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Sample records for caveolin-deficient adipocytes alterations

  1. Culture of human adipose tissue explants leads to profound alteration of adipocyte gene expression.

    Science.gov (United States)

    Gesta, S; Lolmède, K; Daviaud, D; Berlan, M; Bouloumié, A; Lafontan, M; Valet, P; Saulnier-Blache, J S

    2003-03-01

    Primary culture of adipose tissue has often been used to investigate pharmacological and nutritional regulation of adipocyte gene expression. Possible alteration of adipocyte gene expression by primary culture on its own has not been explored in detail. In order to address this issue, explants were prepared from human subcutaneous adipose tissue recovered from plastic surgery and maintained for 0 to 48 h in DMEM supplemented with 10 % serum. At different time points, adipocytes were isolated from the explants by collagenase digestion, and mRNA expression and lipolysis were studied. Culture was associated with an accumulation of tumor necrosis factor-alpha (TNFalpha) in the culture medium, an increase in anaerobic glycolysis, and an increase in the basal lipolysis. In parallel, a rapid and dramatic decrease in the level of mRNA encoding for several adipocyte-specific proteins such as adipocyte lipid-binding protein, hormone-sensitive lipase, lipoprotein lipase, and peroxisome proliferation activating receptor-gamma2 was observed in isolated adipocytes. These downregulations were reminiscent of a dedifferentiation process. In parallel, primary culture was associated with an increase in adipocyte beta-actin, TNFalpha, glucose transporter-1 and hypoxia-induced factor-1alpha mRNAs. Treatment of explants with agents that increase cAMP (isobutylmethylxanthine and forskolin) prevented TNFalpha production and expression and culture-induced alterations of adipocyte gene expression. These data show that primary culture of human adipose tissue explants dramatically alters adipocyte gene expression.

  2. 10e12z CLA alters adipocyte differentiation and adipocyte cytokine expression and induces macrophage proliferation.

    Science.gov (United States)

    Belda, Benjamin J; Thompson, Jerry T; Eser, Pinar O; Vanden Heuvel, John P

    2012-05-01

    The trans-10, cis-12 (10e12z) conjugated linoleic acid (CLA) isomer of CLA is responsible for loss of lipid storage or adipose tissue in vitro or in vivo. This isomer also induces inflammatory signaling in both mouse and human adipocytes in vitro. However, when these events occur and whether they are significant enough to affect other cell types are unclear. In these experiments, the 3T3-L1 cell line has been used to examine the interaction between inflammatory signaling and decreased differentiation or lipid storage induced by 10e12z CLA. In assays measuring both lipid accumulation and gene expression, differentiating 3T3-L1 cells exhibit concurrent induction of inflammatory signaling, as measured by cyclooxygenase-2 expression, and a decrease in adipocyte marker gene expression. Furthermore, in fully differentiated adipocytes, as identified in microarray assays and confirmed with real-time polymerase chain reaction, 10e12z CLA also significantly affected expression of both matrix metalloprotein-3 (MMP-3), collagen VI α 3 ColVI alpha 3 (VIα3) and the cytokine epiregulin, demonstrating that the effects of 10e12z broadly impact adipocyte function. In agreement with other experimental systems, 10e12z CLA inhibited RAW 264.7 cell proliferation; however, in response to adipocyte-conditioned media, 10e12z-CLA-treated adipocytes induced proliferation of this cell line, suggesting that the effect of 10e12z CLA is context dependent. These results are largely consistent with the known activation of the inflammatory mediator nuclear factor-κB in adipocytes in vitro and in vivo by 10e12z CLA treatment and demonstrate that adipose is an important target tissue of this isomer that impacts other cell types.

  3. Mitochondrial (dys)function in adipocyte (de)-differentiation and systemic metabolic alterations

    NARCIS (Netherlands)

    Pauw, de A.; Tejerina, S.; Raes, M.; Keijer, J.; Arnould, T.

    2009-01-01

    In mammals, adipose tissue, composed of BAT and WAT, collaborates in energy partitioning and performs metabolic regulatory functions. It is the most flexible tissue in the body, because it is remodeled in size and shape by modifications in adipocyte cell size and/or number, depending on developmenta

  4. Short-term HFD does not alter lipolytic function of adipocytes

    Science.gov (United States)

    Wiedemann, Michael SF; Wueest, Stephan; Grob, Alexandra; Item, Flurin; Schoenle, Eugen J; Konrad, Daniel

    2014-01-01

    A short bout of high fat diet (HFD) impairs glucose tolerance and hepatic insulin sensitivity. We recently identified adipose tissue inflammation and resulting dysfunctional adipose tissue–liver cross-talk as an early event in the development of HFD-induced hepatic insulin resistance. In particular, reducing white adipose tissue (WAT) inflammation by adipocyte-specific depletion of Fas/CD95 protected mice from developing hepatic insulin resistance but not hepatic steatosis. Herein, we expanded our previous work and determined the impact of four days of HFD on lipolytic activity of isolated adipocytes. Compared with chow-fed mice, the degree of basal and isoproterenol-stimulated free fatty acid (FFA) and glycerol release was similar in HFD-fed animals. Moreover, insulin’s ability to suppress lipolysis remained intact, suggesting retained insulin sensitivity. Despite unaltered lipolysis, circulating FFA concentrations were greatly increased in non-fasted HFD-fed mice. In conclusion, a short-term HFD challenge does not affect lipolytic function of adipocytes. The observed increase of circulating FFA levels in randomly fed animals may rather be the result of increased dietary fat supply. PMID:24719784

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

    Science.gov (United States)

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

    2014-08-01

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

  6. Alterations in Lipids and Adipocyte Hormones in Female-to-Male Transsexuals

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    Prakash Chandra

    2010-01-01

    Full Text Available Testosterone therapy in men and women results in decreased high-density lipoprotein cholesterol (HDL and increased low-density lipoprotein cholesterol (LDL. We sought to determine whether testosterone therapy has this same effect on lipid parameters and adipocyte hormones in female-to-male (FTM transsexuals. Twelve FTM transsexuals provided a fasting lipid profile including serum total cholesterol, HDL, LDL, and triglycerides prior to and after 1 year of testosterone therapy (testosterone enanthate or cypionate 50–125 mg IM every two weeks. Subjects experienced a significant decrease in mean serum HDL (52±11 to 40±7 mg/dL (P<.001. The mean LDL (P=.316, triglyceride (P=.910, and total cholesterol (P=.769 levels remained unchanged. In a subset of subjects, we measured serum leptin levels which were reduced by 25% but did not reach statistical significance (P=.181 while resistin levels remained unchanged. We conclude that testosterone therapy in FTM transsexuals can promote an increased atherogenic lipid profile by lowering HDL and possibly reduce serum leptin levels. However, long-term studies are needed to determine whether decreases in HDL result in adverse cardiovascular outcomes.

  7. Superparamagnetic iron oxide nanoparticles alter expression of obesity and T2D-associated risk genes in human adipocytes

    NARCIS (Netherlands)

    Sharifi, S.; Daghighi, S.; Motazacker, M. M.; Badlou, B.; Sanjabi, B.; Akbarkhanzadeh, A.; Rowshani, A. T.; Laurent, S.; Peppelenbosch, M. P.; Rezaee, F.

    2013-01-01

    Adipocytes hypertrophy is the main cause of obesity and its affliction such as type 2 diabetes (T2D). Since superparamagnetic iron oxide nanoparticles (SPIONs) are used for a wide range of biomedical/medical applications, we aimed to study the effect of SPIONs on 22 and 29 risk genes (Based on gene

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

    Science.gov (United States)

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

    2014-09-09

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

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

    Directory of Open Access Journals (Sweden)

    I. Golic

    2014-09-01

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

  10. Superparamagnetic iron oxide nanoparticles alter expression of obesity and T2D-associated risk genes in human adipocytes

    Science.gov (United States)

    Sharifi, S.; Daghighi, S.; Motazacker, M. M.; Badlou, B.; Sanjabi, B.; Akbarkhanzadeh, A.; Rowshani, A. T.; Laurent, S.; Peppelenbosch, M. P.; Rezaee, F.

    2013-07-01

    Adipocytes hypertrophy is the main cause of obesity and its affliction such as type 2 diabetes (T2D). Since superparamagnetic iron oxide nanoparticles (SPIONs) are used for a wide range of biomedical/medical applications, we aimed to study the effect of SPIONs on 22 and 29 risk genes (Based on gene wide association studies) for obesity and T2D in human adipocytes. The mRNA expression of lipid and glucose metabolism genes was changed upon the treatment of human primary adipocytes with SPIONs. mRNA of GULP1, SLC30A8, NEGR1, SEC16B, MTCH2, MAF, MC4R, and TMEM195 were severely induced, whereas INSIG2, NAMPT, MTMR9, PFKP, KCTD15, LPL and GNPDA2 were down-regulated upon SPIONs stimulation. Since SEC16B gene assist the phagocytosis of apoptotic cells and this gene were highly expressed upon SPIONs treatment in adipocytes, it is logic to assume that SPIONs may play a crucial role in this direction, which requires more consideration in the future.

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

    OpenAIRE

    Vijayalakshmi Varma; Boros, László G; Nolen, Greg T.; Ching-Wei Chang; Martin Wabitsch; Beger, Richard D.; Jim Kaput

    2015-01-01

    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 asso...

  12. 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

  13. Exercise decreases lipogenic gene expression in adipose tissue and alters adipocyte cellularity during weight regain after weight loss.

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    Erin Danielle Giles

    2016-02-01

    Full Text Available Exercise is a potent strategy to facilitate long-term weight maintenance. In addition to increasing energy expenditure and reducing appetite, exercise also favors the oxidation of dietary fat, which likely helps prevent weight re-gain. It is unclear whether this exercise-induced metabolic shift is due to changes in energy balance, or whether exercise imparts additional adaptations in the periphery that limit the storage and favor the oxidation of dietary fat. To answer this question, adipose tissue lipid metabolism and related gene expression were studied in obese rats following weight loss and during the first day of relapse to obesity. Mature, obese rats were weight-reduced for 2 weeks with or without daily treadmill exercise (EX. Rats were weight maintained for 6 weeks, followed by relapse on: a ad libitum low fat diet (LFD, b ad libitum LFD plus EX, or c a provision of LFD to match the positive energy imbalance of exercised, relapsing animals. 24h retention of dietary- and de novo-derived fat were assessed directly using 14C palmitate/oleate and 3H20, respectively. Exercise decreased the size, but increased the number of adipocytes in both retroperitoneal (RP and subcutaneous (SC adipose depots, and prevented the relapse-induced increase in adipocyte size. Further, exercise decreased the expression of genes involved in lipid uptake (CD36 & LPL, de novo lipogenesis (FAS, ACC1, and triacylglycerol synthesis (MGAT & DGAT in RP adipose during relapse following weight loss. This was consistent with the metabolic data, whereby exercise reduced retention of de novo-derived fat even when controlling for the positive energy imbalance. The decreased trafficking of dietary fat to adipose tissue with exercise was explained by reduced energy intake which attenuated energy imbalance during refeeding. Despite having decreased expression of lipogenic genes, the net retention of de novo-derived lipid was higher in both the RP and SC adipose of exercising

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

    Science.gov (United States)

    Varma, Vijayalakshmi; Boros, László G; Nolen, Greg T; Chang, Ching-Wei; Wabitsch, Martin; Beger, Richard D; Kaput, Jim

    2015-06-16

    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.

  15. 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.

  16. Ethanol extracts of chickpeas alter the total lipid content and expression levels of genes related to fatty acid metabolism in mouse 3T3-L1 adipocytes

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    Shinohara, Shigeo; Gu, Yuanjun; Yang, Ying; Furuta, Yasuo; Tanaka, Masahiko; Yue, Xiaohua; Wang, Weiqing; Kitano, Masaru; Kimura, Hiroshi

    2016-01-01

    Desi-type chickpeas, which have long been used as a natural treatment for diabetes, have been reported to lower visceral adiposity, dyslipidemia and insulin resistance induced by a chronic high-fat diet in rats. In this study, in order to examine the effects of chickpeas of this type in an in vitro system, we used the 3T3-L1 mouse cell line, a subclone of Swiss 3T3 cells, which can differentiate into cells with an adipocyte-like phenotype, and we used ethanol extracts of chickpeas (ECP) instead of chickpeas. Treatment of the 3T3-L1 cells with ECP led to a decrease in the lipid content in the cells. The desaturation index, defined as monounsaturated fatty acids (MUFAs)/saturated fatty acids (SFAs), was also decreased by ECP due to an increase in the cellular content of SFAs and a decrease in the content of MUFAs. The decrease in this index may reflect a decreased reaction from SFA to MUFA, which is essential for fat storage. To confirm this hypothesis, we conducted a western blot analysis, which revealed a reduction in the amount of stearoyl-CoA desaturase 1 (SCD1), a key enzyme catalyzing the reaction from SFA to MUFA. We observed simultaneous inactivations of enzymes participating in lipogenesis, i.e., liver kinase B1 (LKB1), acetyl-CoA carboxylase (ACC) and AMPK, by phosphorylation, which may lead to the suppression of reactions from acetyl-CoA to SFA via malonyl-CoA in lipogenesis. We also investigated whether lipolysis is affected by ECP. The amount of carnitine palmitoyltransferase 1 (CPT1), an enzyme important for the oxidation of fatty acids, was increased by ECP treatment. ECP also led to an increase in uncoupling protein 2 (UCP2), reported as a key protein for the oxidation of fatty acids. All of these results obtained regarding lipogenesis and fatty acid metabolism in our in vitro system are consistent with the results previously shown in rats. We also examined the effects on SCD1 and lipid contents of ethanol extracts of Kabuli-type chickpeas, which are

  17. 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.

  18. Chronic TNFalpha and cAMP pre-treatment of human adipocytes alter HSL, ATGL and perilipin to regulate basal and stimulated lipolysis.

    Science.gov (United States)

    Bézaire, Véronic; Mairal, Aline; Anesia, Rodica; Lefort, Corinne; Langin, Dominique

    2009-09-17

    We examined the effects of chronic TNFalpha and dibutyryl-cAMP (Db-cAMP) pre-treatment on the lipolytic machinery of human hMADS adipocytes. TNFalpha decreased adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) protein content and triglycerides (TG)-hydrolase activity but increased basal lipolysis due to a marked reduction in perilipin (PLIN) protein content. Conversely, Db-cAMP increased ATGL and HSL protein content but prevented PLIN phosphorylation, the net result being accentuated basal lipolysis. In forskolin-stimulated conditions, TNFalpha and Db-cAMP pre-treatment decreased stimulated TG-hydrolase activity and impaired PLIN phosphorylation. Together, this resulted in a severely attenuated response to forskolin-stimulated lipolysis.

  19. 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

    for either RVD or RVI in pre-adipocytes. The insulin receptor (InsR) localizes to caveolae and its expression dramatically increases upon adipocyte differentiation. In pre-adipocytes, InsR and its effectors focal adhesion kinase (FAK) and extracellular signal regulated kinase (ERK1/2) localized to focal...... adhesions and were activated by a 5 min exposure to insulin (100 nM). Osmotic shrinkage transiently inhibited InsR Y(146)-phosphorylation, followed by an increase at t=15 min; a similar pattern was seen for ERK1/2 and FAK, in a manner unaffected by cholesterol depletion. In contrast, cell swelling had...... is not required for volume regulation. Given the relationship between hyperosmotic stress and insulin signaling, the finding that cell volume regulation is dramatically altered upon adipocyte differentiation may be relevant for the understanding of insulin resistance and metabolic syndrome....

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

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    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

  1. Adipocyte differentiation and leptin expression

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  2. SIRT1 Limits Adipocyte Hyperplasia through c-Myc Inhibition.

    Science.gov (United States)

    Abdesselem, Houari; Madani, Aisha; Hani, Ahmad; Al-Noubi, Muna; Goswami, Neha; Ben Hamidane, Hisham; Billing, Anja M; Pasquier, Jennifer; Bonkowski, Michael S; Halabi, Najeeb; Dalloul, Rajaa; Sheriff, Mohamed Z; Mesaeli, Nasrin; ElRayess, Mohamed; Sinclair, David A; Graumann, Johannes; Mazloum, Nayef A

    2016-01-29

    The expansion of fat mass in the obese state is due to increased adipocyte hypertrophy and hyperplasia. The molecular mechanism that drives adipocyte hyperplasia remains unknown. The NAD(+)-dependent protein deacetylase sirtuin 1 (SIRT1), a key regulator of mammalian metabolism, maintains proper metabolic functions in many tissues, counteracting obesity. Here we report that differentiated adipocytes are hyperplastic when SIRT1 is knocked down stably in mouse 3T3-L1 preadipocytes. This phenotype is associated with dysregulated adipocyte metabolism and enhanced inflammation. We also demonstrate that SIRT1 is a key regulator of proliferation in preadipocytes. Quantitative proteomics reveal that the c-Myc pathway is altered to drive enhanced proliferation in SIRT1-silenced 3T3-L1 cells. Moreover, c-Myc is hyperacetylated, levels of p27 are reduced, and cyclin-dependent kinase 2 (CDK2) is activated upon SIRT1 reduction. Remarkably, differentiating SIRT1-silenced preadipocytes exhibit enhanced mitotic clonal expansion accompanied by reduced levels of p27 as well as elevated levels of CCAAT/enhancer-binding protein β (C/EBPβ) and c-Myc, which is also hyperacetylated. c-Myc activation and enhanced proliferation phenotype are also found to be SIRT1-dependent in proliferating mouse embryonic fibroblasts and differentiating human SW872 preadipocytes. Reducing both SIRT1 and c-Myc expression in 3T3-L1 cells simultaneously does not induce the adipocyte hyperplasia phenotype, confirming that SIRT1 controls adipocyte hyperplasia through c-Myc regulation. A better understanding of the molecular mechanisms of adipocyte hyperplasia will open new avenues toward understanding obesity.

  3. Transcriptional networks controlling adipocyte differentiation

    DEFF Research Database (Denmark)

    Siersbæk, R; Mandrup, Susanne

    2011-01-01

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

  4. Omentum and bone marrow: how adipocyte-rich organs create tumour microenvironments conducive for metastatic progression

    Science.gov (United States)

    Gusky, H. Chkourko; Diedrich, J.; MacDougald, O. A.; Podgorski, I.

    2016-01-01

    Summary A number of clinical studies have linked adiposity with increased cancer incidence, progression and metastasis, and adipose tissue is now being credited with both systemic and local effects on tumour development and survival. Adipocytes, a major component of benign adipose tissue, represent a significant source of lipids, cytokines and adipokines, and their presence in the tumour microenvironment substantially affects cellular trafficking, signalling and metabolism. Cancers that have a high predisposition to metastasize to the adipocyte-rich host organs are likely to be particularly affected by the presence of adipocytes. Although our understanding of how adipocytes influence tumour progression has grown significantly over the last several years, the mechanisms by which adipocytes regulate the meta-static niche are not well-understood. In this review, we focus on the omentum, a visceral white adipose tissue depot, and the bone, a depot for marrow adipose tissue, as two distinct adipocyte-rich organs that share common characteristic: they are both sites of significant metastatic growth. We highlight major differences in origin and function of each of these adipose depots and reveal potential common characteristics that make them environments that are attractive and conducive to secondary tumour growth. Special attention is given to how omental and marrow adipocytes modulate the tumour microenvironment by promoting angiogenesis, affecting immune cells and altering metabolism to support growth and survival of metastatic cancer cells. PMID:27432523

  5. On the origin of human adipocytes and the contribution of bone marrow-derived cells.

    Science.gov (United States)

    Rydén, Mikael

    2016-01-01

    In the last decade, results in both animal models and humans have demonstrated that white adipocytes are generated over the entire life-span. This adds to the plasticity of adipose tissue and alterations in adipocyte turnover are linked to metabolic dysfunction. Adipocytes are derived from precursors present primarily in the perivascular areas of adipose tissue but their precise origin remains unclear. The multipotent differentiation capacity of bone marrow-derived cells (BMDC) has prompted the suggestion that BMDC may contribute to different cell tissue pools, including adipocytes. However, data in murine transplantation models have been conflicting and it has been a matter of debate whether BMDC actually differentiate into adipocytes or just fuse with resident fat cells. To resolve this controversy in humans, we recently performed a study in 65 subjects that had undergone bone marrow transplantation. Using a set of newly developed assays including single cell genome-wide analyses of mature adipocytes, we demonstrated that bone marrow contributes with approximately 10 % to the adipocyte pool. This proportion was more than doubled in obesity, suggesting that BMDC may constitute a reserve pool for adipogenesis, particularly upon weight gain. This commentary discusses the possible relevance of these and other recent findings for human pathophysiology.

  6. Disruption of Lipid Raft Function Increases Expression and Secretion of Monocyte Chemoattractant Protein-1 in 3T3-L1 Adipocytes.

    Science.gov (United States)

    Lu, Juu-Chin; Chiang, Yu-Ting; Lin, Yu-Chun; Chang, Yu-Tzu; Lu, Chia-Yun; Chen, Tzu-Yu; Yeh, Chia-Shan

    2016-01-01

    The adipocyte is unique in its capacity to store lipids. In addition to triglycerides, the adipocyte stores a significant amount of cholesterol. Moreover, obese adipocytes are characterized by a redistribution of cholesterol with depleted cholesterol in the plasma membrane, suggesting that cholesterol perturbation may play a role in adipocyte dysfunction. We used methyl-β-cyclodextrin (MβCD), a molecule with high affinity for cholesterol, to rapidly deplete cholesterol level in differentiated 3T3-L1 adipocytes. We tested whether this perturbation altered adipocyte secretion of monocyte chemoattractant protein-1 (MCP-1), a chemokine that is elevated in obesity and is linked to obesity-associated chronic diseases. Depletion of cholesterol by MβCD increased MCP-1 secretion as well as the mRNA and protein levels, suggesting perturbation at biosynthesis and secretion. Pharmacological inhibition revealed that NF-κB, but not MEK, p38 and JNK, was involved in MβCD-stimulated MCP-1 biosynthesis and secretion in adipocytes. Finally, another cholesterol-binding drug, filipin, also induced MCP-1 secretion without altering membrane cholesterol level. Interestingly, both MβCD and filipin disturbed the integrity of lipid rafts, the membrane microdomains enriched in cholesterol. Thus, the depletion of membrane cholesterol in obese adipocytes may result in dysfunction of lipid rafts, leading to the elevation of proinflammatory signaling and MCP-1 secretion in adipocytes.

  7. Effect of dietary restriction on carcass composition and adipocyte cellularity of swine with different propensities for obesity.

    Science.gov (United States)

    Etherton, T D; Wangsness, P J; Hammers, V M; Ziegler, J H

    1982-12-01

    Experiments were conducted to determine whether dietary restriction altered body composition and adipocyte cellularity similarly in growing lean (Yorkshire) and obese (Ossabaw) swine. Yorkshire (YR) and Ossabaw (OR) swine were fed 65% of the weekly intake of ad libitum-fed Yorkshire (YA) and Ossabaw (OA) swine for 20 weeks. At 200 days of age, adipose tissue mass was 7-fold lower and muscle mass was 50% lower in YR than YA. However, adipose tissue mass of OR was only 2.6-fold less than OA. Furthermore, muscle mass did not differ between OR and OA. Adipocyte number per carcass was 6-fold higher in YA than YR. No differences in carcass adipocyte number were observed between OA and OR. Dietary restriction resulted in a reduced adipocyte size in both breeds of swine. However, adipocyte size for both dietary treatments was greater for obese than lean swine. When carcass adipocyte number was expressed per Kilogram of muscle, there were no differences among YA, OA, and OR; however, this ratio was lower in YR. These results demonstrate: 1) that alterations in nutrient partitioning as measured by accretion of these tissues are different in lean and obese swine when intake is restricted, 2) that differences in adipose tissue mass of YA and OA are due to differences in cell size, and 3) that muscle growth and adipocyte hyperplasia in swine may have a physiological relationship.

  8. Metformin limits the adipocyte tumor-promoting effect on ovarian cancer.

    Science.gov (United States)

    Tebbe, Calvin; Chhina, Jasdeep; Dar, Sajad A; Sarigiannis, Kalli; Giri, Shailendra; Munkarah, Adnan R; Rattan, Ramandeep

    2014-07-15

    Omental adipocytes promote ovarian cancer by secretion of adipokines, cytokines and growth factors, and acting as fuel depots. We investigated if metformin modulates the ovarian cancer promoting effects of adipocytes. Effect of conditioned media obtained from differentiated mouse 3T3L1 preadipoctes on the proliferation and migration of a mouse ovarian surface epithelium cancer cell line (ID8) was estimated. Conditioned media from differentiated adipocytes increased the proliferation and migration of ID8 cells, which was attenuated by metformin. Metformin inhibited adipogenesis by inhibition of key adipogenesis regulating transcription factors (CEBPα, CEBPß, and SREBP1), and induced AMPK. A targeted Cancer Pathway Finder RT-PCR (real-time polymerase chain reaction) based gene array revealed 20 up-regulated and 2 down-regulated genes in ID8 cells exposed to adipocyte conditioned media, which were altered by metformin. Adipocyte conditioned media also induced bio-energetic changes in the ID8 cells by pushing them into a highly metabolically active state; these effects were reversed by metformin. Collectively, metformin treatment inhibited the adipocyte mediated ovarian cancer cell proliferation, migration, expression of cancer associated genes and bio-energetic changes. Suggesting, that metformin could be a therapeutic option for ovarian cancer at an early stage, as it not only targets ovarian cancer, but also modulates the environmental milieu.

  9. Branched-chain amino acid catabolism fuels adipocyte differentiation and lipogenesis.

    Science.gov (United States)

    Green, Courtney R; Wallace, Martina; Divakaruni, Ajit S; Phillips, Susan A; Murphy, Anne N; Ciaraldi, Theodore P; Metallo, Christian M

    2016-01-01

    Adipose tissue plays important roles in regulating carbohydrate and lipid homeostasis, but less is known about the regulation of amino acid metabolism in adipocytes. Here we applied isotope tracing to pre-adipocytes and differentiated adipocytes to quantify the contributions of different substrates to tricarboxylic acid (TCA) metabolism and lipogenesis. In contrast to proliferating cells, which use glucose and glutamine for acetyl-coenzyme A (AcCoA) generation, differentiated adipocytes showed increased branched-chain amino acid (BCAA) catabolic flux such that leucine and isoleucine from medium and/or from protein catabolism accounted for as much as 30% of lipogenic AcCoA pools. Medium cobalamin deficiency caused methylmalonic acid accumulation and odd-chain fatty acid synthesis. Vitamin B12 supplementation reduced these metabolites and altered the balance of substrates entering mitochondria. Finally, inhibition of BCAA catabolism compromised adipogenesis. These results quantitatively highlight the contribution of BCAAs to adipocyte metabolism and suggest that BCAA catabolism has a functional role in adipocyte differentiation.

  10. PPARgamma in adipocyte differentiation and metabolism

    DEFF Research Database (Denmark)

    Siersbaek, Rasmus; Nielsen, Ronni; Mandrup, Susanne

    2010-01-01

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

  11. Mitochondria in White, Brown, and Beige Adipocytes

    Directory of Open Access Journals (Sweden)

    Miroslava Cedikova

    2016-01-01

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

  12. Modulating the Genomic Programming of Adipocytes

    DEFF Research Database (Denmark)

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

    2015-01-01

    transcriptional plasticity when exposed to physiological and metabolic stimuli. In our work, we have focused on understanding the processes responsible for modulating the genomic programming in response to different external signals. Thus, we have shown that browning of human adipocytes with rosiglitazone......, such as Krüppel-like factor 11 (KLF11) that are essential for modulating the genomic program in white adipocytes to induce browning. Furthermore, we have shown that acute suppression of adipocyte genes by the proinflammatory cytokine, tumor necrosis factor (TNF), involves redistribution of cofactors to enhancers...

  13. Adipocyte biology in polycystic ovary syndrome.

    Science.gov (United States)

    Barber, T M; Franks, S

    2013-07-05

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

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

    Science.gov (United States)

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

    2012-05-01

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

  15. Gene expression profiling in multipotent DFAT cells derived from mature adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Hiromasa [Laboratory of Cell and Tissue Biology, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510 (Japan); Database Center for Life Science (DBCLS), Research Organization of Information and Systems (ROIS), Faculty of Engineering Bldg.12 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Oki, Yoshinao [Laboratory of Cell and Tissue Biology, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510 (Japan); Bono, Hidemasa [Database Center for Life Science (DBCLS), Research Organization of Information and Systems (ROIS), Faculty of Engineering Bldg.12 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Kano, Koichiro, E-mail: kkano@brs.nihon-u.ac.jp [Laboratory of Cell and Tissue Biology, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510 (Japan)

    2011-04-15

    Highlights: {yields} Adipocyte dedifferentiation is evident in a significant decrease in typical genes. {yields} Cell proliferation is strongly related to adipocyte dedifferentiation. {yields} Dedifferentiated adipocytes express several lineage-specific genes. {yields} Comparative analyses using publicly available datasets boost the interpretation. -- Abstract: Cellular dedifferentiation signifies the withdrawal of cells from a specific differentiated state to a stem cell-like undifferentiated state. However, the mechanism of dedifferentiation remains obscure. Here we performed comparative transcriptome analyses during dedifferentiation in mature adipocytes (MAs) to identify the transcriptional signatures of multipotent dedifferentiated fat (DFAT) cells derived from MAs. Using microarray systems, we explored similarly expressed as well as significantly differentially expressed genes in MAs during dedifferentiation. This analysis revealed significant changes in gene expression during this process, including a significant reduction in expression of genes for lipid metabolism concomitantly with a significant increase in expression of genes for cell movement, cell migration, tissue developmental processes, cell growth, cell proliferation, cell morphogenesis, altered cell shape, and cell differentiation. Our observations indicate that the transcriptional signatures of DFAT cells derived from MAs are summarized in terms of a significant decrease in functional phenotype-related genes and a parallel increase in cell proliferation, altered cell morphology, and regulation of the differentiation of related genes. A better understanding of the mechanisms involved in dedifferentiation may enable scientists to control and possibly alter the plasticity of the differentiated state, which may lead to benefits not only in stem cell research but also in regenerative medicine.

  16. 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.

  17. 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

  18. Withaferin A induces apoptosis and inhibits adipogenesis in 3T3-L1 adipocytes.

    Science.gov (United States)

    Park, Hea Jin; Rayalam, Srujana; Della-Fera, Mary Anne; Ambati, Suresh; Yang, Jeong-Yeh; Baile, Clifton A

    2008-01-01

    Withaferin A (WA), a highly oxygenated steroidal lactone that is found in the medicinal plant Withania somnifera (also called ashwagandha) has been reported to have anti-tumor, anti-angiogenesis, and pro-apoptotic activity. We investigated the effects of WA on viability, apoptosis and adipogenesis in 3T3-L1 adipocytes. Pre- and post-confluent preadipocytes and mature adipocytes were treated with WA (1-25 microM) up to 24 hrs. Viability and apoptosis were measured by CellTiter-Blue Cell Viability Assay and single strand DNA ELISA Assay, respectively. WA decreased viability and induced apoptosis in all stages of cells. Induction of apoptosis by WA in mature adipocytes was mediated by increased ERK1/2 phosphorylation and altered Bax and Bcl2 protein expression. The effect of WA on adipogenesis was examined by AdipoRed Assay after treating with WA (0.1-1 microM) during the differentiation period. WA decreased lipid accumulation in a dose-dependent manner and decreased the expression of peroxisome proliferator-activated receptor gamma, CCAAT/enhancer binding protein alpha and adipocyte fatty acid binding protein. The effects on apoptosis and lipid accumulation were also confirmed with Hoechst staining and Oil Red O staining, respectively. These results show that WA acts on adipocytes to reduce cell viability and adipogenesis and also induce apoptosis.

  19. Gallic Acid, the Active Ingredient of Terminalia bellirica, Enhances Adipocyte Differentiation and Adiponectin Secretion.

    Science.gov (United States)

    Makihara, Hiroko; Koike, Yuka; Ohta, Masatomi; Horiguchi-Babamoto, Emi; Tsubata, Masahito; Kinoshita, Kaoru; Akase, Tomoko; Goshima, Yoshio; Aburada, Masaki; Shimada, Tsutomu

    2016-01-01

    Visceral obesity induces the onset of metabolic disorders such as insulin resistance and diabetes mellitus. Adipose tissue is considered as a potential pharmacological target for treating metabolic disorders. The fruit of Terminalia bellirica is extensively used in Ayurvedic medicine to treat patients with diseases such as diabetes mellitus. We previously investigated the effects of a hot water extract of T. bellirica fruit (TB) on obesity and insulin resistance in spontaneously obese type 2 diabetic mice. To determine the active ingredients of TB and their molecular mechanisms, we focused on adipocyte differentiation using mouse 3T3-L1 cells, which are widely used to study adipocyte physiology. We show here that TB enhanced the differentiation of 3T3-L1 cells to mature adipocytes and that one of the active main components was identified as gallic acid. Gallic acid (10-30 µM) enhanced the expression and secretion of adiponectin via adipocyte differentiation and also that of fatty acid binding protein-4, which is the target of peroxisome proliferator-activated receptor gamma (PPARγ), although it does not alter the expression of the upstream genes PPARγ and CCAAT enhancer binding protein alpha. In the PPARγ ligand assay, the binding of gallic acid to PPARγ was undetectable. These findings indicate that gallic acid mediates the therapeutic effects of TB on metabolic disorders by regulating adipocyte differentiation. Therefore, TB shows promise as a candidate for preventing and treating patients with metabolic syndrome.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

  5. SMRT-GPS2 corepressor pathway dysregulation coincides with obesity-linked adipocyte inflammation

    Science.gov (United States)

    Toubal, Amine; Clément, Karine; Fan, Rongrong; Ancel, Patricia; Pelloux, Veronique; Rouault, Christine; Veyrie, Nicolas; Hartemann, Agnes; Treuter, Eckardt; Venteclef, Nicolas

    2012-01-01

    Low-grade chronic inflammation is a major characteristic of obesity and results from deregulated white adipose tissue function. Consequently, there is interest in identifying the underlying regulatory mechanisms and components that drive adipocyte inflammation. Here, we report that expression of the transcriptional corepressor complex subunits GPS2 and SMRT was significantly reduced in obese adipose tissue, inversely correlated to inflammatory status, and was restored upon gastric bypass surgery–induced weight loss in morbid obesity. These alterations correlated with reduced occupancy of the corepressor complex at inflammatory promoters, providing a mechanistic explanation for elevated inflammatory transcription. In support of these correlations, RNAi-mediated depletion of GPS2 and SMRT from cultured human adipocytes promoted derepression of inflammatory transcription and elevation of obesity-associated inflammatory markers, such as IL-6 and MCP-1. Furthermore, we identified a regulatory cascade containing PPARγ and TWIST1 that controlled the expression of GPS2 and SMRT in human adipocytes. These findings were clinically relevant, because treatment of diabetic obese patients with pioglitazone, an antidiabetic and antiinflammatory PPARγ agonist, restored expression of TWIST1, GPS2, and SMRT in adipose tissue. Collectively, our findings identify alterations in a regulatory transcriptional network in adipocytes involving the dysregulation of a specific corepressor complex as among the initiating events promoting adipose tissue inflammation in human obesity. PMID:23221346

  6. 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.

  7. 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

    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.

  8. Altered adipocyte properties in the offspring of protein malnourished rats

    OpenAIRE

    Shepherd, P. R.; Crowther, N J; Desai, M; Hales, C. N.; Ozanne, S. E.

    1997-01-01

    It is becoming well established that poor fetal and early postnatal growth can have long-term effects on adult health, including susceptibility to non-insulin-dependent diabetes mellitus, cardiovascular disease and hypertension. It is suggested that this results from poor nutrition during early life having permanent effects on the structure and metabolism of certain organs and tissues. In the present study we investigated the effect of a low-protein diet during pregnancy and lactation on adip...

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

    Institute of Scientific and Technical Information of China (English)

    Günter Müller

    2011-01-01

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

  10. Berberine attenuates autophagy in adipocytes by targeting BECN1

    OpenAIRE

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-10

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

  12. Modulation of chromatin access during adipocyte differentiation

    DEFF Research Database (Denmark)

    Mandrup, Susanne; Hager, Gordon L

    2012-01-01

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

  13. Effects of parabens on adipocyte differentiation.

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2014-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Smas Cynthia M

    2008-09-01

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

  16. CD1d-mediated Presentation of Endogenous Lipid Antigens by Adipocytes Requires Microsomal Triglyceride Transfer Protein*

    Science.gov (United States)

    Rakhshandehroo, Maryam; Gijzel, Sanne M. W.; Siersbæk, Rasmus; Broekema, Marjoleine F.; de Haar, Colin; Schipper, Henk S.; Boes, Marianne; Mandrup, Susanne; Kalkhoven, Eric

    2014-01-01

    Obesity-induced adipose tissue (AT) dysfunction results in a chronic low-grade inflammation that predisposes to the development of insulin resistance and type 2 diabetes. During the development of obesity, the AT-resident immune cell profile alters to create a pro-inflammatory state. Very recently, CD1d-restricted invariant (i) natural killer T (NKT) cells, a unique subset of lymphocytes that are reactive to so called lipid antigens, were implicated in AT homeostasis. Interestingly, recent data also suggest that human and mouse adipocytes can present such lipid antigens to iNKT cells in a CD1d-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 up-regulated in early adipogenesis, and are transcriptionally controlled by CCAAT/enhancer-binding protein (C/EBP)-β and -δ. Moreover, adipocyte-induced Th1 and Th2 cytokine release by iNKT cells also occurred in the absence of exogenous ligands, suggesting the display of endogenous lipid antigen-D1d complexes by 3T3-L1 adipocytes. Furthermore, we identified microsomal triglyceride transfer protein, which we show is also under the transcriptional regulation of C/EBPβ and –δ, as a novel player in the presentation of endogenous lipid antigens by adipocytes. Overall, our findings indicate that adipocytes can function as non-professional lipid antigen presenting cells, which may present an important aspect of adipocyte-immune cell communication in the regulation of whole body energy metabolism and immune homeostasis. PMID:24966328

  17. CD1d-mediated presentation of endogenous lipid antigens by adipocytes requires microsomal triglyceride transfer protein.

    Science.gov (United States)

    Rakhshandehroo, Maryam; Gijzel, Sanne M W; Siersbæk, Rasmus; Broekema, Marjoleine F; de Haar, Colin; Schipper, Henk S; Boes, Marianne; Mandrup, Susanne; Kalkhoven, Eric

    2014-08-08

    Obesity-induced adipose tissue (AT) dysfunction results in a chronic low-grade inflammation that predisposes to the development of insulin resistance and type 2 diabetes. During the development of obesity, the AT-resident immune cell profile alters to create a pro-inflammatory state. Very recently, CD1d-restricted invariant (i) natural killer T (NKT) cells, a unique subset of lymphocytes that are reactive to so called lipid antigens, were implicated in AT homeostasis. Interestingly, recent data also suggest that human and mouse adipocytes can present such lipid antigens to iNKT cells in a CD1d-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 up-regulated in early adipogenesis, and are transcriptionally controlled by CCAAT/enhancer-binding protein (C/EBP)-β and -δ. Moreover, adipocyte-induced Th1 and Th2 cytokine release by iNKT cells also occurred in the absence of exogenous ligands, suggesting the display of endogenous lipid antigen-D1d complexes by 3T3-L1 adipocytes. Furthermore, we identified microsomal triglyceride transfer protein, which we show is also under the transcriptional regulation of C/EBPβ and -δ, as a novel player in the presentation of endogenous lipid antigens by adipocytes. Overall, our findings indicate that adipocytes can function as non-professional lipid antigen presenting cells, which may present an important aspect of adipocyte-immune cell communication in the regulation of whole body energy metabolism and immune homeostasis.

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

    Directory of Open Access Journals (Sweden)

    Kristoffer Ström

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

  19. 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

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

    Science.gov (United States)

    Scheja, Ludger; Heeren, Joerg

    2016-05-01

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

  1. Optical detection of pores in adipocyte membrane

    Science.gov (United States)

    Yanina, I. Yu.; Doubrovski, V. A.; Tuchin, V. V.

    2013-08-01

    Structures that can be interpreted as cytoplasm droplets leaking through the membrane are experimentally detected on the membranes of adipocytes using optical digital microscopy. The effect of an aqueous alcohol solution of brilliant green on the amount and sizes of structures is studied. It is demonstrated that the optical irradiation of the adipocytes that are sensitized with the aid of the brilliant green leads to an increase in the amount of structures (pores) after the irradiation. The experimental results confirm the existence of an earlier-proposed effect of photochemical action on the sensitized cells of adipose tissue that involves additional formation of pores in the membrane of the sensitized cell under selective optical irradiation. The proposed method for the detection of micropores in the membrane of adipose tissue based on the detection of the cytoplasm droplets leaking from the cell can be considered as a method for the optical detection of nanosized pores.

  2. Notch pathway is dispensable for adipocyte specification.

    Science.gov (United States)

    Nichols, Amy M; Pan, Yonghua; Herreman, An; Hadland, Brandon K; De Strooper, Bart; Kopan, Raphael; Huppert, Stacey S

    2004-09-01

    In the past decade we have witnessed an epidemic of obesity in developed countries. Therefore, understanding the mechanisms involved in regulation of body weight is becoming an increasingly important goal shared by the public and the scientific community. The key to fat deposition is the adipocyte, a specialized cell that plays a critical role in energy balance and appetite regulation. Much of our knowledge of adipogenesis comes from studies using preadipocytic cell lines that have provided important information regarding molecular control of adipocyte differentiation. However, they fall short of revealing how naive cells acquire competence for adipogenesis. Studies in preadipocytes indicate that the Notch pathway plays a role in regulating adipogenesis (Garces et al.: J Biol Chem 272:29729-29734, 1997). Given the known biological functions of Notch in mediating cell fate decisions (Artavanis-Tsakonas et al.: Science 284:770-776, 1999), we wished to test the hypothesis that the Notch pathway is required for this cellular program by examining adipogenesis in several genetic loss-of-function models that encompass the entire pathway. We conclude that the "canonical" Notch signaling pathway is dispensable for adipocyte specification and differentiation from either mesenchymal or epithelial progenitors.

  3. Bacterial translocation - impact on the adipocyte compartment.

    Science.gov (United States)

    Kruis, Tassilo; Batra, Arvind; Siegmund, Britta

    2014-01-01

    Over the last decade it became broadly recognized that adipokines and thus the fat tissue compartment exert a regulatory function on the immune system. Our own group described the pro-inflammatory function of the adipokine leptin within intestinal inflammation in a variety of animal models. Following-up on this initial work, the aim was to reveal stimuli and mechanisms involved in the activation of the fat tissue compartment and the subsequent release of adipokines and other mediators paralleled by the infiltration of immune cells. This review will summarize the current literature on the possible role of the mesenteric fat tissue in intestinal inflammation with a focus on Crohn's disease (CD). CD is of particular interest in this context since the transmural intestinal inflammation has been associated with a characteristic hypertrophy of the mesenteric fat, a phenomenon called "creeping fat." The review will address three consecutive questions: (i) What is inducing adipocyte activation, (ii) which factors are released after activation and what are the consequences for the local fat tissue compartment and infiltrating cells; (iii) do the answers generated before allow for an explanation of the role of the mesenteric fat tissue within intestinal inflammation? With this review we will provide a working model indicating a close interaction in between bacterial translocation, activation of the adipocytes, and subsequent direction of the infiltrating immune cells. In summary, the models system mesenteric fat indicates a unique way how adipocytes can directly interact with the immune system.

  4. Dedifferentiated adipocyte-derived progeny cells (DFAT cells)

    OpenAIRE

    Wei, Shengjuan; Zan, Linsen; Hausman, Gary J.; Rasmussen, Theodore P; Bergen, Werner G.; Dodson, Michael V.

    2013-01-01

    Analyses of mature adipocytes have shown that they possess a reprogramming ability in vitro, which is associated with dedifferentiation. The subsequent dedifferentiated fat cells (DFAT cells) are multipotent and can differentiate into adipocytes and other cell types as well. Mature adipocytes can be easily obtained by biopsy, and the cloned progeny cells are homogeneous in vitro. Therefore, DFAT cells (a new type of stem cell) may provide an excellent source of cells for tissue regeneration, ...

  5. 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.

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

    Science.gov (United States)

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

    2014-10-01

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

  7. Notch intracellular domain overexpression in adipocytes confers lipodystrophy in mice

    Directory of Open Access Journals (Sweden)

    Dionysios V. Chartoumpekis

    2015-07-01

    Conclusions: Increased Notch signaling in adipocytes in mice results in blocked expansion of white adipose tissue which leads to ectopic accumulation of lipids and insulin resistance, thus to a lipodystrophic phenotype. These results suggest that further investigation of the role of Notch signaling in adipocytes could lead to the manipulation of this pathway for therapeutic interventions in metabolic disease.

  8. DNA microarray analysis of genes differentially expressed in adipocyte differentiation

    Indian Academy of Sciences (India)

    Chunyan Yin; Yanfeng Xiao; Wei Zhang; Erdi Xu; Weihua Liu; Xiaoqing Yi; Ming Chang

    2014-06-01

    In the present study, the human liposarcoma cell line SW872 was used to identify global changes in gene expression profiles occurring during adipogenesis. We further explored some of the genes expressed during the late phase of adipocyte differentiation. These genes may play a major role in promoting excessive proliferation and accumulation of lipid droplets, which contribute to the development of obesity. By using microarray-based technology, we examined differential gene expression in early differentiated adipocytes and late differentiated adipocytes. Validated genes exhibited a ≥ 10-fold increase in the late phase of adipocyte differentiation by polymerase chain reaction (RT-PCR). Compared with undifferentiated preadipocytes, we found that 763 genes were increased in early differentiated adipocytes, and 667 genes were increased in later differentiated adipocytes. Furthermore, 21 genes were found being expressed 10-fold higher in the late phase of adipocyte differentiation. The results were in accordance with the RT-PCR test, which validated 11 genes, namely, CIDEC, PID1, LYRM1, ADD1, PPAR2, ANGPTL4, ADIPOQ, ACOX1, FIP1L1, MAP3K2 and PEX14. Most of these genes were found being expressed in the later phase of adipocyte differentiation involved in obesity-related diseases. The findings may help to better understand the mechanism of obesity and related diseases.

  9. Phytochemicals and regulation of the adipocyte life cycle.

    Science.gov (United States)

    Rayalam, Srujana; Della-Fera, Mary Anne; Baile, Clifton A

    2008-11-01

    Natural products have potential for inducing apoptosis, inhibiting adipogenesis and stimulating lipolysis in adipocytes. The objective of this review is to discuss the adipocyte life cycle and various dietary bioactives that target different stages of adipocyte life cycle. Different stages of adipocyte development include preadipocytes, maturing preadipocytes and mature adipocytes. Various dietary bioactives like genistein, conjugated linoleic acid (CLA), docosahexaenoic acid, epigallocatechin gallate, quercetin, resveratrol and ajoene affect adipocytes during specific stages of development, resulting in either inhibition of adipogenesis or induction of apoptosis. Although numerous molecular targets that can be used for both treatment and prevention of obesity have been identified, targeted monotherapy has resulted in lack of success. Thus, targeting several signal transduction pathways simultaneously with multiple natural products to achieve additive or synergistic effects might be an appropriate approach to address obesity. We have previously reported two such combinations, namely, ajoene+CLA and vitamin D+genistein. CLA enhanced ajoene-induced apoptosis in mature 3T3-L1 adipocytes by synergistically increasing the expression of several proapoptotic factors. Similarly, genistein potentiated vitamin D's inhibition of adipogenesis and induction of apoptosis in maturing preadipocytes by an enhanced expression of VDR (vitamin D receptor) protein. These two examples indicate that combination therapy employing compounds that target different stages of the adipocyte life cycle might prove beneficial for decreasing adipose tissue volume by inducing apoptosis or by inhibiting adipogenesis or both.

