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Sample records for caveolin-deficient adipocytes alterations

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

    OpenAIRE

    Blouin, C. M.; Le Lay, S.; Eberl, A.; Kofeler, H. C.; Guerrera, I. C.; Klein, C.; Le Liepvre, X.; Lasnier, F.; Bourron, O.; Gautier, J. F.; Ferre, P.; Hajduch, E.; Dugail, I.

    2010-01-01

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

  2. Altered adipocyte structure and function in nutritionally programmed microswine offspring

    OpenAIRE

    DuPriest, E. A.; Kupfer, P.; Lin, B; Sekiguchi, K.; Morgan, T. K.; Saunders, K. E.; Chatkupt, T. T.; Denisenko, O. N.; Purnell, J. Q.; Bagby, S. P.

    2012-01-01

    Adipose tissue (AT) dysfunction links obesity of any cause with cardiometabolic disease, but whether early-life nutritional deficiency can program adipocyte dysfunction independently of obesity is untested. In 3–5-month-old juvenile microswine offspring exposed to isocaloric perinatal maternal protein restriction (MPR) and exhibiting accelerated prepubertal fat accrual without obesity, we assessed markers of acquired obesity: adiponectin and tumor necrosis factor (TNF)-α messenger ribonucleic...

  3. Distinct Roles of Endothelial and Adipocyte Caveolin-1 in Macrophage Infiltration and Adipose Tissue Metabolic Activity

    OpenAIRE

    Briand, N.; Le Lay, S.; Sessa, W. C.; Ferre, P.; Dugail, I.

    2011-01-01

    OBJECTIVE Defective caveolin-1 expression is now recognized as a cause of lipoatrophic diabetes in patients, due to primary caveolin gene mutations or secondary caveolin deficiency caused by PTRF/cavin gene defects. The goal of this study was to establish the relative contribution of endothelial cells and adipocytes, both highly expressing caveolin-1 to the lipoatrophic phenotype of mice with global caveolin-1 gene invalidation (Cav1-KO). RESEARCH DESIGN AND METHODS We compared adipose tissue...

  4. Expression of the human apoE2 isoform in adipocytes: altered cellular processing and impaired adipocyte lipogenesis

    OpenAIRE

    Huang, Zhi H.; Maeda, Nobuyo; Mazzone, Theodore

    2011-01-01

    Expression of apoE in adipocytes has been shown to have an important role in modulating adipocyte triglyceride (TG) metabolism and gene expression that is independent of circulating and extracellular apoE. The impact of adipocyte expression of common human apoE isoforms was evaluated using adipocytes harvested from human apoE2, -3, and -4 knock-in mice. Expression of the apoE2 isoform was associated with an increase in adipocyte apoE gene expression and apoE synthesis. Newly synthesized apoE2...

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

    OpenAIRE

    De Pauw, Aurélia; Tejerina, Silvia; Raes, Martine; Keijer, Jaap; Arnould, Thierry

    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 developmental status and energy fluxes. Although numerous reviews have focused on the differentiation program of both brown and white adipocytes as well as on the pathophysiological role of white adipose tissu...

  6. 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

  7. Antiretroviral-Related Adipocyte Dysfunction and Lipodystrophy in HIV-Infected Patients: Alteration of the PPARγ-Dependent Pathways

    Directory of Open Access Journals (Sweden)

    Martine Caron

    2009-01-01

    Full Text Available Lipodystrophy and metabolic alterations are major complications of antiretroviral therapy in HIV-infected patients. In vitro studies using cultured murine and human adipocytes revealed that some protease inhibitors (PIs and nucleoside reverse transcriptase inhibitors (NRTIs were implicated to a different extent in adipose cell dysfunction and that a chronic incubation with some PIs decreased mRNA and protein expression of PPARγ. Defective lamin A maturation linked to PI inhibitory activity could impede the nuclear translocation of SREBP1c, therefore, reducing PPARγ expression. Adipose cell function was partially restored by the PPARγ agonists, thiazolidinediones. Adverse effects of PIs and NRTIs have also been reported in macrophages, a cell type that coexists with, and modulates, adipocyte function in fat tissue. In HIV-infected patients under ART, a decreased expression of PPARγ and of PPARγ-related genes was observed in adipose tissue, these anomalies being more severe in patients with ART-induced lipoatrophy. Altered PPARγ expression was reversed in patients stopping PIs. Treatment of patients with agonists of PPARγ could improve, at least partially, the subcutaneous lipoatrophy. These data indicate that decreased PPARγ expression and PPARγ-related function, resulting from ART-induced adipose tissue toxicity, play a central role in HIV-related lipoatrophy and metabolic consequences.

  8. Alteration of proteoglycan metabolism during the differentiation of 3T3- L1 fibroblasts into adipocytes

    OpenAIRE

    1991-01-01

    3T3-L1 fibroblasts were induced to differentiate to 3T3-L1 adipocytes by dexamethasone, isobutyl-methylxanthine, and insulin. To study how differentiation affects extracellular matrix production, the accumulation of proteoglycans was studied by labeling the 3T3-L1 cells with [35S]sulphate for 24 h. The labeled proteoglycans were isolated from the medium and cell layer extracts by anion-exchange chromatography. They were then taken to gel filtration chromatography on Superose 6 before or after...

  9. 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.

  10. Mature adipocyte proteome reveals differentially altered protein abundances between lean, overweight and morbidly obese human subjects.

    Science.gov (United States)

    Benabdelkamel, Hicham; Masood, Afshan; Almidani, Ghaith M; Alsadhan, Abdulmajeed A; Bassas, Abdulelah F; Duncan, Mark W; Alfadda, Assim A

    2015-02-01

    Overweight (OW) and obese individuals are considered to be graded parts of the scale having increasing weight as a common feature. They may not, however, be part of the same continuum and may differ metabolically. In this study we applied an untargeted proteomic approach to compare protein abundances in mature adipocytes derived from the subcutaneous adipose tissue of overweight and morbidly obese female subjects to those of lean age matched controls. Mature adipocytes were isolated from liposuction samples of abdominal subcutaneous adipose tissue collected from both lean (L; n = 7, 23.3 ± 0.4 kg/m(2); mean BMI ± SD), overweight (OW; n = 8, 27.9 ± 0.6 kg/m(2); mean BMI ± SD) and morbidly obese (MOB; n = 7, 44.8 ± 3.8 kg/m(2); mean BMI ± SD) individuals. Total protein extracts were then compared by two-dimensional difference in gel electrophoresis (2D DIGE). One hundred and ten differentially expressed protein spots (i.e., fitting the statistical criteria ANOVA test, p interaction; in contrast, in the MOB group the major interacting pathways are associated with lipid metabolism, small molecule biochemistry and cancer. The differences in abundance of the differentially regulated proteins were validated by immunoblotting. These findings provide insights into metabolic differences in OW and MOB individuals. PMID:25498962

  11. 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.

  12. 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

    2014-01-01

    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. PMID:25308841

  13. 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

  14. 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.

  15. 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

  16. Calcium-Induced Alteration of Mitochondrial Morphology and Mitochondrial-Endoplasmic Reticulum Contacts in Rat Brown Adipocytes

    OpenAIRE

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

    2014-01-01

    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 ad...

  17. Polychlorinated biphenyls (PCB 101, PCB 153 and PCB 180) alter leptin signaling and lipid metabolism in differentiated 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    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

  18. 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

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

    Directory of Open Access Journals (Sweden)

    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

  20. Exercise Decreases Lipogenic Gene Expression in Adipose Tissue and Alters Adipocyte Cellularity during Weight Regain After Weight Loss.

    Science.gov (United States)

    Giles, Erin D; Steig, Amy J; Jackman, Matthew R; Higgins, Janine A; Johnson, Ginger C; Lindstrom, Rachel C; MacLean, Paul S

    2016-01-01

    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. 24 h retention of dietary- and de novo-derived fat were assessed directly using (14)C palmitate/oleate and (3)H20, 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 and LPL), de novo lipogenesis (FAS, ACC1), and triacylglycerol synthesis (MGAT and 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

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

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    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.

  2. Inflamed macrophage microvesicles induce insulin resistance in human adipocytes

    OpenAIRE

    Zhang, Yaqin; Shi, Li; Mei, Hongliang; Zhang, Jiexin; Zhu, Yunxia; Han, Xiao; Zhu, Dalong

    2015-01-01

    Background Cytokines secreted by adipose tissue macrophages (ATMs) significantly alter adipocyte function, inducing inflammatory responses and decreasing insulin sensitivity. However, little relevant information is available regarding the role of microvesicles (MVs) derived from ATMs in macrophage-adipocyte crosstalk. Methods MVs were generated by stimulation of M1 or M2 phenotype THP-1 macrophages and incubated with human primary mature adipocytes and differentiated adipocytes. Subsequently,...

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

    Science.gov (United States)

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

    2016-08-01

    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

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

    Science.gov (United States)

    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

  5. PPARγ activation alters fatty acid composition in adipose triglyceride, in addition to proliferation of small adipocytes, in insulin resistant high-fat fed rats.

    Science.gov (United States)

    Sato, Daisuke; Oda, Kanako; Kusunoki, Masataka; Nishina, Atsuyoshi; Takahashi, Kazuaki; Feng, Zhonggang; Tsutsumi, Kazuhiko; Nakamura, Takao

    2016-02-15

    It was reported that adipocyte size is potentially correlated in part to amount of long chain polyunsaturated fatty acids (PUFAs) and insulin resistance because several long chain PUFAs can be ligands of peroxisome proliferator-activated receptors (PPARs). In our previous study, marked reduction of PUFAs was observed in insulin-resistant high-fat fed rats, which may indicate that PUFAs are consumed to improve insulin resistance. Although PPARγ agonist, well known as an insulin sensitizer, proliferates small adipocytes, the effects of PPARγ agonist on FA composition in adipose tissue have not been clarified yet. In the present study, we administered pioglitazone, a PPARγ agonist, to high-fat fed rats, and measured their FA composition of triglyceride fraction in adipose tissue and adipocyte diameters in pioglitazone-treated (PIO) and non-treated (control) rats. Insulin sensitivity was obtained with hyperinsulinemic euglycemic clamp. Average adipocyte diameter in the PIO group were smaller than that in the control one without change in tissue weight. In monounsaturated FAs (MUFAs), 14:1n-5, 16:1n-7, and 18:1n-9 contents in the PIO group were lower than those, respectively, in the control group. In contrast, 22:6n-3, 20:3n-6, 20:4n-6, and 22:4n-6 contents in the PIO group were higher than those, respectively, in the control group. Insulin sensitivity was higher in the PIO group than in the control one. These findings suggest that PPARγ activation lowered MUFAs whereas suppressed most of C20 or C22 PUFAs reduction, and that the change of fatty acid composition may be relevant with increase in small adipocytes. PMID:26825545

  6. 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, an......, 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......The ability to modify the transcriptional program in response to external signals provides a way for mammalian cells to alter their biological fate and properties, thereby adapting to changes in the environment. Adipocytes are excellent examples of differentiated cells that possess a striking...

  7. Dynamics of Adipocyte Turnover in Humans

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-16

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

  8. 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.

  9. 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. PMID:19695247

  10. 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....

  11. Adipocytes Secrete Leukotrienes

    OpenAIRE

    Mothe-Satney, Isabelle; Filloux, Chantal; Amghar, Hind; Pons, Catherine; Bourlier, Virginie; Galitzky, Jean; Paul A. Grimaldi; Féral, Chloé C.; Bouloumié, Anne; Obberghen, Emmanuel Van; Neels, Jaap G.

    2012-01-01

    Leukotrienes (LTs) are potent proinflammatory mediators, and many important aspects of innate and adaptive immune responses are regulated by LTs. Key members of the LT synthesis pathway are overexpressed in adipose tissue (AT) during obesity, resulting in increased LT levels in this tissue. We observed that several mouse adipocyte cell lines and primary adipocytes from mice and humans both can secrete large amounts of LTs. Furthermore, this production increases with a high-fat diet (HFD) and ...

  12. Role of adipocyte-derived apoE in modulating adipocyte size, lipid metabolism, and gene expression in vivo

    OpenAIRE

    Huang, Zhi Hua; Gu, DeSheng; Mazzone, Theodore

    2009-01-01

    Adipocytes isolated from apolipoprotein E (apoE)-knockout (EKO) mice display alterations in triglyceride (TG) metabolism and gene expression. The present studies were undertaken to evaluate the impact of endogenously produced adipocyte apoE on these adipocyte parameters in vivo, independent of the profoundly disturbed metabolic milieu of EKO mice. Adipose tissue from wild-type (WT) or EKO mice was transplanted into WT recipients, which were then fed chow or high-fat diet for 8–10 wk. After a ...

  13. Visceral Adipocyte Hypertrophy is Associated With Dyslipidemia Independent of Body Composition and Fat Distribution in Women

    OpenAIRE

    Veilleux, Alain; Caron-Jobin, Maude; Noël, Suzanne; Laberge, Philippe Y.; Tchernof, André

    2011-01-01

    OBJECTIVE We assessed whether subcutaneous and omental adipocyte hypertrophy are related to metabolic alterations independent of body composition and fat distribution in women. RESEARCH DESIGN AND METHODS Mean adipocyte diameter of paired subcutaneous and omental adipose tissue samples was obtained in lean to obese women. Linear regression models predicting adipocyte size in both adipose tissue depots were computed using body composition and fat distribution measures (n = 150). In a given dep...

  14. PPARs and adipocyte function

    OpenAIRE

    Christodoulides, Constantinos; Vidal-Puig, Antonio

    2010-01-01

    Abstract For long viewed as passive lipid storage depots, adipocytes are now recognised as key players in the pathogenesis of insulin resistance and metabolic disease. In parallel, the last two decades of research have seen the emergence of transcription factors of the peroxisome proliferator-activated receptor (PPAR) family as central regulators of lipid and glucose homeostasis and molecular targets for drugs to treat hyper-lipidaemia and type 2 diabetes mellitus. In this review w...

  15. Interleukin-1β mediates macrophage-induced impairment of insulin signaling in human primary adipocytes

    OpenAIRE

    Gao, Dan; Madi, Mohamed; Ding, Cherlyn; Fok, Matthew; Steele, Thomas; FORD, CHRISTOPHER; Hunter, Leif; Bing, Chen

    2014-01-01

    Adipose tissue expansion during obesity is associated with increased macrophage infiltration. Macrophage-derived factors significantly alter adipocyte function, inducing inflammatory responses and decreasing insulin sensitivity. Identification of the major factors that mediate detrimental effects of macrophages on adipocytes may offer potential therapeutic targets. IL-1β, a proinflammatory cytokine, is suggested to be involved in the development of insulin resistance. This study investigated ...

  16. Relationship of adipocyte size with adiposity and metabolic risk factors in Asian Indians.

    Directory of Open Access Journals (Sweden)

    Ved Prakash Meena

    Full Text Available Enlargement of adipocyte is associated with their dysfunction and alterations in metabolic functions.We evaluated the association of adipocyte size of subcutaneous and omental adipose tissue with body composition and cardiovascular risk factors in Asian Indians.Eighty (40 males and 40 females non-diabetic adult subjects undergoing elective abdominal surgery were included. Pre-surgery evaluation included anthropometric measurements, % body fat by bioimpedance, abdominal fat area at L2-3 level (computed tomography and biochemical investigations (fasting blood glucose and insulin, lipids and hsCRP. During surgery, about 5 grams each of omental and subcutaneous adipose tissue was obtained for adipocyte size determination.Females had higher BMI, % body fat, skinfold thickness, total and subcutaneous abdominal fat area as compared to males. Overweight was present in 42.5% and 67.5%, and abdominal obesity in 5% and 52.5% males and females, respectively. Subcutaneous adipocyte size was significantly higher than omental adipocyte size. Omental adipocyte size correlated more strongly than subcutaneous adipocyte size with measures of adiposity (BMI, waist circumference, %BF, total and subcutaneous abdominal fat area and biochemical measures (fasting glucose, total cholesterol, triglycerides and HOMA-IR, the correlations being stronger in females. The correlation of adipocyte size with metabolic parameters was attenuated after adjusting for measures of adiposity.Omental adipocyte size, though smaller than the subcutaneous adipocyte size, was more closely related to measures of adiposity and metabolic parameters. However, the relationship was not independent of measures of adiposity.

  17. Weighing in on Adipocyte Precursors

    OpenAIRE

    Berry, Ryan; Jeffery, Elise; Rodeheffer, Matthew S.

    2013-01-01

    Obesity, defined as an excessive increase in white adipose tissue (WAT), is a global health epidemic. In obesity, WAT expands by increased adipocyte size (hypertrophy) and number (hyperplasia). The location and cellular mechanisms of WAT expansion greatly affect the pathogenesis of obesity. However, the cellular and molecular mechanisms regulating adipocyte size, number and depot-dependent expansion in vivo remain largely unknown. This perspective summarizes previous work addressing adipocyte...

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

    Directory of Open Access Journals (Sweden)

    Orlando Robert A

    2007-10-01

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

  19. 3T3-L1 adipocytes display phenotypic characteristics of multiple adipocyte lineages

    Science.gov (United States)

    Morrison, Shona; McGee, Sean L

    2015-01-01

    Differentiated 3T3-L1 adipocytes are a widely used in vitro model of white adipocytes. In addition to classical white and brown adipocytes that are derived from different cell lineages, beige adipocytes have also been identified, which have characteristics of both white and brown adipocytes. Here we show that 3T3-L1 adipocytes display features of multiple adipocytes lineages. While the gene expression profile and basal bioenergetics of 3T3-L1 adipocytes was typical of white adipocytes, they responded acutely to catecholamines by increasing oxygen consumption in an UCP1-dependent manner, and by increasing the expression of genes enriched in brown but not beige adipocytes. Chronic exposure to catecholamines exacerbated this phenotype. However, a beige adipocyte differentiation procedure did not induce a beige adipocyte phenotype in 3T3-L1 fibroblasts. These multiple lineage features should be considered when interpreting data from experiments utilizing 3T3-L1 adipocytes. PMID:26451286

  20. 3T3-L1 adipocytes display phenotypic characteristics of multiple adipocyte lineages

    OpenAIRE

    Morrison, Shona; McGee, Sean L.

    2015-01-01

    Differentiated 3T3-L1 adipocytes are a widely used in vitro model of white adipocytes. In addition to classical white and brown adipocytes that are derived from different cell lineages, beige adipocytes have also been identified, which have characteristics of both white and brown adipocytes. Here we show that 3T3-L1 adipocytes display features of multiple adipocytes lineages. While the gene expression profile and basal bioenergetics of 3T3-L1 adipocytes was typical of white adipocytes, they r...

  1. Liver X receptor (LXR) regulates human adipocyte lipolysis.

    Science.gov (United States)

    Stenson, Britta M; Rydén, Mikael; Venteclef, Nicolas; Dahlman, Ingrid; Pettersson, Annie M L; Mairal, Aline; Aström, Gaby; Blomqvist, Lennart; Wang, Victoria; Jocken, Johan W E; Clément, Karine; Langin, Dominique; Arner, Peter; Laurencikiene, Jurga

    2011-01-01

    The Liver X receptor (LXR) is an important regulator of carbohydrate and lipid metabolism in humans and mice. We have recently shown that activation of LXR regulates cellular fuel utilization in adipocytes. In contrast, the role of LXR in human adipocyte lipolysis, the major function of human white fat cells, is not clear. In the present study, we stimulated in vitro differentiated human and murine adipocytes with the LXR agonist GW3965 and observed an increase in basal lipolysis. Microarray analysis of human adipocyte mRNA following LXR activation revealed an altered gene expression of several lipolysis-regulating proteins, which was also confirmed by quantitative real-time PCR. We show that expression and intracellular localization of perilipin1 (PLIN1) and hormone-sensitive lipase (HSL) are affected by GW3965. Although LXR activation does not influence phosphorylation status of HSL, HSL activity is required for the lipolytic effect of GW3965. This effect is abolished by PLIN1 knockdown. In addition, we demonstrate that upon activation, LXR binds to the proximal regions of the PLIN1 and HSL promoters. By selective knock-down of either LXR isoform, we show that LXRα is the major isoform mediating the lipolysis-related effects of LXR. In conclusion, the present study demonstrates that activation of LXRα up-regulates basal human adipocyte lipolysis. This is at least partially mediated through LXR binding to the PLIN1 promoter and down-regulation of PLIN1 expression. PMID:21030586

  2. Liver X Receptor (LXR) Regulates Human Adipocyte Lipolysis*

    Science.gov (United States)

    Stenson, Britta M.; Rydén, Mikael; Venteclef, Nicolas; Dahlman, Ingrid; Pettersson, Annie M. L.; Mairal, Aline; Åström, Gaby; Blomqvist, Lennart; Wang, Victoria; Jocken, Johan W. E.; Clément, Karine; Langin, Dominique; Arner, Peter; Laurencikiene, Jurga

    2011-01-01

    The Liver X receptor (LXR) is an important regulator of carbohydrate and lipid metabolism in humans and mice. We have recently shown that activation of LXR regulates cellular fuel utilization in adipocytes. In contrast, the role of LXR in human adipocyte lipolysis, the major function of human white fat cells, is not clear. In the present study, we stimulated in vitro differentiated human and murine adipocytes with the LXR agonist GW3965 and observed an increase in basal lipolysis. Microarray analysis of human adipocyte mRNA following LXR activation revealed an altered gene expression of several lipolysis-regulating proteins, which was also confirmed by quantitative real-time PCR. We show that expression and intracellular localization of perilipin1 (PLIN1) and hormone-sensitive lipase (HSL) are affected by GW3965. Although LXR activation does not influence phosphorylation status of HSL, HSL activity is required for the lipolytic effect of GW3965. This effect is abolished by PLIN1 knockdown. In addition, we demonstrate that upon activation, LXR binds to the proximal regions of the PLIN1 and HSL promoters. By selective knock-down of either LXR isoform, we show that LXRα is the major isoform mediating the lipolysis-related effects of LXR. In conclusion, the present study demonstrates that activation of LXRα up-regulates basal human adipocyte lipolysis. This is at least partially mediated through LXR binding to the PLIN1 promoter and down-regulation of PLIN1 expression. PMID:21030586

  3. Estrogen Sulfotransferase Inhibits Adipocyte Differentiation

    OpenAIRE

    Wada, Taira; Ihunnah, Chibueze A.; Gao, Jie; Chai, Xiaojuan; Zeng, Su; Philips, Brian J.; Rubin, J. Peter; Marra, Kacey G.; Xie, Wen

    2011-01-01

    The estrogen sulfotransferase (EST) is a phase II drug-metabolizing enzyme known to catalyze the sulfoconjugation of estrogens. EST is highly expressed in the white adipose tissue of male mice, but the role of EST in the development and function of adipocytes remains largely unknown. In this report, we showed that EST played an important role in adipocyte differentiation. EST was highly expressed in 3T3-L1 preadipocytes and primary mouse preadipocytes. The expression of EST was dramatically r...

  4. Characteristics of metabolic changes in adipocytes of growing rats.

    Science.gov (United States)

    Gwóźdź, Kinga; Szkudelski, Tomasz; Szkudelska, Katarzyna

    2016-06-01

    Adipocytes, cells of white fat tissue, store energy in the form of lipids and have also endocrine functions. Disturbances in adipocyte metabolism lead to decreased or excessive fat tissue accumulation and are associated with numerous diseases. Pathologic alterations in adipose tissue are known to develop with age, however, changes in young, growing subjects are poorly elucidated. In the present study, glucose transport and metabolism, hyperpolarization of the inner mitochondrial membrane and the lipolytic activity were compared in the epididymal adipocytes of 8-week-old and 16-week-old rats. It was demonstrated that glucose conversion to lipids, glucose transport and oxidation was decreased in the adipocytes of the older animals. These effects were accompanied by increase in lactate release and by decrease in hyperpolarization of the mitochondrial membrane. Lipolytic response to epinephrine was increased (at lower concentrations of the hormone) or reduced (at higher concentration) in the adipocytes of the older rats. However, induction of lipolysis by the direct activation of protein kinase A induced similar response. It was also demonstrated that inhibition of phosphodiesterase 3B or adenosine A1 receptor blocking caused lower lipolysis in the cells of the older rats. Moreover, antilipolytic action of insulin was impaired in the adipocytes of these rats, probably due to changes in the initial steps of the insulin signaling pathway. However, the use of the pharmacologic inhibitor of protein kinase A instead of insulin resulted in similar antilipolysis in both groups of cells. These results show that, in spite of relatively small age difference, substantial changes in adipose tissue metabolism develop in these animals. Decreased response to insulin action seems to be particularly relevant finding. PMID:27060433

  5. Relationship of Adipocyte Size with Adiposity and Metabolic Risk Factors in Asian Indians

    OpenAIRE

    Ved Prakash Meena; V Seenu; Sharma, M. C.; Saumya Ranjan Mallick; Ashu Seith Bhalla; Nandita Gupta; Anant Mohan; Randeep Guleria; Ravindra M. Pandey; Kalpana Luthra; Naval K. Vikram

    2014-01-01

    Background Enlargement of adipocyte is associated with their dysfunction and alterations in metabolic functions. Objectives We evaluated the association of adipocyte size of subcutaneous and omental adipose tissue with body composition and cardiovascular risk factors in Asian Indians. Methodology Eighty (40 males and 40 females) non-diabetic adult subjects undergoing elective abdominal surgery were included. Pre-surgery evaluation included anthropometric measurements, % body fat by bioimpedan...

  6. Low-Dose Bisphenol-A Impairs Adipogenesis and Generates Dysfunctional 3T3-L1 Adipocytes.

    Directory of Open Access Journals (Sweden)

    Fabiana Ariemma

    Full Text Available Environmental endocrine disruptors (EDCs, including bisphenol-A (BPA, have been recently involved in obesity and diabetes by dysregulating adipose tissue function. Our aim was to examine whether prolonged exposure to low doses of BPA could affect adipogenesis and adipocyte metabolic functions. Therefore, 3T3-L1 pre-adipocytes were cultured for three weeks with BPA 1 nM to mimic human environmental exposure. We evaluated BPA effect on cell proliferation, differentiation, gene expression and adipocyte metabolic function. BPA significantly increased pre-adipocyte proliferation (p<0.01. In 3T3-L1 adipocytes differentiated in the presence of BPA, the expression of Peroxisome proliferator-activated receptor gamma (PPARγ, Fatty Acid Binding Protein 4/Adipocyte Protein 2 (FABP4/AP2 and CCAAT/enhancer binding protein (C/EBPα was increased by 3.5, 1.5 and 3 folds, respectively. Mature adipocytes also showed a significant increase in lipid accumulation (p<0.05 and alterations of insulin action, with significant reduction in insulin-stimulated glucose utilization (p<0.001. Moreover, in mature adipocytes, mRNA levels of Leptin, interleukin-6 (IL6 and interferon-γ (IFNγ were significantly increased (p<0.05. In conclusion, BPA prolonged exposure at low doses, consistent with those found in the environment, may affect adipocyte differentiation program, enhancing pre-adipocyte proliferation and anticipating the expression of the master genes involved in lipid/glucose metabolism. The resulting adipocytes are hypertrophic, with impaired insulin signaling, reduced glucose utilization and increased pro-inflammatory cytokine expression. Thus, these data supported the hypothesis that BPA exposure, during critical stages of adipose tissue development, may cause adipocyte metabolic dysfunction and inflammation, thereby increasing the risk of developing obesity-related diseases.

  7. Adipocyte differentiation and leptin expression

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  8. 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

  9. Characterization of the Human Adipocyte Proteome and Reproducibility of Protein Abundance by One-dimensional Gel Electrophoresis and HPLC-ESI-MS/MS

    OpenAIRE

    Xie, Xitao; Yi, Zhengping; Bowen, Benjamin; Wolf, Cassandra; Flynn, Charles R; Sinha, Sandeep; Mandarino, Lawrence J.; Meyer, Christian

    2010-01-01

    Abnormalities in adipocytes play an important role in various conditions, including the metabolic syndrome, type 2 diabetes mellitus and cardiovascular disease, but little is known about alterations at the protein level. We therefore sought to 1) comprehensively characterize the human adipocyte proteome for the first time, and 2) demonstrate feasibility of measuring adipocyte protein abundances by one-dimensional SDS-PAGE and High Performance Liquid Chromatography -Electron Spray Ionization -...

  10. Effect of Adipocyte Secretome in Melanoma Progression and Vasculogenic Mimicry.

    Science.gov (United States)

    Coelho, Pedro; Almeida, Joana; Prudêncio, Cristina; Fernandes, Rúben; Soares, Raquel

    2016-07-01

    Obesity, favored by the modern lifestyle, acquired epidemic proportions nowadays. Obesity has been associated with various major causes of death and morbidity including malignant neoplasms. This increased prevalence has been accompanied by a worldwide increase in cutaneous melanoma incidence rates during the last decades. Obesity involvement in melanoma aetiology has been recognized, but the implicated mechanisms remain unclear. In the present study, we address this relationship and investigate the influence of adipocytes secretome on B16-F10 and MeWo melanoma cell lines. Using the 3T3-L1 adipocyte cell line, as well as ex vivo subcutaneous (SAT) and visceral (VAT) adipose tissue conditioned medium, we were able to show that adipocyte-released factors play a dual role in increasing melanoma cell overall survival, both by enhancing proliferation and decreasing apoptosis. B16-F10 cell migration and cell-cell and cell-matrix adhesion capacity were predominantly enhanced in the presence of SAT and VAT released factors. Melanocytes morphology and melanin content were also altered by exposure to adipocyte conditioned medium disclosing a more dedifferentiated phenotype of melanocytes. In addition, exposure to adipocyte-secreted molecules induced melanocytes to rearrange, on 3D cultures, into vessel-like structures, and generate characteristic vasculogenic mimicry patterns. These findings are corroborated by the released factors profile of 3T3-L1, SAT, and VAT assessed by microarrays, and led us to highlight the mechanisms by which adipose secretome from sub-cutaneous or visceral depots promote melanoma progression. J. Cell. Biochem. 117: 1697-1706, 2016. © 2015 Wiley Periodicals, Inc. PMID:26666522

  11. 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

    OpenAIRE

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

    2010-01-01

    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 wi...

