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Ngubo M, Chen Z, McDonald D, Karimpour R, Shrestha A, Yockell-Lelièvre J, Laurent A, Besong OTO, Tsai EC, Dilworth FJ, Hendzel MJ, Stanford WL. Progeria-based vascular model identifies networks associated with cardiovascular aging and disease. Aging Cell 2024:e14150. [PMID: 38576084 DOI: 10.1111/acel.14150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 04/06/2024] Open
Abstract
Hutchinson-Gilford Progeria syndrome (HGPS) is a lethal premature aging disorder caused by a de novo heterozygous mutation that leads to the accumulation of a splicing isoform of Lamin A termed progerin. Progerin expression deregulates the organization of the nuclear lamina and the epigenetic landscape. Progerin has also been observed to accumulate at low levels during normal aging in cardiovascular cells of adults that do not carry genetic mutations linked with HGPS. Therefore, the molecular mechanisms that lead to vascular dysfunction in HGPS may also play a role in vascular aging-associated diseases, such as myocardial infarction and stroke. Here, we show that HGPS patient-derived vascular smooth muscle cells (VSMCs) recapitulate HGPS molecular hallmarks. Transcriptional profiling revealed cardiovascular disease remodeling and reactive oxidative stress response activation in HGPS VSMCs. Proteomic analyses identified abnormal acetylation programs in HGPS VSMC replication fork complexes, resulting in reduced H4K16 acetylation. Analysis of acetylation kinetics revealed both upregulation of K16 deacetylation and downregulation of K16 acetylation. This correlates with abnormal accumulation of error-prone nonhomologous end joining (NHEJ) repair proteins on newly replicated chromatin. The knockdown of the histone acetyltransferase MOF recapitulates preferential engagement of NHEJ repair activity in control VSMCs. Additionally, we find that primary donor-derived coronary artery vascular smooth muscle cells from aged individuals show similar defects to HGPS VSMCs, including loss of H4K16 acetylation. Altogether, we provide insight into the molecular mechanisms underlying vascular complications associated with HGPS patients and normative aging.
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Affiliation(s)
- Mzwanele Ngubo
- The Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
| | - Zhaoyi Chen
- The Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Darin McDonald
- Cross Cancer Institute and the Department of Experimental Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Rana Karimpour
- Cross Cancer Institute and the Department of Experimental Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Amit Shrestha
- The Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Julien Yockell-Lelièvre
- The Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Aurélie Laurent
- The Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Université de Strasbourg, Strasbourg, France
| | - Ojong Tabi Ojong Besong
- The Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- School of Bioscience, University of Skövde, Skövde, Sweden
| | - Eve C Tsai
- The Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - F Jeffrey Dilworth
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Michael J Hendzel
- Cross Cancer Institute and the Department of Experimental Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - William L Stanford
- The Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology & Immunology, University of Ottawa, Ottawa, Ontario, Canada
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2
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Geara P, Dilworth FJ. Epigenetic integration of signaling from the regenerative environment. Curr Top Dev Biol 2024; 158:341-374. [PMID: 38670712 DOI: 10.1016/bs.ctdb.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024]
Abstract
Skeletal muscle has an extraordinary capacity to regenerate itself after injury due to the presence of tissue-resident muscle stem cells. While these muscle stem cells are the primary contributor to the regenerated myofibers, the process occurs in a regenerative microenvironment where multiple different cell types act in a coordinated manner to clear the damaged myofibers and restore tissue homeostasis. In this regenerative environment, immune cells play a well-characterized role in initiating repair by establishing an inflammatory state that permits the removal of dead cells and necrotic muscle tissue at the injury site. More recently, it has come to be appreciated that the immune cells also play a crucial role in communicating with the stem cells within the regenerative environment to help coordinate the timing of repair events through the secretion of cytokines, chemokines, and growth factors. Evidence also suggests that stem cells can help modulate the extent of the inflammatory response by signaling to the immune cells, demonstrating a cross-talk between the different cells in the regenerative environment. Here, we review the current knowledge on the innate immune response to sterile muscle injury and provide insight into the epigenetic mechanisms used by the cells in the regenerative niche to integrate the cellular cross-talk required for efficient muscle repair.
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Affiliation(s)
- Perla Geara
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI, United States
| | - F Jeffrey Dilworth
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI, United States.
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3
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Nakka K, Hachmer S, Mokhtari Z, Kovac R, Bandukwala H, Bernard C, Li Y, Xie G, Liu C, Fallahi M, Megeney LA, Gondin J, Chazaud B, Brand M, Zha X, Ge K, Dilworth FJ. JMJD3 activated hyaluronan synthesis drives muscle regeneration in an inflammatory environment. Science 2022; 377:666-669. [PMID: 35926054 DOI: 10.1126/science.abm9735] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Muscle stem cells (MuSCs) reside in a specialized niche that ensures their regenerative capacity. Although we know that innate immune cells infiltrate the niche in response to injury, it remains unclear how MuSCs adapt to this altered environment for initiating repair. Here, we demonstrate that inflammatory cytokine signaling from the regenerative niche impairs the ability of quiescent MuSCs to reenter the cell cycle. The histone H3 lysine 27 (H3K27) demethylase JMJD3, but not UTX, allowed MuSCs to overcome inhibitory inflammation signaling by removing trimethylated H3K27 (H3K27me3) marks at the Has2 locus to initiate production of hyaluronic acid, which in turn established an extracellular matrix competent for integrating signals that direct MuSCs to exit quiescence. Thus, JMJD3-driven hyaluronic acid synthesis plays a proregenerative role that allows MuSC adaptation to inflammation and the initiation of muscle repair.
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Affiliation(s)
- Kiran Nakka
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Sarah Hachmer
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Zeinab Mokhtari
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Radmila Kovac
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Hina Bandukwala
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Clara Bernard
- Institut NeuroMyoGène, Unité Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS 5261, INSERM U1315, Université de Lyon, Lyon, France
| | - Yuefeng Li
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Guojia Xie
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Chengyu Liu
- Transgenic Core, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Magid Fallahi
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Lynn A Megeney
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Julien Gondin
- Institut NeuroMyoGène, Unité Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS 5261, INSERM U1315, Université de Lyon, Lyon, France
| | - Bénédicte Chazaud
- Institut NeuroMyoGène, Unité Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS 5261, INSERM U1315, Université de Lyon, Lyon, France
| | - Marjorie Brand
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,LIFE Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Xiaohui Zha
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Kai Ge
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - F Jeffrey Dilworth
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,LIFE Research Institute, University of Ottawa, Ottawa, ON, Canada
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4
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Campbell TM, Dilworth FJ, Allan DS, Trudel G. The Hunt Is On! In Pursuit of the Ideal Stem Cell Population for Cartilage Regeneration. Front Bioeng Biotechnol 2022; 10:866148. [PMID: 35711627 PMCID: PMC9196866 DOI: 10.3389/fbioe.2022.866148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 04/27/2022] [Indexed: 01/15/2023] Open
Abstract
Cartilage injury and degeneration are hallmarks of osteoarthritis (OA), the most common joint disease. OA is a major contributor to pain, loss of function, and reduced quality of life. Over the last decade, considerable research efforts have focused on cell-based therapies, including several stem cell-derived approaches to reverse the cartilage alterations associated with OA. Although several tissue sources for deriving cell-based therapies have been identified, none of the resident stem cell populations have adequately fulfilled the promise of curing OA. Indeed, many cell products do not contain true stem cells. As well, issues with aggressive marketing efforts, combined with a lack of evidence regarding efficacy, lead the several national regulatory bodies to discontinue the use of stem cell therapy for OA until more robust evidence becomes available. A review of the evidence is timely to address the status of cell-based cartilage regeneration. The promise of stem cell therapy is not new and has been used successfully to treat non-arthritic diseases, such as hematopoietic and muscle disorders. These fields of regenerative therapy have the advantage of a considerable foundation of knowledge in the area of stem cell repair mechanisms, the role of the stem cell niche, and niche-supporting cells. This foundation is lacking in the field of cartilage repair. So, where should we look for the ideal stem cell to regenerate cartilage? It has recently been discovered that cartilage itself may contain a population of SC-like progenitors. Other potential tissues include stem cell-rich dental pulp and the adolescent growth plate, the latter of which contains chondrocyte progenitors essential for producing the cartilage scaffold needed for bone growth. In this article, we review the progress on stem cell therapies for arthritic disorders, focusing on the various stem cell populations previously used for cartilage regeneration, successful cases of stem cell therapies in muscle and hemopoietic disorders, some of the reasons why these other fields have been successful (i.e., “lessons learned” to be applied to OA stem cell therapy), and finally, novel potential sources of stem cells for regenerating damaged cartilage in vivo.
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Affiliation(s)
- T Mark Campbell
- Elisabeth Bruyère Hospital, Ottawa, ON, Canada.,Bone and Joint Research Laboratory, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - F Jeffrey Dilworth
- Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - David S Allan
- Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada
| | - Guy Trudel
- Bone and Joint Research Laboratory, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada.,Department of Biochemistry, Immunology and Microbiology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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5
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Bell RAV, Al-Khalaf MH, Brunette S, Alsowaida D, Chu A, Bandukwala H, Dechant G, Apostolova G, Dilworth FJ, Megeney LA. Chromatin Reorganization during Myoblast Differentiation Involves the Caspase-Dependent Removal of SATB2. Cells 2022; 11:cells11060966. [PMID: 35326417 PMCID: PMC8946544 DOI: 10.3390/cells11060966] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/27/2022] [Accepted: 03/09/2022] [Indexed: 11/17/2022] Open
Abstract
The induction of lineage-specific gene programs are strongly influenced by alterations in local chromatin architecture. However, key players that impact this genome reorganization remain largely unknown. Here, we report that the removal of the special AT-rich binding protein 2 (SATB2), a nuclear protein known to bind matrix attachment regions, is a key event in initiating myogenic differentiation. The deletion of myoblast SATB2 in vitro initiates chromatin remodeling and accelerates differentiation, which is dependent on the caspase 7-mediated cleavage of SATB2. A genome-wide analysis indicates that SATB2 binding within chromatin loops and near anchor points influences both loop and sub-TAD domain formation. Consequently, the chromatin changes that occur with the removal of SATB2 lead to the derepression of differentiation-inducing factors while also limiting the expression of genes that inhibit this cell fate change. Taken together, this study demonstrates that the temporal control of the SATB2 protein is critical in shaping the chromatin environment and coordinating the myogenic differentiation program.
