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Cahyadi DD, Warita K, Takeda-Okuda N, Tamura JI, Hosaka YZ. Qualitative and quantitative analyses in sulfated glycosaminoglycans, chondroitin sulfate/dermatan sulfate, during 3 T3-L1 adipocytes differentiation. Anim Sci J 2023; 94:e13894. [PMID: 38054387 DOI: 10.1111/asj.13894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 10/31/2023] [Accepted: 11/06/2023] [Indexed: 12/07/2023]
Abstract
Chondroitin sulfate/dermatan sulfate (CS/DS) is a member of glycosaminoglycans (GAGs) found in animal tissues. Major CS/DS subclasses, O, A, C, D, and E units, exist based on the sulfation pattern in d-glucuronic acid (GlcA) and N-acetyl-d-galactosamine repeating units. DS is formed when GlcA is epimerized into l-iduronic acid. Our study aimed to analyze the CS/DS profile in 3 T3-L1 cells before and after adipogenic induction. CS/DS contents, molecular weight (Mw), and sulfation pattern were analyzed by using high-performance liquid chromatography. CS/DS synthesis- and sulfotransferase-related genes were analyzed by reverse transcription real-time PCR. CS/DS amount was significantly decreased in the differentiated (DI) group compared to the non-differentiated (ND) group, along with a lower expression of CS biosynthesis-related genes, chondroitin sulfate N-acetylgalactosaminyltransferase 1 and 2, as well as chondroitin polymerizing factor. GAGs in the DI group also showed lower Mw than those of ND. Furthermore, the A unit was the major CS/DS in both groups, with a proportionally higher CS-A in the DI group. This was consistent with the expression of carbohydrate sulfotransferase 12 that encodes chondroitin 4-O-sulfotransferase, for CS-A formation. These qualitative and quantitative changes in CS/DS and CS/DS-synthases before and after adipocyte differentiation reveal valuable insights into adipocyte development.
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Affiliation(s)
- Danang Dwi Cahyadi
- Joint Graduate School of Veterinary Sciences, Tottori University, Tottori, Japan
- Division of Anatomy Histology and Embryology, School of Veterinary Medicine and Biomedical Sciences, IPB University, Bogor, Indonesia
| | - Katsuhiko Warita
- Joint Graduate School of Veterinary Sciences, Tottori University, Tottori, Japan
- Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Naoko Takeda-Okuda
- Department of Life and Environmental Agricultural Sciences, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Jun-Ichi Tamura
- Department of Life and Environmental Agricultural Sciences, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Yoshinao Z Hosaka
- Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan
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Pessentheiner AR, Ducasa GM, Gordts PLSM. Proteoglycans in Obesity-Associated Metabolic Dysfunction and Meta-Inflammation. Front Immunol 2020; 11:769. [PMID: 32508807 PMCID: PMC7248225 DOI: 10.3389/fimmu.2020.00769] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/06/2020] [Indexed: 12/16/2022] Open
Abstract
Proteoglycans are a specific subset of glycoproteins found at the cell surface and in the extracellular matrix, where they interact with a plethora of proteins involved in metabolic homeostasis and meta-inflammation. Over the last decade, new insights have emerged on the mechanism and biological significance of these interactions in the context of diet-induced disorders such as obesity and type-2 diabetes. Complications of energy metabolism drive most diet-induced metabolic disorders, which results in low-grade chronic inflammation, thereby affecting proper function of many vital organs involved in energy homeostasis, such as the brain, liver, kidney, heart and adipose tissue. Here, we discuss how heparan, chondroitin and keratan sulfate proteoglycans modulate obesity-induced metabolic dysfunction and low-grade inflammation that impact the initiation and progression of obesity-associated morbidities.
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Affiliation(s)
- Ariane R. Pessentheiner
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA, United States
| | - G. Michelle Ducasa
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA, United States
| | - Philip L. S. M. Gordts
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA, United States
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA, United States
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Anti-obesity effects of chondroitin sulfate oligosaccharides from the skate Raja pulchra. Carbohydr Polym 2019; 214:303-310. [DOI: 10.1016/j.carbpol.2019.03.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/11/2019] [Accepted: 03/08/2019] [Indexed: 12/27/2022]
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A comparison of methods for effective differentiation of the frozen-thawed 3T3-L1 cells. Anal Biochem 2018; 568:57-64. [PMID: 30594506 DOI: 10.1016/j.ab.2018.12.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/05/2018] [Accepted: 12/26/2018] [Indexed: 12/20/2022]
Abstract
The differentiation efficiency of 3T3-L1 preadipocytes is an essential factor affecting studies on cellular mechanisms associated with obesity, diabetes, and related disorders. Differentiation of 3T3-L1 cells is commonly induced by an adipogenic cocktail containing insulin, dexamethasone (DEX), and 3-isobutyl-1-methylxanthine (IBMX). However, 3T3-L1 cells after freezing and thawing for many times always have a low differentiation efficiency. To solve this problem, we compared the differentiation efficiency of six commonly used adipogenic cocktails and protocols published in 2017. On this basis, we further compared 18 adipogenic cocktails with 2 μM rosiglitazone added and/or with a prolonged treatment with IBMX. The results revealed that the adipogenic cocktail containing 0.5 mM IBMX, 1 μM DEX, and 10 μg/mL insulin was the most effective for the frozen-thawed 3T3-L1 cells differentiation. Rosiglitazone, and IBMX under a prolonged treatment, could improve the differentiation efficiency of the frozen-thawed 3T3-L1 cells. However, the effect was closely related to concentrations of agents in the adipogenic cocktails.
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Pyrintegrin Induces Soft Tissue Formation by Transplanted or Endogenous Cells. Sci Rep 2017; 7:36402. [PMID: 28128224 PMCID: PMC5269584 DOI: 10.1038/srep36402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 09/16/2016] [Indexed: 12/11/2022] Open
Abstract
Focal adipose deficiency, such as lipoatrophy, lumpectomy or facial trauma, is a formidable challenge in reconstructive medicine, and yet scarcely investigated in experimental studies. Here, we report that Pyrintegrin (Ptn), a 2,4-disubstituted pyrimidine known to promote embryonic stem cells survival, is robustly adipogenic and induces postnatal adipose tissue formation in vivo of transplanted adipose stem/progenitor cells (ASCs) and recruited endogenous cells. In vitro, Ptn stimulated human adipose tissue derived ASCs to differentiate into lipid-laden adipocytes by upregulating peroxisome proliferator-activated receptor (PPARγ) and CCAAT/enhancer-binding protein-α (C/EBPα), with differentiated cells increasingly secreting adiponectin, leptin, glycerol and total triglycerides. Ptn-primed human ASCs seeded in 3D-bioprinted biomaterial scaffolds yielded newly formed adipose tissue that expressed human PPARγ, when transplanted into the dorsum of athymic mice. Remarkably, Ptn-adsorbed 3D scaffolds implanted in the inguinal fat pad had enhanced adipose tissue formation, suggesting Ptn’s ability to induce in situ adipogenesis of endogenous cells. Ptn promoted adipogenesis by upregulating PPARγ and C/EBPα not only in adipogenesis induction medium, but also in chemically defined medium specifically for osteogenesis, and concurrently attenuated Runx2 and Osx via BMP-mediated SMAD1/5 phosphorylation. These findings suggest Ptn’s novel role as an adipogenesis inducer with a therapeutic potential in soft tissue reconstruction and augmentation.
