1
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Chaudhuri SM, Weinberg SE, Wang D, Yalom LK, Montauti E, Iyer R, Tang AY, Torres Acosta MA, Shen J, Mani NL, Wang S, Liu K, Lu W, Bui TM, Manzanares LD, Dehghani Z, Wai CM, Gao B, Wei J, Yue F, Cui W, Singer BD, Sumagin R, Zhang Y, Fang D. Mediator complex subunit 1 architects a tumorigenic Treg cell program independent of inflammation. Cell Rep Med 2024; 5:101441. [PMID: 38428427 PMCID: PMC10983042 DOI: 10.1016/j.xcrm.2024.101441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 12/18/2023] [Accepted: 02/01/2024] [Indexed: 03/03/2024]
Abstract
While immunotherapy has revolutionized cancer treatment, its safety has been hampered by immunotherapy-related adverse events. Unexpectedly, we show that Mediator complex subunit 1 (MED1) is required for T regulatory (Treg) cell function specifically in the tumor microenvironment. Treg cell-specific MED1 deletion does not predispose mice to autoimmunity or excessive inflammation. In contrast, MED1 is required for Treg cell promotion of tumor growth because MED1 is required for the terminal differentiation of effector Treg cells in the tumor. Suppression of these terminally differentiated Treg cells is sufficient for eliciting antitumor immunity. Both human and murine Treg cells experience divergent paths of differentiation in tumors and matched tissues with non-malignant inflammation. Collectively, we identify a pathway promoting the differentiation of a Treg cell effector subset specific to tumors and demonstrate that suppression of a subset of Treg cells is sufficient for promoting antitumor immunity in the absence of autoimmune consequences.
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Affiliation(s)
- Shuvam M Chaudhuri
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Samuel E Weinberg
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Dongmei Wang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Lenore K Yalom
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Elena Montauti
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Radhika Iyer
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Amy Y Tang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Manuel A Torres Acosta
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Medical Scientist Training Program, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Jian Shen
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Nikita L Mani
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Shengnan Wang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Kun Liu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Weiyuan Lu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Triet M Bui
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Laura D Manzanares
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Zeinab Dehghani
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Ching Man Wai
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Beixue Gao
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Juncheng Wei
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Feng Yue
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Weiguo Cui
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Benjamin D Singer
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Ronen Sumagin
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Yana Zhang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Deyu Fang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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2
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Gao J, Bao M, Xing Y, Ding Y, Han T, Wen E, Liu J, Yue S, Wang R, Wang L, Liu J, Zhao S, Huang J, Liu E, Bai L. Mediator subunit MED1 deficiency prevents carbon tetrachloride-induced hepatic fibrosis in mice. Am J Physiol Gastrointest Liver Physiol 2023; 325:G418-G428. [PMID: 37668531 DOI: 10.1152/ajpgi.00076.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 09/06/2023]
Abstract
Mediator subunit mediator 1 (MED1) mediates ligand-dependent binding of the mediator coactivator complex to various nuclear receptors and plays a critical role in embryonic development, lipid and glucose metabolism, liver regeneration, and tumorigenesis. However, the precise role of MED1 in the development of liver fibrosis has been unclear. Here, we showed that MED1 expression was increased in livers from nonalcoholic steatohepatitis (NASH) patients and mice and positively correlated with transforming growth factor β (TGF-β) signaling and profibrotic factors. Upon treatment with carbon tetrachloride (CCl4), hepatic fibrosis was much less in liver-specific MED1 deletion (MED1ΔLiv) mice than in MED1fl/fl littermates. TGF-β/Smad2/3 signaling pathway was inhibited, and gene expression of fibrotic markers, including α-smooth muscle actin (α-SMA), collagen type 1 α 1 (Col1a1), matrix metalloproteinase-2 (Mmp2), and metallopeptidase inhibitor 1 (Timp1) were decreased in livers of MED1ΔLiv mice with CCl4 injection. Transcriptomic analysis revealed that the differentially expressed genes in livers of CCl4-administered MED1ΔLiv mice were enriched in the pathway of oxidoreductase activity, followed by robustly reduced oxidoreductase activity-related genes, such as Gm4756, Txnrd3, and Etfbkmt. More importantly, we found that the reduction of reactive oxygen species (ROS) in MED1 knockdown hepatocytes blocked the activation of TGF-β/Smad2/3 pathway and the expression of fibrotic genes in LX2 cells. These results indicate that MED1 is a positive regulator for hepatic fibrogenesis, and MED1 may be considered as a potential therapeutic target for the regression of liver fibrosis.NEW & NOTEWORTHY In this study, we present the first evidence that liver mediator 1 (MED1) deficiency attenuated carbon tetrachloride-induced hepatic fibrosis in mouse. The underlying mechanism is that MED1 deficiency reduces reactive oxygen species (ROS) production in hepatocytes, thus restricts the activation of TGF-β/Smad2/3 signaling pathway and fibrogenic genes expression in hepatic stellate cells (HSCs). These data suggest that MED1 is an essential regulator for hepatic fibrogenesis, and MED1 may be considered as a potential therapeutic target for liver fibrosis.
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Affiliation(s)
- Jie Gao
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
- School of Biological Science Technology and Engineering, Shaanxi University of Technology, Hanzhong, People's Republic of China
| | - Miaoye Bao
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Yuanming Xing
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Yiming Ding
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Tuo Han
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Ergang Wen
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Jun Liu
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Shaoyun Yue
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
| | - Rong Wang
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Ling Wang
- School of Biological Science Technology and Engineering, Shaanxi University of Technology, Hanzhong, People's Republic of China
| | - Junhui Liu
- Department of Clinical Laboratory, First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, People's Republic of China
| | - Sihai Zhao
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Jiansheng Huang
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Enqi Liu
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Liang Bai
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
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3
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Thaler R, Yoshizaki K, Nguyen T, Fukumoto S, Den Besten P, Bikle DD, Oda Y. Mediator 1 ablation induces enamel-to-hair lineage conversion in mice through enhancer dynamics. Commun Biol 2023; 6:766. [PMID: 37479880 PMCID: PMC10362024 DOI: 10.1038/s42003-023-05105-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 07/06/2023] [Indexed: 07/23/2023] Open
Abstract
Postnatal cell fate is postulated to be primarily determined by the local tissue microenvironment. Here, we find that Mediator 1 (Med1) dependent epigenetic mechanisms dictate tissue-specific lineage commitment and progression of dental epithelia. Deletion of Med1, a key component of the Mediator complex linking enhancer activities to gene transcription, provokes a tissue extrinsic lineage shift, causing hair generation in incisors. Med1 deficiency gives rise to unusual hair growth via primitive cellular aggregates. Mechanistically, we find that MED1 establishes super-enhancers that control enamel lineage transcription factors in dental stem cells and their progenies. However, Med1 deficiency reshapes the enhancer landscape and causes a switch from the dental transcriptional program towards hair and epidermis on incisors in vivo, and in dental epithelial stem cells in vitro. Med1 loss also provokes an increase in the number and size of enhancers. Interestingly, control dental epithelia already exhibit enhancers for hair and epidermal key transcription factors; these transform into super-enhancers upon Med1 loss suggesting that these epigenetic mechanisms cause the shift towards epidermal and hair lineages. Thus, we propose a role for Med1 in safeguarding lineage specific enhancers, highlight the central role of enhancer accessibility in lineage reprogramming and provide insights into ectodermal regeneration.
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Affiliation(s)
- Roman Thaler
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
- Center for Regenerative Medicine, Mayo Clinic, Rochester, MN, USA
| | - Keigo Yoshizaki
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan
| | - Thai Nguyen
- Departments of Medicine and Endocrinology, University of California San Francisco and San Francisco Veterans Affairs Health Center, San Francisco, CA, USA
| | - Satoshi Fukumoto
- Section of Pediatric Dentistry, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan
- Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Pamela Den Besten
- Department of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - Daniel D Bikle
- Departments of Medicine and Endocrinology, University of California San Francisco and San Francisco Veterans Affairs Health Center, San Francisco, CA, USA
| | - Yuko Oda
- Departments of Medicine and Endocrinology, University of California San Francisco and San Francisco Veterans Affairs Health Center, San Francisco, CA, USA.
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4
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Ilchuk LA, Kubekina MV, Okulova YD, Silaeva YY, Tatarskiy VV, Filatov MA, Bruter AV. Genetically Engineered Mice Unveil In Vivo Roles of the Mediator Complex. Int J Mol Sci 2023; 24:ijms24119330. [PMID: 37298278 DOI: 10.3390/ijms24119330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/16/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
The Mediator complex is a multi-subunit protein complex which plays a significant role in the regulation of eukaryotic gene transcription. It provides a platform for the interaction of transcriptional factors and RNA polymerase II, thus coupling external and internal stimuli with transcriptional programs. Molecular mechanisms underlying Mediator functioning are intensively studied, although most often using simple models such as tumor cell lines and yeast. Transgenic mouse models are required to study the role of Mediator components in physiological processes, disease, and development. As constitutive knockouts of most of the Mediator protein coding genes are embryonically lethal, conditional knockouts and corresponding activator strains are needed for these studies. Recently, they have become more easily available with the development of modern genetic engineering techniques. Here, we review existing mouse models for studying the Mediator, and data obtained in corresponding experiments.
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Affiliation(s)
- Leonid A Ilchuk
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Marina V Kubekina
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Yulia D Okulova
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Yulia Yu Silaeva
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, 119334 Moscow, Russia
| | - Victor V Tatarskiy
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, 119334 Moscow, Russia
| | - Maxim A Filatov
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Alexandra V Bruter
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
- Federal State Budgetary Institution "N.N. Blokhin National Medical Research Center of Oncology", Ministry of Health of the Russian Federation, Kashirskoe Sh. 24, 115478 Moscow, Russia
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5
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Fatima M, Gao J, Han T, Ding Y, Zhang Y, Wen E, Jia L, Wang R, Wang W, Zhao S, Bai L, Liu E. MED1 Deficiency in Macrophages Aggravates Isoproterenol-Induced Cardiac Fibrosis in Mice. THE AMERICAN JOURNAL OF PATHOLOGY 2022; 192:1016-1027. [PMID: 35461855 DOI: 10.1016/j.ajpath.2022.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/24/2022] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
Mediator 1 (MED1), a key subunit of the mediator complex, interacts with various nuclear receptors and functions in lipid metabolism and energy homeostasis. Dilated cardiomyopathy-related ventricular dilatation and heart failure have been reported in mice with cardiomyocyte-specific Med1 deficiency. However, the contribution of macrophage-specific MED1 in cardiac remodeling remains unclear. In this study, macrophage-specific Med1 knockout (Med1ΔMac) mice were generated and exposed to isoproterenol (ISO) to induce cardiac fibrosis; these mice showed aggravated cardiac fibrosis compared with Med1fl/fl mice. The levels of expression of marker genes for myofibroblast transdifferentiation [α-smooth muscle actin (SMA)] and of profibrotic genes, including Col1a1, Col3a1, Postn, Mmp2, Timp1, and Fn1, were significantly increased in the cardiac tissues of Med1ΔMac mice with ISO-induced myocardial fibrosis. In particular, the transforming growth factor (TGF)-β-Smad2/3 signaling pathway was activated. In bone marrow-derived and peritoneal macrophages, Med1 deficiency was also associated with elevated levels of expression of proinflammatory genes, including Il6, Tnfa, and Il1b. These findings indicate that macrophage-specific MED1 deficiency may aggravate ISO-induced cardiac fibrosis via the regulation of the TGF-β-SMAD2/3 pathway, and the underlying mechanism may involve MED1 deficiency triggering the activation of inflammatory cytokines in macrophages, which in turn may stimulate phenotypic switch of cardiac fibroblasts and accelerate cardiac fibrosis. Thus, MED1 is a potential therapeutic target for cardiac fibrosis.
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Affiliation(s)
- Mehreen Fatima
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Jie Gao
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Tuo Han
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China
| | - Yiming Ding
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China
| | - Yali Zhang
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Ergang Wen
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Linying Jia
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Rong Wang
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Weirong Wang
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Sihai Zhao
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Liang Bai
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.
| | - Enqi Liu
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.
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6
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Bhardwaj R, Thakur JK, Kumar S. MedProDB: A database of Mediator proteins. Comput Struct Biotechnol J 2021; 19:4165-4176. [PMID: 34527190 PMCID: PMC8342855 DOI: 10.1016/j.csbj.2021.07.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 07/08/2021] [Accepted: 07/24/2021] [Indexed: 12/03/2022] Open
Abstract
Mediator complex is a key component of transcriptional regulation in eukaryotes. Identification of Mediator subunits was done by using computational approaches. Different physicochemical properties, and functions of Mediators were discussed. We have developed first database of Mediator proteins e.g. MedProDB. MedProDB contains different types of search and browse options, and various tools.
In the last three decades, the multi-subunit Mediator complex has emerged as the key component of transcriptional regulation of eukaryotic gene expression. Although there were initial hiccups, recent advancements in bioinformatics tools contributed significantly to in-silico prediction and characterization of Mediator subunits from several organisms belonging to different eukaryotic kingdoms. In this study, we have developed the first database of Mediator proteins named MedProDB with 33,971 Mediator protein entries. Out of those, 12531, 11545, and 9895 sequences belong to metazoans, plants, and fungi, respectively. Apart from the core information consisting of sequence, length, position, organism, molecular weight, and taxonomic lineage, additional information of each Mediator sequence like aromaticity, hydropathy, instability index, isoelectric point, functions, interactions, repeat regions, diseases, sequence alignment to Mediator subunit family, Intrinsically Disordered Regions (IDRs), Post-translation modifications (PTMs), and Molecular Recognition Features (MoRFs) may be of high utility to the users. Furthermore, different types of search and browse options with four different tools namely BLAST, Smith-Waterman Align, IUPred, and MoRF-Chibi_Light are provided at MedProDB to perform different types of analysis. Being a critical component of the transcriptional machinery and regulating almost all the aspects of transcription, it generated lots of interest in structural and functional studies of Mediator functioning. So, we think that the MedProDB database will be very useful for researchers studying the process of transcription. This database is freely available at www.nipgr.ac.in/MedProDB.