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

    Science.gov (United States)

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

    2016-09-01

    Adipose tissue is a dynamic organ that provides endocrine, inflammatory and angiogenic factors, which can assist breast carcinoma cells with invasion and metastasis. Previous studies have shown that adipocytes adjacent to carcinoma, known as cancer-associated adipocytes, undergo extensive changes that correspond to an "activated phenotype," such as reduced size relative to adipocytes in non-neoplastic breast tissue. Optical imaging provides a tool that can be used to characterize adipocyte morphology and other features of the tumor microenvironment. In this study, we used confocal fluorescence microscopy to acquire images of freshly excised breast tissue stained topically with proflavine. We developed a computerized algorithm to identify and quantitatively measure phenotypic properties of adipocytes located adjacent to and far from normal collagen, ductal carcinoma in situ and invasive ductal carcinoma. Adipocytes were measured in confocal fluorescence images of fresh breast tissue collected from 22 patients. Results show that adipocytes adjacent to neoplastic tissue margins have significantly smaller area compared to adipocytes far from the margins of neoplastic lesions and compared to adipocytes adjacent to non-neoplastic collagenous stroma. These findings suggest that confocal microscopic images can be utilized to evaluate phenotypic properties of adipocytes in breast stroma which may be useful in defining alterations in microenvironment that may aid in the development and progression of neoplastic lesions. PMID:27116366

  13. Adipocytes in Skin Health and Disease

    OpenAIRE

    Rivera-Gonzalez, Guillermo; Shook, Brett; Horsley, Valerie

    2014-01-01

    Adipocytes are intimately associated with the dermal compartment of the skin, existing in a specialized dermal depot and displaying dynamic changes in size during tissue homeostasis. However, the roles of adipocytes in cutaneous biology and disease are not well understood. Traditionally, adipocytes within tissues were thought to act as reservoirs of energy, as thermal, or as structural support. In this review, we discuss recent studies revealing the cellular basis of the dynamic development a...

  14. Adiponectin Inhibits Lipolysis in Mouse Adipocytes

    OpenAIRE

    Qiao, Liping; Kinney, Brice; Schaack, Jerome; Shao, Jianhua

    2011-01-01

    OBJECTIVE Adiponectin is an adipocyte-derived hormone that sensitizes insulin and improves energy metabolism in tissues. This study was designed to investigate the direct regulatory effects of adiponectin on lipid metabolism in adipocytes. RESEARCH DESIGN AND METHODS Basal and hormone-stimulated lipolysis were comparatively analyzed using white adipose tissues or primary adipocytes from adiponectin gene knockout and control mice. To further study the underlying mechanisms through which adipon...

  15. 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.

  16. 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. PMID:26571352

  17. 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.

  18. Skin aging: are adipocytes the next target?

    Science.gov (United States)

    Kruglikov, Ilja L; Scherer, Philipp E

    2016-07-01

    Dermal white adipose tissue (dWAT) is increasingly appreciated as a special fat depot. The adipocytes in this depot exert a variety of unique effects on their surrounding cells and can undergo massive phenotypic changes. Significant modulation of dWAT content can be observed both in intrinsically and extrinsically aged skin. Specifically, skin that has been chronically photo-damaged displays a reduction of the dWAT volume, caused by the replacement of adipocytes by fibrotic structures. This is likely to be caused by the recently uncovered process described as "adipocyte-myofibroblast transition" (AMT). In addition, contributions of dermal adipocytes to the skin aging processes are also indirectly supported by spatial correlations between the prevalence of hypertrophic scarring and the appearance of signs of skin aging in different ethnic groups. These observations could elevate dermal adipocytes to prime targets in strategies aimed at counteracting skin aging. PMID:27434510

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

    International Nuclear Information System (INIS)

    Highlights: → Adipocyte dedifferentiation is evident in a significant decrease in typical genes. → Cell proliferation is strongly related to adipocyte dedifferentiation. → Dedifferentiated adipocytes express several lineage-specific genes. → 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

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

    Lifescience Database Archive (English)

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

  6. 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 ...

  7. 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 ...

  8. 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 ...

  9. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-11

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

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

    International Nuclear Information System (INIS)

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

  12. Dynamics of protein secretion during adipocyte differentiation.

    Science.gov (United States)

    Ojima, Koichi; Oe, Mika; Nakajima, Ikuyo; Muroya, Susumu; Nishimura, Takanori

    2016-08-01

    The major functions of adipocytes include both lipid storage and the production of secretory factors. However, the type of proteins released from mouse 3T3-L1 cells during adipocyte differentiation remains poorly understood. We examined the dynamics of secreted proteins during adipocyte differentiation using mass spectrometry (MS) combined with an iTRAQ (®) labeling method that enables the simultaneous analysis of relative protein expression levels. A total of 215 proteins were identified and quantified from approximately 10 000 MS/MS spectra. Of these, approximately 38% were categorized as secreted proteins based on gene ontology classification. Adipokine secretion levels were increased with the progression of differentiation. By contrast, levels of fibril collagen components, such as subunits of type I and III collagens, were decreased during differentiation. Basement membrane components attained their peak levels at day 4 when small lipid droplets accumulated in differentiated 3T3-L1 cells. Simultaneously, peak levels of collagen microfibril components that comprise type V and VI collagen subunits were also observed. Our data demonstrated that extracellular matrix components were predominantly released during the early and middle stages of adipocyte differentiation, with a subsequent increase in the secretion of adipokines. This suggests that 3T3-L1 cells secrete adipokines after their ECM is constructed during adipocyte differentiation. PMID:27516960

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

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. Adipocyte Turnover: Relevance to Human Adipose Tissue Morphology

    OpenAIRE

    Arner, Erik; Westermark, Pål O.; Spalding, Kirsty L.; Britton, Tom; Rydén, Mikael; Frisén, Jonas; Bernard, Samuel; Arner, Peter

    2009-01-01

    OBJECTIVE Adipose tissue may contain few large adipocytes (hypertrophy) or many small adipocytes (hyperplasia). We investigated factors of putative importance for adipose tissue morphology. RESEARCH DESIGN AND METHODS Subcutaneous adipocyte size and total fat mass were compared in 764 subjects with BMI 18–60 kg/m2. A morphology value was defined as the difference between the measured adipocyte volume and the expected volume given by a curved-line fit for a given body fat mass and was related ...

  16. 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.

  17. Human primary adipocytes exhibit immune cell function: adipocytes prime inflammation independent of macrophages.

    Directory of Open Access Journals (Sweden)

    Kees Meijer

    Full Text Available BACKGROUND: Obesity promotes inflammation in adipose tissue (AT and this is implicated in pathophysiological complications such as insulin resistance, type 2 diabetes and cardiovascular disease. Although based on the classical hypothesis, necrotic AT adipocytes (ATA in obese state activate AT macrophages (ATM that then lead to a sustained chronic inflammation in AT, the link between human adipocytes and the source of inflammation in AT has not been in-depth and systematically studied. So we decided as a new hypothesis to investigate human primary adipocytes alone to see whether they are able to prime inflammation in AT. METHODS AND RESULTS: Using mRNA expression, human preadipocytes and adipocytes express the cytokines/chemokines and their receptors, MHC II molecule genes and 14 acute phase reactants including C-reactive protein. Using multiplex ELISA revealed the expression of 50 cytokine/chemokine proteins by human adipocytes. Upon lipopolysaccharide stimulation, most of these adipocyte-associated cytokines/chemokines and immune cell modulating receptors were up-regulated and a few down-regulated such as (ICAM-1, VCAM-1, MCP-1, IP-10, IL-6, IL-8, TNF-α and TNF-β highly up-regulated and IL-2, IL-7, IL-10, IL-13 and VEGF down-regulated. In migration assay, human adipocyte-derived chemokines attracted significantly more CD4+ T cells than controls and the number of migrated CD4+ cells was doubled after treating the adipocytes with LPS. Neutralizing MCP-1 effect produced by adipocytes reduced CD4+ migration by approximately 30%. CONCLUSION: Human adipocytes express many cytokines/chemokines that are biologically functional. They are able to induce inflammation and activate CD4+ cells independent of macrophages. This suggests that the primary event in the sequence leading to chronic inflammation in AT is metabolic dysfunction in adipocytes, followed by production of immunological mediators by these adipocytes, which is then exacerbated by

  18. Lower Total Adipocyte Number but No Evidence for Small Adipocyte Depletion in Patients With Type 2 Diabetes

    OpenAIRE

    Pasarica, Magdalena; Xie, Hui; Hymel, David; Bray, George; Greenway, Frank; Ravussin, Eric; Smith, Steven R.

    2009-01-01

    OBJECTIVE We hypothesized that, compared with obese subjects, patients with type 2 diabetes have a lower total adipocyte number with fewer small adipocytes. RESEARCH DESIGN AND METHODS Abdominal subcutaneous adipose tissue was obtained from lean and obese subjects with or without type 2 diabetes matched for BMI. Adipocyte size was measured by osmium fixation and sizing/counting in a Coulter counter. Adipocyte size and number subdistributions (small, medium, large, and very large) were determi...

  19. 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.

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

    International Nuclear Information System (INIS)

    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.

  1. Impaired Preadipocyte Differentiation Into Adipocytes in Subcutaneous Abdominal Adipose of PCOS-Like Female Rhesus Monkeys

    OpenAIRE

    Keller, Erica; Chazenbalk, Gregorio D.; Aguilera, Paul; Madrigal, Vanessa; Grogan, Tristan; Elashoff, David; Daniel A Dumesic; David H Abbott

    2014-01-01

    Metabolic characteristics of polycystic ovary syndrome women and polycystic ovary syndrome-like, prenatally androgenized (PA) female monkeys worsen with age, with altered adipogenesis of sc abdominal adipose potentially contributing to age-related adverse effects on metabolism. This study examines whether adipocyte morphology and gene expression in sc abdominal adipose differ between late reproductive-aged PA female rhesus monkeys compared with age-matched controls (C). Subcutaneous abdominal...

  2. Aging Leads to a Programmed Loss of Brown Adipocytes in Murine Subcutaneous White Adipose Tissue

    OpenAIRE

    Rogers, Nicole H; Landa, Alejandro; Park, Seongjoon; Smith, Roy G.

    2012-01-01

    Insulin sensitivity deteriorates with age, but mechanisms remain unclear. Age-related changes in the function of subcutaneous white adipose tissue (sWAT) are less characterized than those in visceral WAT. We hypothesized that metabolic alterations in sWAT, which in contrast to epididymal WAT, harbors a sub-population of energy dissipating UCP1+ brown adipocytes, promote age-dependent progression towards insulin resistance. Indeed, we show that a predominant consequence of aging in murine sWAT...

  3. Critical role for cytosolic group IVA phospholipase A2 in early adipocyte differentiation and obesity.

    Science.gov (United States)

    Peña, Lucía; Meana, Clara; Astudillo, Alma M; Lordén, Gema; Valdearcos, Martín; Sato, Hiroyasu; Murakami, Makoto; Balsinde, Jesús; Balboa, María A

    2016-09-01

    Adipogenesis is the process of differentiation of immature mesenchymal stem cells into adipocytes. Elucidation of the mechanisms that regulate adipocyte differentiation is key for the development of novel therapies for the control of obesity and related comorbidities. Cytosolic group IVA phospholipase A2 (cPLA2α) is the pivotal enzyme in receptor-mediated arachidonic acid (AA) mobilization and attendant eicosanoid production. Using primary multipotent cells and cell lines predetermined to become adipocytes, we show here that cPLA2α displays a proadipogenic function that occurs very early in the adipogenic process. Interestingly, cPLA2α levels decrease during adipogenesis, but cPLA2α-deficient preadipocytes exhibit a reduced capacity to differentiate into adipocytes, which affects early and terminal adipogenic transcription factors. Additionally, the absence of the phospholipase alters proliferation and cell-cycle progression that takes place during adipogenesis. Preconditioning of preadipocytes with AA increases the adipogenic capacity of these cells. Moreover, animals deficient in cPLA2α show resistance to obesity when fed a high fat diet that parallels changes in the expression of adipogenic transcription factors of the adipose tissue. Collectively, these results show that preadipocyte cPLA2α activation is a hitherto unrecognized factor for adipogenesis in vitro and in vivo. PMID:27317983

  4. 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...

  5. 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.

  6. 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.

  7. 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

  8. Differential regulation of pro- and antiapoptotic proteins in fish adipocytes during hypoxic conditions.

    Science.gov (United States)

    Ekambaram, Padmini; Parasuraman, Parimala; Jayachandran, Tharani

    2016-06-01

    Worldwide, the frequencies and magnitudes of hypoxic events in estuarine waters have increased considerably over the past two decades. Fish populations are suitable indicators for the assessment of quality of aquatic ecosystems and often comprise a variety of adaptation systems by triggering oxidants, antioxidants and hypoxia-responsive signaling proteins. Signaling pathway may lead to cell survival or cell death which is fine-tuned by both positive and negative factors, which includes hypoxia-inducible factor-1α (HIF1α), heat-shock protein-70 (HSP70), phospho-c-Jun N-terminal kinase 1/2 (p-JNK1/2) and apoptosis signal-regulating kinase-1 (ASK1). In the present study, we attempt to determine stress-mediated signaling changes and molecular mechanism behind the cell survival by comparing adipocytes of fish from field hypoxic condition and laboratory-induced hypoxic condition (in vitro hypoxia). Comparison of field and laboratory studies in fish adipocytes showed differential expression of HIF1α, HSP70, p-JNK1/2 and ASK1 with altered oxidants and antioxidants. Further, the results also suggest that in vitro hypoxic conditions mimic field hypoxic conditions. Trends of hypoxia response were same in in vitro hypoxia of control adipocytes as in Ennore estuary, and hypoxia response was more pronounced in the test adipocytes under in vitro hypoxic condition. Results of the present work suggest that hypoxia is the major crusade of water pollutants affecting fish by differential regulation of pro- and antiapoptotic proteins probably through HSP70. This may play a vital role by providing cytoprotection in pollutant-induced stressed fish adipocytes substantiated by the in vitro hypoxic studies. PMID:26744268

  9. 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.

  10. Effects of parabens on adipocyte differentiation.

    Science.gov (United States)

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

    2013-01-01

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

  11. 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.

  12. A novel automated image analysis method for accurate adipocyte quantification

    OpenAIRE

    Osman, Osman S.; Selway, Joanne L; Kępczyńska, Małgorzata A; Stocker, Claire J.; O’Dowd, Jacqueline F; Cawthorne, Michael A.; Arch, Jonathan RS; Jassim, Sabah; Langlands, Kenneth

    2013-01-01

    Increased adipocyte size and number are associated with many of the adverse effects observed in metabolic disease states. While methods to quantify such changes in the adipocyte are of scientific and clinical interest, manual methods to determine adipocyte size are both laborious and intractable to large scale investigations. Moreover, existing computational methods are not fully automated. We, therefore, developed a novel automatic method to provide accurate measurements of the cross-section...

  13. Analysis and Isolation of Adipocytes by Flow Cytometry

    OpenAIRE

    Majka, Susan M.; Miller, Heidi L.; Helm, Karen M.; Acosta, Alistaire S.; Childs, Christine R.; Kong, Raymond; Klemm, Dwight J.

    2014-01-01

    Analysis and isolation of adipocytes via flow cytometry is particularly useful to study their biology. However, the adoption of this technology has often been hampered by the presence of stromal/vascular cells in adipocyte fractions prepared from collagenase-digested adipose tissue. Here, we describe a multistep staining method and gating strategy that effectively excludes stromal contaminants. Initially, we set a gate optimized to the size and internal complexity of adipocytes. Exclusion of ...

  14. Adipocyte Induction of Preadipocyte Differentiation in a Gradient Chamber

    OpenAIRE

    Lai, Ning; Sims, James K; Jeon, Noo Li; Lee, Kyongbum

    2012-01-01

    Adipose tissue expansion involves enlargement of mature adipocytes and the formation of new adipocytes through the differentiation of locally resident preadipocytes. Factors released by the enlarged adipocytes are potential cues that induce the differentiation of the preadipocytes. Currently, there are limited options to investigate these cues in isolation from confounding systemic influences. A gradient generating microfluidic channel-based cell culture system was designed to enable solution...

  15. Cadmium modulates adipocyte functions in metallothionein-null mice

    International Nuclear Information System (INIS)

    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−/−) mice, which cannot form atoxic Cd–MT complexes and are used for evaluating Cd as free ions, and wild type (MT+/+) mice. Cd administration more significantly reduced the adipocyte size of MT−/− mice than that of MT+/+ mice. Cd exposure also induced macrophage recruitment to WAT with an increase in the expression level of Ccl2 (MCP-1) in the MT−/− 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

  16. 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.

  17. Free fatty acids, lipopolysaccharide and IL-1α induce adipocyte manganese superoxide dismutase which is increased in visceral adipose tissues of obese rodents.

    Directory of Open Access Journals (Sweden)

    Sabrina Krautbauer

    Full Text Available Excess fat storage in adipocytes is associated with increased generation of reactive oxygen species (ROS and impaired activity of antioxidant mechanisms. Manganese superoxide dismutase (MnSOD is a mitochondrial enzyme involved in detoxification of ROS, and objective of the current study is to analyze expression and regulation of MnSOD in obesity. MnSOD is increased in visceral but not subcutaneous fat depots of rodents kept on high fat diets (HFD and ob/ob mice. MnSOD is elevated in visceral adipocytes of fat fed mice and exposure of differentiating 3T3-L1 cells to lipopolysaccharide, IL-1α, saturated, monounsaturated and polyunsaturated free fatty acids (FFA upregulates its level. FFA do not alter cytochrome oxidase 4 arguing against overall induction of mitochondrial enzymes. Upregulation of MnSOD in fat loaded cells is not mediated by IL-6, TNF or sterol regulatory element binding protein 2 which are induced in these cells. MnSOD is similarly abundant in perirenal fat of Zucker diabetic rats and non-diabetic animals with similar body weight and glucose has no effect on MnSOD in 3T3-L1 cells. To evaluate whether MnSOD affects adipocyte fat storage, MnSOD was knocked-down in adipocytes for the last three days of differentiation and in mature adipocytes. Knock-down of MnSOD does neither alter lipid storage nor viability of these cells. Heme oxygenase-1 which is induced upon oxidative stress is not altered while antioxidative capacity of the cells is modestly reduced. Current data show that inflammation and excess triglyceride storage raise adipocyte MnSOD which is induced in epididymal adipocytes in obesity.

  18. Obestatin as a regulator of adipocyte metabolism and adipogenesis

    OpenAIRE

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

    2011-01-01

    Abstract The role of obestatin, a 23-amino-acid peptide encoded by the ghrelin gene, on the control of the metabolism of pre-adipocyte and adipocytes as well as on adipogenesis was determined. For in vitro assays, pre-adipocyte and adipocyte 3T3-L1 cells were used to assess the obestatin effect on cell metabolism and adipogenesis based on the regulation of the key enzymatic nodes, Akt and AMPK and their downstream targets. For in vivo assays, white adipose tissue (WAT) was obtained from male ...

  19. 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.

  20. Deficiency of Angiotensin Type 1a Receptors in Adipocytes Reduces Differentiation and Promotes Hypertrophy of Adipocytes in Lean Mice

    OpenAIRE

    Putnam, Kelly; Batifoulier-Yiannikouris, Frederique; Bharadwaj, Kalyani G.; Lewis, Eboni; Karounos, Michael; Daugherty, Alan; Cassis, Lisa A.

    2012-01-01

    Adipocytes express angiotensin receptors, but the direct effects of angiotensin II (AngII) stimulating this cell type are undefined. Adipocytes express angiotensin type 1a receptor (AT1aR) and AT2R, both of which have been implicated in obesity. In this study, we determined the effects of adipocyte AT1aR deficiency on adipocyte differentiation and the development of obesity in mice fed low-fat (LF) or high-fat (HF) diets. Mice expressing Cre recombinase under the control of the aP2 promoter w...

  1. Adipocyte hypertrophy, inflammation and fibrosis characterize subcutaneous adipose tissue of healthy, non-obese subjects predisposed to type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    A M Josefin Henninger

    Full Text Available BACKGROUND: The adipose tissue is important for development of insulin resistance and type 2 diabetes and adipose tissue dysfunction has been proposed as an underlying cause. In the present study we investigated presence of adipocyte hypertrophy, and gene expression pattern of adipose tissue dysfunction in the subcutaneous adipose tissue of healthy, non-obese subjects predisposed to type 2 diabetes compared to matched control subjects with no known genetic predisposition for type 2 diabetes. METHOD: Seventeen healthy and non-obese subjects with known genetic predisposition for type 2 diabetes (first-degree relatives, FDRs and 17 control subjects were recruited. The groups were matched for gender and BMI and had similar age. Glucose tolerance was determined by an oral glucose tolerance test and insulin sensitivity was calculated using HOMA-index. Blood samples were collected and subcutaneous abdominal adipose tissue biopsies obtained for gene expression analysis and adipocyte cell size measurement. RESULTS: Our findings show that, in spite of similar age, BMI and percent body fat, FDRs displayed adipocyte hypertrophy, as well as higher waist/hip ratio, fasting insulin levels, HOMA-IR and serum triglycerides. Adipocyte hypertrophy in the FDR group, but not among controls, was associated with measures of impaired insulin sensitivity. The adipocyte hypertrophy was accompanied by increased inflammation and Wnt-signal activation. In addition, signs of tissue remodeling and fibrosis were observed indicating presence of early alterations associated with adipose tissue dysfunction in the FDRs. CONCLUSION: Genetic predisposition for type 2 diabetes is associated with impaired insulin sensitivity, adipocyte hypertrophy and other markers of adipose tissue dysfunction. A dysregulated subcutaneous adipose tissue may be a major susceptibility factor for later development of type 2 diabetes.

  2. 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.

  3. 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.

  4. 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.

  5. Differentiation of preadipocytes and mature adipocytes requires PSMB8

    OpenAIRE

    Hideki Arimochi; Yuki Sasaki; Akiko Kitamura; Koji Yasutomo

    2016-01-01

    The differentiation of adipocytes is tightly regulated by a variety of intrinsic molecules and also by extrinsic molecules produced by adjacent cells. Dysfunction of adipocyte differentiation causes lipodystrophy, which impairs glucose and lipid homeostasis. Although dysfunction of immunoproteasomes causes partial lipodystrophy, the detailed molecular mechanisms remain to be determined. Here, we demonstrate that Psmb8, a catalytic subunit for immunoproteasomes, directly regulates the differen...

  6. 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...

  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. Disruption of cell-matrix interactions by heparin enhances mesenchymal progenitor adipocyte differentiation

    International Nuclear Information System (INIS)

    Differentiation of marrow-derived mesenchymal progenitors to either the osteoblast or adipocyte lineage is reciprocally regulated. Factors that promote osteoblastogenesis inhibit adipogenesis, while adipogenic factors are inhibitory to osteoblast differentiation. Heparin, a soluble glycosaminoglycan, inhibits bone formation in vivo and osteoblast cell differentiation and function in vitro, and has been shown to promote adipocyte differentiation. To elucidate the role that heparin plays in the adipogenic induction of murine mesenchymal progenitors, we studied immortalized marrow stromal cells (IM-MSC), the MSC cell line, ST2, and 3T3L1 pre-adipocytes. Heparin alone was not sufficient to induce adipogenesis, but enhanced the induction under a variety of adipogenic cocktails. This effect was both dose- and time-dependent. Heparin showed a positive effect at concentrations > 0. 1 μg/ml when applied before day 3 during the induction course. Heparin's effect on adipogenesis was independent of cell proliferation, cell density, and extracellular lipid. This effect is likely related to the unique structure of heparin because another polyanionic glycosaminoglycan, dextran sulfate, did not promote adipogenic differentiation. Heparin treatment altered morphology and adhesion characteristics of progenitor cells, resulting in cell rounding and aggregation. As well, heparin counteracted the known inhibitory effect of fibronectin on adipogenesis and decreased basal focal adhesion kinase and paxillin phosphorylation. We conclude that heparin-mediated disruption of cell-matrix adhesion enhances adipogenic potential

  9. Cadmium reduces adipocyte size and expression levels of adiponectin and Peg1/Mest in adipose tissue

    International Nuclear Information System (INIS)

    Adipose tissue dysfunction has been associated with diabetogenic effects. The effects of repeated Cd exposure on adipocytes remain largely unknown. We administered Cd at doses of 0, 5, 10, and 20 μmol/kg bw sc for 2 weeks (3.5 times/week) to mice and assessed the possible alteration of epididymal white adipose tissue (WAT), including histological difference, adipocyte differentiation and functional capacity. Whereas hepatic weight did not differ between the control and Cd-exposed groups, WAT weight, as well as adipose cell mass, significantly decreased in a dose-dependent manner in Cd-treated mice. The Cd concentration in WAT significantly increased in Cd-treated groups after 2 weeks of exposure. Next, we examined the effects of Cd on adipocyte differentiation and hypertrophy. Cd exposure significantly decreased the paternally expressed gene 1/Mesoderm-specific transcript mRNA expression levels. Both peroxisome proliferator-activated receptor γ2 and CCAAT/enhancer-binding protein α mRNA expression levels in WAT tended to decrease in the Cd-treated groups. Next, we determined the effects of Cd exposure on the mRNA expression levels of adipose-derived hormones, such as adiponectin and resistin. The adiponectin mRNA expression level in WAT decreased after both 6 h and 2 weeks of exposure to a high dose of Cd, and the reduction in resistin mRNA expression levels was observed after 2 weeks of exposure. These results suggest that Cd exposure causes abnormal adipocyte differentiation, expansion, and function, which might lead to development of insulin resistance, hypertension, and cardiovascular disease.

  10. 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.

  11. Angiotensinogen gene silencing reduces markers of inflammation and lipid accumulation in adipocytes

    Directory of Open Access Journals (Sweden)

    Wenting eXin

    2013-03-01

    Full Text Available Inflammatory adipokines secreted from adipose tissue are major contributors to obesity-associated inflammation and other metabolic dysfunctions. We and others have recently documented the contribution of adipose tissue renin-angiotensin system (RAS to the pathogenesis of obesity, inflammation and insulin resistance. We hypothesized that adipocyte-derived angiotensinogen (Agt plays a critical role in adipogenesis and/or lipogenesis as well as inflammation. This was tested using 3T3-L1 adipocytes, stably transfected with Agt-shRNA or scrambled Sc-shRNAcas a control. Transfected preadipocytes were differentiated and used to investigate the role of adipose Agt through microarray and PCR analyses and adipokine profiling. As expected, Agt gene silencing significantly reduced the expression of Agt and its hormone product angiotensin II (Ang II, as well as lipid accumulation in 3T3-L1 adipocytes. Microarray studies identified several genes involved in lipid metabolism and inflammatory pathways which were down-regulated by Agt gene inactivation, such as glycerol-3-phosphate dehydrogenase 1 (Gpd1, serum amyloid A 3 (Saa3, nucleotide-binding oligomerization domain containing 1 (Nod1 and signal transducer and activator of transcription 1 (Stat1. Mouse adipogenesis PCR arrays revealed lower expression levels of adipogenic/lipogenic genes such as peroxisome proliferator activated receptor gamma (Pparg, sterol regulatory element binding transcription factor 1 (Srebf1, adipogenin (Adig, and fatty acid binding protein 4 (Fabp4. Further, silencing of Agt gene significantly lowered expression of pro-inflammatory adipokines including interleukin-6 (IL-6, tumor necrosis factor-alpha (TNF-α, and monocyte chemotactic protein-1 (MCP-1. In conclusion, this study directly demonstrates critical effects of Agt in adipocyte metabolism and inflammation and further support a potential role for adipose Agt in the pathogenesis of obesity-associated metabolic alterations.

  12. 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.

  13. 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. PMID:25878060

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Bao G Vu

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

  16. Regulation of vascular tone by adipocytes

    Directory of Open Access Journals (Sweden)

    Van de Voorde Johan

    2011-03-01

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

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

    OpenAIRE

    Oosterveer, Maaike H.; Koolman, Anniek H; de Boer, Pieter T; Bos, Trijnie; Bleeker, Aycha; Bloks, Vincent W.; Kuipers, Folkert; Sauer, Pieter J. J.; van Dijk, Gertjan

    2011-01-01

    Background: Overactivity and/or dysregulation of the endocannabinoid system (ECS) contribute to development of obesity. In vitro studies indicate a regulatory role for the cannabinoid receptor 1 (CB1) in adipocyte function and CB1-receptor deficient (CB1-/-) mice are resistant to high fat 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 q...

  18. In vivo identification of bipotential adipocyte progenitors recruited by β3-adrenoceptor activation and high fat feeding

    OpenAIRE

    Lee, Yun-Hee; Petkova, Anelia P.; Mottillo, Emilio P.; Granneman, James G.

    2012-01-01

    Nutritional and pharmacological stimuli can dramatically alter the cellular phenotypes in white adipose tissue (WAT). Utilizing genetic lineage tracing techniques, we demonstrate that brown adipocytes (BA) that are induced by β3-adrenergic receptor activation in abdominal WAT arise from the proliferation and differentiation of cells expressing platelet-derived growth factor receptor alpha (PDGFRα), CD34 and Sca1 (PDGFRα+ cells). PDGFRα+ cells have a unique morphology in which extended process...