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Affiliation(s)
- Ryan A. V. Bell
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Mohammad H. Al-Khalaf
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- University of Ottawa Heart Institute, Ottawa, ON K1Y 4W7, Canada
| | - Steve Brunette
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
| | - Dalal Alsowaida
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Alphonse Chu
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Hina Bandukwala
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
| | - Georg Dechant
- Institute of Neuroscience, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (G.D.); (G.A.)
| | - Galina Apostolova
- Institute of Neuroscience, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (G.D.); (G.A.)
| | - F. Jeffrey Dilworth
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Lynn A. Megeney
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Correspondence:
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6
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Li Y, Nakka K, Olender T, Gingras-Gelinas P, Wong MMK, Robinson DCL, Bandukwala H, Palii CG, Neyret O, Brand M, Blais A, Dilworth FJ. Chromatin and transcription factor profiling in rare stem cell populations using CUT&Tag. STAR Protoc 2021; 2:100751. [PMID: 34467227 PMCID: PMC8384913 DOI: 10.1016/j.xpro.2021.100751] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Muscle stem cells (MuSCs) are a rare stem cell population that provides myofibers with a remarkable capacity to regenerate after tissue injury. Here, we have adapted the Cleavage Under Target and Tagmentation technology to the mapping of the chromatin landscape and transcription factor binding in 50,000 activated MuSCs isolated from injured mouse hindlimb muscles. We have applied this same approach to human CD34+ hematopoietic stem and progenitor cells. This protocol could be adapted to any rare stem cell population. For complete details on the use and execution of this protocol, please refer to Robinson et al. (2021). Isolation of muscle stem cells from cardiotoxin-injured tissue CUT&Tag-based mapping of epigenetic landscape and transcription factor enrichment Adaptation of a synthetic spike-in DNA for effective normalization across samples Pipeline for efficient analysis of CUT&Tag sequencing data hosted on Git-hub
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Affiliation(s)
- Yuefeng Li
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Kiran Nakka
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Thomas Olender
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | | | - Matthew Man-Kin Wong
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Daniel C L Robinson
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Hina Bandukwala
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Carmen G Palii
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Odile Neyret
- Molecular Biology Platform, Institut de Recherche Clinique de Montreal, Montreal, QC, Canada
| | - Marjorie Brand
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,LIFE Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Alexandre Blais
- Ottawa Institute for Systems Biology, University of Ottawa, Ottawa, ON, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,CI3, University of Ottawa Centre for Infection, Immunity and Inflammation, Ottawa, ON, Canada
| | - F Jeffrey Dilworth
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,LIFE Research Institute, University of Ottawa, Ottawa, ON, Canada.,Ottawa Institute for Systems Biology, University of Ottawa, Ottawa, ON, Canada
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7
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Sharma T, Robinson DCL, Witwicka H, Dilworth FJ, Imbalzano AN. The Bromodomains of the mammalian SWI/SNF (mSWI/SNF) ATPases Brahma (BRM) and Brahma Related Gene 1 (BRG1) promote chromatin interaction and are critical for skeletal muscle differentiation. Nucleic Acids Res 2021; 49:8060-8077. [PMID: 34289068 PMCID: PMC8373147 DOI: 10.1093/nar/gkab617] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/17/2021] [Accepted: 07/08/2021] [Indexed: 12/12/2022] Open
Abstract
Skeletal muscle regeneration is mediated by myoblasts that undergo epigenomic changes to establish the gene expression program of differentiated myofibers. mSWI/SNF chromatin remodeling enzymes coordinate with lineage-determining transcription factors to establish the epigenome of differentiated myofibers. Bromodomains bind to acetylated lysines on histone N-terminal tails and other proteins. The mutually exclusive ATPases of mSWI/SNF complexes, BRG1 and BRM, contain bromodomains with undefined functional importance in skeletal muscle differentiation. Pharmacological inhibition of mSWI/SNF bromodomain function using the small molecule PFI-3 reduced differentiation in cell culture and in vivo through decreased myogenic gene expression, while increasing cell cycle-related gene expression and the number of cells remaining in the cell cycle. Comparative gene expression analysis with data from myoblasts depleted of BRG1 or BRM showed that bromodomain function was required for a subset of BRG1- and BRM-dependent gene expression. Reduced binding of BRG1 and BRM after PFI-3 treatment showed that the bromodomain is required for stable chromatin binding at target gene promoters to alter gene expression. Our findings demonstrate that mSWI/SNF ATPase bromodomains permit stable binding of the mSWI/SNF ATPases to promoters required for cell cycle exit and establishment of muscle-specific gene expression.
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Affiliation(s)
- Tapan Sharma
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Daniel C L Robinson
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Hanna Witwicka
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - F Jeffrey Dilworth
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Anthony N Imbalzano
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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8
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Esteves de Lima J, Bou Akar R, Machado L, Li Y, Drayton-Libotte B, Dilworth FJ, Relaix F. HIRA stabilizes skeletal muscle lineage identity. Nat Commun 2021; 12:3450. [PMID: 34103504 PMCID: PMC8187366 DOI: 10.1038/s41467-021-23775-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 05/17/2021] [Indexed: 12/26/2022] Open
Abstract
The epigenetic mechanisms coordinating the maintenance of adult cellular lineages and the inhibition of alternative cell fates remain poorly understood. Here we show that targeted ablation of the histone chaperone HIRA in myogenic cells leads to extensive transcriptional modifications, consistent with a role in maintaining skeletal muscle cellular identity. We demonstrate that conditional ablation of HIRA in muscle stem cells of adult mice compromises their capacity to regenerate and self-renew, leading to tissue repair failure. Chromatin analysis of Hira-deficient cells show a significant reduction of histone variant H3.3 deposition and H3K27ac modification at regulatory regions of muscle genes. Additionally, we find that genes from alternative lineages are ectopically expressed in Hira-mutant cells via MLL1/MLL2-mediated increase of H3K4me3 mark at silent promoter regions. Therefore, we conclude that HIRA sustains the chromatin landscape governing muscle cell lineage identity via incorporation of H3.3 at muscle gene regulatory regions, while preventing the expression of alternative lineage genes. The epigenetic mechanisms coordinating the maintenance of adult cellular lineages remain poorly understood. Here the authors demonstrate that HIRA, a H3.3 histone chaperone, establishes the chromatin landscape required for skeletal muscle cell identity.
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Affiliation(s)
| | - Reem Bou Akar
- Univ Paris Est Creteil, INSERM, EnvA, EFS, AP-HP, IMRB, F-94010, Creteil, France
| | - Léo Machado
- Univ Paris Est Creteil, INSERM, EnvA, EFS, AP-HP, IMRB, F-94010, Creteil, France
| | - Yuefeng Li
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | | | - F Jeffrey Dilworth
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Frédéric Relaix
- Univ Paris Est Creteil, INSERM, EnvA, EFS, AP-HP, IMRB, F-94010, Creteil, France.
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9
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Massenet J, Gardner E, Chazaud B, Dilworth FJ. Epigenetic regulation of satellite cell fate during skeletal muscle regeneration. Skelet Muscle 2021; 11:4. [PMID: 33431060 PMCID: PMC7798257 DOI: 10.1186/s13395-020-00259-w] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/20/2020] [Indexed: 12/13/2022] Open
Abstract
In response to muscle injury, muscle stem cells integrate environmental cues in the damaged tissue to mediate regeneration. These environmental cues are tightly regulated to ensure expansion of muscle stem cell population to repair the damaged myofibers while allowing repopulation of the stem cell niche. These changes in muscle stem cell fate result from changes in gene expression that occur in response to cell signaling from the muscle environment. Integration of signals from the muscle environment leads to changes in gene expression through epigenetic mechanisms. Such mechanisms, including post-translational modification of chromatin and nucleosome repositioning, act to make specific gene loci more, or less, accessible to the transcriptional machinery. In youth, the muscle environment is ideally structured to allow for coordinated signaling that mediates efficient regeneration. Both age and disease alter the muscle environment such that the signaling pathways that shape the healthy muscle stem cell epigenome are altered. Altered epigenome reduces the efficiency of cell fate transitions required for muscle repair and contributes to muscle pathology. However, the reversible nature of epigenetic changes holds out potential for restoring cell fate potential to improve muscle repair in myopathies. In this review, we will describe the current knowledge of the mechanisms allowing muscle stem cell fate transitions during regeneration and how it is altered in muscle disease. In addition, we provide some examples of how epigenetics could be harnessed therapeutically to improve regeneration in various muscle pathologies.
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Affiliation(s)
- Jimmy Massenet
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Rd, Mailbox 511, Ottawa, ON, K1H 8L6, Canada.,Institut NeuroMyoGène, Université Claude Bernard Lyon 1, CNRS 5310, INSERM U1217, 8 Rockefeller Ave, 69008, Lyon, France
| | - Edward Gardner
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Rd, Mailbox 511, Ottawa, ON, K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8L6, Canada
| | - Bénédicte Chazaud
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, CNRS 5310, INSERM U1217, 8 Rockefeller Ave, 69008, Lyon, France
| | - F Jeffrey Dilworth
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Rd, Mailbox 511, Ottawa, ON, K1H 8L6, Canada. .,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8L6, Canada. .,LIFE Research Institute, University of Ottawa, Ottawa, ON, K1H 8L6, Canada.
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10
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Nakka K, Kovac R, Wong MMK, Dilworth FJ. Intron Retained, Transcript Detained: Intron Retention as a Hallmark of the Quiescent Satellite Cell State. Dev Cell 2020; 53:623-625. [PMID: 32574590 DOI: 10.1016/j.devcel.2020.05.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Molecular signatures defining quiescence in muscle satellite cells (mSCs) remain enigmatic. In this issue of Developmental Cell, Yue et al. adapted an in vivo fixation approach to isolate dormant mSCs from healthy muscle. Characterizing the transcriptome from these cells, they identified intron retention as a novel hallmark of mSC quiescence.
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Affiliation(s)
- Kiran Nakka
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Radmila Kovac
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Matthew Man-Kin Wong
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - F Jeffrey Dilworth
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; LIFE Research Institute, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
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11
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Syal C, Kosaraju J, Hamilton L, Aumont A, Chu A, Sarma SN, Thomas J, Seegobin M, Dilworth FJ, He L, Wondisford FE, Zimmermann R, Parent M, Fernandes K, Wang J. Dysregulated expression of monoacylglycerol lipase is a marker for anti-diabetic drug metformin-targeted therapy to correct impaired neurogenesis and spatial memory in Alzheimer's disease. Am J Cancer Res 2020; 10:6337-6360. [PMID: 32483456 PMCID: PMC7255032 DOI: 10.7150/thno.44962] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 04/28/2020] [Indexed: 12/17/2022] Open
Abstract
Rationale: Monoacylglycerol lipase (Mgll), a hydrolase that breaks down the endocannabinoid 2-arachidonoyl glycerol (2-AG) to produce arachidonic acid (ARA), is a potential target for neurodegenerative diseases, such as Alzheimer's disease (AD). Increasing evidence shows that impairment of adult neurogenesis by perturbed lipid metabolism predisposes patients to AD. However, it remains unknown what causes aberrant expression of Mgll in AD and how Mgll-regulated lipid metabolism impacts adult neurogenesis, thus predisposing to AD during aging. Here, we identify Mgll as an aging-induced factor that impairs adult neurogenesis and spatial memory in AD, and show that metformin, an FDA-approved anti-diabetic drug, can reduce the expression of Mgll to reverse impaired adult neurogenesis, prevent spatial memory decline and reduce β-amyloid accumulation. Methods: Mgll expression was assessed in both human AD patient post-mortem hippocampal tissues and 3xTg-AD mouse model. In addition, we used both the 3xTg-AD animal model and the CbpS436A genetic knock-in mouse model to identify that elevated Mgll expression is caused by the attenuation of the aPKC-CBP pathway, involving atypical protein kinase C (aPKC)-stimulated Ser436 phosphorylation of histone acetyltransferase CBP through biochemical methods. Furthermore, we performed in vivo adult neurogenesis assay with BrdU/EdU labelling and Morris water maze task in both animal models following pharmacological treatments to show the key role of Mgll in metformin-corrected neurogenesis and spatial memory deficits of AD through reactivating the aPKC-CBP pathway. Finally, we performed in vitro adult neurosphere assays using both animal models to study the role of the aPKC-CBP mediated Mgll repression in determining adult neural stem/progenitor cell (NPC) fate. Results: Here, we demonstrate that aging-dependent induction of Mgll is observed in the 3xTg-AD model and human AD patient post-mortem hippocampal tissues. Importantly, we discover that elevated Mgll expression is caused by the attenuation of the aPKC-CBP pathway. The accumulation of Mgll in the 3xTg-AD mice reduces the genesis of newborn neurons and perturbs spatial memory. However, we find that metformin-stimulated aPKC-CBP pathway decreases Mgll expression to recover these deficits in 3xTg-AD. In addition, we reveal that elevated Mgll levels in cultured adult NPCs from both 3xTg-AD and CbpS436A animal models are responsible for their NPC neuronal differentiation deficits. Conclusion: Our findings set the stage for development of a clinical protocol where Mgll would serve as a biomarker in early stages of AD to identify potential metformin-responsive AD patients to restore their neurogenesis and spatial memory.
