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León NY, Le TNU, Garvie A, Wong LH, Bagheri-Fam S, Harley VR. Y chromosome damage underlies testicular abnormalities in ATR-X syndrome. iScience 2024; 27:109629. [PMID: 38616920 PMCID: PMC11015497 DOI: 10.1016/j.isci.2024.109629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/27/2024] [Accepted: 03/26/2024] [Indexed: 04/16/2024] Open
Abstract
ATR-X (alpha thalassemia, mental retardation, X-linked) syndrome features genital and testicular abnormalities including atypical genitalia and small testes with few seminiferous tubules. Our mouse model recapitulated the testicular defects when Atrx was deleted in Sertoli cells (ScAtrxKO) which displayed G2/M arrest and apoptosis. Here, we investigated the mechanisms underlying these defects. In control mice, Sertoli cells contain a single novel "GATA4 PML nuclear body (NB)" that contained the transcription factor GATA4, ATRX, DAXX, HP1α, and PH3 and co-localized with the Y chromosome short arm (Yp). ScAtrxKO mice contain single giant GATA4 PML-NBs with frequent DNA double-strand breaks (DSBs) in G2/M-arrested apoptotic Sertoli cells. HP1α and PH3 were absent from giant GATA4 PML-NBs indicating a failure in heterochromatin formation and chromosome condensation. Our data suggest that ATRX protects a Yp region from DNA damage, thereby preventing Sertoli cell death. We discuss Y chromosome damage/decondensation as a mechanism for testicular failure.
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Affiliation(s)
- Nayla Y. León
- Hudson Institute of Medical Research, Melbourne, VIC 3168, Australia
- Department of Molecular & Translational Science, Monash University, Melbourne, VIC 3168, Australia
| | - Thanh Nha Uyen Le
- Hudson Institute of Medical Research, Melbourne, VIC 3168, Australia
- Department of Molecular & Translational Science, Monash University, Melbourne, VIC 3168, Australia
| | - Andrew Garvie
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Lee H. Wong
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Stefan Bagheri-Fam
- Hudson Institute of Medical Research, Melbourne, VIC 3168, Australia
- Department of Molecular & Translational Science, Monash University, Melbourne, VIC 3168, Australia
| | - Vincent R. Harley
- Hudson Institute of Medical Research, Melbourne, VIC 3168, Australia
- Department of Molecular & Translational Science, Monash University, Melbourne, VIC 3168, Australia
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2
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Fuentes ME, Lu X, Flores NM, Hausmann S, Mazur PK. Combined deletion of MEN1, ATRX and PTEN triggers development of high-grade pancreatic neuroendocrine tumors in mice. Sci Rep 2024; 14:8510. [PMID: 38609433 PMCID: PMC11014914 DOI: 10.1038/s41598-024-58874-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 04/03/2024] [Indexed: 04/14/2024] Open
Abstract
Pancreatic neuroendocrine tumors (PanNETs) are a heterogeneous group of tumors that exhibit an unpredictable and broad spectrum of clinical presentations and biological aggressiveness. Surgical resection is still the only curative therapeutic option for localized PanNET, but the majority of patients are diagnosed at an advanced and metastatic stage with limited therapeutic options. Key factors limiting the development of new therapeutics are the extensive heterogeneity of PanNETs and the lack of appropriate clinically relevant models. In that context, genomic sequencing of human PanNETs revealed recurrent mutations and structural alterations in several tumor suppressors. Here, we demonstrated that combined loss of MEN1, ATRX, and PTEN, tumor suppressors commonly mutated in human PanNETs, triggers the development of high-grade pancreatic neuroendocrine tumors in mice. Histopathological evaluation and gene expression analyses of the developed tumors confirm the presence of PanNET hallmarks and significant overlap in gene expression patterns found in human disease. Thus, we postulate that the presented novel genetically defined mouse model is the first clinically relevant immunocompetent high-grade PanNET mouse model.
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Affiliation(s)
- Mary Esmeralda Fuentes
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Xiaoyin Lu
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Natasha M Flores
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Simone Hausmann
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Pawel K Mazur
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
- The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.
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3
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Malgulwar PB, Danussi C, Dharmaiah S, Johnson W, Singh A, Rai K, Rao A, Huse JT. Sirtuin 2 inhibition modulates chromatin landscapes genome-wide to induce senescence in ATRX-deficient malignant glioma. Neuro Oncol 2024; 26:55-67. [PMID: 37625115 PMCID: PMC10769000 DOI: 10.1093/neuonc/noad155] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Indexed: 08/27/2023] Open
Abstract
BACKGROUND Functional inactivation of ATRX characterizes large subgroups of malignant gliomas in adults and children. ATRX deficiency in glioma induces widespread chromatin remodeling, driving transcriptional shifts and oncogenic phenotypes. Effective strategies to therapeutically target these broad epigenomic sequelae remain undeveloped. METHODS We utilized integrated multiomics and the Broad Institute Connectivity Map (CMAP) to identify drug candidates that could potentially revert ATRX-deficient transcriptional changes. We then employed disease-relevant experimental models to evaluate functional phenotypes, coupling these studies with epigenomic profiling to elucidate molecular mechanism(s). RESULTS CMAP analysis and transcriptional/epigenomic profiling implicated the Class III HDAC Sirtuin2 (SIRT2) as a central mediator of ATRX-deficient cellular phenotypes and a driver of unfavorable prognosis in ATRX-deficient glioma. SIRT2 inhibitors reverted Atrx-deficient transcriptional signatures in murine neuroepithelial progenitor cells (mNPCs), impaired cell migration in Atrx/ATRX-deficient mNPCs and human glioma stem cells (GSCs), and increased expression of senescence markers in glioma models. Moreover, SIRT2 inhibition impaired growth and increased senescence in ATRX-deficient GSCs in vivo. These effects were accompanied by genome-wide shifts in enhancer-associated H3K27ac and H4K16ac marks, with the latter in particular demonstrating compelling transcriptional links to SIRT2-dependent phenotypic reversals. Motif analysis of these data identified the transcription factor KLF16 as a mediator of phenotype reversal in Atrx-deficient cells upon SIRT2 inhibition. CONCLUSIONS Our findings indicate that SIRT2 inhibition selectively targets ATRX-deficient gliomas for senescence through global chromatin remodeling, while demonstrating more broadly a viable approach to combat complex epigenetic rewiring in cancer.
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Affiliation(s)
- Prit Benny Malgulwar
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Carla Danussi
- Sanofi, Research and Development, Cambridge, Massachusetts, USA
| | - Sharvari Dharmaiah
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - William Johnson
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Anand Singh
- Department of Genomic Medicine, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Kunal Rai
- Department of Genomic Medicine, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Arvind Rao
- Departments of Biostatistics, Computational Medicine and Bioinformatics, and Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jason T Huse
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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4
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Lomeli C. S, Kristin B. A. Epigenetic regulation of craniofacial development and disease. Birth Defects Res 2024; 116:e2271. [PMID: 37964651 PMCID: PMC10872612 DOI: 10.1002/bdr2.2271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/13/2023] [Accepted: 10/24/2023] [Indexed: 11/16/2023]
Abstract
BACKGROUND The formation of the craniofacial complex relies on proper neural crest development. The gene regulatory networks (GRNs) and signaling pathways orchestrating this process have been extensively studied. These GRNs and signaling cascades are tightly regulated as alterations to any stage of neural crest development can lead to common congenital birth defects, including multiple syndromes affecting facial morphology as well as nonsyndromic facial defects, such as cleft lip with or without cleft palate. Epigenetic factors add a hierarchy to the regulation of transcriptional networks and influence the spatiotemporal activation or repression of specific gene regulatory cascades; however less is known about their exact mechanisms in controlling precise gene regulation. AIMS In this review, we discuss the role of epigenetic factors during neural crest development, specifically during craniofacial development and how compromised activities of these regulators contribute to congenital defects that affect the craniofacial complex.
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Affiliation(s)
- Shull Lomeli C.
- Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Artinger Kristin B.
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, MN, USA
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Picketts D, Mirzaa G, Yan K, Relator R, Timpano S, Yalcin B, Collins S, Ziegler A, Pao E, Oyama N, Brischoux-Boucher E, Piard J, Monaghan K, Sacoto MG, Dobyns W, Park K, Fernández-Mayoralas D, Fernández-Jaén A, Jayakar P, Brusco A, Antona V, Giorgio E, Kvarnung M, Isidor B, Conrad S, Cogné B, Deb W, Stuurman KE, Sterbova K, Smal N, Weckhuysen S, Oegema R, Innes M, Latsko M, Ben-Omran T, Yeh R, Kruer M, Bakhtiari S, Papavasiliou A, Moutton S, Nambot S, Chanprasert S, Paolucci S, Miller K, Burton B, Kim K, O'Heir E, Bruwer Z, Donald K, Kleefstra T, Goldstein A, Angle B, Bontempo K, Miny P, Joset P, Demurger F, Hobson E, Pang L, Carpenter L, Li D, Bonneau D, Sadikovic B. Pathogenic variants in SMARCA1 cause an X-linked neurodevelopmental disorder modulated by NURF complex composition. RESEARCH SQUARE 2023:rs.3.rs-3317938. [PMID: 37841849 PMCID: PMC10571636 DOI: 10.21203/rs.3.rs-3317938/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Pathogenic variants in ATP-dependent chromatin remodeling proteins are a recurrent cause of neurodevelopmental disorders (NDDs). The NURF complex consists of BPTF and either the SNF2H (SMARCA5) or SNF2L (SMARCA1) ISWI-chromatin remodeling enzyme. Pathogenic variants in BPTF and SMARCA5 were previously implicated in NDDs. Here, we describe 40 individuals from 30 families with de novo or maternally inherited pathogenic variants in SMARCA1. This novel NDD was associated with mild to severe ID/DD, delayed or regressive speech development, and some recurrent facial dysmorphisms. Individuals carrying SMARCA1 loss-of-function variants exhibited a mild genome-wide DNA methylation profile and a high penetrance of macrocephaly. Genetic dissection of the NURF complex using Smarca1, Smarca5, and Bptfsingle and double mouse knockouts revealed the importance of NURF composition and dosage for proper forebrain development. Finally, we propose that genetic alterations affecting different NURF components result in a NDD with a broad clinical spectrum.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Emily Pao
- Seattle Children's Research Institute
| | | | | | | | | | | | | | - Kristen Park
- University of Colorado Denver School of Medicine
| | | | - Alberto Fernández-Jaén
- Department of Pediatrics and Neurology, Hospital Universitario Quirónsalud, School of Medicine, Universidad Europea de Madrid
| | - Parul Jayakar
- Division of Genetics and Metabolism, Nicklaus Children's Hospital
| | | | | | | | | | | | | | | | | | - K E Stuurman
- Department of Clinical Genetics, Erasmus University Medical Center
| | | | | | | | | | | | - Maeson Latsko
- The Steve and Cindy Rasmussen Institute for Genomic Medicine
| | | | | | | | | | | | | | - Sophie Nambot
- Centre de Génétique et Centre de référence «Anomalies du Développement et Syndromes Malformatifs», Hôpital d'Enfants, Centre Hospitalier
| | | | | | | | | | | | | | | | - Kirsten Donald
- Division of Developmental Paediatrics, Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, Klipfontein Road/Private Bag, Rondebosch, 7700/7701, Cape Town, South A
| | | | | | | | | | | | | | | | | | | | | | - Dong Li
- The Children's Hospital of Philadelphia
| | - Dominique Bonneau
- Department of Biochemistry and Genetics, University Hospital of Angers, F-49000
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6
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Tillotson R, Yan K, Ruston J, DeYoung T, Córdova A, Turcotte-Cardin V, Yee Y, Taylor C, Visuvanathan S, Babbs C, Ivakine EA, Sled JG, Nieman BJ, Picketts DJ, Justice MJ. A new mouse model of ATR-X syndrome carrying a common patient mutation exhibits neurological and morphological defects. Hum Mol Genet 2023; 32:2485-2501. [PMID: 37171606 PMCID: PMC10360390 DOI: 10.1093/hmg/ddad075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/18/2023] [Accepted: 05/05/2023] [Indexed: 05/13/2023] Open
Abstract
ATRX is a chromatin remodelling ATPase that is involved in transcriptional regulation, DNA damage repair and heterochromatin maintenance. It has been widely studied for its role in ALT-positive cancers, but its role in neurological function remains elusive. Hypomorphic mutations in the X-linked ATRX gene cause a rare form of intellectual disability combined with alpha-thalassemia called ATR-X syndrome in hemizygous males. Clinical features also include facial dysmorphism, microcephaly, short stature, musculoskeletal defects and genital abnormalities. As complete deletion of ATRX in mice results in early embryonic lethality, the field has largely relied on conditional knockout models to assess the role of ATRX in multiple tissues. Given that null alleles are not found in patients, a more patient-relevant model was needed. Here, we have produced and characterized the first patient mutation knock-in model of ATR-X syndrome, carrying the most common causative mutation, R246C. This is one of a cluster of missense mutations located in the chromatin-binding domain and disrupts its function. The knock-in mice recapitulate several aspects of the patient disorder, including craniofacial defects, microcephaly, reduced body size and impaired neurological function. They provide a powerful model for understanding the molecular mechanisms underlying ATR-X syndrome and testing potential therapeutic strategies.
