+ F4/80+ CD11c+ adipose tissue macrophage subpopulation. The ratio of M1-to-M2 macrophages is increased in obesity. Furthermore, hypoxia along with higher concentrations of free fatty acids exacerbates macrophage-mediated inflammation in obesity. The metabolic status of adipocytes is a major determinant of macrophage inflammatory output. Macrophage/adipocyte fatty-acid-binding proteins act at the interface of metabolic and inflammatory pathways. Both macrophages and

  3. Inhibition of adipogenesis and leptin production in 3T3-L1 adipocytes by a derivative of meridianin C

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yu-Kyoung [Department of Molecular Medicine, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Lee, Tae-Yoon [Department of Microbiology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-gu, Daegu 705-717 (Korea, Republic of); Choi, Jong-Soon [Division of Life Science, Korea Basic Science Institute, 169-148 Gwahakro, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Hong, Victor Sukbong [Department of Chemistry, College of Natural Sciences, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Lee, Jinho, E-mail: jinho@gw.kmu.ac.kr [Department of Chemistry, College of Natural Sciences, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Park, Jong-Wook, E-mail: j303nih@dsmc.or.kr [Department of Immunology, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Jang, Byeong-Churl, E-mail: jangbc123@gw.kmu.ac.kr [Department of Molecular Medicine, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of)

    2014-10-03

    Highlights: • Compound 7b, a meridianin C derivative, inhibits adipogenesis. • Compound 7b inhibits C/EBP-α, PPAR-γ, FAS, STAT-3, and STAT-5 in 3T3-L1 adipocytes. • Compound 7b inhibits leptin, but not adiponectin, expression in 3T3-L1 adipocytes. • Compound 7b thus may have therapeutic potential against obesity. - Abstract: Meridianin C, a marine alkaloid, is a potent protein kinase inhibitor and has anti-cancer activity. We have recently developed a series of meridianin C derivatives (compound 7a–7j) and reported their proviral integration Moloney Murine Leukemia Virus (pim) kinases’ inhibitory and anti-proliferative effects on human leukemia cells. Here we investigated the effect of these meridianin C derivatives on adipogenesis. Strikingly, among the derivatives tested, compound 7b most strongly inhibited lipid accumulation during the differentiation of 3T3-L1 preadipocytes into adipocytes. However, meridianin C treatment was largely cytotoxic to 3T3-L1 adipocytes. On mechanistic levels, compound 7b reduced not only the expressions of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), and fatty acid synthase (FAS) but also the phosphorylation levels of signal transducer and activator of transcription-3 (STAT-3) and STAT-5 during adipocyte differentiation. Moreover, compound 7b repressed leptin, but not adiponectin, expression during adipocyte differentiation. Collectively, these findings demonstrate that a meridianin C derivative inhibits adipogenesis by down-regulating expressions and/or phosphorylations of C/EBP-α, PPAR-γ, FAS, STAT-3 and STAT-5.

  4. Adipocyte lipid synthesis coupled to neuronal control of thermogenic programming

    Directory of Open Access Journals (Sweden)

    Adilson Guilherme

    2017-08-01

    Conclusions: These results demonstrate that downregulation of fatty acid synthesis via FASN depletion in white adipocytes of mature mice can stimulate neuronal signaling to control thermogenic programming in iWAT.

  5. Effects of Methylmercury exposure in 3T3-L1 Adipocytes

    Directory of Open Access Journals (Sweden)

    Theresa Vertigan

    2017-02-01

    Full Text Available Mercury-containing compounds are environmental pollutants that have become increasingly consequential in the Arctic regions of North America due to processes of climate change increasing their release and availability at northern latitudes. Currently, the form of mercury known to be most detrimental to human health is methylmercury, CH3Hg+, which is found in the environment and accumulates in the tissues of piscivores, including those consumed by Alaska Natives through subsistence gathering. Much is known about the neurotoxicity of methylmercury after exposure to high concentrations, but little is known about toxicity to other tissues and cell types, particularly for long-term exposure and the lower concentrations that would occur through fish consumption. Effects of methylmercury exposure on 3T3-L1 adipocytes in culture were assessed using assays for cytotoxicity and an ELISA assay for vascular endothelial growth factor (VEGF, a signaling molecule shown to be important for maintaining metabolic status in adipose tissue. Results showed that exposure to methylmercury leads to significant toxicity in adipocytes at exposures of 100 ng/mL during later stages of differentiation, but lower methylmercury concentrations produced little to no toxicity. Results also showed that VEGF secretion is elevated in adipocytes exposed to methylmercury after the process of differentiating into mature, fat-storing cells. These results provide a basis for further exploration into metabolic consequences of methylmercury exposure on specific cell types and cell models.

  6. HO-1 Upregulation Attenuates Adipocyte Dysfunction, Obesity, and Isoprostane Levels in Mice Fed High Fructose Diets

    Directory of Open Access Journals (Sweden)

    Zeid Khitan

    2014-01-01

    Full Text Available Background. Fructose metabolism is an unregulated metabolic pathway and excessive fructose consumption is known to activate ROS. HO-1 is a potent antioxidant gene that plays a key role in decreasing ROS and isoprostanes. We examined whether the fructose-mediated increase in adipocyte dysfunction involves an increase in isoprostanes and that pharmacological induction of HO-1 would decrease both isoprostane levels and adipogenesis. Methods and Results. We examined the effect of fructose, on adipogenesis in human MSCs in the presence and absence of CoPP, an inducer of HO-1. Fructose increased adipogenesis and the number of large lipid droplets while decreasing the number of small lipid droplets (P<0.05. Levels of heme and isoprostane in fructose treated MSC-derived adipocytes were increased. CoPP reversed these effects and markedly increased HO-1 and the Wnt signaling pathway. The high fructose diet increased heme levels in adipose tissue and increased circulating isoprostane levels (P<0.05 versus control. Fructose diets decreased HO-1 and adiponectin levels in adipose tissue. Induction of HO-1 by CoPP decreased isoprostane synthesis (P<0.05 versus fructose. Conclusion. Fructose treatment resulted in increased isoprostane production and adipocyte dysfunction, which was reversed by the increased expression of HO-1.

  7. MiR-637 maintains the balance between adipocytes and osteoblasts by directly targeting Osterix.

    Science.gov (United States)

    Zhang, Jin-fang; Fu, Wei-ming; He, Ming-liang; Wang, Hua; Wang, Wei-mao; Yu, Shi-cang; Bian, Xiu-Wu; Zhou, Jin; Lin, Marie C M; Lu, Gang; Poon, Wai-sang; Kung, Hsiang-fu

    2011-11-01

    Bone development is dynamically regulated by homeostasis, in which a balance between adipocytes and osteoblasts is maintained. Disruption of this differentiation balance leads to various bone-related metabolic diseases, including osteoporosis. In the present study, a primate-specific microRNA (miR-637) was found to be involved in the differentiation of human mesenchymal stem cells (hMSCs). Our preliminary data indicated that miR-637 suppressed the growth of hMSCs and induced S-phase arrest. Expression of miR-637 was increased during adipocyte differentiation (AD), whereas it was decreased during osteoblast differentiation (OS), which suggests miR-637 could act as a mediator of adipoosteogenic differentiation. Osterix (Osx), a significant transcription factor of osteoblasts, was shown to be a direct target of miR-637, which significantly enhanced AD and suppressed OS in hMSCs through direct suppression of Osx expression. Furthermore, miR-637 also significantly enhanced de novo adipogenesis in nude mice. In conclusion, our data indicated that the expression of miR-637 was indispensable for maintaining the balance of adipocytes and osteoblasts. Disruption of miR-637 expression patterns leads to irreversible damage to the balance of differentiation in bone marrow.

  8. Role of extrathyroidal TSHR expression in adipocyte differentiation and its association with obesity

    Directory of Open Access Journals (Sweden)

    Lu Sumei

    2012-01-01

    Full Text Available Abstract Background Obesity is known to be associated with higher risks of cardiovascular disease, metabolic syndrome, and diabetes mellitus. Thyroid-stimulating hormone (TSHR is the receptor for thyroid-stimulating hormone (TSH, or thyrotropin, the key regulator of thyroid functions. The expression of TSHR, once considered to be limited to thyrocytes, has been so far detected in many extrathyroidal tissues including liver and fat. Previous studies have shown that TSHR expression is upregulated when preadipocytes differentiate into mature adipocytes, suggestive of a possible role of TSHR in adipogenesis. However, it remains unclear whether TSHR expression in adipocytes is implicated in the pathogenesis of obesity. Methods In the present study, TSHR expression in adipose tissues from both mice and human was analyzed, and its association with obesity was evaluated. Results We here showed that TSHR expression was increased at both mRNA and protein levels when 3T3-L1 preadipocytes were induced to differentiate. Knockdown of TSHR blocked the adipocyte differentiation of 3T3-L1 preadipocytes as evaluated by Oil-red-O staining for lipid accumulation and by RT-PCR analyses of PPAR-γ and ALBP mRNA expression. We generated obesity mice (C57/BL6 by high-fat diet feeding and found that the TSHR protein expression in visceral adipose tissues from obesity mice was significantly higher in comparison with the non-obesity control mice (P Conclusion Taken together, these results suggested that TSHR is an important regulator of adipocyte differentiation. Dysregulated expression of TSHR in adipose tissues is associated with obesity, which may involve a mechanism of excess adipogenesis.

  9. Macrophage-secreted factors induce adipocyte inflammation and insulin resistance

    International Nuclear Information System (INIS)

    Permana, Paska A.; Menge, Christopher; Reaven, Peter D.

    2006-01-01

    Macrophage infiltration into adipose tissue increases with obesity, a condition associated with low-grade inflammation and insulin resistance. We investigated the direct effects of macrophage-secreted factors on adipocyte inflammation and insulin resistance. 3T3-L1 adipocytes incubated with media conditioned by RAW264.7 macrophages (RAW-CM) showed dramatically increased transcription of several inflammation-related genes, greater nuclear factor kappa B (NF-κB) activity, and enhanced binding of U937 monocytes. All of these effects were prevented by co-incubation with pyrrolidinedithiocarbamate, an NF-κB inhibitor. Adipocytes incubated with RAW-CM also released more non-esterified fatty acids and this increased lipolysis was not suppressed by insulin. In addition, RAW-CM treatment decreased insulin-stimulated glucose uptake in adipocytes. Taken together, these results indicate that macrophage-secreted factors induce inflammatory responses and reduce insulin responsiveness in adipocytes. These effects of macrophage-secreted factors on adipocytes may contribute significantly to the systemic inflammation and insulin resistance associated with obesity

  10. Regional differences in adipocyte lactate production from glucose

    International Nuclear Information System (INIS)

    Newby, F.D.; Sykes, M.N.; DiGirolamo, M.

    1988-01-01

    Having shown that lactate is an important product of glucose metabolism by rat epididymal adipocytes, the authors investigated possible regional differences in adipocyte lactate production and the role of the animals' nutritional state and stage of development. [U- 14 C]glucose metabolism, lactate production, and response to insulin were measured in fat cells isolated from four adipose regions from young lean and older fatter rats, killed either in the fed state or after fasting for 48 h. In the absence of insulin, mesenteric fat cells from either age group metabolized significantly more glucose per cell and converted more glucose to lactate than cells from other depots, regardless of nutritional state. Adipocytes from fasted lean rats showed a significant increase in the relative glucose conversion to lactate in all depots when compared with cells from fed lean rats. Fasting of older fatter rats, however, had limited effects on the relative adipocyte glucose conversion to lactate since lactate production was already high. Mesenteric fat cells had the lowest relative response to insulin, possibly due to the high basal rate of glucose metabolism. These findings indicate that differences exist among adipose regions in the rates of glucose metabolism, lactate production and response to insulin. The anatomical location of the mesenteric adipose depot, coupled with a high metabolic rate and blood perfusion, suggests that mesenteric adipocytes may provide a unique and more direct contribution of metabolic substrates for hepatic metabolism than adipocytes from other depots

  11. Bone marrow adipocytes as negative regulators of the hematopoietic microenvironment

    Science.gov (United States)

    Naveiras, Olaia; Nardi, Valentina; Wenzel, Pamela L.; Fahey, Frederic; Daley, George Q.

    2009-01-01

    Osteoblasts and endothelium constitute functional niches that support hematopoietic stem cells (HSC) in mammalian bone marrow (BM) 1,2,3 . Adult BM also contains adipocytes, whose numbers correlate inversely with the hematopoietic activity of the marrow. Fatty infiltration of hematopoietic red marrow follows irradiation or chemotherapy and is a diagnostic feature in biopsies from patients with marrow aplasia 4. To explore whether adipocytes influence hematopoiesis or simply fill marrow space, we compared the hematopoietic activity of distinct regions of the mouse skeleton that differ in adiposity. By flow cytometry, colony forming activity, and competitive repopulation assay, HSCs and short-term progenitors are reduced in frequency in the adipocyte-rich vertebrae of the mouse tail relative to the adipocyte-free vertebrae of the thorax. In lipoatrophic A-ZIP/F1 “fatless” mice, which are genetically incapable of forming adipocytes8, and in mice treated with the PPARγ inhibitor Bisphenol-A-DiGlycidyl-Ether (BADGE), which inhibits adipogenesis9, post-irradiation marrow engraftment is accelerated relative to wild type or untreated mice. These data implicate adipocytes as predominantly negative regulators of the bone marrow microenvironment, and suggest that antagonizingmarrow adipogenesis may enhance hematopoietic recovery in clinical bone marrow transplantation. PMID:19516257

  12. 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 ...

  13. L-rhamnose induces browning in 3T3-L1 white adipocytes and activates HIB1B brown adipocytes.

    Science.gov (United States)

    Choi, Minji; Mukherjee, Sulagna; Kang, Nam Hyeon; Barkat, Jameel Lone; Parray, Hilal Ahmad; Yun, Jong Won

    2018-04-11

    Induction of the brown adipocyte-like phenotype in white adipocytes (browning) is considered as a novel strategy to fight obesity due to the ability of brown adipocytes to increase energy expenditure. Here, we report that L-rhamnose induced browning by elevating expression levels of beige-specific marker genes, including Cd137, Cited1, Tbx1, Prdm16, Tmem26, and Ucp1, in 3T3-L1 adipocytes. Moreover, L-rhamnose markedly elevated expression levels of proteins involved in thermogenesis both in 3T3-L1 white and HIB1B brown adipocytes. L-rhamnose treatment in 3T3-L1 adipocytes also significantly elevated protein levels of p-HSL, p-AMPK, ACOX, and CPT1 as well as reduced levels of ACC, FAS, C/EBPα, and PPARγ, suggesting its possible role in enhancement of lipolysis and lipid catabolism as well as reduced adipogenesis and lipogenesis, respectively. The quick technique of efficient molecular docking provided insight into the strong binding of L-rhamnose to the fat-digesting glycine residue of β 3 -adrenergic receptor (AR), indicating strong involvement of L-rhamnose in fat metabolism. Further examination of the molecular mechanism of L-rhamnose revealed that it induced browning of 3T3-L1 adipocytes via coordination of multiple signaling pathways through β 3 -AR, SIRT1, PKA, and p-38. To the best of our knowledge, this is the first study to demonstrate that L-rhamnose plays multiple modulatory roles in the induction of white fat browning, activation of brown adipocytes, as well as promotion of lipid metabolism, thereby demonstrating its therapeutic potential for treatment of obesity. © 2018 IUBMB Life, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

  14. Nuclear organization during in vitro differentiation of porcine mesenchymal stem cells (MSCs) into adipocytes.

    Science.gov (United States)

    Stachecka, Joanna; Walczak, Agnieszka; Kociucka, Beata; Ruszczycki, Błażej; Wilczyński, Grzegorz; Szczerbal, Izabela

    2018-02-01

    Differentiation of progenitor cells into adipocytes is accompanied by remarkable changes in cell morphology, cytoskeletal organization, and gene expression profile. Mature adipocytes are filled with a large lipid droplet and the nucleus tends to move to the cell periphery. It was hypothesized that the differentiation process is also associated with changes of nuclear organization. The aim of this study was to determine the number and distribution of selected components of nuclear architecture during porcine in vitro adipogenesis. The pig is an important animal model sharing many similarities to humans at the anatomical, physiological, and genetic levels and has been recognized as a good model for human obesity. Thus, understanding how cellular structures important for fundamental nuclear processes may be altered during adipocyte differentiation is of great importance. Mesenchymal stem cells (MSCs) were derived from bone marrow (BM-MSCs) and adipose tissue (AD-MSCs) and were cultured for 7 days in the adipogenic medium. A variable differentiation potential of these cell populations towards adipogenic lineage was observed, and for further study, a comparative characteristic of the nuclear organization in BM-MSCs and AD-MSCs was performed. Nuclear substructures were visualized by indirect immunofluorescence (nucleoli, nuclear speckles, PML bodies, lamins, and HP1α) or fluorescence in situ hybridization (telomeres) on fixed cells at 0, 3, 5, and 7 days of differentiation. Comprehensive characterization of these structures, in terms of their number, size, dynamics, and arrangement in three-dimensional space of the nucleus, was performed. It was found that during differentiation of porcine MSCs into adipocytes, changes of nuclear organization occurred and concerned: (1) the nuclear size and shape; (2) reduced lamin A/C expression; and (3) reorganization of chromocenters. Other elements of nuclear architecture such as nucleoli, SC-35 nuclear speckles, and telomeres

  15. Small non coding RNAs in adipocyte biology and obesity.

    Science.gov (United States)

    Amri, Ez-Zoubir; Scheideler, Marcel

    2017-11-15

    Obesity has reached epidemic proportions world-wide and constitutes a substantial risk factor for hypertension, type 2 diabetes, cardiovascular diseases and certain cancers. So far, regulation of energy intake by dietary and pharmacological treatments has met limited success. The main interest of current research is focused on understanding the role of different pathways involved in adipose tissue function and modulation of its mass. Whole-genome sequencing studies revealed that the majority of the human genome is transcribed, with thousands of non-protein-coding RNAs (ncRNA), which comprise small and long ncRNAs. ncRNAs regulate gene expression at the transcriptional and post-transcriptional level. Numerous studies described the involvement of ncRNAs in the pathogenesis of many diseases including obesity and associated metabolic disorders. ncRNAs represent potential diagnostic biomarkers and promising therapeutic targets. In this review, we focused on small ncRNAs involved in the formation and function of adipocytes and obesity. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. 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.

  17. Cloning, characterization and expression of Peking duck fatty acid synthase during adipocyte differentiation

    Directory of Open Access Journals (Sweden)

    Fang Ding

    2014-11-01

    Conclusion: We have successfully cloned and characterized Peking duck FAS. FAS was induced during adipocyte differentiation and by oleic acid treatment. These findings suggest that Peking duck FAS plays a similar role to mammalian FAS during adipocyte differentiation.

  18. Subcutaneous white adipocytes express a light sensitive signaling pathway mediated via a melanopsin/TRPC channel axis.

    Science.gov (United States)

    Ondrusova, Katarina; Fatehi, Mohammad; Barr, Amy; Czarnecka, Zofia; Long, Wentong; Suzuki, Kunimasa; Campbell, Scott; Philippaert, Koenraad; Hubert, Matthew; Tredget, Edward; Kwan, Peter; Touret, Nicolas; Wabitsch, Martin; Lee, Kevin Y; Light, Peter E

    2017-11-27

    Subcutaneous white adipose tissue (scWAT) is the major fat depot in humans and is a central player in regulating whole body metabolism. Skin exposure to UV wavelengths from sunlight is required for Vitamin D synthesis and pigmentation, although it is plausible that longer visible wavelengths that penetrate the skin may regulate scWAT function. In this regard, we discovered a novel blue light-sensitive current in human scWAT that is mediated by melanopsin coupled to transient receptor potential canonical cation channels. This pathway is activated at physiological intensities of light that penetrate the skin on a sunny day. Daily exposure of differentiated adipocytes to blue light resulted in decreased lipid droplet size, increased basal lipolytic rate and alterations in adiponectin and leptin secretion. Our results suggest that scWAT function may be directly under the influence of ambient sunlight exposure and may have important implications for our current understanding of adipocyte biology. (150 words).

  19. Actin depolymerization enhances adipogenic differentiation in human stromal stem cells

    DEFF Research Database (Denmark)

    Chen, Li; Hu, Huimin; Qiu, Weimin

    2018-01-01

    Human stromal stem cells (hMSCs) differentiate into adipocytes that play a role in skeletal tissue homeostasis and whole body energy metabolism. During adipocyte differentiation, hMSCs exhibit significant changes in cell morphology suggesting changes in cytoskeletal organization. Here, we examined...... differentiation as evidenced by decreased number of mature adipocytes and decreased adipocyte specific gene expression (ADIPOQ, LPL, PPARG, FABP4). In contrast, disruption of actin cytoskeleton by Cytochalasin D enhanced adipocyte differentiation. Follow up studies revealed that the effects of CFL1 on adipocyte...... differentiation depended on the activity of LIM domain kinase 1 (LIMK1) which is the major upstream kinase of CFL1. Inhibiting LIMK by its specific chemical inhibitor LIMKi inhibited the phosphorylation of CFL1 and actin polymerization, and enhanced the adipocyte differentiation. Moreover, treating h...

  20. The transport of DDT from chylomicrons to adipocytes does not mimic triacylglycerol transport

    Science.gov (United States)

    Kohan, Alison B.; Vandersall, Abbey E.; Yang, Qing; Xu, Min; Jandacek, Ronald J.; Tso, Patrick

    2012-01-01

    Despite being banned in the U.S., organochlorine toxins such as DDT are frequently detected in human adipose tissue. The main route of exposure is through the consumption of contaminated foods and subsequent intestinal packaging of DDT into chylomicrons. These chylomicrons, which also contain dietary triacylglycerol (TG), are delivered directly to peripheral tissues without first being metabolized by the liver. The physiological process by which these compounds are delivered from chylomicrons to adipose is not well understood, but is clinically relevant since it bypasses first-pass metabolism. Based on its highly lipophilic nature, it has been assumed that DDT is transferred to peripheral tissues similar to TG; however, this has not been measured. Here, we use the lymph fistula rat to isolate chylomicrons containing both DDT and TG. These chylomicrons are the in vivo DDT delivery vehicle. Using 3T3-L1 adipocytes, we investigated the rate at which DDT transfers from chylomicrons to adipocytes, and mediators of this process. This novel approach closely approximates the in vivo DDT exposure route. We show that: 1) DDT repartitions from chylomicrons to adipocytes, 2) this transport does not require hydrolysis of TG within the chylomicron, and is stimulated by the inhibition of LPL, 3) albumin does not inhibit DDT uptake, 4) DDT dissolved in DMSO does not appropriately mimic in vivo DDT transport; and most importantly, 5) DDT uptake from chylomicrons does not mimic the uptake of TG from the same particles. Understanding these factors is important for designing interventions for human populations exposed to DDT. PMID:22885168

  1. Optical visualisation of thermogenesis in stimulated single-cell brown adipocytes.

    Science.gov (United States)

    Kriszt, Rókus; Arai, Satoshi; Itoh, Hideki; Lee, Michelle H; Goralczyk, Anna G; Ang, Xiu Min; Cypess, Aaron M; White, Andrew P; Shamsi, Farnaz; Xue, Ruidan; Lee, Jung Yeol; Lee, Sung-Chan; Hou, Yanyan; Kitaguchi, Tetsuya; Sudhaharan, Thankiah; Ishiwata, Shin'ichi; Lane, E Birgitte; Chang, Young-Tae; Tseng, Yu-Hua; Suzuki, Madoka; Raghunath, Michael

    2017-05-03

    The identification of brown adipose deposits in adults has led to significant interest in targeting this metabolically active tissue for treatment of obesity and diabetes. Improved methods for the direct measurement of heat production as the signature function of brown adipocytes (BAs), particularly at the single cell level, would be of substantial benefit to these ongoing efforts. Here, we report the first application of a small molecule-type thermosensitive fluorescent dye, ERthermAC, to monitor thermogenesis in BAs derived from murine brown fat precursors and in human brown fat cells differentiated from human neck brown preadipocytes. ERthermAC accumulated in the endoplasmic reticulum of BAs and displayed a marked change in fluorescence intensity in response to adrenergic stimulation of cells, which corresponded to temperature change. ERthermAC fluorescence intensity profiles were congruent with mitochondrial depolarisation events visualised by the JC-1 probe. Moreover, the averaged fluorescence intensity changes across a population of cells correlated well with dynamic changes such as thermal power, oxygen consumption, and extracellular acidification rates. These findings suggest ERthermAC as a promising new tool for studying thermogenic function in brown adipocytes of both murine and human origins.

  2. Carotenoids and their conversion products in the control of adipocyte function, adiposity and obesity.

    Science.gov (United States)

    Luisa Bonet, M; Canas, Jose A; Ribot, Joan; Palou, Andreu

    2015-04-15

    A novel perspective of the function of carotenoids and carotenoid-derived products - including, but not restricted to, the retinoids - is emerging in recent years which connects these compounds to the control of adipocyte biology and body fat accumulation, with implications for the management of obesity, diabetes and cardiovascular disease. Cell and animal studies indicate that carotenoids and carotenoids derivatives can reduce adiposity and impact key aspects of adipose tissue biology including adipocyte differentiation, hypertrophy, capacity for fatty acid oxidation and thermogenesis (including browning of white adipose tissue) and secretory function. Epidemiological studies in humans associate higher dietary intakes and serum levels of carotenoids with decreased adiposity. Specifically designed human intervention studies, though still sparse, indicate a beneficial effect of carotenoid supplementation in the accrual of abdominal adiposity. The objective of this review is to summarize recent findings in this area, place them in physiological contexts, and provide likely regulatory schemes whenever possible. The focus will be on the effects of carotenoids as nutritional regulators of adipose tissue biology and both animal and human studies, which support a role of carotenoids and retinoids in the prevention of abdominal adiposity. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Palmitate Antagonizes Wnt/Beta-catenin Signaling in 3T3-L1 Pre-adipocytes

    Science.gov (United States)

    Long chain saturated free fatty acids such as palmitate (PA) produce insulin resistance, endoplasmic reticulum stress, and apoptosis in mature adipocytes and pre-adipocytes. In pre-adipocytes, saturated free fatty acids also promote adipogenic induction in the presence of adipogenic hormones. Wnt/be...

  4. Actin depolymerization enhances adipogenic differentiation in human stromal stem cells.

    Science.gov (United States)

    Chen, Li; Hu, Huimin; Qiu, Weimin; Shi, Kaikai; Kassem, Moustapha

    2018-05-01

    Human stromal stem cells (hMSCs) differentiate into adipocytes that play a role in skeletal tissue homeostasis and whole body energy metabolism. During adipocyte differentiation, hMSCs exhibit significant changes in cell morphology suggesting changes in cytoskeletal organization. Here, we examined the effect of direct modulation of actin microfilament dynamics on adipocyte differentiation. Stabilizing actin filaments in hMSCs by siRNA-mediated knock down of the two main actin depolymerizing factors (ADFs): Cofilin 1 (CFL1) and Destrin (DSTN) or treating the cells by Phalloidin reduced adipocyte differentiation as evidenced by decreased number of mature adipocytes and decreased adipocyte specific gene expression (ADIPOQ, LPL, PPARG, FABP4). In contrast, disruption of actin cytoskeleton by Cytochalasin D enhanced adipocyte differentiation. Follow up studies revealed that the effects of CFL1 on adipocyte differentiation depended on the activity of LIM domain kinase 1 (LIMK1) which is the major upstream kinase of CFL1. Inhibiting LIMK by its specific chemical inhibitor LIMKi inhibited the phosphorylation of CFL1 and actin polymerization, and enhanced the adipocyte differentiation. Moreover, treating hMSCs by Cytochalasin D inhibited ERK and Smad2 signaling and this was associated with enhanced adipocyte differentiation. On the other hand, Phalloidin enhanced ERK and Smad2 signaling, but inhibited adipocyte differentiation which was rescued by ERK specific chemical inhibitor U0126. Our data provide a link between restructuring of hMSCs cytoskeleton and hMSCs lineage commitment and differentiation. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Deficiency in adipocyte chemokine receptor CXCR4 exacerbates obesity and compromises thermoregulatory responses of brown adipose tissue in a mouse model of diet-induced obesity

    Science.gov (United States)

    Yao, Longbiao; Heuser-Baker, Janet; Herlea-Pana, Oana; Zhang, Nan; Szweda, Luke I.; Griffin, Timothy M.; Barlic-Dicen, Jana

    2014-01-01

    The chemokine receptor CXCR4 is expressed on adipocytes and macrophages in adipose tissue, but its role in this tissue remains unknown. We evaluated whether deficiency in either adipocyte or myeloid leukocyte CXCR4 affects body weight (BW) and adiposity in a mouse model of high-fat-diet (HFD)-induced obesity. We found that ablation of adipocyte, but not myeloid leukocyte, CXCR4 exacerbated obesity. The HFD-fed adipocyte-specific CXCR4-knockout (AdCXCR4ko) mice, compared to wild-type C57BL/6 control mice, had increased BW (average: 52.0 g vs. 35.5 g), adiposity (average: 49.3 vs. 21.0% of total BW), and inflammatory leukocyte content in white adipose tissue (WAT), despite comparable food intake. As previously reported, HFD feeding increased uncoupling protein 1 (UCP1) expression (fold increase: 3.5) in brown adipose tissue (BAT) of the C57BL/6 control mice. However, no HFD-induced increase in UCP1 expression was observed in the AdCXCR4ko mice, which were cold sensitive. Thus, our study suggests that adipocyte CXCR4 limits development of obesity by preventing excessive inflammatory cell recruitment into WAT and by supporting thermogenic activity of BAT. Since CXCR4 is conserved between mouse and human, the newfound role of CXCR4 in mouse adipose tissue may parallel the role of this chemokine receptor in human adipose tissue.—Yao, L., Heuser-Baker, J., Herlea-Pana, O., Zhang, N., Szweda, L. I., Griffin, T. M., Barlic-Dicen, J. Deficiency in adipocyte chemokine receptor CXCR4 exacerbates obesity and compromises thermoregulatory responses of brown adipose tissue in a mouse model of diet-induced obesity. PMID:25016030

  6. 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

  7. Modulation of adipocyte lipogenesis by octanoate: involvement of reactive oxygen species

    Directory of Open Access Journals (Sweden)

    Han Jianrong

    2006-07-01

    Full Text Available Abstract Background Octanoate is a medium-chain fatty acid (MCFA that is rich in milk and tropical dietary lipids. It also accounts for 70% of the fatty acids in commercial medium chain triglycerides (MCT. Use of MCT for weight control tracks back to early 1950s and is highlighted by recent clinical trials. The molecular mechanisms of the weight reduction effect remain not completely understood. The findings of significant amounts of MCFA in adipose tissue in MCT-fed animals and humans suggest a direct influence of MCFA on fat cell functions. Methods 3T3-L1 adipocytes were treated with octanoate in a high glucose culture medium supplemented with 10% fetal bovine serum and 170 nM insulin. The effects on lipogenesis, fatty acid oxidation, cellular concentration of reactive oxygen species (ROS, and the expression and activity of peroxisome proliferator receptor gamma (PPARγ and its associated lipogenic genes were assessed. In selected experiments, long-chain fatty acid oleate, PPARγ agonist troglitazone, and antioxidant N-acetylcysteine were used in parallel. Effects of insulin, L-carnitine, and etomoxir on β-oxidation were also measured. Results β-oxidation of octanoate was primarily independent of CPT-I. Treatment with octanoate was linked to an increase in ROS in adipocytes, a decrease in triglyceride synthesis, and reduction of lipogenic gene expression. Co-treatment with troglitazone, N-acetylcysteine, or over-expression of glutathione peroxidase largely reversed the effects of octanoate. Conclusion These findings suggest that octanoate-mediated inactivation of PPARγ might contribute to the down regulation of lipogenic genes in adipocytes, and ROS appears to be involved as a mediator in this process.

  8. Lipid droplet meets a mitochondrial protein to regulate adipocyte lipolysis

    Science.gov (United States)

    In response to adrenergic stimulation, adipocytes undergo protein kinase A (PKA)-stimulated lipolysis. A key PKA target in this context is perilipin 1, a major regulator of lipolysis on lipid droplets (LDs). A study published in this issue of The EMBO Journal (Pidoux et al, 2011) identifies optic at...

  9. Regulation of adipocyte differentiation and function by polyunsaturated fatty acids

    DEFF Research Database (Denmark)

    Madsen, Lise; Petersen, Rasmus Koefoed; Kristiansen, Karsten

    2005-01-01

    factors currently implicated as key players in adipocyte differentiation and function, including peroxisome proliferator activated receptors (PPARs) (alpha, beta and gamma), sterol regulatory element binding proteins (SREBPs) and liver X receptors (LXRs). We review evidence that dietary n-3 PUFAs decrease...

  10. Extracellular Vesicles from Hypoxic Adipocytes and Obese Subjects Reduce Insulin‐Stimulated Glucose Uptake

    Science.gov (United States)

    Mleczko, Justyna; Ortega, Francisco J.; Falcon‐Perez, Juan Manuel; Wabitsch, Martin; Fernandez‐Real, Jose Manuel

    2018-01-01

    Scope We investigate the effects of extracellular vesicles (EVs) obtained from in vitro adipocyte cell models and from obese subjects on glucose transport and insulin responsiveness. Methods and results EVs are isolated from the culture supernatant of adipocytes cultured under normoxia, hypoxia (1% oxygen), or exposed to macrophage conditioned media (15% v/v). EVs are isolated from the plasma of lean individuals and subjects with obesity. Cultured adipocytes are incubated with EVs and activation of insulin signalling cascades and insulin‐stimulated glucose transport are measured. EVs released from hypoxic adipocytes impair insulin‐stimulated 2‐deoxyglucose uptake and reduce insulin mediated phosphorylation of AKT. Insulin‐mediated phosphorylation of extracellular regulated kinases (ERK1/2) is not affected. EVs from individuals with obesity decrease insulin stimulated 2‐deoxyglucose uptake in adipocytes (p = 0.0159). Conclusion EVs released by stressed adipocytes impair insulin action in neighboring adipocytes. PMID:29292863

  11. Phenyllactic Acid from Lactobacillus plantarum PromotesAdipogenic Activity in 3T3-L1 Adipocyte via Up-Regulationof PPAR-γ2

    Directory of Open Access Journals (Sweden)

    Soundharrajan Ilavenil

    2015-08-01

    Full Text Available Synthetic drugs are commonly used to cure various human ailments at present. However, the uses of synthetic drugs are strictly regulated because of their adverse effects. Thus, naturally occurring molecules may be more suitable for curing disease without unfavorable effects. Therefore, we investigated phenyllactic acid (PLA from Lactobacillus plantarum with respect to its effects on adipogenic genes and their protein expression in 3T3-L1 pre-adipocytes by qPCR and western blot techniques. PLA enhanced differentiation and lipid accumulation in 3T3-L1 cells at the concentrations of 25, 50, and 100 μM. Maximum differentiation and lipid accumulation were observed at a concentration of 100 μM of PLA, as compared with control adipocytes (p < 0.05. The mRNA and protein expression of PPAR-γ2, C/EBP‑α, adiponectin, fatty acid synthase (FAS, and SREBP-1 were increased by PLA treatment as compared with control adipocytes (p < 0.05. PLA stimulates PPAR-γ mRNA expression in a concentration dependent manner, but this expression was lesser than agonist (2.83 ± 0.014 fold of PPAR-γ2. Moreover, PLA supplementation enhances glucose uptake in 3T3-L1 pre-adipocytes (11.81 ± 0.17 mM compared to control adipocytes, but this glucose uptake was lesser than that induced by troglitazone (13.75 ± 0.95 mM and insulin treatment (15.49 ± 0.20 mM. Hence, we conclude that PLA treatment enhances adipocyte differentiation and glucose uptake via activation of PPAR-γ2, and PLA may thus be the potential candidate for preventing Type 2 Diabetes Mellitus (T2DM.

  12. Effect of TNF-Alpha on Caveolin-1 Expression and Insulin Signaling During Adipocyte Differentiation and in Mature Adipocytes

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    Sara Palacios-Ortega

    2015-07-01

    Full Text Available Background/Aims: Tumor necrosis factor-α (TNF-α-mediated chronic low-grade inflammation of adipose tissue is associated with obesity and insulin resistance. Caveolin-1 (Cav-1 is the central component of adipocyte caveolae and has an essential role in the regulation of insulin signaling. The effects of TNF-α on Cav-1 expression and insulin signaling during adipocyte differentiation and in mature adipocytes were studied. Methods: 3T3-L1 cells were differentiated (21 days in the presence TNF-α (10 ng/mL and mature adipocytes were also treated with TNF-α for 48 hours. Cav-1 and insulin receptor (IR gene methylation were determined as well as Cav-1, IR, PKB/AKT-2 and Glut-4 expression and activation by real time RT-PCR and western blot. Baseline and insulin-induced glucose uptake was measured by the 2-[C14]-deoxyglucose uptake assay. Results: TNF-α slowed down the differentiation program, hindering the expression of some insulin signaling intermediates without fully eliminating insulin-mediated glucose uptake. In mature adipocytes, TNF-α did not compromise lipid-storage capacity, but downregulated the expression of the insulin signaling intermediates, totally blocking insulin-mediated glucose uptake. Insulin sensitivity correlated with the level of activated phospho-Cav-1 in both situations, strongly suggesting the direct contribution of Cav-1 to the maintenance of this physiological response. Conclusion: Cav-1 activation by phosphorylation seems to be essential for the maintenance of an active and insulin-sensitive glucose uptake.

  13. Quercetin Impacts Expression of Metabolism- and Obesity-Associated Genes in SGBS Adipocytes

    Directory of Open Access Journals (Sweden)

    Andreas Leiherer

    2016-05-01

    Full Text Available Obesity is characterized by the rapid expansion of visceral adipose tissue, resulting in a hypoxic environment in adipose tissue which leads to a profound change of gene expression in adipocytes. As a consequence, there is a dysregulation of metabolism and adipokine secretion in adipose tissue leading to the development of systemic inflammation and finally resulting in the onset of metabolic diseases. The flavonoid quercetin as well as other secondary plant metabolites also referred to as phytochemicals have anti-oxidant, anti-inflammatory, and anti-diabetic effects known to be protective in view of obesity-related-diseases. Nevertheless, its underlying molecular mechanism is still obscure and thus the focus of this study was to explore the influence of quercetin on human SGBS (Simpson Golabi Behmel Syndrome adipocytes’ gene expression. We revealed for the first time that quercetin significantly changed expression of adipokine (Angptl4, adipsin, irisin and PAI-1 and glycolysis-involved (ENO2, PFKP and PFKFB4 genes, and that this effect not only antagonized but in part even overcompensated the effect mediated by hypoxia in adipocytes. Thus, these results are explained by the recently proposed hypothesis that the protective effect of quercetin is not solely due to its free radical-scavenging activity but also to a direct effect on mitochondrial processes, and they demonstrate that quercetin might have the potential to counteract the development of obesity-associated complications.

  14. Role of epidermis-type lipoxygenases for skin barrier function and adipocyte differentiation

    DEFF Research Database (Denmark)

    Fürstenberger, Gerhard; Epp, Nikolas; Eckl, Katja-Martina

    2007-01-01

    12R-lipoxygenase (12R-LOX) and epidermis-type LOX-3 (eLOX-3) are novel members of the multigene family of mammalian LOX. A considerable gap exists between the identification of these enzymes and their biologic function. Here, we present evidence that 12R-LOX and eLOX-3, acting in sequence, and eL...... evidence indicates that this ligand is an eLOX-3-derived product. In accordance with this data is the observation that forced expression of eLOX-3 enhances adipocyte differentiation.......LOX-3 in combination with another, not yet identified LOX are critically involved in terminal differentiation of keratinocytes and adipocytes, respectively. Mutational inactivation of 12R-LOX and/or eLOX-3 has been found to be associated with development of an inherited ichthyosiform skin disorder...... in humans and genetic ablation of 12R-LOX causes a severe impairment of the epidermal lipid barrier in mice leading to post-natal death of the animals. In preadipocytes, a LOX-dependent PPARgamma activating ligand is released into the cell supernatant early upon induction of differentiation and available...

  15. Stevioside from Stevia rebaudiana Bertoni Increases Insulin Sensitivity in 3T3-L1 Adipocytes

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    Nabilatul Hani Mohd-Radzman

    2013-01-01

    Full Text Available Stevioside from Stevia rebaudiana has been reported to exert antihyperglycemic effects in both rat and human subjects. There have been few studies on these effects in vitro. In this paper, radioactive glucose uptake assay was implemented in order to assess improvements in insulin sensitivity in 3T3-L1 cells by elevation of glucose uptake following treatment with stevioside. Oil Red-O staining and MTT assay were utilized to confirm adipocyte differentiation and cell viability, respectively. Findings from this research showed a significant increase in absorbance values in mature adipocytes following Oil Red-O staining, confirming the differentiation process. Stevioside was noncytotoxic to 3T3-L1 cells as cell viability was reduced by a maximum of 17%, making it impossible to determine its IC50. Stevioside increased glucose uptake activities by 2.1 times (p<0.001 in normal conditions and up to 4.4 times (p<0.001 in insulin-resistant states. At times, this increase was higher than that seen in positive control group treated with rosiglitazone maleate, an antidiabetic agent. Expressions of pY20 and p-IRS1 which were measured via Western blot were improved by stevioside treatment. In conclusion, stevioside has direct effects on 3T3-L1 insulin sensitivity via increase in glucose uptake and enhanced expression of proteins involved in insulin-signalling pathway.

  16. Administration of Bioflavonoides Improves Plasma Levels of Adipocyte Hormones

    Directory of Open Access Journals (Sweden)

    Boncheva M.

    2014-12-01

    Full Text Available Since time immemorial the fruits of aronia melanocarpa (rich of bioflavonoides have been known for their medicinal properties. Present-day research of the pharmacological effects of aronia melanocarpa juice and fruits intake indicates that their high contents of anthocyanins is closely related to the health enhancing properties of this plant. This is a key fact which can be used in the prevention of most commonly spread, socially significant diseases, reducing for instance the total risk of cardio-vascular diseases. The great molecular variety anthocyanins possess and the role they play in cell metabolism, are still being investigated. This gives grounds to study the effects of Aronia melanocarpa on human cells, tissues, and organs. The aim of this study is to trace the effect of 150-200 ml aronia melanokarpa juice daily oral intake on the adipocyte hormones leptin (Lp, resistine (Rs and adiponectin (Adn blood levels in 10 patients with high body mass index (BMI, kg/m2 and high waist circumference. We used ELISA methods for hormonal analyses. During the study-period of two months patients did not change anything in their lifestyle. In the study group, the levels of Rs, Lp and Adn changed significantly compared to their baseline levels (averages, ng/mL - 6.93 ± 0.137, 18.40 ±1.021 and 7.98 ± 0.077 vs. 5.06 ± 0.011, 15.23 ± 0.906 and 10.45 ± 0.103 at the end of the second month, respectively. Compared with the control group of 6 people, matched for BMI, not receiving aronia melanocarpa juice, these values were markedly different. Patients taking aronia melanokarpa juice report improvement in various conditions that have caused them discomfort before the research started: pain in the muscles and joints faded away and were replaced by a new feeling of strength, headache attacks disappeared, improvement in memory and sleep were reported, regular defecation, no signs of gastric discomfort, better vision, a quicker auditory reaction, motivation

  17. Transdifferentiation of adipocytes to osteoblasts: potential for orthopaedic treatment.

    Science.gov (United States)

    Lin, Daphne P L; Dass, Crispin R

    2018-03-01

    As both adipocytes and osteoblasts originate from the same pool of mesenchymal stem cells, increasing clinical evidence has emerged of the plasticity between the two lineages. For instance, the downregulation of osteoblast differentiation and upregulation of adipogenesis are common features of conditions such as multiple myeloma, obesity and drug-induced bone loss in diabetes mellitus. However, despite in-vitro and in-vivo observations of adipocyte transdifferentiation into osteoblasts, little is known of the underlying mechanisms. This review summarises the current knowledge of this particular transdifferentiation process whereby the Wnt/β-catenin signalling pathway and Runx2 overexpression have been postulated to play a critical role. Furthermore, due to the possibility of a novel therapy in the treatment of bone conditions, a number of agents with the potential to induce adipo-to-osteoblast transdifferentiation have been investigated such as all-trans retinoic acid, bone morphogenetic protein-9 and vascular endothelial growth factor. © 2018 Royal Pharmaceutical Society.

  18. Quantitative analysis of secretome from adipocytes regulated by insulin

    Institute of Scientific and Technical Information of China (English)

    Hu Zhou; Yuanyuan Xiao; Rongxia Li; Shangyu Hong; Sujun Li; Lianshui Wang; Rong Zeng; Kan Liao

    2009-01-01

    Adipocyte is not only a central player involved in storage and release of energy, but also in regulation of energy metabolism in other organs via secretion of pep-tides and proteins. During the pathogenesis of insulin resistance and type 2 diabetes, adipocytes are subjected to the increased levels of insulin, which may have a major impact on the secretion of adipokines. We have undertaken cleavable isotope-coded affinity tag (clCAT) and label-free quantitation approaches to identify and quantify secretory factors that are differen-tially secreted by 3T3-LI adipocytes with or without insulin treatment. Combination of clCAT and label-free results, there are 317 proteins predicted or annotated as secretory proteins. Among these secretory proteins, 179 proteins and 53 proteins were significantly up-regulated and down-regulated, respectively. A total of 77 reported adipokines were quantified in our study, such as adiponectin, cathepsin D, cystatin C, resistin, and transferrin. Western blot analysis of these adipo-kines confirmed the quantitative results from mass spectrometry, and revealed individualized secreting pat-terns of these proteins by increasing insulin dose. In addition, 240 proteins were newly identified and quanti-fied as secreted proteins from 3T3-L1 adipocytes in our study, most of which were up-regulated upon insulin treatment. Further comprehensive bioinformatics analysis revealed that the secretory proteins in extra-cellular matrix-receptor interaction pathway and glycan structure degradation pathway were significantly up-regulated by insulin stimulation.

  19. Adipocyte and leptin accumulation in tumor-induced thymic involution.

    Science.gov (United States)

    Lamas, Alejandro; Lopez, Elena; Carrio, Roberto; Lopez, Diana M

    2016-01-01

    Cell-mediated immunity is an important defense mechanism against pathogens and developing tumor cells. The thymus is the main lymphoid organ involved in the formation of the cell-mediated immune response by the maturation and differentiation of lymphocytes that travel from the bone marrow, through the lymphatic ducts, to become T lymphocytes. Thymic involution has been associated with aging; however, other factors such as obesity, viral infection and tumor development have been shown to increase the rate of shrinkage of this organ. The heavy infiltration of adipocyte fat cells has been reported in the involuted thymuses of aged mice. In the present study, the possible accumulation of such cells in the thymus during tumorigenesis was examined by immunohistochemistry. A significant number of adipocytes around and infiltrating the thymuses of tumor-bearing mice was observed. Leptin is a pro-inflammatory adipocytokine that enhances thymopoiesis and modulates T cell immune responses. The levels of leptin and adiponectin, another adipocytokine that has anti-inflammatory properties, were examined by western blot analysis. While no changes were observed in the amounts of adiponectin present in the thymuses of the normal and tumor-bearing mice, significantly higher levels of leptin were detected in the thymocytes of the tumor-bearing mice. This correlated with an increase in the expression of certain cytokines, such as interleukin (IL)-2, interferon (IFN)-γ and granulocyte-macrophage colony-stimulating factor (GM-CSF). The co-culture of thymocytes isolated from normal mice with ex vivo isolated adipocytes from tumor-bearing mice yielded similar results. Our findings suggest that the infiltration and accumulation of adipocytes in the thymuses of tumor-bearing mice play an important role in their altered morphology and functions.

  20. The Effect of Crataegi Fructus Pharmacopuncture on Adipocyte Metabolism

    Directory of Open Access Journals (Sweden)

    Seung Hwan, Won

    2008-06-01

    Full Text Available Objectives : The purpose of this study is to investigate the effects of Crataegi Fructus Pharmacopuncture(CFP on the adipogenesis in 3T3-L1 cells, lipolysis in rat epididymal adipocytes and histological changes in porcine adipose tissue. Methods : Inhibiton of preadipocyte differentiation and/or stimulation of lipolysis play important roles in reducing obesity. 3T3-L1 preadipocytes were differentiated with adipogenic reagents by incubating for 3days in the absence or presence of CFP ranging from 0.01 to 1mg/mL. The effect of CFP on adipogenesis was examined by measuring GPDH activity and by Oil Red O staining. Mature adipocytes from rat epididymal fat pad was incubated with CFP ranging from 0.01 to 1mg/mL for 3 hrs. The effect of CFP on lipolysis was examined by measuring free glycerol released. Fat tissue from pig skin was injected with CFP ranging from 0.1 to 10mg/mL to examine the effect of CFP on histological changes under light microscopy. Results : The following results were obtained from present study on adipogenesis of preadipocytes, lipolysis of adipocytes and histological changes in fat tissue. 1. Crataegi Fructus Pharmacopuncture inhibited adipogenic differentiation at the concentration of 1.0mg/mL 2. Crataegi Fructus Pharmacopuncture decreased the activity of glycerol-3-phosphate dehydrogenase(GPDH at the concentration of 0.1mg/mL. 3. Crataegi Fructus Pharmacopuncture ok. lipolysis at the concentration of 0.1mg/ml. 4. Crataegi Fructus Pharmacopuncture ranging 0.1 to 10mg/mL failed to exert lysis of cell membrane in porcine fat tissue. Conclusions : These results suggest that Crataegi Fructus Pharmacopuncture at relatively high concentration inhibited adipogenesis and increased lipolysis of adipocytes. However, Crataegi Fructus Pharmacopuncture didn’t exert any effect on lysis of cell membrane in fat tissue.