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Affiliation(s)
- Rohan Bhardwaj
- Bioinformatics Lab, National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India.,Plant Mediator Lab, National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Jitendra Kumar Thakur
- Plant Mediator Lab, National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India.,Plant Transcription Regulation, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Shailesh Kumar
- Bioinformatics Lab, National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
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Jang Y, Park YK, Lee JE, Wan D, Tran N, Gavrilova O, Ge K. MED1 is a lipogenesis coactivator required for postnatal adipose expansion. Genes Dev 2021; 35:713-728. [PMID: 33888555 PMCID: PMC8091974 DOI: 10.1101/gad.347583.120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/16/2021] [Indexed: 12/28/2022]
Abstract
In this study, Jang et al. investigated the role of MED1 in adipose development and expansion in vivo, and they show that MED1 is not generally required for transcription during adipogenesisin culture and that MED1 is dispensable for adipose development in mice. Instead, MED1 is required for postnatal adipose expansion and the induction of fatty acid and triglyceride synthesis genes after pups switch diet from high-fat maternal milk to carbohydrate-based chow. Their findings identify a cell- and gene-specific regulatory role of MED1 as a lipogenesis coactivator required for postnatal adipose expansion. MED1 often serves as a surrogate of the general transcription coactivator complex Mediator for identifying active enhancers. MED1 is required for phenotypic conversion of fibroblasts to adipocytes in vitro, but its role in adipose development and expansion in vivo has not been reported. Here, we show that MED1 is not generally required for transcription during adipogenesis in culture and that MED1 is dispensable for adipose development in mice. Instead, MED1 is required for postnatal adipose expansion and the induction of fatty acid and triglyceride synthesis genes after pups switch diet from high-fat maternal milk to carbohydrate-based chow. During adipogenesis, MED1 is dispensable for induction of lineage-determining transcription factors (TFs) PPARγ and C/EBPα but is required for lipid accumulation in the late phase of differentiation. Mechanistically, MED1 controls the induction of lipogenesis genes by facilitating lipogenic TF ChREBP- and SREBP1a-dependent recruitment of Mediator to active enhancers. Together, our findings identify a cell- and gene-specific regulatory role of MED1 as a lipogenesis coactivator required for postnatal adipose expansion.
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Affiliation(s)
- Younghoon Jang
- Adipocyte Biology and Gene Regulation Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.,Department of Biology and Chemistry, Changwon National University, Changwon 51140, Korea
| | - Young-Kwon Park
- Adipocyte Biology and Gene Regulation Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ji-Eun Lee
- Adipocyte Biology and Gene Regulation Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Danyang Wan
- Adipocyte Biology and Gene Regulation Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Nhien Tran
- Adipocyte Biology and Gene Regulation Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Oksana Gavrilova
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Kai Ge
- Adipocyte Biology and Gene Regulation Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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8
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Ito K, Schneeberger M, Gerber A, Jishage M, Marchildon F, Maganti AV, Cohen P, Friedman JM, Roeder RG. Critical roles of transcriptional coactivator MED1 in the formation and function of mouse adipose tissues. Genes Dev 2021; 35:729-748. [PMID: 33888560 PMCID: PMC8091968 DOI: 10.1101/gad.346791.120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 03/16/2021] [Indexed: 01/12/2023]
Abstract
In this study, Ito et al. sought to understand the precise roles of MED1, and its various domains, at various stages of adipogenesis and in adipose tissue. Using multiple genetic approaches to assess requirements for MED1 in adipocyte formation and function in mice, they show that MED1 is indeed essential for the differentiation and/or function of both brown and white adipocytes, as its absence in these cells leads to, respectively, defective brown fat function and lipodystrophy. The MED1 subunit has been shown to mediate ligand-dependent binding of the Mediator coactivator complex to multiple nuclear receptors, including the adipogenic PPARγ, and to play an essential role in ectopic PPARγ-induced adipogenesis of mouse embryonic fibroblasts. However, the precise roles of MED1, and its various domains, at various stages of adipogenesis and in adipose tissue have been unclear. Here, after establishing requirements for MED1, including specific domains, for differentiation of 3T3L1 cells and both primary white and brown preadipocytes, we used multiple genetic approaches to assess requirements for MED1 in adipocyte formation, maintenance, and function in mice. We show that MED1 is indeed essential for the differentiation and/or function of both brown and white adipocytes, as its absence in these cells leads to, respectively, defective brown fat function and lipodystrophy. This work establishes MED1 as an essential transcriptional coactivator that ensures homeostatic functions of adipocytes.
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Affiliation(s)
- Keiichi Ito
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Marc Schneeberger
- Laboratory of Molecular Genetics, The Rockefeller University, New York, New York 10065, USA
| | - Alan Gerber
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Miki Jishage
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Francois Marchildon
- Laboratory of Molecular Metabolism, The Rockefeller University, New York, New York 10065, USA
| | - Aarthi V Maganti
- Laboratory of Molecular Metabolism, The Rockefeller University, New York, New York 10065, USA
| | - Paul Cohen
- Laboratory of Molecular Metabolism, The Rockefeller University, New York, New York 10065, USA
| | - Jeffrey M Friedman
- Laboratory of Molecular Genetics, The Rockefeller University, New York, New York 10065, USA
| | - Robert G Roeder
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA
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9
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Zhou J, Singh BK, Ho JP, Lim A, Bruinstroop E, Ohba K, Sinha RA, Yen PM. MED1 mediator subunit is a key regulator of hepatic autophagy and lipid metabolism. Autophagy 2021; 17:4043-4061. [PMID: 33734012 DOI: 10.1080/15548627.2021.1899691] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hepatic macroautophagy/autophagy and fatty acid metabolism are transcriptionally regulated by nuclear receptors (NRs); however, it is not known whether their transcriptional co-activators are involved in autophagy. We thus examined MED1 (mediator complex subunit 1), a key component of the Mediator Complex that directly interacts with NRs, on these processes. We found that MED1 knockdown (KD) in cultured hepatic cells decreased autophagy and mitochondrial activity that was accompanied by decreased transcription of genes involved in these processes. Lipophagy and fatty acid β-oxidation also were impaired. These effects also occurred after thyroid hormone stimulation, nutrient-replete or -deplete conditions, and in liver-specific Med1 KD (Med1 LKD) mice under fed and fasting conditions. Together, these findings showed that Med1 played a key role in hepatic autophagy, mitochondria function, and lipid metabolism under these conditions. Additionally, we identified downregulated hepatic genes in Med1 LKD mice, and subjected them to ChIP Enrichment Analysis. Our findings showed that the transcriptional activity of several NRs and transcription factors (TFs), including PPARA and FOXO1, likely were affected by Med1 LKD. Finally, Med1 expression and autophagy also were decreased in two mouse models of nonalcoholic fatty liver disease (NAFLD) suggesting that decreased Med1 may contribute to hepatosteatosis. In summary, MED1 plays an essential role in regulating hepatic autophagy and lipid oxidation during different hormonal and nutrient conditions. Thus, MED1 may serve as an integrator of multiple transcriptional pathways involved in these metabolic processes.Abbreviations: BAF: bafilomycin A1; db/db mice; Leprdb/db mice; ECAR: extracellular acidification rate; KD: knockdown; MED1: mediator complex subunit 1; NAFLD: nonalcoholic fatty liver disease; OCR: oxygen consumption rate; PPARA/PPARα: peroxisomal proliferator activated receptor alpha; TF: transcription factor; TFEB: transcription factor EB; tf-LC3: tandem fluorescence RFP-GFP-LC3; TG: triglyceride; TH: Thyroid hormone; TR: thyroid hormone receptors; V-ATPase: vacuolar-type H+-ATPase; WDF: Western diet with 15% fructose in drinking water.
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Affiliation(s)
- Jin Zhou
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Brijesh K Singh
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Jia Pei Ho
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Andrea Lim
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Eveline Bruinstroop
- Department of Endocrinology and Metabolism, Amsterdam UMC, Amsterdam, The Netherlands
| | - Kenji Ohba
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Rohit A Sinha
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore.,Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow India
| | - Paul M Yen
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore.,Duke Molecular Physiology Institute and Department of Medicine, Duke University Medical Center, Durham, NC USA
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10
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Lei L, Yang X, Su Y, Zheng H, Liu J, Liu H, Zou Y, Jiao A, Wang X, Zhang C, Zhang X, Zhang J, Zhang D, Zhou X, Shi L, Liu E, Bai L, Sun C, Zhang B. Med1 controls CD8 T cell maintenance through IL-7R-mediated cell survival signalling. J Cell Mol Med 2021; 25:4870-4876. [PMID: 33733611 PMCID: PMC8107092 DOI: 10.1111/jcmm.16465] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/01/2021] [Accepted: 03/03/2021] [Indexed: 12/15/2022] Open
Abstract
Under steady‐state conditions, the pool size of peripheral CD8+ T cells is maintained through turnover and survival. Beyond TCR and IL‐7R signals, the underlying mechanisms are less well understood. In the present study, we found a significant reduction of CD8+ T cell proportion in spleens but not in thymi of mice with T cell‐specific deletion of Mediator Subunit 1 (Med1). A competitive transfer of wild‐type (WT) and Med1‐deficient CD8+ T cells reproduced the phenotype in the same recipients and confirmed intrinsic role of Med1. Furthermore, we observed a comparable degree of migration and proliferation but a significant increase of cell death in Med1‐deficient CD8+ T cells compared with WT counterparts. Finally, Med1‐deficient CD8+ T cells exhibited a decreased expression of interleukin‐7 receptor α (IL‐7Rα), down‐regulation of phosphorylated‐STAT5 (pSTAT5) and Bim up‐regulation. Collectively, our study reveals a novel role of Med1 in the maintenance of CD8+ T cells through IL‐7Rα/STAT5 pathway‐mediated cell survival.
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Affiliation(s)
- Lei Lei
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, China.,Xi'an Key Laboratory of Immune Related Diseases, Xi'an, China
| | - Xiaofeng Yang
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, China.,Xi'an Key Laboratory of Immune Related Diseases, Xi'an, China
| | - Yanhong Su
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Huiqiang Zheng
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Jun Liu
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Haiyan Liu
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Yujing Zou
- Duke University Medical Center, Durham, NC, USA
| | - Anjun Jiao
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Xin Wang
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Cangang Zhang
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Xingzhe Zhang
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Jiahui Zhang
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Dan Zhang
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Xiaobo Zhou
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Lin Shi
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Enqi Liu
- Institute of Cardiovascular Science, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Liang Bai
- Institute of Cardiovascular Science, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Chenming Sun
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, China.,Xi'an Key Laboratory of Immune Related Diseases, Xi'an, China
| | - Baojun Zhang
- Department of Pathogenic Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.,Institute of Infection and Immunity, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, China.,Xi'an Key Laboratory of Immune Related Diseases, Xi'an, China
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11
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Hepatocardiac or Cardiohepatic Interaction: From Traditional Chinese Medicine to Western Medicine. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021; 2021:6655335. [PMID: 33777158 PMCID: PMC7981187 DOI: 10.1155/2021/6655335] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/18/2021] [Accepted: 02/05/2021] [Indexed: 12/16/2022]
Abstract
There is a close relationship between the liver and heart based on "zang-xiang theory," "five-element theory," and "five-zang/five-viscus/five-organ correlation theory" in the theoretical system of Traditional Chinese Medicine (TCM). Moreover, with the development of molecular biology, genetics, immunology, and others, the Modern Medicine indicates the existence of the essential interorgan communication between the liver and heart (the heart and liver). Anatomically and physiologically, the liver and heart are connected with each other primarily via "blood circulation." Pathologically, liver diseases can affect the heart; for example, patients with end-stage liver disease (liver failure/cirrhosis) may develop into "cirrhotic cardiomyopathy," and nonalcoholic fatty liver disease (NAFLD) may promote the development of cardiovascular diseases via multiple molecular mechanisms. In contrast, heart diseases can affect the liver, heart failure may lead to cardiogenic hypoxic hepatitis and cardiac cirrhosis, and atrial fibrillation (AF) markedly alters the hepatic gene expression profile and induces AF-related hypercoagulation. The heart can also influence liver metabolism via certain nonsecretory cardiac gene-mediated multiple signals. Moreover, organokines are essential mediators of organ crosstalk, e.g., cardiomyokines link the heart to the liver, while hepatokines link the liver to the heart. Therefore, both TCM and Western Medicine, and both the basic research studies and the clinical practices, all indicate that there exist essential "heart-liver axes" and "liver-heart axes." To investigate the organ interactions between the liver and heart (the heart and liver) will help us broaden and deepen our understanding of the pathogenesis of both liver and heart diseases, thus improving the strategies of prevention and treatment in the future.