  19. Expression of miR-199a-3p in human adipocytes is regulated by free fatty acids and adipokines.

    Science.gov (United States)

    Gu, Nan; You, Lianghui; Shi, Chunmei; Yang, Lei; Pang, Lingxia; Cui, Xianwei; Ji, Chenbo; Zheng, Wen; Guo, Xirong

    2016-08-01

    Obesity is associated with a notable risk for disease, including risk of cardiovascular disorders, type 2 diabetes mellitus (T2DM) and hypertension. Adipose tissue modulates the metabolism by releasing free fatty acids (FFAs) and adipokines, including leptin, resistin, tumor necrosis factor-α (TNF-α) and interleukin 6 (IL‑6). Altered secretion patterns of FFAs and adipokines have been demonstrated to result in obesity‑associated insulin resistance (IR) and inflammatory responses. MicroRNA-199a-3p (miR)-199a-3p expression is significantly induced in differentiated human adipose-derived mesenchymal stem cells and indicates the association with T2DM. However, the association between miR-199a-3p levels in adipocytes and obesity‑associated IR, as well as inflammatory responses remains to be elucidated. The present study observed an elevation of miR‑199a‑3p expression level in mature human adipocytes (visceral) compared with pre-adipocytes. In addition, miR‑199a‑3p expression was higher in visceral adipose deposits from obese subjects. FFA, TNF-α, IL‑6 and leptin significantly induced miR‑199a‑3p expression in mature human adipocytes, while resistin had the opposite effect. miR‑199a‑3p may represent a factor in the modulation of obesity‑associated IR and inflammatory responses. PMID:27279151

  20. Dietary Cholesterol Promotes Adipocyte Hypertrophy and Adipose Tissue Inflammation in Visceral, But Not Subcutaneous, Fat in Monkeys

    Science.gov (United States)

    Chung, Soonkyu; Cuffe, Helen; Marshall, Stephanie M.; McDaniel, Allison L.; Ha, Jung-Heun; Kavanagh, Kylie; Hong, Cynthia; Tontonoz, Peter; Temel, Ryan E.; Parks, John S

    2014-01-01

    Objective Excessive caloric intake is associated with obesity and adipose tissue dysfunction. However, the role of dietary cholesterol in this process is unknown. The aim of this study was to determine whether increasing dietary cholesterol intake alters adipose tissue cholesterol content, adipocyte size, and endocrine function in nonhuman primates. Approach and Results Age-matched, male African Green monkeys (n=5 per group) were assigned to one of three diets containing 0.002 (Lo), 0.2 (Med) or 0.4 (Hi) mg cholesterol/Kcal. After 10 weeks of diet feeding, animals were euthanized for adipose tissue, liver, and plasma collection. With increasing dietary cholesterol, free cholesterol (FC) content and adipocyte size increased in a step-wise manner in visceral, but not subcutaneous fat, with a significant association between visceral adipocyte size and FC content (r2=0.298; n=15; p=0.035). In visceral fat, dietary cholesterol intake was associated with: 1) increased pro-inflammatory gene expression and macrophage recruitment, 2) decreased expression of genes involved in cholesterol biosynthesis and lipoprotein uptake, and 3) increased expression of proteins involved in FC efflux. Conclusions Increasing dietary cholesterol selectively increases visceral fat adipocyte size, FC and macrophage content, and proinflammatory gene expression in nonhuman primates. Visceral fat cells appear to compensate for increased dietary cholesterol by limiting cholesterol uptake/synthesis and increasing FC efflux pathways. PMID:24969772

  1. 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

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

    Lifescience Database Archive (English)

    Full Text Available Pol.Adp.20.AllAg.Adipocytes hg19 RNA polymerase Adipocyte Adipocytes SRX682084,SRX6...82086,SRX682083,SRX682085 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.Adp.20.AllAg.Adipocytes.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.50.AllAg.Pre-adipocytes hg19 TFs and others Adipocyte Pre-adipocytes SRX760...967,SRX760968,SRX760971,SRX760969,SRX760970 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Adp.50.AllAg.Pre-adipocytes.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available His.Adp.20.AllAg.Pre-adipocytes hg19 Histone Adipocyte Pre-adipocytes SRX760962,SRX...760966,SRX760963,SRX760965,SRX760964 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.Adp.20.AllAg.Pre-adipocytes.bed ...

  11. File list: ALL.Adp.50.AllAg.Adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Adp.50.AllAg.Adipocytes hg19 All antigens Adipocyte Adipocytes SRX682084,SRX682...086,SRX027402,SRX682085,SRX682083,SRX027401,SRX027400,SRX027404,SRX027403 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Adp.50.AllAg.Adipocytes.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available ALL.Adp.10.AllAg.Adipocytes hg19 All antigens Adipocyte Adipocytes SRX027402,SRX682...086,SRX682084,SRX027400,SRX682085,SRX682083,SRX027403,SRX027401,SRX027404 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Adp.10.AllAg.Adipocytes.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available His.Adp.50.AllAg.Pre-adipocytes hg19 Histone Adipocyte Pre-adipocytes SRX760966,SRX...760964,SRX760963,SRX760965,SRX760962 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.Adp.50.AllAg.Pre-adipocytes.bed ...

  14. File list: Pol.Adp.10.AllAg.Adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Adp.10.AllAg.Adipocytes hg19 RNA polymerase Adipocyte Adipocytes SRX682086,SRX6...82084,SRX682085,SRX682083 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.Adp.10.AllAg.Adipocytes.bed ...

  15. File list: Oth.Adp.05.AllAg.Adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.05.AllAg.Adipocytes hg19 TFs and others Adipocyte Adipocytes SRX027402,SRX0...27403,SRX027401 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Adp.05.AllAg.Adipocytes.bed ...

  16. File list: Oth.Adp.50.AllAg.Adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.50.AllAg.Adipocytes hg19 TFs and others Adipocyte Adipocytes SRX027402,SRX0...27401,SRX027403 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Adp.50.AllAg.Adipocytes.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.20.AllAg.Pre-adipocytes hg19 TFs and others Adipocyte Pre-adipocytes SRX760...967,SRX760968,SRX760971,SRX760969,SRX760970 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Adp.20.AllAg.Pre-adipocytes.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.10.AllAg.Pre-adipocytes hg19 TFs and others Adipocyte Pre-adipocytes SRX760...968,SRX760967,SRX760971,SRX760969,SRX760970 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Adp.10.AllAg.Pre-adipocytes.bed ...

  19. File list: ALL.Adp.05.AllAg.Adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Adp.05.AllAg.Adipocytes hg19 All antigens Adipocyte Adipocytes SRX027402,SRX027...403,SRX027400,SRX682086,SRX682084,SRX682083,SRX682085,SRX027401,SRX027404 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Adp.05.AllAg.Adipocytes.bed ...

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

    Full Text Available NoD.Adp.10.AllAg.Brown_adipocytes mm9 No description Adipocyte Brown adipocytes htt...p://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Adp.10.AllAg.Brown_adipocytes.bed ...

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

    Lifescience Database Archive (English)

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

  11. 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 ...

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

  14. 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 ...

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

    Full Text Available Pol.Adp.10.AllAg.Brown_adipocytes mm9 RNA polymerase Adipocyte Brown adipocytes SRX...800010,SRX800016,SRX800017 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Adp.10.AllAg.Brown_adipocytes.bed ...

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

    Lifescience Database Archive (English)

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

  5. File list: Oth.Adp.05.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.05.AllAg.White_adipocytes mm9 TFs and others Adipocyte White adipocytes SRX... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Adp.05.AllAg.White_adipocytes.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available Pol.Adp.10.AllAg.White_adipocytes mm9 RNA polymerase Adipocyte White adipocytes SRX...800011 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Adp.10.AllAg.White_adipocytes.bed ...

  7. File list: NoD.Adp.50.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

    Full Text Available InP.Adp.05.AllAg.White_adipocytes mm9 Input control Adipocyte White adipocytes SRX9...97757,SRX821800,SRX821801,SRX268023,SRX821799 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Adp.05.AllAg.White_adipocytes.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available Pol.Adp.50.AllAg.White_adipocytes mm9 RNA polymerase Adipocyte White adipocytes SRX...800011 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Adp.50.AllAg.White_adipocytes.bed ...

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

    Lifescience Database Archive (English)

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

  11. File list: InP.Adp.50.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Adp.50.AllAg.White_adipocytes mm9 Input control Adipocyte White adipocytes SRX2...68023,SRX997757,SRX821800,SRX821801,SRX821799 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Adp.50.AllAg.White_adipocytes.bed ...

  12. File list: Oth.Adp.50.AllAg.White_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.50.AllAg.White_adipocytes mm9 TFs and others Adipocyte White adipocytes SRX... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Adp.50.AllAg.White_adipocytes.bed ...

  13. 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].

  14. 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.

  15. Suppression of adipocyte hypertrophy by polymethoxyflavonoids isolated from Kaempferia parviflora.

    Science.gov (United States)

    Okabe, Yui; Shimada, Tsutomu; Horikawa, Takumi; Kinoshita, Kaoru; Koyama, Kiyotaka; Ichinose, Koji; Aburada, Masaki; Takahashi, Kunio

    2014-05-15

    We previously demonstrated that ethyl acetate extracts of Kaempferia parviflora Wall. Ex Baker (KPE) improve insulin resistance in TSOD mice and showed that its components induce differentiation and adipogenesis in 3T3-L1 preadipocytes. The present study was undertaken to examine whether KPE and its isolated twelve components suppress further lipid accumulation in 3T3-L1 mature adipocytes. KPE reduced intracellular triglycerides in mature adipocytes, as did two of its components, 3,5,7,3',4'-pentamethoxyflavone and 5,7,4'-trimethoxyflavone. Shrinkage of lipid droplets in mature adipocytes was observed, and mRNA expression levels of adipose tissue triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) were up-regulated by these two polymethoxyflavonoids (PMFs). Furthermore, the protein expression level of ATGL and the release level of glycerol into the cell culture medium increased. In contrast, the peroxisome proliferator-activated receptor γ (PPARγ) agonist, troglitazone, did not decrease intracellular triglycerides in mature adipocytes, and the mRNA expression level of PPARγ was not up-regulated in mature adipocytes treated with the two active PMFs. Therefore, suppression of lipid accumulation in mature adipocytes is unlikely to be enhanced by transcriptional activation of PPARγ. These results suggest that KPE and its active components enhance lipolysis in mature adipocytes by activation of ATGL and HSL independent of PPARγ transcription, thus preventing adipocyte hypertrophy. On the other hand, the full hydroxylated flavonoid quercetin did not show the suppressive effects of lipid accumulation in mature adipocyte in the same conditions. Consequently, methoxy groups in the flavones are important for the activity. PMID:24629599

  16. 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.

  17. Adipocyte macrophage colony-stimulating factor is a mediator of adipose tissue growth.

    OpenAIRE

    Levine, J. A.; Jensen, M.D.; Eberhardt, N L; O'Brien, T.

    1998-01-01

    Adipose tissue growth results from de novo adipocyte recruitment (hyperplasia) and increased size of preexisting adipocytes. Adipocyte hyperplasia accounts for the severalfold increase in adipose tissue mass that occurs throughout life, yet the mechanism of adipocyte hyperplasia is unknown. We studied the potential of macrophage colony-stimulating factor (MCSF) to mediate adipocyte hyperplasia because of the profound effects MCSF exerts on pluripotent cell recruitment and differentiation in o...

  18. Simvastatin inhibits ox-LDL-induced inflammatory adipokines secretion via amelioration of ER stress in 3T3-L1 adipocyte.

    Science.gov (United States)

    Wu, Zhi-hong; Chen, Ya-qin; Zhao, Shui-ping

    2013-03-01

    Adipocytes behave as a rich source of pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1). Endoplasmic reticulum (ER) stress in adipocytes can alter adipokines secretion and induce inflammation. The aim of this study is to evaluate the effect of simvastatin on the ox-LDL-induced ER stress and expression and secretion of TNF-α and MCP-1 in 3T3-L1 adipocytes. Differentiated adipocytes were treated with various concentrations of ox-LDL (0-100 μg/ml) for 24h with or without simvastatin pre-treatment. The protein expressions of ER stress markers, glucose-regulated protein 78 (GRP78) and C/EBP homology protein (CHOP), were determined by Western blot analysis. The mRNA expressions of TNF-α and MCP-1 were measured by real-time PCR. The protein release of TNF-α and MCP-1 in culture medium were evaluated by ELISA. Ox-LDL treatment led to significant up-regulation of GRP78 and CHOP in dose-dependent manner. The expressions of TNF-α and MCP-1 were dose-dependently increased at mRNA and protein levels after ox-LDL intervention. The effects of ox-LDL on adipocytes were abolished by pre-treatment with 4-phenylbutyrate (4-PBA), a chemical chaperone known to ameliorate ER stress. Simvastatin could inhibit ox-LDL-induced ER stress and reduce the expression of TNF-α and MCP-1 at mRNA and protien level in dose dependent manner. In conclusion, ox-LDL can stimulate the expression and secretion of TNF-α and MCP-1 through its activation of ER stress in adipocytes. Simvastatin might exert direct anti-inflammatory effects in adipocytes through amelioration of ER stress.

  19. Feed withdrawal abate regimens lipodystrophy and metabolic syndrome symptoms, such as glucose tolerance, are associated with the diameter of retroperitoneal adipocytes in rats.

    Science.gov (United States)

    He, Mao L; Sharma, Ranjana; Mir, Priya S; Okine, Erasmus; Dodson, Michael V

    2010-02-01

    Adipocyte numbers were increased by feed withdrawal (FW) regimens in cattle; thus, the effect of FW regimens was studied in male Wistar and fa/fa obese rats, as models for humans, in 2 completely randomized design experiments to abate lipodystrophy and progression of metabolic syndrome symptoms. The hypothesis was that application of FW regimens could alter adipose tissue cellularity, adipocyte size, and affect area under the curve (AUC) during glucose tolerance tests. Objectives were to determine associations among retroperitoneal and inguinal adipose tissue adipocyte number, diameter, and AUC, as affected by fortnightly or a single (at age 50 days) 24-hour FW regimen. Adipocyte marker peroxisome proliferator-activated receptor gamma expression was elevated (P = .054) in the retroperitoneal tissue of fa/fa obese rats in the fortnightly FW treatment because of a 13% increase in tissue cell density (cells per gram; P = .13). Average cell diameter in retroperitoneal adipose and AUC were negatively corelated. Regression analyses after including the square of average cell diameter indicated that average retroperitoneal adipocyte diameter (between 65 and 135 mum) and the AUC were related in a quadratic manner (R(2) = 0.14; n = 49; P = .03) for Wistar rats. Cell number of the inguinal and retroperitoneal adipocytes tended to be positively corelated (r = 0.24; P = .09 and r = 0.26; P = .07, n = 49, respectively) to the AUC and are indexes of adiposity. Results suggest that maintenance of retroperitoneal adipocytes at appropriate diameters may control progression of metabolic syndrome symptoms such as glucose tolerance. PMID:20226998

  20. Cytoprotective role of the fatty acid binding protein 4 against oxidative and endoplasmic reticulum stress in 3T3-L1 adipocytes

    Directory of Open Access Journals (Sweden)

    Kazuaki Kajimoto

    2014-01-01

    Full Text Available The fatty acid binding protein 4 (FABP4, one of the most abundant proteins in adipocytes, has been reported to have a proinflammatory function in macrophages. However, the physiological role of FABP4, which is constitutively expressed in adipocytes, has not been fully elucidated. Previously, we demonstrated that FABP4 was involved in the regulation of interleukin-6 (IL-6 and vascular endothelial growth factor (VEGF production in 3T3-L1 adipocytes. In this study, we examined the effects of FABP4 silencing on the oxidative and endoplasmic reticulum (ER stress in 3T3-L1 adipocytes. We found that the cellular reactive oxygen species (ROS and 8-nitro-cyclic GMP levels were significantly elevated in the differentiated 3T3-L1 adipocytes transfected with a small interfering RNA (siRNA against Fabp4, although the intracellular levels or enzyme activities of antioxidants including reduced glutathione (GSH, superoxide dismutase (SOD and glutathione S-transferase A4 (GSTA4 were not altered. An in vitro evaluation using the recombinant protein revealed that FABP4 itself functions as a scavenger protein against hydrogen peroxide (H2O2. FABP4-knockdown resulted in a significant lowering of cell viability of 3T3-L1 adipocytes against H2O2 treatment. Moreover, four kinds of markers related to the ER stress response including the endoplasmic reticulum to nucleus signaling 1 (Ern1, the signal sequence receptor α (Ssr1, the ORM1-like 3 (Ormdl3, and the spliced X-box binding protein 1 (Xbp1s, were all elevated as the result of the knockdown of FABP4. Consequently, FABP4 might have a new role as an antioxidant protein against H2O2 and contribute to cytoprotection against oxidative and ER stress in adipocytes.

  1. Utility of transplantation in studying adipocyte biogenesis and function

    OpenAIRE

    Zhang, Yiying

    2009-01-01

    Adipose tissue plays important roles in the regulation of energy homeostasis and metabolism. Two features distinguish adipose tissue from other organs - the ability to greatly expand its mass, via increases in cell size and/or number, and the wide anatomical distribution. While adipose tissue function is greatly affected by adipocyte size and anatomic location, regulations of adipocyte size, number, and body fat distribution are poorly understood. Transplantation of either mature adipose tiss...

  2. Remodeling of lipid droplets during lipolysis and growth in adipocytes

    OpenAIRE

    Paar, Margret; Jüngst, Christian; Steiner, Noemi; Magnes, Christoph; Sinner, Frank; Kolb, Dagmar; Lass, Achim; Zimmermann, Robert; Zumbusch, Andreas; Kohlwein, Sepp; Wolinski, Heimo

    2012-01-01

    Synthesis, storage, and turnover of triacylglycerols (TAGs) in adipocytes are critical cellular processes to maintain lipid and energy homeostasis in mammals. TAGs are stored in metabolically highly dynamic lipid droplets (LDs), which are believed to undergo fragmentation and fusion under lipolytic and lipogenic conditions, respectively. Time lapse fluorescence microscopy showed that stimulation of lipolysis in 3T3-L1 adipocytes causes progressive shrinkage and almost complete degradation of ...

  3. Differential Chemokine Signature between Human Preadipocytes and Adipocytes

    Science.gov (United States)

    Ignacio, Rosa Mistica C.; Gibbs, Carla R.; Lee, Eun-Sook

    2016-01-01

    Obesity is characterized as an accumulation of adipose tissue mass represented by chronic, low-grade inflammation. Obesity-derived inflammation involves chemokines as important regulators contributing to the pathophysiology of obesity-related diseases such as cardiovascular disease, diabetes and some cancers. The obesity-driven chemokine network is poorly understood. Here, we identified the profiles of chemokine signature between human preadipocytes and adipocytes, using PCR arrays and qRT-PCR. Both preadipocytes and adipocytes showed absent or low levels in chemokine receptors in spite of some changes. On the other hand, the chemokine levels of CCL2, CCL7-8, CCL11, CXCL1-3, CXCL6 and CXCL10-11 were dominantly expressed in preadipocytes compared to adipocytes. Interestingly, CXCL14 was the most dominant chemokine expressed in adipocytes compared to preadipocytes. Moreover, there is significantly higher protein level of CXCL14 in conditioned media from adipocytes. In addition, we analyzed the data of the chemokine signatures in adipocytes obtained from healthy lean and obese postmenopausal women based on Gene Expression Omnibus (GEO) dataset. Adipocytes from obese individuals had significantly higher levels in chemokine signature as follows: CCL2, CCL13, CCL18-19, CCL23, CCL26, CXCL1, CXCL3 and CXCL14, as compared to those from lean ones. Also, among the chemokine networks, CXCL14 appeared to be the highest levels in adipocytes from both lean and obese women. Taken together, these results identify CXCL14 as an important chemokine induced during adipogenesis, requiring further research elucidating its potential therapeutic benefits in obesity. PMID:27340388

  4. Adipocyte secreted factors enhance aggressiveness of prostate carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Ângela Moreira

    Full Text Available Obesity has been associated with increased incidence and risk of mortality of prostate cancer. One of the proposed mechanisms underlying this risk association is the change in adipokines expression that could promote the development and progression of the prostate tumor cells. The main goal of this study was to evaluate the effect of preadipocyte and adipocyte secretome in the proliferation, migration and invasion of androgen independent prostate carcinoma cells (RM1 and to assess cell proliferation in the presence of the adiposity signals leptin and insulin. RM1 cells were co-cultured in with preadipocytes, adipocytes or cultured in their respective conditioned medium. Cell proliferation was assessed by flow cytometry and XTT viability test. Cell migration was evaluated using a wound healing injury assay of RM1 cells cultured with conditioned media. Cellular invasion of RM1 cells co-cultured with adipocytes and preadipocytes was assessed using matrigel membranes. Preadipocyte conditioned medium was associated with a small increase in RM1 proliferation, while adipocytes conditioned media significantly increased RM1 cell proliferation (p<0.01. Adipocytes also significantly increased the RM1 cells proliferation in co-culture (p <0.01. Cell migration was higher in RM1 cells cultured with preadipocyte and adipocyte conditioned medium. RM1 cell invasion was significantly increased after co-culture with preadipocytes and adipocytes (p <0.05. Insulin also increased significantly the cell proliferation in contrast to leptin, which showed no effect. In conclusion, prostate carcinoma cells seem to be influenced by factors secreted by adipocytes that are able to increase their ability to proliferate, migrate and invade.

  5. Extra Fructose in the Growth Medium Fuels Lipogenesis of Adipocytes

    OpenAIRE

    Armin Robubi; Klaus R. Huber; Walter Krugluger

    2014-01-01

    Fructose in excessive amounts exerts negative effects on insulin sensitivity, blood pressure, and liver metabolism. These adverse outcomes were attributed to its disturbances of key metabolic pathways in the liver. Recently, possible consequences of high fructose levels directly on adipocytes in vivo have been considered. We have cultured adipocytes in growth media containing 1 g/L fructose additionally to glucose and monitored the cells fate. Cells developed lipid vesicles much earlier with ...

  6. Differential Chemokine Signature between Human Preadipocytes and Adipocytes.

    Science.gov (United States)

    Ignacio, Rosa Mistica C; Gibbs, Carla R; Lee, Eun-Sook; Son, Deok-Soo

    2016-06-01

    Obesity is characterized as an accumulation of adipose tissue mass represented by chronic, low-grade inflammation. Obesity-derived inflammation involves chemokines as important regulators contributing to the pathophysiology of obesity-related diseases such as cardiovascular disease, diabetes and some cancers. The obesity-driven chemokine network is poorly understood. Here, we identified the profiles of chemokine signature between human preadipocytes and adipocytes, using PCR arrays and qRT-PCR. Both preadipocytes and adipocytes showed absent or low levels in chemokine receptors in spite of some changes. On the other hand, the chemokine levels of CCL2, CCL7-8, CCL11, CXCL1-3, CXCL6 and CXCL10-11 were dominantly expressed in preadipocytes compared to adipocytes. Interestingly, CXCL14 was the most dominant chemokine expressed in adipocytes compared to preadipocytes. Moreover, there is significantly higher protein level of CXCL14 in conditioned media from adipocytes. In addition, we analyzed the data of the chemokine signatures in adipocytes obtained from healthy lean and obese postmenopausal women based on Gene Expression Omnibus (GEO) dataset. Adipocytes from obese individuals had significantly higher levels in chemokine signature as follows: CCL2, CCL13, CCL18-19, CCL23, CCL26, CXCL1, CXCL3 and CXCL14, as compared to those from lean ones. Also, among the chemokine networks, CXCL14 appeared to be the highest levels in adipocytes from both lean and obese women. Taken together, these results identify CXCL14 as an important chemokine induced during adipogenesis, requiring further research elucidating its potential therapeutic benefits in obesity. PMID:27340388

  7. Seeking the source of adipocytes in adult white adipose tissues

    OpenAIRE

    Lee, Yun-Hee; Granneman, James G.

    2012-01-01

    Adipocyte progenitors are thought to play a fundamental role in white adipose tissue (WAT) plasticity, which enables dynamic modulation of WAT metabolic and cellular characteristics in response to various stimuli. In general, two main strategies have been used to identify adipocyte progenitor cells: fluorescence-activated cell sorting (FACS)-based prospective analysis and lineage tracing. Although FACS-isolation is highly useful in defining multipotential stem cell populations for in vitro an...

  8. Cross-talk between sympathetic neurons and adipocytes in coculture

    OpenAIRE

    Turtzo, L. Christine; Marx, Ruth; Lane, M. Daniel

    2001-01-01

    White adipose tissue plays an integral role in energy metabolism and is governed by endocrine, autocrine, and neural signals. Neural control of adipose metabolism is mediated by sympathetic neurons that innervate the tissue. To investigate the effects of this innervation, an ex vivo system was developed in which 3T3-L1 adipocytes are cocultured with sympathetic neurons isolated from the superior cervical ganglia of newborn rats. In coculture, both adipocytes and neurons exhibit appropriate mo...

  9. Differentiation of preadipocytes and mature adipocytes requires PSMB8.

    Science.gov (United States)

    Arimochi, Hideki; Sasaki, Yuki; Kitamura, Akiko; Yasutomo, Koji

    2016-01-01

    The differentiation of adipocytes is tightly regulated by a variety of intrinsic molecules and also by extrinsic molecules produced by adjacent cells. Dysfunction of adipocyte differentiation causes lipodystrophy, which impairs glucose and lipid homeostasis. Although dysfunction of immunoproteasomes causes partial lipodystrophy, the detailed molecular mechanisms remain to be determined. Here, we demonstrate that Psmb8, a catalytic subunit for immunoproteasomes, directly regulates the differentiation of preadipocytes and additionally the differentiation of preadipocytes to mature adipocytes. Psmb8(-/-) mice exhibited slower weight gain than wild-type mice, and this was accompanied by reduced adipose tissue volume and smaller size of mature adipocytes compared with controls. Blockade of Psmb8 activity in 3T3-L1 cells disturbed the differentiation to mature adipocytes. Psmb8(-/-) mice had fewer preadipocyte precursors, fewer preadipocytes and a reduced ability to differentiate preadipocytes toward mature adipocytes. Our data demonstrate that Psmb8-mediated immunoproteasome activity is a direct regulator of the differentiation of preadipocytes and their ultimate maturation. PMID:27225296

  10. Regional differences in adipocyte lactate production from glucose

    International Nuclear Information System (INIS)

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

  11. MAP kinase phosphatase 2 regulates macrophage-adipocyte interaction.

    Directory of Open Access Journals (Sweden)

    Huipeng Jiao

    Full Text Available Inflammation is critical for the development of obesity-associated metabolic disorders. This study aims to investigate the role of mitogen-activated protein kinase phosphatase 2 (MKP-2 in inflammation during macrophage-adipocyte interaction.White adipose tissues (WAT from mice either on a high-fat diet (HFD or normal chow (NC were isolated to examine the expression of MKP-2. Murine macrophage cell line RAW264.7 stably expressing MKP-2 was used to study the regulation of MKP-2 in macrophages in response to saturated free fatty acid (FFA and its role in macrophage M1/M2 activation. Macrophage-adipocyte co-culture system was employed to investigate the role of MKP-2 in regulating inflammation during adipocyte-macrophage interaction. c-Jun N-terminal kinase (JNK- and p38-specific inhibitors were used to examine the mechanisms by which MKP-2 regulates macrophage activation and macrophage-adipocytes interaction.HFD changed the expression of MKP-2 in WAT, and MKP-2 was highly expressed in the stromal vascular cells (SVCs. MKP-2 inhibited the production of proinflammatory cytokines in response to FFA stimulation in macrophages. MKP-2 inhibited macrophage M1 activation through JNK and p38. In addition, overexpression of MKP-2 in macrophages suppressed inflammation during macrophage-adipocyte interaction.MKP-2 is a negative regulator of macrophage M1 activation through JNK and p38 and inhibits inflammation during macrophage-adipocyte interaction.

  12. Obesity-associated Inflammation Induces microRNA-155 Expression in Adipocytes and Adipose Tissue: Outcome on Adipocyte Function.

    Science.gov (United States)

    Karkeni, Esma; Astier, Julien; Tourniaire, Franck; El Abed, Mouna; Romier, Béatrice; Gouranton, Erwan; Wan, Lin; Borel, Patrick; Salles, Jérôme; Walrand, Stéphane; Ye, Jianping; Landrier, Jean-François

    2016-04-01

    miR-155 expression is induced in adipocytes and adipose tissue submitted to inflammatory conditions in obesity context in murine and human models and participate to a pro-inflammatory loop by targeting PPARg. PMID:26829440

  13. The CCAAT/enhancer binding protein and its role in adipocyte differentiation: evidence for direct involvement in terminal adipocyte development.

    OpenAIRE

    Samuelsson, L; Strömberg, K; Vikman, K; Bjursell, G; Enerbäck, S

    1991-01-01

    During the course of differentiation of preadipocytes into adipocytes, several differentiation-linked genes are activated synchronously with morphological changes. To follow this process we have used 3T3-F442A cells, known to undergo adipocyte conversion with high frequency. Accumulation of lipid droplets in the cytoplasm constitutes an easily visualized sign of the terminally differentiated phenotype. In this report we demonstrate that expression of the CCAAT/enhancer binding protein (C/EBP)...

  14. Adipocytes contribute to the growth and progression of multiple myeloma: Unraveling obesity related differences in adipocyte signaling.

    Science.gov (United States)

    Bullwinkle, Erica M; Parker, Melissa D; Bonan, Nicole F; Falkenberg, Lauren G; Davison, Steven P; DeCicco-Skinner, Kathleen L

    2016-09-28

    The prevalence of obesity over the last several decades in the United States has tripled among children and doubled among adults. Obesity increases the incidence and progression of multiple myeloma (MM), yet the molecular mechanisms by which adipocytes contribute to cancer development and patient prognosis have yet to be fully elucidated. Here, we obtained human adipose-derived stem cells (ASCs) from twenty-nine normal (BMI = 20-25 kg/m(2)), overweight (25-30 kg/m(2)), obese (30-35 kg/m(2)), or super obese (35-40 kg/m(2)) patients undergoing elective liposuction. Upon differentiation, adipocytes were co-cultured with RPMI-8226 and NCI-H929 MM cell lines. Adipocytes from overweight, obese and super obese patients displayed increased PPAR-gamma, cytochrome C, interleukin-6, and leptin protein levels, and decreased fatty acid synthase protein. 8226 MM cells proliferated faster and displayed increased pSTAT-3/STAT-3 signaling when cultured in adipocyte conditioned media. Further, adipocyte conditioned media from obese and super obese patients significantly increased MM cell adhesion, and conditioned media from overweight, obese and super obese patients enhanced tube formation and expression of matrix metalloproteinase-2. In summary, our data suggest that adipocytes in the MM microenvironment contribute to MM growth and progression and should be further evaluated as a possible therapeutic target. PMID:27317873

  15. 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.

  16. Lipolytic activity in adipocyte cell fractions.

    Science.gov (United States)

    Oschry, Y; Shapiro, B

    1980-05-28

    Adipocytes release only negligible amounts of free fatty acids unless stimulated, but reveal considerable lipolytic activity when homogenized. Epinephrine treatment of the cells caused only a 20-40% increase in the activity of infranatants of homogenates while raising the activity associated with the fat layer up to 10-fold. Full activity (i.e. that of intact-activated cells) could be revealed by epinephrine treatment of the homogenate as well as by sonication of the fat layer in buffer. The combination of both treatments did not yield higher activities. The fat cake contains the bulk of the potential activities which are only realized when dispersed in the aqueous phase by sonication, or upon hormone activation of the whole homogenate. Increase in activity could also be obtained by removal of most of the lipid from the fat layer by extraction with petroleum ether. Re-introduction of extracted lipid inhibited lipolysis. The active enzyme could be separated by flotation at 1.12 specific gravity. The data suggest that the lack of activity in the intact non-stimulated cell may be due to the lack of availability of the aqueous phase to the enzyme. PMID:7378439

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

    OpenAIRE

    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 ...

  19. 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.

  20. 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.

