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Aughey G, Cali E, Maroofian R, Zaki MS, Pagnamenta AT, Rahman F, Menzies L, Shafique A, Suri M, Roze E, Aguennouz M, Ghizlane Z, Saadi SM, Ali Z, Abdulllah U, Cheema HA, Anjum MN, Morel G, McFarland R, Altunoglu U, Kraus V, Shoukier M, Murphy D, Flemming K, Yttervik H, Rhouda H, Lesca G, Murtaza BN, Rehman MU, Consortium GE, Seo GH, Beetz C, Kayserili H, Krioulie Y, Chung WK, Naz S, Maqbool S, Gleeson J, Baig SM, Efthymiou S, Taylor JC, Severino M, Jepson JE, Houlden H. Clinical and neurogenetic characterisation of autosomal recessive RBL2-associated progressive neurodevelopmental disorder. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.03.24306631. [PMID: 38746364 PMCID: PMC11092723 DOI: 10.1101/2024.05.03.24306631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Retinoblastoma (RB) proteins are highly conserved transcriptional regulators that play important roles during development by regulating cell-cycle gene expression. RBL2 dysfunction has been linked to a severe neurodevelopmental disorder. However, to date, clinical features have only been described in six individuals carrying five biallelic predicted loss of function (pLOF) variants. To define the phenotypic effects of RBL2 mutations in detail, we identified and clinically characterized a cohort of 28 patients from 18 families carrying LOF variants in RBL2 , including fourteen new variants that substantially broaden the molecular spectrum. The clinical presentation of affected individuals is characterized by a range of neurological and developmental abnormalities. Global developmental delay and intellectual disability were uniformly observed, ranging from moderate to profound and involving lack of acquisition of key motor and speech milestones in most patients. Frequent features included postnatal microcephaly, infantile hypotonia, aggressive behaviour, stereotypic movements and non-specific dysmorphic features. Common neuroimaging features were cerebral atrophy, white matter volume loss, corpus callosum hypoplasia and cerebellar atrophy. In parallel, we used the fruit fly, Drosophila melanogaster , to investigate how disruption of the conserved RBL2 orthologueue Rbf impacts nervous system function and development. We found that Drosophila Rbf LOF mutants recapitulate several features of patients harboring RBL2 variants, including alterations in the head and brain morphology reminiscent of microcephaly, and perturbed locomotor behaviour. Surprisingly, in addition to its known role in controlling tissue growth during development, we find that continued Rbf expression is also required in fully differentiated post-mitotic neurons for normal locomotion in Drosophila , and that adult-stage neuronal re-expression of Rbf is sufficient to rescue Rbf mutant locomotor defects. Taken together, this study provides a clinical and experimental basis to understand genotype-phenotype correlations in an RBL2 -linked neurodevelopmental disorder and suggests that restoring RBL2 expression through gene therapy approaches may ameliorate aspects of RBL2 LOF patient symptoms.
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2
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Chen J, Xia P, Liu Y, Kogan C, Cheng Z. Loss of Rbl2 (Retinoblastoma-Like 2) Exacerbates Myocardial Ischemia/Reperfusion Injury. J Am Heart Assoc 2022; 11:e024764. [PMID: 36129061 DOI: 10.1161/jaha.121.024764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background The postmitotic state of adult cardiomyocytes, maintained by the cell cycle repressor Rbl2 (retinoblastoma-like 2), is associated with considerable resistance to apoptosis. However, whether Rbl2 regulates cardiomyocyte apoptosis remains unknown. Methods and Results Here, we show that ablation of Rbl2 increased cardiomyocyte apoptosis following acute myocardial ischemia/reperfusion injury, leading to diminished cardiac function and exaggerated ventricular remodeling in the long term. Mechanistically, ischemia/reperfusion induced expression of the proapoptotic protein BCL2 interacting protein 3 (Bnip3), which was augmented by deletion of Rbl2. Because the Bnip3 promoter contains an adenoviral early region 2 binding factor (E2F)-binding site, we further showed that loss of Rbl2 upregulated the transcriptional activator E2F1 but downregulated the transcriptional repressor E2F4. In cultured cardiomyocytes, treatment with H2O2 markedly increased the levels of E2F1 and Bnip3, resulting in mitochondrial depolarization and apoptosis. Depletion of Rbl2 significantly augmented H2O2-induced mitochondrial damage and apoptosis in vitro. Conclusions Rbl2 deficiency enhanced E2F1-mediated Bnip3 expression, resulting in aggravated cardiomyocyte apoptosis and ischemia/reperfusion injury. Our results uncover a novel antiapoptotic role for Rbl2 in cardiomyocytes, suggesting that the cell cycle machinery may directly regulate apoptosis in postmitotic cardiomyocytes. These findings may be exploited to develop new strategies to limit ischemia/reperfusion injury in the treatment of acute myocardial infarction.
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Affiliation(s)
- Jingrui Chen
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
| | - Peng Xia
- Department of Pharmaceutical Sciences Washington State University Spokane Washington.,Cardiovascular Research Center, Department of Medicine Massachusetts General Hospital, Harvard Medical School Boston Massachusetts
| | - Yuening Liu
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
| | - Clark Kogan
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
| | - Zhaokang Cheng
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
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3
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Rips J, Abu-Libdeh B, Koplewitz BZ, Kehat-Ophir S, Frenkel S, Elpeleg O, Harel T. Orbital nodular fasciitis in child with biallelic germline RBL2 variant. Eur J Med Genet 2022; 65:104513. [PMID: 35487417 DOI: 10.1016/j.ejmg.2022.104513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 04/23/2022] [Indexed: 11/17/2022]
Abstract
RBL2/p130 is one of three highly conserved members of the retinoblastoma (RB) protein family. It is strongly upregulated during neuronal differentiation and brain development, and is critical for survival of post-mitotic neurons. Similar to RB1, it has been implicated as a tumor suppressor gene and has been shown to be dysregulated in various types of cancer. Recent publications describe biallelic, germline loss of function variants in RBL2 in individuals with profound developmental delay. We report a child with profound developmental delay, microcephaly, and hypotonia, who developed fulminant exophthalmos at age 6 years. Brain MRI followed by a biopsy of an intra-orbital mass revealed a mesenchymal tumor. Post-surgical histopathologic examination of the resected tumor was compatible with diagnosis of nodular fasciitis. Exome sequencing from peripheral blood identified a biallelic frameshift variant (c.901dupT) in RBL2. Notably, no malignancies were reported in previous cases with RBL2 variants. This case provides a possible association between RBL2 and orbital tumors.
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Affiliation(s)
- Jonathan Rips
- Department of Genetics, Hadassah Medical Organization, Jerusalem, Israel
| | - Bassam Abu-Libdeh
- Department of Pediatrics & Genetics, Makassed Hospital, Al-Quds Medical School, E. Jerusalem, Palestine
| | - Benjamin Z Koplewitz
- Department of Radiology, Hadassah Medical Organization, Jerusalem, Israel; Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shay Kehat-Ophir
- Division of Ophthalmology, Hadassah Medical Organization, Jerusalem, Israel
| | - Shahar Frenkel
- Division of Ophthalmology, Hadassah Medical Organization, Jerusalem, Israel; Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Orly Elpeleg
- Department of Genetics, Hadassah Medical Organization, Jerusalem, Israel; Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tamar Harel
- Department of Genetics, Hadassah Medical Organization, Jerusalem, Israel; Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.
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4
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A Mutant Variant of E2F4 Triggers Multifactorial Therapeutic Effects in 5xFAD Mice. Mol Neurobiol 2022; 59:3016-3039. [PMID: 35254651 PMCID: PMC9016056 DOI: 10.1007/s12035-022-02764-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/28/2022] [Indexed: 11/25/2022]
Abstract
Alzheimer’s disease (AD) has a complex etiology, which requires a multifactorial approach for an efficient treatment. We have focused on E2 factor 4 (E2F4), a transcription factor that regulates cell quiescence and tissue homeostasis, controls gene networks affected in AD, and is upregulated in the brains of Alzheimer’s patients and of APPswe/PS1dE9 and 5xFAD transgenic mice. E2F4 contains an evolutionarily conserved Thr-motif that, when phosphorylated, modulates its activity, thus constituting a potential target for intervention. In this study, we generated a knock-in mouse strain with neuronal expression of a mouse E2F4 variant lacking this Thr-motif (E2F4DN), which was mated with 5xFAD mice. Here, we show that neuronal expression of E2F4DN in 5xFAD mice potentiates a transcriptional program consistent with the attenuation of the immune response and brain homeostasis. This correlates with reduced microgliosis and astrogliosis, modulation of amyloid-β peptide proteostasis, and blocking of neuronal tetraploidization. Moreover, E2F4DN prevents cognitive impairment and body weight loss, a known somatic alteration associated with AD. We also show that our finding is significant for AD, since E2F4 is expressed in cortical neurons from Alzheimer patients in association with Thr-specific phosphorylation, as evidenced by an anti-E2F4/anti-phosphoThr proximity ligation assay. We propose E2F4DN-based gene therapy as a promising multifactorial approach against AD.
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5
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López-Sánchez N, Garrido-García A, Ramón-Landreau M, Cano-Daganzo V, Frade JM. E2F4-Based Gene Therapy Mitigates the Phenotype of the Alzheimer's Disease Mouse Model 5xFAD. Neurotherapeutics 2021; 18:2484-2503. [PMID: 34766258 PMCID: PMC8804140 DOI: 10.1007/s13311-021-01151-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2021] [Indexed: 12/16/2022] Open
Abstract
After decades of unfruitful work, no effective therapies are available for Alzheimer's disease (AD), likely due to its complex etiology that requires a multifactorial therapeutic approach. We have recently shown using transgenic mice that E2 factor 4 (E2F4), a transcription factor that regulates cell quiescence and tissue homeostasis, and controls gene networks affected in AD, represents a good candidate for a multifactorial targeting of AD. Here we show that the expression of a dominant negative form of human E2F4 (hE2F4DN), unable to become phosphorylated in a Thr-conserved motif known to modulate E2F4 activity, is an effective and safe AD multifactorial therapeutic agent. Neuronal expression of hE2F4DN in homozygous 5xFAD (h5xFAD) mice after systemic administration of an AAV.PHP.B-hSyn1.hE2F4DN vector reduced the production and accumulation of Aβ in the hippocampus, attenuated reactive astrocytosis and microgliosis, abolished neuronal tetraploidization, and prevented cognitive impairment evaluated by Y-maze and Morris water maze, without triggering side effects. This treatment also reversed other alterations observed in h5xFAD mice such as paw-clasping behavior and body weight loss. Our results indicate that E2F4DN-based gene therapy is a promising therapeutic approach against AD.
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Affiliation(s)
- Noelia López-Sánchez
- Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute, 28002, Madrid, Spain
| | - Alberto Garrido-García
- Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute, 28002, Madrid, Spain
| | - Morgan Ramón-Landreau
- Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute, 28002, Madrid, Spain
| | - Vanesa Cano-Daganzo
- Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute, 28002, Madrid, Spain
| | - José M Frade
- Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute, 28002, Madrid, Spain.
