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Yang Y, Cheng X, Tian W, Zhou B, Wu X, Xu H, Fang F, Fang M, Xu Y. MRTF-A steers an epigenetic complex to activate endothelin-induced pro-inflammatory transcription in vascular smooth muscle cells. Nucleic Acids Res 2014; 42:10460-72. [PMID: 25159611 PMCID: PMC4176337 DOI: 10.1093/nar/gku776] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Endothelin (ET-1) was initially identified as a potent vasoconstrictor contributing to the maintenance of vascular rhythm. Later studies have implicated ET-1, when aberrantly up-regulated within the vasculature, in a range of human pathologies associated with disruption of vascular homeostasis. ET-1 has been shown to invoke strong pro-inflammatory response in vascular smooth muscle cells (VSMCs); the underlying mechanism, however, remains elusive. Here, we report that the transcriptional modulator MRTF-A mediates the activation of pro-inflammatory mediators by ET-1 in VSMCs. ET-1 increased nuclear enrichment and activity of MRTF-A in cultured VSMCs. MRTF-A silencing attenuated ET-1 induced synthesis and release of pro-inflammatory mediators including IL-6, MCP-1 and IL-1 likely as a result of diminished NF-κB activity. In addition, MRTF-A was indispensible for the accumulation of active histone modifications on the gene promoters. Of intrigue, MRTF-A interacted with and recruited ASH2, a component of the mammalian histone methyltransferase complex, to transactivate pro-inflammatory genes in response to ET-1 treatment. The chromatin remodeling proteins BRG1 and BRM were also required for ET-1-dependent induction of pro-inflammatory mediators by communicating with ASH2, a process dependent on MRTF-A. In conclusion, our data have identified a novel epigenetic complex responsible for vascular inflammation inflicted by ET-1.
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Affiliation(s)
- Yuyu Yang
- Key Laboratory of Cardiovascular Disease, Department of Pathophysiology and Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 210029, China Department of Nursing, Jiangsu Jiankang Vocational University, Nanjing, Jiangsu 210029, China
| | - Xian Cheng
- Key Laboratory of Cardiovascular Disease, Department of Pathophysiology and Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Wenfang Tian
- Key Laboratory of Cardiovascular Disease, Department of Pathophysiology and Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Bisheng Zhou
- Key Laboratory of Cardiovascular Disease, Department of Pathophysiology and Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xiaoyan Wu
- Key Laboratory of Cardiovascular Disease, Department of Pathophysiology and Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Huihui Xu
- Key Laboratory of Cardiovascular Disease, Department of Pathophysiology and Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Fei Fang
- Key Laboratory of Cardiovascular Disease, Department of Pathophysiology and Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Mingming Fang
- Key Laboratory of Cardiovascular Disease, Department of Pathophysiology and Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 210029, China State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, China
| | - Yong Xu
- Key Laboratory of Cardiovascular Disease, Department of Pathophysiology and Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 210029, China
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Kasioulis I, Syred HM, Tate P, Finch A, Shaw J, Seawright A, Fuszard M, Botting CH, Shirran S, Adams IR, Jackson IJ, van Heyningen V, Yeyati PL. Kdm3a lysine demethylase is an Hsp90 client required for cytoskeletal rearrangements during spermatogenesis. Mol Biol Cell 2014; 25:1216-33. [PMID: 24554764 PMCID: PMC3982988 DOI: 10.1091/mbc.e13-08-0471] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 02/06/2014] [Accepted: 02/10/2014] [Indexed: 11/30/2022] Open
Abstract
The lysine demethylase Kdm3a (Jhdm2a, Jmjd1a) is required for male fertility, sex determination, and metabolic homeostasis through its nuclear role in chromatin remodeling. Many histone-modifying enzymes have additional nonhistone substrates, as well as nonenzymatic functions, contributing to the full spectrum of events underlying their biological roles. We present two Kdm3a mouse models that exhibit cytoplasmic defects that may account in part for the globozoospermia phenotype reported previously. Electron microscopy revealed abnormal acrosome and manchette and the absence of implantation fossa at the caudal end of the nucleus in mice without Kdm3a demethylase activity, which affected cytoplasmic structures required to elongate the sperm head. We describe an enzymatically active new Kdm3a isoform and show that subcellular distribution, protein levels, and lysine demethylation activity of Kdm3a depended on Hsp90. We show that Kdm3a localizes to cytoplasmic structures of maturing spermatids affected in Kdm3a mutant mice, which in turn display altered fractionation of β-actin and γ-tubulin. Kdm3a is therefore a multifunctional Hsp90 client protein that participates directly in the regulation of cytoskeletal components.
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Affiliation(s)
- Ioannis Kasioulis
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Heather M. Syred
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Peri Tate
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1HH, United Kingdom
| | - Andrew Finch
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Joseph Shaw
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Anne Seawright
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Matt Fuszard
- Biomedical Sciences Research Complex Mass Spectrometry and Proteomics Facility, University of St. Andrews, St. Andrews, Fife KY16 9ST, United Kingdom
| | - Catherine H. Botting
- Biomedical Sciences Research Complex Mass Spectrometry and Proteomics Facility, University of St. Andrews, St. Andrews, Fife KY16 9ST, United Kingdom
| | - Sally Shirran
- Biomedical Sciences Research Complex Mass Spectrometry and Proteomics Facility, University of St. Andrews, St. Andrews, Fife KY16 9ST, United Kingdom
| | - Ian R. Adams
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Ian J. Jackson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Veronica van Heyningen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Patricia L. Yeyati
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
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Xiao Y, Christou H, Liu L, Visner G, Mitsialis SA, Kourembanas S, Liu H. Endothelial indoleamine 2,3-dioxygenase protects against development of pulmonary hypertension. Am J Respir Crit Care Med 2014; 188:482-91. [PMID: 23822766 DOI: 10.1164/rccm.201304-0700oc] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
RATIONALE A proliferative and apoptosis-resistant phenotype in pulmonary arterial smooth muscle cells (PASMCs) is key to pathologic vascular remodeling in pulmonary hypertension (PH). Expression of indoleamine-2,3-dioxygenase (IDO) by vascular endothelium is a newly identified vasomotor-regulatory mechanism also involved in molecular signaling cascades governing vascular smooth muscle cell (vSMC) plasticity. OBJECTIVES To investigate the therapeutic potential of enhanced endothelial IDO in development of PH and its associated vascular remodeling. METHODS We used loss and gain of function in vivo studies to establish the role and determine the therapeutic effect of endothelial IDO in hypoxia-induced PH in mice and monocrotaline-induced PH in rats. We also studied PASMC phenotype in an IDO-high in vivo and in vitro tissue microenvironment. MEASUREMENTS AND MAIN RESULTS The endothelium was the primary site for endogenous IDO production within mouse lung, and the mice lacking this gene had exaggerated hypoxia-induced PH. Conversely, augmented pulmonary endothelial IDO expression, through a human IDO-encoding Sleeping Beauty (SB)-based nonviral gene-integrating approach, halted and attenuated the development of PH, right ventricular hypertrophy, and vascular remodeling in both preclinical models of PH. IDO derived from endothelial cells promoted apoptosis in PH-PASMCs through depolarization of mitochondrial transmembrane potential and down-regulated PH-PASMC proliferative/synthetic capacity through enhanced binding of myocardin to CArG box DNA sequences present within the promoters of vSMC differentiation-specific genes. CONCLUSIONS Enhanced endothelial IDO ameliorates PH and its associated vascular structural remodeling through paracrine phenotypic modulation of PH-PASMCs toward a proapoptotic and less proliferative/synthetic state.