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Affiliation(s)
- Rebekah Tillotson
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital/Headley Way, Oxford OX3 9DS, UK
| | - Keqin Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Julie Ruston
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada
| | - Taylor DeYoung
- Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON M5T 3H7, Canada
| | - Alex Córdova
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Valérie Turcotte-Cardin
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Cellular & Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Yohan Yee
- Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON M5T 3H7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Christine Taylor
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada
| | - Shagana Visuvanathan
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada
| | - Christian Babbs
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital/Headley Way, Oxford OX3 9DS, UK
| | - Evgueni A Ivakine
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - John G Sled
- Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON M5T 3H7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada
- Translational Medicine Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada
| | - Brian J Nieman
- Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON M5T 3H7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada
- Translational Medicine Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada
- Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Cellular & Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Monica J Justice
- Genetics and Genome Biology Program, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A1, Canada
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7
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Abdallah AS, Cardona HJ, Gadd SL, Brat DJ, Powla PP, Alruwalli WS, Shen C, Picketts DJ, Li XN, Becher OJ. Novel genetically engineered H3.3G34R model reveals cooperation with ATRX loss in upregulation of Hoxa cluster genes and promotion of neuronal lineage. Neurooncol Adv 2023; 5:vdad003. [PMID: 36845293 PMCID: PMC9950856 DOI: 10.1093/noajnl/vdad003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Background Pediatric high-grade gliomas (pHGGs) are aggressive pediatric CNS tumors and an important subset are characterized by mutations in H3F3A, the gene that encodes Histone H3.3 (H3.3). Substitution of Glycine at position 34 of H3.3 with either Arginine or Valine (H3.3G34R/V), was recently described and characterized in a large cohort of pHGG samples as occurring in 5-20% of pHGGs. Attempts to study the mechanism of H3.3G34R have proven difficult due to the lack of knowledge regarding the cell-of-origin and the requirement for co-occurring mutations for model development. We sought to develop a biologically relevant animal model of pHGG to probe the downstream effects of the H3.3G34R mutation in the context of vital co-occurring mutations. Methods We developed a genetically engineered mouse model (GEMM) that incorporates PDGF-A activation, TP53 loss and the H3.3G34R mutation both in the presence and loss of Alpha thalassemia/mental retardation syndrome X-linked (ATRX), which is commonly mutated in H3.3G34 mutant pHGGs. Results We demonstrated that ATRX loss significantly increases tumor latency in the absence of H3.3G34R and inhibits ependymal differentiation in the presence of H3.3G34R. Transcriptomic analysis revealed that ATRX loss in the context of H3.3G34R upregulates Hoxa cluster genes. We also found that the H3.3G34R overexpression leads to enrichment of neuronal markers but only in the context of ATRX loss. Conclusions This study proposes a mechanism in which ATRX loss is the major contributor to many key transcriptomic changes in H3.3G34R pHGGs. Accession number GSE197988.
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Affiliation(s)
- Aalaa S Abdallah
- Department of Pediatrics, Northwestern University, Chicago, Illinois, USA
- Stanley Manne Children’s Research Institute, Molecular and Translational Cancer Biology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA
| | - Herminio J Cardona
- Stanley Manne Children’s Research Institute, Molecular and Translational Cancer Biology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA
| | - Samantha L Gadd
- Department of Pathology, Northwestern University, Chicago, Illinois, USA
| | - Daniel J Brat
- Department of Pathology, Northwestern University, Chicago, Illinois, USA
| | - Plamena P Powla
- Department of Psychiatry and Behavioral Sciences, Northwestern University, Chicago, Illinois, USA
| | - Waleed S Alruwalli
- Department of Psychiatry and Behavioral Sciences, Northwestern University, Chicago, Illinois, USA
| | - Chen Shen
- Stanley Manne Children’s Research Institute, Molecular and Translational Cancer Biology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Xiao-Nan Li
- Department of Pediatrics, Northwestern University, Chicago, Illinois, USA
- Stanley Manne Children’s Research Institute, Molecular and Translational Cancer Biology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA
- Developmental Therapeutic Core, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Program of Precision Medicine PDOX Modeling of Pediatric Tumors, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA
| | - Oren J Becher
- Department of Pediatrics, Northwestern University, Chicago, Illinois, USA
- Stanley Manne Children’s Research Institute, Molecular and Translational Cancer Biology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA
- Department of Pediatrics, Kravis Children’s Hospital, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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8
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Shakarami F, Jahani M, Nouri Z, Tabatabaiefar MA. X-linked mental retardation-hypotonic facies syndrome: Exome sequencing identifies novel clinical characteristics associated with c.5182G>C mutation in the ATRX gene. Mol Genet Genomic Med 2022; 10:e2034. [PMID: 35962714 PMCID: PMC9544208 DOI: 10.1002/mgg3.2034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 07/15/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
Background X‐linked mental retardation‐hypotonic facies syndrome‐1 (MRXFH1), caused by a mutation in the ATRX gene, is a rare syndromic form of X‐linked mental retardation (XLMR) that is mainly characterized by severe intellectual disability, dysmorphic facies, and skewed X‐inactivation pattern in carrier women. Method In this study, due to the genetic heterogeneity of the disease, we performed exome sequencing (ES) on a 15‐year‐old boy with primary microcephaly and intellectual disability. Also, Sanger sequencing, cosegregation analysis, and structural modeling were done to identify and verify the causative variant in the proband and other affected individuals in the family. In addition, we collected data from previously reported cases to compare with our patients' phenotypes. Results ES revealed a previously reported missense variant in the ATRX gene (c.5182G > C, p.Ala1728Pro), segregating with the new clinical characteristic including primary microcephaly in the pedigree. This variant meets the criteria of being likely pathogenic based on the ACMG variant interpretation guideline. Conclusions The findings of this study extend the spectrum of phenotypes associated with the identified variant and provide further details on its clinical features.
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Affiliation(s)
- Fatemeh Shakarami
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mehdi Jahani
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Zahra Nouri
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.,Genetics Department, Erythron Pathobiology and Genetics Lab, Isfahan, Iran
| | - Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.,Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.,GenTArget Corp (GTAC), Deputy of Research and Technology, Isfahan University of Medical Sciences, Isfahan, Iran
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9
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Epigenetic genes and epilepsy - emerging mechanisms and clinical applications. Nat Rev Neurol 2022; 18:530-543. [PMID: 35859062 DOI: 10.1038/s41582-022-00693-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2022] [Indexed: 12/21/2022]
Abstract
An increasing number of epilepsies are being attributed to variants in genes with epigenetic functions. The products of these genes include factors that regulate the structure and function of chromatin and the placing, reading and removal of epigenetic marks, as well as other epigenetic processes. In this Review, we provide an overview of the various epigenetic processes, structuring our discussion around five function-based categories: DNA methylation, histone modifications, histone-DNA crosstalk, non-coding RNAs and chromatin remodelling. We provide background information on each category, describing the general mechanism by which each process leads to altered gene expression. We also highlight key clinical and mechanistic aspects, providing examples of genes that strongly associate with epilepsy within each class. We consider the practical applications of these findings, including tissue-based and biofluid-based diagnostics and precision medicine-based treatments. We conclude that variants in epigenetic genes are increasingly found to be causally involved in the epilepsies, with implications for disease mechanisms, treatments and diagnostics.
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10
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The epigenetic dysfunction underlying malignant glioma pathogenesis. J Transl Med 2022; 102:682-690. [PMID: 35152274 DOI: 10.1038/s41374-022-00741-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/12/2022] [Accepted: 01/24/2022] [Indexed: 12/12/2022] Open
Abstract
Comprehensive molecular profiling has dramatically transformed the diagnostic neuropathology of brain tumors. Diffuse gliomas, the most common and deadly brain tumor variants, are now classified by highly recurrent biomarkers instead of histomorphological characteristics. Several of the key molecular alterations driving glioma classification involve epigenetic dysregulation at a fundamental level, implicating fields of biology not previously thought to play major roles glioma pathogenesis. This article will review the major epigenetic alterations underlying malignant gliomas, their likely mechanisms of action, and potential strategies for their therapeutic targeting.
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11
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Reichard J, Zimmer-Bensch G. The Epigenome in Neurodevelopmental Disorders. Front Neurosci 2021; 15:776809. [PMID: 34803599 PMCID: PMC8595945 DOI: 10.3389/fnins.2021.776809] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 10/04/2021] [Indexed: 12/26/2022] Open
Abstract
Neurodevelopmental diseases (NDDs), such as autism spectrum disorders, epilepsy, and schizophrenia, are characterized by diverse facets of neurological and psychiatric symptoms, differing in etiology, onset and severity. Such symptoms include mental delay, cognitive and language impairments, or restrictions to adaptive and social behavior. Nevertheless, all have in common that critical milestones of brain development are disrupted, leading to functional deficits of the central nervous system and clinical manifestation in child- or adulthood. To approach how the different development-associated neuropathologies can occur and which risk factors or critical processes are involved in provoking higher susceptibility for such diseases, a detailed understanding of the mechanisms underlying proper brain formation is required. NDDs rely on deficits in neuronal identity, proportion or function, whereby a defective development of the cerebral cortex, the seat of higher cognitive functions, is implicated in numerous disorders. Such deficits can be provoked by genetic and environmental factors during corticogenesis. Thereby, epigenetic mechanisms can act as an interface between external stimuli and the genome, since they are known to be responsive to external stimuli also in cortical neurons. In line with that, DNA methylation, histone modifications/variants, ATP-dependent chromatin remodeling, as well as regulatory non-coding RNAs regulate diverse aspects of neuronal development, and alterations in epigenomic marks have been associated with NDDs of varying phenotypes. Here, we provide an overview of essential steps of mammalian corticogenesis, and discuss the role of epigenetic mechanisms assumed to contribute to pathophysiological aspects of NDDs, when being disrupted.
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Affiliation(s)
- Julia Reichard
- Functional Epigenetics in the Animal Model, Institute for Biology II, RWTH Aachen University, Aachen, Germany
- Research Training Group 2416 MultiSenses-MultiScales, Institute for Biology II, RWTH Aachen University, Aachen, Germany
| | - Geraldine Zimmer-Bensch
- Functional Epigenetics in the Animal Model, Institute for Biology II, RWTH Aachen University, Aachen, Germany
- Research Training Group 2416 MultiSenses-MultiScales, Institute for Biology II, RWTH Aachen University, Aachen, Germany
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12
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León NY, Harley VR. ATR-X syndrome: genetics, clinical spectrum, and management. Hum Genet 2021; 140:1625-1634. [PMID: 34524523 DOI: 10.1007/s00439-021-02361-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 08/30/2021] [Indexed: 12/13/2022]
Abstract
ATR-X, an acronym for alpha thalassemia and mental retardation X-linked, syndrome is a congenital condition predominantly affecting males, characterized by mild to severe intellectual disability, facial, skeletal, urogenital, and hematopoietic anomalies. Less common are heart defects, eye anomalies, renal abnormalities, and gastrointestinal dysfunction. ATR-X syndrome is caused by germline variants in the ATRX gene. Until recently, the diagnosis of the ATR-X syndrome had been guided by the classical clinical manifestations and confirmed by molecular techniques. However, our new systematic analysis shows that the only clinical sign shared by all affected individuals is intellectual disability, with the other manifestations varying even within the same family. More than 190 different germline ATRX mutations in some 200 patients have been analyzed. With improved and more frequent analysis by molecular technologies, more subtle deletions and insertions have been detected recently. Moreover, emerging technologies reveal non-classic phenotypes of ATR-X syndrome as well as the description of a new clinical feature, the development of osteosarcoma which suggests an increased cancer risk in ATR-X syndrome. This review will focus on the different types of inherited ATRX mutations and their relation to clinical features in the ATR-X syndrome. We will provide an update of the frequency of clinical manifestations, the affected organs, and the genotype-phenotype correlations. Finally, we propose a shift in the diagnosis of ATR-X patients, from a clinical diagnosis to a molecular-based approach. This may assist clinicians in patient management, risk assessment and genetic counseling.
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Affiliation(s)
- Nayla Y León
- Sex Development Laboratory, Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, 27-31 Wright Street, Melbourne, VIC, 3168, Australia.,Department of Molecular and Translational Science, Monash University, Melbourne, VIC, Australia
| | - Vincent R Harley
- Sex Development Laboratory, Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, 27-31 Wright Street, Melbourne, VIC, 3168, Australia. .,Department of Molecular and Translational Science, Monash University, Melbourne, VIC, Australia.