  1. Between brown and white: novel aspects of adipocyte differentiation.

    Science.gov (United States)

    Cinti, Saverio

    2011-03-01

    In all mammals including humans, most white and brown adipocytes are found together in visceral and subcutaneous depots (adipose organ) despite the well known difference in their function, respectively of storing energy and producing heat. A growing body of evidence suggests that the reason for such anatomical arrangement is their plasticity, which under appropriate stimulation allows direct conversion of one cell type into the other. In conditions of chronic cold exposure white-to-brown conversion meets the need for thermogenesis, whereas an obesogenic diet induces brown-to-white conversion to meet the need for storing energy. White-to-brown transdifferentiation is of medical interest, because the brown phenotype of the adipose organ is associated to obesity resistance, and drugs inducing this phenotype curb murine obesity and related disorders. Type 2 diabetes is the most common disorder associated to visceral obesity. Macrophages infiltrating the adipose organ are responsible for the low-grade chronic inflammation related to the removal of dead adipocytes, which leads to insulin resistance and T2 diabetes. Adipocyte death is closely related to their growth up to the critical death size. The critical death size of visceral adipocytes is smaller than that of subcutaneous adipocytes, likely accounting for the greater morbidity related to visceral fat. PMID:21254898

  2. Regulation of human subcutaneous adipocyte differentiation by EID1.

    Science.gov (United States)

    Vargas, Diana; Shimokawa, Noriaki; Kaneko, Ryosuke; Rosales, Wendy; Parra, Adriana; Castellanos, Ángela; Koibuchi, Noriyuki; Lizcano, Fernando

    2016-02-01

    Increasing thermogenesis in white adipose tissues can be used to treat individuals at high risk for obesity and cardiovascular disease. The objective of this study was to determine the function of EP300-interacting inhibitor of differentiation (EID1), an inhibitor of muscle differentiation, in the induction of beige adipocytes from adipose mesenchymal stem cells (ADMSCs). Subcutaneous adipose tissue was obtained from healthy women undergoing abdominoplasty. ADMSCs were isolated in vitro, grown, and transfected with EID1 or EID1 siRNA, and differentiation was induced after 48 h by administering rosiglitazone. The effects of EID1 expression under the control of the aP2 promoter (aP2-EID1) were also evaluated in mature adipocytes that were differentiated from ADMSCs. Transfection of EID1 into ADMSCs reduced triglyceride accumulation while increasing levels of thermogenic proteins, such as PGC1α, TFAM, and mitochondrial uncoupling protein 1 (UCP1), all of which are markers of energy expenditure and mitochondrial activity. Furthermore, increased expression of the beige phenotype markers CITED1 and CD137 was observed. Transfection of aP2-EID1 transfection induced the conversion of mature white adipocytes to beige adipocytes, as evidenced by increased expression of PGC1α, UCP1, TFAM, and CITED1. These results indicate that EID1 can modulate ADMSCs, inducing a brown/beige lineage. EID1 may also activate beiging in white adipocytes obtained from subcutaneous human adipose tissue. PMID:26643909

  3. Chromium propionate enhances adipogenic differentiation of bovine intramuscular adipocytes

    Directory of Open Access Journals (Sweden)

    Rebecca eTokach

    2015-09-01

    Full Text Available In vitro experiments were performed to determine the effects of increasing concentrations of chromium propionate on mRNA and protein abundance of different enzymes and receptors. Intramuscular and subcutaneous preadipocytes and bovine satellite cells were isolated from the longissimus muscle to determine the effect of treatment on glucose transporter type 4 (GLUT4 and peroxisome proliferator-activated receptor γ mRNA and GLUT4 protein abundance. Preadipocyte cultures were treated with differentiation media plus either sodium propionate or different concentrations of chromium propionate (CrPro for 96, 120, and 144 h before harvest. This study indicated adipogenesis of the bovine intramuscular adipocytes were more sensitive to the treatment of chromium propionate as compared to subcutaneous adipocytes. Enhancement of adenosine monophosphate-activated protein kinase and GLUT4 mRNA by CrPro treatment may enhance glucose uptake in intramuscular adipocytes. Chromium propionate decreased GLUT4 protein levels in muscle cell cultures suggesting those cells have increased efficiency of glucose uptake due to exposure to increased levels of CrPro. In contrast, each of the two adipogenic lines had opposing responses to the CrPro. It appeared that CrPro had the most stimulative effect of GLUT4 response in the intramuscular adipocytes as compared to subcutaneous adipocytes. These findings indicated opportunities to potentially augment marbling in beef cattle fed chromium propionate during the finishing phase.

  4. 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

    Adipocytes are central players in energy metabolism and the obesity epidemic, yet their protein composition remains largely unexplored. We investigated the adipocyte proteome by combining high accuracy, high sensitivity protein identification technology with subcellular fractionation of nuclei, m...

  5. PPARγ ligand production is tightly linked to clonal expansion during initiation of adipocyte differentiation

    DEFF Research Database (Denmark)

    Hallenborg, Philip; Petersen, Rasmus Koefoed; Feddersen, Søren;

    2014-01-01

    Adipocyte differentiation is orchestrated by the ligand-activated nuclear receptor PPAR. Endogenous ligands comprise oxidized derivatives of arachidonic acid and structurally similar PUFAs. Although expression of PPAR peaks in mature adipocytes, ligands are produced primarily at the onset...

  6. Rosiglitazone promotes development of a novel adipocyte population from bone marrow–derived circulating progenitor cells

    OpenAIRE

    Crossno, Joseph T.; Majka, Susan M.; Grazia, Todd; Gill, Ronald G.; Klemm, Dwight J.

    2006-01-01

    Obesity and weight gain are characterized by increased adipose tissue mass due to an increase in the size of individual adipocytes and the generation of new adipocytes. New adipocytes are believed to arise from resident adipose tissue preadipocytes and mesenchymal progenitor cells. However, it is possible that progenitor cells from other tissues, in particular BM, could also contribute to development of new adipocytes in adipose tissue. We tested this hypothesis by transplanting whole BM cell...

  7. Mitigation of isolation-associated adipocyte interleukin-6 secretion following rapid dissociation of adipose tissue

    OpenAIRE

    Airlia C S Thompson; Nuñez, Martha; Davidson, Ryan; Horm, Teresa; Schnittker, Karina; Hart, Madeline V.; Suarez, Allen M.; Tsao, Tsu-Shuen

    2012-01-01

    Primary adipocyte isolation by collagenase digestion is a widely used technique to study metabolic regulation and insulin action in adipocytes. However, induction of a proinflammatory response characterized by enhanced secretion of interleukin (IL)-6 has been tightly linked to the isolation process itself. To test the hypothesis that the shaking mechanical force exerted on adipocytes stimulates inflammation during isolation, rat primary adipocytes were prepared by collagenase digestion in orb...

  8. Postlipolytic insulin-dependent remodeling of micro lipid droplets in adipocytes

    OpenAIRE

    Ariotti, Nicholas; Murphy, Samantha; Hamilton, Nicholas A; Wu, Lizhen; Green, Kathryn; Nicole L Schieber; Li, Peng; Martin, Sally; Parton, Robert G.

    2012-01-01

    Despite the lipolysis–lipogenesis cycle being a fundamental process in adipocyte biology, very little is known about the morphological changes that occur during this process. The remodeling of lipid droplets to form micro lipid droplets (mLDs) is a striking feature of lipolysis in adipocytes, but once lipolysis ceases, the cell must regain its basal morphology. We characterized mLD formation in cultured adipocytes, and in primary adipocytes isolated from mouse epididymal fat pads, in response...

  9. 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.

  10. Peroxisome proliferator-activated receptor-alpha control of lipid and glucose metabolism in human white adipocytes.

    Science.gov (United States)

    Ribet, Carole; Montastier, Emilie; Valle, Carine; Bezaire, Véronic; Mazzucotelli, Anne; Mairal, Aline; Viguerie, Nathalie; Langin, Dominique

    2010-01-01

    This work aimed at characterizing the role of peroxisome proliferator-activated receptors (PPAR)alpha in human white adipocyte metabolism and at comparing PPAR alpha and PPAR gamma actions in these cells. Primary cultures of human fat cells were treated with the PPAR alpha agonist GW7647 or the PPAR gamma agonist rosiglitazone. Changes in gene expression were determined using DNA microarrays and quantitative RT-PCR. Western blot and metabolic studies were performed to identify the biological effects elicited by PPAR agonist treatments. GW7647 induced an up-regulation of beta-oxidation gene expression and increased palmitate oxidation. Unexpectedly, glycolysis was strongly reduced at transcriptional and functional levels by GW7647 leading to a decrease in pyruvate and lactate production. Glucose oxidation was decreased. Triglyceride esterification and de novo lipogenesis were inhibited by the PPAR alpha agonist. GW7647-induced alterations were abolished by a treatment with a PPAR alpha antagonist. Small interfering RNA-mediated extinction of PPAR alpha gene expression in hMADS adipocytes attenuated GW7647 induction of palmitate oxidation. Rosiglitazone had no major impact on glycolysis and beta-oxidation. Altogether these results show that PPAR alpha can selectively up-regulate beta-oxidation and decrease glucose utilization in human white adipocytes. PMID:19887568

  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. Perilipin-mediated lipid droplet formation in adipocytes promotes sterol regulatory element-binding protein-1 processing and triacylglyceride accumulation.

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    Yu Takahashi

    Full Text Available Sterol regulatory element-binding protein-1 (SREBP-1 has been thought to be a critical factor that assists adipogenesis. During adipogenesis SREBP-1 stimulates lipogenic gene expression, and peroxisome proliferator-activated receptor γ (PPARγ enhances perilipin (plin gene expression, resulting in generating lipid droplets (LDs to store triacylglycerol (TAG in adipocytes. Plin coats adipocyte LDs and protects them from lipolysis. Here we show in white adipose tissue (WAT of plin-/- mice that nuclear active SREBP-1 and its target gene expression, but not nuclear SREBP-2, significantly decreased on attenuated LD formation. When plin-/- mouse embryonic fibroblasts (MEFs differentiated into adipocytes, attenuated LDs were formed and nuclear SREBP-1 decreased, but enforced plin expression restored them to their original state. Since LDs are largely derived from the endoplasmic reticulum (ER, alterations in the ER cholesterol content were investigated during adipogenesis of 3T3-L1 cells. The ER cholesterol greatly reduced in differentiated adipocytes. The ER cholesterol level in plin-/- WAT was significantly higher than that of wild-type mice, suggesting that increased LD formation caused a change in ER environment along with a decrease in cholesterol. When GFP-SREBP-1 fusion proteins were exogenously expressed in 3T3-L1 cells, a mutant protein lacking the S1P cleavage site was poorly processed during adipogenesis, providing evidence of the increased canonical pathway for SREBP processing in which SREBP-1 is activated by two cleavage enzymes in the Golgi. Therefore, LD biogenesis may create the ER microenvironment favorable for SREBP-1 activation. We describe the novel interplay between LD formation and SREBP-1 activation through a positive feedback loop.

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

    International Nuclear Information System (INIS)

    Highlights: → PPARα activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. → PPARα activation also increased insulin-dependent glucose uptake in human adipocytes. → PPARα activation did not affect lipid accumulation in human adipocytes. → PPARα activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-α (PPARα) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPARα in adipocytes have been unclarified. We examined the functions of PPARα using human multipotent adipose tissue-derived stem cells as a human adipocyte model. Activation of PPARα by GW7647, a potent PPARα agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPARγ, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPARα activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPARγ is activated. On the other hand, PPARα activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPARα-dependent manner. Moreover, PPARα activation increased the production of CO2 and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPARα stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPARα agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected effects of PPARα activation are very valuable for managing diabetic conditions accompanied by obesity, because PPAR

  14. α-Naphthoflavone Increases Lipid Accumulation in Mature Adipocytes and Enhances Adipocyte-Stimulated Endothelial Tube Formation

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    Mei-Lin Wang

    2015-04-01

    Full Text Available The aryl hydrocarbon receptor (AhR is a ligand-activated factor that regulates biological effects associated with obesity. The AhR agonists, such as environmental contaminants 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD and β-naphthoflavone (BNF, inhibit preadipocyte differentiation and interfere with the functions of adipose tissue, whereas the antagonist may have opposite or protective effects in obesity. This study investigated the effects of α-naphthoflavone (α-NF, an AhR antagonist, on adipogenesis- and angiogenesis-associated factors in mature adipocytes and on cross-talk of mature adipocytes with endothelial cells (ECs. Besides, the roles of the AhR on lipid accumulation and on secretion of vascular endothelial growth factor were also determined by introducing siRNA of AhR. Differentiated 3T3-L1 cells were treated with α-naphthoflavone (α-NF (1–5 μM for 16 h. Lipid accumulation and the expressions of AhR-associated factors in the cells were determined. The interaction between adipocytes and ECs was investigated by cultivating ECs with conditioned medium (CM from α-NF-treated mature adipocytes, followed by the determination of endothelial tube formation. The results showed that α-NF significantly increased triglyceride (TG accumulation in mature adipocytes, which was associated with increased expression of hormone-sensitive lipase (HSL, estrogen receptor (ER, as well as decreased expression of AhR, AhR nuclear translocator (ARNT, cytochrome P4501B1 (CYP1B1, and nuclear factor erythroid-2-related factor (NRF-2 proteins. In addition, CM stimulated formation of tube-like structures in ECs, and α-NF further enhanced such stimulation in association with modulated the secretions of various angiogenic mediators by mature adipocytes. Similarly, increased TG accumulation and vascular endothelial growth factor (VEGF secretion were observed in AhR-knockout cells. In conclusion, α-NF increased TG accumulation in mature adipocytes and

  15. RNase L controls terminal adipocyte differentiation, lipids storage and insulin sensitivity via CHOP10 mRNA regulation

    DEFF Research Database (Denmark)

    Fabre, Odile Martine Julie; Salehzada, T; Lambert, K;

    2012-01-01

    Adipose tissue structure is altered during obesity, leading to deregulation of whole-body metabolism. Its function depends on its structure, in particular adipocytes number and differentiation stage. To better understand the mechanisms regulating adipogenesis, we have investigated the role...... an expanded adipose tissue, which, however, is unable to correctly store lipids, illustrated by ectopic lipids storage in the liver and in the kidney. These findings highlight RNase L as an essential regulator of adipogenesis via the regulation of CHOP10 mRNA....

  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. 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.

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

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    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.

  19. 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...

  20. Adipocyte size fluctuation, mechano-active lipid droplets and caveolae

    OpenAIRE

    Le Lay, Soazig; Briand, Nolwenn; Dugail, Isabelle

    2014-01-01

    Recent data indicate that cell size fluctuation, a key property in adipocyte pathophysiology primarily dependent on lipid storage, is linked to a novel function of lipid droplet organelles acting as mechano-active organelles to regulate cell membrane remodeling and caveolae dynamics.

  1. Radiation inactivation target size of rat adipocyte glucose transporter

    International Nuclear Information System (INIS)

    In situ assembly states of rat adipocyte glucose transport protein in plasma membrane (PM) and in microsomal pool (MM) were assessed by measuring target size (TS) of D glucose-sensitive, cytochalasin B binding activity. High energy radiation inactivated the binding in both PM and MM by reducing the total capacity of the binding (B/sub T/) without affecting the dissociation constant (K/sub D/). The reduction in B/sub T/ as a function of radiation dose was analyzed based on classical target theory, from which TS was calculated. TS in the PM of insulin-treated adipocytes was 58 KDa. TS in the MM of noninsulin-treated and insulin-treated adipocytes were 112 and 109 KDa, respectively. With MM, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses showing a shoulder in the semilog plots, which may be due to an interaction with a radiation sensitive inhibitor. With these results, they propose the following model: Adipocyte glucose transporter, while exists as a monomer (T) in PM, occurs in MM either as a homodimer (T2) or as a heterodimer (TX) with a protein X of a similar size. These dimers (T2 or TX) in MM, furthermore, may form a multi-molecular assembly with another, large (300-400 KDa) protein Y, and insulin increases this assembly formation. These putative, transporter-associated proteins X and Y may play an important role in control of transporter distribution between PM and MM, particularly in response to insulin

  2. Stressed Liver and Muscle Call on Adipocytes with FGF21

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    Yongde eLuo

    2013-12-01

    Full Text Available Fibroblast growth factor 21 (FGF21 is an emerging regulator of local and systemic metabolic homeostasis. Treatment with pharmacological levels of FGF21 alleviates obesity and associated metabolic diseases including diabetes. However, beyond antiobesogenic effects, the normal roles and underlying mechanisms of FGF21 as an endocrine hormone remain unclear. A recent wave of studies has revealed that FGF21 is a stress-induced endocrine factor in liver, muscle and other tissues that targets adipose tissue and adipocytes through FGFR1-betaKlotho (KLB complex. Adipose tissues and adipocytes within diverse tissues respond with metabolites and adipokine signals that affect functions of body tissues systemically and cells within local microenvironment adjacent to adipocytes. Normally this is to prevent impaired tissue-specific function and damage to diverse tissues secreting FGF21 in response to chronic stress. Therefore, diverse stressed tissues and the adipose tissue and adipocytes constitute a beneficial endocrine and paracrine communication network through FGF21. Here we attempt to unify these developments with beneficial pharmacological effects of FGF21 on obesity in respect to inter-organ stress communication and mechanisms.

  3. 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...

  4. CD36 is important for adipocyte recruitment and affects lipolysis

    NARCIS (Netherlands)

    Vroegrijk, I.O.; Klinken, J.B. van; Diepen, J.A. van; Berg, S.A. van den; Febbraio, M.; Steinbusch, L.K.; Glatz, J.F.C.; Havekes, L.M.; Voshol, P.J.; Rensen, P.C.; Dijk, K.W. van; Harmelen, V. van

    2013-01-01

    OBJECTIVE: The scavenger receptor CD36 facilitates the cellular uptake of long-chain fatty acids. As CD36-deficiency attenuates the development of high fat diet (HFD)-induced obesity, the role of CD36-deficiency in preadipocyte recruitment and adipocyte function was set out to characterize. DESIGN A

  5. CD36 is important for adipocyte recruitment and affects lipolysis

    NARCIS (Netherlands)

    Vroegrijk, I.O.; Klinken, J.B. van; Diepen, J.A. van; Berg, S.A. van den; Febbraio, M.; Steinbusch, L.K.; Glatz, J.F.; Havekes, L.M.; Voshol, P.J.; Rensen, P.C.; Dijk, K.W. van; Harmelen, V. van

    2013-01-01

    Objective: The scavenger receptor CD36 facilitates the cellular uptake of long-chain fatty acids. As CD36-deficiency attenuates the development of high fat diet (HFD)-induced obesity, the role of CD36-deficiency in preadipocyte recruitment and adipocyte function was set out to characterize. Design a

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

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    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.

  7. Effects of homocysteine on adipocyte differentiation and CD36 gene expression in 3T3-L1 adipocytes.

    Science.gov (United States)

    Mentese, Ahmet; Alver, Ahmet; Sumer, Aysegul; Demir, Selim

    2016-03-01

    The aim of this study was to investigate the effects of homocysteine (Hcy), a risk factor for cardiovascular diseases, hypertension, stroke and obesity, on expression of CD36 that regulates uptake of oxidized low-density lipoprotein (Ox-LDL) by adipocytes and differentiation of 3T3-L1 cells to adipocytes. Cell viability was determined using MTT assay, and density of triglycerides were measured with Oil Red O staining. The expression levels of CD36 were analyzed using SYBR green assay by quantitative RT-PCR. Our results showed that the addition of Hcy inhibited differentiation of 3T3-L1 preadipocytes in a dose-dependent manner without a significant cell toxicity (p  0.05) compared to differentiated adipocytes. Hcy reduced adipocyte differentiation, but had no effect on the expression level of CD36 in vitro conditions. The effect of Hcy on uptake and clearance of Ox-LDL by adipose tissue now needs to be investigated in vivo. PMID:26691520

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

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    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

  9. 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.

  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. REGULATION OF RETINOL BINDING PROTEIN 4 EXPRESSION AND ITS RELATION TO ADIPOGENESIS IN BOVINE ADIPOCYTES

    Directory of Open Access Journals (Sweden)

    Abd Eldaim Mabrouk Attia

    2012-01-01

    Full Text Available Adipogenesis is of great importance in beef cattle. Recent findings indicate that glucose, a substrate for fatty acid biosynthesis and retinoic acid enhance adipogenesis in bovine intramuscular adipocytes. However, other recent findings indicate that Retinol-Binding Protein 4 (RBP4 interferes with glucose uptake and utilization by rodents’ adipocytes. In this study we examined the regulation of RBP4 expression and its relation to adipogenesis in bovine adipocytes. Stromal vascular cells were prepared by collagenase digestion from subcutaneous and intramuscular adipose tissues of Japanese black steers. RT-PCR revealed that RBP4 mRNA was expressed in bovine adipose tissue. Northern and Western Blot analysis showed that RBP4 was highly expressed and secreted from bovine preadipocytes. However, RBP4 expression and secretion were significantly reduced by induction of the adipogenic differentiation of preadipocytes into mature adipocytes. Glucose and retinoic acid have a suppressive effect on RBP4 expression and secretion from intramuscular adipocytes. Retinoic acid significantly decreased RBP4 expression in Japanese black steer subcutaneous adipocytes. Retinoic acid itself had no effect on lipid accumulation in subcutaneous adipocytes however, retinoic acid enhanced lipid accumulation in these adipocytes after addition of acetate, a substrate for fatty acid biosynthesis in subcutaneous adipocytes. This study indicated a negative correlation between adipogenesis and RBP4 expression in bovine adipocytes and suggests possible inhibitory effect of RBP4 on adipogenesis.

  12. 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. PMID:27386153

  13. 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.

  14. 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...

  15. 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.

  16. 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.

  17. Binding and degradation of [125I]human growth hormone in rat adipocytes

    International Nuclear Information System (INIS)

    Iodinated human growth hormone [( 125I]hGH) binds to both specific and nonspecific sites on the surface of adipocytes isolated from the epididymal fat of normal rats. When adipocytes were incubated at 37 C with 1 nM [125I]hGH, specific binding increased for 30-60 min and thereafter remained approximately constant as long as the hormone was present in the medium. About 90% of the 125I released was soluble in 5% trichloroacetic acid and was in the form of iodotyrosine. The rate of 125I release from specific binding sites decreased by a factor of 4 when the temperature was lowered from 37 to 17 C. Replacement of some of the sodium chloride in the buffer with 25 mM ammonium chloride had little or no effect on the amount on 125I that bound to cells when [125I]hGH was present in the medium, but completely blocked the release of 125I from cells transferred to hormone-free medium. Ammonium chloride also significantly reduced both the release of 125I from nonspecific binding sites and the amount of 125I recovered in trichloroacetic acid-soluble form. Cloroquine, leupeptin, or colchicine nearly doubled the specific binding of [125I]hGH after 180 min and markedly slowed the release of 125I when cells were transferred to hormone-free medium. All of these agents also significantly reduced the rate of release of 125I from nonspecific binding sites. Incubation of adipose tissue from hypophysectomized rats with ammonium chloride, leupeptin, or colchicine failed to alter the ability of GH to increase glucose oxidation, induce refractoriness, or promote lipolysis in the presence of theophylline

  18. Radiation inactivation target size of rat adipocyte glucose transporter

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-05-01

    In situ assembly states of rat adipocyte glucose transport protein in plasma membrane (PM) and in microsomal pool (MM) were assessed by measuring target size (TS) of D glucose-sensitive, cytochalasin B binding activity. High energy radiation inactivated the binding in both PM and MM by reducing the total capacity of the binding (B/sub T/) without affecting the dissociation constant (K/sub D/). The reduction in B/sub T/ as a function of radiation dose was analyzed based on classical target theory, from which TS was calculated. TS in the PM of insulin-treated adipocytes was 58 KDa. TS in the MM of noninsulin-treated and insulin-treated adipocytes were 112 and 109 KDa, respectively. With MM, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses showing a shoulder in the semilog plots, which may be due to an interaction with a radiation sensitive inhibitor. With these results, they propose the following model: Adipocyte glucose transporter, while exists as a monomer (T) in PM, occurs in MM either as a homodimer (T/sub 2/) or as a heterodimer (TX) with a protein X of a similar size. These dimers (T/sub 2/ or TX) in MM, furthermore, may form a multi-molecular assembly with another, large (300-400 KDa) protein Y, and insulin increases this assembly formation. These putative, transporter-associated proteins X and Y may play an important role in control of transporter distribution between PM and MM, particularly in response to insulin.

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

    OpenAIRE

    Nakamura Kumi; Kondo Yoshie; Udono Miyako; Tanaka Yasutake; Baba Sanae; Kawamura Sayaka; Katakura Yoshinori; Tong Li-Tao; Imaizumi Katsumi; Sato Masao

    2010-01-01

    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 subcutaneo...

  20. Silibinin Regulates Lipid Metabolism and Differentiation in Functional Human Adipocytes

    OpenAIRE

    Barbagallo, Ignazio; Vanella, Luca; Cambria, Maria T.; Tibullo, Daniele; Godos, Justyna; Guarnaccia, Laura; Zappalà, Agata; Galvano, Fabio; Li Volti, Giovanni

    2016-01-01

    Silibinin, a natural plant flavonolignan 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 differentiati...

  1. The Effect of Crataegi Fructus Pharmacopuncture on Adipocyte Metabolism

    Directory of Open Access Journals (Sweden)

    Seung Hwan, Won

    2008-06-01

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

  2. The effect of Spirodelae Herba Pharmacopuncture on Adipocyte Metabolism

    Directory of Open Access Journals (Sweden)

    Sung Eon, Cho

    2008-03-01

    Full Text Available Objectives : The purpose of this study is to investigate the effects of Spirodelae Herba pharmacopuncture(SHP on the adipogenesis in 3T3 cells, lipolysis in rat epididymal adipocytes and histological changes in porcine adipose tissue. Methods : Inhibition of preadipocyte differentiation and/or stimulation of lipolysis play important roles in reducing obesity. 3T3 preadipocytes were differentiated with adipogenic reagents by incubating for 3 days in the absence or presence of SHP ranging from 0.01 to 1.0㎎/㎖. The effect of SHP on adipogenesis was examined by measuring glycerol-3-phosphate ehydrogenase(GPDH activity and by Oil Red O staining. Mature adipocytes from rat epididymal fat pad was incubated with SHP ranging from 0.01 to 1.0㎎/㎖ for 3 days. The effect of SHP on lipolysis was examined by measuring free glycerol released. Fat tissue from porcine skin was injected with SHP ranging from 0.1 to 10.0㎎/㎖ to examine the effect of SHP onhistological changes under light microscopy. Results : Following results were obtained from the preadipocyte proliferation and lipolysis adipocyte and histologic investigation of fat tissue 1. SHP showed the effect of decreased preadipocyte proliferation on the high dosage(1㎎/㎖. 2. SHP showed the effect of decreased the activity of glycerol-3-phosphate dehydrogenase (GPDH on the high dosage(1㎎/㎖. 3. Investigated the changes in lipolysis of differentiated adipocyte after treated SHP, we knew that these pharmacopunct -ure showed increasing the effect of lipolysis in all concentration significantly. 4. Investigated the histological changes in porcine fat tissue after treated SHP, we knew that these pharmacopuncture showed significant activity to the lysis of extensive cell membranes on high dosage(10.0㎎/㎖. Conclusions : These results suggest that SHP efficiently induces diminishing proliferation of preadipocyte and lipolysis in adipose tissue.

  3. Quantifying Size and Number of Adipocytes in Adipose Tissue

    OpenAIRE

    Parlee, Sebastian D.; Lentz, Stephen I.; Mori, Hiroyuki; MacDougald, Ormond A.

    2014-01-01

    White adipose tissue (WAT) is a dynamic and modifiable tissue that develops late during gestation in humans and through early postnatal development in rodents. WAT is unique in that it can account for as little as 3% of total body weight in elite athletes or as much as 70% in the morbidly obese. With the development of obesity, WAT undergoes a process of tissue remodeling in which adipocytes increase in both number (hyperplasia) and size (hypertrophy). Metabolic derangements associated with o...

  4. Systemic Fate of the Adipocyte-Derived Factor Adiponectin

    OpenAIRE

    Halberg, Nils; Schraw, Todd D.; Wang, Zhao V.; Kim, Ja-Young; Yi, James; Hamilton, Mark P.; Luby-Phelps, Kate; Scherer, Philipp E.

    2009-01-01

    OBJECTIVE The adipocyte-derived secretory protein adiponectin has been widely studied and shown to have potent insulin-sensitizing, antiapoptotic, and anti-inflammatory properties. While its biosynthesis is well understood, its fate, once in circulation, is less well established. RESEARCH DESIGN AND METHODS Here, we examine the half-life of adiponectin in circulation by tracking fluorescently labeled recombinant adiponectin in the circulation, following it to its final destination in the hepa...

  5. 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.

  6. CD36 is important for adipocyte recruitment and affects lipolysis

    OpenAIRE

    Vroegrijk, I.O.; Klinken, J.B. van; Diepen, J.A. van; Berg, S.A. van den; Febbraio, M.; Steinbusch, L.K.; Glatz, J.F.; Havekes, L M; Voshol, P.J.; Rensen, P. C.; Dijk, K.W. van; Harmelen, V. van

    2013-01-01

    Objective: The scavenger receptor CD36 facilitates the cellular uptake of long-chain fatty acids. As CD36-deficiency attenuates the development of high fat diet (HFD)-induced obesity, the role of CD36-deficiency in preadipocyte recruitment and adipocyte function was set out to characterize. Design and methods: Fat cell size and number were determined in gonadal, visceral, and subcutaneous adipose tissue of CD36(-/-) and WT mice after 6 weeks on HFD. Basal lipolysis and insulin-inhibited lipol...

  7. Novel aspects of metabolic regulation and inflammation in human adipocytes

    OpenAIRE

    Pettersson, Annie

    2015-01-01

    The significance of adipose tissue and obesity has been recognized in numerous pathologies. However, the mechanisms behind this connection are not yet completely understood. The aim of this thesis was to investigate the roles of Liver X Receptor (LXR), V-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB) and Salt-inducible kinases (SIKs) in primary human adipocytes with focus on metabolic regulation and inflammation. Our overall hypothesis was that these factors may influence metab...

  8. Physiological determinants and impacts of the adipocyte phenotype

    OpenAIRE

    Tchernof, A; Richard, D.

    2015-01-01

    The properties of adipose tissues accumulating in various compartments and ectopic sites around the body represent critical determinants of the relationship between obesity and metabolic disease. The increasingly recognized plasticity of the adipose cell phenotype led to many articles on the cellular characteristics and origins on brown, white and also of ‘beige' or ‘brite' adipocytes in recent years. This overview is a summary of manuscripts that were prepared by speakers at the 16th Interna...

