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Sato T, Umebayashi S, Senoo N, Akahori T, Ichida H, Miyoshi N, Yoshida T, Sugiura Y, Goto-Inoue N, Kawana H, Shindou H, Baba T, Maemoto Y, Kamei Y, Shimizu T, Aoki J, Miura S. LPGAT1/LPLAT7 regulates acyl chain profiles at the sn-1 position of phospholipids in murine skeletal muscles. J Biol Chem 2023:104848. [PMID: 37217003 PMCID: PMC10285227 DOI: 10.1016/j.jbc.2023.104848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 05/17/2023] [Indexed: 05/24/2023] Open
Abstract
Skeletal muscle consists of both fast- and slow-twitch fibers. Phospholipids are important structural components of cellular membranes, and the diversity of their fatty acid composition affects membrane fluidity and permeability. Although some studies have shown that acyl chain species in phospholipids differ among various muscle fiber types, the mechanisms underlying these differences are unclear. To investigate this, we analyzed phosphatidylcholine (PC) and phosphatidylethanolamine (PE) molecules in the murine extensor digitorum longus (EDL; fast-twitch) and soleus (slow-twitch) muscles. In the EDL muscle, the vast majority (93.6%) of PC molecules was palmitate-containing PC (16:0-PC), whereas in the soleus muscle, in addition to 16:0-PC, 27.9% of PC molecules was stearate-containing PC (18:0-PC). Most palmitate and stearate were bound at the sn-1 position of 16:0- and 18:0-PC, respectively, and 18:0-PC was found in type I and IIa fibers. The amount of 18:0-PE was higher in the soleus than in the EDL muscle. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) increased the amount of 18:0-PC in the EDL. Lysophosphatidylglycerol acyltransferase 1 (LPGAT1) was highly expressed in the soleus compared with that in the EDL muscle and was upregulated by PGC-1α. LPGAT1 knockout decreased the incorporation of stearate into PC and PE in vitro and ex vivo and the amount of 18:0-PC and 18:0-PE in murine skeletal muscle with an increase in the level of 16:0-PC and 16:0-PE. Moreover, knocking out LPGAT1 decreased the amount of stearate-containing-phosphatidylserine (18:0-PS), suggesting that LPGAT1 regulated the acyl chain profiles of phospholipids, namely PC, PE, and PS, in the skeletal muscle.
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Affiliation(s)
- Tomoki Sato
- Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Shuhei Umebayashi
- Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Nanami Senoo
- Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Takumi Akahori
- Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Hiyori Ichida
- Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Noriyuki Miyoshi
- Laboratory of Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Takuya Yoshida
- Laboratory of Clinical Nutrition, Graduate School of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto, 862-8502, Japan
| | - Yuki Sugiura
- Department of Biochemistry, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Naoko Goto-Inoue
- Department of Marine Science and Resources, College of Bioresource Sciences, Nihon University, Fujisawa, 252-0880, Japan
| | - Hiroki Kawana
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; Advanced Research & Development Programs for Medical Innovation (AMED-LEAP), Chiyoda-ku, Tokyo, 100-0004, Japan
| | - Hideo Shindou
- Department of Lipid Life Science, National Center for Global Health and Medicine, Tokyo 162-8655, Japan; Department of Lipid Medical Science, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Takashi Baba
- Laboratory of Molecular Cell Biology, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, 192-0392, Japan
| | - Yuki Maemoto
- Laboratory of Molecular Cell Biology, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, 192-0392, Japan
| | - Yasutomi Kamei
- Laboratory of Molecular Nutrition, Graduate School of Environmental and Life Science, Kyoto Prefectural University, Kyoto, 606-8522, Japan
| | - Takao Shimizu
- Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo 162-8655, Japan; Institute of Microbial Chemistry, Tokyo, 141-0021, Japan
| | - Junken Aoki
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; Advanced Research & Development Programs for Medical Innovation (AMED-LEAP), Chiyoda-ku, Tokyo, 100-0004, Japan
| | - Shinji Miura
- Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
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Tao LC, Wang TT, Zheng L, Hua F, Li JJ. The Role of Mitochondrial Biogenesis Dysfunction in Diabetic Cardiomyopathy. Biomol Ther (Seoul) 2022; 30:399-408. [PMID: 35410981 PMCID: PMC9424338 DOI: 10.4062/biomolther.2021.192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/28/2022] [Accepted: 02/22/2022] [Indexed: 11/26/2022] Open
Abstract
Diabetic cardiomyopathy (DCM) is described as abnormalities of myocardial structure and function in diabetic patients without other well-established cardiovascular factors. Although multiple pathological mechanisms involving in this unique myocardial disorder, mitochondrial dysfunction may play an important role in its development of DCM. Recently, considerable progresses have suggested that mitochondrial biogenesis is a tightly controlled process initiating mitochondrial generation and maintaining mitochondrial function, appears to be associated with DCM. Nonetheless, an outlook on the mechanisms and clinical relevance of dysfunction in mitochondrial biogenesis among patients with DCM is not completely understood. In this review, hence, we will summarize the role of mitochondrial biogenesis dysfunction in the development of DCM, especially the molecular underlying mechanism concerning the signaling pathways beyond the stimulation and inhibition of mitochondrial biogenesis. Additionally, the evaluations and potential therapeutic strategies regarding mitochondrial biogenesis dysfunction in DCM is also presented.
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Affiliation(s)
- Li-Chan Tao
- The Third Affiliated Hospital of Soochow University, Juqian Road, Changzhou 213000, China
| | - Ting-Ting Wang
- The Third Affiliated Hospital of Soochow University, Juqian Road, Changzhou 213000, China
| | - Lu Zheng
- The Third Affiliated Hospital of Soochow University, Juqian Road, Changzhou 213000, China
| | - Fei Hua
- The Third Affiliated Hospital of Soochow University, Juqian Road, Changzhou 213000, China
| | - Jian-Jun Li
- State Key Laboratory of Cardiovascular Diseases, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
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Patel BV, Yao F, Howenstine A, Takenaka R, Hyatt JA, Sears KE, Shewchuk BM. Emergent Coordination of the CHKB and CPT1B Genes in Eutherian Mammals: Implications for the Origin of Brown Adipose Tissue. J Mol Biol 2020; 432:6127-6145. [PMID: 33058877 DOI: 10.1016/j.jmb.2020.09.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 11/17/2022]
Abstract
Mitochondrial fatty acid oxidation (FAO) contributes to the proton motive force that drives ATP synthesis in many mammalian tissues. In eutherian (placental) mammals, brown adipose tissue (BAT) can also dissipate this proton gradient through uncoupling protein 1 (UCP1) to generate heat, but the evolutionary events underlying the emergence of BAT are unknown. An essential step in FAO is the transport of cytoplasmic long chain acyl-coenzyme A (acyl-CoA) into the mitochondrial matrix, which requires the action of carnitine palmitoyltransferase 1B (CPT1B) in striated muscle and BAT. In eutherians, the CPT1B gene is closely linked to the choline kinase beta (CHKB) gene, which is transcribed from the same DNA strand and terminates just upstream of CPT1B. CHKB is a rate-limiting enzyme in the synthesis of phosphatidylcholine (PC), a predominant mitochondrial membrane phospholipid, suggesting that the coordinated expression of CHKB and CPT1B may cooperatively enhance mitochondrial FAO. The present findings show that transcription of the eutherian CHKB and CPT1B genes is linked within a unitary epigenetic domain targeted to the CHKB gene, and that that this regulatory linkage appears to have resulted from an intergenic deletion in eutherians that significantly altered the distribution of CHKB and CPT1B expression. Informed by the timing of this event relative to the emergence of BAT, the phylogeny of CHKB-CPT1B synteny, and the insufficiency of UCP1 to account for eutherian BAT, these data support a mechanism for the emergence of BAT based on the acquisition of a novel capacity for adipocyte FAO in a background of extant UCP1.
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Affiliation(s)
- Bhavin V Patel
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States
| | - Fanrong Yao
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States
| | - Aidan Howenstine
- Department of Ecology & Evolutionary Biology, College of Life Sciences, University of California Los Angeles, Los Angeles, CA 90095, United States
| | - Risa Takenaka
- Department of Ecology & Evolutionary Biology, College of Life Sciences, University of California Los Angeles, Los Angeles, CA 90095, United States
| | - Jacob A Hyatt
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States
| | - Karen E Sears
- Department of Ecology & Evolutionary Biology, College of Life Sciences, University of California Los Angeles, Los Angeles, CA 90095, United States
| | - Brian M Shewchuk
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States.