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6
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Zhang S, Fu F, Zhen L, Li R, Liao C. Alteration of long non-coding RNAs and mRNAs expression profiles by compound heterozygous ASXL3 mutations in the mouse brain. Bioengineered 2021; 12:6935-6951. [PMID: 34559584 PMCID: PMC8806560 DOI: 10.1080/21655979.2021.1974811] [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] [Indexed: 01/11/2023] Open
Abstract
Compound mutations in the additional sex combs-like 3 (ASXL3) gene greatly impact the expression of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in mouse myocardial tissues. Little is known about ASXL3 mutation effects on lncRNAs and mRNAs expression in the cerebrum and cerebellum. This study aims to clarify this point using quantitative real-time polymerase chain reaction and Western blotting. Transcriptome analysis based on RNA-seq followed by bioinformatics analysis were used to compare lncRNA and mRNA expression profiles. Cell proliferation, cell cycle progression, and apoptosis were evaluated after silencing of ASXL3 expression using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4- sulfophenyl)-2 H-tetrazolium method and flow cytometry. Results showed that ASXL3 gene expression was decreased in the cerebrum and cerebellum of mice with ASXL3 P723R*P1817A mutations. We identified 319 lncRNAs and 252 mRNAs differentially expressed in the cerebrum of ASXL3 P723R*P1817A mutant mice. In the cerebellum of ASXL3 P723R*P1817A mutant mice, 5330 lncRNAs and 2204 mRNAs were differentially expressed. Differentially expressed lncRNAs and mRNAs were widely distributed across the mouse genome and were associated with various biological processes and pathways. ASXL3 silencing by siRNA transfection affected the proliferation, cell cycle progression, and apoptosis of neural cells. Therefore, the ASXL3 P723R*P1817A mutations greatly modify the lncRNA and mRNA expression profiles in the mouse cerebrum and cerebellum.
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Affiliation(s)
- Songhui Zhang
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China.,Department of Obstetrics, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.,Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - Fang Fu
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - Li Zhen
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - Ru Li
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - Can Liao
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou, China
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7
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Demyanenko S, Sharifulina S. The Role of Post-Translational Acetylation and Deacetylation of Signaling Proteins and Transcription Factors after Cerebral Ischemia: Facts and Hypotheses. Int J Mol Sci 2021; 22:ijms22157947. [PMID: 34360712 PMCID: PMC8348732 DOI: 10.3390/ijms22157947] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023] Open
Abstract
Histone deacetylase (HDAC) and histone acetyltransferase (HAT) regulate transcription and the most important functions of cells by acetylating/deacetylating histones and non-histone proteins. These proteins are involved in cell survival and death, replication, DNA repair, the cell cycle, and cell responses to stress and aging. HDAC/HAT balance in cells affects gene expression and cell signaling. There are very few studies on the effects of stroke on non-histone protein acetylation/deacetylation in brain cells. HDAC inhibitors have been shown to be effective in protecting the brain from ischemic damage. However, the role of different HDAC isoforms in the survival and death of brain cells after stroke is still controversial. HAT/HDAC activity depends on the acetylation site and the acetylation/deacetylation of the main proteins (c-Myc, E2F1, p53, ERK1/2, Akt) considered in this review, that are involved in the regulation of cell fate decisions. Our review aims to analyze the possible role of the acetylation/deacetylation of transcription factors and signaling proteins involved in the regulation of survival and death in cerebral ischemia.
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Affiliation(s)
- Svetlana Demyanenko
- Laboratory of Molecular Neurobiology, Academy of Biology and Biotechnology, Southern Federal University, pr. Stachki 194/1, 344090 Rostov-on-Don, Russia
| | - Svetlana Sharifulina
- Laboratory of Molecular Neurobiology, Academy of Biology and Biotechnology, Southern Federal University, pr. Stachki 194/1, 344090 Rostov-on-Don, Russia
- Neuroscience Center HiLife, University of Helsinki, Haartmaninkatu 8, P.O. Box 63, 00014 Helsinki, Finland
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8
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Samra N, Toubiana S, Yttervik H, Tzur-Gilat A, Morani I, Itzkovich C, Giladi L, Abu Jabal K, Cao JZ, Godley LA, Mory A, Baris Feldman H, Tveten K, Selig S, Weiss K. RBL2 bi-allelic truncating variants cause severe motor and cognitive impairment without evidence for abnormalities in DNA methylation or telomeric function. J Hum Genet 2021; 66:1101-1112. [PMID: 33980986 DOI: 10.1038/s10038-021-00931-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/14/2021] [Accepted: 04/14/2021] [Indexed: 02/01/2023]
Abstract
RBL2/p130, a member of the retinoblastoma family of proteins, is a key regulator of cell division and propagates irreversible senescence. RBL2/p130 is also involved in neuronal differentiation and survival, and eliminating Rbl2 in certain mouse strains leads to embryonic lethality accompanied by an abnormal central nervous system (CNS) phenotype. Conflicting reports exist regarding a role of RBL2/p130 in transcriptional regulation of DNA methyltransferases (DNMTs), as well as the control of telomere length. Here we describe the phenotype of three patients carrying bi-allelic RBL2-truncating variants. All presented with infantile hypotonia, severe developmental delay and microcephaly. Malignancies were not reported in carriers or patients. Previous studies carried out on mice and human cultured cells, associated RBL2 loss to DNA methylation and telomere length dysregulation. Here, we investigated whether patient cells lacking RBL2 display related abnormalities. The study of primary patient fibroblasts did not detect abnormalities in expression of DNMTs. Furthermore, methylation levels of whole genome DNA, and specifically of pericentromeric repeats and subtelomeric regions, were unperturbed. RBL2-null fibroblasts show no evidence for abnormal elongation by telomeric recombination. Finally, gradual telomere shortening, and normal onset of senescence were observed following continuous culturing of RBL2-mutated fibroblasts. Thus, this study resolves uncertainties regarding a potential non-redundant role for RBL2 in DNA methylation and telomere length regulation, and indicates that loss of function variants in RBL2 cause a severe autosomal recessive neurodevelopmental disorder in humans.
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Affiliation(s)
- Nadra Samra
- Genetic Unit, Ziv Medical Center, Tzfat, Israel.,Faculty of Medicine, Bar Ilan University, Tzfat, Israel
| | - Shir Toubiana
- Department of Genetics and Developmental Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Hilde Yttervik
- Department of Medical Genetics, University Hospital of North Norway, Tromsø, Norway
| | - Aya Tzur-Gilat
- Department of Genetics and Developmental Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | | | - Chen Itzkovich
- The Clinical Research Institute at Rambam Health Care Campus, Haifa, Israel
| | - Liran Giladi
- Department of Genetics and Developmental Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | | | - John Z Cao
- Section of Hematology Oncology, Departments of Medicine and Human Genetics, The University of Chicago, Chicago, IL, USA
| | - Lucy A Godley
- Section of Hematology Oncology, Departments of Medicine and Human Genetics, The University of Chicago, Chicago, IL, USA
| | - Adi Mory
- The Genetics Institute, Rambam Health Care Campus, Haifa, Israel.,The Genetics Institute, Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hagit Baris Feldman
- The Genetics Institute, Rambam Health Care Campus, Haifa, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.,The Genetics Institute, Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Kristian Tveten
- Department of Medical Genetics, Telemark Hospital Trust, Skien, Norway
| | - Sara Selig
- Department of Genetics and Developmental Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel. .,Laboratory of Molecular Medicine, Rambam Health Care Campus, Haifa, Israel.
| | - Karin Weiss
- The Genetics Institute, Rambam Health Care Campus, Haifa, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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9
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Brunet T, Radivojkov-Blagojevic M, Lichtner P, Kraus V, Meitinger T, Wagner M. Biallelic loss-of-function variants in RBL2 in siblings with a neurodevelopmental disorder. Ann Clin Transl Neurol 2020; 7:390-396. [PMID: 32105419 PMCID: PMC7086002 DOI: 10.1002/acn3.50992] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/17/2020] [Accepted: 01/19/2020] [Indexed: 12/15/2022] Open
Abstract
The RBL2 locus has been associated with intelligence and educational attainment but not with a monogenic disorder to date. RBL2 encodes p130, a member of the retinoblastoma protein family, which is involved in mediating neuron survival and death. Previous studies on p130 knockout mice revealing embryonic death and impaired neurogenesis underscore the importance of RBL2 in brain development. Exome sequencing in two siblings with severe intellectual disability, stereotypies and dysmorphic features identified biallelic loss-of-function variants c.556C>T, p.(Arg186Ter) and a deletion of exon 13-17 in RBL2 (NM_005611.3), establishing RBL2 as a candidate gene for an autosomal recessive neurodevelopmental disorder.
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Affiliation(s)
- Theresa Brunet
- Institute of Human Genetics, Faculty of Medicine, Technical University Munich, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Peter Lichtner
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Verena Kraus
- Department of Pediatrics, Klinik für Kinder- und Jugendmedizin, München Klinik Schwabing und Harlaching, Klinikum Rechts der Isar der Technischen Universität Munich, Munich, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Faculty of Medicine, Technical University Munich, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Matias Wagner
- Institute of Human Genetics, Faculty of Medicine, Technical University Munich, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute for Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
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10
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Xia P, Liu Y, Chen J, Cheng Z. Cell Cycle Proteins as Key Regulators of Postmitotic Cell Death. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2019; 92:641-650. [PMID: 31866779 PMCID: PMC6913832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Cell cycle progression in dividing cells, characterized by faithful replication of the genomic materials and duplication of the original cell, is fundamental for growth and reproduction of all mammalian organisms. Functional maturation of postmitotic cells, however, requires cell cycle exit and terminal differentiation. In mature postmitotic cells, many cell cycle proteins remain to be expressed, or can be induced and reactivated in pathological conditions such as traumatic injury and degenerative diseases. Interestingly, elevated levels of cell cycle proteins in postmitotic cells often do not induce proliferation, but result in aberrant cell cycle reentry and cell death. At present, the cell cycle machinery is known predominantly for regulating cell cycle progression and cell proliferation, albeit accumulating evidence indicates that cell cycle proteins may also control cell death, especially in postmitotic tissues. Herein, we provide a brief summary of these findings and hope to highlight the connection between cell cycle reentry and postmitotic cell death. In addition, we also outline the signaling pathways that have been identified in cell cycle-related cell death. Advanced understanding of the molecular mechanisms underlying cell cycle-related death is of paramount importance because this knowledge can be applied to develop protective strategies against pathologies in postmitotic tissues. Moreover, a full-scope understanding of the cell cycle machinery will allow fine tuning to favor cell proliferation over cell death, thereby potentially promoting tissue regeneration.
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Affiliation(s)
| | | | | | - Zhaokang Cheng
- To whom all correspondence should be addressed: Zhaokang Cheng, PhD, Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd. Spokane, WA 99202-2131; Tel: 509-358-7741,
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11
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D'Angelo B, Astarita C, Boffo S, Massaro-Giordano M, Antonella Ianuzzi C, Caporaso A, Macaluso M, Giordano A. LPS-induced inflammatory response triggers cell cycle reactivation in murine neuronal cells through retinoblastoma proteins induction. Cell Cycle 2019; 16:2330-2336. [PMID: 28820328 DOI: 10.1080/15384101.2017.1363943] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cell cycle reactivation in adult neurons is an early hallmark of neurodegeneration. The lipopolysaccharide (LPS) is a well-known pro-inflammatory factor that provokes neuronal cell death via glial cells activation. The retinoblastoma (RB) family includes RB1/p105, retinoblastoma-like 1 (RBL1/p107), and retinoblastoma-like 2 (Rb2/p130). Several studies have indicated that RB proteins exhibit tumor suppressor activities, and play a central role in cell cycle regulation. In this study, we assessed LPS-mediated inflammatory effect on cell cycle reactivation and apoptosis of neuronally differentiated cells. Also, we investigated whether the LPS-mediated inflammatory response can influence the function and expression of RB proteins. Our results showed that LPS challenges triggered cell cycle reactivation of differentiated neuronal cells, indicated by an accumulation of cells in S and G2/M phase. Furthermore, we found that LPS treatment also induced apoptotic death of neurons. Interestingly, we observed that LPS-mediated inflammatory effect on cell cycle re-entry and apoptosis was concomitant with the aberrant expression of RBL1/p107 and RB1/p105. To the best of our knowledge, our study is the first to indicate a role of LPS in inducing cell cycle re-entry and/or apoptosis of differentiated neuronal cells, perhaps through mechanisms altering the expression of specific members of RB family proteins. This study provides novel information on the biology of post-mitotic neurons and could help in identifying novel therapeutic targets to prevent de novo cell cycle reactivation and/or apoptosis of neurons undergoing neurodegenerative processes.