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Affiliation(s)
- Yongguang Xiao
- Department of Surgery, Boston Children’s Hospital, Boston, MA, USA
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54
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Zheng XL. Myocardin and smooth muscle differentiation. Arch Biochem Biophys 2014; 543:48-56. [DOI: 10.1016/j.abb.2013.12.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 12/15/2013] [Accepted: 12/18/2013] [Indexed: 01/08/2023]
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Yu L, Weng X, Liang P, Dai X, Wu X, Xu H, Fang M, Fang F, Xu Y. MRTF-A mediates LPS-induced pro-inflammatory transcription by interacting with the COMPASS complex. J Cell Sci 2014; 127:4645-57. [DOI: 10.1242/jcs.152314] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Chronic inflammation underscores the pathogenesis of a range of human diseases. Lipopolysaccharide (LPS) elicits strong pro-inflammatory response in macrophages via the transcription factor NF-κB. The epigenetic mechanism underlying LPS-induced pro-inflammatory transcription is not completely appreciated. Herein we describe a role for myocardin related transcription factor A, or MRTF-A, in this process. MRTF-A over-expression potentiated while MRTF-A silencing dampened NF-κB dependent pro-inflammatory transcription. MRTF-A deficiency also alleviated the synthesis of pro-inflammatory mediators in a mouse model of colitis. LPS promoted the recruitment of MRTF-A to the promoters of pro-inflammatory genes in a NF-κB dependent manner. Reciprocally, MRTF-A influenced the nuclear enrichment and target binding of NF-κB. Mechanistically, MRTF-A was necessary for the accumulation of active histone modifications on NF-κB target promoters by communicating with the histone H3K4 methyltransferase complex (COMPASS). Silencing of individual members of COMPASS, including ASH2, WDR5, and SET1, down-regulated the production of pro-inflammatory mediators and impaired the NF-κB kinetics. In summary, our work has uncovered a previously unknown function for MRTF-A and provided insights into the rationalized development of anti-inflammatory therapeutic strategies.
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56
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Martin-Garrido A, Williams HC, Lee M, Seidel-Rogol B, Ci X, Dong JT, Lassègue B, Martín AS, Griendling KK. Transforming growth factor β inhibits platelet derived growth factor-induced vascular smooth muscle cell proliferation via Akt-independent, Smad-mediated cyclin D1 downregulation. PLoS One 2013; 8:e79657. [PMID: 24236150 PMCID: PMC3827379 DOI: 10.1371/journal.pone.0079657] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 10/04/2013] [Indexed: 11/18/2022] Open
Abstract
In adult tissue, vascular smooth muscle cells (VSMCs) exist in a differentiated phenotype, which is defined by the expression of contractile proteins and lack of proliferation. After vascular injury, VSMC adopt a synthetic phenotype associated with proliferation, migration and matrix secretion. The transition between phenotypes is a consequence of the extracellular environment, and in particular, is regulated by agonists such as the pro-differentiating cytokine transforming growth factor β (TGFβ) and the pro-proliferative cytokine platelet derived growth factor (PDGF). In this study, we investigated the interplay between TGFβ and PDGF with respect to their ability to regulate VSMC proliferation. Stimulation of human aortic VSMC with TGFβ completely blocked proliferation induced by all isoforms of PDGF, as measured by DNA synthesis and total cell number. Mechanistically, PDGF-induced Cyclin D1 mRNA and protein expression was inhibited by TGFβ. TGFβ had no effect on PDGF activation of its receptor and ERK1/2, but inhibited Akt activation. However, constitutively active Akt did not reverse the inhibitory effect of TGFβ on Cyclin D1 expression even though inhibition of the proteasome blocked the effect of TGFβ. siRNA against Smad4 completely reversed the inhibitory effect of TGFβ on PDGF-induced Cyclin D1 expression and restored proliferation in response to PDGF. Moreover, siRNA against KLF5 prevented Cyclin D1 upregulation by PDGF and overexpression of KLF5 partially reversed TGFβ-induced inhibition of Cyclin D1 expression. Taken together, our results demonstrate that KLF5 is required for PDGF-induced Cyclin D1 expression, which is inhibited by TGFβ via a Smad dependent mechanism, resulting in arrest of VSMCs in the G1 phase of the cell cycle.
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Affiliation(s)
- Abel Martin-Garrido
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia, United States of America
| | - Holly C. Williams
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia, United States of America
| | - Minyoung Lee
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia, United States of America
| | - Bonnie Seidel-Rogol
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia, United States of America
| | - Xinpei Ci
- Winship Cancer Institute, Department of Hematology and Medical Oncology, Emory University, Atlanta, Georgia, United States of America
| | - Jin-Tang Dong
- Winship Cancer Institute, Department of Hematology and Medical Oncology, Emory University, Atlanta, Georgia, United States of America
| | - Bernard Lassègue
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia, United States of America
| | - Alejandra San Martín
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia, United States of America
| | - Kathy K. Griendling
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
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Abstract
Epigenetics involve heritable and acquired changes in gene transcription that occur independently of the DNA sequence. Epigenetic mechanisms constitute a hierarchic upper-level of transcriptional control through complex modifications of chromosomal components and nuclear structures. These modifications include, for example, DNA methylation or post-translational modifications of core histones; they are mediated by various chromatin-modifying enzymes; and ultimately they define the accessibility of a transcriptional complex to its target DNA. Integrating epigenetic mechanisms into the pathophysiologic concept of complex and multifactorial diseases such as atherosclerosis may significantly enhance our understanding of related mechanisms and provide promising therapeutic approaches. Although still in its infancy, intriguing scientific progress has begun to elucidate the role of epigenetic mechanisms in vascular biology, particularly in the control of smooth muscle cell phenotypes. In this review, we will summarize epigenetic pathways in smooth muscle cells, focusing on mechanisms involved in the regulation of vascular remodeling.
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Xu Y. Transcriptional regulation of endothelial dysfunction in atherosclerosis: an epigenetic perspective. J Biomed Res 2013; 28:47-52. [PMID: 24474963 PMCID: PMC3904174 DOI: 10.7555/jbr.27.20130055] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 05/08/2013] [Indexed: 01/07/2023] Open
Abstract
Atherosclerosis is a progressive human pathology that encompasses several stages of development. Endothelial dysfunction represents an early sign of lesion within the vasculature. A number of risk factors for atherosclerosis, including hyperlipidemia, diabetes, and hypertension, target the vascular endothelium by re-programming its transcriptome. These profound alterations taking place on the chromatin rely on the interplay between sequence specific transcription factors and the epigenetic machinery. The epigenetic machinery, in turn, tailor individual transcription events key to atherogenesis to intrinsic and extrinsic insults dictating the development of atherosclerotic lesions. This review summarizes our current understanding of the involvement of the epigenetic machinery in endothelial injury during atherogenesis.