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Laurila PP, Soronen J, Kooijman S, Forsström S, Boon MR, Surakka I, Kaiharju E, Coomans CP, Van Den Berg SAA, Autio A, Sarin AP, Kettunen J, Tikkanen E, Manninen T, Metso J, Silvennoinen R, Merikanto K, Ruuth M, Perttilä J, Mäkelä A, Isomi A, Tuomainen AM, Tikka A, Ramadan UA, Seppälä I, Lehtimäki T, Eriksson J, Havulinna A, Jula A, Karhunen PJ, Salomaa V, Perola M, Ehnholm C, Lee-Rueckert M, Van Eck M, Roivainen A, Taskinen MR, Peltonen L, Mervaala E, Jalanko A, Hohtola E, Olkkonen VM, Ripatti S, Kovanen PT, Rensen PCN, Suomalainen A, Jauhiainen M. USF1 deficiency activates brown adipose tissue and improves cardiometabolic health. Sci Transl Med 2016; 8:323ra13. [PMID: 26819196 DOI: 10.1126/scitranslmed.aad0015] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
USF1 (upstream stimulatory factor 1) is a transcription factor associated with familial combined hyperlipidemia and coronary artery disease in humans. However, whether USF1 is beneficial or detrimental to cardiometabolic health has not been addressed. By inactivating USF1 in mice, we demonstrate protection against diet-induced dyslipidemia, obesity, insulin resistance, hepatic steatosis, and atherosclerosis. The favorable plasma lipid profile, including increased high-density lipoprotein cholesterol and decreased triglycerides, was coupled with increased energy expenditure due to activation of brown adipose tissue (BAT). Usf1 inactivation directs triglycerides from the circulation to BAT for combustion via a lipoprotein lipase-dependent mechanism, thus enhancing plasma triglyceride clearance. Mice lacking Usf1 displayed increased BAT-facilitated, diet-induced thermogenesis with up-regulation of mitochondrial respiratory chain complexes, as well as increased BAT activity even at thermoneutrality and after BAT sympathectomy. A direct effect of USF1 on BAT activation was demonstrated by an amplified adrenergic response in brown adipocytes after Usf1 silencing, and by augmented norepinephrine-induced thermogenesis in mice lacking Usf1. In humans, individuals carrying SNP (single-nucleotide polymorphism) alleles that reduced USF1 mRNA expression also displayed a beneficial cardiometabolic profile, featuring improved insulin sensitivity, a favorable lipid profile, and reduced atherosclerosis. Our findings identify a new molecular link between lipid metabolism and energy expenditure, and point to the potential of USF1 as a therapeutic target for cardiometabolic disease.
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Affiliation(s)
- Pirkka-Pekka Laurila
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland. Department of Medical Genetics, University of Helsinki, Helsinki FI-00014, Finland. Institute for Molecular Medicine Finland, FIMM, Helsinki FI-00251, Finland.
| | - Jarkko Soronen
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland. Institute for Molecular Medicine Finland, FIMM, Helsinki FI-00251, Finland. Minerva Foundation Institute for Medical Research, Helsinki FI-00290, Finland
| | - Sander Kooijman
- Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden 2333 ZA, Netherlands. Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden 2333 ZA, Netherlands
| | - Saara Forsström
- Molecular Neurology, Research Programs Unit, University of Helsinki, Helsinki FI-00014, Finland
| | - Mariëtte R Boon
- Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden 2333 ZA, Netherlands. Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden 2333 ZA, Netherlands
| | - Ida Surakka
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland. Institute for Molecular Medicine Finland, FIMM, Helsinki FI-00251, Finland
| | - Essi Kaiharju
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland
| | - Claudia P Coomans
- Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden 2333 ZA, Netherlands. Department of Molecular Cell Biology, Leiden University Medical Center, Leiden 2333 ZA, Netherlands
| | | | - Anu Autio
- Turku PET Centre, University of Turku and Turku University Hospital, Turku FI-20520, Finland
| | - Antti-Pekka Sarin
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland. Institute for Molecular Medicine Finland, FIMM, Helsinki FI-00251, Finland
| | - Johannes Kettunen
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland. Institute for Molecular Medicine Finland, FIMM, Helsinki FI-00251, Finland. Computational Medicine, Institute of Health Sciences, University of Oulu and Oulu University Hospital, Oulu FI-90014, Finland
| | - Emmi Tikkanen
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland. Institute for Molecular Medicine Finland, FIMM, Helsinki FI-00251, Finland. Hjelt Institute, University of Helsinki, Helsinki FI-00014, Finland
| | - Tuula Manninen
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland. Molecular Neurology, Research Programs Unit, University of Helsinki, Helsinki FI-00014, Finland
| | - Jari Metso
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland
| | | | - Krista Merikanto
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland
| | - Maija Ruuth
- Wihuri Research Institute, Helsinki FI-00290, Finland
| | - Julia Perttilä
- Minerva Foundation Institute for Medical Research, Helsinki FI-00290, Finland
| | - Anne Mäkelä
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu FI-90014, Finland
| | - Ayaka Isomi
- Hiroshima University, Hiroshima 730-0053, Japan
| | - Anita M Tuomainen
- Institute of Dentistry, University of Helsinki, Helsinki FI-00014, Finland
| | - Anna Tikka
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland
| | - Usama Abo Ramadan
- Experimental MRI Laboratory, Department of Neurology, Helsinki University Central Hospital, Helsinki FI-00290, Finland
| | - Ilkka Seppälä
- Department of Clinical Chemistry, Fimlab Laboratories, and Tampere University School of Medicine, Tampere FI-33014, Finland
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Fimlab Laboratories, and Tampere University School of Medicine, Tampere FI-33014, Finland
| | - Johan Eriksson
- Department of Health, National Institute for Health and Welfare, Helsinki FI-00271, Finland. Folkhälsan Research Centre, Helsinki FI-00251, Finland. Unit of General Practice, Helsinki University Central Hospital, Helsinki FI-00290, Finland. Department of General Practice and Primary Health Care, University of Helsinki, Helsinki FI-00014, Finland
| | - Aki Havulinna
- Department of Health, National Institute for Health and Welfare, Helsinki FI-00271, Finland
| | - Antti Jula
- Department of Health, National Institute for Health and Welfare, Helsinki FI-00271, Finland
| | - Pekka J Karhunen
- Department of Clinical Chemistry, Fimlab Laboratories, and Tampere University School of Medicine, Tampere FI-33014, Finland
| | - Veikko Salomaa
- Department of Health, National Institute for Health and Welfare, Helsinki FI-00271, Finland
| | - Markus Perola
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland
| | - Christian Ehnholm
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland
| | | | - Miranda Van Eck
- Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden 2333 ZA, Netherlands
| | - Anne Roivainen
- Turku PET Centre, University of Turku and Turku University Hospital, Turku FI-20520, Finland. Turku Center for Disease Modeling, University of Turku, Turku FI-20520, Finland
| | - Marja-Riitta Taskinen
- Diabetes and Obesity Research Program, University of Helsinki, Helsinki FI-00014, Finland
| | | | - Eero Mervaala
- Institute of Biomedicine, University of Helsinki, Helsinki FI-00014, Finland
| | - Anu Jalanko
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland
| | - Esa Hohtola
- Department of Genetics and Physiology, University of Oulu, Oulu FI-90014, Finland
| | - Vesa M Olkkonen
- Minerva Foundation Institute for Medical Research, Helsinki FI-00290, Finland
| | - Samuli Ripatti
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland. Institute for Molecular Medicine Finland, FIMM, Helsinki FI-00251, Finland. Hjelt Institute, University of Helsinki, Helsinki FI-00014, Finland. Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | | | - Patrick C N Rensen
- Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden 2333 ZA, Netherlands. Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden 2333 ZA, Netherlands
| | - Anu Suomalainen
- Molecular Neurology, Research Programs Unit, University of Helsinki, Helsinki FI-00014, Finland. Department of Neurology, Helsinki University Central Hospital, Helsinki FI-00290, Finland. Neuroscience Center, University of Helsinki, Helsinki FI-00014, Finland
| | - Matti Jauhiainen
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki FI-00251, Finland.
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Maples JM, Brault JJ, Witczak CA, Park S, Hubal MJ, Weber TM, Houmard JA, Shewchuk BM. Differential epigenetic and transcriptional response of the skeletal muscle carnitine palmitoyltransferase 1B (CPT1B) gene to lipid exposure with obesity. Am J Physiol Endocrinol Metab 2015; 309:E345-56. [PMID: 26058865 PMCID: PMC4537922 DOI: 10.1152/ajpendo.00505.2014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 06/01/2015] [Indexed: 01/09/2023]
Abstract
The ability to increase fatty acid oxidation (FAO) in response to dietary lipid is impaired in the skeletal muscle of obese individuals, which is associated with a failure to coordinately upregulate genes involved with FAO. While the molecular mechanisms contributing to this metabolic inflexibility are not evident, a possible candidate is carnitine palmitoyltransferase-1B (CPT1B), which is a rate-limiting step in FAO. The present study was undertaken to determine if the differential response of skeletal muscle CPT1B gene transcription to lipid between lean and severely obese subjects is linked to epigenetic modifications (DNA methylation and histone acetylation) that impact transcriptional activation. In primary human skeletal muscle cultures the expression of CPT1B was blunted in severely obese women compared with their lean counterparts in response to lipid, which was accompanied by changes in CpG methylation, H3/H4 histone acetylation, and peroxisome proliferator-activated receptor-δ and hepatocyte nuclear factor 4α transcription factor occupancy at the CPT1B promoter. Methylation of specific CpG sites in the CPT1B promoter that correlated with CPT1B transcript level blocked the binding of the transcription factor upstream stimulatory factor, suggesting a potential causal mechanism. These findings indicate that epigenetic modifications may play important roles in the regulation of CPT1B in response to a physiologically relevant lipid mixture in human skeletal muscle, a major site of fatty acid catabolism, and that differential DNA methylation may underlie the depressed expression of CPT1B in response to lipid, contributing to the metabolic inflexibility associated with severe obesity.