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Affiliation(s)
- Barbara D'Angelo
- a Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology , Temple University , Philadelphia , PA , USA
| | - Carlo Astarita
- a Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology , Temple University , Philadelphia , PA , USA.,b Department of Medicine, Surgery, and Neuroscience , University of Siena , Siena , Italy
| | - Silvia Boffo
- a Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology , Temple University , Philadelphia , PA , USA
| | - Mina Massaro-Giordano
- c Department of Ophthalmology, Perelman School of Medicine , University of Pennsylvania , Philadelphia , PA
| | | | - Antonella Caporaso
- d Oncology Research Center of Mercogliano (CROM) , Istituto Nazionale Tumori-IRCCS-Fondazione G. Pascale , Naples , Italy
| | - Marcella Macaluso
- a Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology , Temple University , Philadelphia , PA , USA
| | - Antonio Giordano
- a Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology , Temple University , Philadelphia , PA , USA.,b Department of Medicine, Surgery, and Neuroscience , University of Siena , Siena , Italy
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12
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Hollingsworth EW, Vaughn JE, Orack JC, Skinner C, Khouri J, Lizarraga SB, Hester ME, Watanabe F, Kosik KS, Imitola J. iPhemap: an atlas of phenotype to genotype relationships of human iPSC models of neurological diseases. EMBO Mol Med 2018; 9:1742-1762. [PMID: 29051230 PMCID: PMC5731211 DOI: 10.15252/emmm.201708191] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Disease modeling with induced pluripotent stem cells (iPSCs) is creating an abundance of phenotypic information that has become difficult to follow and interpret. Here, we report a systematic analysis of research practices and reporting bias in neurological disease models from 93 published articles. We find heterogeneity in current research practices and a reporting bias toward certain diseases. Moreover, we identified 663 CNS cell-derived phenotypes from 243 patients and 214 controls, which varied by mutation type and developmental stage in vitro We clustered these phenotypes into a taxonomy and characterized these phenotype-genotype relationships to generate a phenogenetic map that revealed novel correlations among previously unrelated genes. We also find that alterations in patient-derived molecular profiles associated with cellular phenotypes, and dysregulated genes show predominant expression in brain regions with pathology. Last, we developed the iPS cell phenogenetic map project atlas (iPhemap), an open submission, online database to continually catalog disease phenotypes. Overall, our findings offer new insights into the phenogenetics of iPSC-derived models while our web tool provides a platform for researchers to query and deposit phenotypic information of neurological diseases.
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Affiliation(s)
- Ethan W Hollingsworth
- Laboratory for Neural Stem Cells and Functional Neurogenetics, Division of Neuroimmunology and Multiple Sclerosis, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Departments of Neurology and Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Jacob E Vaughn
- Laboratory for Neural Stem Cells and Functional Neurogenetics, Division of Neuroimmunology and Multiple Sclerosis, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Departments of Neurology and Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Josh C Orack
- Laboratory for Neural Stem Cells and Functional Neurogenetics, Division of Neuroimmunology and Multiple Sclerosis, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Departments of Neurology and Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Chelsea Skinner
- Laboratory for Neural Stem Cells and Functional Neurogenetics, Division of Neuroimmunology and Multiple Sclerosis, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Departments of Neurology and Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Jamil Khouri
- Laboratory for Neural Stem Cells and Functional Neurogenetics, Division of Neuroimmunology and Multiple Sclerosis, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Departments of Neurology and Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Sofia B Lizarraga
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Mark E Hester
- Center for Perinatal Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Fumihiro Watanabe
- Laboratory for Neural Stem Cells and Functional Neurogenetics, Division of Neuroimmunology and Multiple Sclerosis, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Kenneth S Kosik
- Department of Molecular Cellular and Developmental Biology, Neuroscience Research Institute, Biomolecular Science and Engineering Program, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Jaime Imitola
- Laboratory for Neural Stem Cells and Functional Neurogenetics, Division of Neuroimmunology and Multiple Sclerosis, The Ohio State University Wexner Medical Center, Columbus, OH, USA .,Departments of Neurology and Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,The James Comprehensive Cancer Hospital, Columbus, OH, USA
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13
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Pentimalli F, Forte IM, Esposito L, Indovina P, Iannuzzi CA, Alfano L, Costa C, Barone D, Rocco G, Giordano A. RBL2/p130 is a direct AKT target and is required to induce apoptosis upon AKT inhibition in lung cancer and mesothelioma cell lines. Oncogene 2018; 37:3657-3671. [PMID: 29606701 DOI: 10.1038/s41388-018-0214-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 12/30/2017] [Accepted: 02/03/2018] [Indexed: 12/29/2022]
Abstract
The retinoblastoma (RB) protein family includes RB1/p105, RBL1/p107, and RBL2/p130, which are key factors in cell-cycle regulation and stand at the crossroads of multiple pathways dictating cell fate decisions. The role of RB proteins in apoptosis is controversial because they can inhibit or promote apoptosis depending on the context, on the apoptotic stimuli and on their intrinsic status, impacting on the response to antitumoral treatments. Here we identified RBL2/p130 as a direct substrate of the AKT kinase, a key antiapoptotic factor hyperactive in multiple cancer types. We showed that RBL2/p130 and AKT1 physically interact and AKT phosphorylates RBL2/p130 Ser941, located in the pocket domain, but not when this residue is mutated into Ala. We found that pharmacological inhibition of AKT, through the highly selective AKT inhibitor VIII (AKTiVIII), impairs RBL2/p130 Ser941 phosphorylation and increases RBL2/p130 stability, mRNA expression and nuclear levels in both lung cancer and mesothelioma cell lines, mirroring the more extensively studied effects on the p27 cell-cycle inhibitor. Consistently, AKT inhibition reduced cell viability, induced cell accumulation in G0/G1, and triggered apoptosis, which proved to be largely dependent on RBL2/p130 itself, as shown upon RBL2/p130 silencing. AKT inhibition induced RBL2/p130-dependent apoptosis also in HEK-293 cells, in which re-expression of a short hairpin-resistant RBL2/p130 was able to rescue AKTiVIII-induced apoptosis upon RBL2/p130 silencing. Our data also showed that the combination of AKT and cyclin-dependent kinases (CDK) inhibitors, which converge on the re-activation of RBL2/p130 antitumoral potential, could be a promising anticancer strategy.
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Affiliation(s)
- Francesca Pentimalli
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori - IRCCS, "Fondazione G. Pascale", 80131, Napoli, Italy.
| | - Iris M Forte
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori - IRCCS, "Fondazione G. Pascale", 80131, Napoli, Italy
| | - Luca Esposito
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori - IRCCS, "Fondazione G. Pascale", 80131, Napoli, Italy
| | - Paola Indovina
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Scienceand Technology, Temple University, Philadelphia, PA, 19122, USA
| | - Carmelina A Iannuzzi
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori - IRCCS, "Fondazione G. Pascale", 80131, Napoli, Italy.,Department of Medicine, Surgery and Neuroscience, University of Siena, 53100, Siena, Italy
| | - Luigi Alfano
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori - IRCCS, "Fondazione G. Pascale", 80131, Napoli, Italy
| | - Caterina Costa
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori - IRCCS, "Fondazione G. Pascale", 80131, Napoli, Italy
| | - Daniela Barone
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori - IRCCS, "Fondazione G. Pascale", 80131, Napoli, Italy.,Department of Medicine, Surgery and Neuroscience, University of Siena, 53100, Siena, Italy
| | - Gaetano Rocco
- Division of Thoracic Surgery, Department of Thoracic Surgery and Oncology, Istituto Nazionale Tumori "Fondazione G. Pascale"; IRCCS, 80131, Napoli, Italy
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Scienceand Technology, Temple University, Philadelphia, PA, 19122, USA. .,Department of Medicine, Surgery and Neuroscience, University of Siena, 53100, Siena, Italy.
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14
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Omais S, Jaafar C, Ghanem N. "Till Death Do Us Part": A Potential Irreversible Link Between Aberrant Cell Cycle Control and Neurodegeneration in the Adult Olfactory Bulb. Front Neurosci 2018; 12:144. [PMID: 29593485 PMCID: PMC5854681 DOI: 10.3389/fnins.2018.00144] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/22/2018] [Indexed: 12/13/2022] Open
Abstract
Adult neurogenesis (AN) is an ongoing developmental process that generates newborn neurons in the olfactory bulb (OB) and the hippocampus (Hi) throughout life and significantly contributes to brain plasticity. Adult neural stem and progenitor cells (aNSPCs) are relatively limited in number and fate and are spatially restricted to the subventricular zone (SVZ) and the subgranular zone (SGZ). During AN, the distinct roles played by cell cycle proteins extend beyond cell cycle control and constitute key regulatory mechanisms involved in neuronal maturation and survival. Importantly, aberrant cell cycle re-entry (CCE) in post-mitotic neurons has been strongly linked to the abnormal pathophysiology in rodent models of neurodegenerative diseases with potential implications on the etiology and progression of such diseases in humans. Here, we present an overview of AN in the SVZ-OB and olfactory epithelium (OE) in mice and humans followed by a comprehensive update of the distinct roles played by cell cycle proteins including major tumors suppressor genes in various steps during neurogenesis. We also discuss accumulating evidence underlining a strong link between abnormal cell cycle control, olfactory dysfunction and neurodegeneration in the adult and aging brain. We emphasize that: (1) CCE in post-mitotic neurons due to loss of cell cycle suppression and/or age-related insults as well as DNA damage can anticipate the development of neurodegenerative lesions and protein aggregates, (2) the age-related decline in SVZ and OE neurogenesis is associated with compensatory pro-survival mechanisms in the aging OB which are interestingly similar to those detected in Alzheimer's disease and Parkinson's disease in humans, and (3) the OB represents a well suitable model to study the early manifestation of age-related defects that may eventually progress into the formation of neurodegenerative lesions and, possibly, spread to the rest of the brain. Such findings may provide a novel approach to the modeling of neurodegenerative diseases in humans from early detection to progression and treatment as well.
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Affiliation(s)
- Saad Omais
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Carine Jaafar
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Noël Ghanem
- Department of Biology, American University of Beirut, Beirut, Lebanon
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15
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Alessio N, Capasso S, Ferone A, Di Bernardo G, Cipollaro M, Casale F, Peluso G, Giordano A, Galderisi U. Misidentified Human Gene Functions with Mouse Models: The Case of the Retinoblastoma Gene Family in Senescence. Neoplasia 2017; 19:781-790. [PMID: 28865301 PMCID: PMC5577395 DOI: 10.1016/j.neo.2017.06.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 06/23/2017] [Accepted: 06/27/2017] [Indexed: 12/31/2022] Open
Abstract
Although mice models rank among the most widely used tools for understanding human genetics, biology, and diseases, differences between orthologous genes among species as close as mammals are possible, particularly in orthologous gene pairs in which one or more paralogous (i.e., duplicated) genes appear in the genomes of the species. Duplicated genes can possess overlapping functions and compensate for each other. The retinoblastoma gene family demonstrates typical composite functionality in its three member genes (i.e., RB1, RB2/P130, and P107), all of which participate in controlling the cell cycle and associated phenomena, including proliferation, quiescence, apoptosis, senescence, and cell differentiation. We analyzed the role of the retinoblastoma gene family in regulating senescence in mice and humans. Silencing experiments with each member of the gene family in mesenchymal stromal cells (MSCs) and fibroblasts from mouse and human tissues demonstrated that RB1 may be indispensable for senescence in mouse cells, but not in human ones, as an example of species specificity. Furthermore, although RB2/P130 seems to be implicated in maintaining human cell senescence, the function of RB1 within any given species might differ by cell type, as an example of cell specificity. For instance, silencing RB1 in mouse fibroblasts induced a reduced senescence not observed in mouse MSCs. Our findings could be useful as a general paradigm of cautions to take when inferring the role of human genes analyzed in animal studies and when examining the role of the retinoblastoma gene family in detail.