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12
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Signorelli P, Pivari F, Barcella M, Merelli I, Zulueta A, Dei Cas M, Rosso L, Ghidoni R, Caretti A, Paroni R, Mingione A. Myriocin modulates the altered lipid metabolism and storage in cystic fibrosis. Cell Signal 2021; 81:109928. [PMID: 33482299 DOI: 10.1016/j.cellsig.2021.109928] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/13/2021] [Accepted: 01/13/2021] [Indexed: 12/12/2022]
Abstract
Cystic fibrosis (CF) is a hereditary disease mostly related to ΔF508 CFTR mutation causing a proteinopathy that is characterized by multiple organ dysfunction, primarily lungs chronic inflammation, and infection. Defective autophagy and accumulation of the inflammatory lipid ceramide have been proposed as therapeutic targets. Accumulation of lipids and cholesterol was reported in the airways of CF patients, together with altered triglycerides and cholesterol levels in plasma, thus suggesting a disease-related dyslipidemia. Myriocin, an inhibitor of sphingolipids synthesis, significantly reduces inflammation and activates TFEB-induced response to stress, enhancing fatty acids oxidation and promoting autophagy. Myriocin ameliorates the response against microbial infection in CF models and patients' monocytes. Here we show that CF broncho-epithelial cells exhibit an altered distribution of intracellular lipids. We demonstrated that lipid accumulation is supported by an enhanced synthesis of fatty acids containing molecules and that Myriocin is able to reduce such accumulation. Moreover, Myriocin modulated the transcriptional profile of CF cells in order to restore autophagy, activate an anti-oxidative response, stimulate lipid metabolism and reduce lipid peroxidation. Moreover, lipid storage may be altered in CF cells, since we observed a reduced expression of lipid droplets related proteins named perilipin 3 and 5 and seipin. To note, Myriocin up-regulates the expression of genes that are involved in lipid droplets biosynthesis and maturation. We suggest that targeting sphingolipids de novo synthesis may counteract lipids accumulation by modulating CF altered transcriptional profile, thus restoring autophagy and lipid metabolism homeostasis.
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Affiliation(s)
- Paola Signorelli
- Biochemistry and Molecular Biology Laboratory, Department of Health Science, University of Milan, Milan, Italy; "Aldo Ravelli" Center for Neurotechnology and Experimental Brain Therapeutics, University of Milan, Milan, Italy
| | - Francesca Pivari
- Biochemistry and Molecular Biology Laboratory, Department of Health Science, University of Milan, Milan, Italy
| | - Matteo Barcella
- Department of Health Sciences, University of Milan, Milan, Italy
| | - Ivan Merelli
- Institute for Biomedical Technologies, National Research Council of Italy, Milan, Italy
| | - Aida Zulueta
- Biochemistry and Molecular Biology Laboratory, Department of Health Science, University of Milan, Milan, Italy
| | - Michele Dei Cas
- Laboratory of Clinical Biochemistry and Mass Spectrometry, Department of Health Sciences, University of Milan, Milan, Italy
| | - Lorenzo Rosso
- Thoracic surgery and transplantation Unit, Fondazione IRCCS Ca Granda Ospedale Maggiore Policlinico, Health Sciences Department, University of Milan, Milan, Italy
| | - Riccardo Ghidoni
- Biochemistry and Molecular Biology Laboratory, Department of Health Science, University of Milan, Milan, Italy; "Aldo Ravelli" Center for Neurotechnology and Experimental Brain Therapeutics, University of Milan, Milan, Italy
| | - Anna Caretti
- Biochemistry and Molecular Biology Laboratory, Department of Health Science, University of Milan, Milan, Italy
| | - Rita Paroni
- Laboratory of Clinical Biochemistry and Mass Spectrometry, Department of Health Sciences, University of Milan, Milan, Italy
| | - Alessandra Mingione
- Biochemistry and Molecular Biology Laboratory, Department of Health Science, University of Milan, Milan, Italy; "Aldo Ravelli" Center for Neurotechnology and Experimental Brain Therapeutics, University of Milan, Milan, Italy.
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13
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Oda Y, Nguyen T, Hata A, Meyer MB, Pike JW, Bikle DD. Deletion of Mediator 1 suppresses TGFβ signaling leading to changes in epidermal lineages and regeneration. PLoS One 2020; 15:e0238076. [PMID: 32857768 PMCID: PMC7455038 DOI: 10.1371/journal.pone.0238076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 08/08/2020] [Indexed: 12/27/2022] Open
Abstract
Epidermal lineages and injury induced regeneration are controlled by transcriptional programs coordinating cellular signaling and epigenetic regulators, but the mechanism remains unclear. Previous studies showed that conditional deletion of the transcriptional coactivator Mediator 1 (Med1) changes epidermal lineages and accelerates wound re-epithelialization. Here, we studied a molecular mechanism by which Med1 facilitates these processes, in particular, by focusing on TGFβ signaling through genome wide transcriptome analysis. The expression of the TGF ligands (Tgfβ1/β2) and their downstream target genes is decreased in both normal and wounded Med1 null skin. Med1 silencing in cultured keratinocytes likewise reduces the expression of the ligands (TGFβ1/β2) and diminishes activity of TGFβ signaling as shown by decreased p-Smad2/3. Silencing Med1 increases keratinocyte proliferation and migration in vitro. Epigenetic studies using chromatin immuno-precipitation and next generation DNA sequencing reveals that Med1 regulates transcription of TGFβ components by forming large clusters of enhancers called super-enhancers at the regulatory regions of the TGFβ ligand and SMAD3 genes. These results demonstrate that Med1 is required for the maintenance of the TGFβ signaling pathway. Finally, we show that pharmacological inhibition of TGFβ signaling enhances epidermal lineages and accelerates wound re-epithelialization in skin similar to that seen in the Med1 null mice, providing new insights into epidermal regeneration.
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Affiliation(s)
- Yuko Oda
- Departments of Medicine and Endocrinology, University of California San Francisco and Veterans Affairs Medical Center San Francisco, San Francisco, CA, United States of America
- * E-mail:
| | - Thai Nguyen
- Departments of Medicine and Endocrinology, University of California San Francisco and Veterans Affairs Medical Center San Francisco, San Francisco, CA, United States of America
| | - Akiko Hata
- Cardiovascular Research Institute, University of California, San Francisco, CA, United States of America
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America
| | - Mark B. Meyer
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - J. Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Daniel D. Bikle
- Departments of Medicine and Endocrinology, University of California San Francisco and Veterans Affairs Medical Center San Francisco, San Francisco, CA, United States of America
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14
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Li Y, Chen M, Zhou Y, Tang C, Zhang W, Zhong Y, Chen Y, Zhou H, Sheng L. NIK links inflammation to hepatic steatosis by suppressing PPARα in alcoholic liver disease. Theranostics 2020; 10:3579-3593. [PMID: 32206109 PMCID: PMC7069072 DOI: 10.7150/thno.40149] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 01/31/2020] [Indexed: 12/13/2022] Open
Abstract
Background: Inflammation and steatosis are the main pathological features of alcoholic liver disease (ALD), in which, inflammation is one of the critical drivers for the initiation and development of alcoholic steatosis. NIK, an inflammatory pathway component activated by inflammatory cytokines, was suspected to link inflammation to hepatic steatosis during ALD. However, the underlying pathogenesis is not well-elucidated. Methods: Alcoholic steatosis was induced in mice by chronic-plus-binge ethanol feeding. Both the loss- and gain-of-function experiments by the hepatocyte-specific deletion, pharmacological inhibition and adenoviral transfection of NIK were utilized to elucidate the role of NIK in alcoholic steatosis. Rate of fatty acid oxidation was assessed in vivo and in vitro. PPARα agonists or antagonists of MEK1/2 and ERK1/2 were used to identify the NIK-induced regulation of PPARα, MEK1/2, and ERK1/2. The potential interactions between NIK, MEK1/2, ERK1/2 and PPARα and the phosphorylation of PPARα were clarified by immunoprecipitation, immunoblotting and far-western blotting analysis. Results: Hepatocyte-specific deletion of NIK protected mice from alcoholic steatosis by sustaining hepatic fatty acid oxidation. Moreover, overexpression of NIK contributed to hepatic lipid accumulation with disrupted fatty acid oxidation. The pathological effect of NIK in ALD may be attributed to the suppression of PPARα, the main controller of fatty acid oxidation in the liver, because PPARα agonists reversed NIK-mediated hepatic steatosis and malfunction of fatty acid oxidation. Mechanistically, NIK recruited MEK1/2 and ERK1/2 to form a complex that catalyzed the inhibitory phosphorylation of PPARα. Importantly, pharmacological intervention against NIK significantly attenuated alcoholic steatosis in ethanol-fed mice. Conclusions: NIK targeting PPARα via MEK1/2 and ERK1/2 disrupts hepatic fatty acid oxidation and exhibits high value in ALD therapy.
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Affiliation(s)
- Yaru Li
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Mingming Chen
- Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, Jiangsu 210009, China
| | - Yu Zhou
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Chuanfeng Tang
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Wen Zhang
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Ying Zhong
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yadong Chen
- Laboratory of Molecular Design and Drug Discovery, School of Science, China Pharmaceutical University, Nanjing, Jiangsu 211198, China
| | - Hong Zhou
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Liang Sheng
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Key Laboratory of Rare Metabolic Diseases, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Department of Rehabilitation Medicine, Jiangsu Province People's Hospital and Nanjing Medical University First Affiliated Hospital, Nanjing, Jiangsu 210029, China
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15
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Gene Expression Profiles Induced by a Novel Selective Peroxisome Proliferator-Activated Receptor α Modulator (SPPARMα) Pemafibrate. Int J Mol Sci 2019; 20:ijms20225682. [PMID: 31766193 PMCID: PMC6888257 DOI: 10.3390/ijms20225682] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/05/2019] [Accepted: 11/11/2019] [Indexed: 12/16/2022] Open
Abstract
Pemafibrate is the first clinically-available selective peroxisome proliferator-activated receptor α modulator (SPPARMα) that has been shown to effectively improve hypertriglyceridemia and low high-density lipoprotein cholesterol (HDL-C) levels. Global gene expression analysis reveals that the activation of PPARα by pemafibrate induces fatty acid (FA) uptake, binding, and mitochondrial or peroxisomal oxidation as well as ketogenesis in mouse liver. Pemafibrate most profoundly induces HMGCS2 and PDK4, which regulate the rate-limiting step of ketogenesis and glucose oxidation, respectively, compared to other fatty acid metabolic genes in human hepatocytes. This suggests that PPARα plays a crucial role in nutrient flux in the human liver. Additionally, pemafibrate induces clinically favorable genes, such as ABCA1, FGF21, and VLDLR. Furthermore, pemafibrate shows anti-inflammatory effects in vascular endothelial cells. Pemafibrate is predicted to exhibit beneficial effects in patients with atherogenic dyslipidemia and diabetic microvascular complications.
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16
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Zhang M, Yang S, Shi M, Zhang S, Zhang T, Li Y, Xu S, Cha M, Meng Y, Lin S, Yu J, Li X, Mu A, Hu D, Liu S. Regulatory Roles of Peroxisomal Metabolic Pathways Involved in Musk Secretion in Muskrats. J Membr Biol 2019; 252:61-75. [PMID: 30604068 DOI: 10.1007/s00232-018-0057-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 12/10/2018] [Indexed: 11/30/2022]
Abstract
In this study, we analyzed the main components of muskrat musk by gas chromatography-mass spectrometry, the results showed that muskrat musk contained fatty acids (29.32%), esters (31.89%), cholesterol (4.38%), cyclic ketones (16.31%), alcohols (6.42%) and other compounds, among which 9-octadecenoic acid accounted for 4.89%. We also analyzed the genes of the metabolic pathway in the scent gland at the transcriptomic level during musk-secreting and non-secreting seasons by RNA-seq (RNA sequencing). We detected 21 genes in the peroxisomal metabolic pathways, including PEX14(peroxin-14) and ACOX3(acyl-CoA oxidase), which exhibited significant differential expression between the musk-secreting season and the non-secreting season (p < 0.05). The RNA-seq results for these genes were validated by reverse transcription PCR(RT-PCR) for both seasons. In addition, we examined changes in the composition of muskrat musk from the glandular cells of scent glands cultured in vitro after RNA interference-mediated silencing of 2 differentially expressed genes, ACOX3 and HSD17B4(D-bifunctional protein, DBP). The 9-Octadecenoic acid content in muskrat musk decreased significantly following the silencing of ACOX3 and HSD17B4(D-bifunctional protein, DBP). These results suggest that peroxisomal metabolic pathways play important roles in the regulation of musk secretion in scent glands in the muskrat.
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Affiliation(s)
- Meishan Zhang
- College of Nature Conservation, Beijing Forestry University, No.35, Qinghua East Road, Haidian District, Beijing, 100083, People's Republic of China
| | - Shuang Yang
- College of Nature Conservation, Beijing Forestry University, No.35, Qinghua East Road, Haidian District, Beijing, 100083, People's Republic of China
| | - Minghui Shi
- College of Nature Conservation, Beijing Forestry University, No.35, Qinghua East Road, Haidian District, Beijing, 100083, People's Republic of China
| | - Shumiao Zhang
- Beijing Milu Ecological Research Center, Beijing, 100076, People's Republic of China
| | - Tianxiang Zhang
- College of Nature Conservation, Beijing Forestry University, No.35, Qinghua East Road, Haidian District, Beijing, 100083, People's Republic of China
| | - Yimeng Li
- College of Nature Conservation, Beijing Forestry University, No.35, Qinghua East Road, Haidian District, Beijing, 100083, People's Republic of China
| | - Shanghua Xu
- College of Nature Conservation, Beijing Forestry University, No.35, Qinghua East Road, Haidian District, Beijing, 100083, People's Republic of China
| | - Muha Cha
- College of Nature Conservation, Beijing Forestry University, No.35, Qinghua East Road, Haidian District, Beijing, 100083, People's Republic of China
| | - Yuping Meng
- Beijing Milu Ecological Research Center, Beijing, 100076, People's Republic of China
| | - Shaobi Lin
- Zhangzhou Pien Tze Huang Pharmaceutical Co., Ltd, Fujian, 363700, People's Republic of China
| | - Juan Yu
- Zhangzhou Pien Tze Huang Pharmaceutical Co., Ltd, Fujian, 363700, People's Republic of China
| | - Xuxin Li
- Zhangzhou Pien Tze Huang Pharmaceutical Co., Ltd, Fujian, 363700, People's Republic of China
| | - Ali Mu
- Qingdao Feed and Veterinary Drug Inspection Station, Qingdao, 266000, People's Republic of China
| | - Defu Hu
- College of Nature Conservation, Beijing Forestry University, No.35, Qinghua East Road, Haidian District, Beijing, 100083, People's Republic of China.
| | - Shuqiang Liu
- College of Nature Conservation, Beijing Forestry University, No.35, Qinghua East Road, Haidian District, Beijing, 100083, People's Republic of China. .,Zhangzhou Pien Tze Huang Pharmaceutical Co., Ltd, Fujian, 363700, People's Republic of China.