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Affiliation(s)
- Yong Xu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
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59
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Okuno Y, Ohtake F, Igarashi K, Kanno J, Matsumoto T, Takada I, Kato S, Imai Y. Epigenetic regulation of adipogenesis by PHF2 histone demethylase. Diabetes 2013; 62:1426-34. [PMID: 23274892 PMCID: PMC3636657 DOI: 10.2337/db12-0628] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
PHF2 is a JmjC family histone demethylase that removes the methyl group from H3K9me2 and works as a coactivator for several metabolism-related transcription factors. In this study, we examined the in vivo role of PHF2 in mice. We generated Phf2 floxed mice, systemic Phf2 null mice by crossing Phf2 floxed mice with CMV-Cre transgenic mice, and tamoxifen-inducible Phf2 knockout mice by crossing Phf2 floxed mice with Cre-ERT2 transgenic mice. Systemic Phf2 null mice had partial neonatal death and growth retardation and exhibited less adipose tissue and reduced adipocyte numbers compared with control littermates. Tamoxifen-induced conditional knockout of PHF2 resulted in impaired adipogenesis in stromal vascular cells from the adipose tissue of tamoxifen-inducible Phf2 knockout mice as well as of Phf2 knocked-down 3T3-L1 cells. PHF2 interacts with CEBPA and demethylates H3K9me2 in the promoters of CEBPA-regulated adipogenic genes. These findings suggest that PHF2 histone demethylase potentiates adipogenesis through interaction with CEBPA in vivo. Taken together, PHF2 may be a novel therapeutic target in the treatment of obesity and the metabolic syndrome.
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MESH Headings
- 3T3-L1 Cells
- Adipogenesis
- Adipose Tissue, White/enzymology
- Adipose Tissue, White/growth & development
- Adipose Tissue, White/metabolism
- Animals
- CCAAT-Enhancer-Binding Proteins/genetics
- CCAAT-Enhancer-Binding Proteins/metabolism
- Crosses, Genetic
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Epigenesis, Genetic
- Female
- Gene Expression Regulation, Developmental
- Histone Demethylases/genetics
- Histone Demethylases/metabolism
- Histones/metabolism
- Humans
- Male
- Methylation
- Mice
- Mice, Knockout
- Mice, Transgenic
- Promoter Regions, Genetic
- Protein Processing, Post-Translational
- Recombinant Proteins/metabolism
- Weight Gain
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Affiliation(s)
- Yosuke Okuno
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Fumiaki Ohtake
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Katsuhide Igarashi
- Division of Cellular and Molecular Toxicology, National Institute of Health Sciences, Tokyo, Japan
| | - Jun Kanno
- Division of Cellular and Molecular Toxicology, National Institute of Health Sciences, Tokyo, Japan
| | - Takahiro Matsumoto
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Ichiro Takada
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | | | - Yuuki Imai
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
- Corresponding author: Yuuki Imai,
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Yang Y, Chen D, Yuan Z, Fang F, Cheng X, Xia J, Fang M, Xu Y, Gao Y. Megakaryocytic leukemia 1 (MKL1) ties the epigenetic machinery to hypoxia-induced transactivation of endothelin-1. Nucleic Acids Res 2013; 41:6005-17. [PMID: 23625963 PMCID: PMC3695508 DOI: 10.1093/nar/gkt311] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Increased synthesis of endothelin-1 (ET-1) by human vascular endothelial cells (HVECs) in response to hypoxia underscores persistent vasoconstriction observed in patients with pulmonary hypertension. The molecular mechanism whereby hypoxia stimulates ET-1 gene transcription is not well understood. Here we report that megakaryocytic leukemia 1 (MKL1) potentiated hypoxia-induced ET-1 transactivation in HVECs. Disruption of MKL1 activity by either a dominant negative mutant or small interfering RNA mediated knockdown dampened ET-1 synthesis. MKL1 was recruited to the proximal ET-1 promoter region (−81/+150) in HVECs challenged with hypoxic stress by the sequence-specific transcription factor serum response factor (SRF). Depletion of SRF blocked MKL1 recruitment and blunted ET-1 transactivation by hypoxia. Chromatin immunoprecipitation analysis of the ET-1 promoter revealed that MKL1 loss-of-function erased histone modifications consistent with transcriptional activation. In addition, MKL1 was indispensable for the occupancy of Brg1 and Brm, key components of the chromatin remodeling complex, on the ET-1 promoter. Brg1 and Brm modulated ET-1 transactivation by impacting histone modifications. In conclusion, our data have delineated a MKL1-centered complex that links epigenetic maneuverings to ET-1 transactivation in HVECs under hypoxic conditions.
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Affiliation(s)
- Yuyu Yang
- Key Laboratory of Cardiovascular Disease, Nanjing Medical University, Nanjing, Jiangsu 210029, China
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Hohl M, Wagner M, Reil JC, Müller SA, Tauchnitz M, Zimmer AM, Lehmann LH, Thiel G, Böhm M, Backs J, Maack C. HDAC4 controls histone methylation in response to elevated cardiac load. J Clin Invest 2013; 123:1359-70. [PMID: 23434587 DOI: 10.1172/jci61084] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 01/03/2013] [Indexed: 12/28/2022] Open
Abstract
In patients with heart failure, reactivation of a fetal gene program, including atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), is a hallmark for maladaptive remodeling of the LV. The mechanisms that regulate this reactivation are incompletely understood. Histone acetylation and methylation affect the conformation of chromatin, which in turn governs the accessibility of DNA for transcription factors. Using human LV myocardium, we found that, despite nuclear export of histone deacetylase 4 (HDAC4), upregulation of ANP and BNP in failing hearts did not require increased histone acetylation in the promoter regions of these genes. In contrast, di- and trimethylation of lysine 9 of histone 3 (H3K9) and binding of heterochromatin protein 1 (HP1) in the promoter regions of these genes were substantially reduced. In isolated working murine hearts, an acute increase of cardiac preload induced HDAC4 nuclear export, H3K9 demethylation, HP1 dissociation from the promoter region, and activation of the ANP gene. These processes were reversed in hearts with myocyte-specific deletion of Hdac4. We conclude that HDAC4 plays a central role for rapid modifications of histone methylation in response to variations in cardiac load and may represent a target for pharmacological interventions to prevent maladaptive remodeling in patients with heart failure.
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Affiliation(s)
- Mathias Hohl
- Klinik für Innere Medizin III, Universitätsklinikum des Saarlandes, Homburg, Germany
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Bai X, Lenhart KC, Bird KE, Suen AA, Rojas M, Kakoki M, Li F, Smithies O, Mack CP, Taylor JM. The smooth muscle-selective RhoGAP GRAF3 is a critical regulator of vascular tone and hypertension. Nat Commun 2013; 4:2910. [PMID: 24335996 PMCID: PMC4237314 DOI: 10.1038/ncomms3910] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Accepted: 11/11/2013] [Indexed: 12/13/2022] Open
Abstract
Although hypertension is a worldwide health issue, an incomplete understanding of its aetiology has hindered our ability to treat this complex disease. Here we identify arhgap42 (also known as GRAF3) as a Rho-specific GAP expressed specifically in smooth muscle cells (SMCs) in mice and humans. We show that GRAF3-deficient mice exhibit significant hypertension and increased pressor responses to angiotensin II and endothelin-1; these effects are prevented by treatment with the Rho-kinase inhibitor, Y27632. RhoA activity and myosin light chain phosphorylation are elevated in GRAF3-depleted SMCs in vitro and in vivo, and isolated vessel segments from GRAF3-deficient mice show increased contractility. Taken together, our data indicate that GRAF3-mediated inhibition of RhoA activity in vascular SMCs is necessary for maintaining normal blood pressure homoeostasis. Moreover, these findings provide a potential mechanism for a hypertensive locus recently identified within arhgap42 and provide a foundation for the future development of innovative hypertension therapies.