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Affiliation(s)
- Nicola Alessio
- Department of Experimental Medicine, Biotechnology and Molecular Biology Section, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Stefania Capasso
- Department of Experimental Medicine, Biotechnology and Molecular Biology Section, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Angela Ferone
- Department of Experimental Medicine, Biotechnology and Molecular Biology Section, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Giovanni Di Bernardo
- Department of Experimental Medicine, Biotechnology and Molecular Biology Section, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Marilena Cipollaro
- Department of Experimental Medicine, Biotechnology and Molecular Biology Section, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Fiorina Casale
- Dipartimento della Donna, del Bambino e di Chirurgia Generale e Specialistica, University of Campania "Luigi Vanvitelli", Naples, Italy
| | | | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine and Department of Biology, College of Science and Technology, Temple University, Philadelphia PA; Department of Medicine, Surgery & Neuroscience, University of Siena, Siena, Italy
| | - Umberto Galderisi
- Sbarro Institute for Cancer Research and Molecular Medicine and Department of Biology, College of Science and Technology, Temple University, Philadelphia PA; Department of Experimental Medicine, Biotechnology and Molecular Biology Section, University of Campania "Luigi Vanvitelli", Naples, Italy; Institute of Bioscience and Bioresources, CNR, Naples, Italy.
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16
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Koleck TA, Bender CM, Clark BZ, Ryan CM, Ghotkar P, Brufsky A, McAuliffe PF, Rastogi P, Sereika SM, Conley YP. An exploratory study of host polymorphisms in genes that clinically characterize breast cancer tumors and pretreatment cognitive performance in breast cancer survivors. BREAST CANCER (DOVE MEDICAL PRESS) 2017; 9:95-110. [PMID: 28424560 PMCID: PMC5344452 DOI: 10.2147/bctt.s123785] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE Inspired by the hypothesis that heterogeneity in the biology of breast cancers at the cellular level may account for cognitive dysfunction symptom variability in survivors, the current study explored relationships between host single-nucleotide polymorphisms (SNPs) in 25 breast cancer-related candidate genes (AURKA, BAG1, BCL2, BIRC5, CCNB1, CD68, CENPA, CMC2, CTSL2, DIAPH3, ERBB2, ESR1, GRB7, GSTM1, MELK, MKI67, MMP11, MYBL2, NDC80, ORC6, PGR, RACGAP1, RFC4, RRM2, and SCUBE2), identified from clinically relevant prognostic multigene-expression profiles for breast cancer, and pretreatment cognitive performance. PATIENTS AND METHODS The sample (n=220) was comprised of 138 postmenopausal women newly diagnosed with early stage breast cancer and 82 postmenopausal age- and education-matched healthy controls without breast cancer. Cognitive performance was assessed after primary surgery but prior to initiation of adjuvant chemotherapy and/or hormonal therapy using a comprehensive battery of neuropsychological tests encompassing eight cognitive function composite domains: attention, concentration, executive function, mental flexibility, psychomotor speed, verbal memory, visual memory, and visual working memory. In total, 131 SNPs were included in the analysis. Standard and robust multiple linear regression modeling was used to examine relationships between each domain and the presence or absence of one or more minor alleles for each SNP. Genetic risk/protection scores (GRSs) were calculated for each domain to evaluate the collective effect of possession of multiple risk/protective alleles. RESULTS With the exception of CMC2, MMP11, and RACGAP1, significant (P<0.05) SNP main effect and/or SNP by future prescribed treatment group interactions were observed for every gene between at least one domain and one or more SNPs. All GRSs were found to be significantly (P<0.001) associated with each respective domain score. CONCLUSION Associations between host SNPs and computed GRSs and variability in pretreatment cognitive function performance support the study hypothesis, and warrant further investigations to identify biomarkers for breast cancer-related cognitive dysfunction.
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Affiliation(s)
- Theresa A Koleck
- School of Nursing, University of Pittsburgh, Pittsburgh, PA
- School of Nursing, Columbia University, New York, NY
| | | | - Beth Z Clark
- Division of Gynecologic Pathology, Magee-Womens Hospital of University of Pittsburgh Medical Center (UPMC)
- School of Medicine
| | - Christopher M Ryan
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA
- Department of Psychiatry, University of California San Francisco, San Francisco, CA
| | - Puja Ghotkar
- School of Nursing, University of Pittsburgh, Pittsburgh, PA
| | - Adam Brufsky
- School of Medicine
- Division of Hematology/Oncology, Magee-Womens Hospital of UPMC
- University of Pittsburgh Cancer Institute
| | - Priscilla F McAuliffe
- School of Medicine
- University of Pittsburgh Cancer Institute
- Division of Breast Surgical Oncology, Magee-Womens Hospital of UPMC
| | - Priya Rastogi
- School of Medicine
- Division of Hematology/Oncology, Magee-Womens Hospital of UPMC
| | - Susan M Sereika
- School of Nursing, University of Pittsburgh, Pittsburgh, PA
- Department of Biostatistics
- Department of Epidemiology
| | - Yvette P Conley
- School of Nursing, University of Pittsburgh, Pittsburgh, PA
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
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17
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Fong BC, Slack RS. RB: An essential player in adult neurogenesis. NEUROGENESIS 2017; 4:e1270382. [PMID: 28229086 DOI: 10.1080/23262133.2016.1270382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/30/2016] [Accepted: 12/04/2016] [Indexed: 12/16/2022]
Abstract
The fundamental mechanisms underlying adult neurogenesis remain to be fully clarified. Members of the cell cycle machinery have demonstrated key roles in regulating adult neural stem cell (NSC) quiescence and the size of the adult-born neuronal population. The retinoblastoma protein, Rb, is known to possess CNS-specific requirements that are independent from its classical role as a tumor suppressor. The recent study by Vandenbosch et al. has clarified distinct requirements for Rb during adult neurogenesis, in the restriction of proliferation, as well as long-term adult-born neuronal survival. However, Rb is no longer believed to be the main cell cycle regulator maintaining the quiescence of adult NSCs. Future studies must consider Rb as part of a larger network of regulatory effectors, including the other members of the Rb family, p107 and p130. This will help elucidate the contribution of Rb and other pocket proteins in the context of adult neurogenesis, and define its crucial role in regulating the size and fate of the neurogenic niche.
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Affiliation(s)
- Bensun C Fong
- University of Ottawa Brain and Mind Research Institute, Department of Cellular & Molecular Medicine, University of Ottawa , Ottawa, ON, Canada
| | - Ruth S Slack
- University of Ottawa Brain and Mind Research Institute, Department of Cellular & Molecular Medicine, University of Ottawa , Ottawa, ON, Canada
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18
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Role and regulation of Cdc25A phosphatase in neuron death induced by NGF deprivation or β-amyloid. Cell Death Discov 2016; 2:16083. [PMID: 28028440 PMCID: PMC5149581 DOI: 10.1038/cddiscovery.2016.83] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 09/23/2016] [Indexed: 12/23/2022] Open
Abstract
Neuron death during development and in Alzheimer’s disease (AD) is associated with aberrant regulation/induction of cell cycle proteins. However, the proximal events in this process are unknown. Cell cycle initiation requires dephosphorylation of cyclin-dependent kinases by cell division cycle 25A (Cdc25A). Here, we show that Cdc25A is essential for neuronal death in response to NGF deprivation or β-amyloid (Aβ) treatment and describe the mechanisms by which it is regulated in these paradigms. Cdc25A mRNA, protein and Cdc25A phosphatase activity were induced by NGF deprivation and Aβ treatment. Enhanced Cdc25A expression was also observed in rat brains infused with Aβ and in Aβ-overexpressing AβPPswe-PS1dE9 mice. In cultured neurons Cdc25A inhibition by chemical inhibitors or shRNA prevented cell death and neurite degeneration caused by NGF deprivation or Aβ. Additionally, Cdc25A inhibition diminished distal signaling events including Cdk-dependent elevation of phospho-pRb and subsequent caspase-3 activation. Mechanism studies revealed that Cdc25A induction by NGF deprivation and Aβ is mediated by activation of Forkhead transcription factors that in turn suppress miR-21, a negative regulator of Cdc25A. Our studies thus identify Cdc25A as a required upstream element of the apoptotic cell cycle pathway that is required for neuron death in response to trophic factor deprivation and to Aβ exposure and therefore as a potential target to suppress pathologic neuron death.
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19
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Fujiwara K, Hasegawa K, Oka M, Yoneda Y, Yoshikawa K. Terminal differentiation of cortical neurons rapidly remodels RanGAP-mediated nuclear transport system. Genes Cells 2016; 21:1176-1194. [DOI: 10.1111/gtc.12434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 08/16/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Kazushiro Fujiwara
- Institute for Protein Research; Osaka University; Suita Osaka 565-0871 Japan
| | - Koichi Hasegawa
- Institute for Protein Research; Osaka University; Suita Osaka 565-0871 Japan
| | - Masahiro Oka
- National Institutes of Biomedical Innovation, Health and Nutrition; Ibaraki Osaka 567-0085 Japan
| | - Yoshihiro Yoneda
- National Institutes of Biomedical Innovation, Health and Nutrition; Ibaraki Osaka 567-0085 Japan
| | - Kazuaki Yoshikawa
- Institute for Protein Research; Osaka University; Suita Osaka 565-0871 Japan
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20
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Histone deacetylase inhibition is cytotoxic to oligodendrocyte precursor cells in vitro and in vivo. Int J Dev Neurosci 2016; 54:53-61. [PMID: 27587342 DOI: 10.1016/j.ijdevneu.2016.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 08/26/2016] [Accepted: 08/27/2016] [Indexed: 11/24/2022] Open
Abstract
Histone deacetylase (HDAC) inhibition mediated by small molecule HDAC inhibitors (HDACi) has demonstrated divergent effects including toxicity towards transformed cell lines, neuroprotection in neurological disease models, and inhibition of oligodendrocyte precursor cell (OPC) differentiation to mature oligodendrocytes (OL). However, it remains unknown if transient HDAC inhibition may promote OPC survival. Using mouse cortical OPC primary cultures, we investigated the effects of the FDA approved pan-HDACi suberoylanilide hydroxamic acid (SAHA) on OPC survival. Initial studies showed differences in the HDAC expression pattern of multiple HDAC isoforms in OPCs relative to their terminally differentiated progeny cells, OLs and astrocytes. Treatment of OPCs with SAHA for up to 72h using a maximum concentration either at or lower than those necessary for cytotoxicity in most transformed cell lines resulted in over 67% reduction in viability relative to vehicle-treated OPCs. This was at least partly due to increased apoptosis as SAHA-treated cells displayed activated caspase 3 and were protected by the general caspase inhibitor Q-VD-OPH. Additionally, SAHA treatment of whole mice at postnatal day 5 induced apoptosis of cortical OPCs. These results suggest that SAHA negatively impacts OPC survival and may be detrimental to the myelinating brain and spinal cord. Such toxicity may be relevant in a clinical context as SAHA is currently involved in numerous clinical trials and is in consideration for use in the treatment of psychiatric and neurodegenerative conditions.
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21
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Indovina P, Pentimalli F, Casini N, Vocca I, Giordano A. RB1 dual role in proliferation and apoptosis: cell fate control and implications for cancer therapy. Oncotarget 2016; 6:17873-90. [PMID: 26160835 PMCID: PMC4627222 DOI: 10.18632/oncotarget.4286] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 06/06/2015] [Indexed: 01/14/2023] Open
Abstract
Inactivation of the retinoblastoma (RB1) tumor suppressor is one of the most frequent and early recognized molecular hallmarks of cancer. RB1, although mainly studied for its role in the regulation of cell cycle, emerged as a key regulator of many biological processes. Among these, RB1 has been implicated in the regulation of apoptosis, the alteration of which underlies both cancer development and resistance to therapy. RB1 role in apoptosis, however, is still controversial because, depending on the context, the apoptotic cues, and its own status, RB1 can act either by inhibiting or promoting apoptosis. Moreover, the mechanisms whereby RB1 controls both proliferation and apoptosis in a coordinated manner are only now beginning to be unraveled. Here, by reviewing the main studies assessing the effect of RB1 status and modulation on these processes, we provide an overview of the possible underlying molecular mechanisms whereby RB1, and its family members, dictate cell fate in various contexts. We also describe the current antitumoral strategies aimed at the use of RB1 as predictive, prognostic and therapeutic target in cancer. A thorough understanding of RB1 function in controlling cell fate determination is crucial for a successful translation of RB1 status assessment in the clinical setting.
