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Sample records for adipocyte differentiation lipid

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

    SciTech Connect

    Lasrich, Dorothee; Bartelt, Alexander; Grewal, Thomas; Heeren, Joerg

    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.

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

    SciTech Connect

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

    2008-02-15

    There is a great demand for cell models to study human adipocyte function. Here we describe the adipogenic differentiation of a telomerase-immortalized human mesenchymal stem cell line (hMSC-Tert) that maintains numerous features of terminally differentiated adipocytes even after prolonged withdrawal of the peroxisome proliferator activated receptor {gamma} (PPAR{gamma}) 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 PPAR{gamma} 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 PPAR{gamma}-stimulated proteins with a role in lipid metabolism. We observed an increase of lipoprotein receptor (VLDLR, LRP1) and apolipoprotein E expression during differentiation. Despite this increased expression, the receptor-mediated endocytosis of lipoproteins was decreased in differentiated adipocytes, suggesting that these proteins may have an additional function in adipose tissue beyond lipoprotein uptake.

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

    PubMed

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

    2008-02-15

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

  4. Initial differences in lipid processing leading to pig-and beef-derived mature adipocyte differentiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Clonal cultures of pig-derived mature adipocytes are capable of dedifferentiating and forming proliferative-competent progeny cells in vitro. Initial lipid processing, is different to that observed in cultures of beef-derived adipocytes. Mature pig adipocytes extrude lipid before proliferation, wher...

  5. Polychlorinated biphenyl 153 in lipid medium modulates differentiation of human adipocytes.

    PubMed

    Mullerova, D; Pesta, M; Dvorakova, J; Cedikova, M; Kulda, V; Dvorak, P; Bouchalová, V; Kralickova, M; Babuska, V; Kuncova, J; Langmajerova, J; Muller, L

    2017-04-12

    Emerging evidence indicates that polychlorinated biphenyls (PCBs) are involved in the development of diabetes mellitus in the obese. The purpose of this study was to determine mechanisms by which PCB 153 (2,2´,4,4´,5,5´-hexachlorobiphenyl) could influence diet-induced obesity and insulin resistance during adipogenesis. Lineage of h-ADMSCs was differentiated either as control (differentiation medium only), or with lipid vehicle modelling high fat nutrition (NuTRIflex) or lipid free vehicle (dimethylsulfoxide) for 28 days with or without PCB 153 daily co-exposure (in three concentrations 0.1, 1, and 10 microM). Gene expression analyses were performed using RT-qPCR at days 4, 10, 21, 24, 28; protein levels Akt and phosphorylated Akt (Phospho-Akt) by Western blot at days 4, and 21. PCB 153 treatment of h-ADMSCs only in lipid vehicle was associated with down regulation of key master genes of adipogenesis: PPARgamma, SREBP-1, PPARGC1B, and PLIN2 during the whole process of differentiation; and with increased Akt and decreased Phospho-Akt protein level at day 21. We have shown that PCB 153, in concentration 0.1 microM, has a potential in lipid rich environment to modulate differentiation of adipocytes. Because European and U.S. adults have been exposed to PCB 153, this particular nutrient-toxicant interaction potentially impacts human obesity and insulin sensitivity.

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

    SciTech Connect

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

    2014-02-15

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

  7. Effects of lipid-related factors on adipocyte differentiation of bovine stromal-vascular cells in primary culture.

    PubMed

    Wu, P; Sato, K; Suzuta, F; Hikasa, Y; Kagota, K

    2000-09-01

    The effects of several factors related to lipids on bovine adipocyte differentiation were investigated in primary culture. Adipocyte differentiation was assessed by development of glycerol-3-phosphate dehydrogenase (GPDH) activity and morphological observation. Addition of triglyceride mixture (Intralipid), caprylic acid and very low-, low- and high-density lipoproteins (VLDL, LDL and HDL) stimulated bovine preadipocyte differentiation in serum-free condition. Especially, VLDL strongly increased both cell protein contents and GPDH activity, suggesting that it stimulated both proliferation and differentiation of bovine preadipocytes. Under Intralipid-induced condition, differentiation of preadipocytes from subcutaneous adipose tissues was more evident than those from omental adipose tissues. However, such depot difference was not observed in medium supplemented with indomethacin, which is a peroxisome proliferator-activated receptor (PPAR) gamma agonist. This suggests that the differentiation capacity of bovine preadipocytes was different between depots and such difference is dependent on the ability to utilize lipids as endogenous PPARgamma ligands. Therefore, lipid metabolites have the stimulatory effects on bovine adipocyte differentiation in vitro, and lipoproteins, especially VLDL, may play an important role in development of bovine adipose tissues in vivo.

  8. Interferon γ Attenuates Insulin Signaling, Lipid Storage, and Differentiation in Human Adipocytes via Activation of the JAK/STAT Pathway*

    PubMed Central

    McGillicuddy, Fiona C.; Chiquoine, Elise H.; Hinkle, Christine C.; Kim, Roy J.; Shah, Rachana; Roche, Helen M.; Smyth, Emer M.; Reilly, Muredach P.

    2009-01-01

    Recent reports demonstrate T-cell infiltration of adipose tissue in early obesity. We hypothesized that interferon (IFN) γ, a major T-cell inflammatory cytokine, would attenuate human adipocyte functions and sought to establish signaling mechanisms. Differentiated human adipocytes were treated with IFNγ ± pharmacological inhibitors prior to insulin stimulation. [3H]Glucose uptake and AKT phosphorylation were assessed as markers of insulin sensitivity. IFNγ induced sustained loss of insulin-stimulated glucose uptake in human adipocytes, coincident with reduced Akt phosphorylation and down-regulation of the insulin receptor, insulin receptor substrate-1, and GLUT4. Loss of adipocyte triglyceride storage was observed with IFNγ co-incident with reduced expression of peroxisome proliferator-activated receptor γ, adiponectin, perilipin, fatty acid synthase, and lipoprotein lipase. Treatment with IFNγ also blocked differentiation of pre-adipocytes to the mature phenotype. IFNγ-induced robust STAT1 phosphorylation and SOCS1 mRNA expression, with modest, transient STAT3 phosphorylation and SOCS3 induction. Preincubation with a non-selective JAK inhibitor restored glucose uptake and Akt phosphorylation while completely reversing IFNγ suppression of adipogenic mRNAs and adipocyte differentiation. Specific inhibition of JAK2 or JAK3 failed to block IFNγ effects suggesting a predominant role for JAK1-STAT1. We demonstrate that IFNγ attenuates insulin sensitivity and suppresses differentiation in human adipocytes, an effect most likely mediated via sustained JAK-STAT1 pathway activation. PMID:19776010

  9. Fucoxanthin Suppresses Lipid Accumulation and ROS Production During Differentiation in 3T3-L1 Adipocytes.

    PubMed

    Seo, Min-Jung; Seo, Young-Jin; Pan, Cheol-Ho; Lee, Ok-Hwan; Kim, Kui-Jin; Lee, Boo-Yong

    2016-11-01

    Fucoxanthin, a pigment from the chloroplasts of marine brown algae, has a number of effects against obesity, diabetes, inflammation and cancer and provides cerebrovascular protection. In this study, we investigated the inhibitory effects of fucoxanthin on lipid accumulation and reactive oxygen species (ROS) production during adipogenesis. Treatment with fucoxanthin suppresses protein levels of the adipogenic transcription factors CCAAT/enhancer-binding protein alpha C/EBPα and peroxisome proliferator-activated receptor-γ and of their target protein, fatty acid binding protein 4. Lipogenesis-related enzymes, such as diglyceride acyltransferase 1 and lysophosphatidic acid acyltransferase-θ, were downregulated by fucoxanthin. The ROS-producing enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) and the NADPH-generating enzyme glucose-6-phosphate dehydrogenase also decreased following fucoxanthin treatment. The adipokine adiponectin and the ROS-scavenging enzymes superoxide dismutase 2, glutathione reductase and catalase were dose-dependently increased by fucoxanthin. Furthermore, lipolysis-related enzymes and superoxide dismutase 1 were slightly decreased, because of the suppression of lipid-generating factors and the cytosolic enzyme NOX4. To confirm these results, we investigated lipid accumulation and ROS production in zebrafish, where fucoxanthin suppressed lipid and triglyceride accumulation, as well as ROS production. Our data suggest that fucoxanthin inhibits lipid accumulation and ROS production by controlling adipogenic and lipogenic factors and ROS-regulating enzymes. Copyright © 2016 John Wiley & Sons, Ltd.

  10. The increasingly complex regulation of adipocyte differentiation

    PubMed Central

    Poulos, Sylvia P; Dodson, Michael V; Culver, Melinda F

    2015-01-01

    Adipose (AD) tissue development and function relies on the ability of adipocytes to proliferate and differentiate into lipid-containing cells that also have endocrine function. Research suggests that certain conditions can induce AD tissue stem cells to differentiate into various cell types and that the microenvironment of the cell, including the extracellular matrix (ECM), is essential in maintaining cell and tissue function. This review provides an overview of factors involved in the proliferation and differentiation of adipocytes. A brief review of the numerous factors that influence PPARγ, the transcription factor thought to be the master regulator of adipocyte differentiation, provides context of established pathways that regulate adipogenesis. Thought provoking findings from research with hypoxia that is supported by earlier research that vascular development is related to adipogenesis are reviewed. Finally, our understanding of the critical role of the ECM and environment in adipogenesis is discussed and compared with studies that suggest that adipocytes may dedifferentiate and can convert into other cell types. PMID:26645953

  11. Mango (Mangifera indica L.) peel extract fractions from different cultivars differentially affect lipid accumulation in 3T3-L1 adipocyte cells.

    PubMed

    Taing, Meng-Wong; Pierson, Jean-Thomas; Shaw, Paul N; Dietzgen, Ralf G; Roberts-Thomson, Sarah J; Gidley, Michael J; Monteith, Gregory R

    2013-02-26

    Plant phytochemicals are increasingly recognised as sources of bioactive molecules which may have potential benefit in many health conditions. In mangoes, peel extracts from different cultivars exhibit varying effects on adipogenesis in the 3T3-L1 adipocyte cell line. In this study, the effects of preparative HPLC fractions of methanol peel extracts from Irwin, Nam Doc Mai and Kensington Pride mangoes were evaluated. Fraction 1 contained the most hydrophilic components while subsequent fractions contained increasingly more hydrophobic components. High content imaging was used to assess mango peel fraction effects on lipid accumulation, nuclei count and nuclear area in differentiating 3T3-L1 cells. For all three mango cultivars, the more hydrophilic peel fractions 1-3 inhibited lipid accumulation with greater potency than the more hydrophobic peel fractions 4. For all three cultivars, the more lipophilic fraction 4 had concentrations that enhanced lipid accumulation greater than fractions 1-3 as assessed by lipid droplet integrated intensity. The potency of this fraction 4 varied significantly between cultivars. Using mass spectrometry, five long chain free fatty acids were detected in fraction 4; these were not present in any other peel extract fractions. Total levels varied between cultivars, with Irwin fraction 4 containing the highest levels of these free fatty acids. Lipophilic components appear to be responsible for the lipid accumulation promoting effects of some mango extracts and are the likely cause of the diverse effects of peel extracts from different mango cultivars on lipid accumulation.

  12. Saw palmetto ethanol extract inhibits adipocyte differentiation.

    PubMed

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

    2013-07-01

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

  13. Effects of parabens on adipocyte differentiation.

    PubMed

    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.

  14. Differentiation of preadipocytes and mature adipocytes requires PSMB8

    PubMed Central

    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

  15. 10e12z CLA alters adipocyte differentiation and adipocyte cytokine expression and induces macrophage proliferation.

    PubMed

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

    2012-05-01

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

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

    SciTech Connect

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

    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.

  17. Annexin A6 regulates adipocyte lipid storage and adiponectin release.

    PubMed

    Krautbauer, Sabrina; Haberl, Elisabeth M; Eisinger, Kristina; Pohl, Rebekka; Rein-Fischboeck, Lisa; Rentero, Carles; Alvarez-Guaita, Anna; Enrich, Carlos; Grewal, Thomas; Buechler, Christa; Neumeier, Markus

    2017-01-05

    Lipid storage and adipokine secretion are critical features of adipocytes. Annexin A6 (AnxA6) is a lipid-binding protein regulating secretory pathways and its role in adiponectin release was examined. The siRNA-mediated AnxA6 knock-down in 3T3-L1 preadipocytes impaired proliferation, and differentiation of AnxA6-depleted cells to mature adipocytes was associated with higher soluble adiponectin and increased triglyceride storage. The latter was partly attributed to reduced lipolysis. Accordingly, AnxA6 overexpression in 3T3-L1 adipocytes lowered cellular triglycerides and adiponectin secretion. Indeed, serum adiponectin was increased in AnxA6 deficient mice. Expression analysis identified AnxA6 protein to be more abundant in intra-abdominal compared to subcutaneous adipose tissues of mice and men. AnxA6 protein levels increased in white adipose tissues of obese mice and here, levels were highest in subcutaneous fat. AnxA6 protein in adipocytes was upregulated by oxidative stress which might trigger AnxA6 induction in adipose tissues and contribute to impaired fat storage and adiponectin release.

  18. The effect of dehydroleucodine in adipocyte differentiation.

    PubMed Central

    Galvis, Adriana; Marcano, Adriana; Stefancin, Chad; Villaverde, Nicole; Priestap, Horacio A.; Tonn, Carlos E.; Lopez, Luis A.; Barbieri, Manuel A.

    2012-01-01

    Dehydroleucodine (DhL) is a sesquiterpene lactone of the guaianolide group with gastric citoprotective activity. Recent studies have also demonstrated that DhL inhibits the proliferation of vascular smooth muscle cells. In this study we examined the effect of DhL in the differentiation 3T3-L1 preadipocytes. The addition of DhL significantly inhibited the differentiation 3T3-L1 preadipocytes along with significant decrease in the accumulation of lipid content by a dramatic down regulation of the expression of adipogenic-specific transcriptional factors PPARγ and C-EBPα. However, phosphorylation of AMPKα, Erk1/2 and Akt1 was not inhibited by DhL treatment. Interestingly, we also found that 11,13-dihydro-dehydroleucodine, a derivative of DhL with inactivated α-methylene-γ-lactone function, also inhibited the differentiation 3T3-L1 preadipocytes. Taken together, these data suggest DhL has an important inhibitory effect in cellular pathways regulating adipocyte differentiation by modulating the PPARγ expression, which is known to play a pivotal role during adipogenesis. PMID:21963454

  19. Follistatin promotes adipocyte differentiation, browning, and energy metabolism.

    PubMed

    Braga, Melissa; Reddy, Srinivasa T; Vergnes, Laurent; Pervin, Shehla; Grijalva, Victor; Stout, David; David, John; Li, Xinmin; Tomasian, Venina; Reid, Christopher B; Norris, Keith C; Devaskar, Sherin U; Reue, Karen; Singh, Rajan

    2014-03-01

    Follistatin (Fst) functions to bind and neutralize the activity of members of the transforming growth factor-β superfamily. Fst has a well-established role in skeletal muscle, but we detected significant Fst expression levels in interscapular brown and subcutaneous white adipose tissue, and further investigated its role in adipocyte biology. Fst expression was induced during adipogenic differentiation of mouse brown preadipocytes and mouse embryonic fibroblasts (MEFs) as well as in cold-induced brown adipose tissue from mice. In differentiated MEFs from Fst KO mice, the induction of brown adipocyte proteins including uncoupling protein 1, PR domain containing 16, and PPAR gamma coactivator-1α was attenuated, but could be rescued by treatment with recombinant FST. Furthermore, Fst enhanced thermogenic gene expression in differentiated mouse brown adipocytes and MEF cultures from both WT and Fst KO groups, suggesting that Fst produced by adipocytes may act in a paracrine manner. Our microarray gene expression profiling of WT and Fst KO MEFs during adipogenic differentiation identified several genes implicated in lipid and energy metabolism that were significantly downregulated in Fst KO MEFs. Furthermore, Fst treatment significantly increases cellular respiration in Fst-deficient cells. Our results implicate a novel role of Fst in the induction of brown adipocyte character and regulation of energy metabolism.

  20. Thioredoxin reductase 1 suppresses adipocyte differentiation and insulin responsiveness

    PubMed Central

    Peng, Xiaoxiao; Giménez-Cassina, Alfredo; Petrus, Paul; Conrad, Marcus; Rydén, Mikael; Arnér, Elias S. J.

    2016-01-01

    Recently thioredoxin reductase 1 (TrxR1), encoded by Txnrd1, was suggested to modulate glucose and lipid metabolism in mice. Here we discovered that TrxR1 suppresses insulin responsiveness, anabolic metabolism and adipocyte differentiation. Immortalized mouse embryonic fibroblasts (MEFs) lacking Txnrd1 (Txnrd1−/−) displayed increased metabolic flux, glycogen storage, lipogenesis and adipogenesis. This phenotype coincided with upregulated PPARγ expression, promotion of mitotic clonal expansion and downregulation of p27 and p53. Enhanced Akt activation also contributed to augmented adipogenesis and insulin sensitivity. Knockdown of TXNRD1 transcripts accelerated adipocyte differentiation also in human primary preadipocytes. Furthermore, TXNRD1 transcript levels in subcutaneous adipose tissue from 56 women were inversely associated with insulin sensitivity in vivo and lipogenesis in their isolated adipocytes. These results suggest that TrxR1 suppresses anabolic metabolism and adipogenesis by inhibition of intracellular signaling pathways downstream of insulin stimulation. PMID:27346647

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

    SciTech Connect

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

    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 catabolism

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

    PubMed Central

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

    2016-01-01

    Administration of second-generation antipsychotic drugs (SGAs) often leads to weight gain and consequent cardio-metabolic side effects. We observed that clozapine but not six other antipsychotic drugs reprogrammed the gene expression pattern of differentiating human adipocytes ex vivo, leading to an elevated expression of the browning marker gene UCP1, more and smaller lipid droplets and more mitochondrial DNA than in the untreated white adipocytes. Laser scanning cytometry showed that up to 40% of the differentiating single primary and Simpson–Golabi–Behmel syndrome (SGBS) adipocytes had the characteristic morphological features of browning cells. Furthermore, clozapine significantly upregulated ELOVL3, CIDEA, CYC1, PGC1A and TBX1 genes but not ZIC1 suggesting induction of the beige-like and not the classical brown phenotype. When we tested whether browning induced by clozapine can be explained by its known pharmacological effect of antagonizing serotonin (5HT) receptors, it was found that browning cells expressed 5HT receptors 2A, 1D, 7 and the upregulation of browning markers was diminished in the presence of exogenous 5HT. Undifferentiated progenitors or completely differentiated beige or white adipocytes did not respond to clozapine administration. The clozapine-induced beige cells displayed increased basal and oligomycin-inhibited (proton leak) oxygen consumption, but these cells showed a lower response to cAMP stimulus as compared with control beige adipocytes indicating that they are less capable to respond to natural thermogenic anti-obesity cues. Our data altogether suggest that novel pharmacological stimulation of these masked beige adipocytes can be a future therapeutic target for the treatment of SGA-induced weight gain. PMID:27898069

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

    SciTech Connect

    Ferrante, Maria C.; Amero, Paola; Santoro, Anna; Monnolo, Anna; Simeoli, Raffaele; Di Guida, Francesca; Mattace Raso, Giuseppina; Meli, Rosaria

    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

  4. Differentiation and characterization of human facial subcutaneous adipocytes

    PubMed Central

    Chon, Su-Hyoun; Pappas, Apostolos

    2014-01-01

    Aging is associated with the loss of facial subcutaneous fat and with increased abdominal subcutaneous fat. Site specific differences in adipocyte phenotype and/or gene expression may play a role in these age-related changes. In this study, we isolated and characterized human facial preadipocytes and investigated distinct metabolic properties such as a differentiation pattern in relation to abdominal preadipocytes. Subcutaneous preadipocytes were isolated from human facial and abdominal skin and cultured in the presence of differentiation factors including rosiglitazone, a known peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist, isobutyl-methyl xanthine (IBMX) and insulin. Differentiation was characterized microscopically and by quantitative real-time PCR. Unexpected superior adipogenic capacity of facial preadipocytes was observed; more facial preadipocytes differentiated in response to rosiglitazone than abdominal preadipocytes and facial preadipocytes retained their ability to differentiate through passage 11 compared with passage 5 for abdominal preadipocytes. Experiments confirmed a reduced lipolysis response in facial versus abdominal adipocytes after exposure to isoproterenol, which was consistent with the reduced β2-adrenergic receptor expression by 60% in the facial cells. The expression of other lipid metabolic gene markers was similar in both facial and abdominal adipocytes with the exception of β3-adrenergic receptor which was only found in abdominal adipose tissue. Gene profiling, by microarray analysis, identified that several HOX genes are robustly reduced in facial adipocytes compared to abdominal adipocytes, suggesting different characteristics between the 2 fat depots. These differences may have implications for development of treatments for facial fat loss during aging. PMID:26167398

  5. Effects of fermented rooibos (Aspalathus linearis) on adipocyte differentiation.

    PubMed

    Sanderson, Micheline; Mazibuko, Sithandiwe E; Joubert, Elizabeth; de Beer, Dalene; Johnson, Rabia; Pheiffer, Carmen; Louw, Johan; Muller, Christo J F

    2014-01-15

    Rooibos (Aspalathus linearis) contains a rich complement of polyphenols, including flavonoids, considered to be largely responsible for its health promoting effects, including combatting obesity. The purpose of this study was to examine the effect of fermented rooibos hot water soluble solids on in vitro adipocyte differentiation by using differentiating 3T3-L1 adipocytes. Hot water soluble solids were obtained when preparing an infusion of fermented rooibos at "cup-of-tea" strength. The major phenolic compounds (>5 mg/g) were isoorientin, orientin, quercetin-3-O-robinobioside and enolic phenylpyruvic acid-2-O-β-D-glucoside. Treatment of 3T3-L1 adipocytes with 10 μg/ml and 100 μg/ml of the rooibos soluble solids inhibited intracellular lipid accumulation by 22% (p<0.01) and 15% (p<0.05), respectively. Inhibition of adipogenesis was accompanied by decreased messenger RNA (mRNA) expression of PPARγ, PPARα, SREBF1 and FASN. Western blot analysis exhibited decreased PPARα, SREBF1 and AMPK protein expression. Impeded glycerol release into the culture medium was observed after rooibos treatment. None of the concentrations of rooibos hot water soluble solids was cytotoxic, in terms of ATP content. Interestingly, the higher concentration of hot water soluble solids increased ATP concentrations which were associated with increased basal glucose uptake. Decreased leptin secretion was observed after rooibos treatment. Our data show that hot water soluble solids from fermented rooibos inhibit adipogenesis and affect adipocyte metabolism, suggesting its potential in preventing obesity.

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

    PubMed Central

    Brunmeir, Reinhard; Zhang, Qiongyi; Li, Hongyu; Dharmasegaran, Dharmini; Leong, Carol; Lim, Ying Yan; Han, Weiping

    2017-01-01

    Adipose tissues constitute an important component of metabolism, the dysfunction of which can cause obesity and type II diabetes. Here we show that differentiation of white and brown adipocytes requires Deleted in Liver Cancer 1 (DLC1), a Rho GTPase Activating Protein (RhoGAP) previously studied for its function in liver cancer. We identified Dlc1 as a super-enhancer associated gene in both white and brown adipocytes through analyzing the genome-wide binding profiles of PPARγ, the master regulator of adipogenesis. We further observed that Dlc1 expression increases during differentiation, and knockdown of Dlc1 by siRNA in white adipocytes reduces the formation of lipid droplets and the expression of fat marker genes. Moreover, knockdown of Dlc1 in brown adipocytes reduces expression of brown fat-specific genes and diminishes mitochondrial respiration. Dlc1-/- knockout mouse embryonic fibroblasts show a complete inability to differentiate into adipocytes, but this phenotype can be rescued by inhibitors of Rho-associated kinase (ROCK) and filamentous actin (F-actin), suggesting the involvement of Rho pathway in DLC1-regulated adipocyte differentiation. Furthermore, PPARγ binds to the promoter of Dlc1 gene to regulate its expression during both white and brown adipocyte differentiation. These results identify DLC1 as an activator of white and brown adipocyte differentiation, and provide a molecular link between PPARγ and Rho pathways. PMID:28358928

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

    PubMed

    Sim, Choon Kiat; Kim, Sun-Yee; Brunmeir, Reinhard; Zhang, Qiongyi; Li, Hongyu; Dharmasegaran, Dharmini; Leong, Carol; Lim, Ying Yan; Han, Weiping; Xu, Feng

    2017-01-01

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

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

    PubMed Central

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

    2015-01-01

    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 enhanced

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

    PubMed Central

    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. BMP-TAK1 (MAP3K7) Induces Adipocyte Differentiation Through PPARγ Signaling.

    PubMed

    Zhang, Yongchun; O'Keefe, Regis J; Jonason, Jennifer H

    2017-01-01

    BMPs have been shown to promote adipocyte differentiation through SMAD-dependent signaling. However, the role of TGF-β-activated kinase 1 (TAK1) in non-canonical BMP signaling in adipocyte differentiation remains unclear. Here, we show that TAK1 inhibition decreases lipid accumulation in C3H10T1/2 mesenchymal stem cells (MSCs) induced to differentiate into adipocytes. TAK1 knockdown by siRNA further confirms that TAK1 is required for adipocyte commitment of MSCs. Additionally, TAK1 knockdown inhibits adipogenesis of 3T3-L1 preadipocytes, indicating that TAK1 is not only needed for adipocyte commitment, but also required for adipocyte terminal differentiation. Furthermore, TAK1 ablation specifically in adipocytes reduced high fat diet-induced weight gain and improved glucose tolerance. Mechanistically, we demonstrate that TAK1 is required for PPARγ transactivation and promotes PPARγ transcriptional activity synergistically with TAK1 binding protein 1 (TAB1). Collectively, our results demonstrate that TAK1 plays a critical role in BMP-mediated adipocyte differentiation. J. Cell. Biochem. 118: 204-210, 2017. © 2016 Wiley Periodicals, Inc.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. Olanzapine promotes the accumulation of lipid droplets and the expression of multiple perilipins in human adipocytes.

    PubMed

    Nimura, Satomi; Yamaguchi, Tomohiro; Ueda, Koki; Kadokura, Karin; Aiuchi, Toshihiro; Kato, Rina; Obama, Takashi; Itabe, Hiroyuki

    2015-11-27

    Second generation antipsychotics are useful for the treatment of schizophrenia, but concerns have been raised about the side effects of diabetes mellitus and obesity. Olanzapine, especially, is associated with more weight gain than the others. It has been reported that olanzapine promotes adipocyte-differentiation in rodents both in vivo and in vitro. In this study the effects of antipsychotics on human adipocytes were investigated by using human mesenchymal stem cells (hMSCs). When hMSCs were differentiated and treated with various antipsychotics, olanzapine and clozapine increased intracellular lipids. Olanzapine induced lipid accumulation in a dose-dependent manner. Proteomic analysis revealed that PLIN4 and several enzymes for lipid metabolism were increased in the hMSCs after olanzapine treatment. During adipocyte differentiation, olanzapine increased the protein expression of PLIN1, PLIN2 and PLIN4. These proteins are known to be associated with the initial stage of lipid droplet formation. Immunocytochemistry showed that olanzapine increased and enlarged the lipid droplets coated with PLIN1 and PLIN2 while PLIN4 was largely distributed in the cytosol. mRNA expression of PLIN2, but not PLIN1 or PLIN4, was increased by olanzapine. On the other hand, olanzapine did not alter the mRNA level of transcription regulators involved in adipocyte-differentiation or adipokines. The present study shows that olanzapine induced transient PLIN2 expression in hMSCs that could result in an accumulation of lipid droplets and overexpression of PLIN1 and PLIN4, providing information of possible interest for olanzapine-induced weight gain.

  13. Microsomal Triglyceride Transfer Protein (MTP) Associates with Cytosolic Lipid Droplets in 3T3-L1 Adipocytes.

    PubMed

    Love, Joseph D; Suzuki, Takashi; Robinson, Delia B; Harris, Carla M; Johnson, Joyce E; Mohler, Peter J; Jerome, W Gray; Swift, Larry L

    2015-01-01

    Lipid droplets are intracellular energy storage organelles composed of a hydrophobic core of neutral lipid, surrounded by a monolayer of phospholipid and a diverse array of proteins. The function of the vast majority of these proteins with regard to the formation and/or turnover of lipid droplets is unknown. Our laboratory was the first to report that microsomal triglyceride transfer protein (MTP), a lipid transfer protein essential for the assembly of triglyceride-rich lipoproteins, was expressed in adipose tissue of humans and mice. In addition, our studies suggested that MTP was associated with lipid droplets in both brown and white fat. Our observations led us to hypothesize that MTP plays a key role in lipid droplet formation and/or turnover. The objective of these studies was to gain insight into the function of MTP in adipocytes. Using molecular, biochemical, and morphologic approaches we have shown: 1) MTP protein levels increase nearly five-fold as 3T3-L1 cells differentiate into adipocytes. 2) As 3T3-L1 cells undergo differentiation, MTP moves from the juxtanuclear region of the cell to the surface of lipid droplets. MTP and perilipin 2, a major lipid droplet surface protein, are found on the same droplets; however, MTP does not co-localize with perilipin 2. 3) Inhibition of MTP activity has no effect on the movement of triglyceride out of the cell either as a lipid complex or via lipolysis. 4) MTP is found associated with lipid droplets within hepatocytes from human fatty livers, suggesting that association of MTP with lipid droplets is not restricted to adipocytes. In summary, our data demonstrate that MTP is a lipid droplet-associated protein. Its location on the surface of the droplet in adipocytes and hepatocytes, coupled with its known function as a lipid transfer protein and its increased expression during adipocyte differentiation suggest a role in lipid droplet biology.

  14. Microsomal Triglyceride Transfer Protein (MTP) Associates with Cytosolic Lipid Droplets in 3T3-L1 Adipocytes

    PubMed Central

    Robinson, Delia B.; Harris, Carla M.; Johnson, Joyce E.; Mohler, Peter J.; Jerome, W. Gray; Swift, Larry L.

    2015-01-01

    Lipid droplets are intracellular energy storage organelles composed of a hydrophobic core of neutral lipid, surrounded by a monolayer of phospholipid and a diverse array of proteins. The function of the vast majority of these proteins with regard to the formation and/or turnover of lipid droplets is unknown. Our laboratory was the first to report that microsomal triglyceride transfer protein (MTP), a lipid transfer protein essential for the assembly of triglyceride-rich lipoproteins, was expressed in adipose tissue of humans and mice. In addition, our studies suggested that MTP was associated with lipid droplets in both brown and white fat. Our observations led us to hypothesize that MTP plays a key role in lipid droplet formation and/or turnover. The objective of these studies was to gain insight into the function of MTP in adipocytes. Using molecular, biochemical, and morphologic approaches we have shown: 1) MTP protein levels increase nearly five-fold as 3T3-L1 cells differentiate into adipocytes. 2) As 3T3-L1 cells undergo differentiation, MTP moves from the juxtanuclear region of the cell to the surface of lipid droplets. MTP and perilipin 2, a major lipid droplet surface protein, are found on the same droplets; however, MTP does not co-localize with perilipin 2. 3) Inhibition of MTP activity has no effect on the movement of triglyceride out of the cell either as a lipid complex or via lipolysis. 4) MTP is found associated with lipid droplets within hepatocytes from human fatty livers, suggesting that association of MTP with lipid droplets is not restricted to adipocytes. In summary, our data demonstrate that MTP is a lipid droplet-associated protein. Its location on the surface of the droplet in adipocytes and hepatocytes, coupled with its known function as a lipid transfer protein and its increased expression during adipocyte differentiation suggest a role in lipid droplet biology. PMID:26267806

  15. Aloe-emodin inhibits adipocyte differentiation and maturation during in vitro human mesenchymal stem cell adipogenesis.

    PubMed

    Subash-Babu, Pandurangan; Alshatwi, Ali A

    2012-08-01

    In this study, we examined the effects of Aloe-emodin (AE) on the inhibition of adipocyte differentiation during 3-isobutyl-1-methylxanthine (IBMX)-induced adipocyte differentiation in human mesenchymal stem cells (hMSCs). AE treatment (5, 10, and 20 µM) of preadipocyte cells resulted in a significant (p < 0.05) decrease in glycerol phosphate dehydrogenase and triglyceride levels as well as an increase in lactate dehydrogenase activity and attenuated lipid accumulation compared with untreated differentiated adipocytes. Using quantitative reverse transcription polymerase chain reaction, we studied the mRNA expression levels of resistin, adiponectin, aP(2), lipoprotein lipase, PPARγ, and tumor necrosis factor-α in hMSCs undergoing adipocyte differentiation; treatment with AE decreased the expression of these adipogenic genes and decreased adipocyte differentiation. In addition, AE suppresses the differentiation of hMSCs into adipocytes by downregulating PPARγ and C/EBPα expressions. AE significantly inhibited hMSCs proliferation and preadipocyte differentiation within the first 2 days of treatment, indicating that the antiadipogenic effect.

  16. Differentiation of Pre-Adipocytes in Modelled Microgravity

    NASA Astrophysics Data System (ADS)

    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.

  17. The mechanism of white and brown adipocyte differentiation.

    PubMed

    Nakagami, Hironori

    2013-04-01

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

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

    SciTech Connect

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

    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

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

    PubMed

    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].

  20. Methyltransferase and demethylase profiling studies during brown adipocyte differentiation

    PubMed Central

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

    2016-01-01

    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] PMID:27157542

  1. ReishiMax, mushroom based dietary supplement, inhibits adipocyte differentiation, stimulates glucose uptake and activates AMPK

    PubMed Central

    2011-01-01

    Background Obesity is a health hazard which is closely associated with various complications including insulin resistance, hypertension, dyslipidemia, atherosclerosis, type 2 diabetes and cancer. In spite of numerous preclinical and clinical interventions, the prevalence of obesity and its related disorders are on the rise demanding an urgent need for exploring novel therapeutic agents that can regulate adipogenesis. In the present study, we evaluated whether a dietary supplement ReishiMax (RM), containing triterpenes and polysaccharides extracted from medicinal mushroom Ganoderma lucidum, affects adipocyte differentiation and glucose uptake in 3T3-L1 cells. Methods 3T3-L1 pre-adipocytes were differentiated into adipocytes and treated with RM (0-300 μg/ml). Adipocyte differentiation/lipid uptake was evaluated by oil red O staining and triglyceride and glycerol concentrations were determined. Gene expression was evaluated by semi-quantitative RT-PCR and Western blot analysis. Glucose uptake was determined with [3H]-glucose. Results RM inhibited adipocyte differentiation through the suppresion of expression of adipogenic transcription factors peroxisome proliferator-activated receptor-γ (PPAR-γ), sterol regulatory element binding element protein-1c (SREBP-1c) and CCAAT/enhancer binding protein-α (C/EBP-α). RM also suppressed expression of enzymes and proteins responsible for lipid synthesis, transport and storage: fatty acid synthase (FAS), acyl-CoA synthetase-1 (ACS1), fatty acid binding protein-4 (FABP4), fatty acid transport protein-1 (FATP1) and perilipin. RM induced AMP-activated protein kinase (AMPK) and increased glucose uptake by adipocytes. Conclusion Our study suggests that RM can control adipocyte differentiation and glucose uptake. The health benefits of ReishiMax warrant further clinical studies. PMID:21929808

  2. Phytanic acid, a novel activator of uncoupling protein-1 gene transcription and brown adipocyte differentiation.

    PubMed Central

    Schlüter, Agatha; Barberá, Maria José; Iglesias, Roser; Giralt, Marta; Villarroya, Francesc

    2002-01-01

    Phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) is a phytol-derived branched-chain fatty acid present in dietary products. Phytanic acid increased uncoupling protein-1 (UCP1) mRNA expression in brown adipocytes differentiated in culture. Phytanic acid induced the expression of the UCP1 gene promoter, which was enhanced by co-transfection with a retinoid X receptor (RXR) expression vector but not with other expression vectors driving peroxisome proliferator-activated receptor (PPAR)alpha, PPARgamma or a form of RXR devoid of ligand-dependent sensitivity. The effect of phytanic acid on the UCP1 gene required the 5' enhancer region of the gene and the effects of phytanic acid were mediated in an additive manner by three binding sites for RXR. Moreover, phytanic acid activates brown adipocyte differentiation: long-term exposure of brown preadipocytes to phytanic acid promoted the acquisition of the brown adipocyte morphology and caused a co-ordinate induction of the mRNAs for gene markers of brown adipocyte differentiation, such as UCP1, adipocyte lipid-binding protein aP2, lipoprotein lipase, the glucose transporter GLUT4 or subunit II of cytochrome c oxidase. In conclusion, phytanic acid is a natural product of phytol metabolism that activates brown adipocyte thermogenic function. It constitutes a potential nutritional signal linking dietary status to adaptive thermogenesis. PMID:11829740

  3. Study of the proinflammatory role of human differentiated omental adipocytes.

    PubMed

    Bassols, Judit; Ortega, Francisco J; Moreno-Navarrete, José M; Peral, Belén; Ricart, Wifredo; Fernández-Real, Jose-Manuel

    2009-08-15

    Infiltration of monocyte-derived macrophages into adipose tissue has been associated with tissue and systemic inflammation. It has been suggested that macrophage infiltration affects fat expansion through a paracrine action on adipocyte differentiation. Our working hypothesis is that factors released by monocytes/macrophages may also affect mature adipocyte biology. Human differentiated omental adipocytes were incubated with LPS and conditioned media obtained from human macrophage-like cell line THP-1, previously activated or not with LPS. We show that LPS greatly increased the secretion levels of pro-inflammatory adipokines including IL-6, IL-8, GRO, and MCP-1. Macrophage-conditioned medium also upregulated IL-6, IL-8, GRO, and MCP-1 mRNA expression and protein levels and led to the novo secretion of ICAM-1, IL-1 beta, IP-10, MIP-1 alpha, MIP-1 beta, VEGF, and TNFalpha. Human differentiated adipocytes treated by macrophage-conditioned medium displayed marked reduction of adipocyte function as assessed by decreased phosphorylation levels of ERK1, ERK2, and p38 alpha and reduced gene expression of lipogenic markers including PPAR-gamma and fatty acid synthase. These data show that macrophage-secreted factors not only inhibit the formation of mature adipocytes but alter their function, suggesting that human differentiated omental adipocytes might also contribute to systemic chronic low-grade inflammation associated with human obesity.

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

    PubMed

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

    2015-12-01

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

  5. Carbamazepine directly inhibits adipocyte differentiation through activation of the ERK 1/2 pathway

    PubMed Central

    Turpin, E; Muscat, A; Vatier, C; Chetrite, G; Corruble, E; Moldes, M; Fève, B

    2013-01-01

    Background and Purpose Carbamazepine (CBZ), known for its anti-epileptic, analgesic and mood-stabilizing properties, is also known to induce weight gain but the pathophysiology of this adverse effect is still largely unknown. We tested the hypothesis that CBZ could have a direct effect on adipocyte development and metabolism. Experimental Research We studied the effects of CBZ on morphological biochemical and molecular markers of adipogenesis, using several pre-adipocyte murine cell lines (3T3-L1, 3T3-F442A and T37i cells) and primary cultures of human pre-adipocytes. To delineate the mechanisms underlying the effect of CBZ, clonal expansion of pre-adipocytes, pro-adipogenic transcription factors, glucose uptake and lipolysis were also examined. Key Results CBZ strongly inhibited pre-adipocyte differentiation and triglyceride accumulation in a time- and dose-dependent manner in all models. Pleiotropic mechanisms were at the basis of the inhibitory effects of CBZ on adipogenesis and cell lipid accumulation. They included suppression of both clonal expansion and major adipogenic transcription factors such as PPAR-γ and CCAAT/enhancer binding protein-α, activation of basal lipolysis and decrease in insulin-stimulated glucose transport. Conclusions and Implications The effect of CBZ on adipogenesis involves activation of the ERK1/2 pathway. Our results show that CBZ acts directly on pre-adipocytes and adipocytes to alter adipose tissue development and metabolism. PMID:22889231

  6. Honokiol enhances adipocyte differentiation by potentiating insulin signaling in 3T3-L1 preadipocytes.

    PubMed

    Choi, Sun-Sil; Cha, Byung-Yoon; Iida, Kagami; Sato, Masako; Lee, Young-Sil; Teruya, Toshiaki; Yonezawa, Takayuki; Nagai, Kazuo; Woo, Je-Tae

    2011-07-01

    Adipose tissue plays an essential role in energy homeostasis as a metabolic and endocrine organ. Accordingly, adipocytes are emerging as a major drug target for obesity and obesity-mediated metabolic syndrome. Dysfunction of enlarged adipocytes in obesity is involved in obesity-mediated metabolic syndrome. Adipocytokines, such as adiponectin released from small adipocytes, are able to prevent these disorders. In this study, we found that honokiol, an ingredient of Magnolia officinalis used in traditional Chinese and Japanese medicines, enhanced adipocyte differentiation in 3T3-L1 preadipocytes. Oil Red O staining showed that treatment with honokiol in the presence of insulin dose-dependently increased lipid accumulation in 3T3-L1 preadipoyctes although its activity was weak compared with rosiglitazone. During adipocyte differentiation, the expression of peroxisome proliferator-activated receptor γ2 (PPARγ2) mRNA and PPARγ target genes such as adipocyte protein 2 (aP2), adiponectin, and GLUT4 was induced by treatment with 10 μM honokiol. However, honokiol failed to show direct binding to the PPARγ ligand-binding domain in vitro. In preadipocytes, treatment with honokiol in the presence of insulin increased the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 protein and Akt protein, early insulin signaling pathways related to adipocyte differentiation, compared with insulin-only treatment. Taken together, our results suggest that honokiol promotes adipocyte differentiation through increased expression of PPARγ2 mRNA and potentiation of insulin signaling pathways such as the Ras/ERK1/2 and phosphoinositide-3-kinase (PI3K)/Akt signaling pathways.

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

    SciTech Connect

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

    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

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

    SciTech Connect

    Suzuki, Shunichi; Suzuki, Misae; Sembon, Shoichiro; Fuchimoto, Daiichiro; Onishi, Akira

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

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

    2015-01-01

    Lipid droplets (LDs) hypertrophy in adipocytes is the main cause of energy metabolic system dysfunction, obesity and its afflictions such as T2D. However, the role of adipocytes in linking energy metabolic disorders with insulin regulation is unknown in humans. Human adipocytes constitutively synthesize and secrete insulin, which is biologically functional. Insulin concentrations and release are fat mass- and LDs-dependent respectively. Fat reduction mediated by bariatric surgery repairs obesity-associated T2D. The expression of genes, like PCSK1 (proinsulin conversion enzyme), GCG (Glucagon), GPLD1, CD38 and NNAT, involved in insulin regulation/release were differentially expressed in pancreas and adipose tissue (AT). INS (insulin) and GCG expression reduced in human AT-T2D as compared to AT-control, but remained unchanged in pancreas in either state. Insulin levels (mRNA/protein) were higher in AT derived from prediabetes BB rats with destructed pancreatic β-cells and controls than pancreas derived from the same rats respectively. Insulin expression in 10 human primary cell types including adipocytes and macrophages is an evidence for extrapancreatic insulin-producing cells. The data suggest a crosstalk between AT and pancreas to fine-tune energy metabolic system or may minimize the metabolic damage during diabetes. This study opens new avenues towards T2D therapy with a great impact on public health. PMID:25743104

  11. Vestigial-like 3 is an inhibitor of adipocyte differentiation.

    PubMed

    Halperin, Daniel S; Pan, Calvin; Lusis, Aldons J; Tontonoz, Peter

    2013-02-01

    Adipose differentiation is a complex process controlled by a network of transcription factors and co-regulators. We compared the global gene expression patterns of adipogenic and nonadipogenic clones of 3T3-F442A preadipocytes and identified the transcriptional cofactor, vestigial-like 3 (Vgll3), as an inhibitor of adipogenesis. Vgll3 expression is down-regulated during terminal adipocyte differentiation in vitro and negatively correlates with weight and total fat mass in vivo. Furthermore, enforced Vgll3 expression inhibits the differentiation of preadipocytes in vitro, whereas shRNA-mediated knockdown of Vgll3 expression promotes differentiation. Expression of Vgll3 promoted the expression of genes associated with bone and chondrocyte formation, suggesting that Vgll3 participates in the decision of mesenchymal cells to proceed down the adipocyte, bone, or cartilage lineages. The elucidation of factors involved in specification of the adipocyte phenotype may aid in the identification of new strategies for the treatment of metabolic disease.

  12. Coprinus comatus Cap Inhibits Adipocyte Differentiation via Regulation of PPARγ and Akt Signaling Pathway

    PubMed Central

    Jang, Sun-Hee; Kang, Suk Nam; Jeon, Beong-Sam; Ko, Yeoung-Gyu; Kim, Hong-Duck; Won, Chung-Kil; Kim, Gon-Sup; Cho, Jae-Hyeon

    2014-01-01

    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 Akt pathway in 3T3

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

    PubMed Central

    Lin, Yu-Chun; Chang, Yu-Tzu; Lu, Chia-Yun; Chen, Tzu-Yu; Yeh, Chia-Shan

    2016-01-01

    The adipocyte is unique in its capacity to store lipids. In addition to triglycerides, the adipocyte stores a significant amount of cholesterol. Moreover, obese adipocytes are characterized by a redistribution of cholesterol with depleted cholesterol in the plasma membrane, suggesting that cholesterol perturbation may play a role in adipocyte dysfunction. We used methyl-β-cyclodextrin (MβCD), a molecule with high affinity for cholesterol, to rapidly deplete cholesterol level in differentiated 3T3-L1 adipocytes. We tested whether this perturbation altered adipocyte secretion of monocyte chemoattractant protein-1 (MCP-1), a chemokine that is elevated in obesity and is linked to obesity-associated chronic diseases. Depletion of cholesterol by MβCD increased MCP-1 secretion as well as the mRNA and protein levels, suggesting perturbation at biosynthesis and secretion. Pharmacological inhibition revealed that NF-κB, but not MEK, p38 and JNK, was involved in MβCD-stimulated MCP-1 biosynthesis and secretion in adipocytes. Finally, another cholesterol-binding drug, filipin, also induced MCP-1 secretion without altering membrane cholesterol level. Interestingly, both MβCD and filipin disturbed the integrity of lipid rafts, the membrane microdomains enriched in cholesterol. Thus, the depletion of membrane cholesterol in obese adipocytes may result in dysfunction of lipid rafts, leading to the elevation of proinflammatory signaling and MCP-1 secretion in adipocytes. PMID:28030645

  14. Cell line models for differentiation: preadipocytes and adipocytes.

    PubMed

    Poulos, Sylvia P; Dodson, Michael V; Hausman, Gary J

    2010-10-01

    In vitro models have been invaluable in determining the mechanisms involved in adipocyte proliferation, differentiation, adipokine secretion and gene/protein expression. The cells presently available for research purposes all have unique advantages and disadvantages that one should be aware of when selecting cells. Established cell lines, such as 3T3-L1 cells, are easier and less costly to use than freshly isolated cells, even though freshly isolated cells allow for various comparisons such as the in vitro evaluation of different in vivo conditions that may not be possible using cell lines. Moreover, stem cells, transdifferentiated cells or dedifferentiated cells are relatively new cell models being evaluated for the study of adipocyte regulation and physiology. The focus of this brief review is to highlight similarities and differences in adipocyte models to aid in appropriate model selection and data interpretation for successful advancement of our understanding of adipocyte biology.

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

    PubMed

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

    2016-03-01

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

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

    PubMed

    Wang, Jiexin; Rajbhandari, Prashant; Damianov, Andrey; Han, Areum; Sallam, Tamer; Waki, Hironori; Villanueva, Claudio J; Lee, Stephen D; Nielsen, Ronni; Mandrup, Susanne; Reue, Karen; Young, Stephen G; Whitelegge, Julian; Saez, Enrique; Black, Douglas L; Tontonoz, Peter

    2017-03-01

    A highly orchestrated gene expression program establishes the properties that define mature adipocytes, but the contribution of posttranscriptional factors to the adipocyte phenotype is poorly understood. Here we have shown that the RNA-binding protein PSPC1, a component of the paraspeckle complex, promotes adipogenesis in vitro and is important for mature adipocyte function in vivo. Cross-linking and immunoprecipitation followed by RNA sequencing revealed that PSPC1 binds to intronic and 3'-untranslated regions of a number of adipocyte RNAs, including the RNA encoding the transcriptional regulator EBF1. Purification of the paraspeckle complex from adipocytes further showed that PSPC1 associates with the RNA export factor DDX3X in a differentiation-dependent manner. Remarkably, PSPC1 relocates from the nucleus to the cytoplasm during differentiation, coinciding with enhanced export of adipogenic RNAs. Mice lacking PSPC1 in fat displayed reduced lipid storage and adipose tissue mass and were resistant to diet-induced obesity and insulin resistance due to a compensatory increase in energy expenditure. These findings highlight a role for PSPC1-dependent RNA maturation in the posttranscriptional control of adipose development and function.

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

    SciTech Connect

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

    2012-04-27

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

  18. Deleted in breast cancer 1 plays a functional role in adipocyte differentiation.

    PubMed

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

    2015-04-01

    Genetic deletion of Dbc1 in mice reduced adipose tissue senescence and inflammation while promoting an expansion of this tissue. Here, we aimed to investigate DBC1 mRNA and protein levels in human adipose tissue from subjects with a wide spectrum of fat mass (cohort 1; n = 105) and insulin resistance (cohort 2; n = 47); we also investigated the effects of DBC1 knockdown on 3T3-L1 adipocyte differentiation. DBC1 mRNA was relatively abundant in both visceral (VAT) and subcutaneous adipose tissue (SAT) (mainly in the adipocyte fraction), being decreased in adipose tissue from obese compared with lean subjects. In both VAT and SAT, DBC1 mRNA levels were negatively associated with BMI and positively associated with age and the expression of PPARγ, GLUT4, IRS1, lipogenic (FASN, ACACA), lipid droplet-associated genes (PLIN1, FSP27, ADRP, and TIP47), and lipolytic (ABDH5, AKAP, and PRKACA) genes but negatively associated with ADIPOQ in VAT. DBC1 mRNA and protein levels were increased in the early stages of adipocyte differentiation of human and 3T3-L1 adipocytes. Dbc1 knockdown (KD) with lentivirus led to enhanced adipocyte differentiation, increasing intracellular lipid accumulation and adipogenic gene expression. In conclusion, although DBC1 gene expression was reduced in adipose tissue from obese subjects, it was negatively associated with ADIPOQ gene expression in VAT, suggesting that DBC1 might promote visceral adipose tissue dysfunction. In vitro data supported the antiadipogenic effects of DBC1.

  19. Nobiletin enhances differentiation and lipolysis of 3T3-L1 adipocytes

    SciTech Connect

    Saito, Takeshi; Abe, Daigo; Sekiya, Keizo . E-mail: ksekiya@affrc.go.jp

    2007-06-01

    Nobiletin is a polymethoxylated flavone found in certain citrus fruits. Here we demonstrate that nobiletin enhance differentiation of 3T3-L1 preadipocytes. Nobiletin dose-dependently increased accumulation of lipid droplets in adipocytes. Quantitative RT-PCR analyses indicated that nobiletin increased the expression of genes critical for acquisition of the adipocyte phenotype. Some of them were known peroxisome proliferator activated receptor {gamma} (PPAR{gamma}) targets and PPAR{gamma} itself, however, nobiletin did not exhibit PPAR{gamma} ligand activity. We observed the expression of CCAAT/enhancer binding protein {beta} (C/EBP{beta}), a transcription factor for PPAR{gamma}, was increased by nobiletin. The activation of cAMP-responsive element binding protein (CREB) and extracellular signal-regulated kinase (ERK), which play important roles in C/EBP{beta} expression were also potentiated by nobiletin. Furthermore, nobiletin stimulated lipolysis in differentiated adipocytes, which is known to be stimulated by cAMP pathway. These results suggested that nobiletin enhanced both differentiation and lipolysis of adipocyte through activation of signaling cascades mediated by cAMP/CREB.

  20. Cirsium japonicum flavones enhance adipocyte differentiation and glucose uptake in 3T3-L1 cells.

    PubMed

    Liao, Zhiyong; Wu, Zhihua; Wu, Mingjiang

    2012-01-01

    Cirsium japonicum flavones have been demonstrated to possess anti-diabetic effects in diabetic rats, but the functional mechanism remains unknown. The nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) plays an important role in glucose and lipid homeostasis. In this study, we report the effects of Cirsium japonicum flavones (pectolinarin and 5,7-dihydroxy-6,4-dimethoxy flavone) on PPARγ activation, adipocyte differentiation, and glucose uptake in 3T3-L1 cells. Reporter gene assays and Oil Red O staining showed that Cirsium japonicum flavones induced PPARγ activation and enhanced adipocyte differentiation of 3T3-L1 cells in a dose-dependent manner. In addition, Cirsium japonicum flavones increased the expression of PPARγ target genes, such as adiponectin and glucose transporter 4 (GLUT4), and enhanced the translocation of intracellular GLUT4 to the plasma membrane. In mature 3T3-L1 adipocytes, Cirsium japonicum flavones significantly enhanced the basal and insulin-stimulated glucose uptake. The flavones-induced effects in 3T3-L1 cells were abolished by the PPARγ antagonist, GW9662, and by the phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin. This study suggests that Cirsium japonicum flavones promote adipocyte differentiation and glucose uptake by inducing PPARγ activation and then modulating the insulin signaling pathway in some way, which could benefit diabetes patients.

  1. Salt modulates the stability and lipid binding affinity of the adipocyte lipid-binding proteins

    NASA Technical Reports Server (NTRS)

    Schoeffler, Allyn J.; Ruiz, Carmen R.; Joubert, Allison M.; Yang, Xuemei; LiCata, Vince J.

    2003-01-01

    Adipocyte lipid-binding protein (ALBP or aP2) is an intracellular fatty acid-binding protein that is found in adipocytes and macrophages and binds a large variety of intracellular lipids with high affinity. Although intracellular lipids are frequently charged, biochemical studies of lipid-binding proteins and their interactions often focus most heavily on the hydrophobic aspects of these proteins and their interactions. In this study, we have characterized the effects of KCl on the stability and lipid binding properties of ALBP. We find that added salt dramatically stabilizes ALBP, increasing its Delta G of unfolding by 3-5 kcal/mol. At 37 degrees C salt can more than double the stability of the protein. At the same time, salt inhibits the binding of the fluorescent lipid 1-anilinonaphthalene-8-sulfonate (ANS) to the protein and induces direct displacement of the lipid from the protein. Thermodynamic linkage analysis of the salt inhibition of ANS binding shows a nearly 1:1 reciprocal linkage: i.e. one ion is released from ALBP when ANS binds, and vice versa. Kinetic experiments show that salt reduces the rate of association between ANS and ALBP while simultaneously increasing the dissociation rate of ANS from the protein. We depict and discuss the thermodynamic linkages among stability, lipid binding, and salt effects for ALBP, including the use of these linkages to calculate the affinity of ANS for the denatured state of ALBP and its dependence on salt concentration. We also discuss the potential molecular origins and potential intracellular consequences of the demonstrated salt linkages to stability and lipid binding in ALBP.

  2. Shrinking and development of lipid droplets in adipocytes during catecholamine-induced lipolysis.

    PubMed

    Nagayama, Masafumi; Shimizu, Kyoko; Taira, Toshio; Uchida, Tsutomu; Gohara, Kazutoshi

    2010-01-04

    Time-lapse observation of adipocytes during catecholamine-induced lipolysis clearly shows that shrinking of existing lipid droplets (LDs) occurs in some adipocytes and that small LDs are newly developed in almost all cells. Immunofluorescence imaging reveals that activation and localization of hormone-sensitive lipase (HSL) on the surface of LDs, which are required for conferring maximal lipolysis, are necessary for the shrinking of the LDs. However, not all adipocytes in which phosphorylated HSL is localized on LDs exhibit shrinking of LDs. The simultaneous shrinking and development of LDs yield apparent fragmentation and dispersion of LDs in adipocytes stimulated with catecholamine.

  3. Phytic acid and myo-inositol support adipocyte differentiation and improve insulin sensitivity in 3T3-L1 cells.

    PubMed

    Kim, Jin Nam; Han, Sung Nim; Kim, Hye-Kyeong

    2014-08-01

    Phytic acid, also known as myo-inositol hexaphosphate, has been shown to lower blood glucose levels and to improve insulin sensitivity in rodents. We investigated the effects of phytic acid and myo-inositol on differentiation, insulin-stimulated glucose uptake, and lipolysis of adipocytes to test the hypothesis that the antidiabetic properties of phytic acid and myo-inositol are mediated directly through adipocytes. 3T3-L1 cells were treated with 10, 50, or 200 μmol/L of phytic acid or myo-inositol. Oil Red O staining and an intracellular triacylglycerol assay were used to determine lipid accumulation during adipocyte differentiation. Immunoblotting and real-time polymerase chain reaction (PCR) were performed to evaluate expression of transcription factors, a target protein, and insulin signaling molecules. Phytic acid and myo-inositol exposures increased lipid accumulation in a dose-dependent manner (P < .01). The expression of key transcription factors associated with adipocyte differentiation, such as peroxisome proliferator-activated receptor γ (PPARγ) and sterol regulatory element-binding protein 1c, and the expression of fatty acid synthase increased upon treatments with phytic acid and myo-inositol (P < .05). Insulin-stimulated glucose uptake in mature adipocytes increased with phytic acid and myo-inositol treatments (P < .01). In addition, mRNA levels of insulin receptor substrate 1 (IRS1), mRNA levels of glucose transporter 4, and phosphorylation of tyrosine in IRS1 increased upon phytic acid and myo-inositol treatments. In fully differentiated adipocytes, phytic acid and myo-inositol reduced basal lipolysis dose dependently (P < .01). These results suggest that phytic acid and myo-inositol increase insulin sensitivity in adipocytes by increasing lipid storage capacity, improving glucose uptake, and inhibiting lipolysis.

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

    PubMed Central

    Oliveira, Marcus F.; Burritt, Nathan; Corkey, Barbara E.

    2016-01-01

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

  5. Interacting Effects of TSH and Insulin on Human Differentiated Adipocytes.

    PubMed

    Felske, D; Gagnon, A; Sorisky, A

    2015-08-01

    Subclinical hypothyroidism, characterized by an isolated rise in TSH serum levels with normal thyroid function, is a pro-inflammatory state associated with insulin resistance. Adipocytes express TSH receptors, but it is not known if TSH can directly inhibit insulin signaling. Using primary human differentiated adipocytes, we examined the effects of TSH on insulin-stimulated Akt phosphorylation, and whether conventional PKC (cPKC) were involved. The effect of insulin on TSH-stimulated lipolysis was also investigated. TSH inhibited insulin-stimulated Akt phosphorylation in adipocytes by 54%. TSH activated cPKC, and Gö6976, a PKCα and -β1 inhibitor, prevented the inhibitory effect of TSH on the insulin response. Insulin reduced the ability of TSH to activate cPKC and to stimulate lipolysis.Our data reveal novel interactions between TSH and insulin. TSH inhibits insulin-stimulated Akt signaling in a cPKC-dependent fashion, whereas insulin blocks TSH-stimulated cPKC activity and lipolysis. TSH and insulin act on differentiated human adipocytes to modulate their respective intracellular signals.

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

    SciTech Connect

    Luo Weijun; Shitaye, Hailu; Friedman, Michael; Bennett, Christina N.; Miller, Joshua; MacDougald, Ormond A.; Hankenson, Kurt D.

    2008-11-01

    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 {mu}g/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.

  7. TMEM120A and B: Nuclear Envelope Transmembrane Proteins Important for Adipocyte Differentiation

    PubMed Central

    Batrakou, Dzmitry G.; de las Heras, Jose I.; Czapiewski, Rafal; Mouras, Rabah; Schirmer, Eric C.

    2015-01-01

    Recent work indicates that the nuclear envelope is a major signaling node for the cell that can influence tissue differentiation processes. Here we present two nuclear envelope trans-membrane proteins TMEM120A and TMEM120B that are paralogs encoded by the Tmem120A and Tmem120B genes. The TMEM120 proteins are expressed preferentially in fat and both are induced during 3T3-L1 adipocyte differentiation. Knockdown of one or the other protein altered expression of several genes required for adipocyte differentiation, Gata3, Fasn, Glut4, while knockdown of both together additionally affected Pparg and Adipoq. The double knockdown also increased the strength of effects, reducing for example Glut4 levels by 95% compared to control 3T3-L1 cells upon pharmacologically induced differentiation. Accordingly, TMEM120A and B knockdown individually and together impacted on adipocyte differentiation/metabolism as measured by lipid accumulation through binding of Oil Red O and coherent anti-Stokes Raman scattering microscopy (CARS). The nuclear envelope is linked to several lipodystrophies through mutations in lamin A; however, lamin A is widely expressed. Thus it is possible that the TMEM120A and B fat-specific nuclear envelope transmembrane proteins may play a contributory role in the tissue-specific pathology of this disorder or in the wider problem of obesity. PMID:26024229

  8. Coupling growth arrest and adipocyte differentiation.

    PubMed Central

    Ailhaud, G; Dani, C; Amri, E Z; Djian, P; Vannier, C; Doglio, A; Forest, C; Gaillard, D; Négrel, R; Grimaldi, P

    1989-01-01

    The complete differentiation program of preadipose cells can be divided into early and late events. The expression of early markers takes place at growth arrest (G1/S boundary), whereas that of late markers, leading to terminal differentiation, takes place after a limited number of mitoses of early marker-containing cells. Only terminal differentiation requires the presence of growth hormone and triiodothyronine and results in the formation of triacylglycerol-filled, nondividing cells. The events of adipose cell differentiation which take place in vitro allow a better understanding of the development of adipose tissue in vivo. Images FIGURE 1. FIGURE 3. FIGURE 5. PMID:2647477

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

    PubMed

    Pham, Tho X; Lee, Ji-Young

    2016-06-01

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

  10. Aculeatin, a coumarin derived from Toddalia asiatica (L.) Lam., enhances differentiation and lipolysis of 3T3-L1 adipocytes

    SciTech Connect

    Watanabe, Akio; Kato, Tsuyoshi; Ito, Yusuke; Yoshida, Izumi; Harada, Teppei; Mishima, Takashi; Fujita, Kazuhiro; Watai, Masatoshi; Nakagawa, Kiyotaka; Miyazawa, Teruo

    2014-10-31

    Highlights: • Aculeatin promoted adipocyte differentiation. • Aculeatin improved glucose uptake. • Aculeatin enhanced adipocyte lipolysis. - Abstract: Toddalia asiatica (L.) Lam. (T. asiatica) has been utilized traditionally for medicinal purposes such as the treatment of diabetes. Currently, the extract is considered to be a good source of anti-diabetic agents, but the active compounds have yet to be identified. In this study, we investigated the effects of fractionated T. asiatica extracts on the differentiation of 3T3-L1 preadipocytes and identified aculeatin as a potential active agent. When 3T3-L1 preadipocytes were treated with aculeatin isolated from T. asiatica in the presence of insulin, aculeatin increased cellular triglyceride levels and glycerol-3-phosphate dehydrogenase activity. This indicated that aculeatin could enhance the differentiation of preadipocytes into adipocytes. Further analyses using a DNA microarray and real-time quantitative reverse-transcription PCR showed an increase in the expression of peroxisome proliferator-activated receptor-γ target genes (Pparg, Ap2, Cd36, Glut4 and Adipoq) by aculeatin, suggesting that aculeatin enhances the differentiation of 3T3-L1 cells by modulating the expression of genes critical for adipogenesis. Interestingly, after treatment of differentiated adipocytes with aculeatin, glucose uptake and lipolysis were enhanced. Overall, our results suggested that aculeatin is an active compound in T. asiatica for enhancing both differentiation and lipolysis of adipocytes, which are useful for the treatment of lipid abnormalities as well as diabetes.

