1
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Vasudevan NP, Soni DK, Moffett JR, Krishnan JKS, Appu AP, Ghoshal S, Arun P, Denu JM, Flagg TP, Biswas R, Namboodiri AM. Acss2 Deletion Reveals Functional Versatility via Tissue-Specific Roles in Transcriptional Regulation. Int J Mol Sci 2023; 24:3673. [PMID: 36835088 PMCID: PMC9964712 DOI: 10.3390/ijms24043673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/30/2023] [Accepted: 02/06/2023] [Indexed: 02/16/2023] Open
Abstract
The coordination of cellular biological processes is regulated in part via metabolic enzymes acting to match cellular metabolism to current conditions. The acetate activating enzyme, acyl-coenzyme A synthetase short-chain family member 2 (Acss2), has long been considered to have a predominantly lipogenic function. More recent evidence suggests that this enzyme has regulatory functions in addition to its role in providing acetyl-CoA for lipid synthesis. We used Acss2 knockout mice (Acss2-/-) to further investigate the roles this enzyme plays in three physiologically distinct organ systems that make extensive use of lipid synthesis and storage, including the liver, brain, and adipose tissue. We examined the resulting transcriptomic changes resulting from Acss2 deletion and assessed these changes in relation to fatty acid constitution. We find that loss of Acss2 leads to dysregulation of numerous canonical signaling pathways, upstream transcriptional regulatory molecules, cellular processes, and biological functions, which were distinct in the liver, brain, and mesenteric adipose tissues. The detected organ-specific transcriptional regulatory patterns reflect the complementary functional roles of these organ systems within the context of systemic physiology. While alterations in transcriptional states were evident, the loss of Acss2 resulted in few changes in fatty acid constitution in all three organ systems. Overall, we demonstrate that Acss2 loss institutes organ-specific transcriptional regulatory patterns reflecting the complementary functional roles of these organ systems. Collectively, these findings provide further confirmation that Acss2 regulates key transcription factors and pathways under well-fed, non-stressed conditions and acts as a transcriptional regulatory enzyme.
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Affiliation(s)
- Narayanan Puthillathu Vasudevan
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Dharmendra K. Soni
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - John R. Moffett
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Jishnu K. S. Krishnan
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Abhilash P. Appu
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Sarani Ghoshal
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Peethambaran Arun
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - John M. Denu
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Thomas P. Flagg
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Roopa Biswas
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Aryan M. Namboodiri
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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2
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Ling R, Chen G, Tang X, Liu N, Zhou Y, Chen D. Acetyl-CoA synthetase 2(ACSS2): a review with a focus on metabolism and tumor development. Discov Oncol 2022; 13:58. [PMID: 35798917 PMCID: PMC9263018 DOI: 10.1007/s12672-022-00521-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 07/01/2022] [Indexed: 02/08/2023] Open
Abstract
Acetyl-CoA synthetase 2 (ACSS2), an important member of the acetyl-CoA synthetase (ACSS) family, can catalyze the conversion of acetate to acetyl coenzyme A (acetyl-CoA). Currently, acetyl-CoA is considered an important intermediate metabolite in the metabolism of energy substrates. In addition, nutrients converge through acetyl-CoA into a common metabolic pathway, the tricarboxylic acid cycle and oxidative phosphorylation. Not only does ACSS2 play a crucial role in material energy metabolism, it is also involved in the regulation of various acetylation processes, such as regulation of histone and transcription factor acetylation. ACSS2-mediated regulation of acetylation is related to substance metabolism and tumorigenesis. In mammalian cells, ACSS2 utilizes intracellular acetate to synthesize acetyl-CoA, a step in the process of DNA and histone acetylation. In addition, studies in tumors have shown that cancer cells adapt to the growth conditions in the tumor microenvironment (TME) by activating or increasing the expression level of ACSS2 under metabolic stress. Therefore, this review mainly outlines the role of ACSS2 in substance metabolism and tumors and provides insights useful for investigating ACSS2 as a therapeutic target.
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Affiliation(s)
- Rui Ling
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, China.
| | - Gong Chen
- Department of Thoracic Surgery, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Xiang Tang
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Na Liu
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Yuepeng Zhou
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Deyu Chen
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, China.
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3
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Jia Z, Chen X, Chen J, Zhang L, Oprescu SN, Luo N, Xiong Y, Yue F, Kuang S. ACSS3 in brown fat drives propionate catabolism and its deficiency leads to autophagy and systemic metabolic dysfunction. Clin Transl Med 2022; 12:e665. [PMID: 35184387 PMCID: PMC8858619 DOI: 10.1002/ctm2.665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/11/2021] [Accepted: 11/17/2021] [Indexed: 11/22/2022] Open
Abstract
Propionate is a gut microbial metabolite that has been reported to have controversial effects on metabolic health. Here we show that propionate is activated by acyl‐CoA synthetase short‐chain family member 3 (ACSS3), located on the mitochondrial inner membrane in brown adipocytes. Knockout of Acss3 gene (Acss3–/–) in mice reduces brown adipose tissue (BAT) mass but increases white adipose tissue (WAT) mass, leading to glucose intolerance and insulin resistance that are exacerbated by high‐fat diet (HFD). Intriguingly, Acss3–/– or HFD feeding significantly elevates propionate levels in BAT and serum, and propionate supplementation induces autophagy in cultured brown and white adipocytes. The elevated levels of propionate in Acss3–/– mice similarly drive adipocyte autophagy, and pharmacological inhibition of autophagy using hydroxychloroquine ameliorates obesity, hepatic steatosis and insulin resistance of the Acss3–/– mice. These results establish ACSS3 as the key enzyme for propionate metabolism and demonstrate that accumulation of propionate promotes obesity and Type 2 diabetes through triggering adipocyte autophagy.
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Affiliation(s)
- Zhihao Jia
- Department of Animal Sciences Purdue University West Lafayette Indiana
| | - Xiyue Chen
- Department of Animal Sciences Purdue University West Lafayette Indiana
| | - Jingjuan Chen
- Department of Animal Sciences Purdue University West Lafayette Indiana
| | - Lijia Zhang
- Department of Animal Sciences Purdue University West Lafayette Indiana
| | - Stephanie N. Oprescu
- Department of Animal Sciences Purdue University West Lafayette Indiana
- Department of Biological Sciences Purdue University West Lafayette Indiana
| | - Nanjian Luo
- Department of Animal Sciences Purdue University West Lafayette Indiana
| | - Yan Xiong
- Department of Animal Sciences Purdue University West Lafayette Indiana
| | - Feng Yue
- Department of Animal Sciences Purdue University West Lafayette Indiana
| | - Shihuan Kuang
- Department of Animal Sciences Purdue University West Lafayette Indiana
- Center for Cancer Research Purdue University West Lafayette Indiana
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4
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John S, K G G, Krishna AP, Mishra R. Neurotherapeutic implications of sense and respond strategies generated by astrocytes and astrocytic tumours to combat pH mechanical stress. Neuropathol Appl Neurobiol 2021; 48:e12774. [PMID: 34811795 PMCID: PMC9300154 DOI: 10.1111/nan.12774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 09/24/2021] [Accepted: 11/14/2021] [Indexed: 02/04/2023]
Abstract
Aims Astrocytes adapt to acute acid stress. Intriguingly, cancer cells with astrocytic differentiation thrive even better in an acidic microenvironment. How changes in extracellular pH (pHe) are sensed and measured by the cell surface assemblies that first intercept the acid stress, and how this information is relayed downstream for an appropriate survival response remains largely uncharacterized. Methods In vitro cell‐based studies were combined with an in vivo animal model to delineate the machinery involved in pH microenvironment sensing and generation of mechanoadaptive responses in normal and neoplastic astrocytes. The data was further validated on patient samples from acidosis driven ischaemia and astrocytic tumour tissues. Results We demonstrate that low pHe is perceived and interpreted by cells as mechanical stress. GM3 acts as a lipid‐based pH sensor, and in low pHe, its highly protonated state generates plasma membrane deformation stress which activates the IRE1‐sXBP1‐SREBP2‐ACSS2 response axis for cholesterol biosynthesis and surface trafficking. Enhanced surface cholesterol provides mechanical tenacity and prevents acid‐mediated membrane hydrolysis, which would otherwise result in cell leakage and death. Conclusions In summary, activating these lipids or the associated downstream machinery in acidosis‐related neurodegeneration may prevent disease progression, while specifically suppressing this key mechanical ‘sense‐respond’ axis should effectively target astrocytic tumour growth.
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Affiliation(s)
- Sebastian John
- Brain and Cerebrovascular Mechanobiology Research, Laboratory of Translational Mechanobiology, Department of Neurobiology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.,Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - Gayathri K G
- Brain and Cerebrovascular Mechanobiology Research, Laboratory of Translational Mechanobiology, Department of Neurobiology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.,Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - Aswani P Krishna
- Brain and Cerebrovascular Mechanobiology Research, Laboratory of Translational Mechanobiology, Department of Neurobiology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Rashmi Mishra
- Brain and Cerebrovascular Mechanobiology Research, Laboratory of Translational Mechanobiology, Department of Neurobiology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.,Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
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5
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Park G, Jung S, Wellen KE, Jang C. The interaction between the gut microbiota and dietary carbohydrates in nonalcoholic fatty liver disease. Exp Mol Med 2021; 53:809-822. [PMID: 34017059 PMCID: PMC8178320 DOI: 10.1038/s12276-021-00614-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/24/2021] [Indexed: 02/04/2023] Open
Abstract
Imbalance between fat production and consumption causes various metabolic disorders. Nonalcoholic fatty liver disease (NAFLD), one such pathology, is characterized by abnormally increased fat synthesis and subsequent fat accumulation in hepatocytes1,2. While often comorbid with obesity and insulin resistance, this disease can also be found in lean individuals, suggesting specific metabolic dysfunction2. NAFLD has become one of the most prevalent liver diseases in adults worldwide, but its incidence in both children and adolescents has also markedly increased in developed nations3,4. Progression of this disease into nonalcoholic steatohepatitis (NASH), cirrhosis, liver failure, and hepatocellular carcinoma in combination with its widespread incidence thus makes NAFLD and its related pathologies a significant public health concern. Here, we review our understanding of the roles of dietary carbohydrates (glucose, fructose, and fibers) and the gut microbiota, which provides essential carbon sources for hepatic fat synthesis during the development of NAFLD.
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Affiliation(s)
- Grace Park
- Department of Biological Chemistry, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA
| | - Sunhee Jung
- Department of Biological Chemistry, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA
| | - Kathryn E Wellen
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Cholsoon Jang
- Department of Biological Chemistry, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA.
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6
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Acetyl-CoA Metabolism and Histone Acetylation in the Regulation of Aging and Lifespan. Antioxidants (Basel) 2021; 10:antiox10040572. [PMID: 33917812 PMCID: PMC8068152 DOI: 10.3390/antiox10040572] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/31/2021] [Accepted: 04/02/2021] [Indexed: 12/16/2022] Open
Abstract
Acetyl-CoA is a metabolite at the crossroads of central metabolism and the substrate of histone acetyltransferases regulating gene expression. In many tissues fasting or lifespan extending calorie restriction (CR) decreases glucose-derived metabolic flux through ATP-citrate lyase (ACLY) to reduce cytoplasmic acetyl-CoA levels to decrease activity of the p300 histone acetyltransferase (HAT) stimulating pro-longevity autophagy. Because of this, compounds that decrease cytoplasmic acetyl-CoA have been described as CR mimetics. But few authors have highlighted the potential longevity promoting roles of nuclear acetyl-CoA. For example, increasing nuclear acetyl-CoA levels increases histone acetylation and administration of class I histone deacetylase (HDAC) inhibitors increases longevity through increased histone acetylation. Therefore, increased nuclear acetyl-CoA likely plays an important role in promoting longevity. Although cytoplasmic acetyl-CoA synthetase 2 (ACSS2) promotes aging by decreasing autophagy in some peripheral tissues, increased glial AMPK activity or neuronal differentiation can stimulate ACSS2 nuclear translocation and chromatin association. ACSS2 nuclear translocation can result in increased activity of CREB binding protein (CBP), p300/CBP-associated factor (PCAF), and other HATs to increase histone acetylation on the promoter of neuroprotective genes including transcription factor EB (TFEB) target genes resulting in increased lysosomal biogenesis and autophagy. Much of what is known regarding acetyl-CoA metabolism and aging has come from pioneering studies with yeast, fruit flies, and nematodes. These studies have identified evolutionary conserved roles for histone acetylation in promoting longevity. Future studies should focus on the role of nuclear acetyl-CoA and histone acetylation in the control of hypothalamic inflammation, an important driver of organismal aging.