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Affiliation(s)
- Xue Bai
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kaitlin C. Lenhart
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kim E. Bird
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Alisa A. Suen
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Mauricio Rojas
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Masao Kakoki
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Feng Li
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Oliver Smithies
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599, USA
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Christopher P. Mack
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599, USA
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Joan M. Taylor
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599, USA
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA
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Chen WP, Wu SM. Small molecule regulators of postnatal Nkx2.5 cardiomyoblast proliferation and differentiation. J Cell Mol Med 2012; 16:961-5. [PMID: 22212626 PMCID: PMC3325363 DOI: 10.1111/j.1582-4934.2011.01513.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
While recent data have supported the capacity for a neonatal heart to undergo cardiomyogenesis, it is unclear whether these new cardiomyocytes arise from an immature cardiomyoblast population or from the division of mature cardiomyocytes. By following the expression of enhanced Green Fluorescent Protein (eGFP) in an Nkx2.5 enhancer-eGFP transgenic mice, we have identified a population of immature cells that can undergo cardiomyogenic as well as smooth muscle cell differentiation in the neonatal heart. Here, we examined growth factors and small molecule regulators that potentially regulate the proliferation and cardiomyogenic versus smooth muscle cell differentiation of neonatal Nkx2.5-GFP+ cells in vitro. We found that A83-01 (A83), an inhibitor of TGF-βRI, was able to induce an expansion of neonatal Nkx2.5-eGFP+ cells. In addition, the ability of A83 to expand eGFP+ cells in culture was dependent on signalling from the mitogen-activated protein kinase kinase (MEK) as treatment with a MEK inhibitor, PD0325901, abolished this effect. On the other hand, activation of neonatal Nkx2.5-eGFP+ cells with TGF-β1, but not activin A nor BMP2, led to smooth muscle cell differentiation, an effect that can be reversed by treatment with A83. In summary, small molecule inhibition of TGF-β signalling may be a promising strategy to induce the expansion of a rare population of postnatal cardiomyoblasts.
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Affiliation(s)
- Wen-Pin Chen
- Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
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Raphel L, Talasila A, Cheung C, Sinha S. Myocardin overexpression is sufficient for promoting the development of a mature smooth muscle cell-like phenotype from human embryonic stem cells. PLoS One 2012; 7:e44052. [PMID: 22937150 PMCID: PMC3429416 DOI: 10.1371/journal.pone.0044052] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 07/30/2012] [Indexed: 11/19/2022] Open
Abstract
Background Myocardin is thought to have a key role in smooth muscle cell (SMC) development by acting on CArG-dependent genes. However, it is unclear whether myocardin-induced SMC maturation and increases in agonist-induced calcium signalling are also associated with increases in the expression of non-CArG-dependent SMC-specific genes. Moreover, it is unknown whether myocardin promotes SMC development from human embryonic stem cells. Methodology/Principal Findings The effects of adenoviral-mediated myocardin overexpression on SMC development in human ESC-derived embryoid bodies were investigated using immunofluorescence, flow cytometry and real time RT-PCR. Myocardin overexpression from day 10 to day 28 of embryoid body differentiation increased the number of smooth muscle α-actin+ and smooth muscle myosin heavy chain+ SMC-like cells and increased carbachol-induced contractile function. However, myocardin was found to selectively regulate only CArG-dependent SMC-specific genes. Nevertheless, myocardin expression appeared to be sufficient to specify the SMC lineage. Conclusions/Significance Myocardin increases the development and maturation of SMC-like cells from human embryonic stem cells despite not activating the full repertoire of SMC genes. These findings have implications for vascular tissue engineering and other applications requiring large numbers of functional SMCs.
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Affiliation(s)
- Linda Raphel
- Anne McLaren Laboratory for Regenerative Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Amarnath Talasila
- Anne McLaren Laboratory for Regenerative Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Christine Cheung
- Anne McLaren Laboratory for Regenerative Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Sanjay Sinha
- Anne McLaren Laboratory for Regenerative Medicine, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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65
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Cho HS, Toyokawa G, Daigo Y, Hayami S, Masuda K, Ikawa N, Yamane Y, Maejima K, Tsunoda T, Field HI, Kelly JD, Neal DE, Ponder BAJ, Maehara Y, Nakamura Y, Hamamoto R. The JmjC domain-containing histone demethylase KDM3A is a positive regulator of the G1/S transition in cancer cells via transcriptional regulation of the HOXA1 gene. Int J Cancer 2012; 131:E179-89. [PMID: 22020899 DOI: 10.1002/ijc.26501] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 09/28/2011] [Indexed: 11/08/2022]
Abstract
A number of histone demethylases have been identified and biochemically characterized, yet their biological functions largely remain uncharacterized, particularly in the context of human diseases such as cancer. In this study, we describe important roles for the histone demethylase KDM3A, also known as JMJD1A, in human carcinogenesis. Expression levels of KDM3A were significantly elevated in human bladder carcinomas compared with nonneoplastic bladder tissues (p < 0.0001), when assessed by real-time PCR. We confirmed that some other cancers including lung cancer also overexpressed KDM3A, using cDNA microarray analysis. Treatment of cancer cell lines with small interfering RNA targeting KDM3A significantly knocked down its expression and resulted in the suppression of proliferation. Importantly, we found that KDM3A activates transcription of the HOXA1 gene through demethylating histone H3 at lysine 9 di-methylation by binding to its promoter region. Indeed, expression levels of KDM3A and HOXA1 in several types of cancer cell lines and bladder cancer samples were statistically correlated. We observed the down-regulation of HOXA1 as well as CCND1 after treatment with KDM3A siRNA, indicating G(1) arrest of cancer cells. Together, our results suggest that elevated expression of KDM3A plays a critical role in the growth of cancer cells, and further studies may reveal a cancer therapeutic potential in KDM3A inhibition.
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Affiliation(s)
- Hyun-Soo Cho
- Laboratory of Molecular Medicine, Human Genome Center, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, Japan
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66
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Spin JM, Maegdefessel L, Tsao PS. Vascular smooth muscle cell phenotypic plasticity: focus on chromatin remodelling. Cardiovasc Res 2012; 95:147-55. [PMID: 22362814 DOI: 10.1093/cvr/cvs098] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Differentiated vascular smooth muscle cells (SMCs) retain the capacity to modify their phenotype in response to inflammation or injury. This phenotypic switching is a crucial component of vascular disease, and is partly dependent on epigenetic regulation. An appreciation has been building in the literature for the essential role chromatin remodelling plays both in SMC lineage determination and in influencing changes in SMC behaviour and state. This process includes numerous chromatin regulatory elements and pathways such as histone acetyltransferases, deacetylases, and methyltransferases and other factors that act at SMC-specific marker sites to silence or permit access to the cellular transcriptional machinery and on other key regulatory elements such as myocardin and Kruppel-like factor 4 (KLF4). Various stimuli known to alter the SMC phenotype, such as transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), oxidized phospholipids, and retinoic acid, appear to act in part through effects upon SMC chromatin structure. In recent years, specific covalent histone modifications that appear to establish SMC determinacy have been identified, while others alter the differentiation state. In this article, we review the mechanisms of chromatin remodelling as it applies to the SMC phenotype.
