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Bose GS, Kalakoti G, Kulkarni AP, Mittal S. AP-1/C-FOS and AP-1/FRA2 differentially regulate early and late adipogenic differentiation of mesenchymal stem cells. J Cell Biochem 2024. [PMID: 38440920 DOI: 10.1002/jcb.30543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 02/01/2024] [Accepted: 02/15/2024] [Indexed: 03/06/2024]
Abstract
Obesity is defined as an abnormal accumulation of adipose tissue in the body and is a major global health problem due to increased morbidity and mortality. Adipose tissue is made up of adipocytes, which are fat-storing cells, and the differentiation of these fat cells is known as adipogenesis. Several transcription factors (TFs) such as CEBPβ, CEBPα, PPARγ, GATA, and KLF have been reported to play a key role in adipogenesis. In this study, we report one more TF AP-1, which is found to be involved in adipogenesis. Human mesenchymal stem cells were differentiated into adipocytes, and the expression pattern of different subunits of AP-1 was examined during adipogenesis. It was observed that C-FOS was predominantly expressed at an early stage (Day 2), whereas FRA2 expression peaked at later stages (Days 6 and 8) of adipogenesis. Chromatin immunoprecipitation-sequencing analysis revealed that C-FOS binds mainly to the promoters of WNT1, miR-30a, and ANAPC7 and regulates their expression during mitotic clonal expansion. In contrast, FRA2 binds to the promoters of CIDEA, NOTCH1, ARAF, and MYLK, regulating their expression and lipid metabolism. Data obtained clearly indicate that the differential expression of C-FOS and FRA2 is crucial for different stages of adipogenesis. This also raises the possibility of considering AP-1 as a therapeutic target for treating obesity and related disorders.
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Affiliation(s)
- Ganesh Suraj Bose
- Department of Biotechnology, Savitribai Phule Pune University, Pune, India
| | - Garima Kalakoti
- Bioinformatics Center, Savitribai Phule Pune University, Pune, India
| | | | - Smriti Mittal
- Department of Biotechnology, Savitribai Phule Pune University, Pune, India
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2
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Ruhl T, Nuptybayeva A, Kim BS, Beier JP. GPR55 inhibits the pro-adipogenic activity of anandamide in human adipose stromal cells. Exp Cell Res 2024; 435:113908. [PMID: 38163565 DOI: 10.1016/j.yexcr.2023.113908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/22/2023] [Accepted: 12/30/2023] [Indexed: 01/03/2024]
Abstract
The endocannabinoid anandamide (AEA) stimulates adipogenesis via the cannabinoid receptor CB1 in adipose stromal cells (ASCs). However, AEA interacts also with nonclassical cannabinoid receptors, including transient receptor potential cation channel (TRPV)1 and G protein-coupled receptor (GPR)55. Their roles in AEA mediated adipogenesis of human ASCs have not been investigated. We examined the receptor-expressions by immunostaining on human ASCs and tested their functionality by measuring the expression of immediate early genes (IEGs) related to the transcription factor-complex AP-1 upon exposition to receptor agonists. Cells were stimulated with increasing concentrations of specific ligands to investigate the effects on ASC viability (proliferation and metabolic activity), secretory activity, and AEA mediated differentiation. ASCs expressed both receptors, and their activation suppressed IEG expression. TRPV1 did not affect viability or cytokine secretion. GPR55 decreased proliferation, and it inhibited the release of hepatocyte growth factor. Blocking GPR55 increased the pro-adipogenic activity of AEA. These data suggest that GPR55 functions as negative regulator of cannabinoid mediated pro-adipogenic capacity in ASCs.
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Affiliation(s)
- Tim Ruhl
- Department of Plastic Surgery, Hand Surgery-Burn Center, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany.
| | - Aigul Nuptybayeva
- Department of Plastic Surgery, Hand Surgery-Burn Center, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany.
| | - Bong-Sung Kim
- Department of Plastic Surgery, Hand Surgery-Burn Center, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany; Department of Plastic and Hand Surgery, University Hospital Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
| | - Justus P Beier
- Department of Plastic Surgery, Hand Surgery-Burn Center, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany.
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3
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Hu T, Li Z, Gong C, Xiong Y, Sun S, Xing J, Li Y, Li R, Wang Y, Wang Y, Lin Y. FOS Inhibits the Differentiation of Intramuscular Adipocytes in Goats. Genes (Basel) 2023; 14:2088. [PMID: 38003034 PMCID: PMC10671551 DOI: 10.3390/genes14112088] [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: 09/27/2023] [Revised: 11/14/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
Goat intramuscular fat (IMF) deposition is precisely regulated by many key genes as well as transcription factors. Nevertheless, the potential of the regulators of goat IMF deposition remains undefined. In this work, we reported that the transcription factor FOS is expressed at a low level at the early differentiation stage and at a high level in late differentiation. The overexpression of FOS inhibited intramuscular adipocyte lipid accumulation and significantly downregulated the expressions of PPARγ, C/EBPβ, C/EBPα, AP2, SREBP1, FASN, ACC, HSL, and ATGL. Consistently, the knockdown of FOS, facilitated by two distinct siRNAs, significantly promoted intramuscular adipocyte lipid accumulation. Moreover, our analysis revealed multiple potential binding sites for FOS on the promoters of PPARγ, C/EBPβ, and C/EBPα. The expression changes in PPARγ, C/EBPβ, and C/EBPα during intramuscular adipogenesis were opposite to that of FOS. In summary, FOS inhibits intramuscular lipogenesis in goats and potentially negatively regulates the expressions of PPARγ, C/EBPβ, and C/EBPα genes. Our research will provide valuable data for the underlying molecular mechanism of the FOS regulation network of intramuscular lipogenesis.
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Affiliation(s)
- Tingting Hu
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Sichuan Province for Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation, Southwest Minzu University, Chengdu 610041, China
| | - Zhibin Li
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Sichuan Province for Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation, Southwest Minzu University, Chengdu 610041, China
| | - Chengsi Gong
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Sichuan Province for Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation, Southwest Minzu University, Chengdu 610041, China
| | - Yan Xiong
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Sichuan Province for Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation, Southwest Minzu University, Chengdu 610041, China
| | - Shiyu Sun
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
| | - Jiani Xing
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Sichuan Province for Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation, Southwest Minzu University, Chengdu 610041, China
| | - Yanyan Li
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Sichuan Province for Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation, Southwest Minzu University, Chengdu 610041, China
| | - Ruiwen Li
- Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Youli Wang
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Sichuan Province for Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation, Southwest Minzu University, Chengdu 610041, China
| | - Yong Wang
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Sichuan Province for Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation, Southwest Minzu University, Chengdu 610041, China
| | - Yaqiu Lin
- College of Animal Science and Veterinary, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory of Sichuan Province for Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation, Southwest Minzu University, Chengdu 610041, China
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4
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Jacob T, Annusver K, Czarnewski P, Dalessandri T, Kalk C, Levra Levron C, Campamà Sanz N, Kastriti ME, Mikkola ML, Rendl M, Lichtenberger BM, Donati G, Björklund ÅK, Kasper M. Molecular and spatial landmarks of early mouse skin development. Dev Cell 2023; 58:2140-2162.e5. [PMID: 37591247 PMCID: PMC11088744 DOI: 10.1016/j.devcel.2023.07.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 05/05/2023] [Accepted: 07/21/2023] [Indexed: 08/19/2023]
Abstract
A wealth of specialized cell populations within the skin facilitates its hair-producing, protective, sensory, and thermoregulatory functions. How the vast cell-type diversity and tissue architecture develops is largely unexplored. Here, with single-cell transcriptomics, spatial cell-type assignment, and cell-lineage tracing, we deconstruct early embryonic mouse skin during the key transitions from seemingly uniform developmental precursor states to a multilayered, multilineage epithelium, and complex dermal identity. We identify the spatiotemporal emergence of hair-follicle-inducing, muscle-supportive, and fascia-forming fibroblasts. We also demonstrate the formation of the panniculus carnosus muscle (PCM), sprouting blood vessels without pericyte coverage, and the earliest residence of mast and dendritic immune cells in skin. Finally, we identify an unexpected epithelial heterogeneity within the early single-layered epidermis and a signaling-rich periderm layer. Overall, this cellular and molecular blueprint of early skin development-which can be explored at https://kasperlab.org/tools-establishes histological landmarks and highlights unprecedented dynamic interactions among skin cells.
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Affiliation(s)
- Tina Jacob
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Karl Annusver
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Paulo Czarnewski
- Department of Biochemistry and Biophysics, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Stockholm University, 17165 Stockholm, Sweden
| | - Tim Dalessandri
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Christina Kalk
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Chiara Levra Levron
- Department of Life Sciences and Systems Biology, Molecular Biotechnology Center, University of Turin, 10126 Turin, Italy
| | - Nil Campamà Sanz
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Maria Eleni Kastriti
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
| | - Marja L Mikkola
- Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Michael Rendl
- Institute for Regenerative Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Beate M Lichtenberger
- Skin and Endothelium Research Division, Department of Dermatology, Medical University of Vienna, 1090 Vienna, Austria
| | - Giacomo Donati
- Department of Life Sciences and Systems Biology, Molecular Biotechnology Center, University of Turin, 10126 Turin, Italy
| | - Åsa K Björklund
- Department of Life Science, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Chalmers University of Technology, 41296 Göteborg, Sweden
| | - Maria Kasper
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
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5
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SPARC is a decoy counterpart for c‑Fos and is associated with osteoblastic differentiation of bone marrow stromal cells by inhibiting adipogenesis. Mol Med Rep 2023; 27:50. [PMID: 36633137 PMCID: PMC9879077 DOI: 10.3892/mmr.2023.12937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 11/13/2022] [Indexed: 01/11/2023] Open
Abstract
Secreted protein acidic and rich in cysteine (SPARC), also called basement‑membrane protein 40 or osteonectin, is a matricellular protein that is abundant not only in bone tissue as a non‑collagenous protein but is also ubiquitously expressed in non‑calcified tissue. SPARC is located intracellularly and disruption of the Sparc gene has been reported to reduce bone formation and increase fat tissue; however, the mechanism by which SPARC inhibits adipogenesis remains unclear. The present study evaluated the intracellular function of SPARC in adipogenesis using the bone marrow stromal cell line ST2. When ST2 cells with low SPARC production were cloned, intrinsic activator protein‑1 (AP‑1) activity was markedly higher, mineralized nodule formation was significantly lower and lipid accumulation was significantly increased compared with in the parental ST2 cells. Forced expression of secreted SPARC with the signal peptide‑coding sequences of wild‑type Sparc or preprotrypsin in SPARC‑low ST2 cells significantly reduced AP‑1 transcription activity; however, these reductions were not observed in the absence of signal peptide sequences. Recombinant SPARC, produced using Brevibacillus brevis, specifically bound to c‑Fos but not c‑Jun and inhibited the binding of c‑Fos/c‑Jun to a TPA‑response element sequence. These data suggested that SPARC was incorporated into the cells from the extracellular spaces and serves an intracellular role as a decoy counterpart for c‑Fos, as well as being associated with osteoblastogenesis through the inhibition of adipogenesis. These findings may provide new insights into regenerative medicine.