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Affiliation(s)
- Jill M Maples
- Human Performance Laboratory, East Carolina University, Greenville, North Carolina; Department of Kinesiology, East Carolina University, Greenville, North Carolina; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina
| | - Jeffrey J Brault
- Human Performance Laboratory, East Carolina University, Greenville, North Carolina; Department of Kinesiology, East Carolina University, Greenville, North Carolina; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina; Department of Biochemistry and Molecular Biology, East Carolina University, Greenville, North Carolina; Department of Physiology, East Carolina University, Greenville, North Carolina; and
| | - Carol A Witczak
- Human Performance Laboratory, East Carolina University, Greenville, North Carolina; Department of Kinesiology, East Carolina University, Greenville, North Carolina; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina; Department of Biochemistry and Molecular Biology, East Carolina University, Greenville, North Carolina; Department of Physiology, East Carolina University, Greenville, North Carolina; and
| | - Sanghee Park
- Human Performance Laboratory, East Carolina University, Greenville, North Carolina; Department of Kinesiology, East Carolina University, Greenville, North Carolina; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina
| | - Monica J Hubal
- Department of Integrative Systems Biology, Children's National Medical Center, Washington, DC
| | - Todd M Weber
- Human Performance Laboratory, East Carolina University, Greenville, North Carolina; Department of Kinesiology, East Carolina University, Greenville, North Carolina; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina
| | - Joseph A Houmard
- Human Performance Laboratory, East Carolina University, Greenville, North Carolina; Department of Kinesiology, East Carolina University, Greenville, North Carolina; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina
| | - Brian M Shewchuk
- Department of Biochemistry and Molecular Biology, East Carolina University, Greenville, North Carolina;
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Schwind L, Zimmer AD, Götz C, Montenarh M. CK2 phosphorylation of C/EBPδ regulates its transcription factor activity. Int J Biochem Cell Biol 2015; 61:81-9. [PMID: 25680545 DOI: 10.1016/j.biocel.2015.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 01/26/2015] [Accepted: 02/03/2015] [Indexed: 01/25/2023]
Abstract
Protein kinase CK2 plays an essential role in cell viability in lower and higher eukaryotes. As a global regulator it phosphorylates and thereby regulates a broad array of cellular targets including a large number of transcription factors. Here, we have identified the CCAAT/enhancer binding protein δ (C/EBPδ) as a new substrate for CK2. Using point mutants of C/EBPδ the major phosphorylation site for CK2 was mapped to serine 57, which is located within the transactivation domain of C/EBPδ. For proper functioning as a transcription factor C/EBPδ has to be translocated into the nucleus where it forms heterodimers with other members of the C/EBP family of proteins and ATF4. Here, we found that CK2 phosphorylation does neither influence the subcellular localization of C/EBPδ nor its interaction with C/EBPβ, but rather does CK2 phosphorylation modulate the transcriptional activity of C/EBPδ. Moreover, we found that CK2 bound to C/EBPδ, which might help to target CK2 to the transcriptional machinery where it can phosphorylate other transcription factors or co-activators.
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Affiliation(s)
- Lisa Schwind
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, D-66424 Homburg, Germany
| | - Andreas D Zimmer
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, D-66424 Homburg, Germany
| | - Claudia Götz
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, D-66424 Homburg, Germany
| | - Mathias Montenarh
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, D-66424 Homburg, Germany.
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7
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Gao S, McMillan RP, Zhu Q, Lopaschuk GD, Hulver MW, Butler AA. Therapeutic effects of adropin on glucose tolerance and substrate utilization in diet-induced obese mice with insulin resistance. Mol Metab 2015; 4:310-24. [PMID: 25830094 PMCID: PMC4354928 DOI: 10.1016/j.molmet.2015.01.005] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 01/06/2015] [Accepted: 01/09/2015] [Indexed: 12/11/2022] Open
Abstract
Objective The peptide hormone adropin regulates fuel selection preferences in skeletal muscle under fed and fasted conditions. Here, we investigated whether adropin treatment can ameliorate the dysregulation of fuel substrate metabolism, and improve aspects of glucose homeostasis in diet-induced obesity (DIO) with insulin resistance. Methods DIO C57BL/6 mice maintained on a 60% kcal fat diet received five intraperitoneal (i.p.) injections of the bioactive peptide adropin34-76 (450 nmol/kg/i.p.). Following treatment, glucose tolerance and whole body insulin sensitivity were assessed and indirect calorimetry was employed to analyze whole body substrate oxidation preferences. Biochemical assays performed in skeletal muscle samples analyzed insulin signaling action and substrate oxidation. Results Adropin treatment improved glucose tolerance, enhanced insulin action and augmented metabolic flexibility towards glucose utilization. In muscle, adropin treatment increased insulin-induced Akt phosphorylation and cell-surface expression of GLUT4 suggesting sensitization of insulin signaling pathways. Reduced incomplete fatty acid oxidation and increased CoA/acetyl-CoA ratio suggested improved mitochondrial function. The underlying mechanisms appear to involve suppressions of carnitine palmitoyltransferase-1B (CPT-1B) and CD36, two key enzymes in fatty acid utilization. Adropin treatment activated pyruvate dehydrogenase (PDH), a rate-limiting enzyme in glucose oxidation, and downregulated PDH kinase-4 (PDK-4) that inhibits PDH. Along with these changes, adropin treatment downregulated peroxisome proliferator-activated receptor-gamma coactivator-1α that regulates expression of Cpt1b, Cd36 and Pdk4. Conclusions Adropin treatment of DIO mice enhances glucose tolerance, ameliorates insulin resistance and promotes preferential use of carbohydrate over fat in fuel selection. Skeletal muscle is a key organ in mediating adropin's whole-body effects, sensitizing insulin signaling pathways and altering fuel selection preference to favor glucose while suppressing fat oxidation.
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Affiliation(s)
- Su Gao
- Department of Metabolism and Aging, Scripps Research Institute, Jupiter, FL, USA
| | - Ryan P. McMillan
- Department of Human Nutrition, Foods and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Qingzhang Zhu
- Department of Metabolism and Aging, Scripps Research Institute, Jupiter, FL, USA
| | - Gary D. Lopaschuk
- Department of Pediatrics, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
| | - Matthew W. Hulver
- Department of Human Nutrition, Foods and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Andrew A. Butler
- Department of Metabolism and Aging, Scripps Research Institute, Jupiter, FL, USA
- Department of Pharmacological & Physiological Science, Saint Louis University School of Medicine, Saint Louis, MO, USA
- Corresponding author. Pharmacological & Physiological Science, Saint Louis University School of Medicine, 1402 S Grand Blvd, St Louis, MO 63104, USA. Tel.: +1 314 977 6425; fax: +1 314 977 6410.
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8
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Yuan H, Niu Y, Liu X, Fu L. Exercise increases the binding of MEF2A to the Cpt1b promoter in mouse skeletal muscle. Acta Physiol (Oxf) 2014; 212:283-92. [PMID: 25213552 DOI: 10.1111/apha.12395] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/09/2014] [Accepted: 09/09/2014] [Indexed: 12/11/2022]
Abstract
AIM Muscle-type carnitine palmitoyltransferase 1 (CPT1b) plays an important role in skeletal muscle mitochondrial fatty acid β-oxidation. A myocyte-specific enhancer factor (MEF2) site that binds MEF2A in the promoter of Cpt1b has been identified. The aim of this study is to determine whether Cpt1b expression is regulated by MEF2 in response to exercise training. METHODS Twelve male, 14-week-old C57BL/6 mice underwent 6 weeks of treadmill exercise at 12 m min(-1), for 60 min day(-1), 5 days week(-1). Quadriceps muscles were analysed by real-time PCR, Western blot, chromatin immunoprecipitation. RESULTS The binding of MEF2A to the Cpt1b promoter was elevated in the quadriceps muscle of mice after 6-week aerobic exercise intervention. The repressor partner of MEF2, histone deacetylase 5 (HDAC5), binding to the Cpt1b promoter was decreased by exercise training. In C2C12 myoblast, MEF2A overexpression increased the Cpt1b mRNA expression and the Cpt1b promoter transcriptional activity, which were suppressed by HDAC5. Moreover, exercise training induced MEF2A hyperacetylation, which is strongly associated with its enhanced DNA-binding ability. The binding of both HDAC5 and histone deacetylase 3 (HDAC3) to MEF2A was decreased by exercise training. Overexpression of HDAC5 decreased exogenous MEF2A acetylation level with an increased binding of endogenous HDAC3 to MEF2A. Finally, the phosphorylation levels of HDAC5 Ser259 and Ser498 were increased by exercise training. Exercise training decreased the abundance of HDAC5 in the nucleus while increasing its abundance in the cytoplasm. CONCLUSION Our results indicated that exercise-induced CPT1b expression was at least in part mediated by HDAC5/MEF2A interaction.
