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  1. Differentiation of preadipocytes and mature adipocytes requires PSMB8

    Hideki Arimochi; Yuki Sasaki; Akiko Kitamura; Koji Yasutomo

    2016-01-01

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

  2. Differentiation of preadipocytes and mature adipocytes requires PSMB8.

    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

  3. Adipocyte differentiation and leptin expression

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

    1997-01-01

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

  4. Estrogen Sulfotransferase Inhibits Adipocyte Differentiation

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

    2011-01-01

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

  5. Cyclic AMP (cAMP)-mediated stimulation of adipocyte differentiation requires the synergistic action of Epac- and cAMP-dependent protein kinase-dependent processes

    Petersen, Rasmus Koefoed; Madsen, Lise; Pedersen, Lone Møller;

    2008-01-01

    Cyclic AMP (cAMP)-dependent processes are pivotal during the early stages of adipocyte differentiation. We show that exchange protein directly activated by cAMP (Epac), which functions as a guanine nucleotide exchange factor for the Ras-like GTPases Rap1 and Rap2, was required for c...

  6. PPARgamma in adipocyte differentiation and metabolism

    Siersbaek, Rasmus; Nielsen, Ronni; Mandrup, Susanne

    2010-01-01

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

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

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

    2014-06-01

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

  8. Dynamics of protein secretion during adipocyte differentiation.

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

    2016-08-01

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

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

    Aileen Balkow

    2015-08-01

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

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

    Huang Hai-Yan

    2010-05-01

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

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

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

    2015-09-10

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

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

    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.

  13. Adipocyte Induction of Preadipocyte Differentiation in a Gradient Chamber

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

    2012-01-01

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

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

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

  15. Differentiation of Pre-Adipocytes in Modelled Microgravity

    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.

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

    Ignazio eBarbagallo

    2016-01-01

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

  17. Differential Chemokine Signature between Human Preadipocytes and Adipocytes.

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

    2016-06-01

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

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

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

    2013-01-01

    Phytoestrogens (PEs) are naturally occurring plant components, with the ability to induce biological responses in vertebrates by mimicking or modulating the action of endogenous hormones.Single isoflavones have been shown to affect adipocyte differentiation, but knowledge on the effect of dietary...

  19. Chromium propionate enhances adipogenic differentiation of bovine intramuscular adipocytes

    Rebecca eTokach

    2015-09-01

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

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

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

    2012-01-01

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

  1. Transcriptional activation of peroxisome proliferator-activated receptor-γ requires activation of both protein kinase A and Akt during adipocyte differentiation

    Research highlights: → Elevated cAMP activates both PKA and Epac. → PKA activates CREB transcriptional factor and Epac activates PI3K/Akt pathway via Rap1. → Akt modulates PPAR-γ transcriptional activity in concert with CREB. -- Abstract: Peroxisome proliferator-activated receptor-γ (PPAR-γ) is required for the conversion of pre-adipocytes. However, the mechanism underlying activation of PPAR-γ is unclear. Here we showed that cAMP-induced activation of protein kinase A (PKA) and Akt is essential for the transcriptional activation of PPAR-γ. 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-γ was markedly enhanced by 3-isobutyl-1-methylxanthine (IBMX), but not insulin and dexamethasone. In addition, IBMX-induced PPAR-γ 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-γ transcriptional activity. These results indicate that both PKA and Akt signaling pathways are required for transcriptional activation of PPAR-γ, suggesting post-translational activation of PPAR-γ might be critical step for adipogenic gene expression.

  2. Transcriptional activation of peroxisome proliferator-activated receptor-{gamma} requires activation of both protein kinase A and Akt during adipocyte differentiation

    Kim, Sang-pil [Department of Thoracic and Cardiovascular Surgery, Pusan National University School of Medicine (Korea, Republic of); Ha, Jung Min; Yun, Sung Ji; Kim, Eun Kyoung [MRC for Ischemic Tissue Regeneration, Medical Research Institute, and Department of Pharmacology, Pusan National University School of Medicine (Korea, Republic of); Chung, Sung Woon [Department of Thoracic and Cardiovascular Surgery, Pusan National University School of Medicine (Korea, Republic of); Hong, Ki Whan; Kim, Chi Dae [MRC for Ischemic Tissue Regeneration, Medical Research Institute, and Department of Pharmacology, Pusan National University School of Medicine (Korea, Republic of); Bae, Sun Sik, E-mail: sunsik@pusan.ac.kr [MRC for Ischemic Tissue Regeneration, Medical Research Institute, and Department of Pharmacology, Pusan National University School of Medicine (Korea, Republic of)

    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.

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

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

    1991-01-01

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

  4. Regulatory circuits controlling white versus brown adipocyte differentiation

    Hansen, Jacob B; Kristiansen, Karsten

    2006-01-01

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

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

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

    2016-01-01

    Silibinin, a natural plant flavonolignan is the main active constituent found in milk thistle (Silybum marianum). It is known to have hepatoprotective, anti-neoplastic effect, and suppresses lipid accumulation in adipocytes. Objective of this study was to investigate the effect of silibinin on adipogenic differentiation and thermogenic capacity of human adipose tissue derived mesenchymal stem cells. Silibinin (10 μM) treatment, either at the beginning or at the end of adipogenic differentiati...

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

    Xiuquan eMa

    2015-01-01

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

  7. ATF3 represses PPARγ expression and inhibits adipocyte differentiation

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

    2014-11-07

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

  8. γ-Oryzanol Enhances Adipocyte Differentiation and Glucose Uptake

    Chang Hwa Jung

    2015-06-01

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

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

    Qiaoli Gu

    2012-01-01

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

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

    Yang An

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

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

    Ninomiya, Yuichi [Translational Research Center, Saitama International Medical, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 (Japan); Sugahara-Yamashita, Yzumi; Nakachi, Yutaka; Tokuzawa, Yoshimi; Okazaki, Yasushi [Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama 350-1241 (Japan); Nishiyama, Masahiko, E-mail: yamacho@saitama-med.ac.jp [Translational Research Center, Saitama International Medical, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 (Japan)

    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.

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

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

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

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

    2010-01-01

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

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

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

    2016-09-01

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

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

    Prawitt, Janne; Niemeier, Andreas; Kassem, Moustapha;

    2008-01-01

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

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

    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.

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

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

    2016-03-01

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

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

    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. PMID:21031614

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

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

    2016-04-01

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

  20. Pathologic endoplasmic reticulum stress induced by glucotoxic insults inhibits adipocyte differentiation and induces an inflammatory phenotype.

    Longo, Michele; Spinelli, Rosa; D'Esposito, Vittoria; Zatterale, Federica; Fiory, Francesca; Nigro, Cecilia; Raciti, Gregory A; Miele, Claudia; Formisano, Pietro; Beguinot, Francesco; Di Jeso, Bruno

    2016-06-01

    Adipocyte differentiation is critical in obesity. By controlling new adipocyte recruitment, adipogenesis contrasts adipocyte hypertrophy and its adverse consequences, such as insulin resistance. Contrasting data are present in literature on the effect of endoplasmic reticulum (ER) stress and subsequent unfolded protein response (UPR) on adipocyte differentiation, being reported to be either necessary or inhibitory. In this study, we sought to clarify the effect of ER stress and UPR on adipocyte differentiation. We have used two different cell lines, the widely used pre-adipocyte 3T3-L1 cells and a murine multipotent mesenchymal cell line, W20-17 cells. A strong ER stress activator, thapsigargin, and a pathologically relevant inducer of ER stress, glucosamine (GlcN), induced ER stress and UPR above those occurring in the absence of perturbation and inhibited adipocyte differentiation. Very low concentrations of 4-phenyl butyric acid (PBA, a chemical chaperone) inhibited only the overactivation of ER stress and UPR elicited by GlcN, leaving unaltered the part physiologically activated during differentiation, and reversed the inhibitory effect of GlcN on differentiation. In addition, GlcN stimulated proinflammatory cytokine release and PBA prevented these effects. An inhibitor of NF-kB also reversed the effects of GlcN on cytokine release. These results indicate that while ER stress and UPR activation is "physiologically" activated during adipocyte differentiation, the "pathologic" part of ER stress activation, secondary to a glucotoxic insult, inhibits differentiation. In addition, such a metabolic insult, causes a shift of the preadipocyte/adipocyte population towards a proinflammatory phenotype. PMID:26940722

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

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

    2004-01-01

    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....

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

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

    2004-01-01

    Adipocyte precursor cells give raise to two major cell populations with different physiological roles: white and brown adipocytes. Here we demonstrate that the retinoblastoma protein (pRB) regulates white vs. brown adipocyte differentiation. Functional inactivation of pRB in wild-type mouse embryo...... fibroblasts (MEFs) and white preadipocytes by expression of simian virus 40 large T antigen results in the expression of the brown fat-specific uncoupling protein 1 (UCP-1) in the adipose state. Retinoblastoma gene-deficient (Rb-/-) MEFs and stem cells, but not the corresponding wild-type cells, differentiate...

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

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

    2016-01-01

    The highly regulated differentiation and proliferation of pre-adipocytes play a key role in the initiation of obesity. Fat mass and obesity associated (FTO) is a novel gene strongly associated with the risk of obesity. A deficiency of FTO may cause growth retardation in addition to fat mass and adipocyte size reduction in vivo. To investigate the potential role of Fto gene on the proliferation and differentiation of pre-adipocytes, we generated Fto-knockdown and overexpressed 3T3-L1 cells. Us...

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

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

  5. DYNAMICS OF LIPID DROPLET-ASSOCIATED PROTEINS DURING HORMONALLY STIMULATED LIPOLYSIS IN ENGINEERED ADIPOCYTES: STABILIZATION AND LIPID DROPLET BINDING OF ADIPOCYTE DIFFERENTIATION-RELATED PROTEIN/ADIPOPHILIN

    In mature adipocytes, triglyceride is stored within lipid droplets, which are coated with the protein perilipin, which functions to regulate lipolysis by controlling lipase access to the droplet in a hormone-regulatable fashion. Adipocyte-differentiation related protein (ADRP) is a widely expressed ...

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

    Nerurkar Vivek R

    2010-06-01

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

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

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

    2015-01-01

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

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

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

    2009-01-01

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

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

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

    2009-01-01

    In mammals, adipose tissue, composed of BAT and WAT, collaborates in energy partitioning and performs metabolic regulatory functions. It is the most flexible tissue in the body, because it is remodeled in size and shape by modifications in adipocyte cell size and/or number, depending on developmental status and energy fluxes. Although numerous reviews have focused on the differentiation program of both brown and white adipocytes as well as on the pathophysiological role of white adipose tissu...

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

    Cinti, Saverio

    2011-03-01

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

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

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

    2016-01-01

    Adipose tissue plays important roles in regulating carbohydrate and lipid homeostasis, but less is known about the regulation of amino acid metabolism in adipocytes. Here we applied isotope tracing to pre-adipocytes and differentiated adipocytes to quantify the contributions of different substrates to tricarboxylic acid (TCA) metabolism and lipogenesis. In contrast to proliferating cells, which use glucose and glutamine for acetyl-coenzyme A (AcCoA) generation, differentiated adipocytes showed increased branched-chain amino acid (BCAA) catabolic flux such that leucine and isoleucine from medium and/or from protein catabolism accounted for as much as 30% of lipogenic AcCoA pools. Medium cobalamin deficiency caused methylmalonic acid accumulation and odd-chain fatty acid synthesis. Vitamin B12 supplementation reduced these metabolites and altered the balance of substrates entering mitochondria. Finally, inhibition of BCAA catabolism compromised adipogenesis. These results quantitatively highlight the contribution of BCAAs to adipocyte metabolism and suggest that BCAA catabolism has a functional role in adipocyte differentiation. PMID:26571352

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

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

    2003-01-01

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

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

    Du, Jingjing; Cheng, Xiao; Shen, Linyuan; Tan, Zhendong; Luo, Jia; Wu, Xiaoqian; Liu, Chendong; Yang, Qiong; Jiang, Yanzhi; Tang, Guoqing; Li, Xuewei; Zhang, Shunhua; Zhu, Li

    2016-06-17

    MicroRNAs (miRNAs, miR) play important roles in adipocyte development. Recent studies showed that the expression of several miRNAs is closely related with promoter methylation. However, it is not known whether miRNA mediates adipocytes differentiation by means of DNA methylation. Here, we showed that miR-145a-5p was poorly expressed in adipose tissue from mice fed a high fat diet (HFD). Overexpression or inhibition of miR-145a-5p was unfavorable or beneficial, respectively, for adipogenesis, and these effects were achieved by regulating adipocyte-specific genes involved in lipogenic transcription, fatty acid synthesis, and fatty acid transportation. Particularly, we first suggested that miR-145a-5p mimics or inhibitors promoted or repressed adipocytes proliferation by regulating p53 and p21, which act as cell cycle regulating factors. Surprisingly, the miR-145a-5p-repressed adipocyte differentiation was enhanced or rescued when cells treated with 5-Aza-dC were transfected with miR-145a-5p mimics or inhibitors, respectively. These data indicated that, as a new mean to positively regulate adipocyte proliferation, the process of miR-145a-5p-inhibited adipogenesis may be regulated by DNA methylation. PMID:27179777

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

    Joram D Mul

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

  15. Mammalian ste20-like kinase and SAV1 promote 3T3-L1 adipocyte differentiation by activation of PPARγ.

    Byoung Hee Park

    Full Text Available The mammalian ste20 kinase (MST signaling pathway plays an important role in the regulation of apoptosis and cell cycle control. We sought to understand the role of MST2 kinase and Salvador homolog 1 (SAV1, a scaffolding protein that functions in the MST pathway, in adipocyte differentiation. MST2 and MST1 stimulated the binding of SAV1 to peroxisome proliferator-activated receptor γ (PPARγ, a transcription factor that plays a key role in adipogenesis. The interaction of endogenous SAV1 and PPARγ was detected in differentiating 3T3-L1 adipocytes. This binding required the kinase activity of MST2 and was mediated by the WW domains of SAV1 and the PPYY motif of PPARγ. Overexpression of MST2 and SAV1 increased PPARγ levels by stabilizing the protein, and the knockdown of SAV1 resulted in a decrease of endogenous PPARγ protein in 3T3-L1 adipocytes. During the differentiation of 3T3-L1 cells into adipocytes, MST2 and SAV1 expression began to increase at 2 days when PPARγ expression also begins to increase. MST2 and SAV1 significantly increased PPARγ transactivation, and SAV1 was shown to be required for the activation of PPARγ by rosiglitazone. Finally, differentiation of 3T3-L1 cells was augmented by MST2 and SAV1 expression and inhibited by knockdown of MST1/2 or SAV1. These results suggest that PPARγ activation by the MST signaling pathway may be a novel regulatory mechanism of adipogenesis.

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

    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.

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

    Hao, Chan-Juan; Cheng, Xue-Jia; Xia, Hong-Fei, E-mail: hongfeixia@yahoo.com.cn; Ma, Xu

    2012-08-15

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

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

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

    2013-01-15

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

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

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

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

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

    2015-05-08

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

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

    Hyoung Joon Park

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

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

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

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

    Jang, Min Kyung; Kim, Cho Hee [School of Korean Medicine, Pusan National University, 30 Beom-eo ri, Mulguem-eup, Yangsan-si, Gyeongnam 609-735 (Korea, Republic of); Seong, Je Kyung [Department of Anatomy and Cell Biology, College of Veterinary Medicine, Seoul National University, Seoul 151-742 (Korea, Republic of); Jung, Myeong Ho, E-mail: jung0603@pusan.ac.kr [School of Korean Medicine, Pusan National University, 30 Beom-eo ri, Mulguem-eup, Yangsan-si, Gyeongnam 609-735 (Korea, Republic of)

    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

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

    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

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

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

    2013-03-01

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

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

    Vaishali I. Parekh

    2015-01-01

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

  7. Sclerostin Enhances Adipocyte Differentiation in 3T3-L1 Cells.

    Ukita, Mayumi; Yamaguchi, Taihiko; Ohata, Noboru; Tamura, Masato

    2016-06-01

    Sclerostin, a secreted protein encoded by the Sost gene, is produced by osteocytes and is inhibited by osteoblast differentiation and bone formation. Recently, a functional association between bone and fat tissue has been suggested, and a correlation between circulating sclerostin levels and lipid metabolism has been reported in humans. However, the effects of sclerostin on adipogenesis remain unexplored. In the present study, we examined the role of sclerostin in regulating adipocyte differentiation using 3T3-L1 preadipocytes. In these cells, sclerostin enhanced adipocyte-specific gene expression and the accumulation of lipid deposits. Sclerostin also upregulated CCAAT/enhancer binding protein β expression but not cell proliferation and caspase-3/7 activities. Sclerostin also attenuated canonical Wnt3a-inhibited adipocyte differentiation. Recently, the transcriptional modulator TAZ has been involved in the canonical Wnt signaling pathway. Sclerostin reduced TAZ-responsive transcriptional activity and TAZ-responsive gene expression. Transfection of 3T3-L1 cells with TAZ siRNA increased the lipid deposits and adipogenic gene expression. These results show that sclerostin upregulates adipocyte differentiation in 3T3-L1 cells, suggesting a possible role for the osteocyte-derived sclerostin as a regulator of fat metabolism and as a reciprocal regulator of bone and adipose tissues metabolism. J. Cell. Biochem. 117: 1419-1428, 2016. © 2015 Wiley Periodicals, Inc. PMID:26553151

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

    Hamam, D; Ali, D; Vishnubalaji, R;

    2014-01-01

    -mediated stable expression of miR-320c at physiological levels (~1.5-fold) promoted adipocytic and suppressed osteogenic differentiation of hMSC. Luciferase assay validated RUNX2 (Runt-related transcription factor 2) as a bona fide target for miR-320 family. Therefore, our data suggest miR-320 family as possible...

  9. Epidermis-type lipoxygenase 3 regulates adipocyte differentiation and peroxisome proliferator-activated receptor gamma activity

    Hallenborg, Philip; Jørgensen, Claus; Petersen, Rasmus K;

    2010-01-01

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

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

    Fajas, Lluis; Egler, Viviane; Reiter, Raphael;

    2002-01-01

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

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

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

    2009-01-01

    The adipose tissue has important secretory and endocrine functions in humans. The regulation of adipocyte differentiation has been actively pursued using transcriptomic methods over the last several years. Quantitative proteomics has emerged as a promising approach to obtain temporal profiles of ...

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

    Kumaratilake Jaliya S

    2008-04-01

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

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

    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 γ (PPARγ) targets and PPARγ itself, however, nobiletin did not exhibit PPARγ ligand activity. We observed the expression of CCAAT/enhancer binding protein β (C/EBPβ), a transcription factor for PPARγ, 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/EBPβ 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

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

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

    2016-09-01

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

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

    Yeon-Ju Park; Mi-Seong Kim; Ha-Rim Kim; Jeong-Mi Kim; Jin-Ki Hwang; Sei-Hoon Yang; Hye-Jung Kim; Dong-Sung Lee; Hyuncheol Oh; Youn-Chul Kim; Do-Gon Ryu; Young-Rae Lee; Kang-Beom Kwon

    2014-01-01

    The rhizome of Alisma orientale (Alismatis rhizome) has been used in Asia for promoting diuresis to eliminate dampness from the lower-jiao and to expel heat. In this study, an ethanol extract of the rhizome of Alisma orientale (AOE) was prepared and its effects on adipocyte differentiation of OP9 cells were investigated. Treatment with AOE in a differentiation medium for 5 days resulted in dose-dependent inhibition of lipid droplet formation in OP9 cells. Furthermore, AOE significantly inhibi...

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

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

    2011-03-25

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

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

    Research highlights: → In this study, we investigated the effects of leptin on adipocyte differentiation prepared from subcutaneous fat of TallyHo mice. → Leptin inhibited the adipocytes differentiation at physiological concentration via inhibition of PPARγ expression. → 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 γ (PPARγ) 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 PPARγ expression in the subcutaneous fat of TallyHO mice. These data suggest that leptin could inhibit the PPARγ expression and adipocyte differentiation in its physiological concentration in TallyHO mice.

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

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

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

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

    2008-01-01

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

  20. 7-Chloroarctinone-b as a new selective PPARγ antagonist potently blocks adipocyte differentiation

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

    2009-01-01

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

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

    Yang Jiao

    2016-02-01

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

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

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

    2016-02-01

    The highly regulated differentiation and proliferation of pre-adipocytes play a key role in the initiation of obesity. Fat mass and obesity associated (FTO) is a novel gene strongly associated with the risk of obesity. A deficiency of FTO may cause growth retardation in addition to fat mass and adipocyte size reduction in vivo. To investigate the potential role of Fto gene on the proliferation and differentiation of pre-adipocytes, we generated Fto-knockdown and overexpressed 3T3-L1 cells. 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. PMID:26907332

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

    Ekambaram, Padmini; Parasuraman, Parimala; Jayachandran, Tharani

    2016-06-01

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

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

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

    2002-01-01

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

  5. Anthraquinones from Morinda officinalis roots enhance adipocyte differentiation in 3T3-L1 cells.

    Liu, Qing; Kim, Seon Beom; Ahn, Jong Hoon; Hwang, Bang Yeon; Kim, Sung Yeon; Lee, Mi Kyeong

    2012-01-01

    To search for anti-diabetic and insulin-sensitising natural products, the effect on adipocyte differentiation was investigated by assessing fat accumulation in 3T3-L1 preadipocytes using Oil Red O staining. Fractionation and separation of n-hexane and CHCl₃ fractions of Morinda officinalis (Rubiaceae) using several chromatographic methods led to the isolation of three anthraquinones, 1,2-dimethoxyanthraquinone (1), alizarin-2-methyl ether (2) and rubiadin-1-methyl ether (3). Among them, alizarin-2-methyl ether (2) showed the strongest enhancing activity, followed by rubiadin-1-methyl ether (3) and 1,2-dimethoxyanthraquinone (1). At a concentration of 100 µM, alizarin-2-methyl ether (2) enhanced adipocyte differentiation by up to 131% (compared to insulin-treated cells). Thus, these compounds could be beneficial in the treatment of diabetes. PMID:22008000

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

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

    2013-01-01

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

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

    Lu Sumei

    2012-01-01

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

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

    Floriana Forzati

    2014-09-01

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

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

    Forzati, Floriana; Federico, Antonella; Pallante, Pierlorenzo; Colamaio, Marianna; Esposito, Francesco; Sepe, Romina; Gargiulo, Sara; Luciano, Antonio; Arra, Claudio; Palma, Giuseppe; Bon, Giulia; Bucher, Stefania; Falcioni, Rita; Brunetti, Arturo; Battista, Sabrina; Fedele, Monica; Fusco, Alfredo

    2014-01-01

    We have recently generated knockout mice for the Cbx7 gene, coding for a polycomb group protein that is downregulated in human malignant neoplasias. These mice develop liver and lung adenomas and carcinomas, which confirms a tumour suppressor role for CBX7. The CBX7 ability to downregulate CCNE1 expression likely accounts for the phenotype of the Cbx7-null mice. Unexpectedly, Cbx7-knockout mice had a higher fat tissue mass than wild-type, suggesting a role of CBX7 in adipogenesis. Consistently, we demonstrate that Cbx7-null mouse embryonic fibroblasts go towards adipocyte differentiation more efficiently than their wild-type counterparts, and this effect is Cbx7 dose-dependent. Similar results were obtained when Cbx7-null embryonic stem cells were induced to differentiate into adipocytes. Conversely, mouse embryonic fibroblasts and human adipose-derived stem cells overexpressing CBX7 show an opposite behaviour. These findings support a negative role of CBX7 in the control of adipocyte cell growth and differentiation. PMID:25190058

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

    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. PMID:9624148

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

    Ali Mohammad Sharifi

    2012-01-01

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

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

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

    2014-01-01

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

  13. Lactacystin inhibits 3T3-L1 adipocyte differentiation through induction of CHOP-10 expression

    Hormonal induction triggers a cascade leading to the expression of CCAAT/enhancer-binding protein(C/EBP)α and peroxisome proliferator-activated receptor (PPAR) γ, C/EBPα, and PPARγ turns on series of adipocyte genes that give rise to the adipocyte phenotype. Previous findings indicate that C/EBPβ, a transcriptional activator of the C/EBPα and PPARγ genes, is rapidly expressed after induction, but lacks DNA-binding activity and therefore cannot activate transcription of the C/EBPα and PPARγ genes early in the differentiation program. Acquisition of DNA-binding activity of C/EBPβ occurs when CHOP-10, a dominant-negative form of C/EBP family members, is down-regulated and becomes hyperphosphorylated as preadipocytes traverse the G1-S checkpoint of mitotic clonal expansion. Evidences are presented in this report that lactacystin, a proteasome inhibitor, up-regulated the CHOP-10 expression, blocked the DNA-binding activity of C/EBPβ, and subsequently inhibited MCE as well as adipocyte differentiation

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

    1991-01-01

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

  15. Antiadipogenic properties of retinol in primary cultured differentiating human adipocyte precursor cells.

    Garcia, E; Lacasa, D; Agli, B; Giudicelli, Y; Castelli, D

    2000-04-01

    The aim of this study was to investigate the effect of retinol on the human adipose conversion process using primary cultured human adipocyte precursor cells. When these cells were seeded in a medium containing retinol (concentrations ranging from 3.5 nM to 3.5 muM), cell proliferation was slightly inhibited by high concentrations of retinol, as demonstrated by cell counting and [(3)H]-thymidine incorporation. Moreover, the differentiation capacities of these cells were markedly and dose-dependently inhibited by retinol, as shown by the reduced expression of the lipogenic enzyme glycerol-3-phosphate dehydrogenase and by microscopic morphological analysis. These results strongly suggest that retinol, by inhibiting the ability of human preadipocytes to convert into mature adipocytes, could be of potential interest in the prevention of human adipose tissue development in general and of cellulitis in particular. PMID:18503465

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

    Juan Zhang

    Full Text Available 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/EBPα, 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. Re-expression of GATA2 Cooperates with Peroxisome Proliferator-activated Receptor-γ Depletion to Revert the Adipocyte Phenotype*S⃞

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

    2009-01-01

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

  18. Differentiation of human adipocytes at physiological oxygen levels results in increased adiponectin secretion and isoproterenol-stimulated lipolysis

    Famulla, Susanne; Schlich, Raphaela; Sell, Henrike; Eckel, Jürgen

    2012-01-01

    Adipose tissue (AT) hypoxia occurs in obese humans and mice. Acute hypoxia in adipocytes causes dysregulation of adipokine secretion with an increase in inflammatory factors and diminished adiponectin release. O2 levels in humans range between 3 and 11% revealing that conventional in vitro culturing at ambient air and acute hypoxia treatment (1% O2) are performed under non-physiological conditions. In this study, we mimicked physiological conditions by differentiating human primary adipocytes...

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

    Watanabe, Akio, E-mail: watanabea@jfrl.or.jp [Japan Food Research Laboratories, Osaka 567-0085 (Japan); Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Miyagi 981-8555 (Japan); Kato, Tsuyoshi; Ito, Yusuke; Yoshida, Izumi; Harada, Teppei; Mishima, Takashi; Fujita, Kazuhiro; Watai, Masatoshi [Japan Food Research Laboratories, Osaka 567-0085 (Japan); Nakagawa, Kiyotaka; Miyazawa, Teruo [Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Miyagi 981-8555 (Japan)

    2014-10-31

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

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

    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

  1. Myristic Acid (MA) Promotes Adipogenic Gene Expression and the Differentiation of Porcine Intramuscular Adipocyte Precursor Cells

    LU Nai-sheng; ZHANG Yong-liang; JIANG Qing-yan; SHU Gang; XIE Qiu-ping; ZHU Xiao-tong; GAO Ping; ZHOU Gui-xuan; WANG Song-bo; WANG Li-na; XI Qian-yun

    2014-01-01

    Intramuscular fat (IMF) content is considered to be a key factor that affects the marbling, tenderness, juiciness and lfavor of pork. To investigate the effects of myristic acid (MA) on the differentiation of porcine intramuscular adipocytes, cells were isolated from longissimus dorsi muscle (LDM) and treated with 0, 10, 50 or 100μmol L-1 MA. The results showed that MA signiifcantly promotes the differentiation of intramuscular adipocytes in a dose-dependent manner. MA also led to a parallel increase in the expression of peroxisome proliferator activated receptor-γ(PPARγ) and adipose-related genes, such as glucose transporter 1 (GLUT1), lipoprotein lipase (LPL), adipocyte fatty acid binding protein 4 (FABP4/aP2), fatty acid translocase (FAT), acetyl-CoA carboxylaseα(ACCα), adipose triglyceride lipase (ATGL) and fatty acid synthase (FASN). However, no signiifcant effects of MA were observed on the expression of CAAT enhancer binding protein-α(C/EBPα) or hormone sensitive lipase (HSL). The expression of pyruvate dehydrogenase kinase 4 (PDK4) was increased by MA during the early stages of differentiation (day 1-3). In addition, MA also increased the absolute content of C14 (P<0.001) and saturated fatty acids (SFA) (P<0.05) to varying degrees, but no effects were observed on other fatty acids. These results suggest that MA might be able to enhance the IMF content of pork and increase the accumulation of myristic and myristoleic acid in muscle, which might have beneifcial implications for human health.

  2. Inhibition of Wnt/β-catenin signaling by dexamethasone promotes adipocyte differentiation in mesenchymal progenitor cells, ROB-C26.

    Naito, Masako; Omoteyama, Kazuki; Mikami, Yoshikazu; Takahashi, Tomihisa; Takagi, Minoru

    2012-12-01

    Dexamethasone (Dex) stimulates the differentiation of mesenchymal progenitor cells into adipocytes and osteoblasts. However, the mechanisms underlying Dex-induced differentiation have not been clearly elucidated. We examined the effect of Dex on the expression and activity of Wnt/β-catenin signal-related molecules in a clonal mesenchymal progenitor cell line, ROB-C26 (C26). Dex induced the mRNA expression of Wnt antagonists, dickkopf-1 (Dkk-1), and Wnt inhibitory factor (WIF)-1. Immunocytochemical analysis showed that the downregulation of β-catenin protein expression by Dex occured concomitantly with the increased expression of the PPARγ protein. Dex decreased phosphorylation of Ser9-GSK3β and expression of active β-catenin protein. To examine the effects of Dex on Wnt/β-catenin activity, we used immunocytochemistry to analyze TCF/LEF-mediated transcription during Dex-induced adipogenesis in Wnt indicator (TOPEGFP) C26 cells. Our results demonstrated that Dex repressed TCF/LEF-mediated transcription, but induced adipocyte differentiation. Treatment with a GSK3β inhibitor attenuated Dex-induced inhibition of TCF/LEF-mediated transcriptional activity, but suppressed Dex-induced adipocyte differentiation, indicating that adipocyte differentiation and inhibition of Wnt/β-catenin activity by Dex are mediated by GSK3β activity. Furthermore, β-catenin knockdown not only suppressed Dex-induced ALP-positive osteoblasts differentiation but also promoted Dex-induced adipocytes differentiation. These results suggest that inhibition of β-catenin expression by Dex promotes the differentiation of mesenchymal progenitor cells into adipocytes. PMID:22886144

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

    Fürstenberger, Gerhard; Epp, Nikolas; Eckl, Katja-Martina; Hennies, Hans Christian; Hallenborg, Philip; Kristiansen, Karsten; Jørgensen, Claus; Krieg, Peter

    12R-lipoxygenase (12R-LOX) and epidermis-type LOX-3 (eLOX-3) are novel members of the multigene family of mammalian LOX. A considerable gap exists between the identification of these enzymes and their biologic function. Here, we present evidence that 12R-LOX and eLOX-3, acting in sequence, and e...... evidence indicates that this ligand is an eLOX-3-derived product. In accordance with this data is the observation that forced expression of eLOX-3 enhances adipocyte differentiation....

  4. Inhibition of adipocyte differentiation by resistin-like molecule alpha. Biochemical characterization of its oligomeric nature

    Blagoev, Blagoy; Kratchmarova, Irina; Nielsen, Mogens M;

    2002-01-01

    A novel family of cysteine-rich secreted proteins with unique tissue distribution has recently been identified. One of the members, resistin (for "resistance to insulin"), also called FIZZ3, was identified in a screen for molecules that are down-regulated in mature adipocytes upon administration of...... thiazolidinediones. The prototypical member of this family was originally identified from bronchoalveolar lavage fluid of inflamed lungs and designated FIZZ1 ("found in inflammatory zone"). This molecule was also found to be highly expressed in adipose tissue and was named resistin-like molecule alpha (RELMalpha...... process of muscle differentiation....

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

    Elabd, Christian; Chiellini, Chiara; Carmona, Mamen;

    2009-01-01

    In contrast to the earlier contention, adult humans have been shown recently to possess active brown adipose tissue with a potential of being of metabolic significance. Up to now, brown fat precursor cells have not been available for human studies. We have shown previously that human multipotent...... adipose-derived stem (hMADS) cells exhibit a normal karyotype and high self-renewal ability; they are known to differentiate into cells that exhibit the key properties of human white adipocytes, that is, uncoupling protein two expression, insulin-stimulated glucose uptake, lipolysis in response to beta...

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

    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...

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

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

    2009-01-01

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

  8. Vav1 Regulates Mesenchymal Stem Cell Differentiation Decision Between Adipocyte and Chondrocyte via Sirt1.

    Qu, Peng; Wang, Lizhen; Min, Yongfen; McKennett, Lois; Keller, Jonathan R; Lin, P Charles

    2016-07-01

    Mesenchymal stem cells (MSCs) are multipotent stromal cells residing in the bone marrow. MSCs have the potential to differentiate to adipocytes, chondrocytes, and other types of cells. In this study, we investigated the molecular mechanism that controls MSC cell fate decisions for differentiation. We found that Vav1, a guanine nucleotide exchange factor for Rho GTPase, was highly expressed in MSCs. Interestingly, loss of Vav1 in MSCs led to spontaneous adipogenic but impaired chondrogenic differentiation, and accordingly Vav1 null mice displayed an increase in fat content and a decrease in cartilage. Conversely, ectopic expression of Vav1 in MSCs reversed this phenotype, and led to enhanced MSC differentiation into chondrocyte but retarded adipogenesis. Mechanistically, loss of Vav1 reduced the level of Sirt1, which was responsible for an increase of acetylated PPARγ. As acetylation activates PPARγ, it increased C/EBPα expression and promoted adipogenesis. On the other hand, loss of Vav1 resulted in an increase of acetylated Sox9, a target of Sirt1. As acetylation represses Sox9 activity, it led to a dramatic reduction of collagen 2α1, a key regulator in chondrocyte differentiation. Finally, we found that Vav1 regulates Sirt1 in MSCs through Creb. Together this study reveals a novel function of Vav1 in regulating MSC cell fate decisions for differentiation through Sirt1. Sirt1 deacetylates PPARγ and Sox9, two key mediators that control adipocyte and chondrocyte differentiation. The acetylation status of PPARγ and Sox9 has opposite effects on its activity, thereby controlling cell fate decision. Stem Cells 2016;34:1934-1946. PMID:26990002

  9. ADAM12 induces actin cytoskeleton and extracellular matrix reorganization during early adipocyte differentiation by regulating beta1 integrin function

    Kawaguchi, Nobuko; Sundberg, Christina; Kveiborg, Marie;

    2003-01-01

    Changes in cell shape are a morphological hallmark of differentiation. In this study we report that the expression of ADAM12, a disintegrin and metalloprotease, dramatically affects cell morphology in preadipocytes, changing them from a flattened, fibroblastic appearance to a more rounded shape. We...... early adipocyte differentiation....

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

    Murumalla Ravi

    2011-11-01

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

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

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

    2012-01-01

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

  12. Bisindoylmaleimide I suppresses adipocyte differentiation through stabilization of intracellular β-catenin protein

    The Wnt/β-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/β-catenin signaling pathway. BIM increased β-catenin responsive transcription (CRT) and up-regulated intracellular β-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 γ (PPARγ) and CAATT enhancer-binding protein α (C/EBPα) in 3T3-L1 preadipocytes. Taken together, our findings indicate that BIM inhibits adipogenesis by increasing the stability of β-catenin protein in 3T3-L1 preadipocyte cells

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

    Lai, Jing [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China); Liu, Gexiu [Institute of Hematology, School of Medicine, Jinan University, Guangzhou, Guangdong (China); Yan, Guoyao [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China); He, Dongmei [Institute of Hematology, School of Medicine, Jinan University, Guangzhou, Guangdong (China); Zhou, Ying [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China); Chen, Shengting, E-mail: shengtingchen@sina.cn [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China)

    2015-06-26

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

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

    Orlando Robert A

    2007-10-01

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

  15. Prostanoid EP4 receptor is involved in suppression of 3T3-L1 adipocyte differentiation

    Prostaglandins (PGs) have been shown to play various roles in adipogenesis. In this study, we investigated on which PGE receptor subtypes are involved in the inhibition of 3T3-L1 preadipocyte differentiation. The triglyceride content of cells, used as an index of differentiation, was decreased when PGE2, the FP-agonist fluprostenol or dibutyryl cAMP, was exogenously added to differentiation cocktails. 3T3-L1 preadipocyte cells express mRNAs for the prostanoid EP4, FP, and IP receptors. PGE2 and the EP4 agonist AE1-329 increased cAMP levels in preadipocytes in a dose-dependent manner. AE1-329 suppressed the expression induction of differentiation marker genes such as resistin and peroxisome proliferator-activated receptor-γ. The inhibitory effect of PGE2 but not that of fluprostenol was reversed by the addition of the EP4 antagonist AE3-208. AE3-208 mimicked the differentiation-promoting effects of indomethacin. These results suggest that the EP4 receptor mediates the suppressive action of PGE2 in 3T3-L1 adipocyte differentiation

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

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

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

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

    2015-01-01

    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. PMID:26556335

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

    Xiaoyan Wang

    2015-11-01

    Full Text Available 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.