  1. ATF3 inhibits PPARγ-stimulated transactivation in adipocyte cells

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Min-Kyung; Jung, Myeong Ho, E-mail: jung0603@pusan.ac.kr

    2015-01-02

    Highlights: • ATF3 inhibits PPARγ-stimulated transcriptional activation. • ATF3 interacts with PPARγ. • ATF3 suppresses p300-mediated transcriptional coactivation. • ATF3 decreases the binding of PPARγ and recruitment of p300 to PPRE. - Abstract: Previously, we reported that activating transcription factor 3 (ATF3) downregulates peroxisome proliferator activated receptor (PPARγ) gene expression and inhibits adipocyte differentiation in 3T3-L1 cells. Here, we investigated another role of ATF3 on the regulation of PPARγ activity. ATF3 inhibited PPARγ-stimulated transactivation of PPARγ responsive element (PPRE)-containing reporter or GAL4/PPARγ chimeric reporter. Thus, ATF3 effectively repressed rosiglitazone-stimulated expression of adipocyte fatty acid binding protein (aP2), PPARγ target gene, in 3T3-L1 cells. Coimmunoprecipitation and GST pulldown assay demonstrated that ATF3 interacted with PPARγ. Accordingly, ATF3 prevented PPARγ from binding to PPRE on the aP2 promoter. Furthermore, ATF3 suppressed p300-mediated transcriptional coactivation of PPRE-containing reporter. Chromatin immunoprecipitation assay showed that overexpression of ATF3 blocked both binding of PPARγ and recruitment of p300 to PPRE on aP2 promoter induced by rosiglitazone treatment in 3T3-L1 cells. Taken together, these results suggest that ATF3 interacts with PPARγ and represses PPARγ-mediated transactivation through suppression of p300-stimulated coactivation in 3T3-L1 cells, which may play a role in inhibition of adipocyte differentiation.

  2. 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.

  3. Effect of physical training on glucose transporter protein and mRNA levels in rat adipocytes

    DEFF Research Database (Denmark)

    Stallknecht, B; Andersen, P H; Vinten, J

    1993-01-01

    Physical training increases insulin-stimulated glucose transport and the number of glucose transporters in adipocytes measured by cytochalasin B binding. In the present study we used immunoblotting to measure the abundance of two glucose transporters (GLUT-4, GLUT-1) in white adipocytes from....../or intrinsic activity). GLUT-1 protein and mRNA levels/adipocyte volume did not change with age or training....

  4. ATF3 represses PPARγ expression and inhibits adipocyte differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Min-Kyung; Jung, Myeong Ho, E-mail: jung0603@pusan.ac.kr

    2014-11-07

    Highlights: • ATF3 decrease the expression of PPARγ and its target gene in 3T3-L1 adipocytes. • ATF3 represses the promoter activity of PPARγ2 gene. • ATF/CRE (−1537/−1530) is critical for ATF3-mediated downregulation of PPARγ. • ATF3 binds to the promoter region containing the ATF/CRE. • ER stress inhibits adipocyte differentiation through downregulation of PPARγ by ATF3. - Abstract: Activating transcription factor 3 (ATF3) is a stress-adaptive transcription factor that mediates cellular stress response signaling. We previously reported that ATF3 represses CCAAT/enhancer binding protein α (C/EBPα) expression and inhibits 3T3-L1 adipocyte differentiation. In this study, we explored potential role of ATF3 in negatively regulating peroxisome proliferator activated receptor-γ (PPARγ). ATF3 decreased the expression of PPARγ and its target gene in 3T3-L1 adipocytes. ATF3 also repressed the activity of −2.6 Kb promoter of mouse PPARγ2. Overexpression of PPARγ significantly prevented the ATF3-mediated inhibition of 3T3-L1 differentiation. Transfection studies with 5′ deleted-reporters showed that ATF3 repressed the activity of −2037 bp promoter, whereas it did not affect the activity of −1458 bp promoter, suggesting that ATF3 responsive element is located between the −2037 and −1458. An electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that ATF3 binds to ATF/CRE site (5′-TGACGTTT-3′) between −1537 and −1530. Mutation of the ATF/CRE site abrogated ATF3-mediated transrepression of the PPARγ2 promoter. Treatment with thapsigargin, endoplasmic reticulum (ER) stress inducer, increased ATF3 expression, whereas it decreased PPARγ expression. ATF3 knockdown significantly blocked the thapsigargin-mediated downregulation of PPARγ expression. Furthermore, overexpression of PPARγ prevented inhibition of 3T3-L1 differentiation by thapsigargin. Collectively, these results suggest that ATF3-mediated

  5. Actin depolymerization enhances adipogenic differentiation in human stromal stem cells

    DEFF Research Database (Denmark)

    Chen, Li; Hu, Huimin; Qiu, Weimin

    2018-01-01

    Human stromal stem cells (hMSCs) differentiate into adipocytes that play a role in skeletal tissue homeostasis and whole body energy metabolism. During adipocyte differentiation, hMSCs exhibit significant changes in cell morphology suggesting changes in cytoskeletal organization. Here, we examined...... the effect of direct modulation of actin microfilament dynamics on adipocyte differentiation. Stabilizing actin filaments in hMSCs by siRNA-mediated knock down of the two main actin depolymerizing factors (ADFs): Cofilin 1 (CFL1) and Destrin (DSTN) or treating the cells by Phalloidin reduced adipocyte...

  6. Actin depolymerization enhances adipogenic differentiation in human stromal stem cells

    Directory of Open Access Journals (Sweden)

    Li Chen

    2018-05-01

    Full Text Available Human stromal stem cells (hMSCs differentiate into adipocytes that play a role in skeletal tissue homeostasis and whole body energy metabolism. During adipocyte differentiation, hMSCs exhibit significant changes in cell morphology suggesting changes in cytoskeletal organization. Here, we examined the effect of direct modulation of actin microfilament dynamics on adipocyte differentiation. Stabilizing actin filaments in hMSCs by siRNA-mediated knock down of the two main actin depolymerizing factors (ADFs: Cofilin 1 (CFL1 and Destrin (DSTN or treating the cells by Phalloidin reduced adipocyte differentiation as evidenced by decreased number of mature adipocytes and decreased adipocyte specific gene expression (ADIPOQ, LPL, PPARG, FABP4. In contrast, disruption of actin cytoskeleton by Cytochalasin D enhanced adipocyte differentiation. Follow up studies revealed that the effects of CFL1 on adipocyte differentiation depended on the activity of LIM domain kinase 1 (LIMK1 which is the major upstream kinase of CFL1. Inhibiting LIMK by its specific chemical inhibitor LIMKi inhibited the phosphorylation of CFL1 and actin polymerization, and enhanced the adipocyte differentiation. Moreover, treating hMSCs by Cytochalasin D inhibited ERK and Smad2 signaling and this was associated with enhanced adipocyte differentiation. On the other hand, Phalloidin enhanced ERK and Smad2 signaling, but inhibited adipocyte differentiation which was rescued by ERK specific chemical inhibitor U0126. Our data provide a link between restructuring of hMSCs cytoskeleton and hMSCs lineage commitment and differentiation. Keywords: Actin cytoskeleton, Actin depolymerizing factors, Adipocyte differentiation, Human stromal stem cells

  7. ApoB100-LDL acts as a metabolic signal from liver to peripheral fat causing inhibition of lipolysis in adipocytes.

    Directory of Open Access Journals (Sweden)

    Josefin Skogsberg

    Full Text Available BACKGROUND: Free fatty acids released from adipose tissue affect the synthesis of apolipoprotein B-containing lipoproteins and glucose metabolism in the liver. Whether there also exists a reciprocal metabolic arm affecting energy metabolism in white adipose tissue is unknown. METHODS AND FINDINGS: We investigated the effects of apoB-containing lipoproteins on catecholamine-induced lipolysis in adipocytes from subcutaneous fat cells of obese but otherwise healthy men, fat pads from mice with plasma lipoproteins containing high or intermediate levels of apoB100 or no apoB100, primary cultured adipocytes, and 3T3-L1 cells. In subcutaneous fat cells, the rate of lipolysis was inversely related to plasma apoB levels. In human primary adipocytes, LDL inhibited lipolysis in a concentration-dependent fashion. In contrast, VLDL had no effect. Lipolysis was increased in fat pads from mice lacking plasma apoB100, reduced in apoB100-only mice, and intermediate in wild-type mice. Mice lacking apoB100 also had higher oxygen consumption and lipid oxidation. In 3T3-L1 cells, apoB100-containing lipoproteins inhibited lipolysis in a dose-dependent fashion, but lipoproteins containing apoB48 had no effect. ApoB100-LDL mediated inhibition of lipolysis was abolished in fat pads of mice deficient in the LDL receptor (Ldlr(-/-Apob(100/100. CONCLUSIONS: Our results show that the binding of apoB100-LDL to adipocytes via the LDL receptor inhibits intracellular noradrenaline-induced lipolysis in adipocytes. Thus, apoB100-LDL is a novel signaling molecule from the liver to peripheral fat deposits that may be an important link between atherogenic dyslipidemias and facets of the metabolic syndrome.

  8. Synergistic effects of leucine and resveratrol on insulin sensitivity and fat metabolism in adipocytes and mice

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    Bruckbauer Antje

    2012-08-01

    Full Text Available Abstract Background Sirtuins are important regulators of glucose and fat metabolism, and sirtuin activation has been proposed as a therapeutic target for insulin resistance and diabetes. We have shown leucine to increase mitochondrial biogenesis and fat oxidation via Sirt1 dependent pathways. Resveratrol is a widely recognized activator of Sirt; however, the biologically-effective high concentrations used in cell and animal studies are generally impractical or difficult to achieve in humans. Accordingly, we sought to determine whether leucine would exhibit synergy with low levels of resveratrol on sirtuin-dependent outcomes in adipocytes and in diet-induced obese (DIO mice. Methods 3T3-L1 mouse adipocytes were treated with Leucine (0.5 mM, β-hydroxy-β-methyl butyrate (HMB (5 μM or Resveratrol (200 nM alone or in combination. In addition, diet-induced obese mice were treated for 6-weeks with low (2 g/kg diet or high (10 g/kg diet dose HMB, Leucine (24 g/kg diet; 200% of normal level or low (12.5 mg/kg diet or high (225 mg/kg diet dose resveratrol, alone or as combination with leucine-resveratrol or HMB-resveratrol. Results Fatty acid oxidation, AMPK, Sirt1 and Sirt3 activity in 3T3-L1 adipocytes and in muscle cells, were significantly increased by the combinations compared to the individual treatments. Similarly, 6-week feeding of low-dose resveratrol combined with either leucine or its metabolite HMB to DIO mice increased adipose Sirt1 activity, muscle glucose and palmitate uptake (measured via PET/CT, insulin sensitivity (HOMAIR, improved inflammatory stress biomarkers (CRP, IL-6, MCP-1, adiponectin and reduced adiposity comparable to the effects of high dose resveratrol, while low-dose resveratrol exerted no independent effect. Conclusion These data demonstrate that either leucine or its metabolite HMB may be combined with a low concentration of resveratrol to exert synergistic effects on Sirt1-dependent outcomes; this may result in more

  9. Chelation of intracellular calcium blocks insulin action in the adipocyte

    International Nuclear Information System (INIS)

    Pershadsingh, H.A.; Shade, D.L.; Delfert, D.M.; McDonald, J.M.

    1987-01-01

    The hypothesis that intracellular Ca 2+ is an essential component of the intracellular mechanism of insulin action in the adipocyte was evaluated. Cells were loaded with the Ca 2+ chelator quin-2, by preincubating them with quin-2 AM, the tetrakis(acetoxymethyl) ester of quin-2. Quin-2 loading inhibited insulin-stimulated glucose transport without affecting basal activity. The ability of insulin to stimulate glucose uptake in quin-2-loaded cells could be partially restored by preincubating cells with buffer supplemented with 1.2 mM CaCl 2 and the Ca 2+ ionophore A23187. These conditions had no effect on basal activity and omission of CaCl 2 from the buffer prevented the restoration of insulin-stimulated glucose uptake by A23187. Quin-2 loading also inhibited insulin-stimulated glucose oxidation and the ability of insulin to inhibit cAMP-stimulated lipolysis without affecting their basal activities. Incubation of cells with 100 μM quin-2 or quin-2 AM had no effect on intracellular ATP concentration or the specific binding of 125 I=labeled insulin to adipocytes. These findings suggest that intracellular Ca 2+ is an essential component in the coupling of the insulin-activated receptor complex to cellular physiological/metabolic machinery. Furthermore, differing quin-2 AM dose-response profiles suggest the presence of dual Ca 2+ -dependent pathways in the adipocyte. One involves insulin stimulation of glucose transport and oxidation, whereas the other involves the antilipolytic action of insulin

  10. Limited OXPHOS capacity in white adipocytes is a hallmark of obesity in laboratory mice irrespective of the glucose tolerance status

    Directory of Open Access Journals (Sweden)

    Theresa Schöttl

    2015-09-01

    Conclusion: Reduced mitochondrial respiratory capacity in white adipocytes is a hallmark of murine obesity irrespective of the glucose tolerance status. Impaired respiratory capacity in white adipocytes solely is not sufficient for the development of systemic glucose intolerance.

  11. The estrogen-related receptors and the adipocyte.

    Science.gov (United States)

    Carnesecchi, Julie; Vanacker, Jean-Marc

    2013-08-01

    The estrogen-related receptors (ERRα, β, and γ) are orphan members of the nuclear receptor superfamily. ERRα and γ are highly expressed in tissues displaying elevated energy demands and are involved in several aspects of energetic metabolism, which they regulate mostly in association with members of the PGC-1 coactivator family. These activities have mostly been documented in the liver, heart, or skeletal muscle. ERRα and γ are also highly expressed in adipocytes. Their precise roles in this cell type are less documented, although published data indicate that they contribute to cell differentiation as well as functionality. This review describes these activities.

  12. RNA-binding protein PSPC1 promotes the differentiation-dependent nuclear export of adipocyte RNAs

    DEFF Research Database (Denmark)

    Wang, Jiexin; Rajbhandari, Prashant; Damianov, Andrey

    2017-01-01

    A highly orchestrated gene expression program establishes the properties that define mature adipocytes, but the contribution of posttranscriptional factors to the adipocyte phenotype is poorly understood. Here we have shown that the RNA-binding protein PSPC1, a component of the paraspeckle complex...

  13. Characterization of murine melanocortin receptors mediating adipocyte lipolysis and examination of signalling pathways involved

    DEFF Research Database (Denmark)

    Møller, Cathrine Laustrup; Raun, Kirsten; Jacobsen, Marianne Lambert

    2011-01-01

    hormone (a-MSH) generated from proopiomelanocortin (POMC), as well as synthetic MSH analogues to stimulate lipolysis in murine 3T3-L1 adipocytes it is shown that MC2R and MC5R are lipolytic mediators in differentiated 3T3-L1 adipocytes. Involvement of cAMP, phosphorylated extracellular signal...

  14. In-depth analysis of the adipocyte proteome by mass spectrometry and bioinformatics

    DEFF Research Database (Denmark)

    Adachi, Jun; Kumar, Chanchal; Zhang, Yanling

    2007-01-01

    , mitochondria, membrane, and cytosol of 3T3-L1 adipocytes. We identified 3,287 proteins while essentially eliminating false positives, making this one of the largest high confidence proteomes reported to date. Comprehensive bioinformatics analysis revealed that the adipocyte proteome, despite its specialized...

  15. Regulation of white and brown adipocyte differentiation by RhoGAP DLC1.

    Directory of Open Access Journals (Sweden)

    Choon Kiat Sim

    Full Text Available Adipose tissues constitute an important component of metabolism, the dysfunction of which can cause obesity and type II diabetes. Here we show that differentiation of white and brown adipocytes requires Deleted in Liver Cancer 1 (DLC1, a Rho GTPase Activating Protein (RhoGAP previously studied for its function in liver cancer. We identified Dlc1 as a super-enhancer associated gene in both white and brown adipocytes through analyzing the genome-wide binding profiles of PPARγ, the master regulator of adipogenesis. We further observed that Dlc1 expression increases during differentiation, and knockdown of Dlc1 by siRNA in white adipocytes reduces the formation of lipid droplets and the expression of fat marker genes. Moreover, knockdown of Dlc1 in brown adipocytes reduces expression of brown fat-specific genes and diminishes mitochondrial respiration. Dlc1-/- knockout mouse embryonic fibroblasts show a complete inability to differentiate into adipocytes, but this phenotype can be rescued by inhibitors of Rho-associated kinase (ROCK and filamentous actin (F-actin, suggesting the involvement of Rho pathway in DLC1-regulated adipocyte differentiation. Furthermore, PPARγ binds to the promoter of Dlc1 gene to regulate its expression during both white and brown adipocyte differentiation. These results identify DLC1 as an activator of white and brown adipocyte differentiation, and provide a molecular link between PPARγ and Rho pathways.

  16. Mammary alveolar epithelial cells convert to brown adipocytes in post-lactating mice

    DEFF Research Database (Denmark)

    Giordano, Antonio; Perugini, Jessica; Kristensen, David Møbjerg

    2017-01-01

    During pregnancy and lactation, subcutaneous white adipocytes in the mouse mammary gland transdifferentiate reversibly to milk-secreting epithelial cells. In this study, we demonstrate by transmission electron microscopy that in the post-lactating mammary gland interscapular multilocular adipocyt...... organ plasticity...

  17. Regulation of proliferation and differentiation of adipocyte precursor cells in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Bouraoui, L; Gutiérrez, J; Navarro, I

    2008-09-01

    Here, we describe optimal conditions for the culture of rainbow trout (Oncorhynchus mykiss) pre-adipocytes obtained from adipose tissue and their differentiation into mature adipocytes, in order to study the endocrine control of adipogenesis. Pre-adipocytes were isolated by collagenase digestion and cultured on laminin or 1% gelatin substrate. The expression of proliferating cell nuclear antigen was used as a marker of cell proliferation on various days of culture. Insulin growth factor-I stimulated cell proliferation especially on days 5 and 7 of culture. Tumor necrosis factor alpha (TNFalpha) slightly enhanced cell proliferation only at a low dose. We verified the differentiation of cells grown in specific medium into mature adipocytes by oil red O (ORO) staining. Quantification of ORO showed an increase in triglycerides throughout culture. Immunofluorescence staining of cells at day 11 revealed the expression of CCAAT/enhancer-binding protein and peroxisome proliferator-activator receptor gamma, suggesting that these transcriptional factors are involved in adipocyte differentiation in trout. We also examined the effect of TNFalpha on the differentiation of these adipocytes in primary culture. TNFalpha inhibited the differentiation of these cells, as indicated by a decrease in glycerol-3-phosphate dehydrogenase activity, an established marker of adipocyte differentiation. In conclusion, the culture system described here for trout pre-adipocytes is a powerful tool to study the endocrine regulation of adipogenesis in this species.

  18. 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.

  19. Deficiency of the GPR39 receptor is associated with obesity and altered adipocyte metabolism

    DEFF Research Database (Denmark)

    Petersen, Pia Steen; Jin, Chunyu; Madsen, Andreas Nygaard

    2011-01-01

    , conceivably due to decreased energy expenditure and adipocyte lipolytic activity.-Petersen, P. S., Jin, C., Madsen, A. N., Rasmussen, M., Kuhre, R., L. Egerod, K. L., Nielsen, L. B., Schwartz. T. W., Holst, B. Deficiency of the GPR39 receptor is associated with obesity and altered adipocyte metabolism....

  20. SREBP-1c/MicroRNA 33b Genomic Loci Control Adipocyte Differentiation

    Science.gov (United States)

    Price, Nathan L.; Holtrup, Brandon; Kwei, Stephanie L.; Wabitsch, Martin; Rodeheffer, Matthew; Bianchini, Laurence; Suárez, Yajaira

    2016-01-01

    White adipose tissue (WAT) is essential for maintaining metabolic function, especially during obesity. The intronic microRNAs miR-33a and miR-33b, located within the genes encoding sterol regulatory element-binding protein 2 (SREBP-2) and SREBP-1, respectively, are transcribed in concert with their host genes and function alongside them to regulate cholesterol, fatty acid, and glucose metabolism. SREBP-1 is highly expressed in mature WAT and plays a critical role in promoting in vitro adipocyte differentiation. It is unknown whether miR-33b is induced during or involved in adipogenesis. This is in part due to loss of miR-33b in rodents, precluding in vivo assessment of the impact of miR-33b using standard mouse models. This work demonstrates that miR-33b is highly induced upon differentiation of human preadipocytes, along with SREBP-1. We further report that miR-33b is an important regulator of adipogenesis, as inhibition of miR-33b enhanced lipid droplet accumulation. Conversely, overexpression of miR-33b impaired preadipocyte proliferation and reduced lipid droplet formation and the induction of peroxisome proliferator-activated receptor γ (PPARγ) target genes during differentiation. These effects may be mediated by targeting of HMGA2, cyclin-dependent kinase 6 (CDK6), and other predicted miR-33b targets. Together, these findings demonstrate a novel role of miR-33b in the regulation of adipocyte differentiation, with important implications for the development of obesity and metabolic disease. PMID:26830228

  1. Obesity-induced DNA released from adipocytes stimulates chronic adipose tissue inflammation and insulin resistance.

    Science.gov (United States)

    Nishimoto, Sachiko; Fukuda, Daiju; Higashikuni, Yasutomi; Tanaka, Kimie; Hirata, Yoichiro; Murata, Chie; Kim-Kaneyama, Joo-Ri; Sato, Fukiko; Bando, Masahiro; Yagi, Shusuke; Soeki, Takeshi; Hayashi, Tetsuya; Imoto, Issei; Sakaue, Hiroshi; Shimabukuro, Michio; Sata, Masataka

    2016-03-01

    Obesity stimulates chronic inflammation in adipose tissue, which is associated with insulin resistance, although the underlying mechanism remains largely unknown. Here we showed that obesity-related adipocyte degeneration causes release of cell-free DNA (cfDNA), which promotes macrophage accumulation in adipose tissue via Toll-like receptor 9 (TLR9), originally known as a sensor of exogenous DNA fragments. Fat-fed obese wild-type mice showed increased release of cfDNA, as determined by the concentrations of single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) in plasma. cfDNA released from degenerated adipocytes promoted monocyte chemoattractant protein-1 (MCP-1) expression in wild-type macrophages, but not in TLR9-deficient (Tlr9 (-/-) ) macrophages. Fat-fed Tlr9 (-/-) mice demonstrated reduced macrophage accumulation and inflammation in adipose tissue and better insulin sensitivity compared with wild-type mice, whereas bone marrow reconstitution with wild-type bone marrow restored the attenuation of insulin resistance observed in fat-fed Tlr9 (-/-) mice. Administration of a TLR9 inhibitory oligonucleotide to fat-fed wild-type mice reduced the accumulation of macrophages in adipose tissue and improved insulin resistance. Furthermore, in humans, plasma ssDNA level was significantly higher in patients with computed tomography-determined visceral obesity and was associated with homeostasis model assessment of insulin resistance (HOMA-IR), which is the index of insulin resistance. Our study may provide a novel mechanism for the development of sterile inflammation in adipose tissue and a potential therapeutic target for insulin resistance.

  2. Adipocyte-specific protein tyrosine phosphatase 1B deletion increases lipogenesis, adipocyte cell size and is a minor regulator of glucose homeostasis.

    Directory of Open Access Journals (Sweden)

    Carl Owen

    Full Text Available Protein tyrosine phosphatase 1B (PTP1B, a key negative regulator of leptin and insulin signaling, is positively correlated with adiposity and contributes to insulin resistance. Global PTP1B deletion improves diet-induced obesity and glucose homeostasis via enhanced leptin signaling in the brain and increased insulin signaling in liver and muscle. However, the role of PTP1B in adipocytes is unclear, with studies demonstrating beneficial, detrimental or no effect(s of adipose-PTP1B-deficiency on body mass and insulin resistance. To definitively establish the role of adipocyte-PTP1B in body mass regulation and glucose homeostasis, adipocyte-specific-PTP1B knockout mice (adip-crePTP1B(-/- were generated using the adiponectin-promoter to drive Cre-recombinase expression. Chow-fed adip-crePTP1B(-/- mice display enlarged adipocytes, despite having similar body weight/adiposity and glucose homeostasis compared to controls. High-fat diet (HFD-fed adip-crePTP1B(-/- mice display no differences in body weight/adiposity but exhibit larger adipocytes, increased circulating glucose and leptin levels, reduced leptin sensitivity and increased basal lipogenesis compared to controls. This is associated with decreased insulin receptor (IR and Akt/PKB phosphorylation, increased lipogenic gene expression and increased hypoxia-induced factor-1-alpha (Hif-1α expression. Adipocyte-specific PTP1B deletion does not beneficially manipulate signaling pathways regulating glucose homeostasis, lipid metabolism or adipokine secretion in adipocytes. Moreover, PTP1B does not appear to be the major negative regulator of the IR in adipocytes.

  3. Identification of a subpopulation of marrow MSC-derived medullary adipocytes that express osteoclast-regulating molecules: marrow adipocytes express osteoclast mediators.

    Directory of Open Access Journals (Sweden)

    Vance Holt

    Full Text Available Increased marrow medullary adipogenesis and an associated decrease in bone mineral density, usually observed in elderly individuals, is a common characteristic in senile osteoporosis. In this study we investigated whether cells of the medullary adipocyte lineage have the potential to directly support the formation of osteoclasts, whose activity in bone leads to bone degradation. An in vitro mesenchymal stem cell (MSC-derived medullary adipocyte lineage culture model was used to study the expression of the important osteoclast mediators RANKL, M-CSF, SDF-1, and OPG. We further assessed whether adipocytes at a specific developmental stage were capable of supporting osteoclast-like cell formation in culture. In vitro MSC-derived medullary adipocytes showed an mRNA and protein expression profile of M-CSF, RANKL, and OPG that was dependent on its developmental/metabolic stage. Furthermore, RANKL expression was observed in MSC-derived adipocytes that were at a distinct lineage stage and these cells were also capable of supporting osteoclast-like cell formation in co-cultures with peripheral blood mononuclear cells. These results suggest a connection between medullary adipocytes and osteoclast formation in vivo and may have major significance in regards to the mechanisms of decreased bone density in senile osteoporosis.

  4. Methylation of miR-145a-5p promoter mediates adipocytes differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jingjing; Cheng, Xiao; Shen, Linyuan; Tan, Zhendong; Luo, Jia; Wu, Xiaoqian; Liu, Chendong [College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130 (China); Yang, Qiong [Department of Animal Husbandry and Veterinary Medicine, Chengdu Agricultural College, Chengdu 611100, Sichuan (China); Jiang, Yanzhi [College of Life and Science, Sichuan Agricultural University, Chengdu 611130 (China); Tang, Guoqing; Li, Xuewei [College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130 (China); Zhang, Shunhua, E-mail: zhangsh1919@163.com [College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130 (China); Zhu, Li, E-mail: zhuli7508@163.com [College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130 (China)

    2016-06-17

    MicroRNAs (miRNAs, miR) play important roles in adipocyte development. Recent studies showed that the expression of several miRNAs is closely related with promoter methylation. However, it is not known whether miRNA mediates adipocytes differentiation by means of DNA methylation. Here, we showed that miR-145a-5p was poorly expressed in adipose tissue from mice fed a high fat diet (HFD). Overexpression or inhibition of miR-145a-5p was unfavorable or beneficial, respectively, for adipogenesis, and these effects were achieved by regulating adipocyte-specific genes involved in lipogenic transcription, fatty acid synthesis, and fatty acid transportation. Particularly, we first suggested that miR-145a-5p mimics or inhibitors promoted or repressed adipocytes proliferation by regulating p53 and p21, which act as cell cycle regulating factors. Surprisingly, the miR-145a-5p-repressed adipocyte differentiation was enhanced or rescued when cells treated with 5-Aza-dC were transfected with miR-145a-5p mimics or inhibitors, respectively. These data indicated that, as a new mean to positively regulate adipocyte proliferation, the process of miR-145a-5p-inhibited adipogenesis may be regulated by DNA methylation. -- Highlights: •MiR-145a-5p promotes adipocytes proliferation. •MiR-145a-5p is negatively correlated with obesity. •MiR-145a-5p mediates adipocytes differentiation via regulating pathway related adipocytes differentiation. MiR-145a-5p mediating adipocytes differentiation was regulated by DNA methylation.

  5. Adipocyte glucose transport regulation by eicosanoid precursors and inhibitors

    International Nuclear Information System (INIS)

    Lee, H.C.C.

    1987-01-01

    Glucose uptake and free fatty acid release by adipocytes are increased by catecholamines. The mechanism of the stimulatory action of catecholamines on glucose uptake may be via eicosanoid production from release fatty acids. Rats were fed iso-nutrient diets with high or low safflower oil. After one month, 5 rats per diet group were fed diets with aspirin or without aspirin for 2 days. Isolated adipocytes from epididymal fat pads were incubated at 37 0 C, gassed with 95% O 2 -5% CO 2 in KRB buffer with 3% bovine serum albumin and with or without eicosanoid modifiers; a stimulator (10 -5 M norepinephrine, N), or inhibitors (167 μl of antiserum to prostaglandin E (AntiE) per 1600 μl or 23mM Asp), or combinations of these. At 2-, 5-, and 10-min incubation, samples of incubation mixtures were taken to measure 2-deoxy glucose transport using 3 H-2-deoxy glucose, 14 C-inulin, and liquid scintillation counter

  6. 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.

  7. γ-Oryzanol Enhances Adipocyte Differentiation and Glucose Uptake.

    Science.gov (United States)

    Jung, Chang Hwa; Lee, Da-Hye; Ahn, Jiyun; Lee, Hyunjung; Choi, Won Hee; Jang, Young Jin; Ha, Tae-Youl

    2015-06-15

    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.

  8. 11-Hydroxy-β-steroid dehydrogenase gene expression in canine adipose tissue and adipocytes: stimulation by lipopolysaccharide and tumor necrosis factor α.

    Science.gov (United States)

    Ryan, V H; Trayhurn, P; Hunter, L; Morris, P J; German, A J

    2011-10-01

    The enzyme 11β-hydroxysteroid dehydrogenase 1 (11β-HSD-1) is expressed in a number of tissues in rodents and humans and is responsible for the reactivation of inert cortisone into cortisol. Its gene expression and activity are increased in white adipose tissue (WAT) from obese humans and may contribute to the adverse metabolic consequences of obesity and the metabolic syndrome. The extent to which 11β-HSD-1 contributes to adipose tissue function in dogs is unknown; the aim of the present study was to examine 11β-HSD-1 gene expression and its regulation by proinflammatory and anti-inflammatory agents in canine adipocytes. Real-time PCR was used to examine the expression of 11β-HSD-1 in canine adipose tissue and canine adipocytes differentiated in culture. The mRNA encoding 11β-HSD-1 was identified in all the major WAT depots in dogs and also in liver, kidney, and spleen. Quantification by real-time PCR showed that 11β-HSD-1 mRNA was least in perirenal and falciform depots and greatest in subcutaneous, omental, and gonadal depots. Greater expression was seen in the omental depot in female than in male dogs (P=0.05). Gene expression for 11β-HSD-1 was also seen in adipocytes, from both subcutaneous and visceral depots, differentiated in culture; expression was evident throughout differentiation but was generally greatest in preadipocytes and during early differentiation, declining as cells progressed to maturity. The inflammatory mediators lipopolysaccharide and tumor necrosis factor α had a main stimulatory effect on 11β-HSD-1 gene expression in canine subcutaneous adipocytes, but IL-6 had no significant effect. Treatment with dexamethasone resulted in a significant time- and dose-dependent increase in 11β-HSD-1 gene expression, with greatest effects seen at 24 h (2 nM: approximately 4-fold; 20 nM: approximately 14-fold; P=0.010 for both). When subcutaneous adipocytes were treated with the peroxisome proliferator activated receptor γ agonist rosiglitazone

  9. The Effect of Bangpungtongsung-san Extracts on Adipocyte Metabolism

    Directory of Open Access Journals (Sweden)

    Sang Min, Lee

    2008-03-01

    Full Text Available Objective : The purpose of this study is to investigate the effects of Bangpungtongsung-san extracts on the preadipocytes proliferation, of 3T3-L1 cell line. lipolysis of adipocytes in rat's epididymis and localized fat accumulation of porcine by extraction methods(alcohol and water. Methods : Diminish 3T3-L1 proliferation and lipogenesis do primary role to reduce obesity. So, 3T3-L1 preadipocyte and adipocytes were performed on cell cultures, and using Sprague-Dawley rats for the lipogenesis, and treated with 0.01-1 ㎎/㎖ Bangpungtongsung-san Extracts depend on concentrations. Porcine skin including fat tissue after treated Bangpungtongsung-san Extracts by means of the dosage dependent variation are investigated the histologic changes after injection of these extracts. Results : Following results were obtained from the 3T3-L1 preadipocyte proliferation and lipolysis of adipocyte in rats and histologic investigation of fat tissue. 1. Bangpungtongsung-san extracts were showed the effect of decreased preadipocyte proliferation on the high dosage(1.0㎎/㎖. 2. Bangpungtongsung-san extracts were showed the effect of decreased the activity of glycerol-3-phosphate dehydrogenase(GPDH on the high dosage(1.0㎎/㎖ and Specially, alcohol extract of Bangpungtongsung -san was clear as time goes by high concentration. 3. Bangpungtongsung-san extracts were showed tries to compare the effect of lipolysis, alcohol extract of Bangpungtongsung-san on the high dosage(1.0㎎/㎖ was observed the effect is higher than water extract. 4. Investigated the histological changes in porcine fat tissue after treated Bangpungtongsung-san extracts, we knew that water extract of Bangpungtongsung-san was showed the effect of lipolysis on the high dosage(10.0㎎/㎖ and alcohol extract of Bangpungtongsung-san was showed significant activity to the lysis of cell membranes in all concentration. Conclusion : These results suggest that Bangpungtongsung-san extracts efficiently

  10. Exposure to Tumescent Solution Significantly Increases Phosphorylation of Perilipin in Adipocytes.

    Science.gov (United States)

    Keskin, Ilknur; Sutcu, Mustafa; Eren, Hilal; Keskin, Mustafa

    2017-02-01

    Lidocaine and epinephrine could potentially decrease adipocyte viability, but these effects have not been substantiated. The phosphorylation status of perilipin in adipocytes may be predictive of cell viability. Perilipin coats lipid droplets and restricts access of lipases; phospho-perilipin lacks this protective function. The authors investigated the effects of tumescent solution containing lidocaine and epinephrine on the phosphorylation status of perilipin in adipocytes. In this in vitro study, lipoaspirates were collected before and after tumescence from 15 women who underwent abdominoplasty. Fat samples were fixed, sectioned, and stained for histologic and immunohistochemical analyses. Relative phosphorylation of perilipin was inferred from pixel intensities of immunostained adipocytes observed with confocal microscopy. For adipocytes collected before tumescent infiltration, 10.08% of total perilipin was phosphorylated. In contrast, 30.62% of total perilipin was phosphorylated for adipocytes collected from tumescent tissue (P < .01). The tumescent technique increases the relative phosphorylation of perilipin in adipocytes, making these cells more vulnerable to lipolysis. Tumescent solution applied for analgesia or hemostasis of the donor site should contain the lowest possible concentrations of lidocaine and epinephrine. LEVEL OF EVIDENCE 5. © 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  11. Relationship of adipocyte size to hyperphagia in developing male obese Zucker rats.

    Science.gov (United States)

    Vasselli, J R; Fiene, J A; Maggio, C A

    1992-01-01

    In growing male obese Zucker rats, hyperphagia reaches a maximum or "breakpoint" and declines at an earlier age with high fat than with chow-type diets. A serial adipose tissue biopsy technique was used to correlate changes of retroperitoneal adipocyte size and feeding behavior in 5- to 7-wk-old male lean and obese rats fed laboratory chow or a 35% fat diet until 30 wk of age. Although chow-fed groups had significantly greater cumulative intake, fat-fed groups had significantly greater body weight gain, retroperitoneal depot weight, and adipocyte number. Mean adipocyte size increased continuously in chow-fed groups but decreased over weeks 20-30 in fat-fed groups, reflecting increased adipocyte number. In fat-fed obese rats, hyperphagia reached a breakpoint at 11 wk and disappeared by 13 wk. In chow-fed obese rats, hyperphagia reached a breakpoint at 15-16 wk and disappeared by 19 wk. Biopsy samples revealed that adipocyte size of fat-fed obese rats was already close to maximal at 10 wk (1.12 micrograms lipid), while that of chow-fed obese rats only approached maximal at 20 wk (0.81 microgram lipid). At these time points, lipoprotein lipase activity paralleled adipocyte size. These data indicate that the duration of the growing obese rat's hyperphagia coincides with adipocyte filling and suggest the existence of feeding stimulatory and inhibitory signals from adipose tissue.

  12. The Effect of Growth Hormone on Lipid Accumulation or Maturation in Adipocytes

    Directory of Open Access Journals (Sweden)

    Yuchao Zhang

    2016-11-01

    Full Text Available Background: Adipogenesis of adipocytes includes two stages: initiation and maturation. Growth hormone (GH secretion is decreased in obese subjects and GH levels are inversely correlated with abdominal fat mass. The effects of growth hormone (GH on lipids accumulation or maturation of adipocytes remains elusive. Methods: In the present study, effect of GH on lipid accumulation in vitro and in vivo was examined. cDNA microarray, quantitative real time-PCR (qPCR and western blotting was used to analyze the expression of genes related to adipocyte lipid accumulation or degradation in pre- or mature 3T3-F442A adipocytes treated with GH and in epididymal adipose tissue of C57BL/6 mice administrated with GH. Level of adiponectin in supernatants of cultured F442A adipocytes was determined by enzyme-linked immune-sorbent assay. Results: We found that in 3T3-F442A especially 6 days post initiation of adipogenesis, GH intervention resulted in decreased expression of adipocyte maturation regulators (C/EBPα, PPARγ and prominent genes related to lipid synthesis such as FAS and FABP, while the expression of UCP1 was markedly enhanced. cDNA microarray analysis and qPCR showed that the expression of SOCS2 and Adipor2 was increased under GH-treatment in mature 3T3-F442A adipocytes. GH treatment increased the mRNA expression of adiponectin and UCP1 in mature adipocytes. The above results were confirmed by in vivo study. Conclusions: GH potentially negatively modulates the maturation and accumulation of lipid in adipocytes.

  13. Quantitative changes in adipocyte plasma membrane in response to nutritional manipulations

    International Nuclear Information System (INIS)

    Lewis, D.S.; Masoro, E.J.; Yu, B.P.

    1981-01-01

    The effects of changes in adipocyte size and the effects of nutritional manipulations on the quantity of plasma membrane per adipocyte were investigated. A method for estimating the quantity of plasma membrane was developed based on the specific labeling of adipocyte plasma membrane protein with the nonpermeable labeling agent 125I-labeled diazotized diiodosulfanilic acid. By studying rats (ranging in age from 50 to 125 days) fed a standard laboratory chow or a low fat diet or a high fat diet, a wide range of mean fat cell sizes was obtained. It was found that as the volume of the fat cell increased, the amount of plasma membrane increased in a linear fashion and that this linear relationship had the same slope whether the size of the adipocyte increased slowly with age or rapidly in response to a high fat diet. In contrast, fasting for up to 3 days caused a marked decrease in the mean volume of the adipocytes, but either no change or much less change in the amount of plasma membrane per cell than would have been predicted from the linear relationship between adipocytes, but either no change or much less change in the amount of plasma membrane per cell than would have been predicted form the linear relationship between adipocyte volume and amount of plasma membrane per cell obtained with fed rats, i.e., adipocytes from fasted rats contain more plasma membrane per cell than do fat cells of the same size from fed rats. Neither feeding a high fat diet nor fasting caused detectable changes in the protein and lipid composition of the adipocyte plasma membrane

  14. 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...... physiological or pharmacological conditions. Examining precursors from the purest white adipose tissue depot (epididymal), we report here that chronic treatment with the peroxisome proliferator-activated receptor gamma agonist rosiglitazone promotes not only the expression of PGC-1alpha and mitochondriogenesis...... associated with classic brown adipocytes (Zic1, Lhx8, Meox2, and characteristically PRDM16) or for myocyte-associated genes (myogenin and myomirs (muscle-specific microRNAs)) and retain white fat characteristics such as Hoxc9 expression. Co-culture experiments verify that the UCP1-expressing cells...

  15. Premalignant lesions skew spleen cell responses to immune modulation by adipocytes.

    Science.gov (United States)

    Vielma, Silvana A; Klein, Richard L; Levingston, Corinne A; Young, M Rita I

    2013-05-01

    Obesity can promote a chronic inflammatory state and is associated with an increased risk for cancer. Since adipocytes can produce mediators that can regulate conventional immune cells, this study sought to determine if the presence of premalignant oral lesions would skew how immune cells respond to adipocyte-derived mediators to create an environment that may be more favorable for their progression toward cancer. While media conditioned by adipocytes stimulated normal spleen cell production of the T helper (Th) type-1 cytokines interleukin (IL)-2, interferon-γ (IFN-γ), IL-12 and granulocyte-monocyte colony-stimulating factor (GM CSF), media from premalignant lesion cells either blocked or had no added affect on the adipocyte-stimulated Th1 cytokine production. In contrast, media conditioned by premalignant lesion cells exacerbated adipocyte-stimulated spleen cell production of the Th2 cytokines IL-10 and IL-13, although it did not further enhance the adipocyte-stimulated spleen cell production of IL-4 and TGF-β. The premalignant lesion environment also heightened the adipocyte-stimulated spleen cell production of the inflammatory mediators IL 1α, IL-1β, IL-6 and IL-9, although it did not further increase the adipocyte-stimulated production of tumor necrosis factor-α (TNF-α). IL 17 production was unaffected by the adipocyte-derived mediators, but was synergistically triggered by adding media from premalignant lesion cells. These stimulatory effects on spleen cell production of Th2 and inflammatory mediators were not induced in the absence of media conditioned by adipocytes. In contrast, media conditioned by adipocytes did not stimulate production of predominantly monocyte-derived chemokine C-X-C motif ligand (CXCL)9, chemokine C-C motif ligand (CCL)3 or CCL4, although it stimulated production of CCL2 and the predominantly T cell-derived chemokine CCL5, which was the only chemokine whose production was further increased by media from premalignant lesions

  16. 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...... fibroblasts (MEFs) and white preadipocytes by expression of simian virus 40 large T antigen results in the expression of the brown fat-specific uncoupling protein 1 (UCP-1) in the adipose state. Retinoblastoma gene-deficient (Rb-/-) MEFs and stem cells, but not the corresponding wild-type cells, differentiate...

  17. Absence of Carbohydrate Response Element Binding Protein in Adipocytes Causes Systemic Insulin Resistance and Impairs Glucose Transport

    Directory of Open Access Journals (Sweden)

    Archana Vijayakumar

    2017-10-01

    Full Text Available Lower adipose-ChREBP and de novo lipogenesis (DNL are associated with insulin resistance in humans. Here, we generated adipose-specific ChREBP knockout (AdChREBP KO mice with negligible sucrose-induced DNL in adipose tissue (AT. Chow-fed AdChREBP KO mice are insulin resistant with impaired insulin action in the liver, muscle, and AT and increased AT inflammation. HFD-fed AdChREBP KO mice are also more insulin resistant than controls. Surprisingly, adipocytes lacking ChREBP display a cell-autonomous reduction in insulin-stimulated glucose transport that is mediated by impaired Glut4 translocation and exocytosis, not lower Glut4 levels. AdChREBP KO mice have lower levels of palmitic acid esters of hydroxy stearic acids (PAHSAs in serum, and AT. 9-PAHSA supplementation completely rescues their insulin resistance and AT inflammation. 9-PAHSA also normalizes impaired glucose transport and Glut4 exocytosis in ChREBP KO adipocytes. Thus, loss of adipose-ChREBP is sufficient to cause insulin resistance, potentially by regulating AT glucose transport and flux through specific lipogenic pathways.

  18. Cytosolic phosphoenolpyruvate carboxykinase is a response gene involved in porcine adipocyte adaptation to heat stress.

    Science.gov (United States)

    Qu, Huan; Ajuwon, Kolapo M

    2018-05-04

    Heat stress (HS) leads to increased lipid storage and expression of cytosolic phosphoenolpyruvate carboxykinase (PCK1) in pig adipocytes. However, the importance of PCK1 activation and lipid storage in the adaptive response to HS is unknown. Therefore, in vitro experiments were conducted to investigate the effect of PCK1 inhibition with 3-mercaptopicolinic acid (3MPA) on lipid storage and adipocyte response during HS. In vitro culture of adipocytes under HS (41.0 °C) increased (P cultured adipocytes were less able to induce adaptive responses such as upregulation of HSP70 and triglycerides, and this exacerbated ER stress during HS. Thus, PCK1 may function to alleviate ER stress that occurs during HS.

  19. 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 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...... in the regulation of white versus brown adipocyte differentiation in vitro and possibly in vivo. Here we summarize the current knowledge on the retinoblastoma protein in fat cells, with particular emphasis on its potential role in adipocyte lineage commitment and differentiation....

  20. Classical and alternative NF-κB signaling cooperate in regulating adipocyte differentiation and function

    DEFF Research Database (Denmark)

    Weidemann, A.; Lovas, A.; Rauch, A.

    2016-01-01

    Background and objective:Inflammation of adipose tissue (AT) is a central mediator of insulin resistance. However, the molecular mechanisms triggered by inflammatory cells are not fully understood. The aim of this study was to analyze the metabolic functions of lymphotoxin-β-receptor (LTβ...... to adipocytes. The molecular mechanism was elucidated by chromatin immunoprecipitation and combinatorial treatment with α-LTβR and tumor necrosis factor (TNF).Results:RelB FatKO mice showed improved insulin sensitivity despite increased adiposity and adipocyte hypertrophy. LTβR-induced activation of p52-Rel.......Conclusions:Our data describe an anti-adipogenic action of LTβR signaling and a novel synergism of alternative and classical NF-κB signaling in the regulation of adipocytes. In conclusion, this strong synergism between the two NF-κB pathways shows a method to inhibit adipocyte differentiation and to improve insulin...

  1. Bidirectional manipulation of gene expression in adipocytes using CRISPRa and siRNA

    DEFF Research Database (Denmark)

    Lundh, Morten; Pluciñska, Kaja; Isidor, Marie S

    2017-01-01

    OBJECTIVE: Functional investigation of novel gene/protein targets associated with adipocyte differentiation or function heavily relies on efficient and accessible tools to manipulate gene expression in adipocytes in vitro. Recent advances in gene-editing technologies such as CRISPR-Cas9 have...... not only eased gene editing but also greatly facilitated modulation of gene expression without altering the genome. Here, we aimed to develop and validate a competent in vitro adipocyte model of controllable functionality as well as multiplexed gene manipulation in adipocytes, using the CRISPRa "SAM......" system and siRNAs to simultaneously overexpress and silence selected genes in the same cell populations. METHODS: We introduced a stable expression of dCas9-VP64 and MS2-P65, the core components of the CRIPSRa SAM system, in mesenchymal C3H/10T1/2 cells through viral delivery and used guide RNAs...

  2. Amelioration of Mitochondrial Dysfunction-Induced Insulin Resistance in Differentiated 3T3-L1 Adipocytes via Inhibition of NF-κB Pathways

    Directory of Open Access Journals (Sweden)

    Mohamad Hafizi Abu Bakar

    2014-12-01

    Full Text Available A growing body of evidence suggests that activation of nuclear factor kappa B (NF-κB signaling pathways is among the inflammatory mechanism involved in the development of insulin resistance and chronic low-grade inflammation in adipose tissues derived from obese animal and human subjects. Nevertheless, little is known about the roles of NF-κB pathways in regulating mitochondrial function of the adipose tissues. In the present study, we sought to investigate the direct effects of celastrol (potent NF-κB inhibitor upon mitochondrial dysfunction-induced insulin resistance in 3T3-L1 adipocytes. Celastrol ameliorates mitochondrial dysfunction by altering mitochondrial fusion and fission in adipocytes. The levels of oxidative DNA damage, protein carbonylation and lipid peroxidation were down-regulated. Further, the morphology and quantification of intracellular lipid droplets revealed the decrease of intracellular lipid accumulation with reduced lipolysis. Moreover, massive production of the pro-inflammatory mediators tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β were markedly depleted. Insulin-stimulated glucose uptake activity was restored with the enhancement of insulin signaling pathways. This study signified that the treatments modulated towards knockdown of NF-κB transcription factor may counteract these metabolic insults exacerbated in our model of synergy between mitochondrial dysfunction and inflammation. These results demonstrate for the first time that NF-κB inhibition modulates mitochondrial dysfunction induced insulin resistance in 3T3-L1 adipocytes.

  3. Prolonged inorganic arsenite exposure suppresses insulin-stimulated AKT S473 phosphorylation and glucose uptake in 3T3-L1 adipocytes: involvement of the adaptive antioxidant response.