  10. Obesity Beige adipocytes-will they beat obesity?

    DEFF Research Database (Denmark)

    Sandholt, Camilla H.; Pedersen, Oluf.

    2015-01-01

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

  11. Dysregulation of lipolysis and lipid metabolism in visceral and subcutaneous adipocytes by high-fat diet: role of ATGL, HSL, and AMPK.

    Science.gov (United States)

    Gaidhu, Mandeep P; Anthony, Nicole M; Patel, Prital; Hawke, Thomas J; Ceddia, Rolando B

    2010-04-01

    This study investigated the molecular mechanisms by which a high-fat diet (HFD) dysregulates lipolysis and lipid metabolism in mouse epididymal (visceral, VC) and inguinal (subcutaneous, SC) adipocytes. Eight-weeks of HFD feeding increased adipose triglyceride lipase (ATGL) content and comparative gene identification-58 (CGI-58) expression, whereas hormone-sensitive lipase (HSL) phosphorylation and perilipin content were severely reduced. Adipocytes from HFD mice elicited increased basal but blunted epinephrine-stimulated lipolysis and increased diacylglycerol content in both fat depots. Consistent with impaired adrenergic receptor signaling, HFD also increased adipose-specific phospholipase A(2) expression in both fat depots. Inhibition of E-prostanoid 3 receptor increased basal lipolysis in control adipocytes but failed to acutely alter the effects of HFD on lipolysis in both fat depots. In HFD visceral adipocytes, activation of adenylyl cyclases by forskolin increased HSL phosphorylation and surpassed the lipolytic response of control cells. However, in HFD subcutaneous adipocytes, forskolin induced lipolysis without detectable HSL phosphorylation, suggesting activation of an alternative lipase in response to HFD-induced suppression of HSL in VC and SC adipocytes. HFD also powerfully inhibited basal, epinephrine-, and forskolin-induced AMP kinase (AMPK) activation as well peroxisome proliferator-activated receptor gamma coactivator-1alpha expression, citrate synthase activity, and palmitate oxidation in both fat depots. In summary, novel evidence is provided that defective adrenergic receptor signaling combined with upregulation of ATGL and suppression of HSL and AMPK signaling mediate HFD-induced alterations in lipolysis and lipid utilization in VC and SC adipocytes, which may play an important role in defective lipid mobilization and metabolism seen in diet-induced obesity.

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

    Science.gov (United States)

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

    2013-02-26

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

  13. Berberine attenuates autophagy in adipocytes by targeting BECN1.

    Science.gov (United States)

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

    2014-10-01

    The lysosomal degradation pathway, autophagy, is essential for the maintenance of cellular homeostasis. Recently, autophagy has been demonstrated to be required in the process of adipocyte conversion. However, its role in mature adipocytes under physiological and pathological conditions remains unclear. Here, we report a major function of BECN1 in the regulation of basal autophagy in mature adipocytes. We also show that berberine, a natural plant alkaloid, inhibits basal autophagy in adipocytes and adipose tissue of mice fed a high-fat diet via downregulation of BECN1 expression. We further demonstrate that berberine has a pronounced effect on the stability of Becn 1 mRNA through the Mir30 family. These findings explore the potential of BECN1 as a key molecule and a drug target for regulating autophagy in mature adipocytes.

  14. Impaired response of mature adipocytes of diabetic mice to hypoxia

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seok Jong, E-mail: seok-hong@northwestern.edu; Jin, Da P.; Buck, Donald W.; Galiano, Robert D.; Mustoe, Thomas A., E-mail: tmustoe@nmh.org

    2011-10-01

    Adipose tissue contains various cells such as infiltrated monocytes/macrophages, endothelial cells, preadipocytes, and adipocytes. Adipocytes have an endocrine function by secreting adipokines such as interleukin (IL)-6, tumor necrosis factor (TNF)-{alpha}, leptin, and adiponectin. Dysregulation of adipokines in adipose tissues leads to a chronic low-grade inflammation which could result in atherosclerosis, hypertension, and type 2 diabetes. A sustained inflammatory state, which is characterized by prolonged persistence of macrophages and neutrophils, is found in diabetic wounds. In addition, subcutaneous adipocytes are enormously increased in amount clinically in type 2 diabetes. However, the function of subcutaneous adipocytes, which play an important role in injured tissue subjected to hypoxia, has not been well characterized in vitro due to the difficulty of maintaining mature adipocytes in culture using conventional methods because of their buoyancy. In this study, we established a novel in vitro culture method of mature adipocytes by enclosing them in a hyaluronan (HA) based hydrogel to study their role in response to stress such as hypoxia. BrdU labeling and Ki67 immunostaining experiments showed that hydrogel enclosed mature adipocytes proliferate in vitro. Both mRNA and protein expression analyses for hypoxia regulated genes, such as vascular endothelial growth factor (VEGF) and heme oxygenase 1 (HO1), showed that mature adipocytes of wild type mice respond to hypoxia. In contrast, mature adipocytes of diabetic db/db and TallyHo mice did not efficiently respond to hypoxia. Our studies suggest that mature adipocytes are functionally active cells, and their abnormal function to hypoxia can be one of underlining mechanisms in type 2 diabetes.

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

    Directory of Open Access Journals (Sweden)

    Bao G Vu

    Full Text Available BACKGROUND: Human adipocytes may have significant functions in wound healing and the development of diabetes through production of pro-inflammatory cytokines after stimulation by gram-negative bacterial endotoxin. Diabetic foot ulcers are most often associated with staphylococcal infections. Adipocyte responses in the area of the wound may play a role in persistence and pathology. We studied the effect of staphylococcal superantigens (SAgs on immortalized human adipocytes, alone and in the presence of bacterial endotoxin or staphylococcal α-toxin. METHODOLOGY/PRINCIPAL FINDINGS: Primary non-diabetic and diabetic human preadipocytes were immortalized by the reverse transcriptase component of telomerase (TERT and the E6/E7 genes of human papillomavirus. The immortal cells were demonstrated to have properties of non-immortalized pre-adipocytes and could be differentiated into mature and functional adipocytes. Differentiated adipocytes exposed to staphylococcal SAgs produced robust levels of cytokines IL-6 and IL-8, but there were no significant differences in levels between the non-diabetic and diabetic cells. Cytokine production was increased by co-incubation of adipocytes with SAgs and endotoxin together. In contrast, α-toxin alone was cytotoxic at high concentrations, but, at sub-cytotoxic doses, did not stimulate production of IL-6 and IL-8. CONCLUSIONS/SIGNIFICANCE: Endotoxin has been proposed to contribute to diabetes through enhanced insulin resistance after chronic exposure and stimulation of adipocytes to produce cytokines. Our data indicate staphylococcal SAgs TSST-1 and SEB alone and in combination with bacterial endotoxin also stimulate adipocytes to produce cytokines and thus may contribute to the inflammatory response found in chronic diabetic ulcers and in the systemic inflammation that is associated with the development and persistence of diabetes. The immortal human pre-adipocytes reported here will be useful for studies to

  16. Suppressive actions of eicosapentaenoic acid on lipid droplet formation in 3T3-L1 adipocytes

    Directory of Open Access Journals (Sweden)

    Sinclair Andrew J

    2010-06-01

    Full Text Available Abstract Background Lipid droplet (LD formation and size regulation reflects both lipid influx and efflux, and is central in the regulation of adipocyte metabolism, including adipokine secretion. The length and degree of dietary fatty acid (FA unsaturation is implicated in LD formation and regulation in adipocytes. The aims of this study were to establish the impact of eicosapentaenoic acid (EPA; C20:5n-3 in comparison to SFA (STA; stearic acid, C18:0 and MUFA (OLA; oleic acid, C18:1n-9 on 3T3-L1 adipocyte LD formation, regulation of genes central to LD function and adipokine responsiveness. Cells were supplemented with 100 μM FA during 7-day differentiation. Results EPA markedly reduced LD size and total lipid accumulation, suppressing PPARγ, Cidea and D9D/SCD1 genes, distinct from other treatments. These changes were independent of alterations of lipolytic genes, as both EPA and STA similarly elevated LPL and HSL gene expressions. In response to acute lipopolysaccharide exposure, EPA-differentiated adipocytes had distinct improvement in inflammatory response shown by reduction in monocyte chemoattractant protein-1 and interleukin-6 and elevation in adiponectin and leptin gene expressions. Conclusions This study demonstrates that EPA differentially modulates adipogenesis and lipid accumulation to suppress LD formation and size. This may be due to suppressed gene expression of key proteins closely associated with LD function. Further analysis is required to determine if EPA exerts a similar influence on LD formation and regulation in-vivo.

  17. Bisphenol A effects on gene expression in adipocytes from children: association with metabolic disorders.

    Science.gov (United States)

    Menale, Ciro; Piccolo, Maria Teresa; Cirillo, Grazia; Calogero, Raffaele A; Papparella, Alfonso; Mita, Luigi; Del Giudice, Emanuele Miraglia; Diano, Nadia; Crispi, Stefania; Mita, Damiano Gustavo

    2015-06-01

    Bisphenol A (BPA) is a xenobiotic endocrine-disrupting chemical. In vitro and in vivo studies have indicated that BPA alters endocrine-metabolic pathways in adipose tissue, which increases the risk of metabolic disorders and obesity. BPA can affect adipose tissue and increase fat cell numbers or sizes by regulating the expression of the genes that are directly involved in metabolic homeostasis and obesity. Several studies performed in animal models have accounted for an obesogen role of BPA, but its effects on human adipocytes - especially in children - have been poorly investigated. The aim of this study is to understand the molecular mechanisms by which environmentally relevant doses of BPA can interfere with the canonical endocrine function that regulates metabolism in mature human adipocytes from prepubertal, non-obese children. BPA can act as an estrogen agonist or antagonist depending on the physiological context. To identify the molecular signatures associated with metabolism, transcriptional modifications of mature adipocytes from prepubertal children exposed to estrogen were evaluated by means of microarray analysis. The analysis of deregulated genes associated with metabolic disorders allowed us to identify a small group of genes that are expressed in an opposite manner from that of adipocytes treated with BPA. In particular, we found that BPA increases the expression of pro-inflammatory cytokines and the expression of FABP4 and CD36, two genes involved in lipid metabolism. In addition, BPA decreases the expression of PCSK1, a gene involved in insulin production. These results indicate that exposure to BPA may be an important risk factor for developing metabolic disorders that are involved in childhood metabolism dysregulation.

  18. Genistein inhibits differentiation of primary human adipocytes.

    Science.gov (United States)

    Park, Hea Jin; Della-Fera, Mary Anne; Hausman, Dorothy B; Rayalam, Srujana; Ambati, Suresh; Baile, Clifton A

    2009-02-01

    Genistein, a major soy isoflavone, has been reported to exhibit antiadipogenic and proapoptotic potential in vivo and in vitro. It is also a phytoestrogen which has high affinity to estrogen receptor beta. In this study, we determined the effect of genistein on adipogenesis and estrogen receptor (ER) alpha and beta expression during differentiation in primary human preadipocytes. Genistein inhibited lipid accumulation in a dose-dependent manner at concentrations of 6.25 microM and higher, with 50 microM genistein inhibiting lipid accumulation almost completely. Low concentrations of genistein (3.25 microM) increased cell viability and higher concentrations (25 and 50 microM) decreased it by 16.48+/-1.35% (P<.0001) and 50.68+/-1.34% (P<.0001). Oil Red O staining was used to confirm the effects on lipid accumulation. The inhibition of lipid accumulation was associated with inhibition of glycerol-3-phosphate dehydrogenase activity and down-regulation of expression of adipocyte-specific genes, including peroxisome proliferator-activated receptor gamma, CCAAT/enhancer binding protein alpha, glycerol-3-phosphate dehydrogenase, adipocyte fatty acid binding protein, fatty acid synthase, sterol regulatory element-binding protein 1, perilipin, leptin, lipoprotein lipase and hormone-sensitive lipase. These effects of genistein during the differentiation period were associated with down-regulation of ERalpha and ERbeta expression. This study adds to the elucidation of the molecular pathways involved in the inhibition of adipogenesis by phytoestrogens.

  19. Regulation of vascular tone by adipocytes

    Directory of Open Access Journals (Sweden)

    Van de Voorde Johan

    2011-03-01

    Full Text Available Abstract Recent studies have shown that adipose tissue is an active endocrine and paracrine organ secreting several mediators called adipokines. Adipokines include hormones, inflammatory cytokines and other proteins. In obesity, adipose tissue becomes dysfunctional, resulting in an overproduction of proinflammatory adipokines and a lower production of anti-inflammatory adipokines. The pathological accumulation of dysfunctional adipose tissue that characterizes obesity is a major risk factor for many other diseases, including type 2 diabetes, cardiovascular disease and hypertension. Multiple physiological roles have been assigned to adipokines, including the regulation of vascular tone. For example, the unidentified adipocyte-derived relaxing factor (ADRF released from adipose tissue has been shown to relax arteries. Besides ADRF, other adipokines such as adiponectin, omentin and visfatin are vasorelaxants. On the other hand, angiotensin II and resistin are vasoconstrictors released by adipocytes. Reactive oxygen species, leptin, tumour necrosis factor α, interleukin-6 and apelin share both vasorelaxing and constricting properties. Dysregulated synthesis of the vasoactive and proinflammatory adipokines may underlie the compromised vascular reactivity in obesity and obesity-related disorders.

  20. CDK4 is an essential insulin effector in adipocytes

    Science.gov (United States)

    Lagarrigue, Sylviane; Lopez-Mejia, Isabel C.; Denechaud, Pierre-Damien; Escoté, Xavier; Castillo-Armengol, Judit; Jimenez, Veronica; Chavey, Carine; Giralt, Albert; Lai, Qiuwen; Zhang, Lianjun; Martinez-Carreres, Laia; Delacuisine, Brigitte; Annicotte, Jean-Sébastien; Blanchet, Emilie; Huré, Sébastien; Abella, Anna; Tinahones, Francisco J.; Vendrell, Joan; Dubus, Pierre; Bosch, Fatima; Kahn, C. Ronald; Fajas, Lluis

    2015-01-01

    Insulin resistance is a fundamental pathogenic factor that characterizes various metabolic disorders, including obesity and type 2 diabetes. Adipose tissue contributes to the development of obesity-related insulin resistance through increased release of fatty acids, altered adipokine secretion, and/or macrophage infiltration and cytokine release. Here, we aimed to analyze the participation of the cyclin-dependent kinase 4 (CDK4) in adipose tissue biology. We determined that white adipose tissue (WAT) from CDK4-deficient mice exhibits impaired lipogenesis and increased lipolysis. Conversely, lipolysis was decreased and lipogenesis was increased in mice expressing a mutant hyperactive form of CDK4 (CDK4R24C). A global kinome analysis of CDK4-deficient mice following insulin stimulation revealed that insulin signaling is impaired in these animals. We determined that insulin activates the CCND3-CDK4 complex, which in turn phosphorylates insulin receptor substrate 2 (IRS2) at serine 388, thereby creating a positive feedback loop that maintains adipocyte insulin signaling. Furthermore, we found that CCND3 expression and IRS2 serine 388 phosphorylation are increased in human obese subjects. Together, our results demonstrate that CDK4 is a major regulator of insulin signaling in WAT. PMID:26657864

  1. Gender Differences in Adipocyte Metabolism and Liver Cancer Progression.

    Science.gov (United States)

    Cheung, Otto K-W; Cheng, Alfred S-L

    2016-01-01

    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.

  2. 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.

  3. Fructose consumption and moderate zinc deficiency influence growth and adipocyte metabolism in young rats prone to adult-onset obesity.

    Science.gov (United States)

    Streiff, Erin L; Stanhope, Kimber L; Graham, James; Havel, Peter J; King, Janet C

    2007-07-01

    The effects of low zinc, high fructose diet on growth and adipocyte metabolism were examined in rats. At 28 days of age, animals were assigned to diets either adequate in zinc (30 ppm) with water (AZW) or fructose solution (AZF), or low in zinc (5 ppm) with water (LZW) or fructose solution (LZF). Body weight and food and fructose solution intake were measured three times a week. Blood samples were collected at baseline, 4 weeks, and 8 weeks, and energy expenditure was measured. The rats were killed at 12 weeks. Adipocytes were cultured in medium containing C14-glucose and physiological insulin concentrations. The animals in the LZF group consumed less energy and gained less weight than the other groups. Serum zinc concentrations were lower in the LZF than the AZF group. Energy expenditure over a 24-h period did not differ between groups; however, the respiratory quotient in the fed state was higher in the groups consuming fructose solution than in those consuming water. The mesenteric adipocytes from the animals in the LZF group utilized more glucose. Thus, the addition of fructose to a LZ diet reduced energy intake and growth and altered adipocyte fuel metabolism in young growing rats.

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

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  2. File list: Oth.Adp.20.AllAg.Pre-adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  3. File list: Oth.Adp.50.AllAg.Pre-adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  4. File list: NoD.Adp.20.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  5. File list: His.Adp.05.AllAg.Pre-adipocytes [Chip-atlas[Archive

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  6. File list: His.Adp.10.AllAg.Pre-adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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  8. File list: InP.Adp.05.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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  10. File list: Oth.Adp.10.AllAg.Pre-adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  11. File list: His.Adp.50.AllAg.Pre-adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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  15. File list: Pol.Adp.50.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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  19. File list: His.Adp.20.AllAg.Pre-adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

    Full Text Available InP.Adp.10.AllAg.Brown_adipocytes mm9 Input control Adipocyte Brown adipocytes SRX1...43805,SRX185879,SRX478163 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Adp.10.AllAg.Brown_adipocytes.bed ...

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

    Lifescience Database Archive (English)

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

    Lifescience Database Archive (English)

    Full Text Available InP.Adp.50.AllAg.Brown_adipocytes mm9 Input control Adipocyte Brown adipocytes SRX1...85879,SRX143805,SRX478163 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Adp.50.AllAg.Brown_adipocytes.bed ...

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

    Science.gov (United States)

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

    2016-07-01

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

  7. 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.

  8. Metabolic programming of a beige adipocyte phenotype by genistein

    Science.gov (United States)

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

    2016-01-01

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

  9. 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.

  10. Higher levels of ATGL are associated with exercise-induced enhancement of lipolysis in rat epididymal adipocytes.

    Directory of Open Access Journals (Sweden)

    Junetsu Ogasawara

    Full Text Available BACKGROUND: In adipose cells, adipose triglyceride lipase (ATGL catalyzes the first step in adipocyte triacylglyceride hydrolysis, thereby regulating both basal and hormone-stimulated lipolysis. However, little is known about the molecular mechanism(s underlying habitual exercise-induced adaptive modulation of ATGL in white adipocytes via alteration in transcription regulator and lipolytic cofactors. METHODOLOGY/PRINCIPAL RESULTS: Male Wistar rats were randomly divided into 2 groups a sedentary control group (CG and a habitual exercise group (EG. The EG was subjected to running on a treadmill set at 5 days per week for 9 weeks. The CG was not subjected to running on a treadmill. In the EG, levels of ATGL mRNA and protein were elevated with a significant increase in lipolysis compared with the CG, accompanied by a significant increase in associations of CGI-58 with ATGL protein. Under these conditions, an upregulation of peroxisome proliferation-activated receptorg-2 (PPARg-2 was observed. In the EG, the addition of rosiglitazone further significantly increased the levels of ATGL protein compared with the CG. However, attenuated levels of the ATGL protein in adipocytes were obtained by the addition of insulin, which is known to inhibit the expression of ATGL, in both types of groups. Actually, levels of plasma insulin were significantly reduced in the EG compared with the CG. CONCLUSIONS: These data suggest that elevated levels of ATGL are involved in the exercise-induced enhancement of lipolysis in primary adipocytes. The exact mechanism(s underlying this phenomenon is associated, at least in part, with upregulated transcriptional activation of PPARg-2. In addition, exercise-induced lower circulation levels of insulin also correlate with habitual exercise-induced higher levels of ATGL in primary adipocytes.

  11. Dedifferentiated adipocyte-derived progeny cells (DFAT cells)

    Science.gov (United States)

    Wei, Shengjuan; Zan, Linsen; Hausman, Gary J; Rasmussen, Theodore P; Bergen, Werner G; Dodson, Michael V

    2013-01-01

    Analyses of mature adipocytes have shown that they possess a reprogramming ability in vitro, which is associated with dedifferentiation. The subsequent dedifferentiated fat cells (DFAT cells) are multipotent and can differentiate into adipocytes and other cell types as well. Mature adipocytes can be easily obtained by biopsy, and the cloned progeny cells are homogeneous in vitro. Therefore, DFAT cells (a new type of stem cell) may provide an excellent source of cells for tissue regeneration, engineering and disease treatment. The dedifferentiation of mature adipocytes, the multipotent capacity of DFAT cells and comparisons and contrasts with mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPS) are discussed in this review. PMID:23991357

  12. Dietary relevant mixtures of phytoestrogens inhibit adipocyte differentiation in vitro

    DEFF Research Database (Denmark)

    Taxvig, Camilla; Specht, Ina Olmer; Boberg, Julie

    2013-01-01

    Phytoestrogens (PEs) are naturally occurring plant components, with the ability to induce biological responses in vertebrates by mimicking or modulating the action of endogenous hormones.Single isoflavones have been shown to affect adipocyte differentiation, but knowledge on the effect of dietary...... as tested for their PPARγ activating abilities. The results showed that mixtures of isoflavonoid parent compounds and metabolites, respectively, a mixture of lignan metabolites, as well as coumestrol concentration-dependently inhibited adipocyte differentiation. Furthermore, a mixture of isoflavonoid parent...

  13. Metabolic Fate of Branched-Chain Amino Acids During Adipogenesis, in Adipocytes From Obese Mice and C2C12 Myotubes.

    Science.gov (United States)

    Estrada-Alcalde, Isabela; Tenorio-Guzman, Miriam R; Tovar, Armando R; Salinas-Rubio, Daniela; Torre-Villalvazo, Ivan; Torres, Nimbe; Noriega, Lilia G

    2017-04-01

    Branched-chain amino acid (BCAA) catabolism is regulated by the branched-chain aminotransferase (BCAT2) and the branched-chain α-keto acid dehydrogenase complex (BCKDH). BCAT2 and BCKDH expression and activity are modified during adipogenesis and altered in adipose tissues of mice with genetic or diet-induced obesity. However, little is known about how these modifications and alterations affect the intracellular metabolic fate of BCAAs during adipogenesis, in adipocytes from mice fed a control or high-fat diet or in C2C12 myotubes. Here, we demonstrate that BCAAs are mainly incorporated into proteins during the early stages of adipocyte differentiation. However, they are oxidized and incorporated into lipids during the late days of differentiation. Conversely, 92% and 97% of BCAA were oxidized, 1.6% and 6% were used for protein synthesis and 1.2% and 1.5% were incorporated into lipids in adipocytes from epididymal and subcutaneous adipose tissue, respectively. All three pathways were decreased in adipocytes from mice fed a high-fat diet. In C2C12 myotubes, leucine is mainly used for protein synthesis and palmitate is incorporated into lipids. Interestingly, leucine decreased both palmitate oxidation and its incorporation to lipids and proteins; and palmitate increased leucine oxidation and decreased its incorporation to lipids and proteins in a dose-dependent manner. These results demonstrate that BCAA metabolic fate differs between the early and late stages of adipocyte differentiation and in adipocytes from mice fed a control or high-fat diet; and that leucine affects the metabolic fate of palmitate and vice versa in C2C12 myotubes. J. Cell. Biochem. 118: 808-818, 2017. © 2016 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    Parray, Hilal Ahmad; Yun, Jong Won

    2016-05-01

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

  15. Curcumin improves hypoxia induced dysfunctions in 3T3-L1 adipocytes by protecting mitochondria and down regulating inflammation.

    Science.gov (United States)

    Priyanka, Ariyapalli; Anusree, Sasidharan Suseela; Nisha, Vijayakumar Marykutty; Raghu, Kozhiparambil Gopalan

    2014-01-01

    Obesity induced metabolic syndrome is increasing worldwide at an alarming rate. It is characterized by excessive expansion of white adipose tissue which leads to hypoxia and impairs normal metabolism. Recent studies reveal that hypoxia could be one of the factors for inflammation, insulin resistance and other obesity related complications. There is a high demand for anti-obese phytoceuticals to control and manage the complications resulting from obesity. In this study, we investigated how hypoxia affect the physiological functions of 3T3-L1 adipocytes emphasizing on oxidative stress, inflammation, and mitochondrial functions. We also evaluated the protective role of various doses of curcumin, a well-known dietary antioxidant, on hypoxia induced alterations. The results revealed that hypoxia significantly altered the vital parameters of adipocyte biology like HIF 1α expression (103.47% ↑), lactate, and glycerol release (184.34% and 69.1% ↑, respectively), reactive oxygen species production (432.53% ↑), lipid and protein oxidation (376.6% and 566.6% ↑, respectively), reduction in antioxidant enzymes (superoxide dismutase and catalase) status, secretion of inflammatory markers (TNF α, IL 6, IL 1β, and IFN γ), and mitochondrial functions (mitochondrial mass, membrane potential, permeability transition pore integrity, and superoxide generation). Curcumin substantially protected adipocytes from toxic effects of hypoxia in a dose dependent manner by protecting mitochondria and down regulating inflammation. Acriflavine is used as a positive control. A detailed investigation is required for the development of curcumin as an effective nutraceutical against obesity.

  16. Resistance to diet-induced adiposity in cannabinoid receptor-1 deficient mice is not due to impaired adipocyte function

    Directory of Open Access Journals (Sweden)

    Oosterveer Maaike H

    2011-12-01

    Full Text Available Abstract 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 diet-induced obesity. Whether this phenotype of CB1-/- mice is related to altered fat metabolism in adipose tissue is unknown. Methods We evaluated adipose tissue differentiation/proliferation markers and quantified lipogenic and lipolytic activities in fat tissues of CB1-/- and CB1+/+ mice fed a high-fat (HF or a high-fat/fish oil (HF/FO diet as compared to animals receiving a low-fat chow diet. Comparison between HF diet and HF/FO diet allowed to investigate the influence of dietary fat quality on adipose tissue biology in relation to CB1 functioning. Results The adiposity-resistant phenotype of the CB1-/- mice was characterized by reduced fat mass and adipocyte size in HF and HF/FO-fed CB1-/- mice in parallel to a significant increase in energy expenditure as compared to CB1+/+ mice. The expression levels of adipocyte differentiation and proliferation markers were however maintained in these animals. Consistent with unaltered lipogenic gene expression, the fatty acid synthesis rates in adipose tissues from CB1-/- and CB1+/+ mice were unchanged. Whole-body and adipose-specific lipoprotein lipase (LPL activities were also not altered in CB1-/- mice. Conclusions These findings indicate that protection against diet-induced adiposity in CB1-deficient mice is not related to changes in adipocyte function per se, but rather results from increased energy dissipation by oxidative and non-oxidative pathways.

  17. Insulin: pancreatic secretion and adipocyte regulation.

    Science.gov (United States)

    Baumgard, L H; Hausman, G J; Sanz Fernandez, M V

    2016-01-01

    Insulin is the primary acute anabolic coordinator of nutrient partitioning. Hyperglycemia is the main stimulant of insulin secretion, but other nutrients such as specific amino acids, fatty acids, and ketoacids can potentiate pancreatic insulin release. Incretins are intestinal hormones with insulinotropic activity and are secreted in response to food ingestion, thus integrating diet chemical composition with the regulation of insulin release. In addition, prolactin is required for proper islet development, and it stimulates β-cell proliferation. Counterintuitively, bacterial components appear to signal insulin secretion. In vivo lipopolysaccharide infusion acutely increases circulating insulin, which is paradoxical as endotoxemia is a potent catabolic condition. Insulin is a potent anabolic orchestrator of nutrient partitioning, and this is particularly true in adipocytes. Insulin dictates lipid accretion in a dose-dependent manner during preadipocyte development in adipose tissue-derived stromal vascular cell culture. However, in vivo studies focused on insulin's role in regulating adipose tissue metabolism from growing, and market weight pigs are sometimes inconsistent, and this variability appears to be animal, age and depot dependent. Additionally, porcine adipose tissue synthesizes and secretes a number of adipokines (leptin, adiponectin, and so forth) that directly or indirectly influence insulin action. Therefore, because insulin has an enormous impact on agriculturally important phenotypes, it is critical to have a better understanding of how insulin homeostasis is governed.

  18. Dietary t10,c12-CLA but not c9,t11 CLA reduces adipocyte size in the absence of changes in the adipose renin-angiotensin system in fa/fa Zucker rats.

    Science.gov (United States)

    DeClercq, Vanessa; Zahradka, Peter; Taylor, Carla G

    2010-11-01

    In obesity, increased activity of the local renin-angiotensin system (RAS) and enlarged adipocytes with altered adipokine production are linked to the development of obesity-related health problems and cardiovascular disease. Mixtures of conjugated linoleic acid (CLA) isomers have been shown to reduce adipocyte size and alter the production of adipokines. The objective of this study was to investigate the effects of feeding individual CLA isomers on adipocyte size and adipokines associated with the local adipose RAS. Male fa/fa Zucker rats received either (a) control, (b) cis(c)9,trans(t)11-CLA, or (c) t10,c12-CLA diet for 8 weeks. The t10,c12-CLA isomer reduced adipocyte size and increased cell number in epididymal adipose tissue. RT-PCR and Western blot analysis revealed that neither CLA isomer altered mRNA or protein levels of angiotensinogen or AngII receptors in adipose tissue. Likewise, levels of the pro-inflammatory cytokines TNF-α and IL-6 or the anti-inflammatory cytokine IL-10 were unchanged in adipose tissue. Similarly, neither CLA isomer had any effect on phosphorylation nor DNA binding of NF-κB. Our results suggest that although the t10,c12-CLA isomer had beneficial effects on reducing adipocyte size in obese rats, this did not translate into changes in the local adipose RAS or associated adipokines.

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Adiponectin and leptin are secreted through distinct trafficking pathways in adipocytes.

    Science.gov (United States)

    Xie, Linglin; O'Reilly, Cormac P; Chapes, Stephen K; Mora, Silvia

    2008-02-01

    Adiponectin and leptin are two adipokines secreted by white adipose tissue that regulate insulin sensitivity. Previously we reported that adiponectin but not leptin release depends on GGA-coated vesicle formation, suggesting that leptin and adiponectin may follow different secretory routes. Here we have examined the intracellular trafficking pathways that lead to the secretion of these two hormones. While adiponectin and leptin displayed distinct localization in the steady-state, treatment of adipocytes with brefeldin A inhibited both adiponectin and leptin secretion to a similar level, indicating a common requirement for class III ADP-ribosylating factors and an intact Golgi apparatus. Adiponectin secretion was significantly reduced by endosomal inactivation in both 3T3L1 and rat isolated adipocytes, whereas this treatment had no effect on leptin secretion. Importantly, endosomal inactivation completely abolished the insulin stimulatory effect on adiponectin release in rat adipocytes. Confocal microscopy studies revealed colocalization of adiponectin with endogenous rab11 a marker for the recycling endosome, and with expressed rab5-GFP mutant (rab5Q75L) a marker for the early endosome compartment. Colocalization of adiponectin and rab5Q75L was increased in endosome inactivated cells. Consistent with these findings adiponectin secretion was reduced in cells expressing mutants of Rab11 and Rab5 proteins. In contrast, expression of an inactive (kinase dead) mutant of Protein Kinase D1 moderately but significantly inhibited leptin secretion without altering adiponectin secretion. Taken together, these results suggest that leptin and adiponectin secretion involve distinct intracellular compartments and that endosomal compartments are required for adiponectin but not for leptin secretion.

  1. Resveratrol induces apoptosis and inhibits adipogenesis in 3T3-L1 adipocytes.

    Science.gov (United States)

    Rayalam, Srujana; Yang, Jeong-Yeh; Ambati, Suresh; Della-Fera, Mary Anne; Baile, Clifton A

    2008-10-01

    Resveratrol, a phytoallexin, has recently been reported to slow aging by acting as a sirtuin activator. Resveratrol also has a wide range of pharmacological effects on adipocytes. In this study, we investigated the effects of resveratrol on adipogenesis and apoptosis using 3T3-L1 cells. In mature adipocytes, 100 and 200 microM resveratrol decreased cell viability dose-dependently by 23 +/- 2.7%, and 75.3 +/- 2.8% (p < 0.0001), respectively, after 48 h treatment, and 100 microM resveratrol increased apoptosis by 76 +/- 8.7% (p < 0.0001). Resveratrol at 25 and 50 microM decreased lipid accumulation in maturing preadipocytes significantly by 43 +/- 1.27% and 94.3 +/- 0.3% (p < 0.0001) and decreased cell viability by 25 +/- 1.3% and 70.4 +/- 1.6% (p < 0.0001), respectively. In order to understand the anti-adipogenic effects of resveratrol, maturing 3T3-L1 preadipocytes were treated with 25 microM resveratrol and the change in the expression of several adipogenic transcription factors and enzymes was investigated using real-time RT-PCR. Resveratrol down-regulated the expression of PPAR gamma, C/EBP alpha, SREBP-1c, FAS, HSL, LPL and up-regulated the expression of genes regulating mitochondrial activity (SIRT3, UCP1 and Mfn2). These results indicate that resveratrol may alter fat mass by directly affecting cell viability and adipogenesis in maturing preadipocytes and inducing apoptosis in adipocytes and thus may have applications for the treatment of obesity.

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

    Directory of Open Access Journals (Sweden)

    Ignazio eBarbagallo

    2016-01-01

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

  3. Effect of clenbuterol on apoptosis, adipogenesis, and lipolysis in adipocytes.

    Science.gov (United States)

    Kim, Hye-Kyeong; Della-Fera, Mary Anne; Hausman, Dorothy B; Baile, Clifton A

    2010-09-01

    Clenbuterol, a beta(2)-adrenergic receptor (beta(2)-AR) selective agonist, has been shown to decrease body fat in animals and can induce apoptosis in adipose tissue in mice. We hypothesized that direct actions of a beta-adrenergic receptor agonist on adipocytes could trigger the observed apoptotic effect. The hypothesis was inspected by investigating the direct effect of clenbuterol on apoptosis, adipogenesis, and lipolysis in vitro using the 3T3-L1 cell line and rat primary adipocytes. Cells were treated with 10(-9) to 10(-5) M clenbuterol depending on the experiments. There was no apoptotic effect of clenbuterol both in 3T3-L1 cells and rat primary adipocytes. Adipogenesis monitored by Oil Red O staining and AdipoRed assay was modestly decreased by clenbuterol treatment (p < 0.05). In fully differentiated primary adipocytes, clenbuterol increased basal lipolysis compared with the control (p < 0.01). In summary, direct stimulation of beta(2)-AR by clenbuterol does not cause apoptosis in adipocytes, despite a direct lipolytic stimulation and attenuation of adipogenesis.

  4. 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.

  5. Effect of pycnogenol on glucose transport in mature 3T3-L1 adipocytes.

    Science.gov (United States)

    Lee, Hee-Hyun; Kim, Kui-Jin; Lee, Ok-Hwan; Lee, Boo-Yong

    2010-08-01

    Pycnogenol, a procyanidins-enriched extract of Pinus maritima bark, possesses antidiabetic properties, which improves the altered parameters of glucose metabolism that are associated with type 2 diabetes mellitus (T2DM). Since the insulin-stimulated antidiabetic activities of natural bioactive compounds are mediated by GLUT4 via the phosphatidylinositol-3-kinase (PI3K) and/or p38 mitogen activated protein kinase (p38-MAPK) pathway, the effects of pycnogenol were examined on the molecular mechanism of glucose uptake by the glucose transport system. 3T3-L1 adipocytes were treated with various concentrations of pycnogenol, and glucose uptake was examined using a non-radioisotope enzymatic assay and by molecular events associated with the glucose transport system using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The results show that pycnogenol increased glucose uptake in fully differentiated 3T3-L1 adipocytes and increased the relative abundance of both GLUT4 and Akt mRNAs through the PI3K pathway in a dose dependent manner. Furthermore, pycnogenol restored the PI3K antagonist-induced inhibition of glucose uptake in the presence of wartmannin, an inhibitor of the PI3K. Overall, these results indicate that pycnogenol may stimulate glucose uptake via the PI3K dependent tyrosine kinase pathways involving Akt. Further the results suggest that pycnogenol might be useful in maintaining blood glucose control.

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

    Science.gov (United States)

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

    2015-10-15

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

  7. Enhancement of insulin sensitivity in adipocytes by ginger.

    Science.gov (United States)

    Sekiya, Keizo; Ohtani, Atsuko; Kusano, Shuichi

    2004-01-01

    Antidiabetic and hypoglycemic drugs have been reported to enhance adipocyte differentiation of 3T3-L1 preadipocytes. We previously reported that ginseng (active constituents: ginsenosides) enhanced the differentiation [1]. In this experiment, effect of some ginger group food extracts on the adipocyte differentiation was investigated using cultured mouse 3T3-L1 preadipocytes. 3T3-L1 cells were grown as monolayer cultures at 37 degrees C in DMEM supplemented by 10% FBS under the atmosphere of 5% CO(2)-95% air. Ginger extracts were found to enhance the adipocyte differentiation. Active constituent was purified and identified as gingerol. In the gingerol-treated cells, insulin-sensitive glucose uptake was increased. It is expected that ginger enhance the insulin-sensitivity, and improve chronic disease, such as diabetes.

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

    Science.gov (United States)

    Trayhurn, Paul; Alomar, Suliman Yousef

    2015-01-01

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

  9. Lipid droplets hypertrophy: A crucial determining factor in insulin regulation by adipocytes

    NARCIS (Netherlands)

    B. Sanjabi (B.); M. Dashty (Monireh); B. Özcan (Behiye); V. Akbarkhanzadeh (Vishtaseb); M. Rahimi (Mehran); M. Vinciguerra (Manlio); F. Van Rooij (Felix); S.H. Al-Lahhman (Sa'ad); F. Sheedfar (Fareeba); T.G. Van Kooten (Theo G.); C.A. Spek (Arnold); A.T. Rowshani (Ajda); J.J.L. van der Want (Johannes); R. Klaassen (Rene); E.J.G. Sijbrands (Eric); M.P. Peppelenbosch (Maikel); F. Rezaee (Farhad)

    2015-01-01

    textabstractLipid droplets (LDs) hypertrophy in adipocytes is the main cause of energy metabolic system dysfunction, obesity and its afflictions such as T2D. However, the role of adipocytes in linking energy metabolic disorders with insulin regulation is unknown in humans. Human adipocytes constitut

  10. Maraviroc reduces cytokine expression and secretion in human adipose cells without altering adipogenic differentiation.

    Science.gov (United States)

    Díaz-Delfín, Julieta; Domingo, Pere; Giralt, Marta; Villarroya, Francesc

    2013-03-01

    Maraviroc (MVC) is a drug approved for use as part of HAART in treatment-experienced HIV-1 patients with CCR5-tropic virus. Despite the current concerns on the alterations in adipose tissue that frequently appear in HIV-infected patients under HAART, there is no information available on the effects of MVC on adipose tissue. Here we studied the effects of MVC during and after the differentiation of human adipocytes in culture, and compared the results with the effects of efavirenz (EFV). We measured the acquisition of adipocyte morphology; the gene expression levels of markers for mitochondrial toxicity, adipogenesis and inflammation; and the release of adipokines and cytokines to the medium. Additionally, we determined the effects of MVC on lipopolysaccharide (LPS)-induced pro-inflammatory cytokine expression in adipocytes. Unlike EFV-treated pre-adipocytes, MVC-treated pre-adipocytes showed no alterations in the capacity to differentiate into adipocytes and accumulated lipids normally. Consistent with this, there were no changes in the mRNA levels of PPARγ or SREBP-1c, two master regulators of adipogenesis. In addition, MVC caused a significant decrease in the gene expression and release of pro-inflammatory cytokines, whereas EFV had the opposite effect. Moreover, MVC lowered inflammation-related gene expression and inhibited the LPS-induced expression of pro-inflammatory genes in differentiated adipocytes. We conclude that MVC does not alter adipocyte differentiation but rather shows anti-inflammatory properties by inhibiting the expression and secretion of pro-inflammatory cytokines. Collectively, our results suggest that MVC may minimize adverse effects on adipose tissue development, metabolism, and inflammation, and thus could be a potentially beneficial component of antiretroviral therapy.

  11. Development of an OP9 derived cell line as a robust model to rapidly study adipocyte differentiation.

    Directory of Open Access Journals (Sweden)

    Jacqueline M Lane

    Full Text Available One hallmark of obesity is adipocyte hypertrophy and hyperplasia. To gain novel insights into adipose biology and therapeutics, there is a pressing need for a robust, rapid, and informative cell model of adipocyte differentiation for potential RNAi and drug screens. Current models are prohibitive for drug and RNAi screens due to a slow differentiation time course and resistance to transfection. We asked if we could create a rapid, robust model of adipogenesis to potentially enable rapid functional and obesity therapeutic screens. We generated the clonal population OP9-K, which differentiates rapidly and reproducibly, and displays classic adipocyte morphology: rounded cell shape, lipid accumulation, and coalescence of lipids into a large droplet. We further validate the OP9-K cells as an adipocyte model system by microarray analysis of the differentiating transcriptome. OP9-K differentiates via known adipogenic pathways, involving the transcriptional activation and repression of common adipose markers Plin1, Gata2, C/Ebpα and C/Ebpβ and biological pathways, such as lipid metabolism, PPARγ signaling, and osteogenesis. We implemented a method to quantify lipid accumulation using automated microscopy and tested the ability of our model to detect alterations in lipid accumulation by reducing levels of the known master adipogenic regulator Pparγ. We further utilized our model to query the effects of a novel obesity therapeutic target, the transcription factor SPI1. We determine that reduction in levels of Spi1 leads to an increase in lipid accumulation. We demonstrate rapid, robust differentiation and efficient transfectability of the OP9-K cell model of adipogenesis. Together with our microscopy based lipid accumulation assay, adipogenesis assays can be achieved in just four days' time. The results of this study can contribute to the development of rapid screens with the potential to deepen our understanding of adipose biology and efficiently

  12. 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

  13. Ultra-structure of adipocytes in the digital cushion of ostrich (Stuthio Camelus foot pad

    Directory of Open Access Journals (Sweden)

    Amira Eid Derbalah

    2012-02-01

    Full Text Available The ultra-structural examination of adipocytes in the digital cushion of ostrich foot pad was performed to reveal the structural adaptation of adipocytes and elastic fibers of digital cushion to accommodate with fast movement of this unique bird. Two types of adipocytes were found, the first type was typical signet ring cells which had large fat droplets whose dimension dwarfed the cell organelles. The second type was diffused form with oval shaped adipocytes. Microfibillar aggregates of elastic fibers were closely packed and appeared to bead in a regular fashion. Some of this microfibrillar was reshaping adipocytes by making invagination of their plasma membrane.

  14. Pathophysiology of Adipocyte Defects and Dyslipidemia in HIV Lipodystrophy: New Evidence from Metabolic and Molecular Studies

    Directory of Open Access Journals (Sweden)

    Ashok Balasubramanyam

    2006-01-01

    Full Text Available Despite a burgeoning mass of descriptive information regarding the epidemiology, clinical features, body composition changes, hormonal alterations and dyslipidemic patterns in patients with HIV lipodystrophy syndrome (HLS, the specific biochemical pathways that are dysregulated in the condition and the molecular mechanisms that lead to their dysfunction, remain relatively unexplored. In this paper, we review studies that detail the metabolic basis of the dyslipidemia - specifically, the hypertriglyceridemia - that is the serologic hallmark of HLS and present new data relevant to mechanisms of dyslipidemia in the postprandial state. We also describe preliminary experiments showing that in addition to the well-known effects of highly-active antiretroviral drugs, the functional disruption of adipocytes and preadipocytes by factors intrinsic to HIV-infected immunocytes may play a role in the pathogenesis of HLS.

  15. Prednisolone induces the Wnt signalling pathway in 3T3-L1 adipocytes.

    Science.gov (United States)

    Fleuren, Wilco W M; Linssen, Margot M L; Toonen, Erik J M; van der Zon, Gerard C M; Guigas, Bruno; de Vlieg, Jacob; Dokter, Wim H A; Ouwens, D Margriet; Alkema, Wynand

    2013-05-01

    Synthetic glucocorticoids are potent anti-inflammatory drugs but show dose-dependent metabolic side effects such as the development of insulin resistance and obesity. The precise mechanisms involved in these glucocorticoid-induced side effects, and especially the participation of adipose tissue in this are not completely understood. We used a combination of transcriptomics, antibody arrays and bioinformatics approaches to characterize prednisolone-induced alterations in gene expression and adipokine secretion, which could underlie metabolic dysfunction in 3T3-L1 adipocytes. Several pathways, including cytokine signalling, Akt signalling, and Wnt signalling were found to be regulated at multiple levels, showing that these processes are targeted by prednisolone. These results suggest that mechanisms by which prednisolone induce insulin resistance include dysregulation of wnt signalling and immune response processes. These pathways may provide interesting targets for the development of improved glucocorticoids.

  16. Protein Kinase A Subunit Balance Regulates Lipid Metabolism in Caenorhabditis elegans and Mammalian Adipocytes.

    Science.gov (United States)

    Lee, Jung Hyun; Han, Ji Seul; Kong, Jinuk; Ji, Yul; Lv, Xuchao; Lee, Junho; Li, Peng; Kim, Jae Bum

    2016-09-23

    Protein kinase A (PKA) is a cyclic AMP (cAMP)-dependent protein kinase composed of catalytic and regulatory subunits and involved in various physiological phenomena, including lipid metabolism. Here we demonstrated that the stoichiometric balance between catalytic and regulatory subunits is crucial for maintaining basal PKA activity and lipid homeostasis. To uncover the potential roles of each PKA subunit, Caenorhabditis elegans was used to investigate the effects of PKA subunit deficiency. In worms, suppression of PKA via RNAi resulted in severe phenotypes, including shortened life span, decreased egg laying, reduced locomotion, and altered lipid distribution. Similarly, in mammalian adipocytes, suppression of PKA regulatory subunits RIα and RIIβ via siRNAs potently stimulated PKA activity, leading to potentiated lipolysis without increasing cAMP levels. Nevertheless, insulin exerted anti-lipolytic effects and restored lipid droplet integrity by antagonizing PKA action. Together, these data implicate the importance of subunit stoichiometry as another regulatory mechanism of PKA activity and lipid metabolism.