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12
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Campbell TM, Lapner P, Dilworth FJ, Sheikh MA, Laneuville O, Uhthoff H, Trudel G. Tendon contains more stem cells than bone at the rotator cuff repair site. J Shoulder Elbow Surg 2019; 28:1779-1787. [PMID: 31036422 DOI: 10.1016/j.jse.2019.02.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 02/06/2019] [Accepted: 02/15/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND The rotator cuff (RC) repair failure rate is high. Tendon and bone represent sources of mesenchymal stem cells (MSCs), but the number of MSCs from each has not been compared. Bone channeling may increase bone-derived MSC numbers participating in enthesis re-formation at the "footprint" repair site. The effect of preoperative channeling on increasing bone MSC numbers has never been reported. We asked (1) whether bone contains more MSCs than tendon at the time of arthroscopic repair and (2) whether bone preoperative channeling at the RC repair site increases the number of bone-derived MSCs at the time of surgery. METHODS In 23 participants undergoing arthroscopic RC repair, bone was sampled from the footprint and tendon was sampled from the distal supraspinatus. We randomized participants to the channeling or no-channeling group 5 to 7 days before surgery. We enumerated MSCs from both tissues using the colony-forming unit-fibroblast (CFU-F) assay (10 per group). We identified MSC identity using flow cytometry and MSC tri-differentiation capacity (n = 3). RESULTS Tendon CFU-F per gram exceeded bone CFU-F per gram for both groups (479 ± 173 CFU-F/g vs. 162 ± 54 CFU-F/g for channeling [P = .036] and 1334 ± 393 CFU-F/g vs. 284 ± 88 CFU-F/g for no channeling [P = .009]). Ninety-nine percent of cultured cells satisfied the MSC definition criteria. CONCLUSIONS The distal supraspinatus tendon contained more MSCs per gram than the humeral footprint. Tendon may represent an important and overlooked MSC source for postoperative enthesis re-formation. Further studies are needed to evaluate the repair role of tendon MSCs and to recommend bone channeling in RC repair.
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Affiliation(s)
- T Mark Campbell
- Department of Physical Medicine and Rehabilitation, Elisabeth Bruyère Hospital, Ottawa, ON, Canada; Department of Medicine, Division of Physical and Rehabilitation Medicine, The Ottawa Hospital, Ottawa, ON, Canada.
| | - Peter Lapner
- Department of Surgery, Division of Orthopedic Surgery, The Ottawa Hospital, Ottawa, ON, Canada
| | - F Jeffrey Dilworth
- Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - M Adnan Sheikh
- Department of Radiology, Division of Musculoskeletal Imaging, The Ottawa Hospital, Ottawa, ON, Canada
| | | | - Hans Uhthoff
- The Bone and Joint Research Laboratory, University of Ottawa, Ottawa, ON, Canada
| | - Guy Trudel
- Department of Medicine, Division of Physical and Rehabilitation Medicine, The Ottawa Hospital, Ottawa, ON, Canada
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13
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Abstract
Stem cells are continuously challenged with the decision to either self-renew or adopt a new fate. Self-renewal is regulated by a system of cellular memory, which must be bypassed for differentiation. Previous studies have identified Polycomb group (PcG) and Trithorax group (TrxG) proteins as key modulators of cellular memory. In this Perspective, we draw from embryonic and adult stem cell studies to discuss the complex roles played by PcG and TrxG in maintaining cell identity while allowing for microenvironment-mediated alterations in cell fate. Finally, we discuss the potential for targeting these proteins as a therapeutic approach in cancer.
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Affiliation(s)
- Marjorie Brand
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON, Canada K1H 8L6; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8L6.
| | - Kiran Nakka
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON, Canada K1H 8L6; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8L6
| | - Jiayu Zhu
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON, Canada K1H 8L6; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8L6
| | - F Jeffrey Dilworth
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON, Canada K1H 8L6; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8L6.
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14
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Maganti HB, Jrade H, Cafariello C, Manias Rothberg JL, Porter CJ, Yockell-Lelièvre J, Battaion HL, Khan ST, Howard JP, Li Y, Grzybowski AT, Sabri E, Ruthenburg AJ, Dilworth FJ, Perkins TJ, Sabloff M, Ito CY, Stanford WL. Targeting the MTF2-MDM2 Axis Sensitizes Refractory Acute Myeloid Leukemia to Chemotherapy. Cancer Discov 2018; 8:1376-1389. [PMID: 30115703 DOI: 10.1158/2159-8290.cd-17-0841] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 02/21/2018] [Accepted: 08/13/2018] [Indexed: 12/14/2022]
Abstract
Deep sequencing has revealed that epigenetic modifiers are the most mutated genes in acute myeloid leukemia (AML). Thus, elucidating epigenetic dysregulation in AML is crucial to understand disease mechanisms. Here, we demonstrate that metal response element binding transcription factor 2/polycomblike 2 (MTF2/PCL2) plays a fundamental role in the polycomb repressive complex 2 (PRC2) and that its loss elicits an altered epigenetic state underlying refractory AML. Unbiased systems analyses identified the loss of MTF2-PRC2 repression of MDM2 as central to, and therefore a biomarker for, refractory AML. Thus, immature MTF2-deficient CD34+CD38- cells overexpress MDM2, thereby inhibiting p53 that leads to chemoresistance due to defects in cell-cycle regulation and apoptosis. Targeting this dysregulated signaling pathway by MTF2 overexpression or MDM2 inhibitors sensitized refractory patient leukemic cells to induction chemotherapeutics and prevented relapse in AML patient-derived xenograft mice. Therefore, we have uncovered a direct epigenetic mechanism by which MTF2 functions as a tumor suppressor required for AML chemotherapeutic sensitivity and identified a potential therapeutic strategy to treat refractory AML.Significance: MTF2 deficiency predicts refractory AML at diagnosis. MTF2 represses MDM2 in hematopoietic cells and its loss in AML results in chemoresistance. Inhibiting p53 degradation by overexpressing MTF2 in vitro or by using MDM2 inhibitors in vivo sensitizes MTF2-deficient refractory AML cells to a standard induction-chemotherapy regimen. Cancer Discov; 8(11); 1376-89. ©2018 AACR. See related commentary by Duy and Melnick, p. 1348 This article is highlighted in the In This Issue feature, p. 1333.
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Affiliation(s)
- Harinad B Maganti
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Hani Jrade
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Christopher Cafariello
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Janet L Manias Rothberg
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Christopher J Porter
- Ottawa Bioinformatics Core Facility, The Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Julien Yockell-Lelièvre
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
| | - Hannah L Battaion
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Safwat T Khan
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Joel P Howard
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Yuefeng Li
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Adrian T Grzybowski
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois
| | - Elham Sabri
- Clinical Epidemiology Methods Centre, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Alexander J Ruthenburg
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois
| | - F Jeffrey Dilworth
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Theodore J Perkins
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada.,Ottawa Bioinformatics Core Facility, The Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Mitchell Sabloff
- Division of Hematology, Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada.,Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Caryn Y Ito
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada. .,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - William L Stanford
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada. .,Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
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15
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Abstract
Background Skeletal muscles express a highly specialized proteome that allows the metabolism of energy sources to mediate myofiber contraction. This muscle-specific proteome is partially derived through the muscle-specific transcription of a subset of genes. Surprisingly, RNA sequencing technologies have also revealed a significant role for muscle-specific alternative splicing in generating protein isoforms that give specialized function to the muscle proteome. Main body In this review, we discuss the current knowledge with respect to the mechanisms that allow pre-mRNA transcripts to undergo muscle-specific alternative splicing while identifying some of the key trans-acting splicing factors essential to the process. The importance of specific splicing events to specialized muscle function is presented along with examples in which dysregulated splicing contributes to myopathies. Though there is now an appreciation that alternative splicing is a major contributor to proteome diversification, the emergence of improved “targeted” proteomic methodologies for detection of specific protein isoforms will soon allow us to better appreciate the extent to which alternative splicing modifies the activity of proteins (and their ability to interact with other proteins) in the skeletal muscle. In addition, we highlight a continued need to better explore the signaling pathways that contribute to the temporal control of trans-acting splicing factor activity to ensure specific protein isoforms are expressed in the proper cellular context. Conclusions An understanding of the signal-dependent and signal-independent events driving muscle-specific alternative splicing has the potential to provide us with novel therapeutic strategies to treat different myopathies. Electronic supplementary material The online version of this article (10.1186/s13395-018-0152-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kiran Nakka
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada
| | - Claudia Ghigna
- Istituto di Genetica Molecolare-Consiglio Nazionale delle Ricerche (IGM-CNR), Pavia, Italy
| | - Davide Gabellini
- Unit of Gene Expression and Muscular Dystrophy, Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, DIBIT2, 5A3-44, via Olgettina 58, 20132, Milan, Italy.
| | - F Jeffrey Dilworth
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada. .,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada. .,Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, 501 Smyth Rd, Mailbox 511, Ottawa, ON, K1H 8L6, Canada.
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16
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Affiliation(s)
- Marjorie Brand
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada, and the Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - F Jeffrey Dilworth
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada, and the Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
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17
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Fazio EN, Young CC, Toma J, Levy M, Berger KR, Johnson CL, Mehmood R, Swan P, Chu A, Cregan SP, Dilworth FJ, Howlett CJ, Pin CL. Activating transcription factor 3 promotes loss of the acinar cell phenotype in response to cerulein-induced pancreatitis in mice. Mol Biol Cell 2017; 28:2347-2359. [PMID: 28701342 PMCID: PMC5576899 DOI: 10.1091/mbc.e17-04-0254] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/22/2017] [Accepted: 06/27/2017] [Indexed: 12/20/2022] Open
Abstract
Pancreatitis is a debilitating disease of the exocrine pancreas that, under chronic conditions, is a major susceptibility factor for pancreatic ductal adenocarcinoma (PDAC). Although down-regulation of genes that promote the mature acinar cell fate is required to reduce injury associated with pancreatitis, the factors that promote this repression are unknown. Activating transcription factor 3 (ATF3) is a key mediator of the unfolded protein response, a pathway rapidly activated during pancreatic insult. Using chromatin immunoprecipitation followed by next-generation sequencing, we show that ATF3 is bound to the transcriptional regulatory regions of >30% of differentially expressed genes during the initiation of pancreatitis. Of importance, ATF3-dependent regulation of these genes was observed only upon induction of pancreatitis, with pathways involved in inflammation, acinar cell differentiation, and cell junctions being specifically targeted. Characterizing expression of transcription factors that affect acinar cell differentiation suggested that acinar cells lacking ATF3 maintain a mature cell phenotype during pancreatitis, a finding supported by maintenance of junctional proteins and polarity markers. As a result, Atf3-/- pancreatic tissue displayed increased tissue damage and inflammatory cell infiltration at early time points during injury but, at later time points, showed reduced acinar-to-duct cell metaplasia. Thus our results reveal a critical role for ATF3 as a key regulator of the acinar cell transcriptional response during injury and may provide a link between chronic pancreatitis and PDAC.
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Affiliation(s)
- Elena N Fazio
- Children's Health Research Institute, London, ON N6C 2V5, Canada
- Department of Paediatrics, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Oncology, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Claire C Young
- Children's Health Research Institute, London, ON N6C 2V5, Canada
- Department of Paediatrics, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Jelena Toma
- Children's Health Research Institute, London, ON N6C 2V5, Canada
- Department of Paediatrics, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Michael Levy
- Children's Health Research Institute, London, ON N6C 2V5, Canada
| | - Kurt R Berger
- Children's Health Research Institute, London, ON N6C 2V5, Canada
- Department of Paediatrics, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Charis L Johnson
- Children's Health Research Institute, London, ON N6C 2V5, Canada
- Department of Paediatrics, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Rashid Mehmood
- Children's Health Research Institute, London, ON N6C 2V5, Canada
- Department of Paediatrics, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Patrick Swan
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 3K7, Canada
- Robarts Research Institute, University of Western Ontario, London, ON N6A 5B7, Canada
| | - Alphonse Chu
- Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Sean P Cregan
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 3K7, Canada
- Robarts Research Institute, University of Western Ontario, London, ON N6A 5B7, Canada
| | - F Jeffrey Dilworth
- Department of Pathology and Laboratory Medicine, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Christopher J Howlett
- Department of Pathology and Laboratory Medicine, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Christopher L Pin
- Children's Health Research Institute, London, ON N6C 2V5, Canada
- Department of Paediatrics, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Oncology, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 3K7, Canada
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18
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Chen Z, Chang WY, Etheridge A, Strickfaden H, Jin Z, Palidwor G, Cho JH, Wang K, Kwon SY, Doré C, Raymond A, Hotta A, Ellis J, Kandel RA, Dilworth FJ, Perkins TJ, Hendzel MJ, Galas DJ, Stanford WL. Reprogramming progeria fibroblasts re-establishes a normal epigenetic landscape. Aging Cell 2017; 16:870-887. [PMID: 28597562 PMCID: PMC5506428 DOI: 10.1111/acel.12621] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2017] [Indexed: 12/14/2022] Open
Abstract
Ideally, disease modeling using patient‐derived induced pluripotent stem cells (iPSCs) enables analysis of disease initiation and progression. This requires any pathological features of the patient cells used for reprogramming to be eliminated during iPSC generation. Hutchinson–Gilford progeria syndrome (HGPS) is a segmental premature aging disorder caused by the accumulation of the truncated form of Lamin A known as Progerin within the nuclear lamina. Cellular hallmarks of HGPS include nuclear blebbing, loss of peripheral heterochromatin, defective epigenetic inheritance, altered gene expression, and senescence. To model HGPS using iPSCs, detailed genome‐wide and structural analysis of the epigenetic landscape is required to assess the initiation and progression of the disease. We generated a library of iPSC lines from fibroblasts of patients with HGPS and controls, including one family trio. HGPS patient‐derived iPSCs are nearly indistinguishable from controls in terms of pluripotency, nuclear membrane integrity, as well as transcriptional and epigenetic profiles, and can differentiate into affected cell lineages recapitulating disease progression, despite the nuclear aberrations, altered gene expression, and epigenetic landscape inherent to the donor fibroblasts. These analyses demonstrate the power of iPSC reprogramming to reset the epigenetic landscape to a revitalized pluripotent state in the face of widespread epigenetic defects, validating their use to model the initiation and progression of disease in affected cell lineages.