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Affiliation(s)
- Paola Indovina
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA.,Department of Medicine, Surgery and Neuroscience, University of Siena and Istituto Toscano Tumori (ITT), Siena, Italy
| | - Francesca Pentimalli
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori "Fodazione G. Pascale" - IRCCS, Naples, Italy
| | - Nadia Casini
- Department of Medicine, Surgery and Neuroscience, University of Siena and Istituto Toscano Tumori (ITT), Siena, Italy
| | - Immacolata Vocca
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori "Fodazione G. Pascale" - IRCCS, Naples, Italy
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA.,Department of Medicine, Surgery and Neuroscience, University of Siena and Istituto Toscano Tumori (ITT), Siena, Italy
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22
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Aguilar R, Bustos FJ, Saez M, Rojas A, Allende ML, van Wijnen AJ, van Zundert B, Montecino M. Polycomb PRC2 complex mediates epigenetic silencing of a critical osteogenic master regulator in the hippocampus. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:1043-55. [PMID: 27216774 DOI: 10.1016/j.bbagrm.2016.05.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 05/18/2016] [Accepted: 05/19/2016] [Indexed: 12/12/2022]
Abstract
During hippocampal neuron differentiation, the expression of critical inducers of non-neuronal cell lineages must be efficiently silenced. Runx2 transcription factor is the master regulator of mesenchymal cells responsible for intramembranous osteoblast differentiation and formation of the craniofacial bone tissue that surrounds and protects the central nervous system (CNS) in mammalian embryos. The molecular mechanisms that mediate silencing of the Runx2 gene and its downstream target osteogenic-related genes in neuronal cells have not been explored. Here, we assess the epigenetic mechanisms that mediate silencing of osteoblast-specific genes in CNS neurons. In particular, we address the contribution of histone epigenetic marks and histone modifiers on the silencing of the Runx2/p57 bone-related isoform in rat hippocampal tissues at embryonic to adult stages. Our results indicate enrichment of repressive chromatin histone marks and of the Polycomb PRC2 complex at the Runx2/p57 promoter region. Knockdown of PRC2 H3K27-methyltransferases Ezh2 and Ezh1, or forced expression of the Trithorax/COMPASS subunit Wdr5 activates Runx2/p57 mRNA expression in both immature and mature hippocampal cells. Together these results indicate that complementary epigenetic mechanisms progressively and efficiently silence critical osteoblastic genes during hippocampal neuron differentiation.
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Affiliation(s)
- Rodrigo Aguilar
- Center for Biomedical Research, Universidad Andres Bello, Santiago 8370146, Chile; FONDAP Center for Genome Regulation, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago 8370146, Chile
| | - Fernando J Bustos
- Center for Biomedical Research, Universidad Andres Bello, Santiago 8370146, Chile; FONDAP Center for Genome Regulation, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago 8370146, Chile
| | - Mauricio Saez
- Center for Biomedical Research, Universidad Andres Bello, Santiago 8370146, Chile; FONDAP Center for Genome Regulation, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago 8370146, Chile
| | - Adriana Rojas
- Center for Biomedical Research, Universidad Andres Bello, Santiago 8370146, Chile; FONDAP Center for Genome Regulation, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago 8370146, Chile
| | - Miguel L Allende
- FONDAP Center for Genome Regulation, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago 8370146, Chile; Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago 7800003, Chile
| | | | - Brigitte van Zundert
- Center for Biomedical Research, Universidad Andres Bello, Santiago 8370146, Chile
| | - Martin Montecino
- Center for Biomedical Research, Universidad Andres Bello, Santiago 8370146, Chile; FONDAP Center for Genome Regulation, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago 8370146, Chile.
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23
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Tokarz P, Kaarniranta K, Blasiak J. Role of the Cell Cycle Re-Initiation in DNA Damage Response of Post-Mitotic Cells and Its Implication in the Pathogenesis of Neurodegenerative Diseases. Rejuvenation Res 2016. [DOI: 10.1089/rej.2015.1717] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Paulina Tokarz
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska, Lodz, Poland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland
| | - Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska, Lodz, Poland
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24
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Abstract
Neurons are usually regarded as postmitotic cells that undergo apoptosis in response to cell cycle reactivation. Nevertheless, recent evidence indicates the existence of a defined developmental program that induces DNA replication in specific populations of neurons, which remain in a tetraploid state for the rest of their adult life. Similarly, de novo neuronal tetraploidization has also been described in the adult brain as an early hallmark of neurodegeneration. The aim of this review is to integrate these recent developments in the context of cell cycle regulation and apoptotic cell death in neurons. We conclude that a variety of mechanisms exists in neuronal cells for G1/S and G2/M checkpoint regulation. These mechanisms, which are connected with the apoptotic machinery, can be modulated by environmental signals and the neuronal phenotype itself, thus resulting in a variety of outcomes ranging from cell death at the G1/S checkpoint to full proliferation of differentiated neurons.
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Key Words
- AD, Alzheimer disease
- BDNF, brain-derived neurotrophic factor
- BrdU, 5-bromo-2′-deoxyuridine
- CKI, Cdk-inhibitor
- CNS, central nervous system
- Cdk, cyclin-dependent kinase
- Cip/Kip, cyclin inhibitor protein/kinase inhibitor protein
- G0, quiescent state
- G1, growth phase 1
- G2, growth phase 2
- Ink, inhibitor of kinase
- Mcm2, minichromosome maintenance 2
- PCNA, proliferating cell nuclear antigen
- PD, Parkinson disease
- RGCs, retinal ganglion cells
- Rb, Retinoblastoma
- S-phase
- S-phase, synthesis phase.
- apoptosis
- cell cycle re-entry
- mitosis
- neuron
- p38MAPK, p38 mitogen-activated protein kinase
- p75NTR, neurotrophin receptor p75
- tetraploid
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Affiliation(s)
- José M Frade
- a Department of Molecular, Cellular and Developmental Neurobiology; Instituto Cajal; Consejo Superior de Investigaciones Científicas (IC-CSIC) ; Madrid , Spain
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25
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Sherwani SI, Khan HA. Role of 5-hydroxymethylcytosine in neurodegeneration. Gene 2015; 570:17-24. [PMID: 26115768 DOI: 10.1016/j.gene.2015.06.052] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 05/18/2015] [Accepted: 06/18/2015] [Indexed: 02/05/2023]
Abstract
The recent discovery of 5-hydroxymethylcytosine (5hmC), an epigenetic modifier and oxidation product of 5-methylcytosine (5mC), has broadened the scope and understanding of neural development and neurodegenerative diseases. By virtue of their functional groups, 5mC and 5hmC exert opposite effects on gene expression; the former is generally associated with gene silencing whereas the latter is mainly involved in up-regulation of gene expression affecting the cellular processes such as differentiation, development, and aging. Although DNA methylation plays an important role in normal neural development and neuroprotection, an altered pathway due to complex interaction with environmental and genetic factors may cause severe neurodegeneration. The levels of 5hmC in brain increase progressively from birth until death, while in patients with neurodegenerative disorders, the levels are found to be highly compromised. This article discusses the recent developments in the area of hydroxymethylation, with particular emphasis on the role of 5hmC in neurodegenerative diseases including Alzheimer's disease, Parkinson's diseases and Huntington's disease. We have also included recent findings on the role of 5hmC in brain tumors (gliomas). Despite compelling evidence on the involvement of 5hmC in neurodegeneration, it is yet to be established whether this epigenetic molecule is the cause or the effect of the onset and progression of neurodegenerative diseases.
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Affiliation(s)
- Shariq I Sherwani
- Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University College of Medicine, Columbus, OH 43210, USA
| | - Haseeb A Khan
- Department of Biochemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
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26
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Vashishta A, Hetman M. Inhibitors of histone deacetylases enhance neurotoxicity of DNA damage. Neuromolecular Med 2014; 16:727-41. [PMID: 25063076 DOI: 10.1007/s12017-014-8322-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 07/18/2014] [Indexed: 12/11/2022]
Abstract
The nonselective inhibitors of class I/II histone deacetylases (HDACs) including trichostatin A and the clinically used suberoylanilide hydroxamic acid (SAHA, vorinostat) are neuroprotective in several models of neuronal injury. Here, we report that in cultured cortical neurons from newborn rats and in the cerebral cortex of whole neonate rats, these HDAC inhibitors exacerbated cytotoxicity of the DNA double-strand break (DSB)-inducing anticancer drug etoposide by enhancing apoptosis. Similar neurotoxic interactions were also observed in neurons that were treated with other DNA damaging drugs including cisplatin and camptothecin. In addition, in rat neonates, SAHA increased cortical neuron apoptosis that was induced by a single injection of the NMDA receptor antagonist dizocilpine (MK801). In etoposide-treated neurons, the nonselective HDAC inhibition resulted in more DSBs. It also potentiated etoposide-induced accumulation and phosphorylation of the pro-apoptotic transcription factor p53. Moreover, nonselective HDAC inhibition exacerbated neuronal apoptosis that was induced by the overexpressed p53. Importantly, such effects cannot be fully explained by inhibition of HDAC1, which is known to play a role in DSB repair and regulation of p53. The specific HDAC1 inhibitor MS275 only moderately enhanced etoposide-induced neuronal death. Although in etoposide-treated neurons MS275 increased DSBs, it did not affect activation of p53. Our findings suggest that besides HDAC1, there are other class I/II HDACs that participate in neuronal DNA damage response attenuating neurotoxic consequences of genotoxic insults to the developing brain.
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Affiliation(s)
- A Vashishta
- Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, University of Louisville, 511 S. Floyd St., MDR616, Louisville, KY, 40292, USA
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27
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Iyirhiaro GO, Zhang Y, Estey C, O'Hare MJ, Safarpour F, Parsanejad M, Wang S, Abdel-Messih E, Callaghan SM, During MJ, Slack RS, Park DS. Regulation of ischemic neuronal death by E2F4-p130 protein complexes. J Biol Chem 2014; 289:18202-13. [PMID: 24828495 DOI: 10.1074/jbc.m114.574145] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inappropriate activation of cell cycle proteins, in particular cyclin D/Cdk4, is implicated in neuronal death induced by various pathologic stresses, including DNA damage and ischemia. Key targets of Cdk4 in proliferating cells include members of the E2F transcription factors, which mediate the expression of cell cycle proteins as well as death-inducing genes. However, the presence of multiple E2F family members complicates our understanding of their role in death. We focused on whether E2F4, an E2F member believed to exhibit crucial control over the maintenance of a differentiated state of neurons, may be critical in ischemic neuronal death. We observed that, in contrast to E2F1 and E2F3, which sensitize to death, E2F4 plays a crucial protective role in neuronal death evoked by DNA damage, hypoxia, and global ischemic insult both in vitro and in vivo. E2F4 occupies promoter regions of proapoptotic factors, such as B-Myb, under basal conditions. Following stress exposure, E2F4-p130 complexes are lost rapidly along with the presence of E2F4 at E2F-containing B-Myb promoter sites. In contrast, the presence of E2F1 at B-Myb sites increases with stress. Furthermore, B-Myb and C-Myb expression increases with ischemic insult. Taken together, we propose a model by which E2F4 plays a protective role in neurons from ischemic insult by forming repressive complexes that prevent prodeath factors such as Myb from being expressed.