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17
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Shete V, Liu N, Jia Y, Viswakarma N, Reddy JK, Thimmapaya B. Mouse Cardiac Pde1C Is a Direct Transcriptional Target of Pparα. Int J Mol Sci 2018; 19:ijms19123704. [PMID: 30469494 PMCID: PMC6321386 DOI: 10.3390/ijms19123704] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/16/2018] [Accepted: 11/16/2018] [Indexed: 12/29/2022] Open
Abstract
Phosphodiesterase 1C (PDE1C) is expressed in mammalian heart and regulates cardiac functions by controlling levels of second messenger cyclic AMP and cyclic GMP (cAMP and cGMP, respectively). However, molecular mechanisms of cardiac Pde1c regulation are currently unknown. In this study, we demonstrate that treatment of wild type mice and H9c2 myoblasts with Wy-14,643, a potent ligand of nuclear receptor peroxisome-proliferator activated receptor alpha (PPARα), leads to elevated cardiac Pde1C mRNA and cardiac PDE1C protein, which correlate with reduced levels of cAMP. Furthermore, using mice lacking either Pparα or cardiomyocyte-specific Med1, the major subunit of Mediator complex, we show that Wy-14,643-mediated Pde1C induction fails to occur in the absence of Pparα and Med1 in the heart. Finally, using chromatin immunoprecipitation assays we demonstrate that PPARα binds to the upstream Pde1C promoter sequence on two sites, one of which is a palindrome sequence (agcTAGGttatcttaacctagc) that shows a robust binding. Based on these observations, we conclude that cardiac Pde1C is a direct transcriptional target of PPARα and that Med1 may be required for the PPARα mediated transcriptional activation of cardiac Pde1C.
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Affiliation(s)
- Varsha Shete
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Ning Liu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Yuzhi Jia
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Navin Viswakarma
- Department of Surgery, Division of Surgical Oncology, University of Illinois at Chicago, Chicago, IL 60612, USA.
| | - Janardan K Reddy
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Bayar Thimmapaya
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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18
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Martinez MF, Medrano S, Brown RI, Tufan T, Shang S, Bertoncello N, Guessoum O, Adli M, Belyea BC, Sequeira-Lopez MLS, Gomez RA. Super-enhancers maintain renin-expressing cell identity and memory to preserve multi-system homeostasis. J Clin Invest 2018; 128:4787-4803. [PMID: 30130256 PMCID: PMC6205391 DOI: 10.1172/jci121361] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/14/2018] [Indexed: 02/06/2023] Open
Abstract
Renin cells are crucial for survival - they control fluid-electrolyte and blood pressure homeostasis, vascular development, regeneration, and oxygen delivery to tissues. During embryonic development, renin cells are progenitors for multiple cell types that retain the memory of the renin phenotype. When there is a threat to survival, those descendants are transformed and reenact the renin phenotype to restore homeostasis. We tested the hypothesis that the molecular memory of the renin phenotype resides in unique regions and states of these cells' chromatin. Using renin cells at various stages of stimulation, we identified regions in the genome where the chromatin is open for transcription, mapped histone modifications characteristic of active enhancers such as H3K27ac, and tracked deposition of transcriptional activators such as Med1, whose deletion results in ablation of renin expression and low blood pressure. Using the rank ordering of super-enhancers, epigenetic rewriting, and enhancer deletion analysis, we found that renin cells harbor a unique set of super-enhancers that determine their identity. The most prominent renin super-enhancer may act as a chromatin sensor of signals that convey the physiologic status of the organism, and is responsible for the transformation of renin cell descendants to the renin phenotype, a fundamental process to ensure homeostasis.
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Affiliation(s)
| | | | | | - Turan Tufan
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Stephen Shang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | | | - Omar Guessoum
- Child Health Research Center
- Department of Pediatrics
- Department of Biology, and
| | - Mazhar Adli
- Child Health Research Center
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | | | | | - R. Ariel Gomez
- Child Health Research Center
- Department of Pediatrics
- Department of Biology, and
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Amoasii L, Olson EN, Bassel-Duby R. Control of Muscle Metabolism by the Mediator Complex. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a029843. [PMID: 28432117 DOI: 10.1101/cshperspect.a029843] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Exercise represents an energetic challenge to whole-body homeostasis. In skeletal muscle, exercise activates a variety of signaling pathways that culminate in the nucleus to regulate genes involved in metabolism and contractility; however, much remains to be learned about the transcriptional effectors of exercise. Mediator is a multiprotein complex that links signal-dependent transcription factors and other transcriptional regulators with the basal transcriptional machinery, thereby serving as a transcriptional "hub." In this article, we discuss recent studies highlighting the role of Mediator subunits in metabolic regulation and glucose metabolism, as well as exercise responsiveness. Elucidation of the roles of Mediator subunits in metabolic control has revealed new mechanisms and molecular targets for the modulation of metabolism and metabolic disorders.
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Affiliation(s)
- Leonela Amoasii
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
| | - Eric N Olson
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
| | - Rhonda Bassel-Duby
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
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20
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Ranjan A, Ansari SA. Therapeutic potential of Mediator complex subunits in metabolic diseases. Biochimie 2017; 144:41-49. [PMID: 29061530 DOI: 10.1016/j.biochi.2017.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/16/2017] [Indexed: 01/16/2023]
Abstract
The multisubunit Mediator is an evolutionary conserved transcriptional coregulatory complex in eukaryotes. It is needed for the transcriptional regulation of gene expression in general as well as in a gene specific manner. Mediator complex subunits interact with different transcription factors as well as components of RNA Pol II transcription initiation complex and in doing so act as a bridge between gene specific transcription factors and general Pol II transcription machinery. Specific interaction of various Mediator subunits with nuclear receptors (NRs) and other transcription factors involved in metabolism has been reported in different studies. Evidences indicate that ligand-activated NRs recruit Mediator complex for RNA Pol II-dependent gene transcription. These NRs have been explored as therapeutic targets in different metabolic diseases; however, they show side-effects as targets due to their overlapping involvement in different signaling pathways. Here we discuss the interaction of various Mediator subunits with transcription factors involved in metabolism and whether specific interaction of these transcription factors with Mediator subunits could be potentially utilized as therapeutic strategy in a variety of metabolic diseases.
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Affiliation(s)
- Amol Ranjan
- Stowers Institute for Medical Research, 1000 E, 50th Street, Kansas City, MO, 64110, USA
| | - Suraiya A Ansari
- Department of Biochemistry, College of Medicine and Health Sciences, UAE University, AlAin, Abu Dhabi, United Arab Emirates.
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Bai L, Li Z, Li Q, Guan H, Zhao S, Liu R, Wang R, Zhang J, Jia Y, Fan J, Wang N, Reddy JK, Shyy JYJ, Liu E. Mediator 1 Is Atherosclerosis Protective by Regulating Macrophage Polarization. Arterioscler Thromb Vasc Biol 2017. [PMID: 28642237 DOI: 10.1161/atvbaha.117.309672] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE MED1 (mediator 1) interacts with transcription factors to regulate transcriptional machinery. The role of MED1 in macrophage biology and the relevant disease state remains to be investigated. APPROACH AND RESULTS To study the molecular mechanism by which MED1 regulates the M1/M2 phenotype switch of macrophage and the effect on atherosclerosis, we generated MED1/apolipoprotein E (ApoE) double-deficient (MED1ΔMac/ApoE-/-) mice and found that atherosclerosis was greater in MED1ΔMac/ApoE-/- mice than in MED1fl/fl/ApoE-/- littermates. The gene expression of M1 markers was increased and that of M2 markers decreased in both aortic wall and peritoneal macrophages from MED1ΔMac/ApoE-/- mice, whereas MED1 overexpression rectified the changes in M1/M2 expression. Moreover, LDLR (low-density lipoprotein receptor)-deficient mice received bone marrow from MED1ΔMac mice showed greater atherosclerosis. Mechanistically, MED1 ablation decreased the binding of PPARγ (peroxisome proliferator-activated receptor γ) and enrichment of H3K4me1 and H3K27ac to upstream region of M2 marker genes. Furthermore, interleukin 4 induction of PPARγ and MED1 increased the binding of PPARγ or MED1 to the PPAR response elements of M2 marker genes. CONCLUSIONS Our data suggest that MED1 is required for the PPARγ-mediated M2 phenotype switch, with M2 marker genes induced but M1 marker genes suppressed. MED1 in macrophages has an antiatherosclerotic role via PPARγ-regulated transactivation.
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Affiliation(s)
- Liang Bai
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Zhao Li
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Qianwei Li
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Hua Guan
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Sihai Zhao
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Ruihan Liu
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Rong Wang
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Jin Zhang
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Yuzhi Jia
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Jianglin Fan
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Nanping Wang
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - Janardan K Reddy
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.)
| | - John Y-J Shyy
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.).
| | - Enqi Liu
- From the Research Institute of Atherosclerotic Disease, Health Science Center and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Laboratory Animal Center, Health Science Center (L.B., Q.L., H.G., S.Z., R.L., R.W., E.L.), Cardiovascular Research Center, School of Basic Medical Sciences, Health Science Center (L.B., Z.L., J.Z., N.W., J.Y.-J.S.), Xi'an Jiaotong University, Shaanxi, China; Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL (Y.J., J.K.R.); Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Japan (J.F.); and Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (J.Y.-J.S.).
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Spitler KM, Ponce JM, Oudit GY, Hall DD, Grueter CE. Cardiac Med1 deletion promotes early lethality, cardiac remodeling, and transcriptional reprogramming. Am J Physiol Heart Circ Physiol 2017; 312:H768-H780. [PMID: 28159809 PMCID: PMC5407164 DOI: 10.1152/ajpheart.00728.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/30/2017] [Accepted: 01/30/2017] [Indexed: 12/18/2022]
Abstract
The mediator complex, a multisubunit nuclear complex, plays an integral role in regulating gene expression by acting as a bridge between transcription factors and RNA polymerase II. Genetic deletion of mediator subunit 1 (Med1) results in embryonic lethality, due in large part to impaired cardiac development. We first established that Med1 is dynamically expressed in cardiac development and disease, with marked upregulation of Med1 in both human and murine failing hearts. To determine if Med1 deficiency protects against cardiac stress, we generated two cardiac-specific Med1 knockout mouse models in which Med1 is conditionally deleted (Med1cKO mice) or inducibly deleted in adult mice (Med1cKO-MCM mice). In both models, cardiac deletion of Med1 resulted in early lethality accompanied by pronounced changes in cardiac function, including left ventricular dilation, decreased ejection fraction, and pathological structural remodeling. We next defined how Med1 deficiency alters the cardiac transcriptional profile using RNA-sequencing analysis. Med1cKO mice demonstrated significant dysregulation of genes related to cardiac metabolism, in particular genes that are coordinated by the transcription factors Pgc1α, Pparα, and Errα. Consistent with the roles of these transcription factors in regulation of mitochondrial genes, we observed significant alterations in mitochondrial size, mitochondrial gene expression, complex activity, and electron transport chain expression under Med1 deficiency. Taken together, these data identify Med1 as an important regulator of vital cardiac gene expression and maintenance of normal heart function.NEW & NOTEWORTHY Disruption of transcriptional gene expression is a hallmark of dilated cardiomyopathy; however, its etiology is not well understood. Cardiac-specific deletion of the transcriptional coactivator mediator subunit 1 (Med1) results in dilated cardiomyopathy, decreased cardiac function, and lethality. Med1 deletion disrupted cardiac mitochondrial and metabolic gene expression patterns.