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

    PubMed

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

    2016-02-19

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

  12. Sulforaphane induces adipocyte browning and promotes glucose and lipid utilization

    PubMed Central

    Zhang, Hui Q.; Chen, Shi Y.; Wang, An S.; Yao, An J.; Fu, Jian F.; Zhao, Jin S.; Chen, Fen; Zou, Zu Q.; Shan, Yu J.; Bao, Yong P.

    2016-01-01

    1 Scope Obesity is closely related to the imbalance of white adipose tissue storing excess calories, and brown adipose tissue dissipating energy to produce heat in mammals. Recent studies revealed that acquisition of brown characteristics by white adipocytes, termed “browning,” may positively contribute to cellular bioenergetics and metabolism homeostasis. The goal was to investigate the putative effects of natural antioxidant sulforaphane (1‐isothiocyanate‐4‐methyl‐sulfonyl butane; SFN) on browning of white adipocytes. 2 Methods and results 3T3‐L1 mature white adipocytes were treated with SFN for 48 h, and then the mitochondrial content, function, and energy utilization were assessed. SFN was found to induce 3T3‐L1 adipocytes browning based on the increased mitochondrial content and activity of respiratory chain enzymes, whereas the mechanism involved the upregulation of nuclear factor E2‐related factor 2/sirtuin1/peroxisome proliferator activated receptor gamma coactivator 1 alpha signaling. SFN enhanced uncoupling protein 1 expression, a marker for brown adipocyte, leading to the decrease in cellular ATP. SFN also enhanced glucose uptake and oxidative utilization, lipolysis, and fatty acid oxidation in 3T3‐L1 adipocytes. 3 Conclusion SFN‐induced browning of white adipocytes enhanced the utilization of cellular fuel, and application of SFN is a promising strategy to combat obesity and obesity‐related metabolic disorder. PMID:27218607

  13. ATF3 represses PPARγ expression and inhibits adipocyte differentiation

    SciTech Connect

    Jang, Min-Kyung; Jung, Myeong Ho

    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

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

    PubMed Central

    2012-01-01

    Background Obesity is known to be associated with higher risks of cardiovascular disease, metabolic syndrome, and diabetes mellitus. Thyroid-stimulating hormone (TSHR) is the receptor for thyroid-stimulating hormone (TSH, or thyrotropin), the key regulator of thyroid functions. The expression of TSHR, once considered to be limited to thyrocytes, has been so far detected in many extrathyroidal tissues including liver and fat. Previous studies have shown that TSHR expression is upregulated when preadipocytes differentiate into mature adipocytes, suggestive of a possible role of TSHR in adipogenesis. However, it remains unclear whether TSHR expression in adipocytes is implicated in the pathogenesis of obesity. Methods In the present study, TSHR expression in adipose tissues from both mice and human was analyzed, and its association with obesity was evaluated. Results We here showed that TSHR expression was increased at both mRNA and protein levels when 3T3-L1 preadipocytes were induced to differentiate. Knockdown of TSHR blocked the adipocyte differentiation of 3T3-L1 preadipocytes as evaluated by Oil-red-O staining for lipid accumulation and by RT-PCR analyses of PPAR-γ and ALBP mRNA expression. We generated obesity mice (C57/BL6) by high-fat diet feeding and found that the TSHR protein expression in visceral adipose tissues from obesity mice was significantly higher in comparison with the non-obesity control mice (P < 0.05). Finally, the TSHR expression in adipose tissues was determined in 120 patients. The results showed that TSHR expression in subcutaneous adipose tissue is correlated with BMI (body mass index). Conclusion Taken together, these results suggested that TSHR is an important regulator of adipocyte differentiation. Dysregulated expression of TSHR in adipose tissues is associated with obesity, which may involve a mechanism of excess adipogenesis. PMID:22289392

  15. Fenretinide mediated retinoic acid receptor signalling and inhibition of ceramide biosynthesis regulates adipogenesis, lipid accumulation, mitochondrial function and nutrient stress signalling in adipocytes and adipose tissue

    PubMed Central

    Mcilroy, George D.; Tammireddy, Seshu R.; Maskrey, Benjamin H.; Grant, Louise; Doherty, Mary K.; Watson, David G.; Delibegović, Mirela; Whitfield, Phillip D.; Mody, Nimesh

    2016-01-01

    Fenretinide (FEN) is a synthetic retinoid that inhibits obesity and insulin resistance in high-fat diet (HFD)-fed mice and completely prevents 3T3-L1 pre-adipocyte differentiation. The aim of this study was to determine the mechanism(s) of FEN action in 3T3-L1 adipocytes and in mice. We used the 3T3-L1 model of adipogenesis, fully differentiated 3T3-L1 adipocytes and adipose tissue from HFD-induced obese mice to investigate the mechanisms of FEN action. We measured expression of adipogenic and retinoid genes by qPCR and activation of nutrient-signalling pathways by western blotting. Global lipid and metabolite analysis was performed and specific ceramide lipid species measured by liquid chromatography-mass spectrometry. We provide direct evidence that FEN inhibits 3T3-L1 adipogenesis via RA-receptor (RAR)-dependent signaling. However, RARα antagonism did not prevent FEN-induced decreases in lipid levels in mature 3T3-L1 adipocytes, suggesting an RAR-independent mechanism. Lipidomics analysis revealed that FEN increased dihydroceramide lipid species 5- to 16-fold in adipocytes, indicating an inhibition of the final step of ceramide biosynthesis. A similar blockade in adipose tissue from FEN-treated obese mice was associated with a complete normalisation of impaired mitochondrial β-oxidation and tricarboxylic acid cycle flux. The FEN catabolite, 4-oxo-N-(4-hydroxyphenyl)retinamide (4-OXO), also decreased lipid accumulation without affecting adipogenesis. FEN and 4-OXO (but not RA) treatment additionally led to the activation of p38-MAPK, peIF2α and autophagy markers in adipocytes. Overall our data reveals FEN utilises both RAR-dependent and -independent pathways to regulate adipocyte biology, both of which may be required for FEN to prevent obesity and insulin resistance in vivo. PMID:26592777

  16. The lipid sensor GPR120 promotes brown fat activation and FGF21 release from adipocytes

    PubMed Central

    Quesada-López, Tania; Cereijo, Rubén; Turatsinze, Jean-Valery; Planavila, Anna; Cairó, Montserrat; Gavaldà-Navarro, Aleix; Peyrou, Marion; Moure, Ricardo; Iglesias, Roser; Giralt, Marta; Eizirik, Decio L.; Villarroya, Francesc

    2016-01-01

    The thermogenic activity of brown adipose tissue (BAT) and browning of white adipose tissue are important components of energy expenditure. Here we show that GPR120, a receptor for polyunsaturated fatty acids, promotes brown fat activation. Using RNA-seq to analyse mouse BAT transcriptome, we find that the gene encoding GPR120 is induced by thermogenic activation. We further show that GPR120 activation induces BAT activity and promotes the browning of white fat in mice, whereas GRP120-null mice show impaired cold-induced browning. Omega-3 polyunsaturated fatty acids induce brown and beige adipocyte differentiation and thermogenic activation, and these effects require GPR120. GPR120 activation induces the release of fibroblast growth factor-21 (FGF21) by brown and beige adipocytes, and increases blood FGF21 levels. The effects of GPR120 activation on BAT activation and browning are impaired in FGF21-null mice and cells. Thus, the lipid sensor GPR120 activates brown fat via a mechanism that involves induction of FGF21. PMID:27853148

  17. Transcriptomic Analyses of Adipocyte Differentiation From Human Mesenchymal Stromal-Cells (MSC).

    PubMed

    Casado-Díaz, Antonio; Anter, Jaouad; Müller, Sören; Winter, Peter; Quesada-Gómez, José Manuel; Dorado, Gabriel

    2017-04-01

    Adipogenesis is a physiological process required for fat-tissue development, mainly involved in regulating the organism energetic-state. Abnormal distribution-changes and dysfunctions in such tissue are associated to different pathologies. Adipocytes are generated from progenitor cells, via a complex differentiating process not yet well understood. Therefore, we investigated differential mRNA and miRNA expression patterns of human mesenchymal stromal-cells (MSC) induced and not induced to differentiate into adipocytes by next (second)-generation sequencing. A total of 2,866 differentially expressed genes (101 encoding miRNA) were identified, with 705 (46 encoding miRNA) being upregulated in adipogenesis. They were related to different pathways, including PPARG, lipid, carbohydrate and energy metabolism, redox, membrane-organelle biosynthesis, and endocrine system. Downregulated genes were related to extracellular matrix and cell migration, proliferation, and differentiation. Analyses of mRNA-miRNA interaction showed that repressed miRNA-encoding genes can act downregulating PPARG-related genes; mostly the PPARG activator (PPARGC1A). Induced miRNA-encoding genes regulate downregulated genes related to TGFB1. These results shed new light to understand adipose-tissue differentiation and physiology, increasing our knowledge about pathologies like obesity, type-2 diabetes and osteoporosis. J. Cell. Physiol. 232: 771-784, 2017. © 2016 Wiley Periodicals, Inc.

  18. Modest hypoxia significantly reduces triglyceride content and lipid droplet size in 3T3-L1 adipocytes

    SciTech Connect

    Hashimoto, Takeshi; Yokokawa, Takumi; Endo, Yuriko; Iwanaka, Nobumasa; Higashida, Kazuhiko; Taguchi, Sadayoshi

    2013-10-11

    Highlights: •Long-term hypoxia decreased the size of LDs and lipid storage in 3T3-L1 adipocytes. •Long-term hypoxia increased basal lipolysis in 3T3-L1 adipocytes. •Hypoxia decreased lipid-associated proteins in 3T3-L1 adipocytes. •Hypoxia decreased basal glucose uptake and lipogenic proteins in 3T3-L1 adipocytes. •Hypoxia-mediated lipogenesis may be an attractive therapeutic target against obesity. -- Abstract: Background: A previous study has demonstrated that endurance training under hypoxia results in a greater reduction in body fat mass compared to exercise under normoxia. However, the cellular and molecular mechanisms that underlie this hypoxia-mediated reduction in fat mass remain uncertain. Here, we examine the effects of modest hypoxia on adipocyte function. Methods: Differentiated 3T3-L1 adipocytes were incubated at 5% O{sub 2} for 1 week (long-term hypoxia, HL) or one day (short-term hypoxia, HS) and compared with a normoxia control (NC). Results: HL, but not HS, resulted in a significant reduction in lipid droplet size and triglyceride content (by 50%) compared to NC (p < 0.01). As estimated by glycerol release, isoproterenol-induced lipolysis was significantly lowered by hypoxia, whereas the release of free fatty acids under the basal condition was prominently enhanced with HL compared to NC or HS (p < 0.01). Lipolysis-associated proteins, such as perilipin 1 and hormone-sensitive lipase, were unchanged, whereas adipose triglyceride lipase and its activator protein CGI-58 were decreased with HL in comparison to NC. Interestingly, such lipogenic proteins as fatty acid synthase, lipin-1, and peroxisome proliferator-activated receptor gamma were decreased. Furthermore, the uptake of glucose, the major precursor of 3-glycerol phosphate for triglyceride synthesis, was significantly reduced in HL compared to NC or HS (p < 0.01). Conclusion: We conclude that hypoxia has a direct impact on reducing the triglyceride content and lipid droplet size via

  19. Stimulatory Effects of Cinnamon Extract (Cinnamomum cassia) during the Initiation Stage of 3T3-L1 Adipocyte Differentiation

    PubMed Central

    Lee, Sang Gil; Siaw, Joanna A.; Kang, Hye Won

    2016-01-01

    Cinnamon (Cinnamomum cassia) has an anti-diabetic effect by possibly increasing the lipid storage capacity of white adipocytes; however, this effect remains controversial. The aim of this study was to examine which stage of adipogenesis is critical for the stimulatory effect of cinnamon in adipogenesis using 3T3-L1 cells. Cells were treated with cinnamon extract during three different stages of adipogenesis. We found that genes related to adipogenesis and lipogenesis were enhanced when cinnamon extract was administered during the initiation stage of differentiation but not when administered during the preadipocyte and post stages of differentiation. At the same time, genes that were involved in the regulation of fatty acid oxidation were unexpectedly upregulated. Taken together, cinnamon may boost lipid storage in white adipocytes and increase the fatty acid oxidation capacity throughout the initiation stage of differentiation, which may be beneficial for the prevention of obesity-induced type II diabetes. PMID:28231178

  20. Effects of Rilpivirine on Human Adipocyte Differentiation, Gene Expression, and Release of Adipokines and Cytokines

    PubMed Central

    Díaz-Delfín, Julieta; Domingo, Pere; Mateo, Maria Gracia; Gutierrez, Maria del Mar; Domingo, Joan Carles; Giralt, Marta

    2012-01-01

    Rilpivirine is a nonnucleoside reverse transcriptase inhibitor (NNRTI) recently developed as a drug of choice for initial antiretroviral treatment of HIV-1 infection. Disturbances in lipid metabolism and, ultimately, in adipose tissue distribution and function are common concerns as secondary effects of antiretroviral treatment. Efavirenz, the most commonly used NNRTI, causes mild dyslipidemic effects in patients and strongly impaired adipocyte differentiation in vitro. In this study, we provide the first demonstration of the effects of rilpivirine on human adipocyte differentiation, gene expression, and release of regulatory proteins (adipokines and cytokines) and compare them with those caused by efavirenz. Rilpivirine caused a repression of adipocyte differentiation that was associated with impaired expression of the master adipogenesis regulators peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT enhancer binding protein alpha (C/EBPα), and sterol regulatory element binding transcription factor 1 (SREBP-1) and their target genes encoding lipoprotein lipase and the adipokines leptin and adiponectin. Rilpivirine also repressed adiponectin release by adipocytes, but only at high concentrations, and did not alter leptin release. Rilpivirine induced the release of proinflammatory cytokines (interleukin-6 and -8, monocyte chemoattractant protein 1 [MCP-1], plasminogen activator inhibitor type 1 [PAI-1]) only at very high concentrations (10 μM). A comparison of the effects of rilpivirine and efavirenz at the same concentration (4 μM) or even at lower concentrations of efavirenz (2 μM) showed that rilpivirine-induced impairment of adipogenesis and induction of proinflammatory cytokine expression and release were systematically milder than those of efavirenz. It is concluded that rilpivirine causes an antiadipogenic and proinflammatory response pattern, but only at high concentrations, whereas efavirenz causes similar effects at lower concentrations

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

    PubMed

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

    2010-10-01

    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 characterised small adipocytes from epididymal adipose tissue of Zucker Obese (ZO) and Lean (ZL) rats. Rat epididymal fat pads were removed and adipocytes isolated by collagenase digestion. Small adipocytes were separated by sequential filtration through nylon meshes. Adipocytes were fixed in osmium tetroxide for cell size distribution analysis via Beckman Coulter Multisizer. Quantitative real-time PCR for cell differentiation and inflammatory genes was performed. Small adipocytes represented a markedly greater percentage of the total adipocyte population in ZO than ZL rats (58±4% vs. 12±3%, p<0.001). In ZO rats, small as compared with total adipocytes had 4-fold decreased adiponectin, and 4-fold increased visfatin and IL-6 levels. Comparison of small adipocytes in ZO versus ZL rats revealed 3-fold decreased adiponectin and PPARγ levels, and 2.5-fold increased IL-6. In conclusion, ZO rat adipose tissue harbours a large proportion of small adipocytes that manifest impaired cell differentiation and pro-inflammatory activity, two mechanisms by which small adipocytes may contribute to insulin resistance.

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

    PubMed

    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.

  3. Impact of elvitegravir on human adipocytes: Alterations in differentiation, gene expression and release of adipokines and cytokines.

    PubMed

    Moure, Ricardo; Domingo, Pere; Gallego-Escuredo, José M; Villarroya, Joan; Gutierrez, Maria Del Mar; Mateo, Maria G; Domingo, Joan C; Giralt, Marta; Villarroya, Francesc

    2016-08-01

    Elvitegravir is a recently developed integrase inhibitor used for antiretroviral treatment of HIV infection. Secondary effects, including disturbances in lipid metabolism and, ultimately, in adipose tissue distribution and function, are common concerns associated with antiretroviral treatments. Here, we provide the first study of the effects of elvitegravir (in comparison with efavirenz, a non-nucleoside analog inhibitor of reverse transcriptase; and raltegravir, another integrase inhibitor) on human adipocyte differentiation, gene expression and secretion of adipokines and cytokines. Elvitegravir impaired adipogenesis and adipocyte metabolism in human SGBS adipocytes in a concentration-dependent manner (delaying acquisition of adipocyte morphology and reducing the expression of adipogenesis marker genes such as PPARγ, glucose transporter GLUT4, lipoprotein lipase, and the adipokines adiponectin and leptin). Compared with efavirenz, the effects of elvitegravir were similar but tended to occur at higher concentrations than those elicited by efavirenz, or were somewhat less intense than those caused by efavirenz at similar concentration. Elvitegravir tended to cause a more moderate induction of pro-inflammatory cytokines than efavirenz. Efavirenz induced a marked concentration-dependent increase in interleukin-8 expression and release whereas elvitregravir had little effect. Raltegravir had totally neutral actions of adipogenesis, adipocyte metabolism-related gene expression and release of adipokines and cytokines. In conclusion, elvitegravir alters adipocyte differentiation and function and promotes induction of pro-inflammatory cytokines similarly to efavirenz, but several effects were less intense. Further assessment of lipid metabolism and adipose tissue function in patients administered elvitegravir-based regimes is advisable considering that totally neutral effects of elvitegravir on lipid homeostasis cannot be anticipated from the current study in vitro.

  4. C-terminus of HSC70-Interacting Protein (CHIP) Inhibits Adipocyte Differentiation via Ubiquitin- and Proteasome-Mediated Degradation of PPARγ

    PubMed Central

    Kim, Jung-Hoon; Shin, Soyeon; Seo, Jinho; Lee, Eun-Woo; Jeong, Manhyung; Lee, Min-sik; Han, Hyun-Ji; Song, Jaewhan

    2017-01-01

    PPARγ (Peroxisome proliferator-activated receptor γ) is a nuclear receptor involved in lipid homeostasis and related metabolic diseases. Acting as a transcription factor, PPARγ is a master regulator for adipocyte differentiation. Here, we reveal that CHIP (C-terminus of HSC70-interacting protein) suppresses adipocyte differentiation by functioning as an E3 ligase of PPARγ. CHIP directly binds to and induces ubiquitylation of the PPARγ protein, leading to proteasome-dependent degradation. Stable overexpression or knockdown of CHIP inhibited or promoted adipogenesis, respectively, in 3T3-L1 cells. On the other hand, a CHIP mutant defective in E3 ligase could neither regulate PPARγ protein levels nor suppress adipogenesis, indicating the importance of CHIP-mediated ubiquitylation of PPARγ in adipocyte differentiation. Lastly, a CHIP null embryo fibroblast exhibited augmented adipocyte differentiation with increases in PPARγ and its target protein levels. In conclusion, CHIP acts as an E3 ligase of PPARγ, suppressing PPARγ-mediated adipogenesis. PMID:28059128

  5. Impacts of Alternative Splicing Events on the Differentiation of Adipocytes

    PubMed Central

    Lin, Jung-Chun

    2015-01-01

    Alternative splicing was found to be a common phenomenon after the advent of whole transcriptome analyses or next generation sequencing. Over 90% of human genes were demonstrated to undergo at least one alternative splicing event. Alternative splicing is an effective mechanism to spatiotemporally expand protein diversity, which influences the cell fate and tissue development. The first focus of this review is to highlight recent studies, which demonstrated effects of alternative splicing on the differentiation of adipocytes. Moreover, use of evolving high-throughput approaches, such as transcriptome analyses (RNA sequencing), to profile adipogenic transcriptomes, is also addressed. PMID:26389882

  6. Autocrine/paracrine function of globular adiponectin: inhibition of lipid metabolism and inflammatory response in 3T3-L1 adipocytes.

    PubMed

    Lazra, Yulia; Falach, Alona; Frenkel, Lital; Rozenberg, Konstantin; Sampson, Sanford; Rosenzweig, Tovit

    2015-05-01

    Adiponectin is an adipose-derived hormone, with beneficial effects on insulin sensitivity and inflammation. The aim of this study was to clarify the autocrine/paracrine effects of globular adiponectin (gAd) administrated during differentiation on the function of the mature adipocytes. Experiments were performed on 3T3-L1 preadipocytes treated with gAd (10 nM), starting at an early stage of differentiation. gAd treatment during differentiation was without effect on mRNA expression of adiponectin and AdipoR2, but increased AdipoR1 expression. PPARgamma, perillipin and FABP4 mRNA expressions were lower in gAd-treated adipocytes, accompanied by a reduction in lipid accumulation. While mRNA expression of HSL was not affected by gAd compared to untreated adipocytes, both ATGL and FAS were reduced, indicating that gAd regulates both lipolysis and lipogenesis. PPARα, ACOX2 and UCPs mRNA expressions were not affected by gAd, indicating that the reduction in lipid content is not attributed to an increase in fatty-acid oxidation. In accord with the lower PPARγ expression, there was reduced Glut4 mRNA expression; however, insulin-induced PKB phosphorylation was enhanced by gAd, and glucose uptake was not altered. To investigate the effect of gAd on LPS-induced inflammatory response, cells were treated with gAd either during differentiation or 24 h before induction of inflammation in differentiated adipocytes. LPS-induced inflammatory response, as indicated by increase in IL6 and MCP-1 mRNA expression. gAd given through differentiation was much more effective in abrogating LPS-dependent cytokines production than gAd given to the mature adipocyte. In conclusion, elevated gAd at differentiation of 3T3-L1 cells leads to reduced lipid content, reduced lipid metabolism and high resistance to inflammation.

  7. Automated Image Processing for Spatially Resolved Analysis of Lipid Droplets in Cultured 3T3-L1 Adipocytes

    PubMed Central

    Sims, James Kenneth; Rohr, Brian; Miller, Eric

    2015-01-01

    Cellular hypertrophy of adipose tissue underlies many of the proposed proinflammatory mechanisms for obesity-related diseases. Adipose hypertrophy results from an accumulation of esterified lipids (triglycerides) into membrane-enclosed intracellular lipid droplets (LDs). The coupling between adipocyte metabolism and LD morphology could be exploited to investigate biochemical regulation of lipid pathways by monitoring the dynamics of LDs. This article describes an image processing method to identify LDs based on several distinctive optical and morphological characteristics of these cellular bodies as they appear under bright-field. The algorithm was developed against images of 3T3-L1 preadipocyte cultures induced to differentiate into adipocytes. We show that the calculated lipid volumes are in excellent agreement with enzymatic assay data on total intracellular triglyceride content. We also demonstrate that the image processing method can efficiently characterize the highly heterogeneous spatial distribution of LDs in a culture by showing that differentiation occurs in distinct clusters separated by regions of nearly undifferentiated cells. Prospectively, the LD detection method described in this work could be applied to time-lapse data collected with simple visible light microscopy equipment to quantitatively investigate LD dynamics. PMID:25390760

  8. Unexpected blockade of adipocyte differentiation by K-7174: Implication for endoplasmic reticulum stress

    SciTech Connect

    Shimada, Tsuyoshi; Hiramatsu, Nobuhiko; Okamura, Maro; Hayakawa, Kunihiro; Kasai, Ayumi; Yao, Jian; Kitamura, Masanori

    2007-11-16

    Preadipocytes constitutively express GATA-2 and GATA-3 that are required to halt the cells at the undifferentiated stage. However, we unexpectedly found that K-7174, a GATA-specific inhibitor, did not induce but rather inhibited differentiation of 3T3-L1 preadipocytes. It was associated with lack of lipid accumulation, blunted expression of adipocyte markers including adiponectin and peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}), and sustained expression of a preadipocyte marker monocyte chemoattractant protein 1 (MCP-1). Subsequent experiments revealed that K-7174 had the potential to induce endoplasmic reticulum (ER) stress evidenced by induction of GRP78 and CHOP. Other inducers of ER stress completely reproduced the effects of K-7174 including suppression of lipid accumulation, blockade of induction of adiponection and PPAR{gamma} and maintenance of MCP-1 expression. These results indicated a possibility that ER stress suppresses adipocyte differentiation and that GATA inhibitor K-7174 has the potential for interfering with adipogenesis through induction of ER stress.

  9. Small‑molecule COH-SR4 inhibits adipocyte differentiation via AMPK activation.

    PubMed

    Figarola, James L; Rahbar, Samuel

    2013-05-01

    Obesity is a chronic metabolic disorder caused by an imbalance between energy intake and expenditure. It is one of the principal causative factors involved in the development of metabolic syndrome and cancer. Inhibition of adipocyte differentiation has often been a target of anti-obesity strategies since obesity is caused not only by hypertrophy but also by adipocyte hyperplasia. In this study, we investigated the effects of COH-SR4, a novel compound with anticancer properties, on the adipogenesis in 3T3-L1 cells. Treatment with COH-SR4 significantly inhibited adipocyte differentiation in a dose-dependent manner. This inhibitory effect mainly occurred at the early phase of differentiation through inhibition of mitotic clonal expansion and cell cycle arrest at the G1/S phase transition. In differentiating adipocytes, COH-SR4 significantly reduced intracellular lipid accumulation and downregulated the expression of key adipogenesis-related transcription factors and lipogenic proteins. COH-SR4 exhibited no cytotoxic effects in 3T3-L1 cells, but indirectly activated AMP-activated protein kinase (AMPK). AMPK activation by COH-SR4 also resulted in the phosphorylation of raptor and tuberous sclerosis protein 2 (TSC2), two proteins involved in the mammalian target of rapamycin (mTOR) signaling pathways. Additionally, COH-SR4 decreased the phosphorylation of p70 kDa ribosomal protein S6 kinase (S6K) and initiation factor 4E (eIF4E) binding protein 1 (4EB‑P1), two downstream effectors of mTOR that regulate protein synthesis. Interestingly, knockdown of AMPKα1/α2 prevented the ability of COH-SR4 to inhibit cell cycle arrest and overall adipogenesis and lipid accumulation in the differentiating 3T3-L1 cells. Taken together, these results suggest that COH-SR4 inhibits 3T3-L1 adipogenesis via AMPK activation. COH-SR4 may be a promising compound for the treatment of obesity and related metabolic disorders.

  10. Effects of Tithonia diversifolia (Hemsl.) A. Gray Extract on Adipocyte Differentiation of Human Mesenchymal Stem Cells

    PubMed Central

    Di Giacomo, Claudia; Vanella, Luca; Sorrenti, Valeria; Santangelo, Rosa; Barbagallo, Ignazio; Calabrese, Giovanna; Genovese, Carlo; Mastrojeni, Silvana; Ragusa, Salvatore; Acquaviva, Rosaria

    2015-01-01

    Tithonia diversifolia (Hemsl.) A. Gray (Asteraceae) is widely used in traditional medicine. There is increasing interest on the in vivo protective effects of natural compounds contained in plants against oxidative damage caused from reactive oxygen species. In the present study the total phenolic and flavonoid contents of aqueous, methanol and dichloromethane extracts of leaves of Tithonia diversifolia (Hemsl.) A. Gray were determined; furthermore, free radical scavenging capacity of each extract and the ability of these extracts to inhibit in vitro plasma lipid peroxidation were also evaluated. Since oxidative stress may be involved in trasformation of pre-adipocytes into adipocytes, to test the hypothesis that Tithonia extract may also affect adipocyte differentiation, human mesenchymal stem cell cultures were treated with Tithonia diversifolia aqueous extract and cell viability, free radical levels, Oil-Red O staining and western bolt analysis for heme oxygenase and 5'-adenosine monophoshate-activated protein kinase were carried out. Results obtained in the present study provide evidence that Tithonia diversifolia (Hemsl.) A. Gray exhibits interesting health promoting properties, resulting both from its free radical scavenger capacity and also by induction of protective cellular systems involved in cellular stress defenses and in adipogenesis of mesenchymal cells. PMID:25848759

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

    PubMed Central

    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 storage and release in the adipocyte. However, in the absence of PKA stimulation (basal state), the lipases (ATGL and HSL) are located mainly in the cytoplasm, and their contribution to basal rates of lipolysis and influence on LD size are poorly understood. In this study, we utilize an adenoviral system to knockdown or overexpress ATGL and HSL in an engineered model system of adipocytes in the presence or absence of Peri A. We are able to demonstrate in our experimental model system, that in the basal state, LD size, triglyceride storage, and fatty acid release are mainly influenced by expression of ATGL. These results demonstrate for the first time the relative contributions of ATGL, HSL, and Peri A on determination of LD size in the absence of PKA-stimulation. PMID:18980248

  12. Fluorescence lifetime imaging of lipids during 3T3-L1 cell differentiation

    NASA Astrophysics Data System (ADS)

    Song, Young Sik; Won, Young Jae; Lee, Sang-Hak; Kim, Dug Young

    2014-03-01

    Obesity is becoming a big health problem in these days. Since increased body weight is due to increased number and size of the triglyceride-storing adipocytes, many researchers are working on differentiation conditions and processes of adipocytes. Adipocytes also work as regulators of whole-body energy homeostasis by secreting several proteins that regulate processes as diverse as haemostasis, blood pressure, immune function, angiogenesis and energy balance. 3T3-L1 cells are widely used cell line for studying adipogenesis because it can differentiate into an adipocyte-like phenotype under appropriate conditions. In this paper, we propose an effective fluorescence lifetime imaging technique which can easily distinguish lipids in membrane and those in lipid droplets. Nile red dyes are attached to lipids in 3T3-L1 cells. Fluorescence lifetime images were taken for 2 week during differentiation procedure of 3T3-L1 cells into adipocytes. We used 488 nm pulsed laser with 5MHz repetition rate and emission wavelength is 520 nm of Nile Red fluorescent dye. Results clearly show that the lifetime of Nile red in lipid droplets are smaller than those in cell membrane. Our results suggest that fluorescence lifetime imaging can be a very powerful tool to monitor lipid droplet formation in adipocytes from 3T3-L1 cells.

  13. Sanggenol F exerts anti-diabetic effects via promoting adipocyte differentiation and modifying adipokines expression.

    PubMed

    Zhu, Jing-Jie; Huang, Jun-Shang; Wang, Ting; Ji, Jun; Hou, Ai-Jun; Wang, He-Yao

    2016-12-21

    Adipose tissue is not only a lipid storage site, but also a well-known endocrine organ. Dysfunction of adipose tissue is associated with irregular lipid metabolism, ectopic lipid accumulation and insulin resistance. It is proposed that modulating on adipose tissue is a reasonable way to ameliorate glucose and lipid metabolism. (±)-sanggenol F (SGF, purity >98.5%) was synthesized as a racemic mixture of natural (+)-sanggenol F. In this study, SGF was found to promote adipocyte differentiation, enhance insulin sensitivity, and upregulate beneficial adipokines expression in 3T3-L1 cells. Furthermore, in vivo study showed that treatment with SGF for 4 weeks improved glucose metabolism, by decreasing fasting blood glucose and enhancing insulin sensitivity. It also improved lipid metabolism, with reduced serum lipid level and ameliorated hepatic steatosis in db/db mice. During the process of target finding, we found that SGF had multiple activities of protein tyrosine phosphatase 1B inhibition, peroxisome proliferator-activated receptor γ and peroxisome proliferator-activated receptor α agonism. These results showed the potential of SGF as a candidate for the therapy of type 2 diabetes.

  14. Increased lipid accumulation and adipogenic gene expression of adipocytes in 3D bioprinted nanocellulose scaffolds.

    PubMed

    Henriksson, I; Gatenholm, P; Hägg, D A

    2017-02-21

    Compared to standard 2D culture systems, new methods for 3D cell culture of adipocytes could provide more physiologically accurate data and a deeper understanding of metabolic diseases such as diabetes. By resuspending living cells in a bioink of nanocellulose and hyaluronic acid, we were able to print 3D scaffolds with uniform cell distribution. After one week in culture, cell viability was 95%, and after two weeks the cells displayed a more mature phenotype with larger lipid droplets than standard 2D cultured cells. Unlike cells in 2D culture, the 3D bioprinted cells did not detach upon lipid accumulation. After two weeks, the gene expression of the adipogenic marker genes PPARγ and FABP4 was increased 2.0- and 2.2-fold, respectively, for cells in 3D bioprinted constructs compared with 2D cultured cells. Our 3D bioprinted culture system produces better adipogenic differentiation of mesenchymal stem cells and a more mature cell phenotype than conventional 2D culture systems.

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

    SciTech Connect

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

    2006-11-01

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

  16. Effect of growth hormone on the differentiation of bovine preadipocytes into adipocytes and the role of the signal transducer and activator of transcription 5b.

    PubMed

    Zhao, L; Wang, A; Corl, B A; Jiang, H

    2014-05-01

    We evaluated the effect of GH on the differentiation of primary bovine preadipocytes into adipocytes. Bovine preadipocytes, derived from adipose tissue explants, were induced to differentiate into adipocytes in the presence or absence of recombinant bovine GH. The differentiation status of adipocytes was assessed by Oil Red O staining and by measuring the activity of glycerol-3-phosphate dehydrogenase (G3PDH) and the rate of acetate incorporation. Fewer preadipocytes became adipocytes in the presence of GH than in the absence of GH; adipocytes formed in the presence of GH had lower G3PDH activity and lower rate of acetate incorporation than those formed without GH treatment (P < 0.05). These data suggest an inhibitory effect of GH on the differentiation of bovine preadipocytes into adipocytes. Growth hormone decreased the expression of C/EBPα and PPARγ mRNA in bovine adipocytes (P < 0.05). Because C/EBPα and PPARγ are the master regulators of adipocyte differentiation, this data suggests that GH might inhibit the differentiation of bovine preadipocytes into adipocytes by inhibiting the expression of C/EBPα and/or PPARγ. Because the signal transducer and activator of transcription 5 (STAT5) is a major component of signaling from the GH receptor, we next determined the potential role of STAT5 in GH inhibition of bovine adipocyte differentiation. Overexpression of a constitutively active form of STAT5b (STAT5bCA) in bovine preadipocytes through adenoviral transduction mimicked the effects of GH on the formation of lipid-containing adipocytes, G3PDH activity, and acetate incorporation rate. Overexpression of STAT5bCA was associated with decreased expression of C/EBPα mRNA (P < 0.05) but not that of PPARγ mRNA in bovine adipocytes. These results support a role of STAT5b in mediating GH inhibition of C/EBPα expression but not that of PPARγ expression in bovine preadipocytes. Overall, the present study suggests that GH may inhibit adipose growth in cattle in

  17. Lipid metabolism, adipocyte depot physiology and utilization of meat animals as experimental models for metabolic research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Meat animals are unique as experimental models for both lipid metabolism and adipocyte studies because of their direct economic value for animal production. This paper discusses the principles that regulate adipogenesis in major meat animals (beef cattle, dairy cattle, and pigs), the definition of a...

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

    NASA Astrophysics Data System (ADS)

    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. Differentiation of A31T6 proadipocytes to adipocytes: A flow cytometric analysis

    SciTech Connect

    Smyth, M.J.; Wharton, W. )

    1992-03-01

    A flow cytometric assay has been developed which provides precise, quantitative information on the accumulation of cytoplasmic triglycerides in individual A31T6 proadipocytes as they differentiate into adipocytes. The opportunity to measure multiple optical parameter on a cell-by-cell basis has enabled us to monitor phenotypic aspects of differentiation with a greater level of sensitivity than was previously possible. Using the fluorescent hydrophobic probe, Nile red, they have found that as a cell proceeds along the differentiation pathway, the gold fluorescence signal from the cell increases, reflecting the accumulation of cytoplasmic lipid droplets. They have determined (1) the presence of an undifferentiated population of cells whose existence is not detected by conventional phase microscopy, (2) that insulin is no required to drive differentiation in this system, (3) that exposure to a combination of insulin and dexamethasone results in a lower accumulation of lipid in a cell than does exposure to either agent alone, and (4) that A31T6 cells show the same response to differentiation-promoting agents whether applied at the time of plating or at confluence.

  20. Bisindoylmaleimide I suppresses adipocyte differentiation through stabilization of intracellular {beta}-catenin protein

    SciTech Connect

    Cho, Munju; Park, Seoyoung; Gwak, Jungsug; Kim, Dong-Eun; Yea, Sung Su; Shin, Jae-Gook; Oh, Sangtaek

    2008-02-29

    The Wnt/{beta}-catenin signaling pathway plays important roles in cell differentiation. Activation of this pathway, likely by Wnt-10b, has been shown to inhibit adipogenesis in cultured 3T3-L1 preadipocytes and mice. Here we revealed that bisindoylmaleimide I (BIM), which is widely used as a specific inhibitor of protein kinase C (PKC), inhibits adipocyte differentiation through activation of the Wnt/{beta}-catenin signaling pathway. BIM increased {beta}-catenin responsive transcription (CRT) and up-regulated intracellular {beta}-catenin levels in HEK293 cells and 3T3-L1 preadipocytes. BIM significantly decreased intracellular lipid accumulation and reduced expression of important adipocyte marker genes including peroxisome-proliferator-activated receptor {gamma} (PPAR{gamma}) and CAATT enhancer-binding protein {alpha} (C/EBP{alpha}) in 3T3-L1 preadipocytes. Taken together, our findings indicate that BIM inhibits adipogenesis by increasing the stability of {beta}-catenin protein in 3T3-L1 preadipocyte cells.

  1. Pycnogenol® inhibits lipid accumulation in 3T3-L1 adipocytes with the modulation of reactive oxygen species (ROS) production associated with antioxidant enzyme responses.

    PubMed

    Lee, Ok-Hwan; Seo, Min-Jung; Choi, Hyeon-Son; Lee, Boo-Yong

    2012-03-01

    Pycnogenol® is a group of flavonoids with antioxidant effects. Adipogenesis is the process of adipocyte differentiation. It causes the increase of lipids as well as ROS (reactive oxygen species). Lipid accumulation and ROS production were determined in 3 T3-L1 adipocyte, and the effect of Pycnogenol® was evaluated. Lipid accumulation was elevated in adipocyte treated with hydrogen peroxide, one of the ROS. Pycnogenol® showed an inhibitory effect on the lipid accumulation and ROS production during the adipogenesis. We also investigated the molecular events associated with ROS production and lipid accumulation. Our results showed that Pycnogenol® inhibited the mRNA expression of pro-oxidant enzymes, such as NOX4 (NADPH (nicotinamide adenine dinucleotide phosphate hydrogen) oxidase 4), and the NADPH-producing G6PDH (glucose-6-phosphate dehydrogenase) enzyme. In addition, Pycnogenol® suppressed the mRNA abundance of adipogenic transcription factors, PPAR-γ (peroxisome proliferator-activated receptor γ) and C/EBP-α (CCAAT/enhancer binding protein α), and their target gene, aP2 (adipocyte protein 2) responsible for fatty acid transportation. On the other hand, Pycnogenol® increased the abundance of antioxidant proteins such as Cu/Zn-SOD (copper-zinc superoxide dismutase), Mn-SOD (manganese superoxide dismutase), GPx (glutathione peroxidase) and GR (glutathione reductase). Our results suggest that Pycnogenol® inhibits lipid accumulation and ROS production by regulating adipogenic gene expression and pro-/antioxidant enzyme responses in adipocytes.

  2. The brown adipocyte protein CIDEA promotes lipid droplet fusion via a phosphatidic acid-binding amphipathic helix

    PubMed Central

    Barneda, David; Planas-Iglesias, Joan; Gaspar, Maria L; Mohammadyani, Dariush; Prasannan, Sunil; Dormann, Dirk; Han, Gil-Soo; Jesch, Stephen A; Carman, George M; Kagan, Valerian; Parker, Malcolm G; Ktistakis, Nicholas T; Klein-Seetharaman, Judith; Dixon, Ann M; Henry, Susan A; Christian, Mark

    2015-01-01

    Maintenance of energy homeostasis depends on the highly regulated storage and release of triacylglycerol primarily in adipose tissue, and excessive storage is a feature of common metabolic disorders. CIDEA is a lipid droplet (LD)-protein enriched in brown adipocytes promoting the enlargement of LDs, which are dynamic, ubiquitous organelles specialized for storing neutral lipids. We demonstrate an essential role in this process for an amphipathic helix in CIDEA, which facilitates embedding in the LD phospholipid monolayer and binds phosphatidic acid (PA). LD pairs are docked by CIDEA trans-complexes through contributions of the N-terminal domain and a C-terminal dimerization region. These complexes, enriched at the LD–LD contact site, interact with the cone-shaped phospholipid PA and likely increase phospholipid barrier permeability, promoting LD fusion by transference of lipids. This physiological process is essential in adipocyte differentiation as well as serving to facilitate the tight coupling of lipolysis and lipogenesis in activated brown fat. DOI: http://dx.doi.org/10.7554/eLife.07485.001 PMID:26609809

  3. Anti-Inflammatory Effects of Rosiglitazone in Obesity-Impaired Wound Healing Depend on Adipocyte Differentiation

    PubMed Central

    Pfeilschifter, Josef; Frank, Stefan

    2016-01-01

    Combined diabetes-obesity syndromes severely impair regeneration of acute skin wounds in mouse models. This study assessed the contribution of subcutaneous adipose tissue to exacerbated wound inflammatory conditions. Genetically obese (ob/ob) mice showed an increased expression of positive transcriptional effectors of adipocyte differentiation such as Krüppel-like factor (KLF)-5 and peroxisome proliferator-activated receptor (PPAR)-γ and an associated expression of leptin and fatty acid-binding protein (FABP)-4, but also CXCL2 in isolated subcutaneous fat. This observation in obese mice is in keeping with differentially elevated levels of KLF-5, PPAR-γ, leptin, FABP-4 and CXCL2 in in vitro-differentiated 3T3-L1 adipocytes. Notably, CXCL2 expression restrictively appeared upon cytokine (IL-1β/TNF-α) stimulation only in mature, but not immature 3T3-L1 adipocytes. Of importance, the critical regulator of adipocyte maturation, PPAR-γ, was merely expressed in the final phase of in-vitro induced adipocyte differentiation from 3T3-L1 pre-adipocytes. Consistently, the PPAR-γ agonist rosiglitazone suppressed cytokine-induced CXCL2 release from mature adipocytes, but not from early 3T3-L1 adipocyte stages. The inhibitory effect of PPAR-γ activation on CXCL2 release appeared to be a general anti-inflammatory effect in mature adipocytes, as cytokine-induced cyclooxygenase (Cox)-2 was simultaneously repressed by rosiglitazone. In accordance with these findings, oral administration of rosiglitazone to wounded obese mice significantly changed subcutaneous adipocyte morphology, reduced wound CXCL2 and Cox-2 expression and improved tissue regeneration. Thus, our data suggest that PPAR-γ might provide a target to suppress inflammatory signals from mature adipocytes, which add to the prolonged wound inflammation observed in diabetes-obesity conditions. PMID:27992530

  4. Trans, trans-farnesol as a mevalonate-derived inducer of murine 3T3-F442A pre-adipocyte differentiation

    PubMed Central

    Torabi, Sheida

    2015-01-01

    Based on our finding that depletion of mevalonate-derived metabolites inhibits adipocyte differentiation, we hypothesize that trans, trans-farnesol (farnesol), a mevalonate-derived sesquiterpene, induces adipocyte differentiation. Farnesol dose-dependently (25–75 μmol/L) increased intracellular triglyceride content of murine 3T3-F442A pre-adipocytes measured by AdipoRed™ Assay and Oil Red-O staining. Concomitantly, farnesol dose-dependently increased glucose uptake and glucose transport protein 4 (GLUT4) expression without affecting cell viability. Furthermore, quantitative real-time polymerase chain reaction and Western blot showed that farnesol increased the mRNA and protein levels of peroxisome proliferator-activated receptor γ (PPARγ), a key regulator of adipocyte differentiation, and the mRNA levels of PPARγ-regulated fatty acid-binding protein 4 and adiponectin; in contrast, farnesol downregulated Pref-1 gene, a marker of pre-adipocytes. GW9662 (10 µmol/L), an antagonist of PPARγ, reversed the effects of farnesol on cellular lipid content, suggesting that PPARγ signaling pathway may mediate the farnesol effect. Farnesol (25–75 μmol/L) did not affect the mRNA level of 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting enzyme in the mevalonate pathway. Farnesol may be the mevalonate-derived inducer of adipocyte differentiation and potentially an insulin sensitizer via activation of PPARγ and upregulation of glucose uptake. PMID:26660152

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

    PubMed

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

    2014-05-01

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

  6. Differential effects of fibroblast growth factor and tumor promoters on the initiation and maintenance of adipocyte differentiation

    PubMed Central

    1989-01-01

    Fibroblast growth factor (FGF) has been shown to inhibit the differentiation of myogenic and adipogenic cell lines without inducing a proliferative response. We have previously shown that agents capable of activating protein kinase C (PKC), such as FGF and the phorbol ester tetradecanoyl phorbol-13-acetate (TPA), inhibit the differentiation of the adipogenic cell line TA1, as measured by the rapid loss of adipocyte-specific RNAs. We report here that the treatment of fully differentiated TA1 adipocytes with FGF at 10 ng/ml induces the reversal of adipocyte differentiation, even in cells where PKC activity has been down-regulated by TPA pretreatment. In contrast, TPA or lower concentrations of FGF (1 ng/ml), both effective inducers of c-fos RNA in adipocytes, fail to reverse adipocyte differentiation. The adipocytes, however, will extinguish differentiation-specific functions in response to TPA by the addition of a calcium ionophore. Therefore, we propose that there are two FGF-sensitive pathways in TA1 cells: one responsible for the initiation of differentiation (TPA sensitive) and another required for maintenance of the adipose phenotype (TPA insensitive). These results suggest that activation of two distinct signaling pathways--one PKC and calcium dependent, the other FGF activated but PKC independent--are capable of inhibiting the biochemical events responsible for the maintenance of adipocyte differentiation. PMID:2507555

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

    PubMed

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

    2012-04-01

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

  8. Skp2 promotes adipocyte differentiation via a p27{sup Kip1}-independent mechanism in primary mouse embryonic fibroblasts

    SciTech Connect

    Okada, Mitsuru; Sakai, Tamon; Nakamura, Takehiro; Tamamori-Adachi, Mimi; Kitajima, Shigetaka; Matsuki, Yasushi; Watanabe, Eijiro; Hiramatsu, Ryuji; Sakaue, Hiroshi Kasuga, Masato

    2009-02-06

    Skp2, the substrate-binding subunit of an SCF ubiquitin ligase complex, is a key regulator of cell cycle progression that targets substrates for degradation by the 26S proteasome. We have now shown that ablation of Skp2 in primary mouse embryonic fibroblasts (MEFs) results both in impairment of adipocyte differentiation and in the accumulation of the cyclin-dependent kinase inhibitor p27{sup Kip1}, a principal target of the SCF{sup Skp2} complex. Genetic ablation of p27{sup Kip1} in MEFs promoted both lipid accumulation and adipocyte-specific gene expression. However, depletion of p27{sup Kip1} by adenovirus-mediated RNA interference failed to correct the impairment of adipocyte differentiation in Skp2{sup -/-} MEFs. In contrast, troglitazone, a high-affinity ligand for peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}), largely restored lipid accumulation and PPAR{gamma} gene expression in Skp2{sup -/-} MEFs. Our data suggest that Skp2 plays an essential role in adipogenesis in MEFs in a manner that is at least in part independent of regulation of p27{sup Kip1} expression.

  9. PPARγ ligand production is tightly linked to clonal expansion during initiation of adipocyte differentiation[S

    PubMed Central

    Hallenborg, Philip; Petersen, Rasmus Koefoed; Feddersen, Søren; Sundekilde, Ulrik; Hansen, Jacob B.; Blagoev, Blagoy; Madsen, Lise; Kristiansen, Karsten

    2014-01-01

    Adipocyte differentiation is orchestrated by the ligand-activated nuclear receptor PPARγ. Endogenous ligands comprise oxidized derivatives of arachidonic acid and structurally similar PUFAs. Although expression of PPARγ peaks in mature adipocytes, ligands are produced primarily at the onset of differentiation. Concomitant with agonist production, murine fibroblasts undergo two rounds of mitosis referred to as mitotic clonal expansion. Here we show that mouse embryonic fibroblasts deficient in either of two cell cycle inhibitors, the transcription factor p53 or its target gene encoding the cyclin-dependent kinase inhibitor p21, exhibit increased adipogenic potential. The antiadipogenic effect of p53 relied on its transcriptional activity and p21 expression but was circumvented by administration of an exogenous PPARγ agonist suggesting a linkage between cell cycling and PPARγ ligand production. Indeed, cell cycle inhibitory compounds decreased PPARγ ligand production in differentiating 3T3-L1 preadipocytes. Furthermore, these inhibitors abolished the release of arachidonic acid induced by the hormonal cocktail initiating adipogenesis. Collectively, our results suggest that murine fibroblasts require clonal expansion for PPARγ ligand production at the onset of adipocyte differentiation. PMID:25312885

  10. Knockdown of PTRF ameliorates adipocyte differentiation and functionality of human mesenchymal stem cells.

    PubMed

    Perez-Diaz, Sergio; Garcia-Rodriguez, Beatriz; Gonzalez-Irazabal, Yolanda; Valero, Monica; Lagos-Lizan, Javier; Arbones-Mainar, Jose M

    2017-01-01

    Healthy expansion of human adipose tissue requires mesenchymal stem cells (hMSC) able to proliferate and differentiate into mature adipocytes. Hence, characterization of those factors that coordinate hMSC-to-adipocyte transition is of paramount importance to modulate the adipose tissue expansion. It has been previously reported that the adipogenic program of hMSC can be disrupted by upregulating caveolar proteins, and polymerase I and transcript release factor (PTRF) is an integral component of caveolae, highly expressed in adipose tissue. Here, we hypothesized that the role of PTRF in adipocyte functionality might stem from an effect on hMSC. To test this hypothesis, we isolated hMSC from the subcutaneous fat depot. We found an upregulated expression of the PTRF associated with decreased adipogenic potential of hMSC, likely due to the existence of senescent adipocyte precursors. Employing short hairpin RNA-based constructs to stably reduce PTRF, we were able to restore insulin sensitivity and reduced basal lipolysis and leptin levels in human adipocytes with high levels of PTRF. Additionally, we pinpointed the detrimental effect caused by PTRF on the adipose tissue to the existence of senescent adipocyte precursors unable to proliferate and differentiate into adipocytes. This study provides evidence that impaired adipocyte functionality can be corrected, at least partially, by PTRF downregulation and warrants further in vivo research in patients with dysfunctional adipose tissue to prevent metabolic complications.

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

    PubMed

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

    2013-01-01

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

  12. Fetuin-A downregulates adiponectin through Wnt-PPARγ pathway in lipid induced inflamed adipocyte.

    PubMed

    Agarwal, Soumik; Chattopadhyay, Mrittika; Mukherjee, Sandip; Dasgupta, Suman; Mukhopadhyay, Satinath; Bhattacharya, Samir

    2017-01-01

    Adiponectin secreted from adipocytes is an anti-diabetic and anti-atherogenic adipokine. Adiponectin level is known to fall significantly in obesity induced type 2 diabetes which worsen insulin sensitivity because of aberrant lipid management. However, underlying mechanism of adiponectin decrease in obese diabetic condition is yet unclear. We report here that lowering of plasma adiponectin coincided with the higher Fetuin A (FetA) level in high fat diet (HFD) induced obese diabetic mice. Knock down of FetA gene (FetA(KD)) elevated adiponectin level markedly in HFD mice, while reinforcement of FetA into FetA(KD)HFD mice reduced its level again. These results indicate FetA's involvement in the lowering of adiponectin level in obesity induced diabetic mice. Our findings to understand how FetA could affect adiponectin decrease demonstrated that FetA could enhance Wnt3a expression in the adipocyte of HFD mice. FetA addition to 3T3L1 adipocyte incubation elevated Wnt3a expression in a dose dependent manner. Overexpression of Wnt3a by FetA inhibited PPARγ and adiponectin. FetA failed to reduce PPARγ and adiponectin in Wnt3a gene knocked down 3T3L1` adipocytes. All these suggest that FetA mediate its inhibitory effect on adiponectin through Wnt3a-PPARγ pathway. Inhibition of adiponectin expression through FetA and Wnt3a significantly compromised with the activation of AMPK and its downstream signalling molecules which adversely affected lipid management causing loss of insulin sensitivity. Downregulation of adiponectin in inflamed adipocyte by FetA through the mediation of Wnt3a and PPARγ is a new report.

  13. Branched short-chain fatty acids modulate glucose and lipid metabolism in primary adipocytes

    PubMed Central

    Heimann, Emilia; Nyman, Margareta; Pålbrink, Ann-Ki; Lindkvist-Petersson, Karin; Degerman, Eva

    2016-01-01

    ABSTRACT Short-chain fatty acids (SCFAs), e.g. acetic acid, propionic acid and butyric acid, generated through colonic fermentation of dietary fibers, have been shown to reach the systemic circulation at micromolar concentrations. Moreover, SCFAs have been conferred anti-obesity properties in both animal models and human subjects. Branched SCFAs (BSCFAs), e.g., isobutyric and isovaleric acid, are generated by fermentation of branched amino acids, generated from undigested protein reaching colon. However, BSCFAs have been sparsely investigated when referring to effects on energy metabolism. Here we primarily investigate the effects of isobutyric acid and isovaleric acid on glucose and lipid metabolism in primary rat and human adipocytes. BSCFAs inhibited both cAMP-mediated lipolysis and insulin-stimulated de novo lipogenesis at 10 mM, whereas isobutyric acid potentiated insulin-stimulated glucose uptake by all concentrations (1, 3 and 10 mM) in rat adipocytes. For human adipocytes, only SCFAs inhibited lipolysis at 10 mM. In both in vitro models, BSCFAs and SCFAs reduced phosphorylation of hormone sensitive lipase, a rate limiting enzyme in lipolysis. In addition, BSCFAs and SCFAs, in contrast to insulin, inhibited lipolysis in the presence of wortmannin, a phosphatidylinositide 3-kinase inhibitor and OPC3911, a phosphodiesterase 3 inhibitor in rat adipocytes. Furthermore, BSCFAs and SCFAs reduced insulin-mediated phosphorylation of protein kinase B. To conclude, BSCFAs have effects on adipocyte lipid and glucose metabolism that can contribute to improved insulin sensitivity in individuals with disturbed metabolism. PMID:27994949

  14. Participation of TNF-α in Inhibitory Effects of Adipocytes on Osteoblast Differentiation.

    PubMed

    Abuna, Robrigo P F; De Oliveira, Fabiola S; Santos, Thiago De S; Guerra, Thais R; Rosa, Adalberto L; Beloti, Marcio M

    2016-01-01

    Mesenchymal stem cells from bone marrow (BM-MSCs) and adipose tissue (AT-MSCs) are attractive tools for cell-based therapies to repair bone tissue. In this study, we investigated the osteogenic and adipogenic potential of BM-MSCs and AT-MSCs as well as the effect of crosstalk between osteoblasts and adipocytes on cell phenotype expression. Rat BM-MSCs and AT-MSCs were cultured either in growth, osteogenic, or adipogenic medium to evaluate osteoblast and adipocyte differentiation. Additionally, osteoblasts and adipocytes were indirectly co-cultured to investigate the effect of adipocytes on osteoblast differentiation and vice versa. BM-MSCs and AT-MSCs exhibit osteogenic and adipogenic potential under non-differentiation-inducing conditions. When exposed to osteogenic medium, BM-MSCs exhibited higher expression of bone markers compared with AT-MSCs. Conversely, under adipogenic conditions, AT-MSCs displayed higher expression of adipose tissue markers compared with BM-MSCs. The presence of adipocytes as indirect co-culture repressed the expression of the osteoblast phenotype, whereas osteoblasts did not exert remarkable effect on adipocytes. The inhibitory effect of adipocytes on osteoblasts was due to the release of tumor necrosis factor alpha (TNF-α) in culture medium by adipocytes. Indeed, the addition of exogenous TNF-α in culture medium repressed the differentiation of BM-MSCs into osteoblasts mimicking the indirect co-culture effect. In conclusion, our study showed that BM-MSCs are more osteogenic while AT-MSCs are more adipogenic. Additionally, we demonstrated the key role of TNF-α secreted by adipocytes on the inhibition of osteoblast differentiation. Thus, we postulate that the higher osteogenic potential of BM-MSCs makes them the first choice for inducing bone repair in cell-based therapies.

  15. Regulation of Autophagy-Related Protein and Cell Differentiation by High Mobility Group Box 1 Protein in Adipocytes

    PubMed Central

    Feng, Huanhuan; Zhang, Guojun; Liu, Guoyan; Yang, Can

    2016-01-01

    High mobility group box 1 protein (HMGB1) is a molecule related to the development of inflammation. Autophagy is vital to maintain cellular homeostasis and protect against inflammation of adipocyte injury. Our recent work focused on the relationship of HMGB1 and autophagy in 3T3-L1 cells. In vivo experimental results showed that, compared with the normal-diet group, the high-fat diet mice displayed an increase in adipocyte size in the epididymal adipose tissues. The expression levels of HMGB1 and LC3II also increased in epididymal adipose tissues in high-fat diet group compared to the normal-diet mice. The in vitro results indicated that HMGB1 protein treatment increased LC3II formation in 3T3-L1 preadipocytes in contrast to that in the control group. Furthermore, LC3II formation was inhibited through HMGB1 knockdown by siRNA. Treatment with the HMGB1 protein enhanced LC3II expression after 2 and 4 days but decreased the expression after 8 and 10 days among various differentiation stages of adipocytes. By contrast, FABP4 expression decreased on the fourth day and increased on the eighth day. Hence, the HMGB1 protein modulated autophagy-related proteins and lipid-metabolism-related genes in adipocytes and could be a new target for treatment of obesity and related metabolic diseases. PMID:27843198

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

    PubMed Central

    2013-01-01

    Background Tendinopathies are often empirically treated with oral/topical nonsteroidal anti-inflammatory medications and corticosteroid injections despite their unclear effects on tendon regeneration. Recent studies indicate that tendon progenitors exhibit stem cell-like properties, i.e., differentiation to osteoblasts, adipocytes, and chondrocytes, in addition to tenocytes. Our present study aims at understanding the effects of triamcinolone acetonide and diclofenac on tenocytic differentiation of mesenchymal stem cells. Methods The murine fibroblast C3H10T1/2 cell line was induced to tenocytic differentiation by growth differentiation factor-7. Cell proliferation and differentiation with the exposure of different concentrations of triamcinolone acetonide and diclofenac were measured by WST-1 assay and real-time polymerase chain reaction analysis, respectively. Results Cell proliferation was decreased in a concentration-dependent manner when exposed to triamcinolone acetonide and diclofenac. In addition to tenocytic differentiation, adipocyte formation was observed, both at gene expression and microscopic level, when the cells were exposed to triamcinolone acetonide or high concentrations of diclofenac. Conclusions Our results indicate that triamcinolone acetonide and diclofenac might alter mesenchymal stem cell differentiation in a nonfavorable way regarding tendon regeneration; therefore, these medications should be used with more caution clinically. PMID:24004657

  17. Using a 3D Culture System to Differentiate Visceral Adipocytes In Vitro.

    PubMed

    Emont, Margo P; Yu, Hui; Jun, Heejin; Hong, Xiaowei; Maganti, Nenita; Stegemann, Jan P; Wu, Jun

    2015-12-01

    It has long been recognized that body fat distribution and regional adiposity play a major role in the control of metabolic homeostasis. However, the ability to study and compare the cell autonomous regulation and response of adipocytes from different fat depots has been hampered by the difficulty of inducing preadipocytes isolated from the visceral depot to differentiate into mature adipocytes in culture. Here, we present an easily created 3-dimensional (3D) culture system that can be used to differentiate preadipocytes from the visceral depot as robustly as those from the sc depot. The cells differentiated in these 3D collagen gels are mature adipocytes that retain depot-specific characteristics, as determined by imaging, gene expression, and functional assays. This 3D culture system therefore allows for study of the development and function of adipocytes from both depots in vitro and may ultimately lead to a greater understanding of site-specific functional differences of adipose tissues to metabolic dysregulation.

  18. Diabetic human adipose tissue-derived mesenchymal stem cells fail to differentiate in functional adipocytes.

    PubMed

    Barbagallo, Ignazio; Li Volti, Giovanni; Galvano, Fabio; Tettamanti, Guido; Pluchinotta, Francesca R; Bergante, Sonia; Vanella, Luca

    2016-11-30

    Adipose tissue dysfunction represents a hallmark of diabetic patients and is a consequence of the altered homeostasis of this tissue. Mesenchymal stem cells (MSCs) and their differentiation into adipocytes contribute significantly in maintaining the mass and function of adult adipose tissue. The aim of this study was to evaluate the differentiation of MSCs from patients suffering type 2 diabetes (dASC) and how such process results in hyperplasia or rather a stop of adipocyte turnover resulting in hypertrophy of mature adipocytes. Our results showed that gene profile of all adipogenic markers is not expressed in diabetic cells after differentiation indicating that diabetic cells fail to differentiate into adipocytes. Interestingly, delta like 1, peroxisome proliferator-activated receptor alpha, and interleukin 1β were upregulated whereas Sirtuin 1 and insulin receptor substrate 1 gene expression were found downregulated in dASC compared to cells obtained from healthy subjects. Taken together our data indicate that dASC lose their ability to differentiate into mature and functional adipocytes. In conclusion, our in vitro study is the first to suggest that diabetic patients might develop obesity through a hypertrophy of existing mature adipocytes due to failure turnover of adipose tissue.