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Ali D, Hamam R, Alfayez M, Kassem M, Aldahmash A, Alajez NM. Epigenetic Library Screen Identifies Abexinostat as Novel Regulator of Adipocytic and Osteoblastic Differentiation of Human Skeletal (Mesenchymal) Stem Cells. Stem Cells Transl Med 2016; 5:1036-47. [PMID: 27194745 DOI: 10.5966/sctm.2015-0331] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 03/10/2016] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED : The epigenetic mechanisms promoting lineage-specific commitment of human skeletal (mesenchymal or stromal) stem cells (hMSCs) into adipocytes or osteoblasts are still not fully understood. Herein, we performed an epigenetic library functional screen and identified several novel compounds, including abexinostat, which promoted adipocytic and osteoblastic differentiation of hMSCs. Using gene expression microarrays, chromatin immunoprecipitation for H3K9Ac combined with high-throughput DNA sequencing (ChIP-seq), and bioinformatics, we identified several key genes involved in regulating stem cell proliferation and differentiation that were targeted by abexinostat. Concordantly, ChIP-quantitative polymerase chain reaction revealed marked increase in H3K9Ac epigenetic mark on the promoter region of AdipoQ, FABP4, PPARγ, KLF15, CEBPA, SP7, and ALPL in abexinostat-treated hMSCs. Pharmacological inhibition of focal adhesion kinase (PF-573228) or insulin-like growth factor-1R/insulin receptor (NVP-AEW51) signaling exhibited significant inhibition of abexinostat-mediated adipocytic differentiation, whereas inhibition of WNT (XAV939) or transforming growth factor-β (SB505124) signaling abrogated abexinostat-mediated osteogenic differentiation of hMSCs. Our findings provide insight into the understanding of the relationship between the epigenetic effect of histone deacetylase inhibitors, transcription factors, and differentiation pathways governing adipocyte and osteoblast differentiation. Manipulating such pathways allows a novel use for epigenetic compounds in hMSC-based therapies and tissue engineering. SIGNIFICANCE This unbiased epigenetic library functional screen identified several novel compounds, including abexinostat, that promoted adipocytic and osteoblastic differentiation of human skeletal (mesenchymal or stromal) stem cells (hMSCs). These data provide new insight into the understanding of the relationship between the epigenetic effect of histone deacetylase inhibitors, transcription factors, and differentiation pathways controlling adipocyte and osteoblast differentiation of hMSCs. Manipulating such pathways allows a novel use for epigenetic compounds in hMSC-based therapies for tissue engineering, bone disease, obesity, and metabolic-disorders.
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Affiliation(s)
- Dalia Ali
- Stem Cell Unit, Department of Anatomy, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Rimi Hamam
- Stem Cell Unit, Department of Anatomy, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Musaed Alfayez
- Stem Cell Unit, Department of Anatomy, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Moustapha Kassem
- Stem Cell Unit, Department of Anatomy, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia Molecular Endocrinology and Stem Cell Research Unit, Department of Endocrinology, University of Southern Denmark, Odense, Denmark
| | - Abdullah Aldahmash
- Stem Cell Unit, Department of Anatomy, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia Prince Naif Health Research Center, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Nehad M Alajez
- Stem Cell Unit, Department of Anatomy, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
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Enzymatic fragments of hyaluronan inhibit adipocyte differentiation in 3T3-L1 pre-adipocytes. Biochem Biophys Res Commun 2015; 467:623-8. [PMID: 26525853 DOI: 10.1016/j.bbrc.2015.10.104] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 10/20/2015] [Indexed: 11/21/2022]
Abstract
Hyaluronan has diverse biological activities depending on its molecular size. High molecular weight hyaluronan (2000 kDa) is a major component of extracellular matrix, and has been used in wounding healing, extracellular matrix regeneration, and in the treatment of osteoarthritis. Hyaluronan fragments can stimulate inflammation or induce loss of extracellular matrix. Hyaluronan is expressed during adipocyte differentiation, and down regulation of hyaluronan synthesis can reduce adipogenic differentiation. However, the direct effects of hyaluronan fragments on adipocyte differentiation have not been elucidated. Therefore, we prepared hyaluronan fragments by enzymatic digestion, and examined the inhibitory effects of these hyaluronan fragments on the accumulation of lipid droplets and on adipogenic gene mRNA expression in differentiating 3T3-L1 pre-adipocytes. Medium sized hyaluronan fragments (50 kDa) decreased lipid droplet accumulation in a dose-dependent manner. However, high molecular weight hyaluronan did not inhibit lipid droplet accumulation when used at a concentration of 600 μg/ml. Two or 4 day treatments with medium molecular weight of hyaluronan resulted in similar inhibitory levels of lipid accumulation as did treatment for 8 days. Medium sized hyaluronan inhibited the differentiation of 3T3-L1 pre-adipocytes during the early stages of adipogenesis. When 3T3-L1 cells were treated with 180 μg/ml of medium sized hyaluronan, the mRNAs for the master adipogenic transcription factors PPAR-γ and C/EBP-α were inhibited. Additionally, medium molecular weight hyaluronan suppressed mRNA expression of PPAR-γ target genes, including aP2 and FAS. This study is the first to report that medium molecular weight hyaluronan fragments can inhibit adipocyte differentiation.
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Limoge F, Faivre L, Gautier T, Petit JM, Gautier E, Masson D, Jego G, El Chehadeh-Djebbar S, Marle N, Carmignac V, Deckert V, Brindisi MC, Edery P, Ghoumid J, Blair E, Lagrost L, Thauvin-Robinet C, Duplomb L. Insulin response dysregulation explains abnormal fat storage and increased risk of diabetes mellitus type 2 in Cohen Syndrome. Hum Mol Genet 2015; 24:6603-13. [PMID: 26358774 DOI: 10.1093/hmg/ddv366] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 09/03/2015] [Indexed: 12/24/2022] Open
Abstract
Cohen Syndrome (CS) is a rare autosomal recessive disorder, with defective glycosylation secondary to mutations in the VPS13B gene, which encodes a protein of the Golgi apparatus. Besides congenital neutropenia, retinopathy and intellectual deficiency, CS patients are faced with truncal obesity. Metabolism investigations showed abnormal glucose tolerance tests and low HDL values in some patients, and these could be risk factors for the development of diabetes mellitus and/or cardiovascular complications. To understand the mechanisms involved in CS fat storage, we used two models of adipogenesis differentiation: (i) SGBS pre-adipocytes with VPS13B invalidation thanks to siRNA delivery and (ii) CS primary fibroblasts. In both models, VPS13B invalidation led to accelerated differentiation into fat cells, which was confirmed by the earlier and increased expression of specific adipogenic genes, consequent to the increased response of cells to insulin stimulation. At the end of the differentiation protocol, these fat cells exhibited decreased AKT2 phosphorylation after insulin stimulation, which suggests insulin resistance. This study, in association with the in-depth analysis of the metabolic status of the patients, thus allowed us to recommend appropriate nutritional education to prevent the occurrence of diabetes mellitus and to put forward recommendations for the follow-up of CS patients, in particular with regard to the development of metabolic syndrome. We also suggest replacing the term obesity by abnormal fat distribution in CS, which should reduce the number of inappropriate diagnoses in patients who are referred only on the basis of intellectual deficiency associated with obesity.