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Affiliation(s)
- H. Yuan
- Department of Physiology and Pathophysiology; School of Basic Medical Science; Tianjin Medical University; Tianjin China
| | - Y. Niu
- Department of Physiology and Pathophysiology; School of Basic Medical Science; Tianjin Medical University; Tianjin China
- Department of Rehabilitation and Sports Medicine; Tianjin Medical University; Tianjin China
| | - X. Liu
- Department of Physiology and Pathophysiology; School of Basic Medical Science; Tianjin Medical University; Tianjin China
| | - L. Fu
- Department of Physiology and Pathophysiology; School of Basic Medical Science; Tianjin Medical University; Tianjin China
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9
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Boeckx C, Benítez-Burraco A. The shape of the human language-ready brain. Front Psychol 2014; 5:282. [PMID: 24772099 PMCID: PMC3983487 DOI: 10.3389/fpsyg.2014.00282] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 03/17/2014] [Indexed: 12/14/2022] Open
Abstract
Our core hypothesis is that the emergence of our species-specific language-ready brain ought to be understood in light of the developmental changes expressed at the levels of brain morphology and neural connectivity that occurred in our species after the split from Neanderthals–Denisovans and that gave us a more globular braincase configuration. In addition to changes at the cortical level, we hypothesize that the anatomical shift that led to globularity also entailed significant changes at the subcortical level. We claim that the functional consequences of such changes must also be taken into account to gain a fuller understanding of our linguistic capacity. Here we focus on the thalamus, which we argue is central to language and human cognition, as it modulates fronto-parietal activity. With this new neurobiological perspective in place, we examine its possible molecular basis. We construct a candidate gene set whose members are involved in the development and connectivity of the thalamus, in the evolution of the human head, and are known to give rise to language-associated cognitive disorders. We submit that the new gene candidate set opens up new windows into our understanding of the genetic basis of our linguistic capacity. Thus, our hypothesis aims at generating new testing grounds concerning core aspects of language ontogeny and phylogeny.
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Affiliation(s)
- Cedric Boeckx
- Catalan Institute for Advanced Studies and Research (ICREA) Barcelona, Spain ; Department of Linguistics, Universitat de Barcelona Barcelona, Spain
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10
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Functional crosstalk of PGC-1 coactivators and inflammation in skeletal muscle pathophysiology. Semin Immunopathol 2013; 36:27-53. [DOI: 10.1007/s00281-013-0406-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 10/29/2013] [Indexed: 02/06/2023]
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11
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Wallace MA, Russell AP. Striated muscle activator of Rho signaling is required for myotube survival but does not influence basal protein synthesis or degradation. Am J Physiol Cell Physiol 2013; 305:C414-26. [PMID: 23720020 DOI: 10.1152/ajpcell.00421.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Skeletal muscle mass is regulated by sensing and transmitting extracellular mechanical stress signals to intracellular signaling pathways controlling protein synthesis and degradation. Striated muscle activator of Rho signaling (STARS) is a muscle-specific actin-binding protein that is sensitive to extracellular stress signals. STARS stimulates actin polymerization and influences serum response factor (SRF) and peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α transcription of genes involved in muscle growth, structure, and contraction. The role of STARS in skeletal muscle cells is not well understood. This study investigated whether STARS influenced C2C12 myotube growth by regulating protein synthesis and degradation. The influence of STARS on Pgc-1α, Srf, and Errα mRNA levels, as well as several of their downstream targets involved in muscle cell growth, contraction, and metabolism, was also investigated. STARS overexpression increased actin polymerization, with no effect on protein synthesis, protein degradation, or Akt phosphorylation. STARS overexpression increased Pgc-1α, Srf, Ckmt2, Cpt-1β, and Mhc1 mRNA. STARS knockdown reduced actin polymerization and increased cell death and dead cell protease activity. It also increased markers of inflammation (Casp1, Il-1β, and Mcp-1), regeneration (Socs3 and Myh8), and fast myosin isoforms (Mhc2a and Mhc2x). We show for the first time in muscle cells that STARS overexpression increases actin polymerization and shifts the muscle cell to a more oxidative phenotype. The suppression of STARS causes cell death and increases markers of necrosis, inflammation, and regeneration. As STARS levels are suppressed in clinical models associated with increased necrosis and inflammation, such as aging and limb immobilization, rescuing STARS maybe a future therapeutic strategy to maintain skeletal muscle function and attenuate contraction-induced muscle damage.
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Affiliation(s)
- Marita A Wallace
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
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12
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Sharma V, McNeill JH. Parallel effects of β-adrenoceptor blockade on cardiac function and fatty acid oxidation in the diabetic heart: Confronting the maze. World J Cardiol 2011; 3:281-302. [PMID: 21949571 PMCID: PMC3176897 DOI: 10.4330/wjc.v3.i9.281] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 07/18/2011] [Accepted: 07/25/2011] [Indexed: 02/06/2023] Open
Abstract
Diabetic cardiomyopathy is a disease process in which diabetes produces a direct and continuous myocardial insult even in the absence of ischemic, hypertensive or valvular disease. The β-blocking agents bisoprolol, carvedilol and metoprolol have been shown in large-scale randomized controlled trials to reduce heart failure mortality. In this review, we summarize the results of our studies investigating the effects of β-blocking agents on cardiac function and metabolism in diabetic heart failure, and the complex inter-related mechanisms involved. Metoprolol inhibits fatty acid oxidation at the mitochondrial level but does not prevent lipotoxicity; its beneficial effects are more likely to be due to pro-survival effects of chronic treatment. These studies have expanded our understanding of the range of effects produced by β-adrenergic blockade and show how interconnected the signaling pathways of function and metabolism are in the heart. Although our initial hypothesis that inhibition of fatty acid oxidation would be a key mechanism of action was disproved, unexpected results led us to some intriguing regulatory mechanisms of cardiac metabolism. The first was upstream stimulatory factor-2-mediated repression of transcriptional master regulator PGC-1α, most likely occurring as a consequence of the improved function; it is unclear whether this effect is unique to β-blockers, although repression of carnitine palmitoyltransferase (CPT)-1 has not been reported with other drugs which improve function. The second was the identification of a range of covalent modifications which can regulate CPT-1 directly, mediated by a signalome at the level of the mitochondria. We also identified an important interaction between β-adrenergic signaling and caveolins, which may be a key mechanism of action of β-adrenergic blockade. Our experience with this labyrinthine signaling web illustrates that initial hypotheses and anticipated directions do not have to be right in order to open up meaningful directions or reveal new information.
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Affiliation(s)
- Vijay Sharma
- Vijay Sharma, John H McNeill, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3.F, Canada
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13
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Wallace MA, Hock MB, Hazen BC, Kralli A, Snow RJ, Russell AP. Striated muscle activator of Rho signalling (STARS) is a PGC-1α/oestrogen-related receptor-α target gene and is upregulated in human skeletal muscle after endurance exercise. J Physiol 2011; 589:2027-39. [PMID: 21486805 PMCID: PMC3090601 DOI: 10.1113/jphysiol.2011.205468] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 02/15/2011] [Indexed: 01/26/2023] Open
Abstract
The striated muscle activator of Rho signalling (STARS) is an actin-binding protein specifically expressed in cardiac, skeletal and smooth muscle. STARS has been suggested to provide an important link between the transduction of external stress signals to intracellular signalling pathways controlling genes involved in the maintenance of muscle function. The aims of this study were firstly, to establish if STARS, as well as members of its downstream signalling pathway, are upregulated following acute endurance cycling exercise; and secondly, to determine if STARS is a transcriptional target of peroxisome proliferator-activated receptor gamma co-activator 1-α (PGC-1α) and oestrogen-related receptor-α (ERRα). When measured 3 h post-exercise, STARS mRNA and protein levels as well as MRTF-A and serum response factor (SRF) nuclear protein content, were significantly increased by 140, 40, 40 and 40%, respectively. Known SRF target genes, carnitine palmitoyltransferase-1β (CPT-1β) and jun B proto-oncogene (JUNB), as well as the exercise-responsive genes PGC-1α mRNA and ERRα were increased by 2.3-, 1.8-, 4.5- and 2.7-fold, 3 h post-exercise. Infection of C2C12 myotubes with an adenovirus-expressing human PGC-1α resulted in a 3-fold increase in Stars mRNA, a response that was abolished following the suppression of endogenous ERRα. Over-expression of PGC-1α also increased Cpt-1β, Cox4 and Vegf mRNA by 6.2-, 2.0- and 2.0-fold, respectively. Suppression of endogenous STARS reduced basal Cpt-1β levels by 8.2-fold and inhibited the PGC-1α-induced increase in Cpt-1β mRNA. Our results show for the first time that the STARS signalling pathway is upregulated in response to acute endurance exercise. Additionally, we show in C2C12 myotubes that the STARS gene is a PGC-1α/ERRα transcriptional target. Furthermore, our results suggest a novel role of STARS in the co-ordination of PGC-1α-induced upregulation of the fat oxidative gene, CPT-1β.