    Science.gov (United States)

    Xue, Peng; Hou, Yongyong; Zhang, Qiang; Woods, Courtney G; Yarborough, Kathy; Liu, Huiyu; Sun, Guifan; Andersen, Melvin E; Pi, Jingbo

    2011-04-08

    There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of type 2 diabetes (T2D). One critical feature of T2D is insulin resistance in peripheral tissues, especially in mature adipocytes, the hallmark of which is decreased insulin-stimulated glucose uptake (ISGU). Despite the deleterious effects of reactive oxygen species (ROS), they have been recognized as a second messenger serving an intracellular signaling role for insulin action. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central transcription factor regulating cellular adaptive response to oxidative stress. This study proposes that in response to arsenic exposure, the NRF2-mediated adaptive induction of endogenous antioxidant enzymes blunts insulin-stimulated ROS signaling and thus impairs ISGU. Exposure of differentiated 3T3-L1 cells to low-level (up to 2 μM) inorganic arsenite (iAs³(+)) led to decreased ISGU in a dose- and time-dependent manner. Concomitant to the impairment of ISGU, iAs³(+) exposure significantly attenuated insulin-stimulated intracellular ROS accumulation and AKT S473 phosphorylation, which could be attributed to the activation of NRF2 and induction of a battery of endogenous antioxidant enzymes. In addition, prolonged iAs³(+) exposure of 3T3-L1 adipocytes resulted in significant induction of inflammatory response genes and decreased expression of adipogenic genes and glucose transporter type 4 (GLUT4), suggesting chronic inflammation and reduction in GLUT4 expression may also be involved in arsenic-induced insulin resistance in adipocytes. Taken together our studies suggest that prolonged low-level iAs³(+) exposure activates the cellular adaptive oxidative stress response, which impairs insulin-stimulated ROS signaling that is involved in ISGU, and thus causes insulin resistance in adipocytes. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Chondroitin Sulfate Inhibits Monocyte Chemoattractant Protein-1 Release From 3T3-L1 Adipocytes: A New Treatment Opportunity for Obesity-Related Inflammation?

    Directory of Open Access Journals (Sweden)

    Thomas V Stabler

    2017-08-01

    Full Text Available Monocyte chemoattractant protein-1 (MCP-1 overproduction from inflamed adipose tissue is a major contributor to obesity-related metabolic syndromes. 3T3-L1 embryonic fibroblasts were cultured and differentiated into adipocytes using an established protocol. Adipocytes were treated with lipopolysaccharide (LPS to induce inflammation and thus MCP-1 release. At the same time, varying concentrations of chondroitin sulfate (CS were added in a physiologically relevant range (10-200 µg/mL to determine its impact on MCP-1 release. Chondroitin sulfate, a natural glycosaminoglycan of connective tissue including the cartilage extracellular matrix, was chosen on the basis of our previous studies demonstrating its anti-inflammatory effect on macrophages. Because the main action of MCP-1 is to induce monocyte migration, cultured THP-1 monocytes were used to test whether CS at the highest physiologically relevant concentration could inhibit cell migration induced by human recombinant MCP-1. Chondroitin sulfate (100-200 µg/mL inhibited MCP-1 release from inflamed adipocytes in a dose-dependent manner ( P  < .01, 95% confidence interval [CI]: −5.89 to −3.858 at 100 µg/mL and P  < .001, 95% CI: −6.028 to −3.996 at 200 µg/mL but had no effect on MCP-1–driven chemotaxis of THP-1 monocytes. In summary, CS could be expected to reduce macrophage infiltration into adipose tissue by reduction in adipocyte expression and release of MCP-1 and as such might reduce adipose tissue inflammation in response to pro-inflammatory stimuli such as LPS, now increasingly recognized to be relevant in vivo.

  5. Selective inhibition of B lymphocytes in TBTC-treated human bone marrow long-term culture.

    NARCIS (Netherlands)

    Carfi', M.; Bowe, G.; Pieters, R.; Gribaldo, L.

    2010-01-01

    Tributyltin chloride (TBTC) is well known for its immunotoxic effect, in particular towards immature thymocytes. TBTC is also known to induce adipocyte differentiation in primary human bone marrow cultures, which is reflected in the decrease in a number of adipocyte-derived cytokines, chemokines and

  6. High-dose Resveratrol Inhibits Insulin Signaling Pathway in 3T3-L1 Adipocytes

    OpenAIRE

    Lee, Haemi; Kim, Jae-woo

    2013-01-01

    Background Insulin resistance is a major factor in the development of metabolic syndrome and is associated with central obesity and glucose intolerance. Resveratrol, a polyphenol found in fruits, has been shown to improve metabolic conditions. Although it has been widely studied how resveratrol affects metabolism, little is known about how resveratrol regulates lipogenesis with insulin signaling in 3T3-L1 adipocytes. Methods: We treated differentiated 3T3-L1 adipocytes with resveratrol to obs...

  7. Family history of type 2 diabetes, abdominal adipocyte size and markers of the metabolic syndrome.

    Science.gov (United States)

    Anthanont, P; Ramos, P; Jensen, M D; Hames, K C

    2017-11-01

    A major risk factor of type 2 diabetes mellitus (T2DM) is a positive family history of diabetes. First degree relatives (FDR) of patients with T2DM are more insulin resistant and are reported to have larger abdominal subcutaneous adipocytes than adults without a family history. Our objectives were to assess whether FDR of T2DM are associated with larger abdominal adipocytes independent of age, sex and abdominal subcutaneous fat and to assess whether a family history of T2DM is also independently related to femoral adipocyte size, as well as visceral fat and fasting plasma triglyceride (TG) concentrations. We extracted adipocyte size, body composition, plasma TG and demographic data of non-diabetic research participants of previous studies conducted in our laboratory. We ascertained the family history of T2DM from the electronic medical records. Multivariate regression analysis was used to assess whether FDR of T2DM are more likely to have other risk factors after adjusting for known covariates. Of 604 participants, 148 were FDR of T2DM. Although abdominal and femoral adipocyte size was greater in FDR of T2DM than those without a family history (0.74±0.33 vs 0.63±0.33 μg lipid per cell, Phistory of T2DM was a significant predictor of abdominal adipocyte size after adjustment for age and body fat distribution parameters in females (total R 2 =0.5, Phistory of T2DM was not independently predictive of femoral adipocyte size, visceral fat area or TG. Female FDR of T2DM have larger abdominal, but not femoral, adipocytes, even after accounting for age and body fat distribution.

  8. ATF3 inhibits adipocyte differentiation of 3T3-L1 cells

    International Nuclear Information System (INIS)

    Jang, Min Kyung; Kim, Cho Hee; Seong, Je Kyung; Jung, Myeong Ho

    2012-01-01

    Highlights: ► Overexpression of ATF3 inhibits adipocyte differentiation in 3T3-L1 cells. ► Overexpression of ATF3 represses C/EBPα expression. ► ATF3 directly binds to mouse C/EBPα promoter spanning from −1928 to −1907. ► ATF3 may play a role in hypoxia-mediated inhibition of adipocyte differentiation. -- Abstract: ATF3 is a stress-adaptive gene that regulates proliferation or apoptosis under stress conditions. However, the role of ATF3 is unknown in adipocyte cells. Therefore, in this study, we investigated the functional role of ATF3 in adipocytes. Both lentivirus-mediated overexpression of ATF3 and stably-overexpressed ATF3 inhibited adipocyte differentiation in 3T3-L1 cells, as revealed by decreased lipid staining with oil red staining and reduction in adipogenic genes. Thapsigargin treatment and overexpression of ATF3 decreased C/EBPα transcript and repressed the activity of the 3.6-kb mouse C/EBPα promoter, demonstrating that ATF3 downregulates C/EBPα expression. Transfection studies using mutant constructs containing 5′-deletions in the C/EBPα promoter revealed that a putative ATF/CRE element, GGATGTCA, is located between −1921 and −1914. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that ATF3 directly binds to mouse C/EBPα promoter spanning from −1928 to −1907. Both chemical hypoxia-mimetics or physical hypoxia led to reduce the C/EBPα mRNA and repress the promoter activity of the C/EBPα gene, whereas increase ATF3 mRNA, suggesting that ATF3 may contribute to the inhibition of adipocyte differentiation in hypoxia through downregulation of C/EBPα expression. Collectively, these results demonstrate that ATF3 represses the C/EBPα gene, resulting in inhibition of adipocyte differentiation, and thus plays a role in hypoxia-mediated inhibition of adipocyte differentiation.

  9. Lipid droplet analysis in caveolin-deficient adipocytes: alterations in surface phospholipid composition and maturation defects

    OpenAIRE

    Blouin, Cedric M.; Le Lay, Soazig; Eberl, Anita; Koefeler, Harald C.; Guerrera, Ida Chiara; Klein, Christophe; Le Liepvre, Xavier; Lasnier, Francoise; Bourron, Olivier; Gautier, Jean-Francois; Ferre, Pascal; Hajduch, Eric; Dugail, Isabelle

    2010-01-01

    Caveolins form plasmalemnal invaginated caveolae. They also locate around intracellular lipid droplets but their role in this location remains unclear. By studying primary adipocytes that highly express caveolin-1, we characterized the impact of caveolin-1 deficiency on lipid droplet proteome and lipidome. We identified several missing proteins on the lipid droplet surface of caveolin-deficient adipocytes and showed that the caveolin-1 lipid droplet pool is organized as multi-protein complexe...

  10. Highly efficient differentiation of embryonic stem cells into adipocytes by ascorbic acid

    OpenAIRE

    Ixchelt Cuaranta-Monroy; Zoltan Simandi; Zsuzsanna Kolostyak; Quang-Minh Doan-Xuan; Szilard Poliska; Attila Horvath; Gergely Nagy; Zsolt Bacso; Laszlo Nagy

    2014-01-01

    Adipocyte differentiation and function have become the major research targets due to the increasing interest in obesity and related metabolic conditions. Although, late stages of adipogenesis have been extensively studied, the early phases remain poorly understood. Here we present that supplementing ascorbic acid (AsA) to the adipogenic differentiation cocktail enables the robust and efficient differentiation of mouse embryonic stem cells (mESCs) to mature adipocytes. Such ESC-derived adipocy...

  11. E4orf1 induction in adipose tissue promotes insulin-independent signaling in the adipocyte

    Directory of Open Access Journals (Sweden)

    Christine M. Kusminski

    2015-10-01

    Conclusion: We conclude that E4orf1 expression in the adipocyte leads to enhanced baseline activation of the distal insulin signaling node, yet impaired insulin receptor stimulation in the presence of insulin, with important implications for the regulation of adiponectin secretion. The resulting systemic phenotype is complex, yet highlights the powerful nature of manipulating selective branches of the insulin signaling network within the adipocyte.

  12. DGAT enzymes are required for triacylglycerol synthesis and lipid droplets in adipocytes.

    Science.gov (United States)

    Harris, Charles A; Haas, Joel T; Streeper, Ryan S; Stone, Scot J; Kumari, Manju; Yang, Kui; Han, Xianlin; Brownell, Nicholas; Gross, Richard W; Zechner, Rudolf; Farese, Robert V

    2011-04-01

    The total contribution of the acyl CoA:diacylglycerol acyltransferase (DGAT) enzymes, DGAT1 and DGAT2, to mammalian triacylglycerol (TG) synthesis has not been determined. Similarly, whether DGAT enzymes are required for lipid droplet (LD) formation is unknown. In this study, we examined the requirement for DGAT enzymes in TG synthesis and LDs in differentiated adipocytes with genetic deletions of DGAT1 and DGAT2. Adipocytes with a single deletion of either enzyme were capable of TG synthesis and LD formation. In contrast, adipocytes with deletions of both DGATs were severely lacking in TG and did not have LDs, indicating that DGAT1 and DGAT2 account for nearly all TG synthesis in adipocytes and appear to be required for LD formation during adipogenesis. DGAT enzymes were not absolutely required for LD formation in mammalian cells, however; macrophages deficient in both DGAT enzymes were able to form LDs when incubated with cholesterol-rich lipoproteins. Although adipocytes lacking both DGATs had no TG or LDs, they were fully differentiated by multiple criteria. Our findings show that DGAT1 and DGAT2 account for the vast majority of TG synthesis in mice, and DGAT function is required for LDs in adipocytes, but not in all cell types.

  13. DGAT enzymes are required for triacylglycerol synthesis and lipid droplets in adipocytes[S

    Science.gov (United States)

    Harris, Charles A.; Haas, Joel T.; Streeper, Ryan S.; Stone, Scot J.; Kumari, Manju; Yang, Kui; Han, Xianlin; Brownell, Nicholas; Gross, Richard W.; Zechner, Rudolf; Farese, Robert V.

    2011-01-01

    The total contribution of the acyl CoA:diacylglycerol acyltransferase (DGAT) enzymes, DGAT1 and DGAT2, to mammalian triacylglycerol (TG) synthesis has not been determined. Similarly, whether DGAT enzymes are required for lipid droplet (LD) formation is unknown. In this study, we examined the requirement for DGAT enzymes in TG synthesis and LDs in differentiated adipocytes with genetic deletions of DGAT1 and DGAT2. Adipocytes with a single deletion of either enzyme were capable of TG synthesis and LD formation. In contrast, adipocytes with deletions of both DGATs were severely lacking in TG and did not have LDs, indicating that DGAT1 and DGAT2 account for nearly all TG synthesis in adipocytes and appear to be required for LD formation during adipogenesis. DGAT enzymes were not absolutely required for LD formation in mammalian cells, however; macrophages deficient in both DGAT enzymes were able to form LDs when incubated with cholesterol-rich lipoproteins. Although adipocytes lacking both DGATs had no TG or LDs, they were fully differentiated by multiple criteria. Our findings show that DGAT1 and DGAT2 account for the vast majority of TG synthesis in mice, and DGAT function is required for LDs in adipocytes, but not in all cell types. PMID:21317108

  14. 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.

  15. Oligopeptide complex for targeted non-viral gene delivery to adipocytes

    Science.gov (United States)

    Won, Young-Wook; Adhikary, Partho Protim; Lim, Kwang Suk; Kim, Hyung Jin; Kim, Jang Kyoung; Kim, Yong-Hee

    2014-12-01

    Commercial anti-obesity drugs acting in the gastrointestinal tract or the central nervous system have been shown to have limited efficacy and severe side effects. Anti-obesity drug development is thus focusing on targeting adipocytes that store excess fat. Here, we show that an adipocyte-targeting fusion-oligopeptide gene carrier consisting of an adipocyte-targeting sequence and 9-arginine (ATS-9R) selectively transfects mature adipocytes by binding to prohibitin. Injection of ATS-9R into obese mice confirmed specific binding of ATS-9R to fat vasculature, internalization and gene expression in adipocytes. We also constructed a short-hairpin RNA (shRNA) for silencing fatty-acid-binding protein 4 (shFABP4), a key lipid chaperone in fatty-acid uptake and lipid storage in adipocytes. Treatment of obese mice with ATS-9R/shFABP4 led to metabolic recovery and body-weight reduction (>20%). The ATS-9R/shFABP4 oligopeptide complex could prove to be a safe therapeutic approach to regress and treat obesity as well as obesity-induced metabolic syndromes.

  16. Bone marrow adipocytes promote the regeneration of stem cells and hematopoiesis by secreting SCF

    Science.gov (United States)

    Zhou, Bo O.; Yu, Hua; Yue, Rui; Zhao, Zhiyu; Rios, Jonathan J.; Naveiras, Olaia; Morrison, Sean J.

    2017-01-01

    Endothelial cells and Leptin Receptor+ (LepR+) stromal cells are critical sources of haematopoietic stem cell (HSC) niche factors, including Stem Cell Factor (SCF), in bone marrow. After irradiation or chemotherapy, these cells are depleted while adipocytes become abundant. We discovered that bone marrow adipocytes synthesize SCF. They arise from Adipoq-Cre/ER+ progenitors, which represent ~5% of LepR+ cells, and proliferate after irradiation. Scf deletion using Adipoq-Cre/ER inhibited hematopoietic regeneration after irradiation or 5-fluorouracil treatment, depleting HSCs and reducing mouse survival. Scf from LepR+ cells, but not endothelial, hematopoietic, or osteoblastic cells, also promoted regeneration. In non-irradiated mice, Scf deletion using Adipoq-Cre/ER did not affect HSC frequency in long bones, which have few adipocytes, but depleted HSCs in tail vertebrae, which have abundant adipocytes. A-ZIP/F1 ‘fatless” mice exhibited delayed hematopoietic regeneration in long bones but not in tail vertebrae, where adipocytes inhibited vascularization. Adipocytes are a niche component that promotes hematopoietic regeneration. PMID:28714970

  17. Bone marrow adipocytes promote the regeneration of stem cells and haematopoiesis by secreting SCF.

    Science.gov (United States)

    Zhou, Bo O; Yu, Hua; Yue, Rui; Zhao, Zhiyu; Rios, Jonathan J; Naveiras, Olaia; Morrison, Sean J

    2017-08-01

    Endothelial cells and leptin receptor + (LepR + ) stromal cells are critical sources of haematopoietic stem cell (HSC) niche factors, including stem cell factor (SCF), in bone marrow. After irradiation or chemotherapy, these cells are depleted while adipocytes become abundant. We discovered that bone marrow adipocytes synthesize SCF. They arise from Adipoq-Cre/ER + progenitors, which represent ∼5% of LepR + cells, and proliferate after irradiation. Scf deletion using Adipoq-Cre/ER inhibited haematopoietic regeneration after irradiation or 5-fluorouracil treatment, depleting HSCs and reducing mouse survival. Scf from LepR + cells, but not endothelial, haematopoietic or osteoblastic cells, also promoted regeneration. In non-irradiated mice, Scf deletion using Adipoq-Cre/ER did not affect HSC frequency in long bones, which have few adipocytes, but depleted HSCs in tail vertebrae, which have abundant adipocytes. A-ZIP/F1 'fatless' mice exhibited delayed haematopoietic regeneration in long bones but not in tail vertebrae, where adipocytes inhibited vascularization. Adipocytes are a niche component that promotes haematopoietic regeneration.

  18. Lipid droplets fusion in adipocyte differentiated 3T3-L1 cells: A Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Boschi, Federico, E-mail: federico.boschi@univr.it [Department of Neurological and Movement Sciences, University of Verona, Strada Le Grazie 8, 37134 Verona (Italy); Department of Computer Science, University of Verona, Strada Le Grazie 15, 37134 Verona (Italy); Rizzatti, Vanni; Zamboni, Mauro [Department of Medicine, Geriatric Section, University of Verona, Piazzale Stefani 1, 37126 Verona (Italy); Sbarbati, Andrea [Department of Neurological and Movement Sciences, University of Verona, Strada Le Grazie 8, 37134 Verona (Italy)

    2014-02-15

    Several human worldwide diseases like obesity, type 2 diabetes, hepatic steatosis, atherosclerosis and other metabolic pathologies are related to the excessive accumulation of lipids in cells. Lipids accumulate in spherical cellular inclusions called lipid droplets (LDs) whose sizes range from fraction to one hundred of micrometers in adipocytes. It has been suggested that LDs can grow in size due to a fusion process by which a larger LD is obtained with spherical shape and volume equal to the sum of the progenitors’ ones. In this study, the size distribution of two populations of LDs was analyzed in immature and mature (5-days differentiated) 3T3-L1 adipocytes (first and second populations, respectively) after Oil Red O staining. A Monte Carlo simulation of interaction between LDs has been developed in order to quantify the size distribution and the number of fusion events needed to obtain the distribution of the second population size starting from the first one. Four models are presented here based on different kinds of interaction: a surface weighted interaction (R2 Model), a volume weighted interaction (R3 Model), a random interaction (Random model) and an interaction related to the place where the LDs are born (Nearest Model). The last two models mimic quite well the behavior found in the experimental data. This work represents a first step in developing numerical simulations of the LDs growth process. Due to the complex phenomena involving LDs (absorption, growth through additional neutral lipid deposition in existing droplets, de novo formation and catabolism) the study focuses on the fusion process. The results suggest that, to obtain the observed size distribution, a number of fusion events comparable with the number of LDs themselves is needed. Moreover the MC approach results a powerful tool for investigating the LDs growth process. Highlights: • We evaluated the role of the fusion process in the synthesis of the lipid droplets. • We compared the

  19. Lipid droplets fusion in adipocyte differentiated 3T3-L1 cells: A Monte Carlo simulation

    International Nuclear Information System (INIS)

    Boschi, Federico; Rizzatti, Vanni; Zamboni, Mauro; Sbarbati, Andrea

    2014-01-01

    Several human worldwide diseases like obesity, type 2 diabetes, hepatic steatosis, atherosclerosis and other metabolic pathologies are related to the excessive accumulation of lipids in cells. Lipids accumulate in spherical cellular inclusions called lipid droplets (LDs) whose sizes range from fraction to one hundred of micrometers in adipocytes. It has been suggested that LDs can grow in size due to a fusion process by which a larger LD is obtained with spherical shape and volume equal to the sum of the progenitors’ ones. In this study, the size distribution of two populations of LDs was analyzed in immature and mature (5-days differentiated) 3T3-L1 adipocytes (first and second populations, respectively) after Oil Red O staining. A Monte Carlo simulation of interaction between LDs has been developed in order to quantify the size distribution and the number of fusion events needed to obtain the distribution of the second population size starting from the first one. Four models are presented here based on different kinds of interaction: a surface weighted interaction (R2 Model), a volume weighted interaction (R3 Model), a random interaction (Random model) and an interaction related to the place where the LDs are born (Nearest Model). The last two models mimic quite well the behavior found in the experimental data. This work represents a first step in developing numerical simulations of the LDs growth process. Due to the complex phenomena involving LDs (absorption, growth through additional neutral lipid deposition in existing droplets, de novo formation and catabolism) the study focuses on the fusion process. The results suggest that, to obtain the observed size distribution, a number of fusion events comparable with the number of LDs themselves is needed. Moreover the MC approach results a powerful tool for investigating the LDs growth process. Highlights: • We evaluated the role of the fusion process in the synthesis of the lipid droplets. • We compared the

  20. Novel pathway of adipogenesis through cross-talk between adipose tissue macrophages, adipose stem cells and adipocytes: evidence of cell plasticity.

    Directory of Open Access Journals (Sweden)

    Gregorio Chazenbalk

    Full Text Available INTRODUCTION: Previous studies highlight a complex relationship between lineage and phenotype for adipose tissue macrophages (ATMs, adipose stem cells (ASCs, and adipocytes, suggesting a high degree of plasticity of these cells. In the present study, using a novel co-culture system, we further characterized the interaction between ATMs, ASCs and adipocytes. RESEARCH DESIGN AND METHODS: Human adipocytes and the stromal vascular fraction containing ATMs and ASCs were isolated from human adipose tissue and co-cultured for 24 hours. FACS was used to characterize ATMs and ASCs before and after co-culture. Preadipocytes generated after co-culture were characterized by immunostaining for DLK (preadipocytes, CD14 and CD68 (ATMs, CD34 (ASCs, and Nile Red staining for lipid drops. qRT-PCR was used to quantify adipogenic markers such as C/EBPα and PPARγ. A novel fluorescent nanobead lineage tracing method was utilized before co-culture where fluorescent nanobeads were internalized by CD68 (+ ATMs. RESULTS: Co-culture of adipocytes with ATMs and ASCs increased the formation of new preadipocytes, thereby increasing lipid accumulation and C/EBPα and PPARγ gene expression. Preadipocytes originating after co-culture were positive for markers of preadipocytes, ATMs and ASCs. Moreover, fluorescent nanobeads were internalized by ATMs before co-culture and the new preadipocytes formed after co-culture also contained fluorescent nanobeads, suggesting that new preadipocytes originated in part from ATMs. The formation of CD34(+/CD68(+/DLK (+ cell spheres supported the interaction of ATMs, ASCs and preadipocytes. CONCLUSIONS: Cross-talk between adipocytes, ATMs and ASCs promotes preadipocyte formation. The regulation of this novel adipogenic pathway involves differentiation of ATMs to preadipocytes. The presence of CD34(+/CD68(+/DLK(+ cells grouped in spheres suggest that paracrine interactions between these cell types plays an important role in the generation and

  1. FUS-DDIT3 prevents the development of adipocytic precursors in liposarcoma by repressing PPARgamma and C/EBPalpha and activating eIF4E.

    Directory of Open Access Journals (Sweden)

    Pedro A Pérez-Mancera

    Full Text Available BACKGROUND: FUS-DDIT3 is a chimeric protein generated by the most common chromosomal translocation t(12;16(q13;p11 linked to liposarcomas, which are characterized by the accumulation of early adipocytic precursors. Current studies indicate that FUS-DDIT3- liposarcoma develops from uncommitted progenitors. However, the precise mechanism whereby FUS-DDIT3 contributes to the differentiation arrest remains to be elucidated. METHODOLOGY/PRINCIPAL FINDINGS: Here we have characterized the adipocyte regulatory protein network in liposarcomas of FUS-DITT3 transgenic mice and showed that PPARgamma2 and C/EBPalpha expression was altered. Consistent with in vivo data, FUS-DDIT3 MEFs and human liposarcoma cell lines showed a similar downregulation of both PPARgamma2 and C/EBPalpha expression. Complementation studies with PPARgamma but not C/EBPalpha rescued the differentiation block in committed adipocytic precursors expressing FUS-DDIT3. Our results further show that FUS-DDIT3 interferes with the control of initiation of translation by upregulation of the eukaryotic translation initiation factors eIF2 and eIF4E both in FUS-DDIT3 mice and human liposarcomas cell lines, explaining the shift towards the truncated p30 isoform of C/EBPalpha in liposarcomas. Suppression of the FUS-DDIT3 transgene did rescue this adipocyte differentiation block. Moreover, eIF4E was also strongly upregulated in normal adipose tissue of FUS-DDIT3 transgenic mice, suggesting that overexpression of eIF4E may be a primary event in the initiation of liposarcomas. Reporter assays showed FUS-DDIT3 is involved in the upregulation of eIF4E in liposarcomas and that both domains of the fusion protein are required for affecting eIF4E expression. CONCLUSIONS/SIGNIFICANCE: Taken together, this study provides evidence of the molecular mechanisms involve in the disruption of normal adipocyte differentiation program in liposarcoma harbouring the chimeric gene FUS-DDIT3.

  2. Differentiation of the insulin-sensitive glucose transporter in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Frost, S.C.; Baly, D.L.; Cushman, S.W.; Lane, M.D.; Simpson, I.A.

    1986-01-01

    3T3-L1 fibroblasts differentiate in culture to resemble adipocytes both morphologically and biochemically. Insulin-sensitive glucose transport, as measured by 2-deoxy-[1- 14 C]- glucose uptake in the undifferentiated cell is small (2X). In contrast, the rate of glucose transport in fully differentiated cells is elevated 15-fold over basal in the presence of insulin. To determine if this is due to an increase in the number of transporters/cell or accessibility to the transporters, the number of transporters was measured in subcellular fractions over differentiation using a 3 H-cytochalasin B binding assay. The increase in the rate of insulin-sensitive glucose transport directly parallels an increase in the number of transporters which reside in an insulin-responsive intracellular compartment. This observation was confirmed by identifying the transporters by immunoblotting using an antibody generated against the human erythrocyte transporter. The molecular weight of this transporter increases over differentiation from a single band of 40kDa to a heterogeneous triplet of 40, 44 and 48kDa. These data suggest that the transporter undergoes differential processing and that the functional, insulin-responsive transporter may be different from the insulin-insensitive (basal) transporter

  3. Prenatal Exposure to the Environmental Obesogen Tributyltin Predisposes Multipotent Stem Cells to Become Adipocytes

    Science.gov (United States)

    Kirchner, Séverine; Kieu, Tiffany; Chow, Connie; Casey, Stephanie; Blumberg, Bruce

    2010-01-01

    The environmental obesogen hypothesis proposes that pre- and postnatal exposure to environmental chemicals contributes to adipogenesis and the development of obesity. Tributyltin (TBT) is an agonist of both retinoid X receptor (RXR) and peroxisome proliferator-activated receptor γ (PPARγ). Activation of these receptors can elevate adipose mass in adult mice exposed to the chemical in utero. Here we show that TBT sensitizes human and mouse multipotent stromal stem cells derived from white adipose tissue [adipose-derived stromal stem cells (ADSCs)] to undergo adipogenesis. In vitro exposure to TBT, or the PPARγ activator rosiglitazone increases adipogenesis, cellular lipid content, and expression of adipogenic genes. The adipogenic effects of TBT and rosiglitazone were blocked by the addition of PPARγ antagonists, suggesting that activation of PPARγ mediates the effect of both compounds on adipogenesis. ADSCs from mice exposed to TBT in utero showed increased adipogenic capacity and reduced osteogenic capacity with enhanced lipid accumulation in response to adipogenic induction. ADSCs retrieved from animals exposed to TBT in utero showed increased expression of PPARγ target genes such as the early adipogenic differentiation gene marker fatty acid-binding protein 4 and hypomethylation of the promoter/enhancer region of the fatty acid-binding protein 4 locus. Hence, TBT alters the stem cell compartment by sensitizing multipotent stromal stem cells to differentiate into adipocytes, an effect that could likely increase adipose mass over time. PMID:20160124

  4. The relationship of omental and subcutaneous adipocyte size to metabolic disease in severe obesity.

    LENUS (Irish Health Repository)

    O'Connell, Jean

    2012-02-01

    OBJECTIVE: Several studies have reported the existence of a subgroup of obese individuals with normal metabolic profiles. It remains unclear what factors are responsible for this phenomenon. We proposed that adipocyte size might be a key factor in the protection of metabolically healthy obese (MHO) individuals from the adverse effects of obesity. SUBJECTS: Thirty-five patients undergoing bariatric surgery were classified as MHO (n = 15) or metabolically unhealthy obese (MUO, n = 20) according to cut-off points adapted from the International Diabetes Federation definition of the metabolic syndrome. Median body mass index (BMI) was 48 (range 40-71). RESULTS: There was a moderate correlation between omental adipocyte size and subcutaneous adipocyte size (r = 0.59, p<0.05). The MHO group had significantly lower mean omental adipocyte size (80.9+\\/-10.9 microm) when compared with metabolically unhealthy patients (100.0+\\/-7.6 microm, p<0.0001). Mean subcutaneous adipocyte size was similar between the two groups (104.1+\\/-8.5 microm versus 107.9+\\/-7.1 microm). Omental, but not subcutaneous adipocyte size, correlated with the degree of insulin resistance as measured by HOMA-IR (r = 0.73, p<0.0005), as well as other metabolic parameters including triglyceride\\/HDL-cholesterol ratio and HbA1c. Twenty-eight patients consented to liver biopsy. Of these, 46% had steatohepatitis and fibrosis. Fifty percent (including all the MHO patients) had steatosis only. Both omental and subcutaneous adipocyte size were significantly associated with the degree of steatosis (r = 0.66, p<0.0001 and r = 0.63, p<0.005 respectively). However, only omental adipocyte size was an independent predictor of the presence or absence of fibrosis. CONCLUSION: Metabolically healthy individuals are a distinct subgroup of the severely obese. Both subcutaneous and omental adipocyte size correlated positively with the degree of fatty liver, but only omental adipocyte size was related to metabolic health

  5. A proteomic approach for identification of secreted proteins during the differentiation of 3T3-L1 preadipocytes to adipocytes

    DEFF Research Database (Denmark)

    Kratchmarova, Irina; Kalume, Dario E; Blagoev, Blagoy

    2002-01-01

    molecules that have not been shown previously to be expressed differentially during the process of adipogenesis. Pigment epithelium-derived factor, a soluble molecule with potent antiangiogenic properties, was found to be highly secreted by preadipocytes but not adipocytes. Conversely, we found hippocampal...... cholinergic neurostimulating peptide, neutrophil gelatinase-associated lipocalin, and haptoglobin to be expressed highly by mature adipocytes. We also used liquid chromatography-based separation followed by automated tandem mass spectrometry to identify proteins secreted by mature adipocytes. Several...

  6. Experimental Model to Study the Role of Retinoblastoma Gene Product (pRb) for Determination of Adipocyte Differentiation.

    Science.gov (United States)

    Popov, B V; Shilo, P S; Zhidkova, O V; Zaichik, A M; Petrov, N S

    2015-06-01

    Using stable constitutive expression of retinoblastoma gene product (pRb) in polypotent mesenchymal 10T1/2 cells we obtained stable cell lines hyperexpressing functionally active or inactive mutant pRb. The cells producing active exogenous pRb demonstrated high sensitivity to adipocyte differentiation inductors, whereas production of inactive form of the exogenous protein suppressed adipocyte differentiation. The obtained lines can serve as the experimental model for studying the role of pRb in determination of adipocyte differentiation.

  7. Gender Differences in Adipocyte Metabolism and Liver Cancer Progression

    Directory of Open Access Journals (Sweden)

    Otto Ka-Wing Cheung

    2016-09-01

    Full Text Available Liver cancer is the third most common cancer type and the second leading cause of deaths in men. Large population studies have demonstrated remarkable gender disparities in the incidence and the cumulative risk of liver cancer. A number of emerging risk factors regarding metabolic alterations associated with obesity, diabetes and dyslipidemia have been ascribed to the progression of non-alcoholic fatty liver diseases (NAFLD and ultimately liver cancer. The deregulation of fat metabolism derived from excessive insulin, glucose and lipid promotes cancer-causing inflammatory signaling and oxidative stress, which eventually triggers the uncontrolled hepatocellular proliferation. This review presents the current standing on the gender differences in body fat compositions and their mechanistic linkage with the development of NAFLD-related liver cancer, with an emphasis on genetic, epigenetic and microRNA control. The potential roles of sex hormones in instructing adipocyte metabolic programs may help unravel the mechanisms underlying gender dimorphism in liver cancer and identify the metabolic targets for disease management.

  8. Lipolytic actions of secretin in mouse adipocytes[S

    Science.gov (United States)

    Sekar, Revathi; Chow, Billy K. C.

    2014-01-01

    Secretin (Sct), a classical gut hormone, is now known to play pleiotropic functions in the body including osmoregulation, digestion, and feeding control. As Sct has long been implicated to regulate metabolism, in this report, we have investigated a potential lipolytic action of Sct. In our preliminary studies, both Sct levels in circulation and Sct receptor (SctR) transcripts in adipose tissue were upregulated during fasting, suggesting a potential physiological relevance of Sct in regulating lipolysis. Using SctR knockout and Sct knockout mice as controls, we show that Sct is able to stimulate lipolysis in vitro in isolated adipocytes dose- and time-dependently, as well as acute lipolysis in vivo. H-89, a protein kinase A (PKA) inhibitor, was found to attenuate lipolytic effects of 1 μM Sct in vitro, while a significant increase in PKA activity upon Sct injection was observed in the adipose tissue in vivo. Sct was also found to stimulate phosphorylation at 660ser of hormone sensitive lipase (HSL) and to bring about the translocation of HSL from cytosol to the lipid droplet. In summary, our data demonstrate for the first time the in vivo and in vitro lipolytic effects of Sct, and that this function is mediated by PKA and HSL. PMID:24273196

  9. Monoterpene limonene induces brown fat-like phenotype in 3T3-L1 white adipocytes.

    Science.gov (United States)

    Lone, Jameel; Yun, Jong Won

    2016-05-15

    Several dietary compounds that are able to induce the brown fat-like phenotype in white adipocytes have been considered for treatment of obesity due to their ability to increase energy expenditure. Here, we report that limonene induces the brown fat-like phenotype in 3T3-L1 adipocytes by increasing expression of brown adipocyte-specific genes and proteins. Limonene-induced browning in white adipocytes was investigated by determining expression levels of brown fat-specific genes and proteins by real-time RT-PCR, immunoblot analysis, and immunocytochemical staining. Limonene enhanced mitochondrial biogenesis, as evidenced by increased mitochondrial content and immunofluorescent intensity. Limonene also significantly elevated protein levels of HSL, PLIN, p-AMPK, p-ACC, ACO, COX4, CPT1, and CYT C, suggesting its possible role in enhancement of lipolysis and lipid catabolism. Increased expression of PRDM16, UCP1, C/EBPβ, and other brown fat-specific markers by limonene was possibly mediated by activation of β3-adnergenic receptor (β3-AR), as inhibition of β3-AR inhibited up-regulation of brown fat-specific markers. Similarly, limonene-mediated activation of ERK and up-regulation of key brown adipocyte specific markers were eliminated by treatment with ERK antagonist. Taken together, these results suggest that limonene induces browning of 3T3-L1 adipocytes via activation of β3-AR and the ERK signaling pathway. In conclusion, our findings suggest that limonene plays a dual modulatory role in induction of the brown adipocyte-like phenotype as well as promotion of lipid metabolism and thus may have potential therapeutic implications for treatment of obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Prolonged inorganic arsenite exposure suppresses insulin-stimulated AKT S473 phosphorylation and glucose uptake in 3T3-L1 adipocytes: Involvement of the adaptive antioxidant response

    International Nuclear Information System (INIS)

    Xue, Peng; Hou, Yongyong; Zhang, Qiang; Woods, Courtney G.; Yarborough, Kathy; Liu, Huiyu; Sun, Guifan; Andersen, Melvin E.; Pi, Jingbo

    2011-01-01

    Highlights: → In 3T3-L1 adipocytes iAs 3+ decreases insulin-stimulated glucose uptake. → iAs 3+ attenuates insulin-induced phosphorylation of AKT S473. → iAs 3+ activates the cellular adaptive oxidative stress response. → iAs 3+ impairs insulin-stimulated ROS signaling. → iAs 3+ decreases expression of adipogenic genes and GLUT4. -- Abstract: There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of type 2 diabetes (T2D). One critical feature of T2D is insulin resistance in peripheral tissues, especially in mature adipocytes, the hallmark of which is decreased insulin-stimulated glucose uptake (ISGU). Despite the deleterious effects of reactive oxygen species (ROS), they have been recognized as a second messenger serving an intracellular signaling role for insulin action. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central transcription factor regulating cellular adaptive response to oxidative stress. This study proposes that in response to arsenic exposure, the NRF2-mediated adaptive induction of endogenous antioxidant enzymes blunts insulin-stimulated ROS signaling and thus impairs ISGU. Exposure of differentiated 3T3-L1 cells to low-level (up to 2 μM) inorganic arsenite (iAs 3+ ) led to decreased ISGU in a dose- and time-dependent manner. Concomitant to the impairment of ISGU, iAs 3+ exposure significantly attenuated insulin-stimulated intracellular ROS accumulation and AKT S473 phosphorylation, which could be attributed to the activation of NRF2 and induction of a battery of endogenous antioxidant enzymes. In addition, prolonged iAs 3+ exposure of 3T3-L1 adipocytes resulted in significant induction of inflammatory response genes and decreased expression of adipogenic genes and glucose transporter type 4 (GLUT4), suggesting chronic inflammation and reduction in GLUT4 expression may also be involved in arsenic-induced insulin resistance in

  11. Prolonged inorganic arsenite exposure suppresses insulin-stimulated AKT S473 phosphorylation and glucose uptake in 3T3-L1 adipocytes: Involvement of the adaptive antioxidant response

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Peng [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); School of Public Health, China Medical University, Shenyang 110001 (China); Hou, Yongyong; Zhang, Qiang; Woods, Courtney G.; Yarborough, Kathy; Liu, Huiyu [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Sun, Guifan [School of Public Health, China Medical University, Shenyang 110001 (China); Andersen, Melvin E. [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Pi, Jingbo, E-mail: jpi@thehamner.org [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States)

    2011-04-08

    Highlights: {yields} In 3T3-L1 adipocytes iAs{sup 3+} decreases insulin-stimulated glucose uptake. {yields} iAs{sup 3+} attenuates insulin-induced phosphorylation of AKT S473. {yields} iAs{sup 3+} activates the cellular adaptive oxidative stress response. {yields} iAs{sup 3+} impairs insulin-stimulated ROS signaling. {yields} iAs{sup 3+} decreases expression of adipogenic genes and GLUT4. -- Abstract: There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of type 2 diabetes (T2D). One critical feature of T2D is insulin resistance in peripheral tissues, especially in mature adipocytes, the hallmark of which is decreased insulin-stimulated glucose uptake (ISGU). Despite the deleterious effects of reactive oxygen species (ROS), they have been recognized as a second messenger serving an intracellular signaling role for insulin action. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central transcription factor regulating cellular adaptive response to oxidative stress. This study proposes that in response to arsenic exposure, the NRF2-mediated adaptive induction of endogenous antioxidant enzymes blunts insulin-stimulated ROS signaling and thus impairs ISGU. Exposure of differentiated 3T3-L1 cells to low-level (up to 2 {mu}M) inorganic arsenite (iAs{sup 3+}) led to decreased ISGU in a dose- and time-dependent manner. Concomitant to the impairment of ISGU, iAs{sup 3+} exposure significantly attenuated insulin-stimulated intracellular ROS accumulation and AKT S473 phosphorylation, which could be attributed to the activation of NRF2 and induction of a battery of endogenous antioxidant enzymes. In addition, prolonged iAs{sup 3+} exposure of 3T3-L1 adipocytes resulted in significant induction of inflammatory response genes and decreased expression of adipogenic genes and glucose transporter type 4 (GLUT4), suggesting chronic inflammation and reduction in GLUT4

  12. Adipocyte dysfunction in a mouse model of polycystic ovary syndrome (PCOS: evidence of adipocyte hypertrophy and tissue-specific inflammation.

    Directory of Open Access Journals (Sweden)

    Joseph S Marino

    Full Text Available Clinical research shows an association between polycystic ovary syndrome (PCOS and chronic inflammation, a pathological state thought to contribute to insulin resistance. The underlying pathways, however, have not been defined. The purpose of this study was to characterize the inflammatory state of a novel mouse model of PCOS. Female mice lacking leptin and insulin receptors in pro-opiomelanocortin neurons (IR/LepR(POMC mice and littermate controls were evaluated for estrous cyclicity, ovarian and adipose tissue morphology, and body composition by QMR and CT scan. Tissue-specific macrophage infiltration and cytokine mRNA expression were measured, as well as circulating cytokine levels. Finally, glucose regulation during pregnancy was evaluated as a measure of risk for diabetes development. Forty-five percent of IR/LepR(POMC mice showed reduced or absent ovulation. IR/LepR(POMC mice also had increased fat mass and adipocyte hypertrophy. These traits accompanied elevations in macrophage accumulation and inflammatory cytokine production in perigonadal adipose tissue, liver, and ovary. These mice also exhibited gestational hyperglycemia as predicted. This report is the first to show the presence of inflammation in IR/LepR(POMC mice, which develop a PCOS-like phenotype. Thus, IR/LepR(POMC mice may serve as a new mouse model to clarify the involvement of adipose and liver tissue in the pathogenesis and etiology of PCOS, allowing more targeted research on the development of PCOS and potential therapeutic interventions.

  13. Degradation of brown adipocyte purine nucleotides regulates uncoupling protein 1 activity

    Directory of Open Access Journals (Sweden)

    Tobias Fromme

    2018-02-01

    Full Text Available Objective: Non-shivering thermogenesis in mammalian brown adipose tissue depends on thermogenic uncoupling protein 1. Its activity is triggered by free fatty acids while purine nucleotides mediate inhibition. During activation, it is thought that free fatty acids overcome purine-mediated inhibition. We measured the cellular concentration and the release of purine nucleotide metabolites to uncover a possible role of purine nucleotide degradation in uncoupling protein 1 activation. Methods: With mass spectrometry, purine nucleotide metabolites were quantified in cellular homogenates and supernatants of cultured primary brown adipocytes. We also determined oxygen consumption in response to a β-adrenergic agonist. Results: Upon adrenergic activation, brown adipocytes decreased the intracellular concentration of inhibitory nucleotides (ATP, ADP, GTP and GDP and released the respective degradation products. At the same time, an increase in cellular calcium occurred. None of these phenomena occurred in white adipocytes or myotubes. The brown adipocyte expression of enzymes implicated in purine metabolic remodeling is altered upon cold exposure. Pharmacological and genetic interference of purine metabolism altered uncoupling protein 1 mediated uncoupled respiration. Conclusion: Adrenergic stimulation of brown adipocytes lowers the intracellular concentration of purine nucleotides, thereby contributing to uncoupling protein 1 activation. Keywords: Purine nucleotides, Uncoupling protein 1, Brown adipose tissue, Non-shivering thermogenesis, HILIC-MS/MS, Guanosine monophosphate reductase

  14. Endoplasmic reticulum stress suppresses lipin-1 expression in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Nobuhiko, E-mail: ntkhs@hoku-iryo-u.ac.jp [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1, Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510 (Japan); Yoshizaki, Takayuki [Innovation Center, Kagoshima University, 1-21-40, Korimoto, Kagoshima 890-0065 (Japan); Hiranaka, Natsumi; Suzuki, Takeshi [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Yui, Tomoo; Akanuma, Masayoshi [Department of Fixed Prosthodontics and Oral Implantology, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Kanazawa, Kaoru [Department of Dental Anesthesiology, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Yoshida, Mika; Naito, Sumiyoshi [Department of Clinical Laboratory, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Fujiya, Mikihiro; Kohgo, Yutaka [Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1, Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510 (Japan); Ieko, Masahiro [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan)

    2013-02-01

    Highlights: ► Lipin-1 involves lipid metabolism, adipocyte differentiation, and inflammation. ► Adipose lipin-1 expression is reduced in obesity. ► ER stress suppresses lipin-1 expression in 3T3-L1 adipocytes. ► Activation of PPAR-γ recovers ER stress-induced lipin-1 reduction. -- Abstract: Lipin-1 plays crucial roles in the regulation of lipid metabolism and cell differentiation in adipocytes. In obesity, adipose lipin-1 mRNA expression is decreased and positively correlated with systemic insulin sensitivity. Amelioration of the lipin-1 depletion might be improved dysmetabolism. Although some cytokines such as TNF-α and interleukin-1β reduces adipose lipin-1 expression, the mechanism of decreased adipose lipin-1 expression in obesity remains unclear. Recently, endoplasmic reticulum (ER) stress is implicated in the pathogenesis of obesity. Here we investigated the role of ER stress on the lipin-1 expression in 3T3-L1 adipocytes. We demonstrated that lipin-1 expression was suppressed by the treatment with ER stress inducers (tunicamycin and thapsigargin) at transcriptional level. We also showed that constitutive lipin-1 expression could be maintained by peroxisome proliferator-activated receptor-γ in 3T3-L1 adipocytes. Activation of peroxisome proliferator-activated receptor-γ recovered the ER stress-induced lipin-1 suppression. These results suggested that ER stress might be involved in the pathogenesis of obesity through lipin-1 depletion.

  15. Microparticles release by adipocytes act as "find-me" signals to promote macrophage migration.

    Directory of Open Access Journals (Sweden)

    Akiko Eguchi

    Full Text Available Macrophage infiltration of adipose tissue during weight gain is a central event leading to the metabolic complications of obesity. However, what are the mechanisms attracting professional phagocytes to obese adipose tissue remains poorly understood. Here, we demonstrate that adipocyte-derived microparticles (MPs are critical "find-me" signals for recruitment of monocytes and macrophages. Supernatants from stressed adipocytes stimulated the attraction of monocyte cells and primary macrophages. The activation of caspase 3 was required for release of these signals. Adipocytes exposed to saturated fatty acids showed marked release of MPs into the supernatant while common genetic mouse models of obesity demonstrate high levels of circulating adipocyte-derived MPs. The release of MPs was highly regulated and dependent on caspase 3 and Rho-associated kinase. Further analysis identified these MPs as a central chemoattractant in vitro and in vivo. In addition, intravenously transplanting circulating MPs from the ob/ob mice lead to activation of monocytes in circulation and adipose tissue of the wild type mice. These data identify adipocyte-derived MPs as novel "find me" signals that contributes to macrophage infiltration associated with obesity.

  16. Adipocytes and Macrophages Interplay in the Orchestration of Tumor Microenvironment: New Implications in Cancer Progression

    Directory of Open Access Journals (Sweden)

    Luís Henrique Corrêa

    2017-09-01

    Full Text Available Inflammation has been known as one of the main keys to the establishment and progression of cancers. Chronic low-grade inflammation is also a strategic condition that underlies the causes and development of metabolic syndrome and obesity. Moreover, obesity has been largely related to poor prognosis of tumors by modulating tumor microenvironment with secretion of several inflammatory mediators by tumor-associated adipocytes (TAAs, which can modulate and recruit tumor-associated macrophages. Thus, the understanding of cellular and molecular mechanisms that underlay and link inflammation, obesity, and cancer is crucial to identify potential targets that interfere with this important route. Knowledge about the exact role of each component of the tumor microenvironment is not yet fully understood, but the new insights in literature highlight the essential role of adipocytes and macrophages interplay as key factor to determine the fate of cancer progression. In this review article, we focus on the functions of adipocytes and macrophages orchestrating cellular and molecular mechanisms that lead to inflammatory modulation in tumor microenvironment, which will be crucial to cancer establishment. We also emphasized the mechanisms by which the tumor promotes itself by recruiting and polarizing macrophages, discussing the role of adipocytes in this process. In addition, we discuss here the newest possible anticancer therapeutic treatments aiming to retard the development of the tumor based on what is known about cancer, adipocyte, and macrophage polarization.