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

    PubMed

    Hu, Y; Davies, G E

    2009-09-01

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

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

    PubMed

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

    2014-08-08

    Obesity-induced adipose tissue (AT) dysfunction results in a chronic low-grade inflammation that predisposes to the development of insulin resistance and type 2 diabetes. During the development of obesity, the AT-resident immune cell profile alters to create a pro-inflammatory state. Very recently, CD1d-restricted invariant (i) natural killer T (NKT) cells, a unique subset of lymphocytes that are reactive to so called lipid antigens, were implicated in AT homeostasis. Interestingly, recent data also suggest that human and mouse adipocytes can present such lipid antigens to iNKT cells in a CD1d-dependent fashion, but little is known about the lipid antigen presentation machinery in adipocytes. Here we show that CD1d, as well as the lipid antigen loading machinery genes pro-saposin (Psap), Niemann Pick type C2 (Npc2), α-galactosidase (Gla), are up-regulated in early adipogenesis, and are transcriptionally controlled by CCAAT/enhancer-binding protein (C/EBP)-β and -δ. Moreover, adipocyte-induced Th1 and Th2 cytokine release by iNKT cells also occurred in the absence of exogenous ligands, suggesting the display of endogenous lipid antigen-D1d complexes by 3T3-L1 adipocytes. Furthermore, we identified microsomal triglyceride transfer protein, which we show is also under the transcriptional regulation of C/EBPβ and -δ, as a novel player in the presentation of endogenous lipid antigens by adipocytes. Overall, our findings indicate that adipocytes can function as non-professional lipid antigen presenting cells, which may present an important aspect of adipocyte-immune cell communication in the regulation of whole body energy metabolism and immune homeostasis.

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

    PubMed Central

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

    2014-01-01

    Obesity-induced adipose tissue (AT) dysfunction results in a chronic low-grade inflammation that predisposes to the development of insulin resistance and type 2 diabetes. During the development of obesity, the AT-resident immune cell profile alters to create a pro-inflammatory state. Very recently, CD1d-restricted invariant (i) natural killer T (NKT) cells, a unique subset of lymphocytes that are reactive to so called lipid antigens, were implicated in AT homeostasis. Interestingly, recent data also suggest that human and mouse adipocytes can present such lipid antigens to iNKT cells in a CD1d-dependent fashion, but little is known about the lipid antigen presentation machinery in adipocytes. Here we show that CD1d, as well as the lipid antigen loading machinery genes pro-saposin (Psap), Niemann Pick type C2 (Npc2), α-galactosidase (Gla), are up-regulated in early adipogenesis, and are transcriptionally controlled by CCAAT/enhancer-binding protein (C/EBP)-β and -δ. Moreover, adipocyte-induced Th1 and Th2 cytokine release by iNKT cells also occurred in the absence of exogenous ligands, suggesting the display of endogenous lipid antigen-D1d complexes by 3T3-L1 adipocytes. Furthermore, we identified microsomal triglyceride transfer protein, which we show is also under the transcriptional regulation of C/EBPβ and –δ, as a novel player in the presentation of endogenous lipid antigens by adipocytes. Overall, our findings indicate that adipocytes can function as non-professional lipid antigen presenting cells, which may present an important aspect of adipocyte-immune cell communication in the regulation of whole body energy metabolism and immune homeostasis. PMID:24966328

  2. Proliferation and differentiation of brown adipocytes from interstitial cells during cold acclimation

    SciTech Connect

    Bukowiecki, L.J.; Geloeen, A.; Collet, A.J.

    1986-06-01

    The mechanisms of brown adipocyte proliferation and differentiation during cold acclimation (and/or adaptation to hyperphagia) have been studied by quantitative photonic radioautography. (/sup 3/H)thymidine was injected to warm-acclimated (25/sup 0/C) rats and to animals exposed to 5/sup 0/C for 2 days. Samples of interscapular brown adipose tissue were collected for quantitative analysis of mitotic frequencies at various periods of time (4 h-15 days) after the injection of (/sup 3/H)thymidine, the rats being maintained at the temperatures to which they were initially exposed. It was found that cold exposure for 2 days markedly enhanced mitotic activity in endothelial cells, interstitial cells, and brown preadipocytes rather than in fully differentiated brown adipocytes. The total tissue labeling index (percent of labeled nuclei) increased approx.70 times over control values. The authors now report that cellular labeling progressively increased in mature brown adipocytes during cold acclimation, whereas it correspondingly decreased in interstitial cells and brown preadipocytes. This indicates that the sequence of events for cellular differentiation is interstitial cells ..-->.. brown preadipocytes ..-->.. mature brown adipocytes. Remarkable, labeling frequency did not change in endothelial cells during cold acclimation demonstrating that these cells cannot be considered as progenitors of brown adipocytes. It is suggested that brown adipocyte proliferation and differentiation from interstitial cells represent the fundamental phenomena explaining the enhanced capacity of cold-acclimated and/or hyperphagic rats to respond calorigenically to catecholamines.

  3. Vinculin promotes nuclear localization of TAZ to inhibit ECM stiffness-dependent differentiation into adipocytes.

    PubMed

    Kuroda, Mito; Wada, Hiroki; Kimura, Yasuhisa; Ueda, Kazumitsu; Kioka, Noriyuki

    2017-03-01

    Extracellular matrix (ECM) stiffness regulates the lineage commitment of mesenchymal stem cells (MSCs). Although cells sense ECM stiffness through focal adhesions, how cells sense ECM stiffness and regulate ECM stiffness-dependent differentiation remains largely unclear. In this study, we show that the cytoskeletal focal adhesion protein vinculin plays a critical role in the ECM stiffness-dependent adipocyte differentiation of MSCs. ST2 mouse MSCs differentiate into adipocytes and osteoblasts in an ECM stiffness-dependent manner. We find that a rigid ECM increases the amount of cytoskeleton-associated vinculin and promotes the nuclear localization and activity of the transcriptional coactivator paralogs Yes-associated protein (YAP, also known as YAP1) and transcriptional coactivator with a PDZ-binding motif (TAZ, also known as WWTR1) (hereafter YAP/TAZ). Vinculin is necessary for enhanced nuclear localization and activity of YAP/TAZ on the rigid ECM but it does not affect the phosphorylation of the YAP/TAZ kinase LATS1. Furthermore, vinculin depletion promotes differentiation into adipocytes on rigid ECM, while it inhibits differentiation into osteoblasts. Finally, TAZ knockdown was less effective at promoting adipocyte differentiation in vinculin-depleted cells than in control cells. These results suggest that vinculin promotes the nuclear localization of transcription factor TAZ to inhibit the adipocyte differentiation on rigid ECM.

  4. Isoform-specific regulation of adipocyte differentiation by Akt/protein kinase B{alpha}

    SciTech Connect

    Yun, Sung-Ji; Kim, Eun-Kyoung; Tucker, David F.; Kim, Chi Dae; Birnbaum, Morris J.; Bae, Sun Sik

    2008-06-20

    The phosphatidylinositol 3-kinase (PI3K)/Akt pathway tightly regulates adipose cell differentiation. Here we show that loss of Akt1/PKB{alpha} in primary mouse embryo fibroblast (MEF) cells results in a defect of adipocyte differentiation. Adipocyte differentiation in vitro and ex vivo was restored in cells lacking both Akt1/PKB{alpha} and Akt2/PKB{beta} by ectopic expression of Akt1/PKB{alpha} but not Akt2/PKB{beta}. Akt1/PKB{alpha} was found to be the major regulator of phosphorylation and nuclear export of FoxO1, whose presence in the nucleus strongly attenuates adipocyte differentiation. Differentiation-induced cell division was significantly abrogated in Akt1/PKB{alpha}-deficient cells, but was restored after forced expression of Akt1/PKB{alpha}. Moreover, expression of p27{sup Kip1}, an inhibitor of the cell cycle, was down regulated in an Akt1/PKB{alpha}-specific manner during adipocyte differentiation. Based on these data, we suggest that the Akt1/PKB{alpha} isoform plays a major role in adipocyte differentiation by regulating FoxO1 and p27{sup Kip1}.

  5. Cranberries (Oxycoccus quadripetalus) inhibit lipid metabolism and modulate leptin and adiponectin secretion in 3T3-L1 adipocytes.

    PubMed

    Kowalska, Katarzyna; Olejnik, Anna; Rychlik, Joanna; Grajek, Włodzimierz

    2015-10-15

    It has previously been shown that lyophilized cranberries (LCB) decreased lipid accumulation in 3T3-L1 cells and inhibited preadipocyte differentiation by down-regulation of the expression of key transcription factors (PPARγ, C/EBPα, SREBP1) of the adipogenesis pathway. To elucidate the molecular basis of anti-lipogenic activity of LCB, the expression of several genes involved in lipid metabolism, such as adipocyte fatty acid-binding protein (aP2), lipoprotein lipase (LPL), fatty acid synthase (FAS), hormone sensitive lipase (HSL) and perilipin 1 (PLIN1), was examined in the present study. Additionally, the effects of LCB on adiponectin and leptin expression and protein secretion were also investigated. LCB reduced lipid accumulation during preadipocyte differentiation by down-regulation of the mRNA level of aP2, FAS, LPL, HSL and PLIN1. Moreover, LCB decreased leptin gene expression and increased adiponectin gene expression and protein secretion in a dose-dependent manner. Therefore cranberries could be considered as bioactive factors, which are effective in the inhibition of adipose tissue mass production.

  6. On the Formation of Lipid Droplets in Human Adipocytes: The Organization of the Perilipin–Vimentin Cortex

    PubMed Central

    Heid, Hans; Rickelt, Steffen; Zimbelmann, Ralf; Winter, Stefanie; Schumacher, Heiderose; Dörflinger, Yvette; Kuhn, Caecilia; Franke, Werner W.

    2014-01-01

    We report on the heterogeneity and diversity of lipid droplets (LDs) in early stages of adipogenesis by elucidating the cell and molecular biology of amphiphilic and cytoskeletal proteins regulating and stabilizing the generation of LDs in human adipose cells. A plethora of distinct and differently sized LDs was detected by a brief application of adipocyte differentiation medium and additional short treatment with oleic acid. Using these cells and highly specific antibodies for LD-binding proteins of the perilipin (PLIN) family, we could distinguish between endogenously derived LDs (endogenous LDs) positive for perilipin from exogenously induced LDs (exogenous LDs) positive for adipophilin, TIP47 and S3-12. Having optimized these stimulation conditions, we used early adipogenic differentiation stages to investigate small-sized LDs and concentrated on LD-protein associations with the intermediate-sized filament (IF) vimentin. This IF protein was described earlier to surround lipid globules, showing spherical, cage-like structures. Consequently - by biochemical methods, by immunofluorescence microscopy and by electron- and immunoelectron microscopy - various stages of emerging lipid globules were revealed with perilipin as linking protein between LDs and vimentin. For this LD-PLIN-Vimentin connection, a model is now proposed, suggesting an interaction of proteins via opposed charged amino acid domains respectively. In addition, multiple sheaths of smooth endoplasmic reticulum cisternae surrounding concentrically nascent LDs are shown. Based on our comprehensive localization studies we present and discuss a novel pathway for the LD formation. PMID:24587346

  7. (-)-Epigallocatechin gallate suppresses adipocyte differentiation through the MEK/ERK and PI3K/Akt pathways.

    PubMed

    Kim, Hyojung; Sakamoto, Kazuichi

    2012-02-01

    EGCG [(-)-epigallocatechin gallate], tea catechin, is one of the compounds that has been reported to act against obesity and diabetes. To determine the effect of EGCG on adipocyte differentiation, we treated 3T3-L1 preadipocytes with different catechins. Oil Red O staining showed significantly reduced intracellular lipid accumulation, especially with EGCG. Cell cycle analysis showed that EGCG inhibited cell proliferation by disturbing the cell cycle during the clonal expansion of 3T3-L1. RT-PCR (real-time PCR) demonstrated that EGCG noticeably reduced mRNA expression of PPARγ (peroxisome proliferator-activated receptor γ), C/EBPα (CCAAT/enhancer-binding protein α) and FoxO1 (forkhead box class O1). EGCG also caused a significant decrease in the transcription of FoxO1 - the forkhead transcription factor class O1 involved in adipocyte differentiation - via the PI3K (phosphoinositide 3-kinase)/Akt and MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] pathways. These results suggest that EGCG suppresses the clonal expansion of adipocytes by inactivating FoxO1 via insulin signalling and stress-dependent MAPK pathways.

  8. Global Mapping of Cell Type–Specific Open Chromatin by FAIRE-seq Reveals the Regulatory Role of the NFI Family in Adipocyte Differentiation

    PubMed Central

    Yu, Jing; Hirose-Yotsuya, Lisa; Take, Kazumi; Sun, Wei; Iwabu, Masato; Okada-Iwabu, Miki; Fujita, Takanori; Aoyama, Tomohisa; Tsutsumi, Shuichi; Ueki, Kohjiro; Kodama, Tatsuhiko; Sakai, Juro; Aburatani, Hiroyuki; Kadowaki, Takashi

    2011-01-01

    Identification of regulatory elements within the genome is crucial for understanding the mechanisms that govern cell type–specific gene expression. We generated genome-wide maps of open chromatin sites in 3T3-L1 adipocytes (on day 0 and day 8 of differentiation) and NIH-3T3 fibroblasts using formaldehyde-assisted isolation of regulatory elements coupled with high-throughput sequencing (FAIRE-seq). FAIRE peaks at the promoter were associated with active transcription and histone modifications of H3K4me3 and H3K27ac. Non-promoter FAIRE peaks were characterized by H3K4me1+/me3-, the signature of enhancers, and were largely located in distal regions. The non-promoter FAIRE peaks showed dynamic change during differentiation, while the promoter FAIRE peaks were relatively constant. Functionally, the adipocyte- and preadipocyte-specific non-promoter FAIRE peaks were, respectively, associated with genes up-regulated and down-regulated by differentiation. Genes highly up-regulated during differentiation were associated with multiple clustered adipocyte-specific FAIRE peaks. Among the adipocyte-specific FAIRE peaks, 45.3% and 11.7% overlapped binding sites for, respectively, PPARγ and C/EBPα, the master regulators of adipocyte differentiation. Computational motif analyses of the adipocyte-specific FAIRE peaks revealed enrichment of a binding motif for nuclear family I (NFI) transcription factors. Indeed, ChIP assay showed that NFI occupy the adipocyte-specific FAIRE peaks and/or the PPARγ binding sites near PPARγ, C/EBPα, and aP2 genes. Overexpression of NFIA in 3T3-L1 cells resulted in robust induction of these genes and lipid droplet formation without differentiation stimulus. Overexpression of dominant-negative NFIA or siRNA–mediated knockdown of NFIA or NFIB significantly suppressed both induction of genes and lipid accumulation during differentiation, suggesting a physiological function of these factors in the adipogenic program. Together, our study

  9. Fibrin glue is a candidate scaffold for long-term therapeutic protein expression in spontaneously differentiated adipocytes in vitro

    SciTech Connect

    Aoyagi, Yasuyuki; Kuroda, Masayuki; Asada, Sakiyo; Tanaka, Shigeaki; Konno, Shunichi; Tanio, Masami; Aso, Masayuki; Okamoto, Yoshitaka; Nakayama, Toshinori; Saito, Yasushi; Bujo, Hideaki

    2012-01-01

    Adipose tissue is expected to provide a source of cells for protein replacement therapies via auto-transplantation. However, the conditioning of the environment surrounding the transplanted adipocytes for their long-term survival and protein secretion properties has not been established. We have recently developed a preparation procedure for preadipocytes, ceiling culture-derived proliferative adipocytes (ccdPAs), as a therapeutic gene vehicle suitable for stable gene product secretion. We herein report the results of our evaluation of using fibrin glue as a scaffold for the transplanted ccdPAs for the expression of a transduced gene in a three-dimensional culture system. The ccdPAs secreted the functional protein translated from an exogenously transduced gene, as well as physiological adipocyte proteins, and the long viability of ccdPAs (up to 84 days) was dependent on the fibrinogen concentrations. The ccdPAs spontaneously accumulated lipid droplets, and their expression levels of the transduced exogenous gene with its product were maintained for at least 56 days. The fibrinogen concentration modified the adipogenic differentiation of ccdPAs and their exogenous gene expression levels, and the levels of exogenously transduced gene expression at the different fibrinogen concentrations were dependent on the extent of adipogenic differentiation in the gel. These results indicate that fibrin glue helps to maintain the high adipogenic potential of cultured adipocytes after passaging in a 3D culture system, and suggests that once they are successfully implanted at the transplantation site, the cells exhibit increased expression of the transduced gene with adipogenic differentiation.

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

    PubMed

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

    2004-06-01

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

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

    PubMed

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

    2014-01-01

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

  12. Expression of Caveolin 1 Is Enhanced by DNA Demethylation during Adipocyte Differentiation. Status of Insulin Signaling

    PubMed Central

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

    2014-01-01

    Caveolin 1 (Cav-1) is an essential constituent of adipocyte caveolae which binds the beta subunit of the insulin receptor (IR) and is implicated in the regulation of insulin signaling. We have found that, during adipocyte differentiation of 3T3-L1 cells the promoter, exon 1 and first intron of the Cav-1 gene undergo a demethylation process that is accompanied by a strong induction of Cav-1 expression, indicating that epigenetic mechanisms must have a pivotal role in this differentiation process. Furthermore, IR, PKB-Akt and Glut-4 expression are also increased during the differentiation process suggesting a coordinated regulation with Cav-1. Activation of Cav-1 protein by phosphorylation arises during the differentiation process, yet in fully mature adipocytes insulin is no longer able to significantly increase Cav-1 phosphorylation. However, these long-term differentiated cells are still able to respond adequately to insulin, increasing IR and PKB-Akt phosphorylation and glucose uptake. The activation of Cav-1 during the adipocyte differentiation process could facilitate the maintenance of insulin sensitivity by these fully mature adipocytes isolated from additional external stimuli. However, under the influence of physiological conditions associated to obesity, such as chronic inflammation and hypoxia, insulin sensitivity would finally be compromised. PMID:24751908

  13. Chinese herbal medicine Yi-Gan-San decreases the lipid accumulation in mouse 3T3-L1 adipocytes by modulating the activities of transcription factors SREBP-1c and FoxO1.

    PubMed

    Izumi, Masayuki; Seki, Takashi; Iwasaki, Koh; Sakamoto, Kazuichi

    2009-09-01

    Abnormal lipid metabolism in adipose tissue is closely related to the occurrence and progression of a wide variety of metabolic syndromes. We have analyzed the pharmacological effects of Chinese herbal medicines on cell differentiation and lipid metabolism in adipocytes. Yi-Gan-San (YGS) is a Chinese herbal medicine that is effective in treating the behavioral and psychological symptoms of dementia; however, its physiological mechanism remains unclear. We analyzed the effects of YGS on lipid accumulation in mouse 3T3-L1 adipocytes. Adipocyte differentiation was induced in mouse 3T3-L1 preadipocytes by treatment with the mixture of dexamethasone, 3-iso-butyl-1-methylxanthine, and insulin, and cells were cultured for 8 days with Chinese herbal medicines, including YGS. YGS effectively reduced the lipid accumulation in the differentiated 3T3-L1 cells in a dose-dependent manner, but had no effect on cell viability. YGS also reduced the activity of glycerol-3-phosphate dehydrogenase, an enzyme involved in lipid synthesis. In contrast, YGS gave no noticeable effect on glucose uptake and fatty acid uptake in the differentiated 3T3-L1 cells. Moreover, we established the stably transfected 3T3-L1 cell lines, each of which expresses the luciferase reporter gene under the control of sterol regulatory element-binding protein-1c (SREBP-1c) or FoxO1. SREBP-1c is a transcription factor involved in fatty acid synthesis, and FoxO1 is a forkhead-type transcription factor involved in adipocyte differentiation. Using these cell lines, we showed that YGS reduced the transcriptional activity of SREBP-1c, whereas YGS increased the activity of FoxO1. Thus, YGS may suppress lipid synthesis and fat accumulation in adipocytes through modulating the activities of SREBP-1c and FoxO1.

  14. Proteomic analysis of proteins associated with lipid droplets of basal and lipolytically stimulated 3T3-L1 adipocytes.

    PubMed

    Brasaemle, Dawn L; Dolios, Georgia; Shapiro, Lawrence; Wang, Rong

    2004-11-05

    Adipocytes hold the body's major energy reserve as triacylglycerols packaged in large lipid droplets. Perilipins, the most abundant proteins on these lipid droplets, play a critical role in facilitating both triacylglycerol storage and hydrolysis. The stimulation of lipolysis by beta-adrenergic agonists triggers rapid phosphorylation of perilipin and translocation of hormone-sensitive lipase to the surfaces of lipid droplets and more gradual fragmentation and dispersion of micro-lipid droplets. Because few lipid droplet-associated proteins have been identified in adipocytes, we isolated lipid droplets from basal and lipolytically stimulated 3T3-L1 adipocytes and identified the component proteins by mass spectrometry. Structural proteins identified in both preparations include perilipin, S3-12, vimentin, and TIP47; in contrast, adipophilin, caveolin-1, and tubulin selectively localized to droplets in lipolytically stimulated cells. Lipid metabolic enzymes identified in both preparations include hormone-sensitive lipase, lanosterol synthase, NAD(P)-dependent steroid dehydrogenase-like protein, acyl-CoA synthetase, long chain family member (ACSL) 1, and CGI-58. 17-beta-Hydroxysteroid dehydrogenase, type 7, was identified only in basal preparations, whereas ACSL3 and 4 and two short-chain reductase/dehydrogenases were identified on droplets from lipolytically stimulated cells. Additionally, both preparations contained FSP27, ribophorin I, EHD2, diaphorase I, and ancient ubiquitous protein. Basal preparations contained CGI-49, whereas lipid droplets from lipolytically stimulated cells contained several Rab GTPases and tumor protein D54. A close association of mitochondria with lipid droplets was suggested by the identification of pyruvate carboxylase, prohibitin, and a subunit of ATP synthase in the preparations. Thus, adipocyte lipid droplets contain specific structural proteins as well as lipid metabolic enzymes; the structural reorganization of lipid droplets in

  15. Pmch-Deficiency in Rats Is Associated with Normal Adipocyte Differentiation and Lower Sympathetic Adipose Drive

    PubMed Central

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

    2013-01-01

    The orexigenic neuropeptide melanin-concentrating hormone (MCH), a product of Pmch, is an important mediator of energy homeostasis. Pmch-deficient rodents are lean and smaller, characterized by lower food intake, body-, and fat mass. Pmch is expressed in hypothalamic neurons that ultimately are components in the sympathetic nervous system (SNS) drive to white and interscapular brown adipose tissue (WAT, iBAT, respectively). MCH binds to MCH receptor 1 (MCH1R), which is present on adipocytes. Currently it is unknown if Pmch-ablation changes adipocyte differentiation or sympathetic adipose drive. Using Pmch-deficient and wild-type rats on a standard low-fat diet, we analyzed dorsal subcutaneous and perirenal WAT mass and adipocyte morphology (size and number) throughout development, and indices of sympathetic activation in WAT and iBAT during adulthood. Moreover, using an in vitro approach we investigated the ability of MCH to modulate 3T3-L1 adipocyte differentiation. Pmch-deficiency decreased dorsal subcutaneous and perirenal WAT mass by reducing adipocyte size, but not number. In line with this, in vitro 3T3-L1 adipocyte differentiation was unaffected by MCH. Finally, adult Pmch-deficient rats had lower norepinephrine turnover (an index of sympathetic adipose drive) in WAT and iBAT than wild-type rats. Collectively, our data indicate that MCH/MCH1R-pathway does not modify adipocyte differentiation, whereas Pmch-deficiency in laboratory rats lowers adiposity throughout development and sympathetic adipose drive during adulthood. PMID:23555928

  16. Berberine Suppresses Adipocyte Differentiation via Decreasing CREB Transcriptional Activity.

    PubMed

    Zhang, Juan; Tang, Hongju; Deng, Ruyuan; Wang, Ning; Zhang, Yuqing; Wang, Yao; Liu, Yun; Li, Fengying; Wang, Xiao; Zhou, Libin

    2015-01-01

    Berberine, one of the major constituents of Chinese herb Rhizoma coptidis, has been demonstrated to lower blood glucose, blood lipid, and body weight in patients with type 2 diabetes mellitus. The anti-obesity effect of berberine has been attributed to its anti-adipogenic activity. However, the underlying molecular mechanism remains largely unknown. In the present study, we found that berberine significantly suppressed the expressions of CCAAT/enhancer-binding protein (C/EBP)α, peroxisome proliferators-activated receptor γ2 (PPARγ2), and other adipogenic genes in the process of adipogenesis. Berberine decreased cAMP-response element-binding protein (CREB) phosphorylation and C/EBPβ expression at the early stage of 3T3-L1 preadipocyte differentiation. In addition, CREB phosphorylation and C/EBPβ expression induced by 3-isobutyl-1-methylxanthine (IBMX) and forskolin were also attenuated by berberine. The binding activities of cAMP responsive element (CRE) stimulated by IBMX and forskolin were inhibited by berberine. The binding of phosphorylated CREB to the promoter of C/EBPβ was abrogated by berberine after the induction of preadipocyte differentiation. These results suggest that berberine blocks adipogenesis mainly via suppressing CREB activity, which leads to a decrease in C/EBPβ-triggered transcriptional cascades.

  17. Isoliquiritigenin impairs insulin signaling and adipocyte differentiation through the inhibition of protein-tyrosine phosphatase 1B oxidation in 3T3-L1 preadipocytes.

    PubMed

    Park, Sun-Ji; Choe, Young-Geun; Kim, Jung-Hak; Chang, Kyu-Tae; Lee, Hyun-Shik; Lee, Dong-Seok

    2016-07-01

    Isoliquritigenin (ISL) is an abundant dietary flavonoid with a chalcone structure, which is an important constituent in Glycyrrhizae Radix (GR). ISL exhibits anti-oxidant activity, and this activity has been shown to play a beneficial role in various health conditions. However, it is unclear whether the anti-oxidant activity of ISL affects insulin signaling pathway and lipid accumulation of adipocytes. We sought to investigate the effects and molecular mechanisms of ISL on insulin-stimulated adipogenesis in 3T3-L1 cells. We investigated whether ISL attenuates insulin-induced Reactive Oxygen Species (ROS) generation, and whether ISL inhibits the lipid accumulation and the expression of adipogenic-genes during the differentiation of 3T3-L1 cells. ISL blocked the ROS generation, suppressed the lipid accumulation and the expression of adipocyte-specific proteins, which are increased in response to insulin stimulation during adipocyte differentiation of 3T3-L1 cells. We also investigated whether the anti-oxidant capacity of ISL is involved in regulating the molecular events of insulin-signaling cascade in 3T3-L1 adipocytes. ISL restores PTP1B activity by inhibiting PTP1B oxidation and IR/PI3K/AKT phosphorylation during the early stages of insulin-induced adipogenesis. Our findings show that the anti-oxidant capacity of ISL attenuated insulin IR/PI3K/AKT signaling through inhibition of PTP1B oxidation, and ultimately attenuated insulin-induced adipocyte differentiation of 3T3-L1 cells.

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

    SciTech Connect

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

    2012-06-08

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

  19. Stearoyl-CoA Desaturase 1 Is a Key Determinant of Membrane Lipid Composition in 3T3-L1 Adipocytes

    PubMed Central

    Hagen, Rachel; Vidal-Puig, Antonio

    2016-01-01

    Stearoyl-CoA desaturase 1 (SCD1) is a lipogenic enzyme important for the regulation of membrane lipid homeostasis; dysregulation likely contributes to obesity associated metabolic disturbances. SCD1 catalyses the Δ9 desaturation of 12-19 carbon saturated fatty acids to monounsaturated fatty acids. To understand its influence in cellular lipid composition we investigated the effect of genetic ablation of SCD1 in 3T3-L1 adipocytes on membrane microdomain lipid composition at the species-specific level. Using liquid chromatography/electrospray ionisation-tandem mass spectrometry, we quantified 70 species of ceramide, mono-, di- and trihexosylceramide, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, bis(monoacylglycero)phosphate, phosphatidylinositol and cholesterol in 3T3-L1 adipocytes in which a 90% reduction in scd1 mRNA expression was achieved with siRNA. Cholesterol content was unchanged although decreases in other lipids resulted in cholesterol accounting for a higher proportion of lipid in the membranes. This was associated with decreased membrane lateral diffusion. An increased ratio of 24:0 to 24:1 in ceramide, mono- and dihexosylceramide, and sphingomyelin likely also contributed to this decrease in lateral diffusion. Of particular interest, we observed a decrease in phospholipids containing arachidonic acid. Given the high degree of structural flexibility of this acyl chain this will influence membrane lateral diffusion, and is likely responsible for the transcriptional activation of Lands’ cycle enzymes lpcat3 and mboat7. Of relevance these profound changes in the lipidome were not accompanied by dramatic changes in gene expression in mature differentiated adipocytes, suggesting that adaptive homeostatic mechanisms to ensure partial maintenance of the biophysical properties of membranes likely occur at a post-transcriptional level. PMID:27632198

  20. Plac8 is required for white adipocyte differentiation in vitro and cell number control in vivo.

    PubMed

    Jimenez-Preitner, Maria; Berney, Xavier; Thorens, Bernard

    2012-01-01

    Plac8 belongs to an evolutionary conserved family of proteins, mostly abundant in plants where they control fruit weight through regulation of cell number. In mice, Plac8 is expressed both in white and brown adipose tissues and we previously showed that Plac8(-/-) mice develop late-onset obesity, with abnormal brown fat differentiation and reduced thermogenic capacity. We also showed that in brown adipocytes, Plac8 is an upstream regulator of C/EBPβ expression. Here, we first assessed the role of Plac8 in white adipogenesis in vitro. We show that Plac8 is induced early after induction of 3T3-L1 adipocytes differentiation, a process that is prevented by Plac8 knockdown; similarly, embryonic fibroblasts obtained from Plac8 knockout mice failed to form adipocytes upon stimulation of differentiation. Knockdown of Plac8 in 3T3-L1 was associated with reduced expression of C/EBPβ, Krox20, and Klf4, early regulators of the white adipogenic program, and we show that Plac8 could transactivate the C/EBPβ promoter. In vivo, we show that absence of Plac8 led to increased white fat mass with enlarged adipocytes but reduced total number of adipocytes. Finally, even though Plac8(-/-) mice showed impaired thermogenesis due to brown fat dysfunction, this was not associated with changes in glycemia or plasma free fatty acid and triglyceride levels. Collectively, these data indicate that Plac8 is an upstream regulator of C/EBPβ required for adipogenesis in vitro. However, in vivo, Plac8 is dispensable for the differentiation of white adipocytes with preserved fat storage capacity but is required for normal fat cell number regulation.

  1. Phloretin promotes adipocyte differentiation in vitro and improves glucose homeostasis in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adipocyte dysfunction is associated with many metabolic diseases such as obesity, insulin resistance and diabetes. Previous studies found that phloretin promotes 3T3-L1 cells differentiation, but the underlying mechanisms for phloretin's effects on adipogenesis remain unclear. In this study, we demo...

  2. Inhibition of adipocyte differentiation and adipogenesis by the traditional Chinese herb Sibiraea angustata.

    PubMed

    Xiao, Lei; Zhang, Jun; Li, Hongxing; Liu, Jin; He, Lan; Zhang, Junjie; Zhai, Yonggong

    2010-12-01

    Obesity has become a major health concern due to its strong association with the metabolic syndrome. Inhibition of adipocyte differentiation represents a key strategy to inhibit obesity. Sibiraea angustata (SA), a traditional Chinese herb, has a wide range of pharmacological effects, such as improving digestive functions. Here, we report a novel antiadipogenic effect of SA. By using the SA water extract (SAW), SA acetic ether extract (SAA) and the 3T3-L1 model of adipocyte differentiation and adipogenesis, we showed that both SAW and SAA impaired the proliferation and adipo-differentiation of 3T3-L1 in a dose- and time-dependent manner. At the molecular level, treatment of 3T3-L1 cells with SAW or SAA inhibited the expression of the key adipocyte differentiation regulator CCAAT enhancer binding protein β (C/EBPβ), as well as peroxisome proliferator activated receptor γ, adipocyte protein-2, lipoprotein lipase and glucose transporter 4. Cell cycle analysis showed that both SAW and SAA blocked cell cycle at the G1-S transition phase, causing cells to remain in the preadipocyte state. The expression of CyclinA and cyclin-dependent kinase 2 was also inhibited by SAW and SAA. Treatment with SAW also prevented the localization of C/EBPβ to the centromeres. Taken together, our results show that SA has a potent antiadipogenic effect in 3T3-L1 cells due to the inhibition of adipocyte differentiation and adipogenesis. We propose that SA may be used as a safe and effective neutraceutical to manage obesity.

  3. Flow Cytometric Isolation and Differentiation of Adipogenic Progenitor Cells into Brown and Brite/Beige Adipocytes.

    PubMed

    Steinbring, Jochen; Graja, Antonia; Jank, Anne-Marie; Schulz, Tim J

    2017-01-01

    Aside from mature adipocytes, adipose tissue harbors several distinct cell populations including immune cells, endothelial cells, and adipogenic progenitor cells (AdPCs). AdPCs represent the reservoir of regenerative cells that replenishes adipocytes during normal cellular turnover and during times of increased demand for triglyceride-storage capacity. The worldwide increase in pathologies associated with the metabolic syndrome, such as obesity and type-2 diabetes, has heightened public and scientific interest in adipose tissues and the cell biological processes of adipose tissue formation and function. Two distinct types of fat cells are known: White and brown adipocytes. Especially brown adipose tissue (BAT) has received considerable attention due to its unique capacity for thermogenic energy expenditure and potential role in the treatment of adiposity. Accordingly, the cold-induced conversion of white into brown-like adipocytes has become a feasible approach in humans and a study-subject in rodents to better understand the underlying molecular processes. Fluorescence-activated cell sorting (FACS) provides a method to isolate AdPCs and other cell populations from adipose tissue by using antibodies detecting unique surface markers. We here describe an approach to isolate cells committed to the adipogenic lineage and summarize established protocols to differentiate FACS-purified primary AdPCs into UCP1-expressing brown adipocytes under in vitro conditions.

  4. Identification and characterization of an immunophilin expressed during the clonal expansion phase of adipocyte differentiation.

    PubMed Central

    Yeh, W C; Li, T K; Bierer, B E; McKnight, S L

    1995-01-01

    Mouse 3T3-L1 cells differentiate into fat-laden adipocytes in response to a cocktail of adipogenic hormones. This conversion process occurs in two discrete steps. During an early clonal expansion phase, confluent 3T3-L1 cells proliferate and express the products of the beta and delta members of the CCAAT/enhancer binding protein (C/EBP) family of transcription factors. The cells subsequently arrest mitotic growth, induce the expression of the alpha form of C/EBP, and acquire the morphology of fully differentiated adipocytes. Many of the genes induced during the terminal phase of adipocyte conversion are directly activated by C/EBP alpha, and gratuitous expression of this transcription factor is capable of catalyzing adipose conversion in a number of different cultured cell lines. The genetic program undertaken during the clonal expansion phase of 3T3-L1 differentiation, controlled in part by C/EBP beta and C/EBP delta, is less clearly understood. To study the molecular events occurring during clonal expansion, we have identified mRNAs that selectively accumulate during this phase of adipocyte conversion. One such mRNA encodes an immunophilin hereby designated FKBP51. In this report we provide the initial molecular characterization of FKBP51. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7479941

  5. A polyphenol rescues lipid induced insulin resistance in skeletal muscle cells and adipocytes.

    PubMed

    Gogoi, Bhaskarjyoti; Chatterjee, Priyajit; Mukherjee, Sandip; Buragohain, Alak Kumar; Bhattacharya, Samir; Dasgupta, Suman

    2014-09-26

    Skeletal muscle and adipose tissues are known to be two important insulin target sites. Therefore, lipid induced insulin resistance in these tissues greatly contributes in the development of type 2 diabetes (T2D). Ferulic acid (FRL) purified from the leaves of Hibiscus mutabilis, showed impressive effects in preventing saturated fatty acid (SFA) induced defects in skeletal muscle cells. Impairment of insulin signaling molecules by SFA was significantly waived by FRL. SFA markedly reduced insulin receptor β (IRβ) in skeletal muscle cells, this was affected due to the defects in high mobility group A1 (HMGA1) protein obtruded by phospho-PKCε and that adversely affects IRβ mRNA expression. FRL blocked PKCε activation and thereby permitted HMGA1 to activate IRβ promoter which improved IR expression deficiency. In high fat diet (HFD) fed diabetic rats, FRL reduced blood glucose level and enhanced lipid uptake activity of adipocytes isolated from adipose tissue. Importantly, FRL suppressed fetuin-A (FetA) gene expression, that reduced circulatory FetA level and since FetA is involved in adipose tissue inflammation, a significant attenuation of proinflammatory cytokines occurred. Collectively, FRL exhibited certain unique features for preventing lipid induced insulin resistance and therefore promises a better therapeutic choice for T2D.

  6. Antioxidant, anti-adipocyte differentiation, antitumor activity and anthelmintic activities against Anisakis simplex and Hymenolepis nana of yakuchinone A from Alpinia oxyphylla

    PubMed Central

    2013-01-01

    Background Alpinia oxyphylla is a common remedy in traditional Chinese medicine. Yakuchinone A is a major constituent of A. oxyphylla and exhibits anti-inflammatory, antitumor, antibacterial, and gastric protective activities. Methods Antioxidant and antitumor characteristics of yakuchinone A in skin cancer cells as well as novel mechanisms for the inhibition of adipocyte differentiation, cestocidal activities against Hymenolepis nana adults, and nematocidal activities against Anisakis simplex larvae are investigated. Results Yakuchinone A presents the ability of the removal of DPPH·and ABTS+ free radicals and inhibition of lipid peroxidation. Yakuchinone A suppresses intracellular lipid accumulation during adipocyte differentiation in 3 T3-L1 cells and the expressions of leptin and peroxisome proliferator-activated receptor γ (PPARγ). Yakuchinone A induces apoptosis and inhibits cell proliferation in skin cancer cells. The inhibition of cell growth by yakuchinone A is more significant for non-melanoma skin cancer (NMSC) cells than for melanoma (A375 and B16) and noncancerous (HaCaT and BNLCL2) cells. Treatment BCC cells with yakuchinone A shows down-regulation of Bcl-2, up-regulation of Bax, and an increase in cleavage poly (ADP-ribose) polymerase (PARP). This suggests that yakuchinone A induces BCC cells apoptosis through the Bcl-2-mediated signaling pathway. The anthelmintic activities of yakuchinone A for A. simplex are better than for H. nana. Conclusions In this work, yakuchinone A exhibits antioxidative properties, anti-adipocyte differentiation, antitumor activity, and anthelmintic activities against A. simplex and H. nana. PMID:24070160

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

    PubMed Central

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

    2008-01-01

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

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

    SciTech Connect

    Kim, Ki Young; Kim, Joo Young; Sung, Yoon-Young; Jung, Won Hoon; Kim, Hee-Youn; Park, Ji Seon; Cheon, Hyae Gyeong; Rhee, Sang Dal

    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.

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

    PubMed Central

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

    2015-01-01

    Obesity leads to adipose tissue inflammation that is characterized by increased release of proinflammatory molecules and the recruitment of activated immune cells. Although macrophages are present in the highest number among the immune cells in obese adipose tissue, not much is known about their direct interaction with adipocytes. We have introduced an ex vivo experimental system to characterize the cellular interactions and the profile of secreted cytokines in cocultures of macrophages and human adipocytes differentiated from either mesenchymal stem cells or a preadipocyte cell line. As observed by time-lapse microscopy, flow, and laser-scanning cytometry, macrophages phagocytosed bites of adipocytes (trogocytosis), which led to their de novo, phagocytosis and NF-κB-dependent synthesis, then release of interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1. IL-6 secretion was not accompanied by secretion of other proinflammatory cytokines, such as tumor necrosis factor (TNF)-α and IL-8, except MCP-1. LPS-induced release of TNF-α, IL-8 and MCP-1 was decreased in the presence of the differentiated adipocytes but the IL-6 level did not subside suggesting that phagocytosis-dependent IL-6 secretion may have significant regulatory function in the inflamed adipose tissue. PMID:25611388

  10. Lysophosphatidylcholine Acyltransferase 3 Is the Key Enzyme for Incorporating Arachidonic Acid into Glycerophospholipids during Adipocyte Differentiation

    PubMed Central

    Eto, Miki; Shindou, Hideo; Koeberle, Andreas; Harayama, Takeshi; Yanagida, Keisuke; Shimizu, Takao

    2012-01-01

    Cellular membranes contain glycerophospholipids, which have important structural and functional roles in cells. Glycerophospholipids are first formed in the de novo pathway (Kennedy pathway) and are matured in the remodeling pathway (Lands’ cycle). Recently, lysophospholipid acyltransferases functioning in Lands’ cycle were identified and characterized. Several enzymes involved in glycerophospholipid biosynthesis have been reported to have important roles in adipocytes. However, the role of Lands’ cycle in adipogenesis has not yet been reported. Using C3H10T1/2, a cell line capable of differentiating to adipocyte-like cells in vitro, changes of lysophospholipid acyltransferase activities were investigated. Lysophosphatidylcholine acyltransferase (LPCAT), lysophosphatidylethanolamine acyltransferase (LPEAT) and lysophosphatidylserine acyltransferase (LPSAT) activities were enhanced, especially with 18:2-CoA and 20:4-CoA as donors. Correspondingly, mRNA expression of LPCAT3, which possesses LPCAT, LPEAT and LPSAT activities with high specificity for 18:2- and 20:4-CoA, was upregulated during adipogenesis. Analysis of acyl-chain compositions of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS) showed a change in their profiles between preadipocytes and adipocytes, including an increase in the percentage of arachidonic acid-containing phospholipids. These changes are consistent with the activities of LPCAT3. Therefore, it is possible that enhanced phospholipid remodeling by LPCAT3 may be associated with adipocyte differentiation. PMID:23208369

  11. Vitisin A inhibits adipocyte differentiation through cell cycle arrest in 3T3-L1 cells

    SciTech Connect

    Kim, Soon-hee; Park, Hee-Sook; Lee, Myoung-su; Cho, Yong-Jin; Kim, Young-Sup; Hwang, Jin-Taek; Sung, Mi Jeong; Kim, Myung Sunny; Kwon, Dae Young

    2008-07-18

    Inhibition of adipocyte differentiation is one approach among the anti-obesity strategies. This study demonstrates that vitisin A, a resveratrol tetramer, inhibits adipocyte differentiation most effectively of 18 stilbenes tested. Fat accumulation and PPAR{gamma} expression were decreased by vitisin A in a dose-dependent manner. Vitisin A significantly inhibited preadipocyte proliferation and consequent differentiation within the first 2 days of treatment, indicating that the anti-adipogenic effect of vitisin A was derived from anti-proliferation. Based on cell cycle analysis, vitisin A blocked the cell cycle at the G1-S phase transition, causing cells to remain in the preadipocyte state. Vitisin A increased p21 expression, while the Rb phosphorylation level was reduced. Therefore, vitisin A seems to induce G1 arrest through p21- and consequent Rb-dependent suppression of transcription. On the other hand, ERK and Akt signaling pathways were not involved in the anti-mitotic regulation by vitisin A. Taken together, these results suggest that vitisin A inhibits adipocyte differentiation through preadipocyte cell cycle arrest.

  12. Reduction of adipogenesis and lipid accumulation by Taraxacum officinale (Dandelion) extracts in 3T3L1 adipocytes: an in vitro study.

    PubMed

    González-Castejón, Marta; García-Carrasco, Belén; Fernández-Dacosta, Raquel; Dávalos, Alberto; Rodriguez-Casado, Arantxa

    2014-05-01

    In this in vitro study, we have investigated the ability of Taraxacum officinale (dandelion) to inhibit adipocyte differentiation and lipogenesis in 3T3-L1 preadipocytes. HPLC analysis of the three plant extracts used in this study-leaf and root extracts and a commercial root powder-identified caffeic and chlorogenic acids as the main phenolic constituents. Oil Red O staining and triglyceride levels analysis showed decreased lipid and triglyceride accumulation, respectively. Cytotoxicity was assessed with the MTT assay showing non-toxic effect among the concentrations tested. DNA microarray analysis showed that the extracts regulated the expression of a number of genes and long non-coding RNAs that play a major role in the control of adipogenesis. Taken together, our results indicate that the dandelion extracts used in this study may play a significant role during adipogenesis and lipid metabolism, and thus, supporting their therapeutic interest as potential candidates for the treatment of obesity.

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

    PubMed

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

    2016-02-01

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

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

    PubMed

    Lee, Youngyi; Bae, Eun Ju

    2013-11-01

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

  15. Local renin angiotensin expression regulates human mesenchymal stem cell differentiation to adipocytes.

    PubMed

    Matsushita, Kenichi; Wu, Yaojiong; Okamoto, Yoshihisa; Pratt, Richard E; Dzau, Victor J

    2006-12-01

    Clinical and experimental evidence suggest that the renin-angiotensin system (RAS) plays a role in metabolic syndrome. Adipogenesis is suggested to modulate obesity and obesity-related consequences, such as metabolic syndrome. Although mesenchymal stem cells (MSCs) are a major source of adipocyte generation, the influence of RAS on MSC differentiation to adipocyte is unknown. We evaluated the expression of endogenous RAS in human MSCs during its differentiation to adipocytes and studied the effects of angiotensin II (Ang II), Ang II type 1 receptor blocker Valsartan, and type 2 (AT(2)) receptor blocker PD123319. Our data showed that differentiation was associated with an increase in cellular renin and AT(2) receptor expression and a concomitant decrease in angiotensinogen and angiotensin-converting enzyme expression. The net effect is an increase in endogenous cellular angiotensin II production. Incubation with Ang II (exogenous) inhibited adipogenesis. Combined treatment of exogenous Ang II and Valsartan further inhibited adipogenesis, whereas combined treatment of Ang II and PD123319 completely abolished the inhibition of adipogenesis, suggesting an important role for the AT(2) receptor. Blockade of endogenous angiotensin II effect by incubation with Valsartan alone inhibited adipogenesis, whereas PD123319 alone promoted adipogenesis, confirming the data using exogenous Ang II. The combination of Valsartan and PD123319 had no net effect. Our data demonstrate an important role of the expression of the local RAS in the regulation of human MSC differentiation to adipocytes. Elucidation of the molecular mechanism should provide important insight into the pathophysiology of the metabolic syndrome and the development of future therapeutics.

  16. 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

    PubMed Central

    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

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

    PubMed

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

    2012-12-01

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

  18. Endothelial Differentiation in Multipotent Cells Derived from Mouse and Human White Mature Adipocytes

    PubMed Central

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

    2012-01-01

    White mature adipocytes give rise to multipotent cells, so-called de-differentiated fat (DFAT) cells, when losing their fat in culture. The objective of this study was to examine the ability of DFAT cells to give rise to endothelial cells (ECs) in vitro and vivo. We demonstrate that mouse and human DFAT cells, derived from adipose tissue and lipospirate, respectively, initially lack expression of CD34, CD31, CD146, CD45 and pericyte markers, distinguishing them from progenitor cells previously identified in adipose stroma. The DFAT cells spontaneously differentiate into vascular ECs in vitro, as determined by real-time PCR, fluorescence activated cell sorting, immunostaining, and formation of tube structures. Treatment with bone morphogenetic protein (BMP)4 and BMP9, important in regulating angiogenesis, significantly enhance the EC differentiation. Furthermore, adipocyte-derived cells from Green Fluorescent Protein-transgenic mice were detected in the vasculature of infarcted myocardium up to 6 weeks after ligation of the left anterior descending artery in mice. We conclude that adipocyte-derived multipotent cells are able to spontaneously give rise to ECs, a process that is promoted by BMPs and may be important in cardiovascular regeneration and in physiological and pathological changes in fat and other tissues. PMID:22999861

  19. Like pigs, and unlike other breeds of cattle examined, mature Angus-derived adipocytes may extrude lipid prior to proliferation in vitro

    PubMed Central

    Wei, Shengjuan; Duarte, Marcio S.; Du, Min; Jiang, Zhihua; Paulino, Pedro V.R.; Chen, Jie; Fernyhough-Culver, Melinda; Hausman, Gary J.; Zan, Linsen; Dodson, Michael V.

    2012-01-01

    A large number of studies have shown that mature adipocytes are able to dedifferentiate in vitro into progeny cells, which possess proliferative capacity and mutilineage potential. Our present study confirms that mature adipocytes derived from Angus cattle also dedifferentiate into proliferative-competent progeny cells. However, this report is unlike any published for all other breeds of cattle we have worked with or that we have seen in published reports, in which mature adipocytes retain and distribute lipids into daughter cells symmetrically or asymmetrically. In the present work, we noted that Angus-derived mature adipocytes extruded a majority of their cellular lipid droplets prior to cell division. In this manner, these cells are processing lipid in a manner observed in mature adipocytes isolated from swine tissue. These results suggest that regulation of the mechanism(s) underlying lipid processing might be different between and within animal breeds. Lipid processing in beef-derived adipocytes during dedifferentiation may serve as a unique animal model for studying lipid metabolism during reverse adipogenesis. PMID:23700538

  20. Proinflammatory cytokines differentially regulate adipocyte mitochondrial metabolism, oxidative stress, and dynamics

    PubMed Central

    Hahn, Wendy S.; Kuzmicic, Jovan; Burrill, Joel S.; Donoghue, Margaret A.; Foncea, Rocio; Jensen, Michael D.; Lavandero, Sergio; Arriaga, Edgar A.

    2014-01-01

    Proinflammatory cytokines differentially regulate adipocyte mitochondrial metabolism, oxidative stress, and dynamics. Macrophage infiltration of adipose tissue and the chronic low-grade production of inflammatory cytokines have been mechanistically linked to the development of insulin resistance, the forerunner of type 2 diabetes mellitus. In this study, we evaluated the chronic effects of TNFα, IL-6, and IL-1β on adipocyte mitochondrial metabolism and morphology using the 3T3-L1 model cell system. TNFα treatment of cultured adipocytes led to significant changes in mitochondrial bioenergetics, including increased proton leak, decreased ΔΨm, increased basal respiration, and decreased ATP turnover. In contrast, although IL-6 and IL-1β decreased maximal respiratory capacity, they had no effect on ΔΨm and varied effects on ATP turnover, proton leak, or basal respiration. Only TNFα treatment of 3T3-L1 cells led to an increase in oxidative stress (as measured by superoxide anion production and protein carbonylation) and C16 ceramide synthesis. Treatment of 3T3-L1 adipocytes with cytokines led to decreased mRNA expression of key transcription factors and control proteins implicated in mitochondrial biogenesis, including PGC-1α and eNOS as well as deceased expression of COX IV and Cyt C. Whereas each cytokine led to effects on expression of mitochondrial markers, TNFα exclusively led to mitochondrial fragmentation and decreased the total level of OPA1 while increasing OPA1 cleavage, without expression of levels of mitofusin 2, DRP-1, or mitofilin being affected. In summary, these results indicate that inflammatory cytokines have unique and specialized effects on adipocyte metabolism, but each leads to decreased mitochondrial function and a reprogramming of fat cell biology. PMID:24595304

  1. Temporal profiling of the adipocyte proteome during differentiation using a 5-plex SILAC based strategy

    PubMed Central

    Ruch, Travis; Kim, Jae-Woo; Mortensen, Peter; Otto, Tamara; Nalli, Anuradha; Tang, Qi-Qun; Lane, M. Daniel; Chaerkady, Raghothama; Pandey, Akhilesh

    2008-01-01

    The adipose tissue has important secretory and endocrine functions in humans. The regulation of adipocyte differentiation has been actively pursued using transcriptomic methods over the last several years. Quantitative proteomics has emerged as a promising approach to obtain temporal profiles of biological processes such as differentiation. Stable isotope labeling with amino acids in cell culture (SILAC) is a simple and robust method for labeling proteins in vivo. Here, we describe the development and application of a five-plex SILAC experiment using four different heavy stable isotopic forms of arginine to study the nuclear proteome and the secretome during the course of adipocyte differentiation. Tandem mass spectrometry analysis using a quadrupole time-of-flight instrument resulted in identification of a total 882 proteins from these two proteomes. Of these proteins, 427 were identified on the basis of one or more arginine containing peptides that allowed quantitation. In addition to previously reported molecules that are differentially expressed during the process of adipogenesis (e.g. adiponectin and lipoprotein lipase), we identified several proteins whose differential expression during adipocyte differentiation has not been documented previously. For example, THO complex 4, a context-dependent transcriptional activator in the T-cell receptor alpha enhancer complex, showed highest expression at middle stage of adipogenesis while SNF2 alpha, a chromatin remodeling protein, was downregulated upon initiation of adipogenesis and remained so during subsequent time points. This study using a 5-plex SILAC to investigate dynamics illustrates the power of this approach to identify differentially expressed proteins in a temporal fashion. PMID:18947249

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

    PubMed

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

    2016-01-01

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

  3. Tocotrienol suppresses adipocyte differentiation and Akt phosphorylation in 3T3-L1 preadipocytes.

    PubMed

    Uto-Kondo, Harumi; Ohmori, Reiko; Kiyose, Chikako; Kishimoto, Yoshimi; Saito, Hisako; Igarashi, Osamu; Kondo, Kazuo

    2009-01-01

    In vivo studies show that alpha-tocotrienol and gamma-tocotrienol accumulate in adipose tissue. Furthermore, a recent study reports that the oral administration of gamma-tocotrienol from a tocotrienol-rich fraction from palm oil (TRF) decreases body fat levels in rats. The objective of this study was to evaluate the effect of TRF and its components on adipocyte differentiation in 3T3-L1 preadipocytes, which differentiated into adipocytes in the presence of 1.8 micromol/L insulin. TRF suppressed the insulin-induced mRNA expression of adipocyte-specific genes such as PPARgamma, adipocyte fatty acid-binding protein (aP2), and CCAAT/enhancer-binding protein-alpha (C/EBPalpha) compared with the differentiation of 3T3-L1 preadipocytes into adipocytes only in the presence of insulin. To confirm the suppressive effect of TRF, the major components of TRF, such as alpha-tocotrienol, gamma-tocotrienol, and alpha-tocopherol, were investigated. Alpha-tocotrienol and gamma-tocotrienol decreased the insulin-induced PPARgamma mRNA expression by 55 and 90%, respectively, compared with insulin, whereas alpha-tocopherol increased the mRNA expression. In addition, gamma-tocotrienol suppressed the insulin-induced aP2 and C/EBPalpha mRNA expression, triglyceride accumulation, and PPARgamma protein levels compared with insulin. The current results also revealed that gamma-tocotrienol inhibited the insulin-stimulated phosphorylation of Akt but not extracellular signal-regulated kinase (ERK)1/2 in the insulin signaling pathway of 3T3-L1 preadipocytes. Thus, the antiadipogenic effect of TRF depends on alpha-tocotrienol and gamma-tocotrienol, and gamma-tocotrienol may be a more potent inhibitor of adipogenesis than alpha-tocotrienol. Therefore, the results of this study suggest that tocotrienol suppresses insulin-induced differentiation and Akt phosphorylation in 3T3-L1 preadipocytes. Furthermore, tocotrienol could act as an antiadipogenic vitamin in the nutrient-mediated regulation of body

  4. Extract of Chaga mushroom (Inonotus obliquus) stimulates 3T3-L1 adipocyte differentiation.

    PubMed

    Joo, Jeong In; Kim, Dong Hyun; Yun, Jong Won

    2010-11-01

    Chaga mushroom (Inonotus obliquus) has long been used as a folk medicine due to its numerous biological functions such as antibacterial, antiallergic, antiinflammatory and antioxidative activities. In the present study, it was found that the I. obliquus hot water extract (IOWE) activated adipogenesis of 3T3-L1 preadipocytes. Even in the absence of adipogenic stimuli by insulin, the IOWE strongly induced adipogenesis of 3T3-L1 preadipocytes. The major constituent of IOWE was glucose-rich polysaccharides with a molecular mass of 149  kDa. IOWE enhanced the differentiation of 3T3-L1 preadipocytes, increasing TG (triacylglycerol) accumulation that is critical for acquisition of the adipocyte phenotype, in a dose-dependent manner. IOWE stimulated gene expression of C/EBPα (CCAAT/enhancer-binding protein α) and PPARγ (peroxisome proliferator-activated receptors γ) during adipocyte differentiation, and induced the expression of PPARγ target genes such as aP2 (adipocyte protein 2), LPL (lipoprotein lipase) and CD36 (fatty acid translocase). Immunoblot analysis revealed that IOWE increased the expression of adipogenic makers such as PPARγ and GLUT4 (glucose transporter 4). The luciferase reporter assay demonstrated that IOWE did not exhibit PPARγ ligand activity. Although these results require further investigation, the ability of natural mushroom product to increase PPARγ transcriptional activities may be expected to be therapeutic targets for dyslipidemia and type 2 diabetes.

  5. Polymerase I and transcript release factor (PTRF) regulates adipocyte differentiation and determines adipose tissue expandability

    PubMed Central

    Perez-Diaz, Sergio; Johnson, Lance A.; DeKroon, Robert M.; Moreno-Navarrete, Jose M.; Alzate, Oscar; Fernandez-Real, Jose M.; Maeda, Nobuyo; Arbones-Mainar, Jose M.

    2014-01-01

    Impaired adipogenesis renders an adipose tissue unable to expand, leading to lipotoxicity and conditions such as diabetes and cardiovascular disease. While factors important for adipogenesis have been studied extensively, those that set the limits of adipose tissue expansion remain undetermined. Feeding a Western-type diet to apolipoprotein E2 knock-in mice, a model of metabolic syndrome, produced 3 groups of equally obese mice: mice with normal glucose tolerance, hyperinsulinemic yet glucose-tolerant mice, and prediabetic mice with impaired glucose tolerance and reduced circulating insulin. Using proteomics, we compared subcutaneous adipose tissues from mice in these groups and found that the expression of PTRF (polymerase I and transcript release factor) associated selectively with their glucose tolerance status. Lentiviral and pharmacologically overexpressed PTRF, whose function is critical for caveola formation, compromised adipocyte differentiation of cultured 3T3-L1cells. In human adipose tissue, PTRF mRNA levels positively correlated with markers of lipolysis and cellular senescence. Furthermore, a negative relationship between telomere length and PTRF mRNA levels was observed in human subcutaneous fat. PTRF is associated with limited adipose tissue expansion underpinning the key role of caveolae in adipocyte regulation. Furthermore, PTRF may be a suitable adipocyte marker for predicting pathological obesity and inform clinical management.—Perez-Diaz, S., Johnson, L. A., DeKroon, R. M., Moreno-Navarrete, J. M., Alzate, O., Fernandez-Real, J. M., Maeda, N., Arbones-Mainar, J. M. Polymerase I and transcript release factor (PTRF) regulates adipocyte differentiation and determines adipose tissue expandability. PMID:24812087

  6. Human white adipocytes convert into "rainbow" adipocytes in vitro.

    PubMed

    Maurizi, Giulia; Poloni, Antonella; Mattiucci, Domenico; Santi, Spartaco; Maurizi, Angela; Izzi, Valerio; Giuliani, Angelica; Mancini, Stefania; Zingaretti, Maria Cristina; Perugini, Jessica; Severi, Ilenia; Falconi, Massimo; Vivarelli, Marco; Rippo, Maria Rita; Corvera, Silvia; Giordano, Antonio; Leoni, Pietro; Cinti, Saverio

    2016-12-17

    White adipocytes are plastic cells able to reversibly transdifferentiate into brown adipocytes and into epithelial glandular cells under physiologic stimuli in vivo. These plastic properties could be used in future for regenerative medicine, but are incompletely explored in their details. Here, we focused on plastic properties of human mature adipocytes (MA) combining gene expression profile through microarray analysis with morphologic data obtained by electron and time lapse microscopy. Primary MA showed the classic morphology and gene expression profile of functional mature adipocytes. Notably, despite their committed status, MA expressed high levels of reprogramming genes. MA from ceiling cultures underwent transdifferentiation towards fibroblast-like cells with a well-differentiated morphology and maintaining stem cell gene signatures. The main morphologic aspect of the transdifferentiation process was the secretion of large lipid droplets and the development of organelles necessary for exocrine secretion further supported the liposecretion process. Of note, electron microscope findings suggesting liposecretion phenomena were found also in explants of human fat and rarely in vivo in fat biopsies from obese patients. In conclusion, both MA and post-liposecretion adipocytes show a well-differentiated phenotype with stem cell properties in line with the extraordinary plasticity of adipocytes in vivo. This article is protected by copyright. All rights reserved.

  7. RBM4a-regulated splicing cascade modulates the differentiation and metabolic activities of brown adipocytes

    PubMed Central

    Lin, Jung-Chun; Lu, Yi-Han; Liu, Yun-Ru; Lin, Ying-Ju

    2016-01-01

    RNA-binding motif protein 4a (RBM4a) reportedly reprograms splicing profiles of the insulin receptor (IR) and myocyte enhancer factor 2C (MEF2C) genes, facilitating the differentiation of brown adipocytes. Using an RNA-sequencing analysis, we first compared the gene expressing profiles between wild-type and RBM4a−/− brown adipocytes. The ablation of RBM4a led to increases in the PTBP1, PTBP2 (nPTB), and Nova1 proteins, whereas elevated RBM4a reduced the expression of PTBP1 and PTBP2 proteins in brown adipocytes through an alternative splicing-coupled nonsense-mediated decay mechanism. Subsequently, RBM4a indirectly shortened the half-life of the Nova1 transcript which was comparatively stable in the presence of PTBP2. RBM4a diminished the influence of PTBP2 in adipogenic development by reprogramming the splicing profiles of the FGFR2 and PKM genes. These results constitute a mechanistic understanding of the RBM4a-modulated splicing cascade during the brown adipogenesis. PMID:26857472

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

    SciTech Connect

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

    2010-04-02

    Human mesenchymal stem cells (hMSCs) derived from bone marrow are multipotent stem cells that can regenerate mesenchymal tissues such as adipose, bone or muscle. It is thought that hMSCs can be utilized as a cell resource for tissue engineering and as human models to study cell differentiation mechanisms, such as adipogenesis, osteoblastogenesis and so on. Since it takes 2-3 weeks for hMSCs to differentiate into adipocytes using conventional culture methods, the development of methods to induce faster differentiation into adipocytes is required. In this study we optimized the culture conditions for adipocyte induction to achieve a shorter cultivation time for the induction of adipocyte differentiation in bone marrow-derived hMSCs. Briefly, we used a cocktail of dexamethasone, insulin, methylisobutylxanthine (DIM) plus a peroxisome proliferator-activated receptor {gamma} agonist, rosiglitazone (DIMRo) as a new adipogenic differentiation medium. We successfully shortened the period of cultivation to 7-8 days from 2-3 weeks. We also found that rosiglitazone alone was unable to induce adipocyte differentiation from hMSCs in vitro. However, rosiglitazone appears to enhance hMSC adipogenesis in the presence of other hormones and/or compounds, such as DIM. Furthermore, the inhibitory activity of TGF-{beta}1 on adipogenesis could be investigated using DIMRo-treated hMSCs. We conclude that our rapid new culture method is very useful in measuring the effect of molecules that affect adipogenesis in hMSCs.