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7
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Saraiva MA, de Carvalho NR, Martins IK, Macedo GE, Rodrigues NR, de Brum Vieira P, Prigol M, Gomes KK, Ziech CC, Franco JL, Posser T. Mancozeb impairs mitochondrial and bioenergetic activity in Drosophila melanogaster. Heliyon 2021; 7:e06007. [PMID: 33521363 PMCID: PMC7820929 DOI: 10.1016/j.heliyon.2021.e06007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/03/2020] [Accepted: 01/15/2021] [Indexed: 12/03/2022] Open
Abstract
Mancozeb (MZ) is a broad-spectrum fungicide used worldwide in several crops. Neurological disorders in humans and animals have been associated with exposure to this compound by mechanisms still not fully understood. Drosophila melanogaster represents a reliable model in toxicological studies, presenting genetic and biochemical similarities with mammals. In this study, D. melanogaster flies were exposed for 15 days to MZ through the food (5 and 10 mg/mL). After that period, the efficiency of mitochondrial respiration complexes and metabolic markers were analyzed and evaluated. Flies presented weight loss, lower glucose, trehalose, and glycogen levels, and augmented levels of triglycerides concerning control (non-treated group). Acetyl-CoA Synthetase (ACeCS-1) and Acyl-Coenzyme Synthetase (ACSL1) contents were unchanged by MZ treatment. Mitochondrial respiration of flies was targeted by MZ treatment, evidenced by a decrease in oxygen consumption and bioenergetics rate and inhibition in mitochondrial complexes I/II. These results suppose that an impairment in mitochondrial respiration jointly with reduced levels of energetic substrates might be a mechanism involved in MZ deleterious effects, possibly by the limitation of ATP's availability, necessary for essential cellular processes.
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Affiliation(s)
- Miriane Acosta Saraiva
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
| | - Nelson Rodrigues de Carvalho
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
- Instituto Federal Farroupilha, Campus Santo Ângelo, 98806700, RS, Brazil
| | - Illana Kemmerich Martins
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
| | - Giulianna Echeverria Macedo
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
| | - Nathane Rosa Rodrigues
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
| | - Patrícia de Brum Vieira
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
| | - Marina Prigol
- Laboratório de Avaliações Farmacológicas e Toxicológicas aplicadas às Moléculas Bioativas – Unipampa, Universidade Federal do Pampa - Campus Itaqui, Itaqui, RS, 97650-000, Brazil
| | - Karen Kich Gomes
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
| | - Cynthia Camila Ziech
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
| | - Jeferson Luis Franco
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
| | - Thais Posser
- Oxidative Stress and Cell Signaling Research Group, Universidade Federal do Pampa, Campus São Gabriel, 97300-000, São Gabriel, RS, Brazil
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Moffett JR, Puthillathu N, Vengilote R, Jaworski DM, Namboodiri AM. Acetate Revisited: A Key Biomolecule at the Nexus of Metabolism, Epigenetics and Oncogenesis-Part 1: Acetyl-CoA, Acetogenesis and Acyl-CoA Short-Chain Synthetases. Front Physiol 2020; 11:580167. [PMID: 33281616 PMCID: PMC7689297 DOI: 10.3389/fphys.2020.580167] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 09/23/2020] [Indexed: 12/19/2022] Open
Abstract
Acetate is a major end product of bacterial fermentation of fiber in the gut. Acetate, whether derived from the diet or from fermentation in the colon, has been implicated in a range of health benefits. Acetate is also generated in and released from various tissues including the intestine and liver, and is generated within all cells by deacetylation reactions. To be utilized, all acetate, regardless of the source, must be converted to acetyl coenzyme A (acetyl-CoA), which is carried out by enzymes known as acyl-CoA short-chain synthetases. Acyl-CoA short-chain synthetase-2 (ACSS2) is present in the cytosol and nuclei of many cell types, whereas ACSS1 is mitochondrial, with greatest expression in heart, skeletal muscle, and brown adipose tissue. In addition to acting to redistribute carbon systemically like a ketone body, acetate is becoming recognized as a cellular regulatory molecule with diverse functions beyond the formation of acetyl-CoA for energy derivation and lipogenesis. Acetate acts, in part, as a metabolic sensor linking nutrient balance and cellular stress responses with gene transcription and the regulation of protein function. ACSS2 is an important task-switching component of this sensory system wherein nutrient deprivation, hypoxia and other stressors shift ACSS2 from a lipogenic role in the cytoplasm to a regulatory role in the cell nucleus. Protein acetylation is a critical post-translational modification involved in regulating cell behavior, and alterations in protein acetylation status have been linked to multiple disease states, including cancer. Improving our fundamental understanding of the "acetylome" and how acetate is generated and utilized at the subcellular level in different cell types will provide much needed insight into normal and neoplastic cellular metabolism and the epigenetic regulation of phenotypic expression under different physiological stressors. This article is Part 1 of 2 - for Part 2 see doi: 10.3389/fphys.2020.580171.
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Affiliation(s)
- John R Moffett
- Department of Anatomy, Physiology and Genetics, and Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Narayanan Puthillathu
- Department of Anatomy, Physiology and Genetics, and Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Ranjini Vengilote
- Department of Anatomy, Physiology and Genetics, and Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Diane M Jaworski
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, VT, United States
| | - Aryan M Namboodiri
- Department of Anatomy, Physiology and Genetics, and Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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9
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Zhao S, Jang C, Liu J, Uehara K, Gilbert M, Izzo L, Zeng X, Trefely S, Fernandez S, Carrer A, Miller KD, Schug ZT, Snyder NW, Gade TP, Titchenell PM, Rabinowitz JD, Wellen KE. Dietary fructose feeds hepatic lipogenesis via microbiota-derived acetate. Nature 2020; 579:586-591. [PMID: 32214246 PMCID: PMC7416516 DOI: 10.1038/s41586-020-2101-7] [Citation(s) in RCA: 267] [Impact Index Per Article: 66.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 01/21/2020] [Indexed: 02/06/2023]
Abstract
Consumption of fructose has risen markedly in recent decades owing to the use of sucrose and high-fructose corn syrup in beverages and processed foods1, and this has contributed to increasing rates of obesity and non-alcoholic fatty liver disease2-4. Fructose intake triggers de novo lipogenesis in the liver4-6, in which carbon precursors of acetyl-CoA are converted into fatty acids. The ATP citrate lyase (ACLY) enzyme cleaves cytosolic citrate to generate acetyl-CoA, and is upregulated after consumption of carbohydrates7. Clinical trials are currently pursuing the inhibition of ACLY as a treatment for metabolic diseases8. However, the route from dietary fructose to hepatic acetyl-CoA and lipids remains unknown. Here, using in vivo isotope tracing, we show that liver-specific deletion of Acly in mice is unable to suppress fructose-induced lipogenesis. Dietary fructose is converted to acetate by the gut microbiota9, and this supplies lipogenic acetyl-CoA independently of ACLY10. Depletion of the microbiota or silencing of hepatic ACSS2, which generates acetyl-CoA from acetate, potently suppresses the conversion of bolus fructose into hepatic acetyl-CoA and fatty acids. When fructose is consumed more gradually to facilitate its absorption in the small intestine, both citrate cleavage in hepatocytes and microorganism-derived acetate contribute to lipogenesis. By contrast, the lipogenic transcriptional program is activated in response to fructose in a manner that is independent of acetyl-CoA metabolism. These data reveal a two-pronged mechanism that regulates hepatic lipogenesis, in which fructolysis within hepatocytes provides a signal to promote the expression of lipogenic genes, and the generation of microbial acetate feeds lipogenic pools of acetyl-CoA.
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Affiliation(s)
- Steven Zhao
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Cell & Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Cholsoon Jang
- Department of Chemistry and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Joyce Liu
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Biochemistry & Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Kahealani Uehara
- Biochemistry & Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Michael Gilbert
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Biochemistry & Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Luke Izzo
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Cell & Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Xianfeng Zeng
- Department of Chemistry and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Sophie Trefely
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Center for Metabolic Disease Research, Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Sully Fernandez
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Alessandro Carrer
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Veneto Institute of Molecular Medicine (VIMM), Padua, Italy
| | - Katelyn D Miller
- Molecular and Cellular Oncogenesis, Wistar Institute, Philadelphia, PA, USA
| | - Zachary T Schug
- Molecular and Cellular Oncogenesis, Wistar Institute, Philadelphia, PA, USA
| | - Nathaniel W Snyder
- Center for Metabolic Disease Research, Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Terence P Gade
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Paul M Titchenell
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Joshua D Rabinowitz
- Department of Chemistry and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Kathryn E Wellen
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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10
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Iizuka K, Takao K, Yabe D. ChREBP-Mediated Regulation of Lipid Metabolism: Involvement of the Gut Microbiota, Liver, and Adipose Tissue. Front Endocrinol (Lausanne) 2020; 11:587189. [PMID: 33343508 PMCID: PMC7744659 DOI: 10.3389/fendo.2020.587189] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 11/09/2020] [Indexed: 12/22/2022] Open
Abstract
Carbohydrate response element-binding protein (ChREBP) plays an important role in the development of type 2 diabetes, dyslipidemia, and non-alcoholic fatty liver disease, as well as tumorigenesis. ChREBP is highly expressed in lipogenic organs, such as liver, intestine, and adipose tissue, in which it regulates the production of acetyl CoA from glucose by inducing Pklr and Acyl expression. It has recently been demonstrated that ChREBP plays a role in the conversion of gut microbiota-derived acetate to acetyl CoA by activating its target gene, Acss2, in the liver. ChREBP regulates fatty acid synthesis, elongation, and desaturation by inducing Acc1 and Fasn, elongation of long-chain fatty acids family member 6 (encoded by Elovl6), and Scd1 expression, respectively. ChREBP also regulates the formation of very low-density lipoprotein by inducing the expression of Mtp. Furthermore, it plays a crucial role in peripheral lipid metabolism by inducing Fgf21 expression, as well as that of Angptl3 and Angptl8, which are known to reduce peripheral lipoprotein lipase activity. In addition, ChREBP is involved in the production of palmitic-acid-5-hydroxystearic-acid, which increases insulin sensitivity in adipose tissue. Curiously, ChREBP is indirectly involved in fatty acid β-oxidation and subsequent ketogenesis. Thus, ChREBP regulates whole-body lipid metabolism by controlling the transcription of lipogenic enzymes and liver-derived cytokines.
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Affiliation(s)
- Katsumi Iizuka
- Department of Diabetes and Endocrinology, Gifu University Graduate School of Medicine, Gifu, Japan
- Center for Nutritional Support and Infection Control, Gifu University Hospital, Gifu, Japan
- *Correspondence: Katsumi Iizuka,
| | - Ken Takao
- Department of Diabetes and Endocrinology, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Daisuke Yabe
- Department of Diabetes and Endocrinology, Gifu University Graduate School of Medicine, Gifu, Japan
- Yutaka Seino Distinguished Center for Diabetes Research, Kansai Electric Power Medical Research Institute, Kobe, Japan
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
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11
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Lucio M, Willkommen D, Schroeter M, Sigaroudi A, Schmitt-Kopplin P, Michalke B. Integrative Metabolomic and Metallomic Analysis in a Case-Control Cohort With Parkinson's Disease. Front Aging Neurosci 2019; 11:331. [PMID: 31866853 PMCID: PMC6908950 DOI: 10.3389/fnagi.2019.00331] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 11/18/2019] [Indexed: 01/29/2023] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disease with a complex etiology. Several factors are known to contribute to the disease onset and its progression. However, the complete underlying mechanisms are still escaping our understanding. To evaluate possible correlations between metabolites and metallomic data, in this research, we combined a control study measured using two different platforms. For the different data sources, we applied a Block Sparse Partial Least Square Discriminant Analysis (Block-sPLS-DA) model that allows for proving their relation, which in turn uncovers alternative influencing factors that remain hidden otherwise. We found two groups of variables that trace a strong relationship between metallomic and metabolomic parameters for disease development. The results confirmed that the redox active metals iron (Fe) and copper (Cu) together with fatty acids are the major influencing factors for the PD. Additionally, the metabolic waste product p-cresol sulfate and the trace element nickel (Ni) showed up as potentially important factors in PD. In summary, the data integration of different types of measurements emphasized the results of both stand-alone measurements providing a new comprehensive set of information and interactions, on PD disease, between different variables sources.