  17. Early-life origins of metabolic dysfunction: role of the adipocyte.

    Science.gov (United States)

    Muhlhausler, Beverly; Smith, Steven R

    2009-03-01

    More than 60% of adults in the US are classified as overweight, with most developing associated metabolic problems. It is increasingly clear that the origins of obesity and metabolic disease are early in life, yet the physiological basis for this is not well understood. We propose that perturbations to nutrient supply in utero affect adipocyte development, altering functional properties and promoting excess body fat accumulation after birth. We also propose that excessive body fat accumulation leads to leptin and insulin resistance in these individuals, rendering them more susceptible to further weight gain and metabolic deterioration. Finally, we propose that interventions that inhibit this early increase in fat deposition have the potential to interrupt the pathway to obesity.

  18. Dietary effects on adipocyte metabolism and epigenetics

    Science.gov (United States)

    Obesity risk appears to be perpetuated across generations by way of programmed DNA alterations that occur in utero and that affect gene expression throughout the life span. Studies have demonstrated associations of maternal obesity and epigenetic changes, such as DNA methylation, histone modifica...

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

    Science.gov (United States)

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

    2008-04-01

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

  20. Mesothelial cell differentiation into osteoblast- and adipocyte-like cells.

    Science.gov (United States)

    Lansley, Sally M; Searles, Richelle G; Hoi, Aina; Thomas, Carla; Moneta, Helena; Herrick, Sarah E; Thompson, Philip J; Newman, Mark; Sterrett, Gregory F; Prêle, Cecilia M; Mutsaers, Steven E

    2011-10-01

    Serosal pathologies including malignant mesothelioma (MM) can show features of osseous and/or cartilaginous differentiation although the mechanism for its formation is unknown. Mesothelial cells have the capacity to differentiate into cells with myofibroblast, smooth muscle and endothelial cell characteristics. Whether they can differentiate into other cell types is unclear. This study tests the hypothesis that mesothelial cells can differentiate into cell lineages of the embryonic mesoderm including osteoblasts and adipocytes. To examine this, a functional assay of bone formation and an adipogenic assay were performed in vitro with primary rat and human mesothelial cells maintained in osteogenic or adipogenic medium (AM) for 0-26 days. Mesothelial cells expressed increasing levels of alkaline phosphatase, an early marker of the osteoblast phenotype, and formed mineralized bone-like nodules. Mesothelial cells also accumulated lipid indicative of a mature adipocyte phenotype when cultured in AM. All cells expressed several key osteoblast and adipocyte markers, including osteoblast-specific runt-related transcription factor 2, and demonstrated changes in mRNA expression consistent with epithelial-to-mesenchymal transition. In conclusion, these studies confirm that mesothelial cells have the capacity to differentiate into osteoblast- and adipocyte-like cells, providing definitive evidence of their multipotential nature. These data strongly support mesothelial cell differentiation as the potential source of different tissue types in MM tumours and other serosal pathologies, and add support for the use of mesothelial cells in regenerative therapies.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  2. Adipocytes promote prostate cancer stem cell self-renewal through amplification of the cholecystokinin autocrine loop.

    Science.gov (United States)

    Tang, Kai-Dun; Liu, Ji; Jovanovic, Lidija; An, Jiyuan; Hill, Michelle M; Vela, Ian; Lee, Terence Kin-Wah; Ma, Stephanie; Nelson, Colleen; Russell, Pamela J; Clements, Judith A; Ling, Ming-Tat

    2016-01-26

    Obesity has long been linked with prostate cancer progression, although the underlying mechanism is still largely unknown. Here, we report that adipocytes promote the enrichment of prostate cancer stem cells (CSCs) through a vicious cycle of autocrine amplification. In the presence of adipocytes, prostate cancer cells actively secrete the peptide hormone cholecystokinin (CCK), which not only stimulates prostate CSC self-renewal, but also induces cathepsin B (CTSB) production of the adipocytes. In return, CTSB facilitates further CCK secretion by the cancer cells. More importantly, inactivation of CCK receptor not only suppresses CTSB secretion by the adipocytes, but also synergizes the inhibitory effect of CTSB inhibitor on adipocyte-promoted prostate CSC self-renewal. In summary, we have uncovered a novel mechanism underlying the mutual interplay between adipocytes and prostate CSCs, which may help explaining the role of adipocytes in prostate cancer progression and provide opportunities for effective intervention.

  3. [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

  4. Effects of Kurozu concentrated liquid on adipocyte size in rats

    Directory of Open Access Journals (Sweden)

    Nakamura Kumi

    2010-11-01

    Full Text Available Abstract Background Kurozu concentrated liquid (KCL is used as a health-promoting supplement for the treatment of disorders such as cancer, hyperlipidemia, and hypertension in Japan. We investigated the possible anti-obesity effects of KCL in rats. Methods Male Sprague Dawley rats were fed American Institute of Nutrition 76 formula diet and were orally administrated KCL or acetic acid at a dose of 100 mg/kg body weight or deionized water for 4 weeks. Adipocyte size, DNA content in subcutaneous adipose tissue, lipid levels in the serum and liver, and the rate of fatty acid excretion were determined. Effects of KCL on pancreatic lipase activity and 3T3-L1 preadipocyte differentiation were investigated in vitro. Results In the KCL group, the average adipocyte size in subcutaneous and perirenal adipose tissues was significantly reduced. The KCL-administered rats displayed greater numbers of small adipocytes in the subcutaneous, perirenal and mesenteric adipose tissues than did rats from the other groups. In the KCL group, the DNA content in subcutaneous adipose tissue was significantly increased. The rate of fatty acid excretion was significantly increased in the KCL group. Furthermore, KCL significantly inhibited pancreatic lipase activity in vitro, and also significantly inhibited fat accumulation and mRNA expression of fatty acid binding protein 2 (aP2 and peroxisome proliferator-activated γ (PPARγ in 3T3-L1 preadipocyte. The levels of serum and liver lipids, the concentration of serum glucose, and the levels of adiponectin were similar among the 3 groups. Conclusion Oral administration of KCL decreases the adipocyte size via inhibition of dietary fat absorption and reductions of PPARγ and aP2 mRNA expression levels in adipocytes.

  5. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Rubén Cereijo

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

  8. Gene expression profiling in multipotent DFAT cells derived from mature adipocytes.

    Science.gov (United States)

    Ono, Hiromasa; Oki, Yoshinao; Bono, Hidemasa; Kano, Koichiro

    2011-04-15

    Cellular dedifferentiation signifies the withdrawal of cells from a specific differentiated state to a stem cell-like undifferentiated state. However, the mechanism of dedifferentiation remains obscure. Here we performed comparative transcriptome analyses during dedifferentiation in mature adipocytes (MAs) to identify the transcriptional signatures of multipotent dedifferentiated fat (DFAT) cells derived from MAs. Using microarray systems, we explored similarly expressed as well as significantly differentially expressed genes in MAs during dedifferentiation. This analysis revealed significant changes in gene expression during this process, including a significant reduction in expression of genes for lipid metabolism concomitantly with a significant increase in expression of genes for cell movement, cell migration, tissue developmental processes, cell growth, cell proliferation, cell morphogenesis, altered cell shape, and cell differentiation. Our observations indicate that the transcriptional signatures of DFAT cells derived from MAs are summarized in terms of a significant decrease in functional phenotype-related genes and a parallel increase in cell proliferation, altered cell morphology, and regulation of the differentiation of related genes. A better understanding of the mechanisms involved in dedifferentiation may enable scientists to control and possibly alter the plasticity of the differentiated state, which may lead to benefits not only in stem cell research but also in regenerative medicine.

  9. Comparison of the adipogenesis in intramuscular and subcutaneous adipocytes from Bamei and Landrace pigs.

    Science.gov (United States)

    Zhang, Guo Hua; Lu, Jian Xiong; Chen, Yan; Zhao, Yong Qing; Guo, Peng Hui; Yang, Ju Tian; Zang, Rong Xin

    2014-08-01

    Fat deposition is a complex process involving proliferation, differentiation, and lipogenesis of adipocytes. Bamei and Landrace are considered to represent fat- and lean-type pig breeds. Subcutaneous (SC) and intramuscular (IM) pre-adipocytes were cultured to compare the proliferation and lipogenesis in these breeds. The differentiated adipocytes were exposed to glucose or insulin to evaluate their effects on lipogenesis and lipogenic gene expression. Pre-adipocytes proliferated dramatically faster in SC vs. IM cells, and in Bamei vs. Landrace breeds. Lipogenesis and lipogenic gene expression had a greater increase in Bamei than in Landrace, and in SC vs. IM in the process of differentiation. Glucose markedly promoted lipogenesis and lipogenic gene expression in differentiated adipocytes. The stimulation of high-glucose levels on lipogenesis and ChREBP and lipogenic gene expression was higher in SC than IM adipocytes, and in Bamei vs. Landrace. Insulin largely increased SREBP-1c expression, however it modestly stimulated lipogenesis and lipogenic gene expression, and there was no difference between cell populationsor between breeds. These data demonstrated that regional and varietal differences obviously existed in the development of porcine adipocytes. The proliferation and differentiation capacity of pre-adipocytes, and the adipocyte lipogenesis stimulated by glucose, are stronger in Bamei than Landrace, and in SC vs. IM adipocytes independent of breed.

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

    Science.gov (United States)

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

    2016-01-01

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

  11. Adipocyte telomere length associates negatively with adipocyte size, whereas adipose tissue telomere length associates negatively with the extent of fibrosis in severely obese women.

    Science.gov (United States)

    el Bouazzaoui, F; Henneman, P; Thijssen, P; Visser, A; Koning, F; Lips, M A; Janssen, I; Pijl, H; Willems van Dijk, K; van Harmelen, V

    2014-05-01

    Telomere length can be considered as a biological marker for cell proliferation and aging. Obesity is associated with adipocyte hypertrophy and proliferation as well as with shorter telomeres in adipose tissue. As adipose tissue is a mixture of different cell types and the cellular composition of adipose tissue changes with obesity, it is unclear what determines telomere length of whole adipose tissue. We aimed to investigate telomere length in whole adipose tissue and isolated adipocytes in relation to adiposity, adipocyte hypertrophy and adipose tissue inflammation and fibrosis. Telomere length was measured by real-time PCR in visceral adipose tissue, and isolated adipocytes of 21 obese women with a waist ranging from 110 to 147 cm and age from 31 to 61 years. Telomere length in adipocytes was shorter than in whole adipose tissue. Telomere length of adipocytes but not whole adipose tissue correlated negatively with waist and adipocyte size, which was still significant after correction for age. Telomere length of whole adipose tissue associated negatively with fibrosis as determined by collagen content. Thus, in extremely obese individuals, adipocyte telomere length is a marker of adiposity, whereas whole adipose tissue telomere length reflects the extent of fibrosis and may indicate adipose tissue dysfunction.

  12. Sida rhomboidea. Roxb leaf extract down-regulates expression of PPARγ2 and leptin genes in high fat diet fed C57BL/6J Mice and retards in vitro 3T3L1 pre-adipocyte differentiation.

    Science.gov (United States)

    Thounaojam, Menaka C; Jadeja, Ravirajsinh N; Ramani, Umed V; Devkar, Ranjitsinh V; Ramachandran, A V

    2011-01-01

    Sida rhomboidea. Roxb leaf extract (SRLE) is being used by the populace of North-East India to alleviate symptoms of diabetes and obesity. We have previously reported its hypolipidemic and anti-diabetic properties. In this study, we report the effect of SRLE on (i) in vivo modulation of genes controlling high fat diet (HFD) induced obesity and (ii) in vitro 3T3L1 pre-adipocyte differentiation and leptin release. Supplementation with SRLE significantly prevented HFD induced increment in bodyweight, plasma lipids and leptin, visceral adiposity and adipocyte hypertrophy. Also, SRLE supplementation reduced food intake, down regulated PPARγ2, SREBP1c, FAS and LEP expressions and up-regulated CPT-1 in epididymal adipose tissue compared to obese mice. In vitro adipogenesis of 3T3L1 pre-adipocytes was significantly retarded in the presence of SRLE extract. Also decreased triglyceride accumulation, leptin release and glyceraldehyde-3-Phosphate dehydrogenase activity along with higher glycerol release without significant alteration of viability of 3T3L1 pre-adipocytes, was recorded. Our findings suggest that prevention of HFD induced visceral adiposity is primarily by down regulation of PPARγ2 and leptin gene expression coupled with attenuation of food intake in C57BL/6J mice. SRLE induced prevention of pre-adipocytes differentiation, and leptin release further substantiated these findings and scientifically validates the potential application of SRLE as a therapeutic agent against obesity.

  13. Sida rhomboidea. Roxb Leaf Extract Down-Regulates Expression of PPARγ2 and Leptin Genes in High Fat Diet Fed C57BL/6J Mice and Retards in Vitro 3T3L1 Pre-Adipocyte Differentiation

    Directory of Open Access Journals (Sweden)

    A. V. Ramachandran

    2011-07-01

    Full Text Available Sida rhomboidea. Roxb leaf extract (SRLE is being used by the populace of North-East India to alleviate symptoms of diabetes and obesity. We have previously reported its hypolipidemic and anti-diabetic properties. In this study, we report the effect of SRLE on (i in vivo modulation of genes controlling high fat diet (HFD induced obesity and (ii in vitro 3T3L1 pre-adipocyte differentiation and leptin release. Supplementation with SRLE significantly prevented HFD induced increment in bodyweight, plasma lipids and leptin, visceral adiposity and adipocyte hypertrophy. Also, SRLE supplementation reduced food intake, down regulated PPARγ2, SREBP1c, FAS and LEP expressions and up-regulated CPT-1 in epididymal adipose tissue compared to obese mice. In vitro adipogenesis of 3T3L1 pre-adipocytes was significantly retarded in the presence of SRLE extract. Also decreased triglyceride accumulation, leptin release and glyceraldehyde-3-Phosphate dehydrogenase activity along with higher glycerol release without significant alteration of viability of 3T3L1 pre-adipocytes, was recorded. Our findings suggest that prevention of HFD induced visceral adiposity is primarily by down regulation of PPARγ2 and leptin gene expression coupled with attenuation of food intake in C57BL/6J mice. SRLE induced prevention of pre-adipocytes differentiation, and leptin release further substantiated these findings and scientifically validates the potential application of SRLE as a therapeutic agent against obesity.

  14. Both inflammatory and classical lipolytic pathways are involved in lipopolysaccharide-induced lipolysis in human adipocytes.

    Science.gov (United States)

    Grisouard, Jean; Bouillet, Elisa; Timper, Katharina; Radimerski, Tanja; Dembinski, Kaethi; Frey, Daniel M; Peterli, Ralph; Zulewski, Henryk; Keller, Ulrich; Müller, Beat; Christ-Crain, Mirjam

    2012-02-01

    High fat diet-induced endotoxaemia triggers low-grade inflammation and lipid release from adipose tissue. This study aims to unravel the cellular mechanisms leading to the lipopolysaccharide (LPS) effects in human adipocytes. Subcutaneous pre-adipocytes surgically isolated from patients were differentiated into mature adipocytes in vitro. Lipolysis was assessed by measurement of glycerol release and mRNA expression of pro-inflammatory cytokines were evaluated by real-time PCR. Treatment with LPS for 24 h induced a dose-dependent increase in interleukin (IL)-6 and IL-8 mRNA expression. At 1 µg/ml LPS, IL-6 and IL-8 were induced to 19.5 ± 1.8-fold and 662.7 ± 91.5-fold (P < 0.01 vs basal), respectively. From 100 ng/ml to 1 µg/ml, LPS-induced lipolysis increased to a plateau of 3.1-fold above basal level (P < 0.001 vs basal). Co-treatment with inhibitors of inhibitory kappa B kinase kinase beta (IKKβ) or NF-κB inhibited LPS-induced glycerol release. Co-treatment with the protein kinase A (PKA) inhibitor H-89, the lipase inhibitor orlistat or the hormone-sensitive lipase (HSL) inhibitor CAY10499 abolished the lipolytic effects of LPS. Co-treatment with the MAPK inhibitor, U0126 also reduced LPS-induced glycerol release. Inhibition of lipolysis by orlistat or CAY10499 reduced LPS-induced IL-6 and IL-8 mRNA expression. Induction of lipolysis by the synthetic catecholamine isoproterenol or the phosphodiesterase type III inhibitor milrinone did not alter basal IL-6 and IL-8 mRNA expression after 24 treatments whereas these compounds enhanced LPS-induced IL-6 and IL-8 mRNA expression. Both the inflammatory IKKβ/NF-κB pathway and the lipolytic PKA/HSL pathways mediate LPS-induced lipolysis. In turn, LPS-induced lipolysis reinforces the expression of pro-inflammatory cytokines and, thereby, triggers its own lipolytic activity.

  15. Regulatory circuits controlling white versus brown adipocyte differentiation

    DEFF Research Database (Denmark)

    Hansen, Jacob B; Kristiansen, Karsten

    2006-01-01

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

  16. Insulin and insulin mutants stimulate glucose uptake in rat adipocytes

    Institute of Scientific and Technical Information of China (English)

    姚矢音; 张新堂; 许英镐; 张信娜; 朱尚权

    1999-01-01

    A simple method to determine the in vitro biological activity of insulin by measuring glucose uptake in the rat adipocytes is presented here. In the presence of insulin, the glucose uptake is 5-6 times more than the basal control. And the uptake of D-[3-3H]-glucose is linear as the logarithm of insulin concentration from 0.2 μg/L to 1.0 μg/L. Glucose and 3-O-methyl-glucose inhibit D-[3-3H]-glucose uptake into adipocytes. By this method, the in vitro biological activity of [B2-Lys]-insulin and [B3-Lys]-insulin was measured to be 61.6% and 154% respectively, relative to that of insulin.

  17. 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.

  18. Chemerin Regulates Crosstalk Between Adipocytes and Vascular Cells Through Nox.

    Science.gov (United States)

    Neves, Karla Bianca; Nguyen Dinh Cat, Aurelie; Lopes, Rheure Alves Moreira; Rios, Francisco Jose; Anagnostopoulou, Aikaterini; Lobato, Nubia Souza; de Oliveira, Ana Maria; Tostes, Rita C; Montezano, Augusto C; Touyz, Rhian M

    2015-09-01

    Adipocytes produce adipokines, including chemerin, a chemoattractant that mediates effects through its ChemR23 receptor. Chemerin has been linked to endothelial dysfunction and vascular injury in pathological conditions, such as obesity, diabetes mellitus, and hypertension. Molecular mechanisms underlying this are elusive. Here we assessed whether chemerin through redox-sensitive signaling influences molecular processes associated with vascular growth, apoptosis, and inflammation. Human microvascular endothelial cells and vascular smooth muscle cells were stimulated with chemerin (50 ng/mL). Chemerin increased generation of reactive oxygen species and phosphorylation of mitogen-activated protein kinases, effects that were inhibited by ML171, GKT137831 (Nox inhibitors), and N-acetylcysteine (reactive oxygen species scavenger). Chemerin increased mRNA expression of proinflammatory mediators in vascular cells and increased monocyte-to-endothelial cell attachment. In human vascular smooth muscle cells, chemerin induced phosphorylation of mitogen-activated protein kinases and stimulated proliferation (increased proliferating cell nuclear antigen expression [proliferation marker] and BrdU incorporation [proliferation assay]). Chemerin decreased phosphatidylinositol 3-kinase/protein kinase B activation and increased TUNEL-positive human vascular smooth muscle cells. In human microvascular endothelial cells, chemerin reduced endothelial nitric oxide synthase activity and nitric oxide production. Adipocyte-conditioned medium from obese/diabetic mice (db/db), which have elevated chemerin levels, increased reactive oxygen species generation in vascular smooth muscle cells, whereas adipocyte-conditioned medium from control mice had no effect. Chemerin actions were blocked by CCX 832, a ChemR23 inhibitor. Our data demonstrate that chemerin, through Nox activation and redox-sensitive mitogen-activated protein kinases signaling, exerts proapoptotic, proinflammatory, and

  19. Bacterial Translocation – Impact on the Adipocyte Compartment

    Science.gov (United States)

    Kruis, Tassilo; Batra, Arvind; Siegmund, Britta

    2013-01-01

    Over the last decade it became broadly recognized that adipokines and thus the fat tissue compartment exert a regulatory function on the immune system. Our own group described the pro-inflammatory function of the adipokine leptin within intestinal inflammation in a variety of animal models. Following-up on this initial work, the aim was to reveal stimuli and mechanisms involved in the activation of the fat tissue compartment and the subsequent release of adipokines and other mediators paralleled by the infiltration of immune cells. This review will summarize the current literature on the possible role of the mesenteric fat tissue in intestinal inflammation with a focus on Crohn’s disease (CD). CD is of particular interest in this context since the transmural intestinal inflammation has been associated with a characteristic hypertrophy of the mesenteric fat, a phenomenon called “creeping fat.” The review will address three consecutive questions: (i) What is inducing adipocyte activation, (ii) which factors are released after activation and what are the consequences for the local fat tissue compartment and infiltrating cells; (iii) do the answers generated before allow for an explanation of the role of the mesenteric fat tissue within intestinal inflammation? With this review we will provide a working model indicating a close interaction in between bacterial translocation, activation of the adipocytes, and subsequent direction of the infiltrating immune cells. In summary, the models system mesenteric fat indicates a unique way how adipocytes can directly interact with the immune system. PMID:24432024

  20. 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.

  1. Effects of Rosmarinus officinalis extract on human primary omental preadipocytes and adipocytes.

    Science.gov (United States)

    Stefanon, Bruno; Pomari, Elena; Colitti, Monica

    2015-07-01

    The prevalence of obesity is increasing all over the world. Although it has been shown that natural substances influence fat metabolism, little is known about the effect on cellular and molecular mechanisms in human. In this in vitro study, the activity of Rosmarinus officinalis (RO) standardized extract in modulating human primary visceral preadipocytes differentiation, lipolysis, and apoptosis was investigated. Moreover, gene expression of key adipogenesis modulators and microRNAs-seq were evaluated. Preadipocytes treated with RO extract significantly reduced triglyceride incorporation during maturation in a dose-dependent manner without affecting cell viability. In addition, RO extract stimulated lipolytic activity in differentiating preadipocytes and mature adipocytes in treated cells compared to controls. Differentiating preadipocytes incubated in the presence of RO extract showed a decreased expression of cell cycle genes such as cyclin D1, cyclin-dependent kinase 4, cyclin-dependent kinase inhibitor 1A (p21, Cip1) and an increased expression of GATA binding protein 3, wingless-type MMTV integration site family, member 3A mRNA levels. Recent studies have demonstrated that some phytochemicals alter the expression of specific genes and microRNAs that play a fundamental role in the pathogenesis of obesity and related diseases. Interestingly, genes modulated in RO-treated cells were found to be validated miRNAs targets, such as let-7f-1, miR-17, and miR-143. The results indicated that RO extract modulates human adipocyte differentiation and significantly interferes with adipogenesis and lipid metabolism, supporting its interest as dietary supplement.

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

    Science.gov (United States)

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

    2010-06-01

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

  3. Glutamine synthetase desensitizes differentiated adipocytes to proinflammatory stimuli by raising intracellular glutamine levels.

    Science.gov (United States)

    Palmieri, Erika Mariana; Spera, Iolanda; Menga, Alessio; Infantino, Vittoria; Iacobazzi, Vito; Castegna, Alessandra

    2014-12-20

    The role of glutamine synthetase (GS) during adipocyte differentiation is unclear. Here, we assess the impact of GS on the adipocytic response to a proinflammatory challenge at different differentiation stages. GS expression at the late stages of differentiation desensitized mature adipocytes to bacterial lipopolysaccharide (LPS) by increasing intracellular glutamine levels. Furthermore, LPS-activated mature adipocytes were unable to produce inflammatory mediators; LPS sensitivity was rescued following GS inhibition and the associated drop in intracellular glutamine levels. The ability of adipocytes to differentially respond to LPS during differentiation negatively correlates to GS expression and intracellular glutamine levels. Hence, modulation of intracellular glutamine levels by GS expression represents an endogenous mechanism through which mature adipocytes control the inflammatory response.

  4. Characterization of adipocyte differentiation from human mesenchymal stem cells in bone marrow

    Directory of Open Access Journals (Sweden)

    Huang Hai-Yan

    2010-05-01

    Full Text Available Abstract Background Adipocyte hyperplasia is associated with obesity and arises due to adipogenic differentiation of resident multipotent stem cells in the vascular stroma of adipose tissue and remote stem cells of other organs. The mechanistic characterization of adipocyte differentiation has been researched in murine pre-adipocyte models (i.e. 3T3-L1 and 3T3-F442A, revealing that growth-arrest pre-adipocytes undergo mitotic clonal expansion and that regulation of the differentiation process relies on the sequential expression of three key transcription factors (C/EBPβ, C/EBPα and PPARγ. However, the mechanisms underlying adipocyte differentiation from multipotent stem cells, particularly human mesenchymal stem cells (hBMSCs, remain poorly understood. This study investigated cell cycle regulation and the roles of C/EBPβ, C/EBPα and PPARγ during adipocyte differentiation from hBMSCs. Results Utilising a BrdU incorporation assay and manual cell counting it was demonstrated that induction of adipocyte differentiation in culture resulted in 3T3-L1 pre-adipocytes but not hBMSCs undergoing mitotic clonal expansion. Knock-down and over-expression assays revealed that C/EBPβ, C/EBPα and PPARγ were required for adipocyte differentiation from hBMSCs. C/EBPβ and C/EBPα individually induced adipocyte differentiation in the presence of inducers; PPARγ alone initiated adipocyte differentiation but the cells failed to differentiate fully. Therefore, the roles of these transcription factors during human adipocyte differentiation are different from their respective roles in mouse. Conclusions The characteristics of hBMSCs during adipogenic differentiation are different from those of murine cells. These findings could be important in elucidating the mechanisms underlying human obesity further.

  5. 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

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

    Science.gov (United States)

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

    2014-01-01

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

  7. Dedifferentiated adipocyte-derived progeny cells (DFAT cells): Potential stem cells of adipose tissue.

    Science.gov (United States)

    Wei, Shengjuan; Zan, Linsen; Hausman, Gary J; Rasmussen, Theodore P; Bergen, Werner G; Dodson, Michael V

    2013-07-01

    Analyses of mature adipocytes have shown that they possess a reprogramming ability in vitro, which is associated with dedifferentiation. The subsequent dedifferentiated fat cells (DFAT cells) are multipotent and can differentiate into adipocytes and other cell types as well. Mature adipocytes can be easily obtained by biopsy, and the cloned progeny cells are homogeneous in vitro. Therefore, DFAT cells (a new type of stem cell) may provide an excellent source of cells for tissue regeneration, engineering and disease treatment. The dedifferentiation of mature adipocytes, the multipotent capacity of DFAT cells and comparisons and contrasts with mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPS) are discussed in this review.

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

    Science.gov (United States)

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

    2014-05-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  10. Fat intake leads to differential response of rat adipocytes to glucose, insulin and ascorbic acid.

    Science.gov (United States)

    Garcia-Diaz, Diego F; Campion, Javier; Arellano, Arianna V; Milagro, Fermin I; Moreno-Aliaga, Maria J; Martinez, J Alfredo

    2012-04-01

    Antioxidant-based treatments have emerged as novel and interesting approaches to counteract fat accumulation in obesity and associated metabolic disturbances. Adipocytes from rats that were fed on chow or high-fat diet (HFD) for 50 d were isolated (primary adipocytes) and incubated (72 h) on low (LG; 5.6 mmol/L) or high (HG; 25 mmol/L) glucose levels, in the presence or absence of 1.6 nmol/L insulin and 200 μmol/L vitamin C (VC). Adipocytes from HFD-fed animals presented lower insulin-induced glucose uptake, lower lactate and glycerol release, and lower insulin-induced secretion of some adipokines as compared with controls. HG treatment restored the blunted response to insulin regarding apelin secretion in adipocytes from HFD-fed rats. VC treatment inhibited the levels of nearly all variables, irrespective of the adipocytes' dietary origin. The HG treatment reduced adipocyte viability, and VC protected from this toxic effect, although more drastically in control adipocytes. Summing up, in vivo chow or HFD intake determines a differential response to insulin and glucose treatments that appears to be dependent on the insulin-resistance status of the adipocytes, while VC modifies some responses from adipocytes independently of the previous dietary intake of the animals.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  12. Translocator protein (18 kDa) as a pharmacological target in adipocytes to regulate glucose homeostasis.

    Science.gov (United States)

    Li, Jiehan; Papadopoulos, Vassilios

    2015-09-01

    As a major regulator in obesity and its associated metabolic complications, the proper functioning of adipocytes is crucial for health maintenance, thus serving as an important target for the development of anti-obese and anti-diabetic therapies. There is increasing evidence that mitochondrial malfunction is a pivotal event in disturbing adipocyte cell homeostasis. Among major mitochondrial structure components, the high-affinity drug- and cholesterol-binding outer mitochondrial membrane translocator protein (18 kDa; TSPO) has shown importance across a broad spectrum of mitochondrial functions. Recent studies demonstrated the presence of TSPO in white adipocyte mitochondria of mice, and administration of TSPO drug ligands to obese mice reduced weight gain and lowered glucose level. Therefore, it is of great interest to assess whether TSPO in adipocytes could serve as a drug target to regulate adipocyte activities with potential influence on weight control and glucose metabolism. Two structurally distinct TSPO drug ligands, PK 11195 and FGIN-1-27, improved the intracellular dynamics of 3T3-L1 adipocytes, such as the production and release of adipokines, glucose uptake, and adipogenesis. TSPO knockdown in either differentiated adipocytes or preadipocytes impaired these functions. Findings from 3T3-L1 cells were related to human primary cells, where TSPO expression was tightly associated with the metabolic state of primary adipocytes and the differentiation of primary preadipocytes. These results suggest that TSPO expression is essential to safeguard healthy adipocyte functions, and that TSPO activation in adipocytes improves their metabolic status in regulating glucose homeostasis. Adipocyte TSPO may serve as a pharmacologic target for the treatment of obesity and diabetes.

  13. Metformin induces glucose uptake in human preadipocyte-derived adipocytes from various fat depots.

    Science.gov (United States)

    Fischer, M; Timper, K; Radimerski, T; Dembinski, K; Frey, D M; Zulewski, H; Keller, U; Müller, B; Christ-Crain, M; Grisouard, J

    2010-04-01

    To evaluate the effect of metformin on basal and insulin-induced glucose uptake in subcutaneous and visceral preadipocyte-derived adipocytes from obese and non-obese patients, preadipocytes were obtained from subcutaneous and visceral fat depots during abdominal surgery. Differentiation efficiency was evaluated by measurement of intracellular triglyceride accumulation. Preadipocyte-derived adipocytes were treated with metformin (1 mM) for 24 h with or without the addition of insulin (100 nM) for 20 min and glucose uptake was measured. In cells from each donor, intracellular triglyceride accumulation was more abundant in subcutaneous preadipocyte-derived adipocytes than in visceral preadipocyte-derived adipocytes (p < 0.001). Insulin stimulated glucose uptake in subcutaneous preadipocyte-derived adipocytes from both non-obese and obese patients (p < 0.001 vs. basal). In visceral preadipocyte-derived adipocytes, insulin did not increase basal glucose uptake. In subcutaneous preadipocyte-derived adipocytes from non-obese and obese patients, metformin alone increased glucose uptake to 2.7 +/- 0.2 (p < 0.001) and 2.1 +/- 0.1 fold (p < 0.001) respectively. Metformin increased glucose uptake in visceral preadipocyte-derived adipocytes from non-obese (1.7 +/- 0.1 fold vs. basal, p < 0.001) and obese (2.0 +/- 0.2 fold vs. basal, p < 0.001) patients. Combined treatment with metformin and insulin increased glucose uptake in subcutaneous preadipocyte-derived adipocytes from both non-obese and obese patients (p < 0.001 vs. insulin alone). In preadipocyte-derived adipocytes glucose uptake is induced by metformin independent of the fat depot origin of the preadipocytes (subcutaneous or visceral) and the obesity state of the patients (non-obese or obese). In adipocytes, metformin seems to induce glucose uptake independent of insulin suggesting an alternative mechanism of action of this drug.

  14. 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.

  15. TSH effects on thermogenesis in rat brown adipocytes.

    Science.gov (United States)

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

    2015-03-15

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

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

    Directory of Open Access Journals (Sweden)

    Rajan eSingh

    2014-10-01

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

  17. NAMPT-mediated NAD+ biosynthesis in adipocytes regulates adipose tissue function and multi-organ insulin sensitivity in mice

    Science.gov (United States)

    Stromsdorfer, Kelly L.; Yamaguchi, Shintaro; Yoon, Myeong Jin; Moseley, Anna C.; Franczyk, Michael P.; Kelly, Shannon C.; Qi, Nathan; Imai, Shin-ichiro; Yoshino, Jun

    2016-01-01

    SUMMARY Obesity is associated with adipose tissue dysfunction and multi-organ insulin resistance. However, the mechanisms of such obesity-associated systemic metabolic complications are not clear. Here, we characterized mice with adipocyte-specific deletion of nicotinamide phosphoribosyltransferase (NAMPT), a rate-limiting NAD+ biosynthetic enzyme known to decrease in adipose tissue of obese and aged rodents and people. We found that adipocyte-specific Nampt knockout mice had severe insulin resistance in adipose tissue, liver, and skeletal muscle, and adipose tissue dysfunction, manifested by increased plasma free fatty acids concentrations and decreased plasma concentrations of a major insulin-sensitizing adipokine, adiponectin. Loss of Nampt increased phosphorylation of CDK5 and PPARγ (serine-273) and decreased gene expression of obesity-linked phosphorylated PPARγ targets in adipose tissue. Remarkably, these deleterious alterations were normalized by administering rosiglitazone or a key NAD+ intermediate, nicotinamide mononucleotide (NMN). Collectively, our results provide important mechanistic and therapeutic insights into obesity-associated systemic metabolic derangements, particularly multi-organ insulin resistance. PMID:27498863

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    Long-term exposure to peroxisome proliferator-activated receptor γ (PPARγ) agonists such as rosiglitazone induces browning of rodent and human adipocytes; however, the transcriptional mechanisms governing this phenotypic switch in adipocytes are largely unknown. Here we show that rosiglitazone-in...

  19. 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.

  20. Characterization of adipocytes derived from fibro/adipogenic progenitors resident in human skeletal muscle

    Science.gov (United States)

    Arrighi, N; Moratal, C; Clément, N; Giorgetti-Peraldi, S; Peraldi, P; Loubat, A; Kurzenne, J-Y; Dani, C; Chopard, A; Dechesne, C A

    2015-01-01

    A population of fibro/adipogenic but non-myogenic progenitors located between skeletal muscle fibers was recently discovered. The aim of this study was to determine the extent to which these progenitors differentiate into fully functional adipocytes. The characterization of muscle progenitor-derived adipocytes is a central issue in understanding muscle homeostasis. They are considered as being the cellular origin of intermuscular adipose tissue that develops in several pathophysiological situations. Here fibro/adipogenic progenitors were isolated from a panel of 15 human muscle biopsies on the basis of the specific cell-surface immunophenotype CD15+/PDGFRα+CD56−. This allowed investigations of their differentiation into adipocytes and the cellular functions of terminally differentiated adipocytes. Adipogenic differentiation was found to be regulated by the same effectors as those regulating differentiation of progenitors derived from white subcutaneous adipose tissue. Similarly, basic adipocyte functions, such as triglyceride synthesis and lipolysis occurred at levels similar to those observed with subcutaneous adipose tissue progenitor-derived adipocytes. However, muscle progenitor-derived adipocytes were found to be insensitive to insulin-induced glucose uptake, in association with the impairment of phosphorylation of key insulin-signaling effectors. Our findings indicate that muscle adipogenic progenitors give rise to bona fide white adipocytes that have the unexpected feature of being insulin-resistant. PMID:25906156

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

    Science.gov (United States)

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

    2015-09-01

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

  2. 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...

  3. Presence of the cannabinoid receptors, CB1 and CB2, in human omental and subcutaneous adipocytes.

    Science.gov (United States)

    Roche, Régis; Hoareau, Laurence; Bes-Houtmann, Sandrine; Gonthier, Marie-Paule; Laborde, Christine; Baron, Jean-François; Haffaf, Yacine; Cesari, Maya; Festy, Franck

    2006-08-01

    To investigate the expression of the endocannabinoid 1 and 2 receptors by human adipocyte cells of omental and subcutaneous fat tissue, as well as to determine whether these receptors are functional. The expression of CB1 and CB2 receptors on human adipocytes was analyzed by western blotting, immunohistology and immunocytology. We also investigated intracytoplasmic cyclic AMP level modulation following CB1 and CB2 receptor stimulation by an enzymatic immuno assay. All mature adipocytes, from visceral (epiploon) and subcutaneous fat tissue, express CB1 and CB2 on their plasma membranes. We also demonstrate in this study that adipocyte precursors (pre-adipocytes) express CB1 and CB2 on their plasma membranes and that both receptors are functional. Activation of CB1 increases intracytoplasmic cyclic AMP whilst CB2 activation leads to a cyclic AMP decrease. Here we demonstrate, for the first time, that adipocytes of human adipose tissue (mature adipocytes and pre-adipocytes) express functional plasma membrane CB1 and CB2 receptors. Their physiological role on the adipose tissue is not known. However, their major involvement in the physiology of other tissues leads us to suppose that they could play a significant role in the homeostasis of the energy balance and/or in the regulation of adipose tissue inflammation.

  4. Raptor/mTORC1 loss in adipocytes causes progressive lipodystrophy and fatty liver disease

    Directory of Open Access Journals (Sweden)

    Peter L. Lee

    2016-06-01

    Conclusions: mTORC1 activity in mature adipocytes is essential for maintaining normal adipose tissue growth and its selective loss in mature adipocytes leads to a progressive lipodystrophy disorder and systemic metabolic disease that shares many of the hallmarks of human congenital generalized lipodystrophy.

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

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

    2015-05-01

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

  7. Nutritional and hormonal control of lipolysis in isolated gilthead seabream (Sparus aurata) adipocytes.

    Science.gov (United States)

    Albalat, A; Gómez-Requeni, P; Rojas, P; Médale, F; Kaushik, S; Vianen, G J; Van den Thillart, G; Gutiérrez, J; Pérez-Sánchez, J; Navarro, I

    2005-07-01

    We examined the effects of diet composition and fasting on lipolysis of freshly isolated adipocytes from gilthead seabream (Sparus aurata). We also analyzed the effects of insulin, glucagon, and growth hormone (GH) in adipocytes isolated from fish fed with different diets. Basal lipolysis, measured as glycerol release, increased proportionally with cell concentration and time of incubation, which validates the suitability of these cell preparations for the study of hormonal regulation of this metabolic process. Gilthead seabream were fed two different diets, FM (100% of fish meal) and PP (100% of plant protein supplied by plant sources) for 6 wk. After this period, each diet group was divided into two groups: fed and fasted (for 11 days). Lipolysis was significantly higher in adipocytes from PP-fed fish than in adipocytes from FM-fed fish. Fasting provoked a significant increase in the lipolytic rate, about threefold in isolated adipocytes regardless of nutritional history. Hormone effects were similar in the different groups: glucagon increased the lipolytic rate, whereas insulin had almost no effect. GH was clearly lipolytic, although the relative increase in glycerol over control was lower in isolated adipocytes from fasted fish compared with fed fish. Together, we demonstrate for the first time that lipolysis, measured in isolated seabream adipocytes, is affected by the nutritional state of the fish. Furthermore, our data suggest that glucagon and especially GH play a major role in the control of adipocyte lipolysis.

  8. 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

    GPR39, a constitutively active 7TM receptor important for glucose-induced insulin secretion and maturation of pancreatic ß-cell function, is up-regulated in adipose tissue on abstinence from food and chemically induced diabetes. In the present study, we investigated the effect of GPR39 deficiency...

  9. 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.

  10. Effects of the Monoclonal Antibody against Porcine 40 kDa Adipocyte-specific Plasma Membrane Protein on Adipocytes and Carcass Composition

    Institute of Scientific and Technical Information of China (English)

    Shizheng GAO; Changrong GE; Xi ZHANG; Yonggang LIU

    2007-01-01

    The effects of the mouse monoclonal antibody against 40 kDa adipocyte-specific plasma membrane protein on porcine adipocytes and carcass composition were investigated in vitro and in vivo.Results revealed that the in vitro complement-mediated cytotoxicity of this monoclonal antibody can lead to adipocyte lysis, remarkable reduction of adipocyte lipid accumulation (P<0.01), and significant decrease of well-differentiated fat cells (P<0.01). Treatment of adipocytes with this antibody alone in vitro did not induce cell lysis, but could lead to noticeable reduction of well-differentiated cells and lipid accumulation (P<0.05) at the pre-adipocyte stage. In vivo, pigs injected with 0.5 mg/kg or 1.0 mg/kg of antibody showed smaller adipocyte sizes (P<0.01) and reduced lipid accumulation of adipocytes (P<0.01). Our results also indicated that pigs intraperitoneally or subcutaneously immunized with 0.5 mg/kg of monoclonal antibody at 15 kg or 1.0 mg/kg antibody at 60 kg had a higher lean meat percentage (P<0.05), larger loin eye area (P<0.05), lower fat meat percentage (P<0.05), less backfat thickness (P<0.05) and smaller leaf fat weight (P<0.05) than the control pigs, but other carcass traits such as caul fat weight, heart weight, liver weight, spleen weight,kidney weight, lung weight, and dressing percentage were not significantly affected. These results suggested that this monoclonal antibody could be applied to restrain excessive fat deposition in porcine production.

  11. 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.

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

    Science.gov (United States)

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

    2014-01-01

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

  13. 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

    AMP sensitivity. Suppression of cAMP-dependent protein kinase activity in Rb(-/-)MEFs blocked the brown adipocyte-like gene expression pattern without affecting differentiation per se. Immunohistochemical studies revealed that pRB is present in the nuclei of white but not brown adipocyte precursor cells......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...

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

    Science.gov (United States)

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

    2015-10-01

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

  15. Different anti-adipogenic effects of bio-compounds on primary visceral pre-adipocytes and adipocytes

    Science.gov (United States)

    Colitti, Monica; Stefanon, Bruno

    2016-01-01

    Several natural compounds exhibit strong capacity for decreasing triglyceride accumulation, enhancing lipolysis and inducing apoptosis. The present study reports the anti-adipogenic effects of Silybum marianum (SL), Citrus aurantium (CA), Taraxacum officinale (TO), resveratrol (RE), Curcuma longa (CU), caffeine (CF), oleuropein (OL) and docosahexaenoic acid (DHA) in reducing differentiation and increasing lipolysis and apoptosis. Analyses were performed on human primary visceral pre-adipocytes after 10 (P10) and 20 (P20) days of treatment during differentiation and on mature adipocytes after 7 days of treatment (A7). The percentage of apoptosis induced by TO extract in P10 and P20 cells was significantly higher than that induced by all other compounds and in CTRL cells. Triglyceride accumulation was significantly lower in cells treated with DHA, CF, RE in comparison to cells treated with OL and in CTRL cells. Treatments with CF, DHA and OL significantly incremented lipolysis in P20 cells in comparison to other compounds and in CTRL cells. On the contrary, the treatment of A7 cells with OL, CA and TO compounds significantly increased cell lipolysis. The addition of CF in differentiating P20 pre-adipocytes significantly increased the expression of genes involved in inhibition of adipogenesis, such as GATA2, GATA3, WNT1, WNT3A, SFRP5, and DLK1. Genes involved in promoting adipogenesis such as CCND1, CEBPB and SREBF1 were significantly down-regulated by the treatment. The screening of bioactive compounds for anti-adipogenic effects showed that in differentiating cells TO extract was the most effective in inducing apoptosis and CF and DHA extracts were more efficient in inhibition of differentiation and in induction of cell lipolysis. PMID:27540349

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-25

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

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

    Directory of Open Access Journals (Sweden)

    Didier F Pisani

    2011-11-01

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

  18. Research on genesis of adipocytic metaplasia in uterine fibroids.

    Science.gov (United States)

    Sośnik, Henryk; Jeleń, Michał; Kosiński, Mariusz; Sośnik, Katarzyna

    2015-12-01

    The genesis of lipoleiomyoma has not been explained yet. Immunohistochemical examinations were performed on 17 lipoleiomyomas in women aged 43-82 (mean age: 51 ±9 years). Four types of myomas were distinguished: 1) pure leiomyoma, 2) fibroleiomyoma, 3) hyalinizing leiomyoma, 4) strongly hyalinized myoma, along with three degrees of progression of adipocytic metaplasia: 1) up to 25% of lipocytes, 2) up to 50% of lipocytes, and 3) over 50% of lipocytes in the analyzed sample, along with three degrees of progression of adipocytic metaplasia: 1) up to 25% of lipocytes, 2) up to 50% of lipocytes, and 3) over 50% of lipocytes in the analyzed sample. A positive correlation was found between the age of women and rate of development of metaplasia (r = 0.51, p = 0.035) as well as with activity of the estrogen receptor in the primary tumor (r = 0.53, p = 0.03). New mucous perivascular tissue was reported among 11.8% of patients and on this basis lipocytes were formed. The appearance of subendothelial granular cells of large blood vessels with a positive reaction for smooth muscle actin (SMA) and CD68 was reported in 17.7%. Results of immunohistochemical research seem to confirm that lipocytes de novo come from the primal pluripotent cells of the tumor stroma and not from the fatty degeneration of myocytes.

  19. Annexin A3 as a negative regulator of adipocyte differentiation.

    Science.gov (United States)

    Watanabe, Takenori; Ito, Yoshimasa; Sato, Asuka; Hosono, Takashi; Niimi, Shingo; Ariga, Toyohiko; Seki, Taiichiro

    2012-10-01

    Annexin A3 is a protein belonging to the annexin family, and it is mainly present in cellular membranes as a phospholipid-binding protein that binds via the calcium ion. However, its physiological function remains to be clarified. We examined the expression of annexin A3 in mouse tissues and found for the first time that annexin A3 mRNA and its protein were expressed more strongly in adipose tissues than in other tissues. In adipose tissues, annexin A3-expressing cells were present in the stromal vascular fraction, and precisely identical to Pref-1-positive preadipocytes, Pref-1 being an epidermal growth factor repeat-containing transmembrane protein that inhibits adipogenesis. In 3T3-L1 cells, used as a model of adipogenesis, annexin A3 was down-regulated at an early phase of adipocyte differentiation, and this pattern paralleled that of Pref-1. Suppression of annexin A3 in these cells with siRNA caused elevation of the PPARγ2 mRNA level and lipid droplet accumulation. In conclusion, our data suggest that annexin A3 is a negative regulator of adipocyte differentiation.

  20. Adipocyte glucose transport regulation by eicosanoid precursors and inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    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/sup 0/C, gassed with 95% O/sub 2/-5% CO/sub 2/ in KRB buffer with 3% bovine serum albumin and with or without eicosanoid modifiers; a stimulator (10/sup -5/ M norepinephrine, N), or inhibitors (167 ..mu..l of antiserum to prostaglandin E (AntiE) per 1600 ..mu..l 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 /sup 3/H-2-deoxy glucose, /sup 14/C-inulin, and liquid scintillation counter.

  1. Differentiation of Pre-Adipocytes in Modelled Microgravity

    Science.gov (United States)

    Coinu, R.; Postiglione, I.; Meloni, M. A.; Galleri, G.; Pippia, P.; Palumbo, G.