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Affiliation(s)
- Kathryn M Spitler
- Division of Cardiovascular Medicine, Department of Internal Medicine, Francois M. Abboud Cardiovascular Research Center, Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa; and
| | - Jessica M Ponce
- Division of Cardiovascular Medicine, Department of Internal Medicine, Francois M. Abboud Cardiovascular Research Center, Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa; and
| | - Gavin Y Oudit
- Mazankowski Alberta Heart Institute Canada Research Chair in Heart Failure, Division of Cardiology, Walter Mackenzie Health Sciences Centre, Edmonton, Alberta, Canada
| | - Duane D Hall
- Division of Cardiovascular Medicine, Department of Internal Medicine, Francois M. Abboud Cardiovascular Research Center, Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa; and
| | - Chad E Grueter
- Division of Cardiovascular Medicine, Department of Internal Medicine, Francois M. Abboud Cardiovascular Research Center, Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa; and
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23
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Li Y, Mao H, Xu Y, Li X, Pan L, Wu X, Li Y, Li Y, He J. Application research on PPARα-transgenic mice in preclinical safety evaluation of gemfibrozil. Toxicol Res (Camb) 2017; 6:98-104. [PMID: 30090481 PMCID: PMC6061148 DOI: 10.1039/c6tx00271d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 11/04/2016] [Indexed: 12/19/2022] Open
Abstract
To explore the feasibility of peroxisome proliferator-activated receptor (PPAR)α transgenic mice applying in preclinical safety evaluation for peroxisome proliferators (PPs). Both PPARα transgenic mice and C57BL/6J mice were assigned as treated groups (PT and CT groups) and control groups (PC and CC groups). Gemfibrozil was administered into treated groups for 4 weeks. Body weight, blood biochemistry, enzyme activity and histological examinations were performed at scheduled time. The results showed that significant hypolipidaemic effects were induced in the treated groups after gemfibrozil treatment whereas the changes of non-esterified fatty acid and high density lipoproteincholesterol were different between the two treated groups. All the enzyme activities examined increased significantly in PT and CT groups except catalase which displayed no obvious change in the PT group. Pathology results showed a significant increase of the liver weight and the liver weight ratio in the CT group while no obvious changes were observed in the PT group. Hypertrophy of hepatocytes was discovered in CT and PT groups in histological examination, while the extent and incidence of hepatocyte hypertrophy in the CT group were higher than those in the PT group. The data suggest that PPARα transgenic mice could serve as a useful tool for preclinical safety assessment of PP drugs.
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Affiliation(s)
- Yan Li
- National Institute for Nutrition and Health , Chinese Center for Disease Control and Prevention , Beijing 100050 , Beijing , China
| | - Hongmei Mao
- National Institute for Nutrition and Health , Chinese Center for Disease Control and Prevention , Beijing 100050 , Beijing , China
| | - Yanfeng Xu
- Institute of Laboratory Animal Sciences , Chinese Academy of Medical Science and Peking Union Medical College , Beijing 100050 , Beijing , China .
| | - Xiaocen Li
- Institute of Laboratory Animal Sciences , Chinese Academy of Medical Science and Peking Union Medical College , Beijing 100050 , Beijing , China .
| | - Lishan Pan
- Institute of Laboratory Animal Sciences , Chinese Academy of Medical Science and Peking Union Medical College , Beijing 100050 , Beijing , China .
| | - Xin Wu
- Institute of Laboratory Animal Sciences , Chinese Academy of Medical Science and Peking Union Medical College , Beijing 100050 , Beijing , China .
| | - Yang Li
- Institute of Laboratory Animal Sciences , Chinese Academy of Medical Science and Peking Union Medical College , Beijing 100050 , Beijing , China .
| | - Yi Li
- Institute of Laboratory Animal Sciences , Chinese Academy of Medical Science and Peking Union Medical College , Beijing 100050 , Beijing , China .
| | - Jun He
- Institute of Laboratory Animal Sciences , Chinese Academy of Medical Science and Peking Union Medical College , Beijing 100050 , Beijing , China .
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Regulation of metabolism by the Mediator complex. BIOPHYSICS REPORTS 2016; 2:69-77. [PMID: 28018965 PMCID: PMC5138257 DOI: 10.1007/s41048-016-0031-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 02/15/2016] [Indexed: 01/11/2023] Open
Abstract
The Mediator complex was originally discovered in yeast, but it is conserved in all eukaryotes. Its best-known function is to regulate RNA polymerase II-dependent gene transcription. Although the mechanisms by which the Mediator complex regulates transcription are often complicated by the context-dependent regulation, this transcription cofactor complex plays a pivotal role in numerous biological pathways. Biochemical, molecular, and physiological studies using cancer cell lines or model organisms have established the current paradigm of the Mediator functions. However, the physiological roles of the mammalian Mediator complex remain poorly defined, but have attracted a great interest in recent years. In this short review, we will summarize some of the reported functions of selective Mediator subunits in the regulation of metabolism. These intriguing findings suggest that the Mediator complex may be an important player in nutrient sensing and energy balance in mammals.
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Jia Y, Chang HC, Schipma MJ, Liu J, Shete V, Liu N, Sato T, Thorp EB, Barger PM, Zhu YJ, Viswakarma N, Kanwar YS, Ardehali H, Thimmapaya B, Reddy JK. Cardiomyocyte-Specific Ablation of Med1 Subunit of the Mediator Complex Causes Lethal Dilated Cardiomyopathy in Mice. PLoS One 2016; 11:e0160755. [PMID: 27548259 PMCID: PMC4993490 DOI: 10.1371/journal.pone.0160755] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/25/2016] [Indexed: 11/19/2022] Open
Abstract
Mediator, an evolutionarily conserved multi-protein complex consisting of about 30 subunits, is a key component of the polymerase II mediated gene transcription. Germline deletion of the Mediator subunit 1 (Med1) of the Mediator in mice results in mid-gestational embryonic lethality with developmental impairment of multiple organs including heart. Here we show that cardiomyocyte-specific deletion of Med1 in mice (csMed1-/-) during late gestational and early postnatal development by intercrossing Med1fl/fl mice to α-MyHC-Cre transgenic mice results in lethality within 10 days after weaning due to dilated cardiomyopathy-related ventricular dilation and heart failure. The csMed1-/- mouse heart manifests mitochondrial damage, increased apoptosis and interstitial fibrosis. Global gene expression analysis revealed that loss of Med1 in heart down-regulates more than 200 genes including Acadm, Cacna1s, Atp2a2, Ryr2, Pde1c, Pln, PGC1α, and PGC1β that are critical for calcium signaling, cardiac muscle contraction, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy and peroxisome proliferator-activated receptor regulated energy metabolism. Many genes essential for oxidative phosphorylation and proper mitochondrial function such as genes coding for the succinate dehydrogenase subunits of the mitochondrial complex II are also down-regulated in csMed1-/- heart contributing to myocardial injury. Data also showed up-regulation of about 180 genes including Tgfb2, Ace, Atf3, Ctgf, Angpt14, Col9a2, Wisp2, Nppa, Nppb, and Actn1 that are linked to cardiac muscle contraction, cardiac hypertrophy, cardiac fibrosis and myocardial injury. Furthermore, we demonstrate that cardiac specific deletion of Med1 in adult mice using tamoxifen-inducible Cre approach (TmcsMed1-/-), results in rapid development of cardiomyopathy and death within 4 weeks. We found that the key findings of the csMed1-/- studies described above are highly reproducible in TmcsMed1-/- mouse heart. Collectively, these observations suggest that Med1 plays a critical role in the maintenance of heart function impacting on multiple metabolic, compensatory and reparative pathways with a likely therapeutic potential in the management of heart failure.
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MESH Headings
- Animals
- Apoptosis
- Cadherins/genetics
- Cadherins/metabolism
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Calcium Signaling
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/metabolism
- Cardiomyopathy, Dilated/pathology
- Cyclic Nucleotide Phosphodiesterases, Type 1/genetics
- Cyclic Nucleotide Phosphodiesterases, Type 1/metabolism
- Embryo, Mammalian
- Energy Metabolism
- Female
- Gene Deletion
- Gene Expression Profiling
- Gene Expression Regulation
- Genes, Lethal
- Gestational Age
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/pathology
- Mediator Complex Subunit 1/deficiency
- Mediator Complex Subunit 1/genetics
- Mice
- Mice, Knockout
- Mitochondria/metabolism
- Mitochondria/pathology
- Myocardial Contraction
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Peroxisome Proliferator-Activated Receptors/genetics
- Peroxisome Proliferator-Activated Receptors/metabolism
- Pregnancy
- Ryanodine Receptor Calcium Release Channel/genetics
- Ryanodine Receptor Calcium Release Channel/metabolism
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
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Affiliation(s)
- Yuzhi Jia
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Hsiang-Chun Chang
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Matthew J. Schipma
- Next Generation Sequencing Core Facility, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Jing Liu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Varsha Shete
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Ning Liu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Tatsuya Sato
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Edward B. Thorp
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Philip M. Barger
- Center for Cardiovascular Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Yi-Jun Zhu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Navin Viswakarma
- Department of Surgery, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Yashpal S. Kanwar
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Hossein Ardehali
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Bayar Thimmapaya
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail: (JKR); (BT)
| | - Janardan K. Reddy
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail: (JKR); (BT)
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Thomas-Claudepierre AS, Robert I, Rocha PP, Raviram R, Schiavo E, Heyer V, Bonneau R, Luo VM, Reddy JK, Borggrefe T, Skok JA, Reina-San-Martin B. Mediator facilitates transcriptional activation and dynamic long-range contacts at the IgH locus during class switch recombination. J Exp Med 2016; 213:303-12. [PMID: 26903242 PMCID: PMC4813673 DOI: 10.1084/jem.20141967] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 01/15/2016] [Indexed: 12/21/2022] Open
Abstract
Thomas-Claudepierre et al. report that mediator facilitates the long-range contacts between acceptor switch regions and the IgH locus enhancers during class switch recombination and their transcriptional activation. Immunoglobulin (Ig) class switch recombination (CSR) is initiated by the transcription-coupled recruitment of activation-induced cytidine deaminase (AID) to Ig switch regions (S regions). During CSR, the IgH locus undergoes dynamic three-dimensional structural changes in which promoters, enhancers, and S regions are brought to close proximity. Nevertheless, little is known about the underlying mechanisms. In this study, we show that Med1 and Med12, two subunits of the mediator complex implicated in transcription initiation and long-range enhancer/promoter loop formation, are dynamically recruited to the IgH locus enhancers and the acceptor regions during CSR and that their knockdown in CH12 cells results in impaired CSR. Furthermore, we show that conditional inactivation of Med1 in B cells results in defective CSR and reduced acceptor S region transcription. Finally, we show that in B cells undergoing CSR, the dynamic long-range contacts between the IgH enhancers and the acceptor regions correlate with Med1 and Med12 binding and that they happen at a reduced frequency in Med1-deficient B cells. Our results implicate the mediator complex in the mechanism of CSR and are consistent with a model in which mediator facilitates the long-range contacts between S regions and the IgH locus enhancers during CSR and their transcriptional activation.
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Affiliation(s)
- Anne-Sophie Thomas-Claudepierre
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67400 Illkirch, France Institut National de la Santé et de la Recherche Médicale, Unité 964, 67404 Illkirch, France Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, 67404 Illkirch, France Université de Strasbourg, 67400 Illkirch, France
| | - Isabelle Robert
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67400 Illkirch, France Institut National de la Santé et de la Recherche Médicale, Unité 964, 67404 Illkirch, France Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, 67404 Illkirch, France Université de Strasbourg, 67400 Illkirch, France
| | - Pedro P Rocha
- Department of Pathology, School of Medicine, New York University, New York, NY 10003
| | - Ramya Raviram
- Department of Pathology, School of Medicine, New York University, New York, NY 10003 Department of Biology, New York University, New York, NY 10003
| | - Ebe Schiavo
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67400 Illkirch, France Institut National de la Santé et de la Recherche Médicale, Unité 964, 67404 Illkirch, France Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, 67404 Illkirch, France Université de Strasbourg, 67400 Illkirch, France
| | - Vincent Heyer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67400 Illkirch, France Institut National de la Santé et de la Recherche Médicale, Unité 964, 67404 Illkirch, France Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, 67404 Illkirch, France Université de Strasbourg, 67400 Illkirch, France
| | - Richard Bonneau
- Department of Biology, New York University, New York, NY 10003 Department of Computer Science, Courant Institute of Mathematical Sciences, New York, NY 10003 Simons Center for Data Analysis, New York, NY 10010
| | - Vincent M Luo
- Department of Pathology, School of Medicine, New York University, New York, NY 10003 Department of Biology, New York University, New York, NY 10003
| | - Janardan K Reddy
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60208
| | | | - Jane A Skok
- Department of Pathology, School of Medicine, New York University, New York, NY 10003 New York University Cancer Institute, New York University, New York, NY 10003
| | - Bernardo Reina-San-Martin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67400 Illkirch, France Institut National de la Santé et de la Recherche Médicale, Unité 964, 67404 Illkirch, France Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, 67404 Illkirch, France Université de Strasbourg, 67400 Illkirch, France
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27
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Lempradl A, Pospisilik JA, Penninger JM. Exploring the emerging complexity in transcriptional regulation of energy homeostasis. Nat Rev Genet 2015; 16:665-81. [PMID: 26460345 DOI: 10.1038/nrg3941] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Obesity and its associated diseases are expected to affect more than 1 billion people by the year 2030. These figures have sparked intensive research into the molecular control of food intake, nutrient distribution, storage and metabolism--processes that are collectively termed energy homeostasis. Recent decades have also seen dramatic developments in our understanding of gene regulation at the signalling, chromatin and post-transcriptional levels. The seemingly exponential growth in this complexity now poses a major challenge for translational researchers in need of simplified but accurate paradigms for clinical use. In this Review, we consider the current understanding of transcriptional control of energy homeostasis, including both transcriptional and epigenetic regulators, and crosstalk between pathways. We also provide insights into emerging developments and challenges in this field.