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Affiliation(s)
- Marianna Lucio
- Analytische BioGeoChemie, Helmholtz Zentrum München, Neuherberg, Germany
| | - Desiree Willkommen
- Analytische BioGeoChemie, Helmholtz Zentrum München, Neuherberg, Germany
| | - Michael Schroeter
- Klinik und Poliklinik für Neurologie, Uniklinik Köln, Cologne, Germany
| | - Ali Sigaroudi
- Klinik für Klinische Pharmakologie und Toxikologie, Universitätsspital Zürich, Zurich, Switzerland
- Institut I für Pharmakologie, Zentrum für Pharmakologie, Uniklinik Köln, Cologne, Germany
| | - Philippe Schmitt-Kopplin
- Analytische BioGeoChemie, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Analytical Food Chemistry, Life Science Center Weihenstephan, Technical University of Munich, Munich, Germany
| | - Bernhard Michalke
- Analytische BioGeoChemie, Helmholtz Zentrum München, Neuherberg, Germany
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12
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Watamoto Y, Futawaka K, Hayashi M, Matsushita M, Mitsutani M, Song Z, Koyama R, Fukuda Y, Nushida A, Nezu S, Kuwahara A, Kataoka K, Tagami T, Moriyama K. IGF-1 regulate the expression of uncoupling protein 2 via FOXO1. Growth Factors 2019; 37:247-256. [PMID: 32156173 DOI: 10.1080/08977194.2020.1739032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Mitochondria uncoupling protein2 (UCP2) expressed ubiquitously is a key molecule of energy metabolism. Insulin-like growth factor-1 (IGF-1) is a hormone, a target molecule of growth hormone (GH) signal pathway, which is also known as the drug "mecasermin" for clinical usages. IGF-1 is seemed to be closely related to metabolic diseases, such as adult GH deficiency. However, there has not been reports depicted possible relationship with each other. So, we sought to elucidate the mechanisms by which expression of UCP2 is regulated by IGF-1 via FOXO1. The findings suggested that three sequences in the consensus UCP2 promoter play complementary functional roles in the functional expression of FOXO1. So, we found that FOXO1 is involved in IGF-1-mediated energy metabolism greater than that of direct action of GH via STAT5. Our findings suggested that IGF-1 was involved in energy metabolism by regulating the expression of UCP2 via the PI3K/Akt/FOXO1 pathway.
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Affiliation(s)
- Yukiko Watamoto
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Kumi Futawaka
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Misa Hayashi
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Midori Matsushita
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Mana Mitsutani
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Zilin Song
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Rie Koyama
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Yuki Fukuda
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Ayaka Nushida
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Syoko Nezu
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Akiko Kuwahara
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Kazusaburo Kataoka
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
| | - Tetsuya Tagami
- Clinical Research Institute for Endocrine and Metabolic Diseases, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
| | - Kenji Moriyama
- Medicine and Clinical Science, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan
- Clinical Research Institute for Endocrine and Metabolic Diseases, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
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13
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Okamoto T, Morino K, Ugi S, Nakagawa F, Lemecha M, Ida S, Ohashi N, Sato D, Fujita Y, Maegawa H. Microbiome potentiates endurance exercise through intestinal acetate production. Am J Physiol Endocrinol Metab 2019; 316:E956-E966. [PMID: 30860879 DOI: 10.1152/ajpendo.00510.2018] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The intestinal microbiome produces short-chain fatty acids (SCFAs) from dietary fiber and has specific effects on other organs. During endurance exercise, fatty acids, glucose, and amino acids are major energy substrates. However, little is known about the role of SCFAs during exercise. To investigate this, mice were administered either multiple antibiotics or a low microbiome-accessible carbohydrate (LMC) diet, before endurance testing on a treadmill. Two-week antibiotic treatment significantly reduced endurance capacity versus the untreated group. In the cecum acetate, propionate, and butyrate became almost undetectable in the antibiotic-treated group, plasma SCFA concentrations were lower, and the microbiome was disrupted. Similarly, 6-wk LMC treatment significantly reduced exercise capacity, and fecal and plasma SCFA concentrations. Continuous acetate but not saline infusion in antibiotic-treated mice restored their exercise capacity (P < 0.05), suggesting that plasma acetate may be an important energy substrate during endurance exercise. In addition, running time was significantly improved in LMC-fed mice by fecal microbiome transplantation from others fed a high microbiome-accessible carbohydrate diet and administered a single portion of fermentable fiber (P < 0.05). In conclusion, the microbiome can contribute to endurance exercise by producing SCFAs. Our findings provide new insight into the effects of the microbiome on systemic metabolism.
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Affiliation(s)
- Takuya Okamoto
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
| | - Katsutaro Morino
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
| | - Satoshi Ugi
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
| | - Fumiyuki Nakagawa
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
- CMIC Pharma Science, Osaka , Japan
| | - Mengistu Lemecha
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
| | - Shogo Ida
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
| | - Natsuko Ohashi
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
| | - Daisuke Sato
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
| | - Yukihiro Fujita
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
| | - Hiroshi Maegawa
- Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science , Otsu , Japan
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14
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Del Giovane A, Ragnini-Wilson A. Targeting Smoothened as a New Frontier in the Functional Recovery of Central Nervous System Demyelinating Pathologies. Int J Mol Sci 2018; 19:E3677. [PMID: 30463396 PMCID: PMC6274747 DOI: 10.3390/ijms19113677] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/09/2018] [Accepted: 11/14/2018] [Indexed: 12/20/2022] Open
Abstract
Myelin sheaths on vertebrate axons provide protection, vital support and increase the speed of neuronal signals. Myelin degeneration can be caused by viral, autoimmune or genetic diseases. Remyelination is a natural process that restores the myelin sheath and, consequently, neuronal function after a demyelination event, preventing neurodegeneration and thereby neuron functional loss. Pharmacological approaches to remyelination represent a promising new frontier in the therapy of human demyelination pathologies and might provide novel tools to improve adaptive myelination in aged individuals. Recent phenotypical screens have identified agonists of the atypical G protein-coupled receptor Smoothened and inhibitors of the glioma-associated oncogene 1 as being amongst the most potent stimulators of oligodendrocyte precursor cell (OPC) differentiation in vitro and remyelination in the central nervous system (CNS) of mice. Here, we discuss the current state-of-the-art of studies on the role of Sonic Hedgehog reactivation during remyelination, referring readers to other reviews for the role of Hedgehog signaling in cancer and stem cell maintenance.
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Affiliation(s)
- Alice Del Giovane
- Department of Biology University of Rome Tor Vergata, Viale Della Ricerca Scientifica, 00133 Rome, Italy.
| | - Antonella Ragnini-Wilson
- Department of Biology University of Rome Tor Vergata, Viale Della Ricerca Scientifica, 00133 Rome, Italy.
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15
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Alam S, Carter GS, Krager KJ, Li X, Lehmler HJ, Aykin-Burns N. PCB11 Metabolite, 3,3'-Dichlorobiphenyl-4-ol, Exposure Alters the Expression of Genes Governing Fatty Acid Metabolism in the Absence of Functional Sirtuin 3: Examining the Contribution of MnSOD. Antioxidants (Basel) 2018; 7:antiox7090121. [PMID: 30223548 PMCID: PMC6162768 DOI: 10.3390/antiox7090121] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/10/2018] [Accepted: 09/13/2018] [Indexed: 01/12/2023] Open
Abstract
Although the production of polychlorinated biphenyls (PCBs) is prohibited, the inadvertent production of certain lower-chlorinated PCB congeners still threatens human health. We and others have identified 3,3’-dichlorobiphenyl (PCB11) and its metabolite, 3,3’-dichlorobiphenyl-4-ol (4OH-PCB11), in human blood, and there is a correlation between exposure to this metabolite and mitochondrial oxidative stress in mammalian cells. Here, we evaluated the downstream effects of 4OH-PCB11 on mitochondrial metabolism and function in the presence and absence of functional Sirtuin 3 (SIRT3), a mitochondrial fidelity protein that protects redox homeostasis. A 24 h exposure to 3 μM 4OH-PCB11 significantly decreased the cellular growth and mitochondrial membrane potential of SIRT3-knockout mouse embryonic fibroblasts (MEFs). Only wild-type cells demonstrated an increase in Manganese superoxide dismutase (MnSOD) activity in response to 4OH-PCB11–induced oxidative injury. This suggests the presence of a SIRT3-mediated post-translational modification to MnSOD, which was impaired in SIRT3-knockout MEFs, which counters the PCB insult. We found that 4OH-PCB11 increased mitochondrial respiration and endogenous fatty-acid oxidation-associated oxygen consumption in SIRT3-knockout MEFs; this appeared to occur because the cells exhausted their reserve respiratory capacity. To determine whether these changes in mitochondrial respiration were accompanied by similar changes in the regulation of fatty acid metabolism, we performed quantitative real-time polymerase chain reaction (qRT-PCR) after a 24 h treatment with 4OH-PCB11. In SIRT3-knockout MEFs, 4OH-PCB11 significantly increased the expression of ten genes controlling fatty acid biosynthesis, metabolism, and transport. When we overexpressed MnSOD in these cells, the expression of six of these genes returned to the baseline level, suggesting that the protective role of SIRT3 against 4OH-PCB11 is partially governed by MnSOD activity.
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Affiliation(s)
- Sinthia Alam
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Gwendolyn S Carter
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Kimberly J Krager
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, Iowa City, IA 52242, USA.
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, Iowa City, IA 52242, USA.
| | - Nukhet Aykin-Burns
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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16
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Comparative Proteomic Analysis of Rana chensinensis Oviduct. Molecules 2018; 23:molecules23061384. [PMID: 29890619 PMCID: PMC6099995 DOI: 10.3390/molecules23061384] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 05/31/2018] [Accepted: 06/05/2018] [Indexed: 12/31/2022] Open
Abstract
As one of most important traditional Chinese medicine resources, the oviduct of female Rana chensinensis (Chinese brown frog) was widely used in the treatment of asthenia after sickness or delivery, deficiency in vigor, palpitation, and insomnia. Unlike other vertebrates, the oviduct of Rana chensinensis oviduct significantly expands during prehibernation, in contrast to the breeding period. To explain this phenomenon at the molecular level, the protein expression profiles of Rana chensinensis oviduct during the breeding period and prehibernation were observed using isobaric tags for relative and absolute quantitation (iTRAQ) technique. Then, all identified proteins were used to obtain gene ontology (GO) annotation. Ultimately, KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis was performed to predict the pathway on differentially expressed proteins (DEPs). A total of 4479 proteins were identified, and 312 of them presented different expression profiling between prehibernation and breeding period. Compared with prehibernation group, 86 proteins were upregulated, and 226 proteins were downregulated in breeding period. After KEGG enrichment analysis, 163 DEPs were involved in 6 pathways, which were lysosome, RNA transport, glycosaminoglycan degradation, extracellular matrix (ECM)–receptor interaction, metabolic pathways and focal adhesion. This is the first report on the protein profiling of Rana chensinensis oviduct during the breeding period and prehibernation. Results show that this distinctive physiological phenomenon of Rana chensinensis oviduct was mainly involved in ECM–receptor interaction, metabolic pathways, and focal adhesion.
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17
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Steensels S, Ersoy BA. Fatty acid activation in thermogenic adipose tissue. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:79-90. [PMID: 29793055 DOI: 10.1016/j.bbalip.2018.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 03/10/2018] [Accepted: 05/17/2018] [Indexed: 02/07/2023]
Abstract
Channeling carbohydrates and fatty acids to thermogenic tissues, including brown and beige adipocytes, have garnered interest as an approach for the management of obesity-related metabolic disorders. Mitochondrial fatty acid oxidation (β-oxidation) is crucial for the maintenance of thermogenesis. Upon cellular fatty acid uptake or following lipolysis from triglycerides (TG), fatty acids are esterified to coenzyme A (CoA) to form active acyl-CoA molecules. This enzymatic reaction is essential for their utilization in β-oxidation and thermogenesis. The activation and deactivation of fatty acids are regulated by two sets of enzymes called acyl-CoA synthetases (ACS) and acyl-CoA thioesterases (ACOT), respectively. The expression levels of ACS and ACOT family members in thermogenic tissues will determine the substrate availability for β-oxidation, and consequently the thermogenic capacity. Although the role of the majority of ACS and ACOT family members in thermogenesis remains unclear, recent proceedings link the enzymatic activities of ACS and ACOT family members to metabolic disorders and thermogenesis. Elucidating the contributions of specific ACS and ACOT family members to trafficking of fatty acids towards thermogenesis may reveal novel targets for modulating thermogenic capacity and treating metabolic disorders.
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Affiliation(s)
- Sandra Steensels
- Department of Medicine, Division of Gastroenterology and Hepatology, Weill Cornell Medical College, New York, NY, USA
| | - Baran A Ersoy
- Department of Medicine, Division of Gastroenterology and Hepatology, Weill Cornell Medical College, New York, NY, USA.