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Affiliation(s)
- Zhaoyi Chen
- The Sprott Centre for Stem Cell Research; Regenerative Medicine Program; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa Ontario Canada
| | - Wing Y. Chang
- The Sprott Centre for Stem Cell Research; Regenerative Medicine Program; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
| | - Alton Etheridge
- Pacific Northwest Diabetes Research Institute; 720 Broadway Seattle WA 98103 USA
| | - Hilmar Strickfaden
- Cross Cancer Institute and the Department of Experimental Oncology; Faculty of Medicine and Dentistry; University of Alberta; Edmonton Alberta Canada T6G 1Z2
| | - Zhigang Jin
- Cross Cancer Institute and the Department of Experimental Oncology; Faculty of Medicine and Dentistry; University of Alberta; Edmonton Alberta Canada T6G 1Z2
| | - Gareth Palidwor
- The Sprott Centre for Stem Cell Research; Regenerative Medicine Program; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
- Ottawa Bioinformatics Core Facility; The Sprott Centre for Stem Cell Research; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
| | - Ji-Hoon Cho
- Pacific Northwest Diabetes Research Institute; 720 Broadway Seattle WA 98103 USA
| | - Kai Wang
- Pacific Northwest Diabetes Research Institute; 720 Broadway Seattle WA 98103 USA
| | - Sarah Y. Kwon
- The Sprott Centre for Stem Cell Research; Regenerative Medicine Program; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
- Department of Chemical Engineering; University of Toronto; Toronto Ontario Canada
| | - Carole Doré
- The Sprott Centre for Stem Cell Research; Regenerative Medicine Program; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
| | - Angela Raymond
- The Sprott Centre for Stem Cell Research; Regenerative Medicine Program; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
| | - Akitsu Hotta
- Center for iPS Cell Research and Application (CiRA); Kyoto University; Kyoto Japan
| | - James Ellis
- Program in Developmental and Stem Cell Biology; The Hospital for Sick Children; Toronto Ontario Canada
- Department of Molecular Genetics; University of Toronto; Toronto Ontario Canada
| | - Rita A. Kandel
- Pathology and Experimental Medicine; Mount Sinai Hospital; Toronto Ontario Canada
| | - F. Jeffrey Dilworth
- The Sprott Centre for Stem Cell Research; Regenerative Medicine Program; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa Ontario Canada
- Ottawa Institute of Systems Biology; Ottawa Ontario Canada
| | - Theodore J. Perkins
- The Sprott Centre for Stem Cell Research; Regenerative Medicine Program; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
- Ottawa Bioinformatics Core Facility; The Sprott Centre for Stem Cell Research; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
- Ottawa Institute of Systems Biology; Ottawa Ontario Canada
| | - Michael J. Hendzel
- Cross Cancer Institute and the Department of Experimental Oncology; Faculty of Medicine and Dentistry; University of Alberta; Edmonton Alberta Canada T6G 1Z2
| | - David J. Galas
- Pacific Northwest Diabetes Research Institute; 720 Broadway Seattle WA 98103 USA
| | - William L. Stanford
- The Sprott Centre for Stem Cell Research; Regenerative Medicine Program; Ottawa Hospital Research Institute; Ottawa Ontario Canada K1H 8L6
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa Ontario Canada
- Department of Chemical Engineering; University of Toronto; Toronto Ontario Canada
- Department of Biochemistry, Microbiology and Immunology; University of Ottawa; Ottawa Ontario Canada
- Ottawa Institute of Systems Biology; Ottawa Ontario Canada
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19
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Casa V, Runfola V, Micheloni S, Aziz A, Dilworth FJ, Gabellini D. Polycomb repressive complex 1 provides a molecular explanation for repeat copy number dependency in FSHD muscular dystrophy. Hum Mol Genet 2017; 26:753-767. [PMID: 28040729 PMCID: PMC5409123 DOI: 10.1093/hmg/ddw426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/15/2016] [Indexed: 11/13/2022] Open
Abstract
Repression of repetitive elements is crucial to preserve genome integrity and has been traditionally ascribed to constitutive heterochromatin pathways. FacioScapuloHumeral Muscular Dystrophy (FSHD), one of the most common myopathies, is characterized by a complex interplay of genetic and epigenetic events. The main FSHD form is linked to a reduced copy number of the D4Z4 macrosatellite repeat on 4q35, causing loss of silencing and aberrant expression of the D4Z4-embedded DUX4 gene leading to disease. By an unknown mechanism, D4Z4 copy-number correlates with FSHD phenotype. Here we show that the DUX4 proximal promoter (DUX4p) is sufficient to nucleate the enrichment of both constitutive and facultative heterochromatin components and to mediate a copy-number dependent gene silencing. We found that both the CpG/GC dense DNA content and the repetitive nature of DUX4p arrays are important for their repressive ability. We showed that DUX4p mediates a copy number-dependent Polycomb Repressive Complex 1 (PRC1) recruitment, which is responsible for the copy-number dependent gene repression. Overall, we directly link genetic and epigenetic defects in FSHD by proposing a novel molecular explanation for the copy number-dependency in FSHD pathogenesis, and offer insight into the molecular functions of repeats in chromatin regulation.
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Affiliation(s)
- Valentina Casa
- Gene Expression and Muscular Dystrophy Unit, Division of Regenerative Medicine, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy.,Università Vita-Salute San Raffaele, Milan 20132, Italy
| | - Valeria Runfola
- Gene Expression and Muscular Dystrophy Unit, Division of Regenerative Medicine, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
| | - Stefano Micheloni
- Gene Expression and Muscular Dystrophy Unit, Division of Regenerative Medicine, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
| | - Arif Aziz
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1Y 4E9, Canada
| | - F Jeffrey Dilworth
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1Y 4E9, Canada
| | - Davide Gabellini
- Gene Expression and Muscular Dystrophy Unit, Division of Regenerative Medicine, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy.,Dulbecco Telethon Institute, Milan 20132, Italy
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20
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Abstract
Satellite cells comprise a pool of quiescent stem cells that repair muscle damage, but the mechanisms enforcing their quiescence are poorly defined. In this issue of Cell Stem Cell, Boonsanay et al. (2016) show that the histone methyltransferase Suv4-20H1 maintains satellite cell quiescence by promoting a heterochromatic state through transcriptional repression of the myogenic master regulator MyoD.
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Affiliation(s)
- Yuefeng Li
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - F Jeffrey Dilworth
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada.
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21
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Benyoucef A, Palii CG, Wang C, Porter CJ, Chu A, Dai F, Tremblay V, Rakopoulos P, Singh K, Huang S, Pflumio F, Hébert J, Couture JF, Perkins TJ, Ge K, Dilworth FJ, Brand M. UTX inhibition as selective epigenetic therapy against TAL1-driven T-cell acute lymphoblastic leukemia. Genes Dev 2016; 30:508-21. [PMID: 26944678 PMCID: PMC4782046 DOI: 10.1101/gad.276790.115] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Benyoucef et al. reveal the existence of a subtype-specific epigenetic vulnerability in T-cell acute lymphoblastic leukemia (T-ALL) by which a particular subgroup of T-ALL characterized by expression of the oncogenic transcription factor TAL1 is uniquely sensitive to variations in the dosage and activity of the histone 3 Lys27 (H3K27) demethylase UTX/KDM6A. T-cell acute lymphoblastic leukemia (T-ALL) is a heterogeneous group of hematological tumors composed of distinct subtypes that vary in their genetic abnormalities, gene expression signatures, and prognoses. However, it remains unclear whether T-ALL subtypes differ at the functional level, and, as such, T-ALL treatments are uniformly applied across subtypes, leading to variable responses between patients. Here we reveal the existence of a subtype-specific epigenetic vulnerability in T-ALL by which a particular subgroup of T-ALL characterized by expression of the oncogenic transcription factor TAL1 is uniquely sensitive to variations in the dosage and activity of the histone 3 Lys27 (H3K27) demethylase UTX/KDM6A. Specifically, we identify UTX as a coactivator of TAL1 and show that it acts as a major regulator of the TAL1 leukemic gene expression program. Furthermore, we demonstrate that UTX, previously described as a tumor suppressor in T-ALL, is in fact a pro-oncogenic cofactor essential for leukemia maintenance in TAL1-positive (but not TAL1-negative) T-ALL. Exploiting this subtype-specific epigenetic vulnerability, we propose a novel therapeutic approach based on UTX inhibition through in vivo administration of an H3K27 demethylase inhibitor that efficiently kills TAL1-positive primary human leukemia. These findings provide the first opportunity to develop personalized epigenetic therapy for T-ALL patients.
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Affiliation(s)
- Aissa Benyoucef
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8L6, Canada; Ottawa Institute for Systems Biology, Ottawa, Ontario K1H 8L6, Canada
| | - Carmen G Palii
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Ottawa Institute for Systems Biology, Ottawa, Ontario K1H 8L6, Canada
| | - Chaochen Wang
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Christopher J Porter
- Ottawa Bioinformatics Core Facility, The Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Alphonse Chu
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Fengtao Dai
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Véronique Tremblay
- Ottawa Institute for Systems Biology, Ottawa, Ontario K1H 8L6, Canada; Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Patricia Rakopoulos
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Kulwant Singh
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Ottawa Institute for Systems Biology, Ottawa, Ontario K1H 8L6, Canada
| | - Suming Huang
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida 32610, USA
| | - Francoise Pflumio
- Commissariat á l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant (DSV)-Institut de Recherche en Radiobiologie Cellulaire et Moléculaire (IRCM)-Stem Cells and Radiation Department (SCSR)-Laboratory of Hematopoietic Stem Cells and Leukemia (LSHL), U967, Fontenay-aux-Roses 92265, Paris, France; Institut National de la Santé et de la Recherche Médicale, U967, Fontenay-aux-Roses 92265, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Université Paris-Sud, UMR 967, Fontenay-aux-Roses 92265, Paris, France
| | - Josée Hébert
- Institute of Research in Immunology and Cancer, University of Montreal, Montreal, Quebec H3C 3J7, Canada; Maisonneuve-Rosemont Hospital, Montreal, Quebec H1T 2M4, Canada
| | - Jean-Francois Couture
- Ottawa Institute for Systems Biology, Ottawa, Ontario K1H 8L6, Canada; Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Theodore J Perkins
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Ottawa Bioinformatics Core Facility, The Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Kai Ge
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - F Jeffrey Dilworth
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8L6, Canada; Ottawa Institute for Systems Biology, Ottawa, Ontario K1H 8L6, Canada
| | - Marjorie Brand
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8L6, Canada; Ottawa Institute for Systems Biology, Ottawa, Ontario K1H 8L6, Canada
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22
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Faralli H, Wang C, Nakka K, Benyoucef A, Sebastian S, Zhuang L, Chu A, Palii CG, Liu C, Camellato B, Brand M, Ge K, Dilworth FJ. UTX demethylase activity is required for satellite cell-mediated muscle regeneration. J Clin Invest 2016; 126:1555-65. [PMID: 26999603 DOI: 10.1172/jci83239] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 01/07/2016] [Indexed: 12/31/2022] Open
Abstract
The X chromosome-encoded histone demethylase UTX (also known as KDM6A) mediates removal of repressive trimethylation of histone H3 lysine 27 (H3K27me3) to establish transcriptionally permissive chromatin. Loss of UTX in female mice is embryonic lethal. Unexpectedly, male UTX-null mice escape embryonic lethality due to expression of UTY, a paralog that lacks H3K27 demethylase activity, suggesting an enzyme-independent role for UTX in development and thereby challenging the need for active H3K27 demethylation in vivo. However, the requirement for active H3K27 demethylation in stem cell-mediated tissue regeneration remains untested. Here, we employed an inducible mouse KO that specifically ablates Utx in satellite cells (SCs) and demonstrated that active H3K27 demethylation is necessary for muscle regeneration. Loss of UTX in SCs blocked myofiber regeneration in both male and female mice. Furthermore, we demonstrated that UTX mediates muscle regeneration through its H3K27 demethylase activity, as loss of demethylase activity either by chemical inhibition or knock-in of demethylase-dead UTX resulted in defective muscle repair. Mechanistically, dissection of the muscle regenerative process revealed that the demethylase activity of UTX is required for expression of the transcription factor myogenin, which in turn drives differentiation of muscle progenitors. Thus, we have identified a critical role for the enzymatic activity of UTX in activating muscle-specific gene expression during myofiber regeneration and have revealed a physiological role for active H3K27 demethylation in vivo.