  9. α-Mangostin Improves Glucose Uptake and Inhibits Adipocytes Differentiation in 3T3-L1 Cells via PPARγ, GLUT4, and Leptin Expressions

    PubMed Central

    Taher, Muhammad; Mohamed Amiroudine, Mohamed Zaffar Ali; Tengku Zakaria, Tengku Muhamad Faris Syafiq; Ichwan, Solachuddin J. A.; Kaderi, Mohd Arifin; Ahmed, Qamar Uddin; Zakaria, Zainul Amiruddin

    2015-01-01

    Obesity has been often associated with the occurrence of cardiovascular diseases, type 2 diabetes, and cancer. The development of obesity is also accompanied by significant differentiation of preadipocytes into adipocytes. In this study, we investigated the activity of α-mangostin, a major xanthone component isolated from the stem bark of G. malaccensis, on glucose uptake and adipocyte differentiation of 3T3-L1 cells focusing on PPARγ, GLUT4, and leptin expressions. α-Mangostin was found to inhibit cytoplasmic lipid accumulation and adipogenic differentiation. Cells treated with 50 μM of α-mangostin reduced intracellular fat accumulation dose-dependently up to 44.4% relative to MDI-treated cells. Analyses of 2-deoxy-D-[3H] glucose uptake activity showed that α-mangostin significantly improved the glucose uptake (P < 0.05) with highest activity found at 25 μM. In addition, α-mangostin increased the amount of free fatty acids (FFA) released. The highest glycerol release level was observed at 50 μM of α-mangostin. qRT-PCR analysis showed reduced lipid accumulation via inhibition of PPARγ gene expression. Induction of glucose uptake and free fatty acid release by α-mangostin were accompanied by increasing mRNA expression of GLUT4 and leptin. These evidences propose that α-mangostin might be possible candidate for the effective management of obesity in future. PMID:25873982

  10. Dietary vitamin A restriction affects adipocyte differentiation and fatty acid composition of intramuscular fat in Iberian pigs.

    PubMed

    Ayuso, M; Óvilo, C; Rodríguez-Bertos, A; Rey, A I; Daza, A; Fenández, A; González-Bulnes, A; López-Bote, C J; Isabel, B

    2015-10-01

    The aim of this study was to investigate whether dietary vitamin A level is associated with differences in adipocyte differentiation or lipid accumulation in Iberian pigs at early growing (35.8kg live weight) and at finishing (158kg live weight). Iberian pigs of 16.3kg live weight were allocated to two feeding groups, one group received 10,000IU of vitamin A/kg diet (control); the other group received a diet with 0IU of vitamin A (var) for the whole experimental period. The dietary vitamin A level had no effect on growth performance and carcass traits. The early suppression of vitamin A increased the preadipocyte number in Longissimus thoracis (LT) muscle in the early growth period (P<0.001) and the neutral lipid content and composition (higher MUFA and lower SFA content) at the end of the finishing period (P<0.05). Vitamin A restriction in young pigs increases their lipogenic potential without affecting carcass traits.

  11. The Kampo medicines Orengedokuto, Bofutsushosan and Boiogito have different activities to regulate gene expressions in differentiated rat white adipocytes: comprehensive analysis of genetic profiles.

    PubMed

    Yamakawa, Jun-ichi; Ishigaki, Yasuhito; Takano, Fumihide; Takahashi, Takashi; Yoshida, Junko; Moriya, Junji; Takata, Takanobu; Tatsuno, Takanori; Sasaki, Kenroh; Ohta, Tomihisa; Takegami, Tsutomu; Yoshizaki, Fumihiko

    2008-11-01

    Three Kampo medicines, Boiogito (BOT), Bofutsushosan (BTS) and Orengedokuto (OGT), used for obese patients were investigated for their effects on adipogenesis in cultured rat white adipocytes. Administration of the three extracts suppressed adipogenesis in concentration-dependent manners (1-100 microg/ml) without any cytotoxicity. Changes in mRNA expression levels were analyzed using a Rat 230 2.0 Affymetrix GeneChip microarray system. DNA microarray analysis (total probe set: 31099) using cDNAs prepared from adipocytes revealed that BOT, BTS and OGT increased the expression of 133-150 genes and decreased the expression of 42-110 genes by > or =2-fold. We identified 329 downregulated genes and 189 upregulated genes among a total set of 514 probes (overlap: 4). Overall, genes related to cellular movement, cell death, cell growth/differentiation and immune responses were the most downregulated, while those related to lipid metabolism and cell signaling were the most upregulated. Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assays were conducted to confirm the microarray results. Analysis of the clustering profiles of the microarray results revealed that BOT and BTS changed the expression levels of similar genes mainly involved in small molecule biochemistry and cell differentiation, while OGT altered 10 genes related to lipid metabolism, in contrast to the effects of BOT and BTS. We also measured mRNA expression levels of seven selected genes highly contributing to the lipid metabolism by using semiquantitative RT-PCR assay, that were acetyl-Coenzyme A carboxylase alpha (ACACA), AE binding protein 1 (AEBP1), patatin-like phospholipase domain containing 8 (PNPLA8), secretoglobin (SCGB1A1), adrenergic (ADRB3), adiponectin (ADIPOQ), monoglyceride lipase (MGLL). Beta-actin (ACTB) gene was used as an endogenous internal standard. The present findings indicate that these three herbal extracts have the potential to prevent adipogenesis in rat

  12. The role of prolyl hydroxylase domain protein (PHD) during rosiglitazone-induced adipocyte differentiation.

    PubMed

    Kim, Juyoung; Kwak, Hyun Jeong; Cha, Ji-Young; Jeong, Yun-Seung; Rhee, Sang Dahl; Cheon, Hyae Gyeong

    2014-01-31

    Rosiglitazone, a well known insulin sensitizer, stimulates adipocyte differentiation via the activation of peroxisome proliferator-activated receptor γ (PPARγ). Previous two-dimensional proteomics studies using C3H10T1/2 murine mesenchymal pluripotent stem cells revealed that prolyl hydroxylase domain protein (PHD) levels significantly increased during rosiglitazone-induced adipocyte differentiation (RIAD). In this study, we investigated the functional role played by PHD during RIAD. Three PHD isoforms (PHD1, 2, and 3) were found to be up-regulated in C3H10T1/2 cells during RIAD, whereas PHD knockdown and treatment with PHD inhibitors (dimethyloxalyl glycine or ethyl-3,4-dihydroxybenzoate) blocked RIAD. PHD inhibition was found to be associated with increases in the levels of anti-adipogenic proteins such as GATA-3, KLF-2, and transcriptional coactivator with PDZ binding motif (TAZ), with their reduced ubiquitination, suggesting that PHDs evoke the ubiquitination/proteasomal degradation of anti-adipogenic proteins. On the other hand, MG-132 (a proteasomal inhibitor) prevented the degradation of anti-adipogenic proteins and retarded RIAD. PPARγ antagonists (bisphenol A diglycidyl ether or GW9662) blunted the effects of rosiglitazone on PHD regulation. Furthermore, putative PPARγ binding sites were identified in the promoter region of PHDs by ChIP-PCR, implying that rosiglitazone may induce PHD up-regulation directly by PPARγ activation. Consistent with in vitro results, oral administration of rosiglitazone to ob/ob mice for 2 weeks increased adipose PHD levels and decreased anti-adipogenic protein levels by increasing their ubiquitination. These results suggest that rosiglitazone increases PHD expression in a PPARγ-dependent manner and that this leads to the commitment of anti-adipogenic proteins to the ubiquitination-proteasomal pathway and to the subsequent induction of adipocyte differentiation.

  13. Adipocyte and adipogenesis.

    PubMed

    Ali, Aus Tariq; Hochfeld, Warren E; Myburgh, Renier; Pepper, Michael S

    2013-01-01

    Adipocytes are the main constituent of adipose tissue and are considered to be a corner stone in the homeostatic control of whole body metabolism. Their primary function is to control energy balance by storing triacylglycerol in periods of energy excess and mobilizing it during energy deprivation. Besides the classical function of storing fat, adipocytes secrete numerous lipid and protein factors. Collectively they are considered to constitute a major endocrine organ which has a profound impact on the metabolism of other tissues, the regulation of appetite, insulin sensitivity, immunological responses and vascular disease. Adipogenesis is the process during which fibroblast like preadipocytes developed into mature adipocytes. Adipogenesis is a well-orchestrated multistep process that requires the sequential activation of numerous transcription factors, including the CCAAT/enhancer-binding protein (C/EBP) gene family and peroxisome proliferator activated receptor-γ (PPAR-γ). In order to reach maturity, these cells must go through two vital steps: adipocyte determination and adipocyte differentiation. Although many of the molecular details of adipogenesis are still unknown, several factors involved in this processes have been identified. Some stimulators include peroxisome proliferator-activated receptor γ (PPAR γ), insulin-like growth factor I (IGF-l), macrophage colony stimulating factor, fatty acids, prostaglandins and glucocorticoids. Inhibitors include glycoproteins, transforming growth factor-β (TGF-β), inflammatory cytokines and growth hormone. Beside these factors, there are others for example age, gender and life style that may affect this process in one way or another. An increase in the number and size of adipocytes causes white adipose tissue (WAT) to expand and this can lead to obesity. Adipogenesis can lead to central obesity if it occurs in the abdominal fat depot and peripheral obesity if it occurs in subcutaneous tissue.

  14. Multilocular adipocytes from muscovy ducklings differentiated in response to cold acclimation.

    PubMed Central

    Barré, H; Cohen-Adad, F; Duchamp, C; Rouanet, J L

    1986-01-01

    Morphological and functional aspects of adipose tissue from 6-week-old cold-acclimated muscovy ducklings reared at 4 degrees C ambient temperature (Ta) from the age of 1 week were examined for the occurrence of brown adipose tissue (b.a.t.) in order to explain non-shivering thermogenesis (n.s.t.) observed at this age. Metabolic rate and integrated muscle electrical activity (e.m.g.) were measured at different Ta (from -10 to +28 degrees C) in cold-acclimated and in control ducklings reared at thermoneutrality. The results confirm the existence of n.s.t. in 6-week-old cold-acclimated muscovy ducklings. In cold-acclimated ducklings, typical multilocular adipocytes were found in subcutaneous adipose deposits instead of the unilocular white adipocytes as in control ducklings. Mitochondria isolated from this differentiated tissue were less abundant than in b.a.t. of mammals. Their respiration rate was similar to the respiration rate of white adipose tissue mitochondria from control rats and much lower than the b.a.t. mitochondria rate from cold-acclimated rats. It is therefore unlikely that this differentiated adipose tissue contributes to the n.s.t. observed, an n.s.t. whose capacity reached 5.26 W/kg (+73.5% above resting metabolic rate) in cold-acclimated ducklings. The role of this differentiated adipose tissue in the metabolic adaptation to cold is discussed. Images Plate 4 Plate 1 Plate 2 Plate 3 PMID:3795059

  15. Cyanidin-3-glucoside derived from black soybeans ameliorate type 2 diabetes through the induction of differentiation of preadipocytes into smaller and insulin-sensitive adipocytes.

    PubMed

    Matsukawa, Toshiya; Inaguma, Tetsuya; Han, Junkyu; Villareal, Myra O; Isoda, Hiroko

    2015-08-01

    Black soybean is a health food has been reported to have antidiabetes effect. The onset of diabetes is closely associated with adipocyte differentiation, and at present, the effect of black soybean on adipocyte differentiation is unknown. Here, we investigated the antidiabetes effect of black soybean, and its anthocyanin cyanidin-3-glucoside (Cy3G), on adipocyte differentiation. Orally administered black soybean seed coat extract (BSSCE) reduced the body and white adipose tissue (WAT) weight of db/db mice accompanied by a decrease in the size of adipocytes in WAT. Furthermore, 3T3-Ll cells treated with BSSCE and Cy3G were observed to differentiate into smaller adipocytes which correlated with increased PPARγ and C/EBPα gene expressions, increased adiponectin secretion, decreased tumor necrosis factor-α secretion, activation of insulin signalling and increased glucose uptake. C2C12 myotubes cultured with conditioned medium, obtained from 3T3-L1 adipocyte cultures treated with Cy3G, also showed significantly increased expression of PGC-1α, SIRT1 and UCP-3 genes. Here we report that BSSCE, as well as its active compound Cy3G, has antidiabetes effects on db/db mice by promoting adipocyte differentiation. This notion is supported by BSSCE and Cy3G inducing the differentiation of 3T3-L1 preadipocytes into smaller, insulin-sensitive adipocytes, and it induced the activation of skeletal muscle metabolism. This is the first report on the modulation effect of Cy3G on adipocyte differentiation.

  16. Ivy gourd (Coccinia grandis L. Voigt) root suppresses adipocyte differentiation in 3T3-L1 cells

    PubMed Central

    2014-01-01

    Background Ivy gourd (Coccinia grandis L. Voigt) is a tropical plant widely distributed throughout Asia, Africa, and the Pacific Islands. The anti-obesity property of this plant has been claimed but still remains to be scientifically proven. We therefore investigated the effects of ivy gourd leaf, stem, and root on adipocyte differentiation by employing cell culture model. Methods Dried roots, stems, and leaves of ivy gourd were separately extracted with ethanol. Each extract was then applied to 3T3-L1 pre-adipocytes upon induction with a mixture of insulin, 3-isobutyl-1-methylxanthine, and dexamethasone, for anti-adipogenesis assay. The active extract was further fractionated by a sequential solvent partitioning method, and the resulting fractions were examined for their abilities to inhibit adipogenesis in 3T3-L1 cells. Differences in the expression of adipogenesis-related genes between the treated and untreated cells were determined from their mRNA and protein levels. Results Of the three ivy gourd extracts, the root extract exhibited an anti-adipogenic effect. It significantly reduced intracellular fat accumulation during the early stages of adipocyte differentiation. Together with the suppression of differentiation, expression of the genes encoding PPARγ, C/EBPα, adiponectin, and GLUT4 were down-regulated. Hexane-soluble fraction of the root extract also inhibited adipocyte differentiation and decreased the mRNA levels of various adipogenic genes in the differentiating cells. Conclusions This is the first study to demonstrate that ivy gourd root may prevent obesity based mainly on the ability of its active constituent(s) to suppress adipocyte differentiation in vitro. Such an inhibitory effect is mediated by at least down-regulating the expression of PPARγ-the key transcription factor of adipogenesis in pre-adipocytes during their early differentiation processes. PMID:24884680

  17. Brazilein from Caesalpinia sappan L. Antioxidant Inhibits Adipocyte Differentiation and Induces Apoptosis through Caspase-3 Activity and Anthelmintic Activities against Hymenolepis nana and Anisakis simplex.

    PubMed

    Liang, Chia-Hua; Chan, Leong-Perng; Chou, Tzung-Han; Chiang, Feng-Yu; Yen, Chuan-Min; Chen, Pin-Ju; Ding, Hsiou-Yu; Lin, Rong-Jyh

    2013-01-01

    Brazilein, a natural, biologically active compound from Caesalpinia sappan L., has been shown to exhibit anti-inflammatory and antioxidant properties and to inhibit the growth of several cancer cells. This study verifies the antioxidant and antitumor characteristics of brazilein in skin cancer cells and is the first time to elucidate the inhibition mechanism of adipocyte differentiation, cestocidal activities against Hymenolepis nana, and reduction of spontaneous movement in Anisakis simplex. Brazilein exhibits an antioxidant capacity as well as the ability to scavenge DPPH(•) and ABTS(•+) free radicals and to inhibit lipid peroxidation. Brazilein inhibited intracellular lipid accumulation during adipocyte differentiation in 3T3-L1 cells and suppressed the induction of peroxisome proliferator-activated receptor γ (PPAR γ ), the master regulator of adipogenesis, suggesting that brazilein presents the antiobesity effects. The toxic effects of brazilein were evaluated in terms of cell viability, induction of apoptosis, and the activity of caspase-3 in BCC cells. The inhibition of the growth of skin cancer cells (A431, BCC, and SCC25) by brazilein is greater than that of human skin malignant melanoma (A375) cells, mouse leukemic monocyte macrophage (RAW 264.7 cells), and noncancerous cells (HaCaT and BNLCL2 cells). The anthelmintic activities of brazilein against Hymenolepis nana are better than those of Anisakis simplex.

  18. Brazilein from Caesalpinia sappan L. Antioxidant Inhibits Adipocyte Differentiation and Induces Apoptosis through Caspase-3 Activity and Anthelmintic Activities against Hymenolepis nana and Anisakis simplex

    PubMed Central

    Liang, Chia-Hua; Chan, Leong-Perng; Chou, Tzung-Han; Chiang, Feng-Yu; Yen, Chuan-Min; Chen, Pin-Ju; Ding, Hsiou-Yu

    2013-01-01

    Brazilein, a natural, biologically active compound from Caesalpinia sappan L., has been shown to exhibit anti-inflammatory and antioxidant properties and to inhibit the growth of several cancer cells. This study verifies the antioxidant and antitumor characteristics of brazilein in skin cancer cells and is the first time to elucidate the inhibition mechanism of adipocyte differentiation, cestocidal activities against Hymenolepis nana, and reduction of spontaneous movement in Anisakis simplex. Brazilein exhibits an antioxidant capacity as well as the ability to scavenge DPPH• and ABTS•+ free radicals and to inhibit lipid peroxidation. Brazilein inhibited intracellular lipid accumulation during adipocyte differentiation in 3T3-L1 cells and suppressed the induction of peroxisome proliferator-activated receptor γ (PPARγ), the master regulator of adipogenesis, suggesting that brazilein presents the antiobesity effects. The toxic effects of brazilein were evaluated in terms of cell viability, induction of apoptosis, and the activity of caspase-3 in BCC cells. The inhibition of the growth of skin cancer cells (A431, BCC, and SCC25) by brazilein is greater than that of human skin malignant melanoma (A375) cells, mouse leukemic monocyte macrophage (RAW 264.7 cells), and noncancerous cells (HaCaT and BNLCL2 cells). The anthelmintic activities of brazilein against Hymenolepis nana are better than those of Anisakis simplex. PMID:23554834

  19. 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.

    PubMed

    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.

  20. [Molecular Mechanisms of Early-stage Adipocyte Differentiation and Multi-functional Roles of Newly Isolated Adipogenic Factors].

    PubMed

    Imagawa, Masayoshi

    2016-01-01

    Obesity is a major risk factor for diabetes, hypertension, hyperlipidemia, and arteriosclerosis. Although the middle and late stages of adipocyte differentiation are well characterized, the earliest step in the differentiation process has remained largely unknown. We isolated 102 genes expressed at the beginning of the differentiation of a mouse preadipocyte cell line, 3T3-L1 cells. Because approximately half of these genes were unknown, we named them factor for adipocyte differentiation (fad) genes. I first show how these genes regulate the early stage of adipocyte differentiation. We next generated fad104-deficient mice, and demonstrated that fad104-deficient mice died due to cyanosis-associated lung dysplasia with atelectasis. We also found that fad104 positively regulated adipocyte differentiation and negatively regulated osteoblast differentiation. We then demonstrated that fad24-knockdown inhibited mitotic clonal expansion (MCE) and that FAD24 contributed to the regulation of DNA replication by recruiting histone acetyltransferase binding to ORC1 (HBO1) to DNA replication origins. In vitro culture experiments revealed that fad24-null embryos developed normally to the morula stage, but acquired growth defects in subsequent stages. These results strongly suggest that fad24 is essential for pre-implantation in embryonic development, particularly for progression to the blastocyst stage. These findings together indicate that both fad104 and fad24 contribute not only to adipogenesis but also to other physiological events. The multi-functional roles of these genes are discussed.

  1. Hedgehog associated to microparticles inhibits adipocyte differentiation via a non-canonical pathway

    PubMed Central

    Fleury, Audrey; Hoch, Lucile; Martinez, M. Carmen; Faure, Hélène; Taddei, Maurizio; Petricci, Elena; Manetti, Fabrizio; Girard, Nicolas; Mann, André; Jacques, Caroline; Larghero, Jérôme; Ruat, Martial; Andriantsitohaina, Ramaroson; Le Lay, Soazig

    2016-01-01

    Hedgehog (Hh) is a critical regulator of adipogenesis. Extracellular vesicles are natural Hh carriers, as illustrated by activated/apoptotic lymphocytes specifically shedding microparticles (MP) bearing the morphogen (MPHh+). We show that MPHh+ inhibit adipocyte differentiation and orientate mesenchymal stem cells towards a pro-osteogenic program. Despite a Smoothened (Smo)-dependency, MPHh+ anti-adipogenic effects do not activate a canonical Hh signalling pathway in contrast to those elicited either by the Smo agonist SAG or recombinant Sonic Hedgehog. The Smo agonist GSA-10 recapitulates many of the hallmarks of MPHh+ anti-adipogenic effects. The adipogenesis blockade induced by MPHh+ and GSA-10 was abolished by the Smo antagonist LDE225. We further elucidate a Smo/Lkb1/Ampk axis as the non-canonical Hh pathway used by MPHh+ and GSA-10 to inhibit adipocyte differentiation. Our results highlight for the first time the ability of Hh-enriched MP to signal via a non-canonical pathway opening new perspectives to modulate fat development. PMID:27010359

  2. WEHI-3 cells inhibit adipocyte differentiation in 3T3-L1 cells

    SciTech Connect

    Lai, Jing; Liu, Gexiu; Yan, Guoyao; He, Dongmei; Zhou, Ying; Chen, Shengting

    2015-06-26

    By investigating the anti-adipogenic effects of WEHI-3 cells – a murine acute myelomonocytic leukemia cell line – we sought to improve the efficiency of hematopoietic stem cell transplantation (HSCT). Analysis of Oil Red O staining and the expression of adipogenic genes, including PPARγ, C/EBPα, FAS and LPL, indicated that WEHI-3 cells significantly inhibited 3T3-L1 mouse preadipocyte cells from differentiating into adipocytes. In vivo, fat vacuoles in mice injected with WEHI-3 cells were also remarkably reduced in the murine bone marrow pimelosis model. Moreover, the key gene in the Rho signaling pathway, ROCKII, and the key gene in the Wnt signaling pathway, β-catenin, were both upregulated compared with the control group. siRNA-mediated knockdown of ROCKII and β-catenin reversed these WEHI-3-mediated anti-adipogenic effects. Taken together, these data suggest that WEHI-3 cells exert anti-adipogenic effects and that both ROCKII and β-catenin are involved in this process. - Highlights: • WEHI-3, an acute myelomonocytic leukemia cell line, inhibited 3T3-L1 preadipocyte from differentiating into adipocyte. • WEHI-3 cells can arrest 3T3-L1 cells in G0/G1 phase by secreting soluble factors and thus inhibit their proliferation. • WEHI-3 cells reduced bone marrow pimelosis in the murine model. • Both ROCKII and β-catenin were involved in the WEHI-3-mediated anti-adipogenic effects.

  3. Berberine inhibits 3T3-L1 adipocyte differentiation through the PPARgamma pathway.

    PubMed

    Huang, Cheng; Zhang, Yuebo; Gong, Zhenwei; Sheng, Xiaoyan; Li, Zongmeng; Zhang, Wei; Qin, Ying

    2006-09-22

    Berberine (BBR), a compound purified from Cortidis rhizoma, reduces serum cholesterol, triglycerides, and LDL-cholesterol of hypercholesterolemic patients and high fat diet fed animals, and increases hepatic LDLR mRNA and protein levels through a post-transcriptional mechanism. BBR also enhances the hypoglycemic action of insulin in diabetic animal models. Here, we show that BBR inhibits the differentiation of 3T3-L1 preadipocytes induced by DM and suppresses the mitotic clonal expansion of 3T3-L1 preadipocytes in a time- and dose-dependent manner. Gene expression analysis and Western blot analysis reveal that the BBR inhibits the mRNA and protein levels of adipogenesis related transcription factors PPARgamma and C/EBPalpha and their upstream regulator, C/EBPbeta. Reporter gene assays demonstrate that the full-length PPARgamma and alpha transcription activities are inhibited by BBR. Using real-time PCR, we have also found that the PPAR target genes that are involved in adipocyte differentiation, such as aP2, CD36, ACO, LPL, and other adipocyte markers, are suppressed by BBR. These studies suggest that BBR works on multiple molecular targets as an inhibitor of PPARgamma and alpha, and is a potential weight reducing, hypolipidemic, and hypoglycemic drug.

  4. Platyphylloside Isolated From Betula platyphylla Inhibit Adipocyte Differentiation and Induce Lipolysis Via Regulating Adipokines Including PPARγ in 3T3-L1 Cells

    PubMed Central

    Lee, Mina; Sung, Sang Hyun

    2016-01-01

    Background: Obesity causes or aggravates many health problems, both independently and in association with several pathological disorders, including Type II diabetes, hypertension, atherosclerosis, and cancer. Therefore, we screened small compounds isolated from natural products for the development of anti-obesity drugs. Objective: The purpose of this study was to investigate the anti-adipogenic activities of platyphylloside, diarylheptanoid isolated from Betula platyphylla, which was selected based on the screening using 3T3-L1 cells. Materials and Methods: To evaluate the inhibition of adipocyte differentiation and lipolysis, lipid contents of BPP on were measured using Oil Red O staining in 3T3-L1 cells. The mRNA and protein expression levels of various adipokines were measured by Quantitative real-time PCR and Western blotting analysis, respectively. Results: Platyphylloside showed significant inhibitory activity on adipocyte differentiation in 3T3-L1 cells and suppressed adipocyte differentiation even in the presence of troglitazone, a PPARγ agonist. Platyphylloside might suppress adipocyte differentiation through PPARγ, C/EBPα, and SREBP1-induced adipogenesis, which is synergistically associated with downstream adipocyte-specific gene promoters such as aP2, FAS, SCD-1, LPL, and Adiponectin. In addition, platyphylloside affected lipolysis by down-regulating perilipin and HSL and up-regulating TNFα. Conclusion: Taken together, the results reveal that platyphylloside has anti-adipogenic activity and highlight its potential in the prevention and treatment of obesity. SUMMARY The extract of B. platyphylla bark and its isolate, BPP, had anti-adipogenic activity in 3T3-L1 cells via suppression of adipocyte differentiation from preadipocytes.Treatment with BPP significantly down-regulated the expression of PPARγ, C/EBP, C/EBPβ, C/EBPδ, SREBP1c, SCD-1, FAS, aP2 and LPL.BPP induced a lipolytic response in mature adipocytes via up-regulation krof TNFá and down

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

    PubMed Central

    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

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

    PubMed

    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.

  7. Ubiquitin Ligase NEDD4 Regulates PPARγ Stability and Adipocyte Differentiation in 3T3-L1 Cells

    PubMed Central

    Li, Jing Jing; Wang, Ruishan; Lama, Rati; Wang, Xinjiang; Floyd, Z. Elizabeth; Park, Edwards A.; Liao, Francesca-Fang

    2016-01-01

    Peroxisome proliferator–activated receptor-γ (PPARγ) is a ligand-activated nuclear receptor which controls lipid and glucose metabolism. It is also the master regulator of adipogenesis. In adipocytes, ligand-dependent PPARγ activation is associated with proteasomal degradation; therefore, regulation of PPARγ degradation may modulate its transcriptional activity. Here, we show that neural precursor cell expressed developmentally down-regulated protein 4 (NEDD4), an E3 ubiquitin ligase, interacts with the hinge and ligand binding domains of PPARγ and is a bona fide E3 ligase for PPARγ. NEDD4 increases PPARγ stability through the inhibition of its proteasomal degradation. Knockdown of NEDD4 in 3T3-L1 adipocytes reduces PPARγ protein levels and suppresses adipocyte conversion. PPARγ correlates positively with NEDD4 in obese adipose tissue. Together, these findings support NEDD4 as a novel regulator of adipogenesis by modulating the stability of PPARγ. PMID:27917940

  8. Shikonin suppresses ERK 1/2 phosphorylation during the early stages of adipocyte differentiation in 3T3-L1 cells

    PubMed Central

    2013-01-01

    Background The naphthoquinone pigment, shikonin, is a major component of Lithospermum erythrorhizon and has been shown to have various biological functions, including antimicrobial, anti-inflammatory, and antitumor effects. In this study, we investigated the effect of shikonin on adipocyte differentiation and its mechanism of action in 3T3-L1 cells. Methods To investigate the effects of shikonin on adipocyte differentiation, 3T3-L1 cells were induced to differentiate using 3-isobutyl-1-methylzanthine, dexamethasone, and insulin (MDI) for 8 days in the presence of 0–2 μM shikonin. Oil Red O staining was performed to determine the lipid accumulation in 3T3-L1 cells. To elucidate the anti-adipogenic mechanism of shikonin, adipogenic transcription factors, the phosphorylation levels of ERK, and adipogenic gene expression were analyzed by Western blotting and quantitative real-time PCR. To further confirm that shikonin inhibits adipogenic differentiation through downregulation of ERK 1/2 activity, 3T3-L1 cells were treated with shikonin in the presence of FGF-2, an activator, or PD98059, an inhibitor, of the ERK1/2 signaling pathway. Results Shikonin effectively suppressed adipogenesis and downregulated the protein levels of 2 major transcription factors, PPARγ and C/EBPα, as well as the adipocyte specific gene aP2 in a dose-dependent manner. qRT-PCR analysis revealed that shikonin inhibited mRNA expression of adipogenesis-related genes, such as PPARγ, C/EBPα, and aP2. Adipocyte differentiation was mediated by ERK 1/2 phosphorylation, which was confirmed by pretreatment with PD98059 (an ERK 1/2 inhibitor) or FGF-2 (an ERK 1/2 activator). The phosphorylation of ERK1/2 during the early stages of adipogenesis in 3T3-L1 cells was inhibited by shikonin. We also confirmed that FGF-2-stimulated ERK 1/2 activity was attenuated by shikonin. Conclusions These results demonstrate that shikonin inhibits adipogenic differentiation via suppression of the ERK signaling pathway

  9. The endocrine disruptor diethylstilbestrol induces adipocyte differentiation and promotes obesity in mice

    SciTech Connect

    Hao, Chan-Juan; Cheng, Xue-Jia; Xia, Hong-Fei Ma, Xu

    2012-08-15

    Epidemiology studies indicate that exposure to endocrine disruptors during developmental “window” contributes to adipogenesis and the development of obesity. Implication of endocrine disruptor such as diethylstilbestrol (DES) on adipose tissue development has been poorly investigated. Here we evaluated the effects of DES on adipocyte differentiation in vitro and in vivo, and explored potential mechanism involved in its action. DES induced 3T3-L1 preadipocyte differentiation in a dose-dependent manner, and activated the expression of estrogen receptor (ER) and peroxisome proliferator-acivated receptor (PPAR) γ as well as its target genes required for adipogenesis in vitro. ER mediated the enhancement of DES-induced PPARγ activity. Moreover, DES perturbed key regulators of adipogenesis and lipogenic pathway in vivo. In utero exposure to low dose of DES significantly increased body weight, liver weight and fat mass in female offspring at postnatal day (PND) 60. In addition, serum triglyceride and glucose levels were also significantly elevated. These results suggest that perinatal exposure to DES may be expected to increase the incidence of obesity in a sex-dependent manner and can act as a potential chemical stressor for obesity and obesity-related disorders. -- Highlights: ► DES induced adipocyte differentiation in a dose-dependent manner in 3T3-L1 cells. ► DES activated adipogenic critical regulators and markers in vitro and in vivo. ► Perinatal exposure to DES led to the obese phenotype in female offspring. ► DES might be a potential chemical stressor for obesity and obesity-related disorders.

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

    PubMed Central

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

    2016-01-01

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

  11. Isolation and Culture of Pig Spermatogonial Stem Cells and Their in Vitro Differentiation into Neuron-Like Cells and Adipocytes.

    PubMed

    Wang, Xiaoyan; Chen, Tingfeng; Zhang, Yani; Li, Bichun; Xu, Qi; Song, Chengyi

    2015-11-04

    Spermatogonial stem cells (SSCs) renew themselves throughout the life of an organism and also differentiate into sperm in the adult. They are multipopent and therefore, can be induced to differentiate into many cells types in vitro. SSCs from pigs, considered an ideal animal model, are used in studies of male infertility, regenerative medicine, and preparation of transgenic animals. Here, we report on a culture system for porcine SSCs and the differentiation of these cells into neuron-like cells and adipocytes. SSCs and Sertoli cells were isolated from neonatal piglet testis by differential adhesion and SSCs were cultured on a feeder layer of Sertoli cells. Third-generation SSCs were induced to differentiate into neuron-like cells by addition of retinoic acid, β-mercaptoethanol, and 3-isobutyl-1-methylxanthine (IBMX) to the induction media and into adipocytes by the addition of hexadecadrol, insulin, and IBMX to the induction media. The differentiated cells were characterized by biochemical staining, qRT-PCR, and immunocytochemistry. The cells were positive for SSC markers, including alkaline phosphatase and SSC-specific genes, consistent with the cells being undifferentiated. The isolated SSCs survived on the Sertoli cells for 15 generations. Karyotyping confirmed that the chromosomal number of the SSCs were normal for pig (2n = 38, n = 19). Pig SSCs were successfully induced into neuron-like cells eight days after induction and into adipocytes 22 days after induction as determined by biochemical and immunocytochemical staining. qPCR results also support this conclusion. The nervous tissue markers genes, Nestin and β-tubulin, were expressed in the neuron-like cells and the adipocyte marker genes, PPARγ and C/EBPα, were expressed in the adipocytes.

  12. PKC-ALDH2 Pathway Plays a Novel Role in Adipocyte Differentiation

    PubMed Central

    Yu, Yu-Hsiang; Liao, Pei-Ru; Guo, Chien-Jung; Chen, Che-Hong; Mochly-Rosen, Daria; Chuang, Lee-Ming

    2016-01-01

    The ALDH2 gene encodes the mitochondrial aldehyde dehydrogenase 2 (ALDH2), a critical enzyme involved in ethanol clearance through acetaldehyde metabolism. ALDH2 also catalyzes the metabolism of other bioreactive aldehydes, including propionaldehyde, butyraldehyde, and 4-hydroxykenals (4-HNE). Increased levels of 4-HNE in adipose tissue positively correlate with obesity and insulin resistance. However, it remains unclear whether ALDH2 is involved in regulation of adipocyte differentiation. Here, we found that ALDH2 protein levels were lower in white adipose tissue of high-fat diet-fed mice and ob/ob mice relative to lean mice. Knockdown of ALDH2 expression in 3T3-L1 preadipocytes caused an increase in intracellular 4-HNE, thereby attenuated adipocyte differentiation. By contrast, an ALDH2 activator, Alda-1, significantly accelerated adipogenesis, which was accompanied by an increase in adipogenic gene expression. Consistently, adipogenesis was reduced when protein kinase C ε (PKCε), an ALDH2 phosphorylating activator, was silenced in 3T3-L1 preadipocytes, whereas treatment with a PKCε agonist in 3T3-L1 preadipocytes enhanced adipogenesis. Whole-genome microarray profiling of Alda-1-treated cells demonstrated several upregulated transcripts encoding proteins involved in metabolism and the majority of these transcripts are for proteins involved in PPAR signaling pathways. Furthermore, PKCε-ALDH2 interaction alleviates 4-HNE induced aberrant PPARγ regulation on adipogenesis. Taken together, these results demonstrate that ALDH2 activation enhances adipogenesis and signaling pathways involving PPARγ. Thus, activation of PKCε-ALDH2 regulatory axis may be a therapeutic target for treating obesity and type 2 diabetes. PMID:27575855

  13. Estrogen-related receptor alpha modulates the expression of adipogenesis-related genes during adipocyte differentiation.

    PubMed

    Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Yagi, Ken; Okazaki, Yasushi; Inoue, Satoshi

    2007-07-06

    Estrogen-related receptor alpha (ERRalpha) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in fatty acid oxidation and mitochondrial biogenesis in brown adipose tissue. However, the physiological role of ERRalpha in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERRalpha and ERRalpha-related transcriptional coactivators, peroxisome proliferator-activated receptor gamma (PPARgamma) coactivator-1alpha (PGC-1alpha) and PGC-1beta, can be up-regulated in 3T3-L1 preadipocytes at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. Gene knockdown by ERRalpha-specific siRNA results in mRNA down-regulation of fatty acid binding protein 4, PPARgamma, and PGC-1alpha in 3T3-L1 cells in the adipogenesis medium. ERRalpha and PGC-1beta mRNA expression can be also up-regulated in another preadipocyte lineage DFAT-D1 cells and a pluripotent mesenchymal cell line C3H10T1/2 under the differentiation condition. Furthermore, stable expression of ERRalpha in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERRalpha may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes.

  14. Suppressive Effects of Barley β-Glucans with Different Molecular Weight on 3T3-L1 Adipocyte Differentiation.

    PubMed

    Zhu, Yingying; Yao, Yang; Gao, Yue; Hu, Yibo; Shi, Zhenxing; Ren, Guixing

    2016-03-01

    In this study, 2 β-glucans with different molecular weight were prepared and purified from hull-less barley bran. The aim was to evaluate their effects on the differentiation of 3T3-L1 pre-adipocytes. Results showed that barley β-glucans inhibited the differentiation of 3T3-L1 pre-adipocytes induced by differentiation medium in a dose-dependent manner, the suppressive effect of high-molecular-weight barley β-glucans (552 kDa, BGH) was stronger (P < 0.05) than that of low-molecular-weight barley β-glucan (32 kDa, BGL), evidenced by the significantly decrease (P < 0.05) of Oil-red O staining and intracellular triglyceride content in the mature adipocytes. Besides, gene expression analysis and Western Blot analysis revealed that both BGH and BGL inhibited the mRNA and protein levels of adipogenesis related transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT-enhancer-binding protein α (C/EBPα) which are principal regulators of adipogenesis. Furthermore, the mRNA and protein expression levels of PPARγ target genes in adipose tissue including adipocyte fatty acid binding protein (ap2), lipoprotein lipase (LPL), uncoupling protein-2 (UCP-2), and glucose-transporter 4 (Glut4) in 3T3-L1 cells was also markedly downregulated (P < 0.05). These findings were anticipated to help develop barley β-glucans based functional food for the management of obesity.

  15. Actions of β-apo-carotenoids in differentiating cells: differential effects in P19 cells and 3T3-L1 adipocytes.

    PubMed

    Wang, Cynthia X; Jiang, Hongfeng; Yuen, Jason J; Lee, Seung-Ah; Narayanasamy, Sureshbabu; Curley, Robert W; Harrison, Earl H; Blaner, William S

    2015-04-15

    β-Apo-carotenoids, including β-apo-13-carotenone and β-apo-14'-carotenal, are potent retinoic acid receptor (RAR) antagonists in transactivation assays. We asked how these influence RAR-dependent processes in living cells. Initially, we explored the effects of β-apo-13-carotenone and β-apo-14'-carotenal on P19 cells, a mouse embryonal carcinoma cell line that differentiates into neurons when treated with all-trans-retinoic acid. Treatment of P19 cells with either compound failed to block all-trans-retinoic acid induced differentiation. Liquid chromatography tandem mass spectrometry studies, however, established that neither of these β-apo-carotenoids accumulates in P19 cells. All-trans-retinoic acid accumulated to high levels in P19 cells. This suggests that the uptake and metabolism of β-apo-carotenoids by some cells does not involve the same processes used for retinoids and that these may be cell type specific. We also investigated the effects of two β-apo-carotenoids on 3T3-L1 adipocyte marker gene expression during adipocyte differentiation. Treatment of 3T3-L1 adipocytes with either β-apo-13-carotenone or β-apo-10'-carotenoic acid, which lacks RAR antagonist activity, stimulated adipocyte marker gene expression. Neither blocked the inhibitory effects of a relatively large dose of exogenous all-trans-retinoic acid on adipocyte differentiation. Our data suggest that in addition to acting as transcriptional antagonists, some β-apo-carotenoids act through other mechanisms to influence 3T3-L1 adipocyte differentiation.

  16. St. John's wort promotes adipocyte differentiation and modulates NF-κB activation in 3T3-L1 cells.

    PubMed

    Hatano, Tomoko; Sameshima, Yuka; Kawabata, Mami; Yamada, Shizuo; Shinozuka, Kazumasa; Nakabayashi, Toshikatsu; Mizuno, Hideya

    2014-01-01

    St. John's wort (SJW), or Hypericum perforatum, is a perennial herb that has been used in the treatment of depression in several countries. Though its therapeutic effect on depression has been extensively studied, its influence on metabolic syndrome is yet to be fully characterized. Therefore, we investigated the effect of SJW extract on adipocyte differentiation and its anti-inflammatory effects by using 3T3-L1 preadipocytes. Oil Red O staining indicated that SJW promotes adipocyte differentiation, while immunoblots indicated that SJW increases the expression of peroxisome proliferator activated receptor γ (PPARγ), a nuclear receptor regulating adipocyte differentiation, and adiponectin, an anti-inflammatory adipokine. Furthermore, the anti-inflammatory activity of SJW was demonstrated by its inhibition of the activation of nuclear factor-κB (NF-κB), an inflammatory transcription factor. Stimulation of mature 3T3-L1 adipocytes by tumor necrosis factor-α (TNF-α) decreased the expression of the NF-κB inhibitor IκBα, and increased its phosphorylation. Treatment with SJW further decreased the TNF-α-induced perturbation in IκBα expression and phosphorylation, which indicated that SJW mediated the inhibition of NF-κB activation. In addition, SJW decreased the TNF-α-induced increase in the mRNA levels of pro-inflammatory adipokines, interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1). Collectively, our results indicate that SJW treatment could promote adipocyte differentiation probably through its anti-inflammatory activity, which in turn suggests that SJW has the potential to minimize the risk factors of metabolic syndrome.

  17. Parabens inhibit fatty acid amide hydrolase: A potential role in paraben-enhanced 3T3-L1 adipocyte differentiation.

    PubMed

    Kodani, Sean D; Overby, Haley B; Morisseau, Christophe; Chen, Jiangang; Zhao, Ling; Hammock, Bruce D

    2016-11-16

    Parabens are a class of small molecules that are regularly used as preservatives in a variety of personal care products. Several parabens, including butylparaben and benzylparaben, have been found to interfere with endocrine signaling and to stimulate adipocyte differentiation. We hypothesized these biological effects could be due to interference with the endocannabinoid system and identified fatty acid amide hydrolase (FAAH) as the direct molecular target of parabens. FAAH inhibition by parabens yields mixed-type and time-independent kinetics. Additionally, structure activity relationships indicate FAAH inhibition is selective for the paraben class of compounds and the more hydrophobic parabens have higher potency. Parabens enhanced 3T3-L1 adipocyte differentiation in a dose dependent fashion, different from two other FAAH inhibitors URB597 and PF622. Moreover, parabens, URB597 and PF622 all failed to enhance AEA-induced differentiation. Furthermore, rimonabant, a cannabinoid receptor 1 (CB1)-selective antagonist, did not attenuate paraben-induced adipocyte differentiation. Thus, adipogenesis mediated by parabens likely occurs through modulation of endocannabinoids, but cell differentiation is independent of direct activation of CB1 by endocannabinoids.

  18. The proteomic analysis of an adipocyte differentiated from human mesenchymal stem cells using two-dimensional gel electrophoresis.

    PubMed

    Lee, Hyun-Kyung; Lee, Byung-Hyo; Park, Seung-Ah; Kim, Chan-Wha

    2006-02-01

    Adipose tissues play a crucial endocrine role in the control of whole body glucose homeostasis and insulin sensitivity. Considering the current substantial rise in obesity and obesity-related diseases, including diabetes, it is important to understand the molecular basis of adipocyte differentiation and its control. In this study, we have analyzed the protein expression inherent to adipogenic differentiation, by 2-DE, MALDI-TOF, and RT-PCR. This study focused on proteins that were differentially expressed by the differentiation of human mesenchymal stem cells (hMSCs) to adipocytes. We conducted 2-DE for each set of proteins in the cytosol of adipocytes that had differentiated from hMSC, in a pH range from 3-10. Thirty-two protein spots were shown to have different expression levels. Among these, eight up-regulated proteins were identified by MALDI-TOF/MS, as the following: syntaxin binding protein 3, OSBP-related protein 3, phosphodiesterase, glycophorin, immunoglobulin kappa chain variable region, peroxisome proliferative activated receptor gamma (PPAR-gamma), bA528A10.3.1 (novel protein similar to KIAA01616, isoform 1), and T cell receptor V-beta 4. Four proteins: syntaxin-3, OSBP-related protein 3, PPAR-gamma and glycophorin were associated with adipogenesis.

  19. A dynamic CTCF chromatin binding landscape promotes DNA hydroxymethylation and transcriptional induction of adipocyte differentiation

    PubMed Central

    Dubois-Chevalier, Julie; Oger, Frédérik; Dehondt, Hélène; Firmin, François F.; Gheeraert, Céline; Staels, Bart; Lefebvre, Philippe; Eeckhoute, Jérôme

    2014-01-01

    CCCTC-binding factor (CTCF) is a ubiquitously expressed multifunctional transcription factor characterized by chromatin binding patterns often described as largely invariant. In this context, how CTCF chromatin recruitment and functionalities are used to promote cell type-specific gene expression remains poorly defined. Here, we show that, in addition to constitutively bound CTCF binding sites (CTS), the CTCF cistrome comprises a large proportion of sites showing highly dynamic binding patterns during the course of adipogenesis. Interestingly, dynamic CTCF chromatin binding is positively linked with changes in expression of genes involved in biological functions defining the different stages of adipogenesis. Importantly, a subset of these dynamic CTS are gained at cell type-specific regulatory regions, in line with a requirement for CTCF in transcriptional induction of adipocyte differentiation. This relates to, at least in part, CTCF requirement for transcriptional activation of both the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARG) and its target genes. Functionally, we show that CTCF interacts with TET methylcytosine dioxygenase (TET) enzymes and promotes adipogenic transcriptional enhancer DNA hydroxymethylation. Our study reveals a dynamic CTCF chromatin binding landscape required for epigenomic remodeling of enhancers and transcriptional activation driving cell differentiation. PMID:25183525

  20. Synthesis of mitochondrial uncoupling protein in brown adipocytes differentiated in cell culture

    SciTech Connect

    Kopecky, J.; Baudysova, M.; Zanotti, F.; Janikova, D.; Pavelka, S.; Houstek, J. )

    1990-12-25

    In order to characterize the biogenesis of unique thermogenic mitochondria of brown adipose tissue, differentiation of precursor cells isolated from mouse brown adipose tissue was studied in cell culture. Synthesis of mitochondrial uncoupling protein (UCP), F1-ATPase, and cytochrome oxidase was examined by L-(35S)methionine labeling and immunoblotting. For the first time, synthesis of physiological amounts of the UCP, a key and tissue-specific component of thermogenic mitochondria, was observed in cultures at about confluence (day 6), indicating that a complete differentiation of brown adipocytes was achieved in vitro. In postconfluent cells (day 8) the content of UCP decreased rapidly, in contrast to some other mitochondrial proteins (beta subunit of F1-ATPase, cytochrome oxidase). In these cells, it was possible, by using norepinephrine, to induce specifically the synthesis of the UCP but not of F1-ATPase or cytochrome oxidase. The maximal response was observed at 0.1 microM norepinephrine and the synthesis of UCP remained activated for at least 24 h. Detailed analysis revealed a major role of the beta-adrenergic receptors and elevated intracellular concentration of cAMP in stimulation of UCP synthesis. A quantitative recovery of the newly synthesized UCP in the mitochondrial fraction indicated completed biogenesis of functionally competent thermogenic mitochondria.

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

    PubMed

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

    2014-05-01

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

  2. Estrogen-related receptor {alpha} modulates the expression of adipogenesis-related genes during adipocyte differentiation

    SciTech Connect

    Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Yagi, Ken; Okazaki, Yasushi; Inoue, Satoshi . E-mail: INOUE-GER@h.u-tokyo.ac.jp

    2007-07-06

    Estrogen-related receptor {alpha} (ERR{alpha}) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in fatty acid oxidation and mitochondrial biogenesis in brown adipose tissue. However, the physiological role of ERR{alpha} in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERR{alpha} and ERR{alpha}-related transcriptional coactivators, peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) coactivator-1{alpha} (PGC-1{alpha}) and PGC-1{beta}, can be up-regulated in 3T3-L1 preadipocytes at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. Gene knockdown by ERR{alpha}-specific siRNA results in mRNA down-regulation of fatty acid binding protein 4, PPAR{gamma}, and PGC-1{alpha} in 3T3-L1 cells in the adipogenesis medium. ERR{alpha} and PGC-1{beta} mRNA expression can be also up-regulated in another preadipocyte lineage DFAT-D1 cells and a pluripotent mesenchymal cell line C3H10T1/2 under the differentiation condition. Furthermore, stable expression of ERR{alpha} in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERR{alpha} may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes.

  3. Cinnamaldehyde prevents adipocyte differentiation and adipogenesis via regulation of peroxisome proliferator-activated receptor-γ (PPARγ) and AMP-activated protein kinase (AMPK) pathways.

    PubMed

    Huang, Bo; Yuan, Hai Dan; Kim, Do Yeon; Quan, Hai Yan; Chung, Sung Hyun

    2011-04-27

    Cinnamaldehyde (CA), one of the active components of cinnamon, has been known to exert several pharmacological effects such as anti-inflammatory, antioxidant, antitumor, and antidiabetic activities. However, its antiobesity effect has not been reported yet. This study investigated the antidifferentiation effect of CA on 3T3-L1 preadipocytes, and the antiobesity activity of CA was further explored using high-fat-diet-induced obese ICR mice. During 3T3-L1 preadipocytes were differentiated into adipocytes, 10-40 μM CA was treated and lipid contents were quantified by Oil Red O staining, along with changes in the expression of genes and proteins associated with adipocyte differentiation and adipogenesis. It was found that CA significantly reduced lipid accumulation and down-regulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding proteins α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1) in concentration-dependent manners. Moreover, CA markedly up-regulated AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC), and these effects were blunted in the presence of AMPK inhibitor, compound C. In the animal study, weight gains, insulin resistance index, plasma triglyceride (TG), nonesterified fatty acid (NEFA), and cholesterol levels in the 40 mg/kg of CA-administered group were significantly decreased by 67.3, 55, 39, 31, and 23%, respectively, when compared to the high-fat diet control group. In summary, these results suggest that CA exerts antiadipogenic effects through modulation of the PPAR-γ and AMPK signaling pathways.

  4. miR-148a is Associated with Obesity and Modulates Adipocyte Differentiation of Mesenchymal Stem Cells through Wnt Signaling

    PubMed Central

    Shi, Chunmei; Zhang, Min; Tong, Meiling; Yang, Lei; Pang, Lingxia; Chen, Ling; Xu, Guangfeng; Chi, Xia; Hong, Qin; Ni, Yuhui; Ji, Chenbo; Guo, Xirong

    2015-01-01

    Obesity results from numerous, interacting genetic, behavioral, and physiological factors. Adipogenesis is partially regulated by several adipocyte-selective microRNAs (miRNAs) and transcription factors that regulate proliferation and differentiation of human adipose-derived mesenchymal stem cells (hMSCs-Ad). In this study, we examined the roles of adipocyte-selective miRNAs in the differentiation of hMSCs-Ad to adipocytes. Results showed that the levels of miR-148a, miR-26b, miR-30, and miR-199a increased in differentiating hMSCs-Ad. Among these miRNAs, miR-148a exhibited significant effects on increasing PPRE luciferase activity (it represents PPAR-dependent transcription, a major factor in adipogenesis) than others. Furthermore, miR-148a expression levels increased in adipose tissues from obese people and mice fed high-fat diet. miR-148a acted by suppressing its target gene, Wnt1, an endogenous inhibitor of adipogenesis. Ectopic expression of miR-148a accelerated differentiation and partially rescued Wnt1-mediated inhibition of adipogenesis. Knockdown of miR-148a also inhibited adipogenesis. Analysis of the upstream region of miR-148a locus identified a 3 kb region containing a functional cAMP-response element-binding protein (CREB) required for miR-148a expression in hMSCs-Ad. The results suggest that miR-148a is a biomarker of obesity in human subjects and mouse model, which represents a CREB-modulated miRNA that acts to repress Wnt1, thereby promoting adipocyte differentiation. PMID:26001136

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

    SciTech Connect

    Kang, Seong-Il; Ko, Hee-Chul; Shin, Hye-Sun; Kim, Hyo-Min; Hong, Youn-Suk; Lee, Nam-Ho; Kim, Se-Jae

    2011-06-17

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

  6. Differentiation to adipocytes in accompanied by an increase in the amounts of Gi- and Go-proteins in 3T3-L1 cells

    SciTech Connect

    Watkins, D.C.; Northup, J.K.; Malbon, C.C.

    1986-05-01

    Treatment of cultures of 3T3-L1 cells with methylisobutyl-xanthine and dexamethasone has been shown to result in accumulation of lipid and conversion to the morphology of adipocytes in more than 90% of the cells. The status of the stimulatory (Gs), inhibitory (Gi) and Go-proteins during the course of 3T3-L1 differentiation was examined. The amount of alpha subunit of Gs (..cap alpha..Gs), assayed by radiolabeling in the presence of cholera toxin and (/sup 32/P)NAD/sup +/, increased upon differentiation as previously described by others. The amounts of ..cap alpha..Gi and ..cap alpha..Go assayed by radiolabeling in the presence of pertussis toxin and (/sup 32/P)NAD/sup +/ increased 3-fold upon differentiation. Immunoblots of cell membranes subjected to gel electrophoresis in sodium dodecyl sulfate were probed with two rabbit antisera raised against bovine brain ..cap alpha..Go and with one raised against the..beta..-subunit of the bovine rod-outer-segment G-protein, referred to as transducin. The immunoblotting data confirm the increase upon differentiation of ..cap alpha..Go and also demonstrate an increase in the amount of the ..beta..-subunit. Thus differentiation of 3T3-L1 cells is accompanied by dramatic changes in the complexion of G-proteins in the membranes.

  7. Inhibition of preadipocyte differentiation and lipid accumulation by Orengedokuto treatment of 3T3-L1 cultures.

    PubMed

    Ikarashi, Nobutomo; Tajima, Masataka; Suzuki, Kunihiro; Toda, Takahiro; Ito, Kiyomi; Ochiai, Wataru; Sugiyama, Kiyoshi

    2012-01-01

    Obesity is a major cause of metabolic syndrome and is due to an increase in the number and hypertrophy of adipocytes. Accordingly, inhibition of the differentiation and proliferation of adipocytes may be used in the treatment and prevention of metabolic syndrome. This study investigated the effects of 50 commonly used Kampo medicines on the differentiation of 3T3-L1 preadipocytes to search for a drug with an antiobesity effect. Kampo medicines were screened, and the strongest differentiation-inhibitory effect was noted with Orengedokuto. To explore the active ingredients in Orengedokuto, the effects of four crude drug components of Orengedokuto were investigated. It was found that the differentiation-inhibitory effect of Orengedokuto was accounted for by Coptidis rhizome and Phellodendri cortex. Furthermore, berberine, a principal ingredient common to Coptidis rhizome and Phellodendri cortex, showed a differentiation-inhibitory effect. The effect of berberine involves an inhibition of the mRNA and protein expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα). Moreover, berberine inhibited lipid accumulation in adipocytes. These findings suggest that an antiobesity effect could be a new indication for Orengedokuto and that its active ingredient is berberine, with a mechanism involving the inhibition of PPARγ and C/EBPα expression.

  8. 3T3 cells in adipocytic conversion.

    PubMed

    O'Shea Alvarez, M S

    1991-01-01

    3T3 are murine cells of an established heteroploid cellular line. Some clones of this cellular line, when cultured under adequate conditions differentiate into adipocytes. During the process of differentiation, the cells undergo a change from the elongated fibroblastic shape to a round or oval form and accumulate small drops of lipids within their cytoplasma. These lipid drops fuse into one large drop which displaces the nucleus towards the periphery, giving the cell the aspect of a mature adipocyte of white adipose tissue. The cells not only change their morphology, but they also present important biochemical changes. They show a simultaneous increase in triglyceride synthesis and activity of lipogenic enzymes. There is also an increase in the response of the activity of various hormones and the de novo synthesis of the receptors to such hormones, as insulin and ACTH. During the process of differentiation important changes occur in the synthesis of various proteins, such as actin, tubulin, and other proteins which also make up the cellular cytoskeleton, forming part of the lipid transportation within the adipose cell. The adipocytic differentiation of 3T3 cells depends on adipogenic serum factors used in the supplementary culture medium. These adipogenic factors seem to play an important role in the development of adipose tissue. There are hormones, chemical agents and serum factors which modulate adipocytic differentiation. The clone must be susceptible to adipocytic differentiation, it must reach a quiescent state and find itself in adipogenic conditions for the 3T3 cells to differentiate into adipocytes. It must also carry out an DNA synthesis which is an expression of the new phenotype. The differentiation of 3T3 cells in terminal. The fact that these cells present an adipocytic conversion under physiologic conditions and with adipogenic hormones which exist in the whole animal has been demonstrated. All of these characteristics show that the 3T3 cells may be

  9. TNF-alpha inhibits 3T3-L1 adipocyte differentiation without downregulating the expression of C/EBPbeta and delta.

    PubMed

    Kurebayashi, S; Sumitani, S; Kasayama, S; Jetten, A M; Hirose, T

    2001-04-01

    Tumor necrosis factor-alpha (TNF-alpha) has been reported to inhibit adipocyte differentiation in which multiple transcription factors including CCAAT enhancer binding proteins (C/EBPs) and peroxisome proliferator-activated receptor (PPAR) gamma play an important role. Induction of C/EBPalpha and PPARgamma, which regulate the expression of many adipocyte-related genes, is dependent on the expression of C/EBPbeta and C/EBPdelta at the early phase of adipocyte differentiation. To elucidate the mechanism by which TNF-alpha inhibits adipocyte differentiation, we examined the effect of TNF-alpha on the expression of these transcription factors in mouse 3T3-L1 preadipocytes. TNF-alpha did not abrogate the induction of C/EBPbeta and C/EBPdelta in response to differentiation stimuli. In fully differentiated adipocytes, TNF-alpha rapidly induced C/EBPbeta and C/EBPdelta, whereas it downregulated the expression of C/EBPalpha and PPARgamma. Our results suggest that TNF-alpha inhibits adipocyte differentiation independently of the downregulation of C/EBPbeta and C/EBPdelta.

  10. Spontaneously beating cardiomyocytes derived from white mature adipocytes

    PubMed Central

    Jumabay, Medet; Zhang, Rui; Yao, Yucheng; Goldhaber, Joshua I.; Boström, Kristina I.