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18
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Kondo A, Yamamoto S, Nakaki R, Shimamura T, Hamakubo T, Sakai J, Kodama T, Yoshida T, Aburatani H, Osawa T. Extracellular Acidic pH Activates the Sterol Regulatory Element-Binding Protein 2 to Promote Tumor Progression. Cell Rep 2017; 18:2228-2242. [PMID: 28249167 DOI: 10.1016/j.celrep.2017.02.006] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 12/29/2016] [Accepted: 01/31/2017] [Indexed: 02/04/2023] Open
Abstract
Conditions of the tumor microenvironment, such as hypoxia and nutrient starvation, play critical roles in cancer progression. However, the role of acidic extracellular pH in cancer progression is not studied as extensively as that of hypoxia. Here, we show that extracellular acidic pH (pH 6.8) triggered activation of sterol regulatory element-binding protein 2 (SREBP2) by stimulating nuclear translocation and promoter binding to its targets, along with intracellular acidification. Interestingly, inhibition of SREBP2, but not SREBP1, suppressed the upregulation of low pH-induced cholesterol biosynthesis-related genes. Moreover, acyl-CoA synthetase short-chain family member 2 (ACSS2), a direct SREBP2 target, provided a growth advantage to cancer cells under acidic pH. Furthermore, acidic pH-responsive SREBP2 target genes were associated with reduced overall survival of cancer patients. Thus, our findings show that SREBP2 is a key transcriptional regulator of metabolic genes and progression of cancer cells, partly in response to extracellular acidification.
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Affiliation(s)
- Ayano Kondo
- Division of Genome Science, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan; Innovative Technology Laboratories, Kyowa Hakko Kirin Co., Ltd. 3-6-6 Asahimachi, Machida, Tokyo, 194-8533, Japan
| | - Shogo Yamamoto
- Division of Genome Science, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan
| | - Ryo Nakaki
- Division of Genome Science, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan
| | - Teppei Shimamura
- Department of Systems Biology, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan
| | - Takao Hamakubo
- Department of Quantitative Biology and Medicine, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan
| | - Juro Sakai
- Division of Metabolic Medicine, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan; The Translational Systems Biology and Medicine Initiative (TSBMI), Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Tatsuhiko Kodama
- Laboratory for Systems Biology and Medicine, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan
| | - Tetsuo Yoshida
- Translational Research Unit, Kyowa Hakko Kirin Co., Ltd. 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 441-8731, Japan
| | - Hiroyuki Aburatani
- Division of Genome Science, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan; The Translational Systems Biology and Medicine Initiative (TSBMI), Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.
| | - Tsuyoshi Osawa
- The Translational Systems Biology and Medicine Initiative (TSBMI), Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; Laboratory for Systems Biology and Medicine, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan.
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19
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Jackson LE, Kulkarni S, Wang H, Lu J, Dolezal JM, Bharathi SS, Ranganathan S, Patel MS, Deshpande R, Alencastro F, Wendell SG, Goetzman ES, Duncan AW, Prochownik EV. Genetic Dissociation of Glycolysis and the TCA Cycle Affects Neither Normal nor Neoplastic Proliferation. Cancer Res 2017; 77:5795-5807. [PMID: 28883002 DOI: 10.1158/0008-5472.can-17-1325] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/19/2017] [Accepted: 09/01/2017] [Indexed: 12/25/2022]
Abstract
Rapidly proliferating cells increase glycolysis at the expense of oxidative phosphorylation (oxphos) to generate sufficient levels of glycolytic intermediates for use as anabolic substrates. The pyruvate dehydrogenase complex (PDC) is a critical mitochondrial enzyme that catalyzes pyruvate's conversion to acetyl coenzyme A (AcCoA), thereby connecting these two pathways in response to complex energetic, enzymatic, and metabolic cues. Here we utilized a mouse model of hepatocyte-specific PDC inactivation to determine the need for this metabolic link during normal hepatocyte regeneration and malignant transformation. In PDC "knockout" (KO) animals, the long-term regenerative potential of hepatocytes was unimpaired, and growth of aggressive experimental hepatoblastomas was only modestly slowed in the face of 80%-90% reductions in AcCoA and significant alterations in the levels of key tricarboxylic acid (TCA) cycle intermediates and amino acids. Overall, oxphos activity in KO livers and hepatoblastoma was comparable with that of control counterparts, with evidence that metabolic substrate abnormalities were compensated for by increased mitochondrial mass. These findings demonstrate that the biochemical link between glycolysis and the TCA cycle can be completely severed without affecting normal or neoplastic proliferation, even under the most demanding circumstances. Cancer Res; 77(21); 5795-807. ©2017 AACR.
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Affiliation(s)
- Laura E Jackson
- Division of Neonatology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Sucheta Kulkarni
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Huabo Wang
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Jie Lu
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - James M Dolezal
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Sivakama S Bharathi
- Division of Medical Genetics, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Sarangarajan Ranganathan
- Department of Pathology, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Mulchand S Patel
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, New York
| | - Rahul Deshpande
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Frances Alencastro
- Department of Pathology, The McGowan Institute for Regenerative Medicine and The Pittsburgh Liver Research Center, The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Stacy G Wendell
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Eric S Goetzman
- Division of Medical Genetics, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Andrew W Duncan
- Department of Pathology, The McGowan Institute for Regenerative Medicine and The Pittsburgh Liver Research Center, The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Edward V Prochownik
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania. .,Department of Microbiology and Molecular Genetics, The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.,The University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania
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Yoshimura Y, Araki A, Maruta H, Takahashi Y, Yamashita H. Molecular cloning of rat acss3 and characterization of mammalian propionyl-CoA synthetase in the liver mitochondrial matrix. J Biochem 2017; 161:279-289. [PMID: 28003429 DOI: 10.1093/jb/mvw067] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 10/27/2016] [Indexed: 12/13/2022] Open
Abstract
Among the three acyl-CoA synthetase short-chain family members (ACSS), ACSS3 is poorly characterized. To characterize ACSS3, we performed molecular cloning and protein expression of rat acss3 and determined its intracellular localization, tissue distribution, and substrate specificity. Transient expression of rat ACSS3 in HeLa cells resulted in a 10-fold increase of acetyl-CoA synthetase activity compared with that in control cells. The acss3 transcripts are expressed in a wide range of tissues, with the highest levels observed in liver tissue followed by kidney tissue. Subcellular fractionation using liver tissue showed that ACSS3 is localized into the mitochondrial matrix. Among the short-chain fatty acids examined, recombinant ACSS3, purified from Escherichia coli cells transformed with the plasmid containing rat acss3, preferentially utilized propionate with a KM value of 0.19 mM. Knockdown of acss3 in HepG2 cells resulted in a significant decrease of ACSS3 expression level and propionyl-CoA synthetase activity in cell lysates. Levels of ACSS3 in the liver and the activity of propionyl-CoA synthetase in the mitochondria were significantly increased by fasting. These results suggested that ACSS3 is a liver mitochondrial matrix enzyme with high affinity to propionic acid, and its expression level is upregulated under ketogenic conditions.
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Affiliation(s)
- Yukihiro Yoshimura
- Department of Nutritional Science Faculty of Health and Welfare Science, Okayama Prefectural University, 111 Kuboki, Soja-shi, Okayama 719-1197, Japan
| | - Aya Araki
- Department of Nutritional Science Faculty of Health and Welfare Science, Okayama Prefectural University, 111 Kuboki, Soja-shi, Okayama 719-1197, Japan
| | - Hitomi Maruta
- Department of Nutritional Science Faculty of Health and Welfare Science, Okayama Prefectural University, 111 Kuboki, Soja-shi, Okayama 719-1197, Japan
| | - Yoshitaka Takahashi
- Department of Nutritional Science Faculty of Health and Welfare Science, Okayama Prefectural University, 111 Kuboki, Soja-shi, Okayama 719-1197, Japan
| | - Hiromi Yamashita
- Department of Nutritional Science Faculty of Health and Welfare Science, Okayama Prefectural University, 111 Kuboki, Soja-shi, Okayama 719-1197, Japan
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21
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Soumya N, Panara MN, Neerupudi KB, Singh S. Functional analysis of an AMP forming acetyl CoA synthetase from Leishmania donovani by gene overexpression and targeted gene disruption approaches. Parasitol Int 2016; 66:992-1002. [PMID: 27825908 DOI: 10.1016/j.parint.2016.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/03/2016] [Indexed: 01/08/2023]
Abstract
Leishmaniasis, a neglected tropical disease is endemic in 98 countries and >350 million people are at risk of getting the infection. The existing chemotherapy of Leishmaniasis is limited due to adverse effects, resistance to existing drugs and increasing cases of HIV-Leishmaniasis co-infection. Hence, there is a need to identify novel metabolic pathways for design of new chemical entities. Acetyl-CoA synthetase (AceCS) is an enzyme of acetate metabolic pathway whose functions are unknown in Leishmania parasite. AceCS from Leishmania donovani (LdAceCS) is significantly different from human host to be explored as a potential drug candidate to develop parasite specific inhibitors. To dissect the functions of LdAceCS in Leishmania promastigotes, two approaches were followed. LdAceCS overexpressing parasites were generated by episomal expression of LdAceCS in promastigotes and single knockout (SKO) cell lines of LdAceCS were generated by targeted gene disruption. An insight into the phenotypic changes undergone by the overexpressors revealed an increase in LdAceCS activity, total lipid content, infectivity and ergosterol levels by ~2.2, 2.2, 1.65 and 3 fold respectively with respect to wild type. Similarly SKO transgenic parasites exhibited ~2.5, 3, 1.5 and 3 fold decrease in activity, total lipid content, infectivity and ergosterol respectively. Repeated attempts to generate null mutants failed thus indicating that LdAceCS is essential for the parasite and can be selectively targeted to combat Leishmania infection. The present study demonstrates that LdAceCS is important for in vitro macrophage infection and is also essential for biosynthesis of total lipids and ergosterol.
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Affiliation(s)
- Neelagiri Soumya
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, Punjab, India
| | - Mitesh N Panara
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, Punjab, India
| | - Kishore Babu Neerupudi
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, Punjab, India
| | - Sushma Singh
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, Punjab, India.
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Ashikawa Y, Nishimura Y, Okabe S, Sasagawa S, Murakami S, Yuge M, Kawaguchi K, Kawase R, Tanaka T. Activation of Sterol Regulatory Element Binding Factors by Fenofibrate and Gemfibrozil Stimulates Myelination in Zebrafish. Front Pharmacol 2016; 7:206. [PMID: 27462272 PMCID: PMC4939524 DOI: 10.3389/fphar.2016.00206] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 06/28/2016] [Indexed: 01/01/2023] Open
Abstract
Oligodendrocytes are major myelin-producing cells and play essential roles in the function of a healthy nervous system. However, they are also one of the most vulnerable neural cell types in the central nervous system (CNS), and myelin abnormalities in the CNS are found in a wide variety of neurological disorders, including multiple sclerosis, adrenoleukodystrophy, and schizophrenia. There is an urgent need to identify small molecular weight compounds that can stimulate myelination. In this study, we performed comparative transcriptome analysis to identify pharmacodynamic effects common to miconazole and clobetasol, which have been shown to stimulate myelination by mouse oligodendrocyte progenitor cells (OPCs). Of the genes differentially expressed in both miconazole- and clobetasol-treated mouse OPCs compared with untreated cells, we identified differentially expressed genes (DEGs) common to both drug treatments. Gene ontology analysis revealed that these DEGs are significantly associated with the sterol biosynthetic pathway, and further bioinformatics analysis suggested that sterol regulatory element binding factors (SREBFs) might be key upstream regulators of the DEGs. In silico screening of a public database for chemicals associated with SREBF activation identified fenofibrate, a peroxisome proliferator-activated receptor α (PPARα) agonist, as a drug that increases the expression of known SREBF targets, raising the possibility that fenofibrate may also stimulate myelination. To test this, we performed in vivo imaging of zebrafish expressing a fluorescent reporter protein under the control of the myelin basic protein (mbp) promoter. Treatment of zebrafish with fenofibrate significantly increased expression of the fluorescent reporter compared with untreated zebrafish. This increase was attenuated by co-treatment with fatostatin, a specific inhibitor of SREBFs, confirming that the fenofibrate effect was mediated via SREBFs. Furthermore, incubation of zebrafish with another PPARα agonist, gemfibrozil, also increased expression of the mbp promoter-driven fluorescent reporter in an SREBF-dependent manner. These results suggest that activation of SREBFs by small molecular weight compounds may be a feasible therapeutic approach to stimulate myelination.