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

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

    2014-01-01

    Recent studies suggest that exposure to endocrine-disrupting compounds (EDCs) may play a role in the development of obesity. EDCs such as the flame retardant 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) have been shown to enhance adipocyte differentiation in the murine 3T3-L1 model. The mech...

  20. Flavanone exhibits PPARγ ligand activity and enhances differentiation of 3T3-L1 adipocytes

    Flavanones are class of polyphenolic compounds, some of which are found in foods and provide health benefits. In this study, we show that flavanone significantly enhances differentiation of 3T3-L1 preadipocytes. During adipogenesis, flavanone enhanced expression of genes and accumulation of proteins that are involved in adipocyte function. Some reports have indicated that flavanone inhibits proliferation of mammalian cells, and down-regulates expression of growth-related proteins. Such proteins include phosphorylated ERK1/2, cyclins, and Cdks that are important for an early event in adipogenesis, mitotic clonal expansion (MCE). We demonstrated that flavanone did not inhibit MCE or expression of MCE-related proteins, except for a modest inhibition of cyclin D1 expression. Using luciferase reporter assays, we found that flavanone acted as a peroxisome proliferator-activated receptor γ (PPARγ) ligand in a dose-dependent manner. Together, our results suggest that flavanone enhances adipogenesis, at least in part, through its PPARγ ligand activity.

  1. Estrogen-related receptor α modulates the expression of adipogenesis-related genes during adipocyte differentiation

    Estrogen-related receptor α (ERRα) 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 ERRα in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERRα and ERRα-related transcriptional coactivators, peroxisome proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) and PGC-1β, 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 ERRα-specific siRNA results in mRNA down-regulation of fatty acid binding protein 4, PPARγ, and PGC-1α in 3T3-L1 cells in the adipogenesis medium. ERRα and PGC-1β 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 ERRα in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERRα may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes

  2. Purple Sweet Potato Leaf Extract Induces Apoptosis and Reduces Inflammatory Adipokine Expression in 3T3-L1 Differentiated Adipocytes

    Shou-Lun Lee

    2015-01-01

    Full Text Available Background. Purple sweet potato leaves (PSPL are widely grown and are considered a healthy vegetable in Taiwan. PSPL contain a high content of flavonoids, and the boiling water-extracted PSPL (PSPLE is believed to prevent metabolic syndrome. However, its efficacy has not yet been verified. Therefore, we investigated the effect of PSPLE on adipocytes. Methods. The differentiated 3T3-L1 cells used in this study were derived from preadipocytes that were differentiated into adipocytes using an adipogenic agent (insulin, dexamethasone, and 3-isobutyl-1-methylxanthine; approximately 90% of the cells were differentiated using this method. Results. Treating the differentiated 3T3-L1 cells with PSPLE caused a dose-dependent decrease in the number of adipocytes rather than preadipocytes. In addition, treatment with PSPLE resulted in apoptosis of the differentiated 3T3-L1 cells as determined by DAPI analysis and flow cytometry. PSPLE also increased the expression of cleaved caspase-3 and poly ADP-ribose polymerase (PARP. Furthermore, PSPLE induced downregulation of interleukin-6 (IL-6 and tumor necrosis factor-α (TNF-α gene expression in the differentiated 3T3-L1 cells. Conclusions. These results suggest that PSPLE not only induced apoptosis but also downregulated inflammation-associated genes in the differentiated 3T3-L1 cells.

  3. Suppressive effects of saponin-enriched extracts from quinoa on 3T3-L1 adipocyte differentiation.

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

    2015-10-01

    This study was performed to investigate the effect of quinoa saponins (QS) on the differentiation of 3T3-L1 preadipocytes. QS inhibited triglyceride (TG) accumulation in the mature adipocytes, evidenced by oil-red O staining and intracellular quantification. Real time-PCR analysis and western blot analysis showed that QS significantly down-regulated the mRNA and protein expression of key adipogenic transcription factors, peroxisome proliferator-activated receptor γ (PPARγ), and CCAAT/enhancer-binding protein alpha (C/EBPα), however, they had no significant effect on CCAAT/enhancer-binding protein beta (C/EBPβ) and CCAAT/enhancer-binding protein delta (C/EBPδ) which are the upstream regulators for adipogenesis compared with mature adipocytes. QS also reduced mRNA and protein expression of sterol regulatory element-binding protein-1c (SREBP-1c) related to the late stage of adipogenesis. Furthermore, lipoprotein lipase (LPL), adipocyte protein 2 (aP2) and glucose transporter 4 (Glut4), as adipocyte specific genes, were decreased in mature adipocytes by QS treatment. These findings indicate that QS are capable of suppressing adipogenesis and therefore they seem to be natural bioactive factors effective in adipose tissue mass modulation. PMID:26242624

  4. Epigenetic Priming Confers Direct Cell Trans-Differentiation From Adipocyte to Osteoblast in a Transgene-Free State.

    Cho, Young-Dan; Bae, Han-Sol; Lee, Dong-Seol; Yoon, Won-Joon; Woo, Kyung-Mi; Baek, Jeong-Hwa; Lee, Gene; Park, Joo-Cheol; Ku, Young; Ryoo, Hyun-Mo

    2016-07-01

    The bone marrow of healthy individuals is primarily composed of osteoblasts and hematopoietic cells, while that of osteoporosis patients has a larger portion of adipocytes. There is evidence that the epigenetic landscape can strongly influence cell differentiation. We have shown that it is possible to direct the trans-differentiation of adipocytes to osteoblasts by modifying the epigenetic landscape with a DNA methyltransferase inhibitor (DNMTi), 5'-aza-dC, followed by Wnt3a treatment to signal osteogenesis. Treating 3T3-L1 adipocytes with 5'-aza-dC induced demethylation in the hypermethylated CpG regions of bone marker genes; subsequent Wnt3a treatment drove the cells to osteogenic differentiation. When old mice with predominantly adipose marrow were treated with both 5'-aza-dC and Wnt3a, decreased fatty tissue and increased bone volume were observed. Together, our results indicate that epigenetic modification permits direct programming of adipocytes into osteoblasts in a mouse model of osteoporosis, suggesting that this approach could be useful in bone tissue-engineering applications. J. Cell. Physiol. 231: 1484-1494, 2016. © 2015 Wiley Periodicals, Inc. PMID:26335354

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

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

    2012-01-01

    Adipose tissue structure is altered during obesity, leading to deregulation of whole-body metabolism. Its function depends on its structure, in particular adipocytes number and differentiation stage. To better understand the mechanisms regulating adipogenesis, we have investigated the role of an...... is associated with CHOP10 mRNA and regulates its stability. CHOP10 expression is conserved in RNase L(-/-)-MEFs, maintaining preadipocyte state while impairing their terminal differentiation. RNase L(-/-)-MEFs have decreased lipids storage capacity, insulin sensitivity and glucose uptake. Expression...... of ectopic RNase L in RNase L(-/-)-MEFs triggers CHOP10 mRNA instability, allowing increased lipids storage, insulin response and glucose uptake. Similarly, downregulation of CHOP10 mRNA with CHOP10 siRNA in RNase L(-/-)-MEFs improves their differentiation in adipocyte. In vivo, aged RNase L...

  6. Icariin Stimulates Differentiation and Suppresses Adipocytic Transdifferentiation of Primary Osteoblasts Through Estrogen Receptor-Mediated Pathway.

    Zhang, Dawei; Fong, Chichun; Jia, Zhenbin; Cui, Liao; Yao, Xinsheng; Yang, Mengsu

    2016-08-01

    Icariin, the main constituent of Herba Epimedii, appears to be a promising alternative to classic drugs used to treat osteoporosis. However, the detailed molecular mechanisms of its action and the role of icariin in the cross-talk between osteoblasts and adipocytes remain unclear. The present study was designed to investigate the gene expression profile of primary osteoblasts in the presence of icariin, and the effects of icariin on the differentiation and adipogenic transdifferentiation of osteoblasts. Cellular and molecular markers expressed during osteoblastic differentiation were assessed by cytochemical analysis, real-time quantitative PCR, Western blotting, and cDNA microarray analysis. Results indicated that icariin up-regulated the expression of runt-related transcription factor 2 (Runx2), bone morphogenetic protein 2 (Bmp2), and collagen type 1 (Col1) genes, and down-regulated the expression of the peroxisome proliferator-activated receptor γ (Pparg) and CCAAT/enhancer-binding protein β (Cebpb) genes. These effects were blocked by ICI 182,780, suggesting that icariin may be acting via the estrogen receptor (ER). Results also demonstrated that the ratio of osteoprotegerin (Opg)/receptor activator of nuclear factor kappa B ligand (Rankl) expression was up-regulated following treatment with icariin. In total, osteoblastic gene expression profile analysis suggested that 33 genes were affected by icariin; these could be sub-divided into nine functional categories. It appears that icariin could stimulate the differentiation and mineralization of osteoblasts, regulate the differentiation of osteoclasts, and inhibit the adipogenic transdifferentiation of osteoblasts, therefore increasing the number of osteoblasts undergoing differentiation to mature osteoblasts, via an ER-mediated pathway. In summary, icariin may exhibit beneficial effects on bone health, especially for patients with osteoporosis and obesity. PMID:27061090

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

    Jacqueline M Lane

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

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

    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

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

    J. Zych

    2013-05-01

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

  10. Lipid droplets characterization in adipocyte differentiated 3T3-L1 cells: size and optical density distribution

    V. Rizzatti

    2013-08-01

    Full Text Available The 3T3-L1 cell line, derived from 3T3 cells, is widely used in biological research on adipose tissue. 3T3-L1 cells have a fibroblast-like morphology, but, under appropriate conditions, they differentiate into an adipocyte-like phenotype. During the differentiation process, 3T3-L1 cells increase the synthesis of triglycerides and acquire the behavior of adipose cells. In particular, triglycerides accumulate in lipid droplets (LDs embedded in the cytoplasm. The number and the size distribution of the LDs is often correlated with obesity and many other pathologies linked with fat accumulation. The integrated optical density (IOD of the LDs is related with the amount of triglycerides in the droplets. The aim of this study is the attempt to characterize the size distribution and the IOD of the LDs in 3T3-L1 differentiated cells. The cells were differentiated into adipocytes for 5 days with a standard procedure, stained with Oil Red O and observed with an optical microscope. The diameter, area, optical density of the LDs were measured. We found an asymmetry of the kernel density distribution of the maximum Feret’s diameter of the LDs with a tail due to very large LDs. More information regarding the birth of the LDs could help in finding the best mathematical model in order to analyze fat accumulation in adipocytes.

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

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

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

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

    2011-06-17

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

  13. Differential Expression and Function of Stamp Family Proteins in Adipocyte Differentiation

    2013-01-01

    Six transmembrane protein of prostate (Stamp) proteins play an important role in prostate cancer cell growth. Recently, we found that Stamp2 has a critical role in the integration of inflammatory and metabolic signals in adipose tissue where it is highly expressed and regulated by nutritional and metabolic cues. In this study, we show that all Stamp family members are differentially regulated during adipogenesis: whereas Stamp1 expression is significantly decreased upon differentiation, Stamp...

  14. The size of the primary cilium and acetylated tubulin are modulated during adipocyte differentiation: Analysis of HDAC6 functions in these processes.

    Forcioli-Conti, Nicolas; Estève, David; Bouloumié, Anne; Dani, Christian; Peraldi, Pascal

    2016-05-01

    The primary cilium is an organelle present in most of the cells of the organism. Ciliopathies, such as the Bardet Biedl and the Alstrom syndromes are associated with obesity. We, and others, have shown that the primary cilium undergoes size modifications during adipocyte differentiation of human adipose stromal cells. We show here that the levels of acetylated α-tubulin, a constituent of the primary cilium, and the expression of HDAC6, the enzyme that deacetylates α-tubulin and is responsible for the loss of the cilium during mitosis, are modulated during adipogenesis. Moreover, during adipocyte differentiation cells that express higher level of HDAC6 are the first to lose their primary cilium. We have investigated the function of HDAC6 on adipocyte differentiation and on the primary cilium. We observe that inhibition of HDAC6 activity leads to a decrease in adipocyte differentiation. This is associated with an inhibition of the initial elongation of the cilium. Interestingly, overexpression of HDAC6 inhibits adipocyte differentiation and blunts the elongation of the primary cilium. In both situations, inhibition of adipocyte differentiation was not associated with an inhibition of the glucocorticoid receptor activity. This indicates that HDAC6 controls adipogenesis through the levels of acetylated α-tubulin. Moreover, we show that although HDAC6 expression increases during adipocyte differentiation it is not sufficient to provoke the loss of the cilium. This suggests the existence of a novel mechanism for the loss of the cilium. Together, these data indicate that HDAC6, and acetylated α-tubulin, are important regulator of adipocyte differentiation. PMID:26363102

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

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

    2015-01-01

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

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

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

    2015-01-01

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

  17. Effect of different culture systems on adipocyte differentiation-related protein (ADRP) in bovine embryos.

    Al Darwich, A; Perreau, C; Tsikis, G; Coudert, E; Touzé, J L; Briant, E; Beckers, J F; Mermillod, P; Guignot, F

    2014-03-01

    Bovine embryos cultured in serum-containing media abnormally accumulate lipid droplets, compared to their in vivo counterparts. The objective of this study was to investigate the effect of different culture systems on the mRNA expression and on the quantification and localisation of adipocyte differentiation-related protein (ADRP), a protein associated with lipid accumulation in bovine blastocysts. Two experiments were independently performed for ADRP mRNA expression analysis. In experiment A, blastocysts were produced in modified synthetic oviduct fluid (mSOF)+10% foetal calf serum (FCS), in coculture (bovine oviduct epithelial cells, Boec) and in ewe oviducts, whereas in experiment B, they were produced in mSOF+10μM docosahexaenoic acid (DHA) and in vivo. Control groups were also performed. ADRP mRNA expression was downregulated in the Boec, ewe oviduct and in vivo groups compared to the 10% FCS or DHA groups, respectively. Moreover, the expression of this protein was downregulated in the Boec group compared to the control group (P<0.05). A third experiment (experiment C) was performed to quantify and localise ADRP protein. Boec, in vivo and control groups were tested. After immunofluorescence staining followed by confocal microscopy analysis, embryonic ADRP was clearly localised around lipid droplets, indicating that ADRP is also a lipid droplet coat protein in bovine embryos. In conclusion, our results demonstrate that bovine embryos at the blastocyst stage expressed ADRP mRNA and protein, and that the embryonic culture system modified this expression. PMID:24560670

  18. S6K1 Plays a Critical Role in Early Adipocyte Differentiation

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

    2010-01-01

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

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

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

    2014-02-15

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

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

    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

  1. Effects of quercetin, a natural phenolic compound, in the differentiation of human mesenchymal stem cells (MSC) into adipocytes and osteoblasts.

    Casado-Díaz, Antonio; Anter, Jaouad; Dorado, Gabriel; Quesada-Gómez, José Manuel

    2016-06-01

    Natural phenols may have beneficial properties against oxidative stress, which is associated with aging and major chronic aging-related diseases, such as loss of bone mineral mass (osteoporosis) and diabetes. The main aim of this study was to analyze the effect of quercetin, a major nutraceutical compound present in the "Mediterranean diet", on mesenchymal stem-cell (MSC) differentiation. Such cells were induced to differentiate into osteoblasts or adipocytes in the presence of two quercetin concentrations (0.1 and 10μM). Several physiological parameters and the expression of osteoblastogenesis and adipogenesis marker genes were monitored. Quercetin (10μM) inhibited cell proliferation, alkaline phosphatase (ALPL) activity and mineralization, down-regulating the expression of ALPL, collagen type I alpha 1 (COL1A1) and osteocalcin [bone gamma-carboxyglutamate protein (BGLAP)] osteoblastogenesis-related genes in MSC differentiating into osteoblasts. Moreover, in these cultures, CCAAT/enhancer-binding protein alpha (CEBPA) and peroxisome proliferator-activated receptor gamma 2 (PPARG2) adipogenic genes were induced, and cells differentiated into adipocytes were observed. Quercetin did not affect proliferation, but increased adipogenesis, mainly at 10-μM concentration in MSC induced to differentiate to adipocytes. β- and γ-catenin (plakoglobin) nuclear levels were reduced and increased, respectively, in quercetin-treated cultures. This suggests that the effect of high concentration of quercetin on MSC osteoblastic and adipogenic differentiation is mediated via Wnt/β-catenin inhibition. In conclusion, quercetin supplementation inhibited osteoblastic differentiation and promoted adipogenesis at the highest tested concentration. Such possible adverse effects of high quercetin concentrations should be taken into account in nutraceutical or pharmaceutical strategies using such flavonol. PMID:27142748

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

    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.

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

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

    2015-01-01

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

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

    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

  5. Skp2 promotes adipocyte differentiation via a p27Kip1-independent mechanism in primary mouse embryonic fibroblasts

    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 p27Kip1, a principal target of the SCFSkp2 complex. Genetic ablation of p27Kip1 in MEFs promoted both lipid accumulation and adipocyte-specific gene expression. However, depletion of p27Kip1 by adenovirus-mediated RNA interference failed to correct the impairment of adipocyte differentiation in Skp2-/- MEFs. In contrast, troglitazone, a high-affinity ligand for peroxisome proliferator-activated receptor γ (PPARγ), largely restored lipid accumulation and PPARγ gene expression in Skp2-/- 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 p27Kip1 expression.

  6. Lipid Droplets Characterization in Adipocyte Differentiated 3T3-L1 Cells: Size and Optical Density Distribution

    V. Rizzatti; F. Boschi; Pedrotti, M.; E. Zoico; A. Sbarbati; Zamboni, M.

    2013-01-01

    The 3T3-L1 cell line, derived from 3T3 cells, is widely used in biological research on adipose tissue. 3T3-L1 cells have a fibroblast-like morphology, but, under appropriate conditions, they differentiate into an adipocyte-like phenotype. During the differentiation process, 3T3-L1 cells increase the synthesis of triglycerides and acquire the behavior of adipose cells. In particular, triglycerides accumulate in lipid droplets (LDs) embedded in the cytoplasm. The number and the size distributio...

  7. MicroRNA-24 promotes 3T3-L1 adipocyte differentiation by directly targeting the MAPK7 signaling.

    Jin, Min; Wu, Yutao; Wang, Jing; Chen, Jian; Huang, Yiting; Rao, Jinpeng; Feng, Chun

    2016-05-20

    Over the past years, MicroRNAs (miRNAs) act as a vital role in harmony with gene regulation and maintaining cellular homeostasis. It is well testified that miRNAshave been involved in numerous physiological and pathological processes, including embryogenesis, cell fate decision, and cellular differentiation. Adipogenesis is an organized process of cellular differentiation by which pre-adipocytes differentiate towards mature adipocytes, and it is tightly modulated by a series of transcription factors such as peroxisome proliferator-activated receptor γ (PPAR-γ) and sterol regulatory-element binding proteins 1 (SREBP1). However, the molecular mechanisms underlying the connection between miRNAs and adipogenesis-related transcription factors remain obscure. In this study, we unveiled that miR- 24 was remarkably upregulated during 3T3-L1 adipogenesis. Overexpression of miR-24 significantly promoted 3T3-L1 adipogenesis, as evidenced by its ability to increase the expression of PPAR-γ and SREBP1, lipid droplet formation and triglyceride (TG) accumulation. Furthermore, we found that neither ectopic expression of miR-24nor miR-24 inhibitor affect cell proliferation and cell cycle progression. Finally, we demonstrated that miR-24 plays the modulational role by directly repressing MAPK7, a key number in the MAPK signaling pathway. These data indicate that miR-24 is a novel positive regulator of adipocyte differentiation by targeting MAPK7, which provides new insights into the molecular mechanism of miRNA-mediated cellular differentiation. PMID:27103442

  8. Indole-3-carbinol directly targets SIRT1 to inhibit adipocyte differentiation.

    Choi, Y; Um, S J; Park, T

    2013-06-01

    Indole-3-carbinol (I3C), a natural product of Brassica vegetables such as broccoli and cabbage, inhibits proliferation and induces apoptosis in various cancer cells. I3C has recently received attention as a possible anti-obesity agent. However, how I3C interacts with specific targets in the pathways involved in obesity and metabolic disorders is unknown. Silent mating type information regulation 2 homolog 1 (SIRT1), a NADþ-dependent deacetylase sirtuin, has recently emerged as a novel therapeutic target for metabolic diseases. Herein, we report that I3C is a potent, specific SIRT1 activator efficacious in cultured 3T3-L1 cell lines. A pull-down assay showed that I3C binds to SIRT1. To assess the significance of this binding, we determined whether I3C could activate SIRT1 deacetylase activity in a cell-free system. We found that I3C binds to SIRT1 and activates SIRT1 deacetylase activity in 3T3-L1 cells. In addition, I3C did not inhibit adipocyte differentiation in 3T3-L1 cells in which SIRT1 was knockdowned. Further, reverse transcriptase polymerase chain reaction analysis showed that I3C treatment reduced mRNA levels of adipogenic genes that encode for C/EBPa, PPARg2, FAS, and aP2 in 3T3-L1 cells but not in SIRT1 knockdown cells. Overall, these results suggested that I3C ameliorates adipogenesis by activating SIRT1 in 3T3-L1 cells. PMID:22986685

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

    Eduardsen, Kathrine; Larsen, Susanne; Novak, Ivana;

    2011-01-01

    osmotic cell shrinkage (RVI), accompanied by increased swelling-activated taurine efflux. However, caveolin-1 distribution was not detectably altered after osmotic swelling or shrinkage, and caveolae integrity, as studied by cholesterol depletion or expression of dominant negative Cav-1, was not required...... had no detectable effect on InsR, yet increased ERK1/2 phosphorylation. In conclusion, differentiated 3T3-L1 adipocytes exhibit greatly accelerated RVD and RVI responses and increased swelling-activated taurine efflux compared to pre-adipocytes. Furthermore, in pre-adipocytes, Cav-1/caveolae integrity...

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

    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. PMID:24626784

  11. Anti-obesity effect of resveratrol-amplified grape skin extracts on 3T3-L1 adipocytes differentiation

    Zhang, Xian-Hua; Huang, Bo; Choi, Soo-Kyong; Seo, Jung-Sook

    2012-01-01

    Resveratrol (3,4,5-trihydroxy-trans-stilbene), a phytoalexin found in grape skin, grape products, and peanuts as well as red wine, has been reported to have various biological and pharmacological properties. The purpose of this study was to investigate the anti-obesity effect of resveratrol-amplified grape skin extracts on adipocytes. The anti-obesity effects of grape skin extracts were investigated by measuring proliferation and differentiation in 3T3-L1 cells. The effect of grape skin ethan...

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

    RNA interference (RNAi) has been used in functional genomics and offers innovative approaches in the development of novel therapeutics. Human mesenchymal stem cells offer a unique cell source for tissue engineering/regeneration strategies. The current study examined the potential of small interfering RNAs (siRNA) against human peroxisome proliferator activated receptor gamma (PPARγ) to suppress adipocyte differentiation (adipogenesis) in human preadipocytes and fetal-femur-derived mesenchymal cells. Adipogenesis was investigated using cellular and biochemical analysis. Transient transfection with PPARγ-siRNA using a liposomal-based strategy resulted in a significant inhibition of adipogenesis in human preadipocytes and fetal-femur-derived mesenchymal cells, compared to controls (cell, liposomal and negative siRNA). The inhibitory effect of PPARγ-siRNA was supported by testing human PPARγ mRNA and adipogenic associated genes using reverse transcription polymerase chain reaction (RT-PCR) to adiponectin receptor 1 and 2 as well as examination of fatty acid binding protein 3 (FABP3) expression, an adipocyte-specific marker. The current studies indicate that PPARγ-siRNA is a useful tool to study adipogenesis in human cells, with potential applications both therapeutic and in the elucidation of mesenchymal cell differentiation in the modulation of cell differentiation in human mesenchymal cells

  13. Transcription factor PU.1 is expressed in white adipose and inhibits adipocyte differentiation

    PU.1 transcription factor is a critical regulator of hematopoiesis and leukemogenesis. Because PU.1 interacts with transcription factors GATA-2 and C/EBPa, both of which are involved in the regulation of adipogenesis, we investigated whether PU.1 also plays a role in the regulation of adipocyte diff...

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

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

    2014-11-14

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

  15. Global mapping of cell type-specific open chromatin by FAIRE-seq reveals the regulatory role of the NFI family in adipocyte differentiation.

    Hironori Waki

    2011-10-01

    Full Text Available 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

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

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

  17. Polychlorinated Biphenyl-77 Induces Adipocyte Differentiation and Proinflammatory Adipokines and Promotes Obesity and Atherosclerosis

    Arsenescu, Violeta; Arsenescu, Razvan I; King, Victoria; Swanson, Hollie; Cassis, Lisa A.

    2008-01-01

    Background Obesity, an inflammatory condition linked to cardiovascular disease, is associated with expansion of adipose tissue. Highly prevalent coplanar polychlorinated biphenyls (PCBs) such as 3,3′,4,4′-tetrachlorobiphenyl (PCB-77) accumulate in adipose tissue because of their lipophilicity and increase with obesity. However, the effects of PCBs on adipocytes, obesity, and obesity-associated cardiovascular disease are unknown. Objectives In this study we examined in vitro and in vivo effect...

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

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

    2014-01-01

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

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

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

    2012-01-01

    Brown adipose tissue is specialized to burn lipids for thermogenesis and energy expenditure. Second-generation antipsychotics (SGA) are the most commonly used drugs for schizophrenia with several advantages over first-line drugs, however, it can cause clinically-significant weight gain. To reveal the involvement of brown adipocytes in SGA-induced weight gain, we compared the effect of clozapine, quetiapine, and ziprasidone, SGA with different propensities to induce weight gain, on the differe...

  20. Transcriptional regulatory program in wild-type and retinoblastoma gene-deficient mouse embryonic fibroblasts during adipocyte differentiation

    Hansen Jacob B

    2011-05-01

    Full Text Available Abstract Background Although many molecular regulators of adipogenesis have been identified a comprehensive catalogue of components is still missing. Recent studies showed that the retinoblastoma protein (pRb was expressed in the cell cycle and late cellular differentiation phase during adipogenesis. To investigate this dual role of pRb in the early and late stages of adipogenesis we used microarrays to perform a comprehensive systems-level analysis of the common transcriptional program of the classic 3T3-L1 preadipocyte cell line, wild-type mouse embryonic fibroblasts (MEFs, and retinoblastoma gene-deficient MEFs (Rb-/- MEFs. Findings Comparative analysis of the expression profiles of 3T3-L1 cells and wild-type MEFs revealed genes involved specifically in early regulation of the adipocyte differentiation as well as secreted factors and signaling molecules regulating the later phase of differentiation. In an attempt to identify transcription factors regulating adipogenesis, bioinformatics analysis of the promoters of coordinately and highly expressed genes was performed. We were able to identify a number of high-confidence target genes for follow-up experimental studies. Additionally, combination of experimental data and computational analyses pinpointed a feedback-loop between Pparg and Foxo1. To analyze the effects of the retinoblastoma protein at the transcriptional level we chose a perturbated system (Rb-/- MEFs for comparison to the transcriptional program of wild-type MEFs. Gene ontology analysis of 64 deregulated genes showed that the Rb-/- MEF model exhibits a brown(-like adipocyte phenotype. Additionally, the analysis results indicate a different or additional role for pRb family member involvement in the lineage commitment. Conclusion In this study a number of commonly modulated genes during adipogenesis in 3T3-L1 cells and MEFs, potential transcriptional regulation mechanisms, and differentially regulated targets during adipocyte

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

    Kratchmarova, Irina; Kalume, Dario E; Blagoev, Blagoy; Scherer, Philipp E; Podtelejnikov, Alexandre V; Molina, Henrik; Bickel, Perry E; Andersen, Jens S; Fernandez, Minerva M; Bunkenborg, Jacob; Roepstorff, Peter; Kristiansen, Karsten; Lodish, Harvey F; Mann, Matthias; Pandey, Akhilesh

    2002-01-01

    cholinergic neurostimulating peptide, neutrophil gelatinase-associated lipocalin, and haptoglobin to be expressed highly by mature adipocytes. We also used liquid chromatography-based separation followed by automated tandem mass spectrometry to identify proteins secreted by mature adipocytes. Several...

  2. Gene expression profiles in Atlantic salmon adipose-derived stromo-vascular fraction during differentiation into adipocytes

    Škugor Stanko

    2010-01-01

    Full Text Available Abstract Background Excessive fat deposition is one of the largest problems faced by salmon aquaculture industries, leading to production losses due to high volume of adipose tissue offal. In addition, increased lipid accumulation may impose considerable stress on adipocytes leading to adipocyte activation and production and secretion of inflammatory mediators, as observed in mammals. Results Microarray and qPCR analyses were performed to follow transcriptome changes during adipogenesis in the primary culture of adipose stromo-vascular fraction (aSVF of Atlantic salmon. Cellular heterogeneity decreased by confluence as evidenced by the down-regulation of markers of osteo/chondrogenic, myogenic, immune and vasculature lineages. Transgelin (TAGLN, a marker of the multipotent pericyte, was prominently expressed around confluence while adipogenic PPARγ was up-regulated already in subconfluent cells. Proliferative activity and subsequent cell cycle arrest were reflected in the fluctuations of pro- and anti-mitotic regulators. Marked regulation of genes involved in lipid and glucose metabolism and pathways producing NADPH and glycerol-3-phosphate (G3P was seen during the terminal differentiation, also characterised by diverse stress responses. Activation of the glutathione and thioredoxin antioxidant systems and changes in the iron metabolism suggested the need for protection against oxidative stress. Signs of endoplasmic reticulum (ER stress and unfolded protein response (UPR occured in parallel with the increased lipid droplet (LD formation and production of secretory proteins (adipsin, visfatin. The UPR markers XBP1 and ATF6 were induced together with genes involved in ubiquitin-proteasome and lysosomal proteolysis. Concurrently, translation was suppressed as evidenced by the down-regulation of genes encoding elongation factors and components of the ribosomal machinery. Notably, expression changes of a panel of genes that belong to different

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

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

    2005-01-01

    Activation of canonical Wnt signaling inhibits brown adipogenesis of cultured cells by impeding induction of PPARgamma and C/EBPalpha. Although enforced expression of these adipogenic transcription factors restores lipid accumulation and expression of FABP4 in Wnt-expressing cells, additional...... expression of PGC-1alpha and UCP1, the presence of unilocular lipid droplets and expression of white adipocyte genes suggest conversion of brown adipose tissue to white. Reciprocal expression of Wnt10b with UCP1 and PGC-1alpha in interscapular tissue from cold-challenged or genetically obese mice provides...

  4. Differentiation of Rat bone marrow Mesenchymal stem cells into Adipocytes and Cardiomyocytes after treatment with platelet lysate

    Homayouni Moghadam, Farshad; Tayebi, Tahereh; Barzegar, Kazem

    2016-01-01

    Background: Mesenchymal stem cells (MSCs) are multipotential cells and their therapeutic potency is under intense investigation. Studying the effect of different induction factors on MSCs could increase our knowledge about the differentiation potency of these cells. One of the most important sources of these factors in mammalian body is platelet. Platelet lysate (PL) contains many growth factors and therefore, it can be used as a differentiation inducer. In the present study, the effect of PL on differentiation of rat bone marrow MSCs into cardiomyocytes was studied. Materials and Methods: To study the differentiation-inducing effect of PL, MSCs were treated with 2.5, 5 and 10% PL. Early results of this study showed that PL in high concentrations (10%) induces adipogenic differentiation of MSCs. Therefore, to evaluate differentiation to cardiomyocytes, MSCs were cultured in media containing lower levels of PL (2.5% and 5%) and then cardiomyogenic differentiation was induced by treatment with 5-azacytidine. Differentiation of MSCs was evaluated using direct observation of beating cells, immunostaining and real-time PCR techniques. Results: The results of qPCR showed that treatment with PL alone increased the expression of cardiac alpha actinin (CAA) being predictable by earlier observation of beating cells in PL-treated groups. The results of staining assays against cardiac alpha actinin also showed that there were stained cells in PL-treated groups. Conclusion: The results of the present study showed that PL is a powerful induction factor for differentiation of MSCs into different cell lines such as cardiomyocytes and adipocytes. PMID:27047647

  5. Adipocyte Differentiation-Related Protein and OXPAT in Rat and Human Skeletal Muscle: Involvement in Lipid Accumulation and Type 2 Diabetes Mellitus

    Minnaard, R.; Schrauwen, P.; Schaart, G.; Jorgensen, J.A.; Lenaers, E.; Mensink, M.R.; Hesselink, M.K.C.

    2009-01-01

    Setting: A disordered lipid metabolism is implicated in the development of skeletal muscle insulin resistance. Lipid droplet proteins of the PAT [perilipin, adipocyte differentiation-related protein (ADRP), and TIP47] family have been shown to regulate lipid accumulation and intracellular metabolism

  6. The orphan nuclear receptor Rev-Erbalpha is a peroxisome proliferator-activated receptor (PPAR) gamma target gene and promotes PPARgamma-induced adipocyte differentiation

    Fontaine, Coralie; Dubois, Guillaume; Duguay, Yannick;

    2003-01-01

    Rev-Erbalpha (NR1D1) is an orphan nuclear receptor encoded on the opposite strand of the thyroid receptor alpha gene. Rev-Erbalpha mRNA is induced during adipocyte differentiation of 3T3-L1 cells, and its expression is abundant in rat adipose tissue. Peroxisome proliferator-activated receptor gamma...

  7. cis9, trans11-Conjugated Linoleic Acid Differentiates Mouse 3T3-L1 Preadipocytes into Mature Small Adipocytes through Induction of Peroxisome Proliferator-activated Receptor γ.

    Sakuma, Satoru; Nishioka, Yuki; Imanishi, Ryohta; Nishikawa, Kenji; Sakamoto, Hirotada; Fujisawa, Junji; Wada, Koichiro; Kamisaki, Yoshinori; Fujimoto, Yohko

    2010-09-01

    Dietary conjugated linoleic acid (CLA) has been reported to exhibit a number of therapeutic effects in animal models and patients, such as anti-hypertensive, anti-hyperlipidemic, anti-arteriosclerotic, anti-carcinogenic, and anti-diabetic effects. However, the underlying mechanism is not well-characterized. In the present study, the effects of cis(c)9, trans(t)11-CLA on the differentiation of mouse 3T3-L1 preadipocytes into mature adipocytes were examined. Treatment with c9, t11-CLA in the presence of insulin, dexamethasone, and 3-isobutyl-1-methyl-xanthine (differentiation cocktail) significantly stimulated the accumulation of triacylglycerol. The microscopic observation of cells stained by Oil Red O demonstrated that c9, t11-CLA increases the amount and proportion of small mature adipocytes secreting adiponectin, a benign adipocytokine, when compared to the differentiation cocktail alone. Furthermore, c9, t11-CLA increased bioactive peroxisome proliferator-activated receptor γ (PPARγ) levels in a nuclear extract of 3T3-L1 cells, suggesting the enhancing effect of this fatty acid on the nuclear transmission of PPARγ, a master regulator of adipocyte differentiation, in 3T3-L1 cells. These results suggest that the therapeutic effects of c9, t11-CLA on lifestyle-related diseases are partially due to the enhanced formation of small adipocytes from preadipocytes via PPARγ stimulation. PMID:20838573

  8. 3,4-Oxo-isopropylidene-shikimic acid promotes adiopkine expression during murine 3T3-L1 fibroblast differentiation into adipocytes

    Shifen Dong

    2014-10-01

    Conclusions: These findings demonstrated that ISA promoted adipogenesis by up-regulating expressions of C/EBP β, PPAR γ, C/EBP α, aP2 and FAS, and also stimulated adipokines during adipocyte differentiation. Further study should clarify the relationship between stimulation of adipokines and cognitive enhancing effect of ISA.

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

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

    2002-01-01

    A functional retinoblastoma protein (pRB) is required for adipose conversion of preadipocyte cell lines and primary mouse embryo fibroblasts (MEFs) in response to treatment with standard adipogenic inducers. Interestingly, lack of functional pRB in MEFs was recently linked to elevated Ras activity...... of the mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase 1/2 (ERK1/2), and protein kinase B (PKB)/Akt, which exert opposing effects on adipogenesis, with ERK1/2 inhibiting and PKB/Akt promoting terminal differentiation. Here we report that the levels of activated ERK1/2 and PKB...

  10. PCB-153 shows different dynamics of mobilisation from differentiated rat adipocytes during lipolysis in comparison with PCB-28 and PCB-118.

    Caroline Louis

    Full Text Available BACKGROUND: Polychlorinated biphenyls (PCBs are persistent organic pollutants. Due to their lipophilic character, they are preferentially stored within the adipose tissue. During the mobilisation of lipids, PCBs might be released from adipocytes into the bloodstream. However, the mechanisms associated with the release of PCBs have been poorly studied. Several in vivo studies followed their dynamics of release but the complexity of the in vivo situation, which is characterised by a large range of pollutants, does not allow understanding precisely the behaviour of individual congeners. The present in vitro experiment studied the impact of (i the number and position of chlorine atoms of PCBs on their release from adipocytes and (ii the presence of other PCB congeners on the mobilisation rate of such molecules. METHODOLOGY/PRINCIPAL FINDINGS: Differentiated rat adipocytes were used to compare the behaviour of PCB-28, -118 and -153. Cells were contaminated with the three congeners, alone or in cocktail, and a lipolysis was then induced with isoproterenol during 12 hours. Our data indicate that the three congeners were efficiently released from adipocytes and accumulated in the medium during the lipolysis. Interestingly, for a same level of cell lipids, PCB-153, a hexa-CB with two chlorine atoms in ortho-position, was mobilised slower than PCB-28, a tri-CB, and PCB-118, a penta-CB, which are both characterised by one chlorine atom in ortho-position. It suggests an impact of the chemical properties of pollutants on their mobilisation during periods of negative energy balance. Moreover, the mobilisation of PCB congeners, taken individually, did not seem to be influenced by the presence of other congeners within adipocytes. CONCLUSION/SIGNIFICANCE: These results not only highlight the obvious mobilisation of PCBs from adipocytes during lipolysis, in parallel to lipids, but also demonstrate that the structure of congeners defines their rate of release

  11. Set7/9, a methyltransferase, regulates the thermogenic program during brown adipocyte differentiation through the modulation of p53 acetylation.