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Affiliation(s)
- Adelheid Lempradl
- Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, 79108 Freiburg, Germany
| | - J Andrew Pospisilik
- Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, 79108 Freiburg, Germany
| | - Josef M Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Dr Bohr-Gasse 3, 1030 Vienna, Austria
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28
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Abstract
The ultrastructure of the cardiac myocyte is remarkable for the high density of mitochondria tightly packed between sarcomeres. This structural organization is designed to provide energy in the form of ATP to fuel normal pump function of the heart. A complex system comprised of regulatory factors and energy metabolic machinery, encoded by both mitochondrial and nuclear genomes, is required for the coordinate control of cardiac mitochondrial biogenesis, maturation, and high-capacity function. This process involves the action of a transcriptional regulatory network that builds and maintains the mitochondrial genome and drives the expression of the energy transduction machinery. This finely tuned system is responsive to developmental and physiological cues, as well as changes in fuel substrate availability. Deficiency of components critical for mitochondrial energy production frequently manifests as a cardiomyopathic phenotype, underscoring the requirement to maintain high respiration rates in the heart. Although a precise causative role is not clear, there is increasing evidence that perturbations in this regulatory system occur in the hypertrophied and failing heart. This review summarizes current knowledge and highlights recent advances in our understanding of the transcriptional regulatory factors and signaling networks that serve to regulate mitochondrial biogenesis and function in the mammalian heart.
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Affiliation(s)
- Rick B Vega
- From the Diabetes and Obesity Research Center, Cardiovascular Pathobiology Program, Sanford-Burnham Medical Research Institute, Orlando, FL
| | - Julie L Horton
- From the Diabetes and Obesity Research Center, Cardiovascular Pathobiology Program, Sanford-Burnham Medical Research Institute, Orlando, FL
| | - Daniel P Kelly
- From the Diabetes and Obesity Research Center, Cardiovascular Pathobiology Program, Sanford-Burnham Medical Research Institute, Orlando, FL.
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29
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Huszar JM, Jia Y, Reddy JK, Payne CJ. Med1 regulates meiotic progression during spermatogenesis in mice. Reproduction 2015; 149:597-604. [PMID: 25778538 PMCID: PMC4417004 DOI: 10.1530/rep-14-0483] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 03/16/2015] [Indexed: 12/30/2022]
Abstract
Spermatogenesis is a highly coordinated process. Signaling from nuclear hormone receptors, like those for retinoic acid (RA), is important for normal spermatogenesis. However, the mechanisms regulating these signals are poorly understood. Mediator complex subunit 1 (MED1) is a transcriptional enhancer that directly modulates transcription from nuclear hormone receptors. MED1 is present in male germ cells throughout mammalian development, but its function during spermatogenesis is unknown. To determine its role, we generated mice lacking Med1 specifically in their germ cells beginning just before birth. Conditional Med1 knockout males are fertile, exhibiting normal testis weights and siring ordinary numbers of offspring. RA-responsive gene products stimulated by RA gene 8 (Stra8) and synaptonemal complex protein 3 (Sycp3) are first detected in knockout spermatogonia at the expected time points during the first wave of spermatogenesis, and persist with normal patterns of cellular distribution in adult knockout testes. Meiotic progression, however, is altered in the absence of Med1. At postnatal day 7 (P7), zygotene-stage knockout spermatocytes are already detected, unlike in control testes, with fewer pre-leptotene-stage cells and more leptotene spermatocytes observed in the knockouts. At P9, Med1 knockout spermatocytes prematurely enter pachynema. Once formed, greater numbers of knockout spermatocytes remain in pachynema relative to the other stages of meiosis throughout testis development and its maintenance in the adult. Meiotic exit is not inhibited. We conclude that MED1 regulates the temporal progression of primary spermatocytes through meiosis, with its absence resulting in abbreviated pre-leptotene, leptotene, and zygotene stages, and a prolonged pachytene stage.
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Affiliation(s)
- Jessica M Huszar
- Driskill Graduate ProgramDepartment of PathologyDepartments of Pediatrics and Obstetrics and GynecologyNorthwestern University Feinberg School of Medicine and Human Molecular Genetics Program, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Avenue, PO Box 211, Chicago, Illinois 60611, USA
| | - Yuzhi Jia
- Driskill Graduate ProgramDepartment of PathologyDepartments of Pediatrics and Obstetrics and GynecologyNorthwestern University Feinberg School of Medicine and Human Molecular Genetics Program, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Avenue, PO Box 211, Chicago, Illinois 60611, USA
| | - Janardan K Reddy
- Driskill Graduate ProgramDepartment of PathologyDepartments of Pediatrics and Obstetrics and GynecologyNorthwestern University Feinberg School of Medicine and Human Molecular Genetics Program, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Avenue, PO Box 211, Chicago, Illinois 60611, USA
| | - Christopher J Payne
- Driskill Graduate ProgramDepartment of PathologyDepartments of Pediatrics and Obstetrics and GynecologyNorthwestern University Feinberg School of Medicine and Human Molecular Genetics Program, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Avenue, PO Box 211, Chicago, Illinois 60611, USA Driskill Graduate ProgramDepartment of PathologyDepartments of Pediatrics and Obstetrics and GynecologyNorthwestern University Feinberg School of Medicine and Human Molecular Genetics Program, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Avenue, PO Box 211, Chicago, Illinois 60611, USA
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30
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Gao Q, Jia Y, Yang G, Zhang X, Boddu PC, Petersen B, Narsingam S, Zhu YJ, Thimmapaya B, Kanwar YS, Reddy JK. PPARα-Deficient ob/ob Obese Mice Become More Obese and Manifest Severe Hepatic Steatosis Due to Decreased Fatty Acid Oxidation. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1396-408. [PMID: 25773177 DOI: 10.1016/j.ajpath.2015.01.018] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/05/2015] [Accepted: 01/12/2015] [Indexed: 02/06/2023]
Abstract
Obesity poses an increased risk of developing metabolic syndrome and closely associated nonalcoholic fatty liver disease, including liver cancer. Satiety hormone leptin-deficient (ob/ob) mice, considered paradigmatic of nutritional obesity, develop hepatic steatosis but are less prone to developing liver tumors. Sustained activation of peroxisome proliferator-activated receptor α (PPARα) in ob/ob mouse liver increases fatty acid oxidation (FAO), which contributes to attenuation of obesity but enhances liver cancer risk. To further evaluate the role of PPARα-regulated hepatic FAO and energy burning in the progression of fatty liver disease, we generated PPARα-deficient ob/ob (PPARα(Δ)ob/ob) mice. These mice become strikingly more obese compared to ob/ob littermates, with increased white and brown adipose tissue content and severe hepatic steatosis. Hepatic steatosis becomes more severe in fasted PPARα(Δ)ob/ob mice as they fail to up-regulate FAO systems. PPARα(Δ)ob/ob mice also do not respond to peroxisome proliferative and mitogenic effects of PPARα agonist Wy-14,643. Although PPARα(Δ)ob/ob mice are severely obese, there was no significant increase in liver tumor incidence, even when maintained on a diet containing Wy-14,643. We conclude that sustained PPARα activation-related increase in FAO in fatty livers of obese ob/ob mice increases liver cancer risk, whereas deletion of PPARα in ob/ob mice aggravates obesity and hepatic steatosis. However, it does not lead to liver tumor development because of reduction in FAO and energy burning.
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Affiliation(s)
- Qian Gao
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Laboratory of Animal Fat Deposition and Muscle Development, College of Animal Science and Technology, Northwest A&F University, Shaanxi, China
| | - Yuzhi Jia
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Gongshe Yang
- Laboratory of Animal Fat Deposition and Muscle Development, College of Animal Science and Technology, Northwest A&F University, Shaanxi, China
| | - Xiaohong Zhang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Prajwal C Boddu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Bryon Petersen
- Department of Pediatrics, Child Health Research Institute, College of Medicine, University of Florida, Gainesville, Florida
| | - Saiprasad Narsingam
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Yi-Jun Zhu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Bayar Thimmapaya
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Yashpal S Kanwar
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Janardan K Reddy
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
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31
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Pawlak M, Lefebvre P, Staels B. Molecular mechanism of PPARα action and its impact on lipid metabolism, inflammation and fibrosis in non-alcoholic fatty liver disease. J Hepatol 2015; 62:720-33. [PMID: 25450203 DOI: 10.1016/j.jhep.2014.10.039] [Citation(s) in RCA: 943] [Impact Index Per Article: 104.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 09/22/2014] [Accepted: 10/26/2014] [Indexed: 02/07/2023]
Abstract
Peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor belonging, together with PPARγ and PPARβ/δ, to the NR1C nuclear receptor subfamily. Many PPARα target genes are involved in fatty acid metabolism in tissues with high oxidative rates such as muscle, heart and liver. PPARα activation, in combination with PPARβ/δ agonism, improves steatosis, inflammation and fibrosis in pre-clinical models of non-alcoholic fatty liver disease, identifying a new potential therapeutic area. In this review, we discuss the transcriptional activation and repression mechanisms by PPARα, the spectrum of target genes and chromatin-binding maps from recent genome-wide studies, paying particular attention to PPARα-regulation of hepatic fatty acid and plasma lipoprotein metabolism during nutritional transition, and of the inflammatory response. The role of PPARα, together with other PPARs, in non-alcoholic steatohepatitis will be discussed in light of available pre-clinical and clinical data.
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Affiliation(s)
- Michal Pawlak
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; Université Lille 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; Institut Pasteur de Lille, F-59000 Lille, France
| | - Philippe Lefebvre
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; Université Lille 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; Institut Pasteur de Lille, F-59000 Lille, France
| | - Bart Staels
- European Genomic Institute for Diabetes (EGID), FR 3508, F-59000 Lille, France; Université Lille 2, F-59000 Lille, France; Inserm UMR 1011, F-59000 Lille, France; Institut Pasteur de Lille, F-59000 Lille, France.
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32
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Abstract
Skeletal and cardiac muscles play key roles in the regulation of systemic energy homeostasis and display remarkable plasticity in their metabolic responses to caloric availability and physical activity. In this Perspective we discuss recent studies highlighting transcriptional mechanisms that govern systemic metabolism by striated muscles. We focus on the participation of the Mediator complex in this process, and suggest that tissue-specific regulation of Mediator subunits impacts metabolic homeostasis.
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Affiliation(s)
- Kedryn K Baskin
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA
| | - Benjamin R Winders
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA; Cardiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA
| | - Eric N Olson
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA.
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33
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Transcriptional coregulators: fine-tuning metabolism. Cell Metab 2014; 20:26-40. [PMID: 24794975 PMCID: PMC4079747 DOI: 10.1016/j.cmet.2014.03.027] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 02/28/2014] [Accepted: 03/18/2014] [Indexed: 12/21/2022]
Abstract
Metabolic homeostasis requires that cellular energy levels are adapted to environmental cues. This adaptation is largely regulated at the transcriptional level, through the interaction between transcription factors, coregulators, and the basal transcriptional machinery. Coregulators, which function as both metabolic sensors and transcriptional effectors, are ideally positioned to synchronize metabolic pathways to environmental stimuli. The balance between inhibitory actions of corepressors and stimulatory effects of coactivators enables the fine-tuning of metabolic processes. This tight regulation opens therapeutic opportunities to manage metabolic dysfunction by directing the activity of cofactors toward specific transcription factors, pathways, or cells/tissues, thereby restoring whole-body metabolic homeostasis.
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34
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Ablation of coactivator Med1 switches the cell fate of dental epithelia to that generating hair. PLoS One 2014; 9:e99991. [PMID: 24949995 PMCID: PMC4065011 DOI: 10.1371/journal.pone.0099991] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 05/21/2014] [Indexed: 01/11/2023] Open
Abstract
Cell fates are determined by specific transcriptional programs. Here we provide evidence that the transcriptional coactivator, Mediator 1 (Med1), is essential for the cell fate determination of ectodermal epithelia. Conditional deletion of Med1 in vivo converted dental epithelia into epidermal epithelia, causing defects in enamel organ development while promoting hair formation in the incisors. We identified multiple processes by which hairs are generated in Med1 deficient incisors: 1) dental epithelial stem cells lacking Med 1 fail to commit to the dental lineage, 2) Sox2-expressing stem cells extend into the differentiation zone and remain multi-potent due to reduced Notch1 signaling, and 3) epidermal fate is induced by calcium as demonstrated in dental epithelial cell cultures. These results demonstrate that Med1 is a master regulator in adult stem cells to govern epithelial cell fate.
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35
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Jun HJ, Lee JH, Kim J, Jia Y, Kim KH, Hwang KY, Yun EJ, Do KR, Lee SJ. Linalool is a PPARα ligand that reduces plasma TG levels and rewires the hepatic transcriptome and plasma metabolome. J Lipid Res 2014; 55:1098-110. [PMID: 24752549 DOI: 10.1194/jlr.m045807] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Indexed: 02/03/2023] Open
Abstract
We investigated the hypotriglyceridemic mechanism of action of linalool, an aromatic monoterpene present in teas and fragrant herbs. Reporter gene and time-resolved fluorescence resonance energy transfer assays demonstrated that linalool is a direct ligand of PPARα. Linalool stimulation reduced cellular lipid accumulation regulating PPARα-responsive genes and significantly induced FA oxidation, and its effects were markedly attenuated by silencing PPARα expression. In mice, the oral administration of linalool for 3 weeks reduced plasma TG concentrations in Western-diet-fed C57BL/6J mice (31%, P < 0.05) and human apo E2 mice (50%, P < 0.05) and regulated hepatic PPARα target genes. However, no such effects were seen in PPARα-deficient mice. Transcriptome profiling revealed that linalool stimulation rewired global gene expression in lipid-loaded hepatocytes and that the effects of 1 mM linalool were comparable to those of 0.1 mM fenofibrate. Metabolomic analysis of the mouse plasma revealed that the global metabolite profiles were significantly distinguishable between linalool-fed mice and controls. Notably, the concentrations of saturated FAs were significantly reduced in linalool-fed mice. These findings suggest that the appropriate intake of a natural aromatic compound could exert beneficial metabolic effects by regulating a cellular nutrient sensor.