    2008-06-01

    It has been demonstrated that microgravity affects biological and biochemical functions of cells including: morphology, cytoskeleton and embryogenesis [1]; proliferation, reduction of DNA, protein synthesis and glucose transport [2]; signalling, reduction of EGF-dependant c-fos and c-jun expression [3]; gene expression, reduction of IL2 expression and release by activated T-cells [4]. Moreover it has be found that peroxisome proliferators activated receptor γ (PPARγ2), which is known to be important for adipocyte differentiation, adipsin, leptin, and glucose transporter-4, are highly expressed in response to modelled microgravity [5]. These findings prompted us to investigate the effects of microgravity on cellular differentiation rate using a well characterized model. Such model consists in murine pre-adipocyte cells (3T3-L1) properly stimulated with insulin, dexamethazone and isobuthylmethyl-xantine (DMI protocol). The adipogenic program is completed within a short time. The entire process requires coordinated and temporarily beated molecular events. Early events. Growth arrest at confluence; Clonal expansion (this process involves synchronous entry of cells into S phase of the cell cycle, leading to one or two rounds of mitosis); Early expression of C/EBPβ and C/EBPδ. Late events. Expression of PPARγ and C/EBPα Assumption of rounded morphology and accumulation of lipid droplets.

  2. 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.

  3. Resveratrol metabolites modify adipokine expression and secretion in 3T3-L1 pre-adipocytes and mature adipocytes.

    Directory of Open Access Journals (Sweden)

    Itziar Eseberri

    Full Text Available OBJECTIVE: Due to the low bioavailability of resveratrol, determining whether its metabolites exert any beneficial effect is an interesting issue. METHODS: 3T3-L1 maturing pre-adipocytes were treated during differentiation with 25 µM of resveratrol or with its metabolites and 3T3-L1 mature adipocytes were treated for 24 hours with 10 µM resveratrol or its metabolites. The gene expression of adiponectin, leptin, visfatin and apelin was assessed by Real Time RT-PCR and their concentration in the incubation medium was quantified by ELISA. RESULTS: Resveratrol reduced mRNA levels of leptin and increased those of adiponectin. It induced the same changes in leptin secretion. Trans-resveratrol-3-O-glucuronide and trans-resveratrol-4'-O-glucuronide increased apelin and visfatin mRNA levels. Trans-resveratrol-3-O-sulfate reduced leptin mRNA levels and increased those of apelin and visfatin. CONCLUSIONS: The present study shows for the first time that resveratrol metabolites have a regulatory effect on adipokine expression and secretion. Since resveratrol has been reported to reduce body-fat accumulation and to improve insulin sensitivity, and considering that these effects are mediated in part by changes in the analyzed adipokines, it may be proposed that resveratrol metabolites play a part in these beneficial effects of resveratrol.

  4. Adipocytes from New Zealand Obese Mice Exhibit Aberrant Proinflammatory Reactivity to the Stress Signal Heat Shock Protein 60

    Directory of Open Access Journals (Sweden)

    Tina Märker

    2014-01-01

    Full Text Available Adipocytes release immune mediators that contribute to diabetes-associated inflammatory processes. As the stress protein heat shock protein 60 (Hsp60 induces proinflammatory adipocyte activities, we hypothesized that adipocytes of diabetes-predisposed mice exhibit an increased proinflammatory reactivity to Hsp60. Preadipocytes and mature adipocytes from nonobese diabetic (NOD, New Zealand obese (NZO, and C57BL/6J mice were analyzed for Hsp60 binding, Hsp60-activated signaling pathways, and Hsp60-induced release of the chemokine CXCL-1 (KC, interleukin 6 (IL-6, and macrophage chemoattractant protein-1 (MCP-1. Hsp60 showed specific binding to (pre-adipocytes of NOD, NZO, and C57BL/6J mice. Hsp60 binding involved conserved binding structure(s and Hsp60 epitopes and was strongest to NZO mouse-derived mature adipocytes. Hsp60 exposure induced KC, IL-6, and MCP-1 release from (pre-adipocytes of all mouse strains with a pronounced increase of IL-6 release from NZO mouse-derived adipocytes. Compared to NOD and C57BL/6J mouse derived cells, Hsp60-induced formation of IL-6, KC, and MCP-1 from NZO mouse-derived (pre-adipocytes strongly depended on NFκB-activation. Increased Hsp60 binding and Hsp60-induced IL-6 release by mature adipocytes of NZO mice suggest that enhanced adipocyte reactivity to the stress signal Hsp60 contributes to inflammatory processes underlying diabetes associated with obesity and insulin resistance.

  5. Isoorientin reverts TNF-α-induced insulin resistance in adipocytes activating the insulin signaling pathway.

    Science.gov (United States)

    Alonso-Castro, Angel Josabad; Zapata-Bustos, Rocio; Gómez-Espinoza, Guadalupe; Salazar-Olivo, Luis A

    2012-11-01

    Isoorientin (ISO) is a plant C-glycosylflavonoid with purported antidiabetic effects but unexplored mechanisms of action. To gain insight into its antidiabetic mechanisms, we assayed nontoxic ISO concentrations on the 2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2-deoxy-d-glucose (2-NBDG) uptake by murine 3T3-F442A and human sc adipocytes. In insulin-sensitive adipocytes, ISO stimulated the 2-NBDG uptake by 210% (murine) and 67% (human), compared with insulin treatment. Notably, ISO also induced 2-NBDG uptake in murine (139%) and human (60%) adipocytes made resistant to insulin by treatment with TNF-α, compared with the incorporation induced in these cells by rosiglitazone. ISO induction of glucose uptake in adipocytes was abolished by inhibitors of the insulin signaling pathway. These inhibitors also blocked the proper phosphorylation of insulin signaling pathway components induced by ISO in both insulin-sensitive and insulin-resistant adipocytes. Additionally, ISO stimulated the transcription of genes encoding components of insulin signaling pathway in murine insulin-sensitive and insulin-resistant adipocytes. In summary, we show here that ISO exerts its antidiabetic effects by activating the insulin signaling pathway in adipocytes, reverts the insulin resistance caused in these cells by TNF-α by stimulating the proper phosphorylation of proteins in this signaling pathway, and induces the expression of genes encoding these proteins.

  6. Curcumin promotes cholesterol efflux from adipocytes related to PPARgamma-LXRalpha-ABCA1 passway.

    Science.gov (United States)

    Dong, Shao-zhuang; Zhao, Shui-ping; Wu, Zhi-hong; Yang, Jun; Xie, Xiang-zhu; Yu, Bi-lian; Nie, Sai

    2011-12-01

    Curcumin affects the functions of adipocytes. But it is not known whether curcumin has some effect on the cholesterol efflux process of adipocytes. Rabbit subcutaneous adipocytes were incubated with 5, 10 and 20 μg/ml curcumin for 24 h. The cholesterol efflux onto apoAI was assessed, and the peroxisome proliferators-activated receptor (PPAR) γ, liver X receptor (LXR) α and ATP-binding cassette transporter A1 (ABCA1) mRNA expression in adipocytes were quantified by reverse-transcription polymerase chain reaction (RT-PCR). Curcumin increased the cholesterol efflux from adipocytes in dose-dependent manner. The increased expression of PPARγ, LXRα and ABCA1 caused by curcumin were parallel. When the adipocytes were pre-treated by GW9662, the increased expression of PPARγ induced by curcumin was partially prevented, subsequent to the down-regulation of LXRα and ABCA1. Curcumin can affect the cholesterol efflux from adipocytes by regulating the PPARγ-LXR-ABCA1 passway.

  7. Adipose progenitor cells reside among the mature adipocytes: morphological research using an organotypic culture system.

    Science.gov (United States)

    Anayama, Hisashi; Fukuda, Ryo; Yamate, Jyoji

    2015-11-01

    The precise localization and biological characteristics of the adipose progenitor cells are still a focus of debate. In this study, the localization of the adipose progenitor cells was determined using an organotypic culture system of adipose tissue slices. The tissue slices of subcutaneous white adipose tissue from rats were placed on a porous membrane and cultured at the interface between air and the culture medium for up to 5 days with or without adipogenic stimulation. The structure of adipose tissue components was sufficiently preserved during the culture and, following adipogenic stimulation with insulin, dexamethasone, and 3-isobutyl-1-methylxanthine, numerous multilocular adipocytes appeared in the interstitium among the mature adipocytes. Histomorphological 3-D observation using confocal laser microscopy revealed the presence of small mesenchymal cells containing little or no fat residing in the perivascular region and on the mature adipocytes and differentiation from the pre-existing mesenchymal cells to multilocular adipocytes. Immunohistochemistry demonstrated that these cells were initially present within the fibronectin-positive extracellular matrix (ECM). The adipose differentiation of the mesenchymal cells was confirmed by the enhanced expression of C/EBP-β suggesting adipose differentiation and the concurrent advent of CD105-expressing mesenchymal cells within the interstitium of the mature adipocytes. Based on the above, the mesenchymal cells embedded in the ECM around the mature adipocytes were confirmed to be responsible for adipogenesis because the transition of the mesenchymal cells to the stem state contributed to the increase in the number of adipocytes in rat adipose tissue.

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

    Science.gov (United States)

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

    2013-01-01

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

  9. Reduced DPP4 activity improves insulin signaling in primary human adipocytes.

    Science.gov (United States)

    Röhrborn, Diana; Brückner, Julia; Sell, Henrike; Eckel, Jürgen

    2016-03-11

    DPP4 is a ubiquitously expressed cell surface protease which is also released to the circulation as soluble DPP4 (sDPP4). Recently, we identified DPP4 as a novel adipokine oversecreted in obesity and thus potentially linking obesity to the metabolic syndrome. Furthermore, sDPP4 impairs insulin signaling in an autocrine and paracrine fashion in different cell types. However, it is still unknown which functional role DPP4 might play in adipocytes. Therefore, primary human adipocytes were treated with a specific DPP4 siRNA. Adipocyte differentiation was not affected by DPP4 silencing. Interestingly, DPP4 reduction improved insulin responsiveness of adipocytes at the level of insulin receptor, proteinkinase B (Akt) and Akt substrate of 160 kDa. To investigate whether the observed effects could be attributed to the enzymatic activity of DPP4, human adipocytes were treated with the DPP4 inhibitors sitagliptin and saxagliptin. Our data show that insulin-stimulated activation of Akt is augmented by DPP4 inhibitor treatment. Based on our previous observation that sDPP4 induces insulin resistance in adipocytes, and that adipose DPP4 levels are higher in obese insulin-resistant patients, we now suggest that the abundance of DPP4 might be a regulator of adipocyte insulin signaling.

  10. Co-cultivation of human aortic smooth muscle cells with epicardial adipocytes affects their proliferation rate.

    Science.gov (United States)

    Ždychová, J; Čejková, S; Králová Lesná, I; Králová, A; Malušková, J; Janoušek, L; Kazdová, L

    2014-01-01

    The abnormal proliferation of vascular smooth muscle cells (VSMC) is thought to play a role in the pathogenesis of atherosclerosis. Adipocytes produce several bioactive paracrine substances that can affect the growth and migration of VSMCs. Our study focuses on the direct effect of the bioactive substances in conditioned media (CM) that was obtained by incubation with primary adipocyte-derived cell lines, including cell lines derived from both preadipocytes and from more mature cells, on the proliferation rate of human aortic smooth muscle cells (HAoSMCs). We used a Luminex assay to measure the adipokine content of the CM and showed that there was a higher concentration of monocyte chemoattractant protein-1 in renal preadipocyte-CM compared with the HAoSMC control (p<0.5). The addition of both renal preadipocyte- and epicardial adipocyte- CM resulted in the elevated production of vascular endothelial growth factor compared with the control HASoSMC CM (p<0.001). The adiponectin content in renal adipocyte-CM was increased compared to all the remaining adipocyte-CM (p<0.01). Moreover, the results showed a higher proliferation rate of HAoSMCs after co-culture with epicardial adipocyte-CM compared to the HAoSMC control (p<0.05). These results suggest that bioactive substances produced by adipocytes have a stimulatory effect on the proliferation of VSMCs.

  11. 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

  12. Preparation of isolated bovine adipocytes: validation of use for studies characterizing insulin sensitivity and binding.

    Science.gov (United States)

    Vasilatos, R; Etherton, T D; Wangsness, P J

    1983-05-01

    The present study was undertaken to develop techniques to isolate bovine adipocytes, to compare their rates of glucose metabolism and insulin sensitivity with adipocytes in adipose tissue, and to determine if isolated bovine adipocytes specifically bind insulin. Cell size and diameter distributions were the same for adipocytes fixed with OsO4 after isolation with collagenase and adipocytes liberated from OsO4-fixed adipose tissue slices. On a per cell basis, lipogenic rates were greater for isolated adipocytes compared with intact adipose tissue. Similar differences were found for glucose oxidation. In short term incubations, glucose oxidation and lipid synthesis were not stimulated by insulin (0-100 ng/ml) in either isolated adipocytes or tissue. Specific binding of [125I]iodoinsulin at 30 C was low (0.8%) in the first group of six beef cattle sampled, but increased with increasing cell concentration. Insulin degradation after 90 min was less than 5%. The specificity of [125I]iodoinsulin binding was studied in a second group of six animals. There was no specific binding of insulin in this group. In summary, bovine adipocytes can be isolated which are metabolically active and provide a valid system for studying hormone binding and action. In the present study, glucose metabolism in bovine adipocytes was not stimulated by insulin in vitro. This insensitivity to insulin was associated with a negligible capacity for insulin binding. These findings suggest that the lack of insulin sensitivity in bovine adipose tissue may be due to an inability to specifically bind insulin. This may be related to the unique metabolism of ruminant adipose tissue, which is less dependent upon glucose for fatty acid synthesis than is adipose tissue from nonruminant species.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-09-01

    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. Aquaporin-10 represents an alternative pathway for glycerol efflux from human adipocytes.

    Directory of Open Access Journals (Sweden)

    Umberto Laforenza

    Full Text Available BACKGROUND: Glycerol outflow from adipocytes has been considered for a decade to be mediated by aquaporin-7, an aquaglyceroporin highly expressed in the adipose tissue. Its involvement in glycerol metabolism has been widely studied also in humans. Recent studies in different aquaporin-7 KO mice models pose two different questions 1 the exact localization of aquaporin-7 in human white adipose tissue; 2 the existence of other aquaglyceroporins that work with aquaporin-7 to guarantee glycerol efflux and thus a normal adiposity in humans. To this purpose we investigated the expression, the localization and the functioning of aquaglyceroporin-10 in subcutaneous white adipose tissue, in isolated and cultured differentiated adipocytes. METHODOLOGY/PRINCIPAL FINDINGS: Aquaporin-7 and -10 were expressed in the white adipose tissue both at mRNA and at protein level. Immunofluorescence revealed aquaporin-7 and -10 labelling in the human adipose tissue both to the plasma membrane and to a thin rim of cytoplasm of adipocytes. Aquaporin-7, but not aquaporin-10, colocalized with the endothelial marker CD34. Human cultured differentiated adipocytes showed an aquaporin-7 and -10 labelling mainly in the cytoplasm and in the lipid droplets with insulin reinforcing the lipid droplets staining and isoproterenol inducing its translocation to the plasma membrane compartment. Water and glycerol permeability measurements using adipocytes and adipose membrane vesicles confirmed the presence of functioning aquaglyceroporins. Aquaporin-10 silencing in human differentiated adipocytes resulted in a 50% decrease of glycerol and osmotic water permeability. CONCLUSIONS/SIGNIFICANCE: The results indicate that aquaporin-7, differently from mice, is present in both adipocyte and capillary plasma membranes of human adipose tissue. Aquaporin-10, on the contrary, is expressed exclusively in the adipocytes. The expression of two aquaglyceroporins in human adipose tissue is

  15. Hypochlorous acid via peroxynitrite activates protein kinase Cθ and insulin resistance in adipocytes

    OpenAIRE

    Zhou, Jun; Wang, Qilong; Ding, Ye; Zou, Ming-hui

    2015-01-01

    We recently reported that genetic deletion of myeloperoxidase (MPO) alleviates obesity-related insulin resistance in mice in vivo. How MPO impairs insulin sensitivity in adipocytes is poorly characterized. As hypochlorous acid (HOCl) is a principal oxidant product generated by MPO, we evaluated the effects of HOCl on insulin signaling in adipocytes differentiated from 3T3-L1 cells. Exposure of 3T3-L1 adipocytes to exogenous HOCl (200 μmol/l) attenuated insulin-stimulated 2-deoxyglucose uptake...

  16. MicroRNA networks regulate development of brown adipocytes.

    Science.gov (United States)

    Trajkovski, Mirko; Lodish, Harvey

    2013-09-01

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

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    A diet enriched in PUFAs, in particular of the n-3 family, decreases adipose tissue mass and suppresses development of obesity in rodents. Although several nuclear hormone receptors are identified as PUFA targets, the precise molecular mechanisms underlying the effects of PUFAs still remain...... to be elucidated. Here we review research aimed at elucidating molecular mechanisms governing the effects of PUFAs on the differentiation and function of white fat cells. This review focuses on dietary PUFAs as signaling molecules, with special emphasis on agonistic and antagonistic effects on transcription...... 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...

  18. 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.

  19. Do regional differences in adipocyte biology provide new pathophysiological insights?

    Science.gov (United States)

    Lafontan, Max; Berlan, Michel

    2003-06-01

    Obesity is an increasing health problem in many countries. Striking differences exist in the magnitude of the impact of different obesities on comorbidities. Individuals with peripheral obesity ('pears') possess fat distributed subcutaneously in gluteofemoral areas and the lower part of the abdomen, and are at little risk of metabolic complications. Conversely, individuals with upper-body obesity ('apples') accumulate fat in subcutaneous and visceral deposits and are more prone to metabolic and cardiovascular problems, particularly when visceral fat deposits are abundant. In this article, whether the different risk factors for obesity of 'apples' and 'pears' are largely related to the heterogeneity of function and responsiveness of the adipocytes from visceral and subcutaneous deposits is questioned. Possible pharmacological approaches to the treatment of obesity and related diseases are also considered.

  20. Natriuretic peptides: a new lipolytic pathway in human adipocytes.

    Science.gov (United States)

    Sengenès, C; Berlan, M; De Glisezinski, I; Lafontan, M; Galitzky, J

    2000-07-01

    Atrial natriuretic peptide (ANP) receptors have been described on rodent adipocytes and expression of their mRNA is found in human adipose tissue. However, no biological effects associated with the stimulation of these receptors have been reported in this tissue. A putative lipolytic effect of natriuretic peptides was investigated in human adipose tissue. On isolated fat cells, ANP and brain natriuretic peptide (BNP) stimulated lipolysis as much as isoproterenol, a nonselective beta-adrenergic receptor agonist, whereas C-type natriuretic peptide (CNP) had the lowest lipolytic effect. In situ microdialysis experiments confirmed the potent lipolytic effect of ANP in abdominal s.c. adipose tissue of healthy subjects. A high level of ANP binding sites was identified in human adipocytes. The potency order defined in lipolysis (ANP > BNP > CNP) and the ANP-induced cGMP production sustained the presence of type A natriuretic peptide receptor in human fat cells. Activation or inhibition of cGMP-inhibited phosphodiesterase (PDE-3B) (using insulin and OPC 3911, respectively) did not modify ANP-induced lipolysis whereas the isoproterenol effect was decreased or increased. Moreover, inhibition of adenylyl cyclase activity (using a mixture of alpha(2)-adrenergic and adenosine A1 agonists receptors) did not change ANP- but suppressed isoproterenol-induced lipolysis. The noninvolvement of the PDE-3B was finally confirmed by measuring its activity under ANP stimulation. Thus, we demonstrate that natriuretic peptides are a new pathway controlling human adipose tissue lipolysis operating via a cGMP-dependent pathway that does not involve PDE-3B inhibition and cAMP production.

  1. Impact of 3-Amino-1,2,4-Triazole (3-AT)-Derived Increase in Hydrogen Peroxide Levels on Inflammation and Metabolism in Human Differentiated Adipocytes

    Science.gov (United States)

    Ruiz-Ojeda, Francisco Javier; Gomez-Llorente, Carolina; Aguilera, Concepción María; Gil, Angel; Rupérez, Azahara Iris

    2016-01-01

    Obesity is characterized by an excessive accumulation of fat in adipose tissue, which is associated with oxidative stress and chronic inflammation. Excessive H2O2 levels are degraded by catalase (CAT), the activity of which is decreased in obesity. We investigated the effects of inhibition of catalase activity on metabolism and inflammation by incubating human differentiated adipocytes with 10 mM 3-amino-1,2,4-triazole (3-AT) for 24 h. As expected, the treatment decreased CAT activity and increased intracellular H2O2 levels significantly. Glutathione peroxidase (GPX) activity was also reduced, and the gene expression levels of the antioxidant enzymes GPX4 and peroxiredoxins (1, 3 and 5) were inhibited. Interestingly, this occurred along with lower mRNA levels of the transcription factors nuclear factor (erythroid 2-like 2) and forkhead box O, which are involved in redox homeostasis. However, superoxide dismutase activity and expression were increased. Moreover, 3-AT led to nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and increased tumor necrosis alpha and interleukin 6 protein and gene expression levels, while lowering peroxisome proliferator-activated receptor gamma (PPARγ) mRNA and protein levels. These alterations were accompanied by an altered glucose and lipid metabolism. Indeed, adipocytes treated with 3-AT showed reduced basal glucose uptake, reduced glucose transporter type 4 gene and protein expression, reduced lipolysis, reduced AMP-activated protein kinase activation and reduced gene expression of lipases. Our results indicate that increased H2O2 levels caused by 3-AT treatment impair the antioxidant defense system, lower PPARγ expression and initiate inflammation, thus affecting glucose and lipid metabolism in human differentiated adipocytes. PMID:27023799

  2. Effects of early- to mid-gestational undernutrition with or without protein supplementation on offspring growth, carcass characteristics, and adipocyte size in beef cattle.

    Science.gov (United States)

    Long, N M; Tousley, C B; Underwood, K R; Paisley, S I; Means, W J; Hess, B W; Du, M; Ford, S P

    2012-01-01

    Angus × Gelbvieh cows with 2 to 3 previous pregnancies were used to evaluate effects of maternal nutrient restriction on offspring adipose tissue morphology at standard production endpoints. At 45 d after AI to a single sire, pregnancy was confirmed and cows randomly allotted into groups and fed a control (Con, 100% of NRC recommendations), nutrient-restricted (NR, 70% of Con diet), or nutrient-restricted + protein-supplemented (NRP, 70% of Con + essential AA supply to the small intestine equal to Con) diet. At d 185 of gestation, cows were commingled and received the Con diet thereafter. Bull calves were castrated at 2 mo of age. Calves were weaned at 210 d, backgrounded for 28 d, and then placed in the feedlot for 195 d. Steers and heifers were slaughtered at an average 12th-rib fat thickness of 7.6 mm. Adipose tissue from selected depots was collected for adipocyte size analysis. There was no significant difference in BW or BCS between Con, NRP, and NR cows at d 45 of gestation, which averaged 489.7 ± 17.7 kg and 5.35 ± 0.13, respectively. At d 185 of gestation, Con and NRP groups had similar BW (566.1 ± 14.8 and 550.2 ± 14.8 kg) and BCS (6.34 ± 0.27 and 5.59 ± 0.27), but NR cows exhibited reduced (P BCS (4.81 ± 0.27). Among offspring (steers and heifers) at slaughter, there were no significant differences in BW or organ weights among treatment groups. Yield grade was reduced (P < 0.05) and semitendinosus weight/HCW tended (P = 0.09) to be reduced in NR offspring compared with Con and NRP offspring. Average adipocyte diameter was increased (P < 0.05) in subcutaneous, mesenteric, and omental adipose tissue and tended (P = 0.09) to increase in perirenal adipose tissue in NR compared with Con offspring with NRP offspring adipocyte diameter being either intermediate or similar to Con calves. The adipocyte size alterations observed in NR offspring were confirmed by DNA concentration of the adipose tissue depots. There also was an increased mRNA expression (P

  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

    trained rats. Furthermore, the abundance of the mRNAs for these proteins and glucose transport was measured. Rats were swim-trained for 10 wk, and adipocytes were isolated from epididymal fat pads. The amount of GLUT-4/adipocyte volume unit was significantly higher in trained animals compared with both......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...... age- and cell size-matched animals. The amount of GLUT-4 mRNA was also increased by training and it decreased with increasing age. Furthermore, young age as well as training was accompanied by relatively low GLUT-4 protein/mRNA and relatively high overall GLUT-4 efficiency (recruitability and...

  4. Suppressive Role of PPARγ-Regulated Endothelial Nitric Oxide Synthase in Adipocyte Lipolysis.

    Directory of Open Access Journals (Sweden)

    Yoko Yamada

    Full Text Available Metabolic syndrome causes insulin resistance and is associated with risk factor clustering, thereby increasing the risk of atherosclerosis. Recently, endothelial nitric oxide synthase deficient (eNOS-/- mice have been reported to show metabolic disorders. Interestingly, eNOS has also been reported to be expressed in non-endothelial cells including adipocytes, but the functions of eNOS in adipocytes remain unclear.The eNOS expression was induced with adipocyte differentiation and inhibition of eNOS/NO enhanced lipolysis in vitro and in vivo. Furthermore, the administration of a high fat diet (HFD was able to induce non-alcoholic steatohepatitis (NASH in eNOS-/- mice but not in wild type mice. A PPARγ antagonist increased eNOS expression in adipocytes and suppressed HFD-induced fatty liver changes.eNOS-/- mice induce NASH development, and these findings provide new insights into the therapeutic approach for fatty liver disease and related disorders.

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

    Directory of Open Access Journals (Sweden)

    Maude Giroud

    2016-08-01

    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.

  6. 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...

  7. Adipocyte deficiency of angiotensinogen prevents obesity-induced hypertension in male mice.

    Science.gov (United States)

    Yiannikouris, Frederique; Gupte, Manisha; Putnam, Kelly; Thatcher, Sean; Charnigo, Richard; Rateri, Debra L; Daugherty, Alan; Cassis, Lisa A

    2012-12-01

    Previous studies demonstrated that diet-induced obesity increased plasma angiotensin II concentrations and elevated systolic blood pressures in male mice. Adipocytes express angiotensinogen and secrete angiotensin peptides. We hypothesize that adipocyte-derived angiotensin II mediates obesity-induced increases in systolic blood pressure in male high fat-fed C57BL/6 mice. Systolic blood pressure was measured by radiotelemetry during week 16 of low-fat or high-fat feeding in Agt(fl/fl) and adipocyte angiotensinogen-deficient mice (Agt(aP2)). Adipocyte angiotensinogen deficiency had no effect on diet-induced obesity. Basal 24-hour systolic blood pressure was not different in low fat-fed Agt(fl/fl) compared with Agt(aP2) mice (124 ± 3 versus 128 ± 3 mm Hg, respectively). In Agt(fl/fl) mice, high-fat feeding significantly increased systolic blood pressure (24 hours; 134 ± 2 mm Hg; Pobesity hypertension.

  8. Bone marrow–derived circulating progenitor cells fail to transdifferentiate into adipocytes in adult adipose tissues in mice

    Science.gov (United States)

    Koh, Young Jun; Kang, Shinae; Lee, Hyuek Jong; Choi, Tae-Saeng; Lee, Ho Sub; Cho, Chung-Hyun; Koh, Gou Young

    2007-01-01

    Little is known about whether bone marrow–derived circulating progenitor cells (BMDCPCs) can transdifferentiate into adipocytes in adipose tissues or play a role in expanding adipocyte number during adipose tissue growth. Using a mouse bone marrow transplantation model, we addressed whether BMDCPCs can transdifferentiate into adipocytes under standard conditions as well as in the settings of diet-induced obesity, rosiglitazone treatment, and exposure to G-CSF. We also addressed the possibility of transdifferentiation to adipocytes in a murine parabiosis model. In each of these settings, our findings indicated that BMDCPCs did not transdifferentiate into either unilocular or multilocular adipocytes in adipose tissues. Most BMDCPCs became resident and phagocytic macrophages in adipose tissues — which resembled transdifferentiated multilocular adipocytes by appearance, but displayed cell surface markers characteristic for macrophages — in the absence of adipocyte marker expression. When exposed to adipogenic medium in vitro, bone marrow cells differentiated into multilocular, but not unilocular, adipocytes, but transdifferentiation was not observed in vivo, even in the contexts of adipose tissue regrowth or dermal wound healing. Our results suggest that BMDCPCs do not transdifferentiate into adipocytes in vivo and play little, if any, role in expanding the number of adipocytes during the growth of adipose tissues. PMID:18060029

  9. Impact of metabolic regulators on the expression of the obesity associated genes FTO and NAMPT in human preadipocytes and adipocytes.

    Directory of Open Access Journals (Sweden)

    Daniela Friebe

    Full Text Available BACKGROUND: FTO and NAMPT/PBEF/visfatin are thought to play a role in obesity but their transcriptional regulation in adipocytes is not fully understood. In this study, we evaluated the transcriptional regulation of FTO and NAMPT in preadipocytes and adipocytes by metabolic regulators. METHODOLOGY AND PRINCIPAL FINDINGS: We assessed FTO mRNA expression during human adipocyte differentiation of Simpson-Golabi-Behmel syndrome (SGBS cells and primary subcutaneous preadipocytes in vitro and evaluated the effect of the metabolic regulators glucose, insulin, dexamethasone, IGF-1 and isoproterenol on FTO and NAMPT mRNA expression in SGBS preadipocytes and adipocytes. FTO mRNA levels were not significantly modulated during adipocyte differentiation. Also, metabolic regulators had no impact on FTO expression in preadipocytes or adipocytes. In SGBS preadipocytes NAMPT expression was more than 3fold induced by dexamethasone and isoproterenol and 1.6fold by dexamethasone in adipocytes. Complete glucose restriction caused an increase in NAMPT mRNA expression by more than 5fold and 1.4fold in SGBS preadipocytes and adipocytes, respectively. CONCLUSION: FTO mRNA expression is not significantly affected by differentiation or metabolic regulators in human adipocytes. The stimulation of NAMPT expression by dexamethasone, isoproterenol and complete glucose restriction may indicate a regulation of NAMPT by metabolic stress, which was more pronounced in preadipocytes compared to mature adipocytes.

  10. Impact of Metabolic Regulators on the Expression of the Obesity Associated Genes FTO and NAMPT in Human Preadipocytes and Adipocytes

    Science.gov (United States)

    Schönberg, Maria; Bernhard, Falk; Büttner, Petra; Landgraf, Kathrin; Kiess, Wieland; Körner, Antje

    2011-01-01

    Background FTO and NAMPT/PBEF/visfatin are thought to play a role in obesity but their transcriptional regulation in adipocytes is not fully understood. In this study, we evaluated the transcriptional regulation of FTO and NAMPT in preadipocytes and adipocytes by metabolic regulators. Methodology and Principal Findings We assessed FTO mRNA expression during human adipocyte differentiation of Simpson-Golabi-Behmel syndrome (SGBS) cells and primary subcutaneous preadipocytes in vitro and evaluated the effect of the metabolic regulators glucose, insulin, dexamethasone, IGF-1 and isoproterenol on FTO and NAMPT mRNA expression in SGBS preadipocytes and adipocytes. FTO mRNA levels were not significantly modulated during adipocyte differentiation. Also, metabolic regulators had no impact on FTO expression in preadipocytes or adipocytes. In SGBS preadipocytes NAMPT expression was more than 3fold induced by dexamethasone and isoproterenol and 1.6fold by dexamethasone in adipocytes. Complete glucose restriction caused an increase in NAMPT mRNA expression by more than 5fold and 1.4fold in SGBS preadipocytes and adipocytes, respectively. Conclusion FTO mRNA expression is not significantly affected by differentiation or metabolic regulators in human adipocytes. The stimulation of NAMPT expression by dexamethasone, isoproterenol and complete glucose restriction may indicate a regulation of NAMPT by metabolic stress, which was more pronounced in preadipocytes compared to mature adipocytes. PMID:21687707

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  12. 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

  13. St. John's Wort Has Metabolically Favorable Effects on Adipocytes In Vivo

    OpenAIRE

    Scott Fuller; Richard, Allison J.; Ribnicky, David M; Robbie Beyl; Randall Mynatt; Stephens, Jacqueline M.

    2014-01-01

    In addition to serving as a storage site for reserve energy, adipocytes play a critical role in whole-body insulin sensitivity and glucose metabolism. St. John's Wort (SJW) is a botanical supplement widely used as an over-the-counter treatment of depression and a variety of other conditions associated with anxiety and nerve pain. Previous studies in our laboratory demonstrated that SJW inhibits insulin-stimulated glucose uptake and adipocyte differentiation in cultured murine and mature human...

  14. Control of lipid metabolism by adipocyte FGFR1-mediated adipohepatic communication during hepatic stress

    Directory of Open Access Journals (Sweden)

    Yang Chaofeng

    2012-10-01

    Full Text Available Abstract Background Endocrine FGF19 and FGF21 exert their effects on metabolic homeostasis through fibroblast growth factor receptor (FGFR and co-factor betaKlotho (KLB. Ileal FGF19 regulates bile acid metabolism through specifically FGFR4-KLB in hepatocytes where FGFR1 is not significant. Both FGF19 and FGF21 activate FGFR1-KLB whose function predominates in adipocytes. Recent studies using administration of FGF19 and FGF21 and genetic ablation of KLB or adipocyte FGFR1 indicate that FGFR1-KLB mediates the response of adipocytes to both FGF21 and FGF19. Here we show that adipose FGFR1 regulates lipid metabolism through direct effect on adipose tissue and indirect effects on liver under starvation conditions that cause hepatic stress. Methods We employed adipocyte-specific ablations of FGFR1 and FGFR2 genes in mice, and analyzed metabolic consequences in adipose tissue, liver and systemic parameters under normal, fasting and starvation conditions. Results Under normal conditions, the ablation of adipose FGFR1 had little effect on adipocytes, but caused shifts in expression of hepatic genes involved in lipid metabolism. Starvation conditions precipitated a concurrent elevation of serum triglycerides and non-esterified fatty acids, and increased hepatic steatosis and adipose lipolysis in the FGFR1-deficient mice. Little effect on glucose or ketone bodies due to the FGFR1 deficiency was observed. Conclusions Our results suggest an adipocyte-hepatocyte communication network mediated by adipocyte FGFR1 that concurrently dampens hepatic lipogenesis and adipocyte lipolysis. We propose that this serves overall to mete out and extend lipid reserves for neural fuels (glucose and ketone bodies, while at the same time governing extent of hepatosteatosis during metabolic extremes and other conditions causing hepatic stress.

  15. The Action of D-Dopachrome Tautomerase as an Adipokine in Adipocyte Lipid Metabolism

    OpenAIRE

    2012-01-01

    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-rela...

  16. 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...

  17. 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.

  18. Loss of Oncostatin M Signaling in Adipocytes Induces Insulin Resistance and Adipose Tissue Inflammation in Vivo.

    Science.gov (United States)

    Elks, Carrie M; Zhao, Peng; Grant, Ryan W; Hang, Hardy; Bailey, Jennifer L; Burk, David H; McNulty, Margaret A; Mynatt, Randall L; Stephens, Jacqueline M

    2016-08-12

    Oncostatin M (OSM) is a multifunctional gp130 cytokine. Although OSM is produced in adipose tissue, it is not produced by adipocytes. OSM expression is significantly induced in adipose tissue from obese mice and humans. The OSM-specific receptor, OSM receptor β (OSMR), is expressed in adipocytes, but its function remains largely unknown. To better understand the effects of OSM in adipose tissue, we knocked down Osmr expression in adipocytes in vitro using siRNA. In vivo, we generated a mouse line lacking Osmr in adiponectin-expressing cells (OSMR(FKO) mice). The effects of OSM on gene expression were also assessed in vitro and in vivo OSM exerts proinflammatory effects on cultured adipocytes that are partially rescued by Osmr knockdown. Osm expression is significantly increased in adipose tissue T cells of high fat-fed mice. In addition, adipocyte Osmr expression is increased following high fat feeding. OSMR(FKO) mice exhibit increased insulin resistance and adipose tissue inflammation and have increased lean mass, femoral length, and bone volume. Also, OSMR(FKO) mice exhibit increased expression of Osm, the T cell markers Cd4 and Cd8, and the macrophage markers F4/80 and Cd11c Interestingly, the same proinflammatory genes induced by OSM in adipocytes are induced in the adipose tissue of the OSMR(FKO) mouse, suggesting that increased expression of proinflammatory genes in adipose tissue arises both from adipocytes and other cell types. These findings suggest that adipocyte OSMR signaling is involved in the regulation of adipose tissue homeostasis and that, in obesity, OSMR ablation may exacerbate insulin resistance by promoting adipose tissue inflammation.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

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

    2016-10-01

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

  1. Human adipocytes from the subcutaneous superficial layer have greater adipogenic potential and lower PPAR-γ DNA methylation levels than deep layer adipocytes.

    Science.gov (United States)

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

    2016-08-01

    Human subcutaneous fat tissue consists of two layers, superficial adipose tissue (SAT) and deep adipose tissue (DAT). Some recent reports suggest that a disproportionate accumulation of DAT is related to obesity-associated metabolic complications. However, the differences in adipocyte function between SAT and DAT are unclear. To clarify the differences in human adipocyte characteristics between SAT and DAT, human ceiling culture-derived proliferative adipocytes (ccdPAs) were primary cultured from SAT and DAT of three lean female patients. Differences in adipogenic differentiation potential and sensitivity to exogenous adipogenic factors were examined. Epigenetic modification of the CpG island DNA methylation levels of genes related to adipogenesis was measured. In histological analyses, the mean adipocyte size in SAT was significantly larger than that in DAT (8,741 ± 416 vs. 7,732 ± 213 μm(2), P < 0.05). Primary cultured adipocytes from SAT showed significantly greater adipogenesis than did those of DAT. Sensitivity to partial adipogenic stimulation was significantly different between ccdPAs of SAT and DAT. Peroxisome proliferator-activated receptor-γ (PPAR-γ) protein expression and leptin protein secretion from ccdPAs were significantly higher in SAT than DAT. DNA methylation levels of PPAR-γ were significantly lower in ccdPAs of SAT than DAT. Adipocyte size was larger in SAT than DAT in vivo. This is consistent with the findings of an in vitro study that, compared with ccdPAs in DAT, ccdPAs in SAT have higher adipogenic potential and lower DNA methylation levels of PPAR-γ.

  2. Pluripotent stem cells derived from mouse and human white mature adipocytes.

    Science.gov (United States)

    Jumabay, Medet; Abdmaulen, Raushan; Ly, Albert; Cubberly, Mark R; Shahmirian, Laurine J; Heydarkhan-Hagvall, Sepideh; Dumesic, Daniel A; Yao, Yucheng; Boström, Kristina I

    2014-02-01

    White mature adipocytes give rise to so-called dedifferentiated fat (DFAT) cells that spontaneously undergo multilineage differentiation. In this study, we defined stem cell characteristics of DFAT cells as they are generated from adipocytes and the relationship between these characteristics and lineage differentiation. Both mouse and human DFAT cells, prepared from adipose tissue and lipoaspirate, respectively, showed evidence of pluripotency, with a maximum 5-7 days after adipocyte isolation. The DFAT cells spontaneously formed clusters in culture, which transiently expressed multiple stem cell markers, including stage-specific embryonic antigens, and Sca-1 (mouse) and CD105 (human), as determined by real-time polymerase chain reaction, fluorescence-activated cell sorting, and immunostaining. As the stem cell markers decreased, markers characteristic of the three germ layers and specific lineage differentiation, such as α-fetoprotein (endoderm, hepatic), Neurofilament-66 (ectoderm, neurogenic), and Troponin I (mesoderm, cardiomyogenic), increased. However, no teratoma formation was detected after injection in immunodeficient mice. A novel modification of the adipocyte isolation aimed at ensuring the initial purity of the adipocytes and avoiding ceiling culture allowed isolation of DFAT cells with pluripotent characteristics. Thus, the adipocyte-derived DFAT cells represent a plastic stem cell population that is highly responsive to changes in culture conditions and may benefit cell-based therapies.

  3. Octanoate and decanoate induce apoptosis in 3T3-L1 adipocytes.

    Science.gov (United States)

    Yang, Jeong-Yeh; Rayalam, Srujana; Della-Fera, Mary Anne; Ambati, Suresh; Baile, Clifton A

    2009-10-01

    The effect of octanoate and decanoate, respectively, eight- and 10-carbon medium-chain fatty acids (MCFAs), on apoptotic signaling in 3T3-L1 adipocytes was investigated. 3T3-L1 adipocytes were treated with various concentrations of octanoate or decanoate. Cell viability, apoptosis, and expression of apoptosis-related proteins were investigated. Results indicated that both octanoate and decanoate decreased viability, increased apoptosis, and increased reactive oxygen species production. Immunoblotting analysis showed an increase in the levels of cytoplasmic cytochrome c and cleaved poly(ADP-ribose) polymerase by octanoate and decanoate. Concomitantly, we observed that pro-caspase-3 was decreased, resulting in the induced accumulation of the cleaved form of caspase-3 by both octanoate and decanoate. In addition, both octanoate and decanoate increased the expression of pro-apoptotic Bax with an accompanied decrease of anti-apoptotic Bcl-2. These results show that octanoate and decanoate mediate adipocyte apoptosis via a caspase-dependent mitochondrial pathway in 3T3-L1 adipocytes. MCFAs thus decrease adipocyte number by initiating the apoptotic process in 3T3-L1 adipocytes.

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

    Science.gov (United States)

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

    2016-12-01

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

  5. Effect of Cross-Sex Hormonal Replacement on Antioxidant Enzymes in Rat Retroperitoneal Fat Adipocytes

    Science.gov (United States)

    Velázquez Espejel, Rodrigo; Cabrera-Orefice, Alfredo; Uribe-Carvajal, Salvador; Pavón, Natalia

    2016-01-01

    We report the effect of cross-sex hormonal replacement on antioxidant enzymes from rat retroperitoneal fat adipocytes. Eight rats of each gender were assigned to each of the following groups: control groups were intact female or male (F and M, resp.). Experimental groups were ovariectomized F (OvxF), castrated M (CasM), OvxF plus testosterone (OvxF + T), and CasM plus estradiol (CasM + E2) groups. After sacrifice, retroperitoneal fat was dissected and processed for histology. Adipocytes were isolated and the following enzymatic activities were determined: Cu-Zn superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GR). Also, glutathione (GSH) and lipid peroxidation (LPO) were measured. In OvxF, retroperitoneal fat increased and adipocytes were enlarged, while in CasM rats a decrease in retroperitoneal fat and small adipocytes are observed. The cross-sex hormonal replacement in F rats was associated with larger adipocytes and a further decreased activity of Cu-Zn SOD, CAT, GPx, GST, GR, and GSH, in addition to an increase in LPO. CasM + E2 exhibited the opposite effects showing further activation antioxidant enzymes and decreases in LPO. In conclusion, E2 deficiency favors an increase in retroperitoneal fat and large adipocytes. Cross-sex hormonal replacement in F rats aggravates the condition by inhibiting antioxidant enzymes. PMID:27630756

  6. Effect of Glycine on Adipocyte Hypertrophy in a Metabolic Syndrome Rat Model.

    Science.gov (United States)

    López, Yazmín Reyes; Pérez-Torres, Israel; Zúñiga-Muñoz, Alejandra; Lans, Verónica Guarner; Díaz-Díaz, Eulises; Castro, Elizabeth Soria; Espejel, Rodrigo Velázquez

    2016-01-01

    Glycine (Gly) lowers hypercholesterolemia, hypertriglyceridemia and hypertension but its role in preventing adipocyte hypertrophy and modulating enzymatic activity of adipocytes has not been studied. Here we evaluate the effect of 1% Gly in the diet on adipocyte hypertrophy and the modulation of lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) in a metabolic syndrome (MS) rat model with intra-abdominal obesity. 32 Wistar rats were divided into 3 groups: control (C), MS, MS plus Gly (MS+Gly), and MS+Gly plus strychnine (MS+Gly+S). MS was induced by administering 30% sucrose in the drinking water for 16 weeks. In the MS+Gly and MS+Gly+S groups, the sucrose solution plus 1% Gly and 1 % Gly plus strychnine 10 μM were given during the last 4 weeks of the sucrose treatment. After 16 weeks of treatment, rats were sacrificed and the adipose tissue dissected. Gly in MS rats decreased body weight, intra-abdominal adipose tissue, adipocyte hypertrophy, blood pressure, triglycerides, insulin, HOMA-IR index, leptin, total fatty acids, non-esterified fatty acids and LPL activity. It increased fatty acids of the phospholipids, perilipin A expression and it decreased HSL expression, without changing LPL expression. The Gly receptor subunit-β was identified in adipocytes. In conclusion, Gly treatment regulates the activity of enzymes involved in the lipid metabolism of the adipocytes through the Gly receptor and it decreases the effects of the high sucrose diet.

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

    Science.gov (United States)

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

    2008-02-15

    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 gamma (PPARgamma) 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 PPARgamma 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 PPARgamma-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.

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

    Science.gov (United States)

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

    2016-01-01

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

  9. 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.

  10. Aldose reductases influence prostaglandin F2α levels and adipocyte differentiation in male mouse and human species.

    Science.gov (United States)

    Pastel, Emilie; Pointud, Jean-Christophe; Loubeau, Gaëlle; Dani, Christian; Slim, Karem; Martin, Gwenaëlle; Volat, Fanny; Sahut-Barnola, Isabelle; Val, Pierre; Martinez, Antoine; Lefrançois-Martinez, Anne-Marie

    2015-05-01

    Aldose reductases (AKR1B) are widely expressed oxidoreductases whose physiological function remains elusive. Some isoforms are genuine prostaglandin F2α (PGF2α) synthases, suggesting they might influence adipose homeostasis because PGF2α inhibits adipogenesis. This was shown by Akr1b7 gene ablation in the mouse, which resulted in increased adiposity related to a lower PGF2α content in fat. Yet humans have no ortholog gene for Akr1b7, so the role of aldose reductases in human adipose homeostasis remains to be explored. We analyzed expression of genes encoding human and mouse aldose reductase isoforms in adipose tissues and differentiating adipocytes to assess conserved mechanisms regulating PGF2α synthesis and adipogenesis. The Akr1b3 gene encoded the most abundant isoform in mouse adipose tissue, whereas Akr1b7 encoded the only isoform enriched in the stromal vascular fraction. Most mouse aldose reductase gene expression peaked in early adipogenesis of 3T3-L1 cells and diminished with differentiation. In contrast with its mouse ortholog Akr1b3, AKR1B1 expression increased throughout differentiation of human multipotent adipose-derived stem cells, paralleling PGF2α release, whereas PGF2α receptor (FP) levels collapsed in early differentiation. Pharmacological inhibition of aldose reductase using Statil altered PGF2α production and enhanced human multipotent adipose-derived stem adipocyte differentiation. As expected, the adipogenic effects of Statil were counteracted by an FP agonist (cloprostenol). Thus, in both species aldose reductase-dependent PGF2α production could be important in early differentiation to restrict adipogenesis. PGF2α antiadipogenic signaling could then be toned down through the FP receptor or aldose reductases down-regulation in human and mouse cells, respectively. Our data suggest that aldose reductase inhibitors could have obesogenic potential.