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Affiliation(s)
- Floriane Limoge
- Génétique des Anomalies du Développement GAD EA4271, Univeristé de Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Laurence Faivre
- Génétique des Anomalies du Développement GAD EA4271, Univeristé de Bourgogne Franche-Comté, F-21000 Dijon, France, FHU TRANSLAD, Département de Génétique, Hôpital d'enfants, CHU Dijon, F-21000 Dijon, France
| | - Thomas Gautier
- LNC UMR866, INSERM, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | | | - Elodie Gautier
- Génétique des Anomalies du Développement GAD EA4271, Univeristé de Bourgogne Franche-Comté, F-21000 Dijon, France, FHU TRANSLAD, Département de Génétique, Hôpital d'enfants, CHU Dijon, F-21000 Dijon, France
| | - David Masson
- LNC UMR866, INSERM, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Gaëtan Jego
- LNC UMR866, INSERM, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Salima El Chehadeh-Djebbar
- Génétique des Anomalies du Développement GAD EA4271, Univeristé de Bourgogne Franche-Comté, F-21000 Dijon, France, FHU TRANSLAD, Département de Génétique, Hôpital d'enfants, CHU Dijon, F-21000 Dijon, France
| | - Nathalie Marle
- Génétique des Anomalies du Développement GAD EA4271, Univeristé de Bourgogne Franche-Comté, F-21000 Dijon, France, FHU TRANSLAD, Département de Génétique, Hôpital d'enfants, CHU Dijon, F-21000 Dijon, France
| | - Virginie Carmignac
- Génétique des Anomalies du Développement GAD EA4271, Univeristé de Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Valérie Deckert
- LNC UMR866, INSERM, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | | | - Patrick Edery
- Service de Génétique Clinique, Hôpital Femme Mère Enfant, CHU Lyon, HCL, Lyon, France
| | - Jamal Ghoumid
- Centre de Référence Maladies Rares Anomalies du Développement et Syndromes Malformatifs Nord, Hôpital Jeanne de Flandres, CHRU Lille, Lille, France and
| | - Edward Blair
- Department of Clinical Genetics, Oxford Regional Genetics Service, The Churchill Hospital, Oxford, UK
| | - Laurent Lagrost
- LNC UMR866, INSERM, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Christel Thauvin-Robinet
- Génétique des Anomalies du Développement GAD EA4271, Univeristé de Bourgogne Franche-Comté, F-21000 Dijon, France, FHU TRANSLAD, Département de Génétique, Hôpital d'enfants, CHU Dijon, F-21000 Dijon, France
| | - Laurence Duplomb
- Génétique des Anomalies du Développement GAD EA4271, Univeristé de Bourgogne Franche-Comté, F-21000 Dijon, France, FHU TRANSLAD, Département de Génétique, Hôpital d'enfants, CHU Dijon, F-21000 Dijon, France,
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Cheung HK, Han TTY, Marecak DM, Watkins JF, Amsden BG, Flynn LE. Composite hydrogel scaffolds incorporating decellularized adipose tissue for soft tissue engineering with adipose-derived stem cells. Biomaterials 2013; 35:1914-23. [PMID: 24331712 DOI: 10.1016/j.biomaterials.2013.11.067] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 11/21/2013] [Indexed: 12/18/2022]
Abstract
An injectable tissue-engineered adipose substitute that could be used to deliver adipose-derived stem cells (ASCs), filling irregular defects and stimulating natural soft tissue regeneration, would have significant value in plastic and reconstructive surgery. With this focus, the primary aim of the current study was to characterize the response of human ASCs encapsulated within three-dimensional bioscaffolds incorporating decellularized adipose tissue (DAT) as a bioactive matrix within photo-cross-linkable methacrylated glycol chitosan (MGC) or methacrylated chondroitin sulphate (MCS) delivery vehicles. Stable MGC- and MCS-based composite scaffolds were fabricated containing up to 5 wt% cryomilled DAT through initiation with long-wavelength ultraviolet light. The encapsulation strategy allows for tuning of the 3-D microenvironment and provides an effective method of cell delivery with high seeding efficiency and uniformity, which could be adapted as a minimally-invasive in situ approach. Through in vitro cell culture studies, human ASCs were assessed over 14 days in terms of viability, glycerol-3-phosphate dehydrogenase (GPDH) enzyme activity, adipogenic gene expression and intracellular lipid accumulation. In all of the composites, the DAT functioned as a cell-supportive matrix that enhanced ASC viability, retention and adipogenesis within the gels. The choice of hydrogel also influenced the cell response, with significantly higher viability and adipogenic differentiation observed in the MCS composites containing 5 wt% DAT. In vivo analysis in a subcutaneous Wistar rat model at 1, 4 and 12 weeks showed superior implant integration and adipogenesis in the MCS-based composites, with allogenic ASCs promoting cell infiltration, angiogenesis and ultimately, fat formation.
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Affiliation(s)
- Hoi Ki Cheung
- Department of Chemical Engineering, Queen's University, 19 Division Street, Kingston, Ontario, Canada K7L 3N6; Human Mobility Research Centre, Kingston General Hospital, 76 Stuart Street, Kingston, Ontario, Canada K7L 2V7
| | - Tim Tian Y Han
- Department of Chemical Engineering, Queen's University, 19 Division Street, Kingston, Ontario, Canada K7L 3N6; Human Mobility Research Centre, Kingston General Hospital, 76 Stuart Street, Kingston, Ontario, Canada K7L 2V7
| | - Dale M Marecak
- Department of Chemical Engineering, Queen's University, 19 Division Street, Kingston, Ontario, Canada K7L 3N6; Human Mobility Research Centre, Kingston General Hospital, 76 Stuart Street, Kingston, Ontario, Canada K7L 2V7
| | - John F Watkins
- Department of Surgery, Queen's University, 166 Brock Street, Kingston, Ontario, Canada K7L 5G2
| | - Brian G Amsden
- Department of Chemical Engineering, Queen's University, 19 Division Street, Kingston, Ontario, Canada K7L 3N6; Human Mobility Research Centre, Kingston General Hospital, 76 Stuart Street, Kingston, Ontario, Canada K7L 2V7
| | - Lauren E Flynn
- Department of Chemical Engineering, Queen's University, 19 Division Street, Kingston, Ontario, Canada K7L 3N6; Human Mobility Research Centre, Kingston General Hospital, 76 Stuart Street, Kingston, Ontario, Canada K7L 2V7; Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart Street, Kingston, Ontario, Canada K7L 3N6.