    2010-01-01

    Aims Adipose stromal cells and dissociated brown adipose tissue have been shown to generate cardiomyocyte-like cells. However, it is not clear whether white mature adipocytes have the same potential, even though a close relationship has been found between adipocytes and vascular endothelial cells, another cardiovascular cell type. The objective of this study was to examine if white adipocytes would be able to supply cardiomyocytes. Methods and results We prepared a highly purified population of lipid-filled adipocytes from mice, 6–7 weeks of age. When allowed to lose lipids, the adipocytes assumed a fibroblast-like morphology, so-called dedifferentiated fat (DFAT) cells. Subsequently, 10–15% of the DFAT cells spontaneously differentiated into cardiomyocyte-like cells, in which the cardiomyocyte phenotype was identified by morphological observations, expression of cardiomyocyte-specific markers, and immunocytochemical staining. In addition, electrophysiological studies revealed pacemaker activity in these cells, and functional studies showed that a β-adrenergic agonist stimulated the beating rate, whereas a β-antagonist reduced it. In vitro treatment of newly isolated adipocytes or DFAT cells with inhibitors of bone morphogenetic proteins (BMP) and Wnt signalling promoted the development of the cardiomyocyte phenotype as determined by the number or beating colonies of cardiomyocyte-like cells and expression of troponin I, a cardiomyocyte-specific marker. Inhibition of BMP was most effective in promoting the cardiomyocyte phenotype in adipocytes, whereas Wnt-inhibition was most effective in DFAT cells. Conclusion White mature adipocytes can differentiate into cardiomyocyte-like cells, suggesting a link between adipocyte and cardiomyocyte differentiation. PMID:19643806

  11. Cocoa tea (Camellia ptilophylla) water extract inhibits adipocyte differentiation in mouse 3T3-L1 preadipocytes

    PubMed Central

    Li, Kai Kai; Liu, Chuek Lun; Shiu, Hoi Ting; Wong, Hing Lok; Siu, Wing Sum; Zhang, Cheng; Han, Xiao Qiang; Ye, Chuang Xing; Leung, Ping Chung; Ko, Chun Hay

    2016-01-01

    Cocoa tea (Camellia ptilophylla) is a naturally decaffeinated tea plant. Previously we found that cocoa tea demonstrated a beneficial effect against high-fat diet induced obesity, hepatic steatosis, and hyperlipidemia in mice. The present study aimed to investigate the anti-adipogenic effect of cocoa tea in vitro using preadipocytes 3T3-L1. Adipogenic differentiation was confirmed by Oil Red O stain, qPCR and Western blot. Our results demonstrated that cocoa tea significantly inhibited triglyceride accumulation in mature adipocytes in a dose-dependent manner. Cocoa tea was shown to suppress the expressions of key adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma (PPAR γ) and CCAAT/enhancer binding protein (C/EBP α). The tea extract was subsequently found to reduce the expressions of adipocyte-specific genes such as sterol regulatory element binding transcription factor 1c (SREBP-1c), fatty acid synthase (FAS), Acetyl-CoA carboxylase (ACC), fatty acid translocase (FAT) and stearoylcoenzyme A desaturase-1 (SCD-1). In addition, JNK, ERK and p38 phosphorylation were inhibited during cocoa tea inhibition of 3T3-L1 adipogenic differentiation. Taken together, this is the first study that demonstrates cocoa tea has the capacity to suppress adipogenesis in pre-adipocyte 3T3-L1 similar to traditional green tea PMID:26833256

  12. SIRT2 Suppresses Adipocyte Differentiation by Deacetylating FOXO1 and Enhancing FOXO1's Repressive Interaction with PPARγ

    PubMed Central

    Wang, Fei

    2009-01-01

    Sirtuin family of proteins possesses NAD-dependent deacetylase and ADP ribosyltransferase activities. They are found to respond to nutrient deprivation and profoundly regulate metabolic functions. We have previously reported that caloric restriction increases the expression of one of the seven mammalian sirtuins, SIRT2, in tissues such as white adipose tissue. Because adipose tissue is a key metabolic organ playing a critical role in whole body energy homeostasis, we went on to explore the function of SIRT2 in adipose tissue. We found short-term food deprivation for 24 h, already induces SIRT2 expression in white and brown adipose tissues. Additionally, cold exposure elevates SIRT2 expression in brown adipose tissue but not in white adipose tissue. Intraperitoneal injection of a β-adrenergic agonist (isoproterenol) enhances SIRT2 expression in white adipose tissue. Retroviral expression of SIRT2 in 3T3-L1 adipocytes promotes lipolysis. SIRT2 inhibits 3T3-L1 adipocyte differentiation in low-glucose (1 g/l) or low-insulin (100 nM) condition. Mechanistically, SIRT2 suppresses adipogenesis by deacetylating FOXO1 to promote FOXO1's binding to PPARγ and subsequent repression on PPARγ transcriptional activity. Overall, our results indicate that SIRT2 responds to nutrient deprivation and energy expenditure to maintain energy homeostasis by promoting lipolysis and inhibiting adipocyte differentiation. PMID:19037106

  13. FoxO1 interacts with transcription factor EB and differentially regulates mitochondrial uncoupling proteins via autophagy in adipocytes

    PubMed Central

    Liu, Longhua; Tao, Zhipeng; Zheng, Louise D; Brooke, Joseph P; Smith, Cayleen M; Liu, Dongmin; Long, Yun Chau; Cheng, Zhiyong

    2016-01-01

    Mitochondrial uncoupling proteins (UCPs) are inducible and play an important role in metabolic and redox homeostasis. Recent studies have suggested that FoxO1 controls mitochondrial biogenesis and morphology, but it remains largely unknown how FoxO1 may regulate mitochondrial UCPs. Here we show that FoxO1 interacted with transcription factor EB (Tfeb), a key regulator of autophagosome and lysosome, and mediated the expression of UCP1, UCP2 and UCP3 differentially via autophagy in adipocytes. UCP1 was down-regulated but UCP2 and UCP3 were upregulated during adipocyte differentiation, which was associated with increased Tfeb and autophagy activity. However, inhibition of FoxO1 suppressed Tfeb and autophagy, attenuating UCP2 and UCP3 but increasing UCP1 expression. Pharmacological blockade of autophagy recapitulated the effects of FoxO1 inhibition on UCPs. Chromatin immunoprecipitation assay demonstrated that FoxO1 interacted with Tfeb by directly binding to its promoter, and silencing FoxO1 led to drastic decrease in Tfeb transcript and protein levels. These data provide the first line of evidence that FoxO1 interacts with Tfeb to regulate autophagy and UCP expression in adipocytes. Dysregulation of FoxO1→autophagy→UCP pathway may account for metabolic changes in obesity. PMID:27777789

  14. Cocoa tea (Camellia ptilophylla) water extract inhibits adipocyte differentiation in mouse 3T3-L1 preadipocytes.

    PubMed

    Li, Kai Kai; Liu, Chuek Lun; Shiu, Hoi Ting; Wong, Hing Lok; Siu, Wing Sum; Zhang, Cheng; Han, Xiao Qiang; Ye, Chuang Xing; Leung, Ping Chung; Ko, Chun Hay

    2016-02-01

    Cocoa tea (Camellia ptilophylla) is a naturally decaffeinated tea plant. Previously we found that cocoa tea demonstrated a beneficial effect against high-fat diet induced obesity, hepatic steatosis, and hyperlipidemia in mice. The present study aimed to investigate the anti-adipogenic effect of cocoa tea in vitro using preadipocytes 3T3-L1. Adipogenic differentiation was confirmed by Oil Red O stain, qPCR and Western blot. Our results demonstrated that cocoa tea significantly inhibited triglyceride accumulation in mature adipocytes in a dose-dependent manner. Cocoa tea was shown to suppress the expressions of key adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma (PPAR γ) and CCAAT/enhancer binding protein (C/EBP α). The tea extract was subsequently found to reduce the expressions of adipocyte-specific genes such as sterol regulatory element binding transcription factor 1c (SREBP-1c), fatty acid synthase (FAS), Acetyl-CoA carboxylase (ACC), fatty acid translocase (FAT) and stearoylcoenzyme A desaturase-1 (SCD-1). In addition, JNK, ERK and p38 phosphorylation were inhibited during cocoa tea inhibition of 3T3-L1 adipogenic differentiation. Taken together, this is the first study that demonstrates cocoa tea has the capacity to suppress adipogenesis in pre-adipocyte 3T3-L1 similar to traditional green tea.

  15. Nanoparticle-mediated intracellular lipid accumulation during C2C12 cell differentiation

    SciTech Connect

    Tsukahara, Tamotsu; Haniu, Hisao

    2011-03-25

    Research highlights: {yields} HTT2800 has a significant effect on intracellular lipid accumulation. {yields} HTT2800 reduced muscle-specific genes and led to the emergence of adipocyte-related genes. {yields} HT2800 converts the differentiation pathway of C2C12 myoblasts to that of adipoblast-like cells. -- Abstract: In this report, we sought to elucidate whether multiwall carbon nanotubes are involved in the modulation of the proliferation and differentiation of the skeletal muscle cell line C2C12. Skeletal muscle is a major mass peripheral tissue that accounts for 40% of total body weight and 50% of energy consumption. We focused on the differentiation pathway of myoblasts after exposure to a vapor-grown carbon fiber, HTT2800, which is one of the most highly purified carbon nanotubes. This treatment leads in parallel to the expression of a typical adipose differentiation program. We found that HTT2800 stimulated intracellular lipid accumulation in C2C12 cells. We have also shown by quantified PCR analysis that the expression of adipose-related genes was markedly upregulated during HTT2800 exposure. Taken together, these results suggest that HTT2800 specifically converts the differentiation pathway of C2C12 myoblasts to that of adipoblast-like cells.

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

    SciTech Connect

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

    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

  17. Differential gene expressions in subcutaneous adipose tissue pointed to a delayed adipocytic differentiation in small pig fetuses compared to their heavier siblings.

    PubMed

    Gondret, F; Perruchot, M H; Tacher, S; Bérard, J; Bee, G

    2011-04-01

    Intra-uterine growth retardation in piglets is associated to neonatal losses and a greater susceptibility to fat deposition in the long term. Dietary l-arginine supplementation to gilts during early gestation has been proposed as a way to enhance fetal survival. This study aims to investigate the effects of variation in fetal growth within litters and dietary l-arginine treatment during early gestation in pregnant sows on expression levels of several genes involved in early adipose tissue development and lipid deposition in the fetuses. At day 75 of pregnancy, sows fed a standard gestation diet throughout pregnancy and sows fed 26g L-arginine daily from days 14 to 28 of gestation in supplement to the standard diet were sacrificed. Six pairs of littermates in each dietary group with the smallest or the heaviest fetal weights within each litter were collected (total: 24 fetuses). Expression levels of DLK1/PREF1 and FZD7 were significantly greater in subcutaneous backfat of the smallest fetuses. Conversely, transcriptional adipogenic regulators PPARG, SREBP1, and CEBPA, and genes involved in terminal adipocytic differentiation LPL, ME1, and FABP4 were less expressed in those piglets. Fetal weight has no effect on expression levels of genes involved in cell cycle progression and DNA content in subcutaneous adipose tissue. Maternal dietary L-arginine treatment did not affect subcutaneous adipose tissue features in 75-day old fetuses. The gene expression changes observed in the smallest fetuses are likely associated to a lower body fat content at birth, and could predispose to catch-up fat growth during the postnatal period.

  18. Giant Oyster Mushroom Pleurotus giganteus (Agaricomycetes) Enhances Adipocyte Differentiation and Glucose Uptake via Activation of PPARγ and Glucose Transporters 1 and 4 in 3T3-L1 Cells.

    PubMed

    Paravamsivam, Puvaneswari; Heng, Chua Kek; Malek, Sri Nurestri Abdul; Sabaratnam, Vikineswary; M, Ravishankar Ram; Kuppusamy, Umah Rani

    2016-01-01

    The edible mushroom Pleurotus giganteus was tested for its effect on adipocyte differentiation and glucose uptake activity in 3T3-L1 cells. The basidiocarps of P. giganteus were soaked in methanol to obtain a crude methanol extract and then fractionated to obtain an ethyl acetate extract. In this study, cell proliferation was measured using an MTT assay, lipid accumulation using an Oil Red O assay, and glucose uptake using a fluorescence glucose uptake assay. Gene expression was measured via real-time polymerase chain reaction analysis with TaqMan primer. Ethyl acetate extract significantly enhanced adipogenic differentiation and glucose uptake in 3T3-L1 adipocytes via the expression of sterol regulatory element-binding protein, peroxisome proliferator-activated receptor γ, and phos-phatidylinositol 3-kinase/Akt. Glucose uptake was facilitated by the highly expressed glucose transporters Glut1 and Glut4. Taken together, these results suggest that P. giganteus ethyl acetate extract has an insulin-sensitizing effect on adipocytes and has potential as an adjuvant for the management of type 2 diabetes.

  19. Effects of MicroRNA-23a on Differentiation and Gene Expression Profiles in 3T3-L1 Adipocytes

    PubMed Central

    Huang, Yong; Huang, Jinxiu; Qi, Renli; Wang, Qi; Wu, Yongjiang; Wang, Jing

    2016-01-01

    MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate growth, development, and programmed death of cells. A newly-published study has shown that miRNA-23a could regulate 3T3-L1 adipocyte differentiation. Here, we identified miRNA-23a as a negative regulator of 3T3-L1 adipocyte differentiation again. Over-expression of miRNA-23a inhibited differentiation and decreased lipogenesis as well as down-regulated mRNA and protein expression of both peroxisome proliferator-activated receptor (PPAR) γ and fatty acid binding protein (FABP) 4, whereas knock down of miRNA-23a showed the opposite effects on differentiation as well as increasing the number of apoptotic cells. Additionally, digital gene expression profiling sequencing (DGE-Seq) was used to assay changes in gene expression profiles following alterations in the level of miR-23a. In total, over-expression or knock down of miRNA-23a significantly changed the expression of 313 and 425 genes, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that these genes were mainly involved in the stress response, immune system, metabolism, cell cycle, among other pathways. Additionally, the signal transducer and activator of transcription 1 (Stat1) was shown to be a target of miRNA-23a by computational and dual-luciferase reporter assays that indicated Janus Kinase (Jak)-Stat signal pathway was implicated in regulating adipogenesis mediated by miRNA-23a in adipocytes. PMID:27783036

  20. Clonal mature adipocyte production of proliferative-competent daughter cells requires lipid export prior to cell division

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous in vitro observations have been published to show that mature adipocytes may resume proliferation and begin to populate the adipofibroblast fraction or form other cell types. In the present study, we evaluated clonal cultures of mature pig-derived adipocytes as they began to reestablish the...

  1. Uncoupling of 3T3-L1 gene expression from lipid accumulation during adipogenesis.

    PubMed

    Temple, Karla A; Basko, Xheni; Allison, Margaret B; Brady, Matthew J

    2007-02-06

    Adipocyte differentiation comprises altered gene expression and increased triglyceride storage. To investigate the interdependency of these two events, 3T3-L1 cells were differentiated in the presence of glucose or pyruvate. All adipocytic proteins examined were similarly increased between the two conditions. In contrast, 3T3-L1 adipocytes differentiated with glucose exhibited significant lipid accumulation, which was largely suppressed in the presence of pyruvate. Subsequent addition of glucose to the latter cells restored lipid accumulation and acute rates of insulin-stimulated lipogenesis. These data indicate that extracellular energy is required for induction of adipocytic proteins, while only glucose sustained the parallel increase in triglyceride storage.

  2. Identification of suitable reference genes for quantitative RT-PCR during 3T3-L1 adipocyte differentiation.

    PubMed

    Zhang, Juan; Tang, Hongju; Zhang, Yuqing; Deng, Ruyuan; Shao, Li; Liu, Yun; Li, Fengying; Wang, Xiao; Zhou, Libin

    2014-05-01

    Quantitative reverse transcription PCR (qRT-PCR) is becoming increasingly important in the effort to gain insight into the molecular mechanisms underlying adipogenesis. However, the expression profile of a target gene may be misinterpreted due to the unstable expression of the reference genes under different experimental conditions. Therefore, in this study, we investigated the expression stability of 10 commonly used reference genes during 3T3-L1 adipocyte differentiation. The mRNA expression levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and transferrin receptor (TFRC) significantly increased during the course of 3T3-L1 adipocyte differentiation, which was decreased by berberine, an inhibitor of adipogenesis. Three popular algorithms, GeNorm, NormFinder and BestKeeper, identified 18 ribosomal RNA and hydroxymethylbilane synthase (HMBS) as the most stable reference genes, while GAPDH and TFRC were the least stable ones. Peptidylprolyl isomerase A [PIPA (cyclophilin A)], ribosomal protein, large, P0 (36-B4), beta-2-microglobulin (B2M), α1-tubulin, hypoxanthine-guanine phosphoribosyltransferase (HPRT) and β-actin showed relatively stable expression levels. The choice of reference genes with various expression stabilities exerted a profound influence on the expression profiles of 2 target genes, peroxisome proliferator-activated receptor (PPAR)γ2 and C/EBPα. In addition, western blot analysis revealed that the increased protein expression of GAPDH was markedly inhibited by berberine during adipocyte differentiation. This study highlights the importance of selecting suitable reference genes for qRT-PCR studies of gene expression during the process of adipogenesis.

  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.

    PubMed

    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

    PubMed Central

    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. Brain Natriuretic Peptide Stimulates Lipid Metabolism through Its Receptor NPR1 and the Glycerolipid Metabolism Pathway in Chicken Adipocytes.

    PubMed

    Huang, H Y; Zhao, G P; Liu, R R; Li, Q H; Zheng, M Q; Li, S F; Liang, Z; Zhao, Z H; Wen, J

    2015-11-03

    Brain natriuretic peptide (BNP) is related to lipid metabolism in mammals, but its effect and the molecular mechanisms underlying it in chickens are incompletely understood. We found that the level of natriuretic peptide precursor B (NPPB, which encodes BNP) mRNA expression in high-abdominal-fat chicken groups was significantly higher than that of low-abdominal-fat groups. Partial correlations indicated that changes in the weight of abdominal fat were positively correlated with NPPB mRNA expression level. In vitro, compared with the control group, preadipocytes with NPPB interference showed reduced levels of proliferation, differentiation, and glycerin in media. Treatments of cells with BNP led to enhanced proliferation and differentiation of cells and glycerin concentration, and mRNA expression of its receptor natriuretic peptide receptor 1 (NPR1) was upregulated significantly. In cells exposed to BNP, 482 differentially expressed genes were identified compared with controls without BNP. Four genes known to be related to lipid metabolism (diacylglycerol kinase; lipase, endothelial; 1-acylglycerol-3-phosphate O-acyltransferase 1; and 1-acylglycerol-3-phosphate O-acyltransferase 2) were enriched in the glycerolipid metabolism pathway and expressed differentially. In conclusion, BNP stimulates the proliferation, differentiation, and lipolysis of preadipocytes through upregulation of the levels of expression of its receptor NPR1 and key genes enriched in the glycerolipid metabolic pathway.

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

    SciTech Connect

    Xu, Y.; Mirmalek-Sani, S.-H.; Yang, X.; Zhang, J.; Oreffo, R.O.C. . E-mail: roco@soton.ac.uk

    2006-06-10

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

  7. The E3 ubiquitin ligase TRIM23 regulates adipocyte differentiation via stabilization of the adipogenic activator PPARγ.

    PubMed

    Watanabe, Masashi; Takahashi, Hidehisa; Saeki, Yasushi; Ozaki, Takashi; Itoh, Shihori; Suzuki, Masanobu; Mizushima, Wataru; Tanaka, Keiji; Hatakeyama, Shigetsugu

    2015-04-23

    Adipocyte differentiation is a strictly controlled process regulated by a series of transcriptional activators. Adipogenic signals activate early adipogenic activators and facilitate the transient formation of early enhanceosomes at target genes. These enhancer regions are subsequently inherited by late enhanceosomes. PPARγ is one of the late adipogenic activators and is known as a master regulator of adipogenesis. However, the factors that regulate PPARγ expression remain to be elucidated. Here, we show that a novel ubiquitin E3 ligase, tripartite motif protein 23 (TRIM23), stabilizes PPARγ protein and mediates atypical polyubiquitin conjugation. TRIM23 knockdown caused a marked decrease in PPARγ protein abundance during preadipocyte differentiation, resulting in a severe defect in late adipogenic differentiation, whereas it did not affect the formation of early enhanceosomes. Our results suggest that TRIM23 plays a critical role in the switching from early to late adipogenic enhanceosomes by stabilizing PPARγ protein possibly via atypical polyubiquitin conjugation.

  8. The effects of retinoic acid on reversing the adipocyte differentiation into an osteoblastic tendency in ST2 cells, a murine bone marrow-derived stromal cell line.

    PubMed

    Ding, J; Woo, J T; Nagai, K

    2001-07-01

    Although the mouse bone marrow stromal cell line ST2 has been known to be differentiated into osteoblasts, the differentiation characteristics of the cell into adipocyte and the concerned relationship between its adipogenesis and osteogenesis remains unknown. The adipogenic induction medium which is made up of insulin, dexamethasone (DEX) and 3-isobutyl-1-methylxanthine(IBMX), stimulated the expression of n early adipogenic marker PPAR gamma and a late marker GPDH in ST2 cells. The triglyceride accumulation and lipid stain level generated by the induction medium in ST2 cells was inhibited by RA with IC(50) at about 1 nM. The induction medium up-regulated expression of PPARgamma and GPDH was also inhibited by RA whereas RA (30 nM) exterted no effect on the cell growth. Interestingly, treatment of the cells with induction medium in the presense of RA caused a 3- or 10-fold higher in ALP activity respectively as compared to those treated with RA or the induction medium alone. RT-PCR analysis showed that such a synergistic effect of RA and the induction medium paralleled the process of inhibition on adipogenesis. Additional experiments showed that IBMX played a key role in increasing the effect of RA and ALP activity. Our results suggested that the relationship between adipogenesis and osteogenesis in ST2 cells was reciprocally interrelated and the process of adipogenesis could be potentially reversed into an osteoblastogenic tendency. This is the first report demonstrating that RA transforms adipogenic potential into an osteoblastic tendency.

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

    PubMed

    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.

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

    PubMed

    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.

  11. Metabolic programming of a beige adipocyte phenotype by genistein

    PubMed Central

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

    2016-01-01

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

  12. Differential association of S100A9, an inflammatory marker, and p53, a cell cycle marker, expression with epicardial adipocyte size in patients with cardiovascular disease.

    PubMed

    Agra, Rosa María; Fernández-Trasancos, Ángel; Sierra, Juan; González-Juanatey, José Ramón; Eiras, Sonia

    2014-10-01

    S100A9 (calgranulin B) has inflammatory and oxidative stress properties and was found to be associated with atherosclerosis and obesity. One of the proteins that can regulate S100A9 transcription is p53, which is involved in cell cycle, apoptosis and adipogenesis. Thus, it triggers adipocyte enlargement and finally obesity. Because epicardial adipose tissue (EAT) volume and thickness is related to coronary artery disease (CAD), we studied the gene expression of this pathway in patients with cardiovascular disease and its association with obesity. Adipocytes and stromal cells from EAT and subcutaneous adipose tissue (SAT) from 48 patients who underwent coronary artery bypass graft and/or valve replacement were obtained after collagenase digestion and differential centrifugation. The expression levels of the involved genes on adipogenesis and cell cycle like fatty acid-binding protein (FABP) 4, retinol-binding protein (RBP)4, p53 and S100A9 were determined by real-time polymerase chain reaction (PCR). Adipocyte diameter was measured by optical microscopy. We found that epicardial adipocytes expressed significantly lower levels of adipogenic genes (FABP4 and RBP4) and cell cycle-related genes (S100A9 and p53) than subcutaneous adipocytes. However, in obese patients, upregulation of adipogenic and cell cycle-related genes in subcutaneous and epicardial adipocytes, respectively, was observed. The enlargement of adipocyte size was related to FABP4, S100A9 and p53 expression levels in stromal cells. But only the p53 association was maintained in epicardial stromal cells from obese patients (p=0.003). The expression of p53, but not S100A9, in epicardial stromal cells is related to adipocyte enlargement in obese patients with cardiovascular disease. These findings suggest new mechanisms for understanding the relationship between epicardial fat thickness, obesity and cardiovascular disease.

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

    PubMed

    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 (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.

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

    PubMed Central

    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 1nM 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. PMID:26942597

  15. Control of Differentiation of a Mammary Cell Line by Lipids

    NASA Astrophysics Data System (ADS)

    Dulbecco, Renato; Bologna, Mauro; Unger, Michael

    1980-03-01

    A rat mammary cell line (LA7) undergoes spontaneous differentiation into domes due to production of specific inducers by the cells. Some of these inducers may be lipids, and we show that lipids regulate this differentiation as both inducers and inhibitors. One inhibitor is the tumor promoter tetradecanoyl-13 phorbol 12-acetate. The inducers are saturated fatty acids of two groups: butyric acid and acids with chain lengths from C13 to C16, especially myristic acid (C14). Other inducers are myristoyl and palmitoyl lysolecithins, myristic acid methyl ester, and two cationic detergents with a tetradecenyl chain. We propose that the lipids with a C14-C16 alkyl chain affect differentiation by recognizing specific receptors through their alkyl chains and that the effects obtained depend on the head groups. These lipids may be physiological regulators in the mammary gland.

  16. Fucoidan from the sporophyll of Undaria pinnatifida suppresses adipocyte differentiation by inhibition of inflammation-related cytokines in 3T3-L1 cells.

    PubMed

    Kim, Kui-Jin; Lee, Boo-Yong

    2012-06-01

    Obesity is a metabolic disorder, associated with cardiovascular disease and type 2 diabetes mellitus. Recent studies suggest that seaweed extracts are a significant source of bioactive compounds that are similar to dietary phytochemicals. Fucoidan, which is extracted from brown seaweeds, has a number of physiological functions. However, it is still unclear whether fucoidan would be beneficial in adipogenesis. In this study, we hypothesized that fucoidan extracted from the sporophyll of U pinnatifida exerts anti-obesity effects via inhibition of inflammatory-related cytokines. Thus, to test our hypothesis, we determined the obesity-specific therapeutic action of fucoidan in 3T3-L1 adipocytes. Herein, we showed that proliferator-activated receptor γ, CCAAR/enhancer-binding protein α, and adipocyte protein 2 were significantly suppressed in the presence of fucoidan, which decreased expression of the inflammation-related genes during adipogenesis in 3T3-L1 adipocytes. Moreover, fucoidan also reduced the accumulation of lipids and reactive oxygen species production in adipocytes. In conclusion, these results demonstrate that fucoidan from the sporophyll of U pinnatifida suppresses adipogenesis through the inhibition of major markers and inflammation-related cytokines in adipocytes. Hence, these findings indicate that fucoidan may afford some potential to control or reduce obesity.

  17. Differential modulation of ROS signals and other mitochondrial parameters by the antioxidants MitoQ, resveratrol and curcumin in human adipocytes.

    PubMed

    Hirzel, Estelle; Lindinger, Peter W; Maseneni, Swarna; Giese, Maria; Rhein, Véronique Virginie; Eckert, Anne; Hoch, Matthias; Krähenbühl, Stephan; Eberle, Alex N

    2013-10-01

    Mitochondrial reactive oxygen species (ROS) have been demonstrated to play an important role as signaling and regulating molecules in human adipocytes. In order to evaluate the differential modulating roles of antioxidants, we treated human adipocytes differentiated from human bone marrow-derived mesenchymal stem cells with MitoQ, resveratrol and curcumin. The effects on ROS, viability, mitochondrial respiration and intracellular ATP levels were examined. MitoQ lowered both oxidizing and reducing ROS. Resveratrol decreased reducing and curcumin oxidizing radicals only. All three substances slightly decreased state III respiration immediately after addition. After 24 h of treatment, MitoQ inhibited both basal and uncoupled oxygen consumption, whereas curcumin and resveratrol had no effect. Intracellular ATP levels were not altered. This demonstrates that MitoQ, resveratrol and curcumin exert potent modulating effects on ROS signaling in human adipocyte with marginal effects on metabolic parameters.

  18. Original Research: Hydroxytyrosol, an ingredient of olive oil, reduces triglyceride accumulation and promotes lipolysis in human primary visceral adipocytes during differentiation

    PubMed Central

    Stefanon, Bruno

    2016-01-01

    Hydroxytyrosol has various pharmacological properties, including anti-oxidative stress and anti-inflammatory activities, preventing hyperglycemia, insulin resistance, and the metabolic syndrome. The present study is focused on the anti-adipogenic and lipolytic activity of hydroxytyrosol on primary human visceral adipocytes. Pre-adipocytes were analyzed after 10 (P10) and 20 (P20) days of treatment during differentiation and after 7 (A7) days of treatment when they reached mature shape. The treatment with hydroxytyrosol extract significantly (P < 0.001) increased apoptosis in P10 and P20 cells in comparison to control and A7 cells; significantly (P < 0.001) reduced triglyceride accumulation in P20 cells compared to P10 and control cells; and significantly (P < 0.001) increased lipolysis in P20 cells in comparison to control cells and A7 mature adipocytes. Hydroxytyrosol-treated P20 cells significantly (P < 0.05) increased expression of genes involved in inhibition of adipogenesis, such as GATA2, GATA3, WNT3A, SFRP5, HES1, and SIRT1. In contrast, genes involved in promoting adipogenesis such as LEP, FGF1, CCND1, and SREBF1 were significantly down-regulated by hydroxytyrosol treatment. These data suggest that hydroxytyrosol promotes lipolysis and apoptotic activity in primary human visceral pre-adipocytes during differentiation and does not affect already mature adipocytes. PMID:27287014

  19. Paprika Pigments Attenuate Obesity-Induced Inflammation in 3T3-L1 Adipocytes

    PubMed Central

    Maeda, Hayato; Saito, Shuuichi; Nakamura, Nozomi; Maoka, Takashi

    2013-01-01

    Obesity is related to various diseases, such as diabetes, hyperlipidemia, and hypertension. Adipocytokine, which is released from adipocyte cells, affects insulin resistance and blood lipid level disorders. Further, adipocytokine is related to chronic inflammation in obesity condition adipocyte cells. Paprika pigments (PPs) contain large amounts of capsanthin and capsorubin. These carotenoids affect the liver and improve lipid disorders of the blood. However, how these carotenoids affect adipocyte cells remains unknown. Present study examined the effects of PP on adipocytokine secretion, which is related to improvement of metabolic syndrome. In addition, suppressive effects of PP on chronic inflammation in adipocyte cells were analyzed using 3T3-L1 adipocyte cells and macrophage cell coculture experiments. PP promoted 3T3-L1 adipocyte cells differentiation upregulated adiponectin mRNA expression and secretion. Further, coculture of adipocyte and macrophage cells treated with PP showed suppressed interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1), and resistin mRNA expression, similarly to treatment with troglitazone, which is a PPARγ ligand medicine. Conclusion. These results suggest that PP ameliorates chronic inflammation in adipocytes caused by obesity. PP adjusts adipocytokine secretion and might, therefore, affect antimetabolic syndrome diseases. PMID:24049664

  20. Fisetin Suppresses Lipid Accumulation in Mouse Adipocytic 3T3-L1 Cells by Repressing GLUT4-Mediated Glucose Uptake through Inhibition of mTOR-C/EBPα Signaling.

    PubMed

    Watanabe, Marina; Hisatake, Mitsuhiro; Fujimori, Ko

    2015-05-27

    3,7,3',4'-Tetrahydroxyflavone (fisetin) is a flavonoid found in vegetables and fruits having broad biological activities. Here the effects of fisetin on adipogenesis and its regulatory mechanism in mouse adipocytic 3T3-L1 cells are studied. Fisetin inhibited the accumulation of intracellular lipids and lowered the expression of adipogenic genes such as peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein (C/EBP) α and fatty acid-binding protein 4 (aP2) during adipogenesis. Moreover, the mRNA levels of genes such as acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase involved in the fatty acid biosynthesis (lipogenesis) were reduced by the treatment with fisetin. The expression level of the glucose transporter 4 (GLUT4) gene was also decreased by fisetin, resulting in down-regulation of glucose uptake. Furthermore, fisetin inhibited the phosphorylation of the mammalian target of rapamycin (mTOR) and that of p70 ribosomal S6 kinase, a target of the mTOR complex, the inhibition of which was followed by a decreased mRNA level of the C/EBPα gene. The results obtained from a chromatin immunoprecipitation assay demonstrated that the ability of C/EBPα to bind to the GLUT4 gene promoter was reduced by the treatment with fisetin, which agreed well with those obtained when 3T3-L1 cells were allowed to differentiate into adipocytes in medium in the presence of rapamycin, an inhibitor for mTOR. These results indicate that fisetin suppressed the accumulation of intracellular lipids by inhibiting GLUT4-mediated glucose uptake through inhibition of the mTOR-C/EBPα signaling in 3T3-L1 cells.

  1. Effects of perfluorinated chemicals on adipocyte development ...

    EPA Pesticide Factsheets

    Obesity is a growing concern in the US population. Current interest is high in the role played by environmental factors called obesogens that may contribute to obesity through developmental exposure. One class of potential obesogens is the family of perfluorinated chemicals used as surfactants in a variety of industrial applications. Given the importance of understanding the role these compounds play in lipid homeostasis we used pre-adipocyte 3T3-L1 mouse fibroblast cells (Zen-Bio, RTP NC) to study their effects on adipogenesis and lipid accumulation. These cells differentiate into adipocytes accumulating large lipid droplets. Cultures were treated with perfluorooctanoic acid (PFOA) (1-200uM), perfluorononanoic acid (PFNA) (5-lOOuM), perfluorooctane sulfonate (PFOS) (5O-300uM), and perfluorohexane sulfonate (PFHxS) (40- 250uM). Cell size number, and lipid content were assessed using morphomeiric analysis. All four compounds decreased cell size compared to control, and PFNA was most potent, in terms of lowest observed effect concentration (LOEC), whereas PFOA was least potent. Cell number increased for all perfluorinated chemicals tested, most potently for PFNA and least for PFOS. Interestingly, average lipid area per cell for all four chemicals decreased compared to control, but PFOS and PFHxS had increased total lipid area. Additionally, significant increases in total triglyceride were noted for all compounds compared to controls. PFOA and PFNA increased trigly

  2. Human translocation liposarcoma-CCAAT/enhancer binding protein (C/EBP) homologous protein (TLS-CHOP) oncoprotein prevents adipocyte differentiation by directly interfering with C/EBPbeta function.

    PubMed

    Adelmant, G; Gilbert, J D; Freytag, S O

    1998-06-19

    Human translocation liposarcoma (TLS)-CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP) is a fusion oncoprotein found specifically in a malignant tumor of adipose tissue and results from a t(12;16) translocation that fuses the amino-terminal part of TLS to the entire coding region of CHOP. Being that CHOP is a member of the C/EBP transcription factor family, proteins that comprise part of the adipocyte differentiation machinery, we examined whether TLS-CHOP blocked adipocyte differentiation by directly interfering with C/EBP function. Using a single-step retroviral infection protocol, either wild-type or mutant TLS-CHOP were co-expressed along with C/EBPbeta in naïve NIH3T3 cells, and their ability to inhibit C/EBPbeta-driven adipogenesis was determined. TLS-CHOP was extremely effective at blocking adipocyte differentiation when expressed at a level comparable to that observed in human myxoid liposarcoma. This effect of TLS-CHOP required a functional leucine zipper domain and correlated with its ability to heterodimerize with C/EBPbeta and inhibit C/EBPbeta DNA binding and transactivation activity in situ. In contrast, the TLS-CHOP basic region was dispensable, making it unlikely that the inhibitory effect of TLS-CHOP is attributable to unscheduled gene expression resulting from TLS-CHOP's putative transactivation activity. Another adipogenic transcription factor, PPARgamma2, was able to rescue TLS-CHOP-inhibited cells, indicating that TLS-CHOP interferes primarily with C/EBPbeta-driven adipogenesis and not with other requisite events of the adipocyte differentiation program. Together, the results demonstrate that TLS-CHOP blocks adipocyte differentiation by directly preventing C/EBPbeta from binding to and transactivating its target genes. Moreover, they provide strong support for the thesis that a blockade to normal differentiation is an important aspect of the cancer process.

  3. Nuclear factor I-C reciprocally regulates adipocyte and osteoblast differentiation via control of canonical Wnt signaling.

    PubMed

    Zhou, Jie; Wang, Shan; Qi, Qi; Yang, Xiaoyue; Zhu, Endong; Yuan, Hairui; Li, Xuemei; Liu, Ying; Li, Xiaoxia; Wang, Baoli

    2017-01-25

    Nuclear factor I-C (NFIC) has recently been identified as an important player in osteogenesis and bone homeostasis in vivo However, the molecular mechanisms involved have yet to be defined. In the current study, Nfic expression was altered in primary marrow stromal cells and established progenitor lines after adipogenic and osteogenic treatment. Overexpression of Nfic in stromal cells ST2, mesenchymal cells C3H10T1/2, and primary marrow stromal cells inhibited adipogenic differentiation, whereas it promoted osteogenic differentiation. Conversely, silencing of endogenous Nfic in the cell lines enhanced adipogenic differentiation, whereas it blocked osteogenic differentiation. Mechanism investigations revealed that Nfic overexpression promoted nuclear translocation of β-catenin and increased nuclear protein levels of β-catenin and transcription factor 7-like 2 (TCF7L2). Promoter studies and the chromatin immunoprecipitation (ChIP) assay revealed that NFIC directly binds to the promoter of low-density lipoprotein receptor-related protein 5 (Lrp5) and thereafter transactivates the promoter. Finally, inactivation of canonical Wnt signaling in ST2 attenuated the inhibition of adipogenic differentiation and stimulation of osteogenic differentiation by NFIC. Our study suggests that NFIC balances adipogenic and osteogenic differentiation from progenitor cells through controlling canonical Wnt signaling and highlights the potential of NFIC as a target for new therapies to control metabolic disorders like osteoporosis and obesity.-Zhou, J., Wang, S., Qi, Q., Yang, X., Zhu, E., Yuan, H., Li, X., Liu, Y., Li, X., Wang, B. Nuclear factor I-C reciprocally regulates adipocyte and osteoblast differentiation via control of canonical Wnt signaling.

  4. Programming human pluripotent stem cells into white and brown adipocytes

    PubMed Central

    Ahfeldt, Tim; Schinzel, Robert T.; Lee, Youn-Kyoung; Hendrickson, David; Kaplan, Adam; Lum, David H.; Camahort, Raymond; Xia, Fang; Shay, Jennifer; Rhee, Eugene P.; Clish, Clary B.; Deo, Rahul C.; Shen, Tony; Lau, Frank H.; Cowley, Alicia; Mowrer, Greg; Al-Siddiqi, Heba; Nahrendorf, Matthias; Musunuru, Kiran; Gerszten, Robert E.; Rinn, John L.; Cowan, Chad A.

    2012-01-01

    The utility of human pluripotent stem cells is dependent on efficient differentiation protocols that convert these cells into relevant adult cell types. Here we report the robust and efficient differentiation of human pluripotent stem cells into white or brown adipocytes. We found that inducible expression of PPARG2 alone or combined with CEBPB and/or PRDM16 in mesenchymal progenitor cells derived from pluripotent stem cells programmed their development towards a white or brown adipocyte cell fate with efficiencies of 85%–90%. These adipocytes retained their identity independent of transgene expression, could be maintained in culture for several weeks, expressed mature markers and had mature functional properties such as lipid catabolism and insulin-responsiveness. When transplanted into mice, the programmed cells gave rise to ectopic fat pads with the morphological and functional characteristics of white or brown adipose tissue. These results indicate that the cells could be used to faithfully model human disease. PMID:22246346

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

    PubMed Central

    Hafizi Abu Bakar, Mohamad; Sarmidi, Mohamad Roji; Kai, Cheng Kian; Huri, Hasniza Zaman; Yaakob, Harisun

    2014-01-01

    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. PMID:25474091

  6. Fatty Acids from Membrane Lipids Become Incorporated into Lipid Bodies during Myxococcus xanthus Differentiation

    PubMed Central

    Bhat, Swapna; Boynton, Tye O.; Pham, Dan; Shimkets, Lawrence J.

    2014-01-01

    Myxococcus xanthus responds to amino acid limitation by producing fruiting bodies containing dormant spores. During development, cells produce triacylglycerides in lipid bodies that become consumed during spore maturation. As the cells are starved to induce development, the production of triglycerides represents a counterintuitive metabolic switch. In this paper, lipid bodies were quantified in wild-type strain DK1622 and 33 developmental mutants at the cellular level by measuring the cross sectional area of the cell stained with the lipophilic dye Nile red. We provide five lines of evidence that triacylglycerides are derived from membrane phospholipids as cells shorten in length and then differentiate into myxospores. First, in wild type cells, lipid bodies appear early in development and their size increases concurrent with an 87% decline in membrane surface area. Second, developmental mutants blocked at different stages of shortening and differentiation accumulated lipid bodies proportionate with their cell length with a Pearson's correlation coefficient of 0.76. Third, peripheral rods, developing cells that do not produce lipid bodies, fail to shorten. Fourth, genes for fatty acid synthesis are down-regulated while genes for fatty acid degradation are up regulated. Finally, direct movement of fatty acids from membrane lipids in growing cells to lipid bodies in developing cells was observed by pulse labeling cells with palmitate. Recycling of lipids released by Programmed Cell Death appears not to be necessary for lipid body production as a fadL mutant was defective in fatty acid uptake but proficient in lipid body production. The lipid body regulon involves many developmental genes that are not specifically involved in fatty acid synthesis or degradation. MazF RNA interferase and its target, enhancer-binding protein Nla6, appear to negatively regulate cell shortening and TAG accumulation whereas most cell-cell signals activate these processes. PMID:24906161

  7. Mature adipocyte-derived dedifferentiated fat cells can trans-differentiate into osteoblasts in vitro and in vivo only by all-trans retinoic acid.

    PubMed

    Oki, Yoshinao; Watanabe, Saiko; Endo, Tuyoshi; Kano, Koichiro

    2008-01-01

    We investigated whether de-differentiated fat (DFAT) cells, a mature adipocyte-derived preadipocyte cell line, can be induced to trans-differentiate into osteoblasts in vitro and in vivo. All-trans retinoic acid (RA) induced expression of osteoblast-specific mRNAs encoding Cbfa1/Runx2, osterix, alkaline phosphatase, osteopontin, parathyroid hormone receptor, and osteocalcin in the DFAT cells, but did not induce the expression of adipocyte-specific mRNAs encoding PPARgamma2, C/EBPalpha, and GLUT4. Moreover, alkaline phosphatase activity was expressed in DFAT cells and the cells underwent mineralization of the bone matrix in vitro. Furthermore, when DFAT cells were transplanted subcutaneously into C57BL/6N mice in diffusion chambers, these cells formed ectopic osteoid tissue without any host cell-invasion of the chambers. These results indicate that DFAT cells derived from mature adipocytes can be converted into fully differentiated osteoblasts in vitro and in vivo using RA. DFAT cells provide a unique model for studying the lineage commitment of the adipocytes and osteoblasts derived from mesenchymal stem cells. Identification of the pathways that regulate these processes could lead to the development of new therapeutic strategies for control of unwarranted growth of bone and adipose tissue.

  8. Inhibitor of DNA Binding 4 (ID4) Regulation of Adipocyte Differentiation and Adipose Tissue Formation in Mice*

    PubMed Central

    Murad, Joana M.; Place, Chelsea S.; Ran, Cong; Hekmatyar, Shahryar K. N.; Watson, Nathan P.; Kauppinen, Risto A.; Israel, Mark A.

    2010-01-01

    Inhibitor of DNA binding 4 (ID4) is a helix-loop-helix protein that heterodimerizes with basic helix-loop-helix transcription factors inhibiting their function. ID4 expression is important for adipogenic differentiation of the 3T3-L1 cell line, and inhibition of ID4 is associated with a concomitant decrease in CCAAT/enhancer-binding protein α and peroxisome proliferator-activated receptor γ mRNA and protein expression. Mice with a homozygous deletion of Id4 (Id4−/−) have reduced body fat and gain much less weight compared with wild-type littermates when placed on diets with high fat content. Mouse embryonic fibroblasts (MEFs) isolated from Id4−/− mice have reduced adipogenic potential when compared with wild-type MEFs. In agreement with changes in morphological differentiation, the levels of CCAAT/enhancer-binding protein α and peroxisome proliferator-activated receptor γ were also reduced in MEFs from Id4−/− mice. Our results demonstrate the importance of ID4 in adipocyte differentiation and the implications of this regulation for adipose tissue formation. PMID:20460371

  9. High-density lipoprotein and apolipoprotein A-I inhibit palmitate-induced translocation of toll-like receptor 4 into lipid rafts and inflammatory cytokines in 3T3-L1 adipocytes.

    PubMed

    Yamada, Hodaka; Umemoto, Tomio; Kawano, Mikihiko; Kawakami, Masanobu; Kakei, Masafumi; Momomura, Shin-Ichi; Ishikawa, San-E; Hara, Kazuo

    2017-03-04

    Saturated fatty acids (SFAs) activate toll-like receptor 4 (TLR4) signal transduction in macrophages and are involved in the chronic inflammation accompanying obesity. High-density lipoprotein (HDL) and apolipoprotein A-I (apoA-I) produce anti-inflammatory effects via reverse cholesterol transport. However, the underlying mechanisms by which HDL and apoA-I inhibit inflammatory responses in adipocytes remain to be determined. Here we examined whether palmitate increases the translocation of TLR4 into lipid rafts and whether HDL and apoA-I inhibit inflammation in adipocytes. Palmitate exposure (250 μM, 24 h) increased interleukin-6 and tumor necrosis factor-α gene expressions and translocation of TLR4 into lipid rafts in 3T3-L1 adipocytes. Pretreatment with HDL and apoA-I (50 μg/mL, 6 h) suppressed palmitate-induced inflammatory cytokine expression and TLR4 translocation into lipid rafts. Moreover, HDL and apoA-I inhibited palmitate-induced phosphorylation of nuclear factor-kappa B. HDL showed an anti-inflammatory effect via ATP-binding cassette transporter G1 and scavenger receptor class B, member 1, whereas apoA-I showed an effect via ATP-binding cassette transporter A1. These results demonstrated that HDL and apoA-I reduced palmitate-potentiated TLR4 trafficking into lipid rafts and its related inflammation in adipocytes via these specific transporters.

  10. MDM2 facilitates adipocyte differentiation through CRTC-mediated activation of STAT3

    PubMed Central

    Hallenborg, P; Siersbæk, M; Barrio-Hernandez, I; Nielsen, R; Kristiansen, K; Mandrup, S; Grøntved, L; Blagoev, B

    2016-01-01

    The ubiquitin ligase MDM2 is best known for balancing the activity of the tumor suppressor p53. We have previously shown that MDM2 is vital for adipocyte conversion through controlling Cebpd expression in a p53-independent manner. Here, we show that the proadipogenic effect of MDM2 relies on activation of the STAT family of transcription factors. Their activation was required for the cAMP-mediated induction of target genes. Interestingly, rather than influencing all cAMP-stimulated genes, inhibition of the kinases directly responsible for STAT activation, namely JAKs, or ablation of MDM2, each resulted in abolished induction of a subset of cAMP-stimulated genes, with Cebpd being among the most affected. Moreover, STATs were able to interact with the transcriptional cofactors CRTC2 and CRTC3, hitherto only reported to associate with the cAMP-responsive transcription factor CREB. Last but not least, the binding of CRTC2 to a transcriptional enhancer that interacts with the Cebpd promoter was dramatically decreased upon JAK inhibition. Our data reveal the existence of an unusual functional interplay between STATs and CREB at the onset of adipogenesis through shared CRTC cofactors. PMID:27362806

  11. Cholesterol depletion blocks redistribution of lipid raft components and insulin-mimetic signaling by glimepiride and phosphoinositolglycans in rat adipocytes.

    PubMed Central

    Müller, Gunter; Hanekop, Nils; Wied, Susanne; Frick, Wendelin

    2002-01-01

    Glycosylphosphatidylinositol-anchored plasma membrane (GPI) proteins, such as Gce1, the dually acylated nonreceptor tyrosine kinases (NRTKs), such as pp59(Lyn), and the membrane protein, caveolin, together with cholesterol are typical components of detergent/carbonate-insoluble glycolipid-enriched raft domains (DIGs) in the plasma membrane of most eucaryotes. Previous studies demonstrated the dissociation from caveolin and concomitant redistribution from DIGs of Gce1 and pp59(Lyn) in rat adipocytes in response to four different insulin-mimetic stimuli, glimepiride, phosphoinositolglycans, caveolin-binding domain peptide, and trypsin/NaCl-treatment. We now characterized the structural basis for this dynamic of DIG components. MATERIALS AND METHODS: Carbonate extracts from purified plasma membranes of basal and stimulated adipocytes were analyzed by high-resolution sucrose gradient centrifugation. RESULTS: This process revealed the existence of two distinct species of detergent/carbonate-insoluble complexes floating at higher buoyant density and harboring lower amounts of cholesterol, caveolin, GPI proteins, and NRTKs (lcDIGs) compared to typical DIGs of high cholesterol content (hcDIGs). The four insulin-mimetic stimuli decreased by 40-70% and increased by 2.5- to 5-fold the amounts of GPI proteins and NRTKs at hcDIGs and lcDIGs, respectively. Cholesterol depletion of adipocytes per se by incubation with methyl-beta-cyclodextrin or cholesterol oxidase also caused translocation of GPI proteins and NRTKs from hcDIGs to lcDIGs and their release from caveolin in reversible fashion without concomitant induction of insulin-mimetic signaling. Cholesterol depletion, however, reduced by 50-60% the stimulus-induced translocation as well as dissociation from hcDIGs-associated caveolin of GPI proteins and NRTKs, activation of NRTKs as well as insulin-mimetic signaling and metabolic action. In contrast, insulin-mimetic signaling induced by vanadium compounds was not

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

    PubMed

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

    2015-12-18

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

  13. Macrophage and adipocyte IGF1 maintain adipose tissue homeostasis during metabolic stresses

    PubMed Central

    Chang, Hye Rim; Kim, Hae Jin; Xu, Xiaoyuan; Ferrante, Anthony W.

    2015-01-01

    Objective IGF1 regulates differentiation and growth of tissues and reduces stress and injury. IGF1 also in a tissue specific manner modulates the differentiation and lipid storage capacity of adipocytes in vitro, but its roles in adipose tissue development and response to stress are not known. Methods To study IGF1 in vivo, we identified the cellular sources of adipose tissue Igf1 expression and generated mice with targeted deletion in adipocytes and macrophages. We studied the effects of adipocyte and macrophage deficiency of IGF1 on adipose tissue development, and the response to a chronic (high fat feeding) and acute (cold challenge) stress. Results The expression of Igf1 by adipose tissue is derived from multiple cell types including adipocytes and macrophages. In lean animals, adipocytes are the primary source of IGF1 but in obesity expression by adipocytes is reduced and by macrophages increased, so as to maintain overall adipose tissue Igf1 expression. Genetic deletion studies reveal that adipocyte-derived IGF1 regulates perigonadal but not subcutaneous adipose tissue mass during high fat feeding and the development of obesity. Conversely, macrophage-derived IGF1 acutely modulates PGAT (PGAT) mass during thermogenic challenges. Conclusions Local IGF1 is not required in lean adipose tissue development but required to maintain homeostasis during both chronic and acute metabolic stresses. PMID:26663512

  14. An analogue of atrial natriuretic peptide (C-ANP4-23) modulates glucose metabolism in human differentiated adipocytes.

    PubMed

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

    2016-08-15

    The present study was undertaken to investigate the effects of C-atrial natriuretic peptide (C-ANP4-23) in human adipose-derived stem cells differentiated into adipocytes over 10 days (1 μM for 4 h). The intracellular cAMP, cGMP and protein kinase A levels were determined by ELISA and gene and protein expression were determined by qRT-PCR and Western blot, respectively, in the presence or absence of C-ANP4-23. The levels of lipolysis and glucose uptake were also determined. C-ANP4-23 treatment significantly increased the intracellular cAMP levels and the gene expression of glucose transporter type 4 (GLUT4) and protein kinase, AMP-activated, alpha 1 catalytic subunit (AMPK). Western blot showed a significant increase in GLUT4 and phosphor-AMPKα levels. Importantly, the adenylate cyclase inhibitor SQ22536 abolished these effects. Additionally, C-ANP4-23 increased glucose uptake by 2-fold. Our results show that C-ANP4-23 enhances glucose metabolism and might contribute to the development of new peptide-based therapies for metabolic diseases.

  15. Tribbles 3 Inhibits Brown Adipocyte Differentiation and Function by Suppressing Insulin Signaling

    PubMed Central

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

    2016-01-01

    Recent studies have demonstrated that adult humans have substantial amounts of functioning brown adipose tissue (BAT). Since BAT has been implicated as an anti-obese and anti-diabetic tissue, it is important to understand the signaling molecules that regulate BAT function. There has been a link between insulin signaling and BAT metabolism as deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function. Tribbles 3 (TRB3) is a pseudo kinase that has been shown to regulate metabolism and insulin signaling in multiple tissues but the role of TRB3 in BAT has not been studied. In this study, we found that TRB3 expression was present in BAT and overexpression of TRB3 in brown preadipocytes impaired differentiation and decreased expression of BAT markers. Furthermore, TRB3 overexpression resulted in significantly lower oxygen consumption rates for basal and proton leakage, indicating decreased BAT activity. Based on previous studies showing that deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function, we assessed insulin signaling in brown preadipocytes and BAT in vivo. Overexpression of TRB3 in cells impaired insulin-stimulated IRS1 and Akt phosphorylation, whereas TRB3KO mice displayed improved IRS1 and Akt phosphorylation. Finally, deletion of IRS1 abolished the function of TRB3 to regulate BAT differentiation and metabolism. These data demonstrate that TRB3 inhibits insulin signaling in BAT, resulting in impaired differentiation and function. PMID:26801556

  16. FIZZ1-induced myofibroblast transdifferentiation from adipocytes and its potential role in dermal fibrosis and lipoatrophy.

    PubMed

    Martins, Vanessa; Gonzalez De Los Santos, Francina; Wu, Zhe; Capelozzi, Vera; Phan, Sem H; Liu, Tianju

    2015-10-01

    Subcutaneous lipoatrophy characteristically accompanies dermal fibrosis with de novo emergence of myofibroblasts such as in systemic sclerosis or scleroderma. Recently dermal adipocytes were shown to have the capacity to differentiate to myofibroblasts in an animal model. Transforming growth factor β can induce this phenomenon in vitro; however its in vivo significance is unclear. Because found in inflammatory zone 1 (FIZZ1) is an inducer of myofibroblast differentiation but an inhibitor of adipocyte differentiation, we investigated its potential role in adipocyte transdifferentiation to myofibroblast in dermal fibrosis. FIZZ1 caused significant and rapid suppression of the expression of fatty acid binding protein 4 and peroxisome proliferator-activated receptor-γ in adipocytes, consistent with dedifferentiation with loss of lipid and Oil Red O staining. The suppression was accompanied subsequently with stimulation of α-smooth muscle actin and type I collagen expression, indicative of myofibroblast differentiation. In vivo FIZZ1 expression was significantly elevated in the murine bleomycin-induced dermal fibrosis model, which was associated with significant reduction in adipocyte marker gene expression and subcutaneous lipoatrophy. Finally, FIZZ1 knockout mice exhibited significantly reduced bleomycin-induced dermal fibrosis with greater preservation of the subcutaneous fat than wild-type mice. These findings suggested that the FIZZ1 induction of adipocyte transdifferentiation to myofibroblast might be a key pathogenic mechanism for the accumulation of myofibroblasts in dermal fibrosis.

  17. Differential Effect of Plant Lipids on Membrane Organization

    PubMed Central

    Grosjean, Kevin; Mongrand, Sébastien; Beney, Laurent; Simon-Plas, Françoise; Gerbeau-Pissot, Patricia

    2015-01-01

    The high diversity of the plant lipid mixture raises the question of their respective involvement in the definition of membrane organization. This is particularly the case for plant plasma membrane, which is enriched in specific lipids, such as free and conjugated forms of phytosterols and typical phytosphingolipids, such as glycosylinositolphosphoceramides. This question was here addressed extensively by characterizing the order level of membrane from vesicles prepared using various plant lipid mixtures and labeled with an environment-sensitive probe. Fluorescence spectroscopy experiments showed that among major phytosterols, campesterol exhibits a stronger ability than β-sitosterol and stigmasterol to order model membranes. Multispectral confocal microscopy, allowing spatial analysis of membrane organization, demonstrated accordingly the strong ability of campesterol to promote ordered domain formation and to organize their spatial distribution at the membrane surface. Conjugated sterol forms, alone and in synergy with free sterols, exhibit a striking ability to order membrane. Plant sphingolipids, particularly glycosylinositolphosphoceramides, enhanced the sterol-induced ordering effect, emphasizing the formation and increasing the size of sterol-dependent ordered domains. Altogether, our results support a differential involvement of free and conjugated phytosterols in the formation of ordered domains and suggest that the diversity of plant lipids, allowing various local combinations of lipid species, could be a major contributor to membrane organization in particular through the formation of sphingolipid-sterol interacting domains. PMID:25575593

  18. Involvement of IGF-1 and MEOX2 in PI3K/Akt1/2 and ERK1/2 pathways mediated proliferation and differentiation of perivascular adipocytes

    SciTech Connect

    Liu, Ping; Kong, Feng; Wang, Jue; Lu, Qinghua; Xu, Haijia; Qi, Tonggang; Meng, Juan

    2015-02-01

    Perivascular adipocyte (PVAC) proliferation and differentiation were closely involved in cardiovascular disease. We aimed to investigate whether phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways enhance PVAC functions activated by insulin-like growth factor 1(IGF-1) and suppressed by mesenchyme homeobox 2 (MEOX2). In this study, PVACs from primary culture were cultured and induced to differentiate. Cell viability assays demonstrated that IGF-1 promoted PVAC proliferation and differentiation. However MEOX2 counteracted these IGF-1-mediated actions. Flow Cytometry revealed that IGF-1 increased S phase cells and decreased apoptosis; however, MEOX2 decreased S phase cells, increased G0–G1 phase cells, and promoted apoptosis. During PVAC proliferation and differentiation, IGF-1 activated PI3K/Akt1/2 and ERK1/2 signaling pathways, upregulated the expression of these signaling proteins and FAS, and increased PVAC lipid content. In contrast, MEOX2 constrained the phosphorylation of ERK1/2 and Akt1/2 protein, down-regulated these signaling molecules and FAS, and decreased PVAC lipid content. Instead, MEOX2 knockdown enhanced the ERK1/2 and Akt1/2 phosphorylation, augmented the expression of these signaling molecules and FAS, and increased PVAC lipid content. Our findings suggested that PI3K/Akt1/2 and ERK1/2 activation mediated by IGF-1 is essential for PVAC proliferation and differentiation, and MEOX2 is a promising therapeutic gene to intervene in the signaling pathways and inhibit PVAC functions. - Highlights: • IGF-1 activated PI3K/Akt2 and ERK1/2 pathways to mediate PVAC proliferation and differentiation. • The expression of ERK1, ERK 2, PI3K, Akt1 and Akt2 showed different change trends between PVAC proliferation and differentiation. • MEOX2 effectively expressed in PVAC, increased early and late cellular apoptosis, and inhibited its proliferation. • MEOX2 depressed PVAC differentiation and FAS expression

  19. Adipocyte Fatty Acid Binding Protein Potentiates Toxic Lipids-Induced Endoplasmic Reticulum Stress in Macrophages via Inhibition of Janus Kinase 2-dependent Autophagy

    PubMed Central

    Hoo, Ruby L. C.; Shu, Lingling; Cheng, Kenneth K. Y.; Wu, Xiaoping; Liao, Boya; Wu, Donghai; Zhou, Zhiguang; Xu, Aimin

    2017-01-01

    Lipotoxicity is implicated in the pathogenesis of obesity-related inflammatory complications by promoting macrophage infiltration and activation. Endoplasmic reticulum (ER) stress and adipocyte fatty acid binding protein (A-FABP) play key roles in obesity and mediate inflammatory activity through similar signaling pathways. However, little is known about their interplay in lipid-induced inflammatory responses. Here, we showed that prolonged treatment of palmitic acid (PA) increased ER stress and expression of A-FABP, which was accompanied by reduced autophagic flux in macrophages. Over-expression of A-FABP impaired PA-induced autophagy associating with enhanced ER stress and pro-inflammatory cytokine production, while genetic ablation or pharmacological inhibition of A-FABP reversed the conditions. PA-induced expression of autophagy-related protein (Atg)7 was attenuated in A-FABP over-expressed macrophages, but was elevated in A-FABP-deficient macrophages. Mechanistically, A-FABP potentiated the effects of PA by inhibition of Janus Kinase (JAK)2 activity, thus diminished PA-induced Atg7 expression contributing to impaired autophagy and further augmentation of ER stress. These findings suggest that A-FABP acts as autophagy inhibitor to instigate toxic lipids-induced ER stress through inhibition of JAK2-dependent autophagy, which in turn triggers inflammatory responses in macrophages. A-FABP-JAK2 axis may represent an important pathological pathway contributing to obesity-related inflammatory diseases. PMID:28094778

  20. Trans-10,cis-12 conjugated linoleic acid (CLA) interferes with lipid droplet accumulation during 3T3-L1 preadipocyte differentiation.

    PubMed

    Yeganeh, Azadeh; Taylor, Carla G; Tworek, Leslee; Poole, Jenna; Zahradka, Peter

    2016-07-01

    In this study, we hypothesize that the biologically active isomers of conjugated linoleic acid (CLA), cis-9,trans-11 (c9,t11) and trans-10,cis-12 (t10,c12) CLA, have different effects on early and late stages 3T3-L1 preadipocyte differentiation. Both c9-t11 and t10-c12CLA stimulated early stage pre-adipocyte differentiation (day 2), while t10-c12CLA inhibited late differentiation (day 8) as determined by lipid droplet numbers and both perilipin-1 levels and phosphorylation state. At day 8, the adipokines adiponectin, chemerin and adipsin were all reduced in t10-c12CLA treated cells versus control cells. Immunofluorescence microscopy showed perilipin-1 was present solely on lipid droplets on day 8 in t10-c12 treated 3T3-L1 cells, whereas preilipin-1 was also located in the perinuclear region in control and c9-t11 treated cells. The t10-c12CLA isomer also decreased levels of hormone-sensitive lipase and inhibited lipolysis. These findings indicate that the decrease in lipid droplets caused by t10-c12CLA is the result of an inhibition of lipid droplet production during adipogenesis rather than a stimulation of lipolysis. Additionally, treatment with Gö6976 blocked the effect of t10-c12CLA on perilipin-1 phosphorylation, implicating PKCα in perilipin-1 phosphorylation, and thus a regulator of triglyceride catabolism. These data are supported by evidence that t10-c12CLA activated PKCα. These are the first data to show that CLA isomers can affect lipid droplet dynamics in adipocytes through PKCα.

  1. Induction of Dlk1 by PTTG1 inhibits adipocyte differentiation and correlates with malignant transformation.

    PubMed

    Espina, Agueda G; Méndez-Vidal, Cristina; Moreno-Mateos, Miguel A; Sáez, Carmen; Romero-Franco, Ana; Japón, Miguel A; Pintor-Toro, José A

    2009-07-01

    Pituitary tumor-transforming gene-1 (PTTG1) is an oncogene highly expressed in a variety of endocrine, as well as nonendocrine-related cancers. Several tumorigenic mechanisms for PTTG1 have been proposed, one of the best characterized being its capacity to act as a transcriptional activator. To identify novel downstream target genes, we have established cell lines with inducible expression of PTTG1 and a differential display approach to analyze gene expression changes after PTTG1 induction. We identified dlk1 (also known as pref-1) as one of the most abundantly expressed PTTG1 targets. Dlk1 is known to participate in several differentiation processes, including adipogenesis, adrenal gland development, and wound healing. Dlk1 is also highly expressed in neuroendocrine tumors. Here, we show that PTTG1 overexpression inhibits adipogenesis in 3T3-L1 cells and that this effect is accomplished by promoting the stability and accumulation of Dlk1 mRNA, supporting a role for PTTG1 in posttranscriptional regulation. Moreover, both pttg1 and dlk1 genes show concomitant expression in fetal liver and placenta, as well as in pituitary adenomas, breast adenocarcinomas, and neuroblastomas, suggesting that PTTG1 and DLK1 are involved in cell differentiation and transformation.

  2. Peanut sprout ethanol extract inhibits the adipocyte proliferation, differentiation, and matrix metalloproteinases activities in mouse fibroblast 3T3-L1 preadipocytes.

    PubMed

    Kim, Woo Kyoung; Kang, Nam E; Kim, Myung Hwan; Ha, Ae Wha

    2013-06-01

    3T3-L1 preadipocyte were differentiated to adipocytes, and then treated with 0, 10, 20, and 40 µg/mL of peanut sprout ethanol extract (PSEE). The main component of PSEE is resveratrol which contained 5.55 mg/mL of resveratrol. The MTT assay, Oil-Red O staining, glycerol-3-phosphate dehydrogenase (GPDH) activity, and the triglyceride concentration were determined in 3T3-L1 cells. MMP-2 and MMP-9 activities as well as mRNA expressions of C/EBP β and C/EBP α were also investigated. As the concentration of PSEE in adipocytes increased, the cell proliferation was decreased in a dose-dependent manner from 4 days of incubation (P < 0.05). The GDPH activity (P < 0.05) and the triglyceride concentration (P < 0.05) were decreased as the PSEE treatment concentration increased. The mRNA expression of C/EBPβ in 3T3-L1 cells was significantly low in groups of PSEE-treated, compared with control group (P < 0.05). The MMP-9 (P < 0.05) and MMP-2 (P < 0.05) activities were decreased in a dose-dependent manner as the PSEE concentration increased from 20 µg/mL. In conclusion, it was found that PSEE has an effect on restricting proliferation and differentiation of adipocytes.

  3. Novel flow cytometric approach for the detection of adipocyte subpopulations during adipogenesis[S

    PubMed Central

    Durandt, Chrisna; van Vollenstee, Fiona A.; Dessels, Carla; Kallmeyer, Karlien; de Villiers, Danielle; Murdoch, Candice; Potgieter, Marnie; Pepper, Michael S.