  17. Endoplasmic reticulum stress suppresses lipin-1 expression in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Takahashi, Nobuhiko; Yoshizaki, Takayuki; Hiranaka, Natsumi; Suzuki, Takeshi; Yui, Tomoo; Akanuma, Masayoshi; Kanazawa, Kaoru; Yoshida, Mika; Naito, Sumiyoshi; Fujiya, Mikihiro; Kohgo, Yutaka; Ieko, Masahiro

    2013-01-01

    Highlights: ► Lipin-1 involves lipid metabolism, adipocyte differentiation, and inflammation. ► Adipose lipin-1 expression is reduced in obesity. ► ER stress suppresses lipin-1 expression in 3T3-L1 adipocytes. ► Activation of PPAR-γ recovers ER stress-induced lipin-1 reduction. -- Abstract: Lipin-1 plays crucial roles in the regulation of lipid metabolism and cell differentiation in adipocytes. In obesity, adipose lipin-1 mRNA expression is decreased and positively correlated with systemic insulin sensitivity. Amelioration of the lipin-1 depletion might be improved dysmetabolism. Although some cytokines such as TNF-α and interleukin-1β reduces adipose lipin-1 expression, the mechanism of decreased adipose lipin-1 expression in obesity remains unclear. Recently, endoplasmic reticulum (ER) stress is implicated in the pathogenesis of obesity. Here we investigated the role of ER stress on the lipin-1 expression in 3T3-L1 adipocytes. We demonstrated that lipin-1 expression was suppressed by the treatment with ER stress inducers (tunicamycin and thapsigargin) at transcriptional level. We also showed that constitutive lipin-1 expression could be maintained by peroxisome proliferator-activated receptor-γ in 3T3-L1 adipocytes. Activation of peroxisome proliferator-activated receptor-γ recovered the ER stress-induced lipin-1 suppression. These results suggested that ER stress might be involved in the pathogenesis of obesity through lipin-1 depletion

  18. E4orf1 induction in adipose tissue promotes insulin-independent signaling in the adipocyte.

    Science.gov (United States)

    Kusminski, Christine M; Gallardo-Montejano, Violeta I; Wang, Zhao V; Hegde, Vijay; Bickel, Perry E; Dhurandhar, Nikhil V; Scherer, Philipp E

    2015-10-01

    Type 2 diabetes remains a worldwide epidemic with major pathophysiological changes as a result of chronic insulin resistance. Insulin regulates numerous biochemical pathways related to carbohydrate and lipid metabolism. We have generated a novel mouse model that allows us to constitutively activate, in an inducible fashion, the distal branch of the insulin signaling transduction pathway specifically in adipocytes. Using the adenoviral 36 E4orf1 protein, we chronically stimulate locally the Ras-ERK-MAPK signaling pathway. At the whole body level, this leads to reduced body-weight gain under a high fat diet challenge. Despite overlapping glucose tolerance curves, there is a reduced requirement for insulin action under these conditions. The mice further exhibit reduced circulating adiponectin levels that ultimately lead to impaired lipid clearance, and inflamed and fibrotic white adipose tissues. Nevertheless, they are protected from diet-induced hepatic steatosis. As we observe constitutively elevated p-Akt levels in the adipocytes, even under conditions of low insulin levels, this pinpoints enhanced Ras-ERK-MAPK signaling in transgenic adipocytes as a potential alternative route to bypass proximal insulin signaling events. We conclude that E4orf1 expression in the adipocyte leads to enhanced baseline activation of the distal insulin signaling node, yet impaired insulin receptor stimulation in the presence of insulin, with important implications for the regulation of adiponectin secretion. The resulting systemic phenotype is complex, yet highlights the powerful nature of manipulating selective branches of the insulin signaling network within the adipocyte.

  19. Obesity is associated with depot-specific alterations in adipocyte DNA methylation and gene expression

    DEFF Research Database (Denmark)

    Sonne, Si Brask; Yadav, Rachita; Yin, Guangliang

    2017-01-01

    The present study aimed to identify genes exhibiting concomitant obesity-dependent changes in DNA methylation and gene expression in adipose tissues in the mouse using diet-induced obese (DIO) C57BL/6J and genetically obese ob/ob mice as models. Mature adipocytes were isolated from epididymal...... and inguinal adipose tissues of ob/ob and DIO C57BL/6J mice. DNA methylation was analyzed by MeDIP-sequencing and gene expression by microarray analysis. The majority of differentially methylated regions (DMRs) were hypomethylated in obese mice. Global methylation of long interspersed elements indicated......57BL/6J mice occurred primarily in exons, whereas inguinal adipocytes of ob/ob mice exhibited a higher enrichment of DMRs in promoter regions than in other regions of the genome, suggesting an influence of leptin on DNA methylation in inguinal adipocytes. We observed altered methylation...

  20. Inhibition of fatty acid synthesis in isolated adipocytes by 5-(tetradecyloxy)-2-furoic acid.

    Science.gov (United States)

    Halvorson, D L; McCune, S A

    1984-11-01

    The compound 5-(tetradecyloxy)-2-furoic acid (TOFA), a hypolipidemic agent, inhibits fatty acid synthesis, lactate and pyruvate accumulation and CO2 release in isolated rat adipocytes. TOFA stimulates the accumulation of citrate. ATP levels are not lowered by TOFA. In comparison with the natural fatty acid, oleate, TOFA exhibited a much greater inhibitory effect on lipogenesis. TOFyl-CoA formation within intact adipocytes was demonstrated. Although not inhibited by TOFA, acetyl-CoA carboxylase is inhibited by TOFyl-CoA. It is proposed that many of the metabolic effects of TOFA in isolated adipocytes can be explained by TOFyl-CoA inhibition of acetyl-CoA carboxylase. TOFA inhibits glycolysis as a secondary event with the primary event of inhibition of fatty acid synthesis causing an accumulation of citrate which is an inhibitor of phosphofructokinase.

  1. Insulin binding and glucose transport in adipocytes of acarbose-treated Zucker lean and obese rats.

    Science.gov (United States)

    Vasselli, J R; Flory, T; Fried, S K

    1987-01-01

    The intestinal glucosidase inhibitor acarbose was administered as a dietary admix (30 mg/100 g chow diet) to male Zucker obese and lean rats. After 15 weeks, epidiymal fat pads were removed and adipocytes isolated by collagenase digestion. Equilibrium binding of A-14 tyrosine 125I-insulin, and transport of U-14C-glucose was determined was adipocytes incubated for 50 min at 37 degrees C in 0-16000 pM insulin. Insulin binding/cell was enhanced two-fold in lean (P less than 0.01) and obese (n.s.) drug groups. In drug-treated leans, increased sensitivity of glucose transport to submaximally stimulating concentrations of insulin was observed (P less than 0.02). For both genotypes, acarbose mildly decreased insulin levels and body weight gain, although adipocyte size was unaffected. Results indicate that enhanced insulin binding accompanies metabolic improvements induced by acarbose in lean Zucker rats.

  2. Cell-cycle arrest in mature adipocytes impairs BAT development but not WAT browning, and reduces adaptive thermogenesis in mice.

    Science.gov (United States)

    Okamatsu-Ogura, Yuko; Fukano, Keigo; Tsubota, Ayumi; Nio-Kobayashi, Junko; Nakamura, Kyoko; Morimatsu, Masami; Sakaue, Hiroshi; Saito, Masayuki; Kimura, Kazuhiro

    2017-07-27

    We previously reported brown adipocytes can proliferate even after differentiation. To test the involvement of mature adipocyte proliferation in cell number control in fat tissue, we generated transgenic (Tg) mice over-expressing cell-cycle inhibitory protein p27 specifically in adipocytes, using the aP2 promoter. While there was no apparent difference in white adipose tissue (WAT) between wild-type (WT) and Tg mice, the amount of brown adipose tissue (BAT) was much smaller in Tg mice. Although BAT showed a normal cellular morphology, Tg mice had lower content of uncoupling protein 1 (UCP1) as a whole, and attenuated cold exposure- or β3-adrenergic receptor (AR) agonist-induced thermogenesis, with a decrease in the number of mature brown adipocytes expressing proliferation markers. An agonist for the β3-AR failed to increase the number of proliferating brown adipocytes, UCP1 content in BAT, and oxygen consumption in Tg mice, although the induction and the function of beige adipocytes in inguinal WAT from Tg mice were similar to WT mice. These results show that brown adipocyte proliferation significantly contributes to BAT development and adaptive thermogenesis in mice, but not to induction of beige adipocytes.

  3. The Regulation of Chemerin and CMKLR1 Genes Expression by TNF-α, Adiponectin, and Chemerin Analog in Bovine Differentiated Adipocytes

    OpenAIRE

    Y. Suzuki; Y. H. Hong; S. H. Song; A. Ardiyanti; D. Kato; K. H. So; K. Katoh; S. G Roh

    2012-01-01

    Adipokines, adipocyte-derived protein, have important roles in various kinds of physiology including energy homeostasis. Chemerin, one of adipocyte-derived adipokines, is highly expressed in differentiated adipocytes and is known to induce macrophage chemotaxis and glucose intolerance. The objective of the present study was to investigate the changes of chemerin and the chemokine-like-receptor 1 (CMKLR1) gene expression levels during differentiation of the bovine adipocyte and in differentiat...

  4. Prolonged decrease of adipocyte size after rosiglitazone treatment in high- and low-fat-fed rats.

    Science.gov (United States)

    Johnson, Julia A; Trasino, Steven E; Ferrante, Anthony W; Vasselli, Joseph R

    2007-11-01

    The anti-diabetic thiazolidinediones (TZDs) stimulate adipocyte differentiation and decrease mean adipocyte size. However, whether these smaller, more insulin-sensitive adipocytes maintain their size after TZD therapy is discontinued has not been studied. Adult female Sprague-Dawley rats were fed a low-fat (10% fat) diet or, to elevate body weight (BW), a high-fat (HF) diet (45% fat) for 6 weeks. Rats were initially randomized to groups (n = 12) fed either low-fat or HF diets, with or without the TZD rosiglitazone (ROSI; 5 mg/kg per day), for 6 weeks. ROSI was then discontinued, and all animals were fed HF for another 6 weeks before sacrifice. Retroperitoneal (RP) adipose tissue morphology was determined from tissue collected by serial biopsies before and after 6 weeks of ROSI treatment and at sacrifice. Measures of BW and adiposity did not differ among groups 6 weeks after stopping ROSI treatment. However, during treatment, ROSI in both diets significantly decreased RP adipocyte size and increased RP DNA content, and these effects continued to be observed after discontinuing treatment. ROSI administration also decreased circulating insulin, leptin, and triglycerides and increased circulating adiponectin levels; however, these effects were reversed on stopping treatment. These results demonstrated that TZD-induced effects on adipocyte size and number were maintained after discontinuing treatment, even with consumption of an obesigenic diet. However, additional studies are needed to determine whether TZD-treated animals eventually achieve an adipocyte size similar to that of untreated animals at the expense of a higher BW.

  5. Increased extracellular and intracellular Ca{sup 2+} lead to adipocyte accumulation in bone marrow stromal cells by different mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Ryota, E-mail: hryota@juntendo.ac.jp [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Katoh, Youichi, E-mail: katoyo@juntendo-urayasu.jp [Juntendo University Faculty of International Liberal Arts, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Department of Cardiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Miyamoto, Yuki [Juntendo University Faculty of Health Care and Nursing, Takasu 2-5-1, Urayasu-shi, Chiba 279-0023 (Japan); Itoh, Seigo; Daida, Hiroyuki [Department of Cardiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Nakazato, Yuji [Center for Environmental Research, Department of Cardiology, Juntendo University Faculty of Medicine Urayasu Hospital, Tomioka 2-1-1, Urayasu-shi, Chiba 279-0022 (Japan); Okada, Takao [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2015-02-20

    Mesenchymal stem cells found in bone marrow stromal cells (BMSCs) are the common progenitors for both adipocyte and osteoblast. An increase in marrow adipogenesis is associated with age-related osteopenia and anemia. Both extracellular and intracellular Ca{sup 2+} ([Ca{sup 2+}]{sub o} and [Ca{sup 2+}]{sub i}) are versatile signaling molecules that are involved in the regulation of cell functions, including proliferation and differentiation. We have recently reported that upon treatment of BMSCs with insulin and dexamethasone, both high [Ca{sup 2+}]{sub o} and high [Ca{sup 2+}]{sub i} enhanced adipocyte accumulation, which suggested that increases in [Ca{sup 2+}]{sub o} caused by bone resorption may accelerate adipocyte accumulation in aging and diabetic patients. In this study, we used primary mouse BMSCs to investigate the mechanisms by which high [Ca{sup 2+}]{sub o} and high [Ca{sup 2+}]{sub i} may enhance adipocyte accumulation. In the process of adipocyte accumulation, two important keys are adipocyte differentiation and the proliferation of BMSCs, which have the potential to differentiate into adipocytes. Use of MTT assay and real-time RT-PCR revealed that high [Ca{sup 2+}]{sub i} (ionomycin)-dependent adipocyte accumulation is caused by enhanced proliferation of BMSCs but not enhanced differentiation into adipocytes. Using fura-2 fluorescence-based approaches, we showed that high [Ca{sup 2+}]{sub o} (addition of CaCl{sub 2}) leads to increases in [Ca{sup 2+}]{sub i}. Flow cytometric methods revealed that high [Ca{sup 2+}]{sub o} suppressed the phosphorylation of ERK independently of intracellular Ca{sup 2+}. The inhibition of ERK by U0126 and PD0325901 enhanced the differentiation of BMSCs into adipocytes. These data suggest that increased extracellular Ca{sup 2+} provides the differentiation of BMSCs into adipocytes by the suppression of ERK activity independently of increased intracellular Ca{sup 2+}, which results in BMSC proliferation. - Highlights:

  6. Adipocyte size and cellular expression of caveolar proteins analyzed by confocal microscopy

    DEFF Research Database (Denmark)

    Hulstrøm, Veronica; Prats Gavalda, Clara; Vinten, Jørgen

    2013-01-01

    Caveolae are abundant in adipocytes and are involved in the regulation of lipid accumulation, which is the main volume determinant of these cells. We have developed and applied a confocal microscopic technique for measuring individual cellular expression of the caveolar proteins cavin-1 and caveo......Caveolae are abundant in adipocytes and are involved in the regulation of lipid accumulation, which is the main volume determinant of these cells. We have developed and applied a confocal microscopic technique for measuring individual cellular expression of the caveolar proteins cavin-1...

  7. Mature adipocytes may be a source of stem cells for tissue engineering

    International Nuclear Information System (INIS)

    Fernyhough, M.E.; Hausman, G.J.; Guan, L.L.; Okine, E.; Moore, S.S.; Dodson, M.V.

    2008-01-01

    Adipose tissue contains a large portion of stem cells. These cells appear morphologically like fibroblasts and are primarily derived from the stromal cell fraction. Mature (lipid-filled) adipocytes possess the ability to become proliferative cells and have been shown to produce progeny cells that possess the same morphological (fibroblast-like) appearance as the stem cells from the stromal fraction. A closer examination of mature adipocyte-derived progeny cells may prove to be an emerging area of growth/metabolic physiology that may modify present thinking about adipose tissue renewal capabilities. Knowledge of these cells may also prove beneficial in cell-based therapies for tissue repair, regeneration, or engineering

  8. Effect of triiodothyronine and insulin on glucose metabolism in tissue explants and isolated adipocytes from lean and obese Zucker rats

    International Nuclear Information System (INIS)

    Bailey, J.W.

    1985-01-01

    Glucose metabolism in adipocytes from 6 week old lean and obese Zucker rats were sensitive to direct and chronic treatment with insulin and triidothyronine (T 3 ). Insulin had a large stimulatory effect on glucose metabolism in acutely isolated adipocytes. This effect was greater in the lean than in the obese. Fatty acid, CO 2 , and glycerol-glyceride formation from radiolabeled glucose was elevated in the obese over the leans. Pretreatment of isolated adipocytes with pharmacological concentrations of T 3 for 30 minutes prior to the measurement of glucose metabolism had a greater effect on lean than obese adipocytes. The presence of insulin was required to observe the acute effects of T 3 . A 2-hour exposure to physiological levels of T 3 in the presence of insulin in both lean and obese adipocytes decreased lipogenesis. In the absence of insulin, a 2 hour pretreatment with physiological levels of T 3 in tissue from a euthyroid animal produced increased lipogenesis

  9. Effects of Leucine Supplementation and Serum Withdrawal on Branched-Chain Amino Acid Pathway Gene and Protein Expression in Mouse Adipocytes

    Science.gov (United States)

    Vivar, Juan C.; Knight, Megan S.; Pointer, Mildred A.; Gwathmey, Judith K.; Ghosh, Sujoy

    2014-01-01

    The essential branched-chain amino acids (BCAA), leucine, valine and isoleucine, are traditionally associated with skeletal muscle growth and maintenance, energy production, and generation of neurotransmitter and gluconeogenic precursors. Recent evidence from human and animal model studies has established an additional link between BCAA levels and obesity. However, details of the mechanism of regulation of BCAA metabolism during adipogenesis are largely unknown. We interrogated whether the expression of genes and proteins involved in BCAA metabolism are sensitive to the adipocyte differentiation process, and responsive to nutrient stress from starvation or BCAA excess. Murine 3T3-L1 preadipocytes were differentiated to adipocytes under control conditions and under conditions of L-leucine supplementation or serum withdrawal. RNA and proteins were isolated at days 0, 4 and 10 of differentiation to represent pre-differentiation, early differentiation and late differentiation stages. Expression of 16 BCAA metabolism genes was quantified by quantitative real-time PCR. Expression of the protein levels of branched-chain amino acid transaminase 2 (Bcat2) and branched-chain alpha keto acid dehydrogenase (Bckdha) was quantified by immunoblotting. Under control conditions, all genes displayed induction of gene expression during early adipogenesis (Day 4) compared to Day 0. Leucine supplementation resulted in an induction of Bcat2 and Bckdha genes during early and late differentiation. Western blot analysis demonstrated condition-specific concordance between gene and protein expression. Serum withdrawal resulted in undetectable Bcat2 and Bckdha protein levels at all timepoints. These results demonstrate that the expression of genes related to BCAA metabolism are regulated during adipocyte differentiation and influenced by nutrient levels. These results provide additional insights on how BCAA metabolism is associated with adipose tissue function and extends our understanding of

  10. Effects of leucine supplementation and serum withdrawal on branched-chain amino acid pathway gene and protein expression in mouse adipocytes.

    Directory of Open Access Journals (Sweden)

    Abderrazak Kitsy

    Full Text Available The essential branched-chain amino acids (BCAA, leucine, valine and isoleucine, are traditionally associated with skeletal muscle growth and maintenance, energy production, and generation of neurotransmitter and gluconeogenic precursors. Recent evidence from human and animal model studies has established an additional link between BCAA levels and obesity. However, details of the mechanism of regulation of BCAA metabolism during adipogenesis are largely unknown. We interrogated whether the expression of genes and proteins involved in BCAA metabolism are sensitive to the adipocyte differentiation process, and responsive to nutrient stress from starvation or BCAA excess. Murine 3T3-L1 preadipocytes were differentiated to adipocytes under control conditions and under conditions of L-leucine supplementation or serum withdrawal. RNA and proteins were isolated at days 0, 4 and 10 of differentiation to represent pre-differentiation, early differentiation and late differentiation stages. Expression of 16 BCAA metabolism genes was quantified by quantitative real-time PCR. Expression of the protein levels of branched-chain amino acid transaminase 2 (Bcat2 and branched-chain alpha keto acid dehydrogenase (Bckdha was quantified by immunoblotting. Under control conditions, all genes displayed induction of gene expression during early adipogenesis (Day 4 compared to Day 0. Leucine supplementation resulted in an induction of Bcat2 and Bckdha genes during early and late differentiation. Western blot analysis demonstrated condition-specific concordance between gene and protein expression. Serum withdrawal resulted in undetectable Bcat2 and Bckdha protein levels at all timepoints. These results demonstrate that the expression of genes related to BCAA metabolism are regulated during adipocyte differentiation and influenced by nutrient levels. These results provide additional insights on how BCAA metabolism is associated with adipose tissue function and extends our

  11. Empagliflozin lessened cardiac injury and reduced visceral adipocyte hypertrophy in prediabetic rats with metabolic syndrome.

    Science.gov (United States)

    Kusaka, Hiroaki; Koibuchi, Nobutaka; Hasegawa, Yu; Ogawa, Hisao; Kim-Mitsuyama, Shokei

    2016-11-11

    The potential benefit of SGLT2 inhibitors in metabolic syndrome is with prediabetic stage unclear. This work was undertaken to investigate the non-glycemic effect of empagliflozin on metabolic syndrome rats with prediabetes. SHR/NDmcr-cp(+/+) rats (SHRcp), a model of metabolic syndrome with prediabetes, were given empagliflozin for 10 weeks to examine the effects on urinary sodium and water balance, visceral and subcutaneous adipocyte, and cardiac injury. Further, the effect of empagliflozin on blood pressure and autonomic nervous system was continuously investigated by using radiotelemetry system. Empagliflozin significantly reduced urinary sodium and water balance of SHRcp only within 1 week of the treatment, but later than 1 week did not alter them throughout the treatment. Empagliflozin significantly reduced body weight of SHRcp, which was mainly attributed to the significant reduction of subcutaneous fat mass. Empagliflozin significantly reduced the size of visceral adipocytes and increased the number of smaller size of adipocytes, which was associated with the attenuation of oxidative stress. Empagliflozin ameliorated cardiac hypertrophy and fibrosis of SHRcp, in association with the attenuation of cardiac oxidative stress and inflammation. However, empagliflozin did not significantly change blood pressure, heart rate, sympathetic activity, or baroreceptor function, as evidenced by radiotelemetry analysis. Our present work provided the evidence that SGLT2 inhibition reduced visceral adipocytes hypertrophy and ameliorated cardiac injury in prediabetic metabolic syndrome rat, independently of diuretic effect or blood pressure lowering effect. Thus, SGLT2 inhibition seems to be a promising therapeutic strategy for prediabetic metabolic syndrome.

  12. Radiation inactivation target size of rat adipocyte glucose transporters in the plasma membrane and intracellular pools

    International Nuclear Information System (INIS)

    Jacobs, D.B.; Berenski, C.J.; Spangler, R.A.; Jung, C.Y.

    1987-01-01

    The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior to and after insulin treatment, respectively. In the case of microsomal membranes, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses, which may be interpreted as indicating the presence of a radiation-sensitive inhibitor. These results suggest that the adipocyte glucose transporter occurs as a monomer in the plasma membrane while existing in the intracellular reserve pool either as a homodimer or as a stoichiometric complex with a protein of an approximately equal size

  13. Mangiferin ameliorates insulin resistance by inhibiting inflammation and regulatiing adipokine expression in adipocytes under hypoxic condition.

    Science.gov (United States)

    Yang, Chao-Qiang; Xu, Jing-Hua; Yan, Dan-Dan; Liu, Bao-Lin; Liu, Kang; Huang, Fang

    2017-09-01

    Adipose tissue hypoxia has been recognized as the initiation of insulin resistance syndromes. The aim of the present study was to investigate the effects of mangiferin on the insulin signaling pathway and explore whether mangiferin could ameliorate insulin resistance caused by hypoxia in adipose tissue. Differentiated 3T3-L1 adipocytes were incubated under normal and hypoxic conditions, respectively. Protein expressions were analyzed by Western blotting. Inflammatory cytokines and HIF-1-dependent genes were tested by ELISA and q-PCR, respectively. The glucose uptake was detected by fluorescence microscopy. HIF-1α was abundantly expressed during 8 h of hypoxic incubation. Inflammatory reaction was activated by up-regulated NF-κB phosphorylation and released cytokines like IL-6 and TNF-α. Glucose uptake was inhibited and insulin signaling pathway was damaged as well. Mangiferin substantially inhibited the expression of HIF-1α. Lactate acid and lipolysis, products released by glycometabolism and lipolysis, were also inhibited. The expression of inflammatory cytokines was significantly reduced and the damaged insulin signaling pathway was restored to proper functional level. The glucose uptake of hypoxic adipocytes was promoted and the dysfunction of adipocytes was relieved. These results showed that mangiferin could not only improve the damaged insulin signaling pathway in hypoxic adipocytes, but also ameliorate inflammatory reaction and insulin resistance caused by hypoxia. Copyright © 2017 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  14. The relationship of omental and subcutaneous adipocyte size to metabolic disease in severe obesity.

    LENUS (Irish Health Repository)

    O'Connell, Jean

    2010-01-01

    Several studies have reported the existence of a subgroup of obese individuals with normal metabolic profiles. It remains unclear what factors are responsible for this phenomenon. We proposed that adipocyte size might be a key factor in the protection of metabolically healthy obese (MHO) individuals from the adverse effects of obesity.

  15. beta-adrenoceptors mediate inhibition of lipolysis in adipocytes of tilapia (Oreochromis mossambicus)

    NARCIS (Netherlands)

    Vianen, GJ; Obels, PP; Van Den Thillart, GEEJM; Zaagsma, J

    The regulation of triglyceride mobilization by catecholamines was investigated in the teleost fish Oreochromis mossambicus (tilapia) in vivo and in vitro. In vitro experiments were carried out with adipocytes that were isolated for the first time from fish adipose tissue. For the in vivo

  16. The retinoblastoma-histone deacetylase 3 complex inhibits PPARgamma and adipocyte differentiation

    DEFF Research Database (Denmark)

    Fajas, Lluis; Egler, Viviane; Reiter, Raphael

    2002-01-01

    The retinoblastoma protein (RB) has previously been shown to facilitate adipocyte differentiation by inducing cell cycle arrest and enhancing the transactivation by the adipogenic CCAAT/enhancer binding proteins (C/EBP). We show here that the peroxisome proliferator-activated receptor gamma...

  17. Effect of insulin and glucocorticoids on glucose transporters in rat adipocytes

    International Nuclear Information System (INIS)

    Carter-Su, C.; Okamoto, K.

    1987-01-01

    The ability of glucocorticoids to modify the effect of insulin on glucose (L-1- 3 H(N)]glucose and D-[ 14 C-U]glucose) transport was investigated in both intact isolated rat adipocytes and in membranes isolated from hormone-treated adipocytes. In intact adipocytes, dexamethasone, a potent synthetic glucocorticoid, inhibited insulin-stimulated 3-O-methylglucose transport at all concentrations of insulin tested. Insulin sensitivity, as well as the maximal response to insulin, was decreased by dexamethasone in the absence of a change in 125 I insulin binding. The inhibition was observed regardless of which hormone acted first, was blocked by actinomycin D, and resulted from a decrease in V/sub max/ rather than an increase in K/sub t/ of transport. In plasma membranes isolated from insulin-treated adipocytes, glucose transport activity and the amount of glucose transporter covalently labeled with [ 3 H]cytochalasin B were increased in parallel in a dose-dependent fashion. The amount of labeled transporter in a low-density microsomal fraction (LDMF) was decreased in a reciprocal fashion. In contrast, addition of dexamethasone to insulin-stimulated cells caused decreases in both transport activity and amount of labeled transporter in the plasma membranes. This was accompanied by a small increase in the amount of [ 3 H]cytochalasin B incorporated into the glucose transporter in the LDMF. These results are consistent with both insulin and glucocorticoids altering the distribution of glucose transporters between the plasma membrane and LDMF, in opposite directions

  18. Increased Adipocyte Size, Macrophage Infiltration, and Adverse Local Adipokine Profile in Perirenal Fat in Cushing's Syndrome.

    Science.gov (United States)

    Roerink, Sean H P P; Wagenmakers, Margreet A E M; Langenhuijsen, Johan F; Ballak, Dov B; Rooijackers, Hanne M M; d'Ancona, Frank C; van Dielen, François M; Smit, Jan W A; Plantinga, Theo S; Netea-Maier, Romana T; Hermus, Ad R M M

    2017-08-01

    To analyze changes in fat cell size, macrophage infiltration, and local adipose tissue adipokine profiles in different fat depots in patients with active Cushing's syndrome. Subcutaneous (SC) and perirenal (PR) adipose tissue of 10 patients with Cushing's syndrome was compared to adipose tissue of 10 gender-, age-, and BMI-matched controls with regard to adipocyte size determined by digital image analysis on hematoxylin and eosin stainings, macrophage infiltration determined by digital image analysis on CD68 stainings, and adipose tissue leptin and adiponectin levels using fluorescent bead immunoassays and ELISA techniques. Compared to the controls, mean adipocyte size was larger in PR adipose tissue in patients. The percentage of macrophage infiltration of the PR adipose tissue and PR adipose tissue lysate leptin levels were higher and adiponectin levels were lower in SC and PR adipose tissue lysates in patients. The adiponectin levels were also lower in the SC adipose tissue supernatants of patients. Associations were found between the severity of hypercortisolism and PR adipocyte size. Cushing's syndrome is associated with hypertrophy of PR adipocytes and a higher percentage of macrophage infiltration in PR adipose tissue. These changes are associated with an adverse local adipokine profile. © 2017 The Obesity Society.

  19. 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.

  20. 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

    Cold adaptation elicits a paradoxical simultaneous induction of fatty acid synthesis and beta-oxidation in brown adipose tissue. We show here that cold exposure coordinately induced liver X receptor alpha (LXRalpha), adipocyte determination and differentiation-dependent factor 1 (ADD1)/sterol...

  1. Adipocyte fetuin-A contributes to macrophage migration into adipose tissue and polarization of macrophages.

    Science.gov (United States)

    Chatterjee, Priyajit; Seal, Soma; Mukherjee, Sandip; Kundu, Rakesh; Mukherjee, Sutapa; Ray, Sukanta; Mukhopadhyay, Satinath; Majumdar, Subeer S; Bhattacharya, Samir

    2013-09-27

    Macrophage infiltration into adipose tissue during obesity and their phenotypic conversion from anti-inflammatory M2 to proinflammatory M1 subtype significantly contributes to develop a link between inflammation and insulin resistance; signaling molecule(s) for these events, however, remains poorly understood. We demonstrate here that excess lipid in the adipose tissue environment may trigger one such signal. Adipose tissue from obese diabetic db/db mice, high fat diet-fed mice, and obese diabetic patients showed significantly elevated fetuin-A (FetA) levels in respect to their controls; partially hepatectomized high fat diet mice did not show noticeable alteration, indicating adipose tissue to be the source of this alteration. In adipocytes, fatty acid induces FetA gene and protein expressions, resulting in its copious release. We found that FetA could act as a chemoattractant for macrophages. To simulate lipid-induced inflammatory conditions when proinflammatory adipose tissue and macrophages create a niche of an altered microenvironment, we set up a transculture system of macrophages and adipocytes; the addition of fatty acid to adipocytes released FetA into the medium, which polarized M2 macrophages to M1. This was further confirmed by direct FetA addition to macrophages. Taken together, lipid-induced FetA from adipocytes is an efficient chemokine for macrophage migration and polarization. These findings open a new dimension for understanding obesity-induced inflammation.

  2. TC10 is regulated by caveolin in 3T3-L1 adipocytes.

    Directory of Open Access Journals (Sweden)

    Dave Bridges

    Full Text Available TC10 is a small GTPase found in lipid raft microdomains of adipocytes. The protein undergoes activation in response to insulin, and plays a key role in the regulation of glucose uptake by the hormone.TC10 requires high concentrations of magnesium in order to stabilize guanine nucleotide binding. Kinetic analysis of this process revealed that magnesium acutely decreased the nucleotide release and exchange rates of TC10, suggesting that the G protein may behave as a rapidly exchanging, and therefore active protein in vivo. However, in adipocytes, the activity of TC10 is not constitutive, indicating that mechanisms must exist to maintain the G protein in a low activity state in untreated cells. Thus, we searched for proteins that might bind to and stabilize TC10 in the inactive state. We found that Caveolin interacts with TC10 only when GDP-bound and stabilizes GDP binding. Moreover, knockdown of Caveolin 1 in 3T3-L1 adipocytes increased the basal activity state of TC10.Together these data suggest that TC10 is intrinsically active in vivo, but is maintained in the inactive state by binding to Caveolin 1 in 3T3-L1 adipocytes under basal conditions, permitting its activation by insulin.

  3. Kaempferol Isolated from Nelumbo nucifera Inhibits Lipid Accumulation and Increases Fatty Acid Oxidation Signaling in Adipocytes.

    Science.gov (United States)

    Lee, Bonggi; Kwon, Misung; Choi, Jae Sue; Jeong, Hyoung Oh; Chung, Hae Young; Kim, Hyeung-Rak

    2015-12-01

    Stamens of Nelumbo nucifera Gaertn have been used as a Chinese medicine due to its antioxidant, hypoglycemic, and antiatherogenic activity. However, the effects of kaempferol, a main component of N. nucifera, on obesity are not fully understood. We examined the effect of kaempferol on adipogenesis and fatty acid oxidation signaling pathways in 3T3-L1 adipocytes. Kaempferol reduced cytoplasmic triglyceride (TG) accumulation in dose and time-dependent manners during adipocyte differentiation. Accumulation of TG was rapidly reversed by retrieving kaempferol treatment. Kaempferol broadly decreased mRNA or protein levels of adipogenic transcription factors and their target genes related to lipid accumulation. Kaempferol also suppressed glucose uptake and glucose transporter GLUT4 mRNA expression in adipocytes. Furthermore, protein docking simulation suggests that Kaempferol can directly bind to and activate peroxisome proliferator-activated receptor (PPAR)-α by forming hydrophobic interactions with VAL324, THR279, and LEU321 residues of PPARα. The binding affinity was higher than a well-known PPARα agonist fenofibrate. Consistently, mRNA expression levels of PPARα target genes were increased. Our study indicates while kaempferol inhibits lipogenic transcription factors and lipid accumulation, it may bind to PPARα and stimulate fatty acid oxidation signaling in adipocytes.

  4. OXIDATIVE MODIFICATION OF PROTEINS AND GLUTATHIONE SYSTEM IN ADIPOCYTES UNDER DIABETES

    Directory of Open Access Journals (Sweden)

    Ye. V. Shakhristova

    2014-01-01

    Full Text Available Currently, diabetes ranks third in relation to medical and social significance after cardiovascular diseases and cancer and is the leading cause of blindness; it greatly increases the risk of myocardial infarction, coronary heart disease, nephropathy and hypertension in patients with this disorder; therefore clinical and experimental studies aimed at investigation of diabetes emergence and development mechanisms are urgent.The aim of the study was to investigate the status of oxidative modification of proteins and glutathionedependent antioxidant defense system in adipocytes of rats with alloxan diabetes under conditions of oxidative stress.Material and methods. Development of type 1 diabetes was induced in rats by alloxan administration (90 mg/kg of body mass. Adipocytes were obtained from epididymal adipose tissue of rats. The level of carbonyl derivatives of proteins, oxidized tryptophan, bityrosine, general, reduced, oxygenated and protein-bound glutathione, as well as glutathione peroxidase activity in adipocytes of rats was determined.Results. In adipocytes of rats with alloxan diabetes, concentration of carbonyl derivatives of proteins, bityrosine and oxidized tryptophan increased on the background of redox-potential of glutathione system and glutathione peroxidase activity decrease.Conclusion. The obtained data indicate the activation of free-radical oxidation of proteins and reduction of antioxidant defense under conditions of oxidative stress in the adipose tissue of rats with alloxan diabetes; this process plays an important role in pathogenesis of diabetes and its complications development.

  5. Investigating the role of class-IA PI 3-kinase isoforms in adipocyte differentiation

    International Nuclear Information System (INIS)

    Kim, Ji Eun; Shepherd, Peter R.; Chaussade, Claire

    2009-01-01

    PI 3-kinases, in particular class-IA, are key signalling molecules controlling many cellular processes including growth, proliferation, migration and differentiation. In this study, we have used a collection of isoform selective PI 3-kinase inhibitors to determine whether attenuation of signalling through class-IA PI 3-kinase isoforms will impact adipocyte differentiation. First, we analysed the expression profiles and found that fibroblastic pre-adipocytes express detectable levels of p110α and p110δ and that after differentiation, p110δ levels fall while p110α levels rise, together with C/EBPα and PPARγ. When using specific inhibitors during the differentiation process, we observed that neither p110β nor p110δ inhibition, had any significant effect. In contrast PIK-75, a selective p110α inhibitor completely abolished adipocyte differentiation as assessed by morphology, transcript and protein levels of adipocyte markers. These results indicate that long term treatment with p110α inhibitors could potentially have a severe impact on fat cell numbers in vivo.

  6. Circulating adipocyte fatty acid-binding protein, juvenile obesity, and metabolic syndrome

    NARCIS (Netherlands)

    Krzystek-Korpacka, Malgorzata; Patryn, Eliza; Bednarz-Misa, Iwona; Mierzchala, Magdalena; Hotowy, Katarzyna; Czapinska, Elzbieta; Kustrzeba-Wojcicka, Irena; Gamian, Andrzej; Noczynska, Anna

    2011-01-01

    Adipocyte fatty acid-binding protein (A-FABP) links obesity and metabolic syndrome (MetS) and might be targeted in future therapies. Its utility as a MetS biomarker has been suggested in adults but has not been examined in children/adolescents. Our objectives were to identify metabolic parameters

  7. Adipocyte-myocyte crosstalk in skeletal muscle insulin resistance; is there a role for thyroid hormone?

    Science.gov (United States)

    Havekes, Bas; Sauerwein, Hans P

    2010-11-01

    To review original research studies and reviews that present data on adipocyte-myocyte crosstalk in the development of skeletal muscle insulin resistance with a specific focus on thyroid hormone. Adipose tissue communicates with skeletal muscle not only through free fatty acids but also through secretion of various products called adipokines. Adipokines came out as governors of insulin sensitivity and are deregulated in obesity. In addition to well known leptin, adiponectin, interleukin-6 and tumor necrosis factor-alpha, newer adipokines like retinol-binding protein 4 have been associated with insulin resistance. There is mounting evidence that not only adipose tissue but also skeletal muscle produces and secretes biologically active proteins or 'myokines' that facilitate metabolic crosstalk between organ systems. In recent years, increased expression of myostatin, a secreted anabolic inhibitor of muscle growth and development, has been associated with obesity and insulin resistance. Both hypothyroidism and hyperthyroidism affect insulin sensitivity in multiple ways that might overlap adipocyte-myocyte crosstalk. Recent studies have provided new insights in effects of processing of the parent hormone T4 to the active T3 at the level of the skeletal muscle. Adipocyte-myocyte crosstalk is an important modulator in the development of skeletal muscle insulin resistance. Thyroid disorders are very common and may have detrimental effects on skeletal muscle insulin resistance, potentially by interacting with adipocyte-myocyte crosstalk.

  8. Regulation of AMP-activated protein kinase by LKB1 and CaMKK in adipocytes

    DEFF Research Database (Denmark)

    Gormand, Amélie; Henriksson, Emma; Ström, Kristoffer

    2011-01-01

    AMP-activated protein kinase (AMPK) is a serine/threonine kinase that regulates cellular and whole body energy homeostasis. In adipose tissue, activation of AMPK has been demonstrated in response to a variety of extracellular stimuli. However, the upstream kinase that activates AMPK in adipocytes...

  9. Identification and expression patterns of adipokine genes during adipocyte differentiation in the Tibetan goat (Capra hircus).

    Science.gov (United States)

    Li, Xueying; Wang, Yan; Guo, Jiazhong; Zhong, Tao; Li, Li; Zhang, Hongping; Wang, Linjie

    2018-02-15

    Adipokines are secreted by adipose tissue and play an important role in the regulation of lipid metabolism. However, the information regarding adipokines in goats is limited. PPARγ is a key gene in adipocyte differentiation and activates adipokine genes. Rosiglitazone is a PPARγ agonist and can promote the expression of PPARγ to increase the expression of lipogenesis-related genes. Therefore, investigation of the relationship between rosiglitazone and adipokines will help us to better understand the function of PPARγ in lipid metabolism in Tibetan goats. In this study, we cloned the resistin (RETN), apelin (APLN), fibroblast growth factor 21 (FGF21), and visfatin (NAMPT) genes from non-pregnant female Tibetan goat adipose tissue. APLN and NAMPT were predominantly expressed in the kidney, and FGF21 was expressed at the highest levels in the liver in vivo. In fat tissues, the highest expression levels of FGF21 and RETN were detected in omental fat, whereas their expression in perirenal and subcutaneous fat was extremely weak. APLN and NAMPT were abundantly expressed in omental and subcutaneous fat in vivo. In addition, the four adipokines had different expression profiles during goat adipocyte differentiation in vitro. Oil red O staining showed that rosiglitazone could promote adipocyte differentiation and lipid droplet formation. In addition, rosiglitazone significantly increased the expression of FGF21 and RETN (pgoat adipocyte differentiation. And PPARγ could regulate the expression of the four adipokines, but the detailed regulatory mechanism still needs to be elucidated. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Inhibitory effect of leptin on rosiglitazone-induced differentiation of primary adipocytes prepared from TallyHO/Jng mice

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Young; Kim, Joo Young; Sung, Yoon-Young; Jung, Won Hoon; Kim, Hee-Youn; Park, Ji Seon; Cheon, Hyae Gyeong [Medicinal Science Division, Korea Research Institute of Chemical Technology, 100 Jang-dong, Yuseong, 305-600 Daejon (Korea, Republic of); Rhee, Sang Dal, E-mail: sdrhee@krict.re.kr [Medicinal Science Division, Korea Research Institute of Chemical Technology, 100 Jang-dong, Yuseong, 305-600 Daejon (Korea, Republic of)

    2011-03-25

    Research highlights: {yields} In this study, we investigated the effects of leptin on adipocyte differentiation prepared from subcutaneous fat of TallyHo mice. {yields} Leptin inhibited the adipocytes differentiation at physiological concentration via inhibition of PPAR{gamma} expression. {yields} Inhibitors of ERK and STAT1 restored the leptin's inhibitory activity both in vitro and in vivo. -- Abstract: The effects of leptin on rosiglitazone-induced adipocyte differentiation were investigated in the primary adipocytes prepared from subcutaneous fat of TallyHO/Jng (TallyHO) mouse, a recently developed model animal for type 2 diabetes mellitus (T2DM). The treatment of leptin inhibited the rosiglitazone-induced adipocyte differentiation with a decreased expression of peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) a key adipogenic transcription factor, both in mRNA and protein levels. Leptin (10 nM) was sufficient to inhibit the adipocyte differentiation, which seemed to come from increased expression of leptin receptor genes in the fat of TallyHO mice. The inhibition of adipogenesis by leptin was restored by the treatment of inhibitors for extracellular-signal-regulated kinase (ERK) (PD98059) and signal transducer and activator of transcription-1 (STAT1) (fludarabine). Furthermore, in vivo intraperitoneal administration of PD98059 and fludarabine increased the PPAR{gamma} expression in the subcutaneous fat of TallyHO mice. These data suggest that leptin could inhibit the PPAR{gamma} expression and adipocyte differentiation in its physiological concentration in TallyHO mice.

  11. Korean Curcuma longa L. induces lipolysis and regulates leptin in adipocyte cells and rats

    Science.gov (United States)

    Song, Won-Yeong

    2016-01-01

    BACKGROUND/OBJECTIVES Turmeric (Curcuma longa L.) has been reported to have many biological functions including anti-obesity. Leptin, peptide hormone produced by adipocytes and its concentration is increased in proportion to the amount of the adipocytes. In the present study, we examined the effects of Korean turmeric on the regulation of adiposity and leptin levels in 3T3-L1 adipocytes and rats fed a high-fat and high-cholesterol diet. MATERIALS/METHODS Leptin secretion, free fatty acid and glycerol contents in 3T3-L1 adipocytes were measured after incubation of cells with turmeric for 24 hours. Rats were divided into four experimental groups: a normal diet group (N), a high-fat and high-cholesterol diet group (HF), a high-fat and high-cholesterol diet group supplemented with 2.5% turmeric extracts (TPA group) and a high-fat and high-cholesterol diet group supplemented with 5% turmeric extracts (TPB group). Serum samples were used for the measurement of leptin concentration. RESULTS Contents of free fatty acid and glycerol showed concentration dependent increase in response to turmeric extracts. Effects of turmeric extracts on reduction of lipid accumulation in 3T3-L1 cells were examined by Oil Red O staining. Treatment with turmeric extracts resulted in increased expression levels of adipose triglyceride lipase and hormone-sensitive lipase mRNA. The concentration of leptin from 3T3-L1 adipocytes was significantly decreased by turmeric. Proportional abdominal and epididymal fats weights of the turmeric 5% supplemented group, TPB has significantly decreased compared to the HF group. The serum levels of leptin in the TPA and TPB groups were significantly lower than those of the HF group. CONCLUSIONS Based on these results, we suggested that Korean turmeric may contribute to the decreasing of body fat and regulating leptin secretion. PMID:27698955

  12. The adaptor protein alpha-syntrophin regulates adipocyte lipid droplet growth

    Energy Technology Data Exchange (ETDEWEB)

    Eisinger, Kristina; Rein-Fischboeck, Lisa; Pohl, Rebekka; Meier, Elisabeth M.; Krautbauer, Sabrina; Buechler, Christa, E-mail: christa.buechler@klinik.uni-regensburg.de

    2016-07-01

    The scaffold protein alpha-syntrophin (SNTA) regulates lipolysis indicating a role in lipid homeostasis. Adipocytes are the main lipid storage cells in the body, and here, the function of SNTA has been analyzed in 3T3-L1 cells. SNTA is expressed in preadipocytes and is induced early during adipogenesis. Knock-down of SNTA in preadipocytes increases their proliferation. Proteins which are induced during adipogenesis like adiponectin and caveolin-1, and the inflammatory cytokine IL-6 are at normal levels in the mature cells differentiated from preadipocytes with low SNTA. This suggests that SNTA does neither affect differentiation nor inflammation. Expression of proteins with a role in cholesterol and triglyceride homeostasis is unchanged. Consequently, basal and epinephrine induced lipolysis as well as insulin stimulated phosphorylation of Akt and ERK1/2 are normal. Importantly, adipocytes with low SNTA form smaller lipid droplets and store less triglycerides. Stearoyl-CoA reductase and MnSOD are reduced upon SNTA knock-down but do not contribute to lower lipid levels. Oleate uptake is even increased in cells with SNTA knock-down. In summary, current data show that SNTA is involved in the expansion of lipid droplets independent of adipogenesis. Enhanced preadipocyte proliferation and capacity to store surplus fatty acids may protect adipocytes with low SNTA from lipotoxicity in obesity. - Highlights: • Alpha-syntrophin (SNTA) is expressed in 3T3-L1adipocytes. • SNTA knock-down in preadipocytes has no effect on adipogenesis. • Mature 3T3-L1 differentiated from cells with low SNTA form small lipid droplets. • SCD1 and MnSOD are reduced in adipocytes with low SNTA. • SCD1 knock-down does not alter triglyceride levels.

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

    Science.gov (United States)

    Mezentseva, Nadejda V; Kumaratilake, Jaliya S; Newman, Stuart A

    2008-01-01

    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. PMID:18426587

  14. JAZF1 can regulate the expression of lipid metabolic genes and inhibit lipid accumulation in adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Guang-feng [Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan (China); Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha 410008, Hunan (China); Xiao, Di; Gong, Wei-jing [Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan (China); Liu, Hui-xia; Liu, Jun [Department of Geriatrics, Xiangya Hospital, Central South University, Changsha 410008, Hunan (China); Zhou, Hong-hao [Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan (China); Liu, Zhao-qian, E-mail: liuzhaoqian63@126.com [Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan (China)

    2014-03-14

    Highlights: • JAZF1 was significantly upregulated during the differentiation of 3T3-L1 preadipocytes. • JAZF1 overexpression inhibited lipid accumulation in differentiated mature 3T3-L1 adipocytes. • JAZF1 overexpression inhibited the expression of SREBP1, ACC, and FAS. • JAZF1 overexpression upregulated the expression of HSL and ATGL. • SREBP1 and JAZF1 could regulate each other in adipocytes. - Abstract: JAZF1 is a newly identified gene with unknown functions. A recent genome-wide association study showed that JAZF1 is associated with type 2 diabetes and is highly expressed in liver and adipose tissue. Studies have demonstrated that JAZF1 is the co-repressor for nuclear orphan receptor TAK1, whereas most nuclear orphan receptor family members are involved in the regulation of lipid metabolism. Therefore, JAZF1 could be closely related to glycolipid metabolism. In this study, JAZF1 was significantly upregulated during the induced differentiation process of 3T3-L1 preadipocytes. The overexpression of JAZF1 inhibited lipid accumulation in differentiated mature 3T3-L1 adipocytes and significantly inhibited the expression of SREBPl, ACC, and FAS, which were important in lipid synthesis, while upregulating the expression of key enzyme hormone-sensitive lipase in lipoclasis. Moreover, SREBPl exhibited an inhibitory function on the expression of JAZF1. SREBP1 reversed the inhibitory action on lipid accumulation of JAZF1. SREBP1 and JAZF1 were observed to regulate each other in adipocytes. Therefore, JAZF1 could regulate the expression of particular genes related to lipid metabolism and inhibit lipid accumulation in adipocytes. This result suggests that JAZF1 may be a potential target for the treatment of diseases, such as obesity and lipid metabolism disorders.

  15. Cellular origins of cold-induced brown adipocytes in adult mice.

    Science.gov (United States)

    Lee, Yun-Hee; Petkova, Anelia P; Konkar, Anish A; Granneman, James G

    2015-01-01

    This work investigated how cold stress induces the appearance of brown adipocytes (BAs) in brown and white adipose tissues (WATs) of adult mice. In interscapular brown adipose tissue (iBAT), cold exposure increased proliferation of endothelial cells and interstitial cells expressing platelet-derived growth factor receptor, α polypeptide (PDGFRα) by 3- to 4-fold. Surprisingly, brown adipogenesis and angiogenesis were largely restricted to the dorsal edge of iBAT. Although cold stress did not increase proliferation in inguinal white adipose tissue (ingWAT), the percentage of BAs, defined as multilocular adipocytes that express uncoupling protein 1, rose from undetectable to 30% of total adipocytes. To trace the origins of cold-induced BAs, we genetically tagged PDGFRα(+) cells and adipocytes prior to cold exposure, using Pdgfra-Cre recombinase estrogen receptor T2 fusion protein (CreER(T2)) and adiponectin-CreER(T2), respectively. In iBAT, cold stress triggered the proliferation and differentiation of PDGFRα(+) cells into BAs. In contrast, all newly observed BAs in ingWAT (5207 out of 5207) were derived from unilocular adipocytes tagged by adiponectin-CreER(T2)-mediated recombination. Surgical denervation of iBAT reduced cold-induced brown adipogenesis by >85%, whereas infusion of norepinephrine (NE) mimicked the effects of cold in warm-adapted mice. NE-induced de novo brown adipogenesis in iBAT was eliminated in mice lacking β1-adrenergic receptors. These observations identify a novel tissue niche for brown adipogenesis in iBAT and further define depot-specific mechanisms of BA recruitment. © FASEB.