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Tasdelen I, Berger R, Kalkhoven E. PPARγ regulates expression of carbohydrate sulfotransferase 11 (CHST11/C4ST1), a regulator of LPL cell surface binding. PLoS One 2013; 8:e64284. [PMID: 23696875 PMCID: PMC3655946 DOI: 10.1371/journal.pone.0064284] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 04/12/2013] [Indexed: 01/09/2023] Open
Abstract
The transcription factor PPARγ is the key regulator of adipocyte differentiation, function and maintenance, and the cellular target of the insulin-sensitizing thiazolidinediones. Identification and functional characterization of genes regulated by PPARγ will therefore lead to a better understanding of adipocyte biology and may also contribute to the development of new anti-diabetic drugs. Here, we report carbohydrate sulfotransferase 11 (Chst11/C4st1) as a novel PPARγ target gene. Chst11 can sulphate chondroitin, a major glycosaminoglycan involved in development and disease. The Chst11 gene contains two functional intronic PPARγ binding sites, and is up-regulated at the mRNA and protein level during 3T3-L1 adipogenesis. Chst11 knockdown reduced intracellular lipid accumulation in mature adipocytes, which is due to a lowered activity of lipoprotein lipase, which may associate with the adipocyte cell surface through Chst11-mediated sulfation of chondroitin, rather than impaired adipogenesis. Besides directly inducing Lpl expression, PPARγ may therefore control lipid accumulation by elevating the levels of Chst11-mediated proteoglycan sulfation and thereby increasing the binding capacity for Lpl on the adipocyte cell surface.
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Affiliation(s)
- Ismayil Tasdelen
- Department of Metabolic Diseases and The Netherlands Metabolomics Center, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Ruud Berger
- Department of Metabolic Diseases and The Netherlands Metabolomics Center, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Eric Kalkhoven
- Department of Metabolic Diseases and The Netherlands Metabolomics Center, University Medical Centre Utrecht, Utrecht, The Netherlands
- * E-mail:
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Abstract
Adp (adiponectin), an adipocyte-secreted hormone, exerts its effect via its specific receptors, AdipoR1 and AdipoR2 (adiponectin receptors 1 and 2), on insulin-sensitive cells in muscle, liver and adipose tissues, and plays an important role in lipid and glucose metabolisms. The study has investigated the effect of insulin on AdipoRs expression in muscle and fat cells. Differentiated fat [3T3-L1 (mouse adipocytes)], L6 (skeletal muscle) and vascular smooth muscle (PAC1) cells were serum starved and exposed to 100 nM insulin for 1-24 h. AdipoR1 and AdipoR2 mRNAs expression was monitored by real-time PCR. The results demonstrate that insulin down-regulates both AdipoR1 and AdipoR2 mRNAs levels in a biphasic manner in L6 and PAC1 cells. Insulin had little or no effect in the regulation of AdipoR1 expression in 3T3-L1 cells, but significantly up-regulated AdipoR2 mRNA level in a biphasic manner. The fact that insulin differentially regulates the expression of AdipoR1 and AdipoR2 in muscle and fat cells suggests this is also dependent on the availability of the endogenous ligand, such as Adp for AdipoR1 and AdipoR2 in fat cells. The effects of globular Adp were also tested on insulin-regulated expression of AdipoRs in L6 cells, and found to up-regulate and counter insulin-mediated suppression of AdipoRs expression in L6 cells.
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Tang T, Thompson JC, Wilson PG, Nelson C, Williams KJ, Tannock LR. Decreased body fat, elevated plasma transforming growth factor-β levels, and impaired BMP4-like signaling in biglycan-deficient mice. Connect Tissue Res 2013; 54:5-13. [PMID: 22834985 PMCID: PMC4557867 DOI: 10.3109/03008207.2012.715700] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Biglycan (BGN), a small leucine-rich proteoglycan, binds the pro-fibrotic cytokine transforming growth factor β (TGFβ) and inhibits its bioactivity in vitro. Nevertheless, it is controversial whether BGN plays an inhibitory role in vivo. Therefore, the purpose of this study was to evaluate the effect of BGN deficiency on TGFβ activity in vivo by studying 1-year-old Bgn null and wild-type (WT) mice on an Ldlr-null background. Phenotypic and metabolic characterization showed that the Bgn null mice had lower body weight, shorter body length, and shorter femur length (all p < 0.05). Surprisingly, the Bgn null mice also exhibited a striking reduction in percent body fat compared to WT mice (p == 0.006), but no changes were observed in plasma triglycerides, total cholesterol, or glycohemoglobin. Both total and bioactive TGFβ1 concentrations in plasma were markedly elevated in Bgn null mice compared to WT mice (4-fold and 11-fold increase, respectively, both p < 0.001), but no changes were found in hepatic levels of mRNA for Tgfβ1 or its receptors. Bgn null mice exhibited elevated expression of hepatic fibronectin protein (p = 0.034) without changes in hepatic or renal histology, and Bgn null mice had decreased urinary albumin/creatinine ratio (p = 0.01). Two key downstream targets of bone morphogenetic protein 4-like signaling, SMAD1/3/5 phosphorylation and Id2 gene expression, were found dramatically reduced in Bgn null livers (p = 0.034). Thus, BGN deficiency decreases body fat in this hyperlipidemic mouse model without changing liver or kidney histology. Overall, we propose that this unexpected phenotype arises from the effects of BGN deficiency in vivo to elevate TGFβ levels while decreasing bone morphogenetic protein 4-like signaling.