    2016-01-01

    The ability of mesenchymal stromal cells (MSCs) to differentiate into adipocytes provides a cellular model of human origin to study adipogenesis in vitro. One of the major challenges in studying adipogenesis is the lack of tools to identify and monitor the differentiation of various subpopulations within the heterogeneous pool of MSCs. Cluster of differentiation (CD)36 plays an important role in the formation of intracellular lipid droplets, a key characteristic of adipocyte differentiation/maturation. The objective of this study was to develop a reproducible quantitative method to study adipocyte differentiation by comparing two lipophilic dyes [Nile Red (NR) and Bodipy 493/503] in combination with CD36 surface marker staining. We identified a subpopulation of adipose-derived stromal cells that express CD36 at intermediate/high levels and show that combining CD36 cell surface staining with neutral lipid-specific staining allows us to monitor differentiation of adipose-derived stromal cells that express CD36intermediate/high during adipocyte differentiation in vitro. The gradual increase of CD36intermediate/high/NRpositive cells during the 21 day adipogenesis induction period correlated with upregulation of adipogenesis-associated gene expression. PMID:26830859

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

    PubMed Central

    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

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

    PubMed Central

    Yang, Soo Jin; Park, Na-Young

    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-L1 adipocytes were treated with different doses of MLEE for 8 days starting 2 days post-confluence. Cell viability, fat accumulation, and adipogenesis-related factors including CCAAT-enhancer-binding protein alpha (C/EBPα), peroxisome proliferator-activated receptor gamma (PPARγ), PPARγ coactivator 1 alpha (PGC-1α), fatty acid synthase (FAS), and adiponectin were analyzed. RESULTS Results showed that MLEE treatments at 10, 25, 50, and 100 µg/ml had no effect on cell morphology and viability. Without evident toxicity, all MLEE treated cells had lower fat accumulation compared with control as shown by lower absorbances of Oil Red O stain. MLEE at 50 and 100 µg/ml significantly reduced protein levels of PPARγ, PGC-1α, FAS, and adiponectin in differentiated adipocytes. Furthermore, protein level of C/EBPα was significantly decreased by the treatment of 100 µg/ml MLEE. CONCLUSION These results demonstrate that MLEE treatment has an anti-adipogenic effect in differentiated adipocytes without toxicity, suggesting its potential as an anti-obesity therapeutic. PMID:25489399

  6. Signal transducer and activator of transcription 5B (STAT5B) modulates adipocyte differentiation via MOF.

    PubMed

    Gao, Peng; Zhang, Yuchao; Liu, Yuantao; Chen, Jicui; Zong, Chen; Yu, Cong; Cui, Shang; Gao, Weina; Qin, Dandan; Sun, Wenchuan; Li, Xia; Wang, Xiangdong

    2015-12-01

    The role and mechanism of signal transducer and activator of transcription 5B (STAT5B) in adipogenesis remain unclear. In this study, our data showed that Males absent on the first (MOF) protein expression was increased during 3 T3-L1 preadipocytes differentiation accompanied with STAT5B expression increasing. Over-expression STAT5B enhanced MOF promoter trans-activation in HeLa cells. Mutagenesis assay and ChIP analysis exhibited that STAT5B was able to bind MOF promoter. Knocking-down STAT5B in 3 T3-L1 preadipocytes led to decreased expression of MOF, but resulted in increased expression of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα) and fatty acid-binding protein 4 (Fabp4), which were important factors or enzymes for adipogenesis. We also found that knocking-down MOF in 3 T3-L1 preadipocytes resulted in increased expression of PPARγ, C/EBPα and Fabp4, which was in the same trend as STAT5B knocking-down. Over-expression MOF resulted in reduced promoter trans-activation activity of C/EBPα. These results suggest that STAT5B and MOF work as negative regulators in adipogenesis, and STAT5B modulates preadipocytes differentiation partially by regulating MOF expression.

  7. Modulation of adipocyte biology by δ(9)-tetrahydrocannabinol.

    PubMed

    Teixeira, Diana; Pestana, Diogo; Faria, Ana; Calhau, Conceição; Azevedo, Isabel; Monteiro, Rosário

    2010-11-01

    It is recognized that the endocannabinoid system (ECS) plays a crucial role in the modulation of food intake and other aspects of energy metabolism. In this study, we aimed to investigate the effects of Δ(9)-tetrahydrocannabinol (THC) on adipocyte biology. 3T3-L1 cells were used to evaluate proliferation by sulforhodamine B (SRB) staining and methyl-(3)H-thymidine incorporation after 48 or 72 h of treatment with THC (1-500 nmol/l). Cells were differentiated in the presence or absence of the cannabinoid, and adipogenesis was determined by measuring lipid accumulation and peroxisome proliferator-activated receptor γ (PPARγ) transcription through reverse transcriptase-PCR (RT-PCR). Lipolysis was quantified under basal conditions or after isoproterenol (IP, 100 nmol/l) or insulin (INS, 100 nmol/l) treatment. Transforming growth factor β (TGFβ), diacylglycerol lipase α, and N-acylphosphatidylethanolamine-specific phospholipase D (NAPE-PLD) transcriptions were determined by RT-PCR in preadipocytes and adipocytes and adiponectin only in adipocytes. THC treatment increased culture protein content and reduced methyl-(3)H-thymidine incorporation. Cells treated with THC underwent adipogenesis shown by the expression of PPARγ and had increased lipid accumulation. Basal and IP-stimulated lipolyses were inhibited by THC and there was no effect on lipolysis of INS-treated adipocytes. The effects on methyl-(3)H-thymidine incorporation and lipolysis seem to be mediated through CB1- and CB2-dependent pathways. THC decreased NAPE-PLD in preadipocytes and increased adiponectin and TGFβ transcription in adipocytes. These results show that the ECS interferes with adipocyte biology and may contribute to adipose tissue (AT) remodeling. Although these observations point toward increased AT deposition, the stimulation of adiponectin production and inhibition of lipolysis may be in favor of improved INS sensitivity under cannabinoid influence.

  8. [The dynamic mitochondria-nuclear redistribution of FKBP51 during the process of adipocyte differentiation is regulated by PKA].

    PubMed

    Toneatto, Judith; Charó, Nancy L; Susperreguy, Sebastián; Piwien-Pilipuk, Graciela

    2013-01-01

    Glucocorticoids play an important role in adipogenesis via the glucocorticoid receptor (GR) that forms a heterocomplex with Hsp90-Hsp70 and a high molecular weight immunophilin FKBP51 or FKBP52. We have found that FKBP51 level of expression progressively increases, FKBP52 decreases, whereas Hsp90, Hsp70, and p23 remain unchanged when 3T3-L1 preadipocytes differentiate. Interestingly, FKBP51 translocates from mitochondria to the nucleus at the onset of adipogenesis. FKBP51 transiently concentrates in the nuclear lamina, at a time that this nuclear compartment undergoes its reorganization. FKBP51 nuclear localization is transient, after 48 h it cycles back to mitochondria. We found that the dynamic FKBP51 mitochondrial-nuclear shuttling is regulated by glucocorticoids and mainly on cAMP-PKA signaling since PKA inhibition by myristoilated-PKI, abrogated FKBP51 nuclear translocation induced by 3-isobutyl-1-methylxanthine (IBMX). It has been reported that PKA interacts with GR in a ligand dependent manner potentiating its transcriptional capacity. GR transcriptional capacity is reduced when cells are incubated in the presence of IBMX, forskolin or dibutyryl-cAMP, compounds that induced nuclear translocation of FKBP51, therefore PKA may exert a dual role in the control of GR. In summary, the presence of FKBP51 in the nucleus may be critical for GR transcriptional control, and possibly for the control of other transcription factors that are not members of the nuclear receptor family but are regulated by PKA signaling pathway, when transcription has to be strictly controlled to succeed in the acquisition of the adipocyte phenotype.

  9. Glycine suppresses TNF-α-induced activation of NF-κB in differentiated 3T3-L1 adipocytes.

    PubMed

    Blancas-Flores, Gerardo; Alarcón-Aguilar, Francisco J; García-Macedo, Rebeca; Almanza-Pérez, Julio C; Flores-Sáenz, José L; Román-Ramos, Rubén; Ventura-Gallegos, José L; Kumate, Jesús; Zentella-Dehesa, Alejandro; Cruz, Miguel

    2012-08-15

    Glycine strongly reduces the serum levels of pro-inflammatory cytokines and increases the levels of anti-inflammatory cytokines. Recently, glycine has been shown to decrease the expression and secretion of pro-inflammatory adipokines in monosodium glutamate-induced obese (MSG/Ob) mice. It has been postulated that these effects may be explained by a reduction in nuclear factor kappa B (NF-κB) activation. NF-κB is a transcription factor, which is crucial to the inflammatory response. Hasegawa et al. (2011 and 2012) recently reported a glycine-dependent reduction in NF-κB levels. Here, we have investigated the role of glycine in the regulation of NF-κB in differentiated 3T3-L1 adipocytes. The results revealed that pretreatment with glycine interfered with the activation of NF-κB, which has been shown to be stimulated by tumor necrosis factor-alpha (TNF-α). Glycine alone stimulated NF-κB activation in an unusual way such that the inhibitor κB-β (IκB-β) degradation was more significant than that of the inhibitor κB-α (IκB-α) and led to NF-κB complexes comprised of p50 and p65 subunits; IκB-ε degradation did not affect by glycine. These findings suggest that glycine could be used as an alternative treatment for chronic inflammation, which is a hallmark of obesity and other comorbidities, and is characterized by an elevated production of pro-inflammatory cytokines.

  10. Cellular and Molecular Implications of Mature Adipocyte Dedifferentiation

    PubMed Central

    Wei, Shengjuan; Duarte, Marcio S.; Zan, Linsen; Du, Min; Jiang, Zhihua; Guan, LeLuo; Chen, Jie; Hausman, Gary J.; Dodson, Michael V.

    2013-01-01

    There is a voluminous amount of scientific literature dealing with the involvement of adipocytes in molecular regulation of carcass composition, obesity, metabolic syndrome, or diabetes. To form adipocytes (process termed adipogenesis) nearly all scientific papers refer to the use of preadipocytes, adipofibroblasts, stromal vascular cells or adipogenic cell lines, and their differentiation to form lipid-assimilating cells containing storage triacylglyceride. However, mature adipocytes, themselves, possess ability to undergo dedifferentiation, form proliferative-competent progeny cells (the exact plasticity is unknown) and reinitiate formation of cells capable of lipid metabolism and storage. The progeny cells would make a viable (and alternative) cell system for the evaluation of cell ability to reestablish lipid assimilation, ability to differentially express genes (as compared to other adipogenic cells), and to form other types of cells (multi-lineage potential). Understanding the dedifferentiation process itself and/or dedifferentiated fat cells could contribute to our knowledge of normal growth processes, or to disease function. Indeed, the ability of progeny cells to form other cell types could turn-out to be important for processes of tissue reconstruction/engineering and may have implications in clinical, biochemical or molecular processes. PMID:25031650

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

    SciTech Connect

    Hinoi, Eiichi; Iezaki, Takashi; Ozaki, Kakeru; Yoneda, Yukio

    2014-10-03

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

  12. Progeny from dedifferentiated adipocytes display protracted adipogenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Progeny of adipofibroblast cells, derived from mature bovine adipocytes, were used to determine their ability to redifferentiate into lipid-assimilating adipocytes. Traditional cell biology methods were used, including the expression of adipogenic markers such as PPAR'. When exposed to medium supple...

  13. Tenomodulin promotes human adipocyte differentiation and beneficial visceral adipose tissue expansion

    PubMed Central

    Senol-Cosar, Ozlem; Flach, Rachel J. Roth; DiStefano, Marina; Chawla, Anil; Nicoloro, Sarah; Straubhaar, Juerg; Hardy, Olga T.; Noh, Hye Lim; Kim, Jason K.; Wabitsch, Martin; Scherer, Philipp E.; Czech, Michael P.

    2016-01-01

    Proper regulation of energy storage in adipose tissue is crucial for maintaining insulin sensitivity and molecules contributing to this process have not been fully revealed. Here we show that type II transmembrane protein tenomodulin (TNMD) is upregulated in adipose tissue of insulin-resistant versus insulin-sensitive individuals, who were matched for body mass index (BMI). TNMD expression increases in human preadipocytes during differentiation, whereas silencing TNMD blocks adipogenesis. Upon high-fat diet feeding, transgenic mice overexpressing Tnmd develop increased epididymal white adipose tissue (eWAT) mass, and preadipocytes derived from Tnmd transgenic mice display greater proliferation, consistent with elevated adipogenesis. In Tnmd transgenic mice, lipogenic genes are upregulated in eWAT, as is Ucp1 in brown fat, while liver triglyceride accumulation is attenuated. Despite expanded eWAT, transgenic animals display improved systemic insulin sensitivity, decreased collagen deposition and inflammation in eWAT, and increased insulin stimulation of Akt phosphorylation. Our data suggest that TNMD acts as a protective factor in visceral adipose tissue to alleviate insulin resistance in obesity. PMID:26880110

  14. Soyasaponins Aa and Ab exert an anti-obesity effect in 3T3-L1 adipocytes through downregulation of PPARγ.

    PubMed

    Yang, Seung Hwan; Ahn, Eun-Kyung; Lee, Jung A; Shin, Tai-Sun; Tsukamoto, Chigen; Suh, Joo-won; Mei, Itabashi; Chung, Gyuhwa

    2015-02-01

    Saponins are a diverse group of biologically functional products in plants. Soyasaponins are usually glycosylated, which give rise to a wide diversity of structures and functions. In this study, we investigated the effects and molecular mechanism of soyasaponins Aa and Ab in regulating adipocyte differentiation and expression of adipogenic marker genes in 3T3-L1 adipocytes. Soyasaponins Aa and Ab dose-dependently inhibited the accumulation of lipids and the expression of adiponectin, adipocyte determination and differentiation factor 1/sterol regulatory element binding protein 1c, adipocyte fatty acid-binding protein 2, fatty acid synthase, and resistin in 3T3-L1 adipocytes. In addition, soyasaponins Aa and Ab suppressed the transcriptional activity of peroxisome proliferator-activated receptor γ (PPARγ) in HEK 293T cells. Furthermore, we confirmed that the expression of PPARγ and of CCAAT-enhancer-binding protein α (C/EBPα) was suppressed at both the mRNA and protein levels in 3T3-L1 adipocytes by treatment with soyasaponins Aa and Ab. Taken together, these findings indicate that soyasaponin Aa and Ab markedly inhibit adipocyte differentiation and expression of various adipogenic marker genes through the downregulation of the adipogenesis-related transcription factors PPARγ and C/EBPα in 3T3-L1 adipocytes.

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

    PubMed

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

    2016-01-01

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

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

    SciTech Connect

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

    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.

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

    SciTech Connect

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

    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.

  18. Adlay seed extract (Coix lachryma-jobi L.) decreased adipocyte differentiation and increased glucose uptake in 3T3-L1 cells.

    PubMed

    Ha, Do Thi; Nam Trung, Trinh; Bich Thu, Nguyen; Van On, Tran; Hai Nam, Nguyen; Van Men, Chu; Thi Phuong, Tran; Bae, KiHwan

    2010-12-01

    The aim of the present study was to investigate effects of the ethyl acetate fraction of an ethanol extract of Coix lachryma-jobi (ECLJ) on glucose uptake and adipocyte differentiation in 3T3-L1 cells. ECLJ phosphorylated AMP-activated protein kinase (AMPK) and its downstream substrate acetyl-coenzymeA carboxylase in 3T3-L1 cells in a time- and dose-dependent manner. Moreover, we discovered that compound C inhibits ECLJ-stimulated ACC phosphorylation. In addition, ECLJ exhibited a dose-dependent stimulation of glucose uptake in 3T3-L1 cells, and this increase was obviously attenuated by compound C. ECLJ also caused a decrease in the expression levels of adipogenesis factors such as fatty acid synthase, sterol-regulatory-element-binding protein-1c, peroxisome proliferator-activated receptor γ, and CAATT/enhancer binding protein α in a dose-dependent manner. Differentiation was examined by Oil red O staining activity after ECLJ treatment for 6 days. ECLJ decreased mean droplet size. These results suggest a possible role for AMPK in the process of adipose differentiation and that ECLJ targeted for adipocyte functions could be effective in improving the symptoms of metabolic syndrome.

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

    PubMed

    Cereijo, Rubén; Gallego-Escuredo, José Miguel; Moure, Ricardo; Villarroya, Joan; Domingo, Joan Carles; Fontdevila, Joan; Martínez, Esteban; Gutiérrez, Maria del Mar; Mateo, María Gracia; Giralt, Marta; Domingo, Pere; Villarroya, Francesc

    2015-01-01

    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 appears unique of

  20. Involvement of JNK/NFκB Signaling Pathways in the Lipopolysaccharide-Induced Modulation of Aquaglyceroporin Expression in 3T3-L1 Cells Differentiated into Adipocytes

    PubMed Central

    Chiadak, Jeanne Durendale; Arsenijevic, Tatjana; Gregoire, Francoise; Bolaky, Nargis; Delforge, Valerie; Perret, Jason; Delporte, Christine

    2016-01-01

    Aquaglyceroporins, belonging to the family of aquaporins (AQPs), are integral plasma membrane proteins permeable to water and glycerol that have emerged as key players in obesity. The aim of this study was to investigate the expression profile of AQPs in undifferentiated and differentiated 3T3-L1 cells and to investigate the changes in expression of aquaglyceroporins in 3T3-L1 cells differentiated into adipocytes and subjected to lipopolysaccharide (LPS) mimicking inflammation occurring during obesity. Furthermore, the study aimed at identifying the signaling cascade involved in the regulation of aquaglyceroporins expression upon LPS stimulation. 3T3-L1 cells were grown as undifferentiated cells (UDC; preadipocytes) or cells differentiated into adipocytes (DC, adipocytes). DC were incubated in the presence or absence of LPS with or without inhibitors of various protein kinases. AQPs mRNA expression levels were measured by real-time quantitative polymerase chain reaction (RT-qPCR). AQP1, AQP2, AQP3, AQP9 and AQP11 mRNA were expressed in both UDC and DC, whereas AQP4, AQP7 and AQP8 mRNA were expressed only in DC. In DC, LPS up-regulated AQP3 mRNA levels (p < 0.05) compared to control; these effects were inhibited by CLI095, SP600125 and BAY11-7082 (p < 0.05). LPS decreased both AQP7 and AQP11 mRNA levels (p < 0.01) in DC as compared to control; this decrease was inhibited by CLI095 and BAY11-7082 (p < 0.05) and additionally by SP00125 for AQP7 (p < 0.05). SB203580 had no effect on LPS-induced AQP3, AQP7 and AQP11 mRNA levels modulations. In conclusion, our results clearly show that many AQPs are expressed in murine 3T3-L1 adipocytes. Moreover, in DCs, LPS led to decreased AQP7 and AQP11 mRNA levels but to increased AQP3 mRNA levels, resulting from the Toll-like receptor 4 (TLR4)-induced activation of JNK and/or NFκB pathway. PMID:27763558

  1. Adipocyte induced arterial calcification is prevented with sodium thiosulfate

    SciTech Connect

    Chen, Neal X.; O’Neill, Kalisha; Akl, Nader Kassis; Moe, Sharon M.

    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

  2. A commercial formulation of glyphosate inhibits proliferation and differentiation to adipocytes and induces apoptosis in 3T3-L1 fibroblasts.

    PubMed

    Martini, Claudia N; Gabrielli, Matías; Vila, María del C

    2012-09-01

    Glyphosate-based herbicides are extensively used for weed control all over the world. Therefore, it is important to investigate the putative toxic effects of these formulations which include not only glyphosate itself but also surfactants that may also be toxic. 3T3-L1 fibroblasts are a useful tool to study adipocyte differentiation, this cell line can be induced to differentiate by addition of a differentiation mixture containing insulin, dexamethasone and 3-isobutyl-1-methylxanthine. We used this cell line to investigate the effect of a commercial formulation of glyphosate (GF) on proliferation, survival and differentiation. It was found that treatment of exponentially growing cells with GF for 48h inhibited proliferation in a dose-dependent manner. In addition, treatment with GF dilution 1:2000 during 24 or 48h inhibited proliferation and increased cell death, as evaluated by trypan blue-exclusion, in a time-dependent manner. We showed that treatment of 3T3-L1 fibroblasts with GF increased caspase-3 like activity and annexin-V positive cells as evaluated by flow cytometric analysis, which are both indicative of induction of apoptosis. It was also found that after the removal of GF, remaining cells were able to restore proliferation. On the other hand, GF treatment severely inhibited the differentiation of 3T3-L1 fibroblasts to adipocytes. According to our results, a glyphosate-based herbicide inhibits proliferation and differentiation in this mammalian cell line and induces apoptosis suggesting GF-mediated cellular damage. Thus, GF is a potential risk factor for human health and the environment.

  3. Glucose-dependent insulinotropic polypeptide promotes lipid deposition in subcutaneous adipocytes in obese type 2 diabetes patients: a maladaptive response.

    PubMed

    Thondam, Sravan K; Daousi, Christina; Wilding, John P H; Holst, Jens J; Ameen, Gulizar I; Yang, Chenjing; Whitmore, Catherine; Mora, Silvia; Cuthbertson, Daniel J

    2017-03-01

    Glucose-dependent insulinotropic polypeptide (GIP) beyond its insulinotropic effects may regulate postprandial lipid metabolism. Whereas the insulinotropic action of GIP is known to be impaired in type 2 diabetes mellitus (T2DM), its adipogenic effect is unknown. We hypothesized that GIP is anabolic in human subcutaneous adipose tissue (SAT) promoting triacylglycerol (TAG) deposition through reesterification of nonesterified fatty acids (NEFA), and this effect may differ according to obesity status or glucose tolerance. Twenty-three subjects categorized into four groups, normoglycemic lean (n = 6), normoglycemic obese (n = 6), obese with impaired glucose regulation (IGR; n = 6), and obese T2DM (n = 5), participated in a double-blind, randomized, crossover study involving a hyperglycemic clamp with a 240-min GIP infusion (2 pmol·kg(-1)·min(-1)) or normal saline. Insulin, NEFA, SAT-TAG content, and gene expression of key lipogenic enzymes were determined before and immediately after GIP/saline infusions. GIP lowered NEFA concentrations in the obese T2DM group despite diminished insulinotropic activity (mean NEFA AUC0-4 h ± SE, 41,992 ± 9,843 µmol·l(-1)·min(-1) vs. 71,468 ± 13,605 with placebo, P = 0.039, 95% CI: 0.31-0.95). Additionally, GIP increased SAT-TAG in obese T2DM (1.78 ± 0.4 vs 0.86 ± 0.1-fold with placebo, P = 0.043, 95% CI: 0.1-1.8). Such effect with GIP was not observed in other three groups despite greater insulinotropic activity. Reduction in NEFA concentration with GIP correlated with adipose tissue insulin resistance for all subjects (Pearson, r = 0.56, P = 0.005). There were no significant gene expression changes in key SAT lipid metabolism enzymes. In conclusion, GIP appears to promote fat accretion and thus may exacerbate obesity and insulin resistance in T2DM.

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

    PubMed

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

    2013-01-01

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

  5. Insulin stimulates actin comet tails on intracellular GLUT4-containing compartments in differentiated 3T3L1 adipocytes.

    PubMed

    Kanzaki, M; Watson, R T; Khan, A H; Pessin, J E

    2001-12-28

    Incubation of isolated GLUT4-containing vesicles with Xenopus oocyte extracts resulted in a guanosine 5'-[gamma-thio]triphosphate (GTP gamma S) and sodium orthovanadate stimulation of actin comet tails. The in vitro actin-based GLUT4 vesicle motility was inhibited by both latrunculin B and a dominant-interfering N-WASP mutant, N-WASP/Delta VCA. Preparations of gently sheared (broken) 3T3L1 adipocytes also displayed GTP gamma S and sodium orthovanadate stimulation of actin comet tails on GLUT4 intracellular compartments. Furthermore, insulin pretreatment of intact adipocytes prior to gently shearing also resulted in a marked increase in actin polymerization and actin comet tailing on GLUT4 vesicles. In addition, the insulin stimulation of actin comet tails was completely inhibited by Clostridum difficile toxin B, demonstrating a specific role for a Rho family member small GTP-binding protein. Expression of N-WASP/Delta VCA in intact cells had little effect on adipocyte cortical actin but partially inhibited insulin-stimulated GLUT4 translocation. Taken together, these data demonstrate that insulin can induce GLUT4 vesicle actin comet tails that are necessary for the efficient translocation of GLUT4 from intracellular storage sites to the plasma membrane.

  6. Conjugated Linoleic Acid Induces Human Adipocyte Delipidation

    PubMed Central

    Brown, J. Mark; Boysen, Maria Sandberg; Chung, Soonkyu; Fabiyi, Olowatoyin; Morrison, Ron F.; Mandrup, Susanne; McIntosh, Michael K.

    2005-01-01

    Dietary conjugated linoleic acid (CLA) reduces body fat in animals and some humans. Here we show that trans-10, cis-12 CLA, but not cis-9, trans-11 CLA, when added to cultures of stromal vascular cells containing newly differentiated human adipocytes, caused a time-dependent decrease in triglyceride content, insulin-stimulated glucose and fatty acid uptake, incorporation into lipid, and oxidation compared with controls. In parallel, gene expression of peroxisome proliferator-activated receptor-γ and many of its downstream targets were diminished by trans-10, cis-12 CLA, whereas leptin gene expression was increased. Prior to changes in gene expression and metabolism, trans-10, cis-12 CLA caused a robust and sustained activation of mitogen-activated protein kinase kinase/extracellular signal-related kinase (MEK/ERK) signaling. Furthermore, the trans-10, cis-12 CLA-mediated activation of MEK/ERK could be attenuated by pretreatment with U0126 and pertussis toxin. In parallel, pretreatment with U0126 blocked the ability of trans-10, cis-12 CLA to alter gene expression and attenuate glucose and fatty acid uptake of the cultures. Intriguingly, the induction by CLA of MEK/ERK signaling was linked to hypersecretion of adipocytokines interleukin-6 and interleukin-8. Collectively, these data demonstrate for the first time that trans-10, cis-12 CLA decreases the triglyceride content of newly differentiated human adipocytes by inducing MEK/ERK signaling through the autocrine/paracrine actions of interleukins-6 and 8. PMID:15067015

  7. Bixin regulates mRNA expression involved in adipogenesis and enhances insulin sensitivity in 3T3-L1 adipocytes through PPAR{gamma} activation

    SciTech Connect

    Takahashi, Nobuyuki; Goto, Tsuyoshi; Taimatsu, Aki; Egawa, Kahori; Katoh, Sota; Kusudo, Tatsuya; Sakamoto, Tomoya; Ohyane, Chie; Lee, Joo-Young; Kim, Young-il; Uemura, Taku; Hirai, Shizuka; Kawada, Teruo

    2009-12-25

    Insulin resistance is partly due to suppression of insulin-induced glucose uptake into adipocytes. The uptake is dependent on adipocyte differentiation, which is controlled at mRNA transcription level. The peroxisome proliferator-activated receptor (PPAR), a ligand-regulated nuclear receptor, is involved in the differentiation. Many food-derived compounds serve as ligands to activate or inactivate PPAR. In this study, we demonstrated that bixin and norbixin (annatto extracts) activate PPAR{gamma} by luciferase reporter assay using GAL4-PPAR chimera proteins. To examine the effects of bixin on adipocytes, 3T3-L1 adipocytes were treated with bixin or norbixin. The treatment induced mRNA expression of PPAR{gamma} target genes such as adipocyte-specific fatty acid-binding protein (aP2), lipoprotein lipase (LPL), and adiponectin in differentiated 3T3-L1 adipocytes and enhanced insulin-dependent glucose uptake. The observations indicate that bixin acts as an agonist of PPAR{gamma} and enhances insulin sensitivity in 3T3-L1 adipocytes, suggesting that bixin is a valuable food-derived compound as a PPAR ligand to regulate lipid metabolism and to ameliorate metabolic syndrome.

  8. Dexamethasone and rosiglitazone are sufficient and necessary for producing functional adipocytes from mesenchymal stem cells.

    PubMed

    Contador, David; Ezquer, Fernando; Espinosa, Maximiliano; Arango-Rodriguez, Martha; Puebla, Carlos; Sobrevia, Luis; Conget, Paulette

    2015-09-01

    The final product of adipogenesis is a functional adipocyte. This mature cell acquires the necessary machinery for lipid metabolism, loses its proliferation potential, increases its insulin sensitivity, and secretes adipokines. Multipotent mesechymal stromal cells have been recognized as a source of adipocytes both in vivo and in vitro. The in vitro adipogenic differentiation of human MSC (hMSC) has been induced up to now by using a complex stimulus which includes dexamethasone, 3-isobutyl-1-methylxanthine, indomethacin, and insulin (a classical cocktail) and evaluated according to morphological changes. The present work was aimed at demonstrating that the simultaneous activation of dexamethasone's canonical signaling pathways, through the glucocorticoid receptor and CCAAT-enhancer-binding proteins (C/EBPs) and rosiglitazone through peroxisome proliferator-activated receptor gamma (PPAR-gamma) is sufficient yet necessary for inducing hMSC adipogenic differentiation. It was also ascertained that hMSC exposed just to dexamethasone and rosiglitazone (D&R) differentiated into cells which accumulated neutral lipid droplets, expressed C/EBP-alpha, PPAR-gamma, aP2, lipoprotein lipase, acyl-CoA synthetase, phosphoenolpyruvate carboxykinase, adiponectin, and leptin genes but did not proliferate. Glucose uptake was dose dependent on insulin stimulus and high levels of adipokines were secreted (i.e. displaying not only the morphology but also expressing mature adipocytes' specific genes and functional characteristics). This work has demonstrated that (i) the activating C/EBPs and PPAR-gamma signaling pathways were sufficient to induce adipogenic differentiation from hMSC, (ii) D&R producing functional adipocytes from hMSC, (iii) D&R induce adipogenic differentiation from mammalian MSC (including those which are refractory to classical adipogenic differentiation stimuli). D&R would thus seem to be a useful tool for MSC characterization, studying adipogenesis pathways and

  9. The transcription factors myeloid elf-1-like factor (MEF) and distal-less homeobox 5 (Dlx5) inversely regulate the differentiation of osteoblasts and adipocytes in bone marrow.

    PubMed

    Baek, Kyunghwa; Baek, Jeong-Hwa

    2013-01-01

    In bone marrow, the differentiation of osteoblasts and adipocytes is reciprocally regulated. This inverse regulation occurs mainly through complex signaling crosstalk between transcriptional factors such as peroxisome proliferator-activated receptor-γ (PPARγ) and runt-related transcription factor 2 (Runx2). This commentary addresses the role of myeloid elf-1 like factor (MEF) and distal-less homeobox 5 (Dlx5) in the lineage commitment of bone marrow mesenchymal stem cells into adipocytes and osteoblasts, respectively. MEF suppresses osteoblastogenesis by preventing Runx2 from binding to the promoters of target genes and enhancing adipogenesis via transactivation of PPARγ expression. Conversely, Dlx5 enhances osteoblastogenesis through upregulation of the expression of Runx2 and osteoblast marker genes while suppressing adipogenesis through the downregulation of PPARγ expression by sequestering the cAMP response element binding protein and CCAAT/enhancer-binding protein α. Studies designed to examine the effects of physiological and pathologic signals on the expression of MEF and Dlx5 will provide further insight to the function of these transcription factors in vivo.

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

    PubMed Central

    Cereijo, Rubén; Gallego-Escuredo, José Miguel; Moure, Ricardo; Villarroya, Joan; Domingo, Joan Carles; Fontdevila, Joan; Martínez, Esteban; Gutiérrez, Maria del Mar; Mateo, María Gracia; Giralt, Marta; Domingo, Pere; Villarroya, Francesc

    2015-01-01

    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

  11. Effects of cardiotrophin on adipocytes.

    PubMed

    Zvonic, Sanjin; Hogan, Jessica C; Arbour-Reily, Patricia; Mynatt, Randall L; Stephens, Jacqueline M

    2004-11-12

    Cardiotrophin (CT-1) is a naturally occurring protein member of the interleukin (IL)-6 cytokine family and signals through the gp130/leukemia inhibitory factor receptor (LIFR) heterodimer. The formation of gp130/LIFR complex triggers the auto/trans-phosphorylation of associated Janus kinases, leading to the activation of Janus kinase/STAT and MAPK (ERK1 and -2) signaling pathways. Since adipocytes express both gp130 and LIFR proteins and are responsive to other IL-6 family cytokines, we examined the effects of CT-1 on 3T3-L1 adipocytes. Our studies have shown that CT-1 administration results in a dose- and time-dependent activation and nuclear translocation of STAT1, -3, -5A, and -5B as well as ERK1 and -2. We also confirmed the ability of CT-1 to induce signaling in fat cells in vivo. Our studies revealed that neither CT-1 nor ciliary neurotrophic factor treatment affected adipocyte differentiation. However, acute CT-1 treatment caused an increase in SOCS-3 mRNA in adipocytes and a transient decrease in peroxisome proliferator-activated receptor gamma (PPARgamma) mRNA that was regulated by the binding of STAT1 to the PPARgamma2 promoter. The effects of CT-1 on SOCS-3 and PPARgamma mRNA were independent of MAPK activation. Chronic administration of CT-1 to 3T3-L1 adipocytes resulted in a decrease of both fatty acid synthase and insulin receptor substrate-1 protein expression yet did not effect the expression of a variety of other adipocyte proteins. Moreover, chronic CT-1 treatment resulted in the development of insulin resistance as judged by a decrease in insulin-stimulated glucose uptake. In summary, CT-1 is a potent regulator of signaling in adipocytes in vitro and in vivo, and our current efforts are focused on determining the role of this cardioprotective cytokine on adipocyte physiology.

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

    SciTech Connect

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

    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.

  13. Nitrite augments glucose uptake in adipocytes through the protein kinase A-dependent stimulation of mitochondrial fusion.

    PubMed

    Khoo, Nicholas K H; Mo, Li; Zharikov, Sergey; Kamga-Pride, Christelle; Quesnelle, Kelly; Golin-Bisello, Franca; Li, Lihua; Wang, Yinna; Shiva, Sruti

    2014-05-01

    Though it is well accepted that adipose tissue is central in the regulation of glycemic homeostasis, the molecular mechanisms governing adipocyte glucose uptake remain unclear. Recent studies demonstrate that mitochondrial dynamics (fission and fusion) regulate lipid accumulation and differentiation in adipocytes. However, the role of mitochondrial dynamics in glucose homeostasis has not been explored. The nitric oxide oxidation products nitrite and nitrate are endogenous signaling molecules and dietary constituents that have recently been shown to modulate glucose metabolism, prevent weight gain, and reverse the development of metabolic syndrome in mice. Although the mechanism of this protection is unclear, the mitochondrion is a known subcellular target for nitrite signaling. Thus, we hypothesize that nitrite modulates mitochondrial dynamics and function to regulate glucose uptake in adipocytes. Herein, we demonstrate that nitrite significantly increases glucose uptake in differentiated murine adipocytes through a mechanism dependent on mitochondrial fusion. Specifically, nitrite promotes mitochondrial fusion by increasing the profusion protein mitofusin 1 while concomitantly activating protein kinase A (PKA), which phosphorylates and inhibits the profission protein dynamin-related protein 1 (Drp1). Functionally, this signaling augments cellular respiration, fatty acid oxidation, mitochondrial oxidant production, and glucose uptake. Importantly, inhibition of PKA or Drp1 significantly attenuates nitrite-induced mitochondrial respiration and glucose uptake. These findings demonstrate that mitochondria play an essential metabolic role in adipocytes, show a novel role for both nitrite and mitochondrial fusion in regulating adipocyte glucose homeostasis, and have implications for the potential therapeutic use of nitrite and mitochondrial modulators in glycemic regulation.

  14. Nitrite augments glucose uptake in adipocytes through the Protein Kinase A-dependent stimulation of mitochondrial fusion

    PubMed Central

    Khoo, Nicholas K.H.; Mo, Li; Zharikov, Sergey; Kamga, Christelle; Quesnelle, Kelly; Golin-Bisello, Franca; Li, Lihua; Wang, Yinna; Shiva, Sruti

    2014-01-01

    Though it is well accepted that adipose tissue is central in the regulation of glycemic homeostasis, the molecular mechanisms governing adipocyte glucose uptake remain unclear. Recent studies demonstrate that mitochondrial dynamics (fission and fusion) regulate lipid accumulation and differentiation in adipocytes. However, the role of mitochondrial dynamics in glucose homeostasis has not been explored. The nitric oxide oxidation products nitrite and nitrate are endogenous signaling molecules and dietary constituents that have recently been shown to modulate glucose metabolism, prevent weight gain and reverse the development of metabolic syndrome in mice. While the mechanism of this protection is unclear, the mitochondrion is a known subcellular target for nitrite signaling. Thus, we hypothesize that nitrite modulates mitochondrial dynamics and function to regulate glucose uptake in adipocytes. Herein, we demonstrate that nitrite significantly increases glucose uptake in differentiated murine adipocytes through a mechanism dependent on mitochondrial fusion. Specifically, nitrite promotes mitochondrial fusion by increasing pro-fusion protein mitofusin 1 while concomitantly activating protein kinase A (PKA), which phosphorylates and inhibits the pro-fission protein, dynamin-related protein 1 (Drp1). Functionally, this signaling augments cellular respiration, fatty acid oxidation, mitochondrial oxidant production and glucose uptake. Importantly, inhibition of PKA or Drp1 significantly attenuates nitrite-induced mitochondrial respiration and glucose uptake. These findings demonstrate that mitochondria play an essential metabolic role in adipocytes, a novel role for both nitrite and mitochondrial fusion in regulating adipocyte glucose homeostasis and have implications for the potential therapeutic use of nitrite and mitochondrial modulators in glycemic regulation. PMID:24556414

  15. Role of lipid rafts in neuronal differentiation of dental pulp-derived stem cells.

    PubMed

    Mattei, Vincenzo; Santacroce, Costantino; Tasciotti, Vincenzo; Martellucci, Stefano; Santilli, Francesca; Manganelli, Valeria; Piccoli, Luca; Misasi, Roberta; Sorice, Maurizio; Garofalo, Tina

    2015-12-10

    Human dental pulp-derived stem cells (hDPSCs) are characterized by a typical fibroblast-like morphology. They express specific markers for mesenchymal stem cells and are capable of differentiation into osteoblasts, adipoblasts and neurons in vitro. Previous studies showed that gangliosides are involved in the induction of early neuronal differentiation of hDPSCs. This study was undertaken to investigate the role of lipid rafts in this process. Lipid rafts are signaling microdomains enriched in glycosphingolipids, cholesterol, tyrosine kinase receptors, mono- or heterotrimeric G proteins and GPI-anchored proteins. We preliminary showed that established cells expressed multipotent mesenchymal stromal-specific surface antigens. Then, we analyzed the distribution of lipid rafts, revealing plasma membrane microdomains with GM2 and EGF-R enrichment. Following stimulation with EGF/bFGF, neuronal differentiation was observed. To analyze the functional role of lipid rafts in EGF/bFGF-induced hDPSCs differentiation, cells were preincubated with lipid raft affecting agents, i.e. [D]-PDMP or methyl-β-cyclodextrin. These compounds significantly prevented neuronal-specific antigen expression, as well as Akt and ERK 1/2 phosphorylation, induced by EGF/bFGF, indicating that lipid raft integrity is essential for EGF/bFGF-induced hDPSCs differentiation. These results suggest that lipid rafts may represent specific chambers, where multimolecular signaling complexes, including lipids (gangliosides, cholesterol) and proteins (EGF-R), play a role in hDPSCs differentiation.

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

    SciTech Connect

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

    2014-08-08

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

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

    PubMed

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

    2017-04-01

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

  18. Cadmium modulates adipocyte functions in metallothionein-null mice

    SciTech Connect

    Kawakami, Takashige; Nishiyama, Kaori; Kadota, Yoshito; Sato, Masao; Inoue, Masahisa; Suzuki, Shinya

    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.

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

    PubMed

    Schweiger, Martina; Paar, Margret; Eder, Christina; Brandis, Janina; Moser, Elena; Gorkiewicz, Gregor; Grond, Susanne; Radner, Franz P W; Cerk, Ines; Cornaciu, Irina; Oberer, Monika; Kersten, Sander; Zechner, Rudolf; Zimmermann, Robert; Lass, Achim

    2012-11-01

    The hydrolysis of triglycerides in adipocytes, termed lipolysis, provides free fatty acids as energy fuel. Murine lipolysis largely depends on the activity of adipose triglyceride lipase (ATGL), which is regulated by two proteins annotated as comparative gene identification-58 (CGI-58) and G0/G1 switch gene-2 (G0S2). CGI-58 activates and G0S2 inhibits ATGL activity. In contrast to mice, the functional role of G0S2 in human adipocyte lipolysis is poorly characterized. Here we show that overexpression or silencing of G0S2 in human SGBS adipocytes decreases and increases lipolysis, respectively. Human G0S2 is upregulated during adipocyte differentiation and inhibits ATGL activity in a dose-dependent manner. Interestingly, C-terminally truncated ATGL mutants, which fail to localize to lipid droplets, translocate to the lipid droplet upon coexpression with G0S2, suggesting that G0S2 anchors ATGL to lipid droplets independent of ATGL's C-terminal lipid binding domain. Taken together, our results indicate that G0S2 also regulates human lipolysis by affecting enzyme activity and intracellular localization of ATGL. Increased lipolysis is known to contribute to the pathogenesis of insulin resistance, and G0S2 expression has been shown to be reduced in poorly controlled type 2 diabetic patients. Our data indicate that downregulation of G0S2 in adipose tissue could represent one of the underlying causes leading to increased lipolysis in the insulin-resistant state.

  20. Serine dipeptide lipids of Porphyromonas gingivalis inhibit osteoblast differentiation: Relationship to Toll-like receptor 2.

    PubMed

    Wang, Yu-Hsiung; Nemati, Reza; Anstadt, Emily; Liu, Yaling; Son, Young; Zhu, Qiang; Yao, Xudong; Clark, Robert B; Rowe, David W; Nichols, Frank C

    2015-12-01

    Porphyromonas gingivalis is a periodontal pathogen strongly associated with loss of attachment and supporting bone for teeth. We have previously shown that the total lipid extract of P. gingivalis inhibits osteoblast differentiation through engagement of Toll-like receptor 2 (TLR2) and that serine dipeptide lipids of P. gingivalis engage both mouse and human TLR2. The purpose of the present investigation was to determine whether these serine lipids inhibit osteoblast differentiation in vitro and in vivo and whether TLR2 engagement is involved. Osteoblasts were obtained from calvaria of wild type or TLR2 knockout mouse pups that also express the Col2.3GFP transgene. Two classes of serine dipeptide lipids, termed Lipid 654 and Lipid 430, were tested. Osteoblast differentiation was monitored by cell GFP fluorescence and osteoblast gene expression and osteoblast function was monitored as von Kossa stained mineral deposits. Osteoblast differentiation and function were evaluated in calvarial cell cultures maintained for 21 days. Lipid 654 significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation and this inhibition was dependent on TLR2 engagement. Lipid 430 also significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation but these effects were only partially attributed to engagement of TLR2. More importantly, Lipid 430 stimulated TNF-α and RANKL gene expression in wild type cells but not in TLR2 knockout cells. Finally, osteoblast cultures were observed to hydrolyze Lipid 654 to Lipid 430 and this likely occurs through elevated PLA2 activity in the cultured cells. In conclusion, our results show that serine dipeptide lipids of P. gingivalis inhibit osteoblast differentiation and function at least in part through engagement of TLR2. The Lipid 430 serine class also increased the expression of genes that could increase osteoclast activity. We conclude that Lipid 654 and Lipid 430 have the potential

  1. Metabolic heterogeneity of activated beige/brite adipocytes in inguinal adipose tissue

    PubMed Central

    Lee, Yun-Hee; Kim, Sang-Nam; Kwon, Hyun-Jung; Granneman, James G.

    2017-01-01

    Sustained β3 adrenergic receptor (ADRB3) activation simultaneously upregulates fatty acid synthesis and oxidation in mouse brown, beige, and white adipose tissues; however, the cellular basis of this dual regulation is not known. Treatment of mice with the ADRB3 agonist CL316,243 (CL) increased expression of fatty acid synthase (FASN) and medium chain acyl-CoA dehydrogenase (MCAD) protein within the same cells in classic brown and white adipose tissues. Surprisingly, in inguinal adipose tissue, CL-upregulated FASN and MCAD in distinct cell populations: high MCAD expression occurred in multilocular adipocytes that co-expressed UCP1+, whereas high FASN expression occurred in paucilocular adipocytes lacking detectable UCP1. Genetic tracing with UCP1-cre, however, indicated nearly half of adipocytes with a history of UCP1 expression expressed high levels of FASN without current expression of UCP1. Global transcriptomic analysis of FACS-isolated adipocytes confirmed the presence of distinct anabolic and catabolic phenotypes, and identified differential expression of transcriptional pathways known to regulate lipid synthesis and oxidation. Surprisingly, paternally-expressed genes of the non-classical gene imprinted network were strikingly enriched in anabolic phenotypes, suggesting possible involvement in maintaining the balance of metabolic phenotypes. The results indicate that metabolic heterogeneity is a distinct property of activated beige/brite adipocytes that might be under epigenetic control. PMID:28045125

  2. Dehydroepiandrosterone down-regulates the expression of peroxisome proliferator-activated receptor gamma in adipocytes.

    PubMed

    Kajita, Kazuo; Ishizuka, Tatsuo; Mune, Tomoatsu; Miura, Atsushi; Ishizawa, Masayoshi; Kanoh, Yoshinori; Kawai, Yasunori; Natsume, Yoshiyuki; Yasuda, Keigo

    2003-01-01

    Dehydroepiandrosterone (DHEA) is expected to have a weight-reducing effect. In this study, we evaluated the effect of DHEA on genetically obese Otsuka Long Evans Fatty rats (OLETF) compared with Long-Evans Tokushima rats (LETO) as control. Feeding with 0.4% DHEA-containing food for 2 wk reduced the weight of sc, epididymal, and perirenal adipose tissue in association with decreased plasma leptin levels in OLETF. Adipose tissue from OLETF showed increased expression of peroxisome proliferator-activated receptor gamma (PPARgamma) protein, which was prevented by DHEA treatment. Further, we examined the effect of DHEA on PPARgamma in primary cultured adipocytes and monolayer adipocytes differentiated from rat preadipocytes. PPARgamma protein level was decreased in a time- and concentration-dependent manner, and DHEA significantly reduced mRNA levels of PPARgamma, adipocyte lipid-binding protein, and sterol regulatory element-binding protein, but not CCAAT/enhancer binding protein alpha. DHEA-sulfate also reduced the PPARgamma protein, but dexamethasone, testosterone, or androstenedione did not alter its expression. In addition, treatment with DHEA for 5 d reduced the triglyceride content in monolayer adipocytes. These results suggest that DHEA down-regulates adiposity through the reduction of PPARgamma in adipocytes.

  3. Mitochondria in White, Brown, and Beige Adipocytes

    PubMed Central

    Cedikova, Miroslava; Kripnerová, Michaela; Dvorakova, Jana; Pitule, Pavel; Grundmanova, Martina; Babuska, Vaclav; Mullerova, Dana; Kuncova, Jitka

    2016-01-01

    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. PMID:27073398

  4. Rosiglitazone drives cavin-2/SDPR expression in adipocytes in a CEBPα-dependent manner

    PubMed Central

    Wasserstrom, Sebastian; Säll, Johanna; Göransson, Olga; Swärd, Karl; Stenkula, Karin G.

    2017-01-01

    Caveolae are abundant adipocyte surface domains involved in insulin signaling, membrane trafficking and lipid homeostasis. Transcriptional control mechanisms for caveolins and cavins, the building blocks of caveolae, are thus arguably important for adipocyte biology and studies in this area may give insight into insulin resistance and diabetes. Here we addressed the hypothesis that one of the less characterized caveolar components, cavin-2 (SDPR), is controlled by CCAAT/Enhancer Binding Protein (CEBPα) and Peroxisome Proliferator-Activated Receptor Gamma (PPARG). Using human mRNA expression data we found that SDPR correlated with PPARG in several tissues. This was also observed during differentiation of 3T3-L1 fibroblasts into adipocytes. Treatment of 3T3-L1-derived adipocytes with the PPARγ-activator Rosiglitazone increased SDPR and CEBPα expression at both the mRNA and protein levels. Silencing of CEBPα antagonized these effects. Further, adenoviral expression of PPARγ/CEBPα or Rosiglitazone-treatment increased SDPR expression in primary rat adipocytes. The myocardin family coactivator MKL1 was recently shown to regulate SDPR expression in human coronary artery smooth muscle cells. However, we found that actin depolymerization, known to inhibit MKL1 and MKL2, was without effect on SDPR mRNA levels in adipocytes, even though overexpression of MKL1 and MKL2 had the capacity to increase caveolins and cavins and to repress PPARγ/CEBPα. Altogether, this work demonstrates that CEBPα expression and PPARγ-activity promote SDPR transcription and further supports the emerging notion that PPARγ/CEBPα and MKL1/MKL2 are antagonistic in adipocytes. PMID:28278164

  5. The glucose sensor ChREBP links de-novo lipogenesis to PPARgamma activity and adipocyte differentiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduced de-novo lipogenesis DNL)in adipose tissue, often observed in obese individuals, is thought to contribute to insulin resistance. Besides trapping excess glucose and providing for triglycerides and energy storage, endogenously synthesized lipids can function as potent signaling molecules. Inde...

  6. 18O-Tracer Metabolomics Reveals Protein Turnover and CDP-Choline Cycle Activity in Differentiating 3T3-L1 Pre-Adipocytes

    PubMed Central

    Kirkwood, Jay S.; Miranda, Cristobal L.; Bobe, Gerd; Maier, Claudia S.; Stevens, Jan F.

    2016-01-01

    The differentiation of precursor cells into mature adipocytes (adipogenesis) has been an area of increased focus, spurred by a rise in obesity rates. Though our understanding of adipogenesis and its regulation at the cellular level is growing, many questions remain, especially regarding the regulation of the metabolome. The 3T3-L1 cell line is the most well characterized cellular model of adipogenesis. Using a time course metabolomics approach, we show that the 3T3-L1 preadipocyte metabolome is greatly altered during the first 48 hours of differentiation, where cells go through about two rounds of cell division, a process known as mitotic clonal expansion. Short-chain peptides were among several small molecules that were increased during mitotic clonal expansion. Additional indicators of protein turnover were also increased, including bilirubin, a degradation product of heme-containing proteins, and 3-methylhistidine, a post-translationally modified amino acid that is not reutilized for protein synthesis. To study the origin of the peptides, we treated differentiating preadipocytes with 18O labeled water and found that 18O was incorporated into the short chain peptides, confirming them, at least in part, as products of hydrolysis. Inhibitors of the proteasome or matrix metalloproteinases affected the peptide levels during differentiation, but inhibitors of autophagy or peptidases did not. 18O was also incorporated into several choline metabolites including cytidine 5'-diphosphocholine (CDP-choline), glycerophosphocholine, and several phosphatidylcholine species, indicative of phosphatidylcholine synthesis/degradation and of flux through the CDP-choline cycle, a hallmark of proliferating cells. 18O-Tracer metabolomics further showed metabolic labeling of glutamate, suggestive of glutaminolysis, also characteristic of proliferating cells. Together, these results highlight the utility of 18O isotope labeling in combination with metabolomics to uncover changes in

  7. Differential proteomic and oxidative profiles unveil dysfunctional protein import to adipocyte mitochondria in obesity-associated aging and diabetes.

    PubMed

    Gómez-Serrano, María; Camafeita, Emilio; López, Juan A; Rubio, Miguel A; Bretón, Irene; García-Consuegra, Inés; García-Santos, Eva; Lago, Jesús; Sánchez-Pernaute, Andrés; Torres, Antonio; Vázquez, Jesús; Peral, Belén

    2017-04-01

    Human age-related diseases, including obesity and type 2 diabetes (T2DM), have long been associated to mitochondrial dysfunction; however, the role for adipose tissue mitochondria in these conditions remains unknown. We have tackled the impact of aging and T2DM on adipocyte mitochondria from obese patients by quantitating not only the corresponding abundance changes of proteins, but also the redox alterations undergone by Cys residues thereof. For that, we have resorted to a high-throughput proteomic approach based on isobaric labeling, liquid chromatography and mass spectrometry. The alterations undergone by the mitochondrial proteome revealed aging- and T2DM-specific hallmarks. Thus, while a global decrease of oxidative phosphorylation (OXPHOS) subunits was found in aging, the diabetic patients exhibited a reduction of specific OXPHOS complexes as well as an up-regulation of the anti-oxidant response. Under both conditions, evidence is shown for the first time of a link between increased thiol protein oxidation and decreased protein abundance in adipose tissue mitochondria. This association was stronger in T2DM, where OXPHOS mitochondrial- vs. nuclear-encoded protein modules were found altered, suggesting impaired mitochondrial protein translocation and complex assembly. The marked down-regulation of OXPHOS oxidized proteins and the alteration of oxidized Cys residues related to protein import through the redox-active MIA (Mitochondrial Intermembrane space Assembly) pathway support that defects in protein translocation to the mitochondria may be an important underlying mechanism for mitochondrial dysfunction in T2DM and physiological aging. The present draft of redox targets together with the quantification of protein and oxidative changes may help to better understand the role of oxidative stress in both a physiological process like aging and a pathological condition like T2DM.

  8. Hyperglycemia and advanced glycosylation end products suppress adipocyte apoE expression: implications for adipocyte triglyceride metabolism.

    PubMed

    Espiritu, Doris Joy; Huang, Zhi Hua; Zhao, Yong; Mazzone, Theodore

    2010-10-01

    Endogenous adipocyte apolipoprotein E (apoE) plays an important role in adipocyte lipoprotein metabolism and lipid flux. A potential role for hyperglycemia in regulating adipocyte apoE expression and triglyceride metabolism was examined. Exposure of adipocytes to high glucose or advanced glycosylation end product-BSA significantly suppressed apoE mRNA and protein levels. This suppression was significantly attenuated by antioxidants or inhibitors of the NF-κB transcription pathway. Hyperglycemia in vivo led to adipose tissue oxidant stress and significant reduction in adipose tissue and adipocyte apoE mRNA level. Incubation with antioxidant in organ culture completely reversed this suppression. Hyperglycemia also reduced adipocyte triglyceride synthesis, and this could be completely reversed by adenoviral-mediated increases in apoE. To more specifically evaluate an in vivo role for adipocyte apoE expression on organismal triglyceride distribution in vivo, WT or apoE knockout (EKO) adipose tissue was transplanted in EKO recipient mice. After 12 wk, WT adipocytes transplanted in EKO mice accumulated more triglyceride compared with transplanted EKO adipocytes. In addition, EKO recipients of WT adipose tissue had reduced hepatic triglyceride content compared with EKO recipients transplanted with EKO adipose tissue. Our results demonstrate that hyperglycemia and advanced glycosylation end products suppress the expression of adipocyte apoE in vitro and in vivo and thereby reduce adipocyte triglyceride synthesis. In vivo results using adipose tissue transplantation suggest that reduction of adipocyte apoE, and subsequent reduction of adipocyte triglyceride accumulation, could influence lipid accumulation in nonadipose tissue.

  9. The demands of lactation promote differential regulation of lipid stores in fasting elephant seals.

    PubMed

    Fowler, Melinda A; Debier, Cathy; Champagne, Cory D; Crocker, Daniel E; Costa, Daniel P

    2016-01-01

    Fasting animals must ration stored reserves appropriately for metabolic demands. Animals that experience fasting concomitant with other metabolically demanding activities are presented with conflicting demands of energy conservation and expenditure. Our objective was to understand how fasting northern elephant seals regulate the mobilization of lipid reserves and subsequently milk lipid content during lactation. We sampled 36 females early and 39 at the end of lactation. To determine the separate influences of lactation from fasting, we also sampled fasting but non-lactating females early and late (8 and 6 seals, respectively) in their molting fasting period. Mass and adiposity were measured, as well as circulating non-esterified fatty acid (NEFA), triacylglycerol (TAG), cortisol, insulin and growth hormone levels. Milk was collected from lactating females. Milk lipid content increased from 31% in early to 51% in late lactation. In lactating females plasma NEFA was positively related to cortisol and negatively related to insulin, but in molting seals, only variation in cortisol was related to NEFA. Milk lipid content varied with mass, adiposity, NEFA, TAG, cortisol and insulin. Surprisingly, growth hormone concentration was not related to lipid metabolites or milk lipid. Suppression of insulin release appears to be the differential regulator of lipolysis in lactating versus molting seals, facilitating mobilization of stored lipids and maintenance of high NEFA concentrations for milk synthesis. Milk lipid was strongly impacted by the supply of substrate to the mammary gland, indicating regulation at the level of mobilization of lipid reserves.

  10. Genistein-mediated inhibition of mammary stromal adipocyte differentiation limits expansion of mammary stem/progenitor cells by paracrine signaling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary adiposity may contribute to breast cancer development and progression by releasing cytokines and other inflammatory mediators that promote mammary epithelial proliferation. We evaluated the effects of soy isoflavone genistein (GEN) on the adipogenic differentiation of a SV40-immortalized mou...

  11. Regulation of adipocyte lipid homeostasis by genistein alters mammary epithelial cell differentiation: a paracrine mechanism for mammary tumor protection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Epidemiological and animal studies have shown a negative correlation between breast cancer incidence and intake of soy rich foods. Our laboratory has studied soy protein isolate (SPI), the primary component of soy infant formula, as a paradigm to evaluate diet as a risk factor in mammary cancer. We ...

  12. Vascular endothelial cell membranes differentiate between stretch and shear stress through transitions in their lipid phases.

    PubMed

    Yamamoto, Kimiko; Ando, Joji

    2015-10-01

    Vascular endothelial cells (ECs) respond to the hemodynamic forces stretch and shear stress by altering their morphology, functions, and gene expression. However, how they sense and differentiate between these two forces has remained unknown. Here we report that the plasma membrane itself differentiates between stretch and shear stress by undergoing transitions in its lipid phases. Uniaxial stretching and hypotonic swelling increased the lipid order of human pulmonary artery EC plasma membranes, thereby causing a transition from the liquid-disordered phase to the liquid-ordered phase in some areas, along with a decrease in membrane fluidity. In contrast, shear stress decreased the membrane lipid order and increased membrane fluidity. A similar increase in lipid order occurred when the artificial lipid bilayer membranes of giant unilamellar vesicles were stretched by hypotonic swelling, indicating that this is a physical phenomenon. The cholesterol content of EC plasma membranes significantly increased in response to stretch but clearly decreased in response to shear stress. Blocking these changes in the membrane lipid order by depleting membrane cholesterol with methyl-β-cyclodextrin or by adding cholesterol resulted in a marked inhibition of the EC response specific to stretch and shear stress, i.e., phosphorylation of PDGF receptors and phosphorylation of VEGF receptors, respectively. These findings indicate that EC plasma membranes differently respond to stretch and shear stress by changing their lipid order, fluidity, and cholesterol content in opposite directions and that these changes in membrane physical properties are involved in the mechanotransduction that activates membrane receptors specific to each force.

  13. Interferon inhibits the conversion of 3T3-L1 mouse fibroblasts into adipocytes.

    PubMed Central

    Keay, S; Grossberg, S E

    1980-01-01

    Confluent Swiss mouse 3T3-L1 fibroblasts slowly differentiate functionally and morphologically into adipocytes, a conversion hastened by insulin. The cells are sensitive (although less than L929 cells) to the antiviral action of mouse fibroblast interferons but not to interferons from heterologous species (human and chicken). Cultures stimulated with insulin in the presence of partially purified or electrophoretically pure mouse interferons have a much lower percentage of cells accumulating lipid than do insulin-treated control cultures. Interferon-treated cell cultures also contain much less triglyceride, cholesterol, and cholesterol esters than do replicate control cultures stimulated by insulin to differentiate. Increased de novo lipid biosynthesis that occurs during differentiation is inhibited, as determined by incorporation of [14C]acetate into lipids extractable by the Folch method. This incorporation is a sensitive bioassay of the antidifferentiation effect of interferon; less than 1 antiviral unit is inhibitory. Variously inactivated or mock interferon preparations as well as interferons from several heterologous species fail to inhibit 3T3-L1 adipocyte conversion. Interferon is inhibitory even when applied as long as 3 days after insulin stimulation. The effect of interferon does not appear to depend upon its competition with insulin for cell surface receptors. Because interferon can alter the program of events involved in conversion of 3T3-L1 fibroblasts into adipose cells, it may be able to affect the regulation of eukaryotic cell differentiation. Images PMID:6159626

  14. Differential anti-lipid peroxidative activity of melatonin

    NASA Astrophysics Data System (ADS)

    Kawanishi, Shinya; Sakurai, Hiromu

    2002-01-01

    Scavenging activities of melatonin, which is a pineal secretory product and functions in circadian biology, and its related compounds against reactive oxygen species such as superoxide anion radical, hydrogen peroxide, hydroxyl radical and singlet oxygen as well as organic peroxide radical (t-BuOO•) were evaluated chemically by using electron spin resonance-spin trap and chemiluminescence methods. Antioxidative activity of the compounds was estimated by IC50 value (µM), 50% inhibiting concentration of a compound against reactive oxygen species formed in each system, and the second-order rate constants ( k 2) for the reactions of the compounds and superoxide anion radical or hydroxyl radical. Because melatonin has exhibited the highest scavenging activity against t-BuOO•, the biochemical anti-lipid peroxide radical scavenging activities of melatonin were examined. We found that melatonin exhibits higher anti-lipid peroxidative activity in the rat brain microsomes than in the rat liver microsomal and liposomal systems, suggesting that melatonin may function as a treatment for reactive oxygen species-related diseases of the brain.

  15. Adipocytes as immune cells: differential expression of TWEAK, BAFF, and APRIL and their receptors (Fn14, BAFF-R, TACI, and BCMA) at different stages of normal and pathological adipose tissue development.

    PubMed

    Alexaki, Vassilia-Ismini; Notas, George; Pelekanou, Vassiliki; Kampa, Marilena; Valkanou, Maria; Theodoropoulos, Panayiotis; Stathopoulos, Efstathios N; Tsapis, Andreas; Castanas, Elias

    2009-11-01

    Adipose tissue represents a rich source of multipotent stem cells. Mesenchymal cells, isolated from this source, can differentiate to other cell types in vitro and therefore can be used for a number of regenerative therapies. Our view of adipose tissue has recently changed, establishing adipocytes as new members of the immune system, as they produce a number of proinflammatory cytokines (such as IL-6 and TNFalpha and chemokines, in addition to adipokines (leptin, adiponectin, resistin) and molecules associated with the innate immune system. In this paper, we report the differential expression of TNF-superfamily members B cell activating factor of the TNF Family (BAFF), a proliferation inducing ligand (APRIL), and TNF-like weak inducer of apoptosis (TWEAK) in immature-appearing and mature adipocytes and in benign and malignant adipose tissue-derived tumors. These ligands act through their cognitive receptors, BAFF receptor, transmembrane activator and calcium signal-modulating cyclophilic ligand (TACI), B cell maturation Ag (BCMA), and fibroblast growth factor-inducible 14 (Fn14), which are also expressed in these cells. We further report the existence of functional BCMA, TACI, and Fn14 receptors and their ligands BAFF, APRIL, and TWEAK on adipose tissue-derived mesenchymal cells, their interaction modifying the rate of adipogenesis. Our data integrate BAFF, APRIL, and TWEAK and their receptors BCMA, TACI, and Fn14 as novel potential mediators of adipogenesis, in addition to their specific role in immunity, and define immature and mature adipocytes as source of immune mediators.