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23
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Segalés J, Islam ABMMK, Kumar R, Liu QC, Sousa-Victor P, Dilworth FJ, Ballestar E, Perdiguero E, Muñoz-Cánoves P. Chromatin-wide and transcriptome profiling integration uncovers p38α MAPK as a global regulator of skeletal muscle differentiation. Skelet Muscle 2016; 6:9. [PMID: 26981231 PMCID: PMC4791895 DOI: 10.1186/s13395-016-0074-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 01/05/2016] [Indexed: 11/23/2022] Open
Abstract
Background Extracellular stimuli induce gene expression responses through intracellular signaling mediators. The p38 signaling pathway is a paradigm of the mitogen-activated protein kinase (MAPK) family that, although originally identified as stress-response mediator, contributes to establishing stem cell differentiation fates. p38α is central for induction of the differentiation fate of the skeletal muscle stem cells (satellite cells) through not fully characterized mechanisms. Methods To investigate the global gene transcription program regulated by p38α during satellite cell differentiation (myogenesis), and to specifically address whether this regulation occurs through direct action of p38α on gene promoters, we performed a combination of microarray gene expression and genome-wide binding analyses. For experimental robustness, two myogenic cellular systems with genetic and chemical loss of p38α function were used: (1) satellite cells derived from mice with muscle-specific deletion of p38α, and (2) the C2C12 murine myoblast cell line cultured in the absence or presence of the p38α/β inhibitor SB203580. Analyses were performed at cell proliferation and early differentiation stages. Results We show that p38α binds to a large set of active promoters during the transition of myoblasts from proliferation to differentiation stages. p38α-bound promoters are enriched with binding motifs for several transcription factors, with Sp1, Tcf3/E47, Lef1, FoxO4, MyoD, and NFATc standing out in all experimental conditions. p38α association with chromatin correlates very well with high levels of transcription, in agreement with its classical function as an activator of myogenic differentiation. Interestingly, p38α also associates with genes repressed at the onset of differentiation, thus highlighting the relevance of p38-dependent chromatin regulation for transcriptional activation and repression during myogenesis. Conclusions These results uncover p38α association and function on chromatin at novel classes of target genes during skeletal muscle cell differentiation. This is consistent with this MAPK isoform being a transcriptional regulator. Electronic supplementary material The online version of this article (doi:10.1186/s13395-016-0074-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jessica Segalés
- Department of Experimental and Health Sciences, Pompeu Fabra University (UPF), CIBER on Neurodegenerative diseases (CIBERNED), Barcelona, Spain
| | - Abul B M M K Islam
- Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, 1000 Bangladesh
| | - Roshan Kumar
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115 USA
| | - Qi-Cai Liu
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6 Canada
| | - Pedro Sousa-Victor
- Department of Experimental and Health Sciences, Pompeu Fabra University (UPF), CIBER on Neurodegenerative diseases (CIBERNED), Barcelona, Spain ; Present address: Buck Institute for Research on Aging, Novato, CA USA
| | - F Jeffrey Dilworth
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6 Canada
| | - Esteban Ballestar
- Chromatin and Disease Group, Cancer Epigenetics and Biology Programme (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Eusebio Perdiguero
- Department of Experimental and Health Sciences, Pompeu Fabra University (UPF), CIBER on Neurodegenerative diseases (CIBERNED), Barcelona, Spain
| | - Pura Muñoz-Cánoves
- Department of Experimental and Health Sciences, Pompeu Fabra University (UPF), CIBER on Neurodegenerative diseases (CIBERNED), Barcelona, Spain ; Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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24
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Al-Khalaf MH, Blake LE, Larsen BD, Bell RA, Brunette S, Parks RJ, Rudnicki MA, McKinnon PJ, Jeffrey Dilworth F, Megeney LA. Temporal activation of XRCC1-mediated DNA repair is essential for muscle differentiation. Cell Discov 2016; 2:15041. [PMID: 27462438 PMCID: PMC4860966 DOI: 10.1038/celldisc.2015.41] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/28/2015] [Indexed: 01/04/2023] Open
Abstract
Transient DNA strand break formation has been identified as an effective means to enhance gene expression in living cells. In the muscle lineage, cell differentiation is contingent upon the induction of caspase-mediated DNA strand breaks, which act to establish the terminal gene expression program. This coordinated DNA nicking is rapidly resolved, suggesting that myoblasts may deploy DNA repair machinery to stabilize the genome and entrench the differentiated phenotype. Here, we identify the base excision repair pathway component XRCC1 as an indispensable mediator of muscle differentiation. Caspase-triggered XRCC1 repair foci form rapidly within differentiating myonuclei, and then dissipate as the maturation program proceeds. Skeletal myoblast deletion of Xrcc1 does not have an impact on cell growth, yet leads to perinatal lethality, with sustained DNA damage and impaired myofiber development. Together, these results demonstrate that XRCC1 manages a temporally responsive DNA repair process to advance the muscle differentiation program.
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Affiliation(s)
- Mohammad H Al-Khalaf
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Leanne E Blake
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, The Ottawa Hospital , Ottawa, ON, Canada
| | - Brian D Larsen
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Ryan A Bell
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, The Ottawa Hospital , Ottawa, ON, Canada
| | - Steve Brunette
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, The Ottawa Hospital , Ottawa, ON, Canada
| | - Robin J Parks
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Michael A Rudnicki
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Peter J McKinnon
- Department of Genetics, St Jude Children's Research Hospital , Memphis, TN, USA
| | - F Jeffrey Dilworth
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Lynn A Megeney
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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25
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Singh K, Cassano M, Planet E, Sebastian S, Jang SM, Sohi G, Faralli H, Choi J, Youn HD, Dilworth FJ, Trono D. A KAP1 phosphorylation switch controls MyoD function during skeletal muscle differentiation. Genes Dev 2015; 29:513-25. [PMID: 25737281 PMCID: PMC4358404 DOI: 10.1101/gad.254532.114] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The transcriptional activator MyoD serves as a master controller of myogenesis. Singh et al. identify KAP1/TRIM28 as a key regulator of MyoD function. In myoblasts, KAP1 is present with MyoD and Mef2 at many muscle genes, where it acts as a scaffold to recruit not only coactivators such as p300 and LSD1 but also corepressors such as G9a and HDAC1, with promoter silencing as the net outcome. Upon differentiation, MSK1-mediated phosphorylation of KAP1 releases the corepressors from the scaffold, unleashing transcriptional activation by MyoD/Mef2 and their positive cofactors. The transcriptional activator MyoD serves as a master controller of myogenesis. Often in partnership with Mef2 (myocyte enhancer factor 2), MyoD binds to the promoters of hundreds of muscle genes in proliferating myoblasts yet activates these targets only upon receiving cues that launch differentiation. What regulates this off/on switch of MyoD function has been incompletely understood, although it is known to reflect the action of chromatin modifiers. Here, we identify KAP1 (KRAB [Krüppel-like associated box]-associated protein 1)/TRIM28 (tripartite motif protein 28) as a key regulator of MyoD function. In myoblasts, KAP1 is present with MyoD and Mef2 at many muscle genes, where it acts as a scaffold to recruit not only coactivators such as p300 and LSD1 but also corepressors such as G9a and HDAC1 (histone deacetylase 1), with promoter silencing as the net outcome. Upon differentiation, MSK1-mediated phosphorylation of KAP1 releases the corepressors from the scaffold, unleashing transcriptional activation by MyoD/Mef2 and their positive cofactors. Thus, our results reveal KAP1 as a previously unappreciated interpreter of cell signaling, which modulates the ability of MyoD to drive myogenesis.
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Affiliation(s)
- Kulwant Singh
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Marco Cassano
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Evarist Planet
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Soji Sebastian
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Suk Min Jang
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Gurjeev Sohi
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Hervé Faralli
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Jinmi Choi
- Department of Biomedical Sciences and Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 110-799, Korea
| | - Hong-Duk Youn
- Department of Biomedical Sciences and Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 110-799, Korea
| | - F Jeffrey Dilworth
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ontario K1H 8L6, Canada
| | - Didier Trono
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland;
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26
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Runfola V, Sebastian S, Dilworth FJ, Gabellini D. Rbfox proteins regulate tissue-specific alternative splicing of Mef2D required for muscle differentiation. J Cell Sci 2015; 128:631-7. [PMID: 25609712 DOI: 10.1242/jcs.161059] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Among the Mef2 family of transcription factors, Mef2D is unique in that it undergoes tissue-specific splicing to generate an isoform that is essential for muscle differentiation. However, the mechanisms mediating this muscle-specific processing of Mef2D remain unknown. Using bioinformatics, we identified Rbfox proteins as putative modulators of Mef2D muscle-specific splicing. Accordingly, we found direct and specific Rbfox1 and Rbfox2 binding to Mef2D pre-mRNA in vivo. Gain- and loss-of-function experiments demonstrated that Rbfox1 and Rbfox2 cooperate in promoting Mef2D splicing and subsequent myogenesis. Thus, our findings reveal a new role for Rbfox proteins in regulating myogenesis through activation of essential muscle-specific splicing events.
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Affiliation(s)
- Valeria Runfola
- Dulbecco Telethon Institute and Division of Regenerative Medicine, San Raffaele Scientific Institute, 20132 Milan, Italy Università Vita-Salute San Raffaele, 20132 Milan, Italy
| | - Soji Sebastian
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1Y 4E9, Canada
| | - F Jeffrey Dilworth
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1Y 4E9, Canada
| | - Davide Gabellini
- Dulbecco Telethon Institute and Division of Regenerative Medicine, San Raffaele Scientific Institute, 20132 Milan, Italy
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27
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Abstract
Faralli and Dillworth discuss the study by Saccone et al. (in this issue of Genes & Development) on the role of muscle-specific microRNAs (myomiRs) as HDAC-repressed regulators of chromatin remodeling and skeletal myogenesis in a mouse model of Duchenne muscular dystrophy. Fibro-adipogenic progenitors (FAPs) reside in the muscle, where they facilitate myofiber regeneration. Under normal conditions, FAPs lack myogenic potential and thus do not directly contribute to regenerated myofibers. Surprisingly, Saccone and colleagues (pp. 841–857) demonstrated that the dystrophic muscle environment causes FAPs to adopt a chromatin state that imparts these cells with myogenic potential. In this context, treatment of muscle with deacetylase inhibitors activates a BAF60c–myomiR transcriptional network in FAPs, blocking adipogenesis and driving muscle differentiation.