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6
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A functional genomics pipeline identifies pleiotropy and cross-tissue effects within obesity-associated GWAS loci. Nat Commun 2021; 12:5253. [PMID: 34489471 PMCID: PMC8421397 DOI: 10.1038/s41467-021-25614-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 08/20/2021] [Indexed: 02/07/2023] Open
Abstract
Genome-wide association studies (GWAS) have identified many disease-associated variants, yet mechanisms underlying these associations remain unclear. To understand obesity-associated variants, we generate gene regulatory annotations in adipocytes and hypothalamic neurons across cellular differentiation stages. We then test variants in 97 obesity-associated loci using a massively parallel reporter assay and identify putatively causal variants that display cell type specific or cross-tissue enhancer-modulating properties. Integrating these variants with gene regulatory information suggests genes that underlie obesity GWAS associations. We also investigate a complex genomic interval on 16p11.2 where two independent loci exhibit megabase-range, cross-locus chromatin interactions. We demonstrate that variants within these two loci regulate a shared gene set. Together, our data support a model where GWAS loci contain variants that alter enhancer activity across tissues, potentially with temporally restricted effects, to impact the expression of multiple genes. This complex model has broad implications for ongoing efforts to understand GWAS.
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7
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Wang F, Li X, Li Z, Wang S, Fan J. Functions of Circular RNAs in Regulating Adipogenesis of Mesenchymal Stem Cells. Stem Cells Int 2020; 2020:3763069. [PMID: 32802080 PMCID: PMC7416283 DOI: 10.1155/2020/3763069] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 12/17/2022] Open
Abstract
The mesenchymal stem cells (MSCs) are known as highly plastic stem cells and can differentiate into specialized tissues such as adipose tissue, osseous tissue, muscle tissue, and nervous tissue. The differentiation of mesenchymal stem cells is very important in regenerative medicine. Their differentiation process is regulated by signaling pathways of epigenetic, transcriptional, and posttranscriptional levels. Circular RNA (circRNA), a class of noncoding RNAs generated from protein-coding genes, plays a pivotal regulatory role in many biological processes. Accumulated studies have demonstrated that several circRNAs participate in the cell differentiation process of mesenchymal stem cells in vitro and in vivo. In the current review, characteristics and functions of circRNAs in stem cell differentiation will be discussed. The mechanism and key role of circRNAs in regulating mesenchymal stem cell differentiation, especially adipogenesis, will be reviewed and discussed. Understanding the roles of these circRNAs will present us with a more comprehensive signal path network of modulating stem cell differentiation and help us discover potential biomarkers and therapeutic targets in clinic.
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Affiliation(s)
- Fanglin Wang
- Department of Tissue Engineering, School of Fundamental Science, China Medical University, Shenyang, Liaoning 110122, China
| | - Xiang Li
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health, And Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, Liaoning 110122, China
| | - Zhiyuan Li
- Department of Tissue Engineering, School of Fundamental Science, China Medical University, Shenyang, Liaoning 110122, China
| | - Shoushuai Wang
- Department of Tissue Engineering, School of Fundamental Science, China Medical University, Shenyang, Liaoning 110122, China
| | - Jun Fan
- Department of Tissue Engineering, School of Fundamental Science, China Medical University, Shenyang, Liaoning 110122, China
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Chen N, Schill RL, O'Donnell M, Xu K, Bagchi DP, MacDougald OA, Koenig RJ, Xu B. The transcription factor NKX1-2 promotes adipogenesis and may contribute to a balance between adipocyte and osteoblast differentiation. J Biol Chem 2019; 294:18408-18420. [PMID: 31615896 DOI: 10.1074/jbc.ra119.007967] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 10/04/2019] [Indexed: 11/06/2022] Open
Abstract
Although adipogenesis is mainly controlled by a small number of master transcription factors, including CCAAT/enhancer-binding protein family members and peroxisome proliferator-activated receptor γ (PPARγ), other transcription factors also are involved in this process. Thyroid cancer cells expressing a paired box 8 (PAX8)-PPARγ fusion oncogene trans-differentiate into adipocyte-like cells in the presence of the PPARγ ligand pioglitazone, but this trans-differentiation is inhibited by the transcription factor NK2 homeobox 1 (NKX2-1). Here, we tested whether NKX family members may play a role also in normal adipogenesis. Using quantitative RT-PCR (RT-qPCR), we examined the expression of all 14 NKX family members during 3T3-L1 adipocyte differentiation. We found that most NKX members, including NKX2-1, are expressed at very low levels throughout differentiation. However, mRNA and protein expression of a related family member, NKX1-2, was induced during adipocyte differentiation. NKX1-2 also was up-regulated in cultured murine ear mesenchymal stem cells (EMSCs) during adipogenesis. Importantly, shRNA-mediated NKX1-2 knockdown in 3T3-L1 preadipocytes or EMSCs almost completely blocked adipocyte differentiation. Furthermore, NKX1-2 overexpression promoted differentiation of the ST2 bone marrow-derived mesenchymal precursor cell line into adipocytes. Additional findings suggested that NKX1-2 promotes adipogenesis by inhibiting expression of the antiadipogenic protein COUP transcription factor II. Bone marrow mesenchymal precursor cells can differentiate into adipocytes or osteoblasts, and we found that NKX1-2 both promotes ST2 cell adipogenesis and inhibits their osteoblastogenic differentiation. These results support a role for NKX1-2 in promoting adipogenesis and possibly in regulating the balance between adipocyte and osteoblast differentiation of bone marrow mesenchymal precursor cells.
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Affiliation(s)
- Noah Chen
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Rebecca L Schill
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Michael O'Donnell
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Kevin Xu
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Devika P Bagchi
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Ormond A MacDougald
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109; Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Ronald J Koenig
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Bin Xu
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109.
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Hao Y, Song J, Ravikrishnan A, Dicker KT, Fowler EW, Zerdoum AB, Li Y, Zhang H, Rajasekaran AK, Fox JM, Jia X. Rapid Bioorthogonal Chemistry Enables in Situ Modulation of the Stem Cell Behavior in 3D without External Triggers. ACS APPLIED MATERIALS & INTERFACES 2018; 10:26016-26027. [PMID: 30015482 PMCID: PMC6214352 DOI: 10.1021/acsami.8b07632] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Chemical modification of engineered microenvironments surrounding living cells represents a means for directing cellular behaviors through cell-matrix interactions. Presented here is a temporally controlled method for modulating the properties of biomimetic, synthetic extracellular matrices (ECM) during live cell culture employing the rapid, bioorthogonal tetrazine ligation with trans-cyclooctene (TCO) dienophiles. This approach is diffusion-controlled, cytocompatible, and does not rely on light, catalysts, or other external triggers. Human bone-marrow-derived mesenchymal stem cells (hMSCs) were initially entrapped in a hydrogel prepared using hyaluronic acid carrying sulfhydryl groups (HA-SH) and a hydrophilic polymer bearing both acrylate and tetrazine groups (POM-AT). Inclusion of a matrix metalloprotease (MMP)-degradable peptidic cross-linker enabled hMSC-mediated remodeling of the synthetic environment. The resultant network displayed dangling tetrazine groups for subsequent conjugation with TCO derivatives. Two days later, the stiffness of the matrix was increased by adding chemically modified HA carrying multiple copies of TCO (HA-TCO) to the hMSC growth media surrounding the cell-laden gel construct. In response, cells developed small processes radially around the cell body without a significant alteration of the overall shape. By contrast, modification of the 3D matrix with a TCO-tagged cell-adhesive motif caused the resident cells to undergo significant actin polymerization, changing from a rounded shape to spindle morphology with long cellular processes. After additional 7 days of culture in the growth media, quantitative analysis showed that, at the mRNA level, RGD tagging upregulated cellular expression of MMP1, but downregulated the expression of collagen I/III and tenascin C. RGD tagging, however, was not sufficient to induce the classic osteoblastic, chondrogenic, adipogenic, or fibroblastic/myofibroblastic differentiation. The modular approach allows facile manipulation of synthetic ECM to modulate cell behavior, thus potentially applicable to the engineering of functional tissues or tissue models.