  9. 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.

  10. 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.

  11. 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

  12. Transcriptional regulation of adipocyte hormone-sensitive lipase by glucose.

    Science.gov (United States)

    Smih, Fatima; Rouet, Philippe; Lucas, Stéphanie; Mairal, Aline; Sengenes, Coralie; Lafontan, Max; Vaulont, Sophie; Casado, Marta; Langin, Dominique

    2002-02-01

    Hormone-sensitive lipase (HSL) catalyzes the rate-limiting step in the mobilization of fatty acids from adipose tissue, thus determining the supply of energy substrates in the body. HSL mRNA was positively regulated by glucose in human adipocytes. Pools of stably transfected 3T3-F442A adipocytes were generated with human adipocyte HSL promoter fragments from -2,400/+38 to -31/+38 bp linked to the luciferase gene. A glucose-responsive region was mapped within the proximal promoter (-137 bp). Electromobility shift assays showed that upstream stimulatory factor (USF)-1 and USF2 and Sp1 and Sp3 bound to a consensus E-box and two GC-boxes in the -137-bp region. Cotransfection of the -137/+38 construct with USF1 and USF2 expression vectors produced enhanced luciferase activity. Moreover, HSL mRNA levels were decreased in USF1- and USF2-deficient mice. Site-directed mutagenesis of the HSL promoter showed that the GC-boxes, although contributing to basal promoter activity, were dispensable for glucose responsiveness. Mutation of the E-box led to decreased promoter activity and suppression of the glucose response. Analogs and metabolites were used to determine the signal metabolite of the glucose response. The signal is generated downstream of glucose-6-phosphate in the glycolytic pathway before the triose phosphate step. PMID:11812735

  13. Adipocyte lipases and defect of lipolysis in human obesity.

    Science.gov (United States)

    Langin, Dominique; Dicker, Andrea; Tavernier, Geneviève; Hoffstedt, Johan; Mairal, Aline; Rydén, Mikael; Arner, Erik; Sicard, Audrey; Jenkins, Christopher M; Viguerie, Nathalie; van Harmelen, Vanessa; Gross, Richard W; Holm, Cecilia; Arner, Peter

    2005-11-01

    The mobilization of fat stored in adipose tissue is mediated by hormone-sensitive lipase (HSL) and the recently characterized adipose triglyceride lipase (ATGL), yet their relative importance in lipolysis is unknown. We show that a novel potent inhibitor of HSL does not inhibit other lipases. The compound counteracted catecholamine-stimulated lipolysis in mouse adipocytes and had no effect on residual triglyceride hydrolysis and lipolysis in HSL-null mice. In human adipocytes, catecholamine- and natriuretic peptide-induced lipolysis were completely blunted by the HSL inhibitor. When fat cells were not stimulated, glycerol but not fatty acid release was inhibited. HSL and ATGL mRNA levels increased concomitantly during adipocyte differentiation. Abundance of the two transcripts in human adipose tissue was highly correlated in habitual dietary conditions and during a hypocaloric diet, suggesting common regulatory mechanisms for the two genes. Comparison of obese and nonobese subjects showed that obesity was associated with a decrease in catecholamine-induced lipolysis and HSL expression in mature fat cells and in differentiated preadipocytes. In conclusion, HSL is the major lipase for catecholamine- and natriuretic peptide-stimulated lipolysis, whereas ATGL mediates the hydrolysis of triglycerides during basal lipolysis. Decreased catecholamine-induced lipolysis and low HSL expression constitute a possibly primary defect in obesity. PMID:16249444

  14. Human Mature Adipocytes Express Albumin and This Expression Is Not Regulated by Inflammation

    OpenAIRE

    Eleonora Riccio; Giovanni Pertosa; Simona Simone; Giuseppe Grandaliano; Maurizio Sodo; Andrea Pota; Alfredo Procino; Bruna Guida; Maria Luisa Sirico; Bruno Memoli

    2012-01-01

    Aims. Our group investigated albumin gene expression in human adipocytes, its regulation by inflammation and the possible contribution of adipose tissue to albumin circulating levels. Methods. Both inflamed and healthy subjects provided adipose tissue samples. RT-PCR, Real-Time PCR, and Western Blot analysis on homogenates of adipocytes and pre-adipocytes were performed. In sixty-three healthy subjects and fifty-four micro-inflamed end stage renal disease (ESRD) patients circulating levels of...

  15. ADIPOSE TRIGLYCERIDE LIPASE REGULATES BASAL LIPOLYSIS AND LIPID DROPLET SIZE IN ADIPOCYTES

    OpenAIRE

    Miyoshi, Hideaki; Perfield, James W.; Obin, Martin S.; Greenberg, Andrew S.

    2008-01-01

    In adipocytes, lipid droplet (LD) size reflects a balance of triglyceride synthesis (lipogenesis) and hydrolysis (lipolysis). Perilipin A (Peri A), is the most abundant phosphoprotein on the surface of adipocyte LDs and has a crucial role in lipid storage and lipolysis. Adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) are the major rate-determining enzymes for lipolysis in adipocytes. Each of these proteins (Peri A, ATGL and HSL) have been demonstrated to regulate lipid s...

  16. Adipocyte-specific deficiency of angiotensinogen decreases plasma angiotensinogen concentration and systolic blood pressure in mice

    OpenAIRE

    Yiannikouris, Frederique; Karounos, Michael; Charnigo, Richard; English, Victoria L.; Rateri, Debra L.; Daugherty, Alan; Cassis, Lisa A.

    2011-01-01

    Previous studies demonstrated that overexpression of angiotensinogen (AGT) in adipose tissue increased blood pressure. However, the contribution of endogenous AGT in adipocytes to the systemic renin-angiotensin system (RAS) and blood pressure control is undefined. To define a role of adipocyte-derived AGT, mice with loxP sites flanking exon 2 of the AGT gene (Agtfl/fl) were bred to transgenic mice expressing Cre recombinase under the control of an adipocyte fatty acid-binding protein 4 promot...

  17. Single-cell analysis of insulin-regulated fatty acid uptake in adipocytes

    OpenAIRE

    Varlamov, Oleg; Somwar, Romel; Cornea, Anda; Kievit, Paul; Grove, Kevin L.; Roberts, Charles T.

    2010-01-01

    Increased body fat correlates with the enlargement of average fat cell size and reduced adipose tissue insulin sensitivity. It is currently unclear whether adipocytes, as they accumulate more triglycerides and grow in size, gradually become less insulin sensitive or whether obesity-related factors independently cause both the enlargement of adipocyte size and reduced adipose tissue insulin sensitivity. In the first instance, large and small adipocytes in the same tissue would exhibit differen...

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

    OpenAIRE

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

    1985-01-01

    To study the regulation of adipose tissue lipoprotein lipase (LPL) in human adipocytes, omental adipose tissue was obtained from healthy subjects and digested in collagenase. The isolated adipocytes thus obtained were suspended in Medium 199 and cultured at 37 degrees C. Cell viability was demonstrated in adipocytes cultured for up to 72 h by constancy of cell number, cell size, trypan-blue exclusion, and specific 125I-insulin binding. In addition, chloroquine induced an increase in cell-asso...

  19. Differential adipogenic and inflammatory properties of small adipocytes in Zucker Obese and Lean rats

    OpenAIRE

    Liu, Alice; Sonmez, Alper; Yee, Gail; Bazuine, Merlijn; Arroyo, Matilde; Sherman, Arthur; McLaughlin, Tracey; Reaven, Gerald; Cushman, Samuel; Tsao, Philip

    2010-01-01

    We recently reported that a preponderance of small adipose cells, decreased expression of cell differentiation markers, and enhanced inflammatory activity in human subcutaneous whole adipose tissue were associated with insulin resistance. To test the hypothesis that small adipocytes exhibited these differential properties, we characterized small adipocytes from epididymal adipose tissue of Zucker Obese (ZO) and Lean (ZL) rats. Rat epididymal fat pads were removed and adipocytes isolated by co...

  20. Pre-adipocyte determination either by insulin or by 5-azacytidine.

    OpenAIRE

    Sager, R; Kovac, P.

    1982-01-01

    CHEF/18 is a diploid Chinese hamster cell line of embryonic origin, which is fibroblastic in structure, but behaves like a mesenchymal stem cell line in its ability to differentiate into adipocytes, myoblasts, and chondrocytes. With these cells, adipocyte formation has been divided experimentally into two stages: (i) determination of pre-adipocytes, which have lost the ability to form other cell types while retaining their fibroblast structure; and (ii) commitment or terminal differentiation,...

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

    DEFF Research Database (Denmark)

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

    1993-01-01

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

  2. 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.

  3. Early B-cell Factor 1 Regulates Adipocyte Morphology and Lipolysis in White Adipose Tissue

    OpenAIRE

    Gao, Hui; Mejhert, Niklas; Fretz, Jackie A.; Arner, Erik; Lorente-Cebrián, Silvia; Ehrlund, Anna; Dahlman-Wright, Karin; Gong, Xiaowei; Strömblad, Staffan; Douagi, Iyadh; Laurencikiene, Jurga; Dahlman, Ingrid; Daub, Carsten O.; Rydén, Mikael; Horowitz, Mark C.

    2014-01-01

    White adipose tissue (WAT) morphology characterized by hypertrophy (i.e. fewer but larger adipocytes) associates with increased adipose inflammation, lipolysis, insulin resistance and risk of diabetes. However, the causal relationships and the mechanisms controlling WAT morphology are unclear. Herein, we identified EBF1 as an adipocyte-expressed transcription factor with decreased expression/activity in WAT hypertrophy. In human adipocytes, the regulatory targets of EBF1 were enriched for gen...

  4. Anti-adipogenic effect of mulberry leaf ethanol extract in 3T3-L1 adipocytes

    OpenAIRE

    Yang, Soo Jin; Park, Na-Young; LIM, YUNSOOK

    2014-01-01

    BACKGROUND/OBJECTIVES Adipogenesis is part of the cell differentiation process in which undifferentiated fibroblasts (pre-adipocytes) become mature adipocytes with the accumulation of lipid droplets and subsequent cell morphological changes. Several transcription factors and food components have been suggested to be involved in adipogenesis. The aim of this study was to determine whether mulberry leaf ethanol extract (MLEE) affects adipogenesis in 3T3-L1 adipocytes. MATERIALS/METHODS The 3T3-...

  5. Human coronary artery perivascular adipocytes overexpress genes responsible for regulating vascular morphology, inflammation, and hemostasis

    OpenAIRE

    Chatterjee, Tapan K.; Aronow, Bruce J; Tong, Wilson S.; Manka, David; Tang, Yaoliang; Bogdanov, Vladimir Y.; Unruh, Dusten; Blomkalns, Andra L.; Piegore, Mark G.; Weintraub, Daniel S.; Rudich, Steven M.; Kuhel, David G; Hui, David Y.; Weintraub, Neal L.

    2013-01-01

    Inflammatory cross talk between perivascular adipose tissue and the blood vessel wall has been proposed to contribute to the pathogenesis of atherosclerosis. We previously reported that human perivascular (PV) adipocytes exhibit a proinflammatory phenotype and less adipogenic differentiation than do subcutaneous (SQ) adipocytes. To gain a global view of the genomic basis of biologic differences between PV and SQ adipocytes, we performed genome-wide expression analyses to identify differential...

  6. 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

  7. 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.

  8. Biology of Beige Adipocyte and Possible Therapy for Type 2 Diabetes and Obesity.

    Science.gov (United States)

    Lizcano, Fernando; Vargas, Diana

    2016-01-01

    All mammals own two main forms of fat. The classical white adipose tissue builds up energy in the form of triglycerides and is useful for preventing fatigue during periods of low caloric intake and the brown adipose tissue instead of inducing fat accumulation can produce energy as heat. Since adult humans possess significant amounts of active brown fat depots and their mass inversely correlates with adiposity, brown fat might play an important role in human obesity and energy homeostasis. New evidence suggests two types of thermogenic adipocytes with distinct developmental and anatomical features: classical brown adipocytes and beige adipocytes. Beige adipocyte has recently attracted special interest because of its ability to dissipate energy and the possible ability to differentiate itself from white adipocytes. Importantly, adult human brown adipocyte appears to be mainly composed of beige-like adipocytes, making this cell type an attractive therapeutic target for obesity and obesity-related diseases. Because many epigenetic changes can affect beige adipocyte differentiation, the knowledge of the circumstances that affect the development of beige adipocyte cells may be important for therapeutic strategies. In this review we discuss some recent observations arising from the great physiological capacity of these cells and their possible role as ways to treat obesity and diabetes mellitus type 2. PMID:27528872

  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

    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

  10. Re-expression of GATA2 Cooperates with Peroxisome Proliferator-activated Receptor-γ Depletion to Revert the Adipocyte Phenotype*S⃞

    OpenAIRE

    Schupp, Michael; Cristancho, Ana G; Lefterova, Martina I.; Hanniman, Elyisha A.; Briggs, Erika R.; Steger, David J; Qatanani, Mohammed; Curtin, Joshua C.; Schug, Jonathan; Ochsner, Scott A.; McKenna, Neil J; Lazar, Mitchell A.

    2009-01-01

    Nuclear peroxisome proliferator-activated receptor-γ (PPARγ) is required for adipocyte differentiation, but its role in mature adipocytes is less clear. Here, we report that knockdown of PPARγ expression in 3T3-L1 adipocytes returned the expression of most adipocyte genes to preadipocyte levels. Consistently, down-regulated but not up-regulated genes showed strong enrichment of PPARγ binding. Surprisingly, not all adipocyte genes were reversed, and the adipocyte morpho...

  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. Mesenchymal Stromal Cells Differentiating to Adipocytes Accumulate Autophagic Vesicles Instead of Functional Lipid Droplets.

    Science.gov (United States)

    Gruia, Alexandra T; Suciu, Maria; Barbu-Tudoran, Lucian; Azghadi, Seyed Mohammad Reza; Cristea, Mirabela I; Nica, Dragos V; Vaduva, Adrian; Muntean, Danina; Mic, Ani Aurora; Mic, Felix A

    2016-04-01

    Adult bone marrow mesenchymal stromal cells (BMSCs) can easily be differentiated into a variety of cells. In vivo transplantation of BMSCs-differentiated cells has had limited success, suggesting that these cells may not be fully compatible with the cells they are intended to replace in vivo. We investigated the structural and functional features of BMSCs-derived adipocytes as compared with adipocytes from adipose tissue, and the structure and functionality of lipid vesicles formed during BMSCs differentiation to adipocytes. Gas chromatography-mass spectrometry showed fatty acid composition of BMSCs-derived adipocytes and adipocytes from the adipose tissue to be very different, as is the lipid rafts composition, caveolin-1 expression, caveolae distribution in their membranes, and the pattern of expression of fatty acid elongases. Confocal microscopy confirmed the absence from BMSCs-derived adipocytes of markers of lipid droplets. BMSCs-derived adipocytes cannot convert deuterated glucose into deuterated species of fatty acids and cannot uptake the deuterated fatty acid-bovine serum albumin complexes from the culture medium, suggesting that intra-cellular accumulation of lipids does not occur by lipogenesis. We noted that BMSCs differentiation to adipocytes is accompanied by an increase in autophagy. Autophagic vesicles accumulate in the cytoplasm of BMSCs-derived adipocytes and their size and distribution resembles that of Nile Red-stained lipid vesicles. Stimulation of autophagy in BMSCs triggers the intra-cellular accumulation of lipids, while inhibition of autophagy prevents this accumulation. In conclusion, differentiation of BMSCs-derived adipocytes leads to intra-cellular accumulation of autophagic vesicles rather than functional lipid droplets, suggesting that these cells are not authentic adipocytes. J. Cell. Physiol. 231: 863-875, 2016. © 2015 Wiley Periodicals, Inc. PMID:26332160

  13. 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...

  14. The Adipocyte-Expressed Forkhead Transcription Factor Foxc2 Regulates Metabolism Through Altered Mitochondrial Function

    OpenAIRE

    Lidell, Martin E.; Seifert, Erin L.; Westergren, Rickard; Heglind, Mikael; Gowing, Adrienne; Sukonina, Valentina; Arani, Zahra; Itkonen, Paula; Wallin, Simonetta; Westberg, Fredrik; Fernandez-Rodriguez, Julia; Laakso, Markku; Nilsson, Tommy; Peng, Xiao-Rong; Harper, Mary-Ellen

    2011-01-01

    OBJECTIVE Previous findings demonstrate that enhanced expression of the forkhead transcription factor Foxc2 in adipose tissue leads to a lean and insulin-sensitive phenotype. These findings prompted us to further investigate the role of Foxc2 in the regulation of genes of fundamental importance for metabolism and mitochondrial function. RESEARCH DESIGN AND METHODS The effects of Foxc2 on expression of genes involved in mitochondriogenesis and mitochondrial function were assessed by quantitati...

  15. 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

    . The mechanisms by which EDCs direct preadipocytes to form adipocytes are poorly understood. Here, we examined transcriptional and epigenetic mechanisms underlying the induction of in vitro adipocyte differentiation by BDE-47. Quantitative high content microscopy revealed concentration-dependent enhanced...

  16. 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.

  17. Post-Irradiated Human Submandibular Glands Display High Collagen Deposition, Disorganized Cell Junctions, and an Increased Number of Adipocytes.

    Science.gov (United States)

    Nam, Kihoon; Maruyama, Christina L; Trump, Bryan G; Buchmann, Luke; Hunt, Jason P; Monroe, Marcus M; Baker, Olga J

    2016-06-01

    Salivary glands are vital for maintaining oral health. Head and neck radiation therapy is one of the most common causes of salivary gland hypofunction. Little is known about the structural changes that occur in salivary glands after radiation therapy. The aim of this study is to understand the structural changes that occur in post-irradiated human (submandibular gland [SMG]) as compared with untreated ones. We determined changes in epithelial polarity, presence of collagen deposition, and alteration in adipose tissue. We used formalin-fixed paraffin-embedded human SMG from two female subjects exposed to head and neck irradiation. We utilized hematoxylin and eosin staining and Masson's Trichrome staining. The immunostained tissue sections were examined using confocal microscopy. The number and size of adipocytes per tissue section were calculated using ImageJ, Prism, and SPSS software. Post-irradiated human SMG displayed high collagen deposition, disorganized cell junctions, and an increased number of adipocytes as compared with non-irradiated controls. These findings are important to improve our understanding of the individual risk and variation in radiation-related salivary gland dysfunction. PMID:27126825

  18. 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

    2016-08-16

    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 acid 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. 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

  19. 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

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

    Science.gov (United States)

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

    2016-08-01

    Type 2 diabetes follows a well-defined progressive pathogenesis, beginning with insulin resistance in metabolic tissues such as the adipose. Intracellular signaling downstream of insulin receptor activation regulates critical metabolic functions of adipose tissue, including glucose uptake, lipogenesis, lipolysis and adipokine secretion. Previous studies have used the aP2 promoter to drive Cre recombinase expression in adipose tissue. Insulin receptor (IR) knockout mice created using this aP2-Cre strategy (FIRKO mice) were protected from obesity and glucose intolerance. Later studies demonstrated the promiscuity of the aP2 promoter, casting doubts upon the tissue specificity of aP2-Cre models. It is our goal to use the increased precision of the Adipoq promoter to investigate adipocyte-specific IR function. Towards this end we generated an adipocyte-specific IR knockout (AIRKO) mouse using an Adipoq-driven Cre recombinase. Here we report AIRKO mice are less insulin sensitive throughout life, and less glucose tolerant than wild-type (WT) littermates at the age of 16 weeks. In contrast to WT littermates, the insulin sensitivity of AIRKO mice is unaffected by age or dietary regimen. At any age, AIRKO mice are comparably insulin resistant to old or obese WT mice and have a significantly reduced lifespan. Similar results were obtained when these phenotypes were re-examined in FIRKO mice. We also found that the AIRKO mouse is protected from high-fat diet-induced weight gain, corresponding with a 90% reduction in tissue weight of major adipose depots compared to WT littermates. Adipose tissue mass reduction is accompanied by hepatomegaly and increased hepatic steatosis. These data indicate that adipocyte IR function is crucial to systemic energy metabolism and has profound effects on adiposity, hepatic homeostasis and lifespan. PMID:27246738

  1. 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.

  2. mRNA concentrations of MIF in subcutaneous abdominal adipose cells are associated with adipocyte size and insulin action

    OpenAIRE

    Koska, Juraj; Stefan, Norbert; Dubois, Severine; Trinidad, Cathy; Considine, Robert V; Funahashi, Tohru; Bunt, Joy C.; Ravussin, Eric; Permana, Paska A.

    2009-01-01

    Objective To determine whether the mRNA concentrations of inflammation response genes in isolated adipocytes and in cultured preadipocytes are related to adipocyte size and in vivo insulin action in obese individuals. Design Cross-sectional inpatient study. Subjects Obese Pima Indians with normal glucose tolerance. Measurements Adipocyte diameter (by microscope technique; n=29), expression of candidate genes (by quantitative real-time PCR) in freshly isolated adipocytes (monocyte chemoattract...

  3. Adipocytes WNT5a mediated dedifferentiation: a possible target in pancreatic cancer microenvironment.

    Science.gov (United States)

    Zoico, Elena; Darra, Elena; Rizzatti, Vanni; Budui, Simona; Franceschetti, Guido; Mazzali, Gloria; Rossi, Andrea P; Fantin, Francesco; Menegazzi, Marta; Cinti, Saverio; Zamboni, Mauro

    2016-04-12

    A significant epidemiological association between obesity and pancreatic ductal adenocarcinoma (PDAC) has previously been described, as well as a correlation between the degree of pancreatic steatosis, PDAC risk and prognosis. The underlying mechanisms are still not completely known.After co-culture of 3T3-L1 adipocytes and MiaPaCa2 with an in vitro transwell system we observed the appearance of fibroblast-like cells, along with a decrease in number and size of remaining adipocytes. RT-PCR analyses of 3T3-L1 adipocytes in co-culture showed a decrease in gene expression of typical markers of mature adipocytes, in parallel with an increased expression of fibroblast-specific and reprogramming genes. We found an increased WNT5a gene and protein expression early in MiaPaCa2 cells in co-culture. Additionally, EMSA of c-Jun and AP1 in 3T3-L1 demonstrated an increased activation in adipocytes after co-culture. Treatment with WNT5a neutralizing antibody completely reverted the activation of c-Jun and AP1 observed in co-cultured adipocytes.Increasing doses of recombinant SFRP-5, a competitive inhibitor for WNT5a receptor, added to the co-culture medium, were able to block the dedifferentiation of adipocytes in co-culture.These data support a WNT5a-mediated dedifferentiation process with adipocytes reprogramming toward fibroblast-like cells that might profoundly influence cancer microenvironment. PMID:26958939

  4. Activation of TRPV2 negatively regulates the differentiation of mouse brown adipocytes.

    Science.gov (United States)

    Sun, Wuping; Uchida, Kunitoshi; Takahashi, Nobuyuki; Iwata, Yuko; Wakabayashi, Shigeo; Goto, Tsuyoshi; Kawada, Teruo; Tominaga, Makoto

    2016-09-01

    Transient receptor potential vanilloid 2 (TRPV2) acts as a Ca(2+)-permeable non-selective cation channel that has been reported to be sensitive to temperature, mechanical force, and some chemicals. We recently showed that TRPV2 is critical for maintenance of the thermogenic function of brown adipose tissue in mice. However, the involvement of TRPV2 in the differentiation of brown adipocytes remains unexplored. We found that the expression of TRPV2 was dramatically increased during the differentiation of brown adipocytes. Non-selective TRPV2 agonists (2-aminoethoxydiphenyl borate and lysophosphatidylcholine) inhibited the differentiation of brown adipocytes in a dose-dependent manner during the early stage of differentiation of brown adipocytes. The inhibition was rescued by a TRPV2-selective antagonist, SKF96365 (SKF). Mechanical force, which activates TRPV2, also inhibited the differentiation of brown adipocytes in a strength-dependent manner, and the effect was reversed by SKF. In addition, the inhibition of adipocyte differentiation by either TRPV2 ligand or mechanical stimulation was significantly smaller in the cells from TRPV2KO mice. Moreover, calcineurin inhibitors, cyclosporine A and FK506, partially reversed TRPV2 activation-induced inhibition of brown adipocyte differentiation. Thus, we conclude that TRPV2 might be involved in the modulation of brown adipocyte differentiation partially via a calcineurin pathway. PMID:27318696

  5. 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

    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 rosiglitazon...

  6. 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.

  7. 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.

  8. 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...

  9. 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.

  10. 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...

  11. 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...... adipose tissue mass and suppress the development of obesity in rodents by targeting a set of key regulatory transcription factors involved in both adipogensis and lipid homeostasis in mature adipocytes. The same set of factors are targeted by PUFAs of the n-6 family, but the cellular...

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

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    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.

  13. 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...... enhanced expression of the thermogenic genes and of genes expressed selectively in brown adipose tissue (iBAT) and in both interscapular BAT and WAT. ß3-adrenoceptor suppression blunted their expression only in WAT. Furthermore, cold acclimatization induced an increased WAT expression of the gene coding...... a mixed mitochondrioma with classic "brown" and "white" mitochondria, suggesting intermediate steps in the process of direct transformation of white into brown adipocytes (transdifferentiation). Quantitative electron microscopy disclosed that cold exposure (6°C for 10 days) did not induce an increase...

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

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    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.

  15. 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.

  16. Angiotensin II type 2 receptor promotes adipocyte differentiation and restores adipocyte size in high-fat/high-fructose diet-induced insulin resistance in rats.

    Science.gov (United States)

    Shum, Michaël; Pinard, Sandra; Guimond, Marie-Odile; Labbé, Sébastien M; Roberge, Claude; Baillargeon, Jean-Patrice; Langlois, Marie-France; Alterman, Mathias; Wallinder, Charlotta; Hallberg, Anders; Carpentier, André C; Gallo-Payet, Nicole

    2013-01-15

    This study was aimed at establishing whether specific activation of angiotensin II (ANG II) type 2 receptor (AT2R) modulates adipocyte differentiation and function. In primary cultures of subcutaneous (SC) and retroperitoneal (RET) preadipocytes, both AT2R and AT1R were expressed at the mRNA and protein level. Cells were stimulated with ANG II or the AT2R agonist C21/M24, alone or in the presence of the AT1R antagonist losartan or the AT2R antagonist PD123,319. During differentiation, C21/M24 increased PPARγ expression in both RET and SC preadipocytes while the number of small lipid droplets and lipid accumulation solely increased in SC preadipocytes. In mature adipocytes, C21/M24 decreased the mean size of large lipid droplets. Upon abolishment of AT2R expression using AT2R-targeted shRNAs, expressions of AT2R, aP2, and PPARγ remained very low, and cells were unable to differentiate. In Wistar rats fed a 6-wk high-fat/high-fructose (HFHF) diet, a significant shift toward larger adipocytes was observed in RET and SC adipose tissue depots. C21/M24 treatments for 6 wk restored normal adipocyte size distribution in both these tissue depots. Moreover, C21/M24 and losartan decreased hyperinsulinemia and improved insulin sensitivity impaired by HFHF diet. A strong correlation between adipocyte size area and glucose infusion rate during euglycemic-hyperinsulinemic clamp was observed. These results indicate that AT2R is involved in early adipocyte differentiation, while in mature adipocytes and in a model of insulin resistance AT2R activation restores normal adipocyte morphology and improves insulin sensitivity. PMID:23149621

  17. DNA Methylation Suppresses Leptin Gene in 3T3-L1 Adipocytes

    Science.gov (United States)

    Kuroda, Masashi; Tominaga, Ayako; Nakagawa, Kasumi; Nishiguchi, Misa; Sebe, Mayu; Miyatake, Yumiko; Kitamura, Tadahiro; Tsutsumi, Rie; Harada, Nagakatsu; Nakaya, Yutaka; Sakaue, Hiroshi

    2016-01-01

    Leptin is a key regulator of energy intake and expenditure. This peptide hormone is expressed in mouse white adipose tissue, but hardly expressed in 3T3-L1 adipocytes. Using bisulfite sequencing, we found that CpG islands in the leptin promoter are highly methylated in 3T3-L1cells. 5-azacytidine, an inhibitor of DNA methyltransferase, markedly increased leptin expression as pre-adipocytes matured into adipocytes. Remarkably, leptin expression was stimulated by insulin in adipocytes derived from precursor cells exposed to 5-azacytidine, but suppressed by thiazolidinedione and dexamethasone. In contrast, adipocytes derived from untreated precursor cells were unresponsive to both 5-azacytidine and hormonal stimuli, although lipid accumulation was sufficient to boost leptin expression in the absence of demethylation. Taken together, the results suggest that leptin expression in 3T3-L1 cells requires DNA demethylation prior to adipogenesis, transcriptional activation during adipogenesis, and lipid accumulation after adipogenesis. PMID:27494408

  18. 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.

  19. 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.

  20. 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

  1. Temperature induced modulation of lipid oxidation and lipid accumulation in palmitate-mediated 3T3-L1 adipocytes and 3T3-L1 adipocytes.

    Science.gov (United States)

    Lin, Xiaofen; Li, Yi; Leung, Polly Hangmei; Li, Jiashen; Hu, Junyan; Liu, Xuan; Li, Zhi

    2016-05-01

    Human skin temperature can vary widely depending on anatomical location and ambient temperature. It is also known that local changes in skin and subcutaneous temperature can affect fat metabolism. This study aimed to explore the potential effects of surrounding thermal environment on fat by investigating cell viability, lipid oxidation, and lipid accumulation in 3T3-L1 adipocytes and palmitate-treated adipocytes after 4h incubation. No significant differences of viability in 3T3-L1 adipocytes were detected under different temperature conditions. Despite no significant increase being observed under warm temperature (39°C) conditions, a similarly significant suppression of intracellular reactive oxygen species (ROS) and lipid peroxidation were found in 3T3-L1 adipocytes and palmitate-treated adipocytes under 4h exposure to cooler temperatures of 31-33°C (Psize of lipid droplets in 3T3-L1 adipocytes (Padipocytes. In the palmitate-induced adiposity model, although excessive ROS and lipid peroxidation has been attenuated by temperature decrease (Psize (P>0.05) and remedy the palmitate damage induced cell death (Padipocytes. PMID:27157327

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Chen Wang

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

  4. 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.