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Affiliation(s)
- Marita A Wallace
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood 3125, Australia
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14
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Takami G, Ota M, Nakashima A, Kaneko YS, Mori K, Nagatsu T, Ota A. Effects of atypical antipsychotics and haloperidol on PC12 cells: only aripiprazole phosphorylates AMP-activated protein kinase. J Neural Transm (Vienna) 2010; 117:1139-53. [PMID: 20686905 DOI: 10.1007/s00702-010-0457-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 07/22/2010] [Indexed: 01/10/2023]
Abstract
By converting changes in intracellular energy status to changes in cell membrane polarization, ATP-sensitive K(+) (K(ATP)) channels in hypothalamic appetite-regulating neurons play a critical role in linking neuronal electrochemical function, metabolic and energy status, and feeding behavior. Most atypical antipsychotics (AAPs) increase the appetite of patients with schizophrenia and thus cause obesity. This study aimed to explain the mechanism underlying AAP-induced appetite stimulation, based on the fact that the efficiency of fatty acid uptake into mitochondria generating ATP through β-oxidation is determined by the rate of fatty acid synthesis. Using PC12 cells exposed to clozapine, olanzapine, risperidone, quetiapine, ziprasidone, aripiprazole, and haloperidol, we measured intracellular ATP and mRNA and protein expression of enzymes and related substances involved in fatty acid synthesis and K(ATP) channel function. Forty-eight-hour treatment of cells with 50 μM aripiprazole in 5.6 mM glucose decreased intracellular ATP. Only 50 μM aripiprazole phosphorylated AMP-activated protein kinase (AMPK); none of the other antipsychotics did so to a detectable level. Expression of carnitine palmitoyltransferase 1a, uncoupling protein 2, and sulfonylurea receptor 1 was unaffected by the antipsychotics, although expression of their mRNA was affected by AAPs. Pyrilamine (H(1) receptor antagonist), ketanserin (5HT(2) receptor antagonist), and raclopride (D(2) receptor antagonist) alone or in combination had no effect on expression of the aforementioned proteins. Therefore, although this study did not differentiate orexigenic and non-orexigenic AAPs, it suggests that aripiprazole is unique in its ability to activate AMPK.
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Affiliation(s)
- Goro Takami
- Department of Physiology, School of Medicine, Fujita Health University, Toyoake 470-1192, Japan
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15
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Schreurs M, Kuipers F, van der Leij FR. Regulatory enzymes of mitochondrial beta-oxidation as targets for treatment of the metabolic syndrome. Obes Rev 2010; 11:380-8. [PMID: 19694967 DOI: 10.1111/j.1467-789x.2009.00642.x] [Citation(s) in RCA: 203] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Insulin sensitizers like metformin generally act through pathways triggered by adenosine monophosphate-activated protein kinase. Carnitine palmitoyltransferase 1 (CPT1) controls mitochondrial beta-oxidation and is inhibited by malonyl-CoA, the product of acetyl-CoA carboxylase (ACC). The adenosine monophosphate-activated protein kinase-ACC-CPT1 axis tightly regulates mitochondrial long-chain fatty acid oxidation. Evidence indicates that ACC2, the isoform located in close proximity to CPT1, is the major regulator of CPT1 activity. ACC2 as well as CPT1 are therefore potential targets to treat components of the metabolic syndrome such as obesity and insulin resistance. Reversible inhibitors of the liver isoform of CPT1, developed to prevent ketoacidosis and hyperglycemia, have been found to be associated with side effects like hepatic steatosis. However, stimulation of systemic CPT1 activity may be an attractive means to accelerate peripheral fatty acid oxidation and hence improve insulin sensitivity. Stimulation of CPT1 can be achieved by elimination or inhibition of ACC2 activity and through activating transcription factors like peroxisome proliferator-activated receptors and their protein partners. The latter leads to enhanced CPT1 gene expression. Recent developments are discussed, including a recently identified CPT1 isoform, i.e. CPT1C. This protein is highly expressed in the brain and may provide a target for new tools to prevent obesity.
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Affiliation(s)
- M Schreurs
- Department of Pediatrics, Center for Liver, Digestive and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
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16
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Erkens T, Vandesompele J, Van Zeveren A, Peelman LJ. Correlation between porcine PPARGC1A mRNA expression and its downstream target genes in backfat and longissimus dorsi muscle. J Appl Genet 2010; 50:361-9. [PMID: 19875886 DOI: 10.1007/bf03195694] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Knowledge of in vivo relationship between the coactivator PPARGC1A and its target genes is very limited, especially in the pig. In this study, a real-time PCR experiment was performed on longissimus dorsi muscle (MLD) and backfat with 10 presumed PPARGC1A downstream target genes, involved in energy and fat metabolism, to identify possible relationships with PPARGC1A mRNA expression in vivo in the pig (n = 20). Except for UCP3 and LPL, a very significant difference in expression was found between MLD and backfat for all genes (P < 0.01). Hierarchical cluster analysis and the significant pairing of mRNA expression data between sampling locations suggested a genetic regulation of the expression of several target genes. A positive correlation with PPARGC1A was found for CPT1B, GLUT4, PDK4, and TFAM (P < 0.0001). A negative correlation was found for UCP2, FABP4, LEP (P < 0.0001), and TNF (P = 0.0071). No significant correlation was detected for UCP3 and LPL. This study provides evidence for a clear difference in mRNA expression of crucial genes in fat and energy metabolism between 2 important tissues. Our data suggest a clear impact of PPARGC1A on energy and lipid metabolism in vivo in the pig, through several of these downstream target genes.
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Affiliation(s)
- T Erkens
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Belgium.
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17
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Sharma V, Dhillon P, Parsons H, Allard MF, McNeill JH. Metoprolol represses PGC1α-mediated carnitine palmitoyltransferase-1B expression in the diabetic heart. Eur J Pharmacol 2009; 607:156-66. [DOI: 10.1016/j.ejphar.2009.02.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Revised: 01/17/2009] [Accepted: 02/09/2009] [Indexed: 10/21/2022]
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18
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Wang H, Peiris TH, Mowery A, Le Lay J, Gao Y, Greenbaum LE. CCAAT/enhancer binding protein-beta is a transcriptional regulator of peroxisome-proliferator-activated receptor-gamma coactivator-1alpha in the regenerating liver. Mol Endocrinol 2008; 22:1596-605. [PMID: 18467525 DOI: 10.1210/me.2007-0388] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The transcriptional coactivator peroxisome-proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) is induced in the liver in response to fasting and coordinates the activation of targets necessary for increasing energy production for gluconeogenesis and ketogenesis. After partial hepatectomy, the liver must restore its mass while maintaining metabolic homeostasis to ensure survival. Here we report that PGC-1alpha is rapidly and dramatically induced after hepatectomy, with an amplitude of induction that exceeds the fasting response. Maximal activation of PGC-1alpha after hepatectomy is dependent on the basic leucine zipper transcription factor, CCAAT/enhancer binding protein-beta (C/EBPbeta), a critical factor in hepatocyte proliferation. We demonstrate in vivo C/EBPbeta binding to C/EBP and cAMP response element sites in the PGC-1alpha promoter and show that the C/EBP site is essential for PGC-1alpha activation. Expression of the PGC-1alpha target, carnitine palmitoyl transferase 1a, the rate-limiting enzyme in fatty acid beta-oxidation, and of long-chain acyl-coenzyme A dehydrogenase, an enzyme involved in beta-oxidation of long chain fatty acids, was significantly reduced in C/EBPbeta(-/-) livers after hepatectomy. These findings identify C/EBPbeta as a direct activator of PGC-1alpha in the regenerating liver. The demonstration of a functional link between C/EBPbeta and PGC-1alpha activation provides a likely mechanism for how upstream signaling pathways in the regenerating liver can enable the adaptation to the changed metabolic status.
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Affiliation(s)
- Haitao Wang
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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19
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Abstract
Exercise increases the metabolic capacity of skeletal muscle, which improves whole-body energy homeostasis and contributes to the positive health benefits of exercise. This is, in part, mediated by increases in the expression of a number of metabolic enzymes, regulated largely at the level of transcription. At a molecular level, many of these genes are regulated by the class II histone deacetylase (HDAC) family of transcriptional repressors, in particular HDAC5, through their interaction with myocyte enhancer factor 2 transcription factors. HDAC5 kinases, including 5'-AMP-activated protein kinase and protein kinase D, appear to regulate skeletal muscle metabolic gene transcription by inactivating HDAC5 and inducing HDAC5 nuclear export. These mechanisms appear to participate in exercise-induced gene expression and could be important for skeletal muscle adaptations to exercise.