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Affiliation(s)
- Joshua M Spin
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, 300 Pasteur Drive, Falk CVRC, Stanford, CA 94305, USA
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67
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Mack CP. Signaling mechanisms that regulate smooth muscle cell differentiation. Arterioscler Thromb Vasc Biol 2011; 31:1495-505. [PMID: 21677292 DOI: 10.1161/atvbaha.110.221135] [Citation(s) in RCA: 189] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Extensive studies over the last 30 years have demonstrated that vascular smooth muscle cell (SMC) differentiation and phenotypic modulation is controlled by a dynamic array of environmental cues. The identification of the signaling mechanisms by which these environmental cues regulate SMC phenotype has been more difficult because of our incomplete knowledge of the transcription mechanisms that regulate SMC-specific gene expression. However, recent advances in this area have provided significant insight, and the goal of this review is to summarize the signaling mechanisms by which extrinsic cues control SMC differentiation.
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Affiliation(s)
- Christopher P Mack
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599-7525, USA.
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68
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Eom GH, Kim KB, Kim JH, Kim JY, Kim JR, Kee HJ, Kim DW, Choe N, Park HJ, Son HJ, Choi SY, Kook H, Seo SB. Histone methyltransferase SETD3 regulates muscle differentiation. J Biol Chem 2011; 286:34733-42. [PMID: 21832073 DOI: 10.1074/jbc.m110.203307] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Histone lysine methylation, as one of the most important factors in transcriptional regulation, is associated with a various physiological conditions. Using a bioinformatics search, we identified and subsequently cloned mouse SET domain containing 3 (SETD3) with SET (Su(var)3-9, Enhancer-of-zeste and Trithorax) and Rubis-subs-bind domains. SETD3 is a novel histone H3K4 and H3K36 methyltransferase with transcriptional activation activity. SETD3 is expressed abundantly in muscular tissues and, when overexpressed, activates transcription of muscle-related genes, myogenin, muscle creatine kinase (MCK), and myogenic factor 6 (Myf6), thereby inducing muscle cell differentiation. Conversely, knockdown of SETD3 by shRNA significantly retards muscle cell differentiation. In this study, SETD3 was recruited to the myogenin gene promoter along with MyoD where it activated transcription. Together, these data indicate that SETD3 is a H3K4/K36 methyltransferase and plays an important role in the transcriptional regulation of muscle cell differentiation.
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Affiliation(s)
- Gwang Hyeon Eom
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 156-756, Republic of Korea
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69
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Goss AM, Tian Y, Cheng L, Yang J, Zhou D, Cohen ED, Morrisey EE. Wnt2 signaling is necessary and sufficient to activate the airway smooth muscle program in the lung by regulating myocardin/Mrtf-B and Fgf10 expression. Dev Biol 2011; 356:541-52. [PMID: 21704027 DOI: 10.1016/j.ydbio.2011.06.011] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 06/07/2011] [Accepted: 06/08/2011] [Indexed: 02/08/2023]
Abstract
Smooth muscle in the lung is thought to derive from the developing lung mesenchyme. Smooth muscle formation relies upon coordination of both autocrine and paracrine signaling between the budding epithelium and adjacent mesenchyme to govern its proliferation and differentiation. However, the pathways initiating the earliest aspects of smooth muscle specification and differentiation in the lung are poorly understood. Here, we identify the Wnt2 ligand as a critical regulator of the earliest aspects of lung airway smooth muscle development. Using Wnt2 loss and gain of function models, we show that Wnt2 signaling is necessary and sufficient for activation of a transcriptional and signaling network critical for smooth muscle specification and differentiation including myocardin/Mrtf-B and the signaling factor Fgf10. These studies place Wnt2 high in a hierarchy of signaling molecules that promote the earliest aspects of lung airway smooth muscle development.
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Affiliation(s)
- Ashley M Goss
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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70
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Zhang QJ, Chen HZ, Wang L, Liu DP, Hill JA, Liu ZP. The histone trimethyllysine demethylase JMJD2A promotes cardiac hypertrophy in response to hypertrophic stimuli in mice. J Clin Invest 2011; 121:2447-56. [PMID: 21555854 DOI: 10.1172/jci46277] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 03/23/2011] [Indexed: 01/02/2023] Open
Abstract
Cardiac hypertrophy and failure are accompanied by a reprogramming of gene expression that involves transcription factors and chromatin remodeling enzymes. Little is known about the roles of histone methylation and demethylation in this process. To understand the role of JMJD2A, a histone trimethyl demethylase, in cardiac hypertrophy, we generated mouse lines with heart-specific Jmjd2a deletion (hKO) and overexpression (Jmjd2a-Tg). Jmjd2a hKO and Jmjd2a-Tg mice had no overt baseline phenotype, but did demonstrate altered responses to cardiac stresses. While inactivation of Jmjd2a resulted in an attenuated hypertrophic response to transverse aortic constriction-induced (TAC-induced) pressure overload, Jmjd2a-Tg mice displayed exacerbated cardiac hypertrophy. We identified four-and-a-half LIM domains 1 (FHL1), a key component of the mechanotransducer machinery in the heart, as a direct target of JMJD2A. JMJD2A bound to the FHL1 promoter in response to TAC, upregulated FHL1 expression, and downregulated H3K9 trimethylation. Upregulation of FHL1 by JMJD2A was mediated through SRF and myocardin and required its demethylase activity. The expression of JMJD2A was upregulated in human hypertrophic cardiomyopathy patients. Our studies reveal that JMJD2A promotes cardiac hypertrophy under pathological conditions and suggest what we believe to be a novel mechanism for JMJD2A in reprogramming of gene expression involved in cardiac hypertrophy.
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Affiliation(s)
- Qing-Jun Zhang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9148, USA
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71
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Majesky MW, Dong XR, Regan JN, Hoglund VJ. Vascular smooth muscle progenitor cells: building and repairing blood vessels. Circ Res 2011; 108:365-77. [PMID: 21293008 DOI: 10.1161/circresaha.110.223800] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Molecular pathways that control the specification, migration, and number of available smooth muscle progenitor cells play key roles in determining blood vessel size and structure, capacity for tissue repair, and progression of age-related disorders. Defects in these pathways produce malformations of developing blood vessels, depletion of smooth muscle progenitor cell pools for vessel wall maintenance and repair, and aberrant activation of alternative differentiation pathways in vascular disease. A better understanding of the molecular mechanisms that uniquely specify and maintain vascular smooth muscle cell precursors is essential if we are to use advances in stem and progenitor cell biology and somatic cell reprogramming for applications directed to the vessel wall.
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Affiliation(s)
- Mark W Majesky
- Seattle Children's Research Institute, University of Washington, 1900 Ninth Ave, M/S C9S-5, Seattle, WA 98101, USA.
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72
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Fang F, Yang Y, Yuan Z, Gao Y, Zhou J, Chen Q, Xu Y. Myocardin-related transcription factor A mediates OxLDL-induced endothelial injury. Circ Res 2011; 108:797-807. [PMID: 21330600 DOI: 10.1161/circresaha.111.240655] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
RATIONALE Atherosclerosis proceeds through a multistep reaction that begins with endothelial injury caused by a host of stress signals, among which oxidized low-density lipoprotein (oxLDL) plays a critical role. OxLDL disrupts normal functionality of the endothelium by upregulating adhesion molecules (eg, ICAM-1) and concomitantly downregulating endothelial nitric oxide synthase (eNOS) expression. The transcriptional modulator that mediates the cellular response to oxLDL remains largely obscure. OBJECTIVE Our goal was to determine whether myocardin-related transcription factor (MRTF)-A, a key protein involved in the transcriptional regulation of smooth muscle cell phenotype, is responsible for the endothelial injury by oxLDL, and, if so, how MRTF-A promotes the proatherogenic agenda initiated by oxLDL. METHODS AND RESULTS OxLDL stimulated the expression of MRTF-A in endothelial cells as evidenced by Western blotting and immunofluorescence. Overexpression of MRTF-A synergistically enhanced the induction of ICAM-1 and suppression of eNOS by oxLDL. In contrast, disruption of MRTF-A, either by small interfering RNA or dominant negative mutation, abrogated the pathogenic program triggered by oxLDL. Finally, chromatin immunoprecipitation assays indicate that oxLDL preferentially augmented MRTF-A binding to ICAM-1 and eNOS promoters and that MRTF-A drove differential epigenetic alterations taking place on these promoters in response to oxLDL. CONCLUSIONS Therefore, our data provide the first demonstration that MRTF-A is critically linked to pivotal pathophysiological events in the vascular endothelium.