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Affiliation(s)
- Ying Hao
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Jiyeon Song
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Anitha Ravikrishnan
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Kevin T. Dicker
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Eric W. Fowler
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Aidan B. Zerdoum
- Department of Biomedical Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Yi Li
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, USA
| | - He Zhang
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, 19716, USA
| | | | - Joseph M. Fox
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, 19716, USA
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, USA
| | - Xinqiao Jia
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, 19716, USA
- Department of Biomedical Engineering, University of Delaware, Newark, DE, 19716, USA
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10
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Bou M, Montfort J, Le Cam A, Rallière C, Lebret V, Gabillard JC, Weil C, Gutiérrez J, Rescan PY, Capilla E, Navarro I. Gene expression profile during proliferation and differentiation of rainbow trout adipocyte precursor cells. BMC Genomics 2017; 18:347. [PMID: 28472935 PMCID: PMC5418865 DOI: 10.1186/s12864-017-3728-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 04/26/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Excessive accumulation of adipose tissue in cultured fish is an outstanding problem in aquaculture. To understand the development of adiposity, it is crucial to identify the genes which expression is associated with adipogenic differentiation. Therefore, the transcriptomic profile at different time points (days 3, 8, 15 and 21) along primary culture development of rainbow trout preadipocytes has been investigated using an Agilent trout oligo microarray. RESULTS Our analysis identified 4026 genes differentially expressed (fold-change >3) that were divided into two major clusters corresponding to the main phases observed during the preadipocyte culture: proliferation and differentiation. Proliferation cluster comprised 1028 genes up-regulated from days 3 to 8 of culture meanwhile the differentiation cluster was characterized by 2140 induced genes from days 15 to 21. Proliferation was characterized by enrichment in genes involved in basic cellular and metabolic processes (transcription, ribosome biogenesis, translation and protein folding), cellular remodelling and autophagy. In addition, the implication of the eicosanoid signalling pathway was highlighted during this phase. On the other hand, the terminal differentiation phase was enriched with genes involved in energy production, lipid and carbohydrate metabolism. Moreover, during this phase an enrichment in genes involved in the formation of the lipid droplets was evidenced as well as the activation of the thyroid-receptor/retinoic X receptor (TR/RXR) and the peroxisome proliferator activated receptors (PPARs) signalling pathways. The whole adipogenic process was driven by a coordinated activation of transcription factors and epigenetic modulators. CONCLUSIONS Overall, our study demonstrates the coordinated expression of functionally related genes during proliferation and differentiation of rainbow trout adipocyte cells. Furthermore, the information generated will allow future investigations of specific genes involved in particular stages of fish adipogenesis.
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Affiliation(s)
- Marta Bou
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain.,Present address: Nofima (Norwegian Institute of Food, Fisheries, and Aquaculture Research), P.O. Box 210, N-1432, Ås, Norway
| | - Jerôme Montfort
- INRA, UR1037 Laboratory of Fish Physiology and Genomics, Campus de Beaulieu, Rennes, F-35042, France
| | - Aurélie Le Cam
- INRA, UR1037 Laboratory of Fish Physiology and Genomics, Campus de Beaulieu, Rennes, F-35042, France
| | - Cécile Rallière
- INRA, UR1037 Laboratory of Fish Physiology and Genomics, Campus de Beaulieu, Rennes, F-35042, France
| | - Véronique Lebret
- INRA, UR1037 Laboratory of Fish Physiology and Genomics, Campus de Beaulieu, Rennes, F-35042, France
| | - Jean-Charles Gabillard
- INRA, UR1037 Laboratory of Fish Physiology and Genomics, Campus de Beaulieu, Rennes, F-35042, France
| | - Claudine Weil
- INRA, UR1037 Laboratory of Fish Physiology and Genomics, Campus de Beaulieu, Rennes, F-35042, France
| | - Joaquim Gutiérrez
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - Pierre-Yves Rescan
- INRA, UR1037 Laboratory of Fish Physiology and Genomics, Campus de Beaulieu, Rennes, F-35042, France
| | - Encarnación Capilla
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - Isabel Navarro
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain.
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11
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Mota de Sá P, Richard AJ, Hang H, Stephens JM. Transcriptional Regulation of Adipogenesis. Compr Physiol 2017; 7:635-674. [PMID: 28333384 DOI: 10.1002/cphy.c160022] [Citation(s) in RCA: 242] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Adipocytes are the defining cell type of adipose tissue. Once considered a passive participant in energy storage, adipose tissue is now recognized as a dynamic organ that contributes to several important physiological processes, such as lipid metabolism, systemic energy homeostasis, and whole-body insulin sensitivity. Therefore, understanding the mechanisms involved in its development and function is of great importance. Adipocyte differentiation is a highly orchestrated process which can vary between different fat depots as well as between the sexes. While hormones, miRNAs, cytoskeletal proteins, and many other effectors can modulate adipocyte development, the best understood regulators of adipogenesis are the transcription factors that inhibit or promote this process. Ectopic expression and knockdown approaches in cultured cells have been widely used to understand the contribution of transcription factors to adipocyte development, providing a basis for more sophisticated in vivo strategies to examine adipogenesis. To date, over two dozen transcription factors have been shown to play important roles in adipocyte development. These transcription factors belong to several families with many different DNA-binding domains. While peroxisome proliferator-activated receptor gamma (PPARγ) is undoubtedly the most important transcriptional modulator of adipocyte development in all types of adipose tissue, members of the CCAAT/enhancer-binding protein, Krüppel-like transcription factor, signal transducer and activator of transcription, GATA, early B cell factor, and interferon-regulatory factor families also regulate adipogenesis. The importance of PPARγ activity is underscored by several covalent modifications that modulate its activity and its ability to modulate adipocyte development. This review will primarily focus on the transcriptional control of adipogenesis in white fat cells and on the mechanisms involved in this fine-tuned developmental process. © 2017 American Physiological Society. Compr Physiol 7:635-674, 2017.
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Affiliation(s)
- Paula Mota de Sá
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Allison J Richard
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Hardy Hang
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Jacqueline M Stephens
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
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12
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Grossman SR, Zhang X, Wang L, Engreitz J, Melnikov A, Rogov P, Tewhey R, Isakova A, Deplancke B, Bernstein BE, Mikkelsen TS, Lander ES. Systematic dissection of genomic features determining transcription factor binding and enhancer function. Proc Natl Acad Sci U S A 2017; 114:E1291-E1300. [PMID: 28137873 PMCID: PMC5321001 DOI: 10.1073/pnas.1621150114] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Enhancers regulate gene expression through the binding of sequence-specific transcription factors (TFs) to cognate motifs. Various features influence TF binding and enhancer function-including the chromatin state of the genomic locus, the affinities of the binding site, the activity of the bound TFs, and interactions among TFs. However, the precise nature and relative contributions of these features remain unclear. Here, we used massively parallel reporter assays (MPRAs) involving 32,115 natural and synthetic enhancers, together with high-throughput in vivo binding assays, to systematically dissect the contribution of each of these features to the binding and activity of genomic regulatory elements that contain motifs for PPARγ, a TF that serves as a key regulator of adipogenesis. We show that distinct sets of features govern PPARγ binding vs. enhancer activity. PPARγ binding is largely governed by the affinity of the specific motif site and higher-order features of the larger genomic locus, such as chromatin accessibility. In contrast, the enhancer activity of PPARγ binding sites depends on varying contributions from dozens of TFs in the immediate vicinity, including interactions between combinations of these TFs. Different pairs of motifs follow different interaction rules, including subadditive, additive, and superadditive interactions among specific classes of TFs, with both spatially constrained and flexible grammars. Our results provide a paradigm for the systematic characterization of the genomic features underlying regulatory elements, applicable to the design of synthetic regulatory elements or the interpretation of human genetic variation.
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Affiliation(s)
- Sharon R Grossman
- Broad Institute, Cambridge, MA 02142
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
- Health Sciences and Technology, Harvard Medical School, Boston, MA 02215
| | | | - Li Wang
- Broad Institute, Cambridge, MA 02142
| | - Jesse Engreitz
- Broad Institute, Cambridge, MA 02142
- Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | | | | | - Ryan Tewhey
- Broad Institute, Cambridge, MA 02142
- Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138
| | - Alina Isakova
- Institute of Bioengineering, CH-1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics, CH-1015 Lausanne, Switzerland
| | - Bart Deplancke
- Institute of Bioengineering, CH-1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics, CH-1015 Lausanne, Switzerland
| | - Bradley E Bernstein
- Broad Institute, Cambridge, MA 02142
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114
- Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114
| | - Tarjei S Mikkelsen
- Broad Institute, Cambridge, MA 02142
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138
| | - Eric S Lander
- Broad Institute, Cambridge, MA 02142;
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
- Department of Systems Biology, Harvard Medical School, Boston, MA 02215
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13
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Siebert A, Goren I, Pfeilschifter J, Frank S. Anti-Inflammatory Effects of Rosiglitazone in Obesity-Impaired Wound Healing Depend on Adipocyte Differentiation. PLoS One 2016; 11:e0168562. [PMID: 27992530 PMCID: PMC5167406 DOI: 10.1371/journal.pone.0168562] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 12/02/2016] [Indexed: 12/21/2022] Open
Abstract
Combined diabetes-obesity syndromes severely impair regeneration of acute skin wounds in mouse models. This study assessed the contribution of subcutaneous adipose tissue to exacerbated wound inflammatory conditions. Genetically obese (ob/ob) mice showed an increased expression of positive transcriptional effectors of adipocyte differentiation such as Krüppel-like factor (KLF)-5 and peroxisome proliferator-activated receptor (PPAR)-γ and an associated expression of leptin and fatty acid-binding protein (FABP)-4, but also CXCL2 in isolated subcutaneous fat. This observation in obese mice is in keeping with differentially elevated levels of KLF-5, PPAR-γ, leptin, FABP-4 and CXCL2 in in vitro-differentiated 3T3-L1 adipocytes. Notably, CXCL2 expression restrictively appeared upon cytokine (IL-1β/TNF-α) stimulation only in mature, but not immature 3T3-L1 adipocytes. Of importance, the critical regulator of adipocyte maturation, PPAR-γ, was merely expressed in the final phase of in-vitro induced adipocyte differentiation from 3T3-L1 pre-adipocytes. Consistently, the PPAR-γ agonist rosiglitazone suppressed cytokine-induced CXCL2 release from mature adipocytes, but not from early 3T3-L1 adipocyte stages. The inhibitory effect of PPAR-γ activation on CXCL2 release appeared to be a general anti-inflammatory effect in mature adipocytes, as cytokine-induced cyclooxygenase (Cox)-2 was simultaneously repressed by rosiglitazone. In accordance with these findings, oral administration of rosiglitazone to wounded obese mice significantly changed subcutaneous adipocyte morphology, reduced wound CXCL2 and Cox-2 expression and improved tissue regeneration. Thus, our data suggest that PPAR-γ might provide a target to suppress inflammatory signals from mature adipocytes, which add to the prolonged wound inflammation observed in diabetes-obesity conditions.