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Affiliation(s)
- Sean L McGee
- Department of Physiology, The University of Melbourne, Parkville, Victoria 3010, Australia
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20
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Potthoff MJ, Wu H, Arnold MA, Shelton JM, Backs J, McAnally J, Richardson JA, Bassel-Duby R, Olson EN. Histone deacetylase degradation and MEF2 activation promote the formation of slow-twitch myofibers. J Clin Invest 2007; 117:2459-67. [PMID: 17786239 PMCID: PMC1957540 DOI: 10.1172/jci31960] [Citation(s) in RCA: 317] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Accepted: 05/29/2007] [Indexed: 12/29/2022] Open
Abstract
Skeletal muscle is composed of heterogeneous myofibers with distinctive rates of contraction, metabolic properties, and susceptibility to fatigue. We show that class II histone deacetylase (HDAC) proteins, which function as transcriptional repressors of the myocyte enhancer factor 2 (MEF2) transcription factor, fail to accumulate in the soleus, a slow muscle, compared with fast muscles (e.g., white vastus lateralis). Accordingly, pharmacological blockade of proteasome function specifically increases expression of class II HDAC proteins in the soleus in vivo. Using gain- and loss-of-function approaches in mice, we discovered that class II HDAC proteins suppress the formation of slow twitch, oxidative myofibers through the repression of MEF2 activity. Conversely, expression of a hyperactive form of MEF2 in skeletal muscle of transgenic mice promotes the formation of slow fibers and enhances running endurance, enabling mice to run almost twice the distance of WT littermates. Thus, the selective degradation of class II HDACs in slow skeletal muscle provides a mechanism for enhancing physical performance and resistance to fatigue by augmenting the transcriptional activity of MEF2. These findings provide what we believe are new insights into the molecular basis of skeletal muscle function and have important implications for possible therapeutic interventions into muscular diseases.
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Affiliation(s)
- Matthew J. Potthoff
- Department of Molecular Biology,
Department of Internal Medicine, and
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Hai Wu
- Department of Molecular Biology,
Department of Internal Medicine, and
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Michael A. Arnold
- Department of Molecular Biology,
Department of Internal Medicine, and
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - John M. Shelton
- Department of Molecular Biology,
Department of Internal Medicine, and
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Johannes Backs
- Department of Molecular Biology,
Department of Internal Medicine, and
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - John McAnally
- Department of Molecular Biology,
Department of Internal Medicine, and
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - James A. Richardson
- Department of Molecular Biology,
Department of Internal Medicine, and
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Rhonda Bassel-Duby
- Department of Molecular Biology,
Department of Internal Medicine, and
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Eric N. Olson
- Department of Molecular Biology,
Department of Internal Medicine, and
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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21
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Taulan M, Lopez E, Guittard C, René C, Baux D, Altieri JP, DesGeorges M, Claustres M, Romey MC. First functional polymorphism in CFTR promoter that results in decreased transcriptional activity and Sp1/USF binding. Biochem Biophys Res Commun 2007; 361:775-81. [PMID: 17678620 DOI: 10.1016/j.bbrc.2007.07.091] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2007] [Accepted: 07/18/2007] [Indexed: 11/23/2022]
Abstract
Growing evidences show that functionally relevant polymorphisms in various promoters alter both transcriptional activity and affinities of existing protein-DNA interactions, and thus influence disease progression in humans. We previously reported the -94G>T CFTR promoter variant in a female CF patient in whom any known disease-causing mutation has been detected. To investigate whether the -94G>T could be a regulatory variant, we have proceeded to in silico analyses and functional studies including EMSA and reporter gene assays. Our data indicate that the promoter variant decreases basal CFTR transcriptional activity in different epithelial cells and alters binding affinities of both Sp1 and USF nuclear proteins to the CFTR promoter. The present report provides evidence for the first functional polymorphism that negatively affects the CFTR transcriptional activity and demonstrates a cooperative role of Sp1 and USF transcription factors in transactivation of the CFTR gene promoter.
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Affiliation(s)
- M Taulan
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.
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22
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Handschin C, Spiegelman BM. Peroxisome proliferator-activated receptor gamma coactivator 1 coactivators, energy homeostasis, and metabolism. Endocr Rev 2006; 27:728-35. [PMID: 17018837 DOI: 10.1210/er.2006-0037] [Citation(s) in RCA: 858] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Many biological programs are regulated at the transcriptional level. This is generally achieved by the concerted actions of several transcription factors. Recent findings have shown that, in many cases, transcriptional coactivators coordinate the overall regulation of the biological programs. One of the best-studied examples of coactivator control of metabolic pathways is the peroxisome proliferator-activated receptor coactivator 1 (PGC-1) family. These proteins are strong activators of mitochondrial function and are thus dominant regulators of oxidative metabolism in a variety of tissues. The PGC-1 coactivators themselves are subject to powerful regulation at the transcriptional and posttranslational levels. Recent studies have elucidated the function of the PGC-1 coactivators in different tissues and have highlighted the implications of PGC-1 dysregulation in diseases such as diabetes, obesity, cardiomyopathy, or neurodegeneration.
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Affiliation(s)
- Christophe Handschin
- Dana-Farber Cancer Institute and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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23
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Soyal S, Krempler F, Oberkofler H, Patsch W. PGC-1alpha: a potent transcriptional cofactor involved in the pathogenesis of type 2 diabetes. Diabetologia 2006; 49:1477-88. [PMID: 16752166 DOI: 10.1007/s00125-006-0268-6] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Accepted: 02/03/2006] [Indexed: 12/24/2022]
Abstract
Data derived from several recent studies implicate peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) in the pathogenesis of type 2 diabetes. Lacking DNA binding activity itself, PGC-1alpha is a potent, versatile regulator of gene expression that co-ordinates the activation and repression of transcription via protein-protein interactions with specific, as well as more general, factors contained within the basal transcriptional machinery. PGC-1alpha is suggested to play a pivotal role in the control of genetic pathways that result in homeostatic glucose utilisation in liver and muscle, beta cell insulin secretion and mitochondrial biogenesis. This review focuses on the role of PGC-1alpha in glucose metabolism and considers how PGC-1alpha links cellular glucose metabolism, insulin sensitivity and mitochondrial function, and why defects in PGC-1alpha expression and regulation may contribute to the pathophysiology of type 2 diabetes in humans.
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Affiliation(s)
- S Soyal
- Department of Internal Medicine, Krankenhaus Hallein, 5400, Hallein, Austria
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Abstract
Our understanding of metabolism is undergoing a dramatic shift. Indeed, the efforts made towards elucidating the mechanisms controlling the major regulatory pathways are now being rewarded. At the molecular level, the crucial role of transcription factors is particularly well-illustrated by the link between alterations of their functions and the occurrence of major metabolic diseases. In addition, the possibility of manipulating the ligand-dependent activity of some of these transcription factors makes them attractive as therapeutic targets. The aim of this review is to summarize recent knowledge on the transcriptional control of metabolic homeostasis. We first review data on the transcriptional regulation of the intermediary metabolism, i.e., glucose, amino acid, lipid, and cholesterol metabolism. Then, we analyze how transcription factors integrate signals from various pathways to ensure homeostasis. One example of this coordination is the daily adaptation to the circadian fasting and feeding rhythm. This section also discusses the dysregulations causing the metabolic syndrome, which reveals the intricate nature of glucose and lipid metabolism and the role of the transcription factor PPARgamma in orchestrating this association. Finally, we discuss the molecular mechanisms underlying metabolic regulations, which provide new opportunities for treating complex metabolic disorders.
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Affiliation(s)
- Béatrice Desvergne
- Center for Integrative Genomics, National Centre of Competence in Research Frontiers in Genetics, University of Lausanne, Lausanne, Switzerland
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25
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Makaula S, Adam T, Essop MF. Upstream stimulatory factor 1 transactivates the human gene promoter of the cardiac isoform of acetyl-CoA carboxylase. Arch Biochem Biophys 2005; 446:91-100. [PMID: 16376850 DOI: 10.1016/j.abb.2005.10.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Revised: 10/26/2005] [Accepted: 10/29/2005] [Indexed: 11/26/2022]
Abstract
E-box cis-elements act as binding sites for upstream stimulatory factors (USFs), putative glucose-responsive transcriptional modulators. Since four E-boxes were identified on the human ACCbeta promoter, we hypothesized that USF1 induces ACCbeta expression in a glucose-dependent manner. Here, murine cardiac ACCbeta expression was significantly increased in response to high carbohydrate re-feeding after fasting. However, transfection studies showed no difference in ACCbeta promoter activity in neonatal cardiomyocytes and CV-1 fibroblasts after low (5.5mM) and high (25 mM) glucose exposure. USF1 overexpression significantly increased ACCbeta promoter activity in both cell lines under low glucose conditions. With high glucose exposure, USF1 further induced ACCbeta promoter activity only in CV-1 fibroblasts. USF1-induced ACCbeta promoter responsiveness was markedly attenuated when co-transfecting cardiomyocytes with a -93/+65 or -38/+65 promoter deletion construct (lacking E-boxes 1-3). Thus, USF1 transactivates the human ACCbeta promoter in the heart, likely through an E-box cis-element located close to the transcription start site.