    Son, Min Jeong; Kim, Won Kon; Park, Anna; Oh, Kyoung-Jin; Kim, Jeong-Hoon; Han, Baek Soo; Kim, Il Chul; Chi, Seung-Wook; Park, Sung Goo; Lee, Sang Chul; Bae, Kwang-Hee

    2016-08-15

    Brown adipose tissue, which is mainly composed of brown adipocytes, plays a key role in the regulation of energy balance via dissipation of extra energy as heat, and consequently counteracts obesity and its associated-disorders. Therefore, brown adipocyte differentiation should be tightly controlled at the multiple regulation steps. Among these, the regulation at the level of post-translational modifications (PTMs) is largely unknown. Here, we investigated the changes in the expression level of the enzymes involved in protein lysine methylation during brown adipocyte differentiation by using quantitative real-time PCR (qPCR) array analysis. Several enzymes showing differential expression patterns were identified. In particular, the expression level of methyltransferase Set7/9 was dramatically repressed during brown adipocyte differentiation. Although there was no significant change in lipid accumulation, ectopic expression of Set7/9 led to enhanced expression of several key thermogenic genes, such as uncoupling protein-1 (UCP-1), Cidea, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), and PR domain containing 16 (PRDM16). In contrast, knockdown of endogenous Set7/9 led to significantly reduced expression of these thermogenic genes. Furthermore, suppressed mitochondrial DNA content and decreased oxygen consumption rate were also detected upon Set7/9 knockdown. We found that p53 acetylation was regulated by Set7/9-dependent interaction with Sirt1. Based on these results, we suggest that Set7/9 acts as a fine regulator of the thermogenic program during brown adipocyte differentiation by regulation of p53 acetylation. Thus, Set7/9 could be used as a valuable target for regulating thermogenic capacity and consequently to overcome obesity and its related metabolic diseases. PMID:27132805

  12. Downregulation of RelA (p65) by Rapamycin Inhibits Murine Adipocyte Differentiation and Reduces Fat Mass of C57BL/6J Mice despite High Fat Diet

    Ray, Peter D.; Maclellan, Reid A.; Jin He; Zhigang Liu; Jianguo Wu

    2014-01-01

    Rapamycin (RAPA) is a clinical immunosuppressive agent first reported in the literature in 1975 after its discovery in a soil sample from the island of Rapa Nui. Aside from the well-documented effects of RAPA on cell division and immunologic response, the literature reveals it to have negative effects on adipocyte and osteocyte differentiation as well. Understanding of the molecular effects of RAPA on cell differentiation is fragmentary in regard to these cell lineages. In this paper, we exam...

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

    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. PMID:27117918

  14. Suppression of Adipocyte Differentiation by Foenumoside B from Lysimachia foenum-graecum Is Mediated by PPARγ Antagonism

    Kwak, Hyun Jeong; Choi, Hye-Eun; Jang, Jinsun; Park, Soo Kyoung; Cho, Byoung Heon; Kim, Seul Ki; Lee, Sunyi; Kang, Nam Sook; Cheon, Hyae Gyeong

    2016-01-01

    Lysimachia foenum-graecum extract (LFE) and its active component foenumoside B (FSB) have been shown to inhibit adipocyte differentiation, but their mechanisms were poorly defined. Here, we investigated the molecular mechanisms responsible for their anti-adipogenic effects. Both LFE and FSB inhibited the differentiation of 3T3-L1 preadipocytes induced by peroxisome proliferator-activated receptor-γ (PPARγ) agonists, accompanied by reductions in the expressions of the lipogenic genes aP2, CD36, and FAS. Moreover, LFE and FSB inhibited PPARγ transactivation activity with IC50s of 22.5 μg/ml and 7.63 μg/ml, respectively, and showed selectivity against PPARα and PPARδ. Rosiglitazone-induced interaction between PPARγ ligand binding domain (LBD) and coactivator SRC-1 was blocked by LFE or FSB, whereas reduced NCoR-1 binding to PPARγ by rosiglitazone was reversed in the presence of LFE or FSB. In vivo administration of LFE into either ob/ob mice or KKAy mice reduced body weights, and levels of PPARγ and C/EBPα in fat tissues. Furthermore, insulin resistance was ameliorated by LFE treatment, with reduced adipose tissue inflammation and hepatic steatosis. Thus, LFE and FSB were found to act as PPARγ antagonists that improve insulin sensitivity and metabolic profiles. We propose that LFE and its active component FSB offer a new therapeutic strategy for metabolic disorders including obesity and insulin resistance. PMID:27176632

  15. RPL13A and EEF1A1 Are Suitable Reference Genes for qPCR during Adipocyte Differentiation of Vascular Stromal Cells from Patients with Different BMI and HOMA-IR

    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

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

    Ambele, Melvin Anyasi; Dessels, Carla; Durandt, Chrisna; Pepper, Michael Sean

    2016-05-01

    We have undertaken an in-depth transcriptome analysis of adipogenesis in human adipose-derived stromal cells (ASCs) induced to differentiate into adipocytes in vitro. Gene expression was assessed on days 1, 7, 14 and 21 post-induction and genes differentially expressed numbered 128, 218, 253 and 240 respectively. Up-regulated genes were associated with blood vessel development, leukocyte migration, as well as tumor growth, invasion and metastasis. They also shared common pathways with certain obesity-related pathophysiological conditions. Down-regulated genes were enriched for immune response processes. KLF15, LMO3, FOXO1 and ZBTB16 transcription factors were up-regulated throughout the differentiation process. CEBPA, PPARG, ZNF117, MLXIPL, MMP3 and RORB were up-regulated only on days 14 and 21, which coincide with the maturation of adipocytes and could possibly serve as candidates for controlling fat accumulation and the size of mature adipocytes. In summary, we have identified genes that were up-regulated only on days 1 and 7 or days 14 and 21 that could serve as potential early and late-stage differentiation markers. PMID:27108396

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

    Melvin Anyasi Ambele

    2016-05-01

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

  18. Seapolynol Extracted from Ecklonia cava Inhibits Adipocyte Differentiation in Vitro and Decreases Fat Accumulation in Vivo

    Hui-Jeon Jeon

    2015-12-01

    Full Text Available Seapolynol (SN is a polyphenol mixture derived from Ecklonia cava. We evaluated the effects of SN on lipid accumulation in adipocytes, zebrafish, and mice. SN effectively inhibited lipid accumulation in three experimental models by suppressing adipogenic factors. Triglyceride synthetic enzymes such as diacylglycerol acyltransferase 1 (DGAT1 and GPAT3 were also downregulated by SN. This SN-induced inhibition of adipogenic factors was shown to be due to the regulatory effect of SN on early adipogenic factors; SN downregulated the expression of Krueppel-like factor 4 (KLF4, KLF5, CCAAT-enhancer-binding protein β (C/EBPβ, C/EBPδ, and Protein C-ets-2 (ETS2, while KLF2, an anti-early adipogenic factor, was upregulated by SN. SN-mediated inhibition in early adipogenesis was closely correlated with the inhibition of mitotic clonal expansion via cell cycle arrest. SN inhibited cell cycle progression by suppressing cell cycle regulators, such as cyclin A, cyclinD, and pRb but increased p27, a cell cycle inhibitor. In a mouse study, SN effectively reduced body weight and plasma lipid increases induced by a high-fat diet; triglycerides, total cholesterol, and low-density lipoprotein (LDL levels were markedly reduced by SN. Moreover, SN remarkably improved high-fat-diet-induced hepatic lipid accumulation. Furthermore, SN activated AMP-activated protein kinase-α (AMPKα, an energy sensor, to suppress acetyl-coA carboxylase (ACC, inhibiting lipid synthesis. Our study suggests that SN may be an edible agent that can play a positive role in prevention of metabolic disorders.

  19. Seapolynol Extracted from Ecklonia cava Inhibits Adipocyte Differentiation in Vitro and Decreases Fat Accumulation in Vivo.

    Jeon, Hui-Jeon; Choi, Hyeon-Son; Lee, Yeon-Joo; Hwang, Ji-Hyun; Lee, Ok-Hwan; Seo, Min-Jung; Kim, Kui-Jin; Lee, Boo-Yong

    2015-01-01

    Seapolynol (SN) is a polyphenol mixture derived from Ecklonia cava. We evaluated the effects of SN on lipid accumulation in adipocytes, zebrafish, and mice. SN effectively inhibited lipid accumulation in three experimental models by suppressing adipogenic factors. Triglyceride synthetic enzymes such as diacylglycerol acyltransferase 1 (DGAT1) and GPAT3 were also downregulated by SN. This SN-induced inhibition of adipogenic factors was shown to be due to the regulatory effect of SN on early adipogenic factors; SN downregulated the expression of Krueppel-like factor 4 (KLF4), KLF5, CCAAT-enhancer-binding protein β (C/EBPβ), C/EBPδ, and Protein C-ets-2 (ETS2), while KLF2, an anti-early adipogenic factor, was upregulated by SN. SN-mediated inhibition in early adipogenesis was closely correlated with the inhibition of mitotic clonal expansion via cell cycle arrest. SN inhibited cell cycle progression by suppressing cell cycle regulators, such as cyclin A, cyclinD, and pRb but increased p27, a cell cycle inhibitor. In a mouse study, SN effectively reduced body weight and plasma lipid increases induced by a high-fat diet; triglycerides, total cholesterol, and low-density lipoprotein (LDL) levels were markedly reduced by SN. Moreover, SN remarkably improved high-fat-diet-induced hepatic lipid accumulation. Furthermore, SN activated AMP-activated protein kinase-α (AMPKα), an energy sensor, to suppress acetyl-coA carboxylase (ACC), inhibiting lipid synthesis. Our study suggests that SN may be an edible agent that can play a positive role in prevention of metabolic disorders. PMID:26690099

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

    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. PMID:26494623

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

    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. PMID:27181211

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

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

    2002-01-01

    Osteoblasts and adipocytes share a common precursor cell in the bone marrow stroma, termed marrow stromal cell (MSC). As the volume of bone adipose tissue increases in vivo with age, we hypothesized that decreased bone formation observed during aging and in patients with osteoporosis (OP) is the...... result of enhanced adipogenesis and decreased osteoblastogenesis from the MSCs. Thus, cultures of MSCs were established from young donors (age 18-42, n = 34), elderly healthy donors (age 66-78, n = 20), and patients with OP (age 58-76, n = 15). Cells were cultured for 2 weeks in an adipogenic medium...... phosphatase (AP+), and adipocytic colonies containing adipocytes (Ad+) were quantitated. In addition, steady state mRNA levels of gene markers of adipocytic and osteoblastic phenotypes were determined using reverse-transcriptase polymerase chain reaction (RT-PCR). The adipogenic and osteogenic media induced...

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

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

    1983-01-01

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

  4. Amber Light (590 nm) Induces the Breakdown of Lipid Droplets through Autophagy-Related Lysosomal Degradation in Differentiated Adipocytes.

    Choi, Min Sik; Kim, Hyoung-June; Ham, Mira; Choi, Dong-Hwa; Lee, Tae Ryong; Shin, Dong Wook

    2016-01-01

    Lipolysis in the adipocytes provides free fatty acids for other tissues in response to the energy demand. With the rapid increase in obesity-related diseases, finding novel stimuli or mechanisms that regulate lipid metabolism becomes important. We examined the effects of visible light (410, 457, 505, 530, 590, and 660 nm) irradiation on lipolysis regulation in adipocytes differentiated from human adipose-derived stem cells (ADSCs). Interestingly, 590 nm (amber) light irradiation significantly reduced the concentration of lipid droplets (LDs). We further investigated the lipolytic signaling pathways that are involved in 590 nm light irradiation-induced breakdown of LDs. Immunoblot analysis revealed that 590 nm light irradiation-induced phosphorylation of hormone-sensitive lipase (HSL) was insufficient to promote reduction of LDs. We observed that 590 nm light irradiation decreased the expression of perilipin 1. We found that 590 nm light irradiation, but not 505 nm, induced conversion of LC3 I to LC3 II, a representative autophagic marker. We further demonstrated that the lysosomal inhibitors leupeptin/NH4Cl inhibited 590 nm light irradiation-induced reduction of LDs in differentiated adipocytes. Our data suggest that 590 nm light irradiation-induced LD breakdown is partially mediated by autophagy-related lysosomal degradation, and can be applied in clinical settings to reduce obesity. PMID:27346059

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

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

    2014-01-01

    microsomal triglyceride transfer protein (MTP), which we show is also under the transcriptional regulation of C/EBPβ and -δ, as a novel player in the presentation of endogenous lipid antigens by adipocytes. Overall, our findings indicate that adipocytes can function as non-professional lipid antigen...

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

    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

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

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

    2014-10-03

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

  8. Inhibition of acetyl-CoA carboxylases by soraphen A prevents lipid accumulation and adipocyte differentiation in 3T3-L1 cells.

    Cordonier, Elizabeth L; Jarecke, Sarah K; Hollinger, Frances E; Zempleni, Janos

    2016-06-01

    Acetyl-CoA carboxylases (ACC) 1 and 2 catalyze the carboxylation of acetyl-CoA to malonyl-CoA and depend on biotin as a coenzyme. ACC1 localizes in the cytoplasm and produces malonyl-CoA for fatty acid (FA) synthesis. ACC2 localizes in the outer mitochondrial membrane and produces malonyl-CoA that inhibits FA import into mitochondria for subsequent oxidation. We hypothesized that ACCs are checkpoints in adipocyte differentiation and tested this hypothesis using the ACC1 and ACC2 inhibitor soraphen A (SA) in murine 3T3-L1 preadipocytes. When 3T3-L1 cells were treated with 100nM SA for 8 days after induction of differentiation, the expression of PPARγ mRNA and FABP4 mRNA decreased by 40% and 50%, respectively, compared with solvent controls; the decrease in gene expression was accompanied by a decrease in FABP4 protein expression and associated with a decrease in lipid droplet accumulation. The rate of FA oxidation was 300% greater in SA-treated cells compared with vehicle controls. Treatment with exogenous palmitate restored PPARγ and FABP4 mRNA expression and FABP4 protein expression in SA-treated cells. In contrast, SA did not alter lipid accumulation if treatment was initiated on day eight after induction of differentiation. We conclude that loss of ACC1-dependent FA synthesis and loss of ACC2-dependent inhibition of FA oxidation prevent lipid accumulation in adipocytes and inhibit early stages of adipocyte differentiation. PMID:27041646

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

    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

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

    Yi-Jen Chen

    2011-11-01

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

  11. IGF-I is a mitogen involved in differentiation-related gene expression in fetal rat brown adipocytes

    1993-01-01

    Fetal rat brown adipocytes at time zero of culture constitute a population of cells of broad spectrum, as estimated by cell size, endogenous fluorescence and lipid content, and show an intrinsic mitogenic competence. They express constitutively early growth-related genes such as c-myc, c-fos, and beta-actin, tissue specific-genes such as the uncoupling protein (UCP) and the lipogenic marker malic enzyme (ME). Fetal brown adipocytes bear a high expression of insulin-like growth factor receptor...

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

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

    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 inc...

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

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

    2011-01-01

    Brown adipose tissue plays an important role in obesity, insulin resistance, and diabetes. We have previously shown that the transition from brown preadipocytes to mature adipocytes is mediated in part by insulin receptor substrate (IRS)-1 and the cell cycle regulator protein necdin. In this study...

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

    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

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

    Francisco Javier Ruiz-Ojeda

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

  16. SEC16A is a RAB10 effector required for insulin-stimulated GLUT4 trafficking in adipocytes.

    Bruno, Joanne; Brumfield, Alexandria; Chaudhary, Natasha; Iaea, David; McGraw, Timothy E

    2016-07-01

    RAB10 is a regulator of insulin-stimulated translocation of the GLUT4 glucose transporter to the plasma membrane (PM) of adipocytes, which is essential for whole-body glucose homeostasis. We establish SEC16A as a novel RAB10 effector in this process. Colocalization of SEC16A with RAB10 is augmented by insulin stimulation, and SEC16A knockdown attenuates insulin-induced GLUT4 translocation, phenocopying RAB10 knockdown. We show that SEC16A and RAB10 promote insulin-stimulated mobilization of GLUT4 from a perinuclear recycling endosome/TGN compartment. We propose RAB10-SEC16A functions to accelerate formation of the vesicles that ferry GLUT4 to the PM during insulin stimulation. Because GLUT4 continually cycles between the PM and intracellular compartments, the maintenance of elevated cell-surface GLUT4 in the presence of insulin requires accelerated biogenesis of the specialized GLUT4 transport vesicles. The function of SEC16A in GLUT4 trafficking is independent of its previously characterized activity in ER exit site formation and therefore independent of canonical COPII-coated vesicle function. However, our data support a role for SEC23A, but not the other COPII components SEC13, SEC23B, and SEC31, in the insulin stimulation of GLUT4 trafficking, suggesting that vesicles derived from subcomplexes of COPII coat proteins have a role in the specialized trafficking of GLUT4. PMID:27354378

  17. Adipocyte induced arterial calcification is prevented with sodium thiosulfate

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

    2014-06-20

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

  18. Adipocyte induced arterial calcification is prevented with sodium thiosulfate

    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

  19. 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

    Chia-Hua Liang

    2013-01-01

    Full Text Available 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.

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

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

    2010-01-01

    Both insulin and the cell death-inducing DNA fragmentation factor-α-like effector (CIDE) family play important roles in apoptosis and lipid droplet formation. However, regulation of the CIDE family by insulin and the contribution of the CIDE family to insulin actions remain unclear. Here, we investigated whether insulin regulates expression of the CIDE family and which subtypes contribute to insulin-induced anti-apoptosis and lipid droplet formation in human adipocytes. Insulin decreased CIDE...

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

    Rubén Cereijo

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

  2. Kruppel-like Factors(KLFs)and Adipocyte Differentiation%KLF转录因子家族与脂肪细胞分化

    张志威; 李辉; 王宁

    2009-01-01

    The Kruppel-like factors(KLFs) are a subfamily of zinc finger transcription factors. Three C2H2 zinc fingers at their C-terminus are characterized as a distinctive DNA-binding domain. KLFs are important eukaryotic transcription factors and implicated in the regulation of many biological processes, including cell proliferation, apoptosis, differentiation and embryo development. In recent years, KLFs have been shown to play vital roles during adipocyte differentiation. As proadipogenic factors, KLF4 activates the C/EBPβ (CCAAT- enhancer-binding protein β) expression in collaboration with Krox 20; KLF5 and KLF15 bind to and activate the PPARγ (peroxisome proliferator-activated receptor γ ) promoter; KLF6 facilitate adipogenesis by inhibiting the expression of PREF1 (pre-adipocyte factor 1) . As anti-adipogenic factors, KLF2 binds to and inhibit the activity of PPARγ promoter; KLF3 and C-terminal binding protein (CtBP) form a KLF3-CtBP complex and suppresses C/EBPα promoter; KLF7 inhibits the glucose transporter 2 (GLUT2) expression and adipocyte maturation. This review focuses to discuss the functions and molecular mechanisms of KLFs in adipocyte differentiation.%Kruppel样转录因子(Kruppel-like factors,KLF)是一类具有锌指结构的转录因子,其典型结构特征是在其羧基端具有3个C2H2锌指结构.KLF广泛参与细胞增殖、凋亡、分化以及胚胎发育等多个生命活动的调控.近年来脂肪细胞分化研究的结果显示,KLF家族的多个成员参与脂肪细胞分化过程的调控,既有促进脂肪细胞分化的,也有抑制脂肪细胞分化的.其中KLF4通过与Krox20协同作用,激活C/EBPβ(CCAAT-enhancer-binding protein β)基因表达,促进脂肪细胞分化;KLF5和KLF15都通过直接结合到氧化物酶增殖体激活受体γ(peroxisome proliferator-activated receptor γ,PPAR7)基因的启动子,激活PPARγ基因表达,促进脂肪细胞分化;而KLF6则通过抑制前脂肪细胞因子(pre-adipocyte factor

  3. Effects of low dose X-ray irradiation on proliferation and differentiation of mesenchymal stem cells derived from human umbilical cord into adipocytes and osteoblasts

    Objective: To observe the effects of low dose irradiation (LDR) on proliferation, adipogenesis and osteogenic potential of human umbilical cord mesenchymal stem cells (hucMSCs). Methods: hucMSCs were isolated from Wharton's jelly tissue of human umbilical cord by modified tissue piece inoculation, and flow cytometry was used to detect the expression of specific marker in the hucMSCs. The hucMSCs were randomly divided into two groups: irradiation group undergoing irradiation with the doses 50, 100, or 200 mGy respectively, and control group without irradiation. MTT method was applied to evaluate the proliferation of the hucMSCs at different time points with various doses irradiation. The third passage hucMSCs were randomly divided into two groups: irradiation group undergoing low dose irradiation of 200 mGy, and control group without irradiation,and then underwent induction by adipocytic and oesteocytic differentiation induction fluids respectively so as to differentiate into adipocytes and osteoblasts. Oil red O staining was used to detect the activity of alkaline phosphatase (ALP), and RT-PCR was used to detect the mRNA expression of core binding factor alpha 1 in human osteoblast. Results: After 9-12 days, fibroblasts began to swim out of the tissue piece with a confluence rate of 80% 2 weeks later. Within 7 days the absorption values of the hucMSCs undergoing different irradiation doses 2, 3, 4, 5, and 6 days later were all significantly higher than those of the control group (F=159.17, 448.81, 265.15, 183.93, and 181.83, all P<0.01), with the proliferation rates of the 100 mGy subgroup being the highest. After being induced liquid,vacuoles were observed in the irradiated group 2 days later. 21 days later, the adipogenic rates of irradiated group was significantly higher than that of the control group (t=28.25, P<0.01). The ALP activity increased in the irradiated group compared with control group (t=16.87, P<0.01). The expression level of Cbf-α1 mRNA was

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

    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.

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

    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 (αGs), assayed by radiolabeling in the presence of cholera toxin and [32P]NAD+, increased upon differentiation as previously described by others. The amounts of αGi and αGo assayed by radiolabeling in the presence of pertussis toxin and [32P]NAD+ 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 αGo and with one raised against theβ-subunit of the bovine rod-outer-segment G-protein, referred to as transducin. The immunoblotting data confirm the increase upon differentiation of αGo and also demonstrate an increase in the amount of the β-subunit. Thus differentiation of 3T3-L1 cells is accompanied by dramatic changes in the complexion of G-proteins in the membranes

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

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

    2011-01-01

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

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

    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

  8. Inflamed macrophage microvesicles induce insulin resistance in human adipocytes

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

    2015-01-01

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

  9. Mitochondrial Oxidative Phosphorylation Reserve Is Required for Hormone- and PPARγ Agonist-Induced Adipogenesis

    Ryu, Min Jeong; Kim, Soung Jung; Choi, Min Jeong; Kim, Yong Kyung; Lee, Min Hee; Lee, Seong Eun; Chung, Hyo Kyun; Jung, Saet Byel; Kim, Hyun-Jin; Kim, Koon Soon; Jo, Young Suk; Kweon, Gi Ryang; Lee, Chul-Ho; Shong, Minho

    2013-01-01

    Adipocyte differentiation requires the coordinated activities of several nuclear transcription factors. Recently, mitochondria biogenesis was reported to occur during adipocyte differentiation and following treatment with thiazolidinediones in vitro and in vivo. Crif1 is a translational factor for mitochondrial DNA (mtDNA) and is important for transcription of the mitochondrial oxidative phosphorylation (OXPHOS) complex. To investigate the role of OXPHOS in adipogenesis, we analyzed adipocyte...

  10. Factor XIII and adipocyte biology

    Mosher, Deane F.

    2014-01-01

    In this issue of Blood, Myneni et al demonstrate a role for the A (transglutaminase) subunit of factor XIII (FXIII-A) in cell culture models of differentiation of preadipocytes to adipocytes.1 This finding is potentially of great importance in light of recent genome-wide association and adipose tissue transcriptomic studies that implicated F13A1 in human obesity.2

  11. Separate developmental programs for HLA-A and -B cell surface expression during differentiation from embryonic stem cells to lymphocytes, adipocytes and osteoblasts.

    Hardee J Sabir

    Full Text Available A major problem of allogeneic stem cell therapy is immunologically mediated graft rejection. HLA class I A, B, and Cw antigens are crucial factors, but little is known of their respective expression on stem cells and their progenies. We have recently shown that locus-specific expression (HLA-A, but not -B is seen on some multipotent stem cells, and this raises the question how this is in other stem cells and how it changes during differentiation. In this study, we have used flow cytometry to investigate the cell surface expression of HLA-A and -B on human embryonic stem cells (hESC, human hematopoietic stem cells (hHSC, human mesenchymal stem cells (hMSC and their fully-differentiated progenies such as lymphocytes, adipocytes and osteoblasts. hESC showed extremely low levels of HLA-A and no -B. In contrast, multipotent hMSC and hHSC generally expressed higher levels of HLA-A and clearly HLA-B though at lower levels. IFNγ induced HLA-A to very high levels on both hESC and hMSC and HLA-B on hMSC. Even on hESC, a low expression of HLA-B was achieved. Differentiation of hMSC to osteoblasts downregulated HLA-A expression (P = 0.017. Interestingly HLA class I on T lymphocytes differed between different compartments. Mature bone marrow CD4(+ and CD8(+ T cells expressed similar HLA-A and -B levels as hHSC, while in the peripheral blood they expressed significantly more HLA-B7 (P = 0.0007 and P = 0.004 for CD4(+ and CD8(+ T cells, respectively. Thus different HLA loci are differentially regulated during differentiation of stem cells.

  12. FAT/CD36-mediated Long-Chain Fatty Acid Uptake in Adipocytes Requires Plasma Membrane Rafts

    Pohl, Jürgen; Ring, Axel; Korkmaz, Ümine; Ehehalt, Robert; Stremmel, Wolfgang

    2005-01-01

    We previously reported that lipid rafts are involved in long-chain fatty acid (LCFA) uptake in 3T3-L1 adipocytes. The present data show that LCFA uptake does not depend on caveolae endocytosis because expression of a dominant negative mutant of dynamin had no effect on uptake of [3H]oleic acid, whereas it effectively prevented endocytosis of cholera toxin. Isolation of detergent-resistant membranes (DRMs) from 3T3-L1 cell homogenates revealed that FAT/CD36 was expressed in both DRMs and deter...

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

    SHAN, Tizhong; Liu, Weiyi; Kuang, Shihuan

    2013-01-01

    Adipose tissues regulate metabolism, reproduction, and life span. The development and growth of adipose tissue are due to increases of both adipocyte cell size and cell number; the latter is mediated by adipocyte progenitors. Various markers have been used to identify either adipocyte progenitors or mature adipocytes. The fatty acid binding protein 4 (FABP4), commonly known as adipocyte protein 2 (aP2), has been extensively used as a marker for differentiated adipocytes. However, whether aP2 ...

  14. Antidiabetic Activities of Abutilon indicum (L. Sweet Are Mediated by Enhancement of Adipocyte Differentiation and Activation of the GLUT1 Promoter

    Chutwadee Krisanapun

    2011-01-01

    Full Text Available Abutilon indicum (L. Sweet is an Asian phytomedicine traditionally used to treat several disorders, including diabetes mellitus. However, molecular mechanisms supporting the antidiabetic effect of A. indicum L. remain unknown. The aim of this study was to evaluate whether extract of A. indicum L. improves insulin sensitivity. First, we observed the antidiabetic activity of aqueous extract of the entire plant (leaves, twigs and roots of A. indicum L. on postprandial plasma glucose in diabetic rats. The subsequent experiments revealed that butanol fractions of the extract bind to PPARγ and activate 3T3-L1 differentiation. To measure glucose uptake enhanced by insulin-like activity, we used rat diaphragm incubated with various concentrations of the crude extract and found that the extract enhances glucose consumption in the incubated solution. Our data also indicate that the crude extract and the fractions (water and butanol did not affect the activity of kinases involved in Akt and GSK-3β pathways; however, the reporter assay showed that the crude extract could activate glucose transporter 1 (GLUT1 promoter activity. These results suggest that the extract from A. indicum L. may be beneficial for reducing insulin resistance through its potency in regulating adipocyte differentiation through PPARγ agonist activity, and increasing glucose utilization via GLUT1.

  15. Antidiabetic Activities of Abutilon indicum (L.) Sweet Are Mediated by Enhancement of Adipocyte Differentiation and Activation of the GLUT1 Promoter.

    Krisanapun, Chutwadee; Lee, Seong-Ho; Peungvicha, Penchom; Temsiririrkkul, Rungravi; Baek, Seung Joon

    2011-01-01

    Abutilon indicum (L.) Sweet is an Asian phytomedicine traditionally used to treat several disorders, including diabetes mellitus. However, molecular mechanisms supporting the antidiabetic effect of A. indicum L. remain unknown. The aim of this study was to evaluate whether extract of A. indicum L. improves insulin sensitivity. First, we observed the antidiabetic activity of aqueous extract of the entire plant (leaves, twigs and roots) of A. indicum L. on postprandial plasma glucose in diabetic rats. The subsequent experiments revealed that butanol fractions of the extract bind to PPARγ and activate 3T3-L1 differentiation. To measure glucose uptake enhanced by insulin-like activity, we used rat diaphragm incubated with various concentrations of the crude extract and found that the extract enhances glucose consumption in the incubated solution. Our data also indicate that the crude extract and the fractions (water and butanol) did not affect the activity of kinases involved in Akt and GSK-3β pathways; however, the reporter assay showed that the crude extract could activate glucose transporter 1 (GLUT1) promoter activity. These results suggest that the extract from A. indicum L. may be beneficial for reducing insulin resistance through its potency in regulating adipocyte differentiation through PPARγ agonist activity, and increasing glucose utilization via GLUT1. PMID:21603234

  16. Separate Developmental Programs for HLA-A and -B Cell Surface Expression during Differentiation from Embryonic Stem Cells to Lymphocytes, Adipocytes and Osteoblasts

    Sabir, Hardee J; Nehlin, Jan O; Qanie, Diyako;

    2013-01-01

    A major problem of allogeneic stem cell therapy is immunologically mediated graft rejection. HLA class I A, B, and Cw antigens are crucial factors, but little is known of their respective expression on stem cells and their progenies. We have recently shown that locus-specific expression (HLA-A, but...... not -B) is seen on some multipotent stem cells, and this raises the question how this is in other stem cells and how it changes during differentiation. In this study, we have used flow cytometry to investigate the cell surface expression of HLA-A and -B on human embryonic stem cells (hESC), human...... hematopoietic stem cells (hHSC), human mesenchymal stem cells (hMSC) and their fully-differentiated progenies such as lymphocytes, adipocytes and osteoblasts. hESC showed extremely low levels of HLA-A and no -B. In contrast, multipotent hMSC and hHSC generally expressed higher levels of HLA-A and clearly HLA...

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

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

    2015-01-01

    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 c...

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

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

    1998-01-01

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

  19. MiR-21a-5p suppresses bisphenol A-induced pre-adipocyte differentiation by targeting map2k3 through MKK3/p38/MAPK.

    Xie, Xiuwen; Song, Jia; Li, Gang

    2016-04-22

    Childhood obesity is a metabolic disease characterized by accumulation of excessive fat. Bisphenol A (BPA), a potential obesogen compound, possesses an estrogen mimetic activity and endocrine disruption effect. MicroRNA-21a-5p (miR-21a-5p) is reported to regulate the adipogenic differentiation. Our study showed that miR-21a-5p overexpression significantly decreased the red lipid droplets and triglyceride level in BPA-induced 3T3-L1 cells. BPA induced the mRNA and protein expression levels of PPARγ, C/EBPα and adiponectin, and the induction was inhibited by miR-21a-5p mimics transfection. MiR-21a-5p mimics inhibited the GR activity, GR phosphorylation (S220, S21a-5p2, and S234), and the activation of p38/MAPK pathway, which are elevated by BPA treatment in 3T3-L1 cells. MiR-21a-5p overexpression inhibited the protein level of MKK3, but not in the mRNA level. Luciferase activity assay showed that miR-21a-5p directly targeted map2k3 3'-UTR. MKK3 overexpression attenuated the effect of miR-21a-5p mimics transfection on 3T3-L1 differentiation. We also assessed the body weight, fat mass and the content of serum lipid in rats subcutaneous injected with BPA and miR-21a-5p mimics. MiR-21a-5p overexpression attenuated BPA-induced obesity in vivo. These findings suggested that miR-21a-5p inhibited BPA induced adipocyte differentiation by targeting map2k3 through MKK3/p38/MAPK in 3T3-L1 cells, providing a potential therapeutic strategy for BPA induced obesity. PMID:26996129

  20. Cell surface heparan sulfate proteoglycans contribute to intracellular lipid accumulation in adipocytes

    Orlando Robert A

    2005-01-01

    Full Text Available Abstract Background Transport of fatty acids within the cytosol of adipocytes and their subsequent assimilation into lipid droplets has been thoroughly investigated; however, the mechanism by which fatty acids are transported across the plasma membrane from the extracellular environment remains unclear. Since triacylglycerol-rich lipoproteins represent an abundant source of fatty acids for adipocyte utilization, we have investigated the expression levels of cell surface lipoprotein receptors and their functional contributions toward intracellular lipid accumulation; these include very low density lipoprotein receptor (VLDL-R, low density lipoprotein receptor-related protein (LRP, and heparan sulfate proteoglycans (HSPG. Results We found that expression of these three lipoprotein receptors increased 5-fold, 2-fold, and 2.5-fold, respectively, during adipocyte differentiation. The major proteoglycans expressed by mature adipocytes are of high molecular weight (>500 kD and contain both heparan and chondroitin sulfate moieties. Using ligand binding antagonists, we observed that HSPG, rather than VLDL-R or LRP, play a primary role in the uptake of DiI-lableled apoE-VLDL by mature adipocytes. In addition, inhibitors of HSPG maturation resulted in a significant reduction (>85% in intracellular lipid accumulation. Conclusions These results suggest that cell surface HSPG is required for fatty acid transport across the plasma membrane of adipocytes.

  1. Buddleja officinalis Maximowicz Extract Inhibits Lipid Accumulation on Adipocyte Differentiation in 3T3-L1 Cells and High-Fat Mice

    Jin-Kyu Kim

    2012-07-01

    Full Text Available Obesity is a global health problem. It is also known to be a risk factor for the development of metabolic disorders, type 2 diabetes, systemic hypertension, cardiovascular disease, dyslipidemia, and atherosclerosis. In this study, we elucidated that Buddleja officinalis Maximowicz extract significantly inhibited lipid accumulation during 3T3-L1 adipocyte differentiation. Furthermore, Buddleja officinalis Maximowicz extract reduced the body weight gain induced through feeding a high-fat diet to C57BL/6 mice. The treatment of Buddleja officinalis Maximowicz extract significantly reduced the adipose tissue weight to 2.7/100 g of body weight in high-fat mice. When their adipose tissue morphology was investigated for histochemical staining, the distribution of cell size in the high-fat diet groups was hypertrophied compared with those from Buddleja officinalis Maximowicz extract-treated mice. In addition, in Buddleja officinalis Maximowicz extract-treated mice, a significant reduction of serum triglyceride and T-cholesterol was observed at to 21% and 17%, respectively. The discovery of bioactive compounds from diet or dietary supplementation is one of possible ways to control obesity and to prevent or reduce the risks of various obesity-related diseases. These results support that Buddleja officinalis Maximowicz extract is expected to create the therapeutic interest with respect to the treatment of obesity.

  2. Activation of peroxisome proliferator-activated receptor gamma bypasses the function of the retinoblastoma protein in adipocyte differentiation

    Hansen, Jacob B.; Petersen, R K; Larsen, B M;

    1999-01-01

    regulate transactivation by C/EBPbeta. We show that PPARgamma-mediated transactivation is pRB-independent, and that ligand-induced transactivation by PPARgamma1 present in RB+/+ and RB-/- mouse embryo fibroblasts is sufficient to bypass the differentiation block imposed by the absence of p...... exit from the cell cycle after completion of clonal expansion following stimulation with adipogenic inducers. We conclude that ligand-induced activation of endogenous PPARgamma1 in mouse embryo fibroblasts is sufficient to initiate a transcriptional cascade resulting in induction of PPARgamma2 and C....../EBPalpha expression, withdrawal from the cell cycle, and terminal differentiation in the absence of a functional pRB....

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

    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

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

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

    2014-08-08

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

  5. Necdin Controls Proliferation of White Adipocyte Progenitor Cells

    Fujiwara, Kazushiro; Hasegawa, Koichi; Ohkumo, Tsuyoshi; Miyoshi, Hiroyuki; Yoshikawa, Kazuaki; Tseng, Yu-Hua

    2012-01-01

    White adipose tissues are composed mainly of white fat cells (adipocytes), which play a key role in energy storage and metabolism. White adipocytes are terminally differentiated postmitotic cells and arise from their progenitor cells (preadipocytes) or mesenchymal stem cells residing in white adipose tissues. Thus, white adipocyte number is most likely controlled by the rate of preadipocyte proliferation, which may contribute to the etiology of obesity. However, little is known about the mole...