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Affiliation(s)
- Tao Tang
- Division of Endocrinology and Molecular Medicine, Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Joel C. Thompson
- Division of Endocrinology and Molecular Medicine, Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Patricia G. Wilson
- Division of Endocrinology and Molecular Medicine, Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Christina Nelson
- Division of Endocrinology and Molecular Medicine, Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Kevin Jon Williams
- Department of Medicine, Section of Endocrinology, Diabetes and Metabolism, Temple University, Philadelphia, PA, USA
| | - Lisa R. Tannock
- Division of Endocrinology and Molecular Medicine, Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA, Department of Veterans Affairs, Lexington, KY, USA,Correspondence to: Dr. Lisa R. Tannock, Associate Professor of Medicine, Chief, Division of Endocrinology and Molecular Medicine, Room 567, Wethington Building, 900 S. Limestone, University of Kentucky, Lexington, KY 40536-0200, Tel: 859-323-4933 ext 81415, Fax: 859-257-3646,
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14
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Sattar AA, Sattar R. Globular adiponectin activates Akt in cultured myocytes. Biochem Biophys Res Commun 2012; 424:753-7. [PMID: 22809512 DOI: 10.1016/j.bbrc.2012.07.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 07/07/2012] [Indexed: 12/23/2022]
Abstract
The serine/threonine kinase Akt plays an important role in insulin-mediated glucose uptake. Adiponectin (Adp) is known to sensitize this process. The purpose of the current study is to investigate if Adp activates Akt independently from insulin; and if Adp synergizes with insulin on Akt phosphorylation in the rat skeletal muscle L6 cells. Differentiated L6 cells were serum-starved and exposed to various concentrations (0-100nM) of recombinant globular Adp (gAdp) and/or insulin for different time periods at 37°C. Phosphorylation of Akt was monitored by Western blot using an antiserum against pSer(473) or pThr(308) Akt. The results demonstrate that gAdp activates Akt in dose- and time-dependent manners. When L6 cells were treated with sub-maximal concentrations of both insulin (10nM) and gAdp (10nM) for 10 min neither synergistic nor additive activation of Akt was observed. Similar non-synergistic or non-additive effect of gAdp on insulin-induced Akt activation was also observed in mouse C2C12 myocytes and rat vascular smooth muscle PAC cells. Moreover, pretreatment of the L6 cells with wortmannin (100nM) for 20 min significantly reduced gAdp (100nM) induced and insulin (100nM) induced Akt activation by ∼80 and ∼70%, respectively. These data suggest that adiponectin stimulates Akt activation via the wortmannin sensitive pathway in L6 cells; and that its effects on Akt phosphorylation are not additive to those of insulin.
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Affiliation(s)
- Akm A Sattar
- Division of Endocrinology, Department of Internal Medicine, Wayne State University School of Medicine, Detroit, MI 48201-1928, USA.
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15
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Choi CW, Cho WM, Yeon SH, HwangBo S, Song MK, Park SK, Baek KH. Comparison between Single and Co-culture of Adipocyte and Muscle Cell Lines in Cell Morphology and Cytosolic Substances. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2012. [DOI: 10.5187/jast.2012.54.2.103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Angstmann M, Brinkmann I, Bieback K, Breitkreutz D, Maercker C. Monitoring human mesenchymal stromal cell differentiation by electrochemical impedance sensing. Cytotherapy 2011; 13:1074-89. [PMID: 21619493 DOI: 10.3109/14653249.2011.584863] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND AIMS For their wide mesodermal differentiation potential, mesenchymal stromal/stem cells (MSC) are attractive candidates for tissue engineering. However, standardized quality control assays monitoring differentiation that are non-invasive and continuous over time are lacking. METHODS We employed a non-invasive assay, using two different systems, to discriminate osteogenic and adipogenic differentiation of MSC by monitoring impedance. Fibroblasts and keratinocytes served as non-specific controls. Impedance profiles were recorded comparing MSC from bone marrow and adipose tissue, either non-induced or induced for osteogenesis or adipogenesis, for 5-14 days, and correlated with differentiation markers assessed by reverse transcription-quantitative polymerase chain reaction and Western blot. Additionally, differentiation modulating effects of extracellular matrix components were analyzed. RESULTS Adhesion and growth-related impedance profiles of non-induced MSC roughly resembled those of fibroblasts, whereas keratinocytes differed significantly. Distinct from that, osteogenic induction of MSC revealed initially rapid and continuously rising impedance, corresponding to mineralized calcium matrix formation. Conversely, adipogenic induction caused shallower initial slopes and eventually declining profiles, corresponding to more compact, adipocyte-like cells with numerous lipid vacuoles. Pre-coating with either collagen type I or IV apparently favored osteogenesis and fibronectin adipogenesis. Impedance recordings correlated well with the extent of differentiation evaluated by histochemical staining and protein and gene expression. CONCLUSIONS Overall, our data demonstrate that impedance profiling offers a basis for standardized real-time, non-invasive high-throughput screening of MSC properties. It enables further testing of the influence of diffusible factors or extracellular matrix composites on MSC differentiation or maintenance of stemness, thus substantiating therapeutic application.
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Affiliation(s)
- Michael Angstmann
- Mannheim University of Applied Sciences, Biotechnology, Mannheim, Germany
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17
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Mosna F, Sensebé L, Krampera M. Human Bone Marrow and Adipose Tissue Mesenchymal Stem Cells: A User's Guide. Stem Cells Dev 2010; 19:1449-70. [DOI: 10.1089/scd.2010.0140] [Citation(s) in RCA: 254] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Federico Mosna
- Stem Cell Research Laboratory, Section of Hematology, Department of Medicine, Policlinico “G.B. Rossi”—University of Verona, Verona, Italy
| | - Luc Sensebé
- Etablissement Français du Sang (EFS), Centre-Atlantique and EA3855 University François Rabelais, Tours, France
| | - Mauro Krampera
- Stem Cell Research Laboratory, Section of Hematology, Department of Medicine, Policlinico “G.B. Rossi”—University of Verona, Verona, Italy
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18
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Voros G, Sandy JD, Collen D, Lijnen HR. Expression of aggrecan(ases) during murine preadipocyte differentiation and adipose tissue development. Biochim Biophys Acta Gen Subj 2006; 1760:1837-44. [PMID: 17011710 DOI: 10.1016/j.bbagen.2006.08.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 08/08/2006] [Accepted: 08/08/2006] [Indexed: 11/27/2022]
Abstract
The expression and potential functional role of aggrecan in adipogenesis and adipose tissue development was investigated in murine models of obesity. Aggrecan, as well as the two aggrecanases ADAMTS-4 and ADAMTS-5 (A Disintegrin And Metalloproteinase with Thrombospondin motif) mRNAs, are expressed in subcutaneous (SC) and gonadal (GON) adipose tissues of mice. Their presence was confirmed by western blotting using adipose tissue extracts. In mice with nutritionally induced obesity (high fat diet) as well as in lean controls, aggrecan mRNA expression was downregulated whereas ADAMTS-4 and ADAMTS-5 were upregulated with time. In mice with genetically determined obesity (ob/ob), ADAMTS-5 mRNA was upregulated in both SC and GON adipose tissues, as compared to wild-type (WT) mice (p<0.001). Enhanced aggrecanase expression levels in these tissues were associated with significantly elevated levels of G1-NITEGE, a degradation product of aggrecan. Thus, aggrecan levels were high at the early stages of adipose tissue development in mice, whereas its production decreased and its degradation increased during development of obesity. A functional role of aggrecan in promoting early stages of adipogenesis is supported by the findings that it stimulated the in vitro differentiation of 3T3-F442A preadipocytes and the de novo in vivo accumulation of fat in Matrigel plaques injected into WT mice. Proteoglycans in the extracellular matrix of adipose tissue, such as aggrecan, may contribute to the regulation of lipid uptake and obesity in mice.