  5. Lats2 modulates adipocyte proliferation and differentiation via hippo signaling.

    Directory of Open Access Journals (Sweden)

    Yang An

    Full Text Available First identified in Drosophila and highly conserved in mammals, the Hippo pathway controls organ size. Lats2 is one of the core kinases of the Hippo pathway and plays major roles in cell proliferation by interacting with the downstream transcriptional cofactors YAP and TAZ. Although the function of the Hippo pathway and Lats2 is relatively well understood in several tissues and organs, less is known about the function of Lats2 and Hippo signaling in adipose development. Here, we show that Lats2 is an important modulator of adipocyte proliferation and differentiation via Hippo signaling. Upon activation, Lats2 phosphorylates YAP and TAZ, leading to their retention in the cytoplasm, preventing them from activating the transcription factor TEAD in the nucleus. Because TAZ remains in the cytoplasm, PPARγ regains its transcriptional activity. Furthermore, cytoplasmic TAZ acts as an inhibitor of Wnt signaling by suppressing DVL2, thereby preventing β-catenin from entering the nucleus to stimulate TCF/LEF transcriptional activity. The above effects contribute to the phenotype of repressed proliferation and accelerated differentiation in adipocytes. Thus, Lats2 regulates the balance between proliferation and differentiation during adipose development. Interestingly, our study provides evidence that Lats2 not only negatively modulates cell proliferation but also positively regulates cell differentiation.

  6. 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.

  7. 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.

  8. 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.

  9. Low-Dose Bisphenol-A Impairs Adipogenesis and Generates Dysfunctional 3T3-L1 Adipocytes.

    Science.gov (United States)

    Ariemma, Fabiana; D'Esposito, Vittoria; Liguoro, Domenico; Oriente, Francesco; Cabaro, Serena; Liotti, Antonietta; Cimmino, Ilaria; Longo, Michele; Beguinot, Francesco; Formisano, Pietro; Valentino, Rossella

    2016-01-01

    Environmental endocrine disruptors (EDCs), including bisphenol-A (BPA), have been recently involved in obesity and diabetes by dysregulating adipose tissue function. Our aim was to examine whether prolonged exposure to low doses of BPA could affect adipogenesis and adipocyte metabolic functions. Therefore, 3T3-L1 pre-adipocytes were cultured for three weeks with BPA 1 nM to mimic human environmental exposure. We evaluated BPA effect on cell proliferation, differentiation, gene expression and adipocyte metabolic function. BPA significantly increased pre-adipocyte proliferation (pdevelopment, may cause adipocyte metabolic dysfunction and inflammation, thereby increasing the risk of developing obesity-related diseases. PMID:26942597

  10. 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.

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

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    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.

  12. Adipocyte in vascular wall can induce the rupture of abdominal aortic aneurysm

    Science.gov (United States)

    Kugo, Hirona; Zaima, Nobuhiro; Tanaka, Hiroki; Mouri, Youhei; Yanagimoto, Kenichi; Hayamizu, Kohsuke; Hashimoto, Keisuke; Sasaki, Takeshi; Sano, Masaki; Yata, Tatsuro; Urano, Tetsumei; Setou, Mitsutoshi; Unno, Naoki; Moriyama, Tatsuya

    2016-01-01

    Abdominal aortic aneurysm (AAA) is a vascular disease involving the gradual dilation of the abdominal aorta. It has been reported that development of AAA is associated with inflammation of the vascular wall; however, the mechanism of AAA rupture is not fully understood. In this study, we investigated the mechanism underlying AAA rupture using a hypoperfusion-induced animal model. We found that the administration of triolein increased the AAA rupture rate in the animal model and that the number of adipocytes was increased in ruptured vascular walls compared to non-ruptured walls. In the ruptured group, macrophage infiltration and the protein levels of matrix metalloproteinases 2 and 9 were increased in the areas around adipocytes, while collagen-positive areas were decreased in the areas with adipocytes compared to those without adipocytes. The administration of fish oil, which suppresses adipocyte hypertrophy, decreased the number and size of adipocytes, as well as decreased the risk of AAA rupture ratio by 0.23 compared to the triolein administered group. In human AAA samples, the amount of triglyceride in the adventitia was correlated with the diameter of the AAA. These results suggest that AAA rupture is related to the abnormal appearance of adipocytes in the vascular wall. PMID:27499372

  13. Adipocyte in vascular wall can induce the rupture of abdominal aortic aneurysm.

    Science.gov (United States)

    Kugo, Hirona; Zaima, Nobuhiro; Tanaka, Hiroki; Mouri, Youhei; Yanagimoto, Kenichi; Hayamizu, Kohsuke; Hashimoto, Keisuke; Sasaki, Takeshi; Sano, Masaki; Yata, Tatsuro; Urano, Tetsumei; Setou, Mitsutoshi; Unno, Naoki; Moriyama, Tatsuya

    2016-01-01

    Abdominal aortic aneurysm (AAA) is a vascular disease involving the gradual dilation of the abdominal aorta. It has been reported that development of AAA is associated with inflammation of the vascular wall; however, the mechanism of AAA rupture is not fully understood. In this study, we investigated the mechanism underlying AAA rupture using a hypoperfusion-induced animal model. We found that the administration of triolein increased the AAA rupture rate in the animal model and that the number of adipocytes was increased in ruptured vascular walls compared to non-ruptured walls. In the ruptured group, macrophage infiltration and the protein levels of matrix metalloproteinases 2 and 9 were increased in the areas around adipocytes, while collagen-positive areas were decreased in the areas with adipocytes compared to those without adipocytes. The administration of fish oil, which suppresses adipocyte hypertrophy, decreased the number and size of adipocytes, as well as decreased the risk of AAA rupture ratio by 0.23 compared to the triolein administered group. In human AAA samples, the amount of triglyceride in the adventitia was correlated with the diameter of the AAA. These results suggest that AAA rupture is related to the abnormal appearance of adipocytes in the vascular wall. PMID:27499372

  14. 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.

  15. 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.

  16. The adipokine Chemerin induces lipolysis and adipogenesis in bovine intramuscular adipocytes.

    Science.gov (United States)

    Fu, Yuan-Yuan; Chen, Kun-Lin; Li, Hui-Xia; Zhou, Guang-Hong

    2016-07-01

    The adipokine Chemerin is reported to regulate adipogenesis and glucose homeostasis in vivo and in 3T3-L1 cells. Our team is focused on the role of Chemerin in metabolism and intramuscular adipocyte differentiation because intramuscular fat is the basic material for the formation of marbling in livestock and poultry meat. In this study, bovine intramuscular mature adipocytes were cultured in medium with Chemerin, and the process of lipolysis of mature adipocytes and the adipogenesis of de-differentiated preadipocytes were investigated. The results showed that Chemerin induced significant lipolytic metabolism in intramuscular mature adipocytes, indicated by increased levels of glycerol, FFA, and up-regulated expression of the lipolysis critical factors HSL, LPL, and leptin. Meanwhile, the expressions of adipogenic key factors PPARγ, C/EBPα, and A-FABP were decreased by Chemerin during lipolysis or dedifferentiation in mature adipocytes. The de-differentiated preadipocytes could re-differentiate into mature adipocytes. Intriguingly, the formation of cells' lipid droplets was promoted by Chemerin during preadipocyte differentiation. In addition, mRNA and protein expressions of PPARγ, C/EBPα, and A-FABP were up-regulated by Chemerin during preadipocytes differentiation. These results suggest that Chemerin promotes lipolysis in mature adipocytes and induces adipogenesis during preadipocyte re-differentiation, further indicating a dual role for Chemerin in the deposition of intramuscular fat in ruminant animals. PMID:27260300

  17. 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.

  18. Let-7i-5p represses brite adipocyte function in mice and humans.

    Science.gov (United States)

    Giroud, Maude; Karbiener, Michael; Pisani, Didier F; Ghandour, Rayane A; Beranger, Guillaume E; Niemi, Tarja; Taittonen, Markku; Nuutila, Pirjo; Virtanen, Kirsi A; Langin, Dominique; Scheideler, Marcel; Amri, Ez-Zoubir

    2016-01-01

    In response to cold or β3-adrenoreceptor stimulation brown adipose tissue (BAT) promotes non-shivering thermogenesis, leading to energy dissipation. BAT has long been thought to be absent or scarce in adult humans. The recent discovery of thermogenic brite/beige adipocytes has opened the way to development of novel innovative strategies to combat overweight/obesity and associated diseases. Thus it is of great interest to identify regulatory factors that govern the brite adipogenic program. Here, we carried out global microRNA (miRNA) expression profiling on human adipocytes to identify miRNAs that are regulated upon the conversion from white to brite adipocytes. Among the miRNAs that were differentially expressed, we found that Let-7i-5p was down regulated in brite adipocytes. A detailed analysis of the Let-7i-5p levels showed an inverse expression of UCP1 in murine and human brite adipocytes both in vivo and in vitro. Functional studies with Let-7i-5p mimic in human brite adipocytes in vitro revealed a decrease in the expression of UCP1 and in the oxygen consumption rate. Moreover, the Let-7i-5p mimic when injected into murine sub-cutaneous white adipose tissue inhibited partially β3-adrenergic activation of the browning process. These results suggest that the miRNAs Let-7i-5p participates in the recruitment and the function of brite adipocytes. PMID:27345691

  19. Transport and subcellular distribution characteristics of human erythrocyte glucose transporter fused in adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Inho.

    1990-01-01

    Purified human erythrocyte glucose transporters (HEGT) were incorporated into the rat epididymal adipocytes by polyethylene glycol (PEG)-induced fusion. The incorporation of HEGT was found to be dependent on both the molecular weight and the concentration of PEG. Optimal incorporation of HEGT occurred when 10% PEG 8000 was used. This incorporation was found to be proportional to the increasing amounts of HEGT used. Morphology tests showed very little surface adsorption of HEGT on adipocytes after fusion. Transport activity of fused HEGT was studied by measuring equilibrium exchange of 3-O-methylglucose. In adipocytes employed this fusion protocols, the transport rate increased significantly compared with cells treated under non-fusion conditions. This fold increase was directly proportional to the amount of HEGT recovered in the plasma membrane (PM). Furthermore, calculated turnover number of HEGT in fused adipocytes was as high as that of the native adipocyte glucose transporter (AGT). Subcellular distribution of HEGT in fused adipocytes was assessed using ({sup 3}H)cytochalasin B-labeled HEGT vesicles. HEGT was distributed in each subcellular organelle at specific ratios. This relative distribution was almost constant regardless of the amount of HEGT used. The distributions of lipid-labeled HEGT, fluid-phase endocytosed HEGT and free HEGT mixed to adipocyte homogenate were shown to be completely different from that of protein-labeled HEGT fusion.

  20. Transport and subcellular distribution characteristics of human erythrocyte glucose transporter fused in adipocytes

    International Nuclear Information System (INIS)

    Purified human erythrocyte glucose transporters (HEGT) were incorporated into the rat epididymal adipocytes by polyethylene glycol (PEG)-induced fusion. The incorporation of HEGT was found to be dependent on both the molecular weight and the concentration of PEG. Optimal incorporation of HEGT occurred when 10% PEG 8000 was used. This incorporation was found to be proportional to the increasing amounts of HEGT used. Morphology tests showed very little surface adsorption of HEGT on adipocytes after fusion. Transport activity of fused HEGT was studied by measuring equilibrium exchange of 3-O-methylglucose. In adipocytes employed this fusion protocols, the transport rate increased significantly compared with cells treated under non-fusion conditions. This fold increase was directly proportional to the amount of HEGT recovered in the plasma membrane (PM). Furthermore, calculated turnover number of HEGT in fused adipocytes was as high as that of the native adipocyte glucose transporter (AGT). Subcellular distribution of HEGT in fused adipocytes was assessed using [3H]cytochalasin B-labeled HEGT vesicles. HEGT was distributed in each subcellular organelle at specific ratios. This relative distribution was almost constant regardless of the amount of HEGT used. The distributions of lipid-labeled HEGT, fluid-phase endocytosed HEGT and free HEGT mixed to adipocyte homogenate were shown to be completely different from that of protein-labeled HEGT fusion

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

    International Nuclear Information System (INIS)

    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

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

    Directory of Open Access Journals (Sweden)

    Sang Min, Lee

    2008-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-15

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

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

    International Nuclear Information System (INIS)

    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

  5. 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.

  6. 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

  7. Chronic hyperinsulinemia reduces insulin sensitivity and metabolic functions of brown adipocyte.

    Science.gov (United States)

    Rajan, Sujith; Shankar, Kripa; Beg, Muheeb; Varshney, Salil; Gupta, Abhishek; Srivastava, Ankita; Kumar, Durgesh; Mishra, Raj K; Hussain, Zakir; Gayen, Jiaur R; Gaikwad, Anil N

    2016-09-01

    The growing pandemics of diabetes have become a real threat to world economy. Hyperinsulinemia and insulin resistance are closely associated with the pathophysiology of type 2 diabetes. In pretext of brown adipocytes being considered as the therapeutic strategy for the treatment of obesity and insulin resistance, we have tried to understand the effect of hyperinsulinemia on brown adipocyte function. We here with for the first time report that hyperinsulinemia-induced insulin resistance in brown adipocyte is also accompanied with reduced insulin sensitivity and brown adipocyte characteristics. CI treatment decreased expression of brown adipocyte-specific markers (such as PRDM16, PGC1α, and UCP1) and mitochondrial content as well as activity. CI-treated brown adipocytes showed drastic decrease in oxygen consumption rate (OCR) and spare respiratory capacity. Morphological study indicates increased accumulation of lipid droplets in CI-treated brown adipocytes. We have further validated these findings in vivo in C57BL/6 mice implanted with mini-osmotic insulin pump for 8weeks. CI treatment in mice leads to increased body weight gain, fat mass and impaired glucose intolerance with reduced energy expenditure and insulin sensitivity. CI-treated mice showed decreased BAT characteristics and function. We also observed increased inflammation and ER stress markers in BAT of CI-treated animals. The above results conclude that hyperinsulinemia has deleterious effect on brown adipocyte function, making it susceptible to insulin resistance. Thus, the above findings have greater implication in designing approaches for the treatment of insulin resistance and diabetes via recruitment of brown adipocytes. PMID:27340034

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    The recent insight that brown adipocytes and muscle cells share a common origin and in this respect are distinct from white adipocytes has spurred questions concerning the origin and molecular characteristics of the UCP1-expressing cells observed in classic white adipose tissue depots under certain...... physiological or pharmacological conditions. Examining precursors from the purest white adipose tissue depot (epididymal), we report here that chronic treatment with the peroxisome proliferator-activated receptor gamma agonist rosiglitazone promotes not only the expression of PGC-1alpha and mitochondriogenesis...... associated with classic brown adipocytes (Zic1, Lhx8, Meox2, and characteristically PRDM16) or for myocyte-associated genes (myogenin and myomirs (muscle-specific microRNAs)) and retain white fat characteristics such as Hoxc9 expression. Co-culture experiments verify that the UCP1-expressing cells...

  9. S6K1 Plays a Critical Role in Early Adipocyte Differentiation

    OpenAIRE

    Carnevalli, Larissa S.; Masuda, Kouhei; Frigerio, Francesca; Le Bacquer, Olivier; Um, Sung Hee; Gandin, Valentina; Topisirovic, Ivan; Sonenberg, Nahum; Thomas, George; Kozma, Sara C.

    2010-01-01

    Earlier, we reported that S6K1−/− mice have reduced body fat mass, elevated rates of lipolysis, severely decreased adipocyte size, and are resistant to high-fat-diet (HFD)-induced obesity. Here we report that adipocytes of S6K1−/− mice on a HFD, have the capacity to increase in size to a degree comparable to that of wild-type (WT) mice, but not in number, indicating an unexpected lesion in adipogenesis. Tracing this lesion revealed that S6K1 is dispensable for terminal adipocyte differentiati...

  10. FSP27 and PLIN1 interaction promotes the formation of large lipid droplets in human adipocytes

    OpenAIRE

    Grahn, Tan Hooi Min; Zhang, Yan; Lee, Mi-Jeong; Sommer, Andreia Gianotti; Mostoslavsky, Gustavo; Fried, Susan K.; Greenberg, Andrew S.; Puri, Vishwajeet

    2013-01-01

    Human adipocytes express high levels of two distinct lipid droplet proteins, Fat Specific Protein 27 (FSP27; also called CIDEC), a member of the CIDE family, and perilipin1 (PLIN1), a member of the PAT family. Both proteins play a role in fat metabolism in adipocytes, but how they interact is not known. Our present study demonstrates that FSP27 and PLIN1 co-localize and interact in cultured human primary adipocytes. We also found that the C-terminal domain of FSP27, aa 120–220, interacts with...

  11. Consequence of Menin Deficiency in Mouse Adipocytes Derived by In Vitro Differentiation

    OpenAIRE

    Parekh, Vaishali I.; Modali, Sita D.; Desai, Shruti S.; Agarwal, Sunita K

    2015-01-01

    Lipoma in patients with the multiple endocrine neoplasia type 1 (MEN1) syndrome is a type of benign fat-cell tumor that has biallelic inactivation of MEN1 that encodes menin and could serve as a model to investigate normal and pathologic fat-cell (adipocyte) proliferation and function. The role of menin and its target genes in adipocytes is not known. We used in vitro differentiation to derive matched normal and menin-deficient adipocytes from wild type (WT) and menin-null (Men1-KO) mouse emb...

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

    OpenAIRE

    Yang Jiao; Jingying Zhang; Lunjie Lu; Jiaying Xu; Liqiang Qin

    2016-01-01

    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. Us...

  13. 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.

  14. 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.

  15. Glucose metabolism and effect of acetate in ovine adipocytes.

    Science.gov (United States)

    Yang, Y T; White, L S; Muir, L A

    1982-08-01

    Isolated ovine adipocytes were incubated in vitro with specifically labeled 14C-glucose in the presence or absence of acetate. The flux patterns of glucose carbon through major metabolic pathways were estimated. When glucose was added as the sole substrate, approximately equal portions of glucose carbon (10%) were oxidized to CO2 in the pentose phosphate pathway, in the pyruvate dehydrogenase reaction and in the citrate cycle. Fifteen percent of the glucose carbon was incorporated into fatty acids and 43% was released as lactate and pyruvate. Addition of acetate to the medium increased glucose carbon uptake by 1.5-fold. Most of this increase was accounted for by a sevenfold increase in the activity of the pentose phosphate pathway. Acetate increased glucose carbon fluxes via pentose phosphate pathway to triose phosphates, from triose phosphate to pyruvate, into glyceride glycerol, into lactate and pyruvate and into pyruvate dehydrogenase and citrate cycle CO2. Glucose carbon incorporated into fatty acids was decreased 50% by acetate while, carbon fluxes through the phosphofructokinase-aldolase reactions were not significantly increased. Results of this study suggest that, when glucose is the sole substrate, the conversion of glucose to fatty acids in ovine adipocytes may not be limited by the maximum capacity of hexokinase, the pentose phosphate pathway or enzymes involved in the conversion of triose phosphates to pyruvate and of pyruvate to fatty acid. Acetate increased glucose utilization apparently by increasing activity of the pentose phosphate pathway as a result of enhanced NADPH utilization for fatty acid synthesis. PMID:7142048

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

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    Francisco Javier Ruiz-Ojeda

    Full Text Available 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.

  17. 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

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

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    Pedro A Pérez-Mancera

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

  19. 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

  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 major energy store and brown adipocytes being potent energy-dissipaters through thermogenesis. Yet, little is known about factors differentially regulating the formation of white and brown fat cells. Members of the retinoblastoma protein family (pRB, p107, p130) have been implicated in the regulation...... of adipocyte differentiation, and expression and phosphorylation of the three retinoblastoma family proteins oscillate in a characteristic manner during differentiation of the white preadipocyte cell line 3T3-L1. We have recently demonstrated a surprising function of the retinoblastoma protein...... in the regulation of white versus brown adipocyte differentiation in vitro and possibly in vivo. Here we summarize the current knowledge on the retinoblastoma protein in fat cells, with particular emphasis on its potential role in adipocyte lineage commitment and differentiation....

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

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    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.

  2. 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.

  3. 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.

  4. 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

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

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    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.

  6. 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

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

    International Nuclear Information System (INIS)

    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

  8. 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

  9. Curcumin and resveratrol inhibit nuclear factor-kappaB-mediated cytokine expression in adipocytes

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    Orlando Robert A

    2008-06-01

    Full Text Available Abstract Background Adipocytes express inflammatory mediators that contribute to the low-level, chronic inflammation found in obese subjects and have been linked to the onset of cardiovascular disorders and insulin resistance associated with type 2 diabetes mellitus. A reduction in inflammatory gene expression in adipocytes would be expected to reverse this low-level, inflammatory state and improve cardiovascular function and insulin sensitivity. The natural products, curcumin and resveratrol, are established anti-inflammatory compounds that mediate their effects by inhibiting activation of NF-κB signaling. In the present study, we examined if these natural products can inhibit NF-κB activation in adipocytes and in doing so reduce cytokine expression. Methods Cytokine (TNF-α, IL-1β, IL-6 and COX-2 gene expression in 3T3-L1-derived adipocytes was measured by quantitative real-time PCR (qRT-PCR with or without TNFα-stimulation. Cytokine protein and prostaglandin E2 (PGE2 expression were measured by ELISA. Effects of curcumin and resveratrol were evaluated by treating TNFα-stimulated adipocytes with each compound and 1 assessing the activation state of the NF-κB signaling pathway and 2 measuring inflammatory gene expression by qRT-PCR and ELISA. Results Both preadipocytes and differentiated adipocytes express the genes for TNF-α, IL-6, and COX-2, key mediators of the inflammatory response. Preadipocytes were also found to express IL-1β; however, IL-1β expression was absent in differentiated adipocytes. TNF-α treatment activated NF-κB signaling in differentiated adipocytes by inducing IκB degradation and NF-κB translocation to the nucleus, and as a result increased IL-6 (6-fold and COX-2 (2.5-fold mRNA levels. TNF-α also activated IL-1β gene expression in differentiated adipocytes, but had no effect on endogenous TNF-α mRNA levels. No detectable TNFα or IL-1β was secreted by adipocytes. Curcumin and resveratrol treatment inhibited

  10. Preadipocyte transplantation: an in vivo study of direct leptin signaling on adipocyte morphogenesis and cell size

    OpenAIRE

    Guo, Kaiying; Mogen, Jonathan; Struzzi, Samuel; Zhang, Yiying

    2009-01-01

    Leptin has profound effects on adipose tissue metabolism. However, it remains unclear whether direct leptin signaling in adipocytes is involved. We addressed this question by transplanting inguinal adipose tissue stromal vascular cells (SVCs) from 4- to 5-wk-old wild-type (WT) and leptin receptor-deficient [Leprdb/db (db)] mice to inguinal and sternal subcutaneous sites in Ncr nude mice. Both WT and db SVCs gave rise to mature adipocytes with normal morphologies 3 mo after the transplantation...

  11. Receptor for Advanced Glycation End Products Regulates Adipocyte Hypertrophy and Insulin Sensitivity in Mice

    OpenAIRE

    Monden, Masayo; Koyama, Hidenori; Otsuka, Yoshiko; Morioka, Tomoaki; Mori, Katsuhito; Shoji, Takuhito; Mima, Yohei; Motoyama, Koka; Fukumoto, Shinya; Shioi, Atsushi; Emoto, Masanori; Yamamoto, Yasuhiko; Yamamoto, Hiroshi; Nishizawa, Yoshiki; Kurajoh, Masafumi

    2013-01-01

    Receptor for advanced glycation end products (RAGE) has been shown to be involved in adiposity as well as atherosclerosis even in nondiabetic conditions. In this study, we examined mechanisms underlying how RAGE regulates adiposity and insulin sensitivity. RAGE overexpression in 3T3-L1 preadipocytes using adenoviral gene transfer accelerated adipocyte hypertrophy, whereas inhibitions of RAGE by small interfering RNA significantly decrease adipocyte hypertrophy. Furthermore, double knockdown o...

  12. Mesoderm-specific transcript (MEST) is a negative regulator of human adipocyte differentiation

    OpenAIRE

    Karbiener, M; Glantschnig, C; Pisani, D. F.; Laurencikiene, J.; Dahlman, I; Herzig, S; Amri, E-Z; Scheideler, M

    2015-01-01

    Background: A growing body of evidence suggests that many downstream pathologies of obesity are amplified or even initiated by molecular changes within the white adipose tissue (WAT). Such changes are the result of an excessive expansion of individual white adipocytes and could potentially be ameliorated via an increase in de novo adipocyte recruitment (adipogenesis). Mesoderm-specific transcript (MEST) is a protein with a putative yet unidentified enzymatic function and has previously been s...

  13. Differential Effect of Weight Loss on Adipocyte Size Subfractions in Patients With Type 2 Diabetes

    OpenAIRE

    Pasarica, Magdalena; Tchoukalova, Yourka D.; Heilbronn, Leonie K.; Fang, Xiaobing; Albu, Jeanine B.; Kelley, David E.; Smith, Smith R.; Ravussin, Eric

    2009-01-01

    The size of adipocytes influences their function suggesting a differential responsiveness to intervention. We hypothesized that weight loss in patients with type 2 diabetes mellitus (T2DM) predominantly decreases the size of large and very-large adipocyte subfractions in parallel with beneficial changes in serum adipokines and improved insulin sensitivity. A total of 44 volunteers from the Look Action for Health in Diabetes trial, who lost weight after 1-year of intense lifestyle intervention...

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

    International Nuclear Information System (INIS)

    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

  15. Effect of Thyroid Status on Insulin Action in Rat Adipocytes and Skeletal Muscle

    OpenAIRE

    Czech, Michael P.; Malbon, Craig C.; Kerman, Keith; Gitomer, Wendy; Pilch, Paul F.

    1980-01-01

    Isolated adipocytes and soleus muscles prepared from mature rats, rendered hypothyroid by a low iodine diet and propylthiouracil, markedly resisted the ability of insulin to increase glucose utilization. In adipocytes, the sum of basal d-(1-14C)-glucose conversion to CO2, glyceride-glycerol, and fatty acid was unaltered by hypothyroidism, although conversion to fatty acid was decreased. The response of each of these metabolic pathways to insulin at all concentrations tested was greatly dimini...

  16. Distinct Mechanisms Regulate ATGL-Mediated Adipocyte Lipolysis by Lipid Droplet Coat Proteins

    OpenAIRE

    Yang, Xingyuan; Heckmann, Bradlee L; Zhang, Xiaodong; Smas, Cynthia M.; Liu, Jun

    2012-01-01

    Adipose triglyceride lipase (ATGL) is the key triacylglycerol hydrolase in adipocytes. The precise mechanisms by which ATGL action is regulated by lipid droplet (LD) coat proteins and responds to hormonal stimulation are incompletely defined. By combining usage of loss- and gain-of-function approaches, we sought to determine the respective roles of perilipin 1 and fat-specific protein 27 (FSP27) in the control of ATGL-mediated lipolysis in adipocytes. Knockdown of endogenous perilipin 1 expre...

  17. Cancer-Associated Adipocytes Exhibit an ActivatedPhenotype and Contribute to Breast Cancer Invasion

    OpenAIRE

    2011-01-01

    Early local tumor invasion in breast cancer results in a likely encounter between cancer cells and matureadipocytes, but the role of these fat cells in tumor progression remains unclear. We show that murine and humantumor cells cocultivated with mature adipocytes exhibit increased invasive capacities in vitro and in vivo, usingan original two-dimensional coculture system. Likewise, adipocytes cultivated with cancer cells also exhibit analtered phenotype in terms of delipidation and decreased ...

  18. 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.

  19. 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

  20. 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...

  1. 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.

  2. 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

  3. Rab18 Dynamics in Adipocytes in Relation to Lipogenesis, Lipolysis and Obesity

    OpenAIRE

    Pulido, Marina R.; Alberto Diaz-Ruiz; Yolanda Jiménez-Gómez; Socorro Garcia-Navarro; Francisco Gracia-Navarro; Francisco Tinahones; José López-Miranda; Gema Frühbeck; Rafael Vázquez-Martínez; Malagón, Maria M.

    2011-01-01

    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 stat...

  4. 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

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

    Directory of Open Access Journals (Sweden)

    Nerurkar Vivek R

    2010-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Israel Pérez-Torres

    2016-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    Pérez-Torres, Israel; Guarner-Lans, Verónica; Zúñiga-Muñoz, Alejandra; 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

  8. 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.

  9. Mitigation of isolation-associated adipocyte interleukin-6 secretion following rapid dissociation of adipose tissue.

    Science.gov (United States)

    Thompson, Airlia C S; Nuñez, Martha; Davidson, Ryan; Horm, Teresa; Schnittker, Karina; Hart, Madeline V; Suarez, Allen M; Tsao, Tsu-Shuen

    2012-12-01

    Primary adipocyte isolation by collagenase digestion is a widely used technique to study metabolic regulation and insulin action in adipocytes. However, induction of a proinflammatory response characterized by enhanced secretion of interleukin (IL)-6 has been tightly linked to the isolation process itself. To test the hypothesis that the shaking mechanical force exerted on adipocytes stimulates inflammation during isolation, rat primary adipocytes were prepared by collagenase digestion in orbital shaking incubators maintained at varying speeds. Contrary to expectation, the isolation-induced release of IL-6 was attenuated by increasing the rotational speed of digestion and the concentration of collagenase, both of which resulted in rapid dissociation of adipocytes from the vasculature. In addition, the attenuation of IL-6 secretion was associated with decreased phosphorylation of the stress-related p38 mitogen-activated protein kinase (p38 MAPK) and preserved insulin action. The data suggest that optimization of parameters including, but not limited to, mincing technique, time of digestion, and collagenase concentration will make it possible to isolate primary adipocytes without activation of a proinflammatory response leading to elevated secretion of IL-6. PMID:22911046

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

    International Nuclear Information System (INIS)

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

  11. Nucleotide-binding Oligomerization Domain-1 Ligand Induces Inflammation and Attenuates Glucose Uptake in Human Adipocytes

    Institute of Scientific and Technical Information of China (English)

    Yi-jun Zhou; Ai Li; Yu-ling Song; Yan Li; Hui Zhou

    2012-01-01

    Objective To investigate the effects of stimulant for nucleotide-binding oligomerization domain 1 (NOD1) on secretion of proinflammatory chemokine/cytokines and insulin-dependent glucose uptake in human differentiated adipocytes.Methods Adipose tissues were obtained from patients undergoing liposuction.Stromal vascular cells were extracted and differentiated into adipocytes.A specific ligand for NOD1,was administered to human adipocytes in culture.Nuclear factor-κB transcriptional activity and proinflammatory chemokine/cytokines production were determined by reporter plasmid assay and enzyme-linked immunosorbent assay,respectively.Insulin-stimulated glucose uptake was measured by 2-deoxy-D-[3H]glucose uptake assay.Furthermore,chemokine/cytokine secretion and glucose uptake in adipocytes transfected with small interfering RNA (siRNA) targeting NOD1 upon stimulation of NOD1 ligand were analyzed.Results Nuclear factor-κB transcriptional activity and monocyte chemoattractant protein-1 (MCP-1),interleukin (IL)-6,and IL-8 secretion in human adipocytes were markedly increased stimulated with NOD1 ligand (all P<0.01).Insulin-induced glucose uptake was decreased upon the activation of NOD1 (P<0.05).NOD1 gene silencing by siRNA reduced NOD1 ligand-induced MCP-1,IL-6,and IL-8 release and increased insulin-induced glucose uptake (all P<0.05).Conclusion NOD1 activation in adipocytes might be implicated in the onset of insulin resistance.