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

    Stenson, B. M.; Ryden, M; Venteclef, N.; Dahlman, I; Pettersson, A. M. L.; Mairal, A.; Astrom, G.; Blomqvist, L; Wang, V; Jocken, J. W. E.; Clement, K.; Langin, D.; Arner, P; Laurencikiene, J

    2010-01-01

    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 ...

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

    郭云涛; 苗向阳

    2015-01-01

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

  8. Transcriptional regulatory program in wild-type and retinoblastoma gene-deficient mouse embryonic fibroblasts during adipocyte differentiation

    Hakim-Weber, Robab; Krogsdam, Anne-M; Jørgensen, Claus;

    2011-01-01

    Although many molecular regulators of adipogenesis have been identified a comprehensive catalogue of components is still missing. Recent studies showed that the retinoblastoma protein (pRb) was expressed in the cell cycle and late cellular differentiation phase during adipogenesis. To investigate...... this dual role of pRb in the early and late stages of adipogenesis we used microarrays to perform a comprehensive systems-level analysis of the common transcriptional program of the classic 3T3-L1 preadipocyte cell line, wild-type mouse embryonic fibroblasts (MEFs), and retinoblastoma gene...... experimental data and computational analyses pinpointed a feedback-loop between Pparg and Foxo1.To analyze the effects of the retinoblastoma protein at the transcriptional level we chose a perturbated system (Rb-/- MEFs) for comparison to the transcriptional program of wild-type MEFs. Gene ontology analysis of...

  9. Modulating the Genomic Programming of Adipocytes

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

    2015-01-01

    transcriptional plasticity when exposed to physiological and metabolic stimuli. In our work, we have focused on understanding the processes responsible for modulating the genomic programming in response to different external signals. Thus, we have shown that browning of human adipocytes with rosiglitazone, an......, such as Krüppel-like factor 11 (KLF11) that are essential for modulating the genomic program in white adipocytes to induce browning. Furthermore, we have shown that acute suppression of adipocyte genes by the proinflammatory cytokine, tumor necrosis factor (TNF), involves redistribution of cofactors to......The ability to modify the transcriptional program in response to external signals provides a way for mammalian cells to alter their biological fate and properties, thereby adapting to changes in the environment. Adipocytes are excellent examples of differentiated cells that possess a striking...

  10. Pro-inflammatory phenotype of perivascular adipocytes: influence of high fat feeding

    Chatterjee, Tapan K.; Stoll, Lynn L.; Denning, Gerene M.; Harrelson, Allan; Blomkalns, Andra L; Idelman, Gila; Rothenberg, Florence G.; Neltner, Bonnie; Romig-Martin, Sara A.; Dickson, Eric W.; Rudich, Steven; Weintraub, Neal L.

    2009-01-01

    Adipose tissue depots originate from distinct precursor cells, are functionally diverse, and modulate disease processes in a depot-specific manner. However, the functional properties of perivascular adipocytes, and their influence on disease of the blood vessel wall, remain to be determined. We show that human coronary perivascular adipocytes exhibit a reduced state of adipocytic differentiation as compared with adipocytes derived from subcutaneous and visceral (perirenal) adipose depots. Sec...

  11. 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.

    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

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

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

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

    Mohamad Hafizi Abu Bakar

    2014-12-01

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

  14. Oleic acid enhances G protein coupled receptor 43 expression in bovine intramuscular adipocytes but not in subcutaneous adipocytes.

    Chung, K Y; Smith, S B; Choi, S H; Johnson, B J

    2016-05-01

    We hypothesized that fatty acids would differentially affect G protein coupled receptor (GPR) 43 mRNA expression and GPR43 protein concentrations in bovine intramuscular (IM) and subcutaneous (SC) adipocytes. The GPR43 protein was detected in bovine liver, pancreas, and semimembranosus (MUS) muscle in samples taken at slaughter. Similarly, GPR43 protein levels were similar in IM adipose tissue and SM muscle but was barely detectable in SC adipose tissue. Primary cultures of IM and SC stromal vascular cells were isolated from bovine adipose tissues. Oleic acid (100 μ) stimulated PPARγ gene expression and decreased stearoyl-CoA desaturase (SCD) gene expression but had no effect on GPR43 gene expression, which was readily detectable in both IM and SC adipocytes. Differentiation cocktail (Diff; 10 μ insulin, 4 μ dexamethasone, and 10 μ ciglitizone) stimulated CCAAT/enhancer-binding protein β (C/EBPβ) and PPARγ gene expression in SC but not IM adipocytes, but Diff increased SCD gene expression in both cell types. Linoleic acid (10 µ) increased PPARγ gene expression relative to Diff cocktail in SC adipocytes, whereas linoleic acid and α-linolenic decreased SCD gene expression relative to control adipocytes and adipocytes incubated with Diff ( < 0.05). Increasing concentrations of oleic acid (1, 10, 100, and 500 μM) increased GPR43 protein and mRNA expression in IM but not SC adipocytes. These data indicated that oleic acid alters mRNA and protein concentrations of GPR43 in bovine IM adipocytes. PMID:27285685

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

    Yukari Nakamura

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

  16. Adipocytes Secrete Leukotrienes

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

    2012-01-01

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

  17. Milk-derived tripeptides IPP (Ile-Pro-Pro and VPP (Val-Pro-Pro promote adipocyte differentiation and inhibit inflammation in 3T3-F442A cells.

    Subhadeep Chakrabarti

    Full Text Available Milk derived tripeptides IPP (Ile-Pro-Pro and VPP (Val-Pro-Pro have shown promise as anti-hypertensive agents due to their inhibitory effects on angiotensin converting enzyme (ACE. Due to the key inter-related roles of hypertension, chronic inflammation and insulin resistance in the pathogenesis of metabolic syndrome, there is growing interest in investigating established anti-hypertensive agents for their effects on insulin sensitivity and inflammation. In this study, we examined the effects of IPP and VPP on 3T3-F442A murine pre-adipocytes, a widely used model for studying metabolic diseases. We found that both IPP and VPP induced beneficial adipogenic differentiation as manifested by intracellular lipid accumulation, upregulation of peroxisome proliferator-activated receptor gamma (PPARγ and secretion of the protective lipid hormone adiponectin by these cells. The observed effects were similar to those induced by insulin, suggesting potential benefits in the presence of insulin resistance. IPP and VPP also inhibited cytokine induced pro-inflammatory changes such as reduction in adipokine levels and activation of the nuclear factor kappa B (NF-κB pathway. Taken together, our findings suggest that IPP and VPP exert insulin-mimetic adipogenic effects and prevent inflammatory changes in adipocytes, which may offer protection against metabolic disease.

  18. CD36 is required for myoblast fusion during myogenic differentiation

    Park, Seung-Yoon [Department of Biochemistry, College of Medicine, Dongguk University and Medical Institute of Dongguk University, Gyeongju 780-714 (Korea, Republic of); Yun, Youngeun [Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Kim, In-San, E-mail: iskim@knu.ac.kr [Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Biomedical Research Institute, Korea Institute Science and Technology, Seoul (Korea, Republic of)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer CD36 expression was induced during myogenic differentiation. Black-Right-Pointing-Pointer CD36 expression was localized in multinucleated myotubes. Black-Right-Pointing-Pointer The expression of myogenic markers is attenuated in CD36 knockdown C2C12 cells. Black-Right-Pointing-Pointer Knockdown of CD36 significantly inhibited myotube formation during differentiation. -- Abstract: Recently, CD36 has been found to be involved in the cytokine-induced fusion of macrophage. Myoblast fusion to form multinucleated myotubes is required for myogenesis and muscle regeneration. Because a search of gene expression database revealed the attenuation of CD36 expression in the muscles of muscular dystrophy patients, the possibility that CD36 could be required for myoblast fusion was investigated. CD36 expression was markedly up-regulated during myoblast differentiation and localized in multinucleated myotubes. Knockdown of endogenous CD36 significantly decreased the expression of myogenic markers as well as myotube formation. These results support the notion that CD36 plays an important role in cell fusion during myogenic differentiation. Our finding will aid the elucidation of the common mechanism governing cell-to-cell fusion in various fusion models.

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

    Bao G Vu

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

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

    Sager, R; Kovac, P.

    1982-01-01

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

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

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

    2013-01-01

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

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

    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

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

    Ferrante, Maria C. [Department of Veterinary Medicine and Animal Productions, Federico II University of Naples, Via Delpino 1, 80137 Naples (Italy); Amero, Paola; Santoro, Anna [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Monnolo, Anna [Department of Veterinary Medicine and Animal Productions, Federico II University of Naples, Via Delpino 1, 80137 Naples (Italy); Simeoli, Raffaele; Di Guida, Francesca [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Mattace Raso, Giuseppina, E-mail: mattace@unina.it [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Meli, Rosaria, E-mail: meli@unina.it [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy)

    2014-09-15

    Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) are highly lipophilic environmental contaminants that accumulate in lipid-rich tissues, such as adipose tissue. Here, we reported the effects induced by PCBs 101, 153 and 180, three of the six NDL-PCBs defined as indicators, on mature 3T3-L1 adipocytes. We observed an increase in lipid content, in leptin gene expression and a reduction of leptin receptor expression and signaling, when cells were exposed to PCBs, alone or in combination. These modifications were consistent with the occurrence of “leptin-resistance” in adipose tissue, a typical metabolic alteration related to obesity. Therefore, we investigated how PCBs affect the expression of pivotal proteins involved in the signaling of leptin receptor. We evaluated the PCB effect on the intracellular pathway JAK/STAT, determining the phosphorylation of STAT3, a downstream activator of the transcription of leptin gene targets, and the expression of SOCS3 and PTP1B, two important regulators of leptin resistance. In particular, PCBs 153 and 180 or all PCB combinations induced a significant reduction in pSTAT3/STAT3 ratio and an increase in PTP1B and SOCS3, evidencing an additive effect. The impairment of leptin signaling was associated with the reduction of AMPK/ACC pathway activation, leading to the increase in lipid content. These pollutants were also able to increase the transcription of inflammatory cytokines (IL-6 and TNFα). It is worthy to note that the PCB concentrations used are comparable to levels detectable in human adipose tissue. Our data strongly support the hypothesis that NDL-PCBs may interfere with the lipid metabolism contributing to the development of obesity and related diseases. - Highlights: • NDL-PCBs alter lipid content and metabolism in 3T3-L1 adipocytes. • Impairment of leptin signaling was induced by NDL-PCBs. • NDL-PCBs reduce AMPK and ACC activation. • NDL-PCBs induce the synthesis of pro-inflammatory cytokine by

  4. The two faces of reactive oxygen species (ROS) in adipocyte function and dysfunction.

    Castro, José Pedro; Grune, Tilman; Speckmann, Bodo

    2016-08-01

    White adipose tissue (WAT) is actively involved in the regulation of whole-body energy homeostasis via storage/release of lipids and adipokine secretion. Current research links WAT dysfunction to the development of metabolic syndrome (MetS) and type 2 diabetes (T2D). The expansion of WAT during oversupply of nutrients prevents ectopic fat accumulation and requires proper preadipocyte-to-adipocyte differentiation. An assumed link between excess levels of reactive oxygen species (ROS), WAT dysfunction and T2D has been discussed controversially. While oxidative stress conditions have conclusively been detected in WAT of T2D patients and related animal models, clinical trials with antioxidants failed to prevent T2D or to improve glucose homeostasis. Furthermore, animal studies yielded inconsistent results regarding the role of oxidative stress in the development of diabetes. Here, we discuss the contribution of ROS to the (patho)physiology of adipocyte function and differentiation, with particular emphasis on sources and nutritional modulators of adipocyte ROS and their functions in signaling mechanisms controlling adipogenesis and functions of mature fat cells. We propose a concept of ROS balance that is required for normal functioning of WAT. We explain how both excessive and diminished levels of ROS, e.g. resulting from over supplementation with antioxidants, contribute to WAT dysfunction and subsequently insulin resistance. PMID:27031218

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

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

    2014-01-01

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

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

    Sinclair Andrew J

    2010-06-01

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

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

    Anne-Laure; Hafner; Christian; Dani

    2014-01-01

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

  8. CCAR1 is required for Ngn3-mediated endocrine differentiation

    Highlights: ► We identify CCAR1 to directly interact with Ngn3. ► CCAR1 is co-localized with Ngn3 in the nucleus. ► CCAR1 cooperates with Ngn3 in activating NeuroD expression. ► CCAR1 is required for Ngn3-mediated PANC-1 transdifferentiation. -- Abstract: Neurogenin3 (Ngn3) is a basic helix-loop-helix transcription factor that specifies pancreatic endocrine cell fates during pancreas development. It can also initiate a transdifferentiation program when expressed in pancreatic exocrine and ductal cells. However, how Ngn3 initiates a transcriptional cascade to achieve endocrine differentiation is still poorly understood. Here, we show that cell cycle and apoptosis regulator 1 (CCAR1), which is a transcriptional coactivator for nuclear receptors, also interacts with Ngn3. The association between Ngn3 and CCAR1 was verified by pull-down assays and co-immunoprecipitation analyses. Using gene reporter assays, we found that CCAR1 is essential for Ngn3 to activate the expression of the reporter genes containing the NeuroD promoter. Moreover, down-regulation of endogenous CCAR1 in the PANC-1 pancreatic ductal cell line inhibits the transdifferentiation program initiated by Ngn3. CCAR1 is, therefore, a novel partner of Ngn3 in mediating endocrine differentiation.

  9. Physiological Response of Adipocytes to Weight Loss and Maintenance

    Verhoef, Sanne P. M.; Camps, Stefan G. J. A.; Bouwman, Freek G.; Mariman, Edwin C. M.; Westerterp, Klaas R.

    2013-01-01

    Background Metabolic processes in adipose tissue are dysregulated in obese subjects and, in response to weight loss, either normalize or change in favor of weight regain. Objective To determine changes in adipocyte glucose and fatty acid metabolism in relation to changes in adipocyte size during weight loss and maintenance. Methods Twenty-eight healthy subjects (12 males), age 20–50 y, and BMI 28–35 kg/m2, followed a very low energy diet for 2 months, followed by a 10-month period of weight maintenance. Body weight, body composition (deuterium dilution and BodPod), protein levels (Western blot) and adipocyte size were assessed prior to and after weight loss and after the 10-month follow-up. Results A 10% weight loss resulted in a 16% decrease in adipocyte size. A marker for glycolysis decreased (AldoC) during weight loss in association with adipocyte shrinking, and remained decreased during follow-up in association with weight maintenance. A marker for fatty acid transport increased (FABP4) during weight loss and remained increased during follow-up. Markers for mitochondrial beta-oxidation (HADHsc) and lipolysis (ATGL) were only increased after the 10-month follow-up. During weight loss HADHsc and ATGL were coordinately regulated, which became weaker during follow-up due to adipocyte size-related changes in HADHsc expression. AldoC was the major denominator of adipocyte size and body weight, whereas changes in ATGL during weight loss contributed to body weight during follow-up. Upregulation of ATGL and HADHsc occured in the absence of a negative energy balance and was triggered by adipocyte shrinkage or indicated preadipocyte differentiation. Conclusion Markers for adipocyte glucose and fatty acid metabolism are changed in response to weight loss in line with normalization from a dysregulated obese status to an improved metabolic status. Trial Registration ClinicalTrials.gov NCT01015508 PMID:23505452

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

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

    2014-05-15

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

  11. Angiotensin II activates different calcium signaling pathways in adipocytes.

    Dolgacheva, Lyudmila P; Turovskaya, Maria V; Dynnik, Vladimir V; Zinchenko, Valery P; Goncharov, Nikolay V; Davletov, Bazbek; Turovsky, Egor A

    2016-03-01

    Angiotensin II (Ang II) is an important mammalian neurohormone involved in reninangiotensin system. Ang II is produced both constitutively and locally by RAS systems, including white fat adipocytes. The influence of Ang II on adipocytes is complex, affecting different systems of signal transduction from early Са(2+) responses to cell proliferation and differentiation, triglyceride accumulation, expression of adipokine-encoding genes and adipokine secretion. It is known that white fat adipocytes express all RAS components and Ang II receptors (АТ1 and АТ2). The current work was carried out with the primary white adipocytes culture, and Са(2+) signaling pathways activated by Ang II were investigated using fluorescent microscopy. Са(2+)-oscillations and transient responses of differentiated adipocytes to Ang II were registered in cells with both small and multiple lipid inclusions. Using inhibitory analysis and selective antagonists, we now show that Ang II initiates periodic Са(2+)-oscillations and transient responses by activating АТ1 and АТ2 receptors and involving branched signaling cascades:In these cascades, AT1 receptors play the leading role. The results of the present work open a perspective of using Ang II for correction of signal resistance of adipocytes often observed during obesity and type 2diabetes. PMID:26850364

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

    Liu, Ping, E-mail: lping@sdu.edu.cn [Department of Cardiology, The Second Hospital of Shandong University, No. 247, Beiyuan Road, Shandong, Jinan 250033 (China); Kong, Feng; Wang, Jue [Central Laboratory, The Second Hospital of Shandong University, Shandong, Jinan 250033 (China); Lu, Qinghua [Department of Cardiology, The Second Hospital of Shandong University, No. 247, Beiyuan Road, Shandong, Jinan 250033 (China); Xu, Haijia [Department of Cardiology, Wendeng Central Hospital of Weihai City, Shandong, Weihai 264400 (China); Qi, Tonggang [Central Laboratory, The Second Hospital of Shandong University, Shandong, Jinan 250033 (China); Meng, Juan [Department of Cardiology, The Second Hospital of Shandong University, No. 247, Beiyuan Road, Shandong, Jinan 250033 (China)

    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

  13. PPARs and adipocyte function

    Christodoulides, Constantinos; Vidal-Puig, Antonio

    2010-01-01

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

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

    Abd Eldaim Mabrouk Attia

    2012-01-01

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

  15. Weighing in on Adipocyte Precursors

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

    2013-01-01

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

  16. WAT is a functional adipocyte?

    Church, Christopher; Horowitz, Mark; Rodeheffer, Matthew

    2012-01-01

    In vertebrates, adipose tissue is the main storage site for lipids within specialized lipid-laden mature adipocytes. While many species have evolved cells capable of lipid storage, the adipocyte represents a unique specialized cell involved in fuel storage, endocrine, nervous and immune function. However, the adipocytes are not the only cell type in mammals that can accumulate lipid droplets. The ectopic accumulation of lipid in non-adipose tissues including the liver, skeletal muscle, bone, ...

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

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

    2016-07-01

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

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

    Lizcano, Fernando; Vargas, Diana

    2016-01-01

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

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

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

    2016-09-28

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

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

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

    2011-04-22

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

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

    Kim, Nam Soo; Kim, Yoon-Jin [Department of Biology, Research Institute for Basic Science, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Cho, Si Young [R and D Center, Amore Pacific Corporation, Yongin-si, Gyeonggi-do 446-729 (Korea, Republic of); Lee, Tae Ryong, E-mail: trlee@amorepacific.com [R and D Center, Amore Pacific Corporation, Yongin-si, Gyeonggi-do 446-729 (Korea, Republic of); Kim, Sang Hoon, E-mail: shkim@khu.ac.kr [Department of Biology, Research Institute for Basic Science, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

    2013-09-27

    Highlights: •MRAP enhanced HSL expression. •ACTH-mediated MRAP reduced glycerol release. •PPARγ induced MRAP expression. •PPARγ bound to the MRAP promoter. -- Abstract: Adrenocorticotropic hormone (ACTH) in rodents decreases lipid accumulation and body weight. Melanocortin receptor 2 (MC2R) and MC2R accessory protein (MRAP) are specific receptors for ACTH in adipocytes. Peroxisome proliferator-activated receptor γ (PPARγ) plays a role in the transcriptional regulation of metabolic pathways such as adipogenesis and β-oxidation of fatty acids. In this study we investigated the transcriptional regulation of MRAP expression during differentiation of 3T3-L1 cells. Stimulation with ACTH affected lipolysis in murine mature adipocytes via MRAP. Putative peroxisome proliferator response element (PPRE) was identified in the MRAP promoter region. In chromatin immunoprecipitation and reporter assays, we observed binding of PPARγ to the MRAP promoter. The mutagenesis experiments showed that the −1209/−1198 region of the MRAP promoter could function as a PPRE site. These results suggest that PPARγ is required for transcriptional activation of the MRAP gene during adipogenesis, which contributes to understanding of the molecular mechanism of lipolysis in adipocytes.

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

    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

  3. Zfp423 Maintains White Adipocyte Identity through Suppression of the Beige Cell Thermogenic Gene Program.

    Shao, Mengle; Ishibashi, Jeff; Kusminski, Christine M; Wang, Qiong A; Hepler, Chelsea; Vishvanath, Lavanya; MacPherson, Karen A; Spurgin, Stephen B; Sun, Kai; Holland, William L; Seale, Patrick; Gupta, Rana K

    2016-06-14

    The transcriptional regulators Ebf2 and Prdm16 establish and maintain the brown and/or beige fat cell identity. However, the mechanisms operating in white adipocytes to suppress the thermogenic gene program and maintain an energy-storing phenotype are less understood. Here, we report that the transcriptional regulator Zfp423 is critical for maintaining white adipocyte identity through suppression of the thermogenic gene program. Zfp423 expression is enriched in white versus brown adipocytes and suppressed upon cold exposure. Doxycycline-inducible inactivation of Zfp423 in mature adipocytes, combined with β-adrenergic stimulation, triggers a conversion of differentiated adiponectin-expressing inguinal and gonadal adipocytes into beige-like adipocytes; this reprogramming event is sufficient to prevent and reverse diet-induced obesity and insulin resistance. Mechanistically, Zfp423 acts in adipocytes to inhibit the activity of Ebf2 and suppress Prdm16 activation. These data identify Zfp423 as a molecular brake on adipocyte thermogenesis and suggest a therapeutic strategy to unlock the thermogenic potential of white adipocytes in obesity. PMID:27238639

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

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

    2016-01-01

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

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

    Omar Abdul-Rahman

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

  6. The transcriptional basis of adipocyte development.

    Rosen, Evan D

    2005-07-01

    Adipogenesis is the developmental process by which a multipotent mesenchymal stem cell differentiates into a mature adipocyte. This process involves a highly regulated and coordinated cascade of transcription factors that together lead to the establishment of the differentiated state. In the presence of the correct hormonal cues, committed pre-adipocytes express the bZIP factors C/EBPb and C/EBPd. These factors in turn induce the expression of C/EBPa and peroxisome proliferator-activated receptor g (PPARg). C/EBPa and PPARg together promote differentiation by activating adipose-specific gene expression and by maintaining each others expression at high levels. We have investigated the relative contributions of PPARg and C/EBPa to adipogenesis by selectively ablating these genes in mouse embryonic fibroblasts (MEFs). MEFs that lack C/EBPa are able to undergo adipogenesis, but only when PPARg is ectopically expressed. Interestingly, these cells are not sensitive to the metabolic actions of insulin. By way of contrast, cells that lack PPARg are utterly incapable of adipogenic conversion, even when supplemented with high levels of C/EBPa. Our current investigations are centered on the identification of novel adipogenic transcription factors, utilizing a variety of techniques, ranging from BAC transgenics to computational approaches. These approaches will be discussed, along with the roles of some new transcriptional players in adipogenesis, including the O/E family of proteins. PMID:15936931

  7. Hematopoietic Differentiation Is Required for Initiation of Acute Myeloid Leukemia.

    Ye, Min; Zhang, Hong; Yang, Henry; Koche, Richard; Staber, Philipp B; Cusan, Monica; Levantini, Elena; Welner, Robert S; Bach, Christian S; Zhang, Junyan; Krivtsov, Andrei V; Armstrong, Scott A; Tenen, Daniel G

    2015-11-01

    Mutations in acute myeloid leukemia (AML)-associated oncogenes often arise in hematopoietic stem cells (HSCs) and promote acquisition of leukemia stem cell (LSC) phenotypes. However, as LSCs often share features of lineage-restricted progenitors, the relative contribution of differentiation status to LSC transformation is unclear. Using murine MLL-AF9 and MOZ-TIF2 AML models, we show that myeloid differentiation to granulocyte macrophage progenitors (GMPs) is critical for LSC generation. Disrupting GMP formation by deleting the lineage-restricted transcription factor C/EBPa blocked normal granulocyte formation and prevented initiation of AML. However, restoring myeloid differentiation in C/EBPa mutants with inflammatory cytokines reestablished AML transformation capacity. Genomic analyses of GMPs, including gene expression and H3K79me2 profiling in conjunction with ATAC-seq, revealed a permissive genomic environment for activation of a minimal transcription program shared by GMPs and LSCs. Together, these findings show that myeloid differentiation is a prerequisite for LSC formation and AML development, providing insights for therapeutic development. PMID:26412561

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

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

    2015-01-01

    CD24 is a glycophosphatidylinositol (GPI)-linked cell surface receptor that is involved in regulating the survival or differentiation of several different cell types. CD24 has been used to identify pre-adipocytes that are able to reconstitute white adipose tissue (WAT) in vivo. Moreover, we recently found that the dynamic upregulation of CD24 in vitro during early phases of adipogenesis is necessary for mature adipocyte development. To determine the role of CD24 in adipocyte development in vi...

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

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

    2012-01-01

    The phytotherapeutic protein stem bromelain (SBM) is used as an anti-obesity alternative medicine. We show at the cellular level that SBM irreversibly inhibits 3T3-L1 adipocyte differentiation by reducing adipogenic gene expression and induces apoptosis and lipolysis in mature adipocytes. At the molecular level, SBM suppressed adipogenesis by downregulating C/EBPα and PPARγ independent of C/EBPβ gene expression. Moreover, mRNA levels of adipocyte fatty acid-binding protein (ap2), fatty acid s...

  10. A novel preadipocyte cell line established from mouse adult mature adipocytes

    We have established a novel preadipocyte cell line from mouse adult mature adipocytes. The mature adipocytes were isolated from fat tissues by taking only the floating population of mature fat cells. The isolated mature adipocytes were de-differentiated into fibroblast-like cells. The in vitro studies showed that the cells could re-differentiate into mature adipocytes after over 20 passages. The in vivo transplantation study also demonstrated that the cells had the full potential to differentiate into mature adipocytes, which has not been shown for the 3T3-L1 preadipocyte cell line derived from mouse embryo. We have further analyzed the expression profile of key fat regulatory genes such as the peroxisome proliferator-activated receptorγ or CCAAT/enhancer-binding protein gene families. We conclude that our cell line could be used as a preferred alternative to 3T3-L1, potentially reflecting the characteristics of mature adipocytes more, since the cell line is actually derived from adult mature adipocytes

  11. Glucocorticoids increase adipocytes in muscle by affecting IL-4 regulated FAP activity.

    Dong, Yanjun; Silva, Kleiton Augusto Santos; Dong, Yanlan; Zhang, Liping

    2014-09-01

    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. PMID:24948596

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

    Fabiana Ariemma

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

  13. The EU electricity production structure requires a differentiated energy policy

    For the electricity production of the EU there are differentiated structures which are based on different natural conditions, political decisions and investments of past decades. It has long been struggled committed to the ''one and correct'' energy policy. But precisely because of the differences in the individual countries, a unified energy and climate policy for the EU is not the right way. Diversity is a strength, which quite the EU Commission considered. Increased understanding of the specifics in other countries should just apply the German politics and the public that all too often judges from their own perspective.

  14. Bmp2 Is Required for Odontoblast Differentiation and Pulp Vasculogenesis

    Yang, W; Harris, M.A.; Y. Cui; Mishina, Y; Harris, S.E.; Gluhak-Heinrich, J.

    2012-01-01

    Using the Bmp2 floxed/3.6Col1a1-Cre (Bmp2-cKOod) mouse model, we have observed severe defects in odontogenesis and dentin formation with the removal of the Bmp2 gene in early-polarizing odontoblasts. The odontoblasts in the Bmp2-cKOod do not mature properly and fail to form proper dentin with normal dentinal tubules and activate terminal differentiation, as reflected by decreased Osterix, Col1a1, and Dspp expression. There is less dentin, and the dentin is hypomineralized and patchy. We also ...

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

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

    2012-01-01

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

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

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

    2004-01-01

    PPAR (peroxisome-proliferator-activated receptor) gamma is expressed in brown and white adipose tissues and is involved in the control of differentiation and proliferation. Noradrenaline stimulates brown pre-adipocyte proliferation and brown adipocyte differentiation. The aim of the present study...... was thus to investigate the influence of noradrenaline on PPARgamma gene expression in brown adipocytes. In primary cultures of brown adipocytes, PPARgamma2 mRNA levels were 20-fold higher than PPARgamma1 mRNA levels. PPARgamma expression occurred during both the proliferation and the differentiation...

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

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

    2009-01-01

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

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

    Mesenchymal stem cells found in bone marrow stromal cells (BMSCs) are the common progenitors for both adipocyte and osteoblast. An increase in marrow adipogenesis is associated with age-related osteopenia and anemia. Both extracellular and intracellular Ca2+ ([Ca2+]o and [Ca2+]i) are versatile signaling molecules that are involved in the regulation of cell functions, including proliferation and differentiation. We have recently reported that upon treatment of BMSCs with insulin and dexamethasone, both high [Ca2+]o and high [Ca2+]i enhanced adipocyte accumulation, which suggested that increases in [Ca2+]o caused by bone resorption may accelerate adipocyte accumulation in aging and diabetic patients. In this study, we used primary mouse BMSCs to investigate the mechanisms by which high [Ca2+]o and high [Ca2+]i may enhance adipocyte accumulation. In the process of adipocyte accumulation, two important keys are adipocyte differentiation and the proliferation of BMSCs, which have the potential to differentiate into adipocytes. Use of MTT assay and real-time RT-PCR revealed that high [Ca2+]i (ionomycin)-dependent adipocyte accumulation is caused by enhanced proliferation of BMSCs but not enhanced differentiation into adipocytes. Using fura-2 fluorescence-based approaches, we showed that high [Ca2+]o (addition of CaCl2) leads to increases in [Ca2+]i. Flow cytometric methods revealed that high [Ca2+]o suppressed the phosphorylation of ERK independently of intracellular Ca2+. The inhibition of ERK by U0126 and PD0325901 enhanced the differentiation of BMSCs into adipocytes. These data suggest that increased extracellular Ca2+ provides the differentiation of BMSCs into adipocytes by the suppression of ERK activity independently of increased intracellular Ca2+, which results in BMSC proliferation. - Highlights: • Both high [Ca2+]o and high [Ca2+]i enhanced adipocyte accumulation in BMSCs. • High [Ca2+]i enhanced the proliferation of BMSCs but not adipocyte differentiation

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

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

    2015-02-20

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

  20. Effects of induced differentiation by high-glucose on the morphology and function of mitochondria in 3T3-L1 adipocytes%高糖诱导分化对3T3-L1成熟脂肪细胞线粒体形态和功能的影响

    张向君; 王秀芳; 鲍子超; 吴钦良; 王加林; 赵亚萍

    2012-01-01

    目的 观察高糖诱导分化对3T3-L1成熟脂肪细胞葡萄糖转运以及线粒体功能的影响.方法 3T3-L1前体脂肪细胞分别在含25 mmol/L葡萄糖(高糖组)及5 mmol/L葡萄糖(低糖组)的DMEM培养基中诱导分化.采用油红“O”染色法观察细胞的分化程度,采用液闪仪检测成熟脂肪细胞对[3H]-2-脱氧葡萄糖的摄取率,采用透射电镜观察脂肪细胞的线粒体形态,生物发光法检测脂肪细胞内ATP.结果 两组3T3-L1前体脂肪细胞均可分化为成熟脂肪细胞,高糖组成熟脂肪细胞体积及胞质内脂滴均较低糖组大;高糖组成熟脂肪细胞基础状态及胰岛素刺激下的葡萄糖摄取率均低于低糖组脂肪细胞;高糖组成熟脂肪细胞线粒体形态异常,细胞内ATP的含量为(63.00 ±2.48) nM/mg protein,低糖组为(102.00±1.39) nM/mg protein,两组比较,P<0.05.结论 采用含25mmoL/L或5 mmol/L葡萄糖的DMEM培养基培养,对3T3-L1前体脂肪细胞向成熟脂肪细胞的分化进程无明显影响;高糖诱导分化可致成熟脂肪细胞产生胰岛素抵抗和线粒体功能损伤.%Objective To explore the roles of induced differentiation by high-glucose on glucose transport and the function of mitochondria in mature 3T3-L1 adipocytes. Method 3T3-L1 preadipocytes were induced to differentiation in DMEM medium containing 25 mmol/L glucose (high-glucose group) or 5 mmol/L glucose (low-glucose group) , respectively. The differentiation process of 3T3-L1 adipocytes was examined by Oil red "0" straining. 2-Deoxy-[3H] glucose uptake in adipocytes was assayed by liquid-scintillation counting. The morphology of mitochondria in adipocytes was evaluated by transmission electron microscope. Bioluminescence was used to measure the ATP content of the adipocytes. Result 3T3-L1 preadipocytes of the two groups were successfully differentiated into mature adipocytes . The volume of mature adipocytes and the size of lipid droplet in endochylema were larger in

  1. Differential requirements for actin during yeast and mammalian endocytosis.

    Aghamohammadzadeh, Soheil; Ayscough, Kathryn R

    2009-08-01

    Key features of clathrin-mediated endocytosis have been conserved across evolution. However, endocytosis in Saccharomyces cerevisiae is completely dependent on a functional actin cytoskeleton, whereas actin appears to be less critical in mammalian cell endocytosis. We reveal that the fundamental requirement for actin in the early stages of yeast endocytosis is to provide a strong framework to support the force generation needed to direct the invaginating plasma membrane into the cell against turgor pressure. By providing osmotic support, pressure differences across the plasma membrane were removed and this reduced the requirement for actin-bundling proteins in normal endocytosis. Conversely, increased turgor pressure in specific yeast mutants correlated with a decreased rate of endocytic patch invagination. PMID:19597484

  2. Effects of Two Different Rhodiola rosea Extracts on Primary Human Visceral Adipocytes

    Elena Pomari

    2015-05-01

    Full Text Available Rhodiola rosea (Rro has been reported to have various pharmacological properties, including anti-fatigue, anti-stress and anti-inflammatory activity. It is also known to improve glucose and lipid metabolism, but the effects of Rhodiola rosea on adipocyte differentiation and metabolism are not still elucidated. In this study the anti-adipogenic and lipolytic activity of two extracts of Rhodiola rosea, containing 3% salidroside (RS or 1% salidroside and 3% rosavines (RR on primary human visceral adipocytes was investigated. Pre-adipocytes were analyzed after 10 and 20 days of treatment during differentiation and after 7 days of treatment when they reached mature shape. The RS extract significantly induced higher apoptosis and lipolysis in comparison to control cells and to RR extract. In contrast, RR extract significantly reduced triglyceride incorporation during maturation. Differentiation of pre-adipocytes in the presence of RS and RR extracts showed a significant decrease in expression of genes involved in adipocyte function such as SLC2A4 and the adipogenic factor FGF2 and significant increase in expression of genes involved in inhibition of adipogenesis, such as GATA3, WNT3A, WNT10B. Furthermore RR extract, in contrast to RS, significantly down-regulates PPARG, the master regulator of adipogenesis and FABP4. These data support the lipolytic and anti-adipogenetic activity of two different commercial extracts of Rhodiola rosea in primary human visceral pre-adipocytes during differentiation.

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

    Mei-Lin Wang

    2015-04-01

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

  4. Effect of glucocorticoids on the activity, expression and proximal promoter of type II deiodinase in rat brown adipocytes.

    Martinez-deMena, Raquel; Calvo, Rosa-Maria; Garcia, Laura; Obregon, Maria Jesus

    2016-06-15

    Triiodothyronine (T3) is important for thermogenesis in brown adipose tissue (BAT). Type II deiodinase (DIO2) produces T3 required for intracellular needs in BAT. Brown adipocytes in culture require T3 for the adrenergic stimulation of DIO2. Glucocorticoids induce adipocyte differentiation (lipogenesis). We investigated the regulation of DIO2 activity, Dio2 mRNA and Dio2 promoter activity by glucocorticoids in primary cultures of rat brown adipocytes using dexamethasone (DEX) and hydrocortisone (HC). DEX and HC regulated the adrenergic stimulation of DIO2 activity in a dose- and time-dependent manner, inhibiting DIO2 activity at short treatment times and large doses (1-10 μM) and stimulating DIO2 at low HC doses (1-100 nM) and longer times (DEX). Insulin depletion reduced DIO2 activity but the response to glucocorticoids remained unchanged. DEX and HC inhibited basal DIO2 activity. DEX had no effect on DIO2 half-life, whereas HC stabilized DIO2 activity. DEX and HC inhibited the adrenergic stimulation of Dio2 mRNA expression (100-10000 nM, 14-96 h), but stabilized Dio2 mRNA, particularly DEX. DEX increased basal Dio2 mRNA levels, possibly through stabilization of Dio2 mRNA. An 807 bp construct of the murine Dio2 proximal promoter showed maximal reporter activity, with the cAMP response element (CRE) essential for transcriptional activity. DEX caused inhibition in most constructs containing the CRE element whereas HC stimulated reporter activity in the 807 bp construct. Glucocorticoids inhibited the adrenergic stimulation of Dio2 at the transcriptional level in brown adipocytes, although DIO2 activity increased with HC, possibly due to stabilization of Dio2 activity and mRNA. The CRE and cEBP elements of the Dio2 promoter seem involved in the regulation by glucocorticoids. PMID:26994513

  5. Characterization of a primary brown adipocyte culture system derived from human fetal interscapular fat

    Seiler, Sarah E.; Xu, Dan; Ho, Jia-Pei; Lo, Kinyui Alice; Buehrer, Benjamin M; Ludlow, Y John W; Kovalik, Jean-Paul; Sun, Lei

    2015-01-01

    Brown fat has gained widespread attention as a potential therapeutic target to treat obesity and associated metabolic disorders. Indeed, the anti-obesity potential of multiple targets to stimulate both brown adipocyte differentiation and recruitment have been verified in rodent models. However, their therapeutic potential in humans is unknown due to the lack of a human primary brown adipocyte cell culture system. Likewise, the lack of a well-characterized human model has limited the discovery...