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13
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Chin HS, Fu NY. Physiological Functions of Mcl-1: Insights From Genetic Mouse Models. Front Cell Dev Biol 2021; 9:704547. [PMID: 34336857 PMCID: PMC8322662 DOI: 10.3389/fcell.2021.704547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/14/2021] [Indexed: 01/27/2023] Open
Abstract
The ability to regulate the survival and death of a cell is paramount throughout the lifespan of a multicellular organism. Apoptosis, a main physiological form of programmed cell death, is regulated by the Bcl-2 family proteins that are either pro-apoptotic or pro-survival. The in vivo functions of distinct Bcl-2 family members are largely unmasked by genetically engineered murine models. Mcl-1 is one of the two Bcl-2 like pro-survival genes whose germline deletion causes embryonic lethality in mice. Its requisite for the survival of a broad range of cell types has been further unraveled by using conditional and inducible deletion murine model systems in different tissues or cell lineages and at distinct developmental stages. Moreover, genetic mouse cancer models have also demonstrated that Mcl-1 is essential for the survival of multiple tumor types. The MCL-1 locus is commonly amplified across various cancer types in humans. Small molecule inhibitors with high affinity and specificity to human MCL-1 have been developed and explored for the treatment of certain cancers. To facilitate the pre-clinical studies of MCL-1 in cancer and other diseases, transgenic mouse models over-expressing human MCL-1 as well as humanized MCL-1 mouse models have been recently engineered. This review discusses the current advances in understanding the physiological roles of Mcl-1 based on studies using genetic murine models and its critical implications in pathology and treatment of human diseases.
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Affiliation(s)
- Hui San Chin
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore
| | - Nai Yang Fu
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, Singapore.,Department of Physiology, National University of Singapore, Singapore, Singapore
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14
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Rakesh R, Chanana UB, Hussain S, Sharma S, Goel K, Bisht D, Patne K, Swer PB, Hockensmith JW, Muthuswami R. Altering mammalian transcription networking with ADAADi: An inhibitor of ATP-dependent chromatin remodeling. PLoS One 2021; 16:e0251354. [PMID: 33999958 PMCID: PMC8128233 DOI: 10.1371/journal.pone.0251354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/23/2021] [Indexed: 11/30/2022] Open
Abstract
Active DNA-dependent ATPase A Domain inhibitor (ADAADi) is the only known inhibitor of ATP-dependent chromatin remodeling proteins that targets the ATPase domain of these proteins. The molecule is synthesized by aminoglycoside phosphotransferase enzyme in the presence of aminoglycosides. ADAADi interacts with ATP-dependent chromatin remodeling proteins through motif Ia present in the conserved helicase domain, and thus, can potentially inhibit all members of this family of proteins. We show that mammalian cells are sensitive to ADAADi but with variable responses in different cell lines. ADAADi can be generated from a wide variety of aminoglycosides; however, cells showed differential response to ADAADi generated from various aminoglycosides. Using HeLa and DU145 cells as model system we have explored the effect of ADAADi on cellular functions. We show that the transcriptional network of a cell type is altered when treated with sub-lethal concentration of ADAADi. Although ADAADi has no known effects on DNA chemical and structural integrity, expression of DNA-damage response genes was altered. The transcripts encoding for the pro-apoptotic proteins were found to be upregulated while the anti-apoptotic genes were found to be downregulated. This was accompanied by increased apoptosis leading us to hypothesize that the ADAADi treatment promotes apoptotic-type of cell death by upregulating the transcription of pro-apoptotic genes. ADAADi also inhibited migration of cells as well as their colony forming ability leading us to conclude that the compound has effective anti-tumor properties.
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Affiliation(s)
| | | | - Saddam Hussain
- Chromatin Remodeling Laboratory, School of Life Sciences, JNU, New Delhi, India
| | - Soni Sharma
- Chromatin Remodeling Laboratory, School of Life Sciences, JNU, New Delhi, India
| | - Kaveri Goel
- Chromatin Remodeling Laboratory, School of Life Sciences, JNU, New Delhi, India
| | - Deepa Bisht
- Chromatin Remodeling Laboratory, School of Life Sciences, JNU, New Delhi, India
| | - Ketki Patne
- Chromatin Remodeling Laboratory, School of Life Sciences, JNU, New Delhi, India
| | - Pynskhem Bok Swer
- Chromatin Remodeling Laboratory, School of Life Sciences, JNU, New Delhi, India
| | - Joel W Hockensmith
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, United States of America
| | - Rohini Muthuswami
- Chromatin Remodeling Laboratory, School of Life Sciences, JNU, New Delhi, India
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15
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Ahmed R, Sarwar S, Hu J, Cardin V, Qiu LR, Zapata G, Vandeleur L, Yan K, Lerch JP, Corbett MA, Gecz J, Picketts DJ. Transgenic mice with an R342X mutation in Phf6 display clinical features of Börjeson-Forssman-Lehmann Syndrome. Hum Mol Genet 2021; 30:575-594. [PMID: 33772537 PMCID: PMC8120135 DOI: 10.1093/hmg/ddab081] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/24/2021] [Accepted: 03/16/2021] [Indexed: 12/26/2022] Open
Abstract
The PHF6 mutation c.1024C > T; p.R342X, is a recurrent cause of Börjeson-Forssman-Lehmann Syndrome (BFLS), a neurodevelopmental disorder characterized by moderate-severe intellectual disability, truncal obesity, gynecomastia, hypogonadism, long tapering fingers and large ears (MIM#301900). Here, we generated transgenic mice with the identical substitution (R342X mice) using CRISPR technology. We show that the p.R342X mutation causes a reduction in PHF6 protein levels, in both human and mice, from nonsense-mediated decay and nonsense-associated alternative splicing, respectively. Magnetic resonance imaging studies indicated that R342X mice had a reduced brain volume on a mixed genetic background but developed hydrocephaly and a high incidence of postnatal death on a C57BL/6 background. Cortical development proceeded normally, while hippocampus and hypothalamus relative brain volumes were altered. A hypoplastic anterior pituitary was also observed that likely contributes to the small size of the R342X mice. Behavior testing demonstrated deficits in associative learning, spatial memory and an anxiolytic phenotype. Taken together, the R342X mice represent a good preclinical model of BFLS that will allow further dissection of PHF6 function and disease pathogenesis.
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Affiliation(s)
- Raies Ahmed
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
- Departments of Biochemistry, Microbiology, & Immunology, Ottawa, Ontario K1H 8M5, Canada
| | - Shihab Sarwar
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Jinghua Hu
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Valérie Cardin
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
- Cellular & Molecular Medicine, Ottawa, Ontario K1H 8M5, Canada
| | - Lily R Qiu
- Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario M5T 3H7, Canada
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Gerardo Zapata
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
- Departments of Biochemistry, Microbiology, & Immunology, Ottawa, Ontario K1H 8M5, Canada
| | - Lucianne Vandeleur
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, SA 5005, Australia
| | - Keqin Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
| | - Jason P Lerch
- Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario M5T 3H7, Canada
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Mark A Corbett
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, SA 5005, Australia
| | - Jozef Gecz
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, SA 5005, Australia
- South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
- Departments of Biochemistry, Microbiology, & Immunology, Ottawa, Ontario K1H 8M5, Canada
- Cellular & Molecular Medicine, Ottawa, Ontario K1H 8M5, Canada
- Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
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16
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Tamming RJ, Dumeaux V, Jiang Y, Shafiq S, Langlois L, Ellegood J, Qiu LR, Lerch JP, Bérubé NG. Atrx Deletion in Neurons Leads to Sexually Dimorphic Dysregulation of miR-137 and Spatial Learning and Memory Deficits. Cell Rep 2021; 31:107838. [PMID: 32610139 PMCID: PMC7326465 DOI: 10.1016/j.celrep.2020.107838] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 04/13/2020] [Accepted: 06/08/2020] [Indexed: 12/31/2022] Open
Abstract
ATRX gene mutations have been identified in syndromic and non-syndromic intellectual disabilities in humans. ATRX is known to maintain genomic stability in neuroprogenitor cells, but its function in differentiated neurons and memory processes remains largely unresolved. Here, we show that the deletion of neuronal Atrx in mice leads to distinct hippocampal structural defects, fewer presynaptic vesicles, and an enlarged postsynaptic area at CA1 apical dendrite-axon junctions. We identify male-specific impairments in long-term contextual memory and in synaptic gene expression, linked to altered miR-137 levels. We show that ATRX directly binds to the miR-137 locus and that the enrichment of the suppressive histone mark H3K27me3 is significantly reduced upon the loss of ATRX. We conclude that the ablation of ATRX in excitatory forebrain neurons leads to sexually dimorphic effects on miR-137 expression and on spatial memory, identifying a potential therapeutic target for neurological defects caused by ATRX dysfunction. Loss of ATRX in neurons has sexually dimorphic effects on long-term spatial memory Targeted deletion of neuronal ATRX in mice causes ultrastructural synaptic defects ATRX null neurons show sex-specific changes in miR-137 and target synaptic transcripts ATRX directly binds and suppresses miR-137 in males via enrichment of H3K27me3
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Affiliation(s)
- Renee J Tamming
- Children's Health Research Institute, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada; Department of Biochemistry, Western University, London, ON, Canada
| | - Vanessa Dumeaux
- Department of Paediatrics, Western University, London, ON, Canada; PERFORM Centre, Concordia University, Montreal, QC, Canada
| | - Yan Jiang
- Children's Health Research Institute, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada
| | - Sarfraz Shafiq
- Children's Health Research Institute, London, ON, Canada; Department of Paediatrics, Western University, London, ON, Canada; Department of Anatomy & Cell Biology, Western University, London, ON, Canada
| | - Luana Langlois
- Children's Health Research Institute, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada; Department of Anatomy & Cell Biology, Western University, London, ON, Canada
| | - Jacob Ellegood
- Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada
| | - Lily R Qiu
- Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada; Wellcome Centre for Integrative Neuroimaging, The University of Oxford, Oxford, UK
| | - Jason P Lerch
- Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada; Department of Medical Biophysics, The University of Toronto, Toronto, ON, Canada; Wellcome Centre for Integrative Neuroimaging, The University of Oxford, Oxford, UK
| | - Nathalie G Bérubé
- Children's Health Research Institute, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada; Department of Paediatrics, Western University, London, ON, Canada; Department of Anatomy & Cell Biology, Western University, London, ON, Canada; Department of Oncology, Western University, London, ON, Canada.
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17
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Flemmer RT, Connolly SP, Geizer BA, Opferman JT, Vanderluit JL. The Role of Mcl-1 in Embryonic Neural Precursor Cell Apoptosis. Front Cell Dev Biol 2021; 9:659531. [PMID: 33959612 PMCID: PMC8093775 DOI: 10.3389/fcell.2021.659531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/29/2021] [Indexed: 01/27/2023] Open
Abstract
Myeloid cell leukemia-1 (Mcl-1), an anti-apoptotic Bcl-2 protein, regulates neural precursor cell (NPC) survival in both the developing and adult mammalian nervous system. It is unclear when during the neurogenic period Mcl-1 becomes necessary for NPC survival and whether Bax is the sole pro-apoptotic target of Mcl-1. To address these questions, we used the nervous system-specific Nestin-Cre Mcl-1 conditional knockout mouse line (Mcl-1 CKO) to assess the anti-apoptotic role of Mcl-1 in developmental neurogenesis. Loss of Mcl-1 resulted in a wave of apoptosis beginning in the brainstem and cervical spinal cord at embryonic day 9.5 (E9.5) and in the forebrain at E10.5. Apoptosis was first observed ventrally in each region and spread dorsally over time. Within the spinal cord, apoptosis also spread in a rostral to caudal direction following the path of differentiation. Breeding the Mcl-1 CKO mouse with the Bax null mouse rescued the majority of NPC from apoptosis except in the dorsomedial brainstem and ventral thoracic spinal cord where only 50% were rescued. This demonstrates that Mcl-1 promotes NPC survival primarily by inhibiting the activation of Bax, but that Bax is not the sole pro-apoptotic target of Mcl-1 during embryonic neurogenesis. Interestingly, although co-deletion of Bax rescued the majority of NPC apoptosis, it resulted in embryonic lethality at E13, whereas conditional deletion of both Mcl-1 and Bax rescued embryonic lethality. In summary, this study demonstrates the widespread dependency on Mcl-1 during nervous system development.
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Affiliation(s)
- Robert T Flemmer
- Division of BioMedical Sciences, Memorial University, St. John's, NL, Canada
| | - Sarah P Connolly
- Division of BioMedical Sciences, Memorial University, St. John's, NL, Canada
| | - Brittany A Geizer
- Division of BioMedical Sciences, Memorial University, St. John's, NL, Canada
| | - Joseph T Opferman
- Department of Cellular and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
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18
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Timpano S, Picketts DJ. Neurodevelopmental Disorders Caused by Defective Chromatin Remodeling: Phenotypic Complexity Is Highlighted by a Review of ATRX Function. Front Genet 2020; 11:885. [PMID: 32849845 PMCID: PMC7432156 DOI: 10.3389/fgene.2020.00885] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 07/20/2020] [Indexed: 12/15/2022] Open
Abstract
The ability to determine the genetic etiology of intellectual disability (ID) and neurodevelopmental disorders (NDD) has improved immensely over the last decade. One prevailing metric from these studies is the large percentage of genes encoding epigenetic regulators, including many members of the ATP-dependent chromatin remodeling enzyme family. Chromatin remodeling proteins can be subdivided into five classes that include SWI/SNF, ISWI, CHD, INO80, and ATRX. These proteins utilize the energy from ATP hydrolysis to alter nucleosome positioning and are implicated in many cellular processes. As such, defining their precise roles and contributions to brain development and disease pathogenesis has proven to be complex. In this review, we illustrate that complexity by reviewing the roles of ATRX on genome stability, replication, and transcriptional regulation and how these mechanisms provide key insight into the phenotype of ATR-X patients.