  12. Exocytosis of macrophage lysosomes leads to digestion of apoptotic adipocytes and foam cell formation.

    Science.gov (United States)

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

    2016-06-01

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

  13. FoxO1 antagonist suppresses autophagy and lipid droplet growth in adipocytes.

    Science.gov (United States)

    Liu, Longhua; Zheng, Louise D; Zou, Peng; Brooke, Joseph; Smith, Cayleen; Long, Yun Chau; Almeida, Fabio A; Liu, Dongmin; Cheng, Zhiyong

    2016-08-01

    Obesity and related metabolic disorders constitute one of the most pressing heath concerns worldwide. Increased adiposity is linked to autophagy upregulation in adipose tissues. However, it is unknown how autophagy is upregulated and contributes to aberrant adiposity. Here we show a FoxO1-autophagy-FSP27 axis that regulates adipogenesis and lipid droplet (LD) growth in adipocytes. Adipocyte differentiation was associated with upregulation of autophagy and fat specific protein 27 (FSP27), a key regulator of adipocyte maturation and expansion by promoting LD formation and growth. However, FoxO1 specific inhibitor AS1842856 potently suppressed autophagy, FSP27 expression, and adipocyte differentiation. In terminally differentiated adipocytes, AS1842856 significantly reduced FSP27 level and LD size, which was recapitulated by autophagy inhibitors (bafilomycin-A1 and leupeptin, BL). Similarly, AS1842856 and BL dampened autophagy activity and FSP27 expression in explant cultures of white adipose tissue. To our knowledge, this is the first study addressing FoxO1 in the regulation of adipose autophagy, shedding light on the mechanism of increased autophagy and adiposity in obese individuals. Given that adipogenesis and adipocyte expansion contribute to aberrant adiposity, targeting the FoxO1-autophagy-FSP27 axis may lead to new anti-obesity options. PMID:27260854

  14. Adipocyte lipolysis-stimulated interleukin-6 production requires sphingosine kinase 1 activity.

    Science.gov (United States)

    Zhang, Wenliang; Mottillo, Emilio P; Zhao, Jiawei; Gartung, Allison; VanHecke, Garrett C; Lee, Jen-Fu; Maddipati, Krishna R; Xu, Haiyan; Ahn, Young-Hoon; Proia, Richard L; Granneman, James G; Lee, Menq-Jer

    2014-11-14

    Adipocyte lipolysis can increase the production of inflammatory cytokines such as interleukin-6 (IL-6) that promote insulin resistance. However, the mechanisms that link lipolysis with inflammation remain elusive. Acute activation of β3-adrenergic receptors (ADRB3) triggers lipolysis and up-regulates production of IL-6 in adipocytes, and both of these effects are blocked by pharmacological inhibition of hormone-sensitive lipase. We report that stimulation of ADRB3 induces expression of sphingosine kinase 1 (SphK1) and increases sphingosine 1-phosphate production in adipocytes in a manner that also depends on hormone-sensitive lipase activity. Mechanistically, we found that adipose lipolysis-induced SphK1 up-regulation is mediated by the c-Jun N-terminal kinase (JNK)/activating protein-1 signaling pathway. Inhibition of SphK1 by sphingosine kinase inhibitor 2 diminished the ADRB3-induced IL-6 production both in vitro and in vivo. Induction of IL-6 by ADRB3 activation was suppressed by siRNA knockdown of Sphk1 in cultured adipocytes and was severely attenuated in Sphk1 null mice. Conversely, ectopic expression of SphK1 increased IL-6 expression in adipocytes. Collectively, these data demonstrate that SphK1 is a critical mediator in lipolysis-triggered inflammation in adipocytes. PMID:25253697

  15. 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.

  16. Smectite alteration

    International Nuclear Information System (INIS)

    This report contains the proceedings of a second workshop in Washington DC December 8-9, 1983 on the alteration of smectites intended for use as buffer materials in the long-term containment of nuclear wastes. It includes extended summaries of all presentations and a transcript of the detailed scientific discussion. The discussions centered on three main questions: What is the prerequisite for and what is the precise mechanism by which smectite clays may be altered to illite. What are likly sources of potassium with respect to the KBS project. Is it likely that the conversion of smectite to illite will be of importance in the 10 5 to the 10 6 year time frame. The workshop was convened to review considerations and conclusions in connection to these questions and also to broaden the discussion to consider the use of smectite clays as buffer materials for similar applications in different geographical and geological settings. SKBF/KBS technical report 83-03 contains the proceedings from the first workshop on these matters that was held at the State University of New York, Buffalo May 26-27, 1982. (Author)

  17. 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

  18. Loss of CD24 in Mice Leads to Metabolic Dysfunctions and a Reduction in White Adipocyte Tissue

    OpenAIRE

    Fairbridge, Nicholas A; Southall, Thomas M.; Craig Ayre, D.; Yumiko Komatsu; Paula I Raquet; Brown, Robert J.; Edward Randell; Kovacs, Christopher S.; Christian, Sherri L.

    2015-01-01

    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 vi...

  19. Large adipocytes function as antigen-presenting cells to activate CD4+ T cells via upregulating MHCII in obesity

    OpenAIRE

    Xiao, L; Yang, X.; Lin, Y.; Li, S.; Jiang, J; Qian, S.(State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China); Tang, Q; He, R; Li, X.

    2015-01-01

    Background/Objectives: Although obesity is associated with low-grade inflammation and metabolic disorders, clinical studies suggested some obese people were metabolically healthy with smaller adipocyte size compared with metabolically abnormal obese (MAO). This indicated adipocyte size may be an important predictor underlay the distinction between MAO and metabolically healthy obese. As recent study has shown that adipocytes expressed class II major histocompatibility complex (MHCII), which f...

  20. Inhibition of Adipogenesis and Induction of Apoptosis and Lipolysis by Stem Bromelain in 3T3-L1 Adipocytes

    OpenAIRE

    Sandeep Dave; Naval Jit Kaur; Ravikanth Nanduri; H Kitdorlang Dkhar; Ashwani Kumar; Pawan Gupta

    2012-01-01

    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 s...

  1. 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.

  2. 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.

  3. Functional Analysis of Long-chain Acyl-CoA Synthetase 1 in 3T3-L1 Adipocytes*

    OpenAIRE

    Lobo, Sandra; Wiczer, Brian M.; Bernlohr, David A

    2009-01-01

    ACSL1 (acyl-CoA synthetase 1), the major acyl-CoA synthetase of adipocytes, has been proposed to function in adipocytes as mediating free fatty acid influx, esterification, and storage as triglyceride. To test this hypothesis, ACSL1 was stably silenced (knockdown (kd)) in 3T3-L1 cells, differentiated into adipocytes, and evaluated for changes in lipid metabolism. Surprisingly, ACSL1-silenced adipocytes exhibited no significant changes in basal or insulin-stimulated long-chain fatty acid uptak...

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-01-01

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

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

    International Nuclear Information System (INIS)

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

  7. 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.

  8. 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 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. PMID:27251439

  9. 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.

  10. Lotus leaf extract and L-carnitine influence different processes during the adipocyte life cycle

    Directory of Open Access Journals (Sweden)

    Stäb Franz

    2010-08-01

    Full Text Available Abstract Background The cellular and molecular mechanisms of adipose tissue biology have been studied extensively over the last two decades. Adipose tissue growth involves both an increase in fat cell size and the formation of mature adipocytes from precursor cells. To investigate how natural substances influence these two processes, we examined the effects of lotus leaf extract (Nelumbo nucifera-extract solution obtained from Silab, France and L-carnitine on human preadipocytes and adipocytes. Methods For our in vitro studies, we used a lotus leaf extract solution alone or in combination with L-carnitine. Utilizing cultured human preadipocytes, we investigated lotus leaf extract solution-induced inhibition of triglyceride incorporation during adipogenesis and possible effects on cell viability. Studies on human adipocytes were performed aiming to elucidate the efficacy of lotus leaf extract solution to stimulate lipolytic activity. To further characterize lotus leaf extract solution-mediated effects, we determined the expression of the transcription factor adipocyte determination and differentiation factor 1 (ADD1/SREBP-1c on the RNA- and protein level utilizing qRT-PCR and immunofluorescence analysis. Additionally, the effect of L-carnitine on beta-oxidation was analyzed using human preadipocytes and mature adipocytes. Finally, we investigated additive effects of a combination of lotus leaf extract solution and L-carnitine on triglyceride accumulation during preadipocyte/adipocyte differentiation. Results Our data showed that incubation of preadipocytes with lotus leaf extract solution significantly decreased triglyceride accumulation during adipogenesis without affecting cell viability. Compared to controls, adipocytes incubated with lotus leaf extract solution exhibited a significant increase in lipolysis-activity. Moreover, cell populations cultivated in the presence of lotus leaf extract solution showed a decrease in adipocyte

  11. Coprinus comatus cap inhibits adipocyte differentiation via regulation of PPARγ and Akt signaling pathway.

    Directory of Open Access Journals (Sweden)

    Hyoung Joon Park

    Full Text Available This study assessed the effects of Coprinus comatus cap (CCC on adipogenesis in 3T3-L1 adipocytes and the effects of CCC on the development of diet-induced obesity in rats. Here, we showed that the CCC has an inhibitory effect on the adipocyte differentiation of 3T3-L1 cells, resulting in a significant decrease in lipid accumulation through the downregulation of several adipocyte specific-transcription factors, including CCAAT/enhancer binding protein β, C/EBPδ, and peroxisome proliferator-activated receptor gamma (PPARγ. Moreover, treatment with CCC during adipocyte differentiation induced a significant down-regulation of PPARγ and adipogenic target genes, including adipocyte protein 2, lipoprotein lipase, and adiponectin. Interestingly, the CCC treatment of the 3T3-L1 adipocytes suppressed the insulin-stimulated Akt and GSK3β phosphorylation, and these effects were stronger in the presence of an inhibitor of Akt phosphorylation, LY294002, suggesting that CCC inhibited adipocyte differentiation through the down-regulation of Akt signaling. In the animal study, CCC administration significantly reduced the body weight and adipose tissue weight of rats fed a high fat diet (HFD and attenuated lipid accumulation in the adipose tissues of the HFD-induced obese rats. The size of the adipocyte in the epididymal fat of the CCC fed rats was significantly smaller than in the HFD rats. CCC treatment significantly reduced the total cholesterol and triglyceride levels in the serum of HFD rats. These results strongly indicated that the CCC-mediated decrease in body weight was due to a reduction in adipose tissue mass. The expression level of PPARγ and phospho-Akt was significantly lower in the CCC-treated HFD rats than that in the HFD obesity rats. These results suggested that CCC inhibited adipocyte differentiation by the down-regulation of major transcription factor involved in the adipogenesis pathway including PPARγ through the regulation of the

  12. Computer image analysis of intramuscular adipocytes and marbling in the longissimus muscle of cattle.

    Science.gov (United States)

    Yang, X J; Albrecht, E; Ender, K; Zhao, R Q; Wegner, J

    2006-12-01

    The deposition of fat in muscle, recognized by the consumer as marbling, is an important meat quality trait. The objective of the study was to provide additional insights into the quantitative extent of marbling by means of computer image analysis. Fifty-one F(2) generation German Holstein and Charolais crossbreed cattle, 18 mo of age, were used to determine relationships among marbling traits, adipocyte size, and the amount of adipose tissue in different depots. Differences were recorded among the size of i.m. adipocytes in different groups of marbling flecks, divided according to the location in the muscle cross-section and to the size of the marbling flecks. The results showed positive correlation between i.m. adipocyte size and the weight of s.c. fat, intestinal fat, omental fat, and perirenal fat (r = 0.50, 0.61, 0.70, and 0.63, respectively, P < 0.001). The i.m. adipocyte size was correlated with i.m. fat content, number of marbling flecks, proportion of marbling fleck area, and total length of marbling flecks (r = 0.71, 0.44, 0.62, and 0.55, respectively, P < 0.01). The number of marbling flecks was also correlated with i.m. fat content, proportion of marbling fleck area, and total length of marbling flecks (r = 0.58, 0.62, and 0.91, P < 0.01, respectively). The ventral marbling flecks had a 5-fold larger fleck area, 4-fold more adipocytes, and larger adipocytes (P < 0.001). Larger marbling flecks contained larger adipocytes (P < 0.001). Moreover, compared with the small marbling flecks, there was a 48-fold larger fleck area and 26-fold more adipocytes in the large marbling flecks. The results indicate that i.m. fat deposition increases concurrently with the other fat depots but is still independent. Furthermore, the i.m. fat is preferentially deposited in the ventral area of LM. Although the i.m. adipocyte size has an important effect on the traits of marbling flecks, cell number plays a greater role in i.m. fat deposition than cell size. PMID:17093217

  13. Enhanced accumulation of adipocytes in bone marrow stromal cells in the presence of increased extracellular and intracellular [Ca2+

    International Nuclear Information System (INIS)

    Highlights: ► High [Ca2+]o enhances adipocyte accumulation in the presence of adipogenic inducers. ► High [Ca2+]o enhances both proliferation and adipocyte differentiation in BMSCs. ► High [Ca2+]o induces an increase in [Ca2+]o in BMSCs. ► An intracellular Ca2+ chelator suppresses the enhancement in adipocyte accumulation. ► Controlling [Ca2+]o may govern the balance of adipocyte and osteoblast development. -- Abstract: The bone marrow stroma contains osteoblasts and adipocytes that have a common precursor: the pluripotent mesenchymal stem cell found in bone marrow stromal cells (BMSCs). Local bone marrow Ca2+ levels can reach high concentrations due to bone resorption, which is one of the notable features of the bone marrow stroma. Here, we describe the effects of high [Ca2+]o on the accumulation of adipocytes in the bone marrow stroma. Using primary mouse BMSCs, we evaluated the level of adipocyte accumulation by measuring Oil Red O staining and glycerol-3-phosphate dehydrogenase (GPDH) activity. High [Ca2+]o enhanced the accumulation of adipocytes following treatment with both insulin and dexamethasone together but not in the absence of this treatment. This enhanced accumulation was the result of both the accelerated proliferation of BMSCs and their differentiation into adipocytes. Using the fura-2 method, we also showed that high [Ca2+]o induces an increase in [Ca2+]i. An intracellular Ca2+ chelator suppressed the enhancement in adipocyte accumulation due to increased [Ca2+]o in BMSCs. These data suggest a new role for extracellular Ca2+ in the bone marrow stroma: increased [Ca2+]o induces an increase in [Ca2+]i levels, which in turn enhances the accumulation of adipocytes under certain conditions.

  14. Antiobesity Action of ACAM by Modulating the Dynamics of Cell Adhesion and Actin Polymerization in Adipocytes.

    Science.gov (United States)

    Murakami, Kazutoshi; Eguchi, Jun; Hida, Kazuyuki; Nakatsuka, Atsuko; Katayama, Akihiro; Sakurai, Miwa; Choshi, Haruki; Furutani, Masumi; Ogawa, Daisuke; Takei, Kohji; Otsuka, Fumio; Wada, Jun

    2016-05-01

    Coxsackie virus and adenovirus receptor-like membrane protein (CLMP) was identified as the tight junction-associated transmembrane protein of epithelial cells with homophilic binding activities. CLMP is also recognized as adipocyte adhesion molecule (ACAM), and it is upregulated in mature adipocytes in rodents and humans with obesity. Here, we present that aP2 promoter-driven ACAM transgenic mice are protected from obesity and diabetes with the prominent reduction of adipose tissue mass and smaller size of adipocytes. ACAM is abundantly expressed on plasma membrane of mature adipocytes and associated with formation of phalloidin-positive polymerized form of cortical actin (F-actin). By electron microscopy, the structure of zonula adherens with an intercellular space of ∼10-20 nm was observed with strict parallelism of the adjoining cell membranes over distances of 1-20 μm, where ACAM and γ-actin are abundantly expressed. The formation of zonula adherens may increase the mechanical strength, inhibit the adipocyte hypertrophy, and improve the insulin sensitivity. PMID:26956488

  15. Nck2 Deficiency in Mice Results in Increased Adiposity Associated With Adipocyte Hypertrophy and Enhanced Adipogenesis.

    Science.gov (United States)

    Dusseault, Julie; Li, Bing; Haider, Nida; Goyette, Marie-Anne; Côté, Jean-François; Larose, Louise

    2016-09-01

    Obesity results from an excessive expansion of white adipose tissue (WAT) from hypertrophy of preexisting adipocytes and enhancement of precursor differentiation into mature adipocytes. We report that Nck2-deficient mice display progressive increased adiposity associated with adipocyte hypertrophy. A negative relationship between the expression of Nck2 and WAT expansion was recapitulated in humans such that reduced Nck2 protein and mRNA levels in human visceral WAT significantly correlate with the degree of obesity. Accordingly, Nck2 deficiency promotes an adipogenic program that not only enhances adipocyte differentiation and lipid droplet formation but also results in dysfunctional elevated lipogenesis and lipolysis activities in mouse WAT as well as in stromal vascular fraction and 3T3-L1 preadipocytes. We provide strong evidence to support that through a mechanism involving primed PERK activation and signaling, Nck2 deficiency in adipocyte precursors is associated with enhanced adipogenesis in vitro and adiposity in vivo. Finally, in agreement with elevated circulating lipids, Nck2-deficient mice develop glucose intolerance, insulin resistance, and hepatic steatosis. Taken together, these findings reveal that Nck2 is a novel regulator of adiposity and suggest that Nck2 is important in limiting WAT expansion and dysfunction in mice and humans. PMID:27325288

  16. 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.

  17. 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.

  18. 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.

  19. Generation and Identification of Monoclonal Antibody Against Porcine Adipocyte Plasma Membrane Proteins

    Institute of Scientific and Technical Information of China (English)

    CAO Jin-ling; CHEN Jian-jie; WANG Zhi-rui; WANG Jun-dong

    2007-01-01

    Production of monoclonal antibody against porcine adipocyte plasma membrane proteins to explore a new way of controlling body fat deposition and improving carcass quality is discussed in this article. Membrane proteins of pig adipocyte plasma membrane proteins were extracted with the help of sucrose density gradient centrifugation, and two kinds of proteins were obtained. The monoclonal antibody (designated 3B2 and 3F3) of IgGl and IgG2b subclass against adipocyte membrane proteins were produced by immunization, with adipocyte membrane proteins as an antigen, and its titer was 1:105 detected by enzyme-linked immunoadsorbent assay (ELISA). The cell strains were identified by analyzing the number of chromosomes, the heat stability, the acid and alkali, the types and subtypes of immnoglobulin, and its peculiarities and affinities. Through identification, the chromosome number of hybridoma cell strains was from 80 to 100 and the strains formed good hybridomas colonies. The strains' affinity constants were 4.63×109 and 3.75×109 (mol L-1)-1, respectively. At the same time, the McAb secreted was stable to environmental factors, such as, temperature, acid, alkali and so on. The monoclonal antibodies had been obtained and their specificity to porcine adipocyte plasma membrane proteins had been identified.

  20. Consequence of Menin Deficiency in Mouse Adipocytes Derived by In Vitro Differentiation

    Directory of Open Access Journals (Sweden)

    Vaishali I. Parekh

    2015-01-01

    Full Text Available Lipoma in patients with the multiple endocrine neoplasia type 1 (MEN1 syndrome is a type of benign fat-cell tumor that has biallelic inactivation of MEN1 that encodes menin and could serve as a model to investigate normal and pathologic fat-cell (adipocyte proliferation and function. The role of menin and its target genes in adipocytes is not known. We used in vitro differentiation to derive matched normal and menin-deficient adipocytes from wild type (WT and menin-null (Men1-KO mouse embryonic stem cells (mESCs, respectively, or 3T3-L1 cells without or with menin knockdown to investigate cell size, lipid content, and gene expression changes. Adipocytes derived from Men1-KO mESCs or after menin knockdown in 3T3-L1 cells showed a 1.5–1.7-fold increase in fat-cell size. Global gene expression analysis of mESC-derived adipocytes showed that lack of menin downregulated the expression of many differentially methylated genes including the tumor suppressor long noncoding RNA Meg3 but upregulated gene expression from the prolactin gene family locus. Our results show that menin deficiency leads to fat-cell hypertrophy and provide model systems that could be used to study the regulation of fat-cell size.

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

    Directory of Open Access Journals (Sweden)

    Akiko Eguchi

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

  2. 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.

  3. 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.

  4. 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.

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

    International Nuclear Information System (INIS)

    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

  6. Suppression of Lipid Accumulation by Indole-3-Carbinol Is Associated with Increased Expression of the Aryl Hydrocarbon Receptor and CYP1B1 Proteins in Adipocytes and with Decreased Adipocyte-Stimulated Endothelial Tube Formation

    Science.gov (United States)

    Wang, Mei-Lin; Lin, Shyh-Hsiang; Hou, Yuan-Yu; Chen, Yue-Hwa

    2016-01-01

    This study investigated the effects of indole-3-carbinol (I3C) on adipogenesis- and angiogenesis-associated factors in mature adipocytes. The cross-talk between mature adipocytes and endothelial cells (ECs) was also explored by cultivating ECs in a conditioned medium (CM) by using I3C-treated adipocytes. The results revealed that I3C significantly inhibited triglyceride accumulation in mature adipocytes in association with significantly increased expression of AhR and CYP1B1 proteins as well as slightly decreased nuclear factor erythroid-derived factor 2–related factor 2, hormone-sensitive lipase, and glycerol-3-phosphate dehydrogenase expression by mature adipocytes. Furthermore, I3C inhibited CM-stimulated endothelial tube formation, which was accompanied by the modulated secretion of angiogenic factors in adipocytes, including vascular endothelial growth factor, interleukin-6, matrix metalloproteinases, and nitric oxide. In conclusion, I3C reduced lipid droplet accumulation in adipocytes and suppressed adipocyte-stimulated angiogenesis in ECs, suggesting that I3C is a potential therapeutic agent for treating obesity and obesity-associated disorders. PMID:27527145

  7. Cyclin-dependent Kinase Inhibitor, p21WAF1/CIP1, Is Involved in Adipocyte Differentiation and Hypertrophy, Linking to Obesity, and Insulin Resistance*S⃞

    OpenAIRE

    Inoue, Noriyuki; Yahagi, Naoya; Yamamoto, Takashi; Ishikawa, Mayumi; Watanabe, Kazuhisa; Matsuzaka, Takashi; Nakagawa, Yoshimi; Takeuchi, Yoshinori; Kobayashi, Kazuto; Takahashi, Akimitsu; Suzuki, Hiroaki; Hasty, Alyssa H.; Toyoshima, Hideo; Yamada, Nobuhiro; Shimano, Hitoshi

    2008-01-01

    Both adipocyte hyperplasia and hypertrophy are determinant factors for adipocyte differentiation during the development of obesity. p21WAF1/CIP1, a cyclin-dependent kinase inhibitor, is induced during adipocyte differentiation; however, its precise contribution to this process is unknown. Using both in vitro and in vivo systems, we show that p21 is crucial for maintaining adipocyte hypertrophy and obesity-induced insulin resistance. The absence of p21 in 3T3-L1 fibroblasts ...

  8. BMP signaling pathway is required for commitment of C3H10T1/2 pluripotent stem cells to the adipocyte lineage

    OpenAIRE

    Huang, Haiyan; Song, Tan-Jing; Li, Xi; Hu, Lingling; He, Qun; Liu, Mei; Lane, M. Daniel; Tang, Qi-Qun

    2009-01-01

    Obesity is accompanied by an increase in both adipocyte number and size. The increase in adipocyte number is the result of recruitment to the adipocyte lineage of pluripotent stem cells present in the vascular stroma of adipose tissue. These pluripotent cells have the potential to undergo commitment and then differentiate into adipocytes, as well as myocytes, osteocytes, and chondrocytes. In this article, we show that both bone morphogenetic protein (BMP)2 and BMP4 can induce commitment of C3...

  9. Long-term effect of insulin on glucose transport and insulin binding in cultured adipocytes from normal and obese humans with and without non-insulin-dependent diabetes.

    OpenAIRE

    Sinha, M K; Taylor, L G; Pories, W J; Flickinger, E G; Meelheim, D; Atkinson, S.; Sehgal, N S; Caro, J F

    1987-01-01

    We have tested the hypothesis that in vitro exposure of insulin-resistant adipocytes with insulin results in improved insulin action. A primary culture system of adipocytes from obese subjects with or without non-insulin-dependent diabetes mellitus (NIDDM) and nonobese control subjects has been developed. The adipocytes when cultured in serum-free medium do not lose their original characteristics in regard to insulin binding and glucose transport. The adipocytes from three groups were incubat...

  10. Effect of repeated US stimulation on adiponectin secretion by adipocytes of obese human subjects

    Science.gov (United States)

    Fujii, Yasutomo; Taniguchi, Nobuyuki; Satoh, Masaaki; Irie, Takasuke; Itoh, Kouichi

    2006-05-01

    To clarify the effect of the repeated sonication on the adiponectin secretion by adipocytes obtained from obese subjects. Using 1-MHz continuous-wave ultrasound at an intensity of 0.50 or 2.1 W/cm2, we sonicated culture flasks of subcutaneous adipocytes obtained from obese human subjects, in a series of 3 sessions of US stimulation applied for a daily total of 15 min. For the measurement of adiponectin secretion, 50 μl of the culture medium was collected from each flask every 24 h after the 1st stimulation. Quantification of adiponectin protein levels in cell culture supernatants was performed with a commercially available ELISA kit recommended by the manufacturer. The adiponectin concentrations in the culture medium of the US stimulation groups rose significantly (padiponectin secretion in obese human adipocytes.

  11. 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.

  12. Dexamethasone in osteogenic medium strongly induces adipocyte differentiation of mouse bone marrow stromal cells and increases osteoblast differentiation

    NARCIS (Netherlands)

    O. Ghali (Olfa); O. Broux (Odile); G. Falgayrac (Guillaume); N. Haren (Nathalie); J.P.T.M. van Leeuwen (Hans); G. Penel (Guillaume); P. Hardouin (Pierre); C. Chauveau (Christophe)

    2015-01-01

    textabstractBackground: Osteoblasts and adipocytes share a common mesenchymal stem cell origin. Therefore, it has been suggested that the accumulation of marrow adipocytes observed in bone loss is caused by a shift in the commitment of mesenchymal stem cells from the osteogenic pathway to the adipog

  13. Dexamethasone in osteogenic medium strongly induces adipocyte differentiation of mouse bone marrow stromal cells and increases osteoblast differentiation

    NARCIS (Netherlands)

    O. Ghali (Olfa); O. Broux (Odile); G. Falgayrac (Guillaume); N. Haren (Nathalie); J.P.T.M. van Leeuwen (Hans); G. Penel (Guillaume); P. Hardouin (Pierre); C. Chauveau (Christophe)

    2015-01-01

    textabstractBACKGROUND: Osteoblasts and adipocytes share a common mesenchymal stem cell origin. Therefore, it has been suggested that the accumulation of marrow adipocytes observed in bone loss is caused by a shift in the commitment of mesenchymal stem cells from the osteogenic pathway to the adipog

  14. 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

    microsomal triglyceride transfer protein (MTP), 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...

  15. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Positive regulation by GABA(BR1 subunit of leptin expression through gene transactivation in adipocytes.

    Directory of Open Access Journals (Sweden)

    Yukari Nakamura

    Full Text Available BACKGROUND: The view that γ-aminobutyric acid (GABA plays a functional role in non-neuronal tissues, in addition to an inhibitory neurotransmitter role in the mammalian central nervous system, is prevailing, while little attention has been paid to GABAergic signaling machineries expressed by adipocytes to date. In this study, we attempted to demonstrate the possible functional expression of GABAergic signaling machineries by adipocytes. METHODOLOGY/PRINCIPAL FINDINGS: GABA(B receptor 1 (GABA(BR1 subunit was constitutively expressed by mouse embryonic fibroblasts differentiated into adipocytes and adipocytic 3T3-L1 cells in culture, as well as mouse white adipose tissue, with no responsiveness to GABA(BR ligands. However, no prominent expression was seen with mRNA for GABA(BR2 subunit required for heteromeric orchestration of the functional GABA(BR by any adipocytic cells and tissues. Leptin mRNA expression was significantly and selectively decreased in adipose tissue and embryonic fibroblasts, along with drastically reduced plasma leptin levels, in GABA(BR1-null mice than in wild-type mice. Knockdown by siRNA of GABA(BR1 subunit led to significant decreases in leptin promoter activity and leptin mRNA levels in 3T3-L1 cells. CONCLUSIONS/SIGNIFICANCE: Our results indicate that GABA(BR1 subunit is constitutively expressed by adipocytes to primarily regulate leptin expression at the transcriptional level through a mechanism not relevant to the function as a partner of heterodimeric assembly to the functional GABA(BR.

  18. Betaine reduces the expression of inflammatory adipokines caused by hypoxia in human adipocytes.

    Science.gov (United States)

    Olli, K; Lahtinen, S; Rautonen, N; Tiihonen, K

    2013-01-14

    Obesity is characterised by a state of chronic low-grade inflammation and the elevated circulating and tissue levels of inflammatory markers, including inflammation-related adipokines, released from white adipose tissue. The expression and release of these adipokines generally rises as the adipose tissue expands and hypoxic conditions start to develop within the tissue. Here, the effect of betaine, a trimethylglycine having a biological role as an osmolyte and a methyl donor, on the expression of inflammation-related markers was tested in human adipocytes under hypoxia. Differentiated adipocytes were cultivated under low (1 %) oxygen tension for 8-20 h. The expression of different adipokines, including IL-6, leptin, PPARγ, TNF-α and adiponectin, was measured by quantitative PCR by determining the relative mRNA level from the adipocytes. Hypoxia, in general, led to a decrease in the expression of PPARγ mRNA in human adipocytes, whereas the expression levels of leptin and IL-6 mRNA were substantially increased by hypoxia. The cultivation of adipocytes under hypoxia also led to a reduction in the expression of TNF-α mRNA. The results showed that hypoxia increased the relative quantification of leptin gene transcription, and that betaine (250 μmol/l) reduced this effect, caused by low oxygen conditions. Under hypoxia, betaine also reduced the mRNA level of the pro-inflammatory markers IL-6 and TNF-α. These results demonstrate that the extensive changes in the expression of inflammation-related adipokines in human adipocytes caused by hypoxia can be diminished by the presence of physiologically relevant concentrations of betaine. PMID:22424556

  19. 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.