  16. Characterization of actions of octanoate on porcine preadipocytes and adipocytes differentiated in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Shunichi, E-mail: shunsuzu@affrc.go.jp [Transgenic Pig Research Unit, National Institute of Agrobiological Sciences, 2 Ikenodai, Tsukuba, Ibaraki 305-0901 (Japan); Suzuki, Misae; Sembon, Shoichiro; Fuchimoto, Daiichiro; Onishi, Akira [Transgenic Pig Research Unit, National Institute of Agrobiological Sciences, 2 Ikenodai, Tsukuba, Ibaraki 305-0901 (Japan)

    2013-03-01

    Highlights: ► Octanoate regulated gene expressions in a way distinct from rosiglitasone. ► Octanoate upregulatedPPRE and LXRE reporter activities. ► Octanoate may act on some PPARγ-target genes competitively with other ligands. - Abstract: Octanoate is used to induce adipogenic differentiation and/or lipid accumulation in preadipocytes of domestic animals. However, information on detailed actions of octanoate and the characteristics of octanoate-induced adipocytes is limited. The aim of this study was to examine these issues by comparing the outcomes of the effects of octanoate with those of rosiglitazone, which is a well-defined activator of peroxisome proliferator-activated receptor (PPAR)-γ. The adipocytes that were differentiated with 5 mM of octanoate had dispersed and diversely sized lipid droplets compared to those that were differentiated with 1 μM of rosiglitazone. The gene expression levels of adiponectin, glycerol-3-phosphate dehydrogenase, perilipin 1, and perilipin 4 were much higher in the adipocytes that were differentiated with rosiglitazone than in those differentiated with octanoate, while the gene expression levels of lipoprotein lipase and perilipin 2 were decreased in rosiglitazone-differentiated adipocytes compared to octanoate-differentiated adipocytes. However, the expressions of aP2 and CD36 genes were comparably induced. Luciferase reporter assays revealed that PPAR and liver-X-receptor activities were upregulated by octanoate more effectively than by rosiglitazone. Overall, these results suggested that the action of octanoate was complicated and may be dependent on the targeted genes and cellular status.

  17. JAZF1 can regulate the expression of lipid metabolic genes and inhibit lipid accumulation in adipocytes

    International Nuclear Information System (INIS)

    Ming, Guang-feng; Xiao, Di; Gong, Wei-jing; Liu, Hui-xia; Liu, Jun; Zhou, Hong-hao; Liu, Zhao-qian

    2014-01-01

    Highlights: • JAZF1 was significantly upregulated during the differentiation of 3T3-L1 preadipocytes. • JAZF1 overexpression inhibited lipid accumulation in differentiated mature 3T3-L1 adipocytes. • JAZF1 overexpression inhibited the expression of SREBP1, ACC, and FAS. • JAZF1 overexpression upregulated the expression of HSL and ATGL. • SREBP1 and JAZF1 could regulate each other in adipocytes. - Abstract: JAZF1 is a newly identified gene with unknown functions. A recent genome-wide association study showed that JAZF1 is associated with type 2 diabetes and is highly expressed in liver and adipose tissue. Studies have demonstrated that JAZF1 is the co-repressor for nuclear orphan receptor TAK1, whereas most nuclear orphan receptor family members are involved in the regulation of lipid metabolism. Therefore, JAZF1 could be closely related to glycolipid metabolism. In this study, JAZF1 was significantly upregulated during the induced differentiation process of 3T3-L1 preadipocytes. The overexpression of JAZF1 inhibited lipid accumulation in differentiated mature 3T3-L1 adipocytes and significantly inhibited the expression of SREBPl, ACC, and FAS, which were important in lipid synthesis, while upregulating the expression of key enzyme hormone-sensitive lipase in lipoclasis. Moreover, SREBPl exhibited an inhibitory function on the expression of JAZF1. SREBP1 reversed the inhibitory action on lipid accumulation of JAZF1. SREBP1 and JAZF1 were observed to regulate each other in adipocytes. Therefore, JAZF1 could regulate the expression of particular genes related to lipid metabolism and inhibit lipid accumulation in adipocytes. This result suggests that JAZF1 may be a potential target for the treatment of diseases, such as obesity and lipid metabolism disorders

  18. Glucose availability controls adipogenesis in mouse 3T3-L1 adipocytes via up-regulation of nicotinamide metabolism.

    Science.gov (United States)

    Jackson, Robert M; Griesel, Beth A; Gurley, Jami M; Szweda, Luke I; Olson, Ann Louise

    2017-11-10

    Expansion of adipose tissue in response to a positive energy balance underlies obesity and occurs through both hypertrophy of existing cells and increased differentiation of adipocyte precursors (hyperplasia). To better understand the nutrient signals that promote adipocyte differentiation, we investigated the role of glucose availability in regulating adipocyte differentiation and maturation. 3T3-L1 preadipocytes were grown and differentiated in medium containing a standard differentiation hormone mixture and either 4 or 25 mm glucose. Adipocyte maturation at day 9 post-differentiation was determined by key adipocyte markers, including glucose transporter 4 (GLUT4) and adiponectin expression and Oil Red O staining of neutral lipids. We found that adipocyte differentiation and maturation required a pulse of 25 mm glucose only during the first 3 days of differentiation. Importantly, fatty acids were unable to substitute for the 25 mm glucose pulse during this period. The 25 mm glucose pulse increased adiponectin and GLUT4 expression and accumulation of neutral lipids via distinct mechanisms. Adiponectin expression and other early markers of differentiation required an increase in the intracellular pool of total NAD/P. In contrast, GLUT4 protein expression was only partially restored by increased NAD/P levels. Furthermore, GLUT4 mRNA expression was mediated by glucose-dependent activation of GLUT4 gene transcription through the cis-acting GLUT4-liver X receptor element (LXRE) promoter element. In summary, this study supports the conclusion that high glucose promotes adipocyte differentiation via distinct metabolic pathways and independently of fatty acids. This may partly explain the mechanism underlying adipocyte hyperplasia that occurs much later than adipocyte hypertrophy in the development of obesity. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Dose- and type-dependent effects of long-chain fatty acids on adipogenesis and lipogenesis of bovine adipocytes.

    Science.gov (United States)

    Yanting, Chen; Yang, Q Y; Ma, G L; Du, M; Harrison, J H; Block, E

    2018-02-01

    Differentiation and lipid metabolism of adipocytes have a great influence on milk performance, health, and feed efficiency of dairy cows. The effects of dietary long-chain fatty acids (FA) on adipogenesis and lipogenesis of dairy cows are often confounded by other nutritional and physiological factors in vivo. Therefore, this study used an in vitro approach to study the effect of dose and type of long-chain FA on adipogenesis and lipogenesis of bovine adipocytes. Stromal vascular cells were isolated from adipose tissue of dairy cows and induced into mature adipocytes in the presence of various long-chain FA including myristic, palmitic, stearic, oleic, or linoleic acid. When concentrations of myristic, palmitic, and oleic acids in adipogenic mediums were 150 and 200 μM, the induced mature adipocytes had greater lipid content compared with other concentrations of FA. In addition, mature adipocytes induced at 100 μM stearic acid and 300 μM linoleic acid had the greatest content of lipid than at other concentrations. High concentrations of saturated FA were more toxic for cells than the same concentration of unsaturated FA during the induction. When commitment stage was solely treated with FA, the number of differentiated mature adipocytes was greater for oleic and linoleic acids than other FA. When the maturation stage was treated with FA, the number of mature adipocytes was not affected, but the lipid content in adipocytes was affected and ranked oleic > linoleic > myristic > stearic > palmitic. In summary, this study showed that adipogenesis and lipogenesis of bovine adipocytes were differentially affected by long-chain FA, with unsaturated FA more effective than saturated FA. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. Bone marrow adipocytes resist lipolysis and remodeling in response to β-adrenergic stimulation.

    Science.gov (United States)

    Scheller, Erica L; Khandaker, Shaima; Learman, Brian S; Cawthorn, William P; Anderson, Lindsay M; Pham, H A; Robles, Hero; Wang, Zhaohua; Li, Ziru; Parlee, Sebastian D; Simon, Becky R; Mori, Hiroyuki; Bree, Adam J; Craft, Clarissa S; MacDougald, Ormond A

    2018-01-26

    Bone marrow adipose tissue (BMAT) is preserved or increased in states of caloric restriction. Similarly, we found that BMAT in the tail vertebrae, but not the red marrow in the tibia, resists loss of neutral lipid with acute, 48-hour fasting in rats. The mechanisms underlying this phenomenon and its seemingly distinct regulation from peripheral white adipose tissue (WAT) remain unknown. To test the role of β-adrenergic stimulation, a major regulator of adipose tissue lipolysis, we examined the responses of BMAT to β-adrenergic agonists. Relative to inguinal WAT, BMAT had reduced phosphorylation of hormone sensitive lipase (HSL) after treatment with pan-β-adrenergic agonist isoproterenol. Phosphorylation of HSL in response to β3-adrenergic agonist CL316,243 was decreased by an additional ~90% (distal tibia BMAT) or could not be detected (tail vertebrae). Ex vivo, adrenergic stimulation of lipolysis in purified BMAT adipocytes was also substantially less than iWAT adipocytes and had site-specific properties. Specifically, regulated bone marrow adipocytes (rBMAs) from proximal tibia and femur underwent lipolysis in response to both CL316,243 and forskolin, while constitutive BMAs from the tail responded only to forskolin. This occurred independently of changes in gene expression of β-adrenergic receptors, which were similar between adipocytes from iWAT and BMAT, and could not be explained by defective coupling of β-adrenergic receptors to lipolytic machinery through caveolin 1. Specifically, we found that whereas caveolin 1 was necessary to mediate maximal stimulation of lipolysis in iWAT, overexpression of caveolin 1 was insufficient to rescue impaired BMAT signaling. Lastly, we tested the ability of BMAT to respond to 72-hour treatment with CL316,243 in vivo. This was sufficient to cause beiging of iWAT adipocytes and a decrease in iWAT adipocyte cell size. By contrast, adipocyte size in the tail BMAT and distal tibia remained unchanged. However, within the

  1. A role for long-chain acyl-CoA synthetase-4 (ACSL4 in diet-induced phospholipid remodeling and obesity-associated adipocyte dysfunction

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Killion

    2018-03-01

    Full Text Available Objective: Regulation of fatty acid (FA metabolism is central to adipocyte dysfunction during diet-induced obesity (DIO. Long-chain acyl-CoA synthetase-4 (ACSL4 has been hypothesized to modulate the metabolic fates of polyunsaturated FA (PUFA, including arachidonic acid (AA, but the in vivo actions of ACSL4 are unknown. The purpose of our studies was to determine the in vivo role of adipocyte ACSL4 in regulating obesity-associated adipocyte dysfunction. Methods: We developed a novel mouse model with adipocyte-specific ablation of ACSL4 (Ad-KO using loxP Cre recombinase technology. Metabolic phenotyping of Ad-KO mice relative to their floxed littermates (ACSL4floxed was performed, including body weight and body composition over time; insulin and glucose tolerance tests; and energy expenditure, activity, and food intake in metabolic cages. Adipocytes were isolated for ex vivo adipocyte oxygen consumption by Clark electrode and lipidomics analysis. In vitro adipocyte analysis including oxygen consumption by Seahorse and real-time PCR analysis were performed to confirm our in vivo findings. Results: Ad-KO mice were protected against DIO, adipocyte death, and metabolic dysfunction. Adipocytes from Ad-KO mice fed high-fat diet (HFD had reduced incorporation of AA into phospholipids (PL, free AA, and levels of the AA lipid peroxidation product 4-hydroxynonenal (4-HNE. Additionally, adipocytes from Ad-KO mice fed HFD had reduced p53 activation and increased adipocyte oxygen consumption (OCR, which we demonstrated are direct effects of 4-HNE on adipocytes in vitro. Conclusion: These studies are the first to elucidate ACSL4's in vivo actions to regulate the incorporation of AA into PL and downstream effects on DIO-associated adipocyte dysfunction. By reducing the incorporation of AA into PL and free fatty acid pools in adipocytes, Ad-KO mice were significantly protected against HFD-induced increases in adipose and liver fat accumulation, adipocyte death

  2. MCT1 and MCT4 expression and lactate flux activity increase during white and brown adipogenesis and impact adipocyte metabolism

    DEFF Research Database (Denmark)

    Petersen, Charlotte; Nielsen, Mette D.; Andersen, Elise S.

    2017-01-01

    RNA and protein levels of the lactate-H+ transporter MCT1 and the Na+,HCO3 - cotransporter NBCe1 were upregulated in mouse interscapular brown and inguinal white adipose tissue upon cold induction of thermogenesis and browning. MCT1, MCT4, and NBCe1 were furthermore strongly upregulated at the mRNA and protein...... level upon differentiation of cultured pre-adipocytes. Adipocyte differentiation was accompanied by increased plasma membrane lactate flux capacity, which was reduced by MCT inhibition and by MCT1 knockdown. Finally, in differentiated brown adipocytes, glycolysis (assessed as ECAR), and after...... noradrenergic stimulation also oxidative metabolism (OCR), was decreased by MCT inhibition. We suggest that upregulation of MCT1- and MCT4-mediated lactate flux capacity and NBCe1-mediated HCO3 -/pH homeostasis are important for the physiological function of mature adipocytes....

  3. Transcriptional and epigenetic mechanisms underlying enhanced in vitro adipocyte differentiation by the brominated flame retardant BDE-47

    DEFF Research Database (Denmark)

    Kamstra, Jorke H; Hruba, Eva; Blumberg, Bruce

    2014-01-01

    Recent studies suggest that exposure to endocrine-disrupting compounds (EDCs) may play a role in the development of obesity. EDCs such as the flame retardant 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) have been shown to enhance adipocyte differentiation in the murine 3T3-L1 model. The mech......Recent studies suggest that exposure to endocrine-disrupting compounds (EDCs) may play a role in the development of obesity. EDCs such as the flame retardant 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) have been shown to enhance adipocyte differentiation in the murine 3T3-L1 model....... The mechanisms by which EDCs direct preadipocytes to form adipocytes are poorly understood. Here, we examined transcriptional and epigenetic mechanisms underlying the induction of in vitro adipocyte differentiation by BDE-47. Quantitative high content microscopy revealed concentration-dependent enhanced...

  4. Peroxisome Proliferator-Activated Receptor (PPAR) in Regenerative Medicine: Molecular Mechanism for PPAR in Stem Cells' Adipocyte Differentiation.

    Science.gov (United States)

    Xie, Qiang; Tian, Taoran; Chen, Zhaozhao; Deng, Shuwen; Sun, Ke; Xie, Jing; Cai, Xiaoxiao

    2016-01-01

    Regenerative medicine plays an indispensable role in modern medicine and many trials and researches have therefore been developed to fit our medical needs. Tissue engineering has proven that adipose tissue can widely be used and brings advantages to regenerative medicine. Moreover, a trait of adipose stem cells being isolated and grown in vitro is a cornerstone to various applications. Since the adipose tissue has been widely used in regenerative medicine, numerous studies have been conducted to seek methods for gaining more adipocytes. To investigate molecular mechanism for adipocyte differentiation, peroxisome proliferator-activated receptor (PPAR) has been widely studied to find out its functional mechanism, as a key factor for adipocyte differentiation. However, the precise molecular mechanism is still unknown. This review thus summarizes recent progress on the study of molecular mechanism and role of PPAR in adipocyte differentiation.

  5. Xenobiotics that affect oxidative phosphorylation alter differentiation of human adipose-derived stem cells at concentrations that are found in human blood

    Directory of Open Access Journals (Sweden)

    Laura Llobet

    2015-11-01

    Full Text Available Adipogenesis is accompanied by differentiation of adipose tissue-derived stem cells to adipocytes. As part of this differentiation, biogenesis of the oxidative phosphorylation system occurs. Many chemical compounds used in medicine, agriculture or other human activities affect oxidative phosphorylation function. Therefore, these xenobiotics could alter adipogenesis. We have analyzed the effects on adipocyte differentiation of some xenobiotics that act on the oxidative phosphorylation system. The tested concentrations have been previously reported in human blood. Our results show that pharmaceutical drugs that decrease mitochondrial DNA replication, such as nucleoside reverse transcriptase inhibitors, or inhibitors of mitochondrial protein synthesis, such as ribosomal antibiotics, diminish adipocyte differentiation and leptin secretion. By contrast, the environmental chemical pollutant tributyltin chloride, which inhibits the ATP synthase of the oxidative phosphorylation system, can promote adipocyte differentiation and leptin secretion, leading to obesity and metabolic syndrome as postulated by the obesogen hypothesis.

  6. Confocal fluorescence microscopy to evaluate changes in adipocytes in the tumor microenvironment associated with invasive ductal carcinoma and ductal carcinoma in situ.

    Science.gov (United States)

    Dobbs, Jessica L; Shin, Dongsuk; Krishnamurthy, Savitri; Kuerer, Henry; Yang, Wei; Richards-Kortum, Rebecca

    2016-09-01

    Adipose tissue is a dynamic organ that provides endocrine, inflammatory and angiogenic factors, which can assist breast carcinoma cells with invasion and metastasis. Previous studies have shown that adipocytes adjacent to carcinoma, known as cancer-associated adipocytes, undergo extensive changes that correspond to an "activated phenotype," such as reduced size relative to adipocytes in non-neoplastic breast tissue. Optical imaging provides a tool that can be used to characterize adipocyte morphology and other features of the tumor microenvironment. In this study, we used confocal fluorescence microscopy to acquire images of freshly excised breast tissue stained topically with proflavine. We developed a computerized algorithm to identify and quantitatively measure phenotypic properties of adipocytes located adjacent to and far from normal collagen, ductal carcinoma in situ and invasive ductal carcinoma. Adipocytes were measured in confocal fluorescence images of fresh breast tissue collected from 22 patients. Results show that adipocytes adjacent to neoplastic tissue margins have significantly smaller area compared to adipocytes far from the margins of neoplastic lesions and compared to adipocytes adjacent to non-neoplastic collagenous stroma. These findings suggest that confocal microscopic images can be utilized to evaluate phenotypic properties of adipocytes in breast stroma which may be useful in defining alterations in microenvironment that may aid in the development and progression of neoplastic lesions. © 2016 UICC.

  7. Cold Exposure Induces Proliferation of Mature Brown Adipocyte in a ß3-Adrenergic Receptor-Mediated Pathway.

    Science.gov (United States)

    Fukano, Keigo; Okamatsu-Ogura, Yuko; Tsubota, Ayumi; Nio-Kobayashi, Junko; Kimura, Kazuhiro

    2016-01-01

    Hyperplasia of brown adipose tissue (BAT) is a fundamental mechanism for adaptation to survive in the cold environment in rodents. To determine which cell types comprising BAT contribute to tissue hyperplasia, immunohistochemical analysis using a proliferative marker Ki67 was performed on the BAT from 6-week-old C57BL/6J mice housed at 23°C (control) or 10°C (cold) for 5 days. Interestingly, in the control group, the cell proliferative marker Ki67 was detected in the nuclei of uncoupling protein 1-positive mature brown adipocytes (7.2% ± 0.4% of brown adipocyte), as well as in the non-adipocyte stromal-vascular (SV) cells (19.6% ± 2.3% of SV cells), which include preadiopocytes. The percentage of Ki67-positive brown adipocytes increased to 25.6% ± 1.8% at Day 1 after cold exposure and was significantly higher than the non-cold acclimated control until Day 5 (21.8% ± 1.7%). On the other hand, the percentage of Ki67-positive SV cells gradually increased by a cold exposure and peaked to 42.1% ± 8.3% at Day 5. Injection of a ß3-adrenergic receptor (ß3-AR) agonist for continuous 5 days increased the number of Ki67-positive brown adipocytes even at Day 1 but not that of SV cells. In addition, the ß3-AR antagonist, but not ß1-AR antagonist, attenuated the cold exposure-induced increase in the number of Ki67-positive brown adipocytes. These results suggest that mature brown adipocytes proliferate immediately after cold exposure in a ß3-AR-mediated pathway. Thus, proliferation of mature brown adipocytes as well as preadipocytes in SV cells may contribute to cold exposure-induced BAT hyperplasia.

  8. The effects of Bee Venom and Sweet Bee Venom to the preadipocyte proliferation and lipolysis of adipocyte, localized fat accumulation

    OpenAIRE

    Min-Ki Kim; Si Hyeong, Lee; Jo Young Shin; Kang San Kim; Nam Guen Cho; Ki Rok Kwon; Tae Jin Rhim

    2007-01-01

    Objectives : The purpose of this study was to investigate the effects of Bee Venom and Sweet Bee Venom to the primary cultured preadipocyte, adipocytes, and localized fat tissue. Methods : Decreased preadipocyte proliferation and decreased lipogenesis are mechanisms to reduce obesity. So, preadipocytes and adipocytes were performed on cell cultures using Sprague-Dawley Rats and treated with 0.01-1mg/㎖ Bee Venom and Sweet Bee Venom. And porcine skin including fat tissue after treated Bee Ve...

  9. CD1d-mediated presentation of endogenous lipid antigens by adipocytes requires microsomal triglyceride transfer protein (MTP)

    DEFF Research Database (Denmark)

    Rakhshandehroo, Maryam; Gijzel, Sanne M W; Siersbæk, Rasmus

    2014-01-01

    -dependent fashion, but little is known about the lipid antigen presentation machinery in adipocytes. Here we show that CD1d, as well as the lipid antigen loading machinery genes pro-saposin (Psap), Niemann Pick type C2 (Npc2), α-galactosidase (Gla), are upregulated in early adipogenesis, and are transcriptionally...... presenting cells (APCs), which may present an important aspect of adipocyte-immune cell communication in the regulation of whole body energy metabolism and immune homeostasis....

  10. Suppression of lipin-1 expression increases monocyte chemoattractant protein-1 expression in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Nobuhiko, E-mail: ntkhs@hoku-iryo-u.ac.jp [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510 (Japan); Yoshizaki, Takayuki [Innovation Center, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065 (Japan); Hiranaka, Natsumi; Suzuki, Takeshi [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Yui, Tomoo; Akanuma, Masayasu; Oka, Kazuya [Department of Fixed Prosthodontics and Oral Implantology, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Kanazawa, Kaoru [Department of Dental Anesthesiology, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Yoshida, Mika; Naito, Sumiyoshi [Department of Clinical Laboratory, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Fujiya, Mikihiro; Kohgo, Yutaka [Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510 (Japan); Ieko, Masahiro [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan)

    2011-11-11

    Highlights: Black-Right-Pointing-Pointer Lipin-1 affects lipid metabolism, adipocyte differentiation, and transcription. Black-Right-Pointing-Pointer Adipose lipin-1 expression is reduced in obesity. Black-Right-Pointing-Pointer Lipin-1 depletion using siRNA in 3T3-L1 adipocytes increased MCP-1 expression. Black-Right-Pointing-Pointer Lipin-1 is involved in adipose inflammation. -- Abstract: Lipin-1 plays a crucial role in the regulation of lipid metabolism and cell differentiation in adipocytes. Expression of adipose lipin-1 is reduced in obesity, and metabolic syndrome. However, the significance of this reduction remains unclear. This study investigated if and how reduced lipin-1 expression affected metabolism. We assessed mRNA expression levels of various genes related to adipocyte metabolism in lipin-1-depleted 3T3-L1 adipocytes by introducing its specific small interfering RNA. In lipin-1-depleted adipocytes, mRNA and protein expression levels of monocyte chemoattractant protein-1 (MCP-1) were significantly increased, although the other genes tested were not altered. The conditioned media from the cells promoted monocyte chemotaxis. The increase in MCP-1 expression was prevented by treatment with quinazoline or salicylate, inhibitors of nuclear factor-{kappa}B activation. Because MCP-1 is related to adipose inflammation and systemic insulin resistance, these results suggest that a reduction in adipose lipin-1 in obesity may exacerbate adipose inflammation and metabolism.

  11. Body fat mass and the proportion of very large adipocytes in pregnant women are associated with gestational insulin resistance.

    Science.gov (United States)

    Svensson, H; Wetterling, L; Bosaeus, M; Odén, B; Odén, A; Jennische, E; Edén, S; Holmäng, A; Lönn, M

    2016-04-01

    Pregnancy is accompanied by fat gain and insulin resistance. Changes in adipose tissue morphology and function during pregnancy and factors contributing to gestational insulin resistance are incompletely known. We sought to characterize adipose tissue in trimesters 1 and 3 (T1/T3) in normal weight (NW) and obese pregnant women, and identify adipose tissue-related factors associated with gestational insulin resistance. Twenty-two NW and 11 obese women were recruited early in pregnancy for the Pregnancy Obesity Nutrition and Child Health study. Examinations and sampling of blood and abdominal adipose tissue were performed longitudinally in T1/T3 to determine fat mass (air-displacement plethysmography); insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR); size, number and lipolytic activity of adipocytes; and adipokine release and density of immune cells and blood vessels in adipose tissue. Fat mass and HOMA-IR increased similarly between T1 and T3 in the groups; all remained normoglycemic. Adipocyte size increased in NW women. Adipocyte number was not influenced, but proportions of small and large adipocytes changed oppositely in the groups. Lipolytic activity and circulating adipocyte fatty acid-binding protein increased in both groups. Adiponectin release was reduced in NW women. Fat mass and the proportion of very large adipocytes were most strongly associated with T3 HOMA-IR by multivariable linear regression (R(2)=0.751, Pinsulin resistance.

  12. Suppression of lipin-1 expression increases monocyte chemoattractant protein-1 expression in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Takahashi, Nobuhiko; Yoshizaki, Takayuki; Hiranaka, Natsumi; Suzuki, Takeshi; Yui, Tomoo; Akanuma, Masayasu; Oka, Kazuya; Kanazawa, Kaoru; Yoshida, Mika; Naito, Sumiyoshi; Fujiya, Mikihiro; Kohgo, Yutaka; Ieko, Masahiro

    2011-01-01

    Highlights: ► Lipin-1 affects lipid metabolism, adipocyte differentiation, and transcription. ► Adipose lipin-1 expression is reduced in obesity. ► Lipin-1 depletion using siRNA in 3T3-L1 adipocytes increased MCP-1 expression. ► Lipin-1 is involved in adipose inflammation. -- Abstract: Lipin-1 plays a crucial role in the regulation of lipid metabolism and cell differentiation in adipocytes. Expression of adipose lipin-1 is reduced in obesity, and metabolic syndrome. However, the significance of this reduction remains unclear. This study investigated if and how reduced lipin-1 expression affected metabolism. We assessed mRNA expression levels of various genes related to adipocyte metabolism in lipin-1-depleted 3T3-L1 adipocytes by introducing its specific small interfering RNA. In lipin-1-depleted adipocytes, mRNA and protein expression levels of monocyte chemoattractant protein-1 (MCP-1) were significantly increased, although the other genes tested were not altered. The conditioned media from the cells promoted monocyte chemotaxis. The increase in MCP-1 expression was prevented by treatment with quinazoline or salicylate, inhibitors of nuclear factor-κB activation. Because MCP-1 is related to adipose inflammation and systemic insulin resistance, these results suggest that a reduction in adipose lipin-1 in obesity may exacerbate adipose inflammation and metabolism.

  13. Adipocyte Glucocorticoid Receptor Deficiency Attenuates Aging- and HFD-Induced Obesity and Impairs the Feeding-Fasting Transition.

    Science.gov (United States)

    Mueller, Kristina M; Hartmann, Kerstin; Kaltenecker, Doris; Vettorazzi, Sabine; Bauer, Mandy; Mauser, Lea; Amann, Sabine; Jall, Sigrid; Fischer, Katrin; Esterbauer, Harald; Müller, Timo D; Tschöp, Matthias H; Magnes, Christoph; Haybaeck, Johannes; Scherer, Thomas; Bordag, Natalie; Tuckermann, Jan P; Moriggl, Richard

    2017-02-01

    Glucocorticoids (GCs) are important regulators of systemic energy metabolism, and aberrant GC action is linked to metabolic dysfunctions. Yet, the extent to which normal and pathophysiological energy metabolism depend on the GC receptor (GR) in adipocytes remains unclear. Here, we demonstrate that adipocyte GR deficiency in mice significantly impacts systemic metabolism in different energetic states. Plasma metabolomics and biochemical analyses revealed a marked global effect of GR deficiency on systemic metabolite abundance and, thus, substrate partitioning in fed and fasted states. This correlated with a decreased lipolytic capacity of GR-deficient adipocytes under postabsorptive and fasting conditions, resulting from impaired signal transduction from β-adrenergic receptors to adenylate cyclase. Upon prolonged fasting, the impaired lipolytic response resulted in abnormal substrate utilization and lean mass wasting. Conversely, GR deficiency attenuated aging-/diet-associated obesity, adipocyte hypertrophy, and liver steatosis. Systemic glucose tolerance was improved in obese GR-deficient mice, which was associated with increased insulin signaling in muscle and adipose tissue. We conclude that the GR in adipocytes exerts central but diverging roles in the regulation of metabolic homeostasis depending on the energetic state. The adipocyte GR is indispensable for the feeding-fasting transition but also promotes adiposity and associated metabolic disorders in fat-fed and aged mice. © 2017 by the American Diabetes Association.

  14. Leptin Production by Encapsulated Adipocytes Increases Brown Fat, Decreases Resistin, and Improves Glucose Intolerance in Obese Mice.

    Directory of Open Access Journals (Sweden)

    David J DiSilvestro

    Full Text Available The neuroendocrine effects of leptin on metabolism hold promise to be translated into a complementary therapy to traditional insulin therapy for diabetes and obesity. However, injections of leptin can provoke inflammation. We tested the effects of leptin, produced in the physiological adipocyte location, on metabolism in mouse models of genetic and dietary obesity. We generated 3T3-L1 adipocytes constitutively secreting leptin and encapsulated them in a poly-L-lysine membrane, which protects the cells from immune rejection. Ob/ob mice (OB were injected with capsules containing no cells (empty, OB[Emp], adipocytes (OB[3T3], or adipocytes overexpressing leptin (OB[Lep] into both visceral fat depots. Leptin was found in the plasma of OB[Lep], but not OB[Emp] and OB[3T3] mice at the end of treatment (72 days. The OB[Lep] and OB[3T3] mice have transiently suppressed appetite and weight loss compared to OB[Emp]. Only OB[Lep] mice have greater brown fat mass, metabolic rate, and reduced resistin plasma levels compared to OB[Emp]. Glucose tolerance was markedly better in OB[Lep] vs. OB[Emp] and OB[3T3] mice as well as in wild type mice with high-fat diet-induced obesity and insulin resistance treated with encapsulated leptin-producing adipocytes. Our proof-of-principle study provides evidence of long-term improvement of glucose tolerance with encapsulated adipocytes producing leptin.

  15. PAM, OLA, and LNA are Differentially Taken Up and Trafficked Via Different Metabolic Pathways in Porcine Adipocytes.

    Science.gov (United States)

    Yu, Caihua; Xi, Lingling; Chen, Jin; Jiang, Qin; Yi, Hongbo; Wang, Yizhen; Wang, Xinxia

    2017-11-01

    Dietary fatty acids have different effects on fat deposition in pigs. To clarify the underlying mechanisms of this difference, we compared the metabolism of palmitic (PAM, saturated), oleic (OLA, monounsaturated) and linoleic acid (LNA, polyunsaturated) in porcine adipocytes treated with 100 μM PAM, OLA or LNA. We observed that the adipocytes incubated with LNA accumulated more lipids compared with those treated with PAM and OLA. We then probed the metabolism of these fatty acids in porcine adipocytes by using isotope-labelled fatty acids. The results showed that 42% of the [1- 14 C] LNA, 34% of the [1- 14 C] PAM and 28% of the [1- 14 C] OLA were recovered in the cellular lipids. The gene expression analyses showed that LNA significantly increased the expression of adipogenesis- and oxidation-related genes including PPARγ, C/EBPα, ap2 and NRF1. In addition, the cells incubated with LNA showed a decreased Ser 112 phosphorylation in PPARγ compared to those incubated with PAM and OLA. Furthermore, when PPARγ Ser 112 phosphorylation was inhibited, no significant difference in the triacylglycerol contents in the adipocytes was observed. These results showed the dietary fatty acids had different metabolism pathways in porcine adipocytes, and LNA significantly promoted lipid accumulation, probably by regulating PPARγ phosphorylation in adipocytes.

  16. Colloidal gold-labeled insulin complex. Characterization and binding to adipocytes.

    Science.gov (United States)

    Moll, U M; Thun, C; Pfeiffer, E F

    1986-01-01

    Biologically active insulin gold complex was used as an ultrastructural marker to study insulin binding sites, uptake, and internalization in isolated rat adipocytes. The preparation conditions for monodispersed particles, ca. 16 nm in diameter and loaded with approximately 100 insulin molecules, are reported. The complex is stable for at least six weeks. Single particles or small clusters were scattered across the cell membrane. The distribution of unbound receptors seemed to be independent of the extensive system of pre-existing surface connected vesicles in adipocytes. The uptake of particles took place predominantly via non-coated pinocytotic invaginations; clathrin-coated pits did not seem to be important for this process. Lysosome-like structures contained aggregates of 10-15 particles. These data suggest that insulin gold complex is a useful marker for the specific labeling of insulin binding sites.

  17. Intrinsic differences in adipocyte precursor cells from different white fat depots

    DEFF Research Database (Denmark)

    Macotela, Yazmín; Emanuelli, Brice; Mori, Marcelo A

    2012-01-01

    Obesity and body fat distribution are important risk factors for the development of type 2 diabetes and metabolic syndrome. Evidence has accumulated that this risk is related to intrinsic differences in behavior of adipocytes in different fat depots. In the current study, we demonstrate...... that adipocyte precursor cells (APCs) isolated from visceral and subcutaneous white adipose depots of mice have distinct patterns of gene expression, differentiation potential, and response to environmental and genetic influences. APCs derived from subcutaneous fat differentiate well in the presence of classical...... induction cocktail, whereas those from visceral fat differentiate poorly but can be induced to differentiate by addition of bone morphogenetic protein (BMP)-2 or BMP-4. This difference correlates with major differences in gene expression signature between subcutaneous and visceral APCs. The number of APCs...

  18. Regulation of lipolytic activity by long-chain acyl-coenzyme A in islets and adipocytes

    DEFF Research Database (Denmark)

    Hu, Liping; Deeney, Jude T; Nolan, Christopher J

    2005-01-01

    -cells. The mechanisms by which lipolysis is regulated in different tissues is, therefore, of considerable interest. Here, the effects of long-chain acyl-CoA esters (LC-CoA) on lipase activity in islets and adipocytes were compared. Palmitoyl-CoA (Pal-CoA, 1-10 microM) stimulated lipase activity in islets from both....... The inhibitory effect of LC-CoA on adipocyte HSL was dependent on phosphorylation and enhanced by acyl-CoA-binding protein (ACBP). In contrast, the stimulatory effect on islet lipase activity was blocked by ACBP, presumably due to binding and sequestration of LC-CoA. These data suggest the following intertissue...

  19. Averrhoa carambola L. peel extract suppresses adipocyte differentiation in 3T3-L1 cells.

    Science.gov (United States)

    Rashid, Asyifah Mohamed; Lu, Kaihui; Yip, Yew Mun; Zhang, Dawei

    2016-02-01

    Obesity is associated with an increased risk of many chronic diseases. Recently, a growing body of evidence has shown that phytochemicals may inhibit adipogenesis and obesity. In this study, we report for the first time, the ability of Averrhoa carambola L. peel extract commonly known as star fruit (SFP) to effectively suppress adipocyte differentiation in 3T3-L1 preadipocytes and therefore, address it as a potential candidate to treat obesity and its related diseases. (-)-Epicatechin was identified as a bioactive compound likely responsible for this suppression. As the genetic expression studies revealed that the adipogenic activity of SFP extract was due to the simultaneous downregulation of the C/EBPα and PPARγ as well as the upregulation of PPARα receptor genes, a detailed computational docking study was also elucidated to reveal the likely binding mode of (-)-epicatechin to the receptor of interest, accounting for the likely mechanism that results in the overall suppression of adipocyte differentiation.

  20. Oxidative Stress and Adipocyte Biology: Focus on the Role of AGEs

    Directory of Open Access Journals (Sweden)

    Florence Boyer

    2015-01-01

    Full Text Available Diabetes is a major health problem that is usually associated with obesity, together with hyperglycemia and increased advanced glycation endproducts (AGEs formation. Elevated AGEs elicit severe downstream consequences via their binding to receptors of AGEs (RAGE. This includes oxidative stress and oxidative modifications of biological compounds together with heightened inflammation. For example, albumin (major circulating protein undergoes increased glycoxidation with diabetes and may represent an important biomarker for monitoring diabetic pathophysiology. Despite the central role of adipose tissue in many physiologic/pathologic processes, recognition of the effects of greater AGEs formation in this tissue is quite recent within the obesity/diabetes context. This review provides a brief background of AGEs formation and adipose tissue biology and thereafter discusses the impact of AGEs-adipocyte interactions in pathology progression. Novel data are included showing how AGEs (especially glycated albumin may be involved in hyperglycemia-induced oxidative damage in adipocytes and its potential links to diabetes progression.

  1. Insulin like growth factor-1/insulin bypasses Pref-1/FA1-mediated inhibition of adipocyte differentiation

    DEFF Research Database (Denmark)

    Zhang, Hongbin; Nøhr, Jane; Jensen, Charlotte Harken

    2003-01-01

    that forced expression of the soluble form, FA1, or full-length Pref-1 did not inhibit adipocyte differentiation of 3T3-L1 cells when differentiation was induced by standard treatment with methylisobutylxanthine, dexamethasone, and high concentrations of insulin. However, forced expression of either form...... of Pref-1/FA1 in 3T3-L1 or 3T3-F442A cells inhibited adipocyte differentiation when insulin or insulin-like growth factor-1 (IGF-1) was omitted from the differentiation mixture. We demonstrate that the level of the mature form of the IGF-1 receptor is reduced and that IGF-1-dependent activation of p42/p44...... mitogen-activated protein kinases (MAPKs) is compromised in preadipocytes with forced expression of Pref-1. This is accompanied by suppression of clonal expansion and terminal differentiation. Accordingly, supplementation with insulin or IGF-1 rescued p42/p44 MAPK activation, clonal expansion...

  2. Inflammation and ER Stress Regulate Branched-Chain Amino Acid Uptake and Metabolism in Adipocytes

    Science.gov (United States)

    Burrill, Joel S.; Long, Eric K.; Reilly, Brian; Deng, Yingfeng; Armitage, Ian M.; Scherer, Philipp E.

    2015-01-01

    Inflammation plays a critical role in the pathology of obesity-linked insulin resistance and is mechanistically linked to the effects of macrophage-derived cytokines on adipocyte energy metabolism, particularly that of the mitochondrial branched-chain amino acid (BCAA) and tricarboxylic acid (TCA) pathways. To address the role of inflammation on energy metabolism in adipocytes, we used high fat-fed C57BL/6J mice and lean controls and measured the down-regulation of genes linked to BCAA and TCA cycle metabolism selectively in visceral but not in subcutaneous adipose tissue, brown fat, liver, or muscle. Using 3T3-L1 cells, TNFα, and other proinflammatory cytokine treatments reduced the expression of the genes linked to BCAA transport and oxidation. Consistent with this, [14C]-leucine uptake and conversion to triglycerides was markedly attenuated in TNFα-treated adipocytes, whereas the conversion to protein was relatively unaffected. Because inflammatory cytokines lead to the induction of endoplasmic reticulum stress, we evaluated the effects of tunicamycin or thapsigargin treatment of 3T3-L1 cells and measured a similar down-regulation in the BCAA/TCA cycle pathway. Moreover, transgenic mice overexpressing X-box binding protein 1 in adipocytes similarly down-regulated genes of BCAA and TCA metabolism in vivo. These results indicate that inflammation and endoplasmic reticulum stress attenuate lipogenesis in visceral adipose depots by down-regulating the BCAA/TCA metabolism pathway and are consistent with a model whereby the accumulation of serum BCAA in the obese insulin-resistant state is linked to adipose inflammation. PMID:25635940

  3. Insulin stimulation of phospholipid methylation in isolated rat adipocyte plasma membranes.

    OpenAIRE

    Kelly, K L; Kiechle, F L; Jarett, L

    1984-01-01

    Partially purified plasma membranes prepared from rat adipocytes contain N-methyltransferase(s) that utilize(s) S-adenosyl-L-methionine to synthesize phosphatidylcholine from phosphatidylethanolamine. The incorporation of [3H]methyl from S-adenosyl-L-[methyl-3H]methionine into plasma membrane phospholipids was linear with incubation time and plasma membrane protein concentration and was inhibited in a dose-dependent manner by both S-adenosyl-L-homocysteine and 3-deazadenosine. The addition of...

  4. The amine oxidase inhibitor phenelzine limits lipogenesis in adipocytes without inhibiting insulin action on glucose uptake.

    Science.gov (United States)

    Carpéné, Christian; Grès, Sandra; Rascalou, Simon

    2013-06-01

    The antidepressant phenelzine is a monoamine oxidase inhibitor known to inhibit various other enzymes, among them semicarbazide-sensitive amine oxidase (currently named primary amine oxidase: SSAO/PrAO), absent from neurones but abundant in adipocytes. It has been reported that phenelzine inhibits adipocyte differentiation of cultured preadipocytes. To further explore the involved mechanisms, our aim was to study in vitro the acute effects of phenelzine on de novo lipogenesis in mature fat cells. Therefore, glucose uptake and incorporation into lipid were measured in mouse adipocytes in response to phenelzine, other hydrazine-based SSAO/PrAO-inhibitors, and reference agents. None of the inhibitors was able to impair the sevenfold activation of 2-deoxyglucose uptake induced by insulin. Phenelzine did not hamper the effect of lower doses of insulin. However, insulin-stimulated glucose incorporation into lipids was dose-dependently inhibited by phenelzine and pentamidine, but not by semicarbazide or BTT2052. In contrast, all these SSAO/PrAO inhibitors abolished the transport and lipogenesis stimulation induced by benzylamine. These data indicate that phenelzine does not inhibit glucose transport, the first step of lipogenesis, but inhibits at 100 μM the intracellular triacylglycerol assembly, consistently with its long-term anti-adipogenic effect and such rapid action was not found with all the hydrazine derivatives tested. Therefore, the alterations of body weight control consecutive to the use of this antidepressant drug might be not only related to central effects on food intake/energy expenditure, but could also depend on its direct action in adipocytes. Nonetheless, phenelzine antilipogenic action is not merely dependent on SSAO/PrAO inhibition.

  5. Go-6976 Reverses Hyperglycemia-Induced Insulin Resistance Independently of cPKC Inhibition in Adipocytes

    Science.gov (United States)

    Robinson, Katherine A.; Hegyi, Krisztina; Hannun, Yusuf A.; Buse, Maria G.; Sethi, Jaswinder K.

    2014-01-01

    Chronic hyperglycemia induces insulin resistance by mechanisms that are incompletely understood. One model of hyperglycemia-induced insulin resistance involves chronic preincubation of adipocytes in the presence of high glucose and low insulin concentrations. We have previously shown that the mTOR complex 1 (mTORC1) plays a partial role in the development of insulin resistance in this model. Here, we demonstrate that treatment with Go-6976, a widely used “specific” inhibitor of cPKCs, alleviates hyperglycemia-induced insulin resistance. However, the effects of mTOR inhibitor, rapamycin and Go-6976 were not additive and only rapamycin restored impaired insulin-stimulated AKT activation. Although, PKCα, (but not –β) was abundantly expressed in these adipocytes, our studies indicate cPKCs do not play a major role in causing insulin-resistance in this model. There was no evidence of changes in the expression or phosphorylation of PKCα, and PKCα knock-down did not prevent the reduction of insulin-stimulated glucose transport. This was also consistent with lack of IRS-1 phosphorylation on Ser-24 in hyperglycemia-induced insulin-resistant adipocytes. Treatment with Go-6976 did inhibit a component of the mTORC1 pathway, as evidenced by decreased phosphorylation of S6 ribosomal protein. Raptor knock-down enhanced the effect of insulin on glucose transport in insulin resistant adipocytes. Go-6976 had the same effect in control cells, but was ineffective in cells with Raptor knock-down. Taken together these findings suggest that Go-6976 exerts its effect in alleviating hyperglycemia-induced insulin-resistance independently of cPKC inhibition and may target components of the mTORC1 signaling pathway. PMID:25330241

  6. Chilean Native Fruit Extracts Inhibit Inflammation Linked to the Pathogenic Interaction Between Adipocytes and Macrophages

    Science.gov (United States)

    Reyes-Farias, Marjorie; Vasquez, Karla; Ovalle-Marin, Angelica; Fuentes, Francisco; Parra, Claudia; Quitral, Vilma; Jimenez, Paula

    2015-01-01

    Abstract Obesity is characterized by an increase in the infiltration of monocytes into the adipose tissue, causing an inflammatory condition associated with, for example, the development of insulin resistance. Thus, anti-inflammatory-based treatments could emerge as a novel and interesting approach. It has been reported that Chilean native fruits maqui (Aristotelia chilensis) and calafate (Berberis microphylla) present high contents of polyphenols, which are known for their antioxidant and anti-inflammatory properties. The aim of this study was to evaluate the ability of extracts of these fruits to block the pathogenic interaction between adipocytes and macrophages in vitro and to compare its effect with blueberry (Vaccinium corymbosum) extract treatment, which has been already described to possess several biomedical benefits. RAW264.7 macrophages were treated with 5 μg/mL lipopolysaccharides (LPS), with conditioned media (CM) from fully differentiated 3T3-L1 adipocytes, or in a coculture (CC) with 3T3-L1 adipocytes, in the presence or absence of 100 μM [total polyphenolic content] of each extract for 24 h. The gene expression and secretion profile of several inflammatory markers were evaluated. Nitric oxide secretion induced by LPS, CM, and CC was reduced by the presence of maqui (−12.2%, −45.6%, and −14.7%, respectively) and calafate (−27.6%, −43.9%, and −11.8%, respectively) extracts. Gene expression of inducible nitric oxide synthase and TNF-α was inhibited and of IL-10 was induced by maqui and calafate extract incubation. In conclusion, the extracts of these fruits present important inhibitory-like features over the inflammatory response of the interaction between adipocytes and macrophages, comprising a potential therapeutic tool against comorbidities associated with obesity development. PMID:25302660

  7. Chilean native fruit extracts inhibit inflammation linked to the pathogenic interaction between adipocytes and macrophages.

    Science.gov (United States)

    Reyes-Farias, Marjorie; Vasquez, Karla; Ovalle-Marin, Angelica; Fuentes, Francisco; Parra, Claudia; Quitral, Vilma; Jimenez, Paula; Garcia-Diaz, Diego F

    2015-05-01

    Obesity is characterized by an increase in the infiltration of monocytes into the adipose tissue, causing an inflammatory condition associated with, for example, the development of insulin resistance. Thus, anti-inflammatory-based treatments could emerge as a novel and interesting approach. It has been reported that Chilean native fruits maqui (Aristotelia chilensis) and calafate (Berberis microphylla) present high contents of polyphenols, which are known for their antioxidant and anti-inflammatory properties. The aim of this study was to evaluate the ability of extracts of these fruits to block the pathogenic interaction between adipocytes and macrophages in vitro and to compare its effect with blueberry (Vaccinium corymbosum) extract treatment, which has been already described to possess several biomedical benefits. RAW264.7 macrophages were treated with 5 μg/mL lipopolysaccharides (LPS), with conditioned media (CM) from fully differentiated 3T3-L1 adipocytes, or in a coculture (CC) with 3T3-L1 adipocytes, in the presence or absence of 100 μM [total polyphenolic content] of each extract for 24 h. The gene expression and secretion profile of several inflammatory markers were evaluated. Nitric oxide secretion induced by LPS, CM, and CC was reduced by the presence of maqui (-12.2%, -45.6%, and -14.7%, respectively) and calafate (-27.6%, -43.9%, and -11.8%, respectively) extracts. Gene expression of inducible nitric oxide synthase and TNF-α was inhibited and of IL-10 was induced by maqui and calafate extract incubation. In conclusion, the extracts of these fruits present important inhibitory-like features over the inflammatory response of the interaction between adipocytes and macrophages, comprising a potential therapeutic tool against comorbidities associated with obesity development.

  8. Effect of vildagliptin and pravastatin combination on cholesterol efflux in adipocytes.

    Science.gov (United States)

    Mostafa, Ahmed M; Hamdy, Nadia M; Abdel-Rahman, Sherif Z; El-Mesallamy, Hala O

    2016-07-01

    Many reports suggested that some statins are almost ineffective in reducing triglycerides or enhancing HDL-C plasma levels, although statin treatment was still efficacious in reducing LDL-C. In diabetic dyslipidemic patients, it may therefore be necessary to use a combination therapy with other drugs to achieve either LDL-C- and triglyceride-lowering or HDL-C-enhancing goals. Such ineffectiveness of statins can be attributed to their effect on the liver X receptor (LXR) which regulates the expression of the ATP-binding cassette (ABC) transporters ABCA1 and ABCG1. A decrease in the expression of these transporters eventually leads to decreased cholesterol efflux from peripheral tissues leading to low levels of HDL-C. Although manipulating the LXR pathway may complement the effects of statins, LXR synthetic ligands as T091317 have shown significant hypertriglyceridemic action which limits their use. We recently found that the antidiabetic drug vildagliptin stimulates LXR expression leading to increased ABCB1/ABCG1 expression which improves cholesterol efflux from adipocytes. Therefore, a combination of vildagliptin and statin may provide a solution without the hypertriglyceridemic action observed with LXR agonist. We hypothesize that a combination of vildagliptin and pravastatin will improve cholesterol efflux in adipocytes. Statin-treated 3T3-L1 adipocytes were treated with vildagliptin, and the expression of LXR-ABCA1/ABCG1 cascade and the cholesterol efflux were then determined. Our data indicate that a combination of vildagliptin and pravastatin significantly induces the expression of LXR-ABCA1/ABCG1 cascade and improves cholesterol efflux (P > 0.05) in adipocytes. Our data may explain, at least in part, the improvement in HDL-C levels observed in patients receiving both medications. © 2016 IUBMB Life, 68(7):535-543, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

  9. Organotins Are Potent Activators of PPARγ and Adipocyte Differentiation in Bone Marrow Multipotent Mesenchymal Stromal Cells

    Science.gov (United States)

    Yanik, Susan C.; Baker, Amelia H.; Mann, Koren K.; Schlezinger, Jennifer J.