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Affiliation(s)
- Yoshifumi Ashikawa
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine Tsu, Japan
| | - Yuhei Nishimura
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of MedicineTsu, Japan; Department of Systems Pharmacology, Mie University Graduate School of MedicineTsu, Japan; Mie University Medical Zebrafish Research CenterTsu, Japan; Department of Omics Medicine, Mie University Industrial Technology Innovation InstituteTsu, Japan; Department of Bioinformatics, Mie University Life Science Research CenterTsu, Japan
| | - Shiko Okabe
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine Tsu, Japan
| | - Shota Sasagawa
- Department of Systems Pharmacology, Mie University Graduate School of Medicine Tsu, Japan
| | - Soichiro Murakami
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine Tsu, Japan
| | - Mizuki Yuge
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine Tsu, Japan
| | - Koki Kawaguchi
- Department of Systems Pharmacology, Mie University Graduate School of Medicine Tsu, Japan
| | - Reiko Kawase
- Department of Systems Pharmacology, Mie University Graduate School of Medicine Tsu, Japan
| | - Toshio Tanaka
- Department of Systems Pharmacology, Mie University Graduate School of MedicineTsu, Japan; Mie University Medical Zebrafish Research CenterTsu, Japan; Department of Omics Medicine, Mie University Industrial Technology Innovation InstituteTsu, Japan; Department of Bioinformatics, Mie University Life Science Research CenterTsu, Japan
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23
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Geng F, Cheng X, Wu X, Yoo JY, Cheng C, Guo JY, Mo X, Ru P, Hurwitz B, Kim SH, Otero J, Puduvalli V, Lefai E, Ma J, Nakano I, Horbinski C, Kaur B, Chakravarti A, Guo D. Inhibition of SOAT1 Suppresses Glioblastoma Growth via Blocking SREBP-1-Mediated Lipogenesis. Clin Cancer Res 2016; 22:5337-5348. [PMID: 27281560 DOI: 10.1158/1078-0432.ccr-15-2973] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/27/2016] [Indexed: 12/17/2022]
Abstract
PURPOSE Elevated lipogenesis regulated by sterol regulatory element-binding protein-1 (SREBP-1), a transcription factor playing a central role in lipid metabolism, is a novel characteristic of glioblastoma (GBM). The aim of this study was to identify effective approaches to suppress GBM growth by inhibition of SREBP-1. As SREBP activation is negatively regulated by endoplasmic reticulum (ER) cholesterol, we sought to determine whether suppression of sterol O-acyltransferase (SOAT), a key enzyme converting ER cholesterol to cholesterol esters (CE) to store in lipid droplets (LDs), effectively suppressed SREBP-1 and blocked GBM growth. EXPERIMENTAL DESIGN The presence of LDs in glioma patient tumor tissues was analyzed using immunofluorescence, immunohistochemistry, and electronic microscopy. Western blotting and real-time PCR were performed to analyze protein levels and gene expression of GBM cells, respectively. Intracranial GBM xenografts were used to determine the effects of genetically silencing SOAT1 and SREBP-1 on tumor growth. RESULTS Our study unraveled that cholesterol esterification and LD formation are signature of GBM, and human patients with glioma possess elevated LDs that correlate with GBM progression and poor survival. We revealed that SOAT1 is highly expressed in GBM and functions as a key player in controlling the cholesterol esterification and storage in GBM. Targeting SOAT1 suppresses GBM growth and prolongs survival in xenograft models via inhibition of SREBP-1-regulated lipid synthesis. CONCLUSIONS Cholesterol esterification and storage in LDs are novel characteristics of GBM, and inhibiting SOAT1 to block cholesterol esterification is a promising therapeutic strategy to treat GBM by suppressing SREBP-1. Clin Cancer Res; 22(21); 5337-48. ©2016 AACR.
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Affiliation(s)
- Feng Geng
- Department of Radiation Oncology, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Xiang Cheng
- Department of Radiation Oncology, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Xiaoning Wu
- Department of Radiation Oncology, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Ji Young Yoo
- Department of Neurosurgery, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Chunming Cheng
- Department of Radiation Oncology, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Jeffrey Yunhua Guo
- Department of Radiation Oncology, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Xiaokui Mo
- Center for Biostatistics, Department of Biomedical Informatics, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Peng Ru
- Department of Radiation Oncology, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Brian Hurwitz
- Department of Neurosurgery, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Sung-Hak Kim
- Department of Neurosurgery at University Alabama at Birmingham, Alabama
| | - Jose Otero
- Department of Pathology, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Vinay Puduvalli
- Department of Neurosurgery, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Etienne Lefai
- CarMeN Laboratory, INSERM U1060, INRA 1397, Faculté de Médecine Lyon Sud, University de Lyon, Oullins, France
| | - Jianjie Ma
- Department of Surgery, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Ichiro Nakano
- Department of Neurosurgery at University Alabama at Birmingham, Alabama
| | - Craig Horbinski
- Departments of Pathology and Neurosurgery at Northwestern University, Chicago, Illinois
| | - Balveen Kaur
- Department of Neurosurgery, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Arnab Chakravarti
- Department of Radiation Oncology, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio
| | - Deliang Guo
- Department of Radiation Oncology, James Comprehensive Cancer Center & Arthur G James Cancer Hospital, The Ohio State Medical Center, Columbus, Ohio.
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24
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Buček A, Brabcová J, Vogel H, Prchalová D, Kindl J, Valterová I, Pichová I. Exploring complex pheromone biosynthetic processes in the bumblebee male labial gland by RNA sequencing. INSECT MOLECULAR BIOLOGY 2016; 25:295-314. [PMID: 26945888 DOI: 10.1111/imb.12221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Male marking pheromones (MPs) are used by the majority of bumblebee species (Hymenoptera: Apidae), including a commercially important greenhouse pollinator, the buff-tailed bumblebee (Bombus terrestris), to attract conspecific females. MP biosynthetic processes in the cephalic part of the bumblebee male labial gland (LG) are of extraordinary complexity, involving enzymes of fatty acid and isoprenoid biosynthesis, which jointly produce more than 50 compounds. We employed a differential transcriptomic approach to identify candidate genes involved in MP biosynthesis by sequencing Bombus terrestris LG and fat body (FB) transcriptomes. We identified 12 454 abundantly expressed gene products (reads per kilobase of exon model per million mapped reads value > 1) that had significant hits in the GenBank nonredundant database. Of these, 876 were upregulated in the LG (> 4-fold difference). We identified more than 140 candidate genes potentially involved in MP biosynthesis, including esterases, fatty acid reductases, lipases, enzymes involved in limited fatty acid chain shortening, neuropeptide receptors and enzymes involved in biosynthesis of triacylglycerols, isoprenoids and fatty acids. For selected candidates, we confirmed their abundant expression in LG using quantitative real-time reverse transcription-PCR (qRT-PCR). Our study shows that the Bombus terrestris LG transcriptome reflects both fatty acid and isoprenoid MP biosynthetic processes and identifies rational gene targets for future studies to disentangle the molecular basis of MP biosynthesis. Additionally, LG and FB transcriptomes enrich the available transcriptomic resources for Bombus terrestris.
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Affiliation(s)
- A Buček
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - J Brabcová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - H Vogel
- Max Planck Institute for Chemical Ecology, Jena, Germany
| | - D Prchalová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - J Kindl
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - I Valterová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - I Pichová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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25
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Lelieveld SH, Schütte J, Dijkstra MJJ, Bawono P, Kinston SJ, Göttgens B, Heringa J, Bonzanni N. ConBind: motif-aware cross-species alignment for the identification of functional transcription factor binding sites. Nucleic Acids Res 2016; 44:e72. [PMID: 26721389 PMCID: PMC4856970 DOI: 10.1093/nar/gkv1518] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 12/15/2015] [Accepted: 12/16/2015] [Indexed: 12/23/2022] Open
Abstract
Eukaryotic gene expression is regulated by transcription factors (TFs) binding to promoter as well as distal enhancers. TFs recognize short, but specific binding sites (TFBSs) that are located within the promoter and enhancer regions. Functionally relevant TFBSs are often highly conserved during evolution leaving a strong phylogenetic signal. While multiple sequence alignment (MSA) is a potent tool to detect the phylogenetic signal, the current MSA implementations are optimized to align the maximum number of identical nucleotides. This approach might result in the omission of conserved motifs that contain interchangeable nucleotides such as the ETS motif (IUPAC code: GGAW). Here, we introduce ConBind, a novel method to enhance alignment of short motifs, even if their mutual sequence similarity is only partial. ConBind improves the identification of conserved TFBSs by improving the alignment accuracy of TFBS families within orthologous DNA sequences. Functional validation of the Gfi1b + 13 enhancer reveals that ConBind identifies additional functionally important ETS binding sites that were missed by all other tested alignment tools. In addition to the analysis of known regulatory regions, our web tool is useful for the analysis of TFBSs on so far unknown DNA regions identified through ChIP-sequencing.
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Affiliation(s)
- Stefan H Lelieveld
- Centre for Integrative Bioinformatics VU, VU University Amsterdam, Amsterdam 1081 HV, The Netherlands Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands
| | - Judith Schütte
- Department of Haematology, Wellcome Trust-MRC Cambridge Stem Cell Institute & Cambridge Institute for Medical Research, Cambridge University, Cambridge CB2 0XY, UK Klinik für Hämatologie, Universitätsklinik Essen 45147, Germany
| | - Maurits J J Dijkstra
- Centre for Integrative Bioinformatics VU, VU University Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Punto Bawono
- Centre for Integrative Bioinformatics VU, VU University Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Sarah J Kinston
- Department of Haematology, Wellcome Trust-MRC Cambridge Stem Cell Institute & Cambridge Institute for Medical Research, Cambridge University, Cambridge CB2 0XY, UK
| | - Berthold Göttgens
- Department of Haematology, Wellcome Trust-MRC Cambridge Stem Cell Institute & Cambridge Institute for Medical Research, Cambridge University, Cambridge CB2 0XY, UK
| | - Jaap Heringa
- Centre for Integrative Bioinformatics VU, VU University Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Nicola Bonzanni
- Centre for Integrative Bioinformatics VU, VU University Amsterdam, Amsterdam 1081 HV, The Netherlands Computational Cancer Biology Group, Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam 1066 CX, The Netherlands ENPICOM, Eindhoven 5632 CW, The Netherlands
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26
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Liu J, Zhang J, He C, Duan A. Genes responsive to elevated CO2 concentrations in triploid white poplar and integrated gene network analysis. PLoS One 2014; 9:e98300. [PMID: 24847851 PMCID: PMC4029852 DOI: 10.1371/journal.pone.0098300] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 04/30/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The atmospheric CO2 concentration increases every year. While the effects of elevated CO2 on plant growth, physiology and metabolism have been studied, there is now a pressing need to understand the molecular mechanisms of how plants will respond to future increases in CO2 concentration using genomic techniques. PRINCIPAL FINDINGS Gene expression in triploid white poplar ((Populus tomentosa ×P. bolleana) ×P. tomentosa) leaves was investigated using the Affymetrix poplar genome gene chip, after three months of growth in controlled environment chambers under three CO2 concentrations. Our physiological findings showed the growth, assessed as stem diameter, was significantly increased, and the net photosynthetic rate was decreased in elevated CO2 concentrations. The concentrations of four major endogenous hormones appeared to actively promote plant development. Leaf tissues under elevated CO2 concentrations had 5,127 genes with different expression patterns in comparison to leaves under the ambient CO2 concentration. Among these, 8 genes were finally selected for further investigation by using randomized variance model corrective ANOVA analysis, dynamic gene expression profiling, gene network construction, and quantitative real-time PCR validation. Among the 8 genes in the network, aldehyde dehydrogenase and pyruvate kinase were situated in the core and had interconnections with other genes. CONCLUSIONS Under elevated CO2 concentrations, 8 significantly changed key genes involved in metabolism and responding to stimulus of external environment were identified. These genes play crucial roles in the signal transduction network and show strong correlations with elevated CO2 exposure. This study provides several target genes, further investigation of which could provide an initial step for better understanding the molecular mechanisms of plant acclimation and evolution in future rising CO2 concentrations.