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Affiliation(s)
- Fei Fang
- Nanjing Medical University, 140 Hanzhong Rd., Nanjing, Jiangsu, China.
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73
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Martin-Garrido A, Brown DI, Lyle AN, Dikalova A, Seidel-Rogol B, Lassègue B, San Martín A, Griendling KK. NADPH oxidase 4 mediates TGF-β-induced smooth muscle α-actin via p38MAPK and serum response factor. Free Radic Biol Med 2011; 50:354-62. [PMID: 21074607 PMCID: PMC3032946 DOI: 10.1016/j.freeradbiomed.2010.11.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 10/12/2010] [Accepted: 11/04/2010] [Indexed: 12/18/2022]
Abstract
In contrast to other cell types, vascular smooth muscle cells modify their phenotype in response to external signals. NADPH oxidase 4 (Nox4) is critical for maintenance of smooth muscle gene expression; however, the underlying mechanisms are incompletely characterized. Using smooth muscle α-actin (SMA) as a prototypical smooth muscle gene and transforming growth factor-β (TGF-β) as a differentiating agent, we examined Nox4-dependent signaling. TGF-β increases Nox4 expression and activity in human aortic smooth muscle cells (HASMC). Transfection of HASMC with siRNA against Nox4 (siNox4) abolishes TGF-β-induced SMA expression and stress fiber formation. siNox4 also significantly inhibits TGF-β-stimulated p38MAPK phosphorylation, as well as that of its substrate, mitogen-activated protein kinase-activated protein kinase-2. Moreover, the p38MAPK inhibitor SB-203580 nearly completely blocks the SMA increase induced by TGF-β. Inhibition of either p38MAPK or NADPH oxidase-derived reactive oxygen species impairs the TGF-β-induced phosphorylation of Ser103 on serum response factor (SRF) and reduces its transcriptional activity. Binding of SRF to myocardin-related transcription factor (MRTF) is also necessary, because downregulation of MRTF by siRNA abolishes TGF-β-induced SMA expression. Taken together, these data suggest that Nox4 regulates SMA expression via activation of a p38MAPK/SRF/MRTF pathway in response to TGF-β.
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Affiliation(s)
- Abel Martin-Garrido
- Division of Cardiology, Department of Medicine, Emory University, Atlanta, GA 30322, USA
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74
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Spin JM, Quertermous T, Tsao PS. Chromatin remodeling pathways in smooth muscle cell differentiation, and evidence for an integral role for p300. PLoS One 2010; 5:e14301. [PMID: 21179216 PMCID: PMC3001469 DOI: 10.1371/journal.pone.0014301] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 11/15/2010] [Indexed: 11/25/2022] Open
Abstract
Background Phenotypic alteration of vascular smooth muscle cells (SMC) in response to injury or inflammation is an essential component of vascular disease. Evidence suggests that this process is dependent on epigenetic regulatory processes. P300, a histone acetyltransferase (HAT), activates crucial muscle-specific promoters in terminal (non-SMC) myocyte differentiation, and may be essential to SMC modulation as well. Results We performed a subanalysis examining transcriptional time-course microarray data obtained using the A404 model of SMC differentiation. Numerous chromatin remodeling genes (up to 62% of such genes on our array platform) showed significant regulation during differentiation. Members of several chromatin-remodeling families demonstrated involvement, including factors instrumental in histone modification, chromatin assembly-disassembly and DNA silencing, suggesting complex, multi-level systemic epigenetic regulation. Further, trichostatin A, a histone deacetylase inhibitor, accelerated expression of SMC differentiation markers in this model. Ontology analysis indicated a high degree of p300 involvement in SMC differentiation, with 60.7% of the known p300 interactome showing significant expression changes. Knockdown of p300 expression accelerated SMC differentiation in A404 cells and human SMCs, while inhibition of p300 HAT activity blunted SMC differentiation. The results suggest a central but complex role for p300 in SMC phenotypic modulation. Conclusions Our results support the hypothesis that chromatin remodeling is important for SMC phenotypic switching, and detail wide-ranging involvement of several epigenetic modification families. Additionally, the transcriptional coactivator p300 may be partially degraded during SMC differentiation, leaving an activated subpopulation with increased HAT activity and SMC differentiation-gene specificity.
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Affiliation(s)
- Joshua M Spin
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America.
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75
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Chen H, Kluz T, Zhang R, Costa M. Hypoxia and nickel inhibit histone demethylase JMJD1A and repress Spry2 expression in human bronchial epithelial BEAS-2B cells. Carcinogenesis 2010; 31:2136-44. [PMID: 20881000 DOI: 10.1093/carcin/bgq197] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Epigenetic silencing of tumor suppressor genes commonly occurs in human cancers via increasing DNA methylation and repressive histone modifications at gene promoters. However, little is known about how pathogenic environmental factors contribute to cancer development by affecting epigenetic regulatory mechanisms. Previously, we reported that both hypoxia and nickel (an environmental carcinogen) increased global histone H3 lysine 9 methylation in cells through inhibiting a novel class of iron- and α-ketoglutarate-dependent histone demethylases. Here, we investigated whether inhibition of histone demethylase JMJD1A by hypoxia and nickel could lead to repression/silencing of JMJD1A-targeted gene(s). By using Affymetrix GeneChip and ChIP-on-chip technologies, we identified Spry2 gene, a key regulator of receptor tyrosine kinase/extracellular signal-regulated kinase (ERK) signaling, as one of the JMJD1A-targeted genes in human bronchial epithelial BEAS-2B cells. Both hypoxia and nickel exposure increased the level of H3K9me2 at the Spry2 promoter by inhibiting JMJD1A, which probably led to a decreased expression of Spry2 in BEAS-2B cells. Repression of Spry2 potentiated the nickel-induced ERK phosphorylation, and forced expression of Spry2 in BEAS-2B cells decreased the nickel-induced ERK phosphorylation and significantly suppressed nickel-induced anchorage-independent growth. Taken together, our results suggest that histone demethylases could be targets of environmental carcinogens and their inhibition may lead to altered gene expression and eventually carcinogenesis.
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Affiliation(s)
- Haobin Chen
- Department of Environmental Medicine, New York University of School of Medicine, 550 First Avenue, New York, NY 10016, USA.