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Affiliation(s)
- Grace O Iyirhiaro
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - Yi Zhang
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - Carmen Estey
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - Michael J O'Hare
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - Farzaneh Safarpour
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - Mohammad Parsanejad
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - Suzi Wang
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - Elizabeth Abdel-Messih
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - Steve M Callaghan
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - Matthew J During
- the Department of Molecular Virology, Immunology, and Medical Genetics, Neurological Surgery, College of Medicine, The Ohio State University, Columbus, Ohio 43210
| | - Ruth S Slack
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
| | - David S Park
- From the Department of Cellular and Molecular Medicine and Neuroscience, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada and
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28
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Recillas-Targa F. Interdependency between genetic and epigenetic regulatory defects in cancer. Methods Mol Biol 2014; 1165:33-52. [PMID: 24839017 DOI: 10.1007/978-1-4939-0856-1_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Epigenetic regulation is understood as heritable changes in gene expression and genome function that can occur without affecting the DNA sequence. In its in vivo context DNA is coupled to a group of small basic proteins that together with the DNA form the chromatin. The organization and regulation of the chromatin alliance with multiple nuclear functions are inconceivable without genetic information. With the advance on the understanding of the chromatin organization of the eukaryotic genome, it has been clear that not only genetics but also epigenetics influence both normal human biology and diseases. As a consequence, the basic concepts and mechanisms of cancer need to be readdressed and viewed not only locally but also at the whole genome scale or even, in the three-dimensional context of the cell nucleus space. Such a vision has a larger impact than has been previously predicted, since phenomena like aging, senescence, the entail of nutrition, stem cell biology, and cancer are orchestrated by epigenetic and genetic processes. Here I describe the relevance and central role of genetic and epigenetic defects in cancer.
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Affiliation(s)
- Félix Recillas-Targa
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, 04510, D.F, México,
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29
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Ovejero-Benito MC, Frade JM. Brain-derived neurotrophic factor-dependent cdk1 inhibition prevents G2/M progression in differentiating tetraploid neurons. PLoS One 2013; 8:e64890. [PMID: 23741412 PMCID: PMC3669015 DOI: 10.1371/journal.pone.0064890] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/19/2013] [Indexed: 11/28/2022] Open
Abstract
Neurodegeneration is often associated with DNA synthesis in neurons, the latter usually remaining for a long time as tetraploid cells before dying by apoptosis. The molecular mechanism preventing G2/M transition in these neurons remains unknown, but it may be reminiscent of the mechanism that maintains tetraploid retinal ganglion cells (RGCs) in a G2-like state during normal development, thus preventing their death. Here we show that this latter process, known to depend on brain-derived neurotrophic factor (BDNF), requires the inhibition of cdk1 by TrkB. We demonstrate that a subpopulation of chick RGCs previously shown to become tetraploid co-expresses TrkB and cdk1 in vivo. By using an in vitro system that recapitulates differentiation and cell cycle re-entry of chick retinal neurons we show that BDNF, employed at concentrations specific for the TrkB receptor, reduces the expression of cdk1 in TrkB-positive, differentiating neurons. In this system, BDNF also inhibits the activity of both endogenous cdk1 and exogenously-expressed cdk1/cyclin B1 complex. This inhibition correlates with the phosphorylation of cdk1 at Tyr15, an effect that can be prevented with K252a, a tyrosine kinase inhibitor commonly used to prevent the activity of neurotrophins through their Trk receptors. The effect of BDNF on cdk1 activity is Tyr15-specific since BDNF cannot prevent the activity of a constitutively active form of cdk1 (Tyr15Phe) when expressed in differentiating retinal neurons. We also show that BDNF-dependent phosphorylation of cdk1 at Tyr15 could not be blocked with MK-1775, a Wee1-selective inhibitor, indicating that Tyr15 phosphorylation in cdk1 does not seem to occur through the canonical mechanism observed in proliferating cells. We conclude that the inhibition of both expression and activity of cdk1 through a BDNF-dependent mechanism contributes to the maintenance of tetraploid RGCs in a G2-like state.
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Affiliation(s)
- María C. Ovejero-Benito
- Department of Molecular, Cellular, and Developmental Neurobiology, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - José M. Frade
- Department of Molecular, Cellular, and Developmental Neurobiology, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain
- * E-mail:
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30
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Fiorentino FP, Marchesi I, Giordano A. On the role of retinoblastoma family proteins in the establishment and maintenance of the epigenetic landscape. J Cell Physiol 2013; 228:276-84. [PMID: 22718354 DOI: 10.1002/jcp.24141] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
RB family members are negative regulators of the cell cycle, involved in numerous biological processes such as cellular senescence, development and differentiation. Disruption of RB family pathways are linked to loss of cell cycle control, cellular immortalization and cancer. RB family, and in particular the most studied member RB/p105, has been considered a tumor suppressor gene by more than three decades, and numerous efforts have been done to understand his molecular activity. However, the epigenetic mechanisms behind Rb-mediated tumor suppression have been uncovered only in recent years. In this review, the role of RB family members in cancer epigenetics will be discussed. We start with an introduction to epigenomes, chromatin modifications and cancer epigenetics. In order to provide a clear picture of the involvement of RB family in the epigenetic field, we describe the RB family role in the epigenetic landscape dynamics based on the heterochromatin variety involved, facultative or constitutive. We want to stress that, despite dissimilar modulations, RB family is involved in both mammalian varieties of heterochromatin establishment and maintenance and that disruption of RB family pathways drives to alterations of both heterochromatin structures, thus to the global epigenetic landscape.
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Affiliation(s)
- Francesco Paolo Fiorentino
- Department of Biology, Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania 19122, USA.
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31
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Abstract
The retinoblastoma protein (Rb) family members are essential regulators of cell cycle progression, principally through regulation of the E2f transcription factors. Growing evidence indicates that abnormal cell cycle signals can participate in neuronal death. In this regard, the role of Rb (p105) itself has been controversial. Germline Rb deletion leads to massive neuronal loss, but initial reports argue that death is non-cell autonomous. To more definitively resolve this question, we generated acute murine knock-out models of Rb in terminally differentiated neurons in vitro and in vivo. Surprisingly, we report that acute inactivation of Rb in postmitotic neurons results in ectopic cell cycle protein expression and neuronal loss without concurrent induction of classical E2f-mediated apoptotic genes, such as Apaf1 or Puma. These results suggest that terminally differentiated neurons require Rb for continuous cell cycle repression and survival.
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32
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Histone methylation in the nervous system: functions and dysfunctions. Mol Neurobiol 2012; 47:740-56. [PMID: 23161382 DOI: 10.1007/s12035-012-8376-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 11/04/2012] [Indexed: 11/26/2022]
Abstract
Chromatin remodeling is a key epigenetic process controlling the regulation of gene transcription. Local changes of chromatin architecture can be achieved by post-translational modifications of histones such as methylation, acetylation, phosphorylation, ubiquitination, sumoylation, and ADP-ribosylation. These changes are dynamic and allow for rapid repression or de-repression of specific target genes. Chromatin remodeling enzymes are largely involved in the control of cellular differentiation, and loss or gain of function is often correlated with pathological events. For these reasons, research on chromatin remodeling enzymes is currently very active and rapidly expanding, these enzymes representing very promising targets for the design of novel therapeutics in different areas of medicine including oncology and neurology. In this review, we focus on histone methylation in the nervous system. We provide an overview on mammalian histone methyltransferases and demethylases and their mechanisms of action, and we discuss their roles in the development of the nervous system and their involvement in neurodevelopmental, neurodegenerative, and behavioral disorders.
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33
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Nerve growth factor-induced cell cycle reentry in newborn neurons is triggered by p38MAPK-dependent E2F4 phosphorylation. Mol Cell Biol 2012; 32:2722-37. [PMID: 22586272 DOI: 10.1128/mcb.00239-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cumulative evidence indicates that activation of cyclin D-dependent kinase 4/6 (cdk4/6) represents a major trigger of cell cycle reentry and apoptosis in vertebrate neurons. We show here the existence of another mechanism triggering cell cycle reentry in differentiating chick retinal neurons (DCRNs), based on phosphorylation of E2F4 by p38(MAPK). We demonstrate that the activation of p75(NTR) by nerve growth factor (NGF) induces nuclear p38(MAPK) kinase activity, which leads to Thr phosphorylation and subsequent recruitment of E2F4 to the E2F-responsive cdc2 promoter. Inhibition of p38(MAPK), but not of cdk4/6, specifically prevents NGF-dependent cell cycle reentry and apoptosis in DCRNs. Moreover, a constitutively active form of chick E2F4 (Thr261Glu/Thr263Glu) stimulates G(1)/S transition and apoptosis, even after inhibition of p38(MAPK) activity. In contrast, a dominant-negative E2F4 form (Thr261Ala/Thr263Ala) prevents NGF-induced cell cycle reactivation and cell death in DCRNs. These results indicate that NGF-induced cell cycle reentry in neurons depends on the activation of a novel, cdk4/6-independent pathway that may participate in neurodegeneration.
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34
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Lagali PS, Picketts DJ. Matters of life and death: the role of chromatin remodeling proteins in retinal neuron survival. J Ocul Biol Dis Infor 2012; 4:111-20. [PMID: 23289056 PMCID: PMC3382293 DOI: 10.1007/s12177-012-9080-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 03/05/2012] [Indexed: 12/13/2022] Open
Abstract
Retinal neurons are highly vulnerable to a diverse array of neurotoxic stimuli that leads to their degeneration, which is a major contributor to blindness. This review summarizes the role of epigenetic factors in mediating neuronal homeostasis and survival to protect against cell death and neurodegenerative conditions. Studies in human patients and mouse models implicate numerous chromatin modifications in neuroprotective processes including histone protein acetylation and methylation, DNA methylation, and ATP-dependent nucleosome remodeling. Recent research has begun to uncover specific epigenetic mechanisms invoked by neurotoxic stimuli. Continued investigation in this area will be the key to the generation of therapeutic strategies for the intervention of retinal neurodegenerative diseases.
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Affiliation(s)
- Pamela S Lagali
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON Canada K1H 8L6 ; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON Canada K1H 8M5
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35
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Chuang JY, Chang WC, Hung JJ. Hydrogen peroxide induces Sp1 methylation and thereby suppresses cyclin B1 via recruitment of Suv39H1 and HDAC1 in cancer cells. Free Radic Biol Med 2011; 51:2309-18. [PMID: 22036763 DOI: 10.1016/j.freeradbiomed.2011.10.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 09/29/2011] [Accepted: 10/01/2011] [Indexed: 12/31/2022]
Abstract
Sp1 is an important transcription factor for a number of genes that regulate cell growth and survival. Sp1 is an anchor protein that recruits other factors to regulate its target genes positively or negatively, but the mechanism of its functional switch by which positive or negative coregulators are recruited is not clear. In this study, we found that Sp1 could be methylated and that methylation was maintained by treatment with pargyline, a lysine-specific demethylase 1 (LSD1) inhibitor or knock LSD1 down directly. Hydrogen peroxide treatment increased the methylation of Sp1 and repressed Sp1 transcriptional activity. Investigation of the mechanism by which methylation decreased Sp1 activity found that methylation of Sp1 increased the recruitment of Su(var) 3-9 homologue 1(Suv39H1) and histone deacetylase 1 (HDAC1) to the cyclin B1 promoter, resulting in deacetylation and methylation of histone H3 and subsequent downregulation of cyclin B1. Finally, downregulation of cyclin B1 led to cell cycle arrest at the G2 phase. These results show that methylation of Sp1 causes it to act as a negative regulator by recruiting Suv39H1 and HDAC1 to induce chromatin remodeling. This finding that methylation acts as a functional switch provides new insight into the modulation of Sp1 transcriptional activity.