    2011-01-01

    Adipocyte differentiation in bone marrow is potentially deleterious to both bone integrity and lymphopoiesis. Here, we examine the hypothesis that organotins, common environmental contaminants that are dual ligands for peroxisome proliferator–activated receptor (PPAR) γ and its heterodimerization partner retinoid X receptor (RXR), are potent activators of bone marrow adipogenesis. A C57Bl/6-derived bone marrow multipotent mesenchymal stromal cell (MSC) line, BMS2, was treated with rosiglitazone, a PPARγ agonist, bexarotene, an RXR agonist, or a series of organotins. Rosiglitazone and bexarotene potently activated adipocyte differentiation; however, bexarotene had a maximal efficacy of only 20% of that induced by rosiglitazone. Organotins (tributyltin [TBT], triphenyltin, and dibutyltin) also stimulated adipocyte differentiation (EC50 of 10–20nM) but with submaximal, structure-dependent efficacy. In coexposures, both bexarotene and TBT enhanced rosiglitazone-induced adipogenesis. To investigate the contribution of PPARγ to TBT-induced adipogenesis, we examined expression of PPARγ2, as well as its transcriptional target FABP4. TBT-induced PPARγ2 and FABP4 protein expression with an efficacy intermediate between rosiglitazone and bexarotene, similar to lipid accumulation. A PPARγ antagonist and PPARγ-specific small hairpin RNA suppressed TBT-induced differentiation, although to a lesser extent than rosiglitazone-induced differentiation, suggesting that TBT may engage alternate pathways. TBT and bexarotene, but not rosiglitazone, also induced the expression of TGM2 (an RXR target) and ABCA1 (a liver X receptor target). The results show that an environmental contaminant, acting with the same potency as a therapeutic drug, induces PPARγ-dependent adipocyte differentiation in bone marrow MSCs. Activation of multiple nuclear receptor pathways by organotins may have significant implications for bone physiology. PMID:21622945

  10. Apoptosis inhibitor of macrophage (AIM) diminishes lipid droplet-coating proteins leading to lipolysis in adipocytes

    International Nuclear Information System (INIS)

    Iwamura, Yoshihiro; Mori, Mayumi; Nakashima, Katsuhiko; Mikami, Toshiyuki; Murayama, Katsuhisa; Arai, Satoko; Miyazaki, Toru

    2012-01-01

    Highlights: ► AIM induces lipolysis in a distinct manner from that of hormone-dependent lipolysis. ► AIM ablates activity of peroxisome proliferator-activated receptor in adipocytes. ► AIM reduces mRNA levels of lipid-droplet coating proteins leading to lipolysis. -- Abstract: Under fasting conditions, triacylglycerol in adipose tissue undergoes lipolysis to supply fatty acids as energy substrates. Such lipolysis is regulated by hormones, which activate lipases via stimulation of specific signalling cascades. We previously showed that macrophage-derived soluble protein, AIM induces obesity-associated lipolysis, triggering chronic inflammation in fat tissue which causes insulin resistance. However, the mechanism of how AIM mediates lipolysis remains unknown. Here we show that AIM induces lipolysis in a manner distinct from that of hormone-dependent lipolysis, without activation or augmentation of lipases. In vivo and in vitro, AIM did not enhance phosphorylation of hormone-sensitive lipase (HSL) in adipocytes, a hallmark of hormone-dependent lipolysis activation. Similarly, adipose tissue from obese AIM-deficient and wild-type mice showed comparable HSL phosphorylation. Consistent with the suppressive effect of AIM on fatty acid synthase activity, the amount of saturated and unsaturated fatty acids was reduced in adipocytes treated with AIM. This response ablated transcriptional activity of peroxisome proliferator-activated receptor (PPARγ), leading to diminished gene expression of lipid-droplet coating proteins including fat-specific protein 27 (FSP27) and Perilipin, which are indispensable for triacylglycerol storage in adipocytes. Accordingly, the lipolytic effect of AIM was overcome by a PPARγ-agonist or forced expression of FSP27, while it was synergized by a PPARγ-antagonist. Overall, distinct modes of lipolysis appear to take place in different physiological situations; one is a supportive response against nutritional deprivation achieved by

  11. Diclofenac and triamcinolone acetonide impair tenocytic differentiation and promote adipocytic differentiation of mesenchymal stem cells

    OpenAIRE

    Fredriksson, Maritha; Li, Yan; St?lman, Anders; Haldos?n, Lars-Arne; Fell?nder-Tsai, Li

    2013-01-01

    Background Tendinopathies are often empirically treated with oral/topical nonsteroidal anti-inflammatory medications and corticosteroid injections despite their unclear effects on tendon regeneration. Recent studies indicate that tendon progenitors exhibit stem cell-like properties, i.e., differentiation to osteoblasts, adipocytes, and chondrocytes, in addition to tenocytes. Our present study aims at understanding the effects of triamcinolone acetonide and diclofenac on tenocytic differentiat...

  12. Perilipin 1 Mediates Lipid Metabolism Homeostasis and Inhibits Inflammatory Cytokine Synthesis in Bovine Adipocytes

    Directory of Open Access Journals (Sweden)

    Shiqi Zhang

    2018-03-01

    Full Text Available Dairy cows with ketosis displayed lipid metabolic disorder and high inflammatory levels. Adipose tissue is an active lipid metabolism and endocrine tissue and is closely related to lipid metabolism homeostasis and inflammation. Perilipin 1 (PLIN1, an adipocyte-specific lipid-coated protein, may be involved in the above physiological function. The aim of this study is to investigate the role of PLIN1 in lipid metabolism regulation and inflammatory factor synthesis in cow adipocytes. The results showed that PLIN1 overexpression upregulated the expression of fatty acid and triglyceride (TAG synthesis molecule sterol regulator element-binding protein-1c (SREBP-1c and its target genes, diacylglycerol acyltransferase (DGAT 1, and DGAT2, but inhibited the expression of lipolysis enzymes hormone-sensitive lipase (HSL and CGI-58 for adipose triglyceride lipase (ATGL, thus augmenting the fatty acids and TAG synthesis and inhibiting lipolysis. Importantly, PLIN1 overexpression inhibited the activation of the NF-κB inflammatory pathway and decreased the expression and content of tumor necrosis factor alpha (TNF-α, interleukin 1 beta (IL-1β, and interleukin 6 (IL-6 induced by lipopolysaccharide. Conversely, PLIN1 silencing inhibited TAG synthesis, promoted lipolysis, and overinduced the activation of the NF-κB inflammatory pathway in cow adipocytes. In ketotic cows, the expression of PLIN1 was markedly decreased, whereas lipid mobilization, NF-κB pathway, and downstream inflammatory cytokines were overinduced in adipose tissue. Taken together, these results indicate that PLIN1 can maintain lipid metabolism homeostasis and inhibit the NF-κB inflammatory pathway in adipocytes. However, low levels of PLIN1 reduced the inhibitory effect on fat mobilization, NF-κB pathway, and inflammatory cytokine synthesis in ketotic cows.

  13. Perilipin 1 Mediates Lipid Metabolism Homeostasis and Inhibits Inflammatory Cytokine Synthesis in Bovine Adipocytes.

    Science.gov (United States)

    Zhang, Shiqi; Liu, Guowen; Xu, Chuang; Liu, Lei; Zhang, Qiang; Xu, Qiushi; Jia, Hongdou; Li, Xiaobing; Li, Xinwei

    2018-01-01

    Dairy cows with ketosis displayed lipid metabolic disorder and high inflammatory levels. Adipose tissue is an active lipid metabolism and endocrine tissue and is closely related to lipid metabolism homeostasis and inflammation. Perilipin 1 (PLIN1), an adipocyte-specific lipid-coated protein, may be involved in the above physiological function. The aim of this study is to investigate the role of PLIN1 in lipid metabolism regulation and inflammatory factor synthesis in cow adipocytes. The results showed that PLIN1 overexpression upregulated the expression of fatty acid and triglyceride (TAG) synthesis molecule sterol regulator element-binding protein-1c (SREBP-1c) and its target genes, diacylglycerol acyltransferase (DGAT) 1, and DGAT2, but inhibited the expression of lipolysis enzymes hormone-sensitive lipase (HSL) and CGI-58 for adipose triglyceride lipase (ATGL), thus augmenting the fatty acids and TAG synthesis and inhibiting lipolysis. Importantly, PLIN1 overexpression inhibited the activation of the NF-κB inflammatory pathway and decreased the expression and content of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) induced by lipopolysaccharide. Conversely, PLIN1 silencing inhibited TAG synthesis, promoted lipolysis, and overinduced the activation of the NF-κB inflammatory pathway in cow adipocytes. In ketotic cows, the expression of PLIN1 was markedly decreased, whereas lipid mobilization, NF-κB pathway, and downstream inflammatory cytokines were overinduced in adipose tissue. Taken together, these results indicate that PLIN1 can maintain lipid metabolism homeostasis and inhibit the NF-κB inflammatory pathway in adipocytes. However, low levels of PLIN1 reduced the inhibitory effect on fat mobilization, NF-κB pathway, and inflammatory cytokine synthesis in ketotic cows.

  14. Characterization of the bone marrow adipocyte niche with three-dimensional electron microscopy.

    Science.gov (United States)

    Robles, Hero; Park, SungJae; Joens, Matthew S; Fitzpatrick, James A J; Craft, Clarissa S; Scheller, Erica L

    2018-01-27

    Unlike white and brown adipose tissues, the bone marrow adipocyte (BMA) exists in a microenvironment containing unique populations of hematopoietic and skeletal cells. To study this microenvironment at the sub-cellular level, we performed a three-dimensional analysis of the ultrastructure of the BMA niche with focused ion beam scanning electron microscopy (FIB-SEM). This revealed that BMAs display hallmarks of metabolically active cells including polarized lipid deposits, a dense mitochondrial network, and areas of endoplasmic reticulum. The distinct orientations of the triacylglycerol droplets suggest that fatty acids are taken up and/or released in three key areas - at the endothelial interface, into the hematopoietic milieu, and at the bone surface. Near the sinusoidal vasculature, endothelial cells send finger-like projections into the surface of the BMA which terminate near regions of lipid within the BMA cytoplasm. In some regions, perivascular cells encase the BMA with their flattened cellular projections, limiting contacts with other cells in the niche. In the hematopoietic milieu, BMAT adipocytes of the proximal tibia interact extensively with maturing cells of the myeloid/granulocyte lineage. Associations with erythroblast islands are also prominent. At the bone surface, the BMA extends organelle and lipid-rich cytoplasmic regions toward areas of active osteoblasts. This suggests that the BMA may serve to partition nutrient utilization between diverse cellular compartments, serving as an energy-rich hub of the stromal-reticular network. Lastly, though immuno-EM, we've identified a subset of bone marrow adipocytes that are innervated by the sympathetic nervous system, providing an additional mechanism for regulation of the BMA. In summary, this work reveals that the bone marrow adipocyte is a dynamic cell with substantial capacity for interactions with the diverse components of its surrounding microenvironment. These local interactions likely contribute to

  15. The absence of 2,3-diphosphoglycerate from myocytes, hepatocytes and adipocytes.

    Science.gov (United States)

    Reddy, W J; Burns, A H

    1976-04-23

    Myocytes, hepatocytes and adipocytes were prepared from heart, liver and epididymal fat pad of the rat. No detectable level of 2,3-diphosphoglycerate was found. Evidence is also presented which indicates the absence from these cells of 2,3-diphosphoglycerate mutase and 2,3-diphosphoglycerate phosphatase. Previous findings by others of the presence of 2,3-diphosphoglycerate and 2,3-diphosphoglycerate mutase probably resulted from erythrocytes sequestered in the tissue.

  16. Involvement of AMP-activated protein kinase in control of adipocyte metabolism during starvation

    Czech Academy of Sciences Publication Activity Database

    Kopecký, Jan; Šponarová, Jana; Mustard, K. J.; Flachs, Pavel; Horáková, Olga; Rossmeisl, Martin; Bardová, Kristina; Thomason-Hughes, M.; Braunerová, Radka; Hardie, D. G.

    2005-01-01

    Roč. 6, č. S1 (2005), s. 52-52 ISSN 1467-7881. [European Congress on Obesity /14./. 01.06.2005-04.06.2005, Athens] R&D Projects: GA MŠk(CZ) 1M0520; GA ČR GA303/05/2580 Institutional research plan: CEZ:AV0Z50110509 Keywords : AMPK * adipocyte * starvation * fatty acid oxidation Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  17. Contributions of Cytogenetics and Molecular Cytogenetics to the Diagnosis of Adipocytic Tumors

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    Jun Nishio

    2011-01-01

    Full Text Available Over the last 20 years, a number of tumor-specific chromosomal translocations and associated fusion genes have been identified for mesenchymal neoplasms including adipocytic tumors. The addition of molecular cytogenetic techniques, especially fluorescence in situ hybridization (FISH, has further enhanced the sensitivity and accuracy of detecting nonrandom chromosomal translocations and/or other rearrangements in adipocytic tumors. Indeed, most resent molecular cytogenetic analysis has demonstrated a translocation t(11;16(q13;p13 that produces a C11orf95-MKL2 fusion gene in chondroid lipoma. Additionally, it is well recognized that supernumerary ring and/or giant rod chromosomes are characteristic for atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma, and amplification of 12q13–15 involving the MDM2, CDK4, and CPM genes is shown by FISH in these tumors. Moreover, myxoid/round cell liposarcoma is characterized by a translocation t(12;16(q13;p11 that fuses the DDIT3 and FUS genes. This paper provides an overview of the role of conventional cytogenetics and molecular cytogenetics in the diagnosis of adipocytic tumors.

  18. Dynamic Metabolomics Reveals that Insulin Primes the Adipocyte for Glucose Metabolism

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    James R. Krycer

    2017-12-01

    Full Text Available Insulin triggers an extensive signaling cascade to coordinate adipocyte glucose metabolism. It is considered that the major role of insulin is to provide anabolic substrates by activating GLUT4-dependent glucose uptake. However, insulin stimulates phosphorylation of many metabolic proteins. To examine the implications of this on glucose metabolism, we performed dynamic tracer metabolomics in cultured adipocytes treated with insulin. Temporal analysis of metabolite concentrations and tracer labeling revealed rapid and distinct changes in glucose metabolism, favoring specific glycolytic branch points and pyruvate anaplerosis. Integrating dynamic metabolomics and phosphoproteomics data revealed that insulin-dependent phosphorylation of anabolic enzymes occurred prior to substrate accumulation. Indeed, glycogen synthesis was activated independently of glucose supply. We refer to this phenomenon as metabolic priming, whereby insulin signaling creates a demand-driven system to “pull” glucose into specific anabolic pathways. This complements the supply-driven regulation of anabolism by substrate accumulation and highlights an additional role for insulin action in adipocyte glucose metabolism.

  19. Cinnamon extract regulates glucose transporter and insulin-signaling gene expression in mouse adipocytes.

    Science.gov (United States)

    Cao, Heping; Graves, Donald J; Anderson, Richard A

    2010-11-01

    Cinnamon extracts (CE) are reported to have beneficial effects on people with normal and impaired glucose tolerance, the metabolic syndrome, type 2 diabetes, and insulin resistance. However, clinical results are controversial. Molecular characterization of CE effects is limited. This study investigated the effects of CE on gene expression in cultured mouse adipocytes. Water-soluble CE was prepared from ground cinnamon (Cinnamomum burmannii). Quantitative real-time PCR was used to investigate CE effects on the expression of genes coding for adipokines, glucose transporter (GLUT) family, and insulin-signaling components in mouse 3T3-L1 adipocytes. CE (100 μg/ml) increased GLUT1 mRNA levels 1.91±0.15, 4.39±0.78, and 6.98±2.18-fold of the control after 2-, 4-, and 16-h treatments, respectively. CE decreased the expression of further genes encoding insulin-signaling pathway proteins including GSK3B, IGF1R, IGF2R, and PIK3R1. This study indicates that CE regulates the expression of multiple genes in adipocytes and this regulation could contribute to the potential health benefits of CE. Published by Elsevier GmbH.

  20. Lactacystin inhibits 3T3-L1 adipocyte differentiation through induction of CHOP-10 expression

    International Nuclear Information System (INIS)

    Li Xi; Huang Haiyan; Chen Jiegen; Jiang Lin; Liu Honglei; Liu Deguo; Song Tanjing; He Qun; Ma Chungu; Ma Duan; Song Houyan; Tang Qiqun

    2006-01-01

    Hormonal induction triggers a cascade leading to the expression of CCAAT/enhancer-binding protein(C/EBP)α and peroxisome proliferator-activated receptor (PPAR) γ, C/EBPα, and PPARγ turns on series of adipocyte genes that give rise to the adipocyte phenotype. Previous findings indicate that C/EBPβ, a transcriptional activator of the C/EBPα and PPARγ genes, is rapidly expressed after induction, but lacks DNA-binding activity and therefore cannot activate transcription of the C/EBPα and PPARγ genes early in the differentiation program. Acquisition of DNA-binding activity of C/EBPβ occurs when CHOP-10, a dominant-negative form of C/EBP family members, is down-regulated and becomes hyperphosphorylated as preadipocytes traverse the G 1 -S checkpoint of mitotic clonal expansion. Evidences are presented in this report that lactacystin, a proteasome inhibitor, up-regulated the CHOP-10 expression, blocked the DNA-binding activity of C/EBPβ, and subsequently inhibited MCE as well as adipocyte differentiation

  1. Transcription regulator TRIP-Br2 mediates ER stress-induced brown adipocytes dysfunction.

    Science.gov (United States)

    Qiang, Guifen; Whang Kong, Hyerim; Gil, Victoria; Liew, Chong Wee

    2017-01-09

    In contrast to white adipose tissue, brown adipose tissue (BAT) is known to play critical roles for both basal and inducible energy expenditure. Obesity is associated with reduction of BAT function; however, it is not well understood how obesity promotes BAT dysfunction, especially at the molecular level. Here we show that the transcription regulator TRIP-Br2 mediates ER stress-induced inhibition of lipolysis and thermogenesis in BAT. Using in vitro, ex vivo, and in vivo approaches, we demonstrate that obesity-induced inflammation upregulates brown adipocytes TRIP-Br2 expression via the ER stress pathway and amelioration of ER stress in mice completely abolishes high fat diet-induced upregulation of TRIP-Br2 in BAT. We find that increased TRIP-Br2 significantly inhibits brown adipocytes thermogenesis. Finally, we show that ablation of TRIP-Br2 ameliorates ER stress-induced inhibition on lipolysis, fatty acid oxidation, oxidative metabolism, and thermogenesis in brown adipocytes. Taken together, our current study demonstrates a role for TRIP-Br2 in ER stress-induced BAT dysfunction, and inhibiting TRIP-Br2 could be a potential approach for counteracting obesity-induced BAT dysfunction.

  2. Ginkgolide C Suppresses Adipogenesis in 3T3-L1 Adipocytes via the AMPK Signaling Pathway

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    Chian-Jiun Liou

    2015-01-01

    Full Text Available Ginkgolide C, isolated from Ginkgo biloba leaves, is a flavone reported to have multiple biological functions, from decreased platelet aggregation to ameliorating Alzheimer disease. The study aim was to evaluate the antiadipogenic effect of ginkgolide C in 3T3-L1 adipocytes. Ginkgolide C was used to treat differentiated 3T3-L1 cells. Cell supernatant was collected to assay glycerol release, and cells were lysed to measure protein and gene expression related to adipogenesis and lipolysis by western blot and real-time PCR, respectively. Ginkgolide C significantly suppressed lipid accumulation in differentiated adipocytes. It also decreased adipogenesis-related transcription factor expression, including peroxisome proliferator-activated receptor and CCAAT/enhancer-binding protein. Furthermore, ginkgolide C enhanced adipose triglyceride lipase and hormone-sensitive lipase production for lipolysis and increased phosphorylation of AMP-activated protein kinase (AMPK, resulting in decreased activity of acetyl-CoA carboxylase for fatty acid synthesis. In coculture with an AMPK inhibitor (compound C, ginkgolide C also improved activation of sirtuin 1 and phosphorylation of AMPK in differentiated 3T3-L1 cells. The results suggest that ginkgolide C is an effective flavone for increasing lipolysis and inhibiting adipogenesis in adipocytes through the activated AMPK pathway.

  3. Transcriptional activation of melanocortin 2 receptor accessory protein by PPARγ in adipocytes

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    Kim, Nam Soo; Kim, Yoon-Jin [Department of Biology, Research Institute for Basic Science, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Cho, Si Young [R and D Center, Amore Pacific Corporation, Yongin-si, Gyeonggi-do 446-729 (Korea, Republic of); Lee, Tae Ryong, E-mail: trlee@amorepacific.com [R and D Center, Amore Pacific Corporation, Yongin-si, Gyeonggi-do 446-729 (Korea, Republic of); Kim, Sang Hoon, E-mail: shkim@khu.ac.kr [Department of Biology, Research Institute for Basic Science, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

    2013-09-27

    Highlights: •MRAP enhanced HSL expression. •ACTH-mediated MRAP reduced glycerol release. •PPARγ induced MRAP expression. •PPARγ bound to the MRAP promoter. -- Abstract: Adrenocorticotropic hormone (ACTH) in rodents decreases lipid accumulation and body weight. Melanocortin receptor 2 (MC2R) and MC2R accessory protein (MRAP) are specific receptors for ACTH in adipocytes. Peroxisome proliferator-activated receptor γ (PPARγ) plays a role in the transcriptional regulation of metabolic pathways such as adipogenesis and β-oxidation of fatty acids. In this study we investigated the transcriptional regulation of MRAP expression during differentiation of 3T3-L1 cells. Stimulation with ACTH affected lipolysis in murine mature adipocytes via MRAP. Putative peroxisome proliferator response element (PPRE) was identified in the MRAP promoter region. In chromatin immunoprecipitation and reporter assays, we observed binding of PPARγ to the MRAP promoter. The mutagenesis experiments showed that the −1209/−1198 region of the MRAP promoter could function as a PPRE site. These results suggest that PPARγ is required for transcriptional activation of the MRAP gene during adipogenesis, which contributes to understanding of the molecular mechanism of lipolysis in adipocytes.

  4. Monoethylhexyl Phthalate Elicits an Inflammatory Response in Adipocytes Characterized by Alterations in Lipid and Cytokine Pathways.

    Science.gov (United States)

    Manteiga, Sara; Lee, Kyongbum

    2017-04-01

    A growing body of evidence links endocrine-disrupting chemicals (EDCs) with obesity-related metabolic diseases. While it has been shown that EDCs can predispose individuals toward adiposity by affecting developmental processes, little is known about the chemicals' effects on adult adipose tissue. Our aim was to study the effects of low, physiologically relevant doses of EDCs on differentiated murine adipocytes. We combined metabolomics, proteomics, and gene expression analysis to characterize the effects of mono-ethylhexyl phthalate (MEHP) in differentiated adipocytes. Repeated exposure to MEHP over several days led to changes in metabolite and enzyme levels indicating elevated lipogenesis and lipid oxidation. The chemical exposure also increased expression of major inflammatory cytokines, including chemotactic factors. Proteomic and gene expression analysis revealed significant alterations in pathways regulated by peroxisome proliferator activated receptor-γ (PPARγ). Inhibiting the nuclear receptor's activity using a chemical antagonist abrogated not only the alterations in PPARγ-regulated metabolic pathways, but also the increases in cytokine expression. Our results show that MEHP can induce a pro-inflammatory state in differentiated adipocytes. This effect is at least partially mediated PPARγ.

  5. Transcriptional activation of melanocortin 2 receptor accessory protein by PPARγ in adipocytes

    International Nuclear Information System (INIS)

    Kim, Nam Soo; Kim, Yoon-Jin; Cho, Si Young; Lee, Tae Ryong; Kim, Sang Hoon

    2013-01-01

    Highlights: •MRAP enhanced HSL expression. •ACTH-mediated MRAP reduced glycerol release. •PPARγ induced MRAP expression. •PPARγ bound to the MRAP promoter. -- Abstract: Adrenocorticotropic hormone (ACTH) in rodents decreases lipid accumulation and body weight. Melanocortin receptor 2 (MC2R) and MC2R accessory protein (MRAP) are specific receptors for ACTH in adipocytes. Peroxisome proliferator-activated receptor γ (PPARγ) plays a role in the transcriptional regulation of metabolic pathways such as adipogenesis and β-oxidation of fatty acids. In this study we investigated the transcriptional regulation of MRAP expression during differentiation of 3T3-L1 cells. Stimulation with ACTH affected lipolysis in murine mature adipocytes via MRAP. Putative peroxisome proliferator response element (PPRE) was identified in the MRAP promoter region. In chromatin immunoprecipitation and reporter assays, we observed binding of PPARγ to the MRAP promoter. The mutagenesis experiments showed that the −1209/−1198 region of the MRAP promoter could function as a PPRE site. These results suggest that PPARγ is required for transcriptional activation of the MRAP gene during adipogenesis, which contributes to understanding of the molecular mechanism of lipolysis in adipocytes

  6. Adipocytes enhance murine pancreatic cancer growth via a hepatocyte growth factor (HGF)-mediated mechanism.

    Science.gov (United States)

    Ziegler, Kathryn M; Considine, Robert V; True, Eben; Swartz-Basile, Deborah A; Pitt, Henry A; Zyromski, Nicholas J

    2016-04-01

    Obesity accelerates the development and progression of pancreatic cancer, though the mechanisms underlying this association are unclear. Adipocytes are biologically active, producing factors such as hepatocyte growth factor (HGF) that may influence tumor progression. We therefore sought to test the hypothesis that adipocyte-secreted factors including HGF accelerate pancreatic cancer cell proliferation. Murine pancreatic cancer cells (Pan02 and TGP-47) were grown in a) conditioned medium (CM) from murine F442A preadipocytes, b) HGF-knockdown preadipocyte CM, c) recombinant murine HGF at increasing doses, and d) CM plus HGF-receptor (c-met) inhibitor. Cell proliferation was measured using the MTT assay. ANOVA and t-test were applied; p TGP-47 cell proliferation relative to control (59 ± 12% and 34 ± 12%, p TGP-47 cells remained unchanged. Recombinant HGF dose-dependently increased Pan02, but not TGP-47, proliferation (p TGP-47 cells. These experiments demonstrate that adipocyte-derived factors accelerate murine pancreatic cancer proliferation. In the case of Pan02 cells, HGF is responsible, in part, for this proliferation. Copyright © 2016 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

  7. Vitisin A inhibits adipocyte differentiation through cell cycle arrest in 3T3-L1 cells

    International Nuclear Information System (INIS)

    Kim, Soon-hee; Park, Hee-Sook; Lee, Myoung-su; Cho, Yong-Jin; Kim, Young-Sup; Hwang, Jin-Taek; Sung, Mi Jeong; Kim, Myung Sunny; Kwon, Dae Young

    2008-01-01

    Inhibition of adipocyte differentiation is one approach among the anti-obesity strategies. This study demonstrates that vitisin A, a resveratrol tetramer, inhibits adipocyte differentiation most effectively of 18 stilbenes tested. Fat accumulation and PPARγ expression were decreased by vitisin A in a dose-dependent manner. Vitisin A significantly inhibited preadipocyte proliferation and consequent differentiation within the first 2 days of treatment, indicating that the anti-adipogenic effect of vitisin A was derived from anti-proliferation. Based on cell cycle analysis, vitisin A blocked the cell cycle at the G1-S phase transition, causing cells to remain in the preadipocyte state. Vitisin A increased p21 expression, while the Rb phosphorylation level was reduced. Therefore, vitisin A seems to induce G1 arrest through p21- and consequent Rb-dependent suppression of transcription. On the other hand, ERK and Akt signaling pathways were not involved in the anti-mitotic regulation by vitisin A. Taken together, these results suggest that vitisin A inhibits adipocyte differentiation through preadipocyte cell cycle arrest

  8. Reciprocal Inflammatory Signaling Between Intestinal Epithelial Cells and Adipocytes in the Absence of Immune Cells

    Directory of Open Access Journals (Sweden)

    Yu Takahashi

    2017-09-01

    Full Text Available Visceral fat accumulation as observed in Crohn's disease and obesity is linked to chronic gut inflammation, suggesting that accumulation of gut adipocytes can trigger local inflammatory signaling. However, direct interactions between intestinal epithelial cells (IECs and adipocytes have not been investigated, in part because IEC physiology is difficult to replicate in culture. In this study, we originally prepared intact, polarized, and cytokine responsive IEC monolayers from primary or induced pluripotent stem cell-derived intestinal organoids by simple and repeatable methods. When these physiological IECs were co-cultured with differentiated adipocytes in Transwell, pro-inflammatory genes were induced in both cell types, suggesting reciprocal inflammatory activation in the absence of immunocompetent cells. These inflammatory responses were blocked by nuclear factor-κB or signal transducer and activator of transcription 3 inhibition and by anti-tumor necrosis factor- or anti-interleukin-6-neutralizing antibodies. Our results highlight the utility of these monolayers for investigating IEC biology. Furthermore, this system recapitulates the intestinal epithelium–mesenteric fat signals that potentially trigger or worsen inflammatory disorders such as Crohn's disease and obesity-related enterocolitis.

  9. Association of Adipocyte Fatty Acid–Binding Protein (FABP4 Level with Obesity in Women

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    Hussein Jasim AL-Harbi

    2017-02-01

    Full Text Available Adipocyte Fatty Acid–Binding Protein(FABP 4 is produced by mature adipocytes, cytoplasmic lipid protein carrier, 132 amino acid and secretion increases during adipogenesis. Chemerin is adipocytokine anewly discovered novel adipokine that regulates adipocyte metabolism and adipogenesis, is The aim of this study is to investigated the relationship of chemerin and FABP4 level with obesity and identifing the usefulness of waist circumference (WC, hip circumference , waist-to-hip ratio (WHR, body mass index (BMI,, and body fat percentage( BF% in screening obesity . Anthropometric data were collected for 180 healthy women with an age range 35-60 years, divided into four groups due to body mass index: normalweight (18.5-24.9 kg/m2, overweight (25-29.9 kg/m2 , obese (30-39.9 kg/m2 and morbid(≥ 40 kg/m2. The results revealed that FABP4 and Chemerin circulating concentration were significantly increased (P<0.01 in healthy morbid and obese adult women when compared with lean healthy (normal and over weight women also significant increase of A-FABP and Chemerin with the body mass index (BMI, waist hip ratio, hip circumference, waist circumference, and with BF percentage. According to these finding suggest that the circulating chemerin and A-FABP levels can be used as Prediction marker of overall fat mass and obesity in women.

  10. Metformin induces oxidative stress in white adipocytes and raises uncoupling protein 2 levels.

    Science.gov (United States)

    Anedda, Andrea; Rial, Eduardo; González-Barroso, M Mar

    2008-10-01

    Metformin is a drug widely used to treat type 2 diabetes. It enhances insulin sensitivity by improving glucose utilization in tissues like liver or muscle. Metformin inhibits respiration, and the decrease in cellular energy activates the AMP-activated protein kinase that in turn switches on catabolic pathways. Moreover, metformin increases lipolysis and beta-oxidation in white adipose tissue, thereby reducing the triglyceride stores. The uncoupling proteins (UCPs) are transporters that lower the efficiency of mitochondrial oxidative phosphorylation. UCP2 is thought to protect against oxidative stress although, alternatively, it could play an energy dissipation role. The aim of this work was to analyse the involvement of UCP2 on the effects of metformin in white adipocytes. We studied the effect of this drug in differentiating 3T3-L1 adipocytes and found that metformin causes oxidative stress since it increases the levels of reactive oxygen species (ROS) and lowers the aconitase activity. Variations in UCP2 protein levels parallel those of ROS. Metformin also increases lipolysis in these cells although only when the levels of ROS and UCP2 have decreased. Hence, UCP2 does not appear to be needed to facilitate fatty acid oxidation. Furthermore, treatment of C57BL/6 mice with metformin also augmented the levels of UCP2 in epididymal white adipose tissue. We conclude that metformin treatment leads to the overexpression of UCP2 in adipocytes to minimize the oxidative stress that is probably due to the inhibition of respiration caused by the drug.

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

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    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.

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

    Science.gov (United States)

    Kishida, Tsunao; Ejima, Akika; Yamamoto, Kenta; Tanaka, Seiji; Yamamoto, Toshiro; Mazda, Osam

    2015-10-13

    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. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Influence of epidermal growth factor (EGF) and hydrocortisone on the co-culture of mature adipocytes and endothelial cells for vascularized adipose tissue engineering.

    Science.gov (United States)

    Huber, Birgit; Czaja, Alina Maria; Kluger, Petra Juliane

    2016-05-01

    The composition of vascularized adipose tissue is still an ongoing challenge as no culture medium is available to supply adipocytes and endothelial cells appropriately. Endothelial cell medium is typically supplemented with epidermal growth factor (EGF) as well as hydrocortisone (HC). The effect of EGF on adipocytes is discussed controversially. Some studies say it inhibits adipocyte differentiation while others reported of improved adipocyte lipogenesis. HC is known to have lipolytic activities, which might result in mature adipocyte dedifferentiation. In this study, we evaluated the influence of EGF and HC on the co-culture of endothelial cells and mature adipocytes regarding their cell morphology and functionality. We showed in mono-culture that high levels of HC promoted dedifferentiation and proliferation of mature adipocytes, whereas EGF seemed to have no negative influence. Endothelial cells kept their typical cobblestone morphology and showed a proliferation rate comparable to the control independent of EGF and HC concentration. In co-culture, HC promoted dedifferentiation of mature adipocytes, which was shown by a higher glycerol release. EGF had no negative impact on adipocyte morphology. No negative impact on endothelial cell morphology and functionality could be seen with reduced EGF and HC supplementation in co-culture with mature adipocytes. Taken together, our results demonstrate that reduced levels of HC are needed for co-culturing mature adipocytes and endothelial cells. In co-culture, EGF had no influence on mature adipocytes. Therefore, for the composition of vascularized adipose tissue constructs, the media with low levels of HC and high or low levels of EGF can be used. © 2016 International Federation for Cell Biology.

  14. Developmental Programming: Impact of Prenatal Testosterone Excess on Steroidal Machinery and Cell Differentiation Markers in Visceral Adipocytes of Female Sheep.

    Science.gov (United States)

    Puttabyatappa, Muraly; Lu, Chunxia; Martin, Jacob D; Chazenbalk, Gregorio; Dumesic, Daniel; Padmanabhan, Vasantha

    2017-01-01

    Prenatal testosterone (T)-treated female sheep manifest reduced adipocyte size and peripheral insulin resistance. The small adipocyte phenotype may reflect defects in adipogenesis and its steroidal machinery. To test whether prenatal T treatment from gestational days 30 to 90 alters the visceral adipose tissue (VAT) steroidal machinery and reduces adipocyte differentiation, we examined expression of the steroidogenic enzymes, steroid receptors, and adipocyte differentiation markers at fetal day 90 and postnatal ages 10 and 21 months. Because gestational T treatment increases fetal T and maternal insulin, the contributions of these were assessed by androgen receptor antagonist or insulin sensitizer cotreatment, either separately (at fetal day 90 and 21 months of age time points) or together (10 months of age). The effects on adipogenesis were assessed in the VAT-derived mesenchymal stem cells (AT-MSCs) from pre- and postpubertal time points to evaluate the effects of pubertal steroidal changes on adipogenesis. Our results show that VAT manifests potentially a predominant estrogenic intracrine milieu (increased aromatase and estrogen receptor α) and reduced differentiation markers at fetal day 90 and postnatal 21 months of age. These changes appear to involve both androgenic and metabolic pathways. Preliminary findings suggest that prenatal T treatment reduces adipogenesis, decreases expression of differentiation, and increases expression of commitment markers at both pre- and postpubertal time points. Together, these findings suggest that (1) increased commitment of AT-MSCs to adipocyte lineage and decreased differentiation to adipocytes may underlie the small adipocyte phenotype of prenatal T-treated females and (2) excess T-induced changes in steroidal machinery in the VAT likely participate in the programming/maintenance of this defect.

  15. The effects of knee immobilization on marrow adipocyte hyperplasia and hypertrophy at the proximal rat tibia epiphysis.

    Science.gov (United States)

    Trudel, Guy; Uhthoff, Hans K; Solanki, Sanjay; Laneuville, Odette

    2017-09-01

    Marrow adipose deposition is observed during aging and in association with extended periods of immobility. The objective of this study was to determine the contribution of adipocyte hypertrophy and hyperplasia to bone marrow fat deposition induced by immobilization of the rat knee joint for 2, 4, 16 or 32 weeks. Histomorphometric analyses compared immobilized to sham-operated proximal tibia from age and gender matched rats to assess the contribution of aging and duration of immobilization on the number and size of marrow adipocytes. Results indicated that marrow adipose tissue increased with the duration of immobilization and was significant larger at 16 weeks compared to the sham-operated group (0.09956±0.13276mm 2 vs 0.01990±0.01100mm 2 , p=0.047). The marrow adipose tissue was characterized by hyperplasia of adipocytes with a smaller average size after 2 and 4 weeks of immobilization (at 2 weeks hyperplasia: 68.86±33.62 vs 43.57±24.47 adipocytes/mm 2 , p=0.048; at 4 weeks hypotrophy: 0.00036±0.00019 vs 0.00046±0.00023mm 2 , p=0.027), and by adipocyte hypertrophy after 16 weeks of immobilization (0.00083±0.00049 vs 0.00046±0.00028mm 2 , p=0.027) compared to sham-operated. Both immobilized and sham-operated groups showed marrow adipose conversion with age; immobilized (p=0.008; sham: p=0.003). Overall, fat deposition in the bone marrow of the proximal rat tibia epiphysis and induced by knee joint immobilization was characterized by hyperplasia of small adipocytes in the early phase and by adipocyte hypertrophy in the later phase. Mediators of marrow fat deposition after immobilization and preventive countermeasures need to be investigated. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. Adipose tissue macrophages impair preadipocyte differentiation in humans.

    Directory of Open Access Journals (Sweden)

    Li Fen Liu

    Full Text Available The physiologic mechanisms underlying the relationship between obesity and insulin resistance are not fully understood. Impaired adipocyte differentiation and localized inflammation characterize adipose tissue from obese, insulin-resistant humans. The directionality of this relationship is not known, however. The aim of the current study was to investigate whether adipose tissue inflammation is causally-related to impaired adipocyte differentiation.Abdominal subcutaneous(SAT and visceral(VAT adipose tissue was obtained from 20 human participants undergoing bariatric surgery. Preadipocytes were isolated, and cultured in the presence or absence of CD14+ macrophages obtained from the same adipose tissue sample. Adipocyte differentiation was quantified after 14 days via immunofluorescence, Oil-Red O, and adipogenic gene expression. Cytokine secretion by mature adipocytes cultured with or without CD14+macrophages was quantified.Adipocyte differentiation was significantly lower in VAT than SAT by all measures (p<0.001. With macrophage removal, SAT preadipocyte differentiation increased significantly as measured by immunofluorescence and gene expression, whereas VAT preadipocyte differentiation was unchanged. Adipocyte-secreted proinflammatory cytokines were higher and adiponectin lower in media from VAT vs SAT: macrophage removal reduced inflammatory cytokine and increased adiponectin secretion from both SAT and VAT adipocytes. Differentiation of preadipocytes from SAT but not VAT correlated inversely with systemic insulin resistance.The current results reveal that proinflammatory immune cells in human SAT are causally-related to impaired preadipocyte differentiation, which in turn is associated with systemic insulin resistance. In VAT, preadipocyte differentiation is poor even in the absence of tissue macrophages, pointing to inherent differences in fat storage potential between the two depots.

  17. Adsorption of human tear lipocalin to human meibomian lipid films.

    Science.gov (United States)

    Millar, Thomas J; Mudgil, Poonam; Butovich, Igor A; Palaniappan, Chendur K

    2009-01-01

    Tear lipocalin (Tlc) is a major lipid binding protein in tears and is thought to have an important role in stabilizing the Meibomian lipid layer by transferring lipids to it from the aqueous layer or ocular surface, or by adsorbing to it directly. These possible roles have been investigated in vitro using human Tlc. Tlc was purified from human tears by size exclusion chromatography followed by ion exchange chromatography. Three additional samples of the Tlc were prepared by lipidation, delipidation, and relipidation. The lipids extracted from the purified Tlc were analyzed by HPLC-MS followed by fragmentation. Adsorption of these different forms of Tlc to a human Meibomian lipid film spread on the surface of an artificial tear buffer in a Langmuir trough were observed by recording changes in the pressure with time (Pi-T profile) and monitoring the appearance of the film microscopically. These results were compared with similar experiments using a bovine Meibomian lipid film. The results indicated that Tlc binds slowly to a human Meibomian lipid film compared with lysozyme or lactoferrin, even at 37 degrees C. The adsorption of Tlc to a human Meibomian lipid film was very different from its adsorption to a bovine Meibomian lipid film, indicating the nature of the lipids in the film is critical to the adsorption process. Similarly, the different forms of Tlc had quite distinct adsorption patterns, as indicated both by changes in Pi-T profiles and the microscopic appearance of the films. It was concluded that human Tlc was capable of adsorbing to and penetrating into a Meibomian lipid layer, but this process is very complex and depends on both the types of lipids bound to Tlc and the lipid complement comprising the Meibomian lipid film.

  18. Adsorption of Human Tear Lipocalin to Human Meibomian Lipid Films

    Science.gov (United States)

    Millar, Thomas J.; Mudgil, Poonam; Butovich, Igor A.; Palaniappan, Chendur K.

    2009-01-01

    Purpose Tear lipocalin (Tlc) is a major lipid binding protein in tears and is thought to have an important role in stabilizing the Meibomian lipid layer by transferring lipids to it from the aqueous layer or ocular surface, or by adsorbing to it directly. These possible roles have been investigated in vitro using human Tlc. Methods Tlc was purified from human tears by size exclusion chromatography followed by ion exchange chromatography. Three additional samples of the Tlc were prepared by lipidation, delipidation, and relipidation. The lipids extracted from the purified Tlc were analyzed by HPLC-MS followed by fragmentation. Adsorption of these different forms of Tlc to a human Meibomian lipid film spread on the surface of an artificial tear buffer in a Langmuir trough were observed by recording changes in the pressure with time (∏-T profile) and monitoring the appearance of the film microscopically. These results were compared with similar experiments using a bovine Meibomian lipid film. Results The results indicated that Tlc binds slowly to a human Meibomian lipid film compared with lysozyme or lactoferrin, even at 37°C. The adsorption of Tlc to a human Meibomian lipid film was very different from its adsorption to a bovine Meibomian lipid film, indicating the nature of the lipids in the film is critical to the adsorption process. Similarly, the different forms of Tlc had quite distinct adsorption patterns, as indicated both by changes in ∏-T profiles and the microscopic appearance of the films. Conclusions It was concluded that human Tlc was capable of adsorbing to and penetrating into a Meibomian lipid layer, but this process is very complex and depends on both the types of lipids bound to Tlc and the lipid complement comprising the Meibomian lipid film. PMID:18757516

  19. The production of coagulation factor VII by adipocytes is enhanced by tumor necrosis factor-α or isoproterenol.

    Science.gov (United States)

    Takahashi, N; Yoshizaki, T; Hiranaka, N; Kumano, O; Suzuki, T; Akanuma, M; Yui, T; Kanazawa, K; Yoshida, M; Naito, S; Fujiya, M; Kohgo, Y; Ieko, M

    2015-05-01

    A relationship has been reported between blood concentrations of coagulation factor VII (FVII) and obesity. In addition to its role in coagulation, FVII has been shown to inhibit insulin signals in adipocytes. However, the production of FVII by adipocytes remains unclear. We herein investigated the production and secretion of FVII by adipocytes, especially in relation to obesity-related conditions including adipose inflammation and sympathetic nerve activation. C57Bl/6J mice were fed a low- or high-fat diet and the expression of FVII messenger RNA (mRNA) was then examined in adipose tissue. 3T3-L1 cells were used as an adipocyte model for in vitro experiments in which these cells were treated with tumor necrosis factor-α (TNF-α) or isoproterenol. The expression and secretion of FVII were assessed by quantitative real-time PCR, Western blotting and enzyme-linked immunosorbent assays. The expression of FVII mRNA in the adipose tissue of mice fed with high-fat diet was significantly higher than that in mice fed with low-fat diet. Expression of the FVII gene and protein was induced during adipogenesis and maintained in mature adipocytes. The expression and secretion of FVII mRNA were increased in the culture medium of 3T3-L1 adipocytes treated with TNF-α, and these effects were blocked when these cells were exposed to inhibitors of mitogen-activated kinases or NF-κB activation. The β-adrenoceptor agonist isoproterenol stimulated the secretion of FVII from mature adipocytes via the cyclic AMP/protein kinase A pathway. Blockade of secreted FVII with the anti-FVII antibody did not affect the phosphorylation of Akt in the isoproterenol-stimulated adipocytes. Obese adipose tissue produced FVII. The production and secretion of FVII by adipocytes was enhanced by TNF-α or isoproterenol via different mechanisms. These results indicate that FVII is an adipokine that plays an important role in the pathogenesis of obesity.

  20. Phagocytosis of haemozoin (malarial pigment enhances metalloproteinase-9 activity in human adherent monocytes: Role of IL-1beta and 15-HETE

    Directory of Open Access Journals (Sweden)

    Giribaldi Giuliana

    2008-08-01

    Full Text Available Abstract Background It has been shown previously that human monocytes fed with haemozoin (HZ or trophozoite-parasitized RBCs displayed increased matrix metalloproteinase-9 (MMP-9 enzyme activity and protein/mRNA expression and increased TNF production, and showed higher matrix invasion ability. The present study utilized the same experimental model to analyse the effect of phagocytosis of: HZ, delipidized HZ, beta-haematin (lipid-free synthetic HZ and trophozoites on production of IL-1beta and MMP-9 activity and expression. The second aim was to find out which component of HZ was responsible for the effects. Methods Native HZ freshly isolated from Plasmodium falciparum (Palo Alto strain, Mycoplasma-free, delipidized HZ, beta-haematin (lipid-free synthetic HZ, trophozoites and control meals such as opsonized non-parasitized RBCs and inert latex particles, were fed to human monocytes. The production of IL-1beta by differently fed monocytes, in presence or absence of specific MMP-9 inhibitor or anti-hIL-1beta antibodies, was quantified in supernatants by ELISA. Expression of IL-1beta was analysed by quantitative real-time RT-PCR. MMP-9 activity and protein expression were quantified by gelatin zymography and Western blotting. Results Monocytes fed with HZ or trophozoite-parasitized RBCs generated increased amounts of IL-1beta and enhanced enzyme activity (in cell supernatants and protein/mRNA expression (in cell lysates of monocyte MMP-9. The latter appears to be causally related to enhanced IL-1beta production, as enhancement of both expression and enzyme activity were abrogated by anti-hIL-1beta Abs. Upregulation of IL-1beta and MMP-9 were absent in monocytes fed with beta-haematin or delipidized HZ, indicating a role for HZ-attached or HZ-generated lipid components. 15-HETE (15(S,R-hydroxy-6,8,11,13-eicosatetraenoic acid a potent lipoperoxidation derivative generated by HZ from arachidonic acid via haem-catalysis was identified as one mediator

  1. Aculeatin, a coumarin derived from Toddalia asiatica (L.) Lam., enhances differentiation and lipolysis of 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Akio, E-mail: watanabea@jfrl.or.jp [Japan Food Research Laboratories, Osaka 567-0085 (Japan); Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Miyagi 981-8555 (Japan); Kato, Tsuyoshi; Ito, Yusuke; Yoshida, Izumi; Harada, Teppei; Mishima, Takashi; Fujita, Kazuhiro; Watai, Masatoshi [Japan Food Research Laboratories, Osaka 567-0085 (Japan); Nakagawa, Kiyotaka; Miyazawa, Teruo [Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Miyagi 981-8555 (Japan)

    2014-10-31

    Highlights: • Aculeatin promoted adipocyte differentiation. • Aculeatin improved glucose uptake. • Aculeatin enhanced adipocyte lipolysis. - Abstract: Toddalia asiatica (L.) Lam. (T. asiatica) has been utilized traditionally for medicinal purposes such as the treatment of diabetes. Currently, the extract is considered to be a good source of anti-diabetic agents, but the active compounds have yet to be identified. In this study, we investigated the effects of fractionated T. asiatica extracts on the differentiation of 3T3-L1 preadipocytes and identified aculeatin as a potential active agent. When 3T3-L1 preadipocytes were treated with aculeatin isolated from T. asiatica in the presence of insulin, aculeatin increased cellular triglyceride levels and glycerol-3-phosphate dehydrogenase activity. This indicated that aculeatin could enhance the differentiation of preadipocytes into adipocytes. Further analyses using a DNA microarray and real-time quantitative reverse-transcription PCR showed an increase in the expression of peroxisome proliferator-activated receptor-γ target genes (Pparg, Ap2, Cd36, Glut4 and Adipoq) by aculeatin, suggesting that aculeatin enhances the differentiation of 3T3-L1 cells by modulating the expression of genes critical for adipogenesis. Interestingly, after treatment of differentiated adipocytes with aculeatin, glucose uptake and lipolysis were enhanced. Overall, our results suggested that aculeatin is an active compound in T. asiatica for enhancing both differentiation and lipolysis of adipocytes, which are useful for the treatment of lipid abnormalities as well as diabetes.