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76
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Chen H, Giri NC, Zhang R, Yamane K, Zhang Y, Maroney M, Costa M. Nickel ions inhibit histone demethylase JMJD1A and DNA repair enzyme ABH2 by replacing the ferrous iron in the catalytic centers. J Biol Chem 2010; 285:7374-83. [PMID: 20042601 PMCID: PMC2844186 DOI: 10.1074/jbc.m109.058503] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2009] [Revised: 12/23/2009] [Indexed: 01/20/2023] Open
Abstract
Iron- and 2-oxoglutarate-dependent dioxygenases are a diverse family of non-heme iron enzymes that catalyze various important oxidations in cells. A key structural motif of these dioxygenases is a facial triad of 2-histidines-1-carboxylate that coordinates the Fe(II) at the catalytic site. Using histone demethylase JMJD1A and DNA repair enzyme ABH2 as examples, we show that this family of dioxygenases is highly sensitive to inhibition by carcinogenic nickel ions. We find that, with iron, the 50% inhibitory concentrations of nickel (IC(50) [Ni(II)]) are 25 microm for JMJD1A and 7.5 microm for ABH2. Without iron, JMJD1A is 10 times more sensitive to nickel inhibition with an IC(50) [Ni(II)] of 2.5 microm, and approximately one molecule of Ni(II) inhibits one molecule of JMJD1A, suggesting that nickel causes inhibition by replacing the iron. Furthermore, nickel-bound JMJD1A is not reactivated by excessive iron even up to a 2 mm concentration. Using x-ray absorption spectroscopy, we demonstrate that nickel binds to the same site in ABH2 as iron, and replacement of the iron by nickel does not prevent the binding of the cofactor 2-oxoglutarate. Finally, we show that nickel ions target and inhibit JMJD1A in intact cells, and disruption of the iron-binding site decreases binding of nickel ions to ABH2 in intact cells. Together, our results reveal that the members of this dioxygenase family are specific targets for nickel ions in cells. Inhibition of these dioxygenases by nickel is likely to have widespread impacts on cells (e.g. impaired epigenetic programs and DNA repair) and may eventually lead to cancer development.
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Affiliation(s)
- Haobin Chen
- From the Department of Environmental Medicine, New York University of School of Medicine, New York, New York 10016
| | - Nitai Charan Giri
- the Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01002, and
| | - Ronghe Zhang
- From the Department of Environmental Medicine, New York University of School of Medicine, New York, New York 10016
| | - Kenichi Yamane
- the Department of Biochemistry and Biophysics, Howard Hughes Medical Institute, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Yi Zhang
- the Department of Biochemistry and Biophysics, Howard Hughes Medical Institute, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Michael Maroney
- the Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01002, and
| | - Max Costa
- From the Department of Environmental Medicine, New York University of School of Medicine, New York, New York 10016
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Regulation of the histone demethylase JMJD1A by hypoxia-inducible factor 1 alpha enhances hypoxic gene expression and tumor growth. Mol Cell Biol 2010; 30:344-53. [PMID: 19858293 DOI: 10.1128/mcb.00444-09] [Citation(s) in RCA: 269] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The hypoxia-inducible transcription factors (HIFs) directly and indirectly mediate cellular adaptation to reduced oxygen tensions. Recent studies have shown that the histone demethylase genes JMJD1A, JMJD2B, and JARID1B are HIF targets, suggesting that HIFs indirectly influence gene expression at the level of histone methylation under hypoxia. In this study, we identify a subset of hypoxia-inducible genes that are dependent on JMJD1A in both renal cell and colon carcinoma cell lines. JMJD1A regulates the expression of adrenomedullin (ADM) and growth and differentiation factor 15 (GDF15) under hypoxia by decreasing promoter histone methylation. In addition, we demonstrate that loss of JMJD1A is sufficient to reduce tumor growth in vivo, demonstrating that histone demethylation plays a significant role in modulating growth within the tumor microenvironment. Thus, hypoxic regulation of JMJD1A acts as a signal amplifier to facilitate hypoxic gene expression, ultimately enhancing tumor growth.
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79
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Liu Z, Zhou S, Liao L, Chen X, Meistrich M, Xu J. Jmjd1a demethylase-regulated histone modification is essential for cAMP-response element modulator-regulated gene expression and spermatogenesis. J Biol Chem 2009; 285:2758-70. [PMID: 19910458 DOI: 10.1074/jbc.m109.066845] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Spermatogenesis, a fundamental process in the male reproductive system, requires a series of tightly controlled epigenetic and genetic events in germ cells ranging from spermatogonia to spermatozoa. Jmjd1a is a key epigenetic regulator expressed in the testis. It specifically demethylates mono- and di-methylated histone H3 lysine 9 (H3K9me1 and H3K9me2) but not tri-methylated H3K9 (H3K9me3). In this study, we generated a Jmjd1a antibody for immunohistochemistry and found Jmjd1a was specifically produced in pachytene and secondary spermatocytes. Disruption of the Jmjd1a gene in mice significantly increased H3K9me1 and H3K9me2 levels in pachytene spermatocytes and early elongating spermatids without affecting H3K9me3 levels. Concurrently, the levels of histone acetylation were decreased in Jmjd1a knock-out germ cells. This suggests Jmjd1a promotes transcriptional activation by lowering histone methylation and increasing histone acetylation. Interestingly, the altered histone modifications in Jmjd1a-deficient germ cells caused diminished cAMP-response element modulator (Crem) recruitment to chromatin and decreased expression of the Crem coactivator Act and their target genes Tnp1 (transition protein 1), Tnp2, Prm1 (protamine 1), and Prm2, all of which are essential for chromatin condensation in spermatids. In agreement with these findings, Jmjd1a deficiency caused extensive germ cell apoptosis and blocked spermatid elongation, resulting in severe oligozoospermia, small testes, and infertility in male mice. These results indicate that the Jmjd1a-controlled epigenetic histone modifications are crucial for Crem-regulated gene expression and spermatogenesis.
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Affiliation(s)
- Zhaoliang Liu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Texas A&M University Health Science Center, Texas 77030, USA
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80
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Yang J, Ledaki I, Turley H, Gatter KC, Montero JCM, Li JL, Harris AL. Role of hypoxia-inducible factors in epigenetic regulation via histone demethylases. Ann N Y Acad Sci 2009; 1177:185-97. [PMID: 19845621 DOI: 10.1111/j.1749-6632.2009.05027.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Eukaryotic chromatin is subject to multiple posttranslational histone modifications such as acetylation, methylation, phosphorylation, and ubiquitination. These various covalent modifications have been proposed to constitute a "histone code," playing important roles in the establishment of global chromatin environments, transcription, DNA repair, and DNA replication. Among these modifications, histone methylation specifies regulatory marks that delineate transcriptionally active and inactive chromatin. These histone methyl marks were considered irreversible; however, recent identification of site-specific histone demethylases demonstrates that histone methylation is dynamically regulated, which may allow cells to rapidly change chromatin conformation to adapt to environmental stresses or intrinsic stimuli. Of major interest is the observation that these histone demethylase enzymes, which are in the Jumonji gene family, require oxygen to function and, in some cases, are induced by hypoxia in an HIFalpha-dependent manner. This provides a new mechanism for regulation of the response to hypoxia.