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Affiliation(s)
- Gabor Voros
- Center for Molecular and Vascular Biology, KU Leuven, Campus Gasthuisberg, O&N, Herestraat 49, Leuven, Belgium
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19
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Ross JW, Smith TK, Krehbiel CR, Malayer JR, DeSilva U, Morgan JB, White FJ, Hersom MJ, Horn GW, Geisert RD. Effects of grazing program and subsequent finishing on gene expression in different adipose tissue depots in beef steers. J Anim Sci 2006; 83:1914-23. [PMID: 16024712 DOI: 10.2527/2005.8381914x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This experiment was conducted to examine the effects of grazing program and subsequent finishing on gene expression in adipose tissue from steers. Twenty Angus x Angus-Hereford steer calves (initial BW = 231 +/- 25 kg) were allotted randomly to one of two winter grazing treatments: 1) grazing winter wheat pasture to achieve a high rate of BW gain (HGW); or 2) grazing dormant tallgrass native range (NR). Steers in the NR treatment were provided 0.91 kg.steer(-1).d(-1) of a 41% CP (as-fed basis) cottonseed meal supplement. Following the grazing period, steers were assigned randomly to feedlot pens. Steers were fed to a common endpoint of 1.27 cm of backfat between the 12th and 13th rib. Four steers from each treatment were slaughtered at the end of the grazing period, and the remaining steers from each treatment (n = 6) were slaughtered at the predetermined compositional endpoint. Intramuscular and s.c. fat samples were collected from LM sections of each steer at the 12th-/13th-rib interface on the left side. Pools of RNA were prepared for HGW and NR s.c. adipose tissue from steers slaughtered immediately after grazing. Suppression subtractive hybridization was performed followed by dot-blot hybridization screening to confirm differential expression of subtracted transcripts. Transcripts confirmed to be differentially expressed were subjected to dideoxy chain-termination sequencing. Quantitative reverse transcription PCR was performed on three differentially expressed clones: osteonectin, ferritin heavy chain, and decorin. Osteonectin, ferritin heavy chain, and decorin gene expression was greater (P < 0.05) in s.c. than in i.m. adipose tissue of finished steers. A depot x background interaction for osteonectin (P < 0.01) and ferritin heavy chain (P = 0.03) gene expression was observed for steers slaughtered after grazing, indicating that nutritional management can affect gene expression in adipose tissue depots differently. No differences resulting from prefinishing nutritional background (HGW or NR) were noted in osteonectin, ferritin heavy chain, or decorin gene expression in i.m. adipose tissue collected from finished steers, which might have resulted from feeding steers to the same compositional endpoint. Our data suggest that nutritional background alters gene expression in adipose depots, and that depots are influenced differently.
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Affiliation(s)
- J W Ross
- Department of Animal Science, Oklahoma Agricultural Experiment Station, Oklahoma State University, Stillwater, 74078, USA
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20
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Fischbach C, Seufert J, Staiger H, Hacker M, Neubauer M, Göpferich A, Blunk T. Three-dimensional in vitro model of adipogenesis: comparison of culture conditions. ACTA ACUST UNITED AC 2004; 10:215-29. [PMID: 15009947 DOI: 10.1089/107632704322791862] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In vivo and in vitro studies have demonstrated both promise and current limitations in tissue engineering of fat. Herein, we report the establishment of a well-defined three-dimensional (3-D) in vitro model useful for systematic investigations of 3-D adipogenesis. Polyglycolic acid fiber meshes were dynamically seeded with 3T3-L1 preadipocytes; subsequently, cell-polymer constructs were hormonally induced and cultivation under three different conditions was evaluated. Regarding tissue coherence and intracellular lipid content, culture of cell-polymer constructs either dynamically in well plates or in stirred bioreactors yielded similar results, which were distinctly improved compared with static conditions in well plates. At the protein and mRNA levels, significantly increased expression of genes characteristic for a mature adipose phenotype was demonstrated for constructs dynamically cultured in well plates, as compared with static conditions. Furthermore, investigation of lipolysis under stimulating and inhibiting conditions demonstrated functionality of the dynamically differentiated constructs. Using dynamic culture conditions, the presented in vitro model system is suggested as a valuable tool serving both fat tissue engineering and basic research by facilitating investigations of tissue-inherent features not possible under conventional 2-D culture conditions.
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Affiliation(s)
- Claudia Fischbach
- Department of Pharmaceutical Technology, University of Regensburg, Regensburg, Germany
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21
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Tahara K, Aso H, Yamasaki T, Rose MT, Takasuga A, Sugimoto Y, Yamaguchi T, Tahara K, Takano S. Cloning and expression of type XII collagen isoforms during bovine adipogenesis. Differentiation 2004; 72:113-22. [PMID: 15157235 DOI: 10.1111/j.1432-0436.2004.07204006.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In order to isolate candidate genes involved in bovine adipocyte differentiation, we have constructed a subtraction library from a clonal bovine intra-muscular pre-adipocyte (BIP) cell line using the suppression subtractive hybridization method. We have isolated a set of subtracted cDNA fragments whose respective mRNA levels are up-regulated during the adipogenic differentiation of BIP cells, and cloned cDNAs from a differentiated BIP-lambda ZAP II cDNA library. Two cDNA clones were highly homologous to the sequence of mouse and human type XII collagen alpha-1, determined by a BLAST homology search. As type XII collagen has been reported to have four types of splicing isoform, two clones were determined to be XII-1 and XII-2 splicing isoforms, respectively, because of a difference in the C-terminal NC1 domain. From the expression analysis of type XII collagen, the XIIA-2 isoform was mainly expressed in differentiated BIP cells and adipose tissues. Although the function of type XII collagen has not been established as yet, these results suggest that type XII collagen may be associated with adipocyte differentiation and adipose formation in cattle and is a potentially useful marker for adipogenesis.
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Affiliation(s)
- Koji Tahara
- Cellular Biology Laboratory, Faculty of Agriculture, Tohoku University, Sendai, 981-8555, Japan.
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22
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Yoneda S, Shibata S, Yamashita Y, Yanagishita M. Biosynthesis of versican by rat dental pulp cells in culture. Arch Oral Biol 2002; 47:435-42. [PMID: 12102759 DOI: 10.1016/s0003-9969(02)00029-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The biosynthesis of proteoglycans by these cultured pulp cells was investigated by metabolic labelling, using [(35)S]sulphate, [(3)H]glucosamine and [(3)H]leucine as precursors. Versican-like large proteoglycan, decorin- and biglycan-like small proteoglycans and a small amount of sulphated protein were released into the culture medium. Heparan sulphate species were also identified in cell-layer extracts. Versican-like proteoglycan had an average molecular mass of approximately 800kDa. The molecular mass of chondroihnase ABC-digested core protein exhibited heterogeneity, ranging from 250 to 400kDa, and the glycosaminoglycan chains had an average molecular mass of approximately 42kDa. These results indicate the presence of 10-13 glycosaminoglycan chains per core protein, consistent with the characteristics of versican. This glycosaminoglycan chain contained approximately 63% 4-sulphated disaccharides.