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Affiliation(s)
- Herve Faralli
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
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28
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Sebastian S, Faralli H, Yao Z, Rakopoulos P, Palii C, Cao Y, Singh K, Liu QC, Chu A, Aziz A, Brand M, Tapscott SJ, Dilworth FJ. Tissue-specific splicing of a ubiquitously expressed transcription factor is essential for muscle differentiation. Genes Dev 2013; 27:1247-59. [PMID: 23723416 DOI: 10.1101/gad.215400.113] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Alternate splicing contributes extensively to cellular complexity by generating protein isoforms with divergent functions. However, the role of alternate isoforms in development remains poorly understood. Mef2 transcription factors are essential transducers of cell signaling that modulate differentiation of many cell types. Among Mef2 family members, Mef2D is unique, as it undergoes tissue-specific splicing to generate a muscle-specific isoform. Since the ubiquitously expressed (Mef2Dα1) and muscle-specific (Mef2Dα2) isoforms of Mef2D are both expressed in muscle, we examined the relative contribution of each Mef2D isoform to differentiation. Using both in vitro and in vivo models, we demonstrate that Mef2D isoforms act antagonistically to modulate differentiation. While chromatin immunoprecipitation (ChIP) sequencing analysis shows that the Mef2D isoforms bind an overlapping set of genes, only Mef2Dα2 activates late muscle transcription. Mechanistically, the differential ability of Mef2D isoforms to activate transcription depends on their susceptibility to phosphorylation by protein kinase A (PKA). Phosphorylation of Mef2Dα1 by PKA provokes its association with corepressors. Conversely, exon switching allows Mef2Dα2 to escape this inhibitory phosphorylation, permitting recruitment of Ash2L for transactivation of muscle genes. Thus, our results reveal a novel mechanism in which a tissue-specific alternate splicing event has evolved that permits a ubiquitously expressed transcription factor to escape inhibitory signaling for temporal regulation of gene expression.
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Affiliation(s)
- Soji Sebastian
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
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Singh K, Dilworth FJ. Differential modulation of cell cycle progression distinguishes members of the myogenic regulatory factor family of transcription factors. FEBS J 2013; 280:3991-4003. [DOI: 10.1111/febs.12188] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/01/2013] [Accepted: 02/05/2013] [Indexed: 12/29/2022]
Affiliation(s)
- Kulwant Singh
- Sprott Center for Stem Cell Research; Ottawa Hospital Research Institute; ON; Canada
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30
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Abstract
Satellite cells represent the primary population of stem cells resident in skeletal muscle. These adult muscle stem cells facilitate the postnatal growth, remodeling, and regeneration of skeletal muscle. Given the remarkable regenerative potential of satellite cells, there is great promise for treatment of muscle pathologies such as the muscular dystrophies with this cell population. Various protocols have been developed which allow for isolation, enrichment, and expansion of satellite cell derived muscle stem cells. However, isolated satellite cells have yet to translate into effective modalities for therapeutic intervention. Broadening our understanding of satellite cells and their niche requirements should improve our in vivo and ex vivo manipulation of these cells to expedite their use for regeneration of diseased muscle. This review explores the fates of satellite cells as determined by their molecular signatures, ontogeny, and niche dependent programming.
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Affiliation(s)
- Arif Aziz
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Rd, Mailbox 511, Ottawa, ON, Canada K1H 8L6
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31
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Liu QC, Zha XH, Faralli H, Yin H, Louis-Jeune C, Perdiguero E, Pranckeviciene E, Muñoz-Cànoves P, Rudnicki MA, Brand M, Perez-Iratxeta C, Dilworth FJ. Comparative expression profiling identifies differential roles for Myogenin and p38α MAPK signaling in myogenesis. J Mol Cell Biol 2012; 4:386-97. [PMID: 22847234 DOI: 10.1093/jmcb/mjs045] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Skeletal muscle differentiation is mediated by a complex gene expression program requiring both the muscle-specific transcription factor Myogenin (Myog) and p38α MAPK (p38α) signaling. However, the relative contribution of Myog and p38α to the formation of mature myotubes remains unknown. Here, we have uncoupled the activity of Myog from that of p38α to gain insight into the individual roles of these proteins in myogenesis. Comparative expression profiling confirmed that Myog activates the expression of genes involved in muscle function. Furthermore, we found that in the absence of p38α signaling, Myog expression leads to the down-regulation of genes involved in cell cycle progression. Consistent with this, the expression of Myog is sufficient to induce cell cycle exit. Interestingly, p38α-defective, Myog-expressing myoblasts fail to form multinucleated myotubes, suggesting an important role for p38α in cell fusion. Through the analysis of p38α up-regulated genes, the tetraspanin CD53 was identified as a candidate fusion protein, a role confirmed both ex vivo in primary myoblasts, and in vivo during myofiber regeneration in mice. Thus, our study has revealed an unexpected role for Myog in mediating cell cycle exit and has identified an essential role for p38α in cell fusion through the up-regulation of CD53.
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Affiliation(s)
- Qi-Cai Liu
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada K1H 8L6
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32
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Abstract
Nuclear spatial organization of genes has emerged as an important determinant of their transcriptional activity. In this issue, Wang et al. (2011) show that the Msx1 homeoprotein induces a dramatic redistribution of Ezh2 and H3K27me3 to the nuclear periphery of muscle progenitor cells to repress transcription of developmentally regulated genes.
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Affiliation(s)
- Kulwant Singh
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
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33
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Forcales SV, Albini S, Giordani L, Malecova B, Cignolo L, Chernov A, Coutinho P, Saccone V, Consalvi S, Williams R, Wang K, Wu Z, Baranovskaya S, Miller A, Dilworth FJ, Puri PL. Signal-dependent incorporation of MyoD-BAF60c into Brg1-based SWI/SNF chromatin-remodelling complex. EMBO J 2011; 31:301-16. [PMID: 22068056 DOI: 10.1038/emboj.2011.391] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 10/02/2011] [Indexed: 12/13/2022] Open
Abstract
Tissue-specific transcriptional activators initiate differentiation towards specialized cell types by inducing chromatin modifications permissive for transcription at target loci, through the recruitment of SWItch/Sucrose NonFermentable (SWI/SNF) chromatin-remodelling complex. However, the molecular mechanism that regulates SWI/SNF nuclear distribution in response to differentiation signals is unknown. We show that the muscle determination factor MyoD and the SWI/SNF subunit BAF60c interact on the regulatory elements of MyoD-target genes in myoblasts, prior to activation of transcription. BAF60c facilitates MyoD binding to target genes and marks the chromatin for signal-dependent recruitment of the SWI/SNF core to muscle genes. BAF60c phosphorylation on a conserved threonine by differentiation-activated p38α kinase is the signal that promotes incorporation of MyoD-BAF60c into a Brg1-based SWI/SNF complex, which remodels the chromatin and activates transcription of MyoD-target genes. Our data support an unprecedented two-step model by which pre-assembled BAF60c-MyoD complex directs recruitment of SWI/SNF to muscle loci in response to differentiation cues.
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Affiliation(s)
- Sonia V Forcales
- Muscle Development and Regeneration Program, Sanford-Burnham Institute for Medical Research, La Jolla, CA, USA
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34
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Faralli H, Martin E, Coré N, Liu QC, Filippi P, Dilworth FJ, Caubit X, Fasano L. Teashirt-3, a novel regulator of muscle differentiation, associates with BRG1-associated factor 57 (BAF57) to inhibit myogenin gene expression. J Biol Chem 2011; 286:23498-510. [PMID: 21543328 DOI: 10.1074/jbc.m110.206003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In adult muscles and under normal physiological conditions, satellite cells are found in a quiescent state but can be induced to enter the cell cycle by signals resulting from exercise, injury-induced muscle regeneration, or specific disease states. Once activated, satellite cells proliferate, self-renew, and differentiate to form myofibers. In the present study, we found that the zinc finger-containing factor Teashirt-3 (TSHZ3) was expressed in quiescent satellite cells of adult mouse skeletal muscles. We showed that following treatment with cardiotoxin TSHZ3 was strongly expressed in satellite cells of regenerating muscles. Moreover, immunohistochemical analysis indicated that TSHZ3 was expressed in both quiescent and activated satellite cells on intact myofibers in culture. TSHZ3 expression was maintained in myoblasts but disappeared with myotube formation. In C2C12 myoblasts, we showed that overexpression of Tshz3 impaired myogenic differentiation and promoted the down-regulation of myogenin (Myog) and up-regulation of paired-box factor 7 (Pax7). Moreover, knockdown experiments revealed a selective effect of Tshz3 on Myog regulation, and transcriptional reporter experiments indicated that TSHZ3 repressed Myog promoter. We identified the BRG1-associated factor 57 (BAF57), a subunit of the SWI/SNF complex, as a partner of TSHZ3. We showed that TSHZ3 cooperated with BAF57 to repress MYOD-dependent Myog expression. These results suggest a novel mechanism for transcriptional repression by TSHZ3 in which TSHZ3 and BAF57 cooperate to modulate MyoD activity on the Myog promoter to regulate skeletal muscle differentiation.
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Affiliation(s)
- Hervé Faralli
- Institut de Biologie du Développement de Marseille Luminy, UMR 6216, CNRS-Université de la Méditerranée, Campus de Luminy, Case 907, 13288 Marseille Cedex 09, France
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35
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Abstract
Satellite cells are a population of adult muscle stem cells that play a key role in mediating muscle regeneration. Activation of these quiescent stem cells in response to muscle injury involves modulating expression of multiple developmentally regulated genes, including mediators of the muscle-specific transcription program: Pax7, Myf5, MyoD and myogenin. Here we present evidence suggesting an essential role for the antagonistic Polycomb group and Trithorax group proteins in the epigenetic marking of muscle-specific genes to ensure proper temporal and spatial expression during muscle regeneration. The importance of Polycomb group and Trithorax group proteins in establishing chromatin structure at muscle-specific genes suggests that therapeutic modulation of their activity in satellite cells could represent a viable approach for repairing damaged muscle in muscular dystrophy.
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Affiliation(s)
- F Jeffrey Dilworth
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Mailbox 511, Ottawa, Ontario, Canada K1H 8L6.
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36
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Palii CG, Perez-Iratxeta C, Yao Z, Cao Y, Dai F, Davison J, Atkins H, Allan D, Dilworth FJ, Gentleman R, Tapscott SJ, Brand M. Differential genomic targeting of the transcription factor TAL1 in alternate haematopoietic lineages. EMBO J 2010; 30:494-509. [PMID: 21179004 PMCID: PMC3034015 DOI: 10.1038/emboj.2010.342] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 11/30/2010] [Indexed: 12/03/2022] Open
Abstract
Expression of the basic helix-loop-helix transcription factor TAL1/SCL is required for erythrocyte differentiation; aberrant expression in lymphoid cells leads to oncogenic transformation. Here, global analysis of TAL1 binding in erythroid and malignant T cells identifies cell type specific functional interaction with the transcription factors RUNX and ETS1. TAL1/SCL is a master regulator of haematopoiesis whose expression promotes opposite outcomes depending on the cell type: differentiation in the erythroid lineage or oncogenesis in the T-cell lineage. Here, we used a combination of ChIP sequencing and gene expression profiling to compare the function of TAL1 in normal erythroid and leukaemic T cells. Analysis of the genome-wide binding properties of TAL1 in these two haematopoietic lineages revealed new insight into the mechanism by which transcription factors select their binding sites in alternate lineages. Our study shows limited overlap in the TAL1-binding profile between the two cell types with an unexpected preference for ETS and RUNX motifs adjacent to E-boxes in the T-cell lineage. Furthermore, we show that TAL1 interacts with RUNX1 and ETS1, and that these transcription factors are critically required for TAL1 binding to genes that modulate T-cell differentiation. Thus, our findings highlight a critical role of the cellular environment in modulating transcription factor binding, and provide insight into the mechanism by which TAL1 inhibits differentiation leading to oncogenesis in the T-cell lineage.