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Affiliation(s)
- Hee-Jin Jun
- Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Ji Hae Lee
- Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Jiyoung Kim
- Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Yaoyao Jia
- Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Kyoung Heon Kim
- Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Kwang Yeon Hwang
- Department of Biosystems and Biotechnology, Graduate School of Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Eun Ju Yun
- Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Kyoung-Rok Do
- Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Sung-Joon Lee
- Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
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Misra P, Reddy JK. Peroxisome proliferator-activated receptor-α activation and excess energy burning in hepatocarcinogenesis. Biochimie 2014; 98:63-74. [DOI: 10.1016/j.biochi.2013.11.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 11/14/2013] [Indexed: 01/23/2023]
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Jia Y, Viswakarma N, Reddy JK. Med1 subunit of the mediator complex in nuclear receptor-regulated energy metabolism, liver regeneration, and hepatocarcinogenesis. Gene Expr 2014; 16:63-75. [PMID: 24801167 PMCID: PMC4093800 DOI: 10.3727/105221614x13919976902219] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Several nuclear receptors regulate diverse metabolic functions that impact on critical biological processes, such as development, differentiation, cellular regeneration, and neoplastic conversion. In the liver, some members of the nuclear receptor family, such as peroxisome proliferator-activated receptors (PPARs), constitutive androstane receptor (CAR), farnesoid X receptor (FXR), liver X receptor (LXR), pregnane X receptor (PXR), glucocorticoid receptor (GR), and others, regulate energy homeostasis, the formation and excretion of bile acids, and detoxification of xenobiotics. Excess energy burning resulting from increases in fatty acid oxidation systems in liver generates reactive oxygen species, and the resulting oxidative damage influences liver regeneration and liver tumor development. These nuclear receptors are important sensors of exogenous activators as well as receptor-specific endogenous ligands. In this regard, gene knockout mouse models revealed that some lipid-metabolizing enzymes generate PPARα-activating ligands, while others such as ACOX1 (fatty acyl-CoA oxidase1) inactivate these endogenous PPARα activators. In the absence of ACOX1, the unmetabolized ACOX1 substrates cause sustained activation of PPARα, and the resulting increase in energy burning leads to hepatocarcinogenesis. Ligand-activated nuclear receptors recruit the multisubunit Mediator complex for RNA polymerase II-dependent gene transcription. Evidence indicates that the Med1 subunit of the Mediator is essential for PPARα, PPARγ, CAR, and GR signaling in liver. Med1 null hepatocytes fail to respond to PPARα activators in that these cells do not show induction of peroxisome proliferation and increases in fatty acid oxidation enzymes. Med1-deficient hepatocytes show no increase in cell proliferation and do not give rise to liver tumors. Identification of nuclear receptor-specific coactivators and Mediator subunits should further our understanding of the complexities of metabolic diseases associated with increased energy combustion in liver.
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Affiliation(s)
- Yuzhi Jia
- *Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
| | - Navin Viswakarma
- †Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Maywood, IL, USA
| | - Janardan K. Reddy
- *Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
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Yu J, Xiao Y, Liu J, Ji Y, Liu H, Xu J, Jin X, Liu L, Guan MX, Jiang P. Loss of MED1 triggers mitochondrial biogenesis in C2C12 cells. Mitochondrion 2013; 14:18-25. [PMID: 24368311 DOI: 10.1016/j.mito.2013.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Revised: 10/31/2013] [Accepted: 12/12/2013] [Indexed: 01/09/2023]
Abstract
Under stress conditions transcription factors, including their coactivators, play major roles in mitochondrial biogenesis and oxidative phosphorylation. MED1 (Mediator complex subunit 1) functions as a coactivator of several transcription factors and is implicated in adipogenesis of the lipid and glucose metabolism. This suggests that MED1 may play a role in mitochondrial function. In this study, we found that both the mtDNA content and mitochondrial mass were markedly increased and cell proliferation markedly suppressed in MED1-deficient cells. Upon MED1 loss, Nrf1 and its downstream target genes involved in mitochondrial biogenesis (Tfam, Plormt, Tfb1m), were up-regulated as were those genes in the OXPHOS pathway. Moreover, the knockdown of MED1 resulted in significant changes in the profile of mitochondrial respiration, accompanied by a prominent decrease in the generation of ATP. Collectively, these observations strongly suggest that MED1 has an important affect on mitochondrial function. This further elucidates the role of MED1, particularly its role in the energy metabolism.
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Affiliation(s)
- Jialing Yu
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yun Xiao
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Junxia Liu
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yanchun Ji
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Hao Liu
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jing Xu
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaofen Jin
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Li Liu
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Pingping Jiang
- Department of Genetics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
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Kapadia B, Viswakarma N, Parsa KVL, Kain V, Behera S, Suraj SK, Babu PP, Kar A, Panda S, Zhu YJ, Jia Y, Thimmapaya B, Reddy JK, Misra P. ERK2-mediated phosphorylation of transcriptional coactivator binding protein PIMT/NCoA6IP at Ser298 augments hepatic gluconeogenesis. PLoS One 2013; 8:e83787. [PMID: 24358311 PMCID: PMC3866170 DOI: 10.1371/journal.pone.0083787] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 11/08/2013] [Indexed: 12/22/2022] Open
Abstract
PRIP-Interacting protein with methyl transferase domain (PIMT) serves as a molecular bridge between CREB-binding protein (CBP)/ E1A binding protein p300 (Ep300) -anchored histone acetyl transferase and the Mediator complex sub-unit1 (Med1) and modulates nuclear receptor transcription. Here, we report that ERK2 phosphorylates PIMT at Ser(298) and enhances its ability to activate PEPCK promoter. We observed that PIMT is recruited to PEPCK promoter and adenoviral-mediated over-expression of PIMT in rat primary hepatocytes up-regulated expression of gluconeogenic genes including PEPCK. Reporter experiments with phosphomimetic PIMT mutant (PIMT(S298D)) suggested that conformational change may play an important role in PIMT-dependent PEPCK promoter activity. Overexpression of PIMT and Med1 together augmented hepatic glucose output in an additive manner. Importantly, expression of gluconeogenic genes and hepatic glucose output were suppressed in isolated liver specific PIMT knockout mouse hepatocytes. Furthermore, consistent with reporter experiments, PIMT(S298D) but not PIMT(S298A) augmented hepatic glucose output via up-regulating the expression of gluconeogenic genes. Pharmacological blockade of MAPK/ERK pathway using U0126, abolished PIMT/Med1-dependent gluconeogenic program leading to reduced hepatic glucose output. Further, systemic administration of T4 hormone to rats activated ERK1/2 resulting in enhanced PIMT ser(298) phosphorylation. Phosphorylation of PIMT led to its increased binding to the PEPCK promoter, increased PEPCK expression and induction of gluconeogenesis in liver. Thus, ERK2-mediated phosphorylation of PIMT at Ser(298) is essential in hepatic gluconeogenesis, demonstrating an important role of PIMT in the pathogenesis of hyperglycemia.
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Affiliation(s)
- Bandish Kapadia
- Department of Biology, Dr Reddy’s Institute of Life Sciences, An Associate Institute of University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Navin Viswakarma
- Department of Biology, Dr Reddy’s Institute of Life Sciences, An Associate Institute of University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Kishore V. L. Parsa
- Department of Biology, Dr Reddy’s Institute of Life Sciences, An Associate Institute of University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Vasundhara Kain
- Department of Biology, Dr Reddy’s Institute of Life Sciences, An Associate Institute of University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Soma Behera
- Department of Biology, Dr Reddy’s Institute of Life Sciences, An Associate Institute of University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Sashidhara Kaimal Suraj
- Department of Biotechnology, School of Life Sciences, University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Phanithi Prakash Babu
- Department of Biotechnology, School of Life Sciences, University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Anand Kar
- Department of Life Sciences, Devi Ahilya University, Indore, Madhya Pradesh, India
| | - Sunanda Panda
- Department of Life Sciences, Devi Ahilya University, Indore, Madhya Pradesh, India
| | - Yi-jun Zhu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Yuzhi Jia
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Bayar Thimmapaya
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Janardan K. Reddy
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail: (PM); (JKR)
| | - Parimal Misra
- Department of Biology, Dr Reddy’s Institute of Life Sciences, An Associate Institute of University of Hyderabad, Hyderabad, Andhra Pradesh, India
- * E-mail: (PM); (JKR)
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40
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Kim S, Kiyosawa N, Burgoon LD, Chang CC, Zacharewski TR. PPARα-mediated responses in human adult liver stem cells: In vivo/in vitro and cross-species comparisons. J Steroid Biochem Mol Biol 2013; 138:236-47. [PMID: 23811191 DOI: 10.1016/j.jsbmb.2013.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 06/13/2013] [Accepted: 06/15/2013] [Indexed: 01/06/2023]
Abstract
The peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor that regulates a variety of biological processes including lipid metabolism and energy homeostasis. Peroxisome proliferators (PPs) are carcinogens in rodents, while humans are resistant to peroxisome proliferation and carcinogenesis. In this study, we examined the differential gene expression elicited by clofibrate (CLO) and WY-14,643 (WY) in C57BL/6 mouse liver compared to responses in human HepG2 hepatoma and HL1-1 adult stem cells. Mice were gavaged with sesame oil, 300mg/kg CLO or WY for 2, 4, 8, 12, 18 or 24h, or daily for 4 or 14 days. Although no significant changes in body weight gain were observed, WY induced relative liver weight at 4 and 14 days. Genome-wide hepatic gene expression analysis identified 719 and 1443 differentially expressed unique genes elicited by CLO and WY, respectively (|fold change|>1.5, P1(t)>0.99). Functional analysis associated the gene expression changes with lipid metabolism, transport, cell cycle and immune response. Most differentially expressed genes were in common to both treatments and clustered together only at early time points (2-8h). Complementary QRT-PCR studies in human HL1-1 and HepG2 cells treated with 50μM WY or DMSO for 1, 2, 4, 8, 12, 24 or 48h identified a minimal number of conserved orthologous responses (e.g., Pdk4, Adfp and Angptl4) while some genes (i.e., Bmf, a tumor suppressor) exhibited induction in human cells but repression in mice. These data suggest that PPs elicit species-specific PPARα-mediated gene expression.
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Affiliation(s)
- S Kim
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, United States; Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824, United States.
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41
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Vamecq J, Cherkaoui-Malki M, Andreoletti P, Latruffe N. The human peroxisome in health and disease: the story of an oddity becoming a vital organelle. Biochimie 2013; 98:4-15. [PMID: 24075875 DOI: 10.1016/j.biochi.2013.09.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 09/18/2013] [Indexed: 12/18/2022]
Abstract
Since the first report by Rhodin in 1954, our knowledge on mammalian microbodies/peroxisomes has known several periods. An initial two decades period (1954-1973) has contributed to the biochemical individualisation of peroxisomes as a new class of subcellular organelles (de Duve, 1965). The corresponding research period failed to define a clear role of mammalian peroxisomes in vital functions and intermediary metabolism, explaining why feeling that peroxisomes might be in the human cell oddities has prevailed during several decades. The period standing from 1973 to nowadays has progressively removed this cell oddity view of peroxisomes by highlighting vital function and metabolic role of peroxisomes in health and disease along with genetic and metabolic regulation of peroxisomal protein content, organelle envelope formation and protein signal targeting mechanisms. Research on peroxisomes and their response to various drugs and metabolites, dietary and physiological conditions has also played a key role in the discovery of peroxisome proliferator activated receptors (PPARs) belonging to the nuclear hormone receptor superfamily and for which impact in science and medicine goes now by far beyond that of the peroxisomes.
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Affiliation(s)
- Joseph Vamecq
- INSERM, Laboratory of Biochemistry and Molecular Biology, Hormonology-Metabolism-Nutrition-Oncology, Centre of Biology and Pathology (CBP), CHU Lille, France.
| | - Mustapha Cherkaoui-Malki
- Laboratory of Biochemistry of Peroxisome, Inflammation & Lipids Metabolism (BioPeroxIL-EA7270), University of Burgundy, 21000 Dijon, France
| | - Pierre Andreoletti
- Laboratory of Biochemistry of Peroxisome, Inflammation & Lipids Metabolism (BioPeroxIL-EA7270), University of Burgundy, 21000 Dijon, France
| | - Norbert Latruffe
- Laboratory of Biochemistry of Peroxisome, Inflammation & Lipids Metabolism (BioPeroxIL-EA7270), University of Burgundy, 21000 Dijon, France
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Viswakarma N, Jia Y, Bai L, Gao Q, Lin B, Zhang X, Misra P, Rana A, Jain S, Gonzalez FJ, Zhu YJ, Thimmapaya B, Reddy JK. The Med1 subunit of the mediator complex induces liver cell proliferation and is phosphorylated by AMP kinase. J Biol Chem 2013; 288:27898-911. [PMID: 23943624 DOI: 10.1074/jbc.m113.486696] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mediator, a large multisubunit protein complex, plays a pivotal role in gene transcription by linking gene-specific transcription factors with the preinitiation complex and RNA polymerase II. In the liver, the key subunit of the Mediator complex, Med1, interacts with several nuclear receptors and transcription factors to direct gene-specific transcription. Conditional knock-out of Med1 in the liver showed that hepatocytes lacking Med1 did not regenerate following either partial hepatectomy or treatment with certain nuclear receptor activators and failed to give rise to tumors when challenged with carcinogens. We now report that the adenovirally driven overexpression of Med1 in mouse liver stimulates hepatocyte DNA synthesis with enhanced expression of DNA replication, cell cycle control, and liver-specific genes, indicating that Med1 alone is necessary and sufficient for liver cell proliferation. Importantly, we demonstrate that AMP-activated protein kinase (AMPK), an important cellular energy sensor, interacts with, and directly phosphorylates, Med1 in vitro at serine 656, serine 756, and serine 796. AMPK also phosphorylates Med1 in vivo in mouse liver and in cultured primary hepatocytes and HEK293 and HeLa cells. In addition, we demonstrate that PPARα activators increase AMPK-mediated Med1 phosphorylation in vivo. Inhibition of AMPK by compound C decreased hepatocyte proliferation induced by Med1 and also by the PPARα activators fenofibrate and Wy-14,643. Co-treatment with compound C attenuated PPARα activator-inducible fatty acid β-oxidation in liver. Our results suggest that Med1 phosphorylation by its association with AMPK regulates liver cell proliferation and fatty acid oxidation, most likely as a downstream effector of PPARα and AMPK.