  11. 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

  12. 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.

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

    Science.gov (United States)

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

    2012-09-30

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

  14. An Model to Probe the Regulation of Adipocyte Differentiation under Hyperglycemia

    Directory of Open Access Journals (Sweden)

    Kusampudi Shilpa

    2013-06-01

    Full Text Available BackgroundThe aim of this study was an in vitro investigation of the effect of high glucose concentration on adipogenesis, as prolonged hyperglycemia alters adipocyte differentiation.Methods3T3-L1 preadipocytes differentiated in the presence of varying concentrations of glucose (25, 45, 65, 85, and 105 mM were assessed for adipogenesis using AdipoRed (Lonza assay. Cell viability and proliferation were measured using MTT reduction and [3H] thymidine incorporation assay. The extent of glucose uptake and glycogen synthesis were measured using radiolabelled 2-deoxy-D-[1-3H] glucose and [14C]-UDP-glucose. The gene level expression was evaluated using reverse transcription-polymerase chain reaction and protein expression was studied using Western blot analysis.ResultsGlucose at 105 mM concentration was observed to inhibit adipogenesis through inhibition of CCAAT-enhancer-binding proteins, sterol regulatory element-binding protein, peroxisome proliferator-activated receptor and adiponectin. High concentration of glucose induced stress by increasing levels of toll-like receptor 4, nuclear factor κB and tumor necrosis factor α thereby generating activated preadipocytes. These cells entered the state of hyperplasia through inhibition of p27 and proliferation was found to increase through activation of protein kinase B via phosphoinositide 3 kinase dependent pathway. This condition inhibited insulin signaling through decrease in insulin receptor β. Although the glucose transporter 4 (GLUT4 protein remained unaltered with the glycogen synthesis inhibited, the cells were found to exhibit an increase in glucose uptake via GLUT1.ConclusionAdipogenesis in the presence of 105 mM glucose leads to an uncontrolled proliferation of activated preadipocytes providing an insight towards understanding obesity.

  15. Adipocytes do not significantly contribute to plasma angiotensinogen

    Directory of Open Access Journals (Sweden)

    Masahiro Koizumi

    2016-10-01

    Full Text Available Recently, it has been reported that 25% of plasma angiotensinogen (Agt is derived from fat. Meanwhile, liver-specific Agt knockout (KO mice have markedly low plasma Agt, which may be due to reduced fat mass. To study the contribution of the fat to plasma Agt, we tested whether increasing fat mass can elevate plasma Agt and blood pressure in liver-Agt KO mice. Epididymal fat mass in liver-Agt KO mice fed a high-fat diet (HFD was 4.1-fold larger than that in liver-Agt KO mice on a normal-fat diet (NFD. The liver-Agt KO mice on NFD were hypotensive with low levels of plasma Agt (on average, 0.11 vs 2.38 μg/ml. HFD slightly increased plasma Agt (0.17 μg/ml without increase in blood pressure. To further increase fat mass, liver-Agt KO mice were fed HFD and simultaneously supplemented with low-dose angiotensin II and compared with control mice. Fat mass was comparable between the two groups. However, liver-Agt KO mice had uniformly low plasma Agt (0.09 vs 2.07 μg/ml and systolic blood pressure (78±12 vs 111±6 mm Hg. In conclusion, adipocyte-derived Agt has essentially no contribution to the plasma concentration and no impact on blood pressure compared to liver-derived Agt.

  16. The effect of lesions of the sympathoadrenal system on training induced adaptations in adipocytes and pancreatic islets in rats

    DEFF Research Database (Denmark)

    Stallknecht, B; Roesdahl, M; Vinten, J

    1996-01-01

    in sham adrenodemedullated rats (P swim trained for 10 weeks or remained sedentary. Insulin stimulated 3-O-[14C]methylglucose transport......Physical training increases insulin stimulated glucose uptake in adipocytes and decreases insulin secretion from pancreatic islets. The mechanism behind these adaptations is not known. Because in acute exercise adrenergic activity influences both adipocytes and pancreatic islets, the sympathetic...... was measured in adipocytes from epididymal fat pads, and insulin secretion and glucose metabolism were measured in glucose stimulated pancreatic islets. Training increased insulin stimulated glucose transport in adipocytes (P

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

    Directory of Open Access Journals (Sweden)

    Joram D Mul

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

  18. Subcutaneous adipocytes promote melanoma cell growth by activating the Akt signaling pathway: role of palmitic acid.

    Science.gov (United States)

    Kwan, Hiu Yee; Fu, Xiuqiong; Liu, Bin; Chao, Xiaojuan; Chan, Chi Leung; Cao, Huihui; Su, Tao; Tse, Anfernee Kai Wing; Fong, Wang Fun; Yu, Zhi-Ling

    2014-10-31

    Tumorigenesis involves constant communication between tumor cells and neighboring normal cells such as adipocytes. The canonical function of adipocytes is to store triglyceride and release fatty acids for other tissues. This study was aimed to find out if adipocytes promoted melanoma cell growth and to investigate the underlying mechanism. Here we isolated adipocytes from inguinal adipose tissue in mice and co-cultured with melanoma cells. We found that the co-cultured melanoma had higher lipid accumulation compared with mono-cultured melanoma. In addition, fluorescently labeled fatty acid BODIPY® FLC16 signal was detected in melanoma co-cultured with the adipocytes that had been loaded with the fluorescent dye, suggesting that the adipocytes provide fatty acids to melanoma cells. Compared with mono-cultured melanoma, co-cultured melanoma cells had a higher proliferation and phospho-Akt (Ser-473 and Thr-450) expression. Overexpression of Akt mutants in melanoma cells reduced the co-culture-enhanced proliferation. A lipidomic study showed that the co-cultured melanoma had an elevated palmitic acid level. Interestingly, we found that palmitic acid stimulated melanoma cell proliferation, changed the cell cycle distribution, and increased phospho-Akt (Ser-473 and Thr-450) and PI3K but not phospho-PTEN (phosphophosphatase and tensin homolog) expressions. More importantly, the palmitic acid-stimulated proliferation was further enhanced in the Akt-overexpressed melanoma cells and was reduced by LY294002 or knockdown of endogenous Akt or overexpression of Akt mutants. We also found that palmitic acid-pretreated B16F10 cells were grown to a significantly larger tumor in mice compared with control cells. Taken together, we suggest that adipocytes may serve as an exogenous source of palmitic acid that promotes melanoma cell growth by activating Akt.

  19. Berberine increases expression of GATA-2 and GATA-3 during inhibition of adipocyte differentiation.

    Science.gov (United States)

    Hu, Y; Davies, G E

    2009-09-01

    It is known that a number of transcription factors are key regulators in the complex process of adipocyte differentiation including peroxisome proliferator activated receptor gamma (PPARgamma) and the CCAAT enhancer binding protein alpha (C/EBPalpha). Studies have demonstrated that in pre-adipocyte 3T3-L1 cells constitutive expression of the DNA binding proteins GATA-2 and GATA-3 results in protein/protein interactions with C/EBPalpha resulting in down regulation of PPARgamma and subsequent suppressed adipocyte differentiation with cells trapped at the pre-adipocyte stage. Thus it appears that GATA-2 and GATA-3 are of critical importance in regulating adipocyte differentiation through molecular interactions with PPARgamma and C/EBPalpha. Recent reports suggest that berberine, an isoquinoline derivative alkaloid isolated from many medicinal herbs prevents differentiation of 3T3-L1 cells via a down regulation of PPARgamma and C/EBPalpha expression. The aim of this study was to determine the effect of berberine on GATA-2 and 3 gene and protein expression levels during differentiation of 3T3-L1 cells. MTT (Methylthiazolyldiphenyl-tetrazolium bromide) was used to detect the cytotoxic effects of berberine on the viability of 3T3-L1 cells during proliferation and differentiation. Differentiation of 3T3-L1 cells was monitored by Oil Red O staining and RT-PCR of PPARgamma and C/EBPalpha and the expression of GATA-2 and 3 was determined by RT-PCR and Western Blot. Results show that following treatment with 8microM berberine the mRNA and protein expression levels of GATA-2 and 3 were elevated and accompanied by inhibited adipocyte differentiation. These results may lead to the use of berberine to target the induction of specific genes such as GATA-2 and GATA-3 which affect adipocyte differentiation.

  20. Comparison of Markers and Functional Attributes of Human Adipose-Derived Stem Cells and Dedifferentiated Adipocyte Cells from Subcutaneous Fat of an Obese Diabetic Donor.

    Science.gov (United States)

    Watson, James E; Patel, Niketa A; Carter, Gay; Moor, Andrea; Patel, Rekha; Ghansah, Tomar; Mathur, Abhishek; Murr, Michel M; Bickford, Paula; Gould, Lisa J; Cooper, Denise R

    2014-03-01

    Objective: Adipose tissue is a robust source of adipose-derived stem cells (ADSCs) that may be able to provide secreted factors that promote the ability of wounded tissue to heal. However, adipocytes also have the potential to dedifferentiate in culture to cells with stem cell-like properties that may improve their behavior and functionality for certain applications. Approach: ADSCs are adult mesenchymal stem cells that are cultured from the stromal vascular fraction of adipose tissue. However, adipocytes are capable of dedifferentiating into cells with stem cell properties. In this case study, we compare ADSC and dedifferentiated fat (DFAT) cells from the same patient and fat depot for mesenchymal cell markers, embryonic stem cell markers, ability to differentiate to adipocytes and osteoblasts, senescence and telomerase levels, and ability of conditioned media (CM) to stimulate migration of human dermal fibroblasts (HDFs). Innovation and Conclusions: ADSCs and DFAT cells displayed identical levels of CD90, CD44, CD105, and were CD34- and CD45-negative. They also expressed similar levels of Oct4, BMI1, KLF4, and SALL4. DFAT cells, however, showed higher efficiency in adipogenic and osteogenic capacity. Telomerase levels of DFAT cells were double those of ADSCs, and senescence declined in DFAT cells. CM from both cell types altered the migration of fibroblasts. Despite reports of ADSCs from a number of human depots, there have been no comparisons of the ability of dedifferentiated DFAT cells from the same donor and depot to differentiate or modulate migration of HDFs. Since ADSCs were from an obese diabetic donor, reprogramming of DFAT cells may help improve a patient's cells for regenerative medicine applications.

  1. 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.

  2. Augmented expression and secretion of adipose-derived pigment epithelium-derived factor does not alter local angiogenesis or contribute to the development of systemic metabolic derangements.

    Science.gov (United States)

    Lakeland, Thomas V; Borg, Melissa L; Matzaris, Maria; Abdelkader, Amany; Evans, Roger G; Watt, Matthew J

    2014-06-15

    Impaired coupling of adipose tissue expansion and vascularization is proposed to lead to adipocyte hypoxia and inflammation, which in turn contributes to systemic metabolic derangements. Pigment epithelium-derived factor (PEDF) is a powerful antiangiogenic factor that is secreted by adipocytes, elevated in obesity, and implicated in the development of insulin resistance. We explored the angiogenic and metabolic role of adipose-derived PEDF through in vivo studies of mice with overexpression of PEDF in adipocytes (PEDF-aP2). PEDF expression in white adipocytes and PEDF secretion from adipose tissue was increased in transgenic mice, but circulating levels of PEDF were not increased. Overexpression of PEDF did not alter vascularization, the partial pressure of O2, cellular hypoxia, or gene expression of inflammatory markers in adipose tissue. Energy expenditure and metabolic substrate utilization, body mass, and adiposity were not altered in PEDF-aP2 mice. Whole body glycemic control was normal as assessed by glucose and insulin tolerance tests, and adipocyte-specific glucose uptake was unaffected by PEDF overexpression. Adipocyte lipolysis was increased in PEDF-aP2 mice and associated with increased adipose triglyceride lipase and decreased perilipin 1 expression. Experiments conducted in mice rendered obese by high-fat feeding showed no differences between PEDF-aP2 and wild-type mice for body mass, adiposity, whole body energy expenditure, glucose tolerance, or adipose tissue oxygenation. Together, these data indicate that adipocyte-generated PEDF enhances lipolysis but question the role of PEDF as a major antiangiogenic or proinflammatory mediator in adipose tissue in vivo.

  3. 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.

  4. Perilipin1 promotes unilocular lipid droplet formation through the activation of Fsp27 in adipocytes.

    Science.gov (United States)

    Sun, Zhiqi; Gong, Jingyi; Wu, Han; Xu, Wenyi; Wu, Lizhen; Xu, Dijin; Gao, Jinlan; Wu, Jia-Wei; Yang, Hongyuan; Yang, Maojun; Li, Peng

    2013-01-01

    Mature white adipocytes contain a characteristic unilocular lipid droplet. However, the molecular mechanisms underlying unilocular lipid droplet formation are poorly understood. We previously showed that Fsp27, an adipocyte-specific lipid droplet-associated protein, promotes lipid droplet growth by initiating lipid exchange and transfer. Here, we identify Perilipin1 (Plin1), another adipocyte-specific lipid droplet-associated protein, as an Fsp27 activator. Plin1 interacts with the CIDE-N domain of Fsp27 and markedly increases Fsp27-mediated lipid exchange, lipid transfer and lipid droplet growth. Functional cooperation between Plin1 and Fsp27 is required for efficient lipid droplet growth in adipocytes, as depletion of either protein impairs lipid droplet growth. The CIDE-N domain of Fsp27 forms homodimers and disruption of CIDE-N homodimerization abolishes Fsp27-mediated lipid exchange and transfer. Interestingly, Plin1 can restore the activity of CIDE-N homodimerization-defective mutants of Fsp27. We thus uncover a novel mechanism underlying lipid droplet growth and unilocular lipid droplet formation that involves the cooperative action of Fsp27 and Plin1 in adipocytes.

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

    Science.gov (United States)

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

    2005-10-01

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

  6. Accelerated fat cell aging links oxidative stress and insulin resistance in adipocytes

    Indian Academy of Sciences (India)

    Finny Monickaraj; Sankaramoorthy Aravind; Pichamoorthy Nandhini; Paramasivam Prabu; Chandrakumar Sathishkumar; Viswanathan Mohan; Muthuswamy Balasubramanyam

    2013-03-01

    Telomere shortening is emerging as a biological indicator of accelerated aging and aging-related diseases including type 2 diabetes. While telomere length measurements were largely done in white blood cells, there is lack of studies on telomere length in relation to oxidative stress in target tissues affected in diabetes. Therefore, the aim of this study is to induct oxidative stress in adipocytes and to test whether these adipocytes exhibit shortened telomeres, senescence and functional impairment. 3T3-L1 adipocytes were subjected to oxidative stress and senescence induction by a variety of means for 2 weeks (exogenous application of H2O2, glucose oxidase, asymmetric dimethylarginine (ADMA) and glucose oscillations). Cells were probed for reactive oxygen species generation (ROS), DNA damage, mRNA and protein expression of senescent and pro-inflammatory markers, telomere length and glucose uptake. Compared to untreated cells, both ROS generation and DNA damage were significantly higher in cells subjected to oxidative stress and senescence. Adipocytes subjected to oxidative stress also showed shortened telomeres and increased mRNA and protein expression of p53, p21, TNF and IL-6. Senescent cells were also characterized by decreased levels of adiponectin and impaired glucose uptake. Briefly, adipocytes under oxidative stress exhibited increased ROS generation, DNA damage, shortened telomeres and switched to senescent/pro-inflammatory phenotype with impaired glucose uptake.

  7. 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.

  8. Isolation and Characterization of Multipotent Mesenchymal Stem Cells Adhering to Adipocytes in Canine Bone Marrow.

    Science.gov (United States)

    Lin, Hsing-Yi; Fujita, Naoki; Endo, Kentaro; Morita, Maresuke; Takeda, Tae; Nakagawa, Takayuki; Nishimura, Ryohei

    2017-03-15

    The ceiling culture method has been used to isolate mature adipocytes from adipose tissue that can be dedifferentiated into fibroblastic cells, also known as dedifferentiated fat (DFAT) cells that self-renew and are multipotent, with much higher homogeneity and colony-forming efficiency than those of adipose tissue-derived mesenchymal stem cells. We cultured adipocytes from canine bone marrow using this technique, with the expectation of obtaining DFAT cells. However, contrary to our expectations, continuous monitoring of ceiling cultures by time-lapse microscopy revealed many small cells adhering to adipocytes that proliferated rapidly into cells with a fibroblastic morphology and without any dedifferentiation from adipocytes. We named these cells bone marrow peri-adipocyte cells (BM-PACs) and demonstrated the multipotent properties of BM-PACs compared to that of conventionally cultured canine bone marrow mesenchymal stem cells (BMMSCs). BM-PACs showed significantly greater clonogenicity and proliferation ability than BMMSCs. An in vitro trilineage differentiation assay revealed that BM-PACs possess adipogenic, osteogenic, and chondrogenic capacities superior to those of BMMSCs. Flow cytometric analysis revealed that the expression of CD73, which plays an important role in cell growth and differentiation, was significantly higher in BM-PACs than in BMMSCs. These results indicate that canine BM-PACs have stem cell characteristics that are superior to those of BMMSCs, and that these mesenchymal stem cells (MSCs) appear to be a feasible source for cell-based therapies in dogs.

  9. Mammary adipocytes stimulate breast cancer invasion through metabolic remodeling of tumor cells

    Science.gov (United States)

    Wang, Yuan Yuan; Attané, Camille; Milhas, Delphine; Dirat, Béatrice; Dauvillier, Stéphanie; Guerard, Adrien; Gilhodes, Julia; Lazar, Ikrame; Alet, Nathalie; Laurent, Victor; Le Gonidec, Sophie; Hervé, Caroline; Bost, Frédéric; Ren, Guo Sheng; Bono, Françoise; Escourrou, Ghislaine; Prentki, Marc; Nieto, Laurence; Valet, Philippe

    2017-01-01

    In breast cancer, a key feature of peritumoral adipocytes is their loss of lipid content observed both in vitro and in human tumors. The free fatty acids (FFAs), released by adipocytes after lipolysis induced by tumor secretions, are transferred and stored in tumor cells as triglycerides in lipid droplets. In tumor cell lines, we demonstrate that FFAs can be released over time from lipid droplets through an adipose triglyceride lipase–dependent (ATGL-dependent) lipolytic pathway. In vivo, ATGL is expressed in human tumors where its expression correlates with tumor aggressiveness and is upregulated by contact with adipocytes. The released FFAs are then used for fatty acid β-oxidation (FAO), an active process in cancer but not normal breast epithelial cells, and regulated by coculture with adipocytes. However, in cocultivated cells, FAO is uncoupled from ATP production, leading to AMPK/acetyl-CoA carboxylase activation, a circle that maintains this state of metabolic remodeling. The increased invasive capacities of tumor cells induced by coculture are completely abrogated by inhibition of the coupled ATGL-dependent lipolysis/FAO pathways. These results show a complex metabolic symbiosis between tumor-surrounding adipocytes and cancer cells that stimulate their invasiveness, highlighting ATGL as a potential therapeutic target to impede breast cancer progression. PMID:28239646

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

    Science.gov (United States)

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

    2012-02-01

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

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

    Science.gov (United States)

    Rebiger, Lars; Lenzen, Sigurd; Mehmeti, Ilir

    2016-01-21

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

  12. Expression of Caveolin 1 is enhanced by DNA demethylation during adipocyte differentiation. status of insulin signaling.

    Science.gov (United States)

    Palacios-Ortega, Sara; Varela-Guruceaga, Maider; Milagro, Fermín Ignacio; Martínez, José Alfredo; de Miguel, Carlos

    2014-01-01

    Caveolin 1 (Cav-1) is an essential constituent of adipocyte caveolae which binds the beta subunit of the insulin receptor (IR) and is implicated in the regulation of insulin signaling. We have found that, during adipocyte differentiation of 3T3-L1 cells the promoter, exon 1 and first intron of the Cav-1 gene undergo a demethylation process that is accompanied by a strong induction of Cav-1 expression, indicating that epigenetic mechanisms must have a pivotal role in this differentiation process. Furthermore, IR, PKB-Akt and Glut-4 expression are also increased during the differentiation process suggesting a coordinated regulation with Cav-1. Activation of Cav-1 protein by phosphorylation arises during the differentiation process, yet in fully mature adipocytes insulin is no longer able to significantly increase Cav-1 phosphorylation. However, these long-term differentiated cells are still able to respond adequately to insulin, increasing IR and PKB-Akt phosphorylation and glucose uptake. The activation of Cav-1 during the adipocyte differentiation process could facilitate the maintenance of insulin sensitivity by these fully mature adipocytes isolated from additional external stimuli. However, under the influence of physiological conditions associated to obesity, such as chronic inflammation and hypoxia, insulin sensitivity would finally be compromised.

  13. The aging process of skin and the increase in size of subcutaneous adipocytes.

    Science.gov (United States)

    Baldassarri, P; Calvani, M

    1994-01-01

    The aging of skin has been associated with an increase in size of the adipocytes located within the subcutaneous tissue. This topic is the subject of our study conducted on rats clinically treated with L-acetyl-carnitine (LAC) at 4, 8, 16, and 21 months of age and on a control group. Normal rats showed a significant increase in adipocyte diameter between four and eight months, and between sixteen and twenty-one months of age. Rats treated with L-acetyl-carnitine did not show significant changes up to the age of sixteen months, but did so between sixteen and twenty-one months of age. Four-month-old rats, both those under treatment and controls, did not show a significant change in adipocyte diameter. On the other hand, rats receiving L-acetyl-carnitine showed significantly smaller adipocyte diameters than those of the control group. Our results demonstrate that the long-term administration of L-acetyl-carnitine blocks the progressive increase in size of the subcutaneous adipocytes present in the rat's aging skin. We hypothesize that L-acetyl-carnitine reequilibrates the catabolic deficit of fats in the skin of the elderly.

  14. 4,4'-Dichlorodiphenyltrichloroethane (DDT) and 4,4'-dichlorodiphenyldichloroethylene (DDE) promote adipogenesis in 3T3-L1 adipocyte cell culture.

    Science.gov (United States)

    Kim, Jonggun; Sun, Quancai; Yue, Yiren; Yoon, Kyong Sup; Whang, Kwang-Youn; Marshall Clark, J; Park, Yeonhwa

    2016-07-01

    4,4'-Dichlorodiphenyltrichloroethane (DDT), a chlorinated hydrocarbon insecticide, was extensively used in the 1940s and 1950s. DDT is mainly metabolically converted into 4,4'-dichlorodiphenyldichloroethylene (DDE). Even though most countries banned DDT in the 1970s, due to the highly lipophilic nature and very stable characteristics, DDT and its metabolites are present ubiquitously in the environment, including food. Recently, there are publications on relationships between exposure to insecticides, including DDT and DDE, and weight gain and altered glucose homeostasis. However, there are limited reports regarding DDT or DDE and adipogenesis, thus we investigated effects of DDT and DDE on adipogenesis using 3T3-L1 adipocytes. Treatment of DDT or DDE resulted in increased lipid accumulation accompanied by increased expression of CCAAT/enhancer-binding protein α (C/EBPα), peroxisome-proliferator activated receptor-γ (PPARγ), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), adipose triglyceride lipase, and leptin. Moreover, treatment of DDT or DDE increased protein levels of C/EBPα, PPARγ, AMP-activated protein kinase-α (AMPKα), and ACC, while significant decrease of phosphorylated forms of AMPKα and ACC were observed. These finding suggest that increased lipid accumulation caused by DDT and DDE may mediate AMPKα pathway in 3T3-L1 adipocytes.

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

    Science.gov (United States)

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

    2015-07-01

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

  16. Mature adipocyte-derived dedifferentiated fat cells can transdifferentiate into skeletal myocytes in vitro.

    Science.gov (United States)

    Kazama, Tomohiko; Fujie, Masaki; Endo, Tuyoshi; Kano, Koichiro

    2008-12-19

    We have previously reported the establishment of preadipocyte cell lines, termed dedifferentiated fat (DFAT) cells, from mature adipocytes of various animals. DFAT cells possess long-term viability and can redifferentiate into adipocytes both in vivo and in vitro. Furthermore, DFAT cells can transdifferentiate into osteoblasts and chondrocytes under appropriate culture conditions. However, it is unclear whether DFAT cells are capable of transdifferentiating into skeletal myocytes, which is common in the mesodermal lineage. Here, we show that DFAT cells can be induced to transdifferentiate into skeletal myocytes in vitro. Myogenic induction of DFAT cells resulted in the expression of MyoD and myogenin, followed by cell fusion and formation of multinucleated cells expressing sarcomeric myosin heavy chain. These results indicate that DFAT cells derived from mature adipocytes can transdifferentiate into skeletal myocytes in vitro.

  17. 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

    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......, and adipocyte differentiation in a dose-dependent manner. Udgivelsesdato: 2003-Jun-6......Pref-1 is a highly glycosylated Delta-like transmembrane protein containing six epidermal growth factor-like repeats in the extracellular domain. Pref-1 is abundantly expressed in preadipocytes, but expression is down-regulated during adipocyte differentiation. Forced expression of Pref-1 in 3T3-L1...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  19. 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......, the presence of the PPARgamma 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 PPARgamma-stimulated proteins with a role in lipid metabolism. We observed an increase of lipoprotein...

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

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  1. 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 ...

  2. Anti-Inflammatory Effect of Spirulina platensis in Macrophages Is Beneficial for Adipocyte Differentiation and Maturation by Inhibiting Nuclear Factor-κB Pathway in 3T3-L1 Adipocytes.

    Science.gov (United States)

    Pham, Tho X; Lee, Ji-Young

    2016-06-01

    We previously showed that the organic extract of a blue-green alga, Spirulina platensis (SPE), had potent anti-inflammatory effects in macrophages. As the interplay between macrophages and adipocytes is critical for adipocyte functions, we investigated the contribution of the anti-inflammatory effects of SPE in macrophages to adipogenesis/lipogenesis in 3T3-L1 adipocytes. 3T3-L1 preadipocytes were treated with 10% conditioned medium from lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages (CMC) or LPS-stimulated, but SPE-pretreated, macrophages (CMS) at different stages of adipocyte differentiation. The expression of adipocyte differentiation markers, such as CCAAT/enhancer-binding protein α, peroxisome proliferator-activated receptor γ, and perilipin, was significantly repressed by CMC when added on day 3, while the repression was attenuated by CMS. Oil Red O staining confirmed that adipocyte maturation in CMS-treated cells, but not in CMC-treated cells, was equivalent to that of control cells. Nuclear translocation of nuclear factor κB (NF-κB) p65 was decreased by CMS compared to CMC. In lipid-laden adipocytes, CMC promoted the loss of lipid droplets, while CMS had minimal effects. Histone deacetylase 9 mRNA and protein levels were increased during adipocyte maturation, which were decreased by CMC. In conclusion, by cross-talking with adipocytes, the anti-inflammatory effects of SPE in macrophages promoted adipocyte differentiation/maturation, at least in part, by repressing the activation of NF-κB inflammatory pathways, which otherwise can be compromised in inflammatory conditions.

  3. Curcumin increases rat mesenchymal stem cell osteoblast differentiation but inhibits adipocyte differentiation

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    Qiaoli Gu

    2012-01-01

    Full Text Available Background: Curcumin is a phenolic natural product isolated from the rhizome of Curcuma longa (turmeric and has effects on bone health and fat formation. The bone marrow mesenchymal stem cells (MSCs are multipotent cells capable of differentiating into osteoblasts and adipocytes. Osteoblast differentiation of MSCs can be a result of upregulation of heme oxygenase (HO-1 expression. Curcumin can potently induce HO-1 expression. Objective: The present study describes the effects of curcumin on rat MSC (rMSCs differentiation into osteoblasts and adipocytes. Materials and Methods: Rat bone marrow MSCs were isolated and treated with or without curcumin. Osteoblast differentiation was confirmed and determined by alkaline phosphatase (ALP activity, mineralized nodule formation, the expression of Runx2 (runt-related transcription factor 2 and osteocalcin. Adipocyte differentiation was determined by Oil red O staining and the expression of peroxisome proliferator-activated receptor-γ 2 (PPARγ2 and CCAAT/enhancer-binding protein (C/EBP α. Results: Curcumin increased ALP activity and osteoblast-specific mRNA expression of Runx2 and osteocalcin when rMSCs were cultured in osteogenic medium. In contrast, curcumin decreased adipocyte differentiation and inhibited adipocyte-specific mRNA expression of PPARγ2 and C/EBPα when rMSCs were cultured in adipogenic medium. HO-1 expression was increased during osteogenic differentiation of rMSCs. Conclusions: These findings demonstrate that curcumin can promote osteogenic differentiation of rMSCs and inhibit adipocyte formation. The effect of curcumin on osteogenic differentiation of rMSCs is correlated with HO-1 expression.

  4. Differentiation-dependent expression of retinoid-binding proteins in BFC-1 beta adipocytes.

    Science.gov (United States)

    Zovich, D C; Orologa, A; Okuno, M; Kong, L W; Talmage, D A; Piantedosi, R; Goodman, D S; Blaner, W S

    1992-07-15

    Recently, we demonstrated that adipose tissue plays an important role in retinol storage and retinol-binding protein (RBP) synthesis. Our data suggested that RBP expression in adipose tissue is dependent on the state of adipocyte differentiation. To examine this possibility, we explored the differentiation-dependent expression of RBP using BFC-1 beta preadipocytes, which can be stimulated to undergo adipose differentiation. Total RNA was isolated from undifferentiated (preadipocytes) and differentiated (adipocytes) BFC-1 beta cells and analyzed by Northern blotting. RBP mRNA was not detected in the preadipocytes, but considerable RBP mRNA was present in differentiated BFC-1 beta cells. In BFC-1 beta cells, induced to differentiate with insulin and thyroid hormone, RBP mRNA was first detected after 4 days, reached a maximum level by day 10, and remained at this maximum level for at least 2 more days. Cellular retinol-binding protein was expressed at low levels in the BFC-1 beta preadipocytes and the level of expression increased for 6 days after induction to differentiate and slowly declined on later days. Neither the maximum level of RBP expression nor the day on which this level was reached was influenced by the level of retinol provided in the BFC-1 beta culture medium. BFC-1 beta cells secreted newly synthesized RBP into the culture medium at a rate of 43 +/- 14 ng RBP/24 h/10(6) adipocytes. When the BFC-1 beta adipocytes were provided 1.0 microM retinol in the medium, they accumulated the retinol and synthesized retinyl esters. These studies with BFC-1 beta cells confirm that RBP synthesis and secretion and retinol accumulation are intrinsic properties of differentiated adipocytes. Furthermore, they suggest that RBP and cellular retinol-binding protein gene expression are regulated as part of a package of genes which are modulated during adipocyte differentiation.

  5. 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

    2010-04-01

    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.

  6. 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:

  7. Lipolysis and apoptosis of adipocytes induced by neuropeptide Y—Y5 receptor antisense oligodeoxynucleotides in obese rats

    Institute of Scientific and Technical Information of China (English)

    GONGHai-Xia; GUOXi-Rong; FEILi; GUOMei; LIUQian-Qi; CHENRong-Hua

    2003-01-01

    AIM:To investigate the influence of central administration of neuropeptide Y-Y5 receptor antisense oligodeoxynucleotides(ODN) on the body weight and fat pads of high-energy diet-induced obese rats, and the effects on white adipocyte lipolysis and apoptosis. METHODS: Y5 receptor antisense, sense, mismatched oligodeoxynucleotides (ODN) or vehicle were intracerebroventricularly injected, and average adipocyte area was calculated. DNA ladders were measured to evaluate adipocyte apoptosis, and RT-PCR was used to analyze the expression of bcl-2 and bax gene. RESULTS: (1) Central administration of Y5 receptor antisense ODN significantly decreased body weight, fat pads, and average adipocyte area. (2) DNA fragmentation was presented after electrophoresis at both epididymal and retroperitoneal adipose tissue. (3) The expression of bcl-2 gene was downregulated, while the expression of bax was upregulated. CONCLUSION:Lipolysis and adipocyte apoptosis may be important reasons for Y5 receptor antisense therapy.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  9. 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

    normal and hormone-sensitive lipase (HSL)-null mice and in phosphatase-treated islets, indicating that the stimulatory effect was neither on HSL nor phosphorylation dependent. In contrast, we reproduced the previously published observations showing inhibition of HSL activity by LC-CoA in adipocytes....... 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...

  10. 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 BACKGROUND: 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. METHODOLOGY AND PRINCIPAL FINDINGS: 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. CONCLUSION AND SIGNIFICANCE: 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.

  11. The adipocyte component of bone marrow in heterotopic bone induced by demineralized incisor grafts The adipocyte component of bone marrow in heterotopic bone induced by demineralized incisor grafts

    Directory of Open Access Journals (Sweden)

    Krzysztof H. Włodarski

    2012-10-01

    Full Text Available The relative proportion of adipocytes to hematopoietic elements in the marrow of heterotopically
    induced bone evaluated 4–42 weeks post implantation of demineralized murine incisors was estimated by histological
    analysis of hematoxylin-eosin stained tissue sections. Using computerized image analysis of microphotographs,
    the proportion of nuclear cells vs. adipocytes was ascertained. The percentage of adipocytes in marrow
    increases over time. Such an effect, the replacement of myelopoietic marrow by adipogenic (yellow marrow
    and the resorption of induced bone, is observed in human osteoporosis. A decline in the non-adipogenic cell
    compartments of bone marrow accompanying induced bone begins in the fourth week of induction, gradually
    progresses until the 26th week, and does not change after that. The luminosity, a parameter used in image analysis
    and proportional to the number of nuclear cells, was 124 ± 3 in hematopoietic femoral bone marrow, and
    that of bone marrow of the induced bone was of a similar value (117 ± 8 in the fourth week. An evident decline
    in luminosity of bone marrow filling the foci of heterotopic bone was observed in samples taken at nine weeks
    (82 ± 20. This process progressed until the 26th week, reaching a luminosity of 70 ± 21. At the 42nd week, the
    luminosity remained at the same level (71 ± 27. This indicates that the replacement of hematopoietic bone
    marrow of heterotopically induced bone by unilocular adipocytes begins relatively early (the fourth week and is
    persistent.The relative proportion of adipocytes to hematopoietic elements in the marrow of heterotopically
    induced bone evaluated 4–42 weeks post implantation of demineralized murine incisors was estimated by histological
    analysis of hematoxylin-eosin stained tissue sections. Using computerized image analysis of microphotographs,
    the proportion of nuclear cells vs

  12. 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

  13. 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

  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. 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.

  16. 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

    The melanocortin receptors (MCRs) belong to the G-protein coupled receptors (family A). So far, 5 different subtypes have been described (MC1R-MC5R) and of these MC2R and MC5R have been proposed to act directly in adipocytes and regulate lipolysis in rodents. Using ACTH and a-melanocyte stimulating...

  17. Rubi Fructus (Rubus coreanus) Inhibits Differentiation to Adipocytes in 3T3-L1 Cells.

    Science.gov (United States)

    Jeong, Mi-Young; Kim, Hye-Lin; Park, Jinbong; An, Hyo-Jin; Kim, Sung-Hoon; Kim, Su-Jin; So, Hong-Seob; Park, Raekil; Um, Jae-Young; Hong, Seung-Heon

    2013-01-01

    Rubi Fructus (RF) is known to exert several pharmacological effects including antitumor, antioxidant, and anti-inflammatory activities. However, its antiobesity effect has not been reported yet. This study was focused on the antidifferentiation effect of RF extract on 3T3-L1 preadipocytes. When 3T3-L1 preadipocytes were differentiating into adipocytes, 10-100  μ g/mL of RF was added. Next, the lipid contents were quantified by Oil Red O staining. RF significantly reduced lipid accumulation and downregulated the expression of peroxisome proliferator-activated receptor γ (PPAR γ ), CCAAT0-enhancer-binding proteins α (C/EBP α ), adipocyte fatty acid-binding protein 2 (aP2), resistin, and adiponectin in ways that were concentration dependent. Moreover, RF markedly upregulated liver kinase B1 and AMP-activated protein kinase (AMPK). Interestingly, pretreatment with AMPK α siRNA and RF downregulated the expression of PPAR γ and C/EBP α protein as well as the adipocyte differentiation. Our study shows that RF is capable of inhibiting the differentiation of 3T3-L1 adipocytes through the modulation of PPAR γ , C/EBP α , and AMPK, suggesting that it has a potential for therapeutic application in the treatment or prevention of obesity.

  18. 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.

  19. Perilipin Promotes HSL-Mediated Adipocyte Lipolysis via Phosphorylation-dependent and Independent Mechanisms

    Science.gov (United States)

    Hormone-sensitive lipase (HSL) is the predominant lipase effector of catecholamine-stimulated lipolysis in adipocytes. HSL-dependent lipolysis, in response to catecholamines, is mediated by protein kinase A (PKA)-dependent phosphorylation of perilipin A (Peri A), an essential lipid droplet (LD)-ass...

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

    Science.gov (United States)

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

    2015-01-01

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

  1. 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.

  2. Effects of leptin on apoptosis and adipogenesis in 3T3-L1 adipocytes.

    Science.gov (United States)

    Ambati, Suresh; Kim, Hye-Kyeong; Yang, Jeong-Yeh; Lin, Ji; Della-Fera, Mary Anne; Baile, Clifton A

    2007-02-01

    Leptin has been demonstrated to induce adipose tissue apoptosis, which can contribute to the decrease of adiposity, after either central nervous system or peripheral administration. However, it is not known whether leptin acts only centrally to initiate a signal or can also act directly on adipocytes to induce apoptosis. The objective of this study was to determine the direct effect of leptin on adipocyte apoptosis and adipogenesis in vitro using 3T3-L1 cell lines. An ELISA for single stranded DNA, which is highly specific for apoptotic cells, was used to quantify apoptosis. Preconfluent preadipocytes treated with 10(-9), 10(-8), 10(-7), and 10(-6)M leptin showed inhibitory effects on cell viability, and similar observations were also found in maturing preadipocytes treated during day 0-2 and day 2-4 of maturation. After 48 h incubation with 10(-6)M leptin, LDH release was increased by 24.3% (p<0.05) in preconfluent preadipocytes and by 108.5% (p<0.01) in maturing preadipocytes. However, ssDNA analysis revealed no increased apoptosis in preconfluent or maturing preadipocytes or in mature adipocytes treated with leptin. Leptin significantly reduced lipid accumulation and GPDH activity in maturing preadipocytes, demonstrating an inhibitory effect of leptin on adipogenesis. These results indicate that leptin does not act directly to induce adipocyte apoptosis, but can act directly to inhibit maturation of preadipocytes.

  3. Anti-obesity effects of xanthohumol plus guggulsterone in 3T3-L1 adipocytes.

    Science.gov (United States)

    Rayalam, Srujana; Yang, Jeong-Yeh; Della-Fera, Mary Anne; Park, Hea Jin; Ambati, Suresh; Baile, Clifton A

    2009-08-01

    Xanthohumol (XN) and guggulsterone (GS) have each been shown to inhibit adipogenesis and induce apoptosis in adipocytes. In the present study effects of the combination of XN + GS on 3T3-L1 adipocyte apoptosis and adipogenesis were investigated. Mature adipocytes were treated with XN and GS individually and in combination. XN and GS individually decreased cell viability, but XN + GS caused an enhanced decrease in viability and potentiated induction of apoptosis. Likewise, XN + GS caused a potentiated increase in caspase-3/7 activation, whereas neither of the compounds showed any effect individually. In addition, western blot analysis revealed that XN + GS increased Bax expression and decreased Bcl-2 expression, whereas individual compounds did not show any significant effect. XN and GS both decreased lipid accumulation. Individually, XN at 1.5 microM and GS at 3.12 microM decreased lipid accumulation by 26 +/- 4.5% (P < .001) each, whereas XN1.5 + GS3.12 decreased lipid accumulation by 78.2 +/- 1.8% (P < .001). Moreover, expression of the adipocyte-specific proteins was down-regulated with XN1.5 + GS3.12, but no effect was observed with the individual compounds. Finally, XN + GS caused an enhanced stimulation of lipolysis. Thus, combination of XN and GS is more potent in exerting anti-obesity effects than additive effects of the individual compounds.

  4. 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

    2015-01-01

    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. PMID:25743104

  5. Glucose-dependent insulinotropic polypeptide induces cytokine expression, lipolysis, and insulin resistance in human adipocytes.

    Science.gov (United States)

    Timper, Katharina; Grisouard, Jean; Sauter, Nadine S; Herzog-Radimerski, Tanja; Dembinski, Kaethi; Peterli, Ralph; Frey, Daniel M; Zulewski, Henryk; Keller, Ulrich; Müller, Beat; Christ-Crain, Mirjam

    2013-01-01

    Obesity-related insulin resistance is linked to a chronic state of systemic and adipose tissue-derived inflammation. Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone also acting on adipocytes. We investigated whether GIP affects inflammation, lipolysis, and insulin resistance in human adipocytes. Human subcutaneous preadipocyte-derived adipocytes, differentiated in vitro, were treated with human GIP to analyze mRNA expression and protein secretion of cytokines, glycerol, and free fatty acid release and insulin-induced glucose uptake. GIP induced mRNA expression of IL-6, IL-1β, and the IL-1 receptor antagonist IL-1Ra, whereas TNFα, IL-8, and monocyte chemotactic protein (MCP)-1 remained unchanged. Cytokine induction involved PKA and the NF-κB pathway as well as an autocrine IL-1 effect. Furthermore, GIP potentiated IL-6 and IL-1Ra secretion in the presence of LPS, IL-1β, and TNFα. GIP induced lipolysis via activation of hormone-sensitive lipase and was linked to NF-κB activation. Finally, chronic GIP treatment impaired insulin-induced glucose uptake possibly due to the observed impaired translocation of glucose transporter GLUT4. In conclusion, GIP induces an inflammatory and prolipolytic response via the PKA -NF-κB-IL-1 pathway and impairs insulin sensitivity of glucose uptake in human adipocytes.

  6. Caffeic Acid Phenethyl Ester Regulates PPAR's Levels in Stem Cells-Derived Adipocytes

    Science.gov (United States)

    Vanella, Luca; Tibullo, Daniele; Godos, Justyna; Pluchinotta, Francesca Romana; Di Giacomo, Claudia; Sorrenti, Valeria; Acquaviva, Rosaria; Russo, Alessandra; Li Volti, Giovanni; Barbagallo, Ignazio

    2016-01-01

    Hypertrophic obesity inhibits activation of peroxisome proliferators-activated receptor gamma (PPARγ), considered the key mediator of the fully differentiated and insulin sensitive adipocyte phenotype. We examined the effects of Caffeic Acid Phenethyl Ester (Cape), isolated from propolis, a honeybee hive product, on Adipose Stem Cells (ASCs) differentiation to the adipocyte lineage. Finally we tested the effects of Cape on insulin-resistant adipocytes. Quantification of Oil Red O-stained cells showed that lipid droplets decreased following Cape treatment as well as radical oxygen species formation. Additionally, exposure of ASC to high glucose levels decreased adiponectin and increased proinflammatory cytokines mRNA levels, which were reversed by Cape-mediated increase of insulin sensitivity. Cape treatment resulted in decreased triglycerides synthesis and increased beta-oxidation. Exposure of ASCs to Lipopolysaccharide (LPS) induced a reduction of PPARγ, an increase of IL-6 levels associated with a well-known stimulation of lipolysis; Cape partially attenuated the LPS-mediated effects. These observations reveal the main role of PPARγ in the adipocyte function and during ASC differentiation. As there is now substantial interest in functional food and nutraceutical products, the observed therapeutic value of Cape in insulin-resistance related diseases should be taken into consideration. PMID:26904104

  7. Caffeic Acid Phenethyl Ester Regulates PPAR’s Levels in Stem Cells-Derived Adipocytes

    Directory of Open Access Journals (Sweden)

    Luca Vanella

    2016-01-01

    Full Text Available Hypertrophic obesity inhibits activation of peroxisome proliferators-activated receptor gamma (PPARγ, considered the key mediator of the fully differentiated and insulin sensitive adipocyte phenotype. We examined the effects of Caffeic Acid Phenethyl Ester (Cape, isolated from propolis, a honeybee hive product, on Adipose Stem Cells (ASCs differentiation to the adipocyte lineage. Finally we tested the effects of Cape on insulin-resistant adipocytes. Quantification of Oil Red O-stained cells showed that lipid droplets decreased following Cape treatment as well as radical oxygen species formation. Additionally, exposure of ASC to high glucose levels decreased adiponectin and increased proinflammatory cytokines mRNA levels, which were reversed by Cape-mediated increase of insulin sensitivity. Cape treatment resulted in decreased triglycerides synthesis and increased beta-oxidation. Exposure of ASCs to Lipopolysaccharide (LPS induced a reduction of PPARγ, an increase of IL-6 levels associated with a well-known stimulation of lipolysis; Cape partially attenuated the LPS-mediated effects. These observations reveal the main role of PPARγ in the adipocyte function and during ASC differentiation. As there is now substantial interest in functional food and nutraceutical products, the observed therapeutic value of Cape in insulin-resistance related diseases should be taken into consideration.

  8. St. John's Wort Has Metabolically Favorable Effects on Adipocytes In Vivo.

    Science.gov (United States)

    Fuller, Scott; Richard, Allison J; Ribnicky, David M; Beyl, Robbie; Mynatt, Randall; Stephens, Jacqueline M

    2014-01-01

    In addition to serving as a storage site for reserve energy, adipocytes play a critical role in whole-body insulin sensitivity and glucose metabolism. St. John's Wort (SJW) is a botanical supplement widely used as an over-the-counter treatment of depression and a variety of other conditions associated with anxiety and nerve pain. Previous studies in our laboratory demonstrated that SJW inhibits insulin-stimulated glucose uptake and adipocyte differentiation in cultured murine and mature human adipocytes. To investigate the effects of SJW on adipocyte function in vivo, we utilized C57BL/6J mice. In our studies, mice were administered SJW extract (200 mg/kg) once daily by gavage for two weeks. In contrast to our in vitro studies, mice treated with SJW extract showed increased levels of adiponectin in white adipose tissue in a depot specific manner (P < 0.01). SJW also exerted an insulin-sensitizing effect as indicated by a significant increase in insulin-stimulated Akt serine phosphorylation in epididymal white adipose tissue (P < 0.01). Food intake, body weight, fasting blood glucose, and fasting insulin did not differ between the two groups. These results are important as they indicate that SJW does not promote metabolic dysfunction in adipose tissue in vivo.

  9. Mature adipocytes in bone marrow protect myeloma cells against chemotherapy through autophagy activation

    Science.gov (United States)

    A major problem in patients with multiple myeloma is chemotherapy resistance, which develops in myeloma cells upon interaction with bone marrow stromal cells. However, few studies have determined the role of bone marrow adipocytes, a major component of stromal cells in the bone marrow, in myeloma ch...