  16. Dynamics of Adipocyte Turnover in Humans

    SciTech Connect

    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.

  17. Suppression of Very Early Stage Of Adipogenesis by Baicalein, a Plant-Derived Flavonoid through Reduced Akt-C/EBPα-GLUT4 Signaling-Mediated Glucose Uptake in 3T3-L1 Adipocytes

    PubMed Central

    2016-01-01

    Baicalein has been used as a Chinese medicine, and is an abundant plant flavonoid present in fruits and vegetables. Here, we examined the effects of baicalein in adipogenesis and investigated its molecular mechanism in adipocytes. Baicalein lowered the intracellular lipid accumulation and decreased the transcription levels of the adipocyte-specific genes in mouse 3T3-L1 adipocytes. Glucose uptake mediated by glucose transporter 4 (GLUT4) was reduced, causing down-regulation of the intracellular lipid accumulation. These reductions were also observed even when baicalein was added in only early stage of adipogenesis (0–2 days) of 6-day-adipogenesis. Chromatin immunoprecipitation assay showed that baicalein decreased the binding level of C/EBPα protein to the promoter region of the GLUT4 gene. Phosphorylation of Akt at 1 h after the initiation of adipogenesis was inhibited by the treatment with baicalein. Inhibition during only the first 1.5 h after the initiation of adipogenesis by baicalein or an Akt inhibitor was enough to decrease the lipid contents in the cells undergoing adipocyte differentiation for 6 days. These results indicate that baicalein decreased the intracellular lipid accumulation by down-regulation of glucose uptake via repression of Akt-C/EBPα-GLUT4 signaling in the very early stage of adipogenesis of 3T3-L1 adipocytes. PMID:27669565

  18. Cocoa and Whey Protein Differentially Affect Markers of Lipid and Glucose Metabolism and Satiety.

    PubMed

    Campbell, Caroline L; Foegeding, E Allen; Harris, G Keith

    2016-03-01

    Food formulation with bioactive ingredients is a potential strategy to promote satiety and weight management. Whey proteins are high in leucine and are shown to decrease hunger ratings and increase satiety hormone levels; cocoa polyphenolics moderate glucose levels and slow digestion. This study examined the effects of cocoa and whey proteins on lipid and glucose metabolism and satiety in vitro and in a clinical trial. In vitro, 3T3-L1 preadipocytes were treated with 0.5-100 μg/mL cocoa polyphenolic extract (CPE) and/or 1-15 mM leucine (Leu) and assayed for lipid accumulation and leptin production. In vivo, a 6-week clinical trial consisted of nine panelists (age: 22.6 ± 1.7; BMI: 22.3 ± 2.1) consuming chocolate-protein beverages once per week, including placebo, whey protein isolate (WPI), low polyphenolic cocoa (LP), high polyphenolic cocoa (HP), LP-WPI, and HP-WPI. Measurements included blood glucose and adiponectin levels, and hunger ratings at baseline and 0.5-4.0 h following beverage consumption. At levels of 50 and 100 μg/mL, CPE significantly inhibited preadipocyte lipid accumulation by 35% and 50%, respectively, and by 22% and 36% when combined with 15 mM Leu. Leu treatment increased adipocyte leptin production by 26-37%. In the clinical trial, all beverages significantly moderated blood glucose levels 30 min postconsumption. WPI beverages elicited lowest peak glucose levels and HP levels were significantly lower than LP. The WPI and HP beverage treatments significantly increased adiponectin levels, but elicited no significant changes in hunger ratings. These trends suggest that combinations of WPI and cocoa polyphenols may improve markers of metabolic syndrome and satiety.

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

    SciTech Connect

    Park, Yu-Kyoung; Lee, Tae-Yoon; Choi, Jong-Soon; Hong, Victor Sukbong; Lee, Jinho; Park, Jong-Wook; Jang, Byeong-Churl

    2014-10-03

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

  20. Early B cell factor 1 regulates adipocyte morphology and lipolysis in white adipose tissue.

    PubMed

    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; Arner, Peter

    2014-06-03

    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 genes controlling lipolysis and adipocyte morphology/differentiation, and in both humans and murine models, reduced EBF1 levels associated with increased lipolysis and adipose hypertrophy. Although EBF1 did not affect adipose inflammation, TNFα reduced EBF1 gene expression. High-fat diet intervention in Ebf1(+/-) mice resulted in more pronounced WAT hypertrophy and attenuated insulin sensitivity compared with wild-type littermate controls. We conclude that EBF1 is an important regulator of adipose morphology and fat cell lipolysis and may constitute a link between WAT inflammation, altered lipid metabolism, adipose hypertrophy, and insulin resistance.

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

    PubMed Central

    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.; Arner, Peter

    2014-01-01

    Summary 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 genes controlling lipolysis and adipocyte morphology/differentiation and in both humans and murine models, reduced EBF1 levels associated with increased lipolysis and adipose hypertrophy. Although EBF1 did not affect adipose inflammation, TNFα reduced EBF1 gene expression. High fat diet-intervention in Ebf1+/− mice resulted in more pronounced WAT hypertrophy and attenuated insulin sensitivity compared with wild-type littermate controls. We conclude that EBF1 is an important regulator of adipose morphology and fat cell lipolysis and may constitute a link between WAT inflammation, altered lipid metabolism, adipose hypertrophy and insulin resistance. PMID:24856929

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

    PubMed

    Bae, Jiyoung; Chen, Jiangang; Zhao, Ling

    2015-06-01

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

  3. Feed-forward inhibition of androgen receptor activity by glucocorticoid action in human adipocytes.

    PubMed

    Hartig, Sean M; He, Bin; Newberg, Justin Y; Ochsner, Scott A; Loose, David S; Lanz, Rainer B; McKenna, Neil J; Buehrer, Benjamin M; McGuire, Sean E; Marcelli, Marco; Mancini, Michael A

    2012-09-21

    We compared transcriptomes of terminally differentiated mouse 3T3-L1 and human adipocytes to identify cell-specific differences. Gene expression and high content analysis (HCA) data identified the androgen receptor (AR) as both expressed and functional, exclusively during early human adipocyte differentiation. The AR agonist dihydrotestosterone (DHT) inhibited human adipocyte maturation by downregulation of adipocyte marker genes, but not in 3T3-L1. It is interesting that AR induction corresponded with dexamethasone activation of the glucocorticoid receptor (GR); however, when exposed to the differentiation cocktail required for adipocyte maturation, AR adopted an antagonist conformation and was transcriptionally repressed. To further explore effectors within the cocktail, we applied an image-based support vector machine (SVM) classification scheme to show that adipocyte differentiation components inhibit AR action. The results demonstrate human adipocyte differentiation, via GR activation, upregulates AR but also inhibits AR transcriptional activity.

  4. Bavachin from Psoralea corylifolia Improves Insulin-Dependent Glucose Uptake through Insulin Signaling and AMPK Activation in 3T3-L1 Adipocytes.

    PubMed

    Lee, Hyejin; Li, Hua; Noh, Minsoo; Ryu, Jae-Ha

    2016-04-08

    The fruit of Psoralea corylifolia L. (Fabaceae) (PC), known as "Bo-Gol-Zhee" in Korea has been used as traditional medicine. Ethanol and aqueous extracts of PC have an anti-hyperglycemic effect by increasing plasma insulin levels and decreasing blood glucose and total plasma cholesterol levels in type 2 diabetic rats. In this study, we purified six compounds from PC and investigated their anti-diabetic effect. Among the purified compounds, bavachin most potently accumulated lipids during adipocyte differentiation. Intracellular lipid accumulation was measured by Oil Red-O (ORO) cell staining to investigate the effect of compounds on adipogenesis. Consistently, bavachin activated gene expression of adipogenic transcriptional factors, proliferator-activated receptorγ (PPARγ) and CCAAT/enhancer binding protein-α (C/EBPα). Bavachin also increased adiponectin expression and secretion in adipocytes. Moreover, bavachin increased insulin-induced glucose uptake by differentiated adipocytes and myoblasts. In differentiated adipocytes, we found that bavachin enhanced glucose uptake via glucose transporter 4 (GLUT4) translocation by activating the Akt and 5'AMP-activated protein kinase (AMPK) pathway in the presence or absence of insulin. These results suggest that bavachin from Psoralea corylifolia might have therapeutic potential for type 2 diabetes by activating insulin signaling pathways.

  5. Bavachin from Psoralea corylifolia Improves Insulin-Dependent Glucose Uptake through Insulin Signaling and AMPK Activation in 3T3-L1 Adipocytes

    PubMed Central

    Lee, Hyejin; Li, Hua; Noh, Minsoo; Ryu, Jae-Ha

    2016-01-01

    The fruit of Psoralea corylifolia L. (Fabaceae) (PC), known as “Bo-Gol-Zhee” in Korea has been used as traditional medicine. Ethanol and aqueous extracts of PC have an anti-hyperglycemic effect by increasing plasma insulin levels and decreasing blood glucose and total plasma cholesterol levels in type 2 diabetic rats. In this study, we purified six compounds from PC and investigated their anti-diabetic effect. Among the purified compounds, bavachin most potently accumulated lipids during adipocyte differentiation. Intracellular lipid accumulation was measured by Oil Red-O (ORO) cell staining to investigate the effect of compounds on adipogenesis. Consistently, bavachin activated gene expression of adipogenic transcriptional factors, proliferator-activated receptorγ (PPARγ) and CCAAT/enhancer binding protein-α (C/EBPα). Bavachin also increased adiponectin expression and secretion in adipocytes. Moreover, bavachin increased insulin-induced glucose uptake by differentiated adipocytes and myoblasts. In differentiated adipocytes, we found that bavachin enhanced glucose uptake via glucose transporter 4 (GLUT4) translocation by activating the Akt and 5′AMP-activated protein kinase (AMPK) pathway in the presence or absence of insulin. These results suggest that bavachin from Psoralea corylifolia might have therapeutic potential for type 2 diabetes by activating insulin signaling pathways. PMID:27070585

  6. RPL13A and EEF1A1 Are Suitable Reference Genes for qPCR during Adipocyte Differentiation of Vascular Stromal Cells from Patients with Different BMI and HOMA-IR

    PubMed Central

    Gentile, Adriana-Mariel; Lhamyani, Said; Coín-Aragüez, Leticia; Oliva-Olivera, Wilfredo; Zayed, Hatem; Vega-Rioja, Antonio; Monteseirin, Javier; Romero-Zerbo, Silvana-Yanina; Tinahones, Francisco-José; Bermúdez-Silva, Francisco-Javier; El Bekay, Rajaa

    2016-01-01

    Real-time or quantitative PCR (qPCR) is a useful technique that requires reliable reference genes for data normalization in gene expression analysis. Adipogenesis is among the biological processes suitable for this technique. The selection of adequate reference genes is essential for qPCR gene expression analysis of human Vascular Stromal Cells (hVSCs) during their differentiation into adipocytes. To the best of our knowledge, there are no studies validating reference genes for the analyses of visceral and subcutaneous adipose tissue hVSCs from subjects with different Body Mass Index (BMI) and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index. The present study was undertaken to analyze this question. We first analyzed the stability of expression of five potential reference genes: CYC, GAPDH, RPL13A, EEF1A1, and 18S ribosomal RNA, during in vitro adipogenic differentiation, in samples from these types of patients. The expression of RPL13A and EEF1A1 was not affected by differentiation, thus being these genes the most stable candidates, while CYC, GAPDH, and 18S were not suitable for this sort of analysis. This work highlights that RPL13A and EEF1A1 are good candidates as reference genes for qPCR analysis of hVSCs differentiation into adipocytes from subjects with different BMI and HOMA-IR. PMID:27304673

  7. Functional Human Beige Adipocytes from Induced Pluripotent Stem Cells.

    PubMed

    Guénantin, Anne-Claire; Briand, Nolwenn; Capel, Emilie; Dumont, Florent; Morichon, Romain; Provost, Claire; Stillitano, Francesca; Jeziorowska, Dorota; Siffroi, Jean-Pierre; Hajjar, Roger J; Fève, Bruno; Hulot, Jean-Sébastien; Collas, Philippe; Capeau, Jacqueline; Vigouroux, Corinne

    2017-03-07

    Activation of thermogenic beige adipocytes has recently emerged as a promising therapeutic target in obesity and diabetes. Relevant human models for beige adipocyte differentiation are essential to implement such therapeutic strategies. We report a straightforward and efficient protocol to generate functional human beige adipocytes from induced pluripotent stem cells (hiPSCs). Without overexpression of exogenous adipogenic genes, our method recapitulates an adipogenic developmental pathway through successive mesodermal and adipogenic progenitor stages. hiPSC-derived adipocytes are insulin-sensitive and display beige-specific markers and functional properties including upregulation of thermogenic genes, increased mitochondrial content and increased oxygen consumption upon activation with cAMP analogues. Engraftment of hiPSC-derived adipocytes in mice produces well-organized and vascularized adipose tissue, capable of β-adrenergic-responsive glucose uptake. Our model of human beige adipocyte development provides a new and scalable tool for disease modeling and therapeutic screening.

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

    PubMed Central

    Seo, Chang-Seob; Shin, Hyeun-Kyoo

    2015-01-01

    Background. Oyaksungi-san (OYSGS) is a herbal formula that has been used for treating cardiovascular diseases in traditional Asian medicine. Here, we investigated the antiadipogenic effect of OYSGS extract in 3T3-L1 adipose cells. Methods. 3T3-L1 preadipocytes were differentiated into adipocytes with or without OYSGS. After differentiation, we measured Oil Red O staining, glycerol-3-phosphate dehydrogenase (GPDH) activity, leptin production, mRNA, and protein levels of adipogenesis-related factors. Results. OYSGS extract dramatically inhibited intracellular lipid accumulation in the differentiated adipocytes. It also significantly suppressed the (GPDH) activity, triglyceride (TG) content, and leptin production by reducing the expression of adipogenesis-related genes including lipoprotein lipase, fatty acid binding protein 4, CCAAT/enhancer-binding protein-alpha (C/EBP-α), and peroxisome proliferator-activated receptor gamma (PPAR-γ). Furthermore, OYSGS clearly enhanced phosphorylation of AMP-activated protein kinase (AMPK) as well as its substrate acetyl CoA (ACC) carboxylase. Conclusions. Our results demonstrate that OYSGS negatively controls TG accumulation in 3T3-L1 adipocytes. We suggest antiadipogenic activity of OYSGS and its potential benefit in preventing obesity. PMID:25802547

  9. Ginkgolide C Suppresses Adipogenesis in 3T3-L1 Adipocytes via the AMPK Signaling Pathway

    PubMed Central

    Liou, Chian-Jiun; Lai, Xuan-Yu; Chen, Ya-Ling; Wang, Chia-Ling; Wei, Ciao-Han; Huang, Wen-Chung

    2015-01-01

    Ginkgolide C, isolated from Ginkgo biloba leaves, is a flavone reported to have multiple biological functions, from decreased platelet aggregation to ameliorating Alzheimer disease. The study aim was to evaluate the antiadipogenic effect of ginkgolide C in 3T3-L1 adipocytes. Ginkgolide C was used to treat differentiated 3T3-L1 cells. Cell supernatant was collected to assay glycerol release, and cells were lysed to measure protein and gene expression related to adipogenesis and lipolysis by western blot and real-time PCR, respectively. Ginkgolide C significantly suppressed lipid accumulation in differentiated adipocytes. It also decreased adipogenesis-related transcription factor expression, including peroxisome proliferator-activated receptor and CCAAT/enhancer-binding protein. Furthermore, ginkgolide C enhanced adipose triglyceride lipase and hormone-sensitive lipase production for lipolysis and increased phosphorylation of AMP-activated protein kinase (AMPK), resulting in decreased activity of acetyl-CoA carboxylase for fatty acid synthesis. In coculture with an AMPK inhibitor (compound C), ginkgolide C also improved activation of sirtuin 1 and phosphorylation of AMPK in differentiated 3T3-L1 cells. The results suggest that ginkgolide C is an effective flavone for increasing lipolysis and inhibiting adipogenesis in adipocytes through the activated AMPK pathway. PMID:26413119

  10. Lipid deregulation in UV irradiated skin cells: Role of 25-hydroxycholesterol in keratinocyte differentiation during photoaging.

    PubMed

    Olivier, Elodie; Dutot, Mélody; Regazzetti, Anne; Dargère, Delphine; Auzeil, Nicolas; Laprévote, Olivier; Rat, Patrice

    2016-05-18

    Skin photoaging due to UV irradiation is a degenerative process that appears more and more as a growing concern. Lipids, including oxysterols, are involved in degenerative processes; as skin cells contain various lipids, the aim of our study was to evaluate first, changes in keratinocyte lipid levels induced by UV exposure and second, cellular effects of oxysterols in cell morphology and several hallmarks of keratinocyte differentiation. Our mass spectrometry results demonstrated that UV irradiation induces changes in lipid profile of cultured keratinocytes; in particular, ceramides and oxysterols, specifically 25-hydroxycholesterol (25-OH), were increased. Using holography and confocal microscopy analyses, we highlighted cell thickening and cytoskeletal disruption after incubation of keratinocytes with 25-OH. These alterations were associated with keratinocyte differentiation patterns: autophagy stimulation and intracellular calcium increase as measured by cytofluorometry, and increased involucrin level detected by immunocytochemistry. To conclude, oxysterol deregulation could be considered as a common marker of degenerative disorders. During photoaging, 25-OH seems to play a key role inducing morphological changes and keratinocyte differentiation.

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

    PubMed

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

    2014-08-08

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

  12. Agouti regulates adipocyte transcription factors.

    PubMed

    Mynatt, R L; Stephens, J M

    2001-04-01

    Agouti is a secreted paracrine factor that regulates pigmentation in hair follicle melanocytes. Several dominant mutations cause ectopic expression of agouti, resulting in a phenotype characterized by yellow fur, adult-onset obesity and diabetes, increased linear growth and skeletal mass, and increased susceptibility to tumors. Humans also produce agouti protein, but the highest levels of agouti in humans are found in adipose tissue. To mimic the human agouti expression pattern in mice, transgenic mice (aP2-agouti) that express agouti in adipose tissue were generated. The transgenic mice develop a mild form of obesity, and they are sensitized to the action of insulin. We correlated the levels of specific regulators of insulin signaling and adipocyte differentiation with these phenotypic changes in adipose tissue. Signal transducers and activators of transcription (STAT)1, STAT3, and peroxisome proliferator-activated receptor (PPAR)-gamma protein levels were elevated in the transgenic mice. Treatment of mature 3T3-L1 adipocytes recapitulated these effects. These data demonstrate that agouti has potent effects on adipose tissue. We hypothesize that agouti increases adiposity and promotes insulin sensitivity by acting directly on adipocytes via PPAR-gamma.

  13. Quercetin, a functional compound of onion peel, remodels white adipocytes to brown-like adipocytes.

    PubMed

    Lee, Sang Gil; Parks, John S; Kang, Hye Won

    2017-04-01

    Adipocyte browning is a promising strategy for obesity prevention. Using onion-peel-derived extracts and their bioactive compounds, we demonstrate that onion peel, a by-product of onion, can change the characteristics of white adipocytes to those of brown-like adipocytes in the white adipose tissue of mice and 3T3-L1 cells. The expression of the following brown adipose tissue-specific genes was increased in the retroperitoneal and subcutaneous adipose tissues of 0.5% onion-peel-extract-fed mice: PR domain-containing 16, peroxisome proliferator-activated receptor gamma coactivator 1α, uncoupling protein 1, fibroblast growth factor 21 and cell death-inducing DFFA-like effector. In 3T3-L1 adipocytes, onion peel extract induced the expression of brown adipose tissue-specific genes and increased the expression of carnitine palmitoyltransferase 1α. This effect was supported by decreased lipid levels and multiple small-sized lipid droplets. The ethyl acetate fraction of the onion peel extract that contained the highest proportion of hydrophobic molecules showed the same browning effect in 3T3-L1 adipocytes. A high-performance liquid chromatography analysis further identified quercetin as a functional compound in the browning effect of onion peel. The quercetin-associated browning effect was mediated in part by the activation of AMP-activated protein kinase. In summary, our study provides the first demonstration of the browning effects of onion peel and quercetin using both animal and cell models. This result indicates that onion peel has the potential to remodel the characteristics of white adipocytes to those of brown-like adipocytes.

  14. Impact of lipid phosphatases SHIP2 and PTEN on the time- and Akt-isoform-specific amelioration of TNF-alpha-induced insulin resistance in 3T3-L1 adipocytes.

    PubMed

    Ikubo, Mariko; Wada, Tsutomu; Fukui, Kazuhito; Ishiki, Manabu; Ishihara, Hajime; Asano, Tomoichiro; Tsuneki, Hiroshi; Sasaoka, Toshiyasu

    2009-01-01

    TNF-alpha is a major contributor to the pathogenesis of insulin resistance associated with obesity and inflammation by serine phosphorylating and degrading insulin receptor substrate-1. Presently, we further found that pretreatment with TNF-alpha inhibited insulin-induced phosphorylation of Akt2 greater than Akt1. Since lipid phosphatases SH2-containing inositol 5'-phoshatase 2 (SHIP2) and phosphatase and tensin homologs deleted on chromosome 10 (PTEN) are negative regulators of insulin's metabolic signaling at the step downstream of phosphatidylinositol 3-kinase, we investigated the Akt isoform-specific properties of these phosphatases in the negative regulation after short- and long-term insulin treatment and examined the influence of inhibition on the amelioration of insulin resistance caused by TNF-alpha in 3T3-L1 adipocytes. Adenovirus-mediated overexpression of WT-SHIP2 decreased the phosphorylation of Akt2 greater than Akt1 after insulin stimulation up to 15 min. Expression of a dominant-negative DeltaIP-SHIP2 enhanced the phosphorylation of Akt2 up to 120 min. On the other hand, overexpression of WT-PTEN inhibited the phosphorylation of both Akt1 and Akt2 after short- but not long-term insulin treatment. The expression of DeltaIP-PTEN enhanced the phosphorylation of Akt1 at 120 min and that of Akt2 at 2 min. Interestingly, the expression of DeltaIP-SHIP2, but not DeltaIP-PTEN, protected against the TNF-alpha inhibition of insulin-induced phosphorylation of Akt2, GSK3, and AS160, whereas both improved the TNF-alpha inhibition of insulin-induced 2-deoxyglucose uptake. The results indicate that these lipid phosphatases possess different characteristics according to the time and preference of Akt isoform-dependent signaling in the negative regulation of the metabolic actions of insulin, whereas both inhibitions are effective in the amelioration of insulin resistance caused by TNF-alpha.

  15. Mouse white adipocytes and 3T3-L1 cells display an anomalous pattern of carnitine palmitoyltransferase (CPT) I isoform expression during differentiation. Inter-tissue and inter-species expression of CPT I and CPT II enzymes.

    PubMed Central

    Brown, N F; Hill, J K; Esser, V; Kirkland, J L; Corkey, B E; Foster, D W; McGarry, J D

    1997-01-01

    The outer mitochondrial membrane enzyme carnitine palmitoyltransferase I (CPT I) represents the initial and regulated step in the beta-oxidation of fatty acids. It exists in at least two isoforms, denoted L (liver) and M (muscle) types, with very different kinetic properties and sensitivities to malonyl-CoA. Here we have examined the relative expression of the CPT I isoforms in two different models of adipocyte differentiation and in a number of rat tissues. Adipocytes from mice, hamsters and humans were also evaluated. Primary monolayer cultures of undifferentiated rat preadipocytes expressed solely L-CPT I, but significant levels of M-CPT I emerged after only 3 days of differentiation in vitro; in the mature cell M-CPT I predominated. In sharp contrast, the murine 3T3-L1 preadipocyte expressed essentially exclusively L-CPT I, both in the undifferentiated state and throughout the differentiation process in vitro. This was also true of the mature mouse white fat cell. Fully developed adipocytes from the hamster and human behaved similarly to those of the rat. Thus the mouse white fat cell differs fundamentally from those of the other species examined in terms of tis choice of a key regulatory enzyme in fatty acid metabolism. In contrast, brown adipose tissue from all three rodents displayed the same isoform profiles, each expressing overwhelmingly M-CPT I. Northern blot analysis of other rat tissues established L-CPT I as the dominant isoform not only in liver but also in kidney, lung, ovary, spleen, brain, intestine and pancreatic islets. In addition to its primacy in skeletal muscle, heart and fat, M-CPT I was also found to dominate the testis. The same inter-tissue isoform pattern (with the exception of white fat) was found in the mouse. Taken together, the data bring to light an intriguing divergence between white adipocytes of the mouse and other mammalian species. They also raise a cautionary note that should be considered in the choice of animal model used

  16. Effect of Sutherlandia frutescens on the lipid metabolism in an insulin resistant rat model and 3T3-L1 adipocytes.

    PubMed

    MacKenzie, Janine; Koekemoer, Trevor C; Roux, Saartjie; van de Venter, Maryna; Dealtry, Gill B

    2012-12-01

    High fat diet induced insulin resistance correlates with dyslipidaemia and ectopic fat deposits in skeletal muscle and liver. The effects of Sutherlandia frutescens, an antidiabetic medicinal plant, on lipid metabolism were evaluated in an insulin resistant (IR) rat model and in 3 T3-preadipocytes. Wistar rats received normal diet (ND) or high fat diet (HFD). After the onset of IR in the HFD group, the rats were subdivided into two subgroups, which either continued with HFD or were treated with 50 mg S. frutescens/kg BW/day and HFD (HFD + SF). After 4 weeks, the HFD + SF rats had a significantly lower body weight than the HFD rats (p < 0.05). Blood plasma analysis showed a decrease in insulin, free fatty acids and triglycerides. Related changes in lipid parameters were observed in the liver, skeletal muscle and adipose tissue. To investigate the effects of S. frutescens on adipose tissue, 3 T3-L1 cells were used as a model. Treatment with S. frutescens led to a decrease in triglyceride accumulation, whilst glucose consumption and lactate production were increased (p < 0.05). These results indicate that S. frutescens directly affects mitochondrial activity and lipid biosynthesis in adipose tissue and provide a mechanism by which S. frutescens can restore insulin sensitivity by modulating fatty acid biosynthesis.

  17. Systems Chemo-Biology and Transcriptomic Meta-Analysis Reveal the Molecular Roles of Bioactive Lipids in Cardiomyocyte Differentiation.

    PubMed

    de Faria Poloni, Joice; Bonatto, Diego

    2015-09-01

    Lipids, which are essential constituents of biological membranes, play structural and functional roles in the cell. In recent years, certain lipids have been identified as regulatory signaling molecules and have been termed "bioactive lipids". Subsequently, the importance of bioactive lipids in stem cell differentiation and cardiogenesis has gained increasing recognition. Therefore, the aim of this study was to identify the biological processes underlying murine cardiac differentiation and the mechanisms by which bioactive lipids affect these processes. For this purpose, a transcriptomic meta-analysis of microarray and RNA-seq data from murine stem cells undergoing cardiogenic differentiation was performed. The differentially expressed genes identified via this meta-analysis, as well as bioactive lipids, were evaluated using systems chemo-biology tools. These data indicated that bioactive lipids are associated with the regulation of cell motility, cell adhesion, cytoskeletal rearrangement, and gene expression. Moreover, bioactive lipids integrate the signaling pathways involved in cell migration, the secretion and remodeling of extracellular matrix components, and the establishment of the cardiac phenotype. In conclusion, this study provides new insights into the contribution of bioactive lipids to the induction of cellular responses to various stimuli, which may originate from the extracellular environment and morphogens, and the manner in which this contribution directly affects murine heart morphogenesis.

  18. Differential effect of plant lipids on membrane organization: specificities of phytosphingolipids and phytosterols.

    PubMed

    Grosjean, Kevin; Mongrand, Sébastien; Beney, Laurent; Simon-Plas, Françoise; Gerbeau-Pissot, Patricia

    2015-02-27

    The high diversity of the plant lipid mixture raises the question of their respective involvement in the definition of membrane organization. This is particularly the case for plant plasma membrane, which is enriched in specific lipids, such as free and conjugated forms of phytosterols and typical phytosphingolipids, such as glycosylinositolphosphoceramides. This question was here addressed extensively by characterizing the order level of membrane from vesicles prepared using various plant lipid mixtures and labeled with an environment-sensitive probe. Fluorescence spectroscopy experiments showed that among major phytosterols, campesterol exhibits a stronger ability than β-sitosterol and stigmasterol to order model membranes. Multispectral confocal microscopy, allowing spatial analysis of membrane organization, demonstrated accordingly the strong ability of campesterol to promote ordered domain formation and to organize their spatial distribution at the membrane surface. Conjugated sterol forms, alone and in synergy with free sterols, exhibit a striking ability to order membrane. Plant sphingolipids, particularly glycosylinositolphosphoceramides, enhanced the sterol-induced ordering effect, emphasizing the formation and increasing the size of sterol-dependent ordered domains. Altogether, our results support a differential involvement of free and conjugated phytosterols in the formation of ordered domains and suggest that the diversity of plant lipids, allowing various local combinations of lipid species, could be a major contributor to membrane organization in particular through the formation of sphingolipid-sterol interacting domains.

  19. Microarray analysis of differentially expressed genes regulating lipid metabolism during melanoma progression.

    PubMed

    Sumantran, Venil N; Mishra, Pratik; Sudhakar, N

    2015-04-01

    A new hallmark of cancer involves acquisition of a lipogenic phenotype which promotes tumorigenesis. Little is known about lipid metabolism in melanomas. Therefore, we used BRB (Biometrics Research Branch) class comparison tool with multivariate analysis to identify differentially expressed genes in human cutaneous melanomas, compared with benign nevi and normal skin derived from the microarray dataset (GDS1375). The methods were validated by identifying known melanoma biomarkers (CITED1, FGFR2, PTPRF, LICAM, SPP1 and PHACTR1) in our results. Eighteen genes regulating metabolism of fatty acids, lipid second messengers and gangliosides were 2-9 fold upregulated in melanomas of GDS-1375. Out of the 18 genes, 13 were confirmed by KEGG pathway analysis and 10 were also significantly upregulated in human melanoma cell lines of NCI-60 Cell Miner database. Results showed that melanomas upregulated PPARGC1A transcription factor and its target genes regulating synthesis of fatty acids (SCD) and complex lipids (FABP3 and ACSL3). Melanoma also upregulated genes which prevented lipotoxicity (CPT2 and ACOT7) and regulated lipid second messengers, such as phosphatidic acid (AGPAT-4, PLD3) and inositol triphosphate (ITPKB, ITPR3). Genes for synthesis of pro-tumorigenic GM3 and GD3 gangliosides (UGCG, HEXA, ST3GAL5 and ST8SIA1) were also upregulated in melanoma. Overall, the microarray analysis of GDS-1375 dataset indicated that melanomas can become lipogenic by upregulating genes, leading to increase in fatty acid metabolism, metabolism of specific lipid second messengers, and ganglioside synthesis.

  20. Transdifferentiation properties of adipocytes in the adipose organ.

    PubMed

    Cinti, Saverio

    2009-11-01

    Mammals have two types of adipocytes, white and brown, but their anatomy and physiology is different. White adipocytes store lipids, and brown adipocytes burn them to produce heat. Previous descriptions implied their localization in distinct sites, but we demonstrated that they are mixed in many depots, raising the concept of adipose organ. We explain the reason for their cohabitation with the hypothesis of reversible physiological transdifferentiation; they are able to convert one into each other. If needed, the brown component of the organ could increase at the expense of the white component and vice versa. This plasticity is important because the brown phenotype of the organ associates with resistance to obesity and related disorders. Another example of physiological transdifferetiation of adipocytes is offered by the mammary gland; the pregnancy hormonal stimuli seems to trigger a reversible transdifferentiation of adipocytes into milk-secreting epithelial glands. The obese adipose organ is infiltrated by macrophages inducing chronic inflamation that is widely considered as a causative factor for insulin resistance. We showed that the vast majority of macrophages infiltrating the obese organ are arranged around dead adipocytes, forming characteristic crown-like structures. We recently found that visceral fat is more infiltrated than the subcutaneous fat despite a smaller size of visceral adipocytes. This suggests a different susceptibility of visceral and subcutaneous adipocytes to death, raising the concept of smaller critical death size that could be important to explain the key role of visceral fat for the metabolic disorders associated with obesity.

  1. Macrophage Differentiation from Monocytes Is Influenced by the Lipid Oxidation Degree of Low Density Lipoprotein

    PubMed Central

    Seo, Jin-Won; Yang, Eun-Jeong; Yoo, Kyung-Hwa; Choi, In-Hong

    2015-01-01

    LDL plays an important role in atherosclerotic plaque formation and macrophage differentiation. However, there is no report regarding the oxidation degree of LDL and macrophage differentiation. Our study has shown that the differentiation into M1 or M2 macrophages is related to the lipid oxidation level of LDL. Based on the level of lipid peroxidation, LDL is classified into high-oxidized LDL (hi-oxLDL) and low-oxidized LDL (low-oxLDL). The differentiation profiles of macrophages were determined by surface receptor expression and cytokine secretion profiles. Low-oxLDL induced CD86 expression and production of TNF-α and IL-12p40 in THP-1 cells, indicating an M1 macrophage phenotype. Hi-oxLDL induced mannose receptor expression and production of IL-6 and monocyte chemoattractant protein-1, which mostly match the phenotype of M2 macrophages. Further supporting evidence for an M2 polarization by hi-oxLDL was the induction of LOX-1 in THP-1 cells treated with hi-oxLDL but not with low-oxLDL. Similar results were obtained in primary human monocytes. Therefore, our results strongly suggest that the oxidation degree of LDL influences the differentiation of monocytes into M1 or M2 macrophages and determines the inflammatory fate in early stages of atherosclerosis. PMID:26294848

  2. ADMET: ADipocyte METabolism mathematical model.

    PubMed

    Micheloni, Alessio; Orsi, Gianni; De Maria, Carmelo; Vozzi, Giovanni

    2015-01-01

    White fat cells have an important physiological role in maintaining triglyceride and free fatty acid levels due to their fundamental storage property, as well as determining insulin resistance. ADipocyte METabolism is a mathematical model that mimics the main metabolic pathways of human white fat cell, connecting inputs (composition of culture medium) to outputs (glycerol and free fatty acid release). It is based on a set of nonlinear differential equations, implemented in Simulink® and controlled by cellular energetic state. The validation of this model is based on a comparison between the simulation results and a set of experimental data collected from the literature.

  3. Design, synthesis and characterization of novel binary V(V)-Schiff base materials linked with insulin-mimetic vanadium-induced differentiation of 3T3-L1 fibroblasts to adipocytes. Structure-function correlations at the molecular level.

    PubMed

    Halevas, E; Tsave, O; Yavropoulou, M P; Hatzidimitriou, A; Yovos, J G; Psycharis, V; Gabriel, C; Salifoglou, A

    2015-06-01

    Among the various roles of vanadium in the regulation of intracellular signaling, energy metabolism and insulin mimesis, its exogenous activity stands as a contemporary challenge currently under investigation and a goal to pursue as a metallodrug against Diabetes mellitus II. In this regard, the lipogenic activity of vanadium linked to the development of well-defined anti-diabetic vanadodrugs has been investigated through: a) specifically designing and synthesizing Schiff base organic ligands L, bearing a variable number of terminal alcohols, b) a series of well-defined soluble binary V(V)-L compounds synthesized and physicochemically characterized, c) a study of their cytotoxic effect and establishment of adipogenic activity in 3T3-L1 fibroblasts toward mature adipocytes, and d) biomarker examination of a closely-linked molecular target involving or influenced by the specific V(V) forms, cumulatively delineating factors involved in potential pathways linked to V(V)-induced insulin-like activity. Collectively, the results a) project the importance of specific structural features in Schiff ligands bound to V(V), thereby influencing the emergence of its (a)toxicity and for the first time its insulin-like activity in pre-adipocyte differentiation, b) contribute to the discovery of molecular targets influenced by the specific vanadoforms seeking to induce glucose uptake, and c) indicate an interplay of V(V) structural speciation and cell-differentiation biological activity, thereby gaining insight into vanadium's potential as a future metallodrug in Diabetes mellitus.

  4. Xanthohumol influences preadipocyte differentiation: implication of antiproliferative and apoptotic effects.

    PubMed

    Mendes, Vanda; Monteiro, Rosário; Pestana, Diogo; Teixeira, Diana; Calhau, Conceição; Azevedo, Isabel

    2008-12-24

    There is interest in the research of natural compounds that may interfere with the adipocyte life cycle, due to the growing prevalence of obesity and related complications. We aimed at studying the effect of xanthohumol (XN), a Humulus lupulus L. prenylflavonoid, on adipocytes measuring differentiation, proliferation, and apoptosis in 3T3-L1 cells. XN reduced differentiation, as revealed by decreased lipid content and peroxisome proliferator-activated receptor gamma expression, an effect more pronounced when cells were treated before or during differentiation induction. XN also decreased proliferation, as measured by sulforhodamine staining (IC(50) between 26 and 12 microM for 24, 48, and 72 h), and preadipocyte Ki67 expression. Apoptosis was increased in preadipocytes and adipocytes. NF-kappaB activity was stimulated by XN in preadipocytes. Results suggest that XN may reduce adipocyte number, contributing to adipocyte hypertrophy. Taking into consideration the consequences of adipocyte hypertrophy, XN does not seem to improve the metabolic profile associated with obesity.

  5. Cell kinetics, DNA integrity, differentiation, and lipid fingerprinting analysis of rabbit adipose-derived stem cells.

    PubMed

    Barretto, Letícia Siqueira de Sá; Lessio, Camila; Sawaki e Nakamura, Ahy Natally; Lo Turco, Edson Guimarães; da Silva, Camila Gonzaga; Zambon, João Paulo; Gozzo, Fábio César; Pilau, Eduardo Jorge; de Almeida, Fernando Gonçalves

    2014-10-01

    Human adipose tissue has been described as a potential alternative reservoir for stem cells. Although studies have been performed in rabbits using autologous adipose-derived stem cells (ADSC), these cells have not been well characterized. The primary objectives of this study were to demonstrate the presence of adipose-derived stem cells isolated from rabbit inguinal fat pads and to characterize them through osteogenic and adipogenic in vitro differentiation and lipid fingerprinting analysis. The secondary objective was to evaluate cell behavior through growth kinetics, cell viability, and DNA integrity. Rabbit ADSCs were isolated to determine the in vitro growth kinetics and cell viability. DNA integrity was assessed by an alkaline Comet assay in passages 0 and 5. The osteogenic differentiation was evaluated by Von Kossa, and Alizarin Red S staining and adipogenic differentiation were assessed by Oil Red O staining. Lipid fingerprinting analyses of control, adipogenic, and osteogenic differentiated cells were performed by MALDI-TOF/MS. We demonstrate that rabbit ADSC have a constant growth rate at the early passages, with increased DNA fragmentation at or after passage 5. Rabbit ADSC viability was similar in passages 2 and 5 (90.7% and 86.6%, respectively), but there was a tendency to decreased cellular growth rate after passage 3. The ADSC were characterized by the expression of surface markers such as CD29 (67.4%) and CD44 (89.4%), using CD 45 (0.77%) as a negative control. ADSC from rabbits were successfully isolated form the inguinal region. These cells were capable to differentiate into osteogenic and adipogenic tissue when they were placed in inductive media. After each passage, there was a trend towards decreased cell growth. On the other hand, DNA fragmentation increased at each passage. ADSC had a different lipid profile when placed in control, adipogenic, or osteogenic media.

  6. Adipocyte ATP-binding cassette G1 promotes triglyceride storage, fat mass growth, and human obesity.

    PubMed

    Frisdal, Eric; Le Lay, Soazig; Hooton, Henri; Poupel, Lucie; Olivier, Maryline; Alili, Rohia; Plengpanich, Wanee; Villard, Elise F; Gilibert, Sophie; Lhomme, Marie; Superville, Alexandre; Miftah-Alkhair, Lobna; Chapman, M John; Dallinga-Thie, Geesje M; Venteclef, Nicolas; Poitou, Christine; Tordjman, Joan; Lesnik, Philippe; Kontush, Anatol; Huby, Thierry; Dugail, Isabelle; Clement, Karine; Guerin, Maryse; Le Goff, Wilfried

    2015-03-01

    The role of the ATP-binding cassette G1 (ABCG1) transporter in human pathophysiology is still largely unknown. Indeed, beyond its role in mediating free cholesterol efflux to HDL, the ABCG1 transporter equally promotes lipid accumulation in a triglyceride (TG)-rich environment through regulation of the bioavailability of lipoprotein lipase (LPL). Because both ABCG1 and LPL are expressed in adipose tissue, we hypothesized that ABCG1 is implicated in adipocyte TG storage and therefore could be a major actor in adipose tissue fat accumulation. Silencing of Abcg1 expression by RNA interference in 3T3-L1 preadipocytes compromised LPL-dependent TG accumulation during the initial phase of differentiation. Generation of stable Abcg1 knockdown 3T3-L1 adipocytes revealed that Abcg1 deficiency reduces TG storage and diminishes lipid droplet size through inhibition of Pparγ expression. Strikingly, local inhibition of adipocyte Abcg1 in adipose tissue from mice fed a high-fat diet led to a rapid decrease of adiposity and weight gain. Analysis of two frequent ABCG1 single nucleotide polymorphisms (rs1893590 [A/C] and rs1378577 [T/G]) in morbidly obese individuals indicated that elevated ABCG1 expression in adipose tissue was associated with increased PPARγ expression and adiposity concomitant to increased fat mass and BMI (haplotype AT>GC). The critical role of ABCG1 in obesity was further confirmed in independent populations of severe obese and diabetic obese individuals. This study identifies for the first time a major role of adipocyte ABCG1 in adiposity and fat mass growth and suggests that adipose ABCG1 might represent a potential therapeutic target in obesity.

  7. Artemisia scoparia Enhances Adipocyte Development and Endocrine Function In Vitro and Enhances Insulin Action In Vivo

    PubMed Central

    Richard, Allison J.; Fuller, Scott; Fedorcenco, Veaceslav; Beyl, Robbie; Burris, Thomas P.; Mynatt, Randall; Ribnicky, David M.; Stephens, Jacqueline M.

    2014-01-01

    Background Failure of adipocytes to expand during periods of energy excess can result in undesirable metabolic consequences such as ectopic fat accumulation and insulin resistance. Blinded screening studies have indicated that Artemisia scoparia (SCO) extracts can enhance adipocyte differentiation and lipid accumulation in cultured adipocytes. The present study tested the hypothesis that SCO treatment modulates fat cell development and function in vitro and insulin sensitivity in adipose tissue in vivo. Methods In vitro experiments utilized a Gal4-PPARγ ligand binding domain (LBD) fusion protein-luciferase reporter assay to examine PPARγ activation. To investigate the ability of SCO to modulate adipogenesis and mature fat cell function in 3T3-L1 cells, neutral lipid accumulation, gene expression, and protein secretion were measured by Oil Red O staining, qRT-PCR, and immunoblotting, respectively. For the in vivo experiments, diet-induced obese (DIO) C57BL/6J mice were fed a high-fat diet (HFD) or HFD containing 1% w/w SCO for four weeks. Body weight and composition, food intake, and fasting glucose and insulin levels were measured. Phospho-activation and expression of insulin-sensitizing proteins in epididymal adipose tissue (eWAT) were measured by immunoblotting. Results Ethanolic extracts of A. scoparia significantly activated the PPARγ LBD and enhanced lipid accumulation in differentiating 3T3-L1 cells. SCO increased the transcription of several PPARγ target genes in differentiating 3T3-L1 cells and rescued the negative effects of tumor necrosis factor α on production and secretion of adiponectin and monocyte chemoattractant protein-1 in fully differentiated fat cells. DIO mice treated with SCO had elevated adiponectin levels and increased phosphorylation of AMPKα in eWAT when compared to control mice. In SCO-treated mice, these changes were also associated with decreased fasting insulin and glucose levels. Conclusion SCO has metabolically beneficial

  8. Phlorotannins isolated from the edible brown alga Ecklonia stolonifera exert anti-adipogenic activity on 3T3-L1 adipocytes by downregulating C/EBPα and PPARγ.

    PubMed

    Jung, Hyun Ah; Jung, Hee Jin; Jeong, Hyun Young; Kwon, Hyun Ju; Ali, Md Yousof; Choi, Jae Sue

    2014-01-01

    The dramatic increase in obesity-related diseases emphasizes the need to elucidate the cellular and molecular mechanisms underlying fat metabolism. Inhibition of adipocyte differentiation has been suggested to be an important strategy for preventing or treating obesity. In our previous study, we characterized an Ecklonia stolonifera extract and non-polar fractions thereof, including dichloromethane and ethyl acetate fractions. We showed that these fractions inhibited adipocyte differentiation and lipid formation/accumulation in 3T3-L1 preadipocytes, as assessed by Oil Red O staining. As part of our ongoing search for anti-obesity agents derived from E. stolonifera, in this work, we characterized five known phlorotannins, including phloroglucinol, eckol, dieckol, dioxinodehydroeckol, and phlorofucofuroeckol A, all of which were isolated from the active ethyl acetate fraction of E. stolonifera. We determined the chemical structures of these phlorotannins through comparisons of published nuclear magnetic resonance (NMR) spectral data. Furthermore, we screened these phlorotannins for their abilities to inhibit adipogenesis over a range of concentrations (12.5-100 μM). Of these five phlorotannins, phloroglucinol, eckol, and phlorofucofuroeckol A significantly concentration-dependently inhibited lipid accumulation in 3T3-L1 cells without affecting cell viability. In addition, the five isolated phlorotannins also significantly reduced the expression levels of several adipocyte marker genes, including proliferator activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), although they did so to different extents. These results suggest that the molecular weight of a phlorotannin is an important factor affecting its ability to inhibit adipocyte differentiation and modulate the expression levels of adipocyte marker genes.

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

    PubMed

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

    2014-08-01

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

  10. De Novo Synthesis of Steroids and Oxysterols in Adipocytes*

    PubMed Central

    Li, Jiehan; Daly, Edward; Campioli, Enrico; Wabitsch, Martin; Papadopoulos, Vassilios

    2014-01-01

    Local production and action of cholesterol metabolites such as steroids or oxysterols within endocrine tissues are currently recognized as an important principle in the cell type- and tissue-specific regulation of hormone effects. In adipocytes, one of the most abundant endocrine cells in the human body, the de novo production of steroids or oxysterols from cholesterol has not been examined. Here, we demonstrate that essential components of cholesterol transport and metabolism machinery in the initial steps of steroid and/or oxysterol biosynthesis pathways are present and active in adipocytes. The ability of adipocyte CYP11A1 in producing pregnenolone is demonstrated for the first time, rendering adipocyte a steroidogenic cell. The oxysterol 27-hydroxycholesterol (27HC), synthesized by the mitochondrial enzyme CYP27A1, was identified as one of the major de novo adipocyte products from cholesterol and its precursor mevalonate. Inhibition of CYP27A1 activity or knockdown and deletion of the Cyp27a1 gene induced adipocyte differentiation, suggesting a paracrine or autocrine biological significance for the adipocyte-derived 27HC. These findings suggest that the presence of the 27HC biosynthesis pathway in adipocytes may represent a defense mechanism to prevent the formation of new fat cells upon overfeeding with dietary cholesterol. PMID:24280213

  11. Keratinocyte differentiation and upregulation of ceramide synthesis induced by an oat lipid extract via the activation of PPAR pathways.

    PubMed

    Chon, Su-Hyoun; Tannahill, Ruth; Yao, Xiang; Southall, Michael D; Pappas, Apostolos

    2015-04-01

    Activation of peroxisome proliferator-activated receptors (PPARs) has been shown to have an important role in skin barrier function by regulating differentiation and lipid synthesis in keratinocytes. Oat (Avena sativa) has long been used as a soothing agent to relieve skin irritations, and the clinical benefits of topical oat formulations have been proven; however, the mechanistic understanding of oat's mode of action remains unknown. We investigated whether an oat lipid extract could activate PPARs and subsequently increase epidermal lipid synthesis and differentiation markers. Primary human epidermal keratinocytes and transformed cell lines were treated with PPAR agonists and oat lipid extracts to investigate the PPAR agonism. PPAR target genes and epidermal differentiation markers were analysed using quantitative real-time PCR and HPTLC analysis. Oat lipid extract demonstrated robust dual agonism for PPARα and PPARβ/δ, and increased direct PPAR target gene induction in primary human keratinocytes. In addition, oat oil treatment increased both receptor expression and, consistent with the literature on PPARs, oat oil treatment resulted in a significant upregulation of differentiation genes (involucrin, SPRRs and transglutaminase 1) and ceramide processing genes (β-glucocerebrosidase, sphingomyelinases 3 and ABCA12). Further, oat oil treatment in keratinocytes significantly increased ceramide levels (70%), suggesting a functional translation of PPAR activation by oat oil in keratinocytes. Taken together, these results demonstrate that oat lipids possess robust dual agonistic activities for PPARα and PPARβ/δ, increase their gene expression and induce differentiation and ceramide synthesis in keratinocytes, which can collectively improve skin barrier function.

  12. Communication between natural killer T cells and adipocytes in obesity

    PubMed Central

    Satoh, Masashi; Iwabuchi, Kazuya

    2016-01-01

    ABSTRACT Adipose tissue contains various types of immunocompetent cells, and these cells of innate and adaptive immunity control adipose tissue inflammation that blunts insulin sensitivity. Recent studies have shown that adipocytes express CD1d and present lipid antigen(s) to activate natural killer T (NKT) cells. The function of adipocytes is in turn modulated by cytokines that NKT cells produce to alter the expression of anti-inflammatory adipokine(s) and the production of inflammatory and chemoattractant cytokines. These in vitro studies imply that the interaction between adipocytes and NKT cells might affect the development of not only obesity but also obesity-related diseases. To test the importance of the interaction between NKT cells and adipocytes, we examined whether an adipocyte-specific CD1d deletion affected the development of obesity, which had been demonstrated with B6.CD1d−/− (CD1d KO). We found that the interaction is indeed important to induce adipose tissue inflammation and insulin resistance in response to lipid excess. In this commentary, the advances and controversies on NKT cells and obesity are discussed based on our recent report that NKT cells play a pivotal role in the regulation of adipose tissue by communicating with adipocytes via CD1d. PMID:27994954

  13. Anti-adipogenic activity of the edible brown alga Ecklonia stolonifera and its constituent fucosterol in 3T3-L1 adipocytes.

    PubMed

    Jung, Hyun Ah; Jung, Hee Jin; Jeong, Hyun Young; Kwon, Hyun Ju; Kim, Min-Sun; Choi, Jae Sue

    2014-06-01

    Fucosterol is a sterol metabolite of brown algae and regulates genes involved with cholesterol homeostasis. As a part of our continuous search for anti-obesity agents from natural marine sources, the anti-adipogenic activities of Ecklonia stolonifera and its sterol, fucosterol, were evaluated for the inhibition of adipocyte differentiation and lipid formation. Oil Red O staining was used to evaluate triglyceride contents in 3T3-L1 pre-adipocytes primed by differentiation medium (DM) I and DM II. The methanolic extract of E. stolonifera showed strong anti-adipogenic activity, and was thus fractionated with several solvents. Among the tested fractions, the dichloromethane (CH2Cl2) fraction was found to be the most active fraction, with significant inhibition (40.5 %) of intracellular lipid accumulation at a non-toxic concentration, followed by the ethyl acetate fraction (30.2 %) at the same concentration, while the n-butanol and water fractions did not show inhibitory activity within the tested concentrations. The strong anti-adipogenic CH2Cl2-soluble fraction was further purified by a repeated chromatography to yield fucosterol. Fucosterol reduced lipid contents in a concentration-dependent manner without showing any cytotoxicity. Fucosterol treatment also yielded a decrease in the expression of the adipocyte marker proteins peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα) in a concentration-dependent manner. Taken together, these results suggest that fucosterol inhibits expression of PPARγ and C/EBPα, resulting in a decrease of lipid accumulation in 3T3-L1 pre-adipocytes, indicating that the potential use of E. stolonifera and its bioactive fucosterol as an anti-obesity agent.

  14. Brown adipogenic potential of brown adipocytes and peri-renal adipocytes from human embryo

    PubMed Central

    Wu, Nan-Nan; Zhang, Chuan-Hai; Lee, Hyuek-Jong; Ma, Yan; Wang, Xin; Ma, Xiao-Juan; Ma, Wei; Zhao, Dong; Feng, Ying-Mei

    2016-01-01

    Both brown adipocytes (BAC) and beige cells hold therapeutic potential for the treatment of metabolic disorders. Unfortunately, the amount and activity of these cells are limited in adults. Although BAC marker expression has been shown in peri-renal adipose tissues in children and adults, functional assessment is lacking. Furthermore, it is entirely unknown whether adipose progenitors are present in human embryo and able to give rise to BAC in situ during evolution. Therefore, adipose tissues in the interscapular and peri-renal regions were dissected from human embryo and subcutaneous white adipose tissues (sWAT) were obtained from an adult. After subjected to differentiation in vitro, adipocyte progenitors were detected present in all these adipose tissues. When stimulated for adipogenesis, differentiated adipocytes in the intercapular and peri-renal regions showed similar features: (1) induced BAC and beige cell marker expression including UCP1 and PRDM16 and comparable mitochondrion copy number; (2) similar gene expression patterns by RNA-Seq analysis; and (3) similar maximal oxygen consumption rates examined by respirometry. Nevertheless, stimulation of adipocyte progenitors in sWAT induces neither BAC and beige cell marker expression nor any change of oxygen consumption. In conclusion, peri-renal adipocyte progenitors in human embryo hold browning potential for BAC production. PMID:27982067

  15. Metabolic Flux Analysis of Mitochondrial Uncoupling in 3T3-L1 Adipocytes

    PubMed Central

    Si, Yaguang; Shi, Hai; Lee, Kyongbum

    2009-01-01

    Background Increasing energy expenditure at the cellular level offers an attractive option to limit adiposity and improve whole body energy balance. In vivo and in vitro observations have correlated mitochondrial uncoupling protein-1 (UCP1) expression with reduced white adipose tissue triglyceride (TG) content. The metabolic basis for this correlation remains unclear. Methodology/Principal Findings This study tested the hypothesis that mitochondrial uncoupling requires the cell to compensate for the decreased oxidation phosphorylation efficiency by up-regulating lactate production, thus redirecting carbon flux away from TG synthesis. Metabolic flux analysis was used to characterize the effects of non-lethal, long-term mitochondrial uncoupling (up to 18 days) on the pathways of intermediary metabolism in differentiating 3T3-L1 adipocytes. Uncoupling was induced by forced expression of UCP1 and chemical (FCCP) treatment. Chemical uncoupling significantly decreased TG content by ca. 35%. A reduction in the ATP level suggested diminished oxidative phosphorylation efficiency in the uncoupled adipocytes. Flux analysis estimated significant up-regulation of glycolysis and down-regulation of fatty acid synthesis, with chemical uncoupling exerting quantitatively larger effects. Conclusions/Significance The results of this study support our hypothesis regarding uncoupling-induced redirection of carbon flux into glycolysis and lactate production, and suggest mitochondrial proton translocation as a potential target for controlling adipocyte lipid metabolism. PMID:19746157

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

    SciTech Connect

    Kim, Nam Soo; Kim, Yoon-Jin; Cho, Si Young; Lee, Tae Ryong; Kim, Sang Hoon

    2013-09-27

    Highlights: •MRAP enhanced HSL expression. •ACTH-mediated MRAP reduced glycerol release. •PPARγ induced MRAP expression. •PPARγ bound to the MRAP promoter. -- Abstract: Adrenocorticotropic hormone (ACTH) in rodents decreases lipid accumulation and body weight. Melanocortin receptor 2 (MC2R) and MC2R accessory protein (MRAP) are specific receptors for ACTH in adipocytes. Peroxisome proliferator-activated receptor γ (PPARγ) plays a role in the transcriptional regulation of metabolic pathways such as adipogenesis and β-oxidation of fatty acids. In this study we investigated the transcriptional regulation of MRAP expression during differentiation of 3T3-L1 cells. Stimulation with ACTH affected lipolysis in murine mature adipocytes via MRAP. Putative peroxisome proliferator response element (PPRE) was identified in the MRAP promoter region. In chromatin immunoprecipitation and reporter assays, we observed binding of PPARγ to the MRAP promoter. The mutagenesis experiments showed that the −1209/−1198 region of the MRAP promoter could function as a PPRE site. These results suggest that PPARγ is required for transcriptional activation of the MRAP gene during adipogenesis, which contributes to understanding of the molecular mechanism of lipolysis in adipocytes.

  17. Interleukin-4 regulates lipid metabolism by inhibiting adipogenesis and promoting lipolysis

    PubMed Central

    Tsao, Chang-Hui; Shiau, Ming-Yuh; Chuang, Pei-Hua; Chang, Yih-Hsin; Hwang, Jaulang

    2014-01-01

    Long-term cytokine-mediated inflammation is a risk factor for obesity and type 2 diabetes mellitus (T2DM). Our previous studies reveal significant associations between promoter single nucleotide polymorphisms (SNPs) of interleukin (IL)-4 and T2DM, as well as between SNPs in genes encoding IL-4/IL-4 receptor and high density lipoproteins. Our animal study reveals that IL-4 regulates glucose/lipid metabolism by promoting glucose tolerance and inhibiting lipid deposits. The above results strongly suggest the involvement of IL-4 in energy homeostasis. In the present study, we focus on examining the regulatory mechanism of IL-4 to lipid metabolism. Our results show that IL-4 inhibits adipogenesis by downregulating the expression of peroxisome proliferator-activated receptor-γ and CCAAT/enhancer-binding protein-α. Additionally, IL-4 promotes lipolysis by enhancing the activity and translocation of hormone sensitive lipase (HSL) in mature adipocytes, which suggests that IL-4 plays a pro-lipolytic role in lipid metabolism by boosting HSL activity. Our results demonstrate that IL-4 harbors pro-lipolysis capacity by inhibiting adipocyte differentiation and lipid accumulation as well as by promoting lipolysis in mature adipocytes to decrease lipid deposits. The above findings uncover the novel roles of IL-4 in lipid metabolism and provide new insights into the interactions among cytokine/immune responses, insulin sensitivity, and metabolism. PMID:24347527

  18. Small GTPase Rab40c Associates with Lipid Droplets and Modulates the Biogenesis of Lipid Droplets

    PubMed Central

    Tan, Ran; Wang, Weijie; Wang, Shicong; Wang, Zhen; Sun, Lixiang; He, Wei; Fan, Rong; Zhou, Yunhe; Xu, Xiaohui; Hong, Wanjin; Wang, Tuanlao

    2013-01-01

    The subcellular location and cell biological function of small GTPase Rab40c in mammalian cells have not been investigated in detail. In this study, we demonstrated that the exogenously expressed GFP-Rab40c associates with lipid droplets marked by neutral lipid specific dye Oil red or Nile red, but not with the Golgi or endosomal markers. Further examination demonstrated that Rab40c is also associated with ERGIC-53 containing structures, especially under the serum starvation condition. Rab40c is increasingly recruited to the surface of lipid droplets during lipid droplets formation and maturation in HepG2 cells. Rab40c knockdown moderately decreases the size of lipid droplets, suggesting that Rab40c is involved in the biogenesis of lipid droplets. Stimulation for adipocyte differentiation increases the expression of Rab40c in 3T3-L1 cells. Rab40c interacts with TIP47, and is appositionally associated with TIP47-labeled lipid droplets. In addition, over-expression of Rab40c causes the clustering of lipid droplets independent of its GTPase activity, but completely dependent of the intact SOCS box domain of Rab40c. In addition, Rab40c displayed self-interaction as well as interaction with TIP47 and the SOCS box is essential for its ability to induce clustering of lipid droplets. Our results suggest that Rab40c is a novel Rab protein associated with lipid droplets, and is likely involved in modulating the biogenesis of lipid droplets. PMID:23638186

  19. Differential signalling pathways for EGF versus PDGF activation of Erk1/2 MAP kinase and cell proliferation in brown pre-adipocytes

    SciTech Connect

    Holmstroem, Therese E.; Mattsson, Charlotte L.; Faelting, Johanna M.; Nedergaard, Jan

    2008-11-15

    Stimulation by both adrenergic and non-adrenergic pathways can induce proliferation of brown pre-adipocytes. To understand the signalling pathways involved in non-adrenergic stimulation of cell proliferation, we examined Erk1/2 activation. In primary cultures of mouse brown pre-adipocytes, both EGF (epidermal growth factor) and PDGF (platelet-derived growth factor) induced Erk1/2 activation. EGF-stimulated Erk1/2 activation involved Src tyrosine kinases, but not PKC or PI3K, whereas in PDGF-induced Erk1/2 activation, PI3K, PKC (probably the atypical {zeta} isoform) and Src were involved sequentially. Both EGF and PDGF induced PI3K-dependent Akt activation that was not involved in Erk1/2 activation. By comparing effects of signalling inhibitors (wortmannin, SH-6, TPA, Goe6983, PP2, PD98059) on EGF- and PDGF-induced Erk1/2 activation and cell proliferation ({sup 3}H-thymidine incorporation), we conclude that while the signal transduction pathways initiated by these growth factors are clearly markedly different, their effects on cell proliferation can be fully explained through their stimulation of Erk1/2 activation; thus Erk1/2 is a common, essential step for stimulation of proliferation in these cells.