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Affiliation(s)
- Juanjuan Liu
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Jianguo Zhang
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Caiyun He
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Aiguo Duan
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
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27
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Moffett JR, Arun P, Ariyannur PS, Namboodiri AMA. N-Acetylaspartate reductions in brain injury: impact on post-injury neuroenergetics, lipid synthesis, and protein acetylation. FRONTIERS IN NEUROENERGETICS 2013; 5:11. [PMID: 24421768 PMCID: PMC3872778 DOI: 10.3389/fnene.2013.00011] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 12/09/2013] [Indexed: 12/22/2022]
Abstract
N-Acetylaspartate (NAA) is employed as a non-invasive marker for neuronal health using proton magnetic resonance spectroscopy (MRS). This utility is afforded by the fact that NAA is one of the most concentrated brain metabolites and that it produces the largest peak in MRS scans of the healthy human brain. NAA levels in the brain are reduced proportionately to the degree of tissue damage after traumatic brain injury (TBI) and the reductions parallel the reductions in ATP levels. Because NAA is the most concentrated acetylated metabolite in the brain, we have hypothesized that NAA acts in part as an extensive reservoir of acetate for acetyl coenzyme A synthesis. Therefore, the loss of NAA after TBI impairs acetyl coenzyme A dependent functions including energy derivation, lipid synthesis, and protein acetylation reactions in distinct ways in different cell populations. The enzymes involved in synthesizing and metabolizing NAA are predominantly expressed in neurons and oligodendrocytes, respectively, and therefore some proportion of NAA must be transferred between cell types before the acetate can be liberated, converted to acetyl coenzyme A and utilized. Studies have indicated that glucose metabolism in neurons is reduced, but that acetate metabolism in astrocytes is increased following TBI, possibly reflecting an increased role for non-glucose energy sources in response to injury. NAA can provide additional acetate for intercellular metabolite trafficking to maintain acetyl CoA levels after injury. Here we explore changes in NAA, acetate, and acetyl coenzyme A metabolism in response to brain injury.
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Affiliation(s)
- John R. Moffett
- Neuroscience Program, Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health SciencesBethesda, MD, USA
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28
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Horibata Y, Ando H, Itoh M, Sugimoto H. Enzymatic and transcriptional regulation of the cytoplasmic acetyl-CoA hydrolase ACOT12. J Lipid Res 2013; 54:2049-2059. [PMID: 23709691 DOI: 10.1194/jlr.m030163] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Acyl-CoA thioesterase 12 (ACOT12) is the major enzyme known to hydrolyze the thioester bond of acetyl-CoA in the cytosol in the liver. ACOT12 contains a catalytic thioesterase domain at the N terminus and a steroidogenic acute regulatory protein-related lipid transfer (START) domain at the C terminus. We investigated the effects of lipids (phospholipids, sphingolipids, fatty acids, and sterols) on ACOT12 thioesterase activity and found that the activity was inhibited by phosphatidic acid (PA) in a noncompetitive manner. In contrast, the enzymatic activity of a mutant form of ACOT12 lacking the START domain was not inhibited by the lipids. These results suggest that the START domain is important for regulation of ACOT12 activity by PA. We also found that PA could bind to thioesterase domain, but not to the START domain, and had no effect on ACOT12 dissociation. ACOT12 is detectable in the liver but not in hepatic cell lines such as HepG2, Hepa-1, and Fa2N-4. ACOT12 mRNA and protein levels in rat primary hepatocytes decreased following treatment with insulin. These results suggest that cytosolic acetyl-CoA levels in the liver are controlled by lipid metabolites and hormones, which result in allosteric enzymatic and transcriptional regulation of ACOT12.
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Affiliation(s)
- Yasuhiro Horibata
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
| | - Hiromi Ando
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
| | - Masahiko Itoh
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
| | - Hiroyuki Sugimoto
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan.
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29
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Hussein M, Harvatine KH, Weerasinghe WMPB, Sinclair LA, Bauman DE. Conjugated linoleic acid-induced milk fat depression in lactating ewes is accompanied by reduced expression of mammary genes involved in lipid synthesis. J Dairy Sci 2013; 96:3825-34. [PMID: 23587385 DOI: 10.3168/jds.2013-6576] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 02/28/2013] [Indexed: 01/21/2023]
Abstract
Conjugated linoleic acids (CLA) are produced during rumen biohydrogenation and exert a range of biological effects. The trans-10,cis-12 CLA isomer is a potent inhibitor of milk fat synthesis in lactating dairy cows and some aspects of the mechanism have been established. Conjugated linoleic acid-induced milk fat depression has also been observed in small ruminants and our objective was to examine the molecular mechanism in lactating ewes. Multiparous lactating ewes were fed a basal ration (0.55:0.45 concentrate-to-forage ratio; dry matter basis) and randomly allocated to 2 dietary CLA levels (n=8 ewes/treatment). Treatments were zero CLA (control) or 15 g/d of lipid-encapsulated CLA supplement containing cis-9,trans-11 and trans-10,cis-12 CLA isomers in equal proportions. Treatments were fed for 10 wk and the CLA supplement provided 1.5 g of trans-10,cis-12/d. No treatment effects were observed on milk yield or milk composition for protein or lactose at wk 10 of the study. In contrast, CLA treatment significantly decreased both milk fat percentage and milk fat yield (g/d) by about 23%. The de novo synthesized fatty acids (FA; <C16) were significantly decreased in proportion (15%) and daily yield (27%), and the proportion of preformed FA (>C16) was increased (10%) for the CLA treatment. In agreement with the reduced de novo FA synthesis, mRNA abundance of acetyl-coenzyme A carboxylase α, FA synthase, stearoyl-CoA desaturase 1, and glycerol-3-phosphate acyltransferase 6 decreased by 25 to 40% in the CLA-treated group. Conjugated linoleic acid treatment did not significantly reduce the mRNA abundance of enzymes involved in NADPH production, but the mRNA abundance for sterol regulatory element-binding factor 1 and insulin-induced gene 1, genes involved in regulation of transcription of lipogenic enzymes, was decreased by almost 30 and 55%, respectively, with CLA treatment. Furthermore, mRNA abundance of lipoprotein lipase decreased by almost 40% due to CLA treatment. In conclusion, the mechanism for CLA-induced milk fat depression in lactating ewes involved the sterol regulatory element-binding protein transcription factor family and a coordinated downregulation in transcript abundance for lipogenic enzymes involved in mammary lipid synthesis.
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Affiliation(s)
- M Hussein
- Department of Animal Science, Cornell University, Ithaca, NY 14853, USA
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Abstract
The maintenance of metabolic homeostasis requires the well-orchestrated network of several pathways of glucose, lipid and amino acid metabolism. Mitochondria integrate these pathways and serve not only as the prime site of cellular energy harvesting but also as the producer of many key metabolic intermediates. The sirtuins are a family of NAD(+)-dependent enzymes, which have a crucial role in the cellular adaptation to metabolic stress. The mitochondrial sirtuins SIRT3, SIRT4 and SIRT5 together with the nuclear SIRT1 regulate several aspects of mitochondrial physiology by controlling post-translational modifications of mitochondrial protein and transcription of mitochondrial genes. Here we discuss current knowledge how mitochondrial sirtuins and SIRT1 govern mitochondrial processes involved in different metabolic pathways.
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Affiliation(s)
- Eija Pirinen
- Laboratory for Integrative and Systems Physiology, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
- Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, Biocenter Kuopio, University of Eastern Finland, Kuopio, Finland
| | - Giuseppe Lo Sasso
- Laboratory for Integrative and Systems Physiology, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - Johan Auwerx
- Laboratory for Integrative and Systems Physiology, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
- To whom correspondence should be addressed:
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Sterols regulate 3β-hydroxysterol Δ24-reductase (DHCR24) via dual sterol regulatory elements: cooperative induction of key enzymes in lipid synthesis by Sterol Regulatory Element Binding Proteins. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:1350-60. [PMID: 22809995 DOI: 10.1016/j.bbalip.2012.07.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 06/25/2012] [Accepted: 07/09/2012] [Indexed: 01/28/2023]
Abstract
3β-Hydroxysterol Δ24-reductase (DHCR24) catalyzes a final step in cholesterol synthesis, and has been ascribed diverse functions, such as being anti-apoptotic and anti-inflammatory. How this enzyme is regulated transcriptionally by sterols is currently unclear. Some studies have suggested that its expression is regulated by Sterol Regulatory Element Binding Proteins (SREBPs) while another suggests it is through the Liver X Receptor (LXR). However, these transcription factors have opposing effects on cellular sterol levels, so it is likely that one predominates. Here we establish that sterol regulation of DHCR24 occurs predominantly through SREBP-2, and identify the particular region of the DHCR24 promoter to which SREBP-2 binds. We demonstrate that sterol regulation is mediated by two sterol regulatory elements (SREs) in the promoter of the gene, assisted by two nearby NF-Y binding sites. Moreover, we present evidence that the dual SREs work cooperatively to regulate DHCR24 expression by comparison to two known SREBP target genes, the LDL receptor with one SRE, and farnesyl-diphosphate farnesyltransferase 1, with two SREs.
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Castro LFC, Lopes-Marques M, Wilson JM, Rocha E, Reis-Henriques MA, Santos MM, Cunha I. A novel Acetyl-CoA synthetase short-chain subfamily member 1 (Acss1) gene indicates a dynamic history of paralogue retention and loss in vertebrates. Gene 2012; 497:249-55. [DOI: 10.1016/j.gene.2012.01.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 01/06/2012] [Accepted: 01/14/2012] [Indexed: 01/19/2023]
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Abstract
SIRT1 and SIRT3 are NAD+-dependent protein deacetylases that are evolutionarily conserved across mammals. These proteins are located in the cytoplasm/nucleus and mitochondria, respectively. Previous reports demonstrated that human SIRT1 deacetylates Acetyl-CoA Synthase 1 (AceCS1) in the cytoplasm, whereas SIRT3 deacetylates the homologous Acetyl-CoA Synthase 2 (AceCS2) in the mitochondria. We recently showed that 3-hydroxy-3-methylglutaryl CoA synthase 2 (HMGCS2) is deacetylated by SIRT3 in mitochondria, and we demonstrate here that SIRT1 deacetylates the homologous 3-hydroxy-3-methylglutaryl CoA synthase 1 (HMGCS1) in the cytoplasm. This novel pattern of substrate homology between cytoplasmic SIRT1 and mitochondrial SIRT3 suggests that considering evolutionary relationships between the sirtuins and their substrates may help to identify and understand the functions and interactions of this gene family. In this perspective, we take a first step by characterizing the evolutionary history of the sirtuins and these substrate families.
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Derlin T, Habermann CR, Lengyel Z, Busch JD, Wisotzki C, Mester J, Pávics L. Feasibility of 11C-acetate PET/CT for imaging of fatty acid synthesis in the atherosclerotic vessel wall. J Nucl Med 2011; 52:1848-54. [PMID: 22065877 DOI: 10.2967/jnumed.111.095869] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Fatty acids are a common constituent of atherosclerotic plaque and may be synthesized in the plaque itself. Fatty acid synthesis requires acetyl-coenzyme-A (CoA) as a main substrate, which is produced from acetate. Currently, (11)C-acetate PET/CT is used for the evaluation of malignancies. There are no data concerning its potential for the characterization of atherosclerotic plaque. Therefore, the purpose of the present study was to examine the prevalence, distribution, and topographic relationship of arterial (11)C-acetate uptake and vascular calcification in major arteries. METHODS Thirty-six patients were examined by whole-body (11)C-acetate PET/CT. Tracer uptake in various arterial segments was analyzed both qualitatively and semiquantitatively by measuring the blood-pool-corrected standardized uptake value (target-to-background ratio). CT images were used to measure calcified plaque burden. RESULTS (11)C-acetate uptake was observed at 220 sites in 32 (88.8%) of the 36 study patients, and mean target-to-background ratio was 2.5 ± 1.0. Calcified atherosclerotic lesions were observed at 483 sites in 30 (83.3%) patients. Sixty-four (29.1%) of the 220 lesions with marked (11)C-acetate uptake were colocalized with arterial calcification. However, only 13.3% of all arterial calcification sites demonstrated increased radiotracer accumulation. CONCLUSION Our data indicate the feasibility of using (11)C-acetate PET/CT for imaging of fatty acid synthesis in the atherosclerotic vessel wall. This study provides a rationale to incorporating (11)C-acetate PET into further preclinical and clinical studies to obtain new insights into fatty acid synthesis in atherosclerotic lesions and to evaluate whether it may be used to monitor pharmacologic intervention with fatty acid synthase inhibitors.
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Affiliation(s)
- Thorsten Derlin
- Department of Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg-Eppendorf, Germany.
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Sterol-regulatory-element-binding protein 2 and nuclear factor Y control human farnesyl diphosphate synthase expression and affect cell proliferation in hepatoblastoma cells. Biochem J 2010; 429:347-57. [PMID: 20450493 DOI: 10.1042/bj20091511] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
FDPS (farnesyl diphosphate synthase) catalyses the formation of farnesyl diphosphate, a key intermediate in the synthesis of cholesterol and isoprenylated cellular metabolites. FDPS is also the molecular target of nitrogen-containing bisphosphonates, which are used as bone-antiresorptive drugs in various disorders. In the present study, we characterized the sterol-response element and NF-Y (nuclear factor Y)-binding site in the human FDPS promoter. Using a luciferase assay, electrophoretic mobility-shift assay and chromatin immunoprecipitation assay, we demonstrated that these elements are responsible for the transcription of the FDPS gene, and that its transcriptional activation is mediated by SREBP-2 (sterol-regulatory-element-binding protein 2) and NF-Y. We also investigated whether sterol-mediated FDPS expression is involved in the cell proliferation induced by zoledronic acid, an FDPS inhibitor. We show that the SREBP-2- and NF-Y-mediated regulation of FDPS gene transcription modulates cell proliferation. These results suggest that SREBP-2 and NF-Y are required to trigger cell proliferation through the induction of FDPS expression and that the pharmacological action of zoledronic acid is involved in this pathway.