  6. Development of a 3D coculture system to study adipocyte and lymph node cell interactions

    Daya, S.; Loughlin, J.; MacQueen, H.

    2006-01-01

    We have developed a long term 3-dimensional coculture system with adipocytes and lymph node cells for the purpose of investigating interactions between these cells in vitro. Present experimental work with the culture system is aimed at introducing lymph node cells, in proportions similar to those found in intact lymph nodes, among differentiated adipocytes and observing interactions and the establishment of a spatial relationship between them. Co-cultures will be used to investigate the ly...

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

    Shizheng GAO; Changrong GE; Xi ZHANG; Yonggang LIU

    2007-01-01

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

  8. Differential effects of environmental chemicals and food contaminants on adipogenesis, biomarker release and PPARγ activation

    Taxvig, Camilla; Sørensen, Karin Dreisig; Boberg, Julie;

    2012-01-01

    differentiation although PPARγ activation is neither a requirement nor a guarantee for stimulation. Four out of the eleven chemicals (bisphenol A, mono-ethylhexyl phthalate, butylparaben, PCB 153) caused increased adipogenesis. The release of adipocyte-secreted hormones was sometimes but not always correlated...

  9. Clk/STY (cdc2-like kinase 1 and Akt regulate alternative splicing and adipogenesis in 3T3-L1 pre-adipocytes.

    Pengfei Li

    Full Text Available The development of adipocytes from their progenitor cells requires the action of growth factors signaling to transcription factors to induce the expression of adipogenic proteins leading to the accumulation of lipid droplets, induction of glucose transport, and secretion of adipokines signaling metabolic events throughout the body. Murine 3T3-L1 pre-adipocytes sequentially express all the proteins necessary to become mature adipocytes throughout an 8-10 day process initiated by a cocktail of hormones. We examined the role of Clk/STY or Clk1, a cdc2-like kinase, in adipogenesis since it is known to be regulated by Akt, a pivotal kinase in development. Inhibition of Clk1 by a specific inhibitor, TG003, blocked alternative splicing of PKCβII and expression of PPARγ1 and PPARγ2. SiRNA depletion of Clk1 resulted in early expression of PKCβII and sustained PKCβI expression. Since Clk1 is a preferred Akt substrate, required for phosphorylation of splicing factors, mutation of Clk1 Akt phosphorylation sites was undertaken. Akt sites on Clk1 are in the serine/arginine-rich domain and not the kinase domain. Mutation of single and multiple sites resulted in dysregulation of PKCβII, PKCβI, and PPARγ1&2 expression. Additionally, adipogenesis was blocked as assessed by Oil Red O staining, adiponectin, and Glut1 and 4 expression. Immunofluorescence microscopy revealed that Clk1 triple mutant cDNA, transfected into pre-adipocytes, resulted in excluding SRp40 (SFSR6 from co-localizing to the nucleus with PFS, a perispeckle specific protein. This study demonstrates the role of Akt and Clk1 kinases in the early differentiation of 3T3-L1 cells to adipocytes.

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

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

    2016-08-01

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

  11. Apelin Enhances Brown Adipogenesis and Browning of White Adipocytes.

    Than, Aung; He, Hui Ling; Chua, Si Hui; Xu, Dan; Sun, Lei; Leow, Melvin Khee-Shing; Chen, Peng

    2015-06-01

    Brown adipose tissue expends energy in the form of heat via the mitochondrial uncoupling protein UCP1. Recent studies showed that brown adipose tissue is present in adult humans and may be exploited for its anti-obesity and anti-diabetes actions. Apelin is an adipocyte-derived hormone that plays important roles in energy metabolism. Here, we report that apelin-APJ signaling promotes brown adipocyte differentiation by increasing the expressions of brown adipogenic and thermogenic transcriptional factors via the PI3K/Akt and AMPK signaling pathways. It is also found that apelin relieves the TNFα inhibition on brown adipogenesis. In addition, apelin increases the basal activity of brown adipocytes, as evidenced by the increased PGC1α and UCP1 expressions, mitochondrial biogenesis, and oxygen consumption. Finally, we provide both in vitro and in vivo evidence that apelin is able to increase the brown-like characteristics in white adipocytes. This study, for the first time, reveals the brown adipogenic and browning effects of apelin and suggests a potential therapeutic route to combat obesity and related metabolic disorders. PMID:25931124

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

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

  13. Lipid storage in large and small rat adipocytes by vesicle-associated glycosylphosphatidylinositol-anchored proteins.

    Müller, Günter; Wied, Susanne; Dearey, Elisabeth-Ann; Wetekam, Eva-Maria; Biemer-Daub, Gabriele

    2010-01-01

    Adipose tissue mass in mammals expands by increasing the average cell volume and/or total number of the adipocytes. Upregulated lipid storage in fully differentiated adipocytes resulting in their enlargement is well documented and thought to be a critical mechanism for the expansion of adipose tissue depots during the growth of both lean and obese animals and human beings. A novel molecular mechanism for the regulation of lipid storage and cell size in rat adipocytes was recently elucidated for the physiological stimuli, palmitate and H(2)O(2), and the antidiabetic sulfonylurea drug, glimepiride. It encompasses (1) the release of small vesicles, so-called adiposomes, harboring the glycosylphosphatidylinositol -anchored (c)AMP-degrading phosphodiesterase Gce1 and 5'-nucleotidase CD73 from donor adipocytes, (2) the transfer of the adiposomes and their interaction with detergent-insoluble glycolipid-enriched microdomains of the plasma membrane of acceptor adipocytes, (3) the translocation of Gce1 and CD73 from the adiposomes to the intracellular lipid droplets of the acceptor adipocytes, and (4) the degradation of (c)AMP at the lipid droplet surface zone by Gce1 and CD73 in the acceptor adipocytes, leading to the upregulation of the esterification of fatty acids into triacylglycerol s and the downregulation of their release from triacylglycerols. This mechanism may provide novel strategies for the therapy of metabolic diseases, such as type 2 diabetes and obesity. PMID:20865369

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

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

    2016-01-01

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

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

    Orlando Robert A

    2008-06-01

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

  16. Regional differences in porcine adipocytes isolated from skeletal muscle and adipose tissues as identified by a proteomic approach.

    Gondret, F; Guitton, N; Guillerm-Regost, C; Louveau, I

    2008-09-01

    The content and distribution of body lipids are of special interest for production efficiency and meat quality in the farm animal industry. Triglycerides represent the most variable fraction of tissue lipids, and are mainly stored in adipocytes. Although several studies have reported regional differences in the expression of genes and their products in adipocytes from various species, the characteristics of i.m. adipocytes remain poorly described. To evaluate adipocyte features according to muscle and other fat locations, adipocyte proteins were isolated from trapezius skeletal muscle, and intermuscular, s.c., or perirenal adipose tissues from 6 female pigs (80 d of age). Protein extracts were labeled and analyzed by 2-dimensional, fluorescent, differential gel electrophoresis. The comparisons revealed that 149 spots were always differentially expressed (P anabolic and energy-yielding catabolic pathways are downregulated in i.m. adipocytes compared with s.c., visceral, or intermuscular adipocytes, suggest that the metabolic activity of i.m. adipocytes is low. Thus, triggering adipogenesis rather than cell metabolism per se might be a valuable strategy to control lipid deposition in pig skeletal muscles. PMID:18310487

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

    Yaqin Chen

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

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

    Beth S Zha

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

  19. The Histone H2B Monoubiquitination Regulatory Pathway Is Required for Differentiation of Multipotent Stem Cells

    Karpiuk, Oleksandra; Najafova, Zeynab; Kramer, Frank;

    2012-01-01

    Extensive changes in posttranslational histone modifications accompany the rewiring of the transcriptional program during stem cell differentiation. However, the mechanisms controlling the changes in specific chromatin modifications and their function during differentiation remain only poorly...... understood. We show that histone H2B monoubiquitination (H2Bub1) significantly increases during differentiation of human mesenchymal stem cells (hMSCs) and various lineage-committed precursor cells and in diverse organisms. Furthermore, the H2B ubiquitin ligase RNF40 is required for the induction of...... during the transition from an inactive to an active chromatin conformation. Thus, these data indicate that H2Bub1 is required for maintaining multipotency of hMSCs and plays a central role in controlling stem cell differentiation....

  20. Characterisation of adipocyte-derived extracellular vesicles released pre- and post-adipogenesis

    Katherine D. Connolly

    2015-11-01

    Full Text Available Extracellular vesicles (EVs are submicron vesicles released from many cell types, including adipocytes. EVs are implicated in the pathogenesis of obesity-driven cardiovascular disease, although the characteristics of adipocyte-derived EVs are not well described. We sought to define the characteristics of adipocyte-derived EVs before and after adipogenesis, hypothesising that adipogenesis would affect EV structure, molecular composition and function. Using 3T3-L1 cells, EVs were harvested at day 0 and day 15 of differentiation. EV and cell preparations were visualised by electron microscopy and EVs quantified by nanoparticle tracking analysis (NTA. EVs were then assessed for annexin V positivity using flow cytometry; lipid and phospholipid composition using 2D thin layer chromatography and gas chromatography; and vesicular protein content by an immuno-phenotyping assay. Pre-adipogenic cells are connected via a network of protrusions and EVs at both time points display classic EV morphology. EV concentration is elevated prior to adipogenesis, particularly in exosomes and small microvesicles. Parent cells contain higher proportions of phosphatidylserine (PS and show higher annexin V binding. Both cells and EVs contain an increased proportion of arachidonic acid at day 0. PREF-1 was increased at day 0 whilst adiponectin was higher at day 15 indicating EV protein content reflects the stage of adipogenesis of the cell. Our data suggest that EV production is higher in cells before adipogenesis, particularly in vesicles <300 nm. Cells at this time point possess a greater proportion of PS (required for EV generation whilst corresponding EVs are enriched in signalling fatty acids, such as arachidonic acid, and markers of adipogenesis, such as PREF-1 and PPARγ.

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

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

    2012-01-01

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

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

    Yoko Yamada

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

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

    Nakamura Kumi

    2010-11-01

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

  4. The Effect of Crataegi Fructus Pharmacopuncture on Adipocyte Metabolism

    Seung Hwan, Won

    2008-06-01

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

  5. The effect of Spirodelae Herba Pharmacopuncture on Adipocyte Metabolism

    Sung Eon, Cho

    2008-03-01

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

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

    Takeo Iwata

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

  7. The polycomb group protein Suz12 is required for embryonic stem cell differentiation

    Pasini, Diego; Bracken, Adrian P; Hansen, Jacob Bo Højberg;

    2007-01-01

    results in early lethality of mouse embryos. Here, we demonstrate that Suz12(-/-) mouse embryonic stem (ES) cells can be established and expanded in tissue culture. The Suz12(-/-) ES cells are characterized by global loss of H3K27 trimethylation (H3K27me3) and higher expression levels of differentiation...... despite an increase in H3K27me3 levels is not always sufficient to prevent transcriptional activation. In summary, we demonstrate that Suz12 is required for the establishment of specific expression programs required for ES cell differentiation. Furthermore, we provide evidence that PcGs have different...

  8. Mechanisms that uncouple growth and differentiation in myeloid leukemia cells: restoration of requirement for normal growth-inducing protein without restoring induction of differentiation-inducing protein.

    Lotem, J; Sachs, L

    1982-01-01

    There are different macrophage- and granulocyte-inducing (MGI) proteins. Normal myeloid precursors are induced to multiply by one form (MGI-1) and to differentiate by another form (MGI-2). There are clones of myeloid leukemia cells that no longer require MGI-1 for growth but can still be induced to differentiate by MGI-2. After induction of differentiation in these leukemia cells by adding MCI-2 or inducing endogenous production of MGI-2 by lipopolysaccharide, the differentiating leukemia cel...

  9. Gene regulation in β-sitosterol-mediated stimulation of adipogenesis, glucose uptake, and lipid mobilization in rat primary adipocytes.

    Chai, Jen-Wai; Lim, Siang-Ling; Kanthimathi, M S; Kuppusamy, Umah Rani

    2011-05-01

    The nutraceutical benefits of β-sitosterol (SIT) are well documented. The present study investigated the in vitro effects of SIT on adipogenesis, glucose transport, and lipid mobilization in rat adipocytes. Primary cultures of rat preadipocytes and differentiated adipocytes were used in this study. Glucose uptake was measured by the uptake of radio-labeled glucose. Adipogenesis and lipolysis were measured by oil-red-O and glycerol quantification methods, respectively. The expression of protein kinase B (Akt), glucose transporter 4 (GLUT4), hormone sensitive lipase (HSL), and phosphatidylinositol-3-kinase (PI3 K) genes in SIT-treated adipocytes were assessed by real-time reverse transcription polymerase chain reaction (RT-PCR). The data showed that SIT induced glucose uptake in adipocytes. It also stimulated adipogenesis in differentiating preadipocytes. Interestingly, although SIT displayed general insulin-mimetic activity by stimulating glucose uptake and adipogenesis, it also induced lipolysis in adipocytes. Furthermore, the SIT-induced lipolysis was not attenuated by insulin and co-incubation of SIT with epinephrine improved epinephrine-induced lipolysis. GLUT4 gene expression was highly down-regulated in SIT-treated adipocytes, compared to insulin-treated adipocytes, which was up-regulated. Insulin- and SIT-treated adipocytes showed similar levels of Akt, HSL, and PI3 K gene down-regulation. These observations suggest that the elevation of glucose uptake in SIT-treated adipocytes was unrelated to de novo synthesis of GLUT4 and the SIT-induced lipolysis is associated with the down-regulation of Akt and PI3K genes. The unique effects of SIT on the regulation of glucose uptake, adipogenesis, and lipolysis in adipocytes show that it has potential to be utilized in diabetes and weight management. PMID:21484150

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

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

    2005-11-01

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

  11. ATF3 inhibits PPARγ-stimulated transactivation in adipocyte cells

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

    2015-01-02

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

  12. Maturin is a novel protein required for differentiation during primary neurogenesis

    Martinez-De Luna, Reyna I.; Ku, Ray Yueh; Lyou, Yung; Zuber, Michael E.

    2013-01-01

    Proliferation and differentiation are tightly controlled during neural development. In the embryonic neural plate, primary neurogenesis is driven by the proneural pathway. Here we report the characterization of Maturin, a novel, evolutionarily conserved protein that is required for normal primary neurogenesis. Maturin is detected throughout the early nervous system, yet it is most strongly expressed in differentiating neurons of the embryonic fish, frog and mouse nervous systems. Maturin expression can be induced by the proneural transcription factors Neurog2, Neurod1, and Ebf3. Maturin overexpression promotes neurogenesis, while loss-of-function inhibits the differentiation of neuronal progenitors, resulting in neural plate expansion. Maturin knockdown blocks the ability of Neurog2, Neurod1, and Ebf3 to drive ectopic neurogenesis. Maturin and Pak3, are both required for, and can synergize to promote differentiation of the primary neurons in vivo. Together, our results suggest that Maturin functions during primary neurogenesis and is required for the proneural pathway to regulate neural differentiation. PMID:24095902

  13. Adipocytes in Skin Health and Disease

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

    2014-01-01

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

  14. Adiponectin Inhibits Lipolysis in Mouse Adipocytes

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

    2011-01-01

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

  15. A temporal requirement for Hippo signaling in mammary gland differentiation, growth, and tumorigenesis

    Chen, Qian; Zhang, Nailing; Gray, Ryan S.; Li, Huili; Ewald, Andrew J.; Zahnow, Cynthia A.; Pan, Duojia

    2014-01-01

    In this study, Chen et al. discover that the Hippo pathway is functionally dispensable in virgin mammary glands but specifically required during pregnancy. YAP hyperactivation in mammary epithelia leads to defects in terminal differentiation. Loss of YAP causes no obvious defects in virgin mammary glands but potently suppresses oncogene-induced mammary tumors. This selective requirement for YAP in oncogenic growth suggests YAP inhibitors as targeted therapies against breast cancers.

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

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

    2010-01-01

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

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

    Pedro A Pérez-Mancera

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

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

    Colitti, Monica; Stefanon, Bruno

    2016-01-01

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

  19. Skin aging: are adipocytes the next target?

    Kruglikov, Ilja L; Scherer, Philipp E

    2016-07-01

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

  20. 替米沙坦对代谢综合征大鼠脂肪分化相关蛋白及肿瘤坏死因子-α表达影响%Effects of telmisartan on the expressions of adipocyte differentiation-related protein and tumor necrosis factor-α in rats with metabolic syndrome

    杨大春; 马双陶; 李强; 李秀川; 张继红; 李德; 杨永健

    2012-01-01

    目的 探讨替米沙坦对代谢综合征( metabolic syndrome,MS)大鼠脂肪分化相关蛋白(adipocyte differentiation-related protein,ADRP)及肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)表达的影响.方法 45只2月龄雄性Wistar大鼠随机分为普食对照组、MS组和MS+替米沙坦组(MS-Telm组)各15只,喂养6个月后测定3组空腹血糖、血脂、血清胰岛素水平,并计算胰岛素抵抗指数;评估睾周脂肪组织细胞形态的变化;应用蛋白免疫印迹法检测ADRP,TNF-α的表达.结果 与普食对照组比较,MS组及MS+ Telm组大鼠睾周脂肪组织质量、ADRP、TNF-α表达增加(P均<0.05),空腹血糖、血脂、血清空腹胰岛素及胰岛素抵抗指数水平增高(P<0.01);MS+Telm组大鼠血清空腹胰岛素水平、胰岛素抵抗指数、睾周脂肪组织质量、脂肪细胞面积、ADRP、TNF-α蛋白表达均较MS组降低(P<0.05).结论 替米沙坦可抑制MS大鼠脂肪组织TNF-α及ADRP的表达,减轻胰岛素抵抗.%Objective To observe the effects of telmisartan on the expressions of adipocyte differentiation-related protein (ADRP) and tumor necrosis factor-a (TNF-a) in adipose tissue from rats with metabolic syndrome (MS). Methods Forty-five 2-month-old male Wistar rats were divided into control group, MS group and MS plus telmisartan (MS+Telm) group, with 15 rats in each group. After 6 months of diet intervention, the levels of fasting lipids, glucose and insulin were measured. Insulin resistance index was calculated. The morphology of epididymal adipocytes was evaluated. The protein expressions of ADRP and TNF-a were detected with Western blot immunoassay. Results Compared with control group, the levels of epididymal fat mass, ADRP and TNF-a increased in MS group and MS+Telm group (P<0. 05), and the levels of fasting lipids, glucose, insulin and insulin resistance index increased significantly (P<0. 01). The plasma level of insulin, calculated insulin resistance index

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

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

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

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

    2011-04-15

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

  3. Glucocorticoids antagonize tumor necrosis factor-α-stimulated lipolysis and resistance to the antilipolytic effect of insulin in human adipocytes

    Lee, Mi-Jeong; Fried, Susan K.

    2012-01-01

    High concentrations of TNF within obese adipose tissue increase basal lipolysis and antagonize insulin signaling. Adipocytes of the obese are also exposed to elevated levels of glucocorticoids (GCs), which antagonize TNF actions in many cell types. We tested the hypothesis that TNF decreases sensitivity to the antilipolytic effect of insulin and that GCs antagonize this effect in differentiated human adipocytes. Lipolysis and expression levels of lipolytic proteins were measured after treatin...

  4. Gene regulation in β-sitosterol-mediated stimulation of adipogenesis, glucose uptake, and lipid mobilization in rat primary adipocytes

    Chai, Jen-Wai; Lim, Siang-Ling; Kanthimathi, M. S.; Kuppusamy, Umah Rani

    2010-01-01

    The nutraceutical benefits of β-sitosterol (SIT) are well documented. The present study investigated the in vitro effects of SIT on adipogenesis, glucose transport, and lipid mobilization in rat adipocytes. Primary cultures of rat preadipocytes and differentiated adipocytes were used in this study. Glucose uptake was measured by the uptake of radio-labeled glucose. Adipogenesis and lipolysis were measured by oil-red-O and glycerol quantification methods, respectively. The expression of protei...

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

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

  6. The transcription factor XBP1 is selectively required for eosinophil differentiation

    Bettigole, Sarah E.; Lis, Raphael; Adoro, Stanley; Lee, Ann-Hwee; Spencer, Lisa A.; Weller, Peter F.; Glimcher, Laurie H.

    2015-01-01

    The transcription factor XBP1 has been linked to the development of highly secretory tissues such as plasma cells and Paneth cells, yet its function in granulocyte maturation has remained unknown. Here we discovered an unexpectedly selective and absolute requirement for XBP1 in eosinophil differentiation without an effect on the survival of basophils or neutrophils. Progenitors of myeloid cells and eosinophils selectively activated the endoribonuclease IRE1α and spliced Xbp1 mRNA without inducing parallel endoplasmic reticulum (ER) stress signaling pathways. Without XBP1, nascent eosinophils exhibited massive defects in the post-translational maturation of key granule proteins required for survival, and these unresolvable structural defects fed back to suppress critical aspects of the transcriptional developmental program. Hence, we present evidence that granulocyte subsets can be distinguished by their differential reliance on secretory-pathway homeostasis. PMID:26147683

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

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

    2013-02-01

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

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

    Allison J. Richard

    2013-01-01

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

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

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

    2016-09-01

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

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

    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

  11. Quantitative analysis of secretome from adipocytes regulated by insulin

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

    2009-01-01

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

  12. Utx Is Required for Proper Induction of Ectoderm and Mesoderm during Differentiation of Embryonic Stem Cells

    Morales Torres, Cristina; Laugesen, Anne; Helin, Kristian

    2013-01-01

    Embryonic development requires chromatin remodeling for dynamic regulation of gene expression patterns to ensure silencing of pluripotent transcription factors and activation of developmental regulators. Demethylation of H3K27me3 by the histone demethylases Utx and Jmjd3 is important for the...... activation of lineage choice genes in response to developmental signals. To further understand the function of Utx in pluripotency and differentiation we generated Utx knockout embryonic stem cells (ESCs). Here we show that Utx is not required for the proliferation of ESCs, however, Utx contributes to the...

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

    Nobusue, Hiroyuki; Endo, Tsuyoshi; Kano, Koichiro

    2008-06-01

    We established a preadipocyte cell line from mature adipocytes obtained from subcutaneous fat tissue of green fluorescent protein (GFP) transgenic mice. The floating top layer, containing mature adipocytes, was isolated from subcutaneous fat tissue by collagenase digestion and filtration. Fluorescence-activated cell sorting and microscopic analysis revealed that the floating cell fraction comprised a highly homogeneous adipocyte population with no adipose stromal-vascular cells. Isolated mature adipocytes dedifferentiated into fibroblast-like cells and actively proliferated in ceiling culture. In vitro studies showed that the cells could redifferentiate into mature adipocytes in an identical way to 3T3-L1 preadipocytes. No changes in the differentiation pattern were observed during the propagation of our cells. They were successfully maintained and differentiated for at least 22 passages. We named these cells dedifferentiated fat (DFAT-GFP) cells. When DFAT-GFP cells were implanted subcutaneously into C57BL/6N mice, they developed highly vascularized fat pads that morphologically resembled normal subcutaneous adipose tissue and consisted of GFP-positive cells; however, implanted 3T3-L1 cells did not have such an effect on the mice. We conclude that DFAT-GFP cells provide a model that should enable us to study the mechanisms of adipocyte differentiation and adipose tissue formation in vivo and in vitro. PMID:18386066

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

    Stäb Franz

    2010-08-01

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

  15. Influence of epidermal growth factor (EGF) and hydrocortisone on the co-culture of mature adipocytes and endothelial cells for vascularized adipose tissue engineering.

    Huber, Birgit; Czaja, Alina Maria; Kluger, Petra Juliane

    2016-05-01

    The composition of vascularized adipose tissue is still an ongoing challenge as no culture medium is available to supply adipocytes and endothelial cells appropriately. Endothelial cell medium is typically supplemented with epidermal growth factor (EGF) as well as hydrocortisone (HC). The effect of EGF on adipocytes is discussed controversially. Some studies say it inhibits adipocyte differentiation while others reported of improved adipocyte lipogenesis. HC is known to have lipolytic activities, which might result in mature adipocyte dedifferentiation. In this study, we evaluated the influence of EGF and HC on the co-culture of endothelial cells and mature adipocytes regarding their cell morphology and functionality. We showed in mono-culture that high levels of HC promoted dedifferentiation and proliferation of mature adipocytes, whereas EGF seemed to have no negative influence. Endothelial cells kept their typical cobblestone morphology and showed a proliferation rate comparable to the control independent of EGF and HC concentration. In co-culture, HC promoted dedifferentiation of mature adipocytes, which was shown by a higher glycerol release. EGF had no negative impact on adipocyte morphology. No negative impact on endothelial cell morphology and functionality could be seen with reduced EGF and HC supplementation in co-culture with mature adipocytes. Taken together, our results demonstrate that reduced levels of HC are needed for co-culturing mature adipocytes and endothelial cells. In co-culture, EGF had no influence on mature adipocytes. Therefore, for the composition of vascularized adipose tissue constructs, the media with low levels of HC and high or low levels of EGF can be used. PMID:26888598

  16. Differential requirements for Gli2 and Gli3 in the regional specification of the mouse hypothalamus

    Roberta eHaddad-Tóvolli

    2015-03-01

    Full Text Available Secreted protein Sonic hedgehog (Shh ventralizes the neural tube by modulating the crucial balance between activating and repressing functions (GliA, GliR of transcription factors Gli2 and Gli3. This balance—the Shh-Gli code—is species- and context-dependent and has been elucidated for the mouse spinal cord. The hypothalamus, a forebrain region regulating vital functions like homeostasis and hormone secretion, shows dynamic and intricate Shh expression as well as complex regional differentiation. Here we asked if particular combinations of Gli2 and Gli3 and of GliA and GliR functions contribute to the variety of hypothalamic regions, i.e. we wanted to clarify the hypothalamic version of the Shh-Gli code. Based on mouse mutant analysis, we show that: 1 hypothalamic regional heterogeneity is based in part on differentially stringent requirements for Gli2 or Gli3; 2 another source of diversity are differential requirements for Shh of neural vs non-neural origin; 3 Gli2 is indispensable for the specification of a medial progenitor domain generating several essential hypothalamic nuclei plus the pituitary and median eminence; 4 the suppression of Gli3R by neural and non-neural Shh is essential for hypothalamic specification. Finally, we have mapped our results on a recent model which considers the hypothalamus as a transverse region with alar and basal portions. Our data confirm the model and are explained by it.

  17. Defective Differentiation of Adipose Precursor Cells from Lipodystrophic Mice Lacking Perilipin 1

    Ying Lyu; Xueying Su; Jingna Deng; Shangxin Liu; Liangqiang Zou; Xiaojing Zhao; Suning Wei; Bin Geng; Guoheng Xu

    2015-01-01

    Perilipin 1 (Plin1) localizes at the surface of lipid droplets to regulate triglyceride storage and hydrolysis in adipocytes. Plin1 defect leads to low adiposity in mice and partial lipodystrophy in human. This study investigated the roles of Plin1 in adipocyte differentiation. Plin1 null (-/-) mice showed plenty of multilocular adipocytes and small unilocular adipocytes in adipose tissue, along with lack of a subpopulation of adipose progenitor cells capable of in vivo adipogenesis and along...

  18. Cross species comparison of C/EBPa and PPAR¿ profiles in mouse and human adipocytes reveals interdependent retention of binding sites

    Sandelin Albin; Nielsen Ronni; Chen Yun; Jørgensen Mette; Schmidt Søren F; Mandrup Susanne

    2011-01-01

    Abstract Background The transcription factors peroxisome proliferator activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα) are key transcriptional regulators of adipocyte differentiation and function. We and others have previously shown that binding sites of these two transcription factors show a high degree of overlap and are associated with the majority of genes upregulated during differentiation of murine 3T3-L1 adipocytes. Results Here we have mapped all binding site...

  19. Real-time monitoring of inflammation status in 3T3-L1 adipocytes possessing a secretory Gaussia luciferase gene under the control of nuclear factor-kappa B response element

    Nagasaki, Haruka; Yoshimura, Takeshi [Department of Life Sciences, Graduate School of Bioresources, Mie University, Tsu 514-8507 (Japan); Aoki, Naohito, E-mail: n-aoki@bio.mie-u.ac.jp [Department of Life Sciences, Graduate School of Bioresources, Mie University, Tsu 514-8507 (Japan)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer Inflammation status in adipocytes can be monitored by the new assay system. Black-Right-Pointing-Pointer Only an aliquot of conditioned medium is required without cell lysis. Black-Right-Pointing-Pointer Inflammation-attenuating compounds can be screened more conveniently. -- Abstract: We have established 3T3-L1 cells possessing a secretory Gaussia luciferase (GLuc) gene under the control of nuclear factor-kappa B (NF-{kappa}B) response element. The 3T3-L1 cells named 3T3-L1-NF-{kappa}B-RE-GLuc could differentiate into adipocyte as comparably as parental 3T3-L1 cells. Inflammatory cytokines such as tumor necrosis factor (TNF)-{alpha} and interleukin (IL)-1{beta} induced GLuc secretion of 3T3-L1-NF-{kappa}B-RE-GLuc adipocytes in a concentration- and time-dependent manner. GLuc secretion of 3T3-L1-NF-{kappa}B-RE-GLuc adipocytes was also induced when cultured with RAW264.7 macrophages and was dramatically enhanced by lipopolysaccharide (LPS)-activated macrophages. An NF-{kappa}B activation inhibitor BAY-11-7085 and an antioxidant N-acetyl cysteine significantly suppressed GLuc secretion induced by macrophages. Finally, we found that rosemary-derived carnosic acid strongly suppressed GLuc secretion induced by macrophages and on the contrary up-regulated adiponectin secretion. Collectively, by using 3T3-L1-NF-{kappa}B-RE-GLuc adipocytes, inflammation status can be monitored in real time and inflammation-attenuating compounds can be screened more conveniently.

  20. Real-time monitoring of inflammation status in 3T3-L1 adipocytes possessing a secretory Gaussia luciferase gene under the control of nuclear factor-kappa B response element

    Highlights: ► Inflammation status in adipocytes can be monitored by the new assay system. ► Only an aliquot of conditioned medium is required without cell lysis. ► Inflammation-attenuating compounds can be screened more conveniently. -- Abstract: We have established 3T3-L1 cells possessing a secretory Gaussia luciferase (GLuc) gene under the control of nuclear factor-kappa B (NF-κB) response element. The 3T3-L1 cells named 3T3-L1-NF-κB-RE-GLuc could differentiate into adipocyte as comparably as parental 3T3-L1 cells. Inflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β induced GLuc secretion of 3T3-L1-NF-κB-RE-GLuc adipocytes in a concentration- and time-dependent manner. GLuc secretion of 3T3-L1-NF-κB-RE-GLuc adipocytes was also induced when cultured with RAW264.7 macrophages and was dramatically enhanced by lipopolysaccharide (LPS)-activated macrophages. An NF-κB activation inhibitor BAY-11-7085 and an antioxidant N-acetyl cysteine significantly suppressed GLuc secretion induced by macrophages. Finally, we found that rosemary-derived carnosic acid strongly suppressed GLuc secretion induced by macrophages and on the contrary up-regulated adiponectin secretion. Collectively, by using 3T3-L1-NF-κB-RE-GLuc adipocytes, inflammation status can be monitored in real time and inflammation-attenuating compounds can be screened more conveniently.

  1. 17β-Estradiol inhibition of PPARγ-induced adipogenesis and adipocyte-specific gene expression

    Jeong, Sunhyo; Yoon, Michung

    2011-01-01

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

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

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

    2013-01-01

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

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

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

    2010-01-01

    Cold adaptation elicits a paradoxical simultaneous induction of fatty acid synthesis and beta-oxidation in brown adipose tissue. We show here that cold exposure coordinately induced liver X receptor alpha (LXRalpha), adipocyte determination and differentiation-dependent factor 1 (ADD1)/sterol...... regulatory element-binding protein-1c (SREBP1c) and peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC1alpha) in brown and inguinal white adipose tissues, but not in epididymal white adipose tissue. Using in vitro models of white and brown adipocytes we demonstrate that beta...... regulator of PGC1alpha expression in brown adipose tissue....

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

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

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

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

    2011-11-11

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

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

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

    2012-01-01

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

  7. Medicine in Focus: Lipolysis in Adipocytes

    Ahmadian, Maryam; Wang, Yuhui; Sul, Hei Sook

    2009-01-01

    Lipolysis in adipocytes, the hydrolysis of triacylglycerol (TAG) to release fatty acids (FAs) and glycerol for use by other organs, is a unique function of white adipose tissue. Lipolysis in adipocytes occurs at the surface of cytosolic lipid droplets, which have recently gained much attention as dynamic organelles integral to lipid metabolism. Desnutrin/ATGL is now established as a bona fide TAG hydrolase and mutations in human desnutrin/ATGL/PNPLA2, as well as in its activator, comparative ...

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

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

    2016-01-01

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

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

    Takahashi, Nobuyuki; Goto, Tsuyoshi; Taimatsu, Aki; Egawa, Kahori; Katoh, Sota; Kusudo, Tatsuya; Sakamoto, Tomoya; Ohyane, Chie; Lee, Joo-Young; Kim, Young-il; Uemura, Taku; Hirai, Shizuka [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Kawada, Teruo, E-mail: fat@kais.kyoto-u.ac.jp [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan)

    2009-12-25

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

  10. Requirement of cAMP signaling for Schwann cell differentiation restricts the onset of myelination.

    Ketty Bacallao

    Full Text Available Isolated Schwann cells (SCs respond to cAMP elevation by adopting a differentiated post-mitotic state that exhibits high levels of Krox-20, a transcriptional enhancer of myelination, and mature SC markers such as the myelin lipid galactocerebroside (O1. To address how cAMP controls myelination, we performed a series of cell culture experiments which compared the differentiating responses of isolated and axon-related SCs to cAMP analogs and ascorbate, a known inducer of axon ensheathment, basal lamina formation and myelination. In axon-related SCs, cAMP induced the expression of Krox-20 and O1 without a concomitant increase in the expression of myelin basic protein (MBP and without promoting axon ensheathment, collagen synthesis or basal lamina assembly. When cAMP was provided together with ascorbate, a dramatic enhancement of MBP expression occurred, indicating that cAMP primes SCs to form myelin only under conditions supportive of basal lamina formation. Experiments using a combination of cell permeable cAMP analogs and type-selective adenylyl cyclase (AC agonists and antagonists revealed that selective transmembrane AC (tmAC activation with forskolin was not sufficient for full SC differentiation and that the attainment of an O1 positive state also relied on the activity of the soluble AC (sAC, a bicarbonate sensor that is insensitive to forskolin and GPCR activation. Pharmacological and immunological evidence indicated that SCs expressed sAC and that sAC activity was required for morphological differentiation and the expression of myelin markers such as O1 and protein zero. To conclude, our data indicates that cAMP did not directly drive myelination but rather the transition into an O1 positive state, which is perhaps the most critical cAMP-dependent rate limiting step for the onset of myelination. The temporally restricted role of cAMP in inducing differentiation independently of basal lamina formation provides a clear example of the

  11. Dynamics of Adipocyte Turnover in Humans

    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.

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

    Anja Böhm

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

  13. The effects of Hot Pepper Extract and Capsaicin on Adipocyte Metabolism

    Ching Sheng, Chu; Ki Rok, Kwon; Tae Jin, Rhim; Dong Heui, Kim

    2008-01-01

    Objectives : The purpose of this study is to investigate the effects of hot pepper extract and capsaicin on the adipogenesis in 3T3-L1 cells, lipolysis in rat epididymal adipocytes and histological changes in porcine adipose tissue. Methods : Inhibiton of preadipocyte differentiation and/or stimulation of lipolysis play important roles in reducing obesity. 3T3-L1 preadipocytes were differentiated with adipogenic reagents by incubating for 3 days in the absence or presence of hot pepper ...