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Affiliation(s)
- Sara Timpano
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Department of Medicine, University of Ottawa, Ottawa, ON, Canada.,University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada
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19
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Martin-Kenny N, Bérubé NG. Effects of a postnatal Atrx conditional knockout in neurons on autism-like behaviours in male and female mice. J Neurodev Disord 2020; 12:17. [PMID: 32580781 PMCID: PMC7315487 DOI: 10.1186/s11689-020-09319-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 06/04/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Alpha-thalassemia/mental retardation, X-linked, or ATRX, is an autism susceptibility gene that encodes a chromatin remodeler. Mutations of ATRX result in the ATR-X intellectual disability syndrome and have been identified in autism spectrum disorder (ASD) patients. The mechanisms by which ATRX mutations lead to autism and autistic-like behaviours are not yet known. To address this question, we generated mice with postnatal Atrx inactivation in excitatory neurons of the forebrain and performed a battery of behavioural assays that assess autistic-like behaviours. METHODS Male and female mice with a postnatal conditional ablation of ATRX were generated using the Cre/lox system under the control of the αCaMKII gene promoter. These mice were tested in a battery of behavioural tests that assess autistic-like features. We utilized paradigms that measure social behaviour, repetitive, and stereotyped behaviours, as well as sensory gating. Statistics were calculated by two-way repeated measures ANOVA with Sidak's multiple comparison test or unpaired Student's t tests as indicated. RESULTS The behaviour tests revealed no significant differences between Atrx-cKO and control mice. We identified sexually dimorphic changes in odor habituation and discrimination; however, these changes did not correlate with social deficits. CONCLUSION The postnatal knockout of Atrx in forebrain excitatory neurons does not lead to autism-related behaviours in male or female mice.
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Affiliation(s)
- Nicole Martin-Kenny
- Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Division of Genetics and Development, Children's Health Research Institute, London, Ontario, Canada
| | - Nathalie G Bérubé
- Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
- Division of Genetics and Development, Children's Health Research Institute, London, Ontario, Canada.
- Department of Oncology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
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20
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Zeineldin M, Federico S, Chen X, Fan Y, Xu B, Stewart E, Zhou X, Jeon J, Griffiths L, Nguyen R, Norrie J, Easton J, Mulder H, Yergeau D, Liu Y, Wu J, Van Ryn C, Naranjo A, Hogarty MD, Kamiński MM, Valentine M, Pruett-Miller SM, Pappo A, Zhang J, Clay MR, Bahrami A, Vogel P, Lee S, Shelat A, Sarthy JF, Meers MP, George RE, Mardis ER, Wilson RK, Henikoff S, Downing JR, Dyer MA. MYCN amplification and ATRX mutations are incompatible in neuroblastoma. Nat Commun 2020; 11:913. [PMID: 32060267 PMCID: PMC7021759 DOI: 10.1038/s41467-020-14682-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 01/23/2020] [Indexed: 12/31/2022] Open
Abstract
Aggressive cancers often have activating mutations in growth-controlling oncogenes and inactivating mutations in tumor-suppressor genes. In neuroblastoma, amplification of the MYCN oncogene and inactivation of the ATRX tumor-suppressor gene correlate with high-risk disease and poor prognosis. Here we show that ATRX mutations and MYCN amplification are mutually exclusive across all ages and stages in neuroblastoma. Using human cell lines and mouse models, we found that elevated MYCN expression and ATRX mutations are incompatible. Elevated MYCN levels promote metabolic reprogramming, mitochondrial dysfunction, reactive-oxygen species generation, and DNA-replicative stress. The combination of replicative stress caused by defects in the ATRX-histone chaperone complex, and that induced by MYCN-mediated metabolic reprogramming, leads to synthetic lethality. Therefore, ATRX and MYCN represent an unusual example, where inactivation of a tumor-suppressor gene and activation of an oncogene are incompatible. This synthetic lethality may eventually be exploited to improve outcomes for patients with high-risk neuroblastoma.
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Affiliation(s)
- Maged Zeineldin
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Sara Federico
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Xiang Chen
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- St. Jude Children's Research Hospital-Washington University Pediatric Cancer Genome Project, St. Louis, MO, USA
| | - Yiping Fan
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Beisi Xu
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Elizabeth Stewart
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Xin Zhou
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Jongrye Jeon
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Lyra Griffiths
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Rosa Nguyen
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Jackie Norrie
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - John Easton
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Heather Mulder
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Donald Yergeau
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Yanling Liu
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Jianrong Wu
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Collin Van Ryn
- Children's Oncology Group Statistics and Data Center, Department of Biostatistics, University of Florida, Gainesville, FlL, 32607, USA
| | - Arlene Naranjo
- Children's Oncology Group Statistics and Data Center, Department of Biostatistics, University of Florida, Gainesville, FlL, 32607, USA
| | - Michael D Hogarty
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Marcin M Kamiński
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Marc Valentine
- Cytogenetics Shared Resource, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Shondra M Pruett-Miller
- Center for Advanced Genome Engineering, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Alberto Pappo
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Jinghui Zhang
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Michael R Clay
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Armita Bahrami
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Peter Vogel
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Seungjae Lee
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Anang Shelat
- Department of Chemical Biology and Therapeutics St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Jay F Sarthy
- Basic Science Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
| | - Michael P Meers
- Basic Science Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
| | - Rani E George
- Department of Hematology/Oncology, Dana Farber Cancer Institute, Boston, MA, 02215, USA
| | - Elaine R Mardis
- The Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, 43205, USA
| | - Richard K Wilson
- The Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, 43205, USA
| | - Steven Henikoff
- Basic Science Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815, USA
| | - James R Downing
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Michael A Dyer
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
- St. Jude Children's Research Hospital-Washington University Pediatric Cancer Genome Project, St. Louis, MO, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815, USA.
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, 38163, USA.
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21
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Chen SH, Lu CH, Tsai MJ. TCTP is Essential for Cell Proliferation and Survival during CNS Development. Cells 2020; 9:cells9010133. [PMID: 31935927 PMCID: PMC7017002 DOI: 10.3390/cells9010133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/31/2019] [Accepted: 01/02/2020] [Indexed: 02/07/2023] Open
Abstract
Translationally controlled tumor-associated protein (TCTP) has been implicated in cell growth, proliferation, and apoptosis through interacting proteins. Although TCTP is expressed abundantly in the mouse brain, little is known regarding its role in the neurogenesis of the nervous system. We used Nestin-cre-driven gene-mutated mice to investigate the function of TCTP in the nervous system. The mice carrying disrupted TCTP in neuronal and glial progenitor cells died at the perinatal stage. The NestinCre/+; TCTPf/f pups displayed reduced body size at postnatal day 0.5 (P0.5) and a lack of milk in the stomach compared with littermate controls. In addition to decreased cell proliferation, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) and caspase assay revealed that apoptosis was increased in newly committed TCTP-disrupted cells as they migrated away from the ventricular zone. The mechanism may be that the phenotype from specific deletion of TCTP in neural progenitor cells is correlated with the decreased expression of cyclins D2, E2, Mcl-1, Bcl-xL, hax-1, and Octamer-binding transcription factor 4 (Oct4) in conditional knockout mice. Our results demonstrate that TCTP is a critical protein for cell survival during early neuronal and glial differentiation. Thus, enhanced neuronal loss and functional defect in Tuj1 and doublecortin-positive neurons mediated through increased apoptosis and decreased proliferation during central nervous system (CNS) development may contribute to the perinatal death of TCTP mutant mice.
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Affiliation(s)
- Sung-Ho Chen
- Department of Pharmacology, College of Medicine, Tzu Chi University, Hualien 97004, Taiwan
- Master Program in Pharmacology and Toxicology, College of Medicine, Tzu Chi University, Hualien 97004, Taiwan;
- Correspondence: ; Tel.: +886-3-8565301 (ext. 2452); Fax: +886-3-8561465
| | - Chin-Hung Lu
- Master Program in Pharmacology and Toxicology, College of Medicine, Tzu Chi University, Hualien 97004, Taiwan;
| | - Ming-Jen Tsai
- Department of Emergency Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 600, Taiwan;
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22
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Lovejoy CA, Takai K, Huh MS, Picketts DJ, de Lange T. ATRX affects the repair of telomeric DSBs by promoting cohesion and a DAXX-dependent activity. PLoS Biol 2020; 18:e3000594. [PMID: 31895940 PMCID: PMC6959610 DOI: 10.1371/journal.pbio.3000594] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/14/2020] [Accepted: 12/19/2019] [Indexed: 12/20/2022] Open
Abstract
Alpha thalassemia/mental retardation syndrome X-linked chromatin remodeler (ATRX), a DAXX (death domain-associated protein) interacting protein, is often lost in cells using the alternative lengthening of telomeres (ALT) pathway, but it is not known how ATRX loss leads to ALT. We report that ATRX deletion from mouse cells altered the repair of telomeric double-strand breaks (DSBs) and induced ALT-like phenotypes, including ALT-associated promyelocytic leukemia (PML) bodies (APBs), telomere sister chromatid exchanges (T-SCEs), and extrachromosomal telomeric signals (ECTSs). Mechanistically, we show that ATRX affects telomeric DSB repair by promoting cohesion of sister telomeres and that loss of ATRX in ALT cells results in diminished telomere cohesion. In addition, we document a role for DAXX in the repair of telomeric DSBs. Removal of telomeric cohesion in combination with DAXX deficiency recapitulates all telomeric DSB repair phenotypes associated with ATRX loss. The data reveal that ATRX has an effect on telomeric DSB repair and that this role involves both telomere cohesion and a DAXX-dependent pathway.
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Affiliation(s)
- Courtney A. Lovejoy
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, New York, United States of America
| | - Kaori Takai
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, New York, United States of America
| | - Michael S. Huh
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - David J. Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 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
| | - Titia de Lange
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, New York, United States of America
- * E-mail:
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23
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Mahmud I, Liao D. DAXX in cancer: phenomena, processes, mechanisms and regulation. Nucleic Acids Res 2019; 47:7734-7752. [PMID: 31350900 PMCID: PMC6735914 DOI: 10.1093/nar/gkz634] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/05/2019] [Accepted: 07/12/2019] [Indexed: 12/13/2022] Open
Abstract
DAXX displays complex biological functions. Remarkably, DAXX overexpression is a common feature in diverse cancers, which correlates with tumorigenesis, disease progression and treatment resistance. Structurally, DAXX is modular with an N-terminal helical bundle, a docking site for many DAXX interactors (e.g. p53 and ATRX). DAXX's central region folds with the H3.3/H4 dimer, providing a H3.3-specific chaperoning function. DAXX has two functionally critical SUMO-interacting motifs. These modules are connected by disordered regions. DAXX's structural features provide a framework for deciphering how DAXX mechanistically imparts its functions and how its activity is regulated. DAXX modulates transcription through binding to transcription factors, epigenetic modifiers, and chromatin remodelers. DAXX's localization in the PML nuclear bodies also plays roles in transcriptional regulation. DAXX-regulated genes are likely important effectors of its biological functions. Deposition of H3.3 and its interactions with epigenetic modifiers are likely key events for DAXX to regulate transcription, DNA repair, and viral infection. Interactions between DAXX and its partners directly impact apoptosis and cell signaling. DAXX's activity is regulated by posttranslational modifications and ubiquitin-dependent degradation. Notably, the tumor suppressor SPOP promotes DAXX degradation in phase-separated droplets. We summarize here our current understanding of DAXX's complex functions with a focus on how it promotes oncogenesis.