  2. Tributyltin and triphenyltin exposure promotes in vitro adipogenic differentiation but alters the adipocyte phenotype in rainbow trout.

    Science.gov (United States)

    Lutfi, Esmail; Riera-Heredia, Natàlia; Córdoba, Marlon; Porte, Cinta; Gutiérrez, Joaquim; Capilla, Encarnación; Navarro, Isabel

    2017-07-01

    Numerous environmental pollutants have been identified as potential obesogenic compounds affecting endocrine signaling and lipid homeostasis. Among them, well-known organotins such as tributyltin (TBT) and triphenyltin (TPT), can be found in significant concentrations in aquatic environments. The aim of the present study was to investigate in vitro the effects of TBT and TPT on the development and lipid metabolism of rainbow trout (Onchorynchus mykiss) primary cultured adipocytes. Results showed that TBT and TPT induced lipid accumulation and slightly enhanced peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT enhancer binding protein alpha (C/EBPα) protein expression when compared to a control, both in the presence or absence of lipid mixture. However, the effects were higher when combined with lipid, and in the absence of it, the organotins did not cause complete mature adipocyte morphology. Regarding gene expression analyses, exposure to TBT and TPT caused an increase in fatty acid synthase (fasn) mRNA levels confirming the pro-adipogenic properties of these compounds. In addition, when added together with lipid, TBT and TPT significantly increased cebpa, tumor necrosis factor alpha (tnfa) and ATP-binding cassette transporter 1 (abca1) mRNA levels suggesting a synergistic effect. Overall, our data highlighted that TBT and TPT activate adipocyte differentiation in rainbow trout supporting an obesogenic role for these compounds, although by themselves they are not able to induce complete adipocyte development and maturation suggesting that these adipocytes might not be properly functional. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The effects of quercetin towards reactive oxygen species levels and glutathione in Toxoplasma gondii profilin-exposed adipocytes in vitro

    Directory of Open Access Journals (Sweden)

    Yulia D.S.

    2018-04-01

    Full Text Available Toxoplasma gondii (T. gondii has been found to potentially cause adipocyte dysfunction by activating the inflammatory pathways through its profilin. In response to inflammation, adipocytes produce Reactive Oxygen Species (ROS. To scavenge ROS, endogenous or exogenous antioxidants are required. Glutathione (GSH is one of enzimatic antioxidant that abundant in all of body cells. Quercetin, an exogenous antioxidant, can be widely found in natural products. This research aims to explore the effects of quercetin towards ROS and GSH stimulated from T. gondii profilin-exposed adipocytes. To achieve this, adipocytes were exposed to 20 µM T. gondii profilin and treated with four doses of quercetin; 31.25, 62.5, 125, and 250 µM. The results showed that quercetin significantly reduced the ROS levels (p <0,001 and significantly increased GSH (p <0,001 in T. gondii profilin-exposed adipocytes compared to untreated cells, with an effective dose of 62.5µM. This study implies that quercetin might be a promising candidate for development of antioxidant treatment interventions to prevent toxoplasmosis-mediated adipocytopathy.

  4. Nuclear factor of activated T cell (NFAT) transcription proteins regulate genes involved in adipocyte metabolism and lipolysis

    International Nuclear Information System (INIS)

    Holowachuk, Eugene W.

    2007-01-01

    NFAT involvement in adipocyte physiological processes was examined by treatment with CsA and/or GSK3β inhibitors (Li + or TZDZ-8), which prevent or increase NFAT nuclear translocation, respectively. CsA treatment reduced basal and TNFα-induced rates of lipolysis by 50%. Adipocytes preincubated with Li + or TZDZ-8 prior to CsA and/or TNFα, exhibited enhanced basal rates of lipolysis and complete inhibition of CsA-mediated decreased rates of lipolysis. CsA treatment dramatically reduced the mRNA levels of adipocyte-specific genes (aP2, HSL, PPARγ, ACS and Adn), compared with control or TNFα-treatment, whereas Li + pretreatment blocked the inhibitory effects of CsA, and mRNA levels of aP2, HSL, PPARγ, and ACS were found at or above control levels. NFAT nuclear localization, assessed by EMSA, confirmed that CsA or Li + treatments inhibited or increased NFAT nuclear translocation, respectively. These results show that NFAT proteins in mature adipocytes participate in the transcriptional control of genes involved in adipocyte metabolism and lipolysis

  5. Polychlorinated biphenyls (PCB 101, PCB 153 and PCB 180) alter leptin signaling and lipid metabolism in differentiated 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Ferrante, Maria C.; Amero, Paola; Santoro, Anna; Monnolo, Anna; Simeoli, Raffaele; Di Guida, Francesca; Mattace Raso, Giuseppina; Meli, Rosaria

    2014-01-01

    Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) are highly lipophilic environmental contaminants that accumulate in lipid-rich tissues, such as adipose tissue. Here, we reported the effects induced by PCBs 101, 153 and 180, three of the six NDL-PCBs defined as indicators, on mature 3T3-L1 adipocytes. We observed an increase in lipid content, in leptin gene expression and a reduction of leptin receptor expression and signaling, when cells were exposed to PCBs, alone or in combination. These modifications were consistent with the occurrence of “leptin-resistance” in adipose tissue, a typical metabolic alteration related to obesity. Therefore, we investigated how PCBs affect the expression of pivotal proteins involved in the signaling of leptin receptor. We evaluated the PCB effect on the intracellular pathway JAK/STAT, determining the phosphorylation of STAT3, a downstream activator of the transcription of leptin gene targets, and the expression of SOCS3 and PTP1B, two important regulators of leptin resistance. In particular, PCBs 153 and 180 or all PCB combinations induced a significant reduction in pSTAT3/STAT3 ratio and an increase in PTP1B and SOCS3, evidencing an additive effect. The impairment of leptin signaling was associated with the reduction of AMPK/ACC pathway activation, leading to the increase in lipid content. These pollutants were also able to increase the transcription of inflammatory cytokines (IL-6 and TNFα). It is worthy to note that the PCB concentrations used are comparable to levels detectable in human adipose tissue. Our data strongly support the hypothesis that NDL-PCBs may interfere with the lipid metabolism contributing to the development of obesity and related diseases. - Highlights: • NDL-PCBs alter lipid content and metabolism in 3T3-L1 adipocytes. • Impairment of leptin signaling was induced by NDL-PCBs. • NDL-PCBs reduce AMPK and ACC activation. • NDL-PCBs induce the synthesis of pro-inflammatory cytokine by

  6. Polychlorinated biphenyls (PCB 101, PCB 153 and PCB 180) alter leptin signaling and lipid metabolism in differentiated 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Ferrante, Maria C. [Department of Veterinary Medicine and Animal Productions, Federico II University of Naples, Via Delpino 1, 80137 Naples (Italy); Amero, Paola; Santoro, Anna [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Monnolo, Anna [Department of Veterinary Medicine and Animal Productions, Federico II University of Naples, Via Delpino 1, 80137 Naples (Italy); Simeoli, Raffaele; Di Guida, Francesca [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Mattace Raso, Giuseppina, E-mail: mattace@unina.it [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Meli, Rosaria, E-mail: meli@unina.it [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy)

    2014-09-15

    Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) are highly lipophilic environmental contaminants that accumulate in lipid-rich tissues, such as adipose tissue. Here, we reported the effects induced by PCBs 101, 153 and 180, three of the six NDL-PCBs defined as indicators, on mature 3T3-L1 adipocytes. We observed an increase in lipid content, in leptin gene expression and a reduction of leptin receptor expression and signaling, when cells were exposed to PCBs, alone or in combination. These modifications were consistent with the occurrence of “leptin-resistance” in adipose tissue, a typical metabolic alteration related to obesity. Therefore, we investigated how PCBs affect the expression of pivotal proteins involved in the signaling of leptin receptor. We evaluated the PCB effect on the intracellular pathway JAK/STAT, determining the phosphorylation of STAT3, a downstream activator of the transcription of leptin gene targets, and the expression of SOCS3 and PTP1B, two important regulators of leptin resistance. In particular, PCBs 153 and 180 or all PCB combinations induced a significant reduction in pSTAT3/STAT3 ratio and an increase in PTP1B and SOCS3, evidencing an additive effect. The impairment of leptin signaling was associated with the reduction of AMPK/ACC pathway activation, leading to the increase in lipid content. These pollutants were also able to increase the transcription of inflammatory cytokines (IL-6 and TNFα). It is worthy to note that the PCB concentrations used are comparable to levels detectable in human adipose tissue. Our data strongly support the hypothesis that NDL-PCBs may interfere with the lipid metabolism contributing to the development of obesity and related diseases. - Highlights: • NDL-PCBs alter lipid content and metabolism in 3T3-L1 adipocytes. • Impairment of leptin signaling was induced by NDL-PCBs. • NDL-PCBs reduce AMPK and ACC activation. • NDL-PCBs induce the synthesis of pro-inflammatory cytokine by

  7. Nebivolol stimulates mitochondrial biogenesis in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chenglin; Chen, Dongrui; Xie, Qihai [State Key Laboratory of Medical Genomics, Shanghai Key Laboratory of Vascular Biology, Department of Hypertension, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025 (China); Yang, Ying, E-mail: yangying_sh@yahoo.com [Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025 (China); Shen, Weili, E-mail: weili_shen@hotmail.com [State Key Laboratory of Medical Genomics, Shanghai Key Laboratory of Vascular Biology, Department of Hypertension, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025 (China)

    2013-08-16

    Highlights: •Nebivolol may act as a partial agonist of β3-adrenergic receptor (AR). •Nebivolol stimulates mitochondrial DNA replication and protein expression. •Nebivolol promotes mitochondrial synthesis via activation of eNOS by β3-AR. -- Abstract: Nebivolol is a third-generation β-adrenergic receptor (β-AR) blocker with additional beneficial effects, including the improvement of lipid and glucose metabolism in obese individuals. However, the underlying mechanism of nebivolol’s role in regulating the lipid profile remains largely unknown. In this study, we investigated the role of nebivolol in mitochondrial biogenesis in 3T3-L1 adipocytes. Exposure of 3T3-L1 cells to nebivolol for 24 h increased mitochondrial DNA copy number, mitochondrial protein levels and the expression of transcription factors involved in mitochondrial biogenesis, including PPAR-γ coactivator-1α (PGC-1α), Sirtuin 3 (Sirt3), mitochondrial transcription factor A (Tfam) and nuclear related factor 1 (Nrf1). These changes were accompanied by an increase in oxygen consumption and in the expression of genes involved in fatty acid oxidation and antioxidant enzymes in 3T3-L1 adipocytes, including nebivolol-induced endothelial nitric oxide synthase (eNOS), as well as an increase in the formation of cyclic guanosine monophosphate (cGMP). Pretreatment with NG-nitro-L-arginine methyl ester (l-NAME) attenuated nebivolol-induced mitochondrial biogenesis, as did the soluble guanylate cyclase inhibitor, ODQ. Treatment with nebivolol and β3-AR blocker SR59230A markedly attenuated PGC-1α, Sirt3 and manganese superoxide dismutase (MnSOD) protein levels in comparison to treatment with nebivolol alone. These data indicate that the mitochondrial synthesis and metabolism in adipocytes that is promoted by nebivolol is primarily mediated through the eNOS/cGMP-dependent pathway and is initiated by the activation of β3-AR receptors.

  8. Thiazolopyridines Improve Adipocyte Function by Inhibiting 11 Beta-HSD1 Oxoreductase Activity

    Directory of Open Access Journals (Sweden)

    Thirumurugan Rathinasabapathy

    2017-01-01

    Full Text Available Background. Glucocorticoid excess has been linked to clinical observations associated with the pathophysiology of metabolic syndrome. The intracellular glucocorticoid levels are primarily modulated by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1 enzyme that is highly expressed in key metabolic tissues including fat, liver, and the central nervous system. Methods. In this study we synthesized a set of novel tetrahydrothiazolopyridine derivatives, TR-01–4, that specifically target 11β-HSD1 and studied their ability to interfere with the glucocorticoid and lipid metabolism in the 3T3-L1 adipocytes. Results. Based on the docking model and structure-activity relationships, tetrahydrothiazolopyridine derivatives TR-02 and TR-04 showed the highest potency against 11β-HSD1 by dose-dependently inhibiting conversion of cortisone to cortisol (IC50 values of 1.8 μM and 0.095 μM, resp.. Incubation of fat cells with 0.1–10 μM TR-01–4 significantly decreased cortisone-induced lipid accumulation in adipocytes and suppressed 11β-HSD1 mRNA expression. Observed reduction in adipocyte fat stores could be partially explained by decreased expression levels of adipogenic markers (PPAR-γ, aP2 and key enzymes of lipid metabolism, including fatty acid synthase (FAS, hormone sensitive lipase (HSL, and lipoprotein lipase (LPL. Conclusions. The tetrahydrothiazolopyridine moiety served as an active pharmacophore for inhibiting 11β-HSD1 and offered a novel therapeutic strategy to ameliorate metabolic alterations found in obesity and diabetes.

  9. Conventional kinesin KIF5B mediates adiponectin secretion in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Ju, E-mail: juzi.cui@gmail.com [The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Beijing (China); Pang, Jing; Lin, Ya-Jun; Jiang, Ping; Gong, Huan [The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Beijing (China); Wang, Zai [Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing (China); Li, Jian; Cai, Jian-Ping [The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Beijing (China); Huang, Jian-Dong, E-mail: jdhuang@hku.hk [School of Biomedical Sciences and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Pokfulam (Hong Kong); The Centre for Synthetic Biology Engineering Research, Shenzhen Institutes of Advanced Technology, Shenzhen (China); Zhang, Tie-Mei, E-mail: tmzhang126@126.com [The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Beijing (China)

    2016-08-05

    Insulin stimulates adiponectin secretion and glucose transporter type 4 (GLUT4) translocation in adipocyte to regulate metabolism homeostasis. Similar to GLUT4 translocation, intracellular trafficking and release of adiponectin in adipocytes relies on the trans-Golgi network and endosomal system. Recent studies show that the heavy chain of conventional kinesin (KIF5B) mediates GLUT4 translocation in murine 3T3-L1 adipocytes, however, the motor machinery involved in mediating intracellular trafficking and release of adiponectin is unknown. Here, we examined the role of KIF5B in the regulation of adiponectin secretion. The KIF5B level was up-regulated during 3T3-L1 adipogenesis. This increase in cytosolic KIF5B was synchronized with the induction of adiponectin. Endogenous KIF5B and adiponectin were partially colocalized at the peri-nuclear and cytosolic regions. In addition, adiponectin-containing vesicles were co-immunoprecipitated with KIF5B. Knockdown of KIF5B resulted in a marked inhibition of adiponectin secretion and overexpression of KIF5B enhanced adiponectin release, whereas leptin secretion was not affected by changes in KIF5B expression. These data suggest that the secretion of adiponectin, but not leptin, is dependent on functional KIF5B. - Highlights: • The KIF5B level was up regulated during 3T3-L1 adipogenesis. • Endogenous KIF5B and adiponectin were partially colicalized. • Adiponectin-containing vesicles were co-immunoprecipitated with KIF5B. • The secretion of adiponectin, but not leptin, is dependent on functional KIF5B.

  10. Low ambient temperature during early postnatal development fails to cause a permanent induction of brown adipocytes

    Science.gov (United States)

    Chabowska-Kita, Agnieszka; Trabczynska, Anna; Korytko, Agnieszka; Kaczmarek, Monika M.; Kozak, Leslie P.

    2015-01-01

    The brown adipocyte phenotype (BAP) in white adipose tissue (WAT) is transiently induced in adult mammals in response to reduced ambient temperature. Since it is unknown whether a cold challenge can permanently induce brown adipocytes (BAs), we reared C57BL/6J (B6) and AxB8/PgJ (AxB8) mice at 17 or 29°C from birth to weaning, to assess the BAP in young and adult mice. Energy balance measurements showed that 17°C reduced fat mass in the preweaning mice by increasing energy expenditure and suppressed diet-induced obesity in adults. Microarray analysis of global gene expression of inguinal fat (ING) from 10-day-old (D) mice indicates that expression at 17°C vs. 29°C was not different. Between 10 and 21 days of age, the BAP was induced coincident with morphologic remodeling of ING and marked changes in expression of neural development genes (e.g., Akap 12 and Ngfr). Analyses of Ucp1 mRNA and protein showed that 17°C transiently increased the BAP in ING from 21D mice; however, BAs were unexpectedly present in mice reared at 29°C. The involution of the BAP in WAT occurred after weaning in mice reared at 23°C. Therefore, the capacity to stimulate thermogenically competent BAs in WAT is set by a temperature-independent, genetically controlled program between birth and weaning.—Chabowska-Kita, A., Trabczynska, A., Korytko, A., Kaczmarek, M. M., Kozak, L. P. Low ambient temperature during early postnatal development fails to cause a permanent induction of brown adipocytes. PMID:25896784

  11. Conventional kinesin KIF5B mediates adiponectin secretion in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Cui, Ju; Pang, Jing; Lin, Ya-Jun; Jiang, Ping; Gong, Huan; Wang, Zai; Li, Jian; Cai, Jian-Ping; Huang, Jian-Dong; Zhang, Tie-Mei

    2016-01-01

    Insulin stimulates adiponectin secretion and glucose transporter type 4 (GLUT4) translocation in adipocyte to regulate metabolism homeostasis. Similar to GLUT4 translocation, intracellular trafficking and release of adiponectin in adipocytes relies on the trans-Golgi network and endosomal system. Recent studies show that the heavy chain of conventional kinesin (KIF5B) mediates GLUT4 translocation in murine 3T3-L1 adipocytes, however, the motor machinery involved in mediating intracellular trafficking and release of adiponectin is unknown. Here, we examined the role of KIF5B in the regulation of adiponectin secretion. The KIF5B level was up-regulated during 3T3-L1 adipogenesis. This increase in cytosolic KIF5B was synchronized with the induction of adiponectin. Endogenous KIF5B and adiponectin were partially colocalized at the peri-nuclear and cytosolic regions. In addition, adiponectin-containing vesicles were co-immunoprecipitated with KIF5B. Knockdown of KIF5B resulted in a marked inhibition of adiponectin secretion and overexpression of KIF5B enhanced adiponectin release, whereas leptin secretion was not affected by changes in KIF5B expression. These data suggest that the secretion of adiponectin, but not leptin, is dependent on functional KIF5B. - Highlights: • The KIF5B level was up regulated during 3T3-L1 adipogenesis. • Endogenous KIF5B and adiponectin were partially colicalized. • Adiponectin-containing vesicles were co-immunoprecipitated with KIF5B. • The secretion of adiponectin, but not leptin, is dependent on functional KIF5B.

  12. Apoptosis inhibitor of macrophage (AIM) diminishes lipid droplet-coating proteins leading to lipolysis in adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Iwamura, Yoshihiro; Mori, Mayumi; Nakashima, Katsuhiko [Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mikami, Toshiyuki; Murayama, Katsuhisa [Genomic Science Laboratories, Dainippon Sumitomo Pharma Co. Ltd., 3-1-98 Kasugadenaka, Konohana-ku, Osaka 554-0022 (Japan); Arai, Satoko [Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Miyazaki, Toru, E-mail: tm@m.u-tokyo.ac.jp [Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer AIM induces lipolysis in a distinct manner from that of hormone-dependent lipolysis. Black-Right-Pointing-Pointer AIM ablates activity of peroxisome proliferator-activated receptor in adipocytes. Black-Right-Pointing-Pointer AIM reduces mRNA levels of lipid-droplet coating proteins leading to lipolysis. -- Abstract: Under fasting conditions, triacylglycerol in adipose tissue undergoes lipolysis to supply fatty acids as energy substrates. Such lipolysis is regulated by hormones, which activate lipases via stimulation of specific signalling cascades. We previously showed that macrophage-derived soluble protein, AIM induces obesity-associated lipolysis, triggering chronic inflammation in fat tissue which causes insulin resistance. However, the mechanism of how AIM mediates lipolysis remains unknown. Here we show that AIM induces lipolysis in a manner distinct from that of hormone-dependent lipolysis, without activation or augmentation of lipases. In vivo and in vitro, AIM did not enhance phosphorylation of hormone-sensitive lipase (HSL) in adipocytes, a hallmark of hormone-dependent lipolysis activation. Similarly, adipose tissue from obese AIM-deficient and wild-type mice showed comparable HSL phosphorylation. Consistent with the suppressive effect of AIM on fatty acid synthase activity, the amount of saturated and unsaturated fatty acids was reduced in adipocytes treated with AIM. This response ablated transcriptional activity of peroxisome proliferator-activated receptor (PPAR{gamma}), leading to diminished gene expression of lipid-droplet coating proteins including fat-specific protein 27 (FSP27) and Perilipin, which are indispensable for triacylglycerol storage in adipocytes. Accordingly, the lipolytic effect of AIM was overcome by a PPAR{gamma}-agonist or forced expression of FSP27, while it was synergized by a PPAR{gamma}-antagonist. Overall, distinct modes of lipolysis appear to take place in different physiological

  13. PPARγ ligand production is tightly linked to clonal expansion during initiation of adipocyte differentiation

    DEFF Research Database (Denmark)

    Hallenborg, Philip; Petersen, Rasmus Koefoed; Feddersen, Søren

    2014-01-01

    of differentiation. Concomitant with agonist production, murine fibroblasts undergo two rounds of mitosis referred to as mitotic clonal expansion. Here we show that mouse embryonic fibroblasts deficient in either of two cell cycle inhibitors, the transcription factor p53 or its target gene encoding the cyclin...... cycle inhibitory compounds decreased PPAR ligand production in differentiating 3T3-L1 preadipocytes. Furthermore, these inhibitors abolished the release of arachidonic acid induced by the hormonal cocktail initiating adipogenesis. Collectively, our results suggest that murine fibroblasts require clonal...... expansion for PPAR ligand production at the onset of adipocyte differentiation....

  14. Autocrine IGF-1 Action in Adipocytes Controls Systemic IGF-1 Concentrations and Growth

    OpenAIRE

    Kl?ting, Nora; Koch, Linda; Wunderlich, Thomas; Kern, Matthias; Ruschke, Karen; Krone, Wilhelm; Br?ning, Jens C.; Bl?her, Matthias

    2008-01-01

    OBJECTIVE?IGF-1 and the IGF-1 receptor (IGF-1R) have been implicated in the regulation of adipocyte differentiation and lipid accumulation in vitro. RESEARCH DESIGN AND METHODS?To investigate the role of IGF-1 receptor in vivo, we have inactivated the Igf-1r gene in adipose tissue (IGF-1RaP2Cre mice) using conditional gene targeting strategies. RESULTS?Conditional IGF-1R inactivation resulted in increased adipose tissue mass with a predominantly increased lipid accumulation in epigonadal fat ...

  15. Adipocytes Promote B16BL6 Melanoma Cell Invasion and the Epithelial-to-Mesenchymal Transition

    OpenAIRE

    Kushiro, Kyoko; Chu, Randy A.; Verma, Akanksha; Núñez, Nomelí P.

    2011-01-01

    Metastatic melanoma is one of the most deadly and evasive types of cancer. On average, cancer patients with metastatic melanoma survive only 6–9 months after diagnosis. Epidemiological and animal studies suggest that obesity increases the metastatic ability of malignant melanoma, though the mechanism is not known. In the present studies, we assessed the ability of 3T3L1 adipocytes to modulate B16BL6 melanoma cell invasion and the Epithelial-to-Mesenchymal Transition (EMT). For this purpose, w...

  16. The effects of Hot Pepper Extract and Capsaicin on Adipocyte Metabolism

    Directory of Open Access Journals (Sweden)

    Ching Sheng, Chu

    2008-03-01

    Full Text Available Objectives : The purpose of this study is to investigate the effects of hot pepper extract and capsaicin on the adipogenesis in 3T3-L1 cells, lipolysis in rat epididymal adipocytes and histological changes in porcine adipose tissue. Methods : Inhibiton of preadipocyte differentiation and/or stimulation of lipolysis play important roles in reducing obesity. 3T3-L1 preadipocytes were differentiated with adipogenic reagents by incubating for 3 days in the absence or presence of hot pepper extract or capsaicin ranging from 0.01 to 1㎎/㎖. The effects of hot pepper extract and capsaicin on adipogenesis were examined by measuring GPDH activity and by Oil Red O staining. Mature adipocytes from rat epididymal fat pad was incubated with hot pepper extract or capsaicin ranging from 0.01 to 1㎎/㎖ for 3 hrs. The effects of hot pepper extract and capsaicin on lipolysis were examined by measuring free glycerol released. Fat tissue from pig skin was injected with hot pepper extract or capsaicinCFP ranging from 0.1 to 10㎎/㎖ to examine the effects of hot pepper extract and capsaicin on histological changes under light microscopy. Results : The following results were obtained from present study on adipogenesis of preadipocytes, lipolysis of adipocytes and histological changes in fat tissue. 1. Hot pepper extract and capsaicin inhibited adipogenic differentiation at the concentration of 0.1 and 0.01㎎/㎖, respectively, indicating that capsaicin was more effective in inhibiting adipogenesis than hot pepper extract. 2. Hot pepper extract and capsaicin decreased the activity of glycerol-3-phosphate dehydrogenase(GPDH at the concentration of 0.1 and 0.01㎎/㎖, respectively, indicating that capsaicin was more effective in inhibiting adipogenic differentiation than hot pepper extract. 3. Hot pepper extract and capsaicin increased glycerol release at the concentration of 0.1㎎/㎖. There was no difference in lipolytic activity between hot pepper extract and

  17. Adipocyte Versus Pituitary Leptin in the Regulation of Pituitary Hormones: Somatotropes Develop Normally in the Absence of Circulating Leptin

    Science.gov (United States)

    Odle, Angela K.; Haney, Anessa; Allensworth-James, Melody; Akhter, Noor

    2014-01-01

    Leptin is a cytokine produced by white fat cells, skeletal muscle, the placenta, and the pituitary gland among other tissues. Best known for its role in regulating appetite and energy expenditure, leptin is produced largely by and in proportion to white fat cells. Leptin is also important to the maintenance and function of the GH cells of the pituitary. This was shown when the deletion of leptin receptors on somatotropes caused decreased numbers of GH cells, decreased circulating GH, and adult-onset obesity. To determine the source of leptin most vital to GH cells and other pituitary cell types, we compared two different leptin knockout models with Cre-lox technology. The global Lep-null model is like the ob/ob mouse, whereby only the entire exon 3 is deleted. The selective adipocyte-Lep-null model lacks adipocyte leptin but retains pituitary leptin, allowing us to investigate the pituitary as a potential source of circulating leptin. Male and female mice lacking adipocyte leptin (Adipocyte-lep-null) did not produce any detectable circulating leptin and were infertile, suggesting that the pituitary does not contribute to serum levels. In the presence of only pituitary leptin, however, these same mutants were able to maintain somatotrope numbers and GH mRNA levels. Serum GH trended low, but values were not significant. However, hypothalamic GHRH mRNA was significantly reduced in these animals. Other serum hormone and pituitary mRNA differences were observed, some of which varied from previous results reported in ob/ob animals. Whereas pituitary leptin is capable of maintaining somatotrope numbers and GH mRNA production, the decreased hypothalamic GHRH mRNA and low (but not significant) serum GH levels indicate an important role for adipocyte leptin in the regulation of GH secretion in the mouse. Thus, normal GH secretion may require the coordinated actions of both adipocyte and pituitary leptin. PMID:25116704

  18. Curcumin attenuates lipolysis stimulated by tumor necrosis factor-α or isoproterenol in 3T3-L1 adipocytes.

    Science.gov (United States)

    Xie, Xiao-yun; Kong, Po-Ren; Wu, Jin-feng; Li, Ying; Li, Yan-xiang

    2012-12-15

    Curcumin, an active component derived from dietary spice turmeric (Curcuma longa), has been demonstrated antihyperglycemic, antiinflammatory and hypocholesterolemic activities in obesity and diabetes. These effects are associated with decreased level of circulating free fatty acids (FFA), however the mechanism has not yet been elucidated. The flux of FFA and glycerol from adipose tissue to the blood stream primarily depends on the lipolysis of triacylglycerols in the adipocytes. Adipocyte lipolysis is physiologically stimulated by catecholamine hormones. Tumor necrosis factor-α (TNFα) stimulates chronic lipolysis in obesity and type 2 diabetes. In this study, we examined the role of curcumin in inhibiting lipolytic action upon various stimulations in 3T3-L1 adipocytes. Glycerol release from TNFα or isoproterenol-stimulated 3T3-L1 adipocytes in the absence or presence of curcumin was determined using a colorimetric assay (GPO-Trinder). Western blotting was used to investigate the TNFα-induced phosphorylation of MAPK and perilipin expression. Fatcake and cytosolic fractions were prepared to examine the isoproterenol-stimulated hormone-sensitive lipase translocation. Treatment with curcumin attenuated TNFα-mediated lipolysis by suppressing phosphorylation of extracellular signal-related kinase 1/2 (ERK1/2) and reversing the downregulation of perilipin protein in TNFα-stimulated adipocytes (p<0.05). The acute lipolytic response to adrenergic stimulation of isoproterenol was also restricted by curcumin (10-20 μM, p<0.05), which was compatible with reduced perilipin phosphorylation(29%, p<0.05) and hormone-sensitive lipase translocation(20%, p<0.05). This study provides evidence that curcumin acts on adipocytes to suppress the lipolysis response to TNFα and catecholamines. The antilipolytic effect could be a cellular basis for curcumin decreasing plasma FFA levels and improving insulin sensitivity. Copyright © 2012 Elsevier GmbH. All rights reserved.

  19. Trans-10, cis-12 conjugated linoleic acid decreases de novo lipid synthesis in human adipocytes

    DEFF Research Database (Denmark)

    Obsen, Thomas; Faergeman, Nils J; Chung, Soonkyu

    2012-01-01

    7-12 h, respectively. The mRNA levels of liver X receptor (LXR)α and sterol regulatory element binding protein (SREBP)-1c, transcription factors that regulate SCD-1, were decreased by 10,12 CLA within 5 h. These data suggest that the isomer-specific decrease in de novo lipid synthesis by 10,12 CLA......]-oleic or [(14)C]-linoleic acids. When using [(14)C]-acetic acid and [(14)C]-pyruvic acid as substrates, 30 μM 10,12 CLA, but not 9,11 CLA, decreased de novo synthesis of triglyceride, free FA, diacylglycerol, cholesterol esters, cardiolipin, phospholipids and ceramides within 3-24 h. Treatment with 30 μM 10...... is due, in part, to the rapid repression of lipogenic transcription factors that regulate MUFA synthesis, suggesting an anti-obesity mechanism unique to this trans FA....

  20. Effects of combination therapy using basic fibroblast growth factor and mature adipocyte-derived dedifferentiated fat (DFAT) cells on skin graft revascularisation.

    Science.gov (United States)

    Asami, Takashi; Soejima, Kazutaka; Kashimura, Tsutomu; Kazama, Tomohiko; Matsumoto, Taro; Morioka, Kosuke; Nakazawa, Hiroaki

    2015-01-01

    Although the benefits of basic fibroblast growth factor (bFGF) for wound healing and angiogenesis are well known, its effects on the process of skin graft revascularisation have not been clarified. It was hypothesised that bFGF would be beneficial to promote taking of skin grafts, but that the effect might be limited in the case of bFGF monotherapy. Therefore, this study investigated the efficacy of combination therapy using bFGF and dedifferentiated fat (DFAT) cells. DFAT cells have multilineage differentiation potential, including into endothelial cells, similar to the case of mesenchymal stem cells (MSC). Commercially available human recombinant bFGF was used. DFAT cells were prepared from SD strain rats as an adipocyte progenitor cell line from mature adipocytes. Full-thickness skin was lifted from the back of SD strain rats and then grafted back to the original wound site. Four groups were established prior to skin grafting: control group (skin graft alone), bFGF group (treated with bFGF), DFAT group (treated with DFAT cells), and combination group (treated with both bFGF and DFAT cells). Tissue specimens for histological examination were harvested 48 hours after grafting. The histological findings for the bFGF group showed vascular augmentation in the grafted dermis compared with the control group. However, the difference in the number of revascularised vessels per unit area did not reach statistical significance against the control group. In contrast, in the combination group, skin graft revascularisation was significantly promoted, especially in the upper dermis. The results suggest that replacement of the existing graft vessels was markedly promoted by the combination therapy using bFGF and DFAT cells, which may facilitate skin graft taking.

  1. Adenovirus Protein E4-ORF1 activation of PI3 kinase reveals differential regulation of downstream effector pathways in adipocytes

    OpenAIRE

    Chaudhary, Natasha; Gonzalez, Eva; Chang, Sung-Hee; Geng, Fuqiang; Rafii, Shahin; Altorki, Nasser K.; McGraw, Timothy E.

    2016-01-01

    Insulin activation of phosphatidylinositol 3-kinase (PI3K) regulates metabolism, including the translocation of the Glut4 glucose transporter to the plasma membrane and inactivation of the FoxO1 transcription factor. Adenoviral protein E4-ORF1 stimulates cellular glucose metabolism by mimicking growth-factor activation of PI3K. We have used E4-ORF1 as a tool to dissect PI3K-mediated signaling in adipocytes. E4-ORF1 activation of PI3K in adipocytes recapitulates insulin regulation of FoxO1 but...

  2. Adaptation of human adipose tissue to hypocaloric diet.

    Science.gov (United States)

    Rossmeislová, L; Mališová, L; Kračmerová, J; Štich, V

    2013-05-01

    Hypocaloric diet is a key component of the weight-reducing treatment of obesity and obesity-related disorders. Hypocaloric diets and the associated weight reduction promote improvement of metabolic profile of obese individuals. Among the mechanisms that underlie this beneficial metabolic outcome, the diet-induced modifications of morphological and functional characteristics of human adipose tissue (AT) are believed to have an important role. Prospective studies of hypocaloric weight-reducing dietary intervention demonstrate effects on adipocyte metabolism, namely lipolysis and lipogenesis, and associated changes of the adipocyte size. The endocrine function of AT, which involves cytokine and adipokine production by adipocytes, as well as by cells of stromavascular fraction, is also regulated by dietary intervention. Related inflammatory status of AT is modulated also as a consequence of the changes in recruitment of immune cells, mainly macrophages, in AT. Here, we give an overview of metabolic and endocrine modifications in human AT induced by a variety of hypocaloric diets.

  3. Induction of Adipocyte Differentiation by Polybrominated Diphenyl Ethers (PBDEs) in 3T3-L1 Cells

    Science.gov (United States)

    Tung, Emily W. Y.; Boudreau, Adèle; Wade, Michael G.; Atlas, Ella

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants that were extensively used in commercial products. PBDEs are ubiquitous environmental contaminants that are both lipophilic and bioaccumulative. Effects of PBDEs on adipogenesis were studied in the 3T3-L1 preadipocyte cell model in the presence and absence of a known adipogenic agent, dexamethasone (DEX). A PBDE mixture designed to mimic body burden of North Americans was tested, in addition to the technical mixture DE-71 and the individual congener BDE-47. The mixture, DE-71, and BDE-47 all induced adipocyte differentiation as assessed by markers for terminal differentiation [fatty acid binding protein 4 (aP2) and perilipin] and lipid accumulation. Characterization of the differentiation process in response to PBDEs indicated that adipogenesis induced by a minimally effective dose of DEX was enhanced by these PBDEs. Moreover, C/EBPα, PPARγ, and LXRα were induced late in the differentiation process. Taken together, these data indicate that adipocyte differentiation is induced by PBDEs; they act in the absence of glucocorticoid and enhance glucocorticoid-mediated adipogenesis. PMID:24722056

  4. Anti-Obesity Effects of Starter Fermented Kimchi on 3T3-L1 Adipocytes

    Science.gov (United States)

    Lee, Kyung-Hee; Song, Jia-Le; Park, Eui-Seong; Ju, Jaehyun; Kim, Hee-Young; Park, Kun-Young

    2015-01-01

    The anti-obesity effects of starter (Leuconostoc mesenteroides+Lactobacillus plantarum) fermented kimchi on 3T3-L1 adipocyte were studied using naturally fermented kimchi (NK), a functional kimchi (FK, NK supplemented with green tea), and FK supplemented with added starters (FKS). Oil red O staining and cellular levels of triglyceride (TG) and glycerol were used to evaluate the in vitro anti-obesity effects of these kimchis in 3T3-L1 cells. The expressions of adipogenesis/lipogenesis-related genes of peroxisome proliferator-active receptor (PPAR)-γ, CCAAT/enhance-binding protein (C/EBP)-α, and fatty acid synthase (FAS) were determined by RT-PCR. Kimchis, especially FKS, markedly decreased TG levels and increased levels of intracellular glycerol and lipid lipolysis. In addition, FKS also reduced the mRNA levels of PPAR-γ, C/EBP-α, and FAS, which are related to adipogenesis/lipogenesis in 3T3-L1 cells. These results suggest the anti-obesity effects of FKS were to due to enhanced lipolysis and reduced adipogenesis/lipogenesis in 3T3-L1 adipocytes. PMID:26770918

  5. Insulin affects the sodium affinity of the rat adipocyte (Na+,K+)-ATPase

    International Nuclear Information System (INIS)

    Lytton, J.

    1985-01-01

    The K0.5 for intracellular sodium of the two forms of (Na + ,K + )-ATPase which exist in rat adipocytes has been determined by incubating the cells in the absence of potassium in buffers of varying sodium concentration; these conditions shut off the Na + pump and allow sodium to equilibrate into the cell. The activity of (Na + ,K + )-ATPase was then monitored with 86 Rb + /K + pumping which was initiated by adding isotope and KCl to 5 mM, followed by a 3-min uptake period. Atomic absorption and 22 Na + tracer equilibration were used to determine the actual intracellular [Na + ] under the different conditions. The K0.5 values thus obtained were 17 mM for alpha and 52 mM for alpha(+). Insulin treatment of rat adipocytes had no effect on the intracellular [Na+] nor on the Vmax of 86 Rb + /K + pumping, but did produce a shift in the sodium ion K0.5 values to 14 mM for alpha and 33 mM for alpha(+). This change in affinity can explain the selective stimulation of alpha(+) by insulin under normal incubation conditions

  6. Digitonin abolishes free 2-deoxy-D-glucose accumulation in isolated rat adipocytes

    International Nuclear Information System (INIS)

    Thompson, K.; Kleinzeller, A.

    1986-01-01

    The hypothesis that accumulation against sizable chemical gradients of free (non-phosphorylated) 2-deoxy-D-glucose (2dGlc) in isolated rat adipocytes results from an intracellular compartmentation of free hexose was investigated. Cells exposed to 20 μg/ml digitonin for 10' demonstrated an increased plasma membrane permeability indexed by increased L-glucose entry rates and cellular (presumably cytosolic) protein and K + loss. Functional integrity of intracellular organelles was indicated by the ability of the cells to support ATP-driven 45 Ca 2+ -uptake. Equilibrium 3-O-methylglucose (3-O-MG, a non-accumulated hexose) levels were unaffected. These data suggest a specific permeabilizing action of digitonin at the plasma membrane having no effect on intracellular organelles or passively distributed solutes. Upon addition of digitonin, free 2dGlc fell from 66.5 +/- 8.9 to 7.4 +/- 2.3 pmol/10 5 cells, a value not significantly different from 3-O-MG levels. The gradient of 2dGlc-phosphate was also abolished, as was the increased steady-state free 2dGlc levels induced by insulin. The data argue against a compartmentation model as either the mechanism of adipocyte sugar accumulation or the basis of the steady-state free 2dGlc increase seen with insulin and suggest that an intact plasma membrane is essential to the process

  7. Diclofenac and triamcinolone acetonide impair tenocytic differentiation and promote adipocytic differentiation of mesenchymal stem cells.

    Science.gov (United States)

    Fredriksson, Maritha; Li, Yan; Stålman, Anders; Haldosén, Lars-Arne; Felländer-Tsai, Li

    2013-09-02

    Tendinopathies are often empirically treated with oral/topical nonsteroidal anti-inflammatory medications and corticosteroid injections despite their unclear effects on tendon regeneration. Recent studies indicate that tendon progenitors exhibit stem cell-like properties, i.e., differentiation to osteoblasts, adipocytes, and chondrocytes, in addition to tenocytes. Our present study aims at understanding the effects of triamcinolone acetonide and diclofenac on tenocytic differentiation of mesenchymal stem cells. The murine fibroblast C3H10T1/2 cell line was induced to tenocytic differentiation by growth differentiation factor-7. Cell proliferation and differentiation with the exposure of different concentrations of triamcinolone acetonide and diclofenac were measured by WST-1 assay and real-time polymerase chain reaction analysis, respectively. Cell proliferation was decreased in a concentration-dependent manner when exposed to triamcinolone acetonide and diclofenac. In addition to tenocytic differentiation, adipocyte formation was observed, both at gene expression and microscopic level, when the cells were exposed to triamcinolone acetonide or high concentrations of diclofenac. Our results indicate that triamcinolone acetonide and diclofenac might alter mesenchymal stem cell differentiation in a nonfavorable way regarding tendon regeneration; therefore, these medications should be used with more caution clinically.

  8. WEHI-3 cells inhibit adipocyte differentiation in 3T3-L1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Jing [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China); Liu, Gexiu [Institute of Hematology, School of Medicine, Jinan University, Guangzhou, Guangdong (China); Yan, Guoyao [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China); He, Dongmei [Institute of Hematology, School of Medicine, Jinan University, Guangzhou, Guangdong (China); Zhou, Ying [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China); Chen, Shengting, E-mail: shengtingchen@sina.cn [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China)

    2015-06-26

    By investigating the anti-adipogenic effects of WEHI-3 cells – a murine acute myelomonocytic leukemia cell line – we sought to improve the efficiency of hematopoietic stem cell transplantation (HSCT). Analysis of Oil Red O staining and the expression of adipogenic genes, including PPARγ, C/EBPα, FAS and LPL, indicated that WEHI-3 cells significantly inhibited 3T3-L1 mouse preadipocyte cells from differentiating into adipocytes. In vivo, fat vacuoles in mice injected with WEHI-3 cells were also remarkably reduced in the murine bone marrow pimelosis model. Moreover, the key gene in the Rho signaling pathway, ROCKII, and the key gene in the Wnt signaling pathway, β-catenin, were both upregulated compared with the control group. siRNA-mediated knockdown of ROCKII and β-catenin reversed these WEHI-3-mediated anti-adipogenic effects. Taken together, these data suggest that WEHI-3 cells exert anti-adipogenic effects and that both ROCKII and β-catenin are involved in this process. - Highlights: • WEHI-3, an acute myelomonocytic leukemia cell line, inhibited 3T3-L1 preadipocyte from differentiating into adipocyte. • WEHI-3 cells can arrest 3T3-L1 cells in G0/G1 phase by secreting soluble factors and thus inhibit their proliferation. • WEHI-3 cells reduced bone marrow pimelosis in the murine model. • Both ROCKII and β-catenin were involved in the WEHI-3-mediated anti-adipogenic effects.

  9. Insulin stimulates the tyrosine phosphorylation of a Mr = 160,000 glycoprotein in adipocyte plasma membranes

    International Nuclear Information System (INIS)

    Yu, K.T.; Khalaf, N.; Czech, M.P.

    1986-01-01

    In an attempt to identify putative substrates for the insulin receptor kinase, adipocyte plasma membranes were incubated with [γ- 32 P]ATP in the presence and absence of insulin. Insulin stimulates the tyrosine phosphorylation of its receptor β subunit but does not detectably alter the phosphorylation of other membrane proteins. In contrast, when plasma membranes from insulin-treated adipocytes are phosphorylated, the 32 P-labeling of a Mr=160,000 species (p160) and insulin receptor β subunit are markedly increased when compared to controls. p160 exhibits a rapid response (max. at 1 min) and high sensitivity (ED 50 = 2 x 10 -10 M) to insulin. The stimulatory effect of insulin on the phosphorylation of p160 is rapidly reversed following the addition of anti-insulin serum. Cold chase experiments indicate that insulin promotes the phosphorylation of p160 rather than inhibiting its dephosphorylation. p160 is a glycoprotein as evidenced by its adsorption to immobilized lectins and does not represent the insulin receptor precursor. The action of insulin on p160 tyrosine phosphorylation is mimicked by concanavalin A but not by EGF and other insulin-like agents such as hydrogen peroxide and vanadate. These results suggest that p160 tyrosine phosphorylation is an insulin receptor-mediated event and may participate in signalling by the insulin receptor

  10. Stabilization, not polymerization, of microtubules inhibits the nuclear translocation of STATs in adipocytes

    International Nuclear Information System (INIS)

    Gleason, Evanna L.; Hogan, Jessica C.; Stephens, Jacqueline M.

    2004-01-01

    Signal transducers and activators of transcriptions (STATs) are a family of latent transcription factors which are activated by a variety of growth factors and cytokines in many cell types. However, the mechanism by which these transcription factors translocate to the nucleus is poorly understood. The goal of this study was to determine the requirement of microfilaments and microtubules for cytokine induced STAT activation in cultured adipocytes. We used seven different actin-specific and microtubule-specific agents that are well-established effectors of these cytoskeletal networks. Our results clearly demonstrate that inhibition of microfilaments or the prevention of microtubule polymerization has no effect on the ability of STATs to be tyrosine phosphorylated or to translocate to the nucleus. However, we observed that paclitaxel, a microtubule stabilizer, resulted in a significant decrease in the nuclear translocation of STATs without affecting the cytosolic tyrosine phosphorylation of these transcription factors. In summary, our results demonstrate that the dynamic instability, but not the polymerization, of microtubules contributes to nuclear translocation of STAT proteins in adipocytes

  11. Adipokines, adiposity, and bone marrow adipocytes: Dangerous accomplices in multiple myeloma.

    Science.gov (United States)

    Morris, Emma V; Edwards, Claire M

    2018-06-26

    Obesity has become a global epidemic influencing the establishment and progression of a wide range of diseases, such as diabetes, cardiovascular disease, and cancer. In 2016, International Agency for Research on Cancer reported that obesity is now associated with 13 different cancers, one of which is multiple myeloma (MM), a destructive cancer of plasma cells that predominantly reside in the bone marrow. Obesity is the accumulation of excess body fat, which causes metabolic, endocrine, immunologic, and inflammatory-like changes. Obesity is usually associated with an increase in visceral and/or subcutaneous fat; however, an additional fat depot that also responds to diet-induced changes is bone marrow adipose tissue (BMAT). There have been several studies over the past few decades that have identified BMAT as a key driver in MM progression. Adipocytes secrete numerous adipokines, such as leptin, adiponectin, resistin, adipsin, and visfatin, which when secreted at normal controlled levels have protective properties. However, in obesity these levels of secretion change, coupled with an increase in adipocyte number and size causing a profound and lasting effect on the bone microenvironment, contributing to MM cell growth, survival, and migration as well as potentially fueling bone destruction. Obesity is a modifiable risk factor making it an attractive option for targeted therapy. This review discusses the link between obesity, monoclonal gammopathy of undetermined significance (a benign condition that precedes MM), and myeloma, and the contribution of key adipokines to disease establishment and progression. © 2018 Wiley Periodicals, Inc.

  12. 5-Lipoxygenase-Activating Protein as a Modulator of Olanzapine-Induced Lipid Accumulation in Adipocyte

    Directory of Open Access Journals (Sweden)

    Svetlana Dzitoyeva

    2013-01-01

    Full Text Available Experiments were performed in 3T3-L1 preadipocytes differentiated in vitro into adipocytes. Cells were treated with olanzapine and a 5-lipoxygenase (5-LOX activating protein (FLAP inhibitor MK-886. Lipid content was measured using an Oil Red O assay; 5-LOX and FLAP mRNA content was measured using quantitative real-time PCR; the corresponding protein contents were measured using quantitative Western blot assay. Olanzapine did not affect the cell content of 5-LOX mRNA and protein; it decreased FLAP mRNA and protein content at day five but not 24 hours after olanzapine addition. In the absence of MK-886, low concentrations of olanzapine increased lipid content only slightly, whereas a 56% increase was induced by 50 μM olanzapine. A 5-day cotreatment with 10 μM MK-886 potentiated the lipid increasing action of low concentrations of olanzapine. In contrast, in the presence of 50 μM olanzapine nanomolar and low micromolar concentrations of MK-886 reduced lipid content. These data suggest that FLAP system in adipocytes is affected by olanzapine and that it may modify how these cells respond to the second-generation antipsychotic drugs (SGADs. Clinical studies could evaluate whether the FLAP/5-LOX system could play a role in setting a variable individual susceptibility to the metabolic side effects of SGADs.

  13. Correlation between activation of PPAR¿ and resistin downregulation in a mouse adipocyte cell line by a series of thiazolidinediones.

    NARCIS (Netherlands)

    Sotiriou, A.; Blaauw, R.H.; Meijer, C.; Gijsbers, L.H.; Burg, van der B.; Vervoort, J.; Rietjens, I.M.C.M.

    2013-01-01

    The present study shows significant correlations between the EC50 for PPAR¿ activation in a reporter gene cell line and resistin downregulation in mouse adipocytes, and between the IC50 for resistin downregulation and the already published minimum effective dose for antihyperglycemic activity in a

  14. Curcumin inhibits adipogenesis in 3T3-L1 adipocytes and angiogenesis and obesity in C57/BL mice

    Science.gov (United States)

    The growth of new blood vessels or angiogenesis is necessary for the growth of adipose tissue. Dietary polyphenols may suppress growth of adipose tissue through their antiangiogenic activity and by modulating adipocyte metabolism. In the present study, we examined the effect of curcumin, a polyphen...