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Acetate metabolism and aging: An emerging connection. Mech Ageing Dev 2010; 131:511-6. [DOI: 10.1016/j.mad.2010.05.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2010] [Revised: 04/22/2010] [Accepted: 05/06/2010] [Indexed: 11/24/2022]
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Patel AB, de Graaf RA, Rothman DL, Behar KL, Mason GF. Evaluation of cerebral acetate transport and metabolic rates in the rat brain in vivo using 1H-[13C]-NMR. J Cereb Blood Flow Metab 2010; 30:1200-13. [PMID: 20125180 PMCID: PMC2879471 DOI: 10.1038/jcbfm.2010.2] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Acetate is a well-known astrocyte-specific substrate that has been used extensively to probe astrocytic function in vitro and in vivo. Analysis of amino acid turnover curves from (13)C-acetate has been limited mainly for estimation of first-order rate constants from exponential fitting or calculation of relative rates from steady-state (13)C enrichments. In this study, we used (1)H-[(13)C]-Nuclear Magnetic Resonance spectroscopy with intravenous infusion of [2-(13)C]acetate-Na(+) in vivo to measure the cerebral kinetics of acetate transport and utilization in anesthetized rats. Kinetics were assessed using a two-compartment (neuron/astrocyte) analysis of the (13)C turnover curves of glutamate-C4 and glutamine-C4 from [2-(13)C]acetate-Na(+), brain acetate levels, and the dependence of steady-state glutamine-C4 enrichment on blood acetate levels. The steady-state enrichment of glutamine-C4 increased with blood acetate concentration until 90% of plateau for plasma acetate of 4 to 5 mmol/L. Analysis assuming reversible, symmetric Michaelis-Menten kinetics for transport yielded 27+/-2 mmol/L and 1.3+/-0.3 micromol/g/min for K(t) and T(max), respectively, and for utilization, 0.17+/-0.24 mmol/L and 0.14+/-0.02 micromol/g/min for K(M_util) and V(max_util), respectively. The distribution space for acetate was only 0.32+/-0.12 mL/g, indicative of a large excluded volume. The astrocytic and neuronal tricarboxylic acid cycle fluxes were 0.37+/-0.03 micromol/g/min and 1.41+/-0.11 micromol/g/min, respectively; astrocytes thus comprised approximately 21%+/-3% of total oxidative metabolism.
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Affiliation(s)
- Anant B Patel
- Department of Diagnostic Radiology, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA.
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O-GlcNAc inhibits interaction between Sp1 and sterol regulatory element binding protein 2. Biochem Biophys Res Commun 2010; 393:314-8. [DOI: 10.1016/j.bbrc.2010.01.128] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 01/30/2010] [Indexed: 01/09/2023]
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Ishimoto K, Nakamura H, Tachibana K, Yamasaki D, Ota A, Hirano KI, Tanaka T, Hamakubo T, Sakai J, Kodama T, Doi T. Sterol-mediated regulation of human lipin 1 gene expression in hepatoblastoma cells. J Biol Chem 2009; 284:22195-22205. [PMID: 19553673 DOI: 10.1074/jbc.m109.028753] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lipin 1 plays a crucial role in lipid metabolism in adipose tissue, skeletal muscle, and liver. Its physiological role involves two cellular functions: regulation of phosphatidate phosphatase activity and regulation of fatty acid oxidation. In this study, we have demonstrated that lipin 1 gene (LPIN1) expression is regulated by cellular sterols, which are key regulators of lipid metabolism. We have also characterized the sterol-response element and nuclear factor Y-binding sites in the human LPIN1 promoter. Using a luciferase assay, electrophoretic mobility shift assay, and chromatin immunoprecipitation assay, we demonstrated that these elements are responsible for the transcription of LPIN1 gene, mediated by SREBP-1 (sterol regulatory element-binding protein 1) and nuclear factor Y. Furthermore, we investigated whether lipin 1 is involved in lipogenesis by transfection of LPIN1 small interfering RNA. We infer that sterol-mediated regulation of lipin 1 gene transcription modulates triglyceride accumulation. This modulation involves changes in the activity of phosphatidate phosphatase.
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Affiliation(s)
- Kenji Ishimoto
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871; Department of Molecular Pharmaceutical Science, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871
| | - Hiroki Nakamura
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Keisuke Tachibana
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Daisuke Yamasaki
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Akemi Ota
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871
| | - Ken-Ichi Hirano
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871
| | - Toshiya Tanaka
- Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| | - Takao Hamakubo
- Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| | - Juro Sakai
- Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| | - Tatsuhiko Kodama
- Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| | - Takefumi Doi
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871; Department of Molecular Pharmaceutical Science, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871
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Fasting-induced hypothermia and reduced energy production in mice lacking acetyl-CoA synthetase 2. Cell Metab 2009; 9:191-202. [PMID: 19187775 DOI: 10.1016/j.cmet.2008.12.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 10/15/2008] [Accepted: 12/12/2008] [Indexed: 02/08/2023]
Abstract
Acetate is activated to acetyl-CoA by acetyl-CoA synthetase 2 (AceCS2), a mitochondrial enzyme. Here, we report that the activation of acetate by AceCS2 has a specific and unique role in thermogenesis during fasting. In the skeletal muscle of fasted AceCS2(-/-) mice, ATP levels were reduced by 50% compared to AceCS2(+/+) mice. Fasted AceCS2(-/-) mice were significantly hypothermic and had reduced exercise capacity. Furthermore, when fed a low-carbohydrate diet, 4-week-old weaned AceCS2(-/-) mice also exhibited hypothermia accompanied by sustained hypoglycemia that led to a 50% mortality. Therefore, AceCS2 plays a significant role in acetate oxidation needed to generate ATP and heat. Furthermore, AceCS2(-/-) mice exhibited increased oxygen consumption and reduced weight gain on a low-carbohydrate diet. Our findings demonstrate that activation of acetate by AceCS2 plays a pivotal role in thermogenesis, especially under low-glucose or ketogenic conditions, and is crucially required for survival.
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Jiang Y, Zhang H, Dong LY, Wang D, An W. Increased hepatic UCP2 expression in rats with nonalcoholic steatohepatitis is associated with upregulation of Sp1 binding to its motif within the proximal promoter region. J Cell Biochem 2008; 105:277-89. [PMID: 18543254 DOI: 10.1002/jcb.21827] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Uncoupling protein-2 (UCP2) is a mitochondrial inner-membrane carrier protein that is involved in the control of fatty acid metabolism. To understand the mechanism of the transcriptional regulation of ucp2 in the pathogenesis of nonalcoholic steatohepatitis (NASH), we cloned 500 bp upstream of the ucp2 exon 1 from a rat liver cDNA library and identified cis-acting regulatory elements. The transcriptional start site was identified as "C," -359 bp from the ATG codon. A reporter gene assay showed that deletion of the nucleotide sequence between -264 and -60 bp resulted in a significant decrease in promoter activity in HepG2 and H4IIE cells. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) revealed that the increase in promoter activity is related to an enhanced ability of Sp1 to bind to its motifs at -84 to -61 bp within the ucp2 proximal promoter. Overexpression of exogenous Sp1 in H4IIE cells also increased the promoter activity. We demonstrated that the expression of UCP2 mRNA and protein is markedly increased in rats with nonalcoholic steatohepatitis (NASH). Coincidently, levels of Sp1 binding to -84/-61 bp were also increased. Overall, our data indicate that the Sp1-binding site located at the proximal promoter is involved in the regulation of rat UCP2 expression.
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Affiliation(s)
- Ying Jiang
- Department of Cell Biology and Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, 100069 Beijing, China
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Hepatocyte nuclear factor 4alpha contributes to thyroid hormone homeostasis by cooperatively regulating the type 1 iodothyronine deiodinase gene with GATA4 and Kruppel-like transcription factor 9. Mol Cell Biol 2008; 28:3917-31. [PMID: 18426912 DOI: 10.1128/mcb.02154-07] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Type 1 iodothyronine deiodinase (Dio1), a selenoenzyme catalyzing the bioactivation of thyroid hormone, is highly expressed in the liver. Dio1 mRNA and enzyme activity levels are markedly reduced in the livers of hepatocyte nuclear factor 4alpha (HNF4alpha)-null mice, thus accounting for its liver-specific expression. Consistent with this deficiency, serum T4 and rT3 concentrations are elevated in these mice compared with those in HNF4alpha-floxed control littermates; however, serum T3 levels are unchanged. Promoter analysis of the mouse Dio1 gene demonstrated that HNF4alpha plays a key role in the transactivation of the mouse Dio1 gene. Deletion and substitution mutation analyses demonstrated that a proximal HNF4alpha site (direct repeat 1 [TGGACAAAGGTGC]; HNF4alpha-RE) is crucial for transactivation of the mouse Dio1 gene by HNF4alpha. Mouse Dio1 is also stimulated by thyroid hormone signaling, but a direct role for thyroid hormone receptor action has not been reported. We also showed that thyroid hormone-inducible Krüppel-like factor 9 (KLF9) stimulates the mouse Dio1 promoter very efficiently through two CACCC sequences that are located on either side of HNF4alpha-RE. Furthermore, KLF9 functions together with HNF4alpha and GATA4 to synergistically activate the mouse Dio1 promoter, suggesting that Dio1 is regulated by thyroid hormone in the mouse through an indirect mechanism requiring prior KLF9 induction. In addition, we showed that physical interactions between the C-terminal zinc finger domain (Cf) of GATA4 and activation function 2 of HNF4alpha and between the basic domain adjacent to Cf of GATA4 and a C-terminal domain of KLF9 are both required for this synergistic response. Taken together, these results suggest that HNF4alpha regulates thyroid hormone homeostasis through transcriptional regulation of the mouse Dio1 gene with GATA4 and KLF9.
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Wierstra I. Sp1: emerging roles--beyond constitutive activation of TATA-less housekeeping genes. Biochem Biophys Res Commun 2008; 372:1-13. [PMID: 18364237 DOI: 10.1016/j.bbrc.2008.03.074] [Citation(s) in RCA: 275] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 03/17/2008] [Indexed: 01/21/2023]
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Morgan XC, Ni S, Miranker DP, Iyer VR. Predicting combinatorial binding of transcription factors to regulatory elements in the human genome by association rule mining. BMC Bioinformatics 2007; 8:445. [PMID: 18005433 PMCID: PMC2211755 DOI: 10.1186/1471-2105-8-445] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Accepted: 11/15/2007] [Indexed: 12/20/2022] Open
Abstract
Background Cis-acting transcriptional regulatory elements in mammalian genomes typically contain specific combinations of binding sites for various transcription factors. Although some cis-regulatory elements have been well studied, the combinations of transcription factors that regulate normal expression levels for the vast majority of the 20,000 genes in the human genome are unknown. We hypothesized that it should be possible to discover transcription factor combinations that regulate gene expression in concert by identifying over-represented combinations of sequence motifs that occur together in the genome. In order to detect combinations of transcription factor binding motifs, we developed a data mining approach based on the use of association rules, which are typically used in market basket analysis. We scored each segment of the genome for the presence or absence of each of 83 transcription factor binding motifs, then used association rule mining algorithms to mine this dataset, thus identifying frequently occurring pairs of distinct motifs within a segment. Results Support for most pairs of transcription factor binding motifs was highly correlated across different chromosomes although pair significance varied. Known true positive motif pairs showed higher association rule support, confidence, and significance than background. Our subsets of high-confidence, high-significance mined pairs of transcription factors showed enrichment for co-citation in PubMed abstracts relative to all pairs, and the predicted associations were often readily verifiable in the literature. Conclusion Functional elements in the genome where transcription factors bind to regulate expression in a combinatorial manner are more likely to be predicted by identifying statistically and biologically significant combinations of transcription factor binding motifs than by simply scanning the genome for the occurrence of binding sites for a single transcription factor.
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Affiliation(s)
- Xochitl C Morgan
- Institute for Cellular and Molecular Biology and Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712-0159, USA.