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Affiliation(s)
- Anna Siebert
- Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, Frankfurt am Main, Germany
| | - Itamar Goren
- Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, Frankfurt am Main, Germany
- * E-mail:
| | - Josef Pfeilschifter
- Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, Frankfurt am Main, Germany
| | - Stefan Frank
- Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, Frankfurt am Main, Germany
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14
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Lu YH, Dallner OS, Birsoy K, Fayzikhodjaeva G, Friedman JM. Nuclear Factor-Y is an adipogenic factor that regulates leptin gene expression. Mol Metab 2015; 4:392-405. [PMID: 25973387 PMCID: PMC4420997 DOI: 10.1016/j.molmet.2015.02.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 02/05/2015] [Indexed: 12/22/2022] Open
Abstract
Objective Leptin gene expression is highly correlated with cellular lipid content in adipocytes but the transcriptional mechanisms controlling leptin expression in vivo are poorly understood. In this report, we set out to identify cis- and trans-regulatory elements controlling leptin expression. Methods Leptin-BAC luciferase transgenic mice combining with other computational and molecular techniques were used to identify transcription regulatory elements including a CCAAT-binding protein Nuclear Factor Y (NF-Y). The function of NF-Y in adipocyte was studied in vitro with 3T3-L1 cells and in vivo with adipocyte-specific knockout of NF-Y. Results Using Leptin-BAC luciferase mice, we showed that DNA sequences between −22 kb and +8.8 kb can confer quantitative expression of a leptin reporter. Computational analysis of sequences and gel shift assays identified a 32 bp sequence (chr6: 28993820–2899385) consisting a CCAAT binding site for Nuclear Factor Y (NF-Y) and this was confirmed by a ChIP assay in vivo. A deletion of this 32 bp sequence in the −22 kb to +8.8 kb leptin-luciferase BAC reporter completely abrogates luciferase reporter activity in vivo. RNAi mediated knockdown of NF-Y interfered with adipogenesis in vitro and adipocyte-specific knockout of NF-Y in mice reduced expression of leptin and other fat specific genes in vivo. Further analyses of the fat specific NF-Y knockout revealed that these animals develop a moderately severe lipodystrophy that is remediable with leptin therapy. Conclusions These studies advance our understanding of leptin gene expression and show that NF-Y controls the expression of leptin and other adipocyte genes and identifies a new form of lipodystrophy.
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Affiliation(s)
- Yi-Hsueh Lu
- Laboratory of Molecular Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Olof Stefan Dallner
- Laboratory of Molecular Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Kivanc Birsoy
- Laboratory of Molecular Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Gulya Fayzikhodjaeva
- Laboratory of Molecular Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Jeffrey M Friedman
- Laboratory of Molecular Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA ; Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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15
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Nikolopoulou E, Papacleovoulou G, Jean-Alphonse F, Grimaldi G, Parker MG, Hanyaloglu AC, Christian M. Arachidonic acid-dependent gene regulation during preadipocyte differentiation controls adipocyte potential. J Lipid Res 2014; 55:2479-90. [PMID: 25325755 PMCID: PMC4242441 DOI: 10.1194/jlr.m049551] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Arachidonic acid (AA) is a major PUFA that has been implicated in the regulation of adipogenesis. We examined the effect of a short exposure to AA at different stages of 3T3-L1 adipocyte differentiation. AA caused the upregulation of fatty acid binding protein 4 (FABP4/aP2) following 24 h of differentiation. This was mediated by the prostaglandin F2α (PGF2α), as inhibition of cyclooxygenases or PGF2α receptor signaling counteracted the AA-mediated aP2 induction. In addition, calcium, protein kinase C, and ERK are all key elements of the pathway through which AA induces the expression of aP2. We also show that treatment with AA during the first 24 h of differentiation upregulates the expression of the transcription factor Fos-related antigen 1 (Fra-1) via the same pathway. Finally, treatment with AA for 24 h at the beginning of the adipocyte differentiation is sufficient to inhibit the late stages of adipogenesis through a Fra-1-dependent pathway, as Fra-1 knockdown rescued adipogenesis. Our data show that AA is able to program the differentiation potential of preadipocytes by regulating gene expression at the early stages of adipogenesis.
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Affiliation(s)
- Evanthia Nikolopoulou
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK
| | | | - Frederic Jean-Alphonse
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK
| | - Giulia Grimaldi
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK
| | - Malcolm G Parker
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK
| | - Aylin C Hanyaloglu
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK
| | - Mark Christian
- Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, UK
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16
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Ponomarev IV, Lawton BK, Williams DE, Schnell JD. Breakthrough paper indicator 2.0: can geographical diversity and interdisciplinarity improve the accuracy of outstanding papers prediction? Scientometrics 2014. [DOI: 10.1007/s11192-014-1320-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Flachs P, Rossmeisl M, Kuda O, Kopecky J. Stimulation of mitochondrial oxidative capacity in white fat independent of UCP1: A key to lean phenotype. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:986-1003. [DOI: 10.1016/j.bbalip.2013.02.003] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 02/06/2013] [Accepted: 02/09/2013] [Indexed: 02/06/2023]
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18
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Pott S, Kamrani NK, Bourque G, Pettersson S, Liu ET. PPARG binding landscapes in macrophages suggest a genome-wide contribution of PU.1 to divergent PPARG binding in human and mouse. PLoS One 2012; 7:e48102. [PMID: 23118933 PMCID: PMC3485280 DOI: 10.1371/journal.pone.0048102] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 09/24/2012] [Indexed: 12/22/2022] Open
Abstract
Background Genome-wide comparisons of transcription factor binding sites in different species can be used to evaluate evolutionary constraints that shape gene regulatory circuits and to understand how the interaction between transcription factors shapes their binding landscapes over evolution. Results We have compared the PPARG binding landscapes in macrophages to investigate the evolutionary impact on PPARG binding diversity in mouse and humans for this important nuclear receptor. Of note, only 5% of the PPARG binding sites were shared between the two species. In contrast, at the gene level, PPARG target genes conserved between both species constitute more than 30% of the target genes regulated by PPARG ligand in human macrophages. Moreover, the majority of all PPARG binding sites (55–60%) in macrophages show co-occupancy of the lineage-specification factor PU.1 in both species. Exploring the evolutionary dynamics of PPARG binding sites, we observed that PU.1 co-binding to PPARG sites appears to be important for possible PPARG ancestral functions such as lipid metabolism. Thus we speculate that PU.1 may have guided utilization of these species-specific PPARG conserved binding sites in macrophages during evolution. Conclusions We propose a model in which PU.1 sites may have served as “anchor” loci for the formation of new and functionally relevant PPARG binding sites throughout evolution. As PU.1 is an essential factor in macrophage biology, such an evolutionary mechanism would allow for the establishment of relevant PPARG regulatory modules in a PU.1-dependent manner and yet permit for nuanced regulatory changes in individual species.
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Affiliation(s)
- Sebastian Pott
- Cancer Biology and Pharmacology 2, Genome Institute of Singapore, Singapore, Singapore
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Nima K. Kamrani
- Cancer Biology and Pharmacology 2, Genome Institute of Singapore, Singapore, Singapore
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- National Cancer Centre, Singapore, Singapore
| | - Guillaume Bourque
- Computational and Systems Biology, Genome Institute of Singapore, Singapore, Singapore
| | - Sven Pettersson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- National Cancer Centre, Singapore, Singapore
- * E-mail: (SP); (ETL)
| | - Edison T. Liu
- Cancer Biology and Pharmacology 2, Genome Institute of Singapore, Singapore, Singapore
- * E-mail: (SP); (ETL)
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19
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Quinn JP. Variation in the composition of the AP1 complex in PC12 cells following induction by NGF and TPA. Mol Cell Neurosci 2012; 2:253-8. [PMID: 19912806 DOI: 10.1016/1044-7431(91)90052-p] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/1991] [Indexed: 10/26/2022] Open
Abstract
The rat pheochromocytoma cell line PC 12 differentiates in response to NGF. Exposure to NGF induces a class of genes termed immediate early that includes many transcription factors including c-jun and c-fos which can constitute the AP1 complex. Induction of such transcription factors by NGF could be a method by which the cell redirects its program of gene expression that results in differentiation. In this study, it is demonstrated that the complement of transcription factors that constitute the AP1 complex alters with the continued passage of PC12 cells. PC 12 cells from early passage contain no AP1 activity, whereas with passage the cells constitutively express an AP1 complex; however, no morphological differences are observed. The AP1 binding activity can be further induced in all PC12 cells studied by NGF or TPA. The analysis of c-jun, c-fos, and the fos-related antigens that can constitute the AP1 complex demonstrated compositional variation of this complex by passage in culture and by exposure to NGF or TPA. As these AP1 transcription complexes may mediate the action of NGF in PC12 cells it is important to correlate the changes in composition of the complex with differentiation.
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Affiliation(s)
- J P Quinn
- MRC Brain Metabolism Unit, Royal Edinburgh Hospital, Morningside Park, Edinburgh, EH10 5HF, United Kingdom
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20
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Abstract
Adipose tissue is an important site for lipid storage, energy homeostasis, and whole-body insulin sensitivity. It is important to understand the mechanisms involved in adipose tissue development and function, which can be regulated by the endocrine actions of various peptide and steroid hormones. Recent studies have revealed that white and brown adipocytes can be derived from distinct precursor cells. This review will focus on transcriptional control of adipogenesis and its regulation by several endocrine hormones. The general functions and cellular origins of adipose tissue and how the modulation of adipocyte development pertains to metabolic disease states will also be considered.
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21
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Wrann CD, Eguchi J, Bozec A, Xu Z, Mikkelsen T, Gimble J, Nave H, Wagner EF, Ong SE, Rosen ED. FOSL2 promotes leptin gene expression in human and mouse adipocytes. J Clin Invest 2012; 122:1010-21. [PMID: 22326952 DOI: 10.1172/jci58431] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/04/2012] [Indexed: 12/16/2022] Open
Abstract
The adipocyte-derived hormone leptin is a critical regulator of many physiological functions, ranging from satiety to immunity. Surprisingly, very little is known about the transcriptional pathways that regulate adipocyte-specific expression of leptin. Here, we report studies in which we pursued a strategy integrating BAC transgenic reporter mice, reporter assays, and chromatin state mapping to locate an adipocyte-specific cis-element upstream of the leptin (LEP) gene in human fat cells. Quantitative proteomics with affinity enrichment of protein-DNA complexes identified the transcription factor FOS-like antigen 2 (FOSL2) as binding specifically to the identified region, a result that was confirmed by ChIP. Knockdown of FOSL2 in human adipocytes decreased LEP expression, and overexpression of Fosl2 increased Lep expression in mouse adipocytes. Moreover, the elevated LEP expression observed in obesity correlated well with increased FOSL2 levels in mice and humans, and adipocyte-specific genetic deletion of Fosl2 in mice reduced Lep expression. Taken together, these data identify FOSL2 as a critical regulator of leptin expression in adipocytes.