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Affiliation(s)
- S Yoneda
- Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
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23
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Lange K. Role of microvillar cell surfaces in the regulation of glucose uptake and organization of energy metabolism. Am J Physiol Cell Physiol 2002; 282:C1-26. [PMID: 11742794 DOI: 10.1152/ajpcell.2002.282.1.c1] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Experimental evidence suggesting a type of glucose uptake regulation prevailing in resting and differentiated cells was surveyed. This type of regulation is characterized by transport-limited glucose metabolism and depends on segregation of glucose transporters on microvilli of differentiated or resting cells. Earlier studies on glucose transport regulation and a recently presented general concept of influx regulation for ions and metabolic substrates via microvillar structures provide the basic framework for this theory. According to this concept, glucose uptake via transporters on microvilli is regulated by changes in the structural organization of the microfilament bundle, which is acting as a diffusion barrier between the microvillar tip compartment and the cytoplasm. Both microvilli formation and the switch of glucose metabolism from "metabolic regulation" to "transport limitation" occur during differentiation. The formation of microvillar cell surfaces creates the essential preconditions to establish the characteristic functions of specialized tissue cells including the coordination between glycolysis and oxidative phosphorylation, regulation of cellular functions by external signals, and Ca(2+) signaling. The proposed concept integrates various aspects of glucose uptake regulation into a ubiquitous cellular mechanism involved in regulation of transmembrane ion and substrate fluxes.
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24
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Kubo Y, Kaidzu S, Nakajima I, Takenouchi K, Nakamura F. Organization of extracellular matrix components during differentiation of adipocytes in long-term culture. In Vitro Cell Dev Biol Anim 2000; 36:38-44. [PMID: 10691039 DOI: 10.1290/1071-2690(2000)036<0038:ooemcd>2.0.co;2] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Scanning electron microscopy (SEM) observation showed that fully differentiated spherical adipocytes were embraced by a network of collagens and fibroblastic preadipocytes. The properties of both the collagen networks and the preadipocytes allow the adipocytes to be interconnected, forming a fat-cell cluster, which can anchor to the bottom of a culture dish. In this network structure, collagen fibrils and fibrillar bundles were closely arranged and stratified. We found that immunostained collagens appeared to form extracellular network structures, which can be observed by SEM. The extracellular network of fibronectin was the first to develop among the extracellular matrix (ECM) components, though it became degraded with the progress of adipocyte differentiation. The type I collagen network was the last to develop and remained well organized through the late stage of adipocyte differentiation. The extracellular networks of type III, V, and VI collagen developed by the mid-stage and remained in the late stage of adipocyte differentiation. The network structures of type IV collagen and laminin became degraded during the differentiation process and localized at the surface of spherical cells. In addition to these basement membrane components, types III, V, and VI collagens also showed pericellular spherical staining patterns. These results demonstrated that the constitution and distribution of the ECM are altered during adipocyte differentiation, suggesting that the organization of each ECM component into a suitable structure is a requirement for the differentiation and maintenance of unilocular adipocytes.
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Affiliation(s)
- Y Kubo
- Research Group of Animal Product Science, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
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25
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Abstract
The adipocyte plays a critical role in energy balance. Adipose tissue growth involves an increase in adipocyte size and the formation of new adipocytes from precursor cells. For the last 20 years, the cellular and molecular mechanisms of adipocyte differentiation have been extensively studied using preadipocyte culture systems. Committed preadipocytes undergo growth arrest and subsequent terminal differentiation into adipocytes. This is accompanied by a dramatic increase in expression of adipocyte genes including adipocyte fatty acid binding protein and lipid-metabolizing enzymes. Characterization of regulatory regions of adipose-specific genes has led to the identification of the transcription factors peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and CCAAT/enhancer binding protein (C/EBP), which play a key role in the complex transcriptional cascade during adipocyte differentiation. Growth and differentiation of preadipocytes is controlled by communication between individual cells or between cells and the extracellular environment. Various hormones and growth factors that affect adipocyte differentiation in a positive or negative manner have been identified. In addition, components involved in cell-cell or cell-matrix interactions such as preadipocyte factor-1 and extracellular matrix proteins are also pivotal in regulating the differentiation process. Identification of these molecules has yielded clues to the biochemical pathways that ultimately result in transcriptional activation via PPAR-gamma and C/EBP. Studies on the regulation of the these transcription factors and the mode of action of various agents that influence adipocyte differentiation will reveal the physiological and pathophysiological mechanisms underlying adipose tissue development.
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Affiliation(s)
- F M Gregoire
- Department of Nutritional Sciences, University of California, Berkeley, USA
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26
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Smas CM, Green D, Sul HS. Structural characterization and alternate splicing of the gene encoding the preadipocyte EGF-like protein pref-1. Biochemistry 1994; 33:9257-65. [PMID: 7519443 DOI: 10.1021/bi00197a029] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Preadipocyte factor 1 (pref-1), a member of the EGF-like protein family, is a transmembrane protein with six tandem EGF-like repeats in the putative extracellular domain. Expression of pref-1 is abolished during the in vitro differentiation of 3T3-L1 preadipocytes to adipocytes, and constitutive expression of pref-1 in preadipocytes inhibits their differentiation [Smas, C.M., & Sul, H.S. (1993) Cell 73, 725-734]. In the present studies, we have isolated and characterized genomic clones for pref-1 and have identified multiple pref-1 transcripts generated by alternate splicing. The pref-1 gene consists of five exons and four introns spanning approximately 7.3 kb. By primer extension analysis, the transcription start site was determined to be 169 bp upstream from the translation initiation codon. We have identified functional promoter sequences by transient transfection using a 2.1 kb fragment of the pref-1 5' flanking region linked to a luciferase gene; the pref-1-luciferase fusion gene construct gave 20-fold higher promoter activity as compared to the promoterless vector. Analysis of exon-intron junctions reveals that unlike the majority of the mammalian EGF-like genes, EGF-like repeats of pref-1 are not encoded by discrete exons. Through RT-PCR and the isolation and analysis of multiple pref-1 cDNA clones, we have identified, in addition to full-length pref-1, five alternately spliced forms with various in-frame deletions of all or a part of the sixth EGF-like repeat, juxta-membrane, and predicted transmembrane domains.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C M Smas
- Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts 02115
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27