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Affiliation(s)
- Jian-Ying Chuang
- Department of Pharmacology, National Cheng Kung University, Tainan 701, Taiwan
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36
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p300-Dependent ATF5 acetylation is essential for Egr-1 gene activation and cell proliferation and survival. Mol Cell Biol 2011; 31:3906-16. [PMID: 21791614 DOI: 10.1128/mcb.05887-11] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
ATF5 has been shown to be a critical regulator of cell proliferation and survival; however, the underlying mechanism remains largely unknown. We demonstrate here that ATF5 interacts with the transcriptional coactivator p300, which acetylates ATF5 at lysine-29 (K29), which in turn enhances the interaction between ATF5 and p300 and binding of the ATF5/p300 complex to the ATF5 response element (ARE) region of the Egr-1 promoter. ARE-bound ATF5/p300 acetylates lysine-14 (K14) of nucleosomal histone H3 at both the ARE and serum response element (SRE) of the Egr-1 promoter, which facilitates binding of extracellular signal-regulated kinase (ERK)-phosphorylated Elk-1 to the SRE, activating the Egr-1 promoter. Interference of p300-dependent acetylation of ATF5 or nucleosomal histone H3 or blockade of ERK-dependent Elk-1 phosphorylation abrogates ATF5-dependent Egr-1 activation and cell proliferation and survival. These findings assign a central role for the ATF5/p300 complex in ATF5 function and suggest that coordinated actions by ATF5, p300, Elk-1, and ERK/mitogen-activated protein kinase (MAPK) are essential for ATF5-dependent Egr-1 activation and cell proliferation and survival.
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37
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TNF-α response of vascular endothelial and vascular smooth muscle cells involve differential utilization of ASK1 kinase and p73. Cell Death Differ 2011; 19:274-83. [PMID: 21738216 DOI: 10.1038/cdd.2011.93] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Atherosclerosis involves a specialized inflammatory process regulated by an intricate network of cytokine and chemokine signaling. Atherosclerotic lesions lead to the release of cytokines that can have multiple affects on various vascular cell functions either promoting lesion expansion or alternatively retard progression. Tumor necrosis factor-α (TNF-α) is one such cytokine that can activate both cell survival and cell death mechanisms simultaneously. Here we show that TNF-α induces apoptosis in human aortic endothelial cells (HAECs), while it promotes the proliferation of vascular smooth muscle cells (VSMCs). Both events involved the activation of the Rb-E2F1 transcriptional regulatory pathway. Stimulation of HAECs with TNF-α led to an increased expression of p73 protein and a reduction in the levels of p53. This involved apoptosis signal-regulating kinase 1 (ASK1)- mediated inactivation of Rb and its dissociation from the p73 promoter. In contrast, TNF-α stimulation of VSMCs enhanced the association of E2F1 with proliferative promoters like thymidylate synthase and cdc25A, while Rb was dissociated. ASK1 kinase has a critical role in the apoptotic process, as its depletion or dissociation from Rb reduced TNF-α-induced apoptosis. These results show that the cytokine TNF-α can elicit diametrically opposite responses in vascular endothelial cells and VSMCs, utilizing the Rb-E2F pathway.
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38
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Gräff J, Kim D, Dobbin MM, Tsai LH. Epigenetic regulation of gene expression in physiological and pathological brain processes. Physiol Rev 2011; 91:603-49. [PMID: 21527733 DOI: 10.1152/physrev.00012.2010] [Citation(s) in RCA: 245] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Over the past decade, it has become increasingly obvious that epigenetic mechanisms are an integral part of a multitude of brain functions that range from the development of the nervous system over basic neuronal functions to higher order cognitive processes. At the same time, a substantial body of evidence has surfaced indicating that several neurodevelopmental, neurodegenerative, and neuropsychiatric disorders are in part caused by aberrant epigenetic modifications. Because of their inherent plasticity, such pathological epigenetic modifications are readily amenable to pharmacological interventions and have thus raised justified hopes that the epigenetic machinery provides a powerful new platform for therapeutic approaches against these diseases. In this review, we give a detailed overview of the implication of epigenetic mechanisms in both physiological and pathological brain processes and summarize the state-of-the-art of "epigenetic medicine" where applicable. Despite, or because of, these new and exciting findings, it is becoming apparent that the epigenetic machinery in the brain is highly complex and intertwined, which underscores the need for more refined studies to disentangle brain-region and cell-type specific epigenetic codes in a given environmental condition. Clearly, the brain contains an epigenetic "hotspot" with a unique potential to not only better understand its most complex functions, but also to treat its most vicious diseases.
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Affiliation(s)
- Johannes Gräff
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, USA
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Grabarczyk P, Nähse V, Delin M, Przybylski G, Depke M, Hildebrandt P, Völker U, Schmidt CA. Increased expression of bcl11b leads to chemoresistance accompanied by G1 accumulation. PLoS One 2010; 5. [PMID: 20824091 PMCID: PMC2932720 DOI: 10.1371/journal.pone.0012532] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 07/22/2010] [Indexed: 12/11/2022] Open
Abstract
Background The expression of BCL11B was reported in T-cells, neurons and keratinocytes. Aberrations of BCL11B locus leading to abnormal gene transcription were identified in human hematological disorders and corresponding animal models. Recently, the elevated levels of Bcl11b protein have been described in a subset of squameous cell carcinoma cases. Despite the rapidly accumulating knowledge concerning Bcl11b biology, the contribution of this protein to normal or transformed cell homeostasis remains open. Methodology/Principal Findings Here, by employing an overexpression strategy we revealed formerly unidentified features of Bcl11b. Two different T-cell lines were forced to express BCL11B at levels similar to those observed in primary T-cell leukemias. This resulted in markedly increased resistance to radiomimetic drugs while no influence on death-receptor apoptotic pathway was observed. Apoptosis resistance triggered by BCL11B overexpression was accompanied by a cell cycle delay caused by accumulation of cells at G1. This cell cycle restriction was associated with upregulation of CDKN1C (p57) and CDKN2C (p18) cyclin dependent kinase inhibitors. Moreover, p27 and p130 proteins accumulated and the SKP2 gene encoding a protein of the ubiquitin-binding complex responsible for their degradation was repressed. Furthermore, the expression of the MYCN oncogene was silenced which resulted in significant depletion of the protein in cells expressing high BCL11B levels. Both cell cycle restriction and resistance to DNA-damage-induced apoptosis coincided and required the histone deacetylase binding N-terminal domain of Bcl11b. The sensitivity to genotoxic stress could be restored by the histone deacetylase inhibitor trichostatine A. Conclusions The data presented here suggest a potential role of BCL11B in tumor survival and encourage developing Bcl11b-inhibitory approaches as a potential tool to specifically target chemoresistant tumor cells.
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Affiliation(s)
- Piotr Grabarczyk
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
| | - Viola Nähse
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
| | - Martin Delin
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
| | - Grzegorz Przybylski
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
| | - Maren Depke
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Petra Hildebrandt
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Uwe Völker
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Christian A. Schmidt
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
- * E-mail:
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Abstract
Developmental and pathological death of neurons requires activation of a defined pathway of cell cycle proteins. However, it is unclear how this pathway is regulated and whether it is relevant in vivo. A screen for transcripts robustly induced in cultured neurons by DNA damage identified Sertad1, a Cdk4 (cyclin-dependent kinase 4) activator. Sertad1 is also induced in neurons by nerve growth factor (NGF) deprivation and Abeta (beta-amyloid). RNA interference-mediated downregulation of Sertad1 protects neurons in all three death models. Studies of NGF withdrawal indicate that Sertad1 is required to initiate the apoptotic cell cycle pathway since its knockdown blocks subsequent pathway events. Finally, we find that Sertad1 expression is required for developmental neuronal death in the cerebral cortex. Sertad1 thus appears to be essential for neuron death in trophic support deprivation in vitro and in vivo and in models of DNA damage and Alzheimer's disease. It may therefore be a suitable target for therapeutic intervention.
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Swiss VA, Casaccia P. Cell-context specific role of the E2F/Rb pathway in development and disease. Glia 2010; 58:377-90. [PMID: 19795505 DOI: 10.1002/glia.20933] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Development of the central nervous system (CNS) requires the generation of neuronal and glial cell subtypes in appropriate numbers, and this demands the careful coordination of cell-cycle exit, survival, and differentiation. The E2F/Rb pathway is critical for cell-cycle regulation and also modulates survival and differentiation of distinct cell types in the developing and adult CNS. In this review, we first present the specific temporal patterns of expression of the E2F and Rb family members during CNS development and then discuss the genetic ablation of single or multiple members of these two families. Overall, the available data suggest a time-dependent and cell-context specific role of E2F and Rb family members in the developing and adult CNS.
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Affiliation(s)
- Victoria A Swiss
- Department of Neuroscience and Genetics and Genomics, Mount Sinai School of Medicine, New York, New York 10029, USA
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42
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Simpson DS, Mason-Richie NA, Gettler CA, Wikenheiser-Brokamp KA. Retinoblastoma family proteins have distinct functions in pulmonary epithelial cells in vivo critical for suppressing cell growth and tumorigenesis. Cancer Res 2009; 69:8733-41. [PMID: 19887614 DOI: 10.1158/0008-5472.can-09-1359] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lung cancer is the leading cause of cancer deaths, accounting for more deaths than breast, colon, and prostate cancer combined. The retinoblastoma (Rb)/p16 tumor suppressive pathway is deregulated in most cancers. Loss of p16 occurs more frequently than Rb loss, suggesting that p16 suppresses cancer by regulating Rb as well as the related proteins p107 and p130. However, direct evidence demonstrating that p130 or p107 cooperate with Rb to suppress epithelial cancers associated with p16 loss is currently lacking. Moreover, the roles of p130 and p107 in lung cancer are not clear. In the present studies, Rb ablation was targeted to the lung epithelium in wild-type, p107, or p130 null mice to determine unique and overlapping Rb family functions critical in tumor suppression. Rb ablation during development resulted in marked epithelial abnormalities despite p107 upregulation. In contrast, p130 and p107 were not required during development but had distinct functions in the Rb-deficient epithelium: p107 was required to suppress proliferation, whereas a novel proapoptotic function was identified for p130. Adult Rb-ablated lungs lacked the epithelial phenotype seen at birth and showed compensatory p107 upregulation and p16 induction in epithelial cell lineages that share phenotypic characteristics with human non-small cell lung cancers (NSCLC) that frequently show p16 loss. Importantly, Rb/p107-deficient, but not Rb/p130-deficient, lungs developed tumors resembling NSCLC. Taken together, these studies identify distinct Rb family functions critical in controlling epithelial cell growth, and provide direct evidence that p107 cooperates with Rb to protect against a common adult cancer.
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Affiliation(s)
- David S Simpson
- Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio 45229-3039, USA
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43
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Li G, Li W, Angelastro JM, Greene LA, Liu DX. Identification of a novel DNA binding site and a transcriptional target for activating transcription factor 5 in c6 glioma and mcf-7 breast cancer cells. Mol Cancer Res 2009; 7:933-43. [PMID: 19531563 DOI: 10.1158/1541-7786.mcr-08-0365] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent reports indicate that the activating transcription factor 5 (ATF5) is required for the survival of cancer cells but not for noncancer cells. However, the mechanisms by which ATF5 regulates genes and promotes cell survival are not clear. Using a cyclic amplification and selection of targets (CASTing) approach, we identified a novel ATF5 consensus DNA binding sequence. We show in C6 glioma and MCF-7 breast cancer cells that ATF5 occupies this sequence and that ATF5 activates reporter gene expression driven by this site. Conversely, reporter activity is diminished when ATF5 activity is blocked or when ATF5 expression is down-regulated by serum withdrawal. We further show that early growth response factor 1 (Egr-1), whose promoter contains two adjacent ATF5 consensus binding sites at a conserved promoter position in rat, mouse, and human, is targeted and regulated by ATF5 in C6 and MCF-7 cells. These data provide new insight on the mechanisms by which ATF5 promotes gene regulation and cancer-specific cell survival.