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

    Science.gov (United States)

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

    2015-01-01

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

  11. Polyacetylenes from carrots (Daucus carota) improve glucose uptake in vitro in adipocytes and myotubes.

    Science.gov (United States)

    El-Houri, Rime B; Kotowska, Dorota; Christensen, Kathrine B; Bhattacharya, Sumangala; Oksbjerg, Niels; Wolber, Gerhard; Kristiansen, Karsten; Christensen, Lars P

    2015-07-01

    A dichloromethane (DCM) extract of carrot roots was found to stimulate insulin-dependent glucose uptake (GU) in adipocytes in a dose dependent manner. Bioassay-guided fractionation of the DCM extract resulted in the isolation of the polyacetylenes falcarinol and falcarindiol. Both polyacetylenes were able to significantly stimulate basal and/or insulin-dependent GU in 3T3-L1 adipocytes and porcine myotube cell cultures in a dose-dependent manner. Falcarindiol increased peroxisome proliferator-activated receptor (PPAR)γ-mediated transactivation significantly at concentrations of 3, 10 and 30 μM, while PPARγ-mediated transactivation by falcarinol was only observed at 10 μM. Docking studies accordingly indicated that falcarindiol binds to the ligand binding domain of PPARγ with higher affinity than falcarinol and that both polyacetylenes exhibit characteristics of PPARγ partial agonists. Falcarinol was shown to inhibit adipocyte differentiation as evident by gene expression studies and Oil Red O staining, whereas falcarindiol did not inhibit adipocyte differentiation, which indicates that these polyacetylenes have distinct modes of action. The results of the present study suggest that falcarinol and falcarindiol may represent scaffolds for novel partial PPARγ agonists with possible antidiabetic properties.

  12. Retinyl ester hydrolysis and retinol efflux from BFC-1beta adipocytes.

    Science.gov (United States)

    Wei, S; Lai, K; Patel, S; Piantedosi, R; Shen, H; Colantuoni, V; Kraemer, F B; Blaner, W S

    1997-05-30

    Adipose tissue is an important storage depot for retinol, but there are no data regarding retinol mobilization from adipose stores. To address this, dibutyryl cAMP was provided to murine BFC-1beta adipocytes and its effects on retinol efflux assessed. High performance liquid chromatography analysis of retinol and retinyl esters in adipocytes and media indicated that cAMP stimulated, in a time- and dose-dependent manner, retinol accumulation in the culture media and decreased cellular retinyl ester concentrations. Study of adipocyte retinol-binding protein synthesis and secretion indicated that cAMP-stimulated retinol efflux into the media did not result from increased retinol-retinol-binding protein secretion but was dependent on the presence of fetal bovine serum in the culture media. Since our data suggested that retinyl esters can be hydrolyzed by a cAMP-dependent enzyme like hormone-sensitive lipase (HSL), in separate studies, we purified a HSL-containing fraction from BFC-1beta adipocytes and demonstrated that it catalyzed retinyl palmitate hydrolysis. Homogenates of Chinese hamster ovary cells overexpressing HSL catalyzed retinyl palmitate hydrolysis in a time-, protein-, and substrate-dependent manner, with an apparent Km for retinyl palmitate of 161 microM, whereas homogenates from control Chinese hamster ovary cells did not.

  13. Acute Genome-wide effects of Rosiglitazone on PPARγ transcriptional networks in Adipocytes

    DEFF Research Database (Denmark)

    Haakonsson, Anders Kristian; Madsen, Maria Stahl; Nielsen, Ronni

    2013-01-01

    on the transcriptional network of PPARγ in adipocytes. Treatment with rosiglitazone for 1 hour leads to acute transcriptional activation as well as repression of a number of genes as determined by genome-wide RNA polymerase II occupancy. Unlike what has been shown for many other nuclear receptors, agonist treatment does...

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

    Directory of Open Access Journals (Sweden)

    Dave Bridges

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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.

  15. Pulicaria jaubertii extract prevents triglyceride deposition in 3T3-L1 adipocytes

    Science.gov (United States)

    Currently, levels of obesity in Middle Eastern countries are increasing. Phytochemicals have anti-obesogenic properties as evidenced by prevention of adipocyte differentiation. In Yemen, Pulicaria jaubertii E.Gamal-Eldin (PJ) is a food additive and a traditional medicine. We tested the ability of ex...

  16. 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

    The nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR gamma) is essential for adipogenesis. Although several fatty acids and their derivatives are known to bind and activate PPAR gamma, the nature of the endogenous ligand(s) promoting the early stages of adipocyte differenti...

  17. Crotonis Fructus and Its Constituent, Croton Oil, Stimulate Lipolysis in OP9 Adipocytes

    Directory of Open Access Journals (Sweden)

    Mi-Seong Kim

    2014-01-01

    Full Text Available Introduction. Crotonis fructus (CF is the mature fruit of Croton tiglium L. and has been used for the treatment of gastrointestinal disturbance in Asia. It is well known that the main component of CF is croton oil (CO. The present study is to investigate the effects of CF extracts (CFE and CO on lipolysis in OP9 adipocytes. Methods. Glycerol release to the culture supernatants was used as a marker of adipocyte lipolysis. Results. Treatment with various concentrations of CFE and CO stimulates glycerol release in a dose-dependent manner. The increase in glycerol release by CFE is more potent than isoproterenol, which is a β-adrenergic agonist as a positive control in our system. The increased lipolysis by CFE and CO was accompanied by an increase of phosphorylated hormone sensitive lipase (pHSL but not nonphosphorylated HSL protein and mRNA. Pretreatment with H89, which is a protein kinase A inhibitor, significantly abolished the CFE- and CO-induced glycerol release in OP9 adipocytes. These results suggest that CFE and CO may be a candidate for the development of a lipolysis-stimulating agent in adipocytes.

  18. 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...

  19. 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...

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

    Science.gov (United States)

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

  1. 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...

  2. Iron metabolism is associated with adipocyte insulin resistance and plasma adiponectin

    NARCIS (Netherlands)

    Wlazlo, N.; Greevenbroek, van M.M.J.; Ferreira, I.; Jansen, E.H.J.M.; Feskens, E.J.M.; Kallen, van der C.J.H.; Schalkwijk, C.G.; Bravenboer, B.; Stehouwer, C.D.A.

    2013-01-01

    OBJECTIVE-Adipocyte insulin resistance (IR) is a key feature early in the pathogenesis of type 2 diabetes mellitus (T2DM), and although scarce, data in the literature suggest a direct role for iron and iron metabolism-related factors in adipose tissue function and metabolism. Serum ferritin and tran

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

    Science.gov (United States)

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

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

    NARCIS (Netherlands)

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

    2002-01-01

    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 experiments

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

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    Billon, Nathalie; Dani, Christian

    2012-03-01

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

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

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    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.

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

    Science.gov (United States)

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

    2017-03-15

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

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

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    Shan, Tizhong; Liu, Weiyi; Kuang, Shihuan

    2013-01-01

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

  9. Characterization of human mesenchymal stem cell secretome at early steps of adipocyte and osteoblast differentiation

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    Alessi Marie-Christine

    2008-02-01

    Full Text Available Abstract Background It is well established that adipose tissue plays a key role in energy storage and release but is also a secretory organ and a source of stem cells. Among different lineages, stem cells are able to differentiate into adipocytes and osteoblasts. As secreted proteins could regulate the balance between both lineages, we aimed at characterizing the secretome of human multipotent adipose-derived stem cell (hMADS at an early step of commitment to adipocytes and osteoblasts. Results A proteomic approach, using mono-dimensional electrophoresis and tandem mass spectrometry, allowed us to identify a total of 73 proteins at day 0 and day 3 of adipocyte and osteoblast differentiation. Analysis of identified proteins showed that 52 % corresponded to classical secreted proteins characterized by a signal peptide, that 37 % previously described in the extracellular compartment were devoid of signal peptide and that 11 % neither exhibited a signal peptide nor had been previously described extracellularly. These proteins were classified into 8 clusters according to their function. Quantitative analysis has been performed for 8 candidates: PAI-1, PEDF, BIGH3, PTX3, SPARC, ENO1, GRP78 and MMP2. Among them, PAI-1 was detected at day 0 and day 3 of osteoblast differentiation but never in adipocyte secretome. Furthermore we showed that PAI-1 mRNA was down-regulated in the bone of ovariectomized mice. Conclusion Given its regulation during the early events of hMADS cell differentiation and its status in ovariectomized mice, PAI-1 could play a role in the adipocyte/osteoblast balance and thus in bone diseases such as osteoporosis.

  10. Characterization of human mesenchymal stem cell secretome at early steps of adipocyte and osteoblast differentiation

    Science.gov (United States)

    Chiellini, Chiara; Cochet, Olivia; Negroni, Luc; Samson, Michel; Poggi, Marjorie; Ailhaud, Gérard; Alessi, Marie-Christine; Dani, Christian; Amri, Ez-Zoubir

    2008-01-01

    Background It is well established that adipose tissue plays a key role in energy storage and release but is also a secretory organ and a source of stem cells. Among different lineages, stem cells are able to differentiate into adipocytes and osteoblasts. As secreted proteins could regulate the balance between both lineages, we aimed at characterizing the secretome of human multipotent adipose-derived stem cell (hMADS) at an early step of commitment to adipocytes and osteoblasts. Results A proteomic approach, using mono-dimensional electrophoresis and tandem mass spectrometry, allowed us to identify a total of 73 proteins at day 0 and day 3 of adipocyte and osteoblast differentiation. Analysis of identified proteins showed that 52 % corresponded to classical secreted proteins characterized by a signal peptide, that 37 % previously described in the extracellular compartment were devoid of signal peptide and that 11 % neither exhibited a signal peptide nor had been previously described extracellularly. These proteins were classified into 8 clusters according to their function. Quantitative analysis has been performed for 8 candidates: PAI-1, PEDF, BIGH3, PTX3, SPARC, ENO1, GRP78 and MMP2. Among them, PAI-1 was detected at day 0 and day 3 of osteoblast differentiation but never in adipocyte secretome. Furthermore we showed that PAI-1 mRNA was down-regulated in the bone of ovariectomized mice. Conclusion Given its regulation during the early events of hMADS cell differentiation and its status in ovariectomized mice, PAI-1 could play a role in the adipocyte/osteoblast balance and thus in bone diseases such as osteoporosis. PMID:18302751

  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. St. John's Wort inhibits insulin signaling in murine and human adipocytes.

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    Richard, Allison J; Amini, Zhaleh J; Ribnicky, David M; Stephens, Jacqueline M

    2012-04-01

    Adipocytes are insulin-sensitive cells that play a major role in energy homeostasis. Obesity is the primary disease of fat cells and a major risk factor for the development of Type 2 diabetes, cardiovascular disease, and metabolic syndrome. The use of botanicals in the treatment of metabolic diseases is an emerging area of research. In previous studies, we screened over 425 botanical extracts for their ability to modulate adipogenesis and insulin sensitivity. We identified St. John's Wort (SJW) extracts as inhibitors of adipogenesis of 3T3-L1 cells and demonstrated that these extracts also inhibited insulin-sensitive glucose uptake in mature fat cells. In these follow-up studies we have further characterized the effects of SJW on insulin action in both murine and human fat cells. We have shown that SJW also attenuates insulin-sensitive glucose uptake in human adipocytes. Moreover, SJW inhibits IRS-1 tyrosine phosphorylation in both murine and human fat cells. Botanical extracts are complex mixtures. Many bioactive compounds have been identified in SJW, including hypericin (HI) and hyperforin (HF). We have examined the ability of HI and HF, purified from SJW, to modulate adipocyte development and insulin action in mature adipocytes. Our novel studies indicate that the profound effects of SJW on adipogenesis, IRS-1 activation, and insulin-stimulated glucose uptake are not mediated by HI and/or HF. Nonetheless, we propose that extracts of SJW may contribute to adipocyte related diseases by limiting differentiation of preadipocytes and significantly inducing insulin resistance in mature fat cells.

  13. 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.

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

    Science.gov (United States)

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

    2016-12-01

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

  15. Combined effects of genistein, quercetin, and resveratrol in human and 3T3-L1 adipocytes.

    Science.gov (United States)

    Park, Hea Jin; Yang, Jeong-Yeh; Ambati, Suresh; Della-Fera, Mary Anne; Hausman, Dorothy B; Rayalam, Srujana; Baile, Clifton A

    2008-12-01

    The natural compounds genistein (G), quercetin (Q), and resveratrol (R) have been reported to each exhibit anti-adipogenic activities in adipocytes and antiproliferative and pro-apoptotic activities in several cell types. We studied the combined effects of G, Q, and R on adipogenesis and apoptosis in primary human adipocytes (HAs) and 3T3-L1 murine adipocyte (MAs). Combined treatment with 6.25 microM G, 12.5 microM Q, and 12.5 microM R during the 14-day differentiation period caused an enhanced inhibition of lipid accumulation in maturing HAs that was greater than the responses to individual compounds and to the calculated additive response. Glycerol 3-phosphate dehydrogenase activity, a marker of late adipocyte differentiation, was decreased markedly in HAs treated with the combination of G+Q+R. In addition, combined treatment with 50 microM G, 100 microM Q, and 100 microM R for 3 days decreased cell viability and induced apoptosis in early- and mid- phase maturing and lipid-filled mature HAs. In contrast, no compound alone induced apoptosis. Oil Red O stain and Hoechst 33342 stain were performed to confirm the effects on lipid accumulation and apoptosis, respectively. We also determined whether MAs responded to the combination treatment similarly to HAs. As in HAs, G+Q+R treatment decreased lipid accumulation in maturing MAs and increased apoptosis in pre- and lipid-filled mature MAs more than the responses to G, Q, and R when used separately. These results show that lower concentrations of combined treatments with several natural compounds may be useful for treatments for obesity through the suppression of adipogenesis and enhanced adipocyte apoptosis.

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

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    Kumaratilake Jaliya S

    2008-04-01

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

  17. Acute genome-wide effects of rosiglitazone on PPARγ transcriptional networks in adipocytes.

    Science.gov (United States)

    Haakonsson, Anders Kristian; Stahl Madsen, Maria; Nielsen, Ronni; Sandelin, Albin; Mandrup, Susanne

    2013-09-01

    Peroxisome proliferator-activated receptor γ (PPARγ) is a master regulator of adipocyte differentiation, and genome-wide studies indicate that it is involved in the induction of most adipocyte genes. Here we report, for the first time, the acute effects of the synthetic PPARγ agonist rosiglitazone on the transcriptional network of PPARγ in adipocytes. Treatment with rosiglitazone for 1 hour leads to acute transcriptional activation as well as repression of a number of genes as determined by genome-wide RNA polymerase II occupancy. Unlike what has been shown for many other nuclear receptors, agonist treatment does not lead to major changes in the occurrence of PPARγ binding sites. However, rosiglitazone promotes PPARγ occupancy at many preexisting sites, and this is paralleled by increased occupancy of the mediator subunit MED1. The increase in PPARγ and MED1 binding is correlated with an increase in transcription of nearby genes, indicating that rosiglitazone, in addition to activating the receptor, also promotes its association with DNA, and that this is causally linked to recruitment of mediator and activation of genes. Notably, both rosiglitazone-activated and -repressed genes are induced during adipogenesis. However, rosiglitazone-activated genes are markedly more associated with PPARγ than repressed genes and are highly dependent on PPARγ for expression in adipocytes. By contrast, repressed genes are associated with the other key adipocyte transcription factor CCAAT-enhancer binding proteinα (C/EBPα), and their expression is more dependent on C/EBPα. This suggests that the relative occupancies of PPARγ and C/EBPα are critical for whether genes will be induced or repressed by PPARγ agonist.

  18. 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.

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

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    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.

  20. High density lipoprotein (HDL promotes glucose uptake in adipocytes and glycogen synthesis in muscle cells.

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    Qichun Zhang

    Full Text Available BACKGROUND: High density lipoprotein (HDL was reported to decrease plasma glucose and promote insulin secretion in type 2 diabetes patients. This investigation was designed to determine the effects and mechanisms of HDL on glucose uptake in adipocytes and glycogen synthesis in muscle cells. METHODS AND RESULTS: Actions of HDL on glucose uptake and GLUT4 translocation were assessed with 1-[(3H]-2-deoxyglucose and plasma membrane lawn, respectively, in 3T3-L1 adipocytes. Glycogen analysis was performed with amyloglucosidase and glucose oxidase-peroxidase methods in normal and palmitate-treated L6 cells. Small interfering RNA was used to observe role of scavenger receptor type I (SR-BI in glucose uptake of HDL. Corresponding signaling molecules were detected by immunoblotting. HDL stimulated glucose uptake in a time- and concentration-dependent manner in 3T3-L1 adipocytes. GLUT4 translocation was significantly increased by HDL. Glycogen deposition got enhanced in L6 muscle cells paralleling with elevated glycogen synthase kinase3 (GSK3 phosphorylation. Meanwhile, increased phosphorylations of Akt-Ser473 and AMP activated protein kinase (AMPK α were detected in 3T3-L1 adipocytes. Glucose uptake and Akt-Ser473 activation but not AMPK-α were diminished in SR-BI knock-down 3T3-L1 cells. CONCLUSIONS: HDL stimulates glucose uptake in 3T3-L1 adipocytes through enhancing GLUT4 translocation by mechanisms involving PI3K/Akt via SR-BI and AMPK signaling pathways, and increases glycogen deposition in L6 muscle cells through promoting GSK3 phosphorylation.

  1. PLAG1 alterations in lipoblastoma: involvement in varied mesenchymal cell types and evidence for alternative oncogenic mechanisms.

    Science.gov (United States)

    Gisselsson, D; Hibbard, M K; Dal Cin, P; Sciot, R; Hsi, B L; Kozakewich, H P; Fletcher, J A

    2001-09-01

    Lipoblastomas are rare soft tissue tumors that occur primarily in young children. They typically contain variably differentiated adipocytes, primitive mesenchymal cells, myxoid matrix, and fibrous trabeculae. Abnormalities in chromosome 8, leading to rearrangements of the PLAG1 gene, were demonstrated recently in four lipoblastomas. In the present report, we determine the frequency of PLAG1 alterations in 16 lipoblastomas from children aged 13 years or younger, and we also evaluate the stages of lipoblastoma differentiation at which PLAG1 genomic alterations are found. Eleven lipoblastomas (69%), including those with either classic or lipoma-like histology, had rearrangements of the 8q12 PLAG1 region. Another three lipoblastomas had polysomy for chromosome 8 in the absence of PLAG1 rearrangement. Only two cases (13%) lacked a chromosome 8 abnormality. Notably, the lipoblastomas with chromosome 8 polysomy had up to five copies of chromosome 8 as an isolated cytogenetic finding in an otherwise diploid cell. We also demonstrate that PLAG1 alterations are found in a spectrum of mesenchymal cell types in lipoblastomas, including lipoblasts, mature adipocytes, primitive mesenchymal cells, and fibroblast-like cells. This finding is consistent with neoplastic origin in a primitive mesenchymal precursor and with variable differentiation to a mature adipocyte end-point. Hence, our studies provide biological validation for the clinical observation that lipoblastomas can evolve into mature, lipoma-like, lesions. They also suggest that PLAG1 dosage alterations caused by polysomy 8 might represent an alternative oncogenic mechanism in lipoblastoma.

  2. 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

  3. 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

    We have undertaken a systematic proteomic approach to purify and identify secreted factors that are differentially expressed in preadipocytes versus adipocytes. Using one-dimensional gel electrophoresis combined with nanoelectrospray tandem mass spectrometry, proteins that were specifically secre...

  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. Phenotypic shift of adipocytes by cholecalciferol and 1α,25 dihydroxycholecalciferol in relation to inflammatory status and calcium content.

    Science.gov (United States)

    Zoico, Elena; Franceschetti, Guido; Chirumbolo, Salvatore; Rossi, Andrea P; Mazzali, Gloria; Rizzatti, Vanni; Budui, Simona; Zamboni, Mauro

    2014-11-01

    Recent experimental data seem to suggest a relevant role for 1,25[OH]2cholecalciferol (1,25[OH]2D3) in adipocyte physiology and pathophysiology, with some studies showing adipogenic and pro-inflammatory properties, and others lipolytic and anti-inflammatory functions. Moreover, to our knowledge, the role of cholecalciferol (D3) in adipocytes function is still not known. Therefore, the aim of this study was to investigate in vitro the effects of 1,25[OH]2D3, as well as of D3, in 3T3-L1 adipocytes in basal and inflammatory conditions, testing the effects of different calcium concentrations in adipocytes culture medium. In 3T3-L1 adipocytes, CYP27A1 and CYP27B1 mRNA were detected in basal conditions and induced after D3 treatment. Pre-treatment of 3T3-L1 adipocytes not only with 1,25[OH]2D3, but also with D3 before inflammatory stimulation, significantly prevented the increase in gene expression and protein secretion of IL-6 and TNF-α, and significantly increased IL-10 mRNA and protein production compared with adipocytes treated only with lipopolysaccharide (LPS). Biological effects of D3 were still present after inhibition of P450 activity with ketokonazole. LPS determined a decrease in cell area compared with controls, paralleled by a significant increase in optical density (OD) of lipid droplets, whereas 1,25[OH]2D3 and D3 alone significantly increased adipocytes area and decreased OD. Pretreatment with both forms of vitamin D preserved cells from the reduction in their area observed after LPS treatment. LPS decreased more the area of cells grown in a high calcium medium than of adipocytes grown in a low calcium medium. In the presence of a high calcium medium, 1,25(OH)2D3 treatment preserved cell area, maintaining its anti-inflammatory and adipogenic properties. In conclusion our results show that D3, besides 1,25[OH]2D3, presents anti-inflammatory effects on 3T3-L1, as well as that adipocytes have the enzymatic pathways necessary to locally regulate the

  6. Effect of Tumor Necrosis Factor-α on Resistin Expression in 3T3-L1 Adipocytes and Its Mechanism

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In order to investigate the effect of tumor necrosis factor-α (TNFα) on resistin expression in 3T3-L1 adipocytes, and further explore its mechanisms, the differentiated 3T3-L1 adipocytes were incubated with 0, 1, 10, 100 ng/mL TNFα respectively for 24 h, and then the expression of resistin was determined. The differentiated 3T3-L1 adipocytes were incubated with 100 ng/mL TNFα for 3, 6, 24 h respectively, and then the expression of resistin mRNA was analyzed.3T3-L1 adipocytes were induced to differentiate into mature adipocytes. The cells were randomly divided into 4 groups for culture. In the control group, no drugs were added. Cells of TNFα group were treated with 100 ng/mL TNFα. In Ro-31-8220 group, 5μmol/L protein kinase C inhibitor Ro-31-8220 was added. With TNFα+Ro-31-8220 group, 100 ng/mL TNFα were added 1 h after the addition of 5 μmol/L Ro-31-8220. All adipocytes were cultured for 24 h. Reverse transcriptionpolymerase chain reaction (RT-PCR) and Western blotting were employed to detect the expression of resistin gene. Our results showed that resistin protein and mRNA in 3T3-L1 adipocytes were inhibited by TNFα at different concentrations (P<0.01), and the inhibitory effect increased with the concentration (P<0.01). At the same concentrations, the inhibitory effect increased with time (P <0.01). Ro-31-8220 could inhibit its expression and the inhibitive effect remained unchanged with addition of TNFα(P>0.05). It was concluded that TNFα could inhibit the expression of resistin in 3T3-L1 adipocytes. The mechanism may be that the expression of resistin is partly controlled by protein kinase C signal conduction pathway.

  7. Advanced application of porcine intramuscular adipocytes for evaluating anti-adipogenic and anti-inflammatory activities of immunobiotics.

    Directory of Open Access Journals (Sweden)

    Masahiko Suzuki

    Full Text Available We previously established a clonal porcine intramuscular preadipocyte (PIP line and we were able to establish a protocol to obtain functional mature adipocytes from PIP cells. We hypothesized that both PIP cells and mature adipocytes are likely to be useful in vitro tools for increasing our understanding of immunobiology of adipose tissue, and for the selection and study of immunoregulatory probiotics (immunobiotics able to modulate adipocytes immune responses. In this study, we investigated the immunobiology of PIP cells and mature adipocytes in relation to their response to TNF-α stimulation. In addition, we evaluated the possibility that immunobiotic microorganisms modify adipogenesis and immune functions of porcine adipose tissue through Peyer's patches (PPs immune-competent cells. We treated the porcine PPs immune cells with different probiotic strains; and we evaluated the effect of conditioned media from probiotic-stimulated immune cells in PIP cells and mature adipocytes. The Lactobacillus GG and L. gasseri TMC0356 showed remarkable effects, and were able to significantly reduce the expression of pro-inflammatory factors and negative regulators (A20, Bcl-3, and MKP-1 in adipocytes challenged with TNF-α. The results of this study demonstrated that the evaluation of IL-6, and MCP-1 production, and A20 and Bcl-3 down-regulation in TNF-α-challenged adipocytes could function as biomarkers to screen and select potential immunobiotic strains. Taking into consideration that several in vivo and in vitro studies clearly demonstrated the beneficial effects of Lactobacillus GG and L. gasseri TMC0356 in adipose inflammation, the results presented in this work indicate that the PIP cells and porcine adipocytes could be used for the screening and the selection of new immunobiotic strains with the potential to functionally modulate adipose inflammation when orally administered.

  8. Differential roles of CIDEA and CIDEC in insulin-induced anti-apoptosis and lipid droplet formation in human adipocytes.

    Science.gov (United States)

    Ito, Minoru; Nagasawa, Michiaki; Hara, Tomoko; Ide, Tomohiro; Murakami, Koji

    2010-07-01

    Both insulin and the cell death-inducing DNA fragmentation factor-alpha-like effector (CIDE) family play important roles in apoptosis and lipid droplet formation. However, regulation of the CIDE family by insulin and the contribution of the CIDE family to insulin actions remain unclear. Here, we investigated whether insulin regulates expression of the CIDE family and which subtypes contribute to insulin-induced anti-apoptosis and lipid droplet formation in human adipocytes. Insulin decreased CIDEA and increased CIDEC but not CIDEB mRNA expression. Starvation-induced apoptosis in adipocytes was significantly inhibited when insulin decreased the CIDEA mRNA level. Small interfering RNA-mediated depletion of CIDEA inhibited starvation-induced apoptosis similarly to insulin and restored insulin deprivation-reduced adipocyte number, whereas CIDEC depletion did not. Lipid droplet size of adipocytes was increased when insulin increased the CIDEC mRNA level. In contrast, insulin-induced enlargement of lipid droplets was markedly abrogated by depletion of CIDEC but not CIDEA. Furthermore, depletion of CIDEC, but not CIDEA, significantly increased glycerol release from adipocytes. These results suggest that CIDEA and CIDEC are novel genes regulated by insulin in human adipocytes and may play key roles in the effects of insulin, such as anti-apoptosis and lipid droplet formation.

  9. Establishment of a preadipocyte cell line derived from mature adipocytes of GFP transgenic mice and formation of adipose tissue.

    Science.gov (United States)

    Nobusue, Hiroyuki; Endo, Tsuyoshi; Kano, Koichiro

    2008-06-01

    We established a preadipocyte cell line from mature adipocytes obtained from subcutaneous fat tissue of green fluorescent protein (GFP) transgenic mice. The floating top layer, containing mature adipocytes, was isolated from subcutaneous fat tissue by collagenase digestion and filtration. Fluorescence-activated cell sorting and microscopic analysis revealed that the floating cell fraction comprised a highly homogeneous adipocyte population with no adipose stromal-vascular cells. Isolated mature adipocytes dedifferentiated into fibroblast-like cells and actively proliferated in ceiling culture. In vitro studies showed that the cells could redifferentiate into mature adipocytes in an identical way to 3T3-L1 preadipocytes. No changes in the differentiation pattern were observed during the propagation of our cells. They were successfully maintained and differentiated for at least 22 passages. We named these cells dedifferentiated fat (DFAT-GFP) cells. When DFAT-GFP cells were implanted subcutaneously into C57BL/6N mice, they developed highly vascularized fat pads that morphologically resembled normal subcutaneous adipose tissue and consisted of GFP-positive cells; however, implanted 3T3-L1 cells did not have such an effect on the mice. We conclude that DFAT-GFP cells provide a model that should enable us to study the mechanisms of adipocyte differentiation and adipose tissue formation in vivo and in vitro.

  10. Inhibition of adipogenesis and induction of apoptosis and lipolysis by stem bromelain in 3T3-L1 adipocytes.

    Directory of Open Access Journals (Sweden)

    Sandeep Dave

    Full Text Available The phytotherapeutic protein stem bromelain (SBM is used as an anti-obesity alternative medicine. We show at the cellular level that SBM irreversibly inhibits 3T3-L1 adipocyte differentiation by reducing adipogenic gene expression and induces apoptosis and lipolysis in mature adipocytes. At the molecular level, SBM suppressed adipogenesis by downregulating C/EBPα and PPARγ independent of C/EBPβ gene expression. Moreover, mRNA levels of adipocyte fatty acid-binding protein (ap2, fatty acid synthase (FAS, lipoprotein lipase (LPL, CD36, and acetyl-CoA carboxylase (ACC were also downregulated by SBM. Additionally, SBM reduced adiponectin expression and secretion. SBM's ability to repress PPARγ expression seems to stem from its ability to inhibit Akt and augment the TNFα pathway. The Akt-TSC2-mTORC1 pathway has recently been described for PPARγ expression in adipocytes. In our experiments, TNFα upregulation compromised cell viability of mature adipocytes (via apoptosis and induced lipolysis. Lipolytic response was evident by downregulation of anti-lipolytic genes perilipin, phosphodiestersae-3B (PDE3B, and GTP binding protein G(iα(1, as well as sustained expression of hormone sensitive lipase (HSL. These data indicate that SBM, together with all-trans retinoic-acid (atRA, may be a potent modulator of obesity by repressing the PPARγ-regulated adipogenesis pathway at all stages and by augmenting TNFα-induced lipolysis and apoptosis in mature adipocytes.

  11. Rapamycin Improves Palmitate-Induced ER Stress/NF κ B Pathways Associated with Stimulating Autophagy in Adipocytes

    Directory of Open Access Journals (Sweden)

    Jiajing Yin

    2015-01-01

    Full Text Available Obesity-induced endoplasmic reticulum (ER stress and inflammation lead to adipocytes dysfunction. Autophagy helps to adapt to cellular stress and involves in regulating innate inflammatory response. In present study, we examined the activity of rapamycin, a mTOR kinase inhibitor, against endoplasmic reticulum stress and inflammation in adipocytes. An in vitro model was used in which 3T3-L1 adipocytes were preloaded with palmitate (PA to generate artificial hypertrophy mature adipocytes. Elevated autophagy flux and increased number of autophagosomes were observed in response to PA and rapamycin treatment. Rapamycin attenuated PA-induced PERK and IRE1-associated UPR pathways, evidenced by decreased protein levels of eIF2α phosphorylation, ATF4, CHOP, and JNK phosphorylation. Inhibiting autophagy with chloroquine (CQ exacerbated these ER stress markers, indicating the role of autophagy in ameliorating ER stress. In addition, cotreatment of CQ abolished the anti-ER stress effects of rapamycin, which confirms the effect of rapamycin on ERs is autophagy-dependent. Furthermore, rapamycin decreased PA-induced nuclear translocation of NFκB P65 subunit, thereby NFκB-dependent inflammatory cytokines MCP-1 and IL-6 expression and secretion. In conclusion, rapamycin attenuated PA-induced ER stress/NFκB pathways to counterbalance adipocytes stress and inflammation. The beneficial of rapamycin in this context partly depends on autophagy. Stimulating autophagy may become a way to attenuate adipocytes dysfunction.

  12. Rapamycin improves palmitate-induced ER stress/NF κ B pathways associated with stimulating autophagy in adipocytes.

    Science.gov (United States)

    Yin, Jiajing; Gu, Liping; Wang, Yufan; Fan, Nengguang; Ma, Yuhang; Peng, Yongde

    2015-01-01

    Obesity-induced endoplasmic reticulum (ER) stress and inflammation lead to adipocytes dysfunction. Autophagy helps to adapt to cellular stress and involves in regulating innate inflammatory response. In present study, we examined the activity of rapamycin, a mTOR kinase inhibitor, against endoplasmic reticulum stress and inflammation in adipocytes. An in vitro model was used in which 3T3-L1 adipocytes were preloaded with palmitate (PA) to generate artificial hypertrophy mature adipocytes. Elevated autophagy flux and increased number of autophagosomes were observed in response to PA and rapamycin treatment. Rapamycin attenuated PA-induced PERK and IRE1-associated UPR pathways, evidenced by decreased protein levels of eIF2α phosphorylation, ATF4, CHOP, and JNK phosphorylation. Inhibiting autophagy with chloroquine (CQ) exacerbated these ER stress markers, indicating the role of autophagy in ameliorating ER stress. In addition, cotreatment of CQ abolished the anti-ER stress effects of rapamycin, which confirms the effect of rapamycin on ERs is autophagy-dependent. Furthermore, rapamycin decreased PA-induced nuclear translocation of NFκB P65 subunit, thereby NFκB-dependent inflammatory cytokines MCP-1 and IL-6 expression and secretion. In conclusion, rapamycin attenuated PA-induced ER stress/NFκB pathways to counterbalance adipocytes stress and inflammation. The beneficial of rapamycin in this context partly depends on autophagy. Stimulating autophagy may become a way to attenuate adipocytes dysfunction.

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

    Science.gov (United States)

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

    2016-04-05

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

  14. Inhibition of mitotic clonal expansion mediates fisetin-exerted prevention of adipocyte differentiation in 3T3-L1 cells.

    Science.gov (United States)

    Lee, Youngyi; Bae, Eun Ju

    2013-11-01

    Adipocytes are the key player in adipose tissue inflammation and subsequent systemic insulin resistance and its development involves complex process of proliferation and differentiation of preadipocytes. Fistein, a polyphenol flavonoid, is known to exert anti-inflammatory, anti-carcinogenic and anti-diabetic effects. In this study, we aimed to investigate the effect of fisetin on adipocyte proliferation and differentiation in 3T3-L1 preadipocyte cell line and its mechanism of action. We found that fisetin inhibits adipocyte differentiation in a concentration dependent manner, which were evidenced by Oil Red O staining and the protein expression of mature adipocyte marker genes fatty acid synthase and peroxisome proliferator-activated receptor γ. Moreover, the proliferation of preadipocytes was also markedly suppressed by treatment of fisetin for 24 and 48 h in the differentiation medium. We also found that fisetin inhibition of adipocyte differentiation was largely due to the effect on mitotic clonal expansion. Fisetin suppression of preadipocyte proliferation at early stage of differentiation was accompanied by the changes of expression of a series of cell cycle regulatory proteins. Altogether, our results suggest that the inhibition of adipocyte differentiation by fisetin may be at least in part mediated by cell cycle arrest during adipogenesis.

  15. Endogenous oils derived from human adipocytes are potent adjuvants that promote IL-1α-dependent inflammation.

    Science.gov (United States)

    Tynan, Graham A; Hearnden, Claire H; Oleszycka, Ewa; Lyons, Claire L; Coutts, Graham; O'Connell, Jean; Corrigan, Michelle A; Lynch, Lydia; Campbell, Matthew; Callanan, John J; Mok, Kenneth H; Geoghegan, Justin; O'Farrelly, Cliona; Allan, Stuart M; Roche, Helen M; O'Shea, Donal B; Lavelle, Ed C

    2014-06-01

    Obesity is characterized by chronic inflammation associated with neutrophil and M1 macrophage infiltration into white adipose tissue. However, the mechanisms underlying this process remain largely unknown. Based on the ability of oil-based adjuvants to induce immune responses, we hypothesized that endogenous oils derived from necrotic adipocytes may function as an immunological "danger signal." Here we show that endogenous oils of human origin are potent adjuvants, enhancing antibody responses to a level comparable to Freund's incomplete adjuvant. The endogenous oils were capable of promoting interleukin (IL)-1α-dependent recruitment of neutrophils and M1-like macrophages, while simultaneously diminishing M2-like macrophages. We found that endogenous oils from subcutaneous and omental adipocytes, and from healthy and unhealthy obese individuals, promoted comparable inflammatory responses. Furthermore, we also confirmed that white adipocytes in visceral fat of metabolically unhealthy obese (MUO) individuals are significantly larger than those in metabolically healthy obese individuals. Since adipocyte size is positively correlated with adipocyte death, we propose that endogenous oils have a higher propensity to be released from hypertrophied visceral fat in MUO individuals and that this is the key factor in driving inflammation. In summary, this study shows that adipocytes contain a potent oil adjuvant which drives IL-1α-dependent proinflammatory responses in vivo.

  16. Intracerebroventricular administration of galanin antagonist sustains insulin resistance in adipocytes of type 2 diabetic trained rats.

    Science.gov (United States)

    Zhang, Zhenwen; Sheng, Shudong; Guo, Lili; Li, Guangzhi; Zhang, Ling; Zhang, Linxiang; Shi, Mingyi; Bo, Ping; Zhu, Yan

    2012-09-25

    The aim of this study is to investigate whether galanin (GAL) central receptors are involved in regulation of insulin resistance. To test it, a GAL antagonist, M35 was intracerebroventricularly administrated in trained type 2 diabetic rats. The euglycemic-hyperinsulinemic clamp test was conducted for an index of glucose infusion rates. The epididymal fat pads were processed for determination of glucose uptake and Glucose Transporter 4 (GLUT4) amounts. The Gal mRNA expression levels in hypothalamus were quantitatively assessed too. We found an inhibitory effect of M35 on glucose uptake into adipocytes, Gal mRNA expression levels in hypothalamus, glucose infusion rates in the clamp test and GLUT4 concentration in plasma membranes and total cell membranes of adipocytes. The ratios of GLUT4 contents of the former to the latter in M35 groups were lower. These results suggest a facilitating role for GAL on GLUT4 translocation and insulin sensitivity via its central receptors in rats.

  17. The phenotype and tissue-specific nature of multipotent cells derived from human mature adipocytes.

    Science.gov (United States)

    Kou, Liang; Lu, Xiao-Wen; Wu, Min-Ke; Wang, Hang; Zhang, Yu-Jiao; Sato, Soh; Shen, Jie-Fei

    2014-02-21

    Dedifferentiated fat (DFAT) cells derived from mature adipocytes have been considered to be a homogeneous group of multipotent cells, which present to be an alternative source of adult stem cells for regenerative medicine. However, many aspects of the cellular nature about DFAT cells remained unclarified. This study aimed to elucidate the basic characteristics of DFAT cells underlying their functions and differentiation potentials. By modified ceiling culture technique, DFAT cells were converted from human mature adipocytes from the human buccal fat pads. Flow cytometry analysis revealed that those derived cells were a homogeneous population of CD13(+) CD29(+) CD105(+) CD44(+) CD31(-) CD34(-) CD309(-) α-SMA(-) cells. DFAT cells in this study demonstrated tissue-specific differentiation properties with strong adipogenic but much weaker osteogenic capacity. Neither did they express endothelial markers under angiogenic induction.

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

    Institute of Scientific and Technical Information of China (English)

    Anne-Laure; Hafner; Christian; Dani

    2014-01-01

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

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

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  20. The tumor suppressors pRB and p53 as regulators of adipocyte differentiation and function

    DEFF Research Database (Denmark)

    Hallenborg, Philip; Feddersen, Søren; Madsen, Lise;

    2009-01-01

    BACKGROUND: The retinoblastoma protein (pRB) and p53 are crucial members of regulatory networks controlling the cell cycle and apoptosis, and a hallmark of virtually all cancers is dysregulation of expression or function of pRB or p53. Although they are best known for their role in cancer...... development, it is now evident that both are implicated in metabolism and cellular development. OBJECTIVE/METHODS: To review the role of pRB and p53 in adipocyte differentiation and function emphasizing that pRB and p53, via their effects on adipocyte development and function, play a role in the regulation...... of energy metabolism and homeostasis. RESULTS/CONCLUSIONS: pRB is required for adipose conversion and also involved in determining its mitochondrial capacity. p53 inhibits adipogenesis and results suggest that it is involved in maintaining function of adipose tissue....

  1. Adipocyte Mineralocorticoid Receptor Activation Leads to Metabolic Syndrome and Induction of Prostaglandin D2 Synthase.

    Science.gov (United States)

    Urbanet, Riccardo; Nguyen Dinh Cat, Aurelie; Feraco, Alessandra; Venteclef, Nicolas; El Mogrhabi, Soumaya; Sierra-Ramos, Catalina; Alvarez de la Rosa, Diego; Adler, Gail K; Quilliot, Didier; Rossignol, Patrick; Fallo, Francesco; Touyz, Rhian M; Jaisser, Frédéric

    2015-07-01

    Metabolic syndrome is a major risk factor for the development of diabetes mellitus and cardiovascular diseases. Pharmacological antagonism of the mineralocorticoid receptor (MR), a ligand-activated transcription factor, limits metabolic syndrome in preclinical models, but mechanistic studies are lacking to delineate the role of MR activation in adipose tissue. In this study, we report that MR expression is increased in visceral adipose tissue in a preclinical mouse model of metabolic syndrome and in obese patients. In vivo conditional upregulation of MR in mouse adipocytes led to increased weight and fat mass, insulin resistance, and metabolic syndrome features without affecting blood pressure. We identified prostaglandin D2 synthase as a novel MR target gene in adipocytes and AT56, a specific inhibitor of prostaglandin D2 synthase enzymatic activity, blunted adipogenic aldosterone effects. Moreover, translational studies showed that expression of MR and prostaglandin D2 synthase is strongly correlated in adipose tissues from obese patients.

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

    Directory of Open Access Journals (Sweden)

    Markelić Milica

    2011-01-01

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

  3. Deregulated MAPK activity prevents adipocyte differentiation of fibroblasts lacking the retinoblastoma protein

    DEFF Research Database (Denmark)

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

    2002-01-01

    A functional retinoblastoma protein (pRB) is required for adipose conversion of preadipocyte cell lines and primary mouse embryo fibroblasts (MEFs) in response to treatment with standard adipogenic inducers. Interestingly, lack of functional pRB in MEFs was recently linked to elevated Ras activity....../Akt are significantly increased in pRB-deficient MEFs both before and after the addition of adipogenic inducers. Consistently, we detected higher levels of activated Ras in MEFs lacking pRB. Suppression of ERK1/2 activation by the MEK inhibitor UO126 restored the ability of pRB-deficient MEFs to undergo adipocyte...... differentiation, as manifested by expression of adipocyte marker genes and lipid accumulation. Furthermore and reflecting the elevated levels of activated PKB/Akt in the pRB-deficient MEFs, differentiation proceeded in an insulin-independent manner. In conclusion, we suggest that pRB plays a pivotal role...

  4. 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...

  5. Dopaminergic Differentiation of Human Embryonic Stem Cells on PA6-Derived Adipocytes.

    Science.gov (United States)

    Guloglu, M Oktar; Larsen, Anna

    2016-01-01

    Human embryonic stem cells (hESCs) are a promising source for cell replacement therapies. Parkinson's disease is one of the candidate diseases for the cell replacement therapy since the motor manifestations of the disease are associated with the loss of dopaminergic neurons in the substantia nigra pars compacta. Stromal cell-derived inducing activity (SDIA) is the most commonly used method for the dopaminergic differentiation of hESCs. This chapter describes a simple, reliable, and scalable dopaminergic induction method of hESCs using PA6-derived adipocytes. Coculturing hESCs with PA6-derived adipocytes markedly reduces the variable outcomes among experiments. Moreover, the colony differentiation step of this method can also be used for the dopaminergic induction of mouse embryonic stem cells and NTERA2 cells as well.

  6. White Tea extract induces lipolytic activity and inhibits adipogenesis in human subcutaneous (pre-adipocytes

    Directory of Open Access Journals (Sweden)

    Wenck Horst

    2009-05-01

    Full Text Available Abstract Background The dramatic increase in obesity-related diseases emphasizes the need to elucidate the cellular and molecular mechanisms underlying fat metabolism. To investigate how natural substances influence lipolysis and adipogenesis, we determined the effects of White Tea extract on cultured human subcutaneous preadipocytes and adipocytes. Methods For our in vitro studies we used a White Tea extract solution that contained polyphenols and methylxanthines. Utilizing cultured human preadipocytes we investigated White Tea extract solution-induced inhibition of triglyceride incorporation during adipogenesis and possible effects on cell viability. In vitro studies on human adipocytes were performed aiming to elucidate the efficacy of White Tea extract solution to stimulate lipolytic activity. To characterize White Tea extract solution-mediated effects on a molecular level, we analyzed gene expression of essential adipogenesis-related transcription factors by qRT-PCR and determined the expression of the transcription factor ADD1/SREBP-1c on the protein level utilizing immunofluorescence analysis. Results Our data show that incubation of preadipocytes with White Tea extract solution significantly decreased triglyceride incorporation during adipogenesis in a dose-dependent manner (n = 10 without affecting cell viability (n = 10. These effects were, at least in part, mediated by EGCG (n = 10, 50 μM. In addition, White Tea extract solution also stimulated lipolytic activity in adipocytes (n = 7. Differentiating preadipocytes cultivated in the presence of 0.5% White Tea extract solution showed a decrease in PPARγ, ADD1/SREBP-1c, C/EBPα and C/EBPδ mRNA levels. Moreover, the expression of the transcription factor ADD1/SREBP-1c was not only decreased on the mRNA but also on the protein level. Conclusion White Tea extract is a natural source that effectively inhibits adipogenesis and stimulates lipolysis-activity. Therefore, it can be utilized to

  7. Go-6976 reverses hyperglycemia-induced insulin resistance independently of cPKC inhibition in adipocytes.

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    Katherine A Robinson

    Full Text Available 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.

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

    OpenAIRE

    Marcelin, Genevieve; Chua, Streamson

    2010-01-01

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

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

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    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.

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

    Science.gov (United States)

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

    2013-05-01

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

  11. Increased 4-hydroxynonenal formation contributes to obesity-related lipolytic activation in adipocytes.

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    Ximei Zhang

    Full Text Available Oxidative stress in adipose tissue plays an etiological role in a variety of obesity-related metabolic disorders. We previously reported that increased adipose tissue 4-hydroxynonenal (4-HNE contents contributed to obesity-related plasma adiponectin decline in mice. In the present study, we investigated the effects of intracellular 4-HNE accumulation on lipolytic response in adipocytes/adipose tissues and underlying mechanisms. In both fully-differentiated 3T3-L1 and primary adipocytes, a 5-hour 4-HNE exposure elevated lipolytic reaction in a dose-dependent manner at both basal and isoproterenol-stimulated conditions, evidenced by significantly increased glycerol and fatty acids releases. This conclusion was corroborated by the comparable observations when the minced human visceral adipose tissues were used. Mechanistic investigations revealed that 4-HNE-stimulated lipolytic activation is multifactorial. 4-HNE exposure quickly increased intracellular cyclic AMP (cAMP level, which was concomitant with increased phosphorylations of protein kinase A (PKA and its direct downstream target, hormone sensitive lipase (HSL. Pre-incubation with H89, a potent PKA inhibitor, prevented 4-HNE stimulated glycerol release, suggesting that enhanced lipolytic action in response to 4-HNE increase is mediated mainly by cAMP/PKA signal pathway in adipocytes. In addition to activating cAMP/PKA/HSL pathway, 4-HNE exposure also suppresses AMP-activated protein kinase (AMPK, a suppressive pathway for lipolysis, measured by both Western blotting for phosphorylated form of AMPK and ELISA for enzyme activity. Furthermore, 5-Aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside (AICAR, a pharmacological AMPK activator, alleviated 4-HNE-induced lipolysis, suggesting that AMPK suppression also contributes to 4-HNE elicited lipolytic response. In conclusion, our findings indicate that increased intracellular 4-HNE accumulation in adipocytes/adipose tissues contributes to

  12. Cholecalciferol inhibits lipid accumulation by regulating early adipogenesis in cultured adipocytes and zebrafish.

    Science.gov (United States)

    Kim, Joo Hyoun; Kang, Smee; Jung, Yu Na; Choi, Hyeon-Son

    2016-01-15

    Cholecalciferol (CCF) is a common dietary supplement as a precursor of active vitamin D. In the present study, the effect of CCF on lipid accumulation was investigated in adipocyte cells and zebrafish models. CCF effectively inhibited lipid accumulation in both experimental models; this effect was attributed to the CCF-mediated regulation of early adipogenic factors. CCF down-regulated the expressions of CCAAT-enhancer-binding protein-β (C/EBPβ), C/EBPδ, Krueppel-like factor (KLF) 4, and KLF5, while KLF2, a negative adipogenic regulator, was increased by CCF treatment. CCF inhibited cell cycle progression of adipocytes through down-regulation of cyclin A and cyclinD; p-Rb was suppressed by CCF, but p27 was up-regulated with CCF treatment. This CCF-mediated inhibition of cell cycle progression is highly correlated to the inhibitions of extracellular signal-regulated kinase (ERK), serine threonine-specific kinase (AKT), and mammalian target of rapamycin (mTOR). Furthermore, CCF-induced inactivation of acetyl-CoA carboxylase (ACC), a fatty acid synthetic enzyme, with the activation of AMP-activated protein kinase α (AMPKα) was also observed. Consistent with the observations in adipocytes, CCF effectively inhibited lipid accumulation with the down-regulation of adipogenic factors in zebrafish. The present study indicates that CCF showed anti-adipogenic effect in adipocytes and zebrafish, and its inhibitory effect was involved in the regulation of early adipogenic events including cell cycle arrest and activation of AMPKα signaling.