  15. Activation of peroxisome proliferator-activated receptor gamma bypasses the function of the retinoblastoma protein in adipocyte differentiation

    DEFF Research Database (Denmark)

    Hansen, Jacob B.; Petersen, R K; Larsen, B M

    1999-01-01

    The retinoblastoma protein (pRB) is an important regulator of development, proliferation, and cellular differentiation. pRB was recently shown to play a pivotal role in adipocyte differentiation, to interact physically with adipogenic CCAAT/enhancer-binding proteins (C/EBPs), and to positively...

  16. 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.

  17. Genome-wide profiling of transcription factor binding and epigenetic marks in adipocytes by ChIP-seq

    DEFF Research Database (Denmark)

    Nielsen, Ronni; Mandrup, Susanne

    2014-01-01

    of the most widely used of these technologies. Using these methods, association of transcription factors, cofactors, and epigenetic marks can be mapped to DNA in a genome-wide manner. Here, we provide a detailed protocol for performing ChIP-seq analyses in preadipocytes and adipocytes. We have focused mainly...

  18. Resistance to diet-induced adiposity in cannabinoid receptor-1 deficient mice is not due to impaired adipocyte function

    NARCIS (Netherlands)

    Oosterveer, Maaike H.; Koolman, Anniek H.; de Boer, Pieter T.; Bos, Trijnie; Bleeker, Aycha; Bloks, Vincent W.; Kuipers, Folkert; Sauer, Pieter J. J.; van Dijk, Gertjan

    2011-01-01

    Background: Overactivity and/or dysregulation of the endocannabinoid system (ECS) contribute to development of obesity. In vitro studies indicate a regulatory role for the cannabinoid receptor 1 (CB1) in adipocyte function and CB1-receptor deficient (CB1-/-) mice are resistant to high fat

  19. Alliin, a Garlic (Allium sativum Compound, Prevents LPS-Induced Inflammation in 3T3-L1 Adipocytes

    Directory of Open Access Journals (Sweden)

    Saray Quintero-Fabián

    2013-01-01

    Full Text Available Garlic (Allium sativum L. has been used to alleviate a variety of health problems due to its high content of organosulfur compounds and antioxidant activity. The main active component is alliin (S-allyl cysteine sulfoxide, a potent antioxidant with cardioprotective and neuroprotective actions. In addition, it helps to decrease serum levels of glucose, insulin, triglycerides, and uric acid, as well as insulin resistance, and reduces cytokine levels. However its potential anti-inflammatory effect is unknown. We examined the effects of alliin in lipopolysaccharide- (LPS- stimulated 3T3-L1 adipocytes by RT-PCR, Western blot, and microarrays analysis of 22,000 genes. Incubation of cells for 24 h with 100 μmol/L alliin prevented the increase in the expression of proinflammatory genes, IL-6, MCP-1, and Egr-1 in 3T3-L1 adipocytes exposed to 100 ng/mL LPS for 1 h. Interestingly, the phosphorylation of ERK1/2, which is involved in LPS-induced inflammation in adipocytes, was decreased following alliin treatment. Furthermore, the gene expression profile by microarrays evidentiate an upregulation of genes involved in immune response and downregulation of genes related with cancer. The present results have shown that alliin is able to suppress the LPS inflammatory signals by generating an anti-inflammatory gene expression profile and by modifying adipocyte metabolic profile.

  20. CUDC-907 Promotes Bone Marrow Adipocytic Differentiation Through Inhibition of Histone Deacetylase and Regulation of Cell Cycle

    DEFF Research Database (Denmark)

    Ali, Dalia; Alshammari, Hassan; Vishnubalaji, Radhakrishnan

    2017-01-01

    with quantitative polymerase chain reaction showed significant increase in H3K9ac epigenetic marker in the promoter regions of AdipoQ, FABP4, PPARγ, KLF15, and CEBPA in CUDC-907-treated hBMSCs. Follow-up experiments corroborated that the inhibition of histone deacetylase (HDAC) activity enhanced adipocytic...

  1. Associations of heart and adipocyte fatty acid-binding protein gene expression with intramuscular fat content in pigs

    NARCIS (Netherlands)

    Gerbens, F.; Verburg, F.J.; Moerkerk, van H.T.; Engel, B.; Buist, W.; Veerkamp, J.H.; Pas, te M.F.

    2001-01-01

    Intramuscular fat content is a major determinant of meat quality in pigs. Previously, polymorphisms in the adipocyte and heart fatty acid-binding protein genes, A-FABP and H-FABP, have been significantly associated with genetic variation of intramuscular fat content in a Duroc pig population.

  2. Associations of heart and adipocyte fatty acid-binding protein gene expression with intramuscular fat content in pigs.

    NARCIS (Netherlands)

    Gerbens, F.; Verburg, F.J.; Moerkerk, H.T.B. van; Engel, B.; Buist, W.; Veerkamp, J.H.; Pas, M.F. te

    2001-01-01

    Intramuscular fat content is a major determinant of meat quality in pigs. Previously, polymorphisms in the adipocyte and heart fatty acid-binding protein genes, A-FABP and H-FABP, have been significantly associated with genetic variation of intramuscular fat content in a Duroc pig population.

  3. Inhibition of 3T3-L1 adipocyte differentiation by expression of acyl-CoA-binding protein antisense RNA

    DEFF Research Database (Denmark)

    Mandrup, S; Sorensen, R V; Helledie, T

    1998-01-01

    Several lines of evidence have recently underscored the significance of fatty acids or fatty acid-derived metabolites as signaling molecules in adipocyte differentiation. The acyl-CoA-binding protein (ACBP), which functions as an intracellular acyl-CoA pool former and transporter, is induced duri...

  4. Transgenic rescue of adipocyte glucose-dependent insulinotropic polypeptide receptor expression restores high fat diet-induced body weight gain

    DEFF Research Database (Denmark)

    Ugleholdt, Randi; Pedersen, Jens; Bassi, Maria Rosaria

    2011-01-01

    that was similar between the groups. In contrast, glucose-dependent insulinotropic polypeptide-mediated insulin secretion does not seem to be important for regulation of body weight after high fat feeding. The study supports a role of the adipocyte GIPr in nutrient-dependent regulation of body weight and lean mass...

  5. Global transcriptome profiling identifies KLF15 and SLC25A10 as modifiers of adipocytes insulin sensitivity in obese women.

    Directory of Open Access Journals (Sweden)

    Agné Kulyté

    Full Text Available Although the mechanisms linking obesity to insulin resistance (IR and type 2 diabetes (T2D are not entirely understood, it is likely that alterations of adipose tissue function are involved. The aim of this study was to identify new genes controlling insulin sensitivity in adipocytes from obese women with either insulin resistant (OIR or sensitive (OIS adipocytes. Insulin sensitivity was first determined by measuring lipogenesis in isolated adipocytes from abdominal subcutaneous white adipose tissue (WAT in a large observational study. Lipogenesis was measured under conditions where glucose transport was the rate limiting step and reflects in vivo insulin sensitivity. We then performed microarray-based transcriptome profiling on subcutaneous WAT specimen from a subgroup of 9 lean, 21 OIS and 18 obese OIR women. We could identify 432 genes that were differentially expressed between the OIR and OIS group (FDR ≤5%. These genes are enriched in pathways related to glucose and amino acid metabolism, cellular respiration, and insulin signaling, and include genes such as SLC2A4, AKT2, as well as genes coding for enzymes in the mitochondria respiratory chain. Two IR-associated genes, KLF15 encoding a transcription factor and SLC25A10 encoding a dicarboxylate carrier, were selected for functional evaluation in adipocytes differentiated in vitro. Knockdown of KLF15 and SLC25A10 using siRNA inhibited insulin-stimulated lipogenesis in adipocytes. Transcriptome profiling of siRNA-treated cells suggested that KLF15 might control insulin sensitivity by influencing expression of PPARG, PXMP2, AQP7, LPL and genes in the mitochondrial respiratory chain. Knockdown of SLC25A10 had only modest impact on the transcriptome, suggesting that it might directly influence insulin sensitivity in adipocytes independently of transcription due to its important role in fatty acid synthesis. In summary, this study identifies novel genes associated with insulin sensitivity in

  6. Separate Developmental Programs for HLA-A and -B Cell Surface Expression during Differentiation from Embryonic Stem Cells to Lymphocytes, Adipocytes and Osteoblasts

    DEFF Research Database (Denmark)

    Sabir, Hardee J; Nehlin, Jan O; Qanie, Diyako

    2013-01-01

    -A, but not -B) is seen on some multipotent stem cells, and this raises the question how this is in other stem cells and how it changes during differentiation. In this study, we have used flow cytometry to investigate the cell surface expression of HLA-A and -B on human embryonic stem cells (hESC), human...... hematopoietic stem cells (hHSC), human mesenchymal stem cells (hMSC) and their fully-differentiated progenies such as lymphocytes, adipocytes and osteoblasts. hESC showed extremely low levels of HLA-A and no -B. In contrast, multipotent hMSC and hHSC generally expressed higher levels of HLA-A and clearly HLA......A major problem of allogeneic stem cell therapy is immunologically mediated graft rejection. HLA class I A, B, and Cw antigens are crucial factors, but little is known of their respective expression on stem cells and their progenies. We have recently shown that locus-specific expression (HLA...

  7. Distinct Effects of Adipose-Derived Stem Cells and Adipocytes on Normal and Cancer Cell Hierarchy.

    Science.gov (United States)

    Anjanappa, Manjushree; Burnett, Riesa; Zieger, Michael A; Merfeld-Clauss, Stephanie; Wooden, William; March, Keith; Tholpady, Sunil; Nakshatri, Harikrishna

    2016-07-01

    Adipose-derived stem cells (ASC) have received considerable attention in oncology because of the known direct link between obesity and cancer as well as the use of ASCs in reconstructive surgery after tumor ablation. Previous studies have documented how cancer cells commandeer ASCs to support their survival by altering extracellular matrix composition and stiffness, migration, and metastasis. This study focused on delineating the effects of ASCs and adipocytes on the self-renewal of stem/progenitor cells and hierarchy of breast epithelial cells. The immortalized breast epithelial cell line MCF10A, ductal carcinoma in situ (DCIS) cell lines MCF10DCIS.com and SUM225, and MCF10A-overexpressing SRC oncogene were examined using a mammosphere assay and flow cytometry for the effects of ASCs on their self-renewal and stem-luminal progenitor-differentiated cell surface marker profiles. Interestingly, ASCs promoted the self-renewal of all cell types except SUM225. ASC coculture or treatment with ASC conditioned media altered the number of CD49f(high)/EpCAM(low) basal/stem-like and CD49f(medium)/EpCAM(medium) luminal progenitor cells. Among multiple factors secreted by ASCs, IFNγ and hepatocyte growth factor (HGF) displayed unique actions on epithelial cell hierarchy. IFNγ increased stem/progenitor-like cells while simultaneously reducing the size of mammospheres, whereas HGF increased the size of mammospheres with an accompanying increase in luminal progenitor cells. ASCs expressed higher levels of HGF, whereas adipocytes expressed higher levels of IFNγ. As luminal progenitor cells are believed to be prone for transformation, IFNγ and HGF expression status of ASCs may influence susceptibility for developing breast cancer as well as on outcomes of autologous fat transplantation on residual/dormant tumor cells. This study suggests that the ratio of ASCs to adipocytes influences cancer cell hierarchy, which may impact incidence and progression. Mol Cancer Res; 14(7); 660

  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. Bixin regulates mRNA expression involved in adipogenesis and enhances insulin sensitivity in 3T3-L1 adipocytes through PPAR{gamma} activation

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Nobuyuki; Goto, Tsuyoshi; Taimatsu, Aki; Egawa, Kahori; Katoh, Sota; Kusudo, Tatsuya; Sakamoto, Tomoya; Ohyane, Chie; Lee, Joo-Young; Kim, Young-il; Uemura, Taku; Hirai, Shizuka [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Kawada, Teruo, E-mail: fat@kais.kyoto-u.ac.jp [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan)

    2009-12-25

    Insulin resistance is partly due to suppression of insulin-induced glucose uptake into adipocytes. The uptake is dependent on adipocyte differentiation, which is controlled at mRNA transcription level. The peroxisome proliferator-activated receptor (PPAR), a ligand-regulated nuclear receptor, is involved in the differentiation. Many food-derived compounds serve as ligands to activate or inactivate PPAR. In this study, we demonstrated that bixin and norbixin (annatto extracts) activate PPAR{gamma} by luciferase reporter assay using GAL4-PPAR chimera proteins. To examine the effects of bixin on adipocytes, 3T3-L1 adipocytes were treated with bixin or norbixin. The treatment induced mRNA expression of PPAR{gamma} target genes such as adipocyte-specific fatty acid-binding protein (aP2), lipoprotein lipase (LPL), and adiponectin in differentiated 3T3-L1 adipocytes and enhanced insulin-dependent glucose uptake. The observations indicate that bixin acts as an agonist of PPAR{gamma} and enhances insulin sensitivity in 3T3-L1 adipocytes, suggesting that bixin is a valuable food-derived compound as a PPAR ligand to regulate lipid metabolism and to ameliorate metabolic syndrome.

  10. Preliminary Study on the Effect of Adipocytes on the Biological Behaviors of
Lung Adenocarcinoma A549 Cells in Tumor Microenvironment

    Directory of Open Access Journals (Sweden)

    Hang ZHANG

    2018-05-01

    Full Text Available Background and objective Adipocytes in the tumor microenvironment may provide the metabolic fuel or signal transduction through media and other means to promote a variety of malignant proliferation and invasion, of tumor cells, but their role in lung cancer progression is still unclear. The purpose of this study was to investigate the effect of adipocytes on lung cancer cell biology. Methods 3T3-L1 pre-adipocytes were induced into mature adipocytes. The cell morphology was observed by microscopy and Oil Red O staining. MTT assay, colony formation assay, wound-healing and Transwell methods were used to detect lung cancer cell proliferation, migration and invasion ability. The content of triglyceride in cells was determined by colorimetry. Results The morphology of lung adenocarcinoma A549 cells became more slender after co-culture with mature adipocytes, and the proliferation and cloning ability were significantly enhanced (P<0.05. In addition, mature adipocytes can also promote the migration ability (P<0.05, invasion ability (P<0.01 and accumulation of intracellular lipid (P<0.05 of A549 cells. Conclusion These findings suggested that adipocytes in tumor microenvironment can promote the proliferation, migration and invasion of lung adenocarcinoma A549 cells, which may be related to lipid metabolism.

  11. The Regulation of Chemerin and CMKLR1 Genes Expression by TNF-α, Adiponectin, and Chemerin Analog in Bovine Differentiated Adipocytes

    Directory of Open Access Journals (Sweden)

    Y. Suzuki

    2012-09-01

    Full Text Available Adipokines, adipocyte-derived protein, have important roles in various kinds of physiology including energy homeostasis. Chemerin, one of adipocyte-derived adipokines, is highly expressed in differentiated adipocytes and is known to induce macrophage chemotaxis and glucose intolerance. The objective of the present study was to investigate the changes of chemerin and the chemokine-like-receptor 1 (CMKLR1 gene expression levels during differentiation of the bovine adipocyte and in differentiated adipocytes treated with tumor necrosis factor-α (TNF-α, adiponectin, leptin, and chemerin (peptide analog. The expression levels of the chemerin gene increased at d 6 and 12 of the differentiation period accompanied by increased cytoplasm lipid droplets. From d 6 onward, peroxisome proliferator-activated receptor-γ2 (PPAR-γ2 gene expression levels were significantly higher than that of d 0 and 3. In contrast, CMKLR1 expression levels decreased at the end of the differentiation period. In fully differentiated adipocytes (i.e. at d 12, the treatment of TNF-α and adiponectin upregulated both chemerin and CMKLR1 gene expression levels, although leptin did not show such effects. Moreover, chemerin analog treatment was shown to upregulate chemerin gene expression levels regardless of doses. These results suggest that the expression of chemerin in bovine adipocyte might be regulated by chemerin itself and other adipokines, which indicates its possible role in modulating the adipokine secretions in adipose tissues.

  12. Insulin-stimulated conversion of D-[5-3H] glucose to 3HOH in the perifused isolated rat adipocyte

    International Nuclear Information System (INIS)

    Duckworth, W.C.; Peavy, D.E.; Frechette, P.; Solomon, S.S.

    1986-01-01

    Characteristics of basal and insulin-stimulated glucose utilization by perifused adipocytes have been investigated by measuring the formation of 3 HOH from D-(5- 3 H) glucose. At a glucose concentration of 0.55 mmol/L, basal glucose utilization ranged from 0.5 to 1.0 nmol/min/10(6) cells. Perifused adipocytes showed a maximal response to insulin of a threefold to fourfold increase in the conversion of (5- 3 H) glucose to 3 HOH with a half-maximal response at an insulin concentration of 20 microU/mL. The response to insulin was blocked by phlorizin and cytochalasin B, competitive inhibitors of glucose transport, consistent with an effect of insulin on glucose transport. Insulin increased the Vmax for glucose metabolism but had no effect on the apparent affinity for glucose utilization. The characteristics of glucose utilization and the stimulation of glucose metabolism by insulin in the perifused adipocyte are therefore similar to characteristics previously observed with incubated adipocytes. Because insulin can readily be removed from the system, perifused adipocytes are especially suited for studying the termination of insulin action. The termination of insulin-stimulated glucose metabolism occurred at the same rate in the presence of tracer (1 nmol/L) (5- 3 H)-glucose alone as when 0.55 mmol/L glucose or 2 mmol/L pyruvate were added to the perifusion buffer. The halftime for this process in both cases was approximately 40 minutes. These data suggest that the presence of metabolizable substrate is not required for the termination of the insulin response, but the time course suggests that termination requires more than simply insulin-receptor dissociation

  13. Insulin and adenosine regulate the phosphatidylcholine concentration in isolated rat adipocyte plasma membranes.

    Science.gov (United States)

    Kiechle, F L; Sykes, E; Artiss, J D

    1995-01-01

    Blockade of adenosine receptors by 3-isobutyl-1-methylxanthine or degradation of endogenous adenosine with adenosine deaminase increased the phosphatidylcholine concentration in isolated rat adipocyte plasma membranes, an effect which was suppressed by the phosphatidylethanolamine methyltransferase inhibitor, S-adenosyl-L-homocysteine, and reversed by the adenosine analogue, N6-(L-phenylisopropyl)-adenosine. For example, the addition of N6-(L-phenylisopropyl)-adenosine to adenosine deaminase pretreated plasma membranes rapidly lowered the concentration of phosphatidylcholine by 171 nmol/mg at 30 seconds compared to control. Insulin-induced stimulation of phospholipid methylation in membranes treated with 3-isobutyl-1-methylxanthine or adenosine deaminase was achieved only after the addition of N6-(L-phenylisopropyl)-adenosine. These results suggest that adenosine receptor occupancy inhibits phospholipid methylation, is required for insulin stimulation of phospholipid methylation, and may perhaps activate a phosphatidylcholine-specific phospholipase C or phospholipase D.

  14. MDM2 facilitates adipocyte differentiation through CRTC-mediated activation of STAT3

    DEFF Research Database (Denmark)

    Hallenborg, P.; Siersbæk, M.; Barrio-Hernandez, I.

    2016-01-01

    on activation of the STAT family of transcription factors. Their activation was required for the cAMP-mediated induction of target genes. Interestingly, rather than influencing all cAMP-stimulated genes, inhibition of the kinases directly responsible for STAT activation, namely JAKs, or ablation of MDM2, each......The ubiquitin ligase MDM2 is best known for balancing the activity of the tumor suppressor p53. We have previously shown that MDM2 is vital for adipocyte conversion through controlling Cebpd expression in a p53-independent manner. Here, we show that the proadipogenic effect of MDM2 relies...... resulted in abolished induction of a subset of cAMP-stimulated genes, with Cebpd being among the most affected. Moreover, STATs were able to interact with the transcriptional cofactors CRTC2 and CRTC3, hitherto only reported to associate with the cAMP-responsive transcription factor CREB. Last...

  15. The Role of Nrf2: Adipocyte Differentiation, Obesity, and Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Hyun-Ae Seo

    2013-01-01

    Full Text Available Metabolic diseases, such as type 2 diabetes and obesity, are increasing globally, and much work has been performed to elucidate the regulatory mechanisms of these diseases. Nuclear factor E2-related factor 2 (Nrf2 is a basic leucine zipper transcription factor that serves as a primary cellular defense against the cytotoxic effects of oxidative stress. Recent studies have proposed a close relationship between oxidative stress and energy metabolism-associated disease. The Nrf2 pathway, as a master regulator of cellular defense against oxidative stress, has emerged as a critical target of energy metabolism; however, its effects are controversial. This review examines the current state of research on the role of Nrf2 on energy metabolism, specifically with respect to its participation in adipocyte differentiation, obesity, and insulin resistance, and discusses the possibility of using Nrf2 as a therapeutic target in the clinic.

  16. Inhibition of adipocyte differentiation by resistin-like molecule alpha. Biochemical characterization of its oligomeric nature

    DEFF Research Database (Denmark)

    Blagoev, Blagoy; Kratchmarova, Irina; Nielsen, Mogens M

    2002-01-01

    A novel family of cysteine-rich secreted proteins with unique tissue distribution has recently been identified. One of the members, resistin (for "resistance to insulin"), also called FIZZ3, was identified in a screen for molecules that are down-regulated in mature adipocytes upon administration...... of thiazolidinediones. The prototypical member of this family was originally identified from bronchoalveolar lavage fluid of inflamed lungs and designated FIZZ1 ("found in inflammatory zone"). This molecule was also found to be highly expressed in adipose tissue and was named resistin-like molecule alpha (RELMalpha...... as well as by mass spectrometry. In addition, RELMalpha is able to form heterooligomers with resistin but not RELMbeta. Since RELMalpha is expressed by adipose tissue and it is a secreted factor, our findings suggest that RELMalpha may be involved in the control of the adipogenesis as well...

  17. Epidermis-type lipoxygenase 3 regulates adipocyte differentiation and peroxisome proliferator-activated receptor gamma activity

    DEFF Research Database (Denmark)

    Hallenborg, Philip; Jørgensen, Claus; Petersen, Rasmus K

    2010-01-01

    preadipocytes. Here, we show that forced expression of eLOX3 or addition of eLOX3 products stimulated adipogenesis under conditions that normally require an exogenous PPAR gamma ligand for differentiation. Hepoxilins, a group of oxidized arachidonic acid derivatives produced by eLOX3, bound to and activated...... PPAR gamma. Production of hepoxilins was increased transiently during the initial stages of adipogenesis. Furthermore, small interfering RNA-mediated or retroviral short hairpin RNA-mediated knockdown of eLOX3 expression abolished differentiation of 3T3-L1 preadipocytes. Finally, we demonstrate...... differentiation has remained enigmatic. Previously, we showed that lipoxygenase (LOX) activity is involved in activation of PPAR gamma during the early stages of adipocyte differentiation. Of the seven known murine LOXs, only the unconventional LOX epidermis-type lipoxygenase 3 (eLOX3) is expressed in 3T3-L1...

  18. Physiological and biochemical characteristics of adrenergic receptors and pathways in brown adipocytes

    Science.gov (United States)

    Horwitz, B. A.

    1975-01-01

    Mechanisms involved in the thermogenic response of brown adipose tissue (BAT) to sympathetic nervous stimulation (e.g., by cold exposure) and to norepinephrine (NE) release are investigated. Three effects appear to play a role in the increased oxygen consumption (and heat production) of the adipocytes: increased membrane permeability, activation of the beta-adrenergic pathway, and enhancement of Na(+)/K(+) membrane pump activity. Increased passive influx of Na(+) and efflux of K(+) due to greater permeability raise the energy demands of the Na/K pump; the pump is also stimulated by increased cyclic AMP synthesis resulting from activation by NE of membrane-bound adenyl cyclase. Studies with inhibitors such as propanolol, phentolamine, and ouabain support this hypothesis.

  19. The endocrine disruptor diethylstilbestrol induces adipocyte differentiation and promotes obesity in mice

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Chan-Juan; Cheng, Xue-Jia; Xia, Hong-Fei, E-mail: hongfeixia@yahoo.com.cn; Ma, Xu

    2012-08-15

    Epidemiology studies indicate that exposure to endocrine disruptors during developmental “window” contributes to adipogenesis and the development of obesity. Implication of endocrine disruptor such as diethylstilbestrol (DES) on adipose tissue development has been poorly investigated. Here we evaluated the effects of DES on adipocyte differentiation in vitro and in vivo, and explored potential mechanism involved in its action. DES induced 3T3-L1 preadipocyte differentiation in a dose-dependent manner, and activated the expression of estrogen receptor (ER) and peroxisome proliferator-acivated receptor (PPAR) γ as well as its target genes required for adipogenesis in vitro. ER mediated the enhancement of DES-induced PPARγ activity. Moreover, DES perturbed key regulators of adipogenesis and lipogenic pathway in vivo. In utero exposure to low dose of DES significantly increased body weight, liver weight and fat mass in female offspring at postnatal day (PND) 60. In addition, serum triglyceride and glucose levels were also significantly elevated. These results suggest that perinatal exposure to DES may be expected to increase the incidence of obesity in a sex-dependent manner and can act as a potential chemical stressor for obesity and obesity-related disorders. -- Highlights: ► DES induced adipocyte differentiation in a dose-dependent manner in 3T3-L1 cells. ► DES activated adipogenic critical regulators and markers in vitro and in vivo. ► Perinatal exposure to DES led to the obese phenotype in female offspring. ► DES might be a potential chemical stressor for obesity and obesity-related disorders.

  20. Retinoic acid receptor signalling directly regulates osteoblast and adipocyte differentiation from mesenchymal progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Green, A.C. [St Vincent' s Institute, Fitzroy, Victoria 3065 (Australia); Department of Medicine at St. Vincent' s Hospital, The University of Melbourne, Victoria 3065 (Australia); Kocovski, P.; Jovic, T.; Walia, M.K. [St Vincent' s Institute, Fitzroy, Victoria 3065 (Australia); Chandraratna, R.A.S. [IO Therapeutics, Inc., Santa Ana, CA 92705 (United States); Martin, T.J.; Baker, E.K. [St Vincent' s Institute, Fitzroy, Victoria 3065 (Australia); Department of Medicine at St. Vincent' s Hospital, The University of Melbourne, Victoria 3065 (Australia); Purton, L.E., E-mail: lpurton@svi.edu.au [St Vincent' s Institute, Fitzroy, Victoria 3065 (Australia); Department of Medicine at St. Vincent' s Hospital, The University of Melbourne, Victoria 3065 (Australia)

    2017-01-01

    Low and high serum retinol levels are associated with increased fracture risk and poor bone health. We recently showed retinoic acid receptors (RARs) are negative regulators of osteoclastogenesis. Here we show RARs are also negative regulators of osteoblast and adipocyte differentiation. The pan-RAR agonist, all-trans retinoic acid (ATRA), directly inhibited differentiation and mineralisation of early osteoprogenitors and impaired the differentiation of more mature osteoblast populations. In contrast, the pan-RAR antagonist, IRX4310, accelerated differentiation of early osteoprogenitors. These effects predominantly occurred via RARγ and were further enhanced by an RARα agonist or antagonist, respectively. RAR agonists similarly impaired adipogenesis in osteogenic cultures. RAR agonist treatment resulted in significant upregulation of the Wnt antagonist, Sfrp4. This accompanied reduced nuclear and cytosolic β-catenin protein and reduced expression of the Wnt target gene Axin2, suggesting impaired Wnt/β-catenin signalling. To determine the effect of RAR inhibition in post-natal mice, IRX4310 was administered to male mice for 10 days and bones were assessed by µCT. No change to trabecular bone volume was observed, however, radial bone growth was impaired. These studies show RARs directly influence osteoblast and adipocyte formation from mesenchymal cells, and inhibition of RAR signalling in vivo impairs radial bone growth in post-natal mice. - Graphical abstract: Schematic shows RAR ligand regulation of osteoblast differentiation in vitro. RARγ antagonists±RARα antagonists promote osteoblast differentiation. RARγ and RARα agonists alone or in combination block osteoblast differentiation, which correlates with upregulation of Sfrp4, and downregulation of nuclear and cytosolic β-catenin and reduced expression of the Wnt target gene Axin2. Red arrows indicate effects of RAR agonists on mediators of Wnt signalling.

  1. The endocrine disruptor diethylstilbestrol induces adipocyte differentiation and promotes obesity in mice

    International Nuclear Information System (INIS)

    Hao, Chan-Juan; Cheng, Xue-Jia; Xia, Hong-Fei; Ma, Xu

    2012-01-01

    Epidemiology studies indicate that exposure to endocrine disruptors during developmental “window” contributes to adipogenesis and the development of obesity. Implication of endocrine disruptor such as diethylstilbestrol (DES) on adipose tissue development has been poorly investigated. Here we evaluated the effects of DES on adipocyte differentiation in vitro and in vivo, and explored potential mechanism involved in its action. DES induced 3T3-L1 preadipocyte differentiation in a dose-dependent manner, and activated the expression of estrogen receptor (ER) and peroxisome proliferator-acivated receptor (PPAR) γ as well as its target genes required for adipogenesis in vitro. ER mediated the enhancement of DES-induced PPARγ activity. Moreover, DES perturbed key regulators of adipogenesis and lipogenic pathway in vivo. In utero exposure to low dose of DES significantly increased body weight, liver weight and fat mass in female offspring at postnatal day (PND) 60. In addition, serum triglyceride and glucose levels were also significantly elevated. These results suggest that perinatal exposure to DES may be expected to increase the incidence of obesity in a sex-dependent manner and can act as a potential chemical stressor for obesity and obesity-related disorders. -- Highlights: ► DES induced adipocyte differentiation in a dose-dependent manner in 3T3-L1 cells. ► DES activated adipogenic critical regulators and markers in vitro and in vivo. ► Perinatal exposure to DES led to the obese phenotype in female offspring. ► DES might be a potential chemical stressor for obesity and obesity-related disorders.

  2. Triiodothyronine modulates the expression of leptin and adiponectin in 3T3-L1 adipocytes.

    Science.gov (United States)

    Oliveira, Miriane de; de Síbio, Maria Teresa; Olimpio, Regiane Marques Castro; Moretto, Fernanda Cristina Fontes; Luvizotto, Renata de Azevedo Melo; Nogueira, Celia Regina

    2015-01-01

    To study the effect of different doses of triiodothyronine on gene expression of the adipokines leptin and adiponectin, at different times, and to evaluate the difference in expression between the two adipokines in each group. 3T3-L1 adipocytes were incubated with triiodothyronine at physiological dose (10nM) and supraphysiological doses (100nM or 1,000nM), or without triiodothyronine (control, C) for 0.5, 6, or 24 hours. Leptin and adiponectin mRNA was detected using real-time polymerase chain reaction (RT-PCR). One-way analyses of variance, Tukey's test or Student's t test, were used to analyze data, and significance level was set at 5%. Leptin levels decreased in the 1,000nM-dose group after 0.5 hour. Adiponectin levels dropped in the 10nM-dose group, but increased at the 100nM dose. After 6 hours, both genes were suppressed in all hormone concentrations. After 24 hours, leptin levels increased at 10, 100 and 1,000nM groups as compared to the control group; and adiponectin levels increased only in the 100nM group as compared to the control group. These results demonstrated fast actions of triiodothyronine on the leptin and adiponectin expression, starting at 0.5 hour, at a dose of 1,000nM for leptin and 100nM for adiponectin. Triiodothyronine stimulated or inhibited the expression of adipokines in adipocytes at different times and doses which may be useful to assist in the treatment of obesity, assuming that leptin is increased and adiponectin is decreased, in obesity cases.

  3. Current classification, treatment options, and new perspectives in the management of adipocytic sarcomas

    Directory of Open Access Journals (Sweden)

    De Vita A

    2016-10-01

    Full Text Available Alessandro De Vita,1 Laura Mercatali,1 Federica Recine,1 Federica Pieri,2 Nada Riva,1 Alberto Bongiovanni,1 Chiara Liverani,1 Chiara Spadazzi,1 Giacomo Miserocchi,1 Dino Amadori,1 Toni Ibrahim1 1Osteoncology and Rare Tumors Center, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST IRCCS, Meldola, FC, 2Pathology Unit, Morgagni-Pierantoni Hospital, Forlì, Italy Abstract: Sarcomas are a heterogeneous group of mesenchymal tumors arising from soft tissue or bone, with an uncertain etiology and difficult classification. Soft tissue sarcomas (STSs account for around 1% of all adult cancers. Till date, more than 50 histologic subtypes have been identified. Adipocyte sarcoma or liposarcoma (LPS is one of the most common STS subtypes, accounting for 15% of all sarcomas, with an incidence of 24% of all extremity STSs and 45% of all retroperitoneal STSs. The new World Health Organization classification system has divided LPS into four different subgroups: atypical lipomatous tumor/well-differentiated LPS, dedifferentiated LPS, myxoid LPS, and pleomorphic LPS. These lesions can develop at any location and exhibit different aggressive potentials reflecting their morphologic diversity and clinical behavior. Patients affected by LPS should be managed in specialized multidisciplinary cancer centers. Whereas surgical resection is the mainstay of treatment for localized disease, the benefits of adjuvant and neoadjuvant chemotherapy are still unclear. Systemic treatment, particularly chemotherapy, is still limited in metastatic disease. Despite the efforts toward a better understanding of the biology of LPS, the outcome of advanced and metastatic patients remains poor. The advent of targeted therapies may lead to an improvement of treatment options and clinical outcomes. A larger patient enrollment into translational and clinical studies will help increase the knowledge of the biological behavior of LPSs, test new drugs, and introduce new

  4. Salt modulates the stability and lipid binding affinity of the adipocyte lipid-binding proteins

    Science.gov (United States)

    Schoeffler, Allyn J.; Ruiz, Carmen R.; Joubert, Allison M.; Yang, Xuemei; LiCata, Vince J.

    2003-01-01

    Adipocyte lipid-binding protein (ALBP or aP2) is an intracellular fatty acid-binding protein that is found in adipocytes and macrophages and binds a large variety of intracellular lipids with high affinity. Although intracellular lipids are frequently charged, biochemical studies of lipid-binding proteins and their interactions often focus most heavily on the hydrophobic aspects of these proteins and their interactions. In this study, we have characterized the effects of KCl on the stability and lipid binding properties of ALBP. We find that added salt dramatically stabilizes ALBP, increasing its Delta G of unfolding by 3-5 kcal/mol. At 37 degrees C salt can more than double the stability of the protein. At the same time, salt inhibits the binding of the fluorescent lipid 1-anilinonaphthalene-8-sulfonate (ANS) to the protein and induces direct displacement of the lipid from the protein. Thermodynamic linkage analysis of the salt inhibition of ANS binding shows a nearly 1:1 reciprocal linkage: i.e. one ion is released from ALBP when ANS binds, and vice versa. Kinetic experiments show that salt reduces the rate of association between ANS and ALBP while simultaneously increasing the dissociation rate of ANS from the protein. We depict and discuss the thermodynamic linkages among stability, lipid binding, and salt effects for ALBP, including the use of these linkages to calculate the affinity of ANS for the denatured state of ALBP and its dependence on salt concentration. We also discuss the potential molecular origins and potential intracellular consequences of the demonstrated salt linkages to stability and lipid binding in ALBP.

  5. [PRODUCT OF THE BMI1--A KEY COMPONENT OF POLYCOMB--POSITIVELY REGULATES ADIPOCYTE DIFFERENTIATION OF MOUSE MESENCHYMAL STEM CELLS].

    Science.gov (United States)

    Petrov, N S; Vereschagina, N A; Sushilova, E N; Kropotov, A V; Miheeva, N F; Popov, B V

    2016-01-01

    Bmil is a key component of Polycomb (PcG), which in mammals controls the basic functions of mammalian somatic stem cells (SSC) such as self-renewal and differentiation. Bmi1 supports SSC via transcriptional suppression of genes associated with cell cycle and differentiation. The most studied target genes of Bmi1 are the genes of Ink4 locus, CdkI p16(Ink4a) and p1(Arf), suppression of which due to activating mutations of the BMI1 results in formation of cancer stem cells (CSC) and carcinomas in various tissues. In contrast, inactivation of BMI1 results in cell cycle arrest and cell senescence. Although clinical phenomena of hypo- and hyperactivation of BMI1 are well known, its targets and mechanisms of regulation of tissue specific SSC are still obscure. The goal of this study was to evaluate the regulatory role of BMI1 in adipocyte differentiation (AD) of mouse mesenchymal stem cells (MSC). Induction of AD in mouse MSC of the C3H10T1/2 cell line was associated with an increase in the expression levels of BMI1, the genes of pRb family (RB, p130) and demethylase UTX, but not methyltransferase EZH2, whose products regulate the methylation levels of H3K27. It was observed earlier that H3K27me3 may play the role of the epigenetic switch by promoting AD of human MSC via activating expression of the PPARγ2, the master gene of AD (Hemming et al., 2014). Here we show that inactivation of BMI1 using specific siRNA slows and decreases the levels of AD, but does not abolish it. This is associated with a complete inhibition of the expression of adipogenic marker genes--PPARγ2, ADIPOQ and a decrease in the expression of RB, p130, but not UTX. The results obtained give evidence that the epigenetic mechanism regulating AD differentiation in mouse and human MSC is different.

  6. Long Non-Coding RNAs Associated with Metabolic Traits in Human White Adipose Tissue

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    Hui Gao

    2018-04-01

    Full Text Available Long non-coding RNAs (lncRNAs belong to a recently discovered class of molecules proposed to regulate various cellular processes. Here, we systematically analyzed their expression in human subcutaneous white adipose tissue (WAT and found that a limited set was differentially expressed in obesity and/or the insulin resistant state. Two lncRNAs herein termed adipocyte-specific metabolic related lncRNAs, ASMER-1 and ASMER-2 were enriched in adipocytes and regulated by both obesity and insulin resistance. Knockdown of either ASMER-1 or ASMER-2 by antisense oligonucleotides in in vitro differentiated human adipocytes revealed that both genes regulated adipogenesis, lipid mobilization and adiponectin secretion. The observed effects could be attributed to crosstalk between ASMERs and genes within the master regulatory pathways for adipocyte function including PPARG and INSR. Altogether, our data demonstrate that lncRNAs are modulators of the metabolic and secretory functions in human fat cells and provide an emerging link between WAT and common metabolic conditions. Keywords: White adipose tissue, Adipocytes, Long non-coding RNAs, Metabolic traits, Lipolysis, Adiponectin

  7. RPL13A and EEF1A1 Are Suitable Reference Genes for qPCR during Adipocyte Differentiation of Vascular Stromal Cells from Patients with Different BMI and HOMA-IR.

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    Gentile, Adriana-Mariel; Lhamyani, Said; Coín-Aragüez, Leticia; Oliva-Olivera, Wilfredo; Zayed, Hatem; Vega-Rioja, Antonio; Monteseirin, Javier; Romero-Zerbo, Silvana-Yanina; Tinahones, Francisco-José; Bermúdez-Silva, Francisco-Javier; El Bekay, Rajaa

    2016-01-01

    Real-time or quantitative PCR (qPCR) is a useful technique that requires reliable reference genes for data normalization in gene expression analysis. Adipogenesis is among the biological processes suitable for this technique. The selection of adequate reference genes is essential for qPCR gene expression analysis of human Vascular Stromal Cells (hVSCs) during their differentiation into adipocytes. To the best of our knowledge, there are no studies validating reference genes for the analyses of visceral and subcutaneous adipose tissue hVSCs from subjects with different Body Mass Index (BMI) and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index. The present study was undertaken to analyze this question. We first analyzed the stability of expression of five potential reference genes: CYC, GAPDH, RPL13A, EEF1A1, and 18S ribosomal RNA, during in vitro adipogenic differentiation, in samples from these types of patients. The expression of RPL13A and EEF1A1 was not affected by differentiation, thus being these genes the most stable candidates, while CYC, GAPDH, and 18S were not suitable for this sort of analysis. This work highlights that RPL13A and EEF1A1 are good candidates as reference genes for qPCR analysis of hVSCs differentiation into adipocytes from subjects with different BMI and HOMA-IR.

  8. Modest hypoxia significantly reduces triglyceride content and lipid droplet size in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Takeshi, E-mail: thashimo@fc.ritsumei.ac.jp [Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Yokokawa, Takumi; Endo, Yuriko [Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Iwanaka, Nobumasa [Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Higashida, Kazuhiko [Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Faculty of Sport Science, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192 (Japan); Taguchi, Sadayoshi [Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan)

    2013-10-11

    Highlights: •Long-term hypoxia decreased the size of LDs and lipid storage in 3T3-L1 adipocytes. •Long-term hypoxia increased basal lipolysis in 3T3-L1 adipocytes. •Hypoxia decreased lipid-associated proteins in 3T3-L1 adipocytes. •Hypoxia decreased basal glucose uptake and lipogenic proteins in 3T3-L1 adipocytes. •Hypoxia-mediated lipogenesis may be an attractive therapeutic target against obesity. -- Abstract: Background: A previous study has demonstrated that endurance training under hypoxia results in a greater reduction in body fat mass compared to exercise under normoxia. However, the cellular and molecular mechanisms that underlie this hypoxia-mediated reduction in fat mass remain uncertain. Here, we examine the effects of modest hypoxia on adipocyte function. Methods: Differentiated 3T3-L1 adipocytes were incubated at 5% O{sub 2} for 1 week (long-term hypoxia, HL) or one day (short-term hypoxia, HS) and compared with a normoxia control (NC). Results: HL, but not HS, resulted in a significant reduction in lipid droplet size and triglyceride content (by 50%) compared to NC (p < 0.01). As estimated by glycerol release, isoproterenol-induced lipolysis was significantly lowered by hypoxia, whereas the release of free fatty acids under the basal condition was prominently enhanced with HL compared to NC or HS (p < 0.01). Lipolysis-associated proteins, such as perilipin 1 and hormone-sensitive lipase, were unchanged, whereas adipose triglyceride lipase and its activator protein CGI-58 were decreased with HL in comparison to NC. Interestingly, such lipogenic proteins as fatty acid synthase, lipin-1, and peroxisome proliferator-activated receptor gamma were decreased. Furthermore, the uptake of glucose, the major precursor of 3-glycerol phosphate for triglyceride synthesis, was significantly reduced in HL compared to NC or HS (p < 0.01). Conclusion: We conclude that hypoxia has a direct impact on reducing the triglyceride content and lipid droplet size via

  9. Modest hypoxia significantly reduces triglyceride content and lipid droplet size in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Hashimoto, Takeshi; Yokokawa, Takumi; Endo, Yuriko; Iwanaka, Nobumasa; Higashida, Kazuhiko; Taguchi, Sadayoshi

    2013-01-01

    Highlights: •Long-term hypoxia decreased the size of LDs and lipid storage in 3T3-L1 adipocytes. •Long-term hypoxia increased basal lipolysis in 3T3-L1 adipocytes. •Hypoxia decreased lipid-associated proteins in 3T3-L1 adipocytes. •Hypoxia decreased basal glucose uptake and lipogenic proteins in 3T3-L1 adipocytes. •Hypoxia-mediated lipogenesis may be an attractive therapeutic target against obesity. -- Abstract: Background: A previous study has demonstrated that endurance training under hypoxia results in a greater reduction in body fat mass compared to exercise under normoxia. However, the cellular and molecular mechanisms that underlie this hypoxia-mediated reduction in fat mass remain uncertain. Here, we examine the effects of modest hypoxia on adipocyte function. Methods: Differentiated 3T3-L1 adipocytes were incubated at 5% O 2 for 1 week (long-term hypoxia, HL) or one day (short-term hypoxia, HS) and compared with a normoxia control (NC). Results: HL, but not HS, resulted in a significant reduction in lipid droplet size and triglyceride content (by 50%) compared to NC (p < 0.01). As estimated by glycerol release, isoproterenol-induced lipolysis was significantly lowered by hypoxia, whereas the release of free fatty acids under the basal condition was prominently enhanced with HL compared to NC or HS (p < 0.01). Lipolysis-associated proteins, such as perilipin 1 and hormone-sensitive lipase, were unchanged, whereas adipose triglyceride lipase and its activator protein CGI-58 were decreased with HL in comparison to NC. Interestingly, such lipogenic proteins as fatty acid synthase, lipin-1, and peroxisome proliferator-activated receptor gamma were decreased. Furthermore, the uptake of glucose, the major precursor of 3-glycerol phosphate for triglyceride synthesis, was significantly reduced in HL compared to NC or HS (p < 0.01). Conclusion: We conclude that hypoxia has a direct impact on reducing the triglyceride content and lipid droplet size via

  10. MicroRNA-24 promotes 3T3-L1 adipocyte differentiation by directly targeting the MAPK7 signaling

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Min, E-mail: min_jin@zju.edu.cn [Division of Reproductive Medicine & Infertility, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88#, Jiefang Rd., Hangzhou, Zhejiang, 310009 (China); Wu, Yutao; Wang, Jing [School of Medicine, Zhejiang University, 288# Yuhangtang Rd, Hangzhou, Zhejiang, 310003 (China); Chen, Jian; Huang, Yiting; Rao, Jinpeng; Feng, Chun [Division of Reproductive Medicine & Infertility, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88#, Jiefang Rd., Hangzhou, Zhejiang, 310009 (China)

    2016-05-20

    Over the past years, MicroRNAs (miRNAs) act as a vital role in harmony with gene regulation and maintaining cellular homeostasis. It is well testified that miRNAshave been involved in numerous physiological and pathological processes, including embryogenesis, cell fate decision, and cellular differentiation. Adipogenesis is an organized process of cellular differentiation by which pre-adipocytes differentiate towards mature adipocytes, and it is tightly modulated by a series of transcription factors such as peroxisome proliferator-activated receptor γ (PPAR-γ) and sterol regulatory-element binding proteins 1 (SREBP1). However, the molecular mechanisms underlying the connection between miRNAs and adipogenesis-related transcription factors remain obscure. In this study, we unveiled that miR- 24 was remarkably upregulated during 3T3-L1 adipogenesis. Overexpression of miR-24 significantly promoted 3T3-L1 adipogenesis, as evidenced by its ability to increase the expression of PPAR-γ and SREBP1, lipid droplet formation and triglyceride (TG) accumulation. Furthermore, we found that neither ectopic expression of miR-24nor miR-24 inhibitor affect cell proliferation and cell cycle progression. Finally, we demonstrated that miR-24 plays the modulational role by directly repressing MAPK7, a key number in the MAPK signaling pathway. These data indicate that miR-24 is a novel positive regulator of adipocyte differentiation by targeting MAPK7, which provides new insights into the molecular mechanism of miRNA-mediated cellular differentiation. -- Highlights: •We firstly found miR-24 was upregulated in 3T3-L1 pre-adipocytes differentiation. •miR-24 promoted 3T3-L1 pre-adipocytes differentiation while silencing the expression of miR-24 had an opposite function. •miR-24 regulated 3T3-L1 differentiation by directly targeting MAPK7 signaling pathway. •miR-24did not affect 3T3-L1 pre-adipocytes cellular proliferation.

  11. SDF7, a group of Scoparia dulcis Linn. derived flavonoid compounds, stimulates glucose uptake and regulates adipocytokines in 3T3-F442a adipocytes.

    Science.gov (United States)

    Beh, Joo Ee; Khoo, Li Teng; Latip, Jalifah; Abdullah, Mohd Paud; Alitheen, Noorjahan Baru Mohamed; Adam, Zainah; Ismail, Amin; Hamid, Muhajir

    2013-10-28

    Adipocytes are major tissues involved in glucose uptake second to skeletal muscle and act as the main adipocytokines mediator that regulates glucose uptake mechanism and cellular differentiation. The objective of this study were to examine the effect of the SDF7, which is a fraction consists of four flavonoid compounds (quercetin: p-coumaric acid: luteolin: apigenin=8: 26: 1: 3) from Scoparia dulcis Linn., on stimulating the downstream components of insulin signalling and the adipocytokines expression on different cellular fractions of 3T3-F442a adipocytes. Morphology and lipid accumulation of differentiated 3T3-F442a adipocytes by 100 nM insulin treated with different concentrations of SDF7 and rosiglitazone were examined followed by the evaluation of glucose uptake activity expressions of insulin signalling downstream components (IRS-1, PI3-kinase, PKB, PKC, TC10 and GLUT4) from four cellular fractions (plasma membrane, cytosol, high density microsome and low density microsome). Next, the expression level of adipocytokines (TNF-α, adiponectin and leptin) and immunoblotting of treated 3T3-F442 adipocytes was determined at 30 min and 480 min. Glucose transporter 4 (GLUT4) translocation of 3T3-F442a adipocytes membrane was also determined. Lastly, mRNA expression of adiponectin and PPAR-γ of 3T3-F442a adipocytes were induced and compared with basal concentration. It was found that SDF7 was able to induce adipocytes differentiation with great extends of morphological changes, lipid synthesis and lipid stimulation in vitro. SDF7 stimulation of glucose transport on 3T3-F442a adipocytes are found to be dose independent, time-dependent and plasma membrane GLUT4 expression-dependent. Moreover, SDF7 are observed to be able to suppress TNF-α and leptin expressions that were mediated by 3T3-F442a adipocytes, while stimulated adiponectin secretion on the cells. There was a significant expression (p<0.01) of protein kinase C and small G protein TC10 on 3T3-F442a adipocytes

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

    International Nuclear Information System (INIS)

    Kang, Seong-Il; Ko, Hee-Chul; Shin, Hye-Sun; Kim, Hyo-Min; Hong, Youn-Suk; Lee, Nam-Ho; Kim, Se-Jae

    2011-01-01

    Highlights: → Fucoxanthin enhances 3T3-L1 adipocyte differentiation at an early stage. → Fucoxanthin inhibits 3T3-L1 adipocyte differentiation at intermediate and late stages. → Fucoxanthin attenuates glucose uptake by inhibiting the phosphorylation of IRS in mature 3T3-L1 adipocytes. → 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 prolif