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Affiliation(s)
- Carmen G Palii
- The Sprott Center for Stem Cell Research, Department of Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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37
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Abstract
MyoD is a master regulator of the skeletal muscle gene expression program. ChIP-Seq analysis has recently revealed that MyoD binds to a large number of genomic loci in differentiating myoblasts, yet only activates transcription at a subset of these genes. Here we discuss recent data suggesting that the ability of MyoD to mediate gene expression is regulated through the function of Polycomb and Trithorax Group proteins. Based on studies of the muscle-specific myog gene, we propose a model where the transcriptional activators Mef2d and Six4 mediate recruitment of Trithorax Group proteins Ash2L/MLL2 and UTX to MyoD-bound promoters to overcome the Polycomb-mediated repression of muscle genes. Modulation of the interaction between Ash2L/MLL2 and Mef2d by the p38α MAPK signaling pathway in turns provides fine-tuning of the muscle-specific gene expression program. Thus Mef2d, Six4, and p38α MAPK function coordinately as regulators of a master regulator to mediate expression of MyoD target genes.
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Affiliation(s)
- Arif Aziz
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, CA
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38
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Rampalli S, Li L, Mak E, Ge K, Brand M, Tapscott SJ, Dilworth FJ. p38 MAPK signaling regulates recruitment of Ash2L-containing methyltransferase complexes to specific genes during differentiation. Nat Struct Mol Biol 2007; 14:1150-6. [PMID: 18026121 DOI: 10.1038/nsmb1316] [Citation(s) in RCA: 177] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 09/19/2007] [Indexed: 02/07/2023]
Abstract
Cell-specific patterns of gene expression are established through the antagonistic functions of trithorax group (TrxG) and Polycomb group (PcG) proteins. Several muscle-specific genes have previously been shown to be epigenetically marked for repression by PcG proteins in muscle progenitor cells. Here we demonstrate that these developmentally regulated genes become epigenetically marked for gene expression (trimethylated on histone H3 Lys4, H3K4me3) during muscle differentiation through specific recruitment of Ash2L-containing methyltransferase complexes. Targeting of Ash2L to specific genes is mediated by the transcriptional regulator Mef2d. Furthermore, this interaction is modulated during differentiation through activation of the p38 MAPK signaling pathway via phosphorylation of Mef2d. Thus, we provide evidence that signaling pathways regulate the targeting of TrxG-mediated epigenetic modifications at specific promoters during cellular differentiation.
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Affiliation(s)
- Shravanti Rampalli
- Sprott Center for Stem Cell Research, Ottawa Health Research Institute, Ottawa, Ontario K1H 8L6, Canada
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39
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Demers C, Chaturvedi CP, Ranish JA, Juban G, Lai P, Morle F, Aebersold R, Dilworth FJ, Groudine M, Brand M. Activator-mediated recruitment of the MLL2 methyltransferase complex to the beta-globin locus. Mol Cell 2007; 27:573-84. [PMID: 17707229 PMCID: PMC2034342 DOI: 10.1016/j.molcel.2007.06.022] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Revised: 05/14/2007] [Accepted: 06/14/2007] [Indexed: 02/08/2023]
Abstract
MLL-containing complexes methylate histone H3 at lysine 4 (H3K4) and have been implicated in the regulation of transcription. However, it is unclear how MLL complexes are targeted to specific gene loci. Here, we show that the MLL2 complex associates with the hematopoietic activator NF-E2 in erythroid cells and is important for H3K4 trimethylation and maximal levels of transcription at the beta-globin locus. Furthermore, recruitment of the MLL2 complex to the beta-globin locus is dependent upon NF-E2 and coincides spatio-temporally with NF-E2 binding during erythroid differentiation. Thus, a DNA-bound activator is important initially for guiding MLL2 to a particular genomic location. Interestingly, while the MLL2-associated subunit ASH2L is restricted to the beta-globin locus control region 38 kb upstream of the beta(maj)-globin gene, the MLL2 protein spreads across the beta-globin locus, suggesting a previously undefined mechanism by which an activator influences transcription and H3K4 trimethylation at a distance.
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Affiliation(s)
- Celina Demers
- Sprott Center for Stem Cell Research, Ottawa Health Research Institute, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada
| | - Chandra-Prakash Chaturvedi
- Sprott Center for Stem Cell Research, Ottawa Health Research Institute, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada
| | - Jeffrey A. Ranish
- Institute for Systems Biology, 1441 North 34th Street, Seattle, WA, 98103, USA
| | - Gaetan Juban
- Centre de Génétique Moléculaire et Cellulaire, UMR 5534, CNRS-Université Claude Bernard, Lyon-1, 16 rue Dubois, 69622 Villeurbanne, France
| | - Patrick Lai
- Sprott Center for Stem Cell Research, Ottawa Health Research Institute, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada
| | - Francois Morle
- Centre de Génétique Moléculaire et Cellulaire, UMR 5534, CNRS-Université Claude Bernard, Lyon-1, 16 rue Dubois, 69622 Villeurbanne, France
| | - Ruedi Aebersold
- Institute for Systems Biology, 1441 North 34th Street, Seattle, WA, 98103, USA
- Institute of Molecular Systems Biology, ETH Honggerberg HPT E 78, Wolfgang Pauli-Str. 16, CH-8093 Zurich, and Faculty of Science, University of Zurich, Switzerland
| | - F. Jeffrey Dilworth
- Sprott Center for Stem Cell Research, Ottawa Health Research Institute, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada
| | - Mark Groudine
- Fred Hutchinson Cancer Research Center, 1100 Fairview Av. N., Seattle, WA, 98109, USA
- To whom correspondance should be addressed. , phone (613) 737-7700 ext. 70336, fax (613) 737-8803 phone (206) 667-4497, fax (206) 667-5894
| | - Marjorie Brand
- Sprott Center for Stem Cell Research, Ottawa Health Research Institute, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada
- University of Ottawa, Department of Cellular and Molecular Medicine and Ottawa Institute of Systems Biology, 451 Smyth Road, Ottawa, ON K1H 8L6, Canada
- To whom correspondance should be addressed. , phone (613) 737-7700 ext. 70336, fax (613) 737-8803 phone (206) 667-4497, fax (206) 667-5894
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40
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Caretti G, Schiltz RL, Dilworth FJ, Di Padova M, Zhao P, Ogryzko V, Fuller-Pace FV, Hoffman EP, Tapscott SJ, Sartorelli V. The RNA helicases p68/p72 and the noncoding RNA SRA are coregulators of MyoD and skeletal muscle differentiation. Dev Cell 2006; 11:547-60. [PMID: 17011493 DOI: 10.1016/j.devcel.2006.08.003] [Citation(s) in RCA: 226] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Revised: 07/26/2006] [Accepted: 08/16/2006] [Indexed: 11/18/2022]
Abstract
MyoD regulates skeletal myogenesis. Since proteins associated with MyoD exert regulatory functions, their identification is expected to contribute important insights into the mechanisms governing gene expression in skeletal muscle. We have found that the RNA helicases p68/p72 are MyoD-associated proteins and that the noncoding RNA SRA also immunoprecipitates with MyoD. In vitro and in vivo experiments indicated that both p68/p72 and SRA are coactivators of MyoD. RNA interference toward either p68/p72 or SRA prevented proper activation of muscle gene expression and cell differentiation. Unexpectedly, reducing the levels of p68/p72 proteins impaired recruitment of the TATA binding protein TBP; RNA polymerase II; and the catalytic subunit of the ATPase SWI/SNF complex, Brg-1, and hindered chromatin remodeling. These findings reveal that p68/p72 play a critical role in promoting the assembly of proteins required for the formation of the transcription initiation complex and chromatin remodeling.
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Affiliation(s)
- Giuseppina Caretti
- Muscle Gene Expression Group, Laboratory of Muscle Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20829, USA
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41
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Pavri R, Lewis B, Kim TK, Dilworth FJ, Erdjument-Bromage H, Tempst P, de Murcia G, Evans R, Chambon P, Reinberg D. PARP-1 Determines Specificity in a Retinoid Signaling Pathway via Direct Modulation of Mediator. Mol Cell 2005; 18:83-96. [PMID: 15808511 DOI: 10.1016/j.molcel.2005.02.034] [Citation(s) in RCA: 188] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2004] [Revised: 01/26/2005] [Accepted: 02/28/2005] [Indexed: 12/20/2022]
Abstract
We show that PARP-1 is indispensable to retinoic acid receptor (RAR)-mediated transcription from the RARbeta2 promoter in a highly purified, reconstituted transcription system and that RA-inducible expression of all RARbeta isoforms is abrogated in PARP-1(-/-) cells in vivo. Importantly, PARP-1 activity was independent of its catalytic domain. PARP-1 directly interacts with RAR and Mediator. Chromatin immunoprecipitation experiments confirmed the presence of PARP-1 and Mediator on RAR-responsive promoters in vivo. Importantly, Mediator was inactive (Cdk8+) under basal conditions but was activated (Cdk8-) upon induction. However, in PARP-1(-/-) cells, Mediator was retained in its inactive state (Cdk8+) upon induction consistent with the absence of gene expression. PARP-1 became dispensable for ligand-dependent transcription in a chromatin reconstituted transcription assay when Mediator was devoid of the Cdk8 module (CRSP). PARP-1 appears to function as a specificity factor regulating the RA-induced switch of Mediator from the inactive (Cdk8+) to the active (Cdk8-) state in RAR-dependent transcription.
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Affiliation(s)
- Rushad Pavri
- Department of Biochemistry, Howard Hughes Medical Institute, University of Medicine and Dentistry of New Jersey, 683 Hoes Lane, Piscataway, New Jersey 08854, USA
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42
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Penn BH, Bergstrom DA, Dilworth FJ, Bengal E, Tapscott SJ. A MyoD-generated feed-forward circuit temporally patterns gene expression during skeletal muscle differentiation. Genes Dev 2004; 18:2348-53. [PMID: 15466486 PMCID: PMC522984 DOI: 10.1101/gad.1234304] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The development and differentiation of distinct cell types is achieved through the sequential expression of subsets of genes; yet, the molecular mechanisms that temporally pattern gene expression remain largely unknown. In skeletal myogenesis, gene expression is initiated by MyoD and includes the expression of specific Mef2 isoforms and activation of the p38 mitogen-activated protein kinase (MAPK) pathway. Here, we show that p38 activity facilitates MyoD and Mef2 binding at a subset of late-activated promoters, and the binding of Mef2D recruits Pol II. Most importantly, expression of late-activated genes can be shifted to the early stages of differentiation by precocious activation of p38 and expression of Mef2D, demonstrating that a MyoD-mediated feed-forward circuit temporally patterns gene expression.
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Affiliation(s)
- Bennett H Penn
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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43
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Dilworth FJ, Seaver KJ, Fishburn AL, Htet SL, Tapscott SJ. In vitro transcription system delineates the distinct roles of the coactivators pCAF and p300 during MyoD/E47-dependent transactivation. Proc Natl Acad Sci U S A 2004; 101:11593-8. [PMID: 15289617 PMCID: PMC511026 DOI: 10.1073/pnas.0404192101] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transcriptional coactivators p300 and pCAF are necessary for the myogenic factor MyoD to initiate the expression of skeletal muscle genes. In addition to mediating histone acetylation, both of these factors can acetylate MyoD; however, the complexity of cellular systems used to study MyoD has impeded delineation of the specific roles of these two acetyltransferases. Therefore, we established a MyoD-dependent in vitro transcription system that permits us to determine the roles of p300 and pCAF during MyoD-dependent transcriptional activation. Consistent with results from cellular systems, we demonstrate that maximal levels of transactivation in vitro require both p300 and pCAF, as well as the cofactor acetyl CoA. Dissection of the steps leading to transcription initiation revealed that the activities of p300 and pCAF are not redundant. During the initial stages of transactivation, p300 acetylates histone H3 and H4 within the promoter region and then recruits pCAF to MyoD. Once tethered to the promoter, pCAF acetylates MyoD to facilitate the transactivation process. Thus, we have established that pCAF and p300 carry out sequential and functionally distinct events on a promoter leading to transcriptional activation. Further dissection of this in vitro transcription system should be highly useful toward elucidating the mechanism by which coactivators facilitate differential gene expression by MyoD.
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Affiliation(s)
- F Jeffrey Dilworth
- Division of Human Biology, Fred Hutchinson Cancer Research Center, and Department of Pathology, University of Washington School of Medicine, 1100 Fairview Avenue North C3-168, P.O. Box 19024, Seattle, WA 98109-1024, USA.