  20. 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:

  1. Increased extracellular and intracellular Ca2+ lead to adipocyte accumulation in bone marrow stromal cells by different mechanisms

    International Nuclear Information System (INIS)

    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 Ca2+ ([Ca2+]o and [Ca2+]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 [Ca2+]o and high [Ca2+]i enhanced adipocyte accumulation, which suggested that increases in [Ca2+]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 [Ca2+]o and high [Ca2+]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 [Ca2+]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 [Ca2+]o (addition of CaCl2) leads to increases in [Ca2+]i. Flow cytometric methods revealed that high [Ca2+]o suppressed the phosphorylation of ERK independently of intracellular Ca2+. The inhibition of ERK by U0126 and PD0325901 enhanced the differentiation of BMSCs into adipocytes. These data suggest that increased extracellular Ca2+ provides the differentiation of BMSCs into adipocytes by the suppression of ERK activity independently of increased intracellular Ca2+, which results in BMSC proliferation. - Highlights: • Both high [Ca2+]o and high [Ca2+]i enhanced adipocyte accumulation in BMSCs. • High [Ca2+]i enhanced the proliferation of BMSCs but not adipocyte differentiation

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

    International Nuclear Information System (INIS)

    Glucose metabolism in adipocytes from 6 week old lean and obese Zucker rats were sensitive to direct and chronic treatment with insulin and triidothyronine (T3). Insulin had a large stimulatory effect on glucose metabolism in acutely isolated adipocytes. This effect was greater in the lean than in the obese. Fatty acid, CO2, and glycerol-glyceride formation from radiolabeled glucose was elevated in the obese over the leans. Pretreatment of isolated adipocytes with pharmacological concentrations of T3 for 30 minutes prior to the measurement of glucose metabolism had a greater effect on lean than obese adipocytes. The presence of insulin was required to observe the acute effects of T3. A 2-hour exposure to physiological levels of T3 in the presence of insulin in both lean and obese adipocytes decreased lipogenesis. In the absence of insulin, a 2 hour pretreatment with physiological levels of T3 in tissue from a euthyroid animal produced increased lipogenesis

  3. 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.

  4. Roles for miRNA-378/378* in adipocyte gene expression and lipogenesis

    OpenAIRE

    Gerin, Isabelle; Bommer, Guido T.; McCoin, Colin S.; Sousa, Kyle M.; Krishnan, Venkatesh; MacDougald, Ormond A.

    2010-01-01

    In this study, we explored the roles of microRNAs in adipocyte differentiation and metabolism. We first knocked down Argonaute2 (Ago2), a key enzyme in the processing of micro-RNAs (miRNAs), to investigate a potential role for miRNAs in adipocyte differentiation and/or metabolism. Although we did not observe dramatic differences in adipogenesis between Ago2 knock-down and control 3T3-L1 cells, incorporation of [14C]glucose or acetate into triacylglycerol, and steady-state levels of triacyglyc...

  5. 17β-Estradiol inhibition of PPARγ-induced adipogenesis and adipocyte-specific gene expression

    OpenAIRE

    Jeong, Sunhyo; Yoon, Michung

    2011-01-01

    Aim: To investigate the molecular interaction of peroxisome proliferator-activated receptor γ (PPARγ) with 17β-estradiol (E) in the regulation of adipogenesis. Methods: Female ovariectomized (OVX) mice and differentiated 3T3-L1 adipocytes were treated with combinations of the PPARγ agonist troglitazone or E, and the variables and determinants of adipogenesis were measured using in vivo and in vitro approaches. Results: Troglitazone (250 mg·kg−1·d−1 for 13 weeks) decreased the size of adipocyt...

  6. Studying Lipolysis in Adipocytes by Combining siRNA Knockdown and Adenovirus-Mediated Overexpression Approaches

    OpenAIRE

    Zhang, Xiaodong; Heckmann, Bradlee L; Liu, Jun

    2013-01-01

    3T3-L1 adipocytes are widely used as a model system for studying hormone-stimulated lipolysis. However, these cells were limited in their utility for gain- and loss-of-function studies due to the low efficiency of their transfection with plasmid DNA or small interfering RNA (siRNA) oligos. In this chapter, we provide a review of two methods established for manipulation of protein expression in differentiated mature adipocytes. The use of electroporation allows a high-efficiency delivery of si...

  7. 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

    cells was reported to inhibit adipocyte differentiation. Here we show that efficient and regulated processing of Pref-1 occurs in 3T3-L1 preadipocytes releasing most of the extracellular domain as a 50-kDa heterogeneous protein, previously isolated and characterized as FA1. Unexpectedly, we found that...... forced expression of the soluble form, FA1, or full-length Pref-1 did not inhibit adipocyte differentiation of 3T3-L1 cells when differentiation was induced by standard treatment with methylisobutylxanthine, dexamethasone, and high concentrations of insulin. However, forced expression of either form of...

  8. Increased insulin sensitivity and responsiveness of glucose metabolism in adipocytes from female versus male rats.

    OpenAIRE

    Guerre-Millo, M.; Leturque, A.; Girard, J.; Lavau, M

    1985-01-01

    This study was undertaken to examine whether there were sex-associated differences in the action of insulin on glucose metabolism in adipocytes. Insulin binding and the dose-response curves for glucose transport (assessed by measuring the cell-associated radioactivity after 15-s incubation with 50 microM [6-14C]glucose) and [U-14C]glucose (5 mM) metabolism into CO2 and lipids were compared in retroperitoneal adipocytes from age-matched (84 d) male and female rats. In addition, the activity of...

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

    OpenAIRE

    Sinclair Andrew J; Manickam Elizabeth; Cameron-Smith David

    2010-01-01

    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) ...

  10. 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...

  11. 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......Cold adaptation elicits a paradoxical simultaneous induction of fatty acid synthesis and beta-oxidation in brown adipose tissue. We show here that cold exposure coordinately induced liver X receptor alpha (LXRalpha), adipocyte determination and differentiation-dependent factor 1 (ADD1)/sterol...... as a regulator of PGC1alpha expression in brown adipose tissue....

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

    International Nuclear Information System (INIS)

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

  13. 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.

  14. Ox-LDL induces ER stress and promotes the adipokines secretion in 3T3-L1 adipocytes.

    Directory of Open Access Journals (Sweden)

    Yaqin Chen

    Full Text Available Adipocytes behave as a rich source of adipokines, which may be the link between obesity and its complications. Endoplasmic reticulum (ER stress in adipocytes can modulate adipokines secretion. The aim of this study is to evaluate the effect of oxidized low density lipoprotein (ox-LDL treatment on ER stress and adipokines secretion in differentiated adipocytes. 3T3-L1 pre-adipocytes were cultured and differentiated into mature adipocytes in vitro. Differentiated adipocytes were incubated with various concentrations of ox-LDL (0-100 µg/ml for 48 hours; 50 µg/ml ox-LDL for various times (0-48 hours with or without tauroursodeoxycholic acid (TUDCA (0-400 µM pre-treatment. The protein expressions of ER stress markers, glucose regulated protein 78(GRP78 and CCAAT/enhancer binding protein [C/EBP] homologous protein (CHOP in adipocytes were detected by Western blot. The mRNA expressions of visfatin and resistin were measured by real-time PCR and the protein release of visfatin and resistin in supernatant were determined by ELISA. Treatment with ox-LDL could increase the cholesterol concentration in adipocytes. Ox-LDL induced the expressions of GRP78 and CHOP protein in adipocytes and promoted visfatin and resistin secretion in culture medium in dose and time-dependent manner. TUDCA could attenuate the effect of ox-LDL on GRP78 and CHOP expressions and reduce visfatin and resistin at mRNA and protein level in dose-dependent manner. In conclusion, ox-LDL promoted the expression and secretion of visfatin and resistin through its activation of ER stress, which may be related to the increase of cholesterol load in adipocytes.

  15. 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

  16. 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.

  17. 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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    epididymal, inguinal, and brown adipose tissues. While these PPARγ binding profiles are overall similar, there are clear depot-selective binding sites. Most PPARγ binding sites previously mapped in 3T3-L1 adipocytes can also be detected in primary adipocytes, but there are a large number of PPARγ binding...... how binding patterns of PPARγ differ between brown and white adipocytes and among different types of white adipocytes. Here we have employed chromatin immunoprecipitation combined with deep sequencing to map and compare PPARγ binding in in vitro differentiated primary mouse adipocytes isolated from...

  19. 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

    Science.gov (United States)

    Abdul-Rahman, Omar; Kristóf, Endre; Doan-Xuan, Quang-Minh; Vida, András; Nagy, Lilla; Horváth, Ambrus; Simon, József; Maros, Tamás; Szentkirályi, István; Palotás, Lehel; Debreceni, Tamás; Csizmadia, Péter; Szerafin, Tamás; Fodor, Tamás; Szántó, Magdolna; Tóth, Attila; Kiss, Borbála; Bacsó, Zsolt; Bai, Péter

    2016-01-01

    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 the same when

  20. Trans-10, cis-12 conjugated linoleic acid decreases de novo lipid synthesis in human adipocytes

    DEFF Research Database (Denmark)

    Obsen, Thomas; Faergeman, Nils J; Chung, Soonkyu;

    2012-01-01

    Conjugated linoleic acid (CLA) reduces adiposity in vivo. However, mechanisms mediating these changes are unclear. Therefore, we treated cultures of human adipocytes with trans-10, cis-12 (10,12) CLA, cis-9, trans-11 (9,11) CLA or other trans fatty acids (FA), and measured indices of lipid...

  1. Increased Adipocyte Area in Injured Muscle With Aging and Impaired Remodeling in Female Mice.

    Science.gov (United States)

    Fearing, Caitlin M; Melton, David W; Lei, Xiufen; Hancock, Heather; Wang, Hanzhou; Sarwar, Zaheer U; Porter, Laurel; McHale, Matthew; McManus, Linda M; Shireman, Paula K

    2016-08-01

    We demonstrated that young male and female mice similarly regenerated injured skeletal muscle; however, female mice transiently increased adipocyte area within regenerated muscle in a sex hormone-dependent manner. We extended these observations to investigate the effect of aging and sex on sarcopenia and muscle regeneration. Cardiotoxin injury to the tibialis anterior muscle of young, middle, and old-aged C57Bl/6J male and female mice was used to measure regenerated myofiber cross-sectional area (CSA), adipocyte area, residual necrosis, and inflammatory cell recruitment. Baseline (uninjured) myofiber CSA was decreased in old mice of both sexes compared to young and middle-aged mice. Regenerated CSA was similar in male mice in all age groups until baseline CSA was attained but decreased in middle and old age female mice compared to young females. Furthermore, adipocyte area within regenerated muscle was transiently increased in young females compared to young males and these sex-dependent increases persisted in middle and old age female mice and were associated with increased Pparg Young female mice had more pro-inflammatory monocytes/macrophages in regenerating muscle than young male mice and increased Sca-1(+)CD45(-)cells. In conclusion, sex and age influence pro-inflammatory cell recruitment, muscle regeneration, and adipocyte area following skeletal muscle injury. PMID:26273023

  2. Adipocyte morphometric evaluation and angiogenesis in the omentum transposed to the breast: a preliminary study

    Directory of Open Access Journals (Sweden)

    Sirlei Santos Costa

    2011-01-01

    Full Text Available OBJECTIVE: The purpose of this study was to describe the probable mechanism of the volume increase of laparoscopically harvested omentum flaps used to treat breast deformities. METHODS: A histological analysis of omentum samples was performed to study the volume increase of laparoscopically harvested omentum flaps. Samples were harvested immediately after the transposition of the omentum from the abdominal cavity to the breast region and during the second surgical procedure for breast symmetrization of eight patients submitted to the transposition of the omentum flap. Changes in the morphometric measurements of the adipocytes (perimeter, diameter, and area, microvascular density (as measured by the CD31 endothelial marker, and immunohistochemical expression of VEGF were documented. RESULTS: The increases in adipocyte size and microvascular density were statistically significant (P < 0.012. The expression levels of VEGF were lower in the second set of samples when compared to the first set, but the differences were not statistically significant (P < 0.093. CONCLUSION: These results demonstrate an increase in cellular volume as measured by adipocyte perimeter, diameter, and area. Moreover, the increase in the number of vessels in the second set of samples suggests that neoangiogenesis was stimulated by the initial increase in VEGF expression levels observed in the first set of samples. The increase in VEGF expression in the flap may have been caused by adipocyte hypertrophy resulting from neoangiogenesis.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-06-15

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    O'Farrelly, Cliona

    2010-01-01

    12 Hide Figures Abstract Introduction Methods Results Discussion Author Contributions References Reader Comments (0) Figures Abstract 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 healt...

  6. 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.

  7. Modulation of activity of the adipocyte aquaglyceroporin channel by plant extracts.

    Science.gov (United States)

    Cals-Grierson, M-M

    2007-02-01

    The plasma membrane protein, aquaglyceroporin-7 (AQP7) is exclusively expressed in adipocytes and appears to be a channel for glycerol entry and exit. It is possible that by facilitating the opening of these channels, the loss of intracellular glycerol could be encouraged and thus reduce the size of the lipid reservoir. Human preadipocytes and mouse 3T3-L1 preadipocytes were induced to develop an adipocytic phenotype by culture in a semi-defined medium. After 7 days, the expression of AQP7 message had increased by 37-fold, a level which could be further up-regulated by troglitazone or retinoic acid or down-regulated by insulin. The mature adipocytes also expressed immunoreactive aquaporin (AQP) channel protein as assessed by immunocytochemistry and Western blot. The addition of adrenaline to the culture medium stimulated the release of glycerol (blockable by HgCl(2)). Plant extracts, with potential anti-cellulite properties, were tested for their effect on glycerol elimination. These included wild yam root (Dioscorea opposita), cocoa bean (Theobroma cacao), horse chestnut tree (Aesculus hippocastanum) seed and bark and tomato (Solanum lycopersicum). Of these, D. opposita appeared to induce a dose-dependent glycerol release. The results show that our assay can help to identify modulators of AQP7 channel expression and activation in adipocytes. PMID:18489306

  8. 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.

  9. 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

    -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...

  10. Board Sponsored Invited Review: The biology and regulation of preadipocytes and adipocytes in meat animals

    Science.gov (United States)

    The quality and value of the carcass in domestic meat animals is reflected in its protein and fat content. Preadipocytes and adipocytes are important in establishing the overall fatness of a carcass, as well as being the main contributors to the marbling component needed for consumer preference of ...

  11. 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.

  12. 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...

  13. 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...

  14. 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

  15. 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.

  16. [Study of the spatial repartition of adipocytes with a texture analyser (author's transl)].

    Science.gov (United States)

    Digabel, H; Trebuchet, C

    1979-04-01

    A method is given for quantifying the medullary weakness from biopsies of the iliac bone. It consists in calculating the variogram of adipocyte area proportion in a moving window of 70 micron x 70 micron moving 2 mm along the thin section. A numerical application is provided. PMID:379760

  17. 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...

  18. 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...

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

    DEFF Research Database (Denmark)

    Gormand, Amélie; Henriksson, Emma; Ström, Kristoffer;

    2011-01-01

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

  20. 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.

  1. 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...

  2. 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...

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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...

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

    International Nuclear Information System (INIS)

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

  9. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-25

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

  11. In preeclampsia, maternal third trimester subcutaneous adipocyte lipolysis is more resistant to suppression by insulin than in healthy pregnancy.

    Science.gov (United States)

    Huda, Shahzya S; Forrest, Rachel; Paterson, Nicole; Jordan, Fiona; Sattar, Naveed; Freeman, Dilys J

    2014-05-01

    Obesity increases preeclampsia risk, and maternal dyslipidemia may result from exaggerated adipocyte lipolysis. We compared adipocyte function in preeclampsia with healthy pregnancy to establish whether there is increased lipolysis. Subcutaneous and visceral adipose tissue biopsies were collected at caesarean section from healthy (n=31) and preeclampsia (n=13) mothers. Lipolysis in response to isoproterenol (200 nmol/L) and insulin (10 nmol/L) was assessed. In healthy pregnancy, subcutaneous adipocytes had higher diameter than visceral adipocytes (PADRB3, LPL, and leptin and higher insulin receptor messenger RNA expression than subcutaneous adipose tissue. There was no difference in subcutaneous adipocyte lipolysis rates between preeclampsia and healthy controls, but subcutaneous adipocytes had lower sensitivity to insulin in preeclampsia, independent of cell diameter (P<0.05). In preeclampsia, visceral adipose tissue had higher LPL messenger RNA expression than subcutaneous. In conclusion, in healthy pregnancy, the larger total mass of subcutaneous adipose tissue may release more fatty acids into the circulation than visceral adipose tissue. Reduced insulin suppression of subcutaneous adipocyte lipolysis may increase the burden of plasma fatty acids that the mother has to process in preeclampsia. PMID:24591340

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

    Science.gov (United States)

    Shan, Tizhong; Liu, Weiyi; Kuang, Shihuan

    2013-01-01

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

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

    International Nuclear Information System (INIS)

    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

  14. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-14

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

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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

  18. 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.

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

    Science.gov (United States)

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

    2015-01-01

    This work investigated how cold stress induces the appearance of brown adipocytes (BAs) in brown and white adipose tissues (WATs) of adult mice. In interscapular brown adipose tissue (iBAT), cold exposure increased proliferation of endothelial cells and interstitial cells expressing platelet-derived growth factor receptor, α polypeptide (PDGFRα) by 3- to 4-fold. Surprisingly, brown adipogenesis and angiogenesis were largely restricted to the dorsal edge of iBAT. Although cold stress did not increase proliferation in inguinal white adipose tissue (ingWAT), the percentage of BAs, defined as multilocular adipocytes that express uncoupling protein 1, rose from undetectable to 30% of total adipocytes. To trace the origins of cold-induced BAs, we genetically tagged PDGFRα(+) cells and adipocytes prior to cold exposure, using Pdgfra-Cre recombinase estrogen receptor T2 fusion protein (CreER(T2)) and adiponectin-CreER(T2), respectively. In iBAT, cold stress triggered the proliferation and differentiation of PDGFRα(+) cells into BAs. In contrast, all newly observed BAs in ingWAT (5207 out of 5207) were derived from unilocular adipocytes tagged by adiponectin-CreER(T2)-mediated recombination. Surgical denervation of iBAT reduced cold-induced brown adipogenesis by >85%, whereas infusion of norepinephrine (NE) mimicked the effects of cold in warm-adapted mice. NE-induced de novo brown adipogenesis in iBAT was eliminated in mice lacking β1-adrenergic receptors. These observations identify a novel tissue niche for brown adipogenesis in iBAT and further define depot-specific mechanisms of BA recruitment. PMID:25392270

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

    Directory of Open Access Journals (Sweden)

    Kumaratilake Jaliya S

    2008-04-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  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. 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...... result of enhanced adipogenesis and decreased osteoblastogenesis from the MSCs. Thus, cultures of MSCs were established from young donors (age 18-42, n = 34), elderly healthy donors (age 66-78, n = 20), and patients with OP (age 58-76, n = 15). Cells were cultured for 2 weeks in an adipogenic medium...... phosphatase (AP+), and adipocytic colonies containing adipocytes (Ad+) were quantitated. In addition, steady state mRNA levels of gene markers of adipocytic and osteoblastic phenotypes were determined using reverse-transcriptase polymerase chain reaction (RT-PCR). The adipogenic and osteogenic media induced...

  4. 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...

  5. Angiotensin II type 2 receptor promotes adipocyte differentiation and restores adipocyte size in high-fat/high-fructose diet-induced insulin resistance in rats

    OpenAIRE

    Shum, Michaël; Pinard, Sandra; Guimond, Marie-Odile; Labbé, Sébastien M.; Roberge, Claude; Baillargeon, Jean-Patrice; Langlois, Marie-France; Alterman, Mathias; Wallinder, Charlotta; Hallberg, Anders; Carpentier, André C; Gallo-Payet, Nicole

    2012-01-01

    This study was aimed at establishing whether specific activation of angiotensin II (ANG II) type 2 receptor (AT2R) modulates adipocyte differentiation and function. In primary cultures of subcutaneous (SC) and retroperitoneal (RET) preadipocytes, both AT2R and AT1R were expressed at the mRNA and protein level. Cells were stimulated with ANG II or the AT2R agonist C21/M24, alone or in the presence of the AT1R antagonist losartan or the AT2R antagonist PD123,319. During differentiation, C21/M24...

  6. Adipocyte-Specific Protein Tyrosine Phosphatase 1B Deletion Increases Lipogenesis, Adipocyte Cell Size and is a Minor Regulator of Glucose Homeostasis

    OpenAIRE

    Carl Owen; Alicja Czopek; Abdelali Agouni; Louise Grant; Robert Judson; Lees, Emma K; George D Mcilroy; Olga Göransson; Andy Welch; Bence, Kendra K.; Kahn, Barbara B.; Neel, Benjamin G.; Nimesh Mody; Mirela Delibegović

    2012-01-01

    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...

  7. Fenofibrate inhibits adipocyte hypertrophy and insulin resistance by activating adipose PPARα in high fat diet-induced obese mice

    OpenAIRE

    Jeong, Sunhyo; Yoon, Michung

    2009-01-01

    Peroxisome proliferator-activated receptor α (PPARα) activation in rodents is thought to improve insulin sensitivity by decreasing ectopic lipids in non-adipose tissues. Fenofibrate, a lipid-modifying agent that acts as a PPARα agonist, may prevent adipocyte hypertrophy and insulin resistance by increasing intracellular lipolysis from adipose tissue. Consistent with this hypothesis, fenofibrate decreased visceral fat mass and adipocyte size in high fat diet-fed obese mice, and concomitantly i...

  8. Influence of anatomic site and age on the replication and differentiation of rat adipocyte precursors in culture.

    OpenAIRE

    Djian, P.; Roncari, A K; Hollenberg, C H

    1983-01-01

    Using a propagating cell culture system of adipocyte precursors from 70-400-g rats, we explored the possibility that regional variations in properties of adipose tissue may reflect site-specific characteristics intrinsic to the cells, rather than extracellular influences. Initially, studies were made of the nature of the fibroblastlike cells from perirenal adipose tissue stroma. Using colony-forming techniques, it was shown that these cells were adipocyte precursors; each confluent colony tha...

  9. Fetal baboon sex specific outcomes in adipocyte differentiation at 0.9 gestation in response to moderate maternal nutrient reduction

    OpenAIRE

    Tchoukalova, Yourka D.; Krishnapuram, Rashmi; White, Ursula A.; Burk, David; Fang, Xiaobing; Nijland, Mark J.; Nathanielsz, Peter W.

    2013-01-01

    Objective To investigate in vitro adipocyte differentiation in baboon fetuses in response to reduced maternal nutrition. Design Cross-sectional comparison of adipocyte differentiation in normally grown fetuses and fetuses of pregnant baboons fed 70% control global diet from 30 days of pregnancy to term. Subjects Control (CTR) fetuses of ad libitum fed mothers (5 females and 5 males) and fetuses of mothers fed the 70% global diet eaten by CTR (MNR, 5 females and 5 males). The expression of gen...

  10. 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.

  11. Resistance to the antilipolytic effect of insulin in adipocytes of African-American compared to Caucasian postmenopausal women

    OpenAIRE

    Fried, Susan K.; Tittelbach, Thomas; Blumenthal, Jacob; Sreenivasan, Urmila; Robey, Linda; Yi, Jamie; Khan, Sumbul; Hollender, Courtney; Ryan, Alice S.; Goldberg, Andrew P.

    2010-01-01

    High fatty acid (FA) flux is associated with systemic insulin resistance, and African-American (AA) women tend to be more insulin resistant. We assessed possible depot and race difference in the antilipolytic effect of insulin in adipocytes isolated from abdominal (Abd) and gluteal (Glt) subcutaneous (sc) adipose tissue of overweight, postmenopausal AA and Caucasian (C) women. Percent body fat, fasting insulin, visceral adiposity, and adipocyte size was higher in AA women. Disinhibited lipoly...

  12. Cell Surface Orifices of Caveolae and Localization of Caveolin to the Necks of Caveolae in AdipocytesV⃞

    OpenAIRE

    Thorn, Hans; Stenkula, Karin G.; Karlsson, Margareta; Örtegren, Unn; Nystrom, Fredrik H; Gustavsson, Johanna; Strålfors, Peter

    2003-01-01

    Caveolae are noncoated invaginations of the plasma membrane that form in the presence of the protein caveolin. Caveolae are found in most cells, but are especially abundant in adipocytes. By high-resolution electron microscopy of plasma membrane sheets the detailed structure of individual caveolae of primary rat adipocytes was examined. Caveolin-1 and -2 binding was restricted to the membrane proximal region, such as the ducts or necks attaching the caveolar bulb to the membrane. This was con...

  13. Region-specific variation in the properties of skeletal adipocytes reveals regulated and constitutive marrow adipose tissues

    OpenAIRE

    Erica L. Scheller; Doucette, Casey R.; Learman, Brian S.; Cawthorn, William P; Khandaker, Shaima; Schell, Benjamin; Wu, Brent; Ding, Shi-Ying; Bredella, Miriam A.; Fazeli, Pouneh K.; Khoury, Basma; Jepsen, Karl J.; Pilch, Paul F.; Klibanski, Anne; ROSEN, CLIFFORD J

    2015-01-01

    Marrow adipose tissue (MAT) accumulates in diverse clinical conditions but remains poorly understood. Here we show region-specific variation in MAT adipocyte development, regulation, size, lipid composition, gene expression, and genetic determinants. Early MAT formation in mice is conserved, while later development is strain dependent. Proximal, but not distal, MAT is lost with 21-day cold exposure. Rat MAT adipocytes from distal sites have an increased proportion of monounsaturated fatty aci...

  14. In preeclampsia, maternal third trimester subcutaneous adipocyte lipolysis is more resistant to suppression by insulin than in healthy pregnancy

    OpenAIRE

    Huda, Shahzya S; Forrest, Rachel; Paterson, Nicole; Jordan, Fiona; Sattar, Naveed; Freeman, Dilys J.

    2014-01-01

    Obesity increases preeclampsia risk, and maternal dyslipidemia may result from exaggerated adipocyte lipolysis. We compared adipocyte function in preeclampsia with healthy pregnancy to establish whether there is increased lipolysis. Subcutaneous and visceral adipose tissue biopsies were collected at caesarean section from healthy (n=31) and preeclampsia (n=13) mothers. Lipolysis in response to isoproterenol (200 nmol/L) and insulin (10 nmol/L) was assessed. In healthy pregnancy, subcutaneous ...

  15. 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.

  16. Proinflammatory cytokine production and insulin sensitivity regulated by overexpression of resistin in 3T3-L1 adipocytes

    Directory of Open Access Journals (Sweden)

    Garvey W Timothy

    2006-07-01

    Full Text Available Abstract Resistin is secreted from adipocytes, and high circulating levels have been associated with obesity and insulin resistance. To investigate whether resistin could exert autocrine effects in adipocytes, we expressed resistin gene in 3T3-L1 fibroblasts using a lentiviral vector, and selected several stably-transduced cell lines under blasticidin selection. We observed that 3T3-L1 adipocytes expressing resistin have a decreased gene expression for related transcriptional factors (CCAAT/enhancer binding protein α(C/EBPα , peroxisome proliferator-activated receptor gamma (PPARγ, and adipocyte lipid binding protein (ALBP/aP2 which is one of target genes for the PPARγ during adipocyte differentiation,. Overexpression of resistin increased the levels of three proinflammatory cytokines, tumor necrosis factor alpha (TNFα, interleukin 6 (IL-6 and monocyte chemoattractant protein-1 (MCP-1, which play important roles for insulin resistance, glucose and lipid metabolisms during adipogenesis. Furthermore, overexpressing resistin in adipocytes inhibits glucose transport 4 (GLUT4 activity and its gene expression, reducing insulin's ability for glucose uptake by 30 %. In conclusion, resistin overexpression in stably transduced 3T3-L1 cells resulted in: 1 Attenuation of programmed gene expression responsible for adipogenesis; 2 Increase in expression of proinflammatory cytokines; 3 Decrease in insulin responsiveness of the glucose transport system. These data suggest a new role for resistin as an autocrine/paracrine factor affecting inflammation and insulin sensitivity in adipose tissue.

  17. 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. PMID:18386066

  18. 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.

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

    Science.gov (United States)

    DiSilvestro, David J; Melgar-Bermudez, Emiliano; Yasmeen, Rumana; Fadda, Paolo; Lee, L James; Kalyanasundaram, Anuradha; Gilor, Chen L; Ziouzenkova, Ouliana

    2016-01-01

    The neuroendocrine effects of leptin on metabolism hold promise to be translated into a complementary therapy to traditional insulin therapy for diabetes and obesity. However, injections of leptin can provoke inflammation. We tested the effects of leptin, produced in the physiological adipocyte location, on metabolism in mouse models of genetic and dietary obesity. We generated 3T3-L1 adipocytes constitutively secreting leptin and encapsulated them in a poly-L-lysine membrane, which protects the cells from immune rejection. Ob/ob mice (OB) were injected with capsules containing no cells (empty, OB[Emp]), adipocytes (OB[3T3]), or adipocytes overexpressing leptin (OB[Lep]) into both visceral fat depots. Leptin was found in the plasma of OB[Lep], but not OB[Emp] and OB[3T3] mice at the end of treatment (72 days). The OB[Lep] and OB[3T3] mice have transiently suppressed appetite and weight loss compared to OB[Emp]. Only OB[Lep] mice have greater brown fat mass, metabolic rate, and reduced resistin plasma levels compared to OB[Emp]. Glucose tolerance was markedly better in OB[Lep] vs. OB[Emp] and OB[3T3] mice as well as in wild type mice with high-fat diet-induced obesity and insulin resistance treated with encapsulated leptin-producing adipocytes. Our proof-of-principle study provides evidence of long-term improvement of glucose tolerance with encapsulated adipocytes producing leptin. PMID:27055280

  20. 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.