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Affiliation(s)
- Iqbal Mahmud
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, 1333 Center Drive, Gainesville, FL 32610-0235, USA
| | - Daiqing Liao
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, 1333 Center Drive, Gainesville, FL 32610-0235, USA
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24
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Marano D, Fioriniello S, Fiorillo F, Gibbons RJ, D'Esposito M, Della Ragione F. ATRX Contributes to MeCP2-Mediated Pericentric Heterochromatin Organization during Neural Differentiation. Int J Mol Sci 2019; 20:E5371. [PMID: 31671722 PMCID: PMC6862095 DOI: 10.3390/ijms20215371] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 10/24/2019] [Indexed: 11/16/2022] Open
Abstract
Methyl-CpG binding protein 2 (MeCP2) is a multi-function factor involved in locus-specific transcriptional modulation and the regulation of genome architecture, e.g., pericentric heterochromatin (PCH) organization. MECP2 mutations are responsible for Rett syndrome (RTT), a devastating postnatal neurodevelopmental disorder, the pathogenetic mechanisms of which are still unknown. MeCP2, together with Alpha-thalassemia/mental retardation syndrome X-linked protein (ATRX), accumulates at chromocenters, which are repressive PCH domains. As with MECP2, mutations in ATRX cause ATR-X syndrome which is associated with severe intellectual disability. We exploited two murine embryonic stem cell lines, in which the expression of MeCP2 or ATRX is abolished. Through immunostaining, chromatin immunoprecipitation and western blot, we show that MeCP2 and ATRX are reciprocally dependent both for their expression and targeting to chromocenters. Moreover, ATRX plays a role in the accumulation of members of the heterochromatin protein 1 (HP1) family at PCH and, as MeCP2, modulates their expression. Furthermore, ATRX and HP1 targeting to chromocenters depends on an RNA component. 3D-DNA fluorescence in situ hybridization (FISH) highlighted, for the first time, a contribution of ATRX in MeCP2-mediated chromocenter clustering during neural differentiation. Overall, we provide a detailed dissection of the functional interplay between MeCP2 and ATRX in higher-order PCH organization in neurons. Our findings suggest molecular defects common to RTT and ATR-X syndrome, including an alteration in PCH.
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Affiliation(s)
- Domenico Marano
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
| | - Salvatore Fioriniello
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
| | - Francesca Fiorillo
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
| | - Richard J Gibbons
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
| | - Maurizio D'Esposito
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
| | - Floriana Della Ragione
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
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25
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Alvarez-Saavedra M, Yan K, De Repentigny Y, Hashem LE, Chaudary N, Sarwar S, Yang D, Ioshikhes I, Kothary R, Hirayama T, Yagi T, Picketts DJ. Snf2h Drives Chromatin Remodeling to Prime Upper Layer Cortical Neuron Development. Front Mol Neurosci 2019; 12:243. [PMID: 31680852 PMCID: PMC6811508 DOI: 10.3389/fnmol.2019.00243] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 09/20/2019] [Indexed: 01/23/2023] Open
Abstract
Alterations in the homeostasis of either cortical progenitor pool, namely the apically located radial glial (RG) cells or the basal intermediate progenitors (IPCs) can severely impair cortical neuron production. Such changes are reflected by microcephaly and are often associated with cognitive defects. Genes encoding epigenetic regulators are a frequent cause of intellectual disability and many have been shown to regulate progenitor cell growth, including our inactivation of the Smarca1 gene encoding Snf2l, which is one of two ISWI mammalian orthologs. Loss of the Snf2l protein resulted in dysregulation of Foxg1 and IPC proliferation leading to macrocephaly. Here we show that inactivation of the closely related Smarca5 gene encoding the Snf2h chromatin remodeler is necessary for embryonic IPC expansion and subsequent specification of callosal projection neurons. Telencephalon-specific Smarca5 cKO embryos have impaired cell cycle kinetics and increased cell death, resulting in fewer Tbr2+ and FoxG1+ IPCs by mid-neurogenesis. These deficits give rise to adult mice with a dramatic reduction in Satb2+ upper layer neurons, and partial agenesis of the corpus callosum. Mice survive into adulthood but molecularly display reduced expression of the clustered protocadherin genes that may further contribute to altered dendritic arborization and a hyperactive behavioral phenotype. Our studies provide novel insight into the developmental function of Snf2h-dependent chromatin remodeling processes during brain development.
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Affiliation(s)
- Matías Alvarez-Saavedra
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Keqin Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Yves De Repentigny
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Lukas E Hashem
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Nidhi Chaudary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Shihab Sarwar
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Doo Yang
- Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Ilya Ioshikhes
- Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Rashmi Kothary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Teruyoshi Hirayama
- KOKORO-Biology Group, Integrated Biology Laboratories, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,Department of Anatomy and Developmental Neurobiology, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Takeshi Yagi
- KOKORO-Biology Group, Integrated Biology Laboratories, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
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26
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Shastrula PK, Sierra I, Deng Z, Keeney F, Hayden JE, Lieberman PM, Janicki SM. PML is recruited to heterochromatin during S phase and represses DAXX-mediated histone H3.3 chromatin assembly. J Cell Sci 2019; 132:jcs.220970. [PMID: 30796101 DOI: 10.1242/jcs.220970] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 02/09/2019] [Indexed: 12/18/2022] Open
Abstract
The incorporation of the histone H3 variant, H3.3, into chromatin by the H3.3-specific chaperone DAXX and the ATP-dependent chromatin remodeling factor ATRX is a critical mechanism for silencing repetitive DNA. DAXX and ATRX are also components of promyelocytic nuclear bodies (PML-NBs), which have been identified as sites of H3.3 chromatin assembly. Here, we use a transgene array that can be visualized in single living cells to investigate the mechanisms that recruit PML-NB proteins (i.e. PML, DAXX, ATRX, and SUMO-1, SUMO-2 and SUMO-3) to heterochromatin and their functions in H3.3 chromatin assembly. We show that DAXX and PML are recruited to the array through distinct SUMOylation-dependent mechanisms. Additionally, PML is recruited during S phase and its depletion increases H3.3 deposition. Since this effect is abrogated when PML and DAXX are co-depleted, it is likely that PML represses DAXX-mediated H3.3 chromatin assembly. Taken together, these results suggest that, at heterochromatin, PML-NBs coordinate H3.3 chromatin assembly with DNA replication, which has important implications for understanding how transcriptional silencing is established and maintained.
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Affiliation(s)
- Prashanth Krishna Shastrula
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA.,University of the Sciences in Philadelphia, Department of Biological Sciences, 600 South 43rd Street, Philadelphia, PA 19104, USA
| | - Isabel Sierra
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Zhong Deng
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Frederick Keeney
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - James E Hayden
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Paul M Lieberman
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Susan M Janicki
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
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27
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Optogenetic Stimulation Enhanced Neuronal Plasticities in Motor Recovery after Ischemic Stroke. Neural Plast 2019; 2019:5271573. [PMID: 31007684 PMCID: PMC6441501 DOI: 10.1155/2019/5271573] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 01/01/2019] [Accepted: 01/20/2019] [Indexed: 12/16/2022] Open
Abstract
Motor capability recovery after ischemic stroke involves dynamic remodeling processes of neural connectomes in the nervous system. Various neuromodulatory strategies combining direct stimulating interventions with behavioral trainings for motor recovery after ischemic stroke have been developed. However, the effectiveness of these interventions varies widely due to unspecific activation or inhibition of undefined neuronal subtypes. Optogenetics is a functional and structural connection-based approach that can selectively activate or inhibit specific subtype neurons with a higher precision, and it has been widely applied to build up neuronal plasticities of the nervous system, which shows a great potential in restoring motor functions in stroke animal models. Here, we reviewed neurobiological mechanisms of enhanced brain plasticities underlying motor recovery through the optogenetic stimulation after ischemic stroke. Several brain sites and neural circuits that have been previously proven effective for motor function rehabilitation were identified, which would be helpful for a more schematic understanding of effective neuronal connectomes in the motor function recovery after ischemic stroke.
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28
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Wang Y, Yang J, Wild AT, Wu WH, Shah R, Danussi C, Riggins GJ, Kannan K, Sulman EP, Chan TA, Huse JT. G-quadruplex DNA drives genomic instability and represents a targetable molecular abnormality in ATRX-deficient malignant glioma. Nat Commun 2019; 10:943. [PMID: 30808951 PMCID: PMC6391399 DOI: 10.1038/s41467-019-08905-8] [Citation(s) in RCA: 117] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 02/08/2019] [Indexed: 12/11/2022] Open
Abstract
Mutational inactivation of ATRX (α-thalassemia mental retardation X-linked) represents a defining molecular alteration in large subsets of malignant glioma. Yet the pathogenic consequences of ATRX deficiency remain unclear, as do tractable mechanisms for its therapeutic targeting. Here we report that ATRX loss in isogenic glioma model systems induces replication stress and DNA damage by way of G-quadruplex (G4) DNA secondary structure. Moreover, these effects are associated with the acquisition of disease-relevant copy number alterations over time. We then demonstrate, both in vitro and in vivo, that ATRX deficiency selectively enhances DNA damage and cell death following chemical G4 stabilization. Finally, we show that G4 stabilization synergizes with other DNA-damaging therapies, including ionizing radiation, in the ATRX-deficient context. Our findings reveal novel pathogenic mechanisms driven by ATRX deficiency in glioma, while also pointing to tangible strategies for drug development. ATRX deficiency is linked to genomic stability in cancer cells. Here, the authors show that ATRX inactivation induces G-quadruplex formation, leading to genome-wide DNA damage, and the use of G-quadruplex stabilisers can be exploited therapeutically in ATRX deficient gliomas.
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Affiliation(s)
- Yuxiang Wang
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Jie Yang
- Department of Radation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Aaron T Wild
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Wei H Wu
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Rachna Shah
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Carla Danussi
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Gregory J Riggins
- Departments of Neurosurgery, Oncology, and Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD, 21231, USA
| | - Kasthuri Kannan
- Department of Pathology, New York University School of Medicine, New York, NY, 10016, USA
| | - Erik P Sulman
- Department of Radation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Timothy A Chan
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA.,Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Jason T Huse
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA. .,Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
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29
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Glial ensheathment of the somatodendritic compartment regulates sensory neuron structure and activity. Proc Natl Acad Sci U S A 2019; 116:5126-5134. [PMID: 30804200 DOI: 10.1073/pnas.1814456116] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Sensory neurons perceive environmental cues and are important of organismal survival. Peripheral sensory neurons interact intimately with glial cells. While the function of axonal ensheathment by glia is well studied, less is known about the functional significance of glial interaction with the somatodendritic compartment of neurons. Herein, we show that three distinct glia cell types differentially wrap around the axonal and somatodendritic surface of the polymodal dendritic arborization (da) neuron of the Drosophila peripheral nervous system for detection of thermal, mechanical, and light stimuli. We find that glial cell-specific loss of the chromatin modifier gene dATRX in the subperineurial glial layer leads to selective elimination of somatodendritic glial ensheathment, thus allowing us to investigate the function of such ensheathment. We find that somatodendritic glial ensheathment regulates the morphology of the dendritic arbor, as well as the activity of the sensory neuron, in response to sensory stimuli. Additionally, glial ensheathment of the neuronal soma influences dendritic regeneration after injury.
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30
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CTCF Governs the Identity and Migration of MGE-Derived Cortical Interneurons. J Neurosci 2018; 39:177-192. [PMID: 30377227 DOI: 10.1523/jneurosci.3496-17.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 10/12/2018] [Accepted: 10/12/2018] [Indexed: 12/13/2022] Open
Abstract
The CCCTC-binding factor (CTCF) is a central regulator of chromatin topology recently linked to neurodevelopmental disorders such as intellectual disability, autism, and schizophrenia. The aim of this study was to identify novel roles of CTCF in the developing mouse brain. We provide evidence that CTCF is required for the expression of the LIM homeodomain factor LHX6 involved in fate determination of cortical interneurons (CINs) that originate in the medial ganglionic eminence (MGE). Conditional Ctcf ablation in the MGE of mice of either sex leads to delayed tangential migration, abnormal distribution of CIN in the neocortex, a marked reduction of CINs expressing parvalbumin and somatostatin (Sst), and an increased number of MGE-derived cells expressing Lhx8 and other markers of basal forebrain projection neurons. Likewise, Ctcf-null MGE cells transplanted into the cortex of wild-type hosts generate fewer Sst-expressing CINs and exhibit lamination defects that are efficiently rescued upon reexpression of LHX6. Collectively, these data indicate that CTCF regulates the dichotomy between Lhx6 and Lhx8 to achieve correct specification and migration of MGE-derived CINs.SIGNIFICANCE STATEMENT This work provides evidence that CCCTC-binding factor (CTCF) controls an early fate decision point in the generation of cortical interneurons mediated at least in part by Lhx6. Importantly, the abnormalities described could reflect early molecular and cellular events that contribute to human neurological disorders previously linked to CTCF, including schizophrenia, autism, and intellectual disability.