  13. Adipocyte protein modification by Krebs cycle intermediates and fumarate ester-derived succination.

    Science.gov (United States)

    Manuel, Allison M; Frizzell, Norma

    2013-11-01

    Protein succination, the non-enzymatic modification of cysteine residues by fumarate, is distinguishable from succinylation, an enzymatic reaction forming an amide bond between lysine residues and succinyl-CoA. Treatment of adipocytes with 30 mM glucose significantly increases protein succination with only a small change in succinylation. Protein succination may be significantly increased intracellularly after treatment with fumaric acid esters, however, the ester must be removed by saponification to permit 2SC-antibody detection of the fumarate adduct.

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

    OpenAIRE

    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 rosiglitazo...

  15. Hypochlorous acid via peroxynitrite activates protein kinase Cθ and insulin resistance in adipocytes.

    Science.gov (United States)

    Zhou, Jun; Wang, Qilong; Ding, Ye; Zou, Ming-Hui

    2015-02-01

    We recently reported that genetic deletion of myeloperoxidase (MPO) alleviates obesity-related insulin resistance in mice in vivo. How MPO impairs insulin sensitivity in adipocytes is poorly characterized. As hypochlorous acid (HOCl) is a principal oxidant product generated by MPO, we evaluated the effects of HOCl on insulin signaling in adipocytes differentiated from 3T3-L1 cells. Exposure of 3T3-L1 adipocytes to exogenous HOCl (200 μmol/l) attenuated insulin-stimulated 2-deoxyglucose uptake, GLUT4 translocation, and insulin signals, including tyrosine phosphorylation of insulin receptor substrate 1 (IRS1) and phosphorylation of Akt. Furthermore, treatment with HOCl induced phosphorylation of IRS1 at serine 307, inhibitor κB kinase (IKK), c-Jun NH2-terminal kinase (JNK), and phosphorylation of PKCθ (PKCθ). In addition, genetic and pharmacological inhibition of IKK and JNK abolished serine phosphorylation of IRS1 and impairment of insulin signaling by HOCl. Furthermore, knockdown of PKCθ using siRNA transfection suppressed phosphorylation of IKK and JNK and consequently attenuated the HOCl-impaired insulin signaling pathway. Moreover, activation of PKCθ by peroxynitrite was accompanied by increased phosphorylation of IKK, JNK, and IRS1-serine 307. In contrast, ONOO(-) inhibitors abolished HOCl-induced phosphorylation of PKCθ, IKK, JNK, and IRS1-serine 307, as well as insulin resistance. Finally, high-fat diet (HFD)-induced insulin resistance was associated with enhanced phosphorylation of PKCθ, IKK, JNK, and IRS1 at serine 307 in white adipose tissues from WT mice, all of which were not found in Mpo knockout mice fed HFDs. We conclude that HOCl impairs insulin signaling pathway by increasing ONOO(-) mediated phosphorylation of PKCθ, resulting in phosphorylation of IKK/JNK and consequent serine phosphorylation of IRS1 in adipocytes.

  16. Signaling pathways involved in LPS induced TNFalpha production in human adipocytes

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    Festy Franck

    2010-01-01

    Full Text Available Abstract Background The development of obesity has been linked to an inflammatory process, and the role of adipose tissue in the secretion of pro-inflammatory molecules such as IL-6 or TNFalpha has now been largely confirmed. Although TNFalpha secretion by adipose cells is probably induced, most notably by TLR ligands, the activation and secretion pathways of this cytokine are not yet entirely understood. Moreover, given that macrophagic infiltration is a characteristic of obesity, it is difficult to clearly establish the level of involvement of the different cellular types present within the adipose tissue during inflammation. Methods Primary cultures of human adipocytes and human peripheral blood mononuclear cells were used. Cells were treated with a pathogen-associated molecular pattern: LPS, with and without several kinase inhibitors. Western blot for p38 MAP Kinase was performed on cell lysates. TNFalpha mRNA was detected in cells by RT-PCR and TNFalpha protein was detected in supernatants by ELISA assays. Results We show for the first time that the production of TNFalpha in mature human adipocytes is mainly dependent upon two pathways: NFkappaB and p38 MAP Kinase. Moreover, we demonstrate that the PI3Kinase pathway is clearly involved in the first step of the LPS-pathway. Lastly, we show that adipocytes are able to secrete a large amount of TNFalpha compared to macrophages. Conclusion This study clearly demonstrates that the LPS induced activation pathway is an integral part of the inflammatory process linked to obesity, and that adipocytes are responsible for most of the secreted TNFalpha in inflamed adipose tissue, through TLR4 activation.

  17. Luteolin suppresses TCDD-induced wasting syndrome in a cultured adipocyte model.

    Science.gov (United States)

    Ashida, Hitoshi; Harada, Kiyonari; Mishima, Sakiho; Mitani, Takakazu; Yamashita, Yoko; Matsumura, Fumio

    2015-05-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes various toxic effects, including wasting syndrome, through activation of an aryl hydrocarbon receptor (AhR). Our previous report demonstrated that certain flavonoids inhibit the activation of AhR and suppress its DNA binding activity. In this study, we searched for an active compound among 13 flavonoids that suppressed TCDD-induced loss of lipid accumulation using 3T3-L1 adipocytes as a cell culture model for wasting syndrome. Two flavonoids, luteolin and epigallocatechin gallate, suppressed TCDD-induced loss of lipid accumulation in this model. We further investigated luteolin to clarify the underlying molecular mechanism and confirmed that luteolin inhibited nuclear translocation of AhR caused by TCDD. Luteolin also inhibited the TCDD-driven decrease in protein expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα). Although TCDD alone did not change protein expression of C/EBPβ and C/EBPδ, luteolin and TCDD up-regulated C/EBPδ expression in a dose-dependent manner. On the other hand, TCDD significantly decreased DNA binding of C/EBPβ and C/EBPδ, and luteolin completely canceled TCDD-decreased DNA binding of them. We conclude that luteolin suppresses the TCDD-induced loss of lipid accumulation in 3T3-L1 adipocytes by preventing a decrease in protein expression of PPARγ and C/EBPα, the master regulators of adipocyte differentiation and in DNA binding of C/EBPβ and C/EBPδ. Moreover, luteolin was rapidly incorporated and accumulated in 3T3-L1 adipocytes. Thus, luteolin is an attractive compound for the prevention of TCDD-induced wasting syndrome.

  18. 7-Chloroarctinone-b as a new selective PPARγ antagonist potently blocks adipocyte differentiation

    Institute of Scientific and Technical Information of China (English)

    Yong-tao LI; Li LI; Jing CHEN; Tian-cen HU; Jin HUANG; Yue-wei GUO; Hua-liang JIANG; Xu SHEN

    2009-01-01

    Aim: Peroxisome proliferator-activated receptor gamma (PPARy) is a therapeutic target for obesity, cancer and diabetes mellitus. In order to develop potent lead compounds for obesity treatment, we screened a natural product library for novel PPARy antagonists with inhibitory effects on adipocyte differentiation. Methods: Surface plasmon resonance (SPR) technology and cell-based transactivation assay were used to screen for PPARy antago-nists. To investigate the antagonistic mechanism of the active compound, we measured its effect on PPARy/RXRα heterodimerization and PPARy co-activator recruitment using yeast two-hybrid assay, Gal4/UAS cell-based assay and SPR based assay. The 3T3-L1 cell differentiation assay was used to evaluate the effect of the active compound on adipocyte differentiation. Results: A new thiophene-acetylene type of natural product, 7-chloroarctinone-b (CAB), isolated from the roots of Rhaponticum uniflo-rum, was discovered as a novel PPARγ antagonist capable of inhibiting rosiglitazone-induced PPARγ transcriptional activity. SPR analy-sis suggested that CAB bound tightly to PPARγ and considerably antagonized the potent PPARy agonist rosigtitazone-stimulated PPARγ-LBD/RXRα-LBD binding. Gal4/UAS and yeast two-hybrid assays were used to evaluate the antagonistic activity of CAB on rosiglitazone-induced recruitment of the coactivator for PPARy. CAB could efficiently antagonize both hormone and rosiglitazone-induced adipocyte differentiation in cell culture. Conclusion: CAB shows antagonistic activity to PPARγ and can block the adipocyte differentiation, indicating it may be of potential use as a lead therapeutic compound for obesity.

  19. Berberine increases adipose triglyceride lipase in 3T3-L1 adipocytes through the AMPK pathway

    OpenAIRE

    Jiang, Dongqing; Wang, Dianhui; ZHUANG, XIANGHUA; Wang, Zhanqing; Ni, Yihong; Chen, Shihong; Sun, Fudun

    2016-01-01

    Background Obesity is closely related to the metabolism of triacylglycerol (TG) in adipocytes. Adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) are rate-limiting enzymes that control the hydrolysis of TG. Effects on ATGL and HSL to increase lipolysis may counteract obesity. Berberine (BBR) is a compound derived from the Chinese medicine plant Coptis chinensis. In the present study we show the effects of BBR on ATGL and HSL and explore the potential underlying mechanisms o...

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

    Science.gov (United States)

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

    1987-01-01

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

  1. 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.

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

    Science.gov (United States)

    Leiherer, Andreas; Stoemmer, Kathrin; Muendlein, Axel; Saely, Christoph H; Kinz, Elena; Brandtner, Eva M; Fraunberger, Peter; Drexel, Heinz

    2016-05-12

    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.

  3. 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.

  4. Transcriptional activation of melanocortin 2 receptor accessory protein by PPARγ in adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Endothelial differentiation in multipotent cells derived from mouse and human white mature adipocytes.

    Science.gov (United States)

    Jumabay, Medet; Abdmaulen, Raushan; Urs, Sumithra; Heydarkhan-Hagvall, Sepideh; Chazenbalk, Gregorio D; Jordan, Maria C; Roos, Kenneth P; Yao, Yucheng; Boström, Kristina I

    2012-12-01

    White mature adipocytes give rise to multipotent cells, so-called de-differentiated fat (DFAT) cells, when losing their fat in culture. The objective of this study was to examine the ability of DFAT cells to give rise to endothelial cells (ECs) in vitro and vivo. We demonstrate that mouse and human DFAT cells, derived from adipose tissue and lipospirate, respectively, initially lack expression of CD34, CD31, CD146, CD45 and pericyte markers, distinguishing them from progenitor cells previously identified in adipose stroma. The DFAT cells spontaneously differentiate into vascular ECs in vitro, as determined by real-time PCR, fluorescence activated cell sorting, immunostaining, and formation of tube structures. Treatment with bone morphogenetic protein (BMP)4 and BMP9, important in regulating angiogenesis, significantly enhances the EC differentiation. Furthermore, adipocyte-derived cells from Green Fluorescent Protein-transgenic mice were detected in the vasculature of infarcted myocardium up to 6 weeks after ligation of the left anterior descending artery in mice. We conclude that adipocyte-derived multipotent cells are able to spontaneously give rise to ECs, a process that is promoted by BMPs and may be important in cardiovascular regeneration and in physiological and pathological changes in fat and other tissues.

  6. Adipocyte JAK2 mediates growth hormone–induced hepatic insulin resistance

    Science.gov (United States)

    Corbit, Kevin C.; Camporez, João Paulo G.; Tran, Jennifer L.; Wilson, Camella G.; Lowe, Dylan A.; Nordstrom, Sarah M.; Ganeshan, Kirthana; Perry, Rachel J.; Weiss, Ethan J.

    2017-01-01

    For nearly 100 years, growth hormone (GH) has been known to affect insulin sensitivity and risk of diabetes. However, the tissue governing the effects of GH signaling on insulin and glucose homeostasis remains unknown. Excess GH reduces fat mass and insulin sensitivity. Conversely, GH insensitivity (GHI) is associated with increased adiposity, augmented insulin sensitivity, and protection from diabetes. Here, we induce adipocyte-specific GHI through conditional deletion of Jak2 (JAK2A), an obligate transducer of GH signaling. Similar to whole-body GHI, JAK2A mice had increased adiposity and extreme insulin sensitivity. Loss of adipocyte Jak2 augmented hepatic insulin sensitivity and conferred resistance to diet-induced metabolic stress without overt changes in circulating fatty acids. While GH injections induced hepatic insulin resistance in control mice, the diabetogenic action was absent in JAK2A mice. Adipocyte GH signaling directly impinged on both adipose and hepatic insulin signal transduction. Collectively, our results show that adipose tissue governs the effects of GH on insulin and glucose homeostasis. Further, we show that JAK2 mediates liver insulin sensitivity via an extrahepatic, adipose tissue–dependent mechanism. PMID:28194444

  7. Effects of decavanadate and insulin enhancing vanadium compounds on glucose uptake in isolated rat adipocytes.

    Science.gov (United States)

    Pereira, Maria João; Carvalho, Eugénia; Eriksson, Jan W; Crans, Debbie C; Aureliano, Manuel

    2009-12-01

    The effects of different vanadium compounds namely pyridine-2,6-dicarboxylatedioxovanadium(V) (V5-dipic), bis(maltolato) oxovanadium(IV) (BMOV) and amavadine, and oligovanadates namely metavanadate and decavanadate were analysed on basal and insulin stimulated glucose uptake in rat adipocytes. Decavanadate (50 microM), manifest a higher increases (6-fold) on glucose uptake compared with basal, followed by BMOV (1 mM) and metavanadate (1 mM) solutions (3-fold) whereas V5 dipic and amavadine had no effect. Decavanadate (100 microM) also shows the highest insulin like activity when compared with the others compounds studied. In the presence of insulin (10 nM), only decavanadate increases (50%) the glucose uptake when compared with insulin stimulated glucose uptake whereas BMOV and metavanadate, had no effect and V5 dipic and amavadine prevent the stimulation to about half of the basal value. Decavanadate is also able to reduce or eradicate the suppressor effect caused by dexamethasone on glucose uptake at the level of the adipocytes. Altogether, vanadium compounds and oligovanadates with several structures and coordination spheres reveal different effects on glucose uptake in rat primary adipocytes.

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

    Science.gov (United States)

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

    2016-03-01

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

  9. TLR4-dependant pro-inflammatory effects of HMGB1 on human adipocyte.

    Science.gov (United States)

    Gunasekaran, Manoj Kumar; Virama-Latchoumy, Anne-Laurence; Girard, Anne-Claire; Planesse, Cynthia; Guérin-Dubourg, Alexis; Ottosson, Lars; Andersson, Ulf; Césari, Maya; Roche, Régis; Hoareau, Laurence

    2016-01-01

    Chronic low grade inflammation is one of the major metabolic disorders in case of obesity and associated pathologies. By its important secretion function, the role of adipose tissue in this metabolic low grade inflammation is well known. Recently, it was demonstrated that the alarmin high mobility group box protein 1 (HMGB1) is involved in obesity-related pathologies by its increased serum levels in obese compared to normal weight individuals, and by its pro-inflammatory effects. However, the role of HMGB1 on adipocytes inflammation is poorly documented and we propose to investigate this point. Primary culture of human subcutaneous adipocytes were performed from human adipose tissue samples. Cells were treated with recombinant HMGB1 with/without anti-TLR4 antibody and inhibitors of NF-κB and P38 MAPK. Supernatants were collected for IL-6 and MCP-1 ELISA. HMGB1 initiates Toll-like receptor 4 (TLR4)-dependent activation of inflammation through the downstream NF-κB and P38 MAPK signaling pathway to upregulate the secretion of the pro-inflammatory cytokine IL-6. HMGB1 has pro-inflammatory effects on adipocytes. This reinforces the role of TLR4 in adipose tissue inflammation and antagonizing the HMGB1 inflammatory pathway could bring on new therapeutic targets to counteract obesity-associated pathologies.

  10. LDL but not HDL increases adiponectin release of primary human adipocytes.

    Science.gov (United States)

    Krautbauer, Sabrina; Neumeier, Markus; Eisinger, Kristina; Hader, Yvonne; Dada, Ashraf; Schmitz, Gerd; Aslanidis, Charalampos; Buechler, Christa

    2013-12-01

    Adipocytes in obesity have inappropriately low cholesterol while adiponectin release is reduced. Cholesterol shortage may contribute to low adiponectin and 3T3-L1 cells treated with lovastatin have diminished adiponectin in cell supernatants. LDL and HDL deliver cholesterol to adipocytes. LDL but not HDL increases adiponectin in cell supernatants of primary human adipocytes. The effect of LDL is not blocked by receptor associated protein suggesting that members of the LDL-receptor family are not involved. To evaluate whether these in vitro observations translate into changes in systemic adiponectin, adiponectin was measured in serum of three patients before, immediately after and 3d after LDL-apheresis. Whereas circulating lipoproteins are reduced immediately after apheresis adiponectin is not changed. Therefore, acute lowering of lipoproteins does not affect systemic adiponectin also excluding that plenty of adiponectin is bound to lipoprotein particles. Accordingly, levels of adiponectin in purified lipoproteins are quite low. Familial hypobetalipoproteinemia (FHBL) is a rare disorder associated with low plasma LDL. Serum adiponectin is, however, similar compared to healthy controls. Thus, neither LDL nor HDL directly contributes to circulating adiponectin concentrations.

  11. CBX7 gene expression plays a negative role in adipocyte cell growth and differentiation

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    Floriana Forzati

    2014-09-01

    Full Text Available We have recently generated knockout mice for the Cbx7 gene, coding for a polycomb group protein that is downregulated in human malignant neoplasias. These mice develop liver and lung adenomas and carcinomas, which confirms a tumour suppressor role for CBX7. The CBX7 ability to downregulate CCNE1 expression likely accounts for the phenotype of the Cbx7-null mice. Unexpectedly, Cbx7-knockout mice had a higher fat tissue mass than wild-type, suggesting a role of CBX7 in adipogenesis. Consistently, we demonstrate that Cbx7-null mouse embryonic fibroblasts go towards adipocyte differentiation more efficiently than their wild-type counterparts, and this effect is Cbx7 dose-dependent. Similar results were obtained when Cbx7-null embryonic stem cells were induced to differentiate into adipocytes. Conversely, mouse embryonic fibroblasts and human adipose-derived stem cells overexpressing CBX7 show an opposite behaviour. These findings support a negative role of CBX7 in the control of adipocyte cell growth and differentiation.

  12. Characterization of VAMP isoforms in 3T3-L1 adipocytes: implications for GLUT4 trafficking.

    Science.gov (United States)

    Sadler, Jessica B A; Bryant, Nia J; Gould, Gwyn W

    2015-02-01

    The fusion of GLUT4-containing vesicles with the plasma membrane of adipocytes is a key facet of insulin action. This process is mediated by the formation of functional soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes between the plasma membrane t-SNARE complex and the vesicle v-SNARE or VAMP. The t-SNARE complex consists of Syntaxin4 and SNAP23, and whereas many studies identify VAMP2 as the v-SNARE, others suggest that either VAMP3 or VAMP8 may also fulfil this role. Here we characterized the levels of expression, distribution, and association of all the VAMPs expressed in 3T3-L1 adipocytes to provide the first systematic analysis of all members of this protein family for any cell type. Despite our finding that all VAMP isoforms form SDS-resistant SNARE complexes with Syntaxin4/SNAP23 in vitro, a combination of levels of expression (which vary by >30-fold), subcellular distribution, and coimmunoprecipitation analyses lead us to propose that VAMP2 is the major v-SNARE involved in GLUT4 trafficking to the surface of 3T3-L1 adipocytes.

  13. Ethanol Extract of Alismatis rhizome Inhibits Adipocyte Differentiation of OP9 Cells

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    Yeon-Ju Park

    2014-01-01

    Full Text Available The rhizome of Alisma orientale (Alismatis rhizome has been used in Asia for promoting diuresis to eliminate dampness from the lower-jiao and to expel heat. In this study, an ethanol extract of the rhizome of Alisma orientale (AOE was prepared and its effects on adipocyte differentiation of OP9 cells were investigated. Treatment with AOE in a differentiation medium for 5 days resulted in dose-dependent inhibition of lipid droplet formation in OP9 cells. Furthermore, AOE significantly inhibited adipocyte differentiation by downregulating the expression of the master transcription factor of adipogenesis, peroxisome proliferation-activity receptor γ (PPARγ, and related genes, including CCAAT/enhancer binding protein β (C/EBPβ, fatty acid-binding protein (aP2, and fatty acid synthase (FAS. AOE exerted its inhibitory effects primarily during the early adipogenesis stage (days 1-2, at which time it also exerted dose-dependent inhibition of the expression of C/EBPβ, a protein related to the inhibition of mitotic clonal expansion. Additionally, AOE decreased the expression of autophagy-related proteins, including beclin 1, and the autophagy-related genes, (Atg 7 and Atg12. Our results indicate that AOE’s inhibitory effects on adipocyte differentiation of OP9 cells are mediated by reduced C/EBPβ expression, causing inhibition of mitotic clonal expansion and autophagy.

  14. The Fto Gene Regulates the Proliferation and Differentiation of Pre-Adipocytes in Vitro

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    Yang Jiao

    2016-02-01

    Full Text Available The highly regulated differentiation and proliferation of pre-adipocytes play a key role in the initiation of obesity. Fat mass and obesity associated (FTO is a novel gene strongly associated with the risk of obesity. A deficiency of FTO may cause growth retardation in addition to fat mass and adipocyte size reduction in vivo. To investigate the potential role of Fto gene on the proliferation and differentiation of pre-adipocytes, we generated Fto-knockdown and overexpressed 3T3-L1 cells. Using numerous proliferation assays our results suggest that Fto knockdown leads to suppression of proliferation, lower mitochondrial membrane potential, less cellular ATP, and decreased and smaller intracellular lipid droplets compared with controls (p < 0.05. Western blot analysis demonstrated that Fto knockdown can significantly suppress peroxisome proliferator-activated receptor gamma (PPARγ and glucose transporter type 4 (GLUT4 expression and inhibit Akt phosphorylation. By contrast, overexpression of Fto had the opposing effect on proliferation, mitochondrial membrane potential, ATP generation, in vitro differentiation, Akt phosphorylation, and PPARγ and GLUT4 expression. Moreover, we demonstrated that Wortmannin, a phosphoinositide 3-kinase (PI3K inhibitor, could inhibit phospho-Akt in Fto overexpressed 3T3-L1 cells. Taken together, the results suggest that Fto regulates the proliferation and differentiation of 3T3-L1 cells via multiple mechanisms, including PPARγ and PI3K/Akt signaling.

  15. Novel adipocyte aminopeptidases are selectively upregulated by insulin in healthy and obese rats.

    Science.gov (United States)

    Alponti, Rafaela Fadoni; Alves, Patricia Lucio; Silveira, Paulo Flavio

    2016-02-01

    The lack of a complete assembly of the sensitivity of subcellular aminopeptidase (AP) activities to insulin in different pathophysiological conditions has hampered the complete view of the adipocyte metabolic pathways and its implications in these conditions. Here we investigated the influence of insulin on basic AP (APB), neutral puromycin-sensitive AP (PSA), and neutral puromycin-insensitive AP (APM) in high and low density microsomal and plasma membrane fractions from adipocytes of healthy and obese rats. Catalytic activities of these enzymes were fluorometrically monitoring in these fractions with or without insulin stimulus. Canonical traffic such as insulin-regulated AP was not detected for these novel adipocyte APs in healthy and obese rats. However, insulin increased APM in low density microsomal and plasma membrane fractions from healthy rats, APB in high density microsomal fraction from obese rats and PSA in plasma membrane fraction from healthy rats. A new concept of intracellular compartment-dependent upregulation of AP enzyme activities by insulin emerges from these data. This relatively selective regulation has pathophysiological significance, since these enzymes are well known to act as catalysts and receptor of peptides directly related to energy metabolism. Overall, the regulation of each one of these enzyme activities reflects certain dysfunction in obese individuals.

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

    DEFF Research Database (Denmark)

    Hamam, D; Ali, D; Vishnubalaji, R

    2014-01-01

    MSC, and utilized bioinformatics as well as functional and biochemical assays, and identified several novel miRNAs differentially expressed during adipogenesis. Among these, miR-320 family (miR-320a, 320b, 320c, 320d and 320e) were ~2.2-3.0-fold upregulated. Overexpression of miR-320c in hMSC enhanced adipocytic......, MIB1 (mindbomb E3 ubiquitin protein ligase 1), PAX6 (paired box 6), YWHAH and ZWILCH. siRNA-mediated silencing of those genes enhanced adipocytic differentiation of hMSC, thus corroborating an important role for those genes in miR-320c-mediated adipogenesis. Concordant with that, lentiviral......-mediated stable expression of miR-320c at physiological levels (~1.5-fold) promoted adipocytic and suppressed osteogenic differentiation of hMSC. Luciferase assay validated RUNX2 (Runt-related transcription factor 2) as a bona fide target for miR-320 family. Therefore, our data suggest miR-320 family as possible...

  17. Traditional Herbal Formula Oyaksungi-San Inhibits Adipogenesis in 3T3-L1 Adipocytes

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    Sae-Rom Yoo

    2015-01-01

    Full Text Available Background. Oyaksungi-san (OYSGS is a herbal formula that has been used for treating cardiovascular diseases in traditional Asian medicine. Here, we investigated the antiadipogenic effect of OYSGS extract in 3T3-L1 adipose cells. Methods. 3T3-L1 preadipocytes were differentiated into adipocytes with or without OYSGS. After differentiation, we measured Oil Red O staining, glycerol-3-phosphate dehydrogenase (GPDH activity, leptin production, mRNA, and protein levels of adipogenesis-related factors. Results. OYSGS extract dramatically inhibited intracellular lipid accumulation in the differentiated adipocytes. It also significantly suppressed the (GPDH activity, triglyceride (TG content, and leptin production by reducing the expression of adipogenesis-related genes including lipoprotein lipase, fatty acid binding protein 4, CCAAT/enhancer-binding protein-alpha (C/EBP-α, and peroxisome proliferator-activated receptor gamma (PPAR-γ. Furthermore, OYSGS clearly enhanced phosphorylation of AMP-activated protein kinase (AMPK as well as its substrate acetyl CoA (ACC carboxylase. Conclusions. Our results demonstrate that OYSGS negatively controls TG accumulation in 3T3-L1 adipocytes. We suggest antiadipogenic activity of OYSGS and its potential benefit in preventing obesity.

  18. Macadamia Oil Supplementation Attenuates Inflammation and Adipocyte Hypertrophy in Obese Mice

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    Edson A. Lima

    2014-01-01

    Full Text Available Excess of saturated fatty acids in the diet has been associated with obesity, leading to systemic disruption of insulin signaling, glucose intolerance, and inflammation. Macadamia oil administration has been shown to improve lipid profile in humans. We evaluated the effect of macadamia oil supplementation on insulin sensitivity, inflammation, lipid profile, and adipocyte size in high-fat diet (HF induced obesity in mice. C57BL/6 male mice (8 weeks were divided into four groups: (a control diet (CD, (b HF, (c CD supplemented with macadamia oil by gavage at 2 g/Kg of body weight, three times per week, for 12 weeks (CD + MO, and (d HF diet supplemented with macadamia oil (HF + MO. CD and HF mice were supplemented with water. HF mice showed hypercholesterolemia and decreased insulin sensitivity as also previously shown. HF induced inflammation in adipose tissue and peritoneal macrophages, as well as adipocyte hypertrophy. Macadamia oil supplementation attenuated hypertrophy of adipocytes and inflammation in the adipose tissue and macrophages.

  19. 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.

  20. 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.

  1. Altered food consumption in mice lacking lysophosphatidic acid receptor-1.

    Science.gov (United States)

    Dusaulcy, R; Daviaud, D; Pradère, J P; Grès, S; Valet, Ph; Saulnier-Blache, J S

    2009-12-01

    The release of lysophosphatidic acid (LPA) by adipocytes has previously been proposed to play a role in obesity and associated pathologies such as insulin resistance and diabetes. In the present work, the sensitivity to diet-induced obesity was studied in mice lacking one of the LPA receptor subtype (LPA1R). Conversely to what was observed in wild type (WT) mice, LPA1R-KO-mice fed a high fat diet (HFD) showed no significant increase in body weight or fat mass when compared to low fat diet (LFD). In addition, in contrast to what was observed in WT mice, LPA1R-KO mice did not exhibit over-consumption of food associated with HFD. Surprisingly, when fed a LFD, LPA1R-KO mice exhibited significant higher plasma leptin concentration and higher level of adipocyte leptin mRNA than WT mice. In conclusion, LPA1R-KO mice were found to be resistant to diet-induced obesity consecutive to a resistance to fat-induced over-consumption of food that may result at least in part from alterations in leptin expression and production.

  2. Characterization and Differentiation into Adipocytes and Myocytes of Porcine Bone Marrow Mesenchymal Stem Cells

    Institute of Scientific and Technical Information of China (English)

    DU Min-qing; WANG Song-bo; JIANG Qing-yan; HUANG Yue-qin; LU Nai-Sheng; SHU Gang; ZHU Xiao-tong; WANG Li-na; GAO Ping; XI Qian-yun; ZHANG Yong-liang

    2014-01-01

    Bone marrow mesenchymal stem cells (BMSCs) could differentiate into various cell types including adipocytes and myocytes, which had important scientiifc signiifcance not only in the ifeld of tissue regeneration, but also in the ifeld of agricultural science. In an attempt to exhibit the characterization and differentiation into adipocytes and myocytes of porcine BMSCs, we isolated and puriifed porcine BMSCs by red blood cell lysis method and percoll gradient centrifugation. The puriifed cells presented a stretched ifbroblast-like phenotype when adhered to the culture plate. The results of lfow cytometry analysis and immunofluorescence staining demonstrated that the isolated cells were positive for mesenchymal surface markers CD29, CD44 and negative for hematopoietic markers CD45 and the adhesion molecules CD31. Cells were induced to differentiate into adipocytes with adipogenic medium containing insulin, dexamethasone, oleate and octanoate. Oil Red O staining demonstrated that the porcine BMSCs successfully differentiated to adipocytes. Moreover, the ifndings of real-time PCR and Western blotting indicated that the induced cells expressed adipogenic marker genes (PPAR-γ, C/EBP-α, perilipin, aP2) mRNA or proteins (PPAR-γ, perilipin, aP2). On the other hand, porcine BMSCs were induced into myoctyes with myogenic medium supplemented with 5-azacytidine, basic ifbroblast growth factor, chick embryo extract and horse serum. Morphological observation by hochest 33342 staining showed that the induced cells presented as multi-nucleus muscular tube structure. And myogenic marker genes (Myf5, desmin) mRNA or proteins (Myf5, MyoD, myogenin, desmin) were found in the induced cells. In addition, the results of immunolfuorescence staining revealed that myogenic marker (Myf5, MyoD, myogenin, desmin, S-MyHC) proteins was positive in the induced cells. Above all, these results suggested that the isolated porcine BMSCs were not only consistent with the characterization of

  3. Resveratrol potentiates genistein's antiadipogenic and proapoptotic effects in 3T3-L1 adipocytes.

    Science.gov (United States)

    Rayalam, Srujana; Della-Fera, Mary Anne; Yang, Jeong-Yeh; Park, Hea Jin; Ambati, Suresh; Baile, Clifton A

    2007-12-01

    Genistein (G) and resveratrol (R) individually inhibit adipogenesis in 3T3-L1 adipocytes and induce apoptosis in cancer cells. We investigated whether the combination of G and R resulted in enhanced effects on adipogenesis, lipolysis, and apoptosis in 3T3-L1 cells. Preadipocytes and mature adipocytes were treated with G and R individually at 50 and 100 micromol/L (G100; R100) and in combination. Both in preadipocytes and mature adipocytes, G and R individually decreased cell viability dose-dependently, but G100 + R100 further decreased viability by 59 +/- 0.97% (P < 0.001) and 69.7 +/- 1.2% (P < 0.001) after 48 h compared with G100 and R100, respectively. G100 + R100 induced apoptosis 242 +/- 8.7% (P < 0.001) more than the control after 48 h, whereas G100 and R100 individually increased apoptosis only 46 +/- 9.2 and 46 +/- 7.9%, respectively. G and R did not modulate mitogen-activated protein kinase expression by themselves, but G100 + R100 increased Jun-N-terminal kinase phosphorylation by 38.8 +/- 4.4% (P < 0.001) and decreased extracellular signal-regulating kinase phosphorylation by 48 +/- 3.4% (P < 0.001). Individually, G and R at 25 micromol/L (G25; R25) decreased lipid accumulation by 30 +/- 1.7% and 20.07 +/- 4.27%, respectively (P < 0.001). However, G25 + R25 decreased lipid accumulation by 77.9 +/- 3.4% (P < 0.001). Lipolysis assay revealed that neither G25 nor R25 induced lipolysis, whereas G25 + R25 significantly increased lipolysis by 25.5 +/- 4.6%. The adipocyte-specific proteins PPARgamma and CCAAT/enhancer binding protein-alpha were downregulated after treatment with G + R, but no effect was observed with individual compounds. These results indicate that G and R in combination produce enhanced effects on inhibiting adipogenesis, inducing apoptosis, and promoting lipolysis in 3T3-L1 adipocytes. Thus, the combination of G and R is more potent in exerting antiobesity effects than the individual compounds.

  4. Effects of Dietary Calcium on Body Weight, Carcass Fat Content and Adipocyte Size in Male Rats

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    J Malekzadeh

    2006-07-01

    Full Text Available Introduction & Objective: Calcium is a micronutrient and now receiving much attention for its doubtful effects on weight and body fatness. A few mechanisms has been suggested for calcium effects on body fatness and the most emphasized one is the reducing of lipolysis and increasing lipogenesis via reducing parathyroid hormone levels. The present study is designed to evaluate the effects of nondairy dietary calcium on adipogenesis and adipocyte size in male Sprague dawley rats. Materials & Methods: This experimental study was done from November to September of 2005 at Tehran school of health, nutrition department. 48 male Spragu-Dawley rats from Damgostar Company were used in three randomly selected groups. The rats were fed low (0.2% W/W, usual (0.5% W/W and high (1.2% W/W dietary calcium based on AIN-93M purified diet. Rats were housed in 12 hours light-dark cycle, 22-25°C room temperature with free access to their respective diets. At the end of the experiment, rats were decapitated and carcass fat content, carcass ash content and mean adipocyte size in testis, peritoneal and subcutaneous fat pads were compared in three groups. The SPSS 11.5 was used as statistical software, running analysis of variance for comparing the effects. Results: weight gain, carcass fat content and adipocyte size, in groups were not significantly different, while serum parathyroid hormone concentrations in high calcium group was significantly lower than low calcium group (p<0.05 and insignificantly lower than usual calcium group [12.36, 23.57 and 42.2 pg/dl respectively]. Serum concentrations of 25-hydroxy cholecalciferol were also insignificantly lower in high calcium group. Conclusion: Our findings suggested that physiological concentration of dietary calcium is not effective on weight gain, body fatness and adipocyte size. Relatively equal fat content beside significant difference in serum parathyroid hormone levels is against the parathyroid theory of calcium

  5. Nuclear factor I-C reciprocally regulates adipocyte and osteoblast differentiation via control of canonical Wnt signaling.

    Science.gov (United States)

    Zhou, Jie; Wang, Shan; Qi, Qi; Yang, Xiaoyue; Zhu, Endong; Yuan, Hairui; Li, Xuemei; Liu, Ying; Li, Xiaoxia; Wang, Baoli

    2017-01-25

    Nuclear factor I-C (NFIC) has recently been identified as an important player in osteogenesis and bone homeostasis in vivo However, the molecular mechanisms involved have yet to be defined. In the current study, Nfic expression was altered in primary marrow stromal cells and established progenitor lines after adipogenic and osteogenic treatment. Overexpression of Nfic in stromal cells ST2, mesenchymal cells C3H10T1/2, and primary marrow stromal cells inhibited adipogenic differentiation, whereas it promoted osteogenic differentiation. Conversely, silencing of endogenous Nfic in the cell lines enhanced adipogenic differentiation, whereas it blocked osteogenic differentiation. Mechanism investigations revealed that Nfic overexpression promoted nuclear translocation of β-catenin and increased nuclear protein levels of β-catenin and transcription factor 7-like 2 (TCF7L2). Promoter studies and the chromatin immunoprecipitation (ChIP) assay revealed that NFIC directly binds to the promoter of low-density lipoprotein receptor-related protein 5 (Lrp5) and thereafter transactivates the promoter. Finally, inactivation of canonical Wnt signaling in ST2 attenuated the inhibition of adipogenic differentiation and stimulation of osteogenic differentiation by NFIC. Our study suggests that NFIC balances adipogenic and osteogenic differentiation from progenitor cells through controlling canonical Wnt signaling and highlights the potential of NFIC as a target for new therapies to control metabolic disorders like osteoporosis and obesity.-Zhou, J., Wang, S., Qi, Q., Yang, X., Zhu, E., Yuan, H., Li, X., Liu, Y., Li, X., Wang, B. Nuclear factor I-C reciprocally regulates adipocyte and osteoblast differentiation via control of canonical Wnt signaling.

  6. Effects of fatty acid regulation on visfatin gene expression in adipocytes

    Institute of Scientific and Technical Information of China (English)

    WEN Yu; WANG Hong-wei; WU Jing; LU Hui-ling; HU Xiu-fen; Katherine Cianflone

    2006-01-01

    Background The levels of long-term elevated serum or intracellular free fatty acid (FFA) induce insulin resistance associated with central obesity. The insulin-mimetic protein visfatin is preferentially produced by visceral adipose tissues and has been implicated in obesity and insulin resistance. To identify that FFA is capable of inducing insulin resistance and to clarify the role of FFA on visfatin, we examined the effect of monounsaturated FFA oleate (C18:1) and saturated FFA palmitate (C16:0) on glucose transport and visfatin gene expression in cultured 3T3-L1 adipocytes or preadipocytes.Methods FFA-free DMEM/F12, 0.125 mmol/L, 0.5 mmol/1 and 1.0 mmol/L oleate or palmitate was added to cultured 3T3-L1 adipocytes or preadipocytes and incubated overnight. Glucose transport was assessed as 3H-2-deoxy-glucose uptake. Total RNA was extracted and subjected to RT-PCR for the measurement of visfatin mRNA levels. Statistical comparisons between control group and other groups were performed with the two-tailed paired t test, and one-way ANOVA was used to compare the mean values among the groups.Results Insulin increased specific membrane glucose transport in 3T3-L1 preadipocytes. Upregulation was evident from 15 minutes to 1 hour exposure to insulin. However, after 6-hour exposure to insulin, there was a downregulation in the response to insulin. Dose response studies demonstrated that 2-deoxy glucose transport was increased by 336% at 50 nmol/L insulin (P<0.01), and reached a maximal effect at 100 nmol/L insulin(P<0.01). Oleate and palmitate treatment did not influence basal glucose transport (without insulin stimulation),whereas insulin-stimulated glucose transport was inhibited after overnight oleate and palmitate treatment in preadipocytes and adipocytes. In 3T3-L1 preadipocytes, insulin resistance could be achieved at 0.125 mmol/L oleate or palmitate (P<0.05, respectively), and the inhibition was dose dependent. In adipocytes, the inhibition was noted at 0

  7. 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.

  8. Loss of CD24 in Mice Leads to Metabolic Dysfunctions and a Reduction in White Adipocyte Tissue.

    Directory of Open Access Journals (Sweden)

    Nicholas A Fairbridge

    Full Text Available CD24 is a glycophosphatidylinositol (GPI-linked cell surface receptor that is involved in regulating the survival or differentiation of several different cell types. CD24 has been used to identify pre-adipocytes that are able to reconstitute white adipose tissue (WAT in vivo. Moreover, we recently found that the dynamic upregulation of CD24 in vitro during early phases of adipogenesis is necessary for mature adipocyte development. To determine the role of CD24 in adipocyte development in vivo, we evaluated the development of the inguinal and interscapular subcutaneous WAT and the epididymal visceral WAT in mice with a homozygous deletion of CD24 (CD24KO. We observed a significant decrease in WAT mass of 40% to 74% in WAT mass from both visceral and subcutaneous depots in male mice, with no significant effect in female mice, compared to wild-type (WT sex- and age-matched controls. We also found that CD24KO mice had increased fasting glucose and free fatty acids, decreased fasting insulin, and plasma leptin. No major differences were observed in the sensitivity to insulin or glucose, or in circulating triglycerides, total cholesterol, HDL-cholesterol, or LDL-cholesterol levels between WT and CD24KO mice. Challenging the CD24KO mice with either high sucrose (35% or high fat (45% diets that promote increased adiposity, increased WAT mass and fasting insulin, adiponectin and leptin levels, as well as reduced the sensitivity to insulin and glucose, to the levels of WT mice on the same diets. The CD24-mediated reduction in fat pad size was due to a reduction in adipocyte cell size in all depots with no significant reduction pre-adipocyte or adipocyte cell number. Thus, we have clearly demonstrated that the global absence of CD24 affects adipocyte cell size in vivo in a sex- and diet-dependent manner, as well as causing metabolic disturbances in glucose homeostasis and free fatty acid levels.

  9. Adipocyte (Pro)Renin-Receptor Deficiency Induces Lipodystrophy, Liver Steatosis and Increases Blood Pressure in Male Mice.

    Science.gov (United States)

    Wu, Chia-Hua; Mohammadmoradi, Shayan; Thompson, Joel; Su, Wen; Gong, Ming; Nguyen, Genevieve; Yiannikouris, Frédérique

    2016-07-01

    Adipose tissue dysfunction related to obesity is overwhelmingly associated with increased risk of developing cardiovascular diseases. In the setting of obesity, (pro)renin receptor (PRR) is increased in adipose tissue of mice. We sought to determine the physiological consequences of adipocyte-PRR deficiency using adiponectin-Cre mice. We report a unique model of adipocyte-PRR-deficient mice (PRR(Adi/Y)) with almost no detectable white adipose tissues. As a consequence, the livers of PRR(Adi/Y) mice were enlarged and demonstrated a marked accumulation of lipids. Adipocyte-specific deficiency of PRR increased systolic blood pressure and the concentration of soluble PRR in plasma. To determine whether adipocyte-PRR was involved in the development of obesity-induced hypertension, mice were fed a low-fat or a high-fat diet for 16 weeks. Adipocyte-PRR-deficient mice were resistant to diet-induced obesity. Both high-fat- and low-fat-fed PRR(Adi/Y) mice had elevated insulin levels. Interestingly, adipocyte-PRR deficiency improved glucose tolerance in high-fat-fed PRR(Adi/Y) mice. In response to feeding either low-fat or high-fat diets, systolic blood pressure was greater in PRR(Adi/Y) mice than in control mice. High-fat feeding elevated soluble PRR concentration in control and PRR(Adi/Y) mice. In vitro knockdown of PRR by siRNA significantly decreased mRNA abundance of PPARγ (peroxisome proliferator-activated receptor gamma), suggesting an important role for PRR in adipogenesis. Our data indicate that adipocyte-PRR is involved in lipid homeostasis and glucose and insulin homeostasis, and that soluble PRR may be a predictor of metabolic disturbances and play a role in systolic blood pressure regulation.

  10. Phytic acid and myo-inositol support adipocyte differentiation and improve insulin sensitivity in 3T3-L1 cells.

    Science.gov (United States)

    Kim, Jin Nam; Han, Sung Nim; Kim, Hye-Kyeong

    2014-08-01

    Phytic acid, also known as myo-inositol hexaphosphate, has been shown to lower blood glucose levels and to improve insulin sensitivity in rodents. We investigated the effects of phytic acid and myo-inositol on differentiation, insulin-stimulated glucose uptake, and lipolysis of adipocytes to test the hypothesis that the antidiabetic properties of phytic acid and myo-inositol are mediated directly through adipocytes. 3T3-L1 cells were treated with 10, 50, or 200 μmol/L of phytic acid or myo-inositol. Oil Red O staining and an intracellular triacylglycerol assay were used to determine lipid accumulation during adipocyte differentiation. Immunoblotting and real-time polymerase chain reaction (PCR) were performed to evaluate expression of transcription factors, a target protein, and insulin signaling molecules. Phytic acid and myo-inositol exposures increased lipid accumulation in a dose-dependent manner (P acid synthase increased upon treatments with phytic acid and myo-inositol (P phytic acid and myo-inositol treatments (P phytic acid and myo-inositol treatments. In fully differentiated adipocytes, phytic acid and myo-inositol reduced basal lipolysis dose dependently (P phytic acid and myo-inositol increase insulin sensitivity in adipocytes by increasing lipid storage capacity, improving glucose uptake, and inhibiting lipolysis.

  11. Saturated Fatty Acid Induces Insulin Resistance Partially Through Nucleotide-binding Oligomerization Domain 1 Signaling Pathway in Adipocytes

    Institute of Scientific and Technical Information of China (English)

    Yi-jun Zhou; Yin-si Tang; Yu-ling Song; Ai Li; Hui Zhou; Yan Li

    2013-01-01

    Objective To investigate the potential role of nucleotide-binding oligomerization domain 1 (NOD1), a component of the innate immune system, in mediating lipid-induced insulin resistance in adipocytes. Methods Adipocytes from Toll-like receptor 4 deficiency mice were used for stimulation experiments. The effect of oleate/palmitate mixture on nuclear factor-κB (NF-κB) activation was analyzed by reporter plasmid assay. The release of proinflammatory chemokine/cytokines production was determined by using real-time PCR. Insulin-stimulated glucose uptake was measured by 2-deoxy-D-[3H] glucose uptake assay. Chemokine/cytokine expression and glucose uptake in adipocytes transfected with small interfering RNA (siRNA) targeting NOD1 upon fatty acids treatment were analyzed. Results Oleate/palmitate mixture activated the NF-κB pathway and induced interleukin-6, tumor necrosis factor-α, and monocyte chemoattractant protein-1 mRNA expressions in adipocytes from mice deficient in Toll-like receptor 4, and these effects were blocked by siRNA targeting NOD1. Furthermore, saturated fatty acids decreased the ability of insulin-stimulated glucose uptake. Importantly, siRNA targeting NOD1 partially reversed saturated fatty acid-induced suppression of insulin-induced glucose uptake. Conclusion NOD1 might play an important role in saturated fatty acid-induced insulin resistance in adipocytes, suggesting a mechanism by which reduced NOD1 activity confers beneficial effects on insulin action.