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Affiliation(s)
- Christiane D Wrann
- Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA
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22
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Mosialou I, Krasagakis K, Kardassis D. Opposite regulation of the human apolipoprotein M gene by hepatocyte nuclear factor 1 and Jun transcription factors. J Biol Chem 2011; 286:17259-69. [PMID: 21454713 DOI: 10.1074/jbc.m110.200659] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
HDL is a negative risk factor for atherosclerosis because of its multiple atheroprotective functions. Inflammation converts HDL particles from anti-atherogenic to pro-atherogenic, and this transformation is associated with changes in HDL structure and composition. Apolipoprotein M (apoM) has been recently shown to play a role in the maturation of HDL in plasma and to protect from atherosclerosis. ApoM gene is expressed primarily in the liver and kidney and is down-regulated by pro-inflammatory signals. We now show that the human apoM promoter harbors a dual specificity regulatory element in the proximal region that binds hepatocyte nuclear factor 1 (HNF-1) and members of the AP-1 family of pro-inflammatory transcription factors (c-Jun and JunB). Overexpression of c-Jun or JunB repressed both the basal and the HNF-1-mediated transactivation of the human apoM promoter. Treatment of HepG2 cells with potent inflammation-inducing phorbol esters or overexpression of PKCα was associated with a marked inhibition of apoM gene expression in a c-Jun/JunB-dependent manner. We provide evidence for a novel mechanism of inflammation-induced transcriptional repression that is based on the competition between HNF-1 and Jun proteins for binding to the same regulatory region. A similar mechanism accounts for the down-regulation of the liver-specific apolipoprotein A-II gene by Jun factors. Our studies provide novel insights on the mechanisms that control the expression of liver-specific apolipoprotein genes during inflammation and could affect the maturation and the functionality of HDL particles.
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Affiliation(s)
- Ioanna Mosialou
- Department of Basic Sciences, University of Crete Medical School, Heraklion 71003, Greece
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23
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Smit LS, Meyer DJ, Argetsinger LS, Schwartz J, Carter‐Su C. Molecular Events in Growth Hormone–Receptor Interaction and Signaling. Compr Physiol 2011. [DOI: 10.1002/cphy.cp070514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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24
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Xiao H, Leblanc SE, Wu Q, Konda S, Salma N, Marfella CGA, Ohkawa Y, Imbalzano AN. Chromatin accessibility and transcription factor binding at the PPARγ2 promoter during adipogenesis is protein kinase A-dependent. J Cell Physiol 2010; 226:86-93. [PMID: 20625991 DOI: 10.1002/jcp.22308] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcription factor that specifies formation of the adipocyte lineage. PPARγ also serves as a primary target for the treatment of type 2 diabetes, illustrating both its medical relevance as well as the need to understand fundamental aspects of PPARγ expression and function. Here, we characterize molecular changes that occur at the PPARγ2 promoter within the first several hours of adipocyte differentiation in culture. Our results demonstrate that changes in chromatin accessibility at the PPARγ2 promoter and occupancy of the promoter by the c-Fos transcription factor occur within an hour of the onset of differentiation, followed closely by the binding of the CCAAT/enhancer binding protein beta (C/EBPβ) transcription factor. All three events show a remarkable dependency on protein kinase A (PKA) activity. These results reflect novel requirements for the PKA signaling pathway and reinforce the importance of PKA function during the onset of adipocyte differentiation.
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Affiliation(s)
- Hengyi Xiao
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
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25
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Coleman SL, Park YK, Lee JY. Unsaturated fatty acids repress the expression of adipocyte fatty acid binding protein via the modulation of histone deacetylation in RAW 264.7 macrophages. Eur J Nutr 2010; 50:323-30. [PMID: 21046125 DOI: 10.1007/s00394-010-0140-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 10/18/2010] [Indexed: 01/07/2023]
Abstract
BACKGROUND Adipocyte fatty acid binding protein (A-FABP) present in macrophages has been implicated in the integration of lipid metabolism and inflammatory response, contributing to development of insulin resistance and atherosclerosis. AIM OF THE STUDY This study was conducted to test the hypothesis that the role of fatty acids in the inflammatory pathways is mediated through the modulation of A-FABP expression in macrophages. METHODS Murine RAW 264.7 macrophages were treated with inflammatory insults and fatty acids for quantitative real-time PCR and Western blot analysis. The cells were treated with trichostatin A (TSA), a histone deacetylase inhibitor, for elucidating mechanisms for the regulation of A-FABP expression by fatty acids. RNA interference (RNAi) to knock down A-FABP was utilized to assess its role in inflammatory gene expression. RESULTS When RAW 264.7 were incubated with lipopolysaccharides (LPS; 100 ng/ml) or 2.5 ng/ml of tumor necrosis factor α for 18 h, A-FABP mRNA and protein levels were drastically increased. Unsaturated fatty acids (100 μmol/l in complexed with BSA) such as palmitoleic acid, oleic acid, linoleic acid, linolenic acid, and eicosapentaenoic acid, significantly repressed the basal as well as LPS-induced A-FABP expression, whereas palmitic acid did not elicit the same effect. TSA increased A-FABP mRNA levels and abolished the repressive effect of linoleic acid on A-FABP expression in unstimulated and LPS-stimulated macrophages. Depletion of A-FABP expression by 70-80% using RNAi markedly decreased cyclooxygenase 2 mRNA abundance and potentiated the repression by linoleic acid. CONCLUSION Unsaturated fatty acids inhibited the basal as well as LPS-induced A-FABP expression. The mechanism may involve histone deacetylation and anti-inflammatory effect of unsaturated fatty acids may be at least in part attributed to their repression of A-FABP expression in RAW 264.7 macrophages.
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Affiliation(s)
- Sara L Coleman
- Department of Nutrition and Health Sciences, University of Nebraska, Lincoln, 68583, USA
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White UA, Stephens JM. Transcriptional factors that promote formation of white adipose tissue. Mol Cell Endocrinol 2010; 318:10-4. [PMID: 19733624 PMCID: PMC3079373 DOI: 10.1016/j.mce.2009.08.023] [Citation(s) in RCA: 255] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 08/26/2009] [Accepted: 08/30/2009] [Indexed: 10/20/2022]
Abstract
Adipocytes are highly specialized cells that play a major role in energy homeostasis in vertebrate organisms. Excess adipocyte size or number is a hallmark of obesity, which is currently a global epidemic. Obesity is a major risk factor for the development of type II diabetes (T2DM), cardiovascular disease, and hypertension. Obesity and its related disorders result in dysregulation of the mechanisms that control the expression of metabolic and endocrine related genes in adipocytes. Therefore, understanding adipocyte differentiation is relevant not only for gaining insight into the pathogenesis of metabolic diseases, but also for identifying proteins or pathways which might be appropriate targets for pharmacological interventions. Significant advances towards an understanding of the regulatory processes involved in adipocyte differentiation have largely been made by the identification of transcription factors that contribute to the adipogenic process. It is important to note that the developmental origin of white and brown fat is distinct and different precursor cells are involved in the generation of these different types of adipose tissue (reviewed in Lefterova and Lazar, 2009; Seale et al., 2009). Several transcription factors, notably PPAR gamma, several members of the C/EBP and KLF families, STAT5, and SREBP-1c, have been shown to have significant roles in promoting adipogenesis. More comprehensive reviews on negative and positive regulators of adipogenesis have been published in the past year (reviewed in Christodoulides et al., 2009; Lefterova and Lazar, 2009). Though many proteins are known to negatively regulate adipogenesis, including Wnts, KLFs, the E2F family of transcription factors, CHOP, Delta-interacting protein A, ETO/MTG8, and members of the GATA and forkhead transcription factor families, this review will focus on transcription factors that positively impact the development of white adipose tissue.