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31
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Wasylishen AR, Estrella JS, Pant V, Chau GP, Lozano G. Daxx Functions Are p53-Independent In Vivo. Mol Cancer Res 2018; 16:1523-1529. [PMID: 29903771 PMCID: PMC6233723 DOI: 10.1158/1541-7786.mcr-18-0281] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/02/2018] [Accepted: 05/31/2018] [Indexed: 02/03/2023]
Abstract
Mutations in the death domain-associated protein (DAXX) have been recently identified in a substantial proportion of human pancreatic neuroendocrine tumors (PanNETs). Remarkably, however, little is known about the physiologic role(s) of DAXX despite in vitro studies suggesting potential functions. Most prominently, and supported by tumor sequencing data, DAXX functions in concert with alpha thalassemia/mental retardation X-linked (ATRX) as a histone chaperone complex for the H3.3 variant. Studies have also identified potential roles in apoptosis, transcription, and negative regulation of the p53 tumor suppressor pathway. Herein, a mouse modeling approach was used to specifically address the latter and no significant genetic interaction between Daxx and the p53 pathway was determined. The embryonic lethal phenotype of Daxx loss is not p53-dependent. In addition, Daxx heterozygosity does not sensitize mice to a sublethal dose of ionizing radiation or alter the survival or tumor phenotype of Mdm2 transgenic mice. However, the data support a tumor suppressor role for DAXX as low-dose ionizing radiation produced a higher proportion of carcinomas in Daxx heterozygous mice than wild-type controls.Implications: While DAXX has important in vivo functions, they are independent of an inhibitory role on the p53 tumor suppressor pathway. Mol Cancer Res; 16(10); 1523-9. ©2018 AACR.
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Affiliation(s)
- Amanda R. Wasylishen
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| | - Jeannelyn S. Estrella
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| | - Vinod Pant
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| | - Gilda P. Chau
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| | - Guillermina Lozano
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America,Corresponding author: Guillermina Lozano, The University of Texas MD Anderson Cancer Center, Department of Genetics, 1515 Holcombe Blvd, Unit 1010, Houston, TX 77030, , Phone: 713-834-6386, Fax: 713-834-6380
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Young CC, Baker RM, Howlett CJ, Hryciw T, Herman JE, Higgs D, Gibbons R, Crawford H, Brown A, Pin CL. The Loss of ATRX Increases Susceptibility to Pancreatic Injury and Oncogenic KRAS in Female But Not Male Mice. Cell Mol Gastroenterol Hepatol 2018; 7:93-113. [PMID: 30510993 PMCID: PMC6260375 DOI: 10.1016/j.jcmgh.2018.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 09/06/2018] [Indexed: 02/09/2023]
Abstract
Background Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in North America, accounting for >30,000 deaths annually. Although somatic activating mutations in KRAS appear in 97% of PDAC patients, additional factors are required to initiate PDAC. Because mutations in genes encoding chromatin remodelling proteins have been implicated in KRAS-mediated PDAC, we investigated whether loss of chromatin remodeler ɑ-thalassemia, mental-retardation, X-linked (ATRX) affects oncogenic KRAS's ability to promote PDAC. ATRX affects DNA replication, repair, and gene expression and is implicated in other cancers including glioblastomas and pancreatic neuroendocrine tumors. The hypothesis was that deletion of Atrx in pancreatic acinar cells will increase susceptibility to injury and oncogenic KRAS. Methods Mice allowing conditional loss of Atrx within pancreatic acinar cells were examined after induction of recurrent cerulein-induced pancreatitis or oncogenic KRAS (KRASG12D ). Histologic, biochemical, and molecular analysis examined pancreatic pathologies up to 2 months after induction of Atrx deletion. Results Mice lacking Atrx showed more progressive damage, inflammation, and acinar-to-duct cell metaplasia in response to injury relative to wild-type mice. In combination with KRASG12D, Atrx-deficient acinar cells showed increased fibrosis, inflammation, progression to acinar-to-duct cell metaplasia, and pre-cancerous lesions relative to mice expressing only KRASG12D. This sensitivity appears only in female mice, mimicking a significant prevalence of ATRX mutations in human female PDAC patients. Conclusions Our results indicate the absence of ATRX increases sensitivity to injury and oncogenic KRAS only in female mice. This is an instance of a sex-specific mutation that enhances oncogenic KRAS's ability to promote pancreatic intraepithelial lesion formation.
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Key Words
- ADM, acinar-to-duct cell metaplasia
- ANOVA, analysis of variance
- ATRX, ɑ-thalassemia, mental-retardation, X-linked
- CIP, cerulein induced pancreatitis
- CPA, carboxypeptidase
- DAXX, death associated protein 6
- EZH2, Enhancer of Zeste Homologue 2, MKA, Mist1creERT/+KrasLSL-G12D/+AtrxflΔ18
- Epigenetics
- MIST1
- PDAC, pancreatic ductal adenocarcinoma
- PanIN, pancreatic intraepithelial lesion
- Pancreatic Ductal Adenocarcinoma
- SOX9
- WT, wild-type
- ds, double stranded
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Affiliation(s)
- Claire C Young
- Department of Paediatrics, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada; Department of Oncology, University of Western Ontario, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada
| | - Ryan M Baker
- Department of Paediatrics, University of Western Ontario, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada
| | - Christopher J Howlett
- Department of Pathology and Laboratory Medicine, University of Western Ontario, London, Ontario, Canada
| | - Todd Hryciw
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada; Robarts Research Institute, London, Ontario, Canada
| | | | - Douglas Higgs
- MRC Molecular Haematology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, United Kingdom
| | - Richard Gibbons
- MRC Molecular Haematology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, United Kingdom
| | - Howard Crawford
- Molecular & Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Arthur Brown
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada; Robarts Research Institute, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada
| | - Christopher L Pin
- Department of Paediatrics, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada; Department of Oncology, University of Western Ontario, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada.
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33
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Integrated genetic and epigenetic analysis of myxofibrosarcoma. Nat Commun 2018; 9:2765. [PMID: 30018380 PMCID: PMC6050269 DOI: 10.1038/s41467-018-03891-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 03/20/2018] [Indexed: 12/27/2022] Open
Abstract
Myxofibrosarcoma (MFS) is a common adult soft tissue sarcoma characterized by an infiltrative growth pattern and a high local recurrence rate. Here we report the genetic and epigenetic landscape of MFS based on the results of whole-exome sequencing (N = 41), RNA sequencing (N = 29), and methylation analysis (N = 41), using 41 MFSs as a discovery set, and subsequent targeted sequencing of 140 genes in the entire cohort of 99 MFSs and 17 MFSs' data from TCGA. Fourteen driver genes are identified, including potentially actionable therapeutic targets seen in 37% of cases. There are frequent alterations in p53 signaling (51%) and cell cycle checkpoint genes (43%). Other conceivably actionable driver genes including ATRX, JAK1, NF1, NTRK1, and novel oncogenic BRAF fusion gene are identified. Methylation patterns cluster into three subtypes associated with unique combinations of driver mutations, clinical outcomes, and immune cell compositions. Our results provide a valuable genomic resource to enable the design of precision medicine for MFS. Myxofibrosarcoma occurs in adults and is associated with high local relapse. Here, based on exome/transcriptome sequencing and DNA methylation analysis, the authors identify driver genes and methylation clusters associated with unique combinations of mutations, outcomes, and immune cell compositions.
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Haase S, Garcia-Fabiani MB, Carney S, Altshuler D, Núñez FJ, Méndez FM, Núñez F, Lowenstein PR, Castro MG. Mutant ATRX: uncovering a new therapeutic target for glioma. Expert Opin Ther Targets 2018; 22:599-613. [PMID: 29889582 PMCID: PMC6044414 DOI: 10.1080/14728222.2018.1487953] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/08/2018] [Indexed: 12/29/2022]
Abstract
INTRODUCTION ATRX is a chromatin remodeling protein whose main function is the deposition of the histone variant H3.3. ATRX mutations are widely distributed in glioma, and correlate with alternative lengthening of telomeres (ALT) development, but they also affect other cellular functions related to epigenetic regulation. Areas covered: We discuss the main molecular characteristics of ATRX, from its various functions in normal development to the effects of its loss in ATRX syndrome patients and animal models. We focus on the salient consequences of ATRX mutations in cancer, from a clinical to a molecular point of view, focusing on both adult and pediatric glioma. Finally, we will discuss the therapeutic opportunities future research perspectives. Expert opinion: ATRX is a major component of various essential cellular pathways, exceeding its functions as a histone chaperone (e.g. DNA replication and repair, chromatin higher-order structure regulation, gene transcriptional regulation, etc.). However, it is unclear how the loss of these functions in ATRX-null cancer cells affects cancer development and progression. We anticipate new treatments and clinical approaches will emerge for glioma and other cancer types as mechanistic and molecular studies on ATRX are only just beginning to reveal the many critical functions of this protein in cancer.
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Affiliation(s)
- Santiago Haase
- a Department of Neurosurgery , The University of Michigan School of Medicine , Ann Arbor , MI , USA
- b Department of Cell & Developmental Biology , The University of Michigan School of Medicine , Ann Arbor , MI , USA
| | - María Belén Garcia-Fabiani
- a Department of Neurosurgery , The University of Michigan School of Medicine , Ann Arbor , MI , USA
- b Department of Cell & Developmental Biology , The University of Michigan School of Medicine , Ann Arbor , MI , USA
| | - Stephen Carney
- a Department of Neurosurgery , The University of Michigan School of Medicine , Ann Arbor , MI , USA
- b Department of Cell & Developmental Biology , The University of Michigan School of Medicine , Ann Arbor , MI , USA
| | - David Altshuler
- a Department of Neurosurgery , The University of Michigan School of Medicine , Ann Arbor , MI , USA
- b Department of Cell & Developmental Biology , The University of Michigan School of Medicine , Ann Arbor , MI , USA
| | - Felipe J Núñez
- a Department of Neurosurgery , The University of Michigan School of Medicine , Ann Arbor , MI , USA
- b Department of Cell & Developmental Biology , The University of Michigan School of Medicine , Ann Arbor , MI , USA
| | - Flor M Méndez
- a Department of Neurosurgery , The University of Michigan School of Medicine , Ann Arbor , MI , USA
- b Department of Cell & Developmental Biology , The University of Michigan School of Medicine , Ann Arbor , MI , USA
| | - Fernando Núñez
- a Department of Neurosurgery , The University of Michigan School of Medicine , Ann Arbor , MI , USA
- b Department of Cell & Developmental Biology , The University of Michigan School of Medicine , Ann Arbor , MI , USA
| | - Pedro R Lowenstein
- a Department of Neurosurgery , The University of Michigan School of Medicine , Ann Arbor , MI , USA
- b Department of Cell & Developmental Biology , The University of Michigan School of Medicine , Ann Arbor , MI , USA
| | - Maria G Castro
- a Department of Neurosurgery , The University of Michigan School of Medicine , Ann Arbor , MI , USA
- b Department of Cell & Developmental Biology , The University of Michigan School of Medicine , Ann Arbor , MI , USA
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Rowland ME, Jiang Y, Beier F, Bérubé NG. Inactivation of hepatic ATRX in Atrx Foxg1cre mice prevents reversal of aging-like phenotypes by thyroxine. Aging (Albany NY) 2018; 10:1223-1238. [PMID: 29883366 PMCID: PMC6046231 DOI: 10.18632/aging.101462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/30/2018] [Indexed: 11/25/2022]
Abstract
ATRX is an ATP-dependent chromatin remodeler required for the maintenance of genomic integrity. We previously reported that conditional Atrx ablation in the mouse embryonic forebrain and anterior pituitary using the Foxg1cre driver causes reduced health and lifespan. In these mice, premature aging-like phenotypes were accompanied by low circulating levels of insulin-like growth factor 1 (IGF-1) and thyroxine (T4), hormones that maintain stem cell pools and normal metabolic profiles, respectively. Based on emerging evidence that T4 stimulates expression of IGF-1 in pre-pubertal mice, we tested whether T4 supplementation in Atrx Foxg1cre mice could restore IGF-1 levels and ameliorate premature aging-like phenotypes. Despite restoration of normal serum T4 levels, we did not observe improvements in circulating IGF-1. In the liver, thyroid hormone target genes were differentially affected upon T4 treatment, with Igf1 and several other thyroid hormone responsive genes failing to recover normal expression levels. These findings hinted at Cre-mediated Atrx inactivation in the liver of Atrx Foxg1cre mice, which we confirmed. We conclude that the phenotypes observed in the Atrx Foxg1cre mice can be explained in part by a role of ATRX in the liver to promote T4-mediated Igf1 expression, thus explaining the inefficacy of T4 therapy observed in this study.
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Affiliation(s)
- Megan E Rowland
- Departments of Paediatrics and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.,Children's Health Research Institute, London, ON, Canada
| | - Yan Jiang
- Departments of Paediatrics and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.,Children's Health Research Institute, London, ON, Canada
| | - Frank Beier
- Children's Health Research Institute, London, ON, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.,Western Bone and Joint Institute, Western University, London, ON, Canada
| | - Nathalie G Bérubé
- Departments of Paediatrics and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.,Children's Health Research Institute, London, ON, Canada
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36
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Atrx inactivation drives disease-defining phenotypes in glioma cells of origin through global epigenomic remodeling. Nat Commun 2018. [PMID: 29535300 PMCID: PMC5849741 DOI: 10.1038/s41467-018-03476-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Mutational inactivation of the SWI/SNF chromatin regulator ATRX occurs frequently in gliomas, the most common primary brain tumors. Whether and how ATRX deficiency promotes oncogenesis by epigenomic dysregulation remains unclear, despite its recent implication in both genomic instability and telomere dysfunction. Here we report that Atrx loss recapitulates characteristic disease phenotypes and molecular features in putative glioma cells of origin, inducing cellular motility although also shifting differentiation state and potential toward an astrocytic rather than neuronal histiogenic profile. Moreover, Atrx deficiency drives widespread shifts in chromatin accessibility, histone composition, and transcription in a distribution almost entirely restricted to genomic sites normally bound by the protein. Finally, direct gene targets of Atrx that mediate specific Atrx-deficient phenotypes in vitro exhibit similarly selective misexpression in ATRX-mutant human gliomas. These findings demonstrate that ATRX deficiency and its epigenomic sequelae are sufficient to induce disease-defining oncogenic phenotypes in appropriate cellular and molecular contexts. ATRX inactivation frequently occurs in glioma. Here, the authors explore the role of ATRX inactivation in oncogenesis, highlighting ATRX deficiency driven epigenomic changes that influence the expression of genes crucial to the oncogenic phenotype.