  12. MicroRNA profiling links miR-378 to enhanced adipocyte lipolysis in human cancer cachexia.

    Science.gov (United States)

    Kulyté, Agné; Lorente-Cebrián, Silvia; Gao, Hui; Mejhert, Niklas; Agustsson, Thorhallur; Arner, Peter; Rydén, Mikael; Dahlman, Ingrid

    2014-02-01

    Cancer cachexia is associated with pronounced adipose tissue loss due to, at least in part, increased fat cell lipolysis. MicroRNAs (miRNAs) have recently been implicated in controlling several aspects of adipocyte function. To gain insight into the possible impact of miRNAs on adipose lipolysis in cancer cachexia, global miRNA expression was explored in abdominal subcutaneous adipose tissue from gastrointestinal cancer patients with (n = 10) or without (n = 11) cachexia. Effects of miRNA overexpression or inhibition on lipolysis were determined in human in vitro differentiated adipocytes. Out of 116 miRNAs present in adipose tissue, five displayed distinct cachexia-associated expression according to both microarray and RT-qPCR. Four (miR-483-5p/-23a/-744/-99b) were downregulated, whereas one (miR-378) was significantly upregulated in cachexia. Adipose expression of miR-378 associated strongly and positively with catecholamine-stimulated lipolysis in adipocytes. This correlation is most probably causal because overexpression of miR-378 in human adipocytes increased catecholamine-stimulated lipolysis. In addition, inhibition of miR-378 expression attenuated stimulated lipolysis and reduced the expression of LIPE, PLIN1, and PNPLA2, a set of genes encoding key lipolytic regulators. Taken together, increased miR-378 expression could play an etiological role in cancer cachexia-associated adipose tissue loss via effects on adipocyte lipolysis.

  13. 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.

  14. High-fat diet feeding alters metabolic response to fasting/non fasting conditions. Effect on caveolin expression and insulin signalling

    Directory of Open Access Journals (Sweden)

    Martínez J Alfredo

    2011-04-01

    Full Text Available Abstract Background The effect of food intake on caveolin expression in relation to insulin signalling was studied in skeletal muscle and adipocytes from retroperitoneal (RP and subcutaneous (SC adipose tissue, comparing fasted (F to not fasted (NF rats that had been fed a control or high-fat (HF diet for 72 days. Methods Serum glucose was analysed enzymatically and insulin and leptin by ELISA. Caveolins and insulin signalling intermediaries (IR, IRS-1 and 2 and GLUT4 were determined by RT-PCR and western blotting. Caveolin and IR phosphorylation was measured by immunoprecipitation. Data were analysed with Mann-Whitney U test. Results High-fat fed animals showed metabolic alterations and developed obesity and insulin resistance. In skeletal muscle, food intake (NF induced activation of IR and increased expression of IRS-2 in control animals with normal metabolic response. HF animals became overweight, hyperglycaemic, hyperinsulinemic, hyperleptinemic and showed insulin resistance. In skeletal muscle of these animals, food intake (NF also induced IRS-2 expression together with IR, although this was not active. Caveolin 3 expression in this tissue was increased by food intake (NF in animals fed either diet. In RP adipocytes of control animals, food intake (NF decreased IR and IRS-2 expression but increased that of GLUT4. A similar but less intense response was found in SC adipocytes. Food intake (NF did not change caveolin expression in RP adipocytes with either diet, but in SC adipocytes of HF animals a reduction was observed. Food intake (NF decreased caveolin-1 phosphorylation in RP but increased it in SC adipocytes of control animals, whereas it increased caveolin-2 phosphorylation in both types of adipocytes independently of the diet. Conclusions Animals fed a control-diet show a normal response to food intake (NF, with activation of the insulin signalling pathway but without appreciable changes in caveolin expression, except a small increase

  15. The adipocyte as an endocrine organ in the regulation of metabolic homeostasis.

    Science.gov (United States)

    Harwood, H James

    2012-07-01

    Over the past decade and a half it has become increasingly clear that adipose tissue is a much more complex organ than was initially considered and that its metabolic functions extend well beyond the classical actions of thermoregulation and of storage and release of fatty acids. In fact, it is now well established that adipose tissue plays a critical role in maintenance of energy homeostasis through secretion of a large number of adipokines that interact with central as well as peripheral organs such as the brain, liver, pancreas, and skeletal muscle to control diverse processes, such as food intake, energy expenditure, carbohydrate and lipid metabolism, blood pressure, blood coagulation, and inflammation. While many of these adipokines are adipocyte-derived and have a variety of endocrine functions, others are produced by resident macrophages and interact in a paracrine fashion to control adipocyte metabolism. It is also abundantly clear that the dysregulation of adipokine secretion and action that occurs in obesity plays a fundamental role in the development of a variety of cardiometabolic disorders, including the metabolic syndrome, type 2 diabetes, inflammatory disorders, and vascular disorders, that ultimately lead to coronary heart disease. Described herein are the traditional as well as endocrine roles of adipose tissue in controlling energy metabolism and their dysregulation in obesity that leads to development of cardiometabolic disorders, with a focus on what is currently known regarding the characteristics and roles in both health and disease of the adipocyte-derived adipokines, adiponectin, leptin, resistin, and retinol binding protein 4, and the resident macrophage-derived adipokines, tumor necrosis factor-α and interleukin-6. This article is part of a Special Issue entitled 'Central Control of Food Intake'.

  16. Characterisation of adipocyte-derived extracellular vesicles released pre- and post-adipogenesis

    Directory of Open Access Journals (Sweden)

    Katherine D. Connolly

    2015-11-01

    Full Text Available Extracellular vesicles (EVs are submicron vesicles released from many cell types, including adipocytes. EVs are implicated in the pathogenesis of obesity-driven cardiovascular disease, although the characteristics of adipocyte-derived EVs are not well described. We sought to define the characteristics of adipocyte-derived EVs before and after adipogenesis, hypothesising that adipogenesis would affect EV structure, molecular composition and function. Using 3T3-L1 cells, EVs were harvested at day 0 and day 15 of differentiation. EV and cell preparations were visualised by electron microscopy and EVs quantified by nanoparticle tracking analysis (NTA. EVs were then assessed for annexin V positivity using flow cytometry; lipid and phospholipid composition using 2D thin layer chromatography and gas chromatography; and vesicular protein content by an immuno-phenotyping assay. Pre-adipogenic cells are connected via a network of protrusions and EVs at both time points display classic EV morphology. EV concentration is elevated prior to adipogenesis, particularly in exosomes and small microvesicles. Parent cells contain higher proportions of phosphatidylserine (PS and show higher annexin V binding. Both cells and EVs contain an increased proportion of arachidonic acid at day 0. PREF-1 was increased at day 0 whilst adiponectin was higher at day 15 indicating EV protein content reflects the stage of adipogenesis of the cell. Our data suggest that EV production is higher in cells before adipogenesis, particularly in vesicles <300 nm. Cells at this time point possess a greater proportion of PS (required for EV generation whilst corresponding EVs are enriched in signalling fatty acids, such as arachidonic acid, and markers of adipogenesis, such as PREF-1 and PPARγ.

  17. Myristic Acid (MA) Promotes Adipogenic Gene Expression and the Differentiation of Porcine Intramuscular Adipocyte Precursor Cells

    Institute of Scientific and Technical Information of China (English)

    LU Nai-sheng; ZHANG Yong-liang; JIANG Qing-yan; SHU Gang; XIE Qiu-ping; ZHU Xiao-tong; GAO Ping; ZHOU Gui-xuan; WANG Song-bo; WANG Li-na; XI Qian-yun

    2014-01-01

    Intramuscular fat (IMF) content is considered to be a key factor that affects the marbling, tenderness, juiciness and lfavor of pork. To investigate the effects of myristic acid (MA) on the differentiation of porcine intramuscular adipocytes, cells were isolated from longissimus dorsi muscle (LDM) and treated with 0, 10, 50 or 100μmol L-1 MA. The results showed that MA signiifcantly promotes the differentiation of intramuscular adipocytes in a dose-dependent manner. MA also led to a parallel increase in the expression of peroxisome proliferator activated receptor-γ(PPARγ) and adipose-related genes, such as glucose transporter 1 (GLUT1), lipoprotein lipase (LPL), adipocyte fatty acid binding protein 4 (FABP4/aP2), fatty acid translocase (FAT), acetyl-CoA carboxylaseα(ACCα), adipose triglyceride lipase (ATGL) and fatty acid synthase (FASN). However, no signiifcant effects of MA were observed on the expression of CAAT enhancer binding protein-α(C/EBPα) or hormone sensitive lipase (HSL). The expression of pyruvate dehydrogenase kinase 4 (PDK4) was increased by MA during the early stages of differentiation (day 1-3). In addition, MA also increased the absolute content of C14 (P<0.001) and saturated fatty acids (SFA) (P<0.05) to varying degrees, but no effects were observed on other fatty acids. These results suggest that MA might be able to enhance the IMF content of pork and increase the accumulation of myristic and myristoleic acid in muscle, which might have beneifcial implications for human health.

  18. 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.

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

    Science.gov (United States)

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

    2001-03-01

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

  20. Berberine activates GLUT1-mediated glucose uptake in 3T3-L1 adipocytes.

    Science.gov (United States)

    Kim, So Hui; Shin, Eun-Jung; Kim, Eun-Do; Bayaraa, Tsenguun; Frost, Susan Cooke; Hyun, Chang-Kee

    2007-11-01

    It has recently been known that berberine, an alkaloid of medicinal plants, has anti-hyperglycemic effects. To explore the mechanism underlying this effect, we used 3T3-L1 adipocytes for analyzing the signaling pathways that contribute to glucose transport. Treatment of berberine to 3T3-L1 adipocytes for 6 h enhanced basal glucose uptake both in normal and in insulin-resistant state, but the insulin-stimulated glucose uptake was not augmented significantly. Inhibition of phosphatidylinositol 3-kinase (PI 3-K) by wortmannin did not affect the berberine effect on basal glucose uptake. Berberine did not augment tyrosine phosphorylation of insulin receptor (IR) and insulin receptor substrate (IRS)-1. Further, berberine had no effect on the activity of the insulin-sensitive downstream kinase, atypical protein kinase C (PKCzeta/lambda). However, interestingly, extracellular signal-regulated kinases (ERKs), which have been known to be responsible for the expression of glucose transporter (GLUT)1, were significantly activated in berberine-treated 3T3-L1 cells. As expected, the level of GLUT1 protein was increased both in normal and insulin-resistant cells in response to berberine. But berberine affected the expression of GLUT4 neither in normal nor in insulin-resistant cells. In addition, berberine treatment increased AMP-activated protein kinase (AMPK) activity in 3T3-L1 cells, which has been reported to be associated with GLUT1-mediated glucose uptake. Together, we concluded that berberine increases glucose transport activity of 3T3-L1 adipocytes by enhancing GLUT1 expression and also stimulates the GLUT1-mediated glucose uptake by activating GLUT1, a result of AMPK stimulation.

  1. Curcumin, a Potential Inhibitor of Up-regulation of TNF-alpha and IL-6 Induced by Palmitate in 3T3-L1 Adipocytes through NF-kappaB and JNK Pathway

    Institute of Scientific and Technical Information of China (English)

    SHAO-LING WANG; YING EI; YING WEN; YAN-FENG CHEN; LI-XIN NA; SONG-TAO LI; CHANG-HAO SUN

    2009-01-01

    Objective To investigate the attenuating effect of curcumin, an anti-inflammatory compound derived from dietary spice turmeric (Curcuma longa) on the pro-inflammatory insulin-resistant state in 3T3-L1 adipocytes. Methods Glucose uptake rate was determined with the [3H] 2-deoxyglucose uptake method. Expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by quantitative RT-PCR analysis and ELISA. Nuclear transcription factor kappaB p65 (NF-κB p65) and mitogen-activated protein kinase (MAPKs) were detected by Western blot assay. Results The basal glucose uptake was not altered, and curcumin increased the insulin-stimulated glucose uptake in 3T3-L1 cells. Curcumin suppressed the transcription and secretion of TNF-α and IL-6 induced by palmitate in a concentration-dependent manner. Palmitate induced nuclear translocation of NF-kB. The activities of Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase1/2 (ERK1/2) and p38MAPK decreased in the presence of curcumin. Moreover, pretreatment with SP600125 (inhibitor of JNK) instead of PD98059 or SB203580 (inhibitor of ERK 1/2 or p38MAPK, respectively) decreased the up-regulation of TNF-α induced by palmitate. Conclusion Curcumin reverses palmitate-induced insulin resistance state in 3T3-L1 adipocytes through the NF-kB and JNK pathway.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  3. MDM2 facilitates adipocyte differentiation through CRTC-mediated activation of STAT3

    DEFF Research Database (Denmark)

    Hallenborg, P.; Siersbæk, M.; Barrio-Hernandez, I.

    2016-01-01

    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...... 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...

  4. ELMOD2 is anchored to lipid droplets by palmitoylation and regulates adipocyte triglyceride lipase recruitment

    DEFF Research Database (Denmark)

    Suzuki, Michitaka; Murakami, Tatsuro; Cheng, Jinglei

    2015-01-01

    Adipocyte triglyceride lipase (ATGL) is the major enzyme involved in the hydrolysis of triglycerides. The Arf1-coat protein complex I (COPI) machinery is known to be engaged in the recruitment of ATGL to lipid droplets (LDs), but the regulatory mechanism has not been clarified. In the present study...... cellular triglycerides. These effects of ELMOD2 knockdown were canceled by transfection of small interfering RNA-resistant cDNA of wild-type ELMOD2 but not by that of mutated ELMOD2 lacking the Arf-GAP activity. ELMOD2 was distributed in the endoplasmic reticulum and mitochondria as well as in LDs...

  5. ELMOD2 is anchored to lipid droplets by palmitoylation and regulates adipocyte triglyceride lipase recruitment

    OpenAIRE

    Suzuki, Michitaka; Murakami, Tatsuro; Cheng, Jinglei; Kano, Hiroyuki; Fukata, Masaki; Fujimoto, Toyoshi

    2015-01-01

    Adipocyte triglyceride lipase (ATGL) is the major enzyme involved in the hydrolysis of triglycerides. The Arf1–coat protein complex I (COPI) machinery is known to be engaged in the recruitment of ATGL to lipid droplets (LDs), but the regulatory mechanism has not been clarified. In the present study, we found that ELMOD2, a putative noncanonical Arf–GTPase activating protein (GAP) localizing in LDs, plays an important role in controlling ATGL transport to LDs. We showed that knockdown of ELMOD...

  6. 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

    inclusions was observed. The effect of hypoxia on the expression of adipocyte-specific genes was determined by real-time reverse transcription polymerase chain reaction. Interestingly, neither of the two central regulators of adipogenesis--the transcription factors peroxisome proliferator-activated receptor......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...

  7. Activation of AMPK by berberine promotes adiponectin multimerization in 3T3-L1 adipocytes.

    Science.gov (United States)

    Li, Yun; Wang, Pengcheng; Zhuang, Yuan; Lin, Huan; Li, Yehua; Liu, Ling; Meng, Qinghang; Cui, Ting; Liu, Jing; Li, Zhen

    2011-06-23

    Adiponectin is assembled into trimer (LMW), hexamer (MMW) and high-molecular-weight (HMW) multimer in adipocytes. The HMW adiponectin is more metabolically active and closely associated with peripheral insulin sensitivity. In this study, we reported that berberine, an isoquinoline alkaloid with insulin-sensitizing effect, inhibits the expression of adiponectin, but promotes the assembly of HMW adiponectin and increases the ratio of HMW to total adiponectin. Berberine activates AMPK. Knockdown of AMPKα1 abolishes the effect of berberine. Activation of AMPK by AICAR also increases the level of HMW adiponectin. Our study suggested that activation of AMPK by berberine promotes adiponectin multimerization.

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

    DEFF Research Database (Denmark)

    Björk, Christel; Wilhelm, Uta; Mandrup, Susanne

    2016-01-01

    bioactive nutrients on fat metabolism, we investigated their role on human white adipocyte function. METHODS: The influence of the omega-3-fatty acid docosahexaenoic acid (DHA), the anthocyanin (AC) cyanidin-3-glucoside and its metabolite protocatechuic acid, and the beta-glucan metabolite propionic acid...... of the compounds was found to be cytotoxic. CONCLUSION: The studied bioactive food compounds or their metabolites have beneficial effects in human primary fat cells measured as decreased basal lipolytic activity and secretion of inflammatory markers. A minor effect was also observed on insulin-stimulated glucose...

  9. 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

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

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  11. 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...... is higher in obesity-prone C57BL/6 mice than obesity-resistant 129 mice, and the number in both depots is increased by up to 270% by exposure of mice to high-fat diet. Thus, APCs from visceral and subcutaneous depots are dynamic populations, which have intrinsic differences in gene expression...

  12. 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

    , CD1d-restricted invariant (i)Natural Killer T (NKT) cells, a unique subset of lymphocytes that are reactive to so called lipid antigens, were implicated in AT homeostasis. Interestingly, recent data also suggest that human and mouse adipocytes can present such lipid antigens to iNKT cells in a CD1d...... 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.......-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...

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

    DEFF Research Database (Denmark)

    Ali; Hamam; Alfayez;

    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...... or stromal) stem cells (hMSCs). These data provide new insight into the understanding of the relationship between the epigenetic effect of histone deacetylase inhibitors, transcription factors, and differentiation pathways controlling adipocyte and osteoblast differentiation of hMSCs. Manipulating...

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

    Science.gov (United States)

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

    2013-08-01

    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.

  15. Cultured 3T3L1 adipocytes dispose of excess medium glucose as lactate under abundant oxygen availability

    Science.gov (United States)

    Sabater, David; Arriarán, Sofía; Romero, María Del Mar; Agnelli, Silvia; Remesar, Xavier; Fernández-López, José Antonio; Alemany, Marià

    2014-01-01

    White adipose tissue (WAT) produces lactate in significant amount from circulating glucose, especially in obesity;Under normoxia, 3T3L1 cells secrete large quantities of lactate to the medium, again at the expense of glucose and proportionally to its levels. Most of the glucose was converted to lactate with only part of it being used to synthesize fat. Cultured adipocytes were largely anaerobic, but this was not a Warburg-like process. It is speculated that the massive production of lactate, is a process of defense of the adipocyte, used to dispose of excess glucose. This way, the adipocyte exports glucose carbon (and reduces the problem of excess substrate availability) to the liver, but the process may be also a mechanism of short-term control of hyperglycemia. The in vivo data obtained from adipose tissue of male rats agree with this interpretation.

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

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  17. FTO Obesity Risk Variants Are Linked to Adipocyte IRX3 Expression and BMI of Children - Relevance of FTO Variants to Defend Body Weight in Lean Children?

    Science.gov (United States)

    Landgraf, Kathrin; Scholz, Markus; Kovacs, Peter; Kiess, Wieland; Körner, Antje

    2016-01-01

    Background Genome-wide association studies have identified variants within the FTO (fat mass and obesity associated) locus as the strongest predictors of obesity amongst all obesity-associated gene loci. Recent evidence suggests that variants in FTO directly affect human adipocyte function through targeting IRX3 and IRX5 and thermogenesis regulation. Aim We addressed the relevance of this proposed FTO-IRX pathway in adipose tissue (AT) of children. Results Expression of IRX3 was higher in adipocytes compared to SVF. We found increased adipocyte-specific expression of IRX3 and IRX5 with the presence of the FTO risk haplotype in lean children, whereas it was unaffected by risk variants in obese peers. We further show that IRX3 expression was elevated in isolated adipocytes and AT of lean compared to obese children, particularly in UCP1-negative adipocytes, and inversely correlated with BMI SDS. Independent of BMI, IRX3 expression in adipocytes was significantly related to adipocyte hypertrophy, and subsequent associations with AT inflammation and HOMA-IR in the children. Conclusion One interpretation of our observation of FTO risk variants linked to IRX3 expression and adipocyte size restricted to lean children, along with the decreased IRX3 expression in obese compared to lean peers, may reflect a defense mechanism for protecting body-weight, which is pertinent for lean children. PMID:27560134

  18. [Altered states of consciousness].

    Science.gov (United States)

    Gora, E P

    2005-01-01

    The review of modern ideas concerning the altered states of consciousness is presented in this article. Various methods of entry into the altered states of consciousness are looked over. It is shown that the altered states of consciousness are insufficiently known, but important aspects of human being existence. The role of investigation of the altered states of consciousness for the creation of integrative scientific conception base is discussed.

  19. 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.

  20. Fatty acids do not pay the toll: effect of SFA and PUFA on human adipose tissue and mature adipocytes inflammation

    Directory of Open Access Journals (Sweden)

    Murumalla Ravi Kumar

    2012-12-01

    Full Text Available Abstract Background On the basis that high fat diet induces inflammation in adipose tissue, we wanted to test the effect of dietary saturated and polysunsaturated fatty acids on human adipose tissue and adipocytes inflammation. Moreover we wanted to determine if TLR2 and TLR4 are involved in this pathway. Methods Human adipose tissue and adipocytes primary cultures were treated with endotoxin-free BSA conjugated with SFA (lauric acid and palmitic acid - LA and PA and PUFA (eicosapentaeneic acid, docosahexaenoic acid and oleic acid - EPA, DHA and OA with or without LPS. Cytokines were then assayed by ELISA (TNF-alpha, IL-6 and MCP-1. In order to determine if TLR2 and TLR4 are activated by fatty acid (FA, we used HEK-Blue cells transfected by genes from TLR2 or TLR4 pathways associated with secreted alkaline phosphatase reporter gene. Results None of the FA tested in HEK-Blue cells were able to activate TLR2 or TLR4, which is concordant with the fact that after FA treatment, adipose tissue and adipocytes cytokines levels remain the same as controls. However, all the PUFA tested: DHA, EPA and to a lesser extent OA down-regulated TNF-alpha, IL-6 and MCP-1 secretion in human adipose tissue and adipocytes cultures. Conclusions This study first confirms that FA do not activate TLR2 and TLR4. Moreover by using endotoxin-free BSA, both SFA and PUFA tested were not proinflammatory in human adipose tissue and adipocytes model. More interestingly we showed that some PUFA exert an anti-inflammatory action in human adipose tissue and adipocytes model. These results are important since they clarify the relationship between dietary fatty acids and inflammation linked to obesity.

  1. In vitro study of the effect of diesterified alkoxyglycerols with conjugated linoleic acid on adipocyte inflammatory mediators

    Directory of Open Access Journals (Sweden)

    Reglero Guillermo

    2010-04-01

    Full Text Available Abstract Background Adipocytes contribute to inflammation and the innate immune response through expression of inflammatory mediators. High levels of these mediators have been related to chronic inflammation state and insulin resistance, cardiovascular diseases and diabetes type 2, among other disorders. 3-octadecylglycerol (batyl alcohol has been described as an inflammatory agent, whereas Conjugated Linoleic Acid (CLA is considered effective against obesity. In this study we examined the anti-inflammatory activity and mechanisms of modified alkoxyglycerols. Tumor necrosis factor (TNF-α activated mature adipocytes were used as cellular model of inflammation. Secreted levels and gene expressions of some inflammatory mediators, such as the adipokines, interleukin (IL-1β, IL-6 and IL-10; and the levels of leptin and adiponectin hormones were quantified in presence and absence of alkoxyglycerols and when human adipocyte cells were or not activated by TNF-α. The aim of this study is to describe the effects of nonesterified alkoxyglycerols, CLA and diesterified alkoxyglycerols with CLA (DEA-CLA and check if they present beneficial properties using an in vitro model of some chronic diseases related to the inflammatory process, such as obesity, using human mature adipocytes activated with TNF-α. Results Our data suggest that DEA-CLA, product of the esterification between the CLA and batyl alcohol, present beneficial effects on adipocytes close to observed and described for CLA (i.e. decrease of IL-1β and no adverse effects as observed for batyl alcohol (i.e. decrease of IL-10. In addition, DEA-CLA presented similar activity to CLA showing a trend to increase the secreted levels of adiponectin and decreasing the secreted levels of leptin. Conclusions CLA and DEA-CLA modify adipocyte inflammatory mediators and also could play a role on energy homeostasis through depletion of leptin levels.

  2. Berberine reverses free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM:To investigate the effects and molecular mechanisms of berberine on improving insulin resistance induced by free fatty acids (FFAs) in 3T3-LI adipocytes.METHODS:The model of insulin resistance in 3T3-L1 adipocytes was established by adding palmic acid (0.5 mmol/L) to the culture medium.Berberine treatment was performed at the same time.Glucose uptake rate was determined by the 2-deoxy-[3H]-Dglucose method.The levels of IkB kinase beta (IKKβ)Ser181 phosphorylation,insulin receptor substrate1(IRS-1) Ser307 phosphorylation,expression of IKKβ,IRS-1,nuclear transcription factor kappaB p65 (NF-κB p65),phosphatidylinositol-3-kinase p85(PI-3K p85) and glucose transporter 4 (GLUT4) proteins were detected by Western blotting.The distribution of NF-κB p65 proteins inside the adipocytes was observed through confocal laser scanning microscopy(CLSM).RESULTS:After the intervention of palmic acid for 24 h,the insulin-stimulated glucose transport in 3T3-L1 adipocytes was inhibited by 67%.Meanwhile,the expression of IRS-1 and PI-3K p85 protein was reduced,while the levels of IKKβ Ser181 and IRS-1 Ser307 phosphorylation,and nuclear translocation of NF-κB p65 protein were increased.However,the above indexes,which indicated the existence of insulin resistance,were reversed by berberine although the expression of GLUT4,IKKβ and total NF-κB p65 protein were not changed during this study.CONCLUSION:Insulin resistance induced by FFAs in 3T3-L1 adipocytes can be improved by berberine.Berberine reversed free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ.

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

    Science.gov (United States)

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

    2014-10-01

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

  4. 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 ......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...

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

    Science.gov (United States)

    Sasaki, A; Goldberg, I J

    1992-07-25

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

  6. 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...

  7. The anti-obesity effects of a tuna peptide on 3T3-L1 adipocytes are mediated by the inhibition of the expression of lipogenic and adipogenic genes and by the activation of the Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Kim, Young-Min; Kim, In-Hye; Choi, Jeong-Wook; Lee, Min-Kyeong; Nam, Taek-Jeong

    2015-08-01

    The differentiation of 3T3-L1 cells into adipocytes involves the activation of an organized system of obesity-related genes, of which those encoding CCAAT/enhancer-binding proteins (C/EBPs) and the Wnt-10b protein may play integral roles. In a previous study of ours, we found that a specific peptide found in tuna (sequence D-I-V-D-K-I-E-I; termed TP-D) inhibited 3T3-L1 cell differentiation. In the present study, we observed that the expression of expression of C/EBPs and Wnt-10b was associated with obesity. The initial step of 3T3-L1 cell differentiation involved the upregulation of C/EBP-α expression, which in turn activated various subfactors. An upstream effector of glycogen synthase kinase-3β (GSK-3β) inhibited Wnt-10b expression in 3T3-L1 adipocytes. In a previous study of ours, we sequenced the tuna peptide via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and quadrupole time-of-flight mass spectrometry (Q-TOF MS/MS) and confirmed the anti-obesity effects thereof in 3T3-L1 adipocytes. In the present study, we demonstrate that TP-D inhibits C/EBP and promotes Wnt-10b mRNA expression, thus activating the Wnt pathway. The inhibition of lipid accumulation was measured using a glucose and triglyceride (TG) assay. Our results confirmed that TP-D altered the expression levels of C/EBP-related genes in a dose-dependent manner and activated the Wnt signaling pathway. In addition, we confirmed that total adiponectin and high-molecular weight (HMW) adiponectin levels were reduced by treatment with TP-D. These data indicate that TP-D inhibits adipocyte differentiation through the inhibition of C/EBP genes and the subsequent activation of the Wnt/β-catenin signaling pathway.

  8. The anti-obesity effects of a tuna peptide on 3T3-L1 adipocytes are mediated by the inhibition of the expression of lipogenic and adipogenic genes and by the activation of the Wnt/β-catenin signaling pathway

    Science.gov (United States)

    KIM, YOUNG-MIN; KIM, IN-HYE; CHOI, JEONG-WOOK; LEE, MIN-KYEONG; NAM, TAEK-JEONG

    2015-01-01

    The differentiation of 3T3-L1 cells into adipocytes involves the activation of an organized system of obesity-related genes, of which those encoding CCAAT/enhancer-binding proteins (C/EBPs) and the Wnt-10b protein may play integral roles. In a previous study of ours, we found that a specific peptide found in tuna (sequence D-I-V-D-K-I-E-I; termed TP-D) inhibited 3T3-L1 cell differentiation. In the present study, we observed that the expression of expression of C/EBPs and Wnt-10b was associated with obesity. The initial step of 3T3-L1 cell differentiation involved the upregulation of C/EBP-α expression, which in turn activated various subfactors. An upstream effector of glycogen synthase kinase-3β (GSK-3β) inhibited Wnt-10b expression in 3T3-L1 adipocytes. In a previous study of ours, we sequenced the tuna peptide via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and quadrupole time-of-flight mass spectrometry (Q-TOF MS/MS) and confirmed the anti-obesity effects thereof in 3T3-L1 adipocytes. In the present study, we demonstrate that TP-D inhibits C/EBP and promotes Wnt-10b mRNA expression, thus activating the Wnt pathway. The inhibition of lipid accumulation was measured using a glucose and triglyceride (TG) assay. Our results confirmed that TP-D altered the expression levels of C/EBP-related genes in a dose-dependent manner and activated the Wnt signaling pathway. In addition, we confirmed that total adiponectin and high-molecular weight (HMW) adiponectin levels were reduced by treatment with TP-D. These data indicate that TP-D inhibits adipocyte differentiation through the inhibition of C/EBP genes and the subsequent activation of the Wnt/β-catenin signaling pathway. PMID:26046125

  9. Proteomic profiling of lipid droplet-associated proteins in primary adipocytes of normal and obese mouse

    Institute of Scientific and Technical Information of China (English)

    Yubo Ding; Yibo Wu; Rong Zeng; Kan Liao

    2012-01-01

    Lipid droplets in adipocytes serve as the principal longterm energy storage depot of animals.There is increasing recognition that lipid droplets are not merely a static neutral lipid storage site,but in fact dynamic and multifunctional organelles.Structurally,lipid droplet consists of a neutral lipid core surrounded by a phospholipid monolayer and proteins embedded in or bound to the phospholipid layer.Proteins on the surface of lipid droplets are crucial to droplet structure and dynamics.To understand the lipid droplet-associated proteome of primary adipocyte with a large central lipid droplet,lipid droplets of white adipose tissue from C57BL/6 mice were isolated.And the proteins were extracted and analyzed by liquid chromatography coupled with tandem mass spectrometry.A total of 193 proteins including 73 previously unreported proteins were identified.Furthermore,the isotope-coded affinity tags (ICAT) was used to compare the difference of lipid droplet-associated proteomes between the normal lean and the high-fat diet-induced obese C57BL/6 mice.Of 23proteins quantified by ICAT analysis,3 proteins were upregulated and 4 proteins were down-regulated in the lipid droplets of adipose tissue from the obese mice.Importantly,two structural proteins of lipid droplets,perilipin A and vimentin,were greatly reduced in the lipid droplets of the adipose tissue from the obese mice,implicating reduced protein machinery for lipid droplet stability.

  10. 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...

  11. Modulation of the cellular content of metabolites in adipocytes by insulin.

    Science.gov (United States)

    Qiao, Yuhang; Tomonaga, Shozo; Matsui, Tohru; Funaba, Masayuki

    2016-03-15

    Although the insulin-mediated cell signaling pathway has been extensively examined, changes in the cellular content of metabolites currently remain unclear. We herein examined metabolite contents in 3T3-L1 adipocytes treated with insulin using a metabolomic analysis. Fifty-four compounds were detected, and the contents of metabolites from the citric acid cycle increased in response to the insulin treatment for 4 h, which was sensitive to U0126 and LY294002, inhibitors for mitogen-activated protein kinase kinase-1 and phosphoinositide 3-kinase, respectively. The cellular contents of fumaric acid and malic acid were increased more by insulin than those of citric acid and succinic acid. Time-course changes in metabolites from the citric acid cycle exhibited oscillations with a 2-h cycle. A metabolic pathway analysis also indicated that insulin affected the metabolism of alanine, aspartate and glutamate, as well as that of arginine and proline. The contents of free amino acids were slightly decreased by the insulin treatment, while the co-treatment with U0126 and LY294002 abrogated these insulin-mediated decreases. The present study revealed the unexpected accumulation of citric acid cycle metabolites in adipocytes by insulin. Our results indicate the usefulness of metabolomic analyses for obtaining a more comprehensive understanding of the regulation of metabolic pathways in cell-culture systems.

  12. Differential effects of a gelatinase inhibitor on adipocyte differentiation and adipose tissue development.

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    Van Hul, Matthias; Bauters, Dries; Lijnen, Roger H

    2013-10-01

    (1) A potential role for the gelatinases in adipocyte differentiation in vitro and adipose tissue development in vivo was investigated using the gelatinase inhibitor tolylsam ((R)-3-methyl-2-[4-(3-p-tolyl-[1,2,4]oxadiazol-5-yl)-benzenesulphonylamino]-butyric acid). (2) Differentiation of murine 3T3-F442A preadipocytes (12 days after reaching confluence) into mature adipocytes in vitro was promoted in the presence of tolylsam (10-100 μmol/L). (3) De novo development of fat tissue in nude mice injected with preadipocytes and kept on a high-fat diet was significantly impaired following treatment with tolylsam (100 mg/kg per day for 4 weeks). (4) Adipose tissue development in matrix metalloproteinase (MMP)-2 deficient mice, kept on a high-fat diet, was significantly impaired following administration of tolylsam (100 mg/kg per day for 15 weeks). This was associated with markedly enhanced metabolic rate. (5) Treatment of MMP-2-deficient mice with tolylsam (100 mg/kg per day, 15 weeks) was associated with the preservation of collagen and a reduction in blood vessel size in adipose tissues in vivo. (6) Furthermore, plasma levels of triglycerides and free fatty acids were reduced by tolylsam treatment of MMP-2-deficient mice (100 mg/kg per day, 15 weeks), whereas nutrient adsorption in the intestine was not affected. (7) The results of the present study indicate that tolylsam promotes preadipocyte differentiation in vitro, but impairs adipose tissue development in vivo.

  13. Biomimetic injectable HUVEC-adipocytes/collagen/alginate microsphere co-cultures for adipose tissue engineering.

    Science.gov (United States)

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

    2013-05-01

    Engineering adipose tissue that has the ability to engraft and establish a vascular supply is a laudable goal that has broad clinical relevance, particularly for tissue reconstruction. In this article, we developed novel microtissues from surface-coated adipocyte/collagen/alginate microspheres and human umbilical vein endothelial cells (HUVECs) co-cultures that resembled the components and structure of natural adipose tissue. Firstly, collagen/alginate hydrogel microspheres embedded with viable adipocytes were obtained to mimic fat lobules. Secondly, collagen fibrils were allowed to self-assemble on the surface of the microspheres to mimic collagen fibrils surrounding the fat lobules in the natural adipose tissue and facilitate HUVEC attachment and co-cultures formation. Thirdly, the channels formed by the gap among the microspheres served as the room for in vitro prevascularization and in vivo blood vessel development. The endothelial cell layer outside the microspheres was a starting point of rapid vascular ingrowth. Adipose tissue formation was analyzed for 12 weeks at 4-week intervals by subcutaneous injection into the head of node mice. The vasculature in the regenerated tissue showed functional anastomosis with host blood vessels. Long-term stability of volume and weight of the injection was observed, indicating that the vasculature formed within the constructs benefited the formation, maturity, and maintenance of adipose tissue. This study provides a microsurgical method for adipose regeneration and construction of biomimetic model for drug screening studies.

  14. Effect of Diabetes Mellitus on Adipocyte-Derived Stem Cells in Rat.

    Science.gov (United States)

    Jumabay, Medet; Moon, Jeremiah H; Yeerna, Huwate; Boström, Kristina I

    2015-11-01

    Diabetes mellitus affects the adipose tissue and mesenchymal stem cells derived from the adipose stroma and other tissues. Previous reports suggest that bone morphogenetic protein 4 (BMP4) is involved in diabetic complications, at the same time playing an important role in the maintenance of stem cells. In this study, we used rats transgenic for human islet amyloid polypeptide (HIP rats), a model of type 2 diabetes, to study the effect of diabetes on adipocyte-derived stem cells, referred to as dedifferentiated fat (DFAT) cells. Our results show that BMP4 expression in inguinal adipose tissue is significantly increased in HIP rats compared to controls, whereas matrix Gla protein (MGP), an inhibitor of BMP4 is decreased as determined by quantitative PCR, and immunofluorescence. In addition, adipose vascularity and expression of multiple endothelial cell markers was increased in the diabetic tissue, visualized by immunofluorescence for endothelial markers. The endothelial markers co-localized with the enhanced BMP4 expression, suggesting that vascular cells play a role BMP4 induction. The DFAT cells are multipotent stem cells derived from white mature adipocytes that undergo endothelial and adipogenic differentiation. DFAT cells prepared from the inguinal adipose tissue in HIP rats exhibited enhanced proliferative capacity compared to wild type. In addition, their ability to undergo both endothelial cell and adipogenic lineage differentiation was enhanced, as well as their response to BMP4, as assessed by lineage marker expression. We conclude that the DFAT cells are affected by diabetic changes and may contribute to the adipose dysfunction in diabetes.

  15. Vitamin C inhibits leptin secretion and some glucose/lipid metabolic pathways in primary rat adipocytes.

    Science.gov (United States)

    Garcia-Diaz, D F; Campion, J; Milagro, F I; Boque, N; Moreno-Aliaga, M J; Martinez, J A

    2010-07-01

    Antioxidant-based treatments are emerging as an interesting approach to possibly counteract obesity fat accumulation complications, since this is accompanied by an increased systemic oxidative stress. The aim of this study was to analyze specific metabolic effects of vitamin C (VC) on epididymal primary rat adipocytes. Cells were isolated and incubated for 72 h in culture medium, in the absence or presence of 1.6 nM insulin, within a range of VC concentrations (5-1000 microM). Glucose- and lipid-related variables as well as the secretion/expression patterns of several obesity-related genes were assessed. It was observed that VC dose dependently inhibited glucose uptake and lactate production, and also reduced glycerol release in both control and insulin-treated cells. Also, VC caused a dramatic concentration-dependent fall in leptin secretion especially in insulin-stimulated cells. In addition, VC (200 microM) induced Cdkn1a and Casp8, partially inhibited Irs3, and together with insulin drastically reduced Gpdh (listed as Gpd1 in the MGI database) gene expressions. Finally, VC and insulin down-regulatory effects were observed on extracellular and intracellular reactive oxygen species production respectively. In summary, this experimental assay describes a specific effect of VC in isolated rat adipocytes on glucose and fat metabolism, and on the secretion/expression of important obesity-related proteins.

  16. 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.

  17. Leucaena leucocephala fruit aqueous extract stimulates adipogenesis, lipolysis, and glucose uptake in primary rat adipocytes.

    Science.gov (United States)

    Kuppusamy, Umah Rani; Arumugam, Bavani; Azaman, Nooriza; Jen Wai, Chai

    2014-01-01

    Leucaena leucocephala had been traditionally used to treat diabetes. The present study was designed to evaluate in vitro "insulin-like" activities of Leucaena leucocephala (Lam.) deWit. aqueous fruit extract on lipid and glucose metabolisms. The ability of the extract to stimulate adipogenesis, inhibit lipolysis, and activate radio-labeled glucose uptake was assessed using primary rat adipocytes. Quantitative Real-Time RT-PCR was performed to investigate effects of the extract on expression levels of genes (protein kinases B, AKT; glucose transporter 4, GLUT4; hormone sensitive lipase, HSL; phosphatidylinositol-3-kinases, PI3KA; sterol regulatory element binding factor 1, Srebp1) involved in insulin-induced signaling pathways. L. leucocephala aqueous fruit extract stimulated moderate adipogenesis and glucose uptake into adipocytes when compared to insulin. Generally, the extract exerted a considerable level of lipolytic effect at lower concentration but decreased gradually at higher concentration. The findings concurred with RT-PCR analysis. The expressions of GLUT4 and HSL genes were upregulated by twofold and onefold, respectively, whereas AKT, PI3KA, and Srebp1 genes were downregulated. The L. leucocephala aqueous fruit extract may be potentially used as an adjuvant in the treatment of Type 2 diabetes mellitus and weight management due to its enhanced glucose uptake and balanced adipogenesis and lipolysis properties.

  18. Histological findings in adipocytes when cellulite is treated with a variable-emission radiofrequency system.

    Science.gov (United States)

    Trelles, Mario A; van der Lugt, Claudia; Mordon, Serge; Ribé, Adriana; Al-Zarouni, Marwan

    2010-03-01

    Cellulite is a disorder of the subcutaneous fat layer and the overlying superficial skin. Recently, radiofrequency (RF) has been proposed as an effective treatment of cellulite; however, the mechanism through which the absorbed electrical energy acts on the tissue is still not fully clear. This study reports on the histological findings from biopsies taken immediately after a single RF treatment session, on cellulite located in the buttocks, with a novel technology called automatic multi-frequency and low impedance (AMFLI) RF. Tissue samples were stained with either haematoxylin and eosin (H&E), so that we could study the morphological findings, or with oil red O, to enable us to identify lipid deposits. The histological findings observed in biopsies taken after a single RF treatment showed changes in shape, size, and lipid content, as well as in cytoplasmic and nuclear morphology. After RF treatment adipocytes were more polyhedric, with irregular, degenerated membranes, with less or no lipid content and apoptotic changes. We postulate that RF treatment on cellulite produces a decrease in lipid content of cells as well as changes in the adipocyte membrane which will lead to cell rupture and the death and extrusion of lipid content out of the cell. Further studies are needed to characterise the nature of the extra-cellular lipid material that we have demonstrated with the oil red O stain in our biopsies.

  19. 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.

  20. mVps45 knockdown selectively modulates VAMP expression in 3T3-L1 adipocytes.

    Science.gov (United States)

    Sadler, Jessica B A; Roccisana, Jennifer; Virolainen, Minttu; Bryant, Nia J; Gould, Gwyn W

    2015-01-01

    Insulin stimulates the delivery of glucose transporter-4 (GLUT4)-containing vesicles to the surface of adipocytes. Depletion of the Sec1/Munc18 protein mVps45 significantly abrogates insulin-stimulated glucose transport and GLUT4 translocation. Here we show that depletion of mVps45 selectively reduced expression of VAMPs 2 and 4, but not other VAMP isoforms. Although we did not observe direct interaction of mVps45 with any VAMP isoform; we found that the cognate binding partner of mVps45, Syntaxin 16 associates with VAMPs 2, 4, 7 and 8 in vitro. Co-immunoprecipitation experiments in 3T3-L1 adipocytes revealed an interaction between Syntaxin 16 and only VAMP4. We suggest GLUT4 trafficking is controlled by the coordinated expression of mVps45/Syntaxin 16/VAMP4, and that depletion of mVps45 regulates VAMP2 levels indirectly, perhaps via reduced trafficking into specialized subcellular compartments.

  1. Mitochondrial stress causes increased succination of proteins in adipocytes in response to glucotoxicity.

    Science.gov (United States)

    Frizzell, Norma; Thomas, Sonia A; Carson, James A; Baynes, John W

    2012-07-15

    2SC [S-(2-succino)-cysteine] is a chemical modification formed by a Michael addition reaction of fumarate with cysteine residues in proteins. Formation of 2SC, termed 'succination' of proteins, increases in adipocytes grown in high-glucose medium and in adipose tissues of Type 2 diabetic mice. However, the metabolic mechanisms leading to increased fumarate and succination of protein in the adipocyte are unknown. Treatment of 3T3 cells with high glucose (30 mM compared with 5 mM) caused a significant increase in cellular ATP/ADP, NADH/NAD+ and Δψm (mitochondrial membrane potential). There was also a significant increase in the cellular fumarate concentration and succination of proteins, which may be attributed to the increase in NADH/NAD+ and subsequent inhibition of tricarboxylic acid cycle NAD+-dependent dehydrogenases. Chemical uncouplers, which dissipated Δψm and reduced the NADH/NAD+ ratio, also decreased the fumarate concentration and protein succination. High glucose plus metformin, an inhibitor of complex I in the electron transport chain, caused an increase in fumarate and succination of protein. Thus excess fuel supply (glucotoxicity) appears to create a pseudohypoxic environment (high NADH/NAD+ without hypoxia), which drives the increase in succination of protein. We propose that increased succination of proteins is an early marker of glucotoxicity and mitochondrial stress in adipose tissue in diabetes.

  2. Zinc-transporter genes in human visceral and subcutaneous adipocytes: lean versus obese.

    Science.gov (United States)

    Smidt, Kamille; Pedersen, Steen B; Brock, Birgitte; Schmitz, Ole; Fisker, Sanne; Bendix, Jørgen; Wogensen, Lise; Rungby, Jørgen

    2007-01-29

    Zinc ions influence adipose tissue metabolism by regulating leptin secretion and by promoting free fatty acid release and glucose uptake. The mechanisms controlling zinc metabolism in adipose tissue are unknown. We therefore examined the gene-expression levels of a number of zinc-transporting proteins in adipose tissue, comparing subcutaneous fat with visceral fat from lean and obese humans. Both ZnT-proteins responsible for zinc transport from cytosol to extracellular compartments and intracellular vesicles and Zip-proteins responsible for zinc transport to the cytoplasm were expressed in all samples. This suggests that zinc metabolism in adipocytes is actively controlled by zinc-transporters. The expression levels were different in lean and obese subjects suggesting a role for these proteins in obesity. Furthermore, the expression levels were different from subcutaneous fat to intra-abdominal fat suggesting that the metabolic activity in adipocytes is to some extent dependent upon zinc and the activity of zinc-transporting proteins or vice versa.

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

    Science.gov (United States)

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

    2016-01-01

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

  4. 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.

  5. Induction of adipocyte differentiation by polybrominated diphenyl ethers (PBDEs in 3T3-L1 cells.

    Directory of Open Access Journals (Sweden)

    Emily W Y Tung

    Full Text Available 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.

  6. Effects of Monoclonal Antibody Against Adipocyte-Specific Membrane Protein on Lipid Metabolism in Pigs

    Institute of Scientific and Technical Information of China (English)

    GAO Shi-zheng; LIU Ling-yun; ZHAO Su-mei; HU Hong-mei; GE Chang-rong; LIU Yong-gang; ZHANG Xi

    2008-01-01

    This study was to investigate the regulation of monoclonal antibodies against adipocyte membrane proteins(McAb)on lipid metabolism in pigs.Forty Landrace x Saba pigs were randomly divided in