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Affiliation(s)
| | - Jacqueline M. Stephens
- Corresponding author at: Louisiana State University, Department of Biological Sciences, 202 Life Sciences Bldg., Baton Rouge, LA 70803, USA. Tel.: +1 225 578 1749; fax: +1 225 578 2597. (J.M. Stephens)
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Haga A, Nagai H, Deyashiki Y. Autotaxin Promotes the Expression of Matrix Metalloproteinase-3 via Activation of the MAPK Cascade in Human FibrosarcomaHT-1080Cells. Cancer Invest 2009; 27:384-90. [DOI: 10.1080/07357900802491469] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Zhang L, Reidy SP, Nicholson TE, Lee HJ, Majdalawieh A, Webber C, Stewart BR, Dolphin P, Ro HS. The role of AEBP1 in sex-specific diet-induced obesity. Mol Med 2009; 11:39-47. [PMID: 16307171 PMCID: PMC1449517 DOI: 10.2119/2005-00021.ro] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2005] [Accepted: 10/24/2005] [Indexed: 12/22/2022] Open
Abstract
Obesity is an important risk factor for heart disease, diabetes, and certain cancers, but the molecular basis for obesity is poorly understood. The transcriptional repressor AEBP1, which functions as a negative regulator of PTEN through a protein-protein interaction, is highly expressed in the stromal compartment of adipose tissues, including proliferative preadipocytes, and its expression is abolished in terminally differentiated, nonproliferative adipocytes. Here we show that transgenic overexpression of AEBP1 during adipogenesis coupled with a high-fat diet (HFD) resulted in massive obesity in female transgenic (AEBP1(TG)) mice via adipocyte hyperplasia. AEBP1 levels dynamically changed with aging, and HFD induced AEBP1 expression in females. Thus, HFD-fed AEBP1(TG) females display hyperinduction of AEBP1 and a marked reduction of PTEN level with concomitant hyperactivation of the survival signal in white adipose tissue. Our results suggest that AEBP1 plays a key functional role in in vivo modulation of adiposity via fat-cell proliferation and is involved in a sex-specific susceptibility to diet-induced obesity by the estrogen signaling pathway.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Hyo-Sung Ro
- Address correspondence and reprint requests to Hyo-Sung Ro, Department of Biochemistry & Molecular Biology, Faculty of Medicine, Dalhousie University, Tupper Medical Building, 1850 College Street, Halifax, NS, B3H 1X5 Canada. Phone: 902-494-2367; fax 902-494-1355; e-mail:
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Lampidonis AD, Stravopodis DJ, Voutsinas GE, Messini-Nikolaki N, Stefos GC, Margaritis LH, Argyrokastritis A, Bizelis I, Rogdakis E. Cloning and functional characterization of the 5′ regulatory region of ovine Hormone Sensitive Lipase (HSL) gene. Gene 2008; 427:65-79. [DOI: 10.1016/j.gene.2008.09.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 06/29/2008] [Accepted: 09/01/2008] [Indexed: 01/24/2023]
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Autocrine motility factor stimulates the invasiveness of malignant cells as well as up-regulation of matrix metalloproteinase-3 expression via a MAPK pathway. FEBS Lett 2008; 582:1877-82. [PMID: 18485900 DOI: 10.1016/j.febslet.2008.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Revised: 04/16/2008] [Accepted: 05/06/2008] [Indexed: 10/22/2022]
Abstract
The autocrine motility factor (AMF) is a multifunctional protein that is involved in tumor progression including enhanced invasiveness via induction of matrix metalloproteinase-3 (MMP3). The increase in MMP3 was found in an AMF-high production tumor cell line, and c-Jun, c-Fos and mitogen-activated protein kinases (MAPKs) were also highly phosphorylated compared with the parent line. AMF stimulation induced the rapid phosphorylation of the cellular MAPK cascade and MMP3 secretion, which was blocked using a specific MAPK inhibitor. Results of this study suggest that AMF stimulation stimulates MMP3 expression via a MAPK signaling pathway.
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Wang YH, Chiu WT, Wang YK, Wu CC, Chen TL, Teng CF, Chang WT, Chang HC, Tang MJ. Deregulation of AP-1 proteins in collagen gel-induced epithelial cell apoptosis mediated by low substratum rigidity. J Biol Chem 2006; 282:752-63. [PMID: 17085440 DOI: 10.1074/jbc.m604801200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, we established that collagen gel, but not collagen gel coating, induced apoptosis exclusively in epithelial cell lines, which indicated that low substratum rigidity might trigger cell apoptosis. To confirm this, we used collagen gels with different rigidities due to cross-linking or physical disruption of collagen fibrils caused by sonication. We found that collagen gel-induced apoptosis was inversely correlated with substratum rigidity. Low substratum rigidity collagen gel-induced apoptosis was neither prevented by Bcl-2 overexpression nor preceded by mitochondrial release of cytochrome c. This suggested that the mitochondrial pathway was not involved in low substratum rigidity-induced apoptosis. Low substratum rigidity activated c-Jun N-terminal kinase (JNK) within 4 h, but it also rapidly down-regulated c-Jun within 1 h and triggered persistent aberrant expression of c-Fos for at least 24 h. Either reduced c-Jun expression or c-Fos overexpression induced apoptosis in several epithelial cells. Inhibiting low substratum rigidity-induced JNK activation prevented aberrant c-Fos expression but only partially blocked low substratum rigidity-induced apoptosis. Taking these results together, we conclude that low substratum rigidity collagen gel induced apoptosis in epithelial cells and that deregulated AP-1 proteins mediated that apoptosis, at least in part.
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Affiliation(s)
- Yao-Hsien Wang
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
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Chmurzyńska A. The multigene family of fatty acid-binding proteins (FABPs): function, structure and polymorphism. J Appl Genet 2006; 47:39-48. [PMID: 16424607 DOI: 10.1007/bf03194597] [Citation(s) in RCA: 471] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Fatty acid-binding proteins (FABPs) are members of the superfamily of lipid-binding proteins (LBP). So far 9 different FABPs, with tissue-specific distribution, have been identified: L (liver), I (intestinal), H (muscle and heart), A (adipocyte), E (epidermal), Il (ileal), B (brain), M (myelin) and T (testis). The primary role of all the FABP family members is regulation of fatty acid uptake and intracellular transport. The structure of all FABPs is similar - the basic motif characterizing these proteins is beta-barrel, and a single ligand (e.g. a fatty acid, cholesterol, or retinoid) is bound in its internal water-filled cavity. Despite the wide variance in the protein sequence, the gene structure is identical. The FABP genes consist of 4 exons and 3 introns and a few of them are located in the same chromosomal region. For example, A-FABP, E-FABP and M-FABP create a gene cluster. Because of their physiological properties some FABP genes were tested in order to identify mutations altering lipid metabolism. Furthermore, the porcine A-FABP and H-FABP were studied as candidate genes with major effect on fatness traits.
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Affiliation(s)
- Agata Chmurzyńska
- Department of Animal Genetics and Breeding, August Cieszkowski Agricultural University of Poznan, Wolynska 33, Poznan 60-637, Poland
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Park CH, Lee JH, Yang CH. Curcumin Derivatives Inhibit the Formation of Jun-Fos-DNA Complex Independently of their Conserved Cysteine Residues. BMB Rep 2005; 38:474-80. [PMID: 16053715 DOI: 10.5483/bmbrep.2005.38.4.474] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Curcumin, a major active component of turmeric, has been identified as an inhibitor of the transcriptional activity of activator protein-1 (AP-1). Recently, it was also found that curcumin and synthetic curcumin derivatives can inhibit the binding of Jun-Fos, which are the members of the AP-1 family, to DNA. However, the mechanism of this inhibition by curcumin and its derivatives was not disclosed. Since the binding of Jun-Fos dimer to DNA can be modulated by redox control involving conserved cysteine residues, we studied whether curcumin and its derivatives inhibit Jun-Fos DNA binding activity via these residues. However, the inhibitory mechanism of curcumin and its derivatives, unlike that of other Jun-Fos inhibitors, was found to be independent of these conserved cysteine residues. In addition, we investigated whether curcumin derivatives can inhibit AP-1 transcriptional activity in vivo using a luciferase assay. We found that, among the curcumin derivatives examined, only inhibitors shown to inhibit the binding of Jun-Fos to DNA by Electrophoretic Mobility Shift Assay (EMSA) inhibited AP-1 transcriptional activity in vivo. Moreover, RT-PCR revealed that curcumin derivatives, like curcumin, downregulated c-jun mRNA in JB6 cells. These results suggest that the suppression of the formation of DNA-Jun-Fos complex is the main cause of reduced AP-1 transcriptional activity by curcuminoids, and that EMSA is a suitable tool for identifying inhibitors of transcriptional activation.
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Affiliation(s)
- Chi Hoon Park
- Division of Chemistry and Molecular Engineering, Seoul National University, Seoul 151-742, Korea,
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Tchoukalova YD, Sarr MG, Jensen MD. Measuring committed preadipocytes in human adipose tissue from severely obese patients by using adipocyte fatty acid binding protein. Am J Physiol Regul Integr Comp Physiol 2004; 287:R1132-40. [PMID: 15284082 DOI: 10.1152/ajpregu.00337.2004] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To understand the significance of the reported depot differences in preadipocyte dynamics, we developed a procedure to identify committed preadipocytes in the stromovascular fraction of fresh human adipose tissue. We documented that adipocyte fatty acid binding protein (aP2) is expressed in human preadipocyte clones capable of replication, indicating that can be used as a marker of committed preadipocytes. Because aP2 expression can be induced in macrophages, stromovascular cells were also stained for the macrophage marker CD68. We found aP2+CD68- cells (designated as committed preadipocytes) that did not have lipid droplets (true preadipocytes) and that did have lipid droplets < 6.5 microm in diameter (very immature adipocytes). Adipose tissue from subcutaneous, omental, and mesenteric depots was obtained from nine patients undergoing bariatric surgery for measurement of stromovascular cell number, the number of committed preadipocytes (aP2+CD68-), aP2+ macrophages (aP2+CD68+), and aP2- macrophages (aP2-CD68+). The number of committed preadipocytes did not differ significantly between depots but varied >20-fold among individuals. Total cell number, stromovascular cell number, and the number of aP2- macrophages was less (P < 0.05) in subcutaneous than in omental fat (means +/- SE, in millions: subcutaneous, 2.3 +/- 0.3, 1.4 +/- 0.3, and 0.17 +/- 0.08; and omental, 4.8 +/- 0.7, 3.8 +/- 0.5, and 0.34 +/- 0.06); mesenteric depot was intermediate. These data indicate that the cellular composition of adipose tissue varies between depots and between individuals. The ability to quantify committed preadipocytes in fresh adipose tissue should facilitate study of adipose tissue biology.
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Cho KJ, Moon HE, Moini H, Packer L, Yoon DY, Chung AS. Alpha-lipoic acid inhibits adipocyte differentiation by regulating pro-adipogenic transcription factors via mitogen-activated protein kinase pathways. J Biol Chem 2003; 278:34823-33. [PMID: 12837769 DOI: 10.1074/jbc.m210747200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Obesity is associated with a number of pathological disorders such as non-insulin-dependent diabetes, hypertension, hyperlipidemia, and cardiovascular diseases. alpha-Lipoic acid (LA) has been demonstrated to activate the insulin signaling pathway and to exert insulin-like actions in adipose and muscle cells. Based on this similarity LA is expected to promote adipogenesis in pre-adipocytes. Here, however, we report that LA inhibited differentiation of 3T3-L1 pre-adipocytes induced by a hormonal mixture or troglitazone. Northern blot analysis of cells demonstrated that this inhibition was accompanied with attenuated expression of adipocyte-specific fatty acid-binding protein and lipoprotein lipase. Electrophoretic mobility shift assay and Western blot analysis of cells demonstrated that LA modulates transcriptional activity and/or expression of a set of anti- or pro-adipogenic transcription factors. LA treatment of 3T3-L1 pre-adipocytes also resulted in prolonged activation of major mitogen-activated protein kinase signaling pathways but showed little or no effect on the activity of the insulin receptor/Akt signaling pathway. These findings suggest that LA inhibits insulin or the hormonal mixture-induced differentiation of 3T3-L1 pre-adipocytes by modulating activity and/or expression of pro- or anti-adipogenic transcription factors mainly through activating the MAPK pathways.