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37
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Epigenetic Etiology of Intellectual Disability. J Neurosci 2017; 37:10773-10782. [PMID: 29118205 DOI: 10.1523/jneurosci.1840-17.2017] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/26/2017] [Accepted: 09/26/2017] [Indexed: 12/31/2022] Open
Abstract
Intellectual disability (ID) is a prevailing neurodevelopmental condition associated with impaired cognitive and adaptive behaviors. Many chromatin-modifying enzymes and other epigenetic regulators have been genetically associated with ID disorders (IDDs). Here we review how alterations in the function of histone modifiers, chromatin remodelers, and methyl-DNA binding proteins contribute to neurodevelopmental defects and altered brain plasticity. We also discuss how progress in human genetics has led to the generation of mouse models that unveil the molecular etiology of ID, and outline the direction in which this field is moving to identify therapeutic strategies for IDDs. Importantly, because the chromatin regulators linked to IDDs often target common downstream genes and cellular processes, the impact of research in individual syndromes goes well beyond each syndrome and can also contribute to the understanding and therapy of other IDDs. Furthermore, the investigation of these disorders helps us to understand the role of chromatin regulators in brain development, plasticity, and gene expression, thereby answering fundamental questions in neurobiology.
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38
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Huh MS, Young KG, Yan K, Price-O’Dea T, Picketts DJ. Recovery from impaired muscle growth arises from prolonged postnatal accretion of myonuclei in Atrx mutant mice. PLoS One 2017; 12:e0186989. [PMID: 29095838 PMCID: PMC5667798 DOI: 10.1371/journal.pone.0186989] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 10/11/2017] [Indexed: 01/13/2023] Open
Abstract
Reduced muscle mass due to pathological development can occur through several mechanisms, including the loss or reduced proliferation of muscle stem cells. Muscle-specific ablation of the α-thalassemia mental retardation syndrome mutant protein, Atrx, in transgenic mice results in animals with a severely reduced muscle mass at three weeks of age; yet this muscle mass reduction resolves by adult age. Here, we explore the cellular mechanism underlying this effect. Analysis of Atrx mutant mice included testing for grip strength and rotorod performance. Muscle fiber length, fiber volume and numbers of myofiber-associated nuclei were determined from individual EDL or soleus myofibers isolated at three, five, or eight weeks. Myofibers from three week old Atrx mutant mice are smaller with fewer myofiber-associated nuclei and reduced volume compared to control animals, despite similar fiber numbers. Nonetheless, the grip strength of Atrx mutant mice was comparable to control mice when adjusted for body weight. Myofiber volume remained smaller at five weeks, becoming comparable to controls by 8 weeks of age. Concomitantly, increased numbers of myofiber-associated nuclei and Ki67+ myoblasts indicated that the recovery of muscle mass likely arises from the prolonged accretion of new myonuclei. This suggests that under disease conditions the muscle satellite stem cell niche can remain in a prolonged active state, allowing for the addition of a minimum number of myonuclei required to achieve a normal muscle size.
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Affiliation(s)
- Michael S. Huh
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON Canada
| | - Kevin G. Young
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON Canada
| | - Keqin Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON Canada
| | - Tina Price-O’Dea
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON Canada
| | - David J. Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON Canada
- Department of Biochemistry, Microbiology & Immunology, University of Ottawa, Ottawa, ON Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON Canada
- * E-mail:
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Hoelper D, Huang H, Jain AY, Patel DJ, Lewis PW. Structural and mechanistic insights into ATRX-dependent and -independent functions of the histone chaperone DAXX. Nat Commun 2017; 8:1193. [PMID: 29084956 PMCID: PMC5662737 DOI: 10.1038/s41467-017-01206-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 08/29/2017] [Indexed: 12/20/2022] Open
Abstract
The ATRX–DAXX histone chaperone complex incorporates the histone variant H3.3 at heterochromatic regions in a replication-independent manner. Here, we present a high-resolution x-ray crystal structure of an interaction surface between ATRX and DAXX. We use single amino acid substitutions in DAXX that abrogate formation of the complex to explore ATRX-dependent and ATRX-independent functions of DAXX. We find that the repression of specific murine endogenous retroviruses is dependent on DAXX, but not on ATRX. In support, we reveal the existence of two biochemically distinct DAXX-containing complexes: the ATRX–DAXX complex involved in gene repression and telomere chromatin structure, and a DAXX–SETDB1–KAP1–HDAC1 complex that represses endogenous retroviruses independently of ATRX and H3.3 incorporation into chromatin. We find that histone H3.3 stabilizes DAXX protein levels and can affect DAXX-regulated gene expression without incorporation into nucleosomes. Our study demonstrates a nucleosome-independent function for the H3.3 histone variant. The ATRX-DAXX histone chaperone complex incorporates H3.3 in heterochromatin in a replication-independent manner. Here, the authors present a high-resolution x-ray crystal structure of an interaction surface between ATRX and DAXX, and characterize ATRX-dependent and-independent functions of DAXX.
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Affiliation(s)
- Dominik Hoelper
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53706, USA.,Wisconsin Institute for Discovery, University of Wisconsin, Madison, WI, 53715, USA
| | - Hongda Huang
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA.,Department of Biology, South University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Aayushi Y Jain
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53706, USA.,Wisconsin Institute for Discovery, University of Wisconsin, Madison, WI, 53715, USA
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Peter W Lewis
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53706, USA. .,Wisconsin Institute for Discovery, University of Wisconsin, Madison, WI, 53715, USA.
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Nandakumar P, Mansouri A, Das S. The Role of ATRX in Glioma Biology. Front Oncol 2017; 7:236. [PMID: 29034211 PMCID: PMC5626857 DOI: 10.3389/fonc.2017.00236] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/14/2017] [Indexed: 02/03/2023] Open
Abstract
The current World Health Organization classification of CNS tumors has made a tremendous leap from past editions by incorporating molecular criteria in addition to the pre-existing histological parameters. The revised version has had a particular impact on the classification of diffuse low-grade gliomas and their high-grade variants. The ATRX status is one of the critical markers that define the molecular classification of gliomas. In this review, we will first provide an overview of the role of ATRX in regular cell biology. Furthermore, the role of ATRX in tumorigenesis, specifically gliomas, is comprehensively elucidated. The possible correlation of ATRX status with other genetic/epigenetic modifications is also presented. We conclude by discussing some of the challenges associated with incorporating ATRX status assessment into routine clinical practice while also exploring opportunities for future diagnostics/therapeutics in gliomas based on ATRX status.
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Affiliation(s)
- Pravanya Nandakumar
- Division of Neurosurgery, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada
| | - Alireza Mansouri
- Center for Cancer Research, Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States.,Division of Neuro-Oncology, Johns Hopkins University, Baltimore, MD, United States
| | - Sunit Das
- Division of Neurosurgery, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada.,The Arthur and Sonia Labatt Brain Tumour Centre, Hospital for Sick Kids, University of Toronto, Toronto, ON, Canada
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41
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Dyer MA, Qadeer ZA, Valle-Garcia D, Bernstein E. ATRX and DAXX: Mechanisms and Mutations. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a026567. [PMID: 28062559 DOI: 10.1101/cshperspect.a026567] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recent genome sequencing efforts in a variety of cancers have revealed mutations and/or structural alterations in ATRX and DAXX, which together encode a complex that deposits histone variant H3.3 into repetitive heterochromatin. These regions include retrotransposons, pericentric heterochromatin, and telomeres, the latter of which show deregulation in ATRX/DAXX-mutant tumors. Interestingly, ATRX and DAXX mutations are often found in pediatric tumors, suggesting a particular developmental context in which these mutations drive disease. Here we review the functions of ATRX and DAXX in chromatin regulation as well as their potential contributions to tumorigenesis. We place emphasis on the chromatin remodeler ATRX, which is mutated in the developmental disorder for which it is named, α-thalassemia, mental retardation, X-linked syndrome, and at high frequency in a number of adult and pediatric tumors.
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Affiliation(s)
- Michael A Dyer
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
| | - Zulekha A Qadeer
- Departments of Oncological Sciences and Dermatology, Icahn School of Medicine at Mount Sinai, New York, New York 10029.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - David Valle-Garcia
- Departments of Oncological Sciences and Dermatology, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Emily Bernstein
- Departments of Oncological Sciences and Dermatology, Icahn School of Medicine at Mount Sinai, New York, New York 10029.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029
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42
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Tamming RJ, Siu JR, Jiang Y, Prado MAM, Beier F, Bérubé NG. Mosaic expression of Atrx in the mouse central nervous system causes memory deficits. Dis Model Mech 2017; 10:119-126. [PMID: 28093507 PMCID: PMC5312007 DOI: 10.1242/dmm.027482] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 12/07/2016] [Indexed: 01/01/2023] Open
Abstract
The rapid modulation of chromatin organization is thought to play a crucial role in cognitive processes such as memory consolidation. This is supported in part by the dysregulation of many chromatin-remodelling proteins in neurodevelopmental and psychiatric disorders. A key example is ATRX, an X-linked gene commonly mutated in individuals with syndromic and nonsyndromic intellectual disability. The consequences of Atrx inactivation for learning and memory have been difficult to evaluate because of the early lethality of hemizygous-null animals. In this study, we evaluated the outcome of brain-specific Atrx deletion in heterozygous female mice. These mice exhibit a mosaic pattern of ATRX protein expression in the central nervous system attributable to the location of the gene on the X chromosome. Although the hemizygous male mice die soon after birth, heterozygous females survive to adulthood. Body growth is stunted in these animals, and they have low circulating concentrations of insulin growth factor 1. In addition, they are impaired in spatial, contextual fear and novel object recognition memory. Our findings demonstrate that mosaic loss of ATRX expression in the central nervous system leads to endocrine defects and decreased body size and has a negative impact on learning and memory.
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Affiliation(s)
- Renee J Tamming
- Division of Genetics and Development, Children's Health Research Institute, London, Ontario N6C 2V5, Canada.,Departments of Paediatrics, Biochemistry and Oncology, Schulich School of Medicine and Dentistry, the University of Western Ontario, Victoria Research Laboratories, London, Ontario N6A 3K7, Canada
| | - Jennifer R Siu
- Division of Genetics and Development, Children's Health Research Institute, London, Ontario N6C 2V5, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, the University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Yan Jiang
- Division of Genetics and Development, Children's Health Research Institute, London, Ontario N6C 2V5, Canada.,Departments of Paediatrics, Biochemistry and Oncology, Schulich School of Medicine and Dentistry, the University of Western Ontario, Victoria Research Laboratories, London, Ontario N6A 3K7, Canada
| | - Marco A M Prado
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, the University of Western Ontario, London, Ontario N6A 3K7, Canada.,Department of Anatomy and Cell Biology and Robarts Research Institute, the University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Frank Beier
- Division of Genetics and Development, Children's Health Research Institute, London, Ontario N6C 2V5, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, the University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Nathalie G Bérubé
- Division of Genetics and Development, Children's Health Research Institute, London, Ontario N6C 2V5, Canada .,Departments of Paediatrics, Biochemistry and Oncology, Schulich School of Medicine and Dentistry, the University of Western Ontario, Victoria Research Laboratories, London, Ontario N6A 3K7, Canada
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Koschmann C, Calinescu AA, Nunez FJ, Mackay A, Fazal-Salom J, Thomas D, Mendez F, Kamran N, Dzaman M, Mulpuri L, Krasinkiewicz J, Doherty R, Lemons R, Brosnan-Cashman JA, Li Y, Roh S, Zhao L, Appelman H, Ferguson D, Gorbunova V, Meeker A, Jones C, Lowenstein PR, Castro MG. ATRX loss promotes tumor growth and impairs nonhomologous end joining DNA repair in glioma. Sci Transl Med 2016; 8:328ra28. [PMID: 26936505 DOI: 10.1126/scitranslmed.aac8228] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Recent work in human glioblastoma (GBM) has documented recurrent mutations in the histone chaperone protein ATRX. We developed an animal model of ATRX-deficient GBM and showed that loss of ATRX reduces median survival and increases genetic instability. Further, analysis of genome-wide data for human gliomas showed that ATRX mutation is associated with increased mutation rate at the single-nucleotide variant (SNV) level. In mouse tumors, ATRX deficiency impairs nonhomologous end joining and increases sensitivity to DNA-damaging agents that induce double-stranded DNA breaks. We propose that ATRX loss results in a genetically unstable tumor, which is more aggressive when left untreated but is more responsive to double-stranded DNA-damaging agents, resulting in improved overall survival.