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Affiliation(s)
- Siyanda Makaula
- Hatter Heart Research Institute, University of Cape Town Faculty of Health Sciences, Observatory 7925, South Africa
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26
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Segade F, Mecham RP. Regulatory elements of microfibril-associated glycoprotein-1 gene expression in muscle cells. ACTA ACUST UNITED AC 2005; 1731:215-24. [PMID: 16321658 DOI: 10.1016/j.bbaexp.2005.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 10/17/2005] [Accepted: 10/19/2005] [Indexed: 11/22/2022]
Abstract
The Mfap2 gene encodes the microfibril-associated glycoprotein-1 (MAGP1), an extracellular matrix protein of microfibrillar structures. The gene is transcribed from a major transcription start site embedded in a CpG island. Mapping of transcriptionally active regions in the 5' flanking sequence identified a region, located between nucleotides -339 and -109 as the Mfap2 basal promoter. Site-directed and random mutagenesis demonstrated that a KLF sequence motif at -256/-270, an E-box at -222/-229, and a GC-box at -117/-125, are critical for the promoter function. Using electrophoresis mobility shift assays, we find that the KLF motif mediates the binding of GKLF/KLF4, whereas the E-box is a target for both Upstream Stimulatory Factors 1 and 2, and the GC box at -117/-125 forms complexes with Sp1 and Sp3, but not with Sp4 or AP2alpha. A sequence element spanning position -150 may represent the binding motif of an uncharacterized transcription factor. The basal transcriptional regulation of Mfap2 in muscle cells is discussed.
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Affiliation(s)
- Fernando Segade
- Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Phan D, Rasmussen TL, Nakagawa O, McAnally J, Gottlieb PD, Tucker PW, Richardson JA, Bassel-Duby R, Olson EN. BOP, a regulator of right ventricular heart development, is a direct transcriptional target of MEF2C in the developing heart. Development 2005; 132:2669-78. [PMID: 15890826 DOI: 10.1242/dev.01849] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The vertebrate heart is assembled during embryogenesis in a modular manner from different populations of precursor cells. The right ventricular chamber and outflow tract are derived primarily from a population of progenitors known as the anterior heart field. These regions of the heart are severely hypoplastic in mutant mice lacking the myocyte enhancer factor 2C (MEF2C) and BOP transcription factors, suggesting that these cardiogenic regulatory factors may act in a common pathway for development of the anterior heart field and its derivatives. We show that Bop expression in the developing heart depends on the direct binding of MEF2C to a MEF2-response element in the Bop promoter that is necessary and sufficient to recapitulate endogenous Bop expression in the anterior heart field and its cardiac derivatives during mouse development. The Bop promoter also directs transcription in the skeletal muscle lineage, but only cardiac expression is dependent on MEF2. These findings identify Bop as an essential downstream effector gene of MEF2C in the developing heart, and reveal a transcriptional cascade involved in development of the anterior heart field and its derivatives.
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Affiliation(s)
- Dillon Phan
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA
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Teruel T, Hernandez R, Rial E, Martin-Hidalgo A, Lorenzo M. Rosiglitazone up-regulates lipoprotein lipase, hormone-sensitive lipase and uncoupling protein-1, and down-regulates insulin-induced fatty acid synthase gene expression in brown adipocytes of Wistar rats. Diabetologia 2005; 48:1180-8. [PMID: 15887043 DOI: 10.1007/s00125-005-1744-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Accepted: 12/30/2004] [Indexed: 11/24/2022]
Abstract
AIMS/HYPOTHESIS Although thiazolidinediones are now widely used to treat type 2 diabetes, their mechanism of action remains largely unknown. They are agonists for the transcription factor PPARgamma, and in addition to their insulin-sensitising effects, they can promote adipogenesis and control gene expression in adipose tissues. We have explored the effect of rosiglitazone on insulin-mediated induction of pivotal genes involved in lipid metabolism and thermogenesis in brown fat. The genes studied were: (1) lipoprotein lipase (lpl), which is involved in lipid uptake; (2) hormone-sensitive lipase (hsl), which mobilises fatty acids from stored triglycerides; (3) fatty acid synthase (fas), which regulates de novo lipogenesis; and (4) the uncoupling proteins (ucp) 1 and 3, which control thermogenesis. METHODS We used fetal rat primary brown adipocytes cultured with insulin, rosiglitazone or both combined. Then, we studied gene expression by northern and western blotting, as well as 'run-on' and gel-shift assays to identify binding of potential transcription factors to the fas promoter. RESULTS Exposure to rosiglitazone for 24 h induced ucp-1, lpl and hsl gene expression and when rosiglitazone was combined with insulin a synergistic effect on lpl and ucp-3 mRNA expression was produced. These effects were consistent with increased LPL and HSL activities as well as respiration rates, mainly in response to exogenous palmitate. In contrast, treatment with rosiglitazone did not alter FAS mRNA basal levels but prevented the induction elicited by insulin in a time- and dose-dependent manner. Correspondingly diminished FAS protein levels and activity, as well as cellular lipid content, were observed, indicating an antilipogenic action of rosiglitazone in brown adipocytes. Furthermore, rosiglitazone impaired insulin increase in the FAS transcription rate by antagonising insulin-induced binding of upstream stimulatory factors to the E-box consensus sequence in the FAS promoter and insulin-induced binding of activating protein-1. CONCLUSIONS/INTERPRETATION Rosiglitazone prevents insulin-induced up-regulation of the main lipogenic enzyme but increases the expression of those enzymes involved in lipid uptake and mobilisation, favouring fatty acid utilisation through uncoupled respiration.
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Affiliation(s)
- T Teruel
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University, 28040, Madrid, Spain
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Shoulders CC, Naoumova RP. USF1 implicated in the aetiology of familial combined hyperlipidaemia and the metabolic syndrome. Trends Mol Med 2005; 10:362-5. [PMID: 15310455 DOI: 10.1016/j.molmed.2004.06.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The upstream stimulatory factor (USF) proteins are ubiquitously expressed and, as such, represent unusual candidates for involvement in disorders of carbohydrate and lipid metabolism. Nonetheless, a recent study has reported an association between specific alleles of USF1 and familial combined hyperlipidaemia, a common disorder that substantially increases the risk of premature atherosclerotic cardiovascular disease. USF1 might, therefore, also contribute to the metabolic syndrome. The use of chromatin immunoprecipitation methodologies combined with promoter microarray assays will help to define the transcriptional networks that underlie whole-body glucose and lipid homeostasis.
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Affiliation(s)
- Carol C Shoulders
- MRC Clinical Sciences Centre, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
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Yan S, Sloane BF. Isolation of a novel USF2 isoform: repressor of cathepsin B expression. Gene 2004; 337:199-206. [PMID: 15276216 DOI: 10.1016/j.gene.2004.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2004] [Revised: 04/26/2004] [Accepted: 05/06/2004] [Indexed: 11/17/2022]
Abstract
We previously demonstrated that upstream stimulatory factor 1 (USF1) and USF2 regulate transcription of cathepsin B. Here, we have cloned a novel transcript variant of USF2 from a human DU145 prostate cancer cell line by reverse transcription-polymerase chain reaction (RT-PCR). This new transcript variant, designated USF2c, results from alternative splicing of the primary USF2 transcript using a cryptic splicing acceptor site within exon 6. As a consequence, USF2c is missing exons 4, 5, and part of exon 6. USF2c can be transcribed and translated to a protein of approximately 29 kDa in vitro, and the resulting USF2c protein can bind as a homodimer to the E-box of the cathepsin B promoter. USF2c is expressed in two other prostate cancer cell lines (LNCaP, PC3), and U87 human glioblastoma cells as are USF2a and USF2b, two previously identified isoforms of USF2. Cotransfection experiments in DU145 and U87 cells demonstrate that USF2c can down-regulate expression of cathepsin B. These results suggest that USF2c regulates expression of cathepsin B by binding to the E box element in the cathepsin B promoter as a repressor.
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Affiliation(s)
- Shiqing Yan
- Department of Pharmacology, Wayne State University, Detroit, MI 48201, USA.
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31
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Baldán A, Relat J, Marrero PF, Haro D. Functional interaction between peroxisome proliferator-activated receptors-alpha and Mef-2C on human carnitine palmitoyltransferase 1beta (CPT1beta) gene activation. Nucleic Acids Res 2004; 32:4742-9. [PMID: 15356291 PMCID: PMC519104 DOI: 10.1093/nar/gkh806] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Muscle-type carnitine palmitoyltransferase 1 (CPT1beta) is considered to be the gene that controls fatty acid mitochondrial beta-oxidation. A functional peroxisome proliferator-activated receptor (PPAR) responsive element (PPRE) and a myocite-specific (MEF2) site that binds MEF2A and MEF2C in the promoter of this gene had been previously identified. We investigated the roles of the PPRE and the MEF2 binding sites and the potential interaction between PPARalpha and MEF2C regulating the CPT1beta gene promoter. Mutation analysis indicated that the MEF2 site contributed to the activation of the CPT1beta promoter by PPAR in C2C12 cells. The reporter construct containing the PPRE and the MEF2C site was synergistically activated by co-expression of PPAR, retinoid X receptor (RXR) and MEF2C in non-muscle cells. Moreover, protein-binding assays demonstrated that MEF2C and PPAR specifically bound to one another in vitro. Also for the synergistic activation of the CPT1beta gene promoter by MEF2C and PPARalpha-RXRalpha, a precise arrangement of its binding sites was essential.