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Affiliation(s)
- Jun Yang
- Cancer Research UK, Molecular Oncology Laboratories, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
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81
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Blaker AL, Taylor JM, Mack CP. PKA-dependent phosphorylation of serum response factor inhibits smooth muscle-specific gene expression. Arterioscler Thromb Vasc Biol 2009; 29:2153-60. [PMID: 19778940 DOI: 10.1161/atvbaha.109.197285] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Our goal was to identify phosphorylation sites that regulate serum response factor (SRF) activity to gain a better understanding of the signaling mechanisms that regulate SRF's involvement in smooth muscle cell (SMC)-specific and early response gene expression. METHODS AND RESULTS By screening phosphorylation-deficient and mimetic mutations in SRF(-/-) embryonic stem cells, we identified T159 as a phosphorylation site that significantly inhibits SMC-specific gene expression in an embryonic stem cell model of SMC differentiation. This residue conforms to a highly conserved consensus cAMP-dependent protein kinase (PKA) site, and in vitro and in vivo labeling studies demonstrated that it was phosphorylated by PKA. Results from gel shift and chromatin immunoprecipitation assays demonstrated that T159 phosphorylation inhibited SRF binding to SMC-specific CArG elements. Interestingly, the myocardin factors could at least partially rescue the effects of the T159D mutation under some conditions, but this response was promoter specific. Finally, PKA signaling had much less of an effect on c-fos promoter activity and SRF binding to the c-fos CArG. CONCLUSIONS Our results indicate that phosphorylation of SRF by PKA inhibits SMC-specific transcription suggesting a novel signaling mechanism for the control of SMC phenotype.
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Affiliation(s)
- Alicia L Blaker
- Department of Pathology, University of North Carolina, Chapel Hill, NC 27599-7525, USA
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82
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Zhou W, Negash S, Liu J, Raj JU. Modulation of pulmonary vascular smooth muscle cell phenotype in hypoxia: role of cGMP-dependent protein kinase and myocardin. Am J Physiol Lung Cell Mol Physiol 2009; 296:L780-9. [PMID: 19251841 DOI: 10.1152/ajplung.90295.2008] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have previously reported that in ovine fetal pulmonary venous smooth muscle cells (FPVSMC), decreased expression of cGMP-dependent protein kinase (PKG) by hypoxia could explain hypoxia-induced SMC phenotype modulation. In this study, we investigated the role of myocardin, a possible downstream effector of PKG, in SMC phenotype modulation induced by 1 and 24 h of hypoxia. Hypoxia for 1 h induced the phosphorylation of E-26-like protein 1 (Elk-1), indicating a quick activation of Elk-1 after hypoxia. Either hypoxia (1 h) or treatment with DT-3, a PKG inhibitor, increased associations of Elk-1 with myosin heavy chain (MHC) gene and serum response factor (SRF), which was paralleled by a decrease in association of myocardin with MHC gene and SRF. Exposure to hypoxia of FPVSMC for 24 h significantly decreased the promoter activity of multiple SMC marker genes, downregulated protein and mRNA expression of myocardin, and upregulated mRNA expression of Elk-1, but had no significant effects on the phosphorylation of Elk-1. Inhibition of myocardin by siRNA transfection downregulated the expression of SMC marker proteins, while overexpression of myocardin prevented the hypoxia-induced decrease in expression of SMC marker proteins. Inhibition of PKG by siRNA transfection downregulated the expression of myocardin, but upregulated that of Elk-1. Overexpression of PKG prevented hypoxia-induced effects on protein expression of myocardin and Elk-1. These data suggest that PKG induces displacement of myocardin from SRF and upregulates myocardin expression, thus activating the SMC genes transcription. The inhibitory effects of hypoxia on PKG may explain hypoxia-induced SMC phenotype modulation by decreasing the effects of PKG on myocardin.
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Affiliation(s)
- Weilin Zhou
- Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA 90502, USA.
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83
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Beyer S, Kristensen MM, Jensen KS, Johansen JV, Staller P. The histone demethylases JMJD1A and JMJD2B are transcriptional targets of hypoxia-inducible factor HIF. J Biol Chem 2008; 283:36542-52. [PMID: 18984585 PMCID: PMC2662309 DOI: 10.1074/jbc.m804578200] [Citation(s) in RCA: 264] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 10/29/2008] [Indexed: 12/31/2022] Open
Abstract
Posttranslational histone modifications serve to store epigenetic information and control both nucleosome assembly and recruitment of non-histone proteins. Histone methylation occurs on arginine and lysine residues and is involved in the regulation of gene transcription. A dynamic control of these modifications is exerted by histone methyltransferases and the recently discovered histone demethylases. Here we show that the hypoxia-inducible factor HIF-1alpha binds to specific recognition sites in the genes encoding the jumonji family histone demethylases JMJD1A and JMJD2B and induces their expression. Accordingly, hypoxic cells express elevated levels of JMJD1A and JMJD2B mRNA and protein. Furthermore, we find increased expression of JMJD1A and JMJD2B in renal cancer cells that have lost the von Hippel Lindau tumor suppressor protein VHL and therefore display a deregulated expression of hypoxia-inducible factor. Studies on ectopically expressed JMJD1A and JMJD2B indicate that both proteins retain their histone lysine demethylase activity in hypoxia and thereby might impact the hypoxic gene expression program.
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Affiliation(s)
- Sophie Beyer
- Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
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84
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Cloos PAC, Christensen J, Agger K, Helin K. Erasing the methyl mark: histone demethylases at the center of cellular differentiation and disease. Genes Dev 2008; 22:1115-40. [PMID: 18451103 DOI: 10.1101/gad.1652908] [Citation(s) in RCA: 507] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The enzymes catalyzing lysine and arginine methylation of histones are essential for maintaining transcriptional programs and determining cell fate and identity. Until recently, histone methylation was regarded irreversible. However, within the last few years, several families of histone demethylases erasing methyl marks associated with gene repression or activation have been identified, underscoring the plasticity and dynamic nature of histone methylation. Recent discoveries have revealed that histone demethylases take part in large multiprotein complexes synergizing with histone deacetylases, histone methyltransferases, and nuclear receptors to control developmental and transcriptional programs. Here we review the emerging biochemical and biological functions of the histone demethylases and discuss their potential involvement in human diseases, including cancer.
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Affiliation(s)
- Paul A C Cloos
- Biotech Research and Innovation Centre, University of Copenhagen, DK-2200 Copenhagen, Denmark.
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85
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Long X, Bell RD, Gerthoffer WT, Zlokovic BV, Miano JM. Myocardin is sufficient for a smooth muscle-like contractile phenotype. Arterioscler Thromb Vasc Biol 2008; 28:1505-10. [PMID: 18451334 DOI: 10.1161/atvbaha.108.166066] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Myocardin (Myocd) is a strong coactivator that binds the serum response factor (SRF) transcription factor over CArG elements embedded within smooth muscle cell (SMC) and cardiac muscle cyto-contractile genes. Here, we sought to ascertain whether Myocd-mediated gene expression confers a structural and physiological cardiac or SMC phenotype. METHODS AND RESULTS Adenoviral-mediated expression of Myocd in the BC(3)H1 cell line induces cardiac and SMC genes while suppressing both skeletal muscle markers and cell growth. Immunofluorescence microscopy shows that SRF and a SMC-like cyto-contractile apparatus are elevated with Myocd overexpression. A short hairpin RNA to Srf impairs BC(3)H1 cyto-architecture; however, cotransduction with Myocd results in complete restoration of the cyto-architecture. Electron microscopic studies demonstrate a SMC ultrastructural phenotype with no evidence for cardiac sarcomerogenesis. Biochemical and time-lapsed videomicroscopy assays reveal clear evidence for Myocd-induced SMC-like contraction. CONCLUSIONS Myocd is sufficient for the establishment of a SMC-like contractile phenotype.
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Affiliation(s)
- Xiaochun Long
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine & Dentistry, 211 Bailey Road, Rochester, New York 14586, USA
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