  14. Small Buccal Fat Pad Cells Have High Osteogenic Differentiation Potential.

    Tsurumachi, Niina; Akita, Daisuke; Kano, Koichiro; Matsumoto, Taro; Toriumi, Taku; Kazama, Tomohiko; Oki, Yoshinao; Tamura, Yoko; Tonogi, Morio; Isokawa, Keitaro; Shimizu, Noriyoshi; Honda, Masaki

    2016-03-01

    Dedifferentiated fat (DFAT) cells derived from mature adipocytes have mesenchymal stem cells' (MSCs) characteristics. Generally, mature adipocytes are 60-110 μm in diameter; however, association between adipocyte size and dedifferentiation efficiency is still unknown. This study, therefore, investigated the dedifferentiation efficiency of adipocytes based on cell diameter. Buccal fat pad was harvested from five human donors and dissociated by collagenase digestion. After exclusion of unwanted stromal cells by centrifugation, floating adipocytes were collected and their size distribution was analyzed. The floating adipocytes were then separated into two groups depending on cell size using 40- and 100-μm nylon mesh filters: cell diameters less than 40 μm (small adipocytes: S-adipocytes) and cell diameters of 40-100 μm (large adipocytes: L-adipocytes). Finally, we evaluated the efficiency of adipocyte dedifferentiation and then characterized the resultant DFAT cells. The S-adipocytes showed a higher capacity to dedifferentiate into DFAT cells (S-DFAT cells) compared to the L-adipocytes (L-DFAT cells). The S-DFAT cells also showed a relatively higher proportion of CD146-positive cells than L-DFAT cells, and exhibited more osteogenic differentiation ability based on the alkaline phosphatase activity and amount of calcium deposition. These results suggested that the S- and L-DFAT cells had distinct characteristics, and that the higher dedifferentiation potential of S-adipocytes compared to L-adipocytes gives the former group an advantage in yielding DFAT cells. PMID:26651216

  15. A mex3 homolog is required for differentiation during planarian stem cell lineage development.

    Zhu, Shu Jun; Hallows, Stephanie E; Currie, Ko W; Xu, ChangJiang; Pearson, Bret J

    2015-01-01

    Neoblasts are adult stem cells (ASCs) in planarians that sustain cell replacement during homeostasis and regeneration of any missing tissue. While numerous studies have examined genes underlying neoblast pluripotency, molecular pathways driving postmitotic fates remain poorly defined. In this study, we used transcriptional profiling of irradiation-sensitive and irradiation-insensitive cell populations and RNA interference (RNAi) functional screening to uncover markers and regulators of postmitotic progeny. We identified 32 new markers distinguishing two main epithelial progenitor populations and a planarian homolog to the MEX3 RNA-binding protein (Smed-mex3-1) as a key regulator of lineage progression. mex3-1 was required for generating differentiated cells of multiple lineages, while restricting the size of the stem cell compartment. We also demonstrated the utility of using mex3-1(RNAi) animals to identify additional progenitor markers. These results identified mex3-1 as a cell fate regulator, broadly required for differentiation, and suggest that mex3-1 helps to mediate the balance between ASC self-renewal and commitment. PMID:26114597

  16. The AUXIN BINDING PROTEIN 1 is required for differential auxin responses mediating root growth.

    Alexandre Tromas

    Full Text Available BACKGROUND: In plants, the phytohormone auxin is a crucial regulator sustaining growth and development. At the cellular level, auxin is interpreted differentially in a tissue- and dose-dependent manner. Mechanisms of auxin signalling are partially unknown and the contribution of the AUXIN BINDING PROTEIN 1 (ABP1 as an auxin receptor is still a matter of debate. METHODOLOGY/PRINCIPAL FINDINGS: Here we took advantage of the present knowledge of the root biological system to demonstrate that ABP1 is required for auxin response. The use of conditional ABP1 defective plants reveals that the protein is essential for maintenance of the root meristem and acts at least on the D-type CYCLIN/RETINOBLASTOMA pathway to control entry into the cell cycle. ABP1 affects PLETHORA gradients and confers auxin sensitivity to root cells thus defining the competence of the cells to be maintained within the meristem or to elongate. ABP1 is also implicated in the regulation of gene expression in response to auxin. CONCLUSIONS/SIGNIFICANCE: Our data support that ABP1 is a key regulator for root growth and is required for auxin-mediated responses. Differential effects of ABP1 on various auxin responses support a model in which ABP1 is the major regulator for auxin action on the cell cycle and regulates auxin-mediated gene expression and cell elongation in addition to the already well known TIR1-mediated ubiquitination pathway.

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

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

    2014-03-14

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

  18. Adipocyte lipolysis and insulin resistance.

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

    2016-06-01

    Obesity-induced insulin resistance is a major risk factor for the development of type 2 diabetes. Basal fat cell lipolysis (i.e., fat cell triacylglycerol breakdown into fatty acids and glycerol in the absence of stimulatory factors) is elevated during obesity and is closely associated with insulin resistance. Inhibition of adipocyte lipolysis may therefore be a promising therapeutic strategy for treating insulin resistance and preventing obesity-associated type 2 diabetes. In this review, we explore the relationship between adipose lipolysis and insulin sensitivity. After providing an overview of the components of fat cell lipolytic machinery, we describe the hypotheses that may support the causality between lipolysis and insulin resistance. Excessive circulating fatty acids may ectopically accumulate in insulin-sensitive tissues and impair insulin action. Increased basal lipolysis may also modify the secretory profile of adipose tissue, influencing whole body insulin sensitivity. Finally, excessive fatty acid release may also worsen adipose tissue inflammation, a well-known parameter contributing to insulin resistance. Partial genetic or pharmacologic inhibition of fat cell lipases in mice as well as short term clinical trials using antilipolytic drugs in humans support the benefit of fat cell lipolysis inhibition on systemic insulin sensitivity and glucose metabolism, which occurs without an increase of fat mass. Modulation of fatty acid fluxes and, putatively, of fat cell secretory pattern may explain the amelioration of insulin sensitivity whereas changes in adipose tissue immune response do not seem involved. PMID:26542285

  19. Requirement for zebrafish ataxin-7 in differentiation of photoreceptors and cerebellar neurons.

    Constantin Yanicostas

    Full Text Available The expansion of a polyglutamine (polyQ tract in the N-terminal region of ataxin-7 (atxn7 is the causative event in spinocerebellar ataxia type 7 (SCA7, an autosomal dominant neurodegenerative disorder mainly characterized by progressive, selective loss of rod-cone photoreceptors and cerebellar Purkinje and granule cells. The molecular and cellular processes underlying this restricted neuronal vulnerability, which contrasts with the broad expression pattern of atxn7, remains one of the most enigmatic features of SCA7, and more generally of all polyQ disorders. To gain insight into this specific neuronal vulnerability and achieve a better understanding of atxn7 function, we carried out a functional analysis of this protein in the teleost fish Danio rerio. We characterized the zebrafish atxn7 gene and its transcription pattern, and by making use of morpholino-oligonucleotide-mediated gene inactivation, we analysed the phenotypes induced following mild or severe zebrafish atxn7 depletion. Severe or nearly complete zebrafish atxn7 loss-of-function markedly impaired embryonic development, leading to both early embryonic lethality and severely deformed embryos. More importantly, in relation to SCA7, moderate depletion of the protein specifically, albeit partially, prevented the differentiation of both retina photoreceptors and cerebellar Purkinje and granule cells. In addition, [1-232] human atxn7 fragment rescued these phenotypes showing strong function conservation of this protein through evolution. The specific requirement for zebrafish atxn7 in the proper differentiation of cerebellar neurons provides, to our knowledge, the first in vivo evidence of a direct functional relationship between atxn7 and the differentiation of Purkinje and granule cells, the most crucial neurons affected in SCA7 and most other polyQ-mediated SCAs. These findings further suggest that altered protein function may play a role in the pathophysiology of the disease, an

  20. A Serum Response Factor homolog is required for spore differentiation in Dictyostelium.

    Escalante, R; Sastre, L

    1998-10-01

    A homolog of the Serum Response Factor (SRF) has been isolated from Dictyostelium discoideum and its function studied by analyzing the consequences of its gene disruption. The MADS-box region of Dictyostelium SRF (DdSRF) is highly conserved with those of the human, Drosophila and yeast homologs. srfA is a developmentally regulated gene expressed in prespore and spore cells. This gene plays an essential role in sporulation as its disruption leads to abnormal spore morphology and loss of viability. The mutant spores were round and cellulose deposition seemed to be partially affected. Initial prestalk and prespore cell differentiation did not seem to be compromised in the mutant since the expression of several cell-type-specific markers were found to be unaffected. However, the mRNA level of the spore marker spiA was greatly reduced. Activation of the cAMP-dependent protein kinase (PKA) by 8-Br-cAMP was not able to fully bypass the morphological defects of srfA- mutant spores, although this treatment induced spiA mRNA expression. Our results suggest that DdSRF is required for full maturation of spores and participates in the regulation of the expression of the spore-coat marker spiA and probably other maturation genes necessary for proper spore cell differentiation. PMID:9729488

  1. Differentiation of the lateral compartment of the cochlea requires a temporally restricted FGF20 signal.

    Sung-Ho Huh

    2012-01-01

    Full Text Available A large proportion of age-related hearing loss is caused by loss or damage to outer hair cells in the organ of Corti. The organ of Corti is the mechanosensory transducing apparatus in the inner ear and is composed of inner hair cells, outer hair cells, and highly specialized supporting cells. The mechanisms that regulate differentiation of inner and outer hair cells are not known. Here we report that fibroblast growth factor 20 (FGF20 is required for differentiation of cells in the lateral cochlear compartment (outer hair and supporting cells within the organ of Corti during a specific developmental time. In the absence of FGF20, mice are deaf and lateral compartment cells remain undifferentiated, postmitotic, and unresponsive to Notch-dependent lateral inhibition. These studies identify developmentally distinct medial (inner hair and supporting cells and lateral compartments in the developing organ of Corti. The viability and hearing loss in Fgf20 knockout mice suggest that FGF20 may also be a deafness-associated gene in humans.

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

    Rajan eSingh

    2014-10-01

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

  3. Justification of response time testing requirements for pressure and differential pressure sensors

    This paper reports on response time testing (RTT) requirements that were imposed on pressure, differential pressure sensors as a conservative approach to insure that assumptions in the plant safety analyses were met. The purpose of this project has been to identify the need for response time testing using the bases identified in IEEE Standard 338. A combination of plant data analyses, failure modes, and effects analyses (FMEAs) was performed. Eighteen currently qualified sensor models were utilized. The results of these analyses indicate that there are only two failure modes that affect response time, not sensor output concurrently. For these failure modes, appropriate plant actions and testing techniques were identified. Safety system RTT requirements were established by IEEE Standard 338-1975. Criteria for the Periodic Testing of Class IE Power, Protection Systems, presuming the need existed for this testing. This standard established guidelines for periodic testing to verify that loop response times of installed nuclear safety-related equipment were within the limits presumed by the design basis plant transient, accident analyses. The requirements covered all passive, active components in an instrument loop, including sensors. Individual components could be tested either in groups or separately to determine the overall loop response time

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

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

    2015-07-01

    A dichloromethane (DCM) extract of carrot roots was found to stimulate insulin-dependent glucose uptake (GU) in adipocytes in a dose dependent manner. Bioassay-guided fractionation of the DCM extract resulted in the isolation of the polyacetylenes falcarinol and falcarindiol. Both polyacetylenes were able to significantly stimulate basal and/or insulin-dependent GU in 3T3-L1 adipocytes and porcine myotube cell cultures in a dose-dependent manner. Falcarindiol increased peroxisome proliferator-activated receptor (PPAR)γ-mediated transactivation significantly at concentrations of 3, 10 and 30 μM, while PPARγ-mediated transactivation by falcarinol was only observed at 10 μM. Docking studies accordingly indicated that falcarindiol binds to the ligand binding domain of PPARγ with higher affinity than falcarinol and that both polyacetylenes exhibit characteristics of PPARγ partial agonists. Falcarinol was shown to inhibit adipocyte differentiation as evident by gene expression studies and Oil Red O staining, whereas falcarindiol did not inhibit adipocyte differentiation, which indicates that these polyacetylenes have distinct modes of action. The results of the present study suggest that falcarinol and falcarindiol may represent scaffolds for novel partial PPARγ agonists with possible antidiabetic properties. PMID:25970571

  5. Targeting IκB kinase β in Adipocyte Lineage Cells for Treatment of Obesity and Metabolic Dysfunctions.

    Helsley, Robert N; Sui, Yipeng; Park, Se-Hyung; Liu, Zun; Lee, Richard G; Zhu, Beibei; Kern, Philip A; Zhou, Changcheng

    2016-07-01

    IκB kinase β (IKKβ), a central coordinator of inflammation through activation of nuclear factor-κB, has been identified as a potential therapeutic target for the treatment of obesity-associated metabolic dysfunctions. In this study, we evaluated an antisense oligonucleotide (ASO) inhibitor of IKKβ and found that IKKβ ASO ameliorated diet-induced metabolic dysfunctions in mice. Interestingly, IKKβ ASO also inhibited adipocyte differentiation and reduced adiposity in high-fat (HF)-fed mice, indicating an important role of IKKβ signaling in the regulation of adipocyte differentiation. Indeed, CRISPR/Cas9-mediated genomic deletion of IKKβ in 3T3-L1 preadipocytes blocked these cells differentiating into adipocytes. To further elucidate the role of adipose progenitor IKKβ signaling in diet-induced obesity, we generated mice that selectively lack IKKβ in the white adipose lineage and confirmed the essential role of IKKβ in mediating adipocyte differentiation in vivo. Deficiency of IKKβ decreased HF-elicited adipogenesis in addition to reducing inflammation and protected mice from diet-induced obesity and insulin resistance. Further, pharmacological inhibition of IKKβ also blocked human adipose stem cell differentiation. Our findings establish IKKβ as a pivotal regulator of adipogenesis and suggest that overnutrition-mediated IKKβ activation serves as an initial signal that triggers adipose progenitor cell differentiation in response to HF feeding. Inhibition of IKKβ with antisense therapy may represent as a novel therapeutic approach to combat obesity and metabolic dysfunctions. Stem Cells 2016;34:1883-1895. PMID:26991836

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

    Garvey W Timothy

    2006-07-01

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

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

    Sandeep Dave

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

  8. Control of lipid storage and cell size between adipocytes by vesicle-associated glycosylphosphatidylinositol-anchored proteins.

    Müller, Günter

    2011-02-01

    Adipose tissue mass in mammals is expanding by increasing the average cell volume as well as the total number of the adipocytes. Up-regulation of lipid storage in fully differentiated adipocytes resulting in their enlargement is well documented and thought to be a critical mechanism for the expansion of adipose tissue depots during the growth of both lean and obese animals and human beings. A novel molecular mechanism for the regulation of lipid storage and cell size in rat adipocytes has recently been elucidated for the physiological stimuli, palmitate and hydrogen peroxide, the anti-diabetic sulfonylurea drug, glimepiride, and insulin-mimetic phosphoinositolglycans. It encompasses (i) the release of small vesicles, so-called adiposomes, harbouring the glycosylphosphatidylinositol-anchored (c)AMP-degrading phosphodiesterase Gce1 and 5'-nuceotidase CD73 from large donor adipocytes, (ii) the transfer of the adiposomes and their interaction with detergent-insoluble glycolipid-enriched microdomains of the plasma membrane of small acceptor adipocytes, (iii) the translocation of Gce1 and CD73 from the adiposomes to the intracellular lipid droplets of the acceptor adipocytes and (iv) the degradation of (c)AMP at the lipid droplet surface zone by Gce1 and CD73 in the acceptor adipocytes. In concert, this sequence of events leads to up-regulation of esterification of fatty acids into triacylglycerol and down-regulation of their release from triacylglycerol. This apparent mechanism for shifting the triacylglycerol burden from large to small adipocytes may provide novel strategies for the therapy of metabolic diseases, such as type 2 diabetes and obesity. PMID:20883086

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

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

    2013-01-14

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

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

    Akiko Eguchi

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

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

    Günter Müller

    2011-01-01

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

  12. Adipocyte Turnover: Relevance to Human Adipose Tissue Morphology

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

    2009-01-01

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

  13. SIRT1敲除对C57BL/6J小鼠脂肪细胞分化的影响和机制探讨%SIRT1 knockout impairs the differentiation of adipocyte in C57BL/6J mice and its underlying mechanism

    徐芬; 严晋华; 梁华; 许雯; 叶建平; 翁建平

    2013-01-01

    Objective To explore the role and mechanism of SIRT1 (Sirtuin1) in the differentiation of adipocyte.Methods SIRT1 / mice with C57BL/6J gene background were generated and litter-mate wild-type (WT) mice were used as controls.Body weight and fat content were detected and their epididymal fat pads were collected at 28 weeks old of age.The tip part of epididymal fat tissue was incubated in phosphate buffered saline (PBS) containing both BODIPY 558/568 (5 μmol/L in PBS) for adipocytes and isolectin Alexa Fluor 488 (40 μg/ml in PBS) for endothelial cells overnight.The stained cells were then visualized under confocal microscope.Reconstruction of 3 D data sets was accomplished with image processing software Imaris.Immunohistochemistry was used to detect the protein level of endothelial cell marker CD31.Hematoxylin and eosin staining was performed for fixed epididymal fat tissue.Mouse embryonic fibroblast (MEF) cells were prepared from 13-14 days embryos of SIRT1-/-or WT mice and differentiated into adipocytes.Then oil-red O staining was performed.Results Compared with wild-type controls,both body weight (WT 42.1 g ± 1.6 g vs SIRT1 /-25.4 g ± 1.0 g,P < 0.05) and epididymal fat mass (WT 13.4g±1.0 g vs SIRT1-/-7.8 g±0.5 g,P<0.05)were much smaller in the SIRT1 / mice.HE staining of fat tissue exhibited a significant reduction in adipocyte size and extracellular matrix in SIRT1-/-mice.However,the adipogenesis ability of MEF cells was significantly enhanced in vitro in SIRT1-/-MEF cells.Further study found that the density of vascular network decreased by 50% in the tip portion of epididymal fat pads of SIRT1-/ mice (capillary density:WT 2.92% ± 0.03% vs SIRT1 / 1.34% ± 0.02%,P < 0.05).CD31,a cellular marker of decreased angiogenesis,decreased significantly in epididymal fat pads of SIRTI-/-mice.Conclusion SIRT1 knockout impairs adipocyte differentiation in SIRT1 /-mice with C57BL/6J gene background through reduced angiogenesis but not adipogenesis

  14. The effects of eight-week treadmill exercise on adipocyte differentiation and insulin sensitivity in high-fatdiet rat%8周跑台运动对高脂膳食大鼠脂肪细胞分化和胰岛素敏感性的影响

    陈玉娟; 刘尊; 张海峰; 何玉秀; 李立

    2012-01-01

    目的:探讨大鼠经高脂膳食复制胰岛素抵抗模型后,运动对其的改善作用及脂肪细胞分化在其中的影响.方法:SD纯系雄性大鼠40只,随机分为对照组(C)、高脂组(H)、高脂运动组(HE)和普通膳食运动组(E),各运动组进行8周跑台训练,对比各组的胰岛素敏感性指标和脂肪细胞分化各指标.结果:8周高脂膳食成功复制大鼠胰岛素抵抗模型.大鼠脂肪细胞分化各指标变化:PPARγ在E组高于C组(P<0.01),H组高于C组;C/EBPα在H组高于其他各组(P<0.01),E组高于C组,HE组低于H组;E组脂肪细胞分化程度最高(P<0.01);C组增殖指数最高,与H组和E组相比具有显著性差异(P< 0.0I;P< 0.05),HE组高于H组和E组(P<0.05);E组脂肪细胞体积小于C组(P<0.01),细胞数量高于C组;H组细胞体积小于C组(P<0.01),数量也增加(P<0.01),HE组与H组相比脂肪细胞体积较大(P<0.01),且数量减少.脂肪细胞分化指标与胰岛素抵抗指标间具有一定的相关关系.结论:8周跑台运动可以改善由高脂膳食喂养引起的大鼠胰岛素抵抗现象,具体机制可能与其脂肪细胞分化的变化相关.%Objective: To study the effects of aerobic exercise on insulin insistence in the rats feed by high-fiat-diet and discuss whether the effect acted via the adipocyte differentiation. Method:Forty male SD rats were randomly assigned to four groups: control(C), high-fat diet control(H), high-fat diet control+exercise training(HE) and exercise training(E) group. Rats in HE and E groups were given treadmill exercise training. Insulin sensitivity and adipocyte parameters were evaluated. Result :The insulin resistence rat model was duplicated successfully by high-fat-diet. The changes of adipose differentiation were as follows: PPAR y protein of E group was higher than that of C group(P<0.01); that of H group was higher than C group, that of HE group was lower than H group. C/EBP α protein of H group was

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

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

    2016-08-01

    Human subcutaneous fat tissue consists of two layers, superficial adipose tissue (SAT) and deep adipose tissue (DAT). Some recent reports suggest that a disproportionate accumulation of DAT is related to obesity-associated metabolic complications. However, the differences in adipocyte function between SAT and DAT are unclear. To clarify the differences in human adipocyte characteristics between SAT and DAT, human ceiling culture-derived proliferative adipocytes (ccdPAs) were primary cultured from SAT and DAT of three lean female patients. Differences in adipogenic differentiation potential and sensitivity to exogenous adipogenic factors were examined. Epigenetic modification of the CpG island DNA methylation levels of genes related to adipogenesis was measured. In histological analyses, the mean adipocyte size in SAT was significantly larger than that in DAT (8,741 ± 416 vs. 7,732 ± 213 μm(2), P SAT showed significantly greater adipogenesis than did those of DAT. Sensitivity to partial adipogenic stimulation was significantly different between ccdPAs of SAT and DAT. Peroxisome proliferator-activated receptor-γ (PPAR-γ) protein expression and leptin protein secretion from ccdPAs were significantly higher in SAT than DAT. DNA methylation levels of PPAR-γ were significantly lower in ccdPAs of SAT than DAT. Adipocyte size was larger in SAT than DAT in vivo. This is consistent with the findings of an in vitro study that, compared with ccdPAs in DAT, ccdPAs in SAT have higher adipogenic potential and lower DNA methylation levels of PPAR-γ. PMID:27251439

  16. Asymmetric division and differential gene expression during a bacterial developmental program requires DivIVA.

    Prahathees Eswaramoorthy

    2014-08-01

    Full Text Available Sporulation in the bacterium Bacillus subtilis is a developmental program in which a progenitor cell differentiates into two different cell types, the smaller of which eventually becomes a dormant cell called a spore. The process begins with an asymmetric cell division event, followed by the activation of a transcription factor, σF, specifically in the smaller cell. Here, we show that the structural protein DivIVA localizes to the polar septum during sporulation and is required for asymmetric division and the compartment-specific activation of σF. Both events are known to require a protein called SpoIIE, which also localizes to the polar septum. We show that DivIVA copurifies with SpoIIE and that DivIVA may anchor SpoIIE briefly to the assembling polar septum before SpoIIE is subsequently released into the forespore membrane and recaptured at the polar septum. Finally, using super-resolution microscopy, we demonstrate that DivIVA and SpoIIE ultimately display a biased localization on the side of the polar septum that faces the smaller compartment in which σF is activated.

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

    Kees Meijer

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

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

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

    2009-01-01

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

  19. Roles of activin receptor-like kinase 7 signaling and its target, peroxisome proliferator-activated receptor γ, in lean and obese adipocytes

    Yogosawa, Satomi; Izumi, Tetsuro

    2013-01-01

    We recently discovered a novel signaling pathway involving activin receptor-like kinase 7 (ALK7), one of the type I transforming growth factor-β receptors. ALK7 and activated Smads 2, 3, and 4 inhibit the master regulators of adipogenesis, CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ) specifically in differentiated adipocytes, but surprisingly increase both the adipocyte size and lipid content by suppressing lipolysis. Here, we show that, a...

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

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

    2013-01-01

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

  1. A modified protocol to maximize differentiation of human preadipocytes and improve metabolic phenotypes

    Lee, Mi-Jeong; Wu, Yuanyuan; Fried, Susan K.

    2012-01-01

    Adipose stromal cells proliferate and differentiate into adipocytes, providing a valuable model system for studies of adipocyte biology. We compared differentiation protocols for human preadipocytes and report on their metabolic phenotypes. By simply prolonging the adipogenic induction period from the first 3 days to 7 days, the proportion of cells (passage 5–6) acquiring adipocyte morphology increased from 30–70% to over 80% in human subcutaneous preadipocytes. These morphological changes we...

  2. Differential gene expression profiling of human bone marrow-derived mesenchymal stem cells during adipogenic development.

    Menssen Adriane; Häupl Thomas; Sittinger Michael; Delorme Bruno; Charbord Pierre; Ringe Jochen

    2011-01-01

    Abstract Background Adipogenesis is the developmental process by which mesenchymal stem cells (MSC) differentiate into pre-adipocytes and adipocytes. The aim of the study was to analyze the developmental strategies of human bone marrow MSC developing into adipocytes over a defined time scale. Here we were particularly interested in differentially expressed transcription factors and biochemical pathways. We studied genome-wide gene expression profiling of human MSC based on an adipogenic diffe...

  3. Influence of lipolysis on the mobilization of 2,4,5,2'4',5'-hexachlorobiphenyl from adipocytes in vitro

    Epididymal adipocytes, isolated from rats pretreated with [14C]-2,4,5,2',4',5'-hexachlorobiphenyl (6-CB), were utilized to examine the relationship between the mobilization of lipid and 6-CB and to determine whether 6-CB was differentially associated with subcellular organelles over time as has been demonstrated for newly synthesized lipid. Lipolysis, depleted approximately 1% of total cellular triacylglycerols (TG) regardless of time from treatment with 6-CB. The percentage of cellular 6-CB released from adipocytes to incubation buffer infranatants was not correlated with the magnitude of lipolysis produced over the 50-min incubation period; nor was the percentage of 6-CB released to the buffers correlated with the length of the incubation period, regardless of the presence of ISO. Although adipocytes responded similarly to lipolytic stimuli independent of time (days) since 6-CB treatment, significant decreases were found in the percentage of 6-CB released from adipocytes over time. The in vitro labeling of this newly synthesized TG in fat cells with [U-14C]glucose or [1-14C]palmitate demonstrated that TG was differentially distributed among adipocyte organelles. Newly synthesized TG was also the first to be mobilized under lipolytic stimulus. 6-CB was not released in a similar fashion, since radioactivity associated with the chemical levels of [14C]-6-CB and glucose-derived 14C in buffers were not correlated over time

  4. ERK1/ERK2 MAPK signaling is required to increase myelin thickness independent of oligodendrocyte differentiation and initiation of myelination

    Ishii, A.; Fyffe-Maricich, S.L.; Furusho, M.; Miller, R. H.; Bansal, R.

    2012-01-01

    Wrapping of the myelin sheath around axons by oligodendrocytes is critical for the rapid conduction of electrical signals, required for the normal functioning of the central nervous system (CNS). Myelination is a multistep process where oligodendrocytes progress through a well-coordinated differentiation program regulated by multiple extracellular growth and differentiation signals. The intracellular-transduction of the extracellular signals that regulate myelination is poorly understood. Her...

  5. Fibronectin Binding Is Required for Acquisition of Mesenchymal/Endothelial Differentiation Potential in Human Circulating Monocytes

    Noriyuki Seta

    2012-01-01

    Full Text Available We previously reported monocyte-derived multipotential cells (MOMCs, which include progenitors capable of differentiating into a variety of mesenchymal cells and endothelial cells. In vitro generation of MOMCs from circulating CD14+ monocytes requires their binding to extracellular matrix (ECM protein and exposure to soluble factor(s derived from circulating CD14- cells. Here, we investigated the molecular factors involved in MOMC generation by examining the binding of monocytes to ECM proteins. We found that MOMCs were obtained on the fibronectin, but not on type I collagen, laminin, or poly-L-lysine. MOMC generation was followed by changes in the expression profiles of transcription factors and was completely inhibited by either anti-α5 integrin antibody or a synthetic peptide that competed with the RGD domain for the β1-integrin binding site. These results indicate that acquisition of the multidifferentiation potential by circulating monocytes depends on their binding to the RGD domain of fibronectin via cell-surface α5β1 integrin.

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

    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.

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

    Colette N Miller

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

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

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

    2011-01-01

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

  9. Differentiation of placental trophoblast giant cells requires downregulation of p53 and Rb.

    Soloveva, V; Linzer, D I H

    2004-01-01

    Trophoblast giant cells in the rodent placenta form the outermost layer of the extraembryonic compartment, establish direct contact with maternal cells, and produce a number of pregnancy-specific cytokine hormones. Giant cells differentiate from proliferative trophoblasts as they exit the cell cycle and enter a genome-amplifying endocycle, a process we show involves decreased expression of the G1 checkpoint proteins p53 and Rb. Although p53 mRNA levels are unchanged in proliferative compared to differentiated trophoblasts, p53 protein levels are markedly reduced in giant cells. Forced expression of wild type p53 in trophoblasts inhibits differentiation, and expression of a dominant negative p53 peptide stimulates differentiation. Consistent with the loss of p53 protein, differentiated trophoblasts become resistant to apoptosis-inducing agents. Decreased expression of Rb is also detected during differentiation, and overexpression of Rb in trophoblasts inhibits giant cell differentiation. Although an increase in E2F activity would be expected with the loss of Rb, what is observed is an overall decrease in E2F DNA-binding complexes, a shift to new complexes, and a decrease in E2F-dependent gene expression in differentiating trophoblasts. Overall, these results indicate that the combination of a decrease in p53 and Rb represents a functionally important part of the transition of trophoblasts from a proliferative cell cycle to an endocycle in the giant cell differentiation programme. PMID:15013636

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

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

    2004-01-01

    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 triglycer...

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

    Nabilatul Hani Mohd-Radzman; Wan Iryani Wan Ismail; Siti Safura Jaapar; Zainah Adam; Aishah Adam

    2013-01-01

    Stevioside from Stevia rebaudiana has been reported to exert antihyperglycemic effects in both rat and human subjects. There have been few studies on these effects in vitro. In this paper, radioactive glucose uptake assay was implemented in order to assess improvements in insulin sensitivity in 3T3-L1 cells by elevation of glucose uptake following treatment with stevioside. Oil Red-O staining and MTT assay were utilized to confirm adipocyte differentiation and cell viability, respectively. Fi...

  12. Derivation of Adipocytes from Human Endometrial Stem Cells (EnSCs)

    Ai, Jafar; Shahverdi, Ahmad Reza; Barough, Somayeh Ebrahimi; Kouchesfehani, Homa Mohseni; Heidari, Saeed; Roozafzoon, Reza; Verdi, Javad; KHOSHZABAN, Ahad

    2012-01-01

    Background Due to increasing clinical demand for adipose tissue, a suitable cell for reconstructive adipose tissue constructs is needed. In this study, we investigated the ability of Human Endometrial-derived stem cells (EnSCs) as a new source of mesenchymal stem cells to differentiate into adipocytes. EnSCs are the abundant and easy available source with no immunological response, for cell replacement therapy. Methods Single-cell suspensions of EnSCs were obtained from endometrial tissues fr...

  13. Phosphatidylcholine induces apoptosis of 3T3-L1 adipocytes

    Li Hailan

    2011-12-01

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

  14. Required therapeutic dose of 131I for thyroid ablation after surgery for differentiated thyroid carcinoma

    with thyroid remnants after surgery for differentiated thyroid carcinoma one dose of therapeutic 131I of 80-100 mCi is enough for ablation of the thyroid remnants. The requirement of a second dose of therapeutic 131I is evaluated by a thorough assessment of the thyroglobulin values. (authors)

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

    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

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

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

    2014-10-03

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

  17. Insulin/glucose induces natriuretic peptide clearance receptor in human adipocytes: a metabolic link with the cardiac natriuretic pathway.

    Bordicchia, M; Ceresiani, M; Pavani, M; Minardi, D; Polito, M; Wabitsch, M; Cannone, V; Burnett, J C; Dessì-Fulgheri, P; Sarzani, R

    2016-07-01

    Cardiac natriuretic peptides (NP) are involved in cardiorenal regulation and in lipolysis. The NP activity is largely dependent on the ratio between the signaling receptor NPRA and the clearance receptor NPRC. Lipolysis increases when NPRC is reduced by starving or very-low-calorie diet. On the contrary, insulin is an antilipolytic hormone that increases sodium retention, suggesting a possible functional link with NP. We examined the insulin-mediated regulation of NP receptors in differentiated human adipocytes and tested the association of NP receptor expression in visceral adipose tissue (VAT) with metabolic profiles of patients undergoing renal surgery. Differentiated human adipocytes from VAT and Simpson-Golabi-Behmel Syndrome (SGBS) adipocyte cell line were treated with insulin in the presence of high-glucose or low-glucose media to study NP receptors and insulin/glucose-regulated pathways. Fasting blood samples and VAT samples were taken from patients on the day of renal surgery. We observed a potent insulin-mediated and glucose-dependent upregulation of NPRC, through the phosphatidylinositol 3-kinase pathway, associated with lower lipolysis in differentiated adipocytes. No effect was observed on NPRA. Low-glucose medium, used to simulate in vivo starving conditions, hampered the insulin effect on NPRC through modulation of insulin/glucose-regulated pathways, allowing atrial natriuretic peptide to induce lipolysis and thermogenic genes. An expression ratio in favor of NPRC in adipose tissue was associated with higher fasting insulinemia, HOMA-IR, and atherogenic lipid levels. Insulin/glucose-dependent NPRC induction in adipocytes might be a key factor linking hyperinsulinemia, metabolic syndrome, and higher blood pressure by reducing NP effects on adipocytes. PMID:27101299

  18. Cell-cell interactions promote mammary epithelial cell differentiation

    1985-01-01

    Mammary epithelium differentiates in a stromal milieu of adipocytes and fibroblasts. To investigate cell-cell interactions that may influence mammary epithelial cell differentiation, we developed a co-culture system of murine mammary epithelium and adipocytes and other fibroblasts. Insofar as caseins are specific molecular markers of mammary epithelial differentiation, rat anti-mouse casein monoclonal antibodies were raised against the three major mouse casein components to study this interac...

  19. Ginkgolide C Suppresses Adipogenesis in 3T3-L1 Adipocytes via the AMPK Signaling Pathway

    Chian-Jiun Liou

    2015-01-01

    Full Text Available Ginkgolide C, isolated from Ginkgo biloba leaves, is a flavone reported to have multiple biological functions, from decreased platelet aggregation to ameliorating Alzheimer disease. The study aim was to evaluate the antiadipogenic effect of ginkgolide C in 3T3-L1 adipocytes. Ginkgolide C was used to treat differentiated 3T3-L1 cells. Cell supernatant was collected to assay glycerol release, and cells were lysed to measure protein and gene expression related to adipogenesis and lipolysis by western blot and real-time PCR, respectively. Ginkgolide C significantly suppressed lipid accumulation in differentiated adipocytes. It also decreased adipogenesis-related transcription factor expression, including peroxisome proliferator-activated receptor and CCAAT/enhancer-binding protein. Furthermore, ginkgolide C enhanced adipose triglyceride lipase and hormone-sensitive lipase production for lipolysis and increased phosphorylation of AMP-activated protein kinase (AMPK, resulting in decreased activity of acetyl-CoA carboxylase for fatty acid synthesis. In coculture with an AMPK inhibitor (compound C, ginkgolide C also improved activation of sirtuin 1 and phosphorylation of AMPK in differentiated 3T3-L1 cells. The results suggest that ginkgolide C is an effective flavone for increasing lipolysis and inhibiting adipogenesis in adipocytes through the activated AMPK pathway.

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

    Nicholas A Fairbridge

    Full Text Available CD24 is a glycophosphatidylinositol (GPI-linked cell surface receptor that is involved in regulating the survival or differentiation of several different cell types. CD24 has been used to identify pre-adipocytes that are able to reconstitute white adipose tissue (WAT in vivo. Moreover, we recently found that the dynamic upregulation of CD24 in vitro during early phases of adipogenesis is necessary for mature adipocyte development. To determine the role of CD24 in adipocyte development in vivo, we evaluated the development of the inguinal and interscapular subcutaneous WAT and the epididymal visceral WAT in mice with a homozygous deletion of CD24 (CD24KO. We observed a significant decrease in WAT mass of 40% to 74% in WAT mass from both visceral and subcutaneous depots in male mice, with no significant effect in female mice, compared to wild-type (WT sex- and age-matched controls. We also found that CD24KO mice had increased fasting glucose and free fatty acids, decreased fasting insulin, and plasma leptin. No major differences were observed in the sensitivity to insulin or glucose, or in circulating triglycerides, total cholesterol, HDL-cholesterol, or LDL-cholesterol levels between WT and CD24KO mice. Challenging the CD24KO mice with either high sucrose (35% or high fat (45% diets that promote increased adiposity, increased WAT mass and fasting insulin, adiponectin and leptin levels, as well as reduced the sensitivity to insulin and glucose, to the levels of WT mice on the same diets. The CD24-mediated reduction in fat pad size was due to a reduction in adipocyte cell size in all depots with no significant reduction pre-adipocyte or adipocyte cell number. Thus, we have clearly demonstrated that the global absence of CD24 affects adipocyte cell size in vivo in a sex- and diet-dependent manner, as well as causing metabolic disturbances in glucose homeostasis and free fatty acid levels.