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Affiliation(s)
- Angel Baldán
- Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Barcelona, Avenue Diagonal 643, E-08028 Barcelona, Spain
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Okada Y, Matsuura E, Tozuka Z, Nagai R, Watanabe A, Matsumoto K, Yasui K, Jackman RW, Nakano T, Doi T. Upstream stimulatory factors stimulate transcription through E-box motifs in the PF4 gene in megakaryocytes. Blood 2004; 104:2027-34. [PMID: 15187018 DOI: 10.1182/blood-2003-09-3107] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Platelet factor 4 (PF4) is expressed during megakaryocytic differentiation. We previously demonstrated that the homeodomain proteins (myeloid ecotropic integration site 1 [MEIS1], Pbx-regulating protein 1 [PREP1], and pre-B-cell leukemia transcription factors [PBXs]) bind to the novel regulatory element tandem repeat of MEIS1 binding element [TME] and transactivate the rat PF4 promoter. In the present study, we investigated and identified other TME binding proteins in megakaryocytic HEL cells using mass spectrometry. Among identified proteins, we focused on upstream stimulatory factor (USF1) and USF2 and investigated their effects on the PF4 promoter. USF1 and 2 bound to the E-box motif in the TME and strongly transactivated the PF4 promoter. Furthermore, physiologic bindings of USF1 and 2 to the TME in rat megakaryocytes were demonstrated by the chromatin immunoprecipitation (ChIP) assay. Interestingly, the E-box motif in the TME was conserved in TME-like sequences of both the human and mouse PF4 promoters. USF1 and 2 also bound to the human TME-like sequence and transactivated the human PF4 promoter. Expressions of USF1 and 2 were detected by reverse-transcriptase-polymerase chain reaction (RT-PCR) in the human megakaryocytes derived from CD34+ cells. Thus, these studies demonstrate that the novel TME binding transcription factors, USF1 and 2, transactivate rat and human PF4 promoters and may play an important role in megakaryocytic gene expression.
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Affiliation(s)
- Yoshiaki Okada
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
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Ide T, Hong DD, Ranasinghe P, Takahashi Y, Kushiro M, Sugano M. Interaction of dietary fat types and sesamin on hepatic fatty acid oxidation in rats. Biochim Biophys Acta Mol Cell Biol Lipids 2004; 1682:80-91. [PMID: 15158759 DOI: 10.1016/j.bbalip.2004.02.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2003] [Revised: 01/30/2004] [Accepted: 02/10/2004] [Indexed: 12/27/2022]
Abstract
The interaction of sesamin, one of the most abundant lignans in sesame seed, and types of dietary fats affecting hepatic fatty acid oxidation was examined in rats. Rats were fed purified experimental diets supplemented with 0% or 0.2% sesamin (1:1 mixture of sesamin and episesamin), and containing 8% of either palm, safflower or fish oil for 15 days. Among the groups fed sesamin-free diets, the activity of various fatty acid oxidation enzymes was higher in rats fed fish oil than in those fed palm and safflower oils. Dietary sesamin increased enzyme activities in all groups of rats given different fats. The extent of the increase depended on dietary fat type, and a diet containing sesamin and fish oil in combination appeared to increase many of these parameters synergistically. In particular, the peroxisomal palmitoyl-CoA oxidation rate and acyl-CoA oxidase activity levels were much higher in rats fed sesamin and fish oil in combination than in animals fed sesamin and palm or safflower oil in combination. Analyses of mRNA levels revealed that a diet containing sesamin and fish oil increased the gene expression of various peroxisomal fatty acid oxidation enzymes and PEX11alpha, a peroxisomal membrane protein, in a synergistic manner while it increased the gene expression of mitochondrial fatty acid oxidation enzymes and microsomal cytochrome P-450 IV A1 in an additive manner. It was concluded that a diet containing sesamin and fish oil in combination synergistically increased hepatic fatty acid oxidation primarily through up-regulation of the gene expression of peroxisomal fatty acid oxidation enzymes.
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Affiliation(s)
- Takashi Ide
- Division of Food Functionality, National Food Research Institute, 2-1-12 Kannondai, Tsukuba 305-8642, Japan.
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Sayasith K, Bouchard N, Sawadogo M, Lussier JG, Sirois J. Molecular Characterization and Role of Bovine Upstream Stimulatory Factor 1 and 2 in the Regulation of the Prostaglandin G/H Synthase-2 Promoter in Granulosa Cells. J Biol Chem 2004; 279:6327-36. [PMID: 14660559 DOI: 10.1074/jbc.m311222200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transcriptional activation of the prostaglandin G/H synthase-2 (PGHS-2) gene in granulosa cells is required for ovulation. To directly study the ability of upstream stimulatory factor 1 (USF1) and USF2 to trans-activate the bovine PGHS-2 promoter in granulosa cells, USF1 or USF2 expression vectors were cotransfected with the PGHS-2/luciferase (LUC) chimeric construct, -149/-2PGHS-2.LUC. Results revealed that overexpression of USF1 or USF2 caused a marked and significant increase in basal and forskolin-inducible promoter activities (p<0.05), and these effects were dependent on the presence of a consensus E-box cis-element within the promoter fragment. Co-transfections with different N- and C-terminal truncated USF mutants led to significant reductions in promoter activation, as compared with full-length constructs (p<0.05), thus allowing identification of putative bovine USF functional domains. Overexpression of a USF2 truncated mutant lacking the first 220 residues (U2Delta1-220) acted as a dominant negative mutant and blocked endogenous and USF-stimulated PGHS-2 promoter activation. Interestingly, transfections with U2Delta1-220 blocked the forskolin-dependent induction of PGHS-2 mRNA in granulosa cells, whereas transfections with full-length USF2 increased PGHS-2 transcript levels. Immunoblot analyses confirmed overexpression of full-length and truncated USF proteins, and electrophoretic mobility shift assays (EMSAs) and supershift EMSAs established that the observed effects were dependent on specific interactions between USF proteins and the consensus E-box cis-element. Stimulation of cells with forskolin increased, whereas treatment of extracts with phosphatase decreased USF binding activities to the E-box. Thus, this study presents for the first time direct evidence for a role of USF proteins in the regulation of the PGHS-2 promoter in preovulatory granulosa cells.
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Affiliation(s)
- Khampoune Sayasith
- Centre de Recherche en Reproduction Animale and the Département de Biomédecine Vétérinaire, Faculté de Médecine Vétérinaire, Université de Montréal, CP 5000, Saint-Hyacinthe, Québec J2S 7C6, Canada
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Hatzivassiliou E, Koukos G, Ribeiro A, Zannis V, Kardassis D. Functional specificity of two hormone response elements present on the human apoA-II promoter that bind retinoid X receptor alpha/thyroid receptor beta heterodimers for retinoids and thyroids: synergistic interactions between thyroid receptor beta and upstream stimulatory factor 2a. Biochem J 2003; 376:423-31. [PMID: 12959642 PMCID: PMC1223787 DOI: 10.1042/bj20030549] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2003] [Revised: 08/05/2003] [Accepted: 09/05/2003] [Indexed: 11/17/2022]
Abstract
DNA binding and mutagenesis in vitro established that the -67/-55 region of the apoA-II (apolipoprotein A-II) promoter contains a thyroid HRE (hormone response element), which strongly binds RXRalpha (retinoid X receptor alpha)/T(3)Rbeta (thyroid receptor beta) heterodimers and weakly T(3)Rbeta homodimers, but does not bind other homo- or heterodimers of RXRalpha or orphan nuclear receptors. Transactivation was abolished by point mutations in the thyroid HRE. In co-transfection experiments of HEK-293 (human embryonic kidney 293) cells, the -911/+29 human apoA-II promoter was transactivated strongly by RXRalpha/T(3)Rbeta heterodimers in the presence of RA (9- cis retinoic acid) or T(3) (tri-iodothyronine). Homopolymeric promoters containing either three copies of the -73/-40 (element AIIAB) or four copies of the -738/-712 (element AIIJ) apoA-II promoter could be transactivated by RXRalpha/T(3)Rbeta heterodimers in COS-7 cells only in the presence of T(3) or RA respectively. RXRalpha/T(3)Rbeta heterodimers and USF2a (upstream stimulatory factor 2a) synergistically transactivated the -911/+29 apoA-II promoter in the presence of T(3). USF2a also enhanced the activity of a GAL4-T(3)Rbeta fusion protein in the presence of T(3) and suppressed the activity of a GAL4-RXRalpha fusion protein in the presence of RA. These findings suggest a functional specificity of the two HREs of the apoA-II promoter for retinoids and thyroids, which is modulated by synergistic or antagonistic interactions between RXRalpha/T(3)Rbeta heterodimers and the ubiquitous transcription factor USF2a.
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Affiliation(s)
- Eudoxia Hatzivassiliou
- Biomedical Sciences Research Center Al. Fleming, Institute of Immunology, 14-16 Al. Fleming Str., Vari GR-16672, Greece
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