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44
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Georgieva S, Nabirochkina E, Dilworth FJ, Eickhoff H, Becker P, Tora L, Georgiev P, Soldatov A. The novel transcription factor e(y)2 interacts with TAF(II)40 and potentiates transcription activation on chromatin templates. Mol Cell Biol 2001; 21:5223-31. [PMID: 11438676 PMCID: PMC87246 DOI: 10.1128/mcb.21.15.5223-5231.2001] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Weak hypomorph mutations in the enhancer of yellow genes, e(y)1 and e(y)2, of Drosophila melanogaster were discovered during the search for genes involved in the organization of interaction between enhancers and promoters. Previously, the e(y)1 gene was cloned and found to encode TAF(II)40 protein. Here we cloned the e(y)2 gene and demonstrated that it encoded a new ubiquitous evolutionarily conserved transcription factor. The e(y)2 gene is located at 10C3 (36.67) region and is expressed at all stages of Drosophila development. It encodes a 101-amino-acid protein, e(y)2. Vertebrates, insects, protozoa, and plants have proteins which demonstrate a high degree of homology to e(y)2. The e(y)2 protein is localized exclusively to the nuclei and is associated with numerous sites along the entire length of the salivary gland polytene chromosomes. Both genetic and biochemical experiments demonstrate an interaction between e(y)2 and TAF(II)40, while immunoprecipitation studies demonstrate that the major complex, including both proteins, appears to be distinct from TFIID. Furthermore, we provide genetic evidence suggesting that the carboxy terminus of dTAF(II)40 is important for mediating this interaction. Finally, using an in vitro transcription system, we demonstrate that recombinant e(y)2 is able to enhance transactivation by GAL4-VP16 on chromatin but not on naked DNA templates, suggesting that this novel protein is involved in the regulation of transcription.
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Affiliation(s)
- S Georgieva
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 117334 Moscow, Russia
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Dilworth FJ, Chambon P. Nuclear receptors coordinate the activities of chromatin remodeling complexes and coactivators to facilitate initiation of transcription. Oncogene 2001; 20:3047-54. [PMID: 11420720 DOI: 10.1038/sj.onc.1204329] [Citation(s) in RCA: 191] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent advances in the field of in vitro chromatin assembly have led to in vitro transcription systems which reproduce in the test tube, in vivo characteristics of ligand-dependent transcriptional activation by nuclear receptors. Dissection of these systems has begun to provide us with information concerning the underlying molecular mechanisms. Through recruitment of coactivator proteins, nuclear receptors act first to remodel chromatin within the promoter region and then to recruit the transcriptional machinery to the promoter region in order to initiate transcription. Here we present a possible sequential mechanism for ligand-dependent transcriptional activation by nuclear receptors and discuss the in vitro and in vivo data that support this model.
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Affiliation(s)
- F J Dilworth
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS/INSERM/ULP/Collège de France, BP163, 67404 Illkirch Cedex, CU de Strasbourg, France
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Dilworth FJ, Fromental-Ramain C, Yamamoto K, Chambon P. ATP-driven chromatin remodeling activity and histone acetyltransferases act sequentially during transactivation by RAR/RXR In vitro. Mol Cell 2000; 6:1049-58. [PMID: 11106744 DOI: 10.1016/s1097-2765(00)00103-9] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Using a "crude" chromatin-based transcription system that mimics transactivation by RAR/RXR heterodimers in vivo, we could not demonstrate that chromatin remodeling was required to relieve nucleosomal repression. Using "purified" chromatin templates, we show here that, irrespective of the presence of histone H1, both ATP-driven chromatin remodeling activities and histone acetyltransferase (HAT) activities of coactivators recruited by liganded receptors are required to achieve transactivation. DNA footprinting, ChIP analysis, and order of addition experiments indicate that coactivator HAT activities and two ATP-driven remodeling activities are sequentially involved at distinct steps preceding initiation of transcription. Thus, both ATP-driven chromatin remodeling and HAT activities act in a temporally ordered and interdependent manner to alleviate the repressive effects of nucleosomal histones on transcription by RARalpha/RXRalpha heterodimers.
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Affiliation(s)
- F J Dilworth
- Institut de Genetique et de Biologie Moleculaire et Cellulaire CNRS/INSERM/ULP/College de France 67404 Cedex CU de Strasbourg, Illkirch, France
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47
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van den Bemd GC, Dilworth FJ, Makin HL, Prahl JM, Deluca HF, Jones G, Pols HA, van Leeuwen JP. Contribution of several metabolites of the vitamin D analog 20-epi-22-oxa-24a,26a,27a-tri-homo-1,25-(OH)(2) vitamin D(3) (KH 1060) to the overall biological activity of KH1060 by a shared mechanism of action. Biochem Pharmacol 2000; 59:621-7. [PMID: 10677578 DOI: 10.1016/s0006-2952(99)00371-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The synthetic 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) analog 20-epi-22-oxa-24a,26a,27a-tri-homo-1,25-(OH)(2)vitamin D(3) (KH1060) is considerably more potent than its cognate hormone. The mechanism of action of KH1060 includes interaction with the vitamin D receptor (VDR). We previously showed that KH1060 increases VDR stability in ROS 17/2.8 osteoblastic cells by inducing a specific conformational change in the VDR. KH1060 is metabolized, both in vivo and in vitro, into several stable products. In the present study, we investigated whether these metabolites might contribute to the increased biological activity of KH1060. We found that the potencies of two of these metabolites, 24a-OH-KH1060 and 26-OH-KH1060, were similar to that of 1,25-(OH)(2)D(3) in inducing osteocalcin production by the osteoblast cell line ROS 17/2.8. This report further showed that these metabolites had the same effects as KH1060 on VDR: they increased VDR stability in ROS 17/2.8 cells, while limited proteolytic analysis revealed that they caused a conformational change in the VDR, resulting in an increased resistance against proteolytic cleavage. Furthermore, as shown in gel mobility shift assays, both compounds clearly induced VDR binding to vitamin D response elements. Together, these results show that the potent in vitro activity of KH1060 is not only directed by the effects on the VDR conformation/stabilization of the analog itself, but also by certain of its long-lived metabolites, and emphasizes the importance of detailed knowledge of the metabolism of synthetic hormonal analogs.
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Affiliation(s)
- G C van den Bemd
- Department of Internal Medicine III, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
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Dilworth FJ, Fromental-Ramain C, Remboutsika E, Benecke A, Chambon P. Ligand-dependent activation of transcription in vitro by retinoic acid receptor alpha/retinoid X receptor alpha heterodimers that mimics transactivation by retinoids in vivo. Proc Natl Acad Sci U S A 1999; 96:1995-2000. [PMID: 10051583 PMCID: PMC26725 DOI: 10.1073/pnas.96.5.1995] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
All-trans and 9-cis retinoic acids (RA) signals are transduced by retinoic acid receptor/retinoid X receptor (RAR/RXR) heterodimers that act as functional units controlling the transcription of RA-responsive genes. With the aim of elucidating the underlying molecular mechanisms, we have developed an in vitro transcription system using a chromatin template made up of a minimal promoter and a direct repeat with 5-spacing-based RA response element. RARalpha and RXRalpha were expressed in and purified from baculovirus-infected Sf9 cells, and transcription was carried out by using naked DNA or chromatin templates. Transcription from naked templates was not affected by the presence of RA and/or RAR/RXR heterodimers. In contrast, very little transcription occurred from chromatin templates in the absence of RA or RAR/RXR heterodimers whereas their addition resulted in a dosage-dependent stimulation of transcription that never exceeded that occurring on naked DNA templates. Most importantly, the addition of synthetic agonistic or antagonistic retinoids to the chromatin transcription system mimicked their stimulatory or inhibitory action in vivo, and activation by a RXR-specific retinoid was subordinated to the binding of an agonist ligand to the RAR partner. Moreover, the addition of the p300 coactivator generated a synergistic enhancement of transcription. Thus, the dissection of this transcription system ultimately should lead to the elucidation of the molecular mechanisms by which RAR/RXR heterodimers control transcription in a ligand-dependent manner.
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Affiliation(s)
- F J Dilworth
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Collège de France, BP163, 67404 Illkirch Cedex, France
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Dilworth FJ, Williams GR, Kissmeyer AM, Nielsen JL, Binderup E, Calverley MJ, Makin HL, Jones G. The vitamin D analog, KH1060, is rapidly degraded both in vivo and in vitro via several pathways: principal metabolites generated retain significant biological activity. Endocrinology 1997; 138:5485-96. [PMID: 9389535 DOI: 10.1210/endo.138.12.5594] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Vitamin D analogs are valuable drugs with established and potential uses in hyperproliferative disorders. Lexacalcitol (KH1060) is over 100 times more active than 1alpha,25-dihydroxyvitamin D3 [1alpha,25-(OH)2D3], as judged by in vitro antiproliferative and cell differentiating assays. The underlying biochemical reasons for the increased biological activity of KH1060 are unknown, but are thought to include 1) metabolic considerations in addition to explanations based upon 2) enhanced stability of KH1060-liganded transcriptional complexes. In this study we explored the in vivo and in vitro metabolism of KH1060. We established by physicochemical techniques the existence of multiple side-chain hydroxylated metabolites of KH1060, including 24-, 24a-, 26-, and 26a-hydroxylated derivatives as well as side-chain truncated forms. KH1060 metabolism could be blocked by the cytochrome P450 inhibitor, ketoconazole. KH1060 was not an effective competitor of C24 oxidation of 1alpha,25-(OH)2D3. Certain hydroxylated metabolites of KH1060 retained significant biological activity in vitamin D-dependent reporter gene systems (chloramphenicol acetyltransferase). Likewise, those metabolites accumulating in the target cell culture models in metabolism studies, particularly 24a-hydroxy-KH1060 and 26-hydroxy-KH1060, retained biological activities superior to those of 1alpha,25-(OH)2D3 in native gene expression systems in vitamin D target cells (osteopontin and P450cc24). We conclude that KH1060 is rapidly metabolized by a variety of cytochrome P450-mediated enzyme systems to products, many of which retain significant biological activity in vitamin D-dependent assay systems. These results provide an explanation for the considerable biological activity advantage displayed by KH1060 compared with 1alpha,25-(OH)2D3 in various in vitro assay systems.
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Affiliation(s)
- F J Dilworth
- Department of Biochemistry, Queen's University, Kingston, Ontario, Canada
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White JA, Beckett-Jones B, Guo YD, Dilworth FJ, Bonasoro J, Jones G, Petkovich M. cDNA cloning of human retinoic acid-metabolizing enzyme (hP450RAI) identifies a novel family of cytochromes P450. J Biol Chem 1997; 272:18538-41. [PMID: 9228017 DOI: 10.1074/jbc.272.30.18538] [Citation(s) in RCA: 305] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Retinoids, including all-trans-retinoic acid (RA) and its stereoisomer 9-cis-RA play important roles in regulating gene expression, through interactions with nuclear receptors, during embryonic development and in the maintenance of adult epithelial tissues (Chambon, P. (1995) Rec. Prog. Horm. Res. 50, 317-32; Mangelsdorf, D. J., and Evans, R. M. (1995) Cell 83, 841-850; Petkovich, M. (1992) Annu. Rev. Nutr. 12, 443-471). Evidence suggests that 4-hydroxylation of RA inside the target cell limits its biological activity and initiates a degradative process of RA leading to its eventual elimination. However, 18-hydroxylation and glucuronidation may also be important steps in this process. In this paper, we describe the cloning and characterization of the first mammalian retinoic acid-inducible retinoic acid-metabolizing cytochrome P450 (hP450RAI), which belongs to a novel class of cytochromes (CYP26). We demonstrate that hP450RAI is responsible for generation of several hydroxylated forms of RA, including 4-OH-RA, 4-oxo-RA, and 18-OH-RA. We also show that hP450RAI mRNA expression is highly induced by RA in certain human tumor cell lines and further show that RA-inducible RA metabolism may correlate with P450RAI expression. We conclude that this enzyme plays a key role in RA metabolism, functioning in a feedback loop where RA levels are controlled in an autoregulatory manner.
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Affiliation(s)
- J A White
- Cancer Research Laboratories, Queen's University, Kingston, Ontario, Canada K7L 3N6
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