  20. Differential effects of pertussis toxin on insulin-stimulated phosphatidylcholine hydrolysis and glycerolipid synthesis de novo. Studies in BC3H-1 myocytes and rat adipocytes

    SciTech Connect

    Hoffman, J.M.; Standaert, M.L.; Nair, G.P.; Farese, R.V. )

    1991-04-02

    Insulin-induced increases in diacylglycerol (DAG) have been suggested to result from stimulation of de novo phosphatidic acid (PA) synthesis and phosphatidylcholine (PC) hydrolysis. Presently, the authors found that insulin decreased PC levels of BC3H-1 myocytes and rat adipocytes by approximately 10-25% within 30 s. These decreases were rapidly reversed in both cell types, apparently because of increased PC synthesis de novo. In BC3H-1 myocytes, pertussis toxin inhibited PC resynthesis and insulin effects on the pathway of de novo PA-DAG-PC synthesis, as evidenced by changes in ({sup 3}H)glycerol incorporation, but did not inhibit insulin-stimulated PC hydrolysis. Pertussis toxin also blocked the later, but not the initial, increase in DAG production in the myocytes. Phorbol esters activated PC hydrolysis in both myocytes and adipocytes, but insulin-induced stimulation of PC hydrolysis was not dependent upon activation of PKC, since this hydrolysis was not inhibited by 500 {mu}M sangivamycin, an effective PKC inhibitor. The results indicate that insulin increases DAG by pertussis toxin sensitive and insensitive (PC hydrolysis) mechanisms, which are mechanistically separate, but functionally interdependent and integrated. PC hydrolysis may contribute importantly to initial increases in DAG, but later sustained increases are apparently largely dependent on insulin-induced stimulation of the pathway of de novo phospholipid synthesis.

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

    PubMed Central

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

    2016-01-01

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

  2. Cancer Cells Differentially Activate and Thrive on De Novo Lipid Synthesis Pathways in a Low-Lipid Environment

    PubMed Central

    Daniëls, Veerle W.; Smans, Karine; Royaux, Ines; Chypre, Melanie

    2014-01-01

    Increased lipogenesis is a hallmark of a wide variety of cancers and is under intense investigation as potential antineoplastic target. Although brisk lipogenesis is observed in the presence of exogenous lipids, evidence is mounting that these lipids may adversely affect the efficacy of inhibitors of lipogenic pathways. Therefore, to fully exploit the therapeutic potential of lipid synthesis inhibitors, a better understanding of the interrelationship between de novo lipid synthesis and exogenous lipids and their respective role in cancer cell proliferation and therapeutic response to lipogenesis inhibitors is of critical importance. Here, we show that the proliferation of various cancer cell lines (PC3M, HepG2, HOP62 and T24) is attenuated when cultured in lipid-reduced conditions in a cell line-dependent manner, with PC3M being the least affected. Interestingly, all cell lines - lipogenic (PC3M, HepG2, HOP62) as well as non-lipogenic (T24) - raised their lipogenic activity in these conditions, albeit to a different degree. Cells that attained the highest lipogenic activity under these conditions were best able to cope with lipid reduction in term of proliferative capacity. Supplementation of the medium with very low density lipoproteins, free fatty acids and cholesterol reversed this activation, indicating that the mere lack of lipids is sufficient to activate de novo lipogenesis in cancer cells. Consequently, cancer cells grown in lipid-reduced conditions became more dependent on de novo lipid synthesis pathways and were more sensitive to inhibitors of lipogenic pathways, like Soraphen A and Simvastatin. Collectively, these data indicate that limitation of access to exogenous lipids, as may occur in intact tumors, activates de novo lipogenesis is cancer cells, helps them to thrive under these conditions and makes them more vulnerable to lipogenesis inhibitors. These observations have important implications for the design of new antineoplastic strategies targeting

  3. Human skeletal muscle fibroblasts, but not myogenic cells, readily undergo adipogenic differentiation.

    PubMed

    Agley, Chibeza C; Rowlerson, Anthea M; Velloso, Cristiana P; Lazarus, Norman R; Harridge, Stephen D R

    2013-12-15

    We characterised the adherent cell types isolated from human skeletal muscle by enzymatic digestion, and demonstrated that even at 72 hours after isolation these cultures consisted predominantly of myogenic cells (CD56(+), desmin(+)) and fibroblasts (TE-7(+), collagen VI(+), PDGFRα(+), vimentin(+), fibronectin(+)). To evaluate the behaviour of the cell types obtained, we optimised a double immuno-magnetic cell-sorting method for the separation of myogenic cells from fibroblasts. This procedure gave purities of >96% for myogenic (CD56(+), desmin(+)) cells. The CD56(-) fraction obtained from the first sort was highly enriched in TE-7(+) fibroblasts. Using quantitative analysis of immunofluorescent staining for lipid content, lineage markers and transcription factors, we tested if the purified cell populations could differentiate into adipocytes in response to treatment with either fatty acids or adipocyte-inducing medium. Both treatments caused the fibroblasts to differentiate into adipocytes, as shown by loss of intracellular TE-7, upregulation of the adipogenic transcription factors PPARγ and C/EBPα, and adoption of a lipid-laden adipocyte morphology. By contrast, myogenic cells did not undergo adipogenesis and showed differential regulation of PPARγ and C/EBPα in response to these adipogenic treatments. Our results show that human skeletal muscle fibroblasts are at least bipotent progenitors that can remain as extracellular-matrix-producing cells or differentiate into adipocytes.

  4. Technical note: Isolation and characterization of ovine brown adipocyte precursor cells.

    PubMed

    Ma, X; Hou, Y Q; Dahanayaka, S; Satterfield, M C; Burghardt, R C; Bazer, F W; Wu, G

    2015-05-01

    Brown adipose tissue (BAT) plays a critical role in regulating body temperature in newborn lambs. Availability of a stable BAT cell line would be invaluable for biochemical studies to elucidate cellular and molecular mechanisms responsible for nutritional regulation of fetal BAT growth and development. Ovine brown adipocyte precursor cells (BAPC) were isolated from fetal lambs at d 90 of gestation and cultured to establish a stable cell line. These cells were characterized by adipogenic differentiation and expression of a hallmark gene, (). The BAPC doubled every 24 h. After a 9-d induction with a serum-free Dulbecco's modified Eagle Ham/F12 medium, BAPC differentiated into brown adipocytes with large lipid droplets. The differentiation medium induced expression of mRNA and protein in BAPC. Furthermore, after BAPC were passaged 30 times, they maintained similar cell morphology, the potential for adipogenic differentiation, and the ability to express . Taken together, we have established a stable ovine BAPC cell line for studying nutritional regulation of BAT growth and development in the fetus.

  5. Asiatic acid inhibits adipogenic differentiation of bone marrow stromal cells.

    PubMed

    Li, Zheng-Wei; Piao, Cheng-dong; Sun, Hong-hui; Ren, Xian-Sheng; Bai, Yun-Shen

    2014-03-01

    Bone marrow mesenchymal stromal cells (BMSCs) are the common precursors for both osteoblasts and adipocytes. With aging, BMSC osteoblast differentiation decreases whereas BMSC differentiation into adipocytes increases, resulting in increased adipogenesis and bone loss. In the present study, we investigated the effect of asiatic acid (AA) on adipocytic differentiation of BMSCs. AA inhibited the adipogenic induction of lipid accumulation, activity of glycerol-3-phosphate dehydrogenase, and expression of marker genes in adipogenesis: peroxisome proliferation-activated receptor (PPAR)γ, adipocyte fatty acid-binding protein (ap) 2, and adipsin. Further, we found that AA did not alter clonal expansion rate and expression of C/EBPβ, upstream key regulator of PPARγ, and binding activity of C/EBPβ to PPARγ promoter was not affected by AA as well. These findings suggest that AA may modulate differentiation of BMSCs to cause a lineage shift away from the adipocytes, and inhibition of PPARγ by AA is through C/EBPβ-independent mechanisms. Thus, AA could be a potential candidate for a novel drug against osteoporosis.

  6. Aspartame downregulates 3T3-L1 differentiation.

    PubMed

    Pandurangan, Muthuraman; Park, Jeongeun; Kim, Eunjung

    2014-10-01

    Aspartame is an artificial sweetener used as an alternate for sugar in several foods and beverages. Since aspartame is 200 times sweeter than traditional sugar, it can give the same level of sweetness with less substance, which leads to lower-calorie food intake. There are reports that consumption of aspartame-containing products can help obese people lose weight. However, the potential role of aspartame in obesity is not clear. The present study investigated whether aspartame suppresses 3T3-L1 differentiation, by downregulating phosphorylated peroxisome proliferator-activated receptor γ (p-PPARγ), peroxisome proliferator-activated receptor γ (PPARγ), fatty acid-binding protein 4 (FABP4), CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1), which are critical for adipogenesis. The 3T3-L1 adipocytes were cultured and differentiated for 6 d in the absence and presence of 10 μg/ml of aspartame. Aspartame reduced lipid accumulation in differentiated adipocytes as evidenced by Oil Red O staining. qRT-PCR analysis showed that the PPARγ, FABP4, and C/EBPα mRNA expression was significantly reduced in the aspartame-treated adipocytes. Western blot analysis showed that the induction of p-PPARγ, PPARγ, SREBP1, and adipsin was markedly reduced in the aspartame-treated adipocytes. Taken together, these data suggest that aspartame may be a potent substance to alter adipocyte differentiation and control obesity.

  7. Lkb1 deletion promotes ectopic lipid accumulation in muscle progenitor cells and mature muscles.

    PubMed

    Shan, Tizhong; Zhang, Pengpeng; Bi, Pengpeng; Kuang, Shihuan

    2015-05-01

    Excessive intramyocellular triglycerides (muscle lipids) are associated with reduced contractile function, insulin resistance, and Type 2 diabetes, but what governs lipid accumulation in muscle is unclear. Here we report a role of Lkb1 in regulating lipid metabolism in muscle stem cells and their descendent mature muscles. We used Myod(Cre) and Lkb1(flox/flox) mice to specifically delete Lkb1 in myogenic cells including stem and differentiated cells, and examined the lipid accumulation and gene expression of myoblasts cultured from muscle stem cells (satellite cells). Genetic deletion of Lkb1 in myogenic progenitors led to elevated expression of lipogenic genes and ectopic lipid accumulation in proliferating myoblasts. Interestingly, the Lkb1-deficient myoblasts differentiated into adipocyte-like cells upon adipogenic induction. However, these adipocyte-like cells maintained myogenic gene expression with reduced ability to form myotubes efficiently. Activation of AMPK by AICAR prevented ectopic lipid formation in the Lkb1-null myoblasts. Notably, Lkb1-deficient muscles accumulated excessive lipids in vivo in response to high-fat diet feeding. These results demonstrate that Lkb1 acts through AMPK to limit lipid deposition in muscle stem cells and their derivative mature muscles, and point to the possibility of controlling muscle lipid content using AMPK activating drugs.

  8. Urothelial Carcinoma with shadow cell, lipid cell and sebaceous (skin adnexal) differentiation: Clinicopathological and immunohistochemical study of 10 cases.

    PubMed

    Behzatoğlu, Kemal

    2015-10-01

    We discuss the histological and immunohistochemical features of 6 cases of urothelial carcinomas of lipid cell variant and 4 cases with shadow cell differentiation, one of which showed additionally sebaceous differentiation, one of which shows additional sebaceous differentiation, from our archive cases from the last 15 years. Conventional urothelial carcinoma (UC) was seen in all lipid cell variant cases, and micropapillary carcinoma was seen in 3. The ratio of the lipid cell component was between 10% and 40% in these 6 cases. Typical histologic features of the lipid cell variant include lipoblast-like cells with a notched nuclear appearance, abundant vacuoles, an eccentric nucleus, and pagetoid spread in some areas. GATA3 and pancytokeratin AE1/AE3 immunohistochemical staining were positive in all cases. Adipophilin was positive in various degrees in 5 of the 6 lipid cell variant cases but was also positive in the case with sebaceous differentiation. α-methylacyl-CoA racemase was positive in the lipid cell areas and negative or focal weakly positive in the conventional UC areas in 4 of the 6 cases. Vimentin, S-100 protein, and PAX8 were negative in the lipid cell component. Follow-up information was available for all cases with follow-up ranging from 6 to 84 months (mean, 34 months). Four patients died of the disease. One pT4 patient who had been followed up for 6 months lives with the disease, whereas another is disease free. In conclusion, the lipid cell variant is a rare UC variant that usually presents at an advanced stage, and tumor cells are histologically similar to lipoblasts, resemble sebaceous differentiation, and show positive immunohistochemical staining with adipophilin.

  9. LINGO-1 regulates oligodendrocyte differentiation by inhibiting ErbB2 translocation and activation in lipid rafts.

    PubMed

    Lee, Xinhua; Shao, Zhaohui; Sheng, Guoqing; Pepinsky, Blake; Mi, Sha

    2014-05-01

    Oligodendrocyte differentiation is negatively regulated by LINGO-1 and positively regulated by the ErbB2 receptor tyrosine kinase. In wild-type oligodendrocytes, inhibition of ErbB2 blocks differentiation, whereas activation of ErbB2 promotes differentiation. In LINGO-1(-/-) oligodendrocytes, inhibition of ErbB2 blocks oligodendrocyte differentiation; whereas activation of ErbB2 does not enhance differentiation. Biological and biochemical evidence showing that LINGO-1 can directly bind to ErbB2, block ErbB2 translocation into lipid rafts, and inhibit its phosphorylation for activation. The study demonstrates a novel regulatory mechanism of ErbB2 function whereby LINGO-1 suppresses oligodendrocyte differentiation by inhibiting ErbB2 translocation and activation in lipid rafts.

  10. TLR4 ligands lipopolysaccharide and monophosphoryl lipid a differentially regulate effector and memory CD8+ T Cell differentiation.

    PubMed

    Cui, Weiguo; Joshi, Nikhil S; Liu, Ying; Meng, Hailong; Kleinstein, Steven H; Kaech, Susan M

    2014-05-01

    Vaccines formulated with nonreplicating pathogens require adjuvants to help bolster immunogenicity. The role of adjuvants in Ab production has been well studied, but how they influence memory CD8(+) T cell differentiation remains poorly defined. In this study we implemented dendritic cell-mediated immunization to study the effects of commonly used adjuvants, TLR ligands, on effector and memory CD8(+) T cell differentiation in mice. Intriguingly, we found that the TLR4 ligand LPS was far more superior to other TLR ligands in generating memory CD8(+) T cells upon immunization. LPS boosted clonal expansion similar to the other adjuvants, but fewer of the activated CD8(+) T cells died during contraction, generating a larger pool of memory cells. Surprisingly, monophosphoryl lipid A (MPLA), another TLR4 ligand, enhanced clonal expansion of effector CD8(+) T cells, but it also promoted their terminal differentiation and contraction; thus, fewer memory CD8(+) T cells formed, and MPLA-primed animals were less protected against secondary infection compared with those primed with LPS. Furthermore, gene expression profiling revealed that LPS-primed effector cells displayed a stronger pro-memory gene expression signature, whereas the gene expression profile of MPLA-primed effector cells aligned closer with terminal effector CD8(+) T cells. Lastly, we demonstrated that the LPS-TLR4-derived "pro-memory" signals were MyD88, but not Toll/IL-1R domain-containing adapter inducing IFN-β, dependent. This study reveals the influential power of adjuvants on the quantity and quality of CD8(+) T cell memory, and that attention to adjuvant selection is crucial because boosting effector cell expansion may not always equate with more memory T cells or greater protection.

  11. Ceiling culture-derived proliferative adipocytes retain high adipogenic potential suitable for use as a vehicle for gene transduction therapy.

    PubMed

    Asada, Sakiyo; Kuroda, Masayuki; Aoyagi, Yasuyuki; Fukaya, Yoshitaka; Tanaka, Shigeaki; Konno, Shunichi; Tanio, Masami; Aso, Masayuki; Satoh, Kaneshige; Okamoto, Yoshitaka; Nakayama, Toshinori; Saito, Yasushi; Bujo, Hideaki

    2011-07-01

    Adipose tissue is expected to provide a source of proliferative cells for regenerative medicine and cell-transplantation therapies using gene transfer manipulation. We have recently identified ceiling culture-derived proliferative adipocytes (ccdPAs) from the mature adipocyte fraction as cells suitable as a therapeutic gene vehicle because of their stable proliferative capacity. In this study, we examined the capability of adipogenic differentiation of the ccdPAs compared with stromal vascular fraction (SVF)-derived progenitor cells (adipose-derived stem cells, ASCs) with regard to their multipotential ability to be converted to another lineage and therefore their potential to be used for regenerative medicine research. After in vitro passaging, the surface antigen profile and the basal levels of adipogenic marker genes of the ccdPAs were not obviously different from those of the ASCs. However, the ccdPAs showed increased lipid-droplet accumulation accompanied with higher adipogenic marker gene expression after stimulation of differentiation compared with the ASCs. The higher adipogenic potential of the ccdPAs than the ASCs from the SVF was maintained for 42 days in culture. Furthermore, the difference in the adipogenic response was enhanced after partial stimulation without indomethacin. These results indicate that the ccdPAs retain a high adipogenic potential even after in vitro passaging, thus suggesting the commitment of ccdPAs to stable mature adipocytes after autotransplantation, indicating that they may have potential for use in regenerative and gene-manipulated medicine.

  12. Berberine regulates peroxisome proliferator-activated receptors and positive transcription elongation factor b expression in diabetic adipocytes.

    PubMed

    Zhou, Jiyin; Zhou, Shiwen

    2010-12-15

    Berberine has hypoglycemic and hypolipidemic effects on diabetic rats. This study investigated the relationship between hypoglycemic and hypolipidemic effects of berberine and peroxisome proliferator-activated receptors (PPARs) and positive transcription elongation factor b (P-TEFb) (including cyclin-dependent kinase 9 (CDK9) and cyclin T1) in white adipose tissue of diabetic rats and RNA interference-treated 3T3-L1 cells. Berberine promoted differentiation and inhibited lipid accumulation of 3T3-L1 cells, further decreased PPARα/δ/γ, CDK9 and cyclin T1 mRNA and protein expression and decreased tumor necrosis factor α content in supernatants of both control and RNA interference-treated 3T3-L1 cells. After a 16-week induction with 35 mg/kg streptozotocin (i.p.) and high-carbohydrate/high-fat diet, diabetic rats were treated with 75, 150 and 300 mg/kg berberine and 100 mg/kg fenofibrate or 4 mg/kg rosiglitazone for another 16 weeks. Berberine decreased white adipose tissue to body weight ratio and adipocyte size and increased adipocyte number. Berberine upregulated PPARα/δ/γ, CDK9 and cyclin T1 mRNA and protein expression in adipose tissue, decreased tumor necrosis factor α and free fatty acid content and increased lipoprotein lipase activity in serum and adipose tissue. Berberine modulated metabolic related PPARs expression and differentiation related P-TEFb expression in adipocytes, which are associated with its hypoglycemic and hypolipidemic effects.

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

    PubMed

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

    2013-03-01

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

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

    PubMed Central

    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 differentially expressed genes between adipocytes derived from human SQ vs. PV adipose tissues. Although >90% of well-expressed genes were similarly regulated, we identified a signature of 307 differentially expressed genes that were highly enriched for functions associated with the regulation of angiogenesis, vascular morphology, inflammation, and blood clotting. Of the 156 PV upregulated genes, 59 associate with angiogenesis, vascular biology, or inflammation, noteworthy of which include TNFRSF11B (osteoprotegerin), PLAT, TGFB1, THBS2, HIF1A, GATA6, and SERPINE1. Of 166 PV downregulated genes, 21 associated with vascular biology and inflammation, including ANGPT1, ANGPTL1, and VEGFC. Consistent with the emergent hypothesis that PV adipocytes differentially regulate angiogenesis and inflammation, cell culture-derived adipocyte-conditioned media from PV adipocytes strongly enhanced endothelial cell tubulogenesis and monocyte migration compared with media from SQ adipocytes. These findings demonstrate that PV adipocytes have the potential to significantly modulate vascular inflammatory crosstalk in the setting of atherosclerosis by their ability to signal to both endothelial and inflammatory cells. PMID:23737535

  15. Cytotoxicity and inhibitory effects of low-concentration triclosan on adipogenic differentiation of human mesenchymal stem cells

    SciTech Connect

    Guo, Li-Wu; Wu, Qiangen; Green, Bridgett; Nolen, Greg; Shi, Leming; LoSurdo, Jessica; Deng, Helen; Bauer, Steven; Fang, Jia-Long; Ning, Baitang

    2012-07-15

    Humans at all ages are continually exposed to triclosan (TCS), a widely used antimicrobial agent that can be found in many daily hygiene products, such as toothpastes and shampoos; however, the toxicological and biological effects of TCS in the human body after long-term and low-concentration exposure are far from being well understood. In the current study, we investigated the effects of TCS on the differentiation of human mesenchymal stem cells (hMSCs) by measuring the cytotoxicity, morphological changes, lipid accumulation, and the expression of adipocyte differentiation biomarkers during 21-day adipogenesis. Significant cytotoxicity was observed in un-induced hMSCs treated with high-concentration TCS (≥ 5.0 μM TCS), but not with low-concentration treatments (≤ 2.5 μM TCS). TCS inhibited adipocyte differentiation of hMSCs in a concentration-dependent manner in the 0.156 to 2.5 μM range as indicated by morphological changes with Oil Red O staining, which is an index of lipid accumulation. The inhibitory effect was confirmed by a decrease in gene expression of specific adipocyte differentiation biomarkers including adipocyte protein 2, lipoprotein lipase, and adiponectin. Our study demonstrates that TCS inhibits adipocyte differentiation of hMSCs under concentrations that are not cytotoxic and in the range observed in human blood. -- Highlights: ► TCS is cytotoxic to un-induced hMSCs at concentrations ≥ 5.0 μM. ► TCS at concentrations ≤ 2.5 μM is not cytotoxic to induced hMSCs. ► TCS at non-cytotoxic concentrations inhibits lipid formation in induced hMSCs. ► TCS decreases the expression of specific biomarkers of adipocyte differentiation. ► TCS at concentrations observed in human blood inhibits adipogenesis of hMSCs.

  16. CaMKII-MEDIATED PHOSPHORYLATION OF THE BOMBYX MORI LIPID STORAGE DROPLET PROTEIN-1 (BmLsd1), AN INSECT PAT FAMILY PROTEIN, IS ESSENTIAL FOR SILKMOTH SEX PHEROMONE BIOSYNTHESIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The structurally-related members of the PAT family of proteins, which are so name based on similarity amongst perilipin, adipophilin/adipocyte differentiation-related protein (ADRP), and tail-interacting protein of 47 kilodaltons (TIP47), are cytoplasmic lipid droplet (LD)-associated proteins charac...

  17. Hormone signaling linked to silkmoth sex pheromone biosynthesis involves Ca2+/calmodulin-dependent protein kinase II-mediated phosphorylation of the insect PAT family protein Bombyx mori lipid storage droplet protein-1(BmLsd)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The structurally-related members of the PAT family of proteins, which are so name based on similarity amongst perilipin, adipophilin/adipocyte differentiation-related protein (ADRP), and tail-interacting protein of 47 kilodaltons (TIP47), are cytoplasmic lipid droplet (LD)-associated proteins charac...

  18. Human osteoblasts derived from mesenchymal stem cells express adipogenic markers upon coculture with bone marrow adipocytes.

    PubMed

    Clabaut, Aline; Delplace, Séverine; Chauveau, Christophe; Hardouin, Pierre; Broux, Odile

    2010-07-01

    In osteoporosis, bone loss is accompanied by greater adiposity in the marrow. Given the cellular proximity within the bone marrow, we wondered whether adipocytes might have a paracrine impact on osteoblast differentiation. To test this hypothesis, we cocultured adipocytes with osteoblasts derived from mesenchymal stem cells (MSCs) in the absence of direct cell contact and then analyzed gene expression changes in the osteoblastic population by using real-time reverse transcription polymerase chain reaction. We found that, upon coculture, MSC-derived osteoblasts showed appearance of adipogenic (lipoprotein lipase, leptin) and decrease of osteogenic (osteocalcin) mRNA markers. Our results indicate that in vitro, MSC-derived adipocytes are capable of inducing MSC-derived osteoblasts to differentiate to an adipocyte phenotype. These new data suggest that (i) transdifferentiation of committed osteoblasts into adipocytes may contribute to the increase in marrow fat content at the expense of bone-forming cells and (ii) this switch might be initiated by the adipocytes themselves.

  19. Notch activation drives adipocyte dedifferentiation and tumorigenic transformation in mice

    PubMed Central

    Yue, Feng; Karki, Anju; Castro, Beatriz; Wirbisky, Sara E.; Bidwell, Christopher A.; Freeman, Jennifer L.

    2016-01-01

    Liposarcomas (LPSs) are the most common soft-tissue cancer. Because of the lack of animal models, the cellular origin and molecular regulation of LPS remain unclear. Here, we report that mice with adipocyte-specific activation of Notch signaling (Ad/N1ICD) develop LPS with complete penetrance. Lineage tracing confirms the adipocyte origin of Ad/N1ICD LPS. The Ad/N1ICD LPS resembles human dedifferentiated LPS in histological appearance, anatomical localization, and gene expression signature. Before transformation, Ad/N1ICD adipocytes undergo dedifferentiation that leads to lipodystrophy and metabolic dysfunction. Although concomitant Pten deletion normalizes the glucose metabolism of Ad/N1ICD mice, it dramatically accelerates the LPS prognosis and malignancy. Transcriptomes and lipidomics analyses indicate that Notch activation suppresses lipid metabolism pathways that supply ligands to Pparγ, the master regulator of adipocyte homeostasis. Accordingly, synthetic Pparγ ligand supplementation induces redifferentiation of Ad/N1ICD adipocytes and tumor cells, and prevents LPS development in Ad/N1ICD mice. Importantly, the Notch target HES1 is abundantly expressed in human LPS, and Notch inhibition suppresses the growth of human dedifferentiated LPS xenografts. Collectively, ectopic Notch activation is sufficient to induce dedifferentiation and tumorigenic transformation of mature adipocytes in mouse. PMID:27573812

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

    PubMed

    Parray, Hilal Ahmad; Yun, Jong Won

    2016-05-01

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

  1. Bidirectional Lipid Droplet Velocities Are Controlled by Differential Binding Strengths of HCV Core DII Protein

    PubMed Central

    Lyn, Rodney K.; Hope, Graham; Sherratt, Allison R.; McLauchlan, John; Pezacki, John Paul

    2013-01-01

    Host cell lipid droplets (LD) are essential in the hepatitis C virus (HCV) life cycle and are targeted by the viral capsid core protein. Core-coated LDs accumulate in the perinuclear region and facilitate viral particle assembly, but it is unclear how mobility of these LDs is directed by core. Herein we used two-photon fluorescence, differential interference contrast imaging, and coherent anti-Stokes Raman scattering microscopies, to reveal novel core-mediated changes to LD dynamics. Expression of core protein’s lipid binding domain II (DII-core) induced slower LD speeds, but did not affect directionality of movement on microtubules. Modulating the LD binding strength of DII-core further impacted LD mobility, revealing the temporal effects of LD-bound DII-core. These results for DII-core coated LDs support a model for core-mediated LD localization that involves core slowing down the rate of movement of LDs until localization at the perinuclear region is accomplished where LD movement ceases. The guided localization of LDs by HCV core protein not only is essential to the viral life cycle but also poses an interesting target for the development of antiviral strategies against HCV. PMID:24223760

  2. Adipocytes as immune regulatory cells

    PubMed Central

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

    2013-01-01

    Obesity is a chronic inflammatory state and adipocytes are capable of contributing to this inflammation by their production of inflammatory mediators. The present study used fibroblast-derived adipocytes and normal spleen cells as a model to determine if adipocytes can also serve as immune regulatory cells by modulating the functions of conventional immune cells. Media conditioned by the adipocytes stimulated release of the Th1-type cytokines IL-2, IFN-γ and GM-CSF from cultures of normal spleen cells. The adipocytes also stimulated spleen cell release of inhibitory cytokines, although to varying degrees. This included IL-10, IL-13 and, to a lesser extent, IL-4. Spleen cell production of the inflammatory cytokines IL-6, TNF-α and IL-9 was stimulated by adipocytes, although production of the Th17-derived cytokine, IL-17, was not stimulated. The adipocyte-conditioned medium did not stimulate production of predominantly monocytes-derived chemokines CXCL9, CCL2, CCL3, CCL4, but stimulated production of the predominantly T-cell-derived chemokine CCL5. In all cases where cytokine/chemokine production from spleen cells was stimulated by adipocytes, it was to a far greater level than was produced by the adipocytes themselves. Studies initiated to determine the identity of the adipocyte-derived mediators showed that the spleen cell modulation could not be attributed to solely adiponectin or leptin. Studies to determine the source of some of the cytokines whose production was stimulated by adipocytes showed that expression of the inflammatory cytokine IL-6 was not increased in either CD4+ or CD8+ T-cell. When the splenic T-cells were examined for IFN-γ, the adipocyte stimulation of IFN-γ was within CD8+ T-cells, not CD4+ T-cells. These studies show that adipocytes may be able to serve as immune regulatory cells to stimulate conventional immune cells to release a spectrum of immune mediators. PMID:23587489

  3. Endoplasmic Reticulum Stress Regulates Adipocyte Resistin Expression

    PubMed Central

    Lefterova, Martina I.; Mullican, Shannon E.; Tomaru, Takuya; Qatanani, Mohammed; Schupp, Michael; Lazar, Mitchell A.

    2009-01-01

    OBJECTIVE Resistin is a secreted polypeptide that impairs glucose metabolism and, in rodents, is derived exclusively from adipocytes. In murine obesity, resistin circulates at elevated levels but its gene expression in adipose tissue is paradoxically reduced. The mechanism behind the downregulation of resistin mRNA is poorly understood. We investigated whether endoplasmic reticulum (ER) stress, which is characteristic of obese adipose tissue, regulates resistin expression in cultured mouse adipocytes. RESEARCH DESIGN AND METHODS The effects of endoplasmic stress inducers on resistin mRNA and secreted protein levels were examined in differentiated 3T3-L1 adipocytes, focusing on the expression and genomic binding of transcriptional regulators of resistin. The association between downregulated resistin mRNA and induction of ER stress was also investigated in the adipose tissue of mice fed a high-fat diet. RESULTS ER stress reduced resistin mRNA in 3T3-L1 adipocytes in a time- and dose-dependent manner. The effects of ER stress were transcriptional because of downregulation of CAAT/enhancer binding protein-α and peroxisome proliferator–activated receptor-γ transcriptional activators and upregulation of the transcriptional repressor CAAT/enhancer binding protein homologous protein-10 (CHOP10). Resistin protein was also substantially downregulated, showing a close correspondence with mRNA levels in 3T3-L1 adipocytes as well as in the fat pads of obese mice. CONCLUSIONS ER stress is a potent regulator of resistin, suggesting that ER stress may underlie the local downregulation of resistin mRNA and protein in fat in murine obesity. The paradoxical increase in plasma may be because of various systemic abnormalities associated with obesity and insulin resistance. PMID:19491212

  4. Distinct adipogenic differentiation phenotypes of human umbilical cord mesenchymal cells dependent on adipogenic conditions.

    PubMed

    Saben, Jessica; Thakali, Keshari M; Lindsey, Forrest E; Zhong, Ying; Badger, Thomas M; Andres, Aline; Shankar, Kartik

    2014-10-01

    The umbilical cord (UC) matrix is a source of multipotent mesenchymal stem cells (MSCs) that have adipogenic potential and thus can be a model to study adipogenesis. However, existing variability in adipocytic differentiation outcomes may be due to discrepancies in methods utilized for adipogenic differentiation. Additionally, functional characterization of UCMSCs as adipocytes has not been described. We tested the potential of three well-established adipogenic cocktails containing IBMX, dexamethasone, and insulin (MDI) plus indomethacin (MDI-I) or rosiglitazone (MDI-R) to stimulate adipocyte differentiation in UCMSCs. MDI, MDI-I, and MDI-R treatment significantly increased peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT-enhancer binding protein alpha (C/EBPα) mRNA and induced lipid droplet formation. However, MDI-I had the greatest impact on mRNA expression of PPARγ, C/EBPα, FABP4, GPD1, PLIN1, PLIN2, and ADIPOQ and lipid accumulation, whereas MDI showed the least. Interestingly, there were no treatment group differences in the amount of PPARγ protein. However, MDI-I treated cells had significantly more C/EBPα protein compared to MDI or MDI-R, suggesting that indomethacin-dependent increased C/EBPα may contribute to the adipogenesis-inducing potency of MDI-I. Additionally, bone morphogenetic protein 4 (BMP4) treatment of UCMSCs did not enhance responsiveness to MDI-induced differentiation. Finally to characterize adipocyte function, differentiated UCMSCs were stimulated with insulin and downstream signaling was assessed. Differentiated UCMSCs were responsive to insulin at two weeks but showed decreased sensitivity by five weeks following differentiation, suggesting that long-term differentiation may induce insulin resistance. Together, these data indicate that UCMSCs undergo adipogenesis when differentiated in MDI, MDI-I, and MDI-R, however the presence of indomethacin greatly enhances their adipogenic potential beyond that of

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

    PubMed Central

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

    2013-01-01

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

  6. Murine keratinocyte cultures grown at the air/medium interface synthesize stratum corneum lipids and recycle linoleate during differentiation

    SciTech Connect

    Madison, K.C.; Swartzendruber, D.C.; Wertz, P.W.; Downing, D.T.

    1989-07-01

    In a recent investigation we showed that murine keratinocyte cultures grown at the air/medium interface in the presence of dermis exhibit morphologic differentiation comparable to that seen in vivo, including the formation of lamellar granules and stratum corneum intercellular lipid lamellae. In the present study, lifted cultures were found to more closely reproduce the lipid composition of the parent epidermal tissue than submerged cultures grown on plastic. In addition, the specific fatty acid profile of individual lipid classes in lifted cultures was, in general, remarkably well maintained in vitro. Acylceramides, which are highly enriched in linoleic acid in vivo, remained enriched in vitro; however, the linoleic acid content of the cultures was substantially lower than that in vivo, confirming previous reports of the relative essential fatty acid deficiency of standard culture media. As the lifted cultures differentiated over time, the lipid composition changed to reflect the formation of a stratum corneum with its different complement of lipids. Label from (U-/sup 14/C)linoleic acid was specifically incorporated into linoleate-containing lipids during short pulses in both submerged and lifted cultures. Changes in label distribution over a long chase period in lifted cultures indicated that linoleate was transferred from phospholipids to ceramides, providing evidence for the ''recycling'' of essential fatty acids in epidermis.

  7. Murine keratinocyte cultures grown at the air/medium interface synthesize stratum corneum lipids and "recycle" linoleate during differentiation.

    PubMed

    Madison, K C; Swartzendruber, D C; Wertz, P W; Downing, D T

    1989-07-01

    In a recent investigation we showed that murine keratinocyte cultures grown at the air/medium interface in the presence of dermis exhibit morphologic differentiation comparable to that seen in vivo, including the formation of lamellar granules and stratum corneum intercellular lipid lamellae. In the present study, lifted cultures were found to more closely reproduce the lipid composition of the parent epidermal tissue than submerged cultures grown on plastic. In addition, the specific fatty acid profile of individual lipid classes in lifted cultures was, in general, remarkably well maintained in vitro. Acylceramides, which are highly enriched in linoleic acid in vivo, remained enriched in vitro; however, the linoleic acid content of the cultures was substantially lower than that in vivo, confirming previous reports of the relative essential fatty acid deficiency of standard culture media. As the lifted cultures differentiated over time, the lipid composition changed to reflect the formation of a stratum corneum with its different complement of lipids. Label from [U-14C]linoleic acid was specifically incorporated into linoleate-containing lipids during short pulses in both submerged and lifted cultures. Changes in label distribution over a long chase period in lifted cultures indicated that linoleate was transferred from phospholipids to ceramides, providing evidence for the "recycling" of essential fatty acids in epidermis.

  8. Protein Carbonylation and Adipocyte Mitochondrial Function*

    PubMed Central

    Curtis, Jessica M.; Hahn, Wendy S.; Stone, Matthew D.; Inda, Jacob J.; Droullard, David J.; Kuzmicic, Jovan P.; Donoghue, Margaret A.; Long, Eric K.; Armien, Anibal G.; Lavandero, Sergio; Arriaga, Edgar; Griffin, Timothy J.; Bernlohr, David A.

    2012-01-01

    Carbonylation is the covalent, non-reversible modification of the side chains of cysteine, histidine, and lysine residues by lipid peroxidation end products such as 4-hydroxy- and 4-oxononenal. In adipose tissue the effects of such modifications are associated with increased oxidative stress and metabolic dysregulation centered on mitochondrial energy metabolism. To address the role of protein carbonylation in the pathogenesis of mitochondrial dysfunction, quantitative proteomics was employed to identify specific targets of carbonylation in GSTA4-silenced or overexpressing 3T3-L1 adipocytes. GSTA4-silenced adipocytes displayed elevated carbonylation of several key mitochondrial proteins including the phosphate carrier protein, NADH dehydrogenase 1α subcomplexes 2 and 3, translocase of inner mitochondrial membrane 50, and valyl-tRNA synthetase. Elevated protein carbonylation is accompanied by diminished complex I activity, impaired respiration, increased superoxide production, and a reduction in membrane potential without changes in mitochondrial number, area, or density. Silencing of the phosphate carrier or NADH dehydrogenase 1α subcomplexes 2 or 3 in 3T3-L1 cells results in decreased basal and maximal respiration. These results suggest that protein carbonylation plays a major instigating role in cytokine-dependent mitochondrial dysfunction and may be linked to the development of insulin resistance in the adipocyte. PMID:22822087

  9. Persicaria hydropiper (L.) spach and its flavonoid components, isoquercitrin and isorhamnetin, activate the Wnt/β-catenin pathway and inhibit adipocyte differentiation of 3T3-L1 cells.

    PubMed

    Lee, Soung-Hoon; Kim, Bora; Oh, Myoung Jin; Yoon, Juyong; Kim, Hyun Yi; Lee, Kye Jong; Lee, Joo Dong; Choi, Kang-Yell

    2011-11-01

    Obesity, which is related to metabolic syndrome and is associated with liver disease, represents an epidemic problem demanding effective therapeutic strategies. Evidence shows that the Wnt/β-catenin pathway is closely associated with obesity and that small molecules regulating the Wnt/β-catenin pathway can potentially control adipogenesis related to obesity. Eleven plant extracts activating the Wnt/β-catenin pathway were screened by using HEK 293-TOP cells retaining the Wnt/β-catenin signaling reporter gene. An extract of Persicaria hydropiper (L.) Spach was found to activate Wnt/β-catenin signaling. P. hydropiper is grown worldwide in temperate climates and is found widely in Southeast Asia. The P. hydropiper extract inhibited the differentiation of adipocyte 3T3-L1 cells. Isoquercitrin and isorhamnetin, constituents of P. hydropiper, also activated Wnt/β-catenin signaling and suppressed the differentiation of 3T3-L1 cells. These results indicate that isoquercitrin in P. hydropiper suppresses the adipogenesis of 3T3-L1 cells via the inhibition of Wnt/β-catenin signaling. P. hydropiper and isoquercitrin may therefore be potential therapeutic agents for obesity and its associated disorders.

  10. Chromatic aberration correction and deconvolution for UV sensitive imaging of fluorescent sterols in cytoplasmic lipid droplets.

    PubMed

    Wüstner, Daniel; Faergeman, Nils J

    2008-08-01

    Intrinsically fluorescent sterols, like dehydroergosterol (DHE), mimic cholesterol closely and are therefore suitable to determine cholesterol transport by fluorescence microscopy. Disadvantages of DHE are its low quantum yield, rapid bleaching, and the fact that its excitation and emission is in the UV region of the spectrum. Thus, one has to deal with chromatic aberration and low signal-to-noise ratio. We developed a method to correct for chromatic aberration between the UV channel and the red/green channel in multicolor imaging of DHE compared with the lipid droplet marker Nile Red in living macrophage foam cells and in adipocytes. We used deconvolution microscopy and developed image segmentation techniques to assess the DHE content of lipid droplets in both cell types in an automated manner. Pulse-chase studies and colocalization analysis were performed to monitor the redistribution of DHE upon adipocyte differentiation. DHE is targeted to transferrin-positive recycling endosomes in preadipocytes but associates with droplets in mature adipocytes. Only in adipocytes but not in foam cells fluorescent sterol was confined to the droplet-limiting membrane. We developed an approach to visualize and quantify sterol content of lipid droplets in living cells with potential for automated high content screening of cellular sterol transport.

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

    PubMed Central

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

    2015-01-01

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

  12. Mature adipocyte-derived cells, dedifferentiated fat cells (DFAT), promoted functional recovery from spinal cord injury-induced motor dysfunction in rats.

    PubMed

    Ohta, Yuki; Takenaga, Mitsuko; Tokura, Yukie; Hamaguchi, Akemi; Matsumoto, Taro; Kano, Koichiro; Mugishima, Hideo; Okano, Hideyuki; Igarashi, Rie

    2008-01-01

    Transplantation of mature adipocyte-derived cells (dedifferentiated fat cells) led to marked functional recovery from spinal cord injury (SCI)-induced motor dysfunction in rats. When mature adipocytes were isolated from rat adipose tissue and grown in ceiling culture, transformation into fibroblast-like cells without lipid droplets occurred. These fibroblast-like cells, termed dedifferentiated fat cells (DFAT), could proliferate and could also differentiate back into adipocytes. DFAT expressed neural markers such as nestin, betaIII tubulin, and GFAP. Allografting of DFAT into SCI-induced rats led to significant recovery from hindlimb dysfunction. Grafted cells were detected at the injection site, and some of these cells expressed betaIII tubulin. DFAT expressed neurotrophic factors such as BDNF and GDNF prior to transplantation, and grafted cells were also positive for these factors. Therefore, these neurotrophic factors derived from grafted DFAT might have contributed to the promotion of functional recovery. These findings also suggest that mature adipocytes could become a new source for cell replacement therapy to treat central nervous system disorders.

  13. Notch pathway is dispensable for adipocyte specification.

    PubMed

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

    2004-09-01

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

  14. Transcriptional activation of peroxisome proliferator-activated receptor-{gamma} requires activation of both protein kinase A and Akt during adipocyte differentiation

    SciTech Connect

    Kim, Sang-pil; Ha, Jung Min; Yun, Sung Ji; Kim, Eun Kyoung; Chung, Sung Woon; Hong, Ki Whan; Kim, Chi Dae; Bae, Sun Sik

    2010-08-13

    Research highlights: {yields} Elevated cAMP activates both PKA and Epac. {yields} PKA activates CREB transcriptional factor and Epac activates PI3K/Akt pathway via Rap1. {yields} Akt modulates PPAR-{gamma} transcriptional activity in concert with CREB. -- Abstract: Peroxisome proliferator-activated receptor-{gamma} (PPAR-{gamma}) is required for the conversion of pre-adipocytes. However, the mechanism underlying activation of PPAR-{gamma} is unclear. Here we showed that cAMP-induced activation of protein kinase A (PKA) and Akt is essential for the transcriptional activation of PPAR-{gamma}. Hormonal induction of adipogenesis was blocked by a phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002), by a protein kinase A (PKA) inhibitor (H89), and by a Rap1 inhibitor (GGTI-298). Transcriptional activity of PPAR-{gamma} was markedly enhanced by 3-isobutyl-1-methylxanthine (IBMX), but not insulin and dexamethasone. In addition, IBMX-induced PPAR-{gamma} transcriptional activity was blocked by PI3K/Akt, PKA, or Rap1 inhibitors. 8-(4-Chlorophenylthio)-2'-O-methyl-cAMP (8-pCPT-2'-O-Me-cAMP) which is a specific agonist for exchanger protein directly activated by cAMP (Epac) significantly induced the activation of Akt. Furthermore, knock-down of Akt1 markedly attenuated PPAR-{gamma} transcriptional activity. These results indicate that both PKA and Akt signaling pathways are required for transcriptional activation of PPAR-{gamma}, suggesting post-translational activation of PPAR-{gamma} might be critical step for adipogenic gene expression.

  15. Adipogenic differentiation of stem cells in three-dimensional porous bacterial nanocellulose scaffolds.

    PubMed

    Krontiras, Panagiotis; Gatenholm, Paul; Hägg, Daniel A

    2015-01-01

    There is an increased interest in developing adipose tissue for in vitro and in vivo applications. Current two-dimensional (2D) cell-culture systems of adipocytes are limited, and new methods to culture adipocytes in three-dimensional (3D) are warranted as a more life-like model to study metabolic diseases such as obesity and diabetes. In this study, we have evaluated different porous bacterial nanocellulose scaffolds for 3D adipose tissue. In an initial pilot study, we compared adipogenic differentiation of mice mesenchymal stem cells from a cell line on 2D and 3D scaffolds of bacterial nanocellulose. The 3D scaffolds were engineered by crosslinking homogenized cellulose fibrils using alginate and freeze drying the mixture to obtain a porous structure. Quenching the scaffolds in liquid nitrogen resulted in smaller pores compared to slower freezing using isopropanol. We found that on 2D surfaces, the cells were scarcely distributed and showed limited formation of lipid droplets, whereas cells grown in macroporous 3D scaffolds contained more cells growing in clusters, containing large lipid droplets. All four types of scaffolds contained a lot of adipocytes, but scaffolds with smaller pores contained larger cell clusters than scaffolds with bigger pores, with viable adipocytes present even 4 weeks after differentiation. Scaffolds with lower alginate fractions retained their pore integrity better. We conclude that 3D culturing of adipocytes in bacterial nanocellulose macroporous scaffolds is a promising method for fabrication of adipose tissue as an in vitro model for adipose biology and metabolic disease.

  16. Hormone and pharmaceutical regulation of ASP production in 3T3-L1 adipocytes.

    PubMed

    Gao, Ying; Gauvreau, Danny; Cianflone, Katherine

    2010-04-01

    Several studies have demonstrated increases in acylation stimulating protein (ASP), and precursor protein C3 in obesity, diabetes and dyslipidemia, however the nature of the regulation is unknown. To evaluate chronic hormonal and pharmaceutical mediated changes in ASP and potential mechanisms, 3T3-L1 adipocytes were treated with physiological concentrations of relevant hormones and drugs currently used in treatment of metabolic diseases for 48 h. Medium ASP production and C3 secretion were evaluated in relation to changes in adipocyte lipid metabolism (cellular triglyceride (TG) mass, non-esterified fatty acid (NEFA) release and real-time FA uptake). Chylomicrons increased ASP production (up to 411 +/- 133% P < 0.05), while leptin, triiodothyronine, and beta-blockers atenolol and propranolol had no effect. Dexamethasone, lovastatin, rosiglitazone and rimonabant decreased ASP production (-53 to -85%, P < 0.05), associated with a decrease in the precursor protein C3 (-37% to -65%, P < 0.01). By contrast, epinephrine, progesterone, testosterone, angiotensin II and metformin also decreased ASP (-54% to -100%, P < 0.05), but without change in precursor protein C3, suggesting a direct effect on convertase activity, possibly mediated by interference (except metformin) due to marked increases in NEFA (5.6-31-fold, increased P < 0.05). Both lovastatin and metformin induced decreases in ASP were also associated with decreased TG mass (maximal -60%, P < 0.05) and real-time FA uptake (maximum -75%, P < 0.05), suggesting a change in adipocyte differentiation status. These in vitro results are consistent with in vivo ASP profiles in subjects, and suggest that ASP may be regulated through precursor C3 availability, convertase activity and differentiation status.

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

    PubMed

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

    2013-07-01

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

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

    PubMed

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

    2016-01-29

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

  19. Structural investigation of ginsenoside Rf with PPARγ major transcriptional factor of adipogenesis and its impact on adipocyte

    PubMed Central

    Siraj, Fayeza Md; Natarajan, Sathishkumar; Huq, Md Amdadul; Kim, Yeon Ju; Yang, Deok Chun

    2014-01-01

    Background Adipocytes, which are the main cellular component of adipose tissue, are the building blocks of obesity. The nuclear hormone receptor PPARγ is a major regulator of adipocyte differentiation and development. Obesity, which is one of the most dangerous yet silent diseases of all time, is fast becoming a critical area of research focus. Methods In this study, we initially aimed to investigate whether the ginsenoside Rf, a compound that is only present in Panax ginseng Meyer, interacts with PPARγ by molecular docking simulations. After we performed the docking simulation the result has been analyzed with several different software programs, including Discovery Studio, Pymol, Chimera, Ligplus, and Pose View. All of the programs identified the same mechanism of interaction between PPARγ and Rf, at the same active site. To determine the drug-like and biological activities of Rf, we calculate its absorption, distribution, metabolism, excretion, and toxic (ADMET) and prediction of activity spectra for substances (PASS) properties. Considering the results obtained from the computational investigations, the focus was on the in vitro experiments. Results Because the docking simulations predicted the formation of structural bonds between Rf and PPARγ, we also investigated whether any evidence for these bonds could be observed at the cellular level. These experiments revealed that Rf treatment of 3T3-L1 adipocytes downregulated the expression levels of PPARγ and perilipin, and also decreased the amount of lipid accumulated at different doses. Conclusion The ginsenoside Rf appears to be promising compound that could prove useful in antiobesity treatments. PMID:26045687

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

    PubMed Central

    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

  1. Differential control of ATGL-mediated lipid droplet degradation by CGI-58 and G0S2.

    PubMed

    Lu, Xin; Yang, Xingyuan; Liu, Jun

    2010-07-15

    Lipid droplets (LDs) are intracellular storage sites for triacylglyerols (TAGs)and steryl esters, and play essential roles in energy metabolism and membrane biosynthesis. Adipose triglyceride lipase (ATGL) is the key enzyme for TAG hydrolysis (lipolysis) in adipocytes and LD degradation in nonadipocyte cells. Lipase activity of ATGL in vivo largely depends on its C-terminal sequence as well as coactivation by CGI-58. Here we demonstrate that the C-terminal hydrophobic domain in ATGL is required for LD targeting and CGI-58-independent LD degradation. Overexpression of wild type ATGL causes a dramatic decrease in LD size and number, whereas a mutant lacking the hydrophobic domain fails to localize to LDs and to affect their morphology. Interestingly, coexpression of CGI-58 is able to promote LD turnover mediated by this ATGL mutant. Recently we have discovered that G0S2 acts as an inhibitor of ATGL activity and ATGL-mediated lipolysis. Here we show that G0S2 binds to ATGL irrelevantly of its activity state or the presence of CGI-58. In G0S2-expressing cells, the combined expression of CGI-58 and ATGL is incapable of stimulating LD turnover. We propose that CGI-58 and G0S2 regulate ATGL via non-competing mechanisms.

  2. Conditioned media cause increases in select osteogenic and adipogenic differentiation markers in mesenchymal stem cell cultures.

    PubMed

    Maxson, Scott; Burg, Karen J L

    2008-01-01

    The optimal mesenchymal stem cell (MSC) culture conditions that would allow clinically viable tissue-engineered devices are still yet to be determined. Most MSCs are found in the bone marrow, an area that also contains numerous osteoblasts and adipocytes. Paracrine signalling may be leveraged to modulate MSC differentiation in the preparation of a tissue-engineered device. Thus, the objectives of this study were to determine the effects of adipocyte-conditioned medium (CM) on MSC differentiation to osteoblasts and to determine the effects of osteoblast CM on MSC differentiation to adipocytes. Two groups of murine MSCs were given either an osteogenic differentiation medium or an adipogenic differentiation medium. CM was taken from one group and administered to the opposite group in concentrations of 25% or 50%. Metabolic activity, total protein and alkaline phosphatase (ALP) assays were conducted on the osteogenic group at predefined time points throughout the 21 day study, while metabolic activity, triglyceride and oil red O assays were conducted on the adipogenic group at predefined time points. Adipocyte CM administered at a concentration of 50% increased the ALP production of MSCs undergoing osteogenic differentiation. Additionally, osteoblast CM increased the triglyceride production of MSCs undergoing adipogenic differentiation and enlarged the lipid vesicles that were produced by the cells. The effects of the osteoblast CM were seen at both concentrations, but were greatest at the 50% CM level.

  3. Chemotherapy Agents Alter Plasma Lipids in Breast Cancer Patients and Show Differential Effects on Lipid Metabolism Genes in Liver Cells.

    PubMed

    Sharma, Monika; Tuaine, Jo; McLaren, Blair; Waters, Debra L; Black, Katherine; Jones, Lynnette M; McCormick, Sally P A

    2016-01-01

    Cardiovascular complications have emerged as a major concern for cancer patients. Many chemotherapy agents are cardiotoxic and some appear to also alter lipid profiles, although the mechanism for this is unknown. We studied plasma lipid levels in 12 breast cancer patients throughout their chemotherapy. Patients received either four cycles of doxorubicin and cyclophosphamide followed by weekly paclitaxel or three cycles of epirubicin, cyclophosphamide and 5'-fluorouracil followed by three cycles of docetaxel. Patients demonstrated a significant reduction (0.32 mmol/L) in high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (apoA1) levels (0.18 g/L) and an elevation in apolipoprotein B (apoB) levels (0.15 g/L) after treatment. Investigation of the individual chemotherapy agents for their effect on genes involved in lipoprotein metabolism in liver cells showed that doxorubicin decreased ATP binding cassette transporter A1 (ABCA1) via a downregulation of the peroxisomal proliferator activated receptor γ (PPARγ) and liver X receptor α (LXRα) transcription factors. In contrast, ABCA1 levels were not affected by cyclophosphamide or paclitaxel. Likewise, apoA1 levels were reduced by doxorubicin and remained unaffected by cyclophosphamide and paclitaxel. Doxorubicin and paclitaxel both increased apoB protein levels and paclitaxel also decreased low density lipoprotein receptor (LDLR) protein levels. These findings correlate with the observed reduction in HDL-C and apoA1 and increase in apoB levels seen in these patients. The unfavourable lipid profiles produced by some chemotherapy agents may be detrimental in the longer term to cancer patients, especially those already at risk of cardiovascular disease (CVD). This knowledge may be useful in tailoring effective follow-up care plans for cancer survivors.

  4. Differential distribution of lipids in epidermis, gastrodermis and hosted Symbiodinium in the sea anemone Anemonia viridis.

    PubMed

    Revel, Johana; Massi, Lionel; Mehiri, Mohamed; Boutoute, Marc; Mayzaud, Patrick; Capron, Laure; Sabourault, Cécile

    2016-01-01

    Cnidarian-dinoflagellate symbiosis mainly relies on nutrient recycling, thus providing both partners with a competitive advantage in nutrient-poor waters. Essential processes related to lipid metabolism can be influenced by various factors, including hyperthermal stress. This can affect the lipid content and distribution in both partners, while contributing to symbiosis disruption and bleaching. In order to gain further insight into the role and distribution of lipids in the cnidarian metabolism, we investigated the lipid composition of the sea anemone Anemonia viridis and its photosynthetic dinoflagellate endosymbionts (Symbiodinium). We compared the lipid content and fatty acid profiles of the host cellular layers, non-symbiotic epidermal and symbiont-containing gastrodermal cells, and those of Symbiodinium, in a mass spectrometry-based assessment. Lipids were more concentrated in Symbiodinium cells, and the lipid class distribution was dominated by polar lipids in all tissues. The fatty acid distribution between host cell layers and Symbiodinium cells suggested potential lipid transfers between the partners. The lipid composition and distribution was modified during short-term hyperthermal stress, mainly in Symbiodinium cells and gastrodermis. Exposure to elevated temperature rapidly caused a decrease in polar lipid C18 unsaturated fatty acids and a strong and rapid decrease in the abundance of polar lipid fatty acids relative to sterols. These lipid indicators could therefore be used as sensitive biomarkers to assess the physiology of symbiotic cnidarians, especially the effect of thermal stress at the onset of cnidarian bleaching. Overall, the findings of this study provide some insight on key lipids that may regulate maintenance of the symbiotic interaction.

  5. Traditional medicine, Sobokchukeo-Tang, modulates the inflammatory response in adipocytes and macrophages

    PubMed Central

    Lee, Hoyoung; Shim, Eun Hyoung; Lee, Myeong Soo; Myung, Chang-Seon

    2016-01-01

    Sobokchukeo-Tang (ST) is a well-known formula that is used for treating primary dysmenorrhea caused by blood stasis syndrome (BSS) in Korea and China. The current study investigated the anti-inflammatory and anti-adipogenesis effects of ST on adipocytes and macrophages. The anti-inflammatory efficacy of ST was evaluated in RAW 264.7 cells and differentiated THP-1 cells. To induce inflammation, the cells were treated with lipopolysaccharide (LPS; 1 µg/ml). Following the induction of inflammation, the levels of proinflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the cell supernatant were detected using enzyme-linked immunosorbent assay. 3T3-L1 preadipocytes differentiated into adipocytes in response to insulin, isobutyl-1-methylxanthine and dexamethasone (MDI). To confirm the anti-adipogenesis efficacy of ST, we investigated Oil Red O staining was performed, triglyceride (TG) and leptin secretion were measured, and the protein expression of lipid metabolism-associated factors was determined. ST significantly inhibited TNF-α and IL-6 production in the LPS-treated RAW 264.7 cells compared with LPS stimulation alone. In addition, the concentrations of IL-6 and TNF-α were significantly inhibited by ST in LPS-treated THP-1 cells. Lipid accumulation was reduced by ST, similarly to the positive control treatment, SB203580. In the ST-treated group, the TG and leptin concentrations were inhibited by up to 50 and 83%, respectively, compared with MDI induction only. The ST-treated group reduced the protein expression of peroxisome proliferator-activated receptor-γ and CCAAT/enhancer-binding protein α compared with MDI induction only. The results of the present study demonstrated that ST exerts anti-inflammatory effects on LPS-treated mouse and human macrophage cell lines. ST inhibited adipogenesis in MDI-induced 3T3-L1 adipocytes, as indicated by the significant reduction in TG and leptin concentrations without cytotoxicity. Thus, ST

  6. Glucocorticoids increase adipocytes in muscle by affecting IL-4 regulated FAP activity

    PubMed Central

    Dong, Yanjun; Silva, Kleiton Augusto Santos; Dong, Yanlan; Zhang, Liping

    2014-01-01

    An increase in intramuscular adipocyte tissue (IMAT) is associated with glucose dysregulation, decreased muscle strength, and increased risk of disability. Unfortunately, the mechanisms stimulating intramuscular adipogenesis remain unclear. We found that dexamethasone (Dex) administration to mice with injured muscles stimulates the accumulation of IMAT. To identify precursors of these adipocytes, we isolated satellite cells and fibro/adipogenic progenitors (FAPs) from muscle; satellite cells did not differentiate into adipocytes even following Dex treatment. In contrast, Dex stimulated FAP differentiation into adipocytes. In vivo, we transplanted purified FAPs from transgenic, EGFP mice into the injured muscles of C57/BL6 mice and found that Dex administration stimulated adipogenesis from FAP-EGFP. The increase in adipogenesis depended on Dex-induced inhibition of interleukin-4 (IL-4). In the injured muscle of IL-4-knockout mice, the levels of adipocytes were increased, while in the injured muscles of Dex-treated mice with IL-4 injections, adipogenesis was suppressed. In cultured FAPs, IL-4 inhibited Dex-induced conversion of FAPs into adipocytes; this did not occur in FAPs expressing knockdown of the IL-4 receptor. Thus, we concluded that glucocorticoids stimulate FAPs to differentiate into adipocytes in injured muscles. This process is blocked by IL-4, suggesting that interfering with IL-4 signaling could prevent adipogenesis in muscle.—Dong, Y., Silva, K. A. S., Dong, Y., Zhang, L. Glucocorticoids increase adipocytes in muscle by affecting IL-4 regulated FAP activity. PMID:24948596

  7. Tetraether bolaform amphiphiles as models of archaebacterial membrane lipids: Synthesis, differential scanning calorimetry, and monolayer studies

    SciTech Connect

    Kim, J.M.; Thompson, D.H. )

    1992-02-01

    Four racemic tetraether lipids containing a single 1,[omega]-polymethylene chain ([omega] = 16, 20) bridging two glycerophosphate headgroups (bolaform amphiphiles) have been synthesized. These materials have been characterized at the air-water interface by monolayer balance methods and in buffered solution by differential scanning calorimetry (DSC) and negative stain transmission electron microscopy (TEM). Molecular areas in excess of 100 [angstrom][sup 2]/molecule at 40 mN/m[sup 2] were observed for all bolaamphiphiles studied, suggesting a U-shaped molecular conformation that places both phosphate headgroups in the water subphase. Aqueous dispersions of these lipids have thermal and morphological properties that depend on molecular structure and solution pH. Phase transition temperatures (T[sub c]) of the structural isomers, 2,2[prime]-di-O-decyl-1, 1[prime]-O-eicosamethylene-rac-diglycero-3,3[prime]-diphosphate (PS20) and 1,1[prime]-di-O-decyl-2,2[prime]-O-eicosamethylene-3,3[prime]-diphosphate (SS20), were 49 and 38 [degrees]C, respectively, at pH 2.5. A reduction in the observed T[sub c] of [approximately] 14 [degrees]C occurred when the pH was raised to 8.1. The closely related structural analogue, 1,1[prime]-O-eicosamethylene-2-O-eicosyl-rac-diglycero-3,2[prime], 3[prime]-diphosphate (PA20), has a T[sub c] 85 [degrees]C. No phase transition was observed above 5 [degrees]C for 2,2[prime]-O-dioctyl-1,1 [prime]-O-hexadecylmethylene-rac-diglycero-3, 3[prime]-disphosphoric acid (PS16). Multilamellar structures with hydrocarbon-region spacings of 24-30 [angstrom] and overall lengths approaching 0.3 [mu]m were observed by negative stain electron microscopy. The observed lamellae distance is in good agreement with the membrane thickness expected for a bolaamphiphile in its all-anti conformation. 56 refs., 8 figs., 1 tab.

  8. Peroxisome Proliferator-activated Receptor γ Regulates Genes Involved in Insulin/Insulin-like Growth Factor Signaling and Lipid Metabolism during Adipogenesis through Functionally Distinct Enhancer Classes*

    PubMed Central

    Oger, Frédérik; Dubois-Chevalier, Julie; Gheeraert, Céline; Avner, Stéphane; Durand, Emmanuelle; Froguel, Philippe; Salbert, Gilles; Staels, Bart; Lefebvre, Philippe; Eeckhoute, Jérôme

    2014-01-01

    The nuclear receptor peroxisome proliferator-activated receptor (PPAR) γ is a transcription factor whose expression is induced during adipogenesis and that is required for the acquisition and control of mature adipocyte functions. Indeed, PPARγ induces the expression of genes involved in lipid synthesis and storage through enhancers activated during adipocyte differentiation. Here, we show that PPARγ also binds to enhancers already active in preadipocytes as evidenced by an active chromatin state including lower DNA methylation levels despite higher CpG content. These constitutive enhancers are linked to genes involved in the insulin/insulin-like growth factor signaling pathway that are transcriptionally induced during adipogenesis but to a lower extent than lipid metabolism genes, because of stronger basal expression levels in preadipocytes. This is consistent with the sequential involvement of hormonal sensitivity and lipid handling during adipocyte maturation and correlates with the chromatin structure dynamics at constitutive and activated enhancers. Interestingly, constitutive enhancers are evolutionary conserved and can be activated in other tissues, in contrast to enhancers controlling lipid handling genes whose activation is more restricted to adipocytes. Thus, PPARγ utilizes both broadly active and cell type-specific enhancers to modulate the dynamic range of activation of genes involved in the adipogenic process. PMID:24288131