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Smith TM, Gilliland K, Clawson GA, Thiboutot D. IGF-1 induces SREBP-1 expression and lipogenesis in SEB-1 sebocytes via activation of the phosphoinositide 3-kinase/Akt pathway. J Invest Dermatol 2007; 128:1286-93. [PMID: 17989724 DOI: 10.1038/sj.jid.5701155] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Understanding the factors that regulate sebum production is important in identifying therapeutic targets for acne therapy. Insulin and IGF-1 stimulate sebaceous gland lipogenesis. IGF-1 increases expression of sterol response element-binding protein-1 (SREBP-1), a transcription factor that regulates numerous genes involved in lipid biosynthesis. SREBP-1 expression, in turn, stimulates lipogenesis in sebocytes. The goal of this study was to identify the intracellular signaling pathway(s) that transduces the lipogenic signal initiated by IGF-1. Sebocytes were treated with IGF-1 and assayed for activation of the phosphoinositide 3-kinase (PI3-K) pathway and of the three major arms of the mitogen-activated protein kinase (MAPK) pathway (MAPK/extracellular signal-regulated kinase (ERK), p38 MAPK, and stress-activated protein kinase/c-Jun-N terminal kinase). IGF-1 activated the MAPK/ERK and PI-3K pathways. Using specific inhibitors of each pathway, we found that the increase in expression of SREBP-1 induced by IGF-1 was blocked in the presence of the PI3-K inhibitor but not in the presence of the MAPK/ERK inhibitor. Furthermore, inhibition of the PI3-K pathway also blocked the IGF-1-induced transcription of SREBP target genes and sebocyte lipogenesis. These data indicate that IGF-1 transmits its lipogenic signal in sebocytes through activation of Akt. Specific targeted interruption of this pathway in the sebaceous gland could be a desirable approach to reducing sebum production and improving acne.
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Affiliation(s)
- Terry M Smith
- The Jake Gittlen Cancer Research Foundation, Hershey, Pennsylvania, USA
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Iguchi H, Urashima Y, Inagaki Y, Ikeda Y, Okamura M, Tanaka T, Uchida A, Yamamoto TT, Kodama T, Sakai J. SOX6 Suppresses Cyclin D1 Promoter Activity by Interacting with β-Catenin and Histone Deacetylase 1, and Its Down-regulation Induces Pancreatic β-Cell Proliferation. J Biol Chem 2007; 282:19052-61. [PMID: 17412698 DOI: 10.1074/jbc.m700460200] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sex-determining region Y-box (SOX) 6 negatively regulates glucose-stimulated insulin secretion from beta-cells and is a down-regulated transcription factor in the pancreatic islet cells of hyperinsulinemic obese mice. To determine the contribution of SOX6 to insulin resistance, we analyzed the effects of SOX6 on cell proliferation. Small interfering RNA-mediated attenuation of SOX6 expression stimulated the proliferation of insulinoma INS-1E and NIH-3T3 cells, whereas retroviral overexpression resulted in inhibition of cell growth. Quantitative real time-PCR analysis revealed that the levels of cyclin D1 transcripts were markedly decreased by SOX6 overexpression. Luciferase-reporter assay with beta-catenin showed that SOX6 suppresses cyclin D1 promoter activities. In vitro binding experiments showed that the LZ/Q domain of SOX6 physically interacts with armadillo repeats 1-4 of beta-catenin. Furthermore, chromatin immunoprecipitation assay revealed that increased SOX6 expression significantly reduced the levels of acetylated histones H3 and H4 at the cyclin D1 promoter. By using a histone deacetylase (HDAC) inhibitor and co-immunoprecipitation analysis, we showed that SOX6 suppressed cyclin D1 activities by interacting withbeta-catenin and HDAC1. The data presented suggest that SOX6 may be an important factor in obesity-related insulin resistance.
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Affiliation(s)
- Haruhisa Iguchi
- Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
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Satoh SI, Masatoshi S, Shou Z, Yamamoto T, Ishigure T, Semii A, Yamada K, Noguchi T. Identification of cis-regulatory elements and trans-acting proteins of the rat carbohydrate response element binding protein gene. Arch Biochem Biophys 2007; 461:113-22. [PMID: 17418800 DOI: 10.1016/j.abb.2007.02.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 02/26/2007] [Accepted: 02/27/2007] [Indexed: 11/30/2022]
Abstract
Carbohydrate response element binding protein (ChREBP) is a transcription factor that activates liver glycolytic and lipogenetic enzyme genes in response to high carbohydrate diet. Here we report the transcriptional regulatory mechanisms for the rat ChREBP gene. Firstly, we determined the transcription initiation site and the nucleotide sequences of the rat ChREBP promoter region encompassing approximately 900bp from the ATG initiation codon. Reporter gene assays demonstrated that the major positive regulatory region exists in the nucleotide sequence between -163 and -32 of the ChREBP gene. This region contains a cluster of putative transcription factor binding elements that consist of two specificity protein 1 (Sp1) binding sites (-66 to -50 and -93 to -78), a sterol regulatory element (-101 to -110), and two nuclear factor-Y (NF-Y) binding sites (-23 to -19 and -131 to -127). Mutations introduced into these sites caused marked reduction of ChREBP promoter activities. Functional synergisms were observed between Sp1/NF-Y and Sp1/sterol regulatory element-binding protein. Additionally, electrophoretic mobility shift assays and chromatin immunoprecipitation assays demonstrated that these factors bound to these elements. Thus, we conclude that functional synergisms between these transcription factors are critical for ChREBP gene transcription.
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Affiliation(s)
- Shin-Ichi Satoh
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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48
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Sumi K, Tanaka T, Uchida A, Magoori K, Urashima Y, Ohashi R, Ohguchi H, Okamura M, Kudo H, Daigo K, Maejima T, Kojima N, Sakakibara I, Jiang S, Hasegawa G, Kim I, Osborne TF, Naito M, Gonzalez FJ, Hamakubo T, Kodama T, Sakai J. Cooperative interaction between hepatocyte nuclear factor 4 alpha and GATA transcription factors regulates ATP-binding cassette sterol transporters ABCG5 and ABCG8. Mol Cell Biol 2007; 27:4248-60. [PMID: 17403900 PMCID: PMC1900057 DOI: 10.1128/mcb.01894-06] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cholesterol homeostasis is maintained by coordinate regulation of cholesterol synthesis and its conversion to bile acids in the liver. The excretion of cholesterol from liver and intestine is regulated by ATP-binding cassette half-transporters ABCG5 and ABCG8. The genes for these two proteins are closely linked and divergently transcribed from a common intergenic promoter region. Here, we identified a binding site for hepatocyte nuclear factor 4alpha (HNF4alpha) in the ABCG5/ABCG8 intergenic promoter, through which HNF4alpha strongly activated the expression of a reporter gene in both directions. The HNF4alpha-responsive element is flanked by two conserved GATA boxes that were also required for stimulation by HNF4alpha. GATA4 and GATA6 bind to the GATA boxes, coexpression of GATA4 and HNF4alpha leads to a striking synergistic activation of both the ABCG5 and the ABCG8 promoters, and binding sites for HNF4alpha and GATA were essential for maximal synergism. We also show that HNF4alpha, GATA4, and GATA6 colocalize in the nuclei of HepG2 cells and that a physical interaction between HNF4alpha and GATA4 is critical for the synergistic response. This is the first demonstration that HNF4alpha acts synergistically with GATA factors to activate gene expression in a bidirectional fashion.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily G, Member 5
- ATP Binding Cassette Transporter, Subfamily G, Member 8
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/metabolism
- Adenoviridae/genetics
- Amino Acid Motifs
- Amino Acid Sequence
- Base Sequence
- Binding Sites
- Carcinoma, Hepatocellular/metabolism
- Carcinoma, Hepatocellular/pathology
- Cell Line
- Cell Line, Tumor
- Consensus Sequence
- Conserved Sequence
- GATA4 Transcription Factor/genetics
- GATA4 Transcription Factor/metabolism
- GATA6 Transcription Factor/genetics
- GATA6 Transcription Factor/metabolism
- Gene Deletion
- Genes, Reporter
- Hepatocyte Nuclear Factor 4/chemistry
- Hepatocyte Nuclear Factor 4/metabolism
- Humans
- Lipoproteins/genetics
- Lipoproteins/metabolism
- Liver Neoplasms/metabolism
- Liver Neoplasms/pathology
- Luciferases/metabolism
- Molecular Sequence Data
- Oligonucleotide Array Sequence Analysis
- Promoter Regions, Genetic
- Protein Binding
- Protein Structure, Tertiary
- RNA Interference
- Sequence Homology, Amino Acid
- Sequence Homology, Nucleic Acid
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Affiliation(s)
- Koichi Sumi
- Laboratory of Systems Biology and Medicine, Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, Japan
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49
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Pedersen TÅ, Bereshchenko O, Garcia-Silva S, Ermakova O, Kurz E, Mandrup S, Porse BT, Nerlov C. Distinct C/EBPalpha motifs regulate lipogenic and gluconeogenic gene expression in vivo. EMBO J 2007; 26:1081-93. [PMID: 17290224 PMCID: PMC1852842 DOI: 10.1038/sj.emboj.7601563] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Accepted: 12/20/2006] [Indexed: 01/04/2023] Open
Abstract
The C/EBPalpha transcription factor regulates hepatic nitrogen, glucose, lipid and iron metabolism. However, how it is able to independently control these processes is not known. Here, we use mouse knock-in mutagenesis to identify C/EBPalpha domains that specifically regulate hepatic gluconeogenesis and lipogenesis. In vivo deletion of a proline-histidine rich domain (PHR), dephosphorylated at S193 by insulin signaling, dysregulated genes involved in the generation of acetyl-CoA and NADPH for triglyceride synthesis and led to increased hepatic lipogenesis. These promoters bound SREBP-1 as well as C/EBPalpha, and the PHR was required for C/EBPalpha-SREBP transcriptional synergy. In contrast, the highly conserved C/EBPalpha CR4 domain was found to undergo liver-specific dephosphorylation of residues T222 and T226 upon fasting, and alanine mutation of these residues upregulated the hepatic expression of the gluconeogenic G6Pase and PEPCK mRNAs, but not PGC-1alpha, leading to glucose intolerance. Our results show that pathway-specific metabolic regulation can be achieved through a single transcription factor containing context-sensitive regulatory domains, and indicate C/EBPalpha phosphorylation as a PGC-1alpha-independent mechanism for regulating hepatic gluconeogenesis.
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Affiliation(s)
- Thomas Å Pedersen
- EMBL Mouse Biology Unit, Monterotondo, Italy
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | | | | | | | - Elke Kurz
- EMBL Mouse Biology Unit, Monterotondo, Italy
| | - Susanne Mandrup
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Bo T Porse
- Laboratory of Gene Therapy Research, Copenhagen University Hospital, Copenhagen Ø, Denmark
| | - Claus Nerlov
- EMBL Mouse Biology Unit, Monterotondo, Italy
- Mouse Biology Unit, EMBL, via Ramarini 32, 00016 Monterotondo, Italy. Tel.: +39 06 9009 1218; Fax: +39 06 9009 1272; E-mail:
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50
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Griffin MJ, Wong RHF, Pandya N, Sul HS. Direct interaction between USF and SREBP-1c mediates synergistic activation of the fatty-acid synthase promoter. J Biol Chem 2006; 282:5453-67. [PMID: 17197698 DOI: 10.1074/jbc.m610566200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
To understand the molecular mechanisms underlying transcriptional activation of fatty-acid synthase (FAS), we examined the relationship between upstream stimulatory factor (USF) and SREBP-1c, two transcription factors that we have shown previously to be critical for FAS induction by feeding/insulin. Here, by using a combination of tandem affinity purification and coimmunoprecipitation, we demonstrate, for the first time, that USF and SREBP-1 interact in vitro and in vivo. Glutathione S-transferase pulldown experiments with various USF and sterol regulatory element-binding protein (SREBP) deletion constructs indicate that the basic helix-loop-helix domain of USF interacts directly with the basic helix-loop-helix and an N-terminal region of SREBP-1c. Furthermore, cotransfection of USF and SREBP-1c with an FAS promoter-luciferase reporter construct in Drosophila SL2 cells results in highly synergistic activation of the FAS promoter. We also show similar cooperative activation of the mitochondrial glycerol-3-phosphate acyltransferase promoter by USF and SREBP-1c. Chromatin immunoprecipitation analysis of mouse liver demonstrates that USF binds constitutively to the mitochondrial glycerol 3-phosphate acyltransferase promoter during fasting/refeeding in vivo, whereas binding of SREBP-1 is observed only during refeeding, in a manner identical to that of the FAS promoter. In addition, we show that the synergy we have observed depends on the activation domains of both proteins and that mutated USF or SREBP lacking the N-terminal activation domain could inhibit the transactivation of the other. Closely positioned E-boxes and sterol regulatory elements found in the promoters of several lipogenic genes suggest a common mechanism of induction by feeding/insulin.
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Affiliation(s)
- Michael J Griffin
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720, USA
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