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Affiliation(s)
- Guangfu Li
- Department of Neural and Behavioral Sciences, Penn State University College of Medicine, Hershey, 17033, USA
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44
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Kim D, Frank CL, Dobbin MM, Tsunemoto RK, Tu W, Peng PL, Guan JS, Lee BH, Moy LY, Giusti P, Broodie N, Mazitschek R, Delalle I, Haggarty SJ, Neve RL, Lu Y, Tsai LH. Deregulation of HDAC1 by p25/Cdk5 in neurotoxicity. Neuron 2009; 60:803-17. [PMID: 19081376 DOI: 10.1016/j.neuron.2008.10.015] [Citation(s) in RCA: 221] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 09/02/2008] [Accepted: 10/09/2008] [Indexed: 12/19/2022]
Abstract
Aberrant cell-cycle activity and DNA damage are emerging as important pathological components in various neurodegenerative conditions. However, their underlying mechanisms are poorly understood. Here, we show that deregulation of histone deacetylase 1 (HDAC1) activity by p25/Cdk5 induces aberrant cell-cycle activity and double-strand DNA breaks leading to neurotoxicity. In a transgenic model for neurodegeneration, p25/Cdk5 activity elicited cell-cycle activity and double-strand DNA breaks that preceded neuronal death. Inhibition of HDAC1 activity by p25/Cdk5 was identified as an underlying mechanism for these events, and HDAC1 gain of function provided potent protection against DNA damage and neurotoxicity in cultured neurons and an in vivo model for ischemia. Our findings outline a pathological signaling pathway illustrating the importance of maintaining HDAC1 activity in the adult neuron. This pathway constitutes a molecular link between aberrant cell-cycle activity and DNA damage and is a potential target for therapeutics against diseases and conditions involving neuronal death.
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Affiliation(s)
- Dohoon Kim
- Howard Hughes Medical Institute, Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Qiu Z, Ghosh A. A calcium-dependent switch in a CREST-BRG1 complex regulates activity-dependent gene expression. Neuron 2009; 60:775-87. [PMID: 19081374 DOI: 10.1016/j.neuron.2008.09.040] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 07/14/2008] [Accepted: 09/29/2008] [Indexed: 01/27/2023]
Abstract
CREST plays a critical role in activity-dependent development, but its mechanism of action is not well understood. Here, we show that a CREST-BRG1 complex regulates promoter activation by orchestrating a calcium-dependent release of a repressor complex and a recruitment of an activator complex. In resting neurons, transcription of the c-fos promoter is inhibited by BRG1-dependent recruitment of a phospho-Rb-HDAC repressor complex. Upon calcium influx, Rb becomes dephosphorylated at serine 795 by calcineurin, which leads to release of the repressor complex. At the same time, there is increased recruitment of CBP to the promoter by a CREST-dependent mechanism, which leads to transcriptional activation. The CREST-BRG1 also binds to the NR2B promoter, and activity-dependent induction of NR2B expression involves a release of HDAC1 and recruitment of CBP, suggesting that this mechanism may be generally involved in regulating calcium-dependent transcription of neuronal genes.
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Affiliation(s)
- Zilong Qiu
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0366, USA
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46
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Wu H, Zhu H, Liu DX, Niu TK, Ren X, Patel R, Hait WN, Yang JM. Silencing of elongation factor-2 kinase potentiates the effect of 2-deoxy-D-glucose against human glioma cells through blunting of autophagy. Cancer Res 2009; 69:2453-60. [PMID: 19244119 DOI: 10.1158/0008-5472.can-08-2872] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
2-Deoxy-d-glucose (2-DG), a synthetic glucose analogue that acts as a glycolytic inhibitor, is currently being evaluated in the clinic as an anticancer agent. In this study, we observed that treatment of human glioma cells with 2-DG activated autophagy, a highly conserved cellular response to metabolic stress and a catabolic process of self-digestion of intracellular organelles for energy use and survival in stressed cells. The induction of autophagy by 2-DG was associated with activation of elongation factor-2 kinase (eEF-2 kinase), a structurally and functionally unique enzyme that phosphorylates eEF-2, leading to loss of affinity of this elongation factor for the ribosome and to termination of protein elongation. We also showed that inhibition of eEF-2 kinase by RNA interference blunted the 2-DG-induced autophagic response, resulted in a greater reduction of cellular ATP contents, and increased the sensitivity of tumor cells to the cytotoxic effect of 2-DG. Furthermore, the blunted autophagy and enhanced 2-DG cytotoxicity were accompanied by augmentation of apoptosis in cells in which eEF-2 kinase expression was knocked down. The results of this study indicate that the energy stress and cytotoxicity caused by 2-DG can be accelerated by inhibition of eEF-2 kinase, and suggest that targeting eEF-2 kinase-regulated autophagic survival pathway may represent a novel approach to sensitizing cancer cells to glycolytic inhibitors.
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Affiliation(s)
- Hao Wu
- Department of Pharmacology, Neural and Behavioral Sciences, and The Penn State Cancer Institute, Pennsylvania State University College of Medicine and Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA
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47
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The chemokine CXCL12 promotes survival of postmitotic neurons by regulating Rb protein. Cell Death Differ 2008; 15:1663-72. [PMID: 18583990 DOI: 10.1038/cdd.2008.95] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Postmitotic neurons need to keep their cell cycle under control to survive and maintain a differentiated state. This study aims to test the hypothesis that the chemokine CXCL12 regulates neuronal survival and differentiation by promoting Rb function, as suggested by previous studies showing that CXCL12 protects neurons from apoptosis induced by Rb loss. To this end, the effect of CXCL12 on Rb expression and transcriptional activity and the role of Rb in CXCL12-induced neuronal survival were studied. CXCL12 increases Rb protein and RNA levels in rat cortical neurons. The chemokine also stimulates an exogenous Rb promoter expressed in these neurons and counteracts the inhibition of the Rb promoter induced by E2F1 overexpression. Furthermore CXCL12 stimulates Rb activity as a transcription repressor. The effects of CXCL12 are mediated by its specific receptor CXCR4, and do not require the presence of glia. Finally, shRNA studies show that Rb expression is crucial to the neuroprotective activity of CXCL12 as indicated by NMDA-neurotoxicity assays. These findings suggest that proper CXCR4 stimulation in the mature CNS can prevent impairment of the Rb-E2F pathway and support neuronal survival. This is important to maintain CNS integrity in physiological conditions and prevent neuronal injury and loss typical of many neurodegenerative and neuroinflammatory conditions.
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48
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A comprehensive modular map of molecular interactions in RB/E2F pathway. Mol Syst Biol 2008; 4:173. [PMID: 18319725 PMCID: PMC2290939 DOI: 10.1038/msb.2008.7] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 01/23/2008] [Indexed: 12/16/2022] Open
Abstract
We present, here, a detailed and curated map of molecular interactions taking place in the regulation of the cell cycle by the retinoblastoma protein (RB/RB1). Deregulations and/or mutations in this pathway are observed in most human cancers. The map was created using Systems Biology Graphical Notation language with the help of CellDesigner 3.5 software and converted into BioPAX 2.0 pathway description format. In the current state the map contains 78 proteins, 176 genes, 99 protein complexes, 208 distinct chemical species and 165 chemical reactions. Overall, the map recapitulates biological facts from approximately 350 publications annotated in the diagram. The network contains more details about RB/E2F interaction network than existing large-scale pathway databases. Structural analysis of the interaction network revealed a modular organization of the network, which was used to elaborate a more summarized, higher-level representation of RB/E2F network. The simplification of complex networks opens the road for creating realistic computational models of this regulatory pathway.
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49
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Wright KM, Smith MI, Farrag L, Deshmukh M. Chromatin modification of Apaf-1 restricts the apoptotic pathway in mature neurons. ACTA ACUST UNITED AC 2007; 179:825-32. [PMID: 18056406 PMCID: PMC2099178 DOI: 10.1083/jcb.200708086] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Although apoptosis has been extensively studied in developing neurons, the dynamic changes in this pathway after neuronal maturation remain largely unexplored. We show that as neurons mature, cytochrome c– mediated apoptosis progresses from inhibitor of apoptosis protein–dependent to –independent regulation because of a complete loss of Apaf-1 expression. However, after DNA damage, mature neurons resynthesize Apaf-1 through the cell cycle–related E2F1 pathway and restore their apoptotic potential. Surprisingly, we find that E2F1 is sufficient to induce Apaf-1 expression in developing but not mature neurons. Rather, Apaf-1 up-regulation in mature neurons requires both chromatin derepression and E2F1 transcriptional activity. This differential capacity of E2F1 to induce Apaf-1 transcription is because of the association of the Apaf-1 promoter with active chromatin in developing neurons and repressed chromatin in mature neurons. These data specifically illustrate how the apoptotic pathway in mature neurons becomes increasingly restricted by a novel mechanism involving the regulation of chromatin structure.
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Affiliation(s)
- Kevin M Wright
- Neuroscience Center and 2Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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50
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Panteleeva I, Boutillier S, See V, Spiller DG, Rouaux C, Almouzni G, Bailly D, Maison C, Lai HC, Loeffler JP, Boutillier AL. HP1alpha guides neuronal fate by timing E2F-targeted genes silencing during terminal differentiation. EMBO J 2007; 26:3616-28. [PMID: 17627279 PMCID: PMC1949014 DOI: 10.1038/sj.emboj.7601789] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 06/11/2007] [Indexed: 11/09/2022] Open
Abstract
A critical step of neuronal terminal differentiation is the permanent withdrawal from the cell cycle that requires the silencing of genes that drive mitosis. Here, we describe that the alpha isoform of the heterochromatin protein 1 (HP1) protein family exerts such silencing on several E2F-targeted genes. Among the different isoforms, HP1alpha levels progressively increase throughout differentiation and take over HP1gamma binding on E2F sites in mature neurons. When overexpressed, only HP1alpha is able to ensure a timed repression of E2F genes. Specific inhibition of HP1alpha expression drives neuronal progenitors either towards death or cell cycle progression, yet preventing the expression of the neuronal marker microtubule-associated protein 2. Furthermore, we provide evidence that this mechanism occurs in cerebellar granule neurons in vivo, during the postnatal development of the cerebellum. Finally, our results suggest that E2F-targeted genes are packaged into higher-order chromatin structures in mature neurons relative to neuroblasts, likely reflecting a transition from a 'repressed' versus 'silenced' status of these genes. Together, these data present new epigenetic regulations orchestrated by HP1 isoforms, critical for permanent cell cycle exit during neuronal differentiation.
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Affiliation(s)
- Irina Panteleeva
- INSERM, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, France
- Université Louis Pasteur, Faculté de médecine, UMRS692, Strasbourg, France
| | - Stéphanie Boutillier
- INSERM, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, France
- Université Louis Pasteur, Faculté de médecine, UMRS692, Strasbourg, France
| | - Violaine See
- Centre for Cell Imaging, University of Liverpool, Liverpool L69 7ZB, UK
| | - Dave G Spiller
- Centre for Cell Imaging, University of Liverpool, Liverpool L69 7ZB, UK
| | - Caroline Rouaux
- INSERM, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, France
- Université Louis Pasteur, Faculté de médecine, UMRS692, Strasbourg, France
| | | | | | | | - Helen C Lai
- Department of Neuroscience, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Jean-Philippe Loeffler
- INSERM, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, France
- Université Louis Pasteur, Faculté de médecine, UMRS692, Strasbourg, France
- INSERM, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Faculté de médecine, 11 rue Humann, Strasbourg 67085, France. Tel.: +33 390 24 30 82; Fax: +33 390 24 30 65; E-mail:
| | - Anne-Laurence Boutillier
- INSERM, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, France
- Université Louis Pasteur, Faculté de médecine, UMRS692, Strasbourg, France
- INSERM, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Faculté de médecine, 11 rue Humann, Strasbourg 67085, France. Tel.: +33 390 24 30 82; Fax: +33 390 24 30 65; E-mail:
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