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Varzaneh FE, Shillabeer G, Wong KL, Lau DC. Extracellular matrix components secreted by microvascular endothelial cells stimulate preadipocyte differentiation in vitro. Metabolism 1994; 43:906-12. [PMID: 8028517 DOI: 10.1016/0026-0495(94)90275-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Paracrine interaction between preadipocytes and microvascular endothelial cells may play a role in the regulation of adipose tissue growth. We report here a study of the effect of extracellular matrix factors secreted by microvascular endothelial cells, derived from adipose tissue, on preadipocyte differentiation in primary culture. Extracellular matrix components (EC) were prepared by differential centrifugation of medium conditioned by microvascular endothelial cells (CM). Preadipocyte differentiation was assessed by enumerating cells containing Oil-Red-O-stainable neutral lipids and by assaying cellular triacylglycerol (TG) content and glycerol-3-phosphate dehydrogenase (GPDH) specific activity. Both supernatant (containing soluble components) and pelleted (containing large complexes of EC) fractions of CM stimulated preadipocyte differentiation. When the supernatant fraction was used, the proportion of cells containing visible lipid droplets was 29% +/- 3% of total preadipocytes in the presence of extracellular complexes, as compared with 6% +/- 1% under control conditions. This differentiation induction was associated with fourfold increases in TG content and GPDH specific activity. Neither the supernatant nor the pelleted fraction of EC affected the maximal differentiation induced by hormonal stimulation in serum-supplemented or serum-free media. The major EC, fibronectin, laminin, and collagen IV, had no effect on differentiation when added individually to culture medium. Collection of CM under hyperglycemic (18 mmol/L glucose) compared with control (6 mmol/L glucose) conditions reduced the stimulatory effect of extracellular complexes by twofold, suggesting decreased or altered production by endothelial cells. The present findings demonstrate that microvascular endothelial cells release EC that promote preadipocyte differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- F E Varzaneh
- Loeb Institute for Medical Research, Ottawa, Ontario, Canada
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28
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Abstract
Purification of a protein typically involves development of a quantitative assay to track protein integrity (e.g. enzyme activity) during subsequent isolation steps. The generalized procedure involves choosing the source of the protein, defining extraction conditions, developing bulk purification methods followed by refined, more selective methods. The purification of proteoglycans is often complicated by a) limited source quantities, b) necessity of chaotrophic solvents for efficient extraction, c) their large molecular size and d) lack of defined functions to enable purity (i.e. activity, conformation) to be assessed. Because the usual goal of proteoglycan purification is physical characterization (intact molecular weight, core protein and glycosaminoglycan class and size), the problems of a suitable assay and/or native conformation are avoided. The 'assay' for tracking proteoglycan isolation typically utilizes uronic acid content or radiolabel incorporation as a marker. Once extracted from their cellular/extracellular environment, proteoglycans can be isolated by density gradient centrifugation and/or column chromatography techniques. Recent advances in the composition of chromatographic supports have enabled the application of ion-exchange, gel permeation, hydrophobic interaction and affinity chromatography resins using efficient high-pressure liquid chromatography to proteoglycan purification.
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Affiliation(s)
- N S Fedarko
- Bone Research Branch, National Institute of Dental Reearch, National Institutes of Health, Bethesda, Maryland 20892
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29
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Abstract
Proteoglycans are glycosylated proteins which have covalently attached highly anionic glycosaminoglycans. Many forms of proteoglycans are present in virtually all extracellular matrices of connective tissues. The major biological function of proteoglycans derives from the physicochemical characteristics of the glycosaminoglycan component of the molecule, which provides hydration and swelling pressure to the tissue enabling it to withstand compressional forces. This function is best illustrated by the most abundant proteoglycan in cartilage tissues, aggrecan. During the past decade, diverse species of proteoglycans have been identified in many connective tissues, on cell surfaces and in intracellular compartments. These proteoglycans have distinct biological functions apart from their hydrodynamic functions, and their involvement in many aspects of cell and tissue activities has been demonstrated. For example, decorin, which is widely distributed in many connective tissues, may have functions in regulating collagen fibril formation and in modifying the activity of transforming growth factor-beta; perlecan, the major heparan sulfate proteoglycan in the glomerular basement membrane, may play an important role as the major anionic site responsible for the charge selectivity in glomerular filtration. Specific interactions between proteoglycans (through both their glycosaminoglycan and core protein components) and macromolecules in the extracellular matrix are the key factors in the functions of proteoglycans. Exciting biological functions of proteoglycans are now gradually emerging.
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Affiliation(s)
- M Yanagishita
- Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892
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30
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Abstract
With the aim of identifying novel regulators of adipocyte differentiation, we have cloned and characterized preadipocyte factor 1 (pref-1), a novel member of the epidermal growth factor (EGF)-like family of proteins. Pref-1 is synthesized as a transmembrane protein with six tandem EGF-like repeats. In preadipocytes, multiple discrete forms of pref-1 protein of 45-60 kd are present, owing in part to N-linked glycosylation. While pref-1 mRNA is abundant in preadipocytes, its expression is completely abolished during differentiation of 3T3-L1 preadipocytes to adipocytes. Moreover, constitutive expression of pref-1 in preadipocytes, which in effect blocks its down-regulation, drastically inhibits adipose differentiation. This indicates that pref-1 functions as a negative regulator of adipocyte differentiation, possibly in a manner analogous to EGF-like proteins that govern cell fate decisions in invertebrates.
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Affiliation(s)
- C M Smas
- Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts 02115
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31
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Abstract
Purification of a protein typically involves development of a quantitative assay to track protein integrity (e.g. enzyme activity) during subsequent isolation steps. The generalized procedure involves choosing the source of the protein, defining extraction conditions, developing bulk purification methods followed by refined, more selective methods. The purification of proteoglycans is often complicated by a) limited source quantities, b) necessity of chaotropic solvents for efficient extraction, c) their large molecular size and d) lack of defined functions to enable purity (i.e. activity, conformation) to be assessed. Because the usual goal of proteoglycan purification is physical characterization (intact molecular weight, core protein and glycosaminoglycan class and size), the problems of a suitable assay and/or native conformation are avoided. The 'assay' for tracking proteoglycan isolation typically utilizes uronic acid content or radiolabel incorporation as a marker. Once extracted from their cellular/extracellular environment, proteoglycans can be isolated by density gradient centrifugation and/or column chromatography techniques. Recent advances in the composition of chromatographic supports have enabled the application of ion-exchange, gel permeation, hydrophobic interaction and affinity chromatography resins using efficient high-pressure liquid chromatography to proteoglycan purification.
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Affiliation(s)
- N S Fedarko
- Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892
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32
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Abstract
The effect of progesterone on the differentiation of the 3T3-L1 preadipocytes was investigated and compared with other sex steroids (estradiol and testosterone), with cortisol, with the synthetic progestin R5020 and with the progestin/glucocorticoid antagonist RU38486. At 10(-8) M, progesterone stimulated the activity of glycerol-3-phosphate dehydrogenase and triglyceride deposition. Progesterone, R5020, cortisol, and RU38486 increased triglycerides about 2-fold at 10(-7) M. Only minimal effects were observed with testosterone and estradiol even at 10(-6) M. When the cells were cultured in presence of 10(-5) M metyrapone the effect of progesterone was unchanged, suggesting that the progesterone was not metabolized to a glucocorticoid. Progesterone, R5020 and RU38486 competed efficiently with [3H]dexamethasone for the glucocorticoid receptor in 3T3-L1 cytosol. These results indicate a significant, reproducible dose-dependent effect of progestins on differentiation of the preadipocytes, which appears to be mediated via the glucocorticoid receptor.
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Affiliation(s)
- C M Rondinone
- Laboratory of Theoretical and Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health 20892
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