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Affiliation(s)
- Kyung-Joo Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea
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Felmer R, Horvat S, Clinton M, Clark AJ. Overexpression of Raidd cDNA inhibits differentiation of mouse preadipocytes. Cell Prolif 2003; 36:45-54. [PMID: 12558660 PMCID: PMC6495696 DOI: 10.1046/j.1365-2184.2003.00253.x] [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: 11/20/2022] Open
Abstract
RAIDD (RIP-associated ICH-1 homologous protein with a death domain) is an adaptor molecule that mediates the action of cysteine proteases involved in apoptosis. To study the possibility of a novel system of cell ablation mediated by RAIDD, a preadipocyte cell line (3T3L1) was stably transfected with a plasmid containing the murine Raidd cDNA under the control of the adipocyte specific promoter aP2. Instead of the expected apoptosis, a blockage to differentiation upon hormonal induction was observed as judged by an absence of lipid accumulation, a lack of expression of adipocyte-specific genes and a fibroblastic appearance. Proliferation rate of Raidd-transfected clones remained unaffected. Overexpression of Raidd cDNA in 3T3L1 cell therefore inhibited differentiation, suggesting that Raidd plays a role in controlling differentiation of mouse preadipocytes and, perhaps, in other cell types, in addition to its established role in apoptosis.
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Affiliation(s)
- R. Felmer
- Division of Gene Expression and Development, Roslin Institute, Roslin, Midlothian, Scotland, UK and
- The present address of R. Felmer is: National Institute for Agricultural Research (INIA), CRI‐Carillanca, PO‐Box 58‐D, Temuco, Chile
| | - S. Horvat
- Division of Gene Expression and Development, Roslin Institute, Roslin, Midlothian, Scotland, UK and
- University of Ljubljana, Biotechnical Faculty, Zootechnical Departement, Domzale, Slovenia
| | - M. Clinton
- Division of Gene Expression and Development, Roslin Institute, Roslin, Midlothian, Scotland, UK and
| | - A. J. Clark
- Division of Gene Expression and Development, Roslin Institute, Roslin, Midlothian, Scotland, UK and
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Buckmaster A, Nobes CD, Edwards SN, Tolkovsky AM. Nerve Growth Factor is Required for Induction of c-Fos Immunoreactivity by Serum, Depolarization, Cyclic AMP or Trauma in Cultured Rat Sympathetic Neurons. Eur J Neurosci 2002; 3:698-707. [PMID: 12106477 DOI: 10.1111/j.1460-9568.1991.tb00855.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Nerve growth factor (NGF) induces transient Fos-immunoreactivity (Fos-IR) independently of any other factor, both in newly isolated rat sympathetic neurons and in established cultures after NGF deprivation. The same proportion of neurons that express Fos-IR in response to NGF also survive. In addition to direct stimulation of Fos-IR expression, the presence or recent exposure to NGF is required to obtain Fos-IR expression by other stimuli. In newly isolated neurons no Fos-IR is detected in response to stimulation by serum alone and a response to depolarization or cyclic AMP is obtained only if neurons are stimulated within a short period after ganglion excision. In established cultures none of these stimuli, nor the trauma of cutting neurites or spiking cell bodies with a microinjection needle induce Fos-IR unless NGF is present or had been removed for <8 - 16 h. The lack of response is not due to a general decrease in the rate of protein or RNA synthesis. These findings show that in regenerating sympathetic neurons NGF induces c-Fos and suggest that NGF may activate a master trigger that is required for c-Fos expression to be induced by other stimuli.
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Affiliation(s)
- A Buckmaster
- Department of Human Anatomy, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
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Ro HS, Kim SW, Wu D, Webber C, Nicholson TE. Gene structure and expression of the mouse adipocyte enhancer-binding protein. Gene 2001; 280:123-33. [PMID: 11738825 DOI: 10.1016/s0378-1119(01)00771-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The adipocyte enhancer-binding protein (AEBP1) is a transcriptional repressor with carboxypeptidase activity. AEBP1 expression is down-regulated during adipogenesis. Aortic carboxypeptidase-like protein (ACLP) is a non-nuclear isoform of AEBP1 that has an N-terminal extension of 380 amino acids. ACLP expression is up-regulated during vascular smooth muscle cell differentiation. To gain insight into the regulation of AEBP1 isoform expression, we have determined the structural organization of the mouse AEBP1 gene. This gene extends over 10 kb, has 21 exons, and gives rise to two mRNAs (AEBP1 and ACLP). The 9th intron is retained in the mature AEBP1 transcript. Thus, ACLP encodes an additional 380 amino acids N-terminal to the first ATG codon of AEBP1 which is located in exon 10. RT-PCR experiments showed that both transcripts are expressed ubiquitously in all mouse tissues examined, while Western blot analysis suggested that expression is translationally regulated. Our results provide evidence that two isoforms of AEBP1 with very different functions are produced by an alternative splicing mechanism. This represents a new example of regulation of subcellular localization by protein truncation.
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Affiliation(s)
- H S Ro
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Sir Charles Tupper Medical Building, Dalhousie University, Halifax, Nova Scotia, B3H 4H7, Canada.
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Abstract
The major transcriptional factors involved in the adipogenic process include proteins belonging to the CCAAT/enhancer binding protein family, peroxisome proliferator-activated receptor gamma, and adipocyte determination and differentiation dependent factor 1, also known as sterol regulatory element-binding protein 1. This process has been characterized with the aid of cell lines that represent various stages in the path of adipocyte commitment, ranging from pluripotent mesodermal fibroblasts to preadipocytes. Molecular analyses have led to a cascade model for adipogenesis based on timed expression of CCAAT/enhancer-binding proteins and peroxisome proliferator-activated receptor gamma. Gene targeting and transgenic-mouse technologies, which allow the manipulation of endogenous genes for these transcription factors, have also contributed to the understanding of adipogenesis. This review aims to integrate this information to gain an understanding of the transcriptional regulation of fat cell formation.
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Affiliation(s)
- S M Rangwala
- Departments of Medicine and Genetics and The Penn Diabetes Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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Sabatakos G, Sims NA, Chen J, Aoki K, Kelz MB, Amling M, Bouali Y, Mukhopadhyay K, Ford K, Nestler EJ, Baron R. Overexpression of DeltaFosB transcription factor(s) increases bone formation and inhibits adipogenesis. Nat Med 2000; 6:985-90. [PMID: 10973317 DOI: 10.1038/79683] [Citation(s) in RCA: 293] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Members of the AP-1 family of transcription factors participate in the regulation of bone cell proliferation and differentiation. We report here a potent AP-1-related regulator of osteoblast function: DeltaFosB, a naturally occurring truncated form of FosB that arises from alternative splicing of the fosB transcript and is expressed in osteoblasts. Overexpression of DeltaFosB in transgenic mice leads to increased bone formation throughout the skeleton and a continuous post-developmental increase in bone mass, leading to osteosclerosis. In contrast, DeltaFosB inhibits adipogenesis both in vivo and in vitro, and downregulates the expression of early markers of adipocyte differentiation. Because osteoblasts and adipocytes are thought to share a common precursor, it is concluded that DeltaFosB transcriptionally regulates osteoblastogenesis, possibly at the expense of adipogenesis.
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Affiliation(s)
- G Sabatakos
- Departments of Cell Biology and Orthopaedics, Yale University School of Medicine SHM IE-55, 333 Cedar St, New Haven, Connecticut 06520-8044, USA
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He GP, Kim S, Ro HS. Cloning and characterization of a novel zinc finger transcriptional repressor. A direct role of the zinc finger motif in repression. J Biol Chem 1999; 274:14678-84. [PMID: 10329662 DOI: 10.1074/jbc.274.21.14678] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have identified a novel transcriptional repressor, AEBP2, that binds to a regulatory sequence (termed AE-1) located in the proximal promoter region of the aP2 gene that encodes the adipose fatty acid-binding protein. Sequence analysis of AEBP2 cDNA revealed that it encodes a protein containing three Gli-Krüppel (Cys2-His2)-type zinc fingers. Northern blot analysis revealed two transcripts (4.5 and 3.5 kilobases) which were ubiquitously expressed in every mouse tissue examined. In co-transfection assays, AEBP2 repressed transcription from the homologous aP2 promoter containing multiple copies of the AE-1 sequence. Moreover, a chimeric construct encoding a fusion AEBP2 protein with the Gal4 DNA-binding domain was able to repress the transcriptional activity of a heterologous promoter containing the Gal4-binding sequence. The transcriptional repression function of AEBP2 was completely abolished when one of the conserved histidine residues and a flanking serine residue in the middle zinc finger were replaced with an arginine residue. The defective transcriptional repression function of the mutant derivative was due neither to lack of expression nor to a failure to localize to the nucleus. Moreover, both the wild-type and mutant derivative of either the histidine-tagged recombinant AEBP2 proteins or the in vitro translated Gal4-AEBP2 fusion proteins were equally able to bind to the target DNA. These results suggest that a portion of the zinc finger structure may play a direct role in transcriptional repression function, but not in DNA binding.
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Affiliation(s)
- G P He
- Department of Biochemistry, Faculty of Medicine, Sir Charles Tupper Medical Building, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada
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Harbitz I, Langset M, Ege AG, Høyheim B, Davies W. The porcine hormone-sensitive lipase gene: sequence, structure, polymorphisms and linkage mapping. Anim Genet 1999; 30:10-5. [PMID: 10050278 DOI: 10.1046/j.1365-2052.1999.00412.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The porcine hormone-sensitive lipase gene and its cDNA have been isolated and sequenced. Several putative regulatory sequences have been detected in the promotor region. The deduced amino acid sequence is 85% identical to the corresponding human, mouse and rat sequence. A search for polymorphisms revealed one intronic and one exonic polymorphism, the latter resulting in a conservative amino acid substitution. Linkage mapping located the LIPE gene close to the calcium release channel (CRC) locus on chromosome 6.