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Affiliation(s)
- Carl Koschmann
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA. Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Anda-Alexandra Calinescu
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Felipe J Nunez
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Alan Mackay
- Divisions of Molecular Pathology and Cancer Therapeutics, Institute of Cancer Research, London SM2 5NG, UK
| | - Janet Fazal-Salom
- Divisions of Molecular Pathology and Cancer Therapeutics, Institute of Cancer Research, London SM2 5NG, UK
| | - Daniel Thomas
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Flor Mendez
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Neha Kamran
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Marta Dzaman
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Lakshman Mulpuri
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Johnathon Krasinkiewicz
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Robert Doherty
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Rosemary Lemons
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | | | - Youping Li
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Soyeon Roh
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Lili Zhao
- Department of Biostatistics, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Henry Appelman
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - David Ferguson
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Vera Gorbunova
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Alan Meeker
- Departments of Pathology and Urology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Chris Jones
- Divisions of Molecular Pathology and Cancer Therapeutics, Institute of Cancer Research, London SM2 5NG, UK
| | - Pedro R Lowenstein
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Maria G Castro
- Departments of Neurosurgery and Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA.
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44
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Huh MS, Ivanochko D, Hashem LE, Curtin M, Delorme M, Goodall E, Yan K, Picketts DJ. Stalled replication forks within heterochromatin require ATRX for protection. Cell Death Dis 2016; 7:e2220. [PMID: 27171262 PMCID: PMC4917659 DOI: 10.1038/cddis.2016.121] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/04/2016] [Accepted: 04/08/2016] [Indexed: 01/04/2023]
Abstract
Expansive growth of neural progenitor cells (NPCs) is a prerequisite to the temporal waves of neuronal differentiation that generate the six-layered neocortex, while also placing a heavy burden on proteins that regulate chromatin packaging and genome integrity. This problem is further reflected by the growing number of developmental disorders caused by mutations in chromatin regulators. ATRX gene mutations cause a severe intellectual disability disorder (α-thalassemia mental retardation X-linked (ATRX) syndrome; OMIM no. 301040), characterized by microcephaly, urogenital abnormalities and α-thalassemia. Although the ATRX protein is required for the maintenance of repetitive DNA within heterochromatin, how this translates to disease pathogenesis remain poorly understood and was a focus of this study. We demonstrate that Atrx(FoxG1Cre) forebrain-specific conditional knockout mice display poly(ADP-ribose) polymerase-1 (Parp-1) hyperactivation during neurogenesis and generate fewer late-born Cux1- and Brn2-positive neurons that accounts for the reduced cortical size. Moreover, DNA damage, induced Parp-1 and Atm activation is elevated in progenitor cells and contributes to their increased level of cell death. ATRX-null HeLa cells are similarly sensitive to hydroxyurea-induced replication stress, accumulate DNA damage and proliferate poorly. Impaired BRCA1-RAD51 colocalization and PARP-1 hyperactivation indicated that stalled replication forks are not efficiently protected. DNA fiber assays confirmed that MRE11 degradation of stalled replication forks was rampant in the absence of ATRX or DAXX. Indeed, fork degradation in ATRX-null cells could be attenuated by treatment with the MRE11 inhibitor mirin, or exacerbated by inhibiting PARP-1 activity. Taken together, these results suggest that ATRX is required to limit replication stress during cellular proliferation, whereas upregulation of PARP-1 activity functions as a compensatory mechanism to protect stalled forks, limiting genomic damage, and facilitating late-born neuron production.
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Affiliation(s)
- M S Huh
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - D Ivanochko
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - L E Hashem
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - M Curtin
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - M Delorme
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - E Goodall
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - K Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - D J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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45
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Carmichael ST, Kathirvelu B, Schweppe CA, Nie EH. Molecular, cellular and functional events in axonal sprouting after stroke. Exp Neurol 2016; 287:384-394. [PMID: 26874223 DOI: 10.1016/j.expneurol.2016.02.007] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 02/06/2016] [Accepted: 02/09/2016] [Indexed: 01/26/2023]
Abstract
Stroke is the leading cause of adult disability. Yet there is a limited degree of recovery in this disease. One of the mechanisms of recovery is the formation of new connections in the brain and spinal cord after stroke: post-stroke axonal sprouting. Studies indicate that post-stroke axonal sprouting occurs in mice, rats, primates and humans. Inducing post-stroke axonal sprouting in specific connections enhances recovery; blocking axonal sprouting impairs recovery. Behavioral activity patterns after stroke modify the axonal sprouting response. A unique regenerative molecular program mediates this aspect of tissue repair in the CNS. The types of connections that are formed after stroke indicate three patterns of axonal sprouting after stroke: reactive, reparative and unbounded axonal sprouting. These differ in mechanism, location, relationship to behavioral recovery and, importantly, in their prospect for therapeutic manipulation to enhance tissue repair.
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Affiliation(s)
- S Thomas Carmichael
- Departments of Neurology and of Neurobiology, David Geffen School of Medicine at UCLA, 710 Westwood Plaza, Los Angeles, CA 90095, USA.
| | - Balachandar Kathirvelu
- Departments of Neurology and of Neurobiology, David Geffen School of Medicine at UCLA, 710 Westwood Plaza, Los Angeles, CA 90095, USA.
| | - Catherine A Schweppe
- Departments of Neurology and of Neurobiology, David Geffen School of Medicine at UCLA, 710 Westwood Plaza, Los Angeles, CA 90095, USA.
| | - Esther H Nie
- Departments of Neurology and of Neurobiology, David Geffen School of Medicine at UCLA, 710 Westwood Plaza, Los Angeles, CA 90095, USA.
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46
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Abstract
Genetic causes for human disorders are being discovered at an unprecedented pace. A growing subclass of disease-causing mutations involves changes in the epigenome or in the abundance and activity of proteins that regulate chromatin structure. This article focuses on research that has uncovered human diseases that stem from such epigenetic deregulation. Disease may be caused by direct changes in epigenetic marks, such as DNA methylation, commonly found to affect imprinted gene regulation. Also described are disease-causing genetic mutations in epigenetic modifiers that either affect chromatin in trans or have a cis effect in altering chromatin configuration.
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Affiliation(s)
- Huda Y Zoghbi
- Howard Hughes Medical Institute, Baylor College of Medicine, and Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
| | - Arthur L Beaudet
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
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47
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Dennis D, Picketts D, Slack RS, Schuurmans C. Forebrain neurogenesis: From embryo to adult. TRENDS IN DEVELOPMENTAL BIOLOGY 2016; 9:77-90. [PMID: 28367004 PMCID: PMC5373848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A satellite symposium to the Canadian Developmental Biology Conference 2016 was held on March 16-17, 2016 in Banff, Alberta, Canada, entitled Forebrain Neurogenesis: From embryo to adult. The Forebrain Neurogenesis symposium was a focused, high-intensity meeting, bringing together the top Canadian and international researchers in the field. This symposium reported the latest breaking news, along with 'state of the art' techniques to answer fundamental questions in developmental neurobiology. Topics covered ranged from stem cell regulation to neurocircuitry development, culminating with a session focused on neuropsychiatric disorders. Understanding the underlying causes of neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD) is of great interest as diagnoses of these conditions are climbing at alarming rates. For instance, in 2012, the Centers for Disease Control reported that the prevalence rate of ASD in the U.S. was 1 in 88; while more recent data indicate that the number is as high as 1 in 68 (Centers for Disease Control and Prevention MMWR Surveillance Summaries. Vol. 63. No. 2). Similarly, the incidence of ASD is on the rise in Canada, increasing from 1 in 150 in 2000 to 1 in 63 in 2012 in southeastern Ontario (Centers for Disease Control and Prevention). Currently very little is known regarding the deficits underlying these neurodevelopmental conditions. Moreover, the development of effective therapies is further limited by major gaps in our understanding of the fundamental processes that regulate forebrain development and adult neurogenesis. The Forebrain Neurogenesis satellite symposium was thus timely, and it played a key role in advancing research in this important field, while also fostering collaborations between international leaders, and inspiring young researchers.
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Affiliation(s)
- Daniel Dennis
- Department of Biochemistry and Molecular Biology, Hotchkiss Brain Institute (HBI), Alberta Children's Hospital Research Institute (ACHRI), University of Calgary, Calgary, Alberta
| | - David Picketts
- Ottawa Hospital Research Institute, Ottawa, Ontario; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario
| | - Ruth S Slack
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario
| | - Carol Schuurmans
- Department of Biochemistry and Molecular Biology, Hotchkiss Brain Institute (HBI), Alberta Children's Hospital Research Institute (ACHRI), University of Calgary, Calgary, Alberta; Sunnybrook Research Institute, Biological Sciences, Toronto, Ontario, Canada
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48
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Shioda N, Fukunaga K. [Molecular mechanisms of synapse pathology in ATR-X syndrome]. Nihon Yakurigaku Zasshi 2015; 145:174-7. [PMID: 25864826 DOI: 10.1254/fpj.145.174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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49
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ATRX tolerates activity-dependent histone H3 methyl/phos switching to maintain repetitive element silencing in neurons. Proc Natl Acad Sci U S A 2014; 112:6820-7. [PMID: 25538301 DOI: 10.1073/pnas.1411258112] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
ATRX (the alpha thalassemia/mental retardation syndrome X-linked protein) is a member of the switch2/sucrose nonfermentable2 (SWI2/SNF2) family of chromatin-remodeling proteins and primarily functions at heterochromatic loci via its recognition of "repressive" histone modifications [e.g., histone H3 lysine 9 tri-methylation (H3K9me3)]. Despite significant roles for ATRX during normal neural development, as well as its relationship to human disease, ATRX function in the central nervous system is not well understood. Here, we describe ATRX's ability to recognize an activity-dependent combinatorial histone modification, histone H3 lysine 9 tri-methylation/serine 10 phosphorylation (H3K9me3S10ph), in postmitotic neurons. In neurons, this "methyl/phos" switch occurs exclusively after periods of stimulation and is highly enriched at heterochromatic repeats associated with centromeres. Using a multifaceted approach, we reveal that H3K9me3S10ph-bound Atrx represses noncoding transcription of centromeric minor satellite sequences during instances of heightened activity. Our results indicate an essential interaction between ATRX and a previously uncharacterized histone modification in the central nervous system and suggest a potential role for abnormal repetitive element transcription in pathological states manifested by ATRX dysfunction.
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50
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Ritchie K, Watson LA, Davidson B, Jiang Y, Bérubé NG. ATRX is required for maintenance of the neuroprogenitor cell pool in the embryonic mouse brain. Biol Open 2014; 3:1158-63. [PMID: 25395668 PMCID: PMC4265753 DOI: 10.1242/bio.20148730] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mutations in the alpha-thalassemia mental retardation X-linked (ATRX) gene cause a spectrum of abnormalities including intellectual disability, developmental delay, seizures, and microcephaly. The ATRX protein is highly enriched at heterochromatic repetitive sequences adjacent to the centromere, and ATRX depletion results in chromosome congression, segregation, and cohesion defects. Here, we show that Cre-mediated inactivation of Atrx in the embryonic mouse (Mus musculus) brain results in expansion of cerebral cortical layer VI, and a concurrent thinning of layers II–IV. We observed increased cell cycle exit during early-mid neurogenesis, and a depletion of apical progenitors by late neurogenesis in the Atrx-null neocortex, explaining the disproportionate layering. Premature differentiation was associated with an increased generation of outer radial glia (oRG) and TBR2-expressing basal progenitors, as well as increased generation of early-born post-mitotic projection neurons. Atrx deletion also reduced the fidelity of mitotic spindle orientation in apical progenitors, where mutant cells were often oriented at non-parallel angles of division relative to the ventricular surface. We conclude that ATRX is required for correct lamination of the mouse neocortex by regulating the timing of neuroprogenitor cell differentiation.
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Affiliation(s)
- Kieran Ritchie
- Departments of Paediatrics and Biochemistry, Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, 800 Commissioners Road East, London, ON N6C 2V5, Canada
| | - L Ashley Watson
- Departments of Paediatrics and Biochemistry, Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, 800 Commissioners Road East, London, ON N6C 2V5, Canada
| | - Benjamin Davidson
- Departments of Paediatrics and Biochemistry, Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, 800 Commissioners Road East, London, ON N6C 2V5, Canada
| | - Yan Jiang
- Departments of Paediatrics and Biochemistry, Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, 800 Commissioners Road East, London, ON N6C 2V5, Canada
| | - Nathalie G Bérubé
- Departments of Paediatrics and Biochemistry, Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, 800 Commissioners Road East, London, ON N6C 2V5, Canada
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