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Affiliation(s)
- Navin Viswakarma
- From the Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
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43
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Bywater MJ, Pearson RB, McArthur GA, Hannan RD. Dysregulation of the basal RNA polymerase transcription apparatus in cancer. Nat Rev Cancer 2013; 13:299-314. [PMID: 23612459 DOI: 10.1038/nrc3496] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mutations that directly affect transcription by RNA polymerases rank among the most central mediators of malignant transformation, but the frequency of new anticancer drugs that selectively target defective transcription apparatus entering the clinic has been limited. This is because targeting the large protein-protein and protein-DNA interfaces that control both generic and selective aspects of RNA polymerase transcription has proved extremely difficult. However, recent technological advances have led to a 'quantum leap' in our comprehension of the structure and function of the core RNA polymerase components, how they are dysregulated in a broad range of cancers and how they may be targeted for 'transcription therapy'.
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Affiliation(s)
- Megan J Bywater
- Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne 8006, Victoria, Australia
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Misra P, Viswakarma N, Reddy JK. Peroxisome proliferator-activated receptor-α signaling in hepatocarcinogenesis. Subcell Biochem 2013; 69:77-99. [PMID: 23821144 DOI: 10.1007/978-94-007-6889-5_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Peroxisomes are subcellular organelles that are found in the cytoplasm of most animal cells. They perform diverse metabolic functions, including H2O2-derived respiration, β-oxidation of fatty acids, and cholesterol metabolism. Peroxisome proliferators are a large class of structurally dissimilar industrial and pharmaceutical chemicals that were originally identified as inducers of both the size and the number of peroxisomes in rat and mouse livers or hepatocytes in vitro. Exposure to peroxisome proliferators leads to a stereotypical orchestration of adaptations consisting of hepatocellular hypertrophy and hyperplasia, and transcriptional induction of fatty acid metabolizing enzymes regulated in parallel with peroxisome proliferation. Chronic exposure to peroxisome proliferators causes liver tumors in both male and female mice and rats. Evidence indicates a pivotal role for a subset of nuclear receptor superfamily members, called peroxisome proliferator-activated receptors (PPARs), in mediating energy metabolism. Upon activation, PPARs regulate the expression of genes involved in lipid metabolism and peroxisome proliferation, as well as genes involved in cell growth. In this review, we describe the molecular mode of action of PPAR transcription factors, including ligand binding, interaction with specific DNA response elements, transcriptional activation, and cross talk with other signaling pathways. We discuss the evidence that suggests that PPARα and transcriptional coactivator Med1/PBP, a key subunit of the Mediator complex play a central role in mediating hepatic steatosis to hepatocarcinogenesis. Disproportionate increases in H2O2-generating enzymes generates excess reactive oxygen species resulting in sustained oxidative stress and progressive endoplasmic reticulum (ER) stress with activation of unfolded protein response signaling. Thus, these major contributors coupled with hepatocellular proliferation are the key players of peroxisome proliferators-induced hepatocarcinogenesis.
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Affiliation(s)
- Parimal Misra
- Department of Biology, Dr. Reddy's Institute of Life Sciences, An Associate Institute of University of Hyderabad, Gachibowli, Hyderabad, 500046, India,
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45
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Jia Y, Viswakarma N, Crawford SE, Sarkar J, Sambasiva Rao M, Karpus WJ, Kanwar YS, Zhu YJ, Reddy JK. Early embryonic lethality of mice with disrupted transcription cofactor PIMT/NCOA6IP/Tgs1 gene. Mech Dev 2012; 129:193-207. [PMID: 22982455 DOI: 10.1016/j.mod.2012.08.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Revised: 08/09/2012] [Accepted: 08/27/2012] [Indexed: 11/29/2022]
Abstract
PIMT (also known as PIPMT/NCOA6IP/Tgs1), first isolated as a transcription coactivator PRIP (NCOA6)-interacting 96-kDa protein with RNA-binding property, possesses RNA methyltransferase activity. As a transcription coactivator binding protein, PIMT enhances the nuclear receptor transcriptional activity and its methyltransferase property is involved in the formation of the 2,2,7-trimethylguanosine cap of non-coding small RNAs, but the in vivo functions of this gene have not been fully explored. To elucidate the biological functions, we used gene targeting to generate mice with a disrupted PIMT/Tgs1 gene. Disruption of PIMT gene results in early embryonic lethality due to impairment of development around the blastocyst and uterine implantation stages. We show that PIMT is expressed in all cells of the E3.5day blastocyst in the mouse. PIMT null mutation abolished PIMT expression in all cells of the blastocyst and caused a reduction in the expression of Oct4 and Nanog transcription factor proteins in the E3.5 blastocyst resulting in the near failure to form inner cell mass (ICM). With conditional deletion of PIMT gene, mouse embryonic fibroblasts (MEFs) exhibit defective wound healing in the scratch assay and a reduction in cell proliferation due to decreased G₀/G₁ transition and G₂/M phase cell cycle arrest. We conclude that PIMT/NCOA6IP, which is expressed in all cells of the 3.5 day stage blastocyst, is indispensable for early embryonic development.
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Affiliation(s)
- Yuzhi Jia
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611-3008, USA
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46
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Roles of MED1 in quiescence of hair follicle stem cells and maintenance of normal hair cycling. J Invest Dermatol 2012; 133:354-60. [PMID: 22931914 DOI: 10.1038/jid.2012.293] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
MED1 (mediator complex subunit 1) is expressed by human epidermal keratinocytes and functions as a coactivator of several transcription factors. To elucidate the role of MED1 in keratinocytes, we established keratinocyte-specific Med1-null (Med1(epi-/-)) mice using the K5Cre/LoxP system. Development of the epidermis and appendages of Med1(epi-/-) mice were macroscopically and microscopically normal until the second catagen of the hair cycle. However, the hair cycle of Med1(epi-/-) mice was spontaneously repeated after the second telogen, which does not occur in wild-type (WT) mice. Hair follicles of Med1(epi-/-) mice could not enter anagen after 6 months of age, resulting in sparse pelage hair in older Med1(epi-/-) mice. Interfollicular epidermis (IFE) of Med1(epi-/-) mice was acanthotic and more proliferative than that of WT mice, whereas these findings were less evident in older Med1(epi-/-) mice. Flow cytometric analysis revealed that the numbers of hair follicle bulge stem cells were reduced in Med1(epi-/-) mice from a few months after birth. These results suggest that MED1 has roles in maintaining quiescence of keratinocytes and preventing depletion of the follicular stem cells.
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47
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Oda Y, Hu L, Bul V, Elalieh H, Reddy JK, Bikle DD. Coactivator MED1 ablation in keratinocytes results in hair-cycling defects and epidermal alterations. J Invest Dermatol 2011; 132:1075-83. [PMID: 22189783 PMCID: PMC3400544 DOI: 10.1038/jid.2011.430] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The transcriptional coactivator complex Mediator facilitates transcription of nuclear hormone receptors and other transcription factors. We have previously isolated the Mediator complex from primary keratinocytes as the vitamin D receptor interacting protein complex. We identified a role for Mediator in keratinocyte proliferation and differentiation in cultured keratinocytes. Here, we investigated the in vivo role of Mediator by generating conditional null mice, where a critical subunit of the Mediator complex, MED1, is deleted from their keratinocytes. The MED1 ablation resulted in aberrant hair differentiation and cycling leading to hair loss. During the first hair follicle cycle, MED1 deletion resulted in a rapid regression of the hair follicles. Hair differentiation was reduced, and β-catenin/vitamin D receptor (VDR) regulated gene expression was dramatically decreased. In the subsequent adult hair cycle, MED1 ablation activated the initiation of hair follicle cycling. Shh signaling was increased, but terminal differentiation was not sufficient. Deletion of MED1 also caused hyper-proliferation of interfollicular epidermal keratinocytes, and increased the expression of epidermal differentiation markers. These results indicate that MED1 plays a critical role in regulating hair/epidermal proliferation and differentiation.
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Affiliation(s)
- Yuko Oda
- Department of Medicine and Endocrinology, University of California, San Francisco and Veterans Affairs Medical Center San Francisco, San Francisco, California 94121, USA.
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48
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Lethal mitochondrial cardiomyopathy in a hypomorphic Med30 mouse mutant is ameliorated by ketogenic diet. Proc Natl Acad Sci U S A 2011; 108:19678-82. [PMID: 22106289 DOI: 10.1073/pnas.1117835108] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Deficiencies of subunits of the transcriptional regulatory complex Mediator generally result in embryonic lethality, precluding study of its physiological function. Here we describe a missense mutation in Med30 causing progressive cardiomyopathy in homozygous mice that, although viable during lactation, show precipitous lethality 2-3 wk after weaning. Expression profiling reveals pleiotropic changes in transcription of cardiac genes required for oxidative phosphorylation and mitochondrial integrity. Weaning mice to a ketogenic diet extends viability to 8.5 wk. Thus, we establish a mechanistic connection between Mediator and induction of a metabolic program for oxidative phosphorylation and fatty acid oxidation, in which lethal cardiomyopathy is mitigated by dietary intervention.
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Huang J, Jia Y, Fu T, Viswakarma N, Bai L, Rao MS, Zhu Y, Borensztajn J, Reddy JK. Sustained activation of PPARα by endogenous ligands increases hepatic fatty acid oxidation and prevents obesity in ob/ob mice. FASEB J 2011; 26:628-38. [PMID: 22009939 DOI: 10.1096/fj.11-194019] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Obesity, a major health concern, results from an imbalance between energy intake and expenditure. Leptin-deficient ob/ob mice are paradigmatic of obesity, resulting from excess energy intake and storage. Mice lacking acyl-CoA oxidase 1 (Acox1), the first enzyme of the peroxisomal fatty acid β-oxidation system, are characterized by increased energy expenditure and a lean body phenotype caused by sustained activation of peroxisome proliferator-activated receptor α (PPARα) by endogenous ligands in liver that remain unmetabolized in the absence of Acox1. We generated ob/ob mice deficient in Acox1 (Acox1(-/-)) to determine how the activation of PPARα by endogenous ligands might affect the obesity of ob/ob mice. In contrast to Acox1(-/-) (14.3±1.2 g at 6 mo) and the Acox1-deficient (ob/ob) double-mutant mice (23.8±4.6 g at 6 mo), the ob/ob mice are severely obese (54.3±3.2 g at 6 mo) and had significantly more (P<0.01) epididymal fat content. The resistance of Acox1(-/-)/ob/ob mice to obesity is due to increased PPARα-mediated up-regulation of genes involved in fatty acid oxidation in liver. Activation of PPARα in Acox1-deficient ob/ob mice also reduces serum glucose and insulin (P<0.05) and improves glucose tolerance and insulin sensitivity. Further, PPARα activation reduces hepatic steatosis and increases hepatocellular regenerative response in Acox1(-/-)/ob/ob mice at a more accelerated pace than in mice lacking only Acox1. However, Acox1(-/-)/ob/ob mice manifest hepatic endoplasmic reticulum (ER) stress and also develop hepatocellular carcinomas (8 of 8 mice) similar to those observed in Acox1(-/-) mice (10 of 10 mice), but unlike in ob/ob (0 of 14 mice) and OB/OB (0 of 6 mice) mice, suggesting that superimposed ER stress and PPARα activation contribute to carcinogenesis in a fatty liver. Finally, absence of Acox1 in ob/ob mice can impart resistance to high-fat diet (60% fat)-induced obesity, and their liver had significantly (P<0.01) more cell proliferation. These studies with Acox1(-/-)/ob/ob mice indicate that sustained activation of lipid-sensing nuclear receptor PPARα attenuates obesity and restores glucose homeostasis by ameliorating insulin resistance but increases the risk for liver cancer development, in part related to excess energy combustion.
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Affiliation(s)
- Jiansheng Huang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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50
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Unraveling framework of the ancestral Mediator complex in human diseases. Biochimie 2011; 94:579-87. [PMID: 21983542 DOI: 10.1016/j.biochi.2011.09.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 09/15/2011] [Indexed: 01/13/2023]
Abstract
Mediator (MED) is a fundamental component of the RNA polymerase II-mediated transcription machinery. This multiprotein complex plays a pivotal role in the regulation of eukaryotic mRNA synthesis. The yeast Mediator complex consists of 26 different subunits. Recent studies indicate additional pathogenic roles for Mediator, for example during transcription elongation and non-coding RNA production. Mediator subunits have been emerging also to have pathophysiological roles suggesting MED-dependent therapeutic targets involving in several diseases, such as cancer, cardiovascular disease (CVD), metabolic and neurological disorders.
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