  1. Integration of Mature Adipocytes to Build-Up a Functional Three-Layered Full-Skin Equivalent

    Huber, Birgit; Link, Antonia; Linke, Kirstin; Gehrke, Sandra A.; Winnefeld, Marc

    2016-01-01

    Large, deep full-thickness skin wounds from high-graded burns or trauma are not able to reepithelialize sufficiently, resulting in scar formation, mobility limitations, and cosmetic deformities. In this study, in vitro-constructed tissue replacements are needed. Furthermore, such full-skin equivalents would be helpful as in vivo-like test systems for toxicity, cosmetic, and pharmaceutical testing. Up to date, no skin equivalent is available containing the underlying subcutaneous fatty tissue. In this study, we composed a full-skin equivalent and evaluated three different media for the coculture of mature adipocytes, fibroblasts, and keratinocytes. Therefore, adipocyte medium was supplemented with ascorbyl-2-phosphate and calcium chloride, which are important for successful epidermal stratification (Air medium). This medium was further supplemented with two commercially available factor combinations often used for the in vitro culture of keratinocytes (Air-HKGS and Air-KGM medium). We showed that in all media, keratinocytes differentiated successfully to build a stratified epidermal layer and expressed cytokeratin 10 and 14. Perilipin A-positive adipocytes could be found in all tissue models for up to 14 days, whereas adipocytes in the Air-HKGS and Air-KGM medium seemed to be smaller. Adipocytes in all tissue models were able to release adipocyte-specific factors, whereas the supplementation of keratinocyte-specific factors had a slightly negative effect on adipocyte functionality. The permeability of the epidermis of all models was comparable since they were able to withstand a deep penetration of cytotoxic Triton X in the same manner. Taken together, we were able to compose functional three-layered full-skin equivalents by using the Air medium. PMID:27334067

  2. Differentiation of endometrial stromal stem cells into osteoblasts and adipocytes in vitro%子宫内膜基质干细胞的体外成骨诱导和成脂诱导分化

    杨新园; 李旭; 陈葳

    2012-01-01

    目的 探讨子宫内膜基质干细胞的多向分化潜能.方法 取因子宫肌瘤行全子宫切除术患者的子宫内膜组织,磁珠分选子宫内膜基质干细胞,进行传代培养.传代细胞分别加入成骨诱导剂和成脂诱导剂培养,并通过茜素红和油红O染色对成骨细胞和脂肪细胞形态进行鉴定.结果 子宫内膜基质干细胞呈成纤维细胞样贴壁生长,其经成骨、成脂诱导培养3周后形态、体积发生明显改变.茜素红染色显示细胞团中央能形成钙化结节;成脂诱导后油红O染色可见细胞质内出现橙红色脂滴.结论 子宫内膜基质干细胞经体外诱导培养后可向成骨细胞和脂肪细胞分化,并具有明显的成骨和成脂细胞形态,表明子宫内膜基质干细胞具有多向分化潜能.%Objective To investigate the multilineage differentiation capacity of stromal stem cells isolated and cultured from human endometrial tissues. Methods Single-cell suspensions of endometrial stromal stem cells were obtained from hysterectomy tissues of women experiencing normal menstrual cycles. Purified stromal stem cell suspensions were then obtained by selecting cells with a further round of magnetic bead sorting using anti-EpCAM-coated Dynabeads. Rare human endometrial EpCAM-stromal stem cells were screened by inverted microscope each day and identified by flow cytometer. Then the cells were cultured in osteoblast-inducing culture medium, and osteoblast phenotype was assayed with alizarin red staining. The passage cells were cultured in adipogenesis-medium and stained with oil red O for identification. Results Endometrial stromal stem cells grew as adherent cells and presented fibroblast-like in vitro, and could stably proliferate and be passed. The cells changed from fibroblast-like into ellipse after osteoblast-inducing cultivation. After induction for 21 d, alizarin red staining demonstrated the formation of mineralized nods in extracellular matrix. Under the

  3. Extreme cellular adaptations and cell differentiation required by a cyanobacterium for carbonate excavation.

    Guida, Brandon Scott; Garcia-Pichel, Ferran

    2016-05-17

    Some cyanobacteria, known as euendoliths, excavate and grow into calcium carbonates, with their activity leading to significant marine and terrestrial carbonate erosion and to deleterious effects on coral reef and bivalve ecology. Despite their environmental relevance, the mechanisms by which they can bore have remained elusive and paradoxical, in that, as oxygenic phototrophs, cyanobacteria tend to alkalinize their surroundings, which will encourage carbonate precipitation, not dissolution. Therefore, cyanobacteria must rely on unique adaptations to bore. Studies with the filamentous euendolith, Mastigocoleus testarum, indicated that excavation requires both cellular energy and transcellular calcium transport, mediated by P-type ATPases, but the cellular basis for this phenomenon remains obscure. We present evidence that excavation in M. testarum involves two unique cellular adaptations. Long-range calcium transport is based on active pumping at multiple cells along boring filaments, orchestrated by the preferential localization of calcium ATPases at one cell pole, in a ring pattern, facing the cross-walls, and by repeating this placement and polarity, a pattern that breaks at branching and apical cells. In addition, M. testarum differentiates specialized cells we call calcicytes, that which accumulate calcium at concentrations more than 500-fold those found in other cyanobacteria, concomitantly and drastically lowering photosynthetic pigments and enduring severe cytoplasmatic alkalinization. Calcicytes occur commonly, but not exclusively, in apical parts of the filaments distal to the excavation front. We suggest that calcicytes allow for fast calcium flow at low, nontoxic concentrations through undifferentiated cells by providing buffering storage for excess calcium before final excretion to the outside medium. PMID:27140633

  4. Carnitine palmitoyltransferase 1A prevents fatty acid-induced adipocyte dysfunction through suppression of c-Jun N-terminal kinase.

    Gao, Xuefei; Li, Kuai; Hui, Xiaoyan; Kong, Xiangping; Sweeney, Gary; Wang, Yu; Xu, Aimin; Teng, Maikun; Liu, Pentao; Wu, Donghai

    2011-05-01

    The adipocyte is the principal cell type for fat storage. CPT1 (carnitine palmitoyltransferase-1) is the rate-limiting enzyme for fatty acid β-oxidation, but the physiological role of CPT1 in adipocytes remains unclear. In the present study, we focused on the specific role of CPT1A in the normal functioning of adipocytes. Three 3T3-L1 adipocyte cell lines stably expressing hCPT1A (human CPT1A) cDNA, mouse CPT1A shRNA (short-hairpin RNA) or GFP (green fluorescent protein) were generated and the biological functions of these cell lines were characterized. Alteration in CPT1 activity, either by ectopic overexpression or pharmacological inhibition using etomoxir, did not affect adipocyte differentiation. However, overexpression of hCPT1A significantly reduced the content of intracellular NEFAs (non-esterified fatty acids) compared with the control cells when adipocytes were challenged with fatty acids. The changes were accompanied by an increase in fatty acid uptake and a decrease in fatty acid release. Interestingly, CPT1A protected against fatty acid-induced insulin resistance and expression of pro-inflammatory adipokines such as TNF-α (tumour necrosis factor-α) and IL-6 (interleukin-6) in adipocytes. Further studies demonstrated that JNK (c-Jun N terminal kinase) activity was substantially suppressed upon CPT1A overexpression, whereas knockdown or pharmacological inhibition of CPT1 caused a significant enhancement of JNK activity. The specific inhibitor of JNK SP600125 largely abolished the changes caused by the shRNA- and etomoxir-mediated decrease in CPT1 activity. Moreover, C2C12 myocytes co-cultured with adipocytes pre-treated with fatty acids displayed altered insulin sensitivity. Taken together, our findings have identified a favourable role for CPT1A in adipocytes to attenuate fatty acid-evoked insulin resistance and inflammation via suppression of JNK. PMID:21348853

  5. Induction of early Purkinje cell dendritic differentiation by thyroid hormone requires RORα

    Bois-Joyeux Brigitte

    2010-07-01

    Full Text Available Abstract Background The active form (T3 of thyroid hormone (TH controls critical aspects of cerebellar development, such as migration of postmitotic neurons and terminal dendritic differentiation of Purkinje cells. The effects of T3 on early dendritic differentiation are poorly understood. Results In this study, we have analyzed the influence of T3 on the progression of the early steps of Purkinje cell dendritic differentiation in postnatal day 0 organotypic cerebellar cultures. These steps include, successively, regression of immature neuritic processes, a stellate cell stage, and the extension of several long and mature perisomatic protrusions before the growth of the ultimate dendritic tree. We also studied the involvement of RORα, a nuclear receptor controlling early Purkinje cell dendritic differentiation. We show that T3 treatment leads to an accelerated progression of the early steps of dendritic differentiation in culture, together with an increased expression of RORα (mRNA and protein in both Purkinje cells and interneurons. Finally, we show that T3 failed to promote early dendritic differentiation in staggerer RORα-deficient Purkinje cells. Conclusions Our results demonstrate that T3 action on the early Purkinje cell dendritic differentiation process is mediated by RORα.

  6. Fast Prediction of Differential Mode Noise Input Filter Requirements for FLyback and Boost Unity Power Factor Converters

    Andersen, Michael Andreas E.

    1997-01-01

    Two new and simple methods to make predictions of the differential mode (DM) input filter requirements are presented, one for flyback and one for boost unity power factor converters. They have been verified by measurements. They give the designer the ability to predict the DM input noise filter...

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

    Scheja, Ludger; Heeren, Joerg

    2016-05-01

    In mammalian evolution, three types of adipocytes have developed, white, brown and beige adipocytes. White adipocytes are the major constituents of white adipose tissue (WAT), the predominant store for energy-dense triglycerides in the body that are released as fatty acids during catabolic conditions. The less abundant brown adipocytes, the defining parenchymal cells of brown adipose tissue (BAT), internalize triglycerides that are stored intracellularly in multilocular lipid droplets. Beige adipocytes (also known as brite or inducible brown adipocytes) are functionally very similar to brown adipocytes and emerge in specific WAT depots in response to various stimuli including sustained cold exposure. The activation of brown and beige adipocytes (together referred to as thermogenic adipocytes) causes both the hydrolysis of stored triglycerides as well as the uptake of lipids and glucose from the circulation. Together, these fuels are combusted for heat production to maintain body temperature in mammals including adult humans. Given that heating by brown and beige adipocytes is a very-well controlled and energy-demanding process which entails pronounced shifts in energy fluxes, it is not surprising that an intensive interplay exists between the various adipocyte types and parenchymal liver cells, and that this influences systemic metabolic fluxes and endocrine networks. In this review we will emphasize the role of hepatic factors that regulate the metabolic activity of white and thermogenic adipocytes. In addition, we will discuss the relevance of lipids and hormones that are secreted by white, brown and beige adipocytes regulating liver metabolism in order to maintain systemic energy metabolism in health and disease. PMID:26829204

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

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

    2015-01-01

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

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

    Marina R Pulido

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

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

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

  11. Prolonged efficiency of siRNA-mediated gene silencing in primary cultures of human preadipocytes and adipocytes

    Lee, Mi-Jeong; Pickering, R. Taylor; Puri, Vishwajeet

    2013-01-01

    Objective Primary human preadipocytes and differentiated adipocytes in culture are valuable cell culture systems to study adipogenesis and adipose function in relation to human adipose biology. To use these systems for mechanistic studies, we studied siRNA-mediated knockdown of genes for its effectiveness. Design and Methods Methods were developed to effectively deliver siRNA to for gene silencing in primary preadipocytes isolated from human subcutaneous adipose tissue and newly-differentiate...

  12. Optical detection of pores in adipocyte membrane

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

    2013-08-01

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

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

    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

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

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

    2015-08-15

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

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

    Eisinger, Kristina; Rein-Fischboeck, Lisa; Pohl, Rebekka; Meier, Elisabeth M; Krautbauer, Sabrina; Buechler, Christa

    2016-07-01

    The scaffold protein alpha-syntrophin (SNTA) regulates lipolysis indicating a role in lipid homeostasis. Adipocytes are the main lipid storage cells in the body, and here, the function of SNTA has been analyzed in 3T3-L1 cells. SNTA is expressed in preadipocytes and is induced early during adipogenesis. Knock-down of SNTA in preadipocytes increases their proliferation. Proteins which are induced during adipogenesis like adiponectin and caveolin-1, and the inflammatory cytokine IL-6 are at normal levels in the mature cells differentiated from preadipocytes with low SNTA. This suggests that SNTA does neither affect differentiation nor inflammation. Expression of proteins with a role in cholesterol and triglyceride homeostasis is unchanged. Consequently, basal and epinephrine induced lipolysis as well as insulin stimulated phosphorylation of Akt and ERK1/2 are normal. Importantly, adipocytes with low SNTA form smaller lipid droplets and store less triglycerides. Stearoyl-CoA reductase and MnSOD are reduced upon SNTA knock-down but do not contribute to lower lipid levels. Oleate uptake is even increased in cells with SNTA knock-down. In summary, current data show that SNTA is involved in the expansion of lipid droplets independent of adipogenesis. Enhanced preadipocyte proliferation and capacity to store surplus fatty acids may protect adipocytes with low SNTA from lipotoxicity in obesity. PMID:27242274

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

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

    2013-01-01

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

  17. Adipocytes as regulators of energy balance and glucose homeostasis

    Rosen, Evan D.; Spiegelman, Bruce M.

    2006-01-01

    Adipocytes have been studied with increasing intensity as a result of the emergence of obesity as a serious public health problem and the realization that adipose tissue serves as an integrator of various physiological pathways. In particular, their role in calorie storage makes adipocytes well suited to the regulation of energy balance. Adipose tissue also serves as a crucial integrator of glucose homeostasis. Knowledge of adipocyte biology is therefore crucial for understanding the pathophy...

  18. Analysis and Isolation of Adipocytes by Flow Cytometry

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

    2014-01-01

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

  19. Cadmium modulates adipocyte functions in metallothionein-null mice

    Our previous study has demonstrated that exposure to cadmium (Cd), a toxic heavy metal, causes a reduction of adipocyte size and the modulation of adipokine expression. To further investigate the significance of the Cd action, we studied the effect of Cd on the white adipose tissue (WAT) of metallothionein null (MT−/−) mice, which cannot form atoxic Cd–MT complexes and are used for evaluating Cd as free ions, and wild type (MT+/+) mice. Cd administration more significantly reduced the adipocyte size of MT−/− mice than that of MT+/+ mice. Cd exposure also induced macrophage recruitment to WAT with an increase in the expression level of Ccl2 (MCP-1) in the MT−/− mice. The in vitro exposure of Cd to adipocytes induce triglyceride release into culture medium, decrease in the expression levels of genes involved in fatty acid synthesis and lipid hydrolysis at 24 h, and at 48 h increase in phosphorylation of the lipid-droplet-associated protein perilipin, which facilitates the degradation of stored lipids in adipocytes. Therefore, the reduction in adipocyte size by Cd may arise from an imbalance between lipid synthesis and lipolysis. In addition, the expression levels of leptin, adiponectin and resistin decreased in adipocytes. Taken together, exposure to Cd may induce unusually small adipocytes and modulate the expression of adipokines differently from the case of physiologically small adipocytes, and may accelerate the risk of developing insulin resistance and type 2 diabetes. - Highlights: • Cd causes a marked reduction in adipocyte size in MT-null mice. • Cd enhances macrophage migration into adipose tissue and disrupt adipokine secretion. • MT gene alleviates Cd-induced adipocyte dysfunctions. • Cd enhances the degradation of stored lipids in adipocytes, mediated by perilipin. • Cd induces unusually small adipocytes and the abnormal expression of adipokines

  20. Cadmium modulates adipocyte functions in metallothionein-null mice

    Kawakami, Takashige; Nishiyama, Kaori; Kadota, Yoshito; Sato, Masao; Inoue, Masahisa; Suzuki, Shinya, E-mail: suzukis@ph.bunri-u.ac.jp

    2013-11-01

    Our previous study has demonstrated that exposure to cadmium (Cd), a toxic heavy metal, causes a reduction of adipocyte size and the modulation of adipokine expression. To further investigate the significance of the Cd action, we studied the effect of Cd on the white adipose tissue (WAT) of metallothionein null (MT{sup −/−}) mice, which cannot form atoxic Cd–MT complexes and are used for evaluating Cd as free ions, and wild type (MT{sup +/+}) mice. Cd administration more significantly reduced the adipocyte size of MT{sup −/−} mice than that of MT{sup +/+} mice. Cd exposure also induced macrophage recruitment to WAT with an increase in the expression level of Ccl2 (MCP-1) in the MT{sup −/−} mice. The in vitro exposure of Cd to adipocytes induce triglyceride release into culture medium, decrease in the expression levels of genes involved in fatty acid synthesis and lipid hydrolysis at 24 h, and at 48 h increase in phosphorylation of the lipid-droplet-associated protein perilipin, which facilitates the degradation of stored lipids in adipocytes. Therefore, the reduction in adipocyte size by Cd may arise from an imbalance between lipid synthesis and lipolysis. In addition, the expression levels of leptin, adiponectin and resistin decreased in adipocytes. Taken together, exposure to Cd may induce unusually small adipocytes and modulate the expression of adipokines differently from the case of physiologically small adipocytes, and may accelerate the risk of developing insulin resistance and type 2 diabetes. - Highlights: • Cd causes a marked reduction in adipocyte size in MT-null mice. • Cd enhances macrophage migration into adipose tissue and disrupt adipokine secretion. • MT gene alleviates Cd-induced adipocyte dysfunctions. • Cd enhances the degradation of stored lipids in adipocytes, mediated by perilipin. • Cd induces unusually small adipocytes and the abnormal expression of adipokines.

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

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

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

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

    2011-07-08

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

  3. Anterior pituitary influence on adipokine expression and secretion by porcine adipocytes.

    Saleri, R; Cavalli, V; Martelli, P; Borghetti, P

    2016-06-01

    Nutritional stressors may cause negative effects on animal health and growth and lead to significant economic impact. Adipose tissue is an endocrine organ producing, mediators and hormones, called adipokines. They play a dynamic role in body homeostasis and in the regulation of energy expenditure, interacting with feeding behavior, hormones and growth factors. This in vitro study aimed to investigate how nutritional conditions and growth hormone (GH) can influence nitric oxide (NO) production and the expression and secretion of three important adipokines, that is leptin, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), by swine adipocytes. In our experimental model, mesenchymal stem cells from omental adipose tissue were induced to adipogenic differentiation. After differentiation, adipocytes were incubated for 24 h (T0) with DMEM/Ham's F12 (group A) or DMEM/Ham's F12 salts (group B), a DMEM/Ham's F12 formulation deprived of nutritional components. Primary adipocyte cells were also co-cultured for 4 h (T+4) or 12 h (T+12) with or without anterior pituitary slices. To stimulate GH secretion by pituitary cells, growth hormone releasing hormone at 10-8 M was added at the start of the incubation times (4 or 12 h). At T0, T+4 and T+12, NO production, leptin, IL-6 and TNF-α expression and secretion were measured. NO increased (Pculture conditions. Deprived medium and coincubation with anterior pituitary positively influenced leptin secretion and expression. TNF-α was expressed and secreted only in deprived culture condition groups (B, B1 and B2). Nutrients availability and pituitary co-culture did not affect IL-6 expression and secretion. Our study shows an endocrine function for porcine adipocytes. In our model, adipocytes readily responded to nutritional inputs by secretion of molecules affecting energy balance. This secretion capacity was modulated by GH. Improving our knowledge of the role of adipocyte in the endocrine system, may lead to a more complete

  4. Enhanced accumulation of adipocytes in bone marrow stromal cells in the presence of increased extracellular and intracellular [Ca{sup 2+}

    Hashimoto, Ryota, E-mail: hryota@juntendo.ac.jp [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Katoh, Youichi, E-mail: katoyo@juntendo-urayasu.jp [Institute for Environmental and Gender-Specific Medicine, Department of Cardiology, Juntendo University Faculty of Medicine Urayasu Hospital, Tomioka 2-1-1, Urayasu-shi, Chiba 279-0022 (Japan); Nakamura, Kyoko [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Itoh, Seigo [Department of Cardiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Iesaki, Takafumi [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Daida, Hiroyuki [Department of Cardiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Nakazato, Yuji [Institute for Environmental and Gender-Specific Medicine, Department of Cardiology, Juntendo University Faculty of Medicine Urayasu Hospital, Tomioka 2-1-1, Urayasu-shi, Chiba 279-0022 (Japan); Okada, Takao [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2012-07-13

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

  5. Sexual differentiation of the brain requires perinatal kisspeptin-GnRH neuron signaling.

    Clarkson, Jenny; Busby, Ellen R; Kirilov, Milen; Schütz, Günther; Sherwood, Nancy M; Herbison, Allan E

    2014-11-12

    Sex differences in brain function underlie robust differences between males and females in both normal and disease states. Although alternative mechanisms exist, sexual differentiation of the male mammalian brain is initiated predominantly by testosterone secreted by the testes during the perinatal period. Despite considerable advances in understanding how testosterone and its metabolite estradiol sexually differentiate the brain, little is known about the mechanism that generates the male-specific perinatal testosterone surge. In mice, we show that a male-specific activation of GnRH neurons occurs 0-2 h following birth and that this correlates with the male-specific surge of testosterone occurring up to 5 h after birth. The necessity of GnRH signaling for the sexually differentiating effects of the perinatal testosterone surge was demonstrated by the persistence of female-like brain characteristics in adult male, GnRH receptor knock-out mice. Kisspeptin neurons have recently been identified to be potent, direct activators of GnRH neurons. We demonstrate that a population of kisspeptin neurons appears in the preoptic area of only the male between E19 and P1. The importance of kisspeptin inputs to GnRH neurons for the process of sexual differentiation was demonstrated by the lack of a normal neonatal testosterone surge, and disordered brain sexual differentiation of male mice in which the kisspeptin receptor was deleted selectively from GnRH neurons. These observations demonstrate the necessity of perinatal GnRH signaling for driving brain sexual differentiation and indicate that kisspeptin inputs to GnRH neurons are essential for this process to occur. PMID:25392497

  6. The Snail family member Worniu is continuously required in neuroblasts to prevent Elav-induced premature differentiation

    Lai, Sen-Lin; Miller, Michael R.; Robinson, Kristin J.; Doe, Chris Q.

    2012-01-01

    Snail family transcription factors are best known for regulating epithelial-mesenchymal transition (EMT). The Drosophila Snail family member Worniu is specifically transcribed in neural progenitors (neuroblasts) throughout their lifespan, and worniu mutants show defects in neuroblast delamination (a form of EMT). However, the role of Worniu in neuroblasts beyond their formation is unknown. We performed RNA-seq on worniu mutant larval neuroblasts and observed reduced cell cycle transcripts and increased neural differentiation transcripts. Consistent with these genomic data, worniu mutant neuroblasts showed a striking delay in prophase/metaphase transition by live imaging, and increased levels of the conserved neuronal differentiation splicing factor Elav. Reducing Elav levels significantly suppressed the worniu mutant phenotype. We conclude that Worniu is continuously required in neuroblasts to maintain self-renewal by promoting cell cycle progression and inhibiting premature differentiation. PMID:23079601

  7. Obestatin as a regulator of adipocyte metabolism and adipogenesis

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

    2011-01-01

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

  8. Olig1 function is required for oligodendrocyte differentiation in the mouse brain.

    Dai, Jinxiang; Bercury, Kathryn K; Ahrendsen, Jared T; Macklin, Wendy B

    2015-03-11

    Oligodendrocyte differentiation and myelination are tightly regulated processes orchestrated by a complex transcriptional network. Two bHLH transcription factors in this network, Olig1 and Olig2, are expressed exclusively by oligodendrocytes after late embryonic development. Although the role of Olig2 in the lineage is well established, the role of Olig1 is still unclear. The current studies analyzed the function of Olig1 in oligodendrocyte differentiation and developmental myelination in brain. Both oligodendrocyte progenitor cell commitment and oligodendrocyte differentiation were impaired in the corpus callosum of Olig1-null mice, resulting in hypomyelination throughout adulthood in the brain. As seen in previous studies with this mouse line, although there was an early myelination deficit in the spinal cord, essentially full recovery with normal spinal cord myelination was seen. Intriguingly, this regional difference may be partially attributed to compensatory upregulation of Olig2 protein expression in the spinal cord after Olig1 deletion, which is not seen in brain. The current study demonstrates a unique role for Olig1 in promoting oligodendrocyte progenitor cell commitment, differentiation, and subsequent myelination primarily in brain, but not spinal cord. PMID:25762682

  9. Berberine Suppresses Adipocyte Differentiation via Decreasing CREB Transcriptional Activity

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

    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 pro...

  10. Brown adipocyte differentiation is regulated by hedgehog signaling during development

    During development, brown fat tissue arises from mesenchymal precursor cells under the control of signaling networks that are not yet well understood. The Hedgehog (Hh) signaling pathway is one of the major signaling pathways that regulate mesenchymal cell fate. However, whether the Hh pathway contr...

  11. THE TRANSCRIPTION FACTOR GATA2 REGULATES DIFFERENTIATION OF BROWN ADIPOCYTES

    Brown fat tissue is functionally different than the white fat, since brown fat burns lipid to generate heat for body temperature maintenance. However, brown fat cells share with white fat cells a similar molecular mechanism for fat cell formation. We have demonstrated previously that the GATA family...

  12. Chromium propionate enhances adipogenic differentiation of bovine intramuscular adipocytes

    Rebecca eTokach; Flavio eRibeiro; Ki Yong eChung; Whitney eRounds; Johnson, Bradley J.

    2015-01-01

    In vitro experiments were performed to determine the effects of increasing concentrations of chromium propionate on mRNA and protein abundance of different enzymes and receptors. Intramuscular and subcutaneous preadipocytes and bovine satellite cells were isolated from the longissimus muscle to determine the effect of treatment on glucose transporter type 4 (GLUT4) and peroxisome proliferator-activated receptor γ mRNA and GLUT4 protein abundance. Preadipocyte cultures were treated with diffe...

  13. Chromium Propionate Enhances Adipogenic Differentiation of Bovine Intramuscular Adipocytes

    Tokach, Rebecca J.; Ribeiro, Flavio R. B.; Chung, Ki Yong; Rounds, Whitney; Johnson, Bradley J.

    2015-01-01

    In vitro experiments were performed to determine the effects of increasing concentrations of chromium propionate (CrPro) on mRNA and protein abundance of different enzymes and receptors. Intramuscular (IM) and subcutaneous (SC) preadipocytes and bovine satellite cells were isolated from the longissimus muscle to determine the effect of treatment on glucose transporter type 4 (GLUT4) and peroxisome proliferator-activated receptor γ mRNA and GLUT4 protein abundance. Preadipocyte cultures were t...

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

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

    2005-01-01

    A diet enriched in PUFAs, in particular of the n-3 family, decreases adipose tissue mass and suppresses development of obesity in rodents. Although several nuclear hormone receptors are identified as PUFA targets, the precise molecular mechanisms underlying the effects of PUFAs still remain to be...

  15. Differentiation of human pre-adipocytes by recombinant adiponectin

    Avides, Maria do Carmo; Domingues, Lucília; Vicente, A.A.; J. A. Teixeira

    2008-01-01

    Obesity has become a global health problem and it is linked to a higher risk of diseases and metabolic disorders such as diabetes, cardiovascular disease, and cancer. The adipose tissue plays an important role in monitoring and controlling whole-body metabolism by secreting a variety of bioactive molecules such as adiponectin. Deficiencies of this hormone can cause type II diabetes and cardiovascular disease both in mice and in humans. Therefore, adiponectin is an attractive molecule...

  16. Use of green fluorescent fusion protein to track activation of the transcription factor osterix during early osteoblast differentiation

    Osterix (Osx) is a transcription factor required for the differentiation of preosteoblasts into fully functioning osteoblasts. However, the pattern of Osx activation during preosteoblast differentiation and maturation has not been clearly defined. Our aim was to study Osx activation during these processes in osteoblasts differentiating from murine and human embryonic stem cells (ESC). To do this, we constructed an Osx-GFP fusion protein reporter system to track Osx translocation within the cells. The distribution of Osx-GFP at representative stages of differentiation was also investigated by screening primary osteoblasts, mesenchymal stem cells, synoviocytes, and pre-adipocytes. Our experiments revealed that Osx-GFP protein was detectable in the cytoplasm of cultured, differentiated ESC 4 days after plating of enzymatically dispersed embryoid bodies. Osterix-GFP protein became translocated into the nucleus on day 7 following transfer of differentiated ESC to osteogenic medium. After 14 days of differentiation, cells showing nuclear translocation of Osx-GFP formed rudimentary bone nodules that continued to increase in number over the following weeks (through day 21). We also found that Osx translocated into the nuclei of mesenchymal stem cells (C3H10T1/2) and pre-osteoblasts (MC3T3-E1) and showed partial activation in pre-adipocytes (MC3T3-L1). These data suggest that Osx activation occurs at a very early point in the differentiation of the mesenchymal-osteoblastic lineage

  17. Is Very High Thyroid Stimulating Hormone Level Required in Differentiated Thyroid Cancer for Ablation Success?

    Zekiye Hasbek; Bülent Turgut

    2016-01-01

    Objective: Remnant ablation with radioactive iodine (I-131) is a successful form of treatment that aims to destroy the remaining residual tissue and/or metastatic tissue after total thyroidectomy in differentiated thyroid cancer (DTC) patients. High level of thyroid stimulating hormone (TSH) (≥30 mIU/L) is recommended for success of ablation treatment. In this retrospective study, our aim was to investigate whether the TSH levels at the time of ablation effect the success of radioact...

  18. Reactive Oxygen Species Generated by NADPH Oxidase 2 and 4 Are Required for Chondrogenic Differentiation*

    Kim, Ki Soon; Choi, Hae Woong; Yoon, Hee Eun; Kim, Ick Young

    2010-01-01

    Although generation of reactive oxygen species (ROS) by NADPH oxidases (Nox) is thought to be important for signal transduction in nonphagocytic cells, little is known of the role ROS plays in chondrogenesis. We therefore examined the possible contribution of ROS generation to chondrogenesis using both ATDC5 cells and primary chondrocytes derived from mouse embryos. The intracellular level of ROS was increased during the differentiation process, which was then blocked by treatment with the RO...

  19. Syndecan-1 is required to maintain intradermal fat and prevent cold stress.

    Ildiko Kasza

    2014-08-01

    Full Text Available Homeostatic temperature regulation is fundamental to mammalian physiology and is controlled by acute and chronic responses of local, endocrine and nervous regulators. Here, we report that loss of the heparan sulfate proteoglycan, syndecan-1, causes a profoundly depleted intradermal fat layer, which provides crucial thermogenic insulation for mammals. Mice without syndecan-1 enter torpor upon fasting and show multiple indicators of cold stress, including activation of the stress checkpoint p38α in brown adipose tissue, liver and lung. The metabolic phenotype in mutant mice, including reduced liver glycogen, is rescued by housing at thermoneutrality, suggesting that reduced insulation in cool temperatures underlies the observed phenotypes. We find that syndecan-1, which functions as a facultative lipoprotein uptake receptor, is required for adipocyte differentiation in vitro. Intradermal fat shows highly dynamic differentiation, continuously expanding and involuting in response to hair cycle and ambient temperature. This physiology probably confers a unique role for Sdc1 in this adipocyte sub-type. The PPARγ agonist rosiglitazone rescues Sdc1-/- intradermal adipose tissue, placing PPARγ downstream of Sdc1 in triggering adipocyte differentiation. Our study indicates that disruption of intradermal adipose tissue development results in cold stress and complex metabolic pathology.

  20. TGF-{beta} receptors, in a Smad-independent manner, are required for terminal skeletal muscle differentiation

    Droguett, Rebeca; Cabello-Verrugio, Claudio; Santander, Cristian [Centro de Regulacion Celular y Patologia, Centro de Regeneracion y Envejecimiento (CARE), Departamento de Biologia Celular y Molecular, MIFAB, Pontificia Universidad Catolica de Chile, Santiago (Chile); Brandan, Enrique, E-mail: ebrandan@bio.puc.cl [Centro de Regulacion Celular y Patologia, Centro de Regeneracion y Envejecimiento (CARE), Departamento de Biologia Celular y Molecular, MIFAB, Pontificia Universidad Catolica de Chile, Santiago (Chile)

    2010-09-10

    Skeletal muscle differentiation is strongly inhibited by transforming growth factor type {beta} (TGF-{beta}), although muscle formation as well as regeneration normally occurs in an environment rich in this growth factor. In this study, we evaluated the role of intracellular regulatory Smads proteins as well as TGF-{beta}-receptors (TGF-{beta}-Rs) during skeletal muscle differentiation. We found a decrease of TGF-{beta} signaling during differentiation. This phenomenon is explained by a decline in the levels of the regulatory proteins Smad-2, -3, and -4, a decrease in the phosphorylation of Smad-2 and lost of nuclear translocation of Smad-3 and -4 in response to TGF-{beta}. No change in the levels and inhibitory function of Smad-7 was observed. In contrast, we found that TGF-{beta}-R type I (TGF-{beta}-RI) and type II (TGF-{beta}-RII) increased on the cell surface during skeletal muscle differentiation. To analyze the direct role of the serine/threonine kinase activities of TGF-{beta}-Rs, we used the specific inhibitor SB 431542 and the dominant-negative form of TGF-{beta}-RII lacking the cytoplasmic domain. The TGF-{beta}-Rs were important for successful muscle formation, determined by the induction of myogenin, creatine kinase activity, and myosin. Silencing of Smad-2/3 expression by specific siRNA treatments accelerated myogenin, myosin expression, and myotube formation; although when SB 431542 was present inhibition in myosin induction and myotube formation was observed, suggesting that these last steps of skeletal muscle differentiation require active TGF-{beta}-Rs. These results suggest that both down-regulation of Smad regulatory proteins and cell signaling through the TGF-{beta} receptors independent of Smad proteins are essential for skeletal muscle differentiation.

  1. A novel population of local pericyte precursor cells in tumor stroma that require Notch signaling for differentiation.

    Patenaude, Alexandre; Woerher, Stefan; Umlandt, Patricia; Wong, Fred; Ibrahim, Rawa; Kyle, Alastair; Unger, Sandy; Fuller, Megan; Parker, Jeremy; Minchinton, Andrew; Eaves, Connie J; Karsan, Aly

    2015-09-01

    Pericytes are perivascular support cells, the origin of which in tumor tissue is not clear. Recently, we identified a Tie1(+) precursor cell that differentiates into vascular smooth muscle, in a Notch-dependent manner. To understand the involvement of Notch in the ontogeny of tumor pericytes we used a novel flow immunophenotyping strategy to define CD146(+)/CD45(-)/CD31(-/lo) pericytes in the tumor stroma. This strategy combined with ex vivo co-culture experiments identified a novel pericyte progenitor cell population defined as Sca1(hi)/CD146(-)/CD45(-)/CD31(-). The differentiation of these progenitor cells was stimulated by co-culture with endothelial cells. Overexpression of the Notch ligand Jagged1 in endothelial cells further stimulated the differentiation of Sca1(hi)/CD146(-)/CD45(-)/CD31(-) cells into pericytes, while inhibition of Notch signaling with a γ-secretase inhibitor reduced this differentiation. However, Notch inhibition specifically in Tie1-expressing cells did not change the abundance of pericytes in tumors, suggesting that the pericyte precursor is distinct from the vascular smooth muscle cell precursor. Transplant experiments showed that the bone marrow contributes minimally to tumor pericytes. Immunophenotyping revealed that Sca1(hi)/CD146(-)/CD45(-)/CD31(-) cells have greater potential to differentiate into pericytes and have increased expression of classic mesenchymal stem cell markers (CD13, CD44, Nt5e and Thy-1) compared to Sca1(-/lo)/CD146(-)/CD45(-)/CD31(-) cells. Our results suggest that a local Sca1(hi)/CD146(-)/CD45(-)/CD31(-) pericyte progenitor resides in the tumor microenvironment and requires Notch signaling for differentiation into mature pericytes. PMID:26092680

  2. TGF-β receptors, in a Smad-independent manner, are required for terminal skeletal muscle differentiation

    Skeletal muscle differentiation is strongly inhibited by transforming growth factor type β (TGF-β), although muscle formation as well as regeneration normally occurs in an environment rich in this growth factor. In this study, we evaluated the role of intracellular regulatory Smads proteins as well as TGF-β-receptors (TGF-β-Rs) during skeletal muscle differentiation. We found a decrease of TGF-β signaling during differentiation. This phenomenon is explained by a decline in the levels of the regulatory proteins Smad-2, -3, and -4, a decrease in the phosphorylation of Smad-2 and lost of nuclear translocation of Smad-3 and -4 in response to TGF-β. No change in the levels and inhibitory function of Smad-7 was observed. In contrast, we found that TGF-β-R type I (TGF-β-RI) and type II (TGF-β-RII) increased on the cell surface during skeletal muscle differentiation. To analyze the direct role of the serine/threonine kinase activities of TGF-β-Rs, we used the specific inhibitor SB 431542 and the dominant-negative form of TGF-β-RII lacking the cytoplasmic domain. The TGF-β-Rs were important for successful muscle formation, determined by the induction of myogenin, creatine kinase activity, and myosin. Silencing of Smad-2/3 expression by specific siRNA treatments accelerated myogenin, myosin expression, and myotube formation; although when SB 431542 was present inhibition in myosin induction and myotube formation was observed, suggesting that these last steps of skeletal muscle differentiation require active TGF-β-Rs. These results suggest that both down-regulation of Smad regulatory proteins and cell signaling through the TGF-β receptors independent of Smad proteins are essential for skeletal muscle differentiation.

  3. Pathways commonly dysregulated in mouse and human obese adipose tissue: FAT/CD36 modulates differentiation and lipogenesis.