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Affiliation(s)
- I Harbitz
- Department of Biochemistry, Physiology and Nutrition, Norwegian School of Veterinary Science, Oslo, Norway
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Ho IC, Kim JH, Rooney JW, Spiegelman BM, Glimcher LH. A potential role for the nuclear factor of activated T cells family of transcriptional regulatory proteins in adipogenesis. Proc Natl Acad Sci U S A 1998; 95:15537-41. [PMID: 9861004 PMCID: PMC28078 DOI: 10.1073/pnas.95.26.15537] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/1998] [Indexed: 01/15/2023] Open
Abstract
NFAT (nuclear factor of activated T cells) is a family of transcription factors implicated in the control of cytokine and early immune response gene expression. Recent studies have pointed to a role for NFAT proteins in gene regulation outside of the immune system. Herein we demonstrate that NFAT proteins are present in 3T3-L1 adipocytes and, upon fat cell differentiation, bind to and transactivate the promoter of the adipocyte-specific gene aP2. Further, fat cell differentiation is inhibited by cyclosporin A, a drug shown to prevent NFAT nuclear localization and hence function. Thus, these data suggest a role for NFAT transcription factors in the regulation of the aP2 gene and in the process of adipocyte differentiation.
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Affiliation(s)
- I C Ho
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, 651 Huntington Avenue, Boston, MA 02115, USA
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Herdegen T, Leah JD. Inducible and constitutive transcription factors in the mammalian nervous system: control of gene expression by Jun, Fos and Krox, and CREB/ATF proteins. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 1998; 28:370-490. [PMID: 9858769 DOI: 10.1016/s0165-0173(98)00018-6] [Citation(s) in RCA: 1049] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This article reviews findings up to the end of 1997 about the inducible transcription factors (ITFs) c-Jun, JunB, JunD, c-Fos, FosB, Fra-1, Fra-2, Krox-20 (Egr-2) and Krox-24 (NGFI-A, Egr-1, Zif268); and the constitutive transcription factors (CTFs) CREB, CREM, ATF-2 and SRF as they pertain to gene expression in the mammalian nervous system. In the first part we consider basic facts about the expression and activity of these transcription factors: the organization of the encoding genes and their promoters, the second messenger cascades converging on their regulatory promoter sites, the control of their transcription, the binding to dimeric partners and to specific DNA sequences, their trans-activation potential, and their posttranslational modifications. In the second part we describe the expression and possible roles of these transcription factors in neural tissue: in the quiescent brain, during pre- and postnatal development, following sensory stimulation, nerve transection (axotomy), neurodegeneration and apoptosis, hypoxia-ischemia, generalized and limbic seizures, long-term potentiation and learning, drug dependence and withdrawal, and following stimulation by neurotransmitters, hormones and neurotrophins. We also describe their expression and possible roles in glial cells. Finally, we discuss the relevance of their expression for nervous system functioning under normal and patho-physiological conditions.
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Affiliation(s)
- T Herdegen
- Institute of Pharmacology, University of Kiel, Hospitalstrasse 4, 24105, Kiel,
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Moitra J, Mason MM, Olive M, Krylov D, Gavrilova O, Marcus-Samuels B, Feigenbaum L, Lee E, Aoyama T, Eckhaus M, Reitman ML, Vinson C. Life without white fat: a transgenic mouse. Genes Dev 1998; 12:3168-81. [PMID: 9784492 PMCID: PMC317213 DOI: 10.1101/gad.12.20.3168] [Citation(s) in RCA: 562] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We have generated a transgenic mouse with no white fat tissue throughout life. These mice express a dominant-negative protein, termed A-ZIP/F, under the control of the adipose-specific aP2 enhancer/promoter. This protein prevents the DNA binding of B-ZIP transcription factors of both the C/EBP and Jun families. The transgenic mice (named A-ZIP/F-1) have no white adipose tissue and dramatically reduced amounts of brown adipose tissue, which is inactive. They are initially growth delayed, but by week 12, surpass their littermates in weight. The mice eat, drink, and urinate copiously, have decreased fecundity, premature death, and frequently die after anesthesia. The physiological consequences of having no white fat tissue are profound. The liver is engorged with lipid, and the internal organs are enlarged. The mice are diabetic, with reduced leptin (20-fold) and elevated serum glucose (3-fold), insulin (50- to 400-fold), free fatty acids (2-fold), and triglycerides (3- to 5-fold). The A-ZIP/F-1 phenotype suggests a mouse model for the human disease lipoatrophic diabetes (Seip-Berardinelli syndrome), indicating that the lack of fat can cause diabetes. The myriad of consequences of having no fat throughout development can be addressed with this model.
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Affiliation(s)
- J Moitra
- Laboratory of Biochemistry, National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland 20892 USA
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Sul HS, Smas CM, Wang D, Chen L. Regulation of fat synthesis and adipose differentiation. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1998; 60:317-45. [PMID: 9594578 DOI: 10.1016/s0079-6603(08)60896-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adipocytes have highly specialized function of accumulating fat as stored energy that can be used during periods of food deprivation. The process of fat synthesis and development of adipose tissue are under hormonal and nutritional control. This review first describes transcription of the two critical enzymes involved in fat synthesis, fatty acid synthase and mitochondrial glycerol-3-phosphate acyltransferase, is decreased to an undetectable level during fasting. Food intake, especially a high carbohydrate, fat-free diet, subsequent to fasting causes dramatic increase in transcription of these genes. Insulin secretion is increased during feeding, having a positive effect, whereas cAMP, which mediates the effect of glucagon which increases during fasting, has a negative effect on transcription of these genes. Using adipocytes in culture and in transgenic mice that express liciferase driven by the fatty acid synthase promoter, cis-acting and trans-acting factors that may mediate the transcriptional regulation were examined. Upstream stimulatory factors (USFs) that bind to -65 E-box are required for insulin-mediated transcriptional activation of the fatty acid synthase gene. This review next describes how pref-1 is a novel inhibitor of adipose differentiation and is a plasma membrane protein containing six EGF-repeats in the extracellular domain. Pref-1 is highly expressed in 3T3-L1 preadipocytes, but is not detectable in mature fat cells. Down regulation of pref-1 is required for adipose differentiation, and constitutive expression of pref-1 inhibits adipogenesis. Moreover, the ectodomain of pref-1 is cleaved to generate a biologically active 50 kDa soluble form. There are four major forms of membrane pref-1 resulting from alternate splicing, but two of the forms with a larger deletion do not produce biologically active soluble form, indicating that alternate splicing determines the range of action, juxtacrine or paracrine, of the pref-1.
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Affiliation(s)
- H S Sul
- Department of Nutritional Sciences, University of California, Berkeley 94720-3104, USA
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Coe NR, Bernlohr DA. Physiological properties and functions of intracellular fatty acid-binding proteins. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1391:287-306. [PMID: 9555061 DOI: 10.1016/s0005-2760(97)00205-1] [Citation(s) in RCA: 236] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- N R Coe
- Department of Biochemistry, University of Minnesota, 1479 Gorter Ave, St. Paul, MN 55108, USA
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Ghee M, Baker H, Miller JC, Ziff EB. AP-1, CREB and CBP transcription factors differentially regulate the tyrosine hydroxylase gene. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 55:101-14. [PMID: 9645965 DOI: 10.1016/s0169-328x(97)00370-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The tyrosine hydroxylase (TH) gene encodes the rate-limiting enzyme in the biosynthesis of catecholamines. We have investigated the roles of two elements of the TH promoter, the TH-'Fat Specific Element' (TH-FSE) which binds the Fos-Jun complex, and the cAMP Response Element (CRE), which binds CREB and the co-activator protein, CREB Binding Protein (CBP) in regulating TH gene transcription. In PC12 cells, the TH-FSE was required for induction by NGF while the CRE was required for induction by cAMP. We show that both elements can function independently and contribute strongly to TH promoter basal activity in PC12 cells. We employed transient expression in the F9 teratocarcinoma cell line to vary experimentally the levels of the nuclear regulators implicated in TH control by the PC12 studies. In F9 cells, the TH promoter was strongly activated by Fos and Jun, and by PKA-stimulated CREB protein. In F9 and NIH3T3 cells, CBP, a co-activator which targets Fos-Jun and PKA-stimulated CREB, also induced the TH promoter. Immunohistochemical studies in rat brain regions enriched in dopaminergic neurons, including the midbrain and olfactory bulb (OB), suggest that Fos-Jun and CREB make differential contributions to TH gene activity in different tissues. Whereas changes in Fos protein levels parallel decreases in TH protein upon olfactory deprivation, CBP levels remain unchanged. This suggests that CRE-associated factors, including CBP, are not major regulators in the OB. In contrast, the presence of CREB and the absence of Fos immunoreactivity in midbrain dopaminergic cells suggests that the CRE is the primary regulator in this region.
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Affiliation(s)
- M Ghee
- Howard Hughes Medical Institute, New York University Medical Center, NY 10016, USA
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Bey L, Etienne J, Tse C, Brault D, Noé L, Raisonnier A, Arnault F, Hamilton MT, Galibert F. Cloning, sequencing and structural analysis of 976 base pairs of the promoter sequence for the rat lipoprotein lipase gene. Comparison with the mouse and human sequences. Gene X 1998; 209:31-8. [PMID: 9524212 DOI: 10.1016/s0378-1119(98)00003-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We cloned and sequenced the -976bp promoter of the rat lipoprotein lipase LPL gene. The sequence was compared with the mouse and human sequences. The homology between the rat and mouse LPL nucleotide sequences was not quite as strong in the promoter sequence as in the coding sequence. Among the 976nt promoter there were 118 divergences, i.e. 11.8%, compared to only 5.6% for the LPL coding region. However, within the 200nt immediately 5' to the transcriptional start site (proximal promoter), the divergence was only 4%. New potential cis-elements (such as CACCC, GATA, GC and GA boxes, IRS, Krox, MEF 2, E-box, CCArGG and 1/2 VDRE) were identified in the rat, mouse or human LPL gene.
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Affiliation(s)
- L Bey
- Biochimie et Biologie moléculaire, Faculté de Médecine St Antoine-Tenon, 75012, Paris, France
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