    Berger, E; Héraud, S; Mojallal, A; Lequeux, C; Weiss-Gayet, M; Damour, O; Géloën, A

    2015-01-01

    Obesity is linked to adipose tissue hypertrophy (increased adipocyte cell size) and hyperplasia (increased cell number). Comparative analyses of gene datasets allowed us to identify 1426 genes which may represent common adipose phenotype in humans and mice. Among them we identified several adipocyte-specific genes dysregulated in obese adipose tissue, involved in either fatty acid storage (acyl CoA synthase ACSL1, hormone-sensitive lipase LIPE, aquaporin 7 AQP7, perilipin PLIN) or cell adhesion (fibronectin FN1, collagens COL1A1, COL1A3, metalloprotein MMP9, or both (scavenger receptor FAT/CD36). Using real-time analysis of cell surface occupancy on xCELLigence system we developed a new method to study lipid uptake and differentiation of mouse 3T3L1 fibroblasts and human adipose stem cells. Both processes are regulated by insulin and fatty acids such as oleic acid. We showed that fatty acid addition to culture media increased the differentiation rate and was required for full differentiation into unilocular adipocytes. Significant activation of lipogenesis, i.e. lipid accumulation, by either insulin or oleic acid was monitored in times ranging from 1 to 24 h, depending on differentiation state, whereas significant effects on adipogenesis, i.e., surperimposed lipid accumulation and gene transcriptional regulations were measured after 3 to 4 d. Combination of selected times for analysis of lipid contents, cell counts, size fractionations, and gene transcriptional regulations showed that FAT/CD36 specific inhibitor AP5258 significantly increased cell survival of oleic acid-treated mouse and human adipocytes, and partially restored the transcriptional response to oleic acid in the presence of insulin through JNK pathway. Taken together, these data open new perspectives to study the molecular mechanisms commonly dysregulated in mouse and human obesity at the level of lipogenesis linked to hypertrophy and adipogenesis linked to hyperplasia. PMID:26257990

  4. Actin-associated protein palladin is required for migration behavior and differentiation potential of C2C12 myoblast cells

    Highlights: • Palladin is involved in myogenesis in vitro. • Palladin knockdown by siRNA increases myoblast proliferation, viability and differentiation. • Palladin knockdown decreases C2C12 myoblast migration ability. - Abstract: The actin-associated protein palladin has been shown to be involved in differentiation processes in non-muscle tissues. However, but its function in skeletal muscle has rarely been studied. Palladin plays important roles in the regulation of diverse actin-related signaling in a number of cell types. Since intact actin-cytoskeletal remodeling is necessary for myogenesis, in the present study, we pursue to investigate the role of actin-associated palladin in skeletal muscle differentiation. Palladin in C2C12 myoblasts is knocked-down using specific small interfering RNA (siRNA). The results show that down-regulation of palladin decreased migratory activity of mouse skeletal muscle C2C12 myoblasts. Furthermore, the depletion of palladin enhances C2C12 vitality and proliferation. Of note, the loss of palladin promotes C2C12 to express the myosin heavy chain, suggesting that palladin has a role in the modulation of C2C12 differentiation. It is thus proposed that palladin is required for normal C2C12 myogenesis in vitro

  5. Actin-associated protein palladin is required for migration behavior and differentiation potential of C2C12 myoblast cells

    Nguyen, Ngoc Uyen Nhi; Liang, Vincent Roderick; Wang, Hao-Ven, E-mail: hvwang@mail.ncku.edu.tw

    2014-09-26

    Highlights: • Palladin is involved in myogenesis in vitro. • Palladin knockdown by siRNA increases myoblast proliferation, viability and differentiation. • Palladin knockdown decreases C2C12 myoblast migration ability. - Abstract: The actin-associated protein palladin has been shown to be involved in differentiation processes in non-muscle tissues. However, but its function in skeletal muscle has rarely been studied. Palladin plays important roles in the regulation of diverse actin-related signaling in a number of cell types. Since intact actin-cytoskeletal remodeling is necessary for myogenesis, in the present study, we pursue to investigate the role of actin-associated palladin in skeletal muscle differentiation. Palladin in C2C12 myoblasts is knocked-down using specific small interfering RNA (siRNA). The results show that down-regulation of palladin decreased migratory activity of mouse skeletal muscle C2C12 myoblasts. Furthermore, the depletion of palladin enhances C2C12 vitality and proliferation. Of note, the loss of palladin promotes C2C12 to express the myosin heavy chain, suggesting that palladin has a role in the modulation of C2C12 differentiation. It is thus proposed that palladin is required for normal C2C12 myogenesis in vitro.

  6. Obesity Beige adipocytes-will they beat obesity?

    Sandholt, Camilla H.; Pedersen, Oluf.

    2015-01-01

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

  7. Dicer is required for haploid male germ cell differentiation in mice.

    Hanna M Korhonen

    Full Text Available BACKGROUND: The RNase III endonuclease Dicer is an important regulator of gene expression that processes microRNAs (miRNAs and small interfering RNAs (siRNAs. The best-characterized function of miRNAs is gene repression at the post-transcriptional level through the pairing with mRNAs of protein-encoding genes. Small RNAs can also act at the transcriptional level by controlling the epigenetic status of chromatin. Dicer and other mediators of small RNA pathways are present in mouse male germ cells, and several miRNAs and endogenous siRNAs are expressed in the testis, suggesting that Dicer-dependent small RNAs are involved in the control of the precisely timed and highly organised process of spermatogenesis. PRINCIPAL FINDINGS: Being interested in the Dicer-mediated functions during spermatogenesis, we have analysed here a male germ cell-specific Dicer1 knockout mouse model, in which the deletion of Dicer1 takes place during early postnatal development in spermatogonia. We found that Dicer1 knockout testes were reduced in size and spermatogenesis within the seminiferous tubules was disrupted. Dicer1 knockout epididymides contained very low number of mature sperm with pronounced morphological abnormalities. Spermatogonial differentiation appeared unaffected. However, the number of haploid cells was decreased in knockout testes, and an increased number of apoptotic spermatocytes was observed. The most prominent defects were found during late haploid differentiation, and Dicer was demonstrated to be critical for the normal organization of chromatin and nuclear shaping of elongating spermatids. CONCLUSIONS/SIGNIFICANCE: We demonstrate that Dicer and Dicer-dependent small RNAs are imperative regulators of haploid spermatid differentiation and essential for male fertility.

  8. Mind bomb-1 in dendritic cells is specifically required for Notch-mediated T helper type 2 differentiation.

    Hyun-Woo Jeong

    Full Text Available In dendritic cell (DC-CD4(+ T cell interaction, Notch signaling has been implicated in the CD4(+ T cell activation, proliferation, and subset differentiation. However, there has been a lot of debate on the exact role of Notch signaling. Here, we observed that expression of Mind bomb-1 (Mib1, a critical regulator of Notch ligands for the activation of Notch signaling, increases gradually as precursor cells differentiate into DCs in mice. To clarify the role of Mib1 in DC-CD4(+ T cell interactions, we generated Mib1-null bone marrow-derived DCs. These cells readily expressed Notch ligands but failed to initiate Notch activation in the adjacent cells. Nevertheless, Mib1-null DCs were able to prime the activation and proliferation of CD4(+ T cells, suggesting that Notch activation in CD4(+ T cells is not required for these processes. Intriguingly, stimulation of CD4(+ T cells with Mib1-null DCs resulted in dramatically diminished Th2 cell populations, while preserving Th1 cell populations, both in vitro and in vivo. Our results demonstrate that Mib1 in DCs is critical for the activation of Notch signaling in CD4(+ T cells, and Notch signaling reinforces Th2 differentiation, but is not required for the activation or proliferation of the CD4(+ T cells.

  9. Smad3 signaling is required for satellite cell function and myogenic differentiation of myoblasts

    Xiaojia Ge; Ravi Kambadur; Craig McFarlane; Anuradha Vajjala; Sudarsanareddy Lokireddy; Zhi Hui Ng; Chek Kun Tan; Nguan Soon Tan; Walter Wahli; Mridula Sharma

    2011-01-01

    TGF-β and myostatin are the two most important regulators of muscle growth.Both growth factors have been shown to signal through a Smad3-dependent pathway.However to date,the role of Smad3 in muscle growth and differentiation is not investigated.Here,we demonstrate that Smad3-null mice have decreased muscle mass and pronounced skeletal muscle atrophy.Consistent with this,we also find increased protein ubiquitination and elevated levels of the ubiquitin E3 ligase MuRF1 in muscle tissue isolated from Smad3-null mice.Loss of Smad3 also led to defective satellite cell (SC) functionality.Smad3-null SCs showed reduced propensity for self-renewal,which may lead to a progressive loss of SC number.Indeed,decreased SC number was observed in skeletal muscle from Smad3- null mice showing signs of severe muscle wasting.Further in vitro analysis of primary myoblast cultures identified that Smad3-nuil myoblasts exhibit impaired proliferation,differentiation and fusion,resulting in the formation of atrophied myotubes.A search for the molecular mechanism revealed that loss of Smad3 results in increased myostatin expression in Smad3-null muscle and myoblasts.Given that myostatin is a negative regulator,we hypothesize that increased myostatin levels are responsible for the atrophic phenotype in Smad3-null mice.Consistent with this theory,inactivation of myostatin in Smad3-null mice rescues the muscle atrophy phenotype.

  10. Somitogenesis clock-wave initiation requires differential decay and multiple binding sites for clock protein.

    Mark Campanelli

    2010-04-01

    Full Text Available Somitogenesis is a process common to all vertebrate embryos in which repeated blocks of cells arise from the presomitic mesoderm (PSM to lay a foundational pattern for trunk and tail development. Somites form in the wake of passing waves of periodic gene expression that originate in the tailbud and sweep posteriorly across the PSM. Previous work has suggested that the waves result from a spatiotemporally graded control protein that affects the oscillation rate of clock-gene expression. With a minimally constructed mathematical model, we study the contribution of two control mechanisms to the initial formation of this gene-expression wave. We test four biologically motivated model scenarios with either one or two clock protein transcription binding sites, and with or without differential decay rates for clock protein monomers and dimers. We examine the sensitivity of wave formation with respect to multiple model parameters and robustness to heterogeneity in cell population. We find that only a model with both multiple binding sites and differential decay rates is able to reproduce experimentally observed waveforms. Our results show that the experimentally observed characteristics of somitogenesis wave initiation constrain the underlying genetic control mechanisms.

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

    Sabrina Krautbauer

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

  12. Contributions of Cytogenetics and Molecular Cytogenetics to the Diagnosis of Adipocytic Tumors

    Jun Nishio

    2011-01-01

    Full Text Available Over the last 20 years, a number of tumor-specific chromosomal translocations and associated fusion genes have been identified for mesenchymal neoplasms including adipocytic tumors. The addition of molecular cytogenetic techniques, especially fluorescence in situ hybridization (FISH, has further enhanced the sensitivity and accuracy of detecting nonrandom chromosomal translocations and/or other rearrangements in adipocytic tumors. Indeed, most resent molecular cytogenetic analysis has demonstrated a translocation t(11;16(q13;p13 that produces a C11orf95-MKL2 fusion gene in chondroid lipoma. Additionally, it is well recognized that supernumerary ring and/or giant rod chromosomes are characteristic for atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma, and amplification of 12q13–15 involving the MDM2, CDK4, and CPM genes is shown by FISH in these tumors. Moreover, myxoid/round cell liposarcoma is characterized by a translocation t(12;16(q13;p11 that fuses the DDIT3 and FUS genes. This paper provides an overview of the role of conventional cytogenetics and molecular cytogenetics in the diagnosis of adipocytic tumors.

  13. Malic enzyme tracers reveal hypoxia-induced switch in adipocyte NADPH pathway usage.

    Liu, Ling; Shah, Supriya; Fan, Jing; Park, Junyoung O; Wellen, Kathryn E; Rabinowitz, Joshua D

    2016-05-01

    The critical cellular hydride donor NADPH is produced through various means, including the oxidative pentose phosphate pathway (oxPPP), folate metabolism and malic enzyme. In growing cells, it is efficient to produce NADPH via the oxPPP and folate metabolism, which also make nucleotide precursors. In nonproliferating adipocytes, a metabolic cycle involving malic enzyme holds the potential to make both NADPH and two-carbon units for fat synthesis. Recently developed deuterium ((2)H) tracer methods have enabled direct measurement of NADPH production by the oxPPP and folate metabolism. Here we enable tracking of NADPH production by malic enzyme with [2,2,3,3-(2)H]dimethyl-succinate and [4-(2)H]glucose. Using these tracers, we show that most NADPH in differentiating 3T3-L1 mouse adipocytes is made by malic enzyme. The associated metabolic cycle is disrupted by hypoxia, which switches the main adipocyte NADPH source to the oxPPP. Thus, (2)H-labeled tracers enable dissection of NADPH production routes across cell types and environmental conditions. PMID:26999781

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

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

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

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

    2011-10-01

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

  16. A powerful method for detecting differentially expressed genes from GeneChip arrays that does not require replicates

    Hein Anne-Mette K

    2006-07-01

    Full Text Available Abstract Background Studies of differential expression that use Affymetrix GeneChip arrays are often carried out with a limited number of replicates. Reasons for this include financial considerations and limits on the available amount of RNA for sample preparation. In addition, failed hybridizations are not uncommon leading to a further reduction in the number of replicates available for analysis. Most existing methods for studying differential expression rely on the availability of replicates and the demand for alternative methods that require few or no replicates is high. Results We describe a statistical procedure for performing differential expression analysis without replicates. The procedure relies on a Bayesian integrated approach (BGX to the analysis of Affymetrix GeneChips. The BGX method estimates a posterior distribution of expression for each gene and condition, from a simultaneous consideration of the available probe intensities representing the gene in a condition. Importantly, posterior distributions of expression are obtained regardless of the number of replicates available. We exploit these posterior distributions to create ranked gene lists that take into account the estimated expression difference as well as its associated uncertainty. We estimate the proportion of non-differentially expressed genes empirically, allowing an informed choice of cut-off for the ranked gene list, adapting an approach proposed by Efron. We assess the performance of the method, and compare it to those of other methods, on publicly available spike-in data sets, as well as in a proper biological setting. Conclusion The method presented is a powerful tool for extracting information on differential expression from GeneChip expression studies with limited or no replicates.

  17. Differential requirement for SUB1 in chromosomal and plasmid double-strand DNA break repair.

    Lijian Yu

    Full Text Available Non homologous end joining (NHEJ is an important process that repairs double strand DNA breaks (DSBs in eukaryotic cells. Cells defective in NHEJ are unable to join chromosomal breaks. Two different NHEJ assays are typically used to determine the efficiency of NHEJ. One requires NHEJ of linearized plasmid DNA transformed into the test organism; the other requires NHEJ of a single chromosomal break induced either by HO endonuclease or the I-SceI restriction enzyme. These two assays are generally considered equivalent and rely on the same set of NHEJ genes. PC4 is an abundant DNA binding protein that has been suggested to stimulate NHEJ. Here we tested the role of PC4's yeast homolog SUB1 in repair of DNA double strand breaks using different assays. We found SUB1 is required for NHEJ repair of DSBs in plasmid DNA, but not in chromosomal DNA. Our results suggest that these two assays, while similar are not equivalent and that repair of plasmid DNA requires additional factor(s that are not required for NHEJ repair of chromosomal double-strand DNA breaks. Possible roles for Sub1 proteins in NHEJ of plasmid DNA are discussed.

  18. Influence of lipolysis on the mobilization of 2,4,5,2'4',5'-hexachlorobiphenyl from adipocytes in vitro

    Gallenberg, L.A.; Ring, B.J.; Vodicnik, M.J.

    1987-01-01

    Epididymal adipocytes, isolated from rats pretreated with (/sup 14/C)-2,4,5,2',4',5'-hexachlorobiphenyl (6-CB), were utilized to examine the relationship between the mobilization of lipid and 6-CB and to determine whether 6-CB was differentially associated with subcellular organelles over time as has been demonstrated for newly synthesized lipid. Lipolysis, depleted approximately 1% of total cellular triacylglycerols (TG) regardless of time from treatment with 6-CB. The percentage of cellular 6-CB released from adipocytes to incubation buffer infranatants was not correlated with the magnitude of lipolysis produced over the 50-min incubation period; nor was the percentage of 6-CB released to the buffers correlated with the length of the incubation period, regardless of the presence of ISO. Although adipocytes responded similarly to lipolytic stimuli independent of time (days) since 6-CB treatment, significant decreases were found in the percentage of 6-CB released from adipocytes over time. The in vitro labeling of this newly synthesized TG in fat cells with (U-/sup 14/C)glucose or (1-/sup 14/C)palmitate demonstrated that TG was differentially distributed among adipocyte organelles. Newly synthesized TG was also the first to be mobilized under lipolytic stimulus. 6-CB was not released in a similar fashion, since radioactivity associated with the chemical levels of (/sup 14/C)-6-CB and glucose-derived /sup 14/C in buffers were not correlated over time.

  19. Hes1 is required for appropriate morphogenesis and differentiation during mouse thyroid gland development.

    Aurore Carre

    Full Text Available Notch signalling plays an important role in endocrine development, through its target gene Hes1. Hes1, a bHLH transcriptional repressor, influences progenitor cell proliferation and differentiation. Recently, Hes1 was shown to be expressed in the thyroid and regulate expression of the sodium iodide symporter (Nis. To investigate the role of Hes1 for thyroid development, we studied thyroid morphology and function in mice lacking Hes1. During normal mouse thyroid development, Hes1 was detected from E9.5 onwards in the median anlage, and at E11.5 in the ultimobranchial bodies. Hes1(-/- mouse embryos had a significantly lower number of Nkx2-1-positive progenitor cells (p<0.05 at E9.5 and at E11.5. Moreover, Hes1(-/- mouse embryos showed a significantly smaller total thyroid surface area (-40 to -60% compared to wild type mice at all study time points (E9.5-E16.5. In both Hes1(-/- and wild type mouse embryos, most Nkx2-1-positive thyroid cells expressed the cell cycle inhibitor p57 at E9.5 in correlation with low proliferation index. In Hes1(-/- mouse embryos, fusion of the median anlage with the ultimobranchial bodies was delayed by 3 days (E16.5 vs. E13.5 in wild type mice. After fusion of thyroid anlages, hypoplastic Hes1(-/- thyroids revealed a significantly decreased labelling area for T4 (-78% and calcitonin (-65% normalized to Nkx2-1 positive cells. Decreased T4-synthesis might be due to reduced Nis labelling area (-69%. These findings suggest a dual role of Hes1 during thyroid development: first, control of the number of both thyrocyte and C-cell progenitors, via a p57-independent mechanism; second, adequate differentiation and endocrine function of thyrocytes and C-cells.

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

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

    2015-05-01

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

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

    Wenting eXin

    2013-03-01

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

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

    Wenck Horst

    2009-05-01

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

  3. Leptin differentially regulates STAT3 activation in the ob/ob mice adipose mesenchymal stem cells

    Leptin-deficient genetically obese ob/ob mice exhibit adipocyte hypertrophy and hyperplasia as well as elevated adipose tissue and systemic inflammation. Studies have shown that multipotent stem cells isolated from adult adipose tissue can differentiate into adipocytes ex vivo and thereby contribute...

  4. The Mi-2-like Smed-CHD4 gene is required for stem cell differentiation in the planarian Schmidtea mediterranea.

    Scimone, M Lucila; Meisel, Joshua; Reddien, Peter W

    2010-04-01

    Freshwater planarians are able to regenerate any missing part of their body and have extensive tissue turnover because of the action of dividing cells called neoblasts. Neoblasts provide an excellent system for in vivo study of adult stem cell biology. We identified the Smed-CHD4 gene, which is predicted to encode a chromatin-remodeling protein similar to CHD4/Mi-2 proteins, as required for planarian regeneration and tissue homeostasis. Following inhibition of Smed-CHD4 with RNA interference (RNAi), neoblast numbers were initially normal, despite an inability of the animals to regenerate. However, the proliferative response of neoblasts to amputation or growth stimulation in Smed-CHD4(RNAi) animals was diminished. Smed-CHD4(RNAi) animals displayed a dramatic reduction in the numbers of certain neoblast progeny cells. Smed-CHD4 was required for the formation of these neoblast progeny cells. Together, these results indicate that Smed-CHD4 is required for neoblasts to produce progeny cells committed to differentiation in order to control tissue turnover and regeneration and suggest a crucial role for CHD4 proteins in stem cell differentiation. PMID:20223763

  5. Differential requirement for irf8 in formation of embryonic and adult macrophages in zebrafish.

    Celia E Shiau

    Full Text Available Interferon regulatory factor 8 (Irf8 is critical for mammalian macrophage development and innate immunity, but its role in teleost myelopoiesis remains incompletely understood. In particular, genetic tools to analyze the role of Irf8 in zebrafish macrophage development at larval and adult stages are lacking. We generated irf8 null mutants in zebrafish using TALEN-mediated targeting. Our analysis defines different requirements for irf8 at different stages. irf8 is required for formation of all macrophages during primitive and transient definitive hematopoiesis, but not during adult-phase definitive hematopoiesis starting at 5-6 days postfertilization. At early stages, irf8 mutants have excess neutrophils and excess cell death in pu.1-expressing myeloid cells. Macrophage fates were recovered in irf8 mutants after wildtype irf8 expression in neutrophil and macrophage lineages, suggesting that irf8 regulates macrophage specification and survival. In juvenile irf8 mutant fish, mature macrophages are present, but at numbers significantly reduced compared to wildtype, indicating an ongoing requirement for irf8 after embryogenesis. As development progresses, tissue macrophages become apparent in zebrafish irf8 mutants, with the possible exception of microglia. Our study defines distinct requirement for irf8 in myelopoiesis before and after transition to the adult hematopoietic system.

  6. File list: Oth.Adp.05.AllAg.Pre-adipocytes [Chip-atlas[Archive

    Full Text Available Oth.Adp.05.AllAg.Pre-adipocytes hg19 TFs and others Adipocyte Pre-adipocytes SRX760...968,SRX760970,SRX760967,SRX760971,SRX760969 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Adp.05.AllAg.Pre-adipocytes.bed ...

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

    Full Text Available His.Adp.10.AllAg.Pre-adipocytes hg19 Histone Adipocyte Pre-adipocytes SRX760965,SRX...760962,SRX760966,SRX760964,SRX760963 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.Adp.10.AllAg.Pre-adipocytes.bed ...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  4. The PPARgamma-selective ligand BRL-49653 differentially regulates the fate choices of rat calvaria versus rat bone marrow stromal cell populations

    Yoshiko Yuji

    2008-07-01

    Full Text Available Abstract Background Osteoblasts and adipocytes are derived from a common mesenchymal progenitor and an inverse relationship between expression of the two lineages is seen with certain experimental manipulations and in certain diseases, i.e., osteoporosis, but the cellular pathway(s and developmental stages underlying the inverse relationship is still under active investigation. To determine which precursor mesenchymal cell types can differentiate into adipocytes, we compared the effects of BRL-49653 (BRL, a selective ligand for peroxisome proliferators-activated receptor (PPARγ, a master transcription factor of adipogenesis, on osteo/adipogeneis in two different osteoblast culture models: the rat bone marrow (RBM versus the fetal rat calvaria (RC cell system. Results BRL increased the number of adipocytes and corresponding marker expression, such as lipoprotein lipase, fatty acid-binding protein (aP2, and adipsin, in both culture models, but affected osteoblastogenesis only in RBM cultures, where a reciprocal decrease in bone nodule formation and osteoblast markers, e.g., osteopontin, alkaline phosphatase (ALP, bone sialoprotein, and osteocalcin was seen, and not in RC cell cultures. Even though adipocytes were histologically undetectable in RC cultures not treated with BRL, RC cells expressed PPAR and CCAAT/enhancer binding protein (C/EBP mRNAs throughout osteoblast development and their expression was increased by BRL. Some single cell-derived BRL-treated osteogenic RC colonies were stained not only with ALP/von Kossa but also with oil red O and co-expressed the mature adipocyte marker adipsin and the mature osteoblast marker OCN, as well as PPAR and C/EBP mRNAs. Conclusion The data show that there are clear differences in the capacity of BRL to alter the fate choices of precursor cells in stromal (RBM versus calvarial (RC cell populations and that recruitment of adipocytes can occur from multiple precursor cell pools (committed preadipocyte

  5. Novel Function of Serine Protease HTRA1 in Inhibiting Adipogenic Differentiation of Human Mesenchymal Stem Cells via MAP Kinase-Mediated MMP Upregulation.

    Tiaden, André N; Bahrenberg, Gregor; Mirsaidi, Ali; Glanz, Stephan; Blüher, Matthias; Richards, Peter J

    2016-06-01

    Adipogenesis is the process by which mesenchymal stem cells (MSCs) develop into lipid-laden adipocytes. Being the dominant cell type within adipose tissue, adipocytes play a central role in regulating circulating fatty acid levels, which is considered to be of critical importance in maintaining insulin sensitivity. High temperature requirement protease A1 (HTRA1) is a newly recognized regulator of MSC differentiation, although its role as a mediator of adipogenesis has not yet been defined. The aim of this work was therefore to evaluate HTRA1's influence on human MSC (hMSC) adipogenesis and to establish a potential mode of action. We report that the addition of exogenous HTRA1 to hMSCs undergoing adipogenesis suppressed their ability to develop into lipid laden adipocytes. These effects were demonstrated as being reliant on both its protease and PDZ domain, and were mediated through the actions of c-Jun N-terminal kinase and matrix metalloproteinases (MMPs). The relevance of such findings with regards to HTRA1's potential influence on adipocyte function in vivo is made evident by the fact that HTRA1 and MMP-13 were readily identifiable within crown-like structures present in visceral adipose tissue samples from insulin resistant obese human subjects. These data therefore implicate HTRA1 as a negative regulator of MSC adipogenesis and are suggestive of its potential involvement in adipose tissue remodeling under pathological conditions. Stem Cells 2016;34:1601-1614. PMID:26864869

  6. Lactobacillus plantarum LG42 Isolated from Gajami Sik-Hae Inhibits Adipogenesis in 3T3-L1 Adipocyte

    Jeong-Eun Park

    2013-01-01

    Full Text Available We investigated whether lactic acid bacteria isolated from gajami sik-hae (GLAB are capable of reducing the intracellular lipid accumulation by downregulating the expression of adipogenesis-related genes in differentiated 3T3-L1 cells. The GLAB, Lactobacillus plantarum LG42, significantly decreased the intracellular triglyceride storage and the glycerol-3-phosphate dehydrogenase (GPDH activity in a dose-dependent manner. mRNA expression of transcription factors like peroxisome proliferator-activated receptor (PPAR γ and CCAAT/enhancer-binding protein (C/EBP α involved in adipogenesis was markedly decreased by the GLAB treatment. Moreover, the GLAB also decreased the expression level of adipogenic markers like adipocyte fatty acid binding protein (aP2, leptin, GPDH, and fatty acid translocase (CD36 significantly. These results suggest that the GLAB inhibits lipid accumulation in the differentiated adipocyte through downregulating the expression of adipogenic transcription factors and other specific genes involved in lipid metabolism.

  7. Xbp1-Independent Ire1 Signaling Is Required for Photoreceptor Differentiation and Rhabdomere Morphogenesis in Drosophila

    Dina S. Coelho

    2013-11-01

    Full Text Available The unfolded protein response (UPR is composed by homeostatic signaling pathways that are activated by excessive protein misfolding in the endoplasmic reticulum. Ire1 signaling is an important mediator of the UPR, leading to the activation of the transcription factor Xbp1. Here, we show that Drosophila Ire1 mutant photoreceptors have defects in the delivery of rhodopsin-1 to the rhabdomere and in the secretion of Spacemaker/Eyes Shut into the interrhabdomeral space. However, these defects are not observed in Xbp1 mutant photoreceptors. Ire1 mutant retinas have higher mRNA levels for targets of regulated Ire1-dependent decay (RIDD, including for the fatty acid transport protein (fatp. Importantly, the downregulation of fatp by RNAi rescues the rhodopsin-1 delivery defects observed in Ire1 mutant photoreceptors. Our results show that the role of Ire1 during photoreceptor differentiation is independent of Xbp1 function and demonstrate the physiological relevance of the RIDD mechanism in this specific paradigm.

  8. Mode of Bioenergetic Metabolism during B Cell Differentiation in the Intestine Determines the Distinct Requirement for Vitamin B1

    Jun Kunisawa

    2015-10-01

    Full Text Available Bioenergetic metabolism varies during cell differentiation, but details of B cell metabolism remain unclear. Here, we show the metabolic changes during B cell differentiation in the intestine, where B cells differentiate into IgA+ plasma cells (PCs. Naive B cells in the Peyer’s patches (PPs and IgA+ PCs in the intestinal lamina propria (iLP both used the tricarboxylic acid (TCA cycle, but only IgA+ PCs underwent glycolysis. These metabolic differences reflected their dependencies on vitamin B1, an essential cofactor for the TCA cycle. Indeed, the diminished activity of the TCA cycle after dietary vitamin B1 depletion decreased the number of naive B cells in PPs without affecting IgA+ PCs in the iLP. The maintenance of naive B cells by dietary vitamin B1 was required to induce—but not maintain—intestinal IgA responses against oral antigens. These findings reveal the diet-mediated maintenance of B cell immunometabolism in organized and diffuse intestinal tissues.

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

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

    2016-08-01

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

  10. Differential requirement for MEK Partner 1 in DU145 prostate cancer cell migration

    Bailey Evangeline M

    2009-11-01

    Full Text Available Abstract ERK signaling regulates focal adhesion disassembly during cell movement, and increased ERK signaling frequently contributes to enhanced motility of human tumor cells. We previously found that the ERK scaffold MEK Partner 1 (MP1 is required for focal adhesion disassembly in fibroblasts. Here we test the hypothesis that MP1-dependent ERK signaling regulates motility of DU145 prostate cancer cells. We find that MP1 is required for motility on fibronectin, but not for motility stimulated by serum or EGF. Surprisingly, MP1 appears not to function through its known binding partners MEK1 or PAK1, suggesting the existence of a novel pathway by which MP1 can regulate motility on fibronectin. MP1 may function by regulating the stability or expression of paxillin, a key regulator of motility.

  11. Differential requirement of GRP94 and GRP78 in mammary gland development

    Genyuan Zhu; Miao Wang; Benjamin Spike; Gray, Peter C.; Jieli Shen; Sung-Hyung Lee; Si-Yi Chen; Lee, Amy S.

    2014-01-01

    Glucose Regulated Protein (GRP) 94 and GRP78 are critical molecular chaperones and regulators of signaling. Conditional knockout mouse models have revealed tissue specific requirements for GRP94 and GRP78, including selection for allele retention in specific cell types. Here we report the consequences of mammary-targeted knockout of these GRPs. Our studies revealed that MMTV-Cre, Grp94f/f mammary glands, despite GRP94 deficiency, exhibited normal proliferation and ductal morphogenesis. Intere...

  12. Differential requirements of singleplex and multiplex recombineering of large DNA constructs.

    Thimma R Reddy

    Full Text Available Recombineering is an in vivo genetic engineering technique involving homologous recombination mediated by phage recombination proteins. The use of recombineering methodology is not limited by size and sequence constraints and therefore has enabled the streamlined construction of bacterial strains and multi-component plasmids. Recombineering applications commonly utilize singleplex strategies and the parameters are extensively tested. However, singleplex recombineering is not suitable for the modification of several loci in genome recoding and strain engineering exercises, which requires a multiplex recombineering design. Defining the main parameters affecting multiplex efficiency especially the insertion of multiple large genes is necessary to enable efficient large-scale modification of the genome. Here, we have tested different recombineering operational parameters of the lambda phage Red recombination system and compared singleplex and multiplex recombineering of large gene sized DNA cassettes. We have found that optimal multiplex recombination required long homology lengths in excess of 120 bp. However, efficient multiplexing was possible with only 60 bp of homology. Multiplex recombination was more limited by lower amounts of DNA than singleplex recombineering and was greatly enhanced by use of phosphorothioate protection of DNA. Exploring the mechanism of multiplexing revealed that efficient recombination required co-selection of an antibiotic marker and the presence of all three Red proteins. Building on these results, we substantially increased multiplex efficiency using an ExoVII deletion strain. Our findings elucidate key differences between singleplex and multiplex recombineering and provide important clues for further improving multiplex recombination efficiency.

  13. Female adipocyte androgen synthesis and the effects of insulin

    David Cadagan

    2014-01-01

    Full Text Available The metabolic syndrome is a cluster of metabolic disorders characterized by insulin resistance and hyperinsulinaemia, and its presence can increase the risk of cardiovascular disease significantly. The metabolic syndrome is associated with increased circulating androgen levels in women, which may originate from the ovaries and adrenal glands. Adipocytes are also able to synthesise steroid hormones, and this output has been hypothesised to increase with elevated insulin plasma concentrations. However, the contribution of the adipocytes to the circulating androgen levels in women with metabolic syndrome is limited and the effects of insulin are not fully understood. The aim of this study was to investigate the presence of steroid precursors and synthetic enzymes in human adipocyte biopsies as markers of possible adipocyte androgen synthesis. We examined pre and mature adipocytes taken from tissue biopsies of abdominal subcutaneous adipose tissue of participating women from the Department of Obstetrics and Gynaecology, of the Royal Derby Hospital. The results showed the potential for localised adipocyte androgen synthesis through the presence of the androgen precursor progesterone, as well as the steroid-converting enzyme 17α-hydroxylase. Furthermore, we found the controlled secretion of androstenedione in vitro and that insulin treatment caused levels to increase. Continued examination of a localised source of androgen production is therefore of clinical relevance due to its influence on adipocyte metabolism, its negative impact on female steroidogenic homeostasis, and the possible aggravation this may have when associated to obesity and obesity related metabolic abnormalities such as hyperinsulinaemia.

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

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

    2012-06-01

    Adipose tissue (AT) dysfunction links obesity of any cause with cardiometabolic disease, but whether early-life nutritional deficiency can program adipocyte dysfunction independently of obesity is untested. In 3-5-month-old juvenile microswine offspring exposed to isocaloric perinatal maternal protein restriction (MPR) and exhibiting accelerated prepubertal fat accrual without obesity, we assessed markers of acquired obesity: adiponectin and tumor necrosis factor (TNF)-α messenger ribonucleic acid (mRNA) levels and adipocyte size in intra-abdominal (ABD-AT) and subcutaneous (SC-AT) adipose tissues. Plasma cortisol, leptin and insulin levels were measured in fetal, neonatal and juvenile offspring. In juvenile low-protein offspring (LPO), adipocyte size in ABD-AT was reduced 22% (P = 0.011 v. controls), whereas adipocyte size in SC-AT was increased in female LPO (P = 0.05) and normal in male LPO; yet, adiponectin mRNA in LPO was low in both sexes and in both depots (P programming of adipocyte size and gene expression and subtly altered glucose homeostasis. Reduced adiponectin mRNA and adipokine dysregulation in juvenile LPO following accelerated growth occurred independently of obesity, adipocyte hypertrophy or inflammatory markers; thus, perinatal MPR and/or growth acceleration can alter adipocyte structure and disturb adipokine homeostasis in metabolically adverse patterns predictive of enhanced disease risk. PMID:25102010

  15. Verapamil inhibits 3T3-L1 preadipocyte differentiation

    Nan Gu; Shi Liu; Xirong Guo; Li Fei; Xiaoqin Pan; Mei Guo; Ronghua Chen

    2009-01-01

    Objective: To investigate the effect of the calcium channel blocker verapamil on adipocyte differentiation and its mechanism of action. Methods: Preadipocytes from 3T3-L1 strain mouse embryos were cultured and differentiated into matured adipocytes in vitro. Verapamil was added to the culture medium in the concentration of 30 μmol/L on Day 0. Cell differentiation was determined by Oil Red O staining and marker gene mRNA expression was evaluated and compared by RT-PCR. The fluo-3/AM probe and laser scanning confocal microscopy were used to measure intracellular calcium concentrations. Results: ①The differentiation rate of 3T3-L1 preadipocytes exposed to verapamil was lower than that of untreated cells. ②Verapamil promoted the retention of pref-1 gene expression. Lipoprotein lipase expression in the verapamil group was significantly lower than that in the control group on Day 4, Day 6 and Day 8 (P 0.05). Conclusion: In 3T3-L1 preadipocytes verapamil significantly reduced adipocyte differentiation, down-regulated the mRNA expression of three marker genes for adipocytes differentiation, and prolonged the mRNA expression of an inhibitor of differentiation. The inhibitory effect of verapamil on differentiation may involve its role as a blocker of calcium influx in adipocytes.

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

    Lucia Berti

    2015-07-01

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

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

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

    2011-01-01

    Background: Overactivity and/or dysregulation of the endocannabinoid system (ECS) contribute to development of obesity. In vitro studies indicate a regulatory role for the cannabinoid receptor 1 (CB1) in adipocyte function and CB1-receptor deficient (CB1-/-) mice are resistant to high fat diet-induced obesity. Whether this phenotype of CB1-/- mice is related to altered fat metabolism in adipose tissue is unknown. Methods: We evaluated adipose tissue differentiation/proliferation markers and q...

  18. Regulated expression of the obese gene product (leptin) in white adipose tissue and 3T3-L1 adipocytes.

    MacDougald, O A; Hwang, C. S.; Fan, H; Lane, M D

    1995-01-01

    A mutation within the obese gene was recently identified as the genetic basis for obesity in the ob/ob mouse. The obese gene product, leptin, is a 16-kDa protein expressed predominantly in adipose tissue. Consistent with leptin's postulated role as an extracellular signaling protein, human embryonic kidney 293 cells transfected with the obese gene secreted leptin with minimal intracellular accumulation. Upon differentiation of 3T3-L1 preadipocytes into adipocytes, the leptin mRNA was expresse...

  19. Inhibition of Adipogenesis by Oligonol through Akt-mTOR Inhibition in 3T3-L1 Adipocytes

    Jae-Yeo Park; Younghwa Kim; Jee Ae Im; Seungkwon You; Hyangkyu Lee

    2014-01-01

    Polyphenols have recently become an important focus of study in obesity research. Oligonol is an oligomerized polyphenol, typically comprised of catechin-type polyphenols from a variety of fruits, which has been found to exhibit better bioavailability and bioreactivity than natural polyphenol compounds. Here, we demonstrated that Oligonol inhibits 3T3-L1 adipocyte differentiation by reducing adipogenic gene expression. During adipogenesis, Oligonol downregulated the mRNA levels of peroxisome ...

  20. Conjugated Linoleic Acid Induces Human Adipocyte Delipidation: AUTOCRINE/PARACRINE REGULATION OF MEK/ERK SIGNALING BY ADIPOCYTOKINES*

    Brown, J. Mark; Boysen, Maria Sandberg; Chung, Soonkyu; Fabiyi, Olowatoyin; Ron F Morrison; Mandrup, Susanne; McIntosh1, Michael K.

    2